Organic SIMS: the influence of time on the ion yield enhancement by silver and gold deposition

NASA Astrophysics Data System (ADS)

Adriaensen, L.; Vangaever, F.; Gijbels, R.

2004-06-01

A series of organic dyes and pharmaceuticals was used to study the secondary ion yield enhancement by metal deposition. The molecules were dissolved in methanol and spincasted on silicon substrates. Subsequently, silver or gold was evaporated on the samples to produce a very thin coating. The coated samples, when measured with TOF-SIMS, showed a considerable increase in characteristic secondary ion intensity. Gold-evaporated samples appear to exhibit the highest signal enhancement. These observations apply to organic samples in general, an advantage that allows to use the technique of metal deposition on real-world samples. However, the observed signal increase does not occur at any given moment. The time between metal deposition on the sample surface and the measuring of the sample with TOF-SIMS appears to have an important influence on the enhancement of the secondary ion intensities. In consideration of these observations several experiments were carried out, in which the spincasted samples were measured at different times after sample preparation, i.e., after gold or silver was deposited on the sample surface. The results show that, depending on the sample and the metal deposited, the secondary ion signals reach their maximum at different times. Further study will be necessary to detect the mechanism responsible for the observed enhancement effect.

The Complete Local-Volume Groups Sample (CLoGS): Early results from X-ray and radio observations

NASA Astrophysics Data System (ADS)

Vrtilek, Jan M.; O'Sullivan, Ewan; David, Laurence P.; Giacintucci, Simona; Kolokythas, Konstantinos

2017-08-01

Although the group environment is the dominant locus of galaxy evolution (in contrast to rich clusters, which contain only a few percent of galaxies), there has been a lack of reliable, representative group samples in the local Universe. In particular, X-ray selected samples are strongly biased in favor of the X-ray bright, centrally-concentrated cool-core systems. In response, we have designed the Complete Local-Volume Groups Sample (CLoGS), an optically-selected statistically-complete sample of 53 groups within 80 Mpc which is intended to overcome the limitations of X-ray selected samples and serve as a representative survey of groups in the local Universe. We have supplemented X-ray data from Chandra and XMM (70% complete to date, using both archival and new observations, with a 26-group high richness subsample 100% complete) with GMRT radio continuum observations (at 235 and 610 MHz, complete for the entire sample). CLoGS includes groups with a wide variety of properties in terms of galaxy population, hot gas content, and AGN power. We here describe early results from the survey, including the range of AGN activity observed in the dominant galaxies, the relative fraction of cool-core and non-cool-core groups in our sample, and the degree of disturbance observed in the IGM.

Screenometer: a device for sampling vegetative screening in forested areas

Treesearch

Victor A. Rudis

1985-01-01

A-device for estimating the degree to which vegetation and other obstructions screen forested areas has been adapted to an extensive sampling design for forest surveys. Procedures are recommended to assure that uniform measurements can be made. Examination of sources of sampling variation (observers, points within sampled locations, series of observations within points...

Exact intervals and tests for median when one sample value possibly an outliner

NASA Technical Reports Server (NTRS)

Keller, G. J.; Walsh, J. E.

1973-01-01

Available are independent observations (continuous data) that are believed to be a random sample. Desired are distribution-free confidence intervals and significance tests for the population median. However, there is the possibility that either the smallest or the largest observation is an outlier. Then, use of a procedure for rejection of an outlying observation might seem appropriate. Such a procedure would consider that two alternative situations are possible and would select one of them. Either (1) the n observations are truly a random sample, or (2) an outlier exists and its removal leaves a random sample of size n-1. For either situation, confidence intervals and tests are desired for the median of the population yielding the random sample. Unfortunately, satisfactory rejection procedures of a distribution-free nature do not seem to be available. Moreover, all rejection procedures impose undesirable conditional effects on the observations, and also, can select the wrong one of the two above situations. It is found that two-sided intervals and tests based on two symmetrically located order statistics (not the largest and smallest) of the n observations have this property.

Comparison of Environmental Scanning Electron Microscopy in Low Vacuum or wet mode for the investigation of cell biomaterial interactions.

PubMed

Mattarozzi, Monica; Manfredi, Edoardo; Lorenzi, Andrea; Smerieri, Arianna; Di Blasio, Alberto; Macaluso, Guido; Lumetti, Simone; Galli, Carlo

2016-05-06

The aim of the present study was to investigate the efficacy of environmental scanning electron microscopy (ESEM), in low vacuum mode (LV-ESEM) and in wet mode (wet-ESEM) in the assessment of cell-material interactions. Mouse calvaria MC3T3 cells (ATCC) were seeded on commercially pure machined titanium discs of 10 mm diameter in Dulbecco modified MEM, 10% Fetal Bovine Serum, 1% Penicillin and Streptomycin and 1% Glutamine. Samples were then processed for microscope observation by rinse in Phosphate Buffer saline and fixation in 4.5% Glutaraldehyde. Samples were then rinsed in Sodium Cacodylate buffer and observed or dehydrated in alcohol prior to LV-ESEM observation. Fresh samples in 0.9% NaCl solution were observed in wet- ESEM. No significant loss of detail was observed when dehydrated or non dehydrated samples were analysed at LV-ESEM.The observation of fresh samples in wet-ESEM however proved difficult for the need to eliminate water which forms a layer covering the sample, thus hiding cell surface details. When reducing the vapor pressure in the chamber, the layer evaporated and NaCl immediately started to precipitate and cells collapsed, thus no further investigation was possible. The use of low vacuum-ESEM after cell fixation, but without dehydration or gold sputter coating proved a viable alternative to traditional high vacuum SEM observation.

Effect of defocusing on laser ablation plume observed by laser-induced fluorescence imaging spectroscopy

NASA Astrophysics Data System (ADS)

Oba, Masaki; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo

2016-02-01

We used laser-induced fluorescence imaging with a varying beam focal point to observe ablation plumes from metal and oxide samples of gadolinium. The plumes expand vertically when the focal point is far from the sample surface. In contrast, the plume becomes hemispherical when the focal point is on the sample surface. In addition, the internal plume structure and the composition of the ablated atomic and ionic particles also vary significantly. The fluorescence intensity of a plume from a metal sample is greater than that from an oxide sample, which suggests that the number of monatomic species produced in each plume differs. For both the metal and oxide samples, the most intense fluorescence from atomic (ionic) species is observed with the beam focal point at 3-4 mm (2 mm) from the sample surface.

Magnetic studies of CuFe{sub 2}O{sub 4} nanoparticles prepared by co-precipitation method

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

Subha, A.; Shalini, M. Govindaraj; Sahoo, Subasa C., E-mail: subasa@cukerala.ac.in

2016-05-06

Cu-ferrite nanoparticles were synthesized by co-precipitation method and were annealed at different temperatures ranging from 400 to l000°C in air for 4 hours. The as-prepared sample and the sample annealed at 400°C showed small peaks of cubic Cu-ferrite in X-ray diffraction studies. For the intermediate temperature 600°C, some additional peaks of α-Fe{sub 2}O{sub 3} were observed. As the annealing temperature increased further only tetragonal Cu-ferrite peaks were observed. In all the samples some traces of CuO was noted. Grain size was increased from 2lnm for the as prepared sample to 42nm for the sample annealed at l000°C. Spontaneous magnetization valuemore » was found to be very small for the as prepared sample and it was increased monotonically with the increase in annealing temperature. Maximum magnetization of 29.7emu/g was observed at 300K for the sample annealed at l000°C. The remanent magnetization was increased with the increase in annealing temperature up to 900°C and then decreased whereas for the coercivity a peak was observed for the sample annealed at 800°C. The highest coercivity of l402 Oe was observed at 300K for the sample annealed at 800°C. As the measurement temperature decreased from 300K to 60K, magnetization and coercivity values were increased. The observed magnetic behaviour may be understood on the basis of phase transformation, grain growth with the increase in annealing temperature and reduced thermal energy at low measurement temperature.« less

Phylogenetic analysis of G1P[8] and G12P[8] rotavirus A samples obtained in the pre- and post-vaccine periods, and molecular modeling of VP4 and VP7 proteins.

PubMed

Almeida, Tâmera Nunes Vieira; de Sousa, Teresinha Teixeira; da Silva, Roosevelt Alves; Fiaccadori, Fabíola Souza; Souza, Menira; Badr, Kareem Rady; de Paula Cardoso, Divina das Dôres

2017-09-01

Reduction in morbimortality rates for acute gastroenteritis (AGE) by Rotavirus A (RVA) has been observed after the introduction of vaccines, however the agent continues to circulate. The present study described the genomic characterization of the 11 dsRNA segments of two RVA samples G1P[8] obtained in the pre- and post-vaccination periods and one of G12P[8] sample (post-vaccine), compared to Rotarix™ vaccine. Analysis by molecular sequencing of the samples showed that the three samples belonged to genogroup I. In addition, the analysis of VP7 gene revealed that the samples G1 (pre-vaccine), G1 (post-vaccine) and G12 were characterized as lineages II, I and III, respectively. Regarding to VP4 and NSP4 gene it was observed that all samples belonged to lineage III, whereas for VP6 gene, the sample of the pre- and post-vaccine belonged to the lineage IV and I, respectively. Considering the VP7 gene, it was observed high nucleotide and amino acid identity for the two G1 samples when compared to Rotarix™ vaccine and lesser identity for the G12 sample. In relation to antigenic epitope of VP7 greater modifications were observed for the G12 sample in the 7-2 epitope that was confirmed by molecular modeling. On the other hand, for VP4, some changes in the 8-1 and 8-3 antigenic epitopes was observed for the three samples. This data could be interpreted as a low selective pressure exerted by vaccination in relation to G1P[8] samples and lesser protection in relation to G12P[8]. Thus, the continuous monitoring of RVA circulating samples remains important. Copyright © 2017 Elsevier B.V. All rights reserved.

Solvent hold tank sample results for MCU-17-150-152 (July 2017) and MCU-17-153-155 (August 2017): Quarterly report

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

Fondeur, F.; Jones, D.

A trend summary that includes the last two Solvent Hold Tank (SHT) monthly samples is shown; MCU- 17-150-152 (July SHT) and MCU-17-153-155 (August SHT). Since the last SHT sample sent for analysis was the August sample the chemical state of the solvent is best approximated by the chemical analysis of the August SHT sample (MCU-17-153-155). This report mainly focused on the chemical analysis of the August SHT sample. The analysis data from the July SHT sample are presented in the “trend” plots of this report. Analysis of the August SHT sample (MCU-17-153-155) indicated that the modifier (CS-7SB) was 2% belowmore » but the extractant (MaxCalix) concentration was at its nominal recommended level (169,000 mg/L and 46,400 mg/L respectively). The suppressor (TiDG) level has decreased since the last measurement taken while the Modular Caustic-Side Solvent Extraction unit (MCU) was operating in January 2017, but has remained steady in the range of 666 (observed in April) to 715 mg/L (observed in the August 2017 sample) since February 2017, well above the minimum recommended level (479 mg/L), but below the nominal level. The “flat” trends observed in the TiDG, MaxCalix, modifier, and Gamma measurement are consistent with the solvent being idle since January 10, 2017. A strong correlation between density and modifier concentration in the solvent continues to be observed in the SHT samples. This analysis confirms the Isopar™L addition to the solvent in January 2017. This analysis also indicates the solvent did not require further additions. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time if the Modular Caustic-Side Solvent Extraction Unit (MCU) returns to processing radioactive liquid waste. Otherwise, the levels of these components will remain steady. A future Isopar™L trimming addition to the solvent is recommended when MCU resumes processing waste. Two unknown impurities related to the modifier (but not sec-butyl phenol: a modifier degradation product observed before) at the 290 and 110 mg/L levels were observed in the August SHT sample by the Gas - Chromatography-Mass Spectrometry (GC-MS) method. They were observed in a second GC-MS re-run with a new column. Their identification can’t be ascertained at this time. No impurities were observed in the Hydrogen Nuclear Magnetic Resonance (HNMR). Another impurity observed in the samples was mercury. Based on the August SHT sample, up to 23 ± 5 micrograms of mercury per mL of solvent was detected (the average of the Cold Vapor-Atomic Adsorption [CV-AA] and X-Ray Fluorescence [XRF] methods). The higher mercury concentration in the solvent (as determined in the last three-monthly samples) is possibly due to either a higher mercury concentration in Salt Batches 8 and 9 (Tank 49H) . The gamma level (~ 2.0E4 dpm/mL) measured in the August SHT samples was one order of magnitude lower than the gamma levels observed in the December 2016 and January 2017 SHT samples. A similar level was observed in the July SHT sample (MCU-SHT-150-152). The gamma level has remained consistently steady since January 10, 2017 when MCU stopped processing radioactive liquid waste. The laboratory will continue to monitor the quality of the solvent in particularly for any new impurities or degradation of the solvent components.« less

Negative and positive magnetoresistance in GaInNAs/GaAs modulation-doped quantum well structures

NASA Astrophysics Data System (ADS)

Nutku, Ferhat; Donmez, Omer; Sarcan, Fahrettin; Erol, Ayşe; Puustinen, Janne; Arıkan, Mehmet Çetin; Guina, Mircea

2015-03-01

In this work, magnetoresistance of as-grown and annealed n- and p-type modulation-doped Ga0.68In0.32NyAs1-y/GaAs single quantum well structures with various nitrogen concentrations has been studied. At low temperatures and low magnetic fields, in n-type samples negative and in p-type samples positive, magnetoresistance has been observed. The observed negative magnetoresistance in n-type samples is an indication of enhanced backscattering of electrons due to the weak localization of the electrons as an effect of the N-induced defects. Nitrogen concentration and thermal annealing dependence of the magnetoresistance have been studied for both n- and p-type samples. The observed decrease in the negative magnetoresistance in n-type and enhanced positive magnetoresistance in p-type samples following thermal annealing have been explained by considering thermal annealing-induced improvement of mobility and the crystal quality in N-containing samples. After thermal annealing, the magnitude of negative magnetoresistance decreases and the breaking of the weak localization is achieved at lower magnetic fields in n-type samples. It is observed that as the mobility of the sample increases, critical magnetic field of negative to positive magnetoresistance transition becomes lower.

The effect of sampling rate on observed statistics in a correlated random walk

PubMed Central

Rosser, G.; Fletcher, A. G.; Maini, P. K.; Baker, R. E.

2013-01-01

Tracking the movement of individual cells or animals can provide important information about their motile behaviour, with key examples including migrating birds, foraging mammals and bacterial chemotaxis. In many experimental protocols, observations are recorded with a fixed sampling interval and the continuous underlying motion is approximated as a series of discrete steps. The size of the sampling interval significantly affects the tracking measurements, the statistics computed from observed trajectories, and the inferences drawn. Despite the widespread use of tracking data to investigate motile behaviour, many open questions remain about these effects. We use a correlated random walk model to study the variation with sampling interval of two key quantities of interest: apparent speed and angle change. Two variants of the model are considered, in which reorientations occur instantaneously and with a stationary pause, respectively. We employ stochastic simulations to study the effect of sampling on the distributions of apparent speeds and angle changes, and present novel mathematical analysis in the case of rapid sampling. Our investigation elucidates the complex nature of sampling effects for sampling intervals ranging over many orders of magnitude. Results show that inclusion of a stationary phase significantly alters the observed distributions of both quantities. PMID:23740484

Why weight? Modelling sample and observational level variability improves power in RNA-seq analyses

PubMed Central

Liu, Ruijie; Holik, Aliaksei Z.; Su, Shian; Jansz, Natasha; Chen, Kelan; Leong, Huei San; Blewitt, Marnie E.; Asselin-Labat, Marie-Liesse; Smyth, Gordon K.; Ritchie, Matthew E.

2015-01-01

Variations in sample quality are frequently encountered in small RNA-sequencing experiments, and pose a major challenge in a differential expression analysis. Removal of high variation samples reduces noise, but at a cost of reducing power, thus limiting our ability to detect biologically meaningful changes. Similarly, retaining these samples in the analysis may not reveal any statistically significant changes due to the higher noise level. A compromise is to use all available data, but to down-weight the observations from more variable samples. We describe a statistical approach that facilitates this by modelling heterogeneity at both the sample and observational levels as part of the differential expression analysis. At the sample level this is achieved by fitting a log-linear variance model that includes common sample-specific or group-specific parameters that are shared between genes. The estimated sample variance factors are then converted to weights and combined with observational level weights obtained from the mean–variance relationship of the log-counts-per-million using ‘voom’. A comprehensive analysis involving both simulations and experimental RNA-sequencing data demonstrates that this strategy leads to a universally more powerful analysis and fewer false discoveries when compared to conventional approaches. This methodology has wide application and is implemented in the open-source ‘limma’ package. PMID:25925576

50 CFR 222.404 - Observer program sampling.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Observer program sampling. 222.404 Section 222.404 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS GENERAL ENDANGERED AND THREATENED MARINE SPECIES Observer...

Observing Behavior and Atypically Restricted Stimulus Control

ERIC Educational Resources Information Center

Dube, William V.; Dickson, Chata A.; Balsamo, Lyn M.; O'Donnell, Kristin Lombard; Tomanari, Gerson Y.; Farren, Kevin M.; Wheeler, Emily E.; McIlvane, William J.

2010-01-01

Restricted stimulus control refers to discrimination learning with atypical limitations in the range of controlling stimuli or stimulus features. In the study reported here, 4 normally capable individuals and 10 individuals with intellectual disabilities (ID) performed two-sample delayed matching to sample. Sample-stimulus observing was recorded…

Visual-search model observer for assessing mass detection in CT

NASA Astrophysics Data System (ADS)

Karbaschi, Zohreh; Gifford, Howard C.

2017-03-01

Our aim is to devise model observers (MOs) to evaluate acquisition protocols in medical imaging. To optimize protocols for human observers, an MO must reliably interpret images containing quantum and anatomical noise under aliasing conditions. In this study of sampling parameters for simulated lung CT, the lesion-detection performance of human observers was compared with that of visual-search (VS) observers, a channelized nonprewhitening (CNPW) observer, and a channelized Hoteling (CH) observer. Scans of a mathematical torso phantom modeled single-slice parallel-hole CT with varying numbers of detector pixels and angular projections. Circular lung lesions had a fixed radius. Twodimensional FBP reconstructions were performed. A localization ROC study was conducted with the VS, CNPW and human observers, while the CH observer was applied in a location-known ROC study. Changing the sampling parameters had negligible effect on the CNPW and CH observers, whereas several VS observers demonstrated a sensitivity to sampling artifacts that was in agreement with how the humans performed.

A Unimodal Model for Double Observer Distance Sampling Surveys.

PubMed

Becker, Earl F; Christ, Aaron M

2015-01-01

Distance sampling is a widely used method to estimate animal population size. Most distance sampling models utilize a monotonically decreasing detection function such as a half-normal. Recent advances in distance sampling modeling allow for the incorporation of covariates into the distance model, and the elimination of the assumption of perfect detection at some fixed distance (usually the transect line) with the use of double-observer models. The assumption of full observer independence in the double-observer model is problematic, but can be addressed by using the point independence assumption which assumes there is one distance, the apex of the detection function, where the 2 observers are assumed independent. Aerially collected distance sampling data can have a unimodal shape and have been successfully modeled with a gamma detection function. Covariates in gamma detection models cause the apex of detection to shift depending upon covariate levels, making this model incompatible with the point independence assumption when using double-observer data. This paper reports a unimodal detection model based on a two-piece normal distribution that allows covariates, has only one apex, and is consistent with the point independence assumption when double-observer data are utilized. An aerial line-transect survey of black bears in Alaska illustrate how this method can be applied.

A Numerical Climate Observing Network Design Study

NASA Technical Reports Server (NTRS)

Stammer, Detlef

2003-01-01

This project was concerned with three related questions of an optimal design of a climate observing system: 1. The spatial sampling characteristics required from an ARGO system. 2. The degree to which surface observations from ARGO can be used to calibrate and test satellite remote sensing observations of sea surface salinity (SSS) as it is anticipated now. 3. The more general design of an climate observing system as it is required in the near future for CLIVAR in the Atlantic. An important question in implementing an observing system is that of the sampling density required to observe climate-related variations in the ocean. For that purpose this project was concerned with the sampling requirements for the ARGO float system, but investigated also other elements of a climate observing system. As part of this project we studied the horizontal and vertical sampling characteristics of a global ARGO system which is required to make it fully complementary to altimeter data with the goal to capture climate related variations on large spatial scales (less thanAttachment: 1000 km). We addressed this question in the framework of a numerical model study in the North Atlantic with an 1/6 horizontal resolution. The advantage of a numerical design study is the knowledge of the full model state. Sampled by a synthetic float array, model results will therefore allow to test and improve existing deployment strategies with the goal to make the system as optimal and cost-efficient as possible. Attachment: "Optimal observations for variational data assimilation".

Application of a simple recording system to the analysis of free-play behavior in autistic children1

PubMed Central

Boer, Arend P.

1968-01-01

An observational system, which has been developed to facilitate recording of the total behavioral repertoire of autistic children, involves time-sampling recording of behavior with the help of a common Stenograph machine. Categories which exhausted all behavior were defined. Each category corresponded with a designated key on the Stenograph machine. The observer depressed one key at each 1-sec interval. The observer was paced by audible beats from a metronome. A naive observer can be used with this method. The observer is not mechanically limited and a minimum of observer training is required to obtain reliable measures. The data sampled during a five-week observation period indicated the stability of a taxonomic instrument of behavior based upon direct, time-sampling observations and the stability of spontaneous autistic behavior. Results showed that the behavior of the subjects was largely nonrandom and unsocialized in character. PMID:16795193

Application of a simple recording system to the analysis of free-play behavior in autistic children.

PubMed

Boer, A P

1968-01-01

An observational system, which has been developed to facilitate recording of the total behavioral repertoire of autistic children, involves time-sampling recording of behavior with the help of a common Stenograph machine. Categories which exhausted all behavior were defined. Each category corresponded with a designated key on the Stenograph machine. The observer depressed one key at each 1-sec interval. The observer was paced by audible beats from a metronome. A naive observer can be used with this method. The observer is not mechanically limited and a minimum of observer training is required to obtain reliable measures. The data sampled during a five-week observation period indicated the stability of a taxonomic instrument of behavior based upon direct, time-sampling observations and the stability of spontaneous autistic behavior. Results showed that the behavior of the subjects was largely nonrandom and unsocialized in character.

Observations from a 4-year contamination study of a sample depth profile through Martian meteorite Nakhla.

PubMed

Toporski, Jan; Steele, Andrew

2007-04-01

Morphological, compositional, and biological evidence indicates the presence of numerous well-developed microbial hyphae structures distributed within four different sample splits of the Nakhla meteorite obtained from the British Museum (allocation BM1913,25). By examining depth profiles of the sample splits over time, morphological changes displayed by the structures were documented, as well as changes in their distribution on the samples, observations that indicate growth, decay, and reproduction of individual microorganisms. Biological staining with DNA-specific molecular dyes followed by epifluorescence microscopy showed that the hyphae structures contain DNA. Our observations demonstrate the potential of microbial interaction with extraterrestrial materials, emphasize the need for rapid investigation of Mars return samples as well as any other returned or impactor-delivered extraterrestrial materials, and suggest the identification of appropriate storage conditions that should be followed immediately after samples retrieved from the field are received by a handling/curation facility. The observations are further relevant in planetary protection considerations as they demonstrate that microorganisms may endure and reproduce in extraterrestrial materials over long (at least 4 years) time spans. The combination of microscopy images coupled with compositional and molecular staining techniques is proposed as a valid method for detection of life forms in martian materials as a first-order assessment. Time-resolved in situ observations further allow observation of possible (bio)dynamics within the system.

The role of observer bias in the North American Breeding Bird Survey

USGS Publications Warehouse

Faanes, C.A.; Bystrak, D.

1981-01-01

Ornithologists sampling breeding bird populations are subject to a number of biases in bird recognition and identification. Using Breeding Bird Survey data, these biases are examined qualitatively and quantitatively, and their effects on counts are evaluated. Differences in hearing ability and degree of expertise are the major observer biases considered. Other, more subtle influences are also discussed, including unfamiliar species, resolution, imagination, similar songs and attitude and condition of observers. In most cases, welltrained observers are comparable in ability and their differences contribute little beyond sampling error. However, just as hearing loss can affect results, so can an unprepared observer. These biases are important because they can reduce the credibility of any bird population sampling effort. Care is advised in choosing observers and in interpreting and using results when observers of variable competence are involved.

Statistical scaling of geometric characteristics in stochastically generated pore microstructures

DOE PAGES

Hyman, Jeffrey D.; Guadagnini, Alberto; Winter, C. Larrabee

2015-05-21

In this study, we analyze the statistical scaling of structural attributes of virtual porous microstructures that are stochastically generated by thresholding Gaussian random fields. Characterization of the extent at which randomly generated pore spaces can be considered as representative of a particular rock sample depends on the metrics employed to compare the virtual sample against its physical counterpart. Typically, comparisons against features and/patterns of geometric observables, e.g., porosity and specific surface area, flow-related macroscopic parameters, e.g., permeability, or autocorrelation functions are used to assess the representativeness of a virtual sample, and thereby the quality of the generation method. Here, wemore » rely on manifestations of statistical scaling of geometric observables which were recently observed in real millimeter scale rock samples [13] as additional relevant metrics by which to characterize a virtual sample. We explore the statistical scaling of two geometric observables, namely porosity (Φ) and specific surface area (SSA), of porous microstructures generated using the method of Smolarkiewicz and Winter [42] and Hyman and Winter [22]. Our results suggest that the method can produce virtual pore space samples displaying the symptoms of statistical scaling observed in real rock samples. Order q sample structure functions (statistical moments of absolute increments) of Φ and SSA scale as a power of the separation distance (lag) over a range of lags, and extended self-similarity (linear relationship between log structure functions of successive orders) appears to be an intrinsic property of the generated media. The width of the range of lags where power-law scaling is observed and the Hurst coefficient associated with the variables we consider can be controlled by the generation parameters of the method.« less

SU-E-I-46: Sample-Size Dependence of Model Observers for Estimating Low-Contrast Detection Performance From CT Images

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

Reiser, I; Lu, Z

2014-06-01

Purpose: Recently, task-based assessment of diagnostic CT systems has attracted much attention. Detection task performance can be estimated using human observers, or mathematical observer models. While most models are well established, considerable bias can be introduced when performance is estimated from a limited number of image samples. Thus, the purpose of this work was to assess the effect of sample size on bias and uncertainty of two channelized Hotelling observers and a template-matching observer. Methods: The image data used for this study consisted of 100 signal-present and 100 signal-absent regions-of-interest, which were extracted from CT slices. The experimental conditions includedmore » two signal sizes and five different x-ray beam current settings (mAs). Human observer performance for these images was determined in 2-alternative forced choice experiments. These data were provided by the Mayo clinic in Rochester, MN. Detection performance was estimated from three observer models, including channelized Hotelling observers (CHO) with Gabor or Laguerre-Gauss (LG) channels, and a template-matching observer (TM). Different sample sizes were generated by randomly selecting a subset of image pairs, (N=20,40,60,80). Observer performance was quantified as proportion of correct responses (PC). Bias was quantified as the relative difference of PC for 20 and 80 image pairs. Results: For n=100, all observer models predicted human performance across mAs and signal sizes. Bias was 23% for CHO (Gabor), 7% for CHO (LG), and 3% for TM. The relative standard deviation, σ(PC)/PC at N=20 was highest for the TM observer (11%) and lowest for the CHO (Gabor) observer (5%). Conclusion: In order to make image quality assessment feasible in the clinical practice, a statistically efficient observer model, that can predict performance from few samples, is needed. Our results identified two observer models that may be suited for this task.« less

Recent progresses in outcome-dependent sampling with failure time data.

PubMed

Ding, Jieli; Lu, Tsui-Shan; Cai, Jianwen; Zhou, Haibo

2017-01-01

An outcome-dependent sampling (ODS) design is a retrospective sampling scheme where one observes the primary exposure variables with a probability that depends on the observed value of the outcome variable. When the outcome of interest is failure time, the observed data are often censored. By allowing the selection of the supplemental samples depends on whether the event of interest happens or not and oversampling subjects from the most informative regions, ODS design for the time-to-event data can reduce the cost of the study and improve the efficiency. We review recent progresses and advances in research on ODS designs with failure time data. This includes researches on ODS related designs like case-cohort design, generalized case-cohort design, stratified case-cohort design, general failure-time ODS design, length-biased sampling design and interval sampling design.

Recent progresses in outcome-dependent sampling with failure time data

PubMed Central

Ding, Jieli; Lu, Tsui-Shan; Cai, Jianwen; Zhou, Haibo

2016-01-01

An outcome-dependent sampling (ODS) design is a retrospective sampling scheme where one observes the primary exposure variables with a probability that depends on the observed value of the outcome variable. When the outcome of interest is failure time, the observed data are often censored. By allowing the selection of the supplemental samples depends on whether the event of interest happens or not and oversampling subjects from the most informative regions, ODS design for the time-to-event data can reduce the cost of the study and improve the efficiency. We review recent progresses and advances in research on ODS designs with failure time data. This includes researches on ODS related designs like case–cohort design, generalized case–cohort design, stratified case–cohort design, general failure-time ODS design, length-biased sampling design and interval sampling design. PMID:26759313

Contemporaneous VLBA 5 GHz Observations of Large Area Telescope Detected Blazars

DTIC Science & Technology

2012-01-10

Polarimetry Survey (VIPS) have been included in the sample, as well as 142 sources not found in VIPS. This very large, 5 GHz flux-limited sample of active...observing runs were follow-up observations on 90 sources in the VLBA Imaging and Polarimetry Survey (VIPS; Helmboldt et al. 2007) and new 5 GHz observations...Array (VLBA). In total, 232 sources were observed with the VLBA. Ninety sources that were previously observed as part of the VLBA Imaging and Polarimetry

50 CFR 679.28 - Equipment and operational requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... estimates, vessel monitoring system hardware, catch monitoring and control plan, and catcher vessel... container to store salmon must be located adjacent to the observer sampling station; (ii) All salmon stored in the container must remain in view of the observer at the observer sampling station at all times...

Why weight? Modelling sample and observational level variability improves power in RNA-seq analyses.

PubMed

Liu, Ruijie; Holik, Aliaksei Z; Su, Shian; Jansz, Natasha; Chen, Kelan; Leong, Huei San; Blewitt, Marnie E; Asselin-Labat, Marie-Liesse; Smyth, Gordon K; Ritchie, Matthew E

2015-09-03

Variations in sample quality are frequently encountered in small RNA-sequencing experiments, and pose a major challenge in a differential expression analysis. Removal of high variation samples reduces noise, but at a cost of reducing power, thus limiting our ability to detect biologically meaningful changes. Similarly, retaining these samples in the analysis may not reveal any statistically significant changes due to the higher noise level. A compromise is to use all available data, but to down-weight the observations from more variable samples. We describe a statistical approach that facilitates this by modelling heterogeneity at both the sample and observational levels as part of the differential expression analysis. At the sample level this is achieved by fitting a log-linear variance model that includes common sample-specific or group-specific parameters that are shared between genes. The estimated sample variance factors are then converted to weights and combined with observational level weights obtained from the mean-variance relationship of the log-counts-per-million using 'voom'. A comprehensive analysis involving both simulations and experimental RNA-sequencing data demonstrates that this strategy leads to a universally more powerful analysis and fewer false discoveries when compared to conventional approaches. This methodology has wide application and is implemented in the open-source 'limma' package. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

50 CFR 679.93 - Amendment 80 Program recordkeeping, permits, monitoring, and catch accounting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED... moved to the fish bin. (6) Sample storage. There is sufficient space to accommodate a minimum of 10 observer sampling baskets. This space must be within or adjacent to the observer sample station. (7) Pre...

Influence of Sn on the magnetic ordering of Ni-Sn alloy synthesized using chemical reduction method

NASA Astrophysics Data System (ADS)

Dhanapal, K.; Narayanan, V.; Stephen, A.

2016-05-01

The Ni-Sn alloy was synthesized using borohydride assisted chemical reduction method. The composition of the synthesized alloy was determined using atomic absorption spectroscopy which revealed that the observed composition of Sn is high when compared to the initial composition. The ultrafine particles are clearly observed from field emission scanning electron microscope for all the sample. The X-ray diffraction measurement confirmed that the as-synthesized samples are of amorphous like nature while the samples annealed at 773 K showed crystalline nature. The Fourier transform infrared spectroscopy confirmed metallic bond stretching in the alloy samples. The crystallization and phase transition temperature was observed from differential scanning calorimetry. The shift in the crystallization temperature of Ni with increasing percentage of Sn was observed. The vibrating sample magnetometer was employed to understand the magnetic behavior of the Ni-Sn alloy. As-synthesized alloy samples showed paramagnetic nature while the annealed ones exhibit the soft ferromagnetic, antiferromagnetic and paramagnetic nature. The saturation magnetization value and magnetic ordering in the Ni-Sn alloys depend on the percentage of Sn present in the alloy.

An Hα-selected sample of cataclysmic variables - I. Observations of newly discovered systems

NASA Astrophysics Data System (ADS)

Pretorius, Magaretha L.; Knigge, Christian

2008-04-01

Strong selection effects are present in observational samples of cataclysmic variables (CVs), complicating comparisons to theoretical predictions. The selection criteria used to define most CV samples discriminate heavily against the discovery of short-period, intrinsically faint systems. The situation can be improved by selecting CVs for the presence of emission lines. For this reason, we have constructed a homogeneous sample of CVs selected on the basis of Hα emission. We present discovery observations of the 14 CVs and two additional CV candidates found in this search. The orbital periods of 11 of the new CVs were measured; all are above 3 h. There are two eclipsing systems in the sample, and one in which we observed a quasi-periodic modulation on a ~1000s time-scale. We also detect the secondary star in the spectrum of one system, and measure its spectral type. Several of the new CVs have the spectroscopic appearance of nova-like variables, and a few display what may be SW Sex star behaviour. In a companion paper, we discuss the implications of this new sample for CV evolution.

Hayabusa Re-Entry: Trajectory Analysis and Observation Mission Design

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Winter, Michael W.; Allen, Gary A.; Grinstead, Jay H.; Antimisiaris, Manny E.; Albers, James; Jenniskens, Peter

2011-01-01

On June 13th, 2010, the Hayabusa sample return capsule successfully re-entered Earth s atmosphere over the Woomera Prohibited Area in southern Australia in its quest to return fragments from the asteroid 1998 SF36 Itokawa . The sample return capsule entered at a super-orbital velocity of 12.04 km/sec (inertial), making it the second fastest human-made object to traverse the atmosphere. The NASA DC-8 airborne observatory was utilized as an instrument platform to record the luminous portion of the sample return capsule re-entry (60 sec) with a variety of on-board spectroscopic imaging instruments. The predicted sample return capsule s entry state information at 200 km altitude was propagated through the atmosphere to generate aerothermodynamic and trajectory data used for initial observation flight path design and planning. The DC- 8 flight path was designed by considering safety, optimal sample return capsule viewing geometry and aircraft capabilities in concert with key aerothermodynamic events along the predicted trajectory. Subsequent entry state vector updates provided by the Deep Space Network team at NASA s Jet Propulsion Laboratory were analyzed after the planned trajectory correction maneuvers to further refine the DC-8 observation flight path. Primary and alternate observation flight paths were generated during the mission planning phase which required coordination with Australian authorities for pre-mission approval. The final observation flight path was chosen based upon trade-offs between optimal viewing requirements, ground based observer locations (to facilitate post-flight trajectory reconstruction), predicted weather in the Woomera Prohibited Area and constraints imposed by flight path filing deadlines. To facilitate sample return capsule tracking by the instrument operators, a series of two racetrack flight path patterns were performed prior to the observation leg so the instruments could be pointed towards the region in the star background where the sample return capsule was expected to become visible. An overview of the design methodologies and trade-offs used in the Hayabusa re-entry observation campaign are presented.

Method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein

DOEpatents

Sinha, Dipen N.; Anthony, Brian W.

1997-01-01

A method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries.

Petrographic Analysis of Portland Cement Concrete Cores from Pease Air National Guard Base, New Hampshire

DTIC Science & Technology

2016-11-01

by a white deposit. Carbon- ation staining was observed within the top 2 mm of the sample. The aggre- gates were angular to sub-round ( granitic to...was observed within the top 2 mm of the sample and down surface cracks. The aggre- gates were angular to sub-round ( granitic to gneissic in...Carbona- tion staining was observed within the top 2 mm of the sample. The aggregates were angular to sub-round ( granitic to gneissic in

Genetic characterization of Neotropical Jabiru Storks: Insights for conservation

USGS Publications Warehouse

Lopes, I.F.; Haig, S.M.; Lama, S.N.D.

2010-01-01

Jabiru Stork (Jabiru mycteria is listed under Appendix I of CITES and considered threatened in Central America. The first population genetic analysis of Jabiru Storks was carried out using mitochondrial DNA (mtDNA) control region sequences (520 bp) and five heterologous microsatellite loci. Samples were collected from the field (N = 49) and museum skins (N = 22) in Central (mainly Belize, Nicaragua and Costa Rica) and South America (Colombia, Venezuela, Peru and Brazil). A decline of mtDNA diversity was observed in comparisons between past (N = 20) and present (N = 40) samples collected in Central America and northern South America. Similar levels of microsatellite loci diversity were observed among contemporary samples. Lower levels of mtDNA variability were observed in samples from Central America and northern South America when compared to the Brazilian Pantanal region. Significant levels of genetic differentiation were found between contemporary locations sampled, whereas non-significant results were observed for historic samples. The non-geographic association of haplotypes observed at the cladograms and the recent divergence times estimated between locations are indicative of an evolutionary history of a large population size with limited population structure. Reconnection of populations via increased gene flow, particularly in Central America, is recommended if genetic structure and status are to be restored.

Enhanced cell adhesion on severe peened-plasma nitrided 316L stainless steel

NASA Astrophysics Data System (ADS)

Jayalakshmi, M.; Bhat, Badekai Ramachandra; Bhat, K. Udaya

2018-04-01

Plasma nitriding is an effective technique to enhance the wear resistance of austenitic stainless steels. Recently, severe surface deformation techniques are extensively used prior to nitriding to enhance diffusion kinetics. In the present study, AISI 316L austenitic stainless steel is subjected to peening-nitriding duplex treatment and biocompatibility of treated surfaces is assessed through adhesion of the fibroblast cells. Three-fold increase in the surface microhardness is observed from the un-peened sample to the peened-nitrided sample; with severe peened sample showing intermediate hardness. Similar trend is observed in the number of the fibroblast cells attached to the sample surface. Spreading of some of the fibroblast cells is observed on the sample subjected to duplex treatment; while the other two samples showed only the spindle shaped fibroblasts. Combined influence of surface nanocrystallization and presence of nitride layer is responsible for the improved biocompatibility.

Stability of cannabinoids in urine in three storage temperatures.

PubMed

Golding Fraga, S; Díaz-Flores Estévez, J; Díaz Romero, C

1998-01-01

Stability of cannabinoid compounds in urine samples were evaluated using several storage temperatures. Appreciable losses (> 22.4 percent) were observed in some urine samples, after being stored at room temperature for 10 days. Lower losses (8.1 percent) were observed when the urine samples were refrigerated for 4 weeks. The behavior of urine samples depended on the analyzed urine. This could be due to the different stability of the cannabinoids present in each urine sample. Important losses of 8.0 +/- 10.6, 15.8 +/- 4.2, and 19.6 +/- 6.7 percent were found when the urine samples were frozen during 40 days, 1 year, and 3 years, respectively. Average losses (> > 5 percent) can be observed after one day which could mainly be due to the decrease of the solubility of 11-nor-U9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) or adsorption process of cannabinoid molecules to the plastic storage containers.

Correlated Observations, the Law of Small Numbers and Bank Runs

PubMed Central

2016-01-01

Empirical descriptions and studies suggest that generally depositors observe a sample of previous decisions before deciding if to keep their funds deposited or to withdraw them. These observed decisions may exhibit different degrees of correlation across depositors. In our model depositors decide sequentially and are assumed to follow the law of small numbers in the sense that they believe that a bank run is underway if the number of observed withdrawals in their sample is large. Theoretically, with highly correlated samples and infinite depositors runs occur with certainty, while with random samples it needs not be the case, as for many parameter settings the likelihood of bank runs is zero. We investigate the intermediate cases and find that i) decreasing the correlation and ii) increasing the sample size reduces the likelihood of bank runs, ceteris paribus. Interestingly, the multiplicity of equilibria, a feature of the canonical Diamond-Dybvig model that we use also, disappears almost completely in our setup. Our results have relevant policy implications. PMID:27035435

Deformation of single and multiple laser peened TC6 titanium alloy

NASA Astrophysics Data System (ADS)

Umapathi, A.; Swaroop, S.

2018-03-01

Laser peening without coating (LPwC) was done on the titanium TC6 alloy at a wavelength of 532 nm using an Nd:YAG laser. The laser power densities of 3, 6 and 9 GW cm-2 were used to peen the samples. Samples were also peened multiple times (1, 3 and 5 passes) at 6 GW cm-2. Microhardness showed an overall 23% increase from the baseline value. Further, softening of α phase in the bulk was observed above 6 GW cm-2 in the samples peened once and above 1 pass in multiply peened samples. A similar trend was observed from the residual stress analysis of the samples. The maximum compressive residual stress was -1780 MPa at a depth of 50 μm at 9 GW cm-2. The observed softening of α phase was proposed due to adiabatic heating. Microstructural changes due to adiabatic heating resulting in increased β volume fractions were observed and confirmed by synchrotron radiation measurements.

Correlated Observations, the Law of Small Numbers and Bank Runs.

PubMed

Horváth, Gergely; Kiss, Hubert János

2016-01-01

Empirical descriptions and studies suggest that generally depositors observe a sample of previous decisions before deciding if to keep their funds deposited or to withdraw them. These observed decisions may exhibit different degrees of correlation across depositors. In our model depositors decide sequentially and are assumed to follow the law of small numbers in the sense that they believe that a bank run is underway if the number of observed withdrawals in their sample is large. Theoretically, with highly correlated samples and infinite depositors runs occur with certainty, while with random samples it needs not be the case, as for many parameter settings the likelihood of bank runs is zero. We investigate the intermediate cases and find that i) decreasing the correlation and ii) increasing the sample size reduces the likelihood of bank runs, ceteris paribus. Interestingly, the multiplicity of equilibria, a feature of the canonical Diamond-Dybvig model that we use also, disappears almost completely in our setup. Our results have relevant policy implications.

[Leptospirosis in animal reproduction: III. Role of the hardjo serovar in bovine leptospirosis in Rio de Janeiro, Brazil].

PubMed

Lilenbaum, W; Dos Santos, M R

1995-01-01

Four hundred and five serum samples were drawn from cows with reproductive problems which were not vaccinated against leptospirosis from 21 dairy farms. Three distinct geographic regions were determined and the farms were also classified considering the production system, based on technological, zootechnical and sanitary resources. A total of 277 positive reactions were observed, corresponding to 68.39% of the samples. The predominant serovar was hardjo, reactive on 85 samples (20.98%), predominant on nine farms and observed on 17 farms (80.95%). It was observed the predominance of hardjo in all studied regions and on properties classified as type "A" (22 samples) and type "B" (49 samples). The role of this serovar on bovine leptospirosis in Brazil compared with other countries is discussed.

Fermi Surface Studies and Temperature Dependence of the Electron-Positron Momentum Density in the High Critical Temperature Superconducting Yttrium BARIUM(2) COPPER(3) OXYGEN(7-X) System by Two-Dimensional Acar

NASA Astrophysics Data System (ADS)

von Stetten, Eric Carl

The electron-positron momentum density has been measured by the two dimensional angular correlation of annihilation radiation (2D ACAR) technique for single crystal and polycrystalline (sintered powder) YBa_2 Cu_3O_{7-x} samples. For sintered superconducting and nonsuperconducting samples, the shape and temperature variation of the momentum density was investigated using the high sensitivity 2D ACAR technique. The possible existence of Fermi surfaces (FS's) in the YBa_2Cu _3O_{7-x} system was investigated in high precision 2D ACAR experiments on an oriented (twinned) single crystal superconducting YBa_2Cu _3O_{7-x} (x ~ 0.1) sample, at temperatures above and below the superconducting transition temperature (~85 K). These experiments were performed in the c-axis projection, in order to observe the theoretically predicted cylindrical FS's (if they exist) in a single experiment, without a full reconstruction of the three dimensional momentum density. Large differences were observed between the room temperature 2D ACAR spectra for superconducting and nonsuperconducting sintered powder samples, and smaller differences were observed between the spectra for similarly prepared superconducting samples. For sintered superconducting samples, complex sample dependent temperature variations of the momentum density were observed, in contrast to the small linear temperature variation observed for a sintered powder nonsuperconducting sample. These results are interpreted as manifestations of the theoretically predicted preferential sampling of the linear Cu-O chain region by the positron in the YBa _2Cu_3O _{7-x} system. High precision experiments on the single crystal superconducting sample revealed a nearly isotropic 2D ACAR spectrum, with only four small (~3% of the height at p_{x} = p _{y} = 0) peaks centered along the (110) symmetry lines. A small narrowing of the 2D ACAR spectrum was observed above T_{c}. The Brillouin-zone-reduced momentum density was formed using the "Lock-Crisp-West folding" technique, in order to identify possible FS signatures; several small features were observed that could possibly be due to FS's. A computer study of statistical noise propagation in 2D ACAR data, however, found that the possible FS signatures in the experimental data are similar in shape and magnitude to noise produced features.

Electron Emission Observations from As-Grown and Vacuum-Coated Chemical Vapor Deposited Diamond

NASA Technical Reports Server (NTRS)

Lamouri, A.; Wang, Yaxin; Mearini, G. T.; Krainsky, I. L.; Dayton, J. A., Jr.; Mueller,W.

1996-01-01

Field emission has been observed from chemical vapor deposited diamond grown on Mo and Si substrates. Emission was observed at fields as low as 20 kV/cm. The samples were tested in the as-grown form, and after coating with thin films of Au, CsI, and Ni. The emission current was typically maximum at the onset of the applied field, but was unstable, and decreased rapidly with time from the as-grown films. Thin Au layers, approximately 15 nm thick, vacuum deposited onto the diamond samples significantly improved the stability of the emission current at values approximately equal to those from uncoated samples at the onset of the applied field. Thin layers of CsI, approximately 5 nm thick, were also observed to improve the stability of the emission current but at values less than those from the uncoated samples at the onset of the applied field. While Au and CsI improved the stability of the emission, Ni was observed to have no effect.

In vitro test of external Qigong

PubMed Central

Yount, Garret; Solfvin, Jerry; Moore, Dan; Schlitz, Marilyn; Reading, Melissa; Aldape, Ken; Qian, Yifang

2004-01-01

Background Practitioners of the alternative medical practice 'external Qigong' generally claim the ability to emit or direct "healing energy" to treat patients. We investigated the ability of experienced Qigong practitioners to enhance the healthy growth of cultured human cells in a series of studies, each following a rigorously designed protocol with randomization, blinding and controls for variability. Methods Qigong practitioners directed healing intentionality toward normal brain cell cultures in a basic science laboratory. Qigong treatments were delivered for 20 minutes from a minimum distance of 10 centimeters. Cell proliferation was measured by a standard colony-forming efficiency (CFE) assay and a CFE ratio (CFE for treated samples/CFE for sham samples) was the dependent measure for each experiment. Results During a pilot study (8 experiments), a trend of increased cell proliferation in Qigong-treated samples (CFE Qigong/sham ratios > 1.0) was observed (P = 0.162). In a formal study (28 experiments), a similar trend was observed, with Qigong-treated samples showing on average more colony formation than sham samples (P = 0.036). In a replication study (60 experiments), no significant difference between Qigong-treated samples and sham samples was observed (P = 0.465). Conclusion We observed an apparent increase in the proliferation of cultured cells following external Qigong treatment by practitioners under strictly controlled conditions, but we did not observe this effect in a replication study. These results suggest the need for more controlled and thorough investigation of external Qigong before scientific validation is claimed. PMID:15102336

Method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein

DOEpatents

Sinha, D.N.; Anthony, B.W.

1997-02-25

A method is described for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries. 3 figs.

Visualizing preparation using asymmetrical choline-like ionic liquids for scanning electron microscope observation of non-conductive biological samples.

PubMed

Abe, Shigeaki; Hyono, Atsushi; Kawai, Koji; Yonezawa, Tetsu

2014-03-01

In this study, we investigated conductivity preparation for scanning electron microscope (SEM) observation that used novel asymmetrical choline-type room temperature ionic liquids (RTIL). By immersion in only an RTIL solution, clear SEM images of several types of biological samples were successfully observed. In addition, we could visualize protozoans using RTILs without any dilution. These results suggested that the asymmetrical choline-type RTILs used in this study are suitable for visualizing of biological samples by SEM. Treatment without the need for dilution can obviate the need for adjusting the RTIL concentration and provide for a rapid and easy conductivity treatment for insulating samples.

Surface changes of poly-L-lactic acid due to annealing

NASA Astrophysics Data System (ADS)

Juřík, P.; Michaljaničová, I.; Slepička, P.; Kolskáa, Z.; Švorčík, V.

2017-11-01

Surface modifications are very important part of both current cutting-edge research and modern manufacturing. Our research is focused on poly-L-lactic acid, which is biocompatible and biodegradable polymer that offers applications in modern medicine. We observed morphological changes of the surface of metalized samples due to annealing and studied effect of modifications on total surface area and pore surface and volume. We observed that annealing of non-metalized samples had most pronounced effect up to the 70°C, after which all observed parameters dropped significantly. Metallization has changed behaviour of the samples significantly and resulted in generally lower surface area and porosity when compared to non-metalized samples.

Long Duration Exposure Facility experiment M0003 deintegration observation data base

NASA Technical Reports Server (NTRS)

Gyetvay, S. R.; Coggi, J. M.; Meshishnek, M. J.

1993-01-01

The four trays (2 leading edge and 2 trailing edge) of the M0003 materials experiment on the Long Duration Exposure Facility (LDEF) contained 1274 samples from 20 subexperiments. The complete sample complement represented a broad range of materials, including thin film optical coatings, paints, polymer sheets and tapes, adhesives, and composites, for use in various spacecraft applications, including thermal control, structures, optics, and solar power. Most subexperiments contained sets of samples exposed on both the leading and trailing edge trays of LDEF. Each individual sample was examined by high resolution optical microscope during the deintegration of the subexperiments from the M0003 trays. Observations of the post-flight condition of the samples made during this examination were recorded in a computer data base. The deintegration observation data base is available to requesters on floppy disk in 4th Dimension for the Macintosh format. Over 3,000 color macrographs and photomicrographs were shot to complement the observation records and to document the condition of the individual samples and of the M0003 trays. The photographs provide a visual comparison of the response of materials in leading and trailing edge LDEF environments. The Aerospace Corporate Archives is distributing photographs of the samples and hard copies of the database records to the general public upon request. Information on obtaining copies of the data base disks and for ordering photographs and records of specific samples or materials are given.

A lower occurrence rate of bright X-ray flares in SN-GRBs than z < 1 GRBs: evidence of energy partitions?

NASA Astrophysics Data System (ADS)

Mu, Hui-Jun; Gu, Wei-Min; Mao, Jirong; Liu, Tong; Hou, Shu-Jin; Lin, Da-Bin; Wang, Junfeng; Fang, Taotao; Liang, En-Wei

2018-05-01

The occurrence rates of bright X-ray flares in z < 1 gamma-ray bursts (GRBs) with or without observed supernovae (SNe) association were compared. Our Sample I: the z < 1 long GRBs (LGRBs) with SNe association (SN-GRBs) and with early Swift/X-Ray Telescope (XRT) observations, consists of 18 GRBs, among which only two GRBs have bright X-ray flares. Our Sample II: for comparison, all the z < 1 LGRBs without observed SNe association and with early Swift/XRT observations, consists of 45 GRBs, among which 16 GRBs present bright X-ray flares. Thus, the study indicates a lower occurrence rate of bright X-ray flares in Sample I (11.1%) than in Sample II (35.6%). In addition, if dim X-ray fluctuations are included as flares, then 16.7% of Sample I and 55.6% of Sample II are found to have flares, again showing the discrepancy between these two samples. We examined the physical origin of these bright X-ray flares and found that most of them are probably related to the central engine reactivity. To understand the discrepancy, we propose that such a lower occurrence rate of flares in the SN-GRB sample may hint at an energy partition among the GRB, SNe, and X-ray flares under a saturated energy budget of massive star explosion.

Sparsely sampling the sky: Regular vs. random sampling

NASA Astrophysics Data System (ADS)

Paykari, P.; Pires, S.; Starck, J.-L.; Jaffe, A. H.

2015-09-01

Aims: The next generation of galaxy surveys, aiming to observe millions of galaxies, are expensive both in time and money. This raises questions regarding the optimal investment of this time and money for future surveys. In a previous work, we have shown that a sparse sampling strategy could be a powerful substitute for the - usually favoured - contiguous observation of the sky. In our previous paper, regular sparse sampling was investigated, where the sparse observed patches were regularly distributed on the sky. The regularity of the mask introduces a periodic pattern in the window function, which induces periodic correlations at specific scales. Methods: In this paper, we use a Bayesian experimental design to investigate a "random" sparse sampling approach, where the observed patches are randomly distributed over the total sparsely sampled area. Results: We find that in this setting, the induced correlation is evenly distributed amongst all scales as there is no preferred scale in the window function. Conclusions: This is desirable when we are interested in any specific scale in the galaxy power spectrum, such as the matter-radiation equality scale. As the figure of merit shows, however, there is no preference between regular and random sampling to constrain the overall galaxy power spectrum and the cosmological parameters.

Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography.

PubMed

Trépout, Sylvain; Bastin, Philippe; Marco, Sergio

2017-03-12

This report describes a protocol for preparing thick biological specimens for further observation using a scanning transmission electron microscope. It also describes an imaging method for studying the 3D structure of thick biological specimens by scanning transmission electron tomography. The sample preparation protocol is based on conventional methods in which the sample is fixed using chemical agents, treated with a heavy atom salt contrasting agent, dehydrated in a series of ethanol baths, and embedded in resin. The specific imaging conditions for observing thick samples by scanning transmission electron microscopy are then described. Sections of the sample are observed using a through-focus method involving the collection of several images at various focal planes. This enables the recovery of in-focus information at various heights throughout the sample. This particular collection pattern is performed at each tilt angle during tomography data collection. A single image is then generated, merging the in-focus information from all the different focal planes. A classic tilt-series dataset is then generated. The advantage of the method is that the tilt-series alignment and reconstruction can be performed using standard tools. The collection of through-focal images allows the reconstruction of a 3D volume that contains all of the structural details of the sample in focus.

Optical EVPA rotations in blazars: testing a stochastic variability model with RoboPol data

NASA Astrophysics Data System (ADS)

Kiehlmann, S.; Blinov, D.; Pearson, T. J.; Liodakis, I.

2017-12-01

We identify rotations of the polarization angle in a sample of blazars observed for three seasons with the RoboPol instrument. A simplistic stochastic variability model is tested against this sample of rotation events. The model is capable of producing samples of rotations with parameters similar to the observed ones, but fails to reproduce the polarization fraction at the same time. Even though we can neither accept nor conclusively reject the model, we point out various aspects of the observations that are fully consistent with a random walk process.

Optical gain in 1.3-μm electrically driven dilute nitride VCSOAs

PubMed Central

2014-01-01

We report the observation of room-temperature optical gain at 1.3 μm in electrically driven dilute nitride vertical cavity semiconductor optical amplifiers. The gain is calculated with respect to injected power for samples with and without a confinement aperture. At lower injected powers, a gain of almost 10 dB is observed in both samples. At injection powers over 5 nW, the gain is observed to decrease. For nearly all investigated power levels, the sample with confinement aperture gives slightly higher gain. PMID:24417791

Validation of a Sampling Method to Collect Exposure Data for Central-Line-Associated Bloodstream Infections.

PubMed

Hammami, Naïma; Mertens, Karl; Overholser, Rosanna; Goetghebeur, Els; Catry, Boudewijn; Lambert, Marie-Laurence

2016-05-01

Surveillance of central-line-associated bloodstream infections requires the labor-intensive counting of central-line days (CLDs). This workload could be reduced by sampling. Our objective was to evaluate the accuracy of various sampling strategies in the estimation of CLDs in intensive care units (ICUs) and to establish a set of rules to identify optimal sampling strategies depending on ICU characteristics. Analyses of existing data collected according to the European protocol for patient-based surveillance of ICU-acquired infections in Belgium between 2004 and 2012. CLD data were reported by 56 ICUs in 39 hospitals during 364 trimesters. We compared estimated CLD data obtained from weekly and monthly sampling schemes with the observed exhaustive CLD data over the trimester by assessing the CLD percentage error (ie, observed CLDs - estimated CLDs/observed CLDs). We identified predictors of improved accuracy using linear mixed models. When sampling once per week or 3 times per month, 80% of ICU trimesters had a CLD percentage error within 10%. When sampling twice per week, this was >90% of ICU trimesters. Sampling on Tuesdays provided the best estimations. In the linear mixed model, the observed CLD count was the best predictor for a smaller percentage error. The following sampling strategies provided an estimate within 10% of the actual CLD for 97% of the ICU trimesters with 90% confidence: 3 times per month in an ICU with >650 CLDs per trimester or each Tuesday in an ICU with >480 CLDs per trimester. Sampling of CLDs provides an acceptable alternative to daily collection of CLD data.

Performance Evaluation of Particle Sampling Probes for Emission Measurements of Aircraft Jet Engines

NASA Technical Reports Server (NTRS)

Lee, Poshin; Chen, Da-Ren; Sanders, Terry (Technical Monitor)

2001-01-01

Considerable attention has been recently received on the impact of aircraft-produced aerosols upon the global climate. Sampling particles directly from jet engines has been performed by different research groups in the U.S. and Europe. However, a large variation has been observed among published data on the conversion efficiency and emission indexes of jet engines. The variation results surely from the differences in test engine types, engine operation conditions, and environmental conditions. The other factor that could result in the observed variation is the performance of sampling probes used. Unfortunately, it is often neglected in the jet engine community. Particle losses during the sampling, transport, and dilution processes are often not discussed/considered in literatures. To address this issue, we evaluated the performance of one sampling probe by challenging it with monodisperse particles. A significant performance difference was observed on the sampling probe evaluated under different temperature conditions. Thermophoretic effect, nonisokinetic sampling and turbulence loss contribute to the loss of particles in sampling probes. The results of this study show that particle loss can be dramatic if the sampling probe is not well designed. Further, the result allows ones to recover the actual size distributions emitted from jet engines.

Observed Characteristics and Teacher Quality: Impacts of Sample Selection on a Value Added Model

ERIC Educational Resources Information Center

Winters, Marcus A.; Dixon, Bruce L.; Greene, Jay P.

2012-01-01

We measure the impact of observed teacher characteristics on student math and reading proficiency using a rich dataset from Florida. We expand upon prior work by accounting directly for nonrandom attrition of teachers from the classroom in a sample selection framework. We find evidence that sample selection is present in the estimation of the…

Interval sampling methods and measurement error: a computer simulation.

PubMed

Wirth, Oliver; Slaven, James; Taylor, Matthew A

2014-01-01

A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 2. Toxicity of aircraft and runway deicers.

PubMed

Corsi, S R; Hall, D W; Geis, S W

2001-07-01

Streams receiving runoff from General Mitchell International Airport (GMIA), Milwaukee, Wisconsin, USA, were studied to assess toxic impacts of aircraft and runway deicers. Elevated levels of constituents related to deicing (propylene glycol, ethylene glycol, and ammonia) were observed in stream samples. The LC50s of type I deicer for Ceriodaphnia dubia, Pimephelas promelas, Hyalela azteca, and Chironimus tentans and the EC50 for Microtox were less than 5,000 mg/L of propylene glycol. Concentrations up to 39,000 mg/L were observed at airport outfall sites in samples collected during deicing events. The IC25s of type I deicer for C. dubia and P. promelas were less than 1,500 mg/L of propylene glycol. Concentrations up to 960 mg/L were observed in low-flow samples at an airport outfall site. Measured toxicity of stream water was greatest during winter storms when deicers were applied. Chronic toxicity was observed at airport outfall samples from low-flow periods in the winter and the summer, with the greater toxic impacts from the winter sample. All forms of toxicity in stream-water samples decreased as downstream flows increased.

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 2. Toxicity of aircraft and runway deicer

USGS Publications Warehouse

Corsi, Steven; Hall, David W.; Geis, Steven W.

2001-01-01

Streams receiving runoff from General Mitchell International Airport (GMIA), Milwaukee, Wisconsin, USA, were studied to assess toxic impacts of aircraft and runway deicers. Elevated levels of constituents related to deicing (propylene glycol, ethylene glycol, and ammonia) were observed in stream samples. The LC50s of type I deicer for Ceriodaphnia dubia, Pimephelas promelas, Hyalela azteca, and Chironimus tentans and the EC50 for Microtox® were less than 5,000 mg/L of propylene glycol. Concentrations up to 39,000 mg/L were observed at airport outfall sites in samples collected during deicing events. The IC25s of type I deicer for C. dubia and P. promelas were less than 1,500 mg/L of propylene glycol. Concentrations up to 960 mg/L were observed in low-flow samples at an airport outfall site. Measured toxicity of stream water was greatest during winter storms when deicers were applied. Chronic toxicity was observed at airport outfall samples from low-flow periods in the winter and the summer, with the greater toxic impacts from the winter sample. All forms of toxicity in stream-water samples decreased as downstream flows increased.

A generative inference framework for analysing patterns of cultural change in sparse population data with evidence for fashion trends in LBK culture.

PubMed

Kandler, Anne; Shennan, Stephen

2015-12-06

Cultural change can be quantified by temporal changes in frequency of different cultural artefacts and it is a central question to identify what underlying cultural transmission processes could have caused the observed frequency changes. Observed changes, however, often describe the dynamics in samples of the population of artefacts, whereas transmission processes act on the whole population. Here we develop a modelling framework aimed at addressing this inference problem. To do so, we firstly generate population structures from which the observed sample could have been drawn randomly and then determine theoretical samples at a later time t2 produced under the assumption that changes in frequencies are caused by a specific transmission process. Thereby we also account for the potential effect of time-averaging processes in the generation of the observed sample. Subsequent statistical comparisons (e.g. using Bayesian inference) of the theoretical and observed samples at t2 can establish which processes could have produced the observed frequency data. In this way, we infer underlying transmission processes directly from available data without any equilibrium assumption. We apply this framework to a dataset describing pottery from settlements of some of the first farmers in Europe (the LBK culture) and conclude that the observed frequency dynamic of different types of decorated pottery is consistent with age-dependent selection, a preference for 'young' pottery types which is potentially indicative of fashion trends. © 2015 The Author(s).

The Foundation Supernova Survey: motivation, design, implementation, and first data release

NASA Astrophysics Data System (ADS)

Foley, Ryan J.; Scolnic, Daniel; Rest, Armin; Jha, S. W.; Pan, Y.-C.; Riess, A. G.; Challis, P.; Chambers, K. C.; Coulter, D. A.; Dettman, K. G.; Foley, M. M.; Fox, O. D.; Huber, M. E.; Jones, D. O.; Kilpatrick, C. D.; Kirshner, R. P.; Schultz, A. S. B.; Siebert, M. R.; Flewelling, H. A.; Gibson, B.; Magnier, E. A.; Miller, J. A.; Primak, N.; Smartt, S. J.; Smith, K. W.; Wainscoat, R. J.; Waters, C.; Willman, M.

2018-03-01

The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z ≲ 0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ˜3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111 mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.

Distribution and Fate of Energetics on DoD Test and Training Ranges: Interim Report 5

DTIC Science & Technology

2005-04-01

aluminum, arsenic, and iron were naturally elevated (Ampleman et al. 2003). A cadmium concentration at 0.3 ppb was observed in one sample. Copper...copper concentration was twice the CCME criterion. Iron was also observed in the Shaver River sample at three times the CCME criterion. Concentrations...mainly in C-295, the first site visited. Copper and iron were found at high concentrations in almost all samples; however, only one or two samples showed

Study of the Effect of Temporal Sampling Frequency on DSCOVR Observations Using the GEOS-5 Nature Run Results (Part I): Earths Radiation Budget

NASA Technical Reports Server (NTRS)

Holdaway, Daniel; Yang, Yuekui

2016-01-01

Satellites always sample the Earth-atmosphere system in a finite temporal resolution. This study investigates the effect of sampling frequency on the satellite-derived Earth radiation budget, with the Deep Space Climate Observatory (DSCOVR) as an example. The output from NASA's Goddard Earth Observing System Version 5 (GEOS-5) Nature Run is used as the truth. The Nature Run is a high spatial and temporal resolution atmospheric simulation spanning a two-year period. The effect of temporal resolution on potential DSCOVR observations is assessed by sampling the full Nature Run data with 1-h to 24-h frequencies. The uncertainty associated with a given sampling frequency is measured by computing means over daily, monthly, seasonal and annual intervals and determining the spread across different possible starting points. The skill with which a particular sampling frequency captures the structure of the full time series is measured using correlations and normalized errors. Results show that higher sampling frequency gives more information and less uncertainty in the derived radiation budget. A sampling frequency coarser than every 4 h results in significant error. Correlations between true and sampled time series also decrease more rapidly for a sampling frequency less than 4 h.

Implanted Deuterium Retention and Release in Carbon-Coated Beryllium

NASA Astrophysics Data System (ADS)

Anderl, R. A.; Longhurst, G. R.; Pawelko, R. J.; Oates, M. A.

1997-06-01

Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Å. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Å revealed that exposure to a temperature of 400°C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400°C and an incident deuterium flux of approximately 6 × 1019 D/m2-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples.

Sampling animal sign in heterogeneous environments: how much is enough?

USGS Publications Warehouse

Holbrook, Joseph D.; Arkle, Robert S.; Rachlow, Janet L.; Vierling, Kerri T.; Pilliod, David S.

2015-01-01

Animal ecologists often use animal sign as a surrogate for direct observation of organisms, especially when species are secretive or difficult to observe. Spatial heterogeneity in arid environments makes it challenging to consistently detect and precisely characterize animal sign, which can bias estimates of animal abundance or habitat use. Piute ground squirrels (Urocitellus mollis) and Owyhee harvester ants (Pogonomyrmex salinus) live in arid environments and are fossorial, which can make them difficult to observe directly. Their relative abundance can be assessed using sign (i.e., burrows and nests). We implemented an over-sampling framework (i.e., recorded an excessive amount of information) with two observers to 1) identify a sampling intensity that balanced precision with our resource constraints, and 2) assess classification and detection of squirrel burrows and ant nests across vegetation conditions. We sampled 20 1-ha plots for ground squirrel burrows and ant nests using six 4 m × 100 m belt transects. Analyses of precision and sampling effort indicated that three belt transects covering 1200 m2 per ha provided sufficient precision, while minimizing effort. Regardless of vegetation conditions, counts by two observers were strongly correlated for ground squirrel burrows (r = 0.99, P < 0.001, df = 18; slope = 0.92) and harvester ant nests (r = 0.99, P < 0.001, df = 18; slope = 1.01) indicating observer consistency and perhaps high detection probability. These findings illustrate an approach for evaluating sampling designs in many ecological contexts.

Validation of spot-testing kits to determine iodine content in salt.

PubMed Central

Pandav, C. S.; Arora, N. K.; Krishnan, A.; Sankar, R.; Pandav, S.; Karmarkar, M. G.

2000-01-01

Iodine deficiency disorders are a major public health problem, and salt iodization is the most widely practised intervention for their elimination. For the intervention to be successful and sustainable, it is vital to monitor the iodine content of salt regularly. Iodometric titration, the traditional method for measuring iodine content, has problems related to accessibility and cost. The newer spot-testing kits are inexpensive, require minimal training, and provide immediate results. Using data from surveys to assess the availability of iodized salt in two states in India, Madhya Pradesh and the National Capital Territory of Delhi, we tested the suitability of such a kit in field situations. Salt samples from Delhi were collected from 30 schools, chosen using the Expanded Programme on Immunization (EPI) cluster sampling technique. A single observer made the measurement for iodine content using the kit. Salt samples from Madhya Pradesh were from 30 rural and 30 urban clusters, identified by using census data and the EPI cluster sampling technique. In each cluster, salt samples were collected from 10 randomly selected households and all retailers. The 15 investigators performing the survey estimated the iodine content of salt samples in the field using the kit. All the samples were brought to the central laboratory in Delhi, where iodine content was estimated using iodometric titration as a reference method. The agreement between the kit and titration values decreased as the number of observers increased. Although sensitivity was not much affected by the increase in the number of observers (93.3% for a single observer and 93.9% for multiple observers), specificity decreased sharply (90.4% for a single observer and 40.4% for multiple observers). Due to the low specificity and resulting high numbers of false-positives for the kit when used by multiple observers ("real-life situations"), kits were likely to consistently overestimate the availability of iodized salt. This overestimation could result in complacency. Therefore, we conclude that until a valid alternative is available, the titration method should be used for monitoring the iodine content of salt at all levels, from producer to consumer, to ensure effectiveness of the programme. PMID:10994281

Desizing of Starch Containing Cotton Fabrics Using Near Atmospheric Pressure, Cold DC Plasma Treatment

NASA Astrophysics Data System (ADS)

Prasath, A.; Sivaram, S. S.; Vijay Anand, V. D.; Dhandapani, Saravanan

2013-03-01

An attempt has been made to desize the starch containing grey cotton fabrics using the DC plasma with oxygen as the gaseous medium. Process conditions of the plasma reactor were optimized in terms of distance between the plates (3.2 cm), applied voltage (600 V) and applied pressure (0.01 bar) to obtain maximum desizing efficiency. No discolouration was observed in the hot water extracts of the desized sample in presence of iodine though relatively higher solvent extractable impurities (4.53 %) were observed in the plasma desized samples compared to acid desized samples (3.38 %). Also, significant weight loss, improvements in plasma desized samples were observed than that of grey fabrics in terms of drop absorbency.

Microstructural Characteristics of High Rate Plastic Deformation in Elektron™ WE43 Magnesium Alloy

NASA Astrophysics Data System (ADS)

Hamilton, Joseph; Brennan, Sarah T.; Sohn, Yongho; Davis, Bruce; DeLorme, Rick; Cho, Kyu

High strain rate deformation of WE43 magnesium alloy was carried out by high velocity impacts, and the characteristics and mechanisms of microstructural damage were examined. Six samples were subjected to a variety of high velocity impact loadings that resulted in both partial and full damage. Optical, scanning and transmission electron microscopy analyses were performed in order to identify regions of shear localization. These regions were used to map, both quantitatively and qualitatively, the effects of deformation on the microstructure. Shear localization was observed in every sample, and its depth was measured. Evidence of shear localization was observed to a greater extent in samples with partial damage while fracturing was observed more frequently in samples with full damage.

Observation of Persistent Currents in Finely Dispersed Pyrolytic Graphite

NASA Astrophysics Data System (ADS)

Saad, M.; Gilmutdinov, I. F.; Kiiamov, A. G.; Tayurskii, D. A.; Nikitin, S. I.; Yusupov, R. V.

2018-01-01

The trapped magnetic flux in the finely ground pyrolytic graphite sample annealed at 670 K in air has been observed. Flux trapping occurs on cooling of the sample from room temperature to 10 K in a magnetic field of 1 T. The magnitude and sign of the induced trapped moment remain unchanged when the applied magnetic field is varied within ±1 T at T K. The trapped magnetic flux is manifested in the displacement of the magnetization curve relative to that of the sample cooled in zero field. Displacement magnitude gradually decreases with the temperature increase up to 350 K, not reaching zero. The set of experimental observations probably reflects the presence in the sample of a granular high-temperature superconducting phase.

Hydraulic considerations in sampling the unsaturated zone with inclined gravity lysimeters

USGS Publications Warehouse

Oaksford, E.T.

1983-01-01

Inclined gravity lysimeters as deep as 5.39 meters below land surface designed for sampling soil water in coarse sand under continuous ponding conditions, were shown to be capable of collecting 10 liters per hour at an infiltration rate of 0.5 meter per hour. This represents a capture efficiency of approximately 50%, a value observed in two similar but shallower lysimeters. When lysimeters are installed from a trench or observation manhole, soil-water samples can be taken under virtually undisturbed conditions, avoiding the soil disturbance and filtration associated with porous-cup vacuum lysimeters. Successful operation requires that the sampler be designed for the hydraulic characteristics of the soil from which the water sample is to be extracted. Criteria for lysimeter dimensions can be established on the basis of pressure heads experienced during sampling, can be induced to flow into the lysimeter by gradient manipulation. Observed head gradients outside the lysimeter ranged between 1.7 and 2.2 times those across the lysimeter, which would seem to explain the observed capture efficiency. (USGS)

Chemical Analysis of Suspected Unrecorded Alcoholic Beverages from the States of São Paulo and Minas Gerais, Brazil

PubMed Central

Soares Neto, Julino Assunção Rodrigues

2015-01-01

Our study analyzed 152 samples of alcoholic beverages collected from the states of São Paulo and Minas Gerais, Brazil, using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), and inductively coupled plasma atomic emission spectrometry (ICP-AES). The methanol content varied from 20 to 180 ppm in 28 samples, and the limit of the accepted level of 200 ppm was exceeded in only one sample. High content of cyanide derivatives and ethyl carbamate, above the accepted level of 150 ppb, was observed in 109 samples. Carbonyl compounds were also observed in 111 samples, showing hydroxy 2-propanone, 4-methyl-4-hepten-3-one, furfural, and 2-hydroxyethylcarbamate as main constituents. Copper was found at concentrations above 5 ppm in 26 samples; the maximum value observed was 28 ppm. This work evaluated the human health risk associated with the poor quality of suspected unrecorded alcohols beverages. PMID:26495155

Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

NASA Astrophysics Data System (ADS)

Zhang, Min; Wei, Zhan-Tao

2018-05-01

Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

Observation of asphalt binder microstructure with ESEM.

PubMed

Mikhailenko, P; Kadhim, H; Baaj, H; Tighe, S

2017-09-01

The observation of asphalt binder with the environmental scanning electron microscope (ESEM) has shown the potential to observe asphalt binder microstructure and its evolution with binder aging. A procedure for the induction and identification of the microstructure in asphalt binder was established in this study and included sample preparation and observation parameters. A suitable heat-sampling asphalt binder sample preparation method was determined for the test and several stainless steel and Teflon sample moulds developed, finding that stainless steel was the preferable material. The magnification and ESEM settings conducive to observing the 3D microstructure were determined through a number of observations to be 1000×, although other magnifications could be considered. Both straight run binder (PG 58-28) and an air blown oxidised binder were analysed; their structures being compared for their relative size, abundance and other characteristics, showing a clear evolution in the fibril microstructure. The microstructure took longer to appear for the oxidised binder. It was confirmed that the fibril microstructure corresponded to actual characteristics in the asphalt binder. Additionally, a 'bee' micelle structure was found as a transitional structure in ESEM observation. The test methods in this study will be used for more comprehensive analysis of asphalt binder microstructure. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Estimation of time-series properties of gourd observed solar irradiance data using cloud properties derived from satellite observations

NASA Astrophysics Data System (ADS)

Watanabe, T.; Nohara, D.

2017-12-01

The shorter temporal scale variation in the downward solar irradiance at the ground level (DSI) is not understood well because researches in the shorter-scale variation in the DSI is based on the ground observation and ground observation stations are located coarsely. Use of dataset derived from satellite observation will overcome such defect. DSI data and MODIS cloud properties product are analyzed simultaneously. Three metrics: mean, standard deviation and sample entropy, are used to evaluate time-series properties of the DSI. Three metrics are computed from two-hours time-series centered at the observation time of MODIS over the ground observation stations. We apply the regression methods to design prediction models of each three metrics from cloud properties. The validation of the model accuracy show that mean and standard deviation are predicted with a higher degree of accuracy and that the accuracy of prediction of sample entropy, which represents the complexity of time-series, is not high. One of causes of lower prediction skill of sample entropy is the resolution of the MODIS cloud properties. Higher sample entropy is corresponding to the rapid fluctuation, which is caused by the small and unordered cloud. It seems that such clouds isn't retrieved well.

The Atmospheric Scanning Electron Microscope with open sample space observes dynamic phenomena in liquid or gas.

PubMed

Suga, Mitsuo; Nishiyama, Hidetoshi; Konyuba, Yuji; Iwamatsu, Shinnosuke; Watanabe, Yoshiyuki; Yoshiura, Chie; Ueda, Takumi; Sato, Chikara

2011-12-01

Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields. Copyright © 2011 Elsevier B.V. All rights reserved.

Development of Creative Behavior Observation Form: A Study on Validity and Reliability

ERIC Educational Resources Information Center

Dere, Zeynep; Ömeroglu, Esra

2018-01-01

This study, Creative Behavior Observation Form was developed to assess creativity of the children. While the study group on the reliability and validity of Creative Behavior Observation Form was being developed, 257 children in total who were at the ages of 5-6 were used as samples with stratified sampling method. Content Validity Index (CVI) and…

Spatial distributions and seasonal variations of organochlorine pesticides in water and soil samples in Bolu, Turkey.

PubMed

Karadeniz, Hatice; Yenisoy-Karakaş, Serpil

2015-03-01

In this study, a total of 75 water samples (38 groundwater and 37 surface water samples) and 54 surface soil samples were collected from the five districts of Bolu, which is located in the Western Black Sea Region of Turkey in the summer season of 2009. In the autumn season, 17 water samples (surface water and groundwater samples) and 17 soil samples were collected within the city center to observe the seasonal changes of organochlorine pesticides (OCPs). Groundwater and surface water samples were extracted using solid phase extraction. Soil samples were extracted ultrasonically. Sixteen OCP compounds in the standard solution were detected by a gas chromatography-electron capture detector (GC-ECD). Therefore, the method validation was performed for those 16 OCP compounds. However, 13 OCP compounds could be observed in the samples. The concentrations of most OCPs were higher in samples collected in the summer than those in the autumn. The most frequently observed pesticides were endosulfan sulfate and 4,4'-dichlorodiphenyltrichloroethane (DDT) in groundwater samples, α-HCH in surface water samples, and endosulfan sulfate in soil samples. The average concentration of endosulfan sulfate was the highest in water and soil samples. Compared to the literature values, the average concentrations in this study were lower values. Spatial distribution of OCPs was evaluated with the aid of contour maps for the five districts of Bolu. Generally, agricultural processes affected the water and soil quality in the region. However, non-agricultural areas were also affected by pesticides. The concentrations of pesticides were below the legal limits of European directives for each pesticide.

Development of scanning electron and x-ray microscope

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

Matsumura, Tomokazu, E-mail: tomokzau.matsumura@etd.hpk.co.jp; Hirano, Tomohiko, E-mail: tomohiko.hirano@etd.hpk.co.jp; Suyama, Motohiro, E-mail: suyama@etd.hpk.co.jp

We have developed a new type of microscope possessing a unique feature of observing both scanning electron and X-ray images under one unit. Unlike former X-ray microscopes using SEM [1, 2], this scanning electron and X-ray (SELX) microscope has a sample in vacuum, thus it enables one to observe a surface structure of a sample by SEM mode, to search the region of interest, and to observe an X-ray image which transmits the region. For the X-ray observation, we have been focusing on the soft X-ray region from 280 eV to 3 keV to observe some bio samples and softmore » materials. The resolutions of SEM and X-ray modes are 50 nm and 100 nm, respectively, at the electron energy of 7 keV.« less

Quantitative and qualitative measure of intralaboratory two-dimensional protein gel reproducibility and the effects of sample preparation, sample load, and image analysis.

PubMed

Choe, Leila H; Lee, Kelvin H

2003-10-01

We investigate one approach to assess the quantitative variability in two-dimensional gel electrophoresis (2-DE) separations based on gel-to-gel variability, sample preparation variability, sample load differences, and the effect of automation on image analysis. We observe that 95% of spots present in three out of four replicate gels exhibit less than a 0.52 coefficient of variation (CV) in fluorescent stain intensity (% volume) for a single sample run on multiple gels. When four parallel sample preparations are performed, this value increases to 0.57. We do not observe any significant change in quantitative value for an increase or decrease in sample load of 30% when using appropriate image analysis variables. Increasing use of automation, while necessary in modern 2-DE experiments, does change the observed level of quantitative and qualitative variability among replicate gels. The number of spots that change qualitatively for a single sample run in parallel varies from a CV = 0.03 for fully manual analysis to CV = 0.20 for a fully automated analysis. We present a systematic method by which a single laboratory can measure gel-to-gel variability using only three gel runs.

Effect of structural modification on second harmonic generation in collagen

NASA Astrophysics Data System (ADS)

Stoller, Patrick C.; Reiser, Karen M.; Celliers, Peter M.; Rubenchik, Alexander M.

2003-07-01

The effects of structural perturbation on second harmonic generation in collagen were investigated. Type I collagen fascicles obtained from rat tails were structurally modified by increasing nonenzymatic cross-linking, by thermal denaturation, by collagenase digestion, or by dehydration. Changes in polarization dependence were observed in the dehydrated samples. Surprisingly, no changes in polarization dependence were observed in highly crosslinked samples, despite significant alterations in packing structure. Complete thermal denaturation and collagenase digestion produced samples with no detectable second harmonic signal. Prior to loss of signal, no change in polarization dependence was observed in partially heated or digested collagen.

Microbiome Heterogeneity Characterizing Intestinal Tissue and Inflammatory Bowel Disease Phenotype.

PubMed

Tyler, Andrea D; Kirsch, Richard; Milgrom, Raquel; Stempak, Joanne M; Kabakchiev, Boyko; Silverberg, Mark S

2016-04-01

Inflammatory bowel disease has been associated with differential abundance of numerous organisms when compared to healthy controls (HCs); however, few studies have investigated variability in the microbiome across intestinal locations and how this variability might be related to disease location and phenotype. In this study, we have analyzed the microbiome of a large cohort of individuals recruited at Mount Sinai Hospital in Toronto, Canada. Biopsies were taken from subjects with Crohn's disease, ulcerative colitis, and HC, and also individuals having undergone ileal pouch-anal anastomosis for treatment of ulcerative colitis or familial adenomatous polyposis. Microbial 16S rRNA was sequenced using the Illumina MiSeq platform. We observed a great deal of variability in the microbiome characterizing different sampling locations. Samples from pouch and afferent limb were comparable in microbial composition. When comparing sigmoid and terminal ileum samples, more differences were observed. The greatest number of differentially abundant microbes was observed when comparing either pouch or afferent limb samples to sigmoid or terminal ileum. Despite these differences, we were able to observe modest microbial variability between inflammatory bowel disease phenotypes and HCs, even when controlling for sampling location and additional experimental factors. Most detected associations were observed between HCs and Crohn's disease, with decreases in specific genera in the families Ruminococcaceae and Lachnospiraceae characterizing tissue samples from individuals with Crohn's disease. This study highlights important considerations when analyzing the composition of the microbiome and also provides useful insight into differences in the microbiome characterizing these seemingly related phenotypes.

Improved DESI-MS Performance using Edge Sampling and aRotational Sample Stage

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

Kertesz, Vilmos; Van Berkel, Gary J

2008-01-01

The position of the surface to be analyzed relative to the sampling orifice or capillary into the mass spectrometer has been known to dramatically affect the observed signal levels in desorption electrospray ionization mass spectrometry (DESIMS). In analyses of sample spots on planar surfaces, DESI-MS signal intensities as much as five times greater were routinely observed when the bottom of the sampling capillary was appropriately positioned beneath the surface plane ( edge sampling") compared to when the capillary just touched the surface. To take advantage of the optimum "edge sampling" geometry and to maximize the number of samples that couldmore » be analyzed in this configuration, a rotational sample stage was integrated into a typical DESI-MS setup. The rapid quantitative determination of caffeine in two diet sport drinks (Diet Turbo Tea, Speed Stack Grape) spiked with an isotopically labeled internal standard demonstrated the utility of this approach.« less

Cluster designs to assess the prevalence of acute malnutrition by lot quality assurance sampling: a validation study by computer simulation.

PubMed

Olives, Casey; Pagano, Marcello; Deitchler, Megan; Hedt, Bethany L; Egge, Kari; Valadez, Joseph J

2009-04-01

Traditional lot quality assurance sampling (LQAS) methods require simple random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67x3 (67 clusters of three observations) and a 33x6 (33 clusters of six observations) sampling scheme to assess the prevalence of global acute malnutrition (GAM). Further, we explore the use of a 67x3 sequential sampling scheme for LQAS classification of GAM prevalence. Results indicate that, for independent clusters with moderate intracluster correlation for the GAM outcome, the three sampling designs maintain approximate validity for LQAS analysis. Sequential sampling can substantially reduce the average sample size that is required for data collection. The presence of intercluster correlation can impact dramatically the classification error that is associated with LQAS analysis.

The effects of nucleation and solidification mechanisms on the microstructure and thermomechanical response of tin silver copper solder joints

NASA Astrophysics Data System (ADS)

Arfaei, Babak

This work examines the nucleation mechanism of Sn in SnAgCu alloys and its effect on the microstructure of those solder joints. The nucleation rate of Sn in a SAC alloy was obtained by simultaneous calorimetric examination of the isothermal solidification of 88 flip chip Sn-Ag-Cu solder joints. Qualitative agreement with classic nucleation theory was observed, although it was concluded that the spherical cap model cannot be applied to explain the structure of nucleus. It was shown that the solidification temperature significantly affects the microstructure; samples that undercooled less than approximately 40oC revealed one or three large Sn grains, while interlaced twinning was observed in the samples that solidified at lower temperatures. In order to better understand the effect of microstructure on the thermomechanical properties of solder joints, a study of the dependence of room temperature shear fatigue lifetime on Sn grain number and orientation was conducted. This study examined the correlations of variations in fatigue life of solder balls with the microstructure of Sn-Ag-Cu solder. The mean fatigue lifetime was found to be significantly longer for samples with multiple Sn grains than for samples with single Sn grains. For single grain samples, correlations between Sn grain orientation (with respect to the loading direction) and lifetime were observed, providing insight on early failures in SnAgCu solder joints. Correlations between the lifetimes of single Sn grained, SAC205 solder joints with differences in Ag3Sn and Cu6Sn5 precipitate microstructures were investigated. It was found that Ag3Sn precipitates were highly segregated from Cu6Sn 5 precipitates on a length scale of approximately twenty microns. Furthermore, large (factor of two) variations of the Sn dendrite arm size were observed within given samples. Such variations in values of dendrite arm size within a single sample were much larger than observed variations of this parameter between individual samples. Few significant differences were observed in the average size of precipitates in different samples. While the earliest and latest lifetimes of single Sn grained samples were correlated with Sn grain orientation, effects of precipitate microstructure on lifetimes were not clearly delineated.

Micro-organism distribution sampling for bioassays

NASA Technical Reports Server (NTRS)

Nelson, B. A.

1975-01-01

Purpose of sampling distribution is to characterize sample-to-sample variation so statistical tests may be applied, to estimate error due to sampling (confidence limits) and to evaluate observed differences between samples. Distribution could be used for bioassays taken in hospitals, breweries, food-processing plants, and pharmaceutical plants.

Predicting Student Achievement in University-Level Business and Economics Classes: Peer Observation of Classroom Instruction and Student Ratings of Teaching Effectiveness

ERIC Educational Resources Information Center

Galbraith, Craig S.; Merrill, Gregory B.

2012-01-01

We examine the validity of peer observation of classroom instruction for purposes of faculty evaluation. Using both a multi-section course sample and a sample of different courses across a university's School of Business and Economics we find that the results of annual classroom observations of faculty teaching are significantly and positively…

Carbon Monitoring System Flux Estimation and Attribution: Impact of ACOS-GOSAT X(CO2) Sampling on the Inference of Terrestrial Biospheric Sources and Sinks

NASA Technical Reports Server (NTRS)

Liu, Junjie; Bowman, Kevin W.; Lee, Memong; Henze, David K.; Bousserez, Nicolas; Brix, Holger; Collatz, G. James; Menemenlis, Dimitris; Ott, Lesley; Pawson, Steven;

Melissopalynological Characterization of North Algerian Honeys.

PubMed

Nair, Samira; Meddah, Boumedienne; Aoues, Abdelkader

2013-03-07

A pollen analysis of Algerian honey was conducted on a total of 10 honey samples. The samples were prepared using the methodology described by Louveaux et al ., that was then further adapted by Ohe et al . The samples were subsequently observed using light microscopy. A total of 36 pollen taxa were discovered and could be identified in the analyzed honey samples. Seventy percent of the studied samples belonged to the group ofmonofloral honeys represented by Eucalyptus globulus , Thymus vulgaris , Citrus sp. and Lavandula angustifolia . Multifloral honeys comprised 30% of the honey samples, with pollen grains of Lavandula stoechas (28.49%) standing out as the most prevalent. Based on cluster analysis, two different groups of honey were observed according to different pollen types found in the samples. The identified pollen spectrum of honey confirmed their botanical origin.

Galaxy redshift surveys with sparse sampling

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

Chiang, Chi-Ting; Wullstein, Philipp; Komatsu, Eiichiro

2013-12-01

Survey observations of the three-dimensional locations of galaxies are a powerful approach to measure the distribution of matter in the universe, which can be used to learn about the nature of dark energy, physics of inflation, neutrino masses, etc. A competitive survey, however, requires a large volume (e.g., V{sub survey} ∼ 10Gpc{sup 3}) to be covered, and thus tends to be expensive. A ''sparse sampling'' method offers a more affordable solution to this problem: within a survey footprint covering a given survey volume, V{sub survey}, we observe only a fraction of the volume. The distribution of observed regions should bemore » chosen such that their separation is smaller than the length scale corresponding to the wavenumber of interest. Then one can recover the power spectrum of galaxies with precision expected for a survey covering a volume of V{sub survey} (rather than the volume of the sum of observed regions) with the number density of galaxies given by the total number of observed galaxies divided by V{sub survey} (rather than the number density of galaxies within an observed region). We find that regularly-spaced sampling yields an unbiased power spectrum with no window function effect, and deviations from regularly-spaced sampling, which are unavoidable in realistic surveys, introduce calculable window function effects and increase the uncertainties of the recovered power spectrum. On the other hand, we show that the two-point correlation function (pair counting) is not affected by sparse sampling. While we discuss the sparse sampling method within the context of the forthcoming Hobby-Eberly Telescope Dark Energy Experiment, the method is general and can be applied to other galaxy surveys.« less

Qualitative Analysis of E-Liquid Emissions as a Function of Flavor Additives Using Two Aerosol Capture Methods.

PubMed

Eddingsaas, Nathan; Pagano, Todd; Cummings, Cody; Rahman, Irfan; Robinson, Risa; Hensel, Edward

2018-02-13

This work investigates emissions sampling methods employed for qualitative identification of compounds in e-liquids and their resultant aerosols to assess what capture methods may be sufficient to identify harmful and potentially harmful constituents present. Three popular e-liquid flavors (cinnamon, mango, vanilla) were analyzed using qualitative gas chromatography-mass spectrometry (GC-MS) in the un-puffed state. Each liquid was also machine-puffed under realistic-use flow rate conditions and emissions were captured using two techniques: filter pads and methanol impingers. GC-MS analysis was conducted on the emissions captured using both techniques from all three e-liquids. The e-liquid GC-MS analysis resulted in positive identification of 13 compounds from the cinnamon flavor e-liquid, 31 from mango, and 19 from vanilla, including a number of compounds observed in all e-liquid experiments. Nineteen compounds were observed in emissions which were not present in the un-puffed e-liquid. Qualitative GC-MS analysis of the emissions samples identify compounds observed in all three samples: e-liquid, impinge, and filter pads, and each subset thereof. A limited number of compounds were observed in emissions captured with impingers, but were not observed in emissions captured using filter pads; a larger number of compounds were observed on emissions collected from the filter pads, but not those captured with impingers. It is demonstrated that sampling methods have different sampling efficiencies and some compounds might be missed using only one method. It is recommended to investigate filter pads, impingers, thermal desorption tubes, and solvent extraction resins to establish robust sampling methods for emissions testing of e-cigarette emissions.

Qualitative Analysis of E-Liquid Emissions as a Function of Flavor Additives Using Two Aerosol Capture Methods

PubMed Central

Eddingsaas, Nathan; Pagano, Todd; Cummings, Cody; Rahman, Irfan; Robinson, Risa

2018-01-01

This work investigates emissions sampling methods employed for qualitative identification of compounds in e-liquids and their resultant aerosols to assess what capture methods may be sufficient to identify harmful and potentially harmful constituents present. Three popular e-liquid flavors (cinnamon, mango, vanilla) were analyzed using qualitative gas chromatography-mass spectrometry (GC-MS) in the un-puffed state. Each liquid was also machine-puffed under realistic-use flow rate conditions and emissions were captured using two techniques: filter pads and methanol impingers. GC-MS analysis was conducted on the emissions captured using both techniques from all three e-liquids. The e-liquid GC-MS analysis resulted in positive identification of 13 compounds from the cinnamon flavor e-liquid, 31 from mango, and 19 from vanilla, including a number of compounds observed in all e-liquid experiments. Nineteen compounds were observed in emissions which were not present in the un-puffed e-liquid. Qualitative GC-MS analysis of the emissions samples identify compounds observed in all three samples: e-liquid, impinge, and filter pads, and each subset thereof. A limited number of compounds were observed in emissions captured with impingers, but were not observed in emissions captured using filter pads; a larger number of compounds were observed on emissions collected from the filter pads, but not those captured with impingers. It is demonstrated that sampling methods have different sampling efficiencies and some compounds might be missed using only one method. It is recommended to investigate filter pads, impingers, thermal desorption tubes, and solvent extraction resins to establish robust sampling methods for emissions testing of e-cigarette emissions. PMID:29438289

A study of atmospheric mixing of trace gases by aerial sampling with a multi-rotor drone

NASA Astrophysics Data System (ADS)

Chang, Chih-Chung; Chang, Chih-Yuan; Wang, Jia-Lin; Lin, Ming-Ren; Ou-Yang, Chang-Feng; Pan, Hsiang-Hsu; Chen, Yen-Chen

2018-07-01

We exploited a novel sampling vehicle, a multi-rotor drone carrying a remote-controlled whole air sampling device, to collect aerial samples with high sample integrity and preservation conditions. An array of 106 volatile organic compounds (VOCs), CO, CH4, and CO2 were analyzed and compared between the aerial samples (300-m height) and the ground-level samples in pairs to inspect for vertical mixing of the trace gases at a coastal site under three different meteorological conditions of local circulation, frontal passage, and high-pressure peripheral circulation. A rather homogeneous composition was observed for the sample pairs immediately after the frontal passage, indicating a well-mixed condition below 300 m. In contrast, inhomogeneous mixing was observed for the sample pairs under the other two conditions (local circulation and high-pressure peripheral circulation), suggesting different layers of air masses. Furthermore, information of unique source markers, composition profiles, and lifetimes of compounds were used to differentiate the origins of the air masses aloft and at the surface to substantiate the observed inhomogeneity. The study demonstrates that, with the availability of the near-surface aerial sampling coupling with in-laboratory analysis, detailed compositions of trace gases can now be readily obtained with superior data quality. Based on the distinctive chemical compositions, the sources, transport, and atmospheric mixing of the airborne pollutants in the near-surface atmosphere can be better studied and understood.

Multi-rate cubature Kalman filter based data fusion method with residual compensation to adapt to sampling rate discrepancy in attitude measurement system.

PubMed

Guo, Xiaoting; Sun, Changku; Wang, Peng

2017-08-01

This paper investigates the multi-rate inertial and vision data fusion problem in nonlinear attitude measurement systems, where the sampling rate of the inertial sensor is much faster than that of the vision sensor. To fully exploit the high frequency inertial data and obtain favorable fusion results, a multi-rate CKF (Cubature Kalman Filter) algorithm with estimated residual compensation is proposed in order to adapt to the problem of sampling rate discrepancy. During inter-sampling of slow observation data, observation noise can be regarded as infinite. The Kalman gain is unknown and approaches zero. The residual is also unknown. Therefore, the filter estimated state cannot be compensated. To obtain compensation at these moments, state error and residual formulas are modified when compared with the observation data available moments. Self-propagation equation of the state error is established to propagate the quantity from the moments with observation to the moments without observation. Besides, a multiplicative adjustment factor is introduced as Kalman gain, which acts on the residual. Then the filter estimated state can be compensated even when there are no visual observation data. The proposed method is tested and verified in a practical setup. Compared with multi-rate CKF without residual compensation and single-rate CKF, a significant improvement is obtained on attitude measurement by using the proposed multi-rate CKF with inter-sampling residual compensation. The experiment results with superior precision and reliability show the effectiveness of the proposed method.

Asteroid orbital inversion using uniform phase-space sampling

NASA Astrophysics Data System (ADS)

Muinonen, K.; Pentikäinen, H.; Granvik, M.; Oszkiewicz, D.; Virtanen, J.

2014-07-01

We review statistical inverse methods for asteroid orbit computation from a small number of astrometric observations and short time intervals of observations. With the help of Markov-chain Monte Carlo methods (MCMC), we present a novel inverse method that utilizes uniform sampling of the phase space for the orbital elements. The statistical orbital ranging method (Virtanen et al. 2001, Muinonen et al. 2001) was set out to resolve the long-lasting challenges in the initial computation of orbits for asteroids. The ranging method starts from the selection of a pair of astrometric observations. Thereafter, the topocentric ranges and angular deviations in R.A. and Decl. are randomly sampled. The two Cartesian positions allow for the computation of orbital elements and, subsequently, the computation of ephemerides for the observation dates. Candidate orbital elements are included in the sample of accepted elements if the χ^2-value between the observed and computed observations is within a pre-defined threshold. The sample orbital elements obtain weights based on a certain debiasing procedure. When the weights are available, the full sample of orbital elements allows the probabilistic assessments for, e.g., object classification and ephemeris computation as well as the computation of collision probabilities. The MCMC ranging method (Oszkiewicz et al. 2009; see also Granvik et al. 2009) replaces the original sampling algorithm described above with a proposal probability density function (p.d.f.), and a chain of sample orbital elements results in the phase space. MCMC ranging is based on a bivariate Gaussian p.d.f. for the topocentric ranges, and allows for the sampling to focus on the phase-space domain with most of the probability mass. In the virtual-observation MCMC method (Muinonen et al. 2012), the proposal p.d.f. for the orbital elements is chosen to mimic the a posteriori p.d.f. for the elements: first, random errors are simulated for each observation, resulting in a set of virtual observations; second, corresponding virtual least-squares orbital elements are derived using the Nelder-Mead downhill simplex method; third, repeating the procedure two times allows for a computation of a difference for two sets of virtual orbital elements; and, fourth, this orbital-element difference constitutes a symmetric proposal in a random-walk Metropolis-Hastings algorithm, avoiding the explicit computation of the proposal p.d.f. In a discrete approximation, the allowed proposals coincide with the differences that are based on a large number of pre-computed sets of virtual least-squares orbital elements. The virtual-observation MCMC method is thus based on the characterization of the relevant volume in the orbital-element phase space. Here we utilize MCMC to map the phase-space domain of acceptable solutions. We can make use of the proposal p.d.f.s from the MCMC ranging and virtual-observation methods. The present phase-space mapping produces, upon convergence, a uniform sampling of the solution space within a pre-defined χ^2-value. The weights of the sampled orbital elements are then computed on the basis of the corresponding χ^2-values. The present method resembles the original ranging method. On one hand, MCMC mapping is insensitive to local extrema in the phase space and efficiently maps the solution space. This is somewhat contrary to the MCMC methods described above. On the other hand, MCMC mapping can suffer from producing a small number of sample elements with small χ^2-values, in resemblance to the original ranging method. We apply the methods to example near-Earth, main-belt, and transneptunian objects, and highlight the utilization of the methods in the data processing and analysis pipeline of the ESA Gaia space mission.

THE zCOSMOS-SINFONI PROJECT. I. SAMPLE SELECTION AND NATURAL-SEEING OBSERVATIONS

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

Mancini, C.; Renzini, A.; Foerster Schreiber, N. M.

2011-12-10

The zCOSMOS-SINFONI project is aimed at studying the physical and kinematical properties of a sample of massive z {approx} 1.4-2.5 star-forming galaxies, through SINFONI near-infrared integral field spectroscopy (IFS), combined with the multiwavelength information from the zCOSMOS (COSMOS) survey. The project is based on one hour of natural-seeing observations per target, and adaptive optics (AO) follow-up for a major part of the sample, which includes 30 galaxies selected from the zCOSMOS/VIMOS spectroscopic survey. This first paper presents the sample selection, and the global physical characterization of the target galaxies from multicolor photometry, i.e., star formation rate (SFR), stellar mass, age,more » etc. The H{alpha} integrated properties, such as, flux, velocity dispersion, and size, are derived from the natural-seeing observations, while the follow-up AO observations will be presented in the next paper of this series. Our sample appears to be well representative of star-forming galaxies at z {approx} 2, covering a wide range in mass and SFR. The H{alpha} integrated properties of the 25 H{alpha} detected galaxies are similar to those of other IFS samples at the same redshifts. Good agreement is found among the SFRs derived from H{alpha} luminosity and other diagnostic methods, provided the extinction affecting the H{alpha} luminosity is about twice that affecting the continuum. A preliminary kinematic analysis, based on the maximum observed velocity difference across the source and on the integrated velocity dispersion, indicates that the sample splits nearly 50-50 into rotation-dominated and velocity-dispersion-dominated galaxies, in good agreement with previous surveys.« less

Observed intra-cluster correlation coefficients in a cluster survey sample of patient encounters in general practice in Australia

PubMed Central

Knox, Stephanie A; Chondros, Patty

2004-01-01

Background Cluster sample study designs are cost effective, however cluster samples violate the simple random sample assumption of independence of observations. Failure to account for the intra-cluster correlation of observations when sampling through clusters may lead to an under-powered study. Researchers therefore need estimates of intra-cluster correlation for a range of outcomes to calculate sample size. We report intra-cluster correlation coefficients observed within a large-scale cross-sectional study of general practice in Australia, where the general practitioner (GP) was the primary sampling unit and the patient encounter was the unit of inference. Methods Each year the Bettering the Evaluation and Care of Health (BEACH) study recruits a random sample of approximately 1,000 GPs across Australia. Each GP completes details of 100 consecutive patient encounters. Intra-cluster correlation coefficients were estimated for patient demographics, morbidity managed and treatments received. Intra-cluster correlation coefficients were estimated for descriptive outcomes and for associations between outcomes and predictors and were compared across two independent samples of GPs drawn three years apart. Results Between April 1999 and March 2000, a random sample of 1,047 Australian general practitioners recorded details of 104,700 patient encounters. Intra-cluster correlation coefficients for patient demographics ranged from 0.055 for patient sex to 0.451 for language spoken at home. Intra-cluster correlations for morbidity variables ranged from 0.005 for the management of eye problems to 0.059 for management of psychological problems. Intra-cluster correlation for the association between two variables was smaller than the descriptive intra-cluster correlation of each variable. When compared with the April 2002 to March 2003 sample (1,008 GPs) the estimated intra-cluster correlation coefficients were found to be consistent across samples. Conclusions The demonstrated precision and reliability of the estimated intra-cluster correlations indicate that these coefficients will be useful for calculating sample sizes in future general practice surveys that use the GP as the primary sampling unit. PMID:15613248

Inception of Snapover and Gas Induced Glow Discharges

NASA Technical Reports Server (NTRS)

Galofaro, J. T.; Vayner, B. V.; Degroot, W. A.; Ferguson, D. C.; Thomson, C. D.; Dennison, J. R.; Davies, R. E.

2000-01-01

Ground based experiments of the snapover phenomenon were conducted in the large vertical simulation chamber at the Glenn Research Center (GRC) Plasma Interaction Facility (PIF). Two Penning sources provided both argon and xenon plasmas for the experiments. The sources were used to simulate a variety of ionospheric densities pertaining to a spacecraft in a Low Earth Orbital (LEO) environment. Secondary electron emission is believed responsible for dielectric surface charging, and all subsequent snapover phenomena observed. Voltage sweeps of conductor potentials versus collected current were recorded in order to examine the specific charging history of each sample. The average time constant for sample charging was estimated between 25 and 50 seconds for all samples. It appears that current drops off by approximately a factor of 3 over the charging time of the sample. All samples charged in the forward and reverse bias directions, demonstrated hysteresis. Current jumps were only observed in the forward or positive swept voltage direction. There is large dispersion in tile critical snapover potential when repeating sweeps on any one sample. The current ratio for the first snapover region jumps between 2 and 4.6 times, with a standard deviation less than 1.6. Two of the samples showed even larger current ratios. It is believed the second large snapover region is due to sample outgassing. Under certain preset conditions, namely at the higher neutral gas background pressures, a perceptible blue-green glow was observed around the conductor. The glow is believed to be a result of secondary electrons undergoing collisions with an expelled tenuous cloud of gas, that is outgassed from the sample. Spectroscopic measurements of the glow discharge were made in an attempt to identify specific lines contributing to the observed glow.

The analysis of ALK gene rearrangement by fluorescence in situ hybridization in non-small cell lung cancer patients

PubMed Central

Krawczyk, Paweł Adam; Ramlau, Rodryg Adam; Szumiło, Justyna; Kozielski, Jerzy; Kalinka-Warzocha, Ewa; Bryl, Maciej; Knopik-Dąbrowicz, Alina; Spychalski, Łukasz; Szczęsna, Aleksandra; Rydzik, Ewelina; Milanowski, Janusz

2013-01-01

Introduction ALK gene rearrangement is observed in a small subset (3–7%) of non-small cell lung cancer (NSCLC) patients. The efficacy of crizotinib was shown in lung cancer patients harbouring ALK rearrangement. Nowadays, the analysis of ALK gene rearrangement is added to molecular examination of predictive factors. Aim of the study The frequency of ALK gene rearrangement as well as the type of its irregularity was analysed by fluorescence in situ hybridisation (FISH) in tissue samples from NSCLC patients. Material and methods The ALK gene rearrangement was analysed in 71 samples including 53 histological and 18 cytological samples. The analysis could be performed in 56 cases (78.87%), significantly more frequently in histological than in cytological materials. The encountered problem with ALK rearrangement diagnosis resulted from the scarcity of tumour cells in cytological samples, high background fluorescence noises and fragmentation of cell nuclei. Results The normal ALK copy number without gene rearrangement was observed in 26 (36.62%) patients ALK gene polysomy without gene rearrangement was observed in 25 (35.21%) samples while in 3 (4.23%) samples ALK gene amplification was found. ALK gene rearrangement was observed in 2 (2.82%) samples from males, while in the first case the rearrangement coexisted with ALK amplification. In the second case, signet-ring tumour cells were found during histopathological examination and this patient was successfully treated with crizotinib with partial remission lasting 16 months. Conclusions FISH is a useful technique for ALK gene rearrangement analysis which allows us to specify the type of gene irregularities. ALK gene examination could be performed in histological as well as cytological (cellblocks) samples, but obtaining a reliable result in cytological samples depends on the cellularity of examined materials. PMID:24592134

A bacterial bioreporter panel to assay the cytotoxicity of atmospheric particulate matter

NASA Astrophysics Data System (ADS)

Kessler, Nivi; Schauer, James J.; Yagur-Kroll, Sharon; Melamed, Sahar; Tirosh, Ofir; Belkin, Shimshon; Erel, Yigal

2012-12-01

Numerous studies have demonstrated that elevated concentrations of suspended atmospheric particulate matter (PM) are associated with adverse health effects. In order to minimize the adverse public health effects of atmospheric PM by exposure management, there is a need for a greater understanding of the toxic mechanisms and the components that are responsible for the toxic effects. The aim of this study was to utilize bioassay techniques to investigate these aspects. For this purpose a reporter panel of 9 genetically engineered bacterial (Escherichia coli) strains was composed. Each panel member was designed to report on a different stress condition with a measurable light signal produced by the luciferase enzyme. Toxic mechanisms and components were studied using six anthropogenic PM source samples, including two vehicle combustion particles, three coal fly ash (CFA) samples and an urban dust sample. The most prominent outcome of the panel exposure results were broad panel responses observed for two of the CFA samples, indicating oxidative stress, respiration inhibition and iron deficiency. These responses were relieved when the samples were treated with EDTA, a non-specific metal chelator, suggesting the involvement of metals in the observed effects. Bioavailability analysis of the samples suggests that chromium was related to the toxic responses induced by two of the CFA samples. Oxidative stress was also observed in several samples of ambient atmospheric aerosols and excess metal toxicity in an urban dust sample collected in a parking lot. The reporter panel approach, as demonstrated in this study, has the potential of providing novel insights as to the mechanisms of atmospheric PM toxicity. Furthermore, combining the panel's results with bioavailability data can enlighten about the role of different PM components in the observed toxicity.

IR Observations of a Complete Unbiased Sample of Bright Seyfert Galaxies

NASA Astrophysics Data System (ADS)

Malkan, Matthew; Bendo, George; Charmandaris, Vassilis; Smith, Howard; Spinoglio, Luigi; Tommasin, Silvia

2008-03-01

IR spectra will measure the 2 main energy-generating processes by which galactic nuclei shine: black hole accretion and star formation. Both of these play roles in galaxy evolution, and they appear connected. To obtain a complete sample of AGN, covering the range of luminosities and column-densities, we will combine 2 complete all-sky samples with complementary selections, minimally biased by dust obscuration: the 116 IRAS 12um AGN and the 41 Swift/BAT hard Xray AGN. These galaxies have been extensively studied across the entire EM spectrum. Herschel observations have been requested and will be synergistic with the Spitzer database. IRAC and MIPS imaging will allow us to separate the nuclear and galactic continua. We are completing full IR observations of the local AGN population, most of which have already been done. The only remaining observations we request are 10 IRS/HIRES, 57 MIPS-24 and 30 IRAC pointings. These high-quality observations of bright AGN in the bolometric-flux-limited samples should be completed, for the high legacy value of complete uniform datasets. We will measure quantitatively the emission at each wavelength arising from stars and from accretion in each galactic center. Since our complete samples come from flux-limited all-sky surveys in the IR and HX, we will calculate the bi-variate AGN and star formation Luminosity Functions for the local population of active galaxies, for comparison with higher redshifts.Our second aim is to understand the physical differences between AGN classes. This requires statistical comparisons of full multiwavelength observations of complete representative samples. If the difference between Sy1s and Sy2s is caused by orientation, their isotropic properties, including those of the surrounding galactic centers, should be similar. In contrast, if they are different evolutionary stages following a galaxy encounter, then we may find observational evidence that the circumnuclear ISM of Sy2s is relatively younger.

A new estimator of the discovery probability.

PubMed

Favaro, Stefano; Lijoi, Antonio; Prünster, Igor

2012-12-01

Species sampling problems have a long history in ecological and biological studies and a number of issues, including the evaluation of species richness, the design of sampling experiments, and the estimation of rare species variety, are to be addressed. Such inferential problems have recently emerged also in genomic applications, however, exhibiting some peculiar features that make them more challenging: specifically, one has to deal with very large populations (genomic libraries) containing a huge number of distinct species (genes) and only a small portion of the library has been sampled (sequenced). These aspects motivate the Bayesian nonparametric approach we undertake, since it allows to achieve the degree of flexibility typically needed in this framework. Based on an observed sample of size n, focus will be on prediction of a key aspect of the outcome from an additional sample of size m, namely, the so-called discovery probability. In particular, conditionally on an observed basic sample of size n, we derive a novel estimator of the probability of detecting, at the (n+m+1)th observation, species that have been observed with any given frequency in the enlarged sample of size n+m. Such an estimator admits a closed-form expression that can be exactly evaluated. The result we obtain allows us to quantify both the rate at which rare species are detected and the achieved sample coverage of abundant species, as m increases. Natural applications are represented by the estimation of the probability of discovering rare genes within genomic libraries and the results are illustrated by means of two expressed sequence tags datasets. © 2012, The International Biometric Society.

Effect of field view size and lighting on unique-hue selection using Natural Color System object colors.

PubMed

Shamey, Renzo; Zubair, Muhammad; Cheema, Hammad

2015-08-01

The aim of this study was twofold, first to determine the effect of field view size and second of illumination conditions on the selection of unique hue samples (UHs: R, Y, G and B) from two rotatable trays, each containing forty highly chromatic Natural Color System (NCS) samples, on one tray corresponding to 1.4° and on the other to 5.7° field of view size. UH selections were made by 25 color-normal observers who repeated assessments three times with a gap of at least 24h between trials. Observers separately assessed UHs under four illumination conditions simulating illuminants D65, A, F2 and F11. An apparent hue shift (statistically significant for UR) was noted for UH selections at 5.7° field of view compared to those at 1.4°. Observers' overall variability was found to be higher for UH stimuli selections at the larger field of view. Intra-observer variability was found to be approximately 18.7% of inter-observer variability in selection of samples for both sample sizes. The highest intra-observer variability was under simulated illuminant D65, followed by A, F11, and F2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Observation of biexcitonic emission at extremely low power density in tungsten disulfide atomic layers grown on hexagonal boron nitride.

PubMed

Okada, Mitsuhiro; Miyauchi, Yuhei; Matsuda, Kazunari; Taniguchi, Takashi; Watanabe, Kenji; Shinohara, Hisanori; Kitaura, Ryo

2017-03-23

Monolayer transition metal dichalcogenides (TMDCs) including WS 2 , MoS 2 , WSe 2 and WS 2 , are two-dimensional semiconductors with direct bandgap, providing an excellent field for exploration of many-body effects in 2-dimensions (2D) through optical measurements. To fully explore the physics of TMDCs, the prerequisite is preparation of high-quality samples to observe their intrinsic properties. For this purpose, we have focused on high-quality samples, WS 2 grown by chemical vapor deposition method with hexagonal boron nitride as substrates. We observed sharp exciton emissions, whose linewidth is typically 22~23 meV, in photoluminescence spectra at room temperature, which result clearly demonstrates the high-quality of the current samples. We found that biexcitons formed with extremely low-excitation power (240 W/cm 2 ) at 80 K, and this should originate from the minimal amount of localization centers in the present high-quality samples. The results clearly demonstrate that the present samples can provide an excellent field, where one can observe various excitonic states, offering possibility of exploring optical physics in 2D and finding new condensates.

Real-time SEM studies in controlled reactive atmospheres

NASA Technical Reports Server (NTRS)

Gallagher, B. D.; Garcia, A., III; Alonzo, J. R.

1985-01-01

A unique scanning electron accessory has been developed that allows the observation of specimens under partial pressures of any gas. The sample is placed in a metal support boat inside a special sample holder. The sample in the boat is imaged on a CRT and is simultaneously recorded on a videotape, allowing the reaction between the sample and the gas to be observed in real time. Sample changes can be seen continuously as the sample is being heated or cooled. This process allows the observation of material transformations such as phase changes as they happen. Temperatures as high as 1000 C have been used and are continuously monitored using a thermocouple with a digital display on the CRT and videotape. X-ray analyses can also be run before and after any reactions. In the study described here, thick-film screen-printing inks using molybdenum/tin compositions as a replacement for silver were developed to be used on terrestrial photovoltaic cells. Pieces were placed on the sample stage and heated in both O2 and H2 atmospheres. The results were used to determine the most effective frits to be used in the thick-film inks.

An international standard for observation data

NASA Astrophysics Data System (ADS)

Cox, Simon

2010-05-01

A generic information model for observations and related features supports data exchange both within and between different scientific and technical communities. Observations and Measurements (O&M) formalizes a neutral terminology for observation data and metadata. It was based on a model developed for medical observations, and draws on experience from geology and mineral exploration, in-situ monitoring, remote sensing, intelligence, biodiversity studies, ocean observations and climate simulations. Hundreds of current deployments of Sensor Observation Services (SOS), covering multiple disciplines, provide validation of the O&M model. A W3C Incubator group on 'Semantic Sensor Networks' is now using O&M as one of the bases for development of a formal ontology for sensor networks. O&M defines the information describing observation acts and their results, including the following key terms: observation, result, observed-property, feature-of-interest, procedure, phenomenon-time, and result-time. The model separates of the (meta-)data associated with the observation procedure, the observed feature, and the observation event itself. Observation results may take various forms, including scalar quantities, categories, vectors, grids, or any data structure required to represent the value of some property of some observed feature. O&M follows the ISO/TC 211 General Feature Model so non-geometric properties must be associated with typed feature instances. This requires formalization of information that may be trivial when working within some earth-science sub-disciplines (e.g. temperature, pressure etc. are associated with the atmosphere or ocean, and not just a location) but is critical to cross-disciplinary applications. It also allows the same structure and terminology to be used for in-situ, ex-situ and remote sensing observations, as well as for simulations. For example: a stream level observation is an in-situ monitoring application where the feature-of-interest is a reach, the observed property is water-level, and the result is a time-series of heights; stream quality is usually determined by ex-situ observation where the feature-of-interest is a specimen that is recovered from the stream, the observed property is water-quality, and the result is a set of measures of various parameters, or an assessment derived from these; on the other hand, distribution of surface temperature of a water body is typically determined through remote-sensing, where at observation time the procedure is located distant from the feature-of-interest, and the result is an image or grid. Observations usually involve sampling of an ultimate feature-of-interest. In the environmental sciences common sampling strategies are used. Spatial sampling is classified primarily by topological dimension (point, curve, surface, volume) and is supported by standard processing and visualisation tools. Specimens are used for ex-situ processing in most disciplines. Sampling features are often part of complexes (e.g. specimens are sub-divided; specimens are retrieved from points along a transect; sections are taken across tracts), so relationships between instances must be recorded. And observational campaigns involve collections of sampling features. The sampling feature model is a core part of O&M, and application experience has shown that describing the relationships between sampling features and observations is generally critical to successful use of the model. O&M was developed through Open Geospatial Consortium (OGC) as part of the Sensor Web Enablement (SWE) initiative. Other SWE standards include SensorML, SOS, Sensor Planning Service (SPS). The OGC O&M standard (Version 1) had two parts: part 1 describes observation events, and part 2 provides a schema sampling features. A revised version of O&M (Version 2) is to be published in a single document as ISO 19156. O&M Version 1 included an XML encoding for data exchange, which is used as the payload for SOS responses. The new version will provide a UML model only. Since an XML encoding may be generated following a rule, such as that presented in ISO 19136 (GML 3.2), it is not included in the standard directly. O&M Version 2 thus supports multiple physical implementations and versions.

A method for three-dimensional quantitative observation of the microstructure of biological samples

NASA Astrophysics Data System (ADS)

Wang, Pengfei; Chen, Dieyan; Ma, Wanyun; Wu, Hongxin; Ji, Liang; Sun, Jialin; Lv, Danyu; Zhang, Lu; Li, Ying; Tian, Ning; Zheng, Jinggao; Zhao, Fengying

2009-07-01

Contemporary biology has developed into the era of cell biology and molecular biology, and people try to study the mechanism of all kinds of biological phenomena at the microcosmic level now. Accurate description of the microstructure of biological samples is exigent need from many biomedical experiments. This paper introduces a method for 3-dimensional quantitative observation on the microstructure of vital biological samples based on two photon laser scanning microscopy (TPLSM). TPLSM is a novel kind of fluorescence microscopy, which has excellence in its low optical damage, high resolution, deep penetration depth and suitability for 3-dimensional (3D) imaging. Fluorescent stained samples were observed by TPLSM, and afterward the original shapes of them were obtained through 3D image reconstruction. The spatial distribution of all objects in samples as well as their volumes could be derived by image segmentation and mathematic calculation. Thus the 3-dimensionally and quantitatively depicted microstructure of the samples was finally derived. We applied this method to quantitative analysis of the spatial distribution of chromosomes in meiotic mouse oocytes at metaphase, and wonderful results came out last.

Spectral bidirectional reflectance distribution function measurements on well-defined textured surfaces: direct observation of shadowing, masking, inter-reflection, and transparency effects.

PubMed

Wilen, Larry; Dasgupta, Bivash R

2011-11-01

We present results for the bidirectional reflectance distribution function (BRDF) for samples of uniform rectangular and triangular grooves constructed from polydimethylsilicone replicas. The measurements are performed with the detector in the plane of incidence, but with varying groove orientations with respect to that plane. The samples are opaque in some cases and semitransparent in others. By measuring the BRDF for colored samples over a wide spectral range, we explicitly probe the effect of sample albedo, which is important for inter-reflections. For the opaque samples, we compare the results with exact theoretical results either taken from the literature (for the triangular geometry) or worked out here (for the rectangular geometry). For both geometries, we also extend the theoretical results to finite length grooves. There is generally very good agreement between theory and the experiment. Shadowing, masking, and inter-reflection are clearly observed, as well as effects that may be due to polarization and asperity scattering. For semitransparent samples, we observe the effect of increasing transparency on the BRDF.

Interaction of two laser shocks inside iron samples

NASA Astrophysics Data System (ADS)

de Rességuier, T.; Hallouin, M.

2001-11-01

The interaction of two plane symmetric shocks in a solid sample induces a significant increase of both the pressure and the temperature in the central zone where the incident compressive pulses cross each other. In iron samples, such loading conditions may produce typical structural defects (twins, dislocations) and phase transitions that can be revealed by posttest examination of the recovered targets. We have used two high-power laser beams to irradiate simultaneously both surfaces of thin iron foils. The recovered samples have been sectioned and observed in optical microscopy. A very dense twin distribution in the central zone has confirmed the pressure amplification due to the interaction of the incident shocks. The occurrence of a phase transition has been inferred from the presence of short characteristic twins. Spall fraction has been observed near both irradiated surfaces, and additional damage has been evidenced at the center of the samples. Numerical tools have been adapted to simulate the experiments. Computations have provided estimates of the stress histories inside the samples, and the ability of simple twin, phase change, and spall models has been tested to predict the observed results.

Synthesis and characterization of nanocrystalline mesoporous zirconia using supercritical drying.

PubMed

Tyagi, Beena; Sidhpuria, Kalpesh; Shaik, Basha; Jasra, Raksh Vir

2006-06-01

Synthesis of nano-crystalline zirconia aerogel was done by sol-gel technique and supercritical drying using n-propanol solvent at and above supercritical temperature (235-280 degrees C) and pressure (48-52 bar) of n-propanol. Zirconia xerogel samples have also been prepared by conventional thermal drying method to compare with the super critically dried samples. Crystalline phase, crystallite size, surface area, pore volume, and pore size distribution were determined for all the samples in detail to understand the effect of gel drying methods on these properties. Supercritical drying of zirconia gel was observed to give thermally stable, nano-crystalline, tetragonal zirconia aerogels having high specific surface area and porosity with narrow and uniform pore size distribution as compared to thermally dried zirconia. With supercritical drying, zirconia samples show the formation of only mesopores whereas in thermally dried samples, substantial amount of micropores are observed along with mesopores. The samples prepared using supercritical drying yield nano-crystalline zirconia with smaller crystallite size (4-6 nm) as compared to higher crystallite size (13-20 nm) observed with thermally dried zirconia.

Relativistic effects on galaxy redshift samples due to target selection

NASA Astrophysics Data System (ADS)

Alam, Shadab; Croft, Rupert A. C.; Ho, Shirley; Zhu, Hongyu; Giusarma, Elena

2017-10-01

In a galaxy redshift survey, the objects to be targeted for spectra are selected from a photometrically observed sample. The observed magnitudes and colours of galaxies in this parent sample will be affected by their peculiar velocities, through relativistic Doppler and relativistic beaming effects. In this paper, we compute the resulting expected changes in galaxy photometry. The magnitudes of the relativistic effects are a function of redshift, stellar mass, galaxy velocity and velocity direction. We focus on the CMASS sample from the Sloan Digital Sky Survey (SDSS) and Baryon Oscillation Spectroscopic Survey (BOSS), which is selected on the basis of colour and magnitude. We find that 0.10 per cent of the sample (∼585 galaxies) has been scattered into the targeted region of colour-magnitude space by relativistic effects, and conversely 0.09 per cent of the sample (∼532 galaxies) has been scattered out. Observational consequences of these effects include an asymmetry in clustering statistics, which we explore in a companion paper. Here, we compute a set of weights that can be used to remove the effect of modulations introduced into the density field inferred from a galaxy sample. We conclude by investigating the possible effects of these relativistic modulation on large-scale clustering of the galaxy sample.

Fundamental Properties of the SHIELD Galaxies

NASA Astrophysics Data System (ADS)

Cannon, John; Adams, Betsey; Giovanelli, Riccardo; Haynes, Martha; Jones, Michael; McQuinn, Kristen; Rhode, Katherine; Salzer, John; Skillman, Evan

2018-05-01

The ALFALFA survey has significantly advanced our knowledge of the HI mass function (HIMF), particularly at the low mass end. From the ALFALFA survey, we have constructed a sample of all of the galaxies with HI masses less than 20 million solar masses. Observations of this 82 galaxy sample allow, for the first time, a characterization of the lowest HI mass galaxies at redshift zero. Specifically, this sample can be used to determine the low HI-mass ends of various fundamental scaling relations, including the critical baryonic Tully Fisher relation (BTFR) and the mass-metallicity (M-Z) relation. The M-Z relation and the BTFR are cosmologically important, but current samples leave the low-mass parameter spaces severely underpopulated. A full understanding of these relationships depends critically on accurate stellar masses of this complete sample of uniformly-selected galaxies. Here, we request imaging of the 70 galaxies in our sample that have not been observed with Spitzer. The proposed imaging will allow us to measure stellar masses and inclinations of the sample galaxies using a uniform observational approach. Comparison with (existing and in progress) interferometric HI imaging and with ground-based optical imaging and spectroscopy will enable a robust mass decomposition in each galaxy and accurate placements on the aforementioned scaling relationships. The observations proposed here will allow us to populate the mass continuum between mini-halos and bona fide dwarf galaxies, and to address a range of fundamental questions in galaxy formation and near-field cosmology.

Melissopalynological Characterization of North Algerian Honeys

PubMed Central

Nair, Samira; Meddah, Boumedienne; Aoues, Abdelkader

2013-01-01

A pollen analysis of Algerian honey was conducted on a total of 10 honey samples. The samples were prepared using the methodology described by Louveaux et al., that was then further adapted by Ohe et al. The samples were subsequently observed using light microscopy. A total of 36 pollen taxa were discovered and could be identified in the analyzed honey samples. Seventy percent of the studied samples belonged to the group ofmonofloral honeys represented by Eucalyptus globulus, Thymus vulgaris, Citrus sp. and Lavandula angustifolia. Multifloral honeys comprised 30% of the honey samples, with pollen grains of Lavandula stoechas (28.49%) standing out as the most prevalent. Based on cluster analysis, two different groups of honey were observed according to different pollen types found in the samples. The identified pollen spectrum of honey confirmed their botanical origin. PMID:28239099

IMOS National Reference Stations: a continental-wide physical, chemical and biological coastal observing system.

PubMed

Lynch, Tim P; Morello, Elisabetta B; Evans, Karen; Richardson, Anthony J; Rochester, Wayne; Steinberg, Craig R; Roughan, Moninya; Thompson, Peter; Middleton, John F; Feng, Ming; Sherrington, Robert; Brando, Vittorio; Tilbrook, Bronte; Ridgway, Ken; Allen, Simon; Doherty, Peter; Hill, Katherine; Moltmann, Tim C

2014-01-01

Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology.

IMOS National Reference Stations: A Continental-Wide Physical, Chemical and Biological Coastal Observing System

PubMed Central

Lynch, Tim P.; Morello, Elisabetta B.; Evans, Karen; Richardson, Anthony J.; Rochester, Wayne; Steinberg, Craig R.; Roughan, Moninya; Thompson, Peter; Middleton, John F.; Feng, Ming; Sherrington, Robert; Brando, Vittorio; Tilbrook, Bronte; Ridgway, Ken; Allen, Simon; Doherty, Peter; Hill, Katherine; Moltmann, Tim C.

2014-01-01

Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology. PMID:25517905

VizieR Online Data Catalog: 44 SZ-selected galaxy clusters ACT observations (Sifon+, 2016)

NASA Astrophysics Data System (ADS)

Sifon, C.; Battaglia, N.; Hasselfield, M.; Menanteau, F.; Barrientos, L. F.; Bond, J. R.; Crichton, D.; Devlin, M. J.; Dunner, R.; Hilton, M.; Hincks, A. D.; Hlozek, R.; Huffenberger, K. M.; Hughes, J. P.; Infante, L.; Kosowsky, A.; Marsden, D.; Marriage, T. A.; Moodley, K.; Niemack, M. D.; Page, L. A.; Spergel, D. N.; Staggs, S. T.; Trac, H.; Wollack, E. J.

2017-11-01

ACT is a 6-metre off-axis Gregorian telescope located at an altitude of 5200um in the Atacama desert in Chile, designed to observe the CMB at arcminute resolution. Galaxy clusters were detected in the 148GHz band by matched-filtering the maps with the pressure profile suggested by Arnaud et al. (2010A&A...517A..92A), fit to X-ray selected local (z<0.2) clusters, with varying cluster sizes,θ500, from 1.18 to 27-arcmin. Because of the complete overlap of ACT equatorial observations with Sloan Digital Sky Survey Data Release 8 (SDSS DR8; Aihara et al., 2011ApJS..193...29A) imaging, all cluster candidates were assessed with optical data (Menanteau et al., 2013ApJ...765...67M). We observed 20 clusters from the equatorial sample with the Gemini Multi-Object Spectrograph (GMOS) on the Gemini-South telescope, split in semesters 2011B (ObsID:GS-2011B-C-1, PI:Barrientos/Menanteau) and 2012A (ObsID:GS-2012A-C-1, PI:Menanteau), prioritizing clusters in the cosmological sample at 0.3

Surface-water quality in the upper San Antonio River Basin, Bexar County, Texas, 1992-98

USGS Publications Warehouse

Banta, J. Ryan; Slattery, Richard N.; Crow, Cassi L.

2012-01-01

The reported concentrations for the measured constituents varied among sites as well as between periodic and stormflow samples. Patterns for some constituents, such as nutrients, were observed; however, consistent patterns were not always observed for all analytes. For example, median concentrations for filtered ammonia, nitrate plus nitrite, organic nitrogen, and phosphorus generally were greater in periodic samples collected from the Medina and SAR Elmendorf sites as compared to samples collected from the other sites. Median concentrations of trace elements measured in periodic samples were generally less than concentrations measured in stormflow samples. In general, most of the concentrations of analyzed organic compounds were less than the laboratory reporting levels.

Carotenoid diagenesis in a marine sediment

NASA Technical Reports Server (NTRS)

Watts, C. D.; Maxwell, J. R.

1977-01-01

The major carotenoids at three levels (3, 40, and 175 m below the sediment-water interface) in a core from a marine sediment (Cariaco Trench, off Venezuela) have been examined. Mass and electronic spectral data have provided evidence for the onset of a progressive reduction of carotenoids in the geological column. The time scale of the process appears to depend on the particular carotenoid. Reduction of up to two double bonds is observed for the diol, zeaxanthin, in the oldest sediment (about 340,000 years old) but no reduction is observed in the younger samples (about 5000 and 56,000 years old). The diketone, canthaxanthin, shows evidence of reduction of up to two double bonds in the 56,000-yr sample and up to five double bonds in the oldest sample. No reduction of beta-carotene was observed in any of the samples.

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model.

PubMed

Solares, Santiago D

2014-01-01

This paper presents computational simulations of single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip-sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip-sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample properties and the AFM observables. The physics of the tip-sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided.

Observer-based output feedback control of networked control systems with non-uniform sampling and time-varying delay

NASA Astrophysics Data System (ADS)

Meng, Su; Chen, Jie; Sun, Jian

2017-10-01

This paper investigates the problem of observer-based output feedback control for networked control systems with non-uniform sampling and time-varying transmission delay. The sampling intervals are assumed to vary within a given interval. The transmission delay belongs to a known interval. A discrete-time model is first established, which contains time-varying delay and norm-bounded uncertainties coming from non-uniform sampling intervals. It is then converted to an interconnection of two subsystems in which the forward channel is delay-free. The scaled small gain theorem is used to derive the stability condition for the closed-loop system. Moreover, the observer-based output feedback controller design method is proposed by utilising a modified cone complementary linearisation algorithm. Finally, numerical examples illustrate the validity and superiority of the proposed method.

What is Next? Linking all Samples of Planet Earth.

NASA Astrophysics Data System (ADS)

Wyborn, L. A.; Lehnert, K.; Klump, J. F.; Arko, R. A.; Cox, S. J. D.; Devaraju, A.; Elger, K.; Murphy, F.; Fleischer, D.

2016-12-01

The process of sampling, observing and analyzing physical samples is not unique to the geosciences. Physical sampling (taking specimens) is a fundamental strategy in many natural sciences, typically to support ex-situ observations in laboratories with the goal of characterizing real-world entities or populations. Observations and measurements are made on individual specimens and their derived samples in various ways, with results reported in research publications. Research on an individual sample is often published in numerous articles, based on multiple, potentially unrelated research programs conducted over many years. Even high-volume Earth observation datasets are proxies of real world phenomena and require calibration by measurements made on position located, well described physical samples. Unique, persistent web-compatible identifiers for physical objects and related sampling features are required to ensure their unambiguous citation and connection to related datasets through web identifiers. Identifier systems have been established within specific domains (e.g., bio, geo, hydro) or different sectors (e.g., museums, government agencies, universities), including the International Geo Sample Number (IGSN) in the geosciences, which has been used for rock, fossil, mineral, soil, regolith, fluid, plant and synthetic materials. IGSNs are issued through a governance system that ensures they are globally unique. Each IGSN directs to a digital representation of the physical object via the Handle.net global resolver system, the same system used for resolving DOI. To enable the unique identification of all samples on Planet Earth and of data derived from them, the next step is to ensure IGSNs can either be integrated with comparable identifier systems in other domains/sectors, or introduced into domains that do not have a viable system. A registry of persistent identifier systems for physical samples would allow users to choose which system best suits their needs. Such a registry may also facilitate unifying best practice in these multiple systems to enable consistent referencing of physical samples and of methods used to link digital data to its sources. IGSNs could be extended into other domains, but additional methodologies of sample collection, curation and processing may need to be considered.

Prevalence of Malaria, Dengue, and Chikungunya Significantly Associated with Mosquito Breeding Sites

PubMed Central

Islam, Mohammad Nazrul; ZulKifle, Mohammad; Sherwani, Arish Mohammad Khan; Ghosh, Susanta Kumar; Tiwari, Satyanarayan

2011-01-01

Objectives: To observe the prevalence of malaria, dengue, and chikungunya and their association with mosquito breeding sites. Methods: The study was observational and analytical. A total of 162 houses and 670 subjects were observed during the study period. One hundred forty-two febrile patients were eligible for the study. After obtaining informed consent from all febrile patients, 140 blood samples were collected to diagnose malaria, dengue, and chikungunya. Larval samples were collected by the standard protocol that follows. Correlation of data was performed by Pearson correlation test. Results: Forty-seven blood samples were found positive: 33 for chikungunya, 3 for dengue, and 11 for malaria. Fifty-one out of 224 larval samples were found positive. Out of the 51 positive samples, 37 were positive for Aedes, 12 were positive for Anopheles, and two were positive for Culex larvae. Interpretation and Conclusion: Mosquito-borne fevers, especially malaria, dengue, and chikungunya, have shown a significant relationship with mosquito breeding sites. PMID:23610486

Room temperature luminescence and ferromagnetism of AlN:Fe

NASA Astrophysics Data System (ADS)

Li, H.; Cai, G. M.; Wang, W. J.

2016-06-01

AlN:Fe polycrystalline powders were synthesized by a modified solid state reaction (MSSR) method. Powder X-ray diffraction and transmission electron microscopy results reveal the single phase nature of the doped samples. In the doped AlN samples, Fe is in Fe2+ state. Room temperature ferromagnetic behavior is observed in AlN:Fe samples. Two photoluminescence peaks located at about 592 nm (2.09 eV) and 598 nm (2.07 eV) are observed in AlN:Fe samples. Our results suggest that AlN:Fe is a potential material for applications in spintronics and high power laser devices.

Search Coil vs. Fluxgate Magnetometer Measurements at Interplanetary Shocks

NASA Technical Reports Server (NTRS)

Wilson, L.B., III

2012-01-01

We present magnetic field observations at interplanetary shocks comparing two different sample rates showing significantly different results. Fluxgate magnetometer measurements show relatively laminar supercritical shock transitions at roughly 11 samples/s. Search coil magnetometer measurements at 1875 samples/s, however, show large amplitude (dB/B as large as 2) fluctuations that are not resolved by the fluxgate magnetometer. We show that these fluctuations, identified as whistler mode waves, would produce a significant perturbation to the shock transition region changing the interpretation from laminar to turbulent. Thus, previous observations of supercritical interplanetary shocks classified as laminar may have been under sampled.

The Psychopathy Q-Sort. Construct Validity Evidence in a Nonclinical Sample

ERIC Educational Resources Information Center

Fowler, Katherine A.; Lilienfeld, Scott O.

2007-01-01

Scant research has examined the validity of instruments that permit observer ratings of psychopathy. Using a nonclinical (undergraduate) sample, the authors examined the associations between both self- and observer ratings on a psychopathy prototype (Psychopathy Q-Sort, PQS) and widely used measures of psychopathy, antisocial behavior, and…

Observation procedure, observer gender, and behavior valence as determinants of sampling error in a behavior assessment analogue

PubMed Central

Farkas, Gary M.; Tharp, Roland G.

1980-01-01

Several factors thought to influence the representativeness of behavioral assessment data were examined in an analogue study using a multifactorial design. Systematic and unsystematic methods of observing group behavior were investigated using 18 male and 18 female observers. Additionally, valence properties of the observed behaviors were inspected. Observers' assessments of a videotape were compared to a criterion code that defined the population of behaviors. Results indicated that systematic observation procedures were more accurate than unsystematic procedures, though this factor interacted with gender of observer and valence of behavior. Additionally, males tended to sample more representatively than females. A third finding indicated that the negatively valenced behavior was overestimated, whereas the neutral and positively valenced behaviors were accurately assessed. PMID:16795631

The Orientation of Gastric Biopsy Samples Improves the Inter-observer Agreement of the OLGA Staging System.

PubMed

Cotruta, Bogdan; Gheorghe, Cristian; Iacob, Razvan; Dumbrava, Mona; Radu, Cristina; Bancila, Ion; Becheanu, Gabriel

2017-12-01

Evaluation of severity and extension of gastric atrophy and intestinal metaplasia is recommended to identify subjects with a high risk for gastric cancer. The inter-observer agreement for the assessment of gastric atrophy is reported to be low. The aim of the study was to evaluate the inter-observer agreement for the assessment of severity and extension of gastric atrophy using oriented and unoriented gastric biopsy samples. Furthermore, the quality of biopsy specimens in oriented and unoriented samples was analyzed. A total of 35 subjects with dyspeptic symptoms addressed for gastrointestinal endoscopy that agreed to enter the study were prospectively enrolled. The OLGA/OLGIM gastric biopsies protocol was used. From each subject two sets of biopsies were obtained (four from the antrum, two oriented and two unoriented, two from the gastric incisure, one oriented and one unoriented, four from the gastric body, two oriented and two unoriented). The orientation of the biopsy samples was completed using nitrocellulose filters (Endokit®, BioOptica, Milan, Italy). The samples were blindly examined by two experienced pathologists. Inter-observer agreement was evaluated using kappa statistic for inter-rater agreement. The quality of histopathology specimens taking into account the identification of lamina propria was analyzed in oriented vs. unoriented samples. The samples with detectable lamina propria mucosae were defined as good quality specimens. Categorical data was analyzed using chi-square test and a two-sided p value <0.05 was considered statistically significant. A total of 350 biopsy samples were analyzed (175 oriented / 175 unoriented). The kappa index values for oriented/unoriented OLGA 0/I/II/III and IV stages have been 0.62/0.13, 0.70/0.20, 0.61/0.06, 0.62/0.46, and 0.77/0.50, respectively. For OLGIM 0/I/II/III stages the kappa index values for oriented/unoriented samples were 0.83/0.83, 0.88/0.89, 0.70/0.88 and 0.83/1, respectively. No case of OLGIM IV stage was found in the present case series. Good quality histopathology specimens were described in 95.43% of the oriented biopsy samples, and in 89.14% of the unoriented biopsy samples, respectively (p=0.0275). The orientation of gastric biopsies specimens improves the inter-observer agreement for the assessment of gastric atrophy.

Digital Curation of Earth Science Samples Starts in the Field

NASA Astrophysics Data System (ADS)

Lehnert, K. A.; Hsu, L.; Song, L.; Carter, M. R.

2014-12-01

Collection of physical samples in the field is an essential part of research in the Earth Sciences. Samples provide a basis for progress across many disciplines, from the study of global climate change now and over the Earth's history, to present and past biogeochemical cycles, to magmatic processes and mantle dynamics. The types of samples, methods of collection, and scope and scale of sampling campaigns are highly diverse, ranging from large-scale programs to drill rock and sediment cores on land, in lakes, and in the ocean, to environmental observation networks with continuous sampling, to single investigator or small team expeditions to remote areas around the globe or trips to local outcrops. Cyberinfrastructure for sample-related fieldwork needs to cater to the different needs of these diverse sampling activities, aligning with specific workflows, regional constraints such as connectivity or climate, and processing of samples. In general, digital tools should assist with capture and management of metadata about the sampling process (location, time, method) and the sample itself (type, dimension, context, images, etc.), management of the physical objects (e.g., sample labels with QR codes), and the seamless transfer of sample metadata to data systems and software relevant to the post-sampling data acquisition, data processing, and sample curation. In order to optimize CI capabilities for samples, tools and workflows need to adopt community-based standards and best practices for sample metadata, classification, identification and registration. This presentation will provide an overview and updates of several ongoing efforts that are relevant to the development of standards for digital sample management: the ODM2 project that has generated an information model for spatially-discrete, feature-based earth observations resulting from in-situ sensors and environmental samples, aligned with OGC's Observation & Measurements model (Horsburgh et al, AGU FM 2014); implementation of the IGSN (International Geo Sample Number) as a globally unique sample identifier via a distributed system of allocating agents and a central registry; and the EarthCube Research Coordination Network iSamplES (Internet of Samples in the Earth Sciences) that aims to improve sharing and curation of samples through the use of CI.

ODM2 (Observation Data Model): The EarthChem Use Case

NASA Astrophysics Data System (ADS)

Lehnert, Kerstin; Song, Lulin; Hsu, Leslie; Horsburgh, Jeffrey S.; Aufdenkampe, Anthony K.; Mayorga, Emilio; Tarboton, David; Zaslavsky, Ilya

2014-05-01

PetDB is an online data system that was created in the late 1990's to serve online a synthesis of published geochemical and petrological data of igneous and metamorphic rocks. PetDB has today reached a volume of 2.5 million analytical values for nearly 70,000 rock samples. PetDB's data model (Lehnert et al., G-Cubed 2000) was designed to store sample-based observational data generated by the analysis of rocks, together with a wide range of metadata documenting provenance of the samples, analytical procedures, data quality, and data source. Attempts to store additional types of geochemical data such as time-series data of seafloor hydrothermal springs and volcanic gases, depth-series data for marine sediments and soils, and mineral or mineral inclusion data revealed the limitations of the schema: the inability to properly record sample hierarchies (for example, a garnet that is included in a diamond that is included in a xenolith that is included in a kimberlite rock sample), inability to properly store time-series data, inability to accommodate classification schemes other than rock lithologies, deficiencies of identifying and documenting datasets that are not part of publications. In order to overcome these deficiencies, PetDB has been developing a new data schema using the ODM2 information model (ODM=Observation Data Model). The development of ODM2 is a collaborative project that leverages the experience of several existing information representations, including PetDB and EarthChem, and the CUAHSI HIS Observations Data Model (ODM), as well as the general specification for encoding observational data called Observations and Measurements (O&M) to develop a uniform information model that seamlessly manages spatially discrete, feature-based earth observations from environmental samples and sample fractions as well as in-situ sensors, and to test its initial implementation in a variety of user scenarios. The O&M model, adopted as an international standard by the Open Geospatial Consortium, and later by ISO, is the foundation of several domain markup languages such as OGC WaterML 2, used for exchanging hydrologic time series. O&M profiles for samples and sample fractions have not been standardized yet, and there is a significant variety in sample data representations used across agencies and academic projects. The intent of the ODM2 project is to create a unified relational representation for different types of spatially discrete observational data, ensuring that the data can be efficiently stored, transferred, catalogued and queried within a variety of earth science applications. We will report on the initial design and implementation of the new model for PetDB, and results of testing the model against a set of common queries. We have explored several aspects of the model, including: semantic consistency, validation and integrity checking, portability and maintainability, query efficiency, and scalability. The sample datasets from PetDB have been loaded in the initial physical implementation for testing. The results of the experiments point to both benefits and challenges of the initial design, and illustrate the key trade-off between the generality of design, ease of interpretation, and query efficiency, especially as the system needs to scale to millions of records.

Speeding Up Non-Parametric Bootstrap Computations for Statistics Based on Sample Moments in Small/Moderate Sample Size Applications

PubMed Central

Chaibub Neto, Elias

2015-01-01

In this paper we propose a vectorized implementation of the non-parametric bootstrap for statistics based on sample moments. Basically, we adopt the multinomial sampling formulation of the non-parametric bootstrap, and compute bootstrap replications of sample moment statistics by simply weighting the observed data according to multinomial counts instead of evaluating the statistic on a resampled version of the observed data. Using this formulation we can generate a matrix of bootstrap weights and compute the entire vector of bootstrap replications with a few matrix multiplications. Vectorization is particularly important for matrix-oriented programming languages such as R, where matrix/vector calculations tend to be faster than scalar operations implemented in a loop. We illustrate the application of the vectorized implementation in real and simulated data sets, when bootstrapping Pearson’s sample correlation coefficient, and compared its performance against two state-of-the-art R implementations of the non-parametric bootstrap, as well as a straightforward one based on a for loop. Our investigations spanned varying sample sizes and number of bootstrap replications. The vectorized bootstrap compared favorably against the state-of-the-art implementations in all cases tested, and was remarkably/considerably faster for small/moderate sample sizes. The same results were observed in the comparison with the straightforward implementation, except for large sample sizes, where the vectorized bootstrap was slightly slower than the straightforward implementation due to increased time expenditures in the generation of weight matrices via multinomial sampling. PMID:26125965

Sample size calculations for randomized clinical trials published in anesthesiology journals: a comparison of 2010 versus 2016.

PubMed

Chow, Jeffrey T Y; Turkstra, Timothy P; Yim, Edmund; Jones, Philip M

2018-06-01

Although every randomized clinical trial (RCT) needs participants, determining the ideal number of participants that balances limited resources and the ability to detect a real effect is difficult. Focussing on two-arm, parallel group, superiority RCTs published in six general anesthesiology journals, the objective of this study was to compare the quality of sample size calculations for RCTs published in 2010 vs 2016. Each RCT's full text was searched for the presence of a sample size calculation, and the assumptions made by the investigators were compared with the actual values observed in the results. Analyses were only performed for sample size calculations that were amenable to replication, defined as using a clearly identified outcome that was continuous or binary in a standard sample size calculation procedure. The percentage of RCTs reporting all sample size calculation assumptions increased from 51% in 2010 to 84% in 2016. The difference between the values observed in the study and the expected values used for the sample size calculation for most RCTs was usually > 10% of the expected value, with negligible improvement from 2010 to 2016. While the reporting of sample size calculations improved from 2010 to 2016, the expected values in these sample size calculations often assumed effect sizes larger than those actually observed in the study. Since overly optimistic assumptions may systematically lead to underpowered RCTs, improvements in how to calculate and report sample sizes in anesthesiology research are needed.

Study of properties of tungsten irradiated in hydrogen atmosphere

NASA Astrophysics Data System (ADS)

Tazhibayeva, I.; Skakov, M.; Baklanov, V.; Koyanbayev, E.; Miniyazov, A.; Kulsartov, T.; Ponkratov, Yu.; Gordienko, Yu.; Zaurbekova, Zh.; Kukushkin, I.; Nesterov, E.

2017-12-01

The paper presents the results of the experiments with DF (double forged) tungsten samples irradiated at the WWR-K research reactor in hydrogen and helium atmospheres. The irradiation time was 3255 h (135.6 d). After reactor irradiation, W samples have been subjected to investigations of their activity level, hardness, and microstructure, as well as x-ray and texture observations. The hydrogen yield released from irradiated tungsten samples have been measured using TDS-method. The hydrogen concentration in the tungsten samples irradiated in hydrogen was higher than that in the samples irradiated in helium atmosphere. It is shown that the surface microstructure of tungsten samples irradiated in hydrogen is characterized by micro-pits, inclusions and blisters in the form of bubbles, which were not observed earlier for tungsten irradiated in hydrogen.

Cluster designs to assess the prevalence of acute malnutrition by lot quality assurance sampling: a validation study by computer simulation

PubMed Central

Olives, Casey; Pagano, Marcello; Deitchler, Megan; Hedt, Bethany L; Egge, Kari; Valadez, Joseph J

2009-01-01

Traditional lot quality assurance sampling (LQAS) methods require simple random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67×3 (67 clusters of three observations) and a 33×6 (33 clusters of six observations) sampling scheme to assess the prevalence of global acute malnutrition (GAM). Further, we explore the use of a 67×3 sequential sampling scheme for LQAS classification of GAM prevalence. Results indicate that, for independent clusters with moderate intracluster correlation for the GAM outcome, the three sampling designs maintain approximate validity for LQAS analysis. Sequential sampling can substantially reduce the average sample size that is required for data collection. The presence of intercluster correlation can impact dramatically the classification error that is associated with LQAS analysis. PMID:20011037

Total airborne mold particle sampling: evaluation of sample collection, preparation and counting procedures, and collection devices.

PubMed

Godish, Diana; Godish, Thad

2008-02-01

This study was conducted to evaluate (i) procedures used to collect, prepare, and count total airborne mold spore/particle concentrations, and (ii) the relative field performance of three commercially available total airborne mold spore/particle sampling devices. Differences between factory and laboratory airflow calibration values of axial fan-driven sampling instruments (used in the study) indicated a need for laboratory calibration using a mass flow meter to ensure that sample results were accurately calculated. An aniline blue-amended Calberla's solution adjusted to a pH of 4.2-4.4 provided good sample mounting/counting results using Dow Corning high vacuum grease, Dow Corning 280A adhesive, and Dow Corning 316 silicone release spray for samples collected using mini-Burkard and Allergenco samplers. Count variability among analysts was most pronounced in 5% counts of relatively low mold particle deposition density samples and trended downward with increased count percentage and particle deposition density. No significant differences were observed among means of 5, 10, and 20% counts and among analysts; a significant interaction effect was observed between analysts' counts and particle deposition densities. Significantly higher mini-Burkard and Air-O-Cell total mold spore/particle counts for 600x vs. 400x (1.9 and 2.3 x higher, respectively), 1000x vs. 600x (1.9 and 2.2 x higher, respectively) and 1000x vs. 400x (3.6 and 4.6 x higher, respectively) comparisons indicated that 1000x magnification counts best quantified total airborne mold spore/particles using light microscopy, and that lower magnification counts may result in unacceptable underreporting of airborne mold spore/particle concentrations. Modest but significantly higher (1.2x) total mold spore concentrations were observed with Allergenco vs. mini-Burkard samples collected in co-located, concurrently operated sampler studies; moderate but significantly higher mini-Burkard count values (1.4x) were observed in similar studies with Air-O-Cell samplers. These count differences were relatively small compared with the large differences observed among three count magnifications.

Temperature-dependent phosphorous dopant activation in ZnO thin film deposited using plasma immersion ion implantation

NASA Astrophysics Data System (ADS)

Murkute, Punam; Ghadi, Hemant; Saha, Shantanu; Chavan, Vinayak; Chakrabarti, Subhananda

2018-03-01

High band gap (3.34 eV) and large exciton binding energy (60 meV) at room temperature facilitates ZnO as a useful candidate for optoelectronics devices. Presence of zinc interstitial and oxygen vacancies results in n-type ZnO film. Phosphorus implantation was carried out using plasma immersion ion implantation technique (2kV, 900W) for constant duration (50 s) on RF sputtered ZnO thin films (Sample A). For dopant activation, sample A was subjected to Rapid Thermal Annealing (RTA) at 700, 800, 900 and 1000°C for 10 s in Oxygen ambient (Sample B, C, D, E). Low temperature (18 K) photoluminescence measurement demonstrated strong donor bound exciton peak for sample A. Dominant donor to acceptor pair peak (DAP) was observed for sample D at around 3.22 eV with linewidth of 131.3 meV. High resolution x-ray diffraction measurement demonstrated (001) and (002) peaks for sample A. (002) peak with high intensity was observed from all annealed samples. Incorporation of phosphorus in ZnO films leads to peak shift towards higher 2θ angle indicate tensile strain in implanted samples. Scanning electron microscopy images reveals improvement in grain size distribution along with reduction of implantation related defects. Raman spectra measured A1(LO) peak at around 576 cm-1 for sample A. Low intensity E2 (high) peak was observed for sample D indicating formation of (PZn+2VZn) complexes. From room temperature Hall measurement, sample D measured 1.17 x 1018 cm -3 carrier concentration with low resistivity of 0.464 Ω.

Preliminary Results From Observing The Fast Stardust Sample Return Capsule Entry In Earth's Atmosphere On January 15, 2006.

NASA Astrophysics Data System (ADS)

Jenniskens, P.; Jordan, D.; Kontinos, D.; Wright, M.; Olejniczak, J.; Raiche, G.; Wercinski, P.; Schilling, E.; Taylor, M.; Rairden, R.; Stenbaek-Nielsen, H.; McHarg, M. G.; Abe, S.; Winter, M.

2006-08-01

In order for NASA's Stardust mission to return a comet sample to Earth, the probe was put in an orbit similar to that of Near Earth Asteroids. As a result, the reentry in Earth's atmosphere on January 15, 2006, was the fastest entry ever for a NASA spacecraft, with a speed of 12.8 km/s, similar to that of natural fireballs. A new thermal protection material, PICA, was used to protect the sample, a material that may have a future as thermal protection for the Crew Return Vehicle or for future planetary missions. An airborne and ground-based observing campaign, the "Stardust Hyperseed MAC", was organized to observe the reentry under good observing conditions, with spectroscopic and imaging techniques commonly used for meteor observations (http:// reentry.arc.nasa.gov). A spectacular video of the reentry was obtained. The spectroscopic observations measure how much light was generated in the shock wave, how that radiation added to heating the surface, how the PICA ablated as a function of altitude, and how the carbon reacted with the shock wave to form CN, a possible marker of prebiotic chemistry in natural meteors. In addition, the observations measured a transient signal of zinc and potassium early in the trajectory, from the ablation of a white paint layer that had been applied to the heat shield for thermal control. Implications for sample return and the exploration of atmospheres in future planetary missions will be discussed.

Evaluation of Bayesian estimation of a hidden continuous-time Markov chain model with application to threshold violation in water-quality indicators

USGS Publications Warehouse

Deviney, Frank A.; Rice, Karen; Brown, Donald E.

2012-01-01

Natural resource managers require information concerning  the frequency, duration, and long-term probability of occurrence of water-quality indicator (WQI) violations of defined thresholds. The timing of these threshold crossings often is hidden from the observer, who is restricted to relatively infrequent observations. Here, a model for the hidden process is linked with a model for the observations, and the parameters describing duration, return period, and long-term probability of occurrence are estimated using Bayesian methods. A simulation experiment is performed to evaluate the approach under scenarios based on the equivalent of a total monitoring period of 5-30 years and an observation frequency of 1-50 observations per year. Given constant threshold crossing rate, accuracy and precision of parameter estimates increased with longer total monitoring period and more-frequent observations. Given fixed monitoring period and observation frequency, accuracy and precision of parameter estimates increased with longer times between threshold crossings. For most cases where the long-term probability of being in violation is greater than 0.10, it was determined that at least 600 observations are needed to achieve precise estimates.  An application of the approach is presented using 22 years of quasi-weekly observations of acid-neutralizing capacity from Deep Run, a stream in Shenandoah National Park, Virginia. The time series also was sub-sampled to simulate monthly and semi-monthly sampling protocols. Estimates of the long-term probability of violation were unbiased despite sampling frequency; however, the expected duration and return period were over-estimated using the sub-sampled time series with respect to the full quasi-weekly time series.

Multi-Objective Design Of Optimal Greenhouse Gas Observation Networks

NASA Astrophysics Data System (ADS)

Lucas, D. D.; Bergmann, D. J.; Cameron-Smith, P. J.; Gard, E.; Guilderson, T. P.; Rotman, D.; Stolaroff, J. K.

2010-12-01

One of the primary scientific functions of a Greenhouse Gas Information System (GHGIS) is to infer GHG source emission rates and their uncertainties by combining measurements from an observational network with atmospheric transport modeling. Certain features of the observational networks that serve as inputs to a GHGIS --for example, sampling location and frequency-- can greatly impact the accuracy of the retrieved GHG emissions. Observation System Simulation Experiments (OSSEs) provide a framework to characterize emission uncertainties associated with a given network configuration. By minimizing these uncertainties, OSSEs can be used to determine optimal sampling strategies. Designing a real-world GHGIS observing network, however, will involve multiple, conflicting objectives; there will be trade-offs between sampling density, coverage and measurement costs. To address these issues, we have added multi-objective optimization capabilities to OSSEs. We demonstrate these capabilities by quantifying the trade-offs between retrieval error and measurement costs for a prototype GHGIS, and deriving GHG observing networks that are Pareto optimal. [LLNL-ABS-452333: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Study of anisotropy, magnetization reversal and damping in ultrathin Co films on MgO (0 0 1) substrate

NASA Astrophysics Data System (ADS)

Mallik, Srijani; Bedanta, Subhankar

2018-01-01

Ultrathin Co films of 3 nm thickness have been prepared on MgO (0 0 1) substrate in presence or absence of substrate pre-annealing. Uniaxial anisotropy is induced in the samples due to the deposition under oblique angle of incidence. Along with the oblique deposition induced anisotropy, another uniaxial anisotropy contribution has been observed due to pre-annealing. However, no cubic anisotropy has been observed here as compared to the thicker films. Angle dependent ferromagnetic resonance (FMR) measurement confirms the presence of two anisotropies in the pre-annealed sample with ∼18° misalignment with each other. The two anisotropy constants were calculated from both superconducting quantum interference device (SQUID) magnetometry and FMR spectroscopy. The magnetization reversal is governed by nucleation dominated aftereffect followed by domain wall motion for the pre-annealed sample. Branched domains are observed for the sample prepared without pre-annealing which indicates grain disorientation of Co. However, in the thicker (25 nm) Co films ripple domains were observed in contrary to ultrathin (3 nm) films.

The quasar proximity effect in an equivalent-width-limited sample of the Lyman-alpha forest

NASA Technical Reports Server (NTRS)

Chernomordik, Viktor V.; Ozernoy, Leonid M.

1993-01-01

We have obtained a simple analytical approximation to the relationship between a rest-frame equivalent-width distribution for Ly-alpha forest absorption lines, N(W), and an H I column density distribution of the observed cloud number, N(N). Assuming a simple power-law form for N(N) proportional to N exp (1-beta), it is shown that beta = 1.4 turns out to agree fairly well with the observed form of N(W) in a broad range of column densities. We present a theoretical analysis of how the 'proximity effect' influences a W-limited sample of Ly-alpha forest lines. It is shown that this influence is considerably smaller than has been found before for a N-limited sample, for which an approximate value of beta was assumed rather than derived as has been done, for a W-limited sample, in the present paper. As a result, available observational data appear to be still consistent with the conjecture that the observed population of QSOs is the major source of the UV background at redshifts z about 2-4.

Foam generation and sample composition optimization for the FOAM-C experiment of the ISS

NASA Astrophysics Data System (ADS)

Carpy, R.; Picker, G.; Amann, B.; Ranebo, H.; Vincent-Bonnieu, S.; Minster, O.; Winter, J.; Dettmann, J.; Castiglione, L.; Höhler, R.; Langevin, D.

2011-12-01

End of 2009 and early 2010 a sealed cell, for foam generation and observation, has been designed and manufactured at Astrium Friedrichshafen facilities. With the use of this cell, different sample compositions of "wet foams" have been optimized for mixtures of chemicals such as water, dodecanol, pluronic, aethoxisclerol, glycerol, CTAB, SDS, as well as glass beads. This development is performed in the frame of the breadboarding development activities of the Experiment Container FOAM-C for operation in the ISS Fluid Science Laboratory (ISS). The sample cell supports multiple observation methods such as: Diffusing-Wave and Diffuse Transmission Spectrometry, Time Resolved Correlation Spectroscopy [1] and microscope observation, all of these methods are applied in the cell with a relatively small experiment volume <3cm3. These units, will be on orbit replaceable sets, that will allow multiple sample compositions processing (in the range of >40).

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

PubMed Central

2014-01-01

Summary This paper presents computational simulations of single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip–sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip–sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample properties and the AFM observables. The physics of the tip–sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided. PMID:25383277

Processing of strong flux trapping high T(subc) oxide superconductors: Center director's discretionary fund

NASA Technical Reports Server (NTRS)

Wu, M. K.; Higgins, C. A.; Leong, P. T.; Chou, H.; Loo, B. H.; Curreri, P. A.; Peters, P. N.; Sisk, R. C.; Huang, C. Y.; Shapira, Y.

1989-01-01

Magnetic suspension effect was first observed in samples of YBa2Cu3O7/AgO(Y-123/AgO) composites. Magnetization measurements of these samples show a much larger hysteresis which corresponds to a large critical current density. In addition to the Y-123AgO composites, recently similar suspension effects in other RE-123/AgO, where RE stands for rare-Earth elements, were also observed. Some samples exhibit even stronger flux pinning than that of the Y-123/AgO sample. An interesting observation was that in order to form the composite which exhibits strong flux trapping effect the sintering temperature depends on the particular RE-123 compound used. The paper presents the detailed processing conditions for the formation of these RE-123/AgO composites, as well as the magnetization and critical field data.

Faulting processes in active faults - Evidences from TCDP and SAFOD drill core samples

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

Janssen, C.; Wirth, R.; Wenk, H. -R.

The microstructures, mineralogy and chemistry of representative samples collected from the cores of the San Andreas Fault drill hole (SAFOD) and the Taiwan Chelungpu-Fault Drilling project (TCDP) have been studied using optical microscopy, TEM, SEM, XRD and XRF analyses. SAFOD samples provide a transect across undeformed host rock, the fault damage zone and currently active deforming zones of the San Andreas Fault. TCDP samples are retrieved from the principal slip zone (PSZ) and from the surrounding damage zone of the Chelungpu Fault. Substantial differences exist in the clay mineralogy of SAFOD and TCDP fault gouge samples. Amorphous material has beenmore » observed in SAFOD as well as TCDP samples. In line with previous publications, we propose that melt, observed in TCDP black gouge samples, was produced by seismic slip (melt origin) whereas amorphous material in SAFOD samples was formed by comminution of grains (crush origin) rather than by melting. Dauphiné twins in quartz grains of SAFOD and TCDP samples may indicate high seismic stress. The differences in the crystallographic preferred orientation of calcite between SAFOD and TCDP samples are significant. Microstructures resulting from dissolution–precipitation processes were observed in both faults but are more frequently found in SAFOD samples than in TCDP fault rocks. As already described for many other fault zones clay-gouge fabrics are quite weak in SAFOD and TCDP samples. Clay-clast aggregates (CCAs), proposed to indicate frictional heating and thermal pressurization, occur in material taken from the PSZ of the Chelungpu Fault, as well as within and outside of the SAFOD deforming zones, indicating that these microstructures were formed over a wide range of slip rates.« less

Magnetic studies of cobalt doped barium hexaferrite nanoparticles prepared by modified sol-gel method

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

Shalini, M. Govindaraj; Sahoo, Subasa C., E-mail: subasa@cukerala.ac.in

2016-05-06

M-type barium hexaferrite (BaFe{sub 12}O{sub 19}) and cobalt doped barium hexaferrite (BaFe{sub 11}CoO{sub 19}) nanopowders were synthesized by modified sol-gel auto-combustion technique and were annealed at 900°C in air for 4 hours. The annealed powders were studied in the present work and X-ray diffraction studies showed pure phase formation after annealing. The average grain size in the nanopowder sample was decreased after doping. Magnetization value of 60 emu/g was observed at 300 K for the barium hexaferrite and was reduced to 54 emu/g after doping. The coercivity of 5586 Oe was observed at 300 K for the undoped sample andmore » was found to be decreased in the doped sample. As the measurement temperature was decreased from 300 K to 60 K, magnetization value was increased in both the samples compared to those at 300 K. The coercivity of the undoped sample was found to decrease whereas it was increased for the doped sample at 60 K. The observed magnetic properties may be understood on the basis of modified exchange interaction and anisotropy in the doped sample compared to that of pure barium hexaferrite.« less

Searching for the 3.5 keV Line in the Stacked Suzaku Observations of Galaxy Clusters

NASA Technical Reports Server (NTRS)

Bulbul, Esra; Markevitch, Maxim; Foster, Adam; Miller, Eric; Bautz, Mark; Lowenstein, Mike; Randall, Scott W.; Smith, Randall K.

2016-01-01

We perform a detailed study of the stacked Suzaku observations of 47 galaxy clusters, spanning a redshift range of 0.01-0.45, to search for the unidentified 3.5 keV line. This sample provides an independent test for the previously detected line. We detect a 2sigma-significant spectral feature at 3.5 keV in the spectrum of the full sample. When the sample is divided into two subsamples (cool-core and non-cool core clusters), the cool-core subsample shows no statistically significant positive residuals at the line energy. A very weak (approx. 2sigma confidence) spectral feature at 3.5 keV is permitted by the data from the non-cool-core clusters sample. The upper limit on a neutrino decay mixing angle of sin(sup 2)(2theta) = 6.1 x 10(exp -11) from the full Suzaku sample is consistent with the previous detections in the stacked XMM-Newton sample of galaxy clusters (which had a higher statistical sensitivity to faint lines), M31, and Galactic center, at a 90% confidence level. However, the constraint from the present sample, which does not include the Perseus cluster, is in tension with previously reported line flux observed in the core of the Perseus cluster with XMM-Newton and Suzaku.

Determination of hazardous ingredients in personal care products using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Abrar, M.; Iqbal, T.; Fahad, M.; Andleeb, M.; Farooq, Z.; Afsheen, S.

2018-05-01

In the present work, the laser-induced breakdown spectroscopy technique is applied to explore the concentration of toxic elements present in cosmetic materials. The elemental analysis of chromium (Cr), magnesium (Mg), cadmium (Cd) and lead (Pb) are selected as major elements and manganese (Mn), sodium (Na), potassium (P), sulfur (S), silicon (Si) and titanium (Ti) as minor elements in cosmetic products. In this technique, a plasma plume is generated by using an Nd:YAG Laser of 532 nm wavelength and spectral lines for the respective samples are observed. Four different samples of cosmetic products are selected, i.e. two samples for lipstick and two for eyeshadow. The observed spectral lines of all major and minor elements are used to calculate their concentration in all samples through the intensity ratio method. Among selected lipstick and eyeshadow samples, one sample is branded, and one is collected from the local market. It is observed that chromium, magnesium and lead have strong spectral lines and consequently show high concentration. The calculated concentrations are then compared to permissible limits set by the Food and Drug Administration with regard to the cosmetics industry. The concentration of these toxic elements in selected local cosmetic samples exceeds the safe permissible limit for human use and could lead to serious health problems.

Reporting and methodological quality of sample size calculations in cluster randomized trials could be improved: a review.

PubMed

Rutterford, Clare; Taljaard, Monica; Dixon, Stephanie; Copas, Andrew; Eldridge, Sandra

2015-06-01

To assess the quality of reporting and accuracy of a priori estimates used in sample size calculations for cluster randomized trials (CRTs). We reviewed 300 CRTs published between 2000 and 2008. The prevalence of reporting sample size elements from the 2004 CONSORT recommendations was evaluated and a priori estimates compared with those observed in the trial. Of the 300 trials, 166 (55%) reported a sample size calculation. Only 36 of 166 (22%) reported all recommended descriptive elements. Elements specific to CRTs were the worst reported: a measure of within-cluster correlation was specified in only 58 of 166 (35%). Only 18 of 166 articles (11%) reported both a priori and observed within-cluster correlation values. Except in two cases, observed within-cluster correlation values were either close to or less than a priori values. Even with the CONSORT extension for cluster randomization, the reporting of sample size elements specific to these trials remains below that necessary for transparent reporting. Journal editors and peer reviewers should implement stricter requirements for authors to follow CONSORT recommendations. Authors should report observed and a priori within-cluster correlation values to enable comparisons between these over a wider range of trials. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Explorations in statistics: the log transformation.

PubMed

Curran-Everett, Douglas

2018-06-01

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This thirteenth installment of Explorations in Statistics explores the log transformation, an established technique that rescales the actual observations from an experiment so that the assumptions of some statistical analysis are better met. A general assumption in statistics is that the variability of some response Y is homogeneous across groups or across some predictor variable X. If the variability-the standard deviation-varies in rough proportion to the mean value of Y, a log transformation can equalize the standard deviations. Moreover, if the actual observations from an experiment conform to a skewed distribution, then a log transformation can make the theoretical distribution of the sample mean more consistent with a normal distribution. This is important: the results of a one-sample t test are meaningful only if the theoretical distribution of the sample mean is roughly normal. If we log-transform our observations, then we want to confirm the transformation was useful. We can do this if we use the Box-Cox method, if we bootstrap the sample mean and the statistic t itself, and if we assess the residual plots from the statistical model of the actual and transformed sample observations.

The Bologna complete sample of nearby radio sources. II. Phase referenced observations of faint nuclear sources

NASA Astrophysics Data System (ADS)

Liuzzo, E.; Giovannini, G.; Giroletti, M.; Taylor, G. B.

2009-10-01

Aims: To study statistical properties of different classes of sources, it is necessary to observe a sample that is free of selection effects. To do this, we initiated a project to observe a complete sample of radio galaxies selected from the B2 Catalogue of Radio Sources and the Third Cambridge Revised Catalogue (3CR), with no selection constraint on the nuclear properties. We named this sample “the Bologna Complete Sample” (BCS). Methods: We present new VLBI observations at 5 and 1.6 GHz for 33 sources drawn from a sample not biased toward orientation. By combining these data with those in the literature, information on the parsec-scale morphology is available for a total of 76 of 94 radio sources with a range in radio power and kiloparsec-scale morphologies. Results: The fraction of two-sided sources at milliarcsecond resolution is high (30%), compared to the fraction found in VLBI surveys selected at centimeter wavelengths, as expected from the predictions of unified models. The parsec-scale jets are generally found to be straight and to line up with the kiloparsec-scale jets. A few peculiar sources are discussed in detail. Tables 1-4 are only available in electronic form at http://www.aanda.org

High p-type doping, mobility, and photocarrier lifetime in arsenic-doped CdTe single crystals

NASA Astrophysics Data System (ADS)

Nagaoka, Akira; Kuciauskas, Darius; McCoy, Jedidiah; Scarpulla, Michael A.

2018-05-01

Group-V element doping is promising for simultaneously maximizing the hole concentration and minority carrier lifetime in CdTe for thin film solar cells, but there are roadblocks concerning point defects including the possibility of self-compensation by AX metastability. Herein, we report on doping, lifetime, and mobility of CdTe single crystals doped with As between 1016 and 1020 cm-3 grown from the Cd solvent by the travelling heater method. Evidence consistent with AX instability as a major contributor to compensation in samples doped below 1017 cm-3 is presented, while for higher-doped samples, precipitation of a second phase on planar structural defects is also observed and may explain spatial variation in properties such as lifetime. Rapid cooling after crystal growth increases doping efficiency and mobility for times up to 20-30 days at room temperature with the highest efficiencies observed close to 45% and a hole mobility of 70 cm2/Vs at room temperature. A doping limit in the low 1017/cm3 range is observed for samples quenched at 200-300 °C/h. Bulk minority carrier lifetimes exceeding 20 ns are observed for samples doped near 1016 cm-3 relaxed in the dark and for unintentionally doped samples, while a lifetime of nearly 5 ns is observed for 1018 cm-3 As doping. These results help us to establish limits on properties expected for group-V doped CdTe polycrystalline thin films for use in photovoltaics.

Mutagenicity in emissions from coal- and oil-fired boilers.

PubMed Central

Alfheim, I; Bergström, J G; Jenssen, D; Møller, M

1983-01-01

The mutagenicity of emission samples from three oil-fired and four coal-fired boilers have been compared by using the Salmonella/microsome assay. Very little or no mutagenic activity was observed in samples from five of these boilers. The sample from one oil-fired boiler showed mutagenic activity of about 500 revertants/MJ, and the sample from a coal-fired fluidized bed combustor had an activity of 58,000 revertants/MJ measured with strain TA 98 in the absence of metabolic activation. All samples contained substances that were cytotoxic to the test bacteria, thus making it difficult to obtain linear dose-response curves. Mutagenic activity at low levels may remain undetected due to this toxicity of the samples. Samples with mutagenic activity below the detection limit in the Salmonella test have also been tested for forward mutations at the HGPRT locus in V79 hamster cells. Weak mutagenic effects were detected in two of the samples, whereas the sample from one oil-fired boiler remained negative. In this test, as well as in the Salmonella test, a strong cytotoxic effect could be observed with all samples. PMID:6825617

Method for Operating a Sensor to Differentiate Between Analytes in a Sample

DOEpatents

Kunt, Tekin; Cavicchi, Richard E; Semancik, Stephen; McAvoy, Thomas J

1998-07-28

Disclosed is a method for operating a sensor to differentiate between first and second analytes in a sample. The method comprises the steps of determining a input profile for the sensor which will enhance the difference in the output profiles of the sensor as between the first analyte and the second analyte; determining a first analyte output profile as observed when the input profile is applied to the sensor; determining a second analyte output profile as observed when the temperature profile is applied to the sensor; introducing the sensor to the sample while applying the temperature profile to the sensor, thereby obtaining a sample output profile; and evaluating the sample output profile as against the first and second analyte output profiles to thereby determine which of the analytes is present in the sample.

Mass Spectrometry and Multiplex Antigen Assays to Assess Microbial Quality and Toxin Production of Staphylococcus aureus Strains Isolated from Clinical and Food Samples

PubMed Central

Attien, Paul; Sina, Haziz; Moussaoui, Wardi; Zimmermann-Meisse, Gaëlle; Dadié, Thomas; Keller, Daniel; Riegel, Philippe; Edoh, Vincent; Kotchoni, Simeon O.; Djè, Marcellin; Prévost, Gilles

2014-01-01

The aim of our study was to investigate the microbial quality of meat products and on some clinical samples in Abidjan focused on Staphylococcus genus and the toxin production profile of Staphylococcus aureus (S. aureus) isolated. Bacteria were collected from 240 samples of three meat products sold in Abidjan and 180 samples issued from clinical infections. The strains were identified by both microbiological and MALDI-TOF-MS methods. The susceptibility to antibiotics was determined by the disc diffusion method. The production of Panton-Valentine Leukocidin, LukE/D, and epidermolysins was screened using radial gel immunodiffusion. The production of staphylococcal enterotoxins and TSST-1 was screened by a Bio-Plex Assay. We observed that 96/240 of meat samples and 32/180 of clinical samples were contaminated by Staphylococcus. Eleven species were isolated from meats and 4 from clinical samples. Forty-two S. aureus strains were isolated from ours samples. Variability of resistance was observed for most of the tested antibiotics but none of the strains displays a resistance to imipenem and quinolones. We observed that 89% of clinical S. aureus were resistant to methicillin against 58% for those issued from meat products. All S. aureus isolates issued from meat products produce epidermolysins whereas none of the clinical strains produced these toxins. The enterotoxins were variably produced by both clinical and meat product samples. PMID:24987686

Room temperature luminescence and ferromagnetism of AlN:Fe

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

Li, H., E-mail: lihui@mail.iee.ac.cn, E-mail: wjwang@aphy.iphy.ac.cn; Cai, G. M.; Wang, W. J., E-mail: lihui@mail.iee.ac.cn, E-mail: wjwang@aphy.iphy.ac.cn

2016-06-15

AlN:Fe polycrystalline powders were synthesized by a modified solid state reaction (MSSR) method. Powder X-ray diffraction and transmission electron microscopy results reveal the single phase nature of the doped samples. In the doped AlN samples, Fe is in Fe{sup 2+} state. Room temperature ferromagnetic behavior is observed in AlN:Fe samples. Two photoluminescence peaks located at about 592 nm (2.09 eV) and 598 nm (2.07 eV) are observed in AlN:Fe samples. Our results suggest that AlN:Fe is a potential material for applications in spintronics and high power laser devices.

[Seroepidemiology of cholera in Mexico].

PubMed

González-Bonilla, C; Valle-Valdez, J G; Núñez-León, A; Moguel-Pech, L; Villanueva-Zamudio, A

1994-01-01

Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera. Samples from their contacts and from healthy people living in the same communities were also analyzed. Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples. An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera. Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year.

Transmission efficiency of the sigma virus in natural populations of its host, Drosophila melanogaster.

PubMed

Fleuriet, A

1982-01-01

A study of the viral samples collected in French natural populations of Drosophila melanogaster since 1969, indicates that natural populations include, as expected, both stabilized and non stabilized infected individuals. In agreement with previous observations made on other characters of the virus, the viral samples collected appear to be homogeneous for the efficiency of the hereditary transmission. However, this efficiency is greater than the average value observed with virus perpetuated in infected laboratory fly strains. One sample collected in Gabon and three in the U.S.A. appear to differ from the French samples for one at least of the traits studied in these experiments.

Sampling effort and estimates of species richness based on prepositioned area electrofisher samples

USGS Publications Warehouse

Bowen, Z.H.; Freeman, Mary C.

1998-01-01

Estimates of species richness based on electrofishing data are commonly used to describe the structure of fish communities. One electrofishing method for sampling riverine fishes that has become popular in the last decade is the prepositioned area electrofisher (PAE). We investigated the relationship between sampling effort and fish species richness at seven sites in the Tallapoosa River system, USA based on 1,400 PAE samples collected during 1994 and 1995. First, we estimated species richness at each site using the first-order jackknife and compared observed values for species richness and jackknife estimates of species richness to estimates based on historical collection data. Second, we used a permutation procedure and nonlinear regression to examine rates of species accumulation. Third, we used regression to predict the number of PAE samples required to collect the jackknife estimate of species richness at each site during 1994 and 1995. We found that jackknife estimates of species richness generally were less than or equal to estimates based on historical collection data. The relationship between PAE electrofishing effort and species richness in the Tallapoosa River was described by a positive asymptotic curve as found in other studies using different electrofishing gears in wadable streams. Results from nonlinear regression analyses indicted that rates of species accumulation were variable among sites and between years. Across sites and years, predictions of sampling effort required to collect jackknife estimates of species richness suggested that doubling sampling effort (to 200 PAEs) would typically increase observed species richness by not more than six species. However, sampling effort beyond about 60 PAE samples typically increased observed species richness by < 10%. We recommend using historical collection data in conjunction with a preliminary sample size of at least 70 PAE samples to evaluate estimates of species richness in medium-sized rivers. Seventy PAE samples should provide enough information to describe the relationship between sampling effort and species richness and thus facilitate evaluation of a sampling effort.

Effect of Co and O defects on ferromagnetism in Co-doped ZnO: An X-ray absorption spectroscopic investigation

NASA Astrophysics Data System (ADS)

Singhal, Rishi K.; Jakhar, Narendra; Samariya, A.; Dolia, S. N.; Kumar, Sudhish

2018-02-01

Understanding of origin of ferromagnetism in dilute magnetic oxides (DMO's) has become one of the most challenging research problems in condensed matter physics. Here we are reporting a detailed study of magnetic properties and electronic structure of two 5% Co-doped ZnO samples (the as-prepared sample Zn0.95Co0.05O and the hydrogenated sample Zn0.95Co0.05O:H). The as-prepared sample is found to be paramagnetic while through hydrogenation, we observed inducement of remarkable ferromagnetism in it. The H-mediated magnetic transition is accompanied by electronic structure modifications with no structural deviations. To get in-depth information into electronic structure correlations of the observed ferromagnetism, we have investigated their electronic properties in detail. For this purpose, we have employed the site-selective and element-sensitive X-ray-absorption spectroscopy (XAS) in the vicinity of the Cobalt L2,3 edge, the oxygen K edge, and the Zinc L3 edge using synchrotron radiation. The Co L2,3 edge spectra clearly show that Co dopants reside at the Zn sites for both these samples and that they are tetrahedrally coordinated with the ligand O atoms. Very minor changes are observed in the Zn L3 edge spectra. However, the O 1s edge spectra display dominant additional components in the ferromagnetic hydrogenated sample Zn0.95Co0.05O:H, not observed in the as-prepared non-magnetic sample Zn0.95Co0.05O. We conclude that the observed spectral features can be attributed to the presence of O vacancies and the hybridization of Co 3d states with O 2p vacancy states. These two factors together are likely to play important role in inducement of ferromagnetic ordering in this Co-doped ZnO system. However, which of these two weighs more in this mechanism, cannot be pinpointed and more studies are required in this regard.

A topological analysis of large-scale structure, studied using the CMASS sample of SDSS-III

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

Parihar, Prachi; Gott, J. Richard III; Vogeley, Michael S.

2014-12-01

We study the three-dimensional genus topology of large-scale structure using the northern region of the CMASS Data Release 10 (DR10) sample of the SDSS-III Baryon Oscillation Spectroscopic Survey. We select galaxies with redshift 0.452 < z < 0.625 and with a stellar mass M {sub stellar} > 10{sup 11.56} M {sub ☉}. We study the topology at two smoothing lengths: R {sub G} = 21 h {sup –1} Mpc and R {sub G} = 34 h {sup –1} Mpc. The genus topology studied at the R {sub G} = 21 h {sup –1} Mpc scale results in the highest genusmore » amplitude observed to date. The CMASS sample yields a genus curve that is characteristic of one produced by Gaussian random phase initial conditions. The data thus support the standard model of inflation where random quantum fluctuations in the early universe produced Gaussian random phase initial conditions. Modest deviations in the observed genus from random phase are as expected from shot noise effects and the nonlinear evolution of structure. We suggest the use of a fitting formula motivated by perturbation theory to characterize the shift and asymmetries in the observed genus curve with a single parameter. We construct 54 mock SDSS CMASS surveys along the past light cone from the Horizon Run 3 (HR3) N-body simulations, where gravitationally bound dark matter subhalos are identified as the sites of galaxy formation. We study the genus topology of the HR3 mock surveys with the same geometry and sampling density as the observational sample and find the observed genus topology to be consistent with ΛCDM as simulated by the HR3 mock samples. We conclude that the topology of the large-scale structure in the SDSS CMASS sample is consistent with cosmological models having primordial Gaussian density fluctuations growing in accordance with general relativity to form galaxies in massive dark matter halos.« less

Optical variability properties of the largest AGN sample observed with Kepler/K2

NASA Astrophysics Data System (ADS)

Aranzana, E.; Koerding, E.; Uttley, P.; Scaringi, S.; Steven, B.

2017-10-01

We present the first short time-scale ( hours to days) optical variability study of a large sample of Active Galactic Nuclei (AGN) observed with the Kepler/K2 mission. The sample contains 275 AGN observed over four campaigns with ˜30-minute cadence selected from the Million Quasar Catalogue with R magnitude < 19. We performed time series analysis to determine their variability properties by means of the power spectral densities (PSDs) and applied Monte Carlo techniques to find the best model parameters that fit the observed power spectra. A power-law model is sufficient to describe all the PSDs of the AGN in our sample. The average power-law slope is 2.5±0.5, steeper than the PSDs observed in X-rays, and the rest-frame amplitude variability in the frequency range of 6×10^{-6}-10^{-4} Hz varies from 1-10 % with an average of 2.6 %. We explore correlations between the variability amplitude and key parameters of the AGN, finding a significant correlation of rest-frame short-term variability amplitude with redshift, but no such correlation with luminosity. We attribute these effects to the known 'bluer when brighter variability of quasars combined with the fixed bandpass of Kepler. This study enables us to distinguish between Seyferts and Blazar and confirm AGN candidates.

The x ray properties of a large, uniform QSO sample: Einstein observations of the LBQS

NASA Technical Reports Server (NTRS)

Margon, B.; Anderson, S. F.; Xu, X.; Green, P. J.; Foltz, C. B.

1992-01-01

Although there are large numbers of Quasi Stellar Objects (QSO's) now observed in X rays, extensive X-ray observations of uniformly selected, 'complete' QSO samples are more rare. The Large Bright QSO Survey (LBQS) consists of about 1000 objects with well understood properties, most brighter than B = 18.8 and thus amenable to X-ray detections in relatively brief exposures. The sample is thought to be highly complete in the range 0.2 less than z less than 3.3, a significantly broader interval than many other surveys. The Einstein IPC observed 150 of these objects, mostly serendipitously, during its lifetime. We report the results of an analysis of these IPC data, considering not only the 20 percent of the objects we find to have positive X-ray detections, but also the ensemble X-ray properties derived by 'image stacking'.

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

Pern, F. J.; Glick, S. H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVA layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants.« less

Fundamental Properties of Co-moving Stars Observed by Gaia

NASA Astrophysics Data System (ADS)

Bochanski, John J.; Faherty, Jacqueline K.; Gagné, Jonathan; Nelson, Olivia; Coker, Kristina; Smithka, Iliya; Desir, Deion; Vasquez, Chelsea

2018-04-01

We have estimated fundamental parameters for a sample of co-moving stars observed by Gaia and identified by Oh et al. We matched the Gaia observations to the 2MASS and Wide-Field Infrared Survey Explorer catalogs and fit MIST isochrones to the data, deriving estimates of the mass, radius, [Fe/H], age, distance, and extinction to 9754 stars in the original sample of 10606 stars. We verify these estimates by comparing our new results to previous analyses of nearby stars, examining fiducial cluster properties, and estimating the power-law slope of the local present-day mass function. A comparison to previous studies suggests that our mass estimates are robust, while metallicity and age estimates are increasingly uncertain. We use our calculated masses to examine the properties of binaries in the sample and show that separation of the pairs dominates the observed binding energies and expected lifetimes.

Observations of cavity polaritons in one-dimensional photonic crystals containing a liquid-crystalline semiconductor based on perylene bisimide units

NASA Astrophysics Data System (ADS)

Sakata, T.; Suzuki, M.; Yamamoto, T.; Nakanishi, S.; Funahashi, M.; Tsurumachi, N.

2017-10-01

We investigated the optical transmission properties of one-dimensional photonic crystal (1D-PC) microcavity structures containing the liquid-crystalline (LC) perylene tetracarboxylic bisimide (PTCBI) derivative. We fabricated the microcavity structures for this study by two different methods and observed the cavity polaritons successfully in both samples. For one sample, since the PTCBI molecules were aligned in the cavity layer of the 1D-PC by utilizing a friction transfer method, vacuum Rabi splitting energy was strongly dependent on the polarization of the incident light produced by the peculiar optical features of the LC organic semiconductor. For the other sample, we did not utilize the friction transfer method and did not observe such polarization dependence. However, we did observe a relatively large Rabi splitting energy of 187 meV, probably due to the improvement of optical confinement effect.

The observation of the physicochemical change of rock under freeze-thawing experiment: CLSM, XRD and ICP analysis

NASA Astrophysics Data System (ADS)

Choi, J.; Chae, B.; Chon, C.; Jeong, J.

2013-12-01

Abstract : In order to understand the progress of the physical weathering of rock sample, we managed freeze-thawing experiment at temperature of up to 40C from -20C taking into account of South Korea. In this study, the time was held by two hours the temperature of the maximum (40C) and minimum (-20C) and the experiments were carried out at intervals of one hour rising and falling. We have run the experiment about 120 cycle with the cycle of -20C from 40C experiment. We measured the physical properties of rock samples after each 20 cycle has elapsed by using confocal laser scanning microscope (CLSM) and observed changes in roughness of rock samples surface. We also analyzed the mineral of rock sample using the XRD analysis and observing the change in chemical composition of solution used in the experiment by using ICP analysis. Through the above process, we observed physico-chemical changes in the rock sample due to freeze-thaw cycles. To analysis of the line roughness parameter we used set by the 10 vertical and horizontal cross section line on the surface and surface roughness parameter was analyzed by using the area on the surface. Through such a process, while the freeze-thawing experiment is advanced, it was studied how the physical roughness and chemical composition were changed. As a result, it was possible to observe a change in the mineral component of the particular dissolved in the solution and it was able to observe the characteristic changes of the parameters of the roughness of the lines and surfaces.

The ISO-IRAS Faint Galaxy Survey

NASA Technical Reports Server (NTRS)

Smith, Harding E.

1999-01-01

As part of the ISO-IRAS Faint Galaxy Survey ISO Satellite observations of over 600 IRAS sources have been obtained with the ISOCAM instrument. Because our survey strategy involved relatively short integrations, great care was required in developing analysis software including cosmic-ray and transient removal and calibration. These observations have now been through final pipeline processing at IPAC and ground-based follow-up is ongoing. The observations are for sources from two samples: a " Filler' sample selected to be at z greater than 0.1 and a fainter sample which selected for the highest redshift galaxies in the IRAS survey, with redshifts 0.2 less than z less than 1.0. I now have obtained ground-based follow-up spectrophotometry at Lick and Palomar observatories for 100 LFIRGs with 0.1 less than z less than 0.7. Our observations have confirmed that these systems are comparable to nearby LFIRGs such as Arp 220, with L (sub -)(fir) greater than 10(exp 11) L(sub -) sun and typically HII/Liner optical excitation. About 10% of the galaxies show true AGN (Sy2) excitation. Based on our work on a nearby complete sample of LFIRGS, we believe that the majority of these systems are luminous Starbursts, thus this project is tracing the luminous end of the galaxy star-forming luminosity function - the (infrared) star-formation history of the Universe to z approx. 1, a topic of some considerable recent interest. A by-product of these ISOCAM observations is approximately 1 square degree of deep 2 microns pointings outside the IRAS error boxes, allowing us an independent estimate of the mid-infrared log N - log S relation. Ground-based observations of this sample are continuing.

Where Do I Start (Beginning the Investigation)?

NASA Astrophysics Data System (ADS)

Kornacki, Jeffrey L.

No doubt some will open directly to this chapter, because your product is contaminated with an undesirable microbe, or perhaps you have been asked to do such an investigation for another company's facility not previously observed by you and naturally you want tips on how to find where the contaminant is getting into the product stream. This chapter takes the reader through the process of beginning the investigation including understanding the process including the production schedule and critically reviewing previously generated laboratory data. Understanding the critical control points and validity of their critical limits is also important. Scoping the extent of the problem is next. It is always a good idea for the factory to have a rigorously validated cleaning and sanitation procedure that provides a documented "sanitation breakpoint," which can be useful in the "scoping" process, although some contamination events may extend past these "break-points." Touring the facility is next wherein preliminary pre-selection of areas for future sampling can be done. Operational samples and observations in non-food contact areas can be taken at this time. Then the operations personnel need to be consulted and plans made for an appropriate amount of time to observe equipment break down for "post-operational" sampling and "pre-operational" investigational sampling. Hence the chapter further discusses preparing operations personnel for the disruptions that go along with these investigations and assembling the sampling team. The chapter concludes with a discussion of post-startup observations after an investigation and sampling.

The Pearson-Readhead Survey from Space

NASA Technical Reports Server (NTRS)

Preston, R. A.; Tingay, S. J.; Jones, D. L.; Lister, M.; Piner, G.; Murphy, D. W.; Meier, D. L.; Pearson, T. J.; Readhead, A. C. S.; Hirabayashi, H.;

Fission product release and microstructure changes of irradiated MOX fuel at high temperatures

NASA Astrophysics Data System (ADS)

Colle, J.-Y.; Hiernaut, J.-P.; Wiss, T.; Beneš, O.; Thiele, H.; Papaioannou, D.; Rondinella, V. V.; Sasahara, A.; Sonoda, T.; Konings, R. J. M.

2013-11-01

Samples of irradiated MOX fuel of 44.5 GWd/tHM mean burn-up were prepared by core drilling at three different radial positions of a fuel pellet. They were subsequently heated in a Knudsen effusion mass spectrometer up to complete vaporisation of the sample (˜2600 K) and the release of fission gas (krypton and xenon) as well as helium was measured. Scanning electron microscopy was used in parallel to investigate the evolution of the microstructure of a sample heated under the same condition up to given key temperatures as determined from the gas release profiles. A clear initial difference for fission gas release and microstructure was observed as a function of the radial position of the samples and therefore of irradiation temperature. A good correlation between the microstructure evolution and the gas release peaks could be established as a function of the temperature of irradiation and (laboratory) heating. The region closest to the cladding (0.58 < r/r0 < 0.96), designated as sample type A in Fig. 1. It represents the "cooler" part of the fuel pellet. The irradiation temperatures (Tirrad) in this range are from 854 to 1312 K (ΔT: 458 K). The intermediate radial zone of the pellet (0.42 < r/r0 < 0.81), designated sample type B in Fig. 1, has a Tirrad ranging from 1068 to 1434 K (ΔT: 365 K). The central zone of the pellet (0.003 < r/r0 < 0.41), designated sample type C in Fig. 1, which was close to the hottest part of the pellet, has a Tirrad ranging from 1442 to 1572 K (ΔT: 131 K). The sample irradiation temperatures were determined from the calculated temperature profile (exponential function) knowing the core temperature of the fuel (1573 K) [11], the standard temperature for this type of fuel at the inner side of the cladding (800 K). The average burnup was calculated with TRANSURANUS code [12] and the PA burnup is the average burnup multiplied by the ratio of the fissile Pu concentration in PA over average fissile Pu concentration in fuel [11]. Calculated burnups correspond reasonably well with measurement of Walker et al. [11]. All those data are shown Fig. 2.Fragments of 2-8 mg were chosen for the experiments. Since these specimens are small compared to the drilled sample size and were taken randomly, the precise radial position could not be determined, in particular the specimens of sample type, A and B could be from close radial locations.Specimens from each drilled sample type were annealed up to complete vaporisation (˜2600 K) at a speed of about 10 K min-1 in a Knudsen effusion mass spectrometer (KEMS) described previously [13,14]. In addition to helium and to the FGs all the species present in the vapour between 83 and 300 a.m.u. were measured during the heating. Additionally, the 85Kr isotope was analysed in a cold trap by β and γ counting. The long-lived fission gas isotopes correspond to masses 131, 132, 134 and 136 for Xe and 83, 84, 85 and 86 for Kr. The absolute quantities of gas released from specimens of sample types A and B were also determined using the in-house built Q-GAMES (Quantitative gas measurement system), described in detail in [15].For each of the samples, fragments were also annealed and measured in the KEMS up to specific temperatures corresponding to different stages of the FGs or He release. These fragments were subsequently analysed by Scanning Electron Microscopy (SEM, Philips XL40) [16] in order to investigate the relationship between structural changes, burn-up, irradiation temperature and fission products release. SEM observations were also done on the samples before the KEMS experiments and the fracture surface appearance of the samples is shown in Fig. 3, revealing the presence of the high burnup structure (HBS) in the Pu-rich agglomerates.A summary of the 12 samples analysed by KEMS, SEM and Q-GAMES is given in Table 1. At 1300 K no clear change potentially related to gas release appears in the UM and PA. At 1450 K a beginning of grain boundaries opening can be observed as well as rounding of the grains attributed to thermal etching. At 1600 K a densification is observed in the PA, smalls grains seem to agglomerate. At 1800 K grain coalescence has occurred in the PA together with formation of large pores. In the UM one observes the formation of a network of intergranular channels. Finally, at 2100 K re-sintering proceeds further and large intra-granular bubbles and five metal precipitates becomes visible. The micrographs of sample type B at 1700 K in Fig. 10, show the formation of small intergranular channel not observed on the image of the sample type A at 1600 K. At 2200 K the intragranular bubbles and intergranular channel are larger than for the sample type A at 2100 K.Images of sample type C (close to pellet centre) are shown in Fig. 11. The PAs did not show the typical HBS-like restructuring but rather loose (open) grains boundaries attributed to the high irradiation temperature. Also big cavities or very large grain boundaries of ˜10 μm were observed (picture 1). The same structure is observed for the UM. After heating at 1700 K, etching and channel formation at the grain boundaries is observed (pictures 3 and 4) similarly as observed for sample types A and B. At 2300 K the fuel was restructured through grain growth and formation of large cavities and intra-granular bubbles (pictures 5 and 6). No fragmentation of the sample has been observed as in very high burnup UO2 fuel [18].

Reducing Stimulus Overselectivity through an Increased Observing-Response Requirement

ERIC Educational Resources Information Center

Doughty, Adam H.; Hopkins, Michelle N.

2011-01-01

An adult with autism and a mild intellectual disability participated in a 0-s delayed matching-to-sample task. In each trial, two sample stimuli were presented together until the participant completed an observing-response requirement consisting of 1 or 10 mouse clicks in the baseline and experimental phases, respectively. One of the two sample…

Confidence intervals from single observations in forest research

Treesearch

Harry T. Valentine; George M. Furnival; Timothy G. Gregoire

1991-01-01

A procedure for constructing confidence intervals and testing hypothese from a single trial or observation is reviewed. The procedure requires a prior, fixed estimate or guess of the outcome of an experiment or sampling. Two examples of applications are described: a confidence interval is constructed for the expected outcome of a systematic sampling of a forested tract...

Fabrication of setup for high temperature thermal conductivity measurement.

PubMed

Patel, Ashutosh; Pandey, Sudhir K

2017-01-01

In this work, we report the fabrication of an experimental setup for high temperature thermal conductivity (κ) measurement. It can characterize samples with various dimensions and shapes. Steady state based axial heat flow technique is used for κ measurement. Heat loss is measured using parallel thermal conductance technique. Simple design, lightweight, and small size sample holder is developed by using a thin heater and limited components. Low heat loss value is achieved by using very low thermal conductive insulator block with small cross-sectional area. Power delivered to the heater is measured accurately by using 4-wire technique and for this, the heater is developed with 4 wires. This setup is validated by using Bi 0.36 Sb 1.45 Te 3 , polycrystalline bismuth, gadolinium, and alumina samples. The data obtained for these samples are found to be in good agreement with the reported data. The maximum deviation of 6% in the value κ is observed. This maximum deviation is observed with the gadolinium sample. We also report the thermal conductivity of polycrystalline tellurium from 320 K to 550 K and the nonmonotonous behavior of κ with temperature is observed.

Morphological diversity of Trichuris spp. eggs observed during an anthelminthic drug trial in Yunnan, China, and relative performance of parasitologic diagnostic tools.

PubMed

Steinmann, Peter; Rinaldi, Laura; Cringoli, Giuseppe; Du, Zun-Wei; Marti, Hanspeter; Jiang, Jin-Yong; Zhou, Hui; Zhou, Xiao-Nong; Utzinger, Jürg

2015-01-01

The presence of large Trichuris spp. eggs in human faecal samples is occasionally reported. Such eggs have been described as variant Trichuris trichiura or Trichuris vulpis eggs. Within the frame of a randomised controlled trial, faecal samples collected from 115 Bulang individuals from Yunnan, People's Republic of China were subjected to the Kato-Katz technique (fresh stool samples) and the FLOTAC and ether-concentration techniques (sodium acetate-acetic acid-formalin (SAF)-fixed stool samples). Large Trichuris spp. eggs were noted in faecal samples with a prevalence of 6.1% before and 21.7% after anthelminthic drug administration. The observed prevalence of standard-sized T. trichiura eggs was reduced from 93.0% to 87.0% after treatment. Considerably more cases of large Trichuris spp. eggs and slightly more cases with normal-sized T. trichiura eggs were identified by FLOTAC compared to the ether-concentration technique. No large Trichuris spp. eggs were observed on the Kato-Katz thick smears. Copyright © 2014 Elsevier B.V. All rights reserved.

The topology of large-scale structure. III - Analysis of observations

NASA Astrophysics Data System (ADS)

Gott, J. Richard, III; Miller, John; Thuan, Trinh X.; Schneider, Stephen E.; Weinberg, David H.; Gammie, Charles; Polk, Kevin; Vogeley, Michael; Jeffrey, Scott; Bhavsar, Suketu P.; Melott, Adrian L.; Giovanelli, Riccardo; Hayes, Martha P.; Tully, R. Brent; Hamilton, Andrew J. S.

1989-05-01

A recently developed algorithm for quantitatively measuring the topology of large-scale structures in the universe was applied to a number of important observational data sets. The data sets included an Abell (1958) cluster sample out to Vmax = 22,600 km/sec, the Giovanelli and Haynes (1985) sample out to Vmax = 11,800 km/sec, the CfA sample out to Vmax = 5000 km/sec, the Thuan and Schneider (1988) dwarf sample out to Vmax = 3000 km/sec, and the Tully (1987) sample out to Vmax = 3000 km/sec. It was found that, when the topology is studied on smoothing scales significantly larger than the correlation length (i.e., smoothing length, lambda, not below 1200 km/sec), the topology is spongelike and is consistent with the standard model in which the structure seen today has grown from small fluctuations caused by random noise in the early universe. When the topology is studied on the scale of lambda of about 600 km/sec, a small shift is observed in the genus curve in the direction of a 'meatball' topology.

The topology of large-scale structure. III - Analysis of observations. [in universe

NASA Technical Reports Server (NTRS)

Gott, J. Richard, III; Weinberg, David H.; Miller, John; Thuan, Trinh X.; Schneider, Stephen E.

1989-01-01

A recently developed algorithm for quantitatively measuring the topology of large-scale structures in the universe was applied to a number of important observational data sets. The data sets included an Abell (1958) cluster sample out to Vmax = 22,600 km/sec, the Giovanelli and Haynes (1985) sample out to Vmax = 11,800 km/sec, the CfA sample out to Vmax = 5000 km/sec, the Thuan and Schneider (1988) dwarf sample out to Vmax = 3000 km/sec, and the Tully (1987) sample out to Vmax = 3000 km/sec. It was found that, when the topology is studied on smoothing scales significantly larger than the correlation length (i.e., smoothing length, lambda, not below 1200 km/sec), the topology is spongelike and is consistent with the standard model in which the structure seen today has grown from small fluctuations caused by random noise in the early universe. When the topology is studied on the scale of lambda of about 600 km/sec, a small shift is observed in the genus curve in the direction of a 'meatball' topology.

Detachment of Tertiary Dendrite Arms during Controlled Directional Solidification in Aluminum - 7 wt Percent Silicon Alloys: Observations from Ground-based and Microgravity Processed Samples

NASA Technical Reports Server (NTRS)

Grugel, Richard N.; Erdman, Robert; Van Hoose, James R.; Tewari, Surendra; Poirier, David

2012-01-01

Electron Back Scattered Diffraction results from cross-sections of directionally solidified aluminum 7wt% silicon alloys unexpectedly revealed tertiary dendrite arms that were detached and mis-oriented from their parent arm. More surprisingly, the same phenomenon was observed in a sample similarly processed in the quiescent microgravity environment aboard the International Space Station (ISS) in support of the joint US-European MICAST investigation. The work presented here includes a brief introduction to MICAST and the directional solidification facilities, and their capabilities, available aboard the ISS. Results from the ground-based and microgravity processed samples are compared and possible mechanisms for the observed tertiary arm detachment are suggested.

Fabrication of Large Domain YBa2Cu3O(x) for Magnetic Suspension Applications

NASA Technical Reports Server (NTRS)

Sengupta, S.; Corpus, J.; Gaines, J. R., Jr.; Todt, V. R.; Zhang, X.; Miller, D. J.

1996-01-01

Large domain YBa2Cu3O(x) levitators have been fabricated using a seeded melt processing technique. Depending upon the seed, either a single or five domained sample can be obtained. The grain boundaries separating each domains in the five domain levitator are found to be 90 degrees. Similar levitation forces can be observed for single and five domained samples. After thermal cycling, however, a small decrease in the levitation force of the five domain levitator was observed as a function of thermal cycles while nearly no change in force was observed in the single domain levitator. Finally, it is shown that both, single and five domain YBCO, behave similarly as a function of sample thickness.

Study of the Induced Anisotropy in Field Annealed Hitperm Alloys by Mössbauer Spectroscopy and Kerr Microscopy

NASA Astrophysics Data System (ADS)

Blázquez, J. S.; Marcin, J.; Andrejka, F.; Franco, V.; Conde, A.; Skorvanek, I.

2016-08-01

Samples of Fe39Co39Nb6B15Cu1 alloy were nanocrystallized under zero field annealing (ZF) and transverse field annealing (TF) conditions. A reduction in coercivity for TF samples with respect to ZF sample (16 and 45 A/m, respectively) is observed. Kerr microscopy images show a well-defined parallel domain structure, transversally oriented to the ribbon axis for the TF sample unlike for the ZF sample, for which a complex pattern is observed with large and small domains at the surface of the ribbon. Although Mössbauer spectra are clearly different for the two studied samples, Mössbauer studies confirm that there is no significant difference between the hyperfine field distributions of TF and ZF samples but only the relative intensity of the 2nd and 3rd lines A 23 (related to the angle between the gamma radiation and the magnetic moments, α). However, for TF annealed samples α = 90 deg ( A 23 = 4), indicating that the magnetic moments lay on the plane of the ribbon in agreement with the well-defined domain structure observed by Kerr microscopy, ZF annealed samples show A 23 = 1.8. This value is close to that of a random orientation ( A 23 = 2) but smaller, indicating a slight preference for out of plane orientations. Moreover, it is clearly smaller than that of the as-cast amorphous samples A 23 = 2.8, with a preference to in-plane orientations. The application of the law of approach to saturation yields a larger effect of the inhomogeneities in ZF sample with respect to TF one.

Histological observation on dental hard tissue irradiated by ultrashort-pulsed laser

NASA Astrophysics Data System (ADS)

Uchizono, Takeyuki; Awazu, Kunio; Igarashi, Akihiro; Kato, Junji; Hirai, Yoshito

2006-04-01

In the field of dentistry, effectiveness of USPL irradiation is researched because USPL has less thermal side effect to dental hard tissue. In this paper, we observed morphological change and optical change of dental hard tissue irradiated by USPL for discussing the safety and effectiveness of USPL irradiation to dental hard tissues. Irradiated samples were crown enamel and root dentin of bovine teeth. Lasers were Ti:sapphire laser, which had pulse duration (P d)of 130 fsec and pulse repetition rate (f) of 1kHz and wavelength (l) of 800nm, free electron laser (FEL), which had P d of 15 μsec and f of 10Hz and wavelength of 9.6μm, and Er:YAG laser, which had P d of 250 μsec and f of 10Hz and wavelength of 2.94μm. After laser irradiation, the sample surfaces and cross sections were examined with SEM and EDX. The optical change of samples was observed using FTIR. In SEM, the samples irradiated by USPL had sharp and accurate ablation with no crack and no carbonization. But, in FEL and Er:YAG laser, the samples has rough ablation with crack and carbonization. It was cleared that the P/Ca ratio of samples irradiated by USPL had same value as non-irradiated samples. There was no change in the IR absorption spectrum between samples irradiated by USPL and non-irradiated sample. But, they of samples irradiated by FEL and Er:YAG laser, however, had difference value as non-irradiated samples. These results showed that USPL might be effective to ablate dental hard tissue without thermal damage.

[Sequential sampling plans to Orthezia praelonga Douglas (Hemiptera: Sternorrhyncha, Ortheziidae) in citrus].

PubMed

Costa, Marilia G; Barbosa, José C; Yamamoto, Pedro T

2007-01-01

The sequential sampling is characterized by using samples of variable sizes, and has the advantage of reducing sampling time and costs if compared to fixed-size sampling. To introduce an adequate management for orthezia, sequential sampling plans were developed for orchards under low and high infestation. Data were collected in Matão, SP, in commercial stands of the orange variety 'Pêra Rio', at five, nine and 15 years of age. Twenty samplings were performed in the whole area of each stand by observing the presence or absence of scales on plants, being plots comprised of ten plants. After observing that in all of the three stands the scale population was distributed according to the contagious model, fitting the Negative Binomial Distribution in most samplings, two sequential sampling plans were constructed according to the Sequential Likelihood Ratio Test (SLRT). To construct these plans an economic threshold of 2% was adopted and the type I and II error probabilities were fixed in alpha = beta = 0.10. Results showed that the maximum numbers of samples expected to determine control need were 172 and 76 samples for stands with low and high infestation, respectively.

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

USGS Publications Warehouse

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

2008-01-01

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

Measurements of NaI(Tl) Electron Response: Comparison of Different Samples

NASA Astrophysics Data System (ADS)

Hull, Giulia; Choong, Woon-Seng; Moses, William W.; Bizarri, Gregory; Valentine, John D.; Payne, Stephen A.; Cherepy, Nerine J.; Reutter, Bryan W.

2009-02-01

This paper measures the sample to sample variation in the light yield proportionality of NaI(Tl), and so explores whether this is an invariant characteristic of the material or whether it depends on the chemical and physical properties of the tested samples. We report on the electron response of nine crystals of NaI(Tl), differing in shape, volume, age, manufacturer and quality. The proportionality has been measured at the SLYNCI facility in the energy range between 3.5 to 460 keV. We observe that while samples produced by the same manufacturer at approximately the same time have virtually identical electron response curves, there are significant sample to sample variations among crystals produced by different manufacturers or at different times. In an effort to correlate changes in the electron response with details of the scintillation mechanism, we characterized other scintillation properties, including the gamma response and the x-ray excited emission spectra and decay times, for the nine crystals. While sample to sample differences in these crystals were observed, we have been unable to identify the underlying fundamental mechanisms that are responsible for these differences.

(I Can't Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research.

PubMed

van Rijnsoever, Frank J

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: "random chance," which is based on probability sampling, "minimal information," which yields at least one new code per sampling step, and "maximum information," which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario.

Gas discharge plasma treatment of poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) for enhanced paint adhesion

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

Salapare, Hernando S., E-mail: hssalapare@up.edu.ph; Department of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Manila, Manila City 1000; College of Science, Pamantasan ng Lungsod ng Maynila, Intramuros, Manila City 1002

Low-energy hydrogen-ions and tetrafluoromethane-ions produced from a gas discharge ion source were irradiated to poly(ethylene glycol-co-1,3/1,4 cyclohexanedimethanol terephthalate) (PETG) sheets for enhancing paint adhesion. The ion beams were characterized using a cast steel mass spectrometer, while the untreated and treated samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurements, and profilometry. The paint adhesion was determined by using the standard method for evaluating adhesion by knife [ASTM D6677-07, Standard Test Method for Evaluating Adhesion by Knife (ASTM International, West Conshohocken, PA, 2012)] and was correlated with the calculation of the work of adhesion derived frommore » the Young–Dupré equation. After plasma treatment, a significant decrease in the contact angle was observed in all samples, except for the CF{sub 4} ion-treated samples with the discharge current of 3 mA and an irradiation time of 30 min. At longer irradiation times, the treated samples showed lesser changes in the contact angle measurement. The increase in the average and root-mean-square surface roughness was observed on the samples after plasma treatment. The samples treated with either H{sub 2} or CF{sub 4} ions for 15 min showed a direct correlation between the discharge current and surface roughness. The samples treated for 30 min showed no significant correlation between the surface roughness and discharge current, which can be attributed to the possible melting of the samples since PETG has a low melting point. The observation made in this study on the relationship of wettability and surface roughness is consistent with the Wenzel wetting mode. Scanning electron micrographs showed surface etching on the hydrogen ion-treated samples while no significant surface changes were observed for the CF{sub 4} ion-treated samples. In general, paint adhesion was stronger for samples that exhibited enhanced wettability and high work of adhesion. The optimal work of adhesion to double the paint adhesion performance was at least 84.79 mN/m. The increase in the surface roughness after the treatment provided an increased friction between the paint and the PETG surface. The increase in the paint adhesion was also due to the covalent, hydrogen, and van der Waals bonding that are typically observed for highly wettable surfaces.« less

A novel approach to Lagrangian sampling of marine boundary layer cloud and aerosol in the northeast Pacific: case studies from CSET

NASA Astrophysics Data System (ADS)

Mohrmann, J.; Albrecht, B. A.; Bretherton, C. S.; Ghate, V. P.; Zuidema, P.; Wood, R.

2015-12-01

The Cloud System Evolution in the Trades (CSET) field campaign took place during July/August 2015 with the purpose of characterizing the cloud, aerosol and thermodynamic properties of the northeast Pacific marine boundary layer. One major science goal of the campaign was to observe a Lagrangian transition from thin stratocumulus (Sc) upwind near California to trade cumulus (Cu) nearer to Hawaii. Cloud properties were observed from the NSF/NCAR Gulfstream V research plane (GV) using the HIAPER Cloud Radar (HCR) and the HIAPER Spectral Resolution Lidar (HSRL), among other instrumentation. Aircraft observations were complemented by a suite of satellite-derived products. To observe a the evolution of airmasses over the course of two days, upwind regions were sampled on an outbound flight to from Sacramento, CA, to Kona, HI. The sampled airmasses were then tracked using HYSPLIT trajectories based on GFS model forecasts, and the return flight to California was planned to intercept those airmasses, using satellite observation to track cloud evolution in the interim. This approach required that trajectories were reasonably stable up to 3 days prior to final sampling, and also that forecast trajectories were in agreement with post-flight analysis and visual cloud feature tracking. The extent to which this was realised, and hence the validity of this new approach to Lagrangian airmass observation, is assessed here. We also present results showing that a Sc-Cu airmass transition was consistently observed during the CSET study using measurements from research flights and satellite.

Comparative study of He bubble formation in nanostructured reduced activation steel and its coarsen-grained counterpart

NASA Astrophysics Data System (ADS)

Liu, W. B.; Zhang, J. H.; Ji, Y. Z.; Xia, L. D.; Liu, H. P.; Yun, D.; He, C. H.; Zhang, C.; Yang, Z. G.

2018-03-01

High temperature (550 °C) He ions irradiation was performed on nanostructured (NS) and coarsen-grained (CG) reduced activation steel to investigate the effects of GBs/interfaces on the formation of bubbles during irradiation. Experimental results showed that He bubbles were preferentially trapped at dislocations and/or grain boundaries (GBs) for both of the samples. Void denuded zones (VDZs) were observed in the CG samples, while VDZs near GBs were unobvious in NS sample. However, both the average bubble size and the bubble density in peak damage region of the CG sample were significantly larger than that observed in the NS sample, which indicated that GBs play an important role during the irradiation, and the NS steel had better irradiation resistance than its CG counterpart.

Surface characterization of Nb samples electropolished together with real superconducting rf accelerator cavities

DOE PAGES

Xin Zhao; Geng, Rong -Li; Tyagi, P. V.; ...

2010-12-30

Here, we report the results of surface characterizations of niobium (Nb) samples electropolished together with a single cell superconducting radio-frequency accelerator cavity. These witness samples were located in three regions of the cavity, namely at the equator, the iris and the beam-pipe. Auger electron spectroscopy (AES) was utilized to probe the chemical composition of the topmost four atomic layers. Scanning electron microscopy with energy dispersive X-ray for elemental analysis (SEM/EDX) was used to observe the surface topography and chemical composition at the micrometer scale. A few atomic layers of sulfur (S) were found covering the samples non-uniformly. Niobium oxide granulesmore » with a sharp geometry were observed on every sample. Some Nb-O granules appeared to also contain sulfur.« less

Inner and outer star forming regions over the disks of spiral galaxies. I. Sample characterization

NASA Astrophysics Data System (ADS)

Rodríguez-Baras, M.; Díaz, A. I.; Rosales-Ortega, F. F.; Sánchez, S. F.

2018-01-01

Context. The knowledge of abundance distributions is central to understanding the formation and evolution of galaxies. Most of the relations employed for the derivation of gas abundances have so far been derived from observations of outer disk H ii regions, despite the known differences between inner and outer regions. Aims: Using integral field spectroscopy (IFS) observations we aim to perform a systematic study and comparison of two inner and outer H ii regions samples. The spatial resolution of the IFS, the number of objects and the homogeneity and coherence of the observations allow a complete characterization of the main observational properties and differences of the regions. Methods: We analyzed a sample of 725 inner H ii regions and a sample of 671 outer H ii regions, all of them detected and extracted from the observations of a sample of 263 nearby, isolated, spiral galaxies observed by the CALIFA survey. Results: We find that inner H ii regions show smaller equivalent widths, greater extinction and luminosities, along with greater values of [N ii] λ6583/Hα and [O ii] λ3727/[O iii] λ5007 emission-line ratios, indicating higher metallicities and lower ionization parameters. Inner regions have also redder colors and higher photometric and ionizing masses, although MionMphot is slighty higher for the outer regions. Conclusions: This work shows important observational differences between inner and outer H ii regions in star forming galaxies not previously studied in detail. These differences indicate that inner regions have more evolved stellar populations and are in a later evolution state with respect to outer regions, which goes in line with the inside-out galaxy formation paradigm. Table 4 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A102

Particle emission from artificial cometary materials

NASA Technical Reports Server (NTRS)

Koelzer, Gabriele; Kochan, Hermann; Thiel, Klaus

1992-01-01

During KOSI (comet simulation) experiments, mineral-ice mixtures are observed in simulated space conditions. Emission of ice-/dust particles from the sample surface is observed by means of different devices. The particle trajectories are recorded with a video system. In the following analysis we extracted the parameters: particle count rate, spatial distribution of starting points on the sample surface, and elevation angle and particle velocity at distances up to 5 cm from the sample surface. Different kinds of detectors are mounted on a frame in front of the sample to register the emitted particles and to collect their dust residues. By means of these instruments the particle count rates, the particle sizes and the composition of the particles can be correlated. The results are related to the gas flux density and the temperature on the sample surface during the insolation period. The particle emission is interpreted in terms of phenomena on the sample surface, e.g., formation of a dust mantle.

A study on Improvisation in a Musical performance using Multifractal Detrended Cross Correlation Analysis

NASA Astrophysics Data System (ADS)

Sanyal, Shankha; Banerjee, Archi; Patranabis, Anirban; Banerjee, Kaushik; Sengupta, Ranjan; Ghosh, Dipak

2016-11-01

MFDFA (the most rigorous technique to assess multifractality) was performed on four Hindustani music samples played on same 'raga' sung by the same performer. Each music sample was divided into six parts and 'multifractal spectral width' was determined for each part corresponding to the four samples. The results obtained reveal that different parts of all the four sound signals possess spectral width of widely varying values. This gives a cue of the so called 'musical improvisation' in all music samples, keeping in mind they belong to the bandish part of the same raga. Formal compositions in Hindustani raga are juxtaposed with the improvised portions, where an artist manoeuvers his/her own creativity to bring out a mood that is specific for that particular performance, which is known as 'improvisation'. Further, this observation hints at the association of different emotions even in the same bandish of the same raga performed by the same artist, this interesting observation cannot be revealed unless rigorous non-linear technique explores the nature of musical structure. In the second part, we applied MFDXA technique to explore more in-depth about 'improvisation' and association with emotion. This technique is applied to find the degree of cross-correlation (γx) between the different parts of the samples. Pronounced correlation has been observed in the middle parts of the all the four samples evident from higher values of γx ​whereas the other parts show weak correlation. This gets further support from the values of spectral width from different parts of the sample - width of those parts is significantly different from other parts. This observation is extremely new both in respect of musical structure of so called improvisation and associated emotion. The importance of this study in application area of cognitive music therapy is immense.

ADAPTIVE MATCHING IN RANDOMIZED TRIALS AND OBSERVATIONAL STUDIES

PubMed Central

van der Laan, Mark J.; Balzer, Laura B.; Petersen, Maya L.

2014-01-01

SUMMARY In many randomized and observational studies the allocation of treatment among a sample of n independent and identically distributed units is a function of the covariates of all sampled units. As a result, the treatment labels among the units are possibly dependent, complicating estimation and posing challenges for statistical inference. For example, cluster randomized trials frequently sample communities from some target population, construct matched pairs of communities from those included in the sample based on some metric of similarity in baseline community characteristics, and then randomly allocate a treatment and a control intervention within each matched pair. In this case, the observed data can neither be represented as the realization of n independent random variables, nor, contrary to current practice, as the realization of n/2 independent random variables (treating the matched pair as the independent sampling unit). In this paper we study estimation of the average causal effect of a treatment under experimental designs in which treatment allocation potentially depends on the pre-intervention covariates of all units included in the sample. We define efficient targeted minimum loss based estimators for this general design, present a theorem that establishes the desired asymptotic normality of these estimators and allows for asymptotically valid statistical inference, and discuss implementation of these estimators. We further investigate the relative asymptotic efficiency of this design compared with a design in which unit-specific treatment assignment depends only on the units’ covariates. Our findings have practical implications for the optimal design and analysis of pair matched cluster randomized trials, as well as for observational studies in which treatment decisions may depend on characteristics of the entire sample. PMID:25097298

Atmospheric measurement of point source fossil fuel CO2 emissions

NASA Astrophysics Data System (ADS)

Turnbull, J. C.; Keller, E. D.; Baisden, W. T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2013-11-01

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m a.g.l. We also determined the surface CO2ff content averaged over several weeks from the 14CO2 content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~1 week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14CO2 sampling strategies.

Atmospheric measurement of point source fossil CO2 emissions

NASA Astrophysics Data System (ADS)

Turnbull, J. C.; Keller, E. D.; Baisden, T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2014-05-01

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m above ground level. We also determined the surface CO2ff content averaged over several weeks from the 14C content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~ one week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14C sampling strategies.

The Evolution of Interstellar Medium Mass Probed by Dust Emission: ALMA Observations at z = 0.3-2

NASA Astrophysics Data System (ADS)

Scoville, N.; Aussel, H.; Sheth, K.; Scott, K. S.; Sanders, D.; Ivison, R.; Pope, A.; Capak, P.; Vanden Bout, P.; Manohar, S.; Kartaltepe, J.; Robertson, B.; Lilly, S.

2014-03-01

The use of submillimeter dust continuum emission to probe the mass of interstellar dust and gas in galaxies is empirically calibrated using samples of local star-forming galaxies, Planck observations of the Milky Way, and high-redshift submillimeter galaxies. All of these objects suggest a similar calibration, strongly supporting the view that the Rayleigh-Jeans tail of the dust emission can be used as an accurate and very fast probe of the interstellar medium (ISM) in galaxies. We present ALMA Cycle 0 observations of the Band 7 (350 GHz) dust emission in 107 galaxies from z = 0.2 to 2.5. Three samples of galaxies with a total of 101 galaxies were stellar-mass-selected from COSMOS to have M * ~= 1011 M ⊙: 37 at z ~ 0.4, 33 at z ~ 0.9, and 31 at z = 2. A fourth sample with six infrared-luminous galaxies at z = 2 was observed for comparison with the purely mass-selected samples. From the fluxes detected in the stacked images for each sample, we find that the ISM content has decreased by a factor ~6 from 1 to 2 × 1010 M ⊙ at both z = 2 and 0.9 down to ~2 × 109 M ⊙ at z = 0.4. The infrared-luminous sample at z = 2 shows a further ~4 times increase in M ISM compared with the equivalent non-infrared-bright sample at the same redshift. The gas mass fractions are ~2% ± 0.5%, 12% ± 3%, 14% ± 2%, and 53% ± 3% for the four subsamples (z = 0.4, 0.9, and 2 and infrared-bright galaxies).

Occupancy models for monitoring marine fish: a bayesian hierarchical approach to model imperfect detection with a novel gear combination.

PubMed

Coggins, Lewis G; Bacheler, Nathan M; Gwinn, Daniel C

2014-01-01

Occupancy models using incidence data collected repeatedly at sites across the range of a population are increasingly employed to infer patterns and processes influencing population distribution and dynamics. While such work is common in terrestrial systems, fewer examples exist in marine applications. This disparity likely exists because the replicate samples required by these models to account for imperfect detection are often impractical to obtain when surveying aquatic organisms, particularly fishes. We employ simultaneous sampling using fish traps and novel underwater camera observations to generate the requisite replicate samples for occupancy models of red snapper, a reef fish species. Since the replicate samples are collected simultaneously by multiple sampling devices, many typical problems encountered when obtaining replicate observations are avoided. Our results suggest that augmenting traditional fish trap sampling with camera observations not only doubled the probability of detecting red snapper in reef habitats off the Southeast coast of the United States, but supplied the necessary observations to infer factors influencing population distribution and abundance while accounting for imperfect detection. We found that detection probabilities tended to be higher for camera traps than traditional fish traps. Furthermore, camera trap detections were influenced by the current direction and turbidity of the water, indicating that collecting data on these variables is important for future monitoring. These models indicate that the distribution and abundance of this species is more heavily influenced by latitude and depth than by micro-scale reef characteristics lending credence to previous characterizations of red snapper as a reef habitat generalist. This study demonstrates the utility of simultaneous sampling devices, including camera traps, in aquatic environments to inform occupancy models and account for imperfect detection when describing factors influencing fish population distribution and dynamics.

Occupancy Models for Monitoring Marine Fish: A Bayesian Hierarchical Approach to Model Imperfect Detection with a Novel Gear Combination

PubMed Central

Coggins, Lewis G.; Bacheler, Nathan M.; Gwinn, Daniel C.

2014-01-01

Occupancy models using incidence data collected repeatedly at sites across the range of a population are increasingly employed to infer patterns and processes influencing population distribution and dynamics. While such work is common in terrestrial systems, fewer examples exist in marine applications. This disparity likely exists because the replicate samples required by these models to account for imperfect detection are often impractical to obtain when surveying aquatic organisms, particularly fishes. We employ simultaneous sampling using fish traps and novel underwater camera observations to generate the requisite replicate samples for occupancy models of red snapper, a reef fish species. Since the replicate samples are collected simultaneously by multiple sampling devices, many typical problems encountered when obtaining replicate observations are avoided. Our results suggest that augmenting traditional fish trap sampling with camera observations not only doubled the probability of detecting red snapper in reef habitats off the Southeast coast of the United States, but supplied the necessary observations to infer factors influencing population distribution and abundance while accounting for imperfect detection. We found that detection probabilities tended to be higher for camera traps than traditional fish traps. Furthermore, camera trap detections were influenced by the current direction and turbidity of the water, indicating that collecting data on these variables is important for future monitoring. These models indicate that the distribution and abundance of this species is more heavily influenced by latitude and depth than by micro-scale reef characteristics lending credence to previous characterizations of red snapper as a reef habitat generalist. This study demonstrates the utility of simultaneous sampling devices, including camera traps, in aquatic environments to inform occupancy models and account for imperfect detection when describing factors influencing fish population distribution and dynamics. PMID:25255325

Modeling the uncertainty of estimating forest carbon stocks in China

NASA Astrophysics Data System (ADS)

Yue, T. X.; Wang, Y. F.; Du, Z. P.; Zhao, M. W.; Zhang, L. L.; Zhao, N.; Lu, M.; Larocque, G. R.; Wilson, J. P.

2015-12-01

Earth surface systems are controlled by a combination of global and local factors, which cannot be understood without accounting for both the local and global components. The system dynamics cannot be recovered from the global or local controls alone. Ground forest inventory is able to accurately estimate forest carbon stocks at sample plots, but these sample plots are too sparse to support the spatial simulation of carbon stocks with required accuracy. Satellite observation is an important source of global information for the simulation of carbon stocks. Satellite remote-sensing can supply spatially continuous information about the surface of forest carbon stocks, which is impossible from ground-based investigations, but their description has considerable uncertainty. In this paper, we validated the Lund-Potsdam-Jena dynamic global vegetation model (LPJ), the Kriging method for spatial interpolation of ground sample plots and a satellite-observation-based approach as well as an approach for fusing the ground sample plots with satellite observations and an assimilation method for incorporating the ground sample plots into LPJ. The validation results indicated that both the data fusion and data assimilation approaches reduced the uncertainty of estimating carbon stocks. The data fusion had the lowest uncertainty by using an existing method for high accuracy surface modeling to fuse the ground sample plots with the satellite observations (HASM-SOA). The estimates produced with HASM-SOA were 26.1 and 28.4 % more accurate than the satellite-based approach and spatial interpolation of the sample plots, respectively. Forest carbon stocks of 7.08 Pg were estimated for China during the period from 2004 to 2008, an increase of 2.24 Pg from 1984 to 2008, using the preferred HASM-SOA method.

2D Models for the evolving distribution of impact melt at the lunar near-surface

NASA Astrophysics Data System (ADS)

Liu, T.; Michael, G. G.; Oberst, J.

2017-09-01

This study aims to investigate the cumulative effect of the impact gardening process. The lateral distribution of the melt with diverse ages is traced in this model. Using the observed distribution of melt age in lunar samples and meteorites, the possible scenarios of the lunar impact history can be discriminated. The record is also helpful for the future lunar sampling, guiding the choice of site to obtain samples from different impact basins, and to understand the mixture of melt ages observed at any one site.

Observation of high-order quantum resonances in the kicked rotor.

PubMed

Kanem, J F; Maneshi, S; Partlow, M; Spanner, M; Steinberg, A M

2007-02-23

Quantum resonances in the kicked rotor are characterized by a dramatically increased energy absorption rate, in stark contrast to the momentum localization generally observed. These resonances occur when the scaled Planck's constant Planck's [over ]=r/s 4pi, for any integers r and s. However, only the variant Planck's [over ]=r2pi resonances are easily observable. We have observed high-order quantum resonances (s>2) utilizing a sample of low energy, noncondensed atoms and a pulsed optical standing wave. Resonances are observed for variant Planck's [over ]=r/16 4pi for integers r=2-6. Quantum numerical simulations suggest that our observation of high-order resonances indicate a larger coherence length (i.e., coherence between different wells) than expected from an initially thermal atomic sample.

In vitro production of GHB in blood and serum samples under various storage conditions.

PubMed

Zörntlein, S W; Kopp, A; Becker, J; Kaufmann, T J; Röhrich, J; Urban, R

2012-01-10

The in vitro production of GHB was observed in freshly collected, untreated whole blood samples using glass BD-Vacutainers and polypropylene S-monovettes. GHB concentrations were determined daily over a period of one week and after 3, 6 and 9 weeks again. Furthermore, the GHB concentration in 40 untreated random whole blood samples stored at 4°C for a longer period of time (10 samples 12 month, 10 samples 24 month and 20 samples 36 month) was also determined. For comparison, the in vitro production of GHB in freshly collected and prepared serum samples was observed. GHB serum concentrations were determined three times over a period of one week and once again after six weeks. Sample preparation was performed by means of methanolic extraction following the precipitation of whole blood and serum samples. A methanolic standard calibration was done in a low range of 0.005-0.1 μg/mL (LOD: 0.004, LLOQ: 0.013). For quantification a spiked blood bank serum with a determined GHB concentration of 0.09 μg/mL was used. Corrected calibrations in the range of 0.09-5.09 μg/mL were used (LOD: 0.08 μg/mL, LLOQ: 0.30 μg/mL), recovery: 91.3% (high level: 4.09 μg/mL) 50.5% (low level: 0.19 μg/mL). Relevant elevation of GHB was observed in all whole blood samples stored in liquid form (4°C or room temperature). In two of the 40 whole blood samples stored over a longer period of time at 4°C, GHB concentrations in the range of 13 μg/mL were even determined. These findings constitute grounds for caution. Even a GHB cut-off level of 5 μg/mL cannot be considered as "absolutely positive" proof of a case of exogenous administration, at least in untreated liquid blood samples in long time storage. However, no significant elevations of GHB were otherwise observed in any of the serum samples independently of storage temperature nor in the whole blood samples that were frozen for storage. The results suggest that the cut-off for exogenous GHB of 5 μg/mL could be lowered significantly, with the consequence of winning valuable time for the potential victim, but only if serum is collected for GHB determination or if the whole blood sample is frozen immediately after collection and the procedure well documented. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Fluoride glass: Crystallization, surface tension

NASA Technical Reports Server (NTRS)

Doremus, R. H.

1988-01-01

Fluoride glass was levitated acoustically in the ACES apparatus on STS-11, and the recovered sample had a different microstructure from samples cooled in a container. Further experiments on levitated samples of fluoride glass are proposed. These include nucleation, crystallization, melting observations, measurement of surface tension of molten glass, and observation of bubbles in the glass. Ground experiments are required on sample preparation, outgassing, and surface reactions. The results should help in the development and evaluation of containerless processing, especially of glass, in the development of a contaminent-free method of measuring surface tensions of melts, in extending knowledge of gas and bubble behavior in fluoride glasses, and in increasing insight into the processing and properties of fluoride glasses.

Validation of a hospital-laboratory workstation for immunohematologic methods.

PubMed

Schoenfeld, Helge; Pretzel, Karin J; von Heymann, Christian; Neuner, Bruno; Kalus, Ulrich; Kiesewetter, Holger; Pruss, Axel

2010-01-01

The FREELYS Nano system (Diagast) is a manual workstation for ABO/D grouping, Rh phenotyping, K typing, and antibody screening (ABS) for immunoglobulin G (IgG) antibodies only and works with the erythrocyte-magnetized technology (EMT). The principle of EMT is based on magnetization of red blood cells and avoids centrifugation and washing steps. A total of 304 samples were tested with our routine blood bank methods, 100 samples for ABO/D grouping, 196 samples (100 at first evaluation, 96 at second evaluation) for Rh phenotyping and K typing (PK7200, Olympus), and 108 samples for ABS (DiaMed). All samples were tested in parallel with the FREELYS Nano. We found a 100% concordance between the observed (FREELYS Nano) and the expected (Olympus PK7200) results for ABO/D grouping in all 100 samples. For Rh phenotyping and K tests, in 24 of 100 samples false-positive reactions were observed in the first evaluation by the FREELYS Nano. After changing the test kit batch for Rh phenotyping by the manufacturer, a complete concordance in Rh phenotyping and K tests was observed in a second evaluation. For ABS, the FREELYS Nano showed in 4 of 108 samples (3.7%) false-negative reactions for IgG antibodies (two anti-K, one anti-E, one anti-C(w)), and one (0.9%) false-positive reaction. The FREELYS Nano is reliably suited to ABO/D grouping, Rh phenotyping, and K testing. The rate of false-negative reactions for IgG antibodies should be reduced.

Phenotypic Association Analyses With Copy Number Variation in Recurrent Depressive Disorder.

PubMed

Rucker, James J H; Tansey, Katherine E; Rivera, Margarita; Pinto, Dalila; Cohen-Woods, Sarah; Uher, Rudolf; Aitchison, Katherine J; Craddock, Nick; Owen, Michael J; Jones, Lisa; Jones, Ian; Korszun, Ania; Barnes, Michael R; Preisig, Martin; Mors, Ole; Maier, Wolfgang; Rice, John; Rietschel, Marcella; Holsboer, Florian; Farmer, Anne E; Craig, Ian W; Scherer, Stephen W; McGuffin, Peter; Breen, Gerome

2016-02-15

Defining the molecular genomic basis of the likelihood of developing depressive disorder is a considerable challenge. We previously associated rare, exonic deletion copy number variants (CNV) with recurrent depressive disorder (RDD). Sex chromosome abnormalities also have been observed to co-occur with RDD. In this reanalysis of our RDD dataset (N = 3106 cases; 459 screened control samples and 2699 population control samples), we further investigated the role of larger CNVs and chromosomal abnormalities in RDD and performed association analyses with clinical data derived from this dataset. We found an enrichment of Turner's syndrome among cases of depression compared with the frequency observed in a large population sample (N = 34,910) of live-born infants collected in Denmark (two-sided p = .023, odds ratio = 7.76 [95% confidence interval = 1.79-33.6]), a case of diploid/triploid mosaicism, and several cases of uniparental isodisomy. In contrast to our previous analysis, large deletion CNVs were no more frequent in cases than control samples, although deletion CNVs in cases contained more genes than control samples (two-sided p = .0002). After statistical correction for multiple comparisons, our data do not support a substantial role for CNVs in RDD, although (as has been observed in similar samples) occasional cases may harbor large variants with etiological significance. Genetic pleiotropy and sample heterogeneity suggest that very large sample sizes are required to study conclusively the role of genetic variation in mood disorders. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Optical, electrical and magnetic properties of nanostructured Mn3O4 synthesized through a facile chemical route

NASA Astrophysics Data System (ADS)

Bose, Vipin C.; Biju, V.

2015-02-01

Nanostructured Mn3O4 sample with an average crystallite size of ˜15 nm is synthesized via the reduction of potassium permanganate using hydrazine. The average particle size obtained from the Transmission Electron Microscopy analysis is in good agreement with the average crystallite size estimated from X-ray diffraction analysis. The presence of Mn4+ ions at the octahedral sites is inferred from the results of Raman, UV-visible absorption and X-ray photoelectron spectroscopy analyzes. DC electrical conductivity of the sample in the temperature range 313-423 K, is about five orders of magnitude larger than that reported for single crystalline Mn3O4 sample. The dominant conduction mechanism is identified to be of the polaronic hopping of holes between cations in the octahedral sites. The zero field cooled and field cooled magnetization of the sample is studied in the range 20-300 K. The Curie temperature for the sample is about 45 K, below which the sample is ferrimagnetic. A blocking temperature of 35 K is observed in the field cooled curve. It is observed that the sample shows hysteresis at temperatures below the Curie temperature with no saturation, even at an applied field (20 kOe). The presence of an ordered core and disordered surface of spin arrangements is observed from the magnetization studies. Above the Curie temperature, the sample shows linear dependence of magnetization on applied field with no hysteresis characteristic of paramagnetic phase.

Characterizing the temporal patterns of avian influenza virus introduction into Japan by migratory birds

PubMed Central

ONUMA, Manabu; KAKOGAWA, Masayoshi; YANAGISAWA, Masae; HAGA, Atsushi; OKANO, Tomomi; NEAGARI, Yasuko; OKANO, Tsukasa; GOKA, Koichi; ASAKAWA, Mitsuhiko

2017-01-01

The objectives of the present study were to observe the temporal pattern of avian influenza virus (AIV) introduction into Japan and to determine which migratory birds play an important role in introducing AIV. In total, 19,407 fecal samples from migratory birds were collected at 52 sites between October 2008 and May 2015. Total nucleic acids extracted from the fecal samples were subjected to reverse transcription loop–mediated isothermal amplification to detect viral RNA. Species identification of host migratory birds was conducted by DNA barcoding for positive fecal samples. The total number of positive samples was 352 (prevalence, 1.8%). The highest prevalence was observed in autumn migration, and a decrease in prevalence was observed. During autumn migration, central to southern Japan showed a prevalence higher than the overall prevalence. Thus, the main AIV entry routes may involve crossing the Sea of Japan and entry through the Korean Peninsula. Species identification was successful in 221 of the 352 positive samples. Two major species sequences were identified: the Mallard/Eastern Spot-billed duck group (115 samples; 52.0%) and the Northern pintail (61 samples; 27.6%). To gain a better understanding of the ecology of AIV in Japan and the introduction pattern of highly pathogenic avian influenza viruses, information regarding AIV prevalence by species, the prevalence of hatch-year migratory birds, migration patterns and viral subtypes in fecal samples using egg inoculation and molecular-based methods in combination is required. PMID:28484128

High p-type doping, mobility, and photocarrier lifetime in arsenic-doped CdTe single crystals

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

Nagaoka, Akira; Kuciauskas, Darius; McCoy, Jedidiah

Here, Group-V element doping is promising for simultaneously maximizing the hole concentration and minority carrier lifetime in CdTe for thin film solar cells, but there are roadblocks concerning point defects including the possibility of self-compensation by AX metastability. Herein, we report on doping, lifetime, and mobility of CdTe single crystals doped with As between 10 16 and 10 20 cm –3 grown from the Cd solvent by the travelling heater method. Evidence consistent with AX instability as a major contributor to compensation in samples doped below 10 17 cm –3 is presented, while for higher-doped samples, precipitation of a secondmore » phase on planar structural defects is also observed and may explain spatial variation in properties such as lifetime. Rapid cooling after crystal growth increases doping efficiency and mobility for times up to 20–30 days at room temperature with the highest efficiencies observed close to 45% and a hole mobility of 70 cm 2/Vs at room temperature. A doping limit in the low 10 17/cm 3 range is observed for samples quenched at 200–300 °C/h. Bulk minority carrier lifetimes exceeding 20 ns are observed for samples doped near 10 16 cm –3 relaxed in the dark and for unintentionally doped samples, while a lifetime of nearly 5 ns is observed for 10 18 cm –3 As doping. These results help us to establish limits on properties expected for group-V doped CdTe polycrystalline thin films for use in photovoltaics.« less

Estimation of Rainfall Sampling Uncertainty: A Comparison of Two Diverse Approaches

NASA Technical Reports Server (NTRS)

Steiner, Matthias; Zhang, Yu; Baeck, Mary Lynn; Wood, Eric F.; Smith, James A.; Bell, Thomas L.; Lau, William K. M. (Technical Monitor)

2002-01-01

The spatial and temporal intermittence of rainfall causes the averages of satellite observations of rain rate to differ from the "true" average rain rate over any given area and time period, even if the satellite observations are perfectly accurate. The difference of satellite averages based on occasional observation by satellite systems and the continuous-time average of rain rate is referred to as sampling error. In this study, rms sampling error estimates are obtained for average rain rates over boxes 100 km, 200 km, and 500 km on a side, for averaging periods of 1 day, 5 days, and 30 days. The study uses a multi-year, merged radar data product provided by Weather Services International Corp. at a resolution of 2 km in space and 15 min in time, over an area of the central U.S. extending from 35N to 45N in latitude and 100W to 80W in longitude. The intervals between satellite observations are assumed to be equal, and similar In size to what present and future satellite systems are able to provide (from 1 h to 12 h). The sampling error estimates are obtained using a resampling method called "resampling by shifts," and are compared to sampling error estimates proposed by Bell based on earlier work by Laughlin. The resampling estimates are found to scale with areal size and time period as the theory predicts. The dependence on average rain rate and time interval between observations is also similar to what the simple theory suggests.

Genotypic Diversity of Escherichia coli in the Water and Soil of Tropical Watersheds in Hawaii ▿

PubMed Central

Goto, Dustin K.; Yan, Tao

2011-01-01

High levels of Escherichia coli were frequently detected in tropical soils in Hawaii, which present important environmental sources of E. coli to water bodies. This study systematically examined E. coli isolates from water and soil of several watersheds in Hawaii and observed high overall genotypic diversity (35.5% unique genotypes). In the Manoa watershed, fewer than 9.3% of the observed E. coli genotypes in water and 6.6% in soil were shared between different sampling sites, suggesting the lack of dominant fecal sources in the watershed. High temporal variability of E. coli genotypes in soil was also observed, which suggests a dynamic E. coli population corresponding with the frequently observed high concentrations in tropical soils. When E. coli genotypes detected from the same sampling events were compared, limited sharing between the soil and water samples was observed in the majority of comparisons (73.5%). However, several comparisons reported up to 33.3% overlap of E. coli genotypes between soil and water, illustrating the potential for soil-water interactions under favorable environmental conditions. In addition, genotype accumulation curves for E. coli from water and soil indicated that the sampling efforts in the Manoa watershed could not exhaust the overall genotypic diversity. Comparisons of E. coli genotypes from other watersheds on Oahu, Hawaii, identified no apparent grouping according to sampling locations. The results of the present study demonstrate the complexity of using E. coli as a fecal indicator bacterium in tropical watersheds and highlight the need to differentiate environmental sources of E. coli from fecal sources in water quality monitoring. PMID:21515724

Effects of varying environmental conditions on emissivity spectra of bulk lunar soils: Application to Diviner thermal infrared observations of the Moon

NASA Astrophysics Data System (ADS)

Donaldson Hanna, K. L.; Greenhagen, B. T.; Patterson, W. R.; Pieters, C. M.; Mustard, J. F.; Bowles, N. E.; Paige, D. A.; Glotch, T. D.; Thompson, C.

2017-02-01

Currently, few thermal infrared measurements exist of fine particulate (<63 μm) analogue samples (e.g. minerals, mineral mixtures, rocks, meteorites, and lunar soils) measured under simulated lunar conditions. Such measurements are fundamental for interpreting thermal infrared (TIR) observations by the Diviner Lunar Radiometer Experiment (Diviner) onboard NASA's Lunar Reconnaissance Orbiter as well as future TIR observations of the Moon and other airless bodies. In this work, we present thermal infrared emissivity measurements of a suite of well-characterized Apollo lunar soils and a fine particulate (<25 μm) San Carlos olivine sample as we systematically vary parameters that control the near-surface environment in our vacuum chamber (atmospheric pressure, incident solar-like radiation, and sample cup temperature). The atmospheric pressure is varied between ambient (1000 mbar) and vacuum (<10-3 mbar) pressures, the incident solar-like radiation is varied between 52 and 146 mW/cm2, and the sample cup temperature is varied between 325 and 405 K. Spectral changes are characterized as each parameter is varied, which highlight the sensitivity of thermal infrared emissivity spectra to the atmospheric pressure and the incident solar-like radiation. Finally spectral measurements of Apollo 15 and 16 bulk lunar soils are compared with Diviner thermal infrared observations of the Apollo 15 and 16 sampling sites. This comparison allows us to constrain the temperature and pressure conditions that best simulate the near-surface environment of the Moon for future laboratory measurements and to better interpret lunar surface compositions as observed by Diviner.

High p-type doping, mobility, and photocarrier lifetime in arsenic-doped CdTe single crystals

DOE PAGES

Nagaoka, Akira; Kuciauskas, Darius; McCoy, Jedidiah; ...

2018-05-07

Here, Group-V element doping is promising for simultaneously maximizing the hole concentration and minority carrier lifetime in CdTe for thin film solar cells, but there are roadblocks concerning point defects including the possibility of self-compensation by AX metastability. Herein, we report on doping, lifetime, and mobility of CdTe single crystals doped with As between 10 16 and 10 20 cm –3 grown from the Cd solvent by the travelling heater method. Evidence consistent with AX instability as a major contributor to compensation in samples doped below 10 17 cm –3 is presented, while for higher-doped samples, precipitation of a secondmore » phase on planar structural defects is also observed and may explain spatial variation in properties such as lifetime. Rapid cooling after crystal growth increases doping efficiency and mobility for times up to 20–30 days at room temperature with the highest efficiencies observed close to 45% and a hole mobility of 70 cm 2/Vs at room temperature. A doping limit in the low 10 17/cm 3 range is observed for samples quenched at 200–300 °C/h. Bulk minority carrier lifetimes exceeding 20 ns are observed for samples doped near 10 16 cm –3 relaxed in the dark and for unintentionally doped samples, while a lifetime of nearly 5 ns is observed for 10 18 cm –3 As doping. These results help us to establish limits on properties expected for group-V doped CdTe polycrystalline thin films for use in photovoltaics.« less

Radiochemical sampling and analysis of shallow ground water and sediment at the BOMARC Missile Facility, east-central New Jersey, 1999-2000

USGS Publications Warehouse

Szabo, Zoltan; Zapecza, Otto S.; Oden, Jeannette H.; Rice, Donald E.

2005-01-01

A field sampling experiment was designed using low-flow purging with a portable pump and sample-collection equipment for the collection of water and sediment samples from observation wells screened in the Kirkwood-Cohansey aquifer system to determine radionuclide or trace-element concentrations for various size fractions. Selected chemical and physical characteristics were determined for water samples from observation wells that had not been purged for years. The sampling was designed to define any particulate, colloidal, and solution-phase associations of radionuclides or trace elements in ground water by means of filtration and ultrafiltration techniques. Turbidity was monitored and allowed to stabilize before samples were collected by means of the low-flow purging technique rather than by the traditional method of purging a fixed volume of water at high-flow rates from the observation well. A minimum of four water samples was collected from each observation well. The samples of water from each well were collected in the following sequence. (1) A raw unfiltered sample was collected within the first minutes of pumping. (2) A raw unfiltered sample was collected after at least three casing volumes of water were removed and turbidity stabilized. (3) A sample was collected after the water was filtered with a 0.45-micron filter. (4) A sample was collected after the water passed through a 0.45-micron filter and a 0.003-micron tangential-flow ultrafilter in sequence. In some cases, a fifth sample was collected after the water passed through a 0.45-micron filter and a 0.05-micron filter in sequence to test for colloids of 0.003 microns to 0.05 microns in size. The samples were analyzed for the concentration of manmade radionuclides plutonium-238 and -239 plus -240, and americium-241. The samples also were analyzed for concentrations of uranium-234, -235, and -238 to determine whether uranium-234 isotope enrichment (resulting from industrial processing) is present. A subset of samples was analyzed for concentrations of thorium-232, -230, and -228 to determine if thorium-228 isotope enrichment, also likely to result from industrial processing, is present. Concentrations of plutonium isotopes and americium-241 in the water samples were less than 0.1 picocurie per liter, the laboratory reporting level for these manmade radionuclides, with the exception of one americium-241 concentration from a filtered sample. A sequential split sample from the same well did not contain a detectable concentration of americium-241, however. Other filtered and unfiltered samples of water from the same well did not contain quantities of americium-241 nearly as high as 0.1 pCi/L. Therefore, the presence of americium-241 in a quantifiable concentration in water samples from this well could not be confirmed. Neither plutonium nor americium was detected in samples of settled sediment collected from the bottom of the wells. Concentrations of uranium isotopes (maximum of 0.05 and 0.08 picocuries per liter of uranium-238 and uranium-234, respectively) were measurable in unfiltered samples of turbid water from one well and in the settled bottom sediment from 6 wells (maximum concentrations of 0.25 and 0.20 picocuries per gram of uranium-238 and uranium-234, respectively). The uranium-234/uranium-238 isotopic ratio was near 1:1, which indicates natural uranium. The analytical results, therefore, indicate that no manmade radionuclide contamination is present in any of the well-bottom sediments, or unfiltered or filtered water samples from any of the sampled wells. No evidence of manmade radionuclide contamination was observed in the aquifer as settled or suspended particulates, colloids, or in the dissolved phase.

Statistical scaling of pore-scale Lagrangian velocities in natural porous media.

PubMed

Siena, M; Guadagnini, A; Riva, M; Bijeljic, B; Pereira Nunes, J P; Blunt, M J

2014-08-01

We investigate the scaling behavior of sample statistics of pore-scale Lagrangian velocities in two different rock samples, Bentheimer sandstone and Estaillades limestone. The samples are imaged using x-ray computer tomography with micron-scale resolution. The scaling analysis relies on the study of the way qth-order sample structure functions (statistical moments of order q of absolute increments) of Lagrangian velocities depend on separation distances, or lags, traveled along the mean flow direction. In the sandstone block, sample structure functions of all orders exhibit a power-law scaling within a clearly identifiable intermediate range of lags. Sample structure functions associated with the limestone block display two diverse power-law regimes, which we infer to be related to two overlapping spatially correlated structures. In both rocks and for all orders q, we observe linear relationships between logarithmic structure functions of successive orders at all lags (a phenomenon that is typically known as extended power scaling, or extended self-similarity). The scaling behavior of Lagrangian velocities is compared with the one exhibited by porosity and specific surface area, which constitute two key pore-scale geometric observables. The statistical scaling of the local velocity field reflects the behavior of these geometric observables, with the occurrence of power-law-scaling regimes within the same range of lags for sample structure functions of Lagrangian velocity, porosity, and specific surface area.

The micron- to kilometer-scale Moon: linking samples to orbital observations, Apollo to LRO

NASA Astrophysics Data System (ADS)

Crites, S.; Lucey, P. G.; Taylor, J.; Martel, L.; Sun, L.; Honniball, C.; Lemelin, M.

2017-12-01

The Apollo missions have shaped the field of lunar science and our understanding of the Moon, from global-scale revelations like the magma ocean hypothesis, to providing ground truth for compositional remote sensing and absolute ages to anchor cratering chronologies. While lunar meteorite samples can provide a global- to regional-level view of the Moon, samples returned from known locations are needed to directly link orbital-scale observations with laboratory measurements-a link that can be brought to full fruition with today's extremely high spatial resolution observations from Lunar Reconnaissance Orbiter and other recent missions. Korotev et al. (2005) described a scenario of the Moon without Apollo to speculate about our understanding of the Moon if our data were confined to lunar meteorites and remote sensing. I will review some of the major points discussed by Korotev et al. (2005), and focus on some of the ways in which spectroscopic remote sensing in particular has benefited from the Apollo samples. For example, could the causes and effects of lunar-style space weathering have been unraveled without the Apollo samples? What would be the limitations on remote sensing compositional measurements that rely on Apollo samples for calibration and validation? And what new opportunities to bring together orbital and sample analyses now exist, in light of today's high spatial and spectral resolution remote sensing datasets?

Application of the high throughput Attagene Factorial TM ...

EPA Pesticide Factsheets

Bioassays can be employed to evaluate the integrated effects of complex mixtures of both known and unidentified contaminants present in environmental samples. However, such methods have typically focused on one or a few pathways despite the fact that the chemicals in a mixture may exhibit a wide range of activities. High throughput toxicology approaches that can rapidly screen samples for a broad diversity of biological activities offer a means to provide a more comprehensive characterization of complex mixtures. To test this concept, twenty-four ambient water samples were collected, extracted, and screened for their ability to interact with or modulate over 80 different transcription factors using the Attagene FactorialTM platform utilized by the US EPA’s ToxCast Program. Samples evaluated included 10 water samples collected in varying proximity to a wastewater discharge into the St. Louis River, MN; water collected at five sites along a gradient centered on a wastewater discharge into the Maumee River, Ohio, USA; and eight samples collected in association with a nation-wide USGS surface streams study. For samples collected along the St. Louis River, the greatest number of biological activities were observed at locations closest to wastewater discharge with up to 13 endpoints responding. The Maumee River showed a gradient response in the number of observed activities, ranging from three positive responses observed far upstream of a wastewater discharge to 10

Sediment pore-water toxicity test results and preliminary toxicity identification of post-landfall pore-water samples collected following the Deepwater Horizon oil release, Gulf of Mexico, 2010

USGS Publications Warehouse

Biedenbach, James M.; Carr, Robert S.

2011-01-01

Pore water from coastal beach and marsh sediments from the northern Gulf of Mexico, pre- and post-landfall of the Deepwater Horizon oil release, were collected and evaluated for toxicity with the sea urchin fertilization and embryological development assays. There were 17 pre-landfall samples and 49 post-landfall samples tested using both assays. Toxicity was determined in four pre-landfall sites and in seven post-landfall sites in one or both assays as compared to a known reference sediment pore-water sample collected in Aransas Bay, Texas. Further analysis and testing of five of the post-landfall toxic samples utilizing Toxicity Identification Evaluation techniques indicated that ammonia, and to a lesser extent metals, contributed to most, if not all, of the observed toxicity in four of the five samples. Results of one sample (MS-39) indicated evidence that ammonia, metals, and non-ionic organics were contributing to the observed toxicity.

A simple modification of the Baermann method for diagnosis of strongyloidiasis.

PubMed

Hernández-Chavarría, F; Avendaño, L

2001-08-01

The diagnosis of Strongyloides stercoralis infections is routinely made by microscopic observation of larvae in stool samples, a low sensitivity method, or by other, most effective methods, such as the Baermann or agar culture plate methods. We propose in this paper a practical modification of Baermann method. One hundred and six stool samples from alcoholic patients were analyzed using the direct smear test, agar culture plate method, the standard Baermann method, and its proposed modification. For this modification the funnel used in the original version of the method is substituted by a test tube with a rubber stopper, perforated to allow insertion of a pipette tip. The tube with a fecal suspension is inverted over another tube containing 6 ml of saline solution and incubated at 37 degrees C for at least 2 h. The saline solution from the second tube is centrifuged and the pellet is observed microscopically. Larva of S. stercoralis were detected in six samples (5.7%) by the two versions of the Baermann method. Five samples were positive using the agar culture plate method, and only in two samples the larva were observed using direct microscopic observation of fecal smears. Cysts of Endolimax nana and Entamoeba histolytica/dyspar were also detected in the modification of Baermann method. Data obtained by the modified Baermann method suggest that this methodology may helps concentrate larvae of S. stercoralis as efficiently as the original method.

Observation of tritium in gas/plasma loaded titanium samples

NASA Astrophysics Data System (ADS)

Srinivasan, M.; Shyam, A.; Kaushik, T. C.; Rout, R. K.; Kulkarni, L. V.; Krishnan, M. S.; Malhotra, S. K.; Nagvenkar, V. G.; Iyengar, P. K.

1991-05-01

The observation of significant neutron yield from gas loaded titanium samples at Frascati in April 1989 opened up an alternate pathway to the investigation of anomalous nuclear phenomena in deuterium/solid systems, complimenting the electrolytic approach. Since then at least six different groups have successfully measured burst neutron emission from deuterated titanium shavings following the Frascati methodology, the special feature of which was the use of liquid nitrogen to create repeated thermal cycles resulting in the production of non-equilibrium conditions in the deuterated samples. At Trombay several variations of the gas loading procedure have been investigated including induction heating of single machined titanium targets in a glass chamber as well as use of a plasma focus device for deuteriding its central titanium electrode. Stemming from earlier observations both at BARC and elsewhere that tritium yield is ≂108 times higher than neutron output in cold fusion experiments, we have channelised our efforts to the search for tritium rather than neutrons. The presence of tritium in a variety gas/plasma loaded titanium samples has been established successfully through a direct measurement of the radiations emitted as a result of tritium decay, in contradistinction to other groups who have looked for tritium in the extracted gases. In some samples we have thus observed tritium levels of over 10 MBq with a corresponding (t/d) ratio of ≳10-5.

A three stage sampling model for remote sensing applications

NASA Technical Reports Server (NTRS)

Eisgruber, L. M.

1972-01-01

A conceptual model and an empirical application of the relationship between the manner of selecting observations and its effect on the precision of estimates from remote sensing are reported. This three stage sampling scheme considers flightlines, segments within flightlines, and units within these segments. The error of estimate is dependent on the number of observations in each of the stages.

Inference and sample size calculation for clinical trials with incomplete observations of paired binary outcomes.

PubMed

Zhang, Song; Cao, Jing; Ahn, Chul

2017-02-20

We investigate the estimation of intervention effect and sample size determination for experiments where subjects are supposed to contribute paired binary outcomes with some incomplete observations. We propose a hybrid estimator to appropriately account for the mixed nature of observed data: paired outcomes from those who contribute complete pairs of observations and unpaired outcomes from those who contribute either pre-intervention or post-intervention outcomes. We theoretically prove that if incomplete data are evenly distributed between the pre-intervention and post-intervention periods, the proposed estimator will always be more efficient than the traditional estimator. A numerical research shows that when the distribution of incomplete data is unbalanced, the proposed estimator will be superior when there is moderate-to-strong positive within-subject correlation. We further derive a closed-form sample size formula to help researchers determine how many subjects need to be enrolled in such studies. Simulation results suggest that the calculated sample size maintains the empirical power and type I error under various design configurations. We demonstrate the proposed method using a real application example. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The large sample size fallacy.

PubMed

Lantz, Björn

2013-06-01

Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article. The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research. Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself. Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature. © 2012 Nordic College of Caring Science.

Acute health effects of PM10 pollution on symptomatic and asymptomatic children

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

Pope, C.A. 3d.; Dockery, D.W.

1992-05-01

This study assessed the association between daily changes in respiratory health and respirable particulate pollution (PM10) in Utah Valley during the winter of 1990-1991. During the study period, 24-h PM10 concentrations ranged from 7 to 251 micrograms/m3. Participants included symptomatic and asymptomatic samples of fifth- and sixth-grade students. Relatively small but statistically significant (p less than 0.01) negative associations between peak expiratory flow (PEF) and PM10 were observed for both the symptomatic and asymptomatic samples. The association was strongest for the symptomatic children. Large associations between the incidence of respiratory symptoms, especially cough, and PM10 pollution were also observed formore » both samples. Again the association was strongest for the symptomatic sample. Immediate and delayed PM10 effects were observed. Respiratory symptoms and PEF changes were more closely associated with 5-day moving-average PM10 levels than with concurrent-day levels. These associations were also observed at PM10 levels below the 24-h standard of 150 micrograms/m3. This study indicates that both symptomatic and asymptomatic children may suffer acute health effects of respirable particulate pollution, with symptomatic children suffering the most.« less

The effect of clustering on lot quality assurance sampling: a probabilistic model to calculate sample sizes for quality assessments

PubMed Central

2013-01-01

Background Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. Results To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations. The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. Conclusions We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs. PMID:24160725

The effect of clustering on lot quality assurance sampling: a probabilistic model to calculate sample sizes for quality assessments.

PubMed

Hedt-Gauthier, Bethany L; Mitsunaga, Tisha; Hund, Lauren; Olives, Casey; Pagano, Marcello

2013-10-26

Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations.The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs.

Liquid Microjunction Surface Sampling Probe Fluid Dynamics: Computational and Experimental Analysis of Coaxial Intercapillary Positioning Effects on Sample Manipulation

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

ElNaggar, Mariam S; Barbier, Charlotte N; Van Berkel, Gary J

A coaxial geometry liquid microjunction surface sampling probe (LMJ-SSP) enables direct extraction of analytes from surfaces for subsequent analysis by techniques like mass spectrometry. Solution dynamics at the probe-to-sample surface interface in the LMJ-SSP has been suspected to influence sampling efficiency and dispersion but has not been rigorously investigated. The effect on flow dynamics and analyte transport to the mass spectrometer caused by coaxial retraction of the inner and outer capillaries from each other and the surface during sampling with a LMJ-SSP was investigated using computational fluid dynamics and experimentation. A transparent LMJ-SSP was constructed to provide the means formore » visual observation of the dynamics of the surface sampling process. Visual observation, computational fluid dynamics (CFD) analysis, and experimental results revealed that inner capillary axial retraction from the flush position relative to the outer capillary transitioned the probe from a continuous sampling and injection mode through an intermediate regime to sample plug formationmode caused by eddy currents at the sampling end of the probe. The potential for analytical implementation of these newly discovered probe operational modes is discussed.« less

Multiple category-lot quality assurance sampling: a new classification system with application to schistosomiasis control.

PubMed

Olives, Casey; Valadez, Joseph J; Brooker, Simon J; Pagano, Marcello

2012-01-01

Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS) have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa. We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n=15 and n=25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa. Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87). In three of the studies, the kappa-statistic for a design with n=15 was greater than 0.75. In the fourth study, where these designs performed poorly (kappa-statistic less than 0.50), the majority of observations fell in regions where potential error is known to be high. Employment of semi-curtailed and curtailed sampling further reduced the sample size by as many as 0.5 and 3.5 observations per school, respectively, without increasing classification error. This work provides the needed analytics to understand the properties of MC-LQAS for assessing the prevalance of S. mansoni and shows that in most settings a sample size of 15 children provides a reliable classification of schools.

Comparison of oral fluid collection methods for the molecular detection of hepatitis B virus.

PubMed

Portilho, M M; Mendonça, Acf; Marques, V A; Nabuco, L C; Villela-Nogueira, C A; Ivantes, Cap; Lewis-Ximenez, L L; Lampe, E; Villar, L M

2017-11-01

This study aims to compare the efficiency of four oral fluid collection methods (Salivette, FTA Card, spitting and DNA-Sal) to detect HBV DNA by qualitative PCR. Seventy-four individuals (32 HBV reactive and 42 with no HBV markers) donated serum and oral fluid. In-house qualitative PCR to detect HBV was used for both samples and commercial quantitative PCR for serum. HBV DNA was detected in all serum samples from HBV-infected individuals, and it was not detected in control group. HBV DNA from HBV group was detected in 17 samples collected with Salivette device, 16 samples collected by FTA Card device, 16 samples collected from spitting and 13 samples collected by DNA-Sal device. Samples that corresponded to a higher viral load in their paired serum sample could be detected using all oral fluid collection methods, but Salivette collection device yielded the largest numbers of positive samples and had a wide range of viral load that was detected. It was possible to detect HBV DNA using all devices tested, but higher number of positive samples was observed when samples were collected using Salivette device, which shows high concordance to viral load observed in the paired serum samples. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

Measurement of process-dependent material properties of pharmaceutical solids by nanoindentation.

PubMed

Liao, Xiangmin; Wiedmann, Timothy Scott

2005-01-01

The purpose of this work was to evaluate nanoindentation as a means to characterize the material properties of pharmaceutical solids. X-ray diffraction of potassium chloride and acetaminophen showed that samples prepared by cooling a melt to a crystalline sample as opposed to slow recrystallization had the same crystal structure. With analysis of the force-displacement curves, the KCl quenched samples had a hardness that was 10 times higher than the recrystallized KCl, while acetaminophen quenched samples were 25% harder than the recrystallized samples. The elastic moduli of the quenched samples were also much greater than that observed for the recrystallized samples. Although the elasticity was independent of load, the hardness increased with load for acetaminophen. With each sample, the flow at constant load increased with applied load. Etching patterns obtained by atomic force microscopy showed that the KCl quenched sample had a higher dislocation density than the recrystallized sample, although there was no evident difference in the acetaminophen samples. Overall, the differences in the observed sample properties may be related to the dislocation density. Thus, nanoindentation has been shown to be a sensitive method for determining a processed-induced change in the hardness, creep, and elasticity of KCl and acetaminophen. (c) 2004 Wiley-Liss, Inc.

XMM-Newton Proposal 03060602

NASA Astrophysics Data System (ADS)

Strickland, David

2004-10-01

We propose to observe 3 edge-on Milky-Way-like normal spiral galaxies in order to constrain the presence, properties and physical origin of hot gas in their halos, a topic about which relatively little is currently known. These observations will complete our sample of 8 edge-on normal spirals for which we have a wide range of existing observational data, so that all galaxies will have deep XMM-Newton and/or Chandra observations. With this sample we can assess the relative contribution to the halo X-ray emission of normal spirals from SNII-driven galactic fountains, accretion of primordial gas, and SNIa-driven outflows. The observations will robustly detect NGC 891-like hot halos, broadly quantify their properties, and can be used to constrain the efficiency of mechanical energy feedback.

Effect of time-varying tropospheric models on near-regional and regional infrasound propagation as constrained by observational data

NASA Astrophysics Data System (ADS)

McKenna, Mihan H.; Stump, Brian W.; Hayward, Chris

2008-06-01

The Chulwon Seismo-Acoustic Array (CHNAR) is a regional seismo-acoustic array with co-located seismometers and infrasound microphones on the Korean peninsula. Data from forty-two days over the course of a year between October 1999 and August 2000 were analyzed; 2052 infrasound-only arrivals and 23 seismo-acoustic arrivals were observed over the six week study period. A majority of the signals occur during local working hours, hour 0 to hour 9 UT and appear to be the result of cultural activity located within a 250 km radius. Atmospheric modeling is presented for four sample days during the study period, one in each of November, February, April, and August. Local meteorological data sampled at six hour intervals is needed to accurately model the observed arrivals and this data produced highly temporally variable thermal ducts that propagated infrasound signals within 250 km, matching the temporal variation in the observed arrivals. These ducts change dramatically on the order of hours, and meteorological data from the appropriate sampled time frame was necessary to interpret the observed arrivals.

Transporting children in wheelchairs in passenger vehicles: a comparison of best practice to observed and reported practice in a pilot sample.

PubMed

Yonkman, Janell; O'Neil, Joseph; Talty, Judith; Bull, Marilyn J

2010-01-01

We compared observed and reported practice among children with special health care needs transported in wheelchairs with the recommendations from the American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society of North America Committee on Wheelchairs and Transportation voluntary standards for best practice for using wheelchairs in vehicles. A convenience sample of vehicles exiting the garage of a children's hospital was observed. Certified child passenger safety technicians gathered driver demographics and the child's reported medical condition, weight, age, clinic visited, and relation to the driver. Technicians observed how the wheelchair and occupant were secured. A sample of 20 vehicles showed that 90% used four-point tie-down systems to secure the wheelchairs. A total of 88% of drivers tied the wheelchairs down correctly; only 20% used a separate lap-shoulder belts to secure the occupants. Twenty-five percent used lap trays, which are not recommended. Fifteen participants traveled with medical equipment secured inappropriately. Many deviations from best practice were observed and highlight areas for increased awareness, education, and resources for caregivers.

Nd: YAG laser irradiation effects on structural and magnetic properties of Ni1+xZrxFe2-2xO4 nanoparticles

NASA Astrophysics Data System (ADS)

Saraf, Tukaram S.; Kounsalye, Jitendra S.; Birajdar, Shankar D.; Shamkuwar, N. R.

2018-05-01

The effect of 112 mJ Nd: YAG laser irradiation on structural, morphological, infrared and magnetic properties of Ni1+xZrxFe2-2xO4 spinel ferrite nanoparticles has been systematically investigated in the present work. The sol-gel auto combustion synthesis method was successfully executed for the synthesis of the present system. All the samples were characterized by X-ray diffraction technique (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR) technique. The magnetic properties of the present samples were measured by pulse field hysteresis loop technique. All the properties were measured for laser irradiated samples as well, to understand the effect of irradiation on the properties. The single-phase cubic spinel structure was confirmed by X-ray diffraction patterns of all samples and the disordered structure was observed for irradiated samples. The two principle absorption bands in IR spectra also confirm the formation of the spinel structure. Spherical and agglomerated morphology was observed for Zr4+ substituted nickel ferrite, whereas scratched morphology was observed for the irradiated samples. The grain size confirms the nanocrystalline nature, the crystallite size also evident the same. The magnetic parameters decreased after Zr4+ ion doping and strongly influenced by the irradiation.

Interparticle interactions effects on the magnetic order in surface of FeO4 nanoparticles.

PubMed

Lima, E; Vargas, J M; Rechenberg, H R; Zysler, R D

2008-11-01

We report interparticle interactions effects on the magnetic structure of the surface region in Fe3O4 nanoparticles. For that, we have studied a desirable system composed by Fe3O4 nanoparticles with (d) = 9.3 nm and a narrow size distribution. These particles present an interesting morphology constituted by a crystalline core and a broad (approximately 50% vol.) disordered superficial shell. Two samples were prepared with distinct concentrations of the particles: weakly-interacting particles dispersed in a polymer and strongly-dipolar-interacting particles in a powder sample. M(H, T) measurements clearly show that strong dipolar interparticle interaction modifies the magnetic structure of the structurally disordered superficial shell. Consequently, we have observed drastically distinct thermal behaviours of magnetization and susceptibility comparing weakly- and strongly-interacting samples for the temperature range 2 K < T < 300 K. We have also observed a temperature-field dependence of the hysteresis loops of the dispersed sample that is not observed in the hysteresis loops of the powder one.

Quantitative assessment of groundwater quality using a biological indicator: some preliminary observations.

PubMed

Pfeil, R M; Venkat, J A; Plimmer, J R; Sham, S; Davis, K; Nair, P P

1994-02-01

The genotoxicity of groundwater was evaluated, using a novel application of the SOS microplate assay (SOSMA). Organic residues were extracted from groundwater samples from Maryland, Pennsylvania, and Delaware by using C-18 bonded silica solid phase extraction tubes. Total organic carbon content (TOC) of water samples was also determined. The genotoxicity of the extracts was determined by the SOSMA. Relative activity (RA) as determined by the SOSMA is a quantitative measure of genotoxicity based on a comparison to the activity of the mutagen, 4-nitroquinoline oxide. Low levels of RA (about 2x background) were detected in waters from sites within these states. There was considerable temporal and spatial variation in the observed RA, but no definite patterns were observed in the variation. Between sampling sites there was a positive correlation between RA and TOC; however, this relationship appeared to be reversed occasionally within a sampling site. The extraction and bioassay methods provide an easy and relatively inexpensive means of determining water quality.

Improved discovery of NEON data and samples though vocabularies, workflows, and web tools

NASA Astrophysics Data System (ADS)

Laney, C. M.; Elmendorf, S.; Flagg, C.; Harris, T.; Lunch, C. K.; Gulbransen, T.

2017-12-01

The National Ecological Observatory Network (NEON) is a continental-scale ecological observation facility sponsored by the National Science Foundation and operated by Battelle. NEON supports research on the impacts of invasive species, land use change, and environmental change on natural resources and ecosystems by gathering and disseminating a full suite of observational, instrumented, and airborne datasets from field sites across the U.S. NEON also collects thousands of samples from soil, water, and organisms every year, and partners with numerous institutions to analyze and archive samples. We have developed numerous new technologies to support processing and discovery of this highly diverse collection of data. These technologies include applications for data collection and sample management, processing pipelines specific to each collection system (field observations, installed sensors, and airborne instruments), and publication pipelines. NEON data and metadata are discoverable and downloadable via both a public API and data portal. We solicit continued engagement and advice from the informatics and environmental research communities, particularly in the areas of data versioning, usability, and visualization.

The low-temperature method for study of coniferous tissues in the environmental scanning electron microscope.

PubMed

Neděla, Vilém; Tihlaříková, Eva; Hřib, Jiří

2015-01-01

The use of non-standard low-temperature conditions in environmental scanning electron microscopy might be promising for the observation of coniferous tissues in their native state. This study is aimed to analyse and evaluate the method based on the principle of low-temperature sample stabilization. We demonstrate that the upper mucous layer is sublimed and a microstructure of the sample surface can be observed with higher resolution at lower gas pressure conditions, thanks to a low-temperature method. An influence of the low-temperature method on sample stability was also studied. The results indicate that high-moisture conditions are not suitable for this method and often cause the collapse of samples. The potential improvement of stability to beam damage has been demonstrated by long-time observation at different operation parameters. We finally show high applicability of the low-temperature method on different types of conifers and Oxalis acetosella. © 2014 Wiley Periodicals, Inc.

A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems

PubMed Central

Luo, Zhongqiang; Zhu, Lidong

2015-01-01

In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low. PMID:26287209

A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems.

PubMed

Luo, Zhongqiang; Zhu, Lidong

2015-08-14

In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low.

Overproduced esterases in Culex pipiens quinquefasciatus (Diptera: Culicidae) from Vietnam.

PubMed

Pasteur, N; Marquine, M; Hoang, T H; Nam, V S; Failloux, A B

2001-09-01

The electrophoretic polymorphism of loci encoding for 10 enzymes was studied in Culex p. quinquefasciatus Say from six localities of Vietnam. The analysis of 11 "neutral genes" showed that differentiation among samples was low, but significant (Fst = 0.06), and significantly related to geographic distance between sample sites. These results are similar to those observed in other countries (Europe and west Africa). A single type of overproduced esterases (A2-B2) was observed, and its frequency was high (60-100%) in all samples. This situation is in sharp contrast with that observed in other countries of South East Asia (China, South Korea and Japan), where two or more types of overproduced esterases have been reported. A map summarizing the geographic distribution of Asian Cr. p. quinquefasciatus with overproduced esterases is provided.

Development of Botanical Composition in Maribaya Pasture, Brebes, Central Java

NASA Astrophysics Data System (ADS)

Umami, N.; Ngadiyono, N.; Panjono; Agus, F. N.; Shirothul, H. M.; Budisatria, I. G. S.; Hendrawati, Y.; Subroto, I.

2018-02-01

The research was aimed to observe the development of botanical composition in Maribaya pastures. The sampling method was cluster random sampling. The observed variables were the type of forages and the botanical composition in the pasture. Botanical composition was measured by using Line Intercept method and the production was measured by the estimation of botany production for each square meter using its dry matter measurement. The botani sampling was performed using square with size of 1×1 m2. The observation was performed before the pasture made (at 2015) and after the pasture made (at 2017). Based on the research result, it was found that there was significant difference between the forage type in the pasture at 2015 and at 2017. It happens due to the adjustment for the Jabres cattle feed.

Observation of Live Ticks (Haemaphysalis flava) by Scanning Electron Microscopy under High Vacuum Pressure

PubMed Central

Ishigaki, Yasuhito; Nakamura, Yuka; Oikawa, Yosaburo; Yano, Yasuhiro; Kuwabata, Susumu; Nakagawa, Hideaki; Tomosugi, Naohisa; Takegami, Tsutomu

2012-01-01

Scanning electron microscopes (SEM), which image sample surfaces by scanning with an electron beam, are widely used for steric observations of resting samples in basic and applied biology. Various conventional methods exist for SEM sample preparation. However, conventional SEM is not a good tool to observe living organisms because of the associated exposure to high vacuum pressure and electron beam radiation. Here we attempted SEM observations of live ticks. During 1.5×10−3 Pa vacuum pressure and electron beam irradiation with accelerated voltages (2–5 kV), many ticks remained alive and moved their legs. After 30-min observation, we removed the ticks from the SEM stage; they could walk actively under atmospheric pressure. When we tested 20 ticks (8 female adults and 12 nymphs), they survived for two days after SEM observation. These results indicate the resistance of ticks against SEM observation. Our second survival test showed that the electron beam, not vacuum conditions, results in tick death. Moreover, we describe the reaction of their legs to electron beam exposure. These findings open the new possibility of SEM observation of living organisms and showed the resistance of living ticks to vacuum condition in SEM. These data also indicate, for the first time, the usefulness of tick as a model system for biology under extreme condition. PMID:22431980

Sporadic sampling, not climatic forcing, drives observed early hominin diversity.

PubMed

Maxwell, Simon J; Hopley, Philip J; Upchurch, Paul; Soligo, Christophe

2018-05-08

The role of climate change in the origin and diversification of early hominins is hotly debated. Most accounts of early hominin evolution link observed fluctuations in species diversity to directional shifts in climate or periods of intense climatic instability. None of these hypotheses, however, have tested whether observed diversity patterns are distorted by variation in the quality of the hominin fossil record. Here, we present a detailed examination of early hominin diversity dynamics, including both taxic and phylogenetically corrected diversity estimates. Unlike past studies, we compare these estimates to sampling metrics for rock availability (hominin-, primate-, and mammal-bearing formations) and collection effort, to assess the geological and anthropogenic controls on the sampling of the early hominin fossil record. Taxic diversity, primate-bearing formations, and collection effort show strong positive correlations, demonstrating that observed patterns of early hominin taxic diversity can be explained by temporal heterogeneity in fossil sampling rather than genuine evolutionary processes. Peak taxic diversity at 1.9 million years ago (Ma) is a sampling artifact, reflecting merely maximal rock availability and collection effort. In contrast, phylogenetic diversity estimates imply peak diversity at 2.4 Ma and show little relation to sampling metrics. We find that apparent relationships between early hominin diversity and indicators of climatic instability are, in fact, driven largely by variation in suitable rock exposure and collection effort. Our results suggest that significant improvements in the quality of the fossil record are required before the role of climate in hominin evolution can be reliably determined. Copyright © 2018 the Author(s). Published by PNAS.

Adaptive sampling in behavioral surveys.

PubMed

Thompson, S K

1997-01-01

Studies of populations such as drug users encounter difficulties because the members of the populations are rare, hidden, or hard to reach. Conventionally designed large-scale surveys detect relatively few members of the populations so that estimates of population characteristics have high uncertainty. Ethnographic studies, on the other hand, reach suitable numbers of individuals only through the use of link-tracing, chain referral, or snowball sampling procedures that often leave the investigators unable to make inferences from their sample to the hidden population as a whole. In adaptive sampling, the procedure for selecting people or other units to be in the sample depends on variables of interest observed during the survey, so the design adapts to the population as encountered. For example, when self-reported drug use is found among members of the sample, sampling effort may be increased in nearby areas. Types of adaptive sampling designs include ordinary sequential sampling, adaptive allocation in stratified sampling, adaptive cluster sampling, and optimal model-based designs. Graph sampling refers to situations with nodes (for example, people) connected by edges (such as social links or geographic proximity). An initial sample of nodes or edges is selected and edges are subsequently followed to bring other nodes into the sample. Graph sampling designs include network sampling, snowball sampling, link-tracing, chain referral, and adaptive cluster sampling. A graph sampling design is adaptive if the decision to include linked nodes depends on variables of interest observed on nodes already in the sample. Adjustment methods for nonsampling errors such as imperfect detection of drug users in the sample apply to adaptive as well as conventional designs.

40 CFR 61.54 - Sludge sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge shall...

40 CFR 61.54 - Sludge sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge shall...

Ultrafast scanning probe microscopy

DOEpatents

Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

1995-05-16

An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

Ultrafast scanning probe microscopy

DOEpatents

Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

1995-01-01

An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

Biocompatible, smooth, plasma-treated nickel-titanium surface--an adequate platform for cell growth.

PubMed

Chrzanowski, W; Szade, J; Hart, A D; Knowles, J C; Dalby, M J

2012-02-01

High nickel content is believed to reduce the number of biomedical applications of nickel-titanium alloy due to the reported toxicity of nickel. The reduction in nickel release and minimized exposure of the cell to nickel can optimize the biocompatibility of the alloy and increase its use in the application where its shape memory effects and pseudoelasticity are particularly useful, e.g., spinal implants. Many treatments have been tried to improve the biocompatibility of Ni-Ti, and results suggest that a native, smooth surface could provide sufficient tolerance, biologically. We hypothesized that the native surface of nickel-titanium supports cell differentiation and insures good biocompatibility. Three types of surface modifications were investigated: thermal oxidation, alkali treatment, and plasma sputtering, and compared with smooth, ground surface. Thermal oxidation caused a drop in surface nickel content, while negligible chemistry changes were observed for plasma-modified samples when compared with control ground samples. In contrast, alkali treatment caused significant increase in surface nickel concentration and accelerated nickel release. Nickel release was also accelerated in thermally oxidized samples at 600 °C, while in other samples it remained at low level. Both thermal oxidation and alkali treatment increased the roughness of the surface, but mean roughness R(a) was significantly greater for the alkali-treated ones. Ground and plasma-modified samples had 'smooth' surfaces with R(a)=4 nm. Deformability tests showed that the adhesion of the surface layers on samples oxidized at 600 °C and alkali treatment samples was not sufficient; the layer delaminated upon deformation. It was observed that the cell cytoskeletons on the samples with a high nickel content or release were less developed, suggesting some negative effects of nickel on cell growth. These effects were observed primarily during initial cell contact with the surface. The most favorable cell responses were observed for ground and plasma-sputtered surfaces. These studies indicated that smooth, plasma-modified surfaces provide sufficient properties for cells to grow. © The Author(s), 2011.

Spitzer Observations of GRB Hosts: A Legacy Approach

NASA Astrophysics Data System (ADS)

Perley, Daniel; Tanvir, Nial; Hjorth, Jens; Berger, Edo; Laskar, Tanmoy; Michalowski, Michal; Chary, Ranga-Ram; Fynbo, Johan; Levan, Andrew

2012-09-01

The host galaxies of long-duration GRBs are drawn from uniquely broad range of luminosities and redshifts. Thus they offer the possibility of studying the evolution of star-forming galaxies without the limitations of other luminosity-selected samples, which typically are increasingly biased towards the most massive systems at higher redshift. However, reaping the full benefits of this potential requires careful attention to the selection biases affecting host identification. To this end, we propose observations of a Legacy sample of 70 GRB host galaxies (an additional 70 have already been observed by Spitzer), in order to constrain the mass and luminosity function in GRB-selected galaxies at high redshift, including its dependence on redshift and on properties of the afterglow. Crucially, and unlike previous Spitzer surveys, this sample is carefully designed to be uniform and free of optical selection biases that have caused previous surveys to systematically under-represent the role of luminous, massive hosts. We also propose to extend to larger, more powerfully constraining samples the study of two science areas where Spitzer observations have recently shown spectacular success: the hosts of dust-obscured GRBs (which promise to further our understanding of the connection between GRBs and star-formation in the most luminous galaxies), and the evolution of the mass-metallicity relation at z>2 (for which GRB host observations provide particularly powerful constraints on high-z chemical evolution).

The Challenge of Identifying Controls on Cloud Properties and Precipitation Onset for Cumulus Congestus Sampled During MC3E

DOE PAGES

Mechem, David B.; Giangrande, Scott E.

2018-03-01

Here, the controls on precipitation onset and the transition from shallow cumulus to congestus are explored using a suite of 16 large–eddy simulations based on the 25 May 2011 event from the Midlatitude Continental Convective Clouds Experiment (MC3E). The thermodynamic variables in the model are relaxed at various timescales to observationally constrained temperature and moisture profiles in order to better reproduce the observed behavior of precipitation onset and total precipitation. Three of the simulations stand out as best matching the precipitation observations and also perform well for independent comparisons of cloud fraction, precipitation area fraction, and evolution of cloud topmore » occurrence. All three simulations exhibit a destabilization over time, which leads to a transition to deeper clouds, but the evolution of traditional stability metrics by themselves is not able to explain differences in the simulations. Conditionally sampled cloud properties (in particular, mean cloud buoyancy), however, do elicit differences among the simulations. The inability of environmental profiles alone to discern subtle differences among the simulations and the usefulness of conditionally sampled model quantities argue for hybrid observational/modeling approaches. These combined approaches enable a more complete physical understanding of cloud systems by combining observational sampling of time–varying three–dimensional meteorological quantities and cloud properties, along with detailed representation of cloud microphysical and dynamical processes from numerical models.« less

The Challenge of Identifying Controls on Cloud Properties and Precipitation Onset for Cumulus Congestus Sampled During MC3E

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

Mechem, David B.; Giangrande, Scott E.

Here, the controls on precipitation onset and the transition from shallow cumulus to congestus are explored using a suite of 16 large–eddy simulations based on the 25 May 2011 event from the Midlatitude Continental Convective Clouds Experiment (MC3E). The thermodynamic variables in the model are relaxed at various timescales to observationally constrained temperature and moisture profiles in order to better reproduce the observed behavior of precipitation onset and total precipitation. Three of the simulations stand out as best matching the precipitation observations and also perform well for independent comparisons of cloud fraction, precipitation area fraction, and evolution of cloud topmore » occurrence. All three simulations exhibit a destabilization over time, which leads to a transition to deeper clouds, but the evolution of traditional stability metrics by themselves is not able to explain differences in the simulations. Conditionally sampled cloud properties (in particular, mean cloud buoyancy), however, do elicit differences among the simulations. The inability of environmental profiles alone to discern subtle differences among the simulations and the usefulness of conditionally sampled model quantities argue for hybrid observational/modeling approaches. These combined approaches enable a more complete physical understanding of cloud systems by combining observational sampling of time–varying three–dimensional meteorological quantities and cloud properties, along with detailed representation of cloud microphysical and dynamical processes from numerical models.« less

The Challenge of Identifying Controls on Cloud Properties and Precipitation Onset for Cumulus Congestus Sampled During MC3E

NASA Astrophysics Data System (ADS)

Mechem, David B.; Giangrande, Scott E.

2018-03-01

Controls on precipitation onset and the transition from shallow cumulus to congestus are explored using a suite of 16 large-eddy simulations based on the 25 May 2011 event from the Midlatitude Continental Convective Clouds Experiment (MC3E). The thermodynamic variables in the model are relaxed at various timescales to observationally constrained temperature and moisture profiles in order to better reproduce the observed behavior of precipitation onset and total precipitation. Three of the simulations stand out as best matching the precipitation observations and also perform well for independent comparisons of cloud fraction, precipitation area fraction, and evolution of cloud top occurrence. All three simulations exhibit a destabilization over time, which leads to a transition to deeper clouds, but the evolution of traditional stability metrics by themselves is not able to explain differences in the simulations. Conditionally sampled cloud properties (in particular, mean cloud buoyancy), however, do elicit differences among the simulations. The inability of environmental profiles alone to discern subtle differences among the simulations and the usefulness of conditionally sampled model quantities argue for hybrid observational/modeling approaches. These combined approaches enable a more complete physical understanding of cloud systems by combining observational sampling of time-varying three-dimensional meteorological quantities and cloud properties, along with detailed representation of cloud microphysical and dynamical processes from numerical models.

VLA observations of radio sources in interacting galaxy pairs in poor clusters

NASA Technical Reports Server (NTRS)

Batuski, David J.; Hanisch, Robert J.; Burns, Jack O.

1992-01-01

Observations of 16 radio sources in interacting galaxies in 14 poor clusters were made using the Very Large Array in the B configuration at lambda of 6 and 2 cm. These sources had been unresolved in earlier observations at lambda of 21 cm, and were chosen as a sample to determine which of three models for radio source formation actually pertains in interacting galaxies. From the analysis of this sample, the starburst model appears most successful, but the 'central monster' model could pertain in some cases.

Assessment of arsenic surface contamination in a museum anthropology department.

PubMed

Gribovich, Andrey; Lacey, Steven; Franke, John; Hinkamp, David

2013-02-01

To assess potential arsenic (As) contamination of work surfaces to improve upon the control strategy at an anthropology department in a large natural history museum. Work practices were observed and control strategy reviewed to inform an occupational hygiene assessment strategy utilizing surface wipe sampling. A total of 35 sampling targets were identified, focusing on surfaces that receive high touch traffic, including workstations, artifact transport carts, and elevator buttons. Arsenic sampling and analysis were performed using reference method Occupational Safety and Health Administration ID-125G. Four of the sampling areas returned detectable levels of As, ranging from 0.052 to 0.350 μg/100 cm. Workplace observations and wipe sampling data enabled the development of recommendations to help to further reduce potential occupational exposure to As. Continuous reduction of surface contamination is prudent for known human carcinogens.

Synthesis and characterization of 64SiO2-26CaO-5P2O5-5CuO bioactive composition for the growth of hydroxyapatite layer by XRD, Raman and pH studies

NASA Astrophysics Data System (ADS)

Kaur, Pardeep; Singh, K. J.

2016-05-01

Bioactive sample with the nominal composition of 64SiO2-26CaO-5P2O5-5CuO has been prepared in the laboratory by using the sol-gel technique. The bioactivity of the prepared sample has been analyzed by using the Tris Simulated Body Fluid which has also been prepared in the laboratory. XRD and Raman techniques have been employedto probe the formation of hydroxyapatite layer. pH studies has also been undertaken to check the acidic/non-acidic behavior of sample. Growth of hydroxyapatite layer has been observed after one day on the surface of the sample. Moreover, sample has been observed to be non-acidic in nature.

Preparation and Loading Process of Single Crystalline Samples into a Gas Environmental Cell Holder for In Situ Atomic Resolution Scanning Transmission Electron Microscopic Observation.

PubMed

Straubinger, Rainer; Beyer, Andreas; Volz, Kerstin

2016-06-01

A reproducible way to transfer a single crystalline sample into a gas environmental cell holder for in situ transmission electron microscopic (TEM) analysis is shown in this study. As in situ holders have only single-tilt capability, it is necessary to prepare the sample precisely along a specific zone axis. This can be achieved by a very accurate focused ion beam lift-out preparation. We show a step-by-step procedure to prepare the sample and transfer it into the gas environmental cell. The sample material is a GaP/Ga(NAsP)/GaP multi-quantum well structure on Si. Scanning TEM observations prove that it is possible to achieve atomic resolution at very high temperatures in a nitrogen environment of 100,000 Pa.

ATCA observations of the MACS-Planck Radio Halo Cluster Project. II. Radio observations of an intermediate redshift cluster sample

NASA Astrophysics Data System (ADS)

Martinez Aviles, G.; Johnston-Hollitt, M.; Ferrari, C.; Venturi, T.; Democles, J.; Dallacasa, D.; Cassano, R.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Arnaud, M.; Aghanim, N.; Brown, S.; Douspis, M.; Hurier, J.; Intema, H. T.; Langer, M.; Macario, G.; Pointecouteau, E.

2018-04-01

Aim. A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the largely unexplored intermediate redshift range (0.3 < z < 0.44). Methods: In search of diffuse emission, deep radio imaging of the clusters are presented from wide band (1.1-3.1 GHz), full resolution ( 5 arcsec) observations with the Australia Telescope Compact Array (ATCA). The visibilities were also imaged at lower resolution after point source modelling and subtraction and after a taper was applied to achieve better sensitivity to low surface brightness diffuse radio emission. In case of non-detection of diffuse sources, we set upper limits for the radio power of injected diffuse radio sources in the field of our observations. Furthermore, we discuss the dynamical state of the observed clusters based on an X-ray morphological analysis with XMM-Newton. Results: We detect a giant radio halo in PSZ2 G284.97-23.69 (z = 0.39) and a possible diffuse source in the nearly relaxed cluster PSZ2 G262.73-40.92 (z = 0.421). Our sample contains three highly disturbed massive clusters without clear traces of diffuse emission at the observed frequencies. We were able to inject modelled radio haloes with low values of total flux density to set upper detection limits; however, with our high-frequency observations we cannot exclude the presence of RH in these systems because of the sensitivity of our observations in combination with the high z of the observed clusters. The reduced images are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A94

Polarimetry of optically selected BL Lacertae candidates from the SDSS

NASA Astrophysics Data System (ADS)

Heidt, J.; Nilsson, K.

2011-05-01

We present and discuss polarimetric observations of 182 targets drawn from an optically selected sample of 240 probable BL Lac candidates out of the SDSS compiled by Collinge et al. (2005, AJ, 129, 2542). In contrast to most other BL Lac candidate samples extracted from the SDSS, its radio- and/or X-ray properties have not been taken into account for its derivation. Thus, because its selection is based on optical properties alone, it may be less prone to selection effects inherent in other samples derived at different frequencies, so it offers a unique opportunity to extract the first unbiased BL Lac luminosity function that is suitably large in size. We found 124 out of 182 targets (68%) to be polarized, 95 of the polarized targets (77%) to be highly polarized (>4%). The low-frequency peaked BL Lac candidates in the sample are on average only slightly more polarized than the high-frequency peaked ones. Compared to earlier studies, we found a high duty cycle in high polarization (˜ 66+2-14% to be >4% polarized) in high-frequency peaked BL Lac candidates. This may come from our polarization analysis, which minimizes the contamination by host galaxy light. No evidence of radio-quiet BL Lac objects in the sample was found. Our observations show that the probable sample of BL Lac candidates of Collinge et al. (2005) indeed contains a large number of bona fide BL Lac objects. High S/N spectroscopy and deep X-ray observations are required to construct the first luminosity function of optically selected BL Lac objects and to test more stringently for any radio-quiet BL Lac objects in the sample. Based on observations collected with the NTT on La Silla (Chile) operated by the European Southern Observatory in the course of the observing proposal 082.B-0133.Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA), operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofisica de Andalucia (CSIC).Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/529/A162

Peste des petits ruminants infection in domestic ruminants in Sudan.

PubMed

Intisar, K S; Ali, Y H; Haj, M A; Sahar, M A T; Shaza, M M; Baraa, A M; Ishag, O M; Nouri, Y M; Taha, K M; Nada, E M; Ahmed, A M; Khalafalla, A I; Libeau, G; Diallo, A

2017-04-01

The existence of peste des petits ruminants (PPR) in domestic ruminants and camels in Sudan during 2008-2012 was investigated. Lung tissues and serum samples were randomly collected from sheep, goats, cattle, and camels at different areas of Sudan. A total of 12,384 serum samples were collected from clinically healthy 7413 sheep, 1988 camels, 1501 cattle, 1459 goats, and 23 gazelles at different areas in the Sudan. They were examined for PPR antibodies using competitive ELISA (cELISA). The overall detected seroprevalence of PPR in tested sera was 49.4%; seroprevalence values within species were 67.1, 48.2, 25.8, 2.1, and 21.7% in sheep, goat, cattle, camels, and gazelles, respectively. The highest seroprevalence (68.1%) was observed in sera collected from Darfur states, then the central states (54.3%). A total of 1276 lung tissue samples (623 sheep, 324 cattle, 220 camels, and 109 goats) were collected. The majority of lung samples were collected from clinically healthy animals that showed lesions on PM in slaughterhouses (95%) and during PPR outbreaks; samples were tested for PPR antigen using immunocapture ELISA (IcELISA). PPR antigen was detected in 233 out of the 1276 tested samples (18.3%). Positive results were observed in samples collected from clinically healthy and diseased animals. The observed prevalence values in each species were 33.6, 21.1, 15.4, and 12.3% in camel, goat, sheep, and cattle, respectively. PPR antigen was detected in samples from different areas; however, the highest prevalence (63.9%) was found in samples collected from the eastern states, then Khartoum state (28%). Trials for virus isolation were done in different cell cultures. Out of 30 IcELISA-positive samples inoculated in primary bovine and ovine kidney cells, Vero cells, the PPR virus was successfully isolated from 15 (eight sheep, five camels, and two goats) samples in the three cell culture types. Using RT-PCR, PPRV nucleic acid was detected in all 25 IcELISA-positive tested samples.

Single-particle investigation of summertime and wintertime Antarctic sea spray aerosols using low-Z particle EPMA, Raman microspectrometry, and ATR-FTIR imaging techniques

NASA Astrophysics Data System (ADS)

Eom, Hyo-Jin; Gupta, Dhrubajyoti; Cho, Hye-Rin; Hwang, Hee Jin; Do Hur, Soon; Gim, Yeontae; Ro, Chul-Un

2016-11-01

Two aerosol samples collected at King Sejong Korean scientific research station, Antarctica, on 9 December 2011 in the austral summer (sample S1) and 23 July 2012 in the austral winter (sample S2), when the oceanic chlorophyll a levels on the collection days of the samples were quite different, by ˜ 19 times (2.46 vs. 0.13 µg L-1, respectively), were investigated on a single-particle basis using quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), called low-Z particle EPMA, Raman microspectrometry (RMS), and attenuated total reflection Fourier transform infrared (ATR-FTIR) imaging techniques to obtain their characteristics based on the elemental chemical compositions, molecular species, and mixing state. X-ray analysis showed that the supermicron summertime and wintertime Antarctic aerosol samples have different elemental chemical compositions, even though all the individual particles analyzed were sea spray aerosols (SSAs); i.e., the contents of C, O, Ca, S, and Si were more elevated, whereas Cl was more depleted, for sample S1 than for sample S2. Based on qualitative analysis of the chemical species present in individual SSAs by the combined application of RMS and ATR-FTIR imaging, different organic species were observed in samples S1 and S2; i.e., Mg hydrate salts of alanine were predominant in samples S1 and S2, whereas Mg salts of fatty acids internally mixed with Mg hydrate salts of alanine were significant in sample S2. Although CaSO4 was observed significantly in both samples S1 and S2, other inorganic species, such as Na2SO4, NaNO3, Mg(NO3)2, SiO2, and CH3SO3Mg, were observed more significantly in sample S1, suggesting that those compounds may be related to the higher phytoplankton activity in summer.

Inter-observer variance with the diagnosis of myelodysplastic syndromes (MDS) following the 2008 WHO classification.

PubMed

Font, P; Loscertales, J; Benavente, C; Bermejo, A; Callejas, M; Garcia-Alonso, L; Garcia-Marcilla, A; Gil, S; Lopez-Rubio, M; Martin, E; Muñoz, C; Ricard, P; Soto, C; Balsalobre, P; Villegas, A

2013-01-01

Morphology is the basis of the diagnosis of myelodysplastic syndromes (MDS). The WHO classification offers prognostic information and helps with the treatment decisions. However, morphological changes are subject to potential inter-observer variance. The aim of our study was to explore the reliability of the 2008 WHO classification of MDS, reviewing 100 samples previously diagnosed with MDS using the 2001 WHO criteria. Specimens were collected from 10 hospitals and were evaluated by 10 morphologists, working in five pairs. Each observer evaluated 20 samples, and each sample was analyzed independently by two morphologists. The second observer was blinded to the clinical and laboratory data, except for the peripheral blood (PB) counts. Nineteen cases were considered as unclassified MDS (MDS-U) by the 2001 WHO classification, but only three remained as MDS-U by the 2008 WHO proposal. Discordance was observed in 26 of the 95 samples considered suitable (27 %). Although there were a high number of observers taking part, the rate of discordance was quite similar among the five pairs. The inter-observer concordance was very good regarding refractory anemia with excess blasts type 1 (RAEB-1) (10 of 12 cases, 84 %), RAEB-2 (nine of 10 cases, 90 %), and also good regarding refractory cytopenia with multilineage dysplasia (37 of 50 cases, 74 %). However, the categories with unilineage dysplasia were not reproducible in most of the cases. The rate of concordance with refractory cytopenia with unilineage dysplasia was 40 % (two of five cases) and 25 % with RA with ring sideroblasts (two of eight). Our results show that the 2008 WHO classification gives a more accurate stratification of MDS but also illustrates the difficulty in diagnosing MDS with unilineage dysplasia.

Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

PubMed

Register, Janna; Scaffidi, Jonathan; Angel, S Michael

2012-08-01

Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

Recombinant Reflectin-Based Optical Materials

DTIC Science & Technology

2012-01-01

sili- con substrates were placed in a sealed plastic box. The RH was controlled using a Dydra electronic cigar humidifier and monitored using a Fisher...diffraction gratings to generate diffraction patterns. Nano-spheres and la- mellar microstructures of refCBA samples were observed by scanning electron ...samples were observed by scanning electron microscopy and atomic force microscopy. Despite the reduced complexity of the refCBA protein compared to natural

Variation in the Helical Structure of Native Collagen

DTIC Science & Technology

2014-02-24

unsampled molecular transform of the sample (non-crystalline diffraction arising from the helical symmetry), these patterns also contain Bragg peaks...tissues may be treated as analogous to that from a single macromolecular crystal. Except that it arises from many fibrils within the sample , giving rise...density maps, constructed from experimentally determined phases and observed amplitudes, showed good agreement. The observed diffraction and the simulated

Sample processing approach for detection of ricin in surface samples.

PubMed

Kane, Staci; Shah, Sanjiv; Erler, Anne Marie; Alfaro, Teneile

2017-12-01

With several ricin contamination incidents reported over the past decade, rapid and accurate methods are needed for environmental sample analysis, especially after decontamination. A sample processing method was developed for common surface sampling devices to improve the limit of detection and avoid false negative/positive results for ricin analysis. Potential assay interferents from the sample matrix (bleach residue, sample material, wetting buffer), including reference dust, were tested using a Time-Resolved Fluorescence (TRF) immunoassay. Test results suggested that the sample matrix did not cause the elevated background fluorescence sometimes observed when analyzing post-bleach decontamination samples from ricin incidents. Furthermore, sample particulates (80mg/mL Arizona Test Dust) did not enhance background fluorescence or interfere with ricin detection by TRF. These results suggested that high background fluorescence in this immunoassay could be due to labeled antibody quality and/or quantity issues. Centrifugal ultrafiltration devices were evaluated for ricin concentration as a part of sample processing. Up to 30-fold concentration of ricin was observed by the devices, which serve to remove soluble interferents and could function as the front-end sample processing step to other ricin analytical methods. The procedure has the potential to be used with a broader range of environmental sample types and with other potential interferences and to be followed by other ricin analytical methods, although additional verification studies would be required. Published by Elsevier B.V.

Ultrasonic Seismic Wave Elastic Moduli and Attenuation, Petro physical Models and Work Flows for Better Subsurface Imaging Related to Monitoring of Sequestrated Supercritical CO2 and Geothermal Energy Exploration

NASA Astrophysics Data System (ADS)

Harbert, W.; Delaney, D.; Mur, A. J.; Purcell, C.; Zorn, E.; Soong, Y.; Crandall, D.; Haljasmaa, I.

2016-12-01

To better understand the petrophysical response at ultrasonic frequencies in rhyolite and carbonate (relevant to CO2 storage and CO2 enhanced oil recovery) lithologies we conducted core analysis incorporating variation in temperature, effective pressure and pore filling fluid. Ultrasonic compressive and shear wave (VP, VS1 and VS2) velocities were measured allowing calculation of the Bulk modulus (K), Young's modulus (E), Lamè's first parameter (λ), Shear modulus (G), Poisson's ratio (ν), and P-wave modulus (M). In addition, from the ultrasonic waveform data collected, we employed the spectral ratio method to estimate the quality factor. Carbonate samples were tested dry, using atmospheric gas as the pore phase, and with deionized water, oil, and supercritical CO2. We observed that Qp was directly proportional to effective pressure in our rhyolite samples. In addition, we observed effects of core anisotropy on Qp, however this was not apparent in higher porosity samples. Increasing effective pressure seems to decrease the effects of ultrasonic P-wave anisotropy. Qp was inversely proportional to temperature, however this was not observed for higher porosity samples. Qp was highly dependent on the rock porosity. Higher porosity samples displayed significantly lower values of Qp. In our experiments we observed that ultrasonic wave scattering due to heterogeneities in the carbonate samples was dominant. Although we observed lower μρ values, trends in our data strongly agreed with the model proposed workers interpreting AVO trends in a LMR cross plot space. We found that μρ was proportional to temperature while λρ was temperature independent and that λρ-μρ trends were extremely dependent on porosity. Higher porosity results in lower values for both λρ and μρ. The presence of fluids causes a distinct shift in λρ values, an observation which could provide insight into subsurface exploration using amplitude variation with offset (AVO) classification. We present approaches to incorporate these laboratory results into well log calibrated MATLAB based Gassmann-Biot fluid substitution models incorporating compliant porosity, Thomsen parameters models that utilize orthorhombic velocity anisotropy to predict seismic responses.

Variations in Canonical Star-Forming Laws at Low Metallicity

NASA Astrophysics Data System (ADS)

Monkiewicz, Jacqueline; Bowman, Judd D.; Scowen, Paul

2018-01-01

Empirically-determined star formation relations link observed galaxy luminosities to extrapolated star formation rates at almost every observable wavelength range. These laws are a cornerstone of extragalactic astronomy, and will be critically important for interpreting upcoming observations of early high-redshift protogalaxies with JWST and WFIRST. There are indications at a variety of wavelengths that these canonical relations may become unreliable at the lowest metallicities observed. This potentially complicates interpretation of the earliest protogalaxies, which are expected to be pristine and largely unenriched by stellar nucleosynthesis. Using a sample of 15 local dwarf galaxies with 12+[O/H] < 8.2, I focus on two of these relations: the far-infrared/radio relation and the H-alpha/ultraviolet relation. The sample is chosen to have pre-existing far-IR and UV observations, and to span the full spread of the galaxy mass-metallicity relationship at low luminosity, so that luminosity and metallicity may be examined separately. Radio continuum observations of low metallicity dwarf galaxies 1 Zw 18 and SBS 0335-052E suggest that the far-IR/radio relation probably deviates at low metallicities, but the low luminosity end of the relation is not well sampled. The upgraded Jansky Very Large Array has the sensitivity to fill in this gap. I have obtained 45 hours of L- and C-band continuum data of my dwarf galaxy sample. I present radio continuum imaging of an initial sub-sample of Local Group dwarfs, some of which have never before been detected in radio continuum. The H-alpha/UV relationship is likewise known to become unreliable for dwarf galaxies, though this has been attributed to dwarf galaxy "bursty-ness" rather than metallicity effects. I have conducted a parallel survey of emission line imaging to study the underlying astrophysics of the H-alpha/UV relation. Using Balmer decrement imaging, I map out the pixel-to-pixel dust distribution and geometry within the nearest galaxies in my sample. I compare this to GALEX UV imaging. I discuss implications for UV escape fraction, and present initial results of the canonical star-forming relations at low galaxy luminosity and metallicity. THIS IS A POSTER AND WILL BE LOCATED IN THE AAS BOOTH.

Performing Mineral Hydration Experiments in the CheMin Diffractometer on Mars

NASA Technical Reports Server (NTRS)

Vaniman, D. T.; Yen, A. S.; Rampe, E. B.; Blake, D. F.; Chipera, S. J.; Morookian, J. M.; Ming, D. W.; Bristow, T. F.; Morris, R. V.; Geller, R.;

VizieR Online Data Catalog: X-ray observations of HCG galaxies (Tzanavaris+, 2016)

NASA Astrophysics Data System (ADS)

Tzanavaris, P.; Hornschemeier, A. E.; Gallagher, S. C.; Lenkic, L.; Desjardins, T. D.; Walker, L. M.; Johnson, K. E.; Mulchaey, J. S.

2016-04-01

In this paper we study a sample of 15 compact groups (CGs) observed with Chandra/ACIS, Swift/UVOT and Spitzer/IRAC-MIPS for which archival data exist, allowing us to obtain SFRs, stellar masses, sSFRs and X-ray fluxes and luminosities. Table 1 shows the group sample, including redshifts, luminosity distances and group evolutionary types. Allowing for the fact that some galaxies do not fall in the field of view of all three instruments, the total number of CG galaxies analyzed is 47. Details on the Swift and Spitzer observations and data for systems in this sample can be found in Tzanavaris et al. (2010ApJ...716..556T) and (L. Lenkic et al. 2015, in preparation). For Chandra/ACIS observations we refer the reader to Tzanavaris et al. (2014, J/ApJS/212/9) and Desjardins et al. (2013ApJ...763..121D; 2014ApJ...790..132D). (2 data files).

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

Pern, F.J.; Glick, S.H.

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVE layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregularmore » changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants. {copyright} {ital 1999 American Institute of Physics.}« less

Comparative statistical analysis of carcinogenic and non-carcinogenic effects of uranium in groundwater samples from different regions of Punjab, India.

PubMed

Saini, Komal; Singh, Parminder; Bajwa, Bikramjit Singh

2016-12-01

LED flourimeter has been used for microanalysis of uranium concentration in groundwater samples collected from six districts of South West (SW), West (W) and North East (NE) Punjab, India. Average value of uranium content in water samples of SW Punjab is observed to be higher than WHO, USEPA recommended safe limit of 30µgl -1 as well as AERB proposed limit of 60µgl -1 . Whereas, for W and NE region of Punjab, average level of uranium concentration was within AERB recommended limit of 60µgl -1 . Average value observed in SW Punjab is around 3-4 times the value observed in W Punjab, whereas its value is more than 17 times the average value observed in NE region of Punjab. Statistical analysis of carcinogenic as well as non carcinogenic risks due to uranium have been evaluated for each studied district. Copyright © 2016 Elsevier Ltd. All rights reserved.

Airborne Observation of the Hayabusa Sample Return Capsule Re-Entry

NASA Technical Reports Server (NTRS)

Grinstead, Jay H.; Jenniskens, Peter; Cassell, Alan M.; Albers, James; Winter, Michael W.

2011-01-01

NASA Ames Research Center and the SETI Institute collaborated on an effort to observe the Earth re-entry of the Japan Aerospace Exploration Agency's Hayabusa sample return capsule. Hayabusa was an asteroid exploration mission that retrieved a sample from the near-Earth asteroid Itokawa. Its sample return capsule re-entered over the Woomera Prohibited Area in southern Australia on June 13, 2010. Being only the third sample return mission following NASA's Genesis and Stardust missions, Hayabusa's return was a rare opportunity to collect aerothermal data from an atmospheric entry capsule returning at superorbital speeds. NASA deployed its DC-8 airborne laboratory and a team of international researchers to Australia for the re-entry. For approximately 70 seconds, spectroscopic and radiometric imaging instruments acquired images and spectra of the capsule, its wake, and destructive re-entry of the spacecraft bus. Once calibrated, spectra of the capsule will be interpreted to yield data for comparison with and validation of high fidelity and engineering simulation tools used for design and development of future atmospheric entry system technologies. A brief summary of the Hayabusa mission, the preflight preparations and observation mission planning, mission execution, and preliminary spectral data are documented.

A survey of air quality in Singapore

NASA Astrophysics Data System (ADS)

Lai, Y. K.; Tang, S. M.

1993-04-01

Ambient aerosol samples were collected near an industrial area in Singapore during the period of July 91 to January 92. The sampling site was a highway at a height of about 20 m. PIXE analysis of these samples was carried out using 1.8 MeV protons. Thirteen trace elements were observed, ranging from Si to Pb. Among these, Cl and S had the highest concentrations. The former was attributed to the sea-salt particles and the latter could be due to the presence of oil refineries in the vicinity. Pb was found to be below the detection limit of 30 ngm -3 in most of the samples analysed. This is likely due to the fact that unleaded petrol was used by many cars in Singapore and that the sampling point was quite a distance away from the ground level. The observed variations in concentration for most of the trace elements were well-correlated with traffic intensity and meteorological conditions. Time variation patterns on weekdays and during weekends were also observed. A higher level of pollutants was detected during the period when there were prolonged forest fires in the nearby islands in Indonesia.

The effect of precursor types on the magnetic properties of Y-type hexa-ferrite composite

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

Kim, Chin Mo; Na, Eunhye; Kim, Ingyu

2015-05-07

With magnetic composite including uniform magnetic particles, we expect to realize good high-frequency soft magnetic properties. We produced needle-like (α-FeOOH) nanoparticles with nearly uniform diameter and length of 20 and 500 nm. Zn-doped Y-type hexa-ferrite samples were prepared by solid state reaction method using the uniform goethite and non-uniform hematite (Fe{sub 2}O{sub 3}) with size of <1 μm, respectively. The micrographs observed by scanning electron microscopy show that more uniform hexagonal plates are observed in ZYG-sample (Zn-doped Y-type hexa-ferrite prepared with non-uniform hematite) than in ZYH-sample (Zn-doped Y-type hexa-ferrite prepared with uniform goethite). The permeability (μ′) and loss tangent (δ) atmore » 2 GHz are 2.31 and 0.07 in ZYG-sample and 2.0 and 0.07 in ZYH sample, respectively. We can observe that permeability and loss tangent are strongly related to the particle size and uniformity based on the nucleation, growth, and two magnetizing mechanisms: spin rotation and domain wall motion. The complex permeability spectra also can be numerically separated into spin rotational and domain wall resonance components.« less

SAMOS Surface Fluxes

NASA Astrophysics Data System (ADS)

Smith, Shawn; Bourassa, Mark

2014-05-01

The development of a new surface flux dataset based on underway meteorological observations from research vessels will be presented. The research vessel data center at the Florida State University routinely acquires, quality controls, and distributes underway surface meteorological and oceanographic observations from over 30 oceanographic vessels. These activities are coordinated by the Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative in partnership with the Rolling Deck to Repository (R2R) project. Recently, the SAMOS data center has used these underway observations to produce bulk flux estimates for each vessel along individual cruise tracks. A description of this new flux product, along with the underlying data quality control procedures applied to SAMOS observations, will be provided. Research vessels provide underway observations at high-temporal frequency (1 min. sampling interval) that include navigational (position, course, heading, and speed), meteorological (air temperature, humidity, wind, surface pressure, radiation, rainfall), and oceanographic (surface sea temperature and salinity) samples. Vessels recruited to the SAMOS initiative collect a high concentration of data within the U.S. continental shelf and also frequently operate well outside routine shipping lanes, capturing observations in extreme ocean environments (Southern, Arctic, South Atlantic, and South Pacific oceans). These observations are atypical for their spatial and temporal sampling, making them very useful for many applications including validation of numerical models and satellite retrievals, as well as local assessments of natural variability. Individual SAMOS observations undergo routine automated quality control and select vessels receive detailed visual data quality inspection. The result is a quality-flagged data set that is ideal for calculating turbulent flux estimates. We will describe the bulk flux algorithms that have been applied to the observations and the choices of constants that are used. Analysis of the preliminary SAMOS flux products will be presented, including spatial and temporal coverage for each derived parameter. The unique quality and sampling locations of research vessel observations and their independence from many models and products makes them ideal for validation studies. The strengths and limitations of research observations for flux validation studies will be discussed. The authors welcome a discussion with the flux community regarding expansion of the SAMOS program to include additional international vessels, thus facilitating and expansion of this research vessel-based flux product.

Shear weakening for different lithologies observed at different saturation stages

NASA Astrophysics Data System (ADS)

Diethart-Jauk, Elisabeth; Gegenhuber, Nina

2018-01-01

For this study, samples from different lithologies ("Leitha"-limestone, "Dachstein"-limestone, "Haupt"-dolomite, "Bunt"-sandstone, Grey Berea sandstone, granite, quartzite and basalt) were selected. Samples were dried at 70 °C, respectively 105 °C and were saturated with brine. Mass, porosity, permeability, compressional and shear wave velocity were determined from dry and brine saturated samples at laboratory conditions, based on an individual measurement program. Shear modulus was calculated to find out, if shear weakening exists for the dataset. Shear weakening means that shear modulus of dry samples is higher than of saturated samples, but it is assumed that shear modulus is unaffected by saturation. "Dachstein"-limestone and basalt show shear weakening, quartzite samples show both weakening and hardening. Granite samples are affected by temperature, after drying with 105 °C no change can be observed anymore. "Bunt"-sandstone samples show a change in the shear modulus in a small extent, although they may contain clay minerals. The other lithologies show no effect. Explanations for carbonate samples can be the complicated pore structure, for basalt it could be that weathering creates clay minerals which are known as causes for a change of the shear modulus. Fluid viscosity can also be an important factor.

(I Can’t Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research

PubMed Central

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: “random chance,” which is based on probability sampling, “minimal information,” which yields at least one new code per sampling step, and “maximum information,” which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario. PMID:28746358

Establishing the feasibility of direct observation in the assessment of tics in children with chronic tic disorders.

PubMed

Himle, Michael B; Chang, Susanna; Woods, Douglas W; Pearlman, Amanda; Buzzella, Brian; Bunaciu, Liviu; Piacentini, John C

2006-01-01

Behavior analysis has been at the forefront in establishing effective treatments for children and adults with chronic tic disorders. As is customary in behavior analysis, the efficacy of these treatments has been established using direct-observation assessment methods. Although behavior-analytic treatments have enjoyed acceptance and integration into mainstream health care practices for tic disorders (e.g., psychiatry and neurology), the use of direct observation as a primary assessment tool has been neglected in favor of less objective methods. Hesitation to use direct observation appears to stem largely from concerns about the generalizability of clinic observations to other settings (e.g., home) and a lack of consensus regarding the most appropriate and feasible techniques for conducting and scoring direct observation. The purpose of the current study was to evaluate and establish a reliable, valid, and feasible direct-observation protocol capable of being transported to research and clinical settings. A total of 43 children with tic disorders, collected from two outpatient specialty clinics, were assessed using direct (videotape samples) and indirect (Yale Global Tic Severity Scale; YGTSS) methods. Videotaped observation samples were collected across 3 consecutive weeks and two different settings (clinic and home), were scored using both exact frequency counts and partial-interval coding, and were compared to data from a common indirect measure of tic severity (the YGTSS). In addition, various lengths of videotaped segments were scored to determine the optimal observation length. Results show that (a) clinic-based observations correspond well to home-based observations, (b) brief direct-observation segments scored with time-sampling methods reliably quantified tics, and (c) indirect methods did not consistently correspond with the direct methods.

Intra- and inter-observer agreement when using a descriptive classification scale for clinical assessment of faecal consistency in growing pigs.

PubMed

Pedersen, Ken Steen; Toft, Nils

2011-03-01

The objective of the current study was to evaluate intra- and inter-observer agreement using a descriptive classification scale with four categories, descriptive text and pictures for assessment of consistency in faecal samples from pigs post weaning. The four consistency categories were score one=firm and shaped, score two=soft and shaped, score three=loose and score four=watery. Five observers from the same veterinary practice examined 100 faecal samples using the scale with four categories. Four of the observers examined the 100 faecal samples twice within the same day. Within observers the difference in proportions for the individual consistency categories between two examinations was on average 0.04 (range: 0-0.10). The mean intra-observer agreement was 0.82 (range: 0.72-0.91) with a mean kappa value of 0.76 (range: 0.61-0.88). For inter-observer agreement overall kappa was 0.64. For the 10 pair-wise comparisons the mean inter-observer agreement was 0.73 (range: 0.61-0.90) with a mean kappa value of 0.64 (range: 0.48-0.87). The difference in proportions for the individual consistency categories was on average 0.08 (range: 0-0.17). In conclusion, the agreement observed for the descriptive classification scale with four categories, descriptive text and pictures may be categorized as a substantial to almost perfect intra-observer agreement and a moderate to almost perfect inter-observer agreement. However, more objective measures than clinical scales may still be needed to improve intra- and inter-observer agreement in research studies. Copyright © 2010 Elsevier B.V. All rights reserved.

VizieR Online Data Catalog: Tully-Fisher relation for SDSS galaxies (Reyes+, 2011)

NASA Astrophysics Data System (ADS)

Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Pizagno, J.; Lackner, C. N.

2012-05-01

In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity Vrot or Tully-Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of Vrot applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z<0.1 with long-slit Hα spectroscopy from Pizagno et al. (2007, Cat. J/AJ/134/945) and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ~170000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). (4 data files).

Damage Accumulation in Silica Glass Nanofibers.

PubMed

Bonfanti, Silvia; Ferrero, Ezequiel E; Sellerio, Alessandro L; Guerra, Roberto; Zapperi, Stefano

2018-06-06

The origin of the brittle-to-ductile transition, experimentally observed in amorphous silica nanofibers as the sample size is reduced, is still debated. Here we investigate the issue by extensive molecular dynamics simulations at low and room temperatures for a broad range of sample sizes, with open and periodic boundary conditions. Our results show that small sample-size enhanced ductility is primarily due to diffuse damage accumulation, that for larger samples leads to brittle catastrophic failure. Surface effects such as boundary fluidization contribute to ductility at room temperature by promoting necking, but are not the main driver of the transition. Our results suggest that the experimentally observed size-induced ductility of silica nanofibers is a manifestation of finite-size criticality, as expected in general for quasi-brittle disordered networks.

Determination of element composition and extraterrestrial material occurrence in moss and lichen samples from King George Island (Antarctica) using reactor neutron activation analysis and SEM microscopy.

PubMed

Mróz, Tomasz; Szufa, Katarzyna; Frontasyeva, Marina V; Tselmovich, Vladimir; Ostrovnaya, Tatiana; Kornaś, Andrzej; Olech, Maria A; Mietelski, Jerzy W; Brudecki, Kamil

2018-01-01

Seven lichens (Usnea antarctica and U. aurantiacoatra) and nine moss samples (Sanionia uncinata) collected in King George Island were analyzed using instrumental neutron activation analysis, and concentration of major and trace elements was calculated. For some elements, the concentrations observed in moss samples were higher than corresponding values reported from other sites in the Antarctica, but in the lichens, these were in the same range of concentrations. Scanning electron microscopy (SEM) and statistical analysis showed large influence of volcanic-origin particles. Also, the interplanetary cosmic particles (ICP) were observed in investigated samples, as mosses and lichens are good collectors of ICP and micrometeorites.

Effects of a pulsed Nd:YAG laser on enamel and dentin

NASA Astrophysics Data System (ADS)

Myers, Terry D.

1990-06-01

Enamel and dentin samples were exposed extraorally to a pulsed neodymium yttriuma1uminumgarnet (Nd:YAG) laser. The lased samples were observed using both scanning electron microscopy and histological techniques to determine the effects of the laser. The present study has provided the following points: (1) Properly treated, enamel can be 1aser etched to a depth comparable to that achieved with phosphoric acid etching; and (2) both carious and noncarious dentin can be vaporized by the Nd:YAG laser. No cracking or chipping of any enamel or dentin sample was observed histologically or under the SEM.

Frictional Characteristics of graphene

NASA Astrophysics Data System (ADS)

Lee, Changgu; Carpick, Robert; Hone, James

2009-03-01

The frictional characteristics of graphene were characterized using friction force microscopy (FFM). The frictional force for monolayer graphene is more than twice that of bulk graphite, with 2,3, and 4 layer samples showing a monotonic decrease in friction with increasing sample thickness. Measurements on suspended graphene membranes show identical results, ruling out substrate effects as the cause of the observed variation. Likewise, the adhesion force is identical for all samples. The frictional force is independent of load within experimental uncertainty, consistent with previous measurements on graphite. We consider several possible explanations for the origin of the observed thickness dependence.

Re-evaluation of groundwater monitoring data for glyphosate and bentazone by taking detection limits into account.

PubMed

Hansen, Claus Toni; Ritz, Christian; Gerhard, Daniel; Jensen, Jens Erik; Streibig, Jens Carl

2015-12-01

Current regulatory assessment of pesticide contamination of Danish groundwater is exclusively based on samples with pesticide concentrations above detection limit. Here we demonstrate that a realistic quantification of pesticide contamination requires the inclusion of "non-detect" samples i.e. samples with concentrations below the detection limit, as left-censored observations. The median calculated pesticide concentrations are shown to be reduced 10(4) to 10(5) fold for two representative herbicides (glyphosate and bentazone) relative to the median concentrations based upon observations above detection limits alone. Copyright © 2015 Elsevier B.V. All rights reserved.

Alkali metal intercalated fullerene-like MS(2) (M = W, Mo) nanoparticles and their properties.

PubMed

Zak, Alla; Feldman, Yishay; Lyakhovitskaya, Vera; Leitus, Gregory; Popovitz-Biro, Ronit; Wachtel, Ellen; Cohen, Hagai; Reich, Shimon; Tenne, Reshef

2002-05-01

Layered metal disulfides-MS(2) (M = Mo, W) in the form of fullerene-like nanoparticles and in the form of platelets (crystallites of the 2H polytype) have been intercalated by exposure to alkali metal (potassium and sodium) vapor using a two-zone transport method. The composition of the intercalated systems was established using X-ray energy dispersive spectrometer and X-ray photoelectron spectroscopy (XPS). The alkali metal concentration in the host lattice was found to depend on the kind of sample and the experimental conditions. Furthermore, an inhomogeneity of the intercalated samples was observed. The product consisted of both nonintercalated and intercalated phases. X-ray diffraction analysis and transmission electron microscopy of the samples, which were not exposed to the ambient atmosphere, showed that they suffered little change in their lattice parameters. On the other hand, after exposure to ambient atmosphere, substantial increase in the interplanar spacing (3-5 A) was observed for the intercalated phases. Insertion of one to two water molecules per intercalated metal atom was suggested as a possible explanation for this large expansion along the c-axis. Deintercalation of the hydrated alkali atoms and restacking of the MS(2) layers was observed in all the samples after prolonged exposure to the atmosphere. Electric field induced deintercalation of the alkali metal atoms from the host lattice was also observed by means of the XPS technique. Magnetic moment measurements for all the samples indicate a diamagnetic to paramagnetic transition after intercalation. Measurements of the transport properties reveal a semiconductor to metal transition for the heavily K intercalated 2H-MoS(2). Other samples show several orders of magnitude decrease in resistivity and two- to five-fold decrease in activation energies upon intercalation. These modifications are believed to occur via charge transfer from the alkali metal to the conduction band of the host lattice. Recovery of the pristine compound properties (diamagnetism and semiconductivity) was observed as a result of deintercalation.

Increased recovery of touch DNA evidence using FTA paper compared to conventional collection methods.

PubMed

Kirgiz, Irina A; Calloway, Cassandra

2017-04-01

Tape lifting and FTA paper scraping methods were directly compared to traditional double swabbing for collecting touch DNA from car steering wheels (n = 70 cars). Touch DNA was collected from the left or right side of each steering wheel (randomized) using two sterile cotton swabs, while the other side was sampled using water-soluble tape or FTA paper cards. DNA was extracted and quantified in duplicate using qPCR. Quantifiable amounts of DNA were detected for 100% of the samples (n = 140) collected independent of the method. However, the DNA collection yield was dependent on the collection method. A statistically significant difference in DNA yield was observed between FTA scraping and double swabbing methods (p = 0.0051), with FTA paper collecting a two-fold higher amount. Statistical analysis showed no significant difference in DNA yields between the double swabbing and tape lifting techniques (p = 0.21). Based on the DNA concentration required for 1 ng input, 47% of the samples collected using FTA paper would be expected to yield a short tandem repeat (STR) profile compared to 30% and 23% using double swabbing or tape, respectively. Further, 55% and 77% of the samples collected using double swabbing or tape, respectively, did not yield a high enough DNA concentration for the 0.5 ng of DNA input recommended for conventional STR kits and would be expected to result in a partial or no profile compared to 35% of the samples collected using FTA paper. STR analysis was conducted for a subset of the higher concentrated samples to confirm that the DNA collected from the steering wheel was from the driver. 32 samples were selected with DNA amounts of at least 1 ng total DNA (100 pg/μl when concentrated if required). A mixed STR profile was observed for 26 samples (88%) and the last driver was the major DNA contributor for 29 samples (94%). For one sample, the last driver was the minor DNA contributor. A full STR profile of the last driver was observed for 21 samples (69%) and a partial profile was observed for nine samples (25%); STR analysis failed for two samples collected using tape (6%). In conclusion, we show that the FTA paper scraping method has the potential to collect higher DNA yields from touch DNA evidence deposited on non-porous surfaces often encountered in criminal cases compared to conventional methods. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Characterization of porous nickel-titanium alloys for medical applications

NASA Astrophysics Data System (ADS)

Hernandez Tenorio, Rommy

The purpose of this study is to investigate the electrochemical behaviour of porous NiTi alloys provided by different sources. In order to achieve this goal, a systematic characterization of the physical and chemical properties by different techniques and new approaches were conducted. The martensite-austenite phase transition was determined by the use of the Differential scanning Calorimetry (DSC). The morphological characteristics (porosity and roughness) were measured with the Scanning Electron Microscopy (SEM). The surface chemical composition of the samples was identified by the use of X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). In the case of porous material the biomechanical compatibility is closely related to the porosity distribution of the sample. To describe appropriately the influence of this parameter on the properties of NiTi, four types of materials provided by different sources were analyzed. The samples were produced by Self-propagating High-temperature Synthesis (SHS) procedure. A heat treatment was applied in order to release internal stress created during forming processes, one series of specimens from each type was submitted to an annealing process during 30 min at 550°C in an air atmosphere. Its influence on the properties of the materials was also evaluated. Our first results showed that despite the fact that all the materials present different pore size, all the samples exhibited an open and interconnected porosity that promotes a good fixation and bone ingrowth within their structure. The thermal analysis showed that the temperature of the inception of the martensite-austenite phase transition occurs at 60°C, which is greater than the body temperature by 20°C. The microscopic analysis for the samples revealed that the heat treatment did not generate any morphological changes. The XPS study indicated that the surface oxidation occurs after the heat treatment. This oxide layer has a different thickness for the materials in the range of 310--3990 A. The evaluation of the corrosion resistance of the four porous NiTi alloys showed a correlation between the chemical composition, pore size and the electrochemical behaviour. In particular it was found that the corrosion resistance is related to the surface chemical composition of the electrodes rather than to their surface morphology. First we observed that the impact of the annealing process varies with the type of sample. The non-treated samples showed higher breakdown potentials and also bigger pores. The materials with a pore size in the range of 80-120mum showed different behaviours, one material (B) showed no visible effect while the other two (A and C) exhibited a decrease of the breakdown potential value. The material with the smallest pore size 35-50mum showed an important improvement after the heat treatment. Therefore, we can conclude, that the surface treatment used in our investigations led to an improvement of the corrosion resistance for small pores whereas a decrease was observed for bigger pores. On the other hand the lower corrosion rates observed on treated samples are an indication of the high corrosion resistance compare to those non-treated. In this case we observed that the one material (B) exhibited the highest corrosion rate presented a difference in the chemical composition as shown by XPS analysis. Moreover, the absence of intermediate titanium oxides (Ti2+ and Ti3+) was observed. As these oxides were identified in the other materials (A, C and D) we conclude that the presence of intermediate titanium oxides on surface chemical composition of the samples results on better corrosion rates and improved corrosion resistance. The Spectroelectrochemistry evaluation showed that solid electropolished sample and solid mechanopolished samples exhibited a better corrosion resistance than porous mechanopolished samples. However the solid mechanopolished sample exhibits a higher corrosion rate almost as high as the one showed by the porous sample. On the other hand a higher breakdown potential was measured porous samples compared to previous studies. However this sample shows a higher susceptibility for pitting and crevice corrosion. This can be explained by the porous structure of the sample. The FTIR results showed the interactions between the solution and the samples. It can be observed that each sample exhibit a particular behaviour. The porous sample as well as the solid samples showed Ti-OH interactions. Moreover both solid samples exhibited another peak corresponding to the OTi(OH)CCH interaction, which is explained by the chemical composition of the electrolyte, in this case the Hank's solution that has a certain amount of glucose. However an inversion of the peak is observed in both samples, this direction change can be attributed to the surface treatment. The electropolished sample showed a more stable behaviour mean while the mechanopolished sample exhibited a change during the reverse scan. (Abstract shortened by UMI.)

Effects of Neutron Irradiation and Post-irradiation Annealing on the Microstructure of HT-UPS Stainless Steel

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

Xu, Chi; Chen, Wei-Ying; Zhang, Xuan

Microstructural changes resulted from neutron irradiation and post-irradiation annealing in a high-temperature ultra-fine precipitate strengthened (HT-UPS) stainless steel were characterized using transmission electron microscopy (TEM) and atom probe tomography (APT). Three HT-UPS samples were neutron-irradiated to 3 dpa at 500 °C, and after irradiation, two of them were annealed for 1 h at 600 °C and 700 °C, respectively. Frank dislocation loops were the dominant defect structure in both the as-irradiated and 600 °C post-irradiation-annealed (PIAed) samples, and the loop sizes and densities were similar in these two samples. Unfaulted dislocation loops were observed in the 700 °C PIAed sample, and the loop density was greatly reducedmore » in comparison with that in the as-irradiated sample. Nano-sized MX precipitates were observed under TEM in the 700 °C PIAed sample, but not in the 600 °C PIAed or the as-irradiated samples. The titanium-rich clusters were identified in all three samples using APT. The post-irradiation annealing (PIA) caused the growth of the Ti-rich clusters with a stronger effect at 700 °C than at 600 °C. The irradiation caused elemental segregations at the grain boundary and the grain interior, and the grain boundary segregation behavior is consistent with observations in other irradiated austenitic steels. APT results showed that PIA reduced the magnitude of irradiation induced segregations.« less

Studies of Minerals, Organic and Biogenic Materials through Time-Resolved Raman Spectroscopy

NASA Technical Reports Server (NTRS)

Garcia, Christopher S.; Abedin, M. Nurul; Ismail, Syed; Sharma, Shiv K.; Misra, Anupam K.; Nyugen, Trac; Elsayed-Ali, hani

2009-01-01

A compact remote Raman spectroscopy system was developed at NASA Langley Research center and was previously demonstrated for its ability to identify chemical composition of various rocks and minerals. In this study, the Raman sensor was utilized to perform time-resolved Raman studies of various samples such as minerals and rocks, Azalea leaves and a few fossil samples. The Raman sensor utilizes a pulsed 532 nm Nd:YAG laser as excitation source, a 4-inch telescope to collect the Raman-scattered signal from a sample several meters away, a spectrograph equipped with a holographic grating, and a gated intensified CCD (ICCD) camera system. Time resolved Raman measurements were carried out by varying the gate delay with fixed short gate width of the ICCD camera, allowing measurement of both Raman signals and fluorescence signals. Rocks and mineral samples were characterized including marble, which contain CaCO3. Analysis of the results reveals the short (approx.10-13 s) lifetime of the Raman process, and shows that Raman spectra of some mineral samples contain fluorescence emission due to organic impurities. Also analyzed were a green (pristine) and a yellow (decayed) sample of Gardenia leaves. It was observed that the fluorescence signals from the green and yellow leaf samples showed stronger signals compared to the Raman lines. Moreover, it was also observed that the fluorescence of the green leaf was more intense and had a shorter lifetime than that of the yellow leaf. For the fossil samples, Raman shifted lines could not be observed due the presence of very strong short-lived fluorescence.

Survival of Listeria monocytogenes in vanilla-flavored soy and dairy products stored at 8 degrees C.

PubMed

Tipparaju, Sireesha; Ravishankar, Sadhana; Slade, Peter J

2004-02-01

The survival of Listeria monocytogenes V37 in vanilla-flavored yogurt (low-fat and nonfat) and soy milk (low-fat and Plus) stored at 8 degrees C for 31 days was investigated. Commercial samples of yogurt and soy milk were used. These samples were inoculated with either 10(4) or 10(7) CFU of L. monocytogenes per ml. Sampling was carried out every 3 to 4 days initially and was then carried out weekly, for a total storage time of 31 days. Each time a sample was collected, the pH of the sample was measured. After 31 days, low-fat plain, low-fat vanilla, and nonfat plain yogurt samples inoculated with 10(4) CFU/ml showed 2.5-log reductions in viable cell populations, and nonfat vanilla yogurt showed a 3.5-log reduction. For yogurt inoculated with 10(7) CFU/ml, reductions of 2.5 log CFU/ml were observed for plain low-fat and nonfat yogurts, and reductions of 5 log CFU/ml were observed for vanilla-flavored low-fat and nonfat yogurts. In vanilla-flavored and plain low-fat and Plus soy milk samples, cell counts increased from 10(4) and 10(7) CFU/ml to 10(9) CFU/ml at 7 and 3 days of storage, respectively, at 8 degrees C. Coagulation in soy milk samples was observed when the cell population reached 10(9) CFU/ml. In soy milk, the L. monocytogenes population did not change for up to 31 days. Vanillin had an inhibitory effect on L. monocytogenes in yogurt but not in soy milk.

Drinking water quality in six small tea gardens of Sonitpur District of Assam, India, with special reference to heavy metals.

PubMed

Dutta, Joydev; Chetia, Mridul; Misra, A K

2011-10-01

Contamination of drinking water by arsenic and other heavy metals and their related toxicology is a serious concern now-a-days. Millions of individual world-wide are suffering from the arsenic and other heavy metal related diseases due to the consumption of contaminated groundwater. 60 water samples from different sources of 6 small tea gardens of Sonitpur district were collected to study the potability of water for drinking purposes. The water samples collected from sources like tube wells, ring wells and ponds were analyzed for arsenic, heavy metals like iron, manganese and mercury with sodium, potassium, calcium, magnesium, pH, total hardness, chloride, fluoride and sulphate. Some drain water samples of the tea garden areas were also collected to analyze the above mentioned water parameters to see the contamination level. Experiments revealed that 78% samples of total collection had arsenic content above the permissible limit (0.01 ppm) of WHO guideline value for drinking water. The highest arsenic was observed 0.09 ppm at one sample of Gobindra Dahal tea garden of Gohpur sub division of Sonitpur district. 94% samples had contamination due to manganese 39% samples had iron and 44% samples had Hg. The water quality data was subjected to some statistical treatments like NDA, cluster analysis and pearson correlation to observe the distribution pattern of the different water quality parameters. A strong pearson correlation coefficient was observed between parameters-arsenic and manganese (0.865) and arsenic and mercury (0.837) at 0.01 level, indicated the same sources of drinking water contamination.

Toxicological and chemical insights into representative source and drinking water in eastern China.

PubMed

Shi, Peng; Zhou, Sicong; Xiao, Hongxia; Qiu, Jingfan; Li, Aimin; Zhou, Qing; Pan, Yang; Hollert, Henner

2018-02-01

Drinking water safety is continuously threatened by the emergence of numerous toxic organic pollutants (TOPs) in environmental waters. In this study, an approach integrating in vitro bioassays and chemical analyses was performed to explore toxicological profiles of representative source and drinking water from waterworks of the Yangtze River (Yz), Taihu Lake (Th), and the Huaihe River (Hh) basins in eastern China. Overall, 34 of 96 TOPs were detected in all water samples, with higher concentrations in both source and drinking water samples of Hh, and pollutant profiles also differed across different river basins. Non-specific bioassays indicated that source water samples of Hh waterworks showed higher genotoxicity and mutagenicity than samples of Yz and Th. An EROD assay demonstrated dioxin-like toxicity which was detected in 5 of 7 source water samples, with toxin concentration levels ranging from 62.40 to 115.51 picograms TCDD equivalents per liter of water (eq./L). PAHs and PCBs were not the main contributors to observed dioxin-like toxicity in detected samples. All source water samples induced estrogenic activities of 8.00-129.00 nanograms 17β-estradiol eq./L, and estrogens, including 17α-ethinylestradiol and estriol, contributed 40.38-84.15% of the observed activities in examined samples. While drinking water treatments efficiently removed TOPs and their toxic effects, and estrogenic activity was still observed in drinking water samples of Hh. Altogether, this study indicated that the representative source water in eastern China, especially that found in Hh, may negatively affect human health, a finding that demonstrates an urgent requirement for advanced drinking water treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rectal and Naris Swabs: Practical and Informative Samples for Analyzing the Microbiota of Critically Ill Patients.

PubMed

Bansal, Saumya; Nguyen, Jenny P; Leligdowicz, Aleksandra; Zhang, Yu; Kain, Kevin C; Ricciuto, Daniel R; Coburn, Bryan

2018-06-27

Commensal microbiota are immunomodulatory, and their pathological perturbation can affect the risk and outcomes of infectious and inflammatory diseases. Consequently, the human microbiota is an emerging diagnostic and therapeutic target in critical illness. In this study, we compared four sample types-rectal, naris, and antecubital swabs and stool samples-for 16S rRNA gene microbiota sequencing in intensive care unit (ICU) patients. Stool samples were obtained in only 31% of daily attempts, while swabs were reliably obtained (≥97% of attempts). Swabs were compositionally distinct by anatomical site, and rectal swabs identified within-patient temporal trends in microbiota composition. Rectal swabs from ICU patients demonstrated differences from healthy stool similar to those observed in comparing stool samples from ICU patients to those from the same healthy controls. Rectal swabs are a useful complement to other sample types for analysis of the intestinal microbiota in critical illness, particularly when obtaining stool may not be feasible or practical. IMPORTANCE Perturbation of the microbiome has been correlated with various infectious and inflammatory diseases and is common in critically ill patients. Stool is typically used to sample the microbiota in human observational studies; however, it is often unavailable for collection from critically ill patients, reducing its utility as a sample type to study this population. Our research identified alternatives to stool for sampling the microbiota during critical illness. Rectal and naris swabs were practical alternatives for use in these patients, as they were observed to be more reliably obtained than stool, were suitable for culture-independent analysis, and successfully captured within- and between-patient microbiota differences. Copyright © 2018 Bansal et al.

28 CFR 552.12 - Close observation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... urine sample is required prior to releasing the inmate from close observation. (2) The light will be kept on at all times. (3) No inmate under close observation status may be allowed to come into contact...

28 CFR 552.12 - Close observation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... urine sample is required prior to releasing the inmate from close observation. (2) The light will be kept on at all times. (3) No inmate under close observation status may be allowed to come into contact...

Sciencing with Mother Goose: Observation Activities with Chicken Little.

ERIC Educational Resources Information Center

Angus, Carolyn

1996-01-01

Provides sample observation activities to accompany the nursery tale of Chicken Little. Includes five activities that involve the skills of observing, communicating, comparing, ordering, and categorizing to engage students in hands-on science. (DDR)

Sample sizes and model comparison metrics for species distribution models

Treesearch

B.B. Hanberry; H.S. He; D.C. Dey

2012-01-01

Species distribution models use small samples to produce continuous distribution maps. The question of how small a sample can be to produce an accurate model generally has been answered based on comparisons to maximum sample sizes of 200 observations or fewer. In addition, model comparisons often are made with the kappa statistic, which has become controversial....

23 CFR Appendix A to Part 1340 - Sample Design

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Sample Design A Appendix A to Part 1340 Highways... OBSERVATIONAL SURVEYS OF SEAT BELT USE Pt. 1340, App. A Appendix A to Part 1340—Sample Design Following is a description of a sample design that meets the final survey guidelines and, based upon NHTSA's experience in...

Mapping the EORTC QLQ-C30 onto the EQ-5D-3L: assessing the external validity of existing mapping algorithms.

PubMed

Doble, Brett; Lorgelly, Paula

2016-04-01

To determine the external validity of existing mapping algorithms for predicting EQ-5D-3L utility values from EORTC QLQ-C30 responses and to establish their generalizability in different types of cancer. A main analysis (pooled) sample of 3560 observations (1727 patients) and two disease severity patient samples (496 and 93 patients) with repeated observations over time from Cancer 2015 were used to validate the existing algorithms. Errors were calculated between observed and predicted EQ-5D-3L utility values using a single pooled sample and ten pooled tumour type-specific samples. Predictive accuracy was assessed using mean absolute error (MAE) and standardized root-mean-squared error (RMSE). The association between observed and predicted EQ-5D utility values and other covariates across the distribution was tested using quantile regression. Quality-adjusted life years (QALYs) were calculated using observed and predicted values to test responsiveness. Ten 'preferred' mapping algorithms were identified. Two algorithms estimated via response mapping and ordinary least-squares regression using dummy variables performed well on number of validation criteria, including accurate prediction of the best and worst QLQ-C30 health states, predicted values within the EQ-5D tariff range, relatively small MAEs and RMSEs, and minimal differences between estimated QALYs. Comparison of predictive accuracy across ten tumour type-specific samples highlighted that algorithms are relatively insensitive to grouping by tumour type and affected more by differences in disease severity. Two of the 'preferred' mapping algorithms suggest more accurate predictions, but limitations exist. We recommend extensive scenario analyses if mapped utilities are used in cost-utility analyses.

Factors controlling precision and accuracy in isotope-ratio-monitoring mass spectrometry

NASA Technical Reports Server (NTRS)

Merritt, D. A.; Hayes, J. M.

1994-01-01

The performance of systems in which picomole quantities of sample are mixed with a carrier gas and passed through an isotope-ratio mass spectrometer system was examined experimentally and theoretically. Two different mass spectrometers were used, both having electron-impact ion sources and Faraday cup collector systems. One had an accelerating potential of 10kV and accepted 0.2 mL of He/min, producing, under those conditions, a maximum efficiency of 1 CO2 molecular ion collected per 700 molecules introduced. Comparable figures for the second instrument were 3 kV, 0.5 mL of He/min, and 14000 molecules/ion. Signal pathways were adjusted so that response times were <200 ms. Sample-related ion currents appeared as peaks with widths of 3-30 s. Isotope ratios were determined by comparison to signals produced by standard gases. In spite of rapid variations in signals, observed levels of performance were within a factor of 2 of shot-noise limits. For the 10-kV instrument, sample requirements for standard deviations of 0.1 and 0.5% were 45 and 1.7 pmol, respectively. Comparable requirements for the 3-kV instrument were 900 and 36 pmol. Drifts in instrumental characteristics were adequately neutralized when standards were observed at 20-min intervals. For the 10-kV instrument, computed isotopic compositions were independent of sample size and signal strength over the ranges examined. Nonlinearities of <0.04%/V were observed for the 3-kV system. Procedures for observation and subtraction of background ion currents were examined experimentally and theoretically. For sample/ background ratios varying from >10 to 0.3, precision is expected and observed to decrease approximately 2-fold and to depend only weakly on the precision with which background ion currents have been measured.

Evaluating fungal populations by genera/species on wide body commercial passenger aircraft and in airport terminals.

PubMed

McKernan, Lauralynn Taylor; Burge, Harriet; Wallingford, Kenneth M; Hein, Misty J; Herrick, Robert

2007-04-01

Given the potential health effects of fungi and the amount of time aircrew and passengers spend inside aircraft, it is important to study fungal populations in the aircraft environment. Research objectives included documenting the genera/species of airborne culturable fungal concentrations and total spore concentrations on a twin-aisle wide body commercial passenger aircraft. Twelve flights between 4.5 and 6.5 h in duration on Boeing 767 (B-767) aircraft were evaluated. Two air cooling packs and 50% recirculation rate (i.e. 50:50 mix of outside air and filtered inside air) were utilized during flight operations. Passenger occupancy rates varied from 67 to 100%. N-6 impactors and total spore traps were used to collect sequential, triplicate air samples in the front and rear of coach class during six sampling intervals throughout each flight: boarding, mid-climb, early cruise, mid-cruise, late cruise and deplaning. Comparison air samples were also collected inside and outside the airport terminals at the origin and destination cities resulting in a total of 522 culturable and 517 total spore samples. A total of 45 surface wipe samples were collected using swabs onboard the aircraft and inside the airport terminals. A variety of taxa were observed in the culturable and total spore samples. A frequency analysis of the fungal data indicated that Cladosporium, Aspergillus and Penicillium were predominant genera in the culturable samples whereas Cladosporium, Basidiospores and Penicillium/Aspergillus were predominant in the total spore samples. Fungal populations observed inside the aircraft were comprised of similar genera, detected significantly less frequently and with lower mean concentrations than those observed in typical office buildings. Although sources internal to the aircraft could not be ruled out, our data demonstrate the importance of passenger activity as the source of the fungi observed on aircraft. Isolated fungal peak events occurred occasionally when concentrations of a particular genus or species rose sharply inside the cabin for a limited period. Overall, our research demonstrates that on the sampled flights the B-767 filtration system operated efficiently to remove fungal spores when two air cooling packs and 50% recirculation rate were utilized during flight operations.

OCAMS: The OSIRIS-REx Camera Suite

NASA Astrophysics Data System (ADS)

Rizk, B.; Drouet d'Aubigny, C.; Golish, D.; Fellows, C.; Merrill, C.; Smith, P.; Walker, M. S.; Hendershot, J. E.; Hancock, J.; Bailey, S. H.; DellaGiustina, D. N.; Lauretta, D. S.; Tanner, R.; Williams, M.; Harshman, K.; Fitzgibbon, M.; Verts, W.; Chen, J.; Connors, T.; Hamara, D.; Dowd, A.; Lowman, A.; Dubin, M.; Burt, R.; Whiteley, M.; Watson, M.; McMahon, T.; Ward, M.; Booher, D.; Read, M.; Williams, B.; Hunten, M.; Little, E.; Saltzman, T.; Alfred, D.; O'Dougherty, S.; Walthall, M.; Kenagy, K.; Peterson, S.; Crowther, B.; Perry, M. L.; See, C.; Selznick, S.; Sauve, C.; Beiser, M.; Black, W.; Pfisterer, R. N.; Lancaster, A.; Oliver, S.; Oquest, C.; Crowley, D.; Morgan, C.; Castle, C.; Dominguez, R.; Sullivan, M.

2018-02-01

The OSIRIS-REx Camera Suite (OCAMS) will acquire images essential to collecting a sample from the surface of Bennu. During proximity operations, these images will document the presence of satellites and plumes, record spin state, enable an accurate model of the asteroid's shape, and identify any surface hazards. They will confirm the presence of sampleable regolith on the surface, observe the sampling event itself, and image the sample head in order to verify its readiness to be stowed. They will document Bennu's history as an example of early solar system material, as a microgravity body with a planetesimal size-scale, and as a carbonaceous object. OCAMS is fitted with three cameras. The MapCam will record color images of Bennu as a point source on approach to the asteroid in order to connect Bennu's ground-based point-source observational record to later higher-resolution surface spectral imaging. The SamCam will document the sample site before, during, and after it is disturbed by the sample mechanism. The PolyCam, using its focus mechanism, will observe the sample site at sub-centimeter resolutions, revealing surface texture and morphology. While their imaging requirements divide naturally between the three cameras, they preserve a strong degree of functional overlap. OCAMS and the other spacecraft instruments will allow the OSIRIS-REx mission to collect a sample from a microgravity body on the same visit during which it was first optically acquired from long range, a useful capability as humanity reaches out to explore near-Earth, Main-Belt and Jupiter Trojan asteroids.

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

Dalal, M.; Mallick, A.; Mahapatra, A.S.

Highlights: • Cation distribution in tetrahedral and octahedral sites of spinel Ni{sub 0.4}Zn{sub 0.4}Co{sub 0.2}Fe{sub 2}O{sub 4}. • Structural analysis of observed X-ray diffraction pattern using Rietveld method. • Study of hyperfine behaviour using Mössbauer spectroscopy. • Static and dynamic magnetic measurements. • Correlation of cation distributions obtained from Rietveld analysis with the results of magnetic and Mössbauer effect measurements. - Abstract: Nanoparticles of Ni{sub 0.4}Zn{sub 0.4}Co{sub 0.2}Fe{sub 2}O{sub 4} are prepared by a simple co-precipitation method. The as dried sample is heat treated at 400, 500, 600, 700 and 800 °C to obtain different sizes of nanoparticles. The crystallographicmore » phase of the samples is confirmed analyzing observed X-ray diffraction (XRD) by Rietveld method. Hyperfine parameters of the samples are derived from room temperature (RT) Mössbauer spectra of the samples. Magnetic properties of the samples are investigated by static and dynamic hysteresis loops. Different magneto-crystalline parameters are calculated from the variation of magnetization with temperature (M–T curve) under zero field cooled (ZFC) and field cooled (FC) conditions of the as dried sample. The cation distribution estimated from Rietveld analysis are correlated with the results of magnetic and Mössbauer effect measurements. The observed high value of saturation magnetization (72.7 emu/g at RT) of the sample annealed at 800 °C would be interesting for applications in different electromagnetic devices.« less

Correlated microanalysis of cometary organic grains returned by Stardust

NASA Astrophysics Data System (ADS)

de Gregorio, Bradley T.; Stroud, Rhonda M.; Cody, George D.; Nittler, Larry R.; David Kilcoyne, A. L.; Wirick, Sue

2011-09-01

Abstract- Carbonaceous matter in Stardust samples returned from comet 81P/Wild 2 is observed to contain a wide variety of organic functional chemistry. However, some of this chemical variety may be due to contamination or alteration during particle capture in aerogel. We investigated six carbonaceous Stardust samples that had been previously analyzed and six new samples from Stardust Track 80 using correlated transmission electron microscopy (TEM), X-ray absorption near-edge structure spectroscopy (XANES), and secondary ion mass spectroscopy (SIMS). TEM revealed that samples from Track 35 containing abundant aliphatic XANES signatures were predominantly composed of cometary organic matter infilling densified silica aerogel. Aliphatic organic matter from Track 16 was also observed to be soluble in the epoxy embedding medium. The nitrogen-rich samples in this study (from Track 22 and Track 80) both contained metal oxide nanoparticles, and are likely contaminants. Only two types of cometary organic matter appear to be relatively unaltered during particle capture. These are (1) polyaromatic carbonyl-containing organic matter, similar to that observed in insoluble organic matter (IOM) from primitive meteorites, interplanetary dust particles (IDPs), and in other carbonaceous Stardust samples, and (2) highly aromatic refractory organic matter, which primarily constitutes nanoglobule-like features. Anomalous isotopic compositions in some of these samples also confirm their cometary heritage. There also appears to be a significant labile aliphatic component of Wild 2 organic matter, but this material could not be clearly distinguished from carbonaceous contaminants known to be present in the Stardust aerogel collector.

Detection of Prosthetic Hip Infection at Revision Arthroplasty by Immunofluorescence Microscopy and PCR Amplification of the Bacterial 16S rRNA Gene

PubMed Central

Tunney, Michael M.; Patrick, Sheila; Curran, Martin D.; Ramage, Gordon; Hanna, Donna; Nixon, James R.; Gorman, Sean P.; Davis, Richard I.; Anderson, Neil

1999-01-01

In this study the detection rates of bacterial infection of hip prostheses by culture and nonculture methods were compared for 120 patients with total hip revision surgery. By use of strict anaerobic bacteriological practice during the processing of samples and without enrichment, the incidence of infection by culture of material dislodged from retrieved prostheses after ultrasonication (sonicate) was 22%. Bacteria were observed by immunofluorescence microscopy in 63% of sonicate samples with a monoclonal antibody specific for Propionibacterium acnes and polyclonal antiserum specific for Staphylococcus spp. The bacteria were present either as single cells or in aggregates of up to 300 bacterial cells. These aggregates were not observed without sonication to dislodge the biofilm. Bacteria were observed in all of the culture-positive samples, and in some cases in which only one type of bacterium was identified by culture, both coccoid and coryneform bacteria were observed by immunofluorescence microscopy. Bacteria from skin-flake contamination were readily distinguishable from infecting bacteria by immunofluorescence microscopy. Examination of skin scrapings did not reveal large aggregates of bacteria but did reveal skin cells. These were not observed in the sonicates. Bacterial DNA was detected in 72% of sonicate samples by PCR amplification of a region of the bacterial 16S rRNA gene with universal primers. All of the culture-positive samples were also positive for bacterial DNA. Evidence of high-level infiltration either of neutrophils or of lymphocytes or macrophages into associated tissue was observed in 73% of patients. Our results indicate that the incidence of prosthetic joint infection is grossly underestimated by current culture detection methods. It is therefore imperative that current clinical practice with regard to the detection and subsequent treatment of prosthetic joint infection be reassessed in the light of these results. PMID:10488193

Observer Error when Measuring Safety-Related Behavior: Momentary Time Sampling versus Whole-Interval Recording

ERIC Educational Resources Information Center

Taylor, Matthew A.; Skourides, Andreas; Alvero, Alicia M.

2012-01-01

Interval recording procedures are used by persons who collect data through observation to estimate the cumulative occurrence and nonoccurrence of behavior/events. Although interval recording procedures can increase the efficiency of observational data collection, they can also induce error from the observer. In the present study, 50 observers were…

VizieR Online Data Catalog: Lower main-sequence stars fundamental param. (Casagrande+, 2006)

NASA Astrophysics Data System (ADS)

Casagrande, L.; Portinari, L.; Flynn, C.

2007-06-01

To recover accurate bolometric fluxes and temperatures for the stars, we have obtained accurate and homogeneous Johnson-Cousins BV(RI)C and JHKs photometry for all the 186 stars in our initial sample. For most of the stars in our sample with declination north of DE=-25°, we have made our own photometric observations from April to December 2004. Observations were done from Finland in full remote mode, using the 35-cm telescope piggybacked on the Swedish 60-cm telescope located at La Palma in the Canary Islands. A SBIG charge-coupled device was used through all the observations. Johnson-Cousins BV(RI)C colours were obtained for all stars. Infrared JHKs photometry for the sample has been taken from the Two-Micron All-Sky Survey (2MASS) catalogue. (1 data file).

VizieR Online Data Catalog: Lower main-sequence stars fundamental param. (Casagrande+, 2006)

NASA Astrophysics Data System (ADS)

Casagrande, L.; Portinari, L.; Flynn, C.

2007-06-01

To recover accurate bolometric fluxes and temperatures for the stars, we have obtained accurate and homogeneous Johnson-Cousins BV(RI)C and JHKs photometry for all the 186 stars in our initial sample. For most of the stars in our sample with declination north of DE=-25{deg}, we have made our own photometric observations from April to December 2004. Observations were done from Finland in full remote mode, using the 35-cm telescope piggybacked on the Swedish 60-cm telescope located at La Palma in the Canary Islands. A SBIG charge-coupled device was used through all the observations. Johnson-Cousins BV(RI)C colours were obtained for all stars. Infrared JHKs photometry for the sample has been taken from the Two-Micron All-Sky Survey (2MASS) catalogue. (1 data file).

Sample holder for axial rotation of specimens in 3D microscopy.

PubMed

Bruns, T; Schickinger, S; Schneckenburger, H

2015-10-01

In common light microscopy, observation of samples is only possible from one perspective. However, especially for larger three-dimensional specimens observation from different views is desirable. Therefore, we are presenting a sample holder permitting rotation of the specimen around an axis perpendicular to the light path of the microscope. Thus, images can be put into a defined multidimensional context, enabling reliable three-dimensional reconstructions. The device can be easily adapted to a great variety of common light microscopes and is suitable for various applications in science, education and industry, where the observation of three-dimensional specimens is essential. Fluorescence z-projection images of copepods and ixodidae ticks at different rotation angles obtained by confocal laser scanning microscopy and light sheet fluorescence microscopy are reported as representative results. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

In situ alkali-silica reaction observed by x-ray microscopy

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

Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.

1997-04-01

In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques availablemore » for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.« less

High Strength and Ductility of Additively Manufactured 316L Stainless Steel Explained

NASA Astrophysics Data System (ADS)

Shamsujjoha, Md.; Agnew, Sean R.; Fitz-Gerald, James M.; Moore, William R.; Newman, Tabitha A.

2018-04-01

Structure-property relationships of an additively manufactured 316L stainless steel were explored. A scanning electron microscope and electron backscattered diffraction (EBSD) analysis revealed a fine cellular-dendritic (0.5 to 2 μm) substructure inside large irregularly shaped grains ( 100 μm). The cellular structure grows along the <100> crystallographic directions. However, texture analysis revealed that the main <100> texture component is inclined by 15 deg from the building direction. X-ray diffraction line profile analysis indicated a high dislocation density of 1 × 1015 m-2 in the as-built material, which correlates well with the observed EBSD microstructure and high-yield strength, via the traditional Taylor hardening equation. Significant variations in strain hardening behavior and ductility were observed for the horizontal (HB) and vertical (VB) built samples. Ductility of HB and VB samples measured 49 and 77 pct, respectively. The initial growth texture and subsequent texture evolution during tensile deformation are held responsible for the observed anisotropy. Notably, EBSD analysis of deformed samples showed deformation twins, which predominately form in the grains with <111> aligned parallel to the loading direction. The VB samples showed higher twinning activity, higher strain hardening rates at high strain, and therefore, higher ductility. Analysis of annealed samples revealed that the observed microstructures and properties are thermally stable, with only a moderate decrease in strength and very similar levels of ductility and anisotropy, compared with the as-built condition.

High Strength and Ductility of Additively Manufactured 316L Stainless Steel Explained

NASA Astrophysics Data System (ADS)

Shamsujjoha, Md.; Agnew, Sean R.; Fitz-Gerald, James M.; Moore, William R.; Newman, Tabitha A.

2018-07-01

Structure-property relationships of an additively manufactured 316L stainless steel were explored. A scanning electron microscope and electron backscattered diffraction (EBSD) analysis revealed a fine cellular-dendritic (0.5 to 2 μm) substructure inside large irregularly shaped grains ( 100 μm). The cellular structure grows along the <100> crystallographic directions. However, texture analysis revealed that the main <100> texture component is inclined by 15 deg from the building direction. X-ray diffraction line profile analysis indicated a high dislocation density of 1 × 1015 m-2 in the as-built material, which correlates well with the observed EBSD microstructure and high-yield strength, via the traditional Taylor hardening equation. Significant variations in strain hardening behavior and ductility were observed for the horizontal (HB) and vertical (VB) built samples. Ductility of HB and VB samples measured 49 and 77 pct, respectively. The initial growth texture and subsequent texture evolution during tensile deformation are held responsible for the observed anisotropy. Notably, EBSD analysis of deformed samples showed deformation twins, which predominately form in the grains with <111> aligned parallel to the loading direction. The VB samples showed higher twinning activity, higher strain hardening rates at high strain, and therefore, higher ductility. Analysis of annealed samples revealed that the observed microstructures and properties are thermally stable, with only a moderate decrease in strength and very similar levels of ductility and anisotropy, compared with the as-built condition.

Polarimetric imaging of uterine cervix: a case study.

PubMed

Pierangelo, Angelo; Nazac, André; Benali, Abdelali; Validire, Pierre; Cohen, Henri; Novikova, Tatiana; Ibrahim, Bicher Haj; Manhas, Sandeep; Fallet, Clément; Antonelli, Maria-Rosaria; Martino, Antonello-De

2013-06-17

We present a preliminary investigation of macroscopic polarimetric imaging of uterine cervix. Orthogonal state contrast (OSC) images of healthy and anomalous cervices have been taken in vivo at 550 nm. Four ex vivo cervix samples have been studied in full Muller polarimetry, at 550 nm and 700 nm, and characterized in detail by standard pathology. One sample was totally healthy, another one carried CIN lesions at very early stage (CIN1) in its visible exocervical region, while for the other two samples more advanced (CIN3) lesions were present, together with visible glandular epithelium (ectropion). Significant birefringence has been observed in the healthy regions of all six samples, both in vivo and ex vivo. Standard treatments of the Mueller images of the ex vivo samples allowed to quantify both retardation and depolarization. Retardation reached 60° in healthy regions, and disappeared in the anomalous regions of the other three ex vivo samples. The depolarization power was largest in healthy regions, and lower in CINs and ectropion. Possible origins of the observed effects are briefly discussed.

RBS/Channeling Studies of Swift Heavy Ion Irradiated GaN Layers

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

Sathish, N.; Dhamodaran, S.; Pathak, A. P.

2009-03-10

Epitaxial GaN layers grown by MOCVD on c-plane sapphire substrates were irradiated with 150 MeV Ag ions at a fluence of 5x10{sup 12} ions/cm{sup 2}. Samples used in this study are 2 {mu}m thick GaN layers, with and without a thin AlN cap-layer. Energy dependent RBS/Channeling measurements have been carried out on both irradiated and unirradiated samples for defects characterization. Observed results are compared and correlated with previous HRXRD, AFM and optical studies. The {chi}{sub min} values for unirradiated samples show very high value and the calculated defect densities are of the order of 10{sup 10} cm{sup -2} as expectedmore » in these samples. Effects of irradiation on these samples are different as initial samples had different defect densities. Epitaxial reconstruction of GaN buffer layer has been attributed to the observed changes, which are generally grown to reduce the strain between GaN and Sapphire.« less

Altitude profiles of total chlorinated paraffins in humus and spruce needles from the Alps (MONARPOP).

PubMed

Iozza, Saverio; Schmid, Peter; Oehme, Michael; Bassan, Rodolfo; Belis, Claudio; Jakobi, Gert; Kirchner, Manfred; Schramm, Karl-Werner; Kräuchi, Norbert; Moche, Wolfgang; Offenthaler, Ivo; Weiss, Peter; Simoncic, Primoz; Knoth, Wilhelm

2009-12-01

Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in the environment. CPs were analyzed in humus and needle samples, which were taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) at sampling sites of 7 different altitude profiles in the Alps. Gas chromatography combined with electron ionization tandem mass spectrometry (EI-MS/MS) was used for the determination of total CPs (sum of short, medium and long chain CPs). CPs were found in all samples; the concentrations varied between 7 and 199 ng g(-1) dry weight (dw) and within 26 and 460 ng g(-1) dw in humus and needle samples, respectively. A clear vertical tendency within the individual altitude profiles could not be ascertained. Within all altitude profiles, elevated concentrations were observed in humus samples taken between 700 and 900 m and between 1300 and 1500 m. In the needle samples no similar correlation could be observed due to higher variation of the data.

Sampling theory for asynoptic satellite observations. I Space-time spectra, resolution, and aliasing. II - Fast Fourier synoptic mapping

NASA Technical Reports Server (NTRS)

Salby, M. L.

1982-01-01

An evaluation of the information content of asynoptic data taken in the form of nadir sonde and limb scan observations is presented, and a one-to-one correspondence is established between the alias-free data and twice-daily synoptic maps. Attention is given to space and time limitations of sampling and the orbital geometry is discussed. The sampling pattern is demonstrated to determine unique space-time spectra at all wavenumbers and frequencies. Spectral resolution and aliasing are explored, while restrictions on sampling and information content are defined. It is noted that irregular sampling at high latitudes produces spurious contamination effects. An Asynoptic Sampling Theorem is thereby formulated, as is a Synoptic Retrieval Theorem, in the second part of the article. In the latter, a procedure is developed for retrieving the unique correspondence between the asymptotic data and the synoptic maps. Applications examples are provided using data from the Nimbus-6 satellite.

Virtual-system-coupled adaptive umbrella sampling to compute free-energy landscape for flexible molecular docking.

PubMed

Higo, Junichi; Dasgupta, Bhaskar; Mashimo, Tadaaki; Kasahara, Kota; Fukunishi, Yoshifumi; Nakamura, Haruki

2015-07-30

A novel enhanced conformational sampling method, virtual-system-coupled adaptive umbrella sampling (V-AUS), was proposed to compute 300-K free-energy landscape for flexible molecular docking, where a virtual degrees of freedom was introduced to control the sampling. This degree of freedom interacts with the biomolecular system. V-AUS was applied to complex formation of two disordered amyloid-β (Aβ30-35 ) peptides in a periodic box filled by an explicit solvent. An interpeptide distance was defined as the reaction coordinate, along which sampling was enhanced. A uniform conformational distribution was obtained covering a wide interpeptide distance ranging from the bound to unbound states. The 300-K free-energy landscape was characterized by thermodynamically stable basins of antiparallel and parallel β-sheet complexes and some other complex forms. Helices were frequently observed, when the two peptides contacted loosely or fluctuated freely without interpeptide contacts. We observed that V-AUS converged to uniform distribution more effectively than conventional AUS sampling did. © 2015 Wiley Periodicals, Inc.

Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample

DOEpatents

Maerefat, Nicida L.; Parmeswar, Ravi; Brinkmeyer, Alan D.; Honarpour, Mehdi

1994-01-01

A system for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

USGS Publications Warehouse

Keiter, David A.; Cunningham, Fred L.; Rhodes, Olin E.; Irwin, Brian J.; Beasley, James

2016-01-01

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocols with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig (Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. Knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

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

Keiter, David A.; Cunningham, Fred L.; Rhodes, Jr., Olin E.

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocolsmore » with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig ( Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. In conclusion, knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.« less

Optimization of Scat Detection Methods for a Social Ungulate, the Wild Pig, and Experimental Evaluation of Factors Affecting Detection of Scat.

PubMed

Keiter, David A; Cunningham, Fred L; Rhodes, Olin E; Irwin, Brian J; Beasley, James C

2016-01-01

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocols with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig (Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. Knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.

Optimization of scat detection methods for a social ungulate, the wild pig, and experimental evaluation of factors affecting detection of scat

DOE PAGES

Keiter, David A.; Cunningham, Fred L.; Rhodes, Jr., Olin E.; ...

2016-05-25

Collection of scat samples is common in wildlife research, particularly for genetic capture-mark-recapture applications. Due to high degradation rates of genetic material in scat, large numbers of samples must be collected to generate robust estimates. Optimization of sampling approaches to account for taxa-specific patterns of scat deposition is, therefore, necessary to ensure sufficient sample collection. While scat collection methods have been widely studied in carnivores, research to maximize scat collection and noninvasive sampling efficiency for social ungulates is lacking. Further, environmental factors or scat morphology may influence detection of scat by observers. We contrasted performance of novel radial search protocolsmore » with existing adaptive cluster sampling protocols to quantify differences in observed amounts of wild pig ( Sus scrofa) scat. We also evaluated the effects of environmental (percentage of vegetative ground cover and occurrence of rain immediately prior to sampling) and scat characteristics (fecal pellet size and number) on the detectability of scat by observers. We found that 15- and 20-m radial search protocols resulted in greater numbers of scats encountered than the previously used adaptive cluster sampling approach across habitat types, and that fecal pellet size, number of fecal pellets, percent vegetative ground cover, and recent rain events were significant predictors of scat detection. Our results suggest that use of a fixed-width radial search protocol may increase the number of scats detected for wild pigs, or other social ungulates, allowing more robust estimation of population metrics using noninvasive genetic sampling methods. Further, as fecal pellet size affected scat detection, juvenile or smaller-sized animals may be less detectable than adult or large animals, which could introduce bias into abundance estimates. In conclusion, knowledge of relationships between environmental variables and scat detection may allow researchers to optimize sampling protocols to maximize utility of noninvasive sampling for wild pigs and other social ungulates.« less

Validation of a polymerase chain reaction aided transcript titration assay (PATTY) for topoisomerase II in lung cancer samples.

PubMed

Dingemans, A M; Van Ark-Otte, J; Smit, E F; Postmus, P E; Giaccone, G

This report describes the validation of a polymerase chain reaction aided transcript titration assay (PATTY) for tumor samples. The results obtained with the PATTY were compared to those of RNase protection in a set of 7 human lung cancer cell lines and in 23 non-small cell lung cancer samples derived from resected patients. Whereas between PATTY and RNase protection assay a good correlation was observed in the cell lines (r = 0.74, p = 0.057), no correlation was observed within the tumor samples (r = 0.06, p = 0.78). This was also the case when only tumors with a high percentage of tumor cells (> 90%) were selected. Although PATTY is a valuable tool to measure mRNA expression in cell lines, our results caution the use of PATTY in human tumor samples without proper validation. The possible causes of these results are discussed.

Mechanical properties of silicate glasses exposed to a low-Earth orbit

NASA Technical Reports Server (NTRS)

Wiedlocher, David E.; Tucker, Dennis S.; Nichols, Ron; Kinser, Donald L.

1992-01-01

The effects of a 5.8 year exposure to low earth orbit environment upon the mechanical properties of commercial optical fused silica, low iron soda-lime-silica, Pyrex 7740, Vycor 7913, BK-7, and the glass ceramic Zerodur were examined. Mechanical testing employed the ASTM-F-394 piston on 3-ball method in a liquid nitrogen environment. Samples were exposed on the Long Duration Exposure Facility (LDEF) in two locations. Impacts were observed on all specimens except Vycor. Weibull analysis as well as a standard statistical evaluation were conducted. The Weibull analysis revealed no differences between control samples and the two exposed samples. We thus concluded that radiation components of the Earth orbital environment did not degrade the mechanical strength of the samples examined within the limits of experimental error. The upper bound of strength degradation for meteorite impacted samples based upon statistical analysis and observation was 50 percent.

Marital assortment for genetic similarity.

PubMed

Eckman, Ronael E; Williams, Robert; Nagoshi, Craig

2002-10-01

The present study involved analyses of a Caucasian American sample (n=949) and a Japanese American sample (n=400) for factors supporting Genetic Similarity Theory (GST). The analyses found no evidence for the presence of genetic similarity between spouses in either sample for the blood group analyses of nine loci. All results indicated random mating for blood group genes. The results did not provide consistent substantial support to show that spousal similarity is correlated with the degree of genetic component of a trait for a set of seventeen individual differences variables, with only the Caucasian sample yielding significant correlations for this analysis. A third analysis examining the correlation between presence of spousal genetic similarity and spousal similarity on observable traits was not performed because spousal genetic similarity was not observed in either sample. The overall implication of the study is that GST is not supported as an explanation for spousal similarity in humans.

Circulating tumoral cells lack circadian-rhythm in hospitalized metastasic breast cancer patients.

PubMed

García-Sáenz, José Angel; Martín, Miguel; Maestro, Marisa; Vidaurreta, Marta; Veganzones, Silvia; Villalobos, Laura; Rodríguez-Lajusticia, Laura; Rafael, Sara; Sanz-Casla, María Teresa; Casado, Antonio; Sastre, Javier; Arroyo, Manuel; Díaz-Rubio, Eduardo

2006-11-01

The relationship between breast cancer and circadian rhythm variation has been extensively studied. Increased breast tumorigenesis has been reported in melatonin-suppressed experimental models and in observational studies. Circulating Tumor Cells (CTC) circadian- rhythm may optimize the timing of therapies. This is a prospective experimental study to ascertain the day-time and night-time CTC levels in hospitalized metastasic breast cancer (MBC) patients. CTC are isolated and enumerated from a 08:00 AM and 08:00 PM blood collections. 23 MBC and 23 healthy volunteers entered the study. 69 samples were collected (23 samples at 08:00 AM and 23 samples at 08:00 PM from MBC; 23 samples from healthy volunteers). Results from two patients were rejected due to sample processing errors. No CTC were isolated from healthy-volunteers. No-differences between daytime and night-time CTC were observed. Therefore, we could not ascertain CTC circadian-rhythm in hospitalized metastasic breast cancer patients.

Role of aging time on the magnetic properties of Sm2Co17 permanent magnets processed through cold isostatic pressing

NASA Astrophysics Data System (ADS)

Ramudu, M.; Rajkumar, D. M.

2018-04-01

The effect of aging time on the magnetic properties of Sm2Co17 permanent magnets processed through a novel method of cold isostatic pressing was investigated. Sintered Sm2Co17 samples were subjected to different aging times in the range of 10-30 h and their respective microstructures were correlated with the magnetic properties obtained. The values of remanant magnetization (Br) were observed to be constant in samples aged from 10-20 h beyond which a gradual decrease in Br values was observed. The values of coercivity (Hc) displayed a sharp increase in samples aged from 10 to 20 h beyond which the coercivity values showed marginal improvement. Hence a good combination of magnetic properties could be achieved in samples aged for 20 h. A maximum energy product of 27 MGOe was achieved in the 20 h aged sample processed through a novel route.

Microstructure changes of on the extruded high-amylose bionanocomposites as affected by moisture content via synchrotron radiation studies

NASA Astrophysics Data System (ADS)

Liu, Huihua; Chaudhary, Deeptangshu

2014-08-01

The crystalline domain changes and lamellar structure observations of sorbitol-plasticized starch nanocomposite had been investigated via synchrotron. Strong interactions were found between amylose-sorbitol, resulting in reduced inter-helix spacing of the starch polymer. Achievable dspacing of nanoclay was confirmed to be correlated to the moisture content (mc) within the nanocomposites. SAXS diffraction patterns changed from circular (high mc samples) to elliptical (low mc samples), indicating the formation of long periodic structure and increased heterogeneities of the electron density within the samples. Two different domains sized at around 90 Å and 350 Å were found for the low mc samples. However, only the ~90 Å domain was observed in high mc samples. Formation of the 380 Å domain is attributed to the retrogradation behaviour in the absence of water molecules. Meanwhile, the nucleation effect of nanoclay is another factor leading to the emergence of the larger crystalline domain.

Comparison of direct observational methods for measuring stereotypic behavior in children with autism spectrum disorders.

PubMed

Gardenier, Nicole Ciotti; MacDonald, Rebecca; Green, Gina

2004-01-01

We compared partial-interval recording (PIR) and momentary time sampling (MTS) estimates against continuous measures of the actual durations of stereotypic behavior in young children with autism or pervasive developmental disorder-not otherwise specified. Twenty-two videotaped samples of stereotypy were scored using a low-tech duration recording method, and relative durations (i.e., proportions of observation periods consumed by stereotypy) were calculated. Then 10, 20, and 30s MTS and 10s PIR estimates of relative durations were derived from the raw duration data. Across all samples, PIR was found to grossly overestimate the relative duration of stereotypy. Momentary time sampling both over- and under-estimated the relative duration of stereotypy, but with much smaller errors than PIR (Experiment 1). These results were replicated across 27 samples of low, moderate and high levels of stereotypy (Experiment 2).

Lognormal kriging for the assessment of reliability in groundwater quality control observation networks

USGS Publications Warehouse

Candela, L.; Olea, R.A.; Custodio, E.

1988-01-01

Groundwater quality observation networks are examples of discontinuous sampling on variables presenting spatial continuity and highly skewed frequency distributions. Anywhere in the aquifer, lognormal kriging provides estimates of the variable being sampled and a standard error of the estimate. The average and the maximum standard error within the network can be used to dynamically improve the network sampling efficiency or find a design able to assure a given reliability level. The approach does not require the formulation of any physical model for the aquifer or any actual sampling of hypothetical configurations. A case study is presented using the network monitoring salty water intrusion into the Llobregat delta confined aquifer, Barcelona, Spain. The variable chloride concentration used to trace the intrusion exhibits sudden changes within short distances which make the standard error fairly invariable to changes in sampling pattern and to substantial fluctuations in the number of wells. ?? 1988.

Degradation of Coflon in Methanol at Temperatures Around 140 C

NASA Technical Reports Server (NTRS)

Campion, R. P.; Samulak, M.; Morgan, C. J.

1995-01-01

An unexpected and significant physico-chemical degradation of Coflon PVDF specimens was observed at the end of 1994 during routine scheduled exposure exercises on strained material. The intent was to age various samples, including some strained in a 4-point bend configuration, in methanol at 140 C and subsequently submit the aged samples to various tests including dynamic fatigue and fracture toughness. However, the samples deteriorated to such an extent that such testing was not possible: only when conditions were made less severe was it found possible to perform such testing. The purpose of the current report is to describe the nature of the PVDF deterioration observed during a number of tests performed to examine this phenomenon. This report also records, as Appendix 1, some SEM/X-ray microanalysis data on Coflon samples exposed to a methanol/amine mixture, and to other amine or H2S-aged samples.

A sampling design and model for estimating abundance of Nile crocodiles while accounting for heterogeneity of detectability of multiple observers

USGS Publications Warehouse

Shirley, Matthew H.; Dorazio, Robert M.; Abassery, Ekramy; Elhady, Amr A.; Mekki, Mohammed S.; Asran, Hosni H.

2012-01-01

As part of the development of a management program for Nile crocodiles in Lake Nasser, Egypt, we used a dependent double-observer sampling protocol with multiple observers to compute estimates of population size. To analyze the data, we developed a hierarchical model that allowed us to assess variation in detection probabilities among observers and survey dates, as well as account for variation in crocodile abundance among sites and habitats. We conducted surveys from July 2008-June 2009 in 15 areas of Lake Nasser that were representative of 3 main habitat categories. During these surveys, we sampled 1,086 km of lake shore wherein we detected 386 crocodiles. Analysis of the data revealed significant variability in both inter- and intra-observer detection probabilities. Our raw encounter rate was 0.355 crocodiles/km. When we accounted for observer effects and habitat, we estimated a surface population abundance of 2,581 (2,239-2,987, 95% credible intervals) crocodiles in Lake Nasser. Our results underscore the importance of well-trained, experienced monitoring personnel in order to decrease heterogeneity in intra-observer detection probability and to better detect changes in the population based on survey indices. This study will assist the Egyptian government establish a monitoring program as an integral part of future crocodile harvest activities in Lake Nasser

Emerging Methods and Systems for Observing Life in the Sea

NASA Astrophysics Data System (ADS)

Chavez, F.; Pearlman, J.; Simmons, S. E.

2016-12-01

There is a growing need for observations of life in the sea at time and space scales consistent with those made for physical and chemical parameters. International programs such as the Global Ocean Observing System (GOOS) and Marine Biodiversity Observation Networks (MBON) are making the case for expanded biological observations and working diligently to prioritize essential variables. Here we review past, present and emerging systems and methods for observing life in the sea from the perspective of maintaining continuous observations over long time periods. Methods that rely on ships with instrumentation and over-the-side sample collections will need to be supplemented and eventually replaced with those based from autonomous platforms. Ship-based optical and acoustic instruments are being reduced in size and power for deployment on moorings and autonomous vehicles. In parallel a new generation of low power, improved resolution sensors are being developed. Animal bio-logging is evolving with new, smaller and more sophisticated tags being developed. New genomic methods, capable of assessing multiple trophic levels from a single water sample, are emerging. Autonomous devices for genomic sample collection are being miniaturized and adapted to autonomous vehicles. The required processing schemes and methods for these emerging data collections are being developed in parallel with the instrumentation. An evolving challenge will be the integration of information from these disparate methods given that each provides their own unique view of life in the sea.

Quantifying ADHD classroom inattentiveness, its moderators, and variability: a meta-analytic review.

PubMed

Kofler, Michael J; Rapport, Mark D; Alderson, R Matt

2008-01-01

Most classroom observation studies have documented significant deficiencies in the classroom attention of children with attention-deficit/hyperactivity disorder (ADHD) compared to their typically developing peers. The magnitude of these differences, however, varies considerably and may be influenced by contextual, sampling, diagnostic, and observational differences. Meta-analysis of 23 between-group classroom observation studies using weighted regression, publication bias, goodness of fit, best case, and original metric analyses. Across studies, a large effect size (ES = .73) was found prior to consideration of potential moderators. Weighted regression, best case, and original metric estimation indicate that this effect may be an underestimation of the classroom visual attention deficits of children with ADHD. Several methodological factors-classroom environment, sample characteristics, diagnostic procedures, and observational coding schema-differentially affect observed rates of classroom attentive behavior for children with ADHD and typically developing children. After accounting for these factors, children with ADHD were on-task approximately 75% of the time compared to 88% for their classroom peers (ES = 1.40). Children with ADHD were also more variable in their attentive behavior across studies. The present study confirmed that children with ADHD exhibit deficient and more variable visual attending to required stimuli in classroom settings and provided an aggregate estimation of the magnitude of these deficits at the group level. It also demonstrated the impact of situational, sampling, diagnostic, and observational variables on observed rates of on-task behavior.

The research of the accuracy of asteroid orbit fitting using both radar and astrometric observations. (Russian Title: Исследование точности решения задачи улучшения орбит астероидов по данным их радарных и угловых наблюдений)

NASA Astrophysics Data System (ADS)

Baturin, A. P.; Kinzersky, V. V.

2014-12-01

The least-square orbit fitting problem for asteroids using their radar and astrometric observations has been considered. The both types of radar observations have been taken into account: the time delay observations and the Doppler observations. The research of accuracy increase due to the using of radar observations in addition to astrometric ones has been carried out. This research has been done by means of several orbit fittings using different samples of observations of some asteroids. The samples contain all radar observations and different numbers of astrometric ones. The orbit arc of radar observations of chosen asteroids is very short (several days) while the arcs of astrometric observations for all used samples are much longer. It has been demonstrated that the using of radar observations in the orbit fitting may increase the accuracy of obtained solution by 1-3 orders even in the cases of very long astromeric arcs (several years). During the research the convenient windows-interface for the calculating program has been developed. The functions of the program also have been expanded. Particularly, the ability of perturbations calculation from different planet ephemerides and of calculations with different machine precision have been added to the program.

Sampling strategies on Mars: Remote and not-so-remote observations from a surface rover

NASA Technical Reports Server (NTRS)

Singer, R. B.

1988-01-01

The mobility and speed of a semi-autonomous Mars rover are of necessity limited by the need to think and stay out of trouble. This consideration makes it essential that the rover's travels be carefully directed to likely targets of interest for sampling and in situ study. Short range remote sensing conducted from the rover, based on existing technology, can provide significant information about the chemistry and mineralogy of surrounding rocks and soils in support of sampling efforts. These observations are of course of direct scientific importance as well. Because of the small number of samples actually to be returned to Earth, it is also important that candidate samples be analyzed aboard the rover so that diversity can be maximized. It is essential to perform certain types of analyses, such as those involving volatiles, prior to the thermal and physical shocks of the return trip to Earth. In addition, whatever measurements can be made of nonreturned samples will be important to enlarge the context of the detailed analyses to be performed later on the few returned samples. Some considerations related to these objectives are discussed.

What Is the Shape of Developmental Change?

PubMed Central

Adolph, Karen E.; Robinson, Scott R.; Young, Jesse W.; Gill-Alvarez, Felix

2009-01-01

Developmental trajectories provide the empirical foundation for theories about change processes during development. However, the ability to distinguish among alternative trajectories depends on how frequently observations are sampled. This study used real behavioral data, with real patterns of variability, to examine the effects of sampling at different intervals on characterization of the underlying trajectory. Data were derived from a set of 32 infant motor skills indexed daily during the first 18 months. Larger sampling intervals (2-31 days) were simulated by systematically removing observations from the daily data and interpolating over the gaps. Infrequent sampling caused decreasing sensitivity to fluctuations in the daily data: Variable trajectories erroneously appeared as step-functions and estimates of onset ages were increasingly off target. Sensitivity to variation decreased as an inverse power function of sampling interval, resulting in severe degradation of the trajectory with intervals longer than 7 days. These findings suggest that sampling rates typically used by developmental researchers may be inadequate to accurately depict patterns of variability and the shape of developmental change. Inadequate sampling regimes therefore may seriously compromise theories of development. PMID:18729590

TANK 26F SUPERNATANT AND 2F EVAPORATOR EDUCTOR PUMP SAMPLE CHARACTERIZATION RESULTS

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

King, W.; Hay, M.; Coleman, C.

2011-08-23

In an effort to understand the reasons for system plugging problems in the SRS 2F evaporator, supernatant samples were retrieved from the evaporator feed tank (Tank 26F) and solids were collected from the evaporator eductor feed pump for characterization. The variable depth supernatant samples were retrieved from Tank 26F in early December of 2010 and samples were provided to SRNL and the F/H Area laboratories for analysis. Inspection and analysis of the samples at SRNL was initiated in early March of 2011. During the interim period, samples were frequently exposed to temperatures as low as 12 C with daily temperaturemore » fluctuations as high as 10 C. The temperature at the time of sample collection from the waste tank was 51 C. Upon opening the supernatant bottles at SRNL, many brown solids were observed in both of the Tank 26F supernatant samples. In contrast, no solids were observed in the supernatant samples sent to the F/H Area laboratories, where the analysis was completed within a few days after receipt. Based on these results, it is believed that the original Tank 26F supernatant samples did not contain solids, but solids formed during the interim period while samples were stored at ambient temperature in the SRNL shielded cells without direct climate control. Many insoluble solids (>11 wt. % for one sample) were observed in the Tank 26F supernatant samples after three months of storage at SRNL which would not dissolve in the supernatant solution in two days at 51 C. Characterization of these solids along with the eductor pump solids revealed the presence of sodium oxalate and clarkeite (uranyl oxyhydroxide) as major crystalline phases. Sodium nitrate was the dominant crystalline phase present in the unwashed Eductor Pump solids. Crystalline sodium nitrate may have formed during the drying of the solids after filtration or may have been formed in the Tank 26F supernatant during storage since the solution was found to be very concentrated (9-12 M Na{sup +}). Concentrated mineral acids and elevated temperature were required to dissolve all of these solids. The refractory nature of some of the solids is consistent with the presence of metal oxides such as aluminosilicates (observed as a minor phase by XRD). Characterization of the water wash solutions and the digested solids confirmed the presence of oxalate salts in both solid samples. Sulfate enrichment was also observed in the Tank 26F solids wash solution, indicating the presence of sulfate precipitates such as burkeite. OLI modeling of the Tank 26F filtered supernatant composition revealed that sodium oxalate has a very low solubility in this solution. The model predicts that the sodium oxalate solubility in the Tank 26F supernatant is only 0.0011 M at 50 C. The results indicate that the highly concentrated nature of the evaporator feed solution and the addition of oxalate anion to the waste stream each contribute to the formation of insoluble solids in the 2F evaporator system.« less

Looking around at the Zoo.

ERIC Educational Resources Information Center

Milson, James L.

1984-01-01

Suggests various observations that can be made while at a zoo, including behavior of animals, adaptations to special environments, locomotion, food type, and physical characteristics. Provides a sample data sheet for animal observations, citing the usefulness of organized observation. (JM)

The connection between the peaks in velocity dispersion and star-forming clumps of turbulent galaxies

NASA Astrophysics Data System (ADS)

Oliva-Altamirano, P.; Fisher, D. B.; Glazebrook, K.; Wisnioski, E.; Bekiaris, G.; Bassett, R.; Obreschkow, D.; Abraham, R.

2018-02-01

We present Keck/OSIRIS adaptive optics observations with 150-400 pc spatial sampling of 7 turbulent, clumpy disc galaxies from the DYNAMO sample ($0.07

Accelerating assimilation development for new observing systems using EFSO

NASA Astrophysics Data System (ADS)

Lien, Guo-Yuan; Hotta, Daisuke; Kalnay, Eugenia; Miyoshi, Takemasa; Chen, Tse-Chun

2018-03-01

To successfully assimilate data from a new observing system, it is necessary to develop appropriate data selection strategies, assimilating only the generally useful data. This development work is usually done by trial and error using observing system experiments (OSEs), which are very time and resource consuming. This study proposes a new, efficient methodology to accelerate the development using ensemble forecast sensitivity to observations (EFSO). First, non-cycled assimilation of the new observation data is conducted to compute EFSO diagnostics for each observation within a large sample. Second, the average EFSO conditionally sampled in terms of various factors is computed. Third, potential data selection criteria are designed based on the non-cycled EFSO statistics, and tested in cycled OSEs to verify the actual assimilation impact. The usefulness of this method is demonstrated with the assimilation of satellite precipitation data. It is shown that the EFSO-based method can efficiently suggest data selection criteria that significantly improve the assimilation results.

Using Lagrangian sampling to study water quality during downstream transport in the San Luis Drain, California, USA

USGS Publications Warehouse

Volkmar, E.C.; Dahlgren, R.A.; Stringfellow, W.T.; Henson, S.S.; Borglin, S.E.; Kendall, C.; Van Nieuwenhuyse, E. E.

2011-01-01

To investigate the mechanism for diel (24h) changes commonly observed at fixed sampling locations and how these diel changes relate to downstream transport in hypereutrophic surface waters, we studied a parcel of agricultural drainage water as it traveled for 84h in a concrete-lined channel having no additional water inputs or outputs. Algal fluorescence, dissolved oxygen, temperature, pH, conductivity, and turbidity were measured every 30min. Grab samples were collected every 2h for water quality analyses, including nutrients, suspended sediment, and chlorophyll/pheophytin. Strong diel patterns were observed for dissolved oxygen, pH, and temperature within the parcel of water. In contrast, algal pigments and nitrate did not exhibit diel patterns within the parcel of water, but did exhibit strong diel patterns for samples collected at a fixed sampling location. The diel patterns observed at fixed sampling locations for these constituents can be attributed to algal growth during the day and downstream transport (washout) of algae at night. Algal pigments showed a rapid daytime increase during the first 48h followed by a general decrease for the remainder of the study, possibly due to sedimentation and photobleaching. Algal growth (primarily diatoms) was apparent each day during the study, as measured by increasing dissolved oxygen concentrations, despite low phosphate concentrations (<0.01mgL-1). ?? 2011 Elsevier B.V.

Chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot after reactive gas probing using diffuse reflectance FTIR spectroscopy (DRIFTS).

PubMed

Tapia, A; Salgado, M S; Martín, M P; Rodríguez-Fernández, J; Rossi, M J; Cabañas, B

2017-03-01

A chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot has been developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) before and after the reaction with different probe gases. Samples were generated under combustion conditions corresponding to an urban operation mode of a diesel engine and were reacted with probe gas-phase molecules in a Knudsen flow reactor. Specifically, NH 2 OH, O 3 and NO 2 were used as reactants (probes) and selected according to their reactivities towards specific functional groups on the sample surface. Samples of previously ground soot were diluted with KBr and were introduced in a DRIFTS accessory. A comparison between unreacted and reacted soot samples was made in order to establish chemical changes on the soot surface upon reaction. It was concluded that the interface of diesel and HVO soot before reaction mainly consists polycyclic aromatic hydrocarbons, nitro and carbonyl compounds, as well as ether functionalities. The main difference between both soot samples was observed in the band of the C=O groups that in diesel soot was observed at 1719 cm -1 but not in HVO soot. After reaction with probe gases, it was found that nitro compounds remain on the soot surface, that the degree of unsaturation decreases for reacted samples, and that new spectral bands such as hydroxyl groups are observed.

A Quantitative Approach for Collocating NEON's Sensor-Based Ecological Measurements and in-situ Field Sampling and Observations

NASA Astrophysics Data System (ADS)

Zulueta, R. C.; Metzger, S.; Ayres, E.; Luo, H.; Meier, C. L.; Barnett, D.; Sanclements, M.; Elmendorf, S.

2013-12-01

The National Ecological Observatory Network (NEON) is a continental-scale research platform currently in development to assess the causes of ecological change and biological responses to change across a projected 30-year timeframe. A suite of standardized sensor-based measurements (i.e., Terrestrial Instrument System (TIS) measurements) and in-situ field sampling and observations (i.e., Terrestrial Observation System (TOS) activities) will be conducted across 20 ecoclimatic domains in the U.S. where NEON is establishing 60 terrestrial research sites. NEON's TIS measurements and TOS activities are designed to observe the temporal and spatial dynamics of key drivers and ecological processes and responses to change within each of the 60 terrestrial research sites. The TIS measurements are non-destructive and designed to provide in-situ, continuous, and areally integrated observations of the surrounding ecosystem and environment, while TOS sampling and observation activities are designed to encompass a hierarchy of measurable biological states and processes including diversity, abundance, phenology, demography, infectious disease prevalence, ecohydrology, and biogeochemistry. To establish valid relationships between these drivers and site-specific responses, two contradicting requirements must be fulfilled: (i) both types of observations shall be representative of the same ecosystem, and (ii) they shall not significantly influence one another. Here we outline the theoretical background and algorithmic process for determining areas of mutual representativeness and exclusion around NEON's TIS measurements and develop a procedure which quantitatively optimizes this trade-off through: (i) quantifying the source area distributions of TIS measurements, (ii) determining the ratio of user-defined impact threshold to effective impact area for different TOS activities, and (iii) determining the range of feasible distances between TIS locations and TOS activities. This approach provides an evidence-based and repeatable method for combining sensor-based measurements and field sampling and observations at predefined levels of disturbance and spatial representativeness. The developed approach represents a general framework which is applicable to other environmental research sites where similar collocation is desired.

A double-observer method for reducing bias in faecal pellet surveys of forest ungulates

USGS Publications Warehouse

Jenkins, K.J.; Manly, B.F.J.

2008-01-01

1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0.2-1.0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. ?? 2008 The Authors.

Process observation in fiber laser-based selective laser melting

NASA Astrophysics Data System (ADS)

Thombansen, Ulrich; Gatej, Alexander; Pereira, Milton

2015-01-01

The process observation in selective laser melting (SLM) focuses on observing the interaction point where the powder is processed. To provide process relevant information, signals have to be acquired that are resolved in both time and space. Especially in high-power SLM, where more than 1 kW of laser power is used, processing speeds of several meters per second are required for a high-quality processing results. Therefore, an implementation of a suitable process observation system has to acquire a large amount of spatially resolved data at low sampling speeds or it has to restrict the acquisition to a predefined area at a high sampling speed. In any case, it is vitally important to synchronously record the laser beam position and the acquired signal. This is a prerequisite that allows the recorded data become information. Today, most SLM systems employ f-theta lenses to focus the processing laser beam onto the powder bed. This report describes the drawbacks that result for process observation and suggests a variable retro-focus system which solves these issues. The beam quality of fiber lasers delivers the processing laser beam to the powder bed at relevant focus diameters, which is a key prerequisite for this solution to be viable. The optical train we present here couples the processing laser beam and the process observation coaxially, ensuring consistent alignment of interaction zone and observed area. With respect to signal processing, we have developed a solution that synchronously acquires signals from a pyrometer and the position of the laser beam by sampling the data with a field programmable gate array. The relevance of the acquired signals has been validated by the scanning of a sample filament. Experiments with grooved samples show a correlation between different powder thicknesses and the acquired signals at relevant processing parameters. This basic work takes a first step toward self-optimization of the manufacturing process in SLM. It enables the addition of cognitive functions to the manufacturing system to the extent that the system could track its own process. The results are based on analyzing and redesigning the optical train, in combination with a real-time signal acquisition system which provides a solution to certain technological barriers.

Design of a practical model-observer-based image quality assessment method for x-ray computed tomography imaging systems

PubMed Central

Tseng, Hsin-Wu; Fan, Jiahua; Kupinski, Matthew A.

2016-01-01

Abstract. The use of a channelization mechanism on model observers not only makes mimicking human visual behavior possible, but also reduces the amount of image data needed to estimate the model observer parameters. The channelized Hotelling observer (CHO) and channelized scanning linear observer (CSLO) have recently been used to assess CT image quality for detection tasks and combined detection/estimation tasks, respectively. Although the use of channels substantially reduces the amount of data required to compute image quality, the number of scans required for CT imaging is still not practical for routine use. It is our desire to further reduce the number of scans required to make CHO or CSLO an image quality tool for routine and frequent system validations and evaluations. This work explores different data-reduction schemes and designs an approach that requires only a few CT scans. Three different kinds of approaches are included in this study: a conventional CHO/CSLO technique with a large sample size, a conventional CHO/CSLO technique with fewer samples, and an approach that we will show requires fewer samples to mimic conventional performance with a large sample size. The mean value and standard deviation of areas under ROC/EROC curve were estimated using the well-validated shuffle approach. The results indicate that an 80% data reduction can be achieved without loss of accuracy. This substantial data reduction is a step toward a practical tool for routine-task-based QA/QC CT system assessment. PMID:27493982

The Detection and Statistics of Giant Arcs behind CLASH Clusters

NASA Astrophysics Data System (ADS)

Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Seitz, Stella; Zitrin, Adi; Merten, Julian; Maoz, Dani; Frye, Brenda; Umetsu, Keiichi; Zheng, Wei; Bradley, Larry; Vega, Jesus; Koekemoer, Anton

2016-02-01

We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ and length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift zs = 1.9 with 33% of the detected arcs having zs > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c-M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations.

Sparsely sampling the sky: a Bayesian experimental design approach

NASA Astrophysics Data System (ADS)

Paykari, P.; Jaffe, A. H.

2013-08-01

The next generation of galaxy surveys will observe millions of galaxies over large volumes of the Universe. These surveys are expensive both in time and cost, raising questions regarding the optimal investment of this time and money. In this work, we investigate criteria for selecting amongst observing strategies for constraining the galaxy power spectrum and a set of cosmological parameters. Depending on the parameters of interest, it may be more efficient to observe a larger, but sparsely sampled, area of sky instead of a smaller contiguous area. In this work, by making use of the principles of Bayesian experimental design, we will investigate the advantages and disadvantages of the sparse sampling of the sky and discuss the circumstances in which a sparse survey is indeed the most efficient strategy. For the Dark Energy Survey (DES), we find that by sparsely observing the same area in a smaller amount of time, we only increase the errors on the parameters by a maximum of 0.45 per cent. Conversely, investing the same amount of time as the original DES to observe a sparser but larger area of sky, we can in fact constrain the parameters with errors reduced by 28 per cent.

Testing the hierarchical assembly of massive galaxies using accurate merger rates out to z ˜ 1.5

NASA Astrophysics Data System (ADS)

Rodrigues, Myriam; Puech, M.; Flores, H.; Hammer, F.; Pirzkal, N.

2018-04-01

We established an accurate comparison between observationally and theoretically estimated major merger rates over a large range of mass (log Mbar/M⊙ =9.9-11.4) and redshift (z = 0.7-1.6). For this, we combined a new estimate of the merger rate from an exhaustive count of pairs within the virial radius of massive galaxies at z ˜ 1.265 and cross-validated with their morphology, with estimates from the morpho-kinematic analysis of two other samples. Theoretical predictions were estimated using semi-empirical models with inputs matching the properties of the observed samples, while specific visibility time-scales scaled to the observed samples were used. Both theory and observations are found to agree within 30 per cent of the observed value, which provides strong support to the hierarchical assembly of galaxies over the probed ranges of mass and redshift. Here, we find that ˜60 per cent of population of local massive (Mstellar =1010.3-11.6 M⊙) galaxies would have undergone a wet major merger since z = 1.5, consistently with previous studies. Such recent mergers are expected to result in the (re-)formation of a significant fraction of local disc galaxies.

Pulsed, atmospheric pressure plasma source for emission spectrometry

DOEpatents

Duan, Yixiang; Jin, Zhe; Su, Yongxuan

2004-05-11

A low-power, plasma source-based, portable molecular light emission generator/detector employing an atmospheric pressure pulsed-plasma for molecular fragmentation and excitation is described. The average power required for the operation of the plasma is between 0.02 W and 5 W. The features of the optical emission spectra obtained with the pulsed plasma source are significantly different from those obtained with direct current (dc) discharge higher power; for example, strong CH emission at 431.2 nm which is only weakly observed with dc plasma sources was observed, and the intense CN emission observed at 383-388 nm using dc plasma sources was weak in most cases. Strong CN emission was only observed using the present apparatus when compounds containing nitrogen, such as aniline were employed as samples. The present apparatus detects dimethylsulfoxide at 200 ppb using helium as the plasma gas by observing the emission band of the CH radical. When coupled with a gas chromatograph for separating components present in a sample to be analyzed, the present invention provides an apparatus for detecting the arrival of a particular component in the sample at the end of the chromatographic column and the identity thereof.

Representativeness-based sampling network design for the State of Alaska

Treesearch

Forrest M. Hoffman; Jitendra Kumar; Richard T. Mills; William W. Hargrove

2013-01-01

Resource and logistical constraints limit the frequency and extent of environmental observations, particularly in the Arctic, necessitating the development of a systematic sampling strategy to maximize coverage and objectively represent environmental variability at desired scales. A quantitative methodology for stratifying sampling domains, informing site selection,...

Work Sampling Study of an Engineering Professor during a Regular Contract Period

ERIC Educational Resources Information Center

Brink, Jan; McDonald, Dale B.

2015-01-01

Work sampling is a technique that has been employed in industry and fields such as healthcare for some time. It is a powerful technique, and an alternative to conventional stop watch time studies, used by industrial engineers to focus upon random work sampling observations. This study applies work sampling to the duties performed by an individual…

Instance-Based Learning: Integrating Sampling and Repeated Decisions from Experience

ERIC Educational Resources Information Center

Gonzalez, Cleotilde; Dutt, Varun

2011-01-01

In decisions from experience, there are 2 experimental paradigms: sampling and repeated-choice. In the sampling paradigm, participants sample between 2 options as many times as they want (i.e., the stopping point is variable), observe the outcome with no real consequences each time, and finally select 1 of the 2 options that cause them to earn or…

Reducing representativeness and sampling errors in radio occultation-radiosonde comparisons

NASA Astrophysics Data System (ADS)

Gilpin, Shay; Rieckh, Therese; Anthes, Richard

2018-05-01

Radio occultation (RO) and radiosonde (RS) comparisons provide a means of analyzing errors associated with both observational systems. Since RO and RS observations are not taken at the exact same time or location, temporal and spatial sampling errors resulting from atmospheric variability can be significant and inhibit error analysis of the observational systems. In addition, the vertical resolutions of RO and RS profiles vary and vertical representativeness errors may also affect the comparison. In RO-RS comparisons, RO observations are co-located with RS profiles within a fixed time window and distance, i.e. within 3-6 h and circles of radii ranging between 100 and 500 km. In this study, we first show that vertical filtering of RO and RS profiles to a common vertical resolution reduces representativeness errors. We then test two methods of reducing horizontal sampling errors during RO-RS comparisons: restricting co-location pairs to within ellipses oriented along the direction of wind flow rather than circles and applying a spatial-temporal sampling correction based on model data. Using data from 2011 to 2014, we compare RO and RS differences at four GCOS Reference Upper-Air Network (GRUAN) RS stations in different climatic locations, in which co-location pairs were constrained to a large circle ( ˜ 666 km radius), small circle ( ˜ 300 km radius), and ellipse parallel to the wind direction ( ˜ 666 km semi-major axis, ˜ 133 km semi-minor axis). We also apply a spatial-temporal sampling correction using European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim) gridded data. Restricting co-locations to within the ellipse reduces root mean square (RMS) refractivity, temperature, and water vapor pressure differences relative to RMS differences within the large circle and produces differences that are comparable to or less than the RMS differences within circles of similar area. Applying the sampling correction shows the most significant reduction in RMS differences, such that RMS differences are nearly identical to the sampling correction regardless of the geometric constraints. We conclude that implementing the spatial-temporal sampling correction using a reliable model will most effectively reduce sampling errors during RO-RS comparisons; however, if a reliable model is not available, restricting spatial comparisons to within an ellipse parallel to the wind flow will reduce sampling errors caused by horizontal atmospheric variability.

Molecular Epidemiology of Giardia, Blastocystis and Cryptosporidium among Indigenous Children from the Colombian Amazon Basin.

PubMed

Sánchez, Angie; Munoz, Marina; Gómez, Natalia; Tabares, Juan; Segura, Laura; Salazar, Ángela; Restrepo, Cristian; Ruíz, Miguel; Reyes, Patricia; Qian, Yuchen; Xiao, Lihua; López, Myriam C; Ramírez, Juan D

2017-01-01

The incidence and prevalence of intestinal parasites in children is most likely due to lack of natural or acquired resistance and differences in behavior and habits closely related to environmental and socioeconomic determinants. The most important protozoa that parasitize humans are Giardia, Entamoeba, Blastocystis , and Cryptosporidium . These parasites present wide intraspecific genetic diversity and subsequently classified into assemblages and subtypes. The Amazon basin is the largest in the world and is the fifth freshwater reserve on the planet. Contradictorily, people living in these areas (Indigenous populations) have poor quality of life, which favors the infection of diseases of fecal-oral transmission. The aim of this work was to unravel the molecular epidemiology of Giardia, Blastocystis and Cryptosporidium across four communities (Puerto Nariño, San Juan del Soco, Villa Andrea and Nuevo Paraíso). We obtained 284 fecal samples from children under 15 years old that were analyzed by direct microscopy (261 samples) and Real Time PCR (qPCR) (284 samples). The positive samples for these protozoa were further characterized by several molecular markers to depict assemblages and subtypes. We observed a frequency of Giardia infection by microscopy of 23.7% (62 samples) and by qPCR of 64.8% (184 samples); for Blastocystis by microscopy of 35.2% (92 samples) and by qPCR of 88.7% (252 samples) and for Cryptosporidium only 1.9% (5 samples) were positive by microscopy and qPCR 1.8% (5 samples). Regarding the Giardia assemblages, using the glutamate dehydrogenase ( gdh) marker we observed AI, BIII and BIV assemblages and when using triose phosphate isomerase ( tpi ) we observed assemblages AI, AII, BIII and BIV. In contrast, Blastocystis STs detected were 1, 2, 3, 4, and 6. Lastly, the species C. viatorum, C. hominis (with the subtypes IdA19 and IaA12R8) and C. parvum (with the subtype IIcA5G3c) were identified. We observed a high profile of zoonotic transmission regarding the Giardia assemblages and Blastocystis STs/alleles. Also, we highlight the elevated frequency of infection by these two protozoans suggesting an active transmission in the area. Our findings reinforces the need to deploy better epidemiological surveillance systems for enteric pathogens in the area.

Characterizing the fecal microbiota of infants with botulism.

PubMed

Shirey, T Brian; Dykes, Janet K; Lúquez, Carolina; Maslanka, Susan E; Raphael, Brian H

2015-11-23

Infant botulism is the most prevalent form of botulism in the USA, representing 68.5 % of cases reported from 2001-2012. Infant botulism results when botulinum toxin-producing clostridia (BTPC) colonize the infant gut with concomitant in vivo production of the highly potent botulinum neurotoxin (BoNT). The gut microbiota of infants with botulism is largely uncharacterized; therefore, it remains unclear whether the microbiota profile of these patients are distinct in composition, abundance, or diversity. To address this uncertainty, we employed 16S rRNA gene profiling to characterize the fecal microbiota in 14 stool samples among laboratory-confirmed and non-confirmed infant botulism cases. Seven bacterial phyla were identified among all 14 infant stool samples examined. Compared to samples from non-confirmed cases, the fecal microbiota of infant botulism patients displayed significantly higher Proteobacteria abundance. Of the 20 bacterial families identified, Enterobacteriaceae was significantly more abundant in samples from infants with botulism. Firmicutes abundance and the abundance ratio of Firmicutes/Proteobacteria was significantly lower in samples from infants with botulism. Lactobacillus spp. abundance was notably reduced in 12 of the 14 samples. Clostridium botulinum and Clostridium baratii were identified in low relative abundances in confirmed and non-confirmed samples based on their 16S rRNA gene profiles, although their toxigenicity remained undetermined. No significant differences were observed in the number of operational taxonomic units (OTUs) observed or in fecal microbiota diversity between laboratory-confirmed and non-confirmed samples. Correlations between individual phylum abundances and infant age were variable, and no significant differences were shown in number of OTUs observed or in fecal microbiota diversity between samples delineated by overall mean age. Significant differences in Proteobacteria, Firmicutes, and Enterobacteriaceae abundances were identified in the fecal microbiota of infants with botulism when compared to samples from non-confirmed cases. Fecal microbiota diversity was not significantly altered in infants with botulism, and a limited presence of BTPC was shown. It could not be determined whether the fecal microbiota profiles shown here were comparable prior to patient illness, or whether they were the direct result of infant botulism. The results of this study do, however, provide a detailed and descriptive observation into the infant gut microbiota after intestinal colonization by BTPC.

Soil Gas Sampling

EPA Pesticide Factsheets

Field Branches Quality System and Technical Procedures: This document describes general and specific procedures, methods and considerations to be used and observed when collecting soil gas samples for field screening or laboratory analysis.

Evaluation of NKX3.1 and C-MYC expression in canine prostatic cancer.

PubMed

Fonseca-Alves, Carlos Eduardo; Kobayashi, Priscila Emiko; Laufer-Amorim, Renée

2018-06-01

NKX3.1/C-MYC cross-regulation has been reported in the normal human prostate, and loss of NKX3.1 and gain of C-MYC seem to be important events in prostate cancer development and progression. The dog can be an interesting model for human prostatic disease, and yet only one previous research study has shown deregulation of NKX3.1 and MYC in the canine prostate. To address the expression of NKX3.1 and C-MYC in different canine prostatic lesions, this study verified the gene and protein expression of NKX3.1 and C-MYC in normal canine prostatic tissues. We identified a 26 kDa band that corresponded to the NKX3.1 protein, while C-MYC showed a 50 kDa band on Western blotting analysis of all prostatic tissues. We observed that NKX3.1 protein and transcript were down-regulated in prostate cancer (PC) samples compared with non-neoplastic samples. We also observed that C-MYC protein was overexpressed in PC samples compared with normal (P = .001) and proliferative inflammatory atrophy (PIA) samples (P = .003). We found a positive correlation between NKX3.1 and C-MYC protein expression in normal and PIA samples. Interestingly, a negative correlation (NKX3.1 downregulation and MYC overexpression) was observed between NKX3.1 and MYC transcripts in PC. Thus, samples with higher C-MYC expression also exhibited higher NKX3.1 expression, which indicates the regulation of C-MYC by NKX3.1 protein. As in humans, these two genes and proteins were found to be related to canine prostate cancer. However, in contrast from what is observed in humans, in canine PC samples, the downregulation of NKX3.1 cannot be explained by DNA hypermethylation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Visual sensitivity to spatially sampled modulation in human observers

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.; Macleod, Donald I. A.

1991-01-01

Thresholds were measured for detecting spatial luminance modulation in regular lattices of visually discrete dots. Thresholds for modulation of a lattice are generally higher than the corresponding threshold for modulation of a continuous field, and the size of the threshold elevation, which depends on the spacing of the lattice elements, can be as large as a one log unit. The largest threshold elevations are seen when the sample spacing is 12 min arc or greater. Theories based on response compression cannot explain the further observation that the threshold elevations due to spatial sampling are also dependent on modulation frequency: the greatest elevations occur with higher modulation frequencies. The idea that this is due to masking of the modulation frequency by the spatial frequencies in the sampling lattice is considered.

Proximity-induced superconductivity within the InAs/GaSb edge conducting state

NASA Astrophysics Data System (ADS)

Kononov, A.; Kostarev, V. A.; Semyagin, B. R.; Preobrazhenskii, V. V.; Putyato, M. A.; Emelyanov, E. A.; Deviatov, E. V.

2017-12-01

We experimentally investigate Andreev transport through the interface between an indium superconductor and the edge of the InAs/GaSb bilayer. To cover all possible regimes of the InAs/GaSb spectrum, we study samples with 10-nm-, 12-nm-, and 14-nm-thick InAs quantum wells. For the trivial case of a direct band insulator in 10 nm samples, differential resistance demonstrates standard Andreev reflection. For InAs/GaSb structures with band inversion (12 and 14 nm samples), we observe distinct low-energy structures, which we regard as direct evidence for the proximity-induced superconductivity within the current-carrying edge state. For 14 nm InAs well samples, we additionally observe mesoscopiclike resistance fluctuations, which are subjected to threshold suppression in low magnetic fields.

Observation of amorphous to crystalline phase transformation in Te substituted Sn-Sb-Se thin films

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

Chander, Ravi, E-mail: rcohri@yahoo.com

2015-05-15

Thin films of Sn-Sb-Se-Te (8 ≤ x ≤ 14) chalcogenide system were prepared by thermal evaporation technique using melt quenched bulk samples. The as-prepared thin films were found amorphous as evidenced from X-ray diffraction studies. Resistivity measurement showed an exponential decrease with temperature upto critical temperature (transition temperature) beyond which a sharp decrease was observed and with further increase in temperature showed an exponential decrease in resistivity with different activation energy. The transition temperature showed a decreasing trend with tellurium content in the sample. The resistivity measurement during cooling run showed no abrupt change in resistivity. The resistivity measurements ofmore » annealed films did not show any abrupt change revealing the structural transformation occurring in the material. The transition width showed an increase with tellurium content in the sample. The resistivity ratio showed two order of magnitude improvements for sample with higher tellurium content. The observed transition temperature in this system was found quite less than already commercialized Ge-Sb-Te system for optical and electronic memories.« less

The Benefits of Sample Return: Connecting Apollo Soils and Diviner Lunar Radiometer Remote Sensing Data

NASA Technical Reports Server (NTRS)

Greenhagen, B. T.; Donaldson-Hanna, K. L.; Thomas, I. R.; Bowles, N. E.; Allen, C. C.; Pieters, C. M.; Paige, D. A.

2014-01-01

The Diviner Lunar Radiometer, onboard NASA's Lunar Reconnaissance Orbiter, has produced the first global, high resolution, thermal infrared observations of an airless body. The Moon, which is the most accessible member of this most abundant class of solar system objects, is also the only body for which we have extraterrestrial samples with known spatial context. Here we present the results of a comprehensive study to reproduce an accurate simulated lunar environment, evaluate the most appropriate sample and measurement conditions, collect thermal infrared spectra of a representative suite of Apollo soils, and correlate them with Diviner observations of the lunar surface. We find that analyses of Diviner observations of individual sampling stations and SLE measurements of returned Apollo soils show good agreement, while comparisons to thermal infrared reflectance under terrestrial conditions do not agree well, which underscores the need for SLE measurements and validates the Diviner compositional dataset. Future work includes measurement of additional soils in SLE and cross comparisons with measurements in JPL Simulated Airless Body Emission Laboratory (SABEL).

Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope.

PubMed

Neděla, Vilém; Hřib, Jiří; Havel, Ladislav; Hudec, Jiří; Runštuk, Jiří

2016-05-01

This article describes the surface structure of Norway spruce early somatic embryos (ESEs) as a typical culture with asynchronous development. The microstructure of extracellular matrix covering ESEs were observed using the environmental scanning electron microscope as a primary tool and using the scanning electron microscope with cryo attachment and laser electron microscope as a complementary tool allowing our results to be proven independently. The fresh samples were observed in conditions of the air environment of the environmental scanning electron microscope (ESEM) with the pressure from 550Pa to 690Pa and the low temperature of the sample from -18°C to -22°C. The samples were studied using two different types of detector to allow studying either the thin surface structure or material composition. The scanning electron microscope with cryo attachment was used for imaging frozen extracellular matrix microstructure with higher resolution. The combination of both electron microscopy methods was suitable for observation of "native" plant samples, allowing correct evaluation of our results, free of error and artifacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Band gap and conductivity variations of ZnO nano structured thin films annealed under Vacuum

NASA Astrophysics Data System (ADS)

Vattappalam, Sunil C.; Thomas, Deepu; T, Raju Mathew; Augustine, Simon; Mathew, Sunny

2015-02-01

Zinc Oxide thin films were prepared by Successive Ionic layer adsorption and reaction technique(SILAR). The samples were annealed under vacuum and conductivity of the samples were taken at different temperatures. UV Spectrograph of the samples were taken and the band gap of each sample was found from the data. All the results were compared with that of the sample annealed under air. It was observed that the band gap decreases and concequently conductivity of the samples increases when the samples are annealed under vacuum.

Sample holder with optical features

DOEpatents

Milas, Mirko; Zhu, Yimei; Rameau, Jonathan David

2013-07-30

A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

Transmission electron microscope sample holder with optical features

DOEpatents

Milas, Mirko [Port Jefferson, NY; Zhu, Yimei [Stony Brook, NY; Rameau, Jonathan David [Coram, NY

2012-03-27

A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

Seaborg's plutonium? A case study in nuclear forensics

DOE PAGES

Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

2015-10-01

Passive X-ray and gamma-ray analysis was performed on a curious sample from UC Berkeley's Hazardous Material Facility inventory, and the object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 ± 0.3 μg. These observations are consistent with the identification of this object as containing the 2.77-μg PuO2 (2.44 μg 239Pu) sample produced in 1942 and described by Seaborg and his collaborators as the first sample of 239Pu that was large enough to be weighed.

Bias-induced conformational switching of supramolecular networks of trimesic acid at the solid-liquid interface

NASA Astrophysics Data System (ADS)

Ubink, J.; Enache, M.; Stöhr, M.

2018-05-01

Using the tip of a scanning tunneling microscope, an electric field-induced reversible phase transition between two planar porous structures ("chickenwire" and "flower") of trimesic acid was accomplished at the nonanoic acid/highly oriented pyrolytic graphite interface. The chickenwire structure was exclusively observed for negative sample bias, while for positive sample bias only the more densely packed flower structure was found. We suggest that the slightly negatively charged carboxyl groups of the trimesic acid molecule are the determining factor for this observation: their adsorption behavior varies with the sample bias and is thus responsible for the switching behavior.

Observation of ferromagnetism in Mn doped KNbO3

NASA Astrophysics Data System (ADS)

Manikandan, M.; Venkateswaran, C.

2015-06-01

Pure and Mn doped KNbO3 have been prepared by ball milling assisted ceramic method. Mn ion had been doped at Nb site to induce ferromagnetism at room temperature. X-ray diffraction (XRD) patterns reveal the formation of orthorhombic phase. High resolution scanning electron micrograph (HR-SEM) of both pure and Mn doped samples show a mixture of spherical and plate like particles. Room temperature magnetic behavior of both the samples were analyzed using vibrating sample magnetometer (VSM). 5% Mn doped KNbO3 exhibits ferromagnetic behavior. Observed ferromagnetic feature has been explained by interactions between bound magnetic polarons which are created by Mn4+ ions.

Proportionality between Doppler noise and integrated signal path electron density validated by differenced S-X range

NASA Technical Reports Server (NTRS)

Berman, A. L.

1977-01-01

Observations of Viking differenced S-band/X-band (S-X) range are shown to correlate strongly with Viking Doppler noise. A ratio of proportionality between downlink S-band plasma-induced range error and two-way Doppler noise is calculated. A new parameter (similar to the parameter epsilon which defines the ratio of local electron density fluctuations to mean electron density) is defined as a function of observed data sample interval (Tau) where the time-scale of the observations is 15 Tau. This parameter is interpreted to yield the ratio of net observed phase (or electron density) fluctuations to integrated electron density (in RMS meters/meter). Using this parameter and the thin phase-changing screen approximation, a value for the scale size L is calculated. To be consistent with Doppler noise observations, it is seen necessary for L to be proportional to closest approach distance a, and a strong function of the observed data sample interval, and hence the time-scale of the observations.

Reviews and syntheses: guiding the evolution of the observing system for the carbon cycle through quantitative network design

NASA Astrophysics Data System (ADS)

Kaminski, Thomas; Rayner, Peter Julian

2017-10-01

Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. These observations have the potential to reduce uncertainties in past, current, and predicted natural and anthropogenic surface fluxes. In particular such observations provide independent information for verification of actions as requested by the Paris Agreement. It is, however, difficult to decide which variables to sample, and how, where, and when to sample them, in order to achieve an optimal use of the observational capabilities. Quantitative network design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit to be expected from planned space missions. This paper describes recent progress and highlights aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy.

Standard Deviation for Small Samples

ERIC Educational Resources Information Center

Joarder, Anwar H.; Latif, Raja M.

2006-01-01

Neater representations for variance are given for small sample sizes, especially for 3 and 4. With these representations, variance can be calculated without a calculator if sample sizes are small and observations are integers, and an upper bound for the standard deviation is immediate. Accessible proofs of lower and upper bounds are presented for…

Intense Terahertz Fields for Fast Energy Release

DTIC Science & Technology

2016-11-01

could allow us to monitor shock propagation in the sample and observe any effects of THz irradiation . In order to optimize the system, we moved a...the response and access for the THz light needed to simultaneously irradiate the sample. Preliminary measurements of sample responses to each of the

Spectral Characterization of H2020/PTAL Mineral Samples: Implications for In Situ Martian Exploration and Mars Sample Selection

NASA Astrophysics Data System (ADS)

Lantz, C.; Pilorget, C.; Poulet, F.; Riu, L.; Dypvik, H.; Hellevang, H.; Rull Perez, F.; Veneranda, M.; Cousin, A.; Viennet, J.-C.; Werner, S. C.

2018-04-01

We present combined analysis performed in the framework of the Planetary Terrestrial Analogues Library (H2020 project). XRD, NIR, Raman, and LIBS spectroscopies are used to characterise samples to prepare ExoMars/ESA and Mars2020/NASA observations.

Multiple Category-Lot Quality Assurance Sampling: A New Classification System with Application to Schistosomiasis Control

PubMed Central

Olives, Casey; Valadez, Joseph J.; Brooker, Simon J.; Pagano, Marcello

2012-01-01

Background Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS) have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa. Methodology We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n = 15 and n = 25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa. Principle Findings Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87). In three of the studies, the kappa-statistic for a design with n = 15 was greater than 0.75. In the fourth study, where these designs performed poorly (kappa-statistic less than 0.50), the majority of observations fell in regions where potential error is known to be high. Employment of semi-curtailed and curtailed sampling further reduced the sample size by as many as 0.5 and 3.5 observations per school, respectively, without increasing classification error. Conclusion/Significance This work provides the needed analytics to understand the properties of MC-LQAS for assessing the prevalance of S. mansoni and shows that in most settings a sample size of 15 children provides a reliable classification of schools. PMID:22970333

Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota

NASA Astrophysics Data System (ADS)

Marteinsson, V.; Klonowski, A.; Reynisson, E.; Vannier, P.; Sigurdsson, B. D.; Ólafsson, M.

2015-02-01

Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associated vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soil types on the surface of the island. Total viable bacterial counts were performed with the plate count method at 22, 30 and 37 °C for all soil samples, and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms and aerobic and anaerobic bacteria. The subsurface biosphere was investigated by collecting liquid subsurface samples from a 181 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between nutrient deficits and the number of microorganisms in surface soil samples. The lowest number of bacteria (1 × 104-1 × 105 cells g-1) was detected in almost pure pumice but the count was significantly higher (1 × 106-1 × 109 cells g-1) in vegetated soil or pumice with bird droppings. The number of faecal bacteria correlated also to the total number of bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in vegetated samples and samples containing bird droppings. The human pathogens Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S rDNA sequences were found in the subsurface samples collected at 145 and 172 m depth at 80 and 54 °C, respectively, but no growth was observed in enrichments. The microbiota sequences generally showed low affiliation to any known 16S rRNA gene sequences.

Methodological integrative review of the work sampling technique used in nursing workload research.

PubMed

Blay, Nicole; Duffield, Christine M; Gallagher, Robyn; Roche, Michael

2014-11-01

To critically review the work sampling technique used in nursing workload research. Work sampling is a technique frequently used by researchers and managers to explore and measure nursing activities. However, work sampling methods used are diverse making comparisons of results between studies difficult. Methodological integrative review. Four electronic databases were systematically searched for peer-reviewed articles published between 2002-2012. Manual scanning of reference lists and Rich Site Summary feeds from contemporary nursing journals were other sources of data. Articles published in the English language between 2002-2012 reporting on research which used work sampling to examine nursing workload. Eighteen articles were reviewed. The review identified that the work sampling technique lacks a standardized approach, which may have an impact on the sharing or comparison of results. Specific areas needing a shared understanding included the training of observers and subjects who self-report, standardization of the techniques used to assess observer inter-rater reliability, sampling methods and reporting of outcomes. Work sampling is a technique that can be used to explore the many facets of nursing work. Standardized reporting measures would enable greater comparison between studies and contribute to knowledge more effectively. Author suggestions for the reporting of results may act as guidelines for researchers considering work sampling as a research method. © 2014 John Wiley & Sons Ltd.

Mycobacterial infections in striped bass from Delaware Bay

USGS Publications Warehouse

Ottinger, C.A.; Brown, J.J.; Densmore, Christine L.; Starliper, C.E.; Blazer, V.S.; Weyers, H.S.; Beauchamp, K.A.; Rhodes, M.W.; Kator, H.; Gauthier, David T.; Vogelbein, W.K.

2007-01-01

Eighty striped bass Morone saxatilis were obtained from Delaware Bay using commercial gill nets set adjacent to Woodland Beach (n = 70) and Bowers Beach (n = 10) in December 2003. Fish were examined for gross lesions. Total lengths (TLs) and eviscerated weights were determined to calculate condition factors (K). Portions of spleens were aseptically harvested for bacterial culture, and portions of spleens, kidneys (anterior and posterior), livers, and gonads were obtained for histological examination. The size distribution of the striped bass was relatively homogeneous; the mean TL was about 600 mm for all samples. Mean K exceeded 0.95 in all samples and was not significantly different (P > 0.05) among samples. Significant differences in mycobacterial infection prevalence (P ??? 0.05) were observed among samples; samples obtained at Woodland Beach (WB) on December 10 (53.8%, n = 13) and December 17 (7.1%, n = 42) exhibited the most striking differences in prevalence. Mycobacterial infection intensity ranged from 1 ?? 102 to 1 ?? 107 colony-forming units per gram of spleen. Acanthocephalan infection prevalence and intensity, non-acid-fast bacterial infection prevalence, and fish sex ratio were also significantly different among the samples (P ??? 0.05). Similar to the mycobacterial infections, differences in sex ratio, acanthocephalan infection, and non-acid-fast bacterial infection were observed between the WB samples taken on December 10 and 17. However, no significant associations (P > 0.05) were observed between sex ratio or these infections and mycobacterial infection. The differences in bacterial and parasite infection prevalence and intensity and fish sex ratio in some samples indicate that these fish had a different history and that the epizootiology of mycobacterial infection in striped bass from Delaware Bay may be relatively complex. ?? Copyright by the American Fisheries Society 2007.

Impact of the New Abbott mPLUS Feature on Clinical Laboratory Efficiencies of Abbott RealTime Assays for Detection of HIV-1, Hepatitis C Virus, Hepatitis B Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae

PubMed Central

Jones, Sara; Wiesneth, Russ; Barry, Cathy; Webb, Erika; Belova, Larissa; Dolan, Peggy; Ho, Shiaolan; Abravaya, Klara; Cloherty, Gavin

2013-01-01

Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents. PMID:24088850

Impact of the New Abbott mPLUS feature on clinical laboratory efficiencies of abbott RealTime assays for detection of HIV-1, Hepatitis C Virus, Hepatitis B Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae.

PubMed

Lucic, Danijela; Jones, Sara; Wiesneth, Russ; Barry, Cathy; Webb, Erika; Belova, Larissa; Dolan, Peggy; Ho, Shiaolan; Abravaya, Klara; Cloherty, Gavin

2013-12-01

Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents.

Mycobacterial infections in striped bass from Delaware Bay.

PubMed

Ottinger, C A; Brown, J J; Densmore, C L; Starliper, C E; Blazer, V S; Weyers, H S; Beauchamp, K A; Rhodes, M W; Kator, H; Gauthier, D T; Vogelbein, W K

2007-06-01

Eighty striped bass Morone saxatilis were obtained from Delaware Bay using commercial gill nets set adjacent to Woodland Beach (n = 70) and Bowers Beach (n = 10) in December 2003. Fish were examined for gross lesions. Total lengths (TLs) and eviscerated weights were determined to calculate condition factors (K). Portions of spleens were aseptically harvested for bacterial culture, and portions of spleens, kidneys (anterior and posterior), livers, and gonads were obtained for histological examination. The size distribution of the striped bass was relatively homogeneous; the mean TL was about 600 mm for all samples. Mean K exceeded 0.95 in all samples and was not significantly different (P > 0.05) among samples. Significant differences in mycobacterial infection prevalence (P < or = 0.05) were observed among samples; samples obtained at Woodland Beach (WB) on December 10 (53.8%, n = 13) and December 17 (7.1%, n = 42) exhibited the most striking differences in prevalence. Mycobacterial infection intensity ranged from 1 X 10(2) to 1 X 10(7) colony-forming units per gram of spleen. Acanthocephalan infection prevalence and intensity, non-acid-fast bacterial infection prevalence, and fish sex ratio were also significantly different among the samples (P < or = 0.05). Similar to the mycobacterial infections, differences in sex ratio, acanthocephalan infection, and non-acid-fast bacterial infection were observed between the WB samples taken on December 10 and 17. However, no significant associations (P > 0.05) were observed between sex ratio or these infections and mycobacterial infection. The differences in bacterial and parasite infection prevalence and intensity and fish sex ratio in some samples indicate that these fish had a different history and that the epizootiology of mycobacterial infection in striped bass from Delaware Bay may be relatively complex.

Effect on the grain size of single-mode microwave sintered NiCuZn ferrite and zinc titanate dielectric resonator ceramics.

PubMed

Sirugudu, Roopas Kiran; Vemuri, Rama Krishna Murthy; Venkatachalam, Subramanian; Gopalakrishnan, Anisha; Budaraju, Srinivasa Murty

2011-01-01

Microwave sintering of materials significantly depends on dielectric, magnetic and conductive Losses. Samples with high dielectric and magnetic loss such as ferrites could be sintered easily. But low dielectric loss material such as dielectric resonators (paraelectrics) finds difficulty in generation of heat during microwave interaction. Microwave sintering of materials of these two classes helps in understanding the variation in dielectric and magnetic characteristics with respect to the change in grain size. High-energy ball milled Ni0.6Cu0.2Zn0.2Fe1.98O4-delta and ZnTiO3 are sintered in conventional and microwave methods and characterized for respective dielectric and magnetic characteristics. The grain size variation with higher copper content is also observed with conventional and microwave sintering. The grain size in microwave sintered Ni0.6Cu0.2Zn0.2Fe1.98O4-delta is found to be much small and uniform in comparison with conventional sintered sample. However, the grain size of microwave sintered sample is almost equal to that of conventional sintered sample of Ni0.3Cu0.5Zn0.2Fe1.98O4-delta. In contrast to these high dielectric and magnetic loss ferrites, the paraelectric materials are observed to sinter in presence of microwaves. Although microwave sintered zinc titanate sample showed finer and uniform grains with respect to conventional samples, the dielectric characteristics of microwave sintered sample are found to be less than that of conventional sample. Low dielectric constant is attributed to the low density. Smaller grain size is found to be responsible for low quality factor and the presence of small percentage of TiO2 is observed to achieve the temperature stable resonant frequency.

Evaluation of expression and function of vascular endothelial growth factor receptor 2, platelet derived growth factor receptors-alpha and -beta, KIT, and RET in canine apocrine gland anal sac adenocarcinoma and thyroid carcinoma.

PubMed

Urie, Bridget K; Russell, Duncan S; Kisseberth, William C; London, Cheryl A

2012-05-25

Toceranib phosphate (Palladia) has a reported objective response rate of 25% in both canine apocrine gland anal sac adenocarcinoma (AGASACA) and thyroid carcinoma (TC), with stable disease occurring in an additional 50-60% of dogs. The basis for the observed responses to toceranib is not known. The purpose of this study was to evaluate AGASACA and TC samples for the expression and activation of VEGFR2, PDGFRα, PDGFRβ, KIT and RET to assess whether dysregulation of these receptor tyrosine kinases (RTKs) may contribute to the biologic activity of toceranib. mRNA for VEGFR2, PDGFRα/β, KIT and RET was detected in all AGASACA samples. mRNA for VEGFR2, PDGFRα/β, and KIT was detected in all TC samples, while mRNA for RET was amplified in 10/15 samples. No phosphorylation of VEGFR2, PDGFRα/β, or KIT was observed on the arrays. However, phosphorylation of RET was detected in 54% of the primary AGASACA and 20% of TC. VEGFR2 was expressed in 19/24 primary and 6/10 metastatic AGASACA and 6/15 TC samples. KIT was present in 8/24 primary and 3/10 metastatic AGASACA and 9/15 TC samples. PDGFRα expression was noted in all tumor samples. In contrast PDGFRβ expression was found in only a few tumor samples but was evident in the stroma of all tumor specimens. Known targets of toceranib are expressed in both AGASAC and TC. Given the observed expression of VEGFR and PDGFRα/β and phosphorylation of RET, these RTKs merit investigation as to their roles in the biology of AGSACA and TC and their contribution to toceranib's activity.

Evaluation of expression and function of vascular endothelial growth factor receptor 2, platelet derived growth factor receptors-alpha and -beta, KIT, and RET in canine apocrine gland anal sac adenocarcinoma and thyroid carcinoma

PubMed Central

2012-01-01

Background Toceranib phosphate (Palladia) has a reported objective response rate of 25% in both canine apocrine gland anal sac adenocarcinoma (AGASACA) and thyroid carcinoma (TC), with stable disease occurring in an additional 50-60% of dogs. The basis for the observed responses to toceranib is not known. The purpose of this study was to evaluate AGASACA and TC samples for the expression and activation of VEGFR2, PDGFRα, PDGFRβ, KIT and RET to assess whether dysregulation of these receptor tyrosine kinases (RTKs) may contribute to the biologic activity of toceranib. Results mRNA for VEGFR2, PDGFRα/β, KIT and RET was detected in all AGASACA samples. mRNA for VEGFR2, PDGFRα/β, and KIT was detected in all TC samples, while mRNA for RET was amplified in 10/15 samples. No phosphorylation of VEGFR2, PDGFRα/β, or KIT was observed on the arrays. However, phosphorylation of RET was detected in 54% of the primary AGASACA and 20% of TC. VEGFR2 was expressed in 19/24 primary and 6/10 metastatic AGASACA and 6/15 TC samples. KIT was present in 8/24 primary and 3/10 metastatic AGASACA and 9/15 TC samples. PDGFRα expression was noted in all tumor samples. In contrast PDGFRβ expression was found in only a few tumor samples but was evident in the stroma of all tumor specimens. Conclusions Known targets of toceranib are expressed in both AGASAC and TC. Given the observed expression of VEGFR and PDGFRα/β and phosphorylation of RET, these RTKs merit investigation as to their roles in the biology of AGSACA and TC and their contribution to toceranib’s activity. PMID:22630170

Superficial and deep changes of histology, texture and particle size distribution in broiler wooden breast muscle during refrigerated storage.

PubMed

Soglia, Francesca; Gao, Jingxian; Mazzoni, Maurizio; Puolanne, Eero; Cavani, Claudio; Petracci, Massimiliano; Ertbjerg, Per

2017-09-01

Recently the poultry industry faced an emerging muscle abnormality termed wooden breast (WB), the prevalence of which has dramatically increased in the past few years. Considering the incomplete knowledge concerning this condition and the lack of information on possible variations due to the intra-fillet sampling locations (superficial vs. deep position) and aging of the samples, this study aimed at investigating the effect of 7-d storage of broiler breast muscles on histology, texture, and particle size distribution, evaluating whether the sampling position exerts a relevant role in determining the main features of WB. With regard to the histological observations, severe myodegeneration accompanied by accumulation of connective tissue was observed within the WB cases, irrespective of the intra-fillet sampling position. No changes in the histological traits took place during the aging in either the normal or the WB samples. As to textural traits, although a progressive tenderization process took place during storage (P ≤ 0.001), the differences among the groups were mainly detected when raw meat rather than cooked was analyzed, with the WB samples exhibiting the highest (P ≤ 0.001) 80% compression values. In spite of the increased amount of connective tissue components in the WB cases, their thermally labile cross-links will account for the similar compression and shear-force values as normal breast cases when measured on cooked samples. Similarly, the enlargement of extracellular matrix and fibrosis might contribute in explaining the different fragmentation patterns observed between the superficial and the deep layer in the WB samples, with the superficial part exhibiting a higher amount of larger particles and an increase in particles with larger size during storage, compared to normal breasts. © 2017 Poultry Science Association Inc.

Seasonal fluctuations of organophosphate concentrations in precipitation and storm water runoff.

PubMed

Regnery, Julia; Püttmann, Wilhelm

2010-02-01

To investigate seasonal fluctuations and trends of organophosphate (flame retardants, plasticizers) concentrations in rain and snow, precipitation samples were collected in 2007-2009 period at a densely populated urban sampling site and two sparsely populated rural sampling sites in middle Germany. In addition, storm water runoff was sampled from May 2008 to April 2009 at an urban storm water holding tank (SWHT). Samples were analyzed for tris(2-chloroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCP), tris(2-butoxyethyl) phosphate (TBEP), tri-iso-butyl phosphate (TiBP), and tri-n-butyl phosphate (TnBP) by gas chromatography-mass spectrometry after solid phase extraction. Among the six analyzed organophosphates (OPs), TCPP dominated in all precipitation and SWHT water samples with maximum concentrations exceeding 1000ngL(-1). For all analytes, no seasonal trends were observed at the urban precipitation sampling site, although atmospheric photooxidation was expected to reduce particularly concentrations of non-chlorinated OPs during transport from urban to remote areas in summer months with higher global irradiation. In the SWHT a seasonal trend with decreasing concentrations in summer/autumn is evident for the non-chlorinated OPs due to in-lake degradation but not for the chlorinated OPs. Furthermore, an accumulation of OPs deposited in SWHTs was observed with concentrations often exceeding those observed in wet precipitation. Median concentrations of TCPP (880ngL(-1)), TDCP (13ngL(-1)) and TBEP (77ngL(-1)) at the SWHT were more than twice as high as median concentrations measured at the urban precipitation sampling site (403ngL(-1), 5ngL(-1), and 21ngL(-1) respectively).

The Added Value of the Combined Use of the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule: Diagnostic Validity in a Clinical Swedish Sample of Toddlers and Young Preschoolers

ERIC Educational Resources Information Center

Zander, Eric; Sturm, Harald; Bölte, Sven

2015-01-01

The diagnostic validity of the new research algorithms of the Autism Diagnostic Interview-Revised and the revised algorithms of the Autism Diagnostic Observation Schedule was examined in a clinical sample of children aged 18-47 months. Validity was determined for each instrument separately and their combination against a clinical consensus…

In Silico Genome Mismatch Scanning to Map Breast Cancer Genes in Extended Pedigrees

DTIC Science & Technology

2009-07-01

contiguous window of loci. The current graphical model is applied to both the paternal and maternal haplotypes for each observed individual. The values at... paternal and maternal haplotypes of each individual in the sample in parallel. These affect the observed genotypes shown as white squares. The states...individuals, but also, by listing the parents as zero, allows for samples of unrelated individuals as required by these methods. IntervalLDwill treat

Observations of Fallout from the Fukushima Reactor Accident in San Francisco Bay Area Rainwater

PubMed Central

Norman, Eric B.; Angell, Christopher T.; Chodash, Perry A.

2011-01-01

We have observed fallout from the recent Fukushima Dai-ichi reactor accident in samples of rainwater collected in the San Francisco Bay area. Gamma ray spectra measured from these samples show clear evidence of fission products – 131,132I, 132Te, and 134,137Cs. The activity levels we have measured for these isotopes are very low and pose no health risk to the public. PMID:21957447

Optimal Asset Distribution for Environmental Assessment and Forecasting Based on Observations, Adaptive Sampling, and Numerical Prediction

DTIC Science & Technology

2012-09-30

and Forecasting Based on Observations, Adaptive Sampling, and Numerical Prediction Steven R. Ramp Soliton Ocean Services, Inc. 691 Country Club... Soliton Ocean Services, Inc,691 Country Club Drive,Monterey,CA,93924 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S...shortwave. The results show that the incoming shortwave radiation was the dominant term, even when averaged over the dark hours, which accounts

Prevalence of virus-like particles within a staghorn scleractinian coral ( Acropora muricata) from the Great Barrier Reef

NASA Astrophysics Data System (ADS)

Patten, N. L.; Harrison, P. L.; Mitchell, J. G.

2008-09-01

Transmission electron microscopy (TEM) was used to determine whether Acropora muricata coral colonies from the Great Barrier Reef (GBR), Australia, harboured virus-like particles (VLPs). VLPs were present in all coral colonies sampled at Heron Island (southern GBR) and in tagged coral colonies sampled in at least two of the three sampling periods at Lizard Island (northern GBR). VLPs were observed within gastrodermal and epidermal tissues, and on rarer occasions, within the mesoglea. These VLPs had similar morphologies to known prokaryotic and eukaryotic viruses in other systems. Icosahedral VLPs were observed most frequently, however, filamentous VLPs (FVLPs) and phage were also noted. There were no clear differences in VLP size, morphology or location within the tissues with respect to sample date, coral health status or site. The most common VLP morphotype exhibited icosahedral symmetry, 120-150 nm in diameter, with an electron-dense core and an electronlucent membrane. Larger VLPs of similar morphology were also common. VLPs occurred as single entities, in groups, or in dense clusters, either as free particles within coral tissues, or within membrane-bound vacuoles. VLPs were commonly observed within the perinuclear region, with mitochondria, golgi apparatus and crescent-shaped particles frequently observed within close proximity. The host(s) of these observed VLPs was not clear; however, the different sizes and morphologies of VLPs observed within A. muricata tissues suggest that viruses are infecting either the coral animal, zooxanthellae, intracellular bacteria and/or other coral-associated microbiota, or that the one host is susceptible to infection from more than one type of virus. These results add to the limited but emerging body of evidence that viruses represent another potentially important component of the coral holobiont.

A BCool survey of the magnetic fields of planet-hosting solar-type stars

NASA Astrophysics Data System (ADS)

Mengel, M. W.; Marsden, S. C.; Carter, B. D.; Horner, J.; King, R.; Fares, R.; Jeffers, S. V.; Petit, P.; Vidotto, A. A.; Morin, J.; BCool Collaboration

2017-03-01

We present a spectropolarimetric snapshot survey of solar-type planet-hosting stars. In addition to 14 planet-hosting stars observed as part of the BCool magnetic snapshot survey, we obtained magnetic observations of a further 19 planet-hosting solar-type stars in order to see if the presence of close-in planets had an effect on the measured surface magnetic field (|Bℓ|). Our results indicate that the magnetic activity of this sample is congruent with that of the overall BCool sample. The effects of the planetary systems on the magnetic activity of the parent star, if any, are too subtle to detect compared to the intrinsic dispersion and correlations with rotation, age and stellar activity proxies in our sample. Four of the 19 newly observed stars, two of which are subgiants, have unambiguously detected magnetic fields and are future targets for Zeeman-Doppler mapping.

Different decay patterns observed in a nineteenth-century building (Palma, Spain).

PubMed

Genestar, Catalina; Pons, Carmen; Cerro, José Carlos; Cerdà, Víctor

2014-01-01

The effects of atmospheric pollutants and climatic conditions were studied in a decayed column in the Seminary of Sant Pere. This nineteenth-century building is situated in the historic centre of Palma (Mallorca, Spain), less than 0.5 km from the sea. Samples were collected from the internal and external part of the crusts formed in the four sides of the column. The samples were analysed by means of thermal analysis, X-ray diffractometry, scanning electron microscopy, Fourier transform infrared spectroscopy and ion chromatography. Results show significant differences in the four sides of the column. A high degree of carbonate stone sulfation is observed in all of the samples analysed. A synergistic effect between atmospheric factors and micropollutants on the deterioration of stone is observed. A high uptake of atmospheric particulate matter is found in the external part of the black crusts.

Learning Bayesian Networks from Correlated Data

NASA Astrophysics Data System (ADS)

Bae, Harold; Monti, Stefano; Montano, Monty; Steinberg, Martin H.; Perls, Thomas T.; Sebastiani, Paola

2016-05-01

Bayesian networks are probabilistic models that represent complex distributions in a modular way and have become very popular in many fields. There are many methods to build Bayesian networks from a random sample of independent and identically distributed observations. However, many observational studies are designed using some form of clustered sampling that introduces correlations between observations within the same cluster and ignoring this correlation typically inflates the rate of false positive associations. We describe a novel parameterization of Bayesian networks that uses random effects to model the correlation within sample units and can be used for structure and parameter learning from correlated data without inflating the Type I error rate. We compare different learning metrics using simulations and illustrate the method in two real examples: an analysis of genetic and non-genetic factors associated with human longevity from a family-based study, and an example of risk factors for complications of sickle cell anemia from a longitudinal study with repeated measures.

The quality of feeding assistance care practices for long-term care veterans: implications for quality improvement efforts.

PubMed

Simmons, Sandra F; Sims, Nichole; Durkin, Daniel W; Shotwell, Matthew S; Erwin, Scott; Schnelle, John F

2013-09-01

The primary purpose of this study was to determine the quality of feeding assistance care and identify areas in need of improvement for a sample of long-term care veterans. A secondary purpose was to compare these findings with the results of previous studies in community facilities to determine ways in which the VA sample might differ. A repeated measures observational study was conducted in two VA facilities with 200 long-stay residents. Research staff conducted standardized observations during and between meals for 3 months. There was a trend for better feeding assistance care quality during meals in the VA sample, but there were still multiple aspects of care in need of improvement both during and between meals. Higher licensed nurse staffing levels in the VA should enable effective supervision and management, but observation-based measures of care quality are necessary for accurate information about daily feeding assistance care provision.

Missing observations in multiyear rotation sampling designs

NASA Technical Reports Server (NTRS)

Gbur, E. E.; Sielken, R. L., Jr. (Principal Investigator)

1982-01-01

Because Multiyear estimation of at-harvest stratum crop proportions is more efficient than single year estimation, the behavior of multiyear estimators in the presence of missing acquisitions was studied. Only the (worst) case when a segment proportion cannot be estimated for the entire year is considered. The effect of these missing segments on the variance of the at-harvest stratum crop proportion estimator is considered when missing segments are not replaced, and when missing segments are replaced by segments not sampled in previous years. The principle recommendations are to replace missing segments according to some specified strategy, and to use a sequential procedure for selecting a sampling design; i.e., choose an optimal two year design and then, based on the observed two year design after segment losses have been taken into account, choose the best possible three year design having the observed two year parent design.

Structural analysis of geochemical samples by solid-state nuclear magnetic resonance spectrometry. Role of paramagnetic material

USGS Publications Warehouse

Vassallo, A.M.; Wilson, M.A.; Collin, P.J.; Oades, J.M.; Waters, A.G.; Malcolm, R.L.

1987-01-01

An examination of coals, coal tars, a fulvic acid, and soil fractions by solid-state 13C NMR spectrometry has demonstrated widely differing behavior regarding quantitative representation in the spectrum. Spin counting experiments on coal tars and the fulvic acid show that almost all the sample carbon is observed in both solution and solid-state NMR spectra. Similar experiments on two coals (a lignite and a bituminous coal) show that most (70-97%) of the carbon is observed; however, when the lignite is ion exchanged with 3% (w/w) Fe3+, the fraction of carbon observed drops to below 10%. In additional experiments signal intensity from soil samples is enhanced by a simple dithionite treatment. This is illustrated by 13C, 27Al, and 29Si solid-state NMR experiments on soil fractions. ?? 1987 American Chemical Society.

Observation of Superconductivity in Tetragonal FeS.

PubMed

Lai, Xiaofang; Zhang, Hui; Wang, Yingqi; Wang, Xin; Zhang, Xian; Lin, Jianhua; Huang, Fuqiang

2015-08-19

The possibility of superconductivity in tetragonal FeS has attracted considerable interest because of its similarities to the FeSe superconductor. However, all efforts made to pursue superconductivity in tetragonal FeS have failed so far, and it remains controversial whether tetragonal FeS is metallic or semiconducting. Here we report the observation of superconductivity at 5 K in tetragonal FeS that is synthesized by the hydrothermal reaction of iron powder with sulfide solution. The obtained samples are highly crystalline and less air-sensitive, in contrast to those reported in the literature, which are meta-stable and air-sensitive. Magnetic and electrical properties measurements show that the samples behave as a paramagnetic metal in the normal state and exhibit superconductivity below 5 K. The high crystallinity and the stoichiometry of the samples play important roles in the observation of superconductivity. The present results demonstrate that tetragonal FeS is a promising new platform to realize high-temperature superconductors.

A fundamental study of chromium deposition on solid oxide fuel cell cathode materials

NASA Astrophysics Data System (ADS)

Tucker, Michael C.; Kurokawa, Hideto; Jacobson, Craig P.; De Jonghe, Lutgard C.; Visco, Steven J.

Chromium contamination of metal oxides and SOFC cathode catalysts is studied in the range 700-1000 °C. Samples are exposed to a moist air atmosphere saturated with volatile Cr species in the presence and absence of direct contact between the sample and ferritic stainless steel powder. Chromium contamination of the samples is observed to occur via two separate pathways: surface diffusion from the stainless steel surface and vapor deposition from the atmosphere. Surface diffusion dominates in all cases. Surface diffusion is found to be a significant source of Cr contamination for LSM and LSCF at 700, 800, and 1000 °C. Vapor deposition of Cr onto LSCF was observed at each of these temperatures, but was not observed for LSM at 700 or 800 °C. Comparison of the behavior for LSM, LSCF, and single metal oxides suggests that Mn and Co, respectively, are responsible for the Cr contamination of these catalysts.

VizieR Online Data Catalog: Red supergiant population in Perseus arm (Dorda+, 2018)

NASA Astrophysics Data System (ADS)

Dorda, R.; Negueruela, I.; Gonzalez-Fernandez, C.

2018-03-01

The targets were observed during two different campaigns. The first one was done in 2011, on the nights of October 16-18. The second campaign was carried out in 2012, from September 3rd to 7th. We used the Intermediate Dispersion Spectrograph, mounted on the 2.5 m Isaac Newton Telescope (INT) in La Palma (Spain). In total, we observed 637 unique targets, 102 in 2011 and 535 in 2012, without any overlap between epochs. As discussed above, 43 of them are CSGs with well-determined SpTs (all but one observed in the 2012 run) that were included in the calibration sample of Paper III (see appendix B in that work). These objects are not considered part of the Perseus sample studied here. This leaves 594 targets in our sample, which are detailed in perseus.dat file. (1 data file).

Laser Plasma Soft X-ray Microscope with Wolter Mirrors for Observation of Biological Specimens in Air

NASA Astrophysics Data System (ADS)

Hoshino, Masato; Aoki, Sadao

2006-02-01

A laser plasma soft X-ray microscope with Wolter mirrors was developed so that specimens could be set in the atmosphere. Silicon nitride membranes 100 nm thick were used as vacuum-tight windows. Using relatively large windows (0.46× 0.46 mm2), an adequate working distance for samples, which was approximately 1.2 mm, was assured. The endurance of the vacuum-tight window was measured briefly. Dry biological cells could be observed with resolution better than 100 nm. A preliminary observation of wet biological cells was carried out using a wet environmental sample holder which was composed of only two sheets of silicon nitride membrane. An X-ray micrograph of wet red blood cells from a chicken was obtained without apparent effects of radiation damage. The properties of a vacuum-tight window and a wet sample holder are discussed.

Effects of mechanical strain amplitude on the isothermal fatigue behavior of H13

NASA Astrophysics Data System (ADS)

Zeng, Yan; Zuo, Peng-peng; Wu, Xiao-chun; Xia, Shu-wen

2017-09-01

Isothermal fatigue (IF) tests were performed on H13 tool steel subjected to three different mechanical strain amplitudes at a constant temperature to determine the effects of mechanical strain amplitude on the microstructure of the steel samples. The samples' extent of damage after IF tests was compared by observation of their cracks and calculation of their damage parameters. Optical microscopy (OM) and scanning electron microscopy (SEM) were used to observe the microstructure of the samples. Cracks were observed to initiate at the surface because the strains and stresses there were the largest during thermal cycling. Mechanical strain accelerated the damage and softening of the steel. A larger mechanical strain caused greater deformation of the steel, which made the precipitated carbides easier to gather and grow along the deformation direction, possibly resulting in softening of the material or the initiation of cracks.

Excitation-based and informational masking of a tonal signal in a four-tone masker.

PubMed

Leibold, Lori J; Hitchens, Jack J; Buss, Emily; Neff, Donna L

2010-04-01

This study examined contributions of peripheral excitation and informational masking to the variability in masking effectiveness observed across samples of multi-tonal maskers. Detection thresholds were measured for a 1000-Hz signal presented simultaneously with each of 25, four-tone masker samples. Using a two-interval, forced-choice adaptive task, thresholds were measured with each sample fixed throughout trial blocks for ten listeners. Average thresholds differed by as much as 26 dB across samples. An excitation-based model of partial loudness [Moore, B. C. J. et al. (1997). J. Audio Eng. Soc. 45, 224-237] was used to predict thresholds. These predictions accounted for a significant portion of variance in the data of several listeners, but no relation between the model and data was observed for many listeners. Moreover, substantial individual differences, on the order of 41 dB, were observed for some maskers. The largest individual differences were found for maskers predicted to produce minimal excitation-based masking. In subsequent conditions, one of five maskers was randomly presented in each interval. The difference in performance for samples with low versus high predicted thresholds was reduced in random compared to fixed conditions. These findings are consistent with a trading relation whereby informational masking is largest for conditions in which excitation-based masking is smallest.

Temperature influence on the fast pyrolysis of manure samples: char, bio-oil and gases production

NASA Astrophysics Data System (ADS)

Fernandez-Lopez, Maria; Anastasakis, Kostas; De Jong, Wiebren; Valverde, Jose Luis; Sanchez-Silva, Luz

2017-11-01

Fast pyrolysis characterization of three dry manure samples was studied using a pyrolyzer. A heating rate of 600°C/s and a holding time of 10 s were selected to reproduce industrial conditions. The effect of the peak pyrolysis temperature (600, 800 and 1000°C) on the pyrolysis product yield and composition was evaluated. Char and bio-oil were gravimetrically quantified. Scanning electron microscopy (SEM) was used to analyse the char structure. H2, CH4, CO and CO2 were measured by means of gas chromatography (GC). A decrease in the char yield and an increase of the gas yield were observed when temperature increased. From 800°C on, it was observed that the char yield of samples Dig R and SW were constant, which indicated that the primary devolatilization reactions stopped. This fact was also corroborated by GC analysis. The bio-oil yield slightly increased with temperature, showing a maximum of 20.7 and 27.8 wt.% for samples Pre and SW, respectively, whereas sample Dig R showed a maximum yield of 16.5 wt.% at 800°C. CO2 and CO were the main released gases whereas H2 and CH4 production increased with temperature. Finally, an increase of char porosity was observed with temperature.

Evidence of refractory organic matter preserved in the mudstones of Yellowknife Bay and the Murray Formations

NASA Astrophysics Data System (ADS)

Eigenbrode, J. L.; Steele, A.; Summons, R. E.; Sutter, B.; McAdam, A.; Franz, H. B.; Mahaffy, P. R.; Conrad, P. G.; Freissinet, C.; Glavin, D. P.; Millan, M.; Ming, D. W.

2015-12-01

Volatiles from high-temperature (above 500°C) pyrolysis of drilled and sieved deltaic/lacustrine mudstones at Yellowknife Bay and Pahrump Hills were detected by the Sample Analysis at Mars (SAM) instrument's evolved gas analysis experiment onboard the Curiosity rover in Gale Crater, Mars. Mass fragments detected from the mudstones are consistent with C1-C4 alkyl and single-ring aromatic components that evolve at different temperatures and often in multiple phases. Concurrent release of oxidized sulfur (sulfur dioxide and sulfur trioxide), sulfide gases (hydrogen sulfide, carbonyl sulfide, carbon disulfide, dimethylsulfide or thiol, and thiophene) suggest that either these gases are evolving directly from the mudstone or are products of gas phase reactions in the SAM oven, or both. Multiple chlorohydrocarbon releases are also observed in analysis of the Mojave mudstone indicating punctuated organic releases from the sample. The organic signatures observed are unique to specific samples and are not observed in blanks or all samples, nor can the SAM background explain them. These results suggest that geologically refractory organic matter has been preserved in some Hesperian mudstones despite possible acid-sulfate weathering (as suggested by jarosite in Mojave) and exposure to ionizing cosmic rays after exhumation. We will report on ongoing study of these samples.

Prospective, randomized, blinded evaluation of donor semen quality provided by seven commercial sperm banks.

PubMed

Carrell, Douglas T; Cartmill, Deborah; Jones, Kirtly P; Hatasaka, Harry H; Peterson, C Matthew

2002-07-01

To evaluate variability in donor semen quality between seven commercial donor sperm banks, within sperm banks, and between intracervical insemination and intrauterine insemination. Prospective, randomized, blind evaluation of commercially available donor semen samples. An academic andrology laboratory. Seventy-five cryopreserved donor semen samples were evaluated. Samples were coded, then blindly evaluated for semen quality. Standard semen quality parameters, including concentration, motility parameters, World Health Organization criteria morphology, and strict criteria morphology. Significant differences were observed between donor semen banks for most semen quality parameters analyzed in intracervical insemination samples. In general, the greatest variability observed between banks was in percentage progressive sperm motility (range, 8.8 +/- 5.8 to 42.4 +/- 5.5) and normal sperm morphology (strict criteria; range, 10.1 +/- 3.3 to 26.6 +/- 4.7). Coefficients of variation within sperm banks were generally high. These data demonstrate the variability of donor semen quality provided by commercial sperm banks, both between banks and within a given bank. No relationship was observed between the size or type of sperm bank and the degree of variability. The data demonstrate the lack of uniformity in the criteria used to screen potential semen donors and emphasize the need for more stringent screening criteria and strict quality control in processing samples.

Geoscience Australia Publishes Sample Descriptions using W3C standards

NASA Astrophysics Data System (ADS)

Car, N. J.; Cox, S. J. D.; Bastrakova, I.; Wyborn, L. A.

2017-12-01

The recent revision of the W3C Semantic Sensor Network Ontology (SSN) has focused on three key concerns: Extending the scope of the ontology to include sampling and actuation as well as observation and sensing Modularizing the ontology into a simple core with few classes and properties and little formal axiomatization, supplemented by additional modules that formalize the semantics and extend the scope Alignments with several existing applications and upper ontologies These enhancements mean that SSN can now be used as the basis for publishing descriptions of geologic samples as Linked Data. Geoscience Australia maintains a database of about three million samples, collected over 50 years through projects from ocean core, terrestrial rock and hydrochemistry borehole projects, almost all of which are held in in the special-purpose GA samples repository. Access to descriptions of these samples as Linked Data has recently been enabled. The sample descriptions can be viewed in various machine-readable formalizations, including IGSN (XML & RDF), Dublin Core (XML & RDF) and SSN (RDF), as well as web landing-pages for people. Of particular importance is the support for encoding relationships between samples, and between samples and surveys, boreholes, and traverses which they are related to, as well as between samples processed for analytical purposes and their parents, siblings, and back to the original field samples. The SSN extension for Sample Relationships provides an extensible, semantically rich mechanism to capture any relationship necessary to explain the provenance of observation results obtained from samples. Sample citation is facilitated through the use of URI-based persistent identifiers which resolve to samples' landing pages. The sample system also allows PROV pingbacks to be received for samples when users of them record provenance for their actions.

Structural elucidation and magnetic behavior evaluation of Cu-Cr doped BaCo-X hexagonal ferrites

NASA Astrophysics Data System (ADS)

Azhar Khan, Muhammad; Hussain, Farhat; Rashid, Muhammad; Mahmood, Asif; Ramay, Shahid M.; Majeed, Abdul

2018-04-01

Ba2-xCuxCo2CryFe28-yO46 (x = 0.0, 0.1, 0.2, 0.3, 0.4, y = 0.0, 0.2, 0.4, 0.6, 0.8) X-type hexagonal ferrites were synthesized via micro-emulsion route. The techniques which were applied to characterize the prepared samples are as follows: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Dielectric measurements and vibrating sample magnetometer (VSM). The structural parameters i.e. lattice constant (a, c), cell volume (V), X-ray density, bulk density and crystallite size of all the prepared samples were obtained using XRD analysis. The lattice parameters 'a' and 'c' increase from 5.875 Å to 5.934 Å and 83.367 Å to 83.990 Å respectively. The crystallite size of investigated samples lies in the range of 28-32 nm. The magnetic properties of all samples have been calculated by vibrating sample magnetometer (VSM) analysis. The increase in coercivity (Hc) was observed with the increase of doping contents. It was observed that the coercivity (Hc) of all prepared samples is inversely related to the crystalline size which reflects that all materials are super-paramagnetic. The dielectric parameters i.e. dielectric constant, dielectric loss, tangent loss etc were obtained in the frequency range of 1 MHz-3 GHz and followed the Maxwell-Wagner's model. The significant variation the dielectric parameters are observed with increasing frequency. The maximum Q value is obtained at ∼2 GHz due to which these materials are used for high frequency multilayer chip inductors.

Nontuberculous Mycobacteria, Fungi, and Opportunistic Pathogens in Unchlorinated Drinking Water in the Netherlands

PubMed Central

van der Kooij, Dick

2013-01-01

The multiplication of opportunistic pathogens in drinking water supplies might pose a threat to public health. In this study, distributed unchlorinated drinking water from eight treatment plants in the Netherlands was sampled and analyzed for fungi, nontuberculous mycobacteria (NTM), and several opportunistic pathogens by using selective quantitative PCR methods. Fungi and NTM were detected in all drinking water samples, whereas Legionella pneumophila, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Aspergillus fumigatus were sporadically observed. Mycobacterium avium complex and Acanthamoeba spp. were not detected. Season had no influence on the occurrence of these organisms, except for NTM and S. maltophilia, which were present in higher numbers in the summer. Opportunistic pathogens were more often observed in premise plumbing water samples than in samples from the distribution system. The lowest number of these organisms was observed in the finished water at the plant. Thus, fungi, NTM, and some of the studied opportunistic pathogens can multiply in the distribution and premise plumbing systems. Assimilable organic carbon (AOC) and/or total organic carbon (TOC) had no clear effects on fungal and NTM numbers or on P. aeruginosa- and S. maltophilia-positive samples. However, L. pneumophila was detected more often in water with AOC concentrations above 10 μg C liter−1 than in water with AOC levels below 5 μg C liter−1. Finally, samples that contained L. pneumophila, P. aeruginosa, or S. maltophilia were more frequently positive for a second opportunistic pathogen, which shows that certain drinking water types and/or sampling locations promote the growth of multiple opportunistic pathogens. PMID:23160134

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.

Nontuberculous mycobacteria, fungi, and opportunistic pathogens in unchlorinated drinking water in The Netherlands.

PubMed

van der Wielen, Paul W J J; van der Kooij, Dick

2013-02-01

The multiplication of opportunistic pathogens in drinking water supplies might pose a threat to public health. In this study, distributed unchlorinated drinking water from eight treatment plants in the Netherlands was sampled and analyzed for fungi, nontuberculous mycobacteria (NTM), and several opportunistic pathogens by using selective quantitative PCR methods. Fungi and NTM were detected in all drinking water samples, whereas Legionella pneumophila, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Aspergillus fumigatus were sporadically observed. Mycobacterium avium complex and Acanthamoeba spp. were not detected. Season had no influence on the occurrence of these organisms, except for NTM and S. maltophilia, which were present in higher numbers in the summer. Opportunistic pathogens were more often observed in premise plumbing water samples than in samples from the distribution system. The lowest number of these organisms was observed in the finished water at the plant. Thus, fungi, NTM, and some of the studied opportunistic pathogens can multiply in the distribution and premise plumbing systems. Assimilable organic carbon (AOC) and/or total organic carbon (TOC) had no clear effects on fungal and NTM numbers or on P. aeruginosa- and S. maltophilia-positive samples. However, L. pneumophila was detected more often in water with AOC concentrations above 10 μg C liter(-1) than in water with AOC levels below 5 μg C liter(-1). Finally, samples that contained L. pneumophila, P. aeruginosa, or S. maltophilia were more frequently positive for a second opportunistic pathogen, which shows that certain drinking water types and/or sampling locations promote the growth of multiple opportunistic pathogens.

Population description and its role in the interpretation of genetic association

PubMed Central

Yu, Joon-Ho; Crouch, Julia; Fryer-Edwards, Kelly; Burke, Wylie

2010-01-01

Despite calls for greater clarity and precision of population description, studies have documented persistent ambiguity in the use of race/ethnicity terms in genetic research. It is unclear why investigators tolerate such ambiguity, or what effect these practices have on the evaluation of reported associations. To explore the way that population description is used to replicate and/or extend previously reported genetic observations, we examined articles describing the association of the peroxisome proliferator-activated receptor-gamma-γ Pro12Ala polymorphism with type 2 diabetes mellitus and related phenotypes, published between 1997 and 2005. The 80 articles identified were subjected to a detailed content analysis to determine (1) how sampled populations were described, (2) whether and how the choice of sample was explained, and (3) how the allele frequency and genetic association findings identified were contextualized and interpreted. In common with previous reports, we observed a variety of sample descriptions and little explanation for the choice of population investigated. Samples of European origin were typically described with greater specificity than samples of other origin. However, findings from European samples were nearly always compared to samples described as “Caucasian” and sometimes generalized to all Caucasians or to all humans. These findings suggest that care with population description, while important, may not fully address analytical concerns regarding the interpretation of variable study outcomes or ethical concerns regarding the attribution of genetic observations to broad social groups. Instead, criteria which help investigators better distinguish justified and unjustified forms of population generalization may be required. PMID:20157827

Multi-wavelength observations of barred, flocculent galaxies

NASA Astrophysics Data System (ADS)

Ratay, Douglas Lee

Although it is generally accepted that large galaxies form through the assemblage of smaller objects, an explanation for the morphology of galaxies is not available. Any complete theory of galaxy morphology must include production and dissolution mechanisms for galactic bars, rings, nuclear bars, spiral arms, and companions. This theory does not exist because of the lack of detailed data from many types of galaxies in different environments. We have defined a new sample of galaxies which are simultaneously flocculent, barred, and isolated. We have performed optical, near-infrared, and radio (HI) observations of the galaxies in this sample. We measured properties of our galaxies including bar length, bar axis ratio, HI diameter, HI mass, and dynamical mass. We found that our sample group is heterogeneous, and compares well to a standard samples of galaxies. We found two of our galaxies to possess companions, and two others to show evidence of current interactions. This is consistent with other observations indicating that local isolated galaxies do not possess a large number of small companions. We cannot rule out the possibility of very small companions. We find that as a group our sample is slightly less luminous than normal galaxies and may be more likely to be involved in interactions. We conclude that the bar and spiral arm features in our sample are due to processes internal to the galaxies, likely involving the interaction between the galactic disk and halo. We defined a control sample of barred, grand design galaxies to further determine the acceptability of barred, flocculent galaxies as a physically meaningful subset of galaxies.

Shock Response of Commercial Purity Polycrystalline Magnesium Under Uniaxial Strain at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Wang, Tianxue; Zuanetti, Bryan; Prakash, Vikas

2017-12-01

In the present paper, results of plate impact experiments designed to investigate the onset of incipient plasticity in commercial purity polycrystalline magnesium (99.9%) under weak uniaxial strain compression and elevated temperatures up to melt are presented. The dynamic stress at yield and post yield of magnesium, as inferred from the measured normal component of the particle velocity histories at the free (rear) surface of the target plate, are observed to decrease progressively with increasing test temperatures in the range from 23 to 500 °C. At (higher) test temperatures in the range 500-610 °C, the rate of decrease of dynamic stress with temperature at yield and post-yield in the sample is observed to weaken. At still higher test temperatures (617 and 630 °C), a dramatic increase in dynamic yield as well as flow stress is observed indicating a change in dominant mechanism of plastic deformation as the sample approaches the melt point of magnesium at strain rates of 105/s. In addition to these measurements at the wavefront, the plateau region of the free surface particle velocity profiles indicates that the longitudinal (plastic) impedance of the magnesium samples decreases continuously as the sample temperatures are increased from room to 610 °C, and then reverses trend (indicating increasing material longitudinal impedance/strength) as the sample temperatures are increased to 617 and 630 °C. Electron back scattered diffraction analysis of the as-received and annealed pre-test magnesium samples reveal grain coarsening as well as grain re-orientation to a different texture during the heating process of the samples.

A diurnal component to the variation in sieve tube amino acid content in wheat.

PubMed

Gattolin, Stefano; Newbury, H John; Bale, Jeffrey S; Tseng, Hua-Ming; Barrett, David A; Pritchard, Jeremy

2008-06-01

We have used high-sensitivity capillary electrophoresis coupled to a laser-induced fluorescence detection method to quantify 16 amino acids in wheat (Triticum aestivum) sieve tube (ST) samples as small as 2 nL collected by severing the stylets of feeding aphids. The sensitivity of the method was sufficient to determine a quantitative amino acid profile of individual STs without the need to bulk samples to produce larger volumes for analysis. This allowed the observation of the full range of variation that exists in individual STs. Some of the total concentrations of amino acids recorded are higher than those reported previously. The results obtained show variation in the concentrations of phenylalanine (Phe), histidine/valine (His/Val), leucine/isoleucine (Leu/Ile), arginine, asparagine, glutamine, tyrosine (Tyr), and lysine (Lys) across the ST samples. These could not be explained by plant-to-plant variation. Statistical analyses revealed five analytes (Tyr, Lys, Phe, His/Val, and Leu/Ile) that showed striking covariation in their concentrations across ST samples. A regression analysis revealed a significant relationship between the concentrations of Tyr, Lys, Phe, Leu/Ile, His/Val, asparagine, arginine, and proline and the time of collection of ST samples, with these amino acids increasing in concentration during the afternoon. This increase was confirmed to occur in individual STs by analyzing samples obtained from stylet bundles exuding for many hours. Finally, an apparent relationship between the exudation rate of ST sap and its total amino acid concentration was observed: samples containing higher total amino acid concentrations were observed to exude from the severed stylet bundles more slowly.

Study of the Effect of Temporal Sampling Frequency on DSCOVR Observations Using the GEOS-5 Nature Run Results. Part II; Cloud Coverage

NASA Technical Reports Server (NTRS)

Holdaway, Daniel; Yang, Yuekui

2016-01-01

This is the second part of a study on how temporal sampling frequency affects satellite retrievals in support of the Deep Space Climate Observatory (DSCOVR) mission. Continuing from Part 1, which looked at Earth's radiation budget, this paper presents the effect of sampling frequency on DSCOVR-derived cloud fraction. The output from NASA's Goddard Earth Observing System version 5 (GEOS-5) Nature Run is used as the "truth". The effect of temporal resolution on potential DSCOVR observations is assessed by subsampling the full Nature Run data. A set of metrics, including uncertainty and absolute error in the subsampled time series, correlation between the original and the subsamples, and Fourier analysis have been used for this study. Results show that, for a given sampling frequency, the uncertainties in the annual mean cloud fraction of the sunlit half of the Earth are larger over land than over ocean. Analysis of correlation coefficients between the subsamples and the original time series demonstrates that even though sampling at certain longer time intervals may not increase the uncertainty in the mean, the subsampled time series is further and further away from the "truth" as the sampling interval becomes larger and larger. Fourier analysis shows that the simulated DSCOVR cloud fraction has underlying periodical features at certain time intervals, such as 8, 12, and 24 h. If the data is subsampled at these frequencies, the uncertainties in the mean cloud fraction are higher. These results provide helpful insights for the DSCOVR temporal sampling strategy.

Antisite disorder induced spin glass and exchange bias effect in Nd2NiMnO6 epitaxial thin film

NASA Astrophysics Data System (ADS)

Singh, Amit Kumar; Chauhan, Samta; Chandra, Ramesh

2017-03-01

We report the observation of the exchange bias effect and spin glass behaviour at low temperature in a ferromagnetic Nd2NiMnO6 epitaxial thin film. Along with the ferromagnetic transition at ˜194 K, an additional transition is observed at lower temperature (˜55 K) as seen from M-T curves of the sample. A shift in the ac susceptibility peak with frequency has been observed at low temperature, which is a signature of a glassy phase within the sample. The detailed investigation of the memory effect and time dependent magnetic relaxation measurements reveals the presence of a spin glass phase in the Nd2NiMnO6 thin film. The exchange bias effect observed at low temperature in the sample has been associated with an antisite disorder induced spin glass phase, which results in a ferromagnetic/spin glass interface at low temperature. The exchange bias behaviour has been further confirmed by performing cooling field and temperature dependence of exchange bias along with training effect measurements.

Juno Magnetometer Observations in the Earth's Magnetosphere

NASA Astrophysics Data System (ADS)

Connerney, J. E.; Oliversen, R. J.; Espley, J. R.; MacDowall, R. J.; Schnurr, R.; Sheppard, D.; Odom, J.; Lawton, P.; Murphy, S.; Joergensen, J. L.; Joergensen, P. S.; Merayo, J. M.; Denver, T.; Bloxham, J.; Smith, E. J.; Murphy, N.

2013-12-01

The Juno spacecraft enjoyed a close encounter with Earth on October 9, 2013, en route to Jupiter Orbit Insertion (JOI) on July 5, 2016. The Earth Flyby (EFB) provided a unique opportunity for the Juno particles and fields instruments to sample mission relevant environments and exercise operations anticipated for orbital operations at Jupiter, particularly the period of intense activity around perijove. The magnetic field investigation onboard Juno is equipped with two magnetometer sensor suites, located at 10 and 12 m from the spacecraft body at the end of one of the three solar panel wings. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads which provide accurate attitude determination for the FGM sensors. This very capable magnetic observatory sampled the Earth's magnetic field at 64 vector samples/second throughout passage through the Earth's magnetosphere. We present observations of the Earth's magnetic field and magnetosphere obtained throughout the encounter and compare these observations with those of other Earth-orbiting assets, as available, and with particles and fields observations acquired by other Juno instruments operated during EFB.

Circadian Rhythm of Pyrocystis fusiformis

NASA Astrophysics Data System (ADS)

Weishaar, B.

2016-12-01

For the Academy of Science St. Louis Science Fair, I tested how different photoperiods affect the morphology of Pyrocystis fusiformis with respect to the placement and formation of the chloroplasts. I set up four different rooms to observe the effect the different times in the photoperiod on location of chloroplasts in the cell. At 3:00pm, one room has been in the dark for 12 hours, one for 6 hours, one had been in the light phase for 12 hours and the fourth in the light phase for 6 hours. P fusiformis samples were obtained from each room, observed, photographed at X100 power, and categorized as being a 1, 2, 3, or 4 depending on the position of the chloroplasts. The samples in the different rooms were observed once a week for two weeks, then the samples were rotated to see if P. fusiformis would synchronize the same to the new photoperiod. It was observed that the cells changed morphological stages in the circadian cycle, the chloroplasts moved further away from the nucleus when exposed to light and moved closer to the nucleus when experiencing no light.

The Simultaneous Medicina-Planck Experiment: data acquisition, reduction and first results

NASA Astrophysics Data System (ADS)

Procopio, P.; Massardi, M.; Righini, S.; Zanichelli, A.; Ricciardi, S.; Libardi, P.; Burigana, C.; Cuttaia, F.; Mack, K.-H.; Terenzi, L.; Villa, F.; Bonavera, L.; Morgante, G.; Trigilio, C.; Trombetti, T.; Umana, G.

2011-10-01

The Simultaneous Medicina-Planck Experiment (SiMPlE) is aimed at observing a selected sample of 263 extragalactic and Galactic sources with the Medicina 32-m single-dish radio telescope in the same epoch as the Planck satellite observations. The data, acquired with a frequency coverage down to 5 GHz and combined with Planck at frequencies above 30 GHz, will constitute a useful reference catalogue of bright sources over the whole Northern hemisphere. Furthermore, source observations performed in different epochs and comparisons with other catalogues will allow the investigation of source variabilities on different time-scales. In this work, we describe the sample selection, the ongoing data acquisition campaign, the data reduction procedures, the developed tools and the comparison with other data sets. We present 5 and 8.3 GHz data for the SiMPlE Northern sample, consisting of 79 sources with δ≥ 45° selected from our catalogue and observed during the first 6 months of the project. A first analysis of their spectral behaviour and long-term variability is also presented.

Using larval fish community structure to guide long-term monitoring of fish spawning activity

USGS Publications Warehouse

Pritt, Jeremy J.; Roseman, Edward F.; Ross, Jason E.; DeBruyne, Robin L.

2015-01-01

Larval fishes provide a direct indication of spawning activity and may therefore be useful for long-term monitoring efforts in relation to spawning habitat restoration. However, larval fish sampling can be time intensive and costly. We sought to understand the spatial and temporal structure of larval fish communities in the St. Clair–Detroit River system, Michigan–Ontario, to determine whether targeted larval fish sampling can be made more efficient for long-term monitoring. We found that larval fish communities were highly nested, with lower river segments and late-spring samples containing the highest genus richness of larval fish. We created four sampling scenarios for each river system: (1) using all available data, (2) limiting temporal sampling to late spring, (3) limiting spatial sampling to lower river segments only, and (4) limiting both spatial and temporal sampling. By limiting the spatial extent of sampling to lower river sites and/or limiting the temporal extent to the late-spring period, we found that effort could be reduced by more than 50% while maintaining over 75% of the observed and estimated total genus richness. Similarly, limiting the sampling effort to lower river sites and/or the late-spring period maintained between 65% and 93% of the observed richness of lithophilic-spawning genera and invasive genera. In general, community composition remained consistent among sampling scenarios. Targeted sampling offers a lower-cost alternative to exhaustive spatial and temporal sampling and may be more readily incorporated into long-term monitoring.

Know Your Enemy - Implementation of Bioremediation within a Suspected DNAPL Source Zone Following High-Resolution Site Characterization at Contractors Road Heavy Equipment Area, Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Chrest, Anne; Daprato, Rebecca; Burcham, Michael; Johnson, Jill

2018-01-01

The National Aeronautics and Space Administration (NASA), Kennedy Space Center (KSC), has adopted high-resolution site characterization (HRSC) sampling techniques during baseline sampling prior to implementation of remedies to confirm and refine the conceptual site model (CSM). HRSC sampling was performed at Contractors Road Heavy Equipment Area (CRHE) prior to bioremediation implementation to verify the extent of the trichloroethene (TCE) dense non-aqueous phase liquid (DNAPL) source area (defined as the area with TCE concentrations above 1% solubility) and its daughter product dissolved plume that had been identified during previous HRSC events. The results of HRSC pre-bioremediation implementation sampling suggested that the TCE source area was larger than originally identified during initial site characterization activities, leading to a design refinement to improve electron donor distribution and increase the likelihood of achieving remedial objectives. Approach/Activities: HRSC was conducted from 2009 through 2014 to delineate the vertical and horizontal extent of chlorinated volatile organic compounds (CVOCs) in the groundwater. Approximately 2,340 samples were collected from 363 locations using direct push technology (DPT) groundwater sampling techniques. Samples were collected from up to 14 depth intervals at each location using a 4-foot sampling screen. This HRSC approach identified a narrow (approx. 5 to 30 feet wide), approximately 3,000 square foot TCE DNAPL source area (maximum detected TCE concentration of 160,000 micrograms per liter [micro-g/L] at DPT sampling location DPT0225). Prior to implementation of a bioremediation interim measure, HRSC baseline sampling was conducted using DPT groundwater sampling techniques. Concentrations of TCE were an order of magnitude lower than previous reported (12,000 micro-g/L maximum at DPT sampling location DPT0225) at locations sampled adjacent to previous sampling locations. To further evaluate the variability in concentrations observed additional sampling was conducted in 2016. The results identified higher concentrations than originally detected within the previously defined source area and the presence of source zone concentrations upgradient of the previously defined source area (maximum concentration observed 570,000 micro-g/L). The HRSC baseline sampling data allowed for a revision of the bioremediation design prior to implementation. Bioremediation was implemented within the eastern portion of the source area in November and December 2016 and quarterly performance monitoring was completed in March and June 2017. Reductions in CVOC concentrations from baseline were observed at all performance monitoring wells in the treatment area, and by June 2017, an approximate 95% CVOC mass reduction was observed based on monitoring well sampling results. Results/Lessons Learned: The results of this project suggest that, due to the complexity of DNAPL source zones, HRSC during pre-implementation baseline sampling in the TCE source zone was an essential strategy for verifying the treatment area and depth prior to remedy implementation. If the upgradient source zone mass was not identified prior to bioremediation implementation, the mass would have served as a long-term source for the dissolved plume.

The role of physical habitat and sampling effort on estimates of benthic macroinvertebrate taxonomic richness at basin and site scales.

PubMed

Silva, Déborah R O; Ligeiro, Raphael; Hughes, Robert M; Callisto, Marcos

2016-06-01

Taxonomic richness is one of the most important measures of biological diversity in ecological studies, including those with stream macroinvertebrates. However, it is impractical to measure the true richness of any site directly by sampling. Our objective was to evaluate the effect of sampling effort on estimates of macroinvertebrate family and Ephemeroptera, Plecoptera, and Trichoptera (EPT) genera richness at two scales: basin and stream site. In addition, we tried to determine which environmental factors at the site scale most influenced the amount of sampling effort needed. We sampled 39 sites in the Cerrado biome (neotropical savanna). In each site, we obtained 11 equidistant samples of the benthic assemblage and multiple physical habitat measurements. The observed basin-scale richness achieved a consistent estimation from Chao 1, Jack 1, and Jack 2 richness estimators. However, at the site scale, there was a constant increase in the observed number of taxa with increased number of samples. Models that best explained the slope of site-scale sampling curves (representing the necessity of greater sampling effort) included metrics that describe habitat heterogeneity, habitat structure, anthropogenic disturbance, and water quality, for both macroinvertebrate family and EPT genera richness. Our results demonstrate the importance of considering basin- and site-scale sampling effort in ecological surveys and that taxa accumulation curves and richness estimators are good tools for assessing sampling efficiency. The physical habitat explained a significant amount of the sampling effort needed. Therefore, future studies should explore the possible implications of physical habitat characteristics when developing sampling objectives, study designs, and calculating the needed sampling effort.

Detection probability in aerial surveys of feral horses

USGS Publications Warehouse

Ransom, Jason I.

2011-01-01

Observation bias pervades data collected during aerial surveys of large animals, and although some sources can be mitigated with informed planning, others must be addressed using valid sampling techniques that carefully model detection probability. Nonetheless, aerial surveys are frequently employed to count large mammals without applying such methods to account for heterogeneity in visibility of animal groups on the landscape. This often leaves managers and interest groups at odds over decisions that are not adequately informed. I analyzed detection of feral horse (Equus caballus) groups by dual independent observers from 24 fixed-wing and 16 helicopter flights using mixed-effect logistic regression models to investigate potential sources of observation bias. I accounted for observer skill, population location, and aircraft type in the model structure and analyzed the effects of group size, sun effect (position related to observer), vegetation type, topography, cloud cover, percent snow cover, and observer fatigue on detection of horse groups. The most important model-averaged effects for both fixed-wing and helicopter surveys included group size (fixed-wing: odds ratio = 0.891, 95% CI = 0.850–0.935; helicopter: odds ratio = 0.640, 95% CI = 0.587–0.698) and sun effect (fixed-wing: odds ratio = 0.632, 95% CI = 0.350–1.141; helicopter: odds ratio = 0.194, 95% CI = 0.080–0.470). Observer fatigue was also an important effect in the best model for helicopter surveys, with detection probability declining after 3 hr of survey time (odds ratio = 0.278, 95% CI = 0.144–0.537). Biases arising from sun effect and observer fatigue can be mitigated by pre-flight survey design. Other sources of bias, such as those arising from group size, topography, and vegetation can only be addressed by employing valid sampling techniques such as double sampling, mark–resight (batch-marked animals), mark–recapture (uniquely marked and identifiable animals), sightability bias correction models, and line transect distance sampling; however, some of these techniques may still only partially correct for negative observation biases.

LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS

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

Désert, Jean-Michel; Brown, Timothy M.; Charbonneau, David

NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) amongmore » the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated by the Kepler observations, provides an independent indication that Kepler’s FPR is low.« less

Stability of Drugs of Abuse in Urine Samples at Room Temperature by Use of a Salts Mixture.

PubMed

Pellegrini, Manuela; Graziano, Silvia; Mastrobattista, Luisa; Minutillo, Adele; Busardo, Francesco Paolo; Scarsella, Gianfranco

2017-01-01

It has long been recognized that ensuring analyte stability is of crucial importance in the use of any quantitative bioanalytical method. As analyses are usually not performed directly after collection of the biological samples, but after these have been processed and stored, it is essential that analyte stability can be maintained at storage conditions to ensure that the obtained concentration results adequately reflect those directly after sampling. The conservation of urine samples in refrigerated/ frozen conditions is strongly recommended; but not always feasible. The aim of this study was to assess the stability of some well-known drugs of abuse methamphetamine (MA), 11-nor-9-carboxy-Δ9- tetrahydrocannabinol (THC-COOH), benzoylecgonine (BE), and morphine (MOR) in urine samples kept at room temperature by adding a salt mixture (sodium citrate, sodium ascorbate, borax). Two different urine samples were prepared with and without salt mixture, stored at room temperature and then analyzed by gas chromatography-mass spectrometry at 0, 1, 7, 15, and 30 days after collection/preparation to look for eventual analyte degradation. Methamphetamine showed no significant changes with respect to the time of collection/ preparation (T0) up to 7 days later (T7), with or without salt mixture addiction. Then a significant degradation occurred in both salted and non salted urine. BE decrease was observed starting from day 1 after sample collection in salted and not salted samples, respectively. Salt addition seemed to reduce at least the initial BE degradation, with a significant difference (p<0.001) at 7 and 15 days of storage. However, the degradation was not more prevented in salted samples at 30 days of storage. A 20% decrease of MOR concentration was observed starting from day 1 after collection/preparation, both in salted and not salted samples with no subsequent decrease. With regard to THCCOOH, a significant decrease was observed starting from 7 days after collection/preparation, with of without adding the salt mixture. However, when comparing salted versus non salted samples at each time point, a statistically significant difference was observed at 7 and 30 days of storage. The results obtained indicate that the degradation of MA, THC-COOH and BE in urine samples kept at room temperature can be slowed by the addition of the salt mixture, whereas it seems to be ineffective in samples containing MOR. This evidence has to be taken into account, in the eventuality of using salted urine to prevent in a certain extent abuse of above-reported drugs of abuse. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Characterization of polymorphic states in energetic samples of 1,3,5-trinitro-1,3,5-triazine (RDX) fabricated using drop-on-demand inkjet technology.

PubMed

Emmons, Erik D; Farrell, Mikella E; Holthoff, Ellen L; Tripathi, Ashish; Green, Norman; Moon, Raphael P; Guicheteau, Jason A; Christesen, Steven D; Pellegrino, Paul M; Fountain, Augustus W

2012-06-01

The United States Army and the first responder community are evaluating optical detection systems for the trace detection of hazardous energetic materials. Fielded detection systems must be evaluated with the appropriate material concentrations to accurately identify the residue in theater. Trace levels of energetic materials have been observed in mutable polymorphic phases and, therefore, the systems being evaluated must be able to detect and accurately identify variant sample phases observed in spectral data. In this work, we report on the novel application of drop-on-demand technology for the fabrication of standardized trace 1,3,5-trinitro-1,3,5-triazine (RDX) samples. The drop-on-demand sample fabrication technique is compared both visually and spectrally to the more commonly used drop-and-dry technique. As the drop-on-demand technique allows for the fabrication of trace level hazard materials, concerted efforts focused on characterization of the polymorphic phase changes observed with low concentrations of RDX commonly used in drop-on-demand processing. This information is important when evaluating optical detection technologies using samples prepared with a drop-on-demand inkjet system, as the technology may be "trained" to detect the common bulk α phase of the explosive based on its spectral features but fall short in positively detecting a trace quantity of RDX (β-phase). We report the polymorphic shifts observed between α- and β-phases of this energetic material and discuss the conditions leading to the favoring of one phase over the other.

CALIFA: a diameter-selected sample for an integral field spectroscopy galaxy survey

NASA Astrophysics Data System (ADS)

Walcher, C. J.; Wisotzki, L.; Bekeraité, S.; Husemann, B.; Iglesias-Páramo, J.; Backsmann, N.; Barrera Ballesteros, J.; Catalán-Torrecilla, C.; Cortijo, C.; del Olmo, A.; Garcia Lorenzo, B.; Falcón-Barroso, J.; Jilkova, L.; Kalinova, V.; Mast, D.; Marino, R. A.; Méndez-Abreu, J.; Pasquali, A.; Sánchez, S. F.; Trager, S.; Zibetti, S.; Aguerri, J. A. L.; Alves, J.; Bland-Hawthorn, J.; Boselli, A.; Castillo Morales, A.; Cid Fernandes, R.; Flores, H.; Galbany, L.; Gallazzi, A.; García-Benito, R.; Gil de Paz, A.; González-Delgado, R. M.; Jahnke, K.; Jungwiert, B.; Kehrig, C.; Lyubenova, M.; Márquez Perez, I.; Masegosa, J.; Monreal Ibero, A.; Pérez, E.; Quirrenbach, A.; Rosales-Ortega, F. F.; Roth, M. M.; Sanchez-Blazquez, P.; Spekkens, K.; Tundo, E.; van de Ven, G.; Verheijen, M. A. W.; Vilchez, J. V.; Ziegler, B.

2014-09-01

We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45'' and 79.2'' and with a redshift 0.005 < z < 0.03. The mother sample contains 939 objects, 600 of which will be observed in the course of the CALIFA survey. The selection of targets for observations is based solely on visibility and thus keeps the statistical properties of the mother sample. By comparison with a large set of SDSS galaxies, we find that the CALIFA sample is representative of galaxies over a luminosity range of -19 > Mr > -23.1 and over a stellar mass range between 109.7 and 1011.4 M⊙. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of Mr = -19 (or stellar masses <109.7 M⊙) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form <10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these are statistically fully compatible with estimates from the full SDSS when accounting for large-scale structure. For full characterization of the sample, we also present a number of value-added quantities determined for the galaxies in the CALIFA sample. These include consistent multi-band photometry based on growth curve analyses; stellar masses; distances and quantities derived from these; morphological classifications; and an overview of available multi-wavelength photometric measurements. We also explore different ways of characterizing the environments of CALIFA galaxies, finding that the sample covers environmental conditions from the field to genuine clusters. We finally consider the expected incidence of active galactic nuclei among CALIFA galaxies given the existing pre-CALIFA data, finding that the final observed CALIFA sample will contain approximately 30 Sey2 galaxies. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max Planck Institute for Astronomy and the Instituto de Astrofísica de Andalucía (CSIC). Publically released data products from CALIFA are made available on the webpage http://www.caha.es/CALIFA

Lufkin_Exercise_ Setup

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

Milbrath, Brian; Sussman, Aviva Joy

As part of this training course, we have created a scenario at a location that will provide you with an opportunity to practice the techniques you have learned during the week. For the first hour, you will have the opportunity to conduct a Visual Observation and use VOB to determine ideal locations for RN soil sampling, swipe sampling, and in situ measurements. After the VOB and sampling locating, you will rotate between soil sample, swipe sample, and two in situ activities.

Creel survey sampling designs for estimating effort in short-duration Chinook salmon fisheries

USGS Publications Warehouse

McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

2013-01-01

Chinook Salmon Oncorhynchus tshawytscha sport fisheries in the Columbia River basin are commonly monitored using roving creel survey designs and require precise, unbiased catch estimates. The objective of this study was to examine the relative bias and precision of total catch estimates using various sampling designs to estimate angling effort under the assumption that mean catch rate was known. We obtained information on angling populations based on direct visual observations of portions of Chinook Salmon fisheries in three Idaho river systems over a 23-d period. Based on the angling population, Monte Carlo simulations were used to evaluate the properties of effort and catch estimates for each sampling design. All sampling designs evaluated were relatively unbiased. Systematic random sampling (SYS) resulted in the most precise estimates. The SYS and simple random sampling designs had mean square error (MSE) estimates that were generally half of those observed with cluster sampling designs. The SYS design was more efficient (i.e., higher accuracy per unit cost) than a two-cluster design. Increasing the number of clusters available for sampling within a day decreased the MSE of estimates of daily angling effort, but the MSE of total catch estimates was variable depending on the fishery. The results of our simulations provide guidelines on the relative influence of sample sizes and sampling designs on parameters of interest in short-duration Chinook Salmon fisheries.

Data Validation Package, June 2016 Groundwater Sampling at the Hallam, Nebraska, Decommissioned Reactor Site, August 2016

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

Surovchak, Scott; Miller, Michele

The 2008 Long-Term Surveillance Plan [LTSP] for the Decommissioned Hallam Nuclear Power Facility, Hallam, Nebraska (http://www.lm.doe.gov/Hallam/Documents.aspx) requires groundwater monitoring once every 2 years. Seventeen monitoring wells at the Hallam site were sampled during this event as specified in the plan. Planned monitoring locations are shown in Attachment 1, Sampling and Analysis Work Order. Water levels were measured at all sampled wells and at two additional wells (6A and 6B) prior to the start of sampling. Additionally, water levels of each sampled well were measured at the beginning of sampling. See Attachment 2, Trip Report, for additional details. Sampling and analysismore » were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated, http://energy.gov/lm/downloads/sampling-and-analysis-plan-us-department- energy-office-legacy-management-sites). Gross alpha and gross beta are the only parameters that were detected at statistically significant concentrations. Time/concentration graphs of the gross alpha and gross beta data are included in Attachment 3, Data Presentation. The gross alpha and gross beta activity concentrations observed are consistent with values previously observed and are attributed to naturally occurring radionuclides (e.g., uranium and uranium decay chain products) in the groundwater.« less

XRD and SEM study of alumina silicate porcelain insulator

NASA Astrophysics Data System (ADS)

Duddi, Dharmender; Singh, G. P.; Kalra, Swati; Shekhawat, M. S.; Tak, S. K.

2018-05-01

Higher strength electrical porcelain is a requirement of industry. This will be achieved by a specific composition of raw materials, which is consisted of clays and feldspars. Water absorption, particle size and insulating properties are of special interest now a day. China clay, Ball clay and Quartz are widely used by ceramic industries in Bikaner district of Rajasthan. Sample for present study were prepared by mixing of above clay, feldspar with MnO2, then shrinkage is observed. Bar shaped samples were prepared and heated up to a temperature of about 1185° C to observe shrinkage. For phase study of XRD and SEM are observed.

[Application of automatic photography in Schistosoma japonicum miracidium hatching experiments].

PubMed

Ming-Li, Zhou; Ai-Ling, Cai; Xue-Feng, Wang

2016-05-20

To explore the value of automatic photography in the observation of results of Schistosoma japonicum miracidium hatching experiments. Some fresh S. japonicum eggs were added into cow feces, and the samples of feces were divided into a low infested experimental group and a high infested group (40 samples each group). In addition, there was a negative control group with 40 samples of cow feces without S. japonicum eggs. The conventional nylon bag S. japonicum miracidium hatching experiments were performed. The process was observed with the method of flashlight and magnifying glass combined with automatic video (automatic photography method), and, at the same time, with the naked eye observation method. The results were compared. In the low infested group, the miracidium positive detection rates were 57.5% and 85.0% by the naked eye observation method and automatic photography method, respectively ( χ 2 = 11.723, P < 0.05). In the high infested group, the positive detection rates were 97.5% and 100% by the naked eye observation method and automatic photography method, respectively ( χ 2 = 1.253, P > 0.05). In the two infested groups, the average positive detection rates were 77.5% and 92.5% by the naked eye observation method and automatic photography method, respectively ( χ 2 = 6.894, P < 0.05). The automatic photography can effectively improve the positive detection rate in the S. japonicum miracidium hatching experiments.

Particulate contamination from siliconized rubber closures for freeze drying.

PubMed

Gebhardt, U; Grumbridge, N A; Knoch, A

1996-01-01

It can be shown that siliconized closures for freeze drying may cause the opalescence and turbidity observed in freeze-dried products after reconstitution. Closures of different rubber composition show different intensities of turbidity when treated identically with the same quantity and type of silicone oil. Clear solutions are obtained after reconstitution if ETFE-coated closures are used instead of siliconized closures. Samples stored at 4 degrees C for up to 6 months show no change in the intensity of turbidity, while the turbidity of samples manufactured with siliconized closures and stored at higher temperatures increase with time. Samples with ETFE-coated closures show clear solutions when stored at 25 degrees C and 37 degrees C for up to 6 months and at 45 degrees C for 3 months. After 6 months only a very weak opalescence could be observed in these samples.

Compositional transformations in ion implanted polymers

NASA Astrophysics Data System (ADS)

Abdul-Kader, A. M.; Turos, A.; Grambole, D.; Jagielski, J.; Piątkowska, A.; Madi, N. K.; Al-Maadeed, M.

2005-10-01

Changes of surface layer composition produced by ion bombardment of polyethylene and polypropylene samples were studied. These materials are under consideration for load bearing surfaces in biological and technical applications. To improve their tribological properties, surface layers are usually modified by ionizing radiation. Therefore, to study the mechanism of transformations induced by ion beam bombardment selected polymers were implanted with H, He and Ar ions to the fluences ranging from 1 × 1013 to 2 × 1016/cm2. RBS and NRA techniques were applied for sample analysis. Important hydrogen release was observed with increasing ion dose and was correlated with the ion stopping power. Another important effect observed was the rapid oxidation of samples, which apparently occurs after exposure of implanted samples to the air. Up to 10 at.% of oxygen can be incorporated in the implanted layer.

Prevalence, level and distribution of Salmonella in shipments of imported capsicum and sesame seed spice offered for entry to the United States: observations and modeling results.

PubMed

Van Doren, Jane M; Blodgett, Robert J; Pouillot, Régis; Westerman, Ann; Kleinmeier, Daria; Ziobro, George C; Ma, Yinqing; Hammack, Thomas S; Gill, Vikas; Muckenfuss, Martin F; Fabbri, Linda

2013-12-01

In response to increased concerns about spice safety, the United States Food and Drug Administration (FDA) initiated research to characterize the prevalence and levels of Salmonella in imported spices. 299 imported dried capsicum shipments and 233 imported sesame seed shipments offered for entry to the United States were sampled. Observed Salmonella shipment prevalence was 3.3% (1500 g examined; 95% CI 1.6-6.1%) for capsicum and 9.9% (1500 g; 95% Confidence Interval (CI) 6.3-14%) for sesame seed. Within shipment contamination was not inconsistent with a Poisson distribution. Shipment mean Salmonella level estimates among contaminated shipments ranged from 6 × 10(-4) to 0.09 (capsicum) or 6 × 10(-4) to 0.04 (sesame seed) MPN/g. A gamma-Poisson model provided the best fit to observed data for both imported shipments of capsicum and imported shipments of sesame seed sampled in this study among the six parametric models considered. Shipment mean levels of Salmonella vary widely between shipments; many contaminated shipments contain low levels of contamination. Examination of sampling plan efficacy for identifying contaminated spice shipments from these distributions indicates that sample size of spice examined is critical. Sampling protocols examining 25 g samples are predicted to be able to identify a small fraction of contaminated shipments of imported capsicum or sesame seeds. Published by Elsevier Ltd.

Luminescence properties of pure and doped CaSO4 nanorods irradiated by 15 MeV e-beam

NASA Astrophysics Data System (ADS)

Salah, Numan; Alharbi, Najlaa D.; Enani, Mohammad A.

2014-01-01

Calcium sulfate (CaSO4) doped with proper activators is a highly sensitive phosphor used in different fields mainly for radiation dosimetry, lighting and display applications. In this work pure and doped nanorods of CaSO4 were produced by the co-precipitation technique. Samples from this material doped with Ag, Cu, Dy, Eu and Tb were exposed to different doses of 15 MeV e-beam and studied for their thermoluminesence (TL) and photoluminescence (PL) properties. Color center formation leading to PL emissions were investigated before and after e-beam irradiation. The samples doped with rare earths elements (i.e. Dy, Eu and Tb) were observed to have thinner nanorods than the other samples and have higher absorption in the UV region. The Ag and Tb doped samples have poor TL response to e-beam, while those activated by Cu, Dy and Eu have strong glow peaks at around 123 °C. Quite linear response curves in the whole studied exposures i.e. 0.1-100 Gy were also observed in Cu and Dy doped samples. The PL results show that pure CaSO4 nanorods have active color centers without irradiation, which could be enriched/modified by these impurities mainly rare earths and further enhanced by e-beam irradiation. Eu3+ → Eu2+ conversion is clearly observed in Eu doped sample after e-beam irradiation. These results show that these nanorods might be useful in lighting and display devices development.

Stochastic Sampling in the IMF of Galactic Open Clusters

NASA Astrophysics Data System (ADS)

Kay, Christina; Hancock, M.; Canalizo, G.; Smith, B. J.; Giroux, M. L.

2010-01-01

We sought observational evidence of the effects of stochastic sampling of the initial mass function by investigating the integrated colors of a sample of Galactic open clusters. In particular we looked for scatter in the integrated (V-K) color as previous research resulted in little scatter in the (U-B) and (B-V) colors. Combining data from WEBDA and 2MASS we determined three different colors for 287 open clusters. Of these clusters, 39 have minimum uncertainties in age and formed a standard set. A plot of the (V-K) color versus age showed much more scatter than the (U-B) versus age. We also divided the sample into two groups based on a lowest luminosity limit which is a function of age and V magnitude. We expected the group of clusters fainter than this limit to show more scatter than the brighter group. Assuming the published ages, we compared the reddening corrected observed colors to those predicted by Starburst99. The presence of stochastic sampling should increase scatter in the distribution of the differences between observed and model colors of the fainter group relative to the brighter group. However, we found that K-S tests cannot rule out that the distribution of color difference for the brighter and fainter sets come from the same parent distribution. This indistinguishabilty may result from uncertainties in the parameters used to define the groups. This result constrains the size of the effects of stochastic sampling of the initial mass function.

An examination of the association between 5-HTTLPR, combat exposure, and PTSD diagnosis among U.S. veterans.

PubMed

Liu, Yutao; Garrett, Melanie E; Dennis, Michelle F; Green, Kimberly T; Ashley-Koch, Allison E; Hauser, Michael A; Beckham, Jean C; Kimbrel, Nathan A

2015-01-01

To examine the association between the 5-HTTLPR polymorphism of the serotonin transporter (SLC6A4) gene, combat exposure, and posttraumatic stress disorder (PTSD) diagnosis and among two samples of combat-exposed veterans. The first sample included 550 non-Hispanic Black (NHB) combat-exposed veterans. The second sample included 555 non-Hispanic White (NHW) combat-exposed veterans. Participants were genotyped for the 5-HTTLPR/rs25531 variants of the SLC6A4 gene. A structured clinical interview was used to diagnose PTSD. Combat and civilian trauma exposure were assessed with validated self-report instruments. Logistic regression was used to test for main effects of 5-HTTLPR on PTSD diagnosis as well as gene x environment (GxE) interactions after adjusting for sex, ancestry proportion scores, civilian trauma exposure, and combat exposure. Within the NHB sample, a significant additive effect was observed for 5-HTTLPR (OR = 1.502, p = .0025), such that the odds of having a current diagnosis of PTSD increased by 1.502 for each additional S' allele. No evidence for an association between 5-HTTLPR and PTSD was observed in the NHW sample. In addition, no evidence for combat x 5-HTTLPR effects were observed in either sample. The present study suggests that there may be an association between 5-HTTLPR genotype and PTSD diagnosis among NHB veterans; however, no evidence for the hypothesized 5-HTTLPR x combat interaction was found.

Targeting of colony-stimulating factor 1 receptor (CSF1R) in the CLL microenvironment yields antineoplastic activity in primary patient samples.

PubMed

Edwards V, David K; Sweeney, David Tyler; Ho, Hibery; Eide, Christopher A; Rofelty, Angela; Agarwal, Anupriya; Liu, Selina Qiuying; Danilov, Alexey V; Lee, Patrice; Chantry, David; McWeeney, Shannon K; Druker, Brian J; Tyner, Jeffrey W; Spurgeon, Stephen E; Loriaux, Marc M

2018-05-15

In many malignancies, the tumor microenvironment includes CSF1R-expressing supportive monocyte/macrophages that promote tumor cell survival. For chronic lymphocytic leukemia (CLL), these supportive monocyte/macrophages are known as nurse-like cells (NLCs), although the potential effectiveness of selective small-molecule inhibitors of CSF1R against CLL is understudied. Here, we demonstrate the preclinical activity of two inhibitors of CSF1R, GW-2580 and ARRY-382, in primary CLL patient samples. We observed at least 25% of CLL samples showed sub-micromolar sensitivity to CSF1R inhibitors. This sensitivity was observed in samples with varying genetic and clinical backgrounds, although higher white cell count and monocyte cell percentage was associated with increased sensitivity. Depleting CD14-expressing monocytes preferentially decreased viability in samples sensitive to CSF1R inhibitors, and treating samples with CSF1R inhibitors eliminated the presence of NLCs in long-term culture conditions. These results indicate that CSF1R small-molecule inhibitors target CD14-expressing monocytes in the CLL microenvironment, thereby depriving leukemia cells of extrinsic support signals. In addition, significant synergy was observed combining CSF1R inhibitors with idelalisib or ibrutinib, two current CLL therapies that disrupt tumor cell intrinsic B-cell receptor signaling. These findings support the concept of simultaneously targeting supportive NLCs and CLL cells and demonstrate the potential clinical utility of this combination.

Underestimating the effects of spatial heterogeneity due to individual movement and spatial scale: infectious disease as an example

USGS Publications Warehouse

Cross, Paul C.; Caillaud, Damien; Heisey, Dennis M.

2013-01-01

Many ecological and epidemiological studies occur in systems with mobile individuals and heterogeneous landscapes. Using a simulation model, we show that the accuracy of inferring an underlying biological process from observational data depends on movement and spatial scale of the analysis. As an example, we focused on estimating the relationship between host density and pathogen transmission. Observational data can result in highly biased inference about the underlying process when individuals move among sampling areas. Even without sampling error, the effect of host density on disease transmission is underestimated by approximately 50 % when one in ten hosts move among sampling areas per lifetime. Aggregating data across larger regions causes minimal bias when host movement is low, and results in less biased inference when movement rates are high. However, increasing data aggregation reduces the observed spatial variation, which would lead to the misperception that a spatially targeted control effort may not be very effective. In addition, averaging over the local heterogeneity will result in underestimating the importance of spatial covariates. Minimizing the bias due to movement is not just about choosing the best spatial scale for analysis, but also about reducing the error associated with using the sampling location as a proxy for an individual’s spatial history. This error associated with the exposure covariate can be reduced by choosing sampling regions with less movement, including longitudinal information of individuals’ movements, or reducing the window of exposure by using repeated sampling or younger individuals.

Determining the effect of different environmental conditions on Ebola virus viability in clinically relevant specimens.

PubMed

Palyi, Bernadett; Magyar, Nora; Henczko, Judit; Szalai, Balint; Farkas, Agnes; Strecker, Thomas; Takacs, Maria; Kis, Zoltan

2018-03-29

In 2013-2016, West Africa experienced the largest and longest Ebola virus disease outbreak ever documented. The wide geographic spread and magnitude of the outbreak often limited the timely and rapid testing of diagnostic samples from patients with suspected Ebola virus disease, raising questions regarding the optimal storage and shipping conditions of clinically relevant specimens, including EDTA-whole blood, plasma, capillary blood, urine and seminal fluid (associated with sexual transmission of the Ebola virus after recovery from the disease). Therefore, the aim of our study was to identify the extent to which storage temperature and clinical specimen type influence Ebola virus viability. Virus infectivity was determined using a fluorescent focus-forming assay. In our study, we show that Ebola virus was the most stable in EDTA-whole blood and plasma samples, whereas rapid decay of infectivity was observed in simulated capillary blood, urine and semen samples, especially when these samples were stored at higher temperatures. The analysis of variance results demonstrated that both temperature and clinical specimen type have significant effects on virus viability, whereas donor differences were not observed. Repeated freeze and thaw cycles of the samples also had a notable impact on virus viability in EDTA-whole blood and urine. Due to the rapid temperature- and specimen-dependent degradation of the virus observed here, our study highlights the importance of proper clinical sample storage at low temperatures during transportation and laboratory analysis.

Rational Variability in Children's Causal Inferences: The Sampling Hypothesis

ERIC Educational Resources Information Center

Denison, Stephanie; Bonawitz, Elizabeth; Gopnik, Alison; Griffiths, Thomas L.

2013-01-01

We present a proposal--"The Sampling Hypothesis"--suggesting that the variability in young children's responses may be part of a rational strategy for inductive inference. In particular, we argue that young learners may be randomly sampling from the set of possible hypotheses that explain the observed data, producing different hypotheses with…

Analysing designed experiments in distance sampling

Treesearch

Stephen T. Buckland; Robin E. Russell; Brett G. Dickson; Victoria A. Saab; Donal N. Gorman; William M. Block

2009-01-01

Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates...

A Novel, Simplified Scheme for Plastics Identification: "JCE" Classroom Activity 104

ERIC Educational Resources Information Center

Harris, Mary E.; Walker, Barbara

2010-01-01

In this Activity, students identify samples of seven types of recyclable plastic by using a flowchart scheme. The flowchart procedure includes making density comparisons of the plastic samples in water and alcohol and observing physical changes of plastic samples subjected to boiling water temperatures and exposure to acetone. This scheme is…

Serum antileptospiral agglutinins in freshwater turtles from Southern Brazil

PubMed Central

Silva, Éverton F; Seyffert, Núbia; Cerqueira, Gustavo M.; Leihs, Karl P.; Athanazio, Daniel A.; Valente, Ana L. S.; Dellagostin, Odir A.; Brod, Claudiomar S.

2009-01-01

In this study, we observed the presence of antileptospiral agglutinins in freshwater turtles of two urban lakes of Pelotas, Southern Brazil. Forty animals (29 Trachemys dorbigny and 11 Phrynops hilarii) were captured and studied. Attempts to isolate leptospires from blood and urine samples were unsuccessful. Serum samples (titer > 100) reactive to pathogenic strains were observed in 11 animals. These data encourage surveys of pet turtles to evaluate the risk of transmission of pathogenic leptospires to humans. PMID:24031348

Effect of Gamma Radiation on Absorption of Light in Potassium-Aluminoborate Glasses with Additions of Iron Oxide

NASA Astrophysics Data System (ADS)

Ibragimova, E. M.; Salakhitdinov, A. N.; Salakhitdinova, M. K.; Yusupov, A. A.

2018-05-01

The effect of radiation on the absorption of light by potassium-alumina-borate glasses with various concentrations of iron additions and various thicknesses was investigated. It was shown that in contrast to samples of small thickness (1 mm) a bleaching effect was observed in the samples with a thickness of 8 mm. A possible mechanism involving the formation of nanostructured units is proposed for the observed effect.

Perilymph composition in scala tympani of the cochlea: influence of cerebrospinal fluid.

PubMed

Hara, A; Salt, A N; Thalmann, R

1989-11-01

A commonly used technique to obtain cochlear perilymph for analysis has been the aspiration of samples through the round window membrane. The present study has investigated the influence of the volume withdrawn on sample composition in the guinea pig. Samples of less than 200 nl in volume taken through the round window showed relatively high glycine content, comparable to the level found in samples taken from scala vestibuli. If larger volumes are withdrawn, lower glycine levels are observed. This is consistent with cerebrospinal fluid (having a low glycine content) being drawn into scala tympani through the cochlear aqueduct and contaminating the sample. The existence of a concentration difference for glycine between scala tympani perilymph and cerebrospinal fluid suggests the physiologic communication across the cochlear aqueduct is relatively small in this species. The observation of considerable exchange between cerebrospinal fluid and perilymph, as reported in some studies, is more likely to be an artifact of the experimental procedures, rather than of physiologic significance. Alternative sampling procedures have been evaluated which allow larger volumes of uncontaminated scala tympani perilymph to be collected.

Development of improved space sampling strategies for ocean chemical properties: Total carbon dioxide and dissolved nitrate

NASA Technical Reports Server (NTRS)

Goyet, Catherine; Davis, Daniel; Peltzer, Edward T.; Brewer, Peter G.

1995-01-01

Large-scale ocean observing programs such as the Joint Global Ocean Flux Study (JGOFS) and the World Ocean Circulation Experiment (WOCE) today, must face the problem of designing an adequate sampling strategy. For ocean chemical variables, the goals and observing technologies are quite different from ocean physical variables (temperature, salinity, pressure). We have recently acquired data on the ocean CO2 properties on WOCE cruises P16c and P17c that are sufficiently dense to test for sampling redundancy. We use linear and quadratic interpolation methods on the sampled field to investigate what is the minimum number of samples required to define the deep ocean total inorganic carbon (TCO2) field within the limits of experimental accuracy (+/- 4 micromol/kg). Within the limits of current measurements, these lines were oversampled in the deep ocean. Should the precision of the measurement be improved, then a denser sampling pattern may be desirable in the future. This approach rationalizes the efficient use of resources for field work and for estimating gridded (TCO2) fields needed to constrain geochemical models.

M551 metals melting experiment. [space manufacturing of aluminum alloys, tantalum alloys, stainless steels

NASA Technical Reports Server (NTRS)

Li, C. H.; Busch, G.; Creter, C.

1976-01-01

The Metals Melting Skylab Experiment consisted of selectively melting, in sequence, three rotating discs made of aluminum alloy, stainless steel, and tantalum alloy. For comparison, three other discs of the same three materials were similarly melted or welded on the ground. The power source of the melting was an electron beam unit. Results are presented which support the concept that the major difference between ground base and Skylab samples (i.e., large elongated grains in ground base samples versus nearly equiaxed and equal sized grains in Skylab samples) can be explained on the basis of constitutional supercooling, and not on the basis of surface phenomena. Microstructural observations on the weld samples and present explanations for some of these observations are examined. In particular, ripples and their implications to weld solidification were studied. Evidence of pronounced copper segregation in the Skylab A1 weld samples, and the tantalum samples studied, indicates a weld microhardness (and hence strength) that is uniformly higher than the ground base results, which is in agreement with previous predictions. Photographs are shown of the microstructure of the various alloys.

Some physical properties of naturally irradiated fluorite

USGS Publications Warehouse

Berman, Robert

1955-01-01

Five samples of purple fluorite found in association with radioactive, materials, and a synthetic colorless control sample were studied and compared.  Before and after heating, observations were made on specific gravity, index of refraction, unit-cell size, breadth of X-ray diffraction lines, and fluorescence.  The purple samples became colorless on heating above 175° C.  During the process, observations were made on color, thermoluminescence, and differential thermal analysis curves.  There were strong correlations between the various physical properties, and it was found possible to arrange the samples in order of increasing difference in their physical properties from the control sample. This order apparently represents increasing structural damage by radiation; if so, it correlates with decreasing specific gravity, increasing index of refraction, broadening of X-ray lines, and increasingly strong exothermic reactions on annealing. The differences between the samples in index of refraction and X-ray pattern are largely eliminated on annealing.  Annealing begins at 1750 C; thermoluminescence at lower temperatures is due to electrons escaping from the metastable potential traps, not the destruction of those traps which takes place on annealing.

Candidiasis: Prevalence and resistance profiling in a tertiary care hospital of Pakistan.

PubMed

Jamil, Bushra; Mukhtar Bokhari, Mohammad Tauseef; Saeed, Azhar; Mukhtar Bokhari, Mohammad Zahid; Hussain, Zakir; Khalid, Tayyaba; Bokhari, Habib; Imran, Mohammad; Abbasi, Shahid Ahmad

2017-05-01

To determine Candida colonisation/infection in renal transplant patients and to determine the resistance pattern against antifungal drugs. This prospective, observational study was conducted at Al-Sayyed Hospital, Rawalpindi, Pakistan, from January to October 2014, in collaboration with the Microbiology and Public Health Laboratory's, Islamabad campus..The clinical specimens investigated included respiratory tract secretions, blood, urine, high vaginal swab, skin scrapings, and plastic devices samples. Of the 7,850 samples, 164(2.08%) were positive for Candida. Candida albicans were most prevalent as they were found in 114(69%) samples. Besides, 56(34%) of the positive samples were resistant to one or more antifungal agents. Highest resistance was obtained against fluconazole. We found only 5(3.04%) positive samples of Candida glabrata; of them, 3(60%)were resistant. In case of Candida spp, 27(48%) resistance was observed. In Candida albicans, 23(41%) of the samples were found to be resistant. Most of the Candida isolates was recovered from bronchial alveolar lavage. Although Candida albicans remained the main responsible species for Candida infections, but non-albican Candida species are also emerging.

Discrimination of Radix Polygoni Multiflori from different geographical areas by UPLC-QTOF/MS combined with chemometrics.

PubMed

Tang, Jin-Fa; Li, Wei-Xia; Zhang, Fan; Li, Yu-Hui; Cao, Ying-Jie; Zhao, Ya; Li, Xue-Lin; Ma, Zhi-Jie

2017-01-01

Nowadays, Radix Polygoni Multiflori (RPM, Heshouwu in Chinese) from different geographical origins were used in clinic. In order to characterize the chemical profiles of different geographical origins of RPM samples, ultra-high performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF/MS) combined with chemometrics (partial least squared discriminant analysis, PLS‑DA) method was applied in the present study. The chromatography, chemical composition and MS information of RPM samples from 18 geographical origins were acquired and profiled by UPLC-QTOF/MS. The chemical markers contributing the differentiation of RPM samples were observed and characterized by supervised PLS‑DA method of chemometrics. The chemical composition differences of RPM samples derived from 18 different geographical origins were observed. Nine chemical markers were tentatively identified which could be used as specific chemical markers for the differentiation of geographical RPM samples. UPLC-QTOF/MS method coupled with chemometrics analysis has potential to be used for discriminating different geographical TCMs. Results will help to develop strategies for conservation and utilization of RPM samples.

Sandwich-dot enzyme-linked immunosorbent assay for the detection of canine distemper virus

PubMed Central

Li, Zhi; Zhang, Yanlong; Wang, Huiguo; Jin, Jinhua; Li, Wenzhe

2013-01-01

A sandwich-dot enzyme-linked immunosorbent assay (dot ELISA) was developed for the detection of canine distemper virus (CDV). In 56 dogs suspected to have CD the rates of detection of CDV antigen in samples of blood lymphocytes and palpebral conjunctiva by dot ELISA and ELISA were, respectively, 91% (49/54) and 81% (44/54) for the lymphocyte samples and 88% (28/32) and 75% (24/32) for the conjunctival samples. The CDV detection limits were 10 ng/50 μL for dot ELISA and 40 ng/50 μL for ELISA. The reliability of dot ELISA relative to electron microscopy was 96% with 22 samples: all 21 samples in which CDV particles were observed by electron microscopy yielded positive results with dot ELISA; the single sample in which particles were not observed yielded false-positive results with dot ELISA. The results indicate that the dot ELISA developed can serve as a reliable rapid diagnostic test in suspected cases of CD and also be useful for epidemiologic surveillance of the disease. PMID:24124274

Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample

DOEpatents

Maerefat, N.L.; Parmeswar, R.; Brinkmeyer, A.D.; Honarpour, M.

1994-08-23

A system is described for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample. 11 figs.

Occurrence of Toxic Cyanobacterial Blooms in Rio de la Plata Estuary, Argentina: Field Study and Data Analysis

PubMed Central

Giannuzzi, L.; Carvajal, G.; Corradini, M. G.; Araujo Andrade, C.; Echenique, R.; Andrinolo, D.

2012-01-01

Water samples were collected during 3 years (2004–2007) at three sampling sites in the Rio de la Plata estuary. Thirteen biological, physical, and chemical parameters were determined on the water samples. The presence of microcystin-LR in the reservoir samples, and also in domestic water samples, was confirmed and quantified. Microcystin-LR concentration ranged between 0.02 and 8.6 μg.L−1. Principal components analysis was used to identify the factors promoting cyanobacteria growth. The proliferation of cyanobacteria was accompanied by the presence of high total and fecal coliforms bacteria (>1500 MNP/100 mL), temperature ≥25°C, and total phosphorus content ≥1.24 mg·L−1. The observed fluctuating patterns of Microcystis aeruginosa, total coliforms, and Microcystin-LR were also described by probabilistic models based on the log-normal and extreme value distributions. The sampling sites were compared in terms of the distribution parameters and the probability of observing high concentrations for Microcystis aeruginosa, total coliforms, and microcystin-LR concentration. PMID:22523486

Transmission electron microscopy artifacts in characterization of the nanomaterial-cell interactions.

PubMed

Leung, Yu Hang; Guo, Mu Yao; Ma, Angel P Y; Ng, Alan M C; Djurišić, Aleksandra B; Degger, Natalie; Leung, Frederick C C

2017-07-01

We investigated transmission electron microscopy artifacts obtained using standard sample preparation protocols applied to the investigation of Escherichia coli cells exposed to common nanomaterials, such as TiO 2 , Ag, ZnO, and MgO. While the common protocols for some nanomaterials result only in known issues of nanomaterial-independent generation of anomalous deposits due to fixation and staining, for others, there are reactions between the nanomaterial and chemicals used for post-fixation or staining. Only in the case of TiO 2 do we observe only the known issues of nanomaterial-independent generation of anomalous deposits due to exceptional chemical stability of this material. For the other three nanomaterials, different artifacts are observed. For each of those, we identify causes of the observed problems and suggest alternative sample preparation protocols to avoid artifacts arising from the sample preparation, which is essential for correct interpretation of the obtained images and drawing correct conclusions on cell-nanomaterial interactions. Finally, we propose modified sample preparation and characterization protocols for comprehensive and conclusive investigations of nanomaterial-cell interactions using electron microscopy and for obtaining clear and unambiguous revelation whether the nanomaterials studied penetrate the cells or accumulate at the cell membranes. In only the case of MgO and ZnO, the unambiguous presence of Zn and Mg could be observed inside the cells.

Reduction and analysis of VLA maps for 281 radio-loud quasars using the UNLV Cray Y-MP supercomputer

NASA Technical Reports Server (NTRS)

Ding, Ailian; Hintzen, Paul; Weistrop, Donna; Owen, Frazer

1993-01-01

The identification of distorted radio-loud quasars provides a potentially very powerful tool for basic cosmological studies. If large morphological distortions are correlated with membership of the quasars in rich clusters of galaxies, optical observations can be used to identify rich clusters of galaxies at large redshifts. Hintzen, Ulvestad, and Owen (1983, HUO) undertook a VLA A array snapshot survey at 20 cm of 123 radio-loud quasars, and they found that among triple sources in their sample, 17 percent had radio axes which were bent more than 20 deg and 5 percent were bent more than 40 deg. Their subsequent optical observations showed that excess galaxy densities within 30 arcsec of 6 low-redshift distorted quasars were on average 3 times as great as those around undistorted quasars (Hintzen 1984). At least one of the distorted quasars observed, 3C275.1, apparently lies in the first-ranked galaxy at the center of a rich cluster of galaxies (Hintzen and Romanishin, 1986). Although their sample was small, these results indicated that observations of distorted quasars could be used to identify clusters of galaxies at large redshifts. The purpose of this project is to increase the available sample of distorted quasars to allow optical detection of a significant sample of quasar-associated clusters of galaxies at large redshifts.

Observed and perceived parental overprotection in relation to psychosocial adjustment in preadolescents with a physical disability: the mediational role of behavioral autonomy.

PubMed

Holmbeck, Grayson N; Johnson, Sharon Z; Wills, Karen E; McKernon, Wendy; Rose, Brigid; Erklin, Shannon; Kemper, Therese

2002-02-01

The purpose of this study was to tes a mediational model of associations between parental overprotectiveness (OP), behavioral autonomy. and psychosocial adjustment in 68 families with 8- and 9-year-old preadolescents with spipa bifida and a demographically matched sample of 68 families with able-bodied children. Measures included questionnaire and observational assessments of parental OP; parent and child reports of behavioral autonomy; and parent, child, and teacher reports of preadolescent adjustment. On the basis of both questionnaire and observational measures of OP, mothers and fathers of children with spina bifida were significantly more overprotective than their counterparts in the able-bodied sample, although this group difference was partially mediated by children's cognitive ability. Across samples, mothers were more likely to be overprotective than fathers. Both questionnaire and observational measures of parental OP were associated with lower levels of preadolescent decision-making autonomy as well as with parents being less willing to grant autonomy to their offspring in the future. For the questionnaire measure of OP, and only for the spina bifida sample. the mediational model was supported such that parental OP was associated with less behavioral autonomy, which was, in turn, associated with more externalizing problems. Findings are discussed in relation to the literature on parenting, autonomy development, and pediatric psychology.

Genetic structure and inter-generic relationship of closed colony of laboratory rodents based on RAPD markers.

PubMed

Kumar, Mahadeo; Kumar, Sharad

2014-11-01

Molecular genetic analysis was performed using random amplified polymorphic DNA (RAPD) on three commonly used laboratory bred rodent genera viz. mouse (Mus musculus), rat (Rattus norvegicus) and guinea pig (Cavia porcellus) as sampled from the breeding colony maintained at the Animal Facility, CSIR-Indian Institute of Toxicology Research, Lucknow. In this study, 60 samples, 20 from each genus, were analyzed for evaluation of genetic structure of rodent stocks based on polymorphic bands using RAPD markers. Thirty five random primers were assessed for RAPD analysis. Out of 35, only 20 primers generated a total of 56.88% polymorphic bands among mice, rats and guinea pigs. The results revealed significantly variant and distinct fingerprint patterns specific to each of the genus. Within-genera analysis, the highest (89.0%) amount of genetic homogeneity was observed in mice samples and the least (79.3%) were observed in guinea pig samples. The amount of genetic homogeneity was observed very high within all genera. The average genetic diversity index observed was low (0.045) for mice and high (0.094) for guinea pigs. The inter-generic distances were maximum (0.8775) between mice and guinea pigs; and the minimum (0.5143) between rats and mice. The study proved that the RAPD markers are useful as genetic markers for assessment of genetic structure as well as inter-generic variability assessments.

Solvent hold tank sample results for MCU-16-1488-1493 (December 2016), MCU-17-86-88 (January 2017), and MCU-17-119-121 (February 2017): Quarterly Report

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

Fondeur, F. F.; Jones, D. H.

A trend summary of three Solvent Hold Tank (SHT) monthly samples; MCU-16-1488-1493 (December 2016), MCU-17-86-88 (January 2017), and MCU-17-119-121 (February 2017) are reported. Analyses indicate that the modifier (CS-7SB) and the extractant (MaxCalix) concentrations are at their nominal recommended levels (169,000 mg/L and 46,300 mg/L respectively). The suppressor (TiDG) level has decreased to a steady state level of 673 mg/L well above the minimum recommended level (479 mg/L). This analysis confirms the Isopar™ addition to the solvent in January 18, 2017. This analysis also indicates the solvent did not require further additions. Based on the current monthly sample, the levelsmore » of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). No impurities were observed in the Hydrogen Nuclear Magnetic Resonance (HNMR). Another impurity observed in the samples was mercury. Up to 38 ± 8 micrograms of mercury per mL of solvent was detected in these samples (the average of the CV-AA and XRF methods). The higher mercury concentration in the solvent (as determined in the last three monthly samples) is possibly due to the higher mercury concentration in Salt Batches 8 and 9 (Tank 49H) or mixing of previously undisturbed areas of high mercury concentration in Tank 49H. The gamma level (0.21E5 dpm/mL) measured in the February SHT sample was one order of magnitude lower than the gamma levels observed in the December and January SHT samples. The February gamma level is consistent with the solvent being idle (since January 10, 2017). The gamma levels observed in the December and January SHT samples were consistent with previous monthly measurements where the process operated normally. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.« less

Application of Lamendin's adult dental aging technique to a diverse skeletal sample.

PubMed

Prince, Debra A; Ubelaker, Douglas H

2002-01-01

Lamendin et al. (1) proposed a technique to estimate age at death for adults by analyzing single-rooted teeth. They expressed age as a function of two factors: translucency of the tooth root and periodontosis (gingival regression). In their study, they analyzed 306 singled rooted teeth that were extracted at autopsy from 208 individuals of known age at death, all of whom were considered as having a French ancestry. Their sample consisted of 135 males, 73 females, 198 whites, and 10 blacks. The sample ranged in age from 22 to 90 years of age. By using a simple formulae (A = 0.18 x P + 0.42 x T + 25.53, where A = Age in years, P = Periodontosis height x 100/root height, and T = Transparency height x 100/root height), Lamendin et al. were able to estimate age at death with a mean error of +/- 10 years on their working sample and +/- 8.4 years on a forensic control sample. Lamendin found this technique to work well with a French population, but did not test it outside of that sample area. This study tests the accuracy of this adult aging technique on a more diverse skeletal population, the Terry Collection housed at the Smithsonian's National Museum of Natural History. Our sample consists of 400 teeth from 94 black females, 72 white females, 98 black males, and 95 white males, ranging from 25 to 99 years. Lamendin's technique was applied to this sample to test its applicability to a population not of French origin. Providing results from a diverse skeletal population will aid in establishing the validity of this method to be used in forensic cases, its ideal purpose. Our results suggest that Lamendin's method estimates age fairly accurately outside of the French sample yielding a mean error of 8.2 years, standard deviation 6.9 years, and standard error of the mean 0.34 years. In addition, when ancestry and sex are accounted for, the mean errors are reduced for each group (black females, white females, black males, and white males). Lamendin et al. reported an inter-observer error of 9+/-1.8 and 10+/-2 sears from two independent observers. Forty teeth were randomly remeasured from the Terry Collection in order to assess an intra-observer error. From this retest, an intra-observer error of 6.5 years was detected.

Generalizability of causal inference in observational studies under retrospective convenience sampling.

PubMed

Hu, Zonghui; Qin, Jing

2018-05-20

Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are representative of the respective subpopulation, but the proportion of the 2 subpopulations is usually not preserved in the sample data. We show in this work that, under RCS, existing causal effect estimators actually estimate the treatment effect over the sample population instead of the underlying study population. We investigate how to correct existing methods for consistent estimation of the treatment effect over the underlying population. Although RCS is adopted in medical studies for ethical and cost-effective purposes, it also has a big advantage for statistical inference: When the tendency to receive treatment is low in a study population, treatment effect estimators under RCS, with proper correction, are more efficient than their parallels under random sampling. These properties are investigated both theoretically and through numerical demonstration. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

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.

Temperature-dependent quality characteristics of pre-dehydrated cookies: structure, browning, texture, in vitro starch digestibility, and the effect on blood glucose levels in mice.

PubMed

Kawai, Kiyoshi; Matsusaki, Keiko; Hando, Kana; Hagura, Yoshio

2013-11-01

The purpose of this study was to elucidate the physical and biochemical properties of pre-dehydrated cookies baked at various temperatures. Cookie dough was vacuum-dried, and then baked at 120-180°C for 18 min. All samples showed lower spread ratio than non-dehydrated cookie baked at 180°C (control). Browning of the samples baked at 180°C and 160°C was higher than that of the control. In contrast, little browning was observed in the sample baked at 120°C. The fracture force of samples baked at 140°C and 120°C agreed well with the control. From these results, the sample baked at 140°C was employed for subsequent studies. In vitro starch digestibility suggested that the sample baked at 140°C had higher slowly digestible starch content than the control. From postprandial blood glucose levels in mice, it was found that the sample significantly reduced the blood glucose peak observed at 30 min post-administration. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Breakthrough Listen Search for Intelligent Life: Target Selection of Nearby Stars and Galaxies

NASA Astrophysics Data System (ADS)

Isaacson, Howard; Siemion, Andrew P. V.; Marcy, Geoffrey W.; Lebofsky, Matt; Price, Danny C.; MacMahon, David; Croft, Steve; DeBoer, David; Hickish, Jack; Werthimer, Dan; Sheikh, Sofia; Hellbourg, Greg; Enriquez, J. Emilio

2017-05-01

We present the target selection for the Breakthrough Listen search for extraterrestrial intelligence during the first year of observations at the Green Bank Telescope, Parkes Telescope, and Automated Planet Finder. On the way to observing 1,000,000 nearby stars in search of technological signals, we present three main sets of objects we plan to observe in addition to a smaller sample of exotica. We chose the 60 nearest stars, all within 5.1 pc from the Sun. Such nearby stars offer the potential to observe faint radio signals from transmitters that have a power similar to those on Earth. We add a list of 1649 stars drawn from the Hipparcos catalog that span the Hertzprung-Russell diagram, including all spectral types along the main sequence, subgiants, and giant stars. This sample offers diversity and inclusion of all stellar types, but with thoughtful limits and due attention to main sequence stars. Our targets also include 123 nearby galaxies composed of a “morphological-type-complete” sample of the nearest spirals, ellipticals, dwarf spherioidals, and irregulars. While their great distances hamper the detection of technological electromagnetic radiation, galaxies offer the opportunity to observe billions of stars simultaneously and to sample the bright end of the technological luminosity function. We will also use the Green Bank and Parkes telescopes to survey the plane and central bulge of the Milky Way. Finally, the complete target list includes several classes of exotica, including white dwarfs, brown dwarfs, black holes, neutron stars, and asteroids in our solar system.

High-resolution monitoring of marine protists based on an observation strategy integrating automated on-board filtration and molecular analyses

NASA Astrophysics Data System (ADS)

Metfies, Katja; Schroeder, Friedhelm; Hessel, Johanna; Wollschläger, Jochen; Micheller, Sebastian; Wolf, Christian; Kilias, Estelle; Sprong, Pim; Neuhaus, Stefan; Frickenhaus, Stephan; Petersen, Wilhelm

2016-11-01

Information on recent biomass distribution and biogeography of photosynthetic marine protists with adequate temporal and spatial resolution is urgently needed to better understand the consequences of environmental change for marine ecosystems. Here we introduce and review a molecular-based observation strategy for high-resolution assessment of these protists in space and time. It is the result of extensive technology developments, adaptations and evaluations which are documented in a number of different publications, and the results of the recently completed field testing which are introduced in this paper. The observation strategy is organized at four different levels. At level 1, samples are collected at high spatiotemporal resolution using the remotely controlled automated filtration system AUTOFIM. Resulting samples can either be preserved for later laboratory analyses, or directly subjected to molecular surveillance of key species aboard the ship via an automated biosensor system or quantitative polymerase chain reaction (level 2). Preserved samples are analyzed at the next observational levels in the laboratory (levels 3 and 4). At level 3 this involves molecular fingerprinting methods for a quick and reliable overview of differences in protist community composition. Finally, selected samples can be used to generate a detailed analysis of taxonomic protist composition via the latest next generation sequencing technology (NGS) at level 4. An overall integrated dataset of the results based on the different analyses provides comprehensive information on the diversity and biogeography of protists, including all related size classes. At the same time the cost of the observation is optimized with respect to analysis effort and time.

Immunocytometric quantitation of foeto-maternal haemorrhage with the Abbott Cell-Dyn CD4000 haematology analyser.

PubMed

Little, B H; Robson, R; Roemer, B; Scott, C S

2005-02-01

This study evaluated the extended use of a haematology analyser (Abbott Cell-Dyn CD4000) for the immunofluorescent enumeration of foeto-maternal haemorrhage (FMH) with fluorescein isothiocyanate-labelled monoclonal anti-RhD. Method performance was assessed with artificial FMH standards, and a series of 44 clinical samples. Within run precision was <15% (coefficient of variation, CV) for FMH volumes of 3 ml and above, 18.8% at an FMH volume of 2 ml and 31.7% at an FMH volume of 1 ml. Linearity analysis showed excellent agreement (observed FMH% = 0.98x expected FMH% + 0.02), and a close relationship (R(2) = 0.99) between observed and expected FMH percentages. The lower limit of quantification of the CD4000 (SRP-Ret) method with a maximum CV of 15% was 1.6 ml, and the limit of detection was <1 ml. Parallel Kleihauer-Betke test (KBT) assessments of FMH standards showed an overall trend for higher KBT values (observed = 1.25x expected - 0.38). At an FMH level of 4 ml, KBT observer estimates ranged from 0.57 to 11.94 ml with a mean inter-observer CV of 63%. For 44 clinical samples, there was decision point agreement between KBT and SRP-Ret results for 42 samples with an FMH of <2 ml. Analysis in the low FMH range (<1 ml) showed that small volume foetal leaks could be detected with the SRP-Ret method in most of 23 samples with negative KBT results. CD4000 SRP-Ret method performance for FMH determination was similar to that reported for flow cytometry.

THE DETECTION AND STATISTICS OF GIANT ARCS BEHIND CLASH CLUSTERS

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

Xu, Bingxiao; Zheng, Wei; Postman, Marc

We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ andmore » length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift z{sub s} = 1.9 with 33% of the detected arcs having z{sub s} > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c–M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations.« less

Field Geologic Observation and Sample Collection Strategies for Planetary Surface Exploration: Insights from the 2010 Desert RATS Geologist Crewmembers

NASA Technical Reports Server (NTRS)

Hurtado, Jose M., Jr.; Young, Kelsey; Bleacher, Jacob E.; Garry, W. Brent; Rice, James W., Jr.

2012-01-01

Observation is the primary role of all field geologists, and geologic observations put into an evolving conceptual context will be the most important data stream that will be relayed to Earth during a planetary exploration mission. Sample collection is also an important planetary field activity, and its success is closely tied to the quality of contextual observations. To test protocols for doing effective planetary geologic field- work, the Desert RATS(Research and Technology Studies) project deployed two prototype rovers for two weeks of simulated exploratory traverses in the San Francisco volcanic field of northern Arizona. The authors of this paper represent the geologist crew members who participated in the 2010 field test.We document the procedures adopted for Desert RATS 2010 and report on our experiences regarding these protocols. Careful consideration must be made of various issues that impact the interplay between field geologic observations and sample collection, including time management; strategies relatedtoduplicationofsamplesandobservations;logisticalconstraintson the volume and mass of samples and the volume/transfer of data collected; and paradigms for evaluation of mission success. We find that the 2010 field protocols brought to light important aspects of each of these issues, and we recommend best practices and modifications to training and operational protocols to address them. Underlying our recommendations is the recognition that the capacity of the crew to flexibly execute their activities is paramount. Careful design of mission parameters, especially field geologic protocols, is critical for enabling the crews to successfully meet their science objectives.

Biogeochemical tracers of the marine cyanobacterium Trichodesmium

NASA Astrophysics Data System (ADS)

Carpenter, Edward J.; Harvey, H. Rodger; Fry, Brian; Capone, Douglas G.

1997-01-01

We examined the utility of several biogeochemical tracers for following the fate of the planktonic diazotrophic cyanobacterium Trichodesmium in the sea. The presence of a (CIO) fatty acid previously reported was observed in a culture of Trichodesmium but was not found in natural samples. This cyanobacterium had high concentrations of C 14 and C 16 acids, with lesser amounts of several saturated and unsaturated C 18 fatty acids. This composition was similar to that of other marine cyanobacteria. The major hydrocarbon identified was the C 17n-alkane, which was present in all samples from the five stations examined. Sterols common to algae and copepods were observed in many samples along with hopanoids representative of bacteria, suggesting a varied community structure in colonies collected from different stations. We found no unique taxonomic marker of Trichodesmium among the sterols. Measurements of the σ 15N and σ 13C in Trichodesmium samples from the SW Sargasso and NW Caribbean Seas averaged -0.4960 (range from -0.7 to -0.25960) and -12.9%0 (range from -15.2 to -11.9960), respectively, thus confirming previous observations that this cyanobacterial diazotroph has both the lowest σ 15N and highest σ 13C of any marine phytoplankter observed to date. A culture of Trichodesmium grown under diazotrophic conditions had a σ 15N between -1.3 and -3.6960. Our results support the supposition that the relatively low σ 15N and high σ 13C values observed in suspended and sediment-trapped material from some tropical and subtropical seas result from substantial input of C and N by Trichodesmium.

Tools and Technologies Needed for Conducting Planetary Field Geology While On EVA: Insights from the 2010 Desert RATS Geologist Crewmembers

NASA Technical Reports Server (NTRS)

Young, Kelsey; Hurtado, Jose M., Jr.; Bleacher, Jacob E.; Garry, W. Brent; Bleisath, Scott; Buffington, Jesse; Rice, James W., Jr.

2011-01-01

Observation is the primary role of all field geologists, and geologic observations put into an evolving conceptual context will be the most important data stream that will be relayed to Earth during a planetary exploration mission. Sample collection is also an important planetary field activity, and its success is closely tied to the quality of contextual observations. To test protocols for doing effective planetary geologic fieldwork, the Desert RATS (Research and Technology Studies) project deployed two prototype rovers for two weeks of simulated exploratory traverses in the San Francisco volcanic field of northern Arizona. The authors of this paper represent the geologist crewmembers who participated in the 2010 field test. We document the procedures adopted for Desert RATS 2010 and report on our experiences regarding these protocols. Careful consideration must be made of various issues that impact the interplay between field geologic observations and sample collection, including time management; strategies related to duplication of samples and observations; logistical constraints on the volume and mass of samples and the volume/transfer of data collected; and paradigms for evaluation of mission success. We find that the 2010 field protocols brought to light important aspects of each of these issues, and we recommend best practices and modifications to training and operational protocols to address them. Underlying our recommendations is the recognition that the capacity of the crew to "flexibly execute" their activities is paramount. Careful design of mission parameters, especially field geologic protocols, is critical for enabling the crews to successfully meet their science objectives.

Doping effect on ferromagnetism, ferroelectricity and dielectric constant in sol-gel derived Bi1-xNdxFe1-yCoyO3 nanoceramics

NASA Astrophysics Data System (ADS)

Das, Sananda; Sahoo, R. C.; Bera, K. P.; Nath, T. K.

2018-04-01

Doping at the post-transition metal site by trivalent rare-earth ions and 3d transition metal site by transition metal ions in perovskite lattice has observed a variety of magnetic and electronic orders with spatially correlated charge, spin and orbital degrees of freedom. Here, we report large ferromagnetism and enhanced dielectric constant (at ∼100 Hz) in chemically synthesized single phase multiferroic Bi1-xNdxFe1-yCoyO3 (x = 0, 0.10; y = 0, 0.10) nanoparticles (average particles size ∼45 nm). We have also examined the ferroelectric nature of our chemically synthesized samples. The Rietveld refinement of the XRD data reveals the structural symmetry breaking from distorted rhombohedral R3c structure of BiFeO3 to the triclinic P1 structure in Bi0.9Nd0.1Fe0.9Co0.1O3 (BNFCO) without having any iron rich impurity phase. The magnetization in these nanoceramics most likely originates from the coexistence of mixed valence states of Fe ion (Fe2+ and Fe3+). A high room temperature dielectric constant (∼1050) has been observed at 100 Hz of BNFCO sample. The frequency dependent anomalies near Neel temperature of antiferromagnet in temperature variation of dielectric study have been observed for all the doped and co-doped samples exhibiting typical characteristic of relaxor ferroelectrics. A spectacular enhancement of remanent magnetization MR (∼7.2 emu/gm) and noticeably large coercivity HC (∼17.4 kOe) at 5 K have been observed in this BNFCO sample. Such emergence of ferromagnetic ordering indicates the canting of the surface spins at the surface boundaries because of the reduction of particle size in nanodimension. We have also observed P-E hysteresis loops with a remanent polarization of 26 μC/cm2 and coercive field of 5.6 kV/cm of this sample at room temperature. From impedance spectroscopy study the estimated activation energy of 0.41 eV suggests the semiconducting nature of our nanoceramic BNCFO sample.

Behavior of graphite under heat load and in contact with a hydrogen plasma

NASA Astrophysics Data System (ADS)

Bohdansky, J.; Croessmann, C. D.; Linke, J.; McDonald, J. M.; Morse, D. H.; Pontau, A. E.; Watson, R. D.; Whitley, J. B.; Goebel, D. M.; Hirooka, Y.; Leung, K.; Conn, R. W.; Roth, J.; Ottenberger, W.; Kotzlowski, H. E.

1987-05-01

Graphite is extensively used in large tokamaks today. In these machines the material is exposed to vacuum, to intense heat loads, and to the edge plasma. The use of graphite in such machines, therefore, depends on the outgassing behavior, the heat shock resistance, and thermochemical properties in a hydrogen plasma. Investigations of these properties made at different laboratories are described here. Experiments conducted at Sandia National Laboratories (SNL), Livermore, and the Max-Planck-Institut für Plasmaphysik (IPP) in Garching showed that the outgassing behavior of fine-grain reactor-grade graphite and carbon fiber composites depends on the pretreatment (manufacturing and/or storage). However, after proper outgassing the samples tested behave similarly in the case of fine-grain graphite, but the outgassing remains high for the carbon fiber composites. Heat shock tests have been made with the Electron Beam Test System (EBTS) at SNL, Albuquerque. Directly cooled graphite samples (FE 159 graphite brazed onto Mo tubes) showed no failure at a heat load of 700 W/cm 2, 20 s; or 10 kW, 1 s. Thermal erosion due to sublimination and particle emission from the graphite surface was observed. This effect is related to the surface temperature and becomes significant at temperatures above 2500°K. Fourteen different types of graphite were tested; the main differences among these samples were the different surface temperatures obtained under the same heating conditions. Cracking due to heat shocks was observed in some of the samples, but none of the carbon fiber composites failed. Thermochemical properties have been tested in the PISCES plasma generator at UCLA for ion energies of around 100 eV. The formation of C-H compounds was observed spectroscopically at sample temperatures of around 600°C. However, this chemical reaction did not lead to erosion as observed in beam experiments but to a drastic change of the surface structure due to redeposition. Carbon-hydrogen lines were still observed at sample temperatures of around 100°C. Under these conditions the erosion yield is high and in agreement with those measured in beam experiments.

Quantum oscillations and interference effects in strained n- and p-type modulation doped GaInNAs/GaAs quantum wells

NASA Astrophysics Data System (ADS)

Sarcan, F.; Nutku, F.; Donmez, O.; Kuruoglu, F.; Mutlu, S.; Erol, A.; Yildirim, S.; Arikan, M. C.

2015-08-01

We have performed magnetoresistance measurements on n- and p-type modulation doped GaInNAs/GaAs quantum well (QW) structures in both the weak (B  < 0.08 T) and the high magnetic field (up to 18 T) at 75 mK and 6 K. We observe that the quantum oscillations in {ρxx} and quantum Hall effect (QHE) plateaus in {ρxy} are affected from the presence of the nitrogen in the III-V lattice. The enhancement of N-related scatterings and electron effective mass with increasing nitrogen causes lower electron mobility and higher two-dimensional (2D) electron density, leading to suppressed QHE plateaus in {ρxy} up to 7 T at 6 K. The Shubnikov de Haas (SdH) oscillations develop at lower magnetic fields for higher mobility samples at 6 K and the amplitude of SdH oscillations decreases with increasing nitrogen composition. The well-pronounced QHE plateaus are observed at 75 mK and at higher magnetic fields up to 18 T, for the p-type sample. For n-type samples, the observed anomalies in the characteristic of QHE is attributed the nitrogen-related disorders and overlapping of fluctuating Landau levels. The low magnetic field measurements at 75 mK reveal that the n-type samples exhibit weak antilocalization, whereas weak localization is observed for the p-type sample. The observation of weak antilocalization is an indication of strong electron spin-orbit interactions. The low field magnetoresistance traces are used to extract the spin coherence, phase coherence and elastic scattering times as well Rashba parameters and spin-splitting energy. The calculated Rashba parameters for nitrogen containing samples reveal that the nitrogen composition is a significant parameter to determine the degree of the spin-orbit interactions. Consequently, GaInNAs-based QW structures with various nitrogen compositions can be beneficial to adjust the spin-orbit coupling strength and may be used as a candidate for spintronics applications.

Direct Observations of ULF and Whistler-Mode Chorus Modulation of 500eV EDI Electrons by MMS

NASA Astrophysics Data System (ADS)

Paulson, K. W.; Argall, M. R.; Ahmadi, N.; Torbert, R. B.; Le Contel, O.; Ergun, R.; Khotyaintsev, Y. V.; Strangeway, R. J.; Magnes, W.; Russell, C. T.

2016-12-01

We present here direct observations of chorus-wave modulated field-aligned 500 eV electrons using the Electron Drift Instrument (EDI) on board the Magnetospheric Multiscale mission. These periods of wave activity were additionally observed to be modulated by Pc5-frequency magnetic perturbations, some of which have been identified as drifting mirror-mode structures. The spacecraft encountered these mirror-mode structures just inside of the duskside magnetopause. Using the high sampling rate provided by EDI in burst sampling mode, we are able to observe the individual count fluctuations of field-aligned electrons in this region up to 512 Hz. We use the multiple look directions of EDI to generate both pitch angle and gyrophase plots of the fluctuating counts. Our observations often show unidirectional flow of these modulated electrons along the background field, and in some cases demonstrate gyrophase bunching in the wave region.

Neutron irradiation effects in Fe and Fe-Cr at 300 °C

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

Chen, Wei-Ying; Miao, Yinbin; Gan, Jian

2016-06-01

Fe and Fe-Cr (Cr = 10–16 at.%) specimens were neutron-irradiated at 300 °C to 0.01, 0.1 and 1 dpa. The TEM observations indicated that the Cr significantly reduced the mobility of dislocation loops and suppressed vacancy clustering, leading to distinct damage microstructures between Fe and Fe-Cr. Irradiation-induced dislocation loops in Fe were heterogeneously observed in the vicinity of grown-in dislocations, whereas the loop distribution observed in Fe-Cr is much more uniform. Voids were observed in the irradiated Fe samples, but not in irradiated Fe-Cr samples. Increasing Cr content in Fe-Cr results in a higher density, and a smaller size ofmore » irradiation-induced dislocation loops. Orowan mechanism was used to correlate the observed microstructure and hardening, which showed that the hardening in Fe-Cr can be attributed to the formation of dislocation loops and α' precipitates.« less

Protocol for monitoring forest-nesting birds in National Park Service parks

USGS Publications Warehouse

Dawson, Deanna K.; Efford, Murray G.

2013-01-01

These documents detail the protocol for monitoring forest-nesting birds in National Park Service parks in the National Capital Region Network (NCRN). In the first year of sampling, counts of birds should be made at 384 points on the NCRN spatially randomized grid, developed to sample terrestrial resources. Sampling should begin on or about May 20 and continue into early July; on each day the sampling period begins at sunrise and ends five hours later. Each point should be counted twice, once in the first half of the field season and once in the second half, with visits made by different observers, balancing the within-season coverage of points and their spatial coverage by observers, and allowing observer differences to be tested. Three observers, skilled in identifying birds of the region by sight and sound and with previous experience in conducting timed counts of birds, will be needed for this effort. Observers should be randomly assigned to ‘routes’ consisting of eight points, in close proximity and, ideally, in similar habitat, that can be covered in one morning. Counts are 10 minutes in length, subdivided into four 2.5-min intervals. Within each time interval, new birds (i.e., those not already detected) are recorded as within or beyond 50 m of the point, based on where first detected. Binomial distance methods are used to calculate annual estimates of density for species. The data are also amenable to estimation of abundance and detection probability via the removal method. Generalized linear models can be used to assess between-year changes in density estimates or unadjusted count data. This level of sampling is expected to be sufficient to detect a 50% decline in 10 years for approximately 50 bird species, including 14 of 19 species that are priorities for conservation efforts, if analyses are based on unadjusted count data, and for 30 species (6 priority species) if analyses are based on density estimates. The estimates of required sample sizes are based on the mean number of individuals detected per 10 minutes in available data from surveys in three NCRN parks. Once network-wide data from the first year of sampling are available, this and other aspects of the protocol should be re-assessed, and changes made as desired or necessary before the start of the second field season. Thereafter, changes should not be made to the field methods, and sampling should be conducted annually for at least ten years. NCRN staff should keep apprised of new analytical methods developed for analysis of point-count data.

Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste

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

Fiskum, S.K.; Bredt, P.R.; Campbell, J.A.

2000-10-17

Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids.