Sample records for current study sample

  1. Results from a Survey of Current Practices for Sampling of Nervous System in Rodents and Non-rodents in General Toxicity Studies

    EPA Science Inventory

    A survey of current practices for sampling and examination of the nervous system in rodents and non-rodents for general and neurotoxicity (NT) studies was conducted by the Nervous System Sampling Subcommittee of the STP. For general toxicity studies most of those surveyed (>63%) ...

  2. Effects of Electrical Current and External Stress on the Electromigration of Intermetallic Compounds Between the Flip-Chip Solder and Copper Substrate

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Jhen; Lee, Yue-Lin; Wu, Ti-Yuan; Chen, Tzu-Ching; Hsu, Chih-Hui; Lin, Ming-Tzer

    2018-01-01

    This study investigated the effects of electric current and external stress on electromigration of intermetallic compounds (IMC) between solder and copper substrate. Different samples were tested under three different sets of conditions: (1) thermal aging only, (2) thermal aging with electric current ,where resistivity changes were measured using four-point probe measurements, (3) thermal aging with electric current and external stress provided using a four-point bending apparatus. The micro-structural changes in the samples were observed. The results were closely examined; particularly the coupling effect of electric current and external stress to elucidate the electromigration mechanism, as well as the formation of IMC in the samples. For thermal-aging-only samples, the IMC growth mechanism was controlled by grain boundary diffusion. Meanwhile, for thermal aging and applied electric current samples, the IMC growth mechanism was dominated by volume diffusion and interface reaction. Lastly, the IMC growth mechanism in the electric current and external stress group was dominated by grain boundary diffusion with grain growth. The results reveal that the external stress/strain and electric current play a significant role in the electromigration of copper-tin IMC. The samples exposed to tensile stress have reduced electromigration, while those subjected under compressive stress have enhanced electromigration.

  3. Evaluation of standardized sample collection, packaging, and ...

    EPA Pesticide Factsheets

    Journal Sample collection procedures and primary receptacle (sample container and bag) decontamination methods should prevent contaminant transfer between contaminated and non-contaminated surfaces and areas during bio-incident operations. Cross-contamination of personnel, equipment, or sample containers may result in the exfiltration of biological agent from the exclusion (hot) zone and have unintended negative consequences on response resources, activities and outcomes. The current study was designed to: (1) evaluate currently recommended sample collection and packaging procedures to identify procedural steps that may increase the likelihood of spore exfiltration or contaminant transfer; (2) evaluate the efficacy of currently recommended primary receptacle decontamination procedures; and (3) evaluate the efficacy of outer packaging decontamination methods. Wet- and dry-deposited fluorescent tracer powder was used in contaminant transfer tests to qualitatively evaluate the currently-recommended sample collection procedures. Bacillus atrophaeus spores, a surrogate for Bacillus anthracis, were used to evaluate the efficacy of spray- and wipe-based decontamination procedures.

  4. Generation of mechanical vibrations in metal samples by the use of the pinch effect

    NASA Astrophysics Data System (ADS)

    Troitskiy, O. A.; Skvortsov, O. B.; Stashenko, V. I.

    2017-07-01

    The article presents the recent research in electrodynamic processes for metal samples exposed to current pulses. The pinch effect and the skin effect cause the vibration of the metal rods. The results of these studies show how current and magnetic field interact with material samples of gold, silver and copper. The analysis allowed establishing the dependences of peak acceleration on current density and conductor diameter. The dependencies can be used in metal workings and for nondestructive testing.

  5. Effect of the electrical currents generated by the intestinal smooth muscle layers on pancreatic enzyme activity: an in vitro study.

    PubMed

    Dabek, Marta; Podgurniak, Paweł; Piedra, Jose L Valverde; Szymańczyk, Sylwia; Filip, Rafał; Wojtasz-Pajak, Anna; Werpachowska, Eliza; Podgurniak, Malgorzata; Pierzynowski, Stefan G

    2007-05-01

    Gut enzymes in the small intestine are exposed to extremely low electrical currents (ELEC) generated by the smooth muscle. In the present study, the in vitro tests were undertaken to evaluate the effect of these electric currents on the activity of the proteolytic pancreatic digestive enzymes. A simulator generating the typical electrical activity of pig gut was used for these studies. The electric current emitted by the simulator was transmitted to the samples, containing enzyme and its substrate, using platinum plate electrodes. All samples were incubated at 37 degrees C for 1 h. The changes in optical density, corresponding to enzyme activity, in samples stimulated for 1 h with ELEC was compared with that not exposed to ELEC. The obtained results show that the electrical current with the characteristics of the myoelectrical migrating complex (MMC) has an influence on pancreatic enzyme activity. Increased endopeptidase and reduced exopeptidase activity was noticed in samples treated with ELEC. This observation can be of important as analyzed factors which can alter enzymatic activity of the gut, can thus also affect feed/food digestibility. (c) 2007 Wiley-Liss, Inc.

  6. Measuring molecular biomarkers in epidemiologic studies: laboratory techniques and biospecimen considerations.

    PubMed

    Erickson, Heidi S

    2012-09-28

    The future of personalized medicine depends on the ability to efficiently and rapidly elucidate a reliable set of disease-specific molecular biomarkers. High-throughput molecular biomarker analysis methods have been developed to identify disease risk, diagnostic, prognostic, and therapeutic targets in human clinical samples. Currently, high throughput screening allows us to analyze thousands of markers from one sample or one marker from thousands of samples and will eventually allow us to analyze thousands of markers from thousands of samples. Unfortunately, the inherent nature of current high throughput methodologies, clinical specimens, and cost of analysis is often prohibitive for extensive high throughput biomarker analysis. This review summarizes the current state of high throughput biomarker screening of clinical specimens applicable to genetic epidemiology and longitudinal population-based studies with a focus on considerations related to biospecimens, laboratory techniques, and sample pooling. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Determination of Vanadium, Tin and Mercury in Atmospheric Particulate Matter and Cement Dust Samples by Direct Current Plasma Atomic Emission Spectrometry.

    ERIC Educational Resources Information Center

    Hindy, Kamal T.; And Others

    1992-01-01

    An atmospheric pollution study applies direct current plasma atomic emission spectrometry (DCP-AES) to samples of total suspended particulate matter collected in two industrial areas and one residential area, and cement dust collected near major cement factories. These samples were analyzed for vanadium, tin, and mercury. The results indicate the…

  8. Experimental study of atmospheric-pressure micro-plasmas for the ambient sampling of conductive materials

    NASA Astrophysics Data System (ADS)

    Duan, Zhengchao; He, Feng; Si, Xinlu; Bradley, James W.; Ouyang, Jiting

    2018-02-01

    Conductive solid material sampling by micro-plasma under ambient atmosphere was studied experimentally. A high-voltage pulse generator was utilized to drive discharge between a tungsten needle and metal samples. The effects of pulse width on discharge, micro-plasma and sampling were investigated. The electrical results show that two discharge current pulses can be formed in one voltage pulse. The duration of the first current pulse is of the order of 100 ns. The duration of the second current pulse depends on the width of the voltage pulse. The electrical results also show that arc micro-plasma was generated during both current pulses. The results of the emission spectra of different sampled materials indicate that the relative emission intensity of elemental metal ions will increase with pulse width. The excitation temperature and electron density of the arc micro-plasmas increase with the voltage pulse width, which contributes to the increase of relative emission intensity of metal ions. The optical images and energy dispersive spectroscopy results of the sampling spots on metal surfaces indicate that discharge with a short voltage pulse can generate a small sputtering crater.

  9. Numerical study of the process parameters in spark plasma sintering (sps)

    NASA Astrophysics Data System (ADS)

    Chowdhury, Redwan Jahid

    Spark plasma sintering (SPS) is one of the most widely used sintering techniques that utilizes pulsed direct current together with uniaxial pressure to consolidate a wide variety of materials. The unique mechanisms of SPS enable it to sinter powder compacts at a lower temperature and in a shorter time than the conventional hot pressing, hot isostatic pressing and vacuum sintering process. One of the limitations of SPS is the presence of temperature gradients inside the sample, which could result in non-uniform physical and microstructural properties. Detailed study of the temperature and current distributions inside the sintered sample is necessary to minimize the temperature gradients and achieve desired properties. In the present study, a coupled thermal-electric model was developed using finite element codes in ABAQUS software to investigate the temperature and current distributions inside the conductive and non-conductive samples. An integrated experimental-numerical methodology was implemented to determine the system contact resistances accurately. The developed sintering model was validated by a series of experiments, which showed good agreements with simulation results. The temperature distribution inside the sample depends on some process parameters such as sample and tool geometry, punch and die position, applied current and thermal insulation around the die. The role of these parameters on sample temperature distribution was systematically analyzed. The findings of this research could prove very useful for the reliable production of large size sintered samples with controlled and tailored properties.

  10. Phootprint - A Phobos sample return mission study

    NASA Astrophysics Data System (ADS)

    Koschny, Detlef; Svedhem, Håkan; Rebuffat, Denis

    Introduction ESA is currently studying a mission to return a sample from Phobos, called Phootprint. This study is performed as part of ESA’s Mars Robotic Exploration Programme. Part of the mission goal is to prepare technology needed for a sample return mission from Mars itself; the mission should also have a strong scientific justification, which is described here. 1. Science goal The main science goal of this mission will be to Understand the formation of the Martian moons Phobos and put constraints on the evolution of the solar system. Currently, there are several possibilities for explaining the formation of the Martian moons: (a) co-formation with Mars (b) capture of objects coming close to Mars (c) Impact of a large body onto Mars and formation from the impact ejecta The main science goal of this mission is to find out which of the three scenarios is the most probable one. To do this, samples from Phobos would be returned to Earth and analyzed with extremely high precision in ground-based laboratories. An on-board payload is foreseen to provide information to put the sample into the necessary geological context. 2. Mission Spacecraft and payload will be based on experience gained from previous studies to Martian moons and asteroids. In particular the Marco Polo and MarcoPolo-R asteroid sample return mission studies performed at ESA were used as a starting point. Currently, industrial studies are ongoing. The initial starting assumption was to use a Soyuz launcher. Uunlike the initial Marco Polo and MarcoPolo-R studies to an asteroid, a transfer stage will be needed. Another main difference to an asteroid mission is the fact that the spacecraft actually orbits Mars, not Phobos or Deimos. It is possible to select a spacecraft orbit, which in a Phobos- or Deimos-centred reference system would give an ellipse around the moon. The following model payload is currently foreseen: - Wide Angle Camera, - Narrow Angle Camera, - Close-Up Camera, - Context camera for sampling context, - visible-IR spectrometer - thermal IR spectrometer - and a Radio Science investigation. It is expected that with these instruments the necessary context for the sample can be provided. The paper will focus on the current status of the mission study.

  11. Analysis of critical thinking ability in direct current electrical problems solving

    NASA Astrophysics Data System (ADS)

    Hartono; Sunarno, Widha; Sarwanto; Arya Nugraha, Dewanta

    2017-11-01

    This study concern on analyzing the ability of students in critical thinking skills on the subject matter of direct current electricity. Samples were taken using purposive random sampling consisted of 32 students of grade XI, Multimedia 1, SMK Negeri 3 Surakarta in academic year 2016/2017. This study used descriptive quantitative method. The data were collected using tests and interviews regarding the subject matter of direct current electricity. Based on the results, students are getting some difficulties in solving problem in indicator 4. The average of students’ correct answer is 62.8%.

  12. Evaluation of Surface Sampling for Bacillus Spores Using ...

    EPA Pesticide Factsheets

    Journal Article In this study, commercially-available domestic cleaning robots were evaluated for spore surface sampling efficiency on common indoor surfaces. The current study determined the sampling efficiency of each robot, without modifying the sensors, algorithms, or logics set by the manufacturers.

  13. High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers

    USGS Publications Warehouse

    Chapin, Thomas

    2015-01-01

    Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during a deployment. However, these automated samplers are not well suited for long-term sampling in remote areas or in freezing conditions. There is a critical need for low-cost, long-duration, high-frequency water sampling technology to improve our understanding of the geochemical response to temporally variable processes. This review article will examine recent developments in automated water sampler technology and utilize selected field data from acid mine drainage studies to illustrate the utility of high-frequency, long-duration water sampling.

  14. Decoder calibration with ultra small current sample set for intracortical brain-machine interface

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Ma, Xuan; Chen, Luyao; Zhou, Jin; Wang, Changyong; Li, Wei; He, Jiping

    2018-04-01

    Objective. Intracortical brain-machine interfaces (iBMIs) aim to restore efficient communication and movement ability for paralyzed patients. However, frequent recalibration is required for consistency and reliability, and every recalibration will require relatively large most current sample set. The aim in this study is to develop an effective decoder calibration method that can achieve good performance while minimizing recalibration time. Approach. Two rhesus macaques implanted with intracortical microelectrode arrays were trained separately on movement and sensory paradigm. Neural signals were recorded to decode reaching positions or grasping postures. A novel principal component analysis-based domain adaptation (PDA) method was proposed to recalibrate the decoder with only ultra small current sample set by taking advantage of large historical data, and the decoding performance was compared with other three calibration methods for evaluation. Main results. The PDA method closed the gap between historical and current data effectively, and made it possible to take advantage of large historical data for decoder recalibration in current data decoding. Using only ultra small current sample set (five trials of each category), the decoder calibrated using the PDA method could achieve much better and more robust performance in all sessions than using other three calibration methods in both monkeys. Significance. (1) By this study, transfer learning theory was brought into iBMIs decoder calibration for the first time. (2) Different from most transfer learning studies, the target data in this study were ultra small sample set and were transferred to the source data. (3) By taking advantage of historical data, the PDA method was demonstrated to be effective in reducing recalibration time for both movement paradigm and sensory paradigm, indicating a viable generalization. By reducing the demand for large current training data, this new method may facilitate the application of intracortical brain-machine interfaces in clinical practice.

  15. Disentangling the relationship between child maltreatment and violent delinquency: using a nationally representative sample.

    PubMed

    Yun, Ilhong; Ball, Jeremy D; Lim, Hyeyoung

    2011-01-01

    This study uses the National Longitudinal Study of Adolescents (Add Health) data, a nationally representative sample of adolescents, to disentangle the relationship between child maltreatment and violent delinquency. Also examined are potential moderating effects of gender, socioeconomic status (SES), and religiosity on the association between child maltreatment and violent delinquency. Contrary to prior research findings, the current analyses reveal that physical abuse is not associated with future violent delinquency, whereas sexual abuse and neglect predict violent delinquency significantly. The current study also did not reveal any moderating effects of gender, SES, and religiosity on the association between maltreatment and violent delinquency. Interpretations of these findings are presented, drawing on the properties of the national probability sample compared to the findings of most prior studies that used localized samples.

  16. Prevalence of depression among mothers of young children in Honduras.

    PubMed

    Wulsin, Lawson; Somoza, Eugene; Heck, Jeffery; Bauer, Leah

    2010-01-01

    Maternal depression is a substantial problem that has negative consequences on the health of both mother and child. Little research has been done on the prevalence of maternal depression in the developing world. This study aims to estimate the prevalence of current depression among mothers in Honduras and identify demographic predictors of depression in this sample. A modified Spanish version of the PHQ-9 and a demographic questionnaire were administered by trained interviewers to 415 rural and urban women aged 15-66 who had children between 1 and 10 years old. Prevalence of current major depressive syndrome was 17.6%. Mild depressive symptoms were detected in 52% of the sample. The estimated prevalence of current major depressive syndrome in the urban sample (19%) was not significantly greater than in the rural sample (16%, p = 0.49). None of the demographic variables measured, including age, number of children, or marital status predicted major depression in this sample. Maternal depression occurred at a high rate in this sample of Honduran women. The estimated prevalence rates in this study are similar to rates of maternal depression in studies of mothers in other Latin American countries, as well as in samples of mothers on Medicaid in the United States. Further study is needed to confirm and extend these findings, and to identify predictors of maternal depression in this population.

  17. Mars Sample Return Architecture Assessment Study

    NASA Astrophysics Data System (ADS)

    Centuori, S.; Hermosín, P.; Martín, J.; De Zaiacomo, G.; Colin, S.; Godfrey, A.; Myles, J.; Johnson, H.; Sachdev, T.; Ahmed, R.

    2018-04-01

    Current paper presents the results of ESA funded activity "Mars Sample Return Architecture Assessment Study" carried-out by DEIMOS Space, Lockheed Martin UK Ampthill, and MDA Corporation, where more than 500 mission design options have been studied.

  18. Current Flow in the Bubble and Stripe Phases

    NASA Astrophysics Data System (ADS)

    Friess, B.; Umansky, V.; von Klitzing, K.; Smet, J. H.

    2018-03-01

    The spontaneous ordering of spins and charges in geometric patterns is currently under scrutiny in a number of different material systems. A topic of particular interest is the interaction of such ordered phases with itinerant electrons driven by an externally imposed current. It not only provides important information on the charge ordering itself but potentially also allows manipulating the shape and symmetry of the underlying pattern if current flow is strong enough. Unfortunately, conventional transport methods probing the macroscopic resistance suffer from the fact that the voltage drop along the sample edges provides only indirect information on the bulk properties because a complex current distribution is elicited by the inhomogeneous ground state. Here, we promote the use of surface acoustic waves to study these broken-symmetry phases and specifically address the bubble and stripe phases emerging in high-quality two-dimensional electron systems in GaAs /AlGaAs heterostructures as prototypical examples. When driving a unidirectional current, we find a surprising discrepancy between the sound propagation probing the bulk of the sample and the voltage drop along the sample edges. Our results prove that the current-induced modifications observed in resistive transport measurements are in fact a local phenomenon only, leaving the majority of the sample unaltered. More generally, our findings shed new light on the extent to which these ordered electron phases are impacted by an external current and underline the intrinsic advantages of acoustic measurements for the study of such inhomogeneous phases.

  19. The Effects of Finite Sampling on State Assessment Sample Requirements. NAEP Validity Studies. Working Paper Series.

    ERIC Educational Resources Information Center

    Chromy, James R.

    This study addressed statistical techniques that might ameliorate some of the sampling problems currently facing states with small populations participating in State National Assessment of Educational Progress (NAEP) assessments. The study explored how the application of finite population correction factors to the between-school component of…

  20. Photoinduced currents in pristine and ion irradiated kapton-H polyimide

    NASA Astrophysics Data System (ADS)

    Sharma, Anu; Sridharbabu, Y.; Quamara, J. K.

    2014-10-01

    The photoinduced currents in pristine and ion irradiated kapton-H polyimide have been investigated for different applied electric fields at 200°C. Particularly the effect of illumination intensity on the maximum current obtained as a result of photoinduced polarization has been studied. Samples were irradiated by using PELLETRON facility, IUAC, New Delhi. The photo-carrier charge generation depends directly on intensity of illumination. The samples irradiated at higher fluence show a decrease in the peak current with intensity of illumination. The secondary radiation induced crystallinity (SRIC) is responsible for the increase in maximum photoinduced currents generated with intensity of illumination.

  1. Photoinduced currents in pristine and ion irradiated kapton-H polyimide

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

    Sharma, Anu, E-mail: sharmaanu81@gmail.com; Sridharbabu, Y., E-mail: sharmaanu81@gmail.com; Quamara, J. K., E-mail: sharmaanu81@gmail.com

    2014-10-15

    The photoinduced currents in pristine and ion irradiated kapton-H polyimide have been investigated for different applied electric fields at 200°C. Particularly the effect of illumination intensity on the maximum current obtained as a result of photoinduced polarization has been studied. Samples were irradiated by using PELLETRON facility, IUAC, New Delhi. The photo-carrier charge generation depends directly on intensity of illumination. The samples irradiated at higher fluence show a decrease in the peak current with intensity of illumination. The secondary radiation induced crystallinity (SRIC) is responsible for the increase in maximum photoinduced currents generated with intensity of illumination.

  2. Scanning tunneling spectroscopy under large current flow through the sample.

    PubMed

    Maldonado, A; Guillamón, I; Suderow, H; Vieira, S

    2011-07-01

    We describe a method to make scanning tunneling microscopy/spectroscopy imaging at very low temperatures while driving a constant electric current up to some tens of mA through the sample. It gives a new local probe, which we term current driven scanning tunneling microscopy/spectroscopy. We show spectroscopic and topographic measurements under the application of a current in superconducting Al and NbSe(2) at 100 mK. Perspective of applications of this local imaging method includes local vortex motion experiments, and Doppler shift local density of states studies.

  3. Definition of intercultural competence (IC) in undergraduate students at a private university in the USA: A mixed-methods study.

    PubMed

    Gierke, Lioba; Binder, Nadine; Heckmann, Mark; Odağ, Özen; Leiser, Anne; Kedzior, Karina Karolina

    2018-01-01

    Intercultural competence (IC) is an important skill to be gained from higher education. However, it remains unclear what IC means to students and what factors might influence their definitions of IC. The aim of the current study was to qualitatively assess how students at one higher education institution in the USA define IC and to quantitatively test for relationships among IC components and various demographic characteristics, including intercultural experience and study context. A further aim was to descriptively compare the IC definitions from the US sample with the definitions obtained from another sample of university students in Germany. A purposive sample of n = 93 undergraduate, second semester students at Dickinson College, USA, participated in the study by completing an online questionnaire. The qualitative data were content-analyzed to define the dimensions of IC. The quantitative data were cluster-analyzed to assess the multivariate relationships among the IC components and the demographic characteristics of the sample. The most important dimensions of IC were Knowledge, External Outcomes (interaction, communication), and Attitudes (respect, tolerance) according to the US sample. The most frequently chosen dimensions of IC differed between both samples: Knowledge was chosen by the sample in the USA while External Outcomes was chosen by the sample in Germany. Relative to the US sample, significantly more students chose Attitudes, External Outcomes, and Intrapersonal Skills in the sample in Germany. The relationships among IC components and demographic characteristics were only weak in the US sample. A person with IC was rated as Open-minded and Respectful by students who lived predominantly in the USA or Tolerant and Curious by those who lived outside the USA for at least six months. The current results suggest that students residing in two countries (USA or Germany) define IC using similar dimensions. However, IC definitions may depend on the intercultural experience and the current global discourse. Longitudinal studies with representative samples are required to assess how IC definitions change over time.

  4. Characterization of YBa2Cu3O7, including critical current density Jc, by trapped magnetic field

    NASA Technical Reports Server (NTRS)

    Chen, In-Gann; Liu, Jianxiong; Weinstein, Roy; Lau, Kwong

    1992-01-01

    Spatial distributions of persistent magnetic field trapped by sintered and melt-textured ceramic-type high-temperature superconductor (HTS) samples have been studied. The trapped field can be reproduced by a model of the current consisting of two components: (1) a surface current Js and (2) a uniform volume current Jv. This Js + Jv model gives a satisfactory account of the spatial distribution of the magnetic field trapped by different types of HTS samples. The magnetic moment can be calculated, based on the Js + Jv model, and the result agrees well with that measured by standard vibrating sample magnetometer (VSM). As a consequence, Jc predicted by VSM methods agrees with Jc predicted from the Js + Jv model. The field mapping method described is also useful to reveal the granular structure of large HTS samples and regions of weak links.

  5. Evaluation of standardized sample collection, packaging, and decontamination procedures to assess cross-contamination potential during Bacillus anthracis incident response operations

    PubMed Central

    Calfee, M. Worth; Tufts, Jenia; Meyer, Kathryn; McConkey, Katrina; Mickelsen, Leroy; Rose, Laura; Dowell, Chad; Delaney, Lisa; Weber, Angela; Morse, Stephen; Chaitram, Jasmine; Gray, Marshall

    2016-01-01

    Sample collection procedures and primary receptacle (sample container and bag) decontamination methods should prevent contaminant transfer between contaminated and non-contaminated surfaces and areas during bio-incident operations. Cross-contamination of personnel, equipment, or sample containers may result in the exfiltration of biological agent from the exclusion (hot) zone and have unintended negative consequences on response resources, activities and outcomes. The current study was designed to: (1) evaluate currently recommended sample collection and packaging procedures to identify procedural steps that may increase the likelihood of spore exfiltration or contaminant transfer; (2) evaluate the efficacy of currently recommended primary receptacle decontamination procedures; and (3) evaluate the efficacy of outer packaging decontamination methods. Wet- and dry-deposited fluorescent tracer powder was used in contaminant transfer tests to qualitatively evaluate the currently-recommended sample collection procedures. Bacillus atrophaeus spores, a surrogate for Bacillus anthracis, were used to evaluate the efficacy of spray- and wipe-based decontamination procedures. Both decontamination procedures were quantitatively evaluated on three types of sample packaging materials (corrugated fiberboard, polystyrene foam, and polyethylene plastic), and two contamination mechanisms (wet or dry inoculums). Contaminant transfer results suggested that size-appropriate gloves should be worn by personnel, templates should not be taped to or removed from surfaces, and primary receptacles should be selected carefully. The decontamination tests indicated that wipe-based decontamination procedures may be more effective than spray-based procedures; efficacy was not influenced by material type but was affected by the inoculation method. Incomplete surface decontamination was observed in all tests with dry inoculums. This study provides a foundation for optimizing current B. anthracis response procedures to minimize contaminant exfiltration. PMID:27362274

  6. Evaluation of standardized sample collection, packaging, and decontamination procedures to assess cross-contamination potential during Bacillus anthracis incident response operations.

    PubMed

    Calfee, M Worth; Tufts, Jenia; Meyer, Kathryn; McConkey, Katrina; Mickelsen, Leroy; Rose, Laura; Dowell, Chad; Delaney, Lisa; Weber, Angela; Morse, Stephen; Chaitram, Jasmine; Gray, Marshall

    2016-12-01

    Sample collection procedures and primary receptacle (sample container and bag) decontamination methods should prevent contaminant transfer between contaminated and non-contaminated surfaces and areas during bio-incident operations. Cross-contamination of personnel, equipment, or sample containers may result in the exfiltration of biological agent from the exclusion (hot) zone and have unintended negative consequences on response resources, activities and outcomes. The current study was designed to: (1) evaluate currently recommended sample collection and packaging procedures to identify procedural steps that may increase the likelihood of spore exfiltration or contaminant transfer; (2) evaluate the efficacy of currently recommended primary receptacle decontamination procedures; and (3) evaluate the efficacy of outer packaging decontamination methods. Wet- and dry-deposited fluorescent tracer powder was used in contaminant transfer tests to qualitatively evaluate the currently-recommended sample collection procedures. Bacillus atrophaeus spores, a surrogate for Bacillus anthracis, were used to evaluate the efficacy of spray- and wipe-based decontamination procedures. Both decontamination procedures were quantitatively evaluated on three types of sample packaging materials (corrugated fiberboard, polystyrene foam, and polyethylene plastic), and two contamination mechanisms (wet or dry inoculums). Contaminant transfer results suggested that size-appropriate gloves should be worn by personnel, templates should not be taped to or removed from surfaces, and primary receptacles should be selected carefully. The decontamination tests indicated that wipe-based decontamination procedures may be more effective than spray-based procedures; efficacy was not influenced by material type but was affected by the inoculation method. Incomplete surface decontamination was observed in all tests with dry inoculums. This study provides a foundation for optimizing current B. anthracis response procedures to minimize contaminant exfiltration.

  7. Targeted or whole genome sequencing of formalin fixed tissue samples: potential applications in cancer genomics.

    PubMed

    Munchel, Sarah; Hoang, Yen; Zhao, Yue; Cottrell, Joseph; Klotzle, Brandy; Godwin, Andrew K; Koestler, Devin; Beyerlein, Peter; Fan, Jian-Bing; Bibikova, Marina; Chien, Jeremy

    2015-09-22

    Current genomic studies are limited by the poor availability of fresh-frozen tissue samples. Although formalin-fixed diagnostic samples are in abundance, they are seldom used in current genomic studies because of the concern of formalin-fixation artifacts. Better characterization of these artifacts will allow the use of archived clinical specimens in translational and clinical research studies. To provide a systematic analysis of formalin-fixation artifacts on Illumina sequencing, we generated 26 DNA sequencing data sets from 13 pairs of matched formalin-fixed paraffin-embedded (FFPE) and fresh-frozen (FF) tissue samples. The results indicate high rate of concordant calls between matched FF/FFPE pairs at reference and variant positions in three commonly used sequencing approaches (whole genome, whole exome, and targeted exon sequencing). Global mismatch rates and C · G > T · A substitutions were comparable between matched FF/FFPE samples, and discordant rates were low (<0.26%) in all samples. Finally, low-pass whole genome sequencing produces similar pattern of copy number alterations between FF/FFPE pairs. The results from our studies suggest the potential use of diagnostic FFPE samples for cancer genomic studies to characterize and catalog variations in cancer genomes.

  8. Evaluation, development, and characterization of superconducting materials for space applications

    NASA Technical Reports Server (NTRS)

    Thorpe, Arthur N.

    1990-01-01

    The anisotropic electromagnetic features of a grain-aligned YBa2Cu3O(x) bulk sample derived from a process of long-time partial melt growth were investigated by the measurements of direct current magnetization (at 77 K) and alternating current susceptibility as a function of temperature, with the fields applied parallel and perpendicular to the c axis, respectively. The extended Bean model was further studied and applied to explain the experimental results. Upon comparison of the grain-aligned sample with pure single crystal materials, it is concluded that because of the existence of more effective pinning sites in the grain-aligned sample, not only its critical current density perpendicular to the c axis is improved, but the one parallel to the c axis is improved even more significantly. The anisotropy in the critical current densities in the grain-aligned sample at 77 K is at least one to two orders of magnitude smaller than in the pure single crystal. The measurement of anisotropy of alternating current susceptibility as a function of temperature, especially its imaginary part, shows that there are still some residues of interlayer weak links in the grain-aligned samples, but they are quite different from and far less serious than the weak links in the sintered sample.

  9. Adults' Views on Mathematics Education: A Midwest Sample

    ERIC Educational Resources Information Center

    Brez, Caitlin C.; Allen, Jessica J.

    2016-01-01

    Currently, few studies have addressed public opinions regarding math education. The current study surveyed adults in a Midwestern town in the United States to assess opinions regarding math and math education. Overall, we found that adults believe that math is useful and that math education is important. We found that parents who currently have a…

  10. Who Are We Studying? Sample Diversity in Teaching of Psychology Research

    ERIC Educational Resources Information Center

    Richmond, Aaron S.; Broussard, Kristin A.; Sterns, Jillian L.; Sanders, Kristina K.; Shardy, Justin C.

    2015-01-01

    The purpose of the current study was to examine the sample diversity of empirical articles published in four premier teaching of psychology journals from 2008 to 2013. We investigated which demographic information was commonly reported and if samples were ethnically representative and whether gender was representative compared to National…

  11. CIDR

    Science.gov Websites

    studies. Investigators must supply positive and negative controls. Current pricing for CIDR Program studies are for a minimum study size of 90 samples and increasing in multiples of 90. Please inquire for for the assay is included for CIDR Program studies. FFPE samples are supported for MethylationEPIC

  12. A population-based study of associations between current posttraumatic stress symptoms and current fatigue.

    PubMed

    Lerdal, Anners; Lee, Kathryn A; Rokne, Berit; Knudsen, Øistein; Wahl, Astrid K; Dahl, Alv A

    2010-10-01

    This study explores current experience with posttraumatic stress disorder (PTSD) symptoms and other variables (sociodemographic, mental distress, somatic morbidity, self-rated health, and quality of life [QoL]) in relation to fatigue. A representative sample of the Norwegian population (N = 3,944) was invited to participate in a mailed survey, and 1,857 (47%) returned valid responses on the questionnaire that included the Fatigue Severity Scale and the Posttraumatic Symptom Scale-10. Posttraumatic stress disorder symptoms showed a strong association with fatigue in univariate (β = .41) and multivariate analyses (β = .33). Associations between psychosocial health variables, QoL, and fatigue were confirmed. However, PTSD symptoms showed the strongest association with fatigue in the analyses. Findings need to be replicated in other population samples and in clinical samples with PTSD and fatigue.

  13. The Effect of Neighborhood Racial Composition on the Relationship Between Minority Group Status and Current Fertility.

    ERIC Educational Resources Information Center

    Marcum, John P.

    Focusing on blacks, the study examined the effect of neighborhood racial composition on the relationship between socioeconomic status and current fertility. The sample of 611 black and 5,027 white once-married women aged 20-29 living with their husbands was drawn from the neighborhood characteristics files of the 1970 Public Use Samples of the…

  14. A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders

    PubMed Central

    Locci, Antonio Mario; Cincotti, Alberto; Todde, Sara; Orrù, Roberto; Cao, Giacomo

    2010-01-01

    A novel methodology is proposed for investigating the effect of the pulsed electric current during the spark plasma sintering (SPS) of electrically conductive powders without potential misinterpretation of experimental results. First, ensemble configurations (geometry, size and material of the powder sample, die, plunger and spacers) are identified where the electric current is forced to flow only through either the sample or the die, so that the sample is heated either through the Joule effect or by thermal conduction, respectively. These ensemble configurations are selected using a recently proposed mathematical model of an SPS apparatus, which, once suitably modified, makes it possible to carry out detailed electrical and thermal analysis. Next, SPS experiments are conducted using the ensemble configurations theoretically identified. Using aluminum powders as a case study, we find that the temporal profiles of sample shrinkage, which indicate densification behavior, as well as the final density of the sample are clearly different when the electric current flows only through the sample or through the die containing it, whereas the temperature cycle and mechanical load are the same in both cases. PMID:27877354

  15. A descriptive study of sexual homicide in Canada: implications for police investigation.

    PubMed

    Beauregard, Eric; Martineau, Melissa

    2013-12-01

    Few empirical studies have been conducted that examine the phenomenon of sexual homicide, and among these studies, many have been limited by small sample size. Although interesting and informative, these studies may not be representative of the greater phenomenon of sexual murder and may be subject to sampling bias that could have significant effects on results. The current study aims to provide a descriptive analysis of the largest sample of sexual homicide cases across Canada in the past 62 years. In doing so, the study aims to examine offender and victim characteristics, victim targeting and access, and modus operandi. Findings show that cases of sexual homicide and sexual murderers included in the current study differ in many aspects from the portrait of the sexual murderer and his or her crime depicted in previous studies. The authors' results may prove useful to the police officers responsible for the investigation of these crimes.

  16. Wave-current induced erosion of cohesive riverbanks in northern Manitoba, Canada

    NASA Astrophysics Data System (ADS)

    Kimiaghalam, N.; Clark, S.; Ahmari, H.; Hunt, J.

    2015-03-01

    The field of cohesive soil erosion is still not fully understood, in large part due to the many soil parameters that affect cohesive soil erodibility. This study is focused on two channels, 2-Mile and 8-Mile channels in northern Manitoba, Canada, that were built to connect Lake Winnipeg with Playgreen Lake and Playgreen Lake with Kiskikittogisu Lake, respectively. The banks of the channels consist of clay rich soils and alluvial deposits of layered clay, silts and sands. The study of erosion at the sites is further complicated because the flow-induced erosion is combined with the effects of significant wave action due to the large fetch length on the adjacent lakes, particularly Lake Winnipeg that is the seventh largest lake in North America. The study included three main components: field measurements, laboratory experiments and numerical modelling. Field measurements consisted of soil sampling from the banks and bed of the channels, current measurements and water sampling. Grab soil samples were used to measure the essential physical and electrochemical properties of the riverbanks, and standard ASTM Shelby tube samples were used to estimate the critical shear stress and erodibility of the soil samples using an erosion measurement device (EMD). Water samples were taken to estimate the sediment concentration profile and also to monitor changes in sediment concentration along the channels over time. An Acoustic Doppler Current Profiler (ADCP) was used to collect bathymetry and current data, and two water level gauges have been installed to record water levels at the entrance and outlet of the channels. The MIKE 21 NSW model was used to simulate waves using historical winds and measured bathymetry of the channels and lakes. Finally, results from the wave numerical model, laboratory tests and current measurement were used to estimate the effect of each component on erodibility of the cohesive banks.

  17. Analytical solution for the effect of the permittivity of coating layer on eddy current generated in an aluminum sample by EMAT

    NASA Astrophysics Data System (ADS)

    Sun, Feiran; Sun, Zhenguo; Chen, Qiang

    2016-02-01

    In order to improve the ultrasonic wave amplitude excited by electromagnetic acoustic transducers (EMATs), many researchers have proposed models. But they always ignored displacement current or the effect of the permittivity of the air or the metal sample during modeling, due to its low permittivity. However, more durable dielectric materials are replacing or coating with metals in many applications which have a much higher permittivity than air or metal sample so that the effect of permittivity cannot be ignored. Based on an analytical model, the effect of the permittivity of coating layer on the eddy current generated in an aluminum sample by EMAT has been studied. The analytical analysis indicates that the eddy current density excited by the spiral coil of EMAT slowly increases in the beginning and then decreases rapidly while the permittivity increases, and it has much relation to the thickness of the coating layer and the exciting frequency, which is verified by the simulation result.

  18. Definition of intercultural competence (IC) in undergraduate students at a private university in the USA: A mixed-methods study

    PubMed Central

    Gierke, Lioba; Binder, Nadine; Heckmann, Mark; Odağ, Özen; Leiser, Anne

    2018-01-01

    Introduction Intercultural competence (IC) is an important skill to be gained from higher education. However, it remains unclear what IC means to students and what factors might influence their definitions of IC. The aim of the current study was to qualitatively assess how students at one higher education institution in the USA define IC and to quantitatively test for relationships among IC components and various demographic characteristics, including intercultural experience and study context. A further aim was to descriptively compare the IC definitions from the US sample with the definitions obtained from another sample of university students in Germany. Materials and methods A purposive sample of n = 93 undergraduate, second semester students at Dickinson College, USA, participated in the study by completing an online questionnaire. The qualitative data were content-analyzed to define the dimensions of IC. The quantitative data were cluster-analyzed to assess the multivariate relationships among the IC components and the demographic characteristics of the sample. Results The most important dimensions of IC were Knowledge, External Outcomes (interaction, communication), and Attitudes (respect, tolerance) according to the US sample. The most frequently chosen dimensions of IC differed between both samples: Knowledge was chosen by the sample in the USA while External Outcomes was chosen by the sample in Germany. Relative to the US sample, significantly more students chose Attitudes, External Outcomes, and Intrapersonal Skills in the sample in Germany. The relationships among IC components and demographic characteristics were only weak in the US sample. A person with IC was rated as Open-minded and Respectful by students who lived predominantly in the USA or Tolerant and Curious by those who lived outside the USA for at least six months. Discussion The current results suggest that students residing in two countries (USA or Germany) define IC using similar dimensions. However, IC definitions may depend on the intercultural experience and the current global discourse. Longitudinal studies with representative samples are required to assess how IC definitions change over time. PMID:29698525

  19. Synthesis of thoria nano-particles at low temperature through base electrogeneration on steel 316L surface: Effect of current density

    NASA Astrophysics Data System (ADS)

    Yousefi, Taher; Torab-Mostaedi, Meisam; Mobtaker, Hossein Ghasemi; Keshtkar, Ali Reza

    2016-10-01

    The strategy developed in this study, offers significant advantages (simplicity and cleanness of method and also a product purity and new morphology of the product) over the conventional routes for the synthesis of ThO2 nanostructure. The effect of current density on morphology was studied. The synthesized powder was characterized by means of Powder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM, Phillips EM 2085) Brunauer-Emmett-Teller (BET) and Fourier Transform Infrared (FT-IR) spectroscopy. The results show that the current density has a great effect on the morphology of the samples. The average size of the particles decreases as the applied current density increases and the average size of the samples decreases from 50 to 15 nm when the current density increases from 2 to 5 mA cm-2.

  20. Photometric and Colorimetric Assessment of LED Chip Scale Packages by Using a Step-Stress Accelerated Degradation Test (SSADT) Method.

    PubMed

    Qian, Cheng; Fan, Jiajie; Fang, Jiayi; Yu, Chaohua; Ren, Yi; Fan, Xuejun; Zhang, Guoqi

    2017-10-16

    By solving the problem of very long test time on reliability qualification for Light-emitting Diode (LED) products, the accelerated degradation test with a thermal overstress at a proper range is regarded as a promising and effective approach. For a comprehensive survey of the application of step-stress accelerated degradation test (SSADT) in LEDs, the thermal, photometric, and colorimetric properties of two types of LED chip scale packages (CSPs), i.e., 4000 °K and 5000 °K samples each of which was driven by two different levels of currents (i.e., 120 mA and 350 mA, respectively), were investigated under an increasing temperature from 55 °C to 150 °C and a systemic study of driving current effect on the SSADT results were also reported in this paper. During SSADT, junction temperatures of the test samples have a positive relationship with their driving currents. However, the temperature-voltage curve, which represents the thermal resistance property of the test samples, does not show significant variance as long as the driving current is no more than the sample's rated current. But when the test sample is tested under an overdrive current, its temperature-voltage curve is observed as obviously shifted to the left when compared to that before SSADT. Similar overdrive current affected the degradation scenario is also found in the attenuation of Spectral Power Distributions (SPDs) of the test samples. As used in the reliability qualification, SSADT provides explicit scenes on color shift and correlated color temperature (CCT) depreciation of the test samples, but not on lumen maintenance depreciation. It is also proved that the varying rates of the color shift and CCT depreciation failures can be effectively accelerated with an increase of the driving current, for instance, from 120 mA to 350 mA. For these reasons, SSADT is considered as a suitable accelerated test method for qualifying these two failure modes of LED CSPs.

  1. Variation in RGS2 is associated with suicidal ideation in an epidemiological study of adults exposed to the 2004 Florida hurricanes.

    PubMed

    Amstadter, Ananda B; Koenen, Karestan C; Ruggiero, Kenneth J; Acierno, Ron; Galea, Sandro; Kilpatrick, Dean G; Gelernter, Joel

    2009-01-01

    This study examined whether rs4606, a single nucleotide polymorphism (SNP) in the translated region at the 3' end of RGS2, was related to suicidal ideation in an epidemiologic sample of adults living in areas affected by the 2004 Florida hurricanes. An epidemiologic sample of residents of Florida was recruited via random digit-dial procedures after the 2004 Florida hurricanes; participants were interviewed about suicidal ideation, hurricane exposure, and social support. Participants who returned buccal DNA samples via mail (n = 607) were included here. Rs4606 in RGS2 was associated with increased symptoms of current suicidal ideation (p < 0.01). Each "C" allele was associated with 5.59 times increased risk of having current ideation. No gene-by-environment interactions were found, perhaps due to low power. RGS2 rs4606 is related to risk of current suicidal ideation in stressor-exposed adults.

  2. New approaches to wipe sampling methods for antineoplastic and other hazardous drugs in healthcare settings.

    PubMed

    Connor, Thomas H; Smith, Jerome P

    2016-09-01

    At the present time, the method of choice to determine surface contamination of the workplace with antineoplastic and other hazardous drugs is surface wipe sampling and subsequent sample analysis with a variety of analytical techniques. The purpose of this article is to review current methodology for determining the level of surface contamination with hazardous drugs in healthcare settings and to discuss recent advances in this area. In addition it will provide some guidance for conducting surface wipe sampling and sample analysis for these drugs in healthcare settings. Published studies on the use of wipe sampling to measure hazardous drugs on surfaces in healthcare settings drugs were reviewed. These studies include the use of well-documented chromatographic techniques for sample analysis in addition to newly evolving technology that provides rapid analysis of specific antineoplastic. Methodology for the analysis of surface wipe samples for hazardous drugs are reviewed, including the purposes, technical factors, sampling strategy, materials required, and limitations. The use of lateral flow immunoassay (LFIA) and fluorescence covalent microbead immunosorbent assay (FCMIA) for surface wipe sample evaluation is also discussed. Current recommendations are that all healthc a re settings where antineoplastic and other hazardous drugs are handled include surface wipe sampling as part of a comprehensive hazardous drug-safe handling program. Surface wipe sampling may be used as a method to characterize potential occupational dermal exposure risk and to evaluate the effectiveness of implemented controls and the overall safety program. New technology, although currently limited in scope, may make wipe sampling for hazardous drugs more routine, less costly, and provide a shorter response time than classical analytical techniques now in use.

  3. Neurocognitive Features of Attention Deficit Hyperactivity Disorder in a Non-Clinical Adult Sample

    DTIC Science & Technology

    2004-01-01

    samples. Whether these cognitive weaknesses are associated with ADHD symptoms in non-clinical samples is unknown. The current study examined the...relationship between ADHD symptoms and cognitive performance in a non-clinical adult sample of 75 men and women (ages 20 to 49). Self-report measures of ADHD

  4. Non-Equilibrium Superconductivity and Magnetic Pair Breaking in Perovskite Half-Metallic Ferromagnet-Insulator-Superconductor (F-I-S) Heterostructures

    NASA Technical Reports Server (NTRS)

    Fu, C.-C.; Yeh, N.-C.; Samoilov, A. V.; Vakili, K.; Li, Y.; Vasquez, R. P.

    1999-01-01

    The effect of spin-polarized quasiparticle currents on the critical current density (J-c) of cuprate superconductors is studied in perovskite F-I-S heterostructures as a function of insulator thickness and of underlying magnetic materials. A pulsed current technique is employed to minimize extraneous Joule heating on the superconductor. At temperatures near T-c, F-I-S samples with insulator thicknesses\\1e2nm show precipitous decrease in J_c as current injection (I_m) is increased. In contrast, J_c in a controlled sample with a substituted non-magnetic material (N-I-S) exhibit no dependence on I_m. Similarly, a F-I-S sample with a 10 mn insulating barrier also show little J_c effect versus I_m. At low temperatures with I_m = 0, significant suppression of J-c is observed only in the thin barrier F-I-S samples, although T_c and the normal-state resistivity of all samples are comparable. These phenomena can be attributed to the Cooper pair breaking induced by externally-injected and internally-reflected spin-polarized quasiparticle currents. We estimate an order of magnitude range for the spin diffusion length of 100 nm to 100\\ mum.

  5. Pesticides in Water and Suspended Sediment of the Alamo and New Rivers, Imperial Valley/Salton Sea Basin, California, 2006-2007

    USGS Publications Warehouse

    Orlando, James L.; Smalling, Kelly L.; Kuivila, Kathryn

    2008-01-01

    Water and suspended-sediment samples were collected at eight sites on the Alamo and New Rivers in the Imperial Valley/Salton Sea Basin of California and analyzed for both current-use and organochlorine pesticides by the U.S. Geological Survey. Samples were collected in the fall of 2006 and spring of 2007, corresponding to the seasons of greatest pesticide use in the basin. Large-volume water samples (up to 650 liters) were collected at each site and processed using a flow-through centrifuge to isolate suspended sediments. One-liter water samples were collected from the effluent of the centrifuge for the analysis of dissolved pesticides. Additional samples were collected for analysis of dissolved organic carbon and for suspended-sediment concentrations. Water samples were analyzed for a suite of 61 current-use and organochlorine pesticides using gas chromatography/mass spectrometry. A total of 25 pesticides were detected in the water samples, with seven pesticides detected in more than half of the samples. Dissolved concentrations of pesticides observed in this study ranged from below their respective method detection limits to 8,940 nanograms per liter (EPTC). The most frequently detected compounds in the water samples were chlorpyrifos, DCPA, EPTC, and trifluralin, which were observed in more than 75 percent of the samples. The maximum concentrations of most pesticides were detected in samples from the Alamo River. Maximum dissolved concentrations of carbofuran, chlorpyrifos, diazinon, and malathion exceeded aquatic life benchmarks established by the U.S. Environmental Protection Agency for these pesticides. Suspended sediments were analyzed for 87 current-use and organochlorine pesticides using microwave-assisted extraction, gel permeation chromatography for sulfur removal, and either carbon/alumina stacked solid-phase extraction cartridges or deactivated Florisil for removal of matrix interferences. Twenty current-use pesticides were detected in the suspended-sediment samples, including pyrethroid insecticides and fungicides. Fourteen legacy organochlorine pesticides also were detected in the suspended-sediment samples. Greater numbers of current-use and organochlorine pesticides were observed in the Alamo River samples in comparison with the New River samples. Maximum concentrations of current-use pesticides in suspended-sediment samples ranged from below their method detection limits to 174 micrograms per kilogram (pendimethalin). Most organochlorine pesticides were detected at or below their method detection limits, with the exception of p,p'-DDE, which had a maximum concentration of 54.2 micrograms per kilogram. The most frequently detected current-use pesticides in the suspended-sediment samples were chlorpyrifos, permethrin, tetraconazole, and trifluralin, which were observed in more than 83 percent of the samples. The organochlorine degradates p,p'-DDD and p,p'-DDE were detected in all suspended-sediment samples.

  6. Risky business: a longitudinal study examining cigarette smoking initiation among susceptible and non-susceptible e-cigarette users in Canada

    PubMed Central

    Aleyan, Sarah; Cole, Adam; Qian, Wei; Leatherdale, Scott T

    2018-01-01

    Objectives Given that many adolescent e-cigarette users are never-smokers, the possibility that e-cigarettes may act as a gateway to future cigarette smoking has been discussed in various studies. Longitudinal data are needed to explore the pathway between e-cigarette and cigarette use, particularly among different risk groups including susceptible and non-susceptible never-smokers. The objective of this study was to examine whether baseline use of e-cigarettes among a sample of never-smoking youth predicted cigarette smoking initiation over a 2-year period. Design Longitudinal cohort study. Setting 89 high schools across Ontario and Alberta, Canada. Participants A sample of grade 9–11 never-smoking students at baseline (n=9501) who participated in the COMPASS study over 2 years. Primary and secondary outcome measures Participants completed in-class questionnaires that assessed smoking susceptibility and smoking initiation. Results Among the baseline sample of non-susceptible never-smokers, 45.2% of current e-cigarette users reported trying a cigarette after 2 years compared with 13.5% of non-current e-cigarette users. Among the baseline sample of susceptible never-smokers, 62.4% of current e-cigarette users reported trying a cigarette after 2 years compared with 36.1% of non-current e-cigarette users. Overall, current e-cigarette users were more likely to try a cigarette 2 years later. This association was stronger among the sample of non-susceptible never-smokers (AOR=5.28, 95% CI 2.81 to 9.94; p<0.0001) compared with susceptible never-smokers (AOR=2.78, 95% CI 1.84 to 4.20; p<0.0001). Conclusions Findings from this large, longitudinal study support public health concerns that e-cigarette use may contribute to the development of a new population of cigarette smokers. They also support the notion that e-cigarettes are expanding the tobacco market by attracting low-risk youth who would otherwise be unlikely to initiate using cigarettes. Careful consideration will be needed in developing an appropriate regulatory framework that prevents e-cigarette use among youth. PMID:29804064

  7. Faculty Perceptions of Their Graduate Education

    ERIC Educational Resources Information Center

    Hermanowicz, Joseph C.

    2016-01-01

    Most studies of graduate school socialization utilize samples of either current students or recent graduates. This study investigates how professors, established in their academic careers, retrospectively view their graduate training by asking and examining what deficiencies they detect from this preparatory stage. The sample is composed of…

  8. Bioelectrical Impedance and The Frequency Dependent Current Conduction Through Biological Tissues: A Short Review

    NASA Astrophysics Data System (ADS)

    Kanti Bera, Tushar

    2018-03-01

    Biological tissues are developed with biological cells which exhibit complex electrical impedance called electrical bioimpedance. Under an alternating electrical excitation the bioimpedance varies with the tissue anatomy, composition and the signal frequency. The current penetration and conduction paths vary with frequency of the applied signal. Bioimpedance spectroscopy is used to study the frequency response of the electrical impedance of biological materials noninvasively. In bioimpedance spectroscopy, a low amplitude electrical signal is injected to the tissue sample or body parts to characterization the sample in terms of its bioimpedance. The electrical current conduction phenomena, which is highly influenced by the tissue impedance and the signal frequency, is an important phenomena which should be studied to understand the bioimpedance techniques like bioelectrical impedance analysis (BIA), EIS, or else. In this paper the origin of bioelectrical impedance and current conduction phenomena has been reviewed to present a brief summary of bioelectrical impedance and the frequency dependent current conduction through biological tissues. Simulation studies are conducted with alternation current injection through a two dimensional model of biological tissues containing finite number of biological cells suspended in extracellular fluid. The paper demonstrates the simulation of alternating current conduction through biological tissues conducted by COMSOL Multiphysics. Simulation studies also show the frequency response of the tissue impedance for different tissue compositions.

  9. Prevalence of cognitive impairment in major depression and bipolar disorder.

    PubMed

    Douglas, Katie M; Gallagher, Peter; Robinson, Lucy J; Carter, Janet D; McIntosh, Virginia Vw; Frampton, Christopher Ma; Watson, Stuart; Young, Allan H; Ferrier, I Nicol; Porter, Richard J

    2018-05-01

    The current study examines prevalence of cognitive impairment in four mood disorder samples, using four definitions of impairment. The impact of premorbid IQ on prevalence was examined, and the influence of treatment response. Samples were: (i) 58 inpatients in a current severe depressive episode (unipolar or bipolar), (ii) 69 unmedicated outpatients in a mild to moderate depressive episode (unipolar or bipolar), (iii) 56 outpatients with bipolar disorder, in a depressive episode, and (iv) 63 outpatients with bipolar disorder, currently euthymic. Cognitive assessment was conducted after treatment in Studies 1 (6 weeks of antidepressant treatment commenced on admission) and 2 (16-week course of cognitive behaviour therapy or schema therapy), allowing the impact of treatment response to be assessed. All mood disorder samples were compared with healthy control groups. The prevalence of cognitive impairment was highest for the inpatient depression sample (Study 1), and lowest for the outpatient depression sample (Study 2). Substantial variability in rates was observed depending on the definition of impairment used. Correcting cognitive performance for premorbid IQ had a significant impact on the prevalence of cognitive impairment in the inpatient depression sample. There was minimal evidence that treatment response impacted on prevalence of cognitive impairment, except in the domain of psychomotor speed in inpatients. As interventions aiming to improve cognitive outcomes in mood disorders receive increasing research focus, the issue of setting a cut-off level of cognitive impairment for screening purposes becomes a priority. This analysis demonstrates important differences in samples likely to be recruited depending on the definition of cognitive impairment and begins to examine the importance of premorbid IQ in determining who is impaired. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Variability of indoor fungal microbiome of green and non-green low-income homes in Cincinnati, Ohio.

    PubMed

    Coombs, Kanistha; Taft, Diana; Ward, Doyle V; Green, Brett J; Chew, Ginger L; Shamsaei, Behrouz; Meller, Jaroslaw; Indugula, Reshmi; Reponen, Tiina

    2018-01-01

    "Green" housing is designed to use low-impact materials, increase energy efficiency and improve occupant health. However, little is known about the indoor mycobiome of green homes. The current study is a subset of a multicenter study that aims to investigate the indoor environment of green homes and the respiratory health of asthmatic children. In the current study, the mycobiome in air, bed dust and floor dust was compared between green (study site) and non-green (control site), low-income homes in Cincinnati, Ohio. The samples were collected at baseline (within four months following renovation), and 12months after the baseline at the study site. Parallel sample collection was conducted in non-green control homes. Air samples were collected by PM2.5 samplers over 5-days. Bed and floor dust samples were vacuumed after the air sampling was completed. The DNA sample extracts were analyzed using ITS amplicon sequencing. Analysis indicated that there was no clear trend in the fungal communities between green and non-green homes. Instead, fungal community differences were greatest between sample types - air, bed, and floor. Microbial communities also changed substantially between sampling intervals in both green and non-green homes for all sample types, potentially indicating that there was very little stability in the mycobiomes. Research gaps remain regarding how indoor mycobiome fluctuates over time. Longer follow-up periods might elucidate the effect of green renovation on microbial load in buildings. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. What do you measure when you measure the Hall effect?

    NASA Astrophysics Data System (ADS)

    Koon, D. W.; Knickerbocker, C. J.

    1993-02-01

    A formalism for calculating the sensitivity of Hall measurements to local inhomogeneities of the sample material or the magnetic field is developed. This Hall weighting function g(x,y) is calculated for various placements of current and voltage probes on square and circular laminar samples. Unlike the resistivity weighting function, it is nonnegative throughout the entire sample, provided all probes lie at the edge of the sample. Singularities arise in the Hall weighting function near the current and voltage probes except in the case where these probes are located at the corners of a square. Implications of the results for cross, clover, and bridge samples, and the implications of our results for metal-insulator transition and quantum Hall studies are discussed.

  12. Can the use of pulsed direct current induce oscillation in the applied pressure during spark plasma sintering?

    PubMed Central

    Salamon, David; Eriksson, Mirva; Nygren, Mats; Shen, Zhijian

    2012-01-01

    The spark plasma sintering (SPS) process is known for its rapid densification of metals and ceramics. The mechanism behind this rapid densification has been discussed during the last few decades and is yet uncertain. During our SPS experiments we noticed oscillations in the applied pressure, related to a change in electric current. In this study, we investigated the effect of pulsed electrical current on the applied mechanical pressure and related changes in temperature. We eliminated the effect of sample shrinkage in the SPS setup and used a transparent quartz die allowing direct observation of the sample. We found that the use of pulsed direct electric current in our apparatus induces pressure oscillations with the amplitude depending on the current density. While sintering Ti samples we observed temperature oscillations resulting from pressure oscillations, which we attribute to magnetic forces generated within the SPS apparatus. The described current–pressure–temperature relations might increase understanding of the SPS process. PMID:27877472

  13. dbMDEGA: a database for meta-analysis of differentially expressed genes in autism spectrum disorder.

    PubMed

    Zhang, Shuyun; Deng, Libin; Jia, Qiyue; Huang, Shaoting; Gu, Junwang; Zhou, Fankun; Gao, Meng; Sun, Xinyi; Feng, Chang; Fan, Guangqin

    2017-11-16

    Autism spectrum disorders (ASD) are hereditary, heterogeneous and biologically complex neurodevelopmental disorders. Individual studies on gene expression in ASD cannot provide clear consensus conclusions. Therefore, a systematic review to synthesize the current findings from brain tissues and a search tool to share the meta-analysis results are urgently needed. Here, we conducted a meta-analysis of brain gene expression profiles in the current reported human ASD expression datasets (with 84 frozen male cortex samples, 17 female cortex samples, 32 cerebellum samples and 4 formalin fixed samples) and knock-out mouse ASD model expression datasets (with 80 collective brain samples). Then, we applied R language software and developed an interactive shared and updated database (dbMDEGA) displaying the results of meta-analysis of data from ASD studies regarding differentially expressed genes (DEGs) in the brain. This database, dbMDEGA ( https://dbmdega.shinyapps.io/dbMDEGA/ ), is a publicly available web-portal for manual annotation and visualization of DEGs in the brain from data from ASD studies. This database uniquely presents meta-analysis values and homologous forest plots of DEGs in brain tissues. Gene entries are annotated with meta-values, statistical values and forest plots of DEGs in brain samples. This database aims to provide searchable meta-analysis results based on the current reported brain gene expression datasets of ASD to help detect candidate genes underlying this disorder. This new analytical tool may provide valuable assistance in the discovery of DEGs and the elucidation of the molecular pathogenicity of ASD. This database model may be replicated to study other disorders.

  14. Forensic Tools to Track and Connect Physical Samples to Related Data

    NASA Astrophysics Data System (ADS)

    Molineux, A.; Thompson, A. C.; Baumgardner, R. W.

    2016-12-01

    Identifiers, such as local sample numbers, are critical to successfully connecting physical samples and related data. However, identifiers must be globally unique. The International Geo Sample Number (IGSN) generated when registering the sample in the System for Earth Sample Registration (SESAR) provides a globally unique alphanumeric code associated with basic metadata, related samples and their current physical storage location. When registered samples are published, users can link the figured samples to the basic metadata held at SESAR. The use cases we discuss include plant specimens from a Permian core, Holocene corals and derived powders, and thin sections with SEM stubs. Much of this material is now published. The plant taxonomic study from the core is a digital pdf and samples can be directly linked from the captions to the SESAR record. The study of stable isotopes from the corals is not yet digitally available, but individual samples are accessible. Full data and media records for both studies are located in our database where higher quality images, field notes, and section diagrams may exist. Georeferences permit mapping in current and deep time plate configurations. Several aspects emerged during this study. The first, ensure adequate and consistent details are registered with SESAR. Second, educate and encourage the researcher to obtain IGSNs. Third, publish the archive numbers, assigned prior to publication, alongside the IGSN. This provides access to further data through an Integrated Publishing Toolkit (IPT)/aggregators/or online repository databases, thus placing the initial sample in a much richer context for future studies. Fourth, encourage software developers to customize community software to extract data from a database and use it to register samples in bulk. This would improve workflow and provide a path for registration of large legacy collections.

  15. Smoking among troops deployed in combat areas and its association with combat exposure among navy personnel in Sri Lanka

    PubMed Central

    2012-01-01

    Background Among military personnel alcohol consumption and binge-drinking have increased but cigarette smoking has declined in the recent past. Although there is a strong association between smoking and PTSD the association between combat exposure and smoking is not clear. Methods This cross sectional study was carried out among representative samples of SLN Special Forces and regular forces deployed in combat areas. Both Special Forces and regular forces were selected using simple random sampling. Only personnel who had served continuously in combat areas during the one year period prior to end of combat operations were included in the study. Females were not included in the sample. The study assessed several mental health outcomes as well as alcohol use, smoking and cannabis use. Sample was classified according to smoking habits as never smokers, past smokers (those who had smoked in the past but not within the past year) and current smokers (those smoking at least one cigarette within the past 12 months). Results Sample consisted of 259 Special Forces and 412 regular navy personnel. Prevalence of current smoking was 17.9% (95% CI 14.9-20.8). Of the sample 58.4% had never smoked and 23.7% were past smokers. Prevalence of current smoking was significantly higher among Special Forces personnel compared to regular forces. (OR 1.90 (95% CI 1.20-3.02). Personnel aged ≥35 years had the lowest prevalence of smoking (14.0%). Commissioned officers had a lower prevalence (12.1%) than non commissioned officers or other ranks. After adjustment for demographic variables and service type there was significant association between smoking and combat experiences of seeing dead or wounded [OR 1.79 (95%CI 1.08-2.9)], handling dead bodies [OR 2.47(95%CI 1.6-3.81)], coming under small arms fire [OR 2.01(95%CI 1.28-3.15)] and coming under mortar, missile and artillery fire [OR 2.02(95%CI 1.29-3.17)]. There was significant association between the number of risk events and current smoking [OR 1.22 (95%CI1.11-1.35)]. Conclusions There was significant association between current smoking and combat experiences. Current smoking was strongly associated with current alcohol use. Prevalence of current smoking was less among military personnel than in the general population. Prevalence of smoking was significantly higher among Special Forces personnel. PMID:22776004

  16. On the Representativeness of Behavior Observation Samples in Classrooms

    ERIC Educational Resources Information Center

    Tiger, Jeffrey H.; Miller, Sarah J.; Mevers, Joanna Lomas; Mintz, Joslyn Cynkus; Scheithauer, Mindy C.; Alvarez, Jessica

    2013-01-01

    School consultants who rely on direct observation typically conduct observational samples (e.g., 1 30-min observation per day) with the hopes that the sample is representative of performance during the remainder of the day, but the representativeness of these samples is unclear. In the current study, we recorded the problem behavior of 3 referred…

  17. Effect of substrate thinning on the electronic transport characteristics of AlGaN/GaN HEMTs

    NASA Astrophysics Data System (ADS)

    Zhu, Hui; Meng, Xiao; Zheng, Xiang; Yang, Ying; Feng, Shiwei; Zhang, Yamin; Guo, Chunsheng

    2018-07-01

    We studied how substrate thinning affected the electronic transport characteristics of AlGaN/GaN HEMTs. By thinning their sapphire substrate from 460 μm to 80 μm, we varied the residual stress in these HEMTs. The thinned sample showed decreased drain-source current and occurrence of kink effect. Furthermore, shown by current transient measurements and time constant analysis, the detrapping behaviors of trap states shifted toward a larger time constant, and the detrapping behavior under the gate and in the gate-drain access region showed increased amplitude. By using pulsed current-voltage measurements, the thinned sample showed a positive shift of the threshold voltage, a decrease in peak transconductance, and an aggravation in current collapse, as compared with the thick one. The degradation of electrical behavior were associated with the structural degradation, as confirmed by the increase of pit density on the thinned sample surface.

  18. State Estimates of Disability in America. Disability Statistics Report 3.

    ERIC Educational Resources Information Center

    LaPlante, Mitchell P.

    This study presents and discusses existing data on disability by state, from the 1980 and 1990 censuses, the Current Population Survey (CPS), and the National Health Interview Survey (NHIS). The study used direct methods for states with large sample sizes and synthetic estimates for states with low sample sizes. The study's highlighted findings…

  19. Microgravity ignition experiment

    NASA Technical Reports Server (NTRS)

    Motevalli, Vahid; Elliott, William; Garrant, Keith; Marcotte, Ryan

    1992-01-01

    The purpose of this project is to develop a flight-ready apparatus of the microgravity ignition experiment for the GASCAN 2 program. The microgravity ignition experiment is designed to study how a microgravity environment affects the time to ignition of a sample of alpha-cellulose paper. A microgravity environment will result in a decrease in the heat transferred from the sample due to a lack of convection currents, which would decrease time to ignition. A lack of convection current would also cause the oxygen supply at the sample not to be renewed, which could delay or even prevent ignition. When this experiment is conducted aboard GASCAN 2, the dominant result of the lack of ignition will be determined. The experiment consists of four canisters containing four thermocouples and a sensor to detect ignition of the paper sample. This year the interior of the canister was redesigned and a mathematical model of the heat transfer around the sample was developed. This heat transfer model predicts an ignition time of approximately 5.5 seconds if the decrease of heat loss from the sample is the dominant factor of the lack of convection currents.

  20. Biomarker-Based Prediction Models for Response to Treatment in Systemic Sclerosis-Related Interstitial Lung Disease

    DTIC Science & Technology

    2017-10-01

    in the baseline samples of the Scleroderma Lung Study II (SLS II). We are currently analyzing whether these serum proteins have predictive...In this project, we use the valuable samples collected in the Scleroderma Lung Study II (SLSII) clinical trial and the observational cohort, GENISOS...determine key serum protein levels and transcript signatures in whole blood and skin samples collected in the SLSII study . The identified candidate

  1. Improved Sampling Method Reduces Isokinetic Sampling Errors.

    ERIC Educational Resources Information Center

    Karels, Gale G.

    The particulate sampling system currently in use by the Bay Area Air Pollution Control District, San Francisco, California is described in this presentation for the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. The method represents a practical, inexpensive tool that can…

  2. Women, Men and the Doctorate.

    ERIC Educational Resources Information Center

    Centra, John A; Kuykendall, Nancy M.

    This study describes the current status and professional development of a sample of women doctorates and compares them to a sample of men who have attained the same educational status. Chapters cover the sample and procedures used; employment patterns; doctorates in academe; publications, income, and job satisfaction; marriage and family life;…

  3. Methodological Choices in Rating Speech Samples

    ERIC Educational Resources Information Center

    O'Brien, Mary Grantham

    2016-01-01

    Much pronunciation research critically relies upon listeners' judgments of speech samples, but researchers have rarely examined the impact of methodological choices. In the current study, 30 German native listeners and 42 German L2 learners (L1 English) rated speech samples produced by English-German L2 learners along three continua: accentedness,…

  4. Fast temporal fluctuations in single-molecule junctions.

    PubMed

    Ochs, Roif; Secker, Daniel; Elbing, Mark; Mayor, Marcel; Weber, Heiko B

    2006-01-01

    The noise within the electrical current through single-molecule junctions is studied cryogenic temperature. The organic sample molecules were contacted with the mechanically controlled break-junction technique. The noise spectra refer to a where only few Lorentzian fluctuators occur in the conductance. The frequency dependence shows qualitative variations from sample to sample.

  5. An Improved Model Predictive Current Controller of Switched Reluctance Machines Using Time-Multiplexed Current Sensor

    PubMed Central

    Li, Bingchu; Ling, Xiao; Huang, Yixiang; Gong, Liang; Liu, Chengliang

    2017-01-01

    This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion. Current sensor multiplexing was realized without complex adjustment of either driver circuit nor control algorithms, while it helps to reduce the cost and errors introduced in current sampling due to inconsistency between sensors. The proposed controller is validated by both simulation and experimental results with a 1.5 kW three-phase 12/8 SRM. Satisfied current sampling is received with little difference compared with independent phase current sensors for each phase. The proposed controller tracks the reference current profile as accurately as the model predictive current controller with independent phase current sensors, while having minor tracking errors compared with a hysteresis current controller. PMID:28513554

  6. Photometric and Colorimetric Assessment of LED Chip Scale Packages by Using a Step-Stress Accelerated Degradation Test (SSADT) Method

    PubMed Central

    Yu, Chaohua; Fan, Xuejun; Zhang, Guoqi

    2017-01-01

    By solving the problem of very long test time on reliability qualification for Light-emitting Diode (LED) products, the accelerated degradation test with a thermal overstress at a proper range is regarded as a promising and effective approach. For a comprehensive survey of the application of step-stress accelerated degradation test (SSADT) in LEDs, the thermal, photometric, and colorimetric properties of two types of LED chip scale packages (CSPs), i.e., 4000 °K and 5000 °K samples each of which was driven by two different levels of currents (i.e., 120 mA and 350 mA, respectively), were investigated under an increasing temperature from 55 °C to 150 °C and a systemic study of driving current effect on the SSADT results were also reported in this paper. During SSADT, junction temperatures of the test samples have a positive relationship with their driving currents. However, the temperature-voltage curve, which represents the thermal resistance property of the test samples, does not show significant variance as long as the driving current is no more than the sample’s rated current. But when the test sample is tested under an overdrive current, its temperature-voltage curve is observed as obviously shifted to the left when compared to that before SSADT. Similar overdrive current affected the degradation scenario is also found in the attenuation of Spectral Power Distributions (SPDs) of the test samples. As used in the reliability qualification, SSADT provides explicit scenes on color shift and correlated color temperature (CCT) depreciation of the test samples, but not on lumen maintenance depreciation. It is also proved that the varying rates of the color shift and CCT depreciation failures can be effectively accelerated with an increase of the driving current, for instance, from 120 mA to 350 mA. For these reasons, SSADT is considered as a suitable accelerated test method for qualifying these two failure modes of LED CSPs. PMID:29035300

  7. External beam pixe programs at the University of California, Davis

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

    Eldred, R.A.

    A PIXE system in which large or delicate samples are excited by a low-current external proton beam is described. This system has been used to analyze historical printed books and manuscripts, as well as a large variety of archeological artifacts. The steps used to protect the sample from unnecessary beam current are examined. A recent thorough study of the first volume of the Gutenberg 42-line Bible is described in some detail.

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

    Ji, Yanfeng; Hui, Fei; Shi, Yuanyuan

    The conductive atomic force microscope (CAFM) has become an essential tool for the nanoscale electronic characterization of many materials and devices. When studying photoactive samples, the laser used by the CAFM to detect the deflection of the cantilever can generate photocurrents that perturb the current signals collected, leading to unreliable characterization. In metal-coated semiconductor samples, this problem is further aggravated, and large currents above the nanometer range can be observed even without the application of any bias. Here we present the first characterization of the photocurrents introduced by the laser of the CAFM, and we quantify the amount of lightmore » arriving to the surface of the sample. The mechanisms for current collection when placing the CAFM tip on metal-coated photoactive samples are also analyzed in-depth. Finally, we successfully avoided the laser-induced perturbations using a two pass technique: the first scan collects the topography (laser ON) and the second collects the current (laser OFF). We also demonstrate that CAFMs without a laser (using a tuning fork for detecting the deflection of the tip) do not have this problem.« less

  9. Does Marital Status Influence the Parenting Styles Employed by Parents?

    ERIC Educational Resources Information Center

    Ashiono, Benard Litali; Mwoma, Teresa B.

    2015-01-01

    The current study sought to establish whether parents' marital status, influence their use of specific parenting styles in Kisauni District, Kenya. A correlational research design was employed to carry out this study. Stratified sampling technique was used to select preschools while purposive sampling technique was used to select preschool…

  10. Psychological and Social Predictors of Suicidal Ideation among Young Adolescents

    ERIC Educational Resources Information Center

    Kirkcaldy, Bruce D.; Eysenck, Michael W.; Siefen, Georg R.

    2004-01-01

    Although there is an enormous amount of literature demonstrating socio-psychological determinants of suicide and self-injurious behaviour among adults or clinical samples of children and adolescents, there is a scarcity of studies focussing on non-clinical adolescent samples. The current study examined associations between self-reported data on…

  11. Patterns of Compensatory Behaviors and Disordered Eating in College Students

    ERIC Educational Resources Information Center

    Schaumberg, Katherine; Anderson, Lisa M.; Reilly, Erin; Anderson, Drew A.

    2014-01-01

    Objective: The current study investigated rates of endorsement of eating-related compensatory behaviors within a college sample. Participants: This sample included male and female students (N = 1,158). Methods: Participants completed the Eating Disorder Examination Questionnaire (EDE-Q). The study defined 3 groups of students: those who did not…

  12. Race/Ethnicity and Self-Esteem in Families of Adolescents

    ERIC Educational Resources Information Center

    Phares, Vicky; Fields, Sherecce; Watkins-Clay, M. Monica; Kamboukos, Dimitra; Han, Sena

    2005-01-01

    Self-esteem and perceived competence have only been explored minimally in family studies with ethnically diverse samples. The current study explores self-esteem and perceived competence in a sample of adolescents, their mothers, and their fathers from three racial/ethnic groups: African American, Hispanic/Latino/Latina, and Caucasian. Results show…

  13. Race/Ethnicity and Self-Esteem in Families of Adolescents

    ERIC Educational Resources Information Center

    Phares, Vicky; Fields, Sherecce; Watkins-Clay, M. Monica; Kamboukos, Dimitra; Han, Sena

    2005-01-01

    Self-esteem and perceived competence have only been explored minimally in family studies with ethnically diverse samples. The current study explores self-esteem and perceived competence in a sample of adolescents, their mothers, and their fathers from three racial/ ethnic groups: African American, Hispanic/Latino/Latina, and Caucasian. Results…

  14. Cumulative trauma and current posttraumatic stress disorder status in general population and inmate samples.

    PubMed

    Briere, John; Agee, Elisha; Dietrich, Anne

    2016-07-01

    This research was undertaken to examine the role between cumulative exposure to different types of traumatic events and posttraumatic stress disorder (PTSD) status in general population and prison samples. Two archival datasets were examined: the standardization sample for the Detailed Assessment of Posttraumatic States (DAPS; Briere, 2001), and data from a study on trauma and posttraumatic sequelae among inmates and others. PTSD was found in 4% of the general population sample and 48% of the prison sample. Trauma exposure was very common among prisoners, including a 70% rate of childhood sexual abuse for women and a 50% rate for men. Lifetime number of different types of trauma was associated with PTSD in both the general population and prison samples, even when controlling for the effects of sexual trauma. Cumulative interpersonal trauma predicted PTSD, whereas cumulative noninterpersonal trauma did not. In the general population sample, participants who had only 1 type of trauma exposure had a 0% likelihood of current PTSD, whereas those with 6 or more other trauma types had a 12% likelihood. In the prison sample, those with only 1 type of trauma exposure had a 17% percent likelihood of current PTSD, whereas those exposed to 6 or more other trauma types had a 64% chance of PTSD. Cumulative trauma predicts current PTSD in both general population and prison samples, even after controlling for sexual trauma. PTSD appears to develop generally as a function of exposure to multiple types of interpersonal trauma, as opposed to a single traumatic event. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. The current duration design for estimating the time to pregnancy distribution: a nonparametric Bayesian perspective.

    PubMed

    Gasbarra, Dario; Arjas, Elja; Vehtari, Aki; Slama, Rémy; Keiding, Niels

    2015-10-01

    This paper was inspired by the studies of Niels Keiding and co-authors on estimating the waiting time-to-pregnancy (TTP) distribution, and in particular on using the current duration design in that context. In this design, a cross-sectional sample of women is collected from those who are currently attempting to become pregnant, and then by recording from each the time she has been attempting. Our aim here is to study the identifiability and the estimation of the waiting time distribution on the basis of current duration data. The main difficulty in this stems from the fact that very short waiting times are only rarely selected into the sample of current durations, and this renders their estimation unstable. We introduce here a Bayesian method for this estimation problem, prove its asymptotic consistency, and compare the method to some variants of the non-parametric maximum likelihood estimators, which have been used previously in this context. The properties of the Bayesian estimation method are studied also empirically, using both simulated data and TTP data on current durations collected by Slama et al. (Hum Reprod 27(5):1489-1498, 2012).

  16. Female Sexual Abuse and Criminal Justice Intervention: A Comparison of Child Protective Service and Criminal Justice Samples

    ERIC Educational Resources Information Center

    Bader, Shannon M.; Scalora, Mario J.; Casady, Thomas K.; Black, Shannon

    2008-01-01

    Objective: The current study compared a sample of female perpetrators reported to Child Protective Services (CPS) to a sample of women from the criminal justice system. Instead of examining a clinical or criminal justice sample in isolation, this comparison allows a more accurate description of female sexual offending. Methods: Cases were drawn…

  17. Two-dimensional numerical simulation of boron diffusion for pyramidally textured silicon

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

    Ma, Fa-Jun, E-mail: Fajun.Ma@nus.edu.sg; Duttagupta, Shubham; Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117576

    2014-11-14

    Multidimensional numerical simulation of boron diffusion is of great relevance for the improvement of industrial n-type crystalline silicon wafer solar cells. However, surface passivation of boron diffused area is typically studied in one dimension on planar lifetime samples. This approach neglects the effects of the solar cell pyramidal texture on the boron doping process and resulting doping profile. In this work, we present a theoretical study using a two-dimensional surface morphology for pyramidally textured samples. The boron diffusivity and segregation coefficient between oxide and silicon in simulation are determined by reproducing measured one-dimensional boron depth profiles prepared using different boronmore » diffusion recipes on planar samples. The established parameters are subsequently used to simulate the boron diffusion process on textured samples. The simulated junction depth is found to agree quantitatively well with electron beam induced current measurements. Finally, chemical passivation on planar and textured samples is compared in device simulation. Particularly, a two-dimensional approach is adopted for textured samples to evaluate chemical passivation. The intrinsic emitter saturation current density, which is only related to Auger and radiative recombination, is also simulated for both planar and textured samples. The differences between planar and textured samples are discussed.« less

  18. Factors Affecting the Unemployment (Rate) of Female Art Graduates in Iran

    ERIC Educational Resources Information Center

    Hedayat, Mina; Kahn, Sabzali Musa; Hanafi, Jaffri

    2013-01-01

    The aim of this study is to explore the relationship between the opportunities of female artist graduates in Tehran Province and the current employment market. Mixed method was employed in this study. The population of the current study consisted of 240 female artist graduates selected using a systematic random sampling method from both public and…

  19. Structural and critical current properties in Al-doped MgB 2

    NASA Astrophysics Data System (ADS)

    Zheng, D. N.; Xiang, J. Y.; Lang, P. L.; Li, J. Q.; Che, G. C.; Zhao, Z. W.; Wen, H. H.; Tian, H. Y.; Ni, Y. M.; Zhao, Z. X.

    2004-08-01

    A series of Al-doped Mg 1- xAl xB 2 samples have been fabricated and systematic study on structure and superconducting properties have been carried out for the samples. In addition to a structural transition observed by XRD, TEM micrographs showed the existence of a superstructure of double c-axis lattice constant along the direction perpendicular to the boron honeycomb sheet. In order to investigate the effect of Al doping on flux pinning and critical current properties in MgB 2, measurements on the superconducting transition temperature Tc, irreversible field Birr and critical current density Jc were performed too, for the samples with the doping levels lower than 0.15 in particular. These experimental observations were discussed in terms of Al doping induced changes in carrier concentration.

  20. The Croydon Assessment of Learning Study: Prevalence and Educational Identification of Mild Mental Retardation

    ERIC Educational Resources Information Center

    Simonoff, Emily; Pickles, Andrew; Chadwick, Oliver; Gringras, Paul; Wood, Nicky; Higgins, Siobhan; Maney, Julie-Ann; Karia, Nisha; Iqbal, Huma; Moore, Anne

    2006-01-01

    Background: Mild mental retardation is an enduring and impairing condition. Its prevalence has varied widely across different studies from 0.5 to over 8%, with higher rates in completely ascertained samples. The current study estimates the prevalence of low IQ in the mental retardation range (intellectual disability) in a population sample and…

  1. The Effect of Environmental Science Projects on Students' Environmental Knowledge and Science Attitudes

    ERIC Educational Resources Information Center

    Al-Balushi, Sulaiman M.; Al-Aamri, Shamsa S.

    2014-01-01

    The current study explores the effectiveness of involving students in environmental science projects for their environmental knowledge and attitudes towards science. The study design is a quasi-experimental pre-post control group design. The sample was 62 11th-grade female students studying at a public school in Oman. The sample was divided into…

  2. Comparing Microbiome Sampling Methods in a Wild Mammal: Fecal and Intestinal Samples Record Different Signals of Host Ecology, Evolution

    PubMed Central

    Ingala, Melissa R.; Simmons, Nancy B.; Wultsch, Claudia; Krampis, Konstantinos; Speer, Kelly A.; Perkins, Susan L.

    2018-01-01

    The gut microbiome is a community of host-associated symbiotic microbes that fulfills multiple key roles in host metabolism, immune function, and tissue development. Given the ability of the microbiome to impact host fitness, there is increasing interest in studying the microbiome of wild animals to better understand these communities in the context of host ecology and evolution. Human microbiome research protocols are well established, but wildlife microbiome research is still a developing field. Currently, there is no standardized set of best practices guiding the collection of microbiome samples from wildlife. Gut microflora are typically sampled either by fecal collection, rectal swabbing, or by destructively sampling the intestinal contents of the host animal. Studies rarely include more than one sampling technique and no comparison of these methods currently exists for a wild mammal. Although some studies have hypothesized that the fecal microbiome is a nested subset of the intestinal microbiome, this hypothesis has not been formally tested. To address these issues, we examined guano (feces) and distal intestinal mucosa from 19 species of free-ranging bats from Lamanai, Belize, using 16S rRNA amplicon sequencing to compare microbial communities across sample types. We found that the diversity and composition of intestine and guano samples differed substantially. In addition, we conclude that signatures of host evolution are retained by studying gut microbiomes based on mucosal tissue samples, but not fecal samples. Conversely, fecal samples retained more signal of host diet than intestinal samples. These results suggest that fecal and intestinal sampling methods are not interchangeable, and that these two microbiotas record different information about the host from which they are isolated. PMID:29765359

  3. Comparing Microbiome Sampling Methods in a Wild Mammal: Fecal and Intestinal Samples Record Different Signals of Host Ecology, Evolution.

    PubMed

    Ingala, Melissa R; Simmons, Nancy B; Wultsch, Claudia; Krampis, Konstantinos; Speer, Kelly A; Perkins, Susan L

    2018-01-01

    The gut microbiome is a community of host-associated symbiotic microbes that fulfills multiple key roles in host metabolism, immune function, and tissue development. Given the ability of the microbiome to impact host fitness, there is increasing interest in studying the microbiome of wild animals to better understand these communities in the context of host ecology and evolution. Human microbiome research protocols are well established, but wildlife microbiome research is still a developing field. Currently, there is no standardized set of best practices guiding the collection of microbiome samples from wildlife. Gut microflora are typically sampled either by fecal collection, rectal swabbing, or by destructively sampling the intestinal contents of the host animal. Studies rarely include more than one sampling technique and no comparison of these methods currently exists for a wild mammal. Although some studies have hypothesized that the fecal microbiome is a nested subset of the intestinal microbiome, this hypothesis has not been formally tested. To address these issues, we examined guano (feces) and distal intestinal mucosa from 19 species of free-ranging bats from Lamanai, Belize, using 16S rRNA amplicon sequencing to compare microbial communities across sample types. We found that the diversity and composition of intestine and guano samples differed substantially. In addition, we conclude that signatures of host evolution are retained by studying gut microbiomes based on mucosal tissue samples, but not fecal samples. Conversely, fecal samples retained more signal of host diet than intestinal samples. These results suggest that fecal and intestinal sampling methods are not interchangeable, and that these two microbiotas record different information about the host from which they are isolated.

  4. A Review of Biological Agent Sampling Methods and ...

    EPA Pesticide Factsheets

    Report This study was conducted to evaluate current sampling and analytical capabilities, from a time and resource perspective, for a large-scale biological contamination incident. The analysis will be useful for strategically directing future research investment.

  5. Study of current-voltage characteristics of ferromagnetic α-Fe{sub 1.64}Ga{sub 0.36}O{sub 3} oxide under magnetic fields

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

    Vijayasri, G., E-mail: vsvijiguna.physics@gmail.com; Bhowmik, R. N.

    We report the influence of magnetic field on I-V characteristics of α-Fe{sub 1.64}Ga{sub 0.36}O{sub 3} sample. Synchrotron X-ray diffraction pattern and Raman Spectroscopy have confirmed rhombohedral structure with space group R3C in the sample. The sample exhibits ferromagnetic feature at room temperature and non saturation of magnetization up to 7Tesla suggests the effect of non-collinear structure (canting) of the spins on the ferromagnetic properties. We have recorded I-V characteristics of the sample under magnetic field to study the effect of non-collinear spin structure on the electrical properties. Space charge limited current mechanism controlled the nature of non-linear I-V curves andmore » the curves are significantly affected by magnetic field.« less

  6. Ethnic status and engagement with health services: Attitudes toward help-seeking and intercultural willingness to interact among South East Asian students in Australia.

    PubMed

    Logan, Shanna; Steel, Zachary; Hunt, Caroline

    2017-04-01

    Previous research has demonstrated the importance of intercultural willingness to interact; however, these investigations have yet to be applied to a health context or to compare an ethnic minority with a majority sample. Consequently, the current study sought to better understand engagement with health services by investigating both attitudes towards seeking psychological help and intercultural willingness to interact within an ethnic minority South East Asian population, relative to an Anglo Australian sample. As predicted, negative attitudes towards seeking psychological help were higher in the South East Asian sample, with this relationship persisting across generations, despite significant differences in acculturation. In contrast, intercultural willingness to interact was not associated with ethnicity status but was associated with higher anxiety, uncertainty, ethnocentrism and help-seeking, consistent with current empirical and theoretical literature. The current study also sought to examine factors associated with help-seeking attitudes and found that ethnocentrism was a significant predictor, when accounting for previous health experience.

  7. Groundwater quality in the Delaware and St. Lawrence River Basins, New York, 2010

    USGS Publications Warehouse

    Nystrom, Elizabeth A.

    2012-01-01

    Water quality in both study areas is generally good, but concentrations of some constituents equaled or exceeded current or proposed Federal or New York State drinking-water standards. The standards exceeded are color (one sample in the St. Lawrence study area), pH (three samples in the Delaware study area), sodium (one sample in the St. Lawrence study area), total dissolved solids (one sample in the St. Lawrence study area), aluminum (one sample in the Delaware study area and one sample in the St. Lawrence study area), iron (seven samples in the St. Lawrence study area), manganese (one sample in the Delaware study area and five samples in the St. Lawrence study area), gross alpha radioactivity (one sample in the St. Lawrence study area), radon-222 (10 samples in the Delaware study area and 14 samples in the St. Lawrence study area), and bacteria (5 samples in the Delaware study area and 10 samples in the St. Lawrence study area). E. coli bacteria were detected in samples from two wells in the St. Lawrence study area. Concentrations of chloride, fluoride, sulfate, nitrate, nitrite, antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury, selenium, silver, thallium, zinc, and uranium did not exceed existing drinking-water standards in any of the samples collected.

  8. Extended Task Space Control for Robotic Manipulators

    NASA Technical Reports Server (NTRS)

    Backes, Paul G. (Inventor); Long, Mark K. (Inventor)

    1996-01-01

    The invention is a method of operating a robot in successive sampling intervals to perform a task, the robot having joints and joint actuators with actuator control loops, by decomposing the task into behavior forces, accelerations, velocities and positions of plural behaviors to be exhibited by the robot simultaneously, computing actuator accelerations of the joint actuators for the current sampling interval from both behavior forces, accelerations velocities and positions of the current sampling interval and actuator velocities and positions of the previous sampling interval, computing actuator velocities and positions of the joint actuators for the current sampling interval from the actuator velocities and positions of the previous sampling interval, and, finally, controlling the actuators in accordance with the actuator accelerations, velocities and positions of the current sampling interval. The actuator accelerations, velocities and positions of the current sampling interval are stored for use during the next sampling interval.

  9. BIASES IN CASTNET FILTER PACK RESULTS ASSOCIATED WITH SAMPLING PROTOCOL

    EPA Science Inventory

    In the current study, single filter weekly (w) results are compared with weekly results aggregated from day and night (dn) weekly samples. Comparisons of the two sampling protocols for all major constituents (SO42-, NO3-, NH4+, HNO3, and SO2) show median bias (MB) of < 5 nmol m-3...

  10. An Aspect of the Capability for Suicide-Fearlessness of the Pain Involved in Dying-Amplifies the Association Between Suicide Ideation and Attempts.

    PubMed

    Smith, Phillip N; Stanley, Ian H; Joiner, Thomas E; Sachs-Ericsson, Natalie J; Van Orden, Kimberly A

    2016-01-01

    The interpersonal theory of suicide posits that individuals who experience suicide ideation will only develop suicidal intent, and subsequently engage in suicidal behavior when they have concomitant fearlessness about death and tolerance for physical pain (i.e., the capability for suicide). The current studies examined the hypothesis that one aspect of the capability for suicide-fearlessness of the pain involved in dying-would amplify the positive association between current suicide ideation and a previous suicide attempt in two samples at high risk for experiencing suicide ideation and suicide attempts. Study 1 examined this relation using self-report methods in a sample of adults entering treatment in a mental health outpatient clinic. Study 2 utilized similar methods in a sample of adults admitted to inpatient psychiatry. Both studies indicated that those individuals who reported suicide ideation were more likely than non-ideators to report having attempted suicide only if they also reported greater fearlessness of the pain involved in dying. The current findings support the theorized role of the capability for suicide in the transition from ideation to attempt and also support assessing the capability for suicide in risk assessment.

  11. Transport properties of kA class QMG current limiting elements

    NASA Astrophysics Data System (ADS)

    Morita, M.; Miura, O.; Ito, D.

    2001-09-01

    In order to estimate the feasibility of a resistive type fault current limiter made of QMG, transport properties of QMG current limiting elements which can transport about 1 kA continuously in a superconducting state were studied. QMG is a rare earth based bulk superconductor that has high Jc properties and relatively high electrical resistivity in a normal state. Because of these properties, QMG is a promising bulk material for superconducting fault current limiter applications. A bar-shaped sample in which the cross-section and the effective length were 2.2×0.8 mm2 and 30 mm, respectively, was prepared. Bypass resistance of 7 mΩ was connected in parallel with the sample. A field assist mechanism that can apply a magnetic field of about 0.9 T to the sample was installed. A half cycle of AC current up to about 3 kA was applied to the samples at 77 K. In the case when applied current ( I) was less than 1000 A in a self-field, flux flow voltage was less than 0.5 mV. The n-value was about 6. In the applied field of 0.9 T, a rapid increase of voltage (quench) was observed around I=1820 A. The quench phenomena reproduced without degradation in the case of I>1820 A. From these results, it was found that QMG fault current elements can endure the thermal shock of the quench by the optimization of bypass resistance and the applied field.

  12. Examining Validity of Sources of Mathematics Self-Efficacy Scale in Turkey

    ERIC Educational Resources Information Center

    Kandemir, Mehmet Ali; Akbas-Perkmen, Rahile

    2017-01-01

    The main purpose of the current study is to examine the construct, convergent and discriminant validity of the Sources of Mathematics Self-Efficacy Scale (Usher & Pajares, 2009) in a Turkish sample. Bandura's Social Cognitive Theory (1986) served as the theoretical framework for the current study. According to Bandura (1986), people's…

  13. A Study of Arizona's Teachers of English Language Learners

    ERIC Educational Resources Information Center

    Rios-Aguilar, Cecilia; Gonzalez-Canche, Manuel; Moll, Luis C.

    2010-01-01

    In this study a representative sample of 880 elementary and secondary teachers currently teaching in 33 schools across the state of Arizona were asked about their perceptions of how their ELL students were faring under current instructional policies for ELL students. Teachers were surveyed during the Spring of 2010. Overall findings show that most…

  14. Logging utilization in Idaho: Current and past trends

    Treesearch

    Eric A. Simmons; Todd A. Morgan; Erik C. Berg; Stanley J. Zarnoch; Steven W. Hayes; Mike T. Thompson

    2014-01-01

    A study of commercial timber-harvesting activities in Idaho was conducted during 2008 and 2011 to characterize current tree utilization, logging operations, and changes from previous Idaho logging utilization studies. A two-stage simple random sampling design was used to select sites and felled trees for measurement within active logging sites. Thirty-three logging...

  15. The Current State of Sustainability in Bioscience Laboratories: A Statistical Examination of a UK Tertiary Institute

    ERIC Educational Resources Information Center

    Wright, Hazel A.; Ironside, Joseph E.; Gwynn-Jones, Dylan

    2008-01-01

    Purpose: This study aims to identify the current barriers to sustainability in the bioscience laboratory setting and to determine which mechanisms are likely to increase sustainable behaviours in this specialised environment. Design/methodology/approach: The study gathers qualitative data from a sample of laboratory researchers presently…

  16. Is Childhood Physical Abuse Associated with Peptic Ulcer Disease? Findings from a Population-Based Study

    ERIC Educational Resources Information Center

    Fuller-Thomson, Esme; Bottoms, Jennifer; Brennenstuhl, Sarah; Hurd, Marion

    2011-01-01

    This study investigated childhood physical abuse and ulcers in a regionally representative community sample. Age, race and sex were controlled for in addition to five clusters of potentially confounding factors: adverse childhood conditions, adult socioeconomic status, current health behaviors, current stress and marital status, and history of…

  17. The Devalued Student: Misalignment of Current Mathematics Knowledge and Level of Instruction

    ERIC Educational Resources Information Center

    LeMire, Steven D.; Melby, Marcella L.; Haskins, Anne M.; Williams, Tony

    2012-01-01

    Within this study, we investigated the association between 10th-grade students' mathematics performance and their feelings of instructional misalignment between their current mathematics knowledge and educator support. Data from the 2002 Education Longitudinal Study, which included a national sample of 750 public and private high schools in the…

  18. SAMPLING LARGE RIVERS FOR ALGAE, BENTHIC MACROINVERTEBRATES AND FISH

    EPA Science Inventory

    Multiple projects are currently underway to increase our understanding of the effects of different sampling methods and designs used for the biological assessment and monitoring of large (boatable) rivers. Studies include methods used to assess fish, benthic macroinvertebrates, ...

  19. Electrofishing and the effects of depletion sampling on fish health: A review and recommendations for additional study

    USGS Publications Warehouse

    Panek, F.M.; Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    2011-01-01

    Depletion sampling in combination with multiple-pass electrofishing is an important fisheries management tool for wadeable streams. This combination of techniques has been used routinely by federal and state fishery management agencies for several decades as a reliable means to obtain quantitative data on trout populations or to describe fish community structure. In this paper we review the effects of electrofishing on fish and discuss this within the context of depletion sampling and multiple exposures of fishes to electric fields. The multiple wave forms most commonly used in sampling (alternating current, direct current, and pulsed direct current) are discussed as well as electrofishing induced response, injury and physiological stress. Fish that survive electrofishing injuries are more likely to suffer short and long-term adverse effects to their behavior, health, growth, or reproduction. Of greatest concern are the native, non-target species that may be subjected to multiple electrical shocks during the course of a 3-pass depletion survey. These exposures and their effects on the non-target species warrant further study as do the overall effects of electrofishing on populations and community structure. 

  20. Parenthood and the Quality of Experience in Daily Life: A Longitudinal Study

    ERIC Educational Resources Information Center

    Fave, Antonella Delle; Massimini, Fausto

    2004-01-01

    This longitudinal study analyzes the time budget and the quality of experience reported by new parents. Five primiparous couples were repeatedly administered Experience Sampling Method. They carried pagers sending random signals 6-8 times a day; at the signal reception, they filled out forms sampling current thoughts, activities, and the quality…

  1. Sexual Orientation and School Discipline: New Evidence from a Population-Based Sample

    ERIC Educational Resources Information Center

    Mittleman, Joel

    2018-01-01

    Sexual minorities' risk for exclusionary discipline is a commonly cited indicator of the challenges that these students face. The current study addresses this issue by introducing a new data source for research on sexual minority students: the Fragile Families and Childhood Wellbeing Study. In this geographically diverse, population-based sample,…

  2. Childhood Giftedness and Adulthood Genius: A Historiometric Analysis of 291 Eminent African Americans

    ERIC Educational Resources Information Center

    Simonton, Dean Keith

    2008-01-01

    Although the association between giftedness and genius has been the subject of several retrospective, longitudinal, and historiometric studies, this research concentrated on majority-culture samples. In the current study, Cox's (1926) findings regarding 301 geniuses were replicated on a sample of 291 eminent African Americans. Relative genius was…

  3. MMPI-2 Characteristics of the Old Order Amish: A Comparison of Clinical, Nonclinical, and United States Normative Samples

    ERIC Educational Resources Information Center

    Knabb, Joshua J.; Vogt, Ronald G.; Newgren, Kevin P.

    2011-01-01

    In the current study, we investigated Minnesota Multiphasic Personality Inventory-2 (MMPI-2) characteristics in an Old Order Amish nonclinical sample (N = 84), comparing these data with both the United States normative sample (N = 2,600) and a sample of Old Order Amish outpatients (N = 136). Consistent with our hypothesis, the Old Order Amish…

  4. Study on electrical current variations in electromembrane extraction process: Relation between extraction recovery and magnitude of electrical current.

    PubMed

    Rahmani, Turaj; Rahimi, Atyeh; Nojavan, Saeed

    2016-01-15

    This contribution presents an experimental approach to improve analytical performance of electromembrane extraction (EME) procedure, which is based on the scrutiny of current pattern under different extraction conditions such as using different organic solvents as supported liquid membrane, electrical potentials, pH values of donor and acceptor phases, variable extraction times, temperatures, stirring rates, different hollow fiber lengths and the addition of salts or organic solvents to the sample matrix. In this study, four basic drugs with different polarities were extracted under different conditions with the corresponding electrical current patterns compared against extraction recoveries. The extraction process was demonstrated in terms of EME-HPLC analyses of selected basic drugs. Comparing the obtained extraction recoveries with the electrical current patterns, most cases exhibited minimum recovery and repeatability at the highest investigated magnitude of electrical current. . It was further found that identical current patterns are associated with repeated extraction efficiencies. In other words, the pattern should be repeated for a successful extraction. The results showed completely different electrical currents under different extraction conditions, so that all variable parameters have contributions into the electrical current pattern. Finally, the current patterns of extractions from wastewater, plasma and urine samples were demonstrated. The results indicated an increase in the electrical current when extracting from complex matrices; this was seen to decrease the extraction efficiency. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. The Study Habits of Finnish College Students: A Two Sample Investigation

    ERIC Educational Resources Information Center

    Ludlum, Marty; Hongell, Linn; Tigerstedt, Christa; Alsobrook, Laura

    2016-01-01

    This research details surveys of current Finnish college students and their study habits. In the current project, we surveyed two distinct sets of students in the spring of 2012 (n = 74), and in the spring of 2014 (n = 119). We found that the students studied less than 9 hours per week. We found significant differences between students' study…

  6. Evaluation of Classroom Teachers' Opinions about In-Service Training (The Case of Mugla)

    ERIC Educational Resources Information Center

    Aykaç, Necdet; Yildirim, Kasim

    2017-01-01

    The current study aimed to evaluate the classroom teachers' opinions about in-service training process. Thus, the current study was designed as a descriptive case study. A total of 28 classroom teachers constituted the sample group of the research. The research process was carried out on the classroom teachers working in state elementary schools…

  7. Dendritic Ag-Fe nanocrystalline alloy synthesized by pulsed electrodeposition and its characterization

    NASA Astrophysics Data System (ADS)

    Santhi, Kalavathy; Revathy, T. A.; Narayanan, V.; Stephen, A.

    2014-10-01

    Synthesis of dendrite shaped Ag-Fe alloy nanomaterial by pulsed electrodeposition route was investigated. The alloy samples were deposited at different current densities from electrolytes of different compositions to study the influence of current density and bath composition on metal contents in the alloy, which was determined by ICP-OES analysis. The XRD studies were carried out to determine the structure of these samples. Magnetic characterization at room temperature and during heating was carried out to understand their magnetic behaviour and to confirm the inferences drawn from the XRD results. The XPS spectra proved the presence of Fe and Ag in the metallic form in the alloy samples. The FESEM and TEM micrographs were taken to view the surface morphology of the nanosized particles.

  8. Risky business: a longitudinal study examining cigarette smoking initiation among susceptible and non-susceptible e-cigarette users in Canada.

    PubMed

    Aleyan, Sarah; Cole, Adam; Qian, Wei; Leatherdale, Scott T

    2018-05-26

    Given that many adolescent e-cigarette users are never-smokers, the possibility that e-cigarettes may act as a gateway to future cigarette smoking has been discussed in various studies. Longitudinal data are needed to explore the pathway between e-cigarette and cigarette use, particularly among different risk groups including susceptible and non-susceptible never-smokers. The objective of this study was to examine whether baseline use of e-cigarettes among a sample of never-smoking youth predicted cigarette smoking initiation over a 2-year period. Longitudinal cohort study. 89 high schools across Ontario and Alberta, Canada. A sample of grade 9-11 never-smoking students at baseline (n=9501) who participated in the COMPASS study over 2 years. Participants completed in-class questionnaires that assessed smoking susceptibility and smoking initiation. Among the baseline sample of non-susceptible never-smokers, 45.2% of current e-cigarette users reported trying a cigarette after 2 years compared with 13.5% of non-current e-cigarette users. Among the baseline sample of susceptible never-smokers, 62.4% of current e-cigarette users reported trying a cigarette after 2 years compared with 36.1% of non-current e-cigarette users. Overall, current e-cigarette users were more likely to try a cigarette 2 years later. This association was stronger among the sample of non-susceptible never-smokers (AOR=5.28, 95% CI 2.81 to 9.94; p<0.0001) compared with susceptible never-smokers (AOR=2.78, 95% CI 1.84 to 4.20; p<0.0001). Findings from this large, longitudinal study support public health concerns that e-cigarette use may contribute to the development of a new population of cigarette smokers. They also support the notion that e-cigarettes are expanding the tobacco market by attracting low-risk youth who would otherwise be unlikely to initiate using cigarettes. Careful consideration will be needed in developing an appropriate regulatory framework that prevents e-cigarette use among youth. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Reading in Able and Disabled Readers from around the World: Same or Different? An Illustration from a Study of Reading-Related Processes in a Swahili Sample of Siblings

    ERIC Educational Resources Information Center

    Grigorenko, Elena L.; Ngorosho, Damaris; Jukes, Matthew; Bundy, Donald

    2006-01-01

    In this article, we discuss two characteristics of the majority of current behaviour- and molecular-genetic studies of reading ability and disability, specifically, the ascertainment strategies and the populations from which samples are selected. In the context of this discussion, we present data that we collected on a sample of Swahili-speaking…

  10. Fate of sputum samples transported in bottles containing cetylpyridinium chloride and sodium chloride: a national reference laboratory study.

    PubMed

    Visalakshi, Potharaju; Meharwal, Sandeep K; Arora, Jyoti; Bhalla, Manpreet; Singh, Niti; Myneedu, Vithal Prasad; Behera, Digamber

    2012-04-01

    The transportation of sputum samples may sometimes take more than one week which results in an increased contamination rate and loss of positive cultures. The current study was planned to analyze the recovery rate of mycobacteria from transported samples with and without Cetylpyridinium chloride (CPC). Addition of CPC is useful for isolation of M. tuberculosis from sputum subjected to long-term storage.

  11. Illicit Drug Use Among South Korean Offenders: Assessing the Generality of Social Learning Theory.

    PubMed

    Yun, Minwoo; Kim, Eunyoung

    2015-10-01

    Since the mid-1990s, illicit drug use has become a problem in Korean society. This trend is likely due to the rapid globalization and expansion that occurred with the Internet revolution, which led to greater numbers of people socially learning about drug culture. The current study attempts to uncover criminogenic causality of such social learning about drug use by studying adult felony drug offenders in South Korea. The data used for the study were obtained from self-reported surveys, originally collected by the Korean Institution of Criminology (KIC). The final sample comprised 1,452 felony offenders convicted of illicit drug use, and their responses were analyzed with a set of multiple logistic regression tests. The current study found supportive evidence for the generalizability of social learning theory from the sample of the South Korean adult drug offenders. We argue that the current study provides additional empirical evidence that supports the generalizability of social learning theory. © The Author(s) 2014.

  12. The scanning cryomacroscope - A device prototype for the study of cryopreservation

    NASA Astrophysics Data System (ADS)

    Feig, Justin S. G.; Rabin, Yoed

    2014-07-01

    A new cryomacroscope prototype-a visualization device for the in situ analysis of cryopreserved biological samples-is presented in the current study. In order to visualize samples larger than the field of view of the optical setup, a scanning mechanism is integrated into the system, which represents a key improvement over previous cryomacroscope prototypes. Another key feature of the new design is in its compatibility with available top-loading controlled-rate cooling chambers, which eliminates the need for a dedicated cooling mechanism. The objective for the current development is to create means to generate a single digital movie of an experimental investigation, with all relevant data overlaid. The visualization capabilities of the scanning cryomacroscope are demonstrated in the current study on the cryoprotective agent dimethyl sulfoxide and the cryoprotective cocktail DP6. Demonstrated effects include glass formation, various regimes of crystallization, thermal contraction, and fracture formation.

  13. Prevalence of Sexual Dysfunctions

    PubMed Central

    Simons, Jeffrey; Carey, Michael P.

    2008-01-01

    Ten years of research that has provided data regarding the prevalence of sexual dysfunctions is reviewed. A thorough review of the literature identified 52 studies that have been published in the 10 years since an earlier review by Spector and Carey (1990). Community samples indicate a current prevalence of 0 - 3% for male orgasmic disorder, 0 - 5% for erectile disorder, and 0 - 3% for male hypoactive sexual desire disorder. Pooling current and 1-year figures provides community prevalence estimates of 7 - 10% for female orgasmic disorder and 4 - 5% for premature ejaculation. Stable community estimates of the current prevalence for the other sexual dysfunctions remain unavailable. Prevalence estimates obtained from primary care and sexuality clinic samples are characteristically higher. Although a relatively large number of studies have been conducted since Spector and Carey’s (1990) review, the lack of methodological rigor of many studies limits the confidence that can be placed in these findings. PMID:11329727

  14. Encouragement of Early Academic Skills at Home during Early Childhood Period: Validity and Reliability Study of the EASYC Scale

    ERIC Educational Resources Information Center

    Kara, H. Gözde Ertürk; Çoksoyluer, Seyda Kiliç

    2017-01-01

    The current study aims to perform the adaptation of the Encouragement of Academic Skills of Young Children (EASYC) Scale into Turkish. The study group was determined by means of the convenience sampling technique. A total of 124 students aged at 48-84 months were included in the sampling of the study. The data collection tools of the study are the…

  15. STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

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

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples resultsmore » [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).« less

  16. STATISTICAL ANALYSIS OF TANK 19F FLOOR SAMPLE RESULTS

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

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 19F as per the statistical sampling plan developed by Harris and Shine. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples resultsmore » to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL95%) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current scrape sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 19F. The uncertainty is quantified in this report by an UCL95% on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL95% was based entirely on the six current scrape sample results (each averaged across three analytical determinations).« less

  17. Studies of Current Induced Magnetization reversal and generation of GHz radiation in magnetic nanopillars

    NASA Astrophysics Data System (ADS)

    Alhajdarwish, Mustafa Yousef

    This thesis describes studies of two phenomena: Current-Induced Magnetization Switching (CIMS), and Current-Induced Generation of GHz Radiation. The CIMS part contains results of measurements of current-perpendicular-to-plane (CPP) magnetoresistance (MR) and CIMS behavior on Ferromagnetic/Nonmetal/Ferromagnetic (F1/N/F2) nanopillars. Judicious combinations of F1 and F2 metals with different bulk scattering asymmetries, and with F1/N and N/F2 interfaces having different interfacial scattering asymmetries, are shown to be able to controllably, and independently, 'invert' both the CPP-MR and the CIMS. In 'normal' CPP-MR, R(AP) > R(P), where R(AP) and R(P) are the nanopillar resistances for the anti-parallel (AP) and parallel (P) orientations of the Fi and F2 magnetic moments. In 'inverse' CPP-MR, R(P) > R(AP). In 'normal' CIMS, positive current switches the nanopillar from the P to the AP state. In 'inverse' CIMS, positive current switches the nanopillar from AP to P. All four possible combinations of CPP-MR and CIMS---(a) 'normal'-'normal', (b) 'normal'- 'inverse', 'inverse'-'normal', and (d) 'inverse'-'inverse' are shown and explained. These results rule out the self-Oersted field as the switching source, since the direction of that field is independent of the bulk or interfacial scattering asymmetries. Successful use of impurities to reverse the bulk scattering asymmetry shows the importance of scattering off of impurities within the bulk F1 and F2 metals---i.e. that the transport must be treated as 'diffusive' rather than 'ballistic'. The GHz studies consist of five parts: (1) designing a sample geometry that allows reliable measurements; (2) making nanopillar samples with this geometry; (3) constructing a system for measuring frequencies up to 12 GHz and measuring current-driven GHz radiation data with it; (4) showing 'scaling' behavior of GHz data with the critical fields and currents for nominally identical (but actually slightly different) samples, and justifying such scaling; and (5) designing and constructing a system for frequency domain studies up to 40 GHz and for time domain studies.

  18. Bulk charging and breakdown in electron-irradiated polymers

    NASA Technical Reports Server (NTRS)

    Frederickson, A. R.

    1981-01-01

    High energy electron irradiations were performed in an experimental and theoretical study of ten common polymers. Breakdowns were monitored by measuring currents between the electrodes on each side of the planar samples. Sample currents as a function of time during irradiation are compared with theory. Breakdowns are correlated with space charge electric field strength and polarity. Major findings include evidence that all polymers tested broke down, breakdowns remove negligible bulk charge and no breakdowns are seen below 20 million V/m.

  19. Evaluation of beef trim sampling methods for detection of Shiga toxin-producing Escherichia coli (STEC)

    USDA-ARS?s Scientific Manuscript database

    Presence of Shiga toxin-producing Escherichia coli (STEC) is a major concern in ground beef. Several methods for sampling beef trim prior to grinding are currently used in the beef industry. The purpose of this study was to determine the efficacy of the sampling methods for detecting STEC in beef ...

  20. Damage to metallic samples produced by measured lightning currents

    NASA Technical Reports Server (NTRS)

    Fisher, Richard J.; Schnetzer, George H.

    1991-01-01

    A total of 10 sample disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are atypical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing current of submedian amplitude and duration, and full penetration of a 35-mil steel sample occurred under an eightieth percentile continuing current. The primary purpose of the data acquired in these experiments is for use in improving and quantifying the fidelity of laboratory simulations of lightning burnthrough.

  1. Sample size in studies on diagnostic accuracy in ophthalmology: a literature survey.

    PubMed

    Bochmann, Frank; Johnson, Zoe; Azuara-Blanco, Augusto

    2007-07-01

    To assess the sample sizes used in studies on diagnostic accuracy in ophthalmology. Design and sources: A survey literature published in 2005. The frequency of reporting calculations of sample sizes and the samples' sizes were extracted from the published literature. A manual search of five leading clinical journals in ophthalmology with the highest impact (Investigative Ophthalmology and Visual Science, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology and British Journal of Ophthalmology) was conducted by two independent investigators. A total of 1698 articles were identified, of which 40 studies were on diagnostic accuracy. One study reported that sample size was calculated before initiating the study. Another study reported consideration of sample size without calculation. The mean (SD) sample size of all diagnostic studies was 172.6 (218.9). The median prevalence of the target condition was 50.5%. Only a few studies consider sample size in their methods. Inadequate sample sizes in diagnostic accuracy studies may result in misleading estimates of test accuracy. An improvement over the current standards on the design and reporting of diagnostic studies is warranted.

  2. Space charge dynamic of irradiated cyanate ester/epoxy at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Wang, Shaohe; Tu, Youping; Fan, Linzhen; Yi, Chengqian; Wu, Zhixiong; Li, Laifeng

    2018-03-01

    Glass fibre reinforced polymers (GFRPs) have been widely used as one of the main electrical insulating structures for superconducting magnets. A new type of GFRP insulation material using cyanate ester/epoxy resin as a matrix was developed in this study, and the samples were irradiated by Co-60 for 1 MGy and 5 MGy dose. Space charge distributed within the sample were tested using the pulsed electroacoustic method, and charge concentration was found at the interfaces between glass fibre and epoxy resin. Thermally stimulated current (TSC) and dc conduction current were also tested to evaluate the irradiation effect. It was supposed that charge mobility and density were suppressed at the beginning due to the crosslinking reaction, and for a higher irradiation dose, molecular chain degradation dominated and led to more sever space charge accumulation at interfaces which enhance the internal electric field higher than the external field, and transition field for conduction current was also decreased by irradiation. Space charge dynamic at cryogenic temperature was revealed by conduction current and TSC, and space charge injection was observed for the irradiated samples at 225 K, which was more obvious for the irradiated samples.

  3. A Longitudinal Study of Early Adolescent Precursors to Running Away

    ERIC Educational Resources Information Center

    Tyler, Kimberly A.; Bersani, Bianca E.

    2008-01-01

    Although previous research has examined correlates of running away among samples of currently homeless and runaway adolescents, little is known about what factors will predict the likelihood that a housed adolescent with no prior history of running away will leave home. As such, the current study uses the National Longitudinal Survey of Youth to…

  4. 76 FR 6598 - Notice of Intent To Request Revision and Extension of a Currently Approved Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-07

    ... Clearance for Survey Research Studies. Revision to burden hours may be needed due to changes in the size of the target population, sampling design, and/or questionnaire length. DATES: Comments on this notice... Survey Research Studies. OMB Control Number: 0535-0248. Type of Request: To revise and extend a currently...

  5. 77 FR 75120 - Notice of Intent To Request Revision and Extension of a Currently Approved Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ... Clearance for Survey Research Studies. Revision to burden hours will be needed due to changes in the size of the target population, sampling design, and/or questionnaire length. DATES: Comments on this notice... Survey Research Studies. OMB Control Number: 0535-0248. Type of Request: To revise and extend a currently...

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

    ERIC Educational Resources Information Center

    Bikar, Somaye; Marziyeh, Afsaneh; Pourghaz, Abdolwahab

    2018-01-01

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

  7. The Classification Accuracy of the Minnesota Multiphasic Personality Inventory--Adolescent: Effects of Modifying the Normative Sample

    ERIC Educational Resources Information Center

    Hand, Cynthia G.; Archer, Robert P.; Handel, Richard W.; Forbey, Johnathan D.

    2007-01-01

    Numerous studies have reported that the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) produces a high frequency of within-normal-limits basic scale profiles for adolescents with significant clinical pathology (e.g., Archer, 2005). The current study builds on the observation that the MMPI-A normative sample included participants…

  8. Help-Seeking in a National Sample of Victimized Latino Women: The Influence of Victimization Types

    ERIC Educational Resources Information Center

    Sabina, Chiara; Cuevas, Carlos A.; Schally, Jennifer L.

    2012-01-01

    The current study aimed to examine formal and informal help-seeking responses to interpersonal victimization among a national sample of Latino women. In addition, an examination of help-seeking by victimization type was undertaken. Data came from the Sexual Assault Among Latinas (SALAS) study that obtained help-seeking rates among a victimized…

  9. School Readiness in Children Living in Non-Parental Care: Impacts of Head Start

    ERIC Educational Resources Information Center

    Lipscomb, Shannon T.; Pratt, Megan E.; Schmitt, Sara A.; Pears, Katherine C.; Kim, Hyoun K.

    2013-01-01

    The current study examines the effects of Head Start on the development of school readiness outcomes for children living in non-parental care. Data were obtained from the Head Start Impact Study, a randomized controlled trial of Head Start conducted with a nationally representative sample of Head Start programs and families. The sample included…

  10. Work Participation and Academic Performance: A Test of Alternative Propositions

    ERIC Educational Resources Information Center

    Bradley, Graham

    2006-01-01

    Increasing numbers of full-time university students mix their studies with paid employment. The current research examined the nature, extent and correlates of paid work amongst a sample of 246 university students. Approximately 85% of the sample reported having a paid job during semester, a figure that exceeds that found in previous studies. Five…

  11. The Level of High-Order Thinking and Its Relation to Quality of Life among Students at Ajloun University College

    ERIC Educational Resources Information Center

    Al Rabadi, Wail Minwer; Salem, Rifqa Khleif

    2018-01-01

    The study was designed to identify the effect of high-order thinking on the quality of life among Ajloun University students. The study used the associative method. The randomly selected sample consisted of 147 students from Ajloun University College. The study used two tools: The two measures were applied to the sample of the current study after…

  12. Factors Influence the Digital Media Teaching of Primary School Teachers in a Flipped Class: A Taiwan Case Study

    ERIC Educational Resources Information Center

    Cheng, Yung-Hsun; Weng, Chia-Wen

    2017-01-01

    The current study focuses on the key roles that affect the success of a flipped classroom. The research was conducted with a questionnaire survey created from a study of literature review. Out of a total of 441 samples, 424 valid samples (96.14%) from teachers have been received. The study key conclusions are as follows: (1) a principal leadership…

  13. METHOD DEVELOPMENT FOR THE DETERMINATION OF FORMALDEHYDE IN SAMPLES OF ENVIRONMENTAL ORIGIN

    EPA Science Inventory

    An analytical method was developed for the determination of formaldehyde in samples of environmental origin. After a review of the current literature, five candidate methods involving chemical derivatization were chosen for evaluation. The five derivatization reagents studied wer...

  14. Forest resource inventory assessment in Gunung Rara Forest Reserve, Sabah, using stratified field sampling

    Treesearch

    Kamaruzaman Jusoff

    2000-01-01

    The objective of this paper is to assess the current timber volume by stratified sampling on a proposed plantation area. The study area is located in Gunung Rara Forest Reserve in the district of Tawau, Sabah, Malaysia.

  15. The Effects of the Activities of Current Textbook and 5 E Model on the Attitude of the Students: Sample of "The Global Effects of Natural Resources Unit"

    ERIC Educational Resources Information Center

    Uzunoz, Abdulkadir

    2011-01-01

    This study aimed to determine the effects of the activities of current textbook and 5 E Model on the attitude of the students. This study is a research as an experimental model. For testing the effects of geography education supported by 5 E model and geography education based on activities of current textbook attitude of students, controlled…

  16. Teachers' Opinions about Professional Development Schools=Ögretmenlerin Mesleki Gelisim Okullarina Iliskin Görüsleri

    ERIC Educational Resources Information Center

    Ulubey, Özgür; Yildirim, Kasim; Alpaslan, Muhammet Mustafa; Aykaç, Necdet

    2017-01-01

    The purpose of the current study is to determine teachers' opinions about professional development schools. In the current study; one of the mixed methods, the convergent design was employed. The sampling of the quantitative dimension of the study is comprised of 256 teachers working in 21 elementary and secondary schools in the city of Mugla. The…

  17. Discreet passive explosive detection through 2-sided waveguided fluorescence

    DOEpatents

    Harper, Ross James [Stillwater, OK; la Grone, Marcus [Cushing, OK; Fisher, Mark [Stillwater, OK

    2011-10-18

    The current invention provides a passive sampling device suitable for collecting and detecting the presence of target analytes. In particular, the passive sampling device is suitable for detecting nitro-aromatic compounds. The current invention further provides a passive sampling device reader suitable for determining the collection of target analytes. Additionally, the current invention provides methods for detecting target analytes using the passive sampling device and the passive sampling device reader.

  18. OXYGEN DISSOCIATION OF WHOLE BLOOD STUDIED POLAROGRAPHICALLY

    PubMed Central

    Markus, Gabor; Baumberger, J. Percy

    1952-01-01

    The polarographic current of whole blood is in excess of that given by plasma at the same oxygen tension. The magnitude of this difference depends on (a) the oxygen content of the sample and thus is determined by the red blood cell content and by the state of oxygen saturation of hemoglobin, and (b) on the rate of dissociation of oxyhemoglobin and therefore is influenced by changes in pH, pCO2, and temperature. The total current at 37°C. is proportional to the oxygen content of the sample and can be used to determine the latter. The theoretical basis of the studied phenomena is discussed in detail. PMID:13011281

  19. Some thoughts on problems associated with various sampling media used for environmental monitoring

    USGS Publications Warehouse

    Horowitz, A.J.

    1997-01-01

    Modern analytical instrumentation is capable of measuring a variety of trace elements at concentrations down into the single or double digit parts-per-trillion (ng l-1) range. This holds for the three most common sample media currently used in environmental monitoring programs: filtered water, whole-water and separated suspended sediment. Unfortunately, current analytical capabilities have exceeded the current capacity to collect both uncontaminated and representative environmental samples. The success of any trace element monitoring program requires that this issue be both understood and addressed. The environmental monitoring of trace elements requires the collection of calendar- and event-based dissolved and suspended sediment samples. There are unique problems associated with the collection and chemical analyses of both types of sample media. Over the past 10 years, reported ambient dissolved trace element concentrations have declined. Generally, these decreases do not reflect better water quality, but rather improvements in the procedures used to collect, process, preserve and analyze these samples without contaminating them during these steps. Further, recent studies have shown that the currently accepted operational definition of dissolved constituents (material passing a 0.45 ??m membrane filter) is inadequat owing to sampling and processing artifacts. The existence of these artifacts raises questions about the generation of accurate, precise and comparable 'dissolved' trace element data. Suspended sediment and associated trace elements can display marked short- and long-term spatial and temporal variability. This implies that spatially representative samples only can be obtained by generating composites using depth- and width-integrated sampling techniques. Additionally, temporal variations have led to the view that the determination of annual trace element fluxes may require nearly constant (e.g., high-frequency) sampling and subsequent chemical analyses. Ultimately, sampling frequency for flux estimates becomes dependent on the time period of concern (daily, weekly, monthly, yearly) and the amount of acceptable error associated with these estimates.

  20. The Psychological Effects of Unemployment and Unsatisfactory Employment on Young Adults: Findings from a 10-Year Longitudinal Study.

    PubMed

    Winefield, Anthony H; Delfabbro, Paul H; Winefield, Helen R; Duong, David; Malvaso, Catia

    2017-01-01

    The purpose of the present study was to extend the external validity of an earlier longitudinal study of school leavers by including participants from a representative sample of secondary schools. Questionnaires were administered annually to a sample of South Australian school leavers over a 10-year period. At Time 1 participants were in the last compulsory year of high school aged around 15 years and at Time 10 they were aged around 25 years. Results confirmed those from an earlier longitudinal study showing that the transition from school to satisfactory employment was associated with significant improvements in psychological well-being, whereas transition from school to unemployment or unsatisfactory employment showed no change in psychological well-being. The current findings extended the external validity of the earlier study because whereas participants in the earlier study were sampled from co-educational metropolitan public high schools, the current study included participants from every kind of high school: single sex as well as co-educational, rural as well as metropolitan, and private as well as public.

  1. Apparatus and method for critical current measurements

    DOEpatents

    Martin, Joe A.; Dye, Robert C.

    1992-01-01

    An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil, is disclosed, together with a process of measuring the critical current of a superconductive material, e.g., a clad superconductive material, by placing a superconductive material into the vicinity of the conductive coil of such an apparatus, cooling the superconductive material to a preselected temperature, passing a low amplitude alternating current through the coil, the alternating current capable of generating a magnetic field sufficient to penetrate, e.g., any cladding, and to induce eddy currents in the superconductive material, passing a steadily increasing current through the superconductive material, the current characterized as having a different frequency than the alternating current, and, monitoring the reactance of the coil with a phase sensitive detector as the current passed through the superconductive material is steadily increased whereby critical current of the superconductive material can be observed as the point whereat a component of impedance deviates.

  2. Ballistic magnetotransport in a suspended two-dimensional electron gas with periodic antidot lattices

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

    Zhdanov, E. Yu., E-mail: zhdanov@isp.nsc.ru; Pogosov, A. G.; Budantsev, M. V.

    2017-01-15

    The magnetoresistance of suspended semiconductor nanostructures with a two-dimensional electron gas structured by periodic square antidot lattices is studied. It is shown that the ballistic regime of electron transport is retained after detaching the sample from the substrate. Direct comparative analysis of commensurability oscillations of magnetoresistance and their temperature dependences in samples before and after suspension is performed. It is found that the temperature dependences are almost identical for non-suspended and suspended samples, whereas significant differences are observed in the nonlinear regime, caused by direct current passage. Commensurability oscillations in the suspended samples are more stable with respect to exposuremore » to direct current, which can be presumably explained by electron–electron interaction enhancement after detaching nanostructures from the high-permittivity substrate.« less

  3. The holy grail of soil metal contamination site assessment: reducing risk and increasing confidence of decision making using infield portable X-ray Fluorescence (pXRF) technology

    NASA Astrophysics Data System (ADS)

    Rouillon, M.; Taylor, M. P.; Dong, C.

    2016-12-01

    This research assesses the advantages of integrating field portable X-ray Fluorescence (pXRF) technology for reducing the risk and increase confidence of decision making for metal-contaminated site assessments. Metal-contaminated sites are often highly heterogeneous and require a high sampling density to accurately characterize the distribution and concentration of contaminants. The current regulatory assessment approaches rely on a small number of samples processed using standard wet-chemistry methods. In New South Wales (NSW), Australia, the current notification trigger for characterizing metal-contaminated sites require the upper 95% confidence interval of the site mean to equal or exceed the relevant guidelines. The method's low `minimum' sampling requirements can misclassify sites due to the heterogeneous nature of soil contamination, leading to inaccurate decision making. To address this issue, we propose integrating infield pXRF analysis with the established sampling method to overcome sampling limitations. This approach increases the minimum sampling resolution and reduces the 95% CI of the site mean. Infield pXRF analysis at contamination hotspots enhances sample resolution efficiently and without the need to return to the site. In this study, the current and proposed pXRF site assessment methods are compared at five heterogeneous metal-contaminated sites by analysing the spatial distribution of contaminants, 95% confidence intervals of site means, and the sampling and analysis uncertainty associated with each method. Finally, an analysis of costs associated with both the current and proposed methods is presented to demonstrate the advantages of incorporating pXRF into metal-contaminated site assessments. The data shows that pXRF integrated site assessments allows for faster, cost-efficient, characterisation of metal-contaminated sites with greater confidence for decision making.

  4. Postpartum depression among visible and invisible sexual minority women: a pilot study.

    PubMed

    Flanders, Corey E; Gibson, Margaret F; Goldberg, Abbie E; Ross, Lori E

    2016-04-01

    Significant numbers of sexual minority women are choosing to parent. Despite this, there is limited research on postpartum depression (PPD) with sexual minority mothers and less research considering differences within sexual minority women in the experience of PPD. This research examines two questions to address this gap in research: (1) Do experiences of PPD symptoms vary between different subgroups of sexual minority women, and (2) Which recruitment strategies effectively address the challenge of recruiting sexual minority women who are pregnant? Two Canadian studies recruited participants via consecutive or convenience sampling from midwifery clinics and hospital sites. Participants completed prenatal and postnatal measures of PPD symptoms, social support, and perceived discrimination. Considering our first question, we found an interaction effect between past sexual behavior and current partner gender. Women currently partnered with men reported higher scores on the Edinburgh Postpartum Depression Scale when their sexual history included partners of more than one gender, whereas this effect was not found among women who were currently partnered with women or not partnered. Regarding our second question, most sexual minority participants recruited through convenience sampling were partnered with women and identified as lesbian or queer, while most participants recruited through consecutive sampling were partnered with men and identified as bisexual. Women whose sexual histories include more than one gender and are currently partnered with men may be at a higher risk for PPD symptoms. Recruitment method may influence the type of sample recruited for perinatal mental health research among sexual minority women.

  5. Measurement of attitudes toward commercial development of geothermal energy in Federal Region IX. Final report

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

    Not Available

    1981-06-01

    A survey was conducted of ten target study groups and subgroups for Klamath Falls, Oregon, and Susanville, California: local government, current and potential industry at the site, relocators to the site, current and potential financial community, regulators, and current and potential promoters and developers. The results of benchmark attitudinal measurement is presented separately for each target group. A literature review was conducted and Macro-environmental attitudes of a sample of local government and industry personnel at the sites were assessed. An assessment of capabilities was made which involved two measurements. The first was a measurement of a sample of promoters, developers,more » and industrial service companies active at the site to determine infrastructure capabilities required by industry for geothermal plants. The second measurement involved analyzing a sample of industry management in the area and defining their requirements for plant retrofit and expansion. Finally, the processes used by the study group to analyze information to reach commitment and regulatory decisions that significantly impact on geothermal energy projects at the site were identified and defined.« less

  6. Current Issues in Research on Intelligence. ERIC/AE Digest.

    ERIC Educational Resources Information Center

    Yekovich, Frank R.

    Intelligence has been defined and studied under a number of different rubrics. Three individuals serve as a representative sample of the educational and psychological researchers associated with cognitive psychology who have made significant contributions to current understandings of intelligence. Robert Sternberg's theory contains subcategories…

  7. Magneto-acousto-electrical tomography: a potential method for imaging current density and electrical impedance.

    PubMed

    Haider, S; Hrbek, A; Xu, Y

    2008-06-01

    Primarily this report outlines our investigation on utilizing magneto-acousto-electrical-tomography (MAET) to image the lead field current density in volume conductors. A lead field current density distribution is obtained when a current/voltage source is applied to a sample via a pair of electrodes. This is the first time a high-spatial-resolution image of current density is presented using MAET. We also compare an experimental image of current density in a sample with its corresponding numerical simulation. To image the lead field current density, rather than applying a current/voltage source directly to the sample, we place the sample in a static magnetic field and focus an ultrasonic pulse on the sample to simulate a point-like current dipole source at the focal point. Then by using electrodes we measure the voltage/current signal which, based on the reciprocity theorem, is proportional to a component of the lead field current density. In the theory section, we derive the equation relating the measured voltage to the lead field current density and the displacement velocity caused by ultrasound. The experimental data include the MAET signal and an image of the lead field current density for a thin sample. In addition, we discuss the potential improvements for MAET especially to overcome the limitation created by the observation that no signal was detected from the interior of a region having a uniform conductivity. As an auxiliary we offer a mathematical formula whereby the lead field current density may be utilized to reconstruct the distribution of the electrical impedance in a piecewise smooth object.

  8. Discreet passive explosive detection through 2-sided wave guided fluorescence

    DOEpatents

    Harper, Ross James; la Grone, Marcus; Fisher, Mark

    2012-10-16

    The current invention provides a passive sampling device suitable for collecting and detecting the presence of target analytes. In particular, the passive sampling device is suitable for detecting nitro-aromatic compounds. The current invention further provides a passive sampling device reader suitable for determining the collection of target analytes. Additionally, the current invention provides methods for detecting target analytes using the passive sampling device and the passive sampling device reader.

  9. A new technique for Auger analysis of surface species subject to electron-induced desorption.

    NASA Technical Reports Server (NTRS)

    Pepper, S. V.

    1973-01-01

    A method is presented to observe surface species subject to electron-induced desorption by Auger electron spectroscopy. The surface to be examined is moved under the electron beam at constant velocity, establishing a time-independent condition and eliminating the time response of the electron spectrometer as a limiting factor. The dependence of the Auger signal on the sample velocity, incident electron current, beam diameter, and desorption cross section is analyzed. It is shown that it is advantageous to analyze the moving sample with a high beam current, in contrast to the usual practice of using a low beam current to minimize desorption from a stationary sample. The method is illustrated by the analysis of a friction transfer film of PTFE, in which the fluorine is removed by electron-induced desorption. The method is relevant to surface studies in the field of lubrication and catalysis.

  10. An Aspect of the Capability for Suicide—Fearlessness of the Pain Involved in Dying—Amplifies the Association between Suicide Ideation and Attempts

    PubMed Central

    Smith, Phillip N.; Stanley, Ian H.; Joiner, Thomas E.; Sachs-Ericsson, Natalie J.; Van Orden, Kimberly A.

    2016-01-01

    The interpersonal theory of suicide posits that individuals who experience suicide ideation will only develop suicidal intent, and subsequently engage in suicidal behavior when they have concomitant fearlessness about death and tolerance for physical pain (i.e., the capability for suicide). Objective: The current studies examined the hypothesis that one aspect of the capability for suicide—fearlessness of the pain involved in dying—would amplify the positive association between current suicide ideation and a previous suicide attempt in two samples at high risk for experiencing suicide ideation and suicide attempts. Methods: Study 1 examined this relation using self-report methods in a sample of adults entering treatment in a mental health outpatient clinic. Study 2 utilized similar methods in a sample of adults admitted to inpatient psychiatry. Results: Both studies indicated that those individuals who reported suicide ideation were more likely than non-ideators to report having attempted suicide only if they also reported greater fearlessness of the pain involved in dying. Conclusions: The current findings support the theorized role of the capability for suicide in the transition from ideation to attempt and also support assessing the capability for suicide in risk assessment. PMID:26984289

  11. Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Krieger, K.; Sieglin, B.; Balden, M.; Coenen, J. W.; Göths, B.; Laggner, F.; de Marne, P.; Matthews, G. F.; Nille, D.; Rohde, V.; Dejarnac, R.; Faitsch, M.; Giannone, L.; Herrmann, A.; Horacek, J.; Komm, M.; Pitts, R. A.; Ratynskaia, S.; Thoren, E.; Tolias, P.; ASDEX-Upgrade Team; EUROfusion MST1 Team

    2017-12-01

    Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in the tokamak experiment ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the Divertor Manipulator II system. The exposed sample was designed with an elevated sloped surface inclined against the incident magnetic field to increase the projected parallel power flux to a level were transient melting by ELMs would occur. Sample exposure was controlled by moving the outer strike point to the sample location. As extension to previous melt studies in the new experiment both the current flow from the sample to vessel potential and the local surface temperature were measured with sufficient time resolution to resolve individual ELMs. The experiment provided for the first time a direct link of current flow and surface temperature during transient ELM events. This allows to further constrain the MEMOS melt motion code predictions and to improve the validation of its underlying model assumptions. Post exposure ex situ analysis of the retrieved samples confirms the decreased melt motion observed at shallower magnetic field line to surface angles compared to that at leading edges exposed to the parallel power flux.

  12. Demagnetizing fields of crystallites and a method for measuring the thermodynamic fields of quasi-single-crystal and polycrystalline thin YBa{sub 2}Cu{sub 3}O{sub 7-x} disks

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

    Rostami, Kh. R.

    The role of the demagnetizing fields of crystallites in HTSC samples is studied. An increase in the crystallite size is shown to suppress the intra-and intercrystalline critical currents of the sample in lower fields. The demagnetizing fields of crystallites are shown to be one of the main causes of the fact that the Bean model is invalid for HTSC samples. A method is proposed to measure the thermodynamic field of a superconductor; this method allows the first thermodynamic critical magnetic fields of the sample and its crystallites and 'subcrystallites' to be measured with a high accuracy. The first thermodynamic criticalmore » magnetic fields are used to estimate the critical current density J{sub c} of the sample, crystallites, and subcrystallites.« less

  13. Cathodoluminescence Study of Hafnium Oxide

    NASA Astrophysics Data System (ADS)

    Purcell, Emily; Hengehold, Robert; McClory, John

    2011-10-01

    Hafnium dioxide (HfO2) is increasingly being used in place of silicon oxide as a gate insulator in field effect transistors. This is primarily due to its high dielectric constant, κ, of 25. Samples of HfO2 were grown by either atomic layer deposition (ALD) or pulsed laser deposition (PLD), with the PLD samples having assorted substrate temperatures during deposition (300 C, 500 C, and 750 C). Cathodoluminescence (CL) was chosen as the technique used for studying these HfO2 samples. The CL system used was capable of beam energies ranging from 1 keV to 20 keV and beam currents ranging from 10 μA to 50 μA. A Monte Carlo calculation using CASINO software was performed in order to determine the beam energy for the desired depth of penetration. Measurements were taken at sample temperatures ranging from 7K (closed cycled cryostat) to 300K (room temperature), as well as at various beam energies and beam currents. Comparison will be made between the PLD and ALD spectra.

  14. Current density imaging sequence for monitoring current distribution during delivery of electric pulses in irreversible electroporation.

    PubMed

    Serša, Igor; Kranjc, Matej; Miklavčič, Damijan

    2015-01-01

    Electroporation is gaining its importance in everyday clinical practice of cancer treatment. For its success it is extremely important that coverage of the target tissue, i.e. treated tumor, with electric field is within the specified range. Therefore, an efficient tool for the electric field monitoring in the tumor during delivery of electroporation pulses is needed. The electric field can be reconstructed by the magnetic resonance electric impedance tomography method from current density distribution data. In this study, the use of current density imaging with MRI for monitoring current density distribution during delivery of irreversible electroporation pulses was demonstrated. Using a modified single-shot RARE sequence, where four 3000 V and 100 μs long pulses were included at the start, current distribution between a pair of electrodes inserted in a liver tissue sample was imaged. Two repetitions of the sequence with phases of refocusing radiofrequency pulses 90° apart were needed to acquire one current density image. For each sample in total 45 current density images were acquired to follow a standard protocol for irreversible electroporation where 90 electric pulses are delivered at 1 Hz. Acquired current density images showed that the current density in the middle of the sample increased from first to last electric pulses by 60%, i.e. from 8 kA/m2 to 13 kA/m2 and that direction of the current path did not change with repeated electric pulses significantly. The presented single-shot RARE-based current density imaging sequence was used successfully to image current distribution during delivery of short high-voltage electric pulses. The method has a potential to enable monitoring of tumor coverage by electric field during irreversible electroporation tissue ablation.

  15. An experimental system for controlled exposure of biological samples to electrostatic discharges.

    PubMed

    Marjanovič, Igor; Kotnik, Tadej

    2013-12-01

    Electrostatic discharges occur naturally as lightning strokes, and artificially in light sources and in materials processing. When an electrostatic discharge interacts with living matter, the basic physical effects can be accompanied by biophysical and biochemical phenomena, including cell excitation, electroporation, and electrofusion. To study these phenomena, we developed an experimental system that provides easy sample insertion and removal, protection from airborne particles, observability during the experiment, accurate discharge origin positioning, discharge delivery into the sample either through an electric arc with adjustable air gap width or through direct contact, and reliable electrical insulation where required. We tested the system by assessing irreversible electroporation of Escherichia coli bacteria (15 mm discharge arc, 100 A peak current, 0.1 μs zero-to-peak time, 0.2 μs peak-to-halving time), and gene electrotransfer into CHO cells (7 mm discharge arc, 14 A peak current, 0.5 μs zero-to-peak time, 1.0 μs peak-to-halving time). Exposures to natural lightning stroke can also be studied with this system, as due to radial current dissipation, the conditions achieved by a stroke at a particular distance from its entry are also achieved by an artificial discharge with electric current downscaled in magnitude, but similar in time course, correspondingly closer to its entry. © 2013.

  16. Development of new demi-span equations from a nationally representative sample of adults to estimate maximal adult height.

    PubMed

    Hirani, Vasant; Tabassum, Faiza; Aresu, Maria; Mindell, Jennifer

    2010-08-01

    Various measures have been used to estimate height when assessing nutritional status. Current equations to obtain demi-span equivalent height (DEH(Bassey)) are based on a small sample from a single study. The objectives of this study were to develop more robust DEH equations from a large number of men (n = 591) and women (n = 830) aged 25-45 y from a nationally representative cross-sectional sample (Health Survey for England 2007). Sex-specific regression equations were produced from young adults' (aged 25-45 y) measured height and demi-span to estimate new DEH equations (DEH(new)). DEH in people aged >or= 65 y was calculated using DEH(new). DEH(new) estimated current height in people aged 25-45 y with a mean difference of 0.04 in men (P = 0.80) and -0.29 in women (P = 0.05). Height, demi-span, DEH(new), and DEH(Bassey) declined by age group in both sexes aged >or=65 y (P < 0.05); DEH were larger than the measured height for all age groups (mean difference between DEH(new) and current height was -2.64 in men and -3.16 in women; both P < 0.001). Comparisons of DEH estimates showed good agreement, but DEH(new) was significantly higher than DEH(Bassey) in each age and sex group in older people. The new equations that are based on a large, randomly selected, nationally representative sample of young adults are more robust for predicting current height in young adults when height measurements are unavailable and can be used in the future to predict maximal adult height more accurately in currently young adults as they age.

  17. Molecular epidemiology of rabies viruses circulating in two rabies endemic provinces of Laos, 2011-2012: regional diversity in Southeast Asia.

    PubMed

    Ahmed, Kamruddin; Phommachanh, Phouvong; Vorachith, Phengphet; Matsumoto, Takashi; Lamaningao, Pheophet; Mori, Daisuke; Takaki, Minako; Douangngeun, Bounlom; Khambounheuang, Bounkhouang; Nishizono, Akira

    2015-03-01

    Although rabies is endemic in Laos, genetic characterization of the viruses in this country is limited. There are growing concerns that development in the region may have increased transport of dog through Laos for regional dog meat consumption, and that this may cause spillover of the viruses from dogs brought here from other countries. This study was therefore undertaken to evaluate the current rabies situation and the genetic characteristics of rabies viruses currently circulating in Laos. We determined the rate of rabies-positive samples by analyzing data from animal samples submitted to the Lao Ministry of Agriculture and Forestry's National Animal Health Centre rabies laboratory from 2004 through 2011. Twenty-three rabies-positive samples were used for viral genetic characterization. Full genome sequencing was performed on two rabies viruses. Rabies-positive samples increased substantially from 40.5% in 2004 to 60.2% in 2009 and continued at this level during the study period. More than 99% of the samples were from dogs, followed by cats and monkeys. Phylogenetic analyses showed that three rabies virus lineages belonging to the Southeast Asian cluster are currently circulating in Laos; these are closely related to viruses from Thailand, Cambodia and Vietnam. Lineages of the circulating Laos rabies viruses diverged from common ancestors as recently as 44.2 years and as much as 55.3 years ago, indicating periodic virus invasions. There is an increasing trend of rabies in Laotian animals. Similar to other rabies-endemic countries, dogs are the main viral reservoir. Three viral lineages closely related to viruses from neighboring countries are currently circulating in Laos. Data provide evidence of periodic historic exchanges of the viruses with neighboring countries, but no recent invasion.

  18. Molecular Epidemiology of Rabies Viruses Circulating in Two Rabies Endemic Provinces of Laos, 2011–2012: Regional Diversity in Southeast Asia

    PubMed Central

    Ahmed, Kamruddin; Phommachanh, Phouvong; Vorachith, Phengphet; Matsumoto, Takashi; Lamaningao, Pheophet; Mori, Daisuke; Takaki, Minako; Douangngeun, Bounlom; Khambounheuang, Bounkhouang; Nishizono, Akira

    2015-01-01

    Background Although rabies is endemic in Laos, genetic characterization of the viruses in this country is limited. There are growing concerns that development in the region may have increased transport of dog through Laos for regional dog meat consumption, and that this may cause spillover of the viruses from dogs brought here from other countries. This study was therefore undertaken to evaluate the current rabies situation and the genetic characteristics of rabies viruses currently circulating in Laos. Methods We determined the rate of rabies-positive samples by analyzing data from animal samples submitted to the Lao Ministry of Agriculture and Forestry’s National Animal Health Centre rabies laboratory from 2004 through 2011. Twenty-three rabies-positive samples were used for viral genetic characterization. Full genome sequencing was performed on two rabies viruses. Results Rabies-positive samples increased substantially from 40.5% in 2004 to 60.2% in 2009 and continued at this level during the study period. More than 99% of the samples were from dogs, followed by cats and monkeys. Phylogenetic analyses showed that three rabies virus lineages belonging to the Southeast Asian cluster are currently circulating in Laos; these are closely related to viruses from Thailand, Cambodia and Vietnam. Lineages of the circulating Laos rabies viruses diverged from common ancestors as recently as 44.2 years and as much as 55.3 years ago, indicating periodic virus invasions. Conclusion There is an increasing trend of rabies in Laotian animals. Similar to other rabies-endemic countries, dogs are the main viral reservoir. Three viral lineages closely related to viruses from neighboring countries are currently circulating in Laos. Data provide evidence of periodic historic exchanges of the viruses with neighboring countries, but no recent invasion. PMID:25825907

  19. The Anorexia Nervosa Genetics Initiative: Study description and sample characteristics of the Australian and New Zealand arm.

    PubMed

    Kirk, Katherine M; Martin, Felicity C; Mao, Amy; Parker, Richard; Maguire, Sarah; Thornton, Laura M; Zhu, Gu; McAloney, Kerrie; Freeman, Jeremy L; Hay, Phillipa; Madden, Sloane; Morgan, Christine; Russell, Janice; Sawyer, Susan M; Hughes, Elizabeth K; Fairweather-Schmidt, A Kate; Fursland, Anthea; McCormack, Julie; Wagg, Fiona; Jordan, Jennifer; Kennedy, Martin A; Ward, Warren; Wade, Tracey D; Bulik, Cynthia M; Martin, Nicholas G

    2017-06-01

    Anorexia nervosa is a severe psychiatric disorder with high mortality rates. While its aetiology is poorly understood, there is evidence of a significant genetic component. The Anorexia Nervosa Genetics Initiative is an international collaboration which aims to understand the genetic basis of the disorder. This paper describes the recruitment and characteristics of the Australasian Anorexia Nervosa Genetics Initiative sample, the largest sample of individuals with anorexia nervosa ever assembled across Australia and New Zealand. Participants completed an online questionnaire based on the Structured Clinical Interview Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) eating disorders section. Participants who met specified case criteria for lifetime anorexia nervosa were requested to provide a DNA sample for genetic analysis. Overall, the study recruited 3414 Australians and 543 New Zealanders meeting the lifetime anorexia nervosa case criteria by using a variety of conventional and social media recruitment methods. At the time of questionnaire completion, 28% had a body mass index ⩽ 18.5 kg/m 2 . Fasting and exercise were the most commonly employed methods of weight control, and were associated with the youngest reported ages of onset. At the time of the study, 32% of participants meeting lifetime anorexia nervosa case criteria were under the care of a medical practitioner; those with current body mass index < 18.5 kg/m 2 were more likely to be currently receiving medical care (56%) than those with current body mass index ⩾ 18.5 kg/m 2 (23%). Professional treatment for eating disorders was most likely to have been received from general practitioners (45% of study participants), dietitians (42%) and outpatient programmes (42%). This study was effective in assembling the largest community sample of people with lifetime anorexia nervosa in Australia and New Zealand to date. The proportion of people with anorexia nervosa currently receiving medical care, and the most common sources of treatment accessed, indicates the importance of training for general practitioners and dietitians in treating anorexia nervosa.

  20. Ir-based refractory superalloys by pulse electric current sintering (PECS) process (II prealloyed powder)

    NASA Astrophysics Data System (ADS)

    Huang, C.; Yamabe-Mitarai, Y.; Harada, H.

    2002-02-01

    Five prealloyed powder samples prepared from binary Ir-based refractory superalloys were sintered at 1800 °C for 4 h by Pulse Electric Current Sintering (PECS). No metal loss was observed during sintering. The relative densities of the sintered specimens all exceeded 90% T.D. The best one was Ir-13% Hf with the density of 97.82% T.D. Phases detected in sintered samples were in accordance with the phase diagram as expected. Fractured surfaces were observed in two samples (Ir-13% Hf and Ir-15% Zr). Some improvements obtained by using prealloyed powders instead of elemental powders, which were investigated in the previous studies, were presented.

  1. Use of Non-invasive Uterine Electromyography in the Diagnosis of Preterm Labour

    PubMed Central

    Lucovnik, M.; Novak-Antolic, Z.; Garfield, R.E.

    2012-01-01

    Predictive values of methods currently used in the clinics to diagnose preterm labour are low. This leads to missed opportunities to improve neonatal outcomes and, on the other hand, to unnecessary hospitalizations and treatments. In addition, research of new and potentially more effective preterm labour treatments is hindered by the inability to include only patients in true preterm labour into studies. Uterine electromyography (EMG) detects changes in cell excitability and coupling required for labour and has higher predictive values for preterm delivery than currently available methods. This methodology could also provide a better means to evaluate various therapeutic interventions for preterm labour. Our manuscript presents a review of uterine EMG studies examining the potential clinical value that this technology possesses over what is available to physicians currently. We also evaluated the impact that uterine EMG could have on investigation of preterm labour treatments by calculating sample sizes for studies using EMG vs. current methods to enrol women. Besides helping clinicians to make safer and more cost-effective decisions when managing patients with preterm contractions, implementation of uterine EMG for diagnosis of preterm labour would also greatly reduce sample sizes required for studies of treatments. PMID:24753891

  2. Herbicides and their transformation products in source-water aquifers tapped by public-supply wells in Illinois, 2001-02

    USGS Publications Warehouse

    Mills, Patrick C.; McMillan, William D.

    2004-01-01

    During 2001-02, ground-water samples were collected from 117 public-supply wells distributed throughout Illinois to evaluate the occurrence of herbicides and their transformation products in the State?s source-water aquifers. Wells were selected using a stratified-random method to ensure representation of the major types of source-water aquifers in the State. Samples were analyzed for 18 herbicides and 18 transformation products, including 3 triazine and 14 chloroacetanilide products. Herbicide compounds (field-applied parent herbicides and their transformation products) were detected in 34 percent of samples. A subset of samples was collected unfiltered to determine if analytical results for herbicides in unfiltered samples are similar to those in paired filtered samples and, thus, can be considered equally representative of herbicide concentrations in ground water supplied to the public. The study by the U.S. Geological Survey was done in cooperation with the Illinois Environmental Protection Agency. Parent herbicides were detected in only 4 percent of all samples. The six most frequently detected herbicide compounds (from 5 to 28 percent of samples) were chloroacetanilide transformation products. The frequent occurrence of transformation products and their higher concentrations relative to those of most parent herbicides confirm the importance of obtaining information on transformation products to understand the mobility and fate of herbicides in ground-water systems. No sample concentrations determined during this study exceeded current (2003) Federal or State drinking-water standards; however, standards are established for only seven parent herbicides. Factors related to the occurrence of herbicide compounds in the State?s source-water aquifers include unconsolidated and unconfined conditions, various hydrogeologic characteristics and well-construction aspects at shallow depths, and proximity to streams. Generally, the closer an aquifer (or well location) is to a recharge area and (or) the stronger the hydraulic connection between an aquifer and a recharge area, the younger the ground water and the more vulnerable the aquifer will be to contamination by herbicide compounds. The weak relation between current (2001) statewide application rates of herbicides and current (2001-02) occurrence of herbicide compounds in source-water aquifers indicates that additional factors must be considered when relating herbicide-application rates to occurrence. These factors include historical application rates and the mobility and persistence of the various herbicide compounds in ground-water systems. Frequency of detection and concentrations of herbicides compounds in the State?s source-water aquifers are indicated to be highest during the spring, when crops are planted and herbicides primarily are applied. Excess nitrate (concentrations of nitrate, as nitrogen, higher than 3 milligrams per liter) in ground water strongly indicates the co-occurrence of herbicide compounds. However, nitrate concentrations are not a reliable indicator of herbicide-compound concentrations. The inverse relation found between current use of land for corn and soybean production and current occurrence of herbicide compounds in underlying aquifers indicates that various factors, along with current agricultural land use, contribute to herbicide occurrence. These factors include, among others, land-use history, ground-water age, ground-water-flow patterns, geology, soil microbiology, and chemistry and persistence of the herbicide compounds. Detection of agriculture-specific herbicide compounds in 71 percent of samples from urban areas with no current or recent agricultural land use near the sampled wells indicates that recharge to certain high-capacity supply wells may originate at considerable distances (up to about 10 miles) from the wells. Essentially no difference was found between the analytical results for herbicides in paired unfiltered and filtered samples,

  3. Challenges to Successful Total Quality Management Implementation in Public Secondary Schools: A Case Study of Kohat District, Pakistan

    ERIC Educational Resources Information Center

    Suleman, Qaiser; Gul, Rizwana

    2015-01-01

    The current study explores the challenges faced by public secondary schools in successful implementation of total quality management (TQM) in Kohat District. A sample of 25 heads and 75 secondary school teachers selected from 25 public secondary schools through simple random sampling technique was used. Descriptive research designed was used and a…

  4. Risk Factors for Running Away among a General Population Sample of Males and Females

    ERIC Educational Resources Information Center

    Tyler, Kimberly A.; Hagewen, Kellie J.; Melander, Lisa A.

    2011-01-01

    The present study examines risk factors for running away and homelessness among a sample of more than 7,000 currently housed youth using the National Longitudinal Study of Adolescent Health (Add Health). Structural equation modeling results revealed that those with greater levels of family instability and those who ran away at Wave 2 were…

  5. Attitudes Towards Seeking Psychological Help among a Sample of Turkish University Students: The Roles of Rumination and Internal Working Models

    ERIC Educational Resources Information Center

    Turan, Numan; Erdur-Baker, Özgür

    2014-01-01

    The current study investigates how attitudes towards seeking psychological help relate to internal working models of attachment (self-model and other-model) and ruminative tendencies. The study includes 589 Turkish university students (278 females, 308 males and 3 unknown) by implementing a convenient sampling procedure. The average age of the…

  6. Romanian, Spanish and US Secondary Science Teacher Perceptions of Threats to the Biosphere

    ERIC Educational Resources Information Center

    Robinson, Michael; Naumescu, Adrienne Kozan; Ives, Bob

    2009-01-01

    This paper presents the data from a current study involving 41 Romanian secondary science teachers and a previously published study that compared 89 Spanish and 42 US secondary science teachers. All three groups were convenience samples who answered a two part questionnaire that was given in English, Spanish or Romanian, depending on the sample.…

  7. Changes in the Values and Life-Style Preferences of University Students.

    ERIC Educational Resources Information Center

    Thompson, Kenrick S.

    Results are reported of a survey to determine whether values and life-style preferences of university students have significantly changed during the last 25-30 years. The current study, which consists of a sample of over 1,000 students, is compared with a study conducted by Charles Morris in 1945-53. The Morris sample consisted of over 2,500…

  8. Organic Contamination Baseline Study in NASA Johnson Space Center Astromaterials Curation Laboratories

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Allen, Carlton C.; Allton, Judith H.

    2014-01-01

    Future robotic and human spaceflight missions to the Moon, Mars, asteroids, and comets will require curating astromaterial samples with minimal inorganic and organic contamination to preserve the scientific integrity of each sample. 21st century sample return missions will focus on strict protocols for reducing organic contamination that have not been seen since the Apollo manned lunar landing program. To properly curate these materials, the Astromaterials Acquisition and Curation Office under the Astromaterial Research and Exploration Science Directorate at NASA Johnson Space Center houses and protects all extraterrestrial materials brought back to Earth that are controlled by the United States government. During fiscal year 2012, we conducted a year-long project to compile historical documentation and laboratory tests involving organic investigations at these facilities. In addition, we developed a plan to determine the current state of organic cleanliness in curation laboratories housing astromaterials. This was accomplished by focusing on current procedures and protocols for cleaning, sample handling, and storage. While the intention of this report is to give a comprehensive overview of the current state of organic cleanliness in JSC curation laboratories, it also provides a baseline for determining whether our cleaning procedures and sample handling protocols need to be adapted and/or augmented to meet the new requirements for future human spaceflight and robotic sample return missions.

  9. MgB2 wire diameter reduction by hot isostatic pressing—a route for enhanced critical current density

    NASA Astrophysics Data System (ADS)

    Morawski, A.; Cetner, T.; Gajda, D.; Zaleski, A. J.; Häßler, W.; Nenkov, K.; Rindfleisch, M. A.; Tomsic, M.; Przysłupski, P.

    2018-07-01

    The effect of wire diameter reduction on the critical current density of pristine MgB2 wire was studied. Wires were treated by a hot isostatic pressing method at 570 °C and at pressures of up to 1.1 GPa. It was found that the wire diameter reduction induces an increase of up to 70% in the mass density of the superconducting cores. This feature leads to increases in critical current, critical current density, and pinning force density. The magnitude and field dependence of the critical current density are related to both grain connectivity and structural defects, which act as effective pinning centers. High field transport properties were obtained without doping of the MgB2 phase. A critical current density jc of 3500 A mm‑2 was reached at 4 K, 6 T for the best sample, which was a five-fold increase compared to MgB2 samples synthesized at ambient pressure.

  10. Effects of pipette modulation and imaging distances on ion currents measured with scanning ion conductance microscopy (SICM).

    PubMed

    Chen, Chiao-Chen; Baker, Lane A

    2011-01-07

    Local conductance variations can be estimated by measuring ion current magnitudes with scanning ion conductance microscopy (SICM). Factors which influence image quality and quantitation of ion currents measured with SICM have been evaluated. Specifically, effects of probe-sample separation and pipette modulation have been systematically studied for the case of imaging conductance variations at pores in a polymer membrane under transmembrane concentration gradients. The influence of probe-sample separation on ion current images was evaluated using distance-modulated (ac) feedback. Approach curves obtained using non-modulated (dc) feedback were also recorded to determine the relative influence of pipette-generated convection by comparison of ion currents measured with both ac and dc feedback modes. To better interpret results obtained, comparison to a model based on a disk-shaped geometry for nanopores in the membrane, as well as relevant position-dependent parameters of the experiment is described. These results advance our current understanding of conductance measurements with SICM.

  11. Preliminary assessment of pavement damage due to heavier loads on Louisiana highways.

    DOT National Transportation Integrated Search

    1999-05-01

    The current study makes a preliminary assessment of the impact of increasing the gross vehicle weight (GVW) from current legal limits to 100,000 lb (45,360 kg) on vehicles hauling sugarcane, rice, timber, and cotton. Sample sections of road in each a...

  12. Teaching Math Online: Current Practices in Turkey

    ERIC Educational Resources Information Center

    Akdemir, Omur

    2011-01-01

    Changing nature of student population, developments in technology, and insufficient number of traditional universities have made online courses popular around the globe. This study was designed to investigate the current practices of teaching mathematics online in Turkish Universities through a qualitative inquiry. The snowball sampling method was…

  13. A standardized method for sampling and extraction methods for quantifying microplastics in beach sand.

    PubMed

    Besley, Aiken; Vijver, Martina G; Behrens, Paul; Bosker, Thijs

    2017-01-15

    Microplastics are ubiquitous in the environment, are frequently ingested by organisms, and may potentially cause harm. A range of studies have found significant levels of microplastics in beach sand. However, there is a considerable amount of methodological variability among these studies. Methodological variation currently limits comparisons as there is no standard procedure for sampling or extraction of microplastics. We identify key sampling and extraction procedures across the literature through a detailed review. We find that sampling depth, sampling location, number of repeat extractions, and settling times are the critical parameters of variation. Next, using a case-study we determine whether and to what extent these differences impact study outcomes. By investigating the common practices identified in the literature with the case-study, we provide a standard operating procedure for sampling and extracting microplastics from beach sand. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The family assessment device: an update.

    PubMed

    Mansfield, Abigail K; Keitner, Gabor I; Dealy, Jennifer

    2015-03-01

    The current study set out to describe family functioning scores of a contemporary community sample, using the Family Assessment Device (FAD), and to compare this to a currently help-seeking sample. The community sample consisted of 151 families who completed the FAD. The help-seeking sample consisted of 46 families who completed the FAD at their first family therapy appointment as part of their standard care at an outpatient family therapy clinic at an urban hospital. Findings suggest that FAD means from the contemporary community sample indicate satisfaction with family functioning, while FAD scores from the help-seeking sample indicate dissatisfaction with family functioning. In addition, the General Functioning scale of the FAD continues to correlate highly with all other FAD scales, except Behavior Control. The cut-off scores for the FAD indicating satisfaction or dissatisfaction by family members with their family functioning continue to be relevant and the FAD continues to be a useful tool to assess family functioning in both clinical and research contexts. © 2014 Family Process Institute.

  15. Depression, anxiety, and stress in partners of Australian combat veterans and military personnel: a comparison with Australian population norms.

    PubMed

    MacDonell, Gail V; Bhullar, Navjot; Thorsteinsson, Einar B

    2016-01-01

    Partners of Australian combat veterans are at an increased risk of experiencing mental health problems. The present study provides a comparative analysis of the mental health of partners of veterans with that of the Australian normative data. To compare different types of groups of partners, the study samples comprised: (a) partners of Australian combat veterans (Sample 1: n = 282, age M = 60.79, SD = 5.05), (b) a sub-sample of partners of Australian combat veterans from the previous sample (Sample 2: n = 50; M = 60.06, SD = 4.80), (c) partners of Special Air Services Regiment (SASR) personnel (Sample 3: n = 40, age M = 34.39SD = 7.01), and (d) partners of current serving military (non-SASR) personnel (Sample 4: n = 38, age M = 32.37, SD = 6.20). Respondents completed measures assessing their reported levels of depression, anxiety, and stress. Samples 1 and 2 comprised partners of Australian military veterans who reported significantly greater symptoms of depression, anxiety, and stress than the comparative population norms. The sample of SASR personnel partners (Sample 3) reported significantly lower levels of depression and anxiety, whereas the sample with non-SASR personnel partners (Sample 4) reported a significantly greater stress symptomatology than the comparative norms. Number of deployments was found to be associated with depression, anxiety, and stress in partners of non-SASR veterans (Sample 4). Lessons and protective factors can be learnt from groups within the current military as to what may assist partners and families to maintain a better level of psychosocial health.

  16. Predictability of the California Current System

    NASA Technical Reports Server (NTRS)

    Miller, Arthur J.; Chereskin, T.; Cornuelle, B. D.; Niiler, P. P.; Moisan, J. R.; Lindstrom, Eric (Technical Monitor)

    2001-01-01

    The physical and biological oceanography of the Southern California Bight (SCB), a highly productive subregion of the California Current System (CCS) that extends from Point Conception, California, south to Ensenada, Mexico, continues to be extensively studied. For example, the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program has sampled this region for over 50 years, providing an unparalleled time series of physical and biological data. However, our understanding of what physical processes control the large-scale and mesoscale variations in these properties is incomplete. In particular, the non-synoptic and relatively coarse spatial sampling (70km) of the hydrographic grid does not completely resolve the mesoscale eddy field (Figure 1a). Moreover, these unresolved physical variations exert a dominant influence on the evolution of the ecosystem. In recent years, additional datasets that partially sample the SCB have become available. Acoustic Doppler Current Profiler (ADCP) measurements, which now sample upper-ocean velocity between stations, and sea level observations along TOPEX tracks give a more complete picture of the mesoscale variability. However, both TOPEX and ADCP are well-sampled only along the cruise or orbit tracks and coarsely sampled in time and between tracks. Surface Lagrangian drifters also sample the region, although irregularly in time and space. SeaWiFS provides estimates of upper-ocean chlorophyll-a (chl-alpha), usually giving nearly complete coverage for week-long intervals, depending on cloud coverage. Historical ocean color data from the Coastal Zone Color Scanner (CZCS) has been used extensively to determine phytoplankton patterns and variability, characterize the primary production across the SCB coastal fronts, and describe the seasonal and interannual variability in pigment concentrations. As in CalCOFI, these studies described much of the observed structures and their variability over relatively large space and time scales.

  17. Malaria prevalence metrics in low- and middle-income countries: an assessment of precision in nationally-representative surveys.

    PubMed

    Alegana, Victor A; Wright, Jim; Bosco, Claudio; Okiro, Emelda A; Atkinson, Peter M; Snow, Robert W; Tatem, Andrew J; Noor, Abdisalan M

    2017-11-21

    One pillar to monitoring progress towards the Sustainable Development Goals is the investment in high quality data to strengthen the scientific basis for decision-making. At present, nationally-representative surveys are the main source of data for establishing a scientific evidence base, monitoring, and evaluation of health metrics. However, little is known about the optimal precisions of various population-level health and development indicators that remains unquantified in nationally-representative household surveys. Here, a retrospective analysis of the precision of prevalence from these surveys was conducted. Using malaria indicators, data were assembled in nine sub-Saharan African countries with at least two nationally-representative surveys. A Bayesian statistical model was used to estimate between- and within-cluster variability for fever and malaria prevalence, and insecticide-treated bed nets (ITNs) use in children under the age of 5 years. The intra-class correlation coefficient was estimated along with the optimal sample size for each indicator with associated uncertainty. Results suggest that the estimated sample sizes for the current nationally-representative surveys increases with declining malaria prevalence. Comparison between the actual sample size and the modelled estimate showed a requirement to increase the sample size for parasite prevalence by up to 77.7% (95% Bayesian credible intervals 74.7-79.4) for the 2015 Kenya MIS (estimated sample size of children 0-4 years 7218 [7099-7288]), and 54.1% [50.1-56.5] for the 2014-2015 Rwanda DHS (12,220 [11,950-12,410]). This study highlights the importance of defining indicator-relevant sample sizes to achieve the required precision in the current national surveys. While expanding the current surveys would need additional investment, the study highlights the need for improved approaches to cost effective sampling.

  18. Urine chromium as an estimator of air exposure to stainless steel welding fumes.

    PubMed

    Sjögren, B; Hedström, L; Ulfvarson, U

    1983-01-01

    Welding stainless steel with covered electrodes, also called manual metal arc welding, generates hexavalent airborne chromium. Chromium concentrations in air and post-shift urine samples, collected the same arbitrarily chosen working day, showed a linear relationship. Since post-shift urine samples reflect chromium concentrations of both current and previous stainless steel welding fume exposure, individual urine measurements are suggested as approximate although not exact estimators of current exposure. This study evaluates the practical importance of such measurements by means of confidence limits and tests of validity.

  19. Clinical application of microsampling versus conventional sampling techniques in the quantitative bioanalysis of antibiotics: a systematic review.

    PubMed

    Guerra Valero, Yarmarly C; Wallis, Steven C; Lipman, Jeffrey; Stove, Christophe; Roberts, Jason A; Parker, Suzanne L

    2018-03-01

    Conventional sampling techniques for clinical pharmacokinetic studies often require the removal of large blood volumes from patients. This can result in a physiological or emotional burden, particularly for neonates or pediatric patients. Antibiotic pharmacokinetic studies are typically performed on healthy adults or general ward patients. These may not account for alterations to a patient's pathophysiology and can lead to suboptimal treatment. Microsampling offers an important opportunity for clinical pharmacokinetic studies in vulnerable patient populations, where smaller sample volumes can be collected. This systematic review provides a description of currently available microsampling techniques and an overview of studies reporting the quantitation and validation of antibiotics using microsampling. A comparison of microsampling to conventional sampling in clinical studies is included.

  20. Respondent-Driven Sampling: An Assessment of Current Methodology.

    PubMed

    Gile, Krista J; Handcock, Mark S

    2010-08-01

    Respondent-Driven Sampling (RDS) employs a variant of a link-tracing network sampling strategy to collect data from hard-to-reach populations. By tracing the links in the underlying social network, the process exploits the social structure to expand the sample and reduce its dependence on the initial (convenience) sample.The current estimators of population averages make strong assumptions in order to treat the data as a probability sample. We evaluate three critical sensitivities of the estimators: to bias induced by the initial sample, to uncontrollable features of respondent behavior, and to the without-replacement structure of sampling.Our analysis indicates: (1) that the convenience sample of seeds can induce bias, and the number of sample waves typically used in RDS is likely insufficient for the type of nodal mixing required to obtain the reputed asymptotic unbiasedness; (2) that preferential referral behavior by respondents leads to bias; (3) that when a substantial fraction of the target population is sampled the current estimators can have substantial bias.This paper sounds a cautionary note for the users of RDS. While current RDS methodology is powerful and clever, the favorable statistical properties claimed for the current estimates are shown to be heavily dependent on often unrealistic assumptions. We recommend ways to improve the methodology.

  1. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

    PubMed

    Steimer, Andreas; Schindler, Kaspar

    2015-01-01

    Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational theories about UP states during slow wave sleep and present possible extensions of the model in the context of spike-frequency adaptation.

  2. Pesticide use in the wheat-maize double cropping systems of the North China Plain: Assessment, field study, and implications.

    PubMed

    Brauns, Bentje; Jakobsen, Rasmus; Song, Xianfang; Bjerg, Poul L

    2018-03-01

    In the North China Plain (NCP), rising inputs of pesticides have intensified the environmental impact of farming activities in recent decades by contributing to surface water and groundwater contamination. In response to this, the Chinese government imposed stricter regulations on pesticide approval and application, and better monitoring strategies are being developed. However, sufficient and well-directed research on the accumulation and impact of different pesticides is needed for informed decision-making. In this study, current pesticide use, and recent and current research on water contamination by pesticides in the NCP are reviewed and assessed. Additionally, a small-scale field study was performed to determine if residuals from currently-used pesticides in the NCP can be detected in surface water, and in connected shallow groundwater. The contaminants of interest were commonly used pesticides on winter wheat-summer maize fields (the dominant cropping system in the NCP), such as 2,4-D and atrazine. Sampling took place in May, July, and October 2013; and March 2014. Results from our literature research showed that sampling is biased towards surface water monitoring. Furthermore, most studies focus on organic chlorinated pesticides (OCPs) like the isomers of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), which were banned in China in 1983. However, currently-used herbicides like 2,4-D and atrazine were detected in river water and groundwater in all samplings of our field study. The highest concentrations of 2,4-D and atrazine were found in the river water, ranging up to 3.00 and 0.96μg/L, respectively. The monitoring of banned compounds was found to be important because several studies indicate that they are still accumulating in the environment and/or are still illegally in use. However, supported by our own data, we find that the monitoring in groundwater and surface water of currently permitted pesticides in China needs equal attention, and should therefore be increased. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Free flux flow in two single crystals of V3Si with slightly different pinning strengths

    NASA Astrophysics Data System (ADS)

    Gafarov, O.; Gapud, A. A.; Moraes, S.; Thompson, J. R.; Christen, D. K.; Reyes, A. P.

    2010-10-01

    Results of recent measurements on two very clean, single-crystal samples of the A15 superconductor V3Si are presented. Magnetization and transport data already confirmed the ``clean'' quality of both samples, as manifested by: (i) high residual resistivity ratio, (ii) very low critical current densities, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted in the slightly ``dirtier'' sample, which consequently also has higher critical current density Jc(H). High-current Lorentz forces are applied on mixed-state vortices in order to induce the highly ordered free flux flow (FFF) phase, using the same methods as in previous work. A traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf(H), presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes core size into account, and predict a clear deviation from BS. In this study, ρf(H) is confirmed to be consistent with predictions of KZ, as will be discussed.

  4. Cross-study differences in the etiology of reading comprehension: A meta-analytical review of twin studies

    PubMed Central

    Little, Callie W; Haughbrook, Rasheda; Hart, Sara A

    2016-01-01

    Numerous twin studies have been published examining the genetic and environmental etiology of reading comprehension, though the etiological estimates may be influenced currently unidentified sample conditions (e.g., Tucker-Drob & Bates, 2015). The purpose of the current meta-analysis was to average the etiological influences of reading comprehension and to explore the potential moderators that may be influencing these estimates. Results revealed an average heritability estimate of h2 = .59, with significant variation in estimates across studies, suggesting potential moderation. Heritability was moderated by publication year, grade level, project, zygosity determination method, and response type. The average shared environmental estimate was c2 = .16, with publication year, grade and zygosity determination method acting as significant moderators. These findings support the large role of genetic influences on reading comprehension, and a small but significant role of shared environmental influences. The significant moderators of etiological influences within the current synthesis suggest our interpretation of how genes and environment influence reading comprehension should reflect aspects of study and sample. PMID:27630039

  5. Base Realignment and Closure Environmental Evaluation (BRAC EE) Fort Devens, Massachusetts

    DTIC Science & Technology

    1995-09-01

    Not Sampled ......... 6 2.3.2 Transformer Sites Sampled ........................ 7 2.4 Soil Sampling Protocol and Analytical Program ...Evaluation (AREE) 66. The study included evaluating the current PCB Transformer Management Program administered by the Fort Devens Environmental Management...Office (EMO), the Fort Devens Spill Contingency Plan, and the ongoing transformer inspection program . Personnel in both the Fort Devens EMO and the Fort

  6. The role of perceived parenting in familial aggregation of anxiety disorders in children.

    PubMed

    van Gastel, W; Legerstee, J S; Ferdinand, R F

    2009-01-01

    This study was designed to explore the role of perceived parenting style in the familial aggregation of anxiety disorders. We examined the association between parental and child anxiety diagnoses, and tested whether this association was partly due to a perceived parenting style. The study was conducted in a clinical sample as well as in a control sample. Parental lifetime and current anxiety diagnoses were significantly associated with child anxiety diagnoses. When maternal and paternal lifetime and current anxiety diagnoses were entered as separate predictors, only maternal current anxiety diagnoses appeared to be significant. Perceived parenting style was assessed with the dimensions "overprotection," "emotional warmth," "rejection," and "anxious rearing." Results indicated that only maternal and paternal 'overprotection' was significantly but negatively associated with child anxiety. However, further analyses showed that 'overprotection' did not have a significant mediating role in the familial aggregation of anxiety disorders.

  7. Community structure of aquatic insects in the Esparza River, Costa Rica.

    PubMed

    Herrera-Vásquez, Jonathan

    2009-01-01

    This study focused on the structure of the aquatic insect community in spatial and temporal scales in the Esparza River. The river was sampled for one full year throughout 2007. During the dry season low flow months, five sampling points were selected in two different habitats (currents and pools), with five replicates per sample site. During the wet season with peak rain, only the data in the "current habitat" were sampled at each site. Specimens present in the different substrates were collected and preserved in situ. A nested ANOVA was then applied to the data to determine richness and density as the response variables. The variations in temporal and spatial scales were analyzed using width, depth and discharge of the river, and then analyzed using a nested ANOVA. Only a correlation of 51% similarity in richness was found, while in spatial scale, richness showed significant variation between sampling sites, but not between habitats. However, the temporal scale showed significant differences between habitats. Density showed differences between sites and habitats during the dry season in the spatial scale, while in the temporal scale significant variation was found between sampling sites. Width varied between habitats during the dry season, but not between sampling points. Depth showed differences between sampling sites and season. This work studies the importance of community structure of aquatic insects in rivers, and its relevance for the quality of water in rivers and streams.

  8. The electrical conductivities of the DSS-13 beam-waveguide antenna shroud material and other antenna reflector surface materials

    NASA Technical Reports Server (NTRS)

    Otoshi, T. Y.; Franco, M. M.; Reilly, H. F., Jr.

    1992-01-01

    A significant amount of noise temperature can potentially be generated by currently unknown dissipative losses in the beam waveguide (BWG) shroud. The amount of noise temperature contribution from this source is currently being studied. In conjunction with this study, electrical conductivity measurements were made on samples of the DSS-13 BWG shroud material at 8.420 GHz. The effective conductivities of unpainted and painted samples of the BWG shroud were measured to be 0.01 x 10(exp 7) and 0.0036 x 10(exp 7) mhos/m, respectively. This value may be compared with 5.66 x 10(exp 7) mhos/m for high conductivity copper.

  9. Water Quality on the Prairie Band Potawatomi Reservation, Northeastern Kansas, June 1996 through August 2006

    USGS Publications Warehouse

    Schmidt, Heather C. Ross; Mehl, Heidi E.; Pope, Larry M.

    2007-01-01

    This report describes surface- and ground-water-quality data collected on the Prairie Band Potawatomi Reservation in northeastern Kansas from November 2003 through August 2006 (hereinafter referred to as the 'current study period'). Data from this study period are compared to results from June 1996 through August 2003, which are published in previous reports as part of a multiyear cooperative study with the Prairie Band Potawatomi Nation. Surface and ground water are valuable resources to the Prairie Band Potawatomi Nation as tribal members currently (2007) use area streams to fulfill subsistence hunting and fishing needs and because ground water potentially could support expanding commercial enterprise and development. Surface-water-quality samples collected from November 2003 through August 2006 were analyzed for physical properties, dissolved solids, major ions, nutrients, trace elements, pesticides, fecal-indicator bacteria, suspended-sediment concentration, and total suspended solids. Ground-water samples were analyzed for physical properties, dissolved solids, major ions, nutrients, trace elements, pesticides, and fecal-indicator bacteria. Chemical oxygen demand and volatile organic compounds were analyzed in all three samples from one monitoring well located near a construction and demolition landfill on the reservation, and in one sample from another well in the Soldier Creek drainage basin. Previous reports published as a part of this ongoing study identified total phosphorus, triazine herbicides, and fecal coliform bacteria as exceeding their respective water-quality criteria in surface water on the reservation. Previous ground-water assessments identified occasional sample concentrations of dissolved solids, sodium, sulfate, boron, iron, and manganese as exceeding their respective water-quality criteria. Fifty-six percent of the 55 surface-water samples collected during the current study period and analyzed for total phosphorus exceeded the goal of 0.1 mg/L (milligram per liter) established by the U.S. Environmental Protection Agency (USEPA) to limit cultural eutrophication in flowing water. Concentrations of dissolved solids frequently exceeded the USEPA Secondary Drinking-Water Regulation (SDWR) of 500 mg/L in samples from two sites. Concentrations of sodium exceeded the Drinking-Water Advisory of 20 mg/L set by USEPA in almost 50 percent of the surface-water samples. All four samples analyzed for atrazine concentrations showed some concentration of the pesticide, but none exceeded the Maximum Contaminant Level (MCL) established for drinking water by USEPA of 3.0 ?g/L (micrograms per liter) as an annual average. A triazine herbicide screen was used on 55 surface-water samples, and triazine compounds were frequently detected. Triazine herbicides and their degradates are listed on the USEPA Contaminant Candidate List. In 41 percent of surface-water samples, densities of Escherichia coli (E. coli) bacteria exceeded the primary contact, single-sample maximum in public-access bodies of water (1,198 colonies per 100 milliliters of water for samples collected between April 1 and October 31) set by the Kansas Department of Health and Environment (KDHE). Nitrite plus nitrate concentrations in all three water samples from 1 of 10 monitoring wells exceeded the MCL of 10 mg/L established by USEPA for drinking water. Arsenic concentrations in all three samples from one well exceeded the proposed MCL of 10 ?g/L established by USEPA for drinking water. Boron also exceeded the drinking-water advisory in three samples from one well, and iron concentrations were higher than the SDWR in water from four wells. There was some detection of pesticides in ground-water samples from three of the wells, and one detection of the volatile organic compound diethyl ether in one well. Concentrations of dissolved solids exceeded the SDWR in 20 percent of ground-water samples collected during the current study period, and concentration

  10. High pressure system for 3-D study of elastic anisotropy

    NASA Astrophysics Data System (ADS)

    Lokajicek, T.; Pros, Z.; Klima, K.

    2003-04-01

    New high pressure system was designed for the study of elastic anisotropy of condensed matter under high confining pressure up to 700 MPa. Simultaneously could be measured dynamic and static parameters: a) dynamic parameters by ultrasonic sounding, b) static parameters by measuring of spherical sample deformation. The measurement is carried out on spherical samples diameter 50 +/- 0.01 mm. Higher value of confining pressure was reached due to the new construction of sample positioning unit. The positioning unit is equipped with two Portecap step motors, which are located inside the vessel and make possible to rotate with the sphere and couple of piezoceramic transducers. Sample deformation is measured in the same direction as ultrasonic signal travel time. Only electric leads connects inner part of high pressure vessel with surrounding environment. Experimental set up enables: - simultaneous P-wave ultrasonic sounding, - measurement of current sample deformation at sounding points, - measurement of current value of confining pressure and - measurement of current stress media temperature. Air driven high pressure pump Haskel is used to produce high value of confining pressure up to 700 MPa. Ultrasonic signals are recorded by digital scope Agilent 54562 with sampling frequency 100 MHz. Control and measuring software was developed under Agilent VEE software environment working under MS Win 2000 operating system. Measuring set up was tested by measurement of monomineral spherical samples of quartz and corundum. Both of them have trigonal symmetry. The measurement showed that the P-wave velocity range of quartz was between 5.7-7.0 km/sec. and velocity range of corundum was between 9.7-10.9 km/sec. High pressure resistant LVDT transducers Mesing together with Intronix electronic unit were used to monitor sample deformation. Sample deformation is monitored with the accuracy of 0.1 micron. All test measurements proved the good accuracy of the whole measuring set up. This project was supported by Grant Agency of the Czech Republic No.: 205/01/1430.

  11. How College Students Conceptualize and Practice Responsible Drinking

    ERIC Educational Resources Information Center

    Barry, Adam E.; Goodson, Patricia

    2011-01-01

    Objective: This study sought to employ a mixed-methods approach to (a) qualitatively explore responsible drinking beliefs and behaviors among a sample of college students, and (b) quantitatively assess the prevalence of those behaviors. Participants: Convenience samples, drawn from currently enrolled students attending a large public university in…

  12. Depression and Delinquency Covariation in an Accelerated Longitudinal Sample of Adolescents

    ERIC Educational Resources Information Center

    Kofler, Michael J.; McCart, Michael R.; Zajac, Kristyn; Ruggiero, Kenneth J.; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2011-01-01

    Objectives: The current study tested opposing predictions stemming from the failure and acting out theories of depression-delinquency covariation. Method: Participants included a nationwide longitudinal sample of adolescents (N = 3,604) ages 12 to 17. Competing models were tested with cohort-sequential latent growth curve modeling to determine…

  13. College Students' Perceptions of Collective Efficacy: Results from a Nonurban Sample

    ERIC Educational Resources Information Center

    Domoff, Sarah E.; Hayman, Jennifer; Tompsett, Carolyn J.

    2012-01-01

    Although the relationship between neighborhood characteristics and collective efficacy is well established in urban populations with community samples, it is unclear if this relationship holds in rural areas. The current study fills this gap by assessing the perceptions of adolescents from nonurban areas to examine the relationships between…

  14. Migration monitoring with automated technology

    Treesearch

    Rhonda L. Millikin

    2005-01-01

    Automated technology can supplement ground-based methods of migration monitoring by providing: (1) unbiased and automated sampling; (2) independent validation of current methods; (3) a larger sample area for landscape-level analysis of habitat selection for stopover, and (4) an opportunity to study flight behavior. In particular, radar-acoustic sensor fusion can...

  15. Base rate of performance invalidity among non-clinical undergraduate research participants.

    PubMed

    Silk-Eglit, Graham M; Stenclik, Jessica H; Gavett, Brandon E; Adams, Jason W; Lynch, Julie K; Mccaffrey, Robert J

    2014-08-01

    Neuropsychological research frequently uses non-clinical undergraduate participants to evaluate neuropsychological tests. However, a recent study by An and colleagues (2012, Archives of Clinical Neuropsychology, 27, 849-857) called into question that the extent to which the interpretation of these participants' performance on neuropsychological tests is valid. This study found that in a sample of 36 participants, 55.6% exhibited performance invalidity at an initial session and 30.8% exhibited performance invalidity at a follow-up session. The current study attempted to replicate these findings in a larger, more representative sample using a more rigorous methodology. Archival data from 133 non-clinical undergraduate research participants were analyzed. Participants were classified as performance invalid if they failed any one PVT. In the current sample, only 2.26% of participants exhibited performance invalidity. Thus, concerns regarding insufficient effort and performance invalidity when using undergraduate research participants appear to be overstated. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Evaluation of the International Outcome Inventory for Hearing Aids in a veteran sample.

    PubMed

    Smith, Sherri L; Noe, Colleen M; Alexander, Genevieve C

    2009-06-01

    The International Outcome Inventory for Hearing Aids (IOI-HA) was developed as a global hearing aid outcome measure targeting seven outcome domains. The published norms were based on a private-pay sample who were fitted with analog hearing aids. The purpose of this study was to evaluate the psychometric properties of the IOI-HA and to establish normative data in a veteran sample. Survey. The participants were 131 male veterans (mean age of 74.3 years, SD = 7.4) who were issued hearing aids with digital signal processing (DSP). Hearing aids with DSP that were fitted bilaterally between 2005 and 2007. Veterans were mailed two copies of the IOI-HA. The participants were instructed to complete the first copy of the questionnaire immediately and the second copy in two weeks. The completed questionnaires were mailed to the laboratory. The psychometric properties of the questionnaire were evaluated. As suggested by Cox and colleagues, the participants were divided into two categories based on their unaided subjective hearing difficulty. The two categories were (1) those with less hearing difficulty (none-to-moderate category) and (2) those who report more hearing difficulty (moderately severe+ category). The norms from the current veteran sample then were compared to the original, published sample. For each hearing difficulty category, the critical difference values were calculated for each item and for the total score. A factor analysis showed that the IOI-HA in the veteran sample had the identical subscale structure as reported in the original sample. For the total scale, the internal consistency was good (Chronbach's alpha = 0.83), and the test-retest reliability was high (lambda = 0.94). Group and individual norms were developed for both hearing difficulty categories in the veteran sample. For each IOI-HA item, the critical difference scores were < 1.0. This finding suggests that for any item on the IOI-HA, there is a 95 percent chance that an observed change of one response unit between two test sessions reflects a true change in outcome for a given domain. The results of this study confirmed that the psychometric properties of the IOI-HA questionnaire are strong and are essentially the same for the veteran sample and the original private-pay sample. The veteran norms, however, produced higher outcomes than those established originally, possibly because of differences in the population samples and/or hearing aid technology. Clinical and research applications of the current findings are presented. Based on the results from the current study, the norms established here should replace the original norms for use in veterans with current hearing aid technology.

  17. Evaluating mixed samples as a source of error in non-invasive genetic studies using microsatellites

    USGS Publications Warehouse

    Roon, David A.; Thomas, M.E.; Kendall, K.C.; Waits, L.P.

    2005-01-01

    The use of noninvasive genetic sampling (NGS) for surveying wild populations is increasing rapidly. Currently, only a limited number of studies have evaluated potential biases associated with NGS. This paper evaluates the potential errors associated with analysing mixed samples drawn from multiple animals. Most NGS studies assume that mixed samples will be identified and removed during the genotyping process. We evaluated this assumption by creating 128 mixed samples of extracted DNA from brown bear (Ursus arctos) hair samples. These mixed samples were genotyped and screened for errors at six microsatellite loci according to protocols consistent with those used in other NGS studies. Five mixed samples produced acceptable genotypes after the first screening. However, all mixed samples produced multiple alleles at one or more loci, amplified as only one of the source samples, or yielded inconsistent electropherograms by the final stage of the error-checking process. These processes could potentially reduce the number of individuals observed in NGS studies, but errors should be conservative within demographic estimates. Researchers should be aware of the potential for mixed samples and carefully design gel analysis criteria and error checking protocols to detect mixed samples.

  18. Designing single- and multiple-shell sampling schemes for diffusion MRI using spherical code.

    PubMed

    Cheng, Jian; Shen, Dinggang; Yap, Pew-Thian

    2014-01-01

    In diffusion MRI (dMRI), determining an appropriate sampling scheme is crucial for acquiring the maximal amount of information for data reconstruction and analysis using the minimal amount of time. For single-shell acquisition, uniform sampling without directional preference is usually favored. To achieve this, a commonly used approach is the Electrostatic Energy Minimization (EEM) method introduced in dMRI by Jones et al. However, the electrostatic energy formulation in EEM is not directly related to the goal of optimal sampling-scheme design, i.e., achieving large angular separation between sampling points. A mathematically more natural approach is to consider the Spherical Code (SC) formulation, which aims to achieve uniform sampling by maximizing the minimal angular difference between sampling points on the unit sphere. Although SC is well studied in the mathematical literature, its current formulation is limited to a single shell and is not applicable to multiple shells. Moreover, SC, or more precisely continuous SC (CSC), currently can only be applied on the continuous unit sphere and hence cannot be used in situations where one or several subsets of sampling points need to be determined from an existing sampling scheme. In this case, discrete SC (DSC) is required. In this paper, we propose novel DSC and CSC methods for designing uniform single-/multi-shell sampling schemes. The DSC and CSC formulations are solved respectively by Mixed Integer Linear Programming (MILP) and a gradient descent approach. A fast greedy incremental solution is also provided for both DSC and CSC. To our knowledge, this is the first work to use SC formulation for designing sampling schemes in dMRI. Experimental results indicate that our methods obtain larger angular separation and better rotational invariance than the generalized EEM (gEEM) method currently used in the Human Connectome Project (HCP).

  19. The proto-oncogene KRAS and BRAF profiles and some clinical characteristics in colorectal cancer in the Turkish population.

    PubMed

    Ozen, Filiz; Ozdemir, Semra; Zemheri, Ebru; Hacimuto, Gizem; Silan, Fatma; Ozdemir, Ozturk

    2013-02-01

    The aim of the current study was to investigate the prevalence and predictive significance of the KRAS and BRAF mutations in Turkish patients with colorectal cancer (CRC). Totally, 53 fresh tumoral tissue specimens were investigated in patients with CRC. All specimens were obtained during routine surgery of patients who were histopathologically diagnosed and genotyped for common KRAS and BRAF point mutations. After DNA extraction, the target mutations were analyzed using the AutoGenomics INFINITI(®) assay, and some samples were confirmed by quantitative real-time polymerase chain reaction fluorescence melting curve analyses. KRAS mutations were found in 26 (49.05%) CRC samples. Twenty-seven samples (50.95%) had wild-type profiles for KRAS codon 12, 13, and 61 in the current cohort. In 17 (65.38%) samples, codon 12; in 7 (26.93%) samples, codon 13; and in 2 (7.69%) samples, codon 61 were found to be mutated, particularly in grade 2 of tumoral tissues. No point mutation was detected in BRAF codon Val600Glu for the studied CRC patients. Our study, based on a representative collection of human CRC tumors, indicates that KRAS gene mutations were detected in 49.05% of the samples, and the most frequent mutation was in the G12D codon. Results also showed that codons 12 and 13 of KRAS are relatively frequently without BRAF mutation in a CRC cohort from the Turkish population.

  20. Test Report - Fault Current Through Graphite Filament Reinforced Plastic

    NASA Technical Reports Server (NTRS)

    Evans, R. W.

    1997-01-01

    Tests were performed to determine the damage to samples of composite material when a current carrying wire is shorted to the surface of the composite material, and to determine whether enough current can flow through the material to blow a fuse before damage can occur. Fault current tests were performed on samples of graphite epoxy materials. Samples consisted of six layers of IM7 graphite fiber mat in Hercules 8552 epoxy resin. A variable power supply provided up to 35 amps of current. The high voltage side of the power supply was attached to a wire at the end of a hinged arm, and the low side was attached to the edge of the sample. To test joints, the return was connected to the edge of one sample, and the high side was shorted to the top of the other sample. Tests show that when current exceeds approximately 5 amps, the graphite glows, and the epoxy melts out at the shorted contact. At higher current levels the epoxy burns. At voltages above 15 volts the epoxy outer coat is easily broken, and fire, flame, and a rise in current occur suddenly. When joints are introduced, resistance is increased, and the maximum current resulting from a short circuit to the graphite epoxy is reduced. This condition can easily result in fault current lower than the circuit breaker limit and higher than the 5 amp ignition level. The shorting contact and the joint become hot spots with melting epoxy, smoke, and fire.

  1. New and Improved? A Comparison of the Original and Revised Versions of the Structured Interview of Reported Symptoms

    ERIC Educational Resources Information Center

    Green, Debbie; Rosenfeld, Barry; Belfi, Brian

    2013-01-01

    The current study evaluated the accuracy of the Structured Interview of Reported Symptoms, Second Edition (SIRS-2) in a criterion-group study using a sample of forensic psychiatric patients and a community simulation sample, comparing it to the original SIRS and to results published in the SIRS-2 manual. The SIRS-2 yielded an impressive…

  2. Assessing the Relationship between Family Mealtime Communication and Adolescent Emotional Well-Being Using the Experience Sampling Method

    ERIC Educational Resources Information Center

    Offer, Shira

    2013-01-01

    While most prior research has focused on the frequency of family meals the issue of which elements of family mealtime are most salient for adolescents' well-being has remained overlooked. The current study used the experience sampling method, a unique form of time diary, and survey data drawn from the 500 Family Study (N = 237 adolescents with…

  3. Psychopathy in Adolescence and Criminal Recidivism in Young Adulthood. Longitudinal Results from a Multiethnic Sample of Youthful Offenders

    ERIC Educational Resources Information Center

    Edens, John F.; Cahill, Melissa A.

    2007-01-01

    Very few studies to date have examined the long-term predictive validity of psychopathy among juveniles. The current study reports general and violent recidivism data for an ethnically heterogeneous sample of male offenders (n = 75) who had been administered the Psychopathy Checklist: Youth Version (PCL: YV) in 1996 when they were on average 16…

  4. Qualification of serological infectious disease assays for the screening of samples from deceased tissue donors.

    PubMed

    Kitchen, A D; Newham, J A

    2011-05-01

    Whilst some of the assays used for serological screening of post-mortem blood samples from deceased tissue donors in some countries have been specifically validated by the manufacturer for this purpose, a significant number of those currently in use globally have not. Although specificity has previously been considered a problem in the screening of such samples, we believe that ensuring sensitivity is more important. The aim of this study was to validate a broader range of assays for the screening of post-mortem blood samples from deceased tissue donors. Six microplate immunoassays currently in use within National Health Service Blood and Transplant (NHSBT) for the screening of blood, tissue and stem cell donations were included. Representative samples from confirmed positive donors were titrated in screen negative post-mortem samples in parallel with normal pooled negative serum to determine if there was any inhibition with the post-mortem samples. There were no significant differences seen (P < 0.005) between the dilution curves obtained for the positive samples diluted in post-mortem samples and normal pooled sera. Although small numbers of samples were studied, it can be surmised that the post-mortem blood samples from deceased tissue donors, collected according to United Kingdom guidelines, are a suitable substrate for the assays evaluated. No diminution of reactivity was seen when dilution with sera from deceased donors was compared to dilution using pooled serum from live donors. In the absence of genuine low titre positive post-mortem samples, the use of samples spiked with various levels of target material provides a means of qualifying serological screening assays used by NHSBT for the screening of post-mortem blood samples from deceased tissue donors.

  5. The Apollo 17 samples: The Massifs and landslide

    NASA Technical Reports Server (NTRS)

    Ryder, Graham

    1992-01-01

    More than 50 kg of rock and regolith samples, a little less than half the total Apollo 17 sample mass, was collected from the highland stations at Taurus-Littrow. Twice as much material was collected from the North Massif as from the South Massif and its landslide (the apparent disproportionate collecting at the mare sites is mainly a reflection of the large size of a few individual basalt samples). Descriptions of the collection, documentation, and nature of the samples are given. A comprehensive catalog is currently being produced. Many of the samples have been intensely studied over the last 20 years and some of the rocks have become very familiar and depicted in popular works, particularly the dunite clast (72415), the troctolite sample (76535), and the station 6 boulder samples. Most of the boulder samples have been studied in Consortium mode, and many of the rake samples have received a basic petrological/geochemical characterization.

  6. Evaluation of constant current alternating current iontophoresis for transdermal drug delivery.

    PubMed

    Yan, Guang; Li, S Kevin; Higuchi, William I

    2005-12-10

    Previous studies in our laboratory have demonstrated that alternating current (AC) iontophoresis can significantly decrease skin electric resistance and enhance the transport of charged permeants across skin. Flux variability of neutral permeants during AC iontophoresis was also found to be less than that of conventional direct current (DC) iontophoresis. The objectives of the present study were to evaluate flux enhancement of constant current AC transdermal iontophoresis and compare the AC flux with that of constant current DC iontophoresis. Iontophoresis studies of AC amplitude of 1, 2, and 5 mA were conducted in side-by-side diffusion cells with donor solution of 0.015, 0.15, and 1.0 M tetraethylammonium (TEA) chloride and receiver solution of phosphate buffered saline (PBS) using human epidermal membrane (HEM). Conventional constant current DC iontophoresis of 0.2 mA was also performed under similar conditions. TEA and mannitol were the model permeants. The following are the major findings in the present study. The flux of TEA increased proportionally with the AC current for all three TEA chloride concentrations and at the AC frequency used in the present study. When the permeant and its counter ion were the only ionic species in the donor chamber, the fluxes during DC iontophoresis were weakly dependent of its donor concentration. The fluxes of TEA during constant current AC iontophoresis were moderately related to the donor concentration with the highest TEA flux observed under the 1.0 M TEA chloride condition although the relationship between flux and donor concentration was not linear. A trend of decreasing electroosmotic transport with increasing donor TEA chloride concentration was observed with significant sample-to-sample variability during DC iontophoresis. Mannitol permeability was also observed to decrease with increasing TEA chloride concentration in the donor under the AC conditions, but data variability under AC was significantly smaller than that under DC. The results in the present study indicate that constant current AC iontophoresis under conditions tolerable to human (2 and 5 mA) can provide predictable fluxes that were lower than but of comparable magnitude as those of conventional constant current DC iontophoresis (0.2 mA).

  7. Molecular detection of airborne Coccidioides in Tucson, Arizona

    USGS Publications Warehouse

    Chow, Nancy A.; Griffin, Dale W.; Barker, Bridget M.; Loparev, Vladimir N.; Litvintseva, Anastasia P.

    2016-01-01

    Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detectingCoccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.

  8. Demographic, Mental Health, Behavioral, and Psychosocial Factors Associated with Cigarette Smoking Status Among Young Men Who Have Sex with Men: The P18 Cohort Study.

    PubMed

    D'Avanzo, Paul A; Halkitis, Perry N; Yu, Kalvin; Kapadia, Farzana

    2016-10-01

    Young sexual minority men smoke at higher rates relative to heterosexual peers. The purpose of this study was to examine correlates of smoking in a sample of young gay, bisexual, and other men who have sex with men (MSM) who might differ from more general and age-diverse samples of sexual minority individuals and, thus, inform tailored approaches to addressing tobacco use within this population. Data on smoking status were examined in relation to demographics, mental health, substance use behavior, and psychosocial factors. Using multinomial logistic regression, factors were identified that differentiate current and former smokers from never smokers. In bivariate analysis, smoking status was related to demographic, mental health, substance use, and psychosocial factors. Most significantly, smoking status was associated with school enrollment status, current alcohol and marijuana use, and symptoms of depression. Multivariate modeling revealed that, compared to being a never smoker, the odds of current or former smoking were highest among those currently using either alcohol or marijuana. The odds of both current and former smoking were also higher among those reporting greater levels of gay community affinity. Finally, the odds of being a former smoker were higher for those reporting internalized antihomosexual prejudice. This study identifies several factors related to smoking status in a diverse sample of young sexual minority males. These findings should encourage investigations of smoking disparities among younger MSM to look beyond common smoking risk factors in an attempt to understand etiologies that may be unique to this group. Such findings may indicate multiple points of potential intervention aimed at decreasing cigarette smoking within this vulnerable population.

  9. Among a sample of Iranian students, adult attention deficit hyperactivity disorder is related to childhood ADHD, but not to age, gender, socioeconomic status, or birth order--an exploratory study.

    PubMed

    Jahangard, Leila; Haghighi, Mohammad; Bajoghli, Hafez; Holsboer-Trachsler, Edith; Brand, Serge

    2013-10-01

    The aim of the present study was to explore the prevalence of adult attention deficit hyperactivity disorder (ADHD) in young adult Iranian students and to examine gender, birth order, socioeconomic status (SES), and history of ADHD as potential predictors of adult ADHD. A total of 387 young adult students (mean age: 19.6 years; 66.3% females) completed the Adult ADHD Self-Report Scale-V1.1 symptom checklist to assess current symptoms of ADHD and the Wender Utah Rating Scale to assess symptoms of ADHD in childhood and adolescence. Experts' ratings were based on Wender-Reimherr Interview. Self-rated and expert-rated prevalence rates were 16.5% and 13.4%, respectively. Past symptoms of ADHD were correlated with current symptoms. Childhood ADHD, current hyperactivity, and disorganization predicted current ADHD. Among a sample of Iranian students, the prevalence rates of ADHD were higher than estimated rates worldwide. Data also show child ADHD to be associated with adult ADHD; gender, age, birth order, and SES did not seem to influence current symptomatology.

  10. Risk and Protective Factors for Cigarette Use in Young Adolescents in a School Setting: What Could Be Done Better?

    PubMed Central

    Majid, H. A.; Jalaludin, M. Y.; Murray, L.; Cantwell, M.; Su, T. T.

    2015-01-01

    Smoking among Malaysian adolescents remains a public health concern despite concerted efforts in tobacco control. The aims of this study were to examine the prevalence and determinants of current-smoking status in young adolescents. This cross sectional study used the first round of the Malaysian Health and Adolescents Research Team’s prospective cohort study. It was conducted in three States of the Central and Northern regions of Peninsular Malaysia between March and May 2012. The study used the multistage stratified sampling design. A total of 1,342 adolescents of both sexes, aged 12-13 years, were sampled from randomly selected urban and rural national schools. Information on current smoking status and associated factors were collected by a self-administered, pre-tested, validated, structured questionnaire. Seven percent of the samples were current-smokers; the majority (62%) of them started smoking at the age of 11 years or below. The prevalence of current smoking was significantly higher in males (odds ratio [OR] = 2.37; 95% CI: 1.46, 3.84), those who were influenced by smoker friends (OR = 8.35; 95% CI: 4.90, 14.25), who were unaware of the health risks of smoking (OR =1.85; 95% CI: 1.02, 3.36) and who reported a lack of satisfaction about their overall life (OR =3.26; 95% CI: 1.73, 6.12). The study findings provide valuable information to strengthen the existing school-based smoking prevention program through integration of social competence and social influence curricula. The program should empower the young adolescents to refuse tobacco offers, to overcome social influences and to resist peer pressure to avoid starting smoking. Particular focuses to include mental health service to prevent both emotional and behavioural problems are needed. PMID:26068668

  11. Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

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

    Fritz, Brad G.; Abrecht, David G.; Hayes, James C.

    2016-10-31

    Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO 2 from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

  12. Asymptomatic Leishmania Infected Children: A Seroprevalence and Molecular Survey in a Rural Area of Fars Province, Southern Iran.

    PubMed

    Layegh Gigloo, Akram; Sarkari, Bahador; Rezaei, Zahra; Hatam, Gholam Reza; Davami, Mohammad Hassan

    2018-01-01

    The current study aimed to evaluate the seroprevalence of visceral leishmaniasis in asymptomatic healthy children in a rural area of Fars province, Southern Iran. Blood samples were taken from 617 asymptomatic healthy children and serum samples along with buffy coat were separated from the blood. The serum samples were assessed for antibodies against Leishmania infantum by an indirect ELISA and the buffy coats were tested for the presence of L. infantum DNA by molecular method. Of the 617 recruited children, 297 (48.1%) were female and 317 (51.4%) were male. Anti- Leishmania antibodies were detected in 17 (2.8%) of the children. From those 17 seropositive cases, 5 (29.4%) were male and 12 (70.6%) cases were female. Children aged 5-8 years had the highest seroprevalence rate; however, no associations were found between seropositivity to Leishmania and gender or age of the children. Moreover, L. infantum DNA was detected in buffy coat of 8 (1.3%) of 617 children. Three of the PCR-positive cases were seropositive whereas 14 of seropositive subjects (82.3%) were PCR-negative. Findings of the current study revealed a considerable subclinical leishmanial infection in children in the studied rural area in the south of Iran. Results of the current study could be used for surveillance, prevention, and control of VL in the area.

  13. High Voltage, Low Inductance Hydrogen Thyratron Study Program.

    DTIC Science & Technology

    1981-01-01

    E-E Electrode Spacing Ef Cathode Heater Voltage egy Peak Forward Grid Voltage epy Peak Forward Anode Voltage epx Peak Inverse Anode Voltage Eres... electrodes . ........... 68 30 Marx generator used for sample testing. ........... 68 31 Waveforms showing sample holdoff and sample breakdown 73 32...capability (a function of gas pressure and electrode spacing) could be related to its current rise time capability (a function of gas pressure and inductance

  14. Nonclinical dose formulation analysis method validation and sample analysis.

    PubMed

    Whitmire, Monica Lee; Bryan, Peter; Henry, Teresa R; Holbrook, John; Lehmann, Paul; Mollitor, Thomas; Ohorodnik, Susan; Reed, David; Wietgrefe, Holly D

    2010-12-01

    Nonclinical dose formulation analysis methods are used to confirm test article concentration and homogeneity in formulations and determine formulation stability in support of regulated nonclinical studies. There is currently no regulatory guidance for nonclinical dose formulation analysis method validation or sample analysis. Regulatory guidance for the validation of analytical procedures has been developed for drug product/formulation testing; however, verification of the formulation concentrations falls under the framework of GLP regulations (not GMP). The only current related regulatory guidance is the bioanalytical guidance for method validation. The fundamental parameters for bioanalysis and formulation analysis validations that overlap include: recovery, accuracy, precision, specificity, selectivity, carryover, sensitivity, and stability. Divergence in bioanalytical and drug product validations typically center around the acceptance criteria used. As the dose formulation samples are not true "unknowns", the concept of quality control samples that cover the entire range of the standard curve serving as the indication for the confidence in the data generated from the "unknown" study samples may not always be necessary. Also, the standard bioanalytical acceptance criteria may not be directly applicable, especially when the determined concentration does not match the target concentration. This paper attempts to reconcile the different practices being performed in the community and to provide recommendations of best practices and proposed acceptance criteria for nonclinical dose formulation method validation and sample analysis.

  15. Preliminary results on time-resolved ion beam induced luminescence applied to the provenance study of lapis lazuli

    NASA Astrophysics Data System (ADS)

    Czelusniak, C.; Palla, L.; Massi, M.; Carraresi, L.; Giuntini, L.; Re, A.; Lo Giudice, A.; Pratesi, G.; Mazzinghi, A.; Ruberto, C.; Castelli, L.; Fedi, M. E.; Liccioli, L.; Gueli, A.; Mandò, P. A.; Taccetti, F.

    2016-03-01

    This work will present preliminary results concerning the use of time-resolved ion beam induced luminescence applied to provenance studies of lapis lazuli. Measurements were performed at the pulsed beam facility at LABEC laboratory in Florence. Lapis lazuli is a semi-precious gemstone, used as ornament since the early civilizations that can be found in few places on Earth. The importance of this work lies in understanding the origin of various samples of lapis lazuli, from which it may be possible to gain insight into trade routes from ancient times. The samples studied in this work originated from Chile, Afghanistan, Tajikistan, Myanmar, and Siberia. The stones were irradiated with 3 MeV protons and the resulting luminescence was detected by a photomultiplier tube, whose output was acquired using a sampling digitizer VME module (CAEN/V1720). Wavelength discrimination was performed at 430 nm utilizing a range of beam currents. The results showed that, by changing the beam current intensity, one can study different features of lapis lazuli, and this may aid in distinguishing lapis lazuli from different provenances.

  16. Excess current experiment on YBCO tape conductor with metal stabilized layer

    NASA Astrophysics Data System (ADS)

    Tasaki, Kenji; Yazawa, Takashi; Ono, Michitaka; Kuriyama, Toru

    2006-06-01

    Excess current experiments were performed using YBCO tape conductors with a metal stabilized layer on the superconducting layer. The purpose of this research is to obtain the stable criteria of energy dissipation when YBCO tape is forced to flow excess current higher than its critical current. This situation should be considered in power applications. In the experiments short-length samples were immersed in liquid nitrogen and several cycles of 50Hz sinusoidal current were supplied to the samples by an induction voltage regulator. The critical current of the samples was about 110 A. With pulse length as long as 60 ms, YBCO tapes were able to be energized up to twelve times as the critical current without electrical or mechanical deformation. Prior to the excess current experiments, temperature dependency of resistance of the sample was measured so that the temperature rise was estimated by the generated resistance. It is found that YBCO tapes with a copper stabilized layer can be transiently heated to over 400K without degradation.

  17. Patterns of current and lifetime substance use in schizophrenia.

    PubMed

    Fowler, I L; Carr, V J; Carter, N T; Lewin, T J

    1998-01-01

    A structured interview and standardized rating scales were used to assess a sample of 194 outpatients with schizophrenia in a regional Australian mental health service for substance use, abuse, and dependence. Case manager assessments and urine drug screens were also used to determine substance use. Additional measurements included demographic information, history of criminal charges, symptom self-reports, personal hopefulness, and social support. The sample was predominantly male and showed relative instability in accommodations, and almost half had a history of criminal offenses, most frequently drug or alcohol related. The 6-month and lifetime prevalence of substance abuse or dependence was 26.8 and 59.8 percent, respectively, with alcohol, cannabis, and amphetamines being the most commonly abused substances. Current users of alcohol comprised 77.3 percent and current users of other nonprescribed substances (excluding tobacco and caffeine) comprised 29.9 percent of the sample. Rates of tobacco and caffeine consumption were high. There was a moderate degree of concordance between case manager determinations of a substance-use problem and research diagnoses. Subjects with current or lifetime diagnoses of substance abuse/dependence were predominantly young, single males with higher rates of criminal charges; however, there was no evidence of increased rates of suicide attempts, hospital admissions, or daily doses of antipsychotic drugs in these groups compared with subjects with no past or current diagnosis of substance abuse or dependence. Subjects with a current diagnosis of substance use were younger at first treatment and currently more symptomatic than those with no past or current substance use diagnosis. The picture emerging from this study replicates the high rate of substance abuse in persons with schizophrenia reported in North American studies but differs from the latter in finding a slightly different pattern of substances abused (i.e., absence of cocaine), reflecting relative differences in the availability of certain drugs.

  18. Relationship between Dispositional Mindfulness and Substance Use: Findings from a Clinical Sample

    PubMed Central

    Bowen, Sarah; Enkema, Matthew C.

    2014-01-01

    There has been rapidly increasing interest over the past decade in the potential of mindfulness-based approaches to psychological and medical treatment, including a recent growth in the area of substance abuse. Thus, the relationship between trait mindfulness and substance use has been explored in several studies. Results, however, have been mixed. While several studies of college student populations have evinced positive correlations between levels of trait mindfulness and substance use, the opposite seems to be true in clinical samples, with multiple studies showing a negative association. The current study reviews research in both non-treatment seeking college students and in clinical samples, and examines the relationship between trait mindfulness and substance dependence in a clinical sample (N = 281). Further, the study assesses the moderating effect of avoidant coping that might explain the disparate findings in the clinical versus nonclinical samples. PMID:24290208

  19. In vitro and in vivo comparisons of constant resistance AC iontophoresis and DC iontophoresis.

    PubMed

    Li, S Kevin; Higuchi, William I; Zhu, Honggang; Kern, Steven E; Miller, David J; Hastings, Matthew S

    2003-09-04

    A previous in vitro constant electrical resistance alternating current (AC) iontophoresis study with human epidermal membrane (HEM) and a model neutral permeant has shown less inter- and intra-sample variability in iontophoretic transport relative to conventional constant direct current (DC) iontophoresis. The objectives of the present study were to address the following questions. (1) Can the skin electrical resistance be maintained at a constant level by AC in humans in vivo? (2) Are the in vitro data with HEM representative of those in vivo? (3) Does constant skin resistance AC iontophoresis have less inter- and intra-sample variability than conventional constant current DC iontophoresis in vivo? (4) What are the electrical and the barrier properties of skin during iontophoresis in vivo? In the present study, in vitro HEM experiments were carried out with the constant resistance AC and the conventional constant current DC methods using mannitol and glucose as the neutral model permeants. In vivo human experiments were performed using glucose as the permeant with a constant skin resistance AC only protocol and two conventional constant current DC methods (continuous constant current DC and constant current DC with its polarity alternated every 10 min with a 3:7 on:off duty cycle). Constant current DC iontophoresis was conducted with commercial constant current DC devices, and constant resistance AC iontophoresis was carried out by reducing and maintaining the skin resistance at a constant target value with AC supplied from a function generator. This study shows that (1) skin electrical resistance can be maintained at a constant level during AC iontophoresis in vivo; (2) HEM in vitro and human skin in vivo demonstrate similar electrical and barrier properties, and these properties are consistent with our previous findings; (3) there is general qualitative and semi-quantitative agreement between the HEM data in vitro and human skin data in vivo; and (4) constant skin resistance AC iontophoresis generally provides less inter- and intra-subject variability than conventional constant current DC.

  20. Mental disorders in Italian prisoners: results of the REDiMe study.

    PubMed

    Macciò, Annalisa; Meloni, Francesca Romana; Sisti, Davide; Rocchi, Marco Bruno Luigi; Petretto, Donatella Rita; Masala, Carmelo; Preti, Antonio

    2015-02-28

    The goal of the study was to estimate the prevalence of current and lifetime mental disorders in a consecutive sample (n=300) of detainees and prison inmates held in an Italian prison and compare it with the prevalence observed in a sample randomized from the community (n=300) within the same age interval (18-55 years) and sex proportion of prisoners, and with a similar socio-economic status. Psychiatric disorders were identified with the Mini International Neuropsychiatric Interview (MINI). Current psychiatric disorders were present in 58.7% of prisoners and 8.7% of the comparison group. Lifetime psychiatric disorders were present in 88.7% of prisoners and 15.7% of the comparison group. Current anxiety disorders and current stress-related disorders were related to prisoners serving their first-ever prison sentence. A variable fraction of prisoners with an ongoing psychopathology is not diagnosed or does not receive proper treatment. The provision of effective treatment to prisoners with psychiatric disorders might have potentially substantial public health benefits. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Development of eddy current microscopy for high resolution electrical conductivity imaging using atomic force microscopy.

    PubMed

    Nalladega, V; Sathish, S; Jata, K V; Blodgett, M P

    2008-07-01

    We present a high resolution electrical conductivity imaging technique based on the principles of eddy current and atomic force microscopy (AFM). An electromagnetic coil is used to generate eddy currents in an electrically conducting material. The eddy currents generated in the conducting sample are detected and measured with a magnetic tip attached to a flexible cantilever of an AFM. The eddy current generation and its interaction with the magnetic tip cantilever are theoretically modeled using monopole approximation. The model is used to estimate the eddy current force between the magnetic tip and the electrically conducting sample. The theoretical model is also used to choose a magnetic tip-cantilever system with appropriate magnetic field and spring constant to facilitate the design of a high resolution electrical conductivity imaging system. The force between the tip and the sample due to eddy currents is measured as a function of the separation distance and compared to the model in a single crystal copper. Images of electrical conductivity variations in a polycrystalline dual phase titanium alloy (Ti-6Al-4V) sample are obtained by scanning the magnetic tip-cantilever held at a standoff distance from the sample surface. The contrast in the image is explained based on the electrical conductivity and eddy current force between the magnetic tip and the sample. The spatial resolution of the eddy current imaging system is determined by imaging carbon nanofibers in a polymer matrix. The advantages, limitations, and applications of the technique are discussed.

  2. Effects of the Spock Videogame on Improving Emotional Intelligence in Adolescents

    ERIC Educational Resources Information Center

    Cejudo, Javier; Latorre, Sebastián

    2015-01-01

    Introduction: The aim of the present research is to experimentally assess the effects of a videogame program ("Spock") for improving emotional intelligence (EI) as an ability among a sample of adolescents. Method: The sample was made up of 92 adolescents, aged 17 to 19, who were currently studying the second year of…

  3. Gender Differences in Symptoms of Autism Spectrum Disorders in Toddlers

    ERIC Educational Resources Information Center

    Sipes, Megan; Matson, Johnny L.; Worley, Julie A.; Kozlowski, Alison M.

    2011-01-01

    Gender differences in symptoms representing the triad of impairments of Autism Spectrum Disorders remain unclear. To date, the majority of research conducted on this topic has utilized samples of older children. Thus, the purpose of the current study was to utilize a sample of toddlers to investigate gender differences in symptom endorsements of…

  4. Teacher and Student-Focused Approaches: Influence of Learning Approach and Self-Efficacy in a Psychology Postgraduate Sample

    ERIC Educational Resources Information Center

    Kaye, Linda K.; Brewer, Gayle

    2013-01-01

    The current study examined approaches to teaching in a postgraduate psychology sample. This included considering teaching-focused (information transfer) and student-focused (conceptual changes in understanding) approaches to teaching. Postgraduate teachers of psychology (N = 113) completed a questionnaire measuring their use of a teacher- or…

  5. Glycemic Control in a Clinic-Based Sample of Diabetics in M'Bour Senegal

    ERIC Educational Resources Information Center

    BeLue, Rhonda; Ndiaye, Khadidiatou; NDao, Fatou; Ba, Fatou Niass Niang; Diaw, Mor

    2016-01-01

    Background: Sub-Saharan Africa (SSA) including Senegal is faced with a significant and increasing burden of type 2 diabetes. However, little information is available about diabetes management among Senegalese diabetics. Purpose: The current study aims to describe the level of glycemic control among a convenience sample of diabetics who receive…

  6. Interventions Used with an Australian Sample of Preschool Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Carter, Mark; Roberts, Jacqueline; Williams, Katrina; Evans, David; Parmenter, Trevor; Silove, Natalie; Clark, Trevor; Warren, Anthony

    2011-01-01

    This study examined the previous and current range of educational, therapy, medical and CAM interventions used by a clearly described Australian sample of 84 families of preschool-aged children with autism spectrum disorders who were enrolled in a controlled trial of early intervention services. With regard to educational and therapy…

  7. Labor Force Participation Rates among Working-Age Individuals with Visual Impairments

    ERIC Educational Resources Information Center

    Kelly, Stacy M.

    2013-01-01

    The present study analyzes four consecutive years of monthly labor force participation rates reported by the Current Population Survey that included nationally representative samples of the general U.S. population and nationally representative samples of the U.S. population with specifically identified disabilities. Visual impairment is one of the…

  8. Prevalence and Correlates of Multiple Victimization in a Nation-Wide Adolescent Sample

    ERIC Educational Resources Information Center

    Romano, Elisa; Bell, Tessa; Billette, Jean-Michel

    2011-01-01

    Objectives: Adolescents often experience different types of victimization across a specified period of time in different situations. These multiple victimization experiences can have a number of deleterious effects on psychosocial well-being. To expand on research gathered primarily from US samples, the current study estimated the prevalence of…

  9. An Investigation of Sample Size Splitting on ATFIND and DIMTEST

    ERIC Educational Resources Information Center

    Socha, Alan; DeMars, Christine E.

    2013-01-01

    Modeling multidimensional test data with a unidimensional model can result in serious statistical errors, such as bias in item parameter estimates. Many methods exist for assessing the dimensionality of a test. The current study focused on DIMTEST. Using simulated data, the effects of sample size splitting for use with the ATFIND procedure for…

  10. Exploring the Impact of Chronic Tic Disorders on Youth: Results from the Tourette Syndrome Impact Survey

    ERIC Educational Resources Information Center

    Conelea, Christine A.; Woods, Douglas W.; Zinner, Samuel H.; Budman, Cathy; Murphy, Tanya; Scahill, Lawrence D.; Compton, Scott N.; Walkup, John

    2011-01-01

    Prior research has demonstrated that chronic tic disorders (CTD) are associated with functional impairment across several domains. However, methodological limitations, such as data acquired by parental report, datasets aggregated across child and adult samples, and small treatment-seeking samples, curtail interpretation. The current study explored…

  11. Potentiometric determination of trypsin using a polymeric membrane polycation-sensitive electrode based on current-controlled reagent delivery.

    PubMed

    Chen, Yan; Ding, Jiawang; Qin, Wei

    2012-12-01

    A potentiometric biosensor for the determination of trypsin is described based on current-controlled reagent delivery. A polymeric membrane protamine-sensitive electrode with dinonylnaphthalene sulfonate as cation exchanger is used for in situ generation of protamine. Diffusion of protamine across the polymeric membrane can be controlled precisely by applying an external current. The hydrolysis catalyzed with trypsin in sample solution decreases the concentration of free protamine released at the sample-membrane interface and facilitates the stripping of protamine out of the membrane surface via the ion-exchange process with sodium ions from the sample solution, thus decreasing the membrane potential, by which the protease can be sensed potentiometrically. The influences of anodic current amplitude, current pulse duration and protamine concentration in the inner filling solution on the membrane potential response have been studied. Under optimum conditions, the proposed protamine-sensitive electrode is useful for continuous and reversible detection of trypsin over the concentration range of 0.5-5UmL(-1) with a detection limit of 0.3UmL(-1). The proposed detection strategy provides a rapid and reagentless way for the detection of protease activities and offers great potential in the homogeneous immunoassays using proteases as labels. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Availability of a fetal goat tongue cell line ZZ-R 127 for isolation of Foot-and-mouth disease virus (FMDV) from clinical samples collected from animals experimentally infected with FMDV.

    PubMed

    Fukai, Katsuhiko; Onozato, Hiroyuki; Kitano, Rie; Yamazoe, Reiko; Morioka, Kazuki; Yamada, Manabu; Ohashi, Seiichi; Yoshida, Kazuo; Kanno, Toru

    2013-11-01

    The availability of the fetal goat tongue cell line ZZ-R 127 for the isolation of Foot-and-mouth disease virus (FMDV) has not been evaluated using clinical samples other than epithelial suspensions. Therefore, in the current study, the availability of ZZ-R 127 cells for the isolation of FMDV was evaluated using clinical samples (e.g., sera, nasal swabs, saliva, feces, and oropharyngeal fluids) collected from animals experimentally infected with an FMDV isolate. Virus isolation rates for the ZZ-R 127 cells were statistically higher than those for the porcine kidney cell line (IB-RS-2) in experimental infections using cattle, goats, and pigs (P < 0.01). Virus titers in the ZZ-R 127 cells were also statistically higher than those in the IB-RS-2 cells. The availability of ZZ-R 127 cells for the isolation of FMDV not only from epithelial suspensions but also from other clinical samples was confirmed in the current study.

  13. Confirmatory factor analysis of the School Refusal Assessment Scale – Revised in an African American community sample

    PubMed Central

    Lyon, Aaron R.

    2010-01-01

    The current study used confirmatory factor analysis techniques to investigate the construct validity of the child version of the School Refusal Assessment Scale – Revised (SRAS-R) in a community sample of low socioeconomic status, urban, African American fifth and sixth graders (n = 174). The SRAS-R is the best-researched measure of school refusal behavior in youth and typically yields four functional dimensions. Results of the investigation suggested that a modified version of the four-factor model, in which three items from the tangible reinforcement dimension are removed, may have construct validity in the current sample of youth. In addition, youth endorsement of the dimension measuring avoidance of social and/or evaluative situations was positively associated with unexcused absences. Implications for further psychometric research and early identification and prevention of problematic absenteeism in low-SES, ethnic minority community samples are highlighted. PMID:20567603

  14. Assessing Intimate Relationships of Chinese Couples in Taiwan Using the Marital Satisfaction Inventory-Revised.

    PubMed

    Lou, Yu-Chiung; Lin, Chien-Heng; Chen, Chien-Min; Balderrama-Durbin, Christina; Snyder, Douglas K

    2016-06-01

    The current study examined the psychometric characteristics of the Chinese translation of the Marital Satisfaction Inventory-Revised (MSI-R) in a community sample of 117 couples from Taiwan. The Chinese MSI-R demonstrated moderate to strong internal consistency. Confirmatory factor analysis revealed similar scale factor structures in the Taiwanese and U.S. standardization samples. Mean profile comparisons between the current Taiwanese sample and the original MSI-R standardization sample revealed statistically significant but small differences on several subscales. Overall, the psychometric characteristics of the Chinese MSI-R lend support to its use with couples from diverse cultural backgrounds whose sole or preferred language is Chinese. It may also be appropriate to use the MSI-R in clinical settings for prevention or intervention efforts directed at Chinese-speaking couples. The implications of these findings for clinical and research purposes are discussed. © The Author(s) 2015.

  15. Extended Late-Cretaceous Magnetostratigraphy of the James Ross Basin Island, Antarctica

    NASA Astrophysics Data System (ADS)

    Chaffee, T. M.; Mitchell, R.; Slotznick, S. P.; Buz, J.; Biasi, J.; O'Rourke, J.; Sousa, F.; Flannery, D.; Fu, R. R.; Kirschvink, J. L.

    2017-12-01

    Sediments in the James Ross Island Basin (JRB) in the West Antarctic Peninsula contain one of the world's highest-resolution records of the late Cretaceous period, including the end-Cretaceous (K-Pg) mass extinction event. However, the geological record of this region has been poorly studied, limited in the past only to the relative dating of local fossils. Recent studies of this region have provided only low-resolution data, with gaps of greater than 0.5 million years between samples where no data was collected. A high-resolution magnetostratigraphic sampling and analysis is necessary in order to accurately determine the age of the JRB sediments and connect them to the global time record. During the 2016 field season in Antarctica, our team collected nearly 1,300 sample cores from JRB sediments using a diamond-tipped, gasoline powered coring drill. Drill sites were densely clustered across bedding in order to obtain a high-resolution record of magnetostratigraphy, permitting the recognition of distinct, high-resolution units of time (<50 thousand years) present in local stratigraphy Our current results come from thermal demagnetization of the characteristic remanance (ChRM) of a group of over 300 of these samples from the Brandy Bay area which constrain the end of the Cretaceous Superchron (C34N) and the C34N/C34R reversal and allow us to investigate the presence of geomagnetic excursions before the end of superchron. These samples span in age from the top of C34N to the mid-Maastrichtian. We also test the Late Cretaceous True Polar Wander (TPW) hypothesis. Current theories on the global extent of TPW are not substantiated by any data sets that confirm the presence and similarity of the effect across multiple continents. Evidence of a rapid TPW oscillation in Antarctica can be correlated with other samples from the North American continent currently under study to provide evidence for the theory of global, short-timescale TPW.

  16. Development of solid phase adsorption toxin tracking (SPATT) for monitoring anatoxin-a and homoanatoxin-a in river water.

    PubMed

    Wood, Susanna A; Holland, Patrick T; MacKenzie, Lincoln

    2011-02-01

    Sampling and monitoring for cyanotoxins can be problematic as concentrations change with environmental and hydrological conditions. Current sampling practices (e.g. grab samples) provide data on cyanotoxins present only at one point in time and may miss areas or times of highest risk. Recent research has identified the widespread distribution of anatoxin-producing benthic cyanobacteria in rivers highlighting the need for development of effective sampling techniques. In this study we evaluated the potential of an in situ method known as solid phase adsorption toxin tracking (SPATT) for collecting and concentrating anatoxin-a (ATX) and homoanatoxin-a (HTX) in river water. Fifteen different adsorption substrates were screened for efficiency of ATX uptake, nine of which retained high proportions (>70%) of ATX. Four substrates were then selected for a 24-h trial in a SPATT bag format in the laboratory. The greatest decrease in ATX in the water was observed with powdered activated carbon (PAC) and Strata-X (a polymeric resin) SPATT bags. A 3-d field study in a river containing toxic benthic cyanobacterial mats was undertaken using PAC and Strata-X SPATT bags. ATX and HTX were detected in all SPATT bags. Surface grab samples were taken throughout the field study and ATX and HTX were only detected in one of the water samples, highlighting the limitations of this currently used method. Both Strata-X and PAC were found to be effective absorbent substrates. PAC has the advantage that it is cheap and readily available and appears to continue to sorb toxins over longer periods than Strata-X. SPATT has the potential to be integrated into current cyanobacterial monitoring programmes and would be a very useful and economical tool for early warning of ATX and HTX contamination in water. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Observations of radiation fog chemistry in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Straub, D.; Hutchings, J.; Herckes, P.

    2010-07-01

    The chemical composition of radiation fog in the Mid-Atlantic region of the United States has been the focus of an ongoing field campaign based in Selinsgrove, PA. This field study was established to provide a long term record that can be used to identify the effects of meteorology and air mass source regions on fog composition and to shed light on the role that fog can play in the production of secondary inorganic and organic aerosol mass. In the United States, studies that focus on radiation fog have been relatively rare. For the most part, they have been limited geographically to the Central Valley of California, though individual studies have also been conducted in the Central United States and along the Texas-Louisiana Gulf Coast. Sample collection for the current study began during the fall of 2007. Through 2009, samples from 25 radiation fog events have been obtained. A Caltech Heated Rod Cloudwater Collector (CHRCC) having a Dp50 of approximately 8 microns was used to collect one fog sample per event. Samples were typically collected between 2:00 AM and 7:00 AM under conditions of light winds, clear skies, and recent rainfall. Sample volumes ranged from 2.9 ml to 150 ml. Following collection, samples were analyzed for pH and then one of the following: major inorganic ions, dissolved total organic carbon, N-nitrosodimethylamine (NDMA), metals, or organic speciation. Through 2009, sample pH varied between 4.28 and 6.86 and averaged 5.03 based on H+ concentration. Ammonium and sulfate were found to be the most abundant ionic species in the fog samples. Sufficient ammonium was detected in nearly every sample to fully neutralize nitrate and sulfate. The concentrations of sulfate, nitrate, and ammonium observed in this study were lower than values reported in the literature for most other cloud and fog studies conducted in the US. Due to significant ammonium input, pH in the current study was higher than most other studies. Concentrations of total organic carbon averaged 7.22 mgC/L, which is lower than other radiation fogs studies but similar to that for many cloud studies. NDMA concentrations in two analyzed samples were considered high, but not outside the range that could be expected through equilibrium with potential gas phase concentrations.

  18. Preparation and Thermal Characterization of Annealed Gold Coated Porous Silicon.

    PubMed

    Behzad, Kasra; Mat Yunus, Wan Mahmood; Talib, Zainal Abidin; Zakaria, Azmi; Bahrami, Afarin

    2012-01-16

    Porous silicon (PSi) layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm² fixed current density for different etching times. The samples were coated with a 50-60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron microscopy (SEM). Photoacoustic spectroscopy (PAS) measurements were carried out to measure the thermal diffusivity (TD) of the PSi and Au/PSi samples. For the Au/PSi samples, the thermal diffusivity was measured before and after annealing to study the effect of annealing. Also to study the aging effect, a comparison was made between freshly annealed samples and samples 30 days after annealing.

  19. Experiments on transient melting of tungsten by ELMs in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Krieger, K.; Balden, M.; Coenen, J. W.; Laggner, F.; Matthews, G. F.; Nille, D.; Rohde, V.; Sieglin, B.; Giannone, L.; Göths, B.; Herrmann, A.; de Marne, P.; Pitts, R. A.; Potzel, S.; Vondracek, P.; ASDEX-Upgrade Team; EUROfusion MST1 Team

    2018-02-01

    Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the divertor manipulator II (DIM-II) system (Herrmann et al 2015 Fusion Eng. Des. 98-9 1496-9). Designed as near replicas of the geometries used also in separate experiments on the JET tokamak (Coenen et al 2015 J. Nucl. Mater. 463 78-84 Coenen et al 2015 Nucl. Fusion 55 023010; Matthews et al 2016 Phys. Scr. T167 7), the samples featured a misaligned leading edge and a sloped ridge respectively. Both structures protrude above the default target plate surface thus receiving an increased fraction of the parallel power flux. Transient melting by ELMs was induced by moving the outer strike point to the sample location. The temporal evolution of the measured current flow from the samples to vessel potential confirmed transient melting. Current magnitude and dependency from surface temperature provided strong evidence for thermionic electron emission as main origin of the replacement current driving the melt motion. The different melt patterns observed after exposures at the two sample geometries support the thermionic electron emission model used in the MEMOS melt motion code, which assumes a strong decrease of the thermionic net current at shallow magnetic field to surface angles (Pitts et al 2017 Nucl. Mater. Energy 12 60-74). Post exposure ex situ analysis of the retrieved samples show recrystallization of tungsten at the exposed surface areas to a depth of up to several mm. The melt layer transport to less exposed surface areas leads to ratcheting pile up of re-solidified debris with zonal growth extending from the already enlarged grains at the surface.

  20. Antidepressant Use and Lifetime History of Mental Disorders in a Community Sample: Results from the Baltimore Epidemiologic Catchment Area Study

    PubMed Central

    Takayanagi, Yoichiro; Spira, Adam P.; Bienvenu, O. Joseph; Hock, Rebecca S.; Carras, Michelle C.; Eaton, William W.; Mojtabai, Ramin

    2015-01-01

    Objectives Past studies have shown that many individuals who use antidepressants do not have a current or lifetime history of mental disorders. However, recent studies suggest that the one-time retrospective evaluation of mental disorders commonly used in such studies may substantially underestimate the true lifetime prevalence of mental disorders. We examined the prevalence of mental disorders, assessed prospectively over multiple interviews, among individuals currently using antidepressants in a community sample. Methods Using data from the Baltimore Epidemiologic Catchment Area (ECA) Survey Wave 1 (1981) through Wave 4 (2004) (N = 1071), we assessed lifetime prevalence of common mood and anxiety disorders according to the DSM-III and DSM-III-R criteria, based on 4 interviews, among participants who reported current antidepressant use. Furthermore, we examined factors associated with current antidepressant use. Results Thirteen percent of participants at Wave 4 reported currently using antidepressant medications. Among antidepressant users, 69% never met criteria for major depressive disorder (MDD), and 38% never met criteria for MDD, obsessive-compulsive disorder, panic disorder, social phobia, or generalized anxiety disorder in their lifetime. Female gender, Caucasian ethnicity, recent or current physical problems (e.g., loss of bladder control, hypertension and back pain) and recent mental health facility visits were associated with antidepressant use in addition to mental disorders. Conclusions Many individuals who are prescribed and use antidepressant medications may not have met criteria for mental disorders. Our data indicate that antidepressants are commonly used in the absence of clear evidence-based indications. PMID:25188822

  1. Characteristics of edge breakdowns on Teflon samples

    NASA Technical Reports Server (NTRS)

    Yadlowsky, E. J.; Hazelton, R. C.; Churchill, R. J.

    1980-01-01

    The characteristics of electrical discharges induced on silverbacked Teflon samples irradiated by a monoenergetic electron beam have been studied under controlled laboratory conditions. Measurements of breakdown threshold voltages indicate a marked anisotropy in the electrical breakdown properties of Teflon: differences of up to 10 kV in breakdown threshold voltage are observed depending on the sample orientation. The material anisotropy can be utilized in spacecraft construction to reduce the magnitude of discharge currents.

  2. Friction Stir Processing of Stainless Steel for Ascertaining Its Superlative Performance in Bioimplant Applications.

    PubMed

    Perumal, G; Ayyagari, A; Chakrabarti, A; Kannan, D; Pati, S; Grewal, H S; Mukherjee, S; Singh, S; Arora, H S

    2017-10-25

    Substrate-cell interactions for a bioimplant are driven by substrate's surface characteristics. In addition, the performance of an implant and resistance to degradation are primarily governed by its surface properties. A bioimplant typically degrades by wear and corrosion in the physiological environment, resulting in metallosis. Surface engineering strategies for limiting degradation of implants and enhancing their performance may reduce or eliminate the need for implant removal surgeries and the associated cost. In the current study, we tailored the surface properties of stainless steel using submerged friction stir processing (FSP), a severe plastic deformation technique. FSP resulted in significant microstructural refinement from 22 μm grain size for the as-received alloy to 0.8 μm grain size for the processed sample with increase in hardness by nearly 1.5 times. The wear and corrosion behavior of the processed alloy was evaluated in simulated body fluid. The processed sample demonstrated remarkable improvement in both wear and corrosion resistance, which is explained by surface strengthening and formation of a highly stable passive layer. The methylthiazol tetrazolium assay demonstrated that the processed sample is better in supporting cell attachment, proliferation with minimal toxicity, and hemolysis. The athrombogenic characteristic of the as-received and processed samples was evaluated by fibrinogen adsorption and platelet adhesion via the enzyme-linked immunosorbent assay and lactate dehydrogenase assay, respectively. The processed sample showed less platelet and fibrinogen adhesion compared with the as-received alloy, signifying its high thromboresistance. The current study suggests friction stir processing to be a versatile toolbox for enhancing the performance and reliability of currently used bioimplant materials.

  3. Mutual Inductance Problem for a System Consisting of a Current Sheet and a Thin Metal Plate

    NASA Technical Reports Server (NTRS)

    Fulton, J. P.; Wincheski, B.; Nath, S.; Namkung, M.

    1993-01-01

    Rapid inspection of aircraft structures for flaws is of vital importance to the commercial and defense aircraft industry. In particular, inspecting thin aluminum structures for flaws is the focus of a large scale R&D effort in the nondestructive evaluation (NDE) community. Traditional eddy current methods used today are effective, but require long inspection times. New electromagnetic techniques which monitor the normal component of the magnetic field above a sample due to a sheet of current as the excitation, seem to be promising. This paper is an attempt to understand and analyze the magnetic field distribution due to a current sheet above an aluminum test sample. A simple theoretical model, coupled with a two dimensional finite element model (FEM) and experimental data will be presented in the next few sections. A current sheet above a conducting sample generates eddy currents in the material, while a sensor above the current sheet or in between the two plates monitors the normal component of the magnetic field. A rivet or a surface flaw near a rivet in an aircraft aluminum skin will disturb the magnetic field, which is imaged by the sensor. Initial results showed a strong dependence of the flaw induced normal magnetic field strength on the thickness and conductivity of the current-sheet that could not be accounted for by skin depth attenuation alone. It was believed that the eddy current imaging method explained the dependence of the thickness and conductivity of the flaw induced normal magnetic field. Further investigation, suggested the complexity associated with the mutual inductance of the system needed to be studied. The next section gives an analytical model to better understand the phenomenon.

  4. The zoonotic potential of Giardia intestinalis assemblage E in rural settings.

    PubMed

    Abdel-Moein, Khaled A; Saeed, Hossam

    2016-08-01

    Giardiasis is a globally re-emerging protozoan disease with veterinary and public health implications. The current study was carried out to investigate the zoonotic potential of livestock-specific assemblage E in rural settings. For this purpose, a total of 40 microscopically positive Giardia stool samples from children with gastrointestinal complaints with or without diarrhea were enrolled in the study as well as fecal samples from 46 diarrheic cattle (18 dairy cows and 28 calves). Animal samples were examined by sedimentation method to identify Giardia spp., and then, all Giardia positive samples from human and animals were processed for molecular detection of livestock-specific assemblage E through amplification of assemblage-specific triosephosphate isomerase (tpi) gene using nested polymerase chain reaction (PCR). The results of the study revealed high unexpected occurrence of assemblage E among human samples (62.5 %), whereas the distribution among patients with diarrhea and those without was 42.1 and 81 %, respectively. On the other hand, the prevalence of Giardia spp. among diarrheic dairy cattle was (8.7 %), while only calves yielded positive results (14.3 %) and all bovine Giardia spp. were genetically classified as Giardia intestinalis assemblage E. Moreover, DNA sequencing of randomly selected one positive human sample and another bovine one revealed 100 and 99 % identity with assemblage E tpi gene sequences available at GenBank after BLAST analysis. In conclusion, the current study highlights the wide dissemination of livestock-specific assemblage E among humans in rural areas, and thus, zoonotic transmission cycle should not be discounted during the control of giardiasis in such settings.

  5. Method and apparatus for generating motor current spectra to enhance motor system fault detection

    DOEpatents

    Linehan, Daniel J.; Bunch, Stanley L.; Lyster, Carl T.

    1995-01-01

    A method and circuitry for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed.

  6. Comparison of free flux flow in two single crystals of V3Si with slightly different pinning strengths

    NASA Astrophysics Data System (ADS)

    Gafarov, Ozarfar; Gapud, Albert A.; Moraes, Sunhee; Thompson, James R.; Christen, David K.; Reyes, Arneil P.

    2011-03-01

    Results of recent measurements on two very clean, single-crystal samples of the A15 superconductor V3 Si are presented. Magnetization and transport data confirm the ``clean'' quality of both samples, as manifested by: (i) high residual resistivity ratio, (ii) low critical current densities, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted in the slightly ``dirtier'' sample, which also has higher critical current density Jc (H). High-current Lorentz forces are applied on mixed-state vortices in order to induce the highly ordered free flux flow (FFF) phase, using the same methods as in previous work. A traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf (H), presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes core size into account, and predicts a deviation from BS. In this study, ρf (H) is confirmed to be consistent with predictions of KZ, as will be discussed. Funded by Research Corporation and the National Science Foundation.

  7. Free flux flow in two single crystals of V3Si with differing pinning strengths

    NASA Astrophysics Data System (ADS)

    Gafarov, O.; Gapud, A. A.; Moraes, S.; Thompson, J. R.; Christen, D. K.; Reyes, A. P.

    2011-10-01

    Results of measurements on two very clean, single-crystal samples of the A15 superconductor V3Si are presented. Magnetization and transport data have confirmed the ``clean'' quality of both samples, as manifested by: (i) high residual electrical resistivity ratio, (ii) very low critical current densities Jc, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted down for the slightly ``dirtier'' sample, which consequently also has higher critical current density Jc(H). Large Lorentz forces are applied on mixed-state vortices via large currents, in order to induce the highly ordered free flux flow (FFF) phase, using experimental methods developed previously. The traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf(H) ˜ H/Hc2, presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes into account the effects of magnetic field on core size, and predict a clear deviation from the linear BS dependence. In this study, ρf(H) is confirmed to be consistent with predictions of KZ.

  8. Meta-Storms: efficient search for similar microbial communities based on a novel indexing scheme and similarity score for metagenomic data.

    PubMed

    Su, Xiaoquan; Xu, Jian; Ning, Kang

    2012-10-01

    It has long been intriguing scientists to effectively compare different microbial communities (also referred as 'metagenomic samples' here) in a large scale: given a set of unknown samples, find similar metagenomic samples from a large repository and examine how similar these samples are. With the current metagenomic samples accumulated, it is possible to build a database of metagenomic samples of interests. Any metagenomic samples could then be searched against this database to find the most similar metagenomic sample(s). However, on one hand, current databases with a large number of metagenomic samples mostly serve as data repositories that offer few functionalities for analysis; and on the other hand, methods to measure the similarity of metagenomic data work well only for small set of samples by pairwise comparison. It is not yet clear, how to efficiently search for metagenomic samples against a large metagenomic database. In this study, we have proposed a novel method, Meta-Storms, that could systematically and efficiently organize and search metagenomic data. It includes the following components: (i) creating a database of metagenomic samples based on their taxonomical annotations, (ii) efficient indexing of samples in the database based on a hierarchical taxonomy indexing strategy, (iii) searching for a metagenomic sample against the database by a fast scoring function based on quantitative phylogeny and (iv) managing database by index export, index import, data insertion, data deletion and database merging. We have collected more than 1300 metagenomic data from the public domain and in-house facilities, and tested the Meta-Storms method on these datasets. Our experimental results show that Meta-Storms is capable of database creation and effective searching for a large number of metagenomic samples, and it could achieve similar accuracies compared with the current popular significance testing-based methods. Meta-Storms method would serve as a suitable database management and search system to quickly identify similar metagenomic samples from a large pool of samples. ningkang@qibebt.ac.cn Supplementary data are available at Bioinformatics online.

  9. Planetary protection issues for sample return missions.

    PubMed

    DeVincenzi, D L; Klein, H P

    1989-01-01

    Sample return missions from a comet nucleus and the Mars surface are currently under study in the US, USSR, and by ESA. Guidance on Planetary Protection (PP) issues is needed by mission scientists and engineers for incorporation into various elements of mission design studies. Although COSPAR has promulgated international policy on PP for various classes of solar system exploration missions, the applicability of this policy to sample return missions, in particular, remains vague. In this paper, we propose a set of implementing procedures to maintain the scientific integrity of these samples. We also propose that these same procedures will automatically assure that COSPAR-derived PP guidelines are achieved. The recommendations discussed here are the first step toward development of official COSPAR implementation requirements for sample return missions.

  10. ENVIRONMENTAL SAMPLING: A BRIEF REVIEW

    EPA Science Inventory

    Proper application of statistical principles at the outset of an environmental study can make the difference between an effective, efficient study and wasted resources. This review distills some of the thoughts current among environmental scientists from a variety of backgrounds ...

  11. Analysis of the sensitivity of in vitro bioassays for androgenic, progestagenic, glucocorticoid, thyroid and estrogenic activity: Suitability for drinking and environmental waters.

    PubMed

    Leusch, Frederic D L; Neale, Peta A; Hebert, Armelle; Scheurer, Marco; Schriks, Merijn C M

    2017-02-01

    The presence of endocrine disrupting chemicals in the aquatic environment poses a risk for ecosystem health. Consequently there is a need for sensitive tools, such as in vitro bioassays, to monitor endocrine activity in environmental waters. The aim of the current study was to assess whether current in vitro bioassays are suitable to detect endocrine activity in a range of water types. The reviewed assays included androgenic (n=11), progestagenic (n=6), glucocorticoid (n=5), thyroid (n=5) and estrogenic (n=8) activity in both agonist and antagonist mode. Existing in vitro bioassay data were re-evaluated to determine assay sensitivity, with the calculated method detection limit compared with measured hormonal activity in treated wastewater, surface water and drinking water to quantify whether the studied assays were sufficiently sensitive for environmental samples. With typical sample enrichment, current in vitro bioassays are sufficiently sensitive to detect androgenic activity in treated wastewater and surface water, with anti-androgenic activity able to be detected in most environmental waters. Similarly, with sufficient enrichment, the studied mammalian assays are able to detect estrogenic activity even in drinking water samples. Fewer studies have focused on progestagenic and glucocorticoid activity, but some of the reviewed bioassays are suitable for detecting activity in treated wastewater and surface water. Even less is known about (anti)thyroid activity, but the available data suggests that the more sensitive reviewed bioassays are still unlikely to detect this type of activity in environmental waters. The findings of this review can help provide guidance on in vitro bioassay selection and required sample enrichment for optimised detection of endocrine activity in environmental waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A study of tablet dissolution by magnetic resonance electric current density imaging.

    PubMed

    Mikac, Ursa; Demsar, Alojz; Demsar, Franci; Sersa, Igor

    2007-03-01

    The electric current density imaging technique (CDI) was used to monitor the dissolution of ion releasing tablets (made of various carboxylic acids and of sodium chloride) by following conductivity changes in an agar-agar gel surrounding the tablet. Conductivity changes in the sample were used to calculate spatial and temporal changes of ionic concentrations in the sample. The experimental data for ion migration were compared to a mathematical model based on a solution of the diffusion equation with moving boundary conditions for the tablet geometry. Diffusion constants for different acids were determined by fitting the model to the experimental data. The experiments with dissolving tablets were used to demonstrate the potential of the CDI technique for measurement of ion concentration in the vicinity of ion releasing samples.

  13. STARDUST and HAYABUSA: Sample Return Missions to Small Bodies in the Solar System

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.

    2005-01-01

    There are currently two active spacecraft missions designed to return samples to Earth from small bodies in our Solar System. STARDUST will return samples from the comet Wild 2, and HAYABUSA will return samples from the asteroid Itokawa. On January 3,2004, the STARDUST spacecraft made the closest ever flyby (236 km) of the nucleus of a comet - Comet Wild 2. During the flyby the spacecraft collected samples of dust from the coma of the comet. These samples will be returned to Earth on January 15,2006. After a brief preliminary examination to establish the nature of the returned samples, they will be made available to the general scientific community for study. The HAYABUSA spacecraft arrived at the Near Earth Asteroid Itokawa in September 2005 and is currently involved in taking remote sensing data from the asteroid. Several practice landings have been made and a sample collection landing will be made soon. The collected sample will be returned to Earth in June 2007. During my talk I will discuss the scientific goals of the STARDUST and HAYABUSA missions and provide an overview of their designs and flights to date. I will also show some of the exciting data returned by these spacecraft during their encounters with their target objects.

  14. Comparison of a standardized procedure with current laboratory practices for the detection of lupus anticoagulant in France. Working Group on Hemostasis of the Société Française de Biologie Clinique.

    PubMed

    1993-11-15

    A multicenter study involving 13 laboratories was designed to compare a common procedure for screening lupus anticoagulants (LA) to the different practices currently in use in these laboratories. The common procedure combined 3 phospholipid-dependent assays, including mixing studies and a phospholipid neutralizing test. Due to the heterogeneity of LA expression, an abnormal result in at least one of the tests was sufficient to classify a sample as positive for LA. Consecutive samples referred for LA diagnosis were evaluated in parallel by each participant and the data found using the common procedure were analyzed independently according to mutually agreed cut-offs and criteria for sample classification. Within a period of 3 months, 535 samples were included, of which 147 were judged LA positive, 29 undetermined and 359 negative by the respective laboratories using their current practice. When using the common procedure, 149 plasmas were said to be positive, 38 undetermined and 348 negative. Absolute concordance occurred for 81% of the specimen population and absolute discordance (positive versus negative) for 7%. The level of agreement between the common procedure and the current practices, assessed by kappa indexes, indicated noticeable variations in the rates of detection from laboratory to laboratory. Among the different tests used in the common procedure, regular APTT was the least sensitive (about 50% detection) but none of the other tests alone recognized more than 73% of specimens from the LA positive population. This yield increased to about 90% with any combination of 2 sensitive tests.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Experimental Study of Arcing on High-voltage Solar Arrays

    NASA Technical Reports Server (NTRS)

    Vayner, Boris; Galofaro, Joel; Ferguson, Dale

    2005-01-01

    The main obstacle to the implementation of a high-voltage solar array in space is arcing on the conductor-dielectric junctions exposed to the surrounding plasma. One obvious solution to this problem would be the installation of fully encapsulated solar arrays which were not having exposed conductors at all. However, there are many technological difficulties that must be overcome before the employment of fully encapsulated arrays will turn into reality. An alternative solution to raise arc threshold by modifications of conventionally designed solar arrays looks more appealing, at least in the nearest future. A comprehensive study of arc inception mechanism [1-4] suggests that such modifications can be done in the following directions: i) to insulate conductor-dielectric junction from a plasma environment (wrapthrough interconnects); ii) to change a coverglass geometry (overhang); iii) to increase a coverglass thickness; iiii) to outgas areas of conductor-dielectric junctions. The operation of high-voltage array in LEO produces also the parasitic current power drain on the electrical system. Moreover, the current collected from space plasma by solar arrays determines the spacecraft floating potential that is very important for the design of spacecraft and its scientific apparatus. In order to verify the validity of suggested modifications and to measure current collection five different solar array samples have been tested in large vacuum chamber. Each sample (36 silicon based cells) consists of three strings containing 12 cells connected in series. Thus, arc rate and current collection can be measured on every string independently, or on a whole sample when strings are connected in parallel. The heater installed in the chamber provides the possibility to test samples under temperature as high as 80 C that simulates the LEO operational temperature. The experimental setup is described below.

  16. Experimental Study of Arcing on High-Voltage Solar Arrays

    NASA Technical Reports Server (NTRS)

    Vayner, Boris; Galofaro, Joel; Ferguson, Dale

    2003-01-01

    The main obstacle to the implementation of a high-voltage solar array in space is arcing on the conductor-dielectric junctions exposed to the surrounding plasma. One obvious solution to this problem would be the installation of fully encapsulated solar arrays which were not having exposed conductors at all. However, there are many technological difficulties that must be overcome before the employment of fully encapsulated arrays will turn into reality. An alternative solution to raise arc threshold by modifications of conventionally designed solar arrays looks more appealing, at least in the nearest future. A comprehensive study of arc inception mechanism suggests that such modifications can be done in the following directions: 1) To insulate conductor-dielectric junction from a plasma environment (wrapthrough interconnects); 2) To change a coverglass geometry (overhang); 3) To increase a coverglass thickness; 4) To outgas areas of conductor-dielectric junctions. The operation of high-voltage array in LEO produces also the parasitic current power drain on the electrical system. Moreover, the current collected from space plasma by solar arrays determines the spacecraft floating potential that is very important for the design of spacecraft and its scientific apparatus. In order to verify the validity of suggested modifications and to measure current collection five different solar array samples have been tested in a large vacuum chamber. Each sample (36 silicon based cells) consists of three strings containing 12 cells connected in series. Thus, arc rate and current collection can be measured on every string independently, or on a whole sample when strings are connected in parallel. The heater installed in the chamber provides the possibility to test samples under temperature as high as 80 C that stimulates the LEO operational temperature. The experimental setup is described below.

  17. Comparative study of some commercial samples of naga bhasma.

    PubMed

    Wadekar, Mrudula; Gogte, Viswas; Khandagale, Prasad; Prabhune, Asmita

    2004-04-01

    Naga bhasma is one of those reputed ayurvedic bhasmas which are claimed to possess some extraordinary medical properties. However, identification of a genuine sample of naga bhasma is a challenging problem. Because at present naga bhasma is manufactured by different ayurvedic pharmacies, by following different methods, these products are not standardised either from chemical and structural point of view. Therefore, comparative study of these samples using modern analytical techniques is important and necessary to understand their current status. In this communication, such study of naga bhasma from chemical and structural point of view is reported by using XRD, IR and UV spectroscopy and thermogravimetry.

  18. Financing Adult Education: How Adequate Are Current Sources in Facilitating Access and Participation in Centres in Murang'a South Sub-County, Murang'a County, Kenya?

    ERIC Educational Resources Information Center

    Maina, Ndonga James; Orodho, John Aluko

    2016-01-01

    The thrust of this study was to examine the level of adequacy of current sources in facilitating access and participation in adult education centres in Murang'a South Sub-County, Murang'a County, Kenya. The study adopted the descriptive survey design. Combinations of purposive and stratified random sampling techniques were used to select 82…

  19. The Current Use of Web 2.0 Tools in University Teaching from the Perspective of Faculty Members at the College of Education

    ERIC Educational Resources Information Center

    Ahmed, Abdelrahman M.; AbdelAlmuniem, Arwa; Almabhouh, Ahmed A.

    2016-01-01

    This study aimed to identify the current status of using Web 2.0 tools in university teaching by the faculty members of the College of Education at Sudan University of Science and Technology. The study used a descriptive analytical method based on the use of questionnaires and interviews. The questionnaire was administered to a sample of 40…

  20. Is News Media Related to Civic Engagement? The Effects of Interest in and Discussions about the News Media on Current and Future Civic Engagement of Adolescents

    ERIC Educational Resources Information Center

    Erentaite, Rasa; Zukauskiene, Rita; Beyers, Wim; Pilkauskaite-Valickiene, Rasa

    2012-01-01

    This study explored whether discussions about the media, when positively linked to interest in the news media, were related to adolescents' current and future civic engagement. A sample of 2638 adolescents (age M = 17, SD = 1.2), who participated in a school-based study on positive socialization, completed self-report measures on interest in the…

  1. Teaching Assessment for Teacher Human Capital Management: Learning from the Current State of the Art. WCER Working Paper No. 2011-2

    ERIC Educational Resources Information Center

    Milanowski, Anthony T.; Heneman, Herbert G., III; Kimball, Steven M.

    2011-01-01

    This paper reports on a study of the current state of the art in teaching assessment. The major goal of the study was to examine a sample of assessment systems and then develop a specification for a state-of the art performance assessment system to be used for human capital management functions. The authors hope was that this specification would…

  2. Pre-Service Science Teachers' Perception of the Principles of Scientific Research

    ERIC Educational Resources Information Center

    Can, Sendil; Kaymakci, Güliz

    2016-01-01

    The purpose of the current study employing the survey method is to determine the pre-service science teachers' perceptions of the principles of scientific research and to investigate the effects of gender, grade level and the state of following scientific publications on their perceptions. The sampling of the current research is comprised of 125…

  3. A Citation Analysis of Who's Who in Introductory Textbooks

    ERIC Educational Resources Information Center

    Griggs, Richard A.; Proctor, Derrick L.

    2002-01-01

    Given the many changes in the introductory psychology textbook market in the past 2 decades and the lack of a recent citation study of introductory texts, we conducted a citation analysis of a stratified random sample of current texts. To provide a more comprehensive picture of current citation emphases, we extended our analysis to the top 60…

  4. The Effects of Adolescent Intimate Partner Violence on Women's Educational Attainment and Earnings

    ERIC Educational Resources Information Center

    Adams, Adrienne E.; Greeson, Megan R.; Kennedy, Angie C.; Tolman, Richard M.

    2013-01-01

    Intimate partner violence (IPV) is a serious, widespread problem that negatively affects women's lives, including their economic status. The current study explored whether the financial harm associated with IPV begins as early as adolescence. With longitudinal data from a sample of 498 women currently or formerly receiving welfare, we used latent…

  5. Psychiatric Comorbidities among Female Adolescents with Anorexia Nervosa

    ERIC Educational Resources Information Center

    Salbach-Andrae, Harriet; Lenz, Klaus; Simmendinger, Nicole; Klinkowski, Nora; Lehmkuhl, Ulrike; Pfeiffer, Ernst

    2008-01-01

    This study investigated current comorbid Axis I diagnoses associated with Anorexia Nervosa (AN) in adolescents. The sample included 101 female adolescents treated at a psychiatric unit for primary DSM-IV diagnoses of AN. 73.3% of the AN patients were diagnosed as having a current comorbidity of at least one comorbid Axis I diagnosis, with no…

  6. Assessing AD/HD in College Students: Psychometric Properties of the Barkley Self-Report Form

    ERIC Educational Resources Information Center

    Ladner, Jennifer M.; Schulenberg, Stefan E.; Smith, C. Veronica; Dunaway, Marcella H.

    2011-01-01

    The Barkley Current Symptoms Scale (BCSS)--Self-Report Form was designed to assess attention-deficit/hyperactivity disorder. The purpose of the current study was to add to BCSS psychometric literature in a sample of university students. Comparisons with normative data are provided, and implications for these findings are offered. (Contains 5…

  7. Profile of female sex workers in a Chinese county: Does it differ by where they came from and where they work?

    PubMed Central

    Fang, Xiaoyi; Li, Xiaoming; Yang, Hongmei; Hong, Yan; Zhao, Ran; Dong, Baiqing; Liu, Wei; Zhou, Yuejiao; Liang, Shaoling; Stanton, Bonita

    2007-01-01

    Since the 1980s, informal or clandestine sex work in the service or entertainment industry has spread from municipalities to small towns in most areas of China. Despite recognition of the important role of female sex workers in HIV and STD epidemics in China, limited data are available regarding their individual characteristics and social and environmental context of their work. Furthermore, most existing studies on commercial sex in China have been conducted in large cities or tourist attractions. Using data from 454 female sex workers in a rural Chinese county, the current study was designed to explore the individual profile of commercial sex workers and to examine whether the profile and sexual risk behavior differ by where the female sex workers came from and where they work. The sample in the current study was different from previous studies in a number of key individual characteristics. However, similar to previous studies, the sample in the current study were driven into commercial sex by poverty or limited employment opportunities, lived in a stressful life, were subject to sexual harassment and related violence, and engaged in a number of health-compromising behaviors including behaviors that put them at risk of HIV/STD infection and depression. The findings of the current study underscore the urgent needs for effective HIV/STD prevention intervention and mental health promotion program among female sex workers in China. The data in the current study suggest a strong association of individual profile with the economic conditions of work sites and residence status (in-province residency versus out-province residence) which suggests that such efforts must take the social and cultural contextual factors of their working environment (and sexual risks) into consideration. PMID:18270499

  8. Contact resistance and normal zone formation in coated yttrium barium copper oxide superconductors

    NASA Astrophysics Data System (ADS)

    Duckworth, Robert Calvin

    2001-11-01

    This project presents a systematic study of contact resistance and normal zone formation in silver coated YBa2CU3Ox (YBCO) superconductors. A unique opportunity exists in YBCO superconductors because of the ability to use oxygen annealing to influence the interfacial properties and the planar geometry of this type of superconductor to characterize the contact resistance between the silver and YBCO. The interface represents a region that current must cross when normal zones form in the superconductor and a high contact resistance could impede the current transfer or produce excess Joule heating that would result in premature quench or damage of the sample. While it has been shown in single-crystalline YBCO processing methods that the contact resistance of the silver/YBCO interface can be influenced by post-process oxygen annealing, this has not previously been confirmed for high-density films, nor for samples with complete layers of silver deposited on top of the YBCO. Both the influence of contact resistance and the knowledge of normal zone formation on conductor sized samples is essential for their successful implementation into superconducting applications such as transmission lines and magnets. While normal zone formation and propagation have been studied in other high temperature superconductors, the amount of information with respect to YBCO has been very limited. This study establishes that the processing method for the YBCO does not affect the contact resistance and mirrors the dependence of contact resistance on oxygen annealing temperature observed in earlier work. It has also been experimentally confirmed that the current transfer length provides an effective representation of the contact resistance when compared to more direct measurements using the traditional four-wire method. Finally for samples with low contact resistance, a combination of experiments and modeling demonstrate an accurate understanding of the key role of silver thickness and substrate thickness on the stability of silver-coated YBCO Rolling Assisted Bi-Axially Textured Substrates conductors. Both the experimental measurements and the one-dimensional model show that increasing the silver thickness results in an increased thermal runaway current; that is, the current above which normal zones continue to grow due to insufficient local cooling.

  9. Historic and current hepatitis B viral DNA and quantitative HBsAg level are not associated with cirrhosis in non-Asian women with chronic hepatitis B.

    PubMed

    Harkisoen, S; Arends, J E; van den Hoek, J A R; Whelan, J; van Erpecum, K J; Boland, G J; Hoepelman, A I M

    2014-12-01

    Some studies done in Asian patients have shown that serum levels of hepatitis B virus (HBV) DNA predict the development of cirrhosis. However, it is unclear whether this also applies for non-Asian patients. This study investigated historic and current HBV DNA and quantitative hepatitis B surface antigen (HBsAg) levels as predictors of cirrhosis in non-Asian women with chronic HBV. A retrospective cohort study of non-Asian women with chronic HBV was performed. Among other variables, HBV DNA and quantitative HBsAg levels were measured in stored historic serum samples obtained during pregnancy (period 1990-2004) and current serum samples (period 2011-2012) to determine any association with liver cirrhosis by liver stiffness measurement (LSM). One hundred and nineteen asymptomatic, treatment-naïve non-Asian women were included; the median number of years between the historic sample and the current sample was 17 (interquartile range (IQR) 13-20). The median historic log HBV DNA and quantitative log HBsAg levels were 2.5 (IQR 1.9-3.4) IU/ml and 4.2 (IQR 3.6-4.5) IU/ml, respectively. LSM diagnosed 14 patients (12%) with F3-F4 fibrosis, i.e. stiffness >8.1kPa. No association of cirrhosis was found with historic HBV DNA (relative risk (RR) 0.34, 95% confidence interval (CI) 0.05-2.44) or with the quantitative HBsAg level (HBsAg level >1000 IU/ml, RR 0.35, 95% CI 0.11-1.11). Multivariable analysis identified alcohol consumption (odds ratio (OR) 6.4, 95% CI 1.3-30.1), aspartate aminotransferase >0.5 times the upper limit of normal (OR 15.4, 95% CI 1.9-122.6), and prothrombin time (OR 12.0, 95% CI 1.2-120.4), but not HBV DNA or quantitative HBsAg level, to be independent predictors of the presence of cirrhosis. Neither historic nor current HBV DNA or the quantitative HBsAg level is associated with the development of HBV-related cirrhosis in non-Asian women. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States

    PubMed Central

    Steimer, Andreas; Schindler, Kaspar

    2015-01-01

    Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon’s implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike’s preceding ISI. As we show, the EIF’s exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron’s ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational theories about UP states during slow wave sleep and present possible extensions of the model in the context of spike-frequency adaptation. PMID:26203657

  11. A Further Assessment of Momentary Time-Sampling across Extended Interval Lengths

    ERIC Educational Resources Information Center

    Alvero, Alicia M.; Rappaport, Eva; Taylor, Matthew A.

    2011-01-01

    The current study compared the estimation of momentary time-sampling (MTS) to actual safety performance of three ergonomic responses: back, shoulder, and feet. Actual safety performance was established for the five participants by measuring the target responses with a continuous procedure. MTS 90, 105, 120, 135, 150, 165, 180, 195, 210, 240, and…

  12. Adolescent Criminal Acts Committed and Substance Use with a Voluntary Sample Recruited from Post-Secondary Institutions

    ERIC Educational Resources Information Center

    Collette, Tessa; Pakzad, Sarah; Bergheul, Saïd

    2015-01-01

    The current study focuses on exploring the relationships between various patterns of criminal acts committed, drug use, alcohol consumption, and adult personality traits in a sample with a low probability of life course persistent criminal behaviors. A retrospective questionnaire and the NEO-FFI (Five Factor Inventory) were administered to a…

  13. Validity of the WISC-IV Spanish for a Clinically Referred Sample of Hispanic Children

    ERIC Educational Resources Information Center

    San Miguel Montes, Liza E.; Allen, Daniel N.; Puente, Antonio E.; Neblina, Cris

    2010-01-01

    The Wechsler Intelligence Scale for Children (WISC) is the most commonly used intelligence test for children. Five years ago, a Spanish version of the WISC-IV was published (WISC-IV Spanish; Wechsler, 2005), but a limited amount of published information is available regarding its utility when assessing clinical samples. The current study included…

  14. The Value of a College Degree for Foster Care Alumni: Comparisons with General Population Samples

    ERIC Educational Resources Information Center

    Salazar, Amy M.

    2013-01-01

    Higher education is associated with substantial adult life benefits, including higher income and improved quality of life, among others. The current study compared adult outcomes of 250 foster care alumni college graduates with two samples of general population graduates to explore the role higher education plays in these young adults' lives.…

  15. Binge Drinking and Rape: A Prospective Examination of College Women with a History of Previous Sexual Victimization

    ERIC Educational Resources Information Center

    McCauley, Jenna L.; Calhoun, Karen S.; Gidycz, Christine A.

    2010-01-01

    The current study prospectively examined the longitudinal relationships between binge drinking behavior and rape experiences among a multisite sample of college women with a history of prior attempted or completed rape (N = 228). Rates of binge drinking among this high-risk sample were high. Prospective analyses indicated that binge drinking…

  16. Using the Precaution Adoption Process Model to Describe a Disaster Preparedness Intervention among Low-Income Latinos

    ERIC Educational Resources Information Center

    Glik, Deborah C.; Eisenman, David P.; Zhou, Qiong; Tseng, Chi-Hong; Asch, Steven M.

    2014-01-01

    Only 40-50% of households in the United States are currently disaster prepared. In this intervention study, respondent-driven sampling was used to select a sample (n = 187) of low income, Latino residents of Los Angeles County, randomly assigned into two treatment conditions: (i) household preparedness education received through…

  17. The Structure of Problem Behavior in a Sample of Maltreated Youths

    ERIC Educational Resources Information Center

    Culhane, Sara E.; Taussig, Heather N.

    2009-01-01

    Studies of adolescent community samples suggest that substance use, risky sexual behavior, delinquency, and other problem behaviors can be explained in part by a single, underlying factor or syndrome. Of current interest is the generalizability of these findings to subgroups or special populations of youths who may be at high risk for problem…

  18. Use and Perception of Technology: Sex and Generational Differences in a Community Sample

    ERIC Educational Resources Information Center

    Van Volkom, Michele; Stapley, Janice C.; Malter, Johnna

    2013-01-01

    A community sample of 431 adults (175 men and 256 women) ages 18 to 91 across three generations (young adults, adults, and older adults) were recruited for the current study. Participants completed a demographic and technology use questionnaire that ascertained their attitudes toward, and use of, various types of technology--such as cellular…

  19. Detection of viable Cyptosporidium parvum in soil by reverse transcription real time PCR targeting hsp70 mRNA

    EPA Science Inventory

    Extraction of high-quality mRNA from Cryptosporidium parvum is a key step in PCR detection of viable oocysts in environmental samples. Current methods for monitoring oocysts are limited to water samples; therefore, the goal of this study was to develop a rapid and sensitive proce...

  20. Random-effects linear modeling and sample size tables for two special crossover designs of average bioequivalence studies: the four-period, two-sequence, two-formulation and six-period, three-sequence, three-formulation designs.

    PubMed

    Diaz, Francisco J; Berg, Michel J; Krebill, Ron; Welty, Timothy; Gidal, Barry E; Alloway, Rita; Privitera, Michael

    2013-12-01

    Due to concern and debate in the epilepsy medical community and to the current interest of the US Food and Drug Administration (FDA) in revising approaches to the approval of generic drugs, the FDA is currently supporting ongoing bioequivalence studies of antiepileptic drugs, the EQUIGEN studies. During the design of these crossover studies, the researchers could not find commercial or non-commercial statistical software that quickly allowed computation of sample sizes for their designs, particularly software implementing the FDA requirement of using random-effects linear models for the analyses of bioequivalence studies. This article presents tables for sample-size evaluations of average bioequivalence studies based on the two crossover designs used in the EQUIGEN studies: the four-period, two-sequence, two-formulation design, and the six-period, three-sequence, three-formulation design. Sample-size computations assume that random-effects linear models are used in bioequivalence analyses with crossover designs. Random-effects linear models have been traditionally viewed by many pharmacologists and clinical researchers as just mathematical devices to analyze repeated-measures data. In contrast, a modern view of these models attributes an important mathematical role in theoretical formulations in personalized medicine to them, because these models not only have parameters that represent average patients, but also have parameters that represent individual patients. Moreover, the notation and language of random-effects linear models have evolved over the years. Thus, another goal of this article is to provide a presentation of the statistical modeling of data from bioequivalence studies that highlights the modern view of these models, with special emphasis on power analyses and sample-size computations.

  1. Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Coloado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino Counties, California

    USGS Publications Warehouse

    King, Harley D.; Chaffee, Maurice A.

    2000-01-01

    INTRODUCTION In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management's (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM's Coordinated Management Plan for the area. This report presents analytical data from this study. To provide comprehensive coverage of the NECD, we compiled and examined all available geochemical data, in digital form, from previous studies in the area, and made sample-site plots to aid in determining where sample-site coverage and analyses were sufficient, which samples should be re-analyzed, and where additional sampling was needed. Previous investigations conducted in parts of the current study area included the National Uranium Resource Evaluation (NURE) program studies of the Needles and Salton Sea 1? x 2? quadrangles; USGS studies of 12 BLM Wilderness Study Areas (WSAs) (Big Maria Mountains, Chemehuevi Mountains, Chuckwalla Mountains, Coxcomb Mountains, Mecca Hills, Orocopia Mountains, Palen-McCoy, Picacho Peak, Riverside Mountains, Sheephole Valley (also known as Sheep Hole/Cadiz), Turtle Mountains, and Whipple Mountains); and USGS studies in the Needles and El Centro 1? x 2? quadrangles done during the early 1990s as part of a project to identify the regional geochemistry of southern California. Areas where we did new sampling of rocks and stream sediments are mainly in the Chocolate Mountain Aerial Gunnery Range and in Joshua Tree National Park, which extends into the west-central part of the NECD, as shown in figure 1 and figure 2. This report contains analytical data for 132 rock samples and 1,245 stream-sediment samples collected by the USGS, and 362 stream-sediment samples and 189 soil samples collected during the NURE program. All samples are from the Northern and Eastern Colorado Desert BLM Resource Area and vicinity. Included in the 1,245 stream-sediment samples collected by the USGS are 284 samples collected as part of the current study, 817 samples collected as part of investigations of the12 BLM WSAs and re-analyzed for the present study, 45 samples from the Needles 1? X 2? quadrangle, and 99 samples from the El Centro 1? X 2? quadrangle. The NURE stream-sediment and soil samples were re-analyzed as part of the USGS study in the Needles quadrangle. Analytical data for samples from the Chocolate Mountain Aerial Gunnery Range, which is located within the area of the NECD, were previously reported (King and Chaffee, 1999a). For completeness, these results are also included in this report. Analytical data for samples from the area of Joshua Tree National Park that is within the NECD have also been reported (King and Chaffee, 1999b). These results are not included in this report. The analytical data presented here can be used for baseline geochemical, mineral resource, and environmental geochemical studies.

  2. Modeling the relationship between family home environment factors and parental health.

    PubMed

    Didericksen, Katharine Wickel; Berge, Jerica M

    2015-06-01

    Understanding parental health is an important part of understanding family health. Previous research suggests that family meals, familial relationship satisfaction, and family physical activity may separately be related to physical health. The current study aims to combine these variables into a structural equation model to determine the collective relationship they have with adult health within a sample of parents (n = 1,435). Most parents were married, White, and highly educated. The relationship between family meals and parental health was significant (β = -.07, t = -2.29, p < .05), with the full model having adequate fit and accounting for some of the overall variance in parental health. Familial relationship satisfaction and family physical activity were not found to be associated with parental health. Exploratory findings of the sample stratified by biological sex are described. Findings from the current study were consistent with a systemic perspective in that parents may have health benefits when they participate in family-level behavior (e.g., family meals). Additional areas for research and limitations to the current study are also discussed. (c) 2015 APA, all rights reserved).

  3. Using self-determination theory to describe the academic motivation of allied health professional-level college students.

    PubMed

    Ballmann, Jodi M; Mueller, Jill J

    2008-01-01

    This study investigated the various reasons that allied health students believe they are currently attending college. The Academic Motivation Scale was administered to a convenience sample of 222 upperclassmen and graduate-level students (162 women, 46 men). The Academic Motivation Scale proposes various reasons for continued engagement in academic pursuits that may be characteristic of personal and current reasons for persistence in a subject's particular academic program. The results showed that students portrayed themselves as currently attending college for both intrinsically and extrinsically motivated reasons. The most frequently endorsed motivational styles were identified (autonomous) extrinsic motivation and externally regulated (nonautonomous) extrinsic motivation. This study showed that this sample of professional-level college students was not completely self-determined in their end-stage academic pursuits. One conclusion that may be drawn from this study is that allied health programs that provide students with an educational context that supports self-determination may encourage future allied health professionals to develop the ability to support the self-determination of their future clients.

  4. Development of an abbreviated Career Indecision Profile-65 using item response theory: The CIP-Short.

    PubMed

    Xu, Hui; Tracey, Terence J G

    2017-03-01

    The current study developed an abbreviated version of the Career Indecision Profile-65 (CIP-65; Hacker, Carr, Abrams, & Brown, 2013) by using item response theory. In order to improve the efficiency of the CIP-65 in measuring career indecision, the individual item performance of the CIP-65 was examined with respect to the ordering of response occurrence and gender differential item functioning. The best 5 items of each scale of the CIP-65 (i.e., neuroticism/negative affectivity, choice/commitment anxiety, lack of readiness, and interpersonal conflicts) were retained in the CIP-Short using a sample of 588 college students. A validation sample (N = 174) supported the reliability and structural validity of the CIP-Short. The convergent and divergent validity of the CIP-Short was additionally supported in the findings of a hypothesized differential relational pattern in a separate sample (N = 360). While the current study supported the CIP-Short being a sound brief measure of career indecision, the limitations of this study and suggestions for future research were discussed as well. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Anophelism in a former malaria area of northeastern Spain.

    PubMed

    Bueno-Marí, Rubén; Jiménez-Peydró, Ricardo

    2013-01-01

    A field study on diversity and distribution of anophelines currently present in a past endemic malaria area of Spain was carried out in order to identify possible risk areas of local disease transmission. Multiple larval sites were sampled from June to October of 2011 in the Region of Somontano de Barbastro (Northeastern Spain). The sampling effort was fixed at 10 minutes which included the active search for larvae in each biotope visited. A total of 237 larval specimens belonging to four Anopheles species (Anopheles atroparvus, An. claviger, An. maculipennis and An. petragnani) were collected and identified. Malaria receptivity in the study area is high, especially in the area of Cinca river valley, due to the abundance of breeding sites of An. atroparvus very close to human settlements. Although current socio-economic conditions in Spain reduce possibilities of re-emergence of malaria transmission, it is evident that certain entomological and epidemiological vigilance must be maintained and even increased in the context of current processes of climate change and globalization.

  6. Anophelism in a Former Malaria Area of Northeastern Spain

    PubMed Central

    Bueno-Marí, Rubén; Jiménez-Peydró, Ricardo

    2013-01-01

    Background: A field study on diversity and distribution of anophelines currently present in a past endemic malaria area of Spain was carried out in order to identify possible risk areas of local disease transmission. Methods: Multiple larval sites were sampled from June to October of 2011 in the Region of Somontano de Barbastro (Northeastern Spain). The sampling effort was fixed at 10 minutes which included the active search for larvae in each biotope visited. Results: A total of 237 larval specimens belonging to four Anopheles species (Anopheles atroparvus, An. claviger, An. maculipennis and An. petragnani) were collected and identified. Conclusions: Malaria receptivity in the study area is high, especially in the area of Cinca river valley, due to the abundance of breeding sites of An. atroparvus very close to human settlements. Although current socio-economic conditions in Spain reduce possibilities of re-emergence of malaria transmission, it is evident that certain entomological and epidemiological vigilance must be maintained and even increased in the context of current processes of climate change and globalization. PMID:24409440

  7. The Effect of Sn Orientation on Intermetallic Compound Growth in Idealized Sn-Cu-Ag Interconnects

    NASA Astrophysics Data System (ADS)

    Kinney, Chris; Linares, Xioranny; Lee, Kyu-Oh; Morris, J. W.

    2013-04-01

    The work reported here explores the influence of crystal orientation on the growth of the interfacial intermetallic layer during electromigration in Cu||Sn||Cu solder joints. The samples were thin, planar Sn-Ag-Cu (SAC) solder layers between Cu bars subject to a uniaxial current. Electron backscatter diffraction (EBSD) was used to characterize the microstructure before and after testing. The most useful representation of the EBSD data identifies the Sn grain orientation by the angle between the Sn c-axis and the current direction. The tested samples included single-crystal joints with c-axis nearly parallel to the current ("green" samples) and with c-axis perpendicular to the current ("red" samples). At current density of 104 A/cm2 (steady-state temperature of ~150°C), an intermetallic layer grew at an observable rate in the "green" samples, but not in the "red" ones. A current density of 1.15 × 104 A/cm2 (temperature ~160°C) led to measurable intermetallic growth in both samples. The growth fronts were nearly planar and the growth rates constant (after an initial incubation period); the growth rates in the "green" samples were about 10× those in the "red" samples. The Cu concentrations were constant within the joints, showing that the intermetallic growth is dominated by the electromigration flux. The measured growth rates and literature values for the diffusion of Cu in Sn were used to extract values for the effective charge, z *, that governs the electromigration of Cu. The calculated value of z * is significantly larger for current perpendicular to the c-axis than along it.

  8. Self-injurious behaviours in children and adults with autism spectrum disorder (ASD).

    PubMed

    Gulsrud, A; Lin, C E; Park, M N; Hellemann, G; McCracken, J

    2018-04-25

    Self-injurious behaviours (SIB) are concerning, maladaptive behaviours that commonly occur in people with neurodevelopmental conditions and delays but seem to be particularly prevalent in children and adults with autism spectrum disorder (ASD). There has been increasing research examining the risk markers associated with the presence of SIB in people with ASD. Some of the factors associated with SIB have included cognitive abilities, adaptive functioning deficits and behaviour regulation impairments (e.g. impulsivity and repetitive behaviours). However, many of the findings in the literature are mixed and only explain a small proportion of the variance contributing to SIB. Limitations in the previous literature have centred on lack of availability of large and diverse samples, restricted age ranges and constraints of measurement. This study characterises a clinic-referred sample of children and adults currently presenting with and without SIB using a range of standardised and parent-report measures. The sample includes 144 individuals with ASD between the ages of 2.5 and 60.1 years. After adjusting for multiple tests, none of the variables maintained statistical significance between the group of individuals with and without SIB, but medium to large effect sizes were noted. These variables include parent-reported early motor and toileting delays and perinatal risk, and current cognitive and social impairment. The remaining variables, including current autism severity levels, early ASD symptomatology, impulsivity, executive functioning impairments, adaptive functioning, mood and anxiety, did not differ between those with and without current engagement in SIB. Utilising a diverse clinic-referred sample and standardised diagnostic tools, this study explored retrospective and current correlate risk markers of SIB in individuals with ASD. In addition to impairments in current functioning, specific early developmental delays and perinatal risk factors were preliminarily associated with the presence of SIB in individuals with ASD. Together these findings suggest that a set of specific characteristics may be related to both early risk and concurrent manifestation of SIB. Identifying this set of characteristics in early development may lead to faster identification and better intervention services, but future work utilising longitudinal design and multivariate analysis is warranted. © 2018 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  9. Life estimation and analysis of dielectric strength, hydrocarbon backbone and oxidation of high voltage multi stressed EPDM composites

    NASA Astrophysics Data System (ADS)

    Khattak, Abraiz; Amin, Muhammad; Iqbal, Muhammad; Abbas, Naveed

    2018-02-01

    Micro and nanocomposites of ethylene propylene diene monomer (EPDM) are recently studied for different characteristics. Study on life estimation and effects of multiple stresses on its dielectric strength and backbone scission and oxidation is also vital for endorsement of these composites for high voltage insulation and other outdoor applications. In order to achieve these goals, unfilled EPDM and its micro and nanocomposites are prepared at 23 phr micro silica and 6 phr nanosilica loadings respectively. Prepared samples are energized at 2.5 kV AC voltage and subjected for a long time to heat, ultraviolet radiation, acid rain, humidity and salt fog in accelerated manner in laboratory. Dielectric strength, leakage current and intensity of saturated backbone and carbonyl group are periodically measured. Loss in dielectric strength, increase in leakage current and backbone degradation and oxidation were observed in all samples. These effects were least in the case of EPDM nanocomposite. The nanocomposite sample also demonstrated longest shelf life.

  10. Magnetic order and magnetoelectric properties of R2CoMn O6 perovskites (R =Ho , Tm, Yb, and Lu)

    NASA Astrophysics Data System (ADS)

    Blasco, J.; García-Muñoz, J. L.; García, J.; Subías, G.; Stankiewicz, J.; Rodríguez-Velamazán, J. A.; Ritter, C.

    2017-07-01

    We present a detailed study on the magnetic structure and magnetoelectric properties of several double perovskites R2CoMn O6 (R =Ho , Tm, Yb, and Lu). All of these samples show an almost perfect (˜94 %) ordering of C o2 + and M n4 + cations in the unit cell. Our research reveals that the magnetic ground state strongly depends on the R size. For samples with larger R (Ho and Tm), the ground state is formed by a ferromagnetic order (F type) of C o2 + and M n4 + moments, while R either remains mainly disordered (Ho) or is coupled antiferromagnetically (Tm) to the Co/Mn sublattice. For samples with smaller R (Yb or Lu), competitive interactions lead to the formation of an E -type arrangement for the C o2 + and M n4 + moments with a large amount of extended defects such as stacking faults. The Y b3 + is partly ordered at very low temperature. The latter samples undergo a metamagnetic transition from the E into the F type, which is coupled to a negative magnetodielectric effect. Actually, the real part of dielectric permittivity shows an anomaly at the magnetic transition for the samples exhibiting an E -type order. This anomaly is absent in samples with F -type order, and, accordingly, it vanishes coupled to the metamagnetic transition for R =Yb or Lu samples. At room temperature, the huge values of the dielectric constant reveal the presence of Maxwell-Wagner depletion layers. Pyroelectric measurements reveal a high polarization at low temperature, but the onset of pyroelectric current is neither correlated to the kind of magnetic ordering nor to the magnetic transition. Our study identified the pyroelectric current as thermally stimulated depolarization current and electric-field polarization curves show a linear behavior at low temperature. Therefore, no clear ferroelectric transition occurs in these compounds.

  11. Plasma current collection of Z-93 thermal control paint as measured in the Lewis Research Center's plasma interaction facility

    NASA Technical Reports Server (NTRS)

    Hillard, G. Barry

    1993-01-01

    A sample of Z-93 thermal control paint was exposed to a simulated space environment in a plasma chamber. The sample was biased through a series of voltages ranging from -100 volts to +300 volts and electron and ion currents were measured. Currents were found to be in the micro-ampere range indicating that the material remains a reasonably good insulator under plasma conditions. As a second step, the sample was left in the chamber for six days and retested. Collected currents were reduced by from two to five times from the previous values indicating a substantial loss of conductivity. As a final test, the sample was removed, exposed to room conditions for two days, and returned to the chamber. Current measurements showed that the sample had partially recovered the lost conductivity. In addition to presenting these results, this report documents all of the experimental data as well as the statistical analyses performed.

  12. Validity of the Wechsler Test of Adult Reading (WTAR): effort considered in a clinical sample of U.S. military veterans.

    PubMed

    Whitney, Kriscinda A; Shepard, Polly H; Mariner, Jennifer; Mossbarger, Brad; Herman, Steven M

    2010-07-01

    The current study represents an examination of the construct validity of the Wechsler Test of Adult Reading (WTAR) among a sample of U.S. military veterans referred for outpatient neuropsychological evaluation that included a measure of negative response bias, namely, the Test of Memory Malingering (TOMM). This retrospective data analysis examined the relationship between the WTAR and measures of current verbal general intellectual function and current cognitive skills. Findings showed that, among patients passing the TOMM (N = 98), WTAR scores were most highly correlated with current verbal IQ but also showed significant correlations with verbal memory and lesser, but still significant, correlations with measures of visual-spatial memory. Discriminant validity for the WTAR was also shown among the group passing the TOMM in the sense that the WTAR, which is designed to measure verbal premorbid general intellectual skill, was not as highly correlated with measures of learning and memory as was a measure of current verbal general intellectual skill. Whereas scores on most study measures did significantly differ between the groups that passed versus failed the TOMM (N = 26), scores on the WTAR did not, suggesting that the WTAR may remain robust even in the face of suboptimal effort.

  13. Accounting for between-study variation in incremental net benefit in value of information methodology.

    PubMed

    Willan, Andrew R; Eckermann, Simon

    2012-10-01

    Previous applications of value of information methods for determining optimal sample size in randomized clinical trials have assumed no between-study variation in mean incremental net benefit. By adopting a hierarchical model, we provide a solution for determining optimal sample size with this assumption relaxed. The solution is illustrated with two examples from the literature. Expected net gain increases with increasing between-study variation, reflecting the increased uncertainty in incremental net benefit and reduced extent to which data are borrowed from previous evidence. Hence, a trial can become optimal where current evidence is sufficient assuming no between-study variation. However, despite the expected net gain increasing, the optimal sample size in the illustrated examples is relatively insensitive to the amount of between-study variation. Further percentage losses in expected net gain were small even when choosing sample sizes that reflected widely different between-study variation. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Beyond the "science of sophomores": does the rational choice explanation of crime generalize from university students to an actual offender sample?

    PubMed

    Bouffard, Jeff; Bry, Jeff; Smith, Shamayne; Bry, Rhonda

    2008-12-01

    Much of the criminological literature testing rational choice theory has utilized hypothetical scenarios presented to university students. Although this research generally supports rational choice theory, a common criticism is that conclusions from these studies may not generalize to samples of actual offenders. This study proceeds to examine this issue in two steps. First, a traditional sample of university students is examined to determine how various costs and benefits relate to their hypothetical likelihood of offending. Then the same data collection procedures are employed with a somewhat different sample of younger, adjudicated, and institutionalized offenders to determine whether the conclusions drawn from the student sample generalize to this offender sample. Results generally suggest that the content and process of hypothetical criminal decision making differ in the sample of known offenders relative to the university students. Limitations of the current study, as well as suggestions for future research, are discussed.

  15. Scalable multi-sample single-cell data analysis by Partition-Assisted Clustering and Multiple Alignments of Networks

    PubMed Central

    Samusik, Nikolay; Wang, Xiaowei; Guan, Leying; Nolan, Garry P.

    2017-01-01

    Mass cytometry (CyTOF) has greatly expanded the capability of cytometry. It is now easy to generate multiple CyTOF samples in a single study, with each sample containing single-cell measurement on 50 markers for more than hundreds of thousands of cells. Current methods do not adequately address the issues concerning combining multiple samples for subpopulation discovery, and these issues can be quickly and dramatically amplified with increasing number of samples. To overcome this limitation, we developed Partition-Assisted Clustering and Multiple Alignments of Networks (PAC-MAN) for the fast automatic identification of cell populations in CyTOF data closely matching that of expert manual-discovery, and for alignments between subpopulations across samples to define dataset-level cellular states. PAC-MAN is computationally efficient, allowing the management of very large CyTOF datasets, which are increasingly common in clinical studies and cancer studies that monitor various tissue samples for each subject. PMID:29281633

  16. Digital ac monitor

    DOEpatents

    Hart, George W.; Kern, Jr., Edward C.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  17. Digital ac monitor

    DOEpatents

    Hart, G.W.; Kern, E.C. Jr.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

  18. Molecular ecology studies of species radiations: current research gaps, opportunities and challenges.

    PubMed

    de la Harpe, Marylaure; Paris, Margot; Karger, Dirk N; Rolland, Jonathan; Kessler, Michael; Salamin, Nicolas; Lexer, Christian

    2017-05-01

    Understanding the drivers and limits of species radiations is a crucial goal of evolutionary genetics and molecular ecology, yet research on this topic has been hampered by the notorious difficulty of connecting micro- and macroevolutionary approaches to studying the drivers of diversification. To chart the current research gaps, opportunities and challenges of molecular ecology approaches to studying radiations, we examine the literature in the journal Molecular Ecology and revisit recent high-profile examples of evolutionary genomic research on radiations. We find that available studies of radiations are highly unevenly distributed among taxa, with many ecologically important and species-rich organismal groups remaining severely understudied, including arthropods, plants and fungi. Most studies employed molecular methods suitable over either short or long evolutionary time scales, such as microsatellites or restriction site-associated DNA sequencing (RAD-seq) in the former case and conventional amplicon sequencing of organellar DNA in the latter. The potential of molecular ecology studies to address and resolve patterns and processes around the species level in radiating groups of taxa is currently limited primarily by sample size and a dearth of information on radiating nuclear genomes as opposed to organellar ones. Based on our literature survey and personal experience, we suggest possible ways forward in the coming years. We touch on the potential and current limitations of whole-genome sequencing (WGS) in studies of radiations. We suggest that WGS and targeted ('capture') resequencing emerge as the methods of choice for scaling up the sampling of populations, species and genomes, including currently understudied organismal groups and the genes or regulatory elements expected to matter most to species radiations. © 2017 John Wiley & Sons Ltd.

  19. The functional spectrum of low-frequency coding variation.

    PubMed

    Marth, Gabor T; Yu, Fuli; Indap, Amit R; Garimella, Kiran; Gravel, Simon; Leong, Wen Fung; Tyler-Smith, Chris; Bainbridge, Matthew; Blackwell, Tom; Zheng-Bradley, Xiangqun; Chen, Yuan; Challis, Danny; Clarke, Laura; Ball, Edward V; Cibulskis, Kristian; Cooper, David N; Fulton, Bob; Hartl, Chris; Koboldt, Dan; Muzny, Donna; Smith, Richard; Sougnez, Carrie; Stewart, Chip; Ward, Alistair; Yu, Jin; Xue, Yali; Altshuler, David; Bustamante, Carlos D; Clark, Andrew G; Daly, Mark; DePristo, Mark; Flicek, Paul; Gabriel, Stacey; Mardis, Elaine; Palotie, Aarno; Gibbs, Richard

    2011-09-14

    Rare coding variants constitute an important class of human genetic variation, but are underrepresented in current databases that are based on small population samples. Recent studies show that variants altering amino acid sequence and protein function are enriched at low variant allele frequency, 2 to 5%, but because of insufficient sample size it is not clear if the same trend holds for rare variants below 1% allele frequency. The 1000 Genomes Exon Pilot Project has collected deep-coverage exon-capture data in roughly 1,000 human genes, for nearly 700 samples. Although medical whole-exome projects are currently afoot, this is still the deepest reported sampling of a large number of human genes with next-generation technologies. According to the goals of the 1000 Genomes Project, we created effective informatics pipelines to process and analyze the data, and discovered 12,758 exonic SNPs, 70% of them novel, and 74% below 1% allele frequency in the seven population samples we examined. Our analysis confirms that coding variants below 1% allele frequency show increased population-specificity and are enriched for functional variants. This study represents a large step toward detecting and interpreting low frequency coding variation, clearly lays out technical steps for effective analysis of DNA capture data, and articulates functional and population properties of this important class of genetic variation.

  20. Rorschach Comprehensive System data for a sample of 141 adult nonpatients from Denmark.

    PubMed

    Ivanouw, Jan

    2007-01-01

    A sample (n = 141) of Danish nonpatients 25-50 years of age, never hospitalized with a psychiatric diagnosis and currently employed, was demographically representative of two geographical areas of Copenhagen with different social strain. The sample, as well as 45 persons not currently employed, was tested with the Rorschach (Exner, 1995), MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989), Word Association Test (Ivanouw, 1999b), WAIS Comprehension subtest (Hess, 1974), and SCL-90-R (Olsen, Mortenson, & Bech, 2006). Half of the persons contacted volunteered for the study. There was no difference in rate of volunteering between a standard no-feedback condition and a feedback condition; the latter, however, tended to attract more psychologically resourceful persons. The employed persons tended to appear healthier than the not employed. Response style of the subjects, quality of the Rorschach protocols, reliability of scoring, and the effect of the data being grouped on geographical area and examiner were examined. Form level, color, texture, cooperative movement, and EA were lower than in the Comprehensive System (CS; n = 450) sample, but higher than in nine international nonpatient Rorschach studies. Unique for the Danish sample was a low number of animal movement answers. The Rorschach data showed women to be healthier than men. Differences in Rorschach variables based on educational level were small.

  1. Influence of the magnetic field profile on ITER conductor testing

    NASA Astrophysics Data System (ADS)

    Nijhuis, A.; Ilyin, Y.; ten Kate, H. H. J.

    2006-08-01

    We performed simulations with the numerical CUDI-CICC code on a typical short ITER (International Thermonuclear Experimental Reactor) conductor test sample of dual leg configuration, as usually tested in the SULTAN test facility, and made a comparison with the new EFDA-Dipole test facility offering a larger applied DC field region. The new EFDA-Dipole test facility, designed for short sample testing of conductors for ITER, has a homogeneous high field region of 1.2 m, while in the SULTAN facility this region is three times shorter. The inevitable non-uniformity of the current distribution in the cable, introduced by the joints at both ends, has a degrading effect on voltage-current (VI) and voltage-temperature (VT) characteristics, particularly for these short samples. This can easily result in an underestimation or overestimation of the actual conductor performance. A longer applied DC high field region along a conductor suppresses the current non-uniformity by increasing the overall longitudinal cable electric field when reaching the current sharing mode. The numerical interpretation study presented here gives a quantitative analysis for a relevant practical case of a test of a short sample poloidal field coil insert (PFCI) conductor in SULTAN. The simulation includes the results of current distribution analysis from self-field measurements with Hall sensor arrays, current sharing measurements and inter-petal resistance measurements. The outcome of the simulations confirms that the current uniformity improves with a longer high field region but the 'measured' VI transition is barely affected, though the local peak voltages become somewhat suppressed. It appears that the location of the high field region and voltage taps has practically no influence on the VI curve as long as the transverse voltage components are adequately cancelled. In particular, for a thin conduit wall, the voltage taps should be connected to the conduit in the form of an (open) azimuthally soldered wire, averaging the transverse conduit surface potentials initiated in the joints.

  2. Occurrence and distribution of microplastics at selected coastal sites along the southeastern United States.

    PubMed

    Yu, Xubiao; Ladewig, Samantha; Bao, Shaowu; Toline, Catherine A; Whitmire, Stefanie; Chow, Alex T

    2018-02-01

    To investigate the occurrence and distribution of microplastics in the southeastern coastal region of the United States, we quantified the amount of microplastics in sand samples from multiple coastal sites and developed a predictive model to understand the drift of plastics via ocean currents. Sand samples from eighteen National Park Service (NPS) beaches in the Southeastern Region were collected and microplastics were isolated from each sample. Microplastic counts were compared among sites and local geography was used to make inferences about sources and modes of distribution. Samples were analyzed to identify the composition of particles using Fourier transform infrared spectroscopy (FTIR). To predict the spatiotemporal distribution and movements of particles via coastal currents, a Regional Ocean Modeling System (ROMS) was applied. Microplastics were detected in each of the sampled sites although abundance among sites was highly variable. Approximately half of the samples were dominated by thread-like and fibrous materials as opposed to beads and particles. Results of FTIR suggested that 24% consisted of polyethylene terephthalate (PET), while about 68% of the fibers tested were composed of man-made cellulosic materials such as rayon. Based on published studies examining sources of microplastics, the shape of the particles found here (mostly fibers) and the presence of PET, we infer the source of microplastics in coastal areas is mainly from urban areas, such as wastewater discharge, rather than breakdown of larger marine debris drifting in the ocean. Local geographic features, e.g., the nearness of sites to large rivers and urbanized areas, explain variance in amount of microplastics among sites. Additionally, the distribution of simulated particles is explained by ocean current patterns; computer simulations were correlated with field observations, reinforcing the idea that ocean currents can be a good predictor of the fate and distribution of microplastics at the sites sampled here. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Performance Evaluation of the Operational Air Quality Monitor for Water Testing Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2014-01-01

    In the history of manned spaceflight, environmental monitoring has relied heavily on archival sampling. For short missions, this type of sample collection was sufficient; returned samples provided a snapshot of the presence of chemical and biological contaminants in the spacecraft air and water. However, with the construction of the International Space Station (ISS) and the subsequent extension of mission durations, soon to be up to one year, the need for enhanced, real-time environmental monitoring became more pressing. The past several years have seen the implementation of several real-time monitors aboard the ISS, complemented with reduced archival sampling. The station air is currently monitored for volatile organic compounds (VOCs) using gas chromatography-differential mobility spectrometry (Air Quality Monitor [AQM]). The water on ISS is analyzed to measure total organic carbon and biocide concentrations using the Total Organic Carbon Analyzer (TOCA) and the Colorimetric Water Quality Monitoring Kit (CWQMK), respectively. The current air and water monitors provide important data, but the number and size of the different instruments makes them impractical for future exploration missions. It is apparent that there is still a need for improvements in environmental monitoring capabilities. One such improvement could be realized by modifying a single instrument to analyze both air and water. As the AQM currently provides quantitative, compound-specific information for target compounds present in air samples, and many of the compounds are also targets for water quality monitoring, this instrument provides a logical starting point to evaluate the feasibility of this approach. In this presentation, we will discuss our recent studies aimed at determining an appropriate method for introducing VOCs from water samples into the gas phase and our current work, in which an electro-thermal vaporization unit has been interfaced with the AQM to analyze target analytes at the relevant concentrations at which they are routinely detected in archival water samples from the ISS.

  4. Dose–response associations between cycling activity and risk of hypertension in regular cyclists: The UK Cycling for Health Study

    PubMed Central

    Hollingworth, M; Harper, A; Hamer, M

    2015-01-01

    Most population studies on physical activity and health have involved largely inactive men and women, thus making it difficult to infer if health benefits occur at exercise levels above the current minimum guidelines. The aim was to examine associations between cycling volume and classical cardiovascular risk markers, including hypertension and hypercholesterolemia, in a population sample of habitual cyclists. A nationwide sample comprising 6949 men and women (aged 47.6 years on average) completed questions about their cycling levels, demographics and health. Nearly the entire sample (96.3%) achieved the current minimum physical activity recommendation through cycling alone. There was a dose–response association between cycling volume and risk of diagnosed hypertension (P-trend =0.001), with odds ratios of 0.98 (95% confidence interval (CI), 0.80–1.21), 0.86 (0.70, 1.06), 0.67 (95% CI, 0.53–0.83) across categories of 23–40, 40–61 and >61 metabolic equivalent hours/week (MET-h/week) compared with <23 MET-h/week. These associations persisted in models adjusted for age, sex, smoking, alcohol, body mass index (BMI) and other moderatevigorous physical activities. We also observed inverse associations between cycling volume and other risk factors including BMI and hypercholesterolemia. In summary, results from a population sample of cyclists suggest that additional cardiovascular health benefits can be achieved beyond the current minimum physical activity recommendation. PMID:25273856

  5. Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization.

    PubMed

    Woodall, Christopher W; Rondeux, Jacques; Verkerk, Pieter J; Ståhl, Göran

    2009-10-01

    Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world's forested landscapes is scattered. The goal of this study is to describe the status, DW components measured, sample methods employed, and DW component thresholds used by national forest inventories that currently inventory DW around the world. Study results indicate that most countries do not inventory forest DW. Globally, we estimate that about 13% of countries inventory DW using a diversity of sample methods and DW component definitions. A common feature among DW inventories was that most countries had only just begun DW inventories and employ very low sample intensities. There are major hurdles to harmonizing national forest inventories of DW: differences in population definitions, lack of clarity on sample protocols/estimation procedures, and sparse availability of inventory data/reports. Increasing database/estimation flexibility, developing common dimensional thresholds of DW components, publishing inventory procedures/protocols, releasing inventory data/reports to international peer review, and increasing communication (e.g., workshops) among countries inventorying DW are suggestions forwarded by this study to increase DW inventory harmonization.

  6. Preparation and Thermal Characterization of Annealed Gold Coated Porous Silicon

    PubMed Central

    Behzad, Kasra; Mat Yunus, Wan Mahmood; Talib, Zainal Abidin; Zakaria, Azmi; Bahrami, Afarin

    2012-01-01

    Porous silicon (PSi) layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm2 fixed current density for different etching times. The samples were coated with a 50–60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron microscopy (SEM). Photoacoustic spectroscopy (PAS) measurements were carried out to measure the thermal diffusivity (TD) of the PSi and Au/PSi samples. For the Au/PSi samples, the thermal diffusivity was measured before and after annealing to study the effect of annealing. Also to study the aging effect, a comparison was made between freshly annealed samples and samples 30 days after annealing. PMID:28817037

  7. Analysis Model and Numerical Simulation of Thermoelectric Response of CFRP Composites

    NASA Astrophysics Data System (ADS)

    Lin, Yueguo

    2018-05-01

    An electric current generates Joule heating, and under steady state conditions, a sample exhibits a balance between the strength dissipated by the Joule effect and the heat exchange with the environment by radiation and convection. In the present paper, theoretical model, numerical FEM and experimental methods have been used to analyze the radiation and free convection properties in CFRP composite samples heated by an electric current. The materials employed in these samples have applications in many aeronautic devices. This study addresses two types of composite materials, UD [0]8 and QI [45/90/-45/0]S, which were prepared for thermoelectric experiments. A DC electric current (ranging from 1A to 8A) was injected through the specimen ends to find the coupling effect between the electric current and temperature. An FE model and simplified thermoelectric analysis model are presented in detail to represent the thermoelectric data. These are compared with the experimental results. All of the test equipments used to obtain the experimental data and the numerical simulations are characterized, and we find that the numerical simulations correspond well with the experiments. The temperature of the surface of the specimen is almost proportional to the electric current. The simplified analysis model was used to calculate the balance time of the temperature, which is consistent throughout all of the experimental investigations.

  8. Five-year trends in patterns of drug use among people who use stimulants in dance contexts in the United Kingdom.

    PubMed

    McCambridge, Jim; Mitcheson, Luke; Winstock, Adam; Hunt, Neil

    2005-08-01

    To describe and evaluate trends in the use of stimulant drugs over a 5-year period using an under-studied data collection method. Repeated-measures cross-sectional survey. Annual magazine-based survey targeting people who use stimulant drugs in dance contexts. Life-time use prevalence (ever used), age of first use, current use prevalence (any use within the last month) and extent of use within the last month (number of days used) for a range of stimulant drugs. Additional measures of quantity of ecstasy used were also collected. Trends in life-time and current prevalence over time have been detected and comparisons made between different stimulant drugs. Evidence is obtained of broad stability in patterns of stimulant use in respect of age of first use and frequency of use among ongoing users. Despite an apparent reduction in the current prevalence of ecstasy use, the proportion of heavy users (usually >4 pills per session) has more than doubled between 1999 and 2003. This purposively sampled population study has yielded time trend data broadly consistent with other indicators, where they exist, and also has demonstrable potential to identify new drug trends. Further comparisons of purposive samples and randomly formed samples are needed.

  9. Inattentiveness, parental smoking and adolescent smoking initiation.

    PubMed

    Barman, Satu K; Pulkkinen, Lea; Kaprio, Jaakko; Rose, Richard J

    2004-08-01

    To examine how adolescents' inattentive behaviour, together with parental smoking patterns, predicts smoking initiation by age 14. DESIGN, SETTINGS: A prospective, longitudinal study: baseline at ages 11-12, follow-up at age 14. A population-based sample of Finnish twins, born 1983-1987, with parents and classroom teachers as additional informants. Two groups were formed, allocating the co-twins of each family into separate groups: the study sample and a replication sample. Twin individuals (n = 4552), aged 11-12 at baseline and 14 (average 14.04 years) at follow-up. At baseline, inattentiveness was assessed with the Multidimensional Peer Nomination Inventory (MPNI, Teacher Form) and parental smoking with individual questionnaires completed by each twins' parents; at the age 14 follow-up, adolescent smoking was assessed with a self-report questionnaire. At age 14, 57% reported never having smoked, 34% had experimented with cigarettes and 9% were current smokers. Inattentiveness and parental smoking additively predicted both experimental and current smoking in adolescence. The effects were independent of each other. The risk related to inattentiveness itself is high, but in combination with the effects of parental smoking, the probability of current smoking can rise as high as 38%, compared with 5% without these two risk factors. For prevention purposes, parental commitment to non-smoking should be emphasized.

  10. Visual Word Recognition Across the Adult Lifespan

    PubMed Central

    Cohen-Shikora, Emily R.; Balota, David A.

    2016-01-01

    The current study examines visual word recognition in a large sample (N = 148) across the adult lifespan and across a large set of stimuli (N = 1187) in three different lexical processing tasks (pronunciation, lexical decision, and animacy judgments). Although the focus of the present study is on the influence of word frequency, a diverse set of other variables are examined as the system ages and acquires more experience with language. Computational models and conceptual theories of visual word recognition and aging make differing predictions for age-related changes in the system. However, these have been difficult to assess because prior studies have produced inconsistent results, possibly due to sample differences, analytic procedures, and/or task-specific processes. The current study confronts these potential differences by using three different tasks, treating age and word variables as continuous, and exploring the influence of individual differences such as vocabulary, vision, and working memory. The primary finding is remarkable stability in the influence of a diverse set of variables on visual word recognition across the adult age spectrum. This pattern is discussed in reference to previous inconsistent findings in the literature and implications for current models of visual word recognition. PMID:27336629

  11. Increased prevalence of vegetarianism among women with eating pathology.

    PubMed

    Zuromski, Kelly L; Witte, Tracy K; Smith, April R; Goodwin, Natalie; Bodell, Lindsay P; Bartlett, Mary; Siegfried, Nicole

    2015-12-01

    Prior research has established a link between vegetarianism and disordered eating but has typically sampled vegetarians. This study examined prevalence of and variables related to vegetarianism in three samples with varying severity of eating pathology. Sample 1 consisted of female undergraduates who denied history of or current disordered eating (i.e., nonclinical; n=73), or engaged in disordered eating over past month (i.e., subclinical; n=136). Sample 2 included 69 female patients receiving residential treatment at an eating disorder center (i.e., clinical sample). Differences between groups were analyzed using Fisher's exact test. The prevalence of lifetime vegetarianism was lowest in the nonclinical group (6.80%) and highest in the clinical group (34.80%), with the subclinical group falling in between (17.60%). According to Fisher's exact test, all pairwise comparisons between groups were statistically significant (p's<.05). Regarding current vegetarian status, the clinical group was more likely (11.10%) than both other groups to self-identify as current vegetarians. Endorsement of vegetarianism was highest among females with severe eating pathology. Future research should use longitudinal data to examine the temporal relationship between these variables, or other underlying factors that may contribute to the co-occurrence of eating pathology and vegetarianism. Clinically, endorsement of vegetarianism may also be an important variable to consider in treatment disordered eating. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Mechanical properties and eddy current testing of thermally aged Z3CN20.09M cast duplex stainless steel

    NASA Astrophysics Data System (ADS)

    Liu, Tonghua; Wang, Wei; Qiang, Wenjiang; Shu, Guogang

    2018-04-01

    To study the thermal aging embrittlement of Z3CN20.09M duplex stainless steel produced in China, accelerated thermal aging experiments were carried out at 380 °C up to 9000 h. Microhardness measurements, Charpy impact and eddy current tests were performed on aged samples to characterize their thermal aging embrittlement. The results showed that the signal amplitude of eddy current decreased with the increase in aging time. Two quantitative correlations of the eddy current signal amplitude with both the Charpy impact energy, and the Vickers microhardness of the ferrite phase are obtained. The study showed that eddy current testing could be used to non-destructively evaluate the thermal aging embrittlement of cast duplex stainless steels.

  13. Teachers' Perceptions on Current Piano Use in the Elementary General Music Classroom

    ERIC Educational Resources Information Center

    Baker, Valerie A.

    2017-01-01

    The purpose of this study was to identify teacher opinion of piano use, the amount of piano use, and current purposes for pianos in elementary general music classrooms. A geographically diverse sample of general music teachers (N = 189) completed a piano use survey. The data indicated that teachers felt piano was an important part of elementary…

  14. Stress and Traumatic Stress: How Do Past Events Influence Current Traumatic Stress among Mothers Experiencing Homelessness?

    ERIC Educational Resources Information Center

    Williams, Julie K.; Hall, James A.

    2009-01-01

    The purpose of this research was to evaluate the relationship between past traumatic events and the level of current traumatic stress among mothers experiencing homelessness. The data for this study were gathered from 75 homeless mothers between May 2006 and October 2006 using a cross-sectional survey design with purposive sampling. All mothers…

  15. Determinants of Young Australians' Environmental Actions: The Role of Responsibility Attributions, Locus of Control, Knowledge and Attitudes

    ERIC Educational Resources Information Center

    Fielding, Kelly S.; Head, Brian W.

    2012-01-01

    The current study investigates determinants of young Australians' pro-environmental intentions and actions. Two samples of young people took part in the research: 12-17-year-olds (N = 1529) currently in secondary schooling and 18-24-year-olds (N = 2192) in post-secondary schooling or workforce. All participants completed an online "Youth and…

  16. The Relation of Childhood Abuse and Early Parenting Experiences to Current Marital Quality in a Nonclinical Sample.

    ERIC Educational Resources Information Center

    Belt, William; Abidin, Richard R.

    1996-01-01

    This study of 159 nonclinical married adults found that, for women, verbal abuse in childhood was predictive of marital conflict, and the caring parenting they experienced predicted the depth of the marital relationship. For men, the abuse variables did not predict any dimension of their current marital relationship. Among parenting variables,…

  17. Effects of Age of English Exposure, Current Input/Output, and Grade on Bilingual Language Performance

    ERIC Educational Resources Information Center

    Bedore, Lisa M.; Pena, Elizabeth D.; Griffin, Zenzi M.; Hixon, J. Gregory

    2016-01-01

    This study evaluates the effects of Age of Exposure to English (AoEE) and Current Input/Output on language performance in a cross-sectional sample of Spanish-English bilingual children. First- (N = 586) and third-graders (N = 298) who spanned a wide range of bilingual language experience participated. Parents and teachers provided information…

  18. Landauer-Büttiker and Thouless Conductance

    NASA Astrophysics Data System (ADS)

    Bruneau, L.; Jakšić, V.; Last, Y.; Pillet, C.-A.

    2015-08-01

    In the independent electron approximation, the average (energy/charge/entropy) current flowing through a finite sample connected to two electronic reservoirs can be computed by scattering theoretic arguments which lead to the famous Landauer-Büttiker formula. Another well known formula has been proposed by Thouless on the basis of a scaling argument. The Thouless formula relates the conductance of the sample to the width of the spectral bands of the infinite crystal obtained by periodic juxtaposition of . In this spirit, we define Landauer-Büttiker crystalline currents by extending the Landauer-Büttiker formula to a setup where the sample is replaced by a periodic structure whose unit cell is . We argue that these crystalline currents are closely related to the Thouless currents. For example, the crystalline heat current is bounded above by the Thouless heat current, and this bound saturates iff the coupling between the reservoirs and the sample is reflectionless. Our analysis leads to a rigorous derivation of the Thouless formula from the first principles of quantum statistical mechanics.

  19. Understanding resilience in same-sex parented families: the work, love, play study

    PubMed Central

    2010-01-01

    Background While families headed by same-sex couples have achieved greater public visibility in recent years, there are still many challenges for these families in dealing with legal and community contexts that are not supportive of same-sex relationships. The Work, Love, Play study is a large longitudinal study of same-sex parents. It aims to investigate many facets of family life among this sample and examine how they change over time. The study focuses specifically on two key areas missing from the current literature: factors supporting resilience in same-sex parented families; and health and wellbeing outcomes for same-sex couples who undergo separation, including the negotiation of shared parenting arrangements post-separation. The current paper aims to provide a comprehensive overview of the design and methods of this longitudinal study and discuss its significance. Methods/Design The Work, Love, Play study is a mixed design, three wave, longitudinal cohort study of same-sex attracted parents. The sample includes lesbian, gay, bisexual and transgender parents in Australia and New Zealand (including single parents within these categories) caring for any children under the age of 18 years. The study will be conducted over six years from 2008 to 2014. Quantitative data are to be collected via three on-line surveys in 2008, 2010 and 2012 from the cohort of parents recruited in Wave1. Qualitative data will be collected via interviews with purposively selected subsamples in 2012 and 2013. Data collection began in 2008 and 355 respondents to Wave One of the study have agreed to participate in future surveys. Work is currently underway to increase this sample size. The methods and survey instruments are described. Discussion This study will make an important contribution to the existing research on same-sex parented families. Strengths of the study design include the longitudinal method, which will allow understanding of changes over time within internal family relationships and social supports. Further, the mixed method design enables triangulation of qualitative and quantitative data. A broad recruitment strategy has already enabled a large sample size with the inclusion of both gay men and lesbians. PMID:20211027

  20. Understanding resilience in same-sex parented families: the work, love, play study.

    PubMed

    Power, Jennifer J; Perlesz, Amaryll; Schofield, Margot J; Pitts, Marian K; Brown, Rhonda; McNair, Ruth; Barrett, Anna; Bickerdike, Andrew

    2010-03-09

    While families headed by same-sex couples have achieved greater public visibility in recent years, there are still many challenges for these families in dealing with legal and community contexts that are not supportive of same-sex relationships. The Work, Love, Play study is a large longitudinal study of same-sex parents. It aims to investigate many facets of family life among this sample and examine how they change over time. The study focuses specifically on two key areas missing from the current literature: factors supporting resilience in same-sex parented families; and health and wellbeing outcomes for same-sex couples who undergo separation, including the negotiation of shared parenting arrangements post-separation. The current paper aims to provide a comprehensive overview of the design and methods of this longitudinal study and discuss its significance. The Work, Love, Play study is a mixed design, three wave, longitudinal cohort study of same-sex attracted parents. The sample includes lesbian, gay, bisexual and transgender parents in Australia and New Zealand (including single parents within these categories) caring for any children under the age of 18 years. The study will be conducted over six years from 2008 to 2014. Quantitative data are to be collected via three on-line surveys in 2008, 2010 and 2012 from the cohort of parents recruited in Wave1. Qualitative data will be collected via interviews with purposively selected subsamples in 2012 and 2013. Data collection began in 2008 and 355 respondents to Wave One of the study have agreed to participate in future surveys. Work is currently underway to increase this sample size. The methods and survey instruments are described. This study will make an important contribution to the existing research on same-sex parented families. Strengths of the study design include the longitudinal method, which will allow understanding of changes over time within internal family relationships and social supports. Further, the mixed method design enables triangulation of qualitative and quantitative data. A broad recruitment strategy has already enabled a large sample size with the inclusion of both gay men and lesbians.

  1. Unpacking Sleep and Suicide in Older Adults in a Combined Online Sample.

    PubMed

    Golding, Shea; Nadorff, Michael R; Winer, E Samuel; Ward, Kathryn Claire

    2015-12-15

    Duration of insomnia symptoms and nightmares are related to suicidal risk in young adults independent of current symptoms of insomnia, nightmares, anxiety, depression, and PTSD. However, this relation has yet to be examined among older adults, despite older adults being at higher risk of suicidal behavior. Further, the current study aims to replicate previous research among younger adults showing that insomnia symptoms and nightmares are associated with suicide risk independent of the interpersonal psychological theory of suicide (IPTS). The present study utilized 167 participants age 55 and older obtained by combining two independent mTurk data collections of adults in the United States. In the current sample, duration of nightmares was associated with suicide risk in older adults independent of symptoms of current insomnia and nightmares, duration of insomnia, and symptoms of PTSD, anhedonia, and the IPTS. Our findings suggest that the duration of nightmares (i.e., how long someone has been experiencing nightmares) predict substantial variance in suicide risk among older adults in addition to the risk factors typically examined. Thus, assessment of sleep dysfunction is important when assessing suicide risk among older adults. © 2015 American Academy of Sleep Medicine.

  2. Coaxial test fixture

    DOEpatents

    Praeg, W.F.

    1984-03-30

    This invention pertains to arrangements for performing electrical tests on contact material samples, and in particular for testing contact material test samples in an evacuated environment under high current loads. Frequently, it is desirable in developing high-current separable contact material, to have at least a preliminary analysis of selected candidate conductor materials. Testing of material samples will hopefully identify materials unsuitable for high current electrical contact without requiring incorporation of the materials into a completed and oftentimes complex structure.

  3. Health risk assessment of drinking arsenic-containing groundwater in Hasilpur, Pakistan: effect of sampling area, depth, and source.

    PubMed

    Tabassum, Riaz Ahmad; Shahid, Muhammad; Dumat, Camille; Niazi, Nabeel Khan; Khalid, Sana; Shah, Noor Samad; Imran, Muhammad; Khalid, Samina

    2018-02-10

    Currently, several news channels and research publications have highlighted the dilemma of arsenic (As)-contaminated groundwater in Pakistan. However, there is lack of data regarding groundwater As content of various areas in Pakistan. The present study evaluated As contamination and associated health risks in previously unexplored groundwater of Hasilpur-Pakistan. Total of 61 groundwater samples were collected from different areas (rural and urban), sources (electric pump, hand pump, and tubewell) and depths (35-430 ft or 11-131 m). The water samples were analyzed for As level and other parameters such as pH, electrical conductivity, total dissolved solids, cations, and anions. It was found that 41% (25 out of 61) water samples contained As (≥ 5 μg/L). Out of 25 As-contaminated water samples, 13 water samples exceeded the permissible level of WHO (10 μg/L). High As contents have been found in tubewell samples and at high sampling depths (> 300 ft). The major As-contaminated groundwater in Hasilpur is found in urban areas. Furthermore, health risk and cancer risk due to As contamination were also assessed with respect to average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk (CR). The values of HQ and CR of As in Hasilpur were up to 58 and 0.00231, respectively. Multivariate analysis revealed a positive correlation between groundwater As contents, pH, and depth in Hasilpur. The current study proposed the proper monitoring and management of well water in Hasilpur to minimize the As-associated health hazards.

  4. Method and apparatus for generating motor current spectra to enhance motor system fault detection

    DOEpatents

    Linehan, D.J.; Bunch, S.L.; Lyster, C.T.

    1995-10-24

    A method and circuitry are disclosed for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed. 29 figs.

  5. How (and How Much) Do Schools Matter? Variation in K-8th Grade Achievement Trajectories in a National Sample

    ERIC Educational Resources Information Center

    Schwartz, Kate; Cappella, Elise; Scott, Marc; Seidman, Edward; Kim, Ha Yeon

    2015-01-01

    The current study extends research on the transition to early adolescence and middle grade schools by examining students' achievement trajectories from school entry through 8th grade in a national sample, and beginning to disassociate the role of school context and school grade configuration in achievement trajectories. Data were drawn from the…

  6. Assessing the Impact of Harassment by Peers: Incident Characteristics and Outcomes in a National Sample of Youth

    ERIC Educational Resources Information Center

    Turner, Heather A.; Mitchell, Kimberly J.; Jones, Lisa; Shattuck, Anne

    2017-01-01

    Although there are widely held assumptions about the characteristics of peer bullying that are of greatest concern, very few studies have empirically assessed which characteristics most affect its impact. The current research addresses this gap by using a nationally representative U.S. sample of youth ages 10-20 to examine the relative effects of…

  7. A Cross-National Validation of the Academic Expectations Stress Inventory with Chinese and Korean High School Students

    ERIC Educational Resources Information Center

    Zhang, Xiaozhou; Tze, Virginia M. C.; Buhr, Erin; Klassen, Robert M.; Daniels, Lia M.

    2016-01-01

    The current study provided evidence for the factor structure of the Academic Expectation Stress Inventory (AESI) in a sample of 213 Mainland Chinese and 184 South Korean high school students. We examined cross-national invariance of the AESI using multiple-group confirmatory factor analysis across two Asian cultural samples. Results suggested a…

  8. Early Adolescent Depressive Mood: Direct and Indirect Effects of Attributional Styles and Coping

    ERIC Educational Resources Information Center

    Chan, Siu Mui

    2012-01-01

    The present study used a cross-sectional survey design to examine how adolescent depressive mood was related to attributional styles and coping strategies with a sample of 326 youths (aged 8-14 years). With the cutting point adopted in the West, 20.9% of the current sample reported depressive symptoms. Regression analysis results show that, with…

  9. The Mediational Role of Posttraumatic Stress in the Relationship between Domestic Violence Exposure and Peer Victimisation: A Cambodian Sample

    ERIC Educational Resources Information Center

    Williamson, Rachel E.; Reed, David E., II.; Wickham, Robert E.; Field, Nigel P.

    2018-01-01

    Research demonstrates that children exposed to domestic violence experience a myriad of internalising and externalising symptoms. The current study examines this pathway within a Cambodian sample, specifically determining if the effect of witnessing domestic violence on the child's tendency to bully or to be bullied is mediated by symptoms of…

  10. Small-Sample DIF Estimation Using Log-Linear Smoothing: A SIBTEST Application. Research Report. ETS RR-07-10

    ERIC Educational Resources Information Center

    Puhan, Gautam; Moses, Tim P.; Yu, Lei; Dorans, Neil J.

    2007-01-01

    The purpose of the current study was to examine whether log-linear smoothing of observed score distributions in small samples results in more accurate differential item functioning (DIF) estimates under the simultaneous item bias test (SIBTEST) framework. Data from a teacher certification test were analyzed using White candidates in the reference…

  11. Is Longing Only for Germans? A Cross-Cultural Comparison of Sehnsucht in Germany and the United States

    ERIC Educational Resources Information Center

    Scheibe, Susanne; Blanchard-Fields, Fredda; Wiest, Maja; Freund, Alexandra M.

    2011-01-01

    "Sehnsucht", the longing or yearning for ideal yet seemingly unreachable states of life, is a salient topic in German culture and has proven useful for understanding self-regulation across adulthood in a German sample (e.g., Scheibe, Freund, & Baltes, 2007). The current study tested whether findings for German samples could be…

  12. Is Accuracy of Weight Perception Associated with Health Risk Behaviors in a Diverse Sample of Obese Adolescents?

    ERIC Educational Resources Information Center

    Lenhart, Clare M.; Daly, Brian P.; Eichen, Dawn M.

    2011-01-01

    Current evidence is equivocal as to whether adolescent's perception of weight status is linked to both healthy and risky behaviors. This study examined the association between accurate and inaccurate perception of weight and self-reported health and risk behaviors among a diverse sample of obese, urban adolescents. Data were analyzed from 1,180…

  13. Theory of Mind Development in Chinese Children: A Meta-Analysis of False-Belief Understanding across Cultures and Languages

    ERIC Educational Resources Information Center

    Liu, David; Wellman, Henry M.; Tardif, Twila; Sabbagh, Mark A.

    2008-01-01

    Theory of mind is claimed to develop universally among humans across cultures with vastly different folk psychologies. However, in the attempt to test and confirm a claim of universality, individual studies have been limited by small sample sizes, sample specificities, and an overwhelming focus on Anglo-European children. The current meta-analysis…

  14. Summary of nutrient and biomass data from two aspen sites in western United States

    Treesearch

    Robert S. Johnston; Dale L. Bartos

    1977-01-01

    Summary tables are presented for aboveground biomass and nutrient concentrations for 20 aspen trees (Populus tremuloides Michx.) that were sampled at two study sites in Utah and Wyoming. Trees were divided into seven components - leaves, current twigs, old twigs, deadwood (branches), branches, bark, and bole wood. Samples from each component were analyzed for nitrogen...

  15. Inattention/Overactivity Following Early Severe Institutional Deprivation: Presentation and Associations in Early Adolescence

    ERIC Educational Resources Information Center

    Stevens, Suzanne E.; Sonuga-Barke, Edmund J. S.; Kreppner, Jana M.; Beckett, Celia; Castle, Jenny; Colvert, Emma; Groothues, Christine; Hawkins, Amanda; Rutter, Michael

    2008-01-01

    The current study examined the persistence and phenotypic presentation of inattention/overactivity (I/O) into early adolescence, in a sample of institution reared (IR) children adopted from Romania before the age of 43 months. Total sample comprised 144 IR and 21 non-IR Romanian adoptees, and a comparison group of 52 within-UK adoptees, assessed…

  16. Co-Occurrence of Conduct Disorder and Depression in a Clinic-Based Sample of Boys with ADHD

    ERIC Educational Resources Information Center

    Drabick, Deborah A. G.; Gadow, Kenneth D.; Sprafkin, Joyce

    2006-01-01

    Background: Children with attention-deficit/hyperactivity disorder (ADHD) are at risk for the development of comorbid conduct disorder (CD) and depression. The current study examined potential psychosocial risk factors for CD and depression in a clinic-based sample of 203 boys (aged 6-10 years) with ADHD. Methods: The boys and their mothers…

  17. Population-based prevalence of smoking in psychiatric inpatients: a focus on acute suicide risk and major diagnostic groups.

    PubMed

    Lineberry, Timothy W; Allen, Josiah D; Nash, Jessica; Galardy, Christine W

    2009-01-01

    The aim of the study was to define the extent of current and lifetime smoking by diagnostic groups and suicide risk as reason for admission in a geographically defined psychiatric inpatient cohort. The study used a population-based retrospective chart review. Smoking status and discharge diagnoses for Olmsted County, Minnesota, inpatients aged 18 to 65 admitted for psychiatric hospitalization in 2004 and 2005 were abstracted from the electronic medical record. Diagnostic groups were compared to each other using chi(2) tests and Fisher exact test to analyze smoking status within the inpatient sample with significance defined as P

  18. Tobacco and nicotine delivery product use in a national sample of pregnant women.

    PubMed

    Kurti, Allison N; Redner, Ryan; Lopez, Alexa A; Keith, Diana R; Villanti, Andrea C; Stanton, Cassandra A; Gaalema, Diann E; Bunn, Janice Y; Doogan, Nathan J; Cepeda-Benito, Antonio; Roberts, Megan E; Phillips, Julie; Higgins, Stephen T

    2017-11-01

    Monitoring use of tobacco products among pregnant women is a public health priority, yet few studies in U.S. national samples have been reported on this topic. We examined prevalence and correlates of using cigarettes, e-cigarettes, and other tobacco/nicotine delivery products in a U.S. national sample of pregnant women. Data were obtained from all pregnant women (≥18 years) in the first wave of the Population Assessment of Tobacco and Health (PATH, 2013-2014) Study (N=388). Prevalence of current and prior use of tobacco/nicotine products was examined overall and among current cigarette smokers. Multiple logistic regression was used to examine correlates of use of cigarettes, e-cigarettes, hookah and cigars. Overall prevalence was highest for cigarettes (13.8%), followed by e-cigarettes (4.9%), hookah (2.5%) and cigars (2.3%), and below 1% for all other products. Prevalence of using other tobacco products is much higher among current smokers than the general population, with e-cigarettes (28.5%) most prevalent followed by cigars (14.0%), hookah (12.4%), smokeless (4.7%), snus (4.6%), and pipes (2.1%). Sociodemographic characteristics (poverty, low educational attainment, White race) and past-year externalizing psychiatric symptoms were correlated with current cigarette smoking. In turn, current cigarette smoking and past year illicit drug use were correlated with using e-cigarettes, hookah, and cigars. These results underscore that tobacco/nicotine use during pregnancy extends beyond cigarettes. The results also suggest that use of these other products should be included in routine clinical screening on tobacco use, and the need for more intensive tobacco control and regulatory strategies targeting pregnant women. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Estimating effect of environmental contaminants on women's subfecundity for the MoBa study data with an outcome-dependent sampling scheme

    PubMed Central

    Ding, Jieli; Zhou, Haibo; Liu, Yanyan; Cai, Jianwen; Longnecker, Matthew P.

    2014-01-01

    Motivated by the need from our on-going environmental study in the Norwegian Mother and Child Cohort (MoBa) study, we consider an outcome-dependent sampling (ODS) scheme for failure-time data with censoring. Like the case-cohort design, the ODS design enriches the observed sample by selectively including certain failure subjects. We present an estimated maximum semiparametric empirical likelihood estimation (EMSELE) under the proportional hazards model framework. The asymptotic properties of the proposed estimator were derived. Simulation studies were conducted to evaluate the small-sample performance of our proposed method. Our analyses show that the proposed estimator and design is more efficient than the current default approach and other competing approaches. Applying the proposed approach with the data set from the MoBa study, we found a significant effect of an environmental contaminant on fecundability. PMID:24812419

  20. Trauma and current symptoms of PTSD in a South East London community.

    PubMed

    Frissa, Souci; Hatch, Stephani L; Gazard, Billy; Fear, Nicola T; Hotopf, Matthew

    2013-08-01

    This study aimed to estimate the prevalence of symptoms of post-traumatic stress disorder (PTSD) and its association with traumatic events in a representative sample of an inner city population in the UK. A representative community sample of 1,698 adults, aged 16 years and over, from two south London boroughs were interviewed face to face with structured survey questionnaires. The prevalence of current symptoms of PTSD was 5.5 %. Women were more likely to screen positive (6.4 %) than men (3.6 %), and symptoms of PTSD were high in the unemployed (12.5 %), in those not working because of health reasons (18.2 %) and in the lowest household income group (14.8 %). Most (78.2 %) of the study population had lifetime trauma and more than a third (39.7 %) reported childhood trauma. There was an independent association between childhood as well as lifetime trauma and current symptoms of PTSD and a gradient association between an increase in cumulative traumatic events and the likelihood of reporting symptoms of current PTSD (OR 1.8, 95 % CI (1.6-2.1)). Although we observed the highest prevalence of current symptoms of PTSD in those migrated for asylum or political reason (13.6 %), compared to the non-migrants, the prevalence of exposure to most traumatic life events was higher in the non-migrant group. The present study demonstrates the high prevalence of exposure to trauma in a South East London community and the cumulative effect on current symptoms of PTSD. As PTSD is a condition which is associated with disability and co-morbidity, the association of current PTSD with common adversities in the community should be noted.

  1. Variables Associated With Tic Exacerbation in Children With Chronic Tic Disorders

    PubMed Central

    Himle, Michael B.; Capriotti, Matthew R.; Hayes, Loran P.; Ramanujam, Krishnapriya; Scahill, Lawrence; Sukhodolsky, Denis G.; Wilhelm, Sabine; Deckersbach, Thilo; Peterson, Alan L.; Specht, Matt W.; Walkup, John T.; Chang, Susanna; Piacentini, John

    2014-01-01

    Research has shown that motor and vocal tics fluctuate in frequency, intensity, and form in response to environmental and contextual cues. Behavioral models have proposed that some of the variation in tics may reflect context-dependent interactive learning processes such that once tics are performed, they are influenced by environmental contingencies. The current study describes the results of a function-based assessment of tics (FBAT) from a recently completed study comparing Comprehensive Behavioral Intervention for Tics (CBIT) with supportive psychotherapy. The current study describes the frequency with which antecedent and consequence variables were reported to exacerbate tics and the relationships between these functional variables and sample baseline characteristics, comorbidities, and measures of tic severity. Results showed that tic-exacerbating antecedents and consequences were nearly ubiquitous in a sample of children with chronic tic disorder. In addition, functional variables were related to baseline measures of comorbid internalizing symptoms and specific measures of tic severity. PMID:24778433

  2. Watershed Scale Monitoring and Modeling of Natural Organic Matter (NOM) Generation and Transport

    NASA Astrophysics Data System (ADS)

    Adams, R.; Rees, P. L.; Reckhow, D. A.; Castellon, C. M.

    2006-05-01

    This study describes a coupled watershed scale monitoring campaign, laboratory study, and hydrological modeling study which has been focused on determining the sources and transport mechanisms for Natural Organic Matter (NOM), in a small, mostly forested New England watershed. For some time, the state conservation authorities and a large metropolitan water authority have been concerned that the level of naturally-occurring disinfection byproducts in drinking water supplied by a large surface water reservoir (Watchusett Reservoir, MA) have been increasing over time. The resulting study has attempted to investigate how these compounds, which are mostly formed by the chlorination process at the water treatment plant, are related to NOM precursor compounds which are generated from organic matter and transported by runoff processes in the watershed of the Watchusett Reservoir. The laboratory study measures disinfection byproduct formation potential (DBPFP) through chlorination of raw water samples obtained through field monitoring. Samples are analysed for trihalomethanes (THMs), and haloacetic acids (HAAs). Samples are also analysed for dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254). The samples have been collected from as many components of the hydrological cycle as possible in one of the subcatchments of Watchusett Reservoir (Stillwater River). To date the samples include, stream runoff, water impounded naturally in small ponds by beaver dams, rainfall, snow, throughfall (drainage from tree canopies) and samples pumped from shallow suction lysimeters which were installed to monitor soil water in the riparian zone. The current monitoring program began in late-Summer 2005, however infrequent stream samples are available dating back to 2000 from an earlier research project and water quality monitoring by various regulatory authorities. The monitoring program has been designed to capture as much seasonal variation in water chemistry as possible and also to capture a large spring snowmelt event. The modeling study has been designed to provide a method of estimating the export of NOM and DBPFP precursor compounds by running a series of simple macromodels. One of these models has already been developed for DOC transport based on a variant of the popular TOPMODEL hydrological model. Currently, historical daily streamflow and precipitation data have been used to calibrate the hydrological model, and the results from the current and previous monitoring programs are being used to improve the representation of DOM generation in the model. The ultimate aim is to produce a modeling tool which can be used to investigate changes both in land-use and climate in the watershed and the resulting effects on the export of NOM and DBPFP compounds into the reservoir.

  3. Evaluation of the proposed social anxiety disorder specifier change for DSM-5 in a treatment-seeking sample of anxious youth.

    PubMed

    Kerns, Caroline E; Comer, Jonathan S; Pincus, Donna B; Hofmann, Stefan G

    2013-08-01

    The current proposal for the DSM-5 definition of social anxiety disorder (SAD) is to replace the DSM-IV generalized subtype specifier with one that specifies fears in performance situations only. Relevant evaluations to support this change in youth samples are sparse. The present study examined rates and correlates of the DSM-IV and proposed DSM-5 specifiers in a sample of treatment-seeking children and adolescents with SAD (N = 204). When applying DSM-IV subtypes, 64.2% of the sample was classified as having a generalized subtype of SAD, with the remaining 35.2% classifying as having a nongeneralized subtype SAD. Youth with generalized SAD, relative to those with nongeneralized SAD, were older, had more clinically severe SAD, showed greater depressive symptoms, and were more likely to have a comorbid depressive disorder. No children in the current sample endorsed discrete fear in performance situations only in the absence of fear in other social situations. The present findings call into question the meaningfulness of the proposed changes in treatment-seeking youth with SAD. © 2013 Wiley Periodicals, Inc.

  4. Eddy current nondestructive testing device for measuring variable characteristics of a sample utilizing Walsh functions

    DOEpatents

    Libby, Hugo L.; Hildebrand, Bernard P.

    1978-01-01

    An eddy current testing device for measuring variable characteristics of a sample generates a signal which varies with variations in such characteristics. A signal expander samples at least a portion of this generated signal and expands the sampled signal on a selected basis of square waves or Walsh functions to produce a plurality of signal components representative of the sampled signal. A network combines these components to provide a display of at least one of the characteristics of the sample.

  5. Spontaneous electric current flow during deformation of non-piezoelectric marble samples: an indicator of stress state?

    NASA Astrophysics Data System (ADS)

    Cartwright-Taylor, A. L.; Sammonds, P. R.; Vallianatos, F.

    2016-12-01

    We recorded spontaneous electric current flow in non-piezoelectric Carrara marble samples during triaxial deformation. Mechanical data, ultrasonic velocities and acoustic emissions were acquired simultaneously with electric current to constrain the relationship between electric current flow, differential stress and damage. Under strain-controlled loading, spontaneous electric current signals (nA) were generated and sustained under all conditions tested. In dry samples, a detectable electric current arises only during dilatancy and is correlated with the damage induced by microcracking. Signal variations with confining pressure correspond to microcrack suppression, while variations with strain rate are associated with time-dependent differences in deformation mechanism across the brittle to semi-brittle transition. In the brittle regime, the signal exhibits a precursory change as damage localises and the stress drop accelerates towards failure. This change is particularly distinct at dynamic strain rates. Similar changes are seen in the semi-brittle regime although the signal is more oscillatory in nature. Current flow in dry samples is proportional to stress within 90% of peak stress. In fluid-saturated samples proportionality holds from 40% peak stress, with a significant increase in the rate of current production from 90% peak stress associated with fluid flow during dilatancy. This direct relationship demonstrates that electric current could be used as a proxy for stress, indicating when the rock is reaching the limit of its strength. The experimental power law relationship between electric current and strain rate, which mirrors the power-law creep equation, supports this observation. High-frequency fluctuations of electric current are not normally distributed - they exhibit `heavy-tails'. We model these distributions with q-Gaussian statistics and evolution of the q-parameter during deformation reveals a two-stage precursory anomaly prior to sample failure, consistent with the acoustic emissions b-value and stress intensity evolution as modelled from fracture mechanics. Our findings support the idea that electric currents in the crust can be generated purely from solid state fracture processes and that these currents may reflect the stress state within the damaged rock.

  6. Classification of Parkinson's disease utilizing multi-edit nearest-neighbor and ensemble learning algorithms with speech samples.

    PubMed

    Zhang, He-Hua; Yang, Liuyang; Liu, Yuchuan; Wang, Pin; Yin, Jun; Li, Yongming; Qiu, Mingguo; Zhu, Xueru; Yan, Fang

    2016-11-16

    The use of speech based data in the classification of Parkinson disease (PD) has been shown to provide an effect, non-invasive mode of classification in recent years. Thus, there has been an increased interest in speech pattern analysis methods applicable to Parkinsonism for building predictive tele-diagnosis and tele-monitoring models. One of the obstacles in optimizing classifications is to reduce noise within the collected speech samples, thus ensuring better classification accuracy and stability. While the currently used methods are effect, the ability to invoke instance selection has been seldomly examined. In this study, a PD classification algorithm was proposed and examined that combines a multi-edit-nearest-neighbor (MENN) algorithm and an ensemble learning algorithm. First, the MENN algorithm is applied for selecting optimal training speech samples iteratively, thereby obtaining samples with high separability. Next, an ensemble learning algorithm, random forest (RF) or decorrelated neural network ensembles (DNNE), is used to generate trained samples from the collected training samples. Lastly, the trained ensemble learning algorithms are applied to the test samples for PD classification. This proposed method was examined using a more recently deposited public datasets and compared against other currently used algorithms for validation. Experimental results showed that the proposed algorithm obtained the highest degree of improved classification accuracy (29.44%) compared with the other algorithm that was examined. Furthermore, the MENN algorithm alone was found to improve classification accuracy by as much as 45.72%. Moreover, the proposed algorithm was found to exhibit a higher stability, particularly when combining the MENN and RF algorithms. This study showed that the proposed method could improve PD classification when using speech data and can be applied to future studies seeking to improve PD classification methods.

  7. A study of female Mexican anthropometric measures useful for workstation design in light manufacturing facilities.

    PubMed

    Lavender, S A; Marras, W S; Sabol, R J

    2002-01-01

    As more and more manufacturing is moved to Mexico, the need for anthropometric data describing the Mexican working population becomes more pronounced. The purpose of this study was to obtain data on 21 anthropometric measures that could readily be used to design workplaces in light manufacturing operations. Eighty-seven females, representing 26% of the plant's employees, were sampled. Measurements were made with the shoes on. The mean stature (height) and elbow heights of this sample were 156 cm and 97 cm. Another recently published survey of female factory workers near the U.S. border included 12 anthropometric dimensions. Five of the dimensions were measured in both studies. Hand lengths were nearly identical; however, the 2 to 3 cm differences in the heights measured in the current study are consistent with the incorporation of the footwear in the current measurements. Thus, this study adds to the growing database that can be used when designing these light manufacturing jobs in Mexico.

  8. Tunneling barrier in nanoparticle junctions of La2/3(Ca,Sr)1/3MnO3: Nonlinear current-voltage characteristics

    NASA Astrophysics Data System (ADS)

    Niebieskikwiat, D.; Sánchez, R. D.; Lamas, D. G.; Caneiro, A.; Hueso, L. E.; Rivas, J.

    2003-05-01

    We study the nonlinear current-voltage (I-V) characteristics and analyze the voltage-dependent tunneling conductance in nanoparticles of La2/3A1/3MnO3 (A=Ca, Sr). The powders were prepared by different wet-chemical routes and low calcination temperatures were used to obtain an average particle size D≈30 nm. The data are comprehensively explained in terms of the tunneling picture, which allows one to estimate the height of the grain boundary insulating barrier (φ) for each sample. For constant D, our results show that the sample preparation route is mainly responsible for the value of φ in nanoparticles, while the Coulomb gap in the Coulomb blockade regime is ˜3 times higher for Sr- than for Ca-doping. We also show that a small fraction of the barriers contribute to the nonlinear transport, and the current is mainly carried through low-resistive percolated paths. In addition, despite the different barrier strengths, the low-field magnetoresistance (LFMR) is similar for all samples, implying that φ is not the fundamental parameter determining the LFMR.

  9. Pulsed eddy current differential probe to detect the defects in a stainless steel pipe

    NASA Astrophysics Data System (ADS)

    Angani, C. S.; Park, D. G.; Kim, C. G.; Leela, P.; Kishore, M.; Cheong, Y. M.

    2011-04-01

    Pulsed eddy current (PEC) is an electromagnetic nondestructive technique widely used to detect and quantify the flaws in conducting materials. In the present study a differential Hall-sensor probe which is used in the PEC system has been fabricated for the detection of defects in stainless steel pipelines. The differential probe has an exciting coil with two Hall-sensors. A stainless steel test sample with electrical discharge machining (EDM) notches under different depths of 1-5 mm was made and the sample was laminated by plastic insulation having uniform thickness to simulate the pipelines in nuclear power plants (NPPs). The driving coil in the probe is excited by a rectangular current pulse and the resultant response, which is the difference of the two Hall-sensors, has been detected as the PEC probe signal. The discriminating time domain features of the detected pulse such as peak value and time to zero are used to interpret the experimental results with the defects in the test sample. A feature extraction technique such as spectral power density has been devised to infer the PEC response.

  10. Optical absorption and thermally stimulated depolarization current studies of nickel chloride-doped poly(vinyl alcohol) irradiated with low-level fast neutron doses

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

    Abd El-Kader, F.H.; Ibrahim, S.S.; Attia, G.

    1993-11-15

    The influence of neutron irradiation on ultraviolet/visible absorption and thermally stimulated depolarization current in nickel chloride-poly(vinyl alcohol) (PVA) cast films has been investigated. The spectral measurements indicate the responsibility of the Ni[sup 2][sup +] ion in its octahedral symmetry. Dopant concentrations higher than 10 wt % NiCl[sub 2] are found to make the samples more resistant to a degradation effect caused by neutron irradiation. The thermally stimulated depolarization currents (TSDC) of pure PVA revealed the existence of the glass transition T[sub g] and space charge relaxation peaks, whereas doped-PVA samples show a new sub-T[sub g] relaxation peak. A proposed mechanismmore » is introduced to account for the neutron effects on both glass transition and space charge relaxation peaks. The peak positions, peak currents, and stored charges of the sub-T[sub g] relaxation peak are strongly affected by both the concentration of the dopant and neutron exposure doses.« less

  11. National physical activity surveillance: Users of wearable activity monitors as a potential data source.

    PubMed

    Omura, John D; Carlson, Susan A; Paul, Prabasaj; Watson, Kathleen B; Fulton, Janet E

    2017-03-01

    The objective of this study was to assess usage patterns of wearable activity monitors among US adults and how user characteristics might influence physical activity estimates from this type of sample. We analyzed data on 3367 respondents to the 2015 HealthStyles survey, an annual consumer mail panel survey conducted on a nationwide sample. Approximately 1 in 8 respondents (12.5%) reported currently using a wearable activity monitor. Current use varied by sex, age, and education level. Use increased with physical activity level from 4.3% for inactive adults to 17.4% for active adults. Overall, 49.9% of all adults met the aerobic physical activity guideline, while this prevalence was 69.5% among current activity monitor users. Our findings suggest that current users of wearable activity monitors are not representative of the overall US population. Estimates of physical activity levels using data from wearable activity monitors users may be an overestimate and therefore data from users alone may have a limited role in physical activity surveillance.

  12. Using communication privacy management theory to examine HIV disclosure to sexual partners/spouses among PLHIV in Guangxi.

    PubMed

    Xiao, Zhiwen; Li, Xiaoming; Qiao, Shan; Zhou, Yuejiao; Shen, Zhiyong; Tang, Zhengzhu

    2015-01-01

    The current study employed Communication Privacy Management (CPM) theory to examine the factors associated with disclosure of HIV infection to sexual partners or spouses as well as gender differences in these associations among a sample of people living with HIV (PLHIV) in China. A total of 1254 PLHIV who had 5-16 years old children were invited to answer the questions related to disclosure of HIV infection to sexual partners/spouses. Prevalence of HIV disclosure was reported. Key variables related to CPM theory (such as motivations for disclosure and nondisclosure, HIV-related stigma, and relational factors) were compared between females and males. Logistic regression was employed to determine the factors of influencing whether or not the participants disclosed their HIV status to spouses/partners for the male, the female and the combined samples. Fear of rejection was a significant predictor of HIV nondisclosure for the male, the female and the combined samples. Concern about privacy was a significant factor in not disclosing to sexual partners/spouses only in the male sample. The endorsement of duty to inform/educate was the only motivation factor that was significantly related to HIV disclosure for the three samples. The motivation to establish a close/supportive relationship with intimate partners/spouses was found to be associated with HIV disclosure for the combined and male samples. The current study confirmed the utilities of CPM in studying HIV disclosure to sexual partners/spouse. The findings have theoretical and practical implications for HIV disclosure interventions among PLHIV in Guangxi.

  13. Curation of Samples from Mars

    NASA Astrophysics Data System (ADS)

    Lindstrom, D.; Allen, C.

    One of the strong scientific reasons for returning samples from Mars is to search for evidence of current or past life in the samples. Because of the remote possibility that the samples may contain life forms that are hazardous to the terrestrial biosphere, the National Research Council has recommended that all samples returned from Mars be kept under strict biological containment until tests show that they can safely be released to other laboratories. It is possible that Mars samples may contain only scarce or subtle traces of life or prebiotic chemistry that could readily be overwhelmed by terrestrial contamination. Thus, the facilities used to contain, process, and analyze samples from Mars must have a combination of high-level biocontainment and organic / inorganic chemical cleanliness that is unprecedented. We have been conducting feasibility studies and developing designs for a facility that would be at least as capable as current maximum containment BSL-4 (BioSafety Level 4) laboratories, while simultaneously maintaining cleanliness levels exceeding those of the cleanest electronics manufacturing labs. Unique requirements for the processing of Mars samples have inspired a program to develop handling techniques that are much more precise and reliable than the approach (currently used for lunar samples) of employing gloved human hands in nitrogen-filled gloveboxes. Individual samples from Mars are expected to be much smaller than lunar samples, the total mass of samples returned by each mission being 0.5- 1 kg, compared with many tens of kg of lunar samples returned by each of the six Apollo missions. Smaller samp les require much more of the processing to be done under microscopic observation. In addition, the requirements for cleanliness and high-level containment would be difficult to satisfy while using traditional gloveboxes. JSC has constructed a laboratory to test concepts and technologies important to future sample curation. The Advanced Curation Laboratory includes a new- generation glovebox equipped with a robotic arm to evaluate the usability of robotic and teleoperated systems to perform curatorial tasks. The laboratory also contains equipment for precision cleaning and the measurement of trace organic contamination.

  14. SPRUCE Whole Ecosystem Warming (WEW) Peat Water Content and Temperature Profiles for Experimental Plot Cores Beginning June 2016

    DOE Data Explorer

    Gutknecht, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Kluber, L. A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Schadt, C. W. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

    2016-06-01

    This data set provides the peat water content and peat temperature at time of sampling for peat cores collected before and during the SPRUCE Whole Ecosystem Warming (WEW) study. Cores for the current data set were collected during the following bulk peat sampling events: 13 June 2016 and 23 August 2016. Over time, this dataset will be updated with each new major bulk peat sampling event, and dates/methods will be updated accordingly.

  15. Development of the Ni-based Metallic glassy bipolar plates for Proton Exchange Membrane Fuel Cell (PEMFC)

    NASA Astrophysics Data System (ADS)

    Yamaura, S.; Yokoyama, M.; Kimura, H. M.; Inoue, A.

    2009-01-01

    Alloy optimization in the Ni80-xCrxP16B4 (x = 9-30 at%) alloy system was conducted in order to achieve low Tg, Tx and a large ΔTx. From this study, the Ni65Cr15P16B4 glassy alloy was found to be the optimal alloy. The static and potentiodynamic corrosion behaviours of this alloy were measured. As a result of polarization measurements, it was found that the current density of the non-polished glassy alloy sample was smaller than that of a SUS316L sample. By contrast, the current density of the surface-polished glassy sample was slightly larger than that of the SUS316L sample in the voltage range of 0.3-0.8 V. A bipolar plate was successfully produced by hot-pressing the glassy alloy sheet in a supercooled liquid state. The I-V characteristics of a single cell with the glassy bipolar plates were measured.

  16. The Chlorine Isotopic Composition Of Lunar UrKREEP

    NASA Technical Reports Server (NTRS)

    Barnes, J. J.; Tartese, R.; Anand, M.; McCubbin, F. M.; Neal, C. R.; Franchi, I. A.

    2016-01-01

    Since the long standing paradigm of an anhydrous Moon was challenged there has been a renewed focus on investigating volatiles in a variety of lunar samples. However, the current models for the Moon’s formation have yet to fully account for its thermal evolution in the presence of H2O and other volatiles. When compared to chondritic meteorites and terrestrial rocks, lunar samples have exotic chlorine isotope compositions, which are difficult to explain in light of the abundance and isotopic composition of other volatile species, especially H, and the current estimates for chlorine and H2O in the bulk silicate Moon. In order to better understand the processes involved in giving rise to the heavy chlorine isotope compositions of lunar samples, we have performed a comprehensive in situ high precision study of chlorine isotopes, using NanoSIMS (Nanoscale Secondary Ion Mass Spectrometry) of lunar apatite from a suite of Apollo samples covering a range of geochemical characteristics and petrologic types.

  17. Clustering redshift distributions for the Dark Energy Survey

    NASA Astrophysics Data System (ADS)

    Helsby, Jennifer

    Accurate determination of photometric redshifts and their errors is critical for large scale structure and weak lensing studies for constraining cosmology from deep, wide imaging surveys. Current photometric redshift methods suffer from bias and scatter due to incomplete training sets. Exploiting the clustering between a sample of galaxies for which we have spectroscopic redshifts and a sample of galaxies for which the redshifts are unknown can allow us to reconstruct the true redshift distribution of the unknown sample. Here we use this method in both simulations and early data from the Dark Energy Survey (DES) to determine the true redshift distributions of galaxies in photometric redshift bins. We find that cross-correlating with the spectroscopic samples currently used for training provides a useful test of photometric redshifts and provides reliable estimates of the true redshift distribution in a photometric redshift bin. We discuss the use of the cross-correlation method in validating template- or learning-based approaches to redshift estimation and its future use in Stage IV surveys.

  18. Effect of Rapid Thermal Annealing on the Electrical Characteristics of ZnO Thin-Film Transistors

    NASA Astrophysics Data System (ADS)

    Remashan, Kariyadan; Hwang, Dae-Kue; Park, Seong-Ju; Jang, Jae-Hyung

    2008-04-01

    Thin-film transistors (TFTs) with a bottom-gate configuration were fabricated with an RF magnetron sputtered undoped zinc oxide (ZnO) channel layer and plasma-enhanced chemical vapor deposition (PECVD) grown silicon nitride as a gate dielectric. Postfabrication rapid thermal annealing (RTA) and subsequent nitrous oxide (N2O) plasma treatment were employed to improve the performance of ZnO TFTs in terms of on-current and on/off current ratio. The RTA treatment increases the on-current of the TFT significantly, but it also increases its off-current. The off-current of 2×10-8 A and on/off current ratio of 3×103 obtained after the RTA treatment were improved to 10-10 A and 105, respectively, by the subsequent N2O plasma treatment. The better device performance can be attributed to the reduction of oxygen vacancies at the top region of the channel due to oxygen incorporation from the N2O plasma. X-ray photoelectron spectroscopy (XPS) analysis of the TFT samples showed that the RTA-treated ZnO surface has more oxygen vacancies than as-deposited samples, which results in the increased drain current. The XPS study also showed that the subsequent N2O plasma treatment reduces oxygen vacancies only at the surface of ZnO so that the better off-current and on/off current ratio can be obtained.

  19. Measuring discharge with ADCPs: Inferences from synthetic velocity profiles

    USGS Publications Warehouse

    Rehmann, C.R.; Mueller, D.S.; Oberg, K.A.

    2009-01-01

    Synthetic velocity profiles are used to determine guidelines for sampling discharge with acoustic Doppler current profilers (ADCPs). The analysis allows the effects of instrument characteristics, sampling parameters, and properties of the flow to be studied systematically. For mid-section measurements, the averaging time required for a single profile measurement always exceeded the 40 s usually recommended for velocity measurements, and it increased with increasing sample interval and increasing time scale of the large eddies. Similarly, simulations of transect measurements show that discharge error decreases as the number of large eddies sampled increases. The simulations allow sampling criteria that account for the physics of the flow to be developed. ?? 2009 ASCE.

  20. A Systematic Review and Meta-Analysis of the Effects of Transcranial Direct Current Stimulation (tDCS) Over the Dorsolateral Prefrontal Cortex in Healthy and Neuropsychiatric Samples: Influence of Stimulation Parameters.

    PubMed

    Dedoncker, Josefien; Brunoni, Andre R; Baeken, Chris; Vanderhasselt, Marie-Anne

    2016-01-01

    Research into the effects of transcranial direct current stimulation of the dorsolateral prefrontal cortex on cognitive functioning is increasing rapidly. However, methodological heterogeneity in prefrontal tDCS research is also increasing, particularly in technical stimulation parameters that might influence tDCS effects. To systematically examine the influence of technical stimulation parameters on DLPFC-tDCS effects. We performed a systematic review and meta-analysis of tDCS studies targeting the DLPFC published from the first data available to February 2016. Only single-session, sham-controlled, within-subject studies reporting the effects of tDCS on cognition in healthy controls and neuropsychiatric patients were included. Evaluation of 61 studies showed that after single-session a-tDCS, but not c-tDCS, participants responded faster and more accurately on cognitive tasks. Sub-analyses specified that following a-tDCS, healthy subjects responded faster, while neuropsychiatric patients responded more accurately. Importantly, different stimulation parameters affected a-tDCS effects, but not c-tDCS effects, on accuracy in healthy samples vs. increased current density and density charge resulted in improved accuracy in healthy samples, most prominently in females; for neuropsychiatric patients, task performance during a-tDCS resulted in stronger increases in accuracy rates compared to task performance following a-tDCS. Healthy participants respond faster, but not more accurate on cognitive tasks after a-tDCS. However, increasing the current density and/or charge might be able to enhance response accuracy, particularly in females. In contrast, online task performance leads to greater increases in response accuracy than offline task performance in neuropsychiatric patients. Possible implications and practical recommendations are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. A longitudinal, naturalistic study of U.S. smokers' trial and adoption of snus.

    PubMed

    Burris, Jessica L; Wahlquist, Amy E; Alberg, Anthony J; Cummings, K Michael; Gray, Kevin M; Garrett-Mayer, Elizabeth; Carpenter, Matthew J

    2016-12-01

    To refine public health policy amidst a changing landscape of tobacco products in the United States, it is first necessary to describe fully the nature of smokers' alternative product use. Little research addresses smokers' snus use, and most studies are limited by small samples, cross-sectional designs, and crude outcome measurement. This study sample includes 626 adult US smokers who denied intention to quit in the next month and were randomized to receive free snus during a 6-week sampling period, after which no snus was provided. Participants were then followed for one year. Outcome data were collected via phone. Participants (mean age: 48.7years) were predominately female, White non-Hispanic. Eighty-four percent reported trial of snus. Eleven percent reported purchase (i.e., adoption). Current use declined from 47.1% at the end of the sampling period to 6.5% at the end of follow-up. Frequency and quantity of snus use among current users was low. Among snus users, 79.3% said it functioned as an alternative to smoking and 58.4% said it provided a means of coping with smoking restrictions; options not mutually exclusive. In logistic regressions, men were more likely to report trial (odds ratio [OR]=2.33, p<0.01) and adoption (OR=1.84, p<0.05) than women. Baseline expectations about the nature of snus use also predicted snus outcomes (OR=1.28-1.78, p<0.05). Smokers showed willingness to try snus, but product interest waned over time. Snus as currently marketed is unlikely to play a prominent role in US tobacco control efforts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Photochemical studies in low Earth orbit for organic compounds related to small bodies, Titan and Mars. Current and future facilities.

    NASA Astrophysics Data System (ADS)

    Cottin, H.; Saiagh, K.; Nguyen, D.; Grand, N.; Bénilan, Y.; Cloix, M.; Coll, P.; Gazaux, M.-C.; Fray, N.; Khalaf, D.; Raulin, F.; Stalort, F.; Carrasco, N.; Szopa, C.; Chaput, D.; Bertrand, M.; Westall, F.; Mattioda, A.; Quinn, R.; Ricco, A.; Santos, O.; Baratta, G. A.; Strazzulla, G.; Palumbo, M. E.; Le Postollec, A.; Dobrijevic, M.; Coussot, G.; Vigier, F.; Vandenabeele-Trambouze, O.; Incerti, S.; Berger, T.

    2015-01-01

    The study of the evolution of organic matter subjected to space conditions, and more specifically to solar photons in the vacuum ultraviolet range (120-200 nm) has been undertaken in low Earth Orbit since the 90's, and implemented on various space platforms. The most recent exposure facilities are BIOPAN outside the Russian automatic capsules FOTON, and EXPOSE-E & -R (1&2) outside the International Space Station. They allow the photolysis of many different samples simultaneously, and provide us with valuable data about the formation and evolution of organic matter in the Solar System (meteorites, comets, Titan's atmosphere, the Martian surface...) and in the Interstellar Medium. They have been used by European teams in the recent past(ORGANIC on BIOPAN V-FOTON M2 and UVolution on BIOPAN VI-FOTON M3, PROCESS on EXPOSE-E, AMINO and ORGANICS on EXPOSE-R), and a new EXPOSE set is currently exposed outside the ISS (PSS on EXPOSE-R2). These existing tools are very valuable; however, they have significant limitations that limit their capabilities and scientific return. One of the most critical issues for current studies is the lack of any in-situ analysis of the evolution of the samples as a function of time. Only two measurements are available for the experiment: one before and one after the exposure. A significant step forward has been achieved with the O/OREOS NASA nanosatellite and the OREOcube ESA project with onboard UV-visible measurements. However, for organic samples, following the evolution of the samples would be more informative and provide greater insight with infrared measurements, which display specific patterns characteristic of major organic functionalities in the mid-infrared range (4000-1000 cm-1).

  3. Studies of current-perpendicular-to-plane magnetoresistance (CPP-MR) and current-induced magnetization switching (CIMS)

    NASA Astrophysics Data System (ADS)

    Kurt, Huseyin

    2005-08-01

    We present two CPP-MR studies of spin-valves based upon ferromagnetic/nonmagnetic/ferromagnetic (F/N/F) trilayers. We measure the spin-diffusion lengths of N = Pd, Pt, and Au at 4.2K, and both the specific resistances (sample area A times resistance R) and spin-memory-loss of N/Cu interfaces. Pd, Pt and Au are of special device interest because they give perpendicular anisotropy when sandwiching very thin Co layers. Comparing our spin-memory-loss data at Pd/Cu and Pt/Cu interfaces with older data for Nb/Cu and W/Cu gives insight into the importance of spin-orbit coupling in producing such loss. We reproduce and extend prior studies by Eid of 'magnetic activity' at the interface of Co and N-metals (or combinations of N-metals), when the other side of the N-metal contacts a superconductor (S). Our data suggest that magnetic activity may require strong spin-flipping at the N/S interface. We present five studies of a new phenomenon, CIMS, in F1/N/F2 trilayers, with F1 a thick 'polarizing' layer and F2 a thin 'switching' layer. In all prior studies of CIMS, positive current caused the magnetization of F2 to switch from parallel (P) to anti-parallel (AP) to that of F1- 'normal' switching. By judicious addition of impurities to F-metals, we are able to controllably produce both 'normal' and 'inverse' switching- where positive current switches the magnetization of F2 from AP to P to that of F1. In the samples studied, whether the switching is normal or inverse is set by the 'net polarization' produced by F1 and is independent of the properties of F2. As scattering in the bulk of F1 and F2 is essential to producing our results, these results cannot be described by ballistic models, which allow scattering only at interfaces. Most CIMS experiments use Cu as the N-layer due to its low resistivity and long spin-diffusion length. We show that Ag and Au have low enough resistivities and long enough spin-diffusion lengths to be useful alternatives to Cu for some devices. While most technical applications of CIMS require low switching currents, some, like read-heads, require high switching currents. We show that use of a synthetic antiferromagnet can increase the switching current. Manschot et al. recently predicted that the positive critical current for switching from P to AP could be reduced by up to a factor of five by using asymmetric current leads. In magnetically uncoupled samples, we find that highly asymmetric current leads do not significantly reduce the switching current. A CIMS equation given by Katine et al. predicts that lowering the demagnetization field should reduce the switching current. To test this prediction, we compare switching currents for Co/Au/Co(t)/Au nanopillars with t = 1 to 4 nm (where the easy axis should be normal to the layer planes at least for t = 1 and 2 nm) with those for Co/Cu/Co(t)/Au nanopillars (where the easy axis should be in the layer planes). We do not find significant differences in switching currents for the two systems.

  4. Detection of Non-Photochemical Superoxide in Coastal and Open Ocean Seawater: Particulate Versus Dissolved Sources

    NASA Astrophysics Data System (ADS)

    Roe, K. L.; Rand, T.; Hansel, C. M.; Voelker, B. M.

    2016-02-01

    Superoxide radical (O2-) could have a significant effect on marine metal redox chemistry, but little data exists on its marine concentrations. In this study, we measured superoxide steady-state concentrations in both filtered and unfiltered samples collected near the California coast and at Station ALOHA. Particle-generated superoxide, defined as the difference between unfiltered and filtered concentrations, ranged from undetectable to 0.019 nM at Station ALOHA and from undetectable to 0.052 nM in samples from the southern California Current. We also show that a transient superoxide signal is generated during filtering, an artifact that may have affected previously reported concentrations of particle-generated superoxide in the ocean. High concentrations of superoxide (range) were measured in filtered samples from ALOHA station and the California Current, raising concerns about possible sources of background signals. Further study of background signals revealed that some superoxide production occurs even in artificial seawater and very aged filtered seawater samples, and that a small additional background signal is generated as the sample travels from the container to the flow cell where it is mixed with reagent for CL analysis. However, filtered seawater samples collected from the Scripps Pier had significantly higher superoxide production rates than those measured in artificial seawater, and production rates in unfiltered samples were no higher than those in filtered samples. Therefore, production by dissolved sources was the dominant non-photochemical source of superoxide in these samples. Production rates decreased in the presence of DTPA, suggesting involvement of metal ions in superoxide production. Laboratory experiments with natural organic matter (NOM) indicate that superoxide formation occurs during oxidation of reduced moieties of NOM by oxygen.

  5. Doping effect of nano-Ho{sub 2}O{sub 3} and naphthalene in MgB{sub 2} superconductor prepared by powder-in-sealed-tube method

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

    Hansdah, J. S.; Sarun, P. M., E-mail: sarun.res@gmail.com

    2015-03-21

    The effect on crystal structure, critical temperature (T{sub C}), and critical current density (J{sub C}) of bulk MgB{sub 2} doped with nano-Ho{sub 2}O{sub 3} and naphthalene was studied. Among all the samples studied, the sample doped with 2.5 wt. % nano-Ho{sub 2}O{sub 3} have shown the best field dependent critical current density [J{sub C}(H)], i.e., 0.77 × 10{sup 5 }A/cm{sup 2} at 2 T and 10 K. While naphthalene doped MgB{sub 2} sample has shown the least J{sub C}(H) characteristics. The improved J{sub C}(H) characteristics in the nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples are attributed to improved flux pinning properties due to the formation ofmore » HoB{sub 4} and in naphthalene doped MgB{sub 2} samples. The slight lower T{sub C} value (37.01 K) in naphthalene doped samples is attributed to the occurrence of lattice defect by the substitution of carbon at boron site of MgB{sub 2} superconductor. Lower ΔT{sub C} value implies the lesser anisotropy in all the synthesized samples. The flux pinning force density (F{sub P}/F{sub Pmax}) curves are theoretically analyzed using Dew-Hughes model. The result revealed that point pinning is the dominant pinning mechanism for nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples, while, surface and grain boundary pinning become dominant with increasing naphthalene addition in nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples.« less

  6. How Do Deep Saline Aquifer Microbial Communities Respond to Supercritical CO2 Injection?

    NASA Astrophysics Data System (ADS)

    Mu, A.; Billman-Jacobe, H.; Boreham, C.; Schacht, U.; Moreau, J. W.

    2011-12-01

    Carbon Capture and Storage (CCS) is currently seen as a viable strategy for mitigating anthropogenic carbon dioxide pollution. The Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) is currently conducting a field experiment in the Otway Basin (Australia) studying residual gas saturation in the water-saturated reservoir of the Paaratte Formation. As part of this study, a suite of pre-CO2 injection water samples were collected from approximately 1400 meters depth (60°C, 13.8 MPa) via an in situ sampling system. The in situ sampling system isolates aquifer water from sources of contamination while maintaining the formation pressure. Whole community DNA was extracted from these samples to investigate the prokaryotic biodiversity of the saline Paaratte aquifer (EC = 1509.6 uS/cm). Bioinformatic analysis of preliminary 16S ribosomal gene data revealed Thermincola, Acinetobacter, Sphingobium, and Dechloromonas amongst the closest related genera to environmental clone sequences obtained from a subset of pre-CO2 injection groundwater samples. Epifluorescent microscopy with 4',6-diamidino-2-phenylindole (DAPI) highlighted an abundance of filamentous cells ranging from 5 to 45 μM. Efforts are currently directed towards utilising a high throughput sequencing approach to capture an exhaustive profile of the microbial diversity of the Paaratte aquifer CO2 injection site, and to understand better the response of in situ microbial populations to the injection of large volumes (e.g. many kilotonnes) of supercritical CO2 (sc-CO2). Sequencing results will be used to direct cultivation efforts towards enrichment of a CO2-tolerant microorganism. Understanding the microbial response to sc-CO2 is an integral aspect of carbon dioxide storage, for which very little information exists in the literature. This study aims to elucidate molecular mechanisms, through genomic and cultivation-based methods, for CO2 tolerance with the prospect of engineering biofilms to enhance trapping of CO2 in saline aquifers.

  7. Development and Psychometric Evaluation of the Reasons for Living—Older Adults Scale: A Suicide Risk Assessment Inventory

    PubMed Central

    Edelstein, Barry A.; Heisel, Marnin J.; McKee, Deborah R.; Martin, Ronald R.; Koven, Lesley P.; Duberstein, Paul R.; Britton, Peter C.

    2009-01-01

    Purpose: The purposes of these studies were to develop and initially evaluate the psychometric properties of the Reasons for Living Scale—Older Adult version (RFL-OA), an older adults version of a measure designed to assess reasons for living among individuals at risk for suicide. Design and Methods: Two studies are reported. Study 1 involved instrument development with 106 community-dwelling older adults, and initial psychometric evaluation with a second sample of 119 community-dwelling older adults. Study 2 evaluated the psychometric properties of the RFL-OA in a clinical sample. One hundred eighty-one mental health patients 50 years or older completed the RFL-OA and measures of depression, suicide ideation at the current time and at the worst point in one's life, and current mental status and physical functioning. Results: Strong psychometric properties were demonstrated for the RFL-OA, with high internal consistency (Cronbach's alpha coefficient). Convergent validity was evidenced by negative associations among RFL-OA scores and measures of depression and suicide ideation. RFL-OA scores predicted current and worst-episode suicide ideation above and beyond current depression. Discriminant validity was evidenced with measures of current mental status and physical functioning. Criterion-related validity was also demonstrated with respect to lifetime history of suicidal behavior. Implications: These findings provide preliminary support for the validity and reliability of the RFL-OA. The findings also support the potential value of attending to reasons for living during clinical treatment with depressed older adults and others at risk for suicide. PMID:19546114

  8. Citizenship and withdrawal in the workplace: relationship between organizational citizenship behavior, intention to leave current job and intention to leave the organization.

    PubMed

    Paillé, Pascal; Grima, François

    2011-01-01

    This study investigates the relationship between organizational citizenship behavior (OCB) and employee intention to leave the organization and current job using a sample of French employees. A survey was sent to 1,200 alumni of a business school in France. Participation in the study was voluntary. The participants were 355 working adults with French citizenship. This paper provides several interesting findings. While no relationship was found between altruism and intention to leave both the organization and the current job, sportsmanship, civic virtue and helping others emerged as the strongest predictors of intention to leave the organization and intention to leave the current job. Results are discussed.

  9. Preliminary results of oxygen isotope ratio measurement with a particle-gamma coincidence method

    NASA Astrophysics Data System (ADS)

    Borysiuk, Maciek; Kristiansson, Per; Ros, Linus; Abdel, Nassem S.; Elfman, Mikael; Nilsson, Charlotta; Pallon, Jan

    2015-04-01

    The possibility to study variations in the oxygen isotopic ratio with photon tagged nuclear reaction analysis (pNRA) is evaluated in the current work. The experiment described in the article was performed at Lund Ion Beam Analysis Facility (LIBAF) with a 2 MeV deuteron beam. Isotopic fractionation of light elements such as carbon, oxygen and nitrogen is the basis of many analytical tools in hydrology, geology, paleobiology and paleogeology. IBA methods provide one possible tool for measurement of isotopic content. During this experimental run we focused on measurement of the oxygen isotopic ratio. The measurement of stable isotopes of oxygen has a number of applications; the particular one driving the current investigation belongs to the field of astrogeology and specifically evaluation of fossil extraterrestrial material. There are three stable isotopes of oxygen: 16O, 17O and 18O. We procured samples highly enriched with all three isotopes. Isotopes 16O and 18O were easily detected in the enriched samples, but no significant signal from 17O was detected in the same samples. The measured yield was too low to detect 18O in a sample with natural abundances of oxygen isotopes, at least in the current experimental setup, but the spectral line from the reaction with 16O was clearly visible.

  10. Single-centre study of the diagnostic performance of plasma metanephrines with seated sampling for the diagnosis of phaeochromocytoma/paraganglioma.

    PubMed

    Boot, Christopher; Toole, Barry; Johnson, Sarah J; Ball, Stephen; Neely, Dermot

    2017-01-01

    Background Measurement of plasma metanephrines is regarded as one of the best screening tests for phaeochromocytoma/paraganglioma. Current guidelines recommend that samples are ideally collected in the supine position after 30 min rest and interpreted using supine reference ranges, in order to optimize the diagnostic performance of the test. Current practice in our centre is to collect samples for plasma metanephrines from seated patients. The aim of the study was to determine, if seated sampling for plasma metanephrines provides acceptable diagnostic performance in our centre. Methods Clinical and laboratory data of 113 patients, gathered over a four-year period 2010-2014, were reviewed. All had undergone preoperative plasma metanephrines measurement and had postoperative histopathology confirmation or exclusion of phaeochromocytoma/paraganglioma. Results Of 113 patients included in the study, 40 had a histological diagnosis of phaeochromocytoma/paraganglioma. The remaining 73 patients had an alternative adrenal pathology. The diagnostic sensitivity of normetanephrine or metanephrine above the upper limit of our in-house seated reference range was 93%. However, excluding three cases of paraganglioma determined clinically and biochemically to be non-functional raised the sensitivity to 100%. Diagnostic specificity was 90%. Applying published supine reference ranges made no difference to diagnostic sensitivity in this group of patients but decreased diagnostic specificity to 75%. Conclusions While these data are derived from a relatively small study population, they demonstrate acceptable diagnostic performance for seated plasma metanephrines as a screening test for phaeochromocytoma/paraganglioma. These data highlight a high diagnostic sensitivity for plasma metanephrines with seated sampling in our centre.

  11. The Motivation to Serve Others: Exploring Relations to Career Development

    ERIC Educational Resources Information Center

    Duffy, Ryan D.; Raque-Bogdan, Trisha L.

    2010-01-01

    The current study explored the relation between service motivation, or the desire to serve others through one's future career, and vocational outcomes across two studies. In the first study, using a sample of 225 undergraduate students, an instrument was developed to measure service motivation that demonstrated convergent and discriminant…

  12. Measuring University Students' Approaches to Learning Statistics: An Invariance Study

    ERIC Educational Resources Information Center

    Chiesi, Francesca; Primi, Caterina; Bilgin, Ayse Aysin; Lopez, Maria Virginia; del Carmen Fabrizio, Maria; Gozlu, Sitki; Tuan, Nguyen Minh

    2016-01-01

    The aim of the current study was to provide evidence that an abbreviated version of the Approaches and Study Skills Inventory for Students (ASSIST) was invariant across different languages and educational contexts in measuring university students' learning approaches to statistics. Data were collected on samples of university students attending…

  13. Variance Estimation, Design Effects, and Sample Size Calculations for Respondent-Driven Sampling

    PubMed Central

    2006-01-01

    Hidden populations, such as injection drug users and sex workers, are central to a number of public health problems. However, because of the nature of these groups, it is difficult to collect accurate information about them, and this difficulty complicates disease prevention efforts. A recently developed statistical approach called respondent-driven sampling improves our ability to study hidden populations by allowing researchers to make unbiased estimates of the prevalence of certain traits in these populations. Yet, not enough is known about the sample-to-sample variability of these prevalence estimates. In this paper, we present a bootstrap method for constructing confidence intervals around respondent-driven sampling estimates and demonstrate in simulations that it outperforms the naive method currently in use. We also use simulations and real data to estimate the design effects for respondent-driven sampling in a number of situations. We conclude with practical advice about the power calculations that are needed to determine the appropriate sample size for a study using respondent-driven sampling. In general, we recommend a sample size twice as large as would be needed under simple random sampling. PMID:16937083

  14. Influence of Sample Size of Polymer Materials on Aging Characteristics in the Salt Fog Test

    NASA Astrophysics Data System (ADS)

    Otsubo, Masahisa; Anami, Naoya; Yamashita, Seiji; Honda, Chikahisa; Takenouchi, Osamu; Hashimoto, Yousuke

    Polymer insulators have been used in worldwide because of some superior properties; light weight, high mechanical strength, good hydrophobicity etc., as compared with porcelain insulators. In this paper, effect of sample size on the aging characteristics in the salt fog test is examined. Leakage current was measured by using 100 MHz AD board or 100 MHz digital oscilloscope and separated three components as conductive current, corona discharge current and dry band arc discharge current by using FFT and the current differential method newly proposed. Each component cumulative charge was estimated automatically by a personal computer. As the results, when the sample size increased under the same average applied electric field, the peak values of leakage current and each component current increased. Especially, the cumulative charges and the arc discharge length of dry band arc discharge increased remarkably with the increase of gap length.

  15. Stabilization of Neem Oil Biodiesel with Corn Silk Extract during Long-term Storage.

    PubMed

    Ali, Rehab Farouk M; El-Anany, Ayman M

    2017-02-01

    The current study aimed to evaluate the antioxidant efficiency of different extracts of corn silk. In addition, the impact of corn silk extract on oxidative stability of neem biodiesel during storage was studied. The highest phenolics, DPPH radical scavenging and reducing power activities were recorded for methanol-water extract. The longest oxidation stability (10 h) was observed for biodiesel samples blended with 1000 ppm of corn silk extract (CSE). At the end of storage period the induction time of biodiesel samples mixed with 1000 ppm of CSE or butylated hydroxytoluene (BHT) were about 6.72 and 5.63 times as high as in biodiesel samples without antioxidants. Biodiesel samples blended with 1000 ppm of CSE had the lowest acidity at the end of storage period. Peroxide value of biodiesel samples containing 1000 ppm of CSE was about 4.28 times as low as in control sample without antioxidants.

  16. Improving magnetic properties of MgB2 bulk superconductors by synthetic engine oil treatment

    NASA Astrophysics Data System (ADS)

    Taylan Koparan, E.; Savaskan, B.; Yanmaz, E.

    2016-08-01

    The present study focuses on the effects of standby time of the MgB2 samples immersed in synthetic engine oil on the critical current density (Jc(H)), magnetic field dependence of the pinning force density fp(b) and Tc performances of MgB2 bulk superconductors. Synthetic engine oil was used as a product which is cheap and a rich carbon source. Manufactured MgB2 pellet samples were immersed at different standby time of 30 min, 120 min, 300 min and 1440 min in synthetic engine oil after the first heating process. Finally, MgB2 samples immersed in synthetic engine oil were sintered at 1000 °C and kept for 15 min in Ar atmosphere. The critical current density of all of MgB2 samples immersed at different standby time in engine oil in whole field range was better than that of the pure MgB2 sample because of the number of the pinning centers. The MgB2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. The Jc value for the pure sample is 2.0 × 103 A/cm2, whereas for the MgB2 sample immersed at 300 min standby time in engine oil the Jc is enhanced to 4.8 × 103A/cm2 at 5 K and 3 T. The superconducting transition temperature (Tc) did not change with the increasing standby time of the samples in synthetic engine oil at all. The best diamagnetic property was obtained from the sample which kept in synthetic engine oil for 300 min. Synthetic engine oil treatment results in remarkable improvement of the critical current density and pinning force performances of MgB2 superconductors. It was found that all MgB2 samples have a different pinning property at different measuring temperatures. Using synthetic engine oil as a product which is cheap and a rich carbon source in MgB2 bulk superconductors makes MgB2 samples immersed in synthetic engine oil a good candidate for industrial applications.

  17. Astromaterials Acquisition and Curation Office (KT) Overview

    NASA Technical Reports Server (NTRS)

    Allen, Carlton

    2014-01-01

    The Astromaterials Acquisition and Curation Office has the unique responsibility to curate NASA's extraterrestrial samples - from past and forthcoming missions - into the indefinite future. Currently, curation includes documentation, preservation, physical security, preparation, and distribution of samples from the Moon, asteroids, comets, the solar wind, and the planet Mars. Each of these sample sets has a unique history and comes from a unique environment. The curation laboratories and procedures developed over 40 years have proven both necessary and sufficient to serve the evolving needs of a worldwide research community. A new generation of sample return missions to destinations across the solar system is being planned and proposed. The curators are developing the tools and techniques to meet the challenges of these new samples. Extraterrestrial samples pose unique curation requirements. These samples were formed and exist under conditions strikingly different from those on the Earth's surface. Terrestrial contamination would destroy much of the scientific significance of extraterrestrial materials. To preserve the research value of these precious samples, contamination must be minimized, understood, and documented. In addition, the samples must be preserved - as far as possible - from physical and chemical alteration. The elaborate curation facilities at JSC were designed and constructed, and have been operated for many years, to keep sample contamination and alteration to a minimum. Currently, JSC curates seven collections of extraterrestrial samples: (a)) Lunar rocks and soils collected by the Apollo astronauts, (b) Meteorites collected on dedicated expeditions to Antarctica, (c) Cosmic dust collected by high-altitude NASA aircraft,t (d) Solar wind atoms collected by the Genesis spacecraft, (e) Comet particles collected by the Stardust spacecraft, (f) Interstellar dust particles collected by the Stardust spacecraft, and (g) Asteroid soil particles collected by the Japan Aerospace Exploration Agency (JAXA) Hayabusa spacecraft Each of these sample sets has a unique history and comes from a unique environment. We have developed specialized laboratories and practices over many years to preserve and protect the samples, not only for current research but for studies that may be carried out in the indefinite future.

  18. Identification of fecal contamination sources in water using host-associated markers.

    PubMed

    Krentz, Corinne A; Prystajecky, Natalie; Isaac-Renton, Judith

    2013-03-01

    In British Columbia, Canada, drinking water is tested for total coliforms and Escherichia coli, but there is currently no routine follow-up testing to investigate fecal contamination sources in samples that test positive for indicator bacteria. Reliable microbial source tracking (MST) tools to rapidly test water samples for multiple fecal contamination markers simultaneously are currently lacking. The objectives of this study were (i) to develop a qualitative MST tool to identify fecal contamination from different host groups, and (ii) to evaluate the MST tool using water samples with evidence of fecal contamination. Singleplex and multiplex polymerase chain reaction (PCR) were used to test (i) water from polluted sites and (ii) raw and drinking water samples for presence of bacterial genetic markers associated with feces from humans, cattle, seagulls, pigs, chickens, and geese. The multiplex MST assay correctly identified suspected contamination sources in contaminated waterways, demonstrating that this test may have utility for heavily contaminated sites. Most raw and drinking water samples analyzed using singleplex PCR contained at least one host-associated marker. Singleplex PCR was capable of detecting host-associated markers in small sample volumes and is therefore a promising tool to further analyze water samples submitted for routine testing and provide information useful for water quality management.

  19. Factor Structure of the Psychopathic Personality Inventory (PPI): Findings from a Large Incarcerated Sample

    PubMed Central

    Neumann, Craig S.; Malterer, Melanie B.; Newman, Joseph P.

    2010-01-01

    Recent exploratory factor analysis (EFA) of the Psychopathic Personality Inventory (PPI; Lilienfeld, 1990) with a community sample suggested that the PPI subscales may be comprised of two higher-order factors (Benning et al., 2003). However, little research has examined the PPI structure in offenders. The current study attempted to replicate the Benning et al. two-factor solution using a large (N=1224) incarcerated male sample. Confirmatory factor analysis (CFA) of this model with the full sample resulted in poor model fit. Next, to identify a factor solution that would summarize the offender data, EFA was conducted using a split-half of the total sample, followed by an attempt to replicate the EFA solution via CFA with the other split-half sample. Using the recommendations of Prooijen and van der Kloot (2001) for recovering EFA solutions, model fit results provided some evidence that the EFA solution could be recovered via CFA. However, this model involved extensive cross-loadings of the subscales across three factors, suggesting item overlap across PPI subscales. In sum, the two-factor solution reported by Benning et al. (2003) was not a viable model for the current sample of offenders, and additional research is needed to elucidate the latent structure of the PPI. PMID:18557694

  20. Instrument developments for chemical and physical characterization, mapping and sampling of extreme environments (Antarctic sub ice environment)

    NASA Astrophysics Data System (ADS)

    Vogel, S. W.; Powell, R. D.; Griffith, I.; Lawson, T.; Schiraga, S.; Ludlam, G.; Oen, J.

    2009-12-01

    A number of instrumentation is currently under development designed to enable the study of subglacial environments in Antarctica through narrow kilometer long boreholes. Instrumentation includes: - slim line Sub-Ice ROV (SIR), - Geochemical Instrumentation Package for Sub Ice Environments (GIPSIE) to study geochemical fluxes in water and across the sediment water interface (CO2, CH4, dO, NH4, NO3, Si, PO4, pH, redox, T, H2, HS, O2, N2O, CTD, particle size, turbidity, color camera, current meter and automated water sampler) with real-time telemetry for targeted sampling, - long term energy-balance mooring system, - active source slide hammer sediment corer, and - integration of a current sensor into the ITP profiler. The instrumentation design is modular and suitable for remote operated as well as autonomous long-term deployment. Of interest to the broader science community is the development of the GIPSIE and efforts to document the effect of sample recovery from depth on the sample chemistry. The GIPSIE is a geochemical instrumentation package with life stream telemetry, allowing for user controlled targeted sampling of water column and the water sediment interphase for chemical and biological work based on actual measurements and not a preprogrammed automated system. The porewater profiler (pH, redox, T, H2, HS, O2, N2O) can penetrate the upper 50 cm of sediment and penetration is documented with real time video. Associated with GIPSIE is an on-site lab set-up, utilizing a set of identical sensors. Comparison between the insitu measurements and measurements taken onsite directly after samples are recovered from depth permits assessing the effect of sample recovery on water and sediment core chemistry. Sample recovery related changes are mainly caused by changes in the pressure temperature field and exposure of samples to atmospheric conditions. Exposure of anaerobic samples to oxygen is here a specific concern. Recovery from depth effects in generally pH, solubility of gases and nutrients and can initiate complex chemical reaction, the product of which is later measured in the lab. Further information on the instrument developments can be found at http://jove.geol.niu.edu/faculty/svogel/Technology/Technology-index.html

  1. Desert Research and Technology Studies Exposure of Lotus Coated Electrodynamic Shield Samples

    NASA Technical Reports Server (NTRS)

    Rodriquez, Marcello; Peters, Wanda C.; Straka, Sharon A.; Jones, Craig B.

    2011-01-01

    The Lotus dust mitigation coating and the electrodynamic shield (EDS) are two new technologies currently being developed by NASA as countermeasures for addressing dust accumulation for long-duration human space exploration. These combined technologies were chosen by the Habitation Demonstration Unit (HDU) program for desert dust exposure at the Desert Research and Technologies Studies (D-RaTS) test site in Arizona. Characterization of these samples was performed prior to, during and post D-RaTS exposure.

  2. The Red Pill: Social Studies, Media Texts, and Literacies

    ERIC Educational Resources Information Center

    Walker, Trenia L.

    2010-01-01

    This article explores the use of media texts in contemporary high school social studies classrooms. Much of the current research regarding media education in social studies classes has focused on history classes and has centered on small idealized samples of both teachers and students. This study, based on the observations conducted in eight…

  3. Associations with E-cigarette use among Asian American and Pacific Islander young adults in California.

    PubMed

    Maglalang, Dale Dagar; Brown-Johnson, Cati; Prochaska, Judith J

    2016-12-01

    With attention to the rapidly growing market of electronic nicotine delivery systems (ENDS/e-cigarettes) and the fastest growing US ethnic minority group, the current study explored associations between awareness, perceived risks, and use of ENDS among Asian American and Pacific Islander (AAPI) young adults. AAPI young adults (ages 18-25) in California were recruited via social media, college classes, listservs for AAPI-serving non-profits, and snowball sampling to complete an anonymous survey between 2014 and 2015. The sample (N = 501) was 57% women, 15% LGBTQIA; with a mean age of 21; 26% foreign-born; identifying as Filipino (29%), Chinese (24%), Vietnamese (14%), mixed-AAPI heritage (13%), or 21% other. Nearly half the sample (44%) reported ever ENDS use; 11% were current users. Current ENDS use was twofold greater for: Filipino and Vietnamese compared to Chinese respondents; men versus women; LGBTQIA-identified respondents; those vocationally trained; and employed. Awareness of ENDS from peers/friends was most common and was associated with ever though not current ENDS use. Most respondents perceived ENDS as harmful (62%); low compared to high risk perception was associated with a three-fold greater likelihood of ever use and six-fold greater likelihood of current use. Popular flavors were fruit (49%, e.g., lychee, taro) and candy/sweets (26%). Current users viewed ENDS as a healthier alternative or quit aid for conventional cigarettes (42%); recreation/social use (33%) also was common. Findings indicate ENDS visibility among AAPI young adults in California with affinity for flavors and many engaging in trial and current use for harm reduction and recreational/social aims.

  4. Pathological buying and partnership status.

    PubMed

    Müller, Astrid; de Zwaan, Martina; Mitchell, James E; Zimmermann, Tanja

    2016-05-30

    This pilot study investigated the partnership status and the level of pathological buying (PB) in 157 female patients with PB and 1153 women from a German population-based sample. Slightly more than half of both samples were currently living with a partner. The results suggest a protective effect of being in a couple relationship in the representative sample. In contrast, having a partner was not related to the severity of PB among patients. Future studies should address the question of whether the characteristics and quality of partnership have an impact on the severity and course of PB, and vice versa. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Advanced Curation of Current and Future Extraterrestrial Samples

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.

    2013-01-01

    Curation of extraterrestrial samples is the critical interface between sample return missions and the international research community. Curation includes documentation, preservation, preparation, and distribution of samples. The current collections of extraterrestrial samples include: Lunar rocks / soils collected by the Apollo astronauts Meteorites, including samples of asteroids, the Moon, and Mars "Cosmic dust" (asteroid and comet particles) collected by high-altitude aircraft Solar wind atoms collected by the Genesis spacecraft Comet particles collected by the Stardust spacecraft Interstellar dust collected by the Stardust spacecraft Asteroid particles collected by the Hayabusa spacecraft These samples were formed in environments strikingly different from that on Earth. Terrestrial contamination can destroy much of the scientific significance of many extraterrestrial materials. In order to preserve the research value of these precious samples, contamination must be minimized, understood, and documented. In addition the samples must be preserved - as far as possible - from physical and chemical alteration. In 2011 NASA selected the OSIRIS-REx mission, designed to return samples from the primitive asteroid 1999 RQ36 (Bennu). JAXA will sample C-class asteroid 1999 JU3 with the Hayabusa-2 mission. ESA is considering the near-Earth asteroid sample return mission Marco Polo-R. The Decadal Survey listed the first lander in a Mars sample return campaign as its highest priority flagship-class mission, with sample return from the South Pole-Aitken basin and the surface of a comet among additional top priorities. The latest NASA budget proposal includes a mission to capture a 5-10 m asteroid and return it to the vicinity of the Moon as a target for future sampling. Samples, tools, containers, and contamination witness materials from any of these missions carry unique requirements for acquisition and curation. Some of these requirements represent significant advances over methods currently used. New analytical and screening techniques will increase the value of current sample collections. Improved web-based tools will make information on all samples more accessible to researchers and the public. Advanced curation of current and future extraterrestrial samples includes: Contamination Control - inorganic / organic Temperature of preservation - subfreezing / cryogenic Non-destructive preliminary examination - X-ray tomography / XRF mapping / Raman mapping Microscopic samples - handling / sectioning / transport Special samples - unopened lunar cores Informatics - online catalogs / community-based characterization.

  6. Cognitive and family correlates of current suicidal ideation in children with bipolar disorder.

    PubMed

    Weinstein, Sally M; Van Meter, Anna; Katz, Andrea C; Peters, Amy T; West, Amy E

    2015-03-01

    Suicidality among youth with bipolar disorder is an extreme, but largely unaddressed, public health problem. The current study examined the psychosocial characteristics differentiating youth with varying severities of suicidal ideation that may dictate targets for suicide prevention interventions. Participants included 72 youth aged 7-13 (M=9.19, SD=1.61) with DSM-IV-TR bipolar I, II, or NOS and a parent/caregiver. Current suicidal ideation and correlates were assessed at intake, including: demographics and clinical factors (diagnosis, symptom severity, psychiatric comorbidity); child factors (cognitive risk and quality of life); and family factors (parenting stress, family cohesion, and family rigidity). Current ideation was prevalent in this young sample: 41% endorsed any ideation, and 31% endorsed active forms. Depression symptoms, quality of life, hopelessness, self-esteem, and family rigidity differentiated youth with increasing ideation severity. Separate logistic regressions examined all significant child- and family-level factors, controlling for demographic and clinical variables. Greater family rigidity and lower self-esteem remained significant predictors of current planful ideation. Diagnosis, index episode, comorbidity, and mania severity did not differentiate non-ideators from those with current ideation. Limitations include the small sample to examine low base-rate severe ideation, cross-sectional analyses and generalizability of findings beyond the outpatient clinical sample. Findings underscore the importance of assessing and addressing suicidality in preadolescent youth with bipolar disorder, before youth progress to more severe suicidal behaviors. Results also highlight child self-esteem and family rigidity as key treatment targets to reduce suicide risk in pediatric bipolar disorder. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Comparison of anamnestic responses to rabies vaccination in dogs and cats with current and out-of-date vaccination status.

    PubMed

    Moore, Michael C; Davis, Rolan D; Kang, Qing; Vahl, Christopher I; Wallace, Ryan M; Hanlon, Cathleen A; Mosier, Derek A

    2015-01-15

    To compare anamnestic antibody responses of dogs and cats with current versus out-of-date vaccination status. Cross-sectional study. 74 dogs and 33 cats. Serum samples were obtained from dogs and cats that had been exposed to rabies and brought to a veterinarian for proactive serologic monitoring or that had been brought to a veterinarian for booster rabies vaccination. Blood samples were collected on the day of initial evaluation (day 0) and then again 5 to 15 days later. On day 0, a rabies vaccine was administered according to label recommendations. Paired serum samples were analyzed for antirabies antibodies by means of a rapid fluorescent focus inhibition test. All animals had an antirabies antibody titer ≥ 0.5 IU/mL 5 to 15 days after booster vaccination. Dogs with an out-of-date vaccination status had a higher median increase in titer, higher median fold increase in titer, and higher median titer following booster vaccination, compared with dogs with current vaccination status. Most (26/33) cats, regardless of rabies vaccination status, had a titer ≥ 12 IU/mL 5 to 15 days after booster vaccination. Results indicated that dogs with out-of-date vaccination status were not inferior in their antibody response following booster rabies vaccination, compared with dogs with current vaccination status. Findings supported immediate booster vaccination followed by observation for 45 days of dogs and cats with an out-of-date vaccination status that are exposed to rabies, as is the current practice for dogs and cats with current vaccination status.

  8. Cognitive and Family Correlates of Current Suicidal Ideation in Children with Bipolar Disorder

    PubMed Central

    Weinstein, Sally M.; Van Meter, Anna; Katz, Andrea C.; Peters, Amy T.; West, Amy E.

    2014-01-01

    Background Suicidality among youth with bipolar disorder is an extreme, but largely unaddressed, public health problem. The current study examined the psychosocial characteristics differentiating youth with varying severities of suicidal ideation that may dictate targets for suicide prevention interventions. Methods Participants included 72 youth aged 7–13 (M = 9.19, SD = 1.61) with DSM-IV-TR bipolar I, II, or NOS and a parent/caregiver. Current suicidal ideation and correlates were assessed at intake, including: demographics and clinical factors (diagnosis, symptom severity, psychiatric comorbidity); child factors (cognitive risk and quality of life); and family factors (parenting stress, family cohesion, and family rigidity). Results Current ideation was prevalent in this young sample: 41% endorsed any ideation, and 31% endorsed active forms. Depression symptoms, quality of life, hopelessness, self-esteem, and family rigidity differentiated youth with increasing ideation severity. Separate logistic regressions examined all significant child- and family-level factors, controlling for demographic and clinical variables. Greater family rigidity and lower self-esteem remained significant predictors of current planful ideation. Diagnosis, index episode, comorbidity, and mania severity did not differentiate non-ideators from those with current ideation. Limitations Limitations include the small sample to examine low base-rate severe ideation, cross-sectional analyses and generalizability of findings beyond the outpatient clinical sample. Conclusions Findings underscore the importance of assessing and addressing suicidality in preadolescent youth with bipolar disorder, before youth progress to more severe suicidal behaviors. Results also highlight child self-esteem and family rigidity as key treatment targets to reduce suicide risk in pediatric bipolar disorder. PMID:25462390

  9. Perinatal Illicit Drug and Marijuana Use: An Observational Study Examining Prevalence, Screening, and Disclosure

    PubMed Central

    Chang, Judy C.; Holland, Cynthia L.; Tarr, Jill A.; Rubio, Doris; Rodriguez, Keri L.; Kraemer, Kevin L.; Day, Nancy; Arnold, Robert M.

    2016-01-01

    Purpose To assess use, screening, and disclosure of perinatal marijuana and other illicit drugs during first obstetric visits. Design Observational study that qualitatively assesses provider screening and patient disclosure of substance use. Setting Study sites were five urban outpatient prenatal clinics and practices located in Pittsburgh, Pennsylvania. Participants Pregnant patients and obstetric providers were recruited as participants. Methods We audio recorded patient-provider conversations during first obstetric visits and obtained patient urine samples for drug analyses. Audio recordings were reviewed for provider screening and patient disclosure of illicit drug use. Urine analyses were compared with audio recordings to determine disclosure. Results Four hundred and twenty-two pregnant patients provided complete audio recordings and urine samples for analyses. Providers asked about illicit drug use in 81% of the visits. One hundred twenty-three patients (29%) disclosed any current or past illicit drug use; 48 patients (11%) disclosed current use of marijuana while pregnant. One hundred and forty-five samples (34%) tested positive for one or more substances; marijuana was most commonly detected (N = 114, 27%). Of patients who tested positive for any substance, 66 (46%) did not disclose any use; only 36% of patients who tested positive for marijuana disclosed current use. Conclusion Although marijuana is illegal in Pennsylvania, a high proportion of pregnant patients used marijuana, with many not disclosing use to their obstetric care providers. (Am J Health Promot 0000; 00[0]:000–000.) PMID:26559718

  10. Factor Structure and Psychometric Properties of the Multidimensional Anxiety Scale for Children in an African American Adolescent Sample

    ERIC Educational Resources Information Center

    Kingery, Julie Newman; Ginsburg, Golda S.; Burstein, Marcy

    2009-01-01

    The current study examined the psychometric properties and factor structure of the Multidimensional Anxiety Scale for Children (MASC) among a community sample of 118 African American students (58 females; ages 14-19 years; mean age = 15.79) in an urban, parochial high school. Adolescents completed the MASC and several other self-report measures of…

  11. The Association between Cannabis Use and Motivation and Intentions to Quit Tobacco within a Sample of Australian Socioeconomically Disadvantaged Smokers

    ERIC Educational Resources Information Center

    Twyman, Laura; Bonevski, Billie; Paul, Christine; Kay-Lambkin, Frances J.; Bryant, Jamie; Oldmeadow, C.; Palazzi, K.; Guillaumier, A.

    2016-01-01

    This study aimed to (i) describe concurrent and simultaneous tobacco and cannabis use and (ii) investigate the association between cannabis use and motivation and intentions to quit tobacco in a sample of socioeconomically disadvantaged smokers. A cross-sectional survey was conducted in 2013 and 2014 with current tobacco smokers receiving aid from…

  12. Patterns of Physical and Relational Aggression in a School-Based Sample of Boys and Girls

    ERIC Educational Resources Information Center

    Crapanzano, Ann Marie; Frick, Paul J.; Terranova, Andrew M.

    2010-01-01

    The current study investigated the patterns of aggressive behavior displayed in a sample of 282 students in the 4th through 7th grades (M age = 11.28; SD = 1.82). Using cluster analyses, two distinct patterns of physical aggression emerged for both boys and girls with one aggressive cluster showing mild levels of reactive aggression and one group…

  13. Characteristics of Internet Gamblers among a Sample of Students at a Large, Public University in Southwestern United States

    ERIC Educational Resources Information Center

    Shead, N. Will; Derevensky, Jeffrey L.; Fong, Timothy W.; Gupta, Rina

    2012-01-01

    There is a current lack of descriptive information on college students who gamble on the Internet. With the increasing popularity of Internet gambling, this study aimed to better understand the profile of Internet gamblers among a sample of college students. Of 909 students at the University of California-Los Angeles who completed an online…

  14. The Relations between Children's Reading Comprehension, Working Memory, Language Skills and Components of Reading Decoding in a Normal Sample

    ERIC Educational Resources Information Center

    Goff, Deborah A.; Pratt, Chris; Ong, Ben

    2005-01-01

    The primary aim of the current study was to identify the strongest independent predictors of reading comprehension using word reading, language and memory variables in a normal sample of 180 children in grades 3-5, with a range of word reading skills. It was hypothesized that orthographic processing, receptive vocabulary and verbal working memory…

  15. Prevalence and Mental Health Outcomes of Homicide Survivors in a Representative US Sample of Adolescents: Data from the 2005 National Survey of Adolescents

    ERIC Educational Resources Information Center

    Rheingold, Alyssa A.; Zinzow, Heidi; Hawkins, Alesia; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2012-01-01

    Background: Each homicide leaves behind several friends and family members, or homicide survivors. However, limited information is available on the impact of homicide on adolescent survivors. The purpose of the current study was to identify the prevalence of homicide survivorship and to determine mental health outcomes within a sample of US…

  16. Assessment of a Rotating Time Sampling Procedure: Implications for Interobserver Agreement and Response Measurement

    ERIC Educational Resources Information Center

    Becraft, Jessica L.; Borrero, John C.; Davis, Barbara J.; Mendres-Smith, Amber E.

    2016-01-01

    The current study was designed to evaluate a rotating momentary time sampling (MTS) data collection system. A rotating MTS system has been used to measure activity preferences of preschoolers but not to collect data on responses that vary in duration and frequency (e.g., talking). We collected data on talking for 10 preschoolers using a 5-s MTS…

  17. A Psychometric Analysis of the Positive and Negative Affect Schedule for Children-Parent Version in a School Sample

    ERIC Educational Resources Information Center

    Ebesutani, Chad; Okamura, Kelsie; Higa-McMillan, Charmaine; Chorpita, Bruce F.

    2011-01-01

    The current study was the 1st to examine the psychometric properties of the Positive and Negative Affect Schedule for Children-Parent Version (PANAS-C-P) using a large school-based sample of children and adolescents ages 8 to 18 (N = 606). Confirmatory factor analysis supported a 2-factor (correlated) model of positive affect (PA) and negative…

  18. The Association between Body Dissatisfaction and Depression: An Examination of the Moderating Effects of Gender, Age, and Weight Status in a Sample of Chinese Adolescents

    ERIC Educational Resources Information Center

    Chen, Gui; Guo, Guiping; Gong, Jingbo; Xiao, Shuiyuan

    2015-01-01

    The current study investigated the moderating effects of gender, age, and weight status on the relationship between body dissatisfaction and depression among adolescents. Data were collected on body dissatisfaction, depression, and demographic characteristics from a convenience sample of 1,101 adolescents (505 girls, 596 boys). The relationship…

  19. Effect of nanosized Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} on the transport critical current density of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} superconductor

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

    Hafiz, M.; Abd-Shukor, R.

    2014-09-03

    The effects of nano-sized Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} addition on the superconducting and transport properties of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} (Bi-2223) in bulk form has been investigated. Bi-2223 superconductor was fabricated using co-precipitation method and 0.01 – 0.05 wt% of Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles with average size of 20 nm were added into the samples. The critical temperature (T{sub c}) and critical current density (J{sub c}) of the samples were measured by using the four-point probe method, while the phase formation and microstructure of the samples were examined using x-ray diffraction and SEM respectively.more » It was found that J{sub c} of all samples added with Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} were higher than non-added sample, with x = 0.01 wt. % sample showing the highest J{sub c}. This study showed that small addition of nano-Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} can effectively enhance the transport critical current density in Bi-2223 superconductor.« less

  20. Molecular and serological detection of bovine babesiosis in Indonesia.

    PubMed

    Guswanto, Azirwan; Allamanda, Puttik; Mariamah, Euis Siti; Sodirun, Sodirun; Wibowo, Putut Eko; Indrayani, Liliek; Nugroho, Rudi Harso; Wirata, I Ketut; Jannah, Nur; Dias, Lepsi Putri; Wirawan, Hadi Purnama; Yanto, Rochmadi; Tuvshintulga, Bumduuren; Sivakumar, Thillaiampalam; Yokoyama, Naoaki; Igarashi, Ikuo

    2017-11-06

    Bovine babesiosis, mainly caused by Babesia bovis and B. bigemina, is a huge threat to the livestock industry. In Indonesia, the current distribution of the disease is unknown due to a lack of scientific study. In the present study, 487 blood samples were collected from cattle with different breeding and age groups in a broad geographical area across the archipelago. The presence of antibodies and current infections of B. bovis and B. bigemina were determined using enzyme-linked immunosorbent assay (ELISA), immunochromatographic test (ICT), and nested PCR (nPCR) targeting B. bovis SBP-4 and B. bigemina RAP-1a genes. Sequence analysis was performed to the amplicon of B. bovis SBP-4, B. bigemina RAP-1a, and internal transcribed spacer (ITS) region of ribosomal RNA of both Babesia species. In total, B. bovis positives were detected by ELISA, single-ICT, dual-ICT and nPCR in 340 (69.8%), 317 (65.1%), 307 (63.0%) and 247 (50.7%) samples, respectively. For B. bigemina, the positive samples were detected in 134 (27.5%), 130 (26.7%), 127 (26.1%) and 93 (19.1%), respectively. Furthermore, mixed infections were found in 125 (25.7%), 113 (23.2%), 109 (22.4%) and 52 (10.7%) samples, respectively, which occurred only by chance and were not influenced by additional factors. The obtained nucleotide sequences of B. bovis SBP-4 and B. bigemina RAP-1a genes showed a high homology with other isolates from different countries. Further nucleotide sequence analysis using ITS region showed a great genetic diversity of B. bovis isolates among sampling locations; a lower diversity was found in B. bigemina ITS isolates. These data revealed the current distribution of B. bovis and B. bigemina infection in cattle in Indonesia. The rate of infection varied among sampling locations, cattle breeds and age groups. Furthermore, B. bovis ITS isolates from Indonesia were found to be more genetically diverse than B. bigemina ITS isolates. The data presented in this study are necessary to develop an effective strategy for controlling the disease in the country.

  1. Immunoassay screening in urine for synthetic cannabinoids - an evaluation of the diagnostic efficiency.

    PubMed

    Franz, Florian; Angerer, Verena; Jechle, Hanna; Pegoro, Melanie; Ertl, Harald; Weinfurtner, Georg; Janele, David; Schlögl, Christian; Friedl, Matthias; Gerl, Stefan; Mielke, Reinhard; Zehnle, Ralf; Wagner, Matthias; Moosmann, Bjoern; Auwärter, Volker

    2017-08-28

    The abuse of synthetic cannabinoids (SCs) as presumed legal alternative to cannabis poses a great risk to public health. For economic reasons many laboratories use immunoassays (IAs) to screen for these substances in urine. However, the structural diversity and high potency of these designer drugs places high demands on IAs regarding cross-reactivity of the antibodies used and detection limits. Two retrospective studies were carried out in order to evaluate the capability of two homogenous enzyme IAs for the detection of currently prevalent SCs in authentic urine samples. Urine samples were analyzed utilizing a 'JWH-018' kit and a 'UR-144' kit. The IA results were confirmed by an up-to-date liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) screening method covering metabolites of 45 SCs. The first study (n=549) showed an 8% prevalence of SCs use (LC-MS/MS analysis) among inpatients of forensic-psychiatric clinics, whereas all samples were tested negative by the IAs. In a second study (n=200) the combined application of both IAs led to a sensitivity of 2% and a diagnostic accuracy of 51% when applying the recommended IA cut-offs. Overall, 10 different currently prevalent SCs were detected in this population. The results can be explained by an insufficient cross-reactivity of the antibodies towards current SCs in combination with relatively high detection limits of the IAs. In light of the presented study data it is strongly recommended not to rely on the evaluated IA tests for SCs in clinical or forensic settings. For IA kits of other providers similar results can be expected.

  2. Bidirectional Relationships Between Parenting Processes and Deviance in a Sample of Inner-City African American Youth

    PubMed Central

    Harris, Charlene; Vazsonyi, Alexander T.; Bolland, John M.

    2016-01-01

    The current study assessed for bidirectional relationships among supportive parenting (knowledge), negative parenting (permissiveness), and deviance in a sample (N = 5,325) of poor, inner-city African American youth from the Mobile Youth Survey (MYS) over 4 years. Cross-lagged path analysis provided evidence of significant bidirectional paths among parenting processes (knowledge and permissiveness) and deviance over time. Follow-up multigroup tests provided only modest evidence of dissimilar relationships by sex and by developmental periods. The findings improve our understanding of developmental changes between parenting behaviors and deviance during adolescence and extended current research of the bidirectionality of parent and child relationships among inner-city African American youth. PMID:28316460

  3. Health Warnings, Smoking Rules, and Smoking Status: A Cross-National Comparison of Turkey and the United States.

    PubMed

    Wintemberg, Jenna; Yu, Mansoo; Caman, Ozge Karadag

    2018-05-12

    This study aimed to compare the prevalence of smoking status (i.e., current, former and never) between the United States and Turkey in terms of age and gender, and examine how smoking rules and health warnings are associated with smoking status within and between the two countries. The study used data from the 2012-2013 National Adult Tobacco Survey (U.S. sample, N = 60,196) and the 2012 Global Adult Tobacco Survey (Turkey sample, N = 9,581). SAS PROC SURVEYLOGISTIC with a weighted variable was used to examine the associations between demographics (age, gender and education), smoking rules, health warnings, and smoking status within and between the two countries. There was an 18% current smoking prevalence among U.S. sample, compared to 27% of the Turkey sample. The U.S. sample had a higher rate of former smoking compared to the Turkey sample (25% vs. 22%). In both countries, being older and male gender predicted former smoking while being younger and female gender predicted never smoking. Having seen a health warning, and not allowing smoking in the vehicle and home positively predicted former and never smoking status. Higher education predicted both smoking statuses in the U.S. only. It is important to work with partners particularly in low- and middle-income countries (e.g., Turkey) to combat the global tobacco epidemic. In both counties, cessation endeavors should emphasize a comprehensive understanding of smoking status in terms of smoking rules in personal spaces and health warnings.

  4. The Changing Epidemiology of Autism

    ERIC Educational Resources Information Center

    Fombonne, Eric

    2005-01-01

    This article reviews epidemiological studies of autism and related disorders. Study designs and sample characteristics are summarized. Currently, conservative prevalence estimates are: 13/10000 for autistic disorder, 21/10000 for pervasive developmental disorders not otherwise specified, 2.6/10000 for Asperger disorder, and 2/100000 for childhood…

  5. A 7-year follow-up study on the mental health of North Korean defectors in South Korea.

    PubMed

    Jeon, Woo-Taek; Eom, Jin-Sup; Min, Sung Kil

    2013-02-01

    This study was conducted to describe the relationship of past trauma and current stress on the mental health of North Korean (NK) defectors living in South Korea 7 years after a baseline assessment. Of the 200 who participated in the initial study, 106 participated in follow-up. Previous data regarding past traumatic events experienced in North Korea and during defection, past posttraumatic stress disorder (PTSD), and their current stress levels were correlated with the participants' current mental health status including depression, anxiety, and PTSD. The rate of PTSD in the sample and the scores on the PTSD symptom scale decreased significantly from the baseline. The participants' current mental health was negatively related to previous traumatic experiences in North Korea and past symptoms of PTSD, but unrelated to previous trauma experienced during defection. In addition, although current mental health was negatively related to only current culture-related stress, it was unrelated to the level of current ordinary life stress. The results of this study suggest that PTSD symptoms decreased during the 7 years between assessments, and that current culture-related stress is the most important variable related to the mental health of NK defectors living in South Korea. Copyright © 2013 International Society for Traumatic Stress Studies.

  6. In Search of Emerging Same-Sex Sexuality: Romantic Attractions at Age 13 Years.

    PubMed

    Li, Gu; Hines, Melissa

    2016-10-01

    Sex-typed behavior in childhood is significantly related to sexual orientation in adulthood. In addition, same-sex attractions in early adolescence are more non-exclusive than in adulthood and can differ from later same-sex orientations. However, little research has focused on romantic attractions as they emerge during early adolescence. Drawing a sample from the Avon Longitudinal Study of Parents and Children (197 girls, 204 boys), the current study examined whether same-sex romantic attractions at age 13 years were exclusive, and whether they were predicted by sex-typed behavior at age 3.5 years. No young adolescents in this sample reported exclusive same-sex attractions, and increased same-sex attractions were not significantly related to reduced other-sex sexualities. Childhood sex-typed behavior did not significantly predict early same-sex attractions, suggesting that early same-sex attractions differ from later same-sex orientations. The current study highlights the importance of studying the development of sexuality beginning prior to adulthood.

  7. Nightmare Themes: An Online Study of Most Recent Nightmares and Childhood Nightmares.

    PubMed

    Schredl, Michael; Göritz, Anja S

    2018-03-15

    Even though the common diagnostic criteria (ICSD-3, DSM-5) acknowledge that nightmares do not only contain anxiety/fear (definition of the ICD-10) but also other emotions such as grief, disgust, and anger, the definition of a nightmare still focuses on threats to survival, security, or physical integrity. However, empirical studies on nightmare content in larger samples are scarce. The current study elicited 1,216 of the most recent nightmares including childhood nightmares of a population-based sample. The findings show that nightmares encompass a diversity of different topics, being chased, physical aggression, including death/injury of close persons. Infrequent themes like being the aggressor and suicide are of special interest as they might be related to waking-life psychopathology. The variety of nightmare topics clearly indicate that current definitions of nightmare content are too narrow. Future studies should look into nightmare content of persons in whom nightmare disorder has been diagnosed. © 2018 American Academy of Sleep Medicine.

  8. Genetic diversity of Mycobacterium tuberculosis strains isolated in Algeria: Results of spoligotyping.

    PubMed

    Ifticene, Malika; Kaïdi, Saïd; Khechiba, Mesbah-Mounir; Yala, Djamel; Boulahbal, Fadila

    2015-12-01

    Molecular typing tools, including spoligotyping, are currently widely used in the monitoring and study of the dynamics of tuberculosis epidemics. A study of the molecular profile of a sample of 129 Myobacterium tuberculosis strains isolated during 2011 was carried out in the National Reference Laboratory for Tuberculosis and Mycobacteria at the Pasteur Institute of Algeria. This sample was selected at random from a set of 350 strains isolated from tuberculosis patients from central and eastern areas of the country. Genotypic analysis helped to clarify the frequencies of the different genotypes in the current study population: H family, 29%; LAM family, 26%; T family, 25%; S family, 5%, and other genomic families, including orphan strains, 15%. The study of strains isolated between January and December 2011 has allowed insight into the frequency of different genomic families and the importance of existing clusters in the population of central and eastern Algeria. Copyright © 2015 Asian African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  9. Brain Stimulation in Alzheimer's Disease.

    PubMed

    Chang, Chun-Hung; Lane, Hsien-Yuan; Lin, Chieh-Hsin

    2018-01-01

    Brain stimulation techniques can modulate cognitive functions in many neuropsychiatric diseases. Pilot studies have shown promising effects of brain stimulations on Alzheimer's disease (AD). Brain stimulations can be categorized into non-invasive brain stimulation (NIBS) and invasive brain stimulation (IBS). IBS includes deep brain stimulation (DBS), and invasive vagus nerve stimulation (VNS), whereas NIBS includes transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), electroconvulsive treatment (ECT), magnetic seizure therapy (MST), cranial electrostimulation (CES), and non-invasive VNS. We reviewed the cutting-edge research on these brain stimulation techniques and discussed their therapeutic effects on AD. Both IBS and NIBS may have potential to be developed as novel treatments for AD; however, mixed findings may result from different study designs, patients selection, population, or samples sizes. Therefore, the efficacy of NIBS and IBS in AD remains uncertain, and needs to be further investigated. Moreover, more standardized study designs with larger sample sizes and longitudinal follow-up are warranted for establishing a structural guide for future studies and clinical application.

  10. On the search for the chiral anomaly in Weyl semimetals: the negative longitudinal magnetoresistance

    NASA Astrophysics Data System (ADS)

    dos Reis, R. D.; Ajeesh, M. O.; Kumar, N.; Arnold, F.; Shekhar, C.; Naumann, M.; Schmidt, M.; Nicklas, M.; Hassinger, E.

    2016-08-01

    Recently, the existence of massless chiral (Weyl) fermions has been postulated in a class of semi-metals with a non-trivial energy dispersion. These materials are now commonly dubbed Weyl semi-metals (WSM). One predicted property of Weyl fermions is the chiral or Adler-Bell-Jackiw anomaly, a chirality imbalance in the presence of parallel magnetic and electric fields. In WSM, it is expected to induce a negative longitudinal magnetoresistance (MR). Here, we present experimental evidence that the observation of the chiral anomaly can be hindered by an effect called ‘current jetting’. This effect also leads to a strong apparent negative longitudinal MR, but it is characterized by a highly non-uniform current distribution inside the sample. It appears in materials possessing a large field-induced anisotropy of the resistivity tensor, such as almost compensated high-mobility semimetals due to the orbital effect. In case of a non-homogeneous current injection, the potential distribution is strongly distorted in the sample. As a consequence, an experimentally measured potential difference is not proportional to the intrinsic resistance. Our results on the MR of the Weyl semimetal candidate materials NbP, NbAs, TaAs, and TaP exhibit distinct signatures of an inhomogeneous current distribution, such as a field-induced ‘zero resistance’ and a strong dependence of the ‘measured resistance’ on the position, shape, and type of the voltage and current contacts on the sample. A misalignment between the current and the magnetic-field directions can even induce a ‘negative resistance’. Finite-element simulations of the potential distribution inside the sample, using typical resistance anisotropies, are in good agreement with the experimental findings. Our study demonstrates that great care must be taken before interpreting measurements of a negative longitudinal MR as evidence for the chiral anomaly in putative Weyl semimetals.

  11. Pituitary gland volumes in bipolar disorder.

    PubMed

    Clark, Ian A; Mackay, Clare E; Goodwin, Guy M

    2014-12-01

    Bipolar disorder has been associated with increased Hypothalamic-Pituitary-Adrenal axis function. The mechanism is not well understood, but there may be associated increases in pituitary gland volume (PGV) and these small increases may be functionally significant. However, research investigating PGV in bipolar disorder reports mixed results. The aim of the current study was twofold. First, to assess PGV in two novel samples of patients with bipolar disorder and matched healthy controls. Second, to perform a meta-analysis comparing PGV across a larger sample of patients and matched controls. Sample 1 consisted of 23 established patients and 32 matched controls. Sample 2 consisted of 39 medication-naïve patients and 42 matched controls. PGV was measured on structural MRI scans. Seven further studies were identified comparing PGV between patients and matched controls (total n; 244 patients, 308 controls). Both novel samples showed a small (approximately 20mm(3) or 4%), but non-significant, increase in PGV in patients. Combining the two novel samples showed a significant association of age and PGV. Meta-analysis showed a trend towards a larger pituitary gland in patients (effect size: .23, CI: -.14, .59). While results suggest a possible small difference in pituitary gland volume between patients and matched controls, larger mega-analyses with sample sizes greater even than those used in the current meta-analysis are still required. There is a small but potentially functionally significant increase in PGV in patients with bipolar disorder compared to controls. Results demonstrate the difficulty of finding potentially important but small effects in functional brain disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Variance of discharge estimates sampled using acoustic Doppler current profilers from moving boats

    USGS Publications Warehouse

    Garcia, Carlos M.; Tarrab, Leticia; Oberg, Kevin; Szupiany, Ricardo; Cantero, Mariano I.

    2012-01-01

    This paper presents a model for quantifying the random errors (i.e., variance) of acoustic Doppler current profiler (ADCP) discharge measurements from moving boats for different sampling times. The model focuses on the random processes in the sampled flow field and has been developed using statistical methods currently available for uncertainty analysis of velocity time series. Analysis of field data collected using ADCP from moving boats from three natural rivers of varying sizes and flow conditions shows that, even though the estimate of the integral time scale of the actual turbulent flow field is larger than the sampling interval, the integral time scale of the sampled flow field is on the order of the sampling interval. Thus, an equation for computing the variance error in discharge measurements associated with different sampling times, assuming uncorrelated flow fields is appropriate. The approach is used to help define optimal sampling strategies by choosing the exposure time required for ADCPs to accurately measure flow discharge.

  13. Study on the performance of 2.6 μm In0.83Ga0.17As detector with different etch gases

    NASA Astrophysics Data System (ADS)

    Li, Ping; Tang, Hengjing; Li, Tao; Li, Xue; Shao, Xiumei; Ma, Yingjie; Gong, Haimei

    2017-09-01

    In order to obtain a low-damage recipe in the ICP processing, ICP-induced damage using Cl2/CH4 etch gases in extended wavelength In0.83Ga0.17As detector materials was studied in this paper. The effect of ICP etching on In0.83Ga0.17As samples was characterized qualitatively by the photoluminescence (PL) technology. The etch damage of In0.83Ga0.17As samples was characterized quantitatively by the Transmission Line Model (TLM), current voltage (IV) measurement, signal and noise testing and the Fourier Transform Infrared Spectroscopy (FTIR) technologies. The results showed that the Cl2/CH4 etching processing could lead better detector performance than that Cl2/N2, such as a larger square resistance, a lower dark current, a lower noise voltage and a higher peak detectivity. The lower PL signal intensity and lower dark current could be attributed to the hydrogen decomposed by the CH4 etch gases in the plasma etching process. These hydrogen particles generated non-radiative recombination centers in inner materials to weaken the PL intensity and passivated dangling bond at the surface to reduce the dark current. The larger square resistance resulted from the lower etch damage. The lower dark current meant that the detectors have less dangling bonds and leakage channels.

  14. [Study on the method for the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current arc full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES)].

    PubMed

    Hao, Zhi-hong; Yao, Jian-zhen; Tang, Rui-ling; Zhang, Xue-mei; Li, Wen-ge; Zhang, Qin

    2015-02-01

    The method for the determmation of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current are full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES) was established. Direct current are full spectrum direct reading atomic emission spectrometer with a large area of solid-state detectors has functions of full spectrum direct reading and real-time background correction. The new electrodes and new buffer recipe were proposed in this paper, and have applied for national patent. Suitable analytical line pairs, back ground correcting points of elements and the internal standard method were selected, and Ge was used as internal standard. Multistage currents were selected in the research on current program, and each current set different holding time to ensure that each element has a good signal to noise ratio. Continuous rising current mode selected can effectively eliminate the splash of the sample. Argon as shielding gas can eliminate CN band generating and reduce spectral background, also plays a role in stabilizing the are, and argon flow 3.5 L x min(-1) was selected. Evaporation curve of each element was made, and it was concluded that the evaporation behavior of each element is consistent, and combined with the effects of different spectrographic times on the intensity and background, the spectrographic time of 35s was selected. In this paper, national standards substances were selected as a standard series, and the standard series includes different nature and different content of standard substances which meet the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples. In the optimum experimental conditions, the detection limits for B, Mo, Ag, Sn and Pb are 1.1, 0.09, 0.01, 0.41, and 0.56 microg x g(-1) respectively, and the precisions (RSD, n=12) for B, Mo, Ag, Sn and Pb are 4.57%-7.63%, 5.14%-7.75%, 5.48%-12.30%, 3.97%-10.46%, and 4.26%-9.21% respectively. The analytical accuracy was validated by national standards and the results are in agreement with certified values. The method is simple, rapid, is an advanced analytical method for the determination of trace amounts of geochemical samples' boron, molybdenum, silver, tin and lead, and has a certain practicality.

  15. Performance of ARCHITECT HCV core antigen test with specimens from US plasma donors and injecting drug users.

    PubMed

    Mixson-Hayden, Tonya; Dawson, George J; Teshale, Eyasu; Le, Thao; Cheng, Kevin; Drobeniuc, Jan; Ward, John; Kamili, Saleem

    2015-05-01

    Hepatitis C virus (HCV) core antigen is a serological marker of current HCV infection. The aim of this study was mainly to evaluate the performance characteristics of the ARCHITECT HCV core antigen assay with specimens from US plasma donors and injecting drug users. A total of 551 serum and plasma samples with known anti-HCV and HCV RNA status were tested for HCV core antigen using the Abbott ARCHITECT HCV core antigen test. HCV core antigen was detectable in 100% of US plasma donor samples collected during the pre-seroconversion phase of infection (anti-HCV negative/HCV RNA positive). Overall sensitivity of the HCV core antigen assay was 88.9-94.3% in samples collected after seroconversion. The correlation between HCV core antigen and HCV RNA titers was 0.959. HCV core antigen testing may be reliably used to identify current HCV infection. Published by Elsevier B.V.

  16. A preliminary study of the statistical analyses and sampling strategies associated with the integration of remote sensing capabilities into the current agricultural crop forecasting system

    NASA Technical Reports Server (NTRS)

    Sand, F.; Christie, R.

    1975-01-01

    Extending the crop survey application of remote sensing from small experimental regions to state and national levels requires that a sample of agricultural fields be chosen for remote sensing of crop acreage, and that a statistical estimate be formulated with measurable characteristics. The critical requirements for the success of the application are reviewed in this report. The problem of sampling in the presence of cloud cover is discussed. Integration of remotely sensed information about crops into current agricultural crop forecasting systems is treated on the basis of the USDA multiple frame survey concepts, with an assumed addition of a new frame derived from remote sensing. Evolution of a crop forecasting system which utilizes LANDSAT and future remote sensing systems is projected for the 1975-1990 time frame.

  17. Evidence for the Propositions of the Interpersonal Theory of Suicide Among a Military Sample.

    PubMed

    Silva, Caroline; Hagan, Christopher R; Rogers, Megan L; Chiurliza, Bruno; Podlogar, Matthew C; Hom, Melanie A; Tzoneva, Mirela; Lim, Ingrid C; Joiner, Thomas E

    2017-06-01

    Although the interpersonal theory of suicide may explain the elevated suicide risk among military service members, past explorations have been equivocal. This study aimed to investigate the propositions of the interpersonal theory in a sample of U.S. Army recruiters. Participants (N = 3,428) completed self-report measures assessing the interpersonal theory's constructs (i.e., thwarted belongingness (TB), perceived burdensomeness (PB), acquired capability for suicide), current suicidal ideation, agitation, and insomnia. History of depression was obtained from medical records. Hierarchical multiple regression analyses revealed that the interaction between TB and PB was associated with current suicidal ideation, controlling for depression, agitation, and insomnia. This effect was especially notable among those with high capability for suicide. Findings provide support for the interpersonal theory in a large, diverse military sample. It may be advantageous to assess and therapeutically address TB and PB among at-risk service members. © 2016 Wiley Periodicals, Inc.

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

    Pern, F. J.; Glick, S. H.

    We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVA layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants.« less

  19. Is Mathematical Anxiety Always Bad for Math Learning: The Role of Math Motivation

    PubMed Central

    Wang, Zhe; Lukowski, Sarah L.; Hart, Sara Ann; Lyons, Ian M.; Thompson, Lee A.; Kovas, Yulia; Mazzocco, Michèle M.; Plomin, Robert; Petrill, Stephen A.

    2015-01-01

    The linear relations between math anxiety and math cognition have been frequently studied. However, the relations between anxiety and performance on complex cognitive tasks have been repeatedly demonstrated to follow a curvilinear fashion. Given the lack of attention to the possibility of such complex interplay between emotion and cognition in the math learning literature, the current study aimed to address this gap via exploring the relations between math anxiety, math motivation, and math cognition. The current study consisted of two samples. One sample included 262 pairs of young adolescent twins and the other included 237 adult college students. Participants self-reported their math anxiety and math motivation. Math cognition was assessed using a comprehensive battery of mathematics tasks. In both samples, results showed inverted-U relations between math anxiety and math performance in students with high intrinsic math motivation, and modest negative associations between math anxiety and math performance in students with low intrinsic math motivation. However, this pattern was not observed in tasks assessing student’s nonsymbolic and symbolic number estimation. These findings may help advance our understanding of mathematics learning processes and may provide important insights for treatment programs that target improving mathematics learning experiences and mathematical skills. PMID:26518438

  20. Experimental basis for a Titan probe organic analysis

    NASA Technical Reports Server (NTRS)

    Mckay, C. P.; Scattergood, T. W.; Borucki, W. J.; Kasting, J. F.; Miller, S. L.

    1986-01-01

    The recent Voyager flyby of Titan produced evidence for at least nine organic compounds in that atmosphere that are heavier than methane. Several models of Titan's atmosphere, as well as laboratory simulations, suggest the presence of organics considerably more complex that those observed. To ensure that the in situ measurements are definitive with respect to Titan's atmosphere, experiment concepts, and the related instrumentation, must be carefully developed specifically for such a mission. To this end, the possible composition of the environment to be analyzed must be bracketed and model samples must be provided for instrumentation development studies. Laboratory studies to define the optimum flight experiment and sampling strategy for a Titan entry probe are currently being conducted. Titan mixtures are being subjected to a variety of energy sources including high voltage electron from a DC discharge, high current electric shock, and laser detonation. Gaseous and solid products are produced which are then analyzed. Samples from these experiements are also provided to candidate flight experiments as models for instrument development studies. Preliminary results show that existing theoretical models for chemistry in Titan's atmosphere cannot adequetely explain the presence and abundance of all trace gases observed in these experiments.

  1. [Theoretical and methodological uses of research in Social and Human Sciences in Health].

    PubMed

    Deslandes, Suely Ferreira; Iriart, Jorge Alberto Bernstein

    2012-12-01

    The current article aims to map and critically reflect on the current theoretical and methodological uses of research in the subfield of social and human sciences in health. A convenience sample was used to select three Brazilian public health journals. Based on a reading of 1,128 abstracts published from 2009 to 2010, 266 articles were selected that presented the empirical base of research stemming from social and human sciences in health. The sample was classified thematically as "theoretical/ methodological reference", "study type/ methodological design", "analytical categories", "data production techniques", and "analytical procedures". We analyze the sample's emic categories, drawing on the authors' literal statements. All the classifications and respective variables were tabulated in Excel. Most of the articles were self-described as qualitative and used more than one data production technique. There was a wide variety of theoretical references, in contrast with the almost total predominance of a single type of data analysis (content analysis). In several cases, important gaps were identified in expounding the study methodology and instrumental use of the qualitative research techniques and methods. However, the review did highlight some new objects of study and innovations in theoretical and methodological approaches.

  2. Evaluation of a Gas Chromatograph-Differential Mobility Spectrometer for Potential Water Monitoring on the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2015-01-01

    Environmental monitoring for manned spaceflight has long depended on archival sampling, which was sufficient for short missions. However, the longer mission durations aboard the International Space Station (ISS) have shown that enhanced, real-time monitoring capabilities are necessary in order to protect both the crewmembers and the spacecraft systems. Over the past several years, a number of real-time environmental monitors have been deployed on the ISS. Currently, volatile organic compounds (VOCs) in the station air are monitored by the Air Quality Monitor (AQM), a small, lightweight gas chromatograph-differential mobility spectrometer. For water monitoring, real-time monitors are used for total organic carbon (TOC) and biocide analysis. No information on the actual makeup of the TOC is provided presently, however. An improvement to the current state of environmental monitoring could be realized by modifying a single instrument to analyze both air and water. As the AQM currently provides quantitative, compound-specific information for VOCs in air samples, this instrument provides a logical starting point to evaluate the feasibility of this approach. The major hurdle for this effort lies in the liberation of the target analytes from the water matrix. In this presentation, we will discuss our recent studies, in which an electro-thermal vaporization unit has been interfaced with the AQM to analyze target VOCs at the concentrations at which they are routinely detected in archival water samples from the ISS. We will compare the results of these studies with those obtained from the instrumentation routinely used to analyze archival water samples.

  3. A Trade Study and Metric for Penetration and Sampling Devices for Possible Use on the NASA 2003 and 2005 Mars Sample Return Missions

    NASA Technical Reports Server (NTRS)

    McConnell, Joshua B.

    2000-01-01

    The scientific exploration of Mars will require the collection and return of subterranean samples to Earth for examination. This necessitates the use of some type of device or devices that possesses the ability to effectively penetrate the Martian surface, collect suitable samples and return them to the surface in a manner consistent with imposed scientific constraints. The first opportunity for such a device will occur on the 2003 and 2005 Mars Sample Return missions, being performed by NASA. This paper reviews the work completed on the compilation of a database containing viable penetrating and sampling devices, the performance of a system level trade study comparing selected devices to a set of prescribed parameters and the employment of a metric for the evaluation and ranking of the traded penetration and sampling devices, with respect to possible usage on the 03 and 05 sample return missions. The trade study performed is based on a select set of scientific, engineering, programmatic and socio-political criterion. The use of a metric for the various penetration and sampling devices will act to expedite current and future device selection.

  4. Tumor necrosis factor-α inhibitor treatment and the risk of incident cardiovascular events in patients with early rheumatoid arthritis: a nested case-control study.

    PubMed

    Desai, Rishi J; Rao, Jaya K; Hansen, Richard A; Fang, Gang; Maciejewski, Matthew; Farley, Joel

    2014-11-01

    To compare the risk of cardiovascular (CV) events between use of tumor necrosis factor-α inhibitors (TNFi) and nonbiologic disease-modifying antirheumatic drugs (DMARD) in patients with early rheumatoid arthritis (RA). A nested case-control study was conducted using data from Truven's MarketScan commercial and Medicare claims database for patients with early RA who started treatment with either a TNFi or a nonbiologic DMARD between January 1, 2008, and December 31, 2010. Date of CV event diagnosis for cases was defined as the event date, and 12 age-matched and sex-matched controls were sampled using incidence density sampling. Drug exposure was defined into the following mutually exclusive categories hierarchically: (1) current use of TNFi (with or without nonbiologics), (2) past use of TNFi (with or without nonbiologics), (3) current use of nonbiologics only, and (4) past use of nonbiologics only. Current use was defined as any use in the period 90 days prior to the event date. Conditional logistic regression models were used to derive incidence rate ratios (IRR). From the cohort of patients with early RA, 279 cases of incident CV events and 3348 matched controls were identified. The adjusted risk of CV events was not significantly different between current TNFi users and current nonbiologic users (IRR 0.92, 95% CI 0.59-1.44). However, past users of nonbiologics showed significantly higher risk compared to current nonbiologic users (IRR 1.47, 95% CI 1.04-2.08). No differences in the CV risk were found between current TNFi and current nonbiologic DMARD treatment in patients with early RA.

  5. Activity Patterns in Response to Symptoms in Patients Being Treated for Chronic Fatigue Syndrome: An Experience Sampling Methodology Study

    PubMed Central

    2016-01-01

    Objective: Cognitive–behavioral models of chronic fatigue syndrome (CFS) propose that patients respond to symptoms with 2 predominant activity patterns—activity limitation and all-or-nothing behaviors—both of which may contribute to illness persistence. The current study investigated whether activity patterns occurred at the same time as, or followed on from, patient symptom experience and affect. Method: Twenty-three adults with CFS were recruited from U.K. CFS services. Experience sampling methodology (ESM) was used to assess fluctuations in patient symptom experience, affect, and activity management patterns over 10 assessments per day for a total of 6 days. Assessments were conducted within patients’ daily life and were delivered through an app on touchscreen Android mobile phones. Multilevel model analyses were conducted to examine the role of self-reported patient fatigue, pain, and affect as predictors of change in activity patterns at the same and subsequent assessment. Results: Current experience of fatigue-related symptoms and pain predicted higher patient activity limitation at the current and subsequent assessments whereas subjective wellness predicted higher all-or-nothing behavior at both times. Current pain predicted less all-or-nothing behavior at the subsequent assessment. In contrast to hypotheses, current positive affect was predictive of current activity limitation whereas current negative affect was predictive of current all-or-nothing behavior. Both activity patterns varied at the momentary level. Conclusions: Patient symptom experiences appear to be driving patient activity management patterns in line with the cognitive–behavioral model of CFS. ESM offers a useful method for examining multiple interacting variables within the context of patients’ daily life. PMID:27819461

  6. Breakdown Characteristic Analysis of Paper- Oil Insulation under AC and DC Voltage

    NASA Astrophysics Data System (ADS)

    Anuar, N. F.; Jamail, N. A. M.; Rahman, R. A.; Kamarudin, M. S.

    2017-08-01

    This paper presents the study of breakdown characteristic of Kraft paper insulated with two different types of insulating fluid, which are Palm oil and Coconut oil. Palm oil and Coconut oil are chosen as the alternative fluid to the transformer oil because it has high potential and environmentally-friendly. The Segezha Kraft papers with various thicknesses (65.5 gsm, 75 gsm, 85gsm, 90 gsm) have been used in this research. High Voltage Direct Current (HVDC), High Voltage Alternating Current (HVAC) and carbon track and severity analysis is conducted to observe the sample of aging Kraft paper. These samples have been immersed using Palm oil and Coconut oil up to 90 days to observe the absorption rate. All samples started to reach saturation level at 70 days of immersion. HVDC and HVAC breakdown experiments have been done after the samples had reached the saturation level based on normal condition, immersed in Palm oil and immersed in Coconut oil. All samples immersed in liquid show different breakdown voltage reading compared to normal condition. The analysis of carbon track and severity on surface has been done using Analytical Scanning Electron Microscope (SEM) Analysis. The results of the experiment show that the sample of Kraft paper immersed in Palm oil was better than Coconut oil immersed sample. Therefore the sample condition was the main factor that determines the value of breakdown voltage test. Introduction

  7. A high pressure modulated molecular beam mass spectrometric sampling system

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.; Miller, R. A.

    1977-01-01

    The current state of understanding of free-jet high pressure sampling is critically reviewed and modifications of certain theoretical and empirical considerations are presented. A high pressure, free-jet expansion, modulated molecular beam, mass spectrometric sampling apparatus was constructed and this apparatus is described in detail. Experimental studies have demonstrated that the apparatus can be used to sample high temperature systems at pressures up to one atmosphere. Condensible high temperature gaseous species have been routinely sampled and the mass spectrometric detector has provided direct identification of sampled species. System sensitivity is better than one tenth of a part per million. Experimental results obtained with argon and nitrogen beams are presented and compared to theoretical predictions. These results and the respective comparison are taken to indicate acceptable performance of the sampling apparatus. Results are also given for two groups of experiments related to hot corrosion studies. The formation of gaseous sodium sulfate in doped methane-oxygen flames was characterized and the oxidative vaporization of metals was studied in an atmospheric pressure flowing gas system to which gaseous salt partial pressures were added.

  8. The (non-)replicability of regulatory resource depletion: A field report employing non-invasive brain stimulation

    PubMed Central

    Martijn, Carolien; Alberts, Hugo J. E. M.; Thomson, Alix C.; David, Bastian; Kessler, Daniel

    2017-01-01

    Cognitive effort and self-control are exhausting. Although evidence is ambiguous, behavioural studies have repeatedly suggested that control-demanding tasks seem to deplete a limited cache of self-regulatory resources leading to performance degradations and fatigue. While resource depletion has indirectly been associated with a decline in right prefrontal cortex capacity, its precise neural underpinnings have not yet been revealed. This study consisted of two independent experiments, which set out to investigate the causal role of the right dorsolateral prefrontal cortex (DLPFC) in a classic dual phase depletion paradigm employing non-invasive brain stimulation. In Experiment 1 we demonstrated a general depletion effect, which was significantly eliminated by anodal transcranial Direct Current Stimulation to the right DLPFC. In Experiment 2, however, we failed to replicate the basic psychological depletion effect within a second independent sample. The dissimilar results are discussed in the context of the current ‘replication crisis’ and suggestions for future studies are offered. While our current results do not allow us to firmly argue for or against the existence of resource depletion, we outline why it is crucial to further clarify which specific external and internal circumstances lead to limited replicability of the described effect. We showcase and discuss the current inter-lab replication problem based on two independent samples tested within one research group (intra-lab). PMID:28362843

  9. No rationale for 1 variable per 10 events criterion for binary logistic regression analysis.

    PubMed

    van Smeden, Maarten; de Groot, Joris A H; Moons, Karel G M; Collins, Gary S; Altman, Douglas G; Eijkemans, Marinus J C; Reitsma, Johannes B

    2016-11-24

    Ten events per variable (EPV) is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth's correction, are compared. The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect ('separation'). We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth's correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

  10. Self-objectification and disordered eating: A meta-analysis.

    PubMed

    Schaefer, Lauren M; Thompson, J Kevin

    2018-06-01

    Objectification theory posits that self-objectification increases risk for disordered eating. The current study sought to examine the relationship between self-objectification and disordered eating using meta-analytic techniques. Data from 53 cross-sectional studies (73 effect sizes) revealed a significant moderate positive overall effect (r = .39), which was moderated by gender, ethnicity, sexual orientation, and measurement of self-objectification. Specifically, larger effect sizes were associated with female samples and the Objectified Body Consciousness Scale. Effect sizes were smaller among heterosexual men and African American samples. Age, body mass index, country of origin, measurement of disordered eating, sample type and publication type were not significant moderators. Overall, results from the first meta-analysis to examine the relationship between self-objectification and disordered eating provide support for one of the major tenets of objectification theory and suggest that self-objectification may be a meaningful target in eating disorder interventions, though further work is needed to establish temporal and causal relationships. Findings highlight current gaps in the literature (e.g., limited representation of males, and ethnic and sexual minorities) with implications for guiding future research. © 2018 Wiley Periodicals, Inc.

  11. A review of accuracy assessment for object-based image analysis: From per-pixel to per-polygon approaches

    NASA Astrophysics Data System (ADS)

    Ye, Su; Pontius, Robert Gilmore; Rakshit, Rahul

    2018-07-01

    Object-based image analysis (OBIA) has gained widespread popularity for creating maps from remotely sensed data. Researchers routinely claim that OBIA procedures outperform pixel-based procedures; however, it is not immediately obvious how to evaluate the degree to which an OBIA map compares to reference information in a manner that accounts for the fact that the OBIA map consists of objects that vary in size and shape. Our study reviews 209 journal articles concerning OBIA published between 2003 and 2017. We focus on the three stages of accuracy assessment: (1) sampling design, (2) response design and (3) accuracy analysis. First, we report the literature's overall characteristics concerning OBIA accuracy assessment. Simple random sampling was the most used method among probability sampling strategies, slightly more than stratified sampling. Office interpreted remotely sensed data was the dominant reference source. The literature reported accuracies ranging from 42% to 96%, with an average of 85%. A third of the articles failed to give sufficient information concerning accuracy methodology such as sampling scheme and sample size. We found few studies that focused specifically on the accuracy of the segmentation. Second, we identify a recent increase of OBIA articles in using per-polygon approaches compared to per-pixel approaches for accuracy assessment. We clarify the impacts of the per-pixel versus the per-polygon approaches respectively on sampling, response design and accuracy analysis. Our review defines the technical and methodological needs in the current per-polygon approaches, such as polygon-based sampling, analysis of mixed polygons, matching of mapped with reference polygons and assessment of segmentation accuracy. Our review summarizes and discusses the current issues in object-based accuracy assessment to provide guidance for improved accuracy assessments for OBIA.

  12. Dark Current Characterization of SW HgCdTe IRFPAs Detectors on Si Substrate with Long Time Integration

    NASA Astrophysics Data System (ADS)

    Song, P. Y.; Ye, Z. H.; Huang, A. B.; Chen, H. L.; Hu, X. N.; Ding, R. J.; He, L.

    2016-09-01

    The dark currents of two short wave (SW) HgCdTe infrared focal plane arrays (IRFPA) detectors hybridized with direct injection (DI) readout and capacitance transimpedance amplifier (CTIA) with long time integration were investigated. The cutoff wavelength of the two SW IRFPAs is about 2.6 μm at 84 K. The dark current densities of DI and CTIA samples are approximately 8.0 × 10-12 A/cm2 and 7.2 × 10-10 A/cm2 at 110 K, respectively. The large divergence of the dark current density might arise from the injection efficiency difference of the two readouts. The low injection efficiency of the DI readout, compared with the high injection efficiency of the CTIA readout at low temperature, makes the dark current density of the DI sample much lower than that of the CTIA sample. The experimental value of injection efficiency of the DI sample was evaluated as 1.1% which is consistent with its theoretical value.

  13. Estimating the Velocity and Transport of the East Australian Current using Argo, XBT, and Altimetry

    NASA Astrophysics Data System (ADS)

    Zilberman, N. V.; Roemmich, D. H.; Gille, S. T.

    2016-02-01

    Western Boundary Currents (WBCs) are the strongest ocean currents in the subtropics, and constitute the main pathway through which warm water-masses transit from low to mid-latitudes in the subtropical gyres of the Atlantic, Pacific, and Indian Oceans. Heat advection by WBCs has a significant impact on heat storage in subtropical mode waters formation regions and at high latitudes. The possibility that the magnitude of WBCs might change under greenhouse gas forcing has raised significant concerns. Improving our knowledge of WBC circulation is essential to accurately monitor the oceanic heat budget. Because of the narrowness and strong mesoscale variability of WBCs, estimation of WBC velocity and transport places heavy demands on any potential sampling scheme. One strategy for studying WBCs is to combine complementary data sources. High-resolution bathythermograph (HRX) profiles to 800-m have been collected along transects crossing the East Australian Current (EAC) system at 3-month nominal sampling intervals since 1991. EAC transects, with spatial sampling as fine as 10-15 km, are obtained off Brisbane (27°S) and Sydney (34°S), and crossing the related East Auckland Current north of Auckland. Here, HRX profiles collected since 2004 off Brisbane are merged with Argo float profiles and 1000 m trajectory-based velocities to expand HRX shear estimates to 2000-m and to estimate absolute geostrophic velocity and transport. A method for combining altimetric data with HRX and Argo profiles to mitigate temporal aliasing by the HRX transects and to reduce sampling errors in the HRX/Argo datasets is described. The HRX/Argo/altimetry-based estimate of the time-mean poleward alongshore transport of the EAC off Brisbane is 18.3 Sv, with a width of about 180 km, and of which 3.7 Sv recirculates equatorward on a similar spatial scale farther offshore. Geostrophic transport anomalies in the EAC at 27°S show variability of ± 1.3 Sv at interannual time scale related to ENSO. The present calculation is a case study that will be extended to other subtropical WBCs.

  14. Study of the characteristics current-voltage and capacitance-voltage in nitride GaAs Schottky diode

    NASA Astrophysics Data System (ADS)

    Rabehi, Abdelaziz; Amrani, Mohamed; Benamara, Zineb; Akkal, Boudali; Hatem-Kacha, Arslane; Robert-Goumet, Christine; Monier, Guillaume; Gruzza, Bernard

    2015-10-01

    This article reports the study of Au/GaN/GaAs Schottky diodes, where the thin GaN film is prepared by nitridation of GaAs substrates with thicknesses of 0.7 and 0.8 nm. The resulting GaN sample with thickness 0.8 nm is then treated with an annealing operation (heating to 620 °C) to improve the current transport. The current-voltage (I-V) and capacitance-voltage (C-V) of the Au/GaN/GaAs structures were investigated at room temperature. In fact, the I-V characteristics show that the annealed sample has low series resistance (Rs) and ideality factor (n) (63 Ω, 2.27 respectively) when compared to the values obtained in the untreated sample (1.83 kΩ, 3.31 respectively). The formation of the GaN layer on the gallium arsenide surface is investigated through calculation of the interface state density NSS with and without the presence of series resistance Rs. The value of the interface state density NSS(E) close to the mid-gap was estimated to be in the order of 4.7×1012 cm-2 eV-1 and 1.02× 1013 cm-2 eV-1 with and without the annealing operation, respectively. However, nitridation with the annealing operation at 620 °C improves the electrical properties of the resultant Schottky diode.

  15. Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

    PubMed

    Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

    2014-07-07

    The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

  16. Inclusion in Early Childhood Education: A Zimbabwean Perspective

    ERIC Educational Resources Information Center

    Majoko, Tawanda

    2017-01-01

    The current study examined Early Childhood Education (ECE) teachers' understanding, attitudes and demographic influences regarding inclusion in ECE. Embedded within inclusive pedagogical philosophy, the present descriptive study draws on a sample of 21 ECE teachers purposively selected from ECE settings in Mashonaland West educational province of…

  17. The influence of maternal drinking and drug use on the quality of the home environment of school-aged children.

    PubMed

    Jester, J M; Jacobson, S W; Sokol, R J; Tuttle, B S; Jacobson, J L

    2000-08-01

    Although many studies have examined the development of children of male alcoholics, few studies have considered substance use by the female caregiver. This study evaluated the relationship between substance use by female caregivers and factors that affect the child-rearing environment. A total of 480 inner-city African-American women were recruited during pregnancy for a longitudinal study of the effects of prenatal alcohol use and substance use by caregivers on the development of their children. All women were screened for alcohol consumption at their first prenatal visit to a large urban maternity hospital. Those who averaged seven or more drinks per week (0.5 oz absolute alcohol per day) at the time of conception were invited to participate in the study, as was a 5% random sample of lighter drinkers and abstainers. At the 7.5-year follow-up assessment, the quantity and frequency of alcohol consumption and drug use, as well as several measures of the child-rearing environment, were assessed for 231 of the caregivers. Current alcohol use was uncorrelated with standard demographic factors, such as socioeconomic status, but was related to poorer family functioning, lower quality of parental intellectual stimulation, and higher levels of domestic violence. There were independent effects of illicit drug use on family environment, domestic violence, and caregiver depression. History of drinking during pregnancy, however, was not related to the current child-rearing environment. Poorer parental functioning generally was found only among the caregivers who currently drank both heavily (six or more drinks/occasion) and frequently (three or more days/week). After controlling for lifetime alcohol problems, current drinking still predicted a less cohesive and organized family environment and higher levels of domestic violence. Current heavy, frequent drinking in this relatively homogenous, economically disadvantaged sample was unrelated to demographics and seemed to have an important negative impact on the quality of the child-rearing environment, whereas drinking during pregnancy was unrelated to the current child-rearing environment.

  18. Examination of the Relationships between Fifth Graders' Self-Regulated Learning Strategies, Motivational Beliefs, Attitudes, and Achievement

    ERIC Educational Resources Information Center

    Ocak, Gurbuz; Yamac, Ahmet

    2013-01-01

    The aim of current study was to examine predictor and explanatory relationships between fifth graders' self-regulated learning strategies, motivational beliefs, attitudes towards mathematics, and academic achievement. The study was conducted on a sample of 204 students studying in the primary schools of Afyonkarahisar province. Motivated…

  19. An Evaluation of a Parent Training Program

    ERIC Educational Resources Information Center

    Nguyen, Quynh T.

    2013-01-01

    This study examined the effectiveness of a parent training program whose children are diagnosed with autism. The sample consisted of families who are currently participating in a parent training program. The study examined the stress levels of parents utilizing the Questionnaire on Resources and Stress at the beginning of the study and then again…

  20. The Association between Observed Parental Emotion Socialization and Adolescent Self-Medication

    ERIC Educational Resources Information Center

    Hersh, Matthew A.; Hussong, Andrea M.

    2009-01-01

    The current study examined the moderating influence of observed parental emotion socialization (PES) on self-medication in adolescents. Strengths of the study include the use of a newly developed observational coding system further extending the study of PES to adolescence, the use of an experience sampling method to assess the daily covariation…

  1. Genetic and Environmental Contributions to the Relationship between Violent Victimization and Criminal Behavior

    ERIC Educational Resources Information Center

    Vaske, Jamie; Boisvert, Danielle; Wright, John Paul

    2012-01-01

    Studies have shown that there is a significant association between violent victimization and criminal behavior. One potential explanation for this association is that genetically mediated processes contribute to both violent victimization and criminal behavior. The current study uses data from the twin sample of the National Longitudinal Study of…

  2. Measuring the Influences That Affect Technological Literacy in Rhode Island High Schools

    ERIC Educational Resources Information Center

    Walach, Michael

    2015-01-01

    This study sampled the current state of technological literacy in Rhode Island high schools using a new instrument, the Technological Literacy Assessment, which was developed for this study. Gender inequalities in technological literacy were discovered, and possible causes and solutions are presented. This study suggests possible next steps for…

  3. An Investigation of Relations among Academic Enablers and Reading Outcomes

    ERIC Educational Resources Information Center

    Jenkins, Lyndsay N.; Demaray, Michelle Kilpatrick

    2015-01-01

    The current study examined the link between academic enablers and different types of reading achievement measures. Academic enablers are skills and behaviors that support, or enable, students to perform well academically, such as engagement, interpersonal skills, motivation, and study skills. The sample in this study consisted of 61 third-,…

  4. A Phenomenological Case Study: Teacher Bias Effects on Early Education Assessments

    ERIC Educational Resources Information Center

    Reynolds, Rebecca Jeannine

    2012-01-01

    This qualitative phenomenological case study explored the lived experiences of a purposive sample of 20 current and past early education teachers who have experience in assessing children through observational assessment. The purpose of this study was to determine if bias affects the documentation of observational assessment and the implementation…

  5. Three-Dimensional Grain Shape-Fabric from Unconsolidated Pyroclastic Density Current Deposits: Implications for Extracting Flow Direction and Insights on Rheology

    NASA Astrophysics Data System (ADS)

    Hawkins, T. T.; Brand, B. D.; Sarrochi, D.; Pollock, N.

    2016-12-01

    One of the greatest challenges volcanologists face is the ability to extrapolate information about eruption dynamics and emplacement conditions from deposits. Pyroclastic density current (PDC) deposits are particularly challenging given the wide range of initial current conditions, (e.g., granular, fluidized, concentrated, dilute), and rapid flow transformations due to interaction with evolving topography. Analysis of particle shape-fabric can be used to determine flow direction, and may help to understand the rheological characteristics of the flows. However, extracting shape-fabric information from outcrop (2D) apparent fabric is limited, especially when outcrop exposure is incomplete or lacks context. To better understand and quantify the complex flow dynamics reflected in PDC deposits, we study the complete shape-fabric data in 3D using oriented samples. In the field, the prospective sample is carved from the unconsolidated deposit in blocks, the dimensions of which depend on the average clast size in the sample. The sample is saturated in situ with a water-based sodium silicate solution, then wrapped in plaster-soaked gauze to form a protective cast. The orientation of the sample is recorded on the block faces. The samples dry for five days and are then extracted in intact blocks. In the lab, the sample is vacuum impregnated with sodium silicate and cured in an oven. The fully lithified sample is first cut along the plan view to identify orientations of the long axes of the grains (flow direction), and then cut in the two plains perpendicular to grain elongation. 3D fabric analysis is performed using high resolution images of the cut-faces using computer assisted image analysis software devoted to shape-fabric analysis. Here we present the results of samples taken from the 18 May 1980 PDC deposit facies, including massive, diffuse-stratified and cross-stratified lapilli tuff. We show a relationship between the strength of iso-orientation of the elongated particles and different facies architectures, which is used to interpret rheological conditions of the flow. We chose the 18 May PDC deposits because their well-exposed and well-studied outcrops provide context, which allow us to test the method and extract information useful for interpreting ancient deposits that lack context.

  6. Gratitude uniquely predicts lower depression in chronic illness populations: A longitudinal study of inflammatory bowel disease and arthritis.

    PubMed

    Sirois, Fuschia M; Wood, Alex M

    2017-02-01

    Although gratitude has been identified as a key clinically relevant trait for improving well-being, it is understudied within medical populations. The current study addressed this gap and extended previous and limited cross-sectional research by examining the longitudinal associations of gratitude to depression in 2 chronic illness samples, arthritis and inflammatory bowel disease (IBD). Two chronic illness samples, arthritis (N = 423) and IBD (N = 427), completed online surveys at Time 1 (T1). One hundred sixty-three people with arthritis and 144 people with IBD completed the 6-month follow-up survey (T2). Depression, gratitude, illness cognitions, perceived stress, social support, and disease-related variables were assessed at T1 and T2. At T2, 57.2% of the arthritis sample and 53.4% of the IBD sample met the cut off scores for significant depression. T1 gratitude was negatively associated with depressive symptoms at T1 and T2 in both samples (rs from -.43 to -.50). Regression analyses revealed that T1 gratitude remained a significant and unique predictor of lower T2 depression after controlling for T1 depression, relevant demographic variables, illness cognitions, changes in illness-relevant variables, and another positive psychological construct, thriving, in both samples. As the first investigation of the longitudinal associations of gratitude to psychological well-being in the context of chronic illness, the current study provides important evidence for the relevance of gratitude for health-related clinical populations. Further intervention-based research is warranted to more fully understand the potential benefits of gratitude for adjustment to chronic illness. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Relationship Education for Incarcerated Adults.

    PubMed

    Harcourt, Kate Taylor; Adler-Baeder, Francesca; Rauer, Amy; Pettit, Gregory S; Erath, Stephen

    2017-03-01

    As relationship education (RE) programs become more widely implemented, it is important to measure and document the changes associated with RE for diverse audiences. Also, researchers have been challenged to examine the impact of RE with more disadvantaged groups. While we are seeing an increase in this area, only three studies have examined RE with an incarcerated sample. These previous studies examined only those currently in a relationship and focused primarily on couple functioning. The aim of this study was to expand the existing literature by examining RE with a broader sample of incarcerated adults, regardless of current relationship status, and to expand our understanding of its association with outcomes beyond the couple domain by also including measures of individual and parental functioning. In addition, we examined whether change from pre- to posttest was moderated by individual characteristics. Using a sample of incarcerated adults (N = 122), the study found positive change in three domains of functioning (couple, individual, and parental). Specifically, results indicated change on five of the eight outcome variables examined. Overall, we found both similarities and differences among program participants on changes from pre- to posttest. For the majority of outcomes, the positive change from pre- to posttest emerged regardless of individual characteristics. © 2015 Family Process Institute.

  8. The decay of wood in landfills in contrasting climates in Australia

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

    Ximenes, Fabiano, E-mail: fabiano.ximenes@dpi.nsw.gov.au; Björdal, Charlotte; Cowie, Annette

    Highlights: • We examine decay in wood from landfills in contrasting environments in Australia. • Analysis is based on changes in chemical composition and microscopy. • Climate did not influence levels of decay observed. • Microscopy of retrieved samples revealed most of the decay was aerobic in nature. • Current default factors for wood decay in landfills overestimate methane emissions. - Abstract: Wood products in landfill are commonly assumed to decay within several decades, returning the carbon contained therein to the atmosphere, with about half the carbon released as methane. However, the rate and extent of decay is not wellmore » known, as very few studies have examined the decay of wood products in landfills. This study reports on the findings from landfill excavations conducted in the Australian cities of Sydney and Cairns located in temperate and tropical environments, respectively. The objective of this study was to determine whether burial of the wood in warmer, more tropical conditions in Cairns would result in greater levels of decay than occurs in the temperate environment of Sydney. Wood samples recovered after 16–44 years in landfill were examined through physical, chemical and microscopic analyses, and compared with control samples to determine the carbon loss. There was typically little or no decay in the wood samples analysed from the landfill in Sydney. Although there was significant decay in rainforest wood species excavated from Cairns, decay levels for wood types that were common to both Cairns and Sydney landfills were similar. The current Intergovernmental Panel on Climate Change (IPCC, 2006) default decay factor for organic materials in landfills is 50%. In contrast, the carbon loss determined for Pinus radiata recovered from Sydney and Cairns landfills was 7.9% and 4.4%, respectively, and 0% for Agathis sp. This suggests that climate did not influence decay, and that the more extensive levels of decay observed for some wood samples from Cairns indicates that those wood types were more susceptible to biodegradation. Microscopic analyses revealed that most decay patterns observed in samples analysed from Sydney were consistent with aerobic fungal decay. Only a minor portion of the microbial decay was due to erosion bacteria active in anaerobic/near anaerobic environments. The findings of this study strongly suggest that models that adopt current accepted default factors for the decay of wood in landfills greatly overestimate methane emissions.« less

  9. IN THAILAND.

    PubMed

    Luksamijarulkul, Pipat; Suknongbung, Siranee; Vatanasomboon, Pisit; Sujirarut, Dusit

    2017-03-01

    A large number of migrants have move to cities in Thailand seeking employment. These people may be at increased risk for environmental health problems. We studied the health status, environmental living conditions and microbial indoor air quality (IAQ) among selected groups of migrant workers and their households in Mueang District, Samut Sakhon, central Thailand. We conducted a cross sectional study of 240 migrant workers and their households randomly selected by multistage sampling. The person responsible for hygiene at each studied household was interviewed using a structured questionnaire. Two indoor air samples were taken from each household (480 indoor air samples) to determine bacterial and fungal counts using a Millipore air tester; 240 outdoor air samples were collected for comparison. Ninety-nine point six percent of study subjects were Myanmar, 74.2% were aged 21-40 years, 91.7% had a primary school level education or lower and 53.7% had stayed in Thailand less than 5 years. Eight point three percent had a history of an underlying disease, 20.8% had a recent history of pulmonary tuberculosis in a family member within the previous year. Forty-three point eight percent had a current illness related to IAQ during a previous month. Twenty-one point three were current cigarette smokers, 15.0% were current alcohol consumers, and 5.0% exercises ≥3 times per week. Forty-nine point two percent never opened the windows of their bedrooms or living rooms for ventilation, 45% never cleaned their window screens, and 38.3% never put their pillows or mattresses in the sunlight. The mean(±SD) air bacterial count was 230(±229) CFU/m3 (outdoor air = 128±82 CFU/ m3), and the mean fungal count was 630(±842) CFU/m3 (outdoor air = 138±94 CFU/ m3). When the bacterial and fungal counts were compared with the guidelines of the American Conference of Governmental Industrial Hygienists, the bacterial counts in 6.5% of houses surveyed and the fungal counts in 28.8% of house surveyed were higher than the recommended levels (<500 CFU/m3). Bacterial and fungal counts in the sample households were not significantly correlated with household hygiene practice scores (p>0.05). There was a positive correlation between bacterial counts and fungal counts in household air samples, r=0.28, p<0.001.

  10. Association of Some Vitamins and Minerals with Periodontitis in a Nationally Representative Sample of Korean Young Adults.

    PubMed

    Park, Ji-A; Lee, Jung-Hwa; Lee, Hyo-Jin; Jin, Bo-Hyoung; Bae, Kwang-Hak

    2017-08-01

    The purpose of this study was to investigate whether the intakes of some kinds of vitamins and minerals are associated with periodontitis in a nationally representative sample of young adults. This study comprised 2049 young adults aged 19-39 years who took both periodontal examination and nutrition survey. The vitamin and mineral intakes were calculated from dietary intake data gained by complete one-day 24-h recall interviews, and the intake levels for each nutrient were classified by the Recommended Nutrient Intake (RNI) in Dietary Reference Intakes for Koreans and median values. Periodontitis was assessed using Community Periodontal Index (CPI). Multivariate logistic regression analyses were performed in a whole sample and subgroups with the strata of gender or smoking, following a complex sampling design. In analyses according to RNI, a lower intake of niacin was significantly associated with periodontitis in young adults (odd ratio [OR] 1.47, 95% confidential interval [CI] 1.09-2.00) and in its subgroup of women (OR 1.70; 95% CI 1.10-2.64) and current non-smokers (OR 1.75; 95% CI 1.22-2.51). Whereas, in analyses according to median intake values, there were significant associations of periodontitis with a lower intake of niacin in women (OR 1.58; 95% CI 1.02-2.46) and current non-smokers (OR 1.50; 95% CI 1.01-2.22), with lower intake of vitamin C in women (OR 1.66; 95% CI 1.04-2.64) and in current non-smokers (OR 1.49; 95% CI 1.04-2.14), with lower intake of iron in women (OR 1.85; 95% CI 1.11-3.07), and with lower intake of vitamin A marginally in women (OR 1.56; 95% CI 1.00-2.44). In young adults, periodonitis is significantly associated with the lower intakes of niacin, vitamin C, and iron, especially in women and current non-smokers.

  11. Inception of Snapover and Gas Induced Glow Discharges

    NASA Technical Reports Server (NTRS)

    Galofaro, J. T.; Vayner, B. V.; Degroot, W. A.; Ferguson, D. C.; Thomson, C. D.; Dennison, J. R.; Davies, R. E.

    2000-01-01

    Ground based experiments of the snapover phenomenon were conducted in the large vertical simulation chamber at the Glenn Research Center (GRC) Plasma Interaction Facility (PIF). Two Penning sources provided both argon and xenon plasmas for the experiments. The sources were used to simulate a variety of ionospheric densities pertaining to a spacecraft in a Low Earth Orbital (LEO) environment. Secondary electron emission is believed responsible for dielectric surface charging, and all subsequent snapover phenomena observed. Voltage sweeps of conductor potentials versus collected current were recorded in order to examine the specific charging history of each sample. The average time constant for sample charging was estimated between 25 and 50 seconds for all samples. It appears that current drops off by approximately a factor of 3 over the charging time of the sample. All samples charged in the forward and reverse bias directions, demonstrated hysteresis. Current jumps were only observed in the forward or positive swept voltage direction. There is large dispersion in tile critical snapover potential when repeating sweeps on any one sample. The current ratio for the first snapover region jumps between 2 and 4.6 times, with a standard deviation less than 1.6. Two of the samples showed even larger current ratios. It is believed the second large snapover region is due to sample outgassing. Under certain preset conditions, namely at the higher neutral gas background pressures, a perceptible blue-green glow was observed around the conductor. The glow is believed to be a result of secondary electrons undergoing collisions with an expelled tenuous cloud of gas, that is outgassed from the sample. Spectroscopic measurements of the glow discharge were made in an attempt to identify specific lines contributing to the observed glow.

  12. Relationship between altitude and lithium in groundwater in the United States of America: results of a 1992-2003 study.

    PubMed

    Huber, Rebekah S; Kim, Namkug; Renshaw, Carl E; Renshaw, Perry F; Kondo, Douglas G

    2014-11-01

    Therapeutic dosages of lithium are known to reduce suicide rates, which has led to investigations of confounding environmental risk factors for suicide such as lithium in groundwater. It has been speculated that this might play a role in the potential relationship between suicide and altitude. A recent study in Austria involving geospatial analysis of lithium in groundwater and suicide found lower levels of lithium at higher altitudes. Since there is no reason to suspect this correlation is universal given variation in geology, the current study set out to investigate the relationship between altitude and lithium in groundwater in the United States of America (USA). The study utilised data extracted from the National Water-Quality Assessment programme implemented by the United States Geological Survey that has collected 5,183 samples from 48 study areas in USA for the period of 1992 to 2003. Lithium was the trace-element of interest and 518 samples were used in the current analyses. Due to uneven lithium sampling within the country, only the states (n=15) with the highest number of lithium samples were included. Federal information processing standard codes were used to match data by county with the mean county altitude calculated using altitude data from the Shuttle Radar Topography Mission. The study was controlled for potential confounding factors known to affect levels of lithium in groundwater including aquifer, aquifer type, lithology, water level and the depths of wells. The levels of lithium in groundwater, increased with altitude (R(2) = 0.226, P <0.001) during the study period. These findings differ from the Austrian study and suggest a need for further research accounting also for the impact of geographical variation.

  13. Teachers' Attitudes toward Technology Integration in Schools: A Four-Year Study

    ERIC Educational Resources Information Center

    Liu, Yuliang; Szabo, Zsuzsanna

    2009-01-01

    This trend study was designed to examine a current trend and pattern, as well as a development of teachers' concerns about technology integration in the curriculum. The study was conducted by repeated cross-sectional studies, applying the same research instrument to different samples of subjects at different points, over a period of four years…

  14. The Integration of Children with Disabilities into Regular Schools. A Naturalistic Study. Stage 2 Report.

    ERIC Educational Resources Information Center

    Center, Yola; And Others

    The study used a multiple case study method to investigate the quality of the educational and social experiences of elementary-level and secondary-level children with disabilities currently integrated within the Australian regular school system. This second stage of the study used for its sample 23 children with intellectual disabilities, 18 with…

  15. Aqueous Geochemistry of Lake Tuscaloosa, West-Central Alabama, USA: Drought Response

    NASA Astrophysics Data System (ADS)

    Creech, L., Jr.; Donahoe, R. J.

    2008-12-01

    Lake Tuscaloosa was created in 1969 by the impoundment of the North River near Northport and Tuscaloosa, AL. The reservoir is 25 miles long with a capacity of 123,000 acre-feet, a surface area of 5,885 acres, and an estimated safe yield of 200 M gal/d. It is the receiving water body of a 432 square mile watershed. This project studies the aqueous geochemistry of surface waters using samples representative of different seasonal conditions and land cover. Of the 21 sample locations in this study, three are located on tributaries, four transect the axis of the lake, and the rest are divided among semi-restricted coves representing forested and residential land cover. Sample chemistry is quantified for major, minor, and trace cations, anions, and nutrients, total dissolved nitrogen, DOC, and ALK. The current study presents data collected from the lake and its tributaries during recent severe drought conditions impacting much of the southeastern United States. These data are compared with data from an identical study conducted five years ago during a more normal water year. For each sampling year, four seasonal sampling events were conducted. Both intra- and inter-annual results are reported. Historical USGS data for seven locations sampled since 1986 on a semi-annual basis illustrate a general increase in TDS and nutrients since the lake's creation. Some USGS sample locations coincide with those of the current study. Recently collected data agrees well with recent USGS data for the same locations. It is likely that trends observed in this study are related to anthropogenic effects along the lake shore, as evidenced by the geochemical differences between residential and forested coves. Long-term trends observed in historical data are likely the result of land use in the watershed related to mining, agriculture, and residential development. It is also observed that lower flow conditions are associated with increased solute concentrations, indicating that dilution by rainfall-runoff events is an important factor moderating water quality. These data provide some insight into the impacts prolonged drought may have on Lake Tuscaloosa water quality.

  16. How Individual and Contextual Factors Affects Antisocial and Delinquent Behaviors: A Comparison between Young Offenders, Adolescents at Risk of Social Exclusion, and a Community Sample

    PubMed Central

    Duran-Bonavila, Silvia; Vigil-Colet, Andreu; Cosi, Sandra; Morales-Vives, Fabia

    2017-01-01

    The problems associated with violence during adolescence have been on the rise in recent decades. Many studies have focused only on environmental causes or individual causes of violence, although a combination of both variables would seem to be the best option for prediction. The current study aims to assess the relevance of individual characteristics (personality traits, intelligence, and historical and clinical factors linked to the risk of violence), contextual risk factors and protective factors in explaining antisocial and delinquent behaviors in adolescence by comparing three different samples: a community sample, a sample at risk of social exclusion, and a sample of juvenile offenders. The results show that the samples at risk of social exclusion and the sample of juvenile offenders have a very similar profile in terms of personality traits and intelligence, although they differ from the community sample. However, these two samples do differ in such contextual variables as peer delinquency, poor parental management, community disorganization, or early caregiver disruption. PMID:29104551

  17. How Individual and Contextual Factors Affects Antisocial and Delinquent Behaviors: A Comparison between Young Offenders, Adolescents at Risk of Social Exclusion, and a Community Sample.

    PubMed

    Duran-Bonavila, Silvia; Vigil-Colet, Andreu; Cosi, Sandra; Morales-Vives, Fabia

    2017-01-01

    The problems associated with violence during adolescence have been on the rise in recent decades. Many studies have focused only on environmental causes or individual causes of violence, although a combination of both variables would seem to be the best option for prediction. The current study aims to assess the relevance of individual characteristics (personality traits, intelligence, and historical and clinical factors linked to the risk of violence), contextual risk factors and protective factors in explaining antisocial and delinquent behaviors in adolescence by comparing three different samples: a community sample, a sample at risk of social exclusion, and a sample of juvenile offenders. The results show that the samples at risk of social exclusion and the sample of juvenile offenders have a very similar profile in terms of personality traits and intelligence, although they differ from the community sample. However, these two samples do differ in such contextual variables as peer delinquency, poor parental management, community disorganization, or early caregiver disruption.

  18. A simple novel device for air sampling by electrokinetic capture

    DOE PAGES

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; ...

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

  19. A simple novel device for air sampling by electrokinetic capture

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

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

  20. A simple novel device for air sampling by electrokinetic capture.

    PubMed

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; Frazier, Angel; Hampton-Marcell, Jarrad; Gilbert, Jack A

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.

  1. Chapter A5. Section 6.1.F. Wastewater, Pharmaceutical, and Antibiotic Compounds

    USGS Publications Warehouse

    Lewis, Michael Edward; Zaugg, Steven D.

    2003-01-01

    The USGS differentiates between samples collected for analysis of wastewater compounds and those collected for analysis of pharmaceutical and antibiotic compounds, based on the analytical schedule for the laboratory method. Currently, only the wastewater laboratory method for field-filtered samples (SH1433) is an approved, routine (production) method. (The unfiltered wastewater method LC 8033 also is available but requires a proposal for custom analysis.) At this time, analysis of samples for pharmaceutical and antibiotic compounds is confined to research studies and is available only on a custom basis.

  2. Magnetic properties of CoNiFe alloys electrodeposited under potential and current control conditions

    NASA Astrophysics Data System (ADS)

    Perez, L.; Attenborough, K.; De Boeck, J.; Celis, J. P.; Aroca, C.; Sánchez, P.; López, E.; Sánchez, M. C.

    2002-04-01

    Electrodeposited CoNiFe alloys have been produced under potential and current control conditions. It was found that composition, crystalline structure and magnetic properties are the same irrespective of which plating control is used. Magnetic anisotropy is present in the softest samples. A study of the dependence of magnetic properties and domain structure on the thickness of the films is also reported.

  3. Methods of human body odor sampling: the effect of freezing.

    PubMed

    Lenochova, Pavlina; Roberts, S Craig; Havlicek, Jan

    2009-02-01

    Body odor sampling is an essential tool in human chemical ecology research. However, methodologies of individual studies vary widely in terms of sampling material, length of sampling, and sample processing. Although these differences might have a critical impact on results obtained, almost no studies test validity of current methods. Here, we focused on the effect of freezing samples between collection and use in experiments involving body odor perception. In 2 experiments, we tested whether axillary odors were perceived differently by raters when presented fresh or having been frozen and whether several freeze-thaw cycles affected sample quality. In the first experiment, samples were frozen for 2 weeks, 1 month, or 4 months. We found no differences in ratings of pleasantness, attractiveness, or masculinity between fresh and frozen samples. Similarly, almost no differences between repeatedly thawed and fresh samples were found. We found some variations in intensity; however, this was unrelated to length of storage. The second experiment tested differences between fresh samples and those frozen for 6 months. Again no differences in subjective ratings were observed. These results suggest that freezing has no significant effect on perceived odor hedonicity and that samples can be reliably used after storage for relatively long periods.

  4. On the Link Between Emotionally Driven Impulsivity and Aggression: Evidence From a Validation Study on the Dutch UPPS-P.

    PubMed

    Bousardt, A M C; Noorthoorn, E O; Hoogendoorn, A W; Nijman, H L I; Hummelen, J W

    2018-06-01

    The UPPS-P seems to be a promising instrument for measuring different domains of impulsivity in forensic psychiatric patients. Validation studies of the instrument however, have been conducted only in student groups. In this validation study, three groups completed the Dutch UPPS-P: healthy student ( N = 94) and community ( N = 134) samples and a forensic psychiatric sample ( N = 73). The five-factor structure reported previously could only be substantiated in a confirmatory factor analysis over the combined groups but not in the subsamples. Subgroup sample sizes might be too small to allow such complex analyses. Internal consistency, as assessed by Cronbach's alpha, was high on most subscale and sample combinations. In explaining aggression, especially the initial subscale negative urgency (NU) was related to elevated scores on self-reported aggression in the healthy samples (student and community). The current study is the second study that found a relationship between self-reported NU and aggression highlighting the importance of addressing this behavioural domain in aggression management therapy.

  5. Comet flyby sample return

    NASA Technical Reports Server (NTRS)

    Tsou, P.; Albee, A.

    1985-01-01

    The results of a joint JPL/CSFC feasability study of a low-cost comet sample return flyby mission are presented. It is shown that the mission could be undertaken using current earth orbiter spacecraft technology in conjunction with pathfinder or beacon spacrcraft. Detailed scenarios of missions to the comets Honda-Mrkos-Pajdusakova (HMP), comet Kopff, and comet Giacobini-Zinner (GZ) are given, and some crossectional diagrams of the spacecraft designs are provided.

  6. A Note on Testing Mediated Effects in Structural Equation Models: Reconciling Past and Current Research on the Performance of the Test of Joint Significance

    ERIC Educational Resources Information Center

    Valente, Matthew J.; Gonzalez, Oscar; Miocevic, Milica; MacKinnon, David P.

    2016-01-01

    Methods to assess the significance of mediated effects in education and the social sciences are well studied and fall into two categories: single sample methods and computer-intensive methods. A popular single sample method to detect the significance of the mediated effect is the test of joint significance, and a popular computer-intensive method…

  7. A suite of microsatellite markers optimized for amplification of DNA from Addax (Addax nasomaculatus) blood preserved on FTA cards.

    PubMed

    Heim, Brett C; Ivy, Jamie A; Latch, Emily K

    2012-01-01

    The addax (Addax nasomaculatus) is a critically endangered antelope that is currently maintained in zoos through regional, conservation breeding programs. As for many captive species, incomplete pedigree data currently impedes the ability of addax breeding programs to confidently manage the genetics of captive populations and to select appropriate animals for reintroduction. Molecular markers are often used to improve pedigree resolution, thereby improving the long-term effectiveness of genetic management. When developing a suite of molecular markers, it is important to consider the source of DNA, as the utility of markers may vary across DNA sources. In this study, we optimized a suite of microsatellite markers for use in genotyping captive addax blood samples collected on FTA cards. We amplified 66 microsatellite loci previously described in other Artiodactyls. Sixteen markers amplified a single product in addax, but only 5 of these were found to be polymorphic in a sample of 37 addax sampled from a captive herd at Fossil Rim Wildlife Center in the US. The suite of microsatellite markers developed in this study provides a new tool for the genetic management of captive addax, and demonstrates that FTA cards can be a useful means of sample storage, provided appropriate loci are used in downstream analyses. © 2011 Wiley Periodicals, Inc.

  8. Planetary Protection Requirements for Mars Sample Return Missions: Recommendations from a 2009 NRC Report

    NASA Astrophysics Data System (ADS)

    Race, Margaret; Farmer, Jack

    A 2009 report by the National Research Council (NRC) reviewed a previous study on Mars Sample Return (1997) and provided updated recommendations for future sample return mis-sions based on our current understanding about Mars and its biological potential, as well as advances in technology and analytical capabilities. The committee* made 12 specific recommen-dations that fall into three general categories—one related to current scientific understanding, ten based on changes in the technical and/or policy environment, and one aimed at public com-munication. Substantive changes from the 1997 report relate mainly to protocols and methods, technology and infrastructure, and general oversight. This presentation provides an overview of the 2009 report and its recommendations and analyzes how they may impact mission designs and plans. The full report, Assessment of Planetary Protection Requirements for Mars Sample Return Missions is available online at: http://www.nap.edu/catalog.php?recordi d = 12576 * Study participants: Jack D. Farmer, Arizona State University (chair) James F. Bell III, Cornell University Kathleen C. Benison, Central Michigan University William V. Boynton, University of Arizona Sherry L. Cady, Portland State University F. Grant Ferris, University of Toronto Duncan MacPherson, Jet Propulsion Laboratory Margaret S. Race, SETI Institute Mark H. Thiemens, University of California, San Diego Meenakshi Wadhwa, Arizona State University

  9. Resonant Raman scattering background in XRF spectra of binary samples

    NASA Astrophysics Data System (ADS)

    Sánchez, Héctor Jorge; Leani, Juan José

    2015-02-01

    In x-ray fluorescence analysis, spectra present singular characteristics produced by the different scattering processes. When atoms are irradiated with incident energy lower and close to an absorption edge, scattering peaks appear due to an inelastic process known as resonant Raman scattering. In this work we present theoretical calculations of the resonant Raman scattering contributions to the background of x-ray fluorescence spectra of binary samples of current technological or biological interest. On one hand, a binary alloy of Fe with traces of Mn (Mn: 0.01%, Fe: 99.99%) was studied because of its importance in the stainless steels industries. On the second hand a pure sample of Ti with V traces (Ti: 99%, V: 1%) was analyzed due to the current relevance in medical applications. In order to perform the calculations the Shiraiwa and Fujino's model was used to calculate characteristic intensities and scattering interactions. This model makes certain assumptions and approximations to achieve the calculations, especially in the case of the geometrical conditions and the incident and take-off beams. For the binary sample studied in this work and the considered experimental conditions, the calculations show that the resonant Raman scattering background is significant under the fluorescent peak, affects the symmetry of the peaks and, depending on the concentrations, overcomes the enhancements contributions (secondary fluorescence).

  10. Tobacco promotion and availability in school neighborhoods in India: a cross-sectional study of their impact on adolescent tobacco use.

    PubMed

    Patel, Deepa; Kassim, Saba; Croucher, Ray

    2012-01-01

    Adolescent tobacco use is a major public health problem. However, there is little information about the impact of tobacco advertising and availability near schools on adolescent tobacco use in India. The various tobacco products and brands available in outlets within 100 meters of two high schools in an Indian town were identified. A stratified random sample of 172 participants from these two schools completed a questionnaire on tobacco use and socioeconomic status. Eighteen outlets selling tobacco products were identified. In the two schools the current use of smoked and smokeless tobacco was 9.1% and 17.4% respectively. School location and low socio-economic status of adolescents were associated with tobacco awareness of advertisements (p=0.001) and the receipt of a free sample (p= 0.032). Advertisements on billboards, posters and the receipt of a free tobacco sample were significant factors (p=0.031, p=0.016, p=0.017 respectively) in current tobacco use. In this study a significant proportion of adolescents used tobacco. Tobacco- promotion activities (advertising, the receipt of a free sample), school location and economic status were found to be associated with adolescent tobacco initiation. The local environment should be included in the prevention of adolescent tobacco initiation.

  11. A population on the rise: The origin of deepwater sculpin in Lake Ontario

    USGS Publications Warehouse

    Welsh, Amy B.; Scribner, Kim T.; Stott, Wendylee; Walsh, Maureen

    2017-01-01

    Deepwater sculpin, Myoxocephalus thompsonii, were thought to have been extirpated from Lake Ontario. However, in recent years, abundance has increased and recruitment has been documented. There are two hypotheses concerning the origin of the current Lake Ontario deepwater sculpin population. First, individuals from the upper Great Lakes may have recolonized Lake Ontario. Alternatively, the Lake Ontario population may have not been extirpated, and the remnant population has recovered naturally. To test these hypotheses, eight microsatellite loci were used to analyze samples from the current Lake Ontario population, museum specimens from the historic Lake Ontario population, and current upper Great Lakes populations. The genetic data suggest that historically throughout the Great Lakes, deepwater sculpin exhibited low levels of spatial genetic structure. Approximate Bayesian Computation analyses support the hypothesis that the current Lake Ontario population is more closely related to populations in the upper Great Lakes than to the historic Lake Ontario samples, indicating that the current Lake Ontario population likely resulted from recolonization from the Upper Great Lakes. The current Lake Ontario population has reduced allelic diversity relative to upper Great Lakes populations, indicating a possible founder effect. This study demonstrates the role life history variation can play in recolonization success. The pelagic larval phase of the deepwater sculpin allowed recolonization of Lake Ontario via passive larval drift.

  12. Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

    2015-06-01

    Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors.

  13. Efficient Simulation of Tropical Cyclone Pathways with Stochastic Perturbations

    NASA Astrophysics Data System (ADS)

    Webber, R.; Plotkin, D. A.; Abbot, D. S.; Weare, J.

    2017-12-01

    Global Climate Models (GCMs) are known to statistically underpredict intense tropical cyclones (TCs) because they fail to capture the rapid intensification and high wind speeds characteristic of the most destructive TCs. Stochastic parametrization schemes have the potential to improve the accuracy of GCMs. However, current analysis of these schemes through direct sampling is limited by the computational expense of simulating a rare weather event at fine spatial gridding. The present work introduces a stochastically perturbed parametrization tendency (SPPT) scheme to increase simulated intensity of TCs. We adapt the Weighted Ensemble algorithm to simulate the distribution of TCs at a fraction of the computational effort required in direct sampling. We illustrate the efficiency of the SPPT scheme by comparing simulations at different spatial resolutions and stochastic parameter regimes. Stochastic parametrization and rare event sampling strategies have great potential to improve TC prediction and aid understanding of tropical cyclogenesis. Since rising sea surface temperatures are postulated to increase the intensity of TCs, these strategies can also improve predictions about climate change-related weather patterns. The rare event sampling strategies used in the current work are not only a novel tool for studying TCs, but they may also be applied to sampling any range of extreme weather events.

  14. Rapid Analysis of Carbohydrates in Bioprocess Samples: An Evaluation of the CarboPac SA10 for HPAE-PAD Analysis by Interlaboratory Comparison

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

    Sevcik, R. S.; Hyman, D. A.; Basumallich, L.

    2013-01-01

    A technique for carbohydrate analysis for bioprocess samples has been developed, providing reduced analysis time compared to current practice in the biofuels R&D community. The Thermofisher CarboPac SA10 anion-exchange column enables isocratic separation of monosaccharides, sucrose and cellobiose in approximately 7 minutes. Additionally, use of a low-volume (0.2 mL) injection valve in combination with a high-volume detection cell minimizes the extent of sample dilution required to bring sugar concentrations into the linear range of the pulsed amperometric detector (PAD). Three laboratories, representing academia, industry, and government, participated in an interlaboratory study which analyzed twenty-one opportunistic samples representing biomass pretreatment, enzymaticmore » saccharification, and fermentation samples. The technique's robustness, linearity, and interlaboratory reproducibility were evaluated and showed excellent-to-acceptable characteristics. Additionally, quantitation by the CarboPac SA10/PAD was compared with the current practice method utilizing a HPX-87P/RID. While these two methods showed good agreement a statistical comparison found significant quantitation difference between them, highlighting the difference between selective and universal detection modes.« less

  15. Vapor permeation-stepwise injection simultaneous determination of methanol and ethanol in biodiesel with voltammetric detection.

    PubMed

    Shishov, Andrey; Penkova, Anastasia; Zabrodin, Andrey; Nikolaev, Konstantin; Dmitrenko, Maria; Ermakov, Sergey; Bulatov, Andrey

    2016-02-01

    A novel vapor permeation-stepwise injection (VP-SWI) method for the determination of methanol and ethanol in biodiesel samples is discussed. In the current study, stepwise injection analysis was successfully combined with voltammetric detection and vapor permeation. This method is based on the separation of methanol and ethanol from a sample using a vapor permeation module (VPM) with a selective polymer membrane based on poly(phenylene isophtalamide) (PA) containing high amounts of a residual solvent. After the evaporation into the headspace of the VPM, methanol and ethanol were transported, by gas bubbling, through a PA membrane to a mixing chamber equipped with a voltammetric detector. Ethanol was selectively detected at +0.19 V, and both compounds were detected at +1.20 V. Current subtractions (using a correction factor) were used for the selective determination of methanol. A linear range between 0.05 and 0.5% (m/m) was established for each analyte. The limits of detection were estimated at 0.02% (m/m) for ethanol and methanol. The sample throughput was 5 samples h(-1). The method was successfully applied to the analysis of biodiesel samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Raman spectral analysis for rapid screening of dengue infection

    NASA Astrophysics Data System (ADS)

    Mahmood, T.; Nawaz, H.; Ditta, A.; Majeed, M. I.; Hanif, M. A.; Rashid, N.; Bhatti, H. N.; Nargis, H. F.; Saleem, M.; Bonnier, F.; Byrne, H. J.

    2018-07-01

    Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with lipidic and amino acid/protein content are observed and assigned based on literature and these features can be considered as markers associated with dengue development. Based on the spectroscopic analysis of the current, albeit limited, cohort of samples, Principal Components Analysis (PCA) coupled Factorial Discriminant Analysis, yielded values of 97.95% sensitivity and 95.40% specificity for identification of dengue infection. Furthermore, in a comparison of the normal samples to the patient samples which scored low for only one of the biomarker tests, but high or medium for either or both of the other two, PCA-FDA demonstrated a sensitivity of 97.38% and specificity of 86.18%, thus providing an unambiguous screening technology.

  17. Extracting Hydrologic Understanding from the Unique Space-time Sampling of the Surface Water and Ocean Topography (SWOT) Mission

    NASA Astrophysics Data System (ADS)

    Nickles, C.; Zhao, Y.; Beighley, E.; Durand, M. T.; David, C. H.; Lee, H.

    2017-12-01

    The Surface Water and Ocean Topography (SWOT) satellite mission is jointly developed by NASA, the French space agency (CNES), with participation from the Canadian and UK space agencies to serve both the hydrology and oceanography communities. The SWOT mission will sample global surface water extents and elevations (lakes/reservoirs, rivers, estuaries, oceans, sea and land ice) at a finer spatial resolution than is currently possible enabling hydrologic discovery, model advancements and new applications that are not currently possible or likely even conceivable. Although the mission will provide global cover, analysis and interpolation of the data generated from the irregular space/time sampling represents a significant challenge. In this study, we explore the applicability of the unique space/time sampling for understanding river discharge dynamics throughout the Ohio River Basin. River network topology, SWOT sampling (i.e., orbit and identified SWOT river reaches) and spatial interpolation concepts are used to quantify the fraction of effective sampling of river reaches each day of the three-year mission. Streamflow statistics for SWOT generated river discharge time series are compared to continuous daily river discharge series. Relationships are presented to transform SWOT generated streamflow statistics to equivalent continuous daily discharge time series statistics intended to support hydrologic applications using low-flow and annual flow duration statistics.

  18. Risk analysis of earth return options for the Mars rover/sample return mission

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Four options for return of a Mars surface sample to Earth were studied to estimate the risk of mission failure and the risk of a sample container breach that might result in the release of Martian life forms, should such exist, in the Earth's biosphere. The probabilities calculated refer only to the time period from the last midcourse correction burn to possession of the sample on Earth. Two extreme views characterize this subject. In one view, there is no life on Mars, therefore there is no significant risk and no serious effort is required to deal with back contamination. In the other view, public safety overrides any desire to return Martian samples, and any risk of damaging contamination greater than zero is unacceptable. Zero risk requires great expense to achieve and may prevent the mission as currently envisioned from taking place. The major conclusion is that risk of sample container breach can be reduced to a very low number within the framework of the mission as now envisioned, but significant expense and effort, above that currently planned is needed. There are benefits to the public that warrant some risk. Martian life, if it exists, will be a major discovery. If it does not, there is no risk.

  19. MSeq-CNV: accurate detection of Copy Number Variation from Sequencing of Multiple samples.

    PubMed

    Malekpour, Seyed Amir; Pezeshk, Hamid; Sadeghi, Mehdi

    2018-03-05

    Currently a few tools are capable of detecting genome-wide Copy Number Variations (CNVs) based on sequencing of multiple samples. Although aberrations in mate pair insertion sizes provide additional hints for the CNV detection based on multiple samples, the majority of the current tools rely only on the depth of coverage. Here, we propose a new algorithm (MSeq-CNV) which allows detecting common CNVs across multiple samples. MSeq-CNV applies a mixture density for modeling aberrations in depth of coverage and abnormalities in the mate pair insertion sizes. Each component in this mixture density applies a Binomial distribution for modeling the number of mate pairs with aberration in the insertion size and also a Poisson distribution for emitting the read counts, in each genomic position. MSeq-CNV is applied on simulated data and also on real data of six HapMap individuals with high-coverage sequencing, in 1000 Genomes Project. These individuals include a CEU trio of European ancestry and a YRI trio of Nigerian ethnicity. Ancestry of these individuals is studied by clustering the identified CNVs. MSeq-CNV is also applied for detecting CNVs in two samples with low-coverage sequencing in 1000 Genomes Project and six samples form the Simons Genome Diversity Project.

  20. Transmission Electron Microscopy of Plagioclase-Rich Itokawa Grains: Space Weathering Effects and Solar Flare Track Exposure Ages

    NASA Technical Reports Server (NTRS)

    Keller, Lindsay P.; Berger, Eve L.

    2017-01-01

    Limited samples are available for the study of space weathering effects on airless bodies. The grains returned by the Hayabusa mission to asteroid 25143 Itokawa provide the only samples currently available to study space weathering of ordinary chondrite regolith. We have previously studied olivine-rich Itokawa grains and documented their surface alteration and exposure ages based on the observed density of solar flare particle tracks. Here we focus on the rarer Itokawa plagioclase grains, in order to allow comparisons between Itokawa and lunar soil plagioclase grains for which an extensive data set exists.

  1. Impulsivity Dimensions and Risky Sex Behaviors in an At-Risk Young Adult Sample.

    PubMed

    Curry, Inga; Luk, Jeremy W; Trim, Ryan S; Hopfer, Christian J; Hewitt, John K; Stallings, Michael C; Brown, Sandra A; Wall, Tamara L

    2018-02-01

    Impulsivity is a personality-based risk factor that has been well studied in relation to risky sexual behavior. Recent conceptualizations of impulsivity have proposed multidimensional facets comprised of premeditation, perseverance, sensation seeking, negative urgency, and positive urgency (UPPS-P model). Prior studies have found that these facets are associated with risky sexual behavior in adolescent and college student samples, but no prior studies have evaluated them in clinical samples. The current study examined how impulsivity-related traits related to two different risky sexual behaviors in a clinical sample of at-risk young adults who had both conduct disorder and substance use disorder symptoms as adolescents (n = 529). Lack of premeditation was also tested as a moderator of the relationship between facets of impulsivity and both risky sex outcomes. Results demonstrated that sensation seeking, negative urgency, and positive urgency were correlated with risky sex behaviors. Additionally, multiple regression analyses indicated that sensation seeking was uniquely associated with the number of sexual partners in the past 5 years, whereas positive urgency was uniquely associated with unprotected sex while under the influence. Finally, a significant interaction between lack of premeditation and negative urgency suggests that at-risk young adults with both high negative urgency and lack of premeditation were the likeliest to have the most sexual partners in the past 5 years. This study adds to the current understanding of the relationship between reward- and affect-driven facets of impulsivity and risky sexual behaviors and may lend utility to the development of interventions for at-risk populations.

  2. Study on a pattern classification method of soil quality based on simplified learning sample dataset

    USGS Publications Warehouse

    Zhang, Jiahua; Liu, S.; Hu, Y.; Tian, Y.

    2011-01-01

    Based on the massive soil information in current soil quality grade evaluation, this paper constructed an intelligent classification approach of soil quality grade depending on classical sampling techniques and disordered multiclassification Logistic regression model. As a case study to determine the learning sample capacity under certain confidence level and estimation accuracy, and use c-means algorithm to automatically extract the simplified learning sample dataset from the cultivated soil quality grade evaluation database for the study area, Long chuan county in Guangdong province, a disordered Logistic classifier model was then built and the calculation analysis steps of soil quality grade intelligent classification were given. The result indicated that the soil quality grade can be effectively learned and predicted by the extracted simplified dataset through this method, which changed the traditional method for soil quality grade evaluation. ?? 2011 IEEE.

  3. Fine structure of the amide i band in acetanilide

    NASA Astrophysics Data System (ADS)

    Careri, G.; Gratton, E.; Shyamsunder, E.

    1988-05-01

    Their absorption spectrum of both single crystals and powdered samples of acetanilide (a model system for proteins) has been studied in the amide i region, where a narrow band has been identified as a highly trapped soliton state. The powder-sample spectra have been decomposed using four Lorentzian bands. A strong temperature dependence has been found for the intensity of two of the subbands, which also show a complementary behavior. Polarization studies performed on thin crystals have shown that the subbands have the same polarization. Low-temperature spectra of partially deuterated samples show the presence of the subbands at the same absorption frequencies found using the fitting procedure in the spectra of nondeuterated samples. The soliton model currently proposed to explain the origin of the anomalous amide i component at 1650 cm-1 still holds, but some modification of the model is required to account for the new features revealed by this study.

  4. Belief in reciprocity in a Chinese sample.

    PubMed

    Zhang, Zhen; Zhang, Jianxin

    2012-08-01

    Belief in reciprocity refers to a personally internalized faith in the reciprocity norm: that people will return positive and negative interactions or favors in kind. The current study aims to examine the relationship between belief in reciprocity and altruism among a Chinese sample. The Personal Norm of Reciprocity Scale, Trait Forgiveness Scale, Prosocial Tendency Measure, and Altruism Scale were used to assess extent of belief in reciprocity, forgiveness, and prosocial motivation, respectively, among 204 Chinese undergraduates. The results indicated that belief in reciprocity was a partially negative, but not neutral, reciprocity norm for Chinese people. Specifically, belief in reciprocity was positively related to negative reciprocity, but not significantly related to positive reciprocity. Moreover, belief in reciprocity was negatively related to both prosocial tendency and altruistic motivation. The results also indicated that forgiveness largely mediated the effect of belief in reciprocity on altruism. Finally, the implications and limitations of the current study were discussed.

  5. Smoking and depressive symptoms in a college population.

    PubMed

    Lee Ridner, S; Staten, Ruth R; Danner, Fred W

    2005-08-01

    A number of studies have documented the relationship between smoking and depression in adolescent and adult populations. The purpose of this study was to examine the level of depressive symptoms among college-age smokers and to determine whether or not increases in cigarette use were associated with increases in the number of depressive symptoms. A non-experimental cross-sectional design was used. Of the random sample (N = 895), 28% were current smokers, and more than 26% of the total sample reported high levels of depressive symptoms. Current smokers were more likely to report an increased level of depressive symptoms than nonsmokers were. Correlates of depressive symptoms included grade point average, marijuana use, and increased work hours. When controlling for these variables, the number of days smoked was predictive of depressive symptoms. School nurses have an important role in preventing smoking and treating smokers, as well as in preparing adolescents for the transition to college where many begin smoking.

  6. Measurement of macular pigment optical density in a healthy chinese population sample

    USDA-ARS?s Scientific Manuscript database

    Macular pigment may protect against age-related macular degeneration (AMD) by its capability to absorb blue light and scavenge free radicals. Current information on human macular pigment density has been largely from studies on Caucasians populations. The purpose of this study was to assess macular ...

  7. The Far-UV Wavelength Dependence of the Lunar Phase Curve as Seen by LRO LAMP

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Retherford, K. D.; Greathouse, T. K.; Hendrix, A. R.; Cahill, J. T. S.; Mandt, K. E.; Gladstone, G. R.; Grava, C.; Egan, A. F.; Kaufmann, D. E.; Pryor, W. R.

    2017-10-01

    In this study we discuss the Far-UV wavelength dependence of the lunar phase curves for sample mare and highlands as seen by the LAMP instrument, and we report current derived Hapke parameters at Far-UV wavelengths for the study areas.

  8. An Investigation of Student Psychological Wellbeing: Honors versus Nonhonors Undergraduate Education

    ERIC Educational Resources Information Center

    Plominski, Abigail P.; Burns, Lawrence R.

    2018-01-01

    The purpose of this study was to describe the current state of psychological wellbeing in gifted and nongifted undergraduate student sample populations and identify undergraduate populations experiencing heightened levels of distress within a large Midwestern public university. Study participants included 641 honors and 386 nonhonors undergraduate…

  9. Group Psychotherapy for Women with a History of Incest: The Research Base.

    ERIC Educational Resources Information Center

    Marotta, Sylvia A.; Asner, Kimberly K.

    1999-01-01

    Demonstrates the wide range of adequacy of current studies on group psychotherapy for women with incest histories. Because the studies differed in methodology and reporting, they were categorized and assessed by six criteria: design, sample, inclusion criteria, replicability, analysis, and outcome. Implications for both researchers and…

  10. Business Graduate Skill Sets - Summary Report

    ERIC Educational Resources Information Center

    Jackson, Denise; Chapman, Elaine

    2009-01-01

    The purpose of this study was to evaluate the competencies required by industry in business graduates and the relative importance and current graduate proficiency levels in each skill area. A secondary purpose was to examine and compare the perceived role of contemporary business schools across different samples. The study was conducted during…

  11. Self-Reported Sexual Functioning Concerns among Undergraduate Students

    ERIC Educational Resources Information Center

    Tambling, Rachel B.; Reckert, Ashley

    2014-01-01

    Researchers who have studied sexual functioning concerns do not often focus their research on undergraduate populations, perhaps due to perceptions of universal sexual health among this population. The current study examined prevalence and type of sexual functioning concerns in a sample of 347 male and female undergraduate students. Sexual…

  12. School Psychologist Diagnostic Decision-Making: A Pilot Study

    ERIC Educational Resources Information Center

    Barnard-Brak, Lucy; Stevens, Tara; Robinson, Eric; Holt, Ann

    2013-01-01

    The current study examined the diagnostic decision-making of school psychologists as a function of a student's disability and academic performance with three research questions using a randomly-selected sample of school psychologists from the state of Texas. Results from the first research question indicated that school psychologists significantly…

  13. Correlates of AUDIT Risk Status for Male and Female College Students

    ERIC Educational Resources Information Center

    DeMartini, Kelly S.; Carey, Kate B.

    2009-01-01

    Objective: The current study identified gender-specific correlates of hazardous drinker status as defined by the AUDIT. Participants: A total of 462 college student volunteers completed the study in 2006. The sample was predominantly Caucasian (75%) and female (55%). Methods: Participants completed a survey assessing demographics, alcohol use…

  14. Auditory Backward Masking Deficits in Children with Reading Disabilities

    ERIC Educational Resources Information Center

    Montgomery, Christine R.; Morris, Robin D.; Sevcik, Rose A.; Clarkson, Marsha G.

    2005-01-01

    Studies evaluating temporal auditory processing among individuals with reading and other language deficits have yielded inconsistent findings due to methodological problems (Studdert-Kennedy & Mody, 1995) and sample differences. In the current study, seven auditory masking thresholds were measured in fifty-two 7- to 10-year-old children (26…

  15. A Collection of Papers on Self-Study and Institutional Improvement, 1996.

    ERIC Educational Resources Information Center

    Van Kollenburg, Susan E., Ed.

    This collection presents 68 papers or summaries presented at a 1996 conference on self-study and institutional improvement for institutions of higher education. Papers are grouped in the following 10 chapters (with sample topics in parentheses): (1) "Integrity and Accreditation: Current Issues" (intercollegiate athletics, nontraditional students,…

  16. Geochemical sampling in arid environments by the U.S. Geological Survey

    USGS Publications Warehouse

    Hinkle, Margaret E.

    1988-01-01

    The U.S. Geological Survey (USGS) is responsible for the geochemical evaluations used for mineral resource assessments of large tracts of public lands in the Western United States. Many of these lands are administered by the Bureau of Land Management (BLM) and are studied to determine their suitability or nonsuitability for wilderness designation. Much of the Western United States is arid or semiarid. This report discusses various geochemical sample media that have been used for evaluating areas in arid environments and describes case histories in BLM wilderness study areas in which stream-sediment and heavy-mineral-concentrate sample media were compared. As a result of these case history studies, the nonmagnetic fraction of panned heavy-mineral concentrates was selected as the most effective medium for reconnaissance geochemical sampling for resources other than gold, in arid areas. Nonmagnetic heavy-mineral-concentrate samples provide the primary analytical information currently used in geochemical interpretations of mineral resource potential assessment of BLM lands.

  17. Curating NASA's Astromaterials Collections: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Zeigler, Ryan

    2015-01-01

    Planning for the curation of samples from future sample return missions must begin during the initial planning stages of a mission. Waiting until the samples have been returned to Earth, or even when you begin to physically build the spacecraft is too late. A lack of proper planning could lead to irreversible contamination of the samples, which in turn would compromise the scientific integrity of the mission. For example, even though the Apollo missions first returned samples in 1969, planning for the curation facility began in the early 1960s, and construction of the Lunar Receiving Laboratory was completed in 1967. In addition to designing the receiving facility and laboratory that the samples will be characterized and stored in, there are many aspects of contamination that must be addressed during the planning and building of the spacecraft: planetary protection (both outbound and inbound); cataloging, documenting, and preserving the materials used to build spacecraft (also known as coupons); near real-time monitoring of the environment in which the spacecraft is being built using witness plates for critical aspects of contamination (known as contamination control); and long term monitoring and preservation of the environment in which the spacecraft is being built for most aspects of potential contamination through the use of witness plates (known as contamination knowledge). The OSIRIS REx asteroid sample return mission, currently being built, is dealing with all of these aspects of contamination in order to ensure they return the best preserved sample possible. Coupons and witness plates from OSIRIS REx are currently being studied and stored (for future studies) at the Johnson Space Center. Similarly, planning for the clean room facility at Johnson Space Center to house the OSIRIS-REx samples is well advanced, and construction of the facility should begin in early 2017 (despite a nominal 2023 return date for OSIRIS-REx samples). Similar development is being done, in concert with JAXA, for the return of Hayabusa 2 samples (nominally in 2020). We are also actively developing advanced techniques like cold curation and organically clean curation in anticipation of future sample return missions such as comet nucleus sample return and Mars sample return.

  18. Measures of precision for dissimilarity-based multivariate analysis of ecological communities

    PubMed Central

    Anderson, Marti J; Santana-Garcon, Julia

    2015-01-01

    Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. PMID:25438826

  19. Microscopic and UPLC-UV-MS analyses of authentic and commercial yohimbe (Pausinystalia johimbe) bark samples.

    PubMed

    Raman, Vijayasankar; Avula, Bharathi; Galal, Ahmed M; Wang, Yan-Hong; Khan, Ikhlas A

    2013-01-01

    Yohimbine is the major alkaloid found in the stem bark of yohimbe, Pausinystalia johimbe (Rubiaceae), an evergreen tree native to Africa. The objectives of the current study were to provide a detailed anatomy of yohimbe bark, as well as to determine the quantity of yohimbine in the raw yohimbe products sold online. Twelve commercial raw materials of yohimbe were analyzed by microscopic and ultra performance liquid chromatography-UV-MS methods. The study revealed that three samples were probably adulterated and four other samples contained various levels of impurities. Yohimbine was not detected in one sample, whereas its presence in other samples was found to be in the range 0.1-0.91%. The present work also provides a detailed anatomy of the stem bark of yohimbe, with light and scanning electron microscopy images, for proper identification and authentication.

  20. RESPONDENT-DRIVEN SAMPLING AS MARKOV CHAIN MONTE CARLO

    PubMed Central

    GOEL, SHARAD; SALGANIK, MATTHEW J.

    2013-01-01

    Respondent-driven sampling (RDS) is a recently introduced, and now widely used, technique for estimating disease prevalence in hidden populations. RDS data are collected through a snowball mechanism, in which current sample members recruit future sample members. In this paper we present respondent-driven sampling as Markov chain Monte Carlo (MCMC) importance sampling, and we examine the effects of community structure and the recruitment procedure on the variance of RDS estimates. Past work has assumed that the variance of RDS estimates is primarily affected by segregation between healthy and infected individuals. We examine an illustrative model to show that this is not necessarily the case, and that bottlenecks anywhere in the networks can substantially affect estimates. We also show that variance is inflated by a common design feature in which sample members are encouraged to recruit multiple future sample members. The paper concludes with suggestions for implementing and evaluating respondent-driven sampling studies. PMID:19572381

Top