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1

Sampling problems  

NASA Technical Reports Server (NTRS)

Precipitation estimates from satellites are subject to a number of uncertainties involving design characteristics, satellite positioning, natural variability of precipitation, and the noncontinuous acquisition of data. The sources and sizes of these uncertainties are in need of proper evaluation and estimation. The present sampling and estima-theory seems to be adequate for some measurement problems (e.g., determining precipitation at a point), while others require further theoretical work (e.g., determining the time history of precipitation over large areas).

Flueck, J. A.; Crane, R. F.; Laughlin, C. R.; Bell, T. L.; Meiten, J. G.; Ruprecht, E.; Short, D. R.; Theon, J. S.; Vogel, J. L.

1981-01-01

2

Multiple Solutions Involving Geoboard Problems.  

ERIC Educational Resources Information Center

Illustrates various methods to determine the perimeter and area of triangles and polygons formed on the geoboard. Methods utilize algebraic techniques, trigonometry, geometric theorems, and analytic geometry to solve problems and connect a variety of mathematical concepts. (MDH)

Smith, Lyle R.

1993-01-01

3

Algorithms for Routing Problems Involving UAVs  

Microsoft Academic Search

Routing problems naturally arise in several civil and military applications involving Unmanned Aerial Vehicles (UAVs) with\\u000a fuel and motion constraints. A typical routing problem requires a team of UAVs to visit a collection of targets with an objective\\u000a of minimizing the total distance travelled. In this chapter, we consider a class of routing problems and review the classical\\u000a results and

Sivakumar Rathinam; Raja Sengupta

2007-01-01

4

Boundary Crossing Problems for Sample Means  

Microsoft Academic Search

Motivated by several classical sequential decision problems, we study herein the following type of boundary crossing problems for certain nonlinear functions of sample means. Let $X_1, X_2,\\\\ldots$ be i.i.d. random vectors whose common density belongs to the $k$-dimensional exponential family $h_\\\\theta(x) = \\\\exp\\\\{\\\\theta'x - \\\\psi(\\\\theta)\\\\}$ with respect to some nondegenerate measure $\\\

Tze Leung Lai

1988-01-01

5

Regularization of Inverse Visual Problems Involving Discontinuities  

Microsoft Academic Search

Inverse problems, such as the reconstruction problems that arise in early vision, tend to be mathematically ill-posed. Through regularization, they may be reformulated as well-posed variational principles whose solutions are computable. Standard regularization theory employs quadratic stabilizing functionals that impose global smoothness constraints on possible solutions. Discontinuities present serious difficulties to standard regularization, however, since their reconstruction requires a precise

Demetri Terzopoulos

1986-01-01

6

Problems pilots face involving wind shear  

NASA Technical Reports Server (NTRS)

Educating pilots and the aviation industry about wind shears presents a major problem associated with this meteorological phenomenon. The pilot's second most pressing problem is the need for a language to discuss wind shear encounters with other pilots so that the reaction of the aircraft to the wind shear encounter can be accurately described. Another problem is the flight director which gives a centered pitch command for a given angular displacement from the glide slope. It was suggested that they should instead be called flight path command and should not center unless the aircraft is actually correcting to the flight path.

Melvin, W. W.

1977-01-01

7

A Two-Step Sample Size Problem.  

National Technical Information Service (NTIS)

A problem in sampling is given in which an estimator of the mean of a normal population is determined such that the estimator deviates from the true population parameter by less than a given percentage of the true parameter with at least a certain specifi...

R. C. Rounding

1965-01-01

8

iTOUGH2 Sample Problems  

SciTech Connect

iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media. This report contains a collection of iTOUGH2 sample problems.

Finsterle, Stefan

2002-06-18

9

Processes Involved in Mathematical Problem Solving  

ERIC Educational Resources Information Center

This clinical, exploratory study describes processes used by 8 ninth-graders learning to solve non-routine geometry problems and changes in those processes as instruction in heuristic methods was given. Directions for future research are indicated, and several hypotheses to be investigated are suggested. (DT)

Kantowski, Mary Grace

1977-01-01

10

A Facility Layout Problem Involving Lattice Points.  

National Technical Information Service (NTIS)

The problem considered in this paper is to find a layout of a given number of identical facilities so that the total (or average) rectilinear distance between facilities is minimized. The potential locations for the facilities are lattice points in the pl...

A. W. Chan R. L. Francis

1974-01-01

11

Physics Suite Sample Problems: Properties of Matter  

NSDL National Science Digital Library

This page contains a series of problems on properties of matter, developed for use with The Physics Suite, an activity-based learning project. Each problem was designed to help build qualitative understanding of physics and was built around student acquisition of knowledge as observed in recent studies. The problems vary in format and include estimation, context-based reasoning, multiple choice, short answer, qualitative questions, and essay questions. The topics include pressure, density, buoyancy, ideal gas law, and fluid flow rates. This item is part of a larger collection of problems, in-class questions, and interactive resources developed by the University of Maryland Physics Education Research Group.

Redish, Edward F.

2008-07-20

12

Physics Suite Sample Problems: Modern Physics  

NSDL National Science Digital Library

This is a collection of introductory physics problems on topics in 20th century physics. The questions are designed for active learning classrooms and are built around research on student acquisition of knowledge. The problems vary in format and include context-based reasoning, multiple choice, estimation, and essay questions. The topics include conservation of mass and energy, nuclear decay, wave-particle duality, and spectroscopy. This item is part of a larger collection of problems, in-class questions, and interactive resources developed by the University of Maryland Physics Education Research Group.

Redish, Edward F.

2005-08-09

13

Suicidal ideation among adolescent school children, involvement in bully-victim problems, and perceived social support.  

PubMed

Relationships among suicidal ideation, involvement in bully-victim problems at school, and perceived social support were investigated with samples of adolescent students (N = 1103 and N = 845) attending secondary school in South Australia. Results obtained from self-reports and peer nomination procedures to identify bullies and victims indicated that involvement in bully-victim problems at school, especially for students with relatively little social support, was significantly related to degree of suicidal ideation. PMID:10407965

Rigby, K; Slee, P

1999-01-01

14

An importance sampling method with applications to vehicle routing problem  

Microsoft Academic Search

Vehicle routing problem belongs to classical Combination Optimization hard problem and has been extensively studied by many researchers. The main purpose of this paper is to establish the model which named Vehicle Routing Problem with Weight Coefficients and Stochastic Demands (WVRPSD) and propose an effective algorithm based on Important Sampling to solve this model. The optimal importance sampling distribution function

Yue Qiu

2010-01-01

15

Power and Sample Size Calculations for Studies Involving Linear Regression  

Microsoft Academic Search

This article presents methods for sample size and power calculations for studies involving linear regression. These approaches are applicable to clinical trials designed to detect a regression slope of a given magnitude or to studies that test whether the slopes or intercepts of two independent regression lines differ by a given amount. The investigator may either specify the values of

William D. Dupont; Walton D. Plummer

1998-01-01

16

A NUMERICAL MODEL FOR GEOTECHNICAL PROBLEMS INVOLVING PARTIALLY SATURATED SOILS  

Microsoft Academic Search

\\u000a The paper deals with a numeric model for coupled solid–fluid FE analyses of geotechnical problems involving partially saturated\\u000a soils. The Barcelona Basic Model serves as a constitutive model for the soil skeleton. Different stress update algorithms\\u000a are compared for this model regarding robustness, accuracy, and efficiency. The application of the numerical model is demonstrated\\u000a by numerical simulations of the impoundment

G. Hofstetter; M. Pertl; M. Hofmann

17

Solving the Small Sample Size Problem of LDA  

Microsoft Academic Search

The small sample size problem is often encountered in pattern recognition. It results in the singularity of the within-class scatter matrix Sw in Linear Discriminant Analysis (LDA). Different methods have been proposed to solve this problem in face recognition literature. Some methods reduce the dimension of the original sample space and hence unavoidably remove the null space of Sw, which

Rui Huang; Qingshan Liu; Hanqing Lu; Songde Ma

2002-01-01

18

Breadth and depth involvement: Understanding Internet gambling involvement and its relationship to gambling problems.  

PubMed

[Correction Notice: An Erratum for this article was reported in Vol 28(2) of Psychology of Addictive Behaviors (see record 2014-12580-001). The article incorrectly stated under the Procedures heading on page 3 that "The Cambridge Health Alliance Institutional Review Board approved our application to conduct the Web-based BBGS survey and secondary data analyses of the bwin.party subscriber database." The authors alerted the journal that this project would have been exempt from IRB review and under this circumstance the IRB would not have issued any formal approval. Consequently, the published statement is inaccurate.] The "involvement effect" refers to the finding that controlling for gambling involvement often reduces or eliminates frequently observed game-specific associations with problem gambling. In other words, broader patterns of gambling behavior, particularly the number of types of games played over a defined period, contribute more to problem gambling than playing specific games (e.g., lottery, casino, Internet gambling). This study extends this burgeoning area of inquiry in three primary ways. First, it tests independently and simultaneously the predictive power of two gambling patterns: breadth involvement (i.e., the number of games an individual plays) and depth involvement (i.e., the number of days an individual plays). Second, it includes the first involvement analyses of actual betting activity records that are associated with clinical screening information. Third, it evaluates and compares the linearity of breadth and depth effects. We conducted analyses of the actual gambling activity of 1,440 subscribers to the bwin.party gambling service who completed an online gambling disorder screen. In all, 11 of the 16 games we examined had a significant univariate association with a positive screen for gambling disorder. However, after controlling for breadth involvement, only Live Action Internet sports betting retained a significant relationship with potential gambling-related problems. Depth involvement, though significantly related to potential problems, did not impact game-based gambling disorder associations as much as breadth involvement. Finally, breadth effects appeared steeply linear, with a slight quadratic component manifesting beyond four games played, but depth effects appeared to have a strong linear component and a slight cubic component. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:23915365

LaPlante, Debi A; Nelson, Sarah E; Gray, Heather M

2014-06-01

19

Longitudinal Modeling of Adolescents' Activity Involvement, Problem Peer Associations, and Youth Smoking  

ERIC Educational Resources Information Center

Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24 months) enriched for smoking experimentation (83% had tried smoking). A structural equation model…

Metzger, Aaron; Dawes, Nickki; Mermelstein, Robin; Wakschlag, Lauren

2011-01-01

20

The New Workforce Generation: Understanding the Problems Facing Parental Involvement in Jordanian Kindergartens  

ERIC Educational Resources Information Center

This study aimed to investigate the problems facing parental involvement in Jordanian kindergartens from the parents' perspectives. A 36-item questionnaire that addressed five domains was designed by the researchers and distributed among the study participants. The study sample consisted of 297 parents of kindergarten children from various…

Ihmeideh, Fathi; Khasawneh, Samer; Mahfouz, Safi; Khawaldeh, Moustafa

2008-01-01

21

Longitudinal modeling of adolescents' activity involvement, problem peer associations, and youth smoking  

Microsoft Academic Search

Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24months) enriched for smoking experimentation (83% had tried smoking). A structural equation model tested longitudinal paths between three categories of involvement (team sports, school clubs

Aaron Metzger; Nickki Dawes; Robin Mermelstein; Lauren Wakschlag

2011-01-01

22

Ethnicity and bullying involvement in a national UK youth sample.  

PubMed

This study investigated ethnic differences in bullying involvement (as victim and bully) among a UK wide sample of adolescents, controlling for potential confounders, including age, gender, economic situation, family structure and parent-adolescent relationships. 4668 youths, aged 10 to 15, who participate in the UK Household Longitudinal Study were assessed for bullying involvement. Binary logistic regression models were used to estimate ethnic differences across bullying roles while controlling for potential confounders. Overall, ethnic minority youths were not more likely to be victims; African boys and girls were significantly less likely to be victimised than same sex White youths. Pakistani and Caribbean girls were significantly more likely to have bullied others compared to White girls. Further research is necessary to explore why Pakistani and Caribbean girls may be more often perpetrators of bullying than girls in other ethnic groups. PMID:23849658

Tippett, Neil; Wolke, Dieter; Platt, Lucinda

2013-08-01

23

Sampling problems in the micro determination of blood lead.  

PubMed

Sampling tube and fingertip contamination were found to present potential problems in the collection of samples for micro blood lead analyses. Large differences between micro screening and macro confirming lead levels were frequently observed when the time between collection of the two samples was 1-2 weeks. The magnitude of these differences decreased as macro blood lead concentration increased and were apparently a result of episodic lead ingestion in the population. PMID:1137934

Juselius, R E; Lupovich, P; Moriarty, R

1975-01-01

24

Multiscale treatment of mechanical contact problems involving thin polymeric layers  

NASA Astrophysics Data System (ADS)

We propose a strategy to obtain a hyperelastic constitutive law for film-like systems from molecular dynamics (MD) simulations. The aim is to furnish a computationally efficient continuum model with this description of the material. In particular, two different methods are suggested, both of which consist of virtual experiments that are performed on the material to sample systematically the stress–strain relation. The latter is then fitted to a suitable functional form. We use a polymeric self-assembled monolayer, which spans a height of only a few nanometers, as a test case. Having determined the response function, we then apply it within a finite-element simulation of a continuum mechanical nanoindentation problem. Several contact quantities such as normal reaction forces and the contact geometry are extracted from these calculations and are compared to those from an analogous, fully atomistic nanoindentation simulation. We find that the considered benchmark quantities as obtained from the continuum surrogate model reproduce well the corresponding values of the MD simulation.

Schmidt, Marcus G.; Sauer, Roger A.; Ismail, Ahmed E.

2014-06-01

25

Parallel Tempering for sampling and optimization in seismic inverse problems  

NASA Astrophysics Data System (ADS)

The field of seismology is rich with inverse problems. Seismologists are constantly seeking new ways to use seismic waveforms, and data products derived from them, to constrain subsurface structure in the form of Earth properties in 1-, 2- and 3 dimensions, as well as seismic sources in space and time. Every approach has its limitations and a virtual smorgasbord of methods exist, and have been applied over thirty years, with varying degrees of success. In this presentation we discuss a new class of approach. Parallel Tempering (PT) is a technique originating in the field of computational statistics that is finding increasing success for probabilistic sampling problems in astro and quantum physics, and more recently ocean acoustics but appears to be virtually unknown in the solid earth geosciences. In seismology two classes of inference approach are common for nonlinear inverse problems, Bayesian (probabilistic) sampling and optimization. Parallel Tempering can be applied to both situations and is related to better known methods such as Simulated Annealing and Metropolis Sampling. PT is distinguished as it has a theoretical basis for being superior to both. PT is best viewed as a `meta' algorithm. In a sense wrapping around existing optimization or Bayesian sampling methods to facilitate more robust performance (optimization) and more rapid exploration of parameter space (sampling). PT has generated much interest across the physical sciences with encouraging results emerging. This presentation will describe the basic ideas, and present results of implementations on seismic waveform inversion for both sampling and optimization.

Sambridge, Malcolm

2013-04-01

26

Collecting Language Samples from Children with Syntax Problems.  

ERIC Educational Resources Information Center

The article suggests that comparability, representativeness, and typicality must be considered along with length when collecting language samples. A framework is offered for selecting or devising tasks, and one successful battery is described which has been field tested on language-disordered children with syntax problems. (CL)

Wren, Carol T.

1985-01-01

27

Crack problems involving nonhomogeneous interfacial regions in bonded materials  

NASA Technical Reports Server (NTRS)

Consideration is given to two classes of fracture-related solid mechanics problems in which the model leads to some physically anomalous results. The first is the interface crack problem associated with the debonding process in which the corresponding elasticity solution predicts severe oscillations of stresses and the crack surface displacements vary near the crack tip. The second deals with crack intersecting the interface. The nature of the solutions around the crack tips arising from these problems is reviewed. The rationale for introducing a new interfacial zone model is discussed, its analytical consequences within the context of the two crack-problem classes are described, and some examples are presented.

Erdogan, F.

1990-01-01

28

Henyey method revisited - an application to problems involving critical points  

NASA Astrophysics Data System (ADS)

A quite general numerical technique, based on Henyey method, is developed for solving boundary value problems. Having in mind astrophysical applications connected with hydrodynamics, the code is explicitly designed to treat also systems of ordinary differential equations which exhibit one, or more, critical point. Some illustrative test runs, mainly concerning problems of astrophysical interest, are presented and discussed.

Nobili, Luciano; Turolla, Roberto

1988-10-01

29

Enhanced multilevel linear sampling methods for inverse scattering problems  

NASA Astrophysics Data System (ADS)

We develop two enhanced techniques for the multilevel linear sampling method (MLSM) proposed in [32] for inverse scattering problems. Under some practical situations, the MLSM suffers certain undesirable "breakage cells" problem. We propose to avoid the curse of "breakage cells" by incorporating "expanding" and "searching" techniques. The new techniques are shown to significantly improve the robustness of the MLSM, and meanwhile they possess the same optimal computational complexity as the MLSM. Numerical experiments are presented to illustrate the promising features of the enhanced MLSMs.

Li, Jingzhi; Liu, Hongyu; Wang, Qi

2014-01-01

30

The two-sample problem with induced dependent censorship.  

PubMed

Induced dependent censorship is a general phenomenon in health service evaluation studies in which a measure such as quality-adjusted survival time or lifetime medical cost is of interest. We investigate the two-sample problem and propose two classes of nonparametric tests. Based on consistent estimation of the survival function for each sample, the two classes of test statistics examine the cumulative weighted difference in hazard functions and in survival functions. We derive a unified asymptotic null distribution theory and inference procedure. The tests are applied to trial V of the International Breast Cancer Study Group and show that long duration chemotherapy significantly improves time without symptoms of disease and toxicity of treatment as compared with the short duration treatment. Simulation studies demonstrate that the proposed tests, with a wide range of weight choices, perform well under moderate sample sizes. PMID:11315055

Huang, Y

1999-12-01

31

Some New Twists to Problems Involving the Gaussian Probability Integral  

NASA Technical Reports Server (NTRS)

Using an alternate form of the Gaussian probability integral discovered a number of years ago, it is shown that the solution to a number of previously considered communication problems can be simplified and in some cases made more accurate(i.e., exact rather than bounded).

Simon, Marvin K.; Divsalar, Dariush

1997-01-01

32

A resolution of the ascertainment sampling problem. III. Pedigrees.  

PubMed Central

When nuclear families are sampled by an ascertainment procedure whose properties are not known, biased estimates of genetic parameters will arise if an incorrect specification of the ascertainment procedure is made. Elsewhere we have put forward a resolution of this problem by introducing an ascertainment-assumption-free (AAF) method, for nuclear family data, which gives asymptotically unbiased estimators no matter what the true nature of the ascertainment process. In the present paper we extend this method to cover pedigree data. Problems that arise with pedigrees but not with families--for example, the question of which families in a pedigree are "ascertainable"--are also considered. Comparisons of numerical results for pedigrees and nuclear families are also made.

Shute, N C; Ewens, W J

1988-01-01

33

Elliptic problems involving the fractional Laplacian in RN  

NASA Astrophysics Data System (ADS)

We study the existence and multiplicity of solutions for elliptic equations in RN, driven by a non-local integro-differential operator, which main prototype is the fractional Laplacian. The model under consideration, denoted by (P?), depends on a real parameter ? and involves two superlinear nonlinearities, one of which could be critical or even supercritical. The main theorem of the paper establishes the existence of three critical values of ? which divide the real line in different intervals, where (P?) admits no solutions, at least one nontrivial non-negative entire solution and two nontrivial non-negative entire solutions.

Autuori, Giuseppina; Pucci, Patrizia

34

Defining the Mars Ascent Problem for Sample Return  

SciTech Connect

Lifting geology samples off of Mars is both a daunting technical problem for propulsion experts and a cultural challenge for the entire community that plans and implements planetary science missions. The vast majority of science spacecraft require propulsive maneuvers that are similar to what is done routinely with communication satellites, so most needs have been met by adapting hardware and methods from the satellite industry. While it is even possible to reach Earth from the surface of the moon using such traditional technology, ascending from the surface of Mars is beyond proven capability for either solid or liquid propellant rocket technology. Miniature rocket stages for a Mars ascent vehicle would need to be over 80 percent propellant by mass. It is argued that the planetary community faces a steep learning curve toward nontraditional propulsion expertise, in order to successfully accomplish a Mars sample return mission. A cultural shift may be needed to accommodate more technical risk acceptance during the technology development phase.

Whitehead, J

2008-07-31

35

On a shock problem involving a linear viscoelastic bar  

Microsoft Academic Search

The paper deals with the initial-boundary value problem for the linear wave equation(1)utt-?(t)uxx+Ku+?ut=f(x,t),0x1,0tT,u(0,t)=0,-?(t)ux(1,t)=Q(t),u(x,0)=u0(x),ut(x,0)=u1(x),where K, ? are given constants and u0, u1, f, ? are given functions, the unknown function u(x,t) and the unknown boundary value Q(t) satisfy the following linear integral equation(2)Q(t)=K1(t)u(1,t)+?1(t)ut(1,t)-g(t)-?0tk(t-s)u(1,s)ds,where g, k, K1, ?1 are given functions. The paper consists of four parts. In Part 1 we prove

Nguyen Thanh Long; Le Van Ut; Nguyen Thi Thao Truc

2005-01-01

36

Two problems involving the notion of phase transition  

NASA Astrophysics Data System (ADS)

The first problem we consider is from statistical physics. Write I=IS for the set of independent sets of the graph S . For S finite and l > 0, the hard-core measure with activity l on I is given by mI=l I/Z ?I?I, where Z = l I:I?I is the appropriate normalizing constant. We say that this measure is hc( l ). For infinite S a measure m on I is hc( l ) if for I chosen from I according to m and for all finite W ? V = V(G), the conditional distribution of I ? W given I ? (VW) is ( m -a.s.) hc( l ) on the independent sets of {w ? W : w ? I ? (VW)}. There is always at least one such measure. If there is more than one, the model is said to have a phase transition. Dobrushin [9] (and later, independently, Louth [21]) showed that there is a phase transition in the hard-core model on (the usual nearest neighbor graph on) Zd for sufficiently large values of l (depending on d). In other words, they showed that ld : =sup thehard-c oremodelwitha ctivitylon l: Zd doesnothave aphasetransition problem we consider comes from discrete probability. It was introduced by Benjamini, Haggstrom and Mossel [2] (and, in a different context, by Athanasiadis [1]). Write F for the set of homomorphisms from the d-dimensional Hamming cube {0,1}d to (the Hamming graph on) Z which send 0&barbelow; (the all-zero string) to 0 and F?5 for those which take on five or fewer values. (A homomorphism between graphs is an adjacency preserving map between vertex sets.) We show that F˜ F?5˜ 2e22d-1 , proving a conjecture of Kahn [15]. This result can be viewed as a "phase transition" statement: with high probability, a randomly chosen f ? F will be either predominantly 0 on the even vertices of the cube (those vertices whose l1 distance from 0&barbelow; is even), with occasional +/-2's, or predominantly 1 (resp. -1) on the odd vertices, with occasional -1's and 3's (resp. -3's and 1's).

Galvin, David James

37

Analysing the problems involved in assessing hydro-meteorological triggers.  

NASA Astrophysics Data System (ADS)

A key component in risk assessments is quantifying the probability of occurrence and the intensity of the hazards, which will alter with climate change. However, before future changes in these hazards can be determined, the current relationship between the hazard and the meteorological trigger should be understood. It is known that intense short duration precipitation, long-lasting rainfall and snow-melt are all important for mountainous areas in Europe, yet determining the precise triggers and their temporal probability faces many challenges. While long records are necessary to capture natural variations in the climate and a number of hazard occurrences, long records are often incomplete and not homogeneous. There is also often a spatial mismatch between climate observations and the meteorological mechanism which is actually triggering a flood or a landslide. Furthermore, meteorological triggers do not act alone - land cover and use, engineering works and changes in the slope conditions can all influence the probability of occurrence. The objective of this work is to explore the current challenges faced when trying to determine the temporal probability of hydro-meteorological triggers as well as potential solutions to the challenges identified. Examples are drawn from floods and landslides observed in the Ubaye Valley (France) and in the Fella River Basin (Italy), focusing on how data availability and quality, conceptualization of the problem and different statistically based approaches all alter the temporal probability of hydro-meteorological triggers. With a better understanding of the underlying uncertainties in meteorological triggering conditions for hydro-meteorological hazards, this will hopefully lead to a better understanding and quantification of hydro-meteorological hazards for risk assessment, for now and future projections. This work is part of the "CHANGES" project, funded by the European Community's 7th Framework Programme.

Turkington, Thea; Breinl, Korbinian; van Westen, Cees J.; Malet, Jean-Philippe; Ettema, Janneke

2013-04-01

38

Problem drinking and the dimension of involvement with drugs: a Guttman scalogram analysis of adolescent drug use.  

PubMed Central

Analyses of data from two nationwide surveys of high school students, one carried out in 1974 and the other in 1978, suggest that problem drinking may be seen as yet another step along an underlying dimension of involvement with both licit and illicit drugs. The dimension of involvement with drugs consists of the following levels: nonuse of alcohol or illicit drugs; nonproblem use of alcohol; marijuana use; problem drinking; use of pills (amphetamines, barbiturates, hallucinogenic drugs); and the use of "hard drugs" such as cocaine or heroin. The dimension possesses excellent Guttman-scale properties in both national samples as well as in subsamples differing in gender and ethnic background. The ordering of the levels of involvement was confirmed by the ordering of the alcohol-drug involvement groups based on their mean scores on measures of psychosocial proneness for involvement in problem behavior. The excessive use of a licit drug, i.e., problem drinking, appears to indicate greater involvement in drug use than does the use of an illicit drug, marijuana. This finding points to the importance of distinguishing between use and problem use of drugs in efforts to understand adolescent drug involvement.

Donovan, J E; Jessor, R

1983-01-01

39

A fixed grid numerical methodology for phase change problems involving a moving heat source  

Microsoft Academic Search

A numerical method for solving phase change problems involving a moving heat source is presented and illustrated by a two-dimensional example. The method uses a fixed grid and does not require the implementation of the Stefan condition at the solid-liquid interface; the procedure can thus be easily implemented using existing fixed grid codes. The problem considered as an example involves

C. Prakash; M. Samonds; A. K. Singhal

1987-01-01

40

Development of a Problem Solving Inventory Involving Three-Dimensional Models of Problem Situations.  

ERIC Educational Resources Information Center

A new form of the Purdue Elementary Problem Solving Inventory which presents real-life problem situations as three-dimensional models is described and developmental data is presented. Second and fourth graders in an advantaged and a disadvantaged school were given either the model version or the original slide version of the Inventory. The model…

Ringenbach, Susan; And Others

41

Child involvement in interparental conflict and child adjustment problems: a longitudinal study of violent families.  

PubMed

This study examined whether child involvement in interparental conflict predicts child externalizing and internalizing problems in violent families. Participants were 119 families (mothers and children) recruited from domestic violence shelters. One child between the ages of 7 and 10 years in each family (50 female, 69 male) completed measures of involvement in their parents' conflicts, externalizing problems, and internalizing problems. Mothers completed measures of child externalizing and internalizing problems, and physical intimate partner violence. Measures were completed at three assessments, spaced 6 months apart. Results indicated that children's involvement in their parents' conflicts was positively associated with child adjustment problems. These associations emerged in between-subjects and within-subjects analyses, and for child externalizing as well as internalizing problems, even after controlling for the influence of physical intimate partner violence. In addition, child involvement in parental conflicts predicted later child reports of externalizing problems, but child reports of externalizing problems did not predict later involvement in parental conflicts. These findings highlight the importance of considering children's involvement in their parents' conflicts in theory and clinical work pertaining to high-conflict families. PMID:24249486

Jouriles, Ernest N; Rosenfield, David; McDonald, Renee; Mueller, Victoria

2014-07-01

42

Image theory for electrostatic and magnetostatic problems involving a material sphere  

NASA Astrophysics Data System (ADS)

The well-known image method for a conducting sphere in front of an electrostatic source, due to Lord Kelvin from 1848, is generalized for electrostatic problems involving a dielectric sphere and for magnetostatic problems involving a permeable sphere. It is seen that the image sources are very simple, for a point source they consist of a point source plus a line source obeying a simple power law. The expressions are checked to satisfy all known limit cases. The image theory can be applied with simple computing devices for static or quasistatic problems involving material spheres.

Lindell, Ismo V.

1993-01-01

43

On Solving Elastic Waveguide Problems Involving Non-Mixed Edge Conditions.  

National Technical Information Service (NTIS)

Within the framework of the 'exact' linear theory an important class of wave propagation problems in elastic waveguides, involving non-mixed edge conditions (like stress or displacement), have remained unsolved. Basically, this is because known separation...

J. Miklowitz

1967-01-01

44

A fixed grid numerical methodology for phase change problems involving a moving heat source  

NASA Technical Reports Server (NTRS)

A numerical method for solving phase change problems involving a moving heat source is presented and illustrated by a two-dimensional example. The method uses a fixed grid and does not require the implementation of the Stefan condition at the solid-liquid interface; the procedure can thus be easily implemented using existing fixed grid codes. The problem considered as an example involves natural convection flow in the molten metal during tungsten inert gas welding.

Prakash, C.; Samonds, M.; Singhal, A. K.

1987-01-01

45

Physics Suite Sample Problems: Circular and Rotational Motion  

NSDL National Science Digital Library

This page contains a series of problems on the topic of circular and rotational motion developed for use with The Physics Suite, an activity-based learning project. Each problem was designed to help build qualitative understanding of physics and was built around student acquisition of knowledge as observed in recent studies. The problems vary in format and include estimation, context-based reasoning, multiple choice, short answer, qualitative questions, and essay questions. Topics covered include rotational energy, torque, angular momentum, and rotational kinematics. This item is part of a larger collection of problems, in-class questions, and interactive resources developed by the University of Maryland Physics Education Research Group.

Redish, Edward F.

2008-07-18

46

COMPARISON OF ECOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS  

EPA Science Inventory

Obtaining an adequate, representative sample of ecological communities to make taxon richness (TR) or compositional comparisons among sites is a continuing challenge. Sample representativeness literally means the similarity in species composition and relative abundance between a ...

47

COMPARISON OF BIOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS  

EPA Science Inventory

Obtaining an adequate, representative sample of biological communities or assemblages to make richness or compositional comparisons among sites is a continuing challenge. Traditionally, sample size is based on numbers of replicates or area collected or numbers of individuals enum...

48

Relationship of the Family Environment to Children's Involvement in Bully\\/Victim Problems at School  

Microsoft Academic Search

Previous studies regarding the relationship of the family environment to children's involvement in bully\\/victim problems at school primarily focused on children's perceptions of family dimensions. No studies were known using data from multiple reporters within 1 family (parents and children) on family characteristics of bully\\/victim problems. The aim of this study was to investigate differences between families of victims, bullies,

V. Stevens; I. De Bourdeaudhuij; P. Van Oost

2002-01-01

49

Application of the important sampling method to Vehicle Routing Problem with weight coefficients and Stochastic Demands  

Microsoft Academic Search

Vehicle Routing Problem has been approved a NP problem and it belongs to classical Combination Optimization hard problem. An effective algorithm based on Important Sampling is designed to solve the model which named Vehicle Routing Problem with Weight Coefficients and Stochastic Demands (WVRPSD). The optimal importance sampling distribution function was obtained by making use of the expection constructed by likelihood

Yue Qiu

2010-01-01

50

Problem Solving Process Research of Everyone Involved in Innovation Based on CAI Technology  

NASA Astrophysics Data System (ADS)

It is very important that non-technical department personnel especially bottom line employee serve as innovators under the requirements of everyone involved in innovation. According the view of this paper, it is feasible and necessary to build everyone involved in innovation problem solving process under Total Innovation Management (TIM) based on the Theory of Inventive Problem Solving (TRIZ). The tools under the CAI technology: How TO mode and science effects database could be very useful for all employee especially non-technical department and bottom line for innovation. The problem solving process put forward in the paper focus on non-technical department personnel especially bottom line employee for innovation.

Chen, Tao; Shao, Yunfei; Tang, Xiaowo

51

An empirical coverage test for the g-sample problem  

USGS Publications Warehouse

A nonparametric g-sample empirical coverage test has recently been developed for univariate continuous data. It is based upon the empirical coverages which are spacings of multiple random samples. The test is capable of detecting any distributional differences which may exist among the parent populations, without additional assumptions beyond randomness and continuity. The test can be effective with the limited and/or unequal sample sizes most often encountered in geologic studies. A computer program for implementing this procedure, G-SECT 1, is available. ?? 1991 International Association for Mathematical Geology.

Orlowski, L. A.; Grundy, W. D.; Mielke, Jr. , P. W.

1991-01-01

52

The effect of unlabeled samples in reducing the small sample size problem and mitigating the Hughes phenomenon  

Microsoft Academic Search

The authors study the use of unlabeled samples in reducing the problem of small training sample size that can severely affect the recognition rate of classifiers when the dimensionality of the multispectral data is high. The authors show that by using additional unlabeled samples that are available at no extra cost, the performance may be improved, and therefore the Hughes

Behzad M. Shahshahani; David A. Landgrebe

1994-01-01

53

Sampling an unknown universe: problems of researching mass casualty incidents (a history of ECRU's field research).  

PubMed

This paper reviews how the Emergency Communications Research Unit (ECRU) at Carleton University in Ottawa, Canada, developed its field research techniques with emphasis on some of its approaches to sampling. Then based on ECRU's experience, it discusses the problems that would arise if an attempt were made to research an incident involving not only mass casualties, but also chemically contaminated mass casualties. While ECRU's findings have been published in scores of book chapters, monographs and academic and other articles, this is only the second time since 1977 that its methods have been described [The Development of a Standby Research Capacity at Carleton University. Emergency Planning: Ottawa, Canada; Int. J. Mass Emergencies and Disasters 1977; 2(1):35-41; Methods of Disaster Research. Xlibris Corporation, 26-302], and the very first time its approaches to sampling have been discussed. PMID:17256806

Scanlon, Joseph

2007-04-15

54

Biased Sampling and PCK: The Case of the Marijuana Problem  

ERIC Educational Resources Information Center

As part of an interview protocol investigating teachers' pedagogical content knowledge (PCK) in statistics, 40 teachers were presented with a newspaper article reporting a phone-in survey about the legalisation of marijuana. The article and a question about the reliability of the sample had earlier been used in student surveys, and three student…

Watson, Jane M.; Nathan, Erica L.

2010-01-01

55

A Biweight Approach to the One-Sample Problem.  

National Technical Information Service (NTIS)

A 't'-like statistic, replacing the classical mean by a biweight in the numerator and the sample variance by a corresponding variance term in the denominator that modifies that used by Gross is proposed and evaluated for its efficiency in constructing con...

K. Kafadar

1979-01-01

56

A Kernel Method for the Two-Sample Problem  

Microsoft Academic Search

We propose a framework for analyzing and comparing distributions, allowing us to design statistical tests to determine if two samples are drawn from different distributions. Our test statistic is the largest difference in expectations over functions in the unit ball of a reproducing kernel Hilbert space (RKHS). We present two tests based on large deviation bounds for the test statistic,

Arthur Gretton; Karsten M. Borgwardt; Malte J. Rasch; Bernhard Scholkopf; Alexander J. Smola

2008-01-01

57

A resolution of the ascertainment sampling problem. II. Generalizations and numerical results.  

PubMed Central

The ascertainment problem arises when families are sampled by a nonrandom process and some assumption about this sampling process must be made in order to estimate genetic parameters. Under classical ascertainment assumptions, estimation of genetic parameters cannot be separated from estimation of the parameters of the ascertainment process, so that any misspecification of the ascertainment process causes biases in estimation of the genetic parameters. Ewens and Shute proposed a resolution to this problem, involving conditioning the likelihood of the sample on the part of the data which is "relevant to ascertainment." The usefulness of this approach can only be assessed by examining the properties (in particular, bias and standard error) of the estimates which arise by using it for a wide range of parameter values and family size distributions and then comparing these biases and standard errors with those arising under classical ascertainment procedures. These comparisons are carried out in the present paper, and we also compare the proposed method with procedures which condition on, or ignore, parts of the data.

Shute, N C; Ewens, W J

1988-01-01

58

Negative Peer Involvement in Multisystemic Therapy for the Treatment of Youth Problem Behavior: Exploring Outcome and Process Variables in “Real-World” Practice  

Microsoft Academic Search

Associating with a negative peer group is related to involvement in problem behavior, yet very little research has considered the role of negative peer group affiliations in the context of “real-world” community-based treatments for problem behavior. This study examined the effects of negative peer involvement on case closure status and treatment characteristics in a large sample (N = 1,341) of adolescents (M

Paul Boxer

2011-01-01

59

NASTRAN thermal analyzer: Theory and application including a guide to modeling engineering problems, volume 2. [sample problem library guide  

NASA Technical Reports Server (NTRS)

A sample problem library containing 20 problems covering most facets of Nastran Thermal Analyzer modeling is presented. Areas discussed include radiative interchange, arbitrary nonlinear loads, transient temperature and steady-state structural plots, temperature-dependent conductivities, simulated multi-layer insulation, and constraint techniques. The use of the major control options and important DMAP alters is demonstrated.

Jackson, C. E., Jr.

1977-01-01

60

Suicidal Ideation among Adolescent School Children, Involvement in Bully-Victim Problems, and Perceived Social Support.  

ERIC Educational Resources Information Center

Results of self-reports and peer nomination procedures to identify bullies and victims indicated that involvement in bully-victim problems at school, especially for students with relatively little social support, was significantly related to degree of suicidal ideation. (Author/JDM)

Rigby, Ken; Slee, Phillip

1999-01-01

61

A method to solve an acoustic inverse scattering problem involving smart obstacles  

Microsoft Academic Search

A time-harmonic acoustic inverse scattering problem involving smart obstacles is formulated and a method to solve it is proposed. A smart obstacle is an obstacle that, when hit by an incoming acoustic wave, tries to pursue a given goal circulating a suitable pressure current on its boundary. A pressure current is a quantity whose physical dimension is pressure divided by

L. Fatone; M. C. Recchioni; F. Zirilli

2006-01-01

62

Semantic Structures of One-Step Word Problems Involving Multiplication or Division.  

ERIC Educational Resources Information Center

Proposes a four-category classification of semantic structures of one-step word problems involving multiplication and division: forming the n-th multiple of measures, combinatorial multiplication, composition of operators, and multiplication by formula. This classification is compatible with semantic structures of addition and subtraction word…

Schmidt, Siegbert; Weiser, Werner

1995-01-01

63

Concurrent Mental Health and Substance Use Problems among Street-Involved Youth  

ERIC Educational Resources Information Center

Among marginalized populations, homeless adults are known to have elevated rates of mental health and substance use problems compared to the general population, but less is known about their youthful homeless counterparts. While few studies currently exist, what research has been conducted among street-involved youth has confirmed high rates of…

Kirst, Maritt; Frederick, Tyler; Erickson, Patricia G.

2011-01-01

64

Determinants of maltreatment substantiation in a sample of infants involved with the child welfare system  

Microsoft Academic Search

Children under one year of age are highly vulnerable to child maltreatment, which can lead to serious immediate and long-term physical and mental health consequences. Child welfare workers encounter unique challenges when assessing allegations of maltreatment involving infants. This study identifies correlates of maltreatment substantiation in a sample of 793 infants less than one year of age investigated by child

Gabriela Williams; Lil Tonmyr; Susan M. Jack; Barbara Fallon; Harriet L. MacMillan

2011-01-01

65

Numerical methods for singular boundary value problems involving the p-laplacian  

NASA Astrophysics Data System (ADS)

In this work, we are concerned about a singular boundary value problem for a nonlinear ordinary differential equation involving the N-dimensional p-laplacian. This equation may be considered as a generalized Emden-Fowler equation and arises in models of fluid mechanics, elasticity theory and other fields of physics. The main feature of the considered boundary value problem is that it has two singularities at the endpoints of the considered interval. We analyze the asymptotic behavior of the solutions near these singularities and propose computational methods that take this behavior into consideration. Numerical examples are presented and dicussed.

Lima, Pedro; Morgado, Luisa

2009-05-01

66

A new LDA-based face recognition system which can solve the small sample size problem  

Microsoft Academic Search

A new LDA-based face recognition system is presented in this paper. Linear discriminant analysis (LDA) is one of the most popular linear projection techniques for feature extraction. The major drawback of applying LDA is that it may encounter the small sample size problem. In this paper, we propose a new LDA-based technique which can solve the small sample size problem.

Li-fen Chen; Hong-yuan Mark Liao; Ming-tat Ko; Ja-chen Lin; Gwo-jong Yu

2000-01-01

67

Quality Control and Flux Sampling Problems for Tower and Aircraft Data  

Microsoft Academic Search

A series of automated tests is developed for tower and aircraft time series to identify instrumentation problems, flux sampling problems, and physically plausible but unusual situations. The automated procedures serve as a safety net for quality controlling data. A number of special flags are developed representing a variety of potential problems such as inconsistencies between different tower levels and the

Dean Vickers; L. Mahrt

1997-01-01

68

Hybrid transfinite element modeling/analysis of nonlinear heat conduction problems involving phase change  

NASA Technical Reports Server (NTRS)

The present paper describes the applicability of hybrid transfinite element modeling/analysis formulations for nonlinear heat conduction problems involving phase change. The methodology is based on application of transform approaches and classical Galerkin schemes with finite element formulations to maintain the modeling versatility and numerical features for computational analysis. In addition, in conjunction with the above, the effects due to latent heat are modeled using enthalpy formulations to enable a physically realistic approximation to be dealt computationally for materials exhibiting phase change within a narrow band of temperatures. Pertinent details of the approach and computational scheme adapted are described in technical detail. Numerical test cases of comparative nature are presented to demonstrate the applicability of the proposed formulations for numerical modeling/analysis of nonlinear heat conduction problems involving phase change.

Tamma, Kumar K.; Railkar, Sudhir B.

1988-01-01

69

Concurrent Mental Health and Substance Use Problems among Street-Involved Youth  

Microsoft Academic Search

Among marginalized populations, homeless adults are known to have elevated rates of mental health and substance use problems\\u000a compared to the general population, but less is known about their youthful homeless counterparts. While few studies currently\\u000a exist, what research has been conducted among street-involved youth has confirmed high rates of comorbidity among this population.\\u000a However, few of these studies explore

Maritt Kirst; Tyler Frederick; Patricia G. Erickson

70

12-Step involvement among a U.S. national sample of Oxford House residents  

PubMed Central

A longitudinal analysis was conducted among a U.S. national sample of persons affiliated with Alcoholics Anonymous and Narcotics Anonymous living in self-run recovery homes (Oxford Houses). Categorical involvement in a set of 12-step activities (i.e., having a sponsor, reading 12-step literature, doing service work, and calling other members for help) and averaged summary scores of involvement were examined in relation to abstinence and self-efficacy for abstinence. Participants who were categorically involved in all 12-step activities reported significantly higher levels of abstinence and self-efficacy for abstinence at 1 year compared with those who were less involved, whereas averaged summary scores of involvement were not a significant predictor of abstinence. Participants’ number of days in Oxford Houses, but not rates of 12-step meeting attendance, was significantly related to increased abstinence. Findings suggest that categorical involvement in a number of 12-step activities equip persons with substance use disorders with resources for ongoing recovery.

Majer, John M.; Jason, Leonard A.; Ferrari, Joseph R.; Miller, Steve A.

2011-01-01

71

A Hybrid Computer Program for Rapidly Solving Flowing or Static Chemical Kinetic Problems Involving Many Chemical Species.  

National Technical Information Service (NTIS)

A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and prel...

A. G. Mclain C. S. R. Rao

1976-01-01

72

Outcome of treatment for alcohol abuse and involvement in alcoholics anonymous among previously untreated problem drinkers  

Microsoft Academic Search

A sample of 515 initially untreated problem drinkers was followed for one year after contacting alcohol information and referral\\u000a or detoxification services. At a one-year follow-up, participants had self-selected into one of four groups: no treatment\\u000a (24%), Alcoholics Anonymous (AA) only (18%), outpatient treatment (25%), and residential or inpatient treatment (32%); some\\u000a outpatients also attended AA, and some inpatients also

Christine Timko; Rudolf H. Moos; John W. Finney; Bernice S. Moos

1994-01-01

73

A microscopic derivation of macroscopic sharp interface problems involving phase transitions  

NASA Astrophysics Data System (ADS)

Macroscopic free boundary problems involving phase transitions (e.g., the classical Stefan problem or its modifications) are derived in a unified way from a Hamiltonian based on a general set of microscopic interactions. A Hamiltonian of the form ? + ? x, x' J( x- x') ?( x) ?( x') leads to differential equations as a result of Fourier transforms. Expanding the Fourier transform of J in powers of q (the wave number), one can truncate the series at an arbitrary order M, and thereby obtain Mth-order differential equations. An asymptotic analysis of these equations in various scalings of the physical parameters then implies limits which are the standard macroscopic models for the dynamics of phase boundaries.

Caginalp, G.

1990-05-01

74

The people problems of NEPA: Social impact assessment and the role of public involvement  

SciTech Connect

This Chapter of the book The Scientific Challenges of NEPA'' discusses the people problems of NEPA and social impact assessment and the role of public involvement in NEPA. When Congress passed the National Environmental Policy Act (NEPA) in 1969, there was little guidance on the preparation of environmental impact statements (EIS) and the role of the public in the NEPA process. Excepting the statutory language of NEPA, which referred to impacts on the human environment, nowhere was this more evident than with respect to people. Questions such as what impacts on people should be assessed, how impacts on people should be assessed, and how people, including but not limited to those persons potentially impacted, should be involved in the assessment itself as well as NEPA's associated administrative processes, were simply not addressed.

Carnes, S.A.

1989-01-01

75

The people problems of NEPA: Social impact assessment and the role of public involvement  

SciTech Connect

This Chapter of the book `` The Scientific Challenges of NEPA`` discusses the people problems of NEPA and social impact assessment and the role of public involvement in NEPA. When Congress passed the National Environmental Policy Act (NEPA) in 1969, there was little guidance on the preparation of environmental impact statements (EIS) and the role of the public in the NEPA process. Excepting the statutory language of NEPA, which referred to impacts on the human environment, nowhere was this more evident than with respect to people. Questions such as what impacts on people should be assessed, how impacts on people should be assessed, and how people, including but not limited to those persons potentially impacted, should be involved in the assessment itself as well as NEPA`s associated administrative processes, were simply not addressed.

Carnes, S.A.

1989-12-31

76

On the application of the genetic algorithm to the predictability problems involving "on-off" switches  

NASA Astrophysics Data System (ADS)

On the application of the genetic algorithm to the predictability problems involving "on-off" switches ZHENG Qin(1,2), DAI Yi(1), ZHANG Lu(1)and LU Xiaoqing(1) (1)Institute of Science, PLA University of Science and Technology, Nanjing 211101, China; (2)State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China Abstract The lower bound of maximum predictable time can be formulated into a constrained nonlinear optimization problem, and the traditional solution to this problem is the filtering method and the conditional nonlinear optimal perturbation (CNOP) method. Usually, the CNOP method is implemented with the help of a gradient descent algorithm based on the adjoint method, which is named as the ADJ-CNOP, hereinafter. However, with the increasing improvement of actual prediction models, more and more physical processes are taken into consideration in models in the form of parameterization, thus giving rise to the "on-off" switch problem, which affects tremendously the effectiveness of the conventional gradient descent algorithm based on the adjoint method. This paper attempts to apply a genetic algorithm (GA) to the CNOP method, named as the GA-CNOP, to solve the predictability problems involving the "on-off" switches. As the precision of the filtering method depends uniquely on the division of the constraint region, its results are taken as benchmarks and a series of comparisons between the ADJ-CNOP and the GA-CNOP are performed. It is revealed that the GA-CNOP can always figure out the accurate lower bound of maximum predictable time even in discontinuous cases, while the ADJ-CNOP, owing to the effect of "on-off" switches, often yields the incorrect lower bound of maximum predictable time. This would suggest that in non-smooth cases, using a GA to solve the predictability problems is more effective than using the conventional optimization algorithm based on gradients, as long as the genetic operators are properly configured.

Zheng, Q.

2011-12-01

77

Parent-Reported Feeding and Feeding Problems in a Sample of Dutch Toddlers  

ERIC Educational Resources Information Center

Little is known about the feeding behaviors and problems with feeding in toddlers. In the present questionnaire study, data were collected on the feeding behaviors and feeding problems in a relatively large (n = 422) sample of Dutch healthy toddlers (i.e. 18-36 months old) who lived at home with their parents. Results show that three meals a day…

de Moor, Jan; Didden, Robert; Korzilius, Hubert

2007-01-01

78

A Model for Predicting Behavioural Sleep Problems in a Random Sample of Australian Pre-Schoolers  

ERIC Educational Resources Information Center

Behavioural sleep problems (childhood insomnias) can cause distress for both parents and children. This paper reports a model describing predictors of high sleep problem scores in a representative population-based random sample survey of non-Aboriginal singleton children born in 1995 and 1996 (1085 girls and 1129 boys) in Western Australia.…

Hall, Wendy A.; Zubrick, Stephen R.; Silburn, Sven R.; Parsons, Deborah E.; Kurinczuk, Jennifer J.

2007-01-01

79

Collective Socialization and Child Conduct Problems: A Multilevel Analysis with an African American Sample  

ERIC Educational Resources Information Center

This article uses hierarchical linear modeling with a sample of African American children and their primary caregivers to examine the association between various community factors and child conduct problems. The analysis revealed a rather strong inverse association between level of collective socialization and conduct problems. This relationship…

Simons, Leslie Gordon; Simons, Ronald L.; Conger, Rand D.; Brody, Gene H.

2004-01-01

80

Trace Chlorinated Organics Analysis in Highly Radioactive Samples-Problems and Solutions  

SciTech Connect

This paper discusses some of the problems that are associated with the analysis of highly radioactive samples for chlorinated organic compounds at the part per trillion level. To date, both high fission product activity and transuranic activity have been handle successfully. Communication issues, sample handling, transfer between laboratories and analytical challenges are discussed.

Macek, P.; Hawthorne, L.; Hass, J. R.; Harvan, D.

2002-02-26

81

An easy-to-implement numerical simulation method for adhesive contact problems involving asymmetric adhesive contact  

NASA Astrophysics Data System (ADS)

A novel numerical method to solve asymmetric adhesive contact problems in rectangular coordinates has been developed. Surface interaction is modelled using an interface potential, deformation is coupled using Green's functions for a half space, and the resulting system of equations is solved by a relaxation technique. The method can handle arbitrary surface topography and properties. Compared with previous methods, this numerical scheme is much easier to implement and is just as accurate. Here, it is applied to two adhesive contact problems: one between a sphere and a cylinder; and the other between two identical cylinders in oblique contact. The numerical results reveal inaccuracies in elliptical contact theory when the skew angles between the two cylinders are small and the resulting contact is highly eccentric. The pull-off forces show an indiscernible decrease with decreasing value of the skew angle, which is quite different from the elliptical JKR theory. This technique can be used to solve adhesive contact problems that involve partial contact or complex geometry, such as rippled or rough surfaces.

Jin, Congrui; Jagota, Anand; Hui, Chung-Yuen

2011-10-01

82

Determination of ethyl glucuronide in hair: a rapid sample pretreatment involving simultaneous milling and extraction.  

PubMed

A combination of simultaneous milling and extraction known as micropulverized extraction was developed for the quantification of the alcohol marker ethyl glucuronide (EtG) in hair samples using a homogeneous reference material and a mixer mill. Best extraction results from 50 mg of hair were obtained with 2-mL plastic tubes containing two steel balls (? = 5 mm), 0.5 mL of water and with an oscillating frequency of 30 s(-1) over a period of 30 min. EtG was quantified employing a validated GC-MS procedure involving derivatization with pentafluoropropionic acid anhydride. This micropulverization procedure was compared with dry milling followed by separate aqueous extraction and with aqueous extraction after manual cutting to millimeter-size snippets. Micropulverization yielded 28.0?±?1.70 pg/mg and was seen to be superior to manually cutting (23.0?±?0.83 pg/mg) and equivalent to dry grinding (27.7?±?1.71 pg/mg) with regard to completeness of EtG extraction. The option to process up to 20 samples simultaneously makes micropulverization especially valuable for the high throughput of urgent samples. PMID:24221575

Mönch, Bettina; Becker, Roland; Nehls, Irene

2014-01-01

83

Exact image method for Gaussian beam problems involving a planar interface  

NASA Technical Reports Server (NTRS)

Exact image method, recently introduced for the solution of electromagnetic field problems involving sources above a planar interface or two homogeneous media, is shown to be valid also for sources located in complex space, which makes its application possible for Gaussian beam analysis. It is demonstrated that the Goos-Hanchen shift and the angular shift of a TE polarized beam are correctly given as asymptotic results by the exact reflection image theory. Also, the apparent image location giving the correct Gaussian beam transmitted through the interface is obtained as another asymptotic check. The present theory makes it possible to calculate the exact coupling from the Gaussian beam to the reflected and refracted beams, as well as to the surface wave.

Lindell, I. V.

1987-01-01

84

Negative peer involvement in multisystemic therapy for the treatment of youth problem behavior: exploring outcome and process variables in "real-world" practice.  

PubMed

Associating with a negative peer group is related to involvement in problem behavior, yet very little research has considered the role of negative peer group affiliations in the context of "real-world" community-based treatments for problem behavior. This study examined the effects of negative peer involvement on case closure status and treatment characteristics in a large sample (N = 1,341) of adolescents (M age = 15.3 years, SD = 1.5 years) enrolled in Multisystemic Therapy services. Data were drawn from the clinical records of a nonprofit youth and family services provider. Findings suggest that negative peer involvement is significantly related to treatment failure, particularly when negative peer involvement is comprised of gang affiliation. PMID:22023276

Boxer, Paul

2011-01-01

85

A hybrid computer program for rapidly solving flowing or static chemical kinetic problems involving many chemical species  

NASA Technical Reports Server (NTRS)

A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.

Mclain, A. G.; Rao, C. S. R.

1976-01-01

86

Factorial dimensions of the Revised Behavior Problem Checklist: Replication and validation within a kindergarten sample  

Microsoft Academic Search

The factor structure of the Revised Behavior Problem Checklist (RBPC) was examined in a large sample of suburban kindergarten children. Teacher-rated dimensions of Conduct Disorder, Attention Problems-Immaturity, Anxiety-Withdrawal, and Psychotic Behavior were closely replicated, and a new factor labeled Unmotivated-Isolated was also revealed. These principal components were consistent across gender and across subsamples of children differing as to risk status

Stephen P. Hinshaw; Delmont C. Morrison; Estol T. Carte; Carol Cornsweet

1987-01-01

87

2-SPRT'S and The Modified Kiefer-Weiss Problem of Minimizing an Expected Sample Size  

Microsoft Academic Search

A simple combination of one-sided sequential probability ratio tests, called a 2-SPRT, is shown to approximately minimize the expected sample size at a given point $\\\\theta_0$ among all tests with error probabilities controlled at two other points, $\\\\theta_1$ and $\\\\theta_2$. In the symmetric normal and binomial testing problems, this result applies directly to the Kiefer-Weiss problem of minimizing the maximum

Gary Lorden

1976-01-01

88

Drug use and drug problems among teenagers in a household sample.  

PubMed

Studies of drug use among young persons have typically employed students or special high risk groups rather than general samples. This study reports drug use among a household sample of persons aged 14 to 18. The results indicate that cannabis was the most frequently used drug. Factors associated with drug problems were: being older, living in cities, not participating in religious activities and being a worker rather than a student. Very few of those with problems had been treated or felt the need for any treatment. PMID:7353475

Smart, R G; Blair, N L

1980-03-01

89

A genetic algorithm applied to graph problems involving subsets of vertices  

Microsoft Academic Search

Many graph problems seek subsets of their vertices that maximize or minimize objective functions on the vertices. Among these are the capacitated p-median problem, the geometric connected dominating set problem, the capacitated k-center problem, and the traveling tourist problem. Prior genetic algorithms research in this area applied a simple mutation of an allele by random replacement. Recently an enhanced operator

Yaser Alkhalifah; Roger L. Wainwright

2004-01-01

90

Word Problems  

NSDL National Science Digital Library

This FAQ about solving word problems from the Ask Dr. Math service of the Math Forum @ Drexel outlines strategies for solving word problems. The response includes general strategies that apply to problem solving, as well as a specific sample problem involving distance, rate, and time.

Math Forum, Ask D.; The Math Forum @ Drexel

1996-01-01

91

Sampling  

NSDL National Science Digital Library

This webpage contains three activities that have students work through problems associated with sampling. Each activity includes a brief description, materials list, and a set of lesson worksheets. The last activity on the page, the "Cereal Toy Investigation" also includes an online simulator in the form of a Java applet.

Kawas, Terry

2012-01-01

92

Energy and the Confused Student V: The Energy/Momentum Approach to Problems Involving Rotating and Deformable Systems  

ERIC Educational Resources Information Center

Energy is a critical concept in physics problem-solving, but is often a major source of confusion for students if the presentation is not carefully crafted by the instructor or the textbook. A common approach to problems involving deformable or rotating systems that has been discussed in the literature is to employ the work-kinetic energy theorem…

Jewett, John W., Jr.

2008-01-01

93

Caregiver Reports of Sleep Problems on a Convenience Sample of Children with Fragile X Syndrome  

ERIC Educational Resources Information Center

Caregivers reported on sleep in a convenience sample of 90 children with fragile X syndrome utilizing a standardized assessment tool, the Children's Sleep Habits Questionnaire (CSHQ), and a 14-day sleep diary. CSHQ data indicated that 47% of participants had sleep problems at a level that suggested referral and further evaluation. Sleep diary data…

Kronk, Rebecca; Dahl, Ronald; Noll, Robert

2009-01-01

94

A Study on Three Linear Discriminant Analysis Based Methods in Small Sample Size Problem  

Microsoft Academic Search

In this paper, we make a study on three linear discriminant analysis (LDA) based methods: regularized discriminant analysis (RDA), discriminant common vectors (DCV) and maximal margin criterion (MMC) in the small sample size (SSS) problem. Our contributions are that: (1) we reveal that DCV obtains the same projection subspace as both RDA and wMMC (weighted MMC, a general form of

Jun Liu; Songcan Chen; Xiaoyang Tan

2008-01-01

95

The Statistical Analysis of Mitochondrial DNA Polymorphisms: X * and the Problem of Small Samples  

Microsoft Academic Search

Significance levels obtained from a x2 contingency test are suspect when sample sizes are small. Traditionally this has meant that data must be combined. However, such an approach may obscure heterogeneity and hence potentially reduce the power of the statistical test. In this paper, we present a Monte Carlo solution to this problem: by this method, no lumping of data

Derek A. Roff; Paul Bentzen

96

A new proof of geometric convergence for general transport problems based on sequential correlated sampling methods  

NASA Astrophysics Data System (ADS)

In [J. Halton, Sequential Monte Carlo, Proc. Comb. Phil. Soc. 58 (1962), J. Halton, Sequential Monte Carlo Techniques for the Solution of Linear Systems, J. Sci. Comp. 9 (1994) 213-257] Halton introduced a strategy to be used in Monte Carlo algorithms for the efficient solution of certain matrix problems. We showed in [R. Kong, J. Spanier, Sequential correlated sampling methods for some transport problems, in: Harold Niederreiter, Jerome Spanier (Eds.), Monte-Carlo and Quasi Monte-Carlo Methods 1998: Proceedings of a Conference at the Claremont Graduate University, Springer-Verlag, New York, 2000, R. Kong, J. Spanier, Error analysis of sequential Monte Carlo methods for transport problems, in: Harold Niederreiter, Jerome Spanier (Eds.), Monte-Carlo and Quasi Monte-Carlo Methods 1998: Proceedings of a Conference at the Claremont Graduate University, Springer-Verlag, New York, 2000] how Halton's method based on correlated sampling can be extended to continuous transport problems and established their geometric convergence for a family of transport problems in slab geometry. In our algorithm, random walks are processed in batches, called stages, each stage producing a small correction that is added to the approximate solution developed from the previous stages. In this paper, we demonstrate that strict error reduction from stage to stage can be assured under rather general conditions and we illustrate this rapid convergence numerically for a simple family of two dimensional transport problems.

Kong, Rong; Spanier, Jerome

2008-12-01

97

An algorithm for the weighting matrices in the sampled-data optimal linear regulator problem  

NASA Technical Reports Server (NTRS)

The sampled-data optimal linear regulator problem provides a means whereby a control designer can use an understanding of continuous optimal regulator design to produce a digital state variable feedback control law which satisfies continuous system performance specifications. A basic difficulty in applying the sampled-data regulator theory is the requirement that certain digital performance index weighting matrices, expressed as complicated functions of system matrices, be computed. Infinite series representations are presented for the weighting matrices of the time-invariant version of the optimal linear sampled-data regulator problem. Error bounds are given for estimating the effect of truncating the series expressions after a finite number of terms, and a method is described for their computer implementation. A numerical example is given to illustrate the results.

Armstrong, E. S.; Caglayan, A. K.

1976-01-01

98

Personal values and involvement in problem behaviors among Bahamian early adolescents: a cross-sectional study  

Microsoft Academic Search

BACKGROUND: Few studies, particularly in developing countries, have explored the relationship between adolescents and parental values with adolescent problem behaviors. The objectives of the study are to (1) describe adolescents' personal values, their problem behaviors, and the relationships thereof according to gender and (2) examine the relationship between parental values, adolescent values, and adolescents' problem behaviors among sixth-grade students and

Hongjie Liu; Shuli Yu; Lesley Cottrell; Sonja Lunn; Lynette Deveaux; Nanika V Brathwaite; Sharon Marshall; Xiaoming Li; Bonita Stanton

2007-01-01

99

Five Confidence Intervals of the Closed Population Size in the Capture-recapture Problem under Inverse Sampling with Replacement  

Microsoft Academic Search

Summary In the capture-recapture problem for two independent samples, the traditional estimator, calculated as the product of the two sample sizes divided by the number of sampled subjects appearing commonly in both samples, is well known to be a biased estimator of the population size and have no finite variance under direct or binomial sampling. To alleviate these theoretical limitations,

Kung-Jong Lui

2004-01-01

100

A linear sampling method for near-field inverse problems in elastodynamics  

Microsoft Academic Search

The problem of reconstructing underground obstacles from near-field, surface seismic measurements is investigated within the framework of a linear sampling method. Although the latter approach has been the subject of mounting attention in inverse acoustics dealing with far-field wave patterns in infinite domains, there have apparently not been any attempts to apply this new method to the interpretation of near-field

Sylvain Nintcheu Fata; Bojan B. Guzina

2004-01-01

101

Exploring the Connection Between Sampling Problems in Bayesian Inference and Statistical Mechanics  

NASA Technical Reports Server (NTRS)

The Bayesian and statistical mechanical communities often share the same objective in their work - estimating and integrating probability distribution functions (pdfs) describing stochastic systems, models or processes. Frequently, these pdfs are complex functions of random variables exhibiting multiple, well separated local minima. Conventional strategies for sampling such pdfs are inefficient, sometimes leading to an apparent non-ergodic behavior. Several recently developed techniques for handling this problem have been successfully applied in statistical mechanics. In the multicanonical and Wang-Landau Monte Carlo (MC) methods, the correct pdfs are recovered from uniform sampling of the parameter space by iteratively establishing proper weighting factors connecting these distributions. Trivial generalizations allow for sampling from any chosen pdf. The closely related transition matrix method relies on estimating transition probabilities between different states. All these methods proved to generate estimates of pdfs with high statistical accuracy. In another MC technique, parallel tempering, several random walks, each corresponding to a different value of a parameter (e.g. "temperature"), are generated and occasionally exchanged using the Metropolis criterion. This method can be considered as a statistically correct version of simulated annealing. An alternative approach is to represent the set of independent variables as a Hamiltonian system. Considerab!e progress has been made in understanding how to ensure that the system obeys the equipartition theorem or, equivalently, that coupling between the variables is correctly described. Then a host of techniques developed for dynamical systems can be used. Among them, probably the most powerful is the Adaptive Biasing Force method, in which thermodynamic integration and biased sampling are combined to yield very efficient estimates of pdfs. The third class of methods deals with transitions between states described by rate constants. These problems are isomorphic with chemical kinetics problems. Recently, several efficient techniques for this purpose have been developed based on the approach originally proposed by Gillespie. Although the utility of the techniques mentioned above for Bayesian problems has not been determined, further research along these lines is warranted

Pohorille, Andrew

2006-01-01

102

Polygenic Scores Predict Alcohol Problems in an Independent Sample and Show Moderation by the Environment  

PubMed Central

Alcohol problems represent a classic example of a complex behavioral outcome that is likely influenced by many genes of small effect. A polygenic approach, which examines aggregate measured genetic effects, can have predictive power in cases where individual genes or genetic variants do not. In the current study, we first tested whether polygenic risk for alcohol problems—derived from genome-wide association estimates of an alcohol problems factor score from the age 18 assessment of the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 4304 individuals of European descent; 57% female)—predicted alcohol problems earlier in development (age 14) in an independent sample (FinnTwin12; n = 1162; 53% female). We then tested whether environmental factors (parental knowledge and peer deviance) moderated polygenic risk to predict alcohol problems in the FinnTwin12 sample. We found evidence for both polygenic association and for additive polygene-environment interaction. Higher polygenic scores predicted a greater number of alcohol problems (range of Pearson partial correlations 0.07–0.08, all p-values ? 0.01). Moreover, genetic influences were significantly more pronounced under conditions of low parental knowledge or high peer deviance (unstandardized regression coefficients (b), p-values (p), and percent of variance (R2) accounted for by interaction terms: b = 1.54, p = 0.02, R2 = 0.33%; b = 0.94, p = 0.04, R2 = 0.30%, respectively). Supplementary set-based analyses indicated that the individual top single nucleotide polymorphisms (SNPs) contributing to the polygenic scores were not individually enriched for gene-environment interaction. Although the magnitude of the observed effects are small, this study illustrates the usefulness of polygenic approaches for understanding the pathways by which measured genetic predispositions come together with environmental factors to predict complex behavioral outcomes.

Salvatore, Jessica E.; Aliev, Fazil; Edwards, Alexis C.; Evans, David M.; Macleod, John; Hickman, Matthew; Lewis, Glyn; Kendler, Kenneth S.; Loukola, Anu; Korhonen, Tellervo; Latvala, Antti; Rose, Richard J.; Kaprio, Jaakko; Dick, Danielle M.

2014-01-01

103

Parental Choices and Ethical Dilemmas Involving Disabilities: Special Education and the Problem of Deliberately Chosen Disabilities  

Microsoft Academic Search

Ethical issues regarding children with disabilities have long involved their treatment after they are born. These issues remain important, but children may be deliberately created with or without characteristics that are usually thought of as disabilities. Preimplantation genetic diagnosis (PGD) and related technologies that involve human reproduction will become more readily available and raise new issues about the nature of

James M. Kauffman; Daniel P. Hallahan

2009-01-01

104

Parental Choices and Ethical Dilemmas Involving Disabilities: Special Education and the Problem of Deliberately Chosen Disabilities  

ERIC Educational Resources Information Center

Ethical issues regarding children with disabilities have long involved their treatment after they are born. These issues remain important, but children may be deliberately created with or without characteristics that are usually thought of as disabilities. Preimplantation genetic diagnosis (PGD) and related technologies that involve human…

Kauffman, James M.; Hallahan, Daniel P.

2009-01-01

105

An Exploration of Family Problem-Solving and Affective Involvement as Moderators Between Disease Severity and Depressive Symptoms in Adolescents with Inflammatory Bowel Disease  

PubMed Central

Little is known about how family functioning relates to psychosocial functioning of youth with inflammatory bowel disease (IBD). The study aim was to examine family problem solving and affective involvement as moderators between adolescent disease severity and depressive symptoms. Participants were 122 adolescents with IBD and their parents. Measures included self-reported and parent-reported adolescent depressive symptoms, parent-reported family functioning, and physician-completed measures of disease severity. Disease severity was a significant predictor of adolescent-reported depressive symptoms, but not parent-reported adolescent depressive symptoms. Family affective involvement significantly predicted parent-reported adolescent depressive symptoms, while family problem-solving significantly predicted adolescent self-report of depressive symptoms. Neither affective involvement nor problem-solving served as moderators. Family affective involvement may play an important role in adolescent emotional functioning but may not moderate the effect of disease severity on depressive symptoms. Research should continue to examine effects of family functioning on youth emotional functioning and include a sample with a wider range of disease severity to determine if interventions aimed to enhance family functioning are warranted.

Schuman, Shana L.; Graef, Danielle M.; Janicke, David M.; Gray, Wendy N.; Hommel, Kevin A.

2014-01-01

106

Some Problems Involved in the Shared Cataloging Subsystem of the Ohio College Library Center.  

National Technical Information Service (NTIS)

This report outlines the development of the Ohio College Library Center (OCLC) and considers some basic problems in OCLC shared cataloging--e.g., the uneven quality of input cataloging and increasing number of duplicate records. Summaries of findings from...

M. T. Sacco

1977-01-01

107

Personal values and involvement in problem behaviors among Bahamian early adolescents: a cross-sectional study  

PubMed Central

Background Few studies, particularly in developing countries, have explored the relationship between adolescents and parental values with adolescent problem behaviors. The objectives of the study are to (1) describe adolescents' personal values, their problem behaviors, and the relationships thereof according to gender and (2) examine the relationship between parental values, adolescent values, and adolescents' problem behaviors among sixth-grade students and one of their parents. Methods The data used in these analyses were from the baseline assessment of a school-based HIV risk reduction intervention being conducted and evaluated among sixth grade students and one of their parents across 9 elementary schools in The Bahamas. Personal values were measured by the Portrait Values Questionnaire (PVQ). Seven reported problem behaviors were queried from the students, which included physical fight with a friend, drank alcohol, beer, or wine, smoked a cigarette, pushed or carried any drugs, carried a gun, knife, screwdriver or cutlass to use as a weapon, had sex and used marijuana or other illicit drugs over the past 6 months. Multilevel modeling for binary data was performed to estimate the associations between adolescent and parental values and adolescent problem behaviors. Results Among 785 students, 47% of the students reported at least one problem behavior. More boys (54%) reported having one or more problem behaviors than girls (41%, p < 0.01). Boys compared to girls expressed a higher level of self-enhancement (means score: 36.5 vs. 35.1; p = 0.03), while girls expressed a higher level of self-transcendence (42.3 vs. 40.7; p = 0.03). The results of multilevel modeling indicates that boys with a higher level of self-enhancement and girls with a higher level of openness to change and a lower level of conservation were more likely to report engagement in problem behaviors. Only two parental values (self-transcendence and conservation) were low or modestly correlated with youth' values (openness to change and self-enhancement). Parental-reported values documented limited association on adolescents' reported values and behaviors. Conclusion In designing interventions for reducing adolescents' problem behaviors, it may be important to understand the values associated with specific problem behaviors. Further exploration regarding lack of association between adolescent and parental values and problem behaviors is needed.

Liu, Hongjie; Yu, Shuli; Cottrell, Lesley; Lunn, Sonja; Deveaux, Lynette; Brathwaite, Nanika V; Marshall, Sharon; Li, Xiaoming; Stanton, Bonita

2007-01-01

108

Variants of callous-unemotional conduct problems in a community sample of adolescents.  

PubMed

Callous-unemotional traits are believed to be a childhood precursor to psychopathy, and among youth with conduct problems they designate those showing a particularly severe, stable, and aggressive pattern of antisocial behavior. Youth with callous-unemotional traits are a heterogeneous population and, analogous to adults with psychopathy, research suggests that lower anxious primary and high-anxious secondary variants exist. Using a community sample of 2,306 Greek-Cypriot adolescents (M age = 16 years; 49.7 % female), the first aim of the study was to examine whether variants of callous-unemotional traits could be identified using latent profile analysis of scores on measures of callous-unemotional traits, conduct problems, and anxiety. Additional aims of the study were to compare the identified clusters on external measures theorized to distinguish them (i.e., self-esteem, narcissism, impulsivity, sensation seeking and proactive/reactive aggression) and social factors relevant to adolescent development. Results indicated that, in addition to low risk (i.e., low scores on callous-unemotional traits, conduct problems, and anxiety) and anxious (i.e., high scores on anxiety, low scores on callous-unemotional traits and conduct problems) subgroups, two groups of youth scoring high on callous-unemotional traits and conduct problems were identified. High-anxious secondary callous-unemotional variants were distinguished by lower self-esteem in combination with greater narcissism, aggression, and markedly higher conduct problems, whereas lower anxious primary variants showed higher self-esteem. Secondary callous-unemotional variants also reported greater susceptibility to peer pressure and popularity striving than primary variants. Both variants exhibited poorer outcomes relative to low risk and anxious youth, although anxious youth reported lower self-esteem and higher impulsivity and reactive aggression scores in comparison with low risk youth. Findings integrate two lines of inquiry focused on subtyping children and adults with psychopathic traits and antisocial behaviors. They also support the utility of subtyping callous-unemotional traits based on conduct problems and anxiety levels and provide information on common and distinct risk factors associated with primary and secondary callous-unemotional variants in a community sample of adolescent boys and girls. PMID:23644815

Fanti, Kostas A; Demetriou, Chara A; Kimonis, Eva R

2013-07-01

109

Prosocial Involvement and Antisocial Peer Affiliations as Predictors of Behavior Problems in Urban Adolescents: Main Effects and Moderating Effects  

ERIC Educational Resources Information Center

This study examined the relationships between prosocial involvement (PI), antisocial peer affiliations (APA), and the degree of their overlapping or independent prediction of behavior problems in urban adolescents. Two dimensions of behavior were assessed at ages 9-11 and at ages 13-15: disruptive, aggressive conduct and number of delinquent…

Kaufmann, Dagmar R.; Wyman, Peter A.; Forbes-Jones, Emma L.; Barry, Jason

2007-01-01

110

Social Competency Training Goes to School: Pupil Involvement in the Classroom through Problem-Solving with People.  

ERIC Educational Resources Information Center

The need for a "systems" approach to school-based social competency training has been highlighted by a national commission and the U.S. Department of Education. The Pupil Involvement/Problem-Solving with People (PI/PSP) curriculum has adapted numerous, well-researched social compentency training models targeted for elementary classroom use.…

Hallarman, Prudence R.; And Others

111

Increasing Involvement of Elementary School Teachers in Problem-Solving, Vertical Communication, and Policy Development by Implementing Quality Circles.  

ERIC Educational Resources Information Center

The implementation of quality circles to increase elementary school teachers' involvement in problem solving, vertical communication, and policy formation is examined in this practicum report. An attitudinal survey of 44 elementary teachers to document lack of vertical communication yielded 32 responses. A followup survey was administered to the…

Thomas, Grace Gilliard

112

A taxometric analysis of problem gambling data from a South African national urban sample.  

PubMed

We investigate the question whether problem gambling (PG) in a recent South African sample, as measured by the Problem Gambling Severity Index (PGSI), is dimensional or categorical. We use two taxometric procedures, Mean Above Minus Below A Cut (MAMBAC) and Maxim Covariance (MAXCOV), to investigate the taxonic structure of PG as constructed by the PGSI. Data are from the 2010 South African National Urban Prevalence Study of Gambling Behavior. A representative sample of the urban adult population in South Africa (N = 3,000). Responses are to the 9 item PGSI. MAMBAC provided positive but modest evidence that PG as measured by the PGSI was taxonic. MAXCOV pointed more strongly to the same conclusion. These analyses also provide evidence that a PGSI cutoff score of 10 rather than the standard 8 may be called for. PG as constructed by the PGSI may best be thought of as categorical, but further studies with more theory based measurements are needed to determine whether this holds in a wider range of samples and for other screens. A higher cutoff score may be called for on the PGSI when it is used for research purposes to avoid false positives. PMID:22711182

Kincaid, Harold; Daniels, Reza; Dellis, Andrew; Hofmeyr, Andre; Rousseau, Jacques; Sharp, Carla; Ross, Don

2013-09-01

113

[Problems in sampling the polycyclic aromatic hydrocarbons and air-dispersed particles].  

PubMed

Polynuclear aromatic hydrocarbons (PAH) are difficult to monitor and quantify. This study has been worked-out to evaluate various sampling methods for monitoring PAH in the work environment: the sampling devices were tested on the field in a carbon electrodes factory. During the field surveys we used the following sampling procedures that actually are the most adopted: Glass fiber filter, Silver membrane (Teflon, cellulosic esters), The over mentioned membrane filters followed by solid substrate (Amberlite XAD-2). For the analytical quantification we followed this procedure: PAH s extraction from membranes and resins by solvent in ultrasonic bath; quantification by GS-MS (single ion monitor, capillary column, on column injection). Results of field testing show that for completely retain PAHs during air sampling in work environment it is necessary to use a membrane filter followed by a back-up tube of Amberlite-XAD-2 resin: the use of this sampling device is particularly recommended during monitoring of work operations with temperature greater than or equal to 150 degrees C involving coke oven procedure, charcoal production, asphalt production, petroleum coking operations. PMID:6545210

Pozzoli, L; Cottica, D

1984-01-01

114

The inverse problem in magnetic force microscopy—inferring sample magnetization from MFM images  

NASA Astrophysics Data System (ADS)

Nanomagnetic structures have the potential to surpass silicon’s scaling limitations both as elements in hybrid CMOS logic and as novel computational elements. Magnetic force microscopy (MFM) offers a convenient characterization technique for use in the design of such nanomagnetic structures. MFM measures the magnetic field and not the sample’s magnetization. As such the question of the uniqueness of the relationship between an external magnetic field and a magnetization distribution is a relevant one. To study this problem we present a simple algorithm which searches for magnetization distributions consistent with an external magnetic field and solutions to the micromagnetic equations’ qualitative features. The algorithm is not computationally intensive and is found to be effective for our test cases. On the basis of our results we propose a systematic approach for interpreting MFM measurements.

Rawlings, Colin; Durkan, Colm

2013-08-01

115

Infinitely many solutions for an elliptic Neumann problem involving critical Sobolev growth  

NASA Astrophysics Data System (ADS)

In this paper, we prove the existence of infinitely many solutions for the following elliptic problem with critical Sobolev growth: -?u=|-2u+g(u) in ?, {?u}/{??}=0 on ??, where ? is a bounded domain in R with C boundary, N?3, ? is the outward unit normal of ? ?, 2=2N/N-2, and g(t)=?|t-t, or g(t)=?t, where p?(2,2), ?>0 are constants. We obtain the existence of infinitely many solutions under certain assumptions on N, p and ? ?. In particular, if g(t)=?t with ?>0, N?7, and ? is a strictly convex domain, then the problem has infinitely many solutions.

Cao, Daomin; Yan, Shusen

116

An Alternative Numerical Method for Initial Value Problems Involving the Contact Nonlinear Hamiltonians  

Microsoft Academic Search

We suggest a new difference scheme for dealing with contact nonlinear Hamiltonians. The scheme has two parts. First, the system is transformed to the interaction picture of quantum mechanics using the time-independent Hamiltonian H0. This reduces the problem to a system of ordinary differential equations in time. Subsequently, the system is integrated in time for a time step ?t and

Marijan Kostrun; Juha Javanainen

2001-01-01

117

A Minimax Facility Layout Problem Involving Distances Within and Between Facilities.  

National Technical Information Service (NTIS)

This paper presents a simple solution procedure for the problem of laying out n facilities, where each facility takes up a planar region of known area but with shape not prespecified, so as to minimize the maximum of the following terms: the greatest of t...

R. L. Francis J. J. Bartholdi R. L. Papineau

1975-01-01

118

A Minimax Facility Layout Problem Involving Distances between and within Facilities.  

National Technical Information Service (NTIS)

This paper presents a simple solution procedure for the problem of laying out n facilities, where each facility takes up a planar region of known area but with shape not prespecified, so as to minimize the maximum of the following terms: the greatest of t...

R. L. Papineau R. L. Francis J. J. Bartholdi

1974-01-01

119

Some Problems Involved in the Shared Cataloging Subsystem of the Ohio College Library Center.  

ERIC Educational Resources Information Center

This report outlines the development of the Ohio College Library Center (OCLC) and considers some basic problems in OCLC shared cataloging--e.g., the uneven quality of input cataloging and increasing number of duplicate records. Summaries of findings from an OCLC evaluative study and two surveys of shared cataloging are presented. The report…

Sacco, Margaret T.

120

Interval-Valued Optimization Problems Involving (?, ?)-Right Upper-Dini-Derivative Functions  

PubMed Central

We consider an interval-valued multiobjective problem. Some necessary and sufficient optimality conditions for weak efficient solutions are established under new generalized convexities with the tool-right upper-Dini-derivative, which is an extension of directional derivative. Also some duality results are proved for Wolfe and Mond-Weir duals.

2014-01-01

121

A lower bound in an approximation problem involving the zeros of the Riemann zeta function  

Microsoft Academic Search

We slightly improve the lower bound of Baez-Duarte, Balazard, Landreau and Saias in the Nyman-Beurling formulation of the Riemann Hypothesis as an approximation problem. We construct Hilbert space vectors which could prove useful in the context of the so-called `Hilbert-Polya idea'.

Jean-Francois Burnol

2001-01-01

122

A Lower Bound in an Approximation Problem Involving the Zeros of the Riemann Zeta Function  

Microsoft Academic Search

We slightly improve the lower bound of Báez-Duarte, Balazard, Landreau and Saias in the Nyman–Beurling formulation of the Riemann Hypothesis as an approximation problem. We construct Hilbert space vectors which could prove useful in the context of the so-called “Hilbert–Pólya idea”.

Jean-François Burnol

2002-01-01

123

High-Order Integral Equation Methods for Diffraction Problems Involving Screens and Apertures  

NASA Astrophysics Data System (ADS)

This thesis presents a novel approach for the numerical solution of problems of diffraction by infinitely thin screens and apertures. The new methodology relies on combination of weighted versions of the classical operators associated with the Dirichlet and Neumann open-surface problems. In the two-dimensional case, a rigorous proof is presented, establishing that the new weighted formulations give rise to second-kind Fredholm integral equations, thus providing a generalization to open surfaces of the classical closed-surface Calderon formulae. High-order quadrature rules are introduced for the new weighted operators, both in the two-dimensional case as well as the scalar three-dimensional case. Used in conjunction with Krylov subspace iterative methods, these rules give rise to efficient and accurate numerical solvers which produce highly accurate solutions in small numbers of iterations, and whose performance is comparable to that arising from efficient high-order integral solvers recently introduced for closed-surface problems. Numerical results are presented for a wide range of frequencies and a variety of geometries in two- and three-dimensional space, including complex resonating structures as well as, for the first time, accurate numerical solutions of classical diffraction problems considered by the 19th-century pioneers: diffraction of high-frequency waves by the infinitely thin disc, the circular aperture, and the two-hole geometry inherent in Young's experiment.

Lintner, Stephane K.

124

Smith and Jones: Children's thinking about some problems involving displacement along the number?line  

Microsoft Academic Search

Displacements along a number?line are often used as a model for teaching operations with integers in school mathematics [1]. The author has already postulated in a previous article [2] that such an approach must involve formal operations, in Piaget's terms, when it comes to subtraction of negative integers and must therefore cause difficulty with children in the early stages of

Mary J. Galbraith

1975-01-01

125

Sample Size Calculations for Population Pharmacodynamic Experiments Involving Repeated Dichotomous Observations  

Microsoft Academic Search

Analysis of repeated binary measurements presents a challenge in terms of the correlation between measurements within an individual and a mixed-effects modelling approach has been used for the analysis of such data. Sample size calculation is an important part of clinical trial design and it is often based on the method of analysis. We present a method for calculating the

Kayode Ogungbenro; Leon Aarons

2008-01-01

126

The importance of problem formulations in risk assessment: a case study involving dioxin-contaminated soil.  

PubMed

The need to remediate contaminated soils is typically accomplished by applying standard risk assessment methods followed by risk management to select remedial options. These human health risk assessments (HHRAs) have been largely conducted in a formulaic manner that relies heavily on standard deterministic exposure, toxicity assumptions and fixed mathematical formulas. The HHRA approach, with its traditional formulaic practice, does not take advantage of problem formulation in the same manner as is done in ecological risk assessment, and historically, has generally failed to emphasize incorporation of site-specific information. In response to these challenges, the National Academy of Sciences recently made several recommendations regarding the conduct of HHRAs, one of which was to begin all such assessments with problem formulation. These recommendations have since been extended to dose response assessment. In accordance with these recommendations, a group of experts presented and discussed findings that highlighted the importance and impact of including problem formulation when determining the need for remediation of dioxin contamination in soils, focusing in particular on exposure assessment is described. PMID:23545073

Dourson, Michael L; Gadagbui, Bernard; Griffin, Susan; Garabrant, David H; Haws, Laurie C; Kirman, Christopher; Tohyama, Chiharu

2013-07-01

127

A new approach to the solution of boundary value problems involving complex configurations  

NASA Technical Reports Server (NTRS)

A new approach for solving certain types of boundary value problems about complex configurations is presented. Numerical algorithms from such diverse fields as finite elements, preconditioned Krylov subspace methods, discrete Fourier analysis, and integral equations are combined to take advantage of the memory, speed and architecture of current and emerging supercomputers. Although the approach has application to many branches of computational physics, the present effort is concentrated in areas of Computational Fluid Dynamics (CFD) such as steady nonlinear aerodynamics, time harmonic unsteady aerodynamics, and aeroacoustics. The most significant attribute of the approach is that it can handle truly arbitrary boundary geometries and eliminates the difficult task of generating surface fitted grids.

Rubbert, P. E.; Bussoletti, J. E.; Johnson, F. T.; Sidwell, K. W.; Rowe, W. S.; Samant, S. S.; Sengupta, G.; Weatherill, W. H.; Burkhart, R. H.; Woo, A. C.

1986-01-01

128

The Relationship Between Reported Health and Involvement in Bully\\/Victim Problems among Male and Female Secondary Schoolchildren  

Microsoft Academic Search

The relationship between involvement in bully\\/victim problems at school and the reported health of adolescents was investigated using questionnaires completed anonymously by 819 Australian schoolchildren attending coeducational high school. From self-reports of their relations with peers at school, respondents were categorized as victims, bullies, bully-victims and ‘others’. The students also completed a measure of mental health, the General Health Questionnaire,

Ken Rigby

1998-01-01

129

Longitudinal Associations of Alcohol Involvement with Subjective Well-Being in Adolescence and Prediction to Alcohol Problems in Early Adulthood  

Microsoft Academic Search

Adolescent alcohol involvement is associated with numerous negative outcomes, but also appears to have positive correlates,\\u000a including subjective well-being. Additional research is needed to understand these paradoxical findings. The current study\\u000a examines alcohol use, adverse alcohol-related (and other substance-related) consequences, and subjective well being in adolescence,\\u000a and prediction to problem alcohol use in early adulthood. Participants in this longitudinal study,

W. Alex MasonRichard; Richard L. Spoth

130

Psychometric Analyses of the Problem-Focused Style of Coping (PF-SOC) Scale with Taiwanese Samples  

ERIC Educational Resources Information Center

The current research comprises two samples that investigated the psychometric properties of the Problem-Focused Style of Coping (PF-SOC; Heppner, Cook, Wright, & Johnson) scale using two Taiwanese samples. In Sample 1 (N = 809), we investigated the structural dimensions of the PF-SOC using a principal component analysis (PCA) and confirmed three…

Chang, Yuhsuan; Lan, Yu-Ling; Lin, Hung-Yu; Heppner, Puncky Paul

2012-01-01

131

Helmholtz Fermi surface harmonics: an efficient approach for treating anisotropic problems involving Fermi surface integrals  

NASA Astrophysics Data System (ADS)

We present a new efficient numerical approach for representing anisotropic physical quantities and/or matrix elements defined on the Fermi surface (FS) of metallic materials. The method introduces a set of numerically calculated generalized orthonormal functions which are the solutions of the Helmholtz equation defined on the FS. Noteworthy, many properties of our proposed basis set are also shared by the FS harmonics introduced by Philip B Allen (1976 Phys. Rev. B 13 1416), proposed to be constructed as polynomials of the cartesian components of the electronic velocity. The main motivation of both approaches is identical, to handle anisotropic problems efficiently. However, in our approach the basis set is defined as the eigenfunctions of a differential operator and several desirable properties are introduced by construction. The method is demonstrated to be very robust in handling problems with any crystal structure or topology of the FS, and the periodicity of the reciprocal space is treated as a boundary condition for our Helmholtz equation. We illustrate the method by analysing the free-electron-like lithium (Li), sodium (Na), copper (Cu), lead (Pb), tungsten (W) and magnesium diboride (MgB_{2}).

Eiguren, Asier; Gurtubay, Idoia G.

2014-06-01

132

Synthesis of Wavelet Theory and the Multigrid Approach: Numerical Solution of Problems Involving Long-Range Interactions  

NASA Astrophysics Data System (ADS)

Multigrid algorithms represent the state of the art in the numerical solution of physical problems involving long-range interactions, such as finding the potential due to a charge distribution. Wavelets provide an efficient representation of functions which exhibit localized bursts of short length-scale behavior, such as the total electronic charge density of a molecule. Computing the electrostatic field in and around a molecule should benefit from both approaches. In this work, we demonstrate how a novel interpolating wavelet transform may be used as the mathematical bridge to connect the two approaches. The result is a specialized multigrid algorithm which may be applied to problems expressed in wavelet bases. With this approach, optimal interpolation and restriction operators and optimal grids are predetermined by an interpolating multiresolution analysis. Moreover, problems on irregular meshes may be treated efficiently without invoking a dense underlying regular mesh. We will present the new method and contrast its efficiency with standard wavelet and multigrid approaches.

Yesilleten, Dicle; Arias, Tomás

1996-03-01

133

Synthesis of Wavelet Theory and the Multigrid Approach: Numerical Solution of Problems Involving Long-Range Interactions  

NASA Astrophysics Data System (ADS)

Multigrid algorithms represent the state of the art in the numerical solution of physical problems involving long-range interactions, such as finding the potential due to a charge distribution. Wavelets provide an efficient representation of functions which exhibit localized bursts of short length-scale behavior, such as the total electronic charge density of a molecule. Computing the electrostatic field in and around a molecule should benefit from both approaches. In this work, we demonstrate how a novel interpolating wavelet transform may be used as the mathematical bridge to connect the two approaches. The result is a specialized multigrid algorithm which may be applied to problems expressed in wavelet bases. With this approach, optimal interpolation and restriction operators and optimal grids are predetermined by an interpolating multiresolution analysis. Moreover, problems on irregular meshes may be treated efficiently without invoking a dense underlying regular mesh. We will present the new method and contrast its efficiency with standard wavelet and multigrid.

Yeþýlleten, Dicle; Arias, Tomas

1997-01-01

134

Sampling  

NSDL National Science Digital Library

This tutorial covers some of the key terms in sampling like "population" and "sampling frame," some of the statistical terms used in sampling, and the major distinction between probability and Nonprobability sampling methods.

William Trochim (Cornell University)

2006-10-20

135

Adolescent criminal justice involvement and adulthood sexually transmitted infection in a nationally representative US sample.  

PubMed

Criminal justice involvement (CJI) disrupts social and sexual networks, and sexually transmitted infections (STIs) thrive on network disruption. Adolescent CJI may be a particularly important determinant of STI because experiences during adolescence influence risk trajectories into adulthood. We used Wave III (2001-2002: young adulthood) of the National Longitudinal Study of Adolescent Health (N?=?14,322) to estimate associations between history of adolescent (younger than 18 years) CJI and adult STI risk. Respondents who reported a history of repeat arrest in adolescence, adolescent conviction, and arrest both as an adolescent and an adult (persistent arrest) had between two to seven times the odds of STI (biologically confirmed infection with chlamydia, gonorrhea, or trichomoniasis) in adulthood and between two to three times the odds of multiple partnerships and inconsistent condom use in the past year in adulthood. In analyses adjusting for sociodemographic and behavioral factors, history of having six or more adolescent arrests was associated with more than five times the odds of STI (adjusted odds ratio (AOR) 5.44, 95 % confidence interval (CI) 1.74-17.1). Both adolescent conviction and persistent CJI appeared to remain independent correlates of STI (conviction: AOR 1.90, 95 % CI 1.02-3.55; persistent CJI: AOR 1.60, 95 % CI 0.99-2.57). Adolescents who have repeat arrests, juvenile convictions, and persist as offenders into adulthood constitute priority populations for STI treatment and prevention. The disruptive effect of adolescent CJI may contribute to a trajectory associated with STI in adulthood. PMID:22815054

Khan, Maria R; Rosen, David L; Epperson, Matthew W; Goldweber, Asha; Hemberg, Jordana L; Richardson, Joseph; Dyer, Typhanye Penniman

2013-08-01

136

Service use after court involvement in a sample of serious adolescent offenders  

PubMed Central

The juvenile justice system faces a difficult challenge when providing services to serious adolescent offenders, having to balance community safety concerns with hopes for successful intervention. Increasing the effectiveness of this system rests partially on having a clearer picture of the regularities of current service provision to these adolescents. This study describes the types of services received by a large (N=868) sample of adjudicated serious offenders from two metropolitan areas over a two-year follow-up period after adjudication in court, and examines whether indicators of need for services determine the types of services received in the juvenile justice system. Findings indicate that: 1) the level of specialized services received is rather low, 2) there is considerable site variability, 3) the service needs of adolescents sent to different types of settings appear to be generally equivalent, 4) state training schools appear to provide about the same level of services found in contracted provider settings, and 5) need is an inconsistent determinant of service provision.

Mulvey, Edward P.; Schubert, Carol A.; Chung, He Len

2009-01-01

137

Eating Problems and Their Risk Factors: A 7-Year Longitudinal Study of a Population Sample of Norwegian Adolescent Girls  

ERIC Educational Resources Information Center

The longitudinal stability of eating problems and their relationships to risk factors were investigated in a representative population sample of 623 Norwegian girls aged 13-14 followed over 7 years (3 time points). Three eating problem symptoms were measured: Restriction, Bulimia-food preoccupation, and Diet, all taken from the 12-item Eating…

Kansi, Juliska; Wichstrom, Lars; Bergman, Lars R.

2005-01-01

138

Substance use behaviors, mental health problems, and use of mental health services in a probability sample of college students  

Microsoft Academic Search

This research examined 1) the prevalence of substance use behaviors in college students, 2) gender and academic level as moderators of the associations between mental health problems and substance use, and 3) mental health service use among those with co-occurring frequent binge drinking and mental health problems. As part of the Healthy Minds Study, a probability sample of 2843 college

James A. Cranford; Daniel Eisenberg; Alisha M. Serras

2009-01-01

139

Levels and types of alcohol biomarkers in DUI and clinic samples for estimating workplace alcohol problems.  

PubMed

Widespread concern about illicit drugs as an aspect of workplace performance potentially diminishes attention on employee alcohol use. Alcohol is the dominant drug contributing to poor job performance; it also accounts for a third of the worldwide public health burden. Evidence from public roadways--a workplace for many--provides an example of work-related risk exposure and performance lapses. In most developed countries, alcohol is involved in 20-35% of fatal crashes; drugs other than alcohol are less prominently involved in fatalities. Alcohol biomarkers can improve detection by extending the timeframe for estimating problematic exposure levels and thereby provide better information for managers. But what levels and which markers are right for the workplace? In this paper, an established high-sensitivity proxy for alcohol-driving risk proclivity is used: an average eight months of failed blood alcohol concentration (BAC) breath tests from alcohol ignition interlock devices. Higher BAC test fail rates are known to presage higher rates of future impaired-driving convictions (driving under the influence; DUI). Drivers in alcohol interlock programmes log 5-7 daily BAC tests; in 12 months, this yields thousands of samples. Also, higher programme entry levels of alcohol biomarkers predict a higher likelihood of failed interlock BAC tests during subsequent months. This paper summarizes the potential of selected biomarkers for workplace screening. Markers include phosphatidylethanol (PEth), percent carbohydrate deficient transferrin (%CDT), gammaglutamyltransferase (GGT), gamma %CDT (?%CDT), and ethylglucuronide (EtG) in hair. Clinical cut-off levels and median/mean levels of these markers in abstinent people, the general population, DUI drivers, and rehabilitation clinics are summarized for context. PMID:22311827

Marques, Paul R

2012-02-01

140

Accuracy Study of the Space-Time CE/SE Method for Computational Aeroacoustics Problems Involving Shock Waves  

NASA Technical Reports Server (NTRS)

The space-time conservation element and solution element(CE/SE) method is used to study the sound-shock interaction problem. The order of accuracy of numerical schemes is investigated. The linear model problem.govemed by the 1-D scalar convection equation, sound-shock interaction problem governed by the 1-D Euler equations, and the 1-D shock-tube problem which involves moving shock waves and contact surfaces are solved to investigate the order of accuracy of numerical schemes. It is concluded that the accuracy of the CE/SE numerical scheme with designed 2nd-order accuracy becomes 1st order when a moving shock wave exists. However, the absolute error in the CE/SE solution downstream of the shock wave is on the same order as that obtained using a fourth-order accurate essentially nonoscillatory (ENO) scheme. No special techniques are used for either high-frequency low-amplitude waves or shock waves.

Wang, Xiao Yen; Chang, Sin-Chung; Jorgenson, Philip C. E.

1999-01-01

141

On Sample Size Determination.  

National Technical Information Service (NTIS)

A frequent request made prior to sampling involves the determination of the appropriate sample size necessary to estimate population characteristics (for example, the arithmetic mean) within a specified accuracy. Although the problem can be simply stated,...

1964-01-01

142

Sampling solution traces for the problem of sorting permutations by signed reversals  

PubMed Central

Background Traditional algorithms to solve the problem of sorting by signed reversals output just one optimal solution while the space of all optimal solutions can be huge. A so-called trace represents a group of solutions which share the same set of reversals that must be applied to sort the original permutation following a partial ordering. By using traces, we therefore can represent the set of optimal solutions in a more compact way. Algorithms for enumerating the complete set of traces of solutions were developed. However, due to their exponential complexity, their practical use is limited to small permutations. A partial enumeration of traces is a sampling of the complete set of traces and can be an alternative for the study of distinct evolutionary scenarios of big permutations. Ideally, the sampling should be done uniformly from the space of all optimal solutions. This is however conjectured to be ?P-complete. Results We propose and evaluate three algorithms for producing a sampling of the complete set of traces that instead can be shown in practice to preserve some of the characteristics of the space of all solutions. The first algorithm (RA) performs the construction of traces through a random selection of reversals on the list of optimal 1-sequences. The second algorithm (DFALT) consists in a slight modification of an algorithm that performs the complete enumeration of traces. Finally, the third algorithm (SWA) is based on a sliding window strategy to improve the enumeration of traces. All proposed algorithms were able to enumerate traces for permutations with up to 200 elements. Conclusions We analysed the distribution of the enumerated traces with respect to their height and average reversal length. Various works indicate that the reversal length can be an important aspect in genome rearrangements. The algorithms RA and SWA show a tendency to lose traces with high average reversal length. Such traces are however rare, and qualitatively our results show that, for testable-sized permutations, the algorithms DFALT and SWA produce distributions which approximate the reversal length distributions observed with a complete enumeration of the set of traces.

2012-01-01

143

Negative Peer Involvement in Multisystemic Therapy for the Treatment of Youth Problem Behavior: Exploring Outcome and Process Variables in "Real-World" Practice  

ERIC Educational Resources Information Center

Associating with a negative peer group is related to involvement in problem behavior, yet very little research has considered the role of negative peer group affiliations in the context of "real-world" community-based treatments for problem behavior. This study examined the effects of negative peer involvement on case closure status and treatment…

Boxer, Paul

2011-01-01

144

Quantification and molecular characterization of Salmonella isolated from food samples involved in salmonellosis outbreaks in Rio Grande do Sul, Brazil  

PubMed Central

Data concerning the prevalence and populations of Salmonella in foods implicated in outbreaks may be important to the development of quantitative microbial risk assessments of individual food products. In this sense, the objective of the present study was to assess the amount of Salmonella sp. in different foods implicated in foodborne outbreaks in Rio Grande do Sul occurred in 2005 and to characterize the isolated strains using phenotypic and genotypic methods. Nineteen food samples involved in ten foodborne outbreaks occurred in 2005, and positive on Salmonella isolation at the Central Laboratory of the Health Department of the State of Rio Grande do Sul, were included in this study. Food samples were submitted to estimation of Salmonella using the Most Probable Number (MPN) technique. Moreover, one confirmed Salmonella colony of each food sample was serotyped, characterized by its XbaI-macrorestriction profile, and submitted to antimicrobial resistance testing. Foods containing eggs, mayonnaise or chicken were contaminated with Salmonella in eight outbreaks. Higher counts (>107 MPN.g-1) of Salmonella were detected mostly in foods containing mayonnaise. The isolation of Salmonella from multiple food items in five outbreaks probably resulted from the cross-contamination, and the high Salmonella counts detected in almost all analyzed samples probably resulted from storing in inadequate temperature. All strains were identified as S. Enteritidis, and presented a unique macrorestriction profile, demonstrating the predominance of one clonal group in foods involved in the salmonellosis outbreaks. A low frequency of antimicrobial resistant S. Enteritidis strains was observed and nalidixic acid was the only resistance marker detected.

Murmann, Lisandra; dos Santos, Maria Cecilia; Longaray, Solange Mendes; Both, Jane Mari Correa; Cardoso, Marisa

2008-01-01

145

The Problem of Sample Contamination in a Fluvial Geochemistry Research Experience for Undergraduates.  

ERIC Educational Resources Information Center

Introduces the analysis of a river as an excellent way to teach geochemical techniques because of the relative ease of sample collection and speed of sample analysis. Focuses on the potential sources of sample contamination during sampling, filtering, and bottle cleaning processes, and reviews methods to reduce and detect contamination. Includes…

Andersen, Charles B.

2001-01-01

146

The role of grandparents in preventing aggressive and other externalizing behavior problems in children from rural, methamphetamine-involved families  

PubMed Central

Preventive interventions are urgently needed for children from rural, methamphetamine-involved families, who are at risk for the development of aggressive and other externalizing behavioral problems. This mixed method study explored naturally occurring sources of protection and considers the implications for targeted interventions. Participants were 41 children aged six to 14 years from rural families involved with methamphetamine and the public child welfare system, their primary caregivers, and 19 parents recovering from methamphetamine addiction. When invited during semi-structured interviews to talk about their families, 48% of children spontaneously described socially and emotionally supportive relationships with healthy grandparents. Children’s reports of support from grandparents were associated with lower scores on CBCL Social Problems, [t(37)= 2.23, p<.05 ]; externalizing behaviors, [t(37)= 2.07, p<.05]; and aggressive behaviors, [t(37)= 2.75, p<.01]. When asked to talk about their families, 58% of parents spontaneously described the support their children received from grandparents, and 26% also described the support that they had received from their own grandparents. Children’s and parents’ descriptions of grandparent support suggest how grandparents may protect children from the development of aggressive and other externalizing behavior problems. First, grandparents may prevent obstacles to healthy development by providing their grandchildren with safe shelter and basic child care when parents are incapacitated from substance misuse. Second, they may promote their grandchildren’s positive social-emotional development through supportive relationships. Third, they may promote social competence through enjoyable leisure activities with healthy adults and non-delinquent peers. Understanding naturally occurring sources of protection for children can inform the development of interventions by identifying strengths on which to build, and suggesting culturally sensitive approaches when children are struggling.

Sheridan, Kathryn; Haight, Wendy L.; Cleeland, Leah

2011-01-01

147

Analysis of Korean High School Students' Decision-Making Processes in Solving a Problem Involving Biological Knowledge  

NASA Astrophysics Data System (ADS)

In this study, the cognitive characteristics of students'' decision-making processes centered on phases, difficulties, and strategies are analysed in the personal dailylife context involving biological knowledge. The subjects were first year science and general high school students in Seoul, Korea; 6 female students and 7 male students. The students'' decision-making processes were analysed by think-aloud and participant observation methods. On the whole, the students'' decision-making processes progressed in following order: recognizing a problem, searching for alternatives, evaluating the alternatives, and decision. During the decision-making processes, the above phases were repeated by trial and error. Students preferred noncompensatory rules that did not allow trade offs among alternatives for decisions, rather than compensatory rules of selection. Students had a tendency to have difficulties in analysing the difference between initial state and desirable state of the problem, organising biological knowledge-related problems, and clarifying values as selective criteria. Even students who had high achievement and more positive science-related attitudes did not apply biological knowledge to search for alternatives, and could not utilise scientific values as selective criteria very well. We discuss the implications of these results for teaching of decision-making in respect to scientific literacy.

Hong, Jung-Lim; Chang, Nam-Kee

2004-02-01

148

Screening for alcohol problems in two emergency service samples in Poland: comparison of the RAPS4, CAGE and AUDIT.  

PubMed

Prior research on alcohol-related problems among emergency service patients in Poland found substantial alcohol involvement on the part of injured males, suggesting emergency services may be a productive venue for identifying patients who could benefit from a brief intervention or referral for treatment. Performance of the RAPS4, CAGE and AUDIT against ICD-10 and DSM-IV criteria for alcohol dependence and for alcohol abuse/harmful drinking was compared in probability samples of emergency service patients from two regions of Poland. Sensitivity of the RAPS4 and AUDIT was significantly better than the CAGE for alcohol dependence among males in Warsaw, but specificity was poorer. Among females, although numbers were small, sensitivity for alcohol abuse/harmful drinking and for alcohol dependence or abuse/harmful drinking was significantly better for the RAPS4-QF than for the CAGE or AUDIT at a cut point of 8 across both sites. Performance of the AUDIT at a cut point of 3 was similar to the RAPS4-QF for females. Among males, sensitivity was higher but specificity considerably lower for the RAPS4-QF compared to the CAGE at a cut point of 1 or for the AUDIT at a cut point of 8. Alternate cut points for the AUDIT optimized performance. Findings suggest some regional and gender differences in performance of screening instruments in these Polish samples, but no instrument or cut point is optimal in identifying those with alcohol use disorders. Additional cross-cultural research is needed to evaluate the performance of instruments, especially among females with alcohol use disorders. PMID:15896929

Cherpitel, Cheryl J; Ye, Yu; Moskalewicz, Jacek; Swiatkiewicz, Grazyna

2005-11-01

149

Alcoholics Anonymous attendance following 12-step treatment participation as a link between alcohol-dependent fathers' treatment involvement and their children's externalizing problems  

Microsoft Academic Search

We investigated longitudinal associations between alcohol-dependent fathers' 12-step treatment involvement and their children's internalizing and externalizing problems (N = 125, Mage = 9.8 ± 3.1), testing the hypotheses that fathers' greater treatment involvement would benefit later child behavior and that this effect would be mediated by fathers' posttreatment behaviors. The initial association was established between fathers' treatment involvement and children's

Jasmina Burdzovic Andreas; Timothy J. O'Farrell

2009-01-01

150

A HUPO test sample study reveals common problems in mass spectrometry–based proteomics  

Microsoft Academic Search

We performed a test sample study to try to identify errors leading to irreproducibility, including incompleteness of peptide sampling, in liquid chromatography–mass spectrometry–based proteomics. We distributed an equimolar test sample, comprising 20 highly purified recombinant human proteins, to 27 laboratories. Each protein contained one or more unique tryptic peptides of 1,250 Da to test for ion selection and sampling in

Alexander W Bell; Eric W Deutsch; Catherine E Au; Robert E Kearney; Ron Beavis; Salvatore Sechi; Tommy Nilsson; Thomas A Beardslee; Thomas Chappell; Gavin Meredith; Peter Sheffield; Phillip Gray; Mahbod Hajivandi; Marshall Pope; Paul Predki; Majlinda Kullolli; Marina Hincapie; William S Hancock; Wei Jia; Lina Song; Lei Li; Junying Wei; Bing Yang; Jinglan Wang; Wantao Ying; Yangjun Zhang; Yun Cai; Xiaohong Qian; Fuchu He; Helmut E Meyer; Christian Stephan; Martin Eisenacher; Katrin Marcus; Elmar Langenfeld; Caroline May; Steven A Carr; Rushdy Ahmad; Wenhong Zhu; Jeffrey W Smith; Samir M Hanash; Jason J Struthers; Hong Wang; Qing Zhang; Yanming An; Radoslav Goldman; Elisabet Carlsohn; Sjoerd van der Post; Kenneth E Hung; David A Sarracino; Kenneth Parker; Bryan Krastins; Raju Kucherlapati; Sylvie Bourassa; Guy G Poirier; Eugene Kapp; Heather Patsiouras; Robert Moritz; Richard Simpson; Benoit Houle; Sylvie LaBoissiere; Pavel Metalnikov; Vivian Nguyen; Tony Pawson; Catherine C L Wong; Daniel Cociorva; John R Yates III; Michael J Ellison; Ana Lopez-Campistrous; Paul Semchuk; Yueju Wang; Peipei Ping; Giuliano Elia; Michael J Dunn; Kieran Wynne; Angela K Walker; John R Strahler; Philip C Andrews; Brian L Hood; William L Bigbee; Thomas P Conrads; Derek Smith; Christoph H Borchers; Gilles A Lajoie; Sean C Bendall; Kaye D Speicher; David W Speicher; Masanori Fujimoto; Kazuyuki Nakamura; Young-Ki Paik; Sang Yun Cho; Min-Seok Kwon; Hyoung-Joo Lee; Seul-Ki Jeong; An Sung Chung; Christine A Miller; Rudolf Grimm; Katy Williams; Craig Dorschel; Jayson A Falkner; Lennart Martens; Juan Antonio Vizcaíno; John J M Bergeron

2009-01-01

151

Alcoholics Anonymous attendance following 12-step treatment participation as a link between alcohol-dependent fathers' treatment involvement and their children's externalizing problems.  

PubMed

We investigated longitudinal associations between alcohol-dependent fathers' 12-step treatment involvement and their children's internalizing and externalizing problems (N = 125, M(age) = 9.8 +/- 3.1), testing the hypotheses that fathers' greater treatment involvement would benefit later child behavior and that this effect would be mediated by fathers' posttreatment behaviors. The initial association was established between fathers' treatment involvement and children's externalizing problems only, whereas Structural Equation Modeling (SEM) results supported mediating hypotheses. Fathers' greater treatment involvement predicted children's lower externalizing problems 12 months later, and fathers' posttreatment behaviors mediated this association: Greater treatment involvement predicted greater posttreatment Alcoholics Anonymous attendance, which in turn predicted greater abstinence. Finally, fathers' abstinence was associated with lower externalizing problems in children. Theoretical and practical implications of these findings are discussed. PMID:18715745

Andreas, Jasmina Burdzovic; O'Farrell, Timothy J

2009-01-01

152

Alcoholics Anonymous attendance following 12-step treatment participation as a link between alcoholic fathers' treatment involvement and their children's externalizing problems  

PubMed Central

We investigated longitudinal associations between alcoholic fathers’ 12-step treatment involvement and their children’s internalizing and externalizing problems (N=125, Mage=9.8±3.1), testing the hypotheses that fathers’ greater treatment involvement would benefit later child behavior, and that this effect would be mediated by fathers’ post-treatment behaviors. The initial association was established between fathers’ treatment involvement and children’s externalizing problems only, while structural equation (SEM) results supported mediating hypotheses. Fathers’ greater treatment involvement predicted children’s lower externalizing problems 12 months later, and fathers’ post-treatment behaviors mediated this association: greater treatment involvement predicted greater post-treatment Alcoholics Anonymous (AA) attendance, which in turn predicted greater abstinence. Finally, fathers’ abstinence was associated with lower externalizing problems in children. Theoretical and practical implications of these findings are discussed.

Andreas, Jasmina Burdzovic; O'Farrell, Timothy J

2008-01-01

153

Bayesian Analysis of Constrained Parameter and Truncated Data Problems Using Gibbs Sampling  

Microsoft Academic Search

Constrained parameter problems arise in a wide variety of applications, including bioassay, actuarial graduation, ordinal categorical data, response surfaces, reliability development testing, and variance component models. Truncated data problems arise naturally in survival and failure time studies, ordinal data models, and categorical data studies aimed at uncovering underlying continuous distributions. In many applications both parameter constraints and data truncation are

Alan E. Gelfand; Adrian F. M. Smith; Tai-Ming Lee

1992-01-01

154

Sample-size dependence of the ground-state energy in a one-dimensional localization problem  

Microsoft Academic Search

We study the sample-size dependence of the ground-state energy in a one-dimensional localization problem, based on a supersymmetric quantum mechanical Hamiltonian with a random Gaussian potential. We determine, in the form of bounds, the precise form of this dependence and show that the disorder-averaged ground-state energy decreases with an increase of the size R of the sample as a stretched-exponential

C. Monthus; G. Oshanin; A. Comtet; S. F. Burlatsky

1996-01-01

155

Investigation of Problem Solving Ability of Students in School of Physical Education and Sports (Kafkas University Sample)  

ERIC Educational Resources Information Center

The aim of this research is to examine the problem solving abilities of School of Physical Education and Sports students. To achieve this aim, in the academic year 2013-2014, a research group did a study of 433 students of the School of Physical Education and Sports, Kafkas University. This sample consisted of 184 female and 249 male students.…

Ozmutlu, Ilker

2014-01-01

156

Prevalence of behavioral and emotional disturbance and specific problem types in a sample of disadvantaged preschool?aged children  

Microsoft Academic Search

The main goals of this study were to document the prevalence of behavioral and emotional disturbance in a sample of economically disadvantaged preschool?aged children, and to establish base rates of specific problem types through a method of systematic categorization. In conjunction with a large screening project, 462 Head Start children were rated by their teachers on the Preschool Behavior Questionnaire

David R. Anderson

1983-01-01

157

Grid-based Evolutionary Strategies Applied to the ConformationalSampling Problem  

Microsoft Academic Search

Computational simulations of conformational sampling in general, and of macromolecular folding in particular represent one of the most important and yet one of the most challenging applications of computer science in biology and medicinal chemistry. The advent of GRID computing may trigger some major progress in this field. This paper presents our first attempts to design GRID-based conformational sampling strategies,

Benjamin Parent; Alexandru-adrian Tantar; Nouredine Melab; El-ghazali Talbi; Dragos Horvath

2007-01-01

158

Application of the Tripartite Model to a Complicated Sample of Residential Youth with Externalizing Problems  

ERIC Educational Resources Information Center

The tripartite model of anxiety and depression has received strong support among child and adolescent populations. Clinical samples of children and adolescents in these studies, however, have usually been referred for treatment of anxiety and depression. This study investigated the fit of the tripartite model with a complicated sample of…

Chin, Eu Gene; Ebesutani, Chad; Young, John

2013-01-01

159

Importance sampling for quantum Monte Carlo in manifolds: addressing the time scale problem in simulations of molecular aggregates.  

PubMed

Several importance sampling strategies are developed and tested for stereographic projection diffusion Monte Carlo in manifolds. We test a family of one parameter trial wavefunctions for variational Monte Carlo in stereographically projected manifolds which can be used to produce importance sampling. We use the double well potential in one dimensional Euclidean space to study systematically sampling issues for diffusion Monte Carlo. We find that diffusion Monte Carlo with importance sampling in manifolds is orders of magnitude more efficient compared to unguided diffusion Monte Carlo. Additionally, diffusion Monte Carlo with importance sampling in manifolds can overcome problems with nonconfining potentials and can suppress quasiergodicity effectively. We obtain the ground state energy and the wavefunction for the Stokmayer trimer. PMID:18447416

Luan, T; Curotto, E; Mella, Massimo

2008-04-28

160

Does burnout among doctors affect their involvement in patients' mental health problems? A study of videotaped consultations  

PubMed Central

Background General practitioners' (GPs') feelings of burnout or dissatisfaction may affect their patient care negatively, but it is unknown if these negative feelings also affect their mental health care. GPs' available time, together with specific communication tools, are important conditions for providing mental health care. We investigated if GPs who feel burnt out or dissatisfied with the time available for their patients, are less inclined to encourage their patients to disclose their distress, and have shorter consultations, in order to gain time and energy. This may result in less psychological evaluations of patients' complaints. Methods We used 1890 videotaped consultations from a nationally representative sample of 126 Dutch GPs to analyse GPs' communication and the duration of their consultations. Burnout was subdivided into emotional exhaustion, depersonalisation and reduced accomplishment. Multilevel regression analyses were used to investigate which subgroups of GPs differed significantly. Results GPs with feelings of exhaustion or dissatisfaction with the available time have longer consultations compared to GPs without these feelings. Exhausted GPs, and GPs with feelings of depersonalisation, talk more about psychological or social topics in their consultations. GPs with feelings of reduced accomplishment are an exception: they communicate less affectively, are less patient-centred and have less eye contact with their patients compared to GPs without reduced accomplishment. We found no relationship between GPs' feelings of burnout or dissatisfaction with the available time and their psychological evaluations of patients' problems. Conclusion GPs' feelings of burnout or dissatisfaction with the time available for their patients do not obstruct their diagnosis and awareness of patients' psychological problems. On the contrary, GPs with high levels of exhaustion or depersonalisation, and GPs who are dissatisfied with the available time, sometimes provide more opportunities to discuss mental health problems. This increases the chance that appropriate care will be found for patients with mental health problems. On the other hand, these GPs are themselves more likely to retire, or risk burnout, because of their dissatisfaction. Therefore these GPs may benefit from training or personal coaching to decrease the chance that the process of burnout will get out of hand.

Zantinge, Else M; Verhaak, Peter FM; de Bakker, Dinny H; van der Meer, Klaas; Bensing, Jozien M

2009-01-01

161

The effects of witnessing domestic violence on behavioural problems and depressive symptomatology. A community sample of pupils from St Lucia.  

PubMed

Behavioural problems and depressive symptomatology were evaluated in a sample of 60 St Lucian pupils who came from homes where parents were either in violent or non-violent marital relationships. Teachers rated pupils using the Revised Behaviour Problem Checklist (RBPC) while self rating scores were obtained from pupils using either the Reynolds Child Depression Scale (RCDS) or the Reynolds Adolescent Depression Scale (RADS), depending on the age of the pupil. The results indicated that those pupils whose parents were experiencing violent marital discord showed significantly higher levels of both depression and behavioural problems than those pupils not exposed to domestic violence. In addition, exposed children exhibited more behavioural problems but less depressive symptomatology than adolescents. The results from this study are consistent with those of more developed countries. The theoretical implications of these findings are discussed and methodological refinements are suggested for further research. PMID:10639841

Perks, S M; Jameson, M

1999-12-01

162

Residue variability and sampling--practical problems and consequences for residues monitoring.  

PubMed

Data generated in the UK have indicated that pesticide residue levels can be highly variable between the individual fruit or vegetables from the same crop or lot in trade. Statistical experiments with these data showed that residues in composite samples, taken according to Codex recommendations, are unlikely to differ by more than a factor of 3-4 from the mean level in the lot. This was corroborated by results obtained from real composite samples. Many fruit or vegetables in trade are mixed after harvest to form combined lots. Analysis of composite samples provides a good indication of average residues but, where the lot has been mixed, such average values are potentially misleading. Residues monitoring is the best means available for general control of pesticide use and consumer exposure, but new strategies for sampling and analysis are required to address the combined effects of residues variability and mixing of lots. PMID:10983575

Hill, A R

2000-07-01

163

The problem of large samples: An activation analysis study of electronic waste material  

Microsoft Academic Search

Large-volume instrumental photon activation analysis (IPAA) was used for the investigation of shredded electronic waste material.\\u000a Sample masses from 1 to 150 grams were analyzed to obtain an estimate of the minimum sample size to be taken to achieve a\\u000a representativeness of the results which is satisfactory for a defined investigation task. Furthermore, the influence of irradiation\\u000a and measurement parameters

C. Segebade; P. Bode; W. Goerner

2007-01-01

164

Eating Problems at Age 6 Years in a Whole Population Sample of Extremely Preterm Children  

ERIC Educational Resources Information Center

Aim: The aim of this study was to investigate the prevalence of eating problems and their association with neurological and behavioural disabilities and growth among children born extremely preterm (EPC) at age 6 years. Method: A standard questionnaire about eating was completed by parents of 223 children (125 males [56.1%], 98 females [43.9%])…

Samara, Muthanna; Johnson, Samantha; Lamberts, Koen; Marlow, Neil; Wolke, Dieter

2010-01-01

165

Obsessive-Compulsive Disorder and Comorbid Anxiety Problems in a National Anxiety Screening Sample  

Microsoft Academic Search

Questionnaire data were obtained from 5867 participants attending a national anxiety screening program. These participants were selected from more than 15,000 respondents on the basis of never having received treatment for a mental health problem. A screening instrument was designed to assess five anxiety disorders (obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, generalized anxiety disorder, and panic disorder). The present

Lawrence A Welkowitz; Elmer L Struening; John Pittman; Mary Guardino; Joan Welkowitz

2000-01-01

166

Variants of Callous-Unemotional Conduct Problems in a Community Sample of Adolescents  

ERIC Educational Resources Information Center

Callous-unemotional traits are believed to be a childhood precursor to psychopathy, and among youth with conduct problems they designate those showing a particularly severe, stable, and aggressive pattern of antisocial behavior. Youth with callous-unemotional traits are a heterogeneous population and, analogous to adults with psychopathy, research…

Fanti, Kostas A.; Demetriou, Chara A.; Kimonis, Eva R.

2013-01-01

167

Problems of Definition in Sampling Special Populations: The Case of Homeless Persons.  

ERIC Educational Resources Information Center

Problems of definition in estimation in evaluation research were studied through a survey of homeless persons in Cook County (Illinois) based on 481 interviews. Differences arising from the following four population definitions are presented: (1) traditional homeless; (2) marginally housed; (3) social isolates; and (4) total of these categories.…

Johnson, Timothy P.; And Others

1993-01-01

168

Problems with sampling desert tortoises: A simulation analysis based on field data  

USGS Publications Warehouse

The desert tortoise (Gopherus agassizii) was listed as a U.S. threatened species in 1990 based largely on population declines inferred from mark-recapture surveys of 2.59-km2 (1-mi2) plots. Since then, several census methods have been proposed and tested, but all methods still pose logistical or statistical difficulties. We conducted computer simulations using actual tortoise location data from 2 1-mi2 plot surveys in southern California, USA, to identify strengths and weaknesses of current sampling strategies. We considered tortoise population estimates based on these plots as "truth" and then tested various sampling methods based on sampling smaller plots or transect lines passing through the mile squares. Data were analyzed using Schnabel's mark-recapture estimate and program CAPTURE. Experimental subsampling with replacement of the 1-mi2 data using 1-km2 and 0.25-km2 plot boundaries produced data sets of smaller plot sizes, which we compared to estimates from the 1-mi 2 plots. We also tested distance sampling by saturating a 1-mi 2 site with computer simulated transect lines, once again evaluating bias in density estimates. Subsampling estimates from 1-km2 plots did not differ significantly from the estimates derived at 1-mi2. The 0.25-km2 subsamples significantly overestimated population sizes, chiefly because too few recaptures were made. Distance sampling simulations were biased 80% of the time and had high coefficient of variation to density ratios. Furthermore, a prospective power analysis suggested limited ability to detect population declines as high as 50%. We concluded that poor performance and bias of both sampling procedures was driven by insufficient sample size, suggesting that all efforts must be directed to increasing numbers found in order to produce reliable results. Our results suggest that present methods may not be capable of accurately estimating desert tortoise populations.

Freilich, J. E.; Camp, R. J.; Duda, J. J.; Karl, A. E.

2005-01-01

169

The interaction of conduct problems and depressed mood in relation to adolescent substance involvement and peer substance use  

Microsoft Academic Search

Conduct problems are strong positive predictors of substance use and problem substance use among teens, whereas predictive associations of depressed mood with these outcomes are mixed. Conduct problems and depressed mood often co-occur, and such co-occurrence may heighten risk for negative outcomes. Thus, this study examined the interaction of conduct problems and depressed mood at age 11 in relation to

W. Alex Mason; Julia E. Hitchings; Richard L. Spoth

2008-01-01

170

PROBLEMS WITH A NAFION (TRADE NAME) MEMBRANE DRYER FOR DRYING CHROMATOGRAPHIC SAMPLES  

EPA Science Inventory

A Nafion membrane dryer was used to dry samples of organic gases emitted by vegetation before chromatographic separation to reduce water-related retention time variations on a fused-silica column. The dryer caused rearrangement of several monoterpenes and removed several importan...

171

Interrelationships between LGBT-based victimization, suicide, and substance use problems in a diverse sample of sexual and gender minorities.  

PubMed

Research has documented significant relationships between sexual and gender minority stress and higher rates of suicidality (i.e. suicidal ideation and attempts) and substance use problems. We examined the potential mediating role of substance use problems on the relationship between sexual and gender minority stress (i.e. victimization based on lesbian, gay, bisexual, or transgender identity [LGBT]) and suicidality. A nonprobability sample of LGBT patients from a community health center (N = 1457) ranged in age from 19-70 years. Participants reported history of lifetime suicidal ideation and attempts, substance use problems, as well as experiences of LGBT-based verbal and physical attacks. Substance use problems were a significant partial mediator between LGBT-based victimization and suicidal ideation and between LGBT-based victimization and suicide attempts for sexual and gender minorities. Nuanced gender differences revealed that substance use problems did not significantly mediate the relationship between victimization and suicide attempts for sexual minority men. Substance use problems may be one insidious pathway that partially mediates the risk effects of sexual and gender minority stress on suicidality. Substances might be a temporary and deleterious coping resource in response to LGBT-based victimization, which have serious effects on suicidal ideation and behaviors. PMID:23535038

Mereish, Ethan H; O'Cleirigh, Conall; Bradford, Judith B

2014-01-01

172

Calculation of sample problems related to two-phase flow blowdown transients in pressure relief piping of a PWR pressurizer  

SciTech Connect

A method was published, based on the integral method of characteristics, by which the junction and boundary conditions needed in computation of a flow in a piping network can be accurately formulated. The method for the junction and boundary conditions formulation together with the two-step Lax-Wendroff scheme are used in a computer program; the program in turn, is used here in calculating sample problems related to the blowdown transient of a two-phase flow in the piping network downstream of a PWR pressurizer. Independent, nearly exact analytical solutions also are obtained for the sample problems. Comparison of the results obtained by the hybrid numerical technique with the analytical solutions showed generally good agreement. The good numerical accuracy shown by the results of our scheme suggest that the hybrid numerical technique is suitable for both benchmark and design calculations of PWR pressurizer blowdown transients.

Shin, Y.W.; Wiedermann, A.H.

1984-02-01

173

Problems associated with using filtration to define dissolved trace element concentrations in natural water samples  

USGS Publications Warehouse

Field and laboratory experiments indicate that a number of factors associated with filtration other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample) can produce significant variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. The bulk of these variations result from the inclusion/exclusion of colloidally associated trace elements in the filtrate, although dilution and sorption/desorption from filters also may be factors. Thus, dissolved trace element concentrations quantitated by analyzing filtrates generated by processing whole water through similar pore-sized filters may not be equal or comparable. As such, simple filtration of unspecified volumes of natural water through unspecified 0.45-??m membrane filters may no longer represent an acceptable operational definition for a number of dissolved chemical constituents.

Horowitz, A. J.; Lum, K. R.; Garbarino, J. R.; Hall, G. E. M.; Lemieux, C.; Demas, C. R.

1996-01-01

174

The flavor problem of soybean oil. III. A four-sample, glass laboratory deodorizer  

Microsoft Academic Search

Summary  A glass laboratory deodorizer has been described which permits the simultaneous deodorization of four samples under nearly\\u000a identical conditions of time, temperature, pressure and rate of steam flow. The design includes provision for measuring and\\u000a controlling the steam flow, for preventing bumping, for “breaking” the vacuum, and for heating and cooling the deodorizer.\\u000a Successful deodorizations have been made in relatively

Arthur W. Schwab; Herbert J. Dutton

1948-01-01

175

Optimal sampling for estimation with constrained resources using a learning automaton-based solution for the nonlinear fractional knapsack problem  

Microsoft Academic Search

While training and estimation for Pattern Recognition (PR) have been extensively studied, the question of achieving these\\u000a when the resources are both limited and constrained is relatively open. This is the focus of this paper. We consider the problem\\u000a of allocating limited sampling resources in a “real-time” manner, with the explicit purpose of estimating multiple binomial\\u000a proportions (the extension of

Ole-Christoffer Granmo; B. John Oommen

2010-01-01

176

A latent class analysis of underage problem drinking: Evidence from a community sample of 16–20 year olds  

Microsoft Academic Search

The aim of this paper is to shed light on the nature of underage problem drinking by using an empirically based method to characterize the variation in patterns of drinking in a community sample of underage drinkers. A total of 4056 16–20-year-old current drinkers from 212 communities in the US were surveyed by telephone as part of the National Evaluation

Beth A. Reboussin; Eun-Young Song; Anshu Shrestha; Kurt K. Lohman; Mark Wolfson

2006-01-01

177

The relationship between cognitive emotion regulation strategies and emotional problems: comparison between a clinical and a non-clinical sample  

Microsoft Academic Search

This study focuses on the relationship between the use of specific cognitive emotion regulation strategies and emotional problems. Two samples were included: 99 adults from a clinical population and 99 matched non-clinical adults. Data was obtained in both groups on the use of nine cognitive emotion regulation strategies: self-blame, other-blame, rumination, catastrophizing, putting into perspective, positive refocusing, positive reappraisal, acceptance,

Nadia Garnefski; Tessa Van Den Kommer; Vivian Kraaij; Jan Teerds; Jeroen Legerstee; Evert Onstein

2002-01-01

178

Robustness and power of parametric, nonparametric, robustified and adaptive tests—The multi-sample location problem  

Microsoft Academic Search

This paper deals with a survey of different types of tests, parametric, nonparametric, robustified and adaptive ones, and\\u000a with an application to the two-sided c-sample location problem. Some concepts of robustness are discussed, such as breakdown\\u000a point, influence function, gross-error sensitivity and especially ?- and ?-robustness. A robustness study on level ? in the\\u000a case of heteroscedasticity and nonnormal distributions

Herbert Brining

2000-01-01

179

Interpersonal problems across restrictive and binge-purge samples: Data from a community-based eating disorders clinic.  

PubMed

Contemporary models of eating disorders suggest that interpersonal problems contribute to the maintenance of eating disorders. This study examined whether baseline interpersonal problems differed across eating disorder diagnoses and across eating disorder subtypes ("restrictors" vs. "binge-purge" patients) in a large clinical sample. Patients with a primary eating disorder diagnosis (N=406) completed measures of interpersonal problems, eating disorder symptoms, and mood prior to treatment at a specialist eating disorder clinic. Across the sample, more severe eating disorder psychopathology was associated with significantly greater difficulty socializing. Anorexia Nervosa (AN)/restrictor patients reported significantly greater difficulty socializing than Bulimia Nervosa (BN)/binge-purge patients. AN patients reported significantly greater difficulty on a measure of competitiveness/assertiveness compared to BN and Eating Disorder Not Otherwise Specified patients. All findings were significant after controlling for comorbid depression and anxiety symptoms. Interpersonal problems appear to be unique risk factors for eating disorders. Specific interpersonal mechanisms include difficulties socializing and being assertive, which were most pronounced in AN patients. These findings provide potential avenues for enhancing interventions, such as adjunctive assertiveness training for AN. PMID:25064298

Raykos, Bronwyn C; McEvoy, Peter M; Carter, Olivia; Fursland, Anthea; Nathan, Paula

2014-08-01

180

Gender differences in drinking patterns and alcohol-related problems in a community sample in S?o Paulo, Brazil  

PubMed Central

OBJECTIVE: To investigate drinking patterns and gender differences in alcohol-related problems in a Brazilian population, with an emphasis on the frequency of heavy drinking. METHODS: A cross-sectional study was conducted with a probability adult household sample (n?=?1,464) in the city of São Paulo, Brazil. Alcohol intake and ICD-10 psychopathology diagnoses were assessed with the Composite International Diagnostic Interview 1.1. The analyses focused on the prevalence and determinants of 12-month non-heavy drinking, heavy episodic drinking (4-5 drinks per occasion), and heavy and frequent drinking (heavy drinking at least 3 times/week), as well as associated alcohol-related problems according to drinking patterns and gender. RESULTS: Nearly 22% (32.4% women, 8.7% men) of the subjects were lifetime abstainers, 60.3% were non-heavy drinkers, and 17.5% reported heavy drinking in a 12-month period (26.3% men, 10.9% women). Subjects with the highest frequency of heavy drinking reported the most problems. Among subjects who did not engage in heavy drinking, men reported more problems than did women. A gender convergence in the amount of problems was observed when considering heavy drinking patterns. Heavy and frequent drinkers were twice as likely as abstainers to present lifetime depressive disorders. Lifetime nicotine dependence was associated with all drinking patterns. Heavy and frequent drinking was not restricted to young ages. CONCLUSIONS: Heavy and frequent episodic drinking was strongly associated with problems in a community sample from the largest city in Latin America. Prevention policies should target this drinking pattern, independent of age or gender. These findings warrant continued research on risky drinking behavior, particularly among persistent heavy drinkers at the non-dependent level.

Silveira, Camila Magalhaes; Siu, Erica Rosanna; Wang, Yuan-Pang; Viana, Maria Carmen; de Andrade, Arthur Guerra; Andrade, Laura Helena

2012-01-01

181

Analysing Cognitive or Non-Cognitive Factors Involved in the Process of Physics Problem-Solving in an Everyday Context  

ERIC Educational Resources Information Center

Recently, the importance of an everyday context in physics learning, teaching, and problem-solving has been emphasized. However, do students or physics educators really want to learn or teach physics problem-solving in an everyday context? Are there not any obstructive factors to be considered in solving the everyday context physics problems? To…

Park, Jongwon; Lee, Limook

2004-01-01

182

The effects of environmental variability and spatial sampling on the three-dimensional inversion problem.  

PubMed

The overall goal of this work is to quantify the effects of environmental variability and spatial sampling on the accuracy and uncertainty of estimates of the three-dimensional ocean sound-speed field. In this work, ocean sound speed estimates are obtained with acoustic data measured by a sparse autonomous observing system using a perturbative inversion scheme [Rajan, Lynch, and Frisk, J. Acoust. Soc. Am. 82, 998-1017 (1987)]. The vertical and horizontal resolution of the solution depends on the bandwidth of acoustic data and on the quantity of sources and receivers, respectively. Thus, for a simple, range-independent ocean sound speed profile, a single source-receiver pair is sufficient to estimate the water-column sound-speed field. On the other hand, an environment with significant variability may not be fully characterized by a large number of sources and receivers, resulting in uncertainty in the solution. This work explores the interrelated effects of environmental variability and spatial sampling on the accuracy and uncertainty of the inversion solution though a set of case studies. Synthetic data representative of the ocean variability on the New Jersey shelf are used. PMID:24907793

Bender, Christopher M; Ballard, Megan S; Wilson, Preston S

2014-06-01

183

Psychopathological status, behavior problems, and family adjustment of Kuwaiti children whose fathers were involved in the first gulf war  

PubMed Central

Objectives Following the end of the Gulf War that resulted in the liberation of Kuwait, there are no reports on the impact of veterans' traumatic exposure and posttraumatic stress disorder (PTSD) on their children. We compared the severity of anxiety, depression, deviant behavior and poor family adjustment among the children of a stratified random sample of four groups of Kuwaiti military men, viz: the retired; an active -in-the-army group (AIA) (involved in duties at the rear); an in-battle group (IB) (involved in combat); and a prisoners -of- war (POWs) group. Also, we assessed the association of father's PTSD/combat status and mother's characteristics with child psychosocial outcomes. Method Subjects were interviewed at home, 6 years after the war, using: the Child Behavior Index to assess anxiety, depression, and adaptive behavior; Rutter Scale A2 for deviant behavior; and Family Adjustment Device for adjustment at home. Both parents were assessed for PTSD. Results The 489 offspring (250 m, 239 f; mean age 13.8 yrs) belonged to 166 father-mother pairs. Children of POWs tended to have higher anxiety, depression, and abnormal behavior scores. Those whose fathers had PTSD had significantly higher depression scores. However, children of fathers with both PTSD and POW status (N = 43) did not have significantly different outcome scores than the other father PTSD/combat status groups. Mother's PTSD, anxiety, depression and social status were significantly associated with all the child outcome variables. Parental age, child's age and child's level of education were significant covariates. Although children with both parents having PTSD had significantly higher anxiety/depression scores, the mother's anxiety was the most frequent and important predictor of child outcome variables. The frequency of abnormal test scores was: 14% for anxiety/depression, and 17% for deviant behavior. Conclusion Our findings support the impression that child emotional experiences in vulnerable family situations transcend culture and are associated with the particular behavior of significant adults in the child's life. The primacy of the mother's influence has implications for interventions to improve the psychological functioning of children in such families. Mental health education for these families has the potential to help those in difficulty.

Al-Turkait, Fawziyah A; Ohaeri, Jude U

2008-01-01

184

Reservoir souring: Problems, uncertainties and modelling. Part I: Problems and uncertainty involved in prediction. Part II: Preliminary investigations of a computational model.  

National Technical Information Service (NTIS)

The paper relates to improved oil recovery (IOR) techniques by mathematical modelling. The uncertainty involved in modelling of reservoir souring is discussed. IOR processes are speculated to influence a souring process in a positive direction. Most model...

J. E. Paulsen P. A. Read C. P. Thompson C. Jelley P. Lezeau

1996-01-01

185

Role of the sample boundaries in the problem of dissipative magnetization dynamics  

NASA Astrophysics Data System (ADS)

The Landau–Lifshitz or the Landau–Lifshitz–Gilbert equation of motion for the magnetization M(r,t) a partial integro-differential equation in time and space, for which, in general, an initial value condition and a boundary condition for the field have to be prescribed. This, however, is only true for analytic solutions. It is shown that a unique albeit approximate numerical solution of M(r,t) in a finite sample with surfaces, for which the position dependent form of the effective field occurring in these equations with position dependent material parameters is used, no boundary condition of the magnetization is required. The analytical boundary conditions nevertheless play an important role also in numerical simulations, since they provide valuable estimates required for the accurate calculation of the exchange field at the surfaces.

Fähnle, Manfred; Slavin, Andrei; Hertel, Riccardo

2014-06-01

186

Importance Sampling Implemented in the Code PRIZMA for Deep Penetration and Detection Problems in Reactor Physics  

NASA Astrophysics Data System (ADS)

At RFNC-VNIITF a code PRIZMA which has been developed for more than 30 years is used to model radiation transport by the Monte Carlo method. The code implements individual and coupled tracking of neutrons, photons, electrons, positrons and ions in 1D, 2D or 3D geometry. Attendance estimators are used for tallying, i.e., the estimators whose scores are only nonzero from particles which cross a region or surface of interest. Importance sampling is used to make deep penetration and detection calculations more effective. However, its application to reactor analysis appeared peculiar and required further development. The paper reviews methods used for deep penetration and detection calculations by PRIZMA. It describes in what these calculations differ when applied to reactor analysis and how we compute approximated importance functions and parameters for biased distributions. Methods to control the statistical weight of particles are also discussed. A number of test and applied calculations which were done for the purpose of verification are provided. They are shown to agree either with asymptotic solutions if exist, or with results of analog calculations or predictions by other codes. The applied calculations include the estimation of ex-core detector response from neutron sources arranged in the core, and the estimation of in-core detector response.

Kandiev, Y. Z.; Zatsepin, O. V.

2014-06-01

187

Hyperbolic heat conduction problems involving non-Fourier effects - Numerical simulations via explicit Lax-Wendroff/Taylor-Galerkin finite element formulations  

NASA Technical Reports Server (NTRS)

Numerical simulations are presented for hyperbolic heat-conduction problems that involve non-Fourier effects, using explicit, Lax-Wendroff/Taylor-Galerkin FEM formulations as the principal computational tool. Also employed are smoothing techniques which stabilize the numerical noise and accurately predict the propagating thermal disturbances. The accurate capture of propagating thermal disturbances at characteristic time-step values is achieved; numerical test cases are presented which validate the proposed hyperbolic heat-conduction problem concepts.

Tamma, Kumar K.; Namburu, Raju R.

1989-01-01

188

Parents with Mental Illness: Decision?making in Australian Children's Court Cases Involving Parents with Mental Health Problems  

Microsoft Academic Search

Mental illness is listed as a child protection concern for a number of families reported to child protection agencies in Australia. Parents with mental health problems are more vulnerable, as are their children, to having parenting and child welfare concerns. Studies undertaken in the Melbourne Children's Court (Victoria) have found that the children of parents with mental health problems comprise

Rosemary Sheehan; Greg Levine

2005-01-01

189

Application of the finite-difference time-domain method to scattering and radiation problems involving wires and plates  

Microsoft Academic Search

Numerical modeling of electromagnetic (EM) interaction is normally performed by using either differential or integral equation methods. Both techniques can be implemented to solve problems in frequency or time domain. The method of moments (MOM) approach to solving integral equations has matured to the point where it can be used to solve complex problems. In the past, MOM has only

B. Beker

1992-01-01

190

Hyperdynamics Importance Sampling  

Microsoft Academic Search

Sequential random sampling ('Markov Chain Monte-Carlo') is a popular strategy for many vision problems involving multimodal distributions over high-dimensional parameter spaces. It applies both to importance sampling (where one wants to sample points according to their 'im- portance' for some calculation, but otherwise fairly) and toglobal optimization (where one wants to find good minima, or at least good starting points

Cristian Sminchisescu; Bill Triggs

2002-01-01

191

SASS Documentation: 1993-94 SASS Student Sampling Problems; Solutions for Determining the Numerators for the SASS Private School (3B) Second-Stage Factors. Working Paper Series.  

ERIC Educational Resources Information Center

This document contains two papers related to the 1993-94 Schools and Staffing Survey (SASS). The first paper documents some of the problems that were encountered during student sample selection and the methods used to resolve those problems. It also provides some suggestions to alleviate some of the problems in future SASS studies. Significant…

Cole, Cornette; Schwanz, Dennis J.

192

Drug driving and the management of risk: the perspectives and practices of a sample of problem drug users.  

PubMed

This paper reports on a qualitative study of the attitudes and risk management strategies of a sample of problem drug users in relation to driving while under the influence of drugs. Interviews were conducted with 26 individuals (21 men and 5 women) all of whom had been addicted to heroin and had admitted to driving while under the influence of illegal drugs. The drug users reported four main strategies for managing the risks associated with drug driving: attempting to limit their drug intake to their tolerance level; delaying driving after taking a drug until they felt safe; stopping driving if they felt unsafe while behind the wheel; and avoiding driving altogether under the influence of certain drugs. However, the interviewees' accounts of their drug driving behaviour suggest that these strategies are not only far from reliable, they may also act to encourage drug driving by creating a false sense of security. The reassurance they provide may also undermine any educational messages targeting drug driving. There was little in the problem users' accounts to suggest that media campaigns or a more effective method of detection would have much influence upon their behaviour. The paper concludes that the most realistic approach to the problem may be to incorporate drug driving interventions within drug treatment programmes. PMID:18502377

McIntosh, James; O'Brien, Tommy; McKeganey, Neil

2008-06-01

193

Self-Report Measures of Child and Adolescent Psychopathy as Predictors of Offending in Four Samples of Justice-Involved Youth  

Microsoft Academic Search

The authors examined the relation between self-report psychopathy measures and o ficial records of o fending in four samples of justice-involved youth (total N = 447). Psychopathy measures included the Antisocial Process Screening Device (APSD) and a modified version of the Childhood Psychopathy Scale (mCPS). Measures of o fending included the total number of preadmission arrest charges for three samples

Marcus T. Boccaccini; Monica Epstein; Norman Poythress; Kevin S. Douglas; Justin Campbell; Gail Gardner; Diana Falkenbach

2007-01-01

194

ITOUGH2 Sample Problems.  

National Technical Information Service (NTIS)

iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media. This report contains a collection of iTOUGH2 s...

S. Finsterle

2002-01-01

195

[Multi-organ procurement from the perspective of a hospital not involved in transplantation. Requirements, implementation, problems].  

PubMed

Our algorithm is an example in which way the multiple organ donation can be organised in a hospital, which doesn't perform transplantations. We are showing problems which occur during the evaluation of the donor and till the explantation can be performed. In the conclusion we are demanding for better coordination and better support from the transplantation centers. PMID:8473182

Lichtenhahn, P; Bissat, A; Meyenberg, A; Aeberhard, P

1993-03-01

196

Self-Report Measures of Child and Adolescent Psychopathy as Predictors of Offending in Four Samples of Justice-Involved Youth  

ERIC Educational Resources Information Center

The authors examined the relation between self-report psychopathy measures and official records of offending in four samples of justice-involved youth (total N = 447). Psychopathy measures included the Antisocial Process Screening Device (APSD) and a modified version of the Childhood Psychopathy Scale (mCPS). Measures of offending included the…

Boccaccini, Marcus T.; Epstein, Monica; Poythress, Norman; Douglas, Kevin S.; Campbell, Justin; Gardner, Gail; Falkenbach, Diana

2007-01-01

197

Analysis of Korean High School Students' Decision-Making Processes in Solving a Problem Involving Biological Knowledge  

ERIC Educational Resources Information Center

In this study, the cognitive characteristics of students' decision-making processes centered on phases, difficulties, and strategies are analysed in the personal dailylife context involving biological knowledge. The subjects were first year science and general high school students in Seoul, Korea; 6 female students and 7 male students. The…

Hong, Jung-Lim; Chang, Nam-Kee

2004-01-01

198

Negative-energy states in the Dirac-Hartree-Fock problem - The effect of omission of two-electron integrals involving the small component  

NASA Technical Reports Server (NTRS)

The effect of omission of two-electron integrals involving basis functions for the small component of the wavefunction on the eigenvalue spectrum in the Dirac-Hartree-Fock problem is studied. From an analysis of the Fock matrix it is shown that omission of these integrals moves the negative-energy states down, not up. Their complete omission does not give rise to intruder states. The appearance of intruder states occurs when only some of the core integrals are omitted, due to the nature of particular contraction schemes used for the core basis functions. Use of radially localized functions rather than atomic functions alleviates the intruder state problem.

Dyall, Kenneth G.

1992-01-01

199

total 93 new infections strap. Iberis detected 22 665 ...... Milk samples 10 herds Staph. aureus GTR herd problems (PH cases) ...... frequent cause bacterium gastrointestinal diseases principally .  

EPA Pesticide Factsheets

Did you mean: total 93 new infections strap. Iberis detected 22 665 ...... Milk samples 10 herds Staph. aureus GTR herd problems (PH cases) ...... frequent cause bacterium gastrointestinal diseases principally . ?

200

A logistic regression model for small sample classification problems with hidden variables and non-linear relationships: an application in business analytics  

Microsoft Academic Search

Logistic regression is one of the frequently used models in pattern recognition, especially in binary classification tasks. We focus on a class of small-sample classification problems where logistic regression seems to be a \\

A. Mojsilovic

2005-01-01

201

Gas generation and migration studies involving recently generated /sup 238/Pu-contaminated waste for the TRU Waste Sampling Program  

SciTech Connect

This study is part of the multicontractor TRU Waste Sampling Program. Radiolytically generated gases were vented through a filtering device to determine its effectiveness in maintaining hydrogen concentrations within acceptably safe levels. In the second part of the study measurements were made to determine the ability of these gases, particularly hydrogen, to migrate through a sealed rigid polyethylene drum liner. Void volumes in these drums were found to be generally in excess of 90%. The carbon composite filter was found to satisfactorily vent hydrogen up to moderately high levels of alpha activity in the waste substrate. The sealed 90-mil liner was found to inhibit, but not prevent, the migration of hydrogen and other radiolytically generated gases.

Zerwekh, A.; Warren, J.L.

1986-07-01

202

The Relative Effects of Maternal and Child Problems on the Quality of Attachment: A Meta-Analysis of Attachment in Clinical Samples.  

ERIC Educational Resources Information Center

Distributions of child attachment classifications in mother-child dyads in which the mother evidenced physical or mental problems were highly divergent from distributions for normal samples. Distributions of child attachment classifications in mother-child dyads in which the child evidenced physical problems were similar to distributions in normal…

van IJzendoorn, Marinus H.; And Others

1992-01-01

203

Computationally efficient parabolic equation solutions to seismo-acoustic problems involving thin or low-shear elastic layers.  

PubMed

Shallow-water environments typically include sediments containing thin or low-shear layers. Numerical treatments of these types of layers require finer depth grid spacing than is needed elsewhere in the domain. Thin layers require finer grids to fully sample effects due to elasticity within the layer. As shear wave speeds approach zero, the governing system becomes singular and fine-grid spacing becomes necessary to obtain converged solutions. In this paper, a seismo-acoustic parabolic equation solution is derived utilizing modified difference formulas using Galerkin's method to allow for variable-grid spacing in depth. Propagation results are shown for environments containing thin layers and low-shear layers. PMID:23556690

Metzler, Adam M; Collis, Jon M

2013-04-01

204

Promises and problems for the new paradigm for risk assessment and an alternative approach involving predictive systems models.  

PubMed

The need for cost-effective risk assessment of chemicals is leading to the development of a reductionist paradigm that tries to assess impacts on humans and ecosystems from molecular changes. However, the biggest challenge for this paradigm comes from the emergence of properties that arise out of the interactions of the parts that are not included and yet which are key for assessing likely impacts. Although identifying key events and adverse outcome pathways can shed light on the involvement of important metabolic processes in toxicity, this does not mean that particular molecular initiating events are likely to be robust or accurate predictors of impacts that matter. There are even greater challenges for the new paradigm applied to ecological systems than to human health because of the need to link across more levels of biological organization. The present study argues for a predictive systems approach that makes the linkages through systems models in a mechanistic way that allows for emergence and that also has the potential for reducing the costs and use of animals in ecological risk assessments. PMID:23165997

Forbes, Valery E; Calow, Peter

2012-12-01

205

Genotyping DNA pools on microarrays: Tackling the QTL problem of large samples and large numbers of SNPs  

PubMed Central

Background Quantitative trait locus (QTL) theory predicts that genetic influence on complex traits involves multiple genes of small effect size. To detect QTL associations of small effect size, large samples and systematic screens of thousands of DNA markers are required. An efficient solution is to genotype case and control DNA pools using SNP microarrays. We demonstrate that this is practical using DNA pools of 100 individuals. Results Using standard microarray protocols for the Affymetrix GeneChip® Mapping 10 K Array Xba 131, we show that relative allele signal (RAS) values provide a quantitative index of allele frequencies in pooled DNA that correlate 0.986 with allele frequencies for 104 SNPs that were genotyped individually for 100 individuals. The sensitivity of the assay was demonstrated empirically in a spiking experiment in which 15% and 20% of one individual's DNA was added to a DNA pool. Conclusion We conclude that this approach, which we call SNP-MaP (SNP microarrays and pooling), is rapid, cost effective and promises to be a valuable initial screening method in the hunt for QTLs.

Meaburn, Emma; Butcher, Lee M; Liu, Lin; Fernandes, Cathy; Hansen, Valerie; Al-Chalabi, Ammar; Plomin, Robert; Craig, Ian; Schalkwyk, Leonard C

2005-01-01

206

Familial Confounding of the Association Between Maternal Smoking during Pregnancy and Offspring Substance Use and Problems: Converging Evidence Across Samples and Measures  

PubMed Central

Context Previous epidemiological, animal, and human cognitive neuroscience research suggests that maternal smoking during pregnancy causes increased risk of offspring substance use/problems. Objective To determine the extent to which the association between SDP and offspring substance use/problems depends on confounded familial background factors by using a quasi-experimental design. Design We used two separate samples, from the United States and from Sweden, respectively. The analyses prospectively predicted multiple indices of substance use and problems while controlling for statistical covariates and comparing differentially exposed siblings to minimize confounding. Setting Sample 1: Offspring of a representative sample of women in the United States. Sample 2: The total Swedish population born over 13 years. Patients or Other Participants Sample 1: Adolescent offspring of the women in the National Longitudinal Survey of Youth 1979 (n=6,094). Sample 2: All offspring born in Sweden from 1983 through 1995 (n=1,187,360). Main Outcome Measures Sample 1: Self-reported adolescent alcohol, cigarette, and marijuana use, and early onset (before age 14 years) of each substance. Sample 2: Substance-related convictions and hospitalizations for an alcohol- or drug-related problem. Results The same pattern emerged for each index of substance use/problems across the two samples. At the population level maternal smoking during pregnancy predicted every measure of offspring substance use/problems in both samples, ranging from adolescent alcohol use (HRmoderate=1.32, CI=1.22–1.43; HRhigh=1.33, CI=1.17=1.53) to a narcotic convictions (HRmoderate=2.23, CI=2.14–2.31; HRhigh=2.97, CI=2.86–3.09). When comparing differentially exposed siblings to minimize genetic and environmental confounds, however, the association between SDP and each measure of substance use/problems was minimal and not statistically significant. Conclusions The association between maternal smoking during pregnancy and offspring substance use/problems was likely due to familial background factors, not a causal influence, because siblings had similar rates of substance use and problems regardless of their specific exposure to smoking during pregnancy.

D'Onofrio, Brian M.; Rickert, Martin E.; Langstrom, Niklas; Donahue, Kelly L.; Coyne, Claire A.; Larsson, Henrik; Ellingson, Jarrod M.; Van Hulle, Carol A.; Iliadou, Anastasia N.; Rathouz, Paul J.; Lahey, Benjamin B.; Lichtenstein, Paul

2013-01-01

207

Pervasive and Non?pervasive Conduct Problems in a Clinic Sample Aged 4–8 years: Child, family and day?care\\/school factors  

Microsoft Academic Search

Differences between pervasive (home and day?care\\/school) versus non?pervasive (home only) conduct problems were examined in regard to various child, parent\\/family, and day?care\\/school characteristics in an outpatient clinic sample of 120 children aged 4–8 years. All children scored above the 90th percentile on the Eyberg Child Behavior Inventory for home problems and met the criteria for a possible or a confirmed

May Britt Drugli; Bo Larsson; Graham Clifford; Sturla Fossum

2007-01-01

208

Area Problems Involving Kasner Polygons  

Microsoft Academic Search

Sequences of polygons generated by performing iterative processes on an initial polygon have been studied extensively. One of the most popular sequences is the one sometimes referred to as {\\\\it Kasner polygons}. Given a polygon $K$, the first Kasner descendant $K'$ of $K$ is obtained by placing the vertices of $K'$ at the midpoints of the edges of $K$. More

Dan Ismailescu; Minsuk Kim; Kyung Jae Lee; Seong Hoon Lee

2009-01-01

209

Parent-Reported Attention-Deficit/Hyperactivity Disorder Symptomatology and Sleep Problems in a Preschool-Age Pediatric Clinic Sample  

ERIC Educational Resources Information Center

The study investigates the relation between attention-deficit/hyperactivity disorder symptomatology and parent-reported sleep problems among preschoolers aged 2 to 5 years. Results indicate that neither condition was uniquely related to parent-reported sleep problems, but inattentive symptomatology was uniquely associated with daytime sleepiness.

Willoughby, Michael T.; Angold, Adrian; Egger, Helen L.

2008-01-01

210

Differences in Parent and Teacher Ratings of Preschool Problem Behavior in a National Sample: The Significance of Gender and SES  

ERIC Educational Resources Information Center

Previous research has demonstrated that informant disagreement is common with the use of rating scales to assess problem behavior in school-age populations. However, much less is known about this phenomenon in preschool populations. This is important because the accurate assessment of problem behavior in preschool is complex due to the rapid…

Graves, Scott L., Jr.; Blake, Jamilia; Kim, Eun Sook

2012-01-01

211

Application of Theorem Proving to Problem Solving  

Microsoft Academic Search

This paper shows how an extension of the resolution proof procedure can be used to con­ struct problem solutions. The extended proof procedure can solve problems involving state transformations. The paper explores several alternate problem representations and provides a discussion of solutions to sample problems including the \\

C. Cordell Green

1969-01-01

212

Stress, Mental Health, and Substance Abuse Problems in a Sample of Diversion Program Youths: An Exploratory Latent Class Analysis  

Microsoft Academic Search

Reflective of interest in mental health and substance abuse issues among youths involved with the justice system, we performed a latent class analysis on baseline information collected on 100 youths involved in two diversion programs. Results identified two groups of youths: Group 1: a majority of the youths, who had high levels of delinquency, mental health, and substance abuse issues;

Richard Dembo; Rhissa Briones; Laura Gulledge; Lora Karas; Ken C. Winters; Steven Belenko; Paul E. Greenbaum

2012-01-01

213

Sleep problems and daytime somnolence in a German population-based sample of snoring school-aged children.  

PubMed

Habitual snoring is associated with daytime symptoms like tiredness and behavioral problems. Its association with sleep problems is unclear. We aimed to assess associations between habitual snoring and sleep problems in primary school children. The design was a population-based cross-sectional study with a nested cohort study. The setting was twenty-seven primary schools in the city of Hannover, Germany. Habitual snoring and sleep problems were assessed in primary school children using an extended version of Gozal's sleep-disordered breathing questionnaire (n = 1144). Approximately 1 year later, parents of children reported to snore habitually (n = 114) and an equal number of children who snored never or occasionally were given the Sleep Disturbance Scale for Children, a validated questionnaire for the assessment of pediatric sleep problems. Snoring status was re-assessed using the initial questionnaire and children were then classified as long-term habitual snorers or ex-habitual snorers. An increasing prevalence of sleep problems was found with increasing snoring frequency for sleep-onset delay, night awakenings, and nightmares. Long-term habitual snorers were at significantly increased risk for sleep-wake transition disorders (e.g. rhythmic movements, hypnic jerks, sleeptalking, bruxism; odds ratio, 95% confidence interval: 12.0, 3.8-37.3), sleep hyperhidrosis (3.6, 1.2-10.8), disorders of arousal/nightmares (e.g. sleepwalking, sleep terrors, nightmares; 4.6, 1.3-15.6), and excessive somnolence (i.e. difficulty waking up, morning tiredness, daytime somnolence; 6.3, 2.2-17.8). Ex-habitual snorers were at increased risk for sleep-wake transition disorders (4.4, 1.4-14.2). Habitual snoring was associated with several sleep problems in our study. Long-term habitual snorers were more likely to have sleep problems than children who had stopped snoring spontaneously. PMID:17309768

Eitner, Steffen; Urschitz, Michael S; Guenther, Anke; Urschitz-Duprat, Pilar M; Bohnhorst, Bettina; Schlaud, Martin; Poets, Christian F

2007-03-01

214

Are Problems Prevalent and Stable in Non-Clinical Populations? Problems and Test-Retest Stability of a Patient-Generated Measure, PSYCHLOPS (Psychological Outcome Profiles), in a Non-Clinical Student Sample  

ERIC Educational Resources Information Center

In straightened times counselling must evidence the changes it promotes on reputable measures. Patient-generated measures complement nomothetic measures and may be nearer the ethos of counselling in eliciting individuals' problems. Scores from such measures from non-clinical samples are rarely reported, making their test-retest stability…

Evans, Chris; Ashworth, Mark; Peters, Marilyn

2010-01-01

215

Associations of Patient Health-Related Problem Solving with Disease Control, Emergency Department Visits, and Hospitalizations in HIV and Diabetes Clinic Samples  

PubMed Central

Background Patient problem solving and decision making are recognized as essential to effective self-management across multiple chronic diseases. However, a health-related problem-solving instrument that demonstrates sensitivity to disease control parameters in multiple diseases has not been established. Objectives To determine, in two disease samples, internal consistency and associations with disease control of the Health Problem-Solving Scale (HPSS), a 50-item measure with 7 subscales assessing effective and ineffective problem-solving approaches, learning from past experiences, and motivation/orientation. Design Cross-sectional study. Participants Outpatients from university-affiliated medical center HIV (N?=?111) and diabetes mellitus (DM, N?=?78) clinics. Measurements HPSS, CD4, hemoglobin A1c (HbA1c), and number of hospitalizations in the previous year and Emergency Department (ED) visits in the previous 6 months. Results Administration time for the HPSS ranged from 5 to 10 minutes. Cronbach’s alpha for the total HPSS was 0.86 and 0.89 for HIV and DM, respectively. Higher total scores (better problem solving) were associated with higher CD4 and fewer hospitalizations in HIV and lower HbA1c and fewer ED visits in DM. Health Problem-Solving Scale subscales representing negative problem-solving approaches were consistently associated with more hospitalizations (HIV, DM) and ED visits (DM). Conclusions The HPSS may identify problem-solving difficulties with disease self-management and assess effectiveness of interventions targeting patient decision making in self-care.

Gemmell, Leigh; Kulkarni, Babul; Klick, Brendan; Brancati, Frederick L.

2007-01-01

216

Initial Reliability and Validity of the Life Satisfaction Scale for Problem Youth in a Sample of Drug Abusing and Conduct Disordered Youth  

ERIC Educational Resources Information Center

Responses to Life Satisfaction Scale for Problem Youth (LSSPY) items were examined in a sample of 193 substance abusing and conduct disordered adolescents. In responding to the LSSPY, youth endorse their percentage of happiness (0 to 100%) in twelve domains (i.e., friendships, family, school, employment/work, fun activities, appearance, sex…

Donohue, Brad; Teichner, Gordon; Azrin, Nathan; Weintraub, Noah; Crum, Thomas A.; Murphy, Leah; Silver, N. Clayton

2003-01-01

217

The Problems with Access to Compulsory Education in China and the Effects of the Policy of Direct Subsidies to Students: An Empirical Study Based on a Small Sample  

ERIC Educational Resources Information Center

After a brief review of the achievements and the problems in compulsory education enrollment in the thirty years since the reform and opening up, this study analyzes the current compulsory education enrollment and dropout rates in China's least-developed regions and the factors affecting school enrollment based on survey data from a small sample

Yanqing, Ding

2012-01-01

218

Diagnostic Performance of the CBCL-Attention Problem Scale as a Screening Measure in a Sample of Brazilian Children with ADHD  

ERIC Educational Resources Information Center

Objective: To evaluate the diagnostic performance of the Attention Problem Scale of the Child Behavior Checklist (CBCL-APS) for the screening of Attention-Deficit/Hyperactivity Disorder (ADHD) in a sample of Brazilian children and adolescents. Methods: The CBCL-APS was given to 763 children and adolescents. Child psychiatrists using DSM-IV…

Lampert, T. L.; Polanczyk, G.; Tramontina, S.; Mardini, V.; Rohde, L. A.

2004-01-01

219

Pervasive and Non-Pervasive Conduct Problems in a Clinic Sample Aged 4-8 Years: Child, Family and Day-Care/School Factors  

ERIC Educational Resources Information Center

Differences between pervasive (home and day-care/school) versus non-pervasive (home only) conduct problems were examined in regard to various child, parent/family, and day-care/school characteristics in an outpatient clinic sample of 120 children aged 4-8 years. All children scored above the 90th percentile on the Eyberg Child Behavior Inventory…

Drugli, May Britt; Larsson, Bo; Clifford, Graham; Fossum, Sturla

2007-01-01

220

Epidemiological study on behavioural and emotional problems in developmental age: prevalence in a sample of Italian children, based on parent and teacher reports  

PubMed Central

Background The aim of this study is to examine the prevalence of behavioural and emotional problems in a sample of school children living in Campania, a region of South Italy. Methods The Child Behavior Checklist (CBCL) Parent Report Form (PRF) and the CBCL Teacher Rating Form (TRF) were administered to parents and teachers of a sample of school children aged 8-9 yr. Results The subjects (SS) eligible for the study were 3072. In 2137 (69.5%) cases parents returned the envelopes back. 1228 (57.4%) subjects were excluded because of lack of signed consensus, unfilled or incomplete forms. Parents reported children’s behavioural or emotional Total Problems in 14.7% of the SS. (5.2% borderline, 9.5% clinical), Internalizing Problems in 18.5% (8.0% borderline, 10.5% clinical), and Externalizing Problems in 8.5% (3.8% borderline, 4.7% clinical) respectively. At the Competence Scale of CBCL more than 2/3 of the sample show high rate for Total Competence Problem (24.3% borderline, 47.3% clinical.) Teachers reported 8.7% of SS having Total Problems, (4.3% borderline, 4.4% clinical), Internalizing problems were detected in 13.3% of the sample (4.9% borderline and 8.4% clinical), while Externalizing problems were reported for 9.6% of SS (4.1% borderline and 5.5% clinical). In the sub-scale of Academic Performances teachers report a high number of subjects with problems, 18.7%, whose 4.3% had a “borderline” score, and 14.4% had a “clinical” score. Conclusion Concerning Total Problems (clinical and borderline SS, 14.7% as reported by parents, 8.7% as reported by teachers) we obtained a prevalence similar to that reported in the rest of the country, with differences in gender (males 13.2%, females 16.0% as reported by parents; males 7.4%, females 9.7% as reported by teachers). The difficulties in social and relationship competencies area were higher (4/10 children). This datum should be cautiously evaluated because the possible inadequacy of CBCL competences scale.

2014-01-01

221

Sample Sixth Grade Problem-Based Learning (PBL) Lesson: The Ancient World Explorers: Space Invaders, Copycats, or Independent Inventors.  

ERIC Educational Resources Information Center

Outlines a social studies lesson plan that follows the Problem Based Learning model. Provides the lesson goal, questions for students, instructions for teachers and students, instructional materials, Internet resources for student research, preparation hints for teachers, and reflective learning questions for students at the end of the project.…

Benoit, Ty

1998-01-01

222

Predictors and Moderators of Parent Training Efficacy in a Sample of Children with Autism Spectrum Disorders and Serious Behavioral Problems  

ERIC Educational Resources Information Center

The Research Units on Pediatric Psychopharmacology-Autism Network reported additional benefit when adding parent training (PT) to antipsychotic medication in children with autism spectrum disorders and serious behavior problems. The intent-to-treat analyses were rerun with putative predictors and moderators. The "Home Situations Questionnaire"…

Farmer, Cristan; Lecavalier, Luc; Yu, Sunkyung; Arnold, L. Eugene; McDougle, Christopher J.; Scahill, Lawrence; Handen, Benjamin; Johnson, Cynthia R.; Stigler, Kimberly A.; Bearss, Karen; Swiezy, Naomi B.; Aman, Michael G.

2012-01-01

223

Attention Problems Mediate the Association between Severity of Physical Abuse and Aggressive Behavior in a Sample of Maltreated Early Adolescents  

ERIC Educational Resources Information Center

Empirical evidence has accumulated documenting an association between childhood physical abuse and aggressive behavior. Relatively fewer studies have explored possible mediating mechanisms that may explain this association. The purpose of the current study was to examine whether caregiver- and youth-reported attention problems mediate the…

Garrido, Edward F.; Taussig, Heather N.; Culhane, Sara E.; Raviv, Tali

2011-01-01

224

The Problem Areas in Diabetes (PAID) scale: psychometric evaluation survey in a Greek sample with type 2 diabetes.  

PubMed

Several instruments have been developed for the assessment of emotional distress in patients with diabetes. The Problem Areas in Diabetes Scale (PAID) is a brief self-report scale that evaluates diabetes-related distress. There is a lack of validated instruments for the evaluation of psychological aspects in patients with diabetes in Greek language. The current study was conducted to translate and adapt the PAID scale in Greek language and to evaluate the psychometric properties in two different study populations of patients with diabetes. The aim of this study was to translate the Problem Areas in Diabetes (PAID) scale into Greek, adapt it culturally to Greece and determine its psychometric properties. The translation process included two forward translations, reconciliation, backward translation and pre-testing steps. The validation incorporated the exploration of internal consistency (Cronbach's alpha), test-retest reliability (interclass correlation coefficient), construct validity (exploratory factor analysis) and responsiveness (Spearman correlation coefficient). Participants included 101 consecutive patients from a rural primary healthcare centre and 101 patients from an urban hospital. All patients completed the PAID scale and the Short Form-36 (SF-36) version 2. Internal consistency considered good (Cronbach's alpha = 0.948). Interclass correlation coefficient was 0.942 (95% CI 0.915-0.961). Factor analysis yielded three factors: 'Diabetes-related emotional problems' (51.79% variance, Cronbach's alpha = 0.910), 'Food-related problems' (9.55% variance, Cronbach's alpha = 0.824) and 'Social support-related problems' (5.96% variance, Cronbach's alpha = 0.704). Screen plot test and conceptual congruency of items supported a three-factor solution. Total PAID showed a negative correlation with both SF-36 mental component summary (r = -0.733, P < 0.0001) and SF-36 physical component summary (r = -0.594, P < 0.0001). Our findings indicate that the Greek version of the PAID questionnaire is reliable and valid for patients with diabetes mellitus in Greece. PMID:22340071

Papathanasiou, A; Koutsovasilis, A; Shea, S; Philalithis, A; Papavasiliou, S; Melidonis, A; Lionis, C

2014-05-01

225

Reasons for Starting and Continuing Gambling in a Mixed Ethnic Community Sample of Pathological and Non-problem Gamblers  

Microsoft Academic Search

Very few studies have investigated motivational differences between pathological gamblers (PG) and non-problem gamblers (NPG), or between men and women. Motives for starting gambling have not been distinguished from motives for continuing gambling. From a community survey questionnaire listing reasons generated from the population studied, the motives of 103 current PG met the DSM-IV-TR criteria of five or more symptoms

DAVE CLARKE; SAMSON TSE; MAX W. ABBOTT; SONIA TOWNSEND; PEFI KINGI; WIREMU MANAIA

2007-01-01

226

A New Criterion for the Optimal Software Release Problems: Moving Average Quality Control Chart with Bootstrap Sampling  

Microsoft Academic Search

This paper proposes a new practical method for determining when to stop software testing. This issue has been widely known\\u000a as the optimal release problem of software product, and many researchers have been developing mathematical models for finding\\u000a the solution.\\u000a \\u000a We try to develop a new quality control charting to help making the right decision for it, by employing the

Mitsuhiro Kimura; Takaji Fujiwara

227

Sex Differences in Childhood Sexual Abuse Characteristics and Victims' Emotional and Behavioral Problems: Findings from a National Sample of Youth  

ERIC Educational Resources Information Center

Objective: The first objective of this study was to test for sex differences in four childhood sexual abuse characteristics--penetration, substantiation, perpetrator familial status, and multi-maltreatment--in a national sample of youth. The second objective was to test for sex differences in how these abuse characteristics were associated with…

Maikovich-Fong, Andrea Kohn; Jaffee, Sara R.

2010-01-01

228

Mental Disorders and Problem Behavior in a Community Sample of Adults with Intellectual Disability: Three-Month Prevalence and Comorbidity  

ERIC Educational Resources Information Center

The aim of this study was to investigate the prevalence of mental disorders in a Norwegian sample of adults with intellectual disability (ID) using the "Psychopathology Checklists for Adults With Intellectual Disability" (P-AID; Hove & Havik, 2008), a screening instrument adopting diagnostic criteria from the "Diagnostic Criteria for Psychiatric…

Hove, Oddbjorn; Havik, Odd E.

2008-01-01

229

Multivariate Analysis, Retrieval, and Storage System (MARS). Volume 6: MARS System - A Sample Problem (Gross Weight of Subsonic Transports)  

NASA Technical Reports Server (NTRS)

The Mars system is a tool for rapid prediction of aircraft or engine characteristics based on correlation-regression analysis of past designs stored in the data bases. An example of output obtained from the MARS system, which involves derivation of an expression for gross weight of subsonic transport aircraft in terms of nine independent variables is given. The need is illustrated for careful selection of correlation variables and for continual review of the resulting estimation equations. For Vol. 1, see N76-10089.

Hague, D. S.; Woodbury, N. W.

1975-01-01

230

Determination of arsenic in plant samples by inductively coupled plasma atomic emission spectrometry with ultrasonic nebulization: a complex problem  

NASA Astrophysics Data System (ADS)

Under well-defined conditions, the analysis of most trace elements by inductively coupled plasma atomic emission spectrometry with ultrasonic nebulization (ICP-AES-USN) leads to accurate results for environmental matrices usually studied. Due to differences in matrix composition between standards and samples, ICP-AES-USN determinations of arsenic are interfered with by changes that take place mainly within the desolvation stage of the USN device. In this work, effects of plant matrices on the determination of As in six arsenic species have been investigated. Firstly, interferences were simulated by measuring analyte (species) signals in solutions containing variable concentrations of the main matrix elements encountered in mineralized plant samples (K, Ca, Mg, P and Na). Secondly, the influence of real plant matrices on emission signals of arsenic species was also studied. In this case, the observed effects were different than for individual matrix elements considered separately: Ca and Mg always present in real samples efficiently compensate the undesirable effects. Validation of this statement has been performed using mineralized plant reference materials. In addition, ICP-AES-USN results have been compared with those obtained by Zeeman electrothermal atomic absorption spectrometry.

Vassileva, Emilia; Hoenig, Michel

2001-02-01

231

Problem Solving  

NSDL National Science Digital Library

Problem solving is the thought processes involved in solving a problem. It is both a means of developing students' knowledge of mathematics and a critical outcome of a good mathematics education. A mathematical problem, as distinct from an exercise, requires the solver to search for a method for solving the problem rather than following a set procedure. Mathematical problem solving, therefore, requires an understanding of relevant concepts, procedures, and strategies. To become good problem solvers, students need many opportunities to formulate questions, model problem situations in a variety of ways, generalize mathematical relationships, and solve problems in both mathematical and everyday contexts.

K-12 Outreach,

232

The concerned significant others of people with gambling problems in a national representative sample in Sweden - a 1 year follow-up study  

PubMed Central

Background Research into the impact of problem gambling on close social networks is scarce with the majority of studies only including help-seeking populations. To date only one study has examined concerned significant others (CSOs) from an epidemiological perspective and it did not consider gender. The aim of this study is to examine the health, social support, and financial situations of CSOs in a Swedish representative sample and to examine gender differences. Methods A population study was conducted in Sweden in 2008/09 (n?=?15,000, response rate 63%). Respondents were defined as CSOs if they reported that someone close to them currently or previously had problems with gambling. The group of CSOs was further examined in a 1-year follow up (weighted response rate 74% from the 8,165 respondents in the original sample). Comparisons were also made between those defined as CSOs only at baseline (47.7%, n?=?554) and those defined as CSOs at both time points. Results In total, 18.2% of the population were considered CSOs, with no difference between women and men. Male and female CSOs experienced, to a large extent, similar problems including poor mental health, risky alcohol consumption, economic hardship, and arguments with those closest to them. Female CSOs reported less social support than other women and male CSOs had more legal problems and were more afraid of losing their jobs than other men. One year on, several problems remained even if some improvements were found. Both male and female CSOs reported more negative life events in the 1 year follow-up. Conclusions Although some relationships are unknown, including between the CSOs and the individuals with gambling problems and the causal relationships between being a CSO and the range of associated problems, the results of this study indicate that gambling problems not only affect the gambling individual and their immediate close family but also the wider social network. A large proportion of the population can be defined as a CSO, half of whom are men. While male and female CSOs share many common problems, there are gender differences which need to be considered in prevention and treatment.

2013-01-01

233

[Incidence and persistence of problems at sleep onset and sleep continuation in the preschool period: results of a prospective study of a representative sample in Bavaria].  

PubMed

The prevalence and persistence of sleeping problems was studied in a prospective investigation of a representative sample of 432 German children at the ages of 5, 20 and 56 months. 21.5% of children had night waking problems at 5 months, 21.8% at 20 months and 13.3% at 56 months. Falling asleep difficulties were diagnosed in 12.1% of 4-5 year olds. One in four of five year-olds slept regularly in the bed with the parents (co-sleeping). Children with night waking problems had a 2.2 to 2.5 fold increased risk to remain nightwakers from one assessment point to the next compared with non-wakers. 7 to 14% of parents were distressed by their children's sleeping behaviour. Parental behaviour often contributed to continued sleeping problems because the children were not supported in acquiring appropriate skills to settle to sleep unaided. A developmental model for the treatment of sleeping problems is discussed. PMID:7824432

Wolke, D; Meyer, R; Ohrt, B; Riegel, K

1994-11-01

234

Integral Representations for Nonuniform Sampling Expansions.  

National Technical Information Service (NTIS)

The paper investigates an integral representation, involving the Green's function of a boundary-value problem, for the derivation of sampling expansions. The representation is generalized to include non-self-adjoint boundary conditions, and resulting phys...

A. H. Haddad J. B. Thomas

1966-01-01

235

Fast Markov chain Monte Carlo sampling for sparse Bayesian inference in high-dimensional inverse problems using L1-type priors  

NASA Astrophysics Data System (ADS)

Sparsity has become a key concept for solving of high-dimensional inverse problems using variational regularization techniques. Recently, using similar sparsity-constraints in the Bayesian framework for inverse problems by encoding them in the prior distribution has attracted attention. Important questions about the relation between regularization theory and Bayesian inference still need to be addressed when using sparsity promoting inversion. A practical obstacle for these examinations is the lack of fast posterior sampling algorithms for sparse, high-dimensional Bayesian inversion. Accessing the full range of Bayesian inference methods requires being able to draw samples from the posterior probability distribution in a fast and efficient way. This is usually done using Markov chain Monte Carlo (MCMC) sampling algorithms. In this paper, we develop and examine a new implementation of a single component Gibbs MCMC sampler for sparse priors relying on L1-norms. We demonstrate that the efficiency of our Gibbs sampler increases when the level of sparsity or the dimension of the unknowns is increased. This property is contrary to the properties of the most commonly applied Metropolis-Hastings (MH) sampling schemes. We demonstrate that the efficiency of MH schemes for L1-type priors dramatically decreases when the level of sparsity or the dimension of the unknowns is increased. Practically, Bayesian inversion for L1-type priors using MH samplers is not feasible at all. As this is commonly believed to be an intrinsic feature of MCMC sampling, the performance of our Gibbs sampler also challenges common beliefs about the applicability of sample based Bayesian inference.

Lucka, Felix

2012-12-01

236

The [Formula: see text]-sample problem in a multi-state model and testing transition probability matrices.  

PubMed

The choice of multi-state models is natural in analysis of survival data, e.g., when the subjects in a study pass through different states like 'healthy', 'in a state of remission', 'relapse' or 'dead' in a health related quality of life study. Competing risks is another common instance of the use of multi-state models. Statistical inference for such event history data can be carried out by assuming a stochastic process model. Under such a setting, comparison of the event history data generated by two different treatments calls for testing equality of the corresponding transition probability matrices. The present paper proposes solution to this class of problems by assuming a non-homogeneous Markov process to describe the transitions among the health states. A class of test statistics are derived for comparison of [Formula: see text] treatments by using a 'weight process'. This class, in particular, yields generalisations of the log-rank, Gehan, Peto-Peto and Harrington-Fleming tests. For an intrinsic comparison of the treatments, the 'leave-one-out' jackknife method is employed for identifying influential observations. The proposed methods are then used to develop the Kolmogorov-Smirnov type supremum tests corresponding to the various extended tests. To demonstrate the usefulness of the test procedures developed, a simulation study was carried out and an application to the Trial V data provided by International Breast Cancer Study Group is discussed. PMID:23722306

Tattar, Prabhanjan N; Vaman, H J

2014-07-01

237

Molecular dissociation of hydrogen peroxide (HOOH) on a neural network ab initio potential surface with a new configuration sampling method involving gradient fitting.  

PubMed

The O-O bond dissociation of HOOH is investigated on an analytic ab initio potential-energy surface obtained by fitting the energies of 25,608 configurations using neural network (NN) methods. The electronic structure calculations are executed using MP2 calculations with the 6-31G* basis set. A new data-sampling technique is introduced to collect HOOH configurations in the six-dimensional hyperspace. This method is based on a comparison of the NN-computed gradients at configuration points currently in the database with the target gradients. By requiring that the NN gradients closely fit the MP2 target gradients, both the potential and the gradients are more accurately fitted. The selection criteria also ensure a more uniform distribution of configuration points throughout the important regions of configuration space. Molecular dynamics (MD) trajectories are not involved in the sampling. The final NN fitting yields average absolute and root-mean-squared testing set errors of 0.0060 eV (0.58 kJ mol(-1)) and 0.0099 eV (0.96 kJ mol(-1)), respectively. The effectiveness of the support vector machine (SVM) method in fitting large ab initio databases for MD calculations is investigated by using this method to fit the same HOOH database. The SVM fitting quality is tested by comparison to the NN fit. It is found that the average absolute and root-mean-squared testing set errors for the SVM fit are significantly larger than those obtained using NN methods. The total number of parameters in the SVM fit is more than a factor of 11 times the number of parameters in the NN fit. The trajectory computation time using a single NN averages about 1.8 s per picosecond of trajectory time. This increases to 9.0 s per picosecond of trajectory time if a five-NN committee is employed. The corresponding SVM computational time is almost 24 s per picosecond of trajectory time. Consequently, we conclude that a SVM is not as effective in fitting large databases for MD calculations as previously proposed methods, and thus is not employed to conduct MD studies. We employ the five-member NN committee to perform MD calculations at five different internal energies from 3.4 to 4.2 eV, including zero point energy. The rate coefficients are obtained directly from the first-order decay plots. They vary from 0.117 to 0.324 ps(-1). A Rice-Ramsperger-Kassel plot is found to exhibit good linearity. PMID:19586096

Le, Hung M; Huynh, Sau; Raff, Lionel M

2009-07-01

238

SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information. Part 2—Application to crosshole GPR tomography  

NASA Astrophysics Data System (ADS)

We present an application of the SIPPI Matlab toolbox, to obtain a sample from the a posteriori probability density function for the classical tomographic inversion problem. We consider a number of different forward models, linear and non-linear, such as ray based forward models that rely on the high frequency approximation of the wave-equation and 'fat' ray based forward models relying on finite frequency theory. In order to sample the a posteriori probability density function we make use of both least squares based inversion, for linear Gaussian inverse problems, and the extended Metropolis sampler, for non-linear non-Gaussian inverse problems. To illustrate the applicability of the SIPPI toolbox to a tomographic field data set we use a cross-borehole traveltime data set from Arrenæs, Denmark. Both the computer code and the data are released in the public domain using open source and open data licenses. The code has been developed to facilitate inversion of 2D and 3D travel time tomographic data using a wide range of possible a priori models and choices of forward models.

Hansen, Thomas Mejer; Cordua, Knud Skou; Looms, Majken Caroline; Mosegaard, Klaus

2013-03-01

239

Histories of Childhood Victimization and Subsequent Mental Health Problems, Substance Use, and Sexual Victimization for a Sample of Incarcerated Women in the US  

PubMed Central

Women are entering US prisons at nearly double the rate of men and are the fastest growing prison population. Current extant literature focuses on the prevalence of the incarceration of women, but few studies exist that emphasize the different trajectories to prison. For example, women prisoners have greater experiences of prior victimization, more reports of mental illness, and higher rates of illicit substance use. The purpose of this study was to understand the prevalence of childhood victimization and its association with adult mental health problems, substance abuse disorders, and further sexual victimization. The research team interviewed a random sample of 125 women prisoners soon to release from prison to gather information on their childhood physical and sexual victimization, mental health and substance abuse problems as an adult, and sexual victimization in the year preceding incarceration. Results indicate that women prisoners in this sample who were both physically and sexually victimized as a child were more likely to be hospitalized as an adult for a psychological or emotional problem. Women who were sexually victimized or both physically and sexually victimized were more likely to attempt suicide. Women who experienced physical victimization as children and women who were both physically and sexually victimized were more likely to have a substance use disorder and women who were sexually abused as children or both physically and sexually victimized were more likely to be sexually abused in the year preceding prison. This article ends with a discussion about prisons’ role in providing treatment for women prisoners and basing this treatment on women’s trajectories to prison, which disproportionately includes childhood victimization and subsequent mental health and substance use problems.

Tripodi, Stephen J.; Pettus-Davis, Carrie

2012-01-01

240

Histories of childhood victimization and subsequent mental health problems, substance use, and sexual victimization for a sample of incarcerated women in the US.  

PubMed

Women are entering US prisons at nearly double the rate of men and are the fastest growing prison population. Current extant literature focuses on the prevalence of the incarceration of women, but few studies exist that emphasize the different trajectories to prison. For example, women prisoners have greater experiences of prior victimization, more reports of mental illness, and higher rates of illicit substance use. The purpose of this study was to understand the prevalence of childhood victimization and its association with adult mental health problems, substance abuse disorders, and further sexual victimization. The research team interviewed a random sample of 125 women prisoners soon to be released from prison to gather information on their childhood physical and sexual victimization, mental health and substance abuse problems as an adult, and sexual victimization in the year preceding incarceration. Results indicate that women prisoners in this sample, who were both physically and sexually victimized as children, were more likely to be hospitalized as an adult for a psychological or emotional problem. Women who were sexually victimized or both physically and sexually victimized were more likely to attempt suicide. Women who experienced physical victimization as children and women who were both physically and sexually victimized were more likely to have a substance use disorder and women who were sexually abused as children or both physically and sexually victimized were more likely to be sexually abused in the year preceding prison. This article ends with a discussion about prisons' role in providing treatment for women prisoners and basing this treatment on women's trajectories to prison, which disproportionately include childhood victimization and subsequent mental health and substance use problems. PMID:23196054

Tripodi, Stephen J; Pettus-Davis, Carrie

2013-01-01

241

Prevalence of sexual problems in Portugal: results of a population-based study using a stratified sample of men aged 18 to 70 years.  

PubMed

Despite the use of different methodologies, target populations, and clinical definitions of sexual problems, recent epidemiological studies have shown that the occurrence of sexual difficulties is a very common experience among men from the general population regardless of their age. The objective of this study was to present epidemiological data on the prevalence of sexual difficulties in a community sample of 650 sexually active Portuguese men, stratified by age, marital status, and educational level. Participants completed a self-reported questionnaire assessing sexual function in the previous four weeks (International Index of Erectile Function). Results showed that sexual difficulties were relatively common among this sample. Rapid ejaculation was the most frequently reported sexual difficulty (23.2%), followed by erectile difficulties (10.2%), orgasm problems (8.2%), and low desire (2.9%) in the previous four weeks. With the exception of rapid ejaculation, all categories showed age-specific prevalence rates, with sexual difficulties increasing gradually in men above age 45. Age was a significant predictor of all sexual difficulties except rapid ejaculation, and lower educational levels were related to orgasm difficulties. Findings are consistent with the majority of epidemiological studies indicating a high prevalence of sexual difficulties among men in the general population and highlight the importance and the need to implement sexual health promotion programs in the target population. PMID:23573897

Quinta Gomes, Ana Luísa; Nobre, Pedro J

2014-01-01

242

Education: How Can Schools and Communities Work Together To Meet the Challenge? A Guide for Involving Community Members in Public Dialogue and Problem-Solving.  

ERIC Educational Resources Information Center

This guide is designed as a tool to help members of the education sector involve community members in discussions about their local schools and learn how to become involved in the process of improving education in their community. The first half of the guide presents basic material for conducting a four- to seven-session discussion program based…

Leighninger, Matthew; Niedergang, Mark

243

What are some of the cognitive, psychological, and social factors that facilitate or hinder licensed vocational nursing students' acquisition of problem-solving skills involved with medication-dosage calculations?  

NASA Astrophysics Data System (ADS)

The purpose of this study was to examine the cognitive and psychological factors that either enhanced or inhibited Licensed Vocational Nurse (LVN) students' abilities to solve medication-dosage calculation problems. A causal-comparative approach was adopted for use in this study which encompassed aspects of both qualitative and quantitative data collection. A purposive, maximum-variation sample of 20 LVN students was chosen from among a self-selected population of junior college LVN students. The participants' views and feelings concerning their training and clinical experiences in medication administration was explored using a semi-structured interview. In addition, data revealing the students' actual competence at solving sample medication-dosage calculation problems was gathered using a talk-aloud protocol. Results indicated that few participants anticipated difficulty with medication-dosage calculations, yet many participants reported being lost during much of the medication-dosage problem solving instruction in class. While many participants (65%) were able to solve the medication-dosage problems, some (35%) of the participants were unable to correctly solve the problems. Successful students usually spent time analyzing the problem and planning a solution path, and they tended to solve the problem faster than did unsuccessful participants. Successful participants relied on a formula or a proportional statement to solve the problem. They recognized conversion problems as a two-step process and solved the problems in that fashion. Unsuccessful participants often went directly from reading the problem statement to attempts at implementing vague plans. Some unsuccessful participants finished quickly because they just gave up. Others spent considerable time backtracking by rereading the problem and participating in aimless exploration of the problem space. When unsuccessful participants tried to use a formula or a proportion, they were unsure of the formula's or the proportion's format. A few unsuccessful participants lacked an understanding of basic algebraic procedures and of metric measurements. Even participants who had great difficulty solving medication-dosage calculation problems could expeditiously solve more complex problems if the medication used in the problem was well known to them.

Allen, Arthur William

244

Analysis of polyamines in biological samples by HPLC involving pre-column derivatization with o-phthalaldehyde and N-acetyl-L-cysteine.  

PubMed

Polyamines (putrescine, spermine and spermidine) play a crucial role in the regulation of cell growth, differentiation, death and function. Accurate measurement of these substances is essential for studying their metabolism in cells. This protocol describes detailed procedures for sample preparation and HPLC analysis of polyamines and related molecules (e.g., agmatine and cadaverine) in biological samples. The method is optimized for the deproteinization of samples, including biological fluids (e.g., 10 ?l), plant and animal tissues (e.g., 50 mg), and isolated/cultured cells (e.g., 1 × 10(6) cells). The in-line reaction of polyamines with o-phthalaldehyde and N-acetyl-L-cysteine yields fluorescent derivatives which are separated on a reversed-phase C18 column and detected by a fluorometer at an excitation wavelength of 340 nm and an emission wavelength of 450 nm. The total running time for each sample (including column regeneration on the automated system) is 30 min. The detection limit is 0.5 nmol/ml or 0.1 nmol/mg tissue in biological samples. The assays are linear between 1 and 50 ?M for each of the polyamines. The accuracy (the nearness of an experimental value to the true value) and precision (agreement between replicate measurement) of the HPLC method are 2.5-4.2 % and 0.5-1.4 %, respectively, for biological samples, depending on polyamine concentrations and sample type. Our HPLC method is highly sensitive, specific, accurate, easily automated, and capable for the analysis of samples with different characteristics and small volume/amount, and provides a useful research tool for studying the biochemistry, physiology, and pharmacology of polyamines and related substances. PMID:24633404

Dai, Zhaolai; Wu, Zhenlong; Wang, Junjun; Wang, Xiaoqiu; Jia, Sichao; Bazer, Fuller W; Wu, Guoyao

2014-06-01

245

A mesofluidic platform integrating on-chip probe ultrasonication for multiple sample pretreatment involving denaturation, reduction, and digestion in protein identification assays by mass spectrometry.  

PubMed

The integration of ultrasound (US)-assisted sample processing on-chip in a lab-on-a-valve (LOV) format for automated high-throughput shotgun proteomic assays is herein presented for the first time. The proof of concept of this system was demonstrated with the analysis of three proteins and sera from patients with lymphoma or myeloma. PMID:24443721

Nunes-Miranda, J D; Núñez, Cristina; Santos, Hugo M; Vale, G; Reboiro-Jato, Miguel; Fdez-Riverola, Florentino; Lodeiro, Carlos; Miró, Manuel; Capelo, J L

2014-03-01

246

On-line sample processing involving microextraction techniques as a front-end to atomic spectrometric detection for trace metal assays: a review.  

PubMed

Within the last decade, liquid-phase microextraction (LPME) and micro-solid phase extraction (?SPE) approaches have emerged as substitutes for conventional sample processing procedures for trace metal assays within the framework of green chemistry. This review surveys the progress of the state of the art in simplification and automation of microextraction approaches by harnessing to the various generations of flow injection (FI) as a front end to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS) or inductively coupled plasma atomic emission spectrometry or mass spectrometry (ICP-AES/MS). It highlights the evolution of flow injection analysis and related techniques as vehicles for appropriate sample presentation to the detector and expedient on-line matrix separation and pre-concentration of trace levels of metals in troublesome matrices. Rather than being comprehensive this review is aimed at outlining the pros and cons via representative examples of recent attempts in automating green sample preparation procedures in an FI or sequential injection (SI) mode capitalizing on single-drop microextraction, dispersive liquid-phase microextraction and advanced sorptive materials including carbon and metal oxide nanoparticles, ion imprinted polymers, superparamagnetic nanomaterials and biological/biomass sorbents. Current challenges in the field are identified and the synergetic combination of flow analysis, nanotechnology and metal-tagged biomolecule detection is envisaged. PMID:23708278

Miró, Manuel; Hansen, Elo Harald

2013-06-11

247

Epidemiological disaster research: the necessity to include representative samples of the involved disaster workers. Experience from the epidemiological study air disaster Amsterdam-ESADA  

PubMed Central

Objective To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. Design and Setting In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. Participants Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. Main results Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non?specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. Conclusions The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.

Huizink, Anja C; Smidt, Nynke; Twisk, Jos W R; Slottje, Pauline; Smid, Tjabe

2006-01-01

248

Ion beam studies of organometallic chemistry. High energy sampling of reaction intermediates involved in carbon-carbon bond cleavage by transition metals  

SciTech Connect

Chemical transformation often involves reactive intermediates which correspond to local minima on a complex potential energy surface. In this study of the reactions of cobalt ions with alkanes, the intermediate is provided more energy than needed for reaction. The quantitative assessment of the fragmentation of reaction intermediates provided thermodynamic data. These investigations involved organo transition metal reactions using ion beam technqiues. Results for the reaction of Co/sup +/ with 2-methylpropane and 2,2-dimethylpropane are included. The observation that the cross section for production of CoCH/sub 3//sup +/ is always greater than that of C/sub 3/H/sub 7/+ implies that IP(C/sub 0/CH/sub 3/) < IP(iso-C/sub 3/H/sub 7/) = 7.36 eV. A similar analysis of the 2,2-dimethylpropane system establishes IP(CoCH/sub 3/) > IP(tert-C/sub 4/H/sub 9/) = 6.70 eV. Measurement of the thresholds for the endothermic processes observed at high energies provides band energies of the products. Preliminary data for the endothermic reactions of Co/sup +/ with hydrogen and ethane indicate that D/sup 0/(Co/sup +/-H) = 52 +- 4 and D/sup 0/(Co -- CH/sub 3/) = 61 +- 4 kcal/mol. Combined with the ionization potentials, IP(CoH) = 7.3 +- 0.1 and IP(CoCH/sub 3/) = 7.0 +- 0.3 EV; we find the neutral band dissociation energies, D/sup 0/(CoH) = 39 +- 6 and D/sup 0/(CoCH/sub 3/) = 41 +- 10 kcal/mol. The results provide substantial evidence for the viability of a mechanism for carbon-carbon bond cleavage of alkanes which involves direct insertion of a metal into the carbon-carbon band as a first step. Thermochemical data indicating strong metal-carbon bonds corroborate this hypothesis. 2 figures. (DP)

Armentrout, P.B.; Beauchamp, J.L.

1980-02-27

249

[Survey of carbon fiber reinforced plastic orthoses and occupational and medical problems based on a questionnaire administered to companies involved in the manufacture of prosthetics and orthotics].  

PubMed

We surveyed carbon fiber reinforced plastic orthoses (carbon orthoses) and their associated occupational and medical problems based on a questionnaire sent to 310 companies which were members of the Japan Orthotics and Prosthetics Association. Of all the companies, 232 responded: 77 of the 232 companies dealt with ready-made carbon orthoses, 52 dealt with fabricated custom-made orthoses, and 155 did not dealt with carbon orthoses. Although the total number of custom-made carbon ortheses in Japan was 829/ 5 years, there was a difference by region, and one company fabricated only 12 (per 5 years) custom-made carbon orthoses on average. The advantages of the carbon orthosis were the fact that it was "light weight", "well-fitted", had a "good appearance", and "excellent durability", while the disadvantages were that it was "expensive", "high cost of production", of "black color", and required a "longer time for completion", and "higher fabrication techniques". From the standpoint of industrial medicine, "scattering of fine fragments of carbon fibers", "itching on the skin" and "health hazards" were indicated in companies that manufacture the orthosis. In order to make the carbon orthosis more popular, it is necessary to develop a new carbon material that is easier to fabricate at a lower cost, to improve the fabrication technique, and to resolve the occupational and medical problems. PMID:21913380

Kaneshiro, Yuko; Furuta, Nami; Makino, Kenichiro; Wada, Futoshi; Hachisuka, Kenji

2011-09-01

250

Some Insights into Analytical Bias Involved in the Application of Grab Sampling for Volatile Organic Compounds: A Case Study against Used Tedlar Bags  

PubMed Central

In this study, we have examined the patterns of VOCs released from used Tedlar bags that were once used for the collection under strong source activities. In this way, we attempted to account for the possible bias associated with the repetitive use of Tedlar bags. To this end, we selected the bags that were never heated. All of these target bags were used in ambient temperature (typically at or below 30°C). These bags were also dealt carefully to avoid any mechanical abrasion. This study will provide the essential information regarding the interaction between VOCs and Tedlar bag materials as a potential source of bias in bag sampling approaches.

Ghosh, Samik; Kim, Ki-Hyun; Sohn, Jong Ryeul

2011-01-01

251

Multiresidue determination of 256 pesticides in lavandin essential oil by LC/ESI/sSRM: advantages and drawbacks of a sampling method involving evaporation under nitrogen.  

PubMed

The determination of 256 multiclass pesticides in lavandin essential oil has been performed by liquid chromatography-electrospray ionization tandem mass spectrometry using the scheduled selected reaction monitoring mode available on a quadrupole-linear ion trap mass spectrometer. With the aim of improving the limits of quantification (LOQs) of the target molecules, a sampling step based on evaporation of the essential oil under a nitrogen flow assisted by controlled heating was tested. The LOQs determined in this case were compared with the values obtained with the classic dilution preparation method. With sampling by dilution, 247 pesticides were detected and quantified at low concentration, with 74 % of the pesticides having LOQs of 10 ?g L(-1) or less. With the evaporation method, a global improvement of the LOQs was observed, with lower LOQs for 92 active substances and LOQs of 10 ?g L(-1) or less for 82.8 % of the pesticides. Almost twice as many active substances had an LOQ of 1 ?g L(-1) or less when the evaporation method was used. Some pesticides exhibited poor recovery or high variance caused by volatilization or degradation during the evaporation step. This behavior was evidenced by the case of thiophanate-methyl, which is degraded to carbendazim. PMID:24366405

Fillâtre, Yoann; Rondeau, David; Daguin, Antoine; Jadas-Hecart, Alain; Communal, Pierre-Yves

2014-02-01

252

Volunteer Bias in Recruitment, Retention, and Blood Sample Donation in a Randomised Controlled Trial Involving Mothers and Their Children at Six Months and Two Years: A Longitudinal Analysis  

PubMed Central

Background The vulnerability of clinical trials to volunteer bias is under-reported. Volunteer bias is systematic error due to differences between those who choose to participate in studies and those who do not. Methods and Results This paper extends the applications of the concept of volunteer bias by using data from a trial of probiotic supplementation for childhood atopy in healthy dyads to explore 1) differences between a) trial participants and aggregated data from publicly available databases b) participants and non-participants as the trial progressed 2) impact on trial findings of weighting data according to deprivation (Townsend) fifths in the sample and target populations. 1) a) Recruits (n?=?454) were less deprived than the target population, matched for area of residence and delivery dates (n?=?6,893) (mean [SD] deprivation scores 0.09[4.21] and 0.79[4.08], t?=?3.44, df?=?511, p<0.001). b) i)As the trial progressed, representation of the most deprived decreased. These participants and smokers were less likely to be retained at 6 months (n?=?430[95%]) (OR 0.29,0.13–0.67 and 0.20,0.09–0.46), and 2 years (n?=?380[84%]) (aOR 0.68,0.50–0.93 and 0.55,0.28–1.09), and consent to infant blood sample donation (n?=?220[48%]) (aOR 0.72,0.57–0.92 and 0.43,0.22–0.83). ii)Mothers interested in probiotics or research or reporting infants’ adverse events or rashes were more likely to attend research clinics and consent to skin-prick testing. Mothers participating to help children were more likely to consent to infant blood sample donation. 2) In one trial outcome, atopic eczema, the intervention had a positive effect only in the over-represented, least deprived group. Here, data weighting attenuated risk reduction from 6.9%(0.9–13.1%) to 4.6%(?1.4–+10.5%), and OR from 0.40(0.18–0.91) to 0.56(0.26–1.21). Other findings were unchanged. Conclusions Potential for volunteer bias intensified during the trial, due to non-participation of the most deprived and smokers. However, these were not the only predictors of non-participation. Data weighting quantified volunteer bias and modified one important trial outcome. Trial Registration This randomised, double blind, parallel group, placebo controlled trial is registered with the International Standard Randomised Controlled Trials Register, Number (ISRCTN) 26287422. Registered title: Probiotics in the prevention of atopy in infants and children.

Jordan, Sue; Watkins, Alan; Storey, Mel; Allen, Steven J.; Brooks, Caroline J.; Garaiova, Iveta; Heaven, Martin L.; Jones, Ruth; Plummer, Sue F.; Russell, Ian T.; Thornton, Catherine A.; Morgan, Gareth

2013-01-01

253

Assessing expressed emotion: comparing Camberwell Family Interview and Five-minute Speech Sample ratings for mothers of children with behaviour problems.  

PubMed

Little is known of the concordance between ratings of expressed emotion (EE) derived from the Camberwell Family Interview (CFI) and Five-minute Speech Sample (FMSS) for parents of children with behaviour problems. Concordance between CFI and FMSS ratings of EE was assessed prior to intervention and compared to parent-rated behaviour after intervention, at follow-up, 12 months later. Female primary caretakers of 75 children (3-10 years) showing behavioural difficulties were interviewed using FMSS and CFI. Interviews were coded independently by criterion-standard raters. Using CFI, 57 families were classified high EE, and 18 low EE. Using FMSS, 65 families were classified high EE and 10 low EE. 55/75 pairs of ratings (73%) were the same (high, n = 51: low, n = 4) and 20 mothers (27%) were allocated different EE status (Kappa = 0.14, n.s.). The FMSS ratings at initial interview appeared more closely related to behaviour rating at follow-up than CFI. Further investigation is required to establish comparability of CFI and FMSS results for carers of children. PMID:17019895

Calam, R; Peters, S

2006-01-01

254

Gene expression profiling of systems involved in the metabolism and the disposition of xenobiotics: comparison between human intestinal biopsy samples and colon cell lines.  

PubMed

Intestinal cell lines are used as in vitro models for pharmacological and toxicological studies. However, a general report of the gene expression spectrum of proteins that are involved in the metabolism and the disposition of xenobiotics in these in vitro systems is not currently available. To fill this information gap, we systematically characterized the expression profile of 377 genes encoding xenobiotic-metabolizing enzymes, transporters, and nuclear receptors and transcription factors in intestinal mucosa (ileum, ascending colon, transverse colon, descending colon, and rectum) from five healthy subjects and in five commonly used intestinal cell lines (Caco-2, C2BBe1, HT29, T84, and FHC). For this, we performed a quantitative real-time reverse transcription-polymerase chain reaction analysis using TaqMan low-density arrays and analyzed the results by different statistical approaches: Spearman correlation coefficients, hierarchical clustering, and principal component analysis (PCA). A large variation in gene expression spectra was observed between intestinal cell lines and intestinal tissues. Both hierarchical clustering and PCA showed that two distinct clusters are visible, of which one corresponds to all cultured cell lines and the other to all intestinal biopsies. The best agreement between human tissue and the representative cell line was observed for human colonic tissues and HT29 and T84 cell lines. Altogether, these data demonstrated that gene expression profiling represents a new valuable tool for investigating in vitro and in vivo expression level correlation. This study has pointed out interesting expression profiles for various colon cell lines, which will be useful for choosing the appropriate in vitro model for pharmacological and toxicological studies. PMID:22217464

Bourgine, Joanna; Billaut-Laden, Ingrid; Happillon, Mélanie; Lo-Guidice, Jean-Marc; Maunoury, Vincent; Imbenotte, Michel; Broly, Franck

2012-04-01

255

Delinquency and Substance Use among Gang-Involved Youth: The Moderating Role of Parenting Practices  

Microsoft Academic Search

This study uses longitudinal data from an ethnically diverse sample of 300 ninth grade students to examine the moderating effect of parenting practices upon the relationship between gang involvement and adolescent problem behavior. Results of hierarchical linear modeling indicate that gang involvement is a highly significant positive predictor of each of three categories of problem behavior (minor delinquency, major delinquency,

Chanequa J. Walker-Barnes; Craig A. Mason

2004-01-01

256

Use of risk assessment instruments to predict violence and antisocial behaviour in 73 samples involving 24 827 people: systematic review and meta-analysis  

PubMed Central

Objective To investigate the predictive validity of tools commonly used to assess the risk of violence, sexual, and criminal behaviour. Design Systematic review and tabular meta-analysis of replication studies following PRISMA guidelines. Data sources PsycINFO, Embase, Medline, and United States Criminal Justice Reference Service Abstracts. Review methods We included replication studies from 1 January 1995 to 1 January 2011 if they provided contingency data for the offending outcome that the tools were designed to predict. We calculated the diagnostic odds ratio, sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, the number needed to detain to prevent one offence, as well as a novel performance indicator—the number safely discharged. We investigated potential sources of heterogeneity using metaregression and subgroup analyses. Results Risk assessments were conducted on 73 samples comprising 24?847 participants from 13 countries, of whom 5879 (23.7%) offended over an average of 49.6 months. When used to predict violent offending, risk assessment tools produced low to moderate positive predictive values (median 41%, interquartile range 27-60%) and higher negative predictive values (91%, 81-95%), and a corresponding median number needed to detain of 2 (2-4) and number safely discharged of 10 (4-18). Instruments designed to predict violent offending performed better than those aimed at predicting sexual or general crime. Conclusions Although risk assessment tools are widely used in clinical and criminal justice settings, their predictive accuracy varies depending on how they are used. They seem to identify low risk individuals with high levels of accuracy, but their use as sole determinants of detention, sentencing, and release is not supported by the current evidence. Further research is needed to examine their contribution to treatment and management.

2012-01-01

257

Different stability of social-communication problems and negative demanding behaviour from infancy to toddlerhood in a large Dutch population sample  

PubMed Central

Background Little is known about the stability of behavioural and developmental problems as children develop from infants to toddlers in the general population. Therefore, we investigated behavioural profiles at two time points and determined whether behaviours are stable during early development. Methods Parents of 4,237 children completed questionnaires with 62 items about externalizing, internalizing, and social-communicative behaviour when the children were 14–15 and 36–37 months old. Factor mixture modelling identified five homogeneous profiles at both time points: three with relatively normal behaviour or with mild/moderate problems, one with clear communication and interaction problems, and another with pronounced negative and demanding behaviour. Results More than 85% of infants with normal behaviour or mild problems at 14–15 months were reported to behave relatively typically as toddlers at 36–37 months. A similar percentage of infants with moderate communication problems outgrew their problems by the time they were toddlers. However, infants with severe problems had mild to severe problems as toddlers, and did not show completely normal behaviour. Improvement over time occurred more often in children with negative and demanding behaviour than in children with communication and interaction problems. The former showed less homotypic continuity than the latter. Conclusions Negative and demanding behaviour is more often transient and a less specific predictor of problems in toddlerhood than communication and interaction problems.

2014-01-01

258

A cross-sectional analysis of women's mental health problems: examining the association with different types of violence among a sample of Brazilian mothers  

PubMed Central

Background Mental health problems are the major cause of disability in poor countries, and women are the individuals most affected. The World Health Organization points out that violence against women is the leading cause of mental health problems. This study seeks to identify explanatory factors for women’s mental health problems, highlighting situations of violence suffered by them during childhood, when living with a partner and in the community. Method A cross-sectional analysis was conducted with 389 mothers with schoolchildren in a city in the state of Rio de Janeiro (Brazil). Profile variables and childhood and adult life experiences were researched and organized in three analytical blocks. A binary logistic regression model was used, divided into hierarchical blocks. Results The final model shows that women who were the victims of severe physical violence by their partner were more likely (OR?=?8.2) to suffer from mental health problems than those who had never been exposed to this type of violence. The mothers of children with behavior problems are more likely to have mental health problems (OR?=?3.0) than mothers whose children do not manifest behavioral problems. Conclusion This study shows that women’s mental health problems are particularly related to the experience of physical violence, especially that occurring in intimate partner relationships. Based on this premise, this work recommends that multidimensional issues need to be included in women’s health assistance programs duly incorporating the specificity of victimization by violence.

2013-01-01

259

Dual colour fluorescence in situ hybridization to paraffin-embedded samples to deduce the presence of the der(X)t(X;18)(p11.2;q11.2) and involvement of either the SSX1 or SSX2 gene: a diagnostic and prognostic aid for synovial sarcoma.  

PubMed

Identification of the t(X;18)(p11.2;q11.2) and the fusion gene products, SYT-SSX1 and SYT-SSX2, associated with a high proportion of synovial sarcomas, has been shown to be a useful diagnostic aid. This study demonstrates the application of dual colour fluorescence in situ hybridization to paraffin-embedded samples to deduce the presence of the derivative X chromosome and also the position of the breakpoint on chromosome X at either the SSX1 or the SSX2 gene. This used region specific markers from chromosomes X and 18 and an optimized protocol involving microwave exposure. Novel and rapid scoring criteria were validated which circumvented potential problems of nuclear truncation and defining cell boundaries. This involved blind analysis of two negative sarcoma samples and three synovial sarcomas in which corresponding frozen material had been previously shown to have the translocation involving different SSX genes. Six new cases diagnosed as synovial sarcoma were also analysed; two monophasic and two biphasic case were deduced to have a breakpoint in the SSX1 gene, one monophasic case an SSX2 breakpoint, and one case did not show rearrangement of the region. The ability to analyse formalin-fixed, paraffin-embedded samples in this way has practical implications for aiding the diagnosis of difficult cases, recently ascribed prognostic relevance, and allows further retrospective studies to be carried out. The methodology is also applicable to the identification of other tumour specific translocations in paraffin-embedded material. PMID:10398111

Lu, Y J; Birdsall, S; Summersgill, B; Smedley, D; Osin, P; Fisher, C; Shipley, J

1999-03-01

260

Work Samples.  

ERIC Educational Resources Information Center

Three work sample tasks--a logical contouring problem, a "pull-up" from an aerial photograph, and a geometric restitution task--for use in predicting job performance of the Cartographic Technician are provided. (For related documents, see TM 001 408, 463, 465, 466.) (DB)

Educational Testing Service, Princeton, NJ.

261

Geochemist's involvement with the pollution problem  

Microsoft Academic Search

Background levels of lead, zinc, nickel, chromium, copper, and manganese in soils and in four classes of vegetation have been estimated from collections that were made in remote areas presumed to be free from inorganic contamination. The trace-metal content of soils and plants varies widely in different geologic provinces of the US; in those areas of high natural mineralization, additions

H. L. Cannon; B. M. Anderson

1971-01-01

262

Two-stage sampling in surveys to substantiate freedom from disease  

Microsoft Academic Search

Disease in livestock populations tends to cluster at the herd level. In order to account for this—and to overcome the problems of simple random sampling from a very large population—large-scale livestock surveys usually involve two-stage sampling. However, the use of two-stage sampling presents particular problems for sample-size calculation and analysis. We developed a probability formula for two-stage sampling, initially based

Angus R. Cameron; F. Chris Baldock

1998-01-01

263

Problems & Issues.  

ERIC Educational Resources Information Center

Lists selected resources that help think about problems and issues and how they affect society in the areas of human health, social issues, and environmental issues. Includes Web sites, CD-ROMs and software, videos, books, magazines, and professional resources, with age levels and appropriate disciplines usually indicated. Suggests sample class…

Online-Offline, 2000

2000-01-01

264

[The problem of determining asbestos in bulk materials: a study of the effect of grinding on the diffractometric response of the chrysotile content in an asbestos cement sample].  

PubMed

To determine the asbestos content in a bulk sample by X-ray diffractometry, the sample must be previously comminuted until an adequate granulometry is reached. However, this treatment can produce a decrease in fibre crystallinity which, in turn, causes an attenuation of the diffractometric response of asbestos. The authors studied a "wet" comminution method that was tested on an asbestos-cement sample containing chrysotile. This procedure made it possible to limit the attenuation of the diffractometric response of chrysotile to reasonable values (about 20%). Moreover, the study of the comminution kinetics revealed a time interval during which both fibre granulometry and diffractometric response tend to reach a plateau value. In this interval, the comminution time is not a critical factor with respect to the diffractometric behaviour of chrysotile. Therefore, this interval offers favourable conditions for preparing bulk samples to be submitted to X-ray diffraction. PMID:8255261

Puledda, S; Paoletti, L

1993-01-01

265

An epidemiologic longitudinal study of sleeping problems and feeding experience of preterm and term children in southern Finland: Comparison with a southern German population sample  

Microsoft Academic Search

Objective: To determine the influence of breast-feeding on the prevalence and persistence of sleeping problems in southern Finland (SF) and southern Germany (SG). Design: Prospective binational population study of infants admitted to special care units (SCUs) in geographically defined areas in SF and SG. Subjects: In SF, the number of SCU infants was 1057 (very preterm, 47; preterm, 258; term,

Dieter Wolke; Brigitte Söhne; Klaus Riegel; Barbara Ohrt; Kalle Österlund

1998-01-01

266

Feature Selection with biased Sample Distributions  

Microsoft Academic Search

Feature selection concerns the problem of selecting a number of important features (w.r.t. the class labels) in order to build accurate prediction models. Traditional feature selection methods, however, fail to take the sample distributions into the consideration which may lead to poor predictions for minority class examples. Due to the sophistication and the cost involved in the data collection process,

Abu H. M. Kamal; Xingquan Zhu; Abhijit S. Pandya; Sam Hsu

2009-01-01

267

Clustering Based Under-Sampling for Improving Speaker Verification Decisions Using AdaBoost  

Microsoft Academic Search

\\u000a The class imbalance problem naturally occurs in some classification problems where the amount of training samples available\\u000a for one class may be much less than that of another. In order to deal with this problem, random sampling based methods are\\u000a generally used. This paper proposes a clustering based sampling technique to select a subset from the majority class involving\\u000a much

Hakan Altinçay; Cem Ergün

2004-01-01

268

Teacher Report of Children's Problem Behavior on The Sutter-Eyberg Student Behavior Inventory-Revised (SESBI-R) in a Norwegian Sample of Preschool and School Children  

ERIC Educational Resources Information Center

In the present study, the applicability of The Sutter-Eyberg Student Behavior Inventory-Revised (SESBI-R) was explored within a Norwegian sample of 983 children aged 3-8 years. By using an exploratory factor analysis the same 2-factor solution as the original SESBI-R was supported by Principal Component Analysis. Good internal consistency (alpha…

Kirkhaug, Bente; Drugli, May Britt; Morch, Willy-Tore; Handegard, Bjorn Helge

2012-01-01

269

Consumer Involvement in Rehabilitation.  

ERIC Educational Resources Information Center

A new approach to rehabilitation of the disabled and disadvantaged is necessary, but the problem of how to involve consumers and how to organize groups for community action is a big one. Moreover, citizen participation cannot be a substitute for basic improvement in the quality of service. Service agencies need to be decentralized and staff…

Thursz, Daniel

270

Common ophthalmic problems of urban and rural postmenopausal women in a population sample of Raciborz district, a RAC-OST-POL Study.  

PubMed

Introduction and objective. We wished to establish the prevalence of eye diseases and eye disease risk factors at postmenopausal age and to compare ophthalmic problems in urban and rural areas of Raciborz. Patients and methods. The study was performed in 2010. Out of the whole population of Raciborz, Poland, 10 percent (1750) of women were randomly selected for the reported study. Finally, ocular diseases, ophthalmic agents, health status (physical activity level, body mass index - BMI, reproductive history, the use of psychotropic drugs and hormone replacement therapy - HRT) were recorded in 623 women. The women underwent visual acuity test and anterior segment examination, applanation tonometry and indirect ophthalmoscopy. Results. The mean age of the selected patients was 66.01±7.76 years, 275 (44%) of them originating from rural and 348 (56%) from urban regions. The average woman was obese (BMI=30.54±5.38 kg/m2), with near normal agility and reproductive history of 2.59±1.55 births, 147 (24%) subjects remained under regular HRT support. According to the WHO, the visual acuity was classified as normal or near normal in 87.5%, while no blindness was recorded at all. Visual acuity depended, first of all, on lens status and was better among subjects with good agility (R=-0.31, p=0.001). Dry eye prevalence increased significantly over age of 67 years (p=0.000) and HRT seemed to be a dry eye protective factor (p=0.010). Except age, No other risk factors of cataract, other than age, were identified. Normal agility (p=0.003) and HRT (p=0.032) were associated with lower AMD (age-related macular degeneration) prevalence rates. The differences between urban and rural participants were presented only in education, reproductive history, hypertension and frequency of ophthalmic examinations. Conclusions. Older adult women living in neighboring urban and rural areas present no differential in ophthalmic health problems. PMID:24738500

Rokicki, Wojciech; Drozdzowska, Bogna; Czekaj?o, Aleksandra; Grzeszczak, W?adys?aw; Karpe, Jacek; Wiktor, Katarzyna; Pluskiewicz, Wojciech

2014-03-31

271

Youth Maltreatment and Gang Involvement  

Microsoft Academic Search

Although childhood maltreatment has been found to contribute to a variety of youth problem behaviors, the implications of being maltreated on gang involvement remain unclear. This research examines whether physical and sexual maltreatment raises the risk of gang involvement among secondary school students. Findings show that being maltreated increases the probability of gang involvement, independent of demographic factors. When youth

KEVIN M. THOMPSON; RHONDA BRAATEN-ANTRIM

1998-01-01

272

Does the Association with Psychosomatic Health Problems Differ between Cyberbullying and Traditional Bullying?  

ERIC Educational Resources Information Center

The association between mental health problems and traditional bullying is well known, whereas the strength of the association in cyberbullying is less known. This study aimed to compare the association between mutually exclusive groups of bullying involvement and psychosomatic problems as measured by the PsychoSomatic Problems scale. The sample

Beckman, Linda; Hagquist, Curt; Hellstrom, Lisa

2012-01-01

273

Comparison of derivative-free optimization methods for groundwater supply and hydraulic capture community problems  

Microsoft Academic Search

Management decisions involving groundwater supply and remediation often rely on optimization techniques to determine an effective strategy. We introduce several derivative-free sampling methods for solving constrained optimization problems that have not yet been considered in this field, and we include a genetic algorithm for completeness. Two well-documented community problems are used for illustration purposes: a groundwater supply problem and a

K. R. Fowler; J. P. Reese; C. E. Kees; J. E. Dennis; C. T. Kelley; C. T. Miller; C. Audet; A. J. Booker; G. Couture; R. W. Darwin; M. W. Farthing; D. E. Finkel; J. M. Gablonsky; G. Gray; T. G. Kolda

2008-01-01

274

Statistical distribution sampling  

NASA Technical Reports Server (NTRS)

Determining the distribution of statistics by sampling was investigated. Characteristic functions, the quadratic regression problem, and the differential equations for the characteristic functions are analyzed.

Johnson, E. S.

1975-01-01

275

Conversion Word Problems  

NSDL National Science Digital Library

This ready-to-print work sheet presents students with three problems, and in order to solve them, students must convert between smaller and larger units and use all four mathematical operations. There are a total of seven questions involving these three problems, and the conversions which students must undertake involve dollars and cents, pounds and ounces, grams and kilograms, and centimeters and meters.

Molik, Nancy

2004-01-01

276

Sampling SIM: Sampling Distributions  

NSDL National Science Digital Library

Created by authors Beth Chance, Bob delMas and Joan Garfield, this webpage provides instructions for teaching sampling distributions using Sampling SIM software. It includes information regarding prerequisite knowledge, common misconceptions, and objectives, as well as links to an activity and a pre/post-test. This is a fairly comprehensive overview of the tools need for sampling distributions. The eight part structure employed by the authors is quite useful in assessing students knowledge gained through this activity.

Chance, Beth; Delmas, Bob; Garfield, Joan

2009-03-16

277

Atmospheric Sciences: Problems and Applications.  

National Technical Information Service (NTIS)

This report attempts to summarize the types of problems that are encountered in atmospheric research and to show why such problems are indeed scientific problems of an involved and complex nature, yet, for the most part, solvable, providing sufficient att...

1977-01-01

278

Reverse mapping of normal tissue complication probabilities onto dose volume histogram space: The problem of randomness of the dose volume histogram sampling  

SciTech Connect

A very important issue in contemporary inverse treatment radiotherapy planning is the specification of proper dose-volume constraints limiting the treatment planning algorithm from delivering high doses to the normal tissue surrounding the tumor. Recently we have proposed a method called reverse mapping of normal tissue complication probabilities (NTCP) onto dose-volume histogram (DVH) space, which allows the calculation of appropriate biologically based dose-volume constraints to be used in the inverse treatment planning. The method of reverse mapping requires random sampling from the functional space of all monotonically decreasing functions in the unit square. We develop, in this paper, a random function generator for the purpose of the reverse mapping. Since the proposed generator is based on the theory of random walk, it is therefore designated in this work, as a random walk DVH generator. It is theoretically determined that the distribution of the number of monotonically decreasing functions passing through a point in the dose volume histogram space follows the hypergeometric distribution. The proposed random walk DVH generator thus simulates, in a random fashion, trajectories of monotonically decreasing functions (finite series) that are situated in the unit square [0,1]x[1,0] using the hypergeometric distribution. The DVH generator is an important tool in the study of reverse NTCP mapping for the calculation of biologically based dose-volume constraints for inverse treatment planning.

Markov, Krassimir; Schinkel, Colleen; Stavreva, Nadia; Stavrev, Pavel; Weldon, Michael; Fallone, B. Gino [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada); Department of Physics, University of Alberta, and Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada); Department of Physics, University of Alberta, and Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada); Departments of Physics and Oncology, University of Alberta, and Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, T6G1Z2 (Canada)

2006-09-15

279

Reverse mapping of normal tissue complication probabilities onto dose volume histogram space: the problem of randomness of the dose volume histogram sampling.  

PubMed

A very important issue in contemporary inverse treatment radiotherapy planning is the specification of proper dose-volume constraints limiting the treatment planning algorithm from delivering high doses to the normal tissue surrounding the tumor. Recently we have proposed a method called reverse mapping of normal tissue complication probabilities (NTCP) onto dose-volume histogram (DVH) space, which allows the calculation of appropriate biologically based dose-volume constraints to be used in the inverse treatment planning. The method of reverse mapping requires random sampling from the functional space of all monotonically decreasing functions in the unit square. We develop, in this paper, a random function generator for the purpose of the reverse mapping. Since the proposed generator is based on the theory of random walk, it is therefore designated in this work, as a random walk DVH generator. It is theoretically determined that the distribution of the number of monotonically decreasing functions passing through a point in the dose volume histogram space follows the hypergeometric distribution. The proposed random walk DVH generator thus simulates, in a random fashion, trajectories of monotonically decreasing functions (finite series) that are situated in the unit square [0, 1] X [1,0] using the hypergeometric distribution. The DVH generator is an important tool in the study of reverse NTCP mapping for the calculation of biologically based dose-volume constraints for inverse treatment planning. PMID:17022240

Markov, Krassimir; Schinkel, Colleen; Stavreva, Nadia; Stavrev, Pavel; Weldon, Michael; Fallone, B Gino

2006-09-01

280

Redox spectrophotometric method involving electrolytically generated manganese(III) sulphate with diphenylamine for the determination of ascorbic acid present in the samples of various fruits, commercial juices and sprouted food grains.  

PubMed

A spectrophotometric method was developed for ascorbic acid present in various fruits, commercial fruit juices and sprouted food grains. The method involves the oxidation of ascorbic acid with excess manganese(III) following reduction of unreacted manganese(III) with diphenylamine or barium diphenylamine sulphonate forming a product ?(max) 570 nm the system 1 or 540 nm the system 2 and decrease in the colour intensity is proportional to the concentration of vitamin C with quantification range 0.3-3.0 ?g ml(-1). The molar absorptivity and Sandell's sensitivity values of the system 1 and the system 2 were 1.829 × 10(4) and 1.813 × 10(4)mol(-1)cm(-1) and 0.0096 and 0.0097 ?g cm(-2) respectively. The stoichiometry was 4:1 between manganese(III) and diphenylamine. The ascorbic acid contents of the same samples were determined separately following the procedures of the developed method as well as the reference method and the results were comparable. PMID:23411340

Shyla, B; Nagendrappa, G

2013-06-01

281

Today's Traveling Salesman Problem  

Microsoft Academic Search

Heterogeneous unmanned aerial vehicles (UAVs) are being developed for several civil and military applications. These vehicles can differ either in their motion constraints or sensing\\/attack capabilities. This article uses methods from operations research to address a fundamental routing problem involving heterogeneous UAVs. The approach is to transform the routing problem into a relatively better understood single, asymmetric, traveling salesman problem

PAUL OBERLIN; SIVAKUMAR RATHINAM; SWAROOP DARBHA

2010-01-01

282

Problem? What Problem?  

ERIC Educational Resources Information Center

Successive administrations have responded to the serious shortage of competent mathematics teachers by trying to 'make do', adopting short-term strategies which fail to address the underlying problem. A sense of urgency, the will to act, and the imagination to see a way forward have been absent. The situation is now worse than ever. This paper…

Gardiner, Tony

283

Balance Problems  

MedlinePLUS

... it could be a sign of a balance problem. Balance problems can make you feel unsteady or as if ... related injuries, such as hip fracture. Some balance problems are due to problems in the inner ear. ...

284

Sampling from Spatial Databases  

Microsoft Academic Search

Techniques for obtaining random point samples from spatial databases are described. Random points are sought from a continuous domain that satisfy a spatial predicate which is represented in the database as a collection of polygons. Several applications of spatial sampling are described. Sampling problems are characterized in terms of two key parameters: coverage (selectivity), and expected stabbing number (overlap). Two

Frank Olken; Doron Rotem

1993-01-01

285

Test Problems for Hydrocodes.  

National Technical Information Service (NTIS)

A collection of exact solutions to the inviscid (Euler) equations of motion is presented for use in testing finite-difference calculations. The emphasis is on problems involving solid explosives and inerts. (ERA citation 06:019162)

W. Fickett W. C. Rivard

1981-01-01

286

Fast mixing hyperdynamic sampling  

Microsoft Academic Search

Sequential random sampling ('Markov Chain Monte-Carlo') is a popular strategy for many vision prob- lems involving multimodal distributions over high-dimensional parameter spaces. It applies both to impor- tance sampling (where one wants to sample points according to their 'importance' for some calculation, but otherwise fairly) and to global optimization (where one wants to find good minima, or at least good

Cristian Sminchisescu; Bill Triggs

2006-01-01

287

Stoke's Law Problem Set  

NSDL National Science Digital Library

This is a problem set that involves the calculation of velocities from a Reynolds number, determination of Stoke's Law applicability, and calculation of settling velocities for a variety of grain sizes and materials. This can be used in conjunction with a lab but is itself just a problem set.

Headley, Rachel

288

Driver scheduling problem modelling  

Microsoft Academic Search

The Drivers Scheduling Problem (DSP) consists of selecting a set of duties for vehicle drivers, for example buses, trains, plane or boat drivers or pilots, for the transportation of passengers or goods. This is a complex problem because it involves several constraints related to labour and company rules and can also present different evaluation criteria and objectives. Being able to

Rita Portugal; Helena Ramalhinho-Lourenço; José P. Paixao

2006-01-01

289

California's Water Problems.  

ERIC Educational Resources Information Center

This packet of instructional materials is designed to give social science students in grades 6-9 a first-hand experience in working out solutions to real-life problems involving the management of California's water. Students work in groups on one of three problems presented in the packet: (1) the management of the Sacramento-San Joaquin Delta that…

Wheatley, Judy; Sudman, Rita Schmidt, Ed.

290

Musculoskeletal involvement in sarcoidosis*, **  

PubMed Central

Sarcoidosis is a multisystem inflammatory disorder of unknown cause. It most commonly affects the pulmonary system but can also affect the musculoskeletal system, albeit less frequently. In patients with sarcoidosis, rheumatic involvement is polymorphic. It can be the presenting symptom of the disease or can appear during its progression. Articular involvement is dominated by nonspecific arthralgia, polyarthritis, and Löfgren's syndrome, which is defined as the presence of lung adenopathy, arthralgia (or arthritis), and erythema nodosum. Skeletal manifestations, especially dactylitis, appear mainly as complications of chronic, multiorgan sarcoidosis. Muscle involvement in sarcoidosis is rare and usually asymptomatic. The diagnosis of rheumatic sarcoidosis is based on X-ray findings and magnetic resonance imaging findings, although the definitive diagnosis is made by anatomopathological study of biopsy samples. Musculoskeletal involvement in sarcoidosis is generally relieved with nonsteroidal anti-inflammatory drugs or corticosteroids. In corticosteroid-resistant or -dependent forms of the disease, immunosuppressive therapy, such as treatment with methotrexate or anti-TNF-?, is employed. The aim of this review was to present an overview of the various types of osteoarticular and muscle involvement in sarcoidosis, focusing on their diagnosis and management.

Nessrine, Akasbi; Zahra, Abourazzak Fatima; Taoufik, Harzy

2014-01-01

291

Musculoskeletal involvement in sarcoidosis.  

PubMed

Sarcoidosis is a multisystem inflammatory disorder of unknown cause. It most commonly affects the pulmonary system but can also affect the musculoskeletal system, albeit less frequently. In patients with sarcoidosis, rheumatic involvement is polymorphic. It can be the presenting symptom of the disease or can appear during its progression. Articular involvement is dominated by nonspecific arthralgia, polyarthritis, and Löfgren's syndrome, which is defined as the presence of lung adenopathy, arthralgia (or arthritis), and erythema nodosum. Skeletal manifestations, especially dactylitis, appear mainly as complications of chronic, multiorgan sarcoidosis. Muscle involvement in sarcoidosis is rare and usually asymptomatic. The diagnosis of rheumatic sarcoidosis is based on X-ray findings and magnetic resonance imaging findings, although the definitive diagnosis is made by anatomopathological study of biopsy samples. Musculoskeletal involvement in sarcoidosis is generally relieved with nonsteroidal anti-inflammatory drugs or corticosteroids. In corticosteroid-resistant or -dependent forms of the disease, immunosuppressive therapy, such as treatment with methotrexate or anti-TNF-?, is employed. The aim of this review was to present an overview of the various types of osteoarticular and muscle involvement in sarcoidosis, focusing on their diagnosis and management. PMID:24831403

Nessrine, Akasbi; Zahra, Abourazzak Fatima; Taoufik, Harzy

2014-04-01

292

Recognizing Problems in State Universities.  

ERIC Educational Resources Information Center

Recognizing problems in state universities involves a critical analysis of both internal and external environments, as well as a simplification of the complex factors to help people understand the problems and marshall the forces necessary to address them. (MSE)

Ping, Charles J.

1986-01-01

293

Problem Solving: Tips for Teachers.  

ERIC Educational Resources Information Center

Presents several suggestions for teaching problem-solving. They include: (1) using the "reduction" strategy (which permits students to solve problems involving a large number of cases or a very complex figure); (2) a problem for students in grades 4-8 to solve; and (3) ways of fostering a problem-solving climate. (JN)

Krulik, Stephen; Rudnick, Jesse A.

1985-01-01

294

Problems and methods of psychophysics  

Microsoft Academic Search

The problems of psychophysics primarily involve scale construction. Each of the 5 types of scaling problems are outlined, i.e., the determination of nominal scales, ordinal scales, interval scales, logarithmic interval scales, and ratio scales, along with a description of the methodology appropriate to each problem. The applications of psychophysical methodology to problems of practical utility are briefly described.

S. S. Stevens

1958-01-01

295

Selection Sample Size Approximations.  

National Technical Information Service (NTIS)

Two conservative sample size approximations are given for the Bechhofer formulation of the problem of selecting the population with the largest mean, when the populations have a common known variance. A table of numerical comparisons of these approximatio...

J. S. Ramberg

1972-01-01

296

Protective Factors Associated with Fewer Multiple Problem Behaviors among Homeless/Runaway Youth  

ERIC Educational Resources Information Center

Although homeless youth exhibit numerous problem behaviors, protective factors that can be targeted and modified by prevention programs to decrease the likelihood of involvement in risky behaviors are less apparent. The current study tested a model of protective factors for multiple problem behavior in a sample of 474 homeless youth (42% girls;…

Lightfoot, Marguerita; Stein, Judith A.; Tevendale, Heather; Preston, Kathleen

2011-01-01

297

Depression, Conduct Problems and Substance Abuse Treatment Outcomes among Adolescents  

Microsoft Academic Search

The purpose of this dissertation study was to investigate the direct and interactive relationships between depression and conduct problems and substance abuse treatment outcomes in a national sample of adolescents participating in substance abuse treatment. This study involved a secondary analysis of data from the National Institute on Drug Abuse's- Drug Abuse Treatment Outcome Study for Adolescence (DATOS-A), a multi-site,

Marcel Alejandro de Dios

2007-01-01

298

Knee Problems  

MedlinePLUS

... here for a list of all articles Knee Problems Knee Problems Diseases and Conditions Broken Bones Injuries ... parts, many different things can go wrong. Common Problems Fast Find H as your doctor given you ...

299

Childbirth Problems  

MedlinePLUS

... labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with the position of the baby, such as ... feet first Birth injuries For some of these problems, the baby may need to be delivered surgically ...

300

Complexity of the simplest phylogenetic estimation problem.  

PubMed Central

The maximum-likelihood (ML) solution to a simple phylogenetic estimation problem is obtained analytically The problem is estimation of the rooted tree for three species using binary characters with a symmetrical rate of substitution under the molecular clock. ML estimates of branch lengths and log-likelihood scores are obtained analytically for each of the three rooted binary trees. Estimation of the tree topology is equivalent to partitioning the sample space (space of possible data outcomes) into subspaces, within each of which one of the three binary trees is the ML tree. Distance-based least squares and parsimony-like methods produce essentially the same estimate of the tree topology, although differences exist among methods even under this simple model. This seems to be the simplest case, but has many of the conceptual and statistical complexities involved in phylogeny estimation. The solution to this real phylogeny estimation problem will be useful for studying the problem of significance evaluation.

Yang, Z

2000-01-01

301

Finite Sampling Models  

NSDL National Science Digital Library

Created by Kyle Siegrist of the University of Alabama-Huntsville, this is an online, interactive lesson on finite sampling models. The lesson provides examples, exercises, and applets that include hypergeometric distribution, multivariate hypergeometric distribution, order statistics, the matching problem, the birthday problem, and the coupon collector problem. This is the twelfth of seventeen different lessons created by Siegrist. This site is structured much like an online textbook.

Siegrist, Kyle

2009-02-27

302

Improved Sample Size Determination for Attributes and Variables Sampling.  

National Technical Information Service (NTIS)

Earlier INMM papers have addressed the attributes/variables problem and, under conservative/limiting approximations, have reported analytical solutions for the attributes and variables sample sizes. Through computer simulation of this problem, we have cal...

D. Stirpe R. R. Picard

1985-01-01

303

A model for routing problem in quay management problem  

NASA Astrophysics Data System (ADS)

Quadratic Assignment Problem (QAP), like Vehicle Routing Problem, is one of those optimization problems that interests many researchers in the last decades. The Quay Management Problem is a specific problem which could be presented as a QAP which involves a double assignment of customers and products toward loading positions using lifting trucks. This study focuses on the routing problem while delivering the customers' demands. In this problem, lifting trucks will route around the storage sections to collect the products then deliver to the customers who are assigned to specific loading positions. The objective of minimizing the residence time for each customer is sought. This paper presents the problem and the proposed model.

Zirour, Mourad; Oughalime, Ahmed; Liong, Choong-Yeun; Ismail, Wan Rosmanira; Omar, Khairuddin

2014-06-01

304

A Comparison of Some K-Sample Nonparametric Tests for Scale.  

ERIC Educational Resources Information Center

Four nonparametric alternatives to the parametric Bartlett test are presented for handling the K-sample equality of variance problem. The two sample Siegel-Tukey Test, Mood Coefficient of Alienation Test, and Klotz Test are extended to the multisample situation by the methods of Puri. A fourth alternative involving a Q-statistic procedure…

Penfield, Douglas A.; Koffler, Stephen L.

305

Execution of Multidisciplinary Design Optimization Approaches on Common Test Problems  

NASA Technical Reports Server (NTRS)

A class of synthetic problems for testing multidisciplinary design optimization (MDO) approaches is presented. These test problems are easy to reproduce because all functions are given as closed-form mathematical expressions. They are constructed in such a way that the optimal value of all variables and the objective is unity. The test problems involve three disciplines and allow the user to specify the number of design variables, state variables, coupling functions, design constraints, controlling design constraints, and the strength of coupling. Several MDO approaches were executed on two sample synthetic test problems. These approaches included single-level optimization approaches, collaborative optimization approaches, and concurrent subspace optimization approaches. Execution results are presented, and the robustness and efficiency of these approaches an evaluated for these sample problems.

Balling, R. J.; Wilkinson, C. A.

1997-01-01

306

Aliasing-Point Sampling Theory  

NSDL National Science Digital Library

A qualitative introduction to point sampling theory and how it applies to the problem of aliasing in computer graphics and some solutions to the problem. There are only images and html pages in this section.

2007-01-20

307

Sampling Error  

NSDL National Science Digital Library

This one page article, created by Statistics Canada, describes the meaning behind random sampling error. It points our the relationship of the random sampling error with the sample size, population size, variability of the characteristic, sampling plan, and measuring sampling error. While brief, this provides valuable information and also links users to additional resources concerning statistics.

2009-01-07

308

IMAGE: Weekly Problem Archive  

NSDL National Science Digital Library

This is the Image for Magnetopause-to-Auroral Global Exploration (IMAGE) archive of weekly math, science, reading and art problems. New problems involving near-Earth space technology are emailed to participating teachers each week on Tuesday. The problems can be used in related lessons or as extra credit assignments. This web page is part of the outreach program of the IMAGE Satellite team to give teachers and students the latest information about aurora and the study of Earth's magnetic field, along with many programs that IMAGE has developed or participated in with NASA. A pdf document of extra credit problems is also available at this site.

Odenwald, Sten

309

Capillary sample  

MedlinePLUS

... in the diagnosis of medical conditions. Capillary blood sampling offers several advantages over drawing blood from a ... sugar several times a day using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a ...

310

An Optimization-Based Sampling Scheme for Phylogenetic Trees  

NASA Astrophysics Data System (ADS)

Much modern work in phylogenetics depends on statistical sampling approaches to phylogeny construction to estimate probability distributions of possible trees for any given input data set. Our theoretical understanding of sampling approaches to phylogenetics remains far less developed than that for optimization approaches, however, particularly with regard to the number of sampling steps needed to produce accurate samples of tree partition functions. Despite the many advantages in principle of being able to sample trees from sophisticated probabilistic models, we have little theoretical basis for concluding that the prevailing sampling approaches do in fact yield accurate samples from those models within realistic numbers of steps. We propose a novel approach to phylogenetic sampling intended to be both efficient in practice and more amenable to theoretical analysis than the prevailing methods. The method depends on replacing the standard tree rearrangement moves with an alternative Markov model in which one solves a theoretically hard but practically tractable optimization problem on each step of sampling. The resulting method can be applied to a broad range of standard probability models, yielding practical algorithms for efficient sampling and rigorous proofs of accurate sampling for some important special cases. We demonstrate the efficiency and versatility of the method in an analysis of uncertainty in tree inference over varying input sizes. In addition to providing a new practical method for phylogenetic sampling, the technique is likely to prove applicable to many similar problems involving sampling over combinatorial objects weighted by a likelihood model.

Misra, Navodit; Blelloch, Guy; Ravi, R.; Schwartz, Russell

311

Sampling the Ocean Floor  

NSDL National Science Digital Library

In this lesson, students take samples from an unseen model of the ocean floor and try to accurately describe its composition. It will introduce the students to the limitations of sampling and the problem of obtaining representative samples of sea floor sediments. The lesson can also be an introduction to a study of geological oceanography or local geology. Younger children can use symbols or icons to keep track of the different sediment types as they sample, and make graphs of the total numbers of each type of sediment. Older students can compute percentages and compare the accuracy of each sample group to the actual composition of the ocean floor.

312

Microbiological surface sampling cart  

NASA Technical Reports Server (NTRS)

Mobile sampling cart automatically swabs surfaces for the recovery of microorganisms. Unit operates without human involvement and provides for control of swabbing speed, rotation of cotton swab, and the pressure and angle applied to swab. Capability of reverse direction is also available. Sampling cart use is limited to flat surfaces.

Wilkins, J. R.; Mills, S. M.

1972-01-01

313

National Sample Assessment Protocols  

ERIC Educational Resources Information Center

These protocols represent a working guide for planning and implementing national sample assessments in connection with the national Key Performance Measures (KPMs). The protocols are intended for agencies involved in planning or conducting national sample assessments and personnel responsible for administering associated tenders or contracts,…

Ministerial Council on Education, Employment, Training and Youth Affairs (NJ1), 2012

2012-01-01

314

Judgment by Sampling (2)  

NSDL National Science Digital Library

This article, created by A.F. Bissell of Abergavenny, follows Judgment by Sampling (1), in which the author analyzes a quality control problem. This paper presents the operating characteristic curve for the sampling plan devised in the first article. This is a brief lesson, but it still introduces many concepts pertinent to both statistical testing and sampling. The precursor to this lesson is available at this location:http://www.rsscse.org.uk/ts/bts/bissell1/text.html

Bissell, A. F.

2011-06-20

315

Problem drinkers and their problems  

PubMed Central

From general practice records of 9,763 patients, 106 problem drinkers were compared with a control group. The drinkers had a substantially higher number of problems and they consulted their doctor and attended casualty departments frequently. Social and marital problems were especially prevalent in the families of problem drinkers.

Buchan, I. C.; Buckley, E. G.; Deacon, G. L. S.; Irvine, R.; Ryan, M. P.

1981-01-01

316

Personality, Perceived Luck and Gambling Attitudes as Predictors of Gambling Involvement  

Microsoft Academic Search

A quantitative observational study was undertaken to examine the relationship between individual factors and level of gambling\\u000a involvement, in particular problem gambling (PG). The specific factors under study were personality, perceived luck, and attitudes\\u000a towards gambling. A sample of university students (N = 185) completed a battery of questionnaires, consisting of the 16PF, Canadian Problem Gambling Index, Belief in Good Luck\\u000a Scale

Jamie Chiu; Lance Storm

2010-01-01

317

Delinquency and substance use among gang-involved youth: the moderating role of parenting practices.  

PubMed

This study uses longitudinal data from an ethnically diverse sample of 300 ninth grade students to examine the moderating effect of parenting practices upon the relationship between gang involvement and adolescent problem behavior. Results of hierarchical linear modeling indicate that gang involvement is a highly significant positive predictor of each of three categories of problem behavior (minor delinquency, major delinquency, and substance use). Three of the four parenting variables (behavioral control, psychological control, parent-adolescent conflict, and warmth) are found to moderate the relationship between gang involvement and problem behavior, with the most consistent effects found for behavioral control and warmth. These findings indicate that intervention efforts aimed at reducing the impact of gang involvement on adolescent development should consider factors that may decrease the deleterious behavioral outcomes associated with youth gangs. PMID:15663209

Walker-Barnes, Chanequa J; Mason, Craig A

2004-12-01

318

Organized Activity Involvement among Rural Youth: Gender Differences in Associations between Activity Type and Developmental Outcomes  

ERIC Educational Resources Information Center

The current study examined associations between organized activity involvement, academic achievement, and problem behavior in a sample of youth from a non-agricultural based rural community (M[subscript age] = 15.26, Age range = 11-19 years, N = 456). Analyses examined whether associations varied as a function of adolescent gender and age.…

Ferris, Kaitlyn A.; Oosterhoff, Benjamin; Metzger, Aaron

2013-01-01

319

Nonprobability Sampling  

NSDL National Science Digital Library

This site, created by author William M.K. Trochim, describes numerous methods of nonprobability sampling, including accidental, haphazard or convenience sampling and many other types of purposive methods. Some of these purposive methods he describes are: modal instance, expert, quota, heterogeneity, and snowball sampling. Overall, this is a good, albeit brief, overview of the subject of nonprobability sampling.

Trochim, William M.

2008-12-12

320

Snowball Sampling  

Microsoft Academic Search

An $s$ stage $k$ name snowball sampling procedure is defined as follows: A random sample of individuals is drawn from a given finite population. (The kind of random sample will be discussed later in this section.) Each individual in the sample is asked to name $k$ different individuals in the population, where $k$ is a specified integer; for example, each

Leo A. Goodman

1961-01-01

321

Validation and use of a fast sample preparation method and liquid chromatography-tandem mass spectrometry in analysis of ultra-trace levels of 98 organophosphorus pesticide and carbamate residues in a total diet study involving diversified food types.  

PubMed

This paper reports a comprehensive sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, identification and quantitation of 73 pesticides and their related products, a total of 98 analytes, belonging to organophosphorus pesticides (OPPs) and carbamates, in foods. The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) procedure that combines isolation of the pesticides and sample clean-up in a single step. Analysis is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Two main fragment ions for each pesticide were obtained to achieve the identification according to the SANCO guidelines 10684/2009. The method was validated with various food samples, including edible oil, meat, egg, cheese, chocolate, coffee, rice, tree nuts, citric fruits, vegetables, etc. No significant matrix effect was observed for tested pesticides, therefore, matrix-matched calibration was not necessary. Calibration curves were linear and covered from 1 to 20 microg L(-1) for all compounds studied. The average recoveries, measured at 10 microg kg(-1), were in the range 70-120% for all of the compounds tested with relative standard deviations below 20%, while a value of 10 microg kg(-1) has been established as the method limit of quantitation (MLOQ) for all target analytes. Similar trueness and precision results were also obtained for spiking at 200 microg kg(-1). Expanded uncertainty values were in the range 21-27% while the HorRat ratios were below 1. The method has been successfully applied to the analysis of 700 food samples in the course of a baseline monitoring study of OPPs and carbamates. PMID:20557892

Chung, Stephen W C; Chan, Benny T P

2010-07-16

322

Breathing Problems  

MedlinePLUS

... you're not getting enough air. Sometimes mild breathing problems are from a stuffy nose or hard ... conditions such as asthma, emphysema or pneumonia cause breathing difficulties. So can problems with your trachea or ...

323

Walking Problems  

MedlinePLUS

... daily activities, get around, and exercise. Having a problem with walking can make daily life more difficult. ... walk is called your gait. A variety of problems can cause an abnormal gait and lead to ...

324

Joint Problems  

MedlinePLUS

... ankles and toes. Other types of arthritis include gout or pseudogout. Sometimes, there is a mechanical problem ... for more information on osteoarthritis, rheumatoid arthritis and gout. How Common are Joint Problems? Osteoarthritis, which affects ...

325

Sampling Distribution of Sample Means  

NSDL National Science Digital Library

This applet generates a graph of the sampling distribution of sample means and displays the probabilities associated with that distribution. Users enter the mean and standard deviation of the source population and the size of the samples. The applet also calculates the standard error of the sample means.

Lowry, Richard

2009-01-08

326

Sampling diffusive transition paths.  

PubMed

The authors address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with the sampling of infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with the sampling of the coarse features of long paths. The fine-feature sampling stiffness is eliminated with the use of the fast sampling algorithm, and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. The authors use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature. PMID:17444696

Miller, Thomas F; Predescu, Cristian

2007-04-14

327

Sampling Distributions  

NSDL National Science Digital Library

This applet simulates and plots the sampling distribution of various statistics (i.e. mean, standard deviation, variance). The applet allows the user to specify the population distribution, sample size, and statistic. An animated sample from the population is shown and the statistic is plotted. This can be repeated to produce the sampling distribution of the statistic. After the sampling distribution is plotted it can be compared to a normal distribution by overlaying a normal curve. These features make it useful for introducing students in a first course to the idea of a sampling distribution. The site also includes instructions and exercises.

Lane, David M.

2009-11-26

328

Order statistics based sampling design for reliability sampling  

Microsoft Academic Search

We consider the problem of designing variables-sampling plans for life testing. Leiberman and Resnikoff, Schneider and many others have considered this problem for location-scale type lifetime distributions. However, in practice, the actual lifetime distribution is often unknown. In this article, we propose a procedure based on order statistics for designing a reliability sampling plan which is applicable to any lifetime

C. K. Low; U. Balasooriya

2007-01-01

329

Pragmatic soil survey design using flexible Latin hypercube sampling  

NASA Astrophysics Data System (ADS)

We review and give a practical example of Latin hypercube sampling in soil science using an approach we call flexible Latin hypercube sampling. Recent studies of soil properties in large and remote regions have highlighted problems with the conventional Latin hypercube sampling approach. It is often impractical to travel far from tracks and roads to collect samples, and survey planning should recognise this fact. Another problem is how to handle target sites that, for whatever reason, are impractical to sample - should one just move on to the next target or choose something in the locality that is accessible? Working within a Latin hypercube that spans the covariate space, selecting an alternative site is hard to do optimally. We propose flexible Latin hypercube sampling as a means of avoiding these problems. Flexible Latin hypercube sampling involves simulated annealing for optimally selecting accessible sites from a region. The sampling protocol also produces an ordered list of alternative sites close to the primary target site, should the primary target site prove inaccessible. We highlight the use of this design through a broad-scale sampling exercise in the Burdekin catchment of north Queensland, Australia. We highlight the robustness of our design through a simulation study where up to 50% of target sites may be inaccessible.

Clifford, David; Payne, James E.; Pringle, M. J.; Searle, Ross; Butler, Nathan

2014-06-01

330

Probability Sampling  

NSDL National Science Digital Library

This site, created by author William M.K. Trochim, describes in detail five different types of random sampling. Some of these types include: simple random, stratified random, systematic random, cluster random, multi-stage sampling. The author provides examples, definitions, and the procedures behind the methods. Overall, this site provides a nice overview of probability sampling.

Trochim, William M.

2008-12-30

331

Astronauts' menu problem.  

NASA Technical Reports Server (NTRS)

Consideration of the problems involved in choosing appropriate menus for astronauts carrying out SKYLAB missions lasting up to eight weeks. The problem of planning balanced menus on the basis of prepackaged food items within limitations on the intake of calories, protein, and certain elements is noted, as well as a number of other restrictions of both physical and arbitrary nature. The tailoring of a set of menus for each astronaut on the basis of subjective rankings of each food by the astronaut in terms of a 'measure of pleasure' is described, and a computer solution to this problem by means of a mixed integer programming code is presented.

Lesso, W. G.; Kenyon, E.

1972-01-01

332

PARENTAL INVOLVEMENT AND ITS RELATIONSHIP TO ORAL ENGLISH FLUENCY AMONG TWO-PARENT MEXICAN AMERICANS WITH CHILDREN ENROLLED IN SELECTED BILINGUAL PROGRAMS  

Microsoft Academic Search

The problem under investigation in this study was to determine whether there was a relationship between parental involvement and oral English fluency of two-parent Mexican Americans whose children were enrolled in selected bilingual education programs. This research was needed in order to identify the reasons or underlying causes for the lack of Mexican American parental involvement.^ The sample for this

JOSE LUIS VALDERAS

1985-01-01

333

Random Samples  

NSDL National Science Digital Library

Created by Kyle Siegrist of the University of Alabama-Huntsville, this is an online, interactive lesson on random samples. The author provides examples, exercises, and applets concerning many different topics. Some of these include: sample mean, law of large numbers, sample variance, partial sums, central limit theorem, special properties of normal samples, order statistics, and sample covariance and correlation. Additionally, the author provides links to external resources for students wanting to engage further with the topic. This is simply one of seventeen lessons. They are all easily accessible as the author has formatted his site much like an online textbook.

Siegrist, Kyle

2009-02-18

334

Weekly Problems  

NSDL National Science Digital Library

This is an archive of previous problems from "Math by the Month", a regular department of Teaching Children Mathematics Journal from NCTM for K-5 teachers that features activities organized by grades K-2 and grades 3-5 and usually based on a theme associated with the particular month. Activities and problems posed are classroom-tested with an inquiry or problem-solving orientation.

2011-01-01

335

Sampling and examination methods used for TMI-2 samples  

SciTech Connect

The purpose of this paper is to summarize the sampling and examination techniques that were used in the collection and analysis of TMI-2 samples. Samples ranging from auxiliary building air to core debris were collected and analyzed. Handling of the larger samples and many of the smaller samples had to be done remotely and many standard laboratory analytical techniques were modified to accommodate the extremely high radiation fields associated with these samples. The TMI-2 samples presented unique problems with sampling and the laboratory analysis of prior molten fuel debris. 14 refs., 8 figs.

Marley, A.W.; Akers, D.W.; McIsaac, C.V.

1988-01-01

336

Lunar Sample Quarantine & Sample Curation  

NASA Technical Reports Server (NTRS)

The main goal of this presentation is to discuss some of the responsibility of the lunar sample quarantine project. The responsibilities are: flying the mission safely, and on schedule, protect the Earth from biohazard, and preserve scientific integrity of samples.

Allton, Judith H.

2000-01-01

337

Lunar Sample Quarantine & Sample Curation  

NASA Astrophysics Data System (ADS)

The main goal of this presentation is to discuss some of the responsibility of the lunar sample quarantine project. The responsibilities are: flying the mission safely, and on schedule, protect the Earth from biohazard, and preserve scientific integrity of samples.

Allton, Judith H.

2000-10-01

338

Pathways of Youth Gambling Problem Severity  

Microsoft Academic Search

Prospective studies are needed to advance knowledge of the developmental features of gambling involvement and associated problems. Developmental pathways of youth gambling problem severity (no problem gambling, at-risk gambling, and problem gambling) are described on the basis of a 3-wave data set that spans midadolescence to young adulthood (N = 305). The most prevalent group was the resistors (no problem

Ken C. Winters; Randy D. Stinchfield; Andria Botzet; Wendy S. Slutske

2005-01-01

339

Teaching Problem Solving to College Students  

ERIC Educational Resources Information Center

This article describes steps of teaching problem solving to college students and provides examples in the context of a university course. The steps involve (1) identifying the types of problems and types of problem solving methods to be covered, (2) instructing the students in problem-recognition and problem solving methods, along with ways of…

Malouff, John M.

2011-01-01

340

Problem Patron Manual.  

ERIC Educational Resources Information Center

This document presents guidelines for handling disruptive behavior in the Schenectady County Public Library (New York). Specific responses are listed for dealing with questions about library selection policy and sudden patron illness or injury. Also listed are responses to problem situations involving angry or irate patrons, assault or physically…

Brown, Marion, Comp.; And Others

341

Children Solve Problems.  

ERIC Educational Resources Information Center

A group of children were presented with several tasks, including the invention of a sleep machine and a machine to weigh elephants. The tasks were chosen to involve the children in coping with problems of a distinct character. A study of the children's drawings and interpretations shows that children's thinking ability is not very different from…

De Bono, Edward

342

Problem Based Learning Initiative  

NSDL National Science Digital Library

This site, The Problem Based Learning Initiative (PBLI), provides education, consultation and support to teachers and organizations in any discipline, profession, training program or educational level (kindergarten through infinity) either involved in PBL or interested in adopting PBL into their teaching or training programs. The site features links to resources and workshops as well as links to many other PBL sites.

University, Southern I.

343

Parking Problem  

ERIC Educational Resources Information Center

This is the story of a real problem, not a problem that is contrived, or invented for the convenience of the appropriate planning tool. This activity by a group of students, defined simply as "8FN", might be likened to an "end of term concert". If you just happened to be a delegate at the ATM Conference 2003 you might remember the analogy. Social…

Foster, Colin

2012-01-01

344

Prostate Problems  

MedlinePLUS

AgePage National Institute on Aging Prostate Problems Stan just found out that a friend has prostate cancer. A lot of men he knows have some kind of problem with their prostate. He’s worried that this might happen to him. ...

345

Tooth Problems  

MedlinePLUS

MENU Return to Web version Tooth Problems See complete list of charts. A tooth that causes ongoing pain may be a sign of a serious problem. Use ... you have an injury that knocked out a tooth? Yes You have TOOTH LOSS. DENTAL EMERGENCY See ...

346

Word Problems  

ERIC Educational Resources Information Center

This study focused on how to help students translate word problems so that they understand how to solve them, and so they are successful with word problems. I have created three research questions to focus on during this research project. First, how will direct instruction of word meaning help clarify the operation needed, affect the achievement…

Fetrow, Jessica

2009-01-01

347

Sample Size  

NSDL National Science Digital Library

In this interactive, online activity students elect a simple random sample to draw conclusions from data as presented in the Hubble Deep Field-North and Hubble Deep Field-South images. The optimal sample size is determined by exploring sample variability, which is introduced through a min/max plot. The mean and median are added in order to pinpoint the spot where variability settles down and the measures of central tendency approach a constant value. The point where that first occurs is the smallest reasonable sample size. Students may work independently or in small groups to complete each activity. This interactive online activity is apart of the online exploration "Galaxy Hunter." Detailed teacher pages, identified as Teaching Tips on the title pages of the activity, provide science background information, lesson plan ideas, related resources, and alignment with national education standards. Use sample variability to determine optimal sample size.

348

Efficiently Determine the Starting Sample Size for Progressive Sampling  

Microsoft Academic Search

Given a large data set and a classification learning algorithm, Progressive Sampling (PS) uses increasingly larger random samples to learn until model accuracy no longer improves. It is shown that the technique is remarkably efficient compared to using the entire data. However, how to set the starting sample size for PS is still an open problem. We show that an

Baohua Gu; Bing Liu; Feifang Hu; Huan Liu

2001-01-01

349

Jocks, gender, race, and adolescent problem drinking.  

PubMed

Alcohol remains the drug of choice for many adolescents; however, the nature of the relationship between athletic involvement and alcohol misuse remains ambiguous. In this article, we used a longitudinal sample of over 600 Western New York adolescents and their families to explore the gender-specific and race-specific relationships between identification with the "jock" label and adolescent alcohol consumption, specifically problem drinking. Operationalization of problem drinking included frequency measures of heavy drinking, binge drinking, and social problems related to alcohol (e.g., trouble with family, friends, school officials over drinking). Self-identified adolescent "jocks" were more likely to engage in problem drinking than their non-jock counterparts, even after controlling for gender, age, race, socioeconomic status, physical maturity, social maturity, and frequency of athletic activity. Jock identity was strongly associated with higher binge drinking frequency in Black adolescent girls. This study underscores the need to distinguish between objective and subjective meanings of athletic involvement when assessing the relationship between sport and adolescent health-risk behavior. PMID:15237868

Miller, Kathleen E; Hoffman, Joseph H; Barnes, Grace M; Farrell, Michael P; Sabo, Don; Melnick, Merrill J

2003-01-01

350

Telescope loading: A problem reduction approach  

NASA Technical Reports Server (NTRS)

This paper presents a problem reduction approach to telescope loading. To study time-varying celestial behavior, astronomers submit periodic observation campaigns which involve a sequence of observations at a given sampling frequency over months or years. The loader's task is to generate an assignment of observation tasks to each night in the time window such that resource demand does not exceed resource capacity and such that the observations usefully contribute to the campaigns' scientific purposes, in a manner that is fair to all participating astronomers.

Bresina, John L.

1994-01-01

351

Lava Sampling  

USGS Multimedia Gallery

An HVO geologist takes a sample of active lava within a lava tube. The fluid lava sticks to the heavy hammer head at the end of the cable when it is lowered into the swiftly moving lava stream. These samples are analyzed routinely to track changes in lava chemistry. ...

2010-06-18

352

Sampling Development  

ERIC Educational Resources Information Center

Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

Adolph, Karen E.; Robinson, Scott R.

2011-01-01

353

On regulation under sampling  

Microsoft Academic Search

The paper deals with linear and nonlinear regulation under sampling. It is shown that digital solutions exist under assumptions which are closely related to the existence of robust solutions to the continuous problem. Approximated solutions are computed starting from the continuous ones

B. Castillo; S. Di Gennaro; S. Monaco; D. Normand-Cyrot

1997-01-01

354

Phylogenetics problems  

NSDL National Science Digital Library

Students receive information about cladistics and apply this phylogenetic approach to two problems, collecting data, determining whether traits are ancestral or derived, and using this information to select the most parsimonious tree.

Deel, Sarah; Walser-Kuntz, Debby

355

Hearing Problems  

MedlinePLUS

... This flow chart will help direct you if hearing loss is a problem for you or a family ... may damage the inner ear. This kind of hearing loss is called OCCUPATIONAL. Prevent occupational hearing loss by ...

356

Elimination Problems  

MedlinePLUS

... information about pain, itching or blood with a bowel movement. SYMPTOMS DIAGNOSIS SELF-CARE Begin Here 1. Is the affected person an infant or child? Yes See Elimination Problems in Infants and Children. No 2. Do ...

357

Problem Periods  

MedlinePLUS

... condition that causes period problems is PCOS, or polycystic ovary syndrome. Read our information on PCOS for teens , and see your doctor if you think you may have PCOS. Major weight loss. Girls who have anorexia will ...

358

Problem Solving  

NSDL National Science Digital Library

Students are introduced to a systematic procedure for solving problems through a demonstration and then the application of the method to an everyday activity. The unit project is introduced to provide relevance to subsequent lessons.

Office Of Educational Partnerships

359

A Parallel Tempering algorithm for probabilistic sampling and multimodal optimization  

NASA Astrophysics Data System (ADS)

Non-linear inverse problems in the geosciences often involve probabilistic sampling of multimodal density functions or global optimization and sometimes both. Efficient algorithmic tools for carrying out sampling or optimization in challenging cases are of major interest. Here results are presented of some numerical experiments with a technique, known as Parallel Tempering, which originated in the field of computational statistics but is finding increasing numbers of applications in fields ranging from Chemical Physics to Astronomy. To date, experience in use of Parallel Tempering within earth sciences problems is very limited. In this paper, we describe Parallel Tempering and compare it to related methods of Simulated Annealing and Simulated Tempering for optimization and sampling, respectively. A key feature of Parallel Tempering is that it satisfies the detailed balance condition required for convergence of Markov chain Monte Carlo (McMC) algorithms while improving the efficiency of probabilistic sampling. Numerical results are presented on use of Parallel Tempering for trans-dimensional inversion of synthetic seismic receiver functions and also the simultaneous fitting of multiple receiver functions using global optimization. These suggest that its use can significantly accelerate sampling algorithms and improve exploration of parameter space in optimization. Parallel Tempering is a meta-algorithm which may be used together with many existing McMC sampling and direct search optimization techniques. It's generality and demonstrated performance suggests that there is significant potential for applications to both sampling and optimization problems in the geosciences.

Sambridge, Malcolm

2014-01-01

360

Conduct Problems, Depressive Symptomatology and Their Co-Occurring Presentation in Childhood as Predictors of Adjustment in Early Adolescence  

Microsoft Academic Search

The present study investigated patterns in the development of conduct problems (CP), depressive symptoms, and their co-occurrence, and relations to adjustment problems, over the transition from late childhood to early adolescence. Rates of depressive symptoms and CP during this developmental period vary by gender; yet, few studies involving non-clinical samples have examined co-occurring problems and adjustment outcomes across boys and

Erin M. Ingoldsby; Gwynne O. Kohl; Robert J. McMahon; Liliana Lengua

2006-01-01

361

Graphical Solutions of Geologic Problems.  

National Technical Information Service (NTIS)

This technical release covers some of the basic techniques in graphical solutions of three dimensional problems involving points, lines and planes. These techniques will give attitude, location, distance, and dimensions in the solution. Techniques for usi...

D. H. Hixon

1969-01-01

362

School Parent Involvement Policy  

ERIC Educational Resources Information Center

This school parent involvement policy is divided into three sections: (1) Development and Adoption of the Parent Involvement Policy; (2) Contents of the Parent Involvement Policy; and (3) Distributing and Revising the School's Parent Involvement Policy. This paper presents the provision of the Section 1118 of Title I of the No Child Left Behind…

Center for Law and Education (NJ3), 2005

2005-01-01

363

Experiment Problems for Electricity and Magnetism.  

ERIC Educational Resources Information Center

Gives several sample experiment problems for electricity and magnetism. To solve an experiment problem, students have to do one or more of the following: clarify a poorly defined problem, divide a problem into parts, access the appropriate concept needed to solve each problem part, decide whether approximations are appropriate, design an…

Van Heuvelen, Alan; Allen, Leith; Mihas, Pavlos

1999-01-01

364

Predicting early adolescent gang involvement from middle school adaptation.  

PubMed

This study examined the role of adaptation in the first year of middle school (Grade 6, age 11) to affiliation with gangs by the last year of middle school (Grade 8, age 13). The sample consisted of 714 European American (EA) and African American (AA) boys and girls. Specifically, academic grades, reports of antisocial behavior, and peer relations in 6th grade were used to predict multiple measures of gang involvement by 8th grade. The multiple measures of gang involvement included self-, peer, teacher, and counselor reports. Unexpectedly, self-report measures of gang involvement did not correlate highly with peer and school staff reports. The results, however, were similar for other and self-report measures of gang involvement. Mean level analyses revealed statistically reliable differences in 8th-grade gang involvement as a function of the youth gender and ethnicity. Structural equation prediction models revealed that peer nominations of rejection, acceptance, academic failure, and antisocial behavior were predictive of gang involvement for most youth. These findings suggest that the youth level of problem behavior and the school ecology (e.g., peer rejection, school failure) require attention in the design of interventions to prevent the formation of gangs among high-risk young adolescents. PMID:15677281

Dishion, Thomas J; Nelson, Sarah E; Yasui, Miwa

2005-03-01

365

Orbit/deorbit analysis for the Mars rover sample return mission  

NASA Technical Reports Server (NTRS)

Four astrodynamic problems involved in a combined Mars rover and surface sample return mission projected for the early 1990s are explored. Two of the problems are associated with the satisfaction of the specific mission requirements at Mars, calling for the initial orbit entered into at Mars to be highly eccentric and to have a very low periapsis altitude (about 250 km). The problem of placing an areosynchronous communications satellite in orbit around Mars is then discussed. Finally, the problem of deorbiting to a specified landing site from a highly eccentric orbit is considered.

Penzo, Paul A.

1988-01-01

366

Involving Health Care Workers in Screening for Alcohol Problems  

Microsoft Academic Search

Objectives: (1) Examine physician and nursing staff compliance with conducting an alcohol screening interview; (2) Compare compliance with the interview with usual physician and nurse assessment of drinking; (3) Examine reasons why drinking information might not be collected. Design: Residents and nurses were taught how to use an alcohol screening interview and were told by the director of residency training

Barbara S McCrady; Stephanie S. Richter; Thomas J. Morgan; John Slade; Carl Pfeifer

1996-01-01

367

Analytical Solution to Diffraction Problems Involving Periodically Structured Objects.  

National Technical Information Service (NTIS)

A rigorous analysis of diffraction by rectangularly profiled, dielectric gratings is presented. An analytical solution is obtained for the total electromagnetic field. The approach presented can readily be extended to computations for metallic gratings an...

M. Akbari T. Magath

2000-01-01

368

DOPING IN SPORT: PROBLEMS OF INVOLVEMENT AND DETACHMENT  

Microsoft Academic Search

In some respects, public attitudes towards drug use appear curiously ambivalent for, though most people would strongly deprecate both the use of performance-enhancing drugs in sport and'drug abuse'within the wider society, it is almost certainly the case that, in modern western societies, we have come to be more dependent on the use of prescribed drugs than at any previous time

Ivan Waddington

2000-01-01

369

Manual of Analytical Quality Control for Pesticides and Related Compounds in Human and Environmental Samples. A Compendium of Systematic Procedures Designed to Assist in the Prevention and Control of Analytical Problems.  

National Technical Information Service (NTIS)

This manual provides the pesticide chemist with a systematic protocol for the quality control of analytical procedures and the problems that arise in the analysis of human or environmental media. It also serves as a guide to the latest and most reliable m...

J. Sherma M. Beroza

1979-01-01

370

MANUAL OF ANALYTICAL QUALITY CONTROL FOR PESTICIDES AND RELATED COMPOUNDS IN HUMAN AND ENVIRONMENTAL SAMPLES. A COMPENDIUM OF SYSTEMATIC PROCEDURES DESIGNED TO ASSIST IN THE PREVENTION AND CONTROL OF ANALYTICAL PROBLEMS  

EPA Science Inventory

This manual provides the pesticide chemist with a systematic protocol for the quality control of analytical procedures and the problems that arise in the analysis of human or environmental media. It also serves as a guide to the latest and most reliable methodology available for ...

371

Contextual Problem Solving Model Origination  

ERIC Educational Resources Information Center

Problem solving has become a central focus of instructional activity in technology education classrooms at all levels (Boser, 1993). Impact assessment considerations incorporating society, culture, and economics are factors that require high-level deliberation involving critical thinking and the implementation of problem solving strategy. The…

Ernst, Jeremy V.

2009-01-01

372

Broadcast Search in Problem Solving: Attracting Solutions From the Periphery  

Microsoft Academic Search

The purpose of this study is to explore an alternative mechanism of problem solving that focuses on broadcasting problems to diverse and peripheral problem solvers, what I call broadcast search. Broadcasting problems is a radical departure from traditional problem solving as it involves problem holders engaging in as little problem-solving as possible - instead they attempt to interest a heterogeneous

Karim R. Lakhani

2006-01-01

373

Sampling apparatus  

DOEpatents

A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

Gordon, N.R.; King, L.L.; Jackson, P.O.; Zulich, A.W.

1989-07-18

374

Enhanced conformational sampling using enveloping distribution sampling.  

PubMed

To lessen the problem of insufficient conformational sampling in biomolecular simulations is still a major challenge in computational biochemistry. In this article, an application of the method of enveloping distribution sampling (EDS) is proposed that addresses this challenge and its sampling efficiency is demonstrated in simulations of a hexa-?-peptide whose conformational equilibrium encompasses two different helical folds, i.e., a right-handed 2.7(10?12)-helix and a left-handed 3(14)-helix, separated by a high energy barrier. Standard MD simulations of this peptide using the GROMOS 53A6 force field did not reach convergence of the free enthalpy difference between the two helices even after 500 ns of simulation time. The use of soft-core non-bonded interactions in the centre of the peptide did enhance the number of transitions between the helices, but at the same time led to neglect of relevant helical configurations. In the simulations of a two-state EDS reference Hamiltonian that envelops both the physical peptide and the soft-core peptide, sampling of the conformational space of the physical peptide ensures that physically relevant conformations can be visited, and sampling of the conformational space of the soft-core peptide helps to enhance the transitions between the two helices. The EDS simulations sampled many more transitions between the two helices and showed much faster convergence of the relative free enthalpy of the two helices compared with the standard MD simulations with only a slightly larger computational effort to determine optimized EDS parameters. Combined with various methods to smoothen the potential energy surface, the proposed EDS application will be a powerful technique to enhance the sampling efficiency in biomolecular simulations. PMID:24116601

Lin, Zhixiong; van Gunsteren, Wilfred F

2013-10-14

375

Instructional Effects on Performance in a Matching-to-Sample Study  

ERIC Educational Resources Information Center

Conducting studies using an undergraduate participant pool is fraught with difficulties. Among them are problems with adequately motivating subjects both to come to the study, and once there, to actively engage the experimental task. Thirty-one college students participated in a matching-to-sample (MTS) study involving substantial training,…

Drake, Chad E.; Wilson, Kelly G.

2008-01-01

376

Multiple Matrix Sampling Applied to Needs Analysis: An Introduction and Assessment of Efficacy.  

ERIC Educational Resources Information Center

A common approach to needs analysis involves the development of a self-report questionnaire administered to members of the intended audience. Such an approach poses a problem however: Concern for data reliability demands polling as many respondents as possible, while concern for cost-effectiveness dictates minimizing the size of the sample. The…

Misanchuk, Earl R.

377

Digital Computer Solution of Magnetic Field Problems.  

National Technical Information Service (NTIS)

A computer program for the analysis of magnetic field problems involving ferromagnetic materials is described. A discussion of the equations describing such problems, the boundary conditions employed, and the method of modeling on a digital computer is pr...

C. M. DeSantis

1970-01-01

378

Training Metacognitive Skills for Problem Solving.  

National Technical Information Service (NTIS)

Metacognitive skills that involve monitoring and control of cognitive skills like problem solving develop in expert executives and lead to great improvement in the problem-solving process. In this report, we review theory and research on metacognition to ...

J. Geiwitz

1994-01-01

379

Word Problems: A "Meme" for Our Times.  

ERIC Educational Resources Information Center

Discusses a novel approach to word problems that involves linear relationships between variables. Argues that working stepwise through intermediates is the way our minds actually work and therefore this should be used in solving word problems. (JRH)

Leamnson, Robert N.

1996-01-01

380

The Problem of Managing a Strategic Reserve.  

ERIC Educational Resources Information Center

The problem of managing the reserve of cobalt is presented, followed by a method for bringing the stockpiled amount from any level to a desired goal. Solving a stochastic programming problem is involved. The procedure is discussed in detail. (MNS)

Cole, David; And Others

1986-01-01

381

Measurement Problems.  

ERIC Educational Resources Information Center

Focusing on educational measurement that suggests an action and has an outcome, 16 problem areas are defined and grouped into the following classes: (1) validity; (2) issues of statistical adjustment; (3) data insufficiencies; (4) other issues related to standardized testing and constructed responses; and (5) technical issues of psychometrics.…

Wainer, Howard

1993-01-01

382

Heat Problems.  

ERIC Educational Resources Information Center

Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

Connors, G. Patrick

383

[Shiftwork problems].  

PubMed

This paper discusses the negative effects of shiftwork which are classified into four categories: biological functions, efficiency, social/family domains and health. It presents systematic review of previous studies which indicated at health problems in shiftworkers which can, at least in part, be attributed to disturbation of circadian rhythms imposed by shift/night work. Health problems which are connected with shiftwork are: sleeping problems, gastrointestinal and cardiovascular diseases, carcinoma, problems with reproductive health in women and lower levels of psychological health.The paper also discusses about shiftwork tolerance. The process model of shiftwork and health, made by Smith and his coworkers in 1999, is used as theoretical framework. An accent is put on individual and organisational factors which are important for shiftwork adaptation and tolerance. Significant predictors of shiftwork tolerance are: age, gender, morningness-eveningness, rigidity-flexibility of sleeping habits, family situation, sleep hygiene and food intake. Regarding studies which indicated important aspects of shiftwork organization, such as: number of working shifts and working hours, regularity of shifts, pace and direction of shifts' rotation, recommendations for shiftwork management are given. PMID:21183438

2010-12-01

384

Puzzles & Problems.  

ERIC Educational Resources Information Center

"Exploring" is a magazine of science, art, and human perception, produced by Exploratorium in collaboration with other participating museums. This issue focuses on puzzles and problem solving. Brain teasers, puzzles, and the strategies for solving them are included. Features include: (1) "Homework Assignment #3" (Paul Doherty); (2) "The Case of…

Murphy, Pat, Ed.

1993-01-01

385

Research on Computers and Problem Solving.  

ERIC Educational Resources Information Center

Eight articles review and report on research involving computers and problem solving skills. Topics discussed include research design; problem solving skills and programing languages, including BASIC and LOGO; computer anxiety; diagnostic programs for arithmetic problems; and relationships between ability and problem solving scores and between…

Burton, John K.; And Others

1988-01-01

386

"Seed Problems" in the Teaching of Mathematics.  

ERIC Educational Resources Information Center

The technique of using "seed problems" involves starting with a simple problem and seeing how far it leads. It may inspire different, related problems, or it may be approached with varied tools. Problems related to points and lines, pyramids, Pythagorean quadruples, and regular pentagons are discussed. (MNS)

McLoughlin, Patrick

1987-01-01

387

Water Sampling  

USGS Multimedia Gallery

On April 20, 2010, the Deepwater Horizon Drilling Platform exploded and sank, causing an enormous oil spill in the Gulf of Mexico. U.S. Geological Survey field offices responded immediately by organizing teams to take pre-spill sediment and water samples in order to establish a baseline survey. This...

2010-06-04

388

Atmospheric sampling  

NASA Astrophysics Data System (ADS)

Four important sampling techniques are briefly reviewed: Selective sampling on impregnated filters for measuring acidic gases, the matrix isolation technique for measuring radicals, whole air grabsampling and whole air cryogenic sampling for measuring stable source gases. Vertical profiles of H2, CH4, CO, N2O, CFCl3 and CF2Cl2 resulting from gas chromatographic analysis of whole air samples collected with a cryogenic sampler are presented. Year-to-year variations are observed for H2, CH4 and N2O above 25 km, while CFCl, and CF2Cl2 mixing ratios show a noticeable increase between 1977 and 1979 at almost every height level. The CO2 mixing ratio is not constant with height but rather decreases from 332 ppmV at 10 km to 325 ppmV at 30 km. The vertical distribution of methyl chloride is characterized by a rapid decrease from 600 pptV in the troposphere to less than 10 pptV at 32 km in agreement with model results.

Fabian, P.

389

Sand Sampling  

USGS Multimedia Gallery

On April 20, 2010, the Deepwater Horizon Drilling Platform exploded and sank, causing an enormous oil spill in the Gulf of Mexico. U.S. Geological Survey field offices responded immediately by organizing teams to take pre-spill sediment and water samples in order to establish a baseline survey. This...

2010-06-04

390

Feeding problems in cystinosis  

Microsoft Academic Search

.   Nephropathic cystinosis, a rare autosomal recessive storage disease characterized by intracellular storage of free cystine\\u000a due to a defect in lysosomal cystine transport, is the most common cause of Fanconi syndrome in childhood. Although manifestations\\u000a of extrarenal organ involvement during the course of the disease are diverse, the spectrum of gastrointestinal (GI) problems\\u000a has not yet been examined. In

Ewa Elenberg; Laura L. Norling; Ronald E. Kleinman; Julie R. Ingelfinger

1998-01-01

391

SOIL AND SEDIMENT SAMPLING METHODS  

EPA Science Inventory

The EPA Office of Solid Waste and Emergency Response's (OSWER) Office of Superfund Remediation and Technology Innovation (OSRTI) needs innovative methods and techniques to solve new and difficult sampling and analytical problems found at the numerous Superfund sites throughout th...

392

Organic contamination problems in the Viking molecular analysis experiment  

NASA Technical Reports Server (NTRS)

A principal problem in interpreting the results of an organic analysis of an extraterrestrial sample is that of distinguishing contaminating material from indigenous material when unknown types and amounts of contaminants make their way into the sample being analyzed. An approach to control of sample integrity in the Viking molecular analysis experiment has been devised which it is believed, will eliminate such problems. Basically this involves (1) placing an upper limit on the amount of terrestrial contamination that can be tolerated and still allow scientifically meaningful analysis, (2) identifying the potential sources of contamination and analyzing their relative significance, (3) establishing methods to control these sources, and (4) obtaining complete information on the chemical composition of potential contaminants. Previous experience in the Apollo mission has been of great value in developing the Viking program, perhaps the most important carryover being the recognition of the importance of establishing a comprehensive contamination control program in the early stages of mission planning and hardware design.

Flory, D. A.; Oro, J.; Fennessey, P. V.

1974-01-01

393

Gene-by-Preschool Interaction on the Development of Early Externalizing Problems  

ERIC Educational Resources Information Center

Background: Preschool involves an array of new social experiences that may impact the development of early externalizing behavior problems over the transition to grade school. Methods: Using longitudinal data from a nationally representative sample of over 600 pairs of US twins, we tested whether the genetic and environmental influences on…

Tucker-Drob, Elliot M.; Harden, K. Paige

2013-01-01

394

Dimensions of Early Childhood Behavior Problems: Stability and Predictors of Change from 18 to 30 Months  

Microsoft Academic Search

The prevalence, structure, stability, and predictors of change in early behavior problems were examined in a population-based sample of Norwegian children at 18 and 30 months of age (N = 750). A clear factor structure involving four dimensions emerged at both assessment times: Two factors were characterized by externalizing behaviors and were labeled Social Adjustment and Overactive-Inattentive; one factor tapped

Kristin S. Mathiesen; Ann Sanson

2000-01-01

395

The Association between Parental Personality Patterns and Internalising and Externalising Behaviour Problems in Children and Adolescents  

ERIC Educational Resources Information Center

Background: This study investigated the relationship between parental personality patterns and internalising and externalising behaviour problems in a clinically referred sample of children (aged 4-8) and adolescents (aged 12-18). Methods: Data from families involved in two clinical trials in Victoria, Australia were analysed (n = 59). Families…

Bertino, Melanie D.; Connell, Gabrielle; Lewis, Andrew J.

2012-01-01

396

Bidirectional Associations between Temperament and Parenting and the Prediction of Adjustment Problems in Middle Childhood  

ERIC Educational Resources Information Center

This study examined longitudinal associations between child temperament (fearfulness, irritability, positive emotionality, self-regulation) and parenting (acceptance, involvement, inconsistent discipline) in predicting children's internalizing and externalizing problems using a community sample (N = 92) of children (ages 8-11) and their mothers.…

Lengua, L.J.; Kovacs, E.A.

2005-01-01

397

Involving Latino Parents.  

ERIC Educational Resources Information Center

Describes barriers to Latino parent involvement in educational activities, factors to consider when involving Latino parents, and two examples of Latino involvement programs in California: Family Literacy Workshop at James Monroe Elementary School, Madera Unified School District, and Parents Take P.A.R.T. (Parent Assisted Reading Training) at…

Quezada, Reyes L.; Diaz, Delia M.; Sanchez, Maria

2003-01-01

398

SAMPLES Program  

NSDL National Science Digital Library

The objective of the SAMPLES (Sandia Agile MEMS Prototyping, Layout Tools, Education and Services) Program is to enable customers to develop their own innovative products by leveraging advanced design, fabrication, and characterization technologies originally developed for National Laboratory applications. Participants can attend short courses, design new devices, and have those designs fabricated in our state-of-the-art fabrication facility. Additional cost-effective services are also available.

Hanselmann, Kathryn

2009-07-21

399

Bias Sampling  

NSDL National Science Digital Library

In this statistics lesson on bias sampling students conduct a poll of specific populations within their school to determine recommendations for homework policies. Each of three groups is assigned a population to survey and then reports their conclusions to the class. Students will then determine how to improve their survey in order to get unbiased results. A student worksheet for questions and a student template for a letter to the principal are included.

2012-01-01

400

Annealed Importance Sampling Reversible Jump MCMC algorithms  

SciTech Connect

It will soon be 20 years since reversible jump Markov chain Monte Carlo (RJ-MCMC) algorithms have been proposed. They have significantly extended the scope of Markov chain Monte Carlo simulation methods, offering the promise to be able to routinely tackle transdimensional sampling problems, as encountered in Bayesian model selection problems for example, in a principled and flexible fashion. Their practical efficient implementation, however, still remains a challenge. A particular difficulty encountered in practice is in the choice of the dimension matching variables (both their nature and their distribution) and the reversible transformations which allow one to define the one-to-one mappings underpinning the design of these algorithms. Indeed, even seemingly sensible choices can lead to algorithms with very poor performance. The focus of this paper is the development and performance evaluation of a method, annealed importance sampling RJ-MCMC (aisRJ), which addresses this problem by mitigating the sensitivity of RJ-MCMC algorithms to the aforementioned poor design. As we shall see the algorithm can be understood as being an “exact approximation” of an idealized MCMC algorithm that would sample from the model probabilities directly in a model selection set-up. Such an idealized algorithm may have good theoretical convergence properties, but typically cannot be implemented, and our algorithms can approximate the performance of such idealized algorithms to an arbitrary degree while not introducing any bias for any degree of approximation. Our approach combines the dimension matching ideas of RJ-MCMC with annealed importance sampling and its Markov chain Monte Carlo implementation. We illustrate the performance of the algorithm with numerical simulations which indicate that, although the approach may at first appear computationally involved, it is in fact competitive.

Karagiannis, Georgios; Andrieu, Christophe

2013-03-20

401

Natural History of Alcohol Dependence and Remission Events for a Native American Sample*  

PubMed Central

Objective Examining the progression of a disorder cross-culturally may help distinguish elements common to addictions from those that are differentially shaped by culture. This study sought to construct a combined sequence of both problem emergence and recovery efforts with Native Americans. Method In a cross-sectional sample, 44 adult Native Americans (61% men) who had resolved alcohol dependence completed face-to-face interviews at a research center. The Alcohol Related Behaviors Survey and the Change Effort Card-sorts along with measures of alcohol involvement and current quality of life were administered. Results This sample’s sequence of alcohol-related events was compared to that reported for Jellinek’s historical while male sample (rs = .46, p = .001), a recent Navajo sample (rs = .33, p = .024), and a recent Mission Indian sample (rs = .28, p = 24). This sample’s sequence of change efforts was compared to that in the Navajo sample (rs = .33, p = .182). Conclusions Despite the small sample size precluding generalizability, there was greater concordance between this intertribal sample and Jellinek’s while male sample than between this sample and a Mission Indian sample, indicating both cross-cultural and intracultural variation. In addition, change efforts begin during the development of alcohol problems rather than waiting until the person “hits bottom,” as suggested by previous research. Integrating the pathology of substance-use disorders with the process of resolving those disorders extends our understanding of the course of alcohol dependence.

Venner, Kamilla L.; Feldstein, Sarah W.

2010-01-01

402

Alcohol Use, Alcohol Problems, and Depressive Symptomatology Among Newly Married Couples  

PubMed Central

Background: Individuals married to heavy drinking spouses often have poorer health compared to those whose spouses are not heavy drinkers. This work examined how one spouse’s alcohol involvement and alcohol-related problems affect his/her spouse’s depressive symptomatology over time. Methods: Couples (N = 634) were assessed for past year alcohol involvement and alcohol-related problems (marital and non-marital) and depressive symptomatology when they applied for a marriage license. They were reassessed at their first and second anniversaries. Multilevel models were used to analyze the association between one spouse’s alcohol involvement and alcohol problems and his/her partner’s depressive symptomatology over time. Results: Both husbands’ and wives’ marital alcohol problems were associated with wives’ depressive symptoms. Neither spouses’ alcohol consumption was associated with wives’ depressive symptoms. Husbands’ marriage-related alcohol problems and frequency of heavy drinking were related to husbands’ depressive symptoms; however, wives’ alcohol problems and alcohol use were unrelated to husbands’ depression. Conclusions: In a community sample of married couples, we found that husbands’ and wives’ marital alcohol problems affect wives’ depressive symptoms, but only husbands’ marital alcohol problems affect husbands’ depressive symptoms. Future work should consider other subgroups of alcohol-related problems in one spouse and their relation to depression in his/her partner.

Homish, Gregory G.; Leonard, Kenneth E.; Kearns-Bodkin, Jill N.

2006-01-01

403

Macrodystrophia lipomatosa of foot involving great toe.  

PubMed

Macrodystrophia lipomatosa is a rare form of congenital disorder in which there is localized gigantism characterized by progressive overgrowth of all mesenchymal elements with a disproportionate increase in the fibroadipose tissues. The adipose tissue infiltration involves subcutaneous tissue, periosteum, nerves and bone marrow. Most of the cases reported have hand or foot involvement. Patient seeks medical help for improving cosmesis or to get the size of the involved part reduced in order to reduce mechanical problems. We report a case of macrodystrophia lipomatosa involving medial side of foot with significant enlargement of great toe causing concern for cosmesis and inconvenience due to mechanical problems. The X-rays showed increased soft tissue with more of adipose tissue and increased size of involved digits with widening of ends. Since the patient's mother did not want any surgical intervention he was educated about foot care and proper footwear design was suggested. PMID:24703060

Gaur, A K; Mhambre, A S; Popalwar, H; Sharma, R

2014-06-01

404

Transitions Into and Out of Intercollegiate Athletic Involvement and Risky Drinking  

PubMed Central

Objective: Cross-sectional data show that college athletes consume more alcohol and experience more general alcohol-related problems than those not participating in athletics. To our knowledge, the current study is the first to use a longitudinal design to examine the extent to which the course of drinking and alcohol-related problems relates to involvement in intercollegiate athletics, including transitioning into and out of athletic involvement. Method: Participants were drawn from a sample of 3,720 college students from the Intensive Multivariate Prospective Alcohol College-Transitions Study who completed a survey every semester through their fourth year. Four groups were created based on athletic involvement status at baseline (freshman year) and follow-up (senior year): nonathlete, nonathlete (no reported athletic involvement at either time point), nonathlete, athlete (nonathlete at freshman year, athlete at senior year), athlete, nonathlete (athlete at freshman year, nonathlete at senior year), and athlete, athlete (athlete at freshman year, athlete at senior year). Results: A series of repeated measures analyses were then conducted to test for developmental differences among the athlete groups involving alcohol consumption and alcohol-related problems. Although findings differed as a function of alcohol outcome and comparison among various groups with differing athletic involvement, the general pattern of results showed that individuals who were more athletically involved demonstrated sharper increases in problem drinking (i.e., heavy drinking, frequency of intoxication, alcohol-related problems) during the college years. Conclusions: These findings highlight the apparent risk associated with participation in intercollegiate athletics on college drinking.

Cadigan, Jennifer M.; Littlefield, Andrew K.; Martens, Matthew P.; Sher, Kenneth J.

2013-01-01

405

Biomolecular modeling: Goals, problems, perspectives.  

PubMed

Computation based on molecular models is playing an increasingly important role in biology, biological chemistry, and biophysics. Since only a very limited number of properties of biomolecular systems is actually accessible to measurement by experimental means, computer simulation can complement experiment by providing not only averages, but also distributions and time series of any definable quantity, for example, conformational distributions or interactions between parts of systems. Present day biomolecular modeling is limited in its application by four main problems: 1) the force-field problem, 2) the search (sampling) problem, 3) the ensemble (sampling) problem, and 4) the experimental problem. These four problems are discussed and illustrated by practical examples. Perspectives are also outlined for pushing forward the limitations of biomolecular modeling. PMID:16761306

van Gunsteren, Wilfred F; Bakowies, Dirk; Baron, Riccardo; Chandrasekhar, Indira; Christen, Markus; Daura, Xavier; Gee, Peter; Geerke, Daan P; Glättli, Alice; Hünenberger, Philippe H; Kastenholz, Mika A; Oostenbrink, Chris; Schenk, Merijn; Trzesniak, Daniel; van der Vegt, Nico F A; Yu, Haibo B

2006-06-19

406

Anatomy of the Selection Problem  

Microsoft Academic Search

This article considers anew the problem of estimating a regression E(y|x) when realizations of (y, x) are sampled randomly but y is observed selectively. The central issue is the failure of the sampling process to identify E(y|x). The problem faced by the researcher is to find correct prior restrictions which, when combined with the data, identify the regression. Two kinds

Charles F. Manski

1989-01-01

407

A qualitative study of migraine involving patient researchers  

PubMed Central

Background Migraine is poorly managed in primary care despite a high level of morbidity. The majority of sufferers use non-prescription medications and are reluctant to seek help but the reasons for this are not understood. Aim The aim of this study was to develop a research partnership between migraine sufferers and healthcare professionals to synthesise tacit and explicit knowledge in the area. Building upon this partnership, a further aim was to explore what it is to suffer with migraine from patients' perspectives in order to inform health service delivery. Design Qualitative interview study involving healthcare professionals and patient researchers. Setting A purposeful sample of eight migraine sufferers who had attended a local intermediate care headache clinic. Method A consensual qualitative approach. Results Migraine had a high and unrecognised impact on quality of life. ‘Handling the beast’ was a central metaphor that resonated with the experience of all sufferers who sought to control their problem in different ways. Three major themes were identified: making sense of their problem; actively doing something about it either through self-help or professional advice; being resigned to it. Conclusion Despite a significant impact on the quality of life of migraine sufferers and their families, their needs remain largely unmet. Useful insights can be obtained when patients and professionals work together in true partnership but the time and effort involved should not be underestimated. Further research is needed to identify why there are major deficiencies in delivering care in this common problem.

Belam, Judith; Harris, Gill; Kernick, David; Kline, Frances; Lindley, Krissy; McWatt, Jayne; Mitchell, Annie; Reinhold, Debbie

2005-01-01

408

Displacement and Suicide Risk for Juvenile Justice-Involved Youth with Mental Health Issues  

Microsoft Academic Search

This article examined the relationship between suicide behaviors and displacement, as defined by out-of-home placement, in a sample of juvenile-justice-involved youth with mental health issues. Participants included boys and girls between the ages of 10 and 18 who were enrolled in a juvenile justice diversion program for children with mental or behavioral health problems. Data collected included youth-reported suicide and

Jeff M. Kretschmar; Daniel J. Flannery

2011-01-01

409

Efficiently Determining the Starting Sample Size for Progressive Sampling  

Microsoft Academic Search

Given a large data set and a classification learning algorithm, Progressive Sampling (PS) uses increasingly larger random\\u000a samples to learn until model accuracy no longer improves. It is shown that the technique is remarkably efficient compared\\u000a to using the entire data. However, how to set the starting sample size for PS is still an open problem. We show that an

Baohua Gu; Bing Liu; Feifang Hu; Huan Liu

410

The Birthday Problem  

NSDL National Science Digital Library

This lesson, created by faculty members at the University of Virginia, is based on Lawrence Lesser's article that describes the set-up of the spreadsheet simulation and Cindia Stewart's lesson that seeks to answer the Birthday Problem using three different methods. Probability topics include: sample size, Law of Large Numbers, complementary probabilities, and independence of events. The authors include external reference for those looking for more resources on this subject.

2009-03-24

411

Curriculum and Community Involvement  

ERIC Educational Resources Information Center

Historically, the consolidation of school districts has brought with it many promises and perils. In this paper, the author links curriculum and community involvement within the consolidation context.

Feldmann, Doug

2006-01-01

412

Problems without Numbers--At First  

ERIC Educational Resources Information Center

Three sample physics problems are presented in this article. The solutions to the three problems addresses a major student difficulty in problem solving--knowing where to begin. The first suggested step is to begin by stating what is asked for. Step 2 is identifying the fundamental physics that underlies the problem situation. Step 3 is isolating…

Hewitt, Paul G.

2006-01-01

413

Determination of gold and the platinum group elements in geological samples by ICP-MS after nickel sulphide fire assay: difficulties encountered with different types of geological samples.  

PubMed

Problems involved in the determination of Au and the platinum group elements by the nickel sulphide fire assay (NiS-FA) procedure for black shale samples, samples containing magnetite, and samples containing As, Cu, and Fe were studied. The interference of the graphite in black shale samples was eliminated either by roasting the sample prior to fusion or by adding an oxidant to the fusion flux. Addition of a reducing agent to samples, containing the oxygen-rich mineral magnetite, enabled the NiS-FA procedure to be carried out for this sample type. The interference of Cu on Rh in the ICP-MS determination was corrected by establishing a linear correlation between the interference of Cu on (103)Rh and (105)Pd. PMID:18968787

Juvonen, R; Lakomaa, T; Soikkeli, L

2002-09-12

414

The Contribution of Game Genre and other Use Patterns to Problem Video Game Play among Adult Video Gamers.  

PubMed

AIMS: To assess the contribution of patterns of video game play, including game genre, involvement, and time spent gaming, to problem use symptomatology. DESIGN: Nationally representative survey. SETTING: Online. PARTICIPANTS: Large sample (n=3,380) of adult video gamers in the US. MEASUREMENTS: Problem video game play (PVGP) scale, video game genre typology, use patterns (gaming days in the past month and hours on days used), enjoyment, consumer involvement, and background variables. FINDINGS: Study confirms game genre's contribution to problem use as well as demographic variation in play patterns that underlie problem video game play vulnerability. CONCLUSIONS: Identification of a small group of game types positively correlated with problem use suggests new directions for research into the specific design elements and reward mechanics of "addictive" video games. Unique vulnerabilities to problem use among certain groups demonstrate the need for ongoing investigation of health disparities related to contextual dimensions of video game play. PMID:23284310

Elliott, Luther; Ream, Geoffrey; McGinsky, Elizabeth; Dunlap, Eloise

2012-12-01

415

The Contribution of Game Genre and other Use Patterns to Problem Video Game Play among Adult Video Gamers  

PubMed Central

Aims To assess the contribution of patterns of video game play, including game genre, involvement, and time spent gaming, to problem use symptomatology. Design Nationally representative survey. Setting Online. Participants Large sample (n=3,380) of adult video gamers in the US. Measurements Problem video game play (PVGP) scale, video game genre typology, use patterns (gaming days in the past month and hours on days used), enjoyment, consumer involvement, and background variables. Findings Study confirms game genre's contribution to problem use as well as demographic variation in play patterns that underlie problem video game play vulnerability. Conclusions Identification of a small group of game types positively correlated with problem use suggests new directions for research into the specific design elements and reward mechanics of “addictive” video games. Unique vulnerabilities to problem use among certain groups demonstrate the need for ongoing investigation of health disparities related to contextual dimensions of video game play.

Ream, Geoffrey; McGinsky, Elizabeth; Dunlap, Eloise

2012-01-01

416

Analytical Services for Special Measurement Problems.  

National Technical Information Service (NTIS)

Efforts in the area of analytical services to NIOSH for special measurement problems are summarized. Samples were difficult to analyze and outside the scope of typical analytical problems handled by NIOSH laboratories. Twenty-three benzene (71432) soluble...

1975-01-01

417

Image correlation and sampling study  

NASA Technical Reports Server (NTRS)

The development of analytical approaches for solving image correlation and image sampling of multispectral data is discussed. Relevant multispectral image statistics which are applicable to image correlation and sampling are identified. The general image statistics include intensity mean, variance, amplitude histogram, power spectral density function, and autocorrelation function. The translation problem associated with digital image registration and the analytical means for comparing commonly used correlation techniques are considered. General expressions for determining the reconstruction error for specific image sampling strategies are developed.

Popp, D. J.; Mccormack, D. S.; Sedwick, J. L.

1972-01-01

418

Building Parent Involvement  

ERIC Educational Resources Information Center

Discussed is the rationale behind parent involvement in guidance and educational activities, together with specific suggestions for involving parents with other adults (parent advisory committees, informal coffees, Transactional analysis (groups etc.), with children (story hours, trips, demonstrations, counseling booths, testing, interviewing,…

Nelson, Richard C.; Bloom, John W.

1973-01-01

419

Osseous involvement in rhinosporidiosis  

PubMed Central

Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi. It usually affects the mucocutaneous tissue of the nose. Bone involvement is rare. We report a case of Rhinosporidiosis of the nasopharynx which later involved the right little finger where ray amputation was performed.

Kundu, Atin Kumar; Phuljhele, Satyendra; Jain, Mantu; Srivastava, Raman Kumar

2013-01-01

420

Genes Involved in Atherosclerosis  

Microsoft Academic Search

Atherosclerosis is a multifactorial disease that involves several genes and proteins. The purpose of this article is to focus on the arterial wall and to review lipoprotein receptors, growth factors, cytokines, chemokines, matrix metalloproteinases, adhesion molecules, and apoptosis genes and their involvement in atherogenesis.

Johanna Laukkanen; Seppo Ylä-Herttuala

2002-01-01

421

Student Involvement in Health  

ERIC Educational Resources Information Center

As the major consumers of health care at the university level, students should become involved in the entire process of providing such care, including the formulation of programs and procedures, choice of personnel, public relations, and involvement on the national level through the American College Health Association. (MB)

Simches, Sherri A.

1976-01-01

422

Osseous involvement in rhinosporidiosis.  

PubMed

Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi. It usually affects the mucocutaneous tissue of the nose. Bone involvement is rare. We report a case of Rhinosporidiosis of the nasopharynx which later involved the right little finger where ray amputation was performed. PMID:24133316

Kundu, Atin Kumar; Phuljhele, Satyendra; Jain, Mantu; Srivastava, Raman Kumar

2013-09-01

423

Airborne atmospheric sampling system  

NASA Technical Reports Server (NTRS)

The atmospheric sampling system developed for use on board commercial airliners as part of the Global Atmospheric Sampling Program (GASP) is described. The automated air-constituent measuring system is installed in a Boeing 747 airliner below the passenger cabin floor near the nose wheel well. It consists of an air sample flow system, composed of air inlet and pressurization systems, computerized data acquisition and system control units which direct system operation in 15 modes, and commercial instruments significantly modified to measure low levels of atmospheric constituents (ozone, water vapor, nitrogen oxides, carbon monoxide, chlorofluoromethanes, particulates, condensation nuclei, sulfates and nitrates). Flight and meteorological data, including air temperature and altitude, are also recorded. The system is designed for servicing at 14-day intervals, and to require a minimum of aircrew involvement.

Gustafsson, U. R. C.; Perkins, P. J.; Nyland, T. W.; Tiefermann, M. W.; Dudzinski, T. J.

1979-01-01

424

Problem Analysis Using Small Problem Frames  

Microsoft Academic Search

The notion of a problem frame is introduced and explained, and its use in analysing and structuring problems is illustrated. A problem frame characterises a class of simple problem. Realistic problems are seen as compositions of simple problems of recognised classes corresponding to known frames.

M. A. Jackson

1999-01-01

425

Doctors' involvement in torture.  

PubMed

Doctors from both non-democratic and democratic countries are involved in torture. The majority of doctors involved in torture are doctors at risk. Doctors at risk might compromise their ethical duty towards patients for the following possible reasons: individual factors (such as career, economic or ideological reasons), threats, orders from a higher ranking officer, political initiatives, working in atrocity-producing situations or dual loyalty. In dual loyalty conflicts, factors that might compromise doctors' ethical obligations towards detainees/patients are: ideological totalitarianism, moral disengagement, victim blame, patriotism, individual factors or threats. Another important reason why doctors are involved in torture is that not all doctors are trained in addressing human rights issues of detainees. Torture survivors report that they have experienced doctors' involvement in torture and doctors themselves report that they have been involved in torture. Testimonies from both torture survivors and doctors demonstrate that the most common way doctors are involved is in the diagnosis/medical examination of torture survivors/prisoners. And it is common before, during and after torture. Both torture survivors and doctors state that doctors are involved during torture by treatment and direct participation. Doctors also falsify journals, certificates and reports. When doctors are involved in torture it has devastating consequences for both torture survivors and doctors. The consequences for the survivors can be mistrust of doctors, avoidance of seeking doctors' help and nightmares involving doctors. Mistrust and avoidance of doctors could be especially fatal to the survivor, as it could mean a survivor who is ill may not seek medical attention. When the unambiguous role of the doctor as the protector and helper of people is questioned, it affects the medical profession all over the world. PMID:19491477

Jesper, Sonntag

2008-01-01

426

Treatment of alcohol problems.  

PubMed

This paper gives an overview of the variety of approaches that have been used in the treatment of alcohol problems. There is good evidence that approaches directed at improving social and marital relationships, self-control and stress management are effective. There is at present little to suggest that aversion therapies, confrontational interventions, educational lectures or films and group psychodynamic therapy are effective, nor is there good evidence yet that use of psychotropic medications is effective. However, it may be that therapies that have not proved effective with the broad range of individuals with alcohol problems might prove effective with selected cases. Future research should place more emphasis on determining the kinds of alcohol problems that are likely to respond to different kinds of treatments directed at different kinds of goals and by different kinds of practitioners. The base of treatment should be broadened to include the large numbers of individuals with alcohol problems but who could not be considered as alcohol-dependent. This would have to involve a wide range of primary care and generic workers and include use of brief interventions. PMID:7841867

Hodgson, R

1994-11-01

427

Halton sampling for autofocus.  

PubMed

Reliable autofocusing is a critical part of any automated microscopy system: by precisely positioning the sample in the focal plane, the acquired images are sharp and can be accurately segmented and quantified. The three main components of an autofocus algorithm are a contrast function, an optimization algorithm and a sampling strategy. The latter has not been given much attention in the literature. It is however a very important part of the autofocusing algorithm, especially in high content and high throughput image-based screening. It deals with the problem of sampling the focus surface as sparsely as possible to reduce bleaching and computation time while with sufficient detail as to permit a faithful interpolation. We propose a new strategy that has higher performance compared to the classical square grid or the hexagonal lattice, which is based on the concept of low discrepancy point sets and in particular on the Halton point set. We tested the new algorithm on nine different focus surfaces, each under 24 different combinations of Signal-to-Noise ratio (SNR) and sampling rate, obtaining that in 88% of the tested conditions, Halton sampling outperforms its counterparts. PMID:19566626

Pengo, T; Muñoz-Barrutia, A; Ortiz-De-Solórzano, C

2009-07-01

428

Cerebellar involvement in executive control.  

PubMed

The cerebellum has long been considered to be mainly involved in motor function. In the last 20 years, evidence from neuroimaging studies and from investigations of patients with cerebellar lesions has shown that the cerebellum plays a role in a range of cognitive functions. While cerebellar contributions have been shown for learning and memory, the cerebellum has also been linked to higher order cognitive control processes frequently referred to as executive functions. Although it is widely accepted that the cerebellum contributes to cognitive processing, the nature of cerebellar involvement is not well understood. The present paper focuses on the role of the cerebellum in executive processing, reviewing findings derived from neuroimaging studies or from studies investigating deficits related to cerebellar dysfunction. As executive functions cannot be considered as a unitary concept, special emphasis is put on cerebellar contributions to different aspects of executive control such as working memory, multitasking or inhibition. Referring to models derived from motor control, possible mechanisms of cerebellar involvement in executive processing are discussed. Finally, methodological problems in assessing executive deficits in general and in assessing the cerebellar contribution to executive processing in particular are addressed. PMID:17786814

Bellebaum, Christian; Daum, Irene

2007-01-01

429

Home Fires Involving Grills  

MedlinePLUS

... Fire Analysis & Research Division, osds@nfpa.org Home Fires Involving Grills Fact Sheet In 2006-2010, U.S. ... being too close to the grill. Home Grill Fires by Leading Areas of Origin 2006-2010 More ...

430

Management of foreskin problems.  

PubMed Central

One hundred consecutive cases of boys with foreskin problems referred to local paediatric surgeons in the Edinburgh area were studied. Fifty five underwent circumcision and the remainder were managed more conservatively with or without the use of local or general anaesthetic. Although sometimes avoiding general anaesthetic, the more conservative methods involved more frequent visits to the clinic, a larger number of complications, and a longer follow up period. Despite the vogue for conservatism, circumcision still has an important part to play in the management of troublesome foreskins in children.

Lafferty, P M; MacGregor, F B; Scobie, W G

1991-01-01

431

Principles for Sampling Airborne Radioactivity from Stacks  

SciTech Connect

This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

Glissmeyer, John A.

2010-10-18

432

The Yo-Yo Problem  

NSDL National Science Digital Library

In this math lesson, learners explore linear patterns, write a pattern in symbolic form, and solve linear equations using algebra tiles, symbolic manipulation, and a graphing calculator. The lesson begins with the presentation of the yo-yo problem. Then learners complete a hands-on activity involving a design created with pennies. Algebra tiles are introduced next as learners practice solving linear equations. Finally, learners return to solving the yo-yo problem.

Pbs

2012-01-01

433

Combined Relaxation Method for Mixed Equilibrium Problems  

Microsoft Academic Search

We consider a general class of equilibrium problems which involve a single-valued mapping and a nonsmooth bifunction. Such mixed equilibrium problems are solved with a combined relaxation method using an auxiliary iteration of a splitting-type method for constructing a separating hyperplane. We prove the convergence of the method under the assumption that the dual of the mixed equilibrium problem is

I. V. Konnov; S. Schaible; J. C. Yao

2005-01-01

434

Optimal design, inverse problems and parallel computers  

Microsoft Academic Search

Speed has always been a problem in the application of inverse problem methodology in optimal design. This is largely due to the time-consuming operations involved in the computation of gradients with respect to the many parameters. With the advent of parallel computers, this is no longer a problem. The conjugate gradient and Cholesky factorization solution procedures for the computation of

S. R. H. Hoole

1991-01-01

435

Sample support in a single fracture: Considering the definition and control of the support of a water sample  

NASA Astrophysics Data System (ADS)

Defining and controlling the support of a field measurement (the volume or area over which the measurement is averaged) are critical components of statistical and/or geostatistical analysis of a data base. For the present study, the seemingly simple task of collecting a water sample from a single fracture is used to illustrate potential difficulties in defining and controlling the support of that sample. Two definitions of sample support are considered for this problem. First, one could argue that the support is equal to the volume of water collected. Second, one could argue for a support defined in terms of the area of the fracture surface contacted by the water collected. Collection of water samples with constant volume is relatively straight forward in a field situation. Collection of a water sample which involves contact with a specified area of the fracture, however, is not as straight forward. In the case of negligible regional flow, a constant sample area can be approximated by requiring that the sample volume collected be linearly proportional to the locally averaged aperture (thus requiring an independent measure of the local aperture). In the case of regional flow with continuous sampling, a constant area within each sample can be approximated by matching the up gradient width of the capture zone of the sampler (thus requiring knowledge of the local aperture and hydraulic gradient). These examples illustrate how difficult it may be to define and control the support for even these simple measurements. Further, they illustrate that the choice of support may be closely related to the purpose for which the measurement is collected. Additional attention to the problem of defining / controlling sample supports has the potential to pay substantial dividends in the areas of scaling and field design / analysis.

Silliman, Stephen E.

436

Relationships with Adults as Predictors of Substance Use, Gang Involvement, and Threats to Safety among Disadvantaged Urban High-School Adolescents  

ERIC Educational Resources Information Center

Using a resilience framework, the authors examined the protective effects of parental support, self-disclosure to parents, parent-initiated monitoring of adolescent behavior, and relationships with school personnel on three critical problems of adolescents: substance use, gang involvement, and perceived threats to safety at school. The sample

Ryan, Linda G.; Miller-Loessi, Karen; Nieri, Tanya

2007-01-01

437

New faculty involvement for women and minorities  

Microsoft Academic Search

I used variations of Astin's involvement model to guide a study of four cohorts of women and minorities as new faculty: two groups from a comprehensive university and two of them from a research campus. The two least demanding levels of inquiry for both interviewer and interviewee—unstructured and structured—provided rich descriptions of disappointments, problems, and values that distinguished nontraditional new

Robert Boice

1993-01-01

438

Facilitating Staff Involvement in Implementing Appropriate Interventions  

ERIC Educational Resources Information Center

The need for a Learning Facilitation Team is described which cooperatively works to find solutions for the problems presented by specific students. The team is also charged with the responsibility of encouraging total staff involvement to build a total school plan for helping students. (Author)

Catterall, Calvin D.

1978-01-01

439

Sample Sizes for Usability Studies: Additional Considerations  

Microsoft Academic Search

ABSTRACT Recently, Virzi (1992) presented data that support three claims regarding sample sizes for usability studies. The claims were (1) observing four or five participants will allow a usability practitioner to discover 80% of a product's usability problems, (2) observing additional participants will reveal fewer and fewer new usability problems, and (3) more severe usability problems are easier to detect

James R. Lewis

440

Analytic Solutions of Elastic Tunneling Problems  

Microsoft Academic Search

The complex variable method for solving two dimensional linearly \\u000aelastic problems is used to obtain several fundamental analytical \\u000asolutions of tunneling problems. The method is used to derive the \\u000ageneral mathematical representation of problems involving \\u000aresultant forces on holes in a half-plane. Such problems are \\u000aencountered in geomechanics during the excavation of tunnels. \\u000aWhen tunnels are excavated the removal of

O. E. Strack

2002-01-01

441

Gang Involvement and Membership among Homeless and Runaway Youth.  

ERIC Educational Resources Information Center

Assessed the extent of gang involvement among homeless and runaway youth, comparing gang members, gang-involved youth (not members), and non-gang youth on several dimensions. Interview data indicated that 15.4 percent of the youth were gang members and 32.2 percent were involved in gangs. These youth reported more family problems and school…

Yoder, Kevin A.; Whitbeck, Les B.; Hoyt, Dan R.

2003-01-01

442

Direct qPCR quantification of unprocessed forensic casework samples.  

PubMed

The current short tandem repeat (STR) typing workflow for forensic casework samples involves sample collection, sample screening, DNA extraction, DNA qPCR quantification and STR amplification. Although very effective and powerful, this workflow still has room for improvements. For example, the screening assays in practice do not provide DNA related information and also do not work with touch DNA samples, which make up of the majority of the property crime samples. It is known that not all DNA samples have equal probative values. Considering the DNA backlog situation crime laboratories face today, an effective screening tool would be highly desirable. It would allow forensic scientists to prioritize the DNA samples so that the limited resources would be first spent on samples that would have better chances of producing informative STR profiles. qPCR assay does provide DNA quantity and gender information and would be an ideal screening tool. However, prior to quantification, sample extraction and purification are required. By the time a DNA sample is ready for qPCR quantification, time and resources have already been spent on samples that should have been given low priority or excluded from further processing if DNA quantity and gender information were known. To overcome this problem, a direct quantification technology is developed to allow qPCR quantification of casework samples without the need for DNA extraction and purification. The key to a direct qPCR assay is the PE-Swab, a novel sample collection device. A small sample punch can be generated from a PE-Swab and placed in a qPCR reaction for quantification. After optimizing the punch size and the quantification software baseline setting, accurate DNA quantification can be obtained from a sample without the need to carry out DNA extraction and purification. Proof of concept studies were done with low lever touch samples as well as blood samples. The PE-Swab also allows direct STR amplification of casework samples without the need for DNA extraction. Besides its potential as a screening tool, the direct qPCR assay can also be used to normalize the DNA input for a direct STR amplification reaction. The feasibility of the direct qPCR/direct STR amplification workflow was demonstrated with touch DNA samples and blood stain samples. PMID:24705062

Liu, Jason Yingjie

2014-07-01

443

INVOLVING COMMUNITY AND PARENTS.  

ERIC Educational Resources Information Center

THE FIRST PAPER OF A PANEL, BY AARON BROWN, BRIEFLY REVIEWS SOME ISSUES OF PARENT-COMMUNITY INVOLVEMENT IN THE SCHOOLS. HE NOTES THE INCREASING COMMUNITY CONCERN WITH BETTER TEACHER PREPARATION AND PERFORMANCE, QUALITY INTEGRATED EDUCATION, AND VARIOUS CURRENT EDUCATIONAL STRATEGIES AND PRACTICES. HE POINTS OUT THAT THE PRINCIPAL IS THE KEY TO THE…

SHAPIRO, ELLIOT; AND OTHERS

444

Getting Parents Involved.  

ERIC Educational Resources Information Center

Describes a parental involvement program in reading, writing, and human education. The project consists of caring for Clifford, a stuffed toy dog, on a rotated basis by first grade students. Books and pet care items accompany Clifford and provide an opportunity for parent and child to work together. (ML)

Butts, Vickie; Finch, Patty A.

1985-01-01

445

Involvement or Engagement?  

ERIC Educational Resources Information Center

To create the kinds of school-family partnerships that raise student achievement, improve local communities, and increase public support, schools need to understand the difference between family involvement and family engagement. Schools that emphasize the latter tend toward doing with families, rather than doing to families. These schools do more…

Ferlazzo, Larry

2011-01-01

446

Acceptance sampling using judgmental and randomly selected samples  

SciTech Connect

We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

2010-09-01

447

Future Lunar Sampling Missions: Big Returns on Small Samples  

NASA Astrophysics Data System (ADS)

The next sampling missions to the Moon will result in the return of sample mass (100g to 1 kg) substantially smaller than those returned by the Apollo missions (380 kg). Lunar samples to be returned by these missions are vital for: (1) calibrating the late impact history of the inner solar system that can then be extended to other planetary surfaces; (2) deciphering the effects of catastrophic impacts on a planetary body (i.e. Aitken crater); (3) understanding the very late-stage thermal and magmatic evolution of a cooling planet; (4) exploring the interior of a planet; and (5) examining volatile reservoirs and transport on an airless planetary body. Can small lunar samples be used to answer these and other pressing questions concerning important solar system processes? Two potential problems with small, robotically collected samples are placing them in a geologic context and extracting robust planetary information. Although geologic context will always be a potential problem with any planetary sample, new lunar samples can be placed within the context of the important Apollo - Luna collections and the burgeoning planet-scale data sets for the lunar surface and interior. Here we illustrate the usefulness of applying both new or refined analytical approaches in deciphering information locked in small lunar samples.

Shearer, C. K.; Borg, L.

2002-01-01

448

Complex Problem Solving: Identity Matching Based on Social Contextual Information  

Microsoft Academic Search

Complex problems like drug crimes often involve a large number of variables interacting with each other. A complex problem may be solved by breaking it into parts (i.e., sub-problems), which can be tackled more easily. The identity matching problem, for example, is a part of the problem of drug and other types of crimes. It is often encountered during crime

Jennifer Jie Xu; G. Alan Wang; Jiexun Li; Michael Chau

2007-01-01

449

Complex Problem Solving: Identity Matching Based on Social  

Microsoft Academic Search

Complex problems like drug crimes often involve a large number of variables interacting with each other. A complex problem may be solved by breaking it into parts (i.e., sub-problems), which can be tackled more easily. The identity matching problem, for example, is a part of the problem of drug and other types of crimes. It is often encountered during crime

Jennifer Xu; Jiexun Li; Michael Chau

450

Grasers: proposals, problems, and prospects  

SciTech Connect

The possibility and potentiality of amplification of recoilless radiation emitted by nuclear isomers has long been recognized; nevertheless, development of gamma-ray lasers continues to await resolution of the pumping vs. linebreadth dilemma. Problems that accompany proposals for reducing the excitation requirements and suggest areas of investigation that may contribute to resolving the dilemma are identified; several involve use of optical lasers.

Baldwin, G.C.

1982-01-01

451

Modeling for Moving Boundary Problems.  

National Technical Information Service (NTIS)

The classical problems in partial differential equations involve solving an equation within a fixed spatial region. However, when attempting to model such phenomena as melting and freezing, we find that as time varies the region in which, e.g., material i...

A. D. Solomon

1979-01-01

452

Community prevention of alcohol problems  

Microsoft Academic Search

Local communities have begun using policy to affect the drinking environment itself as an approach to reducing alcohol involved trauma. That is, policy is used to produce structural changes in the drinking environment. In turn, changes in the environment effect changes in drinking behavior. This paper describes an effort in three communities in two states to reduce alcohol problems at

Harold D Holder

2000-01-01

453

The Relationship Between Post-Traumatic Stress Symptoms and Substance Use Among Adolescents Involved with Child Welfare: Implications for Emerging Adulthood  

Microsoft Academic Search

The purpose of the present study was to examine the role of posttraumatic stress symptoms (PTSS) in predicting substance use\\u000a and substance-related problems in a sample of older youth and emerging adults involved with child welfare. The sample was\\u000a drawn from the Maltreatment and Adolescent Pathways (MAP) longitudinal study (Wekerle et al. 2009). Participants were 253 youth and emerging adults

Abby L. Goldstein; Christine Wekerle; Lil Tonmyr; Tiffany Thornton; Randall Waechter; Jessica Pereira; Ronald Chung

454

Quantum Metropolis sampling.  

PubMed

The original motivation to build a quantum computer came from Feynman, who imagined a machine capable of simulating generic quantum mechanical systems--a task that is believed to be intractable for classical computers. Such a machine could have far-reaching applications in the simulation of many-body quantum physics in condensed-matter, chemical and high-energy systems. Part of Feynman's challenge was met by Lloyd, who showed how to approximately decompose the time evolution operator of interacting quantum particles into a short sequence of elementary gates, suitable for operation on a quantum computer. However, this left open the problem of how to simulate the equilibrium and static properties of quantum systems. This requires the preparation of ground and Gibbs states on a quantum computer. For classical systems, this problem is solved by the ubiquitous Metropolis algorithm, a method that has basically acquired a monopoly on the simulation of interacting particles. Here we demonstrate how to implement a quantum version of the Metropolis algorithm. This algorithm permits sampling directly from the eigenstates of the Hamiltonian, and thus evades the sign problem present in classical simulations. A small-scale implementation of this algorithm should be achievable with today's technology. PMID:21368829

Temme, K; Osborne, T J; Vollbrecht, K G; Poulin, D; Verstraete, F

2011-03-01

455

Solving Probability Problems Using Monte Carlo Simulation.  

ERIC Educational Resources Information Center

Described is a strategy that allows students to experiment with probability without applying formulas to solve problems. Students are able to intuitively develop concepts of probability before formal definitions and properties. Sample problems are included along with BASIC programs for some of the problems. (KR)

Rudolph, William B.; Tvrdik, Debra

1991-01-01

456

Electrostatic interactions with dielectric samples in scanning probe microscopies  

NASA Astrophysics Data System (ADS)

Electrostatic interactions between the conducting tip of a scanning probe microscope and a flat conductor coated with a thin or thick dielectric layer are treated analytically and numerically. Exact and compact approximate expressions for the capacitance, force, force gradient, electric field profiles, and their effective widths are derived for a spherical model tip by generalizing known solutions for the conducting sphere and sample problem. These expressions allow convenient modeling of various measurements involving voltage-biased probes, estimation of lateral resolution, and prediction of trends as a function of relevant parameters.

Sadeghi, Ali; Baratoff, Alexis; Goedecker, Stefan

2013-07-01

457

Approximate Small-Sample Distributions for Multivariate Two-Sample Nonparametric Tests.  

National Technical Information Service (NTIS)

There has been much recent interest in multivariate, nonparametric procedures with major emphasis on their asymptotic properties. The multivariate, two-sample problem is considered in this paper with particular interest in small-sample applications. The c...

K. M. Patel R. A. Bradley

1967-01-01

458

SST Sample Characterization Analysis of Archive Samples 102-C, 105-C, and 106-C  

SciTech Connect

A substantial effort is planned to be initiated at the Hanford Site regarding the characterization of 149 single-shell tanks (SSTs) containing the byproducts of reprocessing during the 1950s and 1960s. Sampling and analysis, in distinct phases, are planned to involve laboratory investigations to determine both chemical and radionuclide inventories, so that waste disposal decisions can be developed. During 1989, trial analyses were performed on four archived samples from SSTs at the Pacific Northwest Laboratory using established U.S. Environmental Protection Agency (EPA) protocols and radiochemical procedures. The analysis of the archived SST waste material provides three important types of data for use in planning Phase I-A and Phase 1-B sample analysis. The types of data served as input to I) fi na 1 i zing the waste samp 1 e analysis procedures and methods and identify where procedure developmen~ may be needed, 2) evaluating the impact of normal paraffin hydrocarbon (NPH) lubricant {used in field sampling) on extracting inorganics or radionuclides from the SST sample, and 3) identifying trends in amounts of occupational radiation exposure expected from performing the various analysis procedures. Overall, the results are qualitative in nature, and the conclusions given are to be used with appropriate respect for the limitations of small amounts of data from four samples used in development processes. The results of the Phase I-A and I-B sample analysis will provide essential data for method performance for use in finalizing Phase I-C planning and methods development scope. Section 2.0, Inorganic Analysis, encompasses sample preparation, sample analysis, identification of methods performance limitations, and possible alternatives. Performance of the inorganic analytical methods was evaluated and changes were made to some of the procedures. In some cases, inductively coupled plasma-atomic emission spectroscopy (referred to in this report as ICP) did not provide the levels of accuracy and precision usually required for EPA work due to interference by other elements. In these cases, other methods are suggested as appropriate for trial as alternatives. In all cases, duplicates, spikes, and blanks were used to establish performance of the methods for the specific waste matrix. Results focused on problems in using the methods tested on the samples, the suitability of the ICP method of determining EP Toxicity metal ions and 22 EPA pollutant metal ions, and the suitability of cold vapor atomic absorption (CVAA) for mercury determinations. Problems areas identified are ICP spectral corrections, poor reproducibility from water leach and EP Toxicity methods, and adjustments needed for mercury analysis by CVAA. Section 3.0, Organics Analysis, details two screening procedures [total organic carbon (TOC) and gas chromatography (GC)], extraction procedures and related problems, surrogate spiking to test extraction efficiencies and matrix effects, and semivolatile organics via GC/mass spectroscopy (MS). The results show that the GC/MS is vulnerable to fouling and overload and that a combination of dilution and perhaps acidification are required to provide acceptable results. NPH and silicone-based lubricants from the sampling process impact the semivolatile analysis; however, with some modification the semivolatile method based on EPA SOW 288 can be used. Section 4.0, Radionuclide Analysis, evaluates procedures used to measure the radionuclides that might be found in the SST tank waste samples and establishes the level of accuracy and precision that can be expected. These data reveal that additional procedure development is needed in order to measure all of the radionuclides listed in Table 4-14 of the Waste Characterization Plan. In addition, the archive samples analyzed may not be representative of the tank population and considerable adaptation of the radiochemical procedures may be necessary to perform the desired measurements. NPH tests were conducted to determine whether the NPH from the field sampling process extracted significan

Hara, F. T.; Kaye, J. H.; Steele, R. T.; Stromatt, R. W.; Thomas, D. L.; Urie, M. W.

1990-04-01

459

Estimation problems in rainfall modeling  

NASA Astrophysics Data System (ADS)

A special session entitled “Estimation Problems in Rainfall Modeling” was held during the 1985 AGU Fall Meeting in San Francisco, Calif. The session was chaired by Witold F. Krajewski of the Hydrologic Research Laboratory of the National Weather Service (NWS), Silver Spring, Md. The purpose of the session was to bring together researchers interested in a wide range of rainfall-related estimation problems, such as parameter estimation, state estimation, multiple sensor rainfall analysis, and estimation problems in rainfall simulation. The topics of papers presented at the session included parameter estimation of point process models, errors in radar rainfall observations, and sampling aspects of space-state representation of rainfall.

Krajewski, Witold F.; Georgakakos, Konstantine P.

460

Clinical studies involving probiotics  

PubMed Central

Researchers from a diverse array of scientific disciplines have focused and continue to focus on opportunities and areas for responsible clinical research involving the possible beneficial health effects of “probiotics.” Investigators and researchers should be aware that not all clinical research involving probiotics reasonably falls within the requirements of the “investigational new drug” (IND) rubric administered and enforced by the US Food and Drug Administration. In determining whether an IND application is required before a clinical study may lawfully commence, investigators and researchers as well as institutional review boards should consider the regulatory classification, e.g., “drug,” “new drug,” “food,” “food additive,” “dietary supplement,” etc. that applies to the substance under investigation. A potential probiotic product can fall along a continuum of regulatory classifications, each having implications on the nature and degree of regulatory requirements for clinical research and, ultimately, for claim substantiation and market access.

Degnan, Fred H.

2012-01-01

461

Rock Samples and Geochemistry Analyses  

NSDL National Science Digital Library

In this lab set students use field work to collect a granite sample which will be prepared for whole-rock analyses through ICP-AES, AAS, and XRF methodologies, as well as mineral concentrations and thin sections for microprobe. The bulk of these exercices involve sample and data manipulation and also include some open-ended questions as comparisons between mineral and whole-rock composition, different kind of data presentation in geochemistry, and limitations and applicability of distinct analytical methodologies.

Lourdes, Maria R.

462

Beta approximations for bridge sampling  

Microsoft Academic Search

We consider the problem of simulating X conditional on the value of X +Y , when X and Y are independent positive random variables. We propose approximate methods for sampling (X|X+Y) by approximating the fraction (X\\/z|X+ Y = z) with a beta random variable. We discuss applications to Levy processes and infinitely divisible distributions, and we report numerical tests for

Paul Glasserman; Kyoung-kuk Kim

2008-01-01

463

Improved sample size determination for attributes and variables sampling  

SciTech Connect

Earlier INMM papers have addressed the attributes/variables problem and, under conservative/limiting approximations, have reported analytical solutions for the attributes and variables sample sizes. Through computer simulation of this problem, we have calculated attributes and variables sample sizes as a function of falsification, measurement uncertainties, and required detection probability without using approximations. Using realistic assumptions for uncertainty parameters of measurement, the simulation results support the conclusions: (1) previously used conservative approximations can be expensive because they lead to larger sample sizes than needed; and (2) the optimal verification strategy, as well as the falsification strategy, are highly dependent on the underlying uncertainty parameters of the measurement instruments. 1 ref., 3 figs.

Stirpe, D.; Picard, R.R.

1985-01-01

464

Sample Allocation for Stratified Telephone Sample Designs.  

National Technical Information Service (NTIS)

Stratified telephone sample designs have been proposed which provide samples of phone numbers that have high concentrations of working residential telephone numbers but require little replacement sampling. These designs use commercial lists of telephone n...

C. Tucker R. Casady

1992-01-01

465

Auxiliary problems and algorithm for a system of generalized variational-like inequality problems  

Microsoft Academic Search

In this paper, we consider a system of generalized variational-like inequality problems (SGVLIP) involving nondifferentiable terms, and its related auxiliary problems in real Hilbert spaces. An existence theorem for auxiliary problems is established. Further, by exploiting this theorem, an algorithm for the SGVLIP is constructed. Furthermore, we prove the existence of a unique solution of SGVLIP and discuss the convergence

K. R. Kazmi; F. A. Khan

2007-01-01

466

An approach to wicked problems in environmental policy making  

Microsoft Academic Search

A bstract: - In environmental policy making, the objectives are part of the decision-making problem. Policy making for sustainable development involves problems with lack of clear and definitive problem formulation which are to be solved by various stakeholders who judge the solutions with different values. In addition, risks and uncertainties involving future events and risks and uncertainties associated to the

NASSER AYOUB; RAFAEL BATRES; YUJI NAKA

467

NEUMANN-NEUMANN METHODS FOR VECTOR FIELD PROBLEMS  

Microsoft Academic Search

In this paper, we study some Schwarz methods of Neumann-Neumann type for some vector field problems, discretized with the lowest order Raviart-Thomas and Ned´ elec finite elements. We consider a hybrid Schwarz preconditioner consisting of a coarse component, which involves the solution of the original problem on a coarse mesh, and local ones, which involve the solution of Neumann problems

ANDREA TOSELLI

2000-01-01

468

AEROSOL SAMPLING INLETS AND INHALABLE PARTICLES  

EPA Science Inventory

The problem of sampling aerosols from the ambient atmosphere has been considered from a theoretical point of view. Following a review of the various samplers and inlets used in ambient sampling, the factors contributing to high sampling efficiency for large particles are discusse...

469

Encouraging Meaningful Quantitative Problem Solving  

NASA Astrophysics Data System (ADS)

Quantitative problem-solving is a challenging aspect of any physical science course. Traditionally, students have been encouraged to pursue various techniques in an effort to provide structure to this task. While such methods may help students to generate numerical answers, they can become exercises in symbol manipulation that leave the student without a clear picture of the physical situation associated with the problem. This paper describes the efforts of a group of teachers to help college freshman chemistry students and high school science students to improve their problem-solving skills. The presentation includes several sets of questions intended to elucidate ideas and to involve the reader in the process of reflecting upon his or her own problem-solving strategies.

Cohen, Jeff; Kennedy-Justice, Meghan; Pai, Sunny; Torres, Carmen; Toomey, Rick; Depierro, Ed; Garafalo, Fred

2000-09-01

470

Physics Suite Peer Instruction Problems: Kinematics  

NSDL National Science Digital Library

This website contains a series of peer instruction problems on kinematics, designed to be solved in a classroom setting. The problems are presented with a qualitative (usually multiple choice) question that is carefully constructed to engage student difficulties with fundamental concepts. Students consider the problem individually and contribute their answers using personal response systems (clickers). Students then confer with their cooperative groups and vote again on the correct response. Topics covered include displacement, velocity, average velocity, speed, and interpreting position and velocity graphs. This problem set is part of the Physics Suite collection, containing sample problems, peer instruction problems, and alternative homework sets.

Redish, Edward F.

2008-08-11

471

Physics Suite Peer Instruction Problems: Dynamics  

NSDL National Science Digital Library

This website contains a series of peer instruction problems on dynamics, designed to be solved in a classroom setting. The problems are presented with a qualitative (usually multiple choice) question that is carefully constructed to engage student difficulties with fundamental concepts. Students consider the problem individually and contribute their answers using personal response systems (clickers). Students then confer with their cooperative groups and vote again on the correct response. Topics covered include force, acceleration, normal force, friction, tension, and motion in two dimensions. This problem set is part of the Physics Suite collection, containing sample problems, peer instruction problems, and alternative homework sets.

Redish, Edward F.

2008-08-11

472

STACK SAMPLING FOR ORGANIC EMISSIONS  

EPA Science Inventory

The paper reviews some of the more important principles involved in stack sampling for organics, briefly describes and discusses recently developed equipment, and points out a few of the more serious pitfalls. Extensive references are provided, many of which are often overlooked ...

473

Optimal Sampling Plans for Items Representing Two Population Groups.  

National Technical Information Service (NTIS)

This paper examines a problem of determining optimal sampling plans. The items to be sampled belong to two distinct populations which are partitioned into sub-populations that require sampling plans. Three mathematical programming models are investigated ...

R. S. Wendell

1992-01-01

474

Analysis of a Dynamic Project Cost Problem.  

National Technical Information Service (NTIS)

A stochastic allocation model for a sequential financial problem involving the allocation of funds to uncertain future payments is presented. It is shown that under certain conditions the optimal allocation policies are piecewise linear with the budget av...

A. Mehrez, M. Sniedovich

1983-01-01

475

Fifty Environmental Problems of Timely Importance.  

National Technical Information Service (NTIS)

The paper surveys some of the most recognizable and pressing problems of the environment, and includes comments on them from the current literature. Topics include short articles on pollution involving SST and stratospheric air force planes, Heat, DDT, Ai...

L. M. Libby

1970-01-01

476

Sample Size Calculation for Estimating or Testing a Nonzero Squared Multiple Correlation Coefficient  

Microsoft Academic Search

The problems of hypothesis testing and interval estimation of the squared multiple correlation coefficient of a multivariate normal distribution are considered. It is shown that available one-sided tests are uniformly most powerful, and the one-sided confidence intervals are uniformly most accurate. An exact method of calculating sample size to carry out one-sided tests (null hypothesis may involve a nonzero value

K. Krishnamoorthy; Yanping Xia

2008-01-01

477

Importance Sampling for Dispersion-Managed Solitons  

NASA Astrophysics Data System (ADS)

The dispersion-managed nonlinear Schrödinger (DMNLS) equation governs the long-term dynamics of systems which are subject to large and rapid dispersion variations. We present a method to study large, noise-induced amplitude and phase perturbations of dispersion-managed solitons. The method is based on the use of importance sampling to bias Monte Carlo simulations toward regions of state space where rare events of interest -- large phase or amplitude variations -- are most likely to occur. Implementing the method thus involves solving two separate problems: finding the most likely noise realizations that produce a small change in the soliton parameters, and finding the most likely way that these small changes should be distributed in order to create a large, sought-after amplitude or phase change. Both steps are formulated and solved in terms of a variational problem. In addition, the first step makes use of the results of perturbation theory for dispersion-managed systems recently developed by the authors. We demonstrate this method by reconstructing the probability density function of amplitude and phase deviations of noise-perturbed dispersion-managed solitons and comparing the results to those of the original, unaveraged system.

Spiller, Elaine T.; Biondini, Gino

2010-01-01

478

Drug-Related Problems And the Physician: The Calgary Experience  

PubMed Central

Experiences of a sample of Calgary physicians treating drug-related problems are described. Family physicians and specialists are compared on number of cases seen, by type of drug problems. Difficulties in treating or managing people with such problems, suggestions for overcoming difficulties, suggestions for improving treatment and prevention of drug-related problems in Calgary, and attitudes toward such problems are also reported.

Rootman, Irving

1973-01-01

479

Research problems in clinical diagnosis  

Microsoft Academic Search

Based on experiences in reviewing journal manuscripts and in working with published literature, the author discusses several methodological inadequacies that frequently occur in research reports dealing with the assessment, diagnosis, comparison, or categorization of individuals being appraised or studied for clinical purposes. Among the methodological problems encountered are sampling errors, inappropriate control groups, confusion of clinical and statistical significance, inadequate

Sol L. Garfield

1978-01-01

480

Superlinear Ambrosetti-Prodi Problem.  

National Technical Information Service (NTIS)

This paper establishes the existence of two solutions for some problems of the Ambrosetti-Prodi type. The following result is a sample of the results. The author uses the method of monotone iterations to obtain the first solution and a variational argumen...

D. G. de Figueiredo

1983-01-01