Establishing the Melbourne injecting drug user cohort study (MIX): rationale, methods, and baseline and twelve-month follow-up results

PubMed Central

2013-01-01

Background Cohort studies provide an excellent opportunity to monitor changes in behaviour and disease transmission over time. In Australia, cohort studies of people who inject drugs (PWID) have generally focused on older, in-treatment injectors, with only limited outcome measure data collected. In this study we specifically sought to recruit a sample of younger, largely out-of-treatment PWID, in order to study the trajectories of their drug use over time. Methods Respondent driven sampling, traditional snowball sampling and street outreach methods were used to recruit heroin and amphetamine injectors from one outer-urban and two inner-urban regions of Melbourne, Australia. Information was collected on participants’ demographic and social characteristics, drug use characteristics, drug market access patterns, health and social functioning, and health service utilisation. Participants are followed-up on an annual basis. Results 688 PWID were recruited into the study. At baseline, the median age of participants was 27.6 years (IQR: 24.4 years – 29.6 years) and two-thirds (67%) were male. Participants reported injecting for a median of 10.2 years (range: 1.5 months – 21.2 years), with 11% having injected for three years or less. Limited education, unemployment and previous incarceration were common. The majority of participants (82%) reported recent heroin injection, and one third reported being enrolled in Opioid Substitution Therapy (OST) at recruitment. At 12 months follow-up 458 participants (71% of eligible participants) were retained in the study. There were few differences in demographic and drug-use characteristics of those lost to follow-up compared with those retained in the study, with attrition significantly associated with recruitment at an inner-urban location, male gender, and providing incomplete contact information at baseline. Conclusions Our efforts to recruit a sample of largely out-of-treatment PWID were limited by drug market characteristics at the time, where fluctuating heroin availability has led to large numbers of PWID accessing low-threshold OST. Nevertheless, this study of Australian injectors will provide valuable data on the natural history of drug use, along with risk and protective factors for adverse health outcomes associated with injecting drug use. Comprehensive follow-up procedures have led to good participant retention and limited attrition bias. PMID:23786848

Description of a computer program to calculate reacting supersonic internal flow fields with shock waves using viscous characteristics: Program manual and sample calculations

NASA Technical Reports Server (NTRS)

Cavalleri, R. J.; Agnone, A. M.

1972-01-01

A computer program for calculating internal supersonic flow fields with chemical reactions and shock waves typical of supersonic combustion chambers with either wall or mid-stream injectors is described. The usefulness and limitations of the program are indicated. The program manual and listing are presented along with a sample calculation.

A general method for bead-enhanced quantitation by flow cytometry

PubMed Central

Montes, Martin; Jaensson, Elin A.; Orozco, Aaron F.; Lewis, Dorothy E.; Corry, David B.

2009-01-01

Flow cytometry provides accurate relative cellular quantitation (percent abundance) of cells from diverse samples, but technical limitations of most flow cytometers preclude accurate absolute quantitation. Several quantitation standards are now commercially available which, when added to samples, permit absolute quantitation of CD4+ T cells. However, these reagents are limited by their cost, technical complexity, requirement for additional software and/or limited applicability. Moreover, few studies have validated the use of such reagents in complex biological samples, especially for quantitation of non-T cells. Here we show that addition to samples of known quantities of polystyrene fluorescence standardization beads permits accurate quantitation of CD4+ T cells from complex cell samples. This procedure, here termed single bead-enhanced cytofluorimetry (SBEC), was equally capable of enumerating eosinophils as well as subcellular fragments of apoptotic cells, moieties with very different optical and fluorescent characteristics. Relative to other proprietary products, SBEC is simple, inexpensive and requires no special software, suggesting that the method is suitable for the routine quantitation of most cells and other particles by flow cytometry. PMID:17067632

Concreteness of idiographic worry and anticipatory processing.

PubMed

McGowan, Sarah Kate; Stevens, Elizabeth S; Behar, Evelyn; Judah, Matt R; Mills, Adam C; Grant, DeMond M

2017-03-01

Worry and anticipatory processing are forms of repetitive negative thinking (RNT) that are associated with maladaptive characteristics and negative consequences. One key maladaptive characteristic of worry is its abstract nature (Goldwin & Behar, 2012; Stöber & Borkovec, 2002). Several investigations have relied on inductions of worry that are social-evaluative in nature, which precludes distinctions between worry and RNT about social-evaluative situations. The present study examined similarities and distinctions between worry and anticipatory processing on potentially important maladaptive characteristics. Participants (N = 279) engaged in idiographic periods of uninstructed mentation, worry, and anticipatory processing and provided thought samples during each minute of each induction. Thought samples were assessed for concreteness, degree of verbal-linguistic activity, and degree of imagery-based activity. Both worry and anticipatory processing were characterized by reduced concreteness, increased abstraction of thought over time, and a predominance of verbal-linguistic activity. However, worry was more abstract, more verbal-linguistic, and less imagery-based relative to anticipatory processing. Finally, worry demonstrated reductions in verbal-linguistic activity over time, whereas anticipatory processing demonstrated reductions in imagery-based activity over time. Worry was limited to non-social topics to distinguish worry from anticipatory processing, and may not represent worry that is social in nature. Generalizability may also be limited by use of an undergraduate sample. Results from the present study provide support for Stöber's theory regarding the reduced concreteness of worry, and suggest that although worry and anticipatory processing share some features, they also contain characteristics unique to each process. Published by Elsevier Ltd.

Tracking radar studies of bird migration

NASA Technical Reports Server (NTRS)

Williams, T. C.; Williams, J. M.; Teal, J. M.; Kanwisher, J. W.

1972-01-01

The application of tracking radar for determining the flight paths of migratory birds is discussed. The effects produced by various meteorological parameters are described. Samples of radar scope presentations obtained during tracking studies are presented. The characteristics of the radars and their limitations are examined.

Spanish Multicenter Normative Studies (NEURONORMA Project): methods and sample characteristics.

PubMed

Peña-Casanova, Jordi; Blesa, Rafael; Aguilar, Miquel; Gramunt-Fombuena, Nina; Gómez-Ansón, Beatriz; Oliva, Rafael; Molinuevo, José Luis; Robles, Alfredo; Barquero, María Sagrario; Antúnez, Carmen; Martínez-Parra, Carlos; Frank-García, Anna; Fernández, Manuel; Alfonso, Verónica; Sol, Josep M

2009-06-01

This paper describes the methods and sample characteristics of a series of Spanish normative studies (The NEURONORMA project). The primary objective of our research was to collect normative and psychometric information on a sample of people aged over 49 years. The normative information was based on a series of selected, but commonly used, neuropsychological tests covering attention, language, visuo-perceptual abilities, constructional tasks, memory, and executive functions. A sample of 356 community dwelling individuals was studied. Demographics, socio-cultural, and medical data were collected. Cognitive normality was validated via informants and a cognitive screening test. Norms were calculated for midpoint age groups. Effects of age, education, and sex were determined. The use of these norms should improve neuropsychological diagnostic accuracy in older Spanish subjects. These data may also be of considerable use for comparisons with other normative studies. Limitations of these normative data are also commented on.

ISO 15859 Propellant and Fluid Specifications: A Review and Comparison with Military and NASA Specifications

NASA Technical Reports Server (NTRS)

Greene, Ben; McClure, Mark B.; Baker, David L.

2006-01-01

This work presents an overview of the International Organization for Standardization (ISO) 15859 International Standard for Space Systems Fluid Characteristics, Sampling and Test Methods Parts 1 through 13 issued in June 2004. These standards establish requirements for fluid characteristics, sampling, and test methods for 13 fluids of concern to the propellant community and propellant characterization laboratories: oxygen, hydrogen, nitrogen, helium, nitrogen tetroxide, monomethylhydrazine, hydrazine, kerosene, argon, water, ammonia, carbon dioxide, and breathing air. A comparison of the fluid characteristics, sampling, and test methods required by the ISO standards to the current military and NASA specifications, which are in use at NASA facilities and elsewhere, is presented. Many ISO standards composition limits and other content agree with those found in the applicable parts of NASA SE-S-0073, NASA SSP 30573, military performance standards and details, and Compressed Gas Association (CGA) commodity specifications. The status of a current project managed at NASA Johnson Space Center White Sands Test Facility (WSTF) to rewrite these documents is discussed.

AC Current Driven Dynamic Vortex State in YBa2Cu3O7-x (Postprint)

DTIC Science & Technology

2012-02-01

coexisting steady states of driven vortex motion with different characteristics: a quasi-static disordered glassy state in the sample interior and a...coexisting, vortex, plastic, dynamic, calculations, disordered , hysteretic, model, films, edges 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...characteris- tics: a quasi-static disordered glassy state in the sample interior and a dynamic state of plastic motion near the edges. Finite- element

Individualized statistical learning from medical image databases: application to identification of brain lesions.

PubMed

Erus, Guray; Zacharaki, Evangelia I; Davatzikos, Christos

2014-04-01

This paper presents a method for capturing statistical variation of normal imaging phenotypes, with emphasis on brain structure. The method aims to estimate the statistical variation of a normative set of images from healthy individuals, and identify abnormalities as deviations from normality. A direct estimation of the statistical variation of the entire volumetric image is challenged by the high-dimensionality of images relative to smaller sample sizes. To overcome this limitation, we iteratively sample a large number of lower dimensional subspaces that capture image characteristics ranging from fine and localized to coarser and more global. Within each subspace, a "target-specific" feature selection strategy is applied to further reduce the dimensionality, by considering only imaging characteristics present in a test subject's images. Marginal probability density functions of selected features are estimated through PCA models, in conjunction with an "estimability" criterion that limits the dimensionality of estimated probability densities according to available sample size and underlying anatomy variation. A test sample is iteratively projected to the subspaces of these marginals as determined by PCA models, and its trajectory delineates potential abnormalities. The method is applied to segmentation of various brain lesion types, and to simulated data on which superiority of the iterative method over straight PCA is demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

Individualized Statistical Learning from Medical Image Databases: Application to Identification of Brain Lesions

PubMed Central

Erus, Guray; Zacharaki, Evangelia I.; Davatzikos, Christos

2014-01-01

This paper presents a method for capturing statistical variation of normal imaging phenotypes, with emphasis on brain structure. The method aims to estimate the statistical variation of a normative set of images from healthy individuals, and identify abnormalities as deviations from normality. A direct estimation of the statistical variation of the entire volumetric image is challenged by the high-dimensionality of images relative to smaller sample sizes. To overcome this limitation, we iteratively sample a large number of lower dimensional subspaces that capture image characteristics ranging from fine and localized to coarser and more global. Within each subspace, a “target-specific” feature selection strategy is applied to further reduce the dimensionality, by considering only imaging characteristics present in a test subject’s images. Marginal probability density functions of selected features are estimated through PCA models, in conjunction with an “estimability” criterion that limits the dimensionality of estimated probability densities according to available sample size and underlying anatomy variation. A test sample is iteratively projected to the subspaces of these marginals as determined by PCA models, and its trajectory delineates potential abnormalities. The method is applied to segmentation of various brain lesion types, and to simulated data on which superiority of the iterative method over straight PCA is demonstrated. PMID:24607564

Modified dough preparation for Alveograph analysis with limited flour sample size

USDA-ARS?s Scientific Manuscript database

Dough rheological characteristics, such as resistance-to-extension and extensibility, obtained by alveograph testing are important traits for determination of wheat and flour quality. A challenging issue that faces wheat breeding programs and some wheat-research projects is the relatively large flou...

Limited-sampling strategies for anti-infective agents: systematic review.

PubMed

Sprague, Denise A; Ensom, Mary H H

2009-09-01

Area under the concentration-time curve (AUC) is a pharmacokinetic parameter that represents overall exposure to a drug. For selected anti-infective agents, pharmacokinetic-pharmacodynamic parameters, such as AUC/MIC (where MIC is the minimal inhibitory concentration), have been correlated with outcome in a few studies. A limited-sampling strategy may be used to estimate pharmacokinetic parameters such as AUC, without the frequent, costly, and inconvenient blood sampling that would be required to directly calculate the AUC. To discuss, by means of a systematic review, the strengths, limitations, and clinical implications of published studies involving a limited-sampling strategy for anti-infective agents and to propose improvements in methodology for future studies. The PubMed and EMBASE databases were searched using the terms "anti-infective agents", "limited sampling", "optimal sampling", "sparse sampling", "AUC monitoring", "abbreviated AUC", "abbreviated sampling", and "Bayesian". The reference lists of retrieved articles were searched manually. Included studies were classified according to modified criteria from the US Preventive Services Task Force. Twenty studies met the inclusion criteria. Six of the studies (involving didanosine, zidovudine, nevirapine, ciprofloxacin, efavirenz, and nelfinavir) were classified as providing level I evidence, 4 studies (involving vancomycin, didanosine, lamivudine, and lopinavir-ritonavir) provided level II-1 evidence, 2 studies (involving saquinavir and ceftazidime) provided level II-2 evidence, and 8 studies (involving ciprofloxacin, nelfinavir, vancomycin, ceftazidime, ganciclovir, pyrazinamide, meropenem, and alpha interferon) provided level III evidence. All of the studies providing level I evidence used prospectively collected data and proper validation procedures with separate, randomly selected index and validation groups. However, most of the included studies did not provide an adequate description of the methods or the characteristics of included patients, which limited their generalizability. Many limited-sampling strategies have been developed for anti-infective agents that do not have a clearly established link between AUC and clinical outcomes in humans. Future studies should first determine if there is an association between AUC monitoring and clinical outcomes. Thereafter, it may be worthwhile to prospectively develop and validate a limited-sampling strategy for the particular anti-infective agent in a similar population.

Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

PubMed

Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

2017-06-14

A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Mineral phases and metals in baghouse dust from secondary ...

EPA Pesticide Factsheets

Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78 BHD samples collected from 13 different SAP facilities across the U.S. were investigated. The XRD semi-quantitative analysis of BHD samples suggests the presence of metallic aluminum, aluminum oxide, aluminum nitride and its oxides, spinel, elpasolite as well as diaspora. BHD also contains halite, sylvite and fluorite, which are used as fluxes in SAP activities. Total aluminum (Al) in the BHD samples averaged 18% by weight. Elevated concentrations of trace metals (>100 µgL-1 As; >1000 µgL-1 Cu, Mn, Se, Pb, Mn and Zn) were also detected in the leachate. The U.S. toxicity characteristic leaching procedure (TCLP) results showed that some samples leached above the toxicity limit for Cd, Pb and Se. Exceeding the TCLP limits in all sample is independent of facilities generating the BHD. From the metal content perspective only, it appears that BHD has a higher potential to exhibit toxicity characteristics than salt cake (the largest waste stream generated by SAP facilities). The objective of this study was to investigate BHD from SAP facilities in the U.S. by determining the mineral phases and the metal (Al, As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Se and Zn) content of the sample

Validation of the LacTek test applied to spiked extracts of tissue samples: determination of performance characteristics.

PubMed

Mitchell, J M; Yee, A J; McNab, W B; Griffiths, M W; McEwen, S A

1999-01-01

LacTek tests are competitive enzyme-linked immunosorbent assays intended for rapid detection of antimicrobial residues in bovine milk. In this study, the LacTek test protocol was modified for use with extracts of bovine tissue to detect beta-lactam, tetracycline, and sulfamethazine residues. Test performance characteristics--precision, accuracy, ruggedness, practicability, and analytical specificity and sensitivity--were investigated. Results suggest that LacTek tests can be easily adapted to detect antimicrobial residues in extracts of lean ground beef. However, positive samples may not contain residues at violative concentrations (i.e., Canadian maximum residue limits), and therefore, additional analysis would be required for final confirmation and quantitation (e.g., chromatography).

Flavor lexicon for sensory descriptive profiling of different rice types.

PubMed

Limpawattana, M; Shewfelt, R L

2010-05-01

Rice flavor is a significant factor in determining quality and consumer acceptability as exemplified by scented rice, which is highly favored and commands a price premium. Sensory descriptive analysis has primarily been performed to assess rice flavor characteristics, but these studies feature only a limited lexicon for characterizing specific flavors or the range of flavor types is limited. This study was undertaken to establish a descriptive lexicon with reference standards for describing the flavor properties of a broad spectrum of rice types and use the developed lexicon to characterize which sensory attributes are most important in rice flavor quality. A rice flavor lexicon consisting of 24 descriptive notes was developed and expanded by 8 trained sensory panelists to characterize the flavor of cooked rice differing in terms of forms, types, and specialty (n = 36). Of these 24 descriptive terms, 19 were aromatic notes and 5 were fundamental tastes and oral feeling factors. Eighteen aromatic terms were significantly present in most rice samples whereas some descriptors exhibited unique characteristics of a specific-rice type. Subsequent multivariate analysis indicated that 18 descriptive terms were required to fully understand the characteristics of rice flavor in greater details. This lexicon covered a wider range of rice samples than in the previous studies and will facilitate targeting the characteristic notes important to rice processors as well as producers.

Probing the galaxy-halo connection in UltraVISTA to z ˜ 2

NASA Astrophysics Data System (ADS)

McCracken, H. J.; Wolk, M.; Colombi, S.; Kilbinger, M.; Ilbert, O.; Peirani, S.; Coupon, J.; Dunlop, J.; Milvang-Jensen, B.; Caputi, K.; Aussel, H.; Béthermin, M.; Le Fèvre, O.

2015-05-01

We use percent-level precision photometric redshifts in the UltraVISTA-DR1 near-infrared survey to investigate the changing relationship between galaxy stellar mass and the dark matter haloes hosting them to z ˜ 2. We achieve this by measuring the clustering properties and abundances of a series of volume-limited galaxy samples selected by stellar mass and star formation activity. We interpret these results in the framework of a phenomenological halo model and numerical simulations. Our measurements span a uniquely large range in stellar mass and redshift and reach below the characteristic stellar mass to z ˜ 2. Our results are: (1) at fixed redshift and scale, clustering amplitude depends monotonically on sample stellar mass threshold; (2) at fixed angular scale, the projected clustering amplitude decreases with redshift but the comoving correlation length remains constant; (3) characteristic halo masses and galaxy bias increase with increasing median stellar mass of the sample; (4) the slope of these relationships is modified in lower mass haloes; (5) concerning the passive galaxy population, characteristic halo masses are consistent with a simply less-abundant version of the full galaxy sample, but at lower redshifts the fraction of satellite galaxies in the passive population is very different from the full galaxy sample; (6) finally, we find that the ratio between the characteristic halo mass and median stellar mass at each redshift bin reaches a peak at log (Mh/M⊙) ˜ 12.2 and the position of this peak remains constant out to z ˜ 2. The behaviour of the full and passively evolving galaxy samples can be understood qualitatively by considering the slow evolution of the characteristic stellar mass in the redshift range probed by our survey.

Computer re-sampling for demographically representative user populations in anthropometry: a case of doorway and clear floor space widths.

PubMed

Paquet, Victor; Joseph, Caroline; D'Souza, Clive

2012-01-01

Anthropometric studies typically require a large number of individuals that are selected in a manner so that demographic characteristics that impact body size and function are proportionally representative of a user population. This sampling approach does not allow for an efficient characterization of the distribution of body sizes and functions of sub-groups within a population and the demographic characteristics of user populations can often change with time, limiting the application of the anthropometric data in design. The objective of this study is to demonstrate how demographically representative user populations can be developed from samples that are not proportionally representative in order to improve the application of anthropometric data in design. An engineering anthropometry problem of door width and clear floor space width is used to illustrate the value of the approach.

Pore Structure and Limit Pressure of Gas Slippage Effect in Tight Sandstone

PubMed Central

You, Lijun; Xue, Kunlin; Kang, Yili; Liao, Yi

2013-01-01

Gas slip effect is an important mechanism that the gas flow is different from liquid flow in porous media. It is generally considered that the lower the permeability in porous media is, the more severe slip effect of gas flow will be. We design and then carry out experiments with the increase of backpressure at the outlet of the core samples based on the definition of gas slip effect and in view of different levels of permeability of tight sandstone reservoir. This study inspects a limit pressure of the gas slip effect in tight sandstones and analyzes the characteristic parameter of capillary pressure curves. The experimental results indicate that gas slip effect can be eliminated when the backpressure reaches a limit pressure. When the backpressure exceeds the limit pressure, the measured gas permeability is a relatively stable value whose range is less than 3% for a given core sample. It is also found that the limit pressure increases with the decreasing in permeability and has close relation with pore structure of the core samples. The results have an important influence on correlation study on gas flow in porous medium, and are beneficial to reduce the workload of laboratory experiment. PMID:24379747

Oversampling of digitized images. [effects on interpolation in signal processing

NASA Technical Reports Server (NTRS)

Fischel, D.

1976-01-01

Oversampling is defined as sampling with a device whose characteristic width is greater than the interval between samples. This paper shows why oversampling should be avoided and discusses the limitations in data processing if circumstances dictate that oversampling cannot be circumvented. Principally, oversampling should not be used to provide interpolating data points. Rather, the time spent oversampling should be used to obtain more signal with less relative error, and the Sampling Theorem should be employed to provide any desired interpolated values. The concepts are applicable to single-element and multielement detectors.

Schizoaffective disorder diagnosed according to different diagnostic criteria--systematic literature search and meta-analysis of key clinical characteristics and heterogeneity.

PubMed

Pagel, Tobias; Franklin, Jeremy; Baethge, Christopher

2014-03-01

Schizoaffective disorder is viewed as a heterogeneous diagnosis among psychotic illnesses. Different diagnostic systems differ in their definition with DSM (-IIIR, -IV, and -V) providing a narrower definition than RDC and ICD-10. It is unclear whether this difference is reflected in patient samples diagnosed according to different diagnostic systems. Exploratory study based on a systematic review of studies of schizoaffective disorder samples diagnosed by either RDC and ICD-10 (group of "broad criteria") or DSM-IIIR and -IV ("narrow criteria"); comparison (by Mann-Whitney-U-tests) of key characteristics, such as age, number of hospitalizations, or scores in psychometric tests, between more broadly and more narrowly defined schizoaffective disorder samples using standard deviations as a measurement of heterogeneity as well as weighted means and percentages. To reduce selection bias only studies including schizoaffective patient samples together with affective disorder and schizophrenia samples were selected. 55 studies were included, 14 employing RDC, 4 ICD-10, 20 DSM-IIIR, and 17 DSM-IV. Thirteen characteristics were compared: patients diagnosed according to broader criteria had fewer previous hospitalizations (2.2 vs. 5.4) and were both less often male (42 vs. 51%) and married (21 vs. 40%). Heterogeneity was similar in both groups but slightly higher in RDC and ICD-10 samples than in DSM-IIIR and -IV-samples: +4% regarding demographic and clinical course data and +13% regarding psychometric tests (pooled SD). Secular trends and different designs may have confounded the results and limit generalizability. Some comparisons were underpowered. Differences in diagnostic criteria are reflected in key characteristics of samples. The association of larger heterogeneity with wider diagnostic criteria supports employing standard deviations as a measurement of heterogeneity. Copyright © 2013 Elsevier B.V. All rights reserved.

Functional difficulties and school limitations of children with epilepsy: findings from the 2009-2010 National Survey of Children with Special Health Care Needs.

PubMed

Pastor, Patricia N; Reuben, Cynthia A; Kobau, Rosemarie; Helmers, Sandra L; Lukacs, Susan

2015-04-01

Epilepsy is a common serious neurologic disorder in children. However, most studies of children's functional difficulties and school limitations have used samples from tertiary care or other clinical settings. To compare functional difficulties and school limitations of a national sample of US children with special health care needs (CSHCN) with and without epilepsy. Data from the 2009-2010 National Survey of CSHCN for 31,897 children aged 6-17 years with and without epilepsy were analyzed for CSHCN in two groups: 1) CSHCN with selected comorbid conditions (intellectual disability, cerebral palsy, autism, or traumatic brain injury) and 2) CSHCN without these conditions. Functional difficulties and school limitations, adjusted for the effect of sociodemographic characteristics, were examined by epilepsy and comorbid conditions. Three percent of CSHCN had epilepsy. Among CSHCN with epilepsy 53% had comorbid conditions. Overall CSHCN with epilepsy, both with and without comorbid conditions, had more functional difficulties than CSHCN without epilepsy. For example, after adjustment for sociodemographic characteristics a higher percentage of children with epilepsy, compared to children without epilepsy, had difficulty with communication (with conditions: 53% vs. 37%, without conditions: 13% vs. 5%). Results for school limitations were similar. After adjustment, a higher percentage of children with epilepsy, compared to children without epilepsy, missed 11 + school days in the past year (with conditions: 36% vs. 18%, without conditions: 21% vs. 15%). CSHCN with epilepsy, compared to CSHCN without epilepsy, were more likely to have functional difficulties and limitations in school attendance regardless of comorbid conditions. Published by Elsevier Inc.

Synoptic scale forecast skill and systematic errors in the MASS 2.0 model. [Mesoscale Atmospheric Simulation System

NASA Technical Reports Server (NTRS)

Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K. F.

1985-01-01

The synoptic scale performance characteristics of MASS 2.0 are determined by comparing filtered 12-24 hr model forecasts to same-case forecasts made by the National Meteorological Center's synoptic-scale Limited-area Fine Mesh model. Characteristics of the two systems are contrasted, and the analysis methodology used to determine statistical skill scores and systematic errors is described. The overall relative performance of the two models in the sample is documented, and important systematic errors uncovered are presented.

Determination of trace elements in automotive fuels by filter furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Anselmi, Anna; Tittarelli, Paolo; Katskov, Dmitri A.

2002-03-01

The determination of Cd, Cr, Cu, Pb and Ni was performed in gasoline and diesel fuel samples by electrothermal atomic absorption spectrometry using the Transverse Heated Filter Atomizer (THFA). Thermal conditions were experimentally defined for the investigated elements. The elements were analyzed without addition of chemical modifiers, using organometallic standards for the calibration. Forty-microliter samples were injected into the THFA. Gasoline samples were analyzed directly, while diesel fuel samples were diluted 1:4 with n-heptane. The following characteristic masses were obtained: 0.8 pg Cd, 6.4 pg Cr, 12 pg Cu, 17 pg Pb and 27 pg Ni. The limits of determination for gasoline samples were 0.13 μg/kg Cd, 0.4 μg/kg Cr, 0.9 μg/kg Cu, 1.5 μg/kg Pb and 2.5 μg/kg Ni. The corresponding limit of determination for diesel fuel samples was approximately four times higher for all elements. The element recovery was performed using the addition of organometallic compounds to gasoline and diesel fuel samples and was between 85 and 105% for all elements investigated.

Characteristics of psychiatric patients for whom financial considerations affect optimal treatment provision.

PubMed

West, Joyce C; Pingitore, David; Zarin, Deborah A

2002-12-01

This study assessed characteristics of psychiatric patients for whom financial considerations affected the provision of "optimal" treatment. Psychiatrists reported that for 33.8 percent of 1,228 patients from a national sample, financial considerations such as managed care limitations, the patient's personal finances, and limitations inherent in the public care system adversely affected the provision of optimal treatment. Patients were more likely to have their treatment adversely affected by financial considerations if they were more severely ill, had more than one behavioral health disorder or a psychosocial problem, or were receiving treatment under managed care arrangements. Patients for whom financial considerations affect the provision of optimal treatment represent a population for whom access to treatment may be particularly important.

Epidemiology and Reporting Characteristics of Systematic Reviews of Biomedical Research: A Cross-Sectional Study.

PubMed

Page, Matthew J; Shamseer, Larissa; Altman, Douglas G; Tetzlaff, Jennifer; Sampson, Margaret; Tricco, Andrea C; Catalá-López, Ferrán; Li, Lun; Reid, Emma K; Sarkis-Onofre, Rafael; Moher, David

2016-05-01

Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using prespecified eligibility criteria. Epidemiological and reporting characteristics of a random sample of 300 SRs were extracted by one reviewer, with a 10% sample extracted in duplicate. We compared characteristics of Cochrane versus non-Cochrane reviews, and the 2014 sample of SRs versus a 2004 sample of SRs. We identified 682 SRs, suggesting that more than 8,000 SRs are being indexed in MEDLINE annually, corresponding to a 3-fold increase over the last decade. The majority of SRs addressed a therapeutic question and were conducted by authors based in China, the UK, or the US; they included a median of 15 studies involving 2,072 participants. Meta-analysis was performed in 63% of SRs, mostly using standard pairwise methods. Study risk of bias/quality assessment was performed in 70% of SRs but was rarely incorporated into the analysis (16%). Few SRs (7%) searched sources of unpublished data, and the risk of publication bias was considered in less than half of SRs. Reporting quality was highly variable; at least a third of SRs did not report use of a SR protocol, eligibility criteria relating to publication status, years of coverage of the search, a full Boolean search logic for at least one database, methods for data extraction, methods for study risk of bias assessment, a primary outcome, an abstract conclusion that incorporated study limitations, or the funding source of the SR. Cochrane SRs, which accounted for 15% of the sample, had more complete reporting than all other types of SRs. Reporting has generally improved since 2004, but remains suboptimal for many characteristics. An increasing number of SRs are being published, and many are poorly conducted and reported. Strategies are needed to help reduce this avoidable waste in research.

Assessment of elder mistreatment in two American Indian samples: psychometric characteristics of the HS-EAST and the Native Elder Life-Financial Exploitation and -Neglect measures.

PubMed

Jervis, Lori L; Fickenscher, Alexandra; Beals, Janette

2014-04-01

Although elder mistreatment among ethnic minorities is increasingly gaining attention, our empirical knowledge of this phenomenon among American Indians remains quite limited, especially with respect to measurement. The Shielding American Indian Elders (SAIE) Project used a collaborative approach to explore culturally informed measurement of elder mistreatment in two American Indian elder samples (a Northern Plains reservation and a South Central metropolitan area). The project sought to investigate the performance characteristics of the commonly used Hwalek-Sengstock Elder Abuse Screening Test (HS-EAST), as well as to examine the psychometric properties of a new measure developed to capture culturally salient aspects of mistreatment in American Indian contexts--the Native Elder Life Scale (NELS). Using methods and samples comparable to those in the literature, the HS-EAST performed adequately in these Native samples. The NELS also shows promise for use with this population and assesses different aspects of elder mistreatment than does the HS-EAST.

Soil properties of crocker formation and its influence on slope instability along the Ranau-Tambunan highway, Sabah

NASA Astrophysics Data System (ADS)

Azlan, Noran Nabilla Nor; Simon, Norbert; Hussin, Azimah; Roslee, Rodeano

2016-11-01

The Crocker formation on the study area consists of an inter-bedded shale and sandstone. The intense deformation and discontinuity on sandstone and shale beds of the arenaceous Crocker Formation makes them easily exposed to weathering and instability. In this study, a total of 15 selected slopes representing highly weathered material of stable and unstable conditions were studied to identify the characteristics of soil material on both conditions and how these characteristics will lead to instability. Physical properties analysis of soil material were conducted on 5 samples from stable slopes and 10 samples from failed slopes collected along the Ranau-Tambunan highway (RTM), Sabah. The analysis shows that the Crocker Formation consists mainly of poorly graded materials of sandy SILT with low plasticity (MLS) and PI value ranges from 1%-14. The failures materials are largely consist of low water content (0.94%-2.03%), higher finer texture material (11%-71%), intermediate liquid limit (21%-44%) and low plastic limit (20%-30%) while stable material consist of low water content (1.25%-1.80%), higher coarser texture material (43%-78%), low liquid limit (25%-28%) and low plastic limit (22%-25%). Specific gravity shows a ranges value of 2.24-2.60 for both slope conditions. The clay content in failed slope samples exhibit a slightly higher percentage of clay indicating a higher plasticity value compared to stable slopes. Statistical analysis was carried out to examine the association between landslide occurrences with soil physical properties in both stable and unstable slopes. The significant of both slope condition properties association to landslide occurrences was determined by mean rank differences. The study reveals that the grain size and plasticity of soil have contributed largely to slope instability in the study area.

The influence of air conditioning, humidity, temperature and other household characteristics on mite allergen concentrations in the northeastern United States.

PubMed

van Strien, R T; Gehring, U; Belanger, K; Triche, E; Gent, J; Bracken, M B; Leaderer, B P

2004-06-01

Information about the influence of housing and occupant characteristics on mite allergen concentrations is crucial to determine which methods could be used to decrease exposure of susceptible subjects. To identify housing and occupant characteristics that are associated with mite allergen concentrations in house dust collected from living rooms and mattresses. We collected dust samples from 750 homes in the northeastern US. The influence of various characteristics on concentrations of mite allergens (Der p 1 and Der f 1) was studied using multiple linear regression analysis. Some characteristics, like absence of air conditioners, the presence of mold or mildew, and a lower temperature were consistently associated with higher concentrations of both mite allergens in dust from all sampling locations. However, none of these factors changed Der p 1 or Der f 1 concentrations by more than a factor of 2. People of white ethnic background had roughly two times higher mite allergen concentrations, while family income, family size, and education level only marginally influenced mite allergen concentrations. Various housing characteristics have some influence on mite allergen concentrations, and could possibly be used to decrease exposure of susceptible subjects. However, only a limited percentage of the variation in mite allergen concentrations was explained by these characteristics.

Computer Programs for Calculating and Plotting the Stability Characteristics of a Balloon Tethered in a Wind

NASA Technical Reports Server (NTRS)

Bennett, R. M.; Bland, S. R.; Redd, L. T.

1973-01-01

Computer programs for calculating the stability characteristics of a balloon tethered in a steady wind are presented. Equilibrium conditions, characteristic roots, and modal ratios are calculated for a range of discrete values of velocity for a fixed tether-line length. Separate programs are used: (1) to calculate longitudinal stability characteristics, (2) to calculate lateral stability characteristics, (3) to plot the characteristic roots versus velocity, (4) to plot the characteristic roots in root-locus form, (5) to plot the longitudinal modes of motion, and (6) to plot the lateral modes for motion. The basic equations, program listings, and the input and output data for sample cases are presented, with a brief discussion of the overall operation and limitations. The programs are based on a linearized, stability-derivative type of analysis, including balloon aerodynamics, apparent mass, buoyancy effects, and static forces which result from the tether line.

[The research protocol III. Study population].

PubMed

Arias-Gómez, Jesús; Villasís-Keever, Miguel Ángel; Miranda-Novales, María Guadalupe

2016-01-01

The study population is defined as a set of cases, determined, limited, and accessible, that will constitute the subjects for the selection of the sample, and must fulfill several characteristics and distinct criteria. The objectives of this manuscript are focused on specifying each one of the elements required to make the selection of the participants of a research project, during the elaboration of the protocol, including the concepts of study population, sample, selection criteria and sampling methods. After delineating the study population, the researcher must specify the criteria that each participant has to comply. The criteria that include the specific characteristics are denominated selection or eligibility criteria. These criteria are inclusion, exclusion and elimination, and will delineate the eligible population. The sampling methods are divided in two large groups: 1) probabilistic or random sampling and 2) non-probabilistic sampling. The difference lies in the employment of statistical methods to select the subjects. In every research, it is necessary to establish at the beginning the specific number of participants to be included to achieve the objectives of the study. This number is the sample size, and can be calculated or estimated with mathematical formulas and statistic software.

Empirically Optimized Flow Cytometric Immunoassay Validates Ambient Analyte Theory

PubMed Central

Parpia, Zaheer A.; Kelso, David M.

2010-01-01

Ekins’ ambient analyte theory predicts, counter intuitively, that an immunoassay’s limit of detection can be improved by reducing the amount of capture antibody. In addition, it also anticipates that results should be insensitive to the volume of sample as well as the amount of capture antibody added. The objective of this study is to empirically validate all of the performance characteristics predicted by Ekins’ theory. Flow cytometric analysis was used to detect binding between a fluorescent ligand and capture microparticles since it can directly measure fractional occupancy, the primary response variable in ambient analyte theory. After experimentally determining ambient analyte conditions, comparisons were carried out between ambient and non-ambient assays in terms of their signal strengths, limits of detection, and their sensitivity to variations in reaction volume and number of particles. The critical number of binding sites required for an assay to be in the ambient analyte region was estimated to be 0.1VKd. As predicted, such assays exhibited superior signal/noise levels and limits of detection; and were not affected by variations in sample volume and number of binding sites. When the signal detected measures fractional occupancy, ambient analyte theory is an excellent guide to developing assays with superior performance characteristics. PMID:20152793

Parental Characteristics and Resiliency in Identification Rates for Special Education

ERIC Educational Resources Information Center

Anderson, Jeffrey A.; Howland, Allison A.; McCoach, D. Betsy

2015-01-01

Even with increased risks, many children demonstrate resiliency and avoid being labeled for special education; however, research on risk and resilience has been problematic because of inadequate statistical models, limitations of available data, and the exclusion of key protective factors. This study used a national sample to examine the influence…

Water Quality, Sediment Characteristics and Benthic Status of the Razim-Sinoie Lagoon System, Romania

NASA Astrophysics Data System (ADS)

Catianis, Irina; Secrieru, Dan; Pojar, Iulian; Grosu, Dumitru; Scrieciu, Albert; Pavel, Ana Bianca; Vasiliu, Dan

2018-03-01

Razim Lake is the biggest of Romania's freshwater lakes and along with other basins as Golovita, Zmeica and Sinoie constitutes a system of great ecological significance, playing also an essential role in the supply of water for irrigation, fishery exploitation, farming, flood prevention, recreational navigation and water tourism. Due to their importance, the environmental conditions in the Razim - Sinoie coastal lakes have attracted an increased public attention in contemporary society. To assess the levels, dissemination and potential sources of contamination in the above-mentioned lagoon system, random sampling was used to collect water and sediment samples from every lake and several analytical techniques were performed to investigate their environmental characteristics. The results obtained from this study indicated that, in water, concentrations of various physico-chemical parameters are, mostly, in agreement with correlated environmental standards. Slight variations and/or occasional exceeding of the maximum admissible limits were generally limited to small areas showing levels that would not warrant special concern. In sediments, the mean concentrations of some specific trace metals were below the levels of potential effect. Benthic samples revealed 31 taxa belonging to 16 zoo-benthal subdivisions. The results of this study showed good ecological status despite local several natural and anthropogenic stressors as fishery exploitation, farming, recreational navigation and water tourism.

Sleep Spindle Characteristics in Children with Neurodevelopmental Disorders and Their Relation to Cognition

PubMed Central

Wise, Merrill S.

2016-01-01

Empirical evidence indicates that sleep spindles facilitate neuroplasticity and “off-line” processing during sleep, which supports learning, memory consolidation, and intellectual performance. Children with neurodevelopmental disorders (NDDs) exhibit characteristics that may increase both the risk for and vulnerability to abnormal spindle generation. Despite the high prevalence of sleep problems and cognitive deficits in children with NDD, only a few studies have examined the putative association between spindle characteristics and cognitive function. This paper reviews the literature regarding sleep spindle characteristics in children with NDD and their relation to cognition in light of what is known in typically developing children and based on the available evidence regarding children with NDD. We integrate available data, identify gaps in understanding, and recommend future research directions. Collectively, studies are limited by small sample sizes, heterogeneous populations with multiple comorbidities, and nonstandardized methods for collecting and analyzing findings. These limitations notwithstanding, the evidence suggests that future studies should examine associations between sleep spindle characteristics and cognitive function in children with and without NDD, and preliminary findings raise the intriguing question of whether enhancement or manipulation of sleep spindles could improve sleep-dependent memory and other aspects of cognitive function in this population. PMID:27478646

A Determination of Air-Sea Gas Exchange and Upper Ocean Biological Production From Five Noble Gases and Tritiugenic Helium-3

DTIC Science & Technology

2007-09-01

limitations due to so-called "bottle effects" produced by confining production to a single bottle, eliminating grazers, trace metal contamination from the...1, b - 2/3) (Levich, 1962 ) or can be determined by modeling studies of characteristic bubble populations (a = 0.7, b = 0.35) (Keeling, 1993). In this...artifacts associated with the early sampling method. In addition, some of the samples with large supersaturations may have been contaminated with

Electrical conduction in 100 keV Kr+ ion implanted poly (ethylene terephthalate)

NASA Astrophysics Data System (ADS)

Goyal, P. K.; Kumar, V.; Gupta, Renu; Mahendia, S.; Anita, Kumar, S.

2012-06-01

Polyethylene terephthalate (PET) samples have been implanted to 100 keV Kr+ ions at the fluences 1×1015-- 1×1016 cm-2. From I-V characteristics, the conduction mechanism was found to be shifted from ohmic to space charge limited conduction (SCLC) after implantation. The surface conductivity of these implanted samples was found to increase with increasing implantation dose. The structural alterations in the Raman spectra of implanted PET samples indicate that such an increase in the conductivity may be attributed to the formation of conjugated double bonded carbonaceous structure in the implanted layer of PET.

Provenance study through analysis of microstructural characteristics using an optical microscope and scanning electron microscopy for Goryeo celadon excavated from the seabed.

PubMed

Min-su, Han

2013-08-01

This paper aims at identifying the provenance of Goryeo celadons by understanding its microstructural characteristics, such as particles, blisters, forms and amount of pores, and the presence of crystal formation, bodies, and glazes and its boundary, using an optical microscope and scanning electron microscopy (SEM). The analysis of the reproduced samples shows that the glazed layer of the sherd fired at higher temperatures has lower viscosity and therefore it encourages the blisters to be combined together and the layer to become more transparent. In addition, the result showed that the vitrification and melting process of clay minerals such as feldspars and quartzs on the bodies was accelerated for those samples. To factor such characteristics of the microstructure and apply it to the sherds, the samples could be divided into six categories based on status, such as small particles with many small pores or mainly large and small circular pores in the bodies, only a limited number of varied sized blisters in the glazes, and a few blisters and needle-shaped crystals on the boundary surface. In conclusion, the analysis of the microstructural characteristics using an optical microscope and SEM have proven to be useful as a categorizing reference factor in a provenance study on Goryeo celadons.

Derivatization coupled to headspace programmed-temperature vaporizer gas chromatography with mass spectrometry for the determination of amino acids: Application to urine samples.

PubMed

González Paredes, Rosa María; García Pinto, Carmelo; Pérez Pavón, José Luis; Moreno Cordero, Bernardo

2016-09-01

A new method based on headspace programmed-temperature vaporizer gas chromatography with mass spectrometry has been developed and validated for the determination of amino acids (alanine, sarcosine, ethylglycine, valine, leucine, and proline) in human urine samples. Derivatization with ethyl chloroformate was employed successfully to determine the amino acids. The derivatization reaction conditions as well as the variables of the headspace sampling were optimized. The existence of a matrix effect was checked and the analytical characteristics of the method were determined. The limits of detection were 0.15-2.89 mg/L, and the limits of quantification were 0.46-8.67 mg/L. The instrumental repeatability was 1.6-11.5%. The quantification of the amino acids in six urine samples from healthy subjects was performed with the method developed with the one-point standard additions protocol, with norleucine as the internal standard. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Natural occurrence of alternariol and alternariol monomethyl ether in soya beans.

PubMed

Oviedo, M S; Barros, G G; Chulze, S N; Ramirez, M L

2012-08-01

The natural occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in soya beans harvested in Argentina was evaluated. Both toxins were simultaneously detected by using HPLC analysis coupled with a solid phase extraction column clean-up. Characteristics of this in-house method such as accuracy, precision and detection and quantification limits were defined by means of recovery test with spiked soya bean samples. Out of 50 soya bean samples, 60% showed contamination with the mycotoxins analyzed; among them, 16% were only contaminated with AOH and 14% just with AME. Fifteen of the positive samples showed co-occurrence of both mycotoxins analyzed. AOH was detected in concentrations ranging from 25 to 211 ng/g, whereas AME was found in concentrations ranging from 62 to 1,153 ng/g. Although a limited number of samples were evaluated, this is the first report on the natural occurrence of Alternaria toxins in soya beans and is relevant from the point of view of animal public health.

Neighborhood built environment and cognition in non-demented older adults: The Multi-Ethnic Study of Atherosclerosis.

PubMed

Besser, Lilah M; Rodriguez, Daniel A; McDonald, Noreen; Kukull, Walter A; Fitzpatrick, Annette L; Rapp, Stephen R; Seeman, Teresa

2018-03-01

Preliminary studies suggest that neighborhood social and built environment (BE) characteristics may affect cognition in older adults. Older adults are particularly vulnerable to the neighborhood environment due to a decreasing range of routine travel with increasing age. We examined if multiple neighborhood BE characteristics are cross-sectionally associated with cognition in a diverse sample of older adults, and if the BE-cognition associations vary by individual-level demographics. The sample included 4539 participants from the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine the associations between five BE measures and four cognitive measures, and effect modification by individual-level education and race/ethnicity. In the overall sample, increasing social destination density, walking destination density, and intersection density were associated with worse overall cognition, whereas increasing proportion of land dedicated to retail was associated with better processing speed. Effect modification results suggest that the association between urban density and worse cognition may be limited to or strongest in those of non-white race/ethnicity. Although an increase in neighborhood retail destinations was associated with better cognition in the overall sample, these results suggest that certain BE characteristics in dense urban environments may have a disproportionately negative association with cognition in vulnerable populations. However, our findings must be replicated in longitudinal studies and other regional samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nondestructive Determination of Cu Residue in Orange Peel by Laser Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Hu, Huiqin; Huang, Lin; Liu, Muhua; Chen, Tianbing; Yang, Ping; Yao, Mingyin

2015-08-01

Laser induced breakdown spectroscopy (LIBS) is an emerging tool with rapid, nondestructive, green characteristics in qualitative or quantitative analyses of composition in materials. But LIBS has its shortcomings in detect limit and sensitivity. In this work, heavy metal Cu in Gannan Navel Orange, which is one of famous fruits from Jiangxi of China, was analyzed. In view of LIBS's limit, it is difficult to determinate heavy metals in natural fruits. In this work, nine orange samples were pretreated in 50-500 μg/mL Cu solution, respectively. Another one orange sample was chosen as a control group without any pollution treatment. Previous researchers observed that the content of heavy metals is much higher in peel than in pulp. So, the content in pulp can be reflected by detecting peel. The real concentrations of Cu in peels were acquired by atomic absorption spectrophotometer (AAS). A calibration model of Cu I 324.7 and Cu I 327.4 was constructed between LIBS intensity and AAS concentration by six samples. The correlation coefficient of the two models is also 0.95. All of the samples were used to verify the accuracy of the model. The results show that the relative error (RE) between predicted and real concentration is less than 6.5%, and Cu I 324.7 line has smaller RE than Cu I 327.4. The analysis demonstrated that different characteristic lines decided different accuracy. The results prove the feasibility of detecting heavy metals in fruits by LIBS. But the results are limited in treated samples. The next work will focus on direct analysis of heavy metals in natural fruits without any pretreatment. This work is helpful to explore the distribution of heavy metals between pulp and peel. supported by National Natural Science Foundation of China (No. 31460419) and Major Project of Science and Technology of Jiangxi, China (No. 20143ACB21013)

Influence of riffle characteristics, surficial geology, and natural barriers on the distribution of the channel darter, Percina copelandi, in the Lake Ontario basin

USGS Publications Warehouse

Reid, S.M.; Carl, L.M.; Lean, J.

2005-01-01

The channel darter, Percina copelandi, is a small benthic fish with a wide but disjunct distribution across central North America. The development of conservation and recovery strategies for Canadian populations is limited by a lack of knowledge regarding ecology, population size and other factors that affect its distribution and abundance. We sampled five rivers in the Lake Ontario basin to test whether the distribution of P. copelandi reflected riffle habitat characteristics or landscape-scale factors such as surficial geology and natural barriers (waterfalls). At most sites yielding P. copelandi, riffles flowed into deep sand bottomed run or pool habitats. Despite a lack of association with local surficial geology or riffle habitat characteristics, both the upstream limits of P. copelandi occurrence and distribution of suitable habitats reflected the distribution of waterfalls, chutes and bedrock outcroppings. In contrast to P. copelandi, distributions of Etheostoma flabellare, P. caprodes and Rhinichthys cataractae reflected among site differences in riffle habitat. ?? Springer 2005.

Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States

USGS Publications Warehouse

Knight, Rodney R.; Murphy, Jennifer C.; Wolfe, William J.; Saylor, Charles F.; Wales, Amy K.

2014-01-01

Ecological limit functions relating streamflow and aquatic ecosystems remain elusive despite decades of research. We investigated functional relationships between species richness and changes in streamflow characteristics at 662 fish sampling sites in the Tennessee River basin. Our approach included the following: (1) a brief summary of relevant literature on functional relations between fish and streamflow, (2) the development of ecological limit functions that describe the strongest discernible relationships between fish species richness and streamflow characteristics, (3) the evaluation of proposed definitions of hydrologic reference conditions, and (4) an investigation of the internal structures of wedge-shaped distributions underlying ecological limit functions.Twenty-one ecological limit functions were developed across three ecoregions that relate the species richness of 11 fish groups and departures from hydrologic reference conditions using multivariate and quantile regression methods. Each negatively sloped function is described using up to four streamflow characteristics expressed in terms of cumulative departure from hydrologic reference conditions. Negative slopes indicate increased departure results in decreased species richness.Sites with the highest measured fish species richness generally had near-reference hydrologic conditions for a given ecoregion. Hydrology did not generally differ between sites with the highest and lowest fish species richness, indicating that other environmental factors likely limit species richness at sites with reference hydrology.Use of ecological limit functions to make decisions regarding proposed hydrologic regime changes, although commonly presented as a management tool, is not as straightforward or informative as often assumed. We contend that statistical evaluation of the internal wedge structure below limit functions may provide a probabilistic understanding of how aquatic ecology is influenced by altered hydrology and may serve as the basis for evaluating the potential effect of proposed hydrologic changes.

Heavily Sn-doped GaAs with abrupt doping profiles grown by migration-enhanced epitaxy at low temperatures

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

Chavanapranee, Tosaporn; Horikoshi, Yoshiji

The characteristics of heavily Sn-doped GaAs samples grown at 300 deg. C by a migration-enhanced epitaxy (MEE) technique are investigated in comparison with those of the samples grown by a conventional molecular-beam epitaxy (MBE) at 580 deg. C. While no discernible difference is observed in the low doping regime, the difference in doping characteristics between the MBE- and MEE-grown samples becomes apparent when the doping concentration exceeds 1x10{sup 19} cm{sup -3}. Sn atoms as high as 4x10{sup 21} cm{sup -3} can be incorporated into MEE-grown GaAs films, unlike the MBE-grown samples that have a maximum doping level limited around 1x10{supmore » 19} cm{sup -3}. Due to an effective suppression of Sn segregation in the MEE growth case, high quality GaAs films with abrupt high-concentration Sn-doping profiles are achieved with the doping concentrations of up to 2x10{sup 21} cm{sup -3}. It has been shown that even though a high concentration of Sn atoms is incorporated into the GaAs film, the electron concentration saturates at 6x10{sup 19} cm{sup -3} and then gradually decreases with Sn concentration. The uniform doping limitation, as well as the electron concentration saturation, is discussed by means of Hall-effect measurement, x-ray diffraction, and Raman scattering spectroscopy.« less

Identifying Discriminating Variables between Teachers Who Fully Integrate Computers and Teachers with Limited Integration

ERIC Educational Resources Information Center

Mueller, Julie; Wood, Eileen; Willoughby, Teena; Ross, Craig; Specht, Jacqueline

2008-01-01

Given the prevalence of computers in education today, it is critical to understand teachers' perspectives regarding computer integration in their classrooms. The current study surveyed a random sample of a heterogeneous group of 185 elementary and 204 secondary teachers in order to provide a comprehensive summary of teacher characteristics and…

A Longitudinal Examination of Risky Sexual Behaviors among Canadian and Italian Adolescents: Considering Individual, Parental, and Friend Characteristics

ERIC Educational Resources Information Center

Boislard P., Marie-Aude; Poulin, Francois; Kiesner, Jeff; Dishion, Thomas J.

2009-01-01

In this study, two longitudinal models of early adolescent risky sexual behaviors (RSB) were compared using a pooled sample of 267 Canadian and Italian adolescents (55% females; 53% Canadians) assessed yearly from grade 8 to 10. We focused on parenting practices (monitoring, control, limit setting), adolescent problem behaviors (antisocial…

A stopped-flow calorimeter for biochemical applications.

PubMed Central

Howarth, J V; Millar, N C; Gutfreund, H

1987-01-01

A rapid-response stopped-flow calorimeter for small samples of reagents is described. The construction, performance characteristics and operational limitations are described, along with an example of its ability to resolve the kinetics of an enzyme-catalysed hydrolysis. It is thought likely that the method would find useful application in a variety of chemical and biochemical investigations. PMID:3435478

Methodological Challenges in Collecting Social and Behavioural Data Regarding the HIV Epidemic among Gay and Other Men Who Have Sex with Men in Australia

PubMed Central

Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Background Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Methods Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Results Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Conclusion Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM. PMID:25409440

Methodological challenges in collecting social and behavioural data regarding the HIV epidemic among gay and other men who have sex with men in Australia.

PubMed

Zablotska, Iryna B; Frankland, Andrew; Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM.

Employer knowledge of federal requirements for recording work-related injuries and illnesses: Implications for occupational injury surveillance data.

PubMed

Wuellner, Sara; Phipps, Polly

2018-05-01

Accuracy of the Bureau of Labor Statistics Survey of Occupational Injuries and Illnesses (SOII) data is dependent on employer compliance with workplace injury and illness recordkeeping requirements. Characterization of employer recordkeeping can inform efforts to improve the data. We interviewed representative samples of SOII respondents from four states to identify common recordkeeping errors and to assess employer characteristics associated with limited knowledge of the recordkeeping requirements and non compliant practices. Less than half of the establishments required to maintain OSHA injury and illness records reported doing so. Few establishments knew to omit cases limited to diagnostic services (22%) and to count unscheduled weekend days as missed work (27%). No single state or establishment characteristic was consistently associated with better or worse record-keeping. Many employers possess a limited understanding of workplace injury recordkeeping requirements, potentially leading them to over-report minor incidents, and under-report missed work cases. © 2018 Wiley Periodicals, Inc.

PREPARATION AND ELECTRICAL PROPERTIES OF BiFeO3/La0.7Sr0.3MnO3 MULTILAYERS

NASA Astrophysics Data System (ADS)

Zhu, Huiwen; Wang, Shunli; Li, Xiaoyun

2013-07-01

(La0.7Sr0.3MnO3 12 nm/BiFeO3 12 nm)10 was grown on SrTiO3 (001) substrate using rf magnetron sputtering. The structure analysis indicated that BiFeO3/La0.7Sr0.3MnO3 multilayers were highly (001)-oriented. Compared with bottom La0.7Sr0.3MnO3 electrode, the top La0.7Sr0.3MnO3 electrode displayed a rougher surface. The electric transport characteristics of the sample were investigated mainly at low temperature, and it was found that the sample exhibited resistance-temperature curves similar to those of La0.7Sr0.3MnO3 with the exception of an upturn at lower temperature region. Furthermore, a nonlinear I-V curve, which is characteristic of a tunneling conduction mechanism, was observed at 50 K. At higher temperature, the I-V curves were found to be diode-like. When the temperature was further increased to 300 K, the sample showed a space charge limited conduction (SCLC) characteristic.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses.

PubMed

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-09-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.

Use of a single-bowl continuous-flow centrifuge for dewatering suspended sediments: effect on sediment physical and chemical characteristics

USGS Publications Warehouse

Rees, T.F.; Leenheer, J.A.; Ranville, J.F.

1991-01-01

Sediment-recovery efficiency of 86-91% is comparable to that of other types of CFC units. The recovery efficiency is limited by the particle-size distribution of the feed water and by the limiting particle diameter that is retained in the centrifuge bowl. Contamination by trace metals and organics is minimized by coating all surfaces that come in contact with the sample with either FEP or PFA Teflon and using a removable FEP Teflon liner in the centrifuge bowl. -from Authors

Epidemiology and Reporting Characteristics of Systematic Reviews of Biomedical Research: A Cross-Sectional Study

PubMed Central

Page, Matthew J.; Shamseer, Larissa; Altman, Douglas G.; Tetzlaff, Jennifer; Tricco, Andrea C.; Catalá-López, Ferrán; Li, Lun; Reid, Emma K.; Sarkis-Onofre, Rafael; Moher, David

2016-01-01

Background Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. Methods and Findings We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using prespecified eligibility criteria. Epidemiological and reporting characteristics of a random sample of 300 SRs were extracted by one reviewer, with a 10% sample extracted in duplicate. We compared characteristics of Cochrane versus non-Cochrane reviews, and the 2014 sample of SRs versus a 2004 sample of SRs. We identified 682 SRs, suggesting that more than 8,000 SRs are being indexed in MEDLINE annually, corresponding to a 3-fold increase over the last decade. The majority of SRs addressed a therapeutic question and were conducted by authors based in China, the UK, or the US; they included a median of 15 studies involving 2,072 participants. Meta-analysis was performed in 63% of SRs, mostly using standard pairwise methods. Study risk of bias/quality assessment was performed in 70% of SRs but was rarely incorporated into the analysis (16%). Few SRs (7%) searched sources of unpublished data, and the risk of publication bias was considered in less than half of SRs. Reporting quality was highly variable; at least a third of SRs did not report use of a SR protocol, eligibility criteria relating to publication status, years of coverage of the search, a full Boolean search logic for at least one database, methods for data extraction, methods for study risk of bias assessment, a primary outcome, an abstract conclusion that incorporated study limitations, or the funding source of the SR. Cochrane SRs, which accounted for 15% of the sample, had more complete reporting than all other types of SRs. Reporting has generally improved since 2004, but remains suboptimal for many characteristics. Conclusions An increasing number of SRs are being published, and many are poorly conducted and reported. Strategies are needed to help reduce this avoidable waste in research. PMID:27218655

Physicochemical characteristics and pollen spectra of organic and non-organic honey samples of Apis mellifera L.

PubMed

Sereia, Maria Josiane; Alves, Eloi M; Toledo, Vagner A A; Marchini, Luis C; Serine, Elizabete S; Faquinello, Patricia; Almeida, Daniela de; Moreti, Augusta C C C

2011-09-01

The aim of this research was to analyze and compare 17 honey samples, 11 organic and six non-organic Apis mellifera honey. The samples were analyzed concerning moisture, hydroxymethylfurfural, diastase index, water activity, color, total sugar, reducing sugar, sucrose, ash, viscosity, electrical conductivity, pH, acidity, and formol index. With the exception of acidity, reducing sugar and diastase index, the averages of other parameters were different between the two groups. All samples of organic honey presented moisture values between 23.50 and 24.40%. Among the nonorganic honey samples, two presented apparent sucrose amount upper the maximum limit established by the Brazilian Legislation. According to the quantitative analysis of pollen sediments in the honey samples and frequency of pollen types in 17 honey samples, 41.20% were classified as unifioral, and the remainder as polifioral.

Effects of leachate on geotechnical characteristics of sandy clay soil

NASA Astrophysics Data System (ADS)

Harun, N. S.; Ali, Z. Rahman; Rahim, A. S.; Lihan, T.; Idris, R. M. W.

2013-11-01

Leachate is a hazardous liquid that poses negative impacts if leaks out into environments such as soil and ground water systems. The impact of leachate on the downgraded quality in terms of chemical characteristic is more concern rather than the physical or mechanical aspect. The effect of leachate on mechanical behaviour of contaminated soil is not well established and should be investigated. This paper presents the preliminary results of the effects of leachate on the Atterberg limit, compaction and shear strength of leachate-contaminated soil. The contaminated soil samples were prepared by mixing the leachate at ratiosbetween 0% and 20% leachate contents with soil samples. Base soil used was residual soil originated from granitic rock and classified as sandy clay soil (CS). Its specific gravity ranged between 2.5 and 2.64 with clay minerals of kaolinite, muscovite and quartz. The field strength of the studied soil ranged between 156 and 207 kN/m2. The effects of leachate on the Atterberg limit clearly indicated by the decrease in liquid and plastic limit values with the increase in the leachate content. Compaction tests on leachate-contaminated soil caused the dropped in maximum dry density, ρdry and increased in optimum moisture content, wopt when the amount of leachate was increased between 0% and 20%. The results suggested that leachate contamination capable to modify some geotechnical properties of the studied residual soils.

Microbial Diagnostic Microarrays for the Detection and Typing of Food- and Water-Borne (Bacterial) Pathogens

PubMed Central

Kostić, Tanja; Sessitsch, Angela

2011-01-01

Reliable and sensitive pathogen detection in clinical and environmental (including food and water) samples is of greatest importance for public health. Standard microbiological methods have several limitations and improved alternatives are needed. Most important requirements for reliable analysis include: (i) specificity; (ii) sensitivity; (iii) multiplexing potential; (iv) robustness; (v) speed; (vi) automation potential; and (vii) low cost. Microarray technology can, through its very nature, fulfill many of these requirements directly and the remaining challenges have been tackled. In this review, we attempt to compare performance characteristics of the microbial diagnostic microarrays developed for the detection and typing of food and water pathogens, and discuss limitations, points still to be addressed and issues specific for the analysis of food, water and environmental samples. PMID:27605332

A large-scale investigation of microplastic contamination: Abundance and characteristics of microplastics in European beach sediment.

PubMed

Lots, Froukje A E; Behrens, Paul; Vijver, Martina G; Horton, Alice A; Bosker, Thijs

2017-10-15

Here we present the large-scale distribution of microplastic contamination in beach sediment across Europe. Sediment samples were collected from 23 locations across 13 countries by citizen scientists, and analysed using a standard operating procedure. We found significant variability in the concentrations of microplastics, ranging from 72±24 to 1512±187 microplastics per kg of dry sediment, with high variability within sampling locations. Three hotspots of microplastic accumulation (>700 microplastics per kg of dry sediment) were found. There was limited variability in the physico-chemical characteristics of the plastics across sampling locations. The majority of the microplastics were fibrous, <1mm in size, and blue/black in colour. In addition, using Raman spectrometry we identified particles as polyester, polyethylene, and polypropylene. Our research is the first large spatial-scale analysis of microplastics on European beaches giving insights into the nature and extent of the microplastic challenge. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of respondent-driven and venue-based sampling of female sex workers in Liuzhou, China

PubMed Central

Weir, Sharon S; Merli, M Giovanna; Li, Jing; Gandhi, Anisha D; Neely, William W; Edwards, Jessie K; Suchindran, Chirayath M; Henderson, Gail E; Chen, Xiang-Sheng

2012-01-01

Objectives To compare two methods for sampling female sex workers (FSWs) for bio-behavioural surveillance. We compared the populations of sex workers recruited by the venue-based Priorities for Local AIDS Control Efforts (PLACE) method and a concurrently implemented network-based sampling method, respondent-driven sampling (RDS), in Liuzhou, China. Methods For the PLACE protocol, all female workers at a stratified random sample of venues identified as places where people meet new sexual partners were interviewed and tested for syphilis. Female workers who reported sex work in the past 4 weeks were categorised as FSWs. RDS used peer recruitment and chain referral to obtain a sample of FSWs. Data were collected between October 2009 and January 2010. We compared the socio-demographic characteristics and the percentage with a positive syphilis test of FSWs recruited by PLACE and RDS. Results The prevalence of a positive syphilis test was 24% among FSWs recruited by PLACE and 8.5% among those recruited by RDS and tested (prevalence ratio 3.3; 95% CI 1.5 to 7.2). Socio-demographic characteristics (age, residence and monthly income) also varied by sampling method. PLACE recruited fewer FSWs than RDS (161 vs 583), was more labour-intensive and had difficulty gaining access to some venues. RDS was more likely to recruit from areas near the RDS office and from large low prevalence entertainment venues. Conclusions Surveillance protocols using different sampling methods can obtain different estimates of prevalence and population characteristics. Venue-based and network-based methods each have strengths and limitations reflecting differences in design and assumptions. We recommend that more research be conducted on measuring bias in bio-behavioural surveillance. PMID:23172350

Assessing the representativeness of physician and patient respondents to a primary care survey using administrative data.

PubMed

Li, Allanah; Cronin, Shawna; Bai, Yu Qing; Walker, Kevin; Ammi, Mehdi; Hogg, William; Wong, Sabrina T; Wodchis, Walter P

2018-05-30

QUALICOPC is an international survey of primary care performance. QUALICOPC data have been used in several studies, yet the representativeness of the Canadian QUALICOPC survey is unknown, potentially limiting the generalizability of findings. This study examined the representativeness of QUALICOPC physician and patient respondents in Ontario using health administrative data. This representativeness study linked QUALICOPC physician and patient respondents in Ontario to health administrative databases at the Institute for Clinical Evaluative Sciences. Physician respondents were compared to other physicians in their practice group and all Ontario primary care physicians on demographic and practice characteristics. Patient respondents were compared to other patients rostered to their primary care physicians, patients rostered to their physicians' practice groups, and a random sample of Ontario residents on sociodemographic characteristics, morbidity, and health care utilization. Standardized differences were calculated to compare the distribution of characteristics across cohorts. QUALICOPC physician respondents included a higher proportion of younger, female physicians and Canadian medical graduates compared to other Ontario primary care physicians. A higher proportion of physician respondents practiced in Family Health Team models, compared to the provincial proportion for primary care physicians. QUALICOPC patient respondents were more likely to be older and female, with significantly higher levels of morbidity and health care utilization, compared with the other patient groups examined. However, when looking at the QUALICOPC physicians' whole rosters, rather than just the patient survey respondents, the practice profiles were similar to those of the other physicians in their practice groups and Ontario patients in general. Comparisons revealed some differences in responding physicians' demographic and practice characteristics, as well as differences in responding patients' characteristics compared to the other patient groups tested, which may have resulted from the visit-based sampling strategy. Ontario QUALICOPC physicians had similar practice profiles as compared to non-participating physicians, providing some evidence that the participating practices are representative of other non-participating practices, and patients selected by visit-based sampling may also be representative of visiting patients in other practices. Those using QUALICOPC data should understand this limited representativeness when generalizing results, and consider the potential for bias in their analyses.

Prediction of porosity of food materials during drying: Current challenges and directions.

PubMed

Joardder, Mohammad U H; Kumar, C; Karim, M A

2017-07-18

Pore formation in food samples is a common physical phenomenon observed during dehydration processes. The pore evolution during drying significantly affects the physical properties and quality of dried foods. Therefore, it should be taken into consideration when predicting transport processes in the drying sample. Characteristics of pore formation depend on the drying process parameters, product properties and processing time. Understanding the physics of pore formation and evolution during drying will assist in accurately predicting the drying kinetics and quality of food materials. Researchers have been trying to develop mathematical models to describe the pore formation and evolution during drying. In this study, existing porosity models are critically analysed and limitations are identified. Better insight into the factors affecting porosity is provided, and suggestions are proposed to overcome the limitations. These include considerations of process parameters such as glass transition temperature, sample temperature, and variable material properties in the porosity models. Several researchers have proposed models for porosity prediction of food materials during drying. However, these models are either very simplistic or empirical in nature and failed to consider relevant significant factors that influence porosity. In-depth understanding of characteristics of the pore is required for developing a generic model of porosity. A micro-level analysis of pore formation is presented for better understanding, which will help in developing an accurate and generic porosity model.

Executive and Reward-Related Function in Pediatric Obesity: A Meta-Analysis.

PubMed

Pearce, Alaina L; Leonhardt, Christine A; Vaidya, Chandan J

2018-06-06

This study examined the effect of pediatric obesity on executive function and reward-related decision-making, cognitive processes that are relevant to obesogenic behaviors, and evaluated their association with sample (e.g., age, gender, intelligence, and socioeconomic status, SES) and study/task (e.g., categorical/continuous variable, food stimuli) characteristics. A random-effects meta-analysis was conducted using Hedge's g effect sizes of published studies from 1960 to 2016, limited to children younger than the age of 21 years without medical comorbidities. Analysis included estimation of heterogeneity (τ 2 ), publication bias (funnel-plot symmetry and fail-safe N), and sensitivity analyses for sample and study/task characteristics. Across 68 studies with 70 samples, obesity was associated with worse functioning overall (-0.24; 95CI: -0.30 to -0.19; p < 0.001) and for each component process (attention, switching, inhibition, interference, working memory, reward, delay of gratification: -0.19 to -0.38; p's < 0.017), except trait impulsivity (-0.06; 95CI: -0.18 to 0.07). Deficits increased with age and female composition of the sample for inhibition (p = 0.002). No other characteristics moderated effect of obesity. Small-to-moderate negative associations with obesity were observed for executive and reward-related performance, but not on reported impulsivity in studies with children younger than the age of 21 years. These results were not moderated by IQ, SES, and study/task characteristics. Age and gender moderated association with inhibition, with a larger obesity-related deficit in older and predominantly female samples. These results suggest cognitive and demographic intervention targets for prevention and mitigation of obesogenic behavior.

RACE AND ETHNIC REPRESENTATIONS OF LAWBREAKERS AND VICTIMS IN CRIME NEWS: A NATIONAL STUDY OF TELEVISION COVERAGE

PubMed Central

Bjornstrom, Eileen E.S.; Kaufman, Robert L.; Peterson, Ruth D.; Slater, Michael D.

2010-01-01

Research on racial-ethnic portrayals in television crime news is limited and questions remain about the sources of representations and how these vary for perpetrators versus victims. We draw from power structure, market share, normal crimes, racial threat, and racial privileging perspectives to further this research. The reported race or ethnicity of violent crime perpetrators and victims are modeled as functions of: (1) situational characteristics of crime stories; and (2) contextual characteristics of television market areas. The primary data are from a stratified random sample of television newscasts in 2002–2003 (Long et al. 2005). An important innovation of our work is the use of a national, more generalizeable, sample of local news stories than prior researchers who tended to focus on single market areas. Results indicate that both the context of the story itself and the social structural context within which news stories are reported are relevant to ethnic and racial portrayals in crime news. We find limited support for power structure, market share, normal crimes and racial threat explanations of patterns of reporting. Racial privileging arguments receive more extensive support. PMID:20640244

"Paper Machine" for Molecular Diagnostics.

PubMed

Connelly, John T; Rolland, Jason P; Whitesides, George M

2015-08-04

Clinical tests based on primer-initiated amplification of specific nucleic acid sequences achieve high levels of sensitivity and specificity. Despite these desirable characteristics, these tests have not reached their full potential because their complexity and expense limit their usefulness to centralized laboratories. This paper describes a device that integrates sample preparation and loop-mediated isothermal amplification (LAMP) with end point detection using a hand-held UV source and camera phone. The prototype device integrates paper microfluidics (to enable fluid handling) and a multilayer structure, or a "paper machine", that allows a central patterned paper strip to slide in and out of fluidic path and thus allows introduction of sample, wash buffers, amplification master mix, and detection reagents with minimal pipetting, in a hand-held, disposable device intended for point-of-care use in resource-limited environments. This device creates a dynamic seal that prevents evaporation during incubation at 65 °C for 1 h. This interval is sufficient to allow a LAMP reaction for the Escherichia coli malB gene to proceed with an analytical sensitivity of 1 double-stranded DNA target copy. Starting with human plasma spiked with whole, live E. coli cells, this paper demonstrates full integration of sample preparation with LAMP amplification and end point detection with a limit of detection of 5 cells. Further, it shows that the method used to prepare sample enables concentration of DNA from sample volumes commonly available from fingerstick blood draw.

Cyclotron resonance spectroscopy in a high mobility two dimensional electron gas using characteristic matrix methods.

PubMed

Hilton, David J

2012-12-31

We develop a new characteristic matrix-based method to analyze cyclotron resonance experiments in high mobility two-dimensional electron gas samples where direct interference between primary and satellite reflections has previously limited the frequency resolution. This model is used to simulate experimental data taken using terahertz time-domain spectroscopy that show multiple pulses from the substrate with a separation of 15 ps that directly interfere in the time-domain. We determine a cyclotron dephasing lifetime of 15.1 ± 0.5 ps at 1.5 K and 5.0 ± 0.5 ps at 75 K.

Polarimetric LIDAR with FRI sampling for target characterization

NASA Astrophysics Data System (ADS)

Wijerathna, Erandi; Creusere, Charles D.; Voelz, David; Castorena, Juan

2017-09-01

Polarimetric LIDAR is a significant tool for current remote sensing applications. In addition, measurement of the full waveform of the LIDAR echo provides improved ranging and target discrimination, although, data storage volume in this approach can be problematic. In the work presented here, we investigated the practical issues related to the implementation of a full waveform LIDAR system to identify polarization characteristics of multiple targets within the footprint of the illumination beam. This work was carried out on a laboratory LIDAR testbed that features a flexible arrangement of targets and the ability to change the target polarization characteristics. Targets with different retardance characteristics were illuminated with a linearly polarized laser beam and the return pulse intensities were analyzed by rotating a linear analyzer polarizer in front of a high-speed detector. Additionally, we explored the applicability and the limitations of applying a sparse sampling approach based on Finite Rate of Innovations (FRI) to compress and recover the characteristic parameters of the pulses reflected from the targets. The pulse parameter values extracted by the FRI analysis were accurate and we successfully distinguished the polarimetric characteristics and the range of multiple targets at different depths within the same beam footprint. We also demonstrated the recovery of an unknown target retardance value from the echoes by applying a Mueller matrix system model.

An Investigation into Heavy Metal Contamination and Mobilization in the Lower Rouge River, Michigan

NASA Astrophysics Data System (ADS)

Shihadeh, M.; Forrester, J.; Napieralski, J. A.

2010-12-01

Similar to many densely populated watersheds in the Great Lakes Basin, the Rouge River in Michigan drains a heavily urbanized watershed, which, over time, has accumulated a substantial amount of contamination due to decades of manufacturing and refining industries. Statistically significant levels of heavy metals have been found in the bed sediment of the Rouge; however, little is known about the mobilization of these contaminated bed sediments. The goal of this study was to ascertain the extent to which these potentially contaminated sediments are mobilized and transported downstream. Suspended sediment samples were collected at four sites along the lower Rouge River using composite depth integrated sediment samples three times per week, resulting in a total of twenty samples from each site. Turbidity was measured simultaneously using a YSI datalogger at all sampling locations. Sediment was also extracted from floodplain soil pits and silted vegetation, as well as river bed sediment cores along stream channel cross-sections. Heavy metal concentrations (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, Se, Zn) were analyzed using ICP-MS and compared against both background characteristics for Michigan soils and EPA Hazardous Criteria Limits. As expected, a positive correlation exists between turbidity and heavy metal concentrations. Even in the sampling sites furthest upstream, heavy metal concentrations exceeded background soil characteristics, with a few also exceeding hazardous criteria limits. The heavy metal concentrations found in the Lower Rouge affirm the elevated pollution classification of the river, depict the overall influence of industrialization on stream health, and verify that contaminated sediments are being deposited in aquatic and floodplain environments during variable flow or high discharge events. Results from this study emphasize the need to remediate bed sediments in the Rouge and suggest that there may be significant bioaccumulation potential for organisms inhabiting the floodplain corridor.

Genotypic Characterization of Cryptosporidium hominis from Water Samples in São Paulo, Brazil

PubMed Central

Araújo, Ronalda S.; Dropa, Milena; Fernandes, Licia N.; Carvalho, Terezinha T.; Sato, Maria Inês Z.; Soares, Rodrigo M.; Matté, Glavur R.; Matté, Maria Helena

2011-01-01

The protozoan parasite Cryptosporidium has emerged as one of the most important water contaminants, causing waterborne outbreaks of diarrheal diseases worldwide. The small size of oocysts under the microscope and the possibility of changes in characteristics of oocysts, mainly in environmental samples, make the taxonomy of the genus difficult if morphologic characteristics are considered. This limitation encouraged the application of molecular methods to identify this microorganism. The aim of this study was to detect and identify by nested-polymerase chain reaction oocysts of Cryptosporidium present in water samples in the state of São Paulo, Brazil. Water samples were concentrated through a membrane filter, DNA was extracted by using a standard technique, and both amplification reactions used forward and reverse oligonucleotides that were complementary to Cryptosporidium 18S ribosomal RNA gene sequences. Thirty water samples from different sites of collection in the state of São Paulo were evaluated. Cryptosporidium oocysts were detected in 30% of the samples. By genoptyping, C. hominis and Cryptosporidium sp. were identified in recreational water and C. meleagridis was identified in surface water samples. This is the first report of C. hominis in environmental samples in Brazil. Although identification of Cryptosporidium is still a difficult task, molecular methods are essential for specific identification and are a helpful tool to aid to understand the epidemiology of this parasite in Brazil. PMID:22049036

Experimental investigation of the quality characteristics of agricultural plastic wastes regarding their recycling and energy recovery potential

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

Briassoulis, D., E-mail: briassou@aua.gr; Hiskakis, M.; Babou, E.

2012-06-15

Highlights: Black-Right-Pointing-Pointer Definition of parameters characterising agricultural plastic waste (APW) quality. Black-Right-Pointing-Pointer Analysis of samples to determine APW quality for recycling or energy recovery. Black-Right-Pointing-Pointer Majority of APW samples from various countries have very good quality for recycling. Black-Right-Pointing-Pointer Upper limit of 50% w/w soil contamination in APW acceptable for energy recovery. Black-Right-Pointing-Pointer Chlorine and heavy metals content in APW below the lowest limit for energy recovery. - Abstract: A holistic environmentally sound waste management scheme that transforms agricultural plastic waste (APW) streams into labelled guaranteed quality commodities freely traded in open market has been developed by the European researchmore » project LabelAgriWaste. The APW quality is defined by the APW material requirements, translated to technical specifications, for recycling or energy recovery. The present work investigates the characteristics of the APW quality and the key factors affecting it from the introduction of the virgin product to the market to the APW stream reaching the disposer. Samples of APW from different countries were traced from their application to the field through their storage phase and transportation to the final destination. The test results showed that the majority of APW retained their mechanical properties after their use preserving a 'very good quality' for recycling in terms of degradation. The degree of soil contamination concerning the APW recycling and energy recovery potential fluctuates depending on the agricultural plastic category and application. The chlorine and heavy metal content of the tested APW materials was much lower than the maximum acceptable limits for their potential use in cement industries.« less

Assessment and associated features of prolonged grief disorder among Chinese bereaved individuals.

PubMed

Li, Jie; Prigerson, Holly G

2016-04-01

Most research on the assessment and characteristics of prolonged grief disorder (PGD) has been conducted in Western bereaved samples. Limited information about PGD in Chinese samples exists. This study aims to validate the Chinese version of the Inventory of Complicated grief (ICG), examine the distinctiveness of PGD symptoms from symptoms of bereavement-related depression and anxiety, and explore the prevalence of PGD in a Chinese sample. Responses from 1358 bereaved Chinese adults were collected through an on-line survey. They completed the Chinese version of ICG and a questionnaire measuring depression and anxiety symptoms. The findings indicate that Chinese ICG has sound validity and high internal consistency. The ICG cut-off score for PGD "caseness"in this large Chinese sample was 48. The distinctiveness of PGD symptoms from those of depression and anxiety was supported by the results of the confirmatory factor analysis and the fact that PGD occurred in isolation in the studied sample. The prevalence of PGD was13.9%. ICG is a valid instrument for use in the Chinese context. Several key characteristics of PGD in Chinese, either different from or comparable to findings in Western samples, may stimulate further research and clinical interest in the concept by providing empirical evidence from an large and influential Eastern country. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantification by SEM-EDS in uncoated non-conducting samples

NASA Astrophysics Data System (ADS)

Galván Josa, V.; Castellano, G.; Bertolino, S. R.

2013-07-01

An approach to perform elemental quantitative analysis in a conventional scanning electron microscope with an energy dispersive spectrometer has been developed for non-conductive samples in which the conductive coating should be avoided. Charge accumulation effects, which basically decrease the energy of the primary beam, were taken into account by means of the Duane-Hunt limit. This value represents the maximum energy of the continuum X-ray spectrum, and is related to the effective energy of the incident electron beam. To validate the results obtained by this procedure, a non-conductive sample of known composition was quantified without conductive coating. Complementarily, changes in the X-ray spectrum due to charge accumulation effects were studied by Monte Carlo simulations, comparing relative characteristic intensities as a function of the incident energy. This methodology is exemplified here to obtain the chemical composition of white and reddish archaeological pigments belonging to the Ambato style of "Aguada" culture (Catamarca, Argentina 500-1100 AD). The results obtained in this work show that the quantification procedure taking into account the Duane-Hunt limit is suitable for this kind of samples. This approach may be recommended for the quantification of samples for which coating is not desirable, such as ancient artwork, forensic or archaeological samples, or when the coating element is also present in the sample.

Menstrual cycle characteristics as determinants of plasma concentrations of perfluoroalkyl substances (PFASs) in the Norwegian Mother and Child Cohort (MoBa study).

PubMed

Singer, Alison B; Whitworth, Kristina W; Haug, Line S; Sabaredzovic, Azemira; Impinen, Antti; Papadopoulou, Eleni; Longnecker, Matthew P

2018-06-04

Perfluoroalkyl substances (PFASs) are fluorinated organic compounds that have been used in a variety of industrial and consumer applications. Menstruation is implicated as a possible route of elimination for PFASs in women. The overall purpose of this study was to examine menstrual cycle characteristics as determinants of plasma PFAS concentrations in women. Our study sample consisted of 1977 pregnant women from the Norwegian Mother and Child Cohort (MoBa) study. The women were asked about menstrual cycle regularity in the year before the pregnancy and typical menstrual cycle length as well as other demographic and reproductive characteristics in a questionnaire completed during the pregnancy. Blood samples were collected around 17-18 weeks gestation and PFAS concentrations were measured in plasma. We examined the association between menstrual cycle characteristics and seven PFASs (perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), and perfluorooctane sulfonate (PFOS)) using multiple linear regression, adjusted for age, pre-pregnancy body mass index, smoking, education, income, parity, oral contraceptive use, inter-pregnancy interval, and breastfeeding duration. Irregular cycles were not associated with PFAS concentrations. Overall, we found no evidence of associations between menstrual cycle length and PFAS concentrations. In subgroup analyses we found some evidence, among parous women, of decreased PFHpS and PFOS with short menstrual cycles; we also found, among recent OC users (in the 12 months before the questionnaire) increased PFNA and PFUnDA with long cycle length. Limitations of our study include misclassification of menstrual cycle characteristics, small sample sizes in the sub-group analyses, and a lack of information on duration and volume of menses. In the entire study sample, we found little evidence of menstrual cycle characteristics as determinants of PFAS concentrations. However, we observed some associations between cycle length and PFAS concentrations with some select PFAS compounds in subgroup analyses. Copyright © 2018 Elsevier Inc. All rights reserved.

Characterization and Analysis of Liquid Waste from Marcellus Shale Gas Development.

PubMed

Shih, Jhih-Shyang; Saiers, James E; Anisfeld, Shimon C; Chu, Ziyan; Muehlenbachs, Lucija A; Olmstead, Sheila M

2015-08-18

Hydraulic fracturing of shale for gas production in Pennsylvania generates large quantities of wastewater, the composition of which has been inadequately characterized. We compiled a unique data set from state-required wastewater generator reports filed in 2009-2011. The resulting data set, comprising 160 samples of flowback, produced water, and drilling wastes, analyzed for 84 different chemicals, is the most comprehensive available to date for Marcellus Shale wastewater. We analyzed the data set using the Kaplan-Meier method to deal with the high prevalence of nondetects for some analytes, and compared wastewater characteristics with permitted effluent limits and ambient monitoring limits and capacity. Major-ion concentrations suggested that most wastewater samples originated from dilution of brines, although some of our samples were more concentrated than any Marcellus brines previously reported. One problematic aspect of this wastewater was the very high concentrations of soluble constituents such as chloride, which are poorly removed by wastewater treatment plants; the vast majority of samples exceeded relevant water quality thresholds, generally by 2-3 orders of magnitude. We also examine the capacity of regional regulatory monitoring to assess and control these risks.

Disentangling Vulnerabilities from Outcomes: Distinctions between Trait Affect and Depressive Symptoms in Adolescent and Adult Samples

PubMed Central

Harding, Kaitlin A.; Willey, Brittany; Ahles, Joshua; Mezulis, Amy

2016-01-01

Background Trait negative affect and trait positive affect are affective vulnerabilities to depressive symptoms in adolescence and adulthood. While trait affect and the state affect characteristic of depressive symptoms are proposed to be theoretically distinct, no studies have established that these constructs are statistically distinct. Therefore, the purpose of the current study was to determine whether the trait affect (e.g. temperament dimensions) that predicts depressive symptoms and the state affect characteristic of depressive symptoms are statistically distinct among early adolescents and adults. We hypothesized that trait negative affect, trait positive affect, and depressive symptoms would represent largely distinct factors in both samples. Method Participants were 268 early adolescents (53.73% female) and 321 young adults (70.09% female) who completed self-report measures of demographic information, trait affect, and depressive symptoms. Results Principal axis factoring with oblique rotation for both samples indicated distinct adolescent factor loadings and overlapping adult factor loadings. Confirmatory factor analyses in both samples supported distinct but related relationships between trait NA, trait PA, and depressive symptoms. Limitations Study limitations include our cross-sectional design that prevented examination of self-reported fluctuations in trait affect and depressive symptoms and the unknown potential effects of self-report biases among adolescents and adults. Conclusions Findings support existing theoretical distinctions between adolescent constructs but highlight a need to revise or remove items to distinguish measurements of adult trait affect and depressive symptoms. Adolescent trait affect and depressive symptoms are statistically distinct, but adult trait affect and depressive symptoms statistically overlap and warrant further consideration. PMID:27085163

A comprehensive literature review of haplotyping software and methods for use with unrelated individuals.

PubMed

Salem, Rany M; Wessel, Jennifer; Schork, Nicholas J

2005-03-01

Interest in the assignment and frequency analysis of haplotypes in samples of unrelated individuals has increased immeasurably as a result of the emphasis placed on haplotype analyses by, for example, the International HapMap Project and related initiatives. Although there are many available computer programs for haplotype analysis applicable to samples of unrelated individuals, many of these programs have limitations and/or very specific uses. In this paper, the key features of available haplotype analysis software for use with unrelated individuals, as well as pooled DNA samples from unrelated individuals, are summarised. Programs for haplotype analysis were identified through keyword searches on PUBMED and various internet search engines, a review of citations from retrieved papers and personal communications, up to June 2004. Priority was given to functioning computer programs, rather than theoretical models and methods. The available software was considered in light of a number of factors: the algorithm(s) used, algorithm accuracy, assumptions, the accommodation of genotyping error, implementation of hypothesis testing, handling of missing data, software characteristics and web-based implementations. Review papers comparing specific methods and programs are also summarised. Forty-six haplotyping programs were identified and reviewed. The programs were divided into two groups: those designed for individual genotype data (a total of 43 programs) and those designed for use with pooled DNA samples (a total of three programs). The accuracy of programs using various criteria are assessed and the programs are categorised and discussed in light of: algorithm and method, accuracy, assumptions, genotyping error, hypothesis testing, missing data, software characteristics and web implementation. Many available programs have limitations (eg some cannot accommodate missing data) and/or are designed with specific tasks in mind (eg estimating haplotype frequencies rather than assigning most likely haplotypes to individuals). It is concluded that the selection of an appropriate haplotyping program for analysis purposes should be guided by what is known about the accuracy of estimation, as well as by the limitations and assumptions built into a program.

Who presents past the gestational age limit for first trimester abortion in the public sector in Mexico City?

PubMed Central

Saavedra-Avendano, Biani; Schiavon, Raffaela; Sanhueza, Patricio; Rios-Polanco, Ranulfo; Garcia-Martinez, Laura; Darney, Blair G.

2018-01-01

Objective To identify socio-demographic factors associated with presenting for abortion services past the gestational age (GA) limit (12 weeks), and thus not receiving services, in Mexico City’s public sector first trimester abortion program. Methods We used clinical data from four high volume sites in the Interrupción Legal de Embarazo (ILE) program, 2007–2015. We used descriptive statistics to quantify the proportion of women who did not receive an abortion due to presenting past the gestational age limit. We used multivariable logistic regression to identify associations between women’s characteristics and presenting past the GA limit and calculated predicted probabilities of late presentation for key characteristics. Results Our sample included 52,391 women, 8.10% (n = 4,246) of whom did not receive abortion services due to presenting past the GA limit. Adolescents (12–17) made up 8.69% of the total sample and 13.40% of those presenting past the GA limit (p< 0.05). In multivariable analyses, all age groups of adult women had significantly lower odds than adolescents of presenting past the limit (aOR = 0.77, aOR = 0.63, aOR = 0.58 and aOR = 0.37 for 19–24, 25–29, 30–39, and > = 40 years’ old respectively). Women living in Mexico City and with higher levels of education had lower odds of presenting past the GA limit, and there was an educational gradient across all age groups. In the multivariable predicted probability models, adolescents at every level of education have significantly higher probabilities of not receiving an abortion due to presenting past the gestational age limit compared with adults (among women with a primary education: 11.75% adolescents vs. 9.02–4.26% across adult age groups). Conclusions Our results suggest that continued efforts are needed to educate women, especially younger and less educated women, about early pregnancy recognition. In addition, all women need information about the availability of first trimester legal abortion to ensure timely access to abortion services. PMID:29414987

Sample Preparation for Mass Spectrometry Imaging of Plant Tissues: A Review

PubMed Central

Dong, Yonghui; Li, Bin; Malitsky, Sergey; Rogachev, Ilana; Aharoni, Asaph; Kaftan, Filip; Svatoš, Aleš; Franceschi, Pietro

2016-01-01

Mass spectrometry imaging (MSI) is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining agents. These advantages make it an attractive molecular histology tool in medical, pharmaceutical, and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of MSI techniques in plants are reviewed according to different classes of plant metabolites. PMID:26904042

Organic Carbon Release from Groundwater Sediments under Changing Geochemical Conditions

NASA Astrophysics Data System (ADS)

Tinnacher, R. M.; Bhattacharyya, A.; Fox, P. M.; Nico, P. S.

2016-12-01

Due to climate change, local weather patterns are expected to change, especially with respect to precipitation, the frequency of extreme storm water events, and `drought-like' conditions. This in turn, may affect groundwater recharge, the geochemical conditions in natural groundwater systems, and the chemical and microbiological processes involved in organic matter degradation. Besides the complexity of organic matter structures and local limitations in nutrients, the association of organic carbon with sediment minerals can strongly limit organic matter bioaccessability and degradability. In this study, we investigate how variations in groundwater chemistry, e.g. with respect to dissolved CO2 concentrations, may potentially affect the release of natural organic carbon from groundwater sediments, and render organic matter more bioaccessible. In lab-scale experiments under anaerobic conditions, aquifer sediments from the floodplain of the Colorado River (Rifle, USA) were brought into contact with fresh, organic-carbon free groundwater solutions, at natural or reduced CO2 concentration levels. During the repeated exchange of solutions at two temperature settings (room-temperature and 4 °C), supernatant solutions were characterized in terms of pH, dissolved metal and organic carbon (OC) concentrations, and potential changes in released OC characteristics. Sediment samples were evaluated for possible differences in Fe-speciation before and after the experiment based on EXAFS (bulk Fe K-edge). Preliminary results for 20 exchanges of groundwater solutions show a repeated release of low OC concentrations ( 0.5-2 mg OC/g sediment; 0.05-0.2% of sediment-associated OC) without any apparent depletion in the overall source term over 50 days. After 14 days, room-temperature samples released slightly higher OC concentrations than samples kept at 4 °C. An increase in solution pH, after switching to a `CO2-free' groundwater solution, did not trigger a higher OC release. Last, specific UV absorbance measurements for room-temperature samples suggest changes in released OC characteristics due to repeated solution exchanges. Additional sample characterization is ongoing, with the goal to elucidate potential changes in released OC characteristics over the course of the experiment.

An electroanalytical approach for evaluation of biochar adsorption characteristics and its application for lead and cadmium determination.

PubMed

Suguihiro, Talita Mayumi; de Oliveira, Paulo Roberto; de Rezende, Edivaltrys Inayve Pissinati; Mangrich, Antonio Sálvio; Marcolino, Luiz Humberto; Bergamini, Márcio F

2013-09-01

This work describes for first time the use of electroanalytical techniques for evaluation of adsorptive proprieties of biochar using it as electrode modifier and its application for preconcentration and determination of Lead(II) and Cadmium(II) under differential pulse adsorptive voltammetric conditions (DPAdSV). Samples of biochars were obtained from castor oil cake using a predefined set of experimental conditions varying the heating rate (V), final temperature (T) and warm-up period (P) and subsequently used for carbon paste modified electrode (CPME) preparation. The proposed method was applied for Lead(II) and Cadmium(II) determination in spiked simulated industrial effluents and the limit of detection obtained for both metals were adequated for determination of these evaluated ions taking into account the limits established by Brazilian legislation. For all samples analyzed, recoveries ranged from 95% to 104% were obtained and no significative interferences were observed for common cations in water samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Towards the estimation of effect measures in studies using respondent-driven sampling.

PubMed

Rotondi, Michael A

2014-06-01

Respondent-driven sampling (RDS) is an increasingly common sampling technique to recruit hidden populations. Statistical methods for RDS are not straightforward due to the correlation between individual outcomes and subject weighting; thus, analyses are typically limited to estimation of population proportions. This manuscript applies the method of variance estimates recovery (MOVER) to construct confidence intervals for effect measures such as risk difference (difference of proportions) or relative risk in studies using RDS. To illustrate the approach, MOVER is used to construct confidence intervals for differences in the prevalence of demographic characteristics between an RDS study and convenience study of injection drug users. MOVER is then applied to obtain a confidence interval for the relative risk between education levels and HIV seropositivity and current infection with syphilis, respectively. This approach provides a simple method to construct confidence intervals for effect measures in RDS studies. Since it only relies on a proportion and appropriate confidence limits, it can also be applied to previously published manuscripts.

Estimation of Snow Parameters from Dual-Wavelength Airborne Radar

NASA Technical Reports Server (NTRS)

Liao, Liang; Meneghini, Robert; Iguchi, Toshio; Detwiler, Andrew

1997-01-01

Estimation of snow characteristics from airborne radar measurements would complement In-situ measurements. While In-situ data provide more detailed information than radar, they are limited in their space-time sampling. In the absence of significant cloud water contents, dual-wavelength radar data can be used to estimate 2 parameters of a drop size distribution if the snow density is assumed. To estimate, rather than assume, a snow density is difficult, however, and represents a major limitation in the radar retrieval. There are a number of ways that this problem can be investigated: direct comparisons with in-situ measurements, examination of the large scale characteristics of the retrievals and their comparison to cloud model outputs, use of LDR measurements, and comparisons to the theoretical results of Passarelli(1978) and others. In this paper we address the first approach and, in part, the second.

Methods of analysis by the U. S. Geological Survey National Water Quality Laboratory - determination of organonitrogen herbicides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

USGS Publications Warehouse

Sandstrom, Mark W.; Wydoski, Duane S.; Schroeder, Michael P.; Zamboni, Jana L.; Foreman, William T.

1992-01-01

A method for the isolation of organonitrogen herbicides from natural water samples using solid-phase extraction and analysis by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction cartridges containing octadecyl-bonded porous silica to remove the herbicides. The cartridges are dried using carbon dioxide, and adsorbed herbicides are removed from the cartridges by elution with 1.8 milliliters of hexaneisopropanol (3:1). Extracts of the eluants are analyzed by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of at least three characteristic ions. The method detection limits are dependent on sample matrix and each particular herbicide. The method detection limits, based on a 100-milliliter sample size, range from 0.02 to 0.25 microgram per liter. Recoveries averaged 80 to 115 percent for the 23 herbicides and 2 metabolites in 1 reagent-water and 2 natural-water samples fortified at levels of 0.2 and 2.0 micrograms per liter.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses

PubMed Central

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-01-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51–92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research. PMID:23635867

Health-related characteristics of men who have sex with men: a comparison of those living in "gay ghettos" with those living elsewhere.

PubMed Central

Mills, T C; Stall, R; Pollack, L; Paul, J P; Binson, D; Canchola, J; Catania, J A

2001-01-01

OBJECTIVES: This study investigated the limitations of probability samples of men who have sex with men (MSM), limited to single cities and to the areas of highest concentrations of MSM ("gay ghettos"). METHODS: A probability sample of 2881 MSM in 4 American cities completed interviews by telephone. RESULTS: MSM who resided in ghettos differed from other MSM, although in different ways in each city. Non-ghetto-dwelling MSM were less involved in the gay and lesbian community. They were also less likely to have only male sexual partners, to identify as gay, and to have been tested for HIV. CONCLUSIONS: These differences between MSM who live in gay ghettos and those who live elsewhere have clear implications for HIV prevention efforts and health care planning. PMID:11392945

Can we predict the outcome for people with patellofemoral pain? A systematic review on prognostic factors and treatment effect modifiers.

PubMed

Matthews, M; Rathleff, M S; Claus, A; McPoil, T; Nee, R; Crossley, K; Vicenzino, B

2017-12-01

Patellofemoral pain (PFP) is a multifactorial and often persistent knee condition. One strategy to enhance patient outcomes is using clinically assessable patient characteristics to predict the outcome and match a specific treatment to an individual. A systematic review was conducted to determine which baseline patient characteristics were (1) associated with patient outcome (prognosis); or (2) modified patient outcome from a specific treatment (treatment effect modifiers). 6 electronic databases were searched (July 2016) for studies evaluating the association between those with PFP, their characteristics and outcome. All studies were appraised using the Epidemiological Appraisal Instrument. Studies that aimed to identify treatment effect modifiers underwent a checklist for methodological quality. The 24 included studies evaluated 180 participant characteristics. 12 studies investigated prognosis, and 12 studies investigated potential treatment effect modifiers. Important methodological limitations were identified. Some prognostic studies used a retrospective design. Studies aiming to identify treatment effect modifiers often analysed too many variables for the limiting sample size and typically failed to use a control or comparator treatment group. 16 factors were reported to be associated with a poor outcome, with longer duration of symptoms the most reported (>4 months). Preliminary evidence suggests increased midfoot mobility may predict those who have a successful outcome to foot orthoses. Current evidence can identify those with increased risk of a poor outcome, but methodological limitations make it difficult to predict the outcome after one specific treatment compared with another. Adequately designed randomised trials are needed to identify treatment effect modifiers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Improvement of direct determination of trace nickel in environmental samples by diffuse reflection spectroscopy using chromaticity characteristics.

PubMed

Ershova, N I; Ivanov, V M

2000-05-01

Cellulose and chromaton-N-super as solid supports for direct determination of the immobilized nickel complexes with dimethylglyoxime and benzyldioxime by diffuse reflection spectroscopy were compared. The advantage of chromaton-N-super with use of benzyldioxime is shown. Detection limit is 0.02 microg/mL. The proposed method was applied for the analysis of soil.

Multispot single-molecule FRET: High-throughput analysis of freely diffusing molecules

PubMed Central

Panzeri, Francesco

2017-01-01

We describe an 8-spot confocal setup for high-throughput smFRET assays and illustrate its performance with two characteristic experiments. First, measurements on a series of freely diffusing doubly-labeled dsDNA samples allow us to demonstrate that data acquired in multiple spots in parallel can be properly corrected and result in measured sample characteristics consistent with those obtained with a standard single-spot setup. We then take advantage of the higher throughput provided by parallel acquisition to address an outstanding question about the kinetics of the initial steps of bacterial RNA transcription. Our real-time kinetic analysis of promoter escape by bacterial RNA polymerase confirms results obtained by a more indirect route, shedding additional light on the initial steps of transcription. Finally, we discuss the advantages of our multispot setup, while pointing potential limitations of the current single laser excitation design, as well as analysis challenges and their solutions. PMID:28419142

Informing water harvesting technology contract design using choice experiments

NASA Astrophysics Data System (ADS)

Tarfasa, Solomon; Brouwer, Roy; Sheremet, Oleg; Bouma, Jetske

2017-10-01

Introducing water harvesting technology is expected to be more effective and last longer if farm households are involved in their design. The main objective of this study is to inform policymakers in Ethiopia about the most important terms and conditions to incentivize farmers to enter into a contractual agreement to invest in water harvesting on their land. In order to test the influence of the way the specific contractual terms and conditions are communicated to farm households, many of whom are illiterate, a split sample approach is applied with and without visual aids for technical, institutional, and economic contract characteristics. Both samples generate significantly different results, highlighting the importance of how information is conveyed to farm households. This pattern is confirmed when examining the self-reported importance attached to the various contract characteristics. Equality Constrained Latent Class models show that contract characteristics for which visual aids were developed are considered more attentively, emphasizing the importance of adequate communication tools in a developing country context where literacy rates are limited to increase water technology innovation uptake and reduce farm household vulnerability to droughts.

Nondestructive strain depth profiling with high energy X-ray diffraction: System capabilities and limitations

NASA Astrophysics Data System (ADS)

Zhang, Zhan; Wendt, Scott; Cosentino, Nicholas; Bond, Leonard J.

2018-04-01

Limited by photon energy, and penetration capability, traditional X-ray diffraction (XRD) strain measurements are only capable of achieving a few microns depth due to the use of copper (Cu Kα1) or molybdenum (Mo Kα1) characteristic radiation. For deeper strain depth profiling, destructive methods are commonly necessary to access layers of interest by removing material. To investigate deeper depth profiles nondestructively, a laboratory bench-top high-energy X-ray diffraction (HEXRD) system was previously developed. This HEXRD method uses an industrial 320 kVp X-Ray tube and the Kα1 characteristic peak of tungsten, to produces a higher intensity X-ray beam which enables depth profiling measurement of lattice strain. An aluminum sample was investigated with deformation/load provided using a bending rig. It was shown that the HEXRD method is capable of strain depth profiling to 2.5 mm. The method was validated using an aluminum sample where both the HEXRD method and the traditional X-ray diffraction method gave data compared with that obtained using destructive etching layer removal, performed by a commercial provider. The results demonstrate comparable accuracy up to 0.8 mm depth. Nevertheless, higher attenuation capabilities in heavier metals limit the applications in other materials. Simulations predict that HEXRD works for steel and nickel in material up to 200 µm, but experiment results indicate that the HEXRD strain profile is not practical for steel and nickel material, and the measured diffraction signals are undetectable when compared to the noise.

Integral imaging based light field display with enhanced viewing resolution using holographic diffuser

NASA Astrophysics Data System (ADS)

Yan, Zhiqiang; Yan, Xingpeng; Jiang, Xiaoyu; Gao, Hui; Wen, Jun

2017-11-01

An integral imaging based light field display method is proposed by use of holographic diffuser, and enhanced viewing resolution is gained over conventional integral imaging systems. The holographic diffuser is fabricated with controlled diffusion characteristics, which interpolates the discrete light field of the reconstructed points to approximate the original light field. The viewing resolution can thus be improved and independent of the limitation imposed by Nyquist sampling frequency. An integral imaging system with low Nyquist sampling frequency is constructed, and reconstructed scenes of high viewing resolution using holographic diffuser are demonstrated, verifying the feasibility of the method.

Sampling methods for microbiological analysis of red meat and poultry carcasses.

PubMed

Capita, Rosa; Prieto, Miguel; Alonso-Calleja, Carlos

2004-06-01

Microbiological analysis of carcasses at slaughterhouses is required in the European Union for evaluating the hygienic performance of carcass production processes as required for effective hazard analysis critical control point implementation. The European Union microbial performance standards refer exclusively to the excision method, even though swabbing using the wet/dry technique is also permitted when correlation between both destructive and nondestructive methods can be established. For practical and economic reasons, the swab technique is the most extensively used carcass surface-sampling method. The main characteristics, advantages, and limitations of the common excision and swabbing methods are described here.

A new facility for non-destructive assay using a 252Cf source.

PubMed

Stevanato, L; Caldogno, M; Dima, R; Fabris, D; Hao, Xin; Lunardon, M; Moretto, S; Nebbia, G; Pesente, S; Pino, F; Sajo-Bohus, L; Viesti, G

2013-03-01

A new laboratory facility for non-destructive analysis (NDA) using a time-tagged (252)Cf source is presented. The system is designed to analyze samples having maximum size of about 20 × 25 cm(2), the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Survey of what is published on Italian nursing journals].

PubMed

Bongiorno, Elena; Colleoni, Pasqualina; Casati, Monica

2005-01-01

Nursing research is an important activity for nurses; the main aim is to improve the quality of nursing. Several national and european laws have been issued about it. To develop knowledge about nursing, nurses have to understand the results of researches, implement them in the different situation and sometimes carry out researches. The results can be published in nursing journals which a lot of nurses use to share information. This study reviewed the characteristics of research articles published in italian nursing journals from 1998 to 2003. Phenomena of interest are: areas of enquiry, investigators, methods, research design, sampling and means to gather data. 122 articles have been reviewed: 78% focus on clinical aspects, 55% were carry out by nurses, 92% adopt the quantitative approach, 90% used non experimental design, 89% used convenience selection sampling method and 58% answer ways. The characteristics of this study are similar to other studies about italian nursing publication. There are some limits in this type of literature: lower generalization because of lower representativeness of sample, convenience selection sampling method, and higher risk of interference due to frequent use of non experimental design. However the number of italian nurses that carry out researches is increasing and nursing is the most studied area.

Plutonium and uranium determination in environmental samples: combined solvent extraction-liquid scintillation method.

PubMed

McDowell, W J; Farrar, D T; Billings, M R

1974-12-01

A method for the determination of uranium and plutonium by a combined high-resolution liquid scintillation-solvent extraction method is presented. Assuming a sample count equal to background count to be the detection limit, the lower detection limit for these and other alpha-emitting nuclides is 1.0 dpm with a Pyrex sample tube, 0.3 dpm with a quartz sample tube using present detector shielding or 0.02 d.p.m. with pulse-shape discrimination. Alpha-counting efficiency is 100%. With the counting data presented as an alpha-energy spectrum, an energy resolution of 0.2-0.3 MeV peak half-width and an energy identification to +/-0.1 MeV are possible. Thus, within these limits, identification and quantitative determination of a specific alpha-emitter, independent of chemical separation, are possible. The separation procedure allows greater than 98% recovery of uranium and plutonium from solution containing large amounts of iron and other interfering substances. In most cases uranium, even when present in 10(8)-fold molar ratio, may be quantitatively separated from plutonium without loss of the plutonium. Potential applications of this general analytical concept to other alpha-counting problems are noted. Special problems associated with the determination of plutonium in soil and water samples are discussed. Results of tests to determine the pulse-height and energy-resolution characteristics of several scintillators are presented. Construction of the high-resolution liquid scintillation detector is described.

Participatory research with an online drug forum: a survey of user characteristics, information sharing, and harm reduction views.

PubMed

Chiauzzi, Emil; Dasmahapatra, Pronabesh; Lobo, Kimberly; Barratt, Monica J

2013-06-01

Visitors to a popular online drug forum completed an online survey between November 2011 and January 2012, which covered (1) demographic characteristics, (2) substance use (including nonmedical prescription opioid use), (3) forum activity, and (4) harm reduction beliefs. The study sample (N = 897) primarily included Caucasian males in their twenties from the United States, the United Kingdom, Australia, and Canada. The practice of harm reduction was overwhelmingly endorsed by participants. Current nonmedical prescription opioid users reported more activity in forums and past substance abuse treatment. The study's implications and limitations are noted and future research is suggested.

Determination of the functioning parameters in asymmetrical flow field-flow fractionation with an exponential channel.

PubMed

Déjardin, P

2013-08-30

The flow conditions in normal mode asymmetric flow field-flow fractionation are determined to approach the high retention limit with the requirement d≪l≪w, where d is the particle diameter, l the characteristic length of the sample exponential distribution and w the channel height. The optimal entrance velocity is determined from the solute characteristics, the channel geometry (exponential to rectangular) and the membrane properties, according to a model providing the velocity fields all over the cell length. In addition, a method is proposed for in situ determination of the channel height. Copyright © 2013 Elsevier B.V. All rights reserved.

Performance of an in-house human immunodeficiency virus type 1 genotyping system for assessment of drug resistance in Cuba.

PubMed

Alemán, Yoan; Vinken, Lore; Kourí, Vivian; Pérez, Lissette; Álvarez, Alina; Abrahantes, Yeissel; Fonseca, Carlos; Pérez, Jorge; Correa, Consuelo; Soto, Yudira; Schrooten, Yoeri; Vandamme, Anne-Mieke; Van Laethem, Kristel

2015-01-01

As commercial human immunodeficiency virus type 1 drug resistance assays are expensive, they are not commonly used in resource-limited settings. Hence, a more affordable in-house procedure was set up taking into account the specific epidemiological and economic circumstances of Cuba. The performance characteristics of the in-house assay were evaluated using clinical samples with various subtypes and resistance patterns. The lower limit of amplification was determined on dilutions series of 20 clinical isolates and ranged from 84 to 529 RNA copies/mL. For the assessment of trueness, 14 clinical samples were analyzed and the ViroSeq HIV-1 Genotyping System v2.0 was used as the reference standard. The mean nucleotide sequence identity between the two assays was 98.7% ± 1.0. Additionally, 99.0% of the amino acids at drug resistance positions were identical. The sensitivity and specificity in detecting drug resistance mutations was respectively 94.1% and 99.5%. Only few discordances in drug resistance interpretation patterns were observed. The repeatability and reproducibility were evaluated using 10 clinical samples with 3 replicates per sample. The in-house test was very precise as nucleotide sequence identity among paired nucleotide sequences ranged from 98.7% to 99.9%. The acceptance criteria were met by the in-house test for all performance characteristics, demonstrating a high degree of accuracy. Subsequently, the applicability in routine clinical practice was evaluated on 380 plasma samples. The amplification success rate was 91% and good quality consensus sequences encoding the entire protease and the first 335 codons in reverse transcriptase could be obtained for 99% of the successful amplicons. The reagent cost per sample using the in-house procedure was around € 80 per genotyping attempt. Overall, the in-house assay provided good results, was feasible with equipment and reagents available in Cuba and was half as expensive as commercial assays.

Partitioning behavior of heavy metals and persistent organic pollutants among feto-maternal bloods and tissues.

PubMed

Kim, Jun-Tae; Son, Min-Hui; Lee, Duk-Hee; Seong, Won Joon; Han, Seunghee; Chang, Yoon-Seok

2015-06-16

Heavy metals and persistent organic pollutants (POPs), including Pb, Cd, T-Hg, MeHg, PCDD/Fs, PCBs, PBDEs, PCNs, and PBDD/Fs, were analyzed in 20 paired samples of cord blood, maternal blood, maternal urine, and placenta. The samples were collected from pregnant mothers and neonates from South Korea in 2010. The distribution of heavy metals among the samples varied with their physicochemical characteristics. The concentrations of Pb and Hg in the maternal and the cord blood samples were significantly correlated each other, implying efficient transplacental transport (TPT). Cd and Hg were accumulated in the placenta, forming protein conjugates, and T-Hg was higher in the cord blood samples than the maternal blood samples due to the binding affinity of Hg with fetal proteins. POPs generally showed the highest concentrations in the maternal serum samples, and the POPs levels in the cord serum and the placenta samples were dependent on the degree of halogenation. The TPT of POPs was seemingly related to lipoprotein transportation. Some PBDE congeners, however, showed their highest concentrations in the cord serum samples, suggesting an additional TPT mechanism. This is the first study to detect PCNs and PBDD/Fs in the cord serum samples, showing that the PCN levels were comparable to other POPs. According to the principal component analysis (PCA) results of the contaminant levels, POPs and heavy metals showed significantly different characteristics, whereas PBDEs had an intermediate attribute. Despite the limited number of participants, the comprehensive analysis of trace contaminants in the paired sample sets enabled us to infer the distribution and TPT mechanism of various contaminants.

Development of spatial scaling technique of forest health sample point information

NASA Astrophysics Data System (ADS)

Lee, J.; Ryu, J.; Choi, Y. Y.; Chung, H. I.; Kim, S. H.; Jeon, S. W.

2017-12-01

Most forest health assessments are limited to monitoring sampling sites. The monitoring of forest health in Britain in Britain was carried out mainly on five species (Norway spruce, Sitka spruce, Scots pine, Oak, Beech) Database construction using Oracle database program with density The Forest Health Assessment in GreatBay in the United States was conducted to identify the characteristics of the ecosystem populations of each area based on the evaluation of forest health by tree species, diameter at breast height, water pipe and density in summer and fall of 200. In the case of Korea, in the first evaluation report on forest health vitality, 1000 sample points were placed in the forests using a systematic method of arranging forests at 4Km × 4Km at regular intervals based on an sample point, and 29 items in four categories such as tree health, vegetation, soil, and atmosphere. As mentioned above, existing researches have been done through the monitoring of the survey sample points, and it is difficult to collect information to support customized policies for the regional survey sites. In the case of special forests such as urban forests and major forests, policy and management appropriate to the forest characteristics are needed. Therefore, it is necessary to expand the survey headquarters for diagnosis and evaluation of customized forest health. For this reason, we have constructed a method of spatial scale through the spatial interpolation according to the characteristics of each index of the main sample point table of 29 index in the four points of diagnosis and evaluation report of the first forest health vitality report, PCA statistical analysis and correlative analysis are conducted to construct the indicators with significance, and then weights are selected for each index, and evaluation of forest health is conducted through statistical grading.

Multi-Frequency Signal Detection Based on Frequency Exchange and Re-Scaling Stochastic Resonance and Its Application to Weak Fault Diagnosis.

PubMed

Liu, Jinjun; Leng, Yonggang; Lai, Zhihui; Fan, Shengbo

2018-04-25

Mechanical fault diagnosis usually requires not only identification of the fault characteristic frequency, but also detection of its second and/or higher harmonics. However, it is difficult to detect a multi-frequency fault signal through the existing Stochastic Resonance (SR) methods, because the characteristic frequency of the fault signal as well as its second and higher harmonics frequencies tend to be large parameters. To solve the problem, this paper proposes a multi-frequency signal detection method based on Frequency Exchange and Re-scaling Stochastic Resonance (FERSR). In the method, frequency exchange is implemented using filtering technique and Single SideBand (SSB) modulation. This new method can overcome the limitation of "sampling ratio" which is the ratio of the sampling frequency to the frequency of target signal. It also ensures that the multi-frequency target signals can be processed to meet the small-parameter conditions. Simulation results demonstrate that the method shows good performance for detecting a multi-frequency signal with low sampling ratio. Two practical cases are employed to further validate the effectiveness and applicability of this method.

Seasonal and local differences in leaf litter flammability of six Mediterranean tree species.

PubMed

Kauf, Zorica; Fangmeier, Andreas; Rosavec, Roman; Španjol, Željko

2015-03-01

One of the suggested management options for reducing fire danger is the selection of less flammable plant species. Nevertheless, vegetation flammability is both complex and dynamic, making identification of such species challenging. While large efforts have been made to connect plant traits to fire behavior, seasonal changes and within species variability of traits are often neglected. Currently, even the most sophisticated fire danger systems presume that intrinsic characteristics of leaf litter stay unchanged, and plant species flammability lists are often transferred from one area to another. In order to assess if these practices can be improved, we performed a study examining the relationship between morphological characteristics and flammability parameters of leaf litter, thereby taking into account seasonal and local variability. Litter from six Mediterranean tree species was sampled throughout the fire season from three different locations along a climate gradient. Samples were subjected to flammability testing involving an epiradiator operated at 400 °C surface temperature with 3 g sample weight. Specific leaf area, fuel moisture content, average area, and average mass of a single particle had significant influences on flammability parameters. Effects of sampling time and location were significant as well. Due to the standardized testing conditions, these effects could be attributed to changes in intrinsic characteristics of the material. As the aforementioned effects were inconsistent and species specific, these results may potentially limit the generalization of species flammability rankings. Further research is necessary in order to evaluate the importance of our findings for fire danger modeling.

Characteristics and composition of watermelon, pumpkin, and paprika seed oils and flours.

PubMed

El-Adawy, T A; Taha, K M

2001-03-01

The nutritional quality and functional properties of paprika seed flour and seed kernel flours of pumpkin and watermelon were studied, as were the characteristics and structure of their seed oils. Paprika seed and seed kernels of pumpkin and watermelon were rich in oil and protein. All flour samples contained considerable amounts of P, K, Mg, Mn, and Ca. Paprika seed flour was superior to watermelon and pumpkin seed kernel flours in content of lysine and total essential amino acids. Oil samples had high amounts of unsaturated fatty acids with linoleic and oleic acids as the major acids. All oil samples fractionated into seven classes including triglycerides as a major lipid class. Data obtained for the oils' characteristics compare well with those of other edible oils. Antinutritional compounds such as stachyose, raffinose, verbascose, trypsin inhibitor, phytic acid, and tannins were detected in all flours. Pumpkin seed kernel flour had higher values of chemical score, essential amino acid index, and in vitro protein digestibility than the other flours examined. The first limiting amino acid was lysine for both watermelon and pumpkin seed kernel flours, but it was leucine in paprika seed flour. Protein solubility index, water and fat absorption capacities, emulsification properties, and foam stability were excellent in watermelon and pumpkin seed kernel flours and fairly good in paprika seed flour. Flour samples could be potentially added to food systems such as bakery products and ground meat formulations not only as a nutrient supplement but also as a functional agent in these formulations.

Homeostatic and Circadian Abnormalities in Sleep and Arousal in Gulf War Syndrome

DTIC Science & Technology

2013-10-01

temperature, melatonin , vigilance 16. SECURITY CLASSIFICATION OF: U 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON...analysis of slow wave characteristics, origin and propagation. Circadian rhythm is also assessed, including temperature and salivary melatonin ...to note diurnal changes, as well as morning cortisol rise from natural wake. We also have collected melatonin samples in a low light environment to

Task-based optimization of flip angle for fibrosis detection in T1-weighted MRI of liver

PubMed Central

Brand, Jonathan F.; Furenlid, Lars R.; Altbach, Maria I.; Galons, Jean-Philippe; Bhattacharyya, Achyut; Sharma, Puneet; Bhattacharyya, Tulshi; Bilgin, Ali; Martin, Diego R.

2016-01-01

Abstract. Chronic liver disease is a worldwide health problem, and hepatic fibrosis (HF) is one of the hallmarks of the disease. The current reference standard for diagnosing HF is biopsy followed by pathologist examination; however, this is limited by sampling error and carries a risk of complications. Pathology diagnosis of HF is based on textural change in the liver as a lobular collagen network that develops within portal triads. The scale of collagen lobules is characteristically in the order of 1 to 5 mm, which approximates the resolution limit of in vivo gadolinium-enhanced magnetic resonance imaging in the delayed phase. We use MRI of formalin-fixed human ex vivo liver samples as phantoms that mimic the textural contrast of in vivo Gd-MRI. We have developed a local texture analysis that is applied to phantom images, and the results are used to train model observers to detect HF. The performance of the observer is assessed with the area-under-the-receiver–operator-characteristic curve (AUROC) as the figure-of-merit. To optimize the MRI pulse sequence, phantoms were scanned with multiple times at a range of flip angles. The flip angle that was associated with the highest AUROC was chosen as optimal for the task of detecting HF. PMID:27446971

Sources of Variation on the Mini-Mental State Examination in a Population-Based Sample of Centenarians

PubMed Central

Dai, Ting; Davey, Adam; Woodard, John L.; Miller, L. Stephen; Gondo, Yasuyuki; Kim, Seock-Ho; Poon, Leonard W.

2013-01-01

Centenarians represent a rare but rapidly growing segment of the oldest-old. This study presents item-level data from the Mini-Mental State Examination (MMSE, M=16.2, SD=8.8, Range 0–30) in a cross-sectional, population-based sample of 244 centenarians and near-centenarians (aged 98–108, 16% men, 21% African-American, 38% community-dwelling) from the Georgia Centenarian Study (2001–2008) by age, education, sex, race, and residential status. Multiple-Indicator Multiple-Causes (MIMIC) models were used to identify systematic domain-level differences on MMSE scores by key demographic characteristics in this age group. Indirect effects of age, educational attainment, race, and residential status were found on MMSE scores. Direct effects were limited to concentration for education and race, and orientation for residential status. Mean levels of cognitive functioning in centenarians were low, with mean values below most commonly-used cut-offs. Overall scores on the MMSE differed as a function of age, education, race, and residential status, with differences in scale performance limited primarily to concentration and orientation, with no evidence for interactions among centenarian characteristics. Adjusting for education was not sufficient to account for differences by race; adjusting for residential status was not sufficient to account for differences by age. PMID:23889552

Observed circuit limits to time resolution in correlation measurements with Si-on-sapphire, GaAs, and InP picosecond photoconductors

NASA Astrophysics Data System (ADS)

Hammond, R. B.; Paulter, N. G.; Wagner, R. S.

1984-08-01

Cross-correlation measurements of the response of photoconductor pulsers and sampling gates excited by a femtosecond laser are reported. The photoconductors were fabricated in microstrip transmission line structures on Si-on-sapphire, semiinsulating GaAs, and semiinsulating InP wafers. The photoconductor sampling gates were ion beam-damaged to produce short carrier lifetimes (less than 3 ps in one case). Damage was introduced with 6 MeV Ne-20 on the Si-on-sapphire, 2 MeV H-2 on the GaAs, and 2 MeV He-4 on the InP. Doses in the range 10 to the 12th - 10 to the 15th were used. Results show circuit limits to the time resolution in correlation measurements from two sources: (1) RC time constants due to photoconductor gap capacitance and transmission line characteristic impedance and (2) dispersion in microstrip transmission lines.

Evaluation of the synoptic and mesoscale predictive capabilities of a mesoscale atmospheric simulation system

NASA Technical Reports Server (NTRS)

Koch, S. E.; Skillman, W. C.; Kocin, P. J.; Wetzel, P. J.; Brill, K.; Keyser, D. A.; Mccumber, M. C.

1983-01-01

The overall performance characteristics of a limited area, hydrostatic, fine (52 km) mesh, primitive equation, numerical weather prediction model are determined in anticipation of satellite data assimilations with the model. The synoptic and mesoscale predictive capabilities of version 2.0 of this model, the Mesoscale Atmospheric Simulation System (MASS 2.0), were evaluated. The two part study is based on a sample of approximately thirty 12h and 24h forecasts of atmospheric flow patterns during spring and early summer. The synoptic scale evaluation results benchmark the performance of MASS 2.0 against that of an operational, synoptic scale weather prediction model, the Limited area Fine Mesh (LFM). The large sample allows for the calculation of statistically significant measures of forecast accuracy and the determination of systematic model errors. The synoptic scale benchmark is required before unsmoothed mesoscale forecast fields can be seriously considered.

Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage.

PubMed

Ginson, J; Panda, Satyen Kumar; Bindu, J; Kamalakanth, C K; Srinivasa Gopal, T K

2015-04-01

High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p < 0.05). There was delay in the growth of Enterobacteriaceae and H2S producing bacteria up to 6th and 9th day of storage, respectively in high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Association between productivity, list size, patient and practice characteristics in general practice].

PubMed

Olsen, Kim Rose; Sørensen, Torben Højmark; Gyrd-Hansen, Dorte

2010-04-19

Due to shortage of general practitioners, it may be necessary to improve productivity. We assess the association between productivity, list size and patient- and practice characteristics. A regression approach is used to perform productivity analysis based on national register data and survey data for 1,758 practices. Practices are divided into four groups according to list size and productivity. Statistical tests are used to assess differences in patient- and practice characteristics. There is a significant, positive correlation between list size and productivity (p < 0.01). Nevertheless, 19% of the practices have a list size below and a productivity above mean sample values. These practices have relatively demanding patients (older, low socioeconomic status, high use of pharmaceuticals) and they are frequently located in areas with limited access to specialized care and have a low use of assisting personnel. 13% of the practices have a list size above and a productivity below mean sample values. These practices have relatively less demanding patients, are located in areas with good access to specialized care, and have a high use of assisting personnel. Lists and practice characteristics have substantial influence on both productivity and list size. Adjusting list size to external factors seems to be an effective tool to increase productivity in general practice.

A modified siphon sampler for shallow water

USGS Publications Warehouse

Diehl, Timothy H.

2008-01-01

A modified siphon sampler (or 'single-stage sampler') was developed to sample shallow water at closely spaced vertical intervals. The modified design uses horizontal rather than vertical sample bottles. Previous siphon samplers are limited to water about 20 centimeters (cm) or more in depth; the modified design can sample water 10 cm deep. Several mounting options were used to deploy the modified siphon sampler in shallow bedrock streams of Middle Tennessee, while minimizing alteration of the stream bed. Sampling characteristics and limitations of the modified design are similar to those of the original design. Testing showed that the modified sampler collects unbiased samples of suspended silt and clay. Similarity of the intake to the original siphon sampler suggests that the modified sampler would probably take downward-biased samples of suspended sand. Like other siphon samplers, it does not sample isokinetically, and the efficiency of sand sampling can be expected to change with flow velocity. The sampler needs to be located in the main flow of the stream, and is subject to damage from rapid flow and floating debris. Water traps were added to the air vents to detect the flow of water through the sampler, which can cause a strong upward bias in sampled suspended-sediment concentration. Water did flow through the sampler, in some cases even when the top of the air vent remained above water. Air vents need to be extended well above maximum water level to prevent flow through the sampler.

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples.

PubMed

Hong, Hyobong; Lim, Eul-Gyoon; Jeong, Jae-Chan; Chang, Jiho; Shin, Sung-Woong; Krause, Hans-Joachim

2016-06-09

The setup of a planar Frequency Mixing Magnetic Detection (p-FMMD) scanner for performing Magnetic Particles Imaging (MPI) of flat samples is presented. It consists of two magnetic measurement heads on both sides of the sample mounted on the legs of a u-shaped support. The sample is locally exposed to a magnetic excitation field consisting of two distinct frequencies, a stronger component at about 77 kHz and a weaker field at 61 Hz. The nonlinear magnetization characteristics of superparamagnetic particles give rise to the generation of intermodulation products. A selected sum-frequency component of the high and low frequency magnetic field incident on the magnetically nonlinear particles is recorded by a demodulation electronics. In contrast to a conventional MPI scanner, p-FMMD does not require the application of a strong magnetic field to the whole sample because mixing of the two frequencies occurs locally. Thus, the lateral dimensions of the sample are just limited by the scanning range and the supports. However, the sample height determines the spatial resolution. In the current setup it is limited to 2 mm. As examples, we present two 20 mm × 25 mm p-FMMD images acquired from samples with 1 µm diameter maghemite particles in silanol matrix and with 50 nm magnetite particles in aminosilane matrix. The results show that the novel MPI scanner can be applied for analysis of thin biological samples and for medical diagnostic purposes.

Community-Level Physiological Profiling of Microbial Communities in Constructed Wetlands: Effects of Sample Preparation.

PubMed

Button, Mark; Weber, Kela; Nivala, Jaime; Aubron, Thomas; Müller, Roland Arno

2016-03-01

Community-level physiological profiling (CLPP) using BIOLOG® EcoPlates™ has become a popular method for characterizing and comparing the functional diversity, functional potential, and metabolic activity of heterotrophic microbial communities. The method was originally developed for profiling soil communities; however, its usage has expanded into the fields of ecotoxicology, agronomy, and the monitoring and profiling of microbial communities in various wastewater treatment systems, including constructed wetlands for water pollution control. When performing CLPP on aqueous samples from constructed wetlands, a wide variety of sample characteristics can be encountered and challenges may arise due to excessive solids, color, or turbidity. The aim of this study was to investigate the impacts of different sample preparation methods on CLPP performed on a variety of aqueous samples covering a broad range of physical and chemical characteristics. The results show that using filter paper, centrifugation, or settling helped clarify samples for subsequent CLPP analysis, however did not do so as effectively as dilution for the darkest samples. Dilution was able to provide suitable clarity for the darkest samples; however, 100-fold dilution significantly affected the carbon source utilization patterns (CSUPs), particularly with samples that were already partially or fully clear. Ten-fold dilution also had some effect on the CSUPs of samples which were originally clear; however, the effect was minimal. Based on these findings, for this specific set of samples, a 10-fold dilution provided a good balance between ease of use, sufficient clarity (for dark samples), and limited effect on CSUPs. The process and findings outlined here can hopefully serve future studies looking to utilize CLPP for functional analysis of microbial communities and also assist in comparing data from studies where different sample preparation methods were utilized.

Earth Entry Vehicle Design for Sample Return Missions Using M-SAPE

NASA Technical Reports Server (NTRS)

Samareh, Jamshid

2015-01-01

Most mission concepts that return sample material to Earth share one common element: an Earth entry vehicle (EEV). The primary focus of this paper is the examination of EEV design space for relevant sample return missions. Mission requirements for EEV concepts can be divided into three major groups: entry conditions (e.g., velocity and flight path angle), payload (e.g., mass, volume, and g-load limit), and vehicle characteristics (e.g., thermal protection system, structural topology, and landing concepts). The impacts of these requirements on the EEV design have been studied with an integrated system analysis tool, and the results will be discussed in details. In addition, through sensitivities analyses, critical design drivers that have been identified will be reviewed.

Leaching behaviour of bottom ash from RDF high-temperature gasification plants

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

Gori, M., E-mail: manuela.gori@dicea.unifi.it; Pifferi, L.; Sirini, P.

2011-07-15

This study investigated the physical properties, the chemical composition and the leaching behaviour of two bottom ash (BA) samples from two different refuse derived fuel high-temperature gasification plants, as a function of particle size. The X-ray diffraction patterns showed that the materials contained large amounts of glass. This aspect was also confirmed by the results of availability and ANC leaching tests. Chemical composition indicated that Fe, Mn, Cu and Cr were the most abundant metals, with a slight enrichment in the finest fractions. Suitability of samples for inert waste landfilling and reuse was evaluated through the leaching test EN 12457-2.more » In one sample the concentration of all metals was below the limit set by law, while limits were exceeded for Cu, Cr and Ni in the other sample, where the finest fraction showed to give the main contribution to leaching of Cu and Ni. Preliminary results of physical and geotechnical characterisation indicated the suitability of vitrified BA for reuse in the field of civil engineering. The possible application of a size separation pre-treatment in order to improve the chemical characteristics of the materials was also discussed.« less

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

PubMed

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

2014-01-01

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

Mercury concentrations in snapping turtles (Chelydra serpentina) correlate with environmental and landscape characteristics.

PubMed

Turnquist, Madeline A; Driscoll, Charles T; Schulz, Kimberly L; Schlaepfer, Martin A

2011-10-01

Mercury (Hg) deposited onto the landscape can be transformed into methylmercury (MeHg), a neurotoxin that bioaccumulates up the aquatic food chain. Here, we report on Hg concentrations in snapping turtles (Chelydra serpentina) across New York State, USA. The objectives of this study were to: (1) test which landscape, water, and biometric characteristics correlate with total Hg (THg) concentrations in snapping turtles; and (2) determine whether soft tissue THg concentrations correlate with scute (shell) concentrations. Forty-eight turtles were sampled non-lethally from ten lakes and wetlands across New York to observe patterns under a range of ecosystem variables and water chemistry conditions. THg concentrations ranged from 0.041 to 1.50 μg/g and 0.47 to 7.43 μg/g wet weight of muscle tissue and shell, respectively. The vast majority of mercury (~94%) was in the MeHg form. Sixty-one percent of turtle muscle samples exceeded U.S. Environmental Protection Agency (U.S. EPA) consumption advisory limit of 0.3 μg Hg/g for fish. Muscle THg concentrations were significantly correlated with sulfate in water and the maximum elevation of the watershed. Shell THg concentrations were significantly correlated with the acid neutralizing capacity (ANC) of water, the maximum elevation of the watershed, the percent open water in the watershed, the lake to watershed size, and various forms of atmospheric Hg deposition. Thus, our results demonstrate that THg concentrations in snapping turtles are spatially variable, frequently exceed advisory limits, and are significantly correlated with several landscape and water characteristics.

[Quantitative analysis of Cu in water by collinear DP-LIBS].

PubMed

Zheng, Mei-Lan; Yao, Ming-Yin; Chen, Tian-Bing; Lin, Yong-Zeng; Li, Wen-Bing; Liu, Mu-Hua

2014-07-01

The purpose of this research is to study the influence of double pulse laser induced breakdown spectroscopy (DP-LIBS) on the sensitivity of Cu in water. The water solution of Cu was tested by collinear DP-LIBS in this article. The results show that spectral intensity of Cu can be enhanced obviously by DP-LIBS, compared with single pulse laser induced breakdown spectroscopy (SP-LIBS). Besides, the experimental results were significantly impacted by delay time between laser pulse and spectrometer acquisition, delay time of double laser pulse and energy of laser pulse and so on. The paper determined the best conditions for DP-LIBS detecting Cu in water. The optimal acquisition delay time was 1 380 ns. The best laser pulse delay time was 25 ns. The most appropriate energy of double laser pulse was 100 mJ. Characteristic analysis of spectra of Cu at 324.7 and 327.4 nm was done for quantitative analysis. The detection limit was 3.5 microg x mL(-1) at 324.7 nm, and the detection limit was 4.84 microg x mL(-1) at 327.4 nm. The relative standard deviation of the two characteristic spectral lines was within 10%. The calibration curve of characteristic spectral line, established by 327.4 nm, was verified with 500 microg x mL(-1) sample. Concentration of the sample was 446 microg x mL(-1) calculated by the calibration curve. This research shows that the detection sensitivity of Cu in water can be improved by DP-LIBS. At the same time, it had high stability.

Systematic review of the use of online questionnaires of older adults.

PubMed

Remillard, Meegan L; Mazor, Kathleen M; Cutrona, Sarah L; Gurwitz, Jerry H; Tjia, Jennifer

2014-04-01

To describe methodological approaches to population targeting and sampling and to summarize limitations of Internet-based questionnaires in older adults. Systematic literature review. Studies using online questionnaires in older adult populations. English-language articles using search terms for geriatric, age 65 and over, Internet survey, online survey, Internet questionnaire, and online questionnaire in PubMed and EBSCO host between 1984 and July 2012. Inclusion criteria were study population mean age 65 and older and use of an online questionnaire for research. Review of 336 abstracts yielded 14 articles for full review by two investigators; 11 articles met inclusion criteria. Articles were extracted for study design and setting, participant characteristics, recruitment strategy, country, and study limitations. Eleven articles were published after 2001. Studies had populations with a mean age of 65 to 78, included descriptive and analytical designs, and were conducted in the United States, Australia, and Japan. Recruiting methods varied widely from paper fliers and personal e-mails to use of consumer marketing panels. Investigator-reported study limitations included the use of small convenience samples and limited generalizability. Online questionnaires are a feasible method of surveying older adults in some geographic regions and for some subsets of older adults, but limited Internet access constrains recruiting methods and often limits study generalizability. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Health related quality of life in patients with neuroendocrine tumors compared with the general Norwegian population.

PubMed

Haugland, Trude; Vatn, Morten H; Veenstra, Marijke; Wahl, Astrid Klopstad; Natvig, Gerd Karin

2009-08-01

Health related quality of life (HRQoL) was characterized among patients with neuroendocrine tumor (NET) and compared with the general Norwegian population. A cross sectional, comparative design was chosen, and the samples comprised 196 NET patients and 5,258 individuals from the general Norwegian population. We used Chi-square cross tab calculations to evaluate sociodemographic characteristics, T-tests for independent samples and Analysis of Variance (ANOVA) in order to compare HRQoL (SF-36) scores across a range of background variables. Furthermore, T-tests were used to analyze differences in HRQoL scores between the samples. NET patients demonstrated significantly lower on all HRQoL subscales when compared with the general population with the lowest values on general health, physical limitation and vitality. Individuals above 70 years reported lower scores on physical functioning and physical limitations compared with those who were younger. Individuals with higher levels of education reported increased physical functioning compared with those with less education and full-time or part-time workers described higher physical functioning and less physical limitations compared with those who were retired. All SF-36 HRQoL scores were significantly lower among the NET patients when compared with the general population. Assistance from health personnel to NET patients should focus on those domains.

Micrometeoroid and Orbital Debris Threat Assessment: Mars Sample Return Earth Entry Vehicle

NASA Technical Reports Server (NTRS)

Christiansen, Eric L.; Hyde, James L.; Bjorkman, Michael D.; Hoffman, Kevin D.; Lear, Dana M.; Prior, Thomas G.

2011-01-01

This report provides results of a Micrometeoroid and Orbital Debris (MMOD) risk assessment of the Mars Sample Return Earth Entry Vehicle (MSR EEV). The assessment was performed using standard risk assessment methodology illustrated in Figure 1-1. Central to the process is the Bumper risk assessment code (Figure 1-2), which calculates the critical penetration risk based on geometry, shielding configurations and flight parameters. The assessment process begins by building a finite element model (FEM) of the spacecraft, which defines the size and shape of the spacecraft as well as the locations of the various shielding configurations. This model is built using the NX I-deas software package from Siemens PLM Software. The FEM is constructed using triangular and quadrilateral elements that define the outer shell of the spacecraft. Bumper-II uses the model file to determine the geometry of the spacecraft for the analysis. The next step of the process is to identify the ballistic limit characteristics for the various shield types. These ballistic limits define the critical size particle that will penetrate a shield at a given impact angle and impact velocity. When the finite element model is built, each individual element is assigned a property identifier (PID) to act as an index for its shielding properties. Using the ballistic limit equations (BLEs) built into the Bumper-II code, the shield characteristics are defined for each and every PID in the model. The final stage of the analysis is to determine the probability of no penetration (PNP) on the spacecraft. This is done using the micrometeoroid and orbital debris environment definitions that are built into the Bumper-II code. These engineering models take into account orbit inclination, altitude, attitude and analysis date in order to predict an impacting particle flux on the spacecraft. Using the geometry and shielding characteristics previously defined for the spacecraft and combining that information with the environment model calculations, the Bumper-II code calculates a probability of no penetration for the spacecraft.

Validation of a near infrared microscopy method for the detection of animal products in feedingstuffs: results of a collaborative study.

PubMed

Boix, A; Fernández Pierna, J A; von Holst, C; Baeten, V

2012-01-01

The performance characteristics of a near infrared microscopy (NIRM) method, when applied to the detection of animal products in feedingstuffs, were determined via a collaborative study. The method delivers qualitative results in terms of the presence or absence of animal particles in feed and differentiates animal from vegetable feed ingredients on the basis of the evaluation of near infrared spectra obtained from individual particles present in the sample. The specificity ranged from 86% to 100%. The limit of detection obtained on the analysis of the sediment fraction, prepared as for the European official method, was 0.1% processed animal proteins (PAPs) in feed, since all laboratories correctly identified the positive samples. This limit has to be increased up to 2% for the analysis of samples which are not sedimented. The required sensitivity for the official control is therefore achieved in the analysis of the sediment fraction of the samples where the method can be applied for the detection of the presence of animal meal. Criteria for the classification of samples, when fewer than five spectra are found, as being of animal origin needs to be set up in order to harmonise the approach taken by the laboratories when applying NIRM for the detection of the presence of animal meal in feed.

Classification of prostate cancer grade using temporal ultrasound: in vivo feasibility study

NASA Astrophysics Data System (ADS)

Ghavidel, Sahar; Imani, Farhad; Khallaghi, Siavash; Gibson, Eli; Khojaste, Amir; Gaed, Mena; Moussa, Madeleine; Gomez, Jose A.; Siemens, D. Robert; Leveridge, Michael; Chang, Silvia; Fenster, Aaron; Ward, Aaron D.; Abolmaesumi, Purang; Mousavi, Parvin

2016-03-01

Temporal ultrasound has been shown to have high classification accuracy in differentiating cancer from benign tissue. In this paper, we extend the temporal ultrasound method to classify lower grade Prostate Cancer (PCa) from all other grades. We use a group of nine patients with mostly lower grade PCa, where cancerous regions are also limited. A critical challenge is to train a classifier with limited aggressive cancerous tissue compared to low grade cancerous tissue. To resolve the problem of imbalanced data, we use Synthetic Minority Oversampling Technique (SMOTE) to generate synthetic samples for the minority class. We calculate spectral features of temporal ultrasound data and perform feature selection using Random Forests. In leave-one-patient-out cross-validation strategy, an area under receiver operating characteristic curve (AUC) of 0.74 is achieved with overall sensitivity and specificity of 70%. Using an unsupervised learning approach prior to proposed method improves sensitivity and AUC to 80% and 0.79. This work represents promising results to classify lower and higher grade PCa with limited cancerous training samples, using temporal ultrasound.

Energy dependence of the band-limited noise in black hole X-ray binaries★

NASA Astrophysics Data System (ADS)

Stiele, H.; Yu, W.

2015-10-01

Black hole low-mass X-ray binaries show a variety of variability features, which manifest as narrow peak-like structures superposed on broad noise components in power density spectra in the hard X-ray emission. In this work, we study variability properties of the band-limited noise component during the low-hard state for a sample of black hole X-ray binaries. We investigate the characteristic frequency and amplitude of the band-limited noise component and study covariance spectra. For observations that show a noise component with a characteristic frequency above 1 Hz in the hard energy band (4-8 keV), we found this very same component at a lower frequency in the soft band (1-2 keV). This difference in characteristic frequency is an indication that while both the soft and the hard band photons contribute to the same band-limited noise component, which likely represents the modulation of the mass accretion rate, the origin of the soft photons is actually further away from the black hole than the hard photons. Thus, the soft photons are characterized by larger radii, lower frequencies and softer energies, and are probably associated with a smaller optical depth for Comptonization up-scattering from the outer layer of the corona, or suggest a temperature gradient of the corona. We interpret this energy dependence within the picture of energy-dependent power density states as a hint that the contribution of the up-scattered photons originating in the outskirts of the Comptonizing corona to the overall emission in the soft band is becoming significant.

Sediment Characteristics and Transport in the Kootenai River White Sturgeon Critical Habitat near Bonners Ferry, Idaho

USGS Publications Warehouse

Fosness, Ryan L.; Williams, Marshall L.

2009-01-01

Recovery efforts for the endangered Kootenai River population of white sturgeon require an understanding of the characteristics and transport of suspended and bedload sediment in the critical habitat reach of the river. In 2007 and 2008, the U.S. Geological Survey in cooperation with the Kootenai Tribe of Idaho, conducted suspended- and bedload-sediment sampling in the federally designated critical habitat of the endangered Kootenai River white sturgeon population. Three sediment-sampling sites were selected that represent the hydraulic differences in the critical habitat. Suspended- and bedload-sediment samples along with acoustic Doppler current profiles were collected at these sites during specific river discharges. Samples were analyzed to determine suspended- and bedload-sediment characteristics and transport rates. Sediment transport data were analyzed to provide total loading estimates for suspended and bedload sediment in the critical habitat reach. Total suspended-sediment discharge primarily occurred as fine material that moved through the system in suspension. Total suspended-sediment discharge ranged from about 300 metric tons per day to more than 23,000 metric tons per day. Total suspended sediment remained nearly equal throughout the critical habitat, with the exception of a few cases where mass wasting of the banks may have caused sporadic spikes in total suspended sediment. Bedload-sediment discharge averaged 0-3 percent of the total loading. These bedload discharges ranged from 0 to 271 tons per day. The bedload discharge in the upper part of the critical habitat primarily consisted of fine to coarse gravel. A decrease in river competence in addition to an armored channel may be the cause of this limited bedload discharge. The bedload discharge in the middle part of the white sturgeon critical habitat varied greatly, depending on the extent of the backwater from Kootenay Lake. A large quantity of fine-to-coarse gravel is present in the braided reach, but the duration of transport for these gravels is limited by the encroaching backwater of Kootenay Lake. Bedload discharge in the lower part of the white sturgeon critical habitat primarily consisted of fine to coarse sand due to decreased velocities as a result of the backwater from Kootenay Lake.

Absorbance characteristics of a liquid-phase gas sensor based on gas-permeable liquid core waveguides.

PubMed

Peng, Pei; Wang, Wei; Zhang, Li; Su, Shiguang; Wang, Jiahui

2013-12-04

The absorbance characteristics and influential factors on these characteristics for a liquid-phase gas sensor, which is based on gas-permeable liquid core waveguides (LCWs), are studied from theoretical and experimental viewpoints in this paper. According to theory, it is predicted that absorbance is proportional to the analyte concentration, sampling time, analyte diffusion coefficient, and geometric factor of this device when the depletion layer of the analyte is ignored. The experimental results are in agreement with the theoretical hypothesis. According to the experimental results, absorbance is time-dependent and increasing linearly over time after the requisite response time with a linear correlation coefficient r(2)>0.999. In the linear region, the rate of absorbance change (RAC) indicates improved linearity with sample concentration and a relative higher sensitivity than instantaneous absorbance does. By using a core liquid that is more affinitive to the analyte, reducing wall thickness and the inner diameter of the tubing, or increasing sample flow rate limitedly, the response time can be decreased and the sensitivity can be increased. However, increasing the LCW length can only enhance sensitivity and has no effect on response time. For liquid phase detection, there is a maximum flow rate, and the absorbance will decrease beyond the stated limit. Under experimental conditions, hexane as the LCW core solvent, a tubing wall thickness of 0.1 mm, a length of 10 cm, and a flow rate of 12 mL min(-1), the detection results for the aqueous benzene sample demonstrate a response time of 4 min. Additionally, the standard curve for the RAC versus concentration is RAC=0.0267c+0.0351 (AU min(-1)), with r(2)=0.9922 within concentrations of 0.5-3.0 mg L(-1). The relative error for 0.5 mg L(-1) benzene (n=6) is 7.4±3.7%, and the LOD is 0.04 mg L(-1). This research can provide theoretical and practical guides for liquid-phase gas sensor design and development based on a gas-permeable Teflon AF 2400 LCW. Copyright © 2013 Elsevier B.V. All rights reserved.

Pediatric sample inclusion in an opt-out biorepository linking DNA to de-identified medical records: Pediatric BioVU

PubMed Central

McGregor, Tracy L.; Van Driest, Sara L.; Brothers, Kyle B.; Bowton, Erica A.; Muglia, Louis J.; Roden, Dan M.

2013-01-01

The Vanderbilt DNA repository, BioVU, links DNA from leftover clinical blood samples to de-identified electronic medical records. After initiating adult sample collection, pediatric extension required consideration of ethical concerns specific to pediatrics and implementation of specialized DNA extraction methods. In the first year of pediatric sample collection, over 11,000 samples were included from individuals younger than 18 years. We compared the pediatric BioVU cohort to the overall Vanderbilt University Medical Center pediatric population and found similar demographic characteristics; however, the BioVU cohort has higher rates of select diseases, medication exposures, and laboratory testing, demonstrating enriched representation of severe or chronic disease. This unbalanced sample accumulation may accelerate research of some cohorts, but also may limit study of relatively benign conditions and the accrual of unaffected and unbiased control samples. BioVU represents a feasible model for pediatric DNA biobanking but involves both ethical and practical considerations specific to the pediatric population. PMID:23281421

Bioavailability, ecotoxicity, and geological characteristics of trace lead in sediments from two sites on Negro River, Uruguay, South America.

PubMed

Míguez, Diana M; Huertas, Raquel; Carrara, María V; Carnikián, Agustín; Bouvier, María E; Martínez, María J; Keel, Karen; Pioda, Carolina; Darré, Elena; Pérez, Ramiro; Viera, Santiago; Massa, Enrique

2012-04-01

Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation. Data showed that Baygorria's sediments have greater percentage of clay than Bonete's (20.4 and 5.8%, respectively). Lead was measurable in Baygorria's sediments, meanwhile in Bonete's, it was always below the detection limit. In water samples, lead was below detection limit at both sites. Bioassays using sub-lethal growth and survival test with Hyalella curvispina amphipod, screening with bioluminescent bacteria Photobacterium leiognathi, and acute toxicity bioassay with Pimephales promelas fish indicated toxicity at Baygorria, with much less effect at Bonete. Even though no lethal effects could be demonstrated, higher sub-lethal toxicity was found in samples from Baygorria site, showing a possible concentration of the contaminant in the clay fraction.

Psychiatric characteristics of homicide defendants.

PubMed

Martone, Christine A; Mulvey, Edward P; Yang, Suzanne; Nemoianu, Andrei; Shugarman, Ryan; Soliman, Layla

2013-09-01

The authors examined the rate of mental disorders in an unselected sample of homicide defendants in a U.S. jurisdiction, seeking to identify psychiatric factors associated with offense characteristics and court outcomes. Defendants charged with homicide in a U.S. urban county between 2001 and 2005 received a psychiatric evaluation after arrest. Demographic, historical, and psychiatric variables as well as offense characteristics and legal outcomes were described. Bivariate analyses examined differences by age group and by race, and logistic models examined predictors of multiple victims, firearm use, guilty plea, and guilty verdict. Fifty-eight percent of the sample had at least one axis I or II diagnosis, most often a substance use disorder (47%). Axis I or II diagnoses were more common (78%) among defendants over age 40. Although 37% of the sample had prior psychiatric treatment, only 8% of the defendants with diagnosed axis I disorders had outpatient treatment during the 3 months preceding the homicide; African Americans were less likely than non-African Americans to be in treatment. African American males were more likely to use a firearm and to have a male victim. In exploratory analyses, psychiatric factors did not predict multiple victims, firearm use in the crime, or a guilty verdict. Rates of axis I disorders were lower than reported in previous studies. Few homicide defendants were in psychiatric treatment at the time of the crime, suggesting limited opportunities for prevention by mental health providers.

Aroma characterization of tangerine hybrids by gas-chromatography-olfactometry and sensory evaluation.

PubMed

Miyazaki, Takayuki; Plotto, Anne; Baldwin, Elizabeth A; Reyes-De-Corcuera, José I; Gmitter, Fred G

2012-03-15

Tangerines have a distinct flavor among citrus fruit. However, information on tangerine volatiles remains limited. Volatile compounds from a breeding population of tangerines were earlier identified by gas chromatography-mass spectrometry. In this study, five hybrids with a distinct volatile profile were analyzed by gas-chromatography-olfactometry (GC-O) and descriptive sensory analysis. Forty-nine aroma active compounds were found in a consensus by GC-O. Aldehydes were the most important group with odor activity, as well as monoterpenes, esters, alcohols and ketones. 1,8-Cineole, β-myrcene, (E,E)-2,4-nonadienal, hexanal, ethyl-2-methylbutanoate, and linalool were perceived with high intensity in most samples. Two 'Clementine' × 'Minneola' and one 'Fortune' × 'Murcott' hybrids with tangerine, sulfury and woody/spicy flavors had aroma active compounds with terpeney, fatty/vegetable and metallic/rubber descriptors. A tangerine with 'Valencia' orange in its parentage had a characteristic orange flavor, which could be explained by esters and ketones, high in fruity and floral odor intensities. A hybrid of unknown origin had a distinct fruity-non-citrus and pumpkin/fatty flavor; that sample had the lowest amount of aroma-active volatiles, with the least compounds with terpeney odors. There was no one compound characteristic of tangerine flavor. Nevertheless, each sample sensory characteristic could be explained by a set of aroma-active volatile compounds.

Identification of PM10 characteristics involved in cellular responses in human bronchial epithelial cells (Beas-2B).

PubMed

Van Den Heuvel, Rosette; Den Hond, Elly; Govarts, Eva; Colles, Ann; Koppen, Gudrun; Staelens, Jeroen; Mampaey, Maja; Janssen, Nicole; Schoeters, Greet

2016-08-01

Notwithstanding evidence is present that physicochemical characteristics of ambient particles attribute to adverse health effects, there is still some lack of understanding in this complex relationship. At this moment it is not clear which properties (such as particle size, chemical composition) or sources of the particles are most relevant for health effects. This study investigates the in vitro toxicity of PM10 in relation to PM chemical composition, black carbon (BC), endotoxin content and oxidative potential (OP). In 2013-2014 PM10 was sampled (24h sampling, 108 sampling days) in ambient air at three sites in Flanders (Belgium) with different pollution characteristics: an urban traffic site (Borgerhout), an industrial area (Zelzate) and a rural background location (Houtem). To characterize the toxic potential of PM10, airway epithelial cells (Beas-2B cells) have been exposed to particles in vitro. Different endpoints were studied including cell damage and death (cell viability) using the Neutral red Uptake assay, the production of pro-inflammatory molecules by interleukin 8 (IL-8) induction and DNA-damaging activity using the FPG-modified Comet assay. The endotoxin levels in the collected samples were analysed and the capacity of PM10 particles to produce reactive oxygen species (OP) was evaluated by electron paramagnetic resonance (EPR) spectroscopy. Chemical characteristics of PM10 (BC, As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) and meteorological conditions were recorded on the sampling days. PM10 particles exhibited dose-dependent cytotoxicity in Beas-2B cells and were found to significantly induce the release of IL-8 in samples from the three locations. Oxidatively damaged DNA was observed in exposed Beas-2B cells. Endotoxin levels above the detection limit were detected in half of the samples. OP was measurable in all samples. Associations between PM10 characteristics and biological effects of PM10 were assessed by single and multiple regression analyses. The reduction in cell viability was significantly correlated with BC, Cd and Pb. The induction of IL-8 in Beas-2B cells was significantly associated with Cu, Ni and Zn and endotoxin. Endotoxin levels explained 33% of the variance in IL-8 induction. A significant interaction between ambient temperature and endotoxin on the pro-inflammatory activity was seen. No association was found between OP and the cellular responses. This study supports the hypothesis that, on an equal mass basis, PM10 induced biological effects differ due to differences in PM10 characteristics. Metals (Cd, Cu, Ni and Zn), BC, and endotoxin were among the main determinants for the observed biological responses. Copyright © 2016 Elsevier Inc. All rights reserved.

Predictors of patient non-attendance at Improving Access to Psychological Therapy services demonstration sites

PubMed Central

Di Bona, Laura; Saxon, David; Barkham, Michael; Dent-Brown, Kim; Parry, Glenys

2014-01-01

Background Improving Access to Psychological Therapy (IAPT) services have increased the number of people with common mental health disorders receiving psychological therapy in England, but concerns remain about how equitably these services are accessed. Method Using cohort patient data (N=363) collected as part of the independent evaluation of the two demonstration sites, logistic regression was utilised to identify socio-demographic, clinical and service factors predictive of IAPT non-attendance. Results Significant predictors of IAPT first session non-attendance by patients were: lower non-risk score on the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM); more frequent thoughts of “being better off dead” (derived from the CORE-OM); either a very recent onset of common mental health disorder (1 month or less) or a long term condition (more than 2 years); and site. Limitations The small sample and low response rate are limitations, as the sample may not be representative of all those referred to IAPT services. The predictive power of the logistic regression model is limited and suggests other variables not available in the dataset may also be important predictors. Conclusions The clinical characteristics of risk to self, severity of emotional distress, and illness duration, along with site, were more predictive of IAPT non-attendance than socio-demographic characteristics. Further testing of the relationship between these variables and IAPT non-attendance is recommended. Clinicians should monitor IAPT uptake in those they refer and implement strategies to increase their engagement with services, particularly when referring people presenting with suicidal ideation or more chronic illness. PMID:25194784

Augmenting comprehension of geological relationships by integrating 3D laser scanned hand samples within a GIS environment

NASA Astrophysics Data System (ADS)

Harvey, A. S.; Fotopoulos, G.; Hall, B.; Amolins, K.

2017-06-01

Geological observations can be made on multiple scales, including micro- (e.g. thin section), meso- (e.g. hand-sized to outcrop) and macro- (e.g. outcrop and larger) scales. Types of meso-scale samples include, but are not limited to, rocks (including drill cores), minerals, and fossils. The spatial relationship among samples paired with physical (e.g. granulometric composition, density, roughness) and chemical (e.g. mineralogical and isotopic composition) properties can aid in interpreting geological settings, such as paleo-environmental and formational conditions as well as geomorphological history. Field samples are collected along traverses in the area of interest based on characteristic representativeness of a region, predetermined rate of sampling, and/or uniqueness. The location of a sample can provide relative context in seeking out additional key samples. Beyond labelling and recording of geospatial coordinates for samples, further analysis of physical and chemical properties may be conducted in the field and laboratory. The main motivation for this paper is to present a workflow for the digital preservation of samples (via 3D laser scanning) paired with the development of cyber infrastructure, which offers geoscientists and engineers the opportunity to access an increasingly diverse worldwide collection of digital Earth materials. This paper describes a Web-based graphical user interface developed using Web AppBuilder for ArcGIS for digitized meso-scale 3D scans of geological samples to be viewed alongside the macro-scale environment. Over 100 samples of virtual rocks, minerals and fossils populate the developed geological database and are linked explicitly with their associated attributes, characteristic properties, and location. Applications of this new Web-based geological visualization paradigm in the geosciences demonstrate the utility of such a tool in an age of increasing global data sharing.

Street characteristics preferred for transportation walking among older adults: a choice-based conjoint analysis with manipulated photographs.

PubMed

Van Cauwenberg, Jelle; De Bourdeaudhuij, Ilse; Clarys, Peter; Nasar, Jack; Salmon, Jo; Goubert, Liesbet; Deforche, Benedicte

2016-01-16

Knowledge about the relationships between micro-scale environmental factors and older adults' walking for transport is limited and inconsistent. This is probably due to methodological limitations, such as absence of an accurate neighborhood definition, lack of environmental heterogeneity, environmental co-variation, and recall bias. Furthermore, most previous studies are observational in nature. We aimed to address these limitations by investigating the effects of manipulating photographs on micro-scale environmental factors on the appeal of a street for older adults' transportation walking. Secondly, we used latent class analysis to examine whether subgroups could be identified that have different environmental preferences for transportation walking. Thirdly, we investigated whether these subgroups differed in socio-demographic, functional and psychosocial characteristics, current level of walking and environmental perceptions of their own street. Data were collected among 1131 Flemish older adults through an online (n = 940) or an interview version of the questionnaire (n = 191). This questionnaire included a choice-based conjoint exercise with manipulated photographs of a street. These manipulated photographs originated from one panoramic photograph of an existing street that was manipulated on nine environmental attributes. Participants chose which of two presented streets they would prefer to walk for transport. In the total sample, sidewalk evenness had by far the greatest appeal for transportation walking. The other environmental attributes were less important. Four subgroups that differed in their environmental preferences for transportation walking were identified. In the two largest subgroups (representing 86% of the sample) sidewalk evenness was the most important environmental attribute. In the two smaller subgroups (each comprising 7% of the sample), traffic volume and speed limit were the most important environmental attributes for one, and the presence of vegetation and a bench were the most important environmental attributes for the other. This latter subgroup included a higher percentage of service flat residents than the other subgroups. Our results suggest that the provision of even sidewalks should be considered a priority when developing environmental interventions aiming to stimulate older adults' transportation walking. Natural experiments are needed to confirm whether our findings can be translated to real environments and actual transportation walking behavior.

Investigation on the behavioral difference in third order nonlinearity and optical limiting of Mn0.55Cu0.45Fe2O4 nanoparticles annealed at different temperatures

NASA Astrophysics Data System (ADS)

Yuvaraj, S.; Manikandan, N.; Vinitha, G.

2017-11-01

Mn0.55Cu0.45Fe2O4 nanoparticles were synthesized by wet chemical co-precipitation method. The obtained samples were annealed at different temperatures (500 °C to 1250 °C). All annealed samples were characterized for their structural, magnetic, linear and non-linear optical properties. XRD results confirm single phase cubic spinel structure only for samples annealed at 800 °C and 1250 °C. The average crystallite sizes of the samples are in the range of 11-37 nm. HR-SEM image of the sample annealed at 800 °C exposed spherical morphology. The quantitative analysis of EDX results is close to the expected values. Bandgaps were evaluated from UV-DRS. The FTIR spectrum showing the essential peaks around 452.1 and 567.2 cm-1 prove the formation of spinel nanoparticles. In PL spectrum, a broad emission peak is attained in visible region at 485 nm. The saturation magnetization (M s), coercivity (H c) and remanence magnetization (M r) are obtained from the hysteresis curve. Nonlinear absorption coefficients (10-4 cm W-1), nonlinear indices of refraction (10-8 cm2 W-1) and the third order nonlinear susceptibilities (10-6 esu) are determined using Z-scan experiment. CW laser beam is utilized to study the optical limiting characteristics and the results prove these materials to be a potential candidate for device applications like optical switches and power limiters.

Digital Holographic Microscopy, a Method for Detection of Microorganisms in Plume Samples from Enceladus and Other Icy Worlds

PubMed Central

Bedrossian, Manuel; Lindensmith, Chris

2017-01-01

Abstract Detection of extant microbial life on Earth and elsewhere in the Solar System requires the ability to identify and enumerate micrometer-scale, essentially featureless cells. On Earth, bacteria are usually enumerated by culture plating or epifluorescence microscopy. Culture plates require long incubation times and can only count culturable strains, and epifluorescence microscopy requires extensive staining and concentration of the sample and instrumentation that is not readily miniaturized for space. Digital holographic microscopy (DHM) represents an alternative technique with no moving parts and higher throughput than traditional microscopy, making it potentially useful in space for detection of extant microorganisms provided that sufficient numbers of cells can be collected. Because sample collection is expected to be the limiting factor for space missions, especially to outer planets, it is important to quantify the limits of detection of any proposed technique for extant life detection. Here we use both laboratory and field samples to measure the limits of detection of an off-axis digital holographic microscope (DHM). A statistical model is used to estimate any instrument's probability of detection at various bacterial concentrations based on the optical performance characteristics of the instrument, as well as estimate the confidence interval of detection. This statistical model agrees well with the limit of detection of 103 cells/mL that was found experimentally with laboratory samples. In environmental samples, active cells were immediately evident at concentrations of 104 cells/mL. Published estimates of cell densities for Enceladus plumes yield up to 104 cells/mL, which are well within the off-axis DHM's limits of detection to confidence intervals greater than or equal to 95%, assuming sufficient sample volumes can be collected. The quantitative phase imaging provided by DHM allowed minerals to be distinguished from cells. Off-axis DHM's ability for rapid low-level bacterial detection and counting shows its viability as a technique for detection of extant microbial life provided that the cells can be captured intact and delivered to the sample chamber in a sufficient volume of liquid for imaging. Key Words: In situ life detection—Extant microorganisms—Holographic microscopy—Ocean Worlds—Enceladus—Imaging. Astrobiology 17, 913–925. PMID:28708412

Energy-dispersive X-ray fluorescence systems as analytical tool for assessment of contaminated soils.

PubMed

Vanhoof, Chris; Corthouts, Valère; Tirez, Kristof

2004-04-01

To determine the heavy metal content in soil samples at contaminated locations, a static and time consuming procedure is used in most cases. Soil samples are collected and analyzed in the laboratory at high quality and high analytical costs. The demand by government and consultants for a more dynamic approach and by customers requiring performances in which analyses are performed in the field with immediate feedback of the analytical results, is growing. Especially during the follow-up of remediation projects or during the determination of the sampling strategy, field analyses are advisable. For this purpose four types of ED-XRF systems, ranging from portable up to high performance laboratory systems, have been evaluated. The evaluation criteria are based on the performance characteristics for all the ED-XRF systems such as limit of detection, accuracy and the measurement uncertainty on one hand, and also the influence of the sample pretreatment on the obtained results on the other hand. The study proved that the field portable system and the bench top system, placed in a mobile van, can be applied as field techniques, resulting in semi-quantitative analytical results. A limited homogenization of the analyzed sample significantly increases the representativeness of the soil sample. The ED-XRF systems can be differentiated by their limits of detection which are a factor of 10 to 20 higher for the portable system. The accuracy of the results and the measurement uncertainty also improved using the bench top system. Therefore, the selection criteria for applicability of both field systems are based on the required detection level and also the required accuracy of the results.

Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting.

PubMed

Rashed-Ul Islam, S M; Jahan, Munira; Tabassum, Shahina

2015-01-01

Virological monitoring is the best predictor for the management of chronic hepatitis B virus (HBV) infections. Consequently, it is important to use the most efficient, rapid and cost-effective testing systems for HBV DNA quantification. The present study compared the performance characteristics of a one-step HBV polymerase chain reaction (PCR) vs the two-step HBV PCR method for quantification of HBV DNA from clinical samples. A total of 100 samples consisting of 85 randomly selected samples from patients with chronic hepatitis B (CHB) and 15 samples from apparently healthy individuals were enrolled in this study. Of the 85 CHB clinical samples tested, HBV DNA was detected from 81% samples by one-step PCR method with median HBV DNA viral load (VL) of 7.50 × 10 3 lU/ml. In contrast, 72% samples were detected by the two-step PCR system with median HBV DNA of 3.71 × 10 3 lU/ml. The one-step method showed strong linear correlation with two-step PCR method (r = 0.89; p < 0.0001). Both methods showed good agreement at Bland-Altman plot, with a mean difference of 0.61 log 10 IU/ml and limits of agreement of -1.82 to 3.03 log 10 IU/ml. The intra-assay and interassay coefficients of variation (CV%) of plasma samples (4-7 log 10 IU/ml) for the one-step PCR method ranged between 0.33 to 0.59 and 0.28 to 0.48 respectively, thus demonstrating a high level of concordance between the two methods. Moreover, elimination of the DNA extraction step in the one-step PCR kit allowed time-efficient and significant labor and cost savings for the quantification of HBV DNA in a resource limited setting. Rashed-Ul Islam SM, Jahan M, Tabassum S. Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting. Euroasian J Hepato-Gastroenterol 2015;5(1):11-15.

Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting

PubMed Central

Jahan, Munira; Tabassum, Shahina

2015-01-01

Virological monitoring is the best predictor for the management of chronic hepatitis B virus (HBV) infections. Consequently, it is important to use the most efficient, rapid and cost-effective testing systems for HBV DNA quantification. The present study compared the performance characteristics of a one-step HBV polymerase chain reaction (PCR) vs the two-step HBV PCR method for quantification of HBV DNA from clinical samples. A total of 100 samples consisting of 85 randomly selected samples from patients with chronic hepatitis B (CHB) and 15 samples from apparently healthy individuals were enrolled in this study. Of the 85 CHB clinical samples tested, HBV DNA was detected from 81% samples by one-step PCR method with median HBV DNA viral load (VL) of 7.50 × 103 lU/ml. In contrast, 72% samples were detected by the two-step PCR system with median HBV DNA of 3.71 × 103 lU/ml. The one-step method showed strong linear correlation with two-step PCR method (r = 0.89; p < 0.0001). Both methods showed good agreement at Bland-Altman plot, with a mean difference of 0.61 log10 IU/ml and limits of agreement of -1.82 to 3.03 log10 IU/ml. The intra-assay and interassay coefficients of variation (CV%) of plasma samples (4-7 log10 IU/ml) for the one-step PCR method ranged between 0.33 to 0.59 and 0.28 to 0.48 respectively, thus demonstrating a high level of concordance between the two methods. Moreover, elimination of the DNA extraction step in the one-step PCR kit allowed time-efficient and significant labor and cost savings for the quantification of HBV DNA in a resource limited setting. How to cite this article Rashed-Ul Islam SM, Jahan M, Tabassum S. Evaluation of a Rapid One-step Real-time PCR Method as a High-throughput Screening for Quantification of Hepatitis B Virus DNA in a Resource-limited Setting. Euroasian J Hepato-Gastroenterol 2015;5(1):11-15. PMID:29201678

Surface terrain characteristics and monsoon season mass balance of debris-covered glaciers in the Khumbu Himal, Nepal, obtained from high resolution Pléiades imagery.

NASA Astrophysics Data System (ADS)

Klug, Christoph; Nicholson, Lindsey; Rieg, Lorenzo; Sailer, Rudolf; Wirbel, Anna

2016-04-01

Debris-covered glaciers in the eastern Himalaya have pronounced surface relief consisting of hummocks and hollows, ice cliffs, lakes and former lake beds. This relief and spatially variable surface properties are expected to influence the spatially distributed surface energy balance and related ice mass loss and atmospheric interactions, but only a few studies have so far explicitly examined the nature of the surface terrain and its textures . In this work we present a new high-resolution digital terrain model (DTM) of a portion of the Khumbu Himal in the eastern Nepalese Himalaya, derived from Pléiades satellite imagery sampled in spring 2015. We use this DTM to study the terrain characteristics of five sample glaciers and analyse the inter- and intra- glacier variability of terrain characteristics in the context of glacier flow velocities and surface changes presented in previous studies in the area. In parallel to this analysis we also present the seasonal geodetic mass balance between spring and fall 2015, and relate it to the terrain properties, surface velocity and limited knowledge of the local lapse rates in meteorological conditions during this monsoon season.

Relationship Between Energy Drink Consumption and Nutrition Knowledge in Student-Athletes.

PubMed

Hardy, Richard; Kliemann, Nathalie; Evansen, Taylor; Brand, Jefferson

2017-01-01

To identify the relationships between energy drink consumption, nutrition knowledge, and socio-demographic characteristics in a convenience sample of student-athletes. Cross-sectional. Online survey. A total of 194 student-athletes (112 female and 82 male). Socio-demographic characteristics, knowledge of human nutrition, energy drink consumption habits. Chi-square tests of independence, independent t tests, and hierarchical regression analyses were applied. Most student-athletes in the sample (85.5%) did not consume energy drinks, but those who did tended to be male (P = .004), had lower overall knowledge of nutrition (P = .02), and had a lower grade point average (P < .001) than did nonusers. Also, energy drink consumption was associated with the overall nutrition knowledge score when adjusted for socio-demographic characteristics, with nonusers having greater nutrition knowledge (P = .007) than users. Student-athletes tend to refrain from energy drink use but those who use it have a tendency to have lower nutrition knowledge than do nonusers. Therefore, nutrition education targeted toward student-athletes should encompass the consumption of energy drinks because limited evidence shows the benefits of collegiate athletes consuming energy drinks. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Effect of framework design on crown failure.

PubMed

Bonfante, Estevam A; da Silva, Nelson R F A; Coelho, Paulo G; Bayardo-González, Daniel E; Thompson, Van P; Bonfante, Gerson

2009-04-01

This study evaluated the effect of core-design modification on the characteristic strength and failure modes of glass-infiltrated alumina (In-Ceram) (ICA) compared with porcelain fused to metal (PFM). Premolar crowns of a standard design (PFMs and ICAs) or with a modified framework design (PFMm and ICAm) were fabricated, cemented on dies, and loaded until failure. The crowns were loaded at 0.5 mm min(-1) using a 6.25 mm tungsten-carbide ball at the central fossa. Fracture load values were recorded and fracture analysis of representative samples were evaluated using scanning electron microscopy. Probability Weibull curves with two-sided 90% confidence limits were calculated for each group and a contour plot of the characteristic strength was obtained. Design modification showed an increase in the characteristic strength of the PFMm and ICAm groups, with PFM groups showing higher characteristic strength than ICA groups. The PFMm group showed the highest characteristic strength among all groups. Fracture modes of PFMs and of PFMm frequently reached the core interface at the lingual cusp, whereas ICA exhibited bulk fracture through the alumina core. Core-design modification significantly improved the characteristic strength for PFM and for ICA. The PFM groups demonstrated higher characteristic strength than both ICA groups combined.

Research Designs for Intervention Research with Small Samples II: Stepped Wedge and Interrupted Time-Series Designs.

PubMed

Fok, Carlotta Ching Ting; Henry, David; Allen, James

2015-10-01

The stepped wedge design (SWD) and the interrupted time-series design (ITSD) are two alternative research designs that maximize efficiency and statistical power with small samples when contrasted to the operating characteristics of conventional randomized controlled trials (RCT). This paper provides an overview and introduction to previous work with these designs and compares and contrasts them with the dynamic wait-list design (DWLD) and the regression point displacement design (RPDD), which were presented in a previous article (Wyman, Henry, Knoblauch, and Brown, Prevention Science. 2015) in this special section. The SWD and the DWLD are similar in that both are intervention implementation roll-out designs. We discuss similarities and differences between the SWD and DWLD in their historical origin and application, along with differences in the statistical modeling of each design. Next, we describe the main design characteristics of the ITSD, along with some of its strengths and limitations. We provide a critical comparative review of strengths and weaknesses in application of the ITSD, SWD, DWLD, and RPDD as small sample alternatives to application of the RCT, concluding with a discussion of the types of contextual factors that influence selection of an optimal research design by prevention researchers working with small samples.

Research Designs for Intervention Research with Small Samples II: Stepped Wedge and Interrupted Time-Series Designs

PubMed Central

Ting Fok, Carlotta Ching; Henry, David; Allen, James

2015-01-01

The stepped wedge design (SWD) and the interrupted time-series design (ITSD) are two alternative research designs that maximize efficiency and statistical power with small samples when contrasted to the operating characteristics of conventional randomized controlled trials (RCT). This paper provides an overview and introduction to previous work with these designs, and compares and contrasts them with the dynamic wait-list design (DWLD) and the regression point displacement design (RPDD), which were presented in a previous article (Wyman, Henry, Knoblauch, and Brown, 2015) in this Special Section. The SWD and the DWLD are similar in that both are intervention implementation roll-out designs. We discuss similarities and differences between the SWD and DWLD in their historical origin and application, along with differences in the statistical modeling of each design. Next, we describe the main design characteristics of the ITSD, along with some of its strengths and limitations. We provide a critical comparative review of strengths and weaknesses in application of the ITSD, SWD, DWLD, and RPDD as small samples alternatives to application of the RCT, concluding with a discussion of the types of contextual factors that influence selection of an optimal research design by prevention researchers working with small samples. PMID:26017633

Comparing three cohorts of MSM sampled via sex parties, bars/clubs, and Craigslist.org: implications for researchers and providers.

PubMed

Grov, Christian; Rendina, H Jonathon; Parsons, Jeffrey T

2014-08-01

With limited exceptions, few studies have systematically reported on psychosocial and demographic characteristic differences in samples of men who have sex with men (MSM) based on where they were recruited. This study compared three sexually active cohorts of MSM recruited via Craigslist.org (recruited via modified time-space sampling), gay bars and clubs (recruited via time-space sampling), and private sex parties (identified via passive recruitment and listserves), finding mixed results with regard to differences in demographic characteristics, STI history, and psychosocial measures. Men recruited from sex parties were significantly older, reported more symptoms of sexual compulsivity, more likely to be HIV-positive, more likely to report a history of STIs, and more likely to self-identify as a barebacker, than men recruited from the other two venues. In contrast, men from Craigslist.org reported the lowest levels of attachment to the gay and bisexual community and were the least likely to self-identify as gay. Men from bars and clubs were significantly younger, and were more likely to report use of hallucinogens and crack or cocaine. Our findings highlight that the venues in which MSM are recruited have meaningful consequences in terms of the types of individuals who are reached.

Determination of lead in flour samples directly by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Tinas, Hande; Ozbek, Nil; Akman, Suleyman

2018-02-01

In this study, lead concentrations in various flour samples were determined by high-resolution continuum source graphite furnace atomic absorption spectrometry with solid sampling. Since samples were analyzed directly, the risks and disadvantages of sample digestion were eliminated. Solid flour samples were dried, weighed on the platforms, Pd was added as a modifier and introduced directly into a graphite tube using a manual solid sampler. Platforms and tubes were coated with Zr. The optimized pyrolysis and atomization temperatures were 800 °C and 2200 °C, respectively. The sensitivities of lead in various flour certified reference materials (CRMs) and aqueous standards were not significantly different. Therefore, aqueous standards were safely used for calibration. The absolute limit of detection and characteristic mass were 7.2 pg and 9.0 pg of lead, respectively. The lead concentrations in different types of flour samples were found in the range of 25-52 μg kg- 1. Finally, homogeneity factors representing the heterogeneity of analyte distribution for lead in flour samples were determined.

Population characteristics of channel catfish near the northern edge of their distribution: implications for management

USGS Publications Warehouse

Carter-Lynn, K. P.; Quist, Michael C.

2015-01-01

Channel catfish, Ictalurus punctatus (Rafinesque), populations in six lakes in northern Idaho, USA, were sampled to describe their population characteristics. During the summers of 2011 and 2012, 4864 channel catfish were sampled. Channel catfish populations had low to moderate catch rates, and length structure was dominated by fish <400 mm. Channel catfish were in good body condition. All populations were maintained by stocking age-1 or age-2 fish. Growth of fish reared in thermally enriched environments prior to stocking was fast compared to other North American channel catfish populations. After stocking, growth of channel catfish declined rapidly. Once stocked, cold water temperatures, prey resources and (or) genetic capabilities limited growth. Total annual mortality of age 2 and older channel catfish was generally <40%. Tag returns indicated that angler exploitation was low, varying from 0 to 43% among lakes. This research provides insight on factors regulating channel catfish population dynamics and highlights important considerations associated with their ecology and management.

Applications of two-photon fluorescence microscopy in deep-tissue imaging

NASA Astrophysics Data System (ADS)

Dong, Chen-Yuan; Yu, Betty; Hsu, Lily L.; Kaplan, Peter D.; Blankschstein, D.; Langer, Robert; So, Peter T. C.

2000-07-01

Based on the non-linear excitation of fluorescence molecules, two-photon fluorescence microscopy has become a significant new tool for biological imaging. The point-like excitation characteristic of this technique enhances image quality by the virtual elimination of off-focal fluorescence. Furthermore, sample photodamage is greatly reduced because fluorescence excitation is limited to the focal region. For deep tissue imaging, two-photon microscopy has the additional benefit in the greatly improved imaging depth penetration. Since the near- infrared laser sources used in two-photon microscopy scatter less than their UV/glue-green counterparts, in-depth imaging of highly scattering specimen can be greatly improved. In this work, we will present data characterizing both the imaging characteristics (point-spread-functions) and tissue samples (skin) images using this novel technology. In particular, we will demonstrate how blind deconvolution can be used further improve two-photon image quality and how this technique can be used to study mechanisms of chemically-enhanced, transdermal drug delivery.

Characteristics of lesbian, gay, bisexual, and transgender individuals entering substance abuse treatment.

PubMed

Cochran, Bryan N; Cauce, Ana Mari

2006-03-01

Previous research has suggested that lesbian, gay, bisexual, and transgender (LGBT) individuals enter treatment for substance abuse with more severe problems than heterosexual individuals. However, methodological difficulties, particularly the difficulty of obtaining a representative sample, have limited the ability to draw conclusions about LGBT individuals who receive services for substance abuse. This study took advantage of a unique opportunity to examine a representative sample of openly LGBT clients receiving publicly funded substance abuse treatment by using data gathered by treatment providers in Washington State. Baseline differences between openly LGBT and heterosexual clients were compared in a variety of domains. Results demonstrated that openly LGBT clients enter treatment with more severe substance abuse problems, greater psychopathology, and greater medical service utilization when compared with heterosexual clients. When the analyses were stratified based on sex, different patterns of substance use and associated psychosocial characteristics emerged for the LGBT clients. Implications for provision of appropriate services and recommendations to treatment agencies are discussed in this article.

Imaging a Large Sample with Selective Plane Illumination Microscopy Based on Multiple Fluorescent Microsphere Tracking

NASA Astrophysics Data System (ADS)

Ryu, Inkeon; Kim, Daekeun

2018-04-01

A typical selective plane illumination microscopy (SPIM) image size is basically limited by the field of view, which is a characteristic of the objective lens. If an image larger than the imaging area of the sample is to be obtained, image stitching, which combines step-scanned images into a single panoramic image, is required. However, accurately registering the step-scanned images is very difficult because the SPIM system uses a customized sample mount where uncertainties for the translational and the rotational motions exist. In this paper, an image registration technique based on multiple fluorescent microsphere tracking is proposed in the view of quantifying the constellations and measuring the distances between at least two fluorescent microspheres embedded in the sample. Image stitching results are demonstrated for optically cleared large tissue with various staining methods. Compensation for the effect of the sample rotation that occurs during the translational motion in the sample mount is also discussed.

Tensile experiments and SEM fractography on bovine subchondral bone.

PubMed

Braidotti, P; Bemporad, E; D'Alessio, T; Sciuto, S A; Stagni, L

2000-09-01

Subchondral bone undecalcified samples, extracted from bovine femoral heads, are subjected to a direct tensile load. The Young's modulus of each sample is determined from repeated tests within the elastic limit. In a last test, the tensile load is increased up to the specimen failure, determining the ultimate tensile strength. The investigation is performed on both dry and wet specimens. The measured Young's modulus for dry samples is 10.3+/-2.5GPa, while that of wet samples is 3.5+/-1.2GPa. The ultimate tensile strengths are 36+/-10 and 30+/-7.5MPa for dry and wet specimens, respectively. SEM micrographs of failure surfaces show characteristic lamellar bone structures, with lamellae composed of calcified collagen fibers. Rudimentary osteon-like structures are also observed. Failure surfaces of wet samples show a marked fiber pull-out, while delamination predominates in dry samples. The obtained results are interpreted on the basis of the deformation mechanisms typical of fiber-reinforced laminated composite materials.

ACS sampling system: design, implementation, and performance evaluation

NASA Astrophysics Data System (ADS)

Di Marcantonio, Paolo; Cirami, Roberto; Chiozzi, Gianluca

2004-09-01

By means of ACS (ALMA Common Software) framework we designed and implemented a sampling system which allows sampling of every Characteristic Component Property with a specific, user-defined, sustained frequency limited only by the hardware. Collected data are sent to various clients (one or more Java plotting widgets, a dedicated GUI or a COTS application) using the ACS/CORBA Notification Channel. The data transport is optimized: samples are cached locally and sent in packets with a lower and user-defined frequency to keep network load under control. Simultaneous sampling of the Properties of different Components is also possible. Together with the design and implementation issues we present the performance of the sampling system evaluated on two different platforms: on a VME based system using VxWorks RTOS (currently adopted by ALMA) and on a PC/104+ embedded platform using Red Hat 9 Linux operating system. The PC/104+ solution offers, as an alternative, a low cost PC compatible hardware environment with free and open operating system.

Determination of sulphur in various vegetables by solid sampling high-resolution electrothermal molecular absorption spectrometry.

PubMed

Gunduz, Sema; Akman, Suleyman

2015-04-01

Sulphur was determined in various vegetables via molecular absorption of carbon monosulphide (CS) at 258.056 nm using a solid sampling high resolution continuum source electrothermal atomic absorption spectrometer (SS HR-CS ETAAS). Samples were dried, ground and directly introduced into the ruthenium coated graphite furnace as 0.05 to 0.50mg. All determinations were performed using palladium+citric acid modifier and applying a pyrolysis temperature of 1000 °C and a volatilisation temperature of 2400 °C. The results were in good agreement with certified sulphur concentrations of various vegetal CRM samples applying linear calibration technique prepared from thioacetamide. The limit of detection and characteristic mass of the method were 7.5 and 8.7 ng of S, respectively. The concentrations of S in various spinach, leek, lettuce, radish, Brussels sprouts, zucchini and chard samples were determined. It was showed that distribution of sulphur in CRM and grinded food samples were homogeneous even in micro-scale. Copyright © 2014 Elsevier Ltd. All rights reserved.

Decomposition techniques

USGS Publications Warehouse

Chao, T.T.; Sanzolone, R.F.

1992-01-01

Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

Enhanced sampling techniques in molecular dynamics simulations of biological systems.

PubMed

Bernardi, Rafael C; Melo, Marcelo C R; Schulten, Klaus

2015-05-01

Molecular dynamics has emerged as an important research methodology covering systems to the level of millions of atoms. However, insufficient sampling often limits its application. The limitation is due to rough energy landscapes, with many local minima separated by high-energy barriers, which govern the biomolecular motion. In the past few decades methods have been developed that address the sampling problem, such as replica-exchange molecular dynamics, metadynamics and simulated annealing. Here we present an overview over theses sampling methods in an attempt to shed light on which should be selected depending on the type of system property studied. Enhanced sampling methods have been employed for a broad range of biological systems and the choice of a suitable method is connected to biological and physical characteristics of the system, in particular system size. While metadynamics and replica-exchange molecular dynamics are the most adopted sampling methods to study biomolecular dynamics, simulated annealing is well suited to characterize very flexible systems. The use of annealing methods for a long time was restricted to simulation of small proteins; however, a variant of the method, generalized simulated annealing, can be employed at a relatively low computational cost to large macromolecular complexes. Molecular dynamics trajectories frequently do not reach all relevant conformational substates, for example those connected with biological function, a problem that can be addressed by employing enhanced sampling algorithms. This article is part of a Special Issue entitled Recent developments of molecular dynamics. Copyright © 2014 Elsevier B.V. All rights reserved.

Adaptive Sensing of Time Series with Application to Remote Exploration

NASA Technical Reports Server (NTRS)

Thompson, David R.; Cabrol, Nathalie A.; Furlong, Michael; Hardgrove, Craig; Low, Bryan K. H.; Moersch, Jeffrey; Wettergreen, David

2013-01-01

We address the problem of adaptive informationoptimal data collection in time series. Here a remote sensor or explorer agent throttles its sampling rate in order to track anomalous events while obeying constraints on time and power. This problem is challenging because the agent has limited visibility -- all collected datapoints lie in the past, but its resource allocation decisions require predicting far into the future. Our solution is to continually fit a Gaussian process model to the latest data and optimize the sampling plan on line to maximize information gain. We compare the performance characteristics of stationary and nonstationary Gaussian process models. We also describe an application based on geologic analysis during planetary rover exploration. Here adaptive sampling can improve coverage of localized anomalies and potentially benefit mission science yield of long autonomous traverses.

Identification of PM{sub 10} characteristics involved in cellular responses in human bronchial epithelial cells (Beas-2B)

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

Van Den Heuvel, Rosette, E-mail: rosette.vandenheuvel@vito.be; Den Hond, Elly, E-mail: elly.denhond@wiv-isp.be; Govarts, Eva, E-mail: eva.govarts@vito.be

Notwithstanding evidence is present that physicochemical characteristics of ambient particles attribute to adverse health effects, there is still some lack of understanding in this complex relationship. At this moment it is not clear which properties (such as particle size, chemical composition) or sources of the particles are most relevant for health effects. This study investigates the in vitro toxicity of PM{sub 10} in relation to PM chemical composition, black carbon (BC), endotoxin content and oxidative potential (OP). In 2013–2014 PM{sub 10} was sampled (24 h sampling, 108 sampling days) in ambient air at three sites in Flanders (Belgium) with differentmore » pollution characteristics: an urban traffic site (Borgerhout), an industrial area (Zelzate) and a rural background location (Houtem). To characterize the toxic potential of PM{sub 10}, airway epithelial cells (Beas-2B cells) have been exposed to particles in vitro. Different endpoints were studied including cell damage and death (cell viability) using the Neutral red Uptake assay, the production of pro-inflammatory molecules by interleukin 8 (IL-8) induction and DNA-damaging activity using the FPG-modified Comet assay. The endotoxin levels in the collected samples were analysed and the capacity of PM{sub 10} particles to produce reactive oxygen species (OP) was evaluated by electron paramagnetic resonance (EPR) spectroscopy. Chemical characteristics of PM{sub 10} (BC, As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) and meteorological conditions were recorded on the sampling days. PM{sub 10} particles exhibited dose-dependent cytotoxicity in Beas-2B cells and were found to significantly induce the release of IL-8 in samples from the three locations. Oxidatively damaged DNA was observed in exposed Beas-2B cells. Endotoxin levels above the detection limit were detected in half of the samples. OP was measurable in all samples. Associations between PM{sub 10} characteristics and biological effects of PM{sub 10} were assessed by single and multiple regression analyses. The reduction in cell viability was significantly correlated with BC, Cd and Pb. The induction of IL-8 in Beas-2B cells was significantly associated with Cu, Ni and Zn and endotoxin. Endotoxin levels explained 33% of the variance in IL-8 induction. A significant interaction between ambient temperature and endotoxin on the pro-inflammatory activity was seen. No association was found between OP and the cellular responses. This study supports the hypothesis that, on an equal mass basis, PM{sub 10} induced biological effects differ due to differences in PM{sub 10} characteristics. Metals (Cd, Cu, Ni and Zn), BC, and endotoxin were among the main determinants for the observed biological responses. - Highlights: • On an equal mass basis, PM{sub 10} sampled at an urban, rural and industrial site induced different cellular effects in Beas-2B. • Endotoxin levels and oxidative potential (OP) were analysed in the PM{sub 10} samples. • Black carbon, cadmium and lead were correlated with decreased cell viability. • Endotoxin levels explained the majority of the variance in il-8 induction. • Oxidatively damaged DNA was observed in all the samples.« less

Factors Related to Attrition from VA Healthcare Use: Findings from the National Survey of Women Veterans

DTIC Science & Technology

2013-01-01

present analysis we draw on aspects of the Andersen Behavioral Model,21 particularly need characteristics (e.g., mental health), as determinants of...converted to number of years ago. Number of years since last VA use was grouped into five-year increments. Statistical Analysis The analytic sample was...healthcare several decades ago. A limitation of our study is that recollections about the decision to discontinue VA care are subject to recall bias

Quasi-microscope concept for planetary missions.

PubMed

Huck, F O; Arvidson, R E; Burcher, E E; Giat, O; Wall, S D

1977-09-01

Viking lander cameras have returned stereo and multispectral views of the Martian surface with a resolution that approaches 2 mm/lp in the near field. A two-orders-of-magnitude increase in resolution could be obtained for collected surface samples by augmenting these cameras with auxiliary optics that would neither impose special camera design requirements nor limit the cameras field of view of the terrain. Quasi-microscope images would provide valuable data on the physical and chemical characteristics of planetary regoliths.

Median nitrate concentrations in groundwater in the New Jersey Highlands Region estimated using regression models and land-surface characteristics

USGS Publications Warehouse

Baker, Ronald J.; Chepiga, Mary M.; Cauller, Stephen J.

2015-01-01

The Kaplan-Meier method of estimating summary statistics from left-censored data was applied in order to include nondetects (left-censored data) in median nitrate-concentration calculations. Median concentrations also were determined using three alternative methods of handling nondetects. Treatment of the 23 percent of samples that were nondetects had little effect on estimated median nitrate concentrations because method detection limits were mostly less than median values.

Small Rov Marine Boat for Bathymetry Surveys of Shallow Waters - Potential Implementation in Malaysia

NASA Astrophysics Data System (ADS)

Suhari, K. T.; Karim, H.; Gunawan, P. H.; Purwanto, H.

2017-10-01

Current practices in bathymetry survey (available method) are indeed having some limitations. New technologies for bathymetry survey such as using unmanned boat has becoming popular in developed countries - filled in and served those limitations of existing survey methods. Malaysia as one of tropical country has it own river/water body characteristics and suitable approaches in conducting bathymetry survey. Thus, a study on this emerging technology should be conducted using enhanced version of small ROV boat with Malaysian rivers and best approaches so that the surveyors get benefits from the innovative surveying product. Among the available ROV boat for bathymetry surveying in the market, an Indonesian product called SHUMOO is among the promising products - economically and practically proven using a few sample areas in Indonesia. The boat was equipped and integrated with systems of remote sensing technology, GNSS, echo sounder and navigational engine. It was designed for riverbed surveys on shallow area such as small /medium river, lakes, reservoirs, oxidation/detention pond and other water bodies. This paper tries to highlight the needs and enhancement offered to Malaysian' bathymetry surveyors/practitioners on the new ROV boat which make their task easier, faster, safer, economically effective and better riverbed modelling results. The discussion continues with a sample of Indonesia river (data collection and modelling) since it is mostly similar to Malaysia's river characteristics and suggests some improvement for Malaysia best practice.

Patient and caregiver characteristics related to completion of advance directives in terminally ill patients.

PubMed

Ho, Grace W K; Skaggs, Lauren; Yenokyan, Gayane; Kellogg, Anela; Johnson, Julie A; Lee, Mei Ching; Heinze, Katherine; Hughes, Mark T; Sulmasy, Daniel P; Kub, Joan; Terry, Peter B; Astrow, Alan B; Zheng, Jing; Lehmann, Lisa Soleymani; Nolan, Marie T

2017-02-01

There is a growing body of literature describing the characteristics of patients who plan for the end of life, but little research has examined how caregivers influence patients' advance care planning (ACP). The purpose of this study was to examine how patient and caregiver characteristics are associated with advance directive (AD) completion among patients diagnosed with a terminal illness. We defined AD completion as having completed a living will and/or identified a healthcare power of attorney. A convenience sample of 206 caregiver-patient dyads was included in the study. All patients were diagnosed with an advanced life-limiting illness. Trained research nurses administered surveys to collect information on patient and caregiver demographics (i.e., age, sex, race, education, marital status, and individual annual income) and patients' diagnoses and completion of AD. Multivariate logistic regression was employed to model predictors for patients' AD completion. Over half of our patient sample (59%) completed an AD. Patients who were older, diagnosed with amyotrophic lateral sclerosis, and with a caregiver who was Caucasian or declined to report an income level were more likely to have an AD in place. Our results suggest that both patient and caregiver characteristics may influence patients' decisions to complete an AD at the end of life. When possible, caregivers should be included in advance care planning for patients who are terminally ill.

Characteristics of several NIR tuneable diode lasers for spectroscopic based gas sensing: a comparison.

PubMed

Weldon, Vincent; McInerney, David; Phelan, Richard; Lynch, Michael; Donegan, John

2006-04-01

Tuneable laser diodes were characterized and compared for use as tuneable sources in gas absorption spectroscopy. Specifically, the characteristics of monolithic widely tuneable single frequency lasers, such as sampled grating distributed Bragg reflector laser and modulated grating Y-branch laser diodes, recently developed for optical communications, with operating wavelengths in the 1,520 nm

IRAS variables as galactic structure tracers - Classification of the bright variables

NASA Technical Reports Server (NTRS)

Allen, L. E.; Kleinmann, S. G.; Weinberg, M. D.

1993-01-01

The characteristics of the 'bright infrared variables' (BIRVs), a sample consisting of the 300 brightest stars in the IRAS Point Source Catalog with IRAS variability index VAR of 98 or greater, are investigated with the purpose of establishing which of IRAS variables are AGB stars (e.g., oxygen-rich Miras and carbon stars, as was assumed by Weinberg (1992)). Results of the analysis of optical, infrared, and microwave spectroscopy of these stars indicate that, out of 88 stars in the BIRV sample identified with cataloged variables, 86 can be classified as Miras. Results of a similar analysis performed for a color-selected sample of stars, using the color limits employed by Habing (1988) to select AGB stars, showed that, out of 52 percent of classified stars, 38 percent are non-AGB stars, including H II regions, planetary nebulae, supergiants, and young stellar objects, indicating that studies using color-selected samples are subject to misinterpretation.

A United States forensic sample for the Gudjonsson Suggestibility Scales.

PubMed

Frumkin, I Bruce; Lally, Stephen J; Sexton, James E

2012-01-01

The Gudjonsson Suggestibility Scales (GSS) is a valuable test to use as part of a comprehensive assessment of psychological and interrogative factors relevant to a defendant's vulnerability to giving a false or involuntary confession. One limitation of the test is that the manual only provides information for samples from Iceland and Great Britain. This report describes the results of 334 individuals in the United States, who were administered the tests as part of an evaluation to assess confession-related issues in a forensic context (i.e., capacity to waive Miranda rights or vulnerability in providing a false or involuntary confession). This forensic sample includes both juveniles and adults. Results are consistent with Gudjonsson's British and Icelandic samples, in which the Yield 1 score is more affected by intellectual and cognitive variables, but Shift and, to a lesser extent, Yield 2 scores are more related to emotional and personality characteristics. Copyright © 2012 John Wiley & Sons, Ltd.

Multi-Frequency Signal Detection Based on Frequency Exchange and Re-Scaling Stochastic Resonance and Its Application to Weak Fault Diagnosis

PubMed Central

Leng, Yonggang; Fan, Shengbo

2018-01-01

Mechanical fault diagnosis usually requires not only identification of the fault characteristic frequency, but also detection of its second and/or higher harmonics. However, it is difficult to detect a multi-frequency fault signal through the existing Stochastic Resonance (SR) methods, because the characteristic frequency of the fault signal as well as its second and higher harmonics frequencies tend to be large parameters. To solve the problem, this paper proposes a multi-frequency signal detection method based on Frequency Exchange and Re-scaling Stochastic Resonance (FERSR). In the method, frequency exchange is implemented using filtering technique and Single SideBand (SSB) modulation. This new method can overcome the limitation of "sampling ratio" which is the ratio of the sampling frequency to the frequency of target signal. It also ensures that the multi-frequency target signals can be processed to meet the small-parameter conditions. Simulation results demonstrate that the method shows good performance for detecting a multi-frequency signal with low sampling ratio. Two practical cases are employed to further validate the effectiveness and applicability of this method. PMID:29693577

Design of a sampling plan to detect ochratoxin A in green coffee.

PubMed

Vargas, E A; Whitaker, T B; Dos Santos, E A; Slate, A B; Lima, F B; Franca, R C A

2006-01-01

The establishment of maximum limits for ochratoxin A (OTA) in coffee by importing countries requires that coffee-producing countries develop scientifically based sampling plans to assess OTA contents in lots of green coffee before coffee enters the market thus reducing consumer exposure to OTA, minimizing the number of lots rejected, and reducing financial loss for producing countries. A study was carried out to design an official sampling plan to determine OTA in green coffee produced in Brazil. Twenty-five lots of green coffee (type 7 - approximately 160 defects) were sampled according to an experimental protocol where 16 test samples were taken from each lot (total of 16 kg) resulting in a total of 800 OTA analyses. The total, sampling, sample preparation, and analytical variances were 10.75 (CV = 65.6%), 7.80 (CV = 55.8%), 2.84 (CV = 33.7%), and 0.11 (CV = 6.6%), respectively, assuming a regulatory limit of 5 microg kg(-1) OTA and using a 1 kg sample, Romer RAS mill, 25 g sub-samples, and high performance liquid chromatography. The observed OTA distribution among the 16 OTA sample results was compared to several theoretical distributions. The 2 parameter-log normal distribution was selected to model OTA test results for green coffee as it gave the best fit across all 25 lot distributions. Specific computer software was developed using the variance and distribution information to predict the probability of accepting or rejecting coffee lots at specific OTA concentrations. The acceptation probability was used to compute an operating characteristic (OC) curve specific to a sampling plan design. The OC curve was used to predict the rejection of good lots (sellers' or exporters' risk) and the acceptance of bad lots (buyers' or importers' risk).

Substrate quality and nutrient availability influence CO2 production from tropical peat decomposition

NASA Astrophysics Data System (ADS)

Swails, E.; Jaye, D.; Verchot, L. V.; Hergoualc'h, K.; Wahyuni, N. S.; Borchard, N.; Lawrence, D.

2015-12-01

In Indonesia, peatlands are a major and growing source of greenhouse gas emissions due to increasing pressure from oil palm and pulp wood plantations. We are using a combination of field measures, laboratory experiments, and remote sensing to investigate relationships among land use, climatic factors and biogeochemical controls, and their influence on trace gas fluxes from tropical peat soils. Analysis of soils collected from peat sites on two major islands indicated substantial variation in peat substrate quality and nutrient content among land uses and geographic location. We conducted laboratory incubations to test the influence of substrate quality and nutrient availability on CO2 production from peat decomposition. Differences in peat characteristics attributable to land use change were tested by comparison of forest and oil palm peat samples collected from the same peat dome in Kalimantan. Regional differences in peat characteristics were tested by comparison of samples from Sumatra with samples from Kalimantan. We conducted additional experiments to test the influence of N and P availability and labile carbon on CO2 production. Under moisture conditions typical of oil palm plantations, CO2 production was higher from peat forest samples than from oil palm samples. CO2 production from Sumatra and Kalimantan oil palm samples was not different, despite apparent differences in nutrient content of these soils. N and P treatments representative of fertilizer application rates raised CO2 production from forest samples but not oil palm samples. Labile carbon treatments raised CO2 production in all samples. Our results suggest that decomposition of peat forest soils is nutrient limited, while substrate quality controls decomposition of oil palm soils post-conversion. Though fertilizer application could accelerate peat decomposition initially, fertilizer application may not influence long-term CO2 emissions from oil palm on peat.

Systematic Review of the Use of Online Questionnaires among the Geriatric Population

PubMed Central

Remillard, Meegan L.; Mazor, Kathleen M.; Cutrona, Sarah L.; Gurwitz, Jerry H.; Tjia, Jennifer

2014-01-01

Background/Objectives The use of internet-based questionnaires to collect information from older adults is not well established. This systematic literature review of studies using online questionnaires in older adult populations aims to 1. describe methodologic approaches to population targeting and sampling and 2. summarize limitations of Internet-based questionnaires in geriatric populations. Design, Setting, Participants We identified English language articles using search terms for geriatric, age 65 and over, Internet survey, online survey, Internet questionnaire, and online questionnaire in PubMed and EBSCO host between 1984 and July 2012. Inclusion criteria were: study population mean age ≥65 years old and use of an online questionnaire for research. Review of 336 abstracts yielded 14 articles for full review by 2 investigators; 11 articles met inclusion criteria. Measurements Articles were extracted for study design and setting, patient characteristics, recruitment strategy, country, and study limitations. Results Eleven (11) articles were published after 2001. Studies had populations with a mean age of 65 to 78 years, included descriptive and analytical designs, and were conducted in the United States, Australia, and Japan. Recruiting methods varied widely from paper fliers and personal emails to use of consumer marketing panels. Investigator-reported study limitations included the use of small convenience samples and limited generalizability. Conclusion Online questionnaires are a feasible method of surveying older adults in some geographic regions and for some subsets of older adults, but limited Internet access constrains recruiting methods and often limits study generalizability. PMID:24635138

A STUDY ON THE PERSONALITY CHARACTERISTICS OF WIVES OF ALCOHOLICS

PubMed Central

Rao, T.S. Sathyanarayana; Kuruvilla, K.

1991-01-01

SUMMARY A study is conducted for assessment of personality characteristic using EPI & 16 PF on wives of 30 primary alcoholics who satisfied Feighner's Criteria and were compared with the wives of 30 normal controls matched on imrital an socio-demographic variables. There were no statistically significant differences between the two groups on EPI and scores were within normal limits. Both the groups had a similar profile scores on 16 PF being submissive, timid, trustful, conventional, conservative, dependent and poised. These findings were not in favour of the concept of “Pathological wives” causing alcoholism in their husbands as advocated by some western studies. Personality characteristics of our sample in general were significantly different from normative data for western women, where the latter were more dominant, a leventurous and self-sufficient. Implications of these findings are discussed in the light of our socio-cultural context. PMID:21927498

River Flow Impacts Bacterial and Archaeal Community Structure in Surface Sediments in the Northern Gulf of Mexico.

PubMed

Ortmann, Alice C; Brannock, Pamela M; Wang, Lei; Halanych, Kenneth M

2018-04-17

Meiobenthic community structure in the northern Gulf of Mexico has been shown to be driven by geographical differences due to inshore-offshore gradients and location relative to river discharge. Samples collected along three transects spanning Mobile Bay, Alabama, showed significant differences in meiobenthic communities east of the bay compared to those sampled from the west. In contrast, analysis of bacterial and archaeal communities from the same sediment samples shows that the inshore-offshore gradient has minimal impact on their community structure. Significant differences in community structure were observed for Bacteria and Archaea between the east and west samples, but there was no difference in richness or diversity. Grouped by sediment type, higher richness was observed in silty samples compared to sandy samples. Significant differences were also observed among sediment types for community structure with bacteria communities in silty samples having more anaerobic sulfate reducers compared to aerobic heterotrophs, which had higher abundances in sandy sediments. This is likely due to increased organic matter in the silty sediments from the overlying river leading to low oxygen habitats. Most archaeal sequences represented poorly characterized high-level taxa, limiting interpretation of their distributions. Overlap between groups based on transect and sediment characteristics made determining which factor is more important in structuring bacterial and archaeal communities difficult. However, both factors are driven by discharge from the Mobile River. Although inshore-offshore gradients do not affect Bacteria or Archaea to the same extent as the meiobenthic communities, all three groups are strongly affected by sediment characteristics.

The role of landscape and habitat characteristics in limiting abundance of grassland nesting songbirds in an urban open space

USGS Publications Warehouse

Haire, S.; Bock, C.E.; Cade, B.S.; Bennett, B.C.

2000-01-01

We examine the relationships between abundance of grassland nesting songbirds observed in the Boulder Open Space, CO, USA and parameters that described landscape and habitat characteristics, in order to provide information for Boulder Open Space planners and managers. Data sets included bird abundance and plant species composition, collected during three breeding seasons (1994–1996), and landscape composition and configuration measures from a satellite image-derived land-cover map. We used regression quantiles to estimate the limitations imposed on bird abundance by urban encroachment and decreasing areas of grassland cover-types on the landscape, and habitat characteristics within 200 m diameter sample plots. After accounting for the effect of landscape grassland composition on four species (Western Meadowlark (Sturnella neglecta), Vesper Sparrow (Pooecetes gramineus), Horned Lark (Eremophila alpestris), and Grasshopper Sparrow (Ammodramus savannarum)), change in abundance with proportion of urban area in the landscape was consistent with the pattern expected for limiting factors that were the active constraint at some times and places. Area of preferred grassland cover-types on the landscape was important for all species, and this remained the case when habitat variables were included in combined landscape–habitat models, with one exception (Western Meadowlark). Analysis of habitat variables enabled identification of important features at the local scale (e.g. shale plant communities in Lark Sparrow (Chondestes grammacus) habitat) that were indistinguishable using landscape data alone. Consideration of changes in the landscape due to urbanization and loss of grassland habitat are crucial for open space planning, and habitat features associated with localized and clumped bird species distributions provide important additional information. Widening the management focus to include areas that are not part of the open space system will facilitate a more complete understanding of potential limiting factor processes.

The end of the MACHO era, revisited: New limits on MACHO masses from halo wide binaries

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

Monroy-Rodríguez, Miguel A.; Allen, Christine, E-mail: chris@astro.unam.mx

2014-08-01

In order to determine an upper bound for the mass of the massive compact halo objects (MACHOs), we use the halo binaries contained in a recent catalog by Allen and Monroy-Rodríguez. To dynamically model their interactions with massive perturbers, a Monte Carlo simulation is conducted, using an impulsive approximation method and assuming a galactic halo constituted by massive particles of a characteristic mass. The results of such simulations are compared with several subsamples of our improved catalog of candidate halo wide binaries. In accordance with Quinn et al., we also find our results to be very sensitive to the widestmore » binaries. However, our larger sample, together with the fact that we can obtain galactic orbits for 150 of our systems, allows a more reliable estimate of the maximum MACHO mass than that obtained previously. If we employ the entire sample of 211 candidate halo stars we, obtain an upper limit of 112 M{sub ☉}. However, using the 150 binaries in our catalog with computed galactic orbits, we are able to refine our fitting criteria. Thus, for the 100 most halo-like binaries we obtain a maximum MACHO mass of 21-68 M{sub ☉}. Furthermore, we can estimate the dynamical effects of the galactic disk using binary samples that spend progressively shorter times within the disk. By extrapolating the limits obtained for our most reliable—albeit smallest—sample, we find that as the time spent within the disk tends to zero, the upper bound of the MACHO mass tends to less than 5 M{sub ☉}. The non-uniform density of the halo has also been taken into account, but the limit obtained, less than 5 M{sub ☉}, does not differ much from the previous one. Together with microlensing studies that provide lower limits on the MACHO mass, our results essentially exclude the existence of such objects in the galactic halo.« less

Residential distance to major roadways and semen quality, sperm DNA integrity, chromosomal disomy, and serum reproductive hormones among men attending a fertility clinic.

PubMed

Nassan, Feiby L; Chavarro, Jorge E; Mínguez-Alarcón, Lidia; Williams, Paige L; Tanrikut, Cigdem; Ford, Jennifer B; Dadd, Ramace; Perry, Melissa J; Hauser, Russ; Gaskins, Audrey J

2018-06-01

We examined associations of residential distance to major roadways, as a proxy for traffic-related air pollution exposures, with sperm characteristics and male reproductive hormones. The cohort included 797 men recruited from Massachusetts General Hospital Fertility Center between 2000 and 2015 to participate in fertility research studies. Men reported their residential addresses at enrollment and provided 1-6 semen samples and a blood sample during follow-up. We estimated the Euclidean distance to major roadways (e.g. interstates and highways: limited access highways, multi-lane highways (not limited access), other numbered routes, and major roads) using information from the Massachusetts Department of Geographic Information Systems. Semen parameters (1238 semen samples), sperm DNA integrity (389 semen samples), chromosomal disomy (101 semen samples), and serum reproductive hormones (405 serum samples) were assessed following standard procedures. Men in this cohort were primarily Caucasian (86%), not current smokers (92%), with a college or higher education (88%), and had an average age of 36 years and BMI of 27.7 kg/m 2 . The median (interquartile range) residential distance to a major roadway was 111 (37, 248) meters. Residential proximity to major roadways was not associated with semen parameters, sperm DNA integrity, chromosomal disomy, or serum reproductive hormone concentrations. The adjusted percent change (95% CI) in semen quality parameters associated with a 500 m increase in residential distance to a major roadway was -1.0% (-6.3, 4.5) for semen volume, 4.3% (-5.8, 15.7) for sperm concentration, 3.1% (-7.2, 14.5) for sperm count, 1.1% (-1.2, 3.4) for % total motile sperm, and 0.1% (-0.3, 0.5) for % morphologically normal sperm. Results were consistent when we modeled the semen parameters dichotomized according to WHO 2010 reference values. Residential distance to major roadways, as a proxy for traffic-related air pollution exposure, was not related to sperm characteristics or serum reproductive hormones among men attending a fertility clinic in Massachusetts. Copyright © 2018 Elsevier GmbH. All rights reserved.

Suns-VOC characteristics of high performance kesterite solar cells

NASA Astrophysics Data System (ADS)

Gunawan, Oki; Gokmen, Tayfun; Mitzi, David B.

2014-08-01

Low open circuit voltage (VOC) has been recognized as the number one problem in the current generation of Cu2ZnSn(Se,S)4 (CZTSSe) solar cells. We report high light intensity and low temperature Suns-VOC measurement in high performance CZTSSe devices. The Suns-VOC curves exhibit bending at high light intensity, which points to several prospective VOC limiting mechanisms that could impact the VOC, even at 1 sun for lower performing samples. These VOC limiting mechanisms include low bulk conductivity (because of low hole density or low mobility), bulk or interface defects, including tail states, and a non-ohmic back contact for low carrier density CZTSSe. The non-ohmic back contact problem can be detected by Suns-VOC measurements with different monochromatic illuminations. These limiting factors may also contribute to an artificially lower JSC-VOC diode ideality factor.

Using built environment characteristics to predict walking for exercise

PubMed Central

Lovasi, Gina S; Moudon, Anne V; Pearson, Amber L; Hurvitz, Philip M; Larson, Eric B; Siscovick, David S; Berke, Ethan M; Lumley, Thomas; Psaty, Bruce M

2008-01-01

Background Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for exercise. Study participants lived in western Washington State and were adult members of a health maintenance organization. The physical activity data used in this study were collected by telephone interview and were selected for their relevance to cardiovascular disease. In order to limit confounding by prior health conditions, the sample was restricted to participants in good self-reported health and without a documented history of cardiovascular disease. Results For 1,608 participants meeting the inclusion criteria, the mean age was 64 years, 90 percent were white, 37 percent had a college degree, and 62 percent of participants reported that they walked for exercise. Single built environment characteristics, such as residential density or connectivity, did not significantly predict walking for exercise. Regression models using multiple built environment characteristics to predict walking were not successful at predicting walking for exercise in an independent population sample. In the validation set, none of the logistic models had a C-statistic confidence interval excluding the null value of 0.5, and none of the linear models explained more than one percent of the variance in time spent walking for exercise. We did not detect significant differences in walking for exercise among census areas or postal codes, which were used as proxies for neighborhoods. Conclusion None of the built environment characteristics significantly predicted walking for exercise, nor did combinations of these characteristics predict walking for exercise when tested using a holdout approach. These results reflect a lack of neighborhood-level variation in walking for exercise for the population studied. PMID:18312660

DNA biosensor for detection of Salmonella typhi from blood sample of typhoid fever patient using gold electrode modified by self-assembled monolayers of thiols

NASA Astrophysics Data System (ADS)

Suryapratiwi, Windha Novita; Paat, Vlagia Indira; Gaffar, Shabarni; Hartati, Yeni Wahyuni

2017-05-01

Electrochemical biosensors are currently being developed in order to handle various clinical problems in diagnosing infectious diseases caused by pathogenic bacteria, or viruses. On this research, voltammetric DNA biosensor using gold electrode modified by thiols with self-assembled monolayers had been developed to detect a certain sequence of Salmonella typhi DNA from blood sample of typhoid fever patient. Thiol groups of cysteamines (Cys) and aldehyde groups from glutaraldehydes (Glu) were used as a link to increase the performance of gold electrode in detecting guanine oxidation signal of hybridized S. typhi DNA and ssDNA probe. Standard calibration method was used to determine analytical parameters from the measurements. The result shown that, the detection of S. typhi DNA from blood sample of typhoid fever patient can be carried out by voltammetry using gold electrode modified by self-assembled monolayers of thiols. A characteristic oxidation potential of guanine using Au/Cys/Gluwas obtained at +0.17 until +0.20 V. Limit of detection and limit of quantification from this measurements were 1.91μg mL-1 and 6.35 μg mL-1. The concentration of complement DNA from sample was 6.96 μg mL-1.

Patterns of Technology Use Among Older Adults With and Without Disabilities

PubMed Central

Gell, Nancy M.; Rosenberg, Dori E.; Demiris, George; LaCroix, Andrea Z.; Patel, Kushang V.

2015-01-01

Purpose of the Study: The purpose of this study was to describe prevalence of technology use among adults ages 65 and older, particularly for those with disability and activity-limiting symptoms and impairments. Design and Methods: Data from the 2011 National Health and Aging Trends Study, a nationally representative sample of community-dwelling Medicare beneficiaries (N = 7,609), were analyzed. Analysis consisted of technology use (use of e-mail/text messages and the internet) by sociodemographic and health characteristics and prevalence ratios for technology usage by disability status. Results: Forty percent of older adults used e-mail or text messaging and 42.7% used the internet. Higher prevalence of technology use was associated with younger age, male sex, white race, higher education level, and being married (all p values <.001). After adjustment for sociodemographic and health characteristics, technology use decreased significantly with greater limitations in physical capacity and greater disability. Vision impairment and memory limitations were also associated with lower likelihood of technology use. Implications: Technology usage in U.S. older adults varied significantly by sociodemographic and health status. Prevalence of technology use differed by the type of disability and activity-limiting impairments. The internet, e-mail, and text messaging might be viable mediums for health promotion and communication, particularly for younger cohorts of older adults and those with certain types of impairment and less severe disability. PMID:24379019

Extrapolation of dynamic load behaviour on hydroelectric turbine blades with cyclostationary modelling

NASA Astrophysics Data System (ADS)

Poirier, Marc; Gagnon, Martin; Tahan, Antoine; Coutu, André; Chamberland-lauzon, Joël

2017-01-01

In this paper, we present the application of cyclostationary modelling for the extrapolation of short stationary load strain samples measured in situ on hydraulic turbine blades. Long periods of measurements allow for a wide range of fluctuations representative of long-term reality to be considered. However, sampling over short periods limits the dynamic strain fluctuations available for analysis. The purpose of the technique presented here is therefore to generate a representative signal containing proper long term characteristics and expected spectrum starting with a much shorter signal period. The final objective is to obtain a strain history that can be used to estimate long-term fatigue behaviour of hydroelectric turbine runners.

[Study on Different Parts of Wild and Cultivated Gentiana Rigescens with Fourier Transform Infrared Spectroscopy].

PubMed

Shen, Yun-xia; Zhao, Yan-li; Zhang, Ji; Zuo, Zhi-tian; Wang, Yuan-zhong; Zhang, Qing-zhi

2016-03-01

The application of traditional Chinese medicine (TCM) and their preparations have a long history. With the deepening of the research, the market demand is increasing. However, wild resources are so limited that it can not meet the needs of the market. The development of wild and cultivated samples and research on accumulation dynamics of chemical component are of great significance. In order to compare composition difference of different parts (root, stem, and leaf) of wild and cultivated G. rigescens, Fourier infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate. The second derivative spectra of 60 samples and the rate of affinity (the match values) were measured automatically using the appropriate software (Omnic 8.0). The results showed that the various parts of wild and cultivated G. rigescens. were high similar the peaks at 1732, 1 643, 1 613, 1 510, 1 417, 1 366, 1 322, 1 070 cm(-1) were the characteristic peak of esters, terpenoids and saccharides, respectively. Moreover, the shape and peak intensity were more distinct in the second derivative spectrum of samples. In the second derivative spectrum range of 1 800-600 cm(-1), the fingerprint characteristic peak of samples and gentiopicroside standards were 1 679, 1 613, 1 466, 1 272, 1 204, 1 103, 1 074, 985, 935 cm(-1). The characteristic peak intensity of gentiopicroside of roots of wild and cultivated samples at 1 613 cm(-1) (C-C) was higher than stems and leaves which indicated the higher content of gentiopicroside in root than in stem and leaves. Stems of wild samples at 1 521, 1 462 and 1 452 cm(-1) are the skeletal vibration peak of benzene ring of lignin, and the stem of cultivated sample have stronger peak than other samples which showed that rich lignin in stems. The iInfrared spectrum of samples were similar with the average spectral of root of wild samples, and significant difference was found for the correlation between second derivative spectrum of samples and average spectral of wild samples root, and the sequence of similarity was root > stem > leaf. Therefore, FTIR combined with second derivative spectra was an express and comprehensive approach to analyze and evaluate in the imperceptible differences among different parts of wild and cultivated of G. rigescens.

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.

Imaging quality evaluation method of pixel coupled electro-optical imaging system

NASA Astrophysics Data System (ADS)

He, Xu; Yuan, Li; Jin, Chunqi; Zhang, Xiaohui

2017-09-01

With advancements in high-resolution imaging optical fiber bundle fabrication technology, traditional photoelectric imaging system have become ;flexible; with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the coupling discrete sampling effect of fiber-optic image bundles and charge-coupled device (CCD) pixels. This limitation substantially complicates the design, optimization, assembly, and evaluation image quality of the coupled discrete sampling imaging system. Based on the transfer process of grayscale cosine distribution optical signal in the fiber-optic image bundle and CCD, a mathematical model of coupled modulation transfer function (coupled-MTF) is established. This model can be used as a basis for following studies on the convergence and periodically oscillating characteristics of the function. We also propose the concept of the average coupled-MTF, which is consistent with the definition of traditional MTF. Based on this concept, the relationships among core distance, core layer radius, and average coupled-MTF are investigated.

Driver gene classification reveals a substantial overrepresentation of tumor suppressors among very large chromatin-regulating proteins.

PubMed

Waks, Zeev; Weissbrod, Omer; Carmeli, Boaz; Norel, Raquel; Utro, Filippo; Goldschmidt, Yaara

2016-12-23

Compiling a comprehensive list of cancer driver genes is imperative for oncology diagnostics and drug development. While driver genes are typically discovered by analysis of tumor genomes, infrequently mutated driver genes often evade detection due to limited sample sizes. Here, we address sample size limitations by integrating tumor genomics data with a wide spectrum of gene-specific properties to search for rare drivers, functionally classify them, and detect features characteristic of driver genes. We show that our approach, CAnceR geNe similarity-based Annotator and Finder (CARNAF), enables detection of potentially novel drivers that eluded over a dozen pan-cancer/multi-tumor type studies. In particular, feature analysis reveals a highly concentrated pool of known and putative tumor suppressors among the <1% of genes that encode very large, chromatin-regulating proteins. Thus, our study highlights the need for deeper characterization of very large, epigenetic regulators in the context of cancer causality.

A HST Search to Constrain the Binary Fraction of Stripped-Envelope Supernovae

NASA Astrophysics Data System (ADS)

Fox, Ori

2018-01-01

Stripped-envelope supernovae (e.g., SNe IIb, Ib, and Ic) refer to a subset of core-collapse explosions with progenitors that have lost some fraction of their outer envelopes in pre-SN mass loss. Mounting evidence over the past decade suggests that the mass loss in a large fraction of these systems occurs due to binary interaction. An unbiased, statistically significant sample of companion-star characteristics (including deep upper limits) can constrain the binary fraction, having direct implications on the theoretical physics of both single star and binary evolution. To date, however, only two detections have been made: SNe 1993J and 2011dh. Over the past year, we have improved this sample with an HST WFC3/NUV survey for binary companions of three additional nearby stripped-envelope SNe: 2002ap, 2001ig, and 2010br. I will present a review of previous companion searches and results from our current HST survey, which include one detection and two meaningful upper limits.

Student Engagement in the Classroom: The Impact of Classroom, Teacher, and Student Factors.

PubMed

Dykstra Steinbrenner, Jessica R; Watson, Linda R

2015-08-01

Researchers have highlighted engagement as a critical component of effective interventions for students with autism spectrum disorder (ASD), yet there is limited research related to engagement in school-age children with ASD. This descriptive study was designed to examine joint engagement and its relationship with classroom factors and student characteristics. The sample included 25 elementary and middle school students with ASD. Mixed level modeling was used to examine relationships between joint engagement and classroom factors and student characteristics. Joint engagement was significantly related to group size, use of student-directed practices, autism severity, and expressive communication skills. These findings have important implications for educational policies and practices and future research related to engagement and effective interventions for students with ASD.

Measurement and structural invariance of the US version of the Birth Satisfaction Scale-Revised (BSS-R) in a large sample.

PubMed

Martin, Colin R; Hollins Martin, Caroline J; Burduli, Ekaterina; Barbosa-Leiker, Celestina; Donovan-Batson, Colleen; Fleming, Susan E

2017-08-01

The 10-item Birth Satisfaction Scale-Revised (BSS-R) is being increasingly used internationally. The use of the measure and the concept has gathered traction in the United States following the development of a US version of the tool. A limitation of previous studies of the measurement characteristics of the BSS-R is modest sample size. Unplanned pregnancy is recognised as being associated with a range of negative birth outcomes, but the relationship to birth satisfaction has received little attention, despite the importance of birth satisfaction to a range of postnatal outcomes. The current investigation sought to evaluate the measurement characteristics of the BSS-R in a large postpartum sample. Multiple Groups Confirmatory Factor Analysis (MGCFA) was used to evaluate a series of measurement and structural models of the BSS-R to evaluate fundamental invariance characteristics using planned/unplanned pregnancy status to differentiate groups. Complete data from N=2116 women revealed that the US version of the BSS-R offers an excellent fit to data and demonstrates full measurement and structural invariance. Little difference was observed between women on the basis of planned/unplanned pregnancy stratification on measures of birth satisfaction. The established relationship between unplanned pregnancy and negative perinatal outcomes was not found to extend to birth satisfaction in the current study. The BSS-R demonstrated exemplary measurement and structural invariance characteristics. The current study strongly supports the use of the US version of the BSS-R to compare birth satisfaction across different groups of women with theoretical and measurement confidence. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Low-Temperature Aging Characteristics of Type 316L Stainless Steel Welds: Dependence on Solidification Mode

NASA Astrophysics Data System (ADS)

Abe, Hiroshi; Watanabe, Yutaka

2008-06-01

Thermal aging embrittlement of light water reactor (LWR) components made of stainless steel cast has been recognized as a potential degradation issue, and careful attention has been paid to it. Although welds of austenitic stainless steels have γ-δ duplex microstructure, which is similar to that of the stainless steel cast, examination of the thermal aging characteristics of the stainless steel welds is very limited. In this investigation, two types of type 316L stainless steel weld metal with different solidification modes were prepared using two kinds of filler metals having tailored Ni equivalent and Cr equivalent. Differences between the two weld metals in the morphology of microstructure, in the composition of δ-ferrite, and in hardening behaviors with isothermal aging at 335 °C have been investigated. The hardness of the ferrite phase has increased with aging time, while the hardness of austenite phase has stayed the same. The mottled aspect has been observed in δ-ferrite of aged samples by transmission electron microscopy (TEM) observation. These characteristics suggest that spinodal decomposition has occurred in δ-ferrite by aging at 335 °C. The age-hardening rate of δ-ferrite was faster for the primary austenite solidification mode (AF mode) sample than the primary ferrite solidification mode (FA mode) sample in the initial stage of the aging up to 2000 hours. It has been suggested that the solidification mode can affect the kinetics of spinodal decomposition.

M-H characteristics and demagnetization resistance of samarium-cobalt permanent magnets to 300 C

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1992-01-01

The influence of temperature on the M-H demagnetization characteristics of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperatures in demagnetization-resistant permanent magnet devices. In high temperature space power converters, such as free-piston Stirling engine driven linear alternators, magnet demagnetization can occur as a long-term consequence of thermal agitation of domains and of metallurgical change, and also as an immediate consequence of too large an applied field. Investigated here is the short-term demagnetization resistance to applied fields derived from basic M-H data. This quasistatic demagnetization data was obtained for commercial, high-intrinsic-coercivity, Sm2Co17-type magnets from 5 sources, in the temperature range 23 to 300 C. An electromagnet driven, electronic hysteresigraph was used to test the 1-cm cubic samples. The observed variation of the 2nd quadrant M-H characteristics was a typical rapid loss of M-coercivity and a relatively lesser loss of remanence with increasing temperature. The 2nd quadrant M-H curve knee point is used to define the limits of operation safe against irreversible demagnetization due to an excessive bucking field for a given flux density swing at temperature. Such safe operating area plots are shown to differentiate the high temperature capabilities of the samples from different sources. For most of the samples, their 2nd quadrant M-H loop squareness increased with temperature, reaching a peak or a plateau above 250 C.

Direct sampling of chemical weapons in water by photoionization mass spectrometry.

PubMed

Syage, Jack A; Cai, Sheng-Suan; Li, Jianwei; Evans, Matthew D

2006-05-01

The vulnerability of water supplies to toxic contamination calls for fast and effective means for screening water samples for multiple threats. We describe the use of photoionization (PI) mass spectrometry (MS) for high-speed, high-throughput screening and molecular identification of chemical weapons (CW) threats and other hazardous compounds. The screening technology can detect a wide range of compounds at subacute concentrations with no sample preparation and a sampling cycle time of approximately 45 s. The technology was tested with CW agents VX, GA, GB, GD, GF, HD, HN1, and HN3, in addition to riot agents and precursors. All are sensitively detected and give simple PI mass spectra dominated by the parent ion. The target application of the PI MS method is as a routine, real-time early warning system for CW agents and other hazardous compounds in air and in water. In this work, we also present comprehensive measurements for water analysis and report on the system detection limits, linearity, quantitation accuracy, and false positive (FP) and false negative rates for concentrations at subacute levels. The latter data are presented in the form of receiver operating characteristic curves of the form of detection probability P(D) versus FP probability P(FP). These measurements were made using the CW surrogate compounds, DMMP, DEMP, DEEP, and DIMP. Method detection limits (3sigma) obtained using a capillary injection method yielded 1, 6, 3, and 2 ng/mL, respectively. These results were obtained using 1-microL injections of water samples without any preparation, corresponding to mass detection limits of 1, 6, 3, and 2 pg, respectively. The linear range was about 3-4 decades and the dynamic range about 4-5 decades. The relative standard deviations were generally <10% at CW subacute concentrations levels.

Types and Characteristics of Childhood Sexual Abuse: How Do They Matter in HIV Sexual Risk Behaviors Among Women in Methadone Treatment in New York City?

PubMed

Engstrom, Malitta; Winham, Katherine; Gilbert, Louisa

2016-01-01

Childhood sexual abuse (CSA) is often considered an important distal factor in HIV sexual risk behaviors; however, there are limited and mixed findings regarding this relationship among women experiencing substance use problems. In addition, research with this population of women has yet to examine differences in observed CSA-HIV sexual risk behaviors relationships by CSA type and characteristics. This study examines relationships between CSA coding, type, and characteristics and HIV sexual risk behaviors with main intimate partners among a random sample of 390 women in methadone treatment in New York City who completed individual interviews with trained female interviewers. Findings from logistic regression analyses indicate that CSA predicts substance use with sexual activity, with variations by CSA coding, type, and characteristics; however, the role of CSA is more limited than expected. Having a main partner with HIV risk mediates some relationships between CSA and drinking four or more drinks prior to sex. Intimate partner violence is the most consistent predictor of sexual risk behaviors. Other salient factors include polysubstance use, depression, social support, recent incarceration, relationship characteristics, and HIV status. This study contributes to understanding of relationships between CSA and HIV sexual risk behaviors and key correlates associated with HIV sexual risk behaviors among women in methadone treatment. It also highlights the complexity of measuring CSA and its association with sexual risk behaviors and the importance of comprehensive approaches to HIV prevention that address psychological, relational, situational, and substance use experiences associated with sexual risk behaviors among this population.

The effect of bronchodilators on forced vital capacity measurement in patients with idiopathic pulmonary fibrosis

PubMed Central

Assayag, Deborah; Vittinghoff, Eric; Ryerson, Christopher J.; Cocconcelli, Elisabetta; Tonelli, Roberto; Hu, Xiaowen; Elicker, Brett M.; Golden, Jeffrey A.; Jones, Kirk D.; King, Talmadge E.; Koth, Laura L.; Lee, Joyce S.; Ley, Brett; Shum, Anthony K.; Wolters, Paul J.; Ryu, Jay H.; Collard, Harold R.

2015-01-01

Background Forced vital capacity (FVC) is a key measure of disease severity in patients with idiopathic pulmonary fibrosis (IPF) and is an important clinical trial endpoint. We hypothesize that reversible airflow limitation co-exists in a subgroup of patients with IPF, and that bronchodilator use will improve the performance characteristics of FVC. Methods IPF patients with pre and post-bronchodilator spirometry testing performed were identified from two tertiary referral cohorts. The difference between pre and post-bronchodilator FVC (intra-test difference) was calculated. The test characteristics of pre and post-bronchodilator FVC change over time (inter-test difference) were assessed in patients with sequential spirometry, and were used to generate sample size estimates for hypothetical clinical trials using change in FVC as the primary endpoint. Results There were 551 patients, contributing 967 unique spirometry tests. The mean intra-test increase in FVC with bronchodilator use was 0.04 liters (2.71 vs. 2.75 liters, p <0.001). Reversible airflow limitation (increase in FEV1 or FVC of ≥12% and ≥200 milliliters) occurred in 9.1% of patients. The inter-test difference in change in FVC over time were equivalent for pre and post-bronchodilator (p = 0.65), leading to similar sample size estimates in a hypothetical clinical trial using change in FVC as the primary endpoint. Conclusion Approximately one in ten patients with IPF has physiological evidence of reversible airflow limitation, and bronchodilator use in these patients may improve the assessment of disease progression based on FVC change over time. Bronchodilator use does not appear to meaningfully impact the precision of FVC as an endpoint in clinical trials. PMID:26140806

Psychometric properties of the Portuguese version of the Acceptance and Action Questionnaire-Trauma Specific (AAQ-TS): A study with Portuguese Colonial War Veterans.

PubMed

Pinto-Gouveia, José; Carvalho, Teresa; Cunha, Marina; Duarte, Joana; Walser, Robyn D

2015-10-01

The Acceptance and Action Questionnaire-Trauma Specific (AAQ-TS) is a self-report measure designed to assess-trauma-related psychological (in)flexibility, as conceptualized in Acceptance and Commitment Therapy. However, there are no studies to date regarding its psychometric properties. This study explores such properties in the Portuguese version of the AAQ-TS, in Portuguese Colonial War Veterans. A Principal Components Analysis (PCA) was conducted in a sample from the general population of war Veterans (N=371). Confirmatory Factor Analysis (CFA) as well as reliability and convergent validity studies were performed in a different sample from the same population (N=312). For the discriminant validity a clinical sample with a war-related PTSD (N=42) and a non-clinical sample without PTSD (N=44) were used. The CFA suggested a re-specified 15-item model with good global adjustment and factorial validity. The AAQ-TS showed internal consistency, a good temporal reliability, convergent validity with psychopathological symptoms (related to PTSD, anxiety, depression and stress) and peritraumatic dissociation (altered awareness and depersonalization/derealization). The questionnaire also discriminates between war Veterans with and without a PTSD diagnosis. The major limitation relates to the samples' characteristics and sampling methods, which can limit the generalization of results. The Portuguese version of the AAQ-TS is a reliable and valid measure to assess experiential avoidance related to trauma in Portuguese Colonial War Veterans. Copyright © 2015 Elsevier B.V. All rights reserved.

Hydro-geochemistry and application of water quality index (WQI) for groundwater quality assessment, Anna Nagar, part of Chennai City, Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Krishna kumar, S.; Logeshkumaran, A.; Magesh, N. S.; Godson, Prince S.; Chandrasekar, N.

2015-12-01

In the present study, the geochemical characteristics of groundwater and drinking water quality has been studied. 24 groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, carbonate, bicarbonate, chloride, sulphate, nitrate, calcium, magnesium, sodium, potassium and total hardness. The results were evaluated and compared with WHO and BIS water quality standards. The studied results reveal that the groundwater is fresh to brackish and moderately high to hard in nature. Na and Cl are dominant ions among cations and anions. Chloride, calcium and magnesium ions are within the allowable limit except few samples. According to Gibbs diagram, the predominant samples fall in the rock-water interaction dominance and evaporation dominance field. The piper trilinear diagram shows that groundwater samples are Na-Cl and mixed CaMgCl type. Based on the WQI results majority of the samples are falling under excellent to good category and suitable for drinking water purposes.

Identification of usual interstitial pneumonia pattern using RNA-Seq and machine learning: challenges and solutions.

PubMed

Choi, Yoonha; Liu, Tiffany Ting; Pankratz, Daniel G; Colby, Thomas V; Barth, Neil M; Lynch, David A; Walsh, P Sean; Raghu, Ganesh; Kennedy, Giulia C; Huang, Jing

2018-05-09

We developed a classifier using RNA sequencing data that identifies the usual interstitial pneumonia (UIP) pattern for the diagnosis of idiopathic pulmonary fibrosis. We addressed significant challenges, including limited sample size, biological and technical sample heterogeneity, and reagent and assay batch effects. We identified inter- and intra-patient heterogeneity, particularly within the non-UIP group. The models classified UIP on transbronchial biopsy samples with a receiver-operating characteristic area under the curve of ~ 0.9 in cross-validation. Using in silico mixed samples in training, we prospectively defined a decision boundary to optimize specificity at ≥85%. The penalized logistic regression model showed greater reproducibility across technical replicates and was chosen as the final model. The final model showed sensitivity of 70% and specificity of 88% in the test set. We demonstrated that the suggested methodologies appropriately addressed challenges of the sample size, disease heterogeneity and technical batch effects and developed a highly accurate and robust classifier leveraging RNA sequencing for the classification of UIP.

Dissolved pesticides, dissolved organic carbon, and water-quality characteristics in selected Idaho streams, April--December 2010

USGS Publications Warehouse

Reilly, Timothy J.; Smalling, Kelly L.; Wilson, Emma R.; Battaglin, William A.

2012-01-01

Water-quality samples were collected from April through December 2010 from four streams in Idaho and analyzed for a suite of pesticides, including fungicides, by the U.S. Geological Survey. Water samples were collected from two agricultural and two nonagricultural (control) streams approximately biweekly from the beginning of the growing season (April) through the end of the calendar year (December). Samples were analyzed for 90 pesticides using gas chromatography/mass spectrometry. Twenty-three pesticides, including 8 fungicides, 10 herbicides, 3 insecticides, and 2 pesticide degradates, were detected in 45 water samples. The most frequently detected compounds in the two agricultural streams and their detection frequencies were metolachlor, 96 percent; azoxystrobin, 79 percent; boscalid, 79 percent; atrazine, 46 percent; pendimethalin, 33 percent; and trifluralin, 33 percent. Dissolved-pesticide concentrations ranged from below instrumental limits of detection (0.5-1.0 nanograms per liter) to 771 nanograms per liter (hexazinone). The total number of pesticides detected in any given water sample ranged from 0 to 11. Only three pesticides (atrazine, fipronil, and simazine) were detected in samples from the control streams during the sampling period.

Solid sampling determination of total fluorine in baby food samples by high-resolution continuum source graphite furnace molecular absorption spectrometry.

PubMed

Ozbek, Nil; Akman, Suleyman

2016-11-15

This study describes the applicability of solid sampling technique for the determination of fluorine in various baby foods via molecular absorption of calcium monofluoride generated in a graphite furnace of high-resolution continuum source atomic absorption spectrometry. Fluorine was determined at CaF wavelength, 606.440nm in a graphite tube applying a pyrolysis temperature of 1000°C and a molecule forming temperature of 2200°C. The limit of detection and characteristic mass of the method were 0.20ng and 0.17ng of fluorine, respectively. The fluorine concentrations determined in standard reference sample (bush branches and leaves) were in good agreement with the certified values. By applying the optimized parameters, the concentration of fluorine in various baby foods were determined. The fluorine concentrations were ranged from

Sparse-sampling with time-encoded (TICO) stimulated Raman scattering for fast image acquisition

NASA Astrophysics Data System (ADS)

Hakert, Hubertus; Eibl, Matthias; Karpf, Sebastian; Huber, Robert

2017-07-01

Modern biomedical imaging modalities aim to provide researchers a multimodal contrast for a deeper insight into a specimen under investigation. A very promising technique is stimulated Raman scattering (SRS) microscopy, which can unveil the chemical composition of a sample with a very high specificity. Although the signal intensities are enhanced manifold to achieve a faster acquisition of images if compared to standard Raman microscopy, there is a trade-off between specificity and acquisition speed. Commonly used SRS concepts either probe only very few Raman transitions as the tuning of the applied laser sources is complicated or record whole spectra with a spectrometer based setup. While the first approach is fast, it reduces the specificity and the spectrometer approach records whole spectra -with energy differences where no Raman information is present-, which limits the acquisition speed. Therefore, we present a new approach based on the TICO-Raman concept, which we call sparse-sampling. The TICO-sparse-sampling setup is fully electronically controllable and allows probing of only the characteristic peaks of a Raman spectrum instead of always acquiring a whole spectrum. By reducing the spectral points to the relevant peaks, the acquisition time can be greatly reduced compared to a uniformly, equidistantly sampled Raman spectrum while the specificity and the signal to noise ratio (SNR) are maintained. Furthermore, all laser sources are completely fiber based. The synchronized detection enables a full resolution of the Raman signal, whereas the analogue and digital balancing allows shot noise limited detection. First imaging results with polystyrene (PS) and polymethylmethacrylate (PMMA) beads confirm the advantages of TICO sparse-sampling. We achieved a pixel dwell time as low as 35 μs for an image differentiating both species. The mechanical properties of the applied voice coil stage for scanning the sample currently limits even faster acquisition.

Lab on a Chip

NASA Astrophysics Data System (ADS)

Puget, P.

The reliable and fast detection of chemical or biological molecules, or the measurement of their concentrations in a sample, are key problems in many fields such as environmental analysis, medical diagnosis, or the food industry. There are traditionally two approaches to this problem. The first aims to carry out a measurement in situ in the sample using chemical and biological sensors. The constraints imposed by detection limits, specificity, and in some cases stability are entirely imputed to the sensor. The second approach uses so-called total analysis systems to process the sample according to a protocol made up of different steps, such as extractions, purifications, concentrations, and a final detection stage. The latter is made in better conditions than with the first approach, which may justify the greater complexity of the process. It is this approach that is implemented in most methods for identifying pathogens, whether they be in biological samples (especially for in vitro diagnosis) or samples taken from the environment. The instrumentation traditionally used to carry out these protocols comprises a set of bulky benchtop apparatus, which needs to be plugged into the mains in order to function. However, there are many specific applications (to be discussed in this chapter) for which analysis instruments with the following characteristics are needed: Possibility of use outside the laboratory, i.e., instruments as small as possible, consuming little energy, and largely insensitive to external conditions of temperature, humidity, vibrations, and so on. Possibility of use by non-specialised agents, or even unmanned operation. Possibility of handling a large number of samples in a limited time, typically for high-throughput screening applications. Possibility of handling small samples. At the same time, a high level of performance is required, in particular in terms of (1) the detection limit, which must be as low as possible, (2) specificity, i.e., the ability to detect a particular molecule in a complex mixture, and (3) speed.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

USGS Publications Warehouse

Zaugg, Steven D.; Sandstrom, Mark W.; Smith, Steven G.; Fehlberg, Kevin M.

1995-01-01

A method for the isolation of 41 pesticides and pesticide metabolites in natural-water samples using C-18 solid-phase extraction and determination by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction columns containing octadecyl-bonded porous silica to extract the pesticides. The columns are dried using carbon dioxide or nitrogen gas, and adsorbed pesticides are removed from the columns by elution with 3.0 milliliters of hexane-isopropanol (3:1). Extracted pesticides are determined by capillary- column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 4 micrograms per liter (g/L) for most pesticides, with the exception of widely used corn herbicides--atrazine, alachlor, cyanazine, and metolachlor--which have upper concentration limits of 20 g/L. Single- operator method detection limits in reagent-water samples range from 0.001 to 0.018 g/L. Average short-term single-operator precision in reagent- water samples is 7 percent at the 0.1- and 1.0-g/L levels and 8 percent at the 0.01-g/L level. Mean recoveries in reagent-water samples are 73 percent at the 0.1- and 1.0-g/L levels and 83 percent at the 0.01-g/L level. The estimated holding time for pesticides after extraction on the solid-phase extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time.

Approaches to Recruiting 'Hard-To-Reach' Populations into Re-search: A Review of the Literature.

PubMed

Shaghaghi, Abdolreza; Bhopal, Raj S; Sheikh, Aziz

2011-01-01

'Hard-to-reach' is a term used to describe those sub-groups of the population that may be difficult to reach or involve in research or public health programmes. Application of a single term to call these sub-sections of populations implies a homogeneity within distinct groups, which does not necessarily exist. Different sampling techniques were introduced so far to recruit hard-to-reach populations. In this article, we have reviewed a range of ap-proaches that have been used to widen participation in studies. We performed a Pubmed and Google search for relevant English language articles using the keywords and phrases: (hard-to-reach AND population* OR sampl*), (hidden AND population* OR sample*) and ("hard to reach" AND population* OR sample*) and a consul-tation of the retrieved articles' bibliographies to extract empirical evidence from publications that discussed or examined the use of sampling techniques to recruit hidden or hard-to-reach populations in health studies. Reviewing the literature has identified a range of techniques to recruit hard-to-reach populations, including snowball sampling, respondent-driven sampling (RDS), indigenous field worker sampling (IFWS), facility-based sampling (FBS), targeted sampling (TS), time-location (space) sampling (TLS), conventional cluster sampling (CCS) and capture re-capture sampling (CR). The degree of compliance with a study by a certain 'hard-to-reach' group de-pends on the characteristics of that group, recruitment technique used and the subject of inter-est. Irrespective of potential advantages or limitations of the recruitment techniques reviewed, their successful use depends mainly upon our knowledge about specific characteristics of the target populations. Thus in line with attempts to expand the current boundaries of our know-ledge about recruitment techniques in health studies and their applications in varying situa-tions, we should also focus on possibly all contributing factors which may have an impact on participation rate within a defined population group.

Ignition and Combustion Characteristics of Nanoscale Al/AgIO3: A Potential Energetic Biocidal System

DTIC Science & Technology

2011-01-01

the actual particle morphology consists of thin platelets , roughly 1 mm in diam- eter. Silver iodide was purchased from Sigma Aldrich, and the size was...2008), and shows that mixing is limited by clumping of both ingredients. The AgIO3 has a platelet -like morphology, and could potentially mix...in this study is 80 nm from NanoTechnologies. The CuO in this study is 45 nm from Technanogy. Each sample was fuel rich in this study with equivalency

Observations of Nonthermal Radio Emission from Early-type Stars

NASA Technical Reports Server (NTRS)

Abbott, D. C.; Bieging, J. H.; Churchwell, E.

1985-01-01

As a part of a wider survey of radio emission from O, B, and Wolf-Rayet (WR) stars, five new stars whose radio emission is dominated by a nonthermal mechanism of unknown origin were discovered. From statistics of distance-limited samples of stars, it is estimated that the minimum fraction of stars which are nonthermal emitters is 25% for the OB stars and 10% for the WR stars. The characteristics of this new class of nonthermal radio emitter are investigated.

Characterization of crust formation on a parent body of achondrites and the moon by pyroxene crystallography and chemistry

NASA Technical Reports Server (NTRS)

Takeda, H.; Miyamoto, M.; Ishii, T.; Reid, A. M.

1976-01-01

Single crystal X-ray diffraction and electron microprobe techniques were used to study lunar crustal pyroxenes in a cataclastic norite, a pyroxene-rich clast, and anorthosite lunar samples, and also in meteorites including diogenites, eucrites, and the Yamoto (1) howardite. The crystallographic and chemical characteristics of pyroxenes in these materials are compared and are discussed in terms of the lower stability limit of pigeonite. A mechanical mixing model of howardite is proposed.

Brain tumor detection and segmentation in a CRF (conditional random fields) framework with pixel-pairwise affinity and superpixel-level features.

PubMed

Wu, Wei; Chen, Albert Y C; Zhao, Liang; Corso, Jason J

2014-03-01

Detection and segmentation of a brain tumor such as glioblastoma multiforme (GBM) in magnetic resonance (MR) images are often challenging due to its intrinsically heterogeneous signal characteristics. A robust segmentation method for brain tumor MRI scans was developed and tested. Simple thresholds and statistical methods are unable to adequately segment the various elements of the GBM, such as local contrast enhancement, necrosis, and edema. Most voxel-based methods cannot achieve satisfactory results in larger data sets, and the methods based on generative or discriminative models have intrinsic limitations during application, such as small sample set learning and transfer. A new method was developed to overcome these challenges. Multimodal MR images are segmented into superpixels using algorithms to alleviate the sampling issue and to improve the sample representativeness. Next, features were extracted from the superpixels using multi-level Gabor wavelet filters. Based on the features, a support vector machine (SVM) model and an affinity metric model for tumors were trained to overcome the limitations of previous generative models. Based on the output of the SVM and spatial affinity models, conditional random fields theory was applied to segment the tumor in a maximum a posteriori fashion given the smoothness prior defined by our affinity model. Finally, labeling noise was removed using "structural knowledge" such as the symmetrical and continuous characteristics of the tumor in spatial domain. The system was evaluated with 20 GBM cases and the BraTS challenge data set. Dice coefficients were computed, and the results were highly consistent with those reported by Zikic et al. (MICCAI 2012, Lecture notes in computer science. vol 7512, pp 369-376, 2012). A brain tumor segmentation method using model-aware affinity demonstrates comparable performance with other state-of-the art algorithms.

Effectiveness of IT-based diabetes management interventions: a review of the literature.

PubMed

Costa, Beth M; Fitzgerald, Kristine J; Jones, Kay M; Dunning Am, Trisha

2009-11-17

Information technology (IT) is increasingly being used in general practice to manage health care including type 2 diabetes. However, there is conflicting evidence about whether IT improves diabetes outcomes. This review of the literature about IT-based diabetes management interventions explores whether methodological issues such as sample characteristics, outcome measures, and mechanisms causing change in the outcome measures could explain some of the inconsistent findings evident in IT-based diabetes management studies. Databases were searched using terms related to IT and diabetes management. Articles eligible for review evaluated an IT-based diabetes management intervention in general practice and were published between 1999 and 2009 inclusive in English. Studies that did not include outcome measures were excluded. Four hundred and twenty-five articles were identified, sixteen met the inclusion criteria: eleven GP focussed and five patient focused interventions were evaluated. Nine were RCTs, five non-randomised control trials, and two single-sample before and after designs. Important sample characteristics such as diabetes type, familiarity with IT, and baseline diabetes knowledge were not addressed in any of the studies reviewed. All studies used HbA1c as a primary outcome measure, and nine reported a significant improvement in mean HbA1c over the study period; only two studies reported the HbA1c assay method. Five studies measured diabetes medications and two measured psychological outcomes. Patient lifestyle variables were not included in any of the studies reviewed. IT was the intervention method considered to effect changes in the outcome measures. Only two studies mentioned alternative possible causal mechanisms. Several limitations could affect the outcomes of IT-based diabetes management interventions to an unknown degree. These limitations make it difficult to attribute changes solely to such interventions.

Characteristics of polycyclic aromatic hydrocarbons in food oils in Beijing catering services.

PubMed

Hao, Xuewei; Yin, Yong; Feng, Sijie; Du, Xu; Yu, Jingyi; Yao, Zhiliang

2016-12-01

The concentrations and characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in 48 oil samples randomly collected from 30 catering services that employ six cooking methods were quantified via high-performance liquid chromatography (HPLC). These 16 PAHs were detected in almost all of the samples. The levels of Σ16PAHs, Σ4PAHs, benzo[a]pyrene (BaP), and total BaP equivalents (ΣBaP eq ) for the six cooking methods exceeded the legal limit. The concentrations of Σ4PAHs were approximately 9.5 to 16.4 times the legal limit proposed by the European Commission (Off J Eur Union 215:4-8, 2011), and the level of BaP exceeded the national standard in China by 4.7- to 10.6-fold, particularly in oil from fried foods. Low molecular weight PAHs (LMW PAHs) were predominant in fried food oil from different catering services and accounted for 94.8 % of these oils, and the ΣBaP eq of the high molecular weight PAHs (HMW PAHs) was 11.5-fold higher than that of the LMW PAHs. The concentrations of Σ16PAHs (3751.9-7585.8 μg/kg), Σ4PAHs (144.6-195.7 μg/kg), BaP (79.7-135.8 μg/kg), and ΣBaP eq (231.0-265.4 μg/kg) were highest in the samples from fast food restaurants/buffets (FB), followed by those from fried food stalls (FS) and then cooking restaurants/cafeterias (RC). The results of this study suggest that the government should strengthen control and supervision of PAH contamination in food and edible oils.

Value of lower respiratory tract surveillance cultures to predict bacterial pathogens in ventilator-associated pneumonia: systematic review and diagnostic test accuracy meta-analysis.

PubMed

Brusselaers, Nele; Labeau, Sonia; Vogelaers, Dirk; Blot, Stijn

2013-03-01

In ventilator-associated pneumonia (VAP), early appropriate antimicrobial therapy may be hampered by involvement of multidrug-resistant (MDR) pathogens. A systematic review and diagnostic test accuracy meta-analysis were performed to analyse whether lower respiratory tract surveillance cultures accurately predict the causative pathogens of subsequent VAP in adult patients. Selection and assessment of eligibility were performed by three investigators by mutual consideration. Of the 525 studies retrieved, 14 were eligible for inclusion (all in English; published since 1994), accounting for 791 VAP episodes. The following data were collected: study and population characteristics; in- and exclusion criteria; diagnostic criteria for VAP; microbiological workup of surveillance and diagnostic VAP cultures. Sub-analyses were conducted for VAP caused by Staphylococcus aureus, Pseudomonas spp., and Acinetobacter spp., MDR microorganisms, frequency of sampling, and consideration of all versus the most recent surveillance cultures. The meta-analysis showed a high accuracy of surveillance cultures, with pooled sensitivities up to 0.75 and specificities up to 0.92 in culture-positive VAP. The area under the curve (AUC) of the hierarchical summary receiver-operating characteristic curve demonstrates moderate accuracy (AUC: 0.90) in predicting multidrug resistance. A sampling frequency of >2/week (sensitivity 0.79; specificity 0.96) and consideration of only the most recent surveillance culture (sensitivity 0.78; specificity 0.96) are associated with a higher accuracy of prediction. This study provides evidence for the benefit of surveillance cultures in predicting MDR bacterial pathogens in VAP. However, clinical and statistical heterogeneity, limited samples sizes, and bias remain important limitations of this meta-analysis.

Determination of arsenic and selenium by hydride generation and headspace solid phase microextraction coupled with optical emission spectrometry

NASA Astrophysics Data System (ADS)

Tyburska, Anna; Jankowski, Krzysztof; Rodzik, Agnieszka

2011-07-01

A hydride generation headspace solid phase microextraction technique has been developed in combination with optical emission spectrometry for determination of total arsenic and selenium. Hydrides were generated in a 10 mL volume septum-sealed vial and subsequently collected onto a polydimethylsiloxane/Carboxen solid phase microextraction fiber from the headspace of sample solution. After completion of the sorption, the fiber was transferred into a thermal desorption unit and the analytes were vaporized and directly introduced into argon inductively coupled plasma or helium microwave induced plasma radiation source. Experimental conditions of hydride formation reaction as well as sorption and desorption of analytes have been optimized showing the significant effect of the type of the solid phase microextraction fiber coating, the sorption time and hydrochloric acid concentration of the sample solution on analytical characteristics of the method developed. The limits of detection of arsenic and selenium were 0.1 and 0.8 ng mL - 1 , respectively. The limit of detection of selenium could be improved further using biosorption with baker's yeast Saccharomyces cerevisiae for analyte preconcentration. The technique was applied for the determination of total As and Se in real samples.

Smart Sampling and HPC-based Probabilistic Look-ahead Contingency Analysis Implementation and its Evaluation with Real-world Data

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

Chen, Yousu; Etingov, Pavel V.; Ren, Huiying

This paper describes a probabilistic look-ahead contingency analysis application that incorporates smart sampling and high-performance computing (HPC) techniques. Smart sampling techniques are implemented to effectively represent the structure and statistical characteristics of uncertainty introduced by different sources in the power system. They can significantly reduce the data set size required for multiple look-ahead contingency analyses, and therefore reduce the time required to compute them. High-performance-computing (HPC) techniques are used to further reduce computational time. These two techniques enable a predictive capability that forecasts the impact of various uncertainties on potential transmission limit violations. The developed package has been tested withmore » real world data from the Bonneville Power Administration. Case study results are presented to demonstrate the performance of the applications developed.« less

Determination of Low Concentrations of Acetochlor in Water by Automated Solid-Phase Extraction and Gas Chromatography with Mass-Selective Detection

USGS Publications Warehouse

Lindley, C.E.; Stewart, J.T.; Sandstrom, M.W.

1996-01-01

A sensitive and reliable gas chromatographic/mass spectrometric (GC/MS) method for determining acetochlor in environmental water samples was developed. The method involves automated extraction of the herbicide from a filtered 1 L water sample through a C18 solid-phase extraction column, elution from the column with hexane-isopropyl alcohol (3 + 1), and concentration of the extract with nitrogen gas. The herbicide is quantitated by capillary/column GC/MS with selected-ion monitoring of 3 characteristic ions. The single-operator method detection limit for reagent water samples is 0.0015 ??g/L. Mean recoveries ranged from about 92 to 115% for 3 water matrixes fortified at 0.05 and 0.5 ??g/L. Average single-operator precision, over the course of 1 week, was better than 5%.

Prevalence, characteristics and correlates of enteric pathogenic protozoa in drinking water sources in Molyko and Bomaka, Cameroon: a cross-sectional study.

PubMed

Nsoh, Fuh Anold; Wung, Buh Amos; Atashili, Julius; Benjamin, Pokam Thumamo; Marvlyn, Eba; Ivo, Keumami Katte; Nguedia, Assob Jules Clément

2016-11-08

Access to potable water remains a major challenge particularly in resource-limited settings. Although the potential contaminants of water are varied, enteric pathogenic protozoa are known to cause waterborne diseases greatly. This study aimed at investigating the prevalence, characteristics and correlates of enteric pathogenic protozoa in drinking water sources in Buea, Cameroon. A cross-sectional study was conducted using 155 water samples collected from various drinking sources (boreholes, springs, taps and wells). Each sample was subjected to physicochemical examinations (pH, turbidity, odour and sliminess) and parasitological analysis (wet mount, modified Ziehl-Neelsen stain) to determine the presence of enteric pathogenic protozoa. A data collection tool was used to note characteristics of collected samples and the data was analysed using EPI-INFO Version 3.5.3. The overall prevalence of enteric pathogenic protozoa in water sources was 62.6 %. Eight species of enteric protozoa were observed with Cryptosporidium parvum being the most predominant (45.8 %). Spring water was the most contaminated source with enteric protozoa (85.7 %) while pipe borne water had all eight species of protozoa identified. A pH of 6 was the only significant factor associated with the prevalence of these pathogens in water sources. The prevalence of enteric protozoa in water sources in Molyko and Bomaka is high, spring water is the most contaminated water source and Cryptosporidium parvum is the most common protozoa contaminating water. A water pH of 6 is associated to the prevalence of protozoa. Community members need to be educated to treat water before drinking to avoid infection by enteric protozoa in water and further studies with larger samples of water need to be conducted to find other correlates of the presence of protozoa in water.

Normative morphometric data for cerebral cortical areas over the lifetime of the adult human brain.

PubMed

Potvin, Olivier; Dieumegarde, Louis; Duchesne, Simon

2017-08-01

Proper normative data of anatomical measurements of cortical regions, allowing to quantify brain abnormalities, are lacking. We developed norms for regional cortical surface areas, thicknesses, and volumes based on cross-sectional MRI scans from 2713 healthy individuals aged 18 to 94 years using 23 samples provided by 21 independent research groups. The segmentation was conducted using FreeSurfer, a widely used and freely available automated segmentation software. Models predicting regional cortical estimates of each hemisphere were produced using age, sex, estimated total intracranial volume (eTIV), scanner manufacturer, magnetic field strength, and interactions as predictors. The explained variance for the left/right cortex was 76%/76% for surface area, 43%/42% for thickness, and 80%/80% for volume. The mean explained variance for all regions was 41% for surface areas, 27% for thicknesses, and 46% for volumes. Age, sex and eTIV predicted most of the explained variance for surface areas and volumes while age was the main predictors for thicknesses. Scanner characteristics generally predicted a limited amount of variance, but this effect was stronger for thicknesses than surface areas and volumes. For new individuals, estimates of their expected surface area, thickness and volume based on their characteristics and the scanner characteristics can be obtained using the derived formulas, as well as Z score effect sizes denoting the extent of the deviation from the normative sample. Models predicting normative values were validated in independent samples of healthy adults, showing satisfactory validation R 2 . Deviations from the normative sample were measured in individuals with mild Alzheimer's disease and schizophrenia and expected patterns of deviations were observed. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Determination of metals in lubricating oils by flame atomic absorption spectrometry using a single-bore high-pressure pneumatic nebulizer.

PubMed

Mora, J; Todolí, J L; Sempere, F J; Canals, A; Hernandis, V

2000-12-01

The behaviour of a single-bore high-pressure pneumatic nebulizer (SBHPPN) as a tool for the analysis of lubricating oils by flame atomic absorption spectrometry (FAAS) was investigated. The effects of the sample oil content [from 10% to 100% (w/w) oil in 4-methylpentan-2-one, IBMK] and the carrier nature (IBMK and methanol) on the characteristics of the aerosols generated, on the analyte transport efficiency and on the analytical figures of merit in FAAS were studied. A pneumatic concentric nebulizer (PCN) was used for comparison. Increasing the oil content increases the viscosity of the sample. With the PCN this gives rise to coarser aerosols, making it impossible to nebulize samples with an oil content higher than 70% (w/w). Using the SBHPPN, the viscosity of the sample scarcely affects the characteristics of the primary aerosols. Hence, the SBHPPN is able, by using the appropriate carrier, to nebulize pure lubricating oils. Among the carriers tested, IBMK is the most advisable because it is fully miscible with all the oil samples. The SBHPPN provides higher sensitivities and lower limits of detection than the PCN. Compared with a method based on organic dilution, the use of the SBHPPN for the direct analysis of lubricating oils by FAAS makes it possible, in addition to increasing the analysis throughput, to detect elements at lower concentrations. Moreover, the SBHPPN provides similar results to those obtained using a previous acid digestion step.

Occurrence of Brettanomyces/Dekkera in Brazilian red wines and its correlation with ethylphenols

PubMed Central

de Ávila, Larissa Dias; Ayub, Marco Antônio Záchia

2013-01-01

The yeast Brettanomyces/Dekkera can cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanomyces/Dekkera were quantified by plating 126 samples of dry red wine in selective culture medium, while ethylphenols were analyzed by solid phase extraction and GC/FID. Free and total SO2, alcohol, total dry extract, residual sugar, total and volatile acidity, and pH were also determined. Brettanomyces/Dekkera was present in 27% of samples. Ethylphenols were detected in most samples, with amounts higher than the threshold limit of 426 μg/L found in 46.03% of samples. The majority of wine samples showed inadequate levels of SO2 and residual sugars, facts that might facilitate microbial spoilage. The passage in barrels and the grape varieties (Cabernet Sauvignon and Merlot), did not show any influence on the levels of contamination or ethylphenols contents. The prevalence of Brettanomyces/Dekkera and the concentrations of ethylphenols were high considering the sensory impact they can cause. The growth of Brettanomyces/Dekkera was dependent on the levels of SO2 and alcohol of wines. Knowledge of the contamination, the presence of ethylphenols, and their relationship with the chemical characteristics of wines can entice effective measures to prevent Brettanomyces/Dekkera and contribute to improve the general quality of Brazilian red wines. PMID:24159287

Occurrence of Brettanomyces/Dekkera in Brazilian red wines and its correlation with ethylphenols.

PubMed

de Ávila, Larissa Dias; Ayub, Marco Antônio Záchia

2013-01-01

The yeast Brettanomyces/Dekkera can cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanomyces/Dekkera were quantified by plating 126 samples of dry red wine in selective culture medium, while ethylphenols were analyzed by solid phase extraction and GC/FID. Free and total SO2, alcohol, total dry extract, residual sugar, total and volatile acidity, and pH were also determined. Brettanomyces/Dekkera was present in 27% of samples. Ethylphenols were detected in most samples, with amounts higher than the threshold limit of 426 μg/L found in 46.03% of samples. The majority of wine samples showed inadequate levels of SO2 and residual sugars, facts that might facilitate microbial spoilage. The passage in barrels and the grape varieties (Cabernet Sauvignon and Merlot), did not show any influence on the levels of contamination or ethylphenols contents. The prevalence of Brettanomyces/Dekkera and the concentrations of ethylphenols were high considering the sensory impact they can cause. The growth of Brettanomyces/Dekkera was dependent on the levels of SO2 and alcohol of wines. Knowledge of the contamination, the presence of ethylphenols, and their relationship with the chemical characteristics of wines can entice effective measures to prevent Brettanomyces/Dekkera and contribute to improve the general quality of Brazilian red wines.

Autoverification process improvement by Six Sigma approach: Clinical chemistry & immunoassay.

PubMed

Randell, Edward W; Short, Garry; Lee, Natasha; Beresford, Allison; Spencer, Margaret; Kennell, Marina; Moores, Zoë; Parry, David

2018-05-01

This study examines effectiveness of a project to enhance an autoverification (AV) system through application of Six Sigma (DMAIC) process improvement strategies. Similar AV systems set up at three sites underwent examination and modification to produce improved systems while monitoring proportions of samples autoverified, the time required for manual review and verification, sample processing time, and examining characteristics of tests not autoverified. This information was used to identify areas for improvement and monitor the impact of changes. Use of reference range based criteria had the greatest impact on the proportion of tests autoverified. To improve AV process, reference range based criteria was replaced with extreme value limits based on a 99.5% test result interval, delta check criteria were broadened, and new specimen consistency rules were implemented. Decision guidance tools were also developed to assist staff using the AV system. The mean proportion of tests and samples autoverified improved from <62% for samples and <80% for tests, to >90% for samples and >95% for tests across all three sites. The new AV system significantly decreased turn-around time and total sample review time (to about a third), however, time spent for manual review of held samples almost tripled. There was no evidence of compromise to the quality of testing process and <1% of samples held for exceeding delta check or extreme limits required corrective action. The Six Sigma (DMAIC) process improvement methodology was successfully applied to AV systems resulting in an increase in overall test and sample AV by >90%, improved turn-around time, reduced time for manual verification, and with no obvious compromise to quality or error detection. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

MMPI-2 Symptom Validity (FBS) Scale: psychometric characteristics and limitations in a Veterans Affairs neuropsychological setting.

PubMed

Gass, Carlton S; Odland, Anthony P

2014-01-01

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Symptom Validity (Fake Bad Scale [FBS]) Scale is widely used to assist in determining noncredible symptom reporting, despite a paucity of detailed research regarding its itemmetric characteristics. Originally designed for use in civil litigation, the FBS is often used in a variety of clinical settings. The present study explored its fundamental psychometric characteristics in a sample of 303 patients who were consecutively referred for a comprehensive examination in a Veterans Affairs (VA) neuropsychology clinic. FBS internal consistency (reliability) was .77. Its underlying factor structure consisted of three unitary dimensions (Tiredness/Distractibility, Stomach/Head Discomfort, and Claimed Virtue of Self/Others) accounting for 28.5% of the total variance. The FBS's internal structure showed factoral discordance, as Claimed Virtue was negatively related to most of the FBS and to its somatic complaint components. Scores on this 12-item FBS component reflected a denial of socially undesirable attitudes and behaviors (Antisocial Practices Scale) that is commonly expressed by the 1,138 males in the MMPI-2 normative sample. These 12 items significantly reduced FBS reliability, introducing systematic error variance. In this VA neuropsychological referral setting, scores on the FBS have ambiguous meaning because of its structural discordance.

U.S. consumer demand for restaurant calorie information: targeting demographic and behavioral segments in labeling initiatives.

PubMed

Kolodinsky, Jane; Reynolds, Travis William; Cannella, Mark; Timmons, David; Bromberg, Daniel

2009-01-01

To identify different segments of U.S. consumers based on food choices, exercise patterns, and desire for restaurant calorie labeling. Using a stratified (by region) random sample of the U.S. population, trained interviewers collected data for this cross-sectional study through telephone surveys. Center for Rural Studies U.S. national health survey. The final sample included 580 responses (22% response rate); data were weighted to be representative of age and gender characteristics of the U.S. population. Self-reported behaviors related to food choices, exercise patterns, desire for calorie information in restaurants, and sample demographics. Clusters were identified using Schwartz Bayesian criteria. Impacts of demographic characteristics on cluster membership were analyzed using bivariate tests of association and multinomial logit regression. Cluster analysis revealed three clusters based on respondents' food choices, activity levels, and desire for restaurant labeling. Two clusters, comprising three quarters of the sample, desired calorie labeling in restaurants. The remaining cluster opposed restaurant labeling. Demographic variables significantly predicting cluster membership included region of residence (p < .10), income (p < .05), gender (p < .01), and age (p < .10). Though limited by a low response and potential self-reporting bias in the phone survey, this study suggests that several groups are likely to benefit from restaurant calorie labeling. Specific demographic clusters could be targeted through labeling initiatives.

Preparation of magnetic molecularly imprinted polymers by atom transfer radical polymerization for the rapid extraction of avermectin from fish samples.

PubMed

You, Xiaoxiao; Gao, Lei; Qin, Dongli; Chen, Ligang

2017-01-01

A novel and highly efficient approach to obtain magnetic molecularly imprinted polymers is described to detect avermectin in fish samples. The magnetic molecularly imprinted polymers were synthesized by surface imprinting polymerization using magnetic multiwalled carbon nanotubes as the support materials, atom transfer radical polymerization as the polymerization method, avermectin as template, acrylamide as functional monomer, and ethylene glycol dimethacrylate as crosslinker. The characteristics of the magnetic molecularly imprinted polymers were assessed by using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometry, X-ray diffraction, and thermogravimetric analysis. The binding characteristics of magnetic molecularly imprinted polymers were researched through isothermal adsorption experiment, kinetics adsorption experiment, and the selectivity experiment. Coupled with ultra high performance liquid chromatography and tandem mass spectrometry, the extraction conditions of the magnetic molecularly imprinted polymers as adsorbents for avermectin were investigated in detail. The recovery of avermectin was 84.2-97.0%, and the limit of detection was 0.075 μg/kg. Relative standard deviations of intra- and inter-day precisions were in the range of 1.7-2.9% and 3.4-5.6%, respectively. The results demonstrated that the extraction method not only has high selectivity and accuracy, but also is convenient for the determination of avermectin in fish samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Contribution of Individual, Social and Work Characteristics to Employee Mental Health in a Coal Mining Industry Population.

PubMed

Considine, Robyn; Tynan, Ross; James, Carole; Wiggers, John; Lewin, Terry; Inder, Kerry; Perkins, David; Handley, Tonelle; Kelly, Brian

2017-01-01

Evidence regarding the extent of mental health problems and the associated characteristics within an employee population is necessary to inform appropriate and tailored workplace mental health programs. Mental health within male dominated industries (such as mining) has received recent public attention, chiefly through observations regarding suicide in such populations in Australia and internationally. Currently there is limited empirical evidence regarding the mental health needs in the mining industry as an exemplar of a male dominated workforce, and the relative contribution to such problems of individual, socio-economic and workplace factors. This study aimed to investigate the mental health and associated characteristics among employees in the Australian coal mining industry with a specific focus on identifying modifiable work characteristics. A cross-sectional study was conducted among employees (n = 1457) across eight coal mines stratified by key mine characteristics (state, mine type and employee commute arrangements). Participants completed measures of psychological distress (K10+) and key variables across four categories (socio-demographic characteristics, health history, current health behaviours, work attitudes and characteristics). Psychological distress levels within this sample were significantly higher in comparison with a community sample of employed Australians. The following factors contributed significantly to levels of psychological distress using hierarchical linear regression analysis: lower social networks; a past history of depression, anxiety or drug/alcohol problems; high recent alcohol use; work role (managers) and a set of work characteristics (level of satisfaction with work, financial factors and job insecurity; perception of lower workplace support for people with mental health problems. This is the first study to examine the characteristics associated with mental health problems in the Australian coal mining industry. The findings indicate the salience of mental health needs in this population, and the associated interplay of personal, social and work characteristics. The work characteristics associated with psychological distress are modifiable and can guide an industry response, as well as help inform the understanding of the role of workplace factors in mental health problems in a male dominated workforce more generally.

The Contribution of Individual, Social and Work Characteristics to Employee Mental Health in a Coal Mining Industry Population

PubMed Central

James, Carole; Wiggers, John; Lewin, Terry; Inder, Kerry; Perkins, David; Handley, Tonelle

2017-01-01

Background Evidence regarding the extent of mental health problems and the associated characteristics within an employee population is necessary to inform appropriate and tailored workplace mental health programs. Mental health within male dominated industries (such as mining) has received recent public attention, chiefly through observations regarding suicide in such populations in Australia and internationally. Currently there is limited empirical evidence regarding the mental health needs in the mining industry as an exemplar of a male dominated workforce, and the relative contribution to such problems of individual, socio-economic and workplace factors. This study aimed to investigate the mental health and associated characteristics among employees in the Australian coal mining industry with a specific focus on identifying modifiable work characteristics. Methods A cross-sectional study was conducted among employees (n = 1457) across eight coal mines stratified by key mine characteristics (state, mine type and employee commute arrangements). Participants completed measures of psychological distress (K10+) and key variables across four categories (socio-demographic characteristics, health history, current health behaviours, work attitudes and characteristics). Results Psychological distress levels within this sample were significantly higher in comparison with a community sample of employed Australians. The following factors contributed significantly to levels of psychological distress using hierarchical linear regression analysis: lower social networks; a past history of depression, anxiety or drug/alcohol problems; high recent alcohol use; work role (managers) and a set of work characteristics (level of satisfaction with work, financial factors and job insecurity; perception of lower workplace support for people with mental health problems. Conclusion This is the first study to examine the characteristics associated with mental health problems in the Australian coal mining industry. The findings indicate the salience of mental health needs in this population, and the associated interplay of personal, social and work characteristics. The work characteristics associated with psychological distress are modifiable and can guide an industry response, as well as help inform the understanding of the role of workplace factors in mental health problems in a male dominated workforce more generally. PMID:28045935

Riparian and Associated Habitat Characteristics Related to Nutrient Concentrations and Biological Responses of Small Streams in Selected Agricultural Areas, United States, 2003-04

USGS Publications Warehouse

Zelt, Ronald B.; Munn, Mark D.

2009-01-01

Physical factors, including both in-stream and riparian habitat characteristics that limit biomass or otherwise regulate aquatic biological condition, have been identified by previous studies. However, linking the ecological significance of nutrient enrichment to habitat or landscape factors that could allow for improved management of streams has proved to be a challenge in many regions, including agricultural landscapes, where many ecological stressors are strong and the variability among watersheds typically is large. Riparian and associated habitat characteristics were sampled once during 2003-04 for an intensive ecological and nutrients study of small perennial streams in five contrasting agricultural landscapes across the United States to determine how biological communities and ecosystem processes respond to varying levels of nutrient enrichment. Nutrient concentrations were determined in stream water at two different sampling times per site and biological samples were collected once per site near the time of habitat characterization. Data for 141 sampling sites were compiled, representing five study areas, located in parts of the Delmarva Peninsula (Delaware and Maryland), Georgia, Indiana, Ohio, Nebraska, and Washington. This report examines the available data for riparian and associated habitat characteristics to address questions related to study-unit contrasts, spatial scale-related differences, multivariate correlation structure, and bivariate relations between selected habitat characteristics and either stream nutrient conditions or biological responses. Riparian and associated habitat characteristics were summarized and categorized into 22 groups of habitat variables, with 11 groups representing land-use and land-cover characteristics and 11 groups representing other riparian or in-stream habitat characteristics. Principal components analysis was used to identify a reduced set of habitat variables that describe most of the variability among the sampled sites. The habitat characteristics sampled within the five study units were compared statistically. Bivariate correlations between riparian habitat variables and either nutrient-chemistry or biological-response variables were examined for all sites combined, and for sites within each study area. Nutrient concentrations were correlated with the extent of riparian cropland. For nitrogen species, these correlations were more frequently at the basin scale, whereas for phosphorus, they were about equally frequent at the segment and basin scales. Basin-level extents of riparian cropland and reach-level bank vegetative cover were correlated strongly with both total nitrogen and dissolved inorganic nitrogen (DIN) among multiple study areas, reflecting the importance of agricultural land-management and conservation practices for reducing nitrogen delivery from near-stream sources. When sites lacking segment-level wetlands were excluded, the negative correlation of riparian wetland extent with DIN among 49 sites was strong at the reach and segment levels. Riparian wetland vegetation thus may be removing dissolved nutrients from soil water and shallow groundwater passing through riparian zones. Other habitat variables that correlated strongly with nitrogen and phosphorus species included suspended sediment, light availability, and antecedent water temperature. Chlorophyll concentrations in seston were positively correlated with phosphorus concentrations for all sites combined. Benthic chlorophyll was correlated strongly with nutrient concentrations in only the Delmarva study area and only in fine-grained habitats. Current velocity or hydraulic scour could explain correlation patterns for benthic chlorophyll among Georgia sites, whereas chlorophyll in seston was correlated with antecedent water temperature among Washington and Delmarva sites. The lack of any consistent correlation pattern between habitat characteristics and organic material density (ash-free dry mass)

Mineralogical and chemical characteristics of some natural jarosites

USGS Publications Warehouse

Desborough, G.A.; Smith, K.S.; Lowers, H.A.; Swayze, G.A.; Hammarstrom, J.M.; Diehl, S.F.; Leinz, R.W.; Driscoll, R.L.

2010-01-01

This paper presents a detailed study of the mineralogical, microscopic, thermal, and spectral characteristics of jarosite and natrojarosite minerals. Systematic mineralogic and chemical examination of a suite of 32 natural stoichiometric jarosite and natrojarosite samples from diverse supergene and hydrothermal environments indicates that there is only limited solid solution between Na and K at low temperatures, which suggests the presence of a solvus in the jarosite-natrojarosite system at temperatures below about 140 ??C. The samples examined in this study consist of either end members or coexisting end-member pairs of jarosite and natrojarosite. Quantitative electron-probe microanalysis data for several natural hydrothermal samples show only end-member compositions for individual grains or zones, and no detectable alkali-site deficiencies, which indicates that there is no hydronium substitution within the analytical uncertainty of the method. In addition, there is no evidence of Fe deficiencies in the natural hydrothermal samples. Hydronium-bearing jarosite was detected in only one relatively young supergene sample suggesting that terrestrial hydronium-bearing jarosites generally are unstable over geologic timescales. Unit-cell parameters of the 20 natural stoichiometric jarosites and 12 natural stoichiometric natrojarosites examined in this study have distinct and narrow ranges in the a- and c-cell dimensions. There is no overlap of these parameters at the 1?? level for the two end-member compositions. Several hydrothermal samples consist of fine-scale (2-10 ??m) intimate intergrowths of jarosite and natrojarosite, which could have resulted from solid-state diffusion segregation or growth zoning due to variations in the Na/K activity ratio of hydrothermal solutions.

Self-regulated transport in photonic crystals with phase-changing defects

NASA Astrophysics Data System (ADS)

Thomas, Roney; Ellis, Fred M.; Vitebskiy, Ilya; Kottos, Tsampikos

2018-01-01

Phase-changing materials (PCMs) are widely used for optical data recording, sensing, all-optical switching, and optical limiting. Our focus here is on the case when the change in transmission characteristics of the optical material is caused by the input light itself. Specifically, the light-induced heating triggers the phase transition in the PCM. In this paper, using a numerical example, we demonstrate that the incorporation of the PCM in a photonic structure can lead to a dramatic modification of the effects of light-induced phase transition, as compared to a stand-alone sample of the same PCM. Our focus is on short pulses. We discuss some possible applications of such phase-changing photonic structures for optical sensing and limiting.

TRAN-STAT: statistics for environmental transuranic studies, July 1978, Number 5

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

Not Available

This issue is concerned with nonparametric procedures for (1) estimating the central tendency of a population, (2) describing data sets through estimating percentiles, (3) estimating confidence limits for the median and other percentiles, (4) estimating tolerance limits and associated numbers of samples, and (5) tests of significance and associated procedures for a variety of testing situations (counterparts to t-tests and analysis of variance). Some characteristics of several nonparametric tests are illustrated using the NAEG /sup 241/Am aliquot data presented and discussed in the April issue of TRAN-STAT. Some of the statistical terms used here are defined in a glossary. Themore » reference list also includes short descriptions of nonparametric books. 31 references, 3 figures, 1 table.« less

Returning migrant characteristics and labor market demand in Greece.

PubMed

Petras, E M; Kousis, M

1988-01-01

Immigrants who repatriate bring with them modern work skills which many observers in labor exporting regions describe as a great contribution to the mother country. Using data from 2 samples of Greek repatriates as well as projections of industrial labor force demands in Greece for the 1980s, this article challenges this concept. The authors find that the uneven regional development and stunted industrial growth which pushed these workers abroad are also responsible for the narrowly limited employment options which they face once they repatriate. For the urban repatriate, the market is limited to unemployment, the urban informal sector and scattered jobs, while for the rural repatriate, small-scale agriculture, multiple job holdings and unemployment are the only viable options.

Thermal diffusivity and adiabatic limit temperature characterization of consolidate granular expanded perlite using the flash method

NASA Astrophysics Data System (ADS)

Raefat, Saad; Garoum, Mohammed; Laaroussi, Najma; Thiam, Macodou; Amarray, Khaoula

2017-07-01

In this work experimental investigation of apparent thermal diffusivity and adiabatic limit temperature of expanded granular perlite mixes has been made using the flash technic. Perlite granulates were sieved to produce essentially three characteristic grain sizes. The consolidated samples were manufactured by mixing controlled proportions of the plaster and water. The effect of the particle size on the diffusivity was examined. The inverse estimation of the diffusivity and the adiabatic limit temperature at the rear face as well as the heat losses coefficients were performed using several numerical global minimization procedures. The function to be minimized is the quadratic distance between the experimental temperature rise at the rear face and the analytical model derived from the one dimension heat conduction. It is shown that, for all granulometry tested, the estimated parameters lead to a good agreement between the mathematical model and experimental data.

Sampling errors for a nadir viewing instrument on the International Space Station

NASA Astrophysics Data System (ADS)

Berger, H. I.; Pincus, R.; Evans, F.; Santek, D.; Ackerman, S.; Ackerman, S.

2001-12-01

In an effort to improve the observational charactarization of ice clouds in the earth's atmosphere, we are developing a sub-millimeter wavelength radiometer which we propose to fly on the International Space Station for two years. Our goal is to accurately measure the ice water path and mass-weighted particle size at the finest possible temporal and spatial resolution. The ISS orbit precesses, sampling through the dirunal cycle every 16 days, but technological constraints limit our instrument to a single pixel viewed near nadir. We discuss sampling errors associated with this instrument/platform configuration. We use as "truth" the ISCCP dataset of pixel-level cloud optical retrievals, which acts as a proxy for ice water path; this dataset is sampled according to the orbital characteristics of the space station, and the statistics computed from the sub-sampled population are compared with those from the full dataset. We explore the tradeoffs in average sampling error as a function of the averaging time and spatial scale, and explore the possibility of resolving the dirunal cycle.

Effect of Hurricane Hugo on molluscan skeletal distributions,Salt River Bay, St. Croix, U.S. Virgin Islands

NASA Astrophysics Data System (ADS)

Miller, Arnold I.; Llewellyn, Ghislaine; Parsons, Karla M.; Cummins, Hays; Boardman, Mark R.; Greenstein, Benjamin J.; Jacobs, David K.

1992-01-01

Just prior to the passage of Hurricane Hugo over St. Croix, U.S. Virgin Islands, 35 molluscan skeletal samples were collected at 30 m intervals along a sampling transect in Salt River Bay, on the north-central coast. Three months after the hurricane, the transect was resampled to permit direct assessment of storm effects on skeletal distributions. Results indicate that spatial zonation of molluscan accumulations, associated with environmental transitions along the transect, was maintained in the wake of the hurricane. However, limited transport was diagnosed by comparing the compositions of prestorm and poststorm samples from the deepest, mud-rich subenvironment on the transect. In aggregate, the species richness of samples from the southern half of this zone increased from 16 to 40, and the abundance of species that were not among the characteristic molluscs of this subenvironment increased from 11% to 26%. These storm effects could probably not have been recognized, and attributed directly to Hugo, had there been no prestorm samples with which to compare directly the poststorm samples.

Physical limitations in meal preparation and consumption are associated with lower musculoskeletal nutrient (calcium, vitamin D, magnesium, and phosphorus) intakes in homebound older adults.

PubMed

Sharkey, J; Johnson, C M; Dean, W R

2012-08-01

Although homebound older adults are at increased risk for poor nutritional health and adverse nutrition-related outcomes, little attention has focused on the tasks involved in meal preparation and consumption and the influence of those tasks on dietary intake. We examined the self-reported dietary intake from 3, 24-h dietary recalls and physical limitations in meal preparation and consumption (LMPC) activities from a randomly recruited sample of 345 homebound older men and women. Ordered logistic regression was used to examine the correlation of demographic characteristics and 6 activities with relative intakes of key musculoskeletal nutrients (calcium, vitamin D, magnesium, and phosphorus). At least 70% reported not meeting ⅔ recommended intakes for calcium and vitamin D; 12.5% failed to achieve ⅔ recommended intakes in at least three of the four nutrients. More than 12% of the sample reported it was very difficult or they were unable to perform at least 3 LMPC tasks. Regression results indicated that reporting the greatest LMPC increased the odds for lower intake of musculoskeletal nutrients. Independent of sociodemographic characteristics, self-reported difficulty in meal preparation and consumption was associated with lower dietary intakes of musculoskeletal nutrients. These results suggest the need to assess difficulty in meal preparation and consumption for the growing population of homebound older adults who participate in supplemental nutrition programs. This brief, 6-item measure may help identify older adults at risk of poor nutritional health and declining function.

Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Determination of Moderate-Use Pesticides and Selected Degradates in Water by C-18 Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry

USGS Publications Warehouse

Sandstrom, Mark W.; Stroppel, Max E.; Foreman, William T.; Schroeder, Michael P.

2001-01-01

A method for the isolation and analysis of 21 parent pesticides and 20 pesticide degradates in natural-water samples is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase-extraction columns that contain octadecyl-bonded porous silica to extract the analytes. The columns are dried by using nitrogen gas, and adsorbed analytes are eluted with ethyl acetate. Extracted analytes are determined by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 2 micrograms per liter (?g/L) for most analytes. Single-operator method detection limits in reagent-water samples range from 0.00 1 to 0.057 ?g/L. Validation data also are presented for 14 parent pesticides and 20 degradates that were determined to have greater bias or variability, or shorter holding times than the other compounds. The estimated maximum holding time for analytes in pesticide-grade water before extraction was 4 days. The estimated maximum holding time for analytes after extraction on the dry solid-phase-extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time. The method complements existing U.S. Geological Survey Method O-1126-95 (NWQL Schedules 2001 and 2010) by using identical sample preparation and comparable instrument analytical conditions so that sample extracts can be analyzed by either method to expand the range of analytes determined from one water sample.

Estimation of process capability indices from the results of limit gauge inspection of dimensional parameters in machining industry

NASA Astrophysics Data System (ADS)

Masterenko, Dmitry A.; Metel, Alexander S.

2018-03-01

The process capability indices Cp, Cpk are widely used in the modern quality management as statistical measures of the ability of a process to produce output X within specification limits. The customer's requirement to ensure Cp ≥ 1.33 is often applied in contracts. Capability indices estimates may be calculated with the estimates of the mean µ and the variability 6σ, and for it, the quality characteristic in a sample of pieces should be measured. It requires, in turn, using advanced measuring devices and well-qualified staff. From the other hand, quality inspection by attributes, fulfilled with limit gauges (go/no-go) is much simpler and has a higher performance, but it does not give the numerical values of the quality characteristic. The described method allows estimating the mean and the variability of the process on the basis of the results of limit gauge inspection with certain lower limit LCL and upper limit UCL, which separates the pieces into three groups: where X < LCL, number of pieces is n1, where LCL ≤ X < UCL, n2 pieces, and where X ≥ UCL, n3 pieces. So-called Pittman-type estimates, developed by the author, are functions of n1, n2, n3 and allow calculation of the estimated µ and σ. Thus, Cp and Cpk also may be estimated without precise measurements. The estimates can be used in quality inspection of lots of pieces as well as in monitoring and control of the manufacturing process. It is very important for improving quality of articles in machining industry through their tolerance.

The contribution of work and non-work factors to the onset of psychological distress: an eight-year prospective study of a representative sample of employees in Canada.

PubMed

Marchand, Alain; Blanc, Marie-Eve

2010-01-01

This study examined how occupation and work organization conditions contributed, over 8 yr, to the onset of psychological distress after adjusting for non-work and individual characteristics. The data came from the five cycles (Cycle 1=1994-1995, Cycle 5=2002-2003) of Statistics Canada's National Population Health Survey. A sample of 5,270 workers nested in 1,122 neighborhoods and aged 15 to 55 yr with no psychological distress at baseline was analyzed with discrete time survival multilevel regression models. The onset of psychological distress decreased over time. Occupation was not significant, whereas social support at work decreased the risk. Substantial effects for non-work and individual factors were found, including neighborhood, social support outside the workplace, demographics, physical health, personality traits, and life habits. This study found that work characteristics made a limited contribution to the onset of psychological distress, but social support in the workplace clearly proved to be an important protective factor. Enterprises must pay special attention to how colleagues and supervisors act to help workers complete tasks.

Influence of sintering temperature on the characteristics of shale brick containing oil well-derived drilling waste.

PubMed

Li, Xiang-Guo; Lv, Yang; Ma, Bao-Guo; Jian, Shou-Wei; Tan, Hong-Bo

2011-11-01

The influence of sintering temperature on the physico-mechanical characteristics (such as water absorption, apparent porosity, bulk density, weight loss on ignition, firing shrinkage, and compressive strength), leachability, and microstructure of shale brick containing oil well-derived drilling waste (DW) was investigated. The experiments were conducted at a temperature ranging from 950°C to 1,050°C with 30% DW addition. The results indicate that increasing the sintering temperature decreases the water absorption and apparent porosity and increases the shrinkage, density, and compressive strength of sintered specimens. Moreover, the physico-mechanical properties of samples sintered at 1,050°C meet the requirements of the MU20 according to GB/T 5101-2003 (in China). The heavy metal concentrations of the leachate are much lower than the current regulatory limits according to GB16889-2008. The results from XRD and SEM show that increasing sintering temperature results in an increase of the high temperature liquid phase, which may have a significant effect on the densification process of the samples.

Survey of physicochemical characteristics and microbial contamination in selected food locally vended in Morogoro Municipality, Tanzania.

PubMed

Nonga, Hezron Emmanuel; Ngowi, Helena Aminiel; Mdegela, Robinson Hammerthon; Mutakyawa, Eliud; Nyahinga, Gabriel Busungu; William, Robert; Mwadini, Mtumwa Mohd

2015-11-26

Raw milk, raw fruit juice and raw fish are enriched with essential nutrients for human diet but are prone to microbial contamination along the value chain. This cross sectional study was conducted to assess physicochemical characteristics and microbial quality of raw milk, fruit juice and fish from food vendors in Morogoro Municipality, Tanzania. The physicochemical assessment of food samples was done by smell, colour, presence of debris, turbidity, consistence, pH and clot on alcohol test. Hygiene of food containers, personnel and the vending environment was also assessed. Qualitative and quantitative microbial assessment of food was done using standard laboratory protocols as described by Tanzania Bureau of Standards and International Systems of Standards. Raw milk sold in Morogoro was of poor quality since was adulterated with water, contained sediments and clotted on alcohol test. Up to 63 % of the milk samples were contaminated with Escherichia coli and 60 % had higher total viable count (TVC) than the recommended values. Raw fruit juice was stored in dirty containers and sold under unhygienic environment. Seventy-three percent of juice samples had TVC beyond the recommendations while E. coli contamination rate was 63.3 %. The raw fish samples had started spoiling as depicted through sensory evaluation. E. coli contamination rate was 55 % and that of Campylobacter jejuni was 0.5 %. The mean TVC of raw fish was 8.1 (Log cfu/g) and 96.2 % of the fish samples had TVC beyond the recommended limits of 5.0 Log cfu/g. The physicochemical characteristics of food vended in Morogoro Municipality were of poor quality. The food had high bacterial contaminations. This situation poses health risks to the public and losses to food vendors due to spoilage. Stakeholders in food value chain should be educated on safe production and good hygienic practices. Routine quality and safety assessment of locally vended food, inspection of selling premises and regular health check-up of the personnel involved in food vending industry should be instituted.

Load-unloading response of intact and artificially degraded articular cartilage correlated with near infrared (NIR) absorption spectra.

PubMed

Afara, I O; Singh, S; Oloyede, A

2013-04-01

The conventional mechanical properties of articular cartilage, such as compressive stiffness, have been demonstrated to be limited in their capacity to distinguish intact (visually normal) from degraded cartilage samples. In this paper, we explore the correlation between a new mechanical parameter, namely the reswelling of articular cartilage following unloading from a given compressive load, and the near infrared (NIR) spectrum. The capacity to distinguish mechanically intact from proteoglycan-depleted tissue relative to the "reswelling" characteristic was first established, and the result was subsequently correlated with the NIR spectral data of the respective tissue samples. To achieve this, normal intact and enzymatically degraded samples were subjected to both NIR probing and mechanical compression based on a load-unload-reswelling protocol. The parameter δr, characteristic of the osmotic "reswelling" of the matrix after unloading to a constant small load in the order of the osmotic pressure of cartilage, was obtained for the different sample types. Multivariate statistics was employed to determine the degree of correlation between δr and the NIR absorption spectrum of relevant specimens using Partial Least Squared (PLS) regression. The results show a strong relationship (R(2)=95.89%, p<0.0001) between the spectral data and δr. This correlation of δr with NIR spectral data suggests the potential for determining the reswelling characteristics non-destructively. It was also observed that δr values bear a significant relationship with the cartilage matrix integrity, indicated by its proteoglycan content, and can therefore differentiate between normal and artificially degraded proteoglycan-depleted cartilage samples. It is therefore argued that the reswelling of cartilage, which is both biochemical (osmotic) and mechanical (hydrostatic pressure) in origin, could be a strong candidate for characterizing the tissue, especially in regions surrounding focal cartilage defects in joints. Copyright © 2012 Elsevier Ltd. All rights reserved.

An investigation of the psychological characteristics of stalkers: empathy, problem-solving, attachment and borderline personality features.

PubMed

Lewis, S F; Fremouw, W J; Del Ben, K; Farr, C

2001-01-01

This study examined the psychological characteristics of a sample of self-reported stalkers in comparison with a control group, on measures of empathy, problem-solving skills, attachment, and borderline personality features. Stalkers were identified by their endorsement of specific behavioral items, consistent with a widely adopted definition of stalking, denoting behaviors that: (a) are repeatedly directed toward an identified target; (b) are intrusive and unwanted; and (c) evoke fear in the victim. Stalkers scored significantly higher than controls on measures of insecure attachment and borderline personality features, suggesting that the stalking group demonstrates a general pattern of inadequate interpersonal attachment, has limited abilities to form and maintain appropriate relationships, is emotionally labile and unstable, and experiences ambivalence regarding their interpersonal relationships. Treatment implications are discussed herein.

Receiver operating characteristic (ROC) curves: review of methods with applications in diagnostic medicine

NASA Astrophysics Data System (ADS)

Obuchowski, Nancy A.; Bullen, Jennifer A.

2018-04-01

Receiver operating characteristic (ROC) analysis is a tool used to describe the discrimination accuracy of a diagnostic test or prediction model. While sensitivity and specificity are the basic metrics of accuracy, they have many limitations when characterizing test accuracy, particularly when comparing the accuracies of competing tests. In this article we review the basic study design features of ROC studies, illustrate sample size calculations, present statistical methods for measuring and comparing accuracy, and highlight commonly used ROC software. We include descriptions of multi-reader ROC study design and analysis, address frequently seen problems of verification and location bias, discuss clustered data, and provide strategies for testing endpoints in ROC studies. The methods are illustrated with a study of transmission ultrasound for diagnosing breast lesions.

[Mental health characteristics of men who abuse their intimate partners].

PubMed

Calvete, E

2008-10-01

The prevalence of psychopathological disorders amongst men who abuse their intimate partners has yet to be established. This article reviews studies carried out to ascertain the mental health characteristics of male domestic abusers. Most of these studies are based on samples of abusers under treatment or in prison. They generally assess the presence of psychopathological disorders through self-reports and diagnostic interviews are infrequently used. The results of this research show that domestic abusers tend to obtain high points for some types of personality disorders, especially narcissistic, antisocial and borderline disorders. They also present symptoms of depressive disorders and consumption of drugs and alcohol. Some studies also show that neurological problems are relatively frequent. Finally I discuss the limitations of current research and the implications for treatment of domestic abusers.

Sensitive detection of trimethylamine based on dopant-assisted positive photoionization ion mobility spectrometry.

PubMed

Cheng, Shasha; Li, Haitao; Jiang, Dandan; Chen, Chuang; Zhang, Tan; Li, Yong; Wang, Haitao; Zhou, Qinghua; Li, Haiyang; Tan, Mingqian

2017-01-01

Biogenic amines are degradation products generated through enzymatic and microbial processes during food spoilage, which may pose a health hazard to consumers at elevated levels. Trimethylamine (TMA) is a good target for the detection of biogenic amines due to its volatility and fishy odor. In this study, we developed a stand-alone dopant-assisted positive photoionization ion mobility spectrometry (DAPP-IMS) for rapid and sensitive detection of TMA. Response of TMA was enhanced by the addition of dopants and characteristic product ions with reduced mobility 2.26cm 2 V -1 s -1 were formed. 2-Butaone was chosen as the dopant for better separation between reagent ion peak and TMA product ion peak as well as higher sensitivity and the limit of detections (LODs) for TMA standard sample was 1ppb. The potential application of DAAP-IMS was evaluated by the detection of TMA generated by oyster and shrimp during 4°C storage. Analysis of two kinds of seafood showed the same characteristic peak to TMA standard sample, and the intensity of TMA increased over the storage time. The results of this study testify to the potential of DAPP-IMS for qualitative and quantitative determination of TMA in real food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Abundance and Distribution Characteristics of Microplastics in Surface Seawaters of the Incheon/Kyeonggi Coastal Region.

PubMed

Chae, Doo-Hyeon; Kim, In-Sung; Kim, Seung-Kyu; Song, Young Kyoung; Shim, Won Joon

2015-10-01

Microplastics in marine environments are of emerging concern due to their widespread distribution, their ingestion by various marine organisms, and their roles as a source and transfer vector of toxic chemicals. However, our understanding of their abundance and distribution characteristics in surface seawater (SSW) remains limited. We investigated microplastics in the surface microlayer (SML) and the SSW at 12 stations near-shore and offshore of the Korean west coast, Incheon/Kyeonggi region. Variation between stations, sampling media, and sampling methods were compared based on abundances, size distribution, and composition profiles of microsized synthetic polymer particles. The abundance of microplastics was greater in the SML (152,688 ± 92,384 particles/m(3)) than in SSW and showed a significant difference based on the sampling method for SSWs collected using a hand net (1602 ± 1274 particles/m(3)) and a zooplankton trawl net (0.19 ± 0.14 particles/m(3)). Ship paint particles (mostly alkyd resin polymer) accounted for the majority of microplastics detected in both SML and SSWs, and increased levels were observed around the voyage routes of large vessels. This indicates that polymers with marine-based origins become an important contributor to microplastics in coastal SSWs of this coastal region.

Patterns of technology use among older adults with and without disabilities.

PubMed

Gell, Nancy M; Rosenberg, Dori E; Demiris, George; LaCroix, Andrea Z; Patel, Kushang V

2015-06-01

The purpose of this study was to describe prevalence of technology use among adults ages 65 and older, particularly for those with disability and activity-limiting symptoms and impairments. Data from the 2011 National Health and Aging Trends Study, a nationally representative sample of community-dwelling Medicare beneficiaries (N = 7,609), were analyzed. Analysis consisted of technology use (use of e-mail/text messages and the internet) by sociodemographic and health characteristics and prevalence ratios for technology usage by disability status. Forty percent of older adults used e-mail or text messaging and 42.7% used the internet. Higher prevalence of technology use was associated with younger age, male sex, white race, higher education level, and being married (all p values <.001). After adjustment for sociodemographic and health characteristics, technology use decreased significantly with greater limitations in physical capacity and greater disability. Vision impairment and memory limitations were also associated with lower likelihood of technology use. Technology usage in U.S. older adults varied significantly by sociodemographic and health status. Prevalence of technology use differed by the type of disability and activity-limiting impairments. The internet, e-mail, and text messaging might be viable mediums for health promotion and communication, particularly for younger cohorts of older adults and those with certain types of impairment and less severe disability. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nevada National Security Site 2014 Data Report: Groundwater Monitoring Program Area 5 Radioactive Waste Management Site

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

Hudson, David

2015-02-01

This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site, Nye County, Nevada. Groundwater samples from the aquifer immediately below the Area 5 RWMS have been collected and analyzed and static water levels have been measured in this aquifer since 1993. This report updates these data to include the 2014 results. Analysis results for leachate contaminants collected from the mixed-waste cell at the Area 5 RWMS (Cell 18) are also included. During 2014, groundwater samples were collected and static water levels were measured at threemore » wells surrounding the Area 5 RWMS. Groundwater samples were collected at wells UE5PW-1, UE5PW-2, and UE5PW-3 on March 11 and August 12, 2014, and static water levels were measured at each of these wells on March 10, June 2, August 11, and October 14, 2014. Groundwater samples were analyzed for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. General water chemistry (cations and anions) was also measured. Results from samples collected in 2014 are within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. The data from the shallow aquifer indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS, and there were no significant changes in measured groundwater parameters compared to previous years. Leachate from above the primary liner of Cell 18 drains into a sump and is collected in a tank at the ground surface. Cell 18 began receiving waste in January 2011. Samples were collected from the tank when the leachate volume approached the 3,000-gallon tank capacity. Leachate samples have been collected 16 times since January 2011. During 2014, samples were collected on February 25, March 5, May 20, August 12, September 16, November 11, and December 16. Each leachate sample was analyzed for toxicity characteristic contaminants and polychlorinated biphenyls (PCB). Beginning with the sample from July 31, 2013, pH and specific conductance were also measured. Leachate analysis results show no evidence of contamination. Results for toxicity characteristic contaminants are all below regulatory levels and analysis quantification limits. No quantifiable PCB levels were detected in any sample. Results for pH and specific conductance are also within expected ranges. After analysis, leachate was pumped from the collection tank and used in Cell 18 for dust control. The report contains an updated cumulative chronology for the Area 5 RWMS Groundwater Monitoring Program and a brief description of the site hydrogeology.« less

Job characteristics and work safety climate among North Carolina farmworkers with H-2A visas.

PubMed

Arcury, Thomas A; Summers, Phillip; Talton, Jennifer W; Nguyen, Ha T; Chen, Haiying; Quandt, Sara A

2015-01-01

ABSTRACT Migrant farmworkers are a vulnerable population. Migrant farmworkers with H-2A visas are the only agricultural workers with temporary work permits. Little research has directly focused on the job characteristics and work safety of workers with H-2A visas. This analysis (1) describes their personal and job characteristics, job hazards, and stressors; (2) describes their perceived work safety climate; and (3) examines associations of perceived work safety climate with job characteristics, job hazards, and stressors. Data are from a cross-sectional component of a larger study of farmworker pesticide exposure; in 2012 interviews were conducted with 163 migrant farmworkers with H-2A visas in North Carolina. The sample was limited to men aged 30 to 70 years. Migrant farmworkers with H-2A visas experience the same hazards as do other farmworkers. Their mean score on the Perceived Work Safety Climate Scale 25.5 (SD = 3.7) is similar to that of other farmworkers and other immigrant workers. Perceived work safety climate is associated with hours worked per week (P = .02), precarious employment (P < .001), planting and cultivating (P = .002), topping tobacco (P = .0012), and stress (P = .02). Perceived work safety climate is particularly important for migrant farmworkers with H-2A visas because their labor contracts limit their options to change employers. Additional research on the status of work safety climate among agricultural workers is needed, as well as on the factors that affect work safety climate and on the safety characteristics that are affected by work safety climate. Policy changes that lead to improved work safety climate should be considered.

Job Characteristics and Work Safety Climate among North Carolina Farmworkers with H-2A Visas

PubMed Central

Arcury, Thomas A.; Summers, Phillip; Talton, Jennifer W.; Nguyen, Ha T.; Chen, Haiying; Quandt, Sara A.

2016-01-01

Migrant farmworkers are a vulnerable population. Migrant farmworkers with H-2A visas are the only agricultural workers with temporary work permits. Little research has directly focused on the job characteristics and work safety of workers with H-2A visas. This analysis (1) describes their personal and job characteristics, job hazards, and stressors; (2) describes their perceived work safety climate; and (3) examines associations of perceived work safety climate with job characteristics, job hazards, and stressors. Data are from a cross-sectional component of a larger study of farmworker pesticide exposure; in 2012 interviews were conducted with 163 migrant farmworkers with H-2A visas in North Carolina. The sample was limited to men aged 30 to 70 years. Migrant farmworkers with H-2A visas experience the same hazards as do other farmworkers. Their mean score on the perceived work safety climate scale 25.5 (SD=3.7) is similar to that of other farmworkers and other immigrant workers. Perceived work safety climate is associated with hours worked per week (p=0.02), precarious employment (p<0.001), planting and cultivating (p=0.002); topping tobacco (p=0.0012), and stress (p=0.02). Perceived work safety climate is particularly important for migrant farmworkers with H-2A visas because their labor contracts limit their options to change employers. Additional research on the status of work safety climate among agricultural workers is needed, as well as on the factors that affect work safety climate and on the safety characteristics that are affected by work safety climate. Policy changes that lead to improved work safety climate should be considered. PMID:25635744

Childhood-compared to adolescent-onset bipolar disorder has more statistically significant clinical correlates.

PubMed

Holtzman, Jessica N; Miller, Shefali; Hooshmand, Farnaz; Wang, Po W; Chang, Kiki D; Hill, Shelley J; Rasgon, Natalie L; Ketter, Terence A

2015-07-01

The strengths and limitations of considering childhood-and adolescent-onset bipolar disorder (BD) separately versus together remain to be established. We assessed this issue. BD patients referred to the Stanford Bipolar Disorder Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD Affective Disorders Evaluation. Patients with childhood- and adolescent-onset were compared to those with adult-onset for 7 unfavorable bipolar illness characteristics with replicated associations with early-onset patients. Among 502 BD outpatients, those with childhood- (<13 years, N=110) and adolescent- (13-18 years, N=218) onset had significantly higher rates for 4/7 unfavorable illness characteristics, including lifetime comorbid anxiety disorder, at least ten lifetime mood episodes, lifetime alcohol use disorder, and prior suicide attempt, than those with adult-onset (>18 years, N=174). Childhood- but not adolescent-onset BD patients also had significantly higher rates of first-degree relative with mood disorder, lifetime substance use disorder, and rapid cycling in the prior year. Patients with pooled childhood/adolescent - compared to adult-onset had significantly higher rates for 5/7 of these unfavorable illness characteristics, while patients with childhood- compared to adolescent-onset had significantly higher rates for 4/7 of these unfavorable illness characteristics. Caucasian, insured, suburban, low substance abuse, American specialty clinic-referred sample limits generalizability. Onset age is based on retrospective recall. Childhood- compared to adolescent-onset BD was more robustly related to unfavorable bipolar illness characteristics, so pooling these groups attenuated such relationships. Further study is warranted to determine the extent to which adolescent-onset BD represents an intermediate phenotype between childhood- and adult-onset BD. Copyright © 2015 Elsevier B.V. All rights reserved.

Radon Concentration And Dose Assessment In Well Water Samples From Karbala Governorate Of Iraq

NASA Astrophysics Data System (ADS)

Al-Alawy, I. T.; Hasan, A. A.

2018-05-01

There are numerous studies around the world about radon concentrations and their risks to the health of human beings. One of the most important social characteristics is the use of water wells for irrigation, which is a major source of water pollution with radon gas. In the present study, six well water samples have been collected from different locations in Karbala governorate to investigate radon concentration level using CR-39 technique. The maximum value 4.112±2.0Bq/L was in Al-Hurr (Al-Qarih Al-Easariah) region, and the lowest concentration of radon was in Hay Ramadan region which is 2.156±1.4Bq/L, with an average value 2.84±1.65Bq/L. The highest result of annual effective dose (AED) was in Al-Hurr (Al-Qarih Al-Easariah) region which is equal to 15.00±3.9μSv/y, while the minimum was recorded in Hay Ramadan 7.86±2.8μSv/y, with an average value 10.35±3.1μSv/y. The current results have shown that the radon concentrations in well water samples are lower than the recommended limit 11.1Bq/L and the annual effective dose in these samples are lower than the permissible international limit 1mSv/y.

Limitations in the use of commercial humic acids in water and soil research

USGS Publications Warehouse

Malcolm, R.L.; MacCarthy, P.

1986-01-01

Seven samples of commercial "humic acids", purchased from five different suppliers, were studied, and their characteristics were compared with humic and fulvic acids isolated from streams, soils, peat, leonardite, and a dopplerite sample. Cross-polarization and magic-angle spinning 13C NMR spectroscopy clearly shows pronounced differences between the commercial materials and all other samples. Elemental and infrared spectroscopic data do not show such clear-cut differences but can be used as supportive evidence, with the 13C NMR data, to substantiate the above distinctions. As a result of these differences and due to the general lack of information relating to the source, method of isolation, or other pretreatment of the commercial materials, these commercial products are not considered to be appropriate for use as analogues of true soil and water humic substances, in experiments designed to evaluate the nature and reactivity of humic substances in natural waters and soils.

Aflatoxin M1 in Tarhana chips.

PubMed

Özçam, Mustafa; Obuz, Ersel; Tosun, Halil

2014-01-01

Tarhana chips are a popular traditional fermented food consumed widely in the Kahramanmaraş region of Turkey. Tarhana chips are different from many other types of fermented food in that they are produced in the form of tortilla chips. Cereal and yoghurt are the main ingredients in Tarhana chips. Aflatoxin M1 (AFM1) levels in dairy and dairy-based products are of concern for human health. To investigate AFM1 contamination, a total of 40 samples were collected from Kahramanmaraş region and AFM1 levels were determined by competitive enzyme-linked immunosorbent assay (ELISA). Furthermore, physicochemical characteristics of Tarhana chips were investigated and compared with classic fried chips in terms of nutritional value. Based on data obtained from enzyme-linked immunosorbent assay, 21 (52.5%) out of 40 samples contained AFM1 in the range 0.5-36.6 ng/kg, so AFM1 levels of all samples were below the legal limit.

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.

A study of geriatric forensic evaluees: who are the violent elderly?

PubMed

Lewis, Catherine F; Fields, Cynthia; Rainey, Elizabeth

2006-01-01

The objective of this study was to examine a sample (n = 99) of elderly forensic evaluees to describe the psychiatric, medical, legal, and demographic characteristics of the sample and to examine which of these factors is associated with violent charges. Clinical data were gathered through retrospective chart review of patients aged 60 and over who were referred for criminal responsibility/competency-to-stand-trial evaluations from 1991 to 1998 at William S. Hall Psychiatric Institute in Columbia, South Carolina. Most (67.7%) of the sample was alcohol dependent, nearly one half (44.4%) had dementia, and close to one third (32.3%) had antisocial personality disorder. The majority of patients (60.6%) were facing violent charges and most (80.8%) were recidivists. In multivariate analysis, race, outpatient treatment status, crime location, and paranoia were all associated with violent charges. The implications and limitations of these data as applied to forensic treatment settings are discussed.

Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video

PubMed Central

Griffin, Ross A.; Robinson, Gary J.; West, Ashley; Gloyne-Phillips, Ian T.; Unsworth, Richard K. F.

2016-01-01

There remains limited knowledge of how offshore windfarm developments influence fish assemblages, particularly at a local scale around the turbine structures. Considering the existing levels of anthropogenic pressures on coastal fish populations it is becoming increasingly important for developers and environmental regulators to gain a more comprehensive understanding of the factors influencing fish assemblages. Improving our ability to assess such fish populations in close proximity to structures will assist in increasing this knowledge. In the present study we provide the first trial use of Baited Remote Underwater Stereo-Video systems (stereo BRUVs) for the quantification of motile fauna in close proximity to offshore wind turbines. The study was conducted in the Irish Sea and finds the technique to be a viable means of assessing the motile fauna of such environments. The present study found a mixture of species including bottom dwellers, motile crustaceans and large predatory fish. The majority of taxa observed were found to be immature individuals with few adult individuals recorded. The most abundant species were the angular crab (Goneplax rhomboides) and the small-spotted catshark (Scyliorhinus canicula). Of note in this study was the generally low abundance and diversity of taxa recorded across all samples, we hypothesise that this reflects the generally poor state of the local fauna of the Irish Sea. The faunal assemblages sampled in close proximity to turbines were observed to alter with increasing distance from the structure, species more characteristic of hard bottom environments were in abundance at the turbines (e.g. Homarus gammarus, Cancer pagarus, Scyliorhinus spp.) and those further away more characteristic of soft bottoms (e.g. Norwegian Lobster). This study highlights the need for the environmental impacts of offshore renewables on motile fauna to be assessed using targeted and appropriate tools. Stereo BRUVs provide one of those tools, but like the majority of methods for sampling marine biota, they have limitations. We conclude our paper by providing a discussion of the benefits and limitations of using this BRUV technique for assessing fauna within areas close to offshore windfarms. PMID:26934587

Nonmedical influences on medical decision making: an experimental technique using videotapes, factorial design, and survey sampling.

PubMed Central

Feldman, H A; McKinlay, J B; Potter, D A; Freund, K M; Burns, R B; Moskowitz, M A; Kasten, L E

1997-01-01

OBJECTIVE: To study nonmedical influences on the doctor-patient interaction. A technique using simulated patients and "real" doctors is described. DATA SOURCES: A random sample of physicians, stratified on such characteristics as demographics, specialty, or experience, and selected from commercial and professional listings. STUDY DESIGN: A medical appointment is depicted on videotape by professional actors. The patient's presenting complaint (e.g., chest pain) allows a range of valid interpretation. Several alternative versions are taped, featuring the same script with patient-actors of different age, sex, race, or other characteristics. Fractional factorial design is used to select a balanced subset of patient characteristics, reducing costs without biasing the outcome. DATA COLLECTION: Each physician is shown one version of the videotape appointment and is asked to describe how he or she would diagnose or treat such a patient. PRINCIPAL FINDINGS: Two studies using this technique have been completed to date, one involving chest pain and dyspnea and the other involving breast cancer. The factorial design provided sufficient power, despite limited sample size, to demonstrate with statistical significance various influences of the experimental and stratification variables, including the patient's gender and age and the physician's experience. Persistent recruitment produced a high response rate, minimizing selection bias and enhancing validity. CONCLUSION: These techniques permit us to determine, with a degree of control unattainable in observational studies, whether medical decisions as described by actual physicians and drawn from a demographic or professional group of interest, are influenced by a prescribed set of nonmedical factors. PMID:9240285

Price promotions for food and beverage products in a nationwide sample of food stores.

PubMed

Powell, Lisa M; Kumanyika, Shiriki K; Isgor, Zeynep; Rimkus, Leah; Zenk, Shannon N; Chaloupka, Frank J

2016-05-01

Food and beverage price promotions may be potential targets for public health initiatives but have not been well documented. We assessed prevalence and patterns of price promotions for food and beverage products in a nationwide sample of food stores by store type, product package size, and product healthfulness. We also assessed associations of price promotions with community characteristics and product prices. In-store data collected in 2010-2012 from 8959 food stores in 468 communities spanning 46 U.S. states were used. Differences in the prevalence of price promotions were tested across stores types, product varieties, and product package sizes. Multivariable regression analyses examined associations of presence of price promotions with community racial/ethnic and socioeconomic characteristics and with product prices. The prevalence of price promotions across all 44 products sampled was, on average, 13.4% in supermarkets (ranging from 9.1% for fresh fruits and vegetables to 18.2% for sugar-sweetened beverages), 4.5% in grocery stores (ranging from 2.5% for milk to 6.6% for breads and cereals), and 2.6% in limited service stores (ranging from 1.2% for fresh fruits and vegetables to 4.1% for breads and cereals). No differences were observed by community characteristics. Less-healthy versus more-healthy product varieties and larger versus smaller product package sizes generally had a higher prevalence of price promotion, particularly in supermarkets. On average, in supermarkets, price promotions were associated with 15.2% lower prices. The observed patterns of price promotions warrant more attention in public health food environment research and intervention. Copyright © 2016 Elsevier Inc. All rights reserved.

Flow and transport in digitized images of Berea sandstone: ergodicity, stationarity and upscaling

NASA Astrophysics Data System (ADS)

Puyguiraud, A.; Dentz, M.; Gouze, P.

2017-12-01

We perform Stokes flow simulations on digitized images of a Berea sandstone sample obtained through micro-tomography imaging and segmentation processes. We obtain accurate information on the transport using a streamline reconstruction algorithm which uses the velocity field obtained from the flow simulation as input data. This technique is based on the method proposed by Pollock (Groundwater, 1988) but employs a quadratic interpolation near the rock mesh cells of the domain similarly to Mostaghimi et al. (SPE, 2012). This allows an accurate resolution of the velocity field near the solid interface which plays an important role on the transport characteristics, such as the probability density of first arrival times and the growth of the mean squared displacement, among others, which exhibit non-Fickian behavior. We analyze Lagrangian and Eulerian velocity statistics and their relation, and then focus on the ergodicity and the stationarity properties of the transport.We analyze the temporal evolution of Lagrangian velocity statistics for different injection conditions, and findd quick convergence to a limiting velocity distribution, indicating the transport to be near-stationary. The equivalence between velocity samplings within and across streamlines, as well as the independency of the statistics on the number of sampled streamlines, lead as to conclude that the transport may be modeled as ergodic.These characteristics then allow us to upscale the 3-dimensional simulations using a 1-dimensional Continuous Time Random Walk model. This model, parametrized by the velocity results and the characteristic correlation length obtained from the above mentioned simulations, is able to efficiently reproduce the results and to predict larger scale behaviors.

Fast quantitative detection of cocaine in beverages using nanoextractive electrospray ionization tandem mass spectrometry.

PubMed

Hu, Bin; Peng, Xuejiao; Yang, Shuiping; Gu, Haiwei; Chen, Huanwen; Huan, Yanfu; Zhang, Tingting; Qiao, Xiaolin

2010-02-01

Without any sample pretreatment, effervescent beverage fluids were manually sprayed into the primary ion plume created by using a nanoelectrospray ionization source for direct ionization, and the analyte ions of interest were guided into an ion trap mass spectrometer for tandem mass analysis. Functional ingredients (e.g., vitamins, taurine, and caffeine, etc.) and spiked impurity (e.g., cocaine) in various beverages, such as Red Bull energy drink, Coco-cola, and Pepsi samples were rapidly identified within 1.5 s. The limit of detection was found to be 7-15 fg (S/N = 3) for cocaine in different samples using the characteristic fragment (m/z 150) observed in the MS(3) experiments. Typical relative standard deviation and recovery of this method were 6.9%-8.6% and 104%-108% for direct analysis of three actual samples, showing that nanoextractive electrospray ionization tandem mass spectrometry is a useful technique for fast screening cocaine presence in beverages. 2010. Published by Elsevier Inc.

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

PubMed Central

2017-01-01

Due to their electrochemical and economical characteristics, pencil graphite electrodes (PGEs) gained in recent years a large applicability to the analysis of various types of inorganic and organic compounds from very different matrices. The electrode material of this type of working electrodes is constituted by the well-known and easy commercially available graphite pencil leads. Thus, PGEs are cheap and user-friendly and can be employed as disposable electrodes avoiding the time-consuming step of solid electrodes surface cleaning between measurements. When compared to other working electrodes PGEs present lower background currents, higher sensitivity, good reproducibility, and an adjustable electroactive surface area, permitting the analysis of low concentrations and small sample volumes without any deposition/preconcentration step. Therefore, this paper presents a detailed overview of the PGEs characteristics, designs and applications of bare, and electrochemically pretreated and chemically modified PGEs along with the corresponding performance characteristics like linear range and detection limit. Techniques used for bare or modified PGEs surface characterization are also reviewed. PMID:28255500

Malaysian and Singaporean students' affective characteristics and mathematics performance: evidence from PISA 2012.

PubMed

Thien, Lei Mee; Ong, Mei Yean

2015-01-01

This paper attempts to identify the extent to which the affective characteristics of Malaysian and Singaporean students' attainment compared to the OECD average in Programme for International Student Assessment (PISA) 2012, and examine the influence of students' affective characteristics, gender, and their socioeconomic status on mathematics performance at both student and school levels. Sample consisted of 5197 and 5546 15-year-old Malaysian and Singaporean students. Data were analysed using hierarchical linear modelling approach with HLM 7.0 software. Results showed that the Index of economic, social, and cultural status (ESCS), mathematics self-efficacy, and mathematics anxiety have significant effects on mathematics performance in Malaysia and Singapore at the student level. Proportion of boys at the school level has no significant effects on mathematics performance for both Malaysian and Singaporean students. ESCS mean at the school level has positive and significant effects on mathematics performance in Malaysia, but not in Singapore. Limitations, implications, and future studies were discussed.

Spectral characterization as a tool for parchment analysis

NASA Astrophysics Data System (ADS)

Radis, Michela; Iacomussi, Paola; Rossi, Giuseppe

2015-06-01

The paper presents an investigation on the correlation between spectral characteristics and conservation conditions of parchment to define a NON invasive methodology able to detect and monitor deterioration process in historical parchment without the need of taking small samples. To verify the feasibility and define the most appropriate measurement method, several samples of contemporary parchments, produced following ancient recipes and coming from different animal species, with different degrees of artificially induced damage, were analyzed. The SRF and STF of each sample were measured in the same point, before and after each step of the artificial ageing treatment. Having at disposal a parchment coming from a whole lamb leather, allowed also the study of the correlations between the variations of SRF - STF and the intrinsic factors of a parchment like the variability of animal skin anatomy and of manufacturing. Analyzing different samples allowed also the definition of the measuring method sensitivity and of reference spectrum for the different animal species parchments with accuracy limits. The definition of a reference spectrum of not damaged parchment with acceptability limits is a necessary step for understanding, through SRF - STF measurements, historical parchments conservation conditions: indeed it is necessary to know if deviations from the reference spectrum are ascribable to damage or only to parchment anatomic/production variability. As a case study, the method has been applied to two historical parchment scrolls stored at the Archivio di Stato di Torino (Italy). The SRF - STF of both scrolls was acquired in several points of the scroll, the average spectrum of each scroll was compared with the reference spectra with the relative tolerance limits, recognizing the animal species and damage alterations and demonstrating the feasibility of the method.

Occurrence of veterinary pharmaceuticals in the aquatic environment in Flanders

NASA Astrophysics Data System (ADS)

Servaes, K.; Vanermen, G.; Seuntjens, P.

2009-04-01

There is a growing interest in the occurrence of pharmaceuticals in the aquatic environment. Pharmaceuticals are classified as so-called ‘emerging pollutants'. ‘Emerging pollutants' are not necessarily new chemical compounds. Often these compounds are already present in the environment for a long time. But, their occurrence and especially their impact on the environment has only recently become clear. Consequently, data on their occurrence are rather scarce. In this study, we focus on the occurrence of veterinary pharmaceuticals in surface water in Flanders. We have only considered active substances administered to cattle, pigs and poultry. Based on the literature and information concerning the use in Belgium, a selection of 25 veterinary pharmaceuticals has been made. This selection consists of the most important antibiotics and antiparasitic substances applied in veterinary medicine in Belgium. We develop an analytical methodology based on UPLC-MS/MS for the detection of these veterinary pharmaceuticals in surface water. Therefore, the mass characteristics as well as the optimum LC conditions will be determined. To obtain limits of detection as low as possible, the samples are concentrated prior to analysis using solid phase extraction (SPE). Different SPE cartridges will be tested during the method development. At first, this SPE sample pre-treatment is performed off-line. In a next step, online SPE is optimized for this purpose. The analytical procedure will be subject to an in-house validation study, thereby determining recovery, repeatability (% RSD), limits of detection and limits of quantification. Finally, the developed methodology will be applied for monitoring the occurrence of veterinary pharmaceuticals in surface water and groundwater in Flanders. These water samples will be taken in areas characterized by intensive cattle breeding. Moreover, the samples will be collected during springtime. In this season, farmers apply manure, stored during winter, onto the fields.

Characterization of the MVST waste tanks located at ORNL

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

Keller, J.M.; Giaquinto, J.M.; Meeks, A.M.

During the fall of 1996 there was a major effort to sample and analyze the Active Liquid Low-Level Waste (LLLW) tanks at ORNL which include the Melton Valley Storage Tanks (MVST) and the Bethel Valley Evaporator Service Tanks (BVEST). The characterization data summarized in this report was needed to address waste processing options, address concerns of the performance assessment (PA) data for the Waste Isolation Pilot Plant (WIPP), evaluate the characteristics with respect to the waste acceptance criteria (WAC) for WIPP and Nevada Test Site (NTS), address criticality concerns, and meet DOT requirements for transporting the waste. This report onlymore » discusses the analytical characterization data for the MVST waste tanks. The isotopic data presented in this report support the position that fissile isotopes of uranium and plutonium were ``denatured`` as required by administrative controls. In general, MVST sludge was found to be both hazardous by RCRA characteristics and the transuranic alpha activity was well about the limit for TRU waste. The characteristics of the MVST sludge relative to the WIPP WAC limits for fissile gram equivalent, plutonium equivalent activity, and thermal power from decay heat, were estimated from the data in this report and found to be far below the upper boundary for any of the remote-handled transuranic waste requirements for disposal of the waste in WIPP.« less

Hydrogeologic and chemical data for the O-Field area, Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Nemoff, P.R.; Vroblesky, D.A.

1989-01-01

O-Field, located at the Edgewood area of Aberdeen Proving Ground , Maryland, was periodically used for disposal of munitions, waste chemicals, and chemical-warfare agents from World War II through the 1950' s. This report includes various physical, geologic, chemical, and hydrologic data obtained from well-core, groundwater, surface water, and bottom-sediment sampling sites at and near the O-Field disposal area. The data are presented in tables and hydrographs. Three site-location maps are also included. Well-core data include lithologic logs for 11 well- cluster sites, grain-size distributions, various chemical characteristics, and confining unit characteristics. Groundwater data include groundwater chemistry, method blanks for volatile organic carbon, available data on volatile and base/neutral organics, and compilation of corresponding method blanks, chemical-warfare agents, explosive-related products, radionuclides, herbicides, and groundwater levels. Surface-water data include field-measured characteristics; concentrations of various inorganic constituents including arsenic; selected organic constituents with method blanks; detection limits of organics; and a compilation of information on corresponding acids, volatiles, and semivolatiles. Bottom- sediment data include inorganic properties and constituents; organic chemistry; detection limits for organic chemicals; a compilation of information on acids, volatiles, and semivolatiles; and method blanks corresponding to acids, volatiles, and semivolatiles. A set of 15 water- level hydrographs for the period March 1986 through September 1987 also is included in the report. (USGS)

Generation of sub-femtoliter droplet by T-junction splitting on microfluidic chips

NASA Astrophysics Data System (ADS)

Yang, Yu-Jun; Feng, Xuan; Xu, Na; Pang, Dai-Wen; Zhang, Zhi-Ling

2013-03-01

In the paper, sub-femtoliter droplets were easily produced by droplet splitting at a simple T-junction with orifice, which did not need expensive equipments, complex photolithography skill, or high energy input. The volume of the daughter droplet was not limited by channel size but controlled by channel geometry and fluidic characteristic. Moreover, single bead sampling and bead quantification in different orders of magnitude of droplet volumes were investigated. The droplets split at our T-junction chip had small volume and monodispersed size and could be produced efficiently, orderly, and controllably.

Career success implications of political skill.

PubMed

Todd, Samuel Y; Harris, Kenneth J; Harris, Ranida B; Wheeler, Anthony R

2009-06-01

The authors investigated the individual characteristic of political skill and its relation to 5 different career-related outcomes (total compensation, promotions, career satisfaction, life satisfaction, and perceived external job mobility). They examined data obtained from a sample of 191 employees working a wide range of occupations. The results reveal that political skill is associated with 4 of the 5 outcomes. In addition, they examined the 4 dimensions of political skill and found that the networking ability dimension dominates the relations with the examined outcomes. The authors discuss practical implications, limitations, and directions for future research.

Wiggles and knots in radio jets

NASA Astrophysics Data System (ADS)

Trussoni, E.; Ferrari, A.; Zaninetti, L.

Dynamical effects in binary nuclei inside parent galactic cores, gravitational interactions with companion galaxies, and Kelvin-Helmholtz instabilities in the flow propagation have been proposed as mechanism responsible for the formation of the low amplitude morphologies, wiggles and knots, observed in radio jets. Here the basic characteristics and implications of these models are discussed with reference to the limited sample of existing data. In conclusion it will be shown that present observations cannot discriminate definitely these theories; conversely, different mechanisms may be at work together in any jet at the same time.

Quasi-Uniform High Speed Foam Crush Testing Using a Guided Drop Mass Impact

NASA Technical Reports Server (NTRS)

Jones, Lisa E. (Technical Monitor); Kellas, Sotiris

2004-01-01

A relatively simple method for measuring the dynamic crush response of foam materials at various loading rates is described. The method utilizes a drop mass impact configuration with mass and impact velocity selected such that the crush speed remains approximately uniform during the entire sample crushing event. Instrumentation, data acquisition, and data processing techniques are presented, and limitations of the test method are discussed. The objective of the test method is to produce input data for dynamic finite element modeling involving crash and energy absorption characteristics of foam materials.

Optimized probability sampling of study sites to improve generalizability in a multisite intervention trial.

PubMed

Kraschnewski, Jennifer L; Keyserling, Thomas C; Bangdiwala, Shrikant I; Gizlice, Ziya; Garcia, Beverly A; Johnston, Larry F; Gustafson, Alison; Petrovic, Lindsay; Glasgow, Russell E; Samuel-Hodge, Carmen D

2010-01-01

Studies of type 2 translation, the adaption of evidence-based interventions to real-world settings, should include representative study sites and staff to improve external validity. Sites for such studies are, however, often selected by convenience sampling, which limits generalizability. We used an optimized probability sampling protocol to select an unbiased, representative sample of study sites to prepare for a randomized trial of a weight loss intervention. We invited North Carolina health departments within 200 miles of the research center to participate (N = 81). Of the 43 health departments that were eligible, 30 were interested in participating. To select a representative and feasible sample of 6 health departments that met inclusion criteria, we generated all combinations of 6 from the 30 health departments that were eligible and interested. From the subset of combinations that met inclusion criteria, we selected 1 at random. Of 593,775 possible combinations of 6 counties, 15,177 (3%) met inclusion criteria. Sites in the selected subset were similar to all eligible sites in terms of health department characteristics and county demographics. Optimized probability sampling improved generalizability by ensuring an unbiased and representative sample of study sites.

Statistical and sampling issues when using multiple particle tracking

NASA Astrophysics Data System (ADS)

Savin, Thierry; Doyle, Patrick S.

2007-08-01

Video microscopy can be used to simultaneously track several microparticles embedded in a complex material. The trajectories are used to extract a sample of displacements at random locations in the material. From this sample, averaged quantities characterizing the dynamics of the probes are calculated to evaluate structural and/or mechanical properties of the assessed material. However, the sampling of measured displacements in heterogeneous systems is singular because the volume of observation with video microscopy is finite. By carefully characterizing the sampling design in the experimental output of the multiple particle tracking technique, we derive estimators for the mean and variance of the probes’ dynamics that are independent of the peculiar statistical characteristics. We expose stringent tests of these estimators using simulated and experimental complex systems with a known heterogeneous structure. Up to a certain fundamental limitation, which we characterize through a material degree of sampling by the embedded probe tracking, these estimators can be applied to quantify the heterogeneity of a material, providing an original and intelligible kind of information on complex fluid properties. More generally, we show that the precise assessment of the statistics in the multiple particle tracking output sample of observations is essential in order to provide accurate unbiased measurements.

Transition from Forward Smoldering to Flaming in Small Polyurethane Foam Samples

NASA Technical Reports Server (NTRS)

Bar-Ilan, A.; Putzeys, O.; Rein, G.; Fernandez-Pello, A. C.

2004-01-01

Experimental observations are presented of the effect of the flow velocity and oxygen concentration, and of a thermal radiant flux, on the transition from smoldering to flaming in forward smoldering of small samples of polyurethane foam with a gas/solid interface. The experiments are part of a project studying the transition from smolder to flaming under conditions encountered in spacecraft facilities, i.e., microgravity, low velocity variable oxygen concentration flows. Because the microgravity experiments are planned for the International Space Station, the foam samples had to be limited in size for safety and launch mass reasons. The feasible sample size is too small for smolder to self propagate because of heat losses to the surrounding environment. Thus, the smolder propagation and the transition to flaming had to be assisted by reducing the heat losses to the surroundings and increasing the oxygen concentration. The experiments are conducted with small parallelepiped samples vertically placed in a wind tunnel. Three of the sample lateral-sides are maintained at elevated temperature and the fourth side is exposed to an upward flow and to a radiant flux. It is found that decreasing the flow velocity and increasing its oxygen concentration, and/or increasing the radiant flux enhances the transition to flaming, and reduces the delay time to transition. Limiting external ambient conditions for the transition to flaming are reported for the present experimental set-up. The results show that smolder propagation and the transition to flaming can occur in relatively small fuel samples if the external conditions are appropriate. The results also indicate that transition to flaming occurs in the char left behind by the smolder reaction, and it has the characteristics of a gas-phase ignition induced by the smolder reaction, which acts as the source of both gaseous fuel and heat.

Screening efficiency of the self-report version of the Multidimensional Anxiety Scale for Children in a highly comorbid inpatient sample.

PubMed

Skarphedinsson, Gudmundur; Villabø, Marianne A; Lauth, Bertrand

2015-01-01

The Multidimensional Anxiety Scale for Children (MASC) is a widely used self-report questionnaire for the assessment of anxiety symptoms in children and adolescents with well documented predictive validity of the total score and subscales in internalizing and mixed clinical samples. However, no data exist on the screening efficiency in an inpatient sample of adolescents. To examine the psychometric properties and screening efficiency of the MASC in a high comorbid inpatient sample. The current study used receiver operating characteristic (ROC) analyses to investigate the predictive value of the MASC total and subscale scores for the Schedule for Affective Disorders and Schizophrenia for School-age children-Present and Lifetime version (K-SADS-PL), DSM-IV diagnoses of generalized anxiety disorder (GAD), separation anxiety disorder (SAD) and social phobia (SoP) in a highly comorbid inpatient sample of adolescents (11-18 years). The MASC total score predicted any anxiety disorder (AD) and GAD moderately well. Physical symptoms predicted GAD moderately well. Social anxiety and separation anxiety/panic did not predict SoP or SAD, respectively. Physical symptoms and harm avoidance also predicted the presence of major depressive disorder. The findings support the utility of the MASC total score to predict the presence of any AD and GAD. However, the utility of the social anxiety and separation anxiety/panic subscales showed limited utility to predict the presence of SAD and SoP, respectively. The MASC has probably a more limited function in screening for AD among a highly comorbid inpatient sample of severely affected adolescents. Our results should be interpreted in the light of a small, mixed sample of inpatient adolescents.

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.

Investigation of niobium surface structure and composition for improvement of superconducting radio-frequency cavities

NASA Astrophysics Data System (ADS)

Trenikhina, Yulia

Nano-scale investigation of intrinsic properties of niobium near-surface is a key to control performance of niobium superconducting radio-frequency cavities. Mechanisms responsible for the performance limitations and their empirical remedies needs to be justified in order to reproducibly control fabrication of SRF cavities with desired characteristics. The high field Q-slope and mechanism behind its cure (120°C mild bake) were investigated by comparison of the samples cut out of the cavities with high and low dissipation regions. Material evolution during mild field Q-slope nitrogen treatment was characterized using the coupon samples as well as samples cut out of nitrogen treated cavity. Evaluation of niobium near-surface state after some typical and novel cavity treatments was accomplished. Various TEM techniques, SEM, XPS, AES, XRD were used for the structural and chemical characterization of niobium near-surface. Combination of thermometry and structural temperature-dependent comparison of the cavity cutouts with different dissipation characteristics revealed precipitation of niobium hydrides to be the reason for medium and high field Q-slopes. Step-by-step effect of the nitrogen treatment processing on niobium surface was studied by analytical and structural characterization of the cavity cutout and niobium samples, which were subject to the treatment. Low concentration nitrogen doping is proposed to explain the benefit of nitrogen treatment. Chemical characterization of niobium samples before and after various surface processing (Electropolishing (EP), 800°C bake, hydrofluoric acid (HF) rinsing) showed the differences that can help to reveal the microscopic effects behind these treatments as well as possible sources of surface contamination.

The Use and Abuse of Limits of Detection in Environmental Analytical Chemistry

PubMed Central

Brown, Richard J. C.

2008-01-01

The limit of detection (LoD) serves as an important method performance measure that is useful for the comparison of measurement techniques and the assessment of likely signal to noise performance, especially in environmental analytical chemistry. However, the LoD is only truly related to the precision characteristics of the analytical instrument employed for the analysis and the content of analyte in the blank sample. This article discusses how other criteria, such as sampling volume, can serve to distort the quoted LoD artificially and make comparison between various analytical methods inequitable. In order to compare LoDs between methods properly, it is necessary to state clearly all of the input parameters relating to the measurements that have been used in the calculation of the LoD. Additionally, the article discusses that the use of LoDs in contexts other than the comparison of the attributes of analytical methods, in particular when reporting analytical results, may be confusing, less informative than quoting the actual result with an accompanying statement of uncertainty, and may act to bias descriptive statistics. PMID:18690384

Two-dimensional sparse wavenumber recovery for guided wavefields

NASA Astrophysics Data System (ADS)

Sabeti, Soroosh; Harley, Joel B.

2018-04-01

The multi-modal and dispersive behavior of guided waves is often characterized by their dispersion curves, which describe their frequency-wavenumber behavior. In prior work, compressive sensing based techniques, such as sparse wavenumber analysis (SWA), have been capable of recovering dispersion curves from limited data samples. A major limitation of SWA, however, is the assumption that the structure is isotropic. As a result, SWA fails when applied to composites and other anisotropic structures. There have been efforts to address this issue in the literature, but they either are not easily generalizable or do not sufficiently express the data. In this paper, we enhance the existing approaches by employing a two-dimensional wavenumber model to account for direction-dependent velocities in anisotropic media. We integrate this model with tools from compressive sensing to reconstruct a wavefield from incomplete data. Specifically, we create a modified two-dimensional orthogonal matching pursuit algorithm that takes an undersampled wavefield image, with specified unknown elements, and determines its sparse wavenumber characteristics. We then recover the entire wavefield from the sparse representations obtained with our small number of data samples.

A look at motion in the frequency domain

NASA Technical Reports Server (NTRS)

Watson, A. B.; Ahumada, A. J., Jr.

1983-01-01

A moving image can be specified by a contrast distribution, c(x,y,t), over the dimensions of space x,y, and time t. Alternatively, it can be specified by the distribution C(u,v,w) over spatial frequency u,v and temporal frequency w. The frequency representation of a moving image is shown to have a characteristic form. This permits two useful observations. The first is that the apparent smoothness of time-sampled moving images (apparent motion) can be explained by the filtering action of the human visual system. This leads to the following formula for the required update rate for time-sampled displays. W(c)=W(l)+ru(l) where w(c) is the required update rate in Hz, W(l) is the limit of human temporal resolution in Hz, r is the velocity of the moving image in degrees/sec, and u(l) is the limit of human spatial resolution in cycles/deg. The second observation is that it is possible to construct a linear sensor that responds to images moving in a particular direction. The sensor is derived and its properties are discussed.

Separation and quantification of monoclonal-antibody aggregates by hollow-fiber-flow field-flow fractionation.

PubMed

Fukuda, Jun; Iwura, Takafumi; Yanagihara, Shigehiro; Kano, Kenji

2014-10-01

Hollow-fiber-flow field-flow fractionation (HF5) separates protein molecules on the basis of the difference in the diffusion coefficient, and can evaluate the aggregation ratio of proteins. However, HF5 is still a minor technique because information on the separation conditions is limited. We examined in detail the effect of different settings, including the main-flow rate, the cross-flow rate, the focus point, the injection amount, and the ionic strength of the mobile phase, on fractographic characteristics. On the basis of the results, we proposed optimized conditions of the HF5 method for quantification of monoclonal antibody in sample solutions. The HF5 method was qualified regarding the precision, accuracy, linearity of the main peak, and quantitation limit. In addition, the HF5 method was applied to non-heated Mab A and heat-induced-antibody-aggregate-containing samples to evaluate the aggregation ratio and the distribution extent. The separation performance was comparable with or better than that of conventional methods including analytical ultracentrifugation-sedimentation velocity and asymmetric-flow field-flow fractionation.

Analytical methods for multiresidue determination of sulfonamides and trimethoprim in meat and ground water samples by CE-MS and CE-MS/MS.

PubMed

Soto-Chinchilla, Jorge J; García-Campaña, Ana M; Gámiz-Gracia, Laura

2007-11-01

This paper presents two methods based on CZE-MS detection and CZE-MS/MS detection developed for the multiresidue determination of ten sulfonamides (sulfapyridine, sulfadoxin, sulfamethazine, sulfadimethoxine, sulfameter, sulfamerazine, sulfachlorpyridazine, sulfadiazine, sulfamethoxazole, and sulfamethizole) and a potentiator, trimethoprim (TMP), whose contents are regulated by the EU Council Regulation no. 2377/90 in animal edible tissues. Experimental designs were employed to optimize the electrospray conditions. MS/MS experiments using an IT as analyzer operating in multiple reaction monitoring (MRM) mode were carried out to achieve the minimum number of points according to the 2002/657/EC European Decision for unambiguous identification. The proposed procedures have been compared in terms of the performance characteristics and trueness. The limits of detection and quantification were in all cases lower than the maximum residue limits legislated for these compounds and the recoveries were satisfactory, being possible the application for their monitoring in foodstuff of animal origin and in environmental samples, allowing the determination of sulfonamides and TMP residues in meat and in superficial water in the low microg/L range.

Lactic acid concentrations that reduce microbial load yet minimally impact colour and sensory characteristics of beef.

PubMed

Rodríguez-Melcón, Cristina; Alonso-Calleja, Carlos; Capita, Rosa

2017-07-01

Lactic acid (LA) has recently been approved in the EU as beef decontaminant. In order to identify the most appropriate concentration, beef samples were spray-treated with LA (2%, 3%, 4% or 5%) or left untreated (control). Microbial load (aerobic plate counts, psychrotrophs and Enterobacteriaceae), pH, instrumental colour and sensory properties were investigated at 0, 24, 72 and 120h of refrigerated storage. The reductions in bacteria after spraying ranged from 0.57 to 0.95 log units. A residual antimicrobial effect was observed so that at 120h LA reduced microbial load by up to 2 log units compared with the control samples. Samples treated with 5% LA showed the lowest redness value (a*) and hedonic scores at all sampling times. Only for samples treated with 4% LA did the sensorial shelf-life limit extend beyond 120h. It is suggested that treatment of beef with 4% LA not only may improve microbiological quality, but also may enhance sensory properties and shelf-life. Copyright © 2017. Published by Elsevier Ltd.

Detection of Helicobacter pylori and fecal indicator bacteria in five North American rivers.

USGS Publications Warehouse

Voytek, M.A.; Ashen, J.B.; Fogarty, L.R.; Kirshtein, J.D.; Landa, E.R.

2005-01-01

This study examines the use of fecal indicator bacteria (FIB) as a predictor of the presence of Helicobacter spp. A combination of standard culture and molecular techniques were used to detect and quantify FIB, Helicobacter spp. and H. pylori from five North American rivers of different size and with different land use characteristics. Primers designed to amplify genes specific to Helicobacter spp. and H. pylori were evaluated for their efficacy in detection and quantification in environmental samples. Helicobacter spp. were detected in 18/33 (55%) of river samples. H. pylori was detected in 11/33 (33%) of river samples. FIB were found in 32/33 (96%) of river samples. When FIB abundance exceeded USEPA water quality standards for single samples, Helicobacter or H. pylori were detected in 7/15 (47%) cases. No numerical correlation was found between the presence of FIB and either Helicobacter spp. or H. pylori. This suggests that the presence of FIB will be of limited use for detection of Helicobacter spp. or H. pylori by public health agencies.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-05-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron.

Transferrin receptors in human tissues: their distribution and possible clinical relevance.

PubMed Central

Gatter, K C; Brown, G; Trowbridge, I S; Woolston, R E; Mason, D Y

1983-01-01

The distribution of transferrin receptors (TR) has been studied in a range of normal and malignant tissues using four monoclonal antibodies, BK19.9, B3/25, T56/14 and T58/1. In normal tissues TR was found in a limited number of sites, notably basal epidermis, the endocrine pancreas, hepatocytes, Kupffer cells, testis and pituitary. This restricted pattern of distribution may be relevant to the characteristic pattern of iron deposition in primary haemachromatosis. In contrast to this limited pattern of expression in normal tissue, the receptor was widely distributed in carcinomas, sarcomas and in samples from cases of Hodgkin's disease. This malignancy-associated expression of the receptor may play a role in the anaemia of advanced malignancy by competing with the bone marrow for serum iron. Images PMID:6302135

Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.

PubMed

Ilmiawati, Cimi; Thang, Nguyen Dinh; Iida, Machiko; Maeda, Masao; Ohnuma, Shoko; Yajima, Ichiro; Ohgami, Nobutaka; Oshino, Reina; Al Hossain, M M Aeorangajeb; Ninomiya, Hiromasa; Kato, Masashi

2016-12-01

Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.

Detection of Fusarium verticillioides by PCR-ELISA based on FUM21 gene.

PubMed

Omori, Aline Myuki; Ono, Elisabete Yurie Sataque; Bordini, Jaqueline Gozzi; Hirozawa, Melissa Tiemi; Fungaro, Maria Helena Pelegrinelli; Ono, Mario Augusto

2018-08-01

Fusarium verticillioides is a primary corn pathogen and fumonisin producer which is associated with toxic effects in humans and animals. The traditional methods for detection of fungal contamination based on morphological characteristics are time-consuming and show low sensitivity and specificity. Therefore, the objective of this study was to develop a PCR-ELISA based on the FUM21 gene for F. verticillioides detection. The DNA of the F. verticillioides, Fusarium sp., Aspergillus sp. and Penicillium sp. isolates was analyzed by conventional PCR and PCR-ELISA to determine the specificity. The PCR-ELISA was specific to F. verticillioides isolates, showed a 2.5 pg detection limit and was 100-fold more sensitive than conventional PCR. In corn samples inoculated with F. verticillioides conidia, the detection limit of the PCR-ELISA was 1 × 10 4 conidia/g and was also 100-fold more sensitive than conventional PCR. Naturally contaminated corn samples were analyzed by PCR-ELISA based on the FUM21 gene and PCR-ELISA absorbance values correlated positively (p < 0.05) with Fusarium sp. counts (CFU/g). These results suggest that the PCR-ELISA developed in this study can be useful for F. verticillioides detection in corn samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Physical and chemical characteristics of PM2.5 and its toxicity to human bronchial cells BEAS-2B in the winter and summer.

PubMed

Zhang, Hui-Hui; Li, Zheng; Liu, Yu; Xinag, Ping; Cui, Xin-Yi; Ye, Hui; Hu, Bao-Lan; Lou, Li-Ping

With the increasing occurrence of haze during the summer, the physicochemical characteristics and toxicity differences in PM 2.5 in different seasons are of great concern. Hangzhou is located in an area that has a subtropical monsoon climate where the humidity is very high during both the summer and winter. However, there are limited studies on the seasonal differences in PM 2.5 in these weather conditions. In this test, PM 2.5 samples were collected in the winter and summer, the morphology and chemical composition of PM 2.5 were analyzed, the toxicity of PM 2.5 to human bronchial cells BEAS-2B was compared, and the correlation between PM 2.5 toxicity and the chemical composition was discussed. The results showed that during both the winter and summer, the main compounds in the PM 2.5 samples were water-soluble ions, particularly SO 4 2- , NO 3 - , and NH 4 + , followed by organic components, while heavy metals were present at lower levels. The higher the mass concentration of PM 2.5 , the greater its impact on cell viability and ROS levels. However, when the mass concentration of PM 2.5 was similar, the water extraction from the summer samples showed a greater impact on BEAS-2B than that from the winter samples. The cytotoxicity of PM 2.5 was closely associated with heavy metals and organic pollutants but less related to water-soluble ions.

Effect of NaCl Concentration and Cooking Temperature on the Color and Pigment Characteristics of Presalted Ground Chicken Breasts

PubMed Central

Bae, Su Min; Cho, Min Guk; Hong, Gi Taek; Jeong, Jong Youn

2018-01-01

Abstract This study was conducted to determine the effects of NaCl concentration and cooking temperature on the color and pigment characteristics of presalted ground chicken breasts. Four treatments with different salt concentrations (0%, 1%, 2%, and 3%) were prepared and stored for 7 d prior to cooking. Each sample was cooked to four endpoint temperatures (70°C, 75°C, 80°C, and 85°C). The salt concentration affected the color and pigment properties of the cooked ground chicken breasts. As the salt concentration increased, the cooking yield and residual nitrite content also increased. However, the samples with 1%, 2%, and 3% NaCl showed similar nitrosyl hemochrome and total pigment contents. Among the products containing salt, the samples with 3% NaCl showed the lowest percentage myoglobin denaturation (PMD) and the lowest CIE a* values. The cooking temperature had limited effects on the pigment properties of cooked ground chicken breasts. The oxidation-reduction potential and residual nitrite contents increased with cooking temperature, while the PMD, nitrosyl hemochrome, total pigment contents and CIE a* values were similar in the samples cooked at different temperatures. These results indicated that the addition of up to 2% salt to ground chicken breasts and storage for 7 d could cause the pink color defect of cooked products. However, the addition of 3% NaCl could reduce the redness of the cooked products. PMID:29805289

A post-mortem survey on end-of-life decisions using a representative sample of death certificates in Flanders, Belgium: research protocol

PubMed Central

Chambaere, Kenneth; Bilsen, Johan; Cohen, Joachim; Pousset, Geert; Onwuteaka-Philipsen, Bregje; Mortier, Freddy; Deliens, Luc

2008-01-01

Background Reliable studies of the incidence and characteristics of medical end-of-life decisions with a certain or possible life shortening effect (ELDs) are indispensable for an evidence-based medical and societal debate on this issue. This article presents the protocol drafted for the 2007 ELD Study in Flanders, Belgium, and outlines how the main aims and challenges of the study (i.e. making reliable incidence estimates of end-of-life decisions, even rare ones, and describing their characteristics; allowing comparability with past ELD studies; guaranteeing strict anonymity given the sensitive nature of the research topic; and attaining a sufficient response rate) are addressed in a post-mortem survey using a representative sample of death certificates. Study design Reliable incidence estimates are achievable by using large at random samples of death certificates of deceased persons in Flanders (aged one year or older). This entails the cooperation of the appropriate administrative authorities. To further ensure the reliability of the estimates and descriptions, especially of less prevalent end-of-life decisions (e.g. euthanasia), a stratified sample is drawn. A questionnaire is sent out to the certifying physician of each death sampled. The questionnaire, tested thoroughly and avoiding emotionally charged terms is based largely on questions that have been validated in previous national and European ELD studies. Anonymity of both patient and physician is guaranteed through a rigorous procedure, involving a lawyer as intermediary between responding physicians and researchers. To increase response we follow the Total Design Method (TDM) with a maximum of three follow-up mailings. Also, a non-response survey is conducted to gain insight into the reasons for lack of response. Discussion The protocol of the 2007 ELD Study in Flanders, Belgium, is appropriate for achieving the objectives of the study; as past studies in Belgium, the Netherlands, and other European countries have shown, strictly anonymous and thorough surveys among physicians using a large, stratified, and representative death certificate sample are most suitable in nationwide studies of incidence and characteristics of end-of-life decisions. There are however also some limitations to the study design. PMID:18752659

Comparison of fuel value and combustion characteristics of two different RDF samples.

PubMed

Sever Akdağ, A; Atımtay, A; Sanin, F D

2016-01-01

Generation of Municipal Solid Waste (MSW) tends to increase with the growing population and economic development of the society; therefore, establishing environmentally sustainable waste management strategies is crucial. In this sense, waste to energy strategies have come into prominence since they increase the resource efficiency and replace the fossil fuels with renewable energy sources by enabling material and energy recovery instead of landfill disposal of the wastes. Refuse Derived Fuel (RDF), which is an alternative fuel produced from energy-rich Municipal Solid Waste (MSW) materials diverted from landfills, is one of the waste to energy strategies gaining more and more attention. This study aims to investigate the thermal characteristics and co-combustion efficiency of two RDF samples in Turkey. Proximate, ultimate and thermogravimetric analyses (TGA) were conducted on these samples. Furthermore, elemental compositions of ash from RDF samples were determined by X-Ray Fluorescence (XRF) analysis. The RDF samples were combusted alone and co-combusted in mixtures with coal and petroleum coke in a lab scale reactor at certain percentages on energy basis (3%, 5%, 10%, 20% and 30%) where co-combustion processes and efficiencies were investigated. It was found that the calorific values of RDF samples on dry basis were close to that of coal and a little lower compared to petroleum coke used in this study. Furthermore, the analysis indicated that when RDF in the mixture was higher than 10%, the CO concentration in the flue gas increased and so the combustion efficiency decreased; furthermore, the combustion characteristics changed from char combustion to volatile combustion. However, RDF addition to the fuel mixtures decreased the SO2 emission and did not change the NOx profiles. Also, XRF analysis showed that the slagging and fouling potential of RDF combustion was a function of RDF portion in fuel blend. When the RDF was combusted alone, the slagging and fouling indices of its ash were found to be higher than the limit values producing slagging and fouling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Association of low back pain on physical, sociodemographic and lifestyle factors across a general population sample within Greece.

PubMed

Billis, E; Koutsojannis, C; Matzaroglou, C; Gliatis, J; Fousekis, K; Gioftsos, G; Papandreou, M; McCarthy, C; Oldham, J A; Tsepis, E

2017-01-01

Although low back pain (LBP) is a debilitating problem internationally, there is not a lot of research on its impact on physical, psychosocial and lifestyle factors. Especially in mediterranean countries, such as Greece, it is not sufficiently explored whether physical (pain location, activity limitation etc.), sociodemographic (education, smoking etc.) or lifestyle factors (i.e. quality of life or anxiety) are influenced by LBP. To estimate LBP prevalence in the Greek general population and explore its association with particular sociodemographic, physical and lifestyle factors. A sample of 3125 people of the Greek adult population was randomly selected by stratified sampling encompassing rural and urban representation within the Greek mainland. An extended survey form was developed entailing three sections; personal (sociodemographic) information, questions on symptomatology and physical factors (i.e. pain characteristics, recurrence, physical disability etc.) and 3 self-administered questionnaires (including mostly lifestyle factors); Hospital Anxiety and Depression (HAD) scale for anxiety and depression, SF-12 for quality of life (QoL) and Roland-Morris for disability. A total of 471 (15%) people reported LBP (210 males, mean age: 47.04 ± 15.03). Amongst them 60% reported sciatica, 76% suffered recurrent LBP and 70% received specialist care. Low disability levels, moderate to high pain intensity, gender differences and good self-reported QoL and psychosocial status were reported. Sociodemographic characteristics (income, smoking, marital status etc.) were not associated with LBP physical factors, apart from age which correlated with physical disability and wellness (r being 0.446 and 0.405, respectively, p< 0.001). Physical factors (particularly pain intensity and location) correlated with lifestyle factors (QoL) and disability (r ranging between 0.396 and 0.543, p< 0.001). Mental wellness, anxiety and depression (as lifestyle factors) were not associated with sociodemographic or physical factors. Physical parameters were amongst the most prevalent characteristics of the Greek sample, thus offering a direction towards a more targeted treatment and rehabilitation planning. Unlike previous literature, most sociodemographic characteristics were not correlated with any LBP physical or lifestyle factors, thus possibly indicating a different socioeconomic background and aetiology domain to that of the usual non-specific LBP spectrum.

Physical properties of Jupiter-family comets and KBOs from ground-based lightcurve observations

NASA Astrophysics Data System (ADS)

Kokotanekova, Rosita; Snodgrass, Colin; Lacerda, Pedro; Green, Simon F.

2017-10-01

Rotational lightcurves are among the most powerful tools to study the physical characteristics of small bodies in the Solar system. They can be used to constrain their spin rates, shapes, densities and compositions. We have developed a method to derive precise lightcurves and phase functions from sparsely sampled data, calibrated using Pan-STARRS stellar magnitudes. We employ this technique to characterize the physical properties of Jupiter Family Comets (JFCs) and Kuiper Belt Objects (KBOs).We provide an updated study of the collective properties of JFCs by increasing the sample of comets with well-studied rotational and surface characteristics. To collect the sample, we reviewed the properties of 35 previously-studied JFCs and added new lightcurves and phase functions for nine JFCs observed between 2004 and 2015.The new extended sample confirms the known cut-off in bulk density at ˜0.6 g cm-3 if JFCs are strengthless. For typical density and elongations, we determined that JFCs require tensile strength of 10-25 Pa to remain stable against rotational instabilities. To provide further constraints on the physical characteristics of JFCs we combine these findings with a study of the activity-induced spin changes of JFCs. Using the newly derived albedos and phase functions, we found that the median linear phase function coefficient for JFCs is 0.046 mag/deg and the median albedo is 4.2 per cent. We found evidence for an increasing linear phase function coefficient with increasing albedo.In an attempt to relate JFCs to their source populations, we compare them to KBOs. We performed a magnitude-limited survey of 40 KBOs, observed with the 3.6-m ESO New Technology Telescope between 2014 and 2017. This is the first survey with a 4m-class telescope conducted in an entirely homogeneous manner (using the same telescope, observing strategy, and data analysis). This program allows us to relate the rotation rates, physical properties and surface characteristics of JFCs and KBOs in order to test the different hypotheses for their formation and subsequent evolution.

Approaches to Recruiting ‘Hard-To-Reach’ Populations into Re­search: A Review of the Literature

PubMed Central

Shaghaghi, Abdolreza; Bhopal, Raj S; Sheikh, Aziz

2011-01-01

Background: ‘Hard-to-reach’ is a term used to describe those sub-groups of the population that may be difficult to reach or involve in research or public health programmes. Application of a single term to call these sub-sections of populations implies a homogeneity within distinct groups, which does not necessarily exist. Different sampling techniques were introduced so far to recruit hard-to-reach populations. In this article, we have reviewed a range of ap­proaches that have been used to widen participation in studies. Methods: We performed a Pubmed and Google search for relevant English language articles using the keywords and phrases: (hard-to-reach AND population* OR sampl*), (hidden AND population* OR sample*) and (“hard to reach” AND population* OR sample*) and a consul­tation of the retrieved articles’ bibliographies to extract empirical evidence from publications that discussed or examined the use of sampling techniques to recruit hidden or hard-to-reach populations in health studies. Results: Reviewing the literature has identified a range of techniques to recruit hard-to-reach populations, including snowball sampling, respondent-driven sampling (RDS), indigenous field worker sampling (IFWS), facility-based sampling (FBS), targeted sampling (TS), time-location (space) sampling (TLS), conventional cluster sampling (CCS) and capture re-capture sampling (CR). Conclusion: The degree of compliance with a study by a certain ‘hard-to-reach’ group de­pends on the characteristics of that group, recruitment technique used and the subject of inter­est. Irrespective of potential advantages or limitations of the recruitment techniques reviewed, their successful use depends mainly upon our knowledge about specific characteristics of the target populations. Thus in line with attempts to expand the current boundaries of our know­ledge about recruitment techniques in health studies and their applications in varying situa­tions, we should also focus on possibly all contributing factors which may have an impact on participation rate within a defined population group. PMID:24688904

Investigation of disorder and its effect on electrical transport in electrochemically doped polymer devices by current-voltage and impedance spectroscopy

NASA Astrophysics Data System (ADS)

Rahman Khan, Motiur; Anjaneyulu, P.; Koteswara Rao, K. S. R.; Menon, R.

2017-03-01

We report on the analysis of temperature-dependent current-voltage characteristics and impedance measurements of electrochemically doped poly(3-methylthiophene) devices at different doping levels. The extent of doping is carefully tailored such that only the bulk-limited transport mechanism prevails. A transition from exponentially distributed trap-limited transport to trap-free space-charge-limited current is observed in current-voltage conduction upon increasing the doping. The obtained trap densities (3.2  ×  1016 cm-3 and 8.6  ×  1015 cm-3) and trap energies (31.7 meV and 16.6 meV) for different devices signify the variation in disorder with doping, which is later supported by impedance measurements. Impedance-frequency data for various devices can not be explained using the parallel resistance-capacitance (RC) model in the equivalent circuit. However, this was established by incorporating a constant phase element Q (CPE) instead of the capacitance parameter. It should be emphasized that low doping devices in particular are best simulated with two CPE elements, while the data related to other devices are fitted well with a single CPE element. It is also observed from evaluated circuit parameters that the spatial inhomogeneity and disorder are the cause of variability in different samples, which has an excellent correlation with the temperature-dependent current-voltage characteristics.

Soil strength and macropore volume limit root elongation rates in many UK agricultural soils.

PubMed

Valentine, Tracy A; Hallett, Paul D; Binnie, Kirsty; Young, Mark W; Squire, Geoffrey R; Hawes, Cathy; Bengough, A Glyn

2012-07-01

Simple indicators of crop and cultivar performance across a range of soil types and management are needed for designing and testing sustainable cropping practices. This paper determined the extent to which soil chemical and physical properties, particularly soil strength and pore-size distribution influences root elongation in a wide range of agricultural top soils, using a seedling-based indicator. Intact soil cores were sampled from the topsoil of 59 agricultural fields in Scotland, representing a wide geographic spread, range of textures and management practices. Water release characteristics, dry bulk density and needle penetrometer resistance were measured on three cores from each field. Soil samples from the same locations were sieved, analysed for chemical characteristics, and packed to dry bulk density of 1.0 g cm(-3) to minimize physical constraints. Root elongation rates were determined for barley seedlings planted in both intact field and packed soil cores at a water content close to field capacity (-20 kPa matric potential). Root elongation in field soil was typically less than half of that in packed soils. Penetrometer resistance was typically between 1 and 3 MPa for field soils, indicating the soils were relatively hard, despite their moderately wet condition (compared with <0.2 MPa for packed soil). Root elongation was strongly linked to differences in physical rather than chemical properties. In field soil root elongation was related most closely to the volume of soil pores between 60 µm and 300 µm equivalent diameter, as estimated from water-release characteristics, accounting for 65.7 % of the variation in the elongation rates. Root elongation rate in the majority of field soils was slower than half of the unimpeded (packed) rate. Such major reductions in root elongation rates will decrease rooting volumes and limit crop growth in soils where nutrients and water are scarce.

Three-Dimensional Quantification of Pore Space in Flocculated Sediments

NASA Astrophysics Data System (ADS)

Lawrence, Tom; Spencer, Kate; Bushby, Andy; Manning, Andrew

2017-04-01

Flocculated sediment structure plays a vital role in determining sediment dynamics within the water column in fresh and saline water bodies. The porosity of flocs contributes to their specific density and therefore their settling characteristics, and can also affect settling characteristics via through-flow. The process of settling and resuspension of flocculated material causes the formation of larger and more complex individual flocs, about which little is known quantitatively of the internal micro-structure and therefore porosity. Hydrological and sedimentological modelling software currently uses estimations of porosity, because it is difficult to capture and analyse flocs. To combat this, we use a novel microscopy method usually performed on biological material to scan the flocs, the output of which can be used to quantify the dimensions and arrangement of pores. This involves capturing flocculated sediment, staining the sample with heavy metal elements to highlight organic content in the Scanning Electron Microscope later, and finally setting the sample in resin. The overall research aim is to quantitatively characterise the dimensions and distribution of pore space in flocs in three dimensions. In order to gather data, Scanning Electron Microscopy and micro-Computed Tomography have been utilised to produce the necessary images to identify and quantify the pore space. The first objective is to determine the dimensional limits of pores in the structure (i.e. what area do they encapsulate? Are they interconnected or discreet?). This requires a repeatable definition to be established, so that all floc pore spaces can be quantified using the same parameters. The LabSFLOC settling column and dyes will be used as one possible method of determining the outer limits of the discreet pore space. LabSFLOC is a sediment settling column that uses a camera to record the flocs, enabling analysis of settling characteristics. The second objective is to develop a reliable method for quantifying the dimensions of the pores. The dimensions to be quantified are the long- and short-axis lengths, measured using ImageJ. The third objective will be to quantify the distribution of the pore space within the structure, utilising point-to-point measurements and distance from centre of the floc, again utilising software capable of providing accurate measurements between the centres of each pore within the structure. Preliminary data demonstrating pore dimensional limits and quantification will be presented. This will establish a definition of pore space based on limits of interaction between pore water and the water column, including experimental data from LabSFLOC, and visual representations of pore outer limits. Further to this, I will include some investigational data from ImageJ relating to the dimensions being measured for sub-aim 2. This information is vital in providing accurate and reliable information for hydrological and sedimentological model input, ultimately increasing the value of the outputs.

Adaptive Sampling of Time Series During Remote Exploration

NASA Technical Reports Server (NTRS)

Thompson, David R.

2012-01-01

This work deals with the challenge of online adaptive data collection in a time series. A remote sensor or explorer agent adapts its rate of data collection in order to track anomalous events while obeying constraints on time and power. This problem is challenging because the agent has limited visibility (all its datapoints lie in the past) and limited control (it can only decide when to collect its next datapoint). This problem is treated from an information-theoretic perspective, fitting a probabilistic model to collected data and optimizing the future sampling strategy to maximize information gain. The performance characteristics of stationary and nonstationary Gaussian process models are compared. Self-throttling sensors could benefit environmental sensor networks and monitoring as well as robotic exploration. Explorer agents can improve performance by adjusting their data collection rate, preserving scarce power or bandwidth resources during uninteresting times while fully covering anomalous events of interest. For example, a remote earthquake sensor could conserve power by limiting its measurements during normal conditions and increasing its cadence during rare earthquake events. A similar capability could improve sensor platforms traversing a fixed trajectory, such as an exploration rover transect or a deep space flyby. These agents can adapt observation times to improve sample coverage during moments of rapid change. An adaptive sampling approach couples sensor autonomy, instrument interpretation, and sampling. The challenge is addressed as an active learning problem, which already has extensive theoretical treatment in the statistics and machine learning literature. A statistical Gaussian process (GP) model is employed to guide sample decisions that maximize information gain. Nonsta tion - ary (e.g., time-varying) covariance relationships permit the system to represent and track local anomalies, in contrast with current GP approaches. Most common GP models are stationary, e.g., the covariance relationships are time-invariant. In such cases, information gain is independent of previously collected data, and the optimal solution can always be computed in advance. Information-optimal sampling of a stationary GP time series thus reduces to even spacing, and such models are not appropriate for tracking localized anomalies. Additionally, GP model inference can be computationally expensive.

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

Junginger, Tobias; Abidi, S. H.; Maffett, R. D.

Here, the performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry H entry and pinning strength. The former sets the limit for the maximum achievable accelerating gradient, while the latter determines how efficiently flux can be expelled related to the maximum achievable quality factor. In this paper, a method based on muon spin rotation (μSR) is developed to probe these parameters on samples. It combines measurements from two different spectrometers, one being specifically built for these studies and samples of different geometries. It is found that annealing atmore » 1400°C virtually eliminates all pinning. Such an annealed substrate is ideally suited to measure H entry of layered superconductors, which might enable accelerating gradients beyond bulk niobium technology.« less

Identification Of Cells With A Compact Microscope Imaging System With Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2006-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking mic?oscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

Tracking of Cells with a Compact Microscope Imaging System with Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2007-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously

Tracking of cells with a compact microscope imaging system with intelligent controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2007-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to auto-focus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

Operation of a Cartesian Robotic System in a Compact Microscope with Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2006-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

A Post-Processing Receiver for the Lunar Laser Communications Demonstration Project

NASA Technical Reports Server (NTRS)

Srinivasan, Meera; Birnbaum, Kevin; Cheng, Michael; Quirk, Kevin

2013-01-01

The Lunar Laser Communications Demonstration Project undertaken by MIT Lincoln Laboratory and NASA's Goddard Space Flight Center will demonstrate high-rate laser communications from lunar orbit to the Earth. NASA's Jet Propulsion Laboratory is developing a backup ground station supporting a data rate of 39 Mbps that is based on a non-real-time software post-processing receiver architecture. This approach entails processing sample-rate-limited data without feedback in the presence high uncertainty in downlink clock characteristics under low signal flux conditions. In this paper we present a receiver concept that addresses these challenges with descriptions of the photodetector assembly, sample acquisition and recording platform, and signal processing approach. End-to-end coded simulation and laboratory data analysis results are presented that validate the receiver conceptual design.

Appraisal of ground-water quality near wastewater-treatment facilities, Glacier National Park, Montana

USGS Publications Warehouse

Moreland, Joe A.; Wood, Wayne A.

1982-01-01

Water-level and water-quality data were collected from monitoring wells at wastewater-treatment facilities in Glacier National Park. Five additional shallow observation wells were installed at the Glacier Park Headquarters facility to monitor water quality in the shallow ground-water system.Water-level, water-quality, and geologic information indicate that some of the initial monitoring wells are not ideally located to sample ground water most likely to be affected by waste disposal at the sites. Small differences in chemical characteristics between samples from monitor wells indicate that effluent may be affecting ground-water quality but that impacts are not significant.Future monitoring of ground-water quality could be limited to selected wells most likely to be impacted by percolating effluent. Laboratory analyses for common ions could detect future impacts.

Understanding entrepreneurial intent in late adolescence: the role of intentional self-regulation and innovation.

PubMed

Geldhof, G John; Weiner, Michelle; Agans, Jennifer P; Mueller, Megan K; Lerner, Richard M

2014-01-01

Entrepreneurship represents a form of adaptive developmental regulation through which both entrepreneurs and their ecologies benefit. We describe entrepreneurship from the perspective of relational developmental systems theory, and examine the joint role of personal attributes, contextual attributes, and characteristics of person-context relationships in predicting entrepreneurial intent in a sample 3,461 college students enrolled in colleges and universities in the United States (60 % female; 61 % European American). Specifically, we tested whether personal characteristics (i.e., gender, intentional self-regulation skills, innovation orientation) and contextual factors (i.e., entrepreneurial parents) predicted college students' intentions to pursue an entrepreneurial career. Our findings suggest that self-regulation, innovation orientation, and having entrepreneurial role models (i.e., parents) predict entrepreneurial intent. Limitations and future directions for the study of youth entrepreneurship are discussed.

Comparison of self-reported and audiometrically-measured hearing loss in the Australian Defence Force.

PubMed

Kirk, Katherine M; McGuire, Annabel; Nasveld, Peter E; Treloar, Susan A

2012-04-01

To investigate the relationship between self-reported and audiometrically-measured hearing loss in a sample of Australian Defence Force personnel. Responses to a question regarding hearing problems were compared with contemporaneous audiometric data. 3335 members of the Australian Defence Force for whom anonymised medical records were available. The sensitivity of self-report data to identify higher-frequency hearing loss was lower than sensitivity at other frequencies, and positive predictive values were moderate to poor at all frequencies. Performance characteristics of self-report compared with audiometric data also varied with age, sex, and rank. While self-report hearing loss data have good performance characteristics for estimating prevalence of hearing loss as defined by audiometric criteria, this study indicates that the usefulness of self-report data in identifying individuals with hearing loss may be limited in this population.

Emergency department overcrowding: the impact of resource scarcity on physician job satisfaction.

PubMed

Rondeau, Kent V; Francescutti, Louis H

2005-01-01

Emergency departments in most developed countries have been experiencing significant overcrowding under a regime of severe resource constraints. Physicians in emergency departments increasingly find themselves toiling in workplaces that are characterized by diminished availability of, limited access to, and decreased stability of critical resources. Severe resource constraints have the potential to greatly weaken the overall job satisfaction of emergency physicians. This article examines the impact of hospital resource constraints on the job satisfaction of a large sample of emergency physicians in Canada. After controlling for workflow and patient characteristics and for various institutional and physician characteristics, institutional resource constraints are found to be major contributors to emergency physician job dissatisfaction. Resource factors that have the greatest impact on job satisfaction include availability of emergency room physicians, access to hospital technology and emergency beds, and stability of financial (investment) resources.

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

Sobolewska, M. A.; Siemiginowska, A.; Kelly, B. C.

We study the γ-ray variability of 13 blazars observed with the Fermi/Large Area Telescope (LAT). These blazars have the most complete light curves collected during the first four years of the Fermi sky survey. We model them with the Ornstein-Uhlenbeck (OU) process or a mixture of the OU processes. The OU process has power spectral density (PSD) proportional to 1/f {sup α} with α changing at a characteristic timescale, τ{sub 0}, from 0 (τ >> τ{sub 0}) to 2 (τ << τ{sub 0}). The PSD of the mixed OU process has two characteristic timescales and an additional intermediate region withmore » 0 < α < 2. We show that the OU model provides a good description of the Fermi/LAT light curves of three blazars in our sample. For the first time, we constrain a characteristic γ-ray timescale of variability in two BL Lac sources, 3C 66A and PKS 2155-304 (τ{sub 0} ≅ 25 days and τ{sub 0} ≅ 43 days, respectively, in the observer's frame), which are longer than the soft X-ray timescales detected in blazars and Seyfert galaxies. We find that the mixed OU process approximates the light curves of the remaining 10 blazars better than the OU process. We derive limits on their long and short characteristic timescales, and infer that their Fermi/LAT PSD resemble power-law functions. We constrain the PSD slopes for all but one source in the sample. We find hints for sub-hour Fermi/LAT variability in four flat spectrum radio quasars. We discuss the implications of our results for theoretical models of blazar variability.« less

Fathers and mothers with eating-disorder psychopathology: Associations with child eating-disorder behaviors.

PubMed

Lydecker, Janet A; Grilo, Carlos M

2016-07-01

A limited literature suggests an association between maternal eating disorders and child feeding difficulties, and notes maternal concern about inadvertently transmitting eating disorders. Thus, parents may be an important target for eating-disorder research to guide the development of clinical programs. The current study examined differences in child eating-disorder behaviors and parental feeding practices between a sample of parents (42 fathers, 130 mothers) exhibiting core features of anorexia nervosa, bulimia nervosa, binge-eating disorder, or purging disorder, and a matched sample of parents (n=172) reporting no eating-disorder characteristics. Parents with eating-disorder psychopathology were significantly more likely than parents without eating-disorder characteristics to report child binge-eating and compulsive exercise. Parents with eating-disorder psychopathology reported greater perceived feeding responsibility, greater concern about their child's weight, and more monitoring of their child's eating than parents without eating-disorder characteristics; however, they did not differ significantly in restriction of their child's diet and pressure-to-eat. Child body mass index z-scores did not differ between parents with versus without eating-disorder characteristics. Our findings suggest some important differences between parents with and without core eating-disorder psychopathology, which could augment clinical interventions for patients with eating disorders who are parents, or could guide pediatric eating-disorder prevention efforts. However, because our study was cross-sectional, findings could indicate increased awareness of or sensitivity to eating-disorder behaviors rather than a psychosocial cause of those behaviors. Longitudinal research and controlled trials examining prevention and intervention can clarify and address these clinical concerns. Copyright © 2016 Elsevier Inc. All rights reserved.

Fathers and mothers with eating-disorder psychopathology: Associations with child eating-disorder behaviors

PubMed Central

Lydecker, Janet A.; Grilo, Carlos M.

2016-01-01

Objective A limited literature suggests an association between maternal eating disorders and child feeding difficulties, and notes maternal concern about inadvertently transmitting eating disorders. Thus, parents may be an important target for eating-disorder research to guide the development of clinical programs. Methods The current study examined differences in child eating-disorder behaviors and parental feeding practices between a sample of parents (42 fathers, 130 mothers) exhibiting core features of anorexia nervosa, bulimia nervosa, binge-eating disorder, or purging disorder, and a matched sample of parents (n=172) reporting no eating-disorder characteristics. Results Parents with eating-disorder psychopathology were significantly more likely than parents without eating-disorder characteristics to report child binge-eating and compulsive exercise. Parents with eating-disorder psychopathology reported greater perceived feeding responsibility, greater concern about their child’s weight, and more monitoring of their child’s eating than parents without eating-disorder characteristics; however, they did not differ significantly in restriction of their child’s diet and pressure-to-eat. Child body mass index z-scores did not differ between parents with versus without eating-disorder characteristics. Conclusion Our findings suggest some important differences between parents with and without core eating-disorder psychopathology, which could augment clinical interventions for patients with eating disorders who are parents, or could guide pediatric eating-disorder prevention efforts. However, because our study was cross-sectional, findings could indicate increased awareness of or sensitivity to eating-disorder behaviors rather than a psychosocial cause of those behaviors. Longitudinal research and controlled trials examining prevention and intervention can clarify and address these clinical concerns. PMID:27302549

Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

USGS Publications Warehouse

Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

1995-01-01

The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.

Comparison of chain sampling plans with single and double sampling plans

NASA Technical Reports Server (NTRS)

Stephens, K. S.; Dodge, H. F.

1976-01-01

The efficiency of chain sampling is examined through matching of operating characteristics (OC) curves of chain sampling plans (ChSP) with single and double sampling plans. In particular, the operating characteristics of some ChSP-0, 3 and 1, 3 as well as ChSP-0, 4 and 1, 4 are presented, where the number pairs represent the first and the second cumulative acceptance numbers. The fact that the ChSP procedure uses cumulative results from two or more samples and that the parameters can be varied to produce a wide variety of operating characteristics raises the question whether it may be possible for such plans to provide a given protection with less inspection than with single or double sampling plans. The operating ratio values reported illustrate the possibilities of matching single and double sampling plans with ChSP. It is shown that chain sampling plans provide improved efficiency over single and double sampling plans having substantially the same operating characteristics.

UV Absorption Spectroscopy in Water-Filled Antiresonant Hollow Core Fibers for Pharmaceutical Detection.

PubMed

Nissen, Mona; Doherty, Brenda; Hamperl, Jonas; Kobelke, Jens; Weber, Karina; Henkel, Thomas; Schmidt, Markus A

2018-02-06

Due to a worldwide increased use of pharmaceuticals and, in particular, antibiotics, a growing number of these substance residues now contaminate natural water resources and drinking supplies. This triggers a considerable demand for low-cost, high-sensitivity methods for monitoring water quality. Since many biological substances exhibit strong and characteristic absorption features at wavelengths shorter than 300 nm, UV spectroscopy presents a suitable approach for the quantitative identification of such water-contaminating species. However, current UV spectroscopic devices often show limited light-matter interaction lengths, demand sophisticated and bulky experimental infrastructure which is not compatible with microfluidics, and leave large fractions of the sample analyte unused. Here, we introduce the concept of UV spectroscopy in liquid-filled anti-resonant hollow core fibers, with large core diameters and lengths of approximately 1 m, as a means to overcome such limitations. This extended light-matter interaction length principally improves the concentration detection limit by two orders of magnitude while using almost the entire sample volume-that is three orders of magnitude smaller compared to cuvette based approaches. By integrating the fibers into an optofluidic chip environment and operating within the lowest experimentally feasible transmission band, concentrations of the application-relevant pharmaceutical substances, sulfamethoxazole (SMX) and sodium salicylate (SS), were detectable down to 0.1 µM (26 ppb) and 0.4 µM (64 ppb), respectively, with the potential to reach significantly lower detection limits for further device integration.

UV Absorption Spectroscopy in Water-Filled Antiresonant Hollow Core Fibers for Pharmaceutical Detection

PubMed Central

Nissen, Mona; Doherty, Brenda; Hamperl, Jonas; Kobelke, Jens; Weber, Karina; Henkel, Thomas; Schmidt, Markus A.

2018-01-01

Due to a worldwide increased use of pharmaceuticals and, in particular, antibiotics, a growing number of these substance residues now contaminate natural water resources and drinking supplies. This triggers a considerable demand for low-cost, high-sensitivity methods for monitoring water quality. Since many biological substances exhibit strong and characteristic absorption features at wavelengths shorter than 300 nm, UV spectroscopy presents a suitable approach for the quantitative identification of such water-contaminating species. However, current UV spectroscopic devices often show limited light-matter interaction lengths, demand sophisticated and bulky experimental infrastructure which is not compatible with microfluidics, and leave large fractions of the sample analyte unused. Here, we introduce the concept of UV spectroscopy in liquid-filled anti-resonant hollow core fibers, with large core diameters and lengths of approximately 1 m, as a means to overcome such limitations. This extended light-matter interaction length principally improves the concentration detection limit by two orders of magnitude while using almost the entire sample volume—that is three orders of magnitude smaller compared to cuvette based approaches. By integrating the fibers into an optofluidic chip environment and operating within the lowest experimentally feasible transmission band, concentrations of the application-relevant pharmaceutical substances, sulfamethoxazole (SMX) and sodium salicylate (SS), were detectable down to 0.1 µM (26 ppb) and 0.4 µM (64 ppb), respectively, with the potential to reach significantly lower detection limits for further device integration. PMID:29415468

Wide-field surface plasmon microscopy of nano- and microparticles: features, benchmarking, limitations, and bioanalytical applications

NASA Astrophysics Data System (ADS)

Nizamov, Shavkat; Scherbahn, Vitali; Mirsky, Vladimir M.

2017-05-01

Detection of nano- and micro-particles is an important task for chemical analytics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals in surface plasmon resonance images due to adsorption of single nanopartciles was developed. This new technology allows one a real-time detection of interaction of single nano- and micro-particles with sensor surface. Adsorption of each nanoparticle leads to characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The adsorption rate characterizes volume concentration of nano- and micro-particles. Large monitored surface area of sensor enables a high dynamic range of counting and to a correspondingly high dynamic range in concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 particles per microliter. For application of method in complex media, nanoparticle images are discriminated from image perturbations due to matrix components. First, the characteristic SPRM images of nanoparticles (templates) are collected in aqueous suspensions or spiked real samples. Then, the detection of nanoparticles in complex media using template matching is performed. The detection of various NPs in consumer products like cosmetics, mineral water, juices, and wines was shown at sub-ppb level. The method can be applied for ultrasensitive detection and analysis of nano- and micro-particles of biological (bacteria, viruses, endosomes), biotechnological (liposomes, protein nanoparticles for drug delivery) or technical origin.

Geotechnical and mineralogical characteristics of marl deposits in Jordan

NASA Astrophysics Data System (ADS)

Shaqour, Fathi M.; Jarrar, Ghaleb; Hencher, Steve; Kuisi, Mostafa

2008-10-01

Marls and marly limestone deposits cover most of Northern Jordan, where Amman City and its suburbs are located. These deposits serve as foundations for most buildings and roads as well as fill material for structural back filling, especially road bases and sub-bases. The present study aims at investigating the geotechnical characteristics and mineral composition of the marl units of these deposits through field investigations and laboratory testing. Using X-ray diffraction technique along with chemical analysis, representative samples of marl horizons were tested for mineral composition, and for a set of index and geotechnical properties including: specific gravity, grain size, Atterberg limits, Proctor compaction and shear strength properties. The test results show a positive linear relationship as expected between the clay content and both liquid and plastic limits. The tests results also show an inverse linear relationship between the clay content and the maximum dry density in both standard and modified compaction. This is attributed to the adsorption of water by the clay minerals. The relationship is more prominent in the case of modified compaction test. The results also indicate a similar relationship for the angle of internal friction. No clear correlation between cohesion and clay content was apparent.

[Emission characteristics and safety evaluation of volatile organic compounds in manufacturing processes of automotive coatings].

PubMed

Zeng, Pei-Yuan; Li, Jian-Jun; Liao, Dong-Qi; Tu, Xiang; Xu, Mei-Ying; Sun, Guo-Ping

2013-12-01

Emission characteristics of volatile organic compounds (VOCs) were investigated in an automotive coating manufacturing enterprise. Air samples were taken from eight different manufacturing areas in three workshops, and the species of VOCs and their concentrations were measured by gas chromatography-mass spectrometry (GC-MS). Safety evaluation was also conducted by comparing the concentration of VOCs with the permissible concentration-short term exposure limit (PC-STEL) regulated by the Ministry of Health. The results showed that fifteen VOCs were detected in the indoor air of the automotive coatings workshop, including benzene, toluene, ethylbenzene, xylene, ethyl acetate, butyl acetate, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, trimethylbenzene and ethylene glycol monobutyl ether, Their concentrations widely ranged from 0.51 to 593.14 mg x m(-3). The concentrations of TVOCs were significantly different among different manufacturing processes. Even in the same manufacturing process, the concentrations of each component measured at different times were also greatly different. The predominant VOCs of indoor air in the workshop were identified to be ethylbenzene and butyl acetate. The concentrations of most VOCs exceeded the occupational exposure limits, so the corresponding control measures should be taken to protect the health of the workers.

Optical design of CCAT

NASA Astrophysics Data System (ADS)

Cortés-Medellín, Germán; Herter, Terry

2006-06-01

The Cornell Caltech Atacama Telescope (CCAT) is a 25m-class sub-millimeter radio telescope capable of operating from 300GHz up to 1.5 THz. The CCAT optical design is an f/8 Ritchey-Chretien (RC) system in a dual Nasmyth focus configuration and a 20 arc-min FOV (diffraction limited imaging performance better than 0.31" at the edge of the field). The large FOV is capable to accommodate up to 1200x1200 (Nyquist Sampled) Pixels at 200 microns, with better than 96% Strehl ratio. The telescope pedestal assembly is a counterbalanced elevation over azimuth design. The main reflector surface is segmented and actively controlled to attain diffraction-limited operation up to 200 microns. A flat Mirror located behind the main reflector vertex provides the optical path relay to either of the two Nasmyth platforms and to a bent-Cassegrain focus for surface calibration. We present the imaging characteristics of the CCAT over the 20arc-min FOV at 200 microns at the Nasmyth focal plane, as well as the positioning sensitivity analysis of CCAT's 3.2m-diameter sub-reflector given in terms of the telescope optical performance, antenna pointing requirements and sub-reflector chopping characteristics.

Residual Agar Determination in Bacterial Spores by Electrospray Ionization Mass Spectrometry

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

Wahl, Karen L.; Colburn, Heather A.; Wunschel, David S.

2010-02-15

Presented here is an analytical method to detect residual agar from a bacterial spore sample as an indication of culturing on an agar plate. This method is based on the resolubilization of agar polysaccharide from a bacterial spore sample, enzymatic digestion, followed by electrospray ionization tandem mass spectrometry (ESI-MSn) analysis for detection of a specific agar fragment ion. A range of Bacillus species and strains were selected to demonstrate the effectiveness of this approach. The characteristic agar fragment ion was detected in the spores grown on agar that were washed from 1 to 5 times, irradiated or non-irradiated and notmore » in the spores grown in broth. A sample containing approximately 108 spores is currently needed for confident detection of residual agar from culture on agar plates in the presence of bacterial spores with a limit of detection of approximately 1 ppm agar spiked into a broth-grown spore sample. The results of a proficiency test with 42 blinded samples are presented demonstrating the utility of this method with no false positives and only 3 false negatives for samples that were below the detection level of the method as documented.« less

Applying Flammability Limit Probabilities and the Normoxic Upward Limiting Pressure Concept to NASA STD-6001 Test 1

NASA Technical Reports Server (NTRS)

Olson, Sandra L.; Beeson, Harold; Fernandez-Pello, A. Carlos

2014-01-01

Repeated Test 1 extinction tests near the upward flammability limit are expected to follow a Poisson process trend. This Poisson process trend suggests that rather than define a ULOI and MOC (which requires two limits to be determined), it might be better to define a single upward limit as being where 1/e (where e (approx. equal to 2.7183) is the characteristic time of the normalized Poisson process) of the materials burn, or, rounding, where approximately 1/3 of the samples fail the test (and burn). Recognizing that spacecraft atmospheres will not bound the entire oxygen-pressure parameter space, but actually lie along the normoxic atmosphere control band, we can focus the materials flammability testing along this normoxic band. A Normoxic Upward Limiting Pressure (NULP) is defined that determines the minimum safe total pressure for a material within the constant partial pressure control band. Then, increasing this pressure limit by a factor of safety, we can define the material as being safe to use at the NULP + SF (where SF is on the order of 10 kilopascal, based on existing flammability data). It is recommended that the thickest material to be tested with the current Test 1 igniter should be 3 mm thick (1/8 inches) to avoid the problem of differentiating between an ignition limit and a true flammability limit.

Differentiating Biological Colours with Few and Many Sensors: Spectral Reconstruction with RGB and Hyperspectral Cameras

PubMed Central

Garcia, Jair E.; Girard, Madeline B.; Kasumovic, Michael; Petersen, Phred; Wilksch, Philip A.; Dyer, Adrian G.

2015-01-01

Background The ability to discriminate between two similar or progressively dissimilar colours is important for many animals as it allows for accurately interpreting visual signals produced by key target stimuli or distractor information. Spectrophotometry objectively measures the spectral characteristics of these signals, but is often limited to point samples that could underestimate spectral variability within a single sample. Algorithms for RGB images and digital imaging devices with many more than three channels, hyperspectral cameras, have been recently developed to produce image spectrophotometers to recover reflectance spectra at individual pixel locations. We compare a linearised RGB and a hyperspectral camera in terms of their individual capacities to discriminate between colour targets of varying perceptual similarity for a human observer. Main Findings (1) The colour discrimination power of the RGB device is dependent on colour similarity between the samples whilst the hyperspectral device enables the reconstruction of a unique spectrum for each sampled pixel location independently from their chromatic appearance. (2) Uncertainty associated with spectral reconstruction from RGB responses results from the joint effect of metamerism and spectral variability within a single sample. Conclusion (1) RGB devices give a valuable insight into the limitations of colour discrimination with a low number of photoreceptors, as the principles involved in the interpretation of photoreceptor signals in trichromatic animals also apply to RGB camera responses. (2) The hyperspectral camera architecture provides means to explore other important aspects of colour vision like the perception of certain types of camouflage and colour constancy where multiple, narrow-band sensors increase resolution. PMID:25965264

Comparison of procedures for correction of matrix interferences in the analysis of soils by ICP-OES with CCD detection

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

Sadler, D.A.; Sun, F.; Littlejohn, D.

1995-12-31

ICP-OES is a useful technique for multi-element analysis of soils. However, as a number of elements are present in relatively high concentrations, matrix interferences can occur and examples have been widely reported. The availability of CCD detectors has increased the opportunities for rapid multi-element, multi-wave-length determination of elemental concentrations in soils and other environmental samples. As the composition of soils from industrial sites can vary considerably, especially when taken from different pit horizons, procedures are required to assess the extent of interferences and correct the effects, on a simultaneous multi-element basis. In single element analysis, plasma operating conditions can sometimesmore » be varied to minimize or even remove multiplicative interferences. In simultaneous multi-element analysis, the scope for this approach may be limited, depending on the spectrochemical characteristics of the emitting analyte species. Matrix matching, by addition of major sample components to the analyte calibrant solutions, can be used to minimize inaccuracies. However, there are also limitations to this procedure, when the sample composition varies significantly. Multiplicative interference effects can also be assessed by a {open_quotes}single standard addition{close_quotes} of each analyte to the sample solution and the information obtained may be used to correct the analyte concentrations determined directly. Each of these approaches has been evaluated to ascertain the best procedure for multi-element analysis of industrial soils by ICP-OES with CCD detection at multiple wavelengths. Standard reference materials and field samples have been analyzed to illustrate the efficacy of each procedure.« less

Singular value decomposition metrics show limitations of detector design in diffuse fluorescence tomography

PubMed Central

Leblond, Frederic; Tichauer, Kenneth M.; Pogue, Brian W.

2010-01-01

The spatial resolution and recovered contrast of images reconstructed from diffuse fluorescence tomography data are limited by the high scattering properties of light propagation in biological tissue. As a result, the image reconstruction process can be exceedingly vulnerable to inaccurate prior knowledge of tissue optical properties and stochastic noise. In light of these limitations, the optimal source-detector geometry for a fluorescence tomography system is non-trivial, requiring analytical methods to guide design. Analysis of the singular value decomposition of the matrix to be inverted for image reconstruction is one potential approach, providing key quantitative metrics, such as singular image mode spatial resolution and singular data mode frequency as a function of singular mode. In the present study, these metrics are used to analyze the effects of different sources of noise and model errors as related to image quality in the form of spatial resolution and contrast recovery. The image quality is demonstrated to be inherently noise-limited even when detection geometries were increased in complexity to allow maximal tissue sampling, suggesting that detection noise characteristics outweigh detection geometry for achieving optimal reconstructions. PMID:21258566

Model for estimating the penetration depth limit of the time-reversed ultrasonically encoded optical focusing technique

PubMed Central

Jang, Mooseok; Ruan, Haowen; Judkewitz, Benjamin; Yang, Changhuei

2014-01-01

The time-reversed ultrasonically encoded (TRUE) optical focusing technique is a method that is capable of focusing light deep within a scattering medium. This theoretical study aims to explore the depth limits of the TRUE technique for biological tissues in the context of two primary constraints – the safety limit of the incident light fluence and a limited TRUE’s recording time (assumed to be 1 ms), as dynamic scatterer movements in a living sample can break the time-reversal scattering symmetry. Our numerical simulation indicates that TRUE has the potential to render an optical focus with a peak-to-background ratio of ~2 at a depth of ~103 mm at wavelength of 800 nm in a phantom with tissue scattering characteristics. This study sheds light on the allocation of photon budget in each step of the TRUE technique, the impact of low signal on the phase measurement error, and the eventual impact of the phase measurement error on the strength of the TRUE optical focus. PMID:24663917

[Determination of aniline in water and fish by liquid chromatography-tandem mass spectrometry].

PubMed

He, Dechun; Zhao, Bo; Tang, Caiming; Xu, Zhencheng; Zhang, Sukun; Han, Jinglei

2014-09-01

A fast analytical method for the determination of aniline in water and fish meat by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. The water sample was mixed with acetonitrile by 4:1 (v/v) and the fish sample was extracted by 2.00 mL acetonitrile for each gram of sample, and then the extracts of water and fish samples were centrifuged at 5,000 r/min for 5 min. The separation was performed on a reversed-phase C18 column using mobile phases of acetonitrile-0.5% (v/v) formic acid aqueous solution (85:15, v/v). Aniline was separated within 3 min. The calibration curve was linear in the range of 0.5-500 pg/L with R2 > 0.999. The limits of detection (LODs) were 0.50 μg/L and 1.00 μg/kg and the limits of quantification (LOQs) were 1.00 μg/L and 2.00 μg/kg for aniline in water and fish meat, respectively. The average recoveries of aniline in water were 93.7% at the spiked level of 40 ng and 86.7% at the spiked level of 400 ng (n = 5). The average recoveries of aniline in fish were 96.8%, 92.6% and 81.8% at the spiked levels of 5, 50 and 500 ng respectively (n = 5). The relative standard deviations were 1.5%-9.2%. Thirteen water samples and twelve fish samples were collected from a reservoir polluted by aniline and the maximum contents found were 1,943. 6 μg/L in water and 60.8 μg/kg in fish. The method is suitable for the determination of aniline residues in water and fish with the characteristics of easy operation, high accuracy and precision.

Stressful Life Events in a Clinical Sample of Depressed Children in Hungary

PubMed Central

Mayer, László; Lopez-Duran, Nestor L.; Kovacs, Maria; George, Charles; Baji, Ildikó; Kapornai, Krisztina; Kiss, Enikő; Vetró, Ágnes

2009-01-01

Background There is limited information on the characteristics of stressful life events in depressed pediatric clinical populations and the extent to which sex, age, and their interactions may influence the relations of life events and depression. Using a very large clinical sample of children and adolescents with major depressive disorder (MDD), we therefore examined life events in various ways as well as their relations to age and sex. Method The study included a clinic-based sample of 434 children (ages 7–14) with a DSM-IV diagnosis of MDD and their mothers, and a school-based comparison sample of 724 children and their mothers. Life event information was obtained from the mothers. Results Children with MDD had twice the number of lifetime stressful events than did the comparison group, with very high levels of stressors by the age of 7–9 that stabilized across adolescence. In contrast, the comparison sample experienced a gradual increase in stressful life events as a function of age up to mid-adolescence. Parental health events, death of close relatives, and intra-familial events were significantly associated with MDD diagnosis. There were significantly stronger associations between parental health- as well as death-event clusters and MDD diagnosis among younger children than adolescents. Limitations Geographical differences between the clinical and comparison samples, as well as possible parental reporting biases may affect the generalizability of these findings. Conclusion The association between some stressful life events and MDD seems to be moderated by age, underscoring the need to examine specific events, as well as clusters of events. Better understanding of such interactions may facilitate early identification of possible risk factors for pediatric MDD. PMID:18845343

Comparative study of Nd:YAG laser-induced breakdown spectroscopy and transversely excited atmospheric CO2 laser-induced gas plasma spectroscopy on chromated copper arsenate preservative-treated wood.

PubMed

Khumaeni, Ali; Lie, Zener Sukra; Niki, Hideaki; Lee, Yong Inn; Kurihara, Kazuyoshi; Wakasugi, Motoomi; Takahashi, Touru; Kagawa, Kiichiro

2012-03-01

Taking advantage of the specific characteristics of a transversely excited atmospheric (TEA) CO(2) laser, a sophisticated technique for the analysis of chromated copper arsenate (CCA) in wood samples has been developed. In this study, a CCA-treated wood sample with a dimension of 20 mm × 20 mm and a thickness of 2 mm was attached in contact to a nickel plate (20 mm × 20 mm × 0.15 mm), which functions as a subtarget. When the TEA CO(2) laser was successively irradiated onto the wood surface, a hole with a diameter of approximately 2.5 mm was produced inside the sample and the laser beam was directly impinged onto the metal subtarget. Strong and stable gas plasma with a very large diameter of approximately 10 mm was induced once the laser beam had directly struck the metal subtarget. This gas plasma then interacted with the fine particles of the sample inside the hole and finally the particles were effectively dissociated and excited in the gas plasma region. By using this technique, high precision and sensitive analysis of CCA-treated wood sample was realized. A linear calibration curve of Cr was successfully made using the CCA-treated wood sample. The detection limits of Cr, Cu, and As were estimated to be approximately 1, 2, and 15 mg/kg, respectively. In the case of standard LIBS using the Nd:YAG laser, the analytical intensities fluctuate and the detection limit was much lower at approximately one-tenth that of TEA CO(2) laser. © 2012 Optical Society of America

Multi-parametric polymer-based potentiometric analytical microsystem for future manned space missions.

PubMed

Calvo-López, Antonio; Puyol, Mar; Casalta, Joan Manel; Alonso-Chamarro, Julián

2017-12-01

The construction and evaluation of a Cyclic Olefin Copolymer (COC)-based continuous flow potentiometric microanalyzer to simultaneously monitor potassium, chloride and nitrate ions in samples from an on-board water recycling process expected to be installed in future manned space missions is presented. The main goals accomplished in this work address the specific required characteristics for a miniaturized on-line monitoring system to control water quality in such missions. To begin with, the integration of three ion-selective electrodes (ISEs) and a reference electrode in a compact microfluidic platform that incorporates a simple automatic autocalibration process allows obtaining information about the concentration of the three ions with optimal analytical response characteristics, but moreover with low reagents consumption and therefore with few waste generation, which is critical for this specific application. By a simple signal processing (signal removal) the chloride ion interference on the nitrate electrode response can be eliminated. Furthermore, all fluidics management is performed by computer-controlled microvalves and micropumps, so no manual intervention of the crew is necessary. The analytical features provided by the microsystem after the optimization process were a linear range from 6.3 to 630 mg L -1 and a detection limit of 0.51 mg L -1 for the potassium electrode, a linear range from 10 to 1000 mg L -1 and a detection limit of 1.58 mg L -1 for the chloride electrode and a linear range from 10 to 1000 mg L -1 and a detection limit of 3.37 mg L -1 for the nitrate electrode with a reproducibility (RSD) of 4%, 2% and 3% respectively. Sample throughput was 12 h -1 with a reagent consumptions lower than 2 mL per analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Online gambling's moderators: how effective? Study protocol for a randomized controlled trial.

PubMed

Caillon, Julie; Grall-Bronnec, Marie; Hardouin, Jean-Benoit; Venisse, Jean-Luc; Challet-Bouju, Gaelle

2015-05-30

Online gambling has been legalized in France in 2010. Licenses are issued to gambling operators who demonstrate their ability to respect the legal framework (security, taxation, consumer protection, etc.). The preventive measures to protect vulnerable gamblers include an obligation to provide online gambling moderators. These moderators should allow gamblers to limit their bets, exclude themselves from the website for 7 days, and consult the balance of the gambler's account at any time. However, there are only a few published reports of empirical research investigating the effectiveness of Internet-based protective measures implemented by French law. Moreover, no empirical research has yet studied the impact of bonuses on gambling behaviors. This research is an experimental randomized controlled trial, risk prevention targeted. The research is divided into four sub-studies depending on the studied moderator: limiting bonuses, self-exclusion, self-limitation and information. The study sample consists of 485 volunteers. For each experimental condition and the control groups, the sample is composed of gamblers equally recruited from gamblers having preferences in each of the three major forms of games (lottery and scratch tickets, sports and horserace betting, and poker). For each form of gambling, the gamblers are recruited in order to obtain as many problem gamblers as non-problem gamblers. According to the randomization, the experimental session begins. The experimental session is a gambling situation on a computer in our research center. The gambler is invited to play on his favorite gambling site as usual, with his own gambler account and his own money. Data collected comprise sociodemographic characteristics, gambling habits, an interview about enjoyment and feeling out of control during the gambling session, moderator impact on gambling practice, statement of gambling parameters and questionnaires (BMIS, GRCS, CPGI, GACS). Moderator efficiency is assessed based on the two major characteristics of gambling behavior: money wagered and time spent in gambling. The results of this research will be important to prevent online problem gambling and influence policy-makers. NCT01789580. Registered 8 February 2013.

Nanoscale Analysis of Space-Weathering Features in Soils from Itokawa

NASA Technical Reports Server (NTRS)

Thompson, M. S.; Christoffersen, R.; Zega, T. J.; Keller, L. P.

2014-01-01

Space weathering alters the spectral properties of airless body surface materials by redden-ing and darkening their spectra and attenuating characteristic absorption bands, making it challenging to characterize them remotely [1,2]. It also causes a discrepency between laboratory analysis of meteorites and remotely sensed spectra from asteroids, making it difficult to associate meteorites with their parent bodies. The mechanisms driving space weathering include mi-crometeorite impacts and the interaction of surface materials with solar energetic ions, particularly the solar wind. These processes continuously alter the microchemical and structural characteristics of exposed grains on airless bodies. The change of these properties is caused predominantly by the vapor deposition of reduced Fe and FeS nanoparticles (npFe(sup 0) and npFeS respectively) onto the rims of surface grains [3]. Sample-based analysis of space weathering has tra-ditionally been limited to lunar soils and select asteroidal and lunar regolith breccias [3-5]. With the return of samples from the Hayabusa mission to asteroid Itoka-wa [6], for the first time we are able to compare space-weathering features on returned surface soils from a known asteroidal body. Analysis of these samples will contribute to a more comprehensive model for how space weathering varies across the inner solar system. Here we report detailed microchemical and microstructal analysis of surface grains from Itokawa.

A tale of two diatheses: Temperament, BIS, and BAS as risk factors for mood disorder.

PubMed

Van Meter, Anna R; Youngstrom, Eric A

2015-07-15

Learning more about how biological traits, like temperament and sensitivity in the behavioral inhibition (BIS) and behavioral activation (BAS) systems, relate to mood pathology is consistent with the Research Domain Criteria initiative׳s goal of investigating mechanisms of risk. Korean young adults (n=128) and American young adults (n=630, of whom 23 has recent treatment for bipolar disorder, and 21for depression) completed self-report questionnaires, including the TEMPS-A, the BIS/BAS scales, Beck Depression Inventory (BDI), and Hypomanic Checklist (HCL-32). Linear regression quantified relations between mood symptoms, sample characteristics, temperament, and BIS/BAS. Temperament styles explained 49% of the variance in BDI scores. BIS explained an additional 1% of the variance in BDI scores. BAS Fun and Reward (p<.01), in addition to cyclothymic and hyperthymic temperaments (p<.001) explained 21% of the variance in HCL-32 scores. Sample characteristics were not significant predictors in the full model. Differences in sample size, the cross-sectional study design, and lack of collateral report or behavioral measures of constructs are limitations. Affective temperament and BIS/BAS are complementary but distinct constructs. Affective temperament, particularly cyclothymic, may represent a stronger diathesis for mood pathology, and seems potent irrespective of culture or diagnosis. Assessing temperament may help overcome some challenges in diagnosing mood disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

The influence of secondary conditions on job acquisition and retention in adults with spinal cord injury.

PubMed

Meade, Michelle A; Forchheimer, Martin B; Krause, James S; Charlifue, Susan

2011-03-01

To examine the associations of job acquisition and job retention to secondary conditions, hospitalizations, and nursing home stays for adults with spinal cord injury (SCI). Retrospective analysis of longitudinal data from multicenter study. Community setting. Two samples of adults participating in the SCI Model Systems; the first sample consisted of persons who reported being unemployed at follow-up (n=9501); the second sample consisted of those who reported working at follow-up (n=5,150). Not applicable. Job acquisition (change from not working at 1 anniversary of injury to working at the following data collection) and job retention (maintenance of work between 2 assessment periods). Discrete time hazard modeling was used to assess how secondary conditions affect job acquisition. After controlling for the effects of demographic and injury characteristics, hospitalizations within the last 12 months were associated with decreased chance of having obtained employment. Hierarchic logistic regression analyses were used to examine job retention. Hospitalizations and the presence of PUs were associated with lower odds of job retention once demographic and injury characteristics were controlled. Secondary conditions from the previous assessment period were not significantly related to either job acquisition or job retention after the variance from demographic and injury characteristics and current secondary conditions were controlled. Hospitalization, as well as a limited number of secondary conditions, were associated with reduced odds of both job acquisition and job retention among adults with SCI. Interventions that can prevent secondary conditions and reduce the need for hospitalizations may be beneficial in improving employment for this population. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Genomic and metagenomic analysis of microbes in a soil environment affected by the 2011 Great East Japan Earthquake tsunami.

PubMed

Hiraoka, Satoshi; Machiyama, Asako; Ijichi, Minoru; Inoue, Kentaro; Oshima, Kenshiro; Hattori, Masahira; Yoshizawa, Susumu; Kogure, Kazuhiro; Iwasaki, Wataru

2016-01-14

The Great East Japan Earthquake of 2011 triggered large tsunami waves, which flooded broad areas of land along the Pacific coast of eastern Japan and changed the soil environment drastically. However, the microbial characteristics of tsunami-affected soil at the genomic level remain largely unknown. In this study, we isolated microbes from a soil sample using general low-nutrient and seawater-based media to investigate microbial characteristics in tsunami-affected soil. As expected, a greater proportion of strains isolated from the tsunami-affected soil than the unaffected soil grew in the seawater-based medium. Cultivable strains in both the general low-nutrient and seawater-based media were distributed in the genus Arthrobacter. Most importantly, whole-genome sequencing of four of the isolated Arthrobacter strains revealed independent losses of siderophore-synthesis genes from their genomes. Siderophores are low-molecular-weight, iron-chelating compounds that are secreted for iron uptake; thus, the loss of siderophore-synthesis genes indicates that these strains have adapted to environments with high-iron concentrations. Indeed, chemical analysis confirmed the investigated soil samples to be rich in iron, and culture experiments confirmed weak cultivability of some of these strains in iron-limited media. Furthermore, metagenomic analyses demonstrated over-representation of denitrification-related genes in the tsunami-affected soil sample, as well as the presence of pathogenic and marine-living genera and genes related to salt-tolerance. Collectively, the present results would provide an example of microbial characteristics of soil disturbed by the tsunami, which may give an insight into microbial adaptation to drastic environmental changes. Further analyses on microbial ecology after a tsunami are envisioned to develop a deeper understanding of the recovery processes of terrestrial microbial ecosystems.

Neurocognition and psychosocial functioning in adolescents with bipolar disorder.

PubMed

Best, Michael W; Bowie, Christopher R; Naiberg, Melanie R; Newton, Dwight F; Goldstein, Benjamin I

2017-01-01

Adults with bipolar disorder demonstrate significantly poorer psychosocial functioning and neurocognition compared to controls. In adult bipolar disorder neurocognition predicts a substantial portion of variance in functioning. Adolescents with bipolar disorder have reducedpsychosocial functioning, but less is known about neurocognitive impairments, and no studies have examined the relationship between neurocognition and functioning in an adolescent sample. 38 adolescents with bipolar disorder and 49 healthy controls under 20 years of age completed assessments of psychosocial functioning, neurocognitive ability, and psychiatric symptoms. Adolescents with bipolar disorder had significantly poorer psychosocial functioning in domains of daily activities, social functioning, and satisfaction with functioning, ps<.006, compared to healthy controls. They also had poorer general neurocognitive functioning than controls, p=.004, with the greatest impairment on a test of sustained attention. Neurocognition was not a significant predictor of psychosocial functioning in this sample, but depressive symptoms significantly predicted functioning in all domains, p<.033. Limited sample size did not allow for complex statistical analyses. Differences in demographic characteristics of the clinical and control groups may limit generalization of these results. This adolescent sample with bipolar disorder experiences significantly poorer neurocognitive and psychosocial functioning compared to controls; however, psychosocial functioning appears to be more strongly related to mood symptoms than to neurocognition. Future work is needed to delineate the time course of neurocognitive functioning and its relation to psychosocial functioning across the course of illness. Adolescence may provide an ideal time for cognitive enhancement and intensive psychosocial intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlations between soil characteristics and radioactivity content of Vojvodina soil.

PubMed

Forkapic, S; Vasin, J; Bikit, I; Mrdja, D; Bikit, K; Milić, S

2017-01-01

During the years 2001 and 2010, the content of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs in agricultural soil and soil geochemical characteristics were measured on 50 locations in Northern Province of Serbia - Vojvodina. The locations for sampling were selected so that they proportionately represent all geomorphologic units in the region. The content of clay and humus varied within wide limits depending on soil type and influence the activity concentrations of radionuclides. In this paper we analyzed correlations between radionuclides content and geochemical characteristics of the soil. Possible influence of fertilizers on 238 U content in soil was discussed. The main conclusion is that measured maximal activity concentrations for 238 U (87 Bq/kg), 226 Ra (44.7 Bq/kg), 232 Th (55.5 Bq/kg) and 137 Cs (29 Bq/kg) at 30 cm depth could not endanger the safety of food production. The process of genesis of soil and cultivation mode plays a dominant role on the characteristics of the soil. The most significant correlation was found between the activity concentrations of 40 K and clay content in agricultural soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence and characteristics of vibrator use among women who have sex with women.

PubMed

Schick, Vanessa; Herbenick, Debby; Rosenberger, Joshua G; Reece, Michael

2011-12-01

Research suggests that vibrator use may be more prevalent among lesbian/bisexual-identified women. However, previous research has been limited by small samples of lesbian- and bisexual-identified women and has not focused specifically on the characteristics of vibrator use between women. The present study was designed in order to develop a comprehensive understanding of women's use of vibrators with their female sexual partners and to understand the extent to which vibrator use is related to their sexual experiences. Data were collected via a cross-sectional web-based survey from 2,192 women living in the United States and the United Kingdom. All participants reported engaging in sexual behavior with only women in the previous year. Sociodemographic characteristics, vibrator use history, vibrator use perceptions, and the Female Sexual Function Index (FSFI). Over three-quarters of women in the sample reported a history of vibrator use during solo masturbation/with a female partner and over a quarter of the sample reported use in the previous month. Participants who were older, white, and in a long-term relationship were the most likely to use a vibrator with a female partner in the previous year. Vibrator use lifetime history was unrelated to all FSFI subscales with the exception of pain for lesbian and queer-identified women. In contrast to lifetime use, participants who used a vibrator with a female sexual partner in the previous month scored higher on several of the FSFI domains than women who reported no vibrator use or vibrator use only during solo masturbation in the past month. Vibrator use was common among this sample of women who have sex with women. Women who reported recent vibrator use with other women had higher mean sexual functioning scores than women who reported no vibrator use or vibrator use only during masturbation. Implications for health-care providers are discussed. © 2011 International Society for Sexual Medicine.

Relation between selected well-construction characteristics and occurrence of bacteria in private household-supply wells, south-central and southeastern Pennsylvania

USGS Publications Warehouse

Zimmerman, Tammy M.; Zimmerman, Michele L.; Lindsey, Bruce D.

2001-01-01

Total coliform and Escherichia coli (E. coli) bacteria were analyzed in ground water sampled from 78 private household-supply wells as part of a study by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Protection to evaluate the relation between well construction characteristics and the occurrence of bacteria in ground water. Sampling was done in eight counties in south-central and southeastern Pennsylvania from September 2000 to March 2001. All samples were collected from wells in close proximity to agricultural land-use areas.Total coliform bacteria were found in water from 62 percent (48 of 78) of the wells, and bacteria were just as likely to be found in sanitary wells (grouted/loose-fitting well cap or grouted/sanitary sealed well cap) as in nonsanitary wells (nongrouted/ loose-fitting well cap). The areas underlain by carbonate bedrock had the highest percentages of total coliform detected (about 75 percent). Nearly half of the samples collected in the areas underlain by noncarbonate bedrock also were found to have total coliform present. E. coli bacteria were found in water from 10 percent of the wells. Seventeen percent of the samples that were positive for total coliform also were positive for E. coli. The presence of E. coli bacteria was more likely in water from nonsanitary wells. Additionally, the presence of E. coli bacteria was more likely in ground water from wells underlain by carbonate bedrock. A further breakdown of the data into four groups on the basis of sanitary construction and bedrock type indicated the presence of E. coli was more likely in water from nonsanitary wells in areas underlain by carbonate bedrock.Statistical analysis of other well-construction characteristics that might relate to occurrence of bacteria showed that the presence of total coliform bacteria was related to the depth to water-bearing zone in both sanitary and nonsanitary wells in areas underlain by carbonate bedrock. Relations also are present between the presence of total coliform bacteria and casing length in nonsanitary wells in areas underlain by noncarbonate bedrock. Bacteria were found in wells both with and without insects observed on the underside of the well cap. Because of the small number of wells sampled that had sanitary sealed caps, it is uncertain whether installation of sanitary sealed well caps would reduce the incidence of bacteria in ground water from wells or if the presence of bacteria is because of a combination of well-construction characteristics or aquifer-wide contamination of limited or broad areal extent.

Performance of the New Aptima HCV Quant Dx Assay in Comparison to the Cobas TaqMan HCV2 Test for Use with the High Pure System in Detection and Quantification of Hepatitis C Virus RNA in Plasma or Serum.

PubMed

Schalasta, Gunnar; Speicher, Andrea; Börner, Anna; Enders, Martin

2016-04-01

Quantitating the level of hepatitis C virus (HCV) RNA is the standard of care for monitoring HCV-infected patients during treatment. The performances of commercially available assays differ for precision, limit of detection, and limit of quantitation (LOQ). Here, we compare the performance of the Hologic Aptima HCV Quant Dx assay (Aptima) to that of the Roche Cobas TaqMan HCV test, version 2.0, using the High Pure system (HPS/CTM), considered a reference assay since it has been used in trials defining clinical decision points in patient care. The assays' performance characteristics were assessed using HCV RNA reference panels and plasma/serum from chronically HCV-infected patients. The agreement between the assays for the 3 reference panels was good, with a difference in quantitation values of <0.5 log. High concordance was demonstrated between the assays for 245 clinical samples (kappa = 0.80; 95% confidence interval [CI], 0.720 to 0.881); however, Aptima detected and/or quantitated 20 samples that HPS/CTM did not detect, while Aptima did not detect 1 sample that was quantitated by HPS/CTM. For the 165 samples quantitated by both assays, the values were highly correlated (R= 0.98;P< 0.0001). The linearity of quantitation from concentrations of 1.4 to 6 log was excellent for both assays for all HCV genotypes (GT) tested (GT 1a, 1b, 2b, and 3a) (R(2)> 0.99). The assays had similar levels of total and intra-assay variability across all genotypes at concentrations from 1,000 to 25 IU/ml. Aptima had a greater analytical sensitivity, quantitating more than 50% of replicates at 25-IU/ml target. Aptima showed performance characteristics comparable to those of HPS/CTM and increased sensitivity, making it suitable for use as a clinical diagnostic tool on the fully automated Panther platform. Copyright © 2016 Schalasta et al.

[Application of ICP-MS and ICP-AES for Studying on Source Apportionment of PM2.5 during Haze Weather in Urban Beijing].

PubMed

Chen, Xi; Du, Peng; Guan, Qing; Feng, Xu; Xu, Dong-qun; Lin, Shao-bin

2015-06-01

To investigate the characteristics of chemical constitute and pollution sources of aerosol fine particulate matter during haze-fog day in Beijing in winter 2013. The samples of PM2.5 were collected in Beijing from January to February, 2013. The technique of ICP-MS and ICP-AES coupled with procedure of bathing-ultrasonic extraction was applied to determine the concentration of 40 elements in the aerosol samples to analyze the characteristics of elements distribution statistically. The absolute principal factor method was used to apportion the pollution sources of PM2.5 during the haze weather in Beijing city in winter 2013. The results showed that during the period of sampling, the volume concentration of Li, Mn, Pb, S etc. obeyed normal distribution approximately, and according to National Ambient Air Quality Standard issued by Ministry of Environmental Protection of the People's Republic of China, the geometric mean concentration of As was twice the annual limit of standard reference, while Pb of some aerosol samples beyond the annual limit of standard reference respectively. The mass fraction of Fe, Zn, Pb, Ti accounted for over 0.1%, while that of Mn, Cu, As, Se etc. 0.01%. These elements were primary inorganic pollutants, and especially the hazards and sources of As and Pb should be concerned. There were 6 main pollution sources were chosen by the factor analysis method, including industrial dust and human beings activities, biomass combustion and building dust, soil and sand dusts, fossil fuel, electronic waste and metal smelting, with the variance contribution rate of 40.3%, 27.0%, 9.1%, 4.9%, 4.8% and 4.6% respectively. ICP-MS and ICP-AES can be applied to analyzing multi-elements in PM2.5 accurately and quickly to facilitate source apportionment, and it indicated that the relevant pollution sources should be considered and the effect of regional transferring of haze pollution sources should be taken into account, and specific measures should be taken for control.

[The father image in male substance users].

PubMed

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

2002-01-01

Due to the fact that various research studies have shown that drug users usually have a father with negative characteristics, it is convenient to investigate this phenomenon and take it into consideration in addict treatment efforts. This is a qualitative study that explores the fatherly perception among male substance users. The sample included 25 users who asked for treatment at Youth Integration Center and 25 non-users. Both groups were subjected to projective tests. The father image among substance users emphasizes negative characteristics; in contrast, non-users present a basically positive father perception, considering him as the most valuable family member. These data show that substance users relate less with the fatherly figure than non-users. They perceive their father as a devaluated member that occupies a secondary place in the family and sometimes does not even have an affective role. The findings of this investigation can be applied in individual psychotherapy, facilitating the revaluation and reflection of the fatherly figure among substance users. It would be convenient to create the necessary conditions to restitute the father role in family therapy and counseling groups for relatives. The findings must consider the size of the sample and limitations of qualitative research methology.

Tanning addiction and psychopathology: Further evaluation of anxiety disorders and substance abuse

PubMed Central

Ashrafioun, Lisham; Bonar, Erin E.

2014-01-01

Background Little research has investigated the correlates of problematic tanning and tanning dependence. Objective To identify characteristics associated with problematic tanning and tanning dependence, and to evaluate simultaneously the associations of variables as correlates of problematic tanning and tanning dependence. Method To assess tanning-related characteristics, psychopathology, and demographics, we administered questionnaires to 533 tanning university students; 31% met criteria for tanning dependence, 12% for problematic tanning. Results Both problematic tanning and tanning dependence were significantly associated with being female (p < .001; p < .001, respectively) and with higher scores on screening measures of obsessive-compulsive (p < .001, p = .005, respectively) and body dysmorphic disorders (p = .019, p < .001, respectively). Frequency of tanning in the past month was the strongest correlate of problematic tanning (p < .001) and tanning dependence (p < .001) when included in a model that controlled for shared variance among demographics and psychopathology. Limitations The sample was recruited from one university and contained only self-report measures. Conclusion Results suggest that those who engage in excessive tanning may also have significant psychiatric distress. Additional research is needed to characterize compulsive, problematic tanning as well as its rates, correlates, and risk factors among diverse samples. PMID:24373775

Work-related psychosocial stress and risk of preterm, low birthweight delivery.

PubMed Central

Homer, C J; James, S A; Siegel, E

1990-01-01

We investigated whether work-related psychologic stress--defined as work characterized by both high psychologic demands and limited control over the response to these demands--increases a woman's risk of delivering a preterm, low birthweight infant. We studied 786 employed pregnant women included in the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), a nationally representative sample of 12,686 young adults. Data concerning work status, job title, and other factors affecting pregnancy outcome were obtained from the NLSY. Assessment of job experience was based on job title, using an established catalogue of occupation characteristics. After accounting for the physical exertion entailed in a job, occupational psychologic stress as measured by job title was not associated with preterm, low birthweight delivery for the sample as a whole (Relative risk = 1.16, 95% confidence interval .45, 2.95). For those women who did not want to remain in the work force, work-related stress increased their risk of experiencing this outcome (RR = 8.1, 95% CI 1.5, 50.2). Personal motivation toward work, as well as the physical effort of work, should be considered in evaluating the impact of a job's psychologic characteristics on pregnancy outcome. PMID:2297061

Application of Structured Light System Technique for Authentication of Wooden Panel Paintings.

PubMed

Buchón-Moragues, Fernando; Bravo, José María; Ferri, Marcelino; Redondo, Javier; Sánchez-Pérez, Juan Vicente

2016-06-14

This paper presents a new application of photogrammetric techniques for protecting cultural heritage. The accuracy of the method and the fact that it can be used to carry out different tests without contact between the sample and the instruments can make this technique very useful for authenticating and cataloging artworks. The application focuses on the field of pictorial artworks, and wooden panel paintings in particular. In these works, the orography formed by the brushstrokes can be easily digitalized using a photogrammetric technique, called Structured Light System, with submillimeter accuracy. Thus, some of the physical characteristics of the brushstrokes, like minimum and maximum heights or slopes become a fingerprint of the painting. We explain in detail the general principles of the Structured Light System Technique and the specific characteristics of the commercial set-up used in this work. Some experiments are carried out on a sample painted by us to check the accuracy limits of the technique and to propose some tests that can help to stablish a methodology for authentication purposes. Finally, some preliminary results obtained on a real pictorial artwork are presented, providing geometrical information of its metric features as an example of the possibilities of this application.

Microfluidic Lab-on-a-Chip Platforms: Requirements, Characteristics and Applications

NASA Astrophysics Data System (ADS)

Mark, D.; Haeberle, S.; Roth, G.; Von Stetten, F.; Zengerle, R.

This review summarizes recent developments in microfluidic platform approaches. In contrast to isolated application-specific solutions, a microfluidic platform provides a set of fluidic unit operations, which are designed for easy combination within a well-defined fabrication technology. This allows the implementation of different application-specific (bio-) chemical processes, automated by microfluidic process integration [1]. A brief introduction into technical advances, major market segments and promising applications is followed by a detailed characterization of different microfluidic platforms, comprising a short definition, the functional principle, microfluidic unit operations, application examples as well as strengths and limitations. The microfluidic platforms in focus are lateral flow tests, linear actuated devices, pressure driven laminar flow, microfluidic large scale integration, segmented flow microfluidics, centrifugal microfluidics, electro-kinetics, electrowetting, surface acoustic waves, and systems for massively parallel analysis. The review concludes with the attempt to provide a selection scheme for microfluidic platforms which is based on their characteristics according to key requirements of different applications and market segments. Applied selection criteria comprise portability, costs of instrument and disposable, sample throughput, number of parameters per sample, reagent consumption, precision, diversity of microfluidic unit operations and the flexibility in programming different liquid handling protocols.

Application of Structured Light System Technique for Authentication of Wooden Panel Paintings

PubMed Central

Buchón-Moragues, Fernando; Bravo, José María; Ferri, Marcelino; Redondo, Javier; Sánchez-Pérez, Juan Vicente

2016-01-01

This paper presents a new application of photogrammetric techniques for protecting cultural heritage. The accuracy of the method and the fact that it can be used to carry out different tests without contact between the sample and the instruments can make this technique very useful for authenticating and cataloging artworks. The application focuses on the field of pictorial artworks, and wooden panel paintings in particular. In these works, the orography formed by the brushstrokes can be easily digitalized using a photogrammetric technique, called Structured Light System, with submillimeter accuracy. Thus, some of the physical characteristics of the brushstrokes, like minimum and maximum heights or slopes become a fingerprint of the painting. We explain in detail the general principles of the Structured Light System Technique and the specific characteristics of the commercial set-up used in this work. Some experiments are carried out on a sample painted by us to check the accuracy limits of the technique and to propose some tests that can help to stablish a methodology for authentication purposes. Finally, some preliminary results obtained on a real pictorial artwork are presented, providing geometrical information of its metric features as an example of the possibilities of this application. PMID:27314353

Work-related psychosocial stress and risk of preterm, low birthweight delivery.

PubMed

Homer, C J; James, S A; Siegel, E

1990-02-01

We investigated whether work-related psychologic stress--defined as work characterized by both high psychologic demands and limited control over the response to these demands--increases a woman's risk of delivering a preterm, low birthweight infant. We studied 786 employed pregnant women included in the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), a nationally representative sample of 12,686 young adults. Data concerning work status, job title, and other factors affecting pregnancy outcome were obtained from the NLSY. Assessment of job experience was based on job title, using an established catalogue of occupation characteristics. After accounting for the physical exertion entailed in a job, occupational psychologic stress as measured by job title was not associated with preterm, low birthweight delivery for the sample as a whole (Relative risk = 1.16, 95% confidence interval .45, 2.95). For those women who did not want to remain in the work force, work-related stress increased their risk of experiencing this outcome (RR = 8.1, 95% CI 1.5, 50.2). Personal motivation toward work, as well as the physical effort of work, should be considered in evaluating the impact of a job's psychologic characteristics on pregnancy outcome.

Daily social interactions, close relationships, and systemic inflammation in two samples: Healthy middle-aged and older adults.

PubMed

Bajaj, Amoha; John-Henderson, Neha A; Cundiff, Jenny M; Marsland, Anna L; Manuck, Stephen B; Kamarck, Thomas W

2016-11-01

Systemic inflammation is thought to be a biological mediator between social relationship quality and premature mortality. Empirical work has yielded mixed support for an association of social relationship variables with systemic inflammation, perhaps due to methodological limitations. To date, research in this literature has focused on global perceptions of social relationships, with limited attention to the covariance of characteristics of daily social interactions with inflammation. Here, we examine whether daily interactions, as assessed by ecological momentary assessment (EMA), associate with peripheral markers of inflammation among midlife and older adults. Global social support and integration were measured using the Interpersonal Support Evaluation List (ISEL) and the Social Network Index (SNI), respectively, in older adults from the Pittsburgh Healthy Heart Project (PHHP), and in middle-aged adults from the Adult Health and Behavior Project-II (AHAB-II). Using time-sampled EMA, we assessed the proportion of the day spent in positive and negative social interactions. Systemic markers of inflammation were interleukin (IL)-6 and C-reactive protein (CRP). Global measures of support and integration did not associate with inflammation in either sample. In older adults, relative frequency of total positive interactions, those with close others (i.e. spouse, friends, family), and those with coworkers predicted lower concentrations of IL-6 in fully adjusted models, accounting for age, sex, race, education, BMI, smoking and alcohol. In middle-aged adults, relative frequency of positive interactions with close others was also inversely associated with IL-6 level and relative frequency of negative marital interactions was unexpectedly inversely associated with CRP level. Characteristics of daily social interactions among midlife and older adults associate with markers of systemic inflammation that are known to predict risk for cardiovascular disease. Ambulatory measures may better capture health-relevant social processes in daily life than retrospective, global self-report measures. Published by Elsevier Inc.

Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

NASA Astrophysics Data System (ADS)

Kowalewska, Zofia

2011-07-01

For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the ∆ν = 0 vibrational sequence within the electronic transition X 1∑ + → A 1П, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd xS y molecules. At the 258.056 nm line, with the wavelength range covering central pixel ± 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg -1 in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg -1 in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with sulphur content determined by X-ray fluorescence spectrometry).

The relationship between physical and psychological complaints and quality of life in severely injured patients.

PubMed

van Delft-Schreurs, C C H M; van Son, M A C; de Jongh, M A C; Lansink, K W W; de Vries, J; Verhofstad, M H J

2017-09-01

The purpose of this study was two-fold. The first goal was to investigate which variables were associated with the remaining physical limitations of severely injured patients after the initial rehabilitation phase. Second, we investigated whether physical limitations were attributable to the association between psychological complaints and quality of life in this patient group. Patients who were 18 years or older and who had an injury severity score (ISS)>15 completed a set of questionnaires at one time-point after their rehabilitation phase (15-53 months after their trauma). The Short Musculoskeletal Function Assessment (SMFA) questionnaire was used to determine physical limitations. The Hospital Anxiety and Depression Scale, the Dutch Impact of Event Scale and the Cognitive Failure Questionnaire were used to determine psychological complaints, and the World Health Organization Quality of Life assessment instrument-BREF was used to measure general Quality of Life (QOL). Differences in physical limitations were investigated for several trauma- and patient-related variables using non-parametric independent-sample Mann-Whitney U tests. Multiple linear regression was performed to investigate whether the decreased QOL of severely injured patients with psychological complaints could be explained by their physical limitations. Older patients, patients with physical complaints before the injury, patients with higher ISS scores, and patients who had an injury of the spine or of the lower extremities reported significantly more physical problems. Additionally, patients with a low education level, patients who were living alone, and those who were unemployed reported significantly more long-term physical problems. Severely injured patients without psychological complaints reported significantly less physical limitations than those with psychological complaints. The SMFA factor of Lower extremity dysfunction was a confounder of the association between psychological complaints and QOL in all QOL domains. Long-term physical limitations were mainly reported by patients with psychological complaints. The decreased QOL of severely injured patients with psychological complaints can partially be explained by physical limitations, particularly those involving lower extremity function. Experienced physical limitations were significantly different for some trauma and patient characteristics. These characteristics may be used to select patients for whom a rehabilitation programme would be useful. Copyright © 2017. Published by Elsevier Ltd.

Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling

PubMed Central

Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2017-01-01

Background In using regularly collected or existing surveillance data to characterize engagement in human immunodeficiency virus (HIV) services among marginalized populations, differences in sampling methods may produce different pictures of the target population and may therefore result in different priorities for response. Objective The objective of this study was to use existing data to evaluate the sample distribution of eight studies of female sex workers (FSW) and men who have sex with men (MSM), who were recruited using different sampling approaches in two locations within Sub-Saharan Africa: Manzini, Swaziland and Yaoundé, Cameroon. Methods MSM and FSW participants were recruited using either respondent-driven sampling (RDS) or venue-based snowball sampling. Recruitment took place between 2011 and 2016. Participants at each study site were administered a face-to-face survey to assess sociodemographics, along with the prevalence of self-reported HIV status, frequency of HIV testing, stigma, and other HIV-related characteristics. Crude and RDS-adjusted prevalence estimates were calculated. Crude prevalence estimates from the venue-based snowball samples were compared with the overlap of the RDS-adjusted prevalence estimates, between both FSW and MSM in Cameroon and Swaziland. Results RDS samples tended to be younger (MSM aged 18-21 years in Swaziland: 47.6% [139/310] in RDS vs 24.3% [42/173] in Snowball, in Cameroon: 47.9% [99/306] in RDS vs 20.1% [52/259] in Snowball; FSW aged 18-21 years in Swaziland 42.5% [82/325] in RDS vs 8.0% [20/249] in Snowball; in Cameroon 15.6% [75/576] in RDS vs 8.1% [25/306] in Snowball). They were less educated (MSM: primary school completed or less in Swaziland 42.6% [109/310] in RDS vs 4.0% [7/173] in Snowball, in Cameroon 46.2% [138/306] in RDS vs 14.3% [37/259] in Snowball; FSW: primary school completed or less in Swaziland 86.6% [281/325] in RDS vs 23.9% [59/247] in Snowball, in Cameroon 87.4% [520/576] in RDS vs 77.5% [238/307] in Snowball) than the snowball samples. In addition, RDS samples indicated lower exposure to HIV prevention information, less knowledge about HIV prevention, limited access to HIV prevention tools such as condoms, and less-reported frequency of sexually transmitted infections (STI) and HIV testing as compared with the venue-based samples. Findings pertaining to the level of disclosure of sexual practices and sexual practice–related stigma were mixed. Conclusions Samples generated by RDS and venue-based snowball sampling produced significantly different prevalence estimates of several important characteristics. These findings are tempered by limitations to the application of both approaches in practice. Ultimately, these findings provide further context for understanding existing surveillance data and how differences in methods of sampling can influence both the type of individuals captured and whether or not these individuals are representative of the larger target population. These data highlight the need to consider how program coverage estimates of marginalized populations are determined when characterizing the level of unmet need. PMID:29054832

Characteristics of Occupational Exposure to Benzene during Turnaround in the Petrochemical Industries.

PubMed

Chung, Eun-Kyo; Shin, Jung-Ah; Lee, Byung-Kyu; Kwon, Jiwoon; Lee, Naroo; Chung, Kwang-Jae; Lee, Jong-Han; Lee, In-Seop; Kang, Seong-Kyu; Jang, Jae-Kil

2010-09-01

The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.

Associations between Perceptions of Drinking Water Service Delivery and Measured Drinking Water Quality in Rural Alabama

PubMed Central

Wedgworth, Jessica C.; Brown, Joe; Johnson, Pauline; Olson, Julie B.; Elliott, Mark; Forehand, Rick; Stauber, Christine E.

2014-01-01

Although small, rural water supplies may present elevated microbial risks to consumers in some settings, characterizing exposures through representative point-of-consumption sampling is logistically challenging. In order to evaluate the usefulness of consumer self-reported data in predicting measured water quality and risk factors for contamination, we compared matched consumer interview data with point-of-survey, household water quality and pressure data for 910 households served by 14 small water systems in rural Alabama. Participating households completed one survey that included detailed feedback on two key areas of water service conditions: delivery conditions (intermittent service and low water pressure) and general aesthetic characteristics (taste, odor and color), providing five condition values. Microbial water samples were taken at the point-of-use (from kitchen faucets) and as-delivered from the distribution network (from outside flame-sterilized taps, if available), where pressure was also measured. Water samples were analyzed for free and total chlorine, pH, turbidity, and presence of total coliforms and Escherichia coli. Of the 910 households surveyed, 35% of participants reported experiencing low water pressure, 15% reported intermittent service, and almost 20% reported aesthetic problems (taste, odor or color). Consumer-reported low pressure was associated with lower gauge-measured pressure at taps. While total coliforms (TC) were detected in 17% of outside tap samples and 12% of samples from kitchen faucets, no reported water service conditions or aesthetic characteristics were associated with presence of TC. We conclude that consumer-reported data were of limited utility in predicting potential microbial risks associated with small water supplies in this setting, although consumer feedback on low pressure—a risk factor for contamination—may be relatively reliable and therefore useful in future monitoring efforts. PMID:25046635

Associations between perceptions of drinking water service delivery and measured drinking water quality in rural Alabama.

PubMed

Wedgworth, Jessica C; Brown, Joe; Johnson, Pauline; Olson, Julie B; Elliott, Mark; Forehand, Rick; Stauber, Christine E

2014-07-18

Although small, rural water supplies may present elevated microbial risks to consumers in some settings, characterizing exposures through representative point-of-consumption sampling is logistically challenging. In order to evaluate the usefulness of consumer self-reported data in predicting measured water quality and risk factors for contamination, we compared matched consumer interview data with point-of-survey, household water quality and pressure data for 910 households served by 14 small water systems in rural Alabama. Participating households completed one survey that included detailed feedback on two key areas of water service conditions: delivery conditions (intermittent service and low water pressure) and general aesthetic characteristics (taste, odor and color), providing five condition values. Microbial water samples were taken at the point-of-use (from kitchen faucets) and as-delivered from the distribution network (from outside flame-sterilized taps, if available), where pressure was also measured. Water samples were analyzed for free and total chlorine, pH, turbidity, and presence of total coliforms and Escherichia coli. Of the 910 households surveyed, 35% of participants reported experiencing low water pressure, 15% reported intermittent service, and almost 20% reported aesthetic problems (taste, odor or color). Consumer-reported low pressure was associated with lower gauge-measured pressure at taps. While total coliforms (TC) were detected in 17% of outside tap samples and 12% of samples from kitchen faucets, no reported water service conditions or aesthetic characteristics were associated with presence of TC. We conclude that consumer-reported data were of limited utility in predicting potential microbial risks associated with small water supplies in this setting, although consumer feedback on low pressure-a risk factor for contamination-may be relatively reliable and therefore useful in future monitoring efforts.

Simulations with current constraints of ELM-induced tungsten melt motion in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Thorén, E.; Bazylev, B.; Ratynskaia, S.; Tolias, P.; Krieger, K.; Pitts, R. A.; Pestchanyi, S.; Komm, M.; Sieglin, B.; the EUROfusion MST1 Team; the ASDEX Upgrade Team

2017-12-01

Melt motion simulations of recent ASDEX Upgrade experiments on transient-induced melting of a tungsten leading edge during ELMing H-mode are performed with the incompressible fluid dynamics code MEMOS 3D. The total current flowing through the sample was measured in these experiments providing an important constraint for the simulations since thermionic emission is considered to be responsible for the replacement current driving melt motion. To allow for a reliable comparison, the description of the space-charge limited regime of thermionic emission has been updated in the code. The effect of non-periodic aspects of the spatio-temporal heat flux in the temperature distribution and melt characteristics as well as the importance of current limitation are investigated. The results are compared with measurements of the total current and melt profile.

In-Space Manufacturing Baseline Property Development

NASA Technical Reports Server (NTRS)

Stockman, Tom; Schneider, Judith; Prater, Tracie; Bean, Quincy; Werkheiser, Nicki

2016-01-01

The In-Space Manufacturing (ISM) project at NASA Marshall Space Flight Center currently operates a 3D FDM (fused deposition modeling) printer onboard the International Space Station. In order to enable utilization of this capability by designer, the project needs to establish characteristic material properties for materials produced using the process. This is difficult for additive manufacturing since standards and specifications do not yet exist for these technologies. Due to availability of crew time, there are limitations to the sample size which in turn limits the application of the traditional design allowables approaches to develop a materials property database for designers. In this study, various approaches to development of material databases were evaluated for use by designers of space systems who wish to leverage in-space manufacturing capabilities. This study focuses on alternative statistical techniques for baseline property development to support in-space manufacturing.

RICKETS IN RURAL KENYAN PRESCHOOL CHILDREN: CASE REPORT.

PubMed

Bwibo, N O; Nyawade, S; Neumann, C G

2013-03-01

Clinical rickets has not been reported previously in Embu district, Kenya. Baseline clinical assessments performed for a nutrition intervention study in preschool children (n=324) identified 28 cases of rickets (8.6% of study sample). Clinical characteristics included: delays of sitting, walking, and teething; bone and chest deformities; widened wrists and ankles; and bowed lower extremities. Risk factors identified were short duration of breastfeeding with feeding of cereal-based supplements with little or no milk, low calcium intake, limited sunlight exposure. Vitamin D and calcium deficiencies likely contributed to these cases. Treatment with Vitamin D3 and milk resulted in clinical improvement.

Mapping the nanoscale energetic landscape in conductive polymer films with spatially super-resolved exciton dynamics

NASA Astrophysics Data System (ADS)

Ginsberg, Naomi

2015-03-01

The migration of Frenkel excitons, tightly-bound electron-hole pairs, in polymeric organic semiconducting films is critical to the efficiency of bulk heterojunction solar cells. While these materials exhibit a high degree of structural heterogeneity on the nanoscale, traditional measurements of exciton diffusion lengths are performed on bulk samples. Since both the characteristic length scales of structural heterogeneity and the reported bulk diffusion lengths are smaller than the optical diffraction limit, we adapt far-field super-resolution fluorescence imaging to uncover the correlations between the structural and energetic landscapes that the excitons explore.

On estimating the effects of clock instability with flicker noise characteristics

NASA Technical Reports Server (NTRS)

Wu, S. C.

1981-01-01

A scheme for flicker noise generation is given. The second approach is that of successive segmentation: A clock fluctuation is represented by 2N piecewise linear segments and then converted into a summation of N+1 triangular pulse train functions. The statistics of the clock instability are then formulated in terms of two sample variances at N+1 specified averaging times. The summation converges very rapidly that a value of N 6 is seldom necessary. An application to radio interferometric geodesy shows excellent agreement between the two approaches. Limitations to and the relative merits of the two approaches are discussed.

Psychometric properties of the Brand Personality Scale: evidence from a business school.

PubMed

Caruana, Albert; Pitt, Leyland F; Berthon, Pierre; Berthon, J-P

2007-06-01

The Brand Personality Scale has received considerable attention and has been frequently used and cited in the branding literature. This paper describes an investigation of the psychometric characteristics of the Brand Personality Scale in a business school context where umbrella branding is used. A sample (N=262) of students attending the MBA program of a major business school in eastern USA completed the scale. Results indicate problems with the scale's dimensionality, poor reliability, convergent and nomological validity of the Ruggedness dimension, and lack of support for discriminant validity. Managerial and research implications and limitations are noted.

Distinctive and Complementary MS2 Fragmentation Characteristics for Identification of Sulfated Sialylated N-Glycopeptides by nanoLC-MS/MS Workflow

NASA Astrophysics Data System (ADS)

Kuo, Chu-Wei; Guu, Shih-Yun; Khoo, Kay-Hooi

2018-04-01

High sensitivity identification of sulfated glycans carried on specific sites of glycoproteins is an important requisite for investigation of molecular recognition events involved in diverse biological processes. However, aiming for resolving site-specific glycosylation of sulfated glycopeptides by direct LC-MS2 sequencing is technically most challenging. Other than the usual limiting factors such as lower abundance and ionization efficiency compared to analysis of non-glycosylated peptides, confident identification of sulfated glycopeptides among the more abundant non-sulfated glycopeptides requires additional considerations in the selective enrichment and detection strategies. Metal oxide has been applied to enrich phosphopeptides and sialylated glycopeptides, but its use to capture sulfated glycopeptides has not been investigated. Likewise, various complementary MS2 fragmentation modes have yet to be tested against sialylated and non-sialylated sulfoglycopeptides due to limited appropriate sample availability. In this study, we have investigated the feasibility of sequencing tryptic sulfated N-glycopeptide and its MS2 fragmentation characteristics by first optimizing the enrichment methods to allow efficient LC-MS detection and MS2 analysis by a combination of CID, HCD, ETD, and EThcD on hybrid and tribrid Orbitrap instruments. Characteristic sulfated glyco-oxonium ions and direct loss of sulfite from precursors were detected as evidences of sulfate modification. It is anticipated that the technical advances demonstrated in this study would allow a feasible extension of our sulfoglycomic analysis to sulfoglycoproteomics. [Figure not available: see fulltext.

Determination of Slake Durability Index (Sdi) Values on Different Shape of Laminated Marl Samples

NASA Astrophysics Data System (ADS)

Ankara, Hüseyin; Çiçek, Fatma; Talha Deniz, İsmail; Uçak, Emre; Yerel Kandemir, Süheyla

2016-10-01

The slake durability index (SDI) test is widely used to determine the disintegration characteristic of the weak and clay-bearing rocks in geo-engineering problems. However, due to the different shapes of sample pieces, such as, irregular shapes displayed mechanical breakages in the slaking process, the SDI test has some limitations that affect the index values. In addition, shape and surface roughness of laminated marl samples have a severe influence on the SDI. In this study, a new sample preparation method called Pasha Method was used to prepare spherical specimens from the laminated marl collected from Seyitomer collar (SLI). Moreover the SDI tests were performed on equal size and weight specimens: three sets with different shapes were used. The three different sets were prepared as the test samples which had sphere shape, parallel to the layers in irregular shape, and vertical to the layers in irregular shape. Index values were determined for the three different sets subjected to the SDI test for 4 cycles. The index values at the end of fourth cycle were found to be 98.43, 98.39 and 97.20 %, respectively. As seen, the index values of the sphere sample set were found to be higher than irregular sample sets.

Synthesis and Analysis of MnTiO3 Thin Films on ITO Coated Glass Substrates

NASA Astrophysics Data System (ADS)

Martin, Emerick; Sahiner, Mehmet-Alper

Perovskites like Manganese Titanium Oxide have interesting chemical properties that may be advantageous to the development of p-n junction photovoltaic cells. Due to the limited understanding behind the compound, it is essential to know the characteristics of it when it is deposited in thin film form. The cells were created using pulsed laser deposition method for two separate mediums (first layers after ITO). ZnO was deposited onto ITO glass for the first sample. For the second sample, a layer of pure Molybdenum was deposited onto the ITO glass. The MnTiO3 was then deposited onto both samples. There was a target thickness of 1000 Angstroms, but ellipsometry shows that, for the Mo based sample, that film thickness was around 1500 Angstroms. There were inconclusive results for the ZnO based sample. The concentration of active carriers was measured using a Hall Effect apparatus for the Mo based sample. The XRD analyses were used to confirm the perovskite structure of the films. Measurements for photoelectric conversion efficiency were taken using a Keathley 2602 ScourceMeter indicated low values for efficiency. The structural information that is correlated with the low electrical performance of this sample will be discussed. SHU-NJSGC Summer 2015 Fellowship.

Characterization of Factors Affecting Nanoparticle Tracking Analysis Results With Synthetic and Protein Nanoparticles.

PubMed

Krueger, Aaron B; Carnell, Pauline; Carpenter, John F

2016-04-01

In many manufacturing and research areas, the ability to accurately monitor and characterize nanoparticles is becoming increasingly important. Nanoparticle tracking analysis is rapidly becoming a standard method for this characterization, yet several key factors in data acquisition and analysis may affect results. Nanoparticle tracking analysis is prone to user input and bias on account of a high number of parameters available, contains a limited analysis volume, and individual sample characteristics such as polydispersity or complex protein solutions may affect analysis results. This study systematically addressed these key issues. The integrated syringe pump was used to increase the sample volume analyzed. It was observed that measurements recorded under flow caused a reduction in total particle counts for both polystyrene and protein particles compared to those collected under static conditions. In addition, data for polydisperse samples tended to lose peak resolution at higher flow rates, masking distinct particle populations. Furthermore, in a bimodal particle population, a bias was seen toward the larger species within the sample. The impacts of filtration on an agitated intravenous immunoglobulin sample and operating parameters including "MINexps" and "blur" were investigated to optimize the method. Taken together, this study provides recommendations on instrument settings and sample preparations to properly characterize complex samples. Copyright © 2016. Published by Elsevier Inc.

Far-field optical imaging with subdiffraction resolution enabled by nonlinear saturation absorption

NASA Astrophysics Data System (ADS)

Ding, Chenliang; Wei, Jingsong

2016-01-01

The resolution of far-field optical imaging is required to improve beyond the Abbe limit to the subdiffraction or even the nanoscale. In this work, inspired by scanning electronic microscopy (SEM) imaging, in which carbon (or Au) thin films are usually required to be coated on the sample surface before imaging to remove the charging effect while imaging by electrons. We propose a saturation-absorption-induced far-field super-resolution optical imaging method (SAI-SRIM). In the SAI-SRIM, the carbon (or Au) layers in SEM imaging are replaced by nonlinear-saturation-absorption (NSA) thin films, which are directly coated onto the sample surfaces using advanced thin film deposition techniques. The surface fluctuant morphologies are replicated to the NSA thin films, accordingly. The coated sample surfaces are then imaged using conventional laser scanning microscopy. Consequently, the imaging resolution is greatly improved, and subdiffraction-resolved optical images are obtained theoretically and experimentally. The SAI-SRIM provides an effective and easy way to achieve far-field super-resolution optical imaging for sample surfaces with geometric fluctuant morphology characteristics.

Testing an Impedance Non-destructive Method to Evaluate Steel-Fiber Concrete Samples

NASA Astrophysics Data System (ADS)

Komarkova, Tereza; Fiala, Pavel; Steinbauer, Miloslav; Roubal, Zdenek

2018-02-01

Steel-fiber reinforced concrete is a composite material characterized by outstanding tensile properties and resistance to the development of cracks. The concrete, however, exhibits such characteristics only on the condition that the steel fibers in the final, hardened composite have been distributed evenly. The current methods to evaluate the distribution and concentration of a fiber composite are either destructive or exhibit a limited capability of evaluating the concentration and orientation of the fibers. In this context, the paper discusses tests related to the evaluation of the density and orientation of fibers in a composite material. Compared to the approaches used to date, the proposed technique is based on the evaluation of the electrical impedance Z in the band close to the resonance of the sensor-sample configuration. Using analytically expressed equations, we can evaluate the monitored part of the composite and its density at various depths of the tested sample. The method employs test blocks of composites, utilizing the resonance of the measuring device and the measured sample set; the desired state occurs within the interval of between f=3 kHz and 400 kHz.

Characteristics of officer-involved vehicle collisions in California

PubMed Central

Wolfe, Scott E.; Rojek, Jeff; Alpert, Geoff; Tiesman, Hope; James, Stephen

2016-01-01

Purpose The purpose of this paper is to examine the situational and individual officer characteristics of officer-involved vehicle collisions that result in fatality, injury, and non-injury outcomes. Design/methodology/approach Data on 35,840 vehicle collisions involving law enforcement officers in California occurring between January 2000 and December 2009 are examined. A descriptive analysis of collision characteristics is presented. Findings There were 39 officers killed by collisions over this study period and 7,684 officers who received some type injury. Incidents involving officers on motorcycles represented 39 percent of officer fatalities and 39 percent of severe injuries. In the case of fatalities, 33 percent of officers were reported as wearing seatbelts, 38 percent were not wearing a seatbelt, and seatbelt use was not stated in 29 percent of car fatalities. Research limitations/implications The findings only represent one state and the analysis is based on an estimated 86 percent of collisions that occurred during the study period due to missing data. Nonetheless, the results are based on a robust sample and address key limitations in the existing literature. Practical implications During the study period in California the estimated financial impact of collisions reached into the hundreds of millions of dollars when considering related fatality, injury, and vehicle damage costs combined. These impacts highlight the need for the law enforcement community to give greater attention to this issue. Originality/value At the time of this writing there was no published independent research that compares the situational and officer characteristics across fatality, injury, and non-injury outcomes in these events. The findings reported here will help inform emerging interest in this issue within the law enforcement, academic, and policy-making communities. PMID:26877704

Use of alpha spectroscopy for conducting rapid surveys of transuranic activity on air sample filters and smears.

PubMed

Hayes, Robert B; Peña, Adan M; Goff, Thomas E

2005-08-01

This paper demonstrates the utility of a portable alpha Continuous Air Monitor (CAM) as a bench top scalar counter for multiple sample types. These include using the CAM to count fixed air sample filters and radiological smears. In counting radiological smears, the CAM is used very much like a gas flow proportional counter (GFPC), albeit with a lower efficiency. Due to the typically low background in this configuration, the minimum detectable activity for a 5-min count should be in the range of about 10 dpm which is acceptably below the 20 dpm limit for transuranic isotopes. When counting fixed air sample filters, the CAM algorithm along with other measurable characteristics can be used to identify and quantify the presence of transuranic isotopes in the samples. When the radiological control technician wants to take some credit from naturally occurring radioactive material contributions due to radon progeny producing higher energy peaks (as in the case with a fixed air sample filter), then more elaborate techniques are required. The techniques presented here will generate a decision level of about 43 dpm for such applications. The calibration for this application should alternatively be done using the default values of channels 92-126 for region of interest 1. This can be done within 10 to 15 min resulting in a method to rapidly evaluate air filters for transuranic activity. When compared to the 1-h count technique described by , the technique presented in the present work demonstrates a technique whereby more than two thirds of samples can be rapidly shown (within 10 to 15 min) to be within regulatory compliant limits. In both cases, however, spectral quality checks are required to insure sample self attenuation is not a significant bias in the activity estimates. This will allow the same level of confidence when using these techniques for activity quantification as is presently available for air monitoring activity quantification using CAMs.

Radio Frequency Detection and Characterization of Water-Ethanol Solution through Spiral-Coupled Passive Micro-Resonator Sensor.

PubMed

Koirala, Gyan Raj; Dhakal, Rajendra; Kim, Eun-Seong; Yao, Zhao; Kim, Nam-Young

2018-04-03

We present a microfabricated spiral-coupled passive resonator sensor realized through integrated passive device (IPD) technology for the sensitive detection and characterization of water-ethanol solutions. In order to validate the performance of the proposed device, we explicitly measured and analyzed the radio frequency (RF) characteristics of various water-ethanol solution compositions. The measured results showed a drift in the resonance frequency from 1.16 GHz for deionized (DI) water to 1.68 GHz for the solution containing 50% ethanol, whereas the rejection level given by the reflection coefficient decreased from -29.74 dB to -14.81 dB. The obtained limit of detection was 3.82% volume composition of ethanol in solution. The derived loaded capacitance was 21.76 pF for DI water, which gradually decreased to 8.70 pF for the 50% ethanol solution, and the corresponding relative permittivity of the solution decreased from 80.14 to 47.79. The dissipation factor increased with the concentration of ethanol in the solution. We demonstrated the reproducibility of the proposed sensor through iterative measures of the samples and the study of surface morphology. Successive measurement of different samples had no overlapping and had very minimum bias between RF characteristics for each measured sample. The surface profile for bare sensors was retained after the sample test, resulting a root mean square (RMS) value of 11.416 nm as compared to 10.902 nm for the bare test. The proposed sensor was shown to be a viable alternative to existing sensors for highly sensitive water-ethanol concentration detection.

The influence of coating technologies on stress-strain characteristics of the sample at periodic loading

NASA Astrophysics Data System (ADS)

Zakharchenko, K. V.; Zubkov, V. P.; Kapustin, V. I.; Maksimovski, E. A.; Talanin, A. V.

2017-10-01

The article is devoted to the research on influence of coating technologies on stress-strain characteristics of a heterogeneous sample (the substrate-coating system) at periodic stress-controlled loading. The comparison of stress-strain characteristics of samples with three types of surface layer showed that the coatings lead to the change in stress at which inelastic phenomena appear in the material. Apart stress-strain characteristics of samples, microrelief on the samples’ surface and formation of a slipband in the grain structure of the coatings were studied in the experiment. It is stated that cold dynamic spraying, which is performed by centrifugal acceleration of particles in vacuum, makes it possible to obtain a coating with better strength and stress-strain characteristics in comparison with cladding.

The 23 to 300 C demagnetization resistance of samarium-cobalt permanent magnets

NASA Technical Reports Server (NTRS)

Niedra, Janis M.; Overton, Eric

1991-01-01

The influence of temperature on knee point and squareness of the M-H demagnetization characteristic of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperature in demagnetization resistent permanent magnet devices. Composite plots of the knee field and the demagnetizing field required to produce a given magnetic induction swing below remanence were obtained for several commercial Sm2Co17 type magnet samples in the temperature range of 23 to 300 C. Using the knee point to define the limits of operation safe against irreversible demagnetization, such plots are shown to provide an effective overview of the useable regions in the space of temperature-induction swing parameters. The observed second quadrant M-H characteristic squareness is shown, by two measures, to increase gradually with temperature, reaching a peak in the interval 200 to 300 C.

Psychological Characteristics in Acute Mild Traumatic Brain Injury: An MMPI-2 Study.

PubMed

Gass, Carlton S; Rogers, David; Kinne, Erica

2017-01-01

The psychological characteristics of acute traumatic brain injury (TBI) have received limited research focus, despite empirical evidence of their relevance for subsequent psychological adjustment and early therapeutic intervention. This study addressed a wide range of psychological features in 47 individuals who were hospitalized as a result of acute mild TBI (mTBI). Participants were screened from amongst consecutive TBI admissions for moderate to severe brain injury, and for pre-injury neurological, psychiatric, or substance abuse histories. Clinical and content scale scores on the MMPI-2 were explored in relation to patient gender, age, level of education, and extent of cognitive complaints. The results revealed diverse psychosocial problem areas across the sample, the most common of which were somatic and cognitive complaints, compromised insight, and a naively optimistic self-perception. The mediating roles of injury severity and demographic variables are discussed. Clinical implications and specific recommendations are presented.

Microgravity Smoldering Combustion on the USML-1 Space Shuttle Mission

NASA Technical Reports Server (NTRS)

Stocker, Dennis P.; Olson, Sandra L.; Torero, Jose L.; Fernandez-Pello, A Carlos

1994-01-01

Preliminary results from an experimental study of the smolder characteristics of a porous combustible material (flexible polyurethane foam) in normal and microgravity are presented. The experiments, limited in fuel sample size and power available for ignition, show that the smolder process was primarily controlled by heat losses from the reaction to the surrounding environment. In microgravity, the reduced heat losses due to the absence of natural convection result in only slightly higher temperatures in the quiescent microgravity test than in normal gravity but a dramatically larger production of combustion products in all microgravity tests. Particularly significant is the proportionately larger amount of carbon monoxide and light organic compounds produced in microgravity, despite comparable temperatures and similar char patterns. This excessive production of fuel-rich combustion products may be a generic characteristic of smoldering polyurethane in microgravity, with an associated increase in the toxic hazard of smolder in spacecraft.

Microgravity smoldering combustion on the USML-1 Space Shuttle mission

NASA Technical Reports Server (NTRS)

Stocker, Dennis P.; Olson, Sandra L.; Torero, Jose L.; Fernandez-Pello, A. Carlos

1995-01-01

Preliminary results from an experimental study of the smolder characteristics of a porous combustible material (flexible polyurethane foam) in normal and microgravity are presented. The experiments, limited in fuel sample size and power available for ignition, show that the smolder process was primarily controlled by heat losses from the reaction to the surrounding environment In microgravity, the reduced heat losses due to the absence of natural convection result in only slightly higher temperatures in the quiescent microgravity test than in normal gravity, but a dramatically larger production of combustion products in all microgravity tests. Particularly significant is the proportionately larger amount of carbon monoxide and light organic compounds produced in microgravity, despite comparable temperatures and similar char patterns. This excessive production of fuel-rich combustion products may be a generic characteristic of smoldering polyurethane in microgravity, with an associated increase in the toxic hazard of smolder in spacecraft.

Study on ground water characteristics and the effects of discharged effluents from textile units at Karur District.

PubMed

Kannan, V; Ramesh, R; Sasikumar, C

2005-04-01

A study was made on the physico-chemical characteristics of water samples mixed with effluent discharged from textile industries at Chellandipalayam (Site--I), Senaparatti (Site--II) and Pasupathipalayam (Sites--III and IV) revealed the elevated levels of Ca, Mg, Na, Cr, K, Ni, Cu, Zn, CO3, SO4, NO3 and Cl- . The concentrations of these ions exceeded the limit prescribed by ISI. The increase in the concentrations of ions was revealed by higher values of electrical conductivity (EC). Water at these sites was found to be hard, brackish and unsuitable for drinking purpose. In all these sites, the seed germination of rice alone was significantly affected among the other crops tested. Irrigation of crops with ground water notably lowered the quantity of reserve food in rice, wheat (starch), and sugarcane (sugar), indicating the interference of their metabolic pathway by polluted ground water.

Strong-acid, carboxyl-group structures in fulvic acid from the Suwannee River, Georgia. 1. Minor structures

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Reddy, M.M.

1995-01-01

An investigation of the strong-acid characteristics (pKa 3.0 or less) of fulvic acid from the Suwannee River, Georgia, was conducted. Quantitative determinations were made for amino acid and sulfur-containing acid structures, oxalate half-ester structures, malonic acid structures, keto acid structures, and aromatic carboxyl-group structures. These determinations were made by using a variety of spectrometric (13C-nuclear magnetic resonance, infrared, and ultraviolet spectrometry) and titrimetric characterizations on fulvic acid or fulvic acid samples that were chemically derivatized to indicate certain functional groups. Only keto acid and aromatic carboxyl-group structures contributed significantly to the strong-acid characteristics of the fulvic acid; these structures accounted for 43% of the strong-acid acidity. The remaining 57% of the strong acids are aliphatic carboxyl groups in unusual and/or complex configurations for which limited model compound data are available.

Community characteristics and implementation factors associated with effective systems of care.

PubMed

Lunn, Laurel M; Heflinger, Craig Anne; Wang, Wei; Greenbaum, Paul E; Kutash, Krista; Boothroyd, Roger A; Friedman, Robert M

2011-07-01

How are characteristics of communities associated with the implementation of the principles of systems of care (SOC)? This study uses multilevel modeling with a stratified random sample (N = 225) of US counties to explore community-level predictors of the implementation factors of the System of Care Implementation Survey. A model composed of community-level social indicators fits well with 5 of 14 factors identified as relevant for effective SOCs. As hypothesized, community disadvantage was negatively and residential stability positively associated with the implementation of SOC principles. Designation as a mental health professional shortage area was positively related to some implementation scores, as was the percentage of minority residents, while rurality was not significantly associated with any of the factors. Given the limitations of the study, the results should be interpreted with caution, but suggest that further research is merited to clarify these relationships that could inform efforts directed at promoting SOCs.

Martyrs' last letters: are they the same as suicide notes?

PubMed

Leenaars, Antoon A; Ben Park, B C; Collins, Peter I; Wenckstern, Susanne; Leenaars, Lindsey

2010-05-01

Of the 800,000 suicides worldwide every year, a small number fall under Emile Durkheim's term of altruistic suicides. Study on martyrdom has been limited. There has to date, for example, been no systematic empirical study of martyr letters. We examined 33 letters of Korean self-immolators, compared with 33 suicide notes of a matched sample of more common suicides. An analysis of intrapsychic factors (suicide as unbearable pain, psychopathology) and interpersonal factors (suicide as murderous impulses and need to escape) revealed that, although one can use the same psychological characteristics or dynamics to understand the deaths, the state of mind of martyrs is more extreme, such that the pain is reported to be even more unbearable. Yet, there are differences, such as there was no ambivalence in the altruistic notes. It is concluded that intrapsychic and interpersonal characteristics are central in understanding martyrs, probably equal to community or societal factors. More forensic study is, however, warranted.

Occurrence of Legionella in wastewater treatment plants linked to wastewater characteristics.

PubMed

Caicedo, C; Beutel, S; Scheper, T; Rosenwinkel, K H; Nogueira, R

2016-08-01

In recent years, the occurrence of Legionella in wastewater treatment plants (WWTP) has often been reported. However, until now there is limited knowledge about the factors that promote Legionella's growth in such systems. The aim of this study was to investigate the chemical wastewater parameters that might be correlated to the concentration of Legionella spp. in WWTP receiving industrial effluents. For this purpose, samples were collected at different processes in three WWTP. In 100 % of the samples taken from the activated sludge tanks Legionella spp. were detected at varying concentrations (4.8 to 5.6 log GU/mL) by the quantitative real-time polymerase chain reaction method, but not by the culture method. Statistical analysis with various parameters yielded positive correlations of Legionella spp. concentration with particulate chemical oxygen demand, Kjeldahl nitrogen and protein concentration. Amino acids were quantified in wastewater and activated sludge samples at concentrations that may not support the growth of Legionella, suggesting that in activated sludge tanks this bacterium multiplied in protozoan hosts.

Direct determination of graphene quantum dots based on terbium-sensitized luminescence.

PubMed

Llorent-Martínez, Eulogio J; Molina-García, Lucía; Durán, Gema M; Ruiz-Medina, Antonio; Ríos, Ángel

2018-06-05

Graphene quantum dots (GQD) were determined in water samples using terbium-sensitized luminescence (TSL). Terbium ions complex with GQD due to the carboxylic groups that are usually present in these nanomaterials, increasing the luminescence signal of terbium. In Tb(III)-GQD complexes, GQD absorb energy at their characteristic excitation wavelength and transfer it to terbium ion, which emits at its particular emission wavelength. The analytical signal, measured at λ exc =257nm and λ em =545nm, increases proportionally to GQD concentration between 50 and 500μgL -1 . Under optimum conditions, the proposed method presents a detection limit of 15μgL -1 and is selective to GQD in the presence of other nanomaterials of similar size. As GQD are highly water-soluble, they are potential contaminants in environmental or drinking waters water samples, and hence the method was applied to the analysis of different drinking waters which were the target samples for the application of the developed method. Copyright © 2018 Elsevier B.V. All rights reserved.

Chemical compositions, chromatographic fingerprints and antioxidant activities of Andrographis Herba.

PubMed

Zhao, Yang; Kao, Chun-Pin; Wu, Kun-Chang; Liao, Chi-Ren; Ho, Yu-Ling; Chang, Yuan-Shiun

2014-11-10

This paper describes the development of an HPLC-UV-MS method for quantitative determination of andrographolide and dehydroandrographolide in Andrographis Herba and establishment of its chromatographic fingerprint. The method was validated for linearity, limit of detection and quantification, inter- and intra-day precisions, repeatability, stability and recovery. All the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then applied to assay the contents of andrographolide and dehydroandrographolide and to acquire the fingerprints of all the collected Andrographis Herba samples. Furthermore, similarity analysis and principal component analysis were used to reveal the similarities and differences between the samples on the basis of the characteristic peaks. More importantly, the DPPH free radical-scavenging and ferric reducing capacities of the Andrographis Herba samples were assayed. By bivariate correlation analysis, we found that six compounds are positively correlated to DPPH free radical scavenging and ferric reducing capacities, and four compounds are negatively correlated to DPPH free radical scavenging and ferric reducing capacities.

Characterization of pine nuts in the U.S. market, including those associated with "pine mouth", by GC-FID.

PubMed

Fardin-Kia, Ali Reza; Handy, Sara M; Rader, Jeanne I

2012-03-14

Taste disturbances following consumption of pine nuts, referred to as "pine mouth", have been reported by consumers in the United States and Europe. Nuts of Pinus armandii have been associated with pine mouth, and a diagnostic index (DI) measuring the content of Δ5-unsaturated fatty acids relative to that of their fatty acid precursors has been proposed for identifying nuts from this species. A 100 m SLB-IL 111 GC column was used to improve fatty acid separations, and 45 pine nut samples were analyzed, including pine mouth-associated samples. This study examined the use of a DI for the identification of mixtures of pine nut species and showed the limitation of morphological characteristics for species identification. DI values for many commercial samples did not match those of known reference species, indicating that the majority of pine nuts collected in the U.S. market, including those associated with pine mouth, are mixtures of nuts from different Pinus species.

Direct determination of graphene quantum dots based on terbium-sensitized luminescence

NASA Astrophysics Data System (ADS)

Llorent-Martínez, Eulogio J.; Molina-García, Lucía; Durán, Gema M.; Ruiz-Medina, Antonio; Ríos, Ángel

2018-06-01

Graphene quantum dots (GQD) were determined in water samples using terbium-sensitized luminescence (TSL). Terbium ions complex with GQD due to the carboxylic groups that are usually present in these nanomaterials, increasing the luminescence signal of terbium. In Tb(III)-GQD complexes, GQD absorb energy at their characteristic excitation wavelength and transfer it to terbium ion, which emits at its particular emission wavelength. The analytical signal, measured at λexc = 257 nm and λem = 545 nm, increases proportionally to GQD concentration between 50 and 500 μg L-1. Under optimum conditions, the proposed method presents a detection limit of 15 μg L-1 and is selective to GQD in the presence of other nanomaterials of similar size. As GQD are highly water-soluble, they are potential contaminants in environmental or drinking waters water samples, and hence the method was applied to the analysis of different drinking waters which were the target samples for the application of the developed method.

Comparison of ion chromatographic methods based on conductivity detection, post-column-reaction and on-line-coupling IC-ICP-MS for the determination of bromate.

PubMed

Schminke, G; Seubert, A

2000-02-01

An established method for the determination of the disinfection by-product bromate is ion chromatography (IC). This paper presents a comparison of three IC methods based on either conductivity detection (IC-CD), a post-column-reaction (IC-PCR-VIS) or the on-line-coupling with inductively coupled plasma mass spectrometry (IC-ICP-MS). Main characteristics of the methods such as method detection limits (MDL), time of analysis and sample pretreatment are compared and applicability for routine analysis is critically discussed. The most sensitive and rugged method is IC-ICP-MS, followed by IC-PCR-VIS. The photometric detection is subject to a minor interference in real world samples, presumably caused by carbonate. The lowest sensitivity is shown by the IC-CD method as slowest method compared, which, in addition, requires a sample pretreatment. The highest amount of information is delivered by IC-PCR-VIS, which allows the simultaneous determination of the seven standard anions and bromate.

Field of first magnetic flux entry and pinning strength of superconductors for rf application measured with muon spin rotation

NASA Astrophysics Data System (ADS)

Junginger, T.; Abidi, S. H.; Maffett, R. D.; Buck, T.; Dehn, M. H.; Gheidi, S.; Kiefl, R.; Kolb, P.; Storey, D.; Thoeng, E.; Wasserman, W.; Laxdal, R. E.

2018-03-01

The performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry Hentry and pinning strength. The former sets the limit for the maximum achievable accelerating gradient, while the latter determines how efficiently flux can be expelled related to the maximum achievable quality factor. In this paper, a method based on muon spin rotation (μ SR ) is developed to probe these parameters on samples. It combines measurements from two different spectrometers, one being specifically built for these studies and samples of different geometries. It is found that annealing at 1400 °C virtually eliminates all pinning. Such an annealed substrate is ideally suited to measure Hentry of layered superconductors, which might enable accelerating gradients beyond bulk niobium technology.

A cross-sectional examination of non-suicidal self-injury, disordered eating, impulsivity, and compulsivity in a sample of adult women.

PubMed

Black, Emma B; Mildred, Helen

2014-12-01

Non-suicidal self-injury has been classed as having both impulsive and compulsive characteristics (Simeon & Favazza, 2001). These constructs have been related to disordered eating behaviors such as vomiting (Favaro & Santonastaso, 1998). Utilizing an international sample of adult females, this paper further explored this model, aiming to identify whether all types of disordered eating could be classified as impulsive or compulsive, and whether the impulsive and compulsive groupings reflect underlying trait impulsivity and compulsivity. The hypothesized impulsive and compulsive dimensions did not emerge from the data. Notably however, all self-injurious and disordered eating behaviors were linked to Urgency (an impulsivity facet) to varying degrees; no relationship with trait compulsivity was found. These findings are discussed, study limitations are noted, and relevance for clinical practice is outlined.

Variation in the limit-of-detection of the ProSpecT Campylobacter microplate enzyme immunoassay in stools spiked with emerging Campylobacter species.

PubMed

Bojanić, Krunoslav; Midwinter, Anne Camilla; Marshall, Jonathan Craig; Rogers, Lynn Elizabeth; Biggs, Patrick Jon; Acke, Els

2016-08-01

Campylobacter enteritis in humans is primarily associated with C. jejuni/coli infection. The impact of other Campylobacter spp. is likely to be underestimated due to the bias of culture methods towards Campylobacter jejuni/coli diagnosis. Stool antigen tests are becoming increasingly popular and appear generally less species-specific. A review of independent studies of the ProSpecT® Campylobacter Microplate enzyme immunoassay (EIA) developed for C. jejuni/coli showed comparable diagnostic results to culture methods but the examination of non-jejuni/coli Campylobacter spp. was limited and the limit-of-detection (LOD), where reported, varied between studies. This study investigated LOD of EIA for Campylobacter upsaliensis, Campylobacter hyointestinalis and Campylobacter helveticus spiked in human stools. Multiple stools and Campylobacter isolates were used in three different concentrations (10(4)-10(9)CFU/ml) to reflect sample heterogeneity. All Campylobacter species evaluated were detectable by EIA. Multivariate analysis showed LOD varied between Campylobacter spp. and faecal consistency as fixed effects and individual faecal samples as random effects. EIA showed excellent performance in replicate testing for both within and between batches of reagents, in agreement between visual and spectrophotometric reading of results, and returned no discordance between the bacterial concentrations within independent dilution test runs (positive results with lower but not higher concentrations). This study shows how limitations in experimental procedures lead to an overestimation of consistency and uniformity of LOD for EIA that may not hold under routine use in diagnostic laboratories. Benefits and limitations for clinical practice and the influence on estimates of performance characteristics from detection of multiple Campylobacter spp. by EIA are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Field substitution of nonresponders can maintain sample size and structure without altering survey estimates-the experience of the Italian behavioral risk factors surveillance system (PASSI).

PubMed

Baldissera, Sandro; Ferrante, Gianluigi; Quarchioni, Elisa; Minardi, Valentina; Possenti, Valentina; Carrozzi, Giuliano; Masocco, Maria; Salmaso, Stefania

2014-04-01

Field substitution of nonrespondents can be used to maintain the planned sample size and structure in surveys but may introduce additional bias. Sample weighting is suggested as the preferable alternative; however, limited empirical evidence exists comparing the two methods. We wanted to assess the impact of substitution on surveillance results using data from Progressi delle Aziende Sanitarie per la Salute in Italia-Progress by Local Health Units towards a Healthier Italy (PASSI). PASSI is conducted by Local Health Units (LHUs) through telephone interviews of stratified random samples of residents. Nonrespondents are replaced with substitutes randomly preselected in the same LHU stratum. We compared the weighted estimates obtained in the original PASSI sample (used as a reference) and in the substitutes' sample. The differences were evaluated using a Wald test. In 2011, 50,697 units were selected: 37,252 were from the original sample and 13,445 were substitutes; 37,162 persons were interviewed. The initially planned size and demographic composition were restored. No significant differences in the estimates between the original and the substitutes' sample were found. In our experience, field substitution is an acceptable method for dealing with nonresponse, maintaining the characteristics of the original sample without affecting the results. This evidence can support appropriate decisions about planning and implementing a surveillance system. Copyright © 2014 Elsevier Inc. All rights reserved.

Leaching characteristics of copper flotation waste before and after vitrification.

PubMed

Coruh, Semra; Ergun, Osman Nuri

2006-12-01

Copper flotation waste from copper production using a pyrometallurgical process contains toxic metals such as Cu, Zn, Co and Pb. Because of the presence of trace amounts of these highly toxic metals, copper flotation waste contributes to environmental pollution. In this study, the leaching characteristics of copper flotation waste from the Black Sea Copper Works in Samsun, Turkey have been investigated before and after vitrification. Samples obtained from the factory were subjected to toxicity tests such as the extraction procedure toxicity test (EP Tox), the toxicity characteristic leaching procedure (TCLP) and the "method A" extraction procedure of the American Society of Testing and Materials. The leaching tests showed that the content of some elements in the waste before vitrification exceed the regulatory limits and cannot be disposed of in the present form. Therefore, a stabilization or inertization treatment is necessary prior to disposal. Vitrification was found to stabilize heavy metals in the copper flotation waste successfully and leaching of these metals was largely reduced. Therefore, vitrification can be an acceptable method for disposal of copper flotation waste.

The Effect of Small Additions of Carbon Nanotubes on the Mechanical Properties of Epoxy Polymers under Static and Dynamic Loads

NASA Astrophysics Data System (ADS)

Tarasov, A. E.; Badamshina, E. R.; Anokhin, D. V.; Razorenov, S. V.; Vakorina, G. S.

2018-01-01

The results of measurements of the mechanical characteristics of cured epoxy composites containing small and ultrasmall additions of single-walled carbon nanotubes in the concentration range from 0 to 0.133 wt % under static and dynamic loads are presented. Static measurements of strength characteristics have been carried out under standard test conditions. Measurements of the Hugoniot elastic limit and spall strength were performed under a shock wave loading of the samples at a deformation rate of (0.8-1.5) ß 105 s-1 before the fracture using explosive devices by recording and subsequent analyzing the evolution of the full wave profiles. It has been shown that agglomerates of nanotubes present in the structure of the composites after curing cause a significant scatter of the measured strength parameters, both in the static and in the dynamic test modes. However, the effects of carbon nanotube additions in the studied concentration interval on the physical and mechanical characteristics of the parameters were not revealed for both types of loading.

Environmental justice in the context of commuters' exposure to CO and PM10 in Bangalore, India.

PubMed

Sabapathy, Ashwin; Saksena, Sumeet; Flachsbart, Peter

2015-01-01

The Information Technology (IT) industry in the globalizing city of Bangalore has transformed the socio-economic characteristics of the city. The intent of this study, developed from an environmental justice framework, was to determine whether air pollutant exposure while commuting to and from work is related to a commuter's income characteristics and whether differences are larger for the IT economy when compared with a traditional manufacturing-oriented economy of the city. The study measured exposures to CO and PM10 using personal samplers for a sample of employees of a traditional public sector manufacturing industry (n=20) and an IT industry (n=26). This approach overcomes the methodological limitations of previous environmental justice studies. Socio-economic characteristics were obtained from a questionnaire-based survey of 436 employees in two firms. The results do not support the environmental justice hypothesis for commuting in Bangalore mainly because longer commuting times of higher-income groups offsets the benefits of lower pollutant concentrations. The study nevertheless demonstrates the use of personal exposure for environmental justice assessments.

Racial Inequality in Education in Brazil: A Twins Fixed-Effects Approach.

PubMed

Marteleto, Letícia J; Dondero, Molly

2016-08-01

Racial disparities in education in Brazil (and elsewhere) are well documented. Because this research typically examines educational variation between individuals in different families, however, it cannot disentangle whether racial differences in education are due to racial discrimination or to structural differences in unobserved neighborhood and family characteristics. To address this common data limitation, we use an innovative within-family twin approach that takes advantage of the large sample of Brazilian adolescent twins classified as different races in the 1982 and 1987-2009 Pesquisa Nacional por Amostra de Domicílios. We first examine the contexts within which adolescent twins in the same family are labeled as different races to determine the characteristics of families crossing racial boundaries. Then, as a way to hold constant shared unobserved and observed neighborhood and family characteristics, we use twins fixed-effects models to assess whether racial disparities in education exist between twins and whether such disparities vary by gender. We find that even under this stringent test of racial inequality, the nonwhite educational disadvantage persists and is especially pronounced for nonwhite adolescent boys.

Racial Inequality in Education in Brazil: A Twins Fixed-Effects Approach

PubMed Central

Marteleto, Letícia; Dondero, Molly

2016-01-01

Racial disparities in education in Brazil (and elsewhere) are well documented. Because this research typically examines educational variation between individuals in different families, however, it cannot disentangle whether racial differences in education are due to racial discrimination or to structural differences in unobserved neighborhood and family characteristics. To address this common data limitation, we use an innovative within-family twin approach that takes advantage of the large sample of Brazilian adolescent twins classified as different races in the 1982 and 1987–2009 Pesquisa Nacional por Amostra de Domicílios. We first examine the contexts within which adolescent twins in the same family are labeled as different races to determine the characteristics of families crossing racial boundaries. Then, as a way to hold constant shared unobserved and observed neighborhood and family characteristics, we use twins fixed-effects models to assess whether racial disparities in education exist between twins and whether such disparities vary by gender. We find that even under this stringent test of racial inequality, the nonwhite educational disadvantage persists and is especially pronounced for nonwhite adolescent boys. PMID:27443551

Impact of Leachate Discharge from Cipayung Landfill on Water Quality of Pesanggrahan River, Indonesia

NASA Astrophysics Data System (ADS)

Noerfitriyani, Eki; Hartono, Djoko M.; Moersidik, Setyo S.; Gusniani, Irma

2018-03-01

The landfill operation can cause environmental problems due to solid waste decomposition in the form of leachate. The evaluation of environmental impacts related with solid waste landfilling is needed to ensure that leachate discharge to water bodies does not exceed the standard limit to prevent contamination of the environment. This study aims to analyze the impact of leachate discharge from Cipayung Landfill on water quality of Pesanggrahan River. The data were analyzed based on leachate samples taken from influent and effluent treatment unit, and river water samples taken from upstream, stream at leachate discharge, and downstream. All samples were taken three times under rainy season condition from April to May 2017. The results show the average leachate quality temperature is 34,81 °C, TSS 72.33 mg/L, pH 7.83, BOD 3,959.63 mg/L, COD 6,860 mg/L, TN 373.33 mg/L, Hg 0.0016 mg/L. The BOD5/COD ratio 0.58 indicated that leachate characteristics was biodegradable and resemble intermediate landfill due to the mixing of young leachate and old leachate. The effluent of leachate treatment plant exceeds the leachate standard limit for BOD, COD, and TN parameters. Statistical results from independent T-test showed significant differences (p<0,05) between upstream and downstream influenced with leachate discharge for DO parameter.

Picoelectrospray Ionization Mass Spectrometry Using Narrow-bore Chemically Etched Emitters

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

Marginean, Ioan; Tang, Keqi; Smith, Richard D.

2014-01-01

Electrospray ionization mass spectrometry (ESI-MS) at flow rates below ~10 nL/min has been only sporadically explored due to difficulty in reproducibly fabricating emitters that can operate at lower flow rates. Here we demonstrate narrow orifice chemically etched emitters for stable electrospray at flow rates as low as 400 pL/min. Depending on the analyte concentration, we observe two types of MS signal response as a function of flow rate. At low concentrations, an optimum flow rate is observed slightly above 1 nL/min, while the signal decreases monotonically with decreasing flow rates at higher concentrations. In spite of lower MS signal, themore » ion utilization efficiency increases exponentially with decreasing flow rate in all cases. No unimolecular response was observed within this flow rate range during the analysis of an equimolar mixture of peptides, indicating that ionization efficiency is an analyte-dependent characteristic in given experimental conditions. While little to no gain in signal-to-noise was achieved at ultralow flow rates for concentration-limited analyses, experiments consuming the same amount of analyte suggest that mass-limited analyses will benefit strongly from the use of low flow rates and avoiding unnecessary sample dilution. By operating under optimal conditions, consumption of just 500 zmol of sample yielded signal-to-noise ratios ~10 for some peptides. These findings have important implications for the analysis of trace biological samples.« less

Facile preparation of magnetic molecularly imprinted polymers for the selective extraction and determination of dexamethasone in skincare cosmetics using HPLC.

PubMed

Du, Wei; Zhang, Bilin; Guo, Pengqi; Chen, Guoning; Chang, Chun; Fu, Qiang

2018-03-15

Dexamethasone-imprinted polymers were fabricated by reversible addition-fragmentation chain transfer polymerization on the surface of magnetic nanoparticles under mild polymerization conditions, which exhibited a narrow polydispersity and high selectivity for dexamethasone extraction. The dexamethasone-imprinted polymers were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometry, and vibrating sample magnetometry. The adsorption performance was evaluated by static adsorption, kinetic adsorption and selectivity tests. The results confirmed the successful construction of an imprinted polymer layer on the surface of the magnetic nanoparticles, which benefits the characteristics of high adsorption capacity, fast mass transfer, specific molecular recognition, and simple magnetic separation. Combined with high-performance liquid chromatography, molecularly imprinted polymers as magnetic extraction sorbents were used for the rapid and selective extraction and determination of dexamethasone in skincare cosmetic samples, with the accuracies of the spiked samples ranging from 93.8 to 97.6%. The relative standard deviations were less than 2.7%. The limit of detection and limit of quantification were 0.05 and 0.20 μg/mL, respectively. The developed method was simple, fast and highly selective and could be a promising method for dexamethasone monitoring in cosmetic products. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid diagnosis of Theileria annulata by recombinase polymerase amplification combined with a lateral flow strip (LF-RPA) in epidemic regions.

PubMed

Yin, Fangyuan; Liu, Junlong; Liu, Aihong; Li, Youquan; Luo, Jianxun; Guan, Guiquan; Yin, Hong

2017-04-15

Rapid and accurate diagnosis of Theileria annulata infection contributes to the formulation of strategies to eradicate this parasite. A simple and efficient diagnostic tool, recombinase polymerase amplification (RPA) combined with a lateral flow (LF) strip, was used in detection of Theileria and compared to other methods that require expensive instruments and skilled personnel. Herein, we established and optimized an LF-RPA method to detect the cytochrome b gene of T. annulata mitochondrial DNA from experimentally infected and field-collected blood samples. This method has many unparalleled characteristics, including that it is rapid (clear detection in 5min at constant temperature), sensitive (the limitation of detection is at least 2pg genomic DNA), and specific (no cross-reaction with other piroplasms that infect cattle). The LF-RPA assay was evaluated via testing 17 field blood samples and comparing the results of that of a PCR, showing 100% agreement, which demonstrates the ability of the LF-RPA assay to detect T. annulata infections in small number of samples (n=17). Taken together, the results indicate that this method could be used as an ideal diagnostic tool for detecting T. annulata in endemic regions with limited to fewer and local resources and could also be a potential technique for the surveillance and control of blood protozoa. Copyright © 2017 Elsevier B.V. All rights reserved.

Dimensional assessment of personality pathology in patients with eating disorders.

PubMed

Goldner, E M; Srikameswaran, S; Schroeder, M L; Livesley, W J; Birmingham, C L

1999-02-22

This study examined patients with eating disorders on personality pathology using a dimensional method. Female subjects who met DSM-IV diagnostic criteria for eating disorder (n = 136) were evaluated and compared to an age-controlled general population sample (n = 68). We assessed 18 features of personality disorder with the Dimensional Assessment of Personality Pathology - Basic Questionnaire (DAPP-BQ). Factor analysis and cluster analysis were used to derive three clusters of patients. A five-factor solution was obtained with limited intercorrelation between factors. Cluster analysis produced three clusters with the following characteristics: Cluster 1 members (constituting 49.3% of the sample and labelled 'rigid') had higher mean scores on factors denoting compulsivity and interpersonal difficulties; Cluster 2 (18.4% of the sample) showed highest scores in factors denoting psychopathy, neuroticism and impulsive features, and appeared to constitute a borderline psychopathology group; Cluster 3 (32.4% of the sample) was characterized by few differences in personality pathology in comparison to the normal population sample. Cluster membership was associated with DSM-IV diagnosis -- a large proportion of patients with anorexia nervosa were members of Cluster 1. An empirical classification of eating-disordered patients derived from dimensional assessment of personality pathology identified three groups with clinical relevance.

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.

OXTR polymorphism in depression and completed suicide-A study on a large population sample.

PubMed

Wasilewska, Krystyna; Pawlak, Aleksandra; Kostrzewa, Grażyna; Sobczyk-Kopcioł, Agnieszka; Kaczorowska, Aleksandra; Badowski, Jarosław; Brzozowska, Małgorzata; Drygas, Wojciech; Piwoński, Jerzy; Bielecki, Wojciech; Płoski, Rafał

2017-03-01

In the light of contradictory results concerning OXTR polymorphism rs53576 and depression, we decided to verify the potential association between the two on 1) a large, ethnically homogenous sample of 1185 individuals who completed the Beck Depression Inventory (BDI), as well as on 2) a sample of 763 suicide victims. In the population sample, AA males showed significantly lower BDI scores (p=0.005, p cor =0.030). Exploratory analyses suggested that this effect was limited to a subgroup within 0-9 BDI score range (p=0.0007, U-Mann Whitney test), whereas no main effect on depressive symptoms (BDI>9) was found. In the suicide sample no association with rs53576 genotype was present. Exploratory analyses in suicides revealed higher blood alcohol concentration (BAC) among AA than GG/GA males (p=0.014, U-Mann Whitney test). Our results show that the OXTR rs53576 variant modulates the mood in male individuals and may positively correlate with alcohol intake among male suicides, but is not associated with suicide or depression. The study adds to the growing knowledge on rs53576 genotype characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Earnings of the internationally educated nurses in the U.S. labor market.

PubMed

Walani, Salimah R

2013-01-01

Internationally educated registered nurses comprise 5.4% of the U.S. nursing workforce. These nurses perceive unequal treatment in the workplace. However, studies comparing their wages to U.S.-educated registered nurses are limited and inconclusive. It is unclear whether there is a wage differential in the U.S. labor market. The aims of this study were to determine if there is a difference in the wages of internationally and U.S.-educated nurses and to determine the extent to which the wage gap relates to differences in the human capital, employment, and demographic characteristics of the two groups. The 2008 National Sample Survey of Registered Nurses data were used for this secondary data analysis study. The sample included 988 internationally educated nurses and 21,715 U.S.-educated nurses. Multiple regression and Oaxaca decomposition were used to find predictors of log hourly wages. Internationally educated nurses earned 5% higher log hourly wages, controlling for human capital, employment, and demographic characteristics. Male gender, working in a metropolitan area, hospital job, union representation, higher nursing experience, and higher education exerted significant positive effects on hourly wages. Oaxaca decomposition showed that 67% of the wage differential was because of the differences in the characteristics of two groups. If there is any form of discrimination against internationally educated nurses in the United States, it does not translate into wage inequality. Predictors of economic success should be explored in future research.

Predictors of retest effects in a longitudinal study of cognitive aging in a diverse community-based sample

PubMed Central

Gross, Alden L.; Benitez, Andreana; Shih, Regina; Bangen, Katherine J.; Glymour, M Maria M; Sachs, Bonnie; Sisco, Shannon; Skinner, Jeannine; Schneider, Brooke C.; Manly, Jennifer J.

2016-01-01

OBJECTIVE Better performance due to repeated testing can bias long-term trajectories of cognitive aging and correlates of change. We examined whether retest effects differ as a function of individual differences pertinent to cognitive aging: race/ethnicity, age, sex, language, years of education, and dementia risk factors including APOE ε4 status, baseline cognitive performance, and cardiovascular risk. METHOD We used data from the Washington Heights-Inwood Columbia Aging Project, a community-based cohort of older adults (n=4,073). We modeled cognitive change and retest effects in summary factors for general cognitive performance, memory, executive functioning, and language using multilevel models. Retest effects were parameterized in two ways, as improvement between the first and subsequent testings, and as the square root of the number of prior testings. We evaluated whether the retest effect differed by individual characteristics. RESULTS The mean retest effect for general cognitive performance was 0.60 standard deviations (95%CI: 0.46, 0.74), and was similar for memory, executive functioning, and language. Retest effects were greater for participants in the lowest quartile of cognitive performance, consistent with regression to the mean. Retest did not differ by other characteristics. CONCLUSIONS Retest effects are large in this community-based sample, but do not vary by demographic or dementia-related characteristics. Differential retest effects may not limit the generalizability of inferences across different groups in longitudinal research. PMID:26527240

Assessment of Characteristic Function Modulus of Vibroacoustic Signal Given a Limit State Parameter of Diagnosed Equipment

NASA Astrophysics Data System (ADS)

Kostyukov, V. N.; Naumenko, A. P.; Kudryavtseva, I. S.

2018-01-01

Improvement of distinguishing criteria, determining defects of machinery and mechanisms, by vibroacoustic signals is a recent problem for technical diagnostics. The work objective is assessment of instantaneous values by methods of statistical decision making theory and risk of regulatory values of characteristic function modulus. The modulus of the characteristic function is determined given a fixed parameter of the characteristic function. It is possible to determine the limits of the modulus, which correspond to different machine’s condition. The data of the modulus values are used as diagnostic features in the vibration diagnostics and monitoring systems. Using such static decision-making methods as: minimum number of wrong decisions, maximum likelihood, minimax, Neumann-Pearson characteristic function modulus limits are determined, separating conditions of a diagnosed object.

Electrofracturing test system and method of determining material characteristics of electrofractured material samples

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

Bauer, Stephen J.; Glover, Steven F.; Pfeifle, Tom

A device for electrofracturing a material sample and analyzing the material sample is disclosed. The device simulates an in situ electrofracturing environment so as to obtain electrofractured material characteristics representative of field applications while allowing permeability testing of the fractured sample under in situ conditions.

Monitoring Physicochemical and Nutrient Dynamics Along a Development Gradient in Maine Ephemeral Wetlands

NASA Astrophysics Data System (ADS)

Podzikowski, L. Y.; Capps, K. A.; Calhoun, A.

2014-12-01

Vernal pools are ephemeral wetlands in forested landscapes that fill with snowmelt, precipitation, and/or groundwater in the spring, and characteristically dry down through the summer months. Typically, vernal pool research has focused on the population and community ecology of pool-breeding organisms (amphibians and macroinvertebrates) conducted during their relatively short breeding season. Yet, little is known about the temporal variability of biogeochemical processes within and among vernal pools in urbanizing landscapes. In this study, we monitored physicochemical characteristics and nutrient dynamics in 22 vernal pools in central Maine post thaw in 2014. Four pristine pools were sampled weekly in five locations within the pool for ambient nutrient concentrations (SRP, NH4, NOx) and at three locations for physicochemical characteristics (DO, pH, temperature, conductivity). In the remaining 18 pools, we sampled one location for nutrients and three locations for physicochemical characteristics at least monthly to estimate the influence of increasing urbanization on the physical and chemical environment. Our data suggest most pools found in urbanizing areas have higher conductivity (developed sites ranging 18.52 - 1238 μS cm-1 compared to pristine between 14.08 - 58.4 μS cm-1). Previous work suggests forested pools exhibit dystrophic conditions with high coloration from DOC limiting primary production due to increased light attenuation in pools. However, both pristine and urban pools experienced spikes in DO (>100% saturation) throughout the day, suggesting that high productivity is not a reliable indicator of the effects of urbanization on vernal pools. We argue that continued monitoring of vernal pools along a gradient of urbanization could give insight into the role of ephemeral wetlands as potential biogeochemical hotspots and may also indicate how human development may alter biogeochemical cycling in ephemeral wetlands.

Reconnaissance of chemical and physical characteristics of selected bottom sediments of the Caloosahatchee River and estuary, tributaries, and contiguous bays, Lee County, Florida, July 20-30, 1998

USGS Publications Warehouse

Fernandez, Mario; Marot, M.E.; Holmes, C.W.

1999-01-01

This report summarizes a reconnaissance study, conducted July 20-30, 1998, of chemical and physical characteristics of recently deposited bottom sediments in the Caloosahatchee River and Estuary. Recently deposited sediments were identified using an isotopic chronometer, Beryllium-7 (7Be), a short-lived radioisotope. Fifty-nine sites were sampled in an area that encompasses the Caloosahatchee River (River) about three miles upstream from the Franklin Lock (S-79), the entire tidally affected length of the river (estuary), and the contiguous water bodies of Matlacha Pass, San Carlos Bay, Estero Bay, Tarpon Bay, and Pine Island Sound in Lee County, Florida. Bottom sediments were sampled for 7Be at 59 sites. From the results of the 7Be analysis, 30 sites were selected for physical and chemical analysis. Sediments were analyzed for particle size, total organic carbon (TOC), trace elements, and toxic organic compounds, using semiquantitative methods for trace elements and organic compounds. The semiquantitative scans of trace elements indicated that cadmium, copper, lead, and zinc concentrations, when normalized to aluminum, were above the natural background range at 24 of 30 sites. Particle size and TOC were used to characterize sediment deposition patterns and organic content. Pesticides, polychlorinated biphenyls (PCBs), and carcinogenic polycyclic aromatic hydrocarbons (CaPAHs) were determined at 30 sites using immunoassay analysis. The semiquantitative immunoassay analyses of toxic organic compounds indicated that all of the samples contained DDT, cyclodienes as chlordane (pesticides), and CaPAHs. PCBs were not detected. Based on analyses of the 30 sites, sediments at 10 of these sites were analyzed for selected trace elements and toxic organic compounds, including pesticides, PCBs, and PAHs, using quantitative laboratory procedures. No arsenic or cadmium was detected. Zinc was detected at two sites with concentrations greater than the lower limit of the range of sediment contaminant concentrations that are usually or always associated with adverse effects (Florida Department of Environmental Protection's Sediment Quality Assessment Guidelines). Organochlorine pesticides were detected at four sites at concentrations below the reporting limits; there were no organophosphorus pesticides or PCBs detected. PAHs were detected at eight sites; however, only four sites had concentrations above the reporting limit.

Dynamic full-field infrared imaging with multiple synchrotron beams

PubMed Central

Stavitski, Eli; Smith, Randy J.; Bourassa, Megan W.; Acerbo, Alvin S.; Carr, G. L.; Miller, Lisa M.

2013-01-01

Microspectroscopic imaging in the infrared (IR) spectral region allows for the examination of spatially resolved chemical composition on the microscale. More than a decade ago, it was demonstrated that diffraction limited spatial resolution can be achieved when an apertured, single pixel IR microscope is coupled to the high brightness of a synchrotron light source. Nowadays, many IR microscopes are equipped with multi-pixel Focal Plane Array (FPA) detectors, which dramatically improve data acquisition times for imaging large areas. Recently, progress been made toward efficiently coupling synchrotron IR beamlines to multi-pixel detectors, but they utilize expensive and highly customized optical schemes. Here we demonstrate the development and application of a simple optical configuration that can be implemented on most existing synchrotron IR beamlines in order to achieve full-field IR imaging with diffraction-limited spatial resolution. Specifically, the synchrotron radiation fan is extracted from the bending magnet and split into four beams that are combined on the sample, allowing it to fill a large section of the FPA. With this optical configuration, we are able to oversample an image by more than a factor of two, even at the shortest wavelengths, making image restoration through deconvolution algorithms possible. High chemical sensitivity, rapid acquisition times, and superior signal-to-noise characteristics of the instrument are demonstrated. The unique characteristics of this setup enabled the real time study of heterogeneous chemical dynamics with diffraction-limited spatial resolution for the first time. PMID:23458231

Chronic retinal necrosis: cytomegalovirus necrotizing retinitis associated with panretinal vasculopathy in non-HIV patients.

PubMed

Schneider, Eric W; Elner, Susan G; van Kuijk, Frederik J; Goldberg, Naomi; Lieberman, Ronni M; Eliott, Dean; Johnson, Mark W

2013-10-01

To characterize a unique cytomegalovirus (CMV)-associated retinopathy in patients with limited immune dysfunction. Retrospective observational case series. CMV was confirmed as the pathogenic agent via polymerase chain reaction analysis of aqueous or vitreous humor samples or via immunohistochemical analysis of retinal biopsy specimens. Five non-HIV patients with granular necrotizing retinitis, vitritis, and severe occlusive vasculopathy were identified. Patient histories all suggested a basis for limited immune dysfunction including advanced age (n = 4), diabetes mellitus (n = 4), and noncytotoxic immunotherapy (n = 3). Diagnosis of CMV retinitis was delayed in all cases and patients received either no antiviral therapy (n = 2) or incorrect antiviral therapy (n = 3) for presumed herpes simplex/varicella zoster-related acute retinal necrosis. Retinitis subsequently regressed in all cases with introduction of systemic ganciclovir/valganciclovir (n = 5) and/or intravitreal foscarnet (n = 2). Four of five patients developed neovascularization because of extensive retinal ischemia. The clinical expression of CMV-associated retinopathy is strongly related to immune status. In patients with limited immune dysfunction, a mixed clinical picture of intraocular inflammation with panretinal occlusive vasculopathy, more characteristic of acute retinal necrosis, and peripheral slowly progressive granular retinitis, more characteristic of classic CMV retinitis, is observed. Recognition of this atypical clinical presentation, which the authors term chronic retinal necrosis, should prompt molecular testing for CMV to determine the appropriate antiviral therapy. Consideration should also be given to prophylactic panretinal photocoagulation in such eyes, given the high risk of neovascular complications.

Age Life Evaluation of Space Shuttle Crew Escape System Pyrotechnic Components Loaded with Hexanitrostilbene (HNS)

NASA Technical Reports Server (NTRS)

Hoffman, William C., III

1996-01-01

Determining deterioration characteristics of the Space Shuttle crew escape system pyrotechnic components loaded with hexanitrostilbene would enable us to establish a hardware life-limit for these items, so we could better plan our equipment use and, possibly, extend the useful life of the hardware. We subjected components to accelerated-age environments to determine degradation characteristics and established a hardware life-limit based upon observed and calculated trends. We extracted samples using manufacturing lots currently installed in the Space Shuttle crew escape system and from other NASA programs. Hardware included in the study consisted of various forms and ages of mild detonating fuse, linear shaped charge, and flexible confined detonating cord. The hardware types were segregated into 5 groups. One was subjected to detonation velocity testing for a baseline. Two were first subjected to prolonged 155 F heat exposure, and the other two were first subjected to 255 F, before undergoing detonation velocity testing and/or chromatography analysis. Test results showed no measurable changes in performance to allow a prediction of an end of life given the storage and elevated temperature environments the hardware experiences. Given the lack of a definitive performance trend, coupled with previous tests on post-flight Space Shuttle hardware showing no significant changes in chemical purity or detonation velocity, we recommend a safe increase in the useful life of the hardware to 20 years, from the current maximum limits of 10 and 15 years, depending on the hardware.

Ballistic projectile trajectory determining system

DOEpatents

Karr, Thomas J.

1997-01-01

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

Element contents in leaves of four plant species (birch, mountain ash, fern and spruce) along anthropogenic and geogenic concentration gradients.

PubMed

Reimann, Clemens; Arnoldussen, Arnold; Boyd, Rognvald; Finne, Tor Erik; Koller, Friedrich; Nordgulen, Øystein; Englmaier, Peter

2007-05-15

Forty samples each of leaves of birch (Betula pubescens Ehrh.), European mountain ash (Sorbus aucuparia (L.)) and bracken fern (Pteridium aquilinum (L.) Kuhn) as well as spruce needles (Picea abies (L.) Karsten) were collected along a 120 km south-north transect running through Norway's largest city, Oslo. Concentrations of 25 chemical elements (Ag, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) as well as loss on ignition for the 4 sample materials are reported. The decline of input of sea spray with distance from the coast, geology, pH and anthropogenic contamination all played a role for the observed element concentrations in the leaves. Although growing under exactly the same natural conditions each plant species displayed quite unique uptake characteristics. Plant-species dependency and individual differences in the reaction of the plant leaves to different element sources make the investigated species of very limited value as bioindicators of anthropogenic activities. Anthropogenic contamination influences plant-leaf element content within a limited distance ( approximately 20 km) from the source.

Continuous motion scan ptychography: Characterization for increased speed in coherent x-ray imaging

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

Deng, Junjing; Nashed, Youssef S. G.; Chen, Si

Ptychography is a coherent diffraction imaging (CDI) method for extended objects in which diffraction patterns are acquired sequentially from overlapping coherent illumination spots. The object’s complex transmission function can be reconstructed from those diffraction patterns at a spatial resolution limited only by the scattering strength of the object and the detector geometry. Most experiments to date have positioned the illumination spots on the sample using a move-settle-measure sequence in which the move and settle steps can take longer to complete than the measure step. We describe here the use of a continuous “fly-scan” mode for ptychographic data collection in whichmore » the sample is moved continuously, so that the experiment resembles one of integrating the diffraction patterns from multiple probe positions. This allows one to use multiple probe mode reconstruction methods to obtain an image of the object and also of the illumination function. We show in simulations, and in x-ray imaging experiments, some of the characteristics of fly-scan ptychography, including a factor of 25 reduction in the data acquisition time. This approach will become increasingly important as brighter x-ray sources are developed, such as diffraction limited storage rings.« less

Temperament and personality in bipolar II disorder.

PubMed

Fletcher, Kathryn; Parker, Gordon; Barrett, Melissa; Synnott, Howe; McCraw, Stacey

2012-02-01

There is limited research examining temperament and personality in bipolar II disorder. We sought to determine any over-represented temperament and personality features in bipolar II disorder compared to other affective groups. Scores on a self-report measure of temperament and personality were examined in a sample of 443 participants diagnosed with unipolar, bipolar I and bipolar II disorder. After controlling for age, gender, age of depression onset and current depression severity, those with bipolar II disorder were characterized by higher irritability, anxious worrying, self-criticism and interpersonal sensitivity scores, and with lower social avoidance scores compared to unipolar participants. No differences were found between bipolar sub-types on any temperament and personality sub-scales. Limitations included the lack of a control group, a relatively small sample of bipolar I participants, and with the cross-sectional design disallowing conclusions regarding premorbid personality traits as opposed to illness 'scarring' effects. Further research should seek to clarify whether certain temperament and personality styles are over-represented in bipolar II disorder. Any over-represented characteristics may assist with diagnostic differentiation from phenomenologically similar conditions and lead to more appropriate clinical management. Copyright © 2011 Elsevier B.V. All rights reserved.

Continuous motion scan ptychography: Characterization for increased speed in coherent x-ray imaging

DOE PAGES

Deng, Junjing; Nashed, Youssef S. G.; Chen, Si; ...

2015-02-23

Ptychography is a coherent diffraction imaging (CDI) method for extended objects in which diffraction patterns are acquired sequentially from overlapping coherent illumination spots. The object’s complex transmission function can be reconstructed from those diffraction patterns at a spatial resolution limited only by the scattering strength of the object and the detector geometry. Most experiments to date have positioned the illumination spots on the sample using a move-settle-measure sequence in which the move and settle steps can take longer to complete than the measure step. We describe here the use of a continuous “fly-scan” mode for ptychographic data collection in whichmore » the sample is moved continuously, so that the experiment resembles one of integrating the diffraction patterns from multiple probe positions. This allows one to use multiple probe mode reconstruction methods to obtain an image of the object and also of the illumination function. We show in simulations, and in x-ray imaging experiments, some of the characteristics of fly-scan ptychography, including a factor of 25 reduction in the data acquisition time. This approach will become increasingly important as brighter x-ray sources are developed, such as diffraction limited storage rings.« less

Rapid detection and quantification of 2,4-dichlorophenoxyacetic acid in milk using molecularly imprinted polymers-surface-enhanced Raman spectroscopy.

PubMed

Hua, Marti Z; Feng, Shaolong; Wang, Shuo; Lu, Xiaonan

2018-08-30

We report the development of a molecularly imprinted polymers-surface-enhanced Raman spectroscopy (MIPs-SERS) method for rapid detection and quantification of a herbicide residue 2,4-dichlorophenoxyacetic acid (2,4-D) in milk. MIPs were synthesized via bulk polymerization and utilized as solid phase extraction sorbent to selectively extract and enrich 2,4-D from milk. Silver nanoparticles were synthesized to facilitate the collection of SERS spectra of the extracts. Based on the characteristic band intensity of 2,4-D (391 cm -1 ), the limit of detection was 0.006 ppm and the limit of quantification was 0.008 ppm. A simple logarithmic working range (0.01-1 ppm) was established, satisfying the sensitivity requirement referring to the maximum residue level of 2,4-D in milk in both Europe and North America. The overall test of 2,4-D for each milk sample required only 20 min including sample preparation. This MIPs-SERS method has potential for practical applications in detecting 2,4-D in agri-foods. Copyright © 2018 Elsevier Ltd. All rights reserved.

Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging

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

Deng, Junjing; Nashed, Youssef S. G.; Chen, Si

2015-01-01

Ptychography is a coherent diffraction imaging (CDI) method for extended objects in which diffraction patterns are acquired sequentially from overlapping coherent illumination spots. The object's complex transmission function can be reconstructed from those diffraction patterns at a spatial resolution limited only by the scattering strength of the object and the detector geometry. Most experiments to date have positioned the illumination spots on the sample using a move-settle-measure sequence in which the move and settle steps can take longer to complete than the measure step. We describe here the use of a continuous "fly-scan" mode for ptychographic data collection in whichmore » the sample is moved continuously, so that the experiment resembles one of integrating the diffraction patterns from multiple probe positions. This allows one to use multiple probe mode reconstruction methods to obtain an image of the object and also of the illumination function. We show in simulations, and in x-ray imaging experiments, some of the characteristics of fly-scan ptychography, including a factor of 25 reduction in the data acquisition time. This approach will become increasingly important as brighter x-ray sources are developed, such as diffraction limited storage rings.« less

Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging.

PubMed

Deng, Junjing; Nashed, Youssef S G; Chen, Si; Phillips, Nicholas W; Peterka, Tom; Ross, Rob; Vogt, Stefan; Jacobsen, Chris; Vine, David J

2015-03-09

Ptychography is a coherent diffraction imaging (CDI) method for extended objects in which diffraction patterns are acquired sequentially from overlapping coherent illumination spots. The object's complex transmission function can be reconstructed from those diffraction patterns at a spatial resolution limited only by the scattering strength of the object and the detector geometry. Most experiments to date have positioned the illumination spots on the sample using a move-settle-measure sequence in which the move and settle steps can take longer to complete than the measure step. We describe here the use of a continuous "fly-scan" mode for ptychographic data collection in which the sample is moved continuously, so that the experiment resembles one of integrating the diffraction patterns from multiple probe positions. This allows one to use multiple probe mode reconstruction methods to obtain an image of the object and also of the illumination function. We show in simulations, and in x-ray imaging experiments, some of the characteristics of fly-scan ptychography, including a factor of 25 reduction in the data acquisition time. This approach will become increasingly important as brighter x-ray sources are developed, such as diffraction limited storage rings.

Statistical distribution sampling

NASA Technical Reports Server (NTRS)

Johnson, E. S.

1975-01-01

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

Visual endpoint detection of Escherichia coli O157:H7 using isothermal Genome Exponential Amplification Reaction (GEAR) assay and malachite green.

PubMed

Jothikumar, Prithiviraj; Narayanan, Jothikumar; Hill, Vincent R

2014-03-01

Rapid and specific detection methods for bacterial agents in drinking water are important for disease prevention and responding to suspected contamination events. In this study, an isothermal Genome Exponential Amplification Reaction (GEAR) assay for Escherichia coli O157:H7 was designed specifically to recognize a 199-bp fragment of the lipopolysaccharide gene (rfbE) for rapid testing of water samples. The GEAR assay was found to be specific for E. coli O157:H7 using 10 isolates of E. coli O157:H7 and a panel of 86 bacterial controls. The GEAR assay was performed at a constant temperature of 65°C using SYTO 9 intercalating dye. Detection limits were determined to be 20 CFU for the GEAR assay. When SYTO 9 fluorescence was measured using a real-time PCR instrument, the assay had the same detection limit as when malachite green was added to the reaction mix and a characteristic blue color was visually observed in positive reactions. The study also found that 50 and 20 CFU of E. coli O157:H7 seeded into 100-liter of tap water could be detected by the GEAR assays after the sample was concentrated by hollow-fiber ultrafiltration (HFUF) and approximately 10% of HFUF concentrate was cultured using trypticase soy broth-novobiocin. When applied to 19 surface water samples collected from Tennessee and Kentucky, the GEAR assay and a published real-time PCR assay both detected E. coli O157:H7 in two of the samples. The results of this study indicate that the GEAR assay can be sensitive for rapid detection of E. coli O157:H7 in water samples using fluorometric instruments and visual endpoint determination. Published by Elsevier B.V.

Liquid chromatography-electrothermal atomic absorption spectrometry for the separation and preconcentration of molybdenum in milk and infant formulas.

PubMed

López-García, I; Viñas, P; Romero-Romero, R; Hernández-Córdoba, M

2007-08-06

Two procedures for the electrothermal atomic absorption spectrometric determination of molybdenum in milk and infant formulas using slurried samples are described. For powdered milk samples, 10% (m/v) slurries were prepared in a medium containing 25 and 75% (v/v) concentrated hydrogen peroxide and hydrofluoric acid, respectively, and introduced directly into the furnace. Palladium (200 microg mL(-1)) was used as the modifier and calibration was carried out using aqueous standards prepared in the same medium. The detection limit was 0.02 microg g(-1) for powdered milk samples suspended at 10% (m/v) (equivalent to 2 microg L(-1)). The relative standard deviation (R.S.D.) for five measurements was 1.9%, the characteristic mass being 25 pg. For liquid milk samples, a procedure was proposed based on preconcentration and removal of the matrix, using ionic exchange (Amberlite IRA 743) and elution of molybdenum with 5% (m/v) NaOH. In this case, a 30-fold improvement in the calibration slope was achieved, leading to a detection limit of 0.04 microg L(-1) for liquid samples diluted to 10%. The R.S.D. was 3.5%. Using a size-based separation procedure, it was found that molybdenum is present in its inorganic form or associated to low molecular weight substances in cow milk, while in breast milk it is associated to proteins. The reliability of the procedure was checked by comparing the results obtained with those found using a previous mineralization stage and by analyzing three certified reference materials, namely, BCR 063R (skim milk powder), NBS 1549 (non-fat milk powder) and NBS 8435 (whole milk powder).

A group sequential adaptive treatment assignment design for proof of concept and dose selection in headache trials.

PubMed

Hall, David B; Meier, Ulrich; Diener, Hans-Cristoph

2005-06-01

The trial objective was to test whether a new mechanism of action would effectively treat migraine headaches and to select a dose range for further investigation. The motivation for a group sequential, adaptive, placebo-controlled trial design was (1) limited information about where across the range of seven doses to focus attention, (2) a need to limit sample size for a complicated inpatient treatment and (3) a desire to reduce exposure of patients to ineffective treatment. A design based on group sequential and up and down designs was developed and operational characteristics were explored by trial simulation. The primary outcome was headache response at 2 h after treatment. Groups of four treated and two placebo patients were assigned to one dose. Adaptive dose selection was based on response rates of 60% seen with other migraine treatments. If more than 60% of treated patients responded, then the next dose was the next lower dose; otherwise, the dose was increased. A stopping rule of at least five groups at the target dose and at least four groups at that dose with more than 60% response was developed to ensure that a selected dose would be statistically significantly (p=0.05) superior to placebo. Simulations indicated good characteristics in terms of control of type 1 error, sufficient power, modest expected sample size and modest bias in estimation. The trial design is attractive for phase 2 clinical trials when response is acute and simple, ideally binary, placebo comparator is required, and patient accrual is relatively slow allowing for the collection and processing of results as a basis for the adaptive assignment of patients to dose groups. The acute migraine trial based on this design was successful in both proof of concept and dose range selection.

Distinct subcortical volume alterations in pediatric and adult OCD

PubMed Central

Boedhoe, Premika S.W.; Schmaal, Lianne; Abe, Yoshinari; Ameis, Stephanie H.; Arnold, Paul D.; Batistuzzo, Marcelo C.; Benedetti, Francesco; Beucke, Jan C.; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Cheng, Yuqi; Cho, Kang Ik K.; Dallaspezia, Sara; Denys, Damiaan; Fitzgerald, Kate D.; Fouche, Jean-Paul; Giménez, Mònica; Gruner, Patricia; Hanna, Gregory L.; Hibar, Derrek P.; Hoexter, Marcelo Q.; Huyser, Chaim; Ikari, Keisuke; Jahanshad, Neda; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Liu, Yanni; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M.; Minuzzii, Luciano; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C.; Piras, Fabrizio; Piras, Federica; Pittenger, Christopher; Reddy, Y.C. Janardhan; Sato, Joao R.; Simpson, H. Blair; Soreni, Noam; Soriano-Mas, Carles; Spalletta, Gianfranco; Stevens, Michael C.; Szeszko, Philip R.; Tolin, David F.; Venkatasubramanian, Ganesan; Walitza, Susanne; Wang, Zhen; van Wingen, Guido A.; Xu, Jian; Xu, Xiufeng; Yun, Je-Yeon; Zhao, Qing; Thompson, Paul M.; Stein, Dan J.; van den Heuvel, Odile A.

2016-01-01

Objective Structural brain imaging studies in Obsessive-Compulsive Disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in disease profile and developmental stage. Methods To address these limitations, we conducted a meta- and mega-analysis of data from OCD sites worldwide. T1 images from 1,830 OCD patients and 1,759 controls were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ in OCD patients and healthy controls. We additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. Results The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen’s d=−0.13; p=5.1x10−3, % difference −2.80) and larger pallidum volumes (d=0.16; p=1.6x10−3, % difference 3.16) compared to adult controls. Both effects were stronger in medicated patients compared to controls (d=−0.29; p=2.4x10−5, % difference −4.18 and d=0.29; p=1.2x10−5, % difference 4.38, respectively). Unmedicated pediatric patients had larger thalamic volumes (d=0.38, p=2.1x10−3) compared to pediatric controls. None of these findings were mediated by sample characteristics such as mean age or field strength. Overall the mega-analysis yielded similar results. Conclusion Our study indicates a different pattern of subcortical abnormalities in pediatric versus adult OCD patients. The pallidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. This highlights the potential importance of neurodevelopmental alterations in OCD, and suggests that further research on neuroplasticity in OCD may be useful. PMID:27609241

Distinct Subcortical Volume Alterations in Pediatric and Adult OCD: A Worldwide Meta- and Mega-Analysis.

PubMed

Boedhoe, Premika S W; Schmaal, Lianne; Abe, Yoshinari; Ameis, Stephanie H; Arnold, Paul D; Batistuzzo, Marcelo C; Benedetti, Francesco; Beucke, Jan C; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Cheng, Yuqi; Cho, Kang Ik K; Dallaspezia, Sara; Denys, Damiaan; Fitzgerald, Kate D; Fouche, Jean-Paul; Giménez, Mònica; Gruner, Patricia; Hanna, Gregory L; Hibar, Derrek P; Hoexter, Marcelo Q; Hu, Hao; Huyser, Chaim; Ikari, Keisuke; Jahanshad, Neda; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Liu, Yanni; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M; Minuzzi, Luciano; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C; Piras, Fabrizio; Piras, Federica; Pittenger, Christopher; Reddy, Y C Janardhan; Sato, Joao R; Simpson, H Blair; Soreni, Noam; Soriano-Mas, Carles; Spalletta, Gianfranco; Stevens, Michael C; Szeszko, Philip R; Tolin, David F; Venkatasubramanian, Ganesan; Walitza, Susanne; Wang, Zhen; van Wingen, Guido A; Xu, Jian; Xu, Xiufeng; Yun, Je-Yeon; Zhao, Qing; Thompson, Paul M; Stein, Dan J; van den Heuvel, Odile A

2017-01-01

Structural brain imaging studies in obsessive-compulsive disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in illness profile and developmental stage. To address these limitations, the authors conducted meta- and mega-analyses of data from OCD sites worldwide. T 1 images from 1,830 OCD patients and 1,759 control subjects were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ between OCD patients and healthy subjects. The authors performed a meta-analysis on the mean of the left and right hemisphere measures of each subcortical structure, and they performed a mega-analysis by pooling these volumetric measurements from each site. The authors additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen's d=-0.13; % difference=-2.80) and larger pallidum volumes (d=0.16; % difference=3.16) compared with adult controls. Both effects were stronger in medicated patients compared with controls (d=-0.29, % difference=-4.18, and d=0.29, % difference=4.38, respectively). Unmedicated pediatric patients had significantly larger thalamic volumes (d=0.38, % difference=3.08) compared with pediatric controls. None of these findings were mediated by sample characteristics, such as mean age or scanning field strength. The mega-analysis yielded similar results. The results indicate different patterns of subcortical abnormalities in pediatric and adult OCD patients. The pallidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. These findings highlight the potential importance of neurodevelopmental alterations in OCD and suggest that further research on neuroplasticity in OCD may be useful.

Indoor concentrations of nicotine in low-income, multi-unit housing: associations with smoking behaviours and housing characteristics

PubMed Central

Kraev, TA; Adamkiewicz, G; Hammond, SK; Spengler, JD

2017-01-01

Objective An analysis of airborne nicotine measurements collected in 49 low-income, multi-unit residences across the Greater Boston Area. Methods Nicotine concentrations were determined using passive monitors placed in homes over a one-week sampling period and air exchange rates (AER) were sampled using the perfluorocarbon tracer technique. Residents were surveyed through a questionnaire about smoking behaviour and a visual inspection was conducted to collect information on housing characteristics contributing to secondhand smoke (SHS) exposure. Using a mass balance model to account for the air exchange rate, volume of the home and sorption and re-emission of nicotine on indoor surfaces, the effective smoking rate (SReff) was determined for each residence. Results Nicotine levels ranged from the limit of detection to 26.92 µg/m3, with a mean of 2.20 µg/m3 and median of 0.13 µg/m3. Nicotine measurements were significantly associated with the number of smokers in the household and the number of cigarettes smoked in the home. The results of this study suggest that questionnaire reports can provide a valid estimate of residential exposure to tobacco smoke. In addition, this study found evidence that tobacco smoke contamination in low-income housing developments is not limited to homes with smokers (either residing in the home or visiting). The frequent report of tobacco smoke odour coming from other apartments or hallways resulted in increased levels of nicotine concentrations and SReff in non-smoking homes, suggestive of SHS infiltration from neighbouring units. Conclusion These findings have important implications for smoking regulations in multi-unit homes and highlight the need to reduce involuntary exposure to tobacco smoke among low-income housing residents. PMID:19679890

Indoor concentrations of nicotine in low-income, multi-unit housing: associations with smoking behaviours and housing characteristics.

PubMed

Kraev, T A; Adamkiewicz, G; Hammond, S K; Spengler, J D

2009-12-01

An analysis of airborne nicotine measurements collected in 49 low-income, multi-unit residences across the Greater Boston Area. Nicotine concentrations were determined using passive monitors placed in homes over a one-week sampling period and air exchange rates (AER) were sampled using the perfluorocarbon tracer technique. Residents were surveyed through a questionnaire about smoking behaviour and a visual inspection was conducted to collect information on housing characteristics contributing to secondhand smoke (SHS) exposure. Using a mass balance model to account for the air exchange rate, volume of the home and sorption and re-emission of nicotine on indoor surfaces, the effective smoking rate (SR(eff)) was determined for each residence. Nicotine levels ranged from the limit of detection to 26.92 microg/m(3), with a mean of 2.20 microg/m(3) and median of 0.13 microg/m(3). Nicotine measurements were significantly associated with the number of smokers in the household and the number of cigarettes smoked in the home. The results of this study suggest that questionnaire reports can provide a valid estimate of residential exposure to tobacco smoke. In addition, this study found evidence that tobacco smoke contamination in low-income housing developments is not limited to homes with smokers (either residing in the home or visiting). The frequent report of tobacco smoke odour coming from other apartments or hallways resulted in increased levels of nicotine concentrations and SR(eff) in non-smoking homes, suggestive of SHS infiltration from neighbouring units. These findings have important implications for smoking regulations in multi-unit homes and highlight the need to reduce involuntary exposure to tobacco smoke among low-income housing residents.

Advanced lung adenocarcinomas with ROS1-rearrangement frequently show hepatoid cell

PubMed Central

Kong, Mei; Zhou, Jianya; Ding, Wei; Zhou, Jianying

2016-01-01

Defining distinctive histologic characteristics of ROS1-rearranged non-small-cell lung carcinomas (NSCLCs) may help identify cases that merit molecular testing. However, the majority of previous reports have focused on surgical specimens but only limited studies assessed histomorphology of advanced NSCLCs. In order to identify the clinical and histological characteristics of ROS1-rearranged advanced NSCLCs, we examined five hundred sixteen Chinese patients with advanced NSCLCs using ROS1 fluorescence in situ hybridization and real-time polymerase chain reaction and then analyzed for clinical and pathological features. We performed univariate and multivariate analyses to identify predictive factors associated with ROS1 rearrangement. 19 tumors were identified with ROS1 rearrangement (3.7% of adenocarcinomas). 16 ROS1+ and 122 ROS1- samples with available medical records and enough tumor cells were included for histological analysis. Compared with ROS1-negative advanced NSCLCs, ROS1-rearranged advanced NSCLCs were associated with a younger age at presentation. ROS1 rearrangements were not significantly associated with sex, smoking history, drinking history and metastatic sites. The most common histological pattern was solid growth (12/16), followed by acinar (4/16) growth. 66.7% cases with solid growth pattern showed hepatoid cytology (8/12) and 75% cases with acinar growth pattern showed a cribriform structure (3/4). 18.8% cases were found to have abundant extracellular mucus or signet-ring cells (3/16). Only one case with solid growth pattern showed psammomatous calcifications. In conclusion, age, hepatoid cytology and cribriform structure are the independent predictors for ROS1-rearranged advanced NSCLCs, recognizing these may be helpful in finding candidates for genomic alterations, especially when available tissue samples are limited. PMID:27708233

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

Assessing streamflow characteristics as limiting factors on benthic invertebrate assemblages in streams across the western United States

USGS Publications Warehouse

Konrad, C.P.; Brasher, A.M.D.; May, J.T.

2008-01-01

4. Relative abundance of Plecoptera, richness of non-insect taxa and relative abundance of intolerant taxa were associated with multiple streamflow metrics. Metrics of sensitive taxa (Ephemeroptera, Plecoptera and Trichoptera), and intolerant taxa generally had ceilings associated with flow metrics while metrics of tolerant taxa, non-insects, dominance and chironomids generally had floors. Broader characteristics of invertebrate assemblages such as abundance and richness had fewer limits, but these limits were nonetheless associated with a broad range of streamflow characteristics.

On Shaft Data Acquisition System (OSDAS)

NASA Technical Reports Server (NTRS)

Pedings, Marc; DeHart, Shawn; Formby, Jason; Naumann, Charles

2012-01-01

On Shaft Data Acquisition System (OSDAS) is a rugged, compact, multiple-channel data acquisition computer system that is designed to record data from instrumentation while operating under extreme rotational centrifugal or gravitational acceleration forces. This system, which was developed for the Heritage Fuel Air Turbine Test (HFATT) program, addresses the problem of recording multiple channels of high-sample-rate data on most any rotating test article by mounting the entire acquisition computer onboard with the turbine test article. With the limited availability of slip ring wires for power and communication, OSDAS utilizes its own resources to provide independent power and amplification for each instrument. Since OSDAS utilizes standard PC technology as well as shared code interfaces with the next-generation, real-time health monitoring system (SPARTAA Scalable Parallel Architecture for Real Time Analysis and Acquisition), this system could be expanded beyond its current capabilities, such as providing advanced health monitoring capabilities for the test article. High-conductor-count slip rings are expensive to purchase and maintain, yet only provide a limited number of conductors for routing instrumentation off the article and to a stationary data acquisition system. In addition to being limited to a small number of instruments, slip rings are prone to wear quickly, and introduce noise and other undesirable characteristics to the signal data. This led to the development of a system capable of recording high-density instrumentation, at high sample rates, on the test article itself, all while under extreme rotational stress. OSDAS is a fully functional PC-based system with 48 channels of 24-bit, high-sample-rate input channels, phase synchronized, with an onboard storage capacity of over 1/2-terabyte of solid-state storage. This recording system takes a novel approach to the problem of recording multiple channels of instrumentation, integrated with the test article itself, packaged in a compact/rugged form factor, consuming limited power, all while rotating at high turbine speeds.

Development and analytical validation of an enzyme linked immunosorbent assay for the measurement of canine gastric lipase immunoreactivity in serum

PubMed Central

2004-01-01

Abstract The objective of this study was to develop and analytically validate an enzyme linked immunosorbent assay (ELISA) for measurement of canine gastric lipase immunoreactivity (cGLI). A sandwich ELISA was developed using canine gastric lipase (cGL) purified from canine stomachs and polyclonal antibodies directed against cGL, raised in rabbits and purified by affinity chromatography. The assay was validated by determination of sensitivity, working range, linearity, accuracy, precision, reproducibility, and the upper limit of the control range by determining the 97.5th percentile of serum cGLI concentration in 74 healthy canines. Sensitivity and working range in serum were 200 ng/L and 200 to 39 160 ng/L, respectively. Observed to expected ratios for dilutional parallelism for 3 serum samples and 3 dilutions ranged from 86.1% to 244.2% (mean ± standard deviation [s]; 125.4% ± 48.2%). Observed to expected ratios for spiking recoveries for 3 serum samples and 6 spiking concentrations ranged from 66.4% to 152.5% (mean ± s; 104.5% ± 22.9%). Intra-assay and interassay variabilities for 3 different serum samples were 25.5%, 9.4%, and 13.4% and 26.0%, 17.2%, and 14.4%, respectively. The upper limit of the control range for serum cGLI was 662 ng/L. We concluded that the ELISA for cGLI described here is highly sensitive and shows a wide working range. However, the validation characteristics for this assay are suboptimal and below values of approximately 2.000 ng/L the assay is more semiquantitative in nature. Despite its limitations, whether this assay is useful for the diagnosis of canine gastric disorders remains to be determined. PMID:15352539

Solid phase extraction with high polarity Carb/PSA as composite fillers prior to UPLC-MS/MS to determine six bisphenols and alkylphenols in trace level hotpot seasoning.

PubMed

Dong, Hao; Zeng, Xiaofang; Bai, Weidong

2018-08-30

The present study reports an ultra high-performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of six bisphenols (bisphenol A, bisphenol B and bisphenol F) and alkylphenols (4-nonylphenol, 4-n-nonylphenol and octylphenol) in hotpot seasoning. Samples were dispersed in n-hexane after addition of internal standards bisphenol A-d 4 and 4-n-nonylphenol-d 4 . Sample solutions were then centrifuged, and the supernatants purified using solid phase extraction with high polarity Carb/PSA composite fillers. Six target analytes were separated on a Waters ACQUITY BEH C18 column by gradient elution with methanol and 0.05% ammonium hydroxide in water as the mobile phase, and determined under multiple reactions monitoring mode. The limits of detection and quantitation, matrix effect, recovery and precision of the method were investigated. Results were linear in the concentration range 0.1-250 µg/L for all compounds of interest, with R 2  > 0.9950. Limits of detection were in the range 0.1-0.4 μg/kg, and limits of quantitation were between 0.5 μg/kg and 1.0 μg/kg. The mean recoveries for negative samples at three spiked concentrations were in the range 87.9%-102.4%, and the intra-day precision and inter-day precision were in the ranges 2.1-8.2% and 4.8-11.2%, respectively. This method is accurate and sensitive, and had good clean-up characteristics, which might apply to screening and quantitation of target bisphenols and alkylphenols in hotpot seasoning. Copyright © 2018 Elsevier Ltd. All rights reserved.

PubMed Central

King-Shier, Kathryn M; Hemmelgarn, Brenda R; Musto, Richard; Quan, Hude

2014-01-01

Background: Francophones who live outside the primarily French-speaking province of Quebec, Canada, risk being excluded from research by lack of a sampling frame. We examined the adequacy of random sampling, advertising, and respondent-driven sampling for recruitment of francophones for survey research. Methods: We recruited francophones residing in the city of Calgary, Alberta, through advertising and respondentdriven sampling. These 2 samples were then compared with a random subsample of Calgary francophones derived from the 2006 Canadian Community Health Survey (CCHS). We assessed the effectiveness of advertising and respondent-driven sampling in relation to the CCHS sample by comparing demographic characteristics and selected items from the CCHS (specifically self-reported general health status, perceived weight, and having a family doctor). Results: We recruited 120 francophones through advertising and 145 through respondent-driven sampling; the random sample from the CCHS consisted of 259 records. The samples derived from advertising and respondentdriven sampling differed from the CCHS in terms of age (mean ages 41.0, 37.6, and 42.5 years, respectively), sex (proportion of males 26.1%, 40.6%, and 56.6%, respectively), education (college or higher 86.7% , 77.9% , and 59.1%, respectively), place of birth (immigrants accounting for 45.8%, 55.2%, and 3.7%, respectively), and not having a regular medical doctor (16.7%, 34.5%, and 16.6%, respectively). Differences were not tested statistically because of limitations on the analysis of CCHS data imposed by Statistics Canada. Interpretation: The samples generated exclusively through advertising and respondent-driven sampling were not representative of the gold standard sample from the CCHS. Use of such biased samples for research studies could generate misleading results. PMID:25426180

Effect of finite sample size on feature selection and classification: a simulation study.

PubMed

Way, Ted W; Sahiner, Berkman; Hadjiiski, Lubomir M; Chan, Heang-Ping

2010-02-01

The small number of samples available for training and testing is often the limiting factor in finding the most effective features and designing an optimal computer-aided diagnosis (CAD) system. Training on a limited set of samples introduces bias and variance in the performance of a CAD system relative to that trained with an infinite sample size. In this work, the authors conducted a simulation study to evaluate the performances of various combinations of classifiers and feature selection techniques and their dependence on the class distribution, dimensionality, and the training sample size. The understanding of these relationships will facilitate development of effective CAD systems under the constraint of limited available samples. Three feature selection techniques, the stepwise feature selection (SFS), sequential floating forward search (SFFS), and principal component analysis (PCA), and two commonly used classifiers, Fisher's linear discriminant analysis (LDA) and support vector machine (SVM), were investigated. Samples were drawn from multidimensional feature spaces of multivariate Gaussian distributions with equal or unequal covariance matrices and unequal means, and with equal covariance matrices and unequal means estimated from a clinical data set. Classifier performance was quantified by the area under the receiver operating characteristic curve Az. The mean Az values obtained by resubstitution and hold-out methods were evaluated for training sample sizes ranging from 15 to 100 per class. The number of simulated features available for selection was chosen to be 50, 100, and 200. It was found that the relative performance of the different combinations of classifier and feature selection method depends on the feature space distributions, the dimensionality, and the available training sample sizes. The LDA and SVM with radial kernel performed similarly for most of the conditions evaluated in this study, although the SVM classifier showed a slightly higher hold-out performance than LDA for some conditions and vice versa for other conditions. PCA was comparable to or better than SFS and SFFS for LDA at small samples sizes, but inferior for SVM with polynomial kernel. For the class distributions simulated from clinical data, PCA did not show advantages over the other two feature selection methods. Under this condition, the SVM with radial kernel performed better than the LDA when few training samples were available, while LDA performed better when a large number of training samples were available. None of the investigated feature selection-classifier combinations provided consistently superior performance under the studied conditions for different sample sizes and feature space distributions. In general, the SFFS method was comparable to the SFS method while PCA may have an advantage for Gaussian feature spaces with unequal covariance matrices. The performance of the SVM with radial kernel was better than, or comparable to, that of the SVM with polynomial kernel under most conditions studied.

Method of remotely characterizing thermal properties of a sample

NASA Technical Reports Server (NTRS)

Heyman, Joseph S. (Inventor); Heath, D. Michele (Inventor); Welch, Christopher (Inventor); Winfree, William P. (Inventor); Miller, William E. (Inventor)

1992-01-01

A sample in a wind tunnel is radiated from a thermal energy source outside of the wind tunnel. A thermal imager system, also located outside of the wind tunnel, reads surface radiations from the sample as a function of time. The produced thermal images are characteristic of the heat transferred from the sample to the flow across the sample. In turn, the measured rates of heat loss of the sample are characteristic of the flow and the sample.

Investigation of chemical modifiers for the direct determination of arsenic in fish oil using high-resolution continuum source graphite furnace atomic absorption spectrometry.

PubMed

Pereira, Éderson R; de Almeida, Tarcísio S; Borges, Daniel L G; Carasek, Eduardo; Welz, Bernhard; Feldmann, Jörg; Campo Menoyo, Javier Del

2016-04-01

High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) has been applied for the development of a method for the determination of total As in fish oil samples using direct analysis. The method does not use any sample pretreatment, besides dilution with 1-propanole, in order to decrease the oil viscosity. The stability and sensitivity of As were evaluated using ruthenium and iridium as permanent chemical modifiers and palladium added in solution over the sample. The best results were obtained with ruthenium as the permanent modifier and palladium in solution added to samples and standard solutions. Under these conditions, aqueous standard solutions could be used for calibration for the fish oil samples diluted with 1-propanole. The pyrolysis and atomization temperatures were 1400 °C and 2300 °C, respectively, and the limit of detection and characteristic mass were 30 pg and 43 pg, respectively. Accuracy and precision of the method have been evaluated using microwave-assisted acid digestion of the samples with subsequent determination by HR-CS GF AAS and ICP-MS; the results were in agreement (95% confidence level) with those of the proposed method. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of combination tapered fiber-optic biosensor dip probe for quantitative estimation of interleukin-6 in serum samples

NASA Astrophysics Data System (ADS)

Wang, Chun Wei; Manne, Upender; Reddy, Vishnu B.; Oelschlager, Denise K.; Katkoori, Venkat R.; Grizzle, William E.; Kapoor, Rakesh

2010-11-01

A combination tapered fiber-optic biosensor (CTFOB) dip probe for rapid and cost-effective quantification of proteins in serum samples has been developed. This device relies on diode laser excitation and a charged-coupled device spectrometer and functions on a technique of sandwich immunoassay. As a proof of principle, this technique was applied in a quantitative estimation of interleukin IL-6. The probes detected IL-6 at picomolar levels in serum samples obtained from a patient with lupus, an autoimmune disease, and a patient with lymphoma. The estimated concentration of IL-6 in the lupus sample was 5.9 +/- 0.6 pM, and in the lymphoma sample, it was below the detection limit. These concentrations were verified by a procedure involving bead-based xMAP technology. A similar trend in the concentrations was observed. The specificity of the CTFOB dip probes was assessed by analysis with receiver operating characteristics. This analysis suggests that the dip probes can detect 5-pM or higher concentration of IL-6 in these samples with specificities of 100%. The results provide information for guiding further studies in the utilization of these probes to quantify other analytes in body fluids with high specificity and sensitivity.

The credibility of speed limits on 80 km/h rural roads: The effects of road and person(ality) characteristics.

PubMed

Goldenbeld, Charles; van Schagen, Ingrid

2007-11-01

The present study aimed to operationalise the concept of credible speed limits and to make a first step to elaborate it in such a way that road authorities can put the concept into practice. The study focused on the credibility of an 80 km/h limit for different rural roads and assessed the effects of characteristics of the road and its environment as well as the effects of person and personality characteristics. Almost 600 Dutch car drivers were asked to judge 27 photographs of (different) rural roads with a posted speed limit of 80 km/h. To determine the degree of credibility, for each road scene the subjects filled in the preferred speed and the speed limit they considered to be safe. The results show large differences in both preferred speed and the safe speed limit between the road scenes, both below and above the limit of 80 km/h. These differences were related to a number of characteristics of the road and the road environment, such as the presence or absence of a curve and characteristics concerning the field of view (sight distance, clarity of situation). There were also large differences between subjects and these were related to age, the degree of sensation seeking, the number of speeding tickets in the last 3 years and the part of the country they lived in. Subjects were influenced by more or less the same road features.

Direct determination of chromium in infant formulas employing high-resolution continuum source electrothermal atomic absorption spectrometry and solid sample analysis.

PubMed

Silva, Arlene S; Brandao, Geovani C; Matos, Geraldo D; Ferreira, Sergio L C

2015-11-01

The present work proposed an analytical method for the direct determination of chromium in infant formulas employing the high-resolution continuum source electrothermal atomic absorption spectrometry combined with the solid sample analysis (SS-HR-CS ET AAS). Sample masses up to 2.0mg were directly weighted on a solid sampling platform and introduced into the graphite tube. In order to minimize the formation of carbonaceous residues and to improve the contact of the modifier solution with the solid sample, a volume of 10 µL of a solution containing 6% (v/v) H2O2, 20% (v/v) ethanol and 1% (v/v) HNO3 was added. The pyrolysis and atomization temperatures established were 1600 and 2400 °C, respectively, using magnesium as chemical modifier. The calibration technique was evaluated by comparing the slopes of calibration curves established using aqueous and solid standards. This test revealed that chromium can be determined employing the external calibration technique using aqueous standards. Under these conditions, the method developed allows the direct determination of chromium with limit of quantification of 11.5 ng g(-1), precision expressed as relative standard deviation (RSD) in the range of 4.0-17.9% (n=3) and a characteristic mass of 1.2 pg of chromium. The accuracy was confirmed by analysis of a certified reference material of tomato leaves furnished by National Institute of Standards and Technology. The method proposed was applied for the determination of chromium in five different infant formula samples. The chromium content found varied in the range of 33.9-58.1 ng g(-1) (n=3). These samples were also analyzed employing ICP-MS. A statistical test demonstrated that there is no significant difference between the results found by two methods. The chromium concentrations achieved are lower than the maximum limit permissible for chromium in foods by Brazilian Legislation. Copyright © 2015. Published by Elsevier B.V.

How do subcritical cracking rates and styles influence rock erosion? A test case from the Blue Ridge Mountains of Virginia.

NASA Astrophysics Data System (ADS)

Eppes, M. C.; Hancock, G. S.; Dewers, T. A.; Chen, X.; Eichhubl, P.

2017-12-01

There is a disconnect between measured rates of rock erosion and regolith production and our understanding of the factors and processes that drive them. Here we examine the mechanical weathering (cracking) characteristics of natural, bare bedrock outcrops characterized by 10Be derived erosion rates that vary from 2 to 40 m/my in the Blue Ridge Mountains, VA. Observed erosion rate variance generally correlates with rock type; we seek to characterize and quantify to what extent the mechanical weathering properties of the different rock types drive erosion rates. We assert that subcritical cracking constitutes the primary mechanism by which the outcrops increase their porosity and subsequently weather and erode. We therefore hypothesize that rock parameters that control rates and styles of subcritical cracking set the outcrop erosion rates. For each outcrop, we measured crack characteristics along transects: for every crack >2 cm length, we measured its length, width, orientation, and weathering characteristics (rounded vs sharp edges); and we measured the thickness of all `steps' (spallation remnants) encountered in the transects. For most outcrops, we collected surface samples in order to characterize their mineralogy and microcracking characteristics through thin section analysis. For each rock type, we collected samples for which we measured fracture toughness, as well as the subcritical crack growth index under different moisture conditions. Preliminary analysis of the field crack data indicates that each rock type (granite, sandstone, quartzite) is characterized by unique macro- and micro-scale crack characteristics consistent with known generic subcritical cracking parameters for those rocks. Crack density and length correlate with erosion rates in faster eroding rock types, but not slowly eroding ones. Overall, we hope these data will help to shed light on the driving and limiting factors for the mechanical production of porosity in rock at and near Earth's surface.

Associations between skin barrier characteristics, skin conditions and health of aged nursing home residents: a multi-center prevalence and correlational study.

PubMed

Hahnel, Elisabeth; Blume-Peytavi, Ulrike; Trojahn, Carina; Kottner, Jan

2017-11-13

Geriatric patients are affected by a range of skin conditions and dermatological diseases, functional limitations and chronic diseases. Skin problems are highly prevalent in elderly populations. Aim of this study was to investigate possible associations between health, functional and cutaneous variables in aged long-term care residents. This observational, cross-sectional, descriptive prevalence study was conducted in a random sample of 10 institutional long-term care facilities in Berlin. In total, n = 223 residents were included. Demographic and functional characteristics, xerosis cutis, incontinence associated dermatitis, pressure ulcers and skin tears were assessed. Stratum corneum hydration, transepidermal water loss, skin surface pH and skin temperature were measured. Data analysis was descriptive and explorative. To explore possible bivariate associations, a correlation matrix was created. The correlation matrix was also used to detect possible collinearity in the subsequent regression analyses. Mean age (n = 223) was 83.6 years, 67.7% were female. Most residents were affected by xerosis cutis (99.1%; 95% CI: 97.7% - 100.0%). The prevalence of pressure ulcers was 9.0% (95% CI: 5.0% - 13.0%), of incontinence associated dermatitis 35.4% (95% CI: 29.9% - 42.2%) and of skin tears 6.3% (95% CI: 3.2% - 9.5%). Biophysical skin parameters were not associated with overall care dependency, but with age and skin dryness. In general, skin dryness and measured skin barrier parameters were associated between arms and legs indicating similar overall skin characteristics of the residents. Prevalence of xerosis cutis, pressure ulcers and skin tears were high, indicating the load of these adverse skin conditions in this population. Only few associations of demographic characteristics, skin barrier impairments and the occurrence of dry skin, pressure ulcers, skin tears and incontinence-associated dermatitis have been detected, that might limit the diagnostic value of skin barrier parameters in this population. Overall, the measured skin barrier parameters seem to have limited diagnostic value for the reported skin conditions except xerosis cutis. This study is registered at https://clinicaltrials.gov/ct2/show/NCT02216526 . Registration date: 8th November 2014.

FAST TRACK COMMUNICATION Generation of stable multi-jets by flow-limited field-injection electrostatic spraying and their control via I-V characteristics

NASA Astrophysics Data System (ADS)

Gu, W.; Heil, P. E.; Choi, H.; Kim, K.

2010-12-01

The I-V characteristics of flow-limited field-injection electrostatic spraying (FFESS) were investigated, exposing a new way to predict and control the specific spraying modes from single-jet to multi-jet. Monitoring the I-V characteristics revealed characteristic drops in the current upon formation of an additional jet in the multi-jet spraying mode. For fixed jet numbers, space-charge-limited current behaviour was measured which was attributed to space charge in the dielectric liquids between the needle electrode and the nozzle opening. The present work establishes that FFESS can, in particular, generate stable multiple jets and that their control is possible through monitoring the I-V characteristics. This can allow for automatic control of the FFESS process and expedite its future scientific and industrial applications.

ST product characteristics and relationships with perceptions and behaviors among rural adolescent males: a qualitative study.

PubMed

Couch, Elizabeth T; Darius, Ellen F; Walsh, Margaret M; Chaffee, Benjamin W

2017-12-01

Although smoking declines in the United States, the prevalence of male adolescent smokeless tobacco (ST; moist snuff and chewing tobacco) use remains unchanged. ST product characteristics, such as flavoring, packaging, and branding, could influence adolescents' ST initiation and continued use. This qualitative study examines the potential role of product characteristics in shaping ST-related perceptions and behaviors among rural adolescent males. Semi-structured individual interviews were conducted at three California rural high schools. ST users were asked about their experiences and perceptions related to product characteristics. Interviews were transcribed, coded, and analyzed using a general inductive approach. Participants associated flavored ST with appealing non-tobacco products, such as chewing gum and alcohol. Availability of different varieties and flavors stimulated interest and curiosity in sampling or switching between ST products. Time-limited promotional flavors and packaging also enhanced product appeal. Adolescent ST users preferred certain brands based on perceived brand features and perceived nicotine content, associating higher-strength brands as better suited for experienced ST users. Brand preferences frequently reflected perceived ST brand popularity within peer groups. Based on these observations, potential ST regulation and health education campaigns to address misconceptions about ST characteristics could influence adolescents' ST-related perceptions and reduce ST use among this vulnerable population. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

ERP differences between processing of physical characteristics and personality attributes

PubMed Central

2012-01-01

Background Limited data from behavioral and brain-imaging studies indicate that personality traits and physical characteristics are processed differently by the brain. Additionally, electrophysiological results of studies comparing the processing of positive and negative words have produced mixed results. It is therefore not clear how physical and personality attributes with emotional valence (i.e., positive and negative valence) are processed. Thus, this study aimed to examine the neural activity associated with words describing personality traits and physical characteristics with positive or negative emotional valence using Event Related Potentials (ERPs). Methods A sample of 15 healthy adults (7 men, 8 women) participated in a computerized word categorization task. Participants were asked to categorize visual word stimuli as physical characteristics or personality traits, while ERPs were recorded synchronously. Results Behavioral reaction times to negative physical stimuli were shorter compared to negative personality words, however reaction times did not significantly differ for positive stimuli. Electrophysiological results showed that personality stimuli elicited larger P2 and LPC (Late Positive Component) amplitudes compared to physical stimuli, regardless of negative or positive valence. Moreover, negative as compared with positive stimuli elicited larger P2 and LPC amplitudes. Conclusion Personality and physical stimuli were processed differently regardless of positive or negative valence. These findings suggest that personality traits and physical characteristics are differentially classified and are associated with different motivational significance. PMID:22967478

Solidification and stabilization of the incinerated wastewater sludge from textile industry

NASA Astrophysics Data System (ADS)

Aziz, Hamidi Abdul; Ghazali, Miskiah Fadzilah; Omran, Abdelnaser; Umar, Muhammad

2017-10-01

This paper describes the investigation of solidification and stabilization (S/S) process for the safe disposal of incinerated wastewater sludge produced from a textile industry in Penang, Malaysia. Physical and chemical properties of the samples were first characterized. Various ratios of ordinary Portland cement (OPC) as a binder were used to immobilize the metals. The leachability of metals in these cement-based waste materials was studied by standard toxicity characteristic leaching procedure (TCLP) and the mechanical strength was tested by a compressive strength test. TCLP results showed the ability of OPC to immobilize various metals such as Zn, Cu, Fe, Al, Ti, and K within the limits set by USEPA and Malaysia Environment Quality Act, 1974. However, the strength of the solidified matrixes was generally lower than the control specimens, ranging from 1-23 Mpa, which was well above the specified limit of 414 kPa for such matrices for their disposal in landfills.

Bayesian Regression with Network Prior: Optimal Bayesian Filtering Perspective

PubMed Central

Qian, Xiaoning; Dougherty, Edward R.

2017-01-01

The recently introduced intrinsically Bayesian robust filter (IBRF) provides fully optimal filtering relative to a prior distribution over an uncertainty class ofjoint random process models, whereas formerly the theory was limited to model-constrained Bayesian robust filters, for which optimization was limited to the filters that are optimal for models in the uncertainty class. This paper extends the IBRF theory to the situation where there are both a prior on the uncertainty class and sample data. The result is optimal Bayesian filtering (OBF), where optimality is relative to the posterior distribution derived from the prior and the data. The IBRF theories for effective characteristics and canonical expansions extend to the OBF setting. A salient focus of the present work is to demonstrate the advantages of Bayesian regression within the OBF setting over the classical Bayesian approach in the context otlinear Gaussian models. PMID:28824268

Validation of Ion Chromatographic Method for Determination of Standard Inorganic Anions in Treated and Untreated Drinking Water

NASA Astrophysics Data System (ADS)

Ivanova, V.; Surleva, A.; Koleva, B.

2018-06-01

An ion chromatographic method for determination of fluoride, chloride, nitrate and sulphate in untreated and treated drinking waters was described. An automated 850 IC Professional, Metrohm system equipped with conductivity detector and Metrosep A Supp 7-250 (250 x 4 mm) column was used. The validation of the method was performed for simultaneous determination of all studied analytes and the results have showed that the validated method fits the requirements of the current water legislation. The main analytical characteristics were estimated for each of studied analytes: limits of detection, limits of quantification, working and linear ranges, repeatability and intermediate precision, recovery. The trueness of the method was estimated by analysis of certified reference material for soft drinking water. Recovery test was performed on spiked drinking water samples. An uncertainty was estimated. The method was applied for analysis of drinking waters before and after chlorination.

Quality of life after percutaneous coronary intervention: part 1.

PubMed

Cassar, Stephen; R Baldacchino, Donia

Quality of life (QOL) is a complex concept comprised of biopsychosocial, spiritual and environmental dimensions. However, the majority of research addresses only its physical function perspectives. This two-part series examines the holistic perspective of QOL of patients after percutaneous coronary intervention (PCI). Part 1 explains the research process of a cross-sectional descriptive study and its limitations. Data were collected by a mailed WHOQOL-BREF questionnaire in Maltese from a systematic sample of patients who had undergone PCI; the response rate was 64% (n=228; males n=169, females n=59, age 40-89 years). Part 1 also considers limitations, such as its cross-sectional design and retrospective data collection. The hierarchy of human needs theory (Maslow, 1999) guided the study. Part 2 gives the findings on the holistic view of QOL. Having social and family support, as a characteristic of Maltese culture appeared to contribute towards a better QOL.

Single excitation-emission fluorescence spectrum (EEF) for determination of cetane improver in diesel fuel.

PubMed

Insausti, Matías; Fernández Band, Beatriz S

2015-04-05

A highly sensitive spectrofluorimetric method has been developed for the determination of 2-ethylhexyl nitrate in diesel fuel. Usually, this compound is used as an additive in order to improve cetane number. The analytical method consists in building the chemometric model as a first step. Then, it is possible to quantify the analyte with only recording a single excitation-emission fluorescence spectrum (EEF), whose data are introduced in the chemometric model above mentioned. Another important characteristic of this method is that the fuel sample was used without any pre-treatment for EEF. This work provides an interest improvement to fluorescence techniques using the rapid and easily applicable EEF approach to analyze such complex matrices. Exploding EEF was the key to a successful determination, obtaining a detection limit of 0.00434% (v/v) and a limit of quantification of 0.01446% (v/v). Copyright © 2015 Elsevier B.V. All rights reserved.

Radiation accident dosimetry on plastics by EPR spectrometry.

PubMed

Trompier, F; Bassinet, C; Clairand, I

2010-02-01

In case of acute exposure to ionizing radiation, the dose absorbed by the victims has to be rapidly and accurately assessed in order to choose an appropriate medical treatment. Tooth enamel and bone biopsies measured by EPR spectrometry are often used as dose indicators, due to the good radiation sensitivity and the stability of EPR radiation-sensitive signals. Nevertheless, the invasive sampling of teeth and bones limits the application of this technique to retrospective dosimetry. Therefore, we have investigated an alternative non-invasive methodology. We have surveyed with EPR spectrometry the dosimetric properties of the plastics that can be found in personal effects such as glasses (CR-39, polycarbonate), mobile phones (PMMA, polycarbonate), watches and buttons. Dose response, signal stability and effects of storage conditions were investigated. Significant signal fading limits the use for radiation accident dosimetry. Few plastics present the required characteristics to be used in case of a radiation accident.

Application of ICP-OES for evaluating energy extraction and production wastewater discharge impacts on surface waters in Western Pennsylvania.

PubMed

Pancras, Joseph Patrick; Norris, Gary A; Landis, Matthew S; Kovalcik, Kasey D; McGee, John K; Kamal, Ali S

2015-10-01

Oil and gas extraction and coal-fired electrical power generating stations produce wastewaters that are treated and discharged to rivers in Western Pennsylvania with public drinking water system (PDWS) intakes. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to quantify inorganic species in wastewater and river samples using a method based on EPA Method 200.7 rev4.4. A total of 53 emission lines from 30 elements (Al, As, B, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn) were investigated. Samples were prepared by microwave-assisted acid digestion using a mixture of 2% HNO3 and 0.5% HCl. Lower interferences and better detection characteristics resulted in selection of alternative wavelengths for Al, As, Sb, Mg, Mo, and Na. Radial view measurements offered accurate determinations of Al, Ba, K, Li, Na, and Sr in high-brine samples. Spike recovery studies and analyses of reference materials showed 80-105% recoveries for most analytes. This method was used to quantify species in samples with high to low brine concentrations with method detection limits a factor of 2 below the maximum contaminant limit concentrations of national drinking water standards. Elements B, Ca, K, Li, Mg, Na, and Sr were identified as potential tracers for the sources impacting PDWS intakes. Usability of the ICP-OES derived data for factor analytic model applications was also demonstrated. Published by Elsevier B.V.

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario

NASA Astrophysics Data System (ADS)

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga; Parro, Víctor

2017-10-01

The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing.

Characterizing 3D sensors using the 3D modulation transfer function

NASA Astrophysics Data System (ADS)

Kellner, Timo; Breitbarth, Andreas; Zhang, Chen; Notni, Gunther

2018-03-01

The fields of optical 3D measurement system applications are continuously expanding and becoming more and more diverse. To evaluate appropriate systems for various measurement tasks, comparable parameters are necessary, whereas the 3D modulation transfer function (3D-MTF) has been established as a further criterion. Its aim is the determination of the system response between the measurement of a straight, sharp-edged cube and its opposite ideal calculated one. Within the scope of this work simulations and practical investigations regarding the 3D-MTF’s influences and its main issues are specifically investigated. Therefore, different determined edge radii representing the high-frequency spectra lead to various decreasing 3D-MTF characteristics. Furthermore, rising sampling frequencies improve its maximum transfer value to a saturation point in dependence of the radius. To approve these results of previous simulations, three fringe projection scanners were selected to determine the diversity. As the best 3D-MTF characteristic, a saturated transfer value of H_3D( f_N, 3D) = 0.79 has been identified at a sufficient sampling frequency, which is reached at four times the Nyquist limit. This high 3D resolution can mainly be achieved due to an improved camera projector interaction. Additionally, too small sampling ratios lead to uncertainties in the edge function determination, while higher ratios do not show major improvements. In conclusion, the 3D-MTF algorithm has thus been practically verified and its repeatability as well as its robustness have been confirmed.

Use of physical restraints in adult critical care: a bicultural study.

PubMed

Martin, Beth; Mathisen, Lars

2005-03-01

Although controversial, physical restraints are commonly used in adult critical care units in the United States to prevent treatment interference and self-inflicted harm. Use of physical restraints in Norwegian hospitals is very limited. In the United States, an experimental design for research on use of restraints has not seemed feasible. However, international research provides an opportunity to compare and contrast practices. To describe the relationship between patients' characteristics, environment, and use of physical restraints in the United States and Norway. Observations of patients and chart data were collected from 2 intensive care units (n = 50 patients) in Norway and 3 (n = 50 patients) in the United States. Sedation was measured by using the Sedation-Agitation Scale. The Nine Equivalents of Nursing Manpower Use Score was used to indicate patients' acuity level. Restraints were in use in 39 of 100 observations in the United States and not at all in Norway (P = .001). Categories of patients were balanced. In the Norwegian sample, the median Nine Equivalents of Nursing Manpower Use Score was higher (37 vs 27 points, P < .001), patients were more sedated (P < .001), and nurse-to-patient ratios were higher (1.05:1 vs 0.65:1, P < .001). Seven incidents of unplanned device removal were reported in the US sample. Critical care units with similar technology and characteristics of patients vary between nations in restraint practices, levels of sedation, and nurse-to-patient ratios. Restraint-free care was, in this sample, safe in terms of treatment interference.

Development of a bar adsorptive micro-extraction-large-volume injection-gas chromatography-mass spectrometric method for pharmaceuticals and personal care products in environmental water matrices.

PubMed

Neng, N R; Nogueira, J M F

2012-01-01

The combination of bar adsorptive micro-extraction using activated carbon (AC) and polystyrene-divinylbenzene copolymer (PS-DVB) sorbent phases, followed by liquid desorption and large-volume injection gas chromatography coupled to mass spectrometry, under selected ion monitoring mode acquisition, was developed for the first time to monitor pharmaceutical and personal care products (PPCPs) in environmental water matrices. Assays performed on 25 mL water samples spiked (100 ng L(-1)) with caffeine, gemfibrozil, triclosan, propranolol, carbamazepine and diazepam, selected as model compounds, yielded recoveries ranging from 74% to 99% under optimised experimental conditions (equilibrium time, 16 h (1,000 rpm); matrix characteristics: pH 5, 5% NaCl for AC phase; LD: methanol/acetonitrile (1:1), 45 min). The analytical performance showed good precision (RSD < 18%), convenient detection limits (5-20 ng L(-1)) and excellent linear dynamic range (20-800 ng L(-1)) with remarkable determination coefficients (r(2) > 0.99), where the PS-DVB sorbent phase showed a much better efficiency. By using the standard addition methodology, the application of the present analytical approach on tap, ground, sea, estuary and wastewater samples allowed very good performance at the trace level. The proposed method proved to be a suitable sorption-based micro-extraction alternative for the analysis of priority pollutants with medium-polar to polar characteristics, showing to be easy to implement, reliable, sensitive and requiring a low sample volume to monitor PPCPs in water matrices.

Trail resource impacts and an examination of alternative assessment techniques

USGS Publications Warehouse

Marion, J.L.; Leung, Y.-F.

2001-01-01

Trails are a primary recreation resource facility on which recreation activities are performed. They provide safe access to non-roaded areas, support recreational opportunities such as hiking, biking, and wildlife observation, and protect natural resources by concentrating visitor traffic on resistant treads. However, increasing recreational use, coupled with poorly designed and/or maintained trails, has led to a variety of resource impacts. Trail managers require objective information on trails and their conditions to monitor trends, direct trail maintenance efforts, and evaluate the need for visitor management and resource protection actions. This paper reviews trail impacts and different types of trail assessments, including inventory, maintenance, and condition assessment approaches. Two assessment methods, point sampling and problem assessment, are compared empirically from separate assessments of a 15-mile segment of the Appalachian Trail in Great Smoky Mountains National Park. Results indicate that point sampling and problem assessment methods yield distinctly different types of quantitative information. The point sampling method provides more accurate and precise measures of trail characteristics that are continuous or frequent (e.g., tread width or exposed soil). The problem assessment method is a preferred approach for monitoring trail characteristics that can be easily predefined or are infrequent (e.g., excessive width or secondary treads), particularly when information on the location of specific trail impact problems is needed. The advantages and limitations of these two assessment methods are examined in relation to various management and research information needs. The choice and utility of these assessment methods are also discussed.

Yoga in school settings: a research review.

PubMed

Khalsa, Sat Bir S; Butzer, Bethany

2016-06-01

Research on the efficacy of yoga for improving mental, emotional, physical, and behavioral health characteristics in school settings is a recent but growing field of inquiry. This systematic review of research on school-based yoga interventions published in peer-reviewed journals offers a bibliometric analysis that identified 47 publications. The studies from these publications have been conducted primarily in the United States (n = 30) and India (n = 15) since 2005, with the majority of studies (n = 41) conducted from 2010 onward. About half of the publications were of studies at elementary schools; most (85%) were conducted within the school curriculum, and most (62%) also implemented a formal school-based yoga program. There was a high degree of variability in yoga intervention characteristics, including overall duration, and the number and duration of sessions. Most of these published research trials are preliminary in nature, with numerous study design limitations, including limited sample sizes (median = 74; range = 20-660) and relatively weak research designs (57% randomized controlled trials, 19% uncontrolled trials), as would be expected in an infant research field. Nevertheless, these publications suggest that yoga in the school setting is a viable and potentially efficacious strategy for improving child and adolescent health and therefore worthy of continued research. © 2016 New York Academy of Sciences.

Social capital, friendship networks, and youth unemployment.

PubMed

Hällsten, Martin; Edling, Christofer; Rydgren, Jens

2017-01-01

Youth unemployment is a contemporary social problem in many societies. Youths often have limited access to information about jobs and limited social influence, yet little is known about the relationship between social capital and unemployment risk among youth. We study the effect of social capital on unemployment risk in a sample of 19 year olds of Swedish, Iranian, and Yugoslavian origin living in Sweden (N = 1590). We distinguish between two dimensions of social capital: occupational contact networks and friendship networks. First, ego's unemployment is found to be strongly associated with friends' unemployment among individuals of Yugoslavian origins and individuals of Swedish origin, but not Iranian origin. Second, occupational contact networks reduce unemployment risks for all groups, but especially so for Iranians. The effect sizes of the two dimensions are similar and substantial: going from low to high values on these measures is associated with a difference of some 60-70 percent relative difference in unemployment risk. The findings are robust to a number of different model specifications, including a rich set of social origin controls, personality traits, educational performance, friends' characteristics, and friendship network characteristics, as well as controls for geographical employment patterns. A sensitivity simulation shows that homogeneity bias need to be very strong to explain away the effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultra-high performance liquid chromatographic determination of levofloxacin in human plasma and prostate tissue with use of experimental design optimization procedures.

PubMed

Szerkus, O; Jacyna, J; Wiczling, P; Gibas, A; Sieczkowski, M; Siluk, D; Matuszewski, M; Kaliszan, R; Markuszewski, M J

2016-09-01

Fluoroquinolones are considered as gold standard for the prevention of bacterial infections after transrectal ultrasound guided prostate biopsy. However, recent studies reported that fluoroquinolone- resistant bacterial strains are responsible for gradually increasing number of infections after transrectal prostate biopsy. In daily clinical practice, antibacterial efficacy is evaluated only in vitro, by measuring the reaction of bacteria with an antimicrobial agent in culture media (i.e. calculation of minimal inhibitory concentration). Such approach, however, has no relation to the treated tissue characteristics and might be highly misleading. Thus, the objective of this study was to develop, with the use of Design of Experiments approach, a reliable, specific and sensitive ultra-high performance liquid chromatography- diode array detection method for the quantitative analysis of levofloxacin in plasma and prostate tissue samples obtained from patients undergoing prostate biopsy. Moreover, correlation study between concentrations observed in plasma samples vs prostatic tissue samples was performed, resulting in better understanding, evaluation and optimization of the fluoroquinolone-based antimicrobial prophylaxis during transrectal ultrasound guided prostate biopsy. Box-Behnken design was employed to optimize chromatographic conditions of the isocratic elution program in order to obtain desirable retention time, peak symmetry and resolution of levofloxacine and ciprofloxacine (internal standard) peaks. Fractional Factorial design 2(4-1) with four center points was used for screening of significant factors affecting levofloxacin extraction from the prostatic tissue. Due to the limited number of tissue samples the prostatic sample preparation procedure was further optimized using Central Composite design. Design of Experiments approach was also utilized for evaluation of parameter robustness. The method was found linear over the range of 0.030-10μg/mL for human plasma and 0.300-30μg/g for human prostate tissue samples. The intra-day and inter-day variability for levofloxacine from both plasma and prostate samples were less than 10%, with accuracies between 93 and 108% of the nominal values. The limit of detection and the limit of quantification for human plasma were 0.01μg/mL and 0.03μg/mL, respectively. For the prostate tissue, the limit of detection and the limit of quantification were 0.1μg/g and 0.3μg/g, respectively. The average recoveries of levofloxacin were in the range from 99 to 106%. Also, the method fulfills requirements of robustness what was determined and proved by Design of Experiments. The developed method was successfully applied to examine prostate tissue and plasma samples from 140 hospitalized patients enrolled into the clinical study, 12h after oral administration of LVF at a dose of 500mg. The mean (±SD) LVF concentration in prostate was 6.22±3.52μg/g and in plasma 2.54±1.14μg/mL. Due to simplicity of the method and relative small amount of sample needed for the assay, the method can be applied in clinical practice for monitoring of LVF concentrations in plasma and prostate gland. Copyright © 2016 Elsevier B.V. All rights reserved.

Interface and transport properties of metallization contacts to flat and wet-etching roughed N-polar n-type GaN.

PubMed

Wang, Liancheng; Liu, Zhiqiang; Guo, Enqing; Yang, Hua; Yi, Xiaoyan; Wang, Guohong

2013-06-26

The electrical characteristics of metallization contacts to flat (F-sample, without wet-etching roughed) and wet-etching roughed (R-sample) N-polar (Nitrogen-polar) n-GaN have been investigated. R-sample shows higher contact resistance (Rc) to Al/Ti/Au (~2.5 × 10(-5) Ω·cm(2)) and higher Schottky barriers height (SBH, ~0.386 eV) to Ni/Au, compared with that of F-sample (~1.3 × 10(-6) Ω·cm(2), ~0.154 eV). Reasons accounting for this discrepancy has been detail investigated and discussed: for R-sample, wet-etching process caused surface state and spontaneous polarization variation will degraded its electrical characteristics. Metal on R-sample shows smoother morphology, however, the effect of metal deposition state on electrical characteristics is negligible. Metallization contact area for both samples has also been further considered. Electrical characteristics of metallization contact to both samples show degradation upon annealing. The VLED chip (1 mm × 1 mm), which was fabricated on the basis of a hybrid scheme, coupling the advantage of F- and R-sample, shows the lowest forward voltage (2.75 V@350 mA) and the highest light output power.

The experimental research on response characteristics of coal samples under the uniaxial loading process

NASA Astrophysics Data System (ADS)

Jia, Bing; Wei, Jian-Ping; Wen, Zhi-Hui; Wang, Yun-Gang; Jia, Lin-Xing

2017-11-01

In order to study the response characteristics of infrasound in coal samples under the uniaxial loading process, coal samples were collected from GengCun mine. Coal rock stress loading device, acoustic emission tested system and infrasound tested system were used to test the infrasonic signal and acoustic emission signal under uniaxial loading process. The tested results were analyzed by the methods of wavelet filter, threshold denoise, time-frequency analysis and so on. The results showed that in the loading process, the change of the infrasonic wave displayed the characteristics of stage, and it could be divided into three stages: initial stage with a certain amount infrasound events, middle stage with few infrasound events, and late stage gradual decrease. It had a good consistency with changing characteristics of acoustic emission. At the same time, the frequency of infrasound was very low. It can propagate over a very long distance with little attenuation, and the characteristics of the infrasound before the destruction of the coal samples were obvious. A method of using the infrasound characteristics to predict the destruction of coal samples was proposed. This is of great significance to guide the prediction of geological hazards in coal mines.

Auditory Risk of Air Rifles

PubMed Central

Lankford, James E.; Meinke, Deanna K.; Flamme, Gregory A.; Finan, Donald S.; Stewart, Michael; Tasko, Stephen; Murphy, William J.

2016-01-01

Objective To characterize the impulse noise exposure and auditory risk for air rifle users for both youth and adults. Design Acoustic characteristics were examined and the auditory risk estimates were evaluated using contemporary damage-risk criteria for unprotected adult listeners and the 120-dB peak limit and LAeq75 exposure limit suggested by the World Health Organization (1999) for children. Study sample Impulses were generated by 9 pellet air rifles and 1 BB air rifle. Results None of the air rifles generated peak levels that exceeded the 140 dB peak limit for adults and 8 (80%) exceeded the 120 dB peak SPL limit for youth. In general, for both adults and youth there is minimal auditory risk when shooting less than 100 unprotected shots with pellet air rifles. Air rifles with suppressors were less hazardous than those without suppressors and the pellet air rifles with higher velocities were generally more hazardous than those with lower velocities. Conclusion To minimize auditory risk, youth should utilize air rifles with an integrated suppressor and lower velocity ratings. Air rifle shooters are advised to wear hearing protection whenever engaging in shooting activities in order to gain self-efficacy and model appropriate hearing health behaviors necessary for recreational firearm use. PMID:26840923

[Distribution Characteristics of Heavy Metals in Environmental Samples Around Electroplating Factories and the Health Risk Assessment].

PubMed

Guo, Peng-ran; Lei, Yong-qian; Zhou, Qiao-li; Wang, Chang; Pan, Jia-chuan

2015-09-01

This study aimed to investigate the pollution degree and human health risk of heavy metals in soil and air samples around electroplating factories. Soil, air and waste gas samples were collected to measure 8 heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in two electroplating factories, located in Baiyun district of Guangzhou city. Geoaccumulation index and USEPA Risk Assessment Guidance for Superfund (RAGS) were respectively carried out. Results showed that concentrations of Hg and Pb in waste gas and Cr in air samples were higher than limits of the corresponding quality standards, and concentrations of Cd, Hg and Zn in soil samples reached the moderate pollution level. The HQ and HI of exposure by heavy metals in air and soil samples were both lower than 1, indicating that there was no non-carcinogen risk. CRAs and CRCr in soil samples were beyond the maximum acceptable level of carcinogen risk (10(-4)), and the contribution rate of CRCr to TCR was over 81%. CRCr, CRNi and TCR in air samples were in range of 10(-6) - 10(-4), indicating there was possibly carcinogen risk but was acceptable risk. CR values for children were higher than adults in soils, but were higher for adults in air samples. Correlation analysis revealed that concentrations of heavy metals in soils were significantly correlated with these in waste gas samples, and PCA data showed pollution sources of Cd, Hg and Zn in soils were different from other metals.

Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

PubMed

Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2017-10-20

In using regularly collected or existing surveillance data to characterize engagement in human immunodeficiency virus (HIV) services among marginalized populations, differences in sampling methods may produce different pictures of the target population and may therefore result in different priorities for response. The objective of this study was to use existing data to evaluate the sample distribution of eight studies of female sex workers (FSW) and men who have sex with men (MSM), who were recruited using different sampling approaches in two locations within Sub-Saharan Africa: Manzini, Swaziland and Yaoundé, Cameroon. MSM and FSW participants were recruited using either respondent-driven sampling (RDS) or venue-based snowball sampling. Recruitment took place between 2011 and 2016. Participants at each study site were administered a face-to-face survey to assess sociodemographics, along with the prevalence of self-reported HIV status, frequency of HIV testing, stigma, and other HIV-related characteristics. Crude and RDS-adjusted prevalence estimates were calculated. Crude prevalence estimates from the venue-based snowball samples were compared with the overlap of the RDS-adjusted prevalence estimates, between both FSW and MSM in Cameroon and Swaziland. RDS samples tended to be younger (MSM aged 18-21 years in Swaziland: 47.6% [139/310] in RDS vs 24.3% [42/173] in Snowball, in Cameroon: 47.9% [99/306] in RDS vs 20.1% [52/259] in Snowball; FSW aged 18-21 years in Swaziland 42.5% [82/325] in RDS vs 8.0% [20/249] in Snowball; in Cameroon 15.6% [75/576] in RDS vs 8.1% [25/306] in Snowball). They were less educated (MSM: primary school completed or less in Swaziland 42.6% [109/310] in RDS vs 4.0% [7/173] in Snowball, in Cameroon 46.2% [138/306] in RDS vs 14.3% [37/259] in Snowball; FSW: primary school completed or less in Swaziland 86.6% [281/325] in RDS vs 23.9% [59/247] in Snowball, in Cameroon 87.4% [520/576] in RDS vs 77.5% [238/307] in Snowball) than the snowball samples. In addition, RDS samples indicated lower exposure to HIV prevention information, less knowledge about HIV prevention, limited access to HIV prevention tools such as condoms, and less-reported frequency of sexually transmitted infections (STI) and HIV testing as compared with the venue-based samples. Findings pertaining to the level of disclosure of sexual practices and sexual practice-related stigma were mixed. Samples generated by RDS and venue-based snowball sampling produced significantly different prevalence estimates of several important characteristics. These findings are tempered by limitations to the application of both approaches in practice. Ultimately, these findings provide further context for understanding existing surveillance data and how differences in methods of sampling can influence both the type of individuals captured and whether or not these individuals are representative of the larger target population. These data highlight the need to consider how program coverage estimates of marginalized populations are determined when characterizing the level of unmet need. ©Amrita Rao, Shauna Stahlman, James Hargreaves, Sharon Weir, Jessie Edwards, Duncan Kochelani, Duncan Kochelani, Mpumelelo Mavimbela, Stefan Baral. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 20.10.2017.

Updating categorical soil maps using limited survey data by Bayesian Markov chain cosimulation.

PubMed

Li, Weidong; Zhang, Chuanrong; Dey, Dipak K; Willig, Michael R

2013-01-01

Updating categorical soil maps is necessary for providing current, higher-quality soil data to agricultural and environmental management but may not require a costly thorough field survey because latest legacy maps may only need limited corrections. This study suggests a Markov chain random field (MCRF) sequential cosimulation (Co-MCSS) method for updating categorical soil maps using limited survey data provided that qualified legacy maps are available. A case study using synthetic data demonstrates that Co-MCSS can appreciably improve simulation accuracy of soil types with both contributions from a legacy map and limited sample data. The method indicates the following characteristics: (1) if a soil type indicates no change in an update survey or it has been reclassified into another type that similarly evinces no change, it will be simply reproduced in the updated map; (2) if a soil type has changes in some places, it will be simulated with uncertainty quantified by occurrence probability maps; (3) if a soil type has no change in an area but evinces changes in other distant areas, it still can be captured in the area with unobvious uncertainty. We concluded that Co-MCSS might be a practical method for updating categorical soil maps with limited survey data.

Updating Categorical Soil Maps Using Limited Survey Data by Bayesian Markov Chain Cosimulation

PubMed Central

Dey, Dipak K.; Willig, Michael R.

2013-01-01

Updating categorical soil maps is necessary for providing current, higher-quality soil data to agricultural and environmental management but may not require a costly thorough field survey because latest legacy maps may only need limited corrections. This study suggests a Markov chain random field (MCRF) sequential cosimulation (Co-MCSS) method for updating categorical soil maps using limited survey data provided that qualified legacy maps are available. A case study using synthetic data demonstrates that Co-MCSS can appreciably improve simulation accuracy of soil types with both contributions from a legacy map and limited sample data. The method indicates the following characteristics: (1) if a soil type indicates no change in an update survey or it has been reclassified into another type that similarly evinces no change, it will be simply reproduced in the updated map; (2) if a soil type has changes in some places, it will be simulated with uncertainty quantified by occurrence probability maps; (3) if a soil type has no change in an area but evinces changes in other distant areas, it still can be captured in the area with unobvious uncertainty. We concluded that Co-MCSS might be a practical method for updating categorical soil maps with limited survey data. PMID:24027447

Trauma memory characteristics and the development of acute stress disorder and post-traumatic stress disorder in youth.

PubMed

McKinnon, A; Brewer, N; Meiser-Stedman, R; Nixon, R D V

2017-03-01

The present study addresses gaps in knowledge regarding the association between trauma memory processes and posttraumatic stress responses in youth. Our primary goal was to explore the relative contribution of perceptions of trauma memory quality versus narrative trauma memory characteristics to explain overall adjustment. Children (N = 67) were interviewed within four weeks (T1) of an injury leading to hospital treatment and then again eight weeks later (T2). In each interview, the child told a trauma narrative (which were later coded), and answered the Trauma Memory Quality Questionnaire (Meiser-Stedman, Smith, Yule, & Dalgleish, 2007a), a self-report measure indexing the sensory, fragmented, and disorganised characteristics of trauma memory. They then completed measures of Acute Stress Disorder (ASD) symptoms and associated psychopathology at T1 and measures of Posttraumatic Stress (PTS) symptoms and associated psychopathology at T2. Self-reported trauma memory characteristics predicted ASD symptoms cross-sectionally at T1 and PTS symptoms prospectively over time. At both time points, self-reported trauma memory characteristics accounted for all of the unique variance in symptoms initially explained by narrative characteristics. A reduction in self-report ratings, but not the hypothesised narrative features (e.g., disorganised or lexical elements of the narrative), significantly predicted a reduction in PTS symptoms over time. The small sample size and the absence of a within-subjects narrative control were the main limitations of the study. These findings underscore the importance of self-reported trauma memory characteristics to the aetiology of PTSD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of the patient with an ostomy.

PubMed

Pittman, Joyce

2011-01-01

Complications following intestinal and urinary diversion (OSTOMY) surgery are a significant problem for many individuals. Patient characteristics or risk factors have been associated with the development of ostomy complications, but research in this area is limited. To examine the demographic and clinical characteristics of new ostomy patients. Descriptive, cross-sectional study. A convenience sample of 144 new ostomy patients was recruited from a large midwest urban level i trauma teaching hospital system. A descriptive, cross-sectional design was used to examine the demographic and clinical characteristics in persons with a new ostomy. demographic and clinical characteristics included were age, gender, disposition, diagnosis, ostomy type, type of procedure (emergent or elective), stoma type (temporary or permanent), technique of stoma creation (loop or end), stoma site marked preoperatively, body type, stoma height, and complicating factors. Data were collected through a medical record review and direct observation by the WOC nurse. Significant differences were found among demographic and clinical characteristics and ostomy type and disposition. Age, type of procedure, reason for surgery, stoma type, stoma site marking, and complicating factors were significantly different by ostomy type. The majority of stomas were not marked preoperatively (67%). Sixty-eight percent of persons with a stoma above skin level versus 38% with a stoma below skin level were discharged to their home. Statistically significant relationships were found among disposition and type of procedure (P = .036), stoma height (P = .003), reason for surgery (P = .000), and age (P = .005). This study provides additional information regarding specific patient characteristics (demographic and clinical) and their relationship to ostomy type and disposition.

A statistical model and national data set for partioning fish-tissue mercury concentration variation between spatiotemporal and sample characteristic effects

USGS Publications Warehouse

Wente, Stephen P.

2004-01-01

Many Federal, Tribal, State, and local agencies monitor mercury in fish-tissue samples to identify sites with elevated fish-tissue mercury (fish-mercury) concentrations, track changes in fish-mercury concentrations over time, and produce fish-consumption advisories. Interpretation of such monitoring data commonly is impeded by difficulties in separating the effects of sample characteristics (species, tissues sampled, and sizes of fish) from the effects of spatial and temporal trends on fish-mercury concentrations. Without such a separation, variation in fish-mercury concentrations due to differences in the characteristics of samples collected over time or across space can be misattributed to temporal or spatial trends; and/or actual trends in fish-mercury concentration can be misattributed to differences in sample characteristics. This report describes a statistical model and national data set (31,813 samples) for calibrating the aforementioned statistical model that can separate spatiotemporal and sample characteristic effects in fish-mercury concentration data. This model could be useful for evaluating spatial and temporal trends in fishmercury concentrations and developing fish-consumption advisories. The observed fish-mercury concentration data and model predictions can be accessed, displayed geospatially, and downloaded via the World Wide Web (http://emmma.usgs.gov). This report and the associated web site may assist in the interpretation of large amounts of data from widespread fishmercury monitoring efforts.

An Investigation of the Sampling Distributions of Equating Coefficients.

ERIC Educational Resources Information Center

Baker, Frank B.

1996-01-01

Using the characteristic curve method for dichotomously scored test items, the sampling distributions of equating coefficients were examined. Simulations indicate that for the equating conditions studied, the sampling distributions of the equating coefficients appear to have acceptable characteristics, suggesting confidence in the values obtained…

Salmonella enteritidis surveillance by egg immunology: impact of the sampling scheme on the release of contaminated table eggs.

PubMed

Klinkenberg, Don; Thomas, Ekelijn; Artavia, Francisco F Calvo; Bouma, Annemarie

2011-08-01

Design of surveillance programs to detect infections could benefit from more insight into sampling schemes. We address the effect of sampling schemes for Salmonella Enteritidis surveillance in laying hens. Based on experimental estimates for the transmission rate in flocks, and the characteristics of an egg immunological test, we have simulated outbreaks with various sampling schemes, and with the current boot swab program with a 15-week sampling interval. Declaring a flock infected based on a single positive egg was not possible because test specificity was too low. Thus, a threshold number of positive eggs was defined to declare a flock infected, and, for small sample sizes, eggs from previous samplings had to be included in a cumulative sample to guarantee a minimum flock level specificity. Effectiveness of surveillance was measured by the proportion of outbreaks detected, and by the number of contaminated table eggs brought on the market. The boot swab program detected 90% of the outbreaks, with 75% fewer contaminated eggs compared to no surveillance, whereas the baseline egg program (30 eggs each 15 weeks) detected 86%, with 73% fewer contaminated eggs. We conclude that a larger sample size results in more detected outbreaks, whereas a smaller sampling interval decreases the number of contaminated eggs. Decreasing sample size and interval simultaneously reduces the number of contaminated eggs, but not indefinitely: the advantage of more frequent sampling is counterbalanced by the cumulative sample including less recently laid eggs. Apparently, optimizing surveillance has its limits when test specificity is taken into account. © 2011 Society for Risk Analysis.

Nonlinear threshold effect in the Z-scan method of characterizing limiters for high-intensity laser light

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

Tereshchenko, S. A., E-mail: tsa@miee.ru; Savelyev, M. S.; Podgaetsky, V. M.

A threshold model is described which permits one to determine the properties of limiters for high-powered laser light. It takes into account the threshold characteristics of the nonlinear optical interaction between the laser beam and the limiter working material. The traditional non-threshold model is a particular case of the threshold model when the limiting threshold is zero. The nonlinear characteristics of carbon nanotubes in liquid and solid media are obtained from experimental Z-scan data. Specifically, the nonlinear threshold effect was observed for aqueous dispersions of nanotubes, but not for nanotubes in solid polymethylmethacrylate. The threshold model fits the experimental Z-scanmore » data better than the non-threshold model. Output characteristics were obtained that integrally describe the nonlinear properties of the optical limiters.« less

Adolescent precursors of adult borderline personality pathology in a high-risk community sample.

PubMed

Conway, Christopher C; Hammen, Constance; Brennan, Patricia A

2015-06-01

Longitudinal studies of the exact environmental conditions and personal attributes contributing to the development of borderline personality disorder (BPD) are rare. Furthermore, existing research typically examines risk factors in isolation, limiting our knowledge of the relative effect sizes of different risk factors and how they act in concert to bring about borderline personality pathology. The present study investigated the prospective effects of diverse acute and chronic stressors, proband psychopathology, and maternal psychopathology on BPD features in a high-risk community sample (N = 700) of youth followed from mid-adolescence to young adulthood. Multivariate analyses revealed significant effects of maternal externalizing disorder history, offspring internalizing disorder history, family stressors, and school-related stressors on BPD risk. Contrary to expectations, no interactions between chronically stressful environmental conditions and personal characteristics in predicting borderline personality features were detected. Implications of these findings for etiological theories of BPD and early screening efforts are discussed.

Small target pre-detection with an attention mechanism

NASA Astrophysics Data System (ADS)

Wang, Yuehuan; Zhang, Tianxu; Wang, Guoyou

2002-04-01

We introduce the concept of predetection based on an attention mechanism to improve the efficiency of small-target detection by limiting the image region of detection. According to the characteristics of small-target detection, local contrast is taken as the only feature in predetection and a nonlinear sampling model is adopted to make the predetection adaptive to detect small targets with different area sizes. To simplify the predetection itself and decrease the false alarm probability, neighboring nodes in the sampling grid are used to generate a saliency map, and a short-term memory is adopted to accelerate the `pop-out' of targets. We discuss the fact that the proposed approach is simple enough in computational complexity. In addition, even in a cluttered background, attention can be led to targets in a satisfying few iterations, which ensures that the detection efficiency will not be decreased due to false alarms. Experimental results are presented to demonstrate the applicability of the approach.

Perceived job insecurity and worker health in the United States

PubMed Central

Burgard, Sarah A.; Brand, Jennie E; House, James S

2009-01-01

Economic recessions, the industrial shift from manufacturing toward service industries, and rising global competition have contributed to uncertainty about job security, with potential consequences for workers’ health. To address limitations of prior research on the health consequences of perceived job insecurity, we use longitudinal data from two nationally-representative samples of the United States population, and examine episodic and persistent perceived job insecurity over periods of about three years to almost a decade. Results show that persistent perceived job insecurity is a significant and substantively important predictor of poorer self-rated health in the American’s Changing Lives (ACL) and Midlife in the United States (MIDUS) samples, and of depressive symptoms among ACL respondents. Job losses or unemployment episodes are associated with perceived job insecurity, but do not account for its association with health. Results are robust to controls for sociodemographic and job characteristics, negative reporting style, and earlier health and health behaviors. PMID:19596166

Definitions of homework, types of homework, and ratings of the importance of homework among psychologists with cognitive behavior therapy and psychoanalytic theoretical orientations.

PubMed

Kazantzis, Nikolaos; Dattilio, Frank M

2010-07-01

A random sample of 827 psychologists were surveyed to assess their definitions of homework, use of homework tasks, and perceived importance of homework. Theoretical orientation distinguished practitioners' responses. Cognitive-behavioral therapists defined homework as being closer to empirically supported therapy, whereas psychodynamic therapists rated homework as less characteristic of a process that embraces client responsibility and adaptive skills. Cognitive-behavior therapists did not limit their choices to activity-based tasks, and psychodynamic therapists reported using behavioral tasks "sometimes." Monitoring dreams and conscious thought were also used among the entire sample surveyed. Psychodynamic therapists rated homework as "somewhat" or "moderately" important, whereas cognitive-behavior therapists more often rated homework as "very important." Data suggest some homework may be common to different psychotherapeutic approaches. Findings are discussed in the context of recent theoretical work on homework in psychotherapy and recommendations for future research.

Sachet water quality and brand reputation in two low-income urban communities in greater Accra, Ghana.

PubMed

Stoler, Justin; Tutu, Raymond A; Ahmed, Hawa; Frimpong, Lady Asantewa; Bello, Mohammed

2014-02-01

Sachet water has become an important primary source of drinking water in western Africa, but little is known about bacteriologic quality and improvements to quality control given the recent, rapid evolution of this industry. This report examines basic bacteriologic indicators for 60 sachet water samples from two very low-income communities in Accra, Ghana, and explores the relationship between local perceptions of brand quality and bacteriologic quality after controlling for characteristics of the vending environment. No fecal contamination was detected in any sample, and 82% of total heterotrophic bacteria counts were below the recommended limit for packaged water. Sachets from brands with a positive reputation for quality were 90% less likely to present any level of total heterotrophic bacteria after controlling for confounding factors. These results contrast with much of the recent sachet water quality literature and may indicate substantial progress in sachet water regulation and quality control.

Field of first magnetic flux entry and pinning strength of superconductors for rf application measured with muon spin rotation

DOE PAGES

Junginger, Tobias; Abidi, S. H.; Maffett, R. D.; ...

2018-03-16

Here, the performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry H entry and pinning strength. The former sets the limit for the maximum achievable accelerating gradient, while the latter determines how efficiently flux can be expelled related to the maximum achievable quality factor. In this paper, a method based on muon spin rotation (μSR) is developed to probe these parameters on samples. It combines measurements from two different spectrometers, one being specifically built for these studies and samples of different geometries. It is found that annealing atmore » 1400°C virtually eliminates all pinning. Such an annealed substrate is ideally suited to measure H entry of layered superconductors, which might enable accelerating gradients beyond bulk niobium technology.« less

Influence of thin-film metallic glass coating on fatigue behavior of bulk metallic glass: Experiments and finite element modeling

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

Yu, Chia-Chi; Chu, Jinn P.; Jia, Haoling

In this paper, a coating of the Zr-based thin-film metallic glass (TFMG) was deposited on the Zr 50Cu 30Al 10Ni 10 bulk metallic glass (BMG) to investigate shear-band evolution under four-point-bend fatigue testing. The fatigue endurance-limit of the TFMG-coated samples is ~ 33% higher than that of the BMG. The results of finite-element modeling (FEM) revealed a delay in the shear-band nucleation and propagation in TFMG-coated samples under applied cyclic-loading. The FEM study of spherical indentation showed that the redistribution of stress by the TFMG coating prevents localized shear-banding in the BMG substrate. Finally, the enhanced fatigue characteristics of themore » BMG substrates can be attributed to the TFMG coatings retarding shear-band initiation at defects on the surface of the BMG.« less

Influence of thin-film metallic glass coating on fatigue behavior of bulk metallic glass: Experiments and finite element modeling

DOE PAGES

Yu, Chia-Chi; Chu, Jinn P.; Jia, Haoling; ...

2017-03-21

In this paper, a coating of the Zr-based thin-film metallic glass (TFMG) was deposited on the Zr 50Cu 30Al 10Ni 10 bulk metallic glass (BMG) to investigate shear-band evolution under four-point-bend fatigue testing. The fatigue endurance-limit of the TFMG-coated samples is ~ 33% higher than that of the BMG. The results of finite-element modeling (FEM) revealed a delay in the shear-band nucleation and propagation in TFMG-coated samples under applied cyclic-loading. The FEM study of spherical indentation showed that the redistribution of stress by the TFMG coating prevents localized shear-banding in the BMG substrate. Finally, the enhanced fatigue characteristics of themore » BMG substrates can be attributed to the TFMG coatings retarding shear-band initiation at defects on the surface of the BMG.« less

To what extent is quality of life impaired in vitiligo? A multicenter study on Italian patients using the dermatology life quality index.

PubMed

Ingordo, Vito; Cazzaniga, Simone; Medri, Matelda; Raone, Beatrice; Digiuseppe, Maria Donata; Musumeci, Maria Letizia; Romano, Ivana; Fai, Dario; Pellegrino, Michele; Pezzarossa, Enrico; Di Lernia, Vito; Peccerillo, Francesca; Battarra, Vincenzo Claudio; Sirna, Riccardo; Patrizi, Annalisa; Naldi, Luigi

2014-01-01

It is believed that vitiligo has an impact on the overall patient quality of life (QoL). To estimate QoL in a fairly large sample of Italian vitiligo patients by using the Dermatology Life Quality Index (DLQI) questionnaire. One hundred and sixty-one vitiligo patients referred to 9 dermatological centers were offered to participate by filling in the Italian version of the DLQI questionnaire. The mean total DLQI score was 4.3 (SD ±4.9; range: 0-22). In multivariate analysis, DLQI >5 was associated with female gender, stability of the disease over time and involvement of the face at disease onset. The impairment of QoL is overall limited in Italian vitiligo patients, especially if it is compared with results from other available studies. This could be due to cultural and ethnic characteristics of the sample.

Optimizing ultrafast illumination for multiphoton-excited fluorescence imaging

PubMed Central

Stoltzfus, Caleb R.; Rebane, Aleksander

2016-01-01

We study the optimal conditions for high throughput two-photon excited fluorescence (2PEF) and three-photon excited fluorescence (3PEF) imaging using femtosecond lasers. We derive relations that allow maximization of the rate of imaging depending on the average power, pulse repetition rate, and noise characteristics of the laser, as well as on the size and structure of the sample. We perform our analysis using ~100 MHz, ~1 MHz and 1 kHz pulse rates and using both a tightly-focused illumination beam with diffraction-limited image resolution, as well loosely focused illumination with a relatively low image resolution, where the latter utilizes separate illumination and fluorescence detection beam paths. Our theoretical estimates agree with the experiments, which makes our approach especially useful for optimizing high throughput imaging of large samples with a field-of-view up to 10x10 cm2. PMID:27231620

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

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

PubMed

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

2004-03-01

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

Containerless Studies of Nucleation and Undercooling

NASA Technical Reports Server (NTRS)

Trinh, E. H.

1985-01-01

The long term research goals are to perform experiments to determine the achievable limits of undercooling, the characteristics of heterogeneous nucleation, and the physical properties of significantly undercooled melts. The techniques used are based on the newly developed containerless manipulation methods afforded by acoustic levitation. Ground based investigations involved 0.1 to 2 mm specimens of pure metals and alloys (In, Ga, Sn, Ga-In, ...) as well as glass-forming organic compounds (O-Terphenyl). A currently operating ultrasonic high temperature apparatus has allowed the ground-based levitation of 1 to 2 mm samples of solid aluminum at 550 deg C in an argon atmosphere. Present work is concentrating on the undercooling of pure metal samples (In, Sn), and on the measurements of surface tension and viscosity of the undercooled melts via shape oscillation techniques monitored through optical detection methods. The sound velocity of undercooled O-Terphenyl is being measured in an immiscible liquid levitation cells.