extremely small samples: Topics by Science.gov

Sample records for extremely small samples

Using the Student's "t"-Test with Extremely Small Sample Sizes

ERIC Educational Resources Information Center

de Winter, J. C .F.

2013-01-01

Researchers occasionally have to work with an extremely small sample size, defined herein as "N" less than or equal to 5. Some methodologists have cautioned against using the "t"-test when the sample size is extremely small, whereas others have suggested that using the "t"-test is feasible in such a case. The present…
Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)

NASA Astrophysics Data System (ADS)

Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

2000-03-01

Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this technique are a reduction in reagents, higher sensitivity, minimal preparation of complex samples such as blood, real-time calibration, and extremely rapid analysis.
Cultural definitions of elder maltreatment in Portugal.

PubMed

Mercurio, Andrea E; Nyborn, Justin

2006-01-01

A small convenience sample of 34 participants (17 males, 17 females) from the Portuguese islands of the Azores and Madeira were asked to provide examples of how extreme, moderate, and mild maltreatment towards an elder would be defined in their culture and society. Neglect, especially psychological neglect, physical maltreatment, and psychological maltreatment were the most frequently reported types of maltreatment. References to neglect and physical maltreatment appeared most often as examples of extreme maltreatment. In general, men were somewhat more likely than women to provide examples of physical aggression in their examples of maltreatment. As examples of extreme maltreatment, females provided significantly more examples of abandonment than males. Although interpretations of the findings must be cautious because of the small sample size and limited statistical power, the study illustrates a procedure for assessing constructs of elder mistreatment in a way that attends to respondents' own constructions of the phenomenon.
Topological Analysis and Gaussian Decision Tree: Effective Representation and Classification of Biosignals of Small Sample Size.

PubMed

Zhang, Zhifei; Song, Yang; Cui, Haochen; Wu, Jayne; Schwartz, Fernando; Qi, Hairong

2017-09-01

Bucking the trend of big data, in microdevice engineering, small sample size is common, especially when the device is still at the proof-of-concept stage. The small sample size, small interclass variation, and large intraclass variation, have brought biosignal analysis new challenges. Novel representation and classification approaches need to be developed to effectively recognize targets of interests with the absence of a large training set. Moving away from the traditional signal analysis in the spatiotemporal domain, we exploit the biosignal representation in the topological domain that would reveal the intrinsic structure of point clouds generated from the biosignal. Additionally, we propose a Gaussian-based decision tree (GDT), which can efficiently classify the biosignals even when the sample size is extremely small. This study is motivated by the application of mastitis detection using low-voltage alternating current electrokinetics (ACEK) where five categories of bisignals need to be recognized with only two samples in each class. Experimental results demonstrate the robustness of the topological features as well as the advantage of GDT over some conventional classifiers in handling small dataset. Our method reduces the voltage of ACEK to a safe level and still yields high-fidelity results with a short assay time. This paper makes two distinctive contributions to the field of biosignal analysis, including performing signal processing in the topological domain and handling extremely small dataset. Currently, there have been no related works that can efficiently tackle the dilemma between avoiding electrochemical reaction and accelerating assay process using ACEK.
Applying Incremental Sampling Methodology to Soils Containing Heterogeneously Distributed Metallic Residues to Improve Risk Analysis.

PubMed

Clausen, J L; Georgian, T; Gardner, K H; Douglas, T A

2018-01-01

This study compares conventional grab sampling to incremental sampling methodology (ISM) to characterize metal contamination at a military small-arms-range. Grab sample results had large variances, positively skewed non-normal distributions, extreme outliers, and poor agreement between duplicate samples even when samples were co-located within tens of centimeters of each other. The extreme outliers strongly influenced the grab sample means for the primary contaminants lead (Pb) and antinomy (Sb). In contrast, median and mean metal concentrations were similar for the ISM samples. ISM significantly reduced measurement uncertainty of estimates of the mean, increasing data quality (e.g., for environmental risk assessments) with fewer samples (e.g., decreasing total project costs). Based on Monte Carlo resampling simulations, grab sampling resulted in highly variable means and upper confidence limits of the mean relative to ISM.
Regularised extreme learning machine with misclassification cost and rejection cost for gene expression data classification.

PubMed

Lu, Huijuan; Wei, Shasha; Zhou, Zili; Miao, Yanzi; Lu, Yi

2015-01-01

The main purpose of traditional classification algorithms on bioinformatics application is to acquire better classification accuracy. However, these algorithms cannot meet the requirement that minimises the average misclassification cost. In this paper, a new algorithm of cost-sensitive regularised extreme learning machine (CS-RELM) was proposed by using probability estimation and misclassification cost to reconstruct the classification results. By improving the classification accuracy of a group of small sample which higher misclassification cost, the new CS-RELM can minimise the classification cost. The 'rejection cost' was integrated into CS-RELM algorithm to further reduce the average misclassification cost. By using Colon Tumour dataset and SRBCT (Small Round Blue Cells Tumour) dataset, CS-RELM was compared with other cost-sensitive algorithms such as extreme learning machine (ELM), cost-sensitive extreme learning machine, regularised extreme learning machine, cost-sensitive support vector machine (SVM). The results of experiments show that CS-RELM with embedded rejection cost could reduce the average cost of misclassification and made more credible classification decision than others.
Optimizing the triple-axis spectrometer PANDA at the MLZ for small samples and complex sample environment conditions

NASA Astrophysics Data System (ADS)

Utschick, C.; Skoulatos, M.; Schneidewind, A.; Böni, P.

2016-11-01

The cold-neutron triple-axis spectrometer PANDA at the neutron source FRM II has been serving an international user community studying condensed matter physics problems. We report on a new setup, improving the signal-to-noise ratio for small samples and pressure cell setups. Analytical and numerical Monte Carlo methods are used for the optimization of elliptic and parabolic focusing guides. They are placed between the monochromator and sample positions, and the flux at the sample is compared to the one achieved by standard monochromator focusing techniques. A 25 times smaller spot size is achieved, associated with a factor of 2 increased intensity, within the same divergence limits, ± 2 ° . This optional neutron focusing guide shall establish a top-class spectrometer for studying novel exotic properties of matter in combination with more stringent sample environment conditions such as extreme pressures associated with small sample sizes.
Improving power and robustness for detecting genetic association with extreme-value sampling design.

PubMed

Chen, Hua Yun; Li, Mingyao

2011-12-01

Extreme-value sampling design that samples subjects with extremely large or small quantitative trait values is commonly used in genetic association studies. Samples in such designs are often treated as "cases" and "controls" and analyzed using logistic regression. Such a case-control analysis ignores the potential dose-response relationship between the quantitative trait and the underlying trait locus and thus may lead to loss of power in detecting genetic association. An alternative approach to analyzing such data is to model the dose-response relationship by a linear regression model. However, parameter estimation from this model can be biased, which may lead to inflated type I errors. We propose a robust and efficient approach that takes into consideration of both the biased sampling design and the potential dose-response relationship. Extensive simulations demonstrate that the proposed method is more powerful than the traditional logistic regression analysis and is more robust than the linear regression analysis. We applied our method to the analysis of a candidate gene association study on high-density lipoprotein cholesterol (HDL-C) which includes study subjects with extremely high or low HDL-C levels. Using our method, we identified several SNPs showing a stronger evidence of association with HDL-C than the traditional case-control logistic regression analysis. Our results suggest that it is important to appropriately model the quantitative traits and to adjust for the biased sampling when dose-response relationship exists in extreme-value sampling designs. © 2011 Wiley Periodicals, Inc.
Biomedical imaging with THz waves

NASA Astrophysics Data System (ADS)

Nguyen, Andrew

2010-03-01

We discuss biomedical imaging using radio waves operating in the terahertz (THz) range between 300 GHz to 3 THz. Particularly, we present the concept for two THz imaging systems. One system employs single antenna, transmitter and receiver operating over multi-THz-frequency simultaneously for sensing and imaging small areas of the human body or biological samples. Another system consists of multiple antennas, a transmitter, and multiple receivers operating over multi-THz-frequency capable of sensing and imaging simultaneously the whole body or large biological samples. Using THz waves for biomedical imaging promises unique and substantial medical benefits including extremely small medical devices, extraordinarily fine spatial resolution, and excellent contrast between images of diseased and healthy tissues. THz imaging is extremely attractive for detection of cancer in the early stages, sensing and imaging of tissues near the skin, and study of disease and its growth versus time.
Incorporating Biological Knowledge into Evaluation of Casual Regulatory Hypothesis

NASA Technical Reports Server (NTRS)

Chrisman, Lonnie; Langley, Pat; Bay, Stephen; Pohorille, Andrew; DeVincenzi, D. (Technical Monitor)

2002-01-01

Biological data can be scarce and costly to obtain. The small number of samples available typically limits statistical power and makes reliable inference of causal relations extremely difficult. However, we argue that statistical power can be increased substantially by incorporating prior knowledge and data from diverse sources. We present a Bayesian framework that combines information from different sources and we show empirically that this lets one make correct causal inferences with small sample sizes that otherwise would be impossible.
Demonstration/Validation of Incremental Sampling at Two Diverse Military Ranges and Development of an Incremental Sampling Tool

DTIC Science & Technology

2010-06-01

Sampling (MIS)? • Technique of combining many increments of soil from a number of points within exposure area • Developed by Enviro Stat (Trademarked...Demonstrating a reliable soil sampling strategy to accurately characterize contaminant concentrations in spatially extreme and heterogeneous...into a set of decision (exposure) units • One or several discrete or small- scale composite soil samples collected to represent each decision unit
Sequencing small genomic targets with high efficiency and extreme accuracy

PubMed Central

Schmitt, Michael W.; Fox, Edward J.; Prindle, Marc J.; Reid-Bayliss, Kate S.; True, Lawrence D.; Radich, Jerald P.; Loeb, Lawrence A.

2015-01-01

The detection of minority variants in mixed samples demands methods for enrichment and accurate sequencing of small genomic intervals. We describe an efficient approach based on sequential rounds of hybridization with biotinylated oligonucleotides, enabling more than one-million fold enrichment of genomic regions of interest. In conjunction with error correcting double-stranded molecular tags, our approach enables the quantification of mutations in individual DNA molecules. PMID:25849638
Fiber Bragg Grating Dilatometry in Extreme Magnetic Field and Cryogenic Conditions

PubMed Central

Corvalán Moya, Carolina; Weickert, Franziska; Zapf, Vivien; Balakirev, Fedor F.; Wartenbe, Mark; Rosa, Priscila F. S.; Betts, Jonathan B.; Crooker, Scott A.; Daou, Ramzy

2017-01-01

In this work, we review single mode SiO2 fiber Bragg grating techniques for dilatometry studies of small single-crystalline samples in the extreme environments of very high, continuous, and pulsed magnetic fields of up to 150 T and at cryogenic temperatures down to <1 K. Distinct millimeter-long materials are measured as part of the technique development, including metallic, insulating, and radioactive compounds. Experimental strategies are discussed for the observation and analysis of the related thermal expansion and magnetostriction of materials, which can achieve a strain sensitivity (ΔL/L) as low as a few parts in one hundred million (≈10−8). The impact of experimental artifacts, such as those originating in the temperature dependence of the fiber’s index of diffraction, light polarization rotation in magnetic fields, and reduced strain transfer from millimeter-long specimens, is analyzed quantitatively using analytic models available in the literature. We compare the experimental results with model predictions in the small-sample limit, and discuss the uncovered discrepancies. PMID:29117137
Fiber Bragg Grating Dilatometry in Extreme Magnetic Field and Cryogenic Conditions.

PubMed

Jaime, Marcelo; Corvalán Moya, Carolina; Weickert, Franziska; Zapf, Vivien; Balakirev, Fedor F; Wartenbe, Mark; Rosa, Priscila F S; Betts, Jonathan B; Rodriguez, George; Crooker, Scott A; Daou, Ramzy

2017-11-08

In this work, we review single mode SiO₂ fiber Bragg grating techniques for dilatometry studies of small single-crystalline samples in the extreme environments of very high, continuous, and pulsed magnetic fields of up to 150 T and at cryogenic temperatures down to <1 K. Distinct millimeter-long materials are measured as part of the technique development, including metallic, insulating, and radioactive compounds. Experimental strategies are discussed for the observation and analysis of the related thermal expansion and magnetostriction of materials, which can achieve a strain sensitivity ( ΔL/L ) as low as a few parts in one hundred million (≈10 -8 ). The impact of experimental artifacts, such as those originating in the temperature dependence of the fiber's index of diffraction, light polarization rotation in magnetic fields, and reduced strain transfer from millimeter-long specimens, is analyzed quantitatively using analytic models available in the literature. We compare the experimental results with model predictions in the small-sample limit, and discuss the uncovered discrepancies.
Fiber Bragg Grating Dilatometry in Extreme Magnetic Field and Cryogenic Conditions

DOE PAGES

Jaime, Marcelo; Corvalán Moya, Carolina; Weickert, Franziska; ...

2017-11-08

In this work, we review single mode SiO 2 fiber Bragg grating techniques for dilatometry studies of small single-crystalline samples in the extreme environments of very high, continuous, and pulsed magnetic fields of up to 150 T and at cryogenic temperatures down to <1 K. Distinct millimeter-long materials are measured as part of the technique development, including metallic, insulating, and radioactive compounds. Experimental strategies are discussed for the observation and analysis of the related thermal expansion and magnetostriction of materials, which can achieve a strain sensitivity (ΔL/L) as low as a few parts in one hundred million (≈10 -8). Themore » impact of experimental artifacts, such as those originating in the temperature dependence of the fiber’s index of diffraction, light polarization rotation in magnetic fields, and reduced strain transfer from millimeter-long specimens, is analyzed quantitatively using analytic models available in the literature. We compare the experimental results with model predictions in the small-sample limit, and discuss the uncovered discrepancies.« less
Printing Proteins as Microarrays for High-Throughput Function Determination

NASA Astrophysics Data System (ADS)

MacBeath, Gavin; Schreiber, Stuart L.

2000-09-01

Systematic efforts are currently under way to construct defined sets of cloned genes for high-throughput expression and purification of recombinant proteins. To facilitate subsequent studies of protein function, we have developed miniaturized assays that accommodate extremely low sample volumes and enable the rapid, simultaneous processing of thousands of proteins. A high-precision robot designed to manufacture complementary DNA microarrays was used to spot proteins onto chemically derivatized glass slides at extremely high spatial densities. The proteins attached covalently to the slide surface yet retained their ability to interact specifically with other proteins, or with small molecules, in solution. Three applications for protein microarrays were demonstrated: screening for protein-protein interactions, identifying the substrates of protein kinases, and identifying the protein targets of small molecules.
Calculating p-values and their significances with the Energy Test for large datasets

NASA Astrophysics Data System (ADS)

Barter, W.; Burr, C.; Parkes, C.

2018-04-01

The energy test method is a multi-dimensional test of whether two samples are consistent with arising from the same underlying population, through the calculation of a single test statistic (called the T-value). The method has recently been used in particle physics to search for samples that differ due to CP violation. The generalised extreme value function has previously been used to describe the distribution of T-values under the null hypothesis that the two samples are drawn from the same underlying population. We show that, in a simple test case, the distribution is not sufficiently well described by the generalised extreme value function. We present a new method, where the distribution of T-values under the null hypothesis when comparing two large samples can be found by scaling the distribution found when comparing small samples drawn from the same population. This method can then be used to quickly calculate the p-values associated with the results of the test.
Enhanced Cumulative Sum Charts for Monitoring Process Dispersion

PubMed Central

Abujiya, Mu’azu Ramat; Riaz, Muhammad; Lee, Muhammad Hisyam

2015-01-01

The cumulative sum (CUSUM) control chart is widely used in industry for the detection of small and moderate shifts in process location and dispersion. For efficient monitoring of process variability, we present several CUSUM control charts for monitoring changes in standard deviation of a normal process. The newly developed control charts based on well-structured sampling techniques - extreme ranked set sampling, extreme double ranked set sampling and double extreme ranked set sampling, have significantly enhanced CUSUM chart ability to detect a wide range of shifts in process variability. The relative performances of the proposed CUSUM scale charts are evaluated in terms of the average run length (ARL) and standard deviation of run length, for point shift in variability. Moreover, for overall performance, we implore the use of the average ratio ARL and average extra quadratic loss. A comparison of the proposed CUSUM control charts with the classical CUSUM R chart, the classical CUSUM S chart, the fast initial response (FIR) CUSUM R chart, the FIR CUSUM S chart, the ranked set sampling (RSS) based CUSUM R chart and the RSS based CUSUM S chart, among others, are presented. An illustrative example using real dataset is given to demonstrate the practicability of the application of the proposed schemes. PMID:25901356
Can quantile mapping improve precipitation extremes from regional climate models?

NASA Astrophysics Data System (ADS)

Tani, Satyanarayana; Gobiet, Andreas

2015-04-01

The ability of quantile mapping to accurately bias correct regard to precipitation extremes is investigated in this study. We developed new methods by extending standard quantile mapping (QMα) to improve the quality of bias corrected extreme precipitation events as simulated by regional climate model (RCM) output. The new QM version (QMβ) was developed by combining parametric and nonparametric bias correction methods. The new nonparametric method is tested with and without a controlling shape parameter (Qmβ1 and Qmβ0, respectively). Bias corrections are applied on hindcast simulations for a small ensemble of RCMs at six different locations over Europe. We examined the quality of the extremes through split sample and cross validation approaches of these three bias correction methods. This split-sample approach mimics the application to future climate scenarios. A cross validation framework with particular focus on new extremes was developed. Error characteristics, q-q plots and Mean Absolute Error (MAEx) skill scores are used for evaluation. We demonstrate the unstable behaviour of correction function at higher quantiles with QMα, whereas the correction functions with for QMβ0 and QMβ1 are smoother, with QMβ1 providing the most reasonable correction values. The result from q-q plots demonstrates that, all bias correction methods are capable of producing new extremes but QMβ1 reproduces new extremes with low biases in all seasons compared to QMα, QMβ0. Our results clearly demonstrate the inherent limitations of empirical bias correction methods employed for extremes, particularly new extremes, and our findings reveals that the new bias correction method (Qmß1) produces more reliable climate scenarios for new extremes. These findings present a methodology that can better capture future extreme precipitation events, which is necessary to improve regional climate change impact studies.
Collisions of Terrestrial Worlds: The Occurrence of Extreme Mid-infrared Excesses around Low-mass Field Stars

NASA Astrophysics Data System (ADS)

Theissen, Christopher A.; West, Andrew A.

2017-04-01

We present the results of an investigation into the occurrence and properties (stellar age and mass trends) of low-mass field stars exhibiting extreme mid-infrared (MIR) excesses ({L}{IR}/{L}* ≳ 0.01). Stars for the analysis were initially selected from the Motion Verified Red Stars (MoVeRS) catalog of photometric stars with Sloan Digital Sky Survey, 2MASS, and WISE photometry and significant proper motions. We identify 584 stars exhibiting extreme MIR excesses, selected based on an empirical relationship for main-sequence W1-W3 colors. For a small subset of the sample, we show, using spectroscopic tracers of stellar age (Hα and Li I) and luminosity class, that the parent sample is most likely comprised of field dwarfs (≳ 1 Gyr). We also develop the Low-mass Kinematics (LoKi) galactic model to estimate the completeness of the extreme MIR excess sample. Using Galactic height as a proxy for stellar age, the completeness-corrected analysis indicates a distinct age dependence for field stars exhibiting extreme MIR excesses. We also find a trend with stellar mass (using r - z color as a proxy). Our findings are consistent with the detected extreme MIR excesses originating from dust created in a short-lived collisional cascade (≲100,000 years) during a giant impact between two large planetismals or terrestrial planets. These stars with extreme MIR excesses also provide support for planetary collisions being the dominant mechanism in creating the observed Kepler dichotomy (the need for more than a single mode, typically two, to explain the variety of planetary system architectures Kepler has observed), rather than different formation mechanisms.

An interface for the direct coupling of small liquid samples to AMS

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

Ognibene, T. J.; Thomas, A. T.; Daley, P. F.

We describe the moving wire interface attached to the 1-MV AMS system at LLNL’s Center for Accelerator Mass Spectrometry for the analysis of nonvolatile liquid samples as either discrete drops or from the direct output of biochemical separatory instrumentation, such as high-performance liquid chromatography (HPLC). Discrete samples containing at least a few 10 s of nanograms of carbon and as little as 50 zmol 14C can be measured with a 3–5% precision in a few minutes. The dynamic range of our system spans approximately 3 orders in magnitude. Sample to sample memory is minimized by the use of fresh targetsmore » for each discrete sample or by minimizing the amount of carbon present in a peak generated by an HPLC containing a significant amount of 14C. As a result, liquid sample AMS provides a new technology to expand our biomedical AMS program by enabling the capability to measure low-level biochemicals in extremely small samples that would otherwise be inaccessible.« less
An interface for the direct coupling of small liquid samples to AMS

DOE PAGES

Ognibene, T. J.; Thomas, A. T.; Daley, P. F.; ...

2015-05-28

We describe the moving wire interface attached to the 1-MV AMS system at LLNL’s Center for Accelerator Mass Spectrometry for the analysis of nonvolatile liquid samples as either discrete drops or from the direct output of biochemical separatory instrumentation, such as high-performance liquid chromatography (HPLC). Discrete samples containing at least a few 10 s of nanograms of carbon and as little as 50 zmol 14C can be measured with a 3–5% precision in a few minutes. The dynamic range of our system spans approximately 3 orders in magnitude. Sample to sample memory is minimized by the use of fresh targetsmore » for each discrete sample or by minimizing the amount of carbon present in a peak generated by an HPLC containing a significant amount of 14C. As a result, liquid sample AMS provides a new technology to expand our biomedical AMS program by enabling the capability to measure low-level biochemicals in extremely small samples that would otherwise be inaccessible.« less
Design and Manufacturing of Extremely Low Mass Flight Systems

NASA Technical Reports Server (NTRS)

Johnson, Michael R.

2002-01-01

Extremely small flight systems pose some unusual design and manufacturing challenges. The small size of the components that make up the system generally must be built with extremely tight tolerances to maintain the functionality of the assembled item. Additionally, the total mass of the system is extremely sensitive to what would be considered small perturbations in a larger flight system. The MUSES C mission, designed, built, and operated by Japan, has a small rover provided by NASA that falls into this small flight system category. This NASA-provided rover is used as a case study of an extremely small flight system design. The issues that were encountered with the rover portion of the MUSES C program are discussed and conclusions about the recommended mass margins at different stages of a small flight system project are presented.
Nanoparticle functionalised small-core suspended-core fibre - a novel platform for efficient sensing.

PubMed

Doherty, Brenda; Csáki, Andrea; Thiele, Matthias; Zeisberger, Matthias; Schwuchow, Anka; Kobelke, Jens; Fritzsche, Wolfgang; Schmidt, Markus A

2017-02-01

Detecting small quantities of specific target molecules is of major importance within bioanalytics for efficient disease diagnostics. One promising sensing approach relies on combining plasmonically-active waveguides with microfluidics yielding an easy-to-use sensing platform. Here we introduce suspended-core fibres containing immobilised plasmonic nanoparticles surrounding the guiding core as a concept for an entirely integrated optofluidic platform for efficient refractive index sensing. Due to the extremely small optical core and the large adjacent microfluidic channels, over two orders of magnitude of nanoparticle coverage densities have been accessed with millimetre-long sample lengths showing refractive index sensitivities of 170 nm/RIU for aqueous analytes where the fibre interior is functionalised by gold nanospheres. Our concept represents a fully integrated optofluidic sensing system demanding small sample volumes and allowing for real-time analyte monitoring, both of which are highly relevant within invasive bioanalytics, particularly within molecular disease diagnostics and environmental science.
A high-throughput assay format for determination of nitrate reductase and nitrite reductase enzyme activities

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

McNally, N.; Liu, Xiang Yang; Choudary, P.V.

1997-01-01

The authors describe a microplate-based high-throughput procedure for rapid assay of the enzyme activities of nitrate reductase and nitrite reductase, using extremely small volumes of reagents. The new procedure offers the advantages of rapidity, small sample size-nanoliter volumes, low cost, and a dramatic increase in the throughput sample number that can be analyzed simultaneously. Additional advantages can be accessed by using microplate reader application software packages that permit assigning a group type to the wells, recording of the data on exportable data files and exercising the option of using the kinetic or endpoint reading modes. The assay can also bemore » used independently for detecting nitrite residues/contamination in environmental/food samples. 10 refs., 2 figs.« less
What Can You Do with a Returned Sample of Martian Dust?

NASA Technical Reports Server (NTRS)

Zolensky, Michael E.; Nakamura-Messenger, K.

2007-01-01

A major issue that we managed to successfully address for the Stardust Mission was the magnitude and manner of preliminary examination (PET) of the returned samples, which totaled much less than 1 mg. Not since Apollo and Luna days had anyone faced this issue, and the lessons of Apollo PET were not extremely useful because of the very different sample masses in this case, and the incredible advances in analytical capabilities since the 1960s. This paper reviews some of the techniques for examination of small very rare samples that would be returned from Mars missions.
Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2015-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.
Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2014-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.
Estimating forest attribute parameters for small areas using nearest neighbors techniques

Treesearch

Ronald E. McRoberts

2012-01-01

Nearest neighbors techniques have become extremely popular, particularly for use with forest inventory data. With these techniques, a population unit prediction is calculated as a linear combination of observations for a selected number of population units in a sample that are most similar, or nearest, in a space of ancillary variables to the population unit requiring...
Small amount of water induced preparation of several morphologies for InBO3:Eu3+ phosphor via a facile boric acid flux method and their luminescent properties

NASA Astrophysics Data System (ADS)

Ding, Wen; Liang, Pan; Liu, Zhi-Hong

2017-05-01

Four kinds of morphologies for InBO3:Eu3+ phosphor have been prepared via a facile boric acid flux method only by adjusting the small amount of added water. The prepared samples have been characterized by XRD, FT-IR, and SEM. It was found that the size and morphology of the samples could be effectively controlled by adjusting reaction temperature, reaction time, especially the small amount of added water, which plays an extremely critical role in the controlling morphology. The possible growth mechanisms for microsphere and flower-like morphologies were further discussed on the basis of time-dependent experiments. Furthermore, the luminescence properties of prepared InBO3:Eu3+ samples have been investigated by photoluminescence (PL) spectra. The results show that the InBO3:Eu3+ phosphors show strong orange emissions under ultraviolet excitation at 237 nm. The monodisperse microsphere sample possesses the highest PL intensity among above four morphologies, which can be used as a potential orange luminescent material.
Operational Risk Measurement of Chinese Commercial Banks Based on Extreme Value Theory

NASA Astrophysics Data System (ADS)

Song, Jiashan; Li, Yong; Ji, Feng; Peng, Cheng

The financial institutions and supervision institutions have all agreed on strengthening the measurement and management of operational risks. This paper attempts to build a model on the loss of operational risks basing on Peak Over Threshold model, emphasizing on weighted least square, which improved Hill’s estimation method, while discussing the situation of small sample, and fix the sample threshold more objectively basing on the media-published data of primary banks loss on operational risk from 1994 to 2007.
Multiplex APLP System for High-Resolution Haplogrouping of Extremely Degraded East-Asian Mitochondrial DNAs

PubMed Central

Kakuda, Tsuneo; Shojo, Hideki; Tanaka, Mayumi; Nambiar, Phrabhakaran; Minaguchi, Kiyoshi; Umetsu, Kazuo; Adachi, Noboru

2016-01-01

Mitochondrial DNA (mtDNA) serves as a powerful tool for exploring matrilineal phylogeographic ancestry, as well as for analyzing highly degraded samples, because of its polymorphic nature and high copy numbers per cell. The recent advent of complete mitochondrial genome sequencing has led to improved techniques for phylogenetic analyses based on mtDNA, and many multiplex genotyping methods have been developed for the hierarchical analysis of phylogenetically important mutations. However, few high-resolution multiplex genotyping systems for analyzing East-Asian mtDNA can be applied to extremely degraded samples. Here, we present a multiplex system for analyzing mitochondrial single nucleotide polymorphisms (mtSNPs), which relies on a novel amplified product-length polymorphisms (APLP) method that uses inosine-flapped primers and is specifically designed for the detailed haplogrouping of extremely degraded East-Asian mtDNAs. We used fourteen 6-plex polymerase chain reactions (PCRs) and subsequent electrophoresis to examine 81 haplogroup-defining SNPs and 3 insertion/deletion sites, and we were able to securely assign the studied mtDNAs to relevant haplogroups. Our system requires only 1×10−13 g (100 fg) of crude DNA to obtain a full profile. Owing to its small amplicon size (<110 bp), this new APLP system was successfully applied to extremely degraded samples for which direct sequencing of hypervariable segments using mini-primer sets was unsuccessful, and proved to be more robust than conventional APLP analysis. Thus, our new APLP system is effective for retrieving reliable data from extremely degraded East-Asian mtDNAs. PMID:27355212
Multiplex APLP System for High-Resolution Haplogrouping of Extremely Degraded East-Asian Mitochondrial DNAs.

PubMed

Kakuda, Tsuneo; Shojo, Hideki; Tanaka, Mayumi; Nambiar, Phrabhakaran; Minaguchi, Kiyoshi; Umetsu, Kazuo; Adachi, Noboru

2016-01-01

Mitochondrial DNA (mtDNA) serves as a powerful tool for exploring matrilineal phylogeographic ancestry, as well as for analyzing highly degraded samples, because of its polymorphic nature and high copy numbers per cell. The recent advent of complete mitochondrial genome sequencing has led to improved techniques for phylogenetic analyses based on mtDNA, and many multiplex genotyping methods have been developed for the hierarchical analysis of phylogenetically important mutations. However, few high-resolution multiplex genotyping systems for analyzing East-Asian mtDNA can be applied to extremely degraded samples. Here, we present a multiplex system for analyzing mitochondrial single nucleotide polymorphisms (mtSNPs), which relies on a novel amplified product-length polymorphisms (APLP) method that uses inosine-flapped primers and is specifically designed for the detailed haplogrouping of extremely degraded East-Asian mtDNAs. We used fourteen 6-plex polymerase chain reactions (PCRs) and subsequent electrophoresis to examine 81 haplogroup-defining SNPs and 3 insertion/deletion sites, and we were able to securely assign the studied mtDNAs to relevant haplogroups. Our system requires only 1×10-13 g (100 fg) of crude DNA to obtain a full profile. Owing to its small amplicon size (<110 bp), this new APLP system was successfully applied to extremely degraded samples for which direct sequencing of hypervariable segments using mini-primer sets was unsuccessful, and proved to be more robust than conventional APLP analysis. Thus, our new APLP system is effective for retrieving reliable data from extremely degraded East-Asian mtDNAs.
Preparation and physical characterization of pure beta-carotene.

PubMed

Laughlin, Robert G; Bunke, Gregory M; Eads, Charles D; Laidig, William D; Shelley, John C

2002-05-01

Pure all-trans beta-carotene has been prepared on the 10's of grams scale by isothermal Fractional Dissolution (FD) of commercial laboratory samples in tetrahydrofuran (THF). beta-Carotene purified in this way is black, with a faint brownish tinge. The electronic spectra of black samples extend into the near infrared, with end-absorption past 750 nm. Black samples react directly with dioxygen under mild conditions to yield the familiar orange or red powders. Pure beta-carotene rigorously obeys Beer's Law in octane over the entire UV-Vis spectral range, while commercial laboratory samples and recrystallized samples do not. NMR self-diffusion coefficient data demonstrate that beta-carotene exists as simple molecular solutions in octane and toluene. The anomalously high crystallinity of beta-carotene can be attributed (from analysis using molecular mechanics) to the facts that: (1) the number of theoretically possible conformers of beta-carotene is extremely small, and (2) only a small fraction of these (ca. 12%, or 127) may actually exist in fluid phases.
[New population curves in spanish extremely preterm neonates].

PubMed

García-Muñoz Rodrigo, F; García-Alix Pérez, A; Figueras Aloy, J; Saavedra Santana, P

2014-08-01

Most anthropometric reference data for extremely preterm infants used in Spain are outdated and based on non-Spanish populations, or are derived from small hospital-based samples that failed to include neonates of borderline viability. To develop gender-specific, population-based curves for birth weight, length, and head circumference in extremely preterm Caucasian infants, using a large contemporary sample size of Spanish singletons. Anthropometric data from neonates ≤ 28 weeks of gestational age were collected between January 2002 and December 2010 using the Spanish database SEN1500. Gestational age was estimated according to obstetric data (early pregnancy ultrasound). The data were analyzed with the SPSS.20 package, and centile tables were created for males and females using the Cole and Green LMS method. This study presents the first population-based growth curves for extremely preterm infants, including those of borderline viability, in Spain. A sexual dimorphism is evident for all of the studied parameters, starting at early gestation. These new gender-specific and population-based data could be useful for the improvement of growth assessments of extremely preterm infants in our country, for the development of epidemiological studies, for the evaluation of temporal trends, and for clinical or public health interventions seeking to optimize fetal growth. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Small Sample Reactivity Measurements in the RRR/SEG Facility: Reanalysis using TRIPOLI-4

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

Hummel, Andrew; Palmiotti, Guiseppe

2016-08-01

This work involved reanalyzing the RRR/SEG integral experiments performed at the Rossendorf facility in Germany throughout the 1970s and 80s. These small sample reactivity worth measurements were carried out using the pile oscillator technique for many different fission products, structural materials, and standards. The coupled fast-thermal system was designed such that the measurements would provide insight into elemental data, specifically the competing effects between neutron capture and scatter. Comparing the measured to calculated reactivity values can then provide adjustment criteria to ultimately improve nuclear data for fast reactor designs. Due to the extremely small reactivity effects measured (typically less thanmore » 1 pcm) and the specific heterogeneity of the core, the tool chosen for this analysis was TRIPOLI-4. This code allows for high fidelity 3-dimensional geometric modeling, and the most recent, unreleased version, is capable of exact perturbation theory.« less
The relationship between purely stochastic sampling error and the number of technical replicates used to estimate concentration at an extreme dilution

USDA-ARS?s Scientific Manuscript database

For any analytical system the population mean (mu) number of entities (e.g., cells or molecules) per tested volume, surface area, or mass also defines the population standard deviation (sigma = square root of mu ). For a preponderance of analytical methods, sigma is very small relative to mu due to...
Intervention for First Graders with Limited Number Knowledge: Large-Scale Replication of a Randomized Controlled Trial

ERIC Educational Resources Information Center

Gersten, Russell; Rolfhus, Eric; Clarke, Ben; Decker, Lauren E.; Wilkins, Chuck; Dimino, Joseph

2015-01-01

Replication studies are extremely rare in education. This randomized controlled trial (RCT) is a scale-up replication of Fuchs et al., which in a sample of 139 found a statistically significant positive impact for Number Rockets, a small-group intervention for at-risk first graders that focused on building understanding of number operations. The…
Porosity estimation by semi-supervised learning with sparsely available labeled samples

NASA Astrophysics Data System (ADS)

Lima, Luiz Alberto; Görnitz, Nico; Varella, Luiz Eduardo; Vellasco, Marley; Müller, Klaus-Robert; Nakajima, Shinichi

2017-09-01

This paper addresses the porosity estimation problem from seismic impedance volumes and porosity samples located in a small group of exploratory wells. Regression methods, trained on the impedance as inputs and the porosity as output labels, generally suffer from extremely expensive (and hence sparsely available) porosity samples. To optimally make use of the valuable porosity data, a semi-supervised machine learning method was proposed, Transductive Conditional Random Field Regression (TCRFR), showing good performance (Görnitz et al., 2017). TCRFR, however, still requires more labeled data than those usually available, which creates a gap when applying the method to the porosity estimation problem in realistic situations. In this paper, we aim to fill this gap by introducing two graph-based preprocessing techniques, which adapt the original TCRFR for extremely weakly supervised scenarios. Our new method outperforms the previous automatic estimation methods on synthetic data and provides a comparable result to the manual labored, time-consuming geostatistics approach on real data, proving its potential as a practical industrial tool.
Current trends in nanobiosensor technology

PubMed Central

Wu, Diana; Langer, Robert S

2014-01-01

The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material. PMID:21391305

Improving the performance of extreme learning machine for hyperspectral image classification

NASA Astrophysics Data System (ADS)

Li, Jiaojiao; Du, Qian; Li, Wei; Li, Yunsong

2015-05-01

Extreme learning machine (ELM) and kernel ELM (KELM) can offer comparable performance as the standard powerful classifier―support vector machine (SVM), but with much lower computational cost due to extremely simple training step. However, their performance may be sensitive to several parameters, such as the number of hidden neurons. An empirical linear relationship between the number of training samples and the number of hidden neurons is proposed. Such a relationship can be easily estimated with two small training sets and extended to large training sets so as to greatly reduce computational cost. Other parameters, such as the steepness parameter in the sigmodal activation function and regularization parameter in the KELM, are also investigated. The experimental results show that classification performance is sensitive to these parameters; fortunately, simple selections will result in suboptimal performance.
Blueberry Galaxies: The Lowest Mass Young Starbursts

NASA Astrophysics Data System (ADS)

Yang, Huan; Malhotra, Sangeeta; Rhoads, James E.; Wang, Junxian

2017-09-01

Searching for extreme emission line galaxies allows us to find low-mass metal-poor galaxies that are good analogs of high redshift Lyα emitting galaxies. These low-mass extreme emission line galaxies are also potential Lyman-continuum leakers. Finding them at very low redshifts (z≲ 0.05) allows us to be sensitive to even lower stellar masses and metallicities. We report on a sample of extreme emission line galaxies at z≲ 0.05 (blueberry galaxies). We selected them from SDSS broadband images on the basis of their broadband colors and studied their properties with MMT spectroscopy. From the entire SDSS DR12 photometric catalog, we found 51 photometric candidates. We spectroscopically confirm 40 as blueberry galaxies. (An additional seven candidates are contaminants, and four remain without spectra.) These blueberries are dwarf starburst galaxies with very small sizes (<1 kpc) and very high ionization ([O III]/[O II] ˜ 10-60). They also have some of the lowest stellar masses ({log}(M/{M}⊙ )˜ 6.5{--}7.5) and lowest metallicities (7.1< 12+{log}({{O}}/{{H}})< 7.8) of starburst galaxies. Thus, they are small counterparts to green pea galaxies and high redshift Lyα emitting galaxies.
Chrysotile in water

PubMed Central

Speil, Sidney

1974-01-01

The problems of quantitating chrysotile in water by fiber count techniques are reviewed briefly and the use of mass quantitation is suggested as a preferable measure. Chrysotile fiber has been found in almost every sample of natural water examined, but generally transmission electron miscroscopy (TEM) is required because of the small diameters involved. The extreme extrapolation required in mathematically converting a few fibers or fiber fragments under the TEM to the fiber content of a liquid sample casts considerable doubt on the validity of numbers used to compare chrysotile contents of different liquids. PMID:4470930
Rare event simulation in radiation transport

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

Kollman, Craig

1993-10-01

This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved,more » even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiple by the likelihood ratio between the true and simulated probabilities so as to keep the estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive ``learning`` algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give with probability one, a sequence of estimates converging exponentially fast to the true solution.« less
Extraction and labeling methods for microarrays using small amounts of plant tissue.

PubMed

Stimpson, Alexander J; Pereira, Rhea S; Kiss, John Z; Correll, Melanie J

2009-03-01

Procedures were developed to maximize the yield of high-quality RNA from small amounts of plant biomass for microarrays. Two disruption techniques (bead milling and pestle and mortar) were compared for the yield and the quality of RNA extracted from 1-week-old Arabidopsis thaliana seedlings (approximately 0.5-30 mg total biomass). The pestle and mortar method of extraction showed enhanced RNA quality at the smaller biomass samples compared with the bead milling technique, although the quality in the bead milling could be improved with additional cooling steps. The RNA extracted from the pestle and mortar technique was further tested to determine if the small quantity of RNA (500 ng-7 microg) was appropriate for microarray analyses. A new method of low-quantity RNA labeling for microarrays (NuGEN Technologies, Inc.) was used on five 7-day-old seedlings (approximately 2.5 mg fresh weight total) of Arabidopsis that were grown in the dark and exposed to 1 h of red light or continued dark. Microarray analyses were performed on a small plant sample (five seedlings; approximately 2.5 mg) using these methods and compared with extractions performed with larger biomass samples (approximately 500 roots). Many well-known light-regulated genes between the small plant samples and the larger biomass samples overlapped in expression changes, and the relative expression levels of selected genes were confirmed with quantitative real-time polymerase chain reaction, suggesting that these methods can be used for plant experiments where the biomass is extremely limited (i.e. spaceflight studies).
Spin-orbit torque induced magnetization switching in Ta/Co{sub 20}Fe{sub 60}B{sub 20}/MgO structures under small in-plane magnetic fields

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

Cao, Jiangwei, E-mail: caojw@lzu.edu.cn; Zheng, Yuqiang; Su, Xianpeng

2016-04-25

Spin-orbit torque (SOT)-induced magnetization switching under small in-plane magnetic fields in as-deposited and annealed Ta/CoFeB/MgO structures is studied. For the as-deposited samples, partial SOT-induced switching behavior is observed under an in-plane field of less than 100 Oe. Conversely, for the annealed samples, an in-plane field of 10 Oe is large enough to achieve full deterministic magnetization switching. The Dzyaloshinskii-Moriya interaction at the Ta/CoFeB interface is believed to be the main reason for the discrepancy of the requisite in-plane magnetic fields for switching in the as-deposited and annealed samples. In addition, asymmetric field dependence behavior of SOT-induced magnetization switching is observed in themore » annealed samples. Deterministic magnetization switching in the absence of an external magnetic field is obtained in the annealed samples, which is extremely important to develop SOT-based magnetoresistive random access memory.« less
Spitzer SAGE-Spec: Near infrared spectroscopy, dust shells, and cool envelopes in extreme Large Magellanic Cloud asymptotic giant branch stars

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

Blum, R. D.; Srinivasan, S.; Kemper, F.

2014-11-01

K-band spectra are presented for a sample of 39 Spitzer Infrared Spectrograph (IRS) SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near-infrared—Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near-infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars was chosen from the luminous and red extreme ''tip'' of the color-magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich ''stellar'' cores. Modest amountsmore » of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near-infrared and mid-infrared colors. One object in our sample, HV 915, a known post-asymptotic giant branch star of the RV Tau type, exhibits CO 2.3 μm band head emission consistent with previous work that demonstrates that the object has a circumstellar disk.« less
The relationship between lower extremity alignment and Medial Tibial Stress Syndrome among non-professional athletes

PubMed Central

Raissi, Golam Reza D; Cherati, Afsaneh D Safar; Mansoori, Kourosh D; Razi, Mohammad D

2009-01-01

Objective To determine the relationship between lower extremity alignment and MTSS amongst non-professional athletes Design In a prospective Study, sixty six subjects were evaluated. Bilateral navicular drop test, Q angle, Achilles angle, tibial angle, intermalleolar and intercondylar distance were measured. In addition, runner's height, body mass, history of previous running injury, running experience was recorded. Runners were followed for 17 weeks to determine occurrence of MTSS. Results The overall injury rate for MTSS was 19.7%. The MTSS injury rate in girls (22%) was not significantly different from the rate in boys (14.3%). Most MTSS injuries were induced after 60 hours of exercise, which did not differ between boys and girls. There was a significant difference in right and left navicular drop (ND) in athletes with MTSS. MTSS had no significant correlation with other variables including Quadriceps, Tibia and Achilles angles, intercondylar and intermaleolar lengths and lower extremity lengths. Limitation All measurements performed in this study were uniplanar and static. The small sample size deemed our main limitation. The accurate assessment of participants with previous history of anterior leg pain for MTSS was another limitation. Conclusion Although a significant relationship between navicular drop and MTSS was found in this study; there was not any significant relationship between lower extremity alignment and MTSS in our sample study. PMID:19519909
Abundance Ratios in a Large Sample of Emps with VLT+UVES

NASA Astrophysics Data System (ADS)

Hill, Vanessa; Cayrel, Roger; Spite, Monique; Bonifacio, Piercarlo; Eric, Depagne; Patrick, François; Timothy, Beers C.; Johannes, Andersen; Beatriz, Barbuy; Birgitta, Nordström

Constraints on Early Galactic Enrichement from a large sample of Extremely Metal Poor Stars I will present the overall results from an large effort conducted at ESO-VLT+UVES to measure abundances in a sample of extremely metal-poor stars (EMPS) from high-resolution and high signal to noise spectra. More than 70 EMPS with [Fe/H]<-2.7 were observed equally distributed between turnoff and giants stars and very precise abundance ratios could be derived thanks to the high quality of the data. Among the results those of specific interest are lithium measurements in unevolved EMPS the much debated abundance of oxygen in the early galaxy (we present [OI] line measurements down to [O/Fe]=-3.5) and the trends of alpha elements iron group elements and Zinc. The scatter around these trends will also be discussed taking advantage of the small observationnal error-bars of this dataset. The implications on the early Galactic enrichement will be rewiewed while more specific topics covered by this large effort (and large team) will be adressed in devoted posters.
Neutron Time-of-Flight Diffractometer HIPPO at LANSCE

NASA Astrophysics Data System (ADS)

Vogel, Sven; Williams, Darrick; Zhao, Yusheng; Bennett, Kristin; von Dreele, Bob; Wenk, Hans-Rudolf

2004-03-01

The High-Pressure Preferred Orientation (HIPPO) neutron diffractometer is the first third-generation neutron time-of-flight powder diffractometer to be constructed in the United States. It produces extremely high intensity by virtue of a short (9 m) initial flight path on a high intensity water moderator and 1380 3He detector tubes covering 4.5 m2 of detector area from 10' to 150' in scattering angles. HIPPO was designed and manufactured as a joint effort between LANSCE and University of California with the goals of attaining world-class science and making neutron powder diffractometry an accessible and available tool to the national user community. Over two decades of momentum transfer are available (0.1-30 A-1) to support studies of amorphous solids; magnetic diffraction; small crystalline samples; and samples subjected to extreme environments such as temperature, pressure, or magnetic fields. The exceptionally high data rates of HIPPO also make it useful for time-resolved studies. In addition to the standard ancillary equipment (100-position sample/texture changer, closed-cycle He refrigerator, furnace), HIPPO has unique high-pressure cells capable of achieving pressures of 30 GPA at ambient and high (2000 K) temperature with samples up to 100 mm3 in volume.
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.
The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at >10 keV

NASA Astrophysics Data System (ADS)

Lansbury, G. B.; Alexander, D. M.; Aird, J.; Gandhi, P.; Stern, D.; Koss, M.; Lamperti, I.; Ajello, M.; Annuar, A.; Assef, R. J.; Ballantyne, D. R.; Baloković, M.; Bauer, F. E.; Brandt, W. N.; Brightman, M.; Chen, C.-T. J.; Civano, F.; Comastri, A.; Del Moro, A.; Fuentes, C.; Harrison, F. A.; Marchesi, S.; Masini, A.; Mullaney, J. R.; Ricci, C.; Saez, C.; Tomsick, J. A.; Treister, E.; Walton, D. J.; Zappacosta, L.

2017-09-01

We identify sources with extremely hard X-ray spectra (I.e., with photon indices of {{Γ }}≲ 0.6) in the 13 deg2 NuSTAR serendipitous survey, to search for the most highly obscured active galactic nuclei (AGNs) detected at > 10 {keV}. Eight extreme NuSTAR sources are identified, and we use the NuSTAR data in combination with lower-energy X-ray observations (from Chandra, Swift XRT, and XMM-Newton) to characterize the broadband (0.5-24 keV) X-ray spectra. We find that all of the extreme sources are highly obscured AGNs, including three robust Compton-thick (CT; {N}{{H}}> 1.5× {10}24 cm-2) AGNs at low redshift (z< 0.1) and a likely CT AGN at higher redshift (z = 0.16). Most of the extreme sources would not have been identified as highly obscured based on the low-energy (< 10 keV) X-ray coverage alone. The multiwavelength properties (e.g., optical spectra and X-ray-mid-IR luminosity ratios) provide further support for the eight sources being significantly obscured. Correcting for absorption, the intrinsic rest-frame 10-40 keV luminosities of the extreme sources cover a broad range, from ≈ 5× {10}42 to 1045 erg s-1. The estimated number counts of CT AGNs in the NuSTAR serendipitous survey are in broad agreement with model expectations based on previous X-ray surveys, except for the lowest redshifts (z< 0.07), where we measure a high CT fraction of {f}{CT}{obs}={30}-12+16 % . For the small sample of CT AGNs, we find a high fraction of galaxy major mergers (50% ± 33%) compared to control samples of “normal” AGNs.
EPA's National Coastal Condition Assessment: Pilot research ...

EPA Pesticide Factsheets

The EPA Office of Water’s 5-year cycles of national surveys of wetlands, lakes, rivers, and coastal areas help satisfy the assessment and antidegradation provisions of the Clean Water Act. Measuring extant conditions precedes measuring change in conditions. Surveys are challenged to adequately sample extreme conditions occurring in small areas. Extremely bad conditions are targets for remediation. Extremely good conditions are targets for protection. In 2010, the National Coastal Condition Assessment (NCCA) found the majority of the coastal Great Lakes (by area) was in good condition for water (60%) and sediment (51%) quality but not benthos (20%) and fish tissue contaminants (<1%). Low sampling success for biological sampling was an issue. As part of the 2014 Lake Erie CSMI field year, EPA’s Great Lakes National Program Office, working with the Office of Research and Development, began pilot research to integrate connecting channels into Great Lakes surveys. Assessments of the Huron-Erie corridor (HEC; 2014, 2015) and St Marys River (SMR; 2015, 2016) which have previously gone unassessed by NCCA, are being developed. Water, sediment, and benthic quality data from the 2014 HEC survey (n=60) were compared to 2010 NCCA data from adjacent lakes. Water quality rated “poor” (as % area) in HEC was intermediate compared to Lake Huron and Erie regardless of which lake-specific thresholds were used. However, the amount of area classified as “good” was highl
Global Weirding? - Using Very Large Ensembles and Extreme Value Theory to assess Changes in Extreme Weather Events Today

NASA Astrophysics Data System (ADS)

Otto, F. E. L.; Mitchell, D.; Sippel, S.; Black, M. T.; Dittus, A. J.; Harrington, L. J.; Mohd Saleh, N. H.

2014-12-01

A shift in the distribution of socially-relevant climate variables such as daily minimum winter temperatures and daily precipitation extremes, has been attributed to anthropogenic climate change for various mid-latitude regions. However, while there are many process-based arguments suggesting also a change in the shape of these distributions, attribution studies demonstrating this have not currently been undertaken. Here we use a very large initial condition ensemble of ~40,000 members simulating the European winter 2013/2014 using the distributed computing infrastructure under the weather@home project. Two separate scenarios are used:1. current climate conditions, and 2. a counterfactual scenario of "world that might have been" without anthropogenic forcing. Specifically focusing on extreme events, we assess how the estimated parameters of the Generalized Extreme Value (GEV) distribution vary depending on variable-type, sampling frequency (daily, monthly, …) and geographical region. We find that the location parameter changes for most variables but, depending on the region and variables, we also find significant changes in scale and shape parameters. The very large ensemble allows, furthermore, to assess whether such findings in the fitted GEV distributions are consistent with an empirical analysis of the model data, and whether the most extreme data still follow a known underlying distribution that in a small sample size might otherwise be thought of as an out-lier. The ~40,000 member ensemble is simulated using 12 different SST patterns (1 'observed', and 11 best guesses of SSTs with no anthropogenic warming). The range in SSTs, along with the corresponding changings in the NAO and high-latitude blocking inform on the dynamics governing some of these extreme events. While strong tele-connection patterns are not found in this particular experiment, the high number of simulated extreme events allows for a more thorough analysis of the dynamics than has been performed before. Therefore, combining extreme value theory with very large ensemble simulations allows us to understand the dynamics of changes in extreme events which is not possible just using the former but also shows in which cases statistics combined with smaller ensembles give as valid results as very large initial conditions.
Local reconstruction in computed tomography of diffraction enhanced imaging

NASA Astrophysics Data System (ADS)

Huang, Zhi-Feng; Zhang, Li; Kang, Ke-Jun; Chen, Zhi-Qiang; Zhu, Pei-Ping; Yuan, Qing-Xi; Huang, Wan-Xia

2007-07-01

Computed tomography of diffraction enhanced imaging (DEI-CT) based on synchrotron radiation source has extremely high sensitivity of weakly absorbing low-Z samples in medical and biological fields. The authors propose a modified backprojection filtration(BPF)-type algorithm based on PI-line segments to reconstruct region of interest from truncated refraction-angle projection data in DEI-CT. The distribution of refractive index decrement in the sample can be directly estimated from its reconstruction images, which has been proved by experiments at the Beijing Synchrotron Radiation Facility. The algorithm paves the way for local reconstruction of large-size samples by the use of DEI-CT with small field of view based on synchrotron radiation source.
A comparative analysis of support vector machines and extreme learning machines.

PubMed

Liu, Xueyi; Gao, Chuanhou; Li, Ping

2012-09-01

The theory of extreme learning machines (ELMs) has recently become increasingly popular. As a new learning algorithm for single-hidden-layer feed-forward neural networks, an ELM offers the advantages of low computational cost, good generalization ability, and ease of implementation. Hence the comparison and model selection between ELMs and other kinds of state-of-the-art machine learning approaches has become significant and has attracted many research efforts. This paper performs a comparative analysis of the basic ELMs and support vector machines (SVMs) from two viewpoints that are different from previous works: one is the Vapnik-Chervonenkis (VC) dimension, and the other is their performance under different training sample sizes. It is shown that the VC dimension of an ELM is equal to the number of hidden nodes of the ELM with probability one. Additionally, their generalization ability and computational complexity are exhibited with changing training sample size. ELMs have weaker generalization ability than SVMs for small sample but can generalize as well as SVMs for large sample. Remarkably, great superiority in computational speed especially for large-scale sample problems is found in ELMs. The results obtained can provide insight into the essential relationship between them, and can also serve as complementary knowledge for their past experimental and theoretical comparisons. Copyright © 2012 Elsevier Ltd. All rights reserved.
Abstract - Cooperative Research and Development Agreement between Oxergy, Inc. and National Energy Technology Laboratory

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

Chorpening, Benjamin T.; Kamler, Jonathan

The Raman Gas Analyzer (RGA) has been demonstrated to have an extremely fast response (<1 second), pressurized, multi-gas analysis capability. All but the noble gases are Raman active, although the Raman interaction is weak. The RGA uses a reflectively lined capillary as the optical cell, providing both a small sample volume for fast gas exchange, and a much greater Raman signal collection than traditional instrument configurations.
A rational decision rule with extreme events.

PubMed

Basili, Marcello

2006-12-01

Risks induced by extreme events are characterized by small or ambiguous probabilities, catastrophic losses, or windfall gains. Through a new functional, that mimics the restricted Bayes-Hurwicz criterion within the Choquet expected utility approach, it is possible to represent the decisionmaker behavior facing both risky (large and reliable probability) and extreme (small or ambiguous probability) events. A new formalization of the precautionary principle (PP) is shown and a new functional, which encompasses both extreme outcomes and expectation of all the possible results for every act, is claimed.
Analysis of small sample size studies using nonparametric bootstrap test with pooled resampling method.

PubMed

Dwivedi, Alok Kumar; Mallawaarachchi, Indika; Alvarado, Luis A

2017-06-30

Experimental studies in biomedical research frequently pose analytical problems related to small sample size. In such studies, there are conflicting findings regarding the choice of parametric and nonparametric analysis, especially with non-normal data. In such instances, some methodologists questioned the validity of parametric tests and suggested nonparametric tests. In contrast, other methodologists found nonparametric tests to be too conservative and less powerful and thus preferred using parametric tests. Some researchers have recommended using a bootstrap test; however, this method also has small sample size limitation. We used a pooled method in nonparametric bootstrap test that may overcome the problem related with small samples in hypothesis testing. The present study compared nonparametric bootstrap test with pooled resampling method corresponding to parametric, nonparametric, and permutation tests through extensive simulations under various conditions and using real data examples. The nonparametric pooled bootstrap t-test provided equal or greater power for comparing two means as compared with unpaired t-test, Welch t-test, Wilcoxon rank sum test, and permutation test while maintaining type I error probability for any conditions except for Cauchy and extreme variable lognormal distributions. In such cases, we suggest using an exact Wilcoxon rank sum test. Nonparametric bootstrap paired t-test also provided better performance than other alternatives. Nonparametric bootstrap test provided benefit over exact Kruskal-Wallis test. We suggest using nonparametric bootstrap test with pooled resampling method for comparing paired or unpaired means and for validating the one way analysis of variance test results for non-normal data in small sample size studies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Characterizing the growth to detonation in HNS with small-scale PDV "cutback" experiments

NASA Astrophysics Data System (ADS)

Wixom, Ryan R.; Yarrington, Cole D.; Knepper, Robert; Tappan, Alexander S.; Olles, Joseph D.; Damm, David L.

2017-01-01

For many decades, cutback experiments have been used to characterize the equation of state and growth to steady detonation in explosive formulations. More recently, embedded gauges have been used to capture the growth to steady detonation in gas-gun impacted samples. Data resulting from these experiments are extremely valuable for parameterizing equation of state and reaction models used in hydrocode simulations. Due to the extremely fast growth to detonation in typical detonator explosives, cutback and embedded gauge experiments are particularly difficult, if not impossible. Using frequency shifted photonic Doppler velocimetry (PDV) we have measured particle velocity histories from vapor-deposited explosive films impacted with electrically driven flyers. By varying the sample thickness and impact conditions we were able to capture the growth from inert shock to full detonation pressure within distances as short as 100 µm. These data are being used to assess and improve burn-model parameterization and equations of state for simulating shock initiation.

Characterization of the microbial community composition and the distribution of Fe-metabolizing bacteria in a creek contaminated by acid mine drainage.

PubMed

Sun, Weimin; Xiao, Enzong; Krumins, Valdis; Dong, Yiran; Xiao, Tangfu; Ning, Zengping; Chen, Haiyan; Xiao, Qingxiang

2016-10-01

A small watershed heavily contaminated by long-term acid mine drainage (AMD) from an upstream abandoned coal mine was selected to study the microbial community developed in such extreme system. The watershed consists of AMD-contaminated creek, adjacent contaminated soils, and a small cascade aeration unit constructed downstream, which provide an excellent contaminated site to study the microbial response in diverse extreme AMD-polluted environments. The results showed that the innate microbial communities were dominated by acidophilic bacteria, especially acidophilic Fe-metabolizing bacteria, suggesting that Fe and pH are the primary environmental factors in governing the indigenous microbial communities. The distribution of Fe-metabolizing bacteria showed distinct site-specific patterns. A pronounced shift from diverse communities in the upstream to Proteobacteria-dominated communities in the downstream was observed in the ecosystem. This location-specific trend was more apparent at genus level. In the upstream samples (sampling sites just below the coal mining adit), a number of Fe(II)-oxidizing bacteria such as Alicyclobacillus spp., Metallibacterium spp., and Acidithrix spp. were dominant, while Halomonas spp. were the major Fe(II)-oxidizing bacteria observed in downstream samples. Additionally, Acidiphilium, an Fe(III)-reducing bacterium, was enriched in the upstream samples, while Shewanella spp. were the dominant Fe(III)-reducing bacteria in downstream samples. Further investigation using linear discriminant analysis (LDA) effect size (LEfSe), principal coordinate analysis (PCoA), and unweighted pair group method with arithmetic mean (UPGMA) clustering confirmed the difference of microbial communities between upstream and downstream samples. Canonical correspondence analysis (CCA) and Spearman's rank correlation indicate that total organic carbon (TOC) content is the primary environmental parameter in structuring the indigenous microbial communities, suggesting that the microbial communities are shaped by three major environmental parameters (i.e., Fe, pH, and TOC). These findings were beneficial to a better understanding of natural attenuation of AMD.
Microwave Atmospheric Sounder on CubeSat

NASA Astrophysics Data System (ADS)

Padmanabhan, S.; Brown, S. E.; Kangaslahti, P.; Cofield, R.; Russell, D.; Stachnik, R. A.; Su, H.; Wu, L.; Tanelli, S.; Niamsuwan, N.

2014-12-01

To accurately predict how the distribution of extreme events may change in the future we need to understand the mechanisms that influence such events in our current climate. Our current observing system is not well-suited for observing extreme events globally due to the sparse sampling and in-homogeneity of ground-based in-situ observations and the infrequent revisit time of satellite observations. Observations of weather extremes, such as extreme precipitation events, temperature extremes, tropical and extra-tropical cyclones among others, with temporal resolution on the order of minutes and spatial resolution on the order of few kms (<10 kms), are required for improved forecasting of extreme weather events. We envision a suite of low-cost passive microwave sounding and imaging sensors on CubeSats that would work in concert with traditional flagship observational systems, such as those manifested on large environmental satellites (i.e. JPSS,WSF,GCOM-W), to monitor weather extremes. A 118/183 GHz sensor would enable observations of temperature and precipitation extremes over land and ocean as well as tropical and extra-tropical cyclones. This proposed project would enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U Cubesat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters needed to improve prediction of extreme weather events. We take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass, low-power high frequency airborne radiometers. In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder on the 6U CubeSat. In addition, a summary of radiometer calibration and retrieval techniques of temperature and humidity will be discussed. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a constellation which could sample tropospheric temperature and humidity with fine temporal and spatial resolution.
Airborne Deployment and Calibration of Microwave Atmospheric Sounder on 6U CubeSat

NASA Astrophysics Data System (ADS)

Padmanabhan, S.; Brown, S. T.; Lim, B.; Kangaslahti, P.; Russell, D.; Stachnik, R. A.

2015-12-01

To accurately predict how the distribution of extreme events may change in the future we need to understand the mechanisms that influence such events in our current climate. Our current observing system is not well-suited for observing extreme events globally due to the sparse sampling and in-homogeneity of ground-based in-situ observations and the infrequent revisit time of satellite observations. Observations of weather extremes, such as extreme precipitation events, temperature extremes, tropical and extra-tropical cyclones among others, with temporal resolution on the order of minutes and spatial resolution on the order of few kms (<10 kms), are required for improved forecasting of extreme weather events. We envision a suite of low-cost passive microwave sounding and imaging sensors on CubeSats that would work in concert with traditional flagship observational systems, such as those manifested on large environmental satellites (i.e. JPSS,WSF,GCOM-W), to monitor weather extremes. A 118/183 GHz sensor would enable observations of temperature and precipitation extremes over land and ocean as well as tropical and extra-tropical cyclones. This proposed project would enable low cost, compact radiometer instrumentation at 118 and 183 GHz that would fit in a 6U Cubesat with the objective of mass-producing this design to enable a suite of small satellites to image the key geophysical parameters needed to improve prediction of extreme weather events. We take advantage of past and current technology developments at JPL viz. HAMSR (High Altitude Microwave Scanning Radiometer), Advanced Component Technology (ACT'08) to enable low-mass, low-power high frequency airborne radiometers. In this paper, we will describe the design and implementation of the 118 GHz temperature sounder and 183 GHz humidity sounder on the 6U CubeSat. In addition, we will discuss the maiden airborne deployment of the instrument during the Plain Elevated Convection at Night (PECAN) experiment. The successful demonstration of this instrument on the 6U CubeSat would pave the way for the development of a constellation which could sample tropospheric temperature and humidity with fine temporal and spatial resolution.
Refined Proterozoic evolution of the Gawler Craton, South Australia, through U-Pb zircon geochronology

USGS Publications Warehouse

Fanning, C.M.; Flint, R.B.; Parker, A.J.; Ludwig, K. R.; Blissett, A.H.

1988-01-01

Through the application of both conventional U-Pb zircon analyses and small-sample U-Pb isotopic analyses, the nature and timing of tectonic events leading to the formation of the Gawler Craton have been defined more precisely. Constraints on deposition of Early Proterozoic iron formation-bearing sediments have been narrowed down to the period 1960-1847 Ma. Deformed acid volcanics, including the economically important Moonta Porphyry, have zircon ages of ??? 1790 and 1740 Ma. The voluminous acid Gawler Range Volcanics and correlatives to the east were erupted over a short interval at 1592 ?? 2 Ma, and were intruded by anorogenic granites at ??? 1575 Ma. Small-sample zircon analyses proved to be an extremely valuable adjunct to conventional analyses, generally yielding more-concordant data which forced a curved discordia through an upper intercept slightly younger than from a conventional straight-line discordia. ?? 1988.
Toxicity reduction of photo processing wastewaters

USGS Publications Warehouse

Wang, W.

1992-01-01

The photo processing industry can be characterized by treatment processes and subsequent silver recovery. The effluents generated all contain various amounts of silver. The objectives of this study were to determine toxicity of photo processing effluents and to explore their toxicity mitigation. Six samples, from small shops to a major photo processing center, were studied. Two samples (I and VI) were found to be extremely toxic, causing 100 and 99% inhibition of duckweed frond reproduction, respectively, and were used for subsequent toxicity reduction experiments. Lime and sodium sulfide were effective for the toxicity reduction of Sample VI; both reduced its toxicity to negligible. Sample I was far more toxic and was first diluted to 2.2% and then treated with 0.5 g lime/100 mL, reducing toxicity from 100% to 12% inhibition.
Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

PubMed

Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

2013-09-01

The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.
Tropical Processes Applications for CYGNSS

NASA Technical Reports Server (NTRS)

Lang, Timothy J.

2017-01-01

The Cyclone Global Navigation Satellite System (CYGNSS) is focused primarily on observing extreme winds in the inner core of tropical cyclones But... Named storms will occur in view of CYGNSS constellation for only a small percentage of the time on orbit And... Rapid-update, all-weather sampling of wind speeds has many other applications in Tropical Meteorology So... Many potential tropical processes applications for CYGNSS were identified in previous Workshop - Let's revisit some of these possibilities now that the mission is up.
Deep learning in the small sample size setting: cascaded feed forward neural networks for medical image segmentation

NASA Astrophysics Data System (ADS)

Gaonkar, Bilwaj; Hovda, David; Martin, Neil; Macyszyn, Luke

2016-03-01

Deep Learning, refers to large set of neural network based algorithms, have emerged as promising machine- learning tools in the general imaging and computer vision domains. Convolutional neural networks (CNNs), a specific class of deep learning algorithms, have been extremely effective in object recognition and localization in natural images. A characteristic feature of CNNs, is the use of a locally connected multi layer topology that is inspired by the animal visual cortex (the most powerful vision system in existence). While CNNs, perform admirably in object identification and localization tasks, typically require training on extremely large datasets. Unfortunately, in medical image analysis, large datasets are either unavailable or are extremely expensive to obtain. Further, the primary tasks in medical imaging are organ identification and segmentation from 3D scans, which are different from the standard computer vision tasks of object recognition. Thus, in order to translate the advantages of deep learning to medical image analysis, there is a need to develop deep network topologies and training methodologies, that are geared towards medical imaging related tasks and can work in a setting where dataset sizes are relatively small. In this paper, we present a technique for stacked supervised training of deep feed forward neural networks for segmenting organs from medical scans. Each `neural network layer' in the stack is trained to identify a sub region of the original image, that contains the organ of interest. By layering several such stacks together a very deep neural network is constructed. Such a network can be used to identify extremely small regions of interest in extremely large images, inspite of a lack of clear contrast in the signal or easily identifiable shape characteristics. What is even more intriguing is that the network stack achieves accurate segmentation even when it is trained on a single image with manually labelled ground truth. We validate this approach,using a publicly available head and neck CT dataset. We also show that a deep neural network of similar depth, if trained directly using backpropagation, cannot acheive the tasks achieved using our layer wise training paradigm.
Regression and Data Mining Methods for Analyses of Multiple Rare Variants in the Genetic Analysis Workshop 17 Mini-Exome Data

PubMed Central

Bailey-Wilson, Joan E.; Brennan, Jennifer S.; Bull, Shelley B; Culverhouse, Robert; Kim, Yoonhee; Jiang, Yuan; Jung, Jeesun; Li, Qing; Lamina, Claudia; Liu, Ying; Mägi, Reedik; Niu, Yue S.; Simpson, Claire L.; Wang, Libo; Yilmaz, Yildiz E.; Zhang, Heping; Zhang, Zhaogong

2012-01-01

Group 14 of Genetic Analysis Workshop 17 examined several issues related to analysis of complex traits using DNA sequence data. These issues included novel methods for analyzing rare genetic variants in an aggregated manner (often termed collapsing rare variants), evaluation of various study designs to increase power to detect effects of rare variants, and the use of machine learning approaches to model highly complex heterogeneous traits. Various published and novel methods for analyzing traits with extreme locus and allelic heterogeneity were applied to the simulated quantitative and disease phenotypes. Overall, we conclude that power is (as expected) dependent on locus-specific heritability or contribution to disease risk, large samples will be required to detect rare causal variants with small effect sizes, extreme phenotype sampling designs may increase power for smaller laboratory costs, methods that allow joint analysis of multiple variants per gene or pathway are more powerful in general than analyses of individual rare variants, population-specific analyses can be optimal when different subpopulations harbor private causal mutations, and machine learning methods may be useful for selecting subsets of predictors for follow-up in the presence of extreme locus heterogeneity and large numbers of potential predictors. PMID:22128066
Micro-tensile testing system

DOEpatents

Wenski, Edward G [Lenexa, KS

2007-08-21

A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.
Micro-tensile testing system

DOEpatents

Wenski, Edward G.

2006-01-10

A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.
Micro-tensile testing system

DOEpatents

Wenski, Edward G [Lenexa, KS

2007-07-17

A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.
A recommended procedure for the preparation of oriented clay-mineral specimens for X-ray diffraction analysis; modifications to Drever's filter-membrane peel technique

USGS Publications Warehouse

Pollastro, R.M.

1982-01-01

Extremely well-oriented clay mineral mounts for X-ray diffraction analysis can be prepared quickly and without introducing segregation using the filter-membrane peel technique. Mounting problems encountered with smectite-rich samples can be resolved by using minimal sample and partial air-drying of the clay film before transfer to a glass slide. Samples containing small quantities of clay can produce useful oriented specimens if Teflon masks having more restrictive areas are inserted above the membrane filter during clay deposition. War]page and thermal shock of glass slides can be controlled by using a flat, porous, ceramic plate as a holding surface during heat treatments.
Evidence for extreme Ti-50 enrichments in primitive meteorites

NASA Technical Reports Server (NTRS)

Fahey, A.; Mckeegan, K. D.; Zinner, E.; Goswami, J. N.

1985-01-01

The results of the first high mass resolution ion microprobe study of Ti isotopic compositions in individual refractory grains from primitive carbonaceous meteorites are reported. One hibonite from the Murray carbonaceous chondrite has a 10 percent excess of Ti-50, 25 times higher than the maximum value previously reported for bulk samples of refractory inclusions from carbonaceous chondrites. The variation of the Ti compositions between different hibonite grains, and among pyroxenes from a single Allende refractory inclusion, indicates isotopic inhomogeneities over small scale lengths in the solar nebula and emphasizes the importance of the analysis of small individual phases. This heterogeneity makes it unlikely that the isotopic anomalies were carried into the solar system in the gas phase.
Extreme obesity reduces bone mineral density: complementary evidence from mice and women.

PubMed

Núñez, Nomelí P; Carpenter, Catherine L; Perkins, Susan N; Berrigan, David; Jaque, S Victoria; Ingles, Sue Ann; Bernstein, Leslie; Forman, Michele R; Barrett, J Carl; Hursting, Stephen D

2007-08-01

To evaluate the effects of body adiposity on bone mineral density in the presence and absence of ovarian hormones in female mice and postmenopausal women. We assessed percentage body fat, serum leptin levels, and bone mineral density in ovariectomized and non-ovariectomized C57BL/6 female mice that had been fed various calorically dense diets to induce body weight profiles ranging from lean to very obese. Additionally, we assessed percentage body fat and whole body bone mineral density in 37 overweight and extremely obese postmenopausal women from the Women's Contraceptive and Reproductive Experiences study. In mice, higher levels of body adiposity (>40% body fat) were associated with lower bone mineral density in ovariectomized C57BL/6 female mice. A similar trend was observed in a small sample of postmenopausal women. The complementary studies in mice and women suggest that extreme obesity in postmenopausal women may be associated with reduced bone mineral density. Thus, extreme obesity (BMI > 40 kg/m2) may increase the risk for osteopenia and osteoporosis. Given the obesity epidemic in the U.S. and in many other countries, and, in particular, the rising number of extremely obese adult women, increased attention should be drawn to the significant and interrelated public health issues of obesity and osteoporosis.
Thermal Inertia of Rocks and Rock Populations and Implications for Landing Hazards on Mars

NASA Technical Reports Server (NTRS)

Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

2001-01-01

Rocks represent an obvious potential hazard to a landing spacecraft. They also represent an impediment to rover travel and objects of prime scientific interest. Although Mars Orbiter Camera (MOC) images are of high enough resolution to distinguish the largest rocks (an extremely small population several meters diameter or larger), traditionally the abundance and distribution of rocks on Mars have been inferred from thermal inertia and radar measurements, our meager ground truth sampling of landing sites, and terrestrial rock populations. In this abstract, we explore the effective thermal inertia of rocks and rock populations, interpret the results in terms of abundances and populations of potentially hazardous rocks, and conclude with interpretations of rock hazards on the Martian surface and in extremely high thermal inertia areas.
Mercury and trace element contents of Donbas coals and associated mine water in the vicinity of Donetsk, Ukraine

USGS Publications Warehouse

Kolker, A.; Panov, B.S.; Panov, Y.B.; Landa, E.R.; Conko, K.M.; Korchemagin, V.A.; Shendrik, T.; McCord, J.D.

2009-01-01

Mercury-rich coals in the Donets Basin (Donbas region) of Ukraine were sampled in active underground mines to assess the levels of potentially harmful elements and the potential for dispersion of metals through use of this coal. For 29 samples representing c11 to m3 Carboniferous coals, mercury contents range from 0.02 to 3.5 ppm (whole-coal dry basis). Mercury is well correlated with pyritic sulfur (0.01 to 3.2 wt.%), with an r2 of 0.614 (one outlier excluded). Sulfides in these samples show enrichment of minor constituents in late-stage pyrite formed as a result of interaction of coal with hydrothermal fluids. Mine water sampled at depth and at surface collection points does not show enrichment of trace metals at harmful levels, indicating pyrite stability at subsurface conditions. Four samples of coal exposed in the defunct open-cast Nikitovka mercury mines in Gorlovka have extreme mercury contents of 12.8 to 25.5 ppm. This coal was formerly produced as a byproduct of extracting sandstone-hosted cinnabar ore. Access to these workings is unrestricted and small amounts of extreme mercury-rich coal are collected for domestic use, posing a limited human health hazard. More widespread hazards are posed by the abandoned Nikitovka mercury processing plant, the extensive mercury mine tailings, and mercury enrichment of soils extending into residential areas of Gorlovka.
Trends and Cost-Analysis of Lower Extremity Nerve Injury Using the National Inpatient Sample.

PubMed

Foster, Chase H; Karsy, Michael; Jensen, Michael R; Guan, Jian; Eli, Ilyas; Mahan, Mark A

2018-06-08

Peripheral nerve injuries (PNIs) of the lower extremities have been assessed in small cohort studies; however, the actual incidence, national trends, comorbidities, and cost of care in lower extremity PNI are not defined. Lack of sufficient data limits discussion on national policies, payors, and other aspects fundamental to the delivery of care in the US. To establish estimates of lower extremity PNIs incidence, associated diagnoses, and cost in the US using a comprehensive database with a minimum of a decade of data. The National Inpatient Sample was utilized to evaluate International Classification of Disease codes for specific lower extremity PNIs (9560-9568) between 2001 and 2013. Lower extremity PNIs occurred with a mean incidence of 13.3 cases per million population annually, which declined minimally from 2001 to 2013. The mean ± SEM age was 41.6 ± 0.1 yr; 61.1% of patients were males. Most were admitted via the emergency department (56.0%). PNIs occurred to the sciatic (16.6%), femoral (10.7%), tibial (6.0%), peroneal (33.4%), multiple nerves (1.3%), and other (32.0%). Associated diagnoses included lower extremity fracture (13.4%), complications of care (11.2%), open wounds (10.3%), crush injury (9.7%), and other (7.2%). Associated procedures included tibial fixation (23.3%), closure of skin (20.1%), debridement of open fractures (15.4%), fixation of other bones (13.5%), and wound debridement (14.5%). The mean annual unadjusted compounded growth rate of charges was 8.8%. The mean ± SEM annual charge over the time period was $64 031.20 ± $421.10, which was associated with the number of procedure codes (β = 0.2), length of stay (β = 0.6), and year (β = 0.1) in a multivariable analysis (P = .0001). These data describe associations in the treatment of lower extremity PNIs, which are important for considering national policies, costs, research and the delivery of care.
Small deformations of extreme five dimensional Myers-Perry black hole initial data

NASA Astrophysics Data System (ADS)

Alaee, Aghil; Kunduri, Hari K.

2015-02-01

We demonstrate the existence of a one-parameter family of initial data for the vacuum Einstein equations in five dimensions representing small deformations of the extreme Myers-Perry black hole. This initial data set has `' symmetry and preserves the angular momenta and horizon geometry of the extreme solution. Our proof is based upon an earlier result of Dain and Gabach-Clement concerning the existence of -invariant initial data sets which preserve the geometry of extreme Kerr (at least for short times). In addition, we construct a general class of transverse, traceless symmetric rank 2 tensors in these geometries.
Inferring modes of colonization for pest species using heterozygosity comparisons and a shared-allele test.

PubMed

Sved, J A; Yu, H; Dominiak, B; Gilchrist, A S

2003-02-01

Long-range dispersal of a species may involve either a single long-distance movement from a core population or spreading via unobserved intermediate populations. Where the new populations originate as small propagules, genetic drift may be extreme and gene frequency or assignment methods may not prove useful in determining the relation between the core population and outbreak samples. We describe computationally simple resampling methods for use in this situation to distinguish between the different modes of dispersal. First, estimates of heterozygosity can be used to test for direct sampling from the core population and to estimate the effective size of intermediate populations. Second, a test of sharing of alleles, particularly rare alleles, can show whether outbreaks are related to each other rather than arriving as independent samples from the core population. The shared-allele statistic also serves as a genetic distance measure that is appropriate for small samples. These methods were applied to data on a fruit fly pest species, Bactrocera tryoni, which is quarantined from some horticultural areas in Australia. We concluded that the outbreaks in the quarantine zone came from a heterogeneous set of genetically differentiated populations, possibly ones that overwinter in the vicinity of the quarantine zone.

Petrology and geochemistry of lithic fragments separated from the Apollo 15 deep-drill core

NASA Technical Reports Server (NTRS)

Lindstrom, M. M.; Nielsen, R. L.; Drake, M. J.

1977-01-01

Petrological and geochemical analysis of lithic fragments separated from the Apollo 15 deep-drill core showed these fragments to fall into the essentially the same range of rock types as observed in surface soil samples and large rock samples. Three particles are singled out as being of special interest. One sample is a mare basalt containing extremely evolved phases. The particle may represent small-scale imperfect crystal/liquid separation in a lava flow. A green glass particle is not the ultramafic emerald green glass described from the Apollo 15 site, but rather an ANT-like light green color, and has a quite different chemical composition from the ultramafic variety. One mare basalt displays a positive Eu anomaly and is enriched in plagioclase relative to olivine plus pyroxene.
Jimsphere wind and turbulence exceedance statistic

NASA Technical Reports Server (NTRS)

Adelfang, S. I.; Court, A.

1972-01-01

Exceedance statistics of winds and gusts observed over Cape Kennedy with Jimsphere balloon sensors are described. Gust profiles containing positive and negative departures, from smoothed profiles, in the wavelength ranges 100-2500, 100-1900, 100-860, and 100-460 meters were computed from 1578 profiles with four 41 weight digital high pass filters. Extreme values of the square root of gust speed are normally distributed. Monthly and annual exceedance probability distributions of normalized rms gust speeds in three altitude bands (2-7, 6-11, and 9-14 km) are log-normal. The rms gust speeds are largest in the 100-2500 wavelength band between 9 and 14 km in late winter and early spring. A study of monthly and annual exceedance probabilities and the number of occurrences per kilometer of level crossings with positive slope indicates significant variability with season, altitude, and filter configuration. A decile sampling scheme is tested and an optimum approach is suggested for drawing a relatively small random sample that represents the characteristic extreme wind speeds and shears of a large parent population of Jimsphere wind profiles.
A Fast Reduced Kernel Extreme Learning Machine.

PubMed

Deng, Wan-Yu; Ong, Yew-Soon; Zheng, Qing-Hua

2016-04-01

In this paper, we present a fast and accurate kernel-based supervised algorithm referred to as the Reduced Kernel Extreme Learning Machine (RKELM). In contrast to the work on Support Vector Machine (SVM) or Least Square SVM (LS-SVM), which identifies the support vectors or weight vectors iteratively, the proposed RKELM randomly selects a subset of the available data samples as support vectors (or mapping samples). By avoiding the iterative steps of SVM, significant cost savings in the training process can be readily attained, especially on Big datasets. RKELM is established based on the rigorous proof of universal learning involving reduced kernel-based SLFN. In particular, we prove that RKELM can approximate any nonlinear functions accurately under the condition of support vectors sufficiency. Experimental results on a wide variety of real world small instance size and large instance size applications in the context of binary classification, multi-class problem and regression are then reported to show that RKELM can perform at competitive level of generalized performance as the SVM/LS-SVM at only a fraction of the computational effort incurred. Copyright © 2015 Elsevier Ltd. All rights reserved.
Beating the curse of dimension with accurate statistics for the Fokker-Planck equation in complex turbulent systems.

PubMed

Chen, Nan; Majda, Andrew J

2017-12-05

Solving the Fokker-Planck equation for high-dimensional complex dynamical systems is an important issue. Recently, the authors developed efficient statistically accurate algorithms for solving the Fokker-Planck equations associated with high-dimensional nonlinear turbulent dynamical systems with conditional Gaussian structures, which contain many strong non-Gaussian features such as intermittency and fat-tailed probability density functions (PDFs). The algorithms involve a hybrid strategy with a small number of samples [Formula: see text], where a conditional Gaussian mixture in a high-dimensional subspace via an extremely efficient parametric method is combined with a judicious Gaussian kernel density estimation in the remaining low-dimensional subspace. In this article, two effective strategies are developed and incorporated into these algorithms. The first strategy involves a judicious block decomposition of the conditional covariance matrix such that the evolutions of different blocks have no interactions, which allows an extremely efficient parallel computation due to the small size of each individual block. The second strategy exploits statistical symmetry for a further reduction of [Formula: see text] The resulting algorithms can efficiently solve the Fokker-Planck equation with strongly non-Gaussian PDFs in much higher dimensions even with orders in the millions and thus beat the curse of dimension. The algorithms are applied to a [Formula: see text]-dimensional stochastic coupled FitzHugh-Nagumo model for excitable media. An accurate recovery of both the transient and equilibrium non-Gaussian PDFs requires only [Formula: see text] samples! In addition, the block decomposition facilitates the algorithms to efficiently capture the distinct non-Gaussian features at different locations in a [Formula: see text]-dimensional two-layer inhomogeneous Lorenz 96 model, using only [Formula: see text] samples. Copyright © 2017 the Author(s). Published by PNAS.
The Characteristics of Extreme Erosion Events in a Small Mountainous Watershed

PubMed Central

Fang, Nu-Fang; Shi, Zhi-Hua; Yue, Ben-Jiang; Wang, Ling

2013-01-01

A large amount of soil loss is caused by a small number of extreme events that are mainly responsible for the time compression of geomorphic processes. The aim of this study was to analyze suspended sediment transport during extreme erosion events in a mountainous watershed. Field measurements were conducted in Wangjiaqiao, a small agricultural watershed (16.7 km2) in the Three Gorges Area (TGA) of China. Continuous records were used to analyze suspended sediment transport regimes and assess the sediment loads of 205 rainfall–runoff events during a period of 16 hydrological years (1989–2004). Extreme events were defined as the largest events, ranked in order of their absolute magnitude (representing the 95th percentile). Ten extreme erosion events from 205 erosion events, representing 83.8% of the total suspended sediment load, were selected for study. The results of canonical discriminant analysis indicated that extreme erosion events are characterized by high maximum flood-suspended sediment concentrations, high runoff coefficients, and high flood peak discharge, which could possibly be explained by the transport of deposited sediment within the stream bed during previous events or bank collapses. PMID:24146898
Nonevaporable getter coating chambers for extreme high vacuum

DOE PAGES

Stutzman, Marcy L.; Adderley, Philip A.; Mamun, Md Abdullah Al; ...

2018-03-01

Techniques for NEG coating a large diameter chamber are presented along with vacuum measurements in the chamber using several pumping configurations, with base pressure as low as 1.56x10^-12 Torr (N2 equivalent) with only a NEG coating and small ion pump. We then describe modifications to the NEG coating process to coat complex geometry chambers for ultra-cold atom trap experiments. Surface analysis of NEG coated samples are used to measure composition and morphology of the thin films. Finally, pressure measurements are compared for two NEG coated polarized electron source chambers: the 130 kV polarized electron source at Jefferson Lab and themore » upgraded 350 kV polarized 2 electron source, both of which are approaching or within the extreme high vacuum (XHV) range, defined as P<7.5x10^-13 Torr.« less
Nonevaporable getter coating chambers for extreme high vacuum

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

Stutzman, Marcy L.; Adderley, Philip A.; Mamun, Md Abdullah Al

Techniques for NEG coating a large diameter chamber are presented along with vacuum measurements in the chamber using several pumping configurations, with base pressure as low as 1.56x10^-12 Torr (N2 equivalent) with only a NEG coating and small ion pump. We then describe modifications to the NEG coating process to coat complex geometry chambers for ultra-cold atom trap experiments. Surface analysis of NEG coated samples are used to measure composition and morphology of the thin films. Finally, pressure measurements are compared for two NEG coated polarized electron source chambers: the 130 kV polarized electron source at Jefferson Lab and themore » upgraded 350 kV polarized 2 electron source, both of which are approaching or within the extreme high vacuum (XHV) range, defined as P<7.5x10^-13 Torr.« less
Detection of small molecules with a flow immunosensor

NASA Technical Reports Server (NTRS)

Kusterbeck, Anne W.; Ligler, Frances S.

1991-01-01

We describe the development of an easy-to-use sensor with widespread applications for detecting small molecules. The flow immunosensor can analyze discrete samples in under one minute or continuously monitor a flowing stream for the presence of specific analytes. This detection system is extremely specific, and achieves a level of sensitivity which meets or exceeds the detection limits reported for rival assays. Because the system is also compact, transportable, and automated, it has the potential to impact diverse areas. For example, the flow immunosensor has successfully detected drugs of abuse and explosives, and may well address many of the needs of the environmental community with respect to continuous monitoring for pollutants. Efforts are underway to engineer a portable device in the field.
Extreme Temperature Performance of Automotive-Grade Small Signal Bipolar Junction Transistors

NASA Technical Reports Server (NTRS)

Boomer, Kristen; Damron, Benny; Gray, Josh; Hammoud, Ahmad

2018-01-01

Electronics designed for space exploration missions must display efficient and reliable operation under extreme temperature conditions. For example, lunar outposts, Mars rovers and landers, James Webb Space Telescope, Europa orbiter, and deep space probes represent examples of missions where extreme temperatures and thermal cycling are encountered. Switching transistors, small signal as well as power level devices, are widely used in electronic controllers, data instrumentation, and power management and distribution systems. Little is known, however, about their performance in extreme temperature environments beyond their specified operating range; in particular under cryogenic conditions. This report summarizes preliminary results obtained on the evaluation of commercial-off-the-shelf (COTS) automotive-grade NPN small signal transistors over a wide temperature range and thermal cycling. The investigations were carried out to establish a baseline on functionality of these transistors and to determine suitability for use outside their recommended temperature limits.
Effects of extreme climatic events on small-scale spatial patterns: a 20-year study of the distribution of a desert spider.

PubMed

Birkhofer, Klaus; Henschel, Joh; Lubin, Yael

2012-11-01

Individuals of most animal species are non-randomly distributed in space. Extreme climatic events are often ignored as potential drivers of distribution patterns, and the role of such events is difficult to assess. Seothyra henscheli (Araneae, Eresidae) is a sedentary spider found in the Namib dunes in Namibia. The spider constructs a sticky-edged silk web on the sand surface, connected to a vertical, silk-lined burrow. Above-ground web structures can be damaged by strong winds or heavy rainfall, and during dispersal spiders are susceptible to environmental extremes. Locations of burrows were mapped in three field sites in 16 out of 20 years from 1987 to 2007, and these grid-based data were used to identify the relationship between spatial patterns, climatic extremes and sampling year. According to Morisita's index, individuals had an aggregated distribution in most years and field sites, and Geary's C suggests clustering up to scales of 2 m. Individuals were more aggregated in years with high maximum wind speed and low annual precipitation. Our results suggest that clustering is a temporally stable property of populations that holds even under fluctuating burrow densities. Climatic extremes, however, affect the intensity of clustering behaviour: individuals seem to be better protected in field sites with many conspecific neighbours. We suggest that burrow-site selection is driven at least partly by conspecific cuing, and this behaviour may protect populations from collapse during extreme climatic events.
Infrared Studies of the Variability and Mass Loss of Dusty Asymptotic Giant Branch Stars in the Magellanic Clouds

NASA Astrophysics Data System (ADS)

Sargent, Benjamin; Groenewegen, M. A. T.

2018-01-01

The asymptotic giant branch (AGB) phase is one of the last phases of a star's life. AGB stars lose mass in an outflow in which dust condenses and is pushed away from the star. Extreme AGB stars are so named because their very red colors suggest very large amounts of dust, which in turn suggests extremely high mass loss rates. AGB stars also vary in brightness, and studies show that extreme AGB stars tend to have longer periods than other AGB stars and are more likely to be fundamental mode pulsators than other AGB stars. Extreme AGB stars are difficult to study, as their colors are so red due to their copious amounts of circumstellar dust that they are often not detected at optical wavelengths. Therefore, they must be observed at infrared wavelengths to explore their variability. Using the Spitzer Space Telescope, my team and I have observed a sample of extreme AGB stars in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) over Cycles 9 through 12 during the Warm Spitzer mission. For each cycle, we typically observed a set of extreme AGB stars at both 3.6 and 4.5 microns wavelength approximately monthly for most of a year. These observations reveal a wide range of variability properties. I present results from our analysis of the data obtained from these Spitzer variability programs, including light curve analyses and comparison to period-luminosity diagrams. Funding is acknowledged from JPL RSA # 1561703.
Air sampling with solid phase microextraction

NASA Astrophysics Data System (ADS)

Martos, Perry Anthony

There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds. With 300 seconds sampling, the formaldehyde detection limit was 2.1 ppbv, better than any other 5 minute sampling device for formaldehyde. The first-order rate constant for product formation was used to quantify formaldehyde concentrations without a calibration curve. This spot sampler was used to sample the headspace of hair gel, particle board, plant material and coffee grounds for formaldehyde, and other carbonyl compounds, with extremely promising results. The SPME sampling devices were also used for time- weighted average sampling (30 minutes to 16 hours). Finally, the four new SPME air sampling methods were field tested with side-by-side comparisons to standard air sampling methods, showing a tremendous use of SPME as an air sampler.
Extreme Mean and Its Applications

NASA Technical Reports Server (NTRS)

Swaroop, R.; Brownlow, J. D.

1979-01-01

Extreme value statistics obtained from normally distributed data are considered. An extreme mean is defined as the mean of p-th probability truncated normal distribution. An unbiased estimate of this extreme mean and its large sample distribution are derived. The distribution of this estimate even for very large samples is found to be nonnormal. Further, as the sample size increases, the variance of the unbiased estimate converges to the Cramer-Rao lower bound. The computer program used to obtain the density and distribution functions of the standardized unbiased estimate, and the confidence intervals of the extreme mean for any data are included for ready application. An example is included to demonstrate the usefulness of extreme mean application.
Bayes plus Brass: Estimating Total Fertility for Many Small Areas from Sparse Census Data

PubMed Central

Schmertmann, Carl P.; Cavenaghi, Suzana M.; Assunção, Renato M.; Potter, Joseph E.

2013-01-01

Small-area fertility estimates are valuable for analysing demographic change, and important for local planning and population projection. In countries lacking complete vital registration, however, small-area estimates are possible only from sparse survey or census data that are potentially unreliable. Such estimation requires new methods for old problems: procedures must be automated if thousands of estimates are required, they must deal with extreme sampling variability in many areas, and they should also incorporate corrections for possible data errors. We present a two-step algorithm for estimating total fertility in such circumstances, and we illustrate by applying the method to 2000 Brazilian Census data for over five thousand municipalities. Our proposed algorithm first smoothes local age-specific rates using Empirical Bayes methods, and then applies a new variant of Brass’s P/F parity correction procedure that is robust under conditions of rapid fertility decline. PMID:24143946
Cannabis, motivation, and life satisfaction in an internet sample

PubMed Central

Barnwell, Sara Smucker; Earleywine, Mitch; Wilcox, Rand

2006-01-01

Although little evidence supports cannabis-induced amotivational syndrome, sources continue to assert that the drug saps motivation [1], which may guide current prohibitions. Few studies report low motivation in chronic users; another reveals that they have higher subjective wellbeing. To assess differences in motivation and subjective wellbeing, we used a large sample (N = 487) and strict definitions of cannabis use (7 days/week) and abstinence (never). Standard statistical techniques showed no differences. Robust statistical methods controlling for heteroscedasticity, non-normality and extreme values found no differences in motivation but a small difference in subjective wellbeing. Medical users of cannabis reporting health problems tended to account for a significant portion of subjective wellbeing differences, suggesting that illness decreased wellbeing. All p-values were above p = .05. Thus, daily use of cannabis does not impair motivation. Its impact on subjective wellbeing is small and may actually reflect lower wellbeing due to medical symptoms rather than actual consumption of the plant. PMID:16722561
Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors

USGS Publications Warehouse

Barnhardt, W.A.; Kelley, J.T.; Dickson, S.M.; Belknap, D.F.

1998-01-01

The bedrock-framed seafloor in the northwestern Gulf of Maine is characterized by extreme changes in bathymetric relief and covered with a wide variety of surficial materials. Traditional methods of mapping cannot accurately represent the great heterogeneity of such a glaciated region. A new mapping scheme for complex seafloors, based primarily on the interpretation of side-scan sonar imagery, utilizes four easily recognized units: rock, gravel, sand and mud. In many places, however, the seafloor exhibits a complicated mixture or extremely 'patchy' distribution of the four basic units, which are too small to map individually. Twelve composite units, each a two-component mixture of the basic units, were established to represent this patchiness at a small scale (1:100,000). Using a geographic information system, these and all other available data (seismic profiles, grab samples, submersible dives and cores) were referenced to a common geographic base, superimposed on bathymetric contours and then integrated into surficial geologic maps of the regional inner continental shelf. This digital representation of the seafloor comprises a multidimensional, interactive model complete with explicit attributes (depth, bottom type) that allow for detailed analysis of marine environments.
Diversity of Heterotrophic Protists from Extremely Hypersaline Habitats.

PubMed

Park, Jong Soo; Simpson, Alastair G B

2015-09-01

Heterotrophic protists (protozoa) are a diverse but understudied component of the biota of extremely hypersaline environments, with few data on molecular diversity within halophile 'species', and almost nothing known of their biogeographic distribution. We have garnered SSU rRNA gene sequences for several clades of halophilic protozoa from enrichments from waters of >12.5% salinity from Australia, North America, and Europe (6 geographic sites, 25 distinct samples). The small stramenopile Halocafeteria was found at all sites, but phylogenies did not show clear geographic clustering. The ciliate Trimyema was recorded from 6 non-European samples. Phylogenies confirmed a monophyletic halophilic Trimyema group that included possible south-eastern Australian, Western Australian and North American clusters. Several halophilic Heterolobosea were detected, demonstrating that Pleurostomum contains at least three relatively distinct clades, and increasing known continental ranges for Tulamoeba peronaphora and Euplaesiobystra hypersalinica. The unclassified flagellate Palustrimonas, found in one Australian sample, proves to be a novel deep-branching alveolate. These results are consistent with a global distribution of halophilic protozoa groups (∼ morphospecies), but the Trimyema case suggests that is worth testing whether larger forms exhibit biogeographic phylogenetic substructure. The molecular detection/characterization of halophilic protozoa is still far from complete at the clade level, let alone the 'species level'. Copyright © 2015 Elsevier GmbH. All rights reserved.
Closing the Gap: An Analysis of Options for Improving the USAF Fighter Fleet from 2105 to 2035

DTIC Science & Technology

2015-10-01

capacity. The CBO predicts an increase in capacity for both large, or 2000 lbs class weapons, and small , either 500 lbs class or Small Diameter Bomb ...Laser Guided Bomb (LGB) designed to penetrate extremely hardened bunkers with extreme accuracy.54 Larger weapons can provide better standoff range...operate with impunity in low intensity CAS scenarios. While survivability, with the exception of against small arms ground fire, is far less a
An emerging population of BL Lacs with extreme properties: towards a class of EBL and cosmic magnetic field probes?

NASA Astrophysics Data System (ADS)

Bonnoli, G.; Tavecchio, F.; Ghisellini, G.; Sbarrato, T.

2015-07-01

High-energy observations of extreme BL Lac objects, such as 1ES 0229+200 or 1ES 0347-121, recently focused interest both for blazar and jet physics and for the implication on the extragalactic background light and intergalactic magnetic field estimate. However, the number of these extreme highly peaked BL Lac objects (EHBL) is still rather small. Aiming at increase their number, we selected a group of EHBL candidates starting from the BL Lac sample of Plotkin et al. (2011), considering those undetected (or only barely detected) by the Large Area Telescope onboard Fermi and characterized by a high X-ray versus radio flux ratio. We assembled the multiwavelength spectral energy distribution of the resulting nine sources, profiting of publicly available archival observations performed by Swift, GALEX, and Fermi satellites, confirming their nature. Through a simple one-zone synchrotron self-Compton model we estimate the expected very high energy flux, finding that in the majority of cases it is within the reach of present generation of Cherenkov arrays or of the forthcoming Cherenkov Telescope Array.
Unlocking the Barite Paleoproductivity Proxy: Using a New Barite Extraction Method to Understand Productivity Trends During the Eocene Greenhouse

NASA Astrophysics Data System (ADS)

House, B. M.; Norris, R. D.

2017-12-01

The Early Eocene Climatic Optimum (EECO) around 50 Ma was a sustained period of extreme global warmth with ocean bottom water temperatures of up to 12° C. The marine biologic response to such climatic extremes is unclear, however, in part because proxies that integrate ecosystem-wide productivity signals are scarce. While the accumulation of marine barite (BaSO4) is one such proxy, its applicability has remained limited due to the difficulty in reliably quantifying barite. Discrete measurements of barite content in marine sediments are laborious, and indirect estimates provide unclear results. We have developed a fast, high-throughput method for reliable measurement of barite content that relies on selective extraction of barite rather than sample digestion and quantification of remaining barite. Tests of the new method reveal that it gives the expected results for a wide variety of sediment types and can quantitatively extract 10-100 times the amount of barite typically encountered in natural sediments. Altogether, our method provides an estimated ten-fold increase in analysis efficiency over current sample digestion methods and also works reliably on small ( 1 g or less) sediment samples. Furthermore, the instrumentation requirements of this method are minor, so samples can be analyzed in shipboard labs to generate real-time paleoproductivity records during coring expeditions. Because of the magnitude of throughput improvement, this new technique will permit the generation of large datasets needed to address previously intractable paleoclimate and paleoceanographic questions. One such question is how export productivity changes during climatic extremes. We used our new method to analyze globally distributed sediment cores to determine if the EECO represented a period of anomalous export productivity either due to higher rates of primary production or more vigorous heterotrophic metabolisms. An increase in export productivity could provide a mechanism for exiting periods of extreme warmth, and understanding the interplay between temperature, atmospheric CO2 levels, and export productivity during the EECO will help clarify how the marine biologic system functions as a whole.

THE PASSAGE OF MARKED IONS INTO TISSUES AND FLUIDS OF THE REPRODUCTIVE TRACT OF PREGNANT RABBITS

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

Bennett, J.P.; Boursnell, J.C.; Lutwak-Mann, C.

1959-10-31

Rapid changes were demonstrated in the uptake of labeled ions both in the developing embryo and in the endometrium, mesodermal placental folds, and other closely associated tissues and fluids following the intravenous injection of labeled ions in pregnant rabbits. Phosphorus-32, sulfur-85, sodium-24, iodine- 131, and potassium-42 were used as tracers. A number of new techniques were developed to obtain, weigh, and handle the extremely small samples. The influence of exogenous materials on the early development of fetuses is discussed briefly. (C.R.)
Three-dimensional nanoscale molecular imaging by extreme ultraviolet laser ablation mass spectrometry

PubMed Central

Kuznetsov, Ilya; Filevich, Jorge; Dong, Feng; Woolston, Mark; Chao, Weilun; Anderson, Erik H.; Bernstein, Elliot R.; Crick, Dean C.; Rocca, Jorge J.; Menoni, Carmen S.

2015-01-01

Analytical probes capable of mapping molecular composition at the nanoscale are of critical importance to materials research, biology and medicine. Mass spectral imaging makes it possible to visualize the spatial organization of multiple molecular components at a sample's surface. However, it is challenging for mass spectral imaging to map molecular composition in three dimensions (3D) with submicron resolution. Here we describe a mass spectral imaging method that exploits the high 3D localization of absorbed extreme ultraviolet laser light and its fundamentally distinct interaction with matter to determine molecular composition from a volume as small as 50 zl in a single laser shot. Molecular imaging with a lateral resolution of 75 nm and a depth resolution of 20 nm is demonstrated. These results open opportunities to visualize chemical composition and chemical changes in 3D at the nanoscale. PMID:25903827
Significance of noisy signals in periodograms

NASA Astrophysics Data System (ADS)

Süveges, Maria

2015-08-01

The detection of tiny periodic signals in noisy and irregularly sampled time series is a challenging task. Once a small peak is found in the periodogram, the next step is to see how probable it is that pure noise produced a peak so extreme - that is to say, compute its False Alarm Probability (FAP). This useful measure quantifies the statistical plausibility of the found signal among the noise. However, its derivation from statistical principles is very hard due to the specificities of astronomical periodograms, such as oversampling and the ensuing strong correlation among its values at different frequencies. I will present a method to compute the FAP based on extreme-value statistics (Süveges 2014), and compare it to two other methods proposed by Baluev (2008) and Paltani (2004) and Schwarzenberg-Czerny (2012) on signals with various signal shapes and at different signal-to-noise ratios.
Inferring modes of colonization for pest species using heterozygosity comparisons and a shared-allele test.

PubMed Central

Sved, J A; Yu, H; Dominiak, B; Gilchrist, A S

2003-01-01

Long-range dispersal of a species may involve either a single long-distance movement from a core population or spreading via unobserved intermediate populations. Where the new populations originate as small propagules, genetic drift may be extreme and gene frequency or assignment methods may not prove useful in determining the relation between the core population and outbreak samples. We describe computationally simple resampling methods for use in this situation to distinguish between the different modes of dispersal. First, estimates of heterozygosity can be used to test for direct sampling from the core population and to estimate the effective size of intermediate populations. Second, a test of sharing of alleles, particularly rare alleles, can show whether outbreaks are related to each other rather than arriving as independent samples from the core population. The shared-allele statistic also serves as a genetic distance measure that is appropriate for small samples. These methods were applied to data on a fruit fly pest species, Bactrocera tryoni, which is quarantined from some horticultural areas in Australia. We concluded that the outbreaks in the quarantine zone came from a heterogeneous set of genetically differentiated populations, possibly ones that overwinter in the vicinity of the quarantine zone. PMID:12618417
Evaluation of the DSM-5 severity indicator for binge eating disorder in a clinical sample

PubMed Central

Grilo, Carlos M.; Ivezaj, Valentina; White, Marney A.

2015-01-01

Objective This study tested the new DSM-5 severity criterion for binge eating disorder (BED) based on frequency of binge-eating in a clinical sample. This study also tested overvaluation of shape/weight as an alternative severity specifier. Method Participants were 834 treatment-seeking adults diagnosed with DSM-5 BED using semistructured diagnostic and eating-disorder interviews. Participants sub-grouped based on DSM-5 severity levels and on overvaluation of shape/weight were compared on demographic and clinical variables. Results Based on DSM-5 severity definitions, 331 (39.7%) participants were categorized as mild, 395 (47.5%) as moderate, 83 (10.0%) as severe, and 25 (3.0%) as extreme. Analyses comparing three (mild, moderate, and severe/extreme) severity groups revealed no significant differences in demographic variables or body mass index (BMI). Analyses revealed significantly higher eating-disorder psychopathology in the severe/extreme than moderate and mild groups and higher depression in moderate and severe/extreme groups than the mild group; effect sizes were small. Participants characterized with overvaluation (N = 449; 54%) versus without overvaluation (N = 384; 46%) did not differ significantly in age, sex, BMI, or binge-eating frequency, but had significantly greater eating-disorder psychopathology and depression. The robustly greater eating-disorder psychopathology and depression levels (medium-to-large effect sizes) in the overvaluation group was observed without attenuation of effect sizes after adjusting for ethnicity/race and binge-eating severity/frequency. Conclusions Our findings provide support for overvaluation of shape/weight as a severity specifier for BED as it provides stronger information about the severity of homogeneous groupings of patients than the DSM-5 rating based on binge-eating. PMID:26114779
Slice sampling technique in Bayesian extreme of gold price modelling

NASA Astrophysics Data System (ADS)

Rostami, Mohammad; Adam, Mohd Bakri; Ibrahim, Noor Akma; Yahya, Mohamed Hisham

2013-09-01

In this paper, a simulation study of Bayesian extreme values by using Markov Chain Monte Carlo via slice sampling algorithm is implemented. We compared the accuracy of slice sampling with other methods for a Gumbel model. This study revealed that slice sampling algorithm offers more accurate and closer estimates with less RMSE than other methods . Finally we successfully employed this procedure to estimate the parameters of Malaysia extreme gold price from 2000 to 2011.
Rare Event Simulation in Radiation Transport

NASA Astrophysics Data System (ADS)

Kollman, Craig

This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiplied by the likelihood ratio between the true and simulated probabilities so as to keep our estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive "learning" algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give, with probability one, a sequence of estimates converging exponentially fast to the true solution. In the final chapter, an attempt to generalize this algorithm to a continuous state space is made. This involves partitioning the space into a finite number of cells. There is a tradeoff between additional computation per iteration and variance reduction per iteration that arises in determining the optimal grid size. All versions of this algorithm can be thought of as a compromise between deterministic and Monte Carlo methods, capturing advantages of both techniques.
Field-induced dielectric response saturation in $o$ -TaS 3

DOE PAGES

Ma, Yongchang; Lu, Cuimin; Wang, Xuewei; ...

2016-08-03

The temperature and electric field dependent conductivity spectra of o-TaS 3 sample with 10 μm 2 in cross section were measured. Besides the classical electric threshold E T₋Cl, we observed another novel threshold E T₋N at a larger electric field, where an S-shaped I-V relation revealed. The appearance of E T₋N may be due to the establishment of coherence among small charge-density- wave domains. Under a stable field E > E T-N, a sharp dispersion emerged below kHz. At a fixed temperature, the scattering rate of the charged condensate was extremely small and decreased with increasing field. With decreasing temperature,more » the scattering Fröhlic-mode conductivity would be consistent with the meta-stable state.« less
Robot-assisted upper extremity rehabilitation for cervical spinal cord injuries: a systematic scoping review.

PubMed

Singh, Hardeep; Unger, Janelle; Zariffa, José; Pakosh, Maureen; Jaglal, Susan; Craven, B Catharine; Musselman, Kristin E

2018-01-15

Abstact Purpose: To provide an overview of the feasibility and outcomes of robotic-assisted upper extremity training for individuals with cervical spinal cord injury (SCI), and to identify gaps in current research and articulate future research directions. A systematic search was conducted using Medline, Embase, PsycINFO, CCTR, CDSR, CINAHL and PubMed on June 7, 2017. Search terms included 3 themes: (1) robotics; (2) SCI; (3) upper extremity. Studies using robots for upper extremity rehabilitation among individuals with cervical SCI were included. Identified articles were independently reviewed by two researchers and compared to pre-specified criteria. Disagreements regarding article inclusion were resolved through discussion. The modified Downs and Black checklist was used to assess article quality. Participant characteristics, study and intervention details, training outcomes, robot features, study limitations and recommendations for future studies were abstracted from included articles. Twelve articles (one randomized clinical trial, six case series, five case studies) met the inclusion criteria. Five robots were exoskeletons and three were end-effectors. Sample sizes ranged from 1 to 17 subjects. Articles had variable quality, with quality scores ranging from 8 to 20. Studies had a low internal validity primarily from lack of blinding or a control group. Individuals with mild-moderate impairments showed the greatest improvements on body structure/function and performance-level measures. This review is limited by the small number of articles, low-sample sizes and the diversity of devices and their associated training protocols, and outcome measures. Preliminary evidence suggests robot-assisted interventions are safe, feasible and can reduce active assistance provided by therapists. Implications for rehabilitation Robot-assisted upper extremity training for individuals with cervical spinal cord injury is safe, feasible and can reduce hands-on assistance provided by therapists. Future research in robotics rehabilitation with individuals with spinal cord injury is needed to determine the optimal device and training protocol as well as effectiveness.
Exploring EUV Spicules Using 304 Angstrom He II Data from SDO AIA

NASA Technical Reports Server (NTRS)

Snyder, Ian R.; Sterling, Alphonse C.; Falconer, David A.; Moore, Ron L.

2014-01-01

We present results from a statistical study of He II 304 Angstrom Extreme Ultraviolet (EUV) spicules at the limb of the Sun. We also measured properties of one macrospicule; macrospicules are longer than most spicules, and much broader in width than spicules. We use high-cadence (12 second) and high-resolution (0.6 arcseconds pixels) resolution data from the Atmospheric Imaging Array (AIA) instrument on the Solar Dynamic Observatory (SDO). All of the observed events occurred near the solar north pole, where quiet Sun or coronal hole environments ensued. We examined the maximum lengths, maximum rise velocities, and lifetimes of 33 Extreme Ultraviolet (EUV) spicules and the macrospicule. For the bulk of the Extreme Ultraviolet (EUV) spicules these quantities are, respectively, approximately 10,000-40,000 kilometers, 20-100 kilometers per second, and approximately 100- approximately 1000 seconds. For the macrospicule the corresponding quantities were respectively approximately 60,000 kilometers, approximately 130 kilometers per second, approximately 1800 seconds, which is typical of macrospicules measured by other workers. Therefore macrospicules are taller, longer-lived, and faster than most Extreme Ultraviolet (EUV) spicules. The rise profiles of both the spicules and the macrospicules match well a second-order ("parabolic" ) trajectory, although the acceleration was often weaker than that of solar gravity in the profiles fitted to the trajectories. Our macrospicule also had an obvious brightening at its base at birth, while such brightening was not apparent for the Extreme Ultraviolet (EUV) spicules. Most of the Extreme Ultraviolet (EUV) spicules remained visible during their descent back to the solar surface, although a small percentage of the spicules and the macrospicule faded out before falling back to the surface. Our sample of macrospicules is not yet large enough to determine whether their initiation mechanism is identical to that of Extreme Ultraviolet (EUV) spicules.
Optimizing Illumina next-generation sequencing library preparation for extremely AT-biased genomes.

PubMed

Oyola, Samuel O; Otto, Thomas D; Gu, Yong; Maslen, Gareth; Manske, Magnus; Campino, Susana; Turner, Daniel J; Macinnis, Bronwyn; Kwiatkowski, Dominic P; Swerdlow, Harold P; Quail, Michael A

2012-01-03

Massively parallel sequencing technology is revolutionizing approaches to genomic and genetic research. Since its advent, the scale and efficiency of Next-Generation Sequencing (NGS) has rapidly improved. In spite of this success, sequencing genomes or genomic regions with extremely biased base composition is still a great challenge to the currently available NGS platforms. The genomes of some important pathogenic organisms like Plasmodium falciparum (high AT content) and Mycobacterium tuberculosis (high GC content) display extremes of base composition. The standard library preparation procedures that employ PCR amplification have been shown to cause uneven read coverage particularly across AT and GC rich regions, leading to problems in genome assembly and variation analyses. Alternative library-preparation approaches that omit PCR amplification require large quantities of starting material and hence are not suitable for small amounts of DNA/RNA such as those from clinical isolates. We have developed and optimized library-preparation procedures suitable for low quantity starting material and tolerant to extremely high AT content sequences. We have used our optimized conditions in parallel with standard methods to prepare Illumina sequencing libraries from a non-clinical and a clinical isolate (containing ~53% host contamination). By analyzing and comparing the quality of sequence data generated, we show that our optimized conditions that involve a PCR additive (TMAC), produces amplified libraries with improved coverage of extremely AT-rich regions and reduced bias toward GC neutral templates. We have developed a robust and optimized Next-Generation Sequencing library amplification method suitable for extremely AT-rich genomes. The new amplification conditions significantly reduce bias and retain the complexity of either extremes of base composition. This development will greatly benefit sequencing clinical samples that often require amplification due to low mass of DNA starting material.
Extreme event statistics in a drifting Markov chain

NASA Astrophysics Data System (ADS)

Kindermann, Farina; Hohmann, Michael; Lausch, Tobias; Mayer, Daniel; Schmidt, Felix; Widera, Artur

2017-07-01

We analyze extreme event statistics of experimentally realized Markov chains with various drifts. Our Markov chains are individual trajectories of a single atom diffusing in a one-dimensional periodic potential. Based on more than 500 individual atomic traces we verify the applicability of the Sparre Andersen theorem to our system despite the presence of a drift. We present detailed analysis of four different rare-event statistics for our system: the distributions of extreme values, of record values, of extreme value occurrence in the chain, and of the number of records in the chain. We observe that, for our data, the shape of the extreme event distributions is dominated by the underlying exponential distance distribution extracted from the atomic traces. Furthermore, we find that even small drifts influence the statistics of extreme events and record values, which is supported by numerical simulations, and we identify cases in which the drift can be determined without information about the underlying random variable distributions. Our results facilitate the use of extreme event statistics as a signal for small drifts in correlated trajectories.
Rainfall extremes from TRMM data and the Metastatistical Extreme Value Distribution

NASA Astrophysics Data System (ADS)

Zorzetto, Enrico; Marani, Marco

2017-04-01

A reliable quantification of the probability of weather extremes occurrence is essential for designing resilient water infrastructures and hazard mitigation measures. However, it is increasingly clear that the presence of inter-annual climatic fluctuations determines a substantial long-term variability in the frequency of occurrence of extreme events. This circumstance questions the foundation of the traditional extreme value theory, hinged on stationary Poisson processes or on asymptotic assumptions to derive the Generalized Extreme Value (GEV) distribution. We illustrate here, with application to daily rainfall, a new approach to extreme value analysis, the Metastatistical Extreme Value Distribution (MEVD). The MEVD relaxes the above assumptions and is based on the whole distribution of daily rainfall events, thus allowing optimal use of all available observations. Using a global dataset of rain gauge observations, we show that the MEVD significantly outperforms the Generalized Extreme Value distribution, particularly for long average recurrence intervals and when small samples are available. The latter property suggests MEVD to be particularly suited for applications to satellite rainfall estimates, which only cover two decades, thus making extreme value estimation extremely challenging. Here we apply MEVD to the TRMM TMPA 3B42 product, an 18-year dataset of remotely-sensed daily rainfall providing a quasi-global coverage. Our analyses yield a global scale mapping of daily rainfall extremes and of their distributional tail properties, bridging the existing large gaps in ground-based networks. Finally, we illustrate how our global-scale analysis can provide insight into how properties of local rainfall regimes affect tail estimation uncertainty when using the GEV or MEVD approach. We find a dependence of the estimation uncertainty, for both the GEV- and MEV-based approaches, on the average annual number and on the inter-annual variability of rainy days. In particular, estimation uncertainty decreases 1) as the mean annual number of wet days increases, and 2) as the variability in the number of rainy days, expressed by its coefficient of variation, decreases. We tentatively explain this behavior in terms of the assumptions underlying the two approaches.
Comparison of Bootstrapping and Markov Chain Monte Carlo for Copula Analysis of Hydrological Droughts

NASA Astrophysics Data System (ADS)

Yang, P.; Ng, T. L.; Yang, W.

2015-12-01

Effective water resources management depends on the reliable estimation of the uncertainty of drought events. Confidence intervals (CIs) are commonly applied to quantify this uncertainty. A CI seeks to be at the minimal length necessary to cover the true value of the estimated variable with the desired probability. In drought analysis where two or more variables (e.g., duration and severity) are often used to describe a drought, copulas have been found suitable for representing the joint probability behavior of these variables. However, the comprehensive assessment of the parameter uncertainties of copulas of droughts has been largely ignored, and the few studies that have recognized this issue have not explicitly compared the various methods to produce the best CIs. Thus, the objective of this study to compare the CIs generated using two widely applied uncertainty estimation methods, bootstrapping and Markov Chain Monte Carlo (MCMC). To achieve this objective, (1) the marginal distributions lognormal, Gamma, and Generalized Extreme Value, and the copula functions Clayton, Frank, and Plackett are selected to construct joint probability functions of two drought related variables. (2) The resulting joint functions are then fitted to 200 sets of simulated realizations of drought events with known distribution and extreme parameters and (3) from there, using bootstrapping and MCMC, CIs of the parameters are generated and compared. The effect of an informative prior on the CIs generated by MCMC is also evaluated. CIs are produced for different sample sizes (50, 100, and 200) of the simulated drought events for fitting the joint probability functions. Preliminary results assuming lognormal marginal distributions and the Clayton copula function suggest that for cases with small or medium sample sizes (~50-100), MCMC to be superior method if an informative prior exists. Where an informative prior is unavailable, for small sample sizes (~50), both bootstrapping and MCMC yield the same level of performance, and for medium sample sizes (~100), bootstrapping is better. For cases with a large sample size (~200), there is little difference between the CIs generated using bootstrapping and MCMC regardless of whether or not an informative prior exists.
Interpreting survival data from clinical trials of surgery versus stereotactic body radiation therapy in operable Stage I non-small cell lung cancer patients.

PubMed

Samson, Pamela; Keogan, Kathleen; Crabtree, Traves; Colditz, Graham; Broderick, Stephen; Puri, Varun; Meyers, Bryan

2017-01-01

To identify the variability of short- and long-term survival outcomes among closed Phase III randomized controlled trials with small sample sizes comparing SBRT (stereotactic body radiation therapy) and surgical resection in operable clinical Stage I non-small cell lung cancer (NSCLC) patients. Clinical Stage I NSCLC patients who underwent surgery at our institution meeting the inclusion/exclusion criteria for STARS (Randomized Study to Compare CyberKnife to Surgical Resection in Stage I Non-small Cell Lung Cancer), ROSEL (Trial of Either Surgery or Stereotactic Radiotherapy for Early Stage (IA) Lung Cancer), or both were identified. Bootstrapping analysis provided 10,000 iterations to depict 30-day mortality and three-year overall survival (OS) in cohorts of 16 patients (to simulate the STARS surgical arm), 27 patients (to simulate the pooled surgical arms of STARS and ROSEL), and 515 (to simulate the goal accrual for the surgical arm of STARS). From 2000 to 2012, 749/873 (86%) of clinical Stage I NSCLC patients who underwent resection were eligible for STARS only, ROSEL only, or both studies. When patients eligible for STARS only were repeatedly sampled with a cohort size of 16, the 3-year OS rates ranged from 27 to 100%, and 30-day mortality varied from 0 to 25%. When patients eligible for ROSEL or for both STARS and ROSEL underwent bootstrapping with n=27, the 3-year OS ranged from 46 to 100%, while 30-day mortality varied from 0 to 15%. Finally, when patients eligible for STARS were repeatedly sampled in groups of 515, 3-year OS narrowed to 70-85%, with 30-day mortality varying from 0 to 4%. Short- and long-term survival outcomes from trials with small sample sizes are extremely variable and unreliable for extrapolation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
76 FR 29251 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls; Guidance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-20

...: Topical Oxygen Chamber for Extremities; Availability; Correction AGENCY: Food and Drug Administration, HHS... Special Controls Guidance Documents: Topical Oxygen Chamber for Extremities.'' The document published... Oxygen Chamber for Extremities'' to the Division of Small Manufacturers, International, and Consumer...
Monitoring Cellular Events in Living Mast Cells Stimulated with an Extremely Small Amount of Fluid on a Microchip

NASA Astrophysics Data System (ADS)

Munaka, Tatsuya; Abe, Hirohisa; Kanai, Masaki; Sakamoto, Takashi; Nakanishi, Hiroaki; Yamaoka, Tetsuji; Shoji, Shuichi; Murakami, Akira

2006-07-01

We successfully developed a measurement system for real-time analysis of cellular function using a newly designed microchip. This microchip was equipped with a micro cell incubation chamber (240 nl) and was stimulated by a very small amount of stimuli (as small as 24 nl). Using the microchip system, cultivation of mast cells was successfully carried out. Monitoring of the cellular events after stimulation with an extremely small amount of fluid on a microchip was performed. This system could be applicable for various types of cellular analysis including real-time monitoring of cellular response by stimulation.
EPS-LASSO: Test for High-Dimensional Regression Under Extreme Phenotype Sampling of Continuous Traits.

PubMed

Xu, Chao; Fang, Jian; Shen, Hui; Wang, Yu-Ping; Deng, Hong-Wen

2018-01-25

Extreme phenotype sampling (EPS) is a broadly-used design to identify candidate genetic factors contributing to the variation of quantitative traits. By enriching the signals in extreme phenotypic samples, EPS can boost the association power compared to random sampling. Most existing statistical methods for EPS examine the genetic factors individually, despite many quantitative traits have multiple genetic factors underlying their variation. It is desirable to model the joint effects of genetic factors, which may increase the power and identify novel quantitative trait loci under EPS. The joint analysis of genetic data in high-dimensional situations requires specialized techniques, e.g., the least absolute shrinkage and selection operator (LASSO). Although there are extensive research and application related to LASSO, the statistical inference and testing for the sparse model under EPS remain unknown. We propose a novel sparse model (EPS-LASSO) with hypothesis test for high-dimensional regression under EPS based on a decorrelated score function. The comprehensive simulation shows EPS-LASSO outperforms existing methods with stable type I error and FDR control. EPS-LASSO can provide a consistent power for both low- and high-dimensional situations compared with the other methods dealing with high-dimensional situations. The power of EPS-LASSO is close to other low-dimensional methods when the causal effect sizes are small and is superior when the effects are large. Applying EPS-LASSO to a transcriptome-wide gene expression study for obesity reveals 10 significant body mass index associated genes. Our results indicate that EPS-LASSO is an effective method for EPS data analysis, which can account for correlated predictors. The source code is available at https://github.com/xu1912/EPSLASSO. hdeng2@tulane.edu. Supplementary data are available at Bioinformatics online. © The Author (2018). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Enhanced strength and temperature dependence of mechanical properties of Li at small scales and its implications for Li metal anodes

NASA Astrophysics Data System (ADS)

Xu, Chen; Ahmad, Zeeshan; Aryanfar, Asghar; Viswanathan, Venkatasubramanian; Greer, Julia R.

2017-01-01

Most next-generation Li ion battery chemistries require a functioning lithium metal (Li) anode. However, its application in secondary batteries has been inhibited because of uncontrollable dendrite growth during cycling. Mechanical suppression of dendrite growth through solid polymer electrolytes (SPEs) or through robust separators has shown the most potential for alleviating this problem. Studies of the mechanical behavior of Li at any length scale and temperature are limited because of its extreme reactivity, which renders sample preparation, transfer, microstructure characterization, and mechanical testing extremely challenging. We conduct nanomechanical experiments in an in situ scanning electron microscope and show that micrometer-sized Li attains extremely high strengths of 105 MPa at room temperature and of 35 MPa at 90 °C. We demonstrate that single-crystalline Li exhibits a power-law size effect at the micrometer and submicrometer length scales, with the strengthening exponent of -0.68 at room temperature and of -1.00 at 90 °C. We also report the elastic and shear moduli as a function of crystallographic orientation gleaned from experiments and first-principles calculations, which show a high level of anisotropy up to the melting point, where the elastic and shear moduli vary by a factor of ˜4 between the stiffest and most compliant orientations. The emergence of such high strengths in small-scale Li and sensitivity of this metal’s stiffness to crystallographic orientation help explain why the existing methods of dendrite suppression have been mainly unsuccessful and have significant implications for practical design of future-generation batteries.
Extremism without extremists: Deffuant model with emotions

NASA Astrophysics Data System (ADS)

Sobkowicz, Pawel

2015-03-01

The frequent occurrence of extremist views in many social contexts, often growing from small minorities to almost total majority, poses a significant challenge for democratic societies. The phenomenon can be described within the sociophysical paradigm. We present a modified version of the continuous bounded confidence opinion model, including a simple description of the influence of emotions on tolerances, and eventually on the evolution of opinions. Allowing for psychologically based correlation between the extreme opinions, high emotions and low tolerance for other people's views leads to quick dominance of the extreme views within the studied model, without introducing a special class of agents, as has been done in previous works. This dominance occurs even if the initial numbers of people with extreme opinions is very small. Possible suggestions related to mitigation of the process are briefly discussed.

Twin related domains in 3D microstructures of conventionally processed and grain boundary engineered materials

DOE PAGES

Lind, Jonathan; Li, Shiu Fai; Kumar, Mukul

2016-05-20

The concept of twin-limited microstructures has been explored in the literature as a crystallographically constrained grain boundary network connected via only coincident site lattice (CSL) boundaries. The advent of orientation imaging has made classification of twin-related domains (TRD) or any other orientation cluster experimentally accessible in 2D using EBSD. With the emergence of 3D orientation mapping, a comparison of TRDs in measured 3D microstructures is performed in this paper and compared against their 2D counterparts. The TRD analysis is performed on a conventionally processed (CP) and a grain boundary engineered (EM) high purity copper sample that have been subjected tomore » successive anneal procedures to promote grain growth. Finally, the EM sample shows extremely large TRDs which begin to approach that of a twin-limited microstructure, while the TRDs in the CP sample remain relatively small and remote.« less
Apennine Front revisited - Diversity of Apollo 15 highland rock types

NASA Technical Reports Server (NTRS)

Lindstrom, Marilyn M.; Marvin, Ursula B.; Vetter, Scott K.; Shervais, John W.

1988-01-01

The Apollo 15 landing site is geologically the most complex of the Apollo sites, situated at a mare-highland interface within the rings of two of the last major basin-forming impacts. Few of the Apollo 15 samples are ancient highland rocks derived from the early differentiation of the moon, or impact melts from major basin impacts. Most of the samples are regolith breccias containing abundant clasts of younger volcanic mare and KREEP basalts. The early geologic evolution of the region can be understood only by examining the small fragments of highland rocks found in regolith breccias and soils. Geochemical and petrologic studies of clasts and matrices of three impact melt breccias and four regolith breccias are presented. Twelve igneous and metamorphic rocks show extreme diversity and include a new type of ferroan norite. Twenty-five samples of highland impact melt are divided into groups based on composition. These impact melts form nearly a continuum over more than an order of magnitude in REE concentrations. This continuum may result from both major basin impacts and younger local events. Highland rocks from the Apennine Front include most of the highland rock types found at all of the other sites. An extreme diversity of highland rocks is a fundamental characteristic of the Apennine Front and is a natural result of its complex geologic evolution.
Manipulation of Samples at Extreme Temperatures for Fast in-situ Synchrotron Measurements

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

Weber, Richard

An aerodynamic sample levitation system with laser beam heating was integrated with the APS beamlines 6 ID-D, 11 ID-C and 20 BM-B. The new capability enables in-situ measurements of structure and XANES at extreme temperatures (300-3500 °C) and in conditions that completely avoid contact with container surfaces. In addition to maintaining a high degree of sample purity, the use of aerodynamic levitation enables deep supercooling and greatly enhanced glass formation from a wide variety of melts and liquids. Development and integration of controlled extreme sample environments and new measurement techniques is an important aspect of beamline operations and user support.more » Processing and solidifying liquids is a critical value-adding step in manufacturing semiconductors, optical materials, metals and in the operation of many energy conversion devices. Understanding structural evolution is of fundamental importance in condensed materials, geology, and biology. The new capability provides unique possibilities for materials research and helps to develop and maintain a competitive materials manufacturing and energy utilization industry. Test samples were used to demonstrate key features of the capability including experiments on hot crystalline materials, liquids at temperatures from about 500 to 3500 °C. The use of controlled atmospheres using redox gas mixtures enabled in-situ changes in the oxidation states of cations in melts. Significant innovations in this work were: (i) Use of redox gas mixtures to adjust the oxidation state of cations in-situ (ii) Operation with a fully enclosed system suitable for work with nuclear fuel materials (iii) Making high quality high energy in-situ x-ray diffraction measurements (iv) Making high quality in-situ XANES measurements (v) Publishing high impact results (vi) Developing independent funding for the research on nuclear materials This SBIR project work led to a commercial instrument product for the niche market of processing and studying materials in extreme conditions. MDI registered the trademark “Instruments for Innovation®” and sells products under this trademark. SBIR is the ideal vehicle for funding developments such as this since the total market size is relatively small meaning that venture investments to develop products cannot typically be obtained. The sale of niche market instruments for work in extreme conditions has been several million dollars over the last decade. The work to develop and build and sell this instrument has created stable high paying jobs in the technology manufacturing sector. Outreach enabled by this research helped with PhD thesis research, supported three undergraduate interns and one local high school student. In addition, several scientific articles were published, papers were presented at international conferences, and a workshop was held.« less
Free-stream disturbance, continuous Eigenfunctions, boundary-layer instability and transition

NASA Technical Reports Server (NTRS)

Grosch, C. E.

1980-01-01

A rational foundation is presented for the application of the linear shear flows to transition prediction, and an explicit method is given for carrying out the necessary calculations. The expansions used are shown to be complete. Sample calculations show that a typical boundary layer is very sensitive to vorticity disturbances in the inner boundary layer, near the critical layer. Vorticity disturbances three or four boundary layer thicknesses above the boundary are nearly uncoupled from the boundary layer in that the amplitudes of the discrete Tollmien-Schlicting waves are an extremely small fraction of the amplitude of the disturbance.
Using extreme phenotype sampling to identify the rare causal variants of quantitative traits in association studies.

PubMed

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J; Murcray, Cassandra Elizabeth; Conti, David

2011-12-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. © 2011 Wiley Periodicals, Inc.
Using Extreme Phenotype Sampling to Identify the Rare Causal Variants of Quantitative Traits in Association Studies

PubMed Central

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J.; Murcray, Cassandra Elizabeth; Conti, David

2014-01-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. PMID:21922541
Application of X-ray and neutron small angle scattering techniques to study the hierarchical structure of plant cell walls: a review.

PubMed

Martínez-Sanz, Marta; Gidley, Michael J; Gilbert, Elliot P

2015-07-10

Plant cell walls present an extremely complex structure of hierarchically assembled cellulose microfibrils embedded in a multi-component matrix. The biosynthesis process determines the mechanism of cellulose crystallisation and assembly, as well as the interaction of cellulose with other cell wall components. Thus, a knowledge of cellulose microfibril and bundle architecture, and the structural role of matrix components, is crucial for understanding cell wall functional and technological roles. Small angle scattering techniques, combined with complementary methods, provide an efficient approach to characterise plant cell walls, covering a broad and relevant size range while minimising experimental artefacts derived from sample treatment. Given the system complexity, approaches such as component extraction and the use of plant cell wall analogues are typically employed to enable the interpretation of experimental results. This review summarises the current research status on the characterisation of the hierarchical structure of plant cell walls using small angle scattering techniques. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
Nuclear astrophysics at FRANZ

NASA Astrophysics Data System (ADS)

Reifarth, R.; Dababneh, S.; Fiebiger, S.; Glorius, J.; Göbel, K.; Heil, M.; Hillmann, P.; Heftrich, T.; Langer, C.; Meusel, O.; Plag, R.; Schmidt, S.; Slavkovská, Z.; Veltum, D.; Weigand, M.; Wiesner, C.; Wolf, C.; Zadeh, A.

2018-01-01

The neutron capture cross section of radioactive isotopes for neutron energies in the keV region will be measured by a time-of-flight (TOF) experiment. NAUTILUS will provide a unique facility realizing the TOF technique with an ultra-short flight path at the FRANZ setup at Goethe-University Frankfurt am Main, Germany. A highly optimized spherical photon calorimeter will be built and installed at an ultra-short flight path. This new method allows the measurement of neutron capture cross sections on extremely small sample as needed in the case of 85Kr, which will be produced as an isotopically pure radioactive sample. The successful measurement will provide insights into the dynamics of the late stages of stars, an important independent check of the evolution of the Universe and the proof of principle.
The early-type strong emission-line supergiants of the Magellanic Clouds - A spectroscopic zoology

NASA Technical Reports Server (NTRS)

Shore, S. N.; Sanduleak, N.

1984-01-01

The results of a spectroscopic survey of 21 early-type extreme emission line supergiants of the Large and Small Magellanic Clouds using IUE and optical spectra are presented. The combined observations are discussed and the literature on each star in the sample is summarized. The classification procedures and the methods by which effective temperatures, bolometric magnitudes, and reddenings were assigned are discussed. The derived reddening values are given along with some results concerning anomalous reddening among the sample stars. The derived mass, luminosity, and radius for each star are presented, and the ultraviolet emission lines are described. Mass-loss rates are derived and discussed, and the implications of these observations for the evolution of the most massive stars in the Local Group are addressed.
Micromechanical ``Trampoline'' Magnetometers for Use in Pulsed Magnetic Fields Exceeding 60 Tesla

NASA Astrophysics Data System (ADS)

Balakirev, F. F.; Boebinger, G. S.; Aksyuk, V.; Gammel, P. L.; Haddon, R. C.; Bishop, D. J.

1998-03-01

We present the design, construction, and operation of a novel magnetometer for use in intense pulsed magnetic fields. The magnetometer consists of a silicon micromachined "trampoline" to which the sample is attached. The small size of the device (typically 400 microns on a side) gives a fast mechanical response (10,000 to 50,000 Hz) and extremely high sensitivity (10-11 Am^2, corresponding to 10-13 Am^2/Hz^(1/2)). The device is robust against electrical and mechanical noise and requires no special vibration isolation from the pulsed magnet. As a demonstration, we present data taken in a 60 tesla pulsed magnetic field which show clear de Haas-van Alphen oscillations in a one microgram sample of the organic superconductor K-(BEDT-TTF)_2Cu(NCS)_2.
A model for extreme plasticity

NASA Astrophysics Data System (ADS)

Thomson, S. J.; Howell, P. D.

2016-09-01

We present a mathematical model for elastoplasticity in the regime where the applied stress greatly exceeds the yield stress. This scenario is typically found in violent impact testing, where millimetre thick metal samples are subjected to pressures on the order of 10-102 GPa, while the yield stress can be as low as 10-2 GPa. In such regimes the metal can be treated as a barotropic compressible fluid in which the strength, measured by the ratio of the yield stress to the applied stress, is negligible to lowest order. Our approach is to exploit the smallness of this ratio by treating the effects of strength as a small perturbation to a leading order barotropic model. We find that for uniaxial deformations, these additional effects give rise to features in the response of the material which differ significantly from the predictions of barotropic flow.
Radiation-driven rotational motion of nanoparticles

DOE PAGES

Liang, Mengning; Harder, Ross; Robinson, Ian

2018-04-25

Focused synchrotron beams can influence a studied sample via heating, or radiation pressure effects due to intensity gradients. The high angular sensitivity of rotational X-ray tracking (RXT) of crystalline particles via their Bragg reflections can detect extremely small forces such as those caused by field gradients. By tracking the rotational motion of single crystal nanoparticles embedded in a viscous or viscoelastic medium, we observed the effects of heating in a uniform gradient beam and radiation pressure in a Gaussian profile beam. Heating of a few degrees Celsius was measured for 42μm crystals in glycerol and angular velocities of 10 -6rad/smore » due to torques of 10 - 24N∙m were measured for 340nm crystals in a colloidal gel matrix. These results show the ability to quantify small forces using rotation motion of tracer particles.« less
Radiation-driven rotational motion of nanoparticles

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

Liang, Mengning; Harder, Ross; Robinson, Ian

Focused synchrotron beams can influence a studied sample via heating, or radiation pressure effects due to intensity gradients. The high angular sensitivity of rotational X-ray tracking (RXT) of crystalline particles via their Bragg reflections can detect extremely small forces such as those caused by field gradients. By tracking the rotational motion of single crystal nanoparticles embedded in a viscous or viscoelastic medium, we observed the effects of heating in a uniform gradient beam and radiation pressure in a Gaussian profile beam. Heating of a few degrees Celsius was measured for 42μm crystals in glycerol and angular velocities of 10 -6rad/smore » due to torques of 10 - 24N∙m were measured for 340nm crystals in a colloidal gel matrix. These results show the ability to quantify small forces using rotation motion of tracer particles.« less
A Test-Length Correction to the Estimation of Extreme Proficiency Levels

ERIC Educational Resources Information Center

Magis, David; Beland, Sebastien; Raiche, Gilles

2011-01-01

In this study, the estimation of extremely large or extremely small proficiency levels, given the item parameters of a logistic item response model, is investigated. On one hand, the estimation of proficiency levels by maximum likelihood (ML), despite being asymptotically unbiased, may yield infinite estimates. On the other hand, with an…
A LDR-PCR approach for multiplex polymorphisms genotyping of severely degraded DNA with fragment sizes <100 bp.

PubMed

Zhang, Zhen; Wang, Bao-Jie; Guan, Hong-Yu; Pang, Hao; Xuan, Jin-Feng

2009-11-01

Reducing amplicon sizes has become a major strategy for analyzing degraded DNA typical of forensic samples. However, amplicon sizes in current mini-short tandem repeat-polymerase chain reaction (PCR) and mini-sequencing assays are still not suitable for analysis of severely degraded DNA. In this study, we present a multiplex typing method that couples ligase detection reaction with PCR that can be used to identify single nucleotide polymorphisms and small-scale insertion/deletions in a sample of severely fragmented DNA. This method adopts thermostable ligation for allele discrimination and subsequent PCR for signal enhancement. In this study, four polymorphic loci were used to assess the ability of this technique to discriminate alleles in an artificially degraded sample of DNA with fragment sizes <100 bp. Our results showed clear allelic discrimination of single or multiple loci, suggesting that this method might aid in the analysis of extremely degraded samples in which allelic drop out of larger fragments is observed.
Space-resolved diffusing wave spectroscopy measurements of the macroscopic deformation and the microscopic dynamics in tensile strain tests

NASA Astrophysics Data System (ADS)

Nagazi, Med-Yassine; Brambilla, Giovanni; Meunier, Gérard; Marguerès, Philippe; Périé, Jean-Noël; Cipelletti, Luca

2017-01-01

We couple a laser-based, space-resolved dynamic light scattering apparatus to a universal traction machine for mechanical extensional tests. We perform simultaneous optical and mechanical measurements on polyether ether ketone, a semi-crystalline polymer widely used in the industry. Due to the high turbidity of the sample, light is multiply scattered by the sample and the diffusing wave spectroscopy (DWS) formalism is used to interpret the data. Space-resolved DWS yields spatial maps of the sample strain and of the microscopic dynamics. An excellent agreement is found between the strain maps thus obtained and those measured by a conventional stereo-digital image correlation technique. The microscopic dynamics reveals both affine motion and plastic rearrangements. Thanks to the extreme sensitivity of DWS to displacements as small as 1 nm, plastic activity and its spatial localization can be detected at an early stage of the sample strain, making the technique presented here a valuable complement to existing material characterization methods.
Efficient bootstrap estimates for tail statistics

NASA Astrophysics Data System (ADS)

Breivik, Øyvind; Aarnes, Ole Johan

2017-03-01

Bootstrap resamples can be used to investigate the tail of empirical distributions as well as return value estimates from the extremal behaviour of the sample. Specifically, the confidence intervals on return value estimates or bounds on in-sample tail statistics can be obtained using bootstrap techniques. However, non-parametric bootstrapping from the entire sample is expensive. It is shown here that it suffices to bootstrap from a small subset consisting of the highest entries in the sequence to make estimates that are essentially identical to bootstraps from the entire sample. Similarly, bootstrap estimates of confidence intervals of threshold return estimates are found to be well approximated by using a subset consisting of the highest entries. This has practical consequences in fields such as meteorology, oceanography and hydrology where return values are calculated from very large gridded model integrations spanning decades at high temporal resolution or from large ensembles of independent and identically distributed model fields. In such cases the computational savings are substantial.
Natural Hazards characterisation in industrial practice

NASA Astrophysics Data System (ADS)

Bernardara, Pietro

2017-04-01

The definition of rare hydroclimatic extremes (up to 10-4 annual probability of occurrence) is of the utmost importance for the design of high value industrial infrastructures, such as grids, power plants, offshore platforms. The underestimation as well as the overestimation of the risk may lead to huge costs (ex. mid-life expensive works or overdesign) which may even prevent the project to happen. Nevertheless, the uncertainty associated to the extrapolation towards the rare frequencies are huge and manifold. They are mainly due to the scarcity of observations, the lack of quality on the extreme value records and on the arbitrary choice of the models used for extrapolations. This often put the design engineers in uncomfortable situations when they must choose the design values to use. Providentially, the recent progresses in the earth observation techniques, information technology, historical data collection and weather and ocean modelling are making huge datasets available. A careful use of big datasets of observations and modelled data are leading towards a better understanding of the physics of the underlying phenomena, the complex interactions between them and thus of the extreme events frequency extrapolations. This will move the engineering practice from the single site, small sample, application of statistical analysis to a more spatially coherent, physically driven extrapolation of extreme values. Few examples, from the EDF industrial practice are given to illustrate these progresses and their potential impact on the design approaches.
Statistical trend analysis and extreme distribution of significant wave height from 1958 to 1999 - an application to the Italian Seas

NASA Astrophysics Data System (ADS)

Martucci, G.; Carniel, S.; Chiggiato, J.; Sclavo, M.; Lionello, P.; Galati, M. B.

2010-06-01

The study is a statistical analysis of sea states timeseries derived using the wave model WAM forced by the ERA-40 dataset in selected areas near the Italian coasts. For the period 1 January 1958 to 31 December 1999 the analysis yields: (i) the existence of a negative trend in the annual- and winter-averaged sea state heights; (ii) the existence of a turning-point in late 80's in the annual-averaged trend of sea state heights at a site in the Northern Adriatic Sea; (iii) the overall absence of a significant trend in the annual-averaged mean durations of sea states over thresholds; (iv) the assessment of the extreme values on a time-scale of thousand years. The analysis uses two methods to obtain samples of extremes from the independent sea states: the r-largest annual maxima and the peak-over-threshold. The two methods show statistical differences in retrieving the return values and more generally in describing the significant wave field. The r-largest annual maxima method provides more reliable predictions of the extreme values especially for small return periods (<100 years). Finally, the study statistically proves the existence of decadal negative trends in the significant wave heights and by this it conveys useful information on the wave climatology of the Italian seas during the second half of the 20th century.
ELROI Extremely Low Resource Optical Identifier. A license plate for your satellite, and more.

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

Palmer, David

ELROI (Extremely Low Resource Optical Identifier) is a license plate for your satellite; a small tag that flashes an optical identification code that can be read by a small telescope on the ground. The final version of the tag will be the size of a thick postage stamp and fully autonomous: you can attach it to everything that goes into space, including small cubesats and inert debris like rocket stages, and it will keep blinking even after the satellite is shut down, reliably identifying the object from launch until re-entry.

Quantitative luminescence imaging system

DOEpatents

Erwin, D.N.; Kiel, J.L.; Batishko, C.R.; Stahl, K.A.

1990-08-14

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopic imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber. 22 figs.
Quantitative luminescence imaging system

DOEpatents

Erwin, David N.; Kiel, Johnathan L.; Batishko, Charles R.; Stahl, Kurt A.

1990-01-01

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.
Small-scale studies of roasted ore waste reveal extreme ranges of stable mercury isotope signatures

NASA Astrophysics Data System (ADS)

Smith, Robin S.; Wiederhold, Jan G.; Jew, Adam D.; Brown, Gordon E.; Bourdon, Bernard; Kretzschmar, Ruben

2014-07-01

Active and closed Hg mines are significant sources of Hg contamination to the environment, mainly due to large volumes of mine waste material disposed of on-site. The application of Hg isotopes as source tracer from such contaminated sites requires knowledge of the Hg isotope signatures of different materials potentially released to the environment. Previous work has shown that calcine, the waste residue of the on-site ore roasting process, can exhibit distinct Hg isotope signatures compared with the primary ore. Here, we report results from a detailed small-scale study of Hg isotope variations in calcine collected from the closed New Idria Hg mine, San Benito County, CA, USA. The calcine samples exhibited different internal layering features which were investigated using optical microscopy, micro X-ray fluorescence, micro X-ray absorption spectroscopy (μ-XAS), and stable Hg isotope analysis. Significant Fe, S, and Hg concentration gradients were found across the different internal layers. Isotopic analyses revealed an extreme variation with pronounced isotopic gradients across the internal layered features. Overall, δ202Hg (±0.10‰, 2 SD) describing mass-dependent fractionation (MDF) ranged from -5.96 to 14.49‰, which is by far the largest range of δ202Hg values reported for any environmental sample. In addition, Δ199Hg (±0.06‰, 2 SD) describing mass-independent fractionation (MIF) ranged from -0.17 to 0.21‰. The μ-XAS analyses suggested that cinnabar and metacinnabar are the dominant Hg-bearing phases in the calcine. Our results demonstrate that the incomplete roasting of HgS ores in Hg mines can cause extreme mass-dependent Hg isotope fractionations at the scale of individual calcine pieces with enrichments in both light and heavy Hg isotopes relative to the primary ore signatures. This finding has important implications for the application of Hg isotopes as potential source tracers for Hg released to the environment from closed Hg mines and highlights the need for detailed source signature identification.
A search for moderate-redshift survivors from the population of luminous compact passive galaxies at high redshift

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

Stockton, Alan; Shih, Hsin-Yi; Larson, Kirsten

2014-01-10

From a search of a ∼2400 deg{sup 2} region covered by both the Sloan Digital Sky Survey and UKIRT Infrared Deep Sky Survey databases, we have attempted to identify galaxies at z ∼ 0.5 that are consistent with their being essentially unmodified examples of the luminous passive compact galaxies found at z ∼ 2.5. After isolating good candidates via deeper imaging, we further refine the sample with Keck moderate-resolution spectroscopy and laser guide star adaptive-optics imaging. For four of the five galaxies that so far remain after passing through this sieve, we analyze plausible star-formation histories based on our spectramore » in order to identify galaxies that may have survived with little modification from the population formed at high redshift. We find two galaxies that are consistent with having formed ≳ 95% of their mass at z > 5. We attempt to estimate masses both from our stellar population determinations and from velocity dispersions. Given the high frequency of small axial ratios, both in our small sample and among samples found at high redshifts, we tentatively suggest that some of the more extreme examples of passive compact galaxies may have prolate morphologies.« less
Gravitational Waves From the Kerr/CFT Correspondence

NASA Astrophysics Data System (ADS)

Porfyriadis, Achilleas

Astronomical observation suggests the existence of near-extreme Kerr black holes in the sky. Properties of diffeomorphisms imply that dynamics of the near-horizon region of near-extreme Kerr are governed by an infinite-dimensional conformal symmetry. This symmetry may be exploited to analytically, rather than numerically, compute a variety of potentially observable processes. In this thesis we compute the gravitational radiation emitted by a small compact object that orbits in the near-horizon region and plunges into the horizon of a large rapidly rotating black hole. We study the holographically dual processes in the context of the Kerr/CFT correspondence and find our conformal field theory (CFT) computations in perfect agreement with the gravity results. We compute the radiation emitted by a particle on the innermost stable circular orbit (ISCO) of a rapidly spinning black hole. We confirm previous estimates of the overall scaling of the power radiated, but show that there are also small oscillations all the way to extremality. Furthermore, we reveal an intricate mode-by-mode structure in the flux to infinity, with only certain modes having the dominant scaling. The scaling of each mode is controlled by its conformal weight. Massive objects in adiabatic quasi-circular inspiral towards a near-extreme Kerr black hole quickly plunge into the horizon after passing the ISCO. The post-ISCO plunge trajectory is shown to be related by a conformal map to a circular orbit. Conformal symmetry of the near-horizon region is then used to compute analytically the gravitational radiation produced during the plunge phase. Most extreme-mass-ratio-inspirals of small compact objects into supermassive black holes end with a fast plunge from an eccentric last stable orbit. We use conformal transformations to analytically solve for the radiation emitted from various fast plunges into extreme and near-extreme Kerr black holes.
A comparison between measured surface microtopography and observed scattering in the extreme ultraviolet

NASA Technical Reports Server (NTRS)

Green, James; Jelinsky, Sharon; Bowyer, Stuart; Malina, Roger F.

1988-01-01

The paper presents comparative measurements of surface roughness on prepared samples. These measurements have been made with both Talystep profilometers and WYKO interferometers. In addition, the scattering distribution from these samples was measured at extreme ultraviolet wavelengths. The utility of the WYKO interferometer and Talystep device for specifying extreme ultraviolet mirror surface quality is discussed.
Non-spore forming eubacteria isolated at an altitude of 20,000 m in Earth's atmosphere: extended incubation periods needed for culture-based assays

USGS Publications Warehouse

Griffin, Dale W.

2008-01-01

On 13 August 2004, an atmospheric sample was collected at an altitude of 20,000 m along a west to east transect over the continental United States by NASA’s Stratospheric and Cosmic Dust Program. This sample was then shipped to the US Geological Survey’s Global Desert Dust program for microbiological analyses. This sample, which was plated on a low nutrient agar to determine if cultivable microorganisms were present, produced 590 small yellow to off-white colonies after approximately 7 weeks of incubation at room-temperature. Of 50 colonies selected for identification using 16S rRNA sequencing, 41 belonged to the family Micrococcaceae, seven to the family Microbacteriaceae, one to the genus Staphylococcus, and one to the genus Brevibacterium. All of the isolates identified were non-spore-forming pigmented bacteria, and their presence in this sample illustrate that it is not unusual to recover viable microbes at extreme altitudes. Additionally, the extended period required to initiate growth demonstrates the need for lengthy incubation periods when analyzing high-altitude samples for cultivable microorganisms.
Compilation of 1986 annual reports of the Navy ELF (Extremely Low Frequency) communications system ecological monitoring program, volume 2

NASA Astrophysics Data System (ADS)

1987-07-01

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: soil amoeba; soil and litter arthropoda and earthworm studies; biological studies on pollinating insects: megachilid bees; and small vertebrates: small mammals and nesting birds.
Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin

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

Prokhnenko, Oleksandr, E-mail: prokhnenko@helmholtz-berlin.de; Stein, Wolf-Dieter; Bleif, Hans-Jürgen

2015-03-15

The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, themore » possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.« less
Chip calorimetry for evaluation of biofilm treatment with biocides, antibiotics, and biological agents.

PubMed

Morais, Frida Mariana; Buchholz, Friederike; Maskow, Thomas

2014-01-01

Any growth or bioconversion in biofilms is accompanied by the release of heat. The heat (in J) is tightly related to the stoichiometry of the respective process via law of Hess, and the heat production rate (in W or J/s) is additionally related to the process kinetics. This heat and the heat production rate can nowadays be measured by modern calorimetry with extremely high sensitivity. Flow-through calorimetry allows the measurement of bioprocesses in biofilms in real time, without the need of invasive sample preparation and disturbing of biofilm processes. Furthermore, it can be applied for long-term measurements and is even applicable to turbid media. Chip or miniaturized calorimeters have the additional advantages of extremely short thermal equilibration times and the requirement of very small amounts of media and chemicals. The precision of flow-through chip calorimeters (about 3 mW/L) allows the detection of early stages of biofilm development (about 10(5) bacteria cm(-2)).
Confirmation of Small Dynamical and Stellar Masses for Extreme Emission Line Galaxies at z Approx. 2

NASA Technical Reports Server (NTRS)

Maseda, Michael V.; van Der Wel, Arjen; da Cunha, Elisabete; Rix, Hans-Walter; Pacifici, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; van Dokkum, Pieter; Bell, Eric F.;

2013-01-01

Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (approx. 50 km/s) for a sample of 14 extreme emission line galaxies at redshifts 1.4 < z < 2.3. These measurements imply that the total dynamical masses of these systems are low (< or approx. 3 × 10(exp 9) M). Their large [O III] (lambda)5007 equivalent widths (500-1100 Angstroms) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10(exp 8)-10(exp 9)M, confirming the presence of a violent starburst. The dynamical masses represent the first such determinations for low-mass galaxies at z > 1. The stellar mass formed in this vigorous starburst phase represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

August 2014 Hiroshima landslide disaster and its societal impact

NASA Astrophysics Data System (ADS)

Fukuoka, Hiroshi; Sassa, Kyoji; Wang, Chunxiang

2015-04-01

In the early morning of August 20, 2014, Hiroshima city was hit by a number of debris flows along a linear rain band which caused extreme downpour. This disaster claimed 74 death, although this city experienced very similar disaster in 1999, claiming more than 30 residents lives. In the most severely affected debris flow torrent, more than 50 residents were killed. Most of the casualties arose in the wooden, vulnerable houses constructed in front of the exit of torrents. Points and lessons learnt from the disaster are as follows: 1. Extreme rainfall events : geology and geomorphology does not much affect the distribution of landslides initiation sites. 2. Area of causative extreme rainfall is localized in 2 km x 10 km along the rain band. 3. Authors collected two types of sands from the source scar of the initial debris slides which induced debris flows. Tested by the ring shear apparatus under pore-pressure control condition, clear "Sliding surface liquefaction" was confirmed for both samples even under small normal stress, representing the small thickness of the slides. These results shows even instant excess pore pressure could initiate the slides and trigger slide-induced debris flow by undrained loading onto the torrent deposits. 4. Apparently long-term land-use change affected the vulnerability of the community. Residential area had expanded into hill-slope (mountainous / semi-mountainous area) especially along the torrents. Those communities were developed on the past debris flow fan. 5. As the devastated area is very close to downtown of Hiroshima city, it gave gigantic societal impact to the Japanese citizens. After 1999 Hiroshima debris flow disaster, the Landslide disaster reduction law which intends to promote designation of landslide potential risk zones, was adopted in 2000. Immediately after 2014 disaster, national diet approved revision of the bill.
Very Low Mass Stars with Extremely Low Metallicity in the Milky Way's Halo

NASA Astrophysics Data System (ADS)

Aoki, Wako; Beers, Timothy C.; Takuma, Suda; Honda, Satoshi; Lee, Young Sun

2015-08-01

Large surveys and follow-up spectroscopic studies in the past few decades have been providing chemical abundance data for a growing number of very metal-poor ([Fe/H] <-2) stars. Most of them are red giants or main-sequence turn-off stars having masses near 0.8 solar masses. Lower mass stars with extremely low metallicity ([Fe/H] <-3) have yet to be well explored. Our high-resolution spectroscopic study for very metal-poor stars found with SDSS has identified four cool main-sequence stars with [Fe/H] <-2.5 among 137 objects (Aoki et al. 2013, AJ, 145, 13). The effective temperatures of these stars are 4500--5000 K, corresponding to a mass of around 0.5 solar masses. Our standard analysis of the high-resolution spectra based on 1D-LTE model atmospheres have obtained self-consistent chemical abundances for these objects, assuming small values of micro-turbulent velocities compared with giants and turn-off stars. The low temperature of the atmospheres of these objects enables us to measure their detailed chemical abundances. Interestingly, two of the four stars have extreme chemical abundance patterns: one has the largest excesses of heavy neutron-capture elements associated with the r-process abundance pattern known to date (Aoki et al. 2010, ApJL 723, L201), and the other exhibits low abundances of the alpha-elements and odd-Z elements, suggested to be the signatures of the yields of very massive stars ( >100 solar masses; Aoki et al. 2014, Science 345, 912). Although the sample size is still small, these results indicate the potential of very low-mass stars as probes to study the early stages of the Milky Way's halo formation.
Very Low-Mass Stars with Extremely Low Metallicity in the Milky Way's Halo

NASA Astrophysics Data System (ADS)

Aoki, Wako; Beers, Timothy C.; Suda, Takuma; Honda, Satoshi; Lee, Young Sun

2016-08-01

Large surveys and follow-up spectroscopic studies in the past few decades have been providing chemical abundance data for a growing number of very metal-poor ([Fe/H] <-2) stars. Most of them are red giants or main-sequence turn-off stars having masses near 0.8 solar masses. Lower mass stars with extremely low metallicity ([Fe/H] <-3) are yet to be explored. Our high-resolution spectroscopic study for very metal-poor stars found with SDSS has identified four cool main-sequence stars with [Fe/H] <-2.5 among 137 objects (Aoki et al. 2013). The effective temperatures of these stars are 4500-5000 K, corresponding to a mass of around 0.5 solar masses. Our standard analysis of the high-resolution spectra based on 1D-LTE model atmospheres has obtained self-consistent chemical abundances for these objects, assuming small values of micro-turbulent velocities compared with giants and turn-off stars. The low temperature of the atmospheres of these objects enables us to measure their detailed chemical abundances. Interestingly, two of the four stars have extreme chemical-abundance patterns: one has the largest excesses of heavy neutron-capture elements associated with the r-process abundance pattern known to date (Aoki et al. 2010), and the other exhibits low abundances of the α-elements and odd-Z elements, suggested to be signatures of the yields of very massive stars (> 100 solar masses; Aoki et al. 2014). Although the sample size is still small, these results indicate the potential of very low-mass stars as probes to study the early stages of the Milky Way's halo formation.
Polygenic determinants in extremes of high-density lipoprotein cholesterol[S

PubMed Central

Dron, Jacqueline S.; Wang, Jian; Low-Kam, Cécile; Khetarpal, Sumeet A.; Robinson, John F.; McIntyre, Adam D.; Ban, Matthew R.; Cao, Henian; Rhainds, David; Dubé, Marie-Pierre; Rader, Daniel J.; Lettre, Guillaume; Tardif, Jean-Claude

2017-01-01

HDL cholesterol (HDL-C) remains a superior biochemical predictor of CVD risk, but its genetic basis is incompletely defined. In patients with extreme HDL-C concentrations, we concurrently evaluated the contributions of multiple large- and small-effect genetic variants. In a discovery cohort of 255 unrelated lipid clinic patients with extreme HDL-C levels, we used a targeted next-generation sequencing panel to evaluate rare variants in known HDL metabolism genes, simultaneously with common variants bundled into a polygenic trait score. Two additional cohorts were used for validation and included 1,746 individuals from the Montréal Heart Institute Biobank and 1,048 individuals from the University of Pennsylvania. Findings were consistent between cohorts: we found rare heterozygous large-effect variants in 18.7% and 10.9% of low- and high-HDL-C patients, respectively. We also found common variant accumulation, indicated by extreme polygenic trait scores, in an additional 12.8% and 19.3% of overall cases of low- and high-HDL-C extremes, respectively. Thus, the genetic basis of extreme HDL-C concentrations encountered clinically is frequently polygenic, with contributions from both rare large-effect and common small-effect variants. Multiple types of genetic variants should be considered as contributing factors in patients with extreme dyslipidemia. PMID:28870971
Polygenic determinants in extremes of high-density lipoprotein cholesterol.

PubMed

Dron, Jacqueline S; Wang, Jian; Low-Kam, Cécile; Khetarpal, Sumeet A; Robinson, John F; McIntyre, Adam D; Ban, Matthew R; Cao, Henian; Rhainds, David; Dubé, Marie-Pierre; Rader, Daniel J; Lettre, Guillaume; Tardif, Jean-Claude; Hegele, Robert A

2017-11-01

HDL cholesterol (HDL-C) remains a superior biochemical predictor of CVD risk, but its genetic basis is incompletely defined. In patients with extreme HDL-C concentrations, we concurrently evaluated the contributions of multiple large- and small-effect genetic variants. In a discovery cohort of 255 unrelated lipid clinic patients with extreme HDL-C levels, we used a targeted next-generation sequencing panel to evaluate rare variants in known HDL metabolism genes, simultaneously with common variants bundled into a polygenic trait score. Two additional cohorts were used for validation and included 1,746 individuals from the Montréal Heart Institute Biobank and 1,048 individuals from the University of Pennsylvania. Findings were consistent between cohorts: we found rare heterozygous large-effect variants in 18.7% and 10.9% of low- and high-HDL-C patients, respectively. We also found common variant accumulation, indicated by extreme polygenic trait scores, in an additional 12.8% and 19.3% of overall cases of low- and high-HDL-C extremes, respectively. Thus, the genetic basis of extreme HDL-C concentrations encountered clinically is frequently polygenic, with contributions from both rare large-effect and common small-effect variants. Multiple types of genetic variants should be considered as contributing factors in patients with extreme dyslipidemia. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.
Contrasting environmental memories by ancient soils on different parent rocks in the South-western Italian Alps

NASA Astrophysics Data System (ADS)

D'Amico, Michele; Catoni, Marcella; Bonifacio, Eleonora; Zanini, Ermanno

2014-05-01

Ancient soils (pre-Holocenic paleosols and vetusols) are uncommon on the Alps, because of the extensive Pleistocenic glaciations which erased most of the previously existing soils, the slope steepness and climatic conditions favoring soil erosion. However, in few sites, particularly in the outermost sections of the Alpine range, Pleistocene glaciers covered only small and scattered surfaces because of the low altitude reached in the basins, and ancient soils could be preserved for long periods of time on particularly stable surfaces. We described and sampled soils on 11 stable surfaces in the Upper Tanaro valley, Ligurian Alps (Southwestern Piemonte, Italy). The sampling sites were characterized by low steepness and elevation between 600 to 1600 m, under present day lower montane Castanea sativa/Ostrya carpinifolia forests, montane Fagus sylvatica and Pinus uncinata forests or montane heath/grazed grassland, on different substrata. In particular, we sampled soils developed on dolomite, limestone, quartzite, gneiss and shales. The soils were always well representative of the pedogenic trends active on the respective parent materials, i.e. the skeletal fraction in each soil was always composed of just one rock type, despite the proximity of lithological boundaries and the small dimensions of the different outcrops, often coexisting on the same stable surface. All the considered profiles showed signs of extremely long pedogenesis and/or different phases of intense pedogenesis interrupted by the deposition of periglacial cover beds in the steepest sites. Up to four phases of intense pedogenesis were recognized where cover beds were developed, presumably during cold Pleistocene phases, as present-day climate is not cold enough to create such periglacial morphologies. In such cases, each cover bed underwent similar pedogenesis, strongly dependent on the parent material: on quartzite, podzols with thick E horizons and well developed placic ones were formed in all phases except the most superficial one (i.e., Holocene phase), where non cemented spodic horizons or weakly cemented ortstein were formed; placic horizons were never found in Holocene soils. On limestone, each cover bed separated soils with extremely hard petrocalcic horizons overlaid by argillic ones. Where no cover beds were observed, podzols with extremely thick E horizons (up to more than 2 m thick) and a very hard, very thick ortstein were formed on quartzite. Red Nitisols-like or reddish brown Luvisols were formed on limestone and dolomite, while red, extremely acidic Alisols, with or without fragipan horizons were formed on shales. Very large stone circles and other large patterned ground features, which can be interpreted as evidence of past permafrost conditions, were preserved on coarse quartzitic conglomerate. These soils represent excellent pedo-signatures of different specific past climatic or environmental conditions, as a response of different lithologies to specific soil-forming environments, which range from warm and humid climates typical of red Luvisols and Nitisols, to cool and wet climates leading to the formation of Podzols with placic or ortstein horizons, to extremely cold and dry ones characterizing permafrost sites and often associated with fragipan formation, to warm and dry leading to the cementation of petrocalcic horizons. The precise dating and interpretation of these soils are intriguing.
Modelling hydrological extremes under non-stationary conditions using climate covariates

NASA Astrophysics Data System (ADS)

Vasiliades, Lampros; Galiatsatou, Panagiota; Loukas, Athanasios

2013-04-01

Extreme value theory is a probabilistic theory that can interpret the future probabilities of occurrence of extreme events (e.g. extreme precipitation and streamflow) using past observed records. Traditionally, extreme value theory requires the assumption of temporal stationarity. This assumption implies that the historical patterns of recurrence of extreme events are static over time. However, the hydroclimatic system is nonstationary on time scales that are relevant to extreme value analysis, due to human-mediated and natural environmental change. In this study the generalized extreme value (GEV) distribution is used to assess nonstationarity in annual maximum daily rainfall and streamflow timeseries at selected meteorological and hydrometric stations in Greece and Cyprus. The GEV distribution parameters (location, scale, and shape) are specified as functions of time-varying covariates and estimated using the conditional density network (CDN) as proposed by Cannon (2010). The CDN is a probabilistic extension of the multilayer perceptron neural network. Model parameters are estimated via the generalized maximum likelihood (GML) approach using the quasi-Newton BFGS optimization algorithm, and the appropriate GEV-CDN model architecture for the selected meteorological and hydrometric stations is selected by fitting increasingly complicated models and choosing the one that minimizes the Akaike information criterion with small sample size correction. For all case studies in Greece and Cyprus different formulations are tested with combinational cases of stationary and nonstationary parameters of the GEV distribution, linear and non-linear architecture of the CDN and combinations of the input climatic covariates. Climatic indices such as the Southern Oscillation Index (SOI), which describes atmospheric circulation in the eastern tropical pacific related to El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) index that varies on an interdecadal rather than interannual time scale and the atmospheric circulation patterns as expressed by the North Atlantic Oscillation (NAO) index are used to express the GEV parameters as functions of the covariates. Results show that the nonstationary GEV model can be an efficient tool to take into account the dependencies between extreme value random variables and the temporal evolution of the climate.
Compositional patterns in the genomes of unicellular eukaryotes.

PubMed

Costantini, Maria; Alvarez-Valin, Fernando; Costantini, Susan; Cammarano, Rosalia; Bernardi, Giorgio

2013-11-05

The genomes of multicellular eukaryotes are compartmentalized in mosaics of isochores, large and fairly homogeneous stretches of DNA that belong to a small number of families characterized by different average GC levels, by different gene concentration (that increase with GC), different chromatin structures, different replication timing in the cell cycle, and other different properties. A question raised by these basic results concerns how far back in evolution the compartmentalized organization of the eukaryotic genomes arose. In the present work we approached this problem by studying the compositional organization of the genomes from the unicellular eukaryotes for which full sequences are available, the sample used being representative. The average GC levels of the genomes from unicellular eukaryotes cover an extremely wide range (19%-60% GC) and the compositional patterns of individual genomes are extremely different but all genomes tested show a compositional compartmentalization. The average GC range of the genomes of unicellular eukaryotes is very broad (as broad as that of prokaryotes) and individual compositional patterns cover a very broad range from very narrow to very complex. Both features are not surprising for organisms that are very far from each other both in terms of phylogenetic distances and of environmental life conditions. Most importantly, all genomes tested, a representative sample of all supergroups of unicellular eukaryotes, are compositionally compartmentalized, a major difference with prokaryotes.
Social anhedonia, but not positive schizotypy, is associated with poor affective control.

PubMed

Martin, Elizabeth A; Cicero, David C; Kerns, John G

2012-07-01

Emotion researchers have distinguished between automatic versus controlled processing of affective information. One previous study with a small sample size found that extreme levels of social anhedonia (SocAnh) in college students, which predicts future schizophrenia-spectrum disorders, is associated with problems in controlled affective processing on a primed evaluation task. The current study examined whether in a larger college student sample SocAnh but not elevated perceptual aberration/magical ideation (PerMag) was associated with poor controlled affective processing. On the primed evaluation task, primes and targets could be either affectively congruent or incongruent and participants judged the valence of targets. Previous research on this task has found that participants appear to use controlled processing in an attempt to counteract the influence of the prime in evaluating the target. In this study, compared to the PerMag (n = 48) and control groups (n = 338), people with extreme levels of social anhedonia (n = 62) exhibited increased affective interference as they were slower for incongruent than for congruent trials. In contrast, there were no differences between the PerMag and control groups. Overall, these results suggest that SocAnh, but not PerMag, is associated with poor controlled affective processing. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Selective DNA Pooling for Determination of Linkage between a Molecular Marker and a Quantitative Trait Locus

PubMed Central

Darvasi, A.; Soller, M.

1994-01-01

Selective genotyping is a method to reduce costs in marker-quantitative trait locus (QTL) linkage determination by genotyping only those individuals with extreme, and hence most informative, quantitative trait values. The DNA pooling strategy (termed: ``selective DNA pooling'') takes this one step further by pooling DNA from the selected individuals at each of the two phenotypic extremes, and basing the test for linkage on marker allele frequencies as estimated from the pooled samples only. This can reduce genotyping costs of marker-QTL linkage determination by up to two orders of magnitude. Theoretical analysis of selective DNA pooling shows that for experiments involving backcross, F(2) and half-sib designs, the power of selective DNA pooling for detecting genes with large effect, can be the same as that obtained by individual selective genotyping. Power for detecting genes with small effect, however, was found to decrease strongly with increase in the technical error of estimating allele frequencies in the pooled samples. The effect of technical error, however, can be markedly reduced by replication of technical procedures. It is also shown that a proportion selected of 0.1 at each tail will be appropriate for a wide range of experimental conditions. PMID:7896115
Extremes in ecology: Avoiding the misleading effects of sampling variation in summary analyses

USGS Publications Warehouse

Link, W.A.; Sauer, J.R.

1996-01-01

Surveys such as the North American Breeding Bird Survey (BBS) produce large collections of parameter estimates. One's natural inclination when confronted with lists of parameter estimates is to look for the extreme values: in the BBS, these correspond to the species that appear to have the greatest changes in population size through time. Unfortunately, extreme estimates are liable to correspond to the most poorly estimated parameters. Consequently, the most extreme parameters may not match up with the most extreme parameter estimates. The ranking of parameter values on the basis of their estimates are a difficult statistical problem. We use data from the BBS and simulations to illustrate the potential misleading effects of sampling variation in rankings of parameters. We describe empirical Bayes and constrained empirical Bayes procedures which provide partial solutions to the problem of ranking in the presence of sampling variation.
Expression of K19 and K7 in dysplastic nodules and hepatocellular carcinoma.

PubMed

Bae, Jun Sang; Choi, Ha Na; Noh, Sang Jae; Park, Byung Hyun; Jang, Kyu Yun; Park, Cheol Keun; Moon, Woo Sung

2012-08-01

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors characterized by a multistep process of tumor development. Nodular lesions that differ from the surrounding liver parenchyma and are characterized by cytological or structural atypia are termed dysplastic nodules (DNs). DNs are well-known precancerous HCC lesions. Expression of keratin (K) 19 and K7, molecular markers of hepatic progenitor cells and cholangiocytes, has been reported in certain HCCs. However, it remains unclear whether K19-positive HCC cells are derived from true hepatic progenitor cells or mature cells that have undergone a dedifferentiation or a transdifferentiation process. In total, 107 tissue sections (13 low-grade DNs, 15 high-grade DNs, 27 small HCCs and 52 large HCCs) from resected liver samples and 132 HCC tissue microarray (TMA) cores were subjected to immunohistochemical analysis for K19 and K7. Clinicopathological data of the HCC patients were evaluated. K19 expression was found in 0% of DNs, 19% of small HCCs (≤2 cm), 8% of large HCCs (>2 cm) and 8% of TMA samples. K7 expression was found in 14% of DNs, 41% of small HCCs, 15% of large HCCs and 6% of TMA samples. Among the five K19-positive small HCCs, four were distinctly nodular and one tumor was an infiltrative type. No vaguely nodular HCC was positive for K19. K19 expression was significantly associated with histological grade (P=0.023), serum α-fetoprotein level (P=0.001) and K7 expression (P=0.001) in HCC. K19 expression was an independent prognostic factor for overall survival in non-viral HCC patients (P=0.003). K19 expression is extremely rare in DNs and occurs in progressed small HCCs. Our results suggest that K19 expression may be an acquired feature of carcinoma cells during HCC progression in certain HCCs.
Digital image processing of nanometer-size metal particles on amorphous substrates

NASA Technical Reports Server (NTRS)

Soria, F.; Artal, P.; Bescos, J.; Heinemann, K.

1989-01-01

The task of differentiating very small metal aggregates supported on amorphous films from the phase contrast image features inherently stemming from the support is extremely difficult in the nanometer particle size range. Digital image processing was employed to overcome some of the ambiguities in evaluating such micrographs. It was demonstrated that such processing allowed positive particle detection and a limited degree of statistical size analysis even for micrographs where by bare eye examination the distribution between particles and erroneous substrate features would seem highly ambiguous. The smallest size class detected for Pd/C samples peaks at 0.8 nm. This size class was found in various samples prepared under different evaporation conditions and it is concluded that these particles consist of 'a magic number' of 13 atoms and have cubooctahedral or icosahedral crystal structure.
Automated Lab-on-a-Chip Electrophoresis System

NASA Technical Reports Server (NTRS)

Willis, Peter A.; Mora, Maria; Greer, Harold F.; Fisher, Anita M.; Bryant, Sherrisse

2012-01-01

Capillary electrophoresis is an analytical technique that can be used to detect and quantify extremely small amounts of various biological molecules. In the search for biochemical traces of life on other planets, part of this search involves an examination of amino acids, which are the building blocks of life on Earth. The most sensitive method for detecting amino acids is the use of laser induced fluorescence. However, since amino acids do not, in general, fluoresce, they first must be reacted with a fluorescent dye label prior to analysis. After this process is completed, the liquid sample then must be transported into the electrophoresis system. If the system is to be reused multiple times, samples must be added and removed each time. In typical laboratories, this process is performed manually by skilled human operators using standard laboratory equipment. This level of human intervention is not possible if this technology is to be implemented on extraterrestrial targets. Microchip capillary electrophoresis (CE) combined with laser induced fluorescence detection (LIF) was selected as an extremely sensitive method to detect amino acids and other compounds that can be tagged with a fluorescent dye. It is highly desirable to package this technology into an integrated, autonomous, in situ instrument capable of performing CE-LIF on the surface of an extraterrestrial body. However, to be fully autonomous, the CE device must be able to perform a large number of sample preparation and analysis operations without the direct intervention of a human.
Recent trends in aviation turbine fuel properties

NASA Technical Reports Server (NTRS)

Friedman, R.

1982-01-01

Plots and tables, compiled from Department of Energy (and predecessor agency) inspection reports from 1969 to 1980, present ranges, averages, extremes, and trends for most of the 22 properties of Jet A aviation turbine fuel. In recent years, average values of aromatics content, mercaptan sulfur content, distillation temperature of 10 percent recovered, smoke point, and freezing point show small but recognizable trends toward their specification limits. About 80 percent of the fuel samples had at least one property near specification, defined as within a standard band about the specification limit. By far the most common near-specification properties were aromatics content, smoke point, and freezing point.
Low Gravity Freefall Facilities

NASA Technical Reports Server (NTRS)

1981-01-01

Composite of Marshall Space Flight Center's Low-Gravity Free Fall Facilities.These facilities include a 100-meter drop tower and a 100-meter drop tube. The drop tower simulates in-flight microgravity conditions for up to 4.2 seconds for containerless processing experiments, immiscible fluids and materials research, pre-flight hardware design test and flight experiment simulation. The drop tube simulates in-flight microgravity conditions for up to 4.6 seconds and is used extensively for ground-based microgravity convection research in which extremely small samples are studied. The facility can provide deep undercooling for containerless processing experiments that require materials to remain in a liquid phase when cooled below the normal solidification temperature.
Microgravity

NASA Image and Video Library

1981-03-30

Composite of Marshall Space Flight Center's Low-Gravity Free Fall Facilities.These facilities include a 100-meter drop tower and a 100-meter drop tube. The drop tower simulates in-flight microgravity conditions for up to 4.2 seconds for containerless processing experiments, immiscible fluids and materials research, pre-flight hardware design test and flight experiment simulation. The drop tube simulates in-flight microgravity conditions for up to 4.6 seconds and is used extensively for ground-based microgravity convection research in which extremely small samples are studied. The facility can provide deep undercooling for containerless processing experiments that require materials to remain in a liquid phase when cooled below the normal solidification temperature.
Compilation of 1986 annual reports of the Navy ELF (extremely low frequency) communications system ecological-monitoring program. Volume 2. Tabs D-G. Annual progress report, January-December 1986

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

Not Available

1987-07-01

The U.S. Navy is conducting a long-term program to monitor for possible effects from the operation of its Extremely Low Frequency (ELF) Communications System to resident biota and their ecological relationships. This report documents progress of the following studies: Soil Amoeba; Soil and Litter Arthropoda and Earthworm Studies; Biological Studies on Pollinating insects: Megachilid Bees; and Small Vertebrates: Small Mammals and Nesting Birds.
Mechanism of shallow disrupted slide induced by extreme rainfall

NASA Astrophysics Data System (ADS)

Igwe, O.; Fukuoka, H.

2010-12-01

On July 16, 2010, extreme rainfall attacked western Japan and it caused very intense rainfall in Shobara city, Hiroshima prefecture, Japan. This rainfall induced hundreds of shallow disrupted slides and many of those became debris flows. One of this debris flows attacked a house standing in front of the exit of a channel, and claimed a resident’s life. Western Japan had repeatedly similar disasters in the past. Last event took place from July 19 to 26, 2009, when western Japan had a severe rainstorms and caused floods and landslides. Most of the landslides are debris slide - debris flows. Most devastated case took place in Hofu city, Japan. On July 21, extremely intense rainstorm caused numerous debris flows and mud flows in the hillslopes. Some of the debris flows destroyed residential houses and home for elderly people, and finally killed 14 residents. One of the unusual feature of both disaster was that landslides are distributed in very narrow area. In the 2010 Shobara city disaster, all of the landslides were distributed in 5 km x 3 km, and in the 2009 Hofu city disaster, most devastated zone of landslides were 10 km x 5 km. Rain radars of Meteorological Agency of Government of Japan detected the intense rainfall, however, the spatial resolution is usually larger than 5 km and the disaster area is too small to predict landslides nor issue warning. Furthermore, it was found that the growth rate of baby clouds was very quick. The geology of both areas are rhyolite (Shobara) and granite (Hofu), so the areal assessment of landslide hazard should be prepared before those intense rainfall will come. As for the Hofu city case, it was proved that debris flows took place in the high precipitation area and covered by covered by weathered granite sands and silts which is called “masa". This sands has been proved susceptible against landslides under extreme rainfall conditions. However, the transition from slide - debris flow process is not well revealed, except authors past experiment on the similar masa samples in June 1999 Hiroshima debris flow case. Authors have embedded pore pressure control system for the undrained ring shear apparatus. Strongly weathered sandy soils were sampled just on the smooth and flat granitic sliding surface of one of the upstream small-scale landslides. Those contained finer grains and lower permeability rather than the one sampled in the Hiroshima case. Sample was consolidated by smaller stress corresponding to the site condition, and saturated by overnight circulating de-aired water. Normal stress and shear stress corresponding the slope condition was given, then, pore pressure (back pressure) was raised artificially at constant rate. When the effective stress reached the failure line, suddenly measured pore pressure monitored at about 2 mm above the shear plane, quickly increased. This sudden change abruptly accelerate the shear displacement. Stress condition soon reached the steady state and remained there thereafter. The reason of the excess pore pressure generation was the negative dilatancy, following a slight positive dilatancy. Most of the negative dilatancy could be explained by collapse of loose soil skelton as well as grain crushing during deformation and shearing.
A new approach for the description of discharge extremes in small catchments

NASA Astrophysics Data System (ADS)

Pavia Santolamazza, Daniela; Lebrenz, Henning; Bárdossy, András

2017-04-01

Small catchment basins in Northwestern Switzerland, characterized by small concentration times, are frequently targeted by floods. The peak and the volume of these floods are commonly estimated by a frequency analysis of occurrence and described by a random variable, assuming a uniform distributed probability and stationary input drivers (e.g. precipitation, temperature). For these small catchments, we attempt to describe and identify the underlying mechanisms and dynamics at the occurrence of extremes by means of available high temporal resolution (10 min) observations and to explore the possibilities to regionalize hydrological parameters for short intervals. Therefore, we investigate new concepts for the flood description such as entropy as a measure of disorder and dispersion of precipitation. First findings and conclusions of this ongoing research are presented.
Cool North European summers and possible links to explosive volcanic eruptions

NASA Astrophysics Data System (ADS)

Jones, P. D.; Melvin, T. M.; Harpham, C.; Grudd, H.; Helama, S.

2013-06-01

Exactly dated tree-ring measurements such as ring width (TRW) and maximum latewood density (MXD), which are sensitive to summer temperatures, can provide possible routes to investigate the occurrence of hemispheric-wide cool summers that might be linked to explosive tropical volcanic eruptions. These measurements can provide much longer records than the instrumental period, enabling much longer periods to be assessed and offers the potential to look at much larger eruptions than recorded over the last 200 years. This paper looks at TRW evidence from Northern Fennoscandia extending over the last 7500 years, using two independently produced chronologies from northern Sweden and northern Finland. TRW is less responsive than MXD to cool summer temperatures, but MXD is only available for the last 2000 years. Additionally, looking at a relatively small location, compared to the Northern Hemisphere average, adds considerable noise. Progress in this area is likely to be made by developing more millennial-long TRW series across northern high latitudes or being able to develop MXD series from the sub-fossil material, which comprises most of the samples prior to the last 1000 years. The three most extreme negative values for the region for the last 2000 years are 1601, 542, and 1837, although the latter is not extreme in a long instrumental record for the region. The most extreme year of all occurred in 330BC. Of the 20 most extreme negative years, nine occurred during the AD years with the remaining 11 occurring during the prior 5500 years.
Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum

NASA Technical Reports Server (NTRS)

Deutsch, Georg; Grillenbeck, Anton

2008-01-01

Some scientific missions require to an extreme extent the absence of any on-board microvibration. Recent projects dedicated to measuring the Earth's gravity field and modeling the geoid with extremely high accuracy are examples. Their missions demand for extremely low micro-vibration environment on orbit for: (1) Not disturbing the measurement of earth gravity effects with the installed gradiometer or (2) Even not damaging the very high sensitive instruments. Based on evidence from ongoing missions multi-layer insulation (MLI) type thermal control blankets have been identified as a structural element of spacecrafts which might deform under temperature variations being caused by varying solar irradiation in orbit. Any such deformation exerts tiny forces which may cause small reactions resulting in micro-vibrations, in particular by exciting the spacecraft eigenmodes. The principle of the test set-up for the micro-vibration test was as follows. A real side wall panel of the spacecraft (size about 0.25 m2) was low-frequency suspended in a thermal vacuum chamber. On the one side of this panel, the MLI samples were fixed by using the standard methods. In front of the MLI, an IR-rig was installed which provided actively controlled IR-radiation power of about 6 kW/m2 in order to heat the MLI surface. The cooling was passive using the shroud temperature at a chamber pressure <1E-5mbar. The resulting micro-vibrations due to MLI motion in the heating and the cooling phase were measured via seismic accelerometers which were rigidly mounted to the panel. Video recording was used to correlate micro-vibration events to any visual MLI motion. Different MLI sample types were subjected to various thermal cycles in a temperature range between -60 C to +80 C. In this paper, the experience on these micro-vibration measurements will be presented and the conclusions for future applications will be discussed
Rank score and permutation testing alternatives for regression quantile estimates

USGS Publications Warehouse

Cade, B.S.; Richards, J.D.; Mielke, P.W.

2006-01-01

Performance of quantile rank score tests used for hypothesis testing and constructing confidence intervals for linear quantile regression estimates (0 ≤ τ ≤ 1) were evaluated by simulation for models with p = 2 and 6 predictors, moderate collinearity among predictors, homogeneous and hetero-geneous errors, small to moderate samples (n = 20–300), and central to upper quantiles (0.50–0.99). Test statistics evaluated were the conventional quantile rank score T statistic distributed as χ2 random variable with q degrees of freedom (where q parameters are constrained by H 0:) and an F statistic with its sampling distribution approximated by permutation. The permutation F-test maintained better Type I errors than the T-test for homogeneous error models with smaller n and more extreme quantiles τ. An F distributional approximation of the F statistic provided some improvements in Type I errors over the T-test for models with > 2 parameters, smaller n, and more extreme quantiles but not as much improvement as the permutation approximation. Both rank score tests required weighting to maintain correct Type I errors when heterogeneity under the alternative model increased to 5 standard deviations across the domain of X. A double permutation procedure was developed to provide valid Type I errors for the permutation F-test when null models were forced through the origin. Power was similar for conditions where both T- and F-tests maintained correct Type I errors but the F-test provided some power at smaller n and extreme quantiles when the T-test had no power because of excessively conservative Type I errors. When the double permutation scheme was required for the permutation F-test to maintain valid Type I errors, power was less than for the T-test with decreasing sample size and increasing quantiles. Confidence intervals on parameters and tolerance intervals for future predictions were constructed based on test inversion for an example application relating trout densities to stream channel width:depth.
Correlation between pubic hair grooming and STIs: results from a nationally representative probability sample.

PubMed

Osterberg, E Charles; Gaither, Thomas W; Awad, Mohannad A; Truesdale, Matthew D; Allen, Isabel; Sutcliffe, Siobhan; Breyer, Benjamin N

2017-05-01

STIs are the most common infections among adults. Concurrently, pubic hair grooming is prevalent. Small-scale studies have demonstrated a relationship between pubic hair grooming and STIs. We aim to examine this relationship in a large sample of men and women. We conducted a probability survey of US residents aged 18-65 years. The survey ascertained self-reported pubic hair grooming practices, sexual behaviours and STI history. We defined extreme grooming as removal of all pubic hair more than 11 times per year and high-frequency grooming as daily/weekly trimming. Cutaneous STIs included herpes, human papillomavirus, syphilis and molluscum. Secretory STIs included gonorrhoea, chlamydia and HIV. We analysed lice separately. Of 7580 respondents who completed the survey, 74% reported grooming their pubic hair, 66% of men and 84% of women. After adjusting for age and lifetime sexual partners, ever having groomed was positively associated with a history of self-reported STIs (OR 1.8; 95% CI 1.4 to 2.2), including cutaneous STIs (OR 2.6; CI 1.8 to 3.7), secretory STIs (OR 1.7; CI 1.3 to 2.2) and lice (OR 1.9; CI 1.3 to 2.9). These positive associations were stronger for extreme groomers (OR 4.4; CI 2.9 to 6.8) and high-frequency groomers (OR 3.5; CI 2.3 to 5.4) with cutaneous STIs, and for non-extreme groomers (OR 2.0; CI 1.3 to 3.0) and low-frequency groomers (OR 2.0; CI 1.3 to 3.1) with lice. Among a representative sample of US residents, pubic hair grooming was positively related to self-reported STI history. Further research is warranted to gain insight into STI risk-reduction strategies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
33 CFR 80.105 - Calais, ME to Cape Small, ME.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Calais, ME to Cape Small, ME. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.105 Calais, ME to Cape Small, ME... International Bridge at Calais, ME to the southwesternmost extremity of Bald Head at Cape Small. ...
33 CFR 80.105 - Calais, ME to Cape Small, ME.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Calais, ME to Cape Small, ME. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.105 Calais, ME to Cape Small, ME... International Bridge at Calais, ME to the southwesternmost extremity of Bald Head at Cape Small. ...
33 CFR 80.105 - Calais, ME to Cape Small, ME.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Calais, ME to Cape Small, ME. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.105 Calais, ME to Cape Small, ME... International Bridge at Calais, ME to the southwesternmost extremity of Bald Head at Cape Small. ...
33 CFR 80.105 - Calais, ME to Cape Small, ME.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Calais, ME to Cape Small, ME. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.105 Calais, ME to Cape Small, ME... International Bridge at Calais, ME to the southwesternmost extremity of Bald Head at Cape Small. ...
Quick Tips Guide for Small Manufacturing Businesses

EPA Pesticide Factsheets

Small manufacturing businesses can use this Quick Tips Guide to be better prepared for future extreme weather events. This guide discusses keeping good records, improving housekeeping procedures, and training employees.

Integrated hollow microneedle-optofluidic biosensor for therapeutic drug monitoring in sub-nanoliter volumes

NASA Astrophysics Data System (ADS)

Ranamukhaarachchi, Sahan A.; Padeste, Celestino; Dübner, Matthias; Häfeli, Urs O.; Stoeber, Boris; Cadarso, Victor J.

2016-07-01

Therapeutic drug monitoring (TDM) typically requires painful blood drawn from patients. We propose a painless and minimally-invasive alternative for TDM using hollow microneedles suitable to extract extremely small volumes (<1 nL) of interstitial fluid to measure drug concentrations. The inner lumen of a microneedle is functionalized to be used as a micro-reactor during sample collection to trap and bind target drug candidates during extraction, without requirements of sample transfer. An optofluidic device is integrated with this microneedle to rapidly quantify drug analytes with high sensitivity using a straightforward absorbance scheme. Vancomycin is currently detected by using volumes ranging between 50-100 μL with a limit of detection (LoD) of 1.35 μM. The proposed microneedle-optofluidic biosensor can detect vancomycin with a sample volume of 0.6 nL and a LoD of <100 nM, validating this painless point of care system with significant potential to reduce healthcare costs and patients suffering.
Two Different Views on the World Around Us: The World of Uniformity versus Diversity.

PubMed

Kwon, JaeHwan; Nayakankuppam, Dhananjay

2016-01-01

We propose that when individuals believe in fixed traits of personality (entity theorists), they are likely to expect a world of "uniformity." As such, they easily infer a population statistic from a small sample of data with confidence. In contrast, individuals who believe in malleable traits of personality (incremental theorists) are likely to presume a world of "diversity," such that they "hesitate" to infer a population statistic from a similarly sized sample. In four laboratory experiments, we found that compared to incremental theorists, entity theorists estimated a population mean from a sample with a greater level of confidence (Studies 1a and 1b), expected more homogeneity among the entities within a population (Study 2), and perceived an extreme value to be more indicative of an outlier (Study 3). These results suggest that individuals are likely to use their implicit self-theory orientations (entity theory versus incremental theory) to see a population in general as a constitution either of homogeneous or heterogeneous entities.
Integrated hollow microneedle-optofluidic biosensor for therapeutic drug monitoring in sub-nanoliter volumes

PubMed Central

Ranamukhaarachchi, Sahan A.; Padeste, Celestino; Dübner, Matthias; Häfeli, Urs O.; Stoeber, Boris; Cadarso, Victor J.

2016-01-01

Therapeutic drug monitoring (TDM) typically requires painful blood drawn from patients. We propose a painless and minimally-invasive alternative for TDM using hollow microneedles suitable to extract extremely small volumes (<1 nL) of interstitial fluid to measure drug concentrations. The inner lumen of a microneedle is functionalized to be used as a micro-reactor during sample collection to trap and bind target drug candidates during extraction, without requirements of sample transfer. An optofluidic device is integrated with this microneedle to rapidly quantify drug analytes with high sensitivity using a straightforward absorbance scheme. Vancomycin is currently detected by using volumes ranging between 50–100 μL with a limit of detection (LoD) of 1.35 μM. The proposed microneedle-optofluidic biosensor can detect vancomycin with a sample volume of 0.6 nL and a LoD of <100 nM, validating this painless point of care system with significant potential to reduce healthcare costs and patients suffering. PMID:27380889
Sampling Mars: Analytical requirements and work to do in advance

NASA Technical Reports Server (NTRS)

Koeberl, Christian

1988-01-01

Sending a mission to Mars to collect samples and return them to the Earth for analysis is without doubt one of the most exciting and important tasks for planetary science in the near future. Many scientifically important questions are associated with the knowledge of the composition and structure of Martian samples. Amongst the most exciting questions is the clarification of the SNC problem- to prove or disprove a possible Martian origin of these meteorites. Since SNC meteorites have been used to infer the chemistry of the planet Mars, and its evolution (including the accretion history), it would be important to know if the whole story is true. But before addressing possible scientific results, we have to deal with the analytical requirements, and with possible pre-return work. It is unlikely to expect that a possible Mars sample return mission will bring back anything close to the amount returned by the Apollo missions. It will be more like the amount returned by the Luna missions, or at least in that order of magnitude. This requires very careful sample selection, and very precise analytical techniques. These techniques should be able to use minimal sample sizes and on the other hand optimize the scientific output. The possibility to work with extremely small samples should not obstruct another problem: possible sampling errors. As we know from terrestrial geochemical studies, sampling procedures are quite complicated and elaborate to ensure avoiding sampling errors. The significance of analyzing a milligram or submilligram sized sample and putting that in relationship with the genesis of whole planetary crusts has to be viewed with care. This leaves a dilemma on one hand, to minimize the sample size as far as possible in order to have the possibility of returning as many different samples as possible, and on the other hand to take a sample large enough to be representative. Whole rock samples are very useful, but should not exceed the 20 to 50 g range, except in cases of extreme inhomogeneity, because for larger samples the information tends to become redundant. Soil samples should be in the 2 to 10 g range, permitting the splitting of the returned samples for studies in different laboratories with variety of techniques.
Accurate high-speed liquid handling of very small biological samples.

PubMed

Schober, A; Günther, R; Schwienhorst, A; Döring, M; Lindemann, B F

1993-08-01

Molecular biology techniques require the accurate pipetting of buffers and solutions with volumes in the microliter range. Traditionally, hand-held pipetting devices are used to fulfill these requirements, but many laboratories have also introduced robotic workstations for the handling of liquids. Piston-operated pumps are commonly used in manually as well as automatically operated pipettors. These devices cannot meet the demands for extremely accurate pipetting of very small volumes at the high speed that would be necessary for certain applications (e.g., in sequencing projects with high throughput). In this paper we describe a technique for the accurate microdispensation of biochemically relevant solutions and suspensions with the aid of a piezoelectric transducer. It is suitable for liquids of a viscosity between 0.5 and 500 milliPascals. The obtainable drop sizes range from 5 picoliters to a few nanoliters with up to 10,000 drops per second. Liquids can be dispensed in single or accumulated drops to handle a wide volume range. The system proved to be excellently suitable for the handling of biological samples. It did not show any detectable negative impact on the biological function of dissolved or suspended molecules or particles.
Electrical characterization of FBK small-pitch 3D sensors after γ-ray, neutron and proton irradiations

NASA Astrophysics Data System (ADS)

Dalla Betta, G.-F.; Boscardin, M.; Hoeferkamp, M.; Mendicino, R.; Seidel, S.; Sultan, D. M. S.

2017-11-01

In view of applications in the tracking detectors at the High Luminosity LHC (HL-LHC), we have developed a new generation of 3D pixel sensors featuring small-pitch (50 × 50 or 25 × 100 μ m2) and thin active layer (~ 100 μ m). Owing to the very short inter-electrode distance (~ 30 μ m), charge trapping effects can be strongly mitigated, making these sensors extremely radiation hard. However, the downscaled sensor structure also lends itself to high electric fields as the bias voltage is increased, motivating investigation of leakage current increase in order to prevent premature electrical breakdown due to impact ionization. In order to assess the characteristics of heavily irradiated samples, using 3D diodes as test devices, we have carried out a dedicated campaign that included several irradiations (γ -rays, neutrons, and protons) at different facilities. In this paper, we report on the electrical characterization of a subset of the irradiated samples, also in comparison to their pre-irradiation properties. Results demonstrate that hadron irradiated devices can be safely operated at a voltage high enough to allow for full depletion (hence high efficiency) also at the maximum fluence foreseen at the HL-LHC.
Multiple sessions of transcranial direct current stimulation and upper extremity rehabilitation in stroke: A review and meta-analysis.

PubMed

Tedesco Triccas, L; Burridge, J H; Hughes, A M; Pickering, R M; Desikan, M; Rothwell, J C; Verheyden, G

2016-01-01

To systematically review the methodology in particular treatment options and outcomes and the effect of multiple sessions of transcranial direct current stimulation (tDCS) with rehabilitation programmes for upper extremity recovery post stroke. A search was conducted for randomised controlled trials involving tDCS and rehabilitation for the upper extremity in stroke. Quality of included studies was analysed using the Modified Downs and Black form. The extent of, and effect of variation in treatment parameters such as anodal, cathodal and bi-hemispheric tDCS on upper extremity outcome measures of impairment and activity were analysed using meta-analysis. Nine studies (371 participants with acute, sub-acute and chronic stroke) were included. Different methodologies of tDCS and upper extremity intervention, outcome measures and timing of assessments were identified. Real tDCS combined with rehabilitation had a small non-significant effect of +0.11 (p=0.44) and +0.24 (p=0.11) on upper extremity impairments and activities at post-intervention respectively. Various tDCS methods have been used in stroke rehabilitation. The evidence so far is not statistically significant, but is suggestive of, at best, a small beneficial effect on upper extremity impairment. Future research should focus on which patients and rehabilitation programmes are likely to respond to different tDCS regimes. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Accurate and fast multiple-testing correction in eQTL studies.

PubMed

Sul, Jae Hoon; Raj, Towfique; de Jong, Simone; de Bakker, Paul I W; Raychaudhuri, Soumya; Ophoff, Roel A; Stranger, Barbara E; Eskin, Eleazar; Han, Buhm

2015-06-04

In studies of expression quantitative trait loci (eQTLs), it is of increasing interest to identify eGenes, the genes whose expression levels are associated with variation at a particular genetic variant. Detecting eGenes is important for follow-up analyses and prioritization because genes are the main entities in biological processes. To detect eGenes, one typically focuses on the genetic variant with the minimum p value among all variants in cis with a gene and corrects for multiple testing to obtain a gene-level p value. For performing multiple-testing correction, a permutation test is widely used. Because of growing sample sizes of eQTL studies, however, the permutation test has become a computational bottleneck in eQTL studies. In this paper, we propose an efficient approach for correcting for multiple testing and assess eGene p values by utilizing a multivariate normal distribution. Our approach properly takes into account the linkage-disequilibrium structure among variants, and its time complexity is independent of sample size. By applying our small-sample correction techniques, our method achieves high accuracy in both small and large studies. We have shown that our method consistently produces extremely accurate p values (accuracy > 98%) for three human eQTL datasets with different sample sizes and SNP densities: the Genotype-Tissue Expression pilot dataset, the multi-region brain dataset, and the HapMap 3 dataset. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.
Importance of benthic prey for fishes in coral reef-associated sediments

USGS Publications Warehouse

DeFelice, R.C.; Parrish, J.D.

2003-01-01

The importance of open, sandy substrate adjacent to coral reefs as habitat and a food source for fishes has been little studied in most shallow tropical waters in the Pacific, including Hawai'i. In this study, in Hanalei Bay, Hiwai'i, we identified and quantified the major invertebrate fauna (larger than 0.5 mm) in the well-characterized sands adjoining the shallow fringing reefs. Concurrently, we identified the fish species that seemed to make substantial use of these sand habitats, estimated their density there, sampled their gut contents to examine trophic links with the sand habitat, and made other observations and collections to determine the times, locations, and types of activity there. A variety of (mostly small) polychaeres were dominant in the sediments at most sampling stations, along with many small crustaceans (e.g., amphipods, isopods, ostracods, and small shrimps) and fair numbers of mollusks (especially bivalves) and small echinoids. Fish guts examined contained ???77% of the total number of benthic taxa collected, including nearly all those just listed. However, fish consumption was selective, and the larger shrimps, crabs, and small cryptic fishes were dominant in the diets of most of the numerous predator taxa. Diets of benthic-feeding fishes showed relatively low specific overlap. The fish fauna in this area included substrate-indifferent pelagics, species with various degrees of reef relatedness, reef-restricted species, and (at the other extreme) permanent cryptic sand dwellers. Data on occurrence and movements of fishes indicated that a band of sandy substrate several tens of meters wide next to the reef was an active area for fishes, and activity was considerably different at different times of day and for fish of different ages. These results imply an important trophic role for the benthos in these near-reef habitats in support of reef-associated fishes.
MEASUREMENT OF SMALL MECHANICAL VIBRATIONS OF BRAIN TISSUE EXPOSED TO EXTREMELY-LOW-FREQUENCY ELECTRIC FIELDS

EPA Science Inventory

Electromagnetic fields can interact with biological tissue both electrically and mechanically. This study investigated the mechanical interaction between brain tissue and an extremely-low-frequency (ELF) electric field by measuring the resultant vibrational amplitude. The exposur...
Using Extreme Groups Strategy When Measures Are Not Normally Distributed.

ERIC Educational Resources Information Center

Fowler, Robert L.

1992-01-01

A Monte Carlo simulation explored how to optimize power in the extreme groups strategy when sampling from nonnormal distributions. Results show that the optimum percent for the extreme group selection was approximately the same for all population shapes, except the extremely platykurtic (uniform) distribution. (SLD)
Ensemble reconstruction of spatio-temporal extreme low-flow events in France since 1871

NASA Astrophysics Data System (ADS)

Caillouet, Laurie; Vidal, Jean-Philippe; Sauquet, Eric; Devers, Alexandre; Graff, Benjamin

2017-06-01

The length of streamflow observations is generally limited to the last 50 years even in data-rich countries like France. It therefore offers too small a sample of extreme low-flow events to properly explore the long-term evolution of their characteristics and associated impacts. To overcome this limit, this work first presents a daily 140-year ensemble reconstructed streamflow dataset for a reference network of near-natural catchments in France. This dataset, called SCOPE Hydro (Spatially COherent Probabilistic Extended Hydrological dataset), is based on (1) a probabilistic precipitation, temperature, and reference evapotranspiration downscaling of the Twentieth Century Reanalysis over France, called SCOPE Climate, and (2) continuous hydrological modelling using SCOPE Climate as forcings over the whole period. This work then introduces tools for defining spatio-temporal extreme low-flow events. Extreme low-flow events are first locally defined through the sequent peak algorithm using a novel combination of a fixed threshold and a daily variable threshold. A dedicated spatial matching procedure is then established to identify spatio-temporal events across France. This procedure is furthermore adapted to the SCOPE Hydro 25-member ensemble to characterize in a probabilistic way unrecorded historical events at the national scale. Extreme low-flow events are described and compared in a spatially and temporally homogeneous way over 140 years on a large set of catchments. Results highlight well-known recent events like 1976 or 1989-1990, but also older and relatively forgotten ones like the 1878 and 1893 events. These results contribute to improving our knowledge of historical events and provide a selection of benchmark events for climate change adaptation purposes. Moreover, this study allows for further detailed analyses of the effect of climate variability and anthropogenic climate change on low-flow hydrology at the scale of France.
Three dimensional reconstruction of InGaN nanodisks in GaN nanowires: Improvement of the nanowire sample preparation to avoid missing wedge effects

NASA Astrophysics Data System (ADS)

Gries, Katharina Ines; Schlechtweg, Julian; Hille, Pascal; Schörmann, Jörg; Eickhoff, Martin; Volz, Kerstin

2017-10-01

Scanning transmission electron microscopy is an extremely useful method to image small features with a size in the range of a few nanometers and below. But it must be taken into account that such images are projections of the sample and do not necessarily represent the real three dimensional structure of the specimen. By applying electron tomography this problem can be overcome. In our work GaN nanowires including InGaN nanodisks were investigated. To reduce the effect of the missing wedge a single nanowire was removed from the underlying silicon substrate using a manipulator needle and attached to a tomography holder. Since this sample exhibits the same thickness of few tens of nanometers in all directions normal to the tilt axis, this procedure allows a sample tilt of ±90°. Reconstruction of the received data reveals a split of the InGaN nanodisks into a horizontal continuation of the (0 0 0 1 bar) central facet and a declined {1 0 1 bar l} facet (with l = -2 or -3).
Coherent Detector for Near-Angle Scattering and Polarization Characterization of Telescope Mirror Coatings

NASA Technical Reports Server (NTRS)

Macenka, Steven A.; Chipman, Russell A.; Daugherty, Brian J.; McClain, Stephen C.

2012-01-01

A report discusses the difficulty of measuring scattering properties of coated mirrors extremely close to the specular reflection peak. A prototype Optical Hetero dyne Near-angle Scatterometer (OHNS) was developed. Light from a long-coherence-length (>150 m) 532-nm laser is split into two arms. Acousto-optic modulators frequency shift the sample and reference beams, establishing a fixed beat frequency between the beams. The sample beam is directed at very high f/# onto a mirror sample, and the point spread function (PSF) formed after the mirror sample is scanned with a pinhole. This light is recombined by a non-polarizing beam splitter and measured through heterodyne detection with a spectrum analyzer. Polarizers control the illuminated and analyzed polarization states, allowing the polarization dependent scatter to be measured. The bidirectional reflective or scattering distribution function is normally measured through use of a scattering goniometer instrument. The instrumental beam width (collection angle span) over which the scatterometer responds is typically many degrees. The OHNS enables measurement at angles as small as the first Airy disk diameter.
Minimum important differences for the patient-specific functional scale, 4 region-specific outcome measures, and the numeric pain rating scale.

PubMed

Abbott, J Haxby; Schmitt, John

2014-08-01

Multicenter, prospective, longitudinal cohort study. To investigate the minimum important difference (MID) of the Patient-Specific Functional Scale (PSFS), 4 region-specific outcome measures, and the numeric pain rating scale (NPRS) across 3 levels of patient-perceived global rating of change in a clinical setting. The MID varies depending on the external anchor defining patient-perceived "importance." The MID for the PSFS has not been established across all body regions. One thousand seven hundred eight consecutive patients with musculoskeletal disorders were recruited from 5 physical therapy clinics. The PSFS, NPRS, and 4 region-specific outcome measures-the Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale-were assessed at the initial and final physical therapy visits. Global rating of change was assessed at the final visit. MID was calculated for the PSFS and NPRS (overall and for each body region), and for each region-specific outcome measure, across 3 levels of change defined by the global rating of change (small, medium, large change) using receiver operating characteristic curve methodology. The MID for the PSFS (on a scale from 0 to 10) ranged from 1.3 (small change) to 2.3 (medium change) to 2.7 (large change), and was relatively stable across body regions. MIDs for the NPRS (-1.5 to -3.5), Oswestry Disability Index (-12), Neck Disability Index (-14), Upper Extremity Functional Index (6 to 11), and Lower Extremity Functional Scale (9 to 16) are also reported. We reported the MID for small, medium, and large patient-perceived change on the PSFS, NPRS, Oswestry Disability Index, Neck Disability Index, Upper Extremity Functional Index, and Lower Extremity Functional Scale for use in clinical practice and research.
Matter-Radiation Interactions in Extremes

Science.gov Websites

to resolve this capability gap. An experimental explosive is shown igniting during small-scale impact testing. An experimental explosive is shown igniting during small-scale impact testing. Accelerating in to
The Robust Relationship Between Extreme Precipitation and Convective Organization in Idealized Numerical Modeling Simulations

NASA Astrophysics Data System (ADS)

Bao, Jiawei; Sherwood, Steven C.; Colin, Maxime; Dixit, Vishal

2017-10-01

The behavior of tropical extreme precipitation under changes in sea surface temperatures (SSTs) is investigated with the Weather Research and Forecasting Model (WRF) in three sets of idealized simulations: small-domain tropical radiative-convective equilibrium (RCE), quasi-global "aquapatch", and RCE with prescribed mean ascent from the tropical band in the aquapatch. We find that, across the variations introduced including SST, large-scale circulation, domain size, horizontal resolution, and convective parameterization, the change in the degree of convective organization emerges as a robust mechanism affecting extreme precipitation. Higher ratios of change in extreme precipitation to change in mean surface water vapor are associated with increases in the degree of organization, while lower ratios correspond to decreases in the degree of organization. The spread of such changes is much larger in RCE than aquapatch tropics, suggesting that small RCE domains may be unreliable for assessing the temperature-dependence of extreme precipitation or convective organization. When the degree of organization does not change, simulated extreme precipitation scales with surface water vapor. This slightly exceeds Clausius-Clapeyron (CC) scaling, because the near-surface air warms 10-25% faster than the SST in all experiments. Also for simulations analyzed here with convective parameterizations, there is an increasing trend of organization with SST.
Extreme Magnitude Earthquakes and their Economical Consequences

NASA Astrophysics Data System (ADS)

Chavez, M.; Cabrera, E.; Ashworth, M.; Perea, N.; Emerson, D.; Salazar, A.; Moulinec, C.

2011-12-01

The frequency of occurrence of extreme magnitude earthquakes varies from tens to thousands of years, depending on the considered seismotectonic region of the world. However, the human and economic losses when their hypocenters are located in the neighborhood of heavily populated and/or industrialized regions, can be very large, as recently observed for the 1985 Mw 8.01 Michoacan, Mexico and the 2011 Mw 9 Tohoku, Japan, earthquakes. Herewith, a methodology is proposed in order to estimate the probability of exceedance of: the intensities of extreme magnitude earthquakes, PEI and of their direct economical consequences PEDEC. The PEI are obtained by using supercomputing facilities to generate samples of the 3D propagation of extreme earthquake plausible scenarios, and enlarge those samples by Monte Carlo simulation. The PEDEC are computed by using appropriate vulnerability functions combined with the scenario intensity samples, and Monte Carlo simulation. An example of the application of the methodology due to the potential occurrence of extreme Mw 8.5 subduction earthquakes on Mexico City is presented.
Chronic Health Risks in Commercial Fishermen: A Cross-Sectional Analysis from a Small Rural Fishing Village in Alaska.

PubMed

Eckert, Carly; Baker, Torie; Cherry, Debra

2018-01-01

The purpose of this study is to evaluate chronic health risks before and during the fishing season in a sample of commercial fishermen, addressing the NIOSH priority of Total Worker Health TM . Gillnet license holders in Cordova, Alaska (n = 607) were contacted to participate in a preseason survey (March 2015) assessing health behaviors. A mid-season survey (July 2015) was also conducted. Physical exams and additional assessments were performed on a subset of these fishermen. Sixty-six fishermen participated in the preseason survey and 38 participated in the mid-season survey. The study population was overwhelmingly white males with an average age of 49. The average BMI was 27 with 70% of the participants overweight or obese. Nearly 80% of the sample considered their health good or better. Participants reported longer working hours, less sleep, and less aerobic exercise during the fishing season (P < .05). FitBit TM monitoring (n = 8) confirmed less sleep and fewer steps during fishing season. In one exam (n = 20), 80% of participants showed measured hearing loss at 4 kz (conversation range), and 70% had one or more upper extremity disorders, including 40% with rotator cuff tendonitis. The prevalence of hearing loss, upper extremity disorders, and sleep apnea risk factors were higher than in the general population both before and during the fishing season. Occupational factors including exposure to noise, the upper extremity demands of gillnetting, and long working hours while fishing exacerbate these chronic health conditions. Health promotion programs targeted toward these conditions may present opportunities for improving total worker health.
The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

PubMed

Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

2016-06-03

The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Label-Free Biomedical Imaging Using High-Speed Lock-In Pixel Sensor for Stimulated Raman Scattering

PubMed Central

Mars, Kamel; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Yamada, Takahiro

2017-01-01

Raman imaging eliminates the need for staining procedures, providing label-free imaging to study biological samples. Recent developments in stimulated Raman scattering (SRS) have achieved fast acquisition speed and hyperspectral imaging. However, there has been a problem of lack of detectors suitable for MHz modulation rate parallel detection, detecting multiple small SRS signals while eliminating extremely strong offset due to direct laser light. In this paper, we present a complementary metal-oxide semiconductor (CMOS) image sensor using high-speed lock-in pixels for stimulated Raman scattering that is capable of obtaining the difference of Stokes-on and Stokes-off signal at modulation frequency of 20 MHz in the pixel before reading out. The generated small SRS signal is extracted and amplified in a pixel using a high-speed and large area lateral electric field charge modulator (LEFM) employing two-step ion implantation and an in-pixel pair of low-pass filter, a sample and hold circuit and a switched capacitor integrator using a fully differential amplifier. A prototype chip is fabricated using 0.11 μm CMOS image sensor technology process. SRS spectra and images of stearic acid and 3T3-L1 samples are successfully obtained. The outcomes suggest that hyperspectral and multi-focus SRS imaging at video rate is viable after slight modifications to the pixel architecture and the acquisition system. PMID:29120358
Label-Free Biomedical Imaging Using High-Speed Lock-In Pixel Sensor for Stimulated Raman Scattering.

PubMed

Mars, Kamel; Lioe, De Xing; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Yamada, Takahiro; Hashimoto, Mamoru

2017-11-09

Raman imaging eliminates the need for staining procedures, providing label-free imaging to study biological samples. Recent developments in stimulated Raman scattering (SRS) have achieved fast acquisition speed and hyperspectral imaging. However, there has been a problem of lack of detectors suitable for MHz modulation rate parallel detection, detecting multiple small SRS signals while eliminating extremely strong offset due to direct laser light. In this paper, we present a complementary metal-oxide semiconductor (CMOS) image sensor using high-speed lock-in pixels for stimulated Raman scattering that is capable of obtaining the difference of Stokes-on and Stokes-off signal at modulation frequency of 20 MHz in the pixel before reading out. The generated small SRS signal is extracted and amplified in a pixel using a high-speed and large area lateral electric field charge modulator (LEFM) employing two-step ion implantation and an in-pixel pair of low-pass filter, a sample and hold circuit and a switched capacitor integrator using a fully differential amplifier. A prototype chip is fabricated using 0.11 μm CMOS image sensor technology process. SRS spectra and images of stearic acid and 3T3-L1 samples are successfully obtained. The outcomes suggest that hyperspectral and multi-focus SRS imaging at video rate is viable after slight modifications to the pixel architecture and the acquisition system.
Antenatal antecedents of a small head circumference at age 24-months post-term equivalent in a sample of infants born before the 28th post-menstrual week.

PubMed

Leviton, Alan; Kuban, Karl; Allred, Elizabeth N; Hecht, Jonathan L; Onderdonk, Andrew; O'Shea, T Michael; McElrath, Thomas; Paneth, Nigel

2010-08-01

Little is known about the antecedents of microcephaly in early childhood among children born at extremely low gestational age. To identify some of the antecedents of microcephaly at age two years among children born before the 28th week of gestation. Observational cohort study. 1004 infants born before the 28th week of gestation. Head circumference Z-scores of <-2 and >or=-2, <-1. Risk of microcephaly and a less severely restricted head circumference decreased monotonically with increasing gestational age. After adjusting for gestational age and other potential confounders, the risk of microcephaly at age 2 years was increased if microcephaly was present at birth [odds ratio: 8.8 ((95% confidence interval: 3.7, 21)], alpha hemolytic Streptococci were recovered from the placenta parenchyma [2.9 (1.2, 6.9)], the child was a boy [2.8 (1.6, 4.9)], and the child's mother was not married [2.5 (1.5, 4.3)]. Antecedents associated not with microcephaly, but with a less extreme reduction in head circumference were recovery of Propionibacterium sp from the placenta parenchyma [2.9 (1.5, 5.5)], tobacco exposure [2.0 (1.4, 3.0)], and increased syncytial knots in the placenta [2.0 (1.2, 3.2)]. Although microcephaly at birth predicts a small head circumference at 2 years among children born much before term, pregnancy and maternal characteristics provide supplemental information about the risk of a small head circumference years later. Two findings appear to be novel. Tobacco exposure during pregnancy, and organisms recovered from the placenta predict reduced head circumference at age two years. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
Antenatal antecedents of a small head circumference at age 24-months post-term equivalent in a sample of infants born before the 28th post-menstrual week

PubMed Central

Leviton, Alan; Kuban, Karl; Allred, Elizabeth N.; Hecht, Jonathan L.; Onderdonk, Andrew; O'Shea, T. Michael; McElrath, Thomas; Paneth, Nigel

2010-01-01

Background Little is known about the antecedents of microcephaly in early childhood among children born at extremely low gestational age. Aim To identify some of the antecedents of microcephaly at age two years among children born before the 28th week of gestation. Study design Observational cohort study. Subjects 1004 infants born before the 28th week of gestation. Outcome measures Head circumference Z-scores of <−2 and ≥−2, <−1. Results Risk of microcephaly and a less severely restricted head circumference decreased monotonically with increasing gestational age. After adjusting for gestational age and other potential confounders, the risk of microcephaly at age 2 years was increased if microcephaly was present at birth [odds ratio: 8.8 ((95% confidence interval: 3.7, 21)], alpha hemolytic Streptococci were recovered from the placenta parenchyma [2.9 (1.2, 6.9)], the child was a boy [2.8 (1.6, 4.9)], and the child's mother was not married [2.5 (1.5, 4.3)]. Antecedents associated not with microcephaly, but with a less extreme reduction in head circumference were recovery of Propionibacterium sp from the placenta parenchyma [2.9 (1.5, 5.5)], tobacco exposure [2.0 (1.4, 3.0)], and increased syncytial knots in the placenta [2.0 (1.2, 3.2)]. Conclusions Although microcephaly at birth predicts a small head circumference at 2 years among children born much before term, pregnancy and maternal characteristics provide supplemental information about the risk of a small head circumference years later. Two findings appear to be novel. Tobacco exposure during pregnancy, and organisms recovered from the placenta predict reduced head circumference at age two years. PMID:20674197
Within-country variation of salt intake assessed via urinary excretion in Japan: a multilevel analysis in all 47 prefectures.

PubMed

Uechi, Ken; Asakura, Keiko; Masayasu, Shizuko; Sasaki, Satoshi

2017-06-01

Salt intake in Japan remains high; therefore, exploring within-country variation in salt intake and its cause is an important step in the establishment of salt reduction strategies. However, no nationwide evaluation of this variation has been conducted by urinalysis. We aimed to clarify whether within-country variation in salt intake exists in Japan after adjusting for individual characteristics. Healthy men (n=1027) and women (n=1046) aged 20-69 years were recruited from all 47 prefectures of Japan. Twenty-four-hour sodium excretion was estimated using three spot urine samples collected on three nonconsecutive days. The study area was categorized into 12 regions defined by the National Health and Nutrition Survey Japan. Within-country variation in sodium excretion was estimated as a population (region)-level variance using a multilevel model with random intercepts, with adjustment for individual biological, socioeconomic and dietary characteristics. Estimated 24 h sodium excretion was 204.8 mmol per day in men and 155.7 mmol per day in women. Sodium excretion was high in the Northeastern region. However, population-level variance was extremely small after adjusting for individual characteristics (0.8 and 2% of overall variance in men and women, respectively) compared with individual-level variance (99.2 and 98% of overall variance in men and women, respectively). Among individual characteristics, greater body mass index, living with a spouse and high miso-soup intake were associated with high sodium excretion in both sexes. Within-country variation in salt intake in Japan was extremely small compared with individual-level variation. Salt reduction strategies for Japan should be comprehensive and should not address the small within-country differences in intake.
Virtual reality gaming in the rehabilitation of the upper extremities post-stroke.

PubMed

Yates, Michael; Kelemen, Arpad; Sik Lanyi, Cecilia

2016-01-01

Occurrences of strokes often result in unilateral upper limb dysfunction. Dysfunctions of this nature frequently persist and can present chronic limitations to activities of daily living. Research into applying virtual reality gaming systems to provide rehabilitation therapy have seen resurgence. Themes explored in stroke rehab for paretic limbs are action observation and imitation, versatility, intensity and repetition and preservation of gains. Fifteen articles were ultimately selected for review. The purpose of this literature review is to compare the various virtual reality gaming modalities in the current literature and ascertain their efficacy. The literature supports the use of virtual reality gaming rehab therapy as equivalent to traditional therapies or as successful augmentation to those therapies. While some degree of rigor was displayed in the literature, small sample sizes, variation in study lengths and therapy durations and unequal controls reduce generalizability and comparability. Future studies should incorporate larger sample sizes and post-intervention follow-up measures.
Ultraviolet spectroscopic breath analysis using hollow-optical fiber as gas cell

NASA Astrophysics Data System (ADS)

Iwata, T.; Katagiri, T.; Matsuura, Y.

2017-02-01

For breath analysis on ultraviolet absorption spectroscopy, an analysis system using a hollow optical fiber as gas cell is developed. The hollow optical fiber functions as a long path and extremely small volume gas cell. Firstly, the measurement sensitivity of the system is evaluated by using NO gas as a gas sample. The result shows that NO gas with 50 ppb concentration is measured by using a system with a laser-driven, high intensity light source and a 3-meter long, aluminum-coated hollow optical fiber. Then an absorption spectrum of breath sample is measured in the wavelength region of around 200-300 nm and from the spectrum, it is found that the main absorbing components in breath were H2O, isoprene, and O3 converted from O2 by radiation of ultraviolet light. Then the concentration of isoprene in breath is estimated by using multiple linear regression analysis.
Testing the significance of a correlation with nonnormal data: comparison of Pearson, Spearman, transformation, and resampling approaches.

PubMed

Bishara, Anthony J; Hittner, James B

2012-09-01

It is well known that when data are nonnormally distributed, a test of the significance of Pearson's r may inflate Type I error rates and reduce power. Statistics textbooks and the simulation literature provide several alternatives to Pearson's correlation. However, the relative performance of these alternatives has been unclear. Two simulation studies were conducted to compare 12 methods, including Pearson, Spearman's rank-order, transformation, and resampling approaches. With most sample sizes (n ≥ 20), Type I and Type II error rates were minimized by transforming the data to a normal shape prior to assessing the Pearson correlation. Among transformation approaches, a general purpose rank-based inverse normal transformation (i.e., transformation to rankit scores) was most beneficial. However, when samples were both small (n ≤ 10) and extremely nonnormal, the permutation test often outperformed other alternatives, including various bootstrap tests.
A transmission electron microscopy study of the deformation behavior underneath nanoindents in nanoscale Al-TiN multilayered composites

NASA Astrophysics Data System (ADS)

Bhattacharyya, D.; Mara, N. A.; Dickerson, P.; Hoagland, R. G.; Misra, A.

2010-05-01

Nanoscale multilayered Al-TiN composites were deposited using the dc magnetron sputtering technique in two different layer thickness ratios, Al : TiN = 1 : 1 and Al : TiN = 9 : 1. The Al layer thickness varied from 2 nm to 450 nm. The hardness of the samples was tested by nanoindentation using a Berkovich tip. Cross-sectional transmission electron microscopy (TEM) was carried out on samples extracted with focused ion beam from below the nanoindents. The results of the hardness tests on the Al-TiN multilayers with two different thickness ratios are presented, together with observations from the cross-sectional TEM studies of the regions underneath the indents. These studies revealed remarkable strength in the multilayers, as well as some very interesting deformation behavior in the TiN layers at extremely small length scales, where the hard TiN layers undergo co-deformation with the Al layers.
Self-Reported Extremely Adverse Life Events and Longitudinal Changes in Five-Factor Model Personality Traits in an Urban Sample

PubMed Central

Löckenhoff, Corinna E.; Terracciano, Antonio; Patriciu, Nicholas S.; Eaton, William W.; Costa, Paul T.

2009-01-01

This study examined longitudinal personality change in response to extremely adverse life events in a sample (N = 458) drawn from the East Baltimore Epidemiologic Catchment Area study. Five-factor model personality traits were assessed twice over an average interval of 8 years. Twenty-five percent of the participants reported an extremely horrifying or frightening event within 2 years before the second personality assessment. Relative to the rest of the sample, they showed increases in neuroticism, decreases in the compliance facet of agreeableness, and decreases in openness to values. Baseline personality was unrelated to future events, but among participants who reported extreme events, lower extraversion and/or conscientiousness at baseline as well as longitudinal increases in neuroticism predicted lower mental health at follow-up. PMID:19230009
Effect of Nb addition on microstructure and corrosion resistance of novel stainless steels fabricated by direct laser metal deposition

NASA Astrophysics Data System (ADS)

Wu, S. Q.; Zhang, C. H.; Zhang, S.; Wang, Q.; Liu, Y.; Abdullah, Adil O.

2018-03-01

The study demonstrated the successful fabrication of novel stainless steels by direct laser metal deposition with the aim of investigating the impact of niobium content (Nb = 0, 0.25, 0.75, 1.25 wt%) on their microstructure and electrochemical properties. The microstructure and phase evolution of the as-built stainless steels were studied using scanning electron microscope (SEM) and electron back-scatter diffraction (EBSD). Corrosion behavior of the samples was evaluated using electrochemical workstation in 3.5 wt% NaCl. Experimental results have shown that the crystal structure of as-built stainless steels was BCC with a small trace of dispersive carbides and FCC phase. Grain refinement was observed with increasing niobium content. Large-angle boundaries were obtained in different Nb-containing samples with distribution from 50° to 60°. An increase in niobium content extremely improved the corrosion resistance of as-built stainless steels and the as-built samples with 1.25 wt% exhibited the best corrosion resistance among the tested samples as indicated by its lowest corrosion rate, which was an order of magnitude lower than that of Nb-free samples.
Sampling and analysis of aircraft engine cold start particles and demonstration of an electrostatic personal particle sampler.

PubMed

Armendariz, Alfredo; Leith, David; Boundy, Maryanne; Goodman, Randall; Smith, Les; Carlton, Gary

2003-01-01

Aircraft engines emit an aerosol plume during startup in extremely cold weather that can drift into areas occupied by flightline ground crews. This study tested a personal sampler used to assess exposure to particles in the plume under challenging field conditions. Area and personal samples were taken at two U.S. Air Force (USAF) flightlines during the winter months. Small tube-and-wire electrostatic precipitators (ESPs) were mounted on a stationary stand positioned behind the engines to sample the exhaust. Other ESPs were worn by ground crews to sample breathing zone concentrations. In addition, an aerodynamic particle sizer 3320 (APS) was used to determine the size distribution of the particles. Samples collected with the ESP were solvent extracted and analyzed with gas chromatography-mass spectrometry. Results indicated that the plume consisted of up to 75 mg/m(3) of unburned jet fuel particles. The APS showed that nearly the entire particle mass was respirable, because the plumes had mass median diameters less than 2 micro m. These tests demonstrated that the ESP could be used at cold USAF flightlines to perform exposure assessments to the cold start particles.
Drug Loading Capacity of Environmentally Sensitive Polymeric Microgels

NASA Astrophysics Data System (ADS)

McDonough, Ryan; Streletzky, Kiril; Bayachou, Mekki; Peiris, Pubudu

2009-10-01

Microgel nanoparticles consisting of cross-linked polymer hydroxypropyl cellulose chains have a temperature dependent volume phase transition, prompting the use of microgels for controlled drug transport. Drug particles aggregate in the slightly hydrophobic interior of microgels. Microgels are stored in equilibrium until the critical temperature (Tv) is reached and the volume phase transition limits available space, thus expelling the drugs. Our study was designed to test this property of microgels using amperometric electrochemical methods. A critical assumption was that small molecules inside microgels would not interact via diffusion with the electrode surface and thus total current would be decreased across the electrodes in a microgel sample. A room temperature (Troom) flow amperometric measurement comparing microgel/tylenol solution with control tylenol samples yielded about 20% tylenol concentration reduction of the microgel sample. Results from the steady state electrochemical experiment confirm the presence of about 20% tylenol concentration drop of the microgel sample compared to control sample at Troom. Using the steady-state experiment with a cyclic temperature ramp from Troom to beyond Tv showed that the tylenol concentration change between the temperature extremes was greater for the microgel solution than for the control solution.
The balance and harmony of control power for a combat aircraft in tactical maneuvering

NASA Technical Reports Server (NTRS)

Bocvarov, Spiro; Cliff, Eugene M.; Lutze, Frederick H.

1992-01-01

An analysis is presented for a family of regular extremal attitude-maneuvers for the High Angle-of-Attack Research Vehicle that has thrust-vectoring capability. Different levels of dynamic coupling are identified in the combat aircraft attitude model, and the characteristic extremal-family motion is explained. It is shown why the extremal-family trajectories develop small sideslip-angles, a highly desirable feature from a practical viewpoint.
Susceptibility to Mortality in Weather Extremes: Effect Modification by Personal and Small Area Characteristics In a Multi-City Case-Only Analysis

PubMed Central

Zanobetti, Antonella; O’Neill, Marie S.; Gronlund, Carina J.; Schwartz, Joel D

2015-01-01

Background Extremes of temperature have been associated with short-term increases in daily mortality. We identified subpopulations with increased susceptibility to dying during temperature extremes, based on personal demographics, small-area characteristics and preexisting medical conditions. Methods We examined Medicare participants in 135 U.S. cities and identified preexisting conditions based on hospitalization records prior to their deaths, from 1985–2006. Personal characteristics were obtained from the Medicare records, and area characteristics were assigned based on zip-code of residence. We conducted a case-only analysis of over 11 million deaths, and evaluated modification of the risk of dying associated with extremely hot days and extremely cold days, continuous temperatures, and water-vapor pressure. Modifiers included preexisting conditions, personal characteristics, zip-code-level population characteristics, and land-cover characteristics. For each effect modifier, a city-specific logistic regression model was fitted and then an overall national estimate was calculated using meta-analysis. Results People with certain preexisting conditions were more susceptible to extreme heat, with an additional 6% (95% confidence interval= 4% – 8%) increase in the risk of dying on an extremely hot day in subjects with previous admission for atrial fibrillation, an additional 8% (4%–12%) in subjects with Alzheimer disease, and an additional 6% (3%–9%) in subjects with dementia. Zip-code level and personal characteristics were also associated with increased susceptibility to temperature. Conclusions We identified several subgroups of the population who are particularly susceptible to temperature extremes, including persons with atrial fibrillation. PMID:24045717
Weak linkage between the heaviest rainfall and tallest storms.

PubMed

Hamada, Atsushi; Takayabu, Yukari N; Liu, Chuntao; Zipser, Edward J

2015-02-24

Conventionally, the heaviest rainfall has been linked to the tallest, most intense convective storms. However, the global picture of the linkage between extreme rainfall and convection remains unclear. Here we analyse an 11-year record of spaceborne precipitation radar observations and establish that a relatively small fraction of extreme convective events produces extreme rainfall rates in any region of the tropics and subtropics. Robust differences between extreme rainfall and convective events are found in the rainfall characteristics and environmental conditions, irrespective of region; most extreme rainfall events are characterized by less intense convection with intense radar echoes not extending to extremely high altitudes. Rainfall characteristics and environmental conditions both indicate the importance of warm-rain processes in producing extreme rainfall rates. Our results demonstrate that, even in regions where severe convective storms are representative extreme weather events, the heaviest rainfall events are mostly associated with less intense convection.
Microplate-Based Method for High-Throughput Screening (HTS) of Chromatographic Conditions Studies for Recombinant Protein Purification.

PubMed

Carvalho, Rimenys J; Cruz, Thayana A

2018-01-01

High-throughput screening (HTS) systems have emerged as important tools to provide fast and low cost evaluation of several conditions at once since it requires small quantities of material and sample volumes. These characteristics are extremely valuable for experiments with large number of variables enabling the application of design of experiments (DoE) strategies or simple experimental planning approaches. Once, the capacity of HTS systems to mimic chromatographic purification steps was established, several studies were performed successfully including scale down purification. Here, we propose a method for studying different purification conditions that can be used for any recombinant protein, including complex and glycosylated proteins, using low binding filter microplates.
Separation of negatively charged carbohydrates by capillary electrophoresis.

PubMed

Linhardt, R J; Pervin, A

1996-01-12

Capillary electrophoresis (CE) has recently emerged as a highly promising technique consuming an extremely small amount of sample and capable of the rapid, high-resolution separation, characterization, and quantitation of analytes. CE has been used for the separation of biopolymers, including acidic carbohydrates. Since CE is basically an analytical method for ions, acidic carbohydrates that give anions in weakly acid, neutral, or alkaline media are often the direct objects of this method. The scope of this review is limited to the use of CE for the analysis of carbohydrates containing carboxylate, sulfate, and phosphate groups as well as neutral carbohydrates that have been derivatized to incorporate strongly acidic functionality, such as sulfonate groups.
Kurtosis as Peakedness, 1905 - 2014. R.I.P.

PubMed

Westfall, Peter H

The incorrect notion that kurtosis somehow measures "peakedness" (flatness, pointiness or modality) of a distribution is remarkably persistent, despite attempts by statisticians to set the record straight. This article puts the notion to rest once and for all. Kurtosis tells you virtually nothing about the shape of the peak - its only unambiguous interpretation is in terms of tail extremity; i.e., either existing outliers (for the sample kurtosis) or propensity to produce outliers (for the kurtosis of a probability distribution). To clarify this point, relevant literature is reviewed, counterexample distributions are given, and it is shown that the proportion of the kurtosis that is determined by the central μ ± σ range is usually quite small.
An S-shaped relationship between changes in appraisals and changes in emotions.

PubMed

Tong, Eddie M W; Ellsworth, Phoebe C; Bishop, George D

2009-12-01

Previous research on appraisal theories of emotion has shown that emotions and appraisals are related but has not specified the nature of the relationships. This research examined the functional forms of appraisal-emotion relationships and demonstrated that for all seven appraisals studied, appraisals relate to emotions in an S-shaped (ogival) fashion: Changes in appraisals at extreme levels are associated with only small changes in emotions, but changes at moderate levels are associated with substantial changes in emotions. With a few exceptions, ogival relationships were found for the relationships between seven appraisals (Goal Achievement Expectancy, Agency, Control, Certainty, Fairness, Pleasantness, and Motive Congruence) and numerous relevant emotions across different sample-types, cultures, and methods.

Invited Article: Indenter materials for high temperature nanoindentation

NASA Astrophysics Data System (ADS)

Wheeler, J. M.; Michler, J.

2013-10-01

As nanoindentation at high temperatures becomes increasingly popular, a review of indenter materials for usage at high temperatures is instructive for identifying appropriate indenter-sample materials combinations to prevent indenter loss or failure due to chemical reactions or wear during indentation. This is an important consideration for nanoindentation as extremely small volumes of reacted indenter material will have a significant effect on measurements. The high temperature hardness, elastic modulus, thermal properties, and chemical reactivities of diamond, boron carbide, silicon carbide, tungsten carbide, cubic boron nitride, and sapphire are discussed. Diamond and boron carbide show the best elevated temperature hardness, while tungsten carbide demonstrates the lowest chemical reactivity with the widest array of elements.
The multi-purpose three-axis spectrometer (TAS) MIRA at FRM II

NASA Astrophysics Data System (ADS)

Georgii, R.; Weber, T.; Brandl, G.; Skoulatos, M.; Janoschek, M.; Mühlbauer, S.; Pfleiderer, C.; Böni, P.

2018-02-01

The cold-neutron three-axis spectrometer MIRA is an instrument optimized for low-energy excitations. Its excellent intrinsic Q-resolution makes it ideal for studying incommensurate magnetic systems (elastic and inelastic). MIRA is at the forefront of using advanced neutron focusing optics such as elliptic guides, which enable the investigation of small samples under extreme conditions. Another advantage of MIRA is the modular assembly allowing for instrumental adaption to the needs of the experiment within a few hours. The development of new methods such as the spin-echo technique MIEZE is another important application at MIRA. Scientific topics include the investigation of complex inter-metallic alloys and spectroscopy on incommensurate magnetic structures.
Compositional patterns in the genomes of unicellular eukaryotes

PubMed Central

2013-01-01

Background The genomes of multicellular eukaryotes are compartmentalized in mosaics of isochores, large and fairly homogeneous stretches of DNA that belong to a small number of families characterized by different average GC levels, by different gene concentration (that increase with GC), different chromatin structures, different replication timing in the cell cycle, and other different properties. A question raised by these basic results concerns how far back in evolution the compartmentalized organization of the eukaryotic genomes arose. Results In the present work we approached this problem by studying the compositional organization of the genomes from the unicellular eukaryotes for which full sequences are available, the sample used being representative. The average GC levels of the genomes from unicellular eukaryotes cover an extremely wide range (19%-60% GC) and the compositional patterns of individual genomes are extremely different but all genomes tested show a compositional compartmentalization. Conclusions The average GC range of the genomes of unicellular eukaryotes is very broad (as broad as that of prokaryotes) and individual compositional patterns cover a very broad range from very narrow to very complex. Both features are not surprising for organisms that are very far from each other both in terms of phylogenetic distances and of environmental life conditions. Most importantly, all genomes tested, a representative sample of all supergroups of unicellular eukaryotes, are compositionally compartmentalized, a major difference with prokaryotes. PMID:24188247
Focusing adaptive-optics for neutron spectroscopy at extreme conditions

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

Simeoni, G. G., E-mail: ggsimeoni@outlook.com; Physics Department E13, Technical University of Munich, D-85748 Garching; Valicu, R. G.

2015-12-14

Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well as for the investigation of materials and chemical-physical properties. For all these kinds of studies, an increased neutron flux over a small sample area is needed. The prototype of a focusing neutron guide component, developed and produced completely at the neutron source FRM II in Garching (Germany), has been installed at the time-of-flight (TOF) disc-chopper neutron spectrometer TOFTOF and came into routine-operation. The design is based on the compressed Archimedes' mirror concept for finite-size divergent sources. It represents a uniquemore » device combining the supermirror technology with Adaptive Optics, suitable for broad-bandwidth thermal-cold TOF neutron spectroscopy (here optimized for 1.4–10 Å). It is able to squeeze the beam cross section down to a square centimeter, with a more than doubled signal-to-background ratio, increased efficiency at high scattering angles, and improved symmetry of the elastic resolution function. We present a comparison between the simulated and measured beam cross sections, as well as the performance of the instrument within real experiments. This work intends to show the unprecedented opportunities achievable at already existing instruments, along with useful guidelines for the design and construction of next-generation neutron spectrometers.« less
Exploring the links between the phenomenology of creativity and bipolar disorder.

PubMed

Taylor, Katherine; Fletcher, I; Lobban, F

2015-03-15

The links between bipolar disorder (BD) and creativity have historically attracted academic and public interest. Previous research highlights common characteristics of people considered to be highly creative, and those diagnosed with BD, including extraversion, impulsivity, divergent thinking and high motivation (Ma, 2009). In the first phenomenological study focussing on the links between creativity and extreme mood, an Interpretative Phenomenological Analysis (IPA) approach was used to collect and analyse in-depth interview data from seven people diagnosed with BD in the UK. Four key themes were constructed to reflect and convey the collective accounts: 1. High mood leads to an expanding mind; 2. Full steam ahead; 3. A reciprocal relationship between mood and creativity 4. Reframing bipolar experiences through creative activity. Participants were a small sample of people who were identified as having BD on the basis of a clinical diagnosis and Mood Disorders screening Questionnaire (MDQ), and who defined themselves as creative without further corroboration. Among this sample, creativity was recognised as a valued aspect of BD. Clinical services may usefully draw on creative resources to aid assessment and formulation, and even utilise the effects of creativity on the management of mood. Research demonstrates a high prevalence of non-adherence to medication among persons with BD and this ambivalence might be better understood when the links between extreme mood and creativity are considered. Copyright © 2015. Published by Elsevier B.V.
Extreme events and event size fluctuations in biased random walks on networks.

PubMed

Kishore, Vimal; Santhanam, M S; Amritkar, R E

2012-05-01

Random walk on discrete lattice models is important to understand various types of transport processes. The extreme events, defined as exceedences of the flux of walkers above a prescribed threshold, have been studied recently in the context of complex networks. This was motivated by the occurrence of rare events such as traffic jams, floods, and power blackouts which take place on networks. In this work, we study extreme events in a generalized random walk model in which the walk is preferentially biased by the network topology. The walkers preferentially choose to hop toward the hubs or small degree nodes. In this setting, we show that extremely large fluctuations in event sizes are possible on small degree nodes when the walkers are biased toward the hubs. In particular, we obtain the distribution of event sizes on the network. Further, the probability for the occurrence of extreme events on any node in the network depends on its "generalized strength," a measure of the ability of a node to attract walkers. The generalized strength is a function of the degree of the node and that of its nearest neighbors. We obtain analytical and simulation results for the probability of occurrence of extreme events on the nodes of a network using a generalized random walk model. The result reveals that the nodes with a larger value of generalized strength, on average, display lower probability for the occurrence of extreme events compared to the nodes with lower values of generalized strength.
The Universe Going Green: Extraordinarily Strong [OIII]5007 in Typical Dwarf Galaxies at z~3

NASA Astrophysics Data System (ADS)

Malkan, Matthew Arnold; Cohen, Daniel

2017-01-01

We constructed the average SEDs of U-dropout galaxies in the Subaru Deep Field. This sample contains more than 5000 Lyman-break galaxies at z~3. Their average near- and mid-IR colors were obtained by stacking JHK and IRAC imaging, in bins of stellar mass. At the lowest mass bins an increasingly strong excess flux is seen in the K filter. This excess can reach 1 magnitude in the broadband filter, and we attribute it to strong \\OIII $\\lambda{5007}$ line emission. The equivalent width is extraordinarily high, reaching almost 1000\\Ang\\ for the average z=3 galaxy at an i magnitude of 27. Such extreme [OIII] emission is very rare in the current epoch, only seen in a handful of metal-deficient dwarf starbursts sometimes referred to as ''Green Peas". In contrast, extreme [OIII]--strong enough to dominate the entire broad-band SED--was evidently the norm for faint galaxies at high redshift. We present evidence that these small but numerous galaxies were primarily responsible for the reionization of the Universe.
(GaIn)(NAs) growth using di-tertiary-butyl-arsano-amine (DTBAA)

NASA Astrophysics Data System (ADS)

Sterzer, E.; Ringler, B.; Nattermann, L.; Beyer, A.; von Hänisch, C.; Stolz, W.; Volz, K.

2017-06-01

III/V semiconductors containing small amounts of Nitrogen (N) are very interesting for a variety of optoelectronic applications. Unfortunately, the conventionally used N precursor 1,1-dimethylhydrazine (UDMHy) has an extremely low N incorporation efficiency in GaAs when grown using metal organic vapor phase epitaxy. Alloying Ga(NAs) with Indium (In) even leads to an exponential reduction of N incorporation. The huge amount of UDMHy in turn changes drastically the growth conditions. Furthermore, the application of this material is still hampered by the large carbon incorporation, most probably originating from the metal organic precursors. Hence, novel precursors for dilute nitride growth are needed. This paper will show (GaIn)(NAs) growth studies with the novel precursor di-tertiary-butyl-arsano-amine in combination with tri-ethyl-gallium and tri-methyl-indium. We show an extremely high N incorporation efficiency in the In containing (GaIn)(NAs). The (GaIn)(NAs) samples investigated in this study have been examined using high resolution X-Ray diffraction, room temperature photoluminescence and atomic force microscope measurements as well as secondary ion mass spectrometry.
Thermoelectric Properties of Nanograined Si-Ge-Au Thin Films Grown by Molecular Beam Deposition

NASA Astrophysics Data System (ADS)

Nishino, Shunsuke; Ekino, Satoshi; Inukai, Manabu; Omprakash, Muthusamy; Adachi, Masahiro; Kiyama, Makoto; Yamamoto, Yoshiyuki; Takeuchi, Tsunehiro

2018-06-01

Conditions to achieve extremely large Seebeck coefficient and extremely small thermal conductivity in Si-Ge-Au thin films formed of nanosized grains precipitated in amorphous matrix have been investigated. We employed molecular beam deposition to prepare Si1- x Ge x Au y thin films on sapphire substrate. The deposited films were annealed under nitrogen gas atmosphere at 300°C to 500°C for 15 min to 30 min. Nanocrystals dispersed in amorphous matrix were clearly observed by transmission electron microscopy. We did not observe anomalously large Seebeck coefficient, but very low thermal conductivity of nearly 1.0 W K-1 m-1 was found at around 0.2 < x < 0.6. The compositional dependence of the thermal conductivity was well accounted for by the compositional dependence of the mixing entropy. Some of these values agree exactly with the amorphous limit predicted by theoretical calculations. The smallest lattice thermal conductivity found for the present samples is lower than that of nanostructured Si-Ge bulk material for which dimensionless figure of merit of ZT ≈ 1 was reported at high temperature.
High-resolution, high-throughput imaging with a multibeam scanning electron microscope

PubMed Central

EBERLE, AL; MIKULA, S; SCHALEK, R; LICHTMAN, J; TATE, ML KNOTHE; ZEIDLER, D

2015-01-01

Electron–electron interactions and detector bandwidth limit the maximal imaging speed of single-beam scanning electron microscopes. We use multiple electron beams in a single column and detect secondary electrons in parallel to increase the imaging speed by close to two orders of magnitude and demonstrate imaging for a variety of samples ranging from biological brain tissue to semiconductor wafers. Lay Description The composition of our world and our bodies on the very small scale has always fascinated people, making them search for ways to make this visible to the human eye. Where light microscopes reach their resolution limit at a certain magnification, electron microscopes can go beyond. But their capability of visualizing extremely small features comes at the cost of a very small field of view. Some of the questions researchers seek to answer today deal with the ultrafine structure of brains, bones or computer chips. Capturing these objects with electron microscopes takes a lot of time – maybe even exceeding the time span of a human being – or new tools that do the job much faster. A new type of scanning electron microscope scans with 61 electron beams in parallel, acquiring 61 adjacent images of the sample at the same time a conventional scanning electron microscope captures one of these images. In principle, the multibeam scanning electron microscope’s field of view is 61 times larger and therefore coverage of the sample surface can be accomplished in less time. This enables researchers to think about large-scale projects, for example in the rather new field of connectomics. A very good introduction to imaging a brain at nanometre resolution can be found within course material from Harvard University on http://www.mcb80x.org/# as featured media entitled ‘connectomics’. PMID:25627873
Brief Report: A mass spectrometry assay to simultaneously analyze ROS1 and RET fusion gene expression in non-small cell lung cancer

PubMed Central

Wijesinghe, Priyanga; Bepler, Gerold

2014-01-01

Introduction ROS1 and RET gene fusions were recently discovered in non-small cell lung cancer (NSCLC) as potential therapeutic targets with small molecule kinase inhibitors. The conventional screening methods of these fusions are time consuming and require samples of high quality and quantity. Here, we describe a novel and efficient method by coupling the power of multiplexing PCR and the sensitivity of mass spectrometry. Methods The multiplex mass spectrometry platform simultaneously tests samples for the expression of nine ROS1 and six RET fusion genes. The assay incorporates detection of wild-type exon junctions immediately upstream and downstream of the fusion junction to exclude false negative results. To flag false positives, the system also comprises two independent assays for each fusion gene junction. Results The characteristic mass spectrometric peaks of the gene fusions were obtained using engineered plasmid constructs. Specific assays targeting the wild-type gene exon junctions were validated using cDNA from lung tissue of healthy individuals. The system was further validated using cDNA derived from NSCLC cell lines that express endogenous fusion genes. The expressed ROS1-SLC34A2 and CCDC6-RET gene fusions from the NSCLC cell lines HCC78 and LC-2/ad, respectively, were accurately detected by the novel assay. The assay is extremely sensitive, capable of detecting an event in test specimens containing 0.5% positive tumors. Conclusion The novel multiplexed assay is robustly capable of detecting 15 different clinically relevant RET and ROS1 fusion variants. The benefits of this detection method include exceptionally low sample input, high cost efficiency, flexibility, and rapid turnover. PMID:25384172
A Stimulated Raman Scattering CMOS Pixel Using a High-Speed Charge Modulator and Lock-in Amplifier.

PubMed

Lioe, De Xing; Mars, Kamel; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Yamada, Takahiro; Hashimoto, Mamoru

2016-04-13

A complementary metal-oxide semiconductor (CMOS) lock-in pixel to observe stimulated Raman scattering (SRS) using a high speed lateral electric field modulator (LEFM) for photo-generated charges and in-pixel readout circuits is presented. An effective SRS signal generated after the SRS process is very small and needs to be extracted from an extremely large offset due to a probing laser signal. In order to suppress the offset components while amplifying high-frequency modulated small SRS signal components, the lock-in pixel uses a high-speed LEFM for demodulating the SRS signal, resistor-capacitor low-pass filter (RC-LPF) and switched-capacitor (SC) integrator with a fully CMOS differential amplifier. AC (modulated) components remained in the RC-LPF outputs are eliminated by the phase-adjusted sampling with the SC integrator and the demodulated DC (unmodulated) components due to the SRS signal are integrated over many samples in the SC integrator. In order to suppress further the residual offset and the low frequency noise (1/f noise) components, a double modulation technique is introduced in the SRS signal measurements, where the phase of high-frequency modulated laser beam before irradiation of a specimen is modulated at an intermediate frequency and the demodulation is done at the lock-in pixel output. A prototype chip for characterizing the SRS lock-in pixel is implemented and a successful operation is demonstrated. The reduction effects of residual offset and 1/f noise components are confirmed by the measurements. A ratio of the detected small SRS to offset a signal of less than 10(-)⁵ is experimentally demonstrated, and the SRS spectrum of a Benzonitrile sample is successfully observed.
Trajectories of psychopathology in extremely low birth weight survivors from early adolescence to adulthood: a 20-year longitudinal study.

PubMed

Van Lieshout, Ryan J; Ferro, Mark A; Schmidt, Louis A; Boyle, Michael H; Saigal, Saroj; Morrison, Katherine M; Mathewson, Karen J

2018-04-18

Individuals born extremely preterm are exposed to significant perinatal stresses that are associated with an increased risk of psychopathology. However, a paucity of longitudinal studies has prevented the empirical examination of long-term, dynamic effects of perinatal adversity on mental health. Here, internalizing and externalizing problems from adolescence through adulthood were compared in individuals born at extremely low birth weight (ELBW; <1,000 g) and normal birth weight (NBW; >2,500 g). Internalizing and externalizing data were collected over 20 years in three waves, during adolescence, young adulthood, and adulthood. Growth models were used to compare longitudinal trajectories in a geographically based sample of 151 ELBW survivors and 137 NBW control participants born between 1977 and 1982 matched for age, sex, and socioeconomic status at age 8. After adjusting for sex, socioeconomic and immigrant status, and family functioning, ELBW survivors failed to show the normative, age-related decline in internalizing problems over time relative to their NBW peers (β = .21; p < .01). Both groups exhibited small declines in externalizing problems over the same period. Self-esteem (but not physical health, IQ, or maternal mood) partially mediated the association between ELBW status and internalizing problems. Extremely low birth weight survivors experienced a blunting of the expected improvement in depression and anxiety from adolescence to adulthood. These findings suggest that altered physiological regulatory systems supporting emotional and cognitive processing may contribute to the maintenance of internalizing problems in this population. © 2018 Association for Child and Adolescent Mental Health.
So Small, So Loud: Extremely High Sound Pressure Level from a Pygmy Aquatic Insect (Corixidae, Micronectinae)

PubMed Central

Sueur, Jérôme; Mackie, David; Windmill, James F. C.

2011-01-01

To communicate at long range, animals have to produce intense but intelligible signals. This task might be difficult to achieve due to mechanical constraints, in particular relating to body size. Whilst the acoustic behaviour of large marine and terrestrial animals has been thoroughly studied, very little is known about the sound produced by small arthropods living in freshwater habitats. Here we analyse for the first time the calling song produced by the male of a small insect, the water boatman Micronecta scholtzi. The song is made of three distinct parts differing in their temporal and amplitude parameters, but not in their frequency content. Sound is produced at 78.9 (63.6–82.2) SPL rms re 2.10−5 Pa with a peak at 99.2 (85.7–104.6) SPL re 2.10−5 Pa estimated at a distance of one metre. This energy output is significant considering the small size of the insect. When scaled to body length and compared to 227 other acoustic species, the acoustic energy produced by M. scholtzi appears as an extreme value, outperforming marine and terrestrial mammal vocalisations. Such an extreme display may be interpreted as an exaggerated secondary sexual trait resulting from a runaway sexual selection without predation pressure. PMID:21698252
So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae).

PubMed

Sueur, Jérôme; Mackie, David; Windmill, James F C

2011-01-01

To communicate at long range, animals have to produce intense but intelligible signals. This task might be difficult to achieve due to mechanical constraints, in particular relating to body size. Whilst the acoustic behaviour of large marine and terrestrial animals has been thoroughly studied, very little is known about the sound produced by small arthropods living in freshwater habitats. Here we analyse for the first time the calling song produced by the male of a small insect, the water boatman Micronecta scholtzi. The song is made of three distinct parts differing in their temporal and amplitude parameters, but not in their frequency content. Sound is produced at 78.9 (63.6-82.2) SPL rms re 2.10(-5) Pa with a peak at 99.2 (85.7-104.6) SPL re 2.10(-5) Pa estimated at a distance of one metre. This energy output is significant considering the small size of the insect. When scaled to body length and compared to 227 other acoustic species, the acoustic energy produced by M. scholtzi appears as an extreme value, outperforming marine and terrestrial mammal vocalisations. Such an extreme display may be interpreted as an exaggerated secondary sexual trait resulting from a runaway sexual selection without predation pressure.
Environmental chemical data for perishable sediments and soils collected in New Orleans, Louisiana, and along the Louisiana Delta following Hurricanes Katrina and Rita, 2005

USGS Publications Warehouse

Witt, Emitt C.; Shi, Honglan; Karstensen, Krista A.; Wang, Jianmin; Adams, Craig D.

2008-01-01

In October 2005, nearly one month after Hurricanes Katrina and Rita, a team of scientists from the U.S. Geological Survey and the Missouri University of Science and Technology deployed to southern Louisiana to collect perishable environmental data resulting from the impacts of these storms. Perishable samples collected for this investigation are subject to destruction or ruin by removal, mixing, or natural decay; therefore, collection is time-critical following the depositional event. A total of 238 samples of sediment, soil, and vegetation were collected to characterize chemical quality. For this analysis, 157 of the 238 samples were used to characterize trace element, iron, total organic carbon, pesticide, and polychlorinated biphenyl concentrations of deposited sediment and associated shallow soils. In decreasing order, the largest variability in trace element concentration was detected for lead, vanadium, chromium, copper, arsenic, cadmium, and mercury. Lead was determined to be the trace element of most concern because of the large concentrations present in the samples ranging from 4.50 to 551 milligrams per kilogram (mg/kg). Sequential extraction analysis of lead indicate that 39.1 percent of the total lead concentration in post-hurricane sediment is associated with the iron-manganese oxide fraction. This fraction is considered extremely mobile under reducing environmental conditions, thereby making lead a potential health hazard. The presence of lead in post-hurricane sediments likely is from redistribution of pre-hurricane contaminated soils and sediments from Lake Pontchartrain and the flood control canals of New Orleans. Arsenic concentrations ranged from 0.84 to 49.1 mg/kg. Although Arsenic concentrations generally were small and consistent with other research results, all samples exceeded the U.S. Environmental Protection Agency’s Human Health Medium-Specific Screening Level of 0.39 mg/kg. Mercury concentrations ranged from 0.02 to 1.30 mg/kg. Comparing the mean mercury concentration present in post-hurricane samples with regional background data from the U.S. Geological Survey National Geochemical Dataset, indicates that mercury concentrations in post-hurricane sediment generally are larger. Sequential extraction analysis of 51 samples for arsenic indicate that 54.5 percent of the total arsenic concentration is contained in the extremely mobile iron-manganese oxide fraction. Pesticide and polychlorinated biphenyl Arochlor concentrations in post-hurricane samples were small. Prometon was the most frequently detected pesticide with concentrations ranging from 2.4 to 193 micrograms per kilogram (µg/kg). Methoxychlor was present in 22 samples with a concentration ranging from 3.5 to 3,510 µg/kg. Although methoxychlor had the largest detected pesticide concentration, it was well below the U.S. Environmental Protection Agency’s High-Priority Screening Level for residential soils. Arochlor congeners were not detected for any sample above the minimum detection level of 7.9 µg/kg.
An Investigation of Bilateral Symmetry During Manual Wheelchair Propulsion.

PubMed

Soltau, Shelby L; Slowik, Jonathan S; Requejo, Philip S; Mulroy, Sara J; Neptune, Richard R

2015-01-01

Studies of manual wheelchair propulsion often assume bilateral symmetry to simplify data collection, processing, and analysis. However, the validity of this assumption is unclear. Most investigations of wheelchair propulsion symmetry have been limited by a relatively small sample size and a focus on a single propulsion condition (e.g., level propulsion at self-selected speed). The purpose of this study was to evaluate bilateral symmetry during manual wheelchair propulsion in a large group of subjects across different propulsion conditions. Three-dimensional kinematics and handrim kinetics along with spatiotemporal variables were collected and processed from 80 subjects with paraplegia while propelling their wheelchairs on a stationary ergometer during three different conditions: level propulsion at their self-selected speed (free), level propulsion at their fastest comfortable speed (fast), and propulsion on an 8% grade at their level, self-selected speed (graded). All kinematic variables had significant side-to-side differences, primarily in the graded condition. Push angle was the only spatiotemporal variable with a significant side-to-side difference, and only during the graded condition. No kinetic variables had significant side-to-side differences. The magnitudes of the kinematic differences were low, with only one difference exceeding 5°. With differences of such small magnitude, the bilateral symmetry assumption appears to be reasonable during manual wheelchair propulsion in subjects without significant upper-extremity pain or impairment. However, larger asymmetries may exist in individuals with secondary injuries and pain in their upper extremity and different etiologies of their neurological impairment.
An Investigation of Bilateral Symmetry During Manual Wheelchair Propulsion

PubMed Central

Soltau, Shelby L.; Slowik, Jonathan S.; Requejo, Philip S.; Mulroy, Sara J.; Neptune, Richard R.

2015-01-01

Studies of manual wheelchair propulsion often assume bilateral symmetry to simplify data collection, processing, and analysis. However, the validity of this assumption is unclear. Most investigations of wheelchair propulsion symmetry have been limited by a relatively small sample size and a focus on a single propulsion condition (e.g., level propulsion at self-selected speed). The purpose of this study was to evaluate bilateral symmetry during manual wheelchair propulsion in a large group of subjects across different propulsion conditions. Three-dimensional kinematics and handrim kinetics along with spatiotemporal variables were collected and processed from 80 subjects with paraplegia while propelling their wheelchairs on a stationary ergometer during three different conditions: level propulsion at their self-selected speed (free), level propulsion at their fastest comfortable speed (fast), and propulsion on an 8% grade at their level, self-selected speed (graded). All kinematic variables had significant side-to-side differences, primarily in the graded condition. Push angle was the only spatiotemporal variable with a significant side-to-side difference, and only during the graded condition. No kinetic variables had significant side-to-side differences. The magnitudes of the kinematic differences were low, with only one difference exceeding 5°. With differences of such small magnitude, the bilateral symmetry assumption appears to be reasonable during manual wheelchair propulsion in subjects without significant upper-extremity pain or impairment. However, larger asymmetries may exist in individuals with secondary injuries and pain in their upper extremity and different etiologies of their neurological impairment. PMID:26125019
Evidence for multidecadal variability in US extreme sea level records

NASA Astrophysics Data System (ADS)

Wahl, Thomas; Chambers, Don P.

2015-03-01

We analyze a set of 20 tide gauge records covering the contiguous United States (US) coastline and the period from 1929 to 2013 to identify long-term trends and multidecadal variations in extreme sea levels (ESLs) relative to changes in mean sea level (MSL). Different data sampling and analysis techniques are applied to test the robustness of the results against the selected methodology. Significant but small long-term trends in ESLs above/below MSL are found at individual sites along most coastline stretches, but are mostly confined to the southeast coast and the winter season when storm surges are primarily driven by extratropical cyclones. We identify six regions with broadly coherent and considerable multidecadal ESL variations unrelated to MSL changes. Using a quasi-nonstationary extreme value analysis, we show that the latter would have caused variations in design relevant return water levels (50-200 year return periods) ranging from ˜10 cm to as much as 110 cm across the six regions. The results raise questions as to the applicability of the "MSL offset method," assuming that ESL changes are primarily driven by changes in MSL without allowing for distinct long-term trends or low-frequency variations. Identifying the coherent multidecadal ESL variability is crucial in order to understand the physical driving factors. Ultimately, this information must be included into coastal design and adaptation processes.
Development of synchrotron X-ray micro-tomography under extreme conditions of pressure and temperature.

PubMed

Álvarez-Murga, M; Perrillat, J P; Le Godec, Y; Bergame, F; Philippe, J; King, A; Guignot, N; Mezouar, M; Hodeau, J L

2017-01-01

X-ray tomography is a non-destructive three-dimensional imaging/microanalysis technique selective to a wide range of properties such as density, chemical composition, chemical states and crystallographic structure with extremely high sensitivity and spatial resolution. Here the development of in situ high-pressure high-temperature micro-tomography using a rotating module for the Paris-Edinburgh cell combined with synchrotron radiation is described. By rotating the sample chamber by 360°, the limited angular aperture of ordinary high-pressure cells is surmounted. Such a non-destructive high-resolution probe provides three-dimensional insight on the morphological and structural evolution of crystalline as well as amorphous phases during high pressure and temperature treatment. To demonstrate the potentials of this new experimental technique the compression behavior of a basalt glass is investigated by X-ray absorption tomography, and diffraction/scattering tomography imaging of the structural changes during the polymerization of C 60 molecules under pressure is performed. Small size and weight of the loading frame and rotating module means that this apparatus is portable, and can be readily installed on most synchrotron facilities to take advantage of the diversity of three-dimensional imaging techniques available at beamlines. This experimental breakthrough should open new ways for in situ imaging of materials under extreme pressure-temperature-stress conditions, impacting diverse areas in physics, chemistry, geology or materials sciences.

Transport Functions Dominate the SAR11 Metaproteome at Low-Nutrient Extremes in the Sargasso Sea

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

Sowell, Sarah M.; Wilhelm, Larry; Norbeck, Angela D.

2009-01-01

The northwestern Sargasso Sea is part of the North Atlantic subtropical oceanic gyre that is characterized as seasonally oligotrophic with pronounced stratification in the summer and autumn. Essentially a marine desert, the biological productivity of this region is reduced during stratified periods as a result of low concentrations of phosphorous and nitrogen in the euphotic zone. To better understand the mechanisms of microbial survival in this oligotrophic environment, we used capillary LC-tandem mass spectrometry to study the composition of microbial proteomes in surface samples collected in September 2005. A total of 2279 peptides that mapped to 236 SAR11 proteins, andmore » 3208 peptides that mapped to 404 Synechococcus proteins, were detected. Mass spectra from SAR11 periplasmic binding proteins accounted for a disproportionately large fraction of the peptides detected, consistent with observations that these extremely small cells devote a large proportion of their volume to periplasm. Abundances were highest for periplasmic substrate-binding proteins for phosphate, amino acids, phosphonate, sugars, and spermidine. Although the data showed that a large fraction of microbial protein synthesis in the Sargasso Sea is devoted to inorganic and organic nutrient acquisition, the proteomes of both SAR11 and Synechococcus also indicated that these populations were actively growing. Our findings support the view that competition for multiple nutrients in oligotrophic systems is extreme but sufficient to sustain microbial community activity.« less
A New Paradigm in Earth Environmental Monitoring with the CYGNSS Small Satellite Constellation

NASA Technical Reports Server (NTRS)

Ruf, C. S.; Chew, C.; Lang, T.; Morris, M. G.; Kyle, K.; Ridley, A.; Balasubramaniam, R.

2018-01-01

A constellation of small, low-cost satellites is able to make scientifically valuable measurements of the Earth which can be used for weather forecasting, disaster monitoring, and climate studies. Eight CYGNSS satellites were launched into low Earth orbit on December 15, 2016. Each satellite carries a science radar receiver which measures GPS signals reflected from the Earth surface. The signals contain information about the surface, including wind speed over ocean and soil moisture and flooding over land. The satellites are distributed around the globe so that measurements can be made more often to capture extreme weather events. Innovative engineering approaches are used to reduce per satellite cost, increase the number in the constellation, and improve temporal sampling. These include the use of differential drag rather than propulsion to adjust the spacing between satellites and the use of existing GPS signals as the science radars’ transmitter. Initial on-orbit results demonstrate the scientific utility of the CYGNSS observations, and suggest that a new paradigm in spaceborne Earth environmental monitoring is possible.
Fully-reversible optical sensor for hydrogen peroxide with fast response.

PubMed

Ding, Longjiang; Chen, Siyu; Zhang, Wei; Zhang, Yinglu; Wang, Xu-Dong

2018-05-09

A fully reversible optical sensor for hydrogen peroxide with fast response is presented. The sensor was fabricated by in-situ growing ultra-small platinum nanoparticles (PtNPs) inside the pores of fibrous silica particles (KCC-1). The nanocomposite was then embedded into a hydrogel matrix and form a sensor layer, the immobilized PtNPs can catalytically convert hydrogen peroxide into molecular oxygen, which is measured via luminescent quenching based oxygen sensor underneath. Owing to the high porosity and permeability of KCC-1 and high local concentration of PtNPs, the sensor exhibits fast response (less than 1 min) and full reversibility. The measurement range of the sensor covers 1.0 μM to 10.0 mM, and very small amount of sample is required during measurement (200 μL). Because of its high stability, excellent reversibility and selectivity, and extremely fast response, the sensor could fulfill all industry requirements for real-time measurement, and fill market vacancy.
Directed transport by surface chemical potential gradients for enhancing analyte collection in nanoscale sensors.

PubMed

Sitt, Amit; Hess, Henry

2015-05-13

Nanoscale detectors hold great promise for single molecule detection and the analysis of small volumes of dilute samples. However, the probability of an analyte reaching the nanosensor in a dilute solution is extremely low due to the sensor's small size. Here, we examine the use of a chemical potential gradient along a surface to accelerate analyte capture by nanoscale sensors. Utilizing a simple model for transport induced by surface binding energy gradients, we study the effect of the gradient on the efficiency of collecting nanoparticles and single and double stranded DNA. The results indicate that chemical potential gradients along a surface can lead to an acceleration of analyte capture by several orders of magnitude compared to direct collection from the solution. The improvement in collection is limited to a relatively narrow window of gradient slopes, and its extent strongly depends on the size of the gradient patch. Our model allows the optimization of gradient layouts and sheds light on the fundamental characteristics of chemical potential gradient induced transport.
Quantum dynamics simulations in an ultraslow bath using hierarchy of stochastic Schrödinger equations

NASA Astrophysics Data System (ADS)

Ke, Yaling; Zhao, Yi

2018-04-01

The hierarchy of stochastic Schrödinger equation, previously developed under the unpolarised initial bath states, is extended in this paper for open quantum dynamics under polarised initial bath conditions. The method is proved to be a powerful tool in investigating quantum dynamics exposed to an ultraslow Ohmic bath, as in this case the hierarchical truncation level and the random sampling number can be kept at a relatively small extent. By systematically increasing the system-bath coupling strength, the symmetric Ohmic spin-boson dynamics is investigated at finite temperature, with a very small cut-off frequency. It is confirmed that the slow bath makes the system dynamics extremely sensitive to the initial bath conditions. The localisation tendency is stronger in the polarised initial bath conditions. Besides, the oscillatory coherent dynamics persists even when the system-bath coupling is very strong, in correspondence with what is found recently in the deep sub-Ohmic bath, where also the low-frequency modes dominate.
On the identification of Dragon Kings among extreme-valued outliers

NASA Astrophysics Data System (ADS)

Riva, M.; Neuman, S. P.; Guadagnini, A.

2013-07-01

Extreme values of earth, environmental, ecological, physical, biological, financial and other variables often form outliers to heavy tails of empirical frequency distributions. Quite commonly such tails are approximated by stretched exponential, log-normal or power functions. Recently there has been an interest in distinguishing between extreme-valued outliers that belong to the parent population of most data in a sample and those that do not. The first type, called Gray Swans by Nassim Nicholas Taleb (often confused in the literature with Taleb's totally unknowable Black Swans), is drawn from a known distribution of the tails which can thus be extrapolated beyond the range of sampled values. However, the magnitudes and/or space-time locations of unsampled Gray Swans cannot be foretold. The second type of extreme-valued outliers, termed Dragon Kings by Didier Sornette, may in his view be sometimes predicted based on how other data in the sample behave. This intriguing prospect has recently motivated some authors to propose statistical tests capable of identifying Dragon Kings in a given random sample. Here we apply three such tests to log air permeability data measured on the faces of a Berea sandstone block and to synthetic data generated in a manner statistically consistent with these measurements. We interpret the measurements to be, and generate synthetic data that are, samples from α-stable sub-Gaussian random fields subordinated to truncated fractional Gaussian noise (tfGn). All these data have frequency distributions characterized by power-law tails with extreme-valued outliers about the tail edges.
Thermoregulatory value of cracking-clay soil shelters for small vertebrates during extreme desert conditions.

PubMed

Waudby, Helen P; Petit, Sophie

2017-05-01

Deserts exhibit extreme climatic conditions. Small desert-dwelling vertebrates have physiological and behavioral adaptations to cope with these conditions, including the ability to seek shelter. We investigated the temperature (T) and relative humidity (RH) regulating properties of the soil cracks that characterize the extensive cracking-clay landscapes of arid Australia, and the extent of their use by 2 small marsupial species: fat-tailed and stripe-faced dunnarts (Sminthopsis crassicaudata and Sminthopsis macroura). We measured hourly (over 24-h periods) the T and RH of randomly-selected soil cracks compared to outside conditions, during 2 summers and 2 winters. We tracked 17 dunnarts (8 Sminthopsis crassicaudata and 9 Sminthopsis macroura) to quantify their use of cracks. Cracks consistently moderated microclimate, providing more stable conditions than available from non-crack points, which often displayed comparatively dramatic fluctuations in T and RH. Both dunnart species used crack shelters extensively. Cracks constitute important shelter for small animals during extreme conditions by providing a stable microclimate, which is typically cooler than outside conditions in summer and warmer in winter. Cracks likely play a fundamental sheltering role by sustaining the physiological needs of small mammal populations. Globally, cracking-clay areas are dominated by agricultural land uses, including livestock grazing. Management of these systems should focus not only on vegetation condition, but also on soil integrity, to maintain shelter resources for ground-dwelling fauna. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.
Intermediate Pond Sizes Contain the Highest Density, Richness, and Diversity of Pond-Breeding Amphibians

PubMed Central

Semlitsch, Raymond D.; Peterman, William E.; Anderson, Thomas L.; Drake, Dana L.; Ousterhout, Brittany H.

2015-01-01

We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes. PMID:25906355
Extreme Vertical Gusts in the Atmospheric Boundary Layer

DTIC Science & Technology

2015-07-01

significant effect on the statistics of the rare, extreme gusts. In the lowest 5,000 ft, boundary layer effects make small to moderate vertical...4 2.4 Effects of Gust Shape ............................................................................................... 5... Definitions Adiabatic Lapse Rate The rate of change of temperature with altitude that would occur if a parcel of air was transported sufficiently
Characterization and prediction of extreme events in turbulence

NASA Astrophysics Data System (ADS)

Fonda, Enrico; Iyer, Kartik P.; Sreenivasan, Katepalli R.

2017-11-01

Extreme events in Nature such as tornadoes, large floods and strong earthquakes are rare but can have devastating consequences. The predictability of these events is very limited at present. Extreme events in turbulence are the very large events in small scales that are intermittent in character. We examine events in energy dissipation rate and enstrophy which are several tens to hundreds to thousands of times the mean value. To this end we use our DNS database of homogeneous and isotropic turbulence with Taylor Reynolds numbers spanning a decade, computed with different small scale resolutions and different box sizes, and study the predictability of these events using machine learning. We start with an aggressive data augmentation to virtually increase the number of these rare events by two orders of magnitude and train a deep convolutional neural network to predict their occurrence in an independent data set. The goal of the work is to explore whether extreme events can be predicted with greater assurance than can be done by conventional methods (e.g., D.A. Donzis & K.R. Sreenivasan, J. Fluid Mech. 647, 13-26, 2010).
Thermal Wadis in Support of Lunar Exploration: Concept Development and Utilization

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

Matyas, Josef; Wegeng, Robert S.; Burgess, Jeremy M.

2009-10-12

Thermal wadis, engineered sources of heat, can be used to extend the life of lunar rovers by keeping them warm during the extreme cold of the lunar night. Thermal wadis can be manufactured by sintering or melting lunar regolith into a solid mass with more than two orders of magnitude higher thermal diffusivities compared to native regolith dust. Small simulant samples were sintered and melted in the electrical furnaces at different temperatures, different heating and cooling rates, various soaking times, under air, or in an argon atmosphere. The samples were analyzed with scanning electron microscopy and energy dispersive spectroscopy, X-raymore » diffraction, a laser-flash thermal diffusivity system, and the millimeter-wave system. The melting temperature of JSC-1AF simulant was ~50°C lower in an Ar atmosphere compared to an air atmosphere. The flow of Ar during sintering and melting resulted in a small mass loss of 0.04 to 0.1 wt% because of the volatization of alkali compounds. In contrast, the samples that were heat-treated under an air atmosphere gained from 0.012 to 0.31 wt% of the total weight. A significantly higher number of cavities were formed inside the samples melted under an argon atmosphere, possibly because of the evolution of oxygen bubbles from iron redox reactions. The calculated emissivity of JSCf-1AF simulant did not change much with temperature, varying between 0.8 and 0.95 at temperatures from 100 to 1200°C. The thermal diffusivities of raw regolith that was compressed under a pressure of 9 metric tons ranged from 0.0013 to 00011 in the 27 to 390°C temperature range. The thermal diffusivities of sintered and melted JSC-1AF simulant varied from 0.0028 to 0.0072 cm2/s with the maximum thermal diffusivities observed in the samples that were heated up 5°C/min from RT to 1150°C under Ar or air. These thermal diffusivities are high enough for the rovers to survive the extreme cold of the Moon at the rim of the Shackleton Crater and allow them to operate for months (or years) as opposed to weeks on the lunar surface. Future investigations will be focused on a system that can efficiently construct a thermal wadi from the lunar mare regolith. Solar heating, microwave heating, or electrical resistance melting are considered.« less
Investigating Astromaterials Curation Applications for Dexterous Robotic Arms

NASA Technical Reports Server (NTRS)

Snead, C. J.; Jang, J. H.; Cowden, T. R.; McCubbin, F. M.

2018-01-01

The Astromaterials Acquisition and Curation office at NASA Johnson Space Center is currently investigating tools and methods that will enable the curation of future astromaterials collections. Size and temperature constraints for astromaterials to be collected by current and future proposed missions will require the development of new robotic sample and tool handling capabilities. NASA Curation has investigated the application of robot arms in the past, and robotic 3-axis micromanipulators are currently in use for small particle curation in the Stardust and Cosmic Dust laboratories. While 3-axis micromanipulators have been extremely successful for activities involving the transfer of isolated particles in the 5-20 micron range (e.g. from microscope slide to epoxy bullet tip, beryllium SEM disk), their limited ranges of motion and lack of yaw, pitch, and roll degrees of freedom restrict their utility in other applications. For instance, curators removing particles from cosmic dust collectors by hand often employ scooping and rotating motions to successfully free trapped particles from the silicone oil coatings. Similar scooping and rotating motions are also employed when isolating a specific particle of interest from an aliquot of crushed meteorite. While cosmic dust curators have been remarkably successful with these kinds of particle manipulations using handheld tools, operator fatigue limits the number of particles that can be removed during a given extraction session. The challenges for curation of small particles will be exacerbated by mission requirements that samples be processed in N2 sample cabinets (i.e. gloveboxes). We have been investigating the use of compact robot arms to facilitate sample handling within gloveboxes. Six-axis robot arms potentially have applications beyond small particle manipulation. For instance, future sample return missions may involve biologically sensitive astromaterials that can be easily compromised by physical interaction with a curator; other potential future returned samples may require cryogenic curation. Robot arms may be combined with high resolution cameras within a sample cabinet and controlled remotely by curator. Sophisticated robot arm and hand combination systems can be programmed to mimic the movements of a curator wearing a data glove; successful implementation of such a system may ultimately allow a curator to virtually operate in a nitrogen, cryogenic, or biologically sensitive environment with dexterity comparable to that of a curator physically handling samples in a glove box.
Impact of the extreme 2009 wildfire Victoria the wettability of naturally highly water repellent soils

NASA Astrophysics Data System (ADS)

Doerr, Stefan H.; Shakesby, Richard A.; Sheridan, Gary J.; Lane, Patrick Nj; Smith, Hugh G.; Bell, Tina; Blake, William H.

2010-05-01

The recent catastrophic wildfires near Melbourne, which peaked on Feb. 7 2009, burned ca 400,000 ha and caused the tragic loss of 173 people. They occurred during unprecedented extreme fire weather where dry northerly winds gusting up to 100 km/h coincided with the highest temperatures ever recorded in this region. These conditions, combined with the very high biomass of mature eucalypt forests, very low fuel moisture conditions and steep slopes, generated extreme burning conditions. A rapid response project was launched under the NERC Urgency Scheme aimed at determining the effects of this extreme event on soil properties. Three replicate sites each were sampled for extremely high burn severity, high burn severity and unburnt control terrain, within mature mixed-species eucalypt forests near Marysville in April 2009. Ash and surface soil (0-2.5 cm and 2.5-5 cm) were collected at 20 sample grid points at each site. Here we report on outcomes from Water Drop Penetration Time (WDPT) tests carried out on soil samples to determine the impact of this extreme event on the wettability of a naturally highly water repellent soil. Field assessment suggested that the impact of this extreme wildfire on the soil was less than might be supposed given the extreme burn severity (indicated by the complete elimination of the ground vegetation). This was confirmed by the laboratory results. No major difference in WDPT was detected between (i) burned and control samples, and (ii) between surface and subsurface WDPT patterns, indicating that soil temperatures in the top 0-2.5 cm did not exceed ~200° C. Seedling germination in burned soil was reduced by at least 2/3 compared to the control samples, however, this reduction is indicative an only modest heat input into the soil. The limited heat input into the soil stands in stark contrast to the extreme burn severity (based on vegetation destruction parameters). We speculate that limited soil heating resulted perhaps from the unusually fast-moving fire front and the resultant short fire residence time during this event. Thick ash layers were present at the time of sampling despite some significant earlier pre-sampling rainfall events. This suggests that the wettable ash (up to 15 cm thick) was able to store substantial amounts of water, which would otherwise have formed overland flow moving over the highly water repellent underlying mineral soil. Once this hydrological ‘sponge' is removed, the lack of ground cover is expected to lead to the underlying soil being susceptible to erosion until the ground cover becomes re-established. This ‘erosion window‘ is likely to be relatively brief over much of the burnt area as the vegetation is already showing a comparatively rapid regrowth response. This is supported by initial results from laboratory germination experiments, which showed seedling emergence from even the most severely burnt sites. The factors contributing to the fire impacts determined here are explored in conjunction with predictions for future burn severity under a changing climate. The soil samples collected represent a reference soil sample collection, which are available to the scientific community for further investigation.
Propulsion engineering study for small-scale Mars missions

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

Whitehead, J.

1995-09-12

Rocket propulsion options for small-scale Mars missions are presented and compared, particularly for the terminal landing maneuver and for sample return. Mars landing has a low propulsive {Delta}v requirement on a {approximately}1-minute time scale, but at a high acceleration. High thrust/weight liquid rocket technologies, or advanced pulse-capable solids, developed during the past decade for missile defense, are therefore more appropriate for small Mars landers than are conventional space propulsion technologies. The advanced liquid systems are characterize by compact lightweight thrusters having high chamber pressures and short lifetimes. Blowdown or regulated pressure-fed operation can satisfy the Mars landing requirement, but hardwaremore » mass can be reduced by using pumps. Aggressive terminal landing propulsion designs can enable post-landing hop maneuvers for some surface mobility. The Mars sample return mission requires a small high performance launcher having either solid motors or miniature pump-fed engines. Terminal propulsion for 100 kg Mars landers is within the realm of flight-proven thruster designs, but custom tankage is desirable. Landers on a 10 kg scale also are feasible, using technology that has been demonstrated but not previously flown in space. The number of sources and the selection of components are extremely limited on this smallest scale, so some customized hardware is required. A key characteristic of kilogram-scale propulsion is that gas jets are much lighter than liquid thrusters for reaction control. The mass and volume of tanks for inert gas can be eliminated by systems which generate gas as needed from a liquid or a solid, but these have virtually no space flight history. Mars return propulsion is a major engineering challenge; earth launch is the only previously-solved propulsion problem requiring similar or greater performance.« less
Extremely preterm infants who are small for gestational age have a high risk of early hypophosphatemia and hypokalemia.

PubMed

Boubred, F; Herlenius, E; Bartocci, M; Jonsson, B; Vanpée, M

2015-11-01

Electrolyte balances have not been sufficiently evaluated in extremely preterm infants after early parenteral nutrition. We investigated the risk of early hypophosphatemia and hypokalemia in extremely preterm infants born small for gestational age (SGA) who received nutrition as currently recommended. This prospective, observational cohort study included all consecutive extremely preterm infants born at 24-27 weeks who received high amino acids and lipid perfusion from birth. We evaluated the electrolyte levels of SGA infants and infants born appropriate for gestational age (AGA) during the first five days of life. The 12 SGA infants had lower plasma potassium levels from Day One compared to the 36 AGA infants and were more likely to have hypokalemia (58% vs 17%, p = 0.001) and hypophosphatemia (40% vs 9%, p < 0.01) during the five-day observation period. After adjusting for perinatal factors, SGA remained significantly associated with hypophosphatemia (odds ratio 1.39, confidence intervals 1.07-1.81, p = 0.01). Extremely preterm infants born SGA who were managed with currently recommended early parenteral nutrition had a high risk of early hypokalemia and hypophosphatemia. Potassium and phosphorus intakes should be set at sufficient levels from birth onwards, especially in SGA infants. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
An Overview of 2014 SBIR Phase I and Phase II Materials Structures for Extreme Environments

NASA Technical Reports Server (NTRS)

Nguyen, Hung D.; Steele, Gynelle C.; Morris, Jessica R.

2015-01-01

NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights nine of the innovative SBIR 2014 Phase I and Phase II projects that emphasize one of NASA Glenn Research Center's six core competencies-Materials and Structures for Extreme Environments. The technologies cover a wide spectrum of applications such as high temperature environmental barrier coating systems, deployable space structures, solid oxide fuel cells, and self-lubricating hard coatings for extreme temperatures. Each featured technology describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.
Mercury and gold concentrations of highly polluted environmental samples determined using prompt gamma-ray analysis and instrument neutron activation analysis

NASA Astrophysics Data System (ADS)

Osawa, Takahito; Hatsukawa, Yuichi; Appel, Peter W. U.; Matsue, Hideaki

2011-04-01

The authors have established a method of determining mercury and gold in severely polluted environmental samples using prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA). Since large amounts of mercury are constantly being released into the environment by small-scale gold mining in many developing countries, the mercury concentration in tailings and water has to be determined to mitigate environmental pollution. Cold-vapor atomic absorption analysis, the most pervasive method of mercury analysis, is not suitable because tailings and water around mining facilities have extremely high mercury concentrations. On the other hand, PGA can determine high mercury concentrations in polluted samples as it has an appropriate level of sensitivity. Moreover, gold concentrations can be determined sequentially by using INAA after PGA. In conclusion, the analytical procedure established in this work using PGA and INAA is the best way to evaluate the degree of pollution and the tailing resource value. This method will significantly contribute to mitigating problems in the global environment.
Two Different Views on the World Around Us: The World of Uniformity versus Diversity

PubMed Central

Nayakankuppam, Dhananjay

2016-01-01

We propose that when individuals believe in fixed traits of personality (entity theorists), they are likely to expect a world of “uniformity.” As such, they easily infer a population statistic from a small sample of data with confidence. In contrast, individuals who believe in malleable traits of personality (incremental theorists) are likely to presume a world of “diversity,” such that they “hesitate” to infer a population statistic from a similarly sized sample. In four laboratory experiments, we found that compared to incremental theorists, entity theorists estimated a population mean from a sample with a greater level of confidence (Studies 1a and 1b), expected more homogeneity among the entities within a population (Study 2), and perceived an extreme value to be more indicative of an outlier (Study 3). These results suggest that individuals are likely to use their implicit self-theory orientations (entity theory versus incremental theory) to see a population in general as a constitution either of homogeneous or heterogeneous entities. PMID:27977788
An automated microfluidic chip system for detection of piscine nodavirus and characterization of its potential carrier in grouper farms.

PubMed

Kuo, Hsiao-Che; Wang, Ting-Yu; Hsu, Hao-Hsuan; Lee, Szu-Hsien; Chen, Young-Mao; Tsai, Tieh-Jung; Ou, Ming-Chang; Ku, Hsiao-Tung; Lee, Gwo-Bin; Chen, Tzong-Yueh

2012-01-01

Groupers of the Epinephelus spp. are an important aquaculture species of high economic value in the Asia Pacific region. They are susceptible to piscine nodavirus infection, which results in viral nervous necrosis disease. In this study, a rapid and sensitive automated microfluidic chip system was implemented for the detection of piscine nodavirus; this technology has the advantage of requiring small amounts of sample and has been developed and applied for managing grouper fish farms. Epidemiological investigations revealed an extremely high detection rate of piscine nodavirus (89% of fish samples) from 5 different locations in southern Taiwan. In addition, positive samples from the feces of fish-feeding birds indicated that the birds could be carrying the virus between fish farms. In the present study, we successfully introduced this advanced technology that combines engineering and biological approaches to aquaculture. In the future, we believe that this approach will improve fish farm management and aid in reducing the economic loss experienced by fish farmers due to widespread disease outbreaks.
Ar-40/Ar-39 Ages of Maskelynite Grains from ALHA 77005

NASA Technical Reports Server (NTRS)

Turrin, B.; Park, J.; Herzog, G. F.; Lindsay, F. N.; Delaney, J. S.; Nyquist, L. E.; Swisher, C., III

2013-01-01

We present Ar-40/Ar-39 measurements for twelve small (20-60 micro-g) maskelynite samples from the heavily shocked martian meteorite ALHA 77005. The reported modal composition for ALHA 77005 is 50-60% olivine (Fa28), 30-40% pyroxene (Wo5Fs23En72), approx.8% maskelynite (An53), and approx.2% opaques by volume [1]). The meteorite is usually classified as a lherzolite. Previous Studies - Ar-40/Ar-39 results from previous work display disturbed release spectra [2,3]. In study [2], Ar-40/Ar-39 measurements on a 52-mg whole-rock sample produced an extremely disturbed release spec-trum, with all calculated apparent ages > 1 Ga, (Fig. 1). In a subsequent study [3], a light and a dark phase were analyzed. A 2.3-mg sample of the light, relatively low-K phase produced a disturbed release spectrum. For the first 20% of the Ar-39(sub K), most of the apparent ages exceeded >1 Ga; the remaining 80% yielded ages between 0.3-0.5 Ga. The integrated age for this phase is 0.9 Ga.

An Automated Microfluidic Chip System for Detection of Piscine Nodavirus and Characterization of Its Potential Carrier in Grouper Farms

PubMed Central

Hsu, Hao-Hsuan; Lee, Szu-Hsien; Chen, Young-Mao; Tsai, Tieh-Jung; Ou, Ming-Chang; Ku, Hsiao-Tung; Lee, Gwo-Bin; Chen, Tzong-Yueh

2012-01-01

Groupers of the Epinephelus spp. are an important aquaculture species of high economic value in the Asia Pacific region. They are susceptible to piscine nodavirus infection, which results in viral nervous necrosis disease. In this study, a rapid and sensitive automated microfluidic chip system was implemented for the detection of piscine nodavirus; this technology has the advantage of requiring small amounts of sample and has been developed and applied for managing grouper fish farms. Epidemiological investigations revealed an extremely high detection rate of piscine nodavirus (89% of fish samples) from 5 different locations in southern Taiwan. In addition, positive samples from the feces of fish-feeding birds indicated that the birds could be carrying the virus between fish farms. In the present study, we successfully introduced this advanced technology that combines engineering and biological approaches to aquaculture. In the future, we believe that this approach will improve fish farm management and aid in reducing the economic loss experienced by fish farmers due to widespread disease outbreaks. PMID:22912690
Effects of habitat fragmentation on wild mammal infection by Trypanosoma cruzi.

PubMed

Vaz, V C; D'Andrea, P S; Jansen, A M

2007-11-01

Expansion of human activities frequently results in habitat fragmentation, a phenomenon that has been widely recognized in the last decades as one of the major threats to world's biodiversity. The transformation of a continuous forest into a fragmented area results in a hyper-dynamic landscape with unpredictable consequences to overall ecosystem health. The effect of the fragmentation process on Trypanosoma cruzi infection among small wild mammals was studied in an Atlantic Rain Forest landscape. Comparing continous forest to fragmented habitat, marsupials were less abundant than rodents in the continuous landscape. An overall decrease in small wild mammal richness was observed in the smaller fragments. An anti-T. cruzi seroprevalence of 18% (82/440) was deteced by immunofluorescence assay. Moreover, this seroprevalence was higher in the fragmented habitat than in the continuous forest. According to the collected data, 3 main factors seem to modulate infection by T. cruzi in small wild mammals: (i) habitat fragmentation; (ii) biodiversity loss; (iii) increase of marsupial abundance in mammal communities. Furthermore, an extremely mild controlled infection by T. cruzi was detected since no patent parasitaemia could be detected in fresh blood samples, and no parasites were isolated by haemoculture.
Size distribution and growth rate of crystal nuclei near critical undercooling in small volumes

NASA Astrophysics Data System (ADS)

Kožíšek, Z.; Demo, P.

2017-11-01

Kinetic equations are numerically solved within standard nucleation model to determine the size distribution of nuclei in small volumes near critical undercooling. Critical undercooling, when first nuclei are detected within the system, depends on the droplet volume. The size distribution of nuclei reaches the stationary value after some time delay and decreases with nucleus size. Only a certain maximum size of nuclei is reached in small volumes near critical undercooling. As a model system, we selected recently studied nucleation in Ni droplet [J. Bokeloh et al., Phys. Rev. Let. 107 (2011) 145701] due to available experimental and simulation data. However, using these data for sample masses from 23 μg up to 63 mg (corresponding to experiments) leads to the size distribution of nuclei, when no critical nuclei in Ni droplet are formed (the number of critical nuclei < 1). If one takes into account the size dependence of the interfacial energy, the size distribution of nuclei increases to reasonable values. In lower volumes (V ≤ 10-9 m3) nucleus size reaches some maximum extreme size, which quickly increases with undercooling. Supercritical clusters continue their growth only if the number of critical nuclei is sufficiently high.
Structural characterization and gas reactions of small metal particles by high-resolution TEM and TED

NASA Technical Reports Server (NTRS)

Heinemann, K.

1985-01-01

The interaction of 100 and 200 keV electron beams with amorphous alumina, titania, and aluminum nitride substrates and nanometer-size palladium particulate deposits was investigated for the two extreme cases of (1) large-area electron-beam flash-heating and (2) small-area high-intensity electron-beam irradiation. The former simulates a short-term heating effect with minimum electron irradiation exposure, the latter simulates high-dosage irradiation with minimum heating effect. All alumina and titania samples responded to the flash-heating treatment with significant recrystallization. However, the size, crystal structure, shape, and orientation of the grains depended on the type and thickness of the films and the thickness of the Pd deposit. High-dosage electron irradiation also readily crystallized the alumina substrate films but did not affect the titania films. The alumina recrystallization products were usually either all in the alpha phase, or they were a mixture of small grains in a number of low-temperature phases including gamma, delta, kappa, beta, theta-alumina. Palladium deposits reacted heavily with the alumina substrates during either treatment, but they were very little effected when supported on titania. Both treatments had the same, less prominent localized crystallization effect on aluminum nitride films.
[Bacteriological quality of air in a ward for sterile pharmaceutical preparations].

PubMed

Caorsi P, Beatriz; Sakurada Z, Andrea; Ulloa F, M Teresa; Pezzani V, Marcela; Latorre O, Paz

2011-02-01

An extremely clean area is required for preparation of sterile pharmaceutical compounds, in compliance with international standards, to minimize the probability of microbial contamination. To evaluate the bacteriological quality of the air in the Sterile Pharmaceutical Preparation Unit of the University of Chile's Clinical Hospital and to set up alerts and action levels of bacterial growth. We studied eight representative sites of our Unit on a daily basis from January to February 2005 and twice a week from June 2005 to February 2006. We collected 839 samples of air by impact in the Petri dish. 474 (56.5%) samples were positive; 17 (3.5%) of them had an inappropriate bacterial growth (2% of total samples). The samples from sites 1 and 2 (big and small biosafety cabinets) were negative. The countertop and transfer area occasionally exceeded the bacterial growth limits. The most frequently isolated bacteria were coagulase-negative staphylococci, Micrococcus spp and Corynebacterium spp, from skin microbiota, and Bacillus spp, an environmental bacteria. From a microbiological perspective, the air quality in our sterile preparation unit complied with international standards. Setting institutional alerts and action levels and appropriately identifying bacteria in sensitive areas permits quantification of the microbial load and application of preventive measures.
Compact turnkey focussing neutron guide system for inelastic scattering investigations

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

Brandl, G., E-mail: g.brandl@fz-juelich.de; Georgii, R.; Dunsiger, S. R.

2015-12-21

We demonstrate the performance of a compact neutron guide module which boosts the intensity in inelastic neutron scattering experiments by approximately a factor of 40. The module consists of two housings containing truly curved elliptic focussing guide elements, positioned before and after the sample. The advantage of the module lies in the ease with which it may be reproducibly mounted on a spectrometer within a few hours, on the same timescale as conventional sample environments. It is particularly well suited for samples with a volume of a few mm{sup 3}, thus enabling the investigation of materials which to date wouldmore » have been considered prohibitively small or samples exposed to extreme environments, where there are space constraints. We benchmark the excellent performance of the module by measurements of the structural and magnetic excitations in single crystals of model systems. In particular, we report the phonon dispersion in the simple element lead. We also determine the magnon dispersion in the spinel ZnCr{sub 2}Se{sub 4} (V = 12.5 mm{sup 3}), where strong magnetic diffuse scattering at low temperatures evolves into distinct helical order.« less
Effect of the electrical currents generated by the intestinal smooth muscle layers on pancreatic enzyme activity: an in vitro study.

PubMed

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

2007-05-01

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

NASA Astrophysics Data System (ADS)

Tobler, Michael; Schlupp, Ingo; García de León, Francisco J.; Glaubrecht, Matthias; Plath, Martin

2007-05-01

Living in extreme habitats typically requires costly adaptations of any organism tolerating these conditions, but very little is known about potential benefits that trade off these costs. We suggest that extreme habitats may function as refuge from parasite infections, since parasites can become locally extinct either directly, through selection by an extreme environmental parameter on free-living parasite stages, or indirectly, through selection on other host species involved in its life cycle. We tested this hypothesis in a small freshwater fish, the Atlantic molly ( Poecilia mexicana) that inhabits normal freshwaters as well as extreme habitats containing high concentrations of toxic hydrogen sulfide. Populations from such extreme habitats are significantly less parasitized by the trematode Uvulifer sp. than a population from a non-sulfidic habitat. We suggest that reduced parasite prevalence may be a benefit of living in sulfidic habitats.
Compression Strength of Sulfur Concrete Subjected to Extreme Cold

NASA Technical Reports Server (NTRS)

Grugel, Richard N.

2008-01-01

Sulfur concrete cubes were cycled between liquid nitrogen and room temperature to simulate extreme exposure conditions. Subsequent compression testing showed the strength of cycled samples to be roughly five times less than those non-cycled. Fracture surface examination showed de-bonding of the sulfur from the aggregate material in the cycled samples but not in those non-cycled. The large discrepancy found, between the samples is attributed to the relative thermal properties of the materials constituting the concrete.
Fourier fringe analysis and its application to metrology of extreme physical phenomena: a review [Invited].

PubMed

Takeda, Mitsuo

2013-01-01

The paper reviews a technique for fringe analysis referred to as Fourier fringe analysis (FFA) or the Fourier transform method, with a particular focus on its application to metrology of extreme physical phenomena. Examples include the measurement of extremely small magnetic fields with subfluxon sensitivity by electron wave interferometry, subnanometer wavefront evaluation of projection optics for extreme UV lithography, the detection of sub-Ångstrom distortion of a crystal lattice, and the measurement of ultrashort optical pulses in the femotsecond to attosecond range, which show how the advantages of FFA are exploited in these cutting edge applications.
Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

NASA Astrophysics Data System (ADS)

Miller, L. A.; Papakyriakou, T. N.

2015-12-01

In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.
Min and Max Exponential Extreme Interval Values and Statistics

ERIC Educational Resources Information Center

Jance, Marsha; Thomopoulos, Nick

2009-01-01

The extreme interval values and statistics (expected value, median, mode, standard deviation, and coefficient of variation) for the smallest (min) and largest (max) values of exponentially distributed variables with parameter ? = 1 are examined for different observation (sample) sizes. An extreme interval value g[subscript a] is defined as a…
High-resolution stochastic generation of extreme rainfall intensity for urban drainage modelling applications

NASA Astrophysics Data System (ADS)

Peleg, Nadav; Blumensaat, Frank; Molnar, Peter; Fatichi, Simone; Burlando, Paolo

2016-04-01

Urban drainage response is highly dependent on the spatial and temporal structure of rainfall. Therefore, measuring and simulating rainfall at a high spatial and temporal resolution is a fundamental step to fully assess urban drainage system reliability and related uncertainties. This is even more relevant when considering extreme rainfall events. However, the current space-time rainfall models have limitations in capturing extreme rainfall intensity statistics for short durations. Here, we use the STREAP (Space-Time Realizations of Areal Precipitation) model, which is a novel stochastic rainfall generator for simulating high-resolution rainfall fields that preserve the spatio-temporal structure of rainfall and its statistical characteristics. The model enables a generation of rain fields at 102 m and minute scales in a fast and computer-efficient way matching the requirements for hydrological analysis of urban drainage systems. The STREAP model was applied successfully in the past to generate high-resolution extreme rainfall intensities over a small domain. A sub-catchment in the city of Luzern (Switzerland) was chosen as a case study to: (i) evaluate the ability of STREAP to disaggregate extreme rainfall intensities for urban drainage applications; (ii) assessing the role of stochastic climate variability of rainfall in flow response and (iii) evaluate the degree of non-linearity between extreme rainfall intensity and system response (i.e. flow) for a small urban catchment. The channel flow at the catchment outlet is simulated by means of a calibrated hydrodynamic sewer model.
Aerosol emissions from forest and grassland burnings in the southern amazon basin and central Brazil

NASA Astrophysics Data System (ADS)

Leslie, Alistair C. D.

1981-03-01

Forest and grassland clearing by means of prescribed fires in tropical areas of the world may be responsible for large inputs of fine particulates to the global atmosphere besides being a major source of trace gases. The major continents on which extensive biomass burning takes place are Africa and South America. Such agricultural practices of burning have been employed throughout man's existence, but the importance and significance of such burning relative to anthropogenic industrial emissions to the atmosphere has not until extremely recently been seriously studied. In August-September 1979 project "Brushfire 1979" took place based in Brasília, Brazil. The Air Quality Division of the National Center for Atmospheric Research made ground level and aircraft measurements of trace gases (e.g. CO 2, CO, CH 4, N 2O, H 2, CH 3Cl, COS, NO, NO 2, O 3) and Florida State University sampled ground level aerosol emissions from grass and forest burnings. Aerosols were sampled using plastic 7-stage single orifice cascade impactors and FSU type linear and circular "streakers". Long term sampling was made of regional background for total particulates (<15 μmad) with 2 h resolution using streakers and with impactors for 24 h resolution of 7 particle size fractions (<0.25 to >8 μmad). Short term sampling within grass or forest fires was made using impactors incorporated into portable kits containing 4 miniature 12-18 V dc Brailsford pumps and a disposable dry cell power pack. Sampling times of 5-15 min were found optimal under these conditions. Grass fires were sampled in the savannah area northeast of Brasília and forest fires in the state of Mato Grosso on the southern edge of the dryland forest of the Amazon basin. Residual ash samples were collected. All of the samples were analyzed at Florida State University using PIXE for 15-20 elements including Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb and Sr. Computer reduction of the X-ray spectra was made using the "HEXB" program. One of the prominent features found was the large flux of small particles (<2.0 μm) from both fire types. P, S and Cl were mostly small particle, Mg, Al, Si and K showed a bimodal distribution biased towards the small particle range, while Ca, Ti and Fe (crustal elements) predominated in the large particle mode. As Cl was found to be exclusively small particle, a formation mechanism in which HCl gas neutralizes small organic particles containing P and S may be hypothesized. A much more extensive field program for the summer of 1980 is planned to take place in the central Amazon basin using ground and airborne aerosol samplers, to capitalize on the work pioneered in this study.
Estimation of breeding values using selected pedigree records.

PubMed

Morton, Richard; Howarth, Jordan M

2005-06-01

Fish bred in tanks or ponds cannot be easily tagged individually. The parentage of any individual may be determined by DNA fingerprinting, but is sufficiently expensive that large numbers cannot be so finger-printed. The measurement of the objective trait can be made on a much larger sample relatively cheaply. This article deals with experimental designs for selecting individuals to be finger-printed and for the estimation of the individual and family breeding values. The general setup provides estimates for both genetic effects regarded as fixed or random and for fixed effects due to known regressors. The family effects can be well estimated when even very small numbers are finger-printed, provided that they are the individuals with the most extreme phenotypes.
Tapping mode imaging with an interfacial force microscope

NASA Astrophysics Data System (ADS)

Warren, O. L.; Graham, J. F.; Norton, P. R.

1997-11-01

In their present embodiment, sensors used in interfacial force microscopy do not have the necessary mechanical bandwidth to be employed as free-running tapping mode devices. We describe an extremely stable method of obtaining tapping mode images using feedback on the sensor. Our method is immune to small dc drifts in the force signal, and the prospect of diminishing the risk of damaging fragile samples is realized. The feasibility of the technique is demonstrated by our imaging work on a Kevlar fiber-epoxy composite. We also present a model which accounts for the frequency dependence of the sensor in air when operating under closed loop control. A simplified force modulation model is investigated to explore the effect of contact on the closed loop response of the sensor.
Environment Monitor

NASA Technical Reports Server (NTRS)

1988-01-01

Viking landers touched down on Mars equipped with a variety of systems to conduct automated research, each carrying a compact but highly sophisticated instrument for analyzing Martian soil and atmosphere. Instrument called a Gas Chromatography/Mass Spectrometer (GC/MS) had to be small, lightweight, shock resistant, highly automated and extremely sensitive, yet require minimal electrical power. Viking Instruments Corporation commercialized this technology and targeted their primary market as environmental monitoring, especially toxic and hazardous waste site monitoring. Waste sites often contain chemicals in complex mixtures, and the conventional method of site characterization, taking samples on-site and sending them to a laboratory for analysis is time consuming and expensive. Other terrestrial applications are explosive detection in airports, drug detection, industrial air monitoring, medical metabolic monitoring and for military, chemical warfare agents.
Kurtosis as Peakedness, 1905 – 2014. R.I.P.

PubMed Central

WESTFALL, Peter H.

2014-01-01

Summary The incorrect notion that kurtosis somehow measures “peakedness” (flatness, pointiness or modality) of a distribution is remarkably persistent, despite attempts by statisticians to set the record straight. This article puts the notion to rest once and for all. Kurtosis tells you virtually nothing about the shape of the peak - its only unambiguous interpretation is in terms of tail extremity; i.e., either existing outliers (for the sample kurtosis) or propensity to produce outliers (for the kurtosis of a probability distribution). To clarify this point, relevant literature is reviewed, counterexample distributions are given, and it is shown that the proportion of the kurtosis that is determined by the central μ ± σ range is usually quite small. PMID:25678714
Does Life Seem Better on a Sunny Day? Examining the Association between Daily Weather Conditions and Life Satisfaction Judgments

PubMed Central

Lucas, Richard E.; Lawless, Nicole M.

2013-01-01

Weather conditions have been shown to affect a broad range of thoughts, feelings, and behaviors. The current study examines whether these effects extend to life satisfaction judgments. We examine the association between daily weather conditions and life satisfaction in a representative sample of over 1 million Americans from all 50 states who were assessed (in a cross-sectional design) over a 5-year period. Most daily weather conditions were unrelated to life satisfaction judgments, and those effects that were significant reflect very small effects that were only detectable because of the extremely high power of these analyses. These results show that weather does not reliably affect judgments of life satisfaction. PMID:23607534
EIT and the Popular Imagination

NASA Technical Reports Server (NTRS)

Gurman, J. B.

2005-01-01

The Extreme ultraviolet Imaging Telescope on board SOHO, designed and built by Principal Investigator Jean-Pierre Delaboudiniere and his French/Belgan/US team, has produced numerous scientific breakthroughs, and has become both the standard coronal finder telescope and the determinant of whether halo coronal mass ejections are earthward-directed. Due to the dramatic nature of the images produced by EIT over the last nearly ten years, those images have been adopted worldwide in a manner no one could have foreseen before the launch of SOHO. I examine a small sample of the many scientific, commercial, and cultural uses of EIT imagery from the last decade in order to demonstrate how well-visualized, scientific imagery can first penetrate and then become an accepted part of the popular imagination.

The Extreme Ultraviolet Flux of Very Low Mass Stars

NASA Astrophysics Data System (ADS)

Drake, Jeremy

2017-09-01

The X-ray and EUV emission of stars is vital for understanding the atmospheres and evolution of their planets. The coronae of dwarf stars later than M6 behave differently to those of earlier spectral types and are more X-ray dim and radio bright. Too faint to have been observed by EUVE, their EUV behavior is currently highly uncertain. We propose to observe a small sample of late M dwarfs using the off-axis HRC-S thin Al" filter that is sensitive to EUV emission in the 50-200 A range. The measured fluxes will be used to understand the amount of cooler coronal plasma present, and extend X-ray-EUV flux relations to the latest stellar types.
The multi-purpose three-axis spectrometer (TAS) MIRA at FRM II

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

Georgii, Robert; Weber, Tobias; Brandl, Georg

The cold-neutron three-axis spectrometer MIRA is an instrument optimized for low-energy excitations. Its excellent intrinsic $Q$-resolution makes it ideal for studying incommensurate magnetic systems (elastic and inelastic). MIRA is at the forefront of using advanced neutron focusing optics such as elliptic guides, which enable the investigation of small samples under extreme conditions. Another advantage of MIRA is the modular assembly allowing for instrumental adaption to the needs of the experiment within a few hours. The development of new methods such as the spin-echo technique MIEZE is another important application at MIRA. Finally, scientific topics include the investigation of complex inter-metallicmore » alloys and spectroscopy on incommensurate magnetic structures.« less
Steady inviscid transonic flows over planar airfoils: A search for a simplified procedure

NASA Technical Reports Server (NTRS)

Magnus, R.; Yoshihara, H.

1973-01-01

A finite difference procedure based upon a system of unsteady equations in proper conservation form with either exact or small disturbance steady terms is used to calculate the steady flows over several classes of airfoils. The airfoil condition is fulfilled on a slab whose upstream extremity is a semi-circle overlaying the airfoil leading edge circle. The limitations of the small disturbance equations are demonstrated in an extreme example of a blunt-nosed, aft-cambered airfoil. The necessity of using the equations in proper conservation form to capture the shock properly is stressed. Ability of the steady relaxation procedures to capture the shock is briefly examined.
Survey of human pharmaceuticals in drinking water in the Czech Republic.

PubMed

Kozisek, Frantisek; Pomykacova, Ivana; Jeligova, Hana; Cadek, Vaclav; Svobodova, Veronika

2013-03-01

The first large-scale assessment of pharmaceuticals in drinking water in the Czech Republic (CR) focused on the detection of five substances. Samples were collected from public water systems supplying 5.3 million people, 50.5% of the Czech population. In the initial survey of tap water from 92 major supply zones using mostly surface water, no pharmaceutical exceeded the limit of quantification (LOQ = 0.5 ng/L). In a second survey, samples were collected from the outlet of 23 water treatment plants (WTPs) considered of high risk because they use surface waters influenced by wastewater. Ibuprofen was the most frequently found pharmaceutical (19 samples), followed by carbamazepine (12), naproxen (8), and diclofenac (3); concentrations ranged from 0.5 to 20.7 ng/L, with medians below 6 ng/L. Concentrations of 17α-ethinylestradiol were below the LOQ. A follow-up survey included tap and outlet samples from eight of the 23 WTPs with the highest concentrations. Pharmaceuticals were quantified in only three tap water samples. Regarding risks to consumers, these results suggest that a relatively small population (<10%) in the CR is exposed to quantifiable concentrations of pharmaceuticals in tap water and that an extremely high margin of safety (several thousand-fold to several million-fold) is associated with these exposures.
FastID: Extremely Fast Forensic DNA Comparisons

DTIC Science & Technology

2017-05-19

FastID: Extremely Fast Forensic DNA Comparisons Darrell O. Ricke, PhD Bioengineering Systems & Technologies Massachusetts Institute of...Technology Lincoln Laboratory Lexington, MA USA Darrell.Ricke@ll.mit.edu Abstract—Rapid analysis of DNA forensic samples can have a critical impact on...time sensitive investigations. Analysis of forensic DNA samples by massively parallel sequencing is creating the next gold standard for DNA
Work activities and musculoskeletal complaints among preschool workers.

PubMed

Grant, K A; Habes, D J; Tepper, A L

1995-12-01

The potential for musculoskeletal trauma among preschool workers has been largely unexplored in the United States. This case report describes an investigation conducted to identify and evaluate possible causes of back and lower extremity pain among 22 workers at a Montessori day care facility. Investigators met with and distributed a questionnaire to school employees, and made measurements of workstation and furniture dimensions. Investigators also recorded the normal work activities of school employees on videotape, and performed a work sampling study to estimate the percentage of time employees spend performing various tasks and in certain postures. Questionnaire results from 18 employees indicated that back pain/discomfort was a common musculoskeletal complaint, reported by 61% of respondents. Neck/shoulder pain, lower extremity pain and hand/wrist pain were reported by 33, 33 and 11% of respondents, respectively. Observation and analysis of work activities indicated that employees spend significant periods of time kneeling, sitting on the floor, squatting, or bending at the waist. Furthermore, staff members who work with smaller children (i.e. six weeks to 18 months of age) performed more lifts and assumed more awkward lower extremity postures than employees who work with older children (3-4 years of age). Analysis of two lifting tasks using the revised NIOSH lifting equation indicated that employees who handle small children may be at increased risk of lifting-related low back pain. Investigators concluded that day care employees at this facility are at increased risk of low back pain and lower extremity (i.e. knee) injury due to work activities that require awkward or heavy lifts, and static working postures. Recommendations for reducing or eliminating these risks by modifying the workplace and changing the organization and methods of work are presented.
Ultimately Reliable Pyrotechnic Systems

NASA Technical Reports Server (NTRS)

Scott, John H.; Hinkel, Todd

2015-01-01

This paper presents the methods by which NASA has designed, built, tested, and certified pyrotechnic devices for high reliability operation in extreme environments and illustrates the potential applications in the oil and gas industry. NASA's extremely successful application of pyrotechnics is built upon documented procedures and test methods that have been maintained and developed since the Apollo Program. Standards are managed and rigorously enforced for performance margins, redundancy, lot sampling, and personnel safety. The pyrotechnics utilized in spacecraft include such devices as small initiators and detonators with the power of a shotgun shell, detonating cord systems for explosive energy transfer across many feet, precision linear shaped charges for breaking structural membranes, and booster charges to actuate valves and pistons. NASA's pyrotechnics program is one of the more successful in the history of Human Spaceflight. No pyrotechnic device developed in accordance with NASA's Human Spaceflight standards has ever failed in flight use. NASA's pyrotechnic initiators work reliably in temperatures as low as -420 F. Each of the 135 Space Shuttle flights fired 102 of these initiators, some setting off multiple pyrotechnic devices, with never a failure. The recent landing on Mars of the Opportunity rover fired 174 of NASA's pyrotechnic initiators to complete the famous '7 minutes of terror.' Even after traveling through extreme radiation and thermal environments on the way to Mars, every one of them worked. These initiators have fired on the surface of Titan. NASA's design controls, procedures, and processes produce the most reliable pyrotechnics in the world. Application of pyrotechnics designed and procured in this manner could enable the energy industry's emergency equipment, such as shutoff valves and deep-sea blowout preventers, to be left in place for years in extreme environments and still be relied upon to function when needed, thus greatly enhancing safety and operational availability.
Extreme sensory processing patterns show a complex association with depression, and impulsivity, alexithymia, and hopelessness.

PubMed

Serafini, Gianluca; Gonda, Xenia; Canepa, Giovanna; Pompili, Maurizio; Rihmer, Zoltan; Amore, Mario; Engel-Yeger, Batya

2017-03-01

The involvement of extreme sensory processing patterns, impulsivity, alexithymia, and hopelessness was hypothesized to contribute to the complex pathophysiology of major depression and bipolar disorder. However, the nature of the relation between these variables has not been thoroughly investigated. This study aimed to explore the association between extreme sensory processing patterns, impulsivity, alexithymia, depression, and hopelessness. We recruited 281 euthymic participants (mean age=47.4±12.1) of which 62.3% with unipolar major depression and 37.7% with bipolar disorder. All participants completed the Adolescent/Adult Sensory Profile (AASP), Toronto Alexithymia Scale (TAS-20), second version of the Beck Depression Inventory (BDI-II), Barratt Impulsivity Scale (BIS), and Beck Hopelessness Scale (BHS). Lower registration of sensory input showed a significant correlation with depression, impulsivity, attentional/motor impulsivity, and alexithymia. It was significantly more frequent among participants with elevated hopelessness, and accounted for 22% of the variance in depression severity, 15% in greater impulsivity, 36% in alexithymia, and 3% in hopelessness. Elevated sensory seeking correlated with enhanced motor impulsivity and decreased non-planning impulsivity. Higher sensory sensitivity and sensory avoiding correlated with depression, impulsivity, and alexithymia. The study was limited by the relatively small sample size and cross-sectional nature of the study. Furthermore, only self-report measures that may be potentially biased by social desirability were used. Extreme sensory processing patterns, impulsivity, alexithymia, depression, and hopelessness may show a characteristic pattern in patients with major affective disorders. The careful assessment of sensory profiles may help in developing targeted interventions and improve functional/adaptive strategies. Copyright © 2016 Elsevier B.V. All rights reserved.
Technology perspectives in the future exploration of extreme environments

NASA Astrophysics Data System (ADS)

Cutts, J.; Balint, T.; Kolawa, El.; Peterson, C.

2007-08-01

Solar System exploration is driven by high priority science goals and objectives at diverse destinations, as described in the NRC Decadal Survey and in NASA's 2006 Solar System Exploration (SSE) Roadmap. Proposed missions to these targets encounter extreme environments, including high or low temperatures, high pressure, corrosion, high heat flux, radiation and thermal cycling. These conditions are often coupled, such as low temperature and high radiation at Europa; and high temperature and high pressure near the surface of Venus. Mitigation of these environmental conditions frequently reaches beyond technologies developed for terrestrial applications, for example, by the automotive and oil industries. Therefore, space agencies require dedicated technology developments to enable these future missions. Within NASA, proposed missions are divided into three categories. Competed small (Discovery class) and medium (New Frontiers class) missions are cost capped, thus limiting significant technology developments. Therefore, large (Flagship class) missions are required not only to tackle key science questions which can't be addressed by smaller missions, but also to develop mission enabling technologies that can feed forward to smaller missions as well. In a newly completed extreme environment technology assessment at NASA, we evaluated technologies from the current State of Practice (SoP) to advanced concepts for proposed missions over the next decades. Highlights of this report are discussed here, including systems architectures, such as hybrid systems; protection systems; high temperature electronics; power generation and storage; mobility technologies; sample acquisition and mechanisms; and the need to test these technologies in relevant environments. It is expected that the findings - documented in detail in NASA's Extreme Environments Technologies report - would help identifying future technology investment areas, and in turn enable or enhance planned SSE missions, while reducing mission cost and risk.
Effects of Action Observational Training Plus Brain-Computer Interface-Based Functional Electrical Stimulation on Paretic Arm Motor Recovery in Patient with Stroke: A Randomized Controlled Trial.

PubMed

Kim, TaeHoon; Kim, SeongSik; Lee, ByoungHee

2016-03-01

The purpose of this study was to investigate whether action observational training (AOT) plus brain-computer interface-based functional electrical stimulation (BCI-FES) has a positive influence on motor recovery of paretic upper extremity in patients with stroke. This was a hospital-based, randomized controlled trial with a blinded assessor. Thirty patients with a first-time stroke were randomly allocated to one of two groups: the BCI-FES group (n = 15) and the control group (n = 15). The BCI-FES group administered to AOT plus BCI-FES on the paretic upper extremity five times per week during 4 weeks while both groups received conventional therapy. The primary outcomes were the Fugl-Meyer Assessment of the Upper Extremity, Motor Activity Log (MAL), Modified Barthel Index and range of motion of paretic arm. A blinded assessor evaluated the outcomes at baseline and 4 weeks. All baseline outcomes did not differ significantly between the two groups. After 4 weeks, the Fugl-Meyer Assessment of the Upper Extremity sub-items (total, shoulder and wrist), MAL (MAL-Activity of Use and Quality of Movement), Modified Barthel Index and wrist flexion range of motion were significantly higher in the BCI-FES group (p < 0.05). AOT plus BCI-based FES is effective in paretic arm rehabilitation by improving the upper extremity performance. The motor improvements suggest that AOT plus BCI-based FES can be used as a therapeutic tool for stroke rehabilitation. The limitations of the study are that subjects had a certain limited level of upper arm function, and the sample size was comparatively small; hence, it is recommended that future large-scale trials should consider stratified and lager populations according to upper arm function. Copyright © 2015 John Wiley & Sons, Ltd.
Order-constrained linear optimization.

PubMed

Tidwell, Joe W; Dougherty, Michael R; Chrabaszcz, Jeffrey S; Thomas, Rick P

2017-11-01

Despite the fact that data and theories in the social, behavioural, and health sciences are often represented on an ordinal scale, there has been relatively little emphasis on modelling ordinal properties. The most common analytic framework used in psychological science is the general linear model, whose variants include ANOVA, MANOVA, and ordinary linear regression. While these methods are designed to provide the best fit to the metric properties of the data, they are not designed to maximally model ordinal properties. In this paper, we develop an order-constrained linear least-squares (OCLO) optimization algorithm that maximizes the linear least-squares fit to the data conditional on maximizing the ordinal fit based on Kendall's τ. The algorithm builds on the maximum rank correlation estimator (Han, 1987, Journal of Econometrics, 35, 303) and the general monotone model (Dougherty & Thomas, 2012, Psychological Review, 119, 321). Analyses of simulated data indicate that when modelling data that adhere to the assumptions of ordinary least squares, OCLO shows minimal bias, little increase in variance, and almost no loss in out-of-sample predictive accuracy. In contrast, under conditions in which data include a small number of extreme scores (fat-tailed distributions), OCLO shows less bias and variance, and substantially better out-of-sample predictive accuracy, even when the outliers are removed. We show that the advantages of OCLO over ordinary least squares in predicting new observations hold across a variety of scenarios in which researchers must decide to retain or eliminate extreme scores when fitting data. © 2017 The British Psychological Society.
Introducing the refined gravity hypothesis of extreme sexual size dimorphism

PubMed Central

2010-01-01

Background Explanations for the evolution of female-biased, extreme Sexual Size Dimorphism (SSD), which has puzzled researchers since Darwin, are still controversial. Here we propose an extension of the Gravity Hypothesis (i.e., the GH, which postulates a climbing advantage for small males) that in conjunction with the fecundity hypothesis appears to have the most general power to explain the evolution of SSD in spiders so far. In this "Bridging GH" we propose that bridging locomotion (i.e., walking upside-down under own-made silk bridges) may be behind the evolution of extreme SSD. A biomechanical model shows that there is a physical constraint for large spiders to bridge. This should lead to a trade-off between other traits and dispersal in which bridging would favor smaller sizes and other selective forces (e.g. fecundity selection in females) would favor larger sizes. If bridging allows faster dispersal, small males would have a selective advantage by enjoying more mating opportunities. We predicted that both large males and females would show a lower propensity to bridge, and that SSD would be negatively correlated with sexual dimorphism in bridging propensity. To test these hypotheses we experimentally induced bridging in males and females of 13 species of spiders belonging to the two clades in which bridging locomotion has evolved independently and in which most of the cases of extreme SSD in spiders are found. Results We found that 1) as the degree of SSD increased and females became larger, females tended to bridge less relative to males, and that 2) smaller males and females show a higher propensity to bridge. Conclusions Physical constraints make bridging inefficient for large spiders. Thus, in species where bridging is a very common mode of locomotion, small males, by being more efficient at bridging, will be competitively superior and enjoy more mating opportunities. This "Bridging GH" helps to solve the controversial question of what keeps males small and also contributes to explain the wide range of SSD in spiders, as those spider species in which extreme SSD has not evolved but still live in tall vegetation, do not use bridging locomotion to disperse. PMID:20682029
Photoacoustic sensor for medical diagnostics

NASA Astrophysics Data System (ADS)

Wolff, Marcus; Groninga, Hinrich G.; Harde, Hermann

2004-03-01

The development of new optical sensor technologies has a major impact on the progress of diagnostic methods. Of the permanently increasing number of non-invasive breath tests, the 13C-Urea Breath Test (UBT) for the detection of Helicobacter pylori is the most prominent. However, many recent developments, like the detection of cancer by breath test, go beyond gastroenterological applications. We present a new detection scheme for breath analysis that employs an especially compact and simple set-up. Photoacoustic Spectroscopy (PAS) represents an offset-free technique that allows for short absorption paths and small sample cells. Using a single-frequency diode laser and taking advantage of acoustical resonances of the sample cell, we performed extremely sensitive and selective measurements. The smart data processing method contributes to the extraordinary sensitivity and selectivity as well. Also, the reasonable acquisition cost and low operational cost make this detection scheme attractive for many biomedical applications. The experimental set-up and data processing method, together with exemplary isotope-selective measurements on carbon dioxide, are presented.
Antibacterial performance of nano polypropylene filter media containing nano-TiO2 and clay particles

NASA Astrophysics Data System (ADS)

Shafiee, Sara; Zarrebini, Mohammad; Naghashzargar, Elham; Semnani, Dariush

2015-10-01

Disinfection and elimination of pathogenic microorganisms from liquid can be achieved by filtration process using antibacterial filter media. The advent of nanotechnology has facilitated the introduction of membranes consisting of nano-fiber in filtration operations. The melt electro-spun fibers due to their extremely small diameters are used in the production of this particular filtration medium. In this work, antibacterial polypropylene filter medium containing clay particles and nano-TiO2 were made using melt electro-spun technology. Antibacterial performance of polypropylene nano-filters was evaluated using E. coli bacteria. Additionally, filtration efficiency of the samples in terms fiber diameter, filter porosity, and fiber distribution using image processing technique was determined. Air permeability and dust aerosol tests were conducted to establish the suitability of the samples as a filter medium. It was concluded that as far as antibacterial property is concerned, nano-fibers filter media containing clay particles are preferential to similar media containing TiO2 nanoparticles.
CAMEA—A novel multiplexing analyzer for neutron spectroscopy

NASA Astrophysics Data System (ADS)

Groitl, Felix; Graf, Dieter; Birk, Jonas Okkels; Markó, Márton; Bartkowiak, Marek; Filges, Uwe; Niedermayer, Christof; Rüegg, Christian; Rønnow, Henrik M.

2016-03-01

The analyzer detector system continuous angle multiple energy analysis will be installed on the cold-neutron triple-axis spectrometer RITA-2 at SINQ, PSI. CAMEA is optimized for efficiency in the horizontal scattering plane enabling rapid and detailed mapping of excitations. As a novelty the design employs a series of several sequential upward scattering analyzer arcs. Each arc is set to a different, fixed, final energy and scatters neutrons towards position sensitive detectors. Thus, neutrons with different final energies are recorded simultaneously over a large angular range. In a single data-acquisition many entire constant-energy lines in the horizontal scattering plane are recorded for a quasi-continuous angular coverage of about 60°. With a large combined coverage in energy and momentum, this will result in a very efficient spectrometer, which will be particularly suited for parametric studies under extreme conditions with restrictive sample environments (high field magnets or pressure cells) and for small samples of novel materials. In this paper we outline the concept and the specifications of the instrument currently under construction.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Groitl, Felix, E-mail: felix.groitl@psi.ch; Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen; Graf, Dieter

The analyzer detector system continuous angle multiple energy analysis will be installed on the cold-neutron triple-axis spectrometer RITA-2 at SINQ, PSI. CAMEA is optimized for efficiency in the horizontal scattering plane enabling rapid and detailed mapping of excitations. As a novelty the design employs a series of several sequential upward scattering analyzer arcs. Each arc is set to a different, fixed, final energy and scatters neutrons towards position sensitive detectors. Thus, neutrons with different final energies are recorded simultaneously over a large angular range. In a single data-acquisition many entire constant-energy lines in the horizontal scattering plane are recorded formore » a quasi-continuous angular coverage of about 60°. With a large combined coverage in energy and momentum, this will result in a very efficient spectrometer, which will be particularly suited for parametric studies under extreme conditions with restrictive sample environments (high field magnets or pressure cells) and for small samples of novel materials. In this paper we outline the concept and the specifications of the instrument currently under construction.« less
Precise Th/U-dating of small and heavily coated samples of deep sea corals

NASA Astrophysics Data System (ADS)

Lomitschka, Michael; Mangini, Augusto

1999-07-01

Marine carbonate skeletons like deep-sea corals are frequently coated with iron and manganese oxides/hydroxides which adsorb additional thorium and uranium out of the sea water. A new cleaning procedure has been developed to reduce this contamination. In this further cleaning step a solution of Na 2EDTA (Na 2H 2T B) and ascorbic acid is used which composition is optimised especially for samples of 20 mg of weight. It was first tested on aliquots of a reef-building coral which had been artificially contaminated with powdered ferromanganese nodule. Applied on heavily contaminated deep-sea corals (scleractinia), it reduced excess 230Th by another order of magnitude in addition to usual cleaning procedures. The measurement of at least three fractions of different contamination, together with an additional standard correction for contaminated carbonates results in Th/U-ages corrected for the authigenic component. A good agreement between Th/U- and 14C-ages can be achieved even for extremely coated corals.
Phobos Environment Model and Regolith Simulant for MMX Mission

NASA Technical Reports Server (NTRS)

Miyamoto, H.; Niihara, T.; Wada, K.; Ogawa, K.; Baresi, N.; Abell, Paul A.; Asphaug, E.; Britt, D.; Dodbiba, G.; Fujita, T.;

2018-01-01

Phobos and Deimos, the two moons of Mars, are considered to be scientifically important and potential human mission's target. Martian Moons eXplorer (MMX) is the JAXA's mission to explore Phobos (and/or Deimos), which is scheduled to be launched in 2024. The main spacecraft of MMX will perform in-situ observations of both Phobos and Deimos, land on one of them (most likely, Phobos), and bring samples back to Earth. Small landing modules may be included in the mission as for the Hayabusa-2 mission. The designs of both the landing and sampling devices depend largely on the surface conditions of the target body and on how this surface reacts to an external action in the low gravity conditions of the target. Thus, the Landing Operation Working Team (LOWT) of MMX, which is composed of both scientists and engineers, is studying Phobos' surface based on previous observations and theoretical/experimental considerations. Though engineering motivation initiated this activity, the results will be extremely useful for scientific purposes.

Trends in Gender Differences in Academic Achievement from 1960 to 1994: An Analysis of Differences in Mean, Variance, and Extreme Scores.

ERIC Educational Resources Information Center

Nowell, Amy; Hedges, Larry V.

1998-01-01

Uses evidence from seven surveys of the U.S. 12th-grade population and the National Assessment of Educational Progress to show that gender differences in mean and variance in academic achievement are small from 1960 to 1994 but that differences in extreme scores are often substantial. (SLD)
Hidden morphological diversity among early tetrapods.

PubMed

Pardo, Jason D; Szostakiwskyj, Matt; Ahlberg, Per E; Anderson, Jason S

2017-06-29

Phylogenetic analysis of early tetrapod evolution has resulted in a consensus across diverse data sets in which the tetrapod stem group is a relatively homogenous collection of medium- to large-sized animals showing a progressive loss of 'fish' characters as they become increasingly terrestrial, whereas the crown group demonstrates marked morphological diversity and disparity. The oldest fossil attributed to the tetrapod crown group is the highly specialized aïstopod Lethiscus stocki, which shows a small size, extreme axial elongation, loss of limbs, spool-shaped vertebral centra, and a skull with reduced centres of ossification, in common with an otherwise disparate group of small animals known as lepospondyls. Here we use micro-computed tomography of the only known specimen of Lethiscus to provide new information that strongly challenges this consensus. Digital dissection reveals extremely primitive cranial morphology, including a spiracular notch, a large remnant of the notochord within the braincase, an open ventral cranial fissure, an anteriorly restricted parasphenoid element, and Meckelian ossifications. The braincase is elongate and lies atop a dorsally projecting septum of the parasphenoid bone, similar to stem tetrapods such as embolomeres. This morphology is consistent in a second aïstopod, Coloraderpeton, although the details differ. Phylogenetic analysis, including critical new braincase data, places aïstopods deep on the tetrapod stem, whereas another major lepospondyl lineage is displaced into the amniotes. These results show that stem group tetrapods were much more diverse in their body plans than previously thought. Our study requires a change in commonly used calibration dates for molecular analyses, and emphasizes the importance of character sampling for early tetrapod evolutionary relationships.

First Constraints on Fuzzy Dark Matter from Lyman-α Forest Data and Hydrodynamical Simulations

NASA Astrophysics Data System (ADS)

Iršič, Vid; Viel, Matteo; Haehnelt, Martin G.; Bolton, James S.; Becker, George D.

2017-07-01

We present constraints on the masses of extremely light bosons dubbed fuzzy dark matter (FDM) from Lyman-α forest data. Extremely light bosons with a de Broglie wavelength of ˜1 kpc have been suggested as dark matter candidates that may resolve some of the current small scale problems of the cold dark matter model. For the first time, we use hydrodynamical simulations to model the Lyman-α flux power spectrum in these models and compare it to the observed flux power spectrum from two different data sets: the XQ-100 and HIRES/MIKE quasar spectra samples. After marginalization over nuisance and physical parameters and with conservative assumptions for the thermal history of the intergalactic medium (IGM) that allow for jumps in the temperature of up to 5000 K, XQ-100 provides a lower limit of 7.1 ×10-22 eV , HIRES/MIKE returns a stronger limit of 14.3 ×10-22 eV , while the combination of both data sets results in a limit of 20 ×10-22 eV (2 σ C.L.). The limits for the analysis of the combined data sets increases to 37.5 ×10-22 eV (2 σ C.L.) when a smoother thermal history is assumed where the temperature of the IGM evolves as a power law in redshift. Light boson masses in the range 1 - 10 ×10-22 eV are ruled out at high significance by our analysis, casting strong doubts that FDM helps solve the "small scale crisis" of the cold dark matter models.
Light-Dependent Sulfide Oxidation in the Anoxic Zone of the Chesapeake Bay Can Be Explained by Small Populations of Phototrophic Bacteria

PubMed Central

Bennett, Alexa J.; Hanson, Thomas E.; Luther, George W.

2015-01-01

Microbial sulfide oxidation in aquatic environments is an important ecosystem process, as sulfide is potently toxic to aerobic organisms. Sulfide oxidation in anoxic waters can prevent the efflux of sulfide to aerobic water masses, thus mitigating toxicity. The contribution of phototrophic sulfide-oxidizing bacteria to anaerobic sulfide oxidation in the Chesapeake Bay and the redox chemistry of the stratified water column were investigated in the summers of 2011 to 2014. In 2011 and 2013, phototrophic sulfide-oxidizing bacteria closely related to Prosthecochloris species of the phylum Chlorobi were cultivated from waters sampled at and below the oxic-anoxic interface, where measured light penetration was sufficient to support populations of low-light-adapted photosynthetic bacteria. In 2012, 2013, and 2014, light-dependent sulfide loss was observed in freshly collected water column samples. In these samples, extremely low light levels caused 2- to 10-fold increases in the sulfide uptake rate over the sulfide uptake rate under dark conditions. An enrichment, CB11, dominated by Prosthecochloris species, oxidized sulfide with a Ks value of 11 μM and a Vmax value of 51 μM min−1 (mg protein−1). Using these kinetic values with in situ sulfide concentrations and light fluxes, we calculated that a small population of Chlorobi similar to those in enrichment CB11 can account for the observed anaerobic light-dependent sulfide consumption activity in natural water samples. We conclude that Chlorobi play a far larger role in the Chesapeake Bay than currently appreciated. This result has potential implications for coastal anoxic waters and expanding oxygen-minimum zones as they begin to impinge on the photic zone. PMID:26296727
Can Concentration - Discharge Relationships Diagnose Material Source During Extreme Events?

NASA Astrophysics Data System (ADS)

Karwan, D. L.; Godsey, S.; Rose, L.

2017-12-01

Floods can carry >90% of the basin material exported in a given year as well as alter flow pathways and material sources. In turn, sediment and solute fluxes can increase flood damages and negatively impact water quality and integrate physical and chemical weathering of landscapes and channels. Concentration-discharge (C-Q) relationships are used to both describe export patterns as well as compute them. Metrics for describing C-Q patterns and inferring their controls are vulnerable to infrequent sampling that affects how C-Q relationships are interpolated and interpreted. C-Q relationships are typically evaluated from multiple samples, but because hydrological extremes are rare, data are often unavailable for extreme events. Because solute and sediment C-Q relationships likely respond to changes in hydrologic extremes in different ways, there is a pressing need to define their behavior under extreme conditions, including how to properly sample to capture these patterns. In the absence of such knowledge, improving load estimates in extreme floods will likely remain difficult. Here we explore the use of C-Q relationships to determine when an event alters a watershed system such that it enters a new material source/transport regime. We focus on watersheds with sediment and discharge time series include low-frequency and/or extreme events. For example, we compare solute and sediment patterns in White Clay Creek in southeastern Pennsylvania across a range of flows inclusive of multiple hurricanes for which we have ample ancillary hydrochemical data. TSS is consistently mobilized during high flow events, even during extreme floods associated with hurricanes, and sediment fingerprinting indicates different sediment sources, including in-channel remobilization and landscape erosion, are active at different times. In other words, TSS mobilization in C-Q space is not sensitive to the source of material being mobilized. Unlike sediments, weathering solutes in this watershed tend to exhibit a relatively chemostatic C-Q pattern, except during the runoff-dominated Hurricane Irene, when they exhibit a diluting C-Q pattern. Finally, we summarize the vulnerability of these observations to shifts in sampling effort to highlight the utility and limitations of C-Q-derived export patterns.
EFFECTS OF AGE AND ACUTE MUSCLE FATIGUE ON REACTIVE POSTURAL CONTROL IN HEALTHY ADULTS

PubMed Central

Papa, Evan V.; Foreman, K. Bo; Dibble, Lee E.

2015-01-01

BACKGROUND Falls can cause moderate to severe injuries such as hip fractures and head trauma in older adults. While declines in muscle strength and sensory function contribute to increased falls in older adults, skeletal muscle fatigue is often overlooked as an additional contributor to fall risk. The purpose of this investigation was to examine the effects of acute lower extremity muscle fatigue and age on reactive postural control in healthy adults. METHODS A sample of 16 individuals participated in this study (8 healthy older adults and 8 healthy young persons). Whole body kinematic and kinetic data were collected during anterior and posterior reproducible fall tests before (T0) and immediately after (T1) eccentric muscle fatiguing exercise, as well as after 15-minutes (T15) and 30-minutes (T30) of rest. FINDINGS Lower extremity joint kinematics of the stepping limb during the support (landing) phase of the anterior fall were significantly altered by the presence of acute muscle fatigue. Step velocity was significantly decreased during the anterior falls. Statistically significant main effects of age were found for step length in both fall directions. Effect sizes for all outcomes were small. No statistically significant interaction effects were found. INTERPRETATION Muscle fatigue has a measurable effect on lower extremity joint kinematics during simulated falls. These alterations appear to resolve within 15 minutes of recovery. The above deficits, coupled with a reduced step length, may help explain the increased fall risk in older adults. PMID:26351001
Effects of age and acute muscle fatigue on reactive postural control in healthy adults.

PubMed

Papa, Evan V; Foreman, K Bo; Dibble, Leland E

2015-12-01

Falls can cause moderate to severe injuries such as hip fractures and head trauma in older adults. While declines in muscle strength and sensory function contribute to increased falls in older adults, skeletal muscle fatigue is often overlooked as an additional contributor to fall risk. The purpose of this investigation was to examine the effects of acute lower extremity muscle fatigue and age on reactive postural control in healthy adults. A sample of 16 individuals participated in this study (8 healthy older adults and 8 healthy young persons). Whole body kinematic and kinetic data were collected during anterior and posterior reproducible fall tests before (T0) and immediately after (T1) eccentric muscle fatiguing exercise, as well as after 15-min (T15) and 30-min (T30) of rest. Lower extremity joint kinematics of the stepping limb during the support (landing) phase of the anterior fall were significantly altered by the presence of acute muscle fatigue. Step velocity was significantly decreased during the anterior falls. Statistically significant main effects of age were found for step length in both fall directions. Effect sizes for all outcomes were small. No statistically significant interaction effects were found. Muscle fatigue has a measurable effect on lower extremity joint kinematics during simulated falls. These alterations appear to resolve within 15 min of recovery. The above deficits, coupled with a reduced step length, may help explain the increased fall risk in older adults. Copyright © 2015 Elsevier Ltd. All rights reserved.
Predicting the solubility of gases in Nitrile Butadiene Rubber in extreme conditions using molecular simulation

NASA Astrophysics Data System (ADS)

Khawaja, Musab; Molinari, Nicola; Sutton, Adrian; Mostofi, Arash

In the oil and gas industry, elastomer seals play an important role in protecting sensitive monitoring equipment from contamination by gases - a problem that is exacerbated by the high pressures and temperatures found down-hole. The ability to predict and prevent such permeative failure has proved elusive to-date. Nitrile butadiene rubber (NBR) is a common choice of elastomer for seals due to its resistance to heat and fuels. In the conditions found in the well it readily absorbs small molecular weight gases. How this behaviour changes quantitatively for different gases as a function of temperature and pressure is not well-understood. In this work a series of fully atomistic simulations are performed to understand the effect of extreme conditions on gas solubility in NBR. Widom particle insertion is used to compute solubilities. The importance of sampling and allowing structural relaxation upon compression are highlighted, and qualitatively reasonable trends reproduced. Finally, while at STP it has previously been shown that the solubility of CO2 is higher than that of He in NBR, we observe that under the right circumstances it is possible to reverse this trend.
[Analytical chemistry in works of Maria Skłodowska-Curie].

PubMed

Hulanicki, Adam

2012-01-01

Maria Skłodowska-Curie--a Nobel Prize winner in chemistry--the elements of learning of chemistry gained just by a dint of work of more than ten months in Warsaw in the Institute of Industry and Agriculture Museum. The Nobel Prize concerned a contribution to the progress of chemistry through the discovery of radium and polonium, separation of radium and study of properties of this amazing element. It was awarded for an extremely arduous work, during which the chemical reactions being the principles of analytical chemistry were realized. Unlike to a typical analytical procedure, an initial attempt here was the thousands of kilograms of uranium ore: pitchblende. The final effect was small amounts of new elements: polonium and radium. Both the knowledge and the intuition of the researcher let her have a triumph. The difficulties she experienced because the properties of the searched chemical elements could only be evaluated thanks to the knowledge on other chemical elements. A significant achievement was the determination of the samples by means of radioactivity measurement, which gave rise to radiochemical analytical methods. An extreme analytical precision was demanded in multiple processes of fractional crystallization and precipitation which finally led to the calculation of the atomic mass of radium.
Pushing the Volcanic Explosivity Index to its limit and beyond: Constraints from exceptionally weak explosive eruptions at Kīlauea in 2008

USGS Publications Warehouse

Houghton, Bruce F.; Swanson, Don; Rausch, J.; Carey, R.J.; Fagents, S.A.; Orr, Tim R.

2013-01-01

Estimating the mass, volume, and dispersal of the deposits of very small and/or extremely weak explosive eruptions is difficult, unless they can be sampled on eruption. During explosive eruptions of Halema‘uma‘u Crater (Kīlauea, Hawaii) in 2008, we constrained for the first time deposits of bulk volumes as small as 9–300 m3 (1 × 104 to 8 × 105 kg) and can demonstrate that they show simple exponential thinning with distance from the vent. There is no simple fit for such products within classifications such as the Volcanic Explosivity Index (VEI). The VEI is being increasingly used as the measure of magnitude of explosive eruptions, and as an input for both hazard modeling and forecasting of atmospheric dispersal of tephra. The 2008 deposits demonstrate a problem for the use of the VEI, as originally defined, which classifies small, yet ballistic-producing, explosive eruptions at Kīlauea and other basaltic volcanoes as nonexplosive. We suggest a simple change to extend the scale in a fashion inclusive of such very small deposits, and to make the VEI more consistent with other magnitude scales such as the Richter scale for earthquakes. Eruptions of this magnitude constitute a significant risk at Kīlauea and elsewhere because of their high frequency and the growing number of “volcano tourists” visiting basaltic volcanoes.
Relationship between hyperemesis gravidarum and small-for-gestational-age in the Japanese population: the Japan Environment and Children's Study (JECS).

PubMed

Morokuma, Seiichi; Shimokawa, Mototsugu; Kato, Kiyoko; Sanefuji, Masafumi; Shibata, Eiji; Tsuji, Mayumi; Senju, Ayako; Kawamoto, Toshihiro; Kusuhara, Koichi

2016-08-26

Small-for-gestational-age in infancy is a known risk factor not only for short-term prognosis but also for several long-term outcomes, such as neurological and metabolic disorders in adulthood. Previous research has shown that severe nausea and vomiting in early pregnancy (NVP) and hyperemesis gravidarum, which is an extreme form of NVP, represent risk factors for small-for-gestational-age birth. However, there is no clear consensus on this association. Thus, in the present study, we investigated the correlation between hyperemesis gravidarum and NVP on the one hand, and infant birth weight on the other, using data from the Japan Environment and Children's Study (JECS). The data utilized in the present study were obtained from the JECS, an ongoing cohort study that began in January 2011. Our sample size was 8635 parent-child pairs. The presence or absence of severe NVP, hyperemesis gravidarum, and potential confounding factors were noted. A multivariable regression analysis was used to estimate risks for small-for-gestational-age birth, and the results were expressed as risk ratios and 95 % confidence intervals. The risk ratios of small-for-gestational-age birth (95 % confidence interval) for mothers with severe NVP and those with hyperemesis gravidarum were 0.86 (0.62-1.19) and 0.81 (0.39-1.66), respectively, which represents a non-significant result. In our analysis of JECS data, neither severe NVP nor hyperemesis gravidarum was associated with increased risk for small-for-gestational-age birth.
Determination of cadmium in grains by isotope dilution ICP-MS and coprecipitation using sample constituents as carrier precipitants.

PubMed

Inagaki, Kazumi; Narukawa, Tomohiro; Yarita, Takashi; Takatsu, Akiko; Okamoto, Kensaku; Chiba, Koichi

2007-10-01

A coprecipitation method using sample constituents as carrier precipitants was developed that can remove molybdenum, which interferes with the determination of cadmium in grain samples via isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). Samples were digested with HNO3, HF, and HClO4, and then purified 6 M sodium hydroxide solution was added to generate colloidal hydrolysis compounds, mainly magnesium hydroxide. Cadmium can be effectively separated from molybdenum because the cadmium forms hydroxides and adsorbs onto and/or is occluded in the colloid, while the molybdenum does not form hydroxides or adsorb onto the hydrolysis colloid. The colloid was separated by centrifugation and then dissolved with 0.2 M HNO3 solution to recover the cadmium. The recovery of Cd achieved using the coprecipitation was >97%, and the removal efficiency of Mo was approximately 99.9%. An extremely low procedural blank (below the detection limit of ICPMS) was achieved by purifying the 6 M sodium hydroxide solution via Mg coprecipitation using Mg(NO3)2 solution. The proposed method was applied to two certified reference materials (NIST SRM 1567a wheat flour and SRM 1568a rice flour) and CCQM-P64 soybean powder. Good analytical results with small uncertainties were obtained for all samples. This method is simple and reliable for the determination of Cd in grain samples by ID-ICPMS.
The Indigo V Indian Ocean Expedition: a prototype for citizen microbial oceanography

NASA Astrophysics Data System (ADS)

Lauro, Federico; Senstius, Jacob; Cullen, Jay; Lauro, Rachelle; Neches, Russell; Grzymski, Joseph

2014-05-01

Microbial Oceanography has long been an extremely expensive discipline, requiring ship time for sample collection and thereby economically constraining the number of samples collected. This is especially true for under-sampled water bodies such as the Indian Ocean. Specialised scientific equipment only adds to the costs. Moreover, long term monitoring of microbial communities and large scale modelling of global biogeochemical cycles requires the collection of high-density data both temporally and spatially in a cost-effective way. Thousands of private ocean-going vessels are cruising around the world's oceans every day. We believe that a combination of new technologies, appropriate laboratory protocols and strategic operational partnerships will allow researchers to broaden the scope of participation in basic oceanographic research. This will be achieved by equipping sailing vessels with small, satcom-equipped sampling devices, user-friendly collection techniques and a 'pre-addressed-stamped-envelope' to send in the samples for analysis. We aim to prove that 'bigger' is not necessarily 'better' and the key to greater understanding of the world's oceans is to forge the way to easier and cheaper sample acquisition. The ultimate goal of the Indigo V Expedition is to create a working blue-print for 'citizen microbial oceanography'. We will present the preliminary outcomes of the first Indigo V expedition, from Capetown to Singapore, highlighting the challenges and opportunities of such endeavours.
Regioselective Synthesis of Cellulose Ester Homopolymers

Treesearch

Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

2012-01-01

Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...
Particles, particles everywhere: What is in the air we breathe?

USDA-ARS?s Scientific Manuscript database

Particulate matter (PM) air pollution consists of extremely small particles, some so small that they can directly enter the bloodstream through the lungs. PM is of prime concern from both health and environmental perspectives. Current research is focused on understanding how PM forms in the atmosphe...
Compilation of 1985 annual reports of the Navy elf (extremely low frequency) communications system ecological monitoring program. Volume 2. Tabs D-G. Annual progress report, January-December 1985

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

Band, R.N.; Snider, R.J.; Snider, R.M.

1986-07-01

This volume consists of the following reports: Soil Amoeba; Soil and Litter Arthropoda and Earthworm Studies; Biological Studies on Pollinating Insects: Megachilid Bees; Small Vertebrates: Small Mammals and Nesting Birds.
Mars-like soils in the Atacama Desert, Chile, and the dry limit of microbial life.

PubMed

Navarro-González, Rafael; Rainey, Fred A; Molina, Paola; Bagaley, Danielle R; Hollen, Becky J; de la Rosa, José; Small, Alanna M; Quinn, Richard C; Grunthaner, Frank J; Cáceres, Luis; Gomez-Silva, Benito; McKay, Christopher P

2003-11-07

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme arid region were tested for DNA and none was recovered. Incubation experiments, patterned after the Viking labeled-release experiment but with separate biological and nonbiological isomers, show active decomposition of organic species in these soils by nonbiological processes.
Complexity-aware simple modeling.

PubMed

Gómez-Schiavon, Mariana; El-Samad, Hana

2018-02-26

Mathematical models continue to be essential for deepening our understanding of biology. On one extreme, simple or small-scale models help delineate general biological principles. However, the parsimony of detail in these models as well as their assumption of modularity and insulation make them inaccurate for describing quantitative features. On the other extreme, large-scale and detailed models can quantitatively recapitulate a phenotype of interest, but have to rely on many unknown parameters, making them often difficult to parse mechanistically and to use for extracting general principles. We discuss some examples of a new approach-complexity-aware simple modeling-that can bridge the gap between the small-scale and large-scale approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.
Instability of Poiseuille flow at extreme Mach numbers: linear analysis and simulations.

PubMed

Xie, Zhimin; Girimaji, Sharath S

2014-04-01

We develop the perturbation equations to describe instability evolution in Poiseuille flow at the limit of very high Mach numbers. At this limit the equation governing the flow is the pressure-released Navier-Stokes equation. The ensuing semianalytical solution is compared against simulations performed using the gas-kinetic method (GKM), resulting in excellent agreement. A similar comparison between analytical and computational results of small perturbation growth is performed at the incompressible (zero Mach number) limit, again leading to excellent agreement. The study accomplishes two important goals: it (i) contrasts the small perturbation evolution in Poiseuille flows at extreme Mach numbers and (ii) provides important verification of the GKM simulation scheme.
Advanced sampling techniques for hand-held FT-IR instrumentation

NASA Astrophysics Data System (ADS)

Arnó, Josep; Frunzi, Michael; Weber, Chris; Levy, Dustin

2013-05-01

FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenging ConOps in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, extreme reliability, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the HazMatID™ Elite, a FT-IR instrument designed to balance the portability advantages of a handheld device with the performance challenges associated with miniaturization. In this paper, special focus will be given to the HazMatID Elite's sampling interfaces optimized to collect and interrogate different types of samples: accumulated material using the on-board ATR press, dispersed powders using the ClearSampler™ tool, and the touch-to-sample sensor for direct liquid sampling. The application of the novel sample swipe accessory (ClearSampler) to collect material from surfaces will be discussed in some detail. The accessory was tested and evaluated for the detection of explosive residues before and after detonation. Experimental results derived from these investigations will be described in an effort to outline the advantages of this technology over existing sampling methods.
Calibration techniques and results in the soft X-ray and extreme ultraviolet for components of the Extreme Ultraviolet Explorer Satellite

NASA Technical Reports Server (NTRS)

Malina, Roger F.; Jelinsky, Patrick; Bowyer, Stuart

1986-01-01

The calibration facilities and techniques for the Extreme Ultraviolet Explorer (EUVE) from 44 to 2500 A are described. Key elements include newly designed radiation sources and a collimated monochromatic EUV beam. Sample results for the calibration of the EUVE filters, detectors, gratings, collimators, and optics are summarized.
Bidirectional reflectance distribution function of diffuse extreme ultraviolet scatterers and extreme ultraviolet baffle materials.

PubMed

Newell, M P; Keski-Kuha, R A

1997-08-01

Bidirectional reflectance distribution function (BRDF) measurements of a number of diffuse extreme ultraviolet (EUV) scatterers and EUV baffle materials have been performed with the Goddard EUV scatterometer. BRDF data are presented for white Spectralon SRS-99 at 121.6 nm; the data exhibit a non-Lambertian nature and a total hemispherical reflectance lower than 0.15. Data are also presented for an evaporated Cu black sample, a black Spectralon SRS-02 sample, and a Martin Optical Black sample at wavelengths of 58.4 and 121.6 nm and for angles of incidence of 15 degrees and 45 degrees. Overall Martin Optical Black exhibited the lowest BRDF characteristic, with a total hemispherical reflectance of the order of 0.01 and measured BRDF values as low as 2 x 10(-3) sr(-1).

Design of a New Ultracompact Resonant Plasmonic Multi-Analyte Label-Free Biosensing Platform

PubMed Central

De Palo, Maripina; Ciminelli, Caterina

2017-01-01

In this paper, we report on the design of a bio-multisensing platform for the selective label-free detection of protein biomarkers, carried out through a 3D numerical algorithm. The platform includes a number of biosensors, each of them is based on a plasmonic nanocavity, consisting of a periodic metal structure to be deposited on a silicon oxide substrate. Light is strongly confined in a region with extremely small size (=1.57 μm2), to enhance the light-matter interaction. A surface sensitivity Ss = 1.8 nm/nm has been calculated together with a detection limit of 128 pg/mm2. Such performance, together with the extremely small footprint, allow the integration of several devices on a single chip to realize extremely compact lab-on-chip microsystems. In addition, each sensing element of the platform has a good chemical stability that is guaranteed by the selection of gold for its fabrication. PMID:28783075
Extremophiles in Household Water Heaters

NASA Astrophysics Data System (ADS)

Wilpiszeski, R.; House, C. H.

2016-12-01

A significant fraction of Earth's microbial diversity comes from species living in extreme environments, but natural extreme environments can be difficult to access. Manmade systems like household water heaters serve as an effective proxy for thermophilic environments that are otherwise difficult to sample directly. As such, we are investigating the biogeography, taxonomic distribution, and evolution of thermophiles growing in domestic water heaters. Citizen scientists collected hot tap water culture- and filter- samples from 101 homes across the United States. We recovered a single species of thermophilic heterotroph from culture samples inoculated from water heaters across the United States, Thermus scotoductus. Whole-genome sequencing was conducted to better understand the distribution and evolution of this single species. We have also sequenced hyper-variable regions of the 16S rRNA gene from whole-community filter samples to identify the broad diversity and distribution of microbial cells captured from each water heater. These results shed light on the processes that shape thermophilic populations and genomes at a spatial resolution that is difficult to access in naturally occurring extreme ecosystems.
Repeated Small Bowel Obstruction Caused by Chestnut Ingestion without the Formation of Phytobezoars.

PubMed

Satake, Ryu; Chinda, Daisuke; Shimoyama, Tadashi; Satake, Miwa; Oota, Rie; Sato, Satoshi; Yamai, Kiyonori; Hachimori, Hisashi; Okamoto, Yutaka; Yamada, Kyogo; Matsuura, Osamu; Hashizume, Tadashi; Soma, Yasushi; Fukuda, Shinsaku

2016-01-01

A small number of cases of small bowel obstruction caused by foods without the formation of phytobezoars have been reported. Repeated small bowel obstruction due to the ingestion of the same food is extremely rare. We present the case of 63-year-old woman who developed small bowel obstruction twice due to the ingestion of chestnuts without the formation of phytobezoars. This is the first reported case of repeated small bowel obstruction caused by chestnut ingestion. Careful interviews are necessary to determine the meal history of elderly patients and psychiatric patients.
Are extreme events (statistically) special? (Invited)

NASA Astrophysics Data System (ADS)

Main, I. G.; Naylor, M.; Greenhough, J.; Touati, S.; Bell, A. F.; McCloskey, J.

2009-12-01

We address the generic problem of testing for scale-invariance in extreme events, i.e. are the biggest events in a population simply a scaled model of those of smaller size, or are they in some way different? Are large earthquakes for example ‘characteristic’, do they ‘know’ how big they will be before the event nucleates, or is the size of the event determined only in the avalanche-like process of rupture? In either case what are the implications for estimates of time-dependent seismic hazard? One way of testing for departures from scale invariance is to examine the frequency-size statistics, commonly used as a bench mark in a number of applications in Earth and Environmental sciences. Using frequency data however introduces a number of problems in data analysis. The inevitably small number of data points for extreme events and more generally the non-Gaussian statistical properties strongly affect the validity of prior assumptions about the nature of uncertainties in the data. The simple use of traditional least squares (still common in the literature) introduces an inherent bias to the best fit result. We show first that the sampled frequency in finite real and synthetic data sets (the latter based on the Epidemic-Type Aftershock Sequence model) converge to a central limit only very slowly due to temporal correlations in the data. A specific correction for temporal correlations enables an estimate of convergence properties to be mapped non-linearly on to a Gaussian one. Uncertainties closely follow a Poisson distribution of errors across the whole range of seismic moment for typical catalogue sizes. In this sense the confidence limits are scale-invariant. A systematic sample bias effect due to counting whole numbers in a finite catalogue makes a ‘characteristic’-looking type extreme event distribution a likely outcome of an underlying scale-invariant probability distribution. This highlights the tendency of ‘eyeball’ fits to unconsciously (but wrongly in this case) assume Gaussian errors. We develop methods to correct for these effects, and show that the current best fit maximum likelihood regression model for the global frequency-moment distribution in the digital era is a power law, i.e. mega-earthquakes continue to follow the Gutenberg-Richter trend of smaller earthquakes with no (as yet) observable cut-off or characteristic extreme event. The results may also have implications for the interpretation of other time-limited geophysical time series that exhibit power-law scaling.
Testing for scale-invariance in extreme events, with application to earthquake occurrence

NASA Astrophysics Data System (ADS)

Main, I.; Naylor, M.; Greenhough, J.; Touati, S.; Bell, A.; McCloskey, J.

2009-04-01

We address the generic problem of testing for scale-invariance in extreme events, i.e. are the biggest events in a population simply a scaled model of those of smaller size, or are they in some way different? Are large earthquakes for example ‘characteristic', do they ‘know' how big they will be before the event nucleates, or is the size of the event determined only in the avalanche-like process of rupture? In either case what are the implications for estimates of time-dependent seismic hazard? One way of testing for departures from scale invariance is to examine the frequency-size statistics, commonly used as a bench mark in a number of applications in Earth and Environmental sciences. Using frequency data however introduces a number of problems in data analysis. The inevitably small number of data points for extreme events and more generally the non-Gaussian statistical properties strongly affect the validity of prior assumptions about the nature of uncertainties in the data. The simple use of traditional least squares (still common in the literature) introduces an inherent bias to the best fit result. We show first that the sampled frequency in finite real and synthetic data sets (the latter based on the Epidemic-Type Aftershock Sequence model) converge to a central limit only very slowly due to temporal correlations in the data. A specific correction for temporal correlations enables an estimate of convergence properties to be mapped non-linearly on to a Gaussian one. Uncertainties closely follow a Poisson distribution of errors across the whole range of seismic moment for typical catalogue sizes. In this sense the confidence limits are scale-invariant. A systematic sample bias effect due to counting whole numbers in a finite catalogue makes a ‘characteristic'-looking type extreme event distribution a likely outcome of an underlying scale-invariant probability distribution. This highlights the tendency of ‘eyeball' fits unconsciously (but wrongly in this case) to assume Gaussian errors. We develop methods to correct for these effects, and show that the current best fit maximum likelihood regression model for the global frequency-moment distribution in the digital era is a power law, i.e. mega-earthquakes continue to follow the Gutenberg-Richter trend of smaller earthquakes with no (as yet) observable cut-off or characteristic extreme event. The results may also have implications for the interpretation of other time-limited geophysical time series that exhibit power-law scaling.
A Reconnaissance of the 900-1200 A Spectra of Early O Stars in the Magellanic Clouds

NASA Technical Reports Server (NTRS)

Walborn, Nolan

1999-01-01

Far-UV spectrograms of ten very hot stars in the Magellanic Clouds were obtained with the Hopkins Ultraviolet Telescope during the Astro-2 mission in March 1995. Very few normal OB stars were observed during Astro-1, and the only significant prior sample of such objects in this wavelength range was that obtained by Copernicus of stars near the Sun. The Magellanic Cloud sample offers the advantages of low reddening, a range in metallicity, and more extreme temperatures and luminosities than represented in the near solar neighborhood. Several interesting phenomena were found in the HUT MC sample, including very strong O VI wind profiles in O3 spectra; anomalous CNO wind features corresponding to abundances altered by stellar nucleosynthesis; weak wind features due to the metal deficiency of the Small Magellanic Cloud; and interstellar molecular hydrogen features originating in the MCs. The results were presented and discussed as a small atlas, and they were shown at the Pittsburgh AAS meeting in June 1995. A correlative atlas of Copernicus data was also prepared and published under the auspices of this grant. These publications will serve as resources for the characterization of the FUSE observations of related objects to hopefully be obtained soon. I believe that the large differences among the strong wind features in the HUT data, corresponding to CNO and systemic metallicity effects, are amenable to some relative quantitative analysis, and I shall endeavor to promote such in conjunction with HST data at longer wavelengths for the same stars (which has also not yet been completely analyzed) at a future opportunity.
Analysis of nonuniformity in intron phase distribution.

PubMed Central

Fedorov, A; Suboch, G; Bujakov, M; Fedorova, L

1992-01-01

The distribution of different intron groups with respect to phases has been analyzed. It has been established that group II introns and nuclear introns have a minimum frequency of phase 2 introns. Since the phase of introns is an extremely conservative measure the observed minimum reflects evolutionary processes. A sample of all known, group I introns was too small to provide a valid characteristic of their phase distribution. The findings observed for the unequal distribution of phases cannot be explained solely on the basis of the mobile properties of introns. One of the most likely explanations for this nonuniformity in the intron phase distribution is the process of exon shuffling. It is proposed that group II introns originated at the early stages of evolution and were involved in the process of exon shuffling. PMID:1598214
Evaluation of unsaturated zone water fluxes in heterogeneous alluvium at a Mojave Basin Site

USGS Publications Warehouse

Nimmo, John R.; Deason, Jeffrey A.; Izbicki, John A.; Martin, Peter

2002-01-01

Vertical and horizontal water fluxes in the unsaturated zone near intermittent streams critically affect ecosystems, water supply, and contaminant transport in arid and semiarid regions. The subsurface near the Oro Grande Wash is typical in having great textural diversity, pronounced layer contrasts, and extremely low hydraulic conductivities associated with nearly dry media. These features prevent a straightforward application of the Darcian method for recharge estimation, which has provided high‐quality flux estimates at simpler, wetter sites. We have augmented the basic Darcian method with theoretical developments such that a small number of core sample unsaturated hydraulic property measurements, combined with additional, easily obtained data (e.g., drillers' logs) can provide useful flux estimates and knowledge of two‐dimensional water behavior beneath the wash.
Towards Measurement of the Time-resolved Heat Release of Protein Conformation Dynamics

NASA Technical Reports Server (NTRS)

Puchalla, Jason; Adamek, Daniel; Austin, Robert

2004-01-01

We present a way to observe time-resolved heat release using a laminar flow diffusional mixer coupled with a highly sensitive infrared camera which measures the temperature change of the solvent. There are significant benefits to the use of laminar flow mixers for time-resolved calorimetry: (1) The thermal signal can be made position and time- stationary to allow for signal integration; (2) Extremely small volumes (nl/s) of sample are required for a measurement; (3) The same mixing environment can be observed spectroscopically to obtain state occupation information; (4) The mixer allows one to do out of equilibrium dynamic studies. The hope is that these measurements will allow us probe the non-equilibrium thermodynamics as a protein moves along a free energy trajectory from one state to another.
Forensic analysis of dyed textile fibers.

PubMed

Goodpaster, John V; Liszewski, Elisa A

2009-08-01

Textile fibers are a key form of trace evidence, and the ability to reliably associate or discriminate them is crucial for forensic scientists worldwide. While microscopic and instrumental analysis can be used to determine the composition of the fiber itself, additional specificity is gained by examining fiber color. This is particularly important when the bulk composition of the fiber is relatively uninformative, as it is with cotton, wool, or other natural fibers. Such analyses pose several problems, including extremely small sample sizes, the desire for nondestructive techniques, and the vast complexity of modern dye compositions. This review will focus on more recent methods for comparing fiber color by using chromatography, spectroscopy, and mass spectrometry. The increasing use of multivariate statistics and other data analysis techniques for the differentiation of spectra from dyed fibers will also be discussed.
Total variation-based neutron computed tomography

NASA Astrophysics Data System (ADS)

Barnard, Richard C.; Bilheux, Hassina; Toops, Todd; Nafziger, Eric; Finney, Charles; Splitter, Derek; Archibald, Rick

2018-05-01

We perform the neutron computed tomography reconstruction problem via an inverse problem formulation with a total variation penalty. In the case of highly under-resolved angular measurements, the total variation penalty suppresses high-frequency artifacts which appear in filtered back projections. In order to efficiently compute solutions for this problem, we implement a variation of the split Bregman algorithm; due to the error-forgetting nature of the algorithm, the computational cost of updating can be significantly reduced via very inexact approximate linear solvers. We present the effectiveness of the algorithm in the significantly low-angular sampling case using synthetic test problems as well as data obtained from a high flux neutron source. The algorithm removes artifacts and can even roughly capture small features when an extremely low number of angles are used.
The evolution of extreme precipitations in high resolution scenarios over France

NASA Astrophysics Data System (ADS)

Colin, J.; Déqué, M.; Somot, S.

2009-09-01

Over the past years, improving the modelling of extreme events and their variability at climatic time scales has become one of the challenging issue raised in the regional climate research field. This study shows the results of a high resolution (12 km) scenario run over France with the limited area model (LAM) ALADIN-Climat, regarding the representation of extreme precipitations. The runs were conducted in the framework of the ANR-SCAMPEI national project on high resolution scenarios over French mountains. As a first step, we attempt to quantify one of the uncertainties implied by the use of LAM : the size of the area on which the model is run. In particular, we address the issue of whether a relatively small domain allows the model to create its small scale process. Indeed, high resolution scenarios cannot be run on large domains because of the computation time. Therefore one needs to answer this preliminary question before producing and analyzing such scenarios. To do so, we worked in the framework of a « big brother » experiment. We performed a 23-year long global simulation in present-day climate (1979-2001) with the ARPEGE-Climat GCM, at a resolution of approximately 50 km over Europe (stretched grid). This first simulation, named ARP50, constitutes the « big brother » reference of our experiment. It has been validated in comparison with the CRU climatology. Then we filtered the short waves (up to 200 km) from ARP50 in order to obtain the equivalent of coarse resolution lateral boundary conditions (LBC). We have carried out three ALADIN-Climat simulations at a 50 km resolution with these LBC, using different configurations of the model : * FRA50, run over a small domain (2000 x 2000 km, centered over France), * EUR50, run over a larger domain (5000 x 5000 km, centered over France as well), * EUR50-SN, run over the large domain (using spectral nudging). Considering the facts that ARPEGE-Climat and ALADIN-Climat models share the same physics and dynamics and that both regional and global simulations were run at the same resolution, ARP50 can be regarded as a reference with which FRA50, EUR50 and EUR50-SN should each be compared. After an analysis of the differences between the regional simulations and ARP50 in annual and seasonal mean, we focus on the representation of rainfall extremes comparing two dimensional fields of various index inspired from STARDEX and quantile-quantile plots. The results show a good agreement with the ARP50 reference for all three regional simulations and little differences are found between them. This result indicates that the use of small domains is not significantly detrimental to the modelling of extreme precipitation events. It also shows that the spectral nudging technique has no detrimental effect on the extreme precipitation. Therefore, high resolution scenarios performed on a relatively small domain such as the ones run for SCAMPEI, can be regarded as good tools to explore their possible evolution in the future climate. Preliminary results on the response of precipitation extremes over South-East France are given.
Work-related burns.

PubMed

Pruitt, Valerie M

2006-01-01

Work-related upper extremity burns often occur. The cause directs the course of action. Thermal burns should be assessed for system alterations, and depth of burn should be determined. Deep partial-thickness burns and more severe burns require a specialist evaluation. Chemical burns must be irrigated and the agent identified. Some chemical burns, such as those that involve phenols and metal fragments, require specific topical applications before water lavage. Hydrofluoric acid burns can cause life-threatening electrolyte abnormalities with a small, highly concentrated acid burn. The goal with any extremity burn is to provide the patient with a multidisciplinary team approach to achieve a functional, usable extremity.
Controllable gaussian-qubit interface for extremal quantum state engineering.

PubMed

Adesso, Gerardo; Campbell, Steve; Illuminati, Fabrizio; Paternostro, Mauro

2010-06-18

We study state engineering through bilinear interactions between two remote qubits and two-mode gaussian light fields. The attainable two-qubit states span the entire physically allowed region in the entanglement-versus-global-purity plane. Two-mode gaussian states with maximal entanglement at fixed global and marginal entropies produce maximally entangled two-qubit states in the corresponding entropic diagram. We show that a small set of parameters characterizing extremally entangled two-mode gaussian states is sufficient to control the engineering of extremally entangled two-qubit states, which can be realized in realistic matter-light scenarios.
Study design for a hepatitis B vaccine trial.

PubMed Central

Lustbader, E D; London, W T; Blumberg, B S

1976-01-01

A short-time trial of small sample size for an evaluation of the hepatitis B vaccine is proposed and designed. The vaccine is based on the premise that antibody to the surface antigen of the hepatitis B virus is protective against viral infection. This premise is verified by using the presence of the surface antigen as the marker of infection and comparing infection rates in renal dialysis patients who had naturally acquired antibody to patients without antibody. Patients with antibody have an extremely low risk of infection. The probability of remaining uninfected decreases at an exponential rate for patients without antibody, implying a constant risk of infection at any point in time. The study design described makes use of this time independence and the observed infection rates to formulate a clinical trial which can be accomplished with a relatively small number of patients. This design might be useful if, in preliminary studies, it is shown that the vaccine produces antibody in the patients and that protection against hepatitis B virus would be beneficial to the patients. PMID:1062809
A New Paradigm in Earth Environmental Monitoring with the CYGNSS Small Satellite Constellation.

PubMed

Ruf, Christopher S; Chew, Clara; Lang, Timothy; Morris, Mary G; Nave, Kyle; Ridley, Aaron; Balasubramaniam, Rajeswari

2018-06-08

A constellation of small, low-cost satellites is able to make scientifically valuable measurements of the Earth which can be used for weather forecasting, disaster monitoring, and climate studies. Eight CYGNSS satellites were launched into low Earth orbit on December 15, 2016. Each satellite carries a science radar receiver which measures GPS signals reflected from the Earth surface. The signals contain information about the surface, including wind speed over ocean, and soil moisture and flooding over land. The satellites are distributed around their orbit plane so that measurements can be made more often to capture extreme weather events. Innovative engineering approaches are used to reduce per satellite cost, increase the number in the constellation, and improve temporal sampling. These include the use of differential drag rather than propulsion to adjust the spacing between satellites and the use of existing GPS signals as the science radars' transmitter. Initial on-orbit results demonstrate the scientific utility of the CYGNSS observations, and suggest that a new paradigm in spaceborne Earth environmental monitoring is possible.
Generating Health Estimates by Zip Code: A Semiparametric Small Area Estimation Approach Using the California Health Interview Survey.

PubMed

Wang, Yueyan; Ponce, Ninez A; Wang, Pan; Opsomer, Jean D; Yu, Hongjian

2015-12-01

We propose a method to meet challenges in generating health estimates for granular geographic areas in which the survey sample size is extremely small. Our generalized linear mixed model predicts health outcomes using both individual-level and neighborhood-level predictors. The model's feature of nonparametric smoothing function on neighborhood-level variables better captures the association between neighborhood environment and the outcome. Using 2011 to 2012 data from the California Health Interview Survey, we demonstrate an empirical application of this method to estimate the fraction of residents without health insurance for Zip Code Tabulation Areas (ZCTAs). Our method generated stable estimates of uninsurance for 1519 of 1765 ZCTAs (86%) in California. For some areas with great socioeconomic diversity across adjacent neighborhoods, such as Los Angeles County, the modeled uninsured estimates revealed much heterogeneity among geographically adjacent ZCTAs. The proposed method can increase the value of health surveys by providing modeled estimates for health data at a granular geographic level. It can account for variations in health outcomes at the neighborhood level as a result of both socioeconomic characteristics and geographic locations.
Unitarity restoring graviton radiation in the collapse regime of gravitational scattering

NASA Astrophysics Data System (ADS)

Ciafaloni, Marcello; Colferai, Dimitri

2017-12-01

We investigate graviton radiation in gravitational scattering at small impact parameters b b , so as to suggest a possible completion of the unitarity sum. In fact, such energy radiation at large distances turns out to compensate and to gradually reduce to nothing the amount of energy E' being trapped at small-b 's, by thus avoiding the quantum tunneling suppression of the elastic scattering and suggesting a unitary evolution. We finally look at the coherent radiation sample so obtained and we find that, by energy conservation, it develops an exponential frequency damping corresponding to a "quasitemperature" of order ℏ/R , which is naturally related to a Hawking radiation and is suggestive of a black-hole signal at quantum level.
Techniques For Measuring Absorption Coefficients In Crystalline Materials

NASA Astrophysics Data System (ADS)

Klein, Philipp H.

1981-10-01

Absorption coefficients smaller than 0.001 cm-1 can, with more or less difficulty, be measured by several techniques. With diligence, all methods can be refined to permit measurement of absorption coefficients as small as 0.00001 cm-1. Spectral data are most readily obtained by transmission (spectrophotometric) methods, using multiple internal reflection to increase effective sample length. Emissivity measurements, requiring extreme care in the elimination of detector noise and stray light, nevertheless afford the most accessible spectral data in the 0.0001 to 0.00001 cm-1 range. Single-wavelength informa-tion is most readily obtained with modifications of laser calorimetry. Thermo-couple detection of energy absorbed from a laser beam is convenient, but involves dc amplification techniques and is susceptible to stray-light problems. Photoacoustic detection, using ac methods, tends to diminish errors of these types, but at some expense in experimental complexity. Laser calorimetry has been used for measurements of absorption coefficients as small as 0.000003 cm-1. Both transmission and calorimetric data, taken as functions of intensity, have been used for measurement of nonlinear absorption coefficients.
Static and dynamic bending has minor effects on xylem hydraulics of conifer branches (Picea abies, Pinus sylvestris)

PubMed Central

Mayr, Stefan; Bertel, Clara; Dämon, Birgit; Beikircher, Barbara

2014-01-01

The xylem hydraulic efficiency and safety is usually measured on mechanically unstressed samples, although trees may be exposed to combined hydraulic and mechanical stress in the field. We analysed changes in hydraulic conductivity and vulnerability to drought-induced embolism during static bending of Picea abies and Pinus sylvestris branches as well as the effect of dynamic bending on the vulnerability. We hypothesized this mechanical stress to substantially impair xylem hydraulics. Intense static bending caused an only small decrease in hydraulic conductance (−19.5 ± 2.4% in P. abies) but no shift in vulnerability thresholds. Dynamic bending caused a 0.4 and 0.8 MPa decrease of the water potential at 50 and 88% loss of conductivity in P. sylvestris, but did not affect vulnerability thresholds in P. abies. With respect to applied extreme bending radii, effects on plant hydraulics were surprisingly small and are thus probably of minor eco-physiological importance. More importantly, results indicate that available xylem hydraulic analyses (of conifers) sufficiently reflect plant hydraulics under field conditions. PMID:24697679

Microfluidic approaches to malaria detection

PubMed Central

Gascoyne, Peter; Satayavivad, Jutamaad; Ruchirawat, Mathuros

2009-01-01

Microfluidic systems are under development to address a variety of medical problems. Key advantages of micrototal analysis systems based on microfluidic technology are the promise of small size and the integration of sample handling and measurement functions within a single, automated device having low mass-production costs. Here, we review the spectrum of methods currently used to detect malaria, consider their advantages and disadvantages, and discuss their adaptability towards integration into small, automated micro total analysis systems. Molecular amplification methods emerge as leading candidates for chip-based systems because they offer extremely high sensitivity, the ability to recognize malaria species and strain, and they will be adaptable to the detection of new genotypic signatures that will emerge from current genomic-based research of the disease. Current approaches to the development of chip-based molecular amplification are considered with special emphasis on flow-through PCR, and we present for the first time the method of malaria specimen preparation by dielectrophoretic field-flow-fractionation. Although many challenges must be addressed to realize a micrototal analysis system for malaria diagnosis, it is concluded that the potential benefits of the approach are well worth pursuing. PMID:14744562
Statistic analysis of annual total ozone extremes for the period 1964-1988

NASA Technical Reports Server (NTRS)

Krzyscin, Janusz W.

1994-01-01

Annual extremes of total column amount of ozone (in the period 1964-1988) from a network of 29 Dobson stations have been examined using the extreme value analysis. The extremes have been calculated as the highest deviation of daily mean total ozone from its long-term monthly mean, normalized by the monthly standard deviations. The extremes have been selected from the direct-Sun total ozone observations only. The extremes resulting from abrupt changes in ozone (day to day changes greater than 20 percent) have not been considered. The ordered extremes (maxima in ascending way, minima in descending way) have been fitted to one of three forms of the Fisher-Tippet extreme value distribution by the nonlinear least square method (Levenberg-Marguard method). We have found that the ordered extremes from a majority of Dobson stations lie close to Fisher-Tippet type III. The extreme value analysis of the composite annual extremes (combined from averages of the annual extremes selected at individual stations) has shown that the composite maxima are fitted by the Fisher-Tippet type III and the composite minima by the Fisher-Tippet type I. The difference between the Fisher-Tippet types of the composite extremes seems to be related to the ozone downward trend. Extreme value prognoses for the period 1964-2014 (derived from the data taken at: all analyzed stations, the North American, and the European stations) have revealed that the prognostic extremes are close to the largest annual extremes in the period 1964-1988 and there are only small regional differences in the prognoses.
Preliminary Evaluation of a Social Skills Training and Facilitated Play Early Intervention Programme for Extremely Shy Young Children in China

ERIC Educational Resources Information Center

Li, Yan; Coplan, Robert J.; Wang, Yuemin; Yin, Jingtong; Zhu, Jingjing; Gao, Zhuqing; Li, Linhui

2016-01-01

The goal of this study was to provide a preliminary evaluation of a social skills and facilitated play early intervention programme to promote social interaction, prosocial behaviours and socio-communicative skills among young extremely shy children in China. Participants were a sample of n = 16 extremely shy young children attending kindergarten…
From ratites to rats: the size of fleshy fruits shapes species' distributions and continental rainforest assembly

PubMed Central

Rossetto, Maurizio; Kooyman, Robert; Yap, Jia-Yee S.; Laffan, Shawn W.

2015-01-01

Seed dispersal is a key process in plant spatial dynamics. However, consistently applicable generalizations about dispersal across scales are mostly absent because of the constraints on measuring propagule dispersal distances for many species. Here, we focus on fleshy-fruited taxa, specifically taxa with large fleshy fruits and their dispersers across an entire continental rainforest biome. We compare species-level results of whole-chloroplast DNA analyses in sister taxa with large and small fruits, to regional plot-based samples (310 plots), and whole-continent patterns for the distribution of woody species with either large (more than 30 mm) or smaller fleshy fruits (1093 taxa). The pairwise genomic comparison found higher genetic distances between populations and between regions in the large-fruited species (Endiandra globosa), but higher overall diversity within the small-fruited species (Endiandra discolor). Floristic comparisons among plots confirmed lower numbers of large-fruited species in areas where more extreme rainforest contraction occurred, and re-colonization by small-fruited species readily dispersed by the available fauna. Species' distribution patterns showed that larger-fruited species had smaller geographical ranges than smaller-fruited species and locations with stable refugia (and high endemism) aligned with concentrations of large fleshy-fruited taxa, making them a potentially valuable conservation-planning indicator. PMID:26645199
From ratites to rats: the size of fleshy fruits shapes species' distributions and continental rainforest assembly.

PubMed

Rossetto, Maurizio; Kooyman, Robert; Yap, Jia-Yee S; Laffan, Shawn W

2015-12-07

Seed dispersal is a key process in plant spatial dynamics. However, consistently applicable generalizations about dispersal across scales are mostly absent because of the constraints on measuring propagule dispersal distances for many species. Here, we focus on fleshy-fruited taxa, specifically taxa with large fleshy fruits and their dispersers across an entire continental rainforest biome. We compare species-level results of whole-chloroplast DNA analyses in sister taxa with large and small fruits, to regional plot-based samples (310 plots), and whole-continent patterns for the distribution of woody species with either large (more than 30 mm) or smaller fleshy fruits (1093 taxa). The pairwise genomic comparison found higher genetic distances between populations and between regions in the large-fruited species (Endiandra globosa), but higher overall diversity within the small-fruited species (Endiandra discolor). Floristic comparisons among plots confirmed lower numbers of large-fruited species in areas where more extreme rainforest contraction occurred, and re-colonization by small-fruited species readily dispersed by the available fauna. Species' distribution patterns showed that larger-fruited species had smaller geographical ranges than smaller-fruited species and locations with stable refugia (and high endemism) aligned with concentrations of large fleshy-fruited taxa, making them a potentially valuable conservation-planning indicator. © 2015 The Author(s).
Gold nanoparticle incorporated inverse opal photonic crystal capillaries for optofluidic surface enhanced Raman spectroscopy.

PubMed

Zhao, Xiangwei; Xue, Jiangyang; Mu, Zhongde; Huang, Yin; Lu, Meng; Gu, Zhongze

2015-10-15

Novel transducers are needed for point of care testing (POCT) devices which aim at facile, sensitive and quick acquisition of health related information. Recent advances in optofluidics offer tremendous opportunities for biological/chemical analysis using extremely small sample volumes. This paper demonstrates nanostructured capillary tubes for surface enhanced Raman spectroscopy (SERS) analysis in a flow-through fashion. The capillary tube integrates the SERS sensor and the nanofluidic structure to synergistically offer sample delivery and analysis functions. Inside the capillary tube, inverse opal photonic crystal (IO PhC) was fabricated using the co-assembly approach to form nanoscale liquid pathways. In the nano-voids of the IO PhC, gold nanoparticles were in situ synthesized and functioned as the SERS hotspots. The advantages of the flow-through SERS sensor are multifold. The capillary effect facilities the sample delivery process, the nanofluidic channels boosts the interaction of analyte and gold nanoparticles, and the PhC structure strengthens the optical field near the SERS hotspots and results in enhanced SERS signals from analytes. As an exemplary demonstration, the sensor was used to measure creatinein spiked in artificial urine samples with detection limit of 0.9 mg/dL. Copyright © 2015 Elsevier B.V. All rights reserved.
Sample Handling in Extreme Environments

NASA Technical Reports Server (NTRS)

Avellar, Louisa; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph

2013-01-01

Harsh environments, such as that on Venus, preclude the use of existing equipment for functions that involve interaction with the environment. The operating limitations of current high temperature electronics are well below the actual temperature and pressure found on Venus (460 deg C and 92 atm), so proposed lander configurations typically include a pressure vessel where the science instruments are kept at Earth-like temperature and pressure (25 deg C and 1 atm). The purpose of this project was to develop and demonstrate a method for sample transfer from an external drill to internal science instruments for a lander on Venus. The initial concepts were string and pneumatically driven systems; and the latter system was selected for its ability to deliver samples at very high speed. The pneumatic system was conceived to be driven by the pressure difference between the Venusian atmosphere and the inside of the lander. The pneumatic transfer of a small capsule was demonstrated, and velocity data was collected from the lab experiment. The sample transfer system was modeled using CAD software and prototyped using 3D printing. General structural and thermal analyses were performed to approximate the proposed system's mass and effects on the temperature and pressure inside of the lander. Additionally, a sampler breadboard for use on Titan was tested and functionality problems were resolved.
Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

PubMed

Shrivas, Kamlesh; Wu, Hui-Fen

2007-11-02

A simple and rapid sample cleanup and preconcentration method for the quantitative determination of caffeine in one drop of beverages and foods by gas chromatography/mass spectrometry (GC/MS) has been proposed using drop-to-drop solvent microextraction (DDSME). The best optimum experimental conditions for DDSME were: chloroform as the extraction solvent, 5 min extraction time, 0.5 microL exposure volume of the extraction phase and no salt addition at room temperature. The optimized methodology exhibited good linearity between 0.05 and 5.0 microg/mL with correlation coefficient of 0.980. The relative standard deviation (RSD) and limits of detection (LOD) of the DDSME/GC/MS method were 4.4% and 4.0 ng/mL, respectively. Relative recovery of caffeine in beverages and foods were found to be 96.6-101%, which showing good reliability of this method. This DDSME excludes the major disadvantages of conventional method of caffeine extraction, like large amount of organic solvent and sample consumption and long sample pre-treatment process. So, this approach proves that the DDSME/GC/MS technique can be applied as a simple, fast and feasible diagnosis tool for environmental, food and biological application for extremely small amount of real sample analysis.
Microparticle sampling by electrowetting-actuated droplet sweeping.

PubMed

Zhao, Yuejun; Cho, Sung Kwon

2006-01-01

This paper describes a new microparticle sampler where particles can be efficiently swept from a solid surface and sampled into a liquid medium using moving droplets actuated by the electrowetting principle. We successfully demonstrate that super hydrophilic (2 microm and 7.9 microm diameter glass beads of about 14 degrees contact angle), intermediate hydrophilic (7.5 microm diameter polystyrene beads of about 70 degrees contact angle), and super hydrophobic (7.9 microm diameter Teflon-coated glass beads and 3 microm size PTFE particles of over 110 degrees contact angles) particles on a solid surface are picked up by electrowetting-actuated moving droplets. For the glass beads as well as the polystyrene beads, the sampling efficiencies are over 93%, in particular over 98% for the 7.9 microm glass beads. For the PTFE particles, however, the sampling efficiency is measured at around 70%, relatively lower than that of the glass and polystyrene beads. This is due mainly to the non-uniformity in particle size and the particle hydrophobicity. In this case, the collected particles staying (adsorbing) on the air-to-water interface hinder the droplet from advancing. This particle sampler requires an extremely small amount of liquid volume (about 500 nanoliters) and will thus be highly compatible and easily integrated with lab-on-a-chip systems for follow-up biological/chemical analyses.
Challenges to a molecular approach to prey identification in the Burmese python, Python molurus bivittatus

USGS Publications Warehouse

Falk, Bryan; Reed, Robert N.

2015-01-01

Molecular approaches to prey identification are increasingly useful in elucidating predator–prey relationships, and we aimed to investigate the feasibility of these methods to document the species identities of prey consumed by invasive Burmese pythons in Florida. We were particularly interested in the diet of young snakes, because visual identification of prey from this size class has proven difficult. We successfully extracted DNA from the gastrointestinal contents of 43 young pythons, as well as from several control samples, and attempted amplification of DNA mini-barcodes, a 130-bp region of COX1. Using a PNA clamp to exclude python DNA, we found that prey DNA was not present in sufficient quality for amplification of this locus in 86% of our samples. All samples from the GI tracts of young pythons contained only hair, and the six samples we were able to identify to species were hispid cotton rats. This suggests that young Burmese pythons prey predominantly on small mammals and that prey diversity among snakes of this size class is low. We discuss prolonged gastrointestinal transit times and extreme gastric breakdown as possible causes of DNA degradation that limit the success of a molecular approach to prey identification in Burmese pythons
Response Identification in the Extremely Low Frequency Region of an Electret Condenser Microphone

PubMed Central

Jeng, Yih-Nen; Yang, Tzung-Ming; Lee, Shang-Yin

2011-01-01

This study shows that a small electret condenser microphone connected to a notebook or a personal computer (PC) has a prominent response in the extremely low frequency region in a specific environment. It confines most acoustic waves within a tiny air cell as follows. The air cell is constructed by drilling a small hole in a digital versatile disk (DVD) plate. A small speaker and an electret condenser microphone are attached to the two sides of the hole. Thus, the acoustic energy emitted by the speaker and reaching the microphone is strong enough to actuate the diaphragm of the latter. The experiments showed that, once small air leakages are allowed on the margin of the speaker, the microphone captured the signal in the range of 0.5 to 20 Hz. Moreover, by removing the plastic cover of the microphone and attaching the microphone head to the vibration surface, the low frequency signal can be effectively captured too. Two examples are included to show the convenience of applying the microphone to pick up the low frequency vibration information of practical systems. PMID:22346594
Response identification in the extremely low frequency region of an electret condenser microphone.

PubMed

Jeng, Yih-Nen; Yang, Tzung-Ming; Lee, Shang-Yin

2011-01-01

This study shows that a small electret condenser microphone connected to a notebook or a personal computer (PC) has a prominent response in the extremely low frequency region in a specific environment. It confines most acoustic waves within a tiny air cell as follows. The air cell is constructed by drilling a small hole in a digital versatile disk (DVD) plate. A small speaker and an electret condenser microphone are attached to the two sides of the hole. Thus, the acoustic energy emitted by the speaker and reaching the microphone is strong enough to actuate the diaphragm of the latter. The experiments showed that, once small air leakages are allowed on the margin of the speaker, the microphone captured the signal in the range of 0.5 to 20 Hz. Moreover, by removing the plastic cover of the microphone and attaching the microphone head to the vibration surface, the low frequency signal can be effectively captured too. Two examples are included to show the convenience of applying the microphone to pick up the low frequency vibration information of practical systems.
Development of a miniature Stirling cryocooler for LWIR small satellite applications

NASA Astrophysics Data System (ADS)

Kirkconnell, C. S.; Hon, R. C.; Perella, M. D.; Crittenden, T. M.; Ghiaasiaan, S. M.

2017-05-01

The optimum small satellite (SmallSat) cryocooler system must be extremely compact and lightweight, achieved in this paper by operating a linear cryocooler at a frequency of approximately 300 Hz. Operation at this frequency, which is well in excess of the 100-150 Hz reported in recent papers on related efforts, requires an evolution beyond the traditional Oxford-class, flexure-based methods of setting the mechanical resonance. A novel approach that optimizes the electromagnetic design and the mechanical design together to simultaneously achieve the required dynamic and thermodynamic performances is described. Since highly miniaturized pulse tube coolers are fundamentally ill-suited for the sub-80K temperature range of interest because the boundary layer losses inside the pulse tube become dominant at the associated very small pulse tube size, a moving displacer Stirling cryocooler architecture is used. Compact compressor mechanisms developed on a previous program are reused for this design, and they have been adapted to yield an extremely compact Stirling warm end motor mechanism. Supporting thermodynamic and electromagnetic analysis results are reported.
A New Sample of Cool Subdwarfs from SDSS: Properties and Kinematics

NASA Astrophysics Data System (ADS)

Savcheva, Antonia; West, Andrew A.; Bochanski, John J.

2014-06-01

We present a new sample of M subdwarfs compiled from the 7th data re- lease of the Sloan Digital Sky Survey. With 3517 new subdwarfs, this new sample significantly increases the number the existing sample of low-mass subdwarfs. This catalog includes unprecedentedly large numbers of extreme and ultra sudwarfs. Here, we present the catalog and the statistical analysis we perform. Subdwarf template spectra are derived. We show color-color and reduced proper motion diagrams of the three metallicity classes, which are shown to separate from the disk dwarf population. The extreme and ultra subdwarfs are seen at larger values of reduced proper motion as expected for more dynamically heated populations. We determine 3D kinematics for all of the stars with proper motions. The color-magnitude diagrams show a clear separation of the three metallicity classes with the ultra and extreme subdwarfs being significantly closer to the main sequence than the ordinary subdwarfs. All subdwarfs lie below and to the blue of the main sequence. Based on the average (U, V, W ) velocities and their dispersions, the extreme and ultra subdwarfs likely belong to the Galactic halo, while the ordinary subdwarfs are likely part of the old Galactic (or thick) disk. An extensive activity analy- sis of subdwarfs is performed using chromospheric Hα emission and 208 active subdwarfs are found. We show that while the activity fraction of subdwarfs rises with spectral class and levels off at the latest spectral classes, consistent with the behavior of M dwarfs, the extreme and ultra subdwarfs are basically flat.
Utility of Cytospin and Cell block Technology in Evaluation of Body Fluids and Urine Samples: A Comparative Study.

PubMed

Qamar, Irmeen; Rehman, Suhailur; Mehdi, Ghazala; Maheshwari, Veena; Ansari, Hena A; Chauhan, Sunanda

2018-01-01

Cytologic examination of body fluids commonly involves the use of direct or sediment smears, cytocentrifuge preparations, membrane filter preparations, or cell block sections. Cytospin and cell block techniques are extremely useful in improving cell yield of thin serous effusions and urine samples, and ensure high diagnostic efficacy. We studied cytospin preparations and cell block sections prepared from 180 samples of body fluids and urine samples to compare the relative efficiency of cell retrieval, preservation of cell morphology, ease of application of special stains, and diagnostic efficacy. Samples were collected and processed to prepare cytospin smears and cell block sections. We observed that overall, cell yield and preservation of individual cell morphology were better in cytospin preparations as compared to cell blocks, while preservation of architectural pattern was better in cell block sections. The number of suspicious cases also decreased on cell block sections, with increased detection of malignancy. It was difficult to prepare cell blocks from urine samples due to low cellularity. Cytospin technology is a quick, efficient, and cost-effective method of increasing cell yield in hypocellular samples, with better preservation of cell morphology. Cell blocks are better prepared from high cellularity fluids; however, tissue architecture is better studied, with improved rate of diagnosis and decrease in ambiguous results. Numerous sections can be prepared from a small amount of material. Special stains and immunochemical stains can be easily applied to cell blocks. It also provides a source of archival material.
The interactive effects of estrogen and progesterone on changes in emotional eating across the menstrual cycle.

PubMed

Klump, Kelly L; Keel, Pamela K; Racine, Sarah E; Burt, S Alexandra; Burt, Alexandra S; Neale, Michael; Sisk, Cheryl L; Boker, Steven; Hu, Jean Yueqin

2013-02-01

Studies suggest that within-person changes in estrogen and progesterone predict changes in binge eating across the menstrual cycle. However, samples have been extremely small (maximum N = 9), and analyses have not examined the interactive effects of hormones that are critical for changes in food intake in animals. The aims of the current study were to examine ovarian hormone interactions in the prediction of within-subject changes in emotional eating in the largest sample of women to date (N = 196). Participants provided daily ratings of emotional eating and saliva samples for hormone measurement for 45 consecutive days. Results confirmed that changes in ovarian hormones predict changes in emotional eating across the menstrual cycle, with a significant estradiol × progesterone interaction. Emotional eating scores were highest during the midluteal phase, when progesterone peaks and estradiol demonstrates a secondary peak. Findings extend previous work by highlighting significant interactions between estrogen and progesterone that explain midluteal increases in emotional eating. Future work should explore mechanisms (e.g., gene-hormone interactions) that contribute to both within- and between-subjects differences in emotional eating. 2013 APA, all rights reserved
Impact of climate variability on ichthyoplankton communities: An example of a small temperate estuary

NASA Astrophysics Data System (ADS)

Primo, Ana Lígia; Azeiteiro, Ulisses Miranda; Marques, Sónia Cotrim; Pardal, Miguel Ângelo

2011-03-01

Recent variations in the precipitation regime across southern Europe have led to changes in river fluxes and salinity gradients affecting biological communities in most rivers and estuaries. A sampling programme was developed in the Mondego estuary, Portugal, from January 2003 to December 2008 at five distinct sampling stations to evaluate spatial, seasonal and inter-annual distributions of fish larvae. Gobiidae was the most abundant family representing 80% of total catch and Pomatoschistus spp. was the most important taxon. The fish larval community presented a clear seasonality with higher abundances and diversities during spring and summer seasons. Multivariate analysis reinforced differences among seasons but not between years or sampling stations. The taxa Atherina presbyter, Solea solea, Syngnathus abaster, Crystallogobius linearis and Platichthys flesus were more abundant during spring/summer period while Ammodytes tobianus, Callionymus sp., Echiichthys vipera and Liza ramada were more abundant in autumn/winter. Temperature, chlorophyll a and river flow were the main variation drivers observed although extreme drought events (year 2005) seemed not to affect ichthyoplankton community structure. Main changes were related to a spatial displacement of salinity gradient along the estuarine system which produced changes in marine species distribution.
Particle size and surface area effects on the thin-pulse shock initiation of Diaminoazoxyfurazan (DAAF)

NASA Astrophysics Data System (ADS)

Burritt, Rosemary; Francois, Elizabeth; Windler, Gary; Chavez, David

2017-06-01

Diaminoazoxyfurazan (DAAF) has many of the safety characteristics of an insensitive high explosive (IHE): it is extremely insensitive to impact and friction and is comparable to triaminotrinitrobezene (TATB) in this way. Conversely, it demonstrates many performance characteristics of a Conventional High Explosive (CHE). DAAF has a small failure diameter of about 1.25 mm and can be sensitive to shock under the right conditions. Large particle sized DAAF will not initiate in a typical exploding foil initiator (EFI) configuration but smaller particle sizes will. Large particle sized DAAF, of 40 μm, was crash precipitated and ball milled into six distinct samples and pressed into pellets with a density of 1.60 g/cc (91% TMD). To investigate the effect of particle size and surface area on the direct initiation on DAAF multiple threshold tests were preformed on each sample of DAAF in different EFI configurations, which varied in flyer thickness and/or bridge size. Comparative tests were performed examining threshold voltage and correlated to Photon Doppler Velocimetry (PDV) results. The samples with larger particle sizes and surface area required more energy to initiate while the smaller particle sizes required less energy and could be initiated with smaller diameter flyers.
Entropy, extremality, euclidean variations, and the equations of motion

NASA Astrophysics Data System (ADS)

Dong, Xi; Lewkowycz, Aitor

2018-01-01

We study the Euclidean gravitational path integral computing the Rényi entropy and analyze its behavior under small variations. We argue that, in Einstein gravity, the extremality condition can be understood from the variational principle at the level of the action, without having to solve explicitly the equations of motion. This set-up is then generalized to arbitrary theories of gravity, where we show that the respective entanglement entropy functional needs to be extremized. We also extend this result to all orders in Newton's constant G N , providing a derivation of quantum extremality. Understanding quantum extremality for mixtures of states provides a generalization of the dual of the boundary modular Hamiltonian which is given by the bulk modular Hamiltonian plus the area operator, evaluated on the so-called modular extremal surface. This gives a bulk prescription for computing the relative entropies to all orders in G N . We also comment on how these ideas can be used to derive an integrated version of the equations of motion, linearized around arbitrary states.
A Framework to Understand Extreme Space Weather Event Probability.

PubMed

Jonas, Seth; Fronczyk, Kassandra; Pratt, Lucas M

2018-03-12

An extreme space weather event has the potential to disrupt or damage infrastructure systems and technologies that many societies rely on for economic and social well-being. Space weather events occur regularly, but extreme events are less frequent, with a small number of historical examples over the last 160 years. During the past decade, published works have (1) examined the physical characteristics of the extreme historical events and (2) discussed the probability or return rate of select extreme geomagnetic disturbances, including the 1859 Carrington event. Here we present initial findings on a unified framework approach to visualize space weather event probability, using a Bayesian model average, in the context of historical extreme events. We present disturbance storm time (Dst) probability (a proxy for geomagnetic disturbance intensity) across multiple return periods and discuss parameters of interest to policymakers and planners in the context of past extreme space weather events. We discuss the current state of these analyses, their utility to policymakers and planners, the current limitations when compared to other hazards, and several gaps that need to be filled to enhance space weather risk assessments. © 2018 Society for Risk Analysis.

A large, benign prostatic cyst presented with an extremely high serum prostate-specific antigen level.

PubMed

Chen, Han-Kuang; Pemberton, Richard

2016-01-08

We report a case of a patient who presented with an extremely high serum prostate specific antigen (PSA) level and underwent radical prostatectomy for presumed prostate cancer. Surprisingly, the whole mount prostatectomy specimen showed only small volume, organ-confined prostate adenocarcinoma and a large, benign intraprostatic cyst, which was thought to be responsible for the PSA elevation. 2016 BMJ Publishing Group Ltd.
Evidence of population resistance to extreme low flows in a fluvial-dependent fish species

USGS Publications Warehouse

Katz, Rachel A.; Freeman, Mary C.

2015-01-01

Extreme low streamflows are natural disturbances to aquatic populations. Species in naturally intermittent streams display adaptations that enhance persistence during extreme events; however, the fate of populations in perennial streams during unprecedented low-flow periods is not well-understood. Biota requiring swift-flowing habitats may be especially vulnerable to flow reductions. We estimated the abundance and local survival of a native fluvial-dependent fish species (Etheostoma inscriptum) across 5 years encompassing historic low flows in a sixth-order southeastern USA perennial river. Based on capturemark-recapture data, the study shoal may have acted as a refuge during severe drought, with increased young-of-the-year (YOY) recruitment and occasionally high adult immigration. Contrary to expectations, summer and autumn survival rates (30 days) were not strongly depressed during low-flow periods, despite 25%-80% reductions in monthly discharge. Instead, YOY survival increased with lower minimum discharge and in response to small rain events that increased low-flow variability. Age-1+ fish showed the opposite pattern, with survival decreasing in response to increasing low-flow variability. Results from this population dynamics study of a small fish in a perennial river suggest that fluvial-dependent species can be resistant to extreme flow reductions through enhanced YOY recruitment and high survival
Micromechanical calorimetric sensor

DOEpatents

Thundat, Thomas G.; Doktycz, Mitchel J.

2000-01-01

A calorimeter sensor apparatus is developed utilizing microcantilevered spring elements for detecting thermal changes within a sample containing biomolecules which undergo chemical and biochemical reactions. The spring element includes a bimaterial layer of chemicals on a coated region on at least one surface of the microcantilever. The chemicals generate a differential thermal stress across the surface upon reaction of the chemicals with an analyte or biomolecules within the sample due to the heat of chemical reactions in the sample placed on the coated region. The thermal stress across the spring element surface creates mechanical bending of the microcantilever. The spring element has a low thermal mass to allow detection and measuring of heat transfers associated with chemical and biochemical reactions within a sample placed on or near the coated region. A second surface may have a different material, or the second surface and body of microcantilever may be of an inert composition. The differential thermal stress between the surfaces of the microcantilever create bending of the cantilever. Deflections of the cantilever are detected by a variety of detection techniques. The microcantilever may be approximately 1 to 200 .mu.m long, approximately 1 to 50 .mu.m wide, and approximately 0.3 to 3.0 .mu.m thick. A sensitivity for detection of deflections is in the range of 0.01 nanometers. The microcantilever is extremely sensitive to thermal changes in samples as small as 30 microliters.
Identification and Correction of Sample Mix-Ups in Expression Genetic Data: A Case Study

PubMed Central

Broman, Karl W.; Keller, Mark P.; Broman, Aimee Teo; Kendziorski, Christina; Yandell, Brian S.; Sen, Śaunak; Attie, Alan D.

2015-01-01

In a mouse intercross with more than 500 animals and genome-wide gene expression data on six tissues, we identified a high proportion (18%) of sample mix-ups in the genotype data. Local expression quantitative trait loci (eQTL; genetic loci influencing gene expression) with extremely large effect were used to form a classifier to predict an individual’s eQTL genotype based on expression data alone. By considering multiple eQTL and their related transcripts, we identified numerous individuals whose predicted eQTL genotypes (based on their expression data) did not match their observed genotypes, and then went on to identify other individuals whose genotypes did match the predicted eQTL genotypes. The concordance of predictions across six tissues indicated that the problem was due to mix-ups in the genotypes (although we further identified a small number of sample mix-ups in each of the six panels of gene expression microarrays). Consideration of the plate positions of the DNA samples indicated a number of off-by-one and off-by-two errors, likely the result of pipetting errors. Such sample mix-ups can be a problem in any genetic study, but eQTL data allow us to identify, and even correct, such problems. Our methods have been implemented in an R package, R/lineup. PMID:26290572
Identification and Correction of Sample Mix-Ups in Expression Genetic Data: A Case Study.

PubMed

Broman, Karl W; Keller, Mark P; Broman, Aimee Teo; Kendziorski, Christina; Yandell, Brian S; Sen, Śaunak; Attie, Alan D

2015-08-19

In a mouse intercross with more than 500 animals and genome-wide gene expression data on six tissues, we identified a high proportion (18%) of sample mix-ups in the genotype data. Local expression quantitative trait loci (eQTL; genetic loci influencing gene expression) with extremely large effect were used to form a classifier to predict an individual's eQTL genotype based on expression data alone. By considering multiple eQTL and their related transcripts, we identified numerous individuals whose predicted eQTL genotypes (based on their expression data) did not match their observed genotypes, and then went on to identify other individuals whose genotypes did match the predicted eQTL genotypes. The concordance of predictions across six tissues indicated that the problem was due to mix-ups in the genotypes (although we further identified a small number of sample mix-ups in each of the six panels of gene expression microarrays). Consideration of the plate positions of the DNA samples indicated a number of off-by-one and off-by-two errors, likely the result of pipetting errors. Such sample mix-ups can be a problem in any genetic study, but eQTL data allow us to identify, and even correct, such problems. Our methods have been implemented in an R package, R/lineup. Copyright © 2015 Broman et al.
Maintaining Small Business Support in Times of Increased Army National Guard Utilization An Impending Crisis

DTIC Science & Technology

2006-02-13

business clientele, additional costs to hire a manager or replacement workers, complete loss of family income, and in extreme situations, bankruptcy, are...USAWC STRATEGY RESEARCH PROJECT MAINTAINING SMALL BUSINESS SUPPORT IN TIMES OF INCREASED ARMY NATIONAL GUARD UTILIZATION: AN IMPENDING CRISIS by...00-00-2005 to 00-00-2006 4. TITLE AND SUBTITLE Maintaining Small Business Support in Times of Increased Army National Guard Utilization An
Evolution caused by extreme events.

PubMed

Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna

2017-06-19

Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).
CARBON ABUNDANCES FOR RED GIANTS IN THE DRACO DWARF SPHEROIDAL GALAXY

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

Shetrone, Matthew D.; Stanford, Laura M.; Smith, Graeme H.

2013-05-15

Measurements of [C/Fe], [Ca/H], and [Fe/H] have been derived from Keck I LRISb spectra of 35 giants in the Draco dwarf spheroidal galaxy. The iron abundances are derived by a spectrum synthesis modeling of the wavelength region from 4850 to 5375 A, while calcium and carbon abundances are obtained by fitting the Ca II H and K lines and the CH G band, respectively. A range in metallicity of -2.9 {<=} [Fe/H] {<=} -1.6 is found within the giants sampled, with a good correlation between [Fe/H] and [Ca/H]. The great majority of stars in the sample would be classified asmore » having weak absorption in the {lambda}3883 CN band, with only a small scatter in band strengths at a given luminosity on the red giant branch. In this sense the behavior of CN among the Draco giants is consistent with the predominantly weak CN bands found among red giants in globular clusters of metallicity [Fe/H] < -1.8. Over half of the giants in the Draco sample have [Fe/H] > -2.25, and among these there is a trend for the [C/Fe] abundance to decrease with increasing luminosity on the red giant branch. This is a phenomenon that is also seen among both field and globular cluster giants of the Galactic halo, where it has been interpreted as a consequence of deep mixing of material between the base of the convective envelope and the outer limits of the hydrogen-burning shell. However, among the six Draco giants observed that turn out to have metallicities -2.65 < [Fe/H] < -2.25 there is no such trend seen in the carbon abundance. This may be due to small sample statistics or primordial inhomogeneities in carbon abundance among the most metal-poor Draco stars. We identify a potential carbon-rich extremely metal-poor star in our sample. This candidate will require follow-up observations for confirmation.« less
The Gulliver sample return mission to Deimos

NASA Astrophysics Data System (ADS)

Britt, D. T.; Robinson, M.; Gulliver Team

The Martian moon Deimos presents a unique opportunity for a sample return mission. Deimos is spectrally analogous to type D asteroids, which are thought to be composed of highly primitive carbonaceous material that originated in the outer asteroid belt. It also is in orbit around Mars and has been accumulating material ejected from the Martian surface ever since the earliest periods of Martian history, over 4.4 Gyrs ago. There are a number of factors that make sample return from Deimos extremely attractive. It is Better: Deimos is a repository for two kinds of extremely significant and scientifically exciting ancient samples: (1) Primitive spectral D-type material that may have accreted in the outer asteroid belt and Trojan swarm. This material samples the composition of solar nebula well outside the zone of terrestrial planets and provides a direct sample of primitive material so common past 3 AU but so uncommon in the meteorite collection. (2) Ancient Mars, which could include the full range of Martian crustal and upper mantle material from the early differentiation and crustal-forming epoch as well as samples from the era of high volatile flux, thick atmosphere, and possible surface water. The Martian material on Deimos would be dominated by ejecta from the ancient crust of Mars, delivered during the Noachian Period of basin-forming impacts and heavy bombardment. It is Closer: Compared to other primitive D-type asteroids, Deimos is by far the most accessible. Because of its orbit around Mars, Deimos is far closer than any other D asteroid. It is Safer: Deimos is also by far the safest small body for sample return yet imaged. It is an order of magnitude less rocky than Eros and the NEAR-Shoemaker mission succeeded in landing on Eros with a spacecraft not designed for landing and proximity maneuvering. Because of Viking imagery we already know a great deal about the surface roughness of Deimos. It is known to be very smooth and have moderate topography and gravitational slopes. It is Easier: Deimos is farther from Mars and smaller than Phobos. This location minimizes the delta-V penalties from entering the Martian gravity well; minimizes the energy requirements for sampling maneuvers; and minimizes Martian tidal effects on S/C operations. After initial processing these samples will be made available as soon as possible to the international cosmochemistry community for detailed analysis. The mission management team includes Lockheed Martin Astronautics (flight system, I&T) and JPL (payload, mission ops, and mission management).
Parametric Sensitivity Analysis of Precipitation at Global and Local Scales in the Community Atmosphere Model CAM5

DOE PAGES

Qian, Yun; Yan, Huiping; Hou, Zhangshuan; ...

2015-04-10

We investigate the sensitivity of precipitation characteristics (mean, extreme and diurnal cycle) to a set of uncertain parameters that influence the qualitative and quantitative behavior of the cloud and aerosol processes in the Community Atmosphere Model (CAM5). We adopt both the Latin hypercube and quasi-Monte Carlo sampling approaches to effectively explore the high-dimensional parameter space and then conduct two large sets of simulations. One set consists of 1100 simulations (cloud ensemble) perturbing 22 parameters related to cloud physics and convection, and the other set consists of 256 simulations (aerosol ensemble) focusing on 16 parameters related to aerosols and cloud microphysics.more » Results show that for the 22 parameters perturbed in the cloud ensemble, the six having the greatest influences on the global mean precipitation are identified, three of which (related to the deep convection scheme) are the primary contributors to the total variance of the phase and amplitude of the precipitation diurnal cycle over land. The extreme precipitation characteristics are sensitive to a fewer number of parameters. The precipitation does not always respond monotonically to parameter change. The influence of individual parameters does not depend on the sampling approaches or concomitant parameters selected. Generally the GLM is able to explain more of the parametric sensitivity of global precipitation than local or regional features. The total explained variance for precipitation is primarily due to contributions from the individual parameters (75-90% in total). The total variance shows a significant seasonal variability in the mid-latitude continental regions, but very small in tropical continental regions.« less
Viability and resistance of lactobacilli isolated from cocoa fermentation to simulated gastrointestinal digestive steps in soy yogurt.

PubMed

Saito, V S T; Dos Santos, T F; Vinderola, C G; Romano, C; Nicoli, J R; Araújo, L S; Costa, M M; Andrioli, J L; Uetanabaro, A P T

2014-02-01

To study the potential probiotic characteristics such as decrease of pH, microbial viability, and tolerance to simulated digestive steps of fermented soy beverage ("soy yogurt") produced with lactobacilli isolated from cocoa fermentation (Lactobacillus fermentum TcUESC01 and Lactobacillus plantarum TcUESC02) during fermentation and refrigerated storage. The sensory acceptance of the yogurts was also tested. Samples of soy yogurt produced with L. fermentum TcUESC01 or L. plantarum TcUESC02 were collected during fermentation (0, 4, 8, and 12 h) and refrigerated storage (1, 9, 18, and 27 d), and submitted to pH and bacterial viability determinations. Tolerance to simulated digestion steps was done with refrigerated storage samples at 9 °C. Simulated digestion was performed in 3 successive steps: exposure to pepsin-HCl solution, bile shock, and simulated small intestinal juice. During storage, a decrease in pH and lactobacillus viability was observed. L. fermentum TcUESC01 showed to be more resistant than L. plantarum TcUESC02 to simulated gastrointestinal digestion. All soy yogurts showed acceptable hedonic scores (greater than 5 in a 9-point hedonic scale ranging from "like extremely" to "dislike extremely") in sensory evaluation for flavor, aroma, color, consistency, and overall impression. L. plantarum TcUESC02 and, especially, L. fermentum TcUESC01 showed potential probiotic characteristics when considering pH, cell viability, and tolerance to simulated digestive steps and did not affect the sensory characteristics when supplemented to soy yogurt during storage. © 2014 Institute of Food Technologists®
Maximum likelihood estimation of correction for dilution bias in simple linear regression using replicates from subjects with extreme first measurements.

PubMed

Berglund, Lars; Garmo, Hans; Lindbäck, Johan; Svärdsudd, Kurt; Zethelius, Björn

2008-09-30

The least-squares estimator of the slope in a simple linear regression model is biased towards zero when the predictor is measured with random error. A corrected slope may be estimated by adding data from a reliability study, which comprises a subset of subjects from the main study. The precision of this corrected slope depends on the design of the reliability study and estimator choice. Previous work has assumed that the reliability study constitutes a random sample from the main study. A more efficient design is to use subjects with extreme values on their first measurement. Previously, we published a variance formula for the corrected slope, when the correction factor is the slope in the regression of the second measurement on the first. In this paper we show that both designs improve by maximum likelihood estimation (MLE). The precision gain is explained by the inclusion of data from all subjects for estimation of the predictor's variance and by the use of the second measurement for estimation of the covariance between response and predictor. The gain of MLE enhances with stronger true relationship between response and predictor and with lower precision in the predictor measurements. We present a real data example on the relationship between fasting insulin, a surrogate marker, and true insulin sensitivity measured by a gold-standard euglycaemic insulin clamp, and simulations, where the behavior of profile-likelihood-based confidence intervals is examined. MLE was shown to be a robust estimator for non-normal distributions and efficient for small sample situations. Copyright (c) 2008 John Wiley & Sons, Ltd.
Recent work on network application layer: MioNet, the virtual workplace for small businesses

NASA Astrophysics Data System (ADS)

Hesselink, Lambertus; Rizal, Dharmarus; Bjornson, Eric; Miller, Brian; Chan, Keith

2005-11-01

Small businesses must be extremely efficient and smartly leverage their resources, suppliers, and partners to successfully compete with larger firms. A successful small business requires a set of companies with interlocking business relationships that are dynamic and needs-based. There has been no software solution that creates a secure and flexible way to efficiently connect small business computer-based employees and partners. In this invited paper, we discuss MioNet, a secure and powerful data management platform which may provide millions of small businesses with a virtual workplace and help them to succeed.
Integrating Near and Mid-Infrared Microspectroscopy with Experimental Petrology

NASA Astrophysics Data System (ADS)

Klima, R. L.; Shank, E.; Chabot, N. L.; Minitti, M. E.

2012-12-01

One of the challenges of interpreting data gathered by remote sensing of planetary surfaces is that many of the samples in our spectral libraries that we use for comparison are necessarily terrestrial. Some contamination is easily recognized, such as alteration to hydrated minerals or contamination by organic material. In some cases the contamination is more subtle, such as when small amounts of ferric iron are present, altering the visible wavelength continuum of nominally ferrous silicates. Measurement of meteorite samples (e.g., 1, 2-5) and lunar samples (e.g. 6, 7) provides critical ground-truth data, but often the amount of samples allocated for study are smaller than can be measured in many labs. Experimentally created samples, as well, often produce only small amounts of powder that are difficult to measure without specially designed spectrometers such as the RELAB. FTIR Microspectroscopy has been investigated as an option for studying very small samples in reflectance, but scattering properties of the sample and the intensity of the illumination can result in extremely low signal spectra (8). Fortunately, a more intense source and modified optics allow significantly more signal in the near-infrared, enabling spectral characterization of diagnostic features even in reflectance. Spot sizes on the order of 50-100um allow individual grains or mounted sample charges to be targeted and measured, as long as the sample is slightly roughened to minimize specular reflectance off of the target. This new capability affords us the opportunity to collect spectra for experimental materials created for understanding igneous and metamorphic processes on other planets. Currently, we are incorporating these techniques with two studies aimed at understanding volcanism and mantle processes on Mercury. In the first study, we are conducting a series of melting experiments to explore the mineral composition of the Northern Volcanic Plains of Mercury. In the second, we are investigating reactions between solid Fe-free silicates and iron sulfide at very low oxygen fugacities. We will present experimental results paired with spectral measurements of the samples for each of the experimental runs and evaluate them in the context of data acquired by the MESSENGER spacecraft's Mercury Atmospheric and Surface Composition Spectrometer Visible and Infrared Spectrograph. References: 1. T. Hiroi et al., EPS 53, 1071 (2001). 2. T. Hiroi et al., Science 293, 2234 (2001). 3. R. G. Mayne et al., MAPS 40, 5174 (2005). 4. T. J. McCoy et al., MAPS 34, 735 (1999). 5. J. M. Sunshine et al., Science 320, 514 (2008). 6. Pieters, et al., Icarus 184, 83 (2006). 7. Isaacson et al., MAPS 46, 228 (2011). 8. Klima and Pieters, JGR 111, 01005 (2006).
Characteristics of a 30-cm thruster operated with small hole accelerator grid ion optics

NASA Technical Reports Server (NTRS)

Vahrenkamp, R. P.

1976-01-01

Small hole accelerator grid ion optical systems have been tested as a possible means of improving 30-cm ion thruster performance. The effects of small hole grids on the critical aspects of thruster operation including discharge chamber performance, doubly-charged ion concentration, effluent beam characteristics, and plasma properties have been evaluated. In general, small hole accelerator grids are beneficial in improving thruster performance while maintaining low double ion ratios. However, extremely small accelerator aperture diameters tend to degrade beam divergence characteristics. A quantitative discussion of these advantages and disadvantages of small hole accelerator grids, as well as resulting variations in thruster operation characteristics, is presented.
Scoresum - A technique for displaying and evaluating multi-element geochemical information, with examples of its use in regional mineral assessment programs

USGS Publications Warehouse

Chaffee, M.A.

1983-01-01

A technique called SCORESUM was developed to display a maximum of multi-element geochemical information on a minimum number of maps for mineral assessment purposes. The technique can be done manually for a small analytical data set or can be done with a computer for a large data set. SCORESUM can be used with highly censored data and can also weight samples so as to minimize the chemical differences of diverse lithologies in different parts of a given study area. The full range of reported analyses for each element of interest in a data set is divided into four categories. Anomaly scores - values of O (background), 1 (weakly anomalous), 2 (moderately anomalous), and 3 (strongly anomalous) - are substituted for all of the analyses falling into each of the four categories. A group of elements based on known or suspected association in altered or mineralized areas is selected for study and the anomaly scores for these elements are summed for each sample site and then plotted on a map. Some of the results of geochemical studies conducted for mineral assessments in two areas are briefly described. The first area, the Mokelumne Wilderness and vicinity, is a relatively small and geologically simple one. The second, the Walker Lake 1?? ?? 2?? quadrangle, is a large area that has extremely complex geology and that contains a number of different mineral deposit environments. These two studies provide examples of how the SCORESUM technique has been used (1) to enhance relatively small but anomalous areas and (2) to delineate and rank areas containing geochemical signatures for specific suites of elements related to certain types of alteration or mineralization. ?? 1983.
Improved Diffuse Fluorescence Flow Cytometer Prototype for High Sensitivity Detection of Rare Circulating Cells In Vivo

NASA Astrophysics Data System (ADS)

Pestana, Noah Benjamin

Accurate quantification of circulating cell populations is important in many areas of pre-clinical and clinical biomedical research, for example, in the study of cancer metastasis or the immune response following tissue and organ transplants. Normally this is done "ex-vivo" by drawing and purifying a small volume of blood and then analyzing it with flow cytometry, hemocytometry or microfludic devices, but the sensitivity of these techniques are poor and the process of handling samples has been shown to affect cell viability and behavior. More recently "in vivo flow cytometry" (IVFC) techniques have been developed where fluorescently-labeled cells flowing in a small blood vessel in the ear or retina are analyzed, but the sensitivity is generally poor due to the small sampling volume. To address this, our group recently developed a method known as "Diffuse Fluorescence Flow Cytometry" (DFFC) that allows detection and counting of rare circulating cells with diffuse photons, offering extremely high single cell counting sensitivity. In this thesis, an improved DFFC prototype was designed and validated. The chief improvements were three-fold, i) improved optical collection efficiency, ii) improved detection electronics, and iii) development of a method to mitigate motion artifacts during in vivo measurements. In combination, these improvements yielded an overall instrument detection sensitivity better than 1 cell/mL in vivo, which is the most sensitive IVFC system reported to date. Second, development and validation of a low-cost microfluidic device reader for analysis of ocular fluids is described. We demonstrate that this device has equivalent or better sensitivity and accuracy compared a fluorescence microscope, but at an order-of-magnitude reduced cost with simplified operation. Future improvements to both instruments are also discussed.
New Candidate Supernova Remnants in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Winkler, P. F.; Lewinter, R.

1992-12-01

We have surveyed six 30(') times 30(') fields in the Small Magellanic Cloud, using the Curtis Schmidt telescope at CTIO with a Thomson CCD, to search for previously undetected supernova remnants (SNRs). Narrow-band images are obtained in lines of [S II] (lambda lambda \\ 6716,31), Hα , and a nearby continuum band. The ratio of [S II]/Hα \\ emission discriminates well between shock-heated material charcteristic of SNRs and photo-ionized material such as H II regions. This technique has proved highly effective in surveys of other galaxies (e.g. Long et al., Ap J Supp, 72, 61). Deep emission-line images and a continuum band closely matched in wavelength enable us to subtract virtually the entire stellar contribution and thus achieve high sensitivity to faint, diffuse emission. We have identified 13 objects, all of which have [S II]/Hα \\ ratios > 0.4\\ and a full or partial shell-like morphology, making them extremely strong SNR candidates. Several other diffuse objects have high [S II]/Hα \\ ratios, and many of these may also be SNRs. Compared with the 12 previously known remnants of Mathewson et al., (Ap J Supp 51, 345; 55, 189), the new candidates are generally larger and have lower surface brightness. An investigation of the cumulative number vs diameter relation for our larger sample indicates a slope significantly steeper than the value near unity originally found by Mathewson et al., and is more consistent with standard models for SNR evolution. Selection effects may well have led to an excess of small, bright objects in the earlier samples. This work was supported in part by NSF grant AST-9114935 and by the W.M. Keck Foundation through the Keck Northeast Astronomy Consortium.
The Demand for Disaster Microinsurance for Small Businesses in Urban Slums: The Results of Surveys in Three Indian Cities.

PubMed

Patel, Ronak; Walker, Garrett; Bhatt, Mihir; Pathak, Vishal

2017-03-01

Small informal businesses make up the core markets for many poor urban communities, providing essential goods, services, and livelihoods. Many of these communities and businesses exist in hazardous locations. In most cases, these business owners do not have access to proper coping mechanisms including risk transfer and lack resilience to shocks. Access to risk-transfer in the form of insurance for these small businesses is extremely limited. This demand survey is the first phase of an intervention to test disaster microinsurance for these businesses. Previous research has examined the demand for and value of microinsurance to protect poor households but not micro- and medium-sized informal urban businesses. This study investigates knowledge about and demand for microinsurance among small informal business owners in three different cities of India. Survey of all informal business owners (n=4919) identified through purposive sampling of the most vulnerable in three proposed study sites: Guwahati in Assam (n=1622), Puri in Odisha (n=1551) and Cuddalore in Tamil Nadu (n=1746). Our findings reflect that while small business owners largely did not know about disaster microinsurance, after describing it, a vast majority wanted to subscribe to such a program. Without it, they often rely on personal savings, forgo basic necessities, or take out costly loans that trap them in debt to cope with disasters. This research supports the need for more experiments on actual adoption patterns, feasibility studies, and innovative trial programs by governments, non-governmental organizations, and insurance providers.
Cerebral Small Vessel Disease Burden Is Associated with Motor Performance of Lower and Upper Extremities in Community-Dwelling Populations

PubMed Central

Su, Ning; Zhai, Fei-Fei; Zhou, Li-Xin; Ni, Jun; Yao, Ming; Li, Ming-Li; Jin, Zheng-Yu; Gong, Gao-Lang; Zhang, Shu-Yang; Cui, Li-Ying; Tian, Feng; Zhu, Yi-Cheng

2017-01-01

Objective: To investigate the correlation between cerebral small vessel disease (CSVD) burden and motor performance of lower and upper extremities in community-dwelling populations. Methods: We performed a cross-sectional analysis on 770 participants enrolled in the Shunyi study, which is a population-based cohort study. CSVD burden, including white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), perivascular spaces (PVS), and brain atrophy were measured using 3T magnetic resonance imaging. All participants underwent quantitative motor assessment of lower and upper extremities, which included 3-m walking speed, 5-repeat chair-stand time, 10-repeat pronation–supination time, and 10-repeat finger-tapping time. Data on demographic characteristics, vascular risk factors, and cognitive functions were collected. General linear model analysis was performed to identify potential correlations between motor performance measures and imaging markers of CSVD after controlling for confounding factors. Results: For motor performance of the lower extremities, WMH was negatively associated with gait speed (standardized β = -0.092, p = 0.022) and positively associated with chair-stand time (standardized β = 0.153, p < 0.0001, surviving FDR correction). For motor performance of the upper extremities, pronation–supination time was positively associated with WMH (standardized β = 0.155, p < 0.0001, surviving FDR correction) and negatively with brain parenchymal fraction (BPF; standardized β = -0.125, p = 0.011, surviving FDR correction). Only BPF was found to be negatively associated with finger-tapping time (standardized β = -0.123, p = 0.012). However, lacunes, CMBs, or PVS were not found to be associated with motor performance of lower or upper extremities in multivariable analysis. Conclusion: Our findings suggest that cerebral microstructural changes related to CSVD may affect motor performance of both lower and upper extremities. WMH and brain atrophy are most strongly associated with motor function deterioration in community-dwelling populations. PMID:29021757

Applying Customized Climate Advisory Information to Translate Extreme Rainfall Events into Farming Options in the Sudan-Sahel of West Africa

NASA Astrophysics Data System (ADS)

Salack, S.; Worou, N. O.; Sanfo, S.; Nikiema, M. P.; Boubacar, I.; Paturel, J. E.; Tondoh, E. J.

2017-12-01

In West Africa, the risk of food insecurity linked to the low productivity of small holder farming increases as a result of rainfall extremes. In its recent evolution, the rainy season in the Sudan-Sahel zone presents mixed patterns of extreme climatic events. In addition to intense rain events, the distribution of events is associated with pockets of intra-seasonal long dry spells. The negative consequences of these mixed patterns are obvious on the farm: soil water logging, erosion of arable land, dwartness and dessication of crops, and loss in production. The capacity of local farming communities to respond accordingly to rainfall extreme events is often constrained by lack of access to climate information and advisory on smart crop management practices that can help translate extreme rainfall events into farming options. The objective of this work is to expose the framework and the pre-liminary results of a scheme that customizes climate-advisory information package delivery to subsistence farmers in Bakel (Senegal), Ouahigouya & Dano (Burkina Faso) and Bolgatanga (Ghana) for sustainable family agriculture. The package is based on the provision of timely climate information (48-hours, dekadal & seasonal) embedded with smart crop management practices to explore and exploite the potential advantage of intense rainfall and extreme dry spells in millet, maize, sorghum and cowpea farming communities. It is sent via mobile phones and used on selected farms (i.e agro-climatic farm schools) on which some small on-farm infrastructure were built to alleviate negative impacts of weather. Results provide prominent insight on how co-production of weather/climate information, customized access and guidiance on its use can induce fast learning (capacity building of actors), motivation for adaptation, sustainability, potential changes in cropping system, yields and family income in the face of a rainfall extremes at local scales of Sudan-Sahel of West Africa. Keywords: Climate Information, Smart Practices, Farming Options, Agro-Climatic Farm Schools, Sudan-Sahel
Cerebral Small Vessel Disease Burden Is Associated with Motor Performance of Lower and Upper Extremities in Community-Dwelling Populations.

PubMed

Su, Ning; Zhai, Fei-Fei; Zhou, Li-Xin; Ni, Jun; Yao, Ming; Li, Ming-Li; Jin, Zheng-Yu; Gong, Gao-Lang; Zhang, Shu-Yang; Cui, Li-Ying; Tian, Feng; Zhu, Yi-Cheng

2017-01-01

Objective: To investigate the correlation between cerebral small vessel disease (CSVD) burden and motor performance of lower and upper extremities in community-dwelling populations. Methods: We performed a cross-sectional analysis on 770 participants enrolled in the Shunyi study, which is a population-based cohort study. CSVD burden, including white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), perivascular spaces (PVS), and brain atrophy were measured using 3T magnetic resonance imaging. All participants underwent quantitative motor assessment of lower and upper extremities, which included 3-m walking speed, 5-repeat chair-stand time, 10-repeat pronation-supination time, and 10-repeat finger-tapping time. Data on demographic characteristics, vascular risk factors, and cognitive functions were collected. General linear model analysis was performed to identify potential correlations between motor performance measures and imaging markers of CSVD after controlling for confounding factors. Results: For motor performance of the lower extremities, WMH was negatively associated with gait speed (standardized β = -0.092, p = 0.022) and positively associated with chair-stand time (standardized β = 0.153, p < 0.0001, surviving FDR correction). For motor performance of the upper extremities, pronation-supination time was positively associated with WMH (standardized β = 0.155, p < 0.0001, surviving FDR correction) and negatively with brain parenchymal fraction (BPF; standardized β = -0.125, p = 0.011, surviving FDR correction). Only BPF was found to be negatively associated with finger-tapping time (standardized β = -0.123, p = 0.012). However, lacunes, CMBs, or PVS were not found to be associated with motor performance of lower or upper extremities in multivariable analysis. Conclusion: Our findings suggest that cerebral microstructural changes related to CSVD may affect motor performance of both lower and upper extremities. WMH and brain atrophy are most strongly associated with motor function deterioration in community-dwelling populations.
How to recover more value from small pine trees: Essential oils and resins

Treesearch

Vasant M. Kelkar; Brian W. Geils; Dennis R. Becker; Steven T. Overby; Daniel G. Neary

2006-01-01

In recent years, the young dense forests of northern Arizona have suffered extreme droughts, wildfires, and insect outbreaks. Improving forest health requires reducing forest density by cutting many small-diameter trees with the consequent production of large volumes of residual biomass. To offset the cost of handling this low-value timber, additional marketing options...
Small Body Size at Birth and Behavioural Symptoms of ADHD in Children Aged Five to Six Years

ERIC Educational Resources Information Center

Lahti, J.; Raikkonen, K.; Kajantie, E.; Heinonen, K.; Pesonen, A.-K.; Jarvenpaa, A.-L.; Strandberg, T.

2006-01-01

Background: Behavioural disorders with a neurodevelopmental background, such as attention deficit hyperactivity disorder (ADHD), have been associated with a non-optimal foetal environment, reflected in small body size at birth. However, the evidence stems from highly selected groups with birth outcomes biased towards the extreme low end of the…
Simple Assessment Techniques for Soil and Water. Environmental Factors in Small Scale Development Projects. Workshops.

ERIC Educational Resources Information Center

Coordination in Development, New York, NY.

This booklet was produced in response to the growing need for reliable environmental assessment techniques that can be applied to small-scale development projects. The suggested techniques emphasize low-technology environmental analysis. Although these techniques may lack precision, they can be extremely valuable in helping to assure the success…
First Constraints on Fuzzy Dark Matter from Lyman-α Forest Data and Hydrodynamical Simulations.

PubMed

Iršič, Vid; Viel, Matteo; Haehnelt, Martin G; Bolton, James S; Becker, George D

2017-07-21

We present constraints on the masses of extremely light bosons dubbed fuzzy dark matter (FDM) from Lyman-α forest data. Extremely light bosons with a de Broglie wavelength of ∼1 kpc have been suggested as dark matter candidates that may resolve some of the current small scale problems of the cold dark matter model. For the first time, we use hydrodynamical simulations to model the Lyman-α flux power spectrum in these models and compare it to the observed flux power spectrum from two different data sets: the XQ-100 and HIRES/MIKE quasar spectra samples. After marginalization over nuisance and physical parameters and with conservative assumptions for the thermal history of the intergalactic medium (IGM) that allow for jumps in the temperature of up to 5000 K, XQ-100 provides a lower limit of 7.1×10^{-22} eV, HIRES/MIKE returns a stronger limit of 14.3×10^{-22} eV, while the combination of both data sets results in a limit of 20×10^{-22} eV (2σ C.L.). The limits for the analysis of the combined data sets increases to 37.5×10^{-22} eV (2σ C.L.) when a smoother thermal history is assumed where the temperature of the IGM evolves as a power law in redshift. Light boson masses in the range 1-10×10^{-22} eV are ruled out at high significance by our analysis, casting strong doubts that FDM helps solve the "small scale crisis" of the cold dark matter models.
Determination of line profiles on nano-structured surfaces using EUV and x-ray scattering

NASA Astrophysics Data System (ADS)

Soltwisch, Victor; Wernecke, Jan; Haase, Anton; Probst, Jürgen; Schoengen, Max; Krumrey, Michael; Scholze, Frank; Pomplun, Jan; Burger, Sven

2014-09-01

Non-imaging techniques like X-ray scattering are supposed to play an important role in the further development of CD metrology for the semiconductor industry. Grazing Incidence Small Angle X-ray Scattering (GISAXS) provides directly assessable information on structure roughness and long-range periodic perturbations. The disadvantage of the method is the large footprint of the X-ray beam on the sample due to the extremely shallow angle of incidence. This can be overcome by using wavelengths in the extreme ultraviolet (EUV) spectral range, EUV small angle scattering (EUVSAS), which allows for much steeper angles of incidence but preserves the range of momentum transfer that can be observed. Generally, the potentially higher momentum transfer at shorter wavelengths is counterbalanced by decreasing diffraction efficiency. This results in a practical limit of about 10 nm pitch for which it is possible to observe at least the +/- 1st diffraction orders with reasonable efficiency. At the Physikalisch-Technische Bundesanstalt (PTB), the available photon energy range extends from 50 eV up to 10 keV at two adjacent beamlines. PTB commissioned a new versatile Ellipso-Scatterometer which is capable of measuring 6" square substrates in a clean, hydrocarbon-free environment with full flexibility regarding the direction of the incident light polarization. The reconstruction of line profiles using a geometrical model with six free parameters, based on a finite element method (FEM) Maxwell solver and a particle swarm based least-squares optimization yielded consistent results for EUV-SAS and GISAXS. In this contribution we present scatterometry data for line gratings and consistent reconstruction results of the line geometry for EUV-SAS and GISAXS.
High-resolution Spectroscopy of Extremely Metal-poor Stars from SDSS/SEGUE. III. Unevolved Stars with [Fe/H] ≲ -3.5

NASA Astrophysics Data System (ADS)

Matsuno, Tadafumi; Aoki, Wako; Beers, Timothy C.; Lee, Young Sun; Honda, Satoshi

2017-08-01

We present elemental abundances for eight unevolved extremely metal-poor (EMP) stars with {T}{eff}> 5500 {{K}}, among which seven have [{Fe}/{{H}}]< -3.5. The sample is selected from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration (SDSS/SEGUE) and our previous high-resolution spectroscopic follow-up with the Subaru Telescope. Several methods to derive stellar parameters are compared, and no significant offset in the derived parameters is found in most cases. From an abundance analysis relative to the standard EMP star G64-12, an average Li abundance for stars with [{Fe}/{{H}}]< -3.5 is A({Li})=1.90, with a standard deviation of σ =0.10 dex. This result confirms that lower Li abundances are found at lower metallicity, as suggested by previous studies, and demonstrates that the star-to-star scatter is small. The small observed scatter could be a strong constraint on Li-depletion mechanisms proposed for explaining the low Li abundance at lower metallicity. Our analysis for other elements obtained the following results: (I) a statistically significant scatter in [{{X}}/{Fe}] for Na, Mg, Cr, Ti, Sr, and Ba, and an apparent bimodality in [{Na}/{Fe}] with a separation of ˜ 0.8 {dex}, (II) an absence of a sharp drop in the metallicity distribution, and (III) the existence of a CEMP-s star at [{Fe}/{{H}}]≃ -3.6 and possibly at [{Fe}/{{H}}]≃ -4.0, which may provide a constraint on the mixing efficiency of unevolved stars during their main-sequence phase. Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.
3-D Surface Depression Profiling Using High Frequency Focused Air-Coupled Ultrasonic Pulses

NASA Technical Reports Server (NTRS)

Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

1999-01-01

Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. This article shows quantitative surface topography profiles as obtained using only high-frequency focused air-coupled ultrasonic pulses. The profiles were obtained using a profiling system developed by NASA Glenn Research Center and Sonix, Inc (via a formal cooperative agreement). (The air transducers are available as off-the-shelf items from several companies.) The method is simple and reproducible because it relies mainly on knowledge and constancy of the sound velocity through the air. The air transducer is scanned across the surface and sends pulses to the sample surface where they are reflected back from the surface along the same path as the incident wave. Time-of-flight images of the sample surface are acquired and converted to depth/surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in air (V). The system has the ability to resolve surface depression variations as small as 25 microns, is useable over a 1.4 mm vertical depth range, and can profile large areas only limited by the scan limits of the particular ultrasonic system. (Best-case depth resolution is 0.25 microns which may be achievable with improved isolation from vibration and air currents.) The method using an optimized configuration is reasonably rapid and has all quantitative analysis facilities on-line including 2-D and 3-D visualization capability, extreme value filtering (for faulty data), and leveling capability. Air-coupled surface profilometry is applicable to plate-like and curved samples. In this article, results are shown for several proof-of-concept samples, plastic samples burned in microgravity on the STS-54 space shuttle mission, and a partially-coated cylindrical ceramic composite sample. Impressive results were obtained for all samples when compared with diamond-tip profiles and measurements from micrometers. The method is completely nondestructive, noninvasive, non-contact and does not require light-reflective surfaces.
Fetal primary small bowel volvulus in a child without intestinal malrotation.

PubMed

Chung, Jae Hee; Lim, Gye-Yeon; We, Ji Sun

2013-07-01

Fetal primary small bowel volvulus without atresia or malrotation is an extremely rare but life-threatening surgical emergency. We report a case of primary small bowel volvulus that presented as sudden fetal distress and was diagnosed on the basis of the 'whirl-pool sign' of fetal sonography. This diagnosis led to emergency operation after birth at the third trimester with a good outcome. Although the pathogenesis of fetal primary small bowel volvulus is unclear, ganglion cell immaturity may play a role in the etiology. Copyright © 2013 Elsevier Inc. All rights reserved.
Alterations in plant community niche hypervolume and functional group representation to accommodate extreme drought

NASA Astrophysics Data System (ADS)

Mao, W.; Sun, Z.; Felton, A. J.; Zhao, X.; Zhang, T.; Li, Y.; Smith, M. D.

2017-12-01

We used the method of `niche hypervolume' to study how plant communities accommodate extreme environmental changes. Due to the gradual decreases in precipitation, the desert-steppe ecotone in western of Inner Mongolia, an already arid region, has large shifts in species composition within short geographical ranges. Based on precipitation and species composition, we divided this study area into four categories: desert area (D), partial desert area (pD), partial steppe area (pS) and steppe area(S). We sampled along a climatic gradient of precipitation. We selected four transects, in each transect 100-125 quadrats were randomly selected, with 425 quadrats sampled in total. We assessed species composition of each sampling quadrat, and collected leaves of every species that appeared in every quadrat. We also studied the change of plant community weighted means of leaf traits (CWM) along the precipitation gradient. Leaf traits (phenotypic traits, i.e. SLA, LDMC and stoichiometry traits, i.e. LNC, LCC) were used to calculate the changes in `niche hypervolume'. Our results show that: 1) with decreases in precipitation, species richness and functional group types (PFTs) change. Species richness and functional groups were the highest in the pD area, while the species richness and functional groups in the desert area were the lowest. 2), CWM-SLA in the desert area was relatively small, while CWM-SLA in pD area, the pS area, and the steppe area are more similar. CWM-LNC decreases as precipitation decreases, consistent with CWM-LCC trends. While CWM-LDMC of the desert area was the highest, and CWM-LDMC in desert area was the lowest. The dynamics of CWM traits suggests that species in the desert region have slower growth rates, while species in the transitional zone and steppe area have relatively higher growth rates. Finally, the pD area had the highest niche hypervolume, while the steppe area had the lowest hypervolume, which may be closely related to the high level of PFTs. These results suggest that even in drought-prone ecosystems, plants yield multiple life strategies to adapt to stressful environments. While under extreme drought conditions, environmental filters will remove species with unsuitable traits, like perennial species in this study, leaving shrubs and other drought tolerant species to survive.
Association of athlete's foot with cellulitis of the lower extremities: diagnostic value of bacterial cultures of ipsilateral interdigital space samples.

PubMed

Semel, J D; Goldin, H

1996-11-01

We performed a study to determine how often patients with cellulitis of the lower extremities in the absence of trauma, peripheral vascular disease, or chronic open ulcers have ipsilateral interdigital athlete's foot and whether cultures of samples from the involved interdigital spaces would yield potentially pathogenic bacteria. Athlete's foot was present in 20 (83%) of 24 episodes of cellulitis that were studied. Cultures of samples from interdigital spaces yielded Beta-hemolytic streptococci in 17 (85%) of 20 cases, Staphylococcus aureus in 9 (45%) of 20 cases, and gram-negative rods in 7 (35%) of 20 cases. Only Beta-hemolytic streptococci were recovered significantly more often from patients than from a group of controls with athlete's foot who did not have cellulitis (P < .01). Athlete's foot may be a common predisposing condition for cellulitis of the lower extremities. In comparison with attempts at microbiological diagnosis such as aspiration and/or biopsy of the area of cellulitis, cultures of samples from the interdigital spaces combined with serial determinations of antistreptolysin titers may offer a simpler noninvasive method of microbiological diagnosis.
Sources of variability in collection and preparation of paint and lead-coating samples.

PubMed

Harper, S L; Gutknecht, W F

2001-06-01

Chronic exposure of children to lead (Pb) can result in permanent physiological impairment. Since surfaces coated with lead-containing paints and varnishes are potential sources of exposure, it is extremely important that reliable methods for sampling and analysis be available. The sources of variability in the collection and preparation of samples were investigated to improve the performance and comparability of methods and to ensure that data generated will be adequate for its intended use. Paint samples of varying sizes (areas and masses) were collected at different locations across a variety of surfaces including metal, plaster, concrete, and wood. A variety of grinding techniques were compared. Manual mortar and pestle grinding for at least 1.5 min and mechanized grinding techniques were found to generate similar homogenous particle size distributions required for aliquots as small as 0.10 g. When 342 samples were evaluated for sample weight loss during mortar and pestle grinding, 4% had 20% or greater loss with a high of 41%. Homogenization and sub-sampling steps were found to be the principal sources of variability related to the size of the sample collected. Analysis of samples from different locations on apparently identical surfaces were found to vary by more than a factor of two both in Pb concentration (mg cm-2 or %) and areal coating density (g cm-2). Analyses of substrates were performed to determine the Pb remaining after coating removal. Levels as high as 1% Pb were found in some substrate samples, corresponding to more than 35 mg cm-2 Pb. In conclusion, these sources of variability must be considered in development and/or application of any sampling and analysis methodologies.
Wavelength Comparisons

NASA Image and Video Library

2018-04-02

NASA's Solar Dynamics Observatory ran together three sequences of the sun taken in three different extreme ultraviolet wavelengths to better illustrate how different features that appear in one sequence are difficult if not impossible to see in the others (Mar. 20-21, 2018). In the red sequence (304 Angstroms), we can see very small spicules and some small prominences at the sun's edge, which are not easy to see in the other two sequences. In the second clip (193 Angstroms), we can readily observe the large and dark coronal hole, though it is difficult to make out in the others. In the third clip (171 wavelengths), we can see strands of plasma waving above the surface, especially above the one small, but bright, active region near the right edge. And these are just three of the 10 extreme ultraviolet wavelengths in which SDO images the sun every 12 seconds every day. That's a lot of data and a lot of science. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA22360
Small Flare and a Coronal Mass Ejection

NASA Image and Video Library

2018-01-31

The sun shot out a small coronal mass ejection that was also associated with a small flare (Jan. 22, 2018). The video, which covers about 5 hours, shows the burst of plasma as the magnetic loops break apart. Immediately the magnetic fields brighten intensely and begin to reorganize themselves in coils above the active region. The images were taken in a wavelength of extreme ultraviolet light. Videos are available at https://photojournal.jpl.nasa.gov/catalog/PIA22184
Spitzer 24 Micron Observations of Optical/Near-Infrared-Selected Extremely Red Galaxies: Evidence for Assembly of Massive Galaxies at Z approximately equal to 1-2?

NASA Technical Reports Server (NTRS)

Yan, Lin; Choi, Philip I.; Fadda, D.; Marleau, F. R.; Soifer, B. T.; Im, M.; Armus, L.; Frayer, D. T.; Storrie-Lombardi, L. J.; Thompson, D. J.;

2004-01-01

We carried out direct measurement of the fraction of dusty sources in a sample of extremely red galaxies with (R - Ks) >= 5.3 mag and Ks < 20:2 mag, using 24 micron data from the Spitzer Space Telescope. Combining deep 24 micron Ks- and R-band data over an area of 64 arcmin(sup 2) in ELAIS N1 of the Spitzer First Look Survey (FLS), we find that 50% +/- 6% of our extremely red object (ERO) sample have measurable 24 micron flux above the 3 (sigma) flux limit of 40 (micro)Jy. This flux limit corresponds to a star formation rate (SFR) of 12 solar masses per year 1, much more sensitive than any previous long-wavelength measurement. The 24 micron-detected EROs have 24 micron/2.2 micron and 24 micron/0.7 micron flux ratios consistent with infrared luminous, dusty sources at z >= 1, and are an order of magnitude too red to be explained by an infrared quiescent spiral or a pure old stellar population at any redshift. Some of these 24 micron-detected EROs could be active galactic nuclei; however, the fraction among the whole ERO sample is probably small, 10%-20%, as suggested by deep X-ray observations as well as optical spectroscopy. Keck optical spectroscopy of a sample of similarly selected EROs in the FLS field suggests that most of the EROs in ELAIS N1 are probably at z 1. The mean 24 micron flux (167 (micro)Jy) of the 24 micron-detected ERO sample roughly corresponds to the rest-frame 12 micron luminosity, (nu)L(nu)(12 micron, of 3x10(exp 10)(deg) solar luminosities at z 1. Using the c IRAS (nu)L(nu)(12 (micron) and infrared luminosity LIR(8-1000 (micron), we infer that the (LIR) of the 24 micron- detected EROs is 3 x 10(exp 11) and 1 x 10(exp 12) solar luminosities at z = 1.0 and similar to that of local luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies (ULIRGs). The corresponding SFR would be roughly 50-170 solar masses per year. If the timescale of this starbursting phase is on the order of 108 yr as inferred for the local LIRGs and ULIRGs, the lower limit on the masses of these 24 micron-detected EROs is 5 x 10(exp 9) to 2 x 10(exp 10) solar masses. It is plausible that some of the starburst EROs are in the midst of a violent transformation to become massive early type galaxies at the epoch of z 1-2.

An H-band Vector Vortex Coronagraph for the Subaru Coronagraphic Extreme-adaptive Optics System

NASA Astrophysics Data System (ADS)

Kühn, J.; Serabyn, E.; Lozi, J.; Jovanovic, N.; Currie, T.; Guyon, O.; Kudo, T.; Martinache, F.; Liewer, K.; Singh, G.; Tamura, M.; Mawet, D.; Hagelberg, J.; Defrere, D.

2018-03-01

The vector vortex is a coronagraphic imaging mode of the recently commissioned Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) platform on the 8 m Subaru Telescope. This multi-purpose high-contrast visible and near-infrared (R- to K-band) instrument is not only intended to serve as a VLT-class “planet-imager” instrument in the northern hemisphere, but also to operate as a technology demonstration testbed ahead of the ELTs-era, with a particular emphasis on small inner-working angle (IWA) coronagraphic capabilities. The given priority to small-IWA imaging led to the early design choice to incorporate focal-plane phase-mask coronagraphs. In this context, a test H-band vector vortex liquid crystal polymer waveplate was provided to SCExAO, to allow a one-to-one comparison of different small-IWA techniques on the same telescope instrument, before considering further steps. Here we present a detailed overview of the vector vortex coronagraph, from its installation and performances on the SCExAO optical bench, to the on-sky results in the extreme AO regime, as of late 2016/early 2017. To this purpose, we also provide a few recent on-sky imaging examples, notably high-contrast ADI detection of the planetary-mass companion κ Andromedae b, with a signal-to-noise ratio above 100 reached in less than 10 mn exposure time.
Radiative heat transfer in the extreme near field.

PubMed

Kim, Kyeongtae; Song, Bai; Fernández-Hurtado, Víctor; Lee, Woochul; Jeong, Wonho; Cui, Longji; Thompson, Dakotah; Feist, Johannes; Reid, M T Homer; García-Vidal, Francisco J; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

2015-12-17

Radiative transfer of energy at the nanometre length scale is of great importance to a variety of technologies including heat-assisted magnetic recording, near-field thermophotovoltaics and lithography. Although experimental advances have enabled elucidation of near-field radiative heat transfer in gaps as small as 20-30 nanometres (refs 4-6), quantitative analysis in the extreme near field (less than 10 nanometres) has been greatly limited by experimental challenges. Moreover, the results of pioneering measurements differed from theoretical predictions by orders of magnitude. Here we use custom-fabricated scanning probes with embedded thermocouples, in conjunction with new microdevices capable of periodic temperature modulation, to measure radiative heat transfer down to gaps as small as two nanometres. For our experiments we deposited suitably chosen metal or dielectric layers on the scanning probes and microdevices, enabling direct study of extreme near-field radiation between silica-silica, silicon nitride-silicon nitride and gold-gold surfaces to reveal marked, gap-size-dependent enhancements of radiative heat transfer. Furthermore, our state-of-the-art calculations of radiative heat transfer, performed within the theoretical framework of fluctuational electrodynamics, are in excellent agreement with our experimental results, providing unambiguous evidence that confirms the validity of this theory for modelling radiative heat transfer in gaps as small as a few nanometres. This work lays the foundations required for the rational design of novel technologies that leverage nanoscale radiative heat transfer.
Survival of the faucet snail after chemical disinfection, pH extremes, and heated water bath treatments

USGS Publications Warehouse

Mitchell, A.J.; Cole, Rebecca A.

2008-01-01

The faucet snail Bithynia tentaculata, a nonindigenous aquatic snail from Eurasia, was introduced into Lake Michigan in 1871 and has spread to the mid-Atlantic states, the Great Lakes region, Montana, and most recently, the Mississippi River. The faucet snail serves as intermediate host for several trematodes that have caused large-scale mortality among water birds, primarily in the Great Lakes region and Montana. It is important to limit the spread of the faucet snail; small fisheries equipment can serve as a method of snail distribution. Treatments with chemical disinfection, pH extremes, and heated water baths were tested to determine their effectiveness as a disinfectant for small fisheries equipment. Two treatments eliminated all test snails: (1) a 24-h exposure to Hydrothol 191 at a concentration of at least 20 mg/L and (2) a treatment with 50°C heated water for 1 min or longer. Faucet snails were highly resistant to ethanol, NaCl, formalin, Lysol, potassium permanganate, copper sulfate, Baquacil, Virkon, household bleach, and pH extremes (as low as 1 and as high as 13).
Nonstationarity in timing of extreme precipitation across China and impact of tropical cyclones

NASA Astrophysics Data System (ADS)

Gu, Xihui; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun

2017-02-01

This study examines the seasonality and nonstationarity in the timing of extreme precipitation obtained by annual maximum (AM) sampling and peak-over-threshold (POT) sampling techniques using circular statistics. Daily precipitation data from 728 stations with record length of at least 55 years across China were analyzed. In general, the average seasonality is subject mainly to summer season (June-July - August), which is potentially related to East Asian monsoon and Indian monsoon activities. The strength of precipitation seasonality varied across China with the highest strength being in northeast, north, and central-north China; whereas the weakest seasonality was found in southeast China. There are three seasonality types: circular uniform, reflective symmetric, and asymmetric. However, the circular uniform seasonality of extreme precipitation was not detected at stations across China. The asymmetric distribution was observed mainly in southeast China, and the reflective distribution of precipitation extremes was also identified the other regions besides the above-mentioned regions. Furthermore, a strong signal of nonstationarity in the seasonality was detected at half of the weather stations considered in the study, exhibiting a significant shift in the timing of extreme precipitation, and also significant trends in the average and strength of seasonality. Seasonal vapor flux and related delivery pathways and also tropical cyclones (TCs) are most probably the driving factors for the shifts or changes in the seasonality of extreme precipitation across China. Timing of precipitation extremes is closely related to seasonal shifts of floods and droughts and which means much for management of agricultural irrigation and water resources management. This study sheds new light on nonstationarity in timing of precipitation extremes which differs from existing ones which focused on precipitation extremes from perspective of magnitude and intensity.

A sub-sampled approach to extremely low-dose STEM

DOE PAGES

Stevens, A.; Luzi, L.; Yang, H.; ...

2018-01-22

The inpainting of deliberately and randomly sub-sampled images offers a potential means to image specimens at a high resolution and under extremely low-dose conditions (≤1 e -/Å 2) using a scanning transmission electron microscope. We show that deliberate sub-sampling acquires images at least an order of magnitude faster than conventional low-dose methods for an equivalent electron dose. More importantly, when adaptive sub-sampling is implemented to acquire the images, there is a significant increase in the resolution and sensitivity which accompanies the increase in imaging speed. Lastly, we demonstrate the potential of this method for beam sensitive materials and in-situ observationsmore » by experimentally imaging the node distribution in a metal-organic framework.« less
A sub-sampled approach to extremely low-dose STEM

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

Stevens, A.; Luzi, L.; Yang, H.

The inpainting of deliberately and randomly sub-sampled images offers a potential means to image specimens at a high resolution and under extremely low-dose conditions (≤1 e -/Å 2) using a scanning transmission electron microscope. We show that deliberate sub-sampling acquires images at least an order of magnitude faster than conventional low-dose methods for an equivalent electron dose. More importantly, when adaptive sub-sampling is implemented to acquire the images, there is a significant increase in the resolution and sensitivity which accompanies the increase in imaging speed. Lastly, we demonstrate the potential of this method for beam sensitive materials and in-situ observationsmore » by experimentally imaging the node distribution in a metal-organic framework.« less
Modelling maximum river flow by using Bayesian Markov Chain Monte Carlo

NASA Astrophysics Data System (ADS)

Cheong, R. Y.; Gabda, D.

2017-09-01

Analysis of flood trends is vital since flooding threatens human living in terms of financial, environment and security. The data of annual maximum river flows in Sabah were fitted into generalized extreme value (GEV) distribution. Maximum likelihood estimator (MLE) raised naturally when working with GEV distribution. However, previous researches showed that MLE provide unstable results especially in small sample size. In this study, we used different Bayesian Markov Chain Monte Carlo (MCMC) based on Metropolis-Hastings algorithm to estimate GEV parameters. Bayesian MCMC method is a statistical inference which studies the parameter estimation by using posterior distribution based on Bayes’ theorem. Metropolis-Hastings algorithm is used to overcome the high dimensional state space faced in Monte Carlo method. This approach also considers more uncertainty in parameter estimation which then presents a better prediction on maximum river flow in Sabah.
Analysis for Mar Vel Black and acetylene soot low reflectivity surfaces for star tracker sunshade applications

NASA Technical Reports Server (NTRS)

Yung, E.

1974-01-01

Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A sample of Mar Vel Black was evaluated. Mar Vel Black looks much like a super black surface with many small peaks and very steep sides so that any light incident upon the surface will tend to reflect many times before exiting that surface. Even a high reflectivity surface would thus appear to have a very low reflectivity under such conditions. Conversely, acetylene soot does not have the magnified surface appearance of a super black surface. Its performance is, however, predictable from the surface structure, considering the known configuration of virtually pure carbon.
X-ray Reflectivity Study of a Highly Rough Surface: Si Nanowires Grown by Ag Nanoparticle Etching

NASA Astrophysics Data System (ADS)

Kremenak, Jesse; Arendse, Christopher; Cummings, Franscious; Chen, Yiyao; Miceli, Paul

Vertically oriented Si nanowires (SiNWs) formed by Ag-assisted wet chemical etching of a Si(100) substrate was studied by X-ray reflectivity (XRR) in combination with electron microscopy. Si(100) wafers coated with Ag nanoparticles, which serve as a catalyst, were etched for different durations in a HF/H2O2/DI-H2O solution. Because of the extreme roughness of these surfaces, there are challenges for using XRR methods in such systems. Therefore, significant attention is given to the analysis method of the XRR measurements. This sample-average information presents a valuable complement to electron microscopy studies, which focus on small sections of the sample. The present work shows-for the first time-the amount and distribution of Ag during the formation of SiNWs fabricated by Ag-assisted wet chemical etching, which is vital information for understanding the etching mechanisms. Support is gratefully acknowledged from the National Science Foundation (USA) - DGE1069091, the National Research Foundation (RSA) - TTK14052167658, 76568, 92520, and 93212; and the University of Missouri/University of Western Cape Linkage Program.
Neutron Focusing Mirrors for Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

NASA Astrophysics Data System (ADS)

Rai, Durgesh K.; Wu, Huarui; Abir, Muhammad; Giglio, Jeffrey; Khaykovich, Boris

Post irradiation examination (PIE) of samples irradiated in nuclear reactors is a challenging but necessary task for the development on novel nuclear power reactors. Idaho National Laboratory (INL) has neutron radiography capabilities, which are especially useful for the PIE of irradiated nuclear fuel. These capabilities are limited due to the extremely high gamma-ray radiation from the irradiated fuel, which precludes the use of standard digital detectors, in turn limiting the ability to do tomography and driving the cost of the measurements. In addition, the small 250 kW Neutron Radiography Reactor (NRAD) provides a relatively weak neutron flux, which leads to low signal-to-noise ratio. In this work, we develop neutron focusing optics suitable for the installation at NRAD. The optics would separate the sample and the detector, potentially allowing for the use of digital radiography detectors, and would provide significant intensity enhancement as well. The optics consist of several coaxial nested Wolter mirrors and is suited for polychromatic thermal neutron radiation. Laboratory Directed Research and Development program of Idaho National Laboratory.
Test anxiety in mathematics among early undergraduate students in a British university in Malaysia

NASA Astrophysics Data System (ADS)

Karjanto, Natanael; Yong, Su Ting

2013-03-01

The level of test anxiety in mathematics subjects among early undergraduate students at the University of Nottingham Malaysia Campus is studied in this article. The sample consists of 206 students taking several mathematics modules who completed the questionnaires on test anxiety just before they entered the venue for midterm examinations. The sample data include the differences in the context of academic levels, gender groups and nationality backgrounds. The level of test anxiety in mathematics is measured using seven Likert questionnaire statements adapted from the Test Anxiety Inventory describing one's emotional feeling before the start of an examination. In general, the result shows that the students who had a lower score expectation were more anxious than those who had a higher score expectation, but that they obtained a better score than the expected score. In the context of academic levels, gender groups and nationality backgrounds, there were no significant correlations between the level of test anxiety and the students' academic performance. The effect size of the correlation values ranged from extremely small to moderate.
Peculiar phase diagram with isolated superconducting regions in ThFeAsN1‑x O x

NASA Astrophysics Data System (ADS)

Li, Bai-Zhuo; Wang, Zhi-Cheng; Wang, Jia-Lu; Zhang, Fu-Xiang; Wang, Dong-Ze; Zhang, Feng-Yuan; Sun, Yu-Ping; Jing, Qiang; Zhang, Hua-Fu; Tan, Shu-Gang; Li, Yu-Ke; Feng, Chun-Mu; Mei, Yu-Xue; Wang, Cao; Cao, Guang-Han

2018-06-01

ThFeAsN1‑x O x () system with heavy electron doping has been studied by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility and specific heat. The non-doped compound exhibits superconductivity at K, which is possibly due to an internal uniaxial chemical pressure that is manifested by the extremely small value of As height with respect to the Fe plane. With the oxygen substitution, the T c value decreases rapidly to below 2 K for , and surprisingly, superconductivity re-appears in the range of with a maximum of 17.5 K at x = 0.3. For the normal-state resistivity, while the samples in intermediate non-superconducting interval exhibit Fermi liquid behavior, those in other regions show a non-Fermi-liquid behavior. The specific heat jump for the superconducting sample of x = 0.4 is , which is discussed in terms of anisotropic superconducting gap. The peculiar phase diagram in ThFeAsN1‑x O x presents additional ingredients for understanding the superconducting mechanism in iron-based superconductors.
Sub-μL measurements of the thermal conductivity and heat capacity of liquids.

PubMed

López-Bueno, C; Bugallo, D; Leborán, V; Rivadulla, F

2018-03-07

We present the analysis of the thermal conductivity, κ, and heat capacity, C p , of a wide variety of liquids, covering organic molecular solvents, ionic liquids and water-polymer mixtures. These data were obtained from ≈0.6 μL samples, using an experimental development based on the 3ω method, capable of the simultaneous measurement of κ and C p . In spite of the different type and strength of interactions, expected in a priori so different systems, the ratio of κ to the sound velocity is approximately constant for all of them. This is the consequence of a similar atomic density for all these liquids, notwithstanding their different molecular structures. This was corroborated experimentally by the observation of a C p /V ≈ 1.89 × 10 6 J K -1 m -3 (≈3R/2 per atom), for all liquids studied in this work. Finally, the very small volume of the sample required in this experimental method is an important advantage for the characterization of systems like nanofluids, in which having a large amount of the dispersed phase is sometimes extremely challenging.
Surface microroughness of ion-beam etched optical surfaces

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

Savvides, N.

2005-03-01

Ion-beam etching (IBE) and ion-beam figuring techniques using low-energy ion-beam sources have been applied for more than ten years in the fabrication and finishing of extremely smooth high-performance optics. We used optical interferometric techniques and atomic force microscopy to study the evolution of the surface root-mean-square (rms) microroughness, Rq, as a function of depth of a material removed (0-3000 nm) by a broad ion-beam source (Ar{sup +} ions of energy 600 eV and ion current density of 1 mA cm{sup -2}). Highly polished samples of fused silica and Zerodur (Rq{approx}3.5 A) showed a small decrease in microroughness (to 2.5 A)more » after 3000-nm IBE removal while an ultrapolished single-crystal sapphire sample (Rq{approx}1 A rms) retained its very low microroughness during IBE. Power spectral density functions over the spatial frequency interval of measurement (f=5x10{sup -3}-25 {mu}m{sup -1}) indicate that the IBE surfaces have minimal subsurface damage and low optical scatter.« less
XAFS imaging of Tsukuba gabbroic rocks: area analysis of chemical composition and local structure.

PubMed

Mizusawa, Mari; Sakurai, Kenji

2004-03-01

Gabbroic rocks were collected at Mount Tsukuba in Japan, and their XAFS images were studied using a projection-type X-ray fluorescence (XRF) microscope, which is a powerful new tool recently developed for extremely rapid imaging. The instrument employs a grazing-incidence arrangement in order that primary X-rays illuminate the whole sample surface, as well as parallel-beam optics and an extremely close geometry in order to detect XRF by a high-performance X-ray CCD system with 1024 x 1024 pixels. The XRF image indicated that black amphibole and white feldspar, both of which are typical mineral textures of the rock, contain iron. The origin has been suggested to be several small yellowish-brown minerals contained there. The XAFS imaging has been carried out by repeating the exposure of XRF images during the energy scan of the primary X-rays. It has been found that the structure is qualitatively close to that of olivine, and the main differences found in both areas can be explained as a difference in iron and magnesium concentration, i.e. the mixed ratio of forsterite (Mg(2)SiO(4)) and fayalite (Fe(2)SiO(4)). The feasibility of the present XAFS imaging method has been demonstrated for realistic inhomogeneous minerals.
Directly Imaging Exoplanets and Resolving Asteroid Belts Around Young Stars with SCExAO+HiCIAO/VAMPIRES

NASA Astrophysics Data System (ADS)

Currie, Thayne

2015-06-01

We propose a unique, first-of-its-kind combined near-IR high-contrast imaging and optical interferometry study of 20 young, debris disk-bearing stars with SCExAO + HiCIAO/VAMPIRES. Our sample includes the benchmark imaged exoplanets HR 8799 bcde; luminous, resolvable debris disks; stars with asteroid belts that have yet to be resolved in scattered light; poorly-studied stars whose disks may be resolvable; and stars with compelling planet candidates requiring rapid follow-up. From proven VAMPIRES performance, SCExAO near-IR advances and HiCIAO software and hardware upgrades from our team, our data will 1) resolve known debris belts and possible hitherto unseen asteroid belts and 2) yield significantly deeper contrasts at small (r = 0.1"-0.5") separations than typical HiCIAO data (e.g. 10^{-5} at 0.4"). With the likely-operational Pyramid WFS, we will achieve extreme contrasts (< 10^{-6} at r > 0.25") and planet detection capabilities rivaling/exceeding those from GPI and SPHERE. Our program is guaranteed to result in many publications reporting new insights on known exoplanets and disks, may yield the first optical/IR images of exo-asteroid belts/other exoplanets, and could firmly establish Subaru/SCExAO as the premier extreme-AO exoplanet imaging facility.
Microbial community analysis of the hypersaline water of the Dead Sea using high-throughput amplicon sequencing.

PubMed

Jacob, Jacob H; Hussein, Emad I; Shakhatreh, Muhamad Ali K; Cornelison, Christopher T

2017-10-01

Amplicon sequencing using next-generation technology (bTEFAP ® ) has been utilized in describing the diversity of Dead Sea microbiota. The investigated area is a well-known salt lake in the western part of Jordan found in the lowest geographical location in the world (more than 420 m below sea level) and characterized by extreme salinity (approximately, 34%) in addition to other extreme conditions (low pH, unique ionic composition different from sea water). DNA was extracted from Dead Sea water. A total of 314,310 small subunit RNA (SSU rRNA) sequences were parsed, and 288,452 sequences were then clustered. For alpha diversity analysis, sample was rarefied to 3,000 sequences. The Shannon-Wiener index curve plot reached a plateau at approximately 3,000 sequences indicating that sequencing depth was sufficient to capture the full scope of microbial diversity. Archaea was found to be dominating the sequences (52%), whereas Bacteria constitute 45% of the sequences. Altogether, prokaryotic sequences (which constitute 97% of all sequences) were found to predominate. The findings expand on previous studies by using high-throughput amplicon sequencing to describe the microbial community in an environment which in recent years has been shown to hide some interesting diversity. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
New early eocene anaptomorphine primate (Omomyidae) from the Washakie Basin, Wyoming, with comments on the phylogeny and paleobiology of anaptomorphines.

PubMed

Williams, B A; Covert, H H

1994-03-01

Recent paleontological collecting in the Washakie Basin, southcentral Wyoming, has resulted in the recovery of over 100 specimens of omomyid primates from the lower Eocene Wasatch Formation. Much of what is known about anaptomorphine omomyids is based upon work in the Bighorn and Wind River Basins of Wyoming. This new sample documents greater taxonomic diversity of omomyids during the early Eocene and contributes to our understanding of the phylogeny and adaptations of some of these earliest North American primates. A new middle Wasatchian (Lysitean) anaptomorphine, Anemorhysis savagei, n. sp., is structurally intermediate between Teilhardina americana and other species of Anemorhysis and may be a sister group of other Anemorhysis and Trogolemur. Body size estimates for Anemorhysis, Tetonoides, Trogolemur, and Teilhardina americana indicate that these animals were extremely small, probably less than 50 grams. Analysis of relative shearing potential of lower molars of these taxa indicates that some were primarily insectivorous, some primarily frugivorous, and some may have been more mixed feeders. Anaptomorphines did not develop the extremes of molar specialization for frugivory or insectivory seen in extant prosimians. Incisor enlargement does not appear to be associated with specialization in either fruits or insects but may have been an adaptation for specialized grooming or food manipulation.
Invited Article: A review of haptic optical tweezers for an interactive microworld exploration

NASA Astrophysics Data System (ADS)

Pacoret, Cécile; Régnier, Stéphane

2013-08-01

This paper is the first review of haptic optical tweezers, a new technique which associates force feedback teleoperation with optical tweezers. This technique allows users to explore the microworld by sensing and exerting picoNewton-scale forces with trapped microspheres. Haptic optical tweezers also allow improved dexterity of micromanipulation and micro-assembly. One of the challenges of this technique is to sense and magnify picoNewton-scale forces by a factor of 1012 to enable human operators to perceive interactions that they have never experienced before, such as adhesion phenomena, extremely low inertia, and high frequency dynamics of extremely small objects. The design of optical tweezers for high quality haptic feedback is challenging, given the requirements for very high sensitivity and dynamic stability. The concept, design process, and specification of optical tweezers reviewed here are focused on those intended for haptic teleoperation. In this paper, two new specific designs as well as the current state-of-the-art are presented. Moreover, the remaining important issues are identified for further developments. The initial results obtained are promising and demonstrate that optical tweezers have a significant potential for haptic exploration of the microworld. Haptic optical tweezers will become an invaluable tool for force feedback micromanipulation of biological samples and nano- and micro-assembly parts.
Aerodynamic levitation, supercooled liquids and glass formation

DOE PAGES

Benmore, C. J.; Weber, J. K. R.

2017-05-04

Containerless processing or ‘levitation’ is a valuable tool for the synthesis and characterization of materials, particularly at extreme temperatures and under non-equilibrium conditions. The method enables formation of novel glasses, amorphous phases, and metastable crystalline forms that are not easily accessed when nucleation and growth can readily occur at a container interface. Removing the container enables the use of a wide variety of process atmospheres to modify a materials structure and properties. In the past decade levitation methods, including acoustic, aerodynamic, electromagnetic, and electrostatic, have become well established sample environments at X-ray synchrotron and neutron sources. This article briefly reviewsmore » the methods and then focuses on the application of aerodynamic levitation to synthesize and study new materials. This is presented in conjunction with non-contact probes used to investigate the atomic structure and to measure the properties of materials at extreme temperatures. The use of aerodynamic levitation in research using small and wide-angle X-ray diffraction, XANES, and neutron scattering are discussed in the context of technique development. The use of the containerless methods to investigate thermophysical properties is also considered. We argue that structural motifs and in the liquid state can potentially lead to the fabrication of materials, whose properties would differ substantially from their well known crystalline forms.« less
Understanding the importance of transient resonances in extreme mass ratio inspirals

NASA Astrophysics Data System (ADS)

Berry, C. P. L.; Cole, R. H.; Cañizares, P.; Gair, J. R.

2017-05-01

Extreme mass ratio inspirals (EMRIs) occur when a compact object orbits a much larger one, like a solar-mass black hole around a supermassive black hole. The orbit has 3 frequencies which evolve through the inspiral. If the orbital radial frequency and polar frequency become commensurate, the system passes through a transient resonance. Evolving through resonance causes a jump in the evolution of the orbital parameters. We study these jumps and their impact on EMRI gravitational-wave detection. Jumps are smaller for lower eccentricity orbits; since most EMRIs have small eccentricities when passing through resonances, we expect that the impact on detection will be small. Neglecting the effects of transient resonances leads to a loss of ∼ 4% of detectable signals for an astrophysically motivated population of EMRIs.
Spatial variation of statistical properties of extreme water levels along the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Pindsoo, Katri; Soomere, Tarmo; Rocha, Eugénio

2016-04-01

Most of existing projections of future extreme water levels rely on the use of classic generalised extreme value distributions. The choice to use a particular distribution is often made based on the absolute value of the shape parameter of the Generalise Extreme Value distribution. If this parameter is small, the Gumbel distribution is most appropriate while in the opposite case the Weibull or Frechet distribution could be used. We demonstrate that the alongshore variation in the statistical properties of numerically simulated high water levels along the eastern coast of the Baltic Sea is so large that the use of a single distribution for projections of extreme water levels is highly questionable. The analysis is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. The output of the Rossby Centre Ocean model is sampled with a resolution of 6 h and the output of the circulation model NEMO with a resolution of 1 h. As the maxima of water levels of subsequent years may be correlated in the Baltic Sea, we also employ maxima for stormy seasons. We provide a detailed analysis of spatial variation of the parameters of the family of extreme value distributions along an approximately 600 km long coastal section from the north-western shore of Latvia in the Baltic Proper until the eastern Gulf of Finland. The parameters are evaluated using maximum likelihood method and method of moments. The analysis also covers the entire Gulf of Riga. The core parameter of this family of distributions, the shape parameter of the Generalised Extreme Value distribution, exhibits extensive variation in the study area. Its values evaluated using the Hydrognomon software and maximum likelihood method, vary from about -0.1 near the north-western coast of Latvia in the Baltic Proper up to about 0.05 in the eastern Gulf of Finland. This parameter is very close to zero near Tallinn in the western Gulf of Finland. Thus, it is natural that the Gumbel distribution gives adequate projections of extreme water levels for the vicinity of Tallinn. More importantly, this feature indicates that the use of a single distribution for the projections of extreme water levels and their return periods for the entire Baltic Sea coast is inappropriate. The physical reason is the interplay of the complex shape of large subbasins (such as the Gulf of Riga and Gulf of Finland) of the sea and highly anisotropic wind regime. The 'impact' of this anisotropy on the statistics of water level is amplified by the overall anisotropy of the distributions of the frequency of occurrence of high and low water levels. The most important conjecture is that long-term behaviour of water level extremes in different coastal sections of the Baltic Sea may be fundamentally different.
Proposal of ultrasonic-assisted mid-infrared spectroscopy for incorporating into daily life like smart-toilet and non-invasive blood glucose sensor

NASA Astrophysics Data System (ADS)

Kitazaki, Tomoya; Mori, Keita; Yamamoto, Naoyuki; Wang, Congtao; Kawashima, Natsumi; Ishimaru, Ichiro

2017-07-01

We proposed the extremely compact beans-size snap-shot mid-infrared spectroscopy that will be able to be built in smartphones. And also the easy preparation method of thin-film samples generated by ultrasonic standing wave is proposed. Mid-infrared spectroscopy is able to identify material components and estimate component concentrations quantitatively from absorption spectra. But conventional spectral instruments were very large-size and too expensive to incorporate into daily life. And preparations of thin-film sample were very troublesome task. Because water absorption in mid-infrared lights is very strong, moisture-containing-sample thickness should be less than 100[μm]. Thus, midinfrared spectroscopy has been utilized only by analytical experts in their laboratories. Because ultrasonic standing wave is compressional wave, we can generate periodical refractive-index distributions inside of samples. A high refractiveindex plane is correspond to a reflection boundary. When we use a several MHz ultrasonic transducer, the distance between sample surface and generated first node become to be several ten μm. Thus, the double path of this distance is correspond to sample thickness. By combining these two proposed methods, as for liquid samples, urinary albumin and glucose concentrations will be able to be measured inside of toilet. And as for solid samples, by attaching these apparatus to earlobes, the enhancement of reflection lights from near skin surface will create a new path to realize the non-invasive blood glucose sensor. Using the small ultrasonic-transducer whose diameter was 10[mm] and applied voltage 8[V], we detected the internal reflection lights from colored water as liquid sample and acrylic board as solid sample.
On the monitoring and prediction of flash floods in small and medium-sized catchments - the EXTRUSO project

NASA Astrophysics Data System (ADS)

Wiemann, Stefan; Eltner, Anette; Sardemann, Hannes; Spieler, Diana; Singer, Thomas; Thanh Luong, Thi; Janabi, Firas Al; Schütze, Niels; Bernard, Lars; Bernhofer, Christian; Maas, Hans-Gerd

2017-04-01

Flash floods regularly cause severe socio-economic damage worldwide. In parallel, climate change is very likely to increase the number of such events, due to an increasing frequency of extreme precipitation events (EASAC 2013). Whereas recent work primarily addresses the resilience of large catchment areas, the major impact of hydro-meteorological extremes caused by heavy precipitation is on small areas. Those are very difficult to observe and predict, due to sparse monitoring networks and only few means for hydro-meteorological modelling, especially in small catchment areas. The objective of the EXTRUSO project is to identify and implement appropriate means to close this gap by an interdisciplinary approach, combining comprehensive research expertise from meteorology, hydrology, photogrammetry and geoinformatics. The project targets innovative techniques for achieving spatio-temporal densified monitoring and simulations for the analysis, prediction and warning of local hydro-meteorological extreme events. The following four aspects are of particular interest: 1. The monitoring, analysis and combination of relevant hydro-meteorological parameters from various sources, including existing monitoring networks, ground radar, specific low-cost sensors and crowdsourcing. 2. The determination of relevant hydro-morphological parameters from different photogrammetric sensors (e.g. camera, laser scanner) and sensor platforms (e.g. UAV (unmanned aerial vehicle) and UWV (unmanned water vehicle)). 3. The continuous hydro-meteorological modelling of precipitation, soil moisture and water flows by means of conceptual and data-driven modelling. 4. The development of a collaborative, web-based service infrastructure as an information and communication point, especially in the case of an extreme event. There are three major applications for the planned information system: First, the warning of local extreme events for the population in potentially affected areas, second, the support for decision makers and emergency responders in the case of an event and, third, the development of open, interoperable tools for other researchers to be applied and further developed. The test area of the project is the Free State of Saxony (Germany) with a number of small and medium catchment areas. However, the whole system, comprising models, tools and sensor setups, is planned to be transferred and tested in other areas, within and outside Europe, as well. The team working on the project consists of eight researchers, including five PhD students and three postdocs. The EXTRUSO project is funded by the European Social Fund (ESF grant nr. 100270097) with a project duration of three years until June 2019. EASAC (2013): Trends in extreme weather events in Europe: implications for national and European Union adaption strategies. European Academies Science Advisory Council. Policy report 22, November 2013 The EXTRUSO project is funded by the European Social Fund (ESF), grant nr. 100270097

Scalable Performance Measurement and Analysis

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

Gamblin, Todd

2009-01-01

Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number ofmore » tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.« less
Climatic extremes improve predictions of spatial patterns of tree species

USGS Publications Warehouse

Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C.; Meier, E.S.; Thuiller, W.; Guisan, Antoine; Schmatz, D.R.; Pearman, P.B.

2009-01-01

Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.
Scattering Tools for Nanostructure Phonon Engineering

DTIC Science & Technology

2013-09-25

characterization of phonons in nanomaterials, such as Raman scattering, are sensitive only to phonon modes with wavevectors of extremely small magnitude...Fundamentally the wavevectors that can be probed by Raman scattering are limited by the small momentum of photons in the visible spectrum. Our work...serious characterization challenge because existing experimental techniques for the characterization of phonons in nanomaterials, such as Raman
Statistical analysis of stream water-quality data and sampling network design near Oklahoma City, central Oklahoma, 1977-1999

USGS Publications Warehouse

Brigham, Mark E.; Payne, Gregory A.; Andrews, William J.; Abbott, Marvin M.

2002-01-01

The sampling network was evaluated with respect to areal coverage, sampling frequency, and analytical schedules. Areal coverage could be expanded to include one additional watershed that is not part of the current network. A new sampling site on the North Canadian River might be useful because of expanding urbanization west of the city, but sampling at some other sites could be discontinued or reduced based on comparisons of data between the sites. Additional real-time or periodic monitoring for dissolved oxygen may be useful to prevent anoxic conditions in pools behind new low-water dams. The sampling schedules, both monthly and quarterly, are adequate to evaluate trends, but additional sampling during flow extremes may be needed to quantify loads and evaluate water-quality during flow extremes. Emerging water-quality issues may require sampling for volatile organic compounds, sulfide, total phosphorus, chlorophyll-a, Esherichia coli, and enterococci, as well as use of more sensitive laboratory analytical methods for determination of cadmium, mercury, lead, and silver.
RAPID Assessment of Extreme Reservoir Sedimentation Resulting from the September 2013 Flood, North St. Vrain Creek, CO

NASA Astrophysics Data System (ADS)

Rathburn, S. L.; McElroy, B. J.; Wohl, E.; Sutfin, N. A.; Huson, K.

2014-12-01

During mid-September 2013, approximately 360 mm of precipitation fell in the headwaters of the North St. Vrain drainage basin, Front Range, CO. Debris flows on steep hillslopes and extensive flooding along North St. Vrain Creek resulted in extreme sedimentation within Ralph Price Reservoir, municipal water supply for the City of Longmont. The event allows comparison of historical sedimentation with that of an unusually large flood because 1) no reservoir flushing has been conducted since dam construction, 2) reservoir stratigraphy chronicles uninterrupted delta deposition, and 3) this is the only on-channel reservoir with unimpeded, natural sediment flux from the Continental Divide to the mountain front in a basin with no significant historic flow modifications and land use impacts. Assessing the flood-related sedimentation prior to any dredging activities included coring the reservoir delta, a bathymetric survey of the delta, resistivity and ground penetrating radar surveys of the subaerial inlet deposit, and surveying tributary deposits. Over the 44-year life of the reservoir, two-thirds of the delta sedimentation is attributed to extreme discharges from the September 2013 storm. Total storm-derived reservoir sedimentation is approximately 275,000 m3, with 81% of that within the gravel-dominated inlet and 17% in the delta. Volumes of deposition within reservoir tributary inlets is negatively correlated with contributing area, possibly due to a lack of storage in these small basins (1-5 km2). Flood-related reservoir sedimentation will be compared to other research quantifying volumes from slope failures evident on post-storm lidar. Analysis of delta core samples will quantify organic carbon flux associated with the extreme discharge and develop a chronology of flood and fire disturbances for North St. Vrain basin. Applications of similar techniques are planned for two older Front Range reservoirs affected by the September flooding to fill knowledge gaps about event-based sedimentation and to expand these rates to annual and decadal scales.
Do regional methods really help reduce uncertainties in flood frequency analyses?

NASA Astrophysics Data System (ADS)

Cong Nguyen, Chi; Payrastre, Olivier; Gaume, Eric

2013-04-01

Flood frequency analyses are often based on continuous measured series at gauge sites. However, the length of the available data sets is usually too short to provide reliable estimates of extreme design floods. To reduce the estimation uncertainties, the analyzed data sets have to be extended either in time, making use of historical and paleoflood data, or in space, merging data sets considered as statistically homogeneous to build large regional data samples. Nevertheless, the advantage of the regional analyses, the important increase of the size of the studied data sets, may be counterbalanced by the possible heterogeneities of the merged sets. The application and comparison of four different flood frequency analysis methods to two regions affected by flash floods in the south of France (Ardèche and Var) illustrates how this balance between the number of records and possible heterogeneities plays in real-world applications. The four tested methods are: (1) a local statistical analysis based on the existing series of measured discharges, (2) a local analysis valuating the existing information on historical floods, (3) a standard regional flood frequency analysis based on existing measured series at gauged sites and (4) a modified regional analysis including estimated extreme peak discharges at ungauged sites. Monte Carlo simulations are conducted to simulate a large number of discharge series with characteristics similar to the observed ones (type of statistical distributions, number of sites and records) to evaluate to which extent the results obtained on these case studies can be generalized. These two case studies indicate that even small statistical heterogeneities, which are not detected by the standard homogeneity tests implemented in regional flood frequency studies, may drastically limit the usefulness of such approaches. On the other hand, these result show that the valuation of information on extreme events, either historical flood events at gauged sites or estimated extremes at ungauged sites in the considered region, is an efficient way to reduce uncertainties in flood frequency studies.
The Climatology of Extreme Surge-Producing Extratropical Cyclones in Observations and Models

NASA Astrophysics Data System (ADS)

Catalano, A. J.; Broccoli, A. J.; Kapnick, S. B.

2016-12-01

Extreme coastal storms devastate heavily populated areas around the world by producing powerful winds that can create a large storm surge. Both tropical and extratropical cyclones (ETCs) occur over the northwestern Atlantic Ocean, and the risks associated with ETCs can be just as severe as those associated with tropical storms (e.g. high winds, storm surge). At The Battery in New York City, 17 of the 20 largest storm surge events were a consequence of extratropical cyclones (ETCs), which are more prevalent than tropical cyclones in the northeast region of the United States. Therefore, we analyze the climatology of ETCs that are capable of producing a large storm surge along the northeastern coast of the United States. For a historical analysis, water level data was collected from National Oceanic and Atmospheric Administration (NOAA) tide gauges at three separate locations (Sewell's Pt., VA, The Battery, NY, and Boston, MA). We perform a k-means cluster analysis of sea level pressure from the ECMWF 20th Century Reanalysis dataset (ERA-20c) to explore the natural sets of observed storms with similar characteristics. We then composite cluster results with features of atmospheric circulation to observe the influence of interannual and multidecadal variability such as the North Atlantic Oscillation. Since observational records contain a small number of well-documented ETCs, the capability of a high-resolution coupled climate model to realistically simulate such extreme coastal storms will also be assessed. Global climate models provide a means of simulating a much larger sample of extreme events, allowing for better resolution of the tail of the distribution. We employ a tracking algorithm to identify ETCs in a multi-century simulation under present-day conditions. Quantitative comparisons of cyclolysis, cyclogenesis, and cyclone densities of simulated ETCs and storms from recent history (using reanalysis products) are conducted.
Why do people buy dogs with potential welfare problems related to extreme conformation and inherited disease? A representative study of Danish owners of four small dog breeds

PubMed Central

Kondrup, S. V.; Bennett, P. C.; Forkman, B.; Meyer, I; Proschowsky, H. F.; Serpell, J. A.; Lund, T. B.

2017-01-01

A number of dog breeds suffer from welfare problems due to extreme phenotypes and high levels of inherited diseases but the popularity of such breeds is not declining. Using a survey of owners of two popular breeds with extreme physical features (French Bulldog and Chihuahua), one with a high load of inherited diseases not directly related to conformation (Cavalier King Charles Spaniel), and one representing the same size range but without extreme conformation and with the same level of disease as the overall dog population (Cairn Terrier), we investigated this seeming paradox. We examined planning and motivational factors behind acquisition of the dogs, and whether levels of experienced health and behavior problems were associated with the quality of the owner-dog relationship and the intention to re-procure a dog of the same breed. Owners of each of the four breeds (750/breed) were randomly drawn from a nationwide Danish dog registry and invited to participate. Of these, 911 responded, giving a final sample of 846. There were clear differences between owners of the four breeds with respect to degree of planning prior to purchase, with owners of Chihuahuas exhibiting less. Motivations behind choice of dog were also different. Health and other breed attributes were more important to owners of Cairn Terriers, whereas the dog’s personality was reported to be more important for owners of French Bulldogs and Cavalier King Charles Spaniels but less important for Chihuahua owners. Higher levels of health and behavior problems were positively associated with a closer owner-dog relationship for owners of Cavalier King Charles Spaniels and Chihuahuas but, for owners of French Bulldogs, high levels of problems were negatively associated with an intention to procure the same breed again. In light of these findings, it appears less paradoxical that people continue to buy dogs with welfare problems. PMID:28234931
Why do people buy dogs with potential welfare problems related to extreme conformation and inherited disease? A representative study of Danish owners of four small dog breeds.

PubMed

Sandøe, P; Kondrup, S V; Bennett, P C; Forkman, B; Meyer, I; Proschowsky, H F; Serpell, J A; Lund, T B

2017-01-01

A number of dog breeds suffer from welfare problems due to extreme phenotypes and high levels of inherited diseases but the popularity of such breeds is not declining. Using a survey of owners of two popular breeds with extreme physical features (French Bulldog and Chihuahua), one with a high load of inherited diseases not directly related to conformation (Cavalier King Charles Spaniel), and one representing the same size range but without extreme conformation and with the same level of disease as the overall dog population (Cairn Terrier), we investigated this seeming paradox. We examined planning and motivational factors behind acquisition of the dogs, and whether levels of experienced health and behavior problems were associated with the quality of the owner-dog relationship and the intention to re-procure a dog of the same breed. Owners of each of the four breeds (750/breed) were randomly drawn from a nationwide Danish dog registry and invited to participate. Of these, 911 responded, giving a final sample of 846. There were clear differences between owners of the four breeds with respect to degree of planning prior to purchase, with owners of Chihuahuas exhibiting less. Motivations behind choice of dog were also different. Health and other breed attributes were more important to owners of Cairn Terriers, whereas the dog's personality was reported to be more important for owners of French Bulldogs and Cavalier King Charles Spaniels but less important for Chihuahua owners. Higher levels of health and behavior problems were positively associated with a closer owner-dog relationship for owners of Cavalier King Charles Spaniels and Chihuahuas but, for owners of French Bulldogs, high levels of problems were negatively associated with an intention to procure the same breed again. In light of these findings, it appears less paradoxical that people continue to buy dogs with welfare problems.
Extreme-value dependence: An application to exchange rate markets

NASA Astrophysics Data System (ADS)

Fernandez, Viviana

2007-04-01

Extreme value theory (EVT) focuses on modeling the tail behavior of a loss distribution using only extreme values rather than the whole data set. For a sample of 10 countries with dirty/free float regimes, we investigate whether paired currencies exhibit a pattern of asymptotic dependence. That is, whether an extremely large appreciation or depreciation in the nominal exchange rate of one country might transmit to another. In general, after controlling for volatility clustering and inertia in returns, we do not find evidence of extreme-value dependence between paired exchange rates. However, for asymptotic-independent paired returns, we find that tail dependency of exchange rates is stronger under large appreciations than under large depreciations.
ETTF - Extreme Temperature Translation Furnace experiment

NASA Image and Video Library

1996-09-23

STS79-E-5275 (16 - 26 September 1996) --- Aboard the Spacehab double module in the Space Shuttle Atlantis' cargo bay, astronaut Jerome (Jay) Apt, mission specialist, checks a sample from the Extreme Temperature Translation Furnace (ETTF) experiment. The photograph was taken with the Electronic Still Camera (ESC).
Overrepresentation of extreme events in decision making reflects rational use of cognitive resources.

PubMed

Lieder, Falk; Griffiths, Thomas L; Hsu, Ming

2018-01-01

People's decisions and judgments are disproportionately swayed by improbable but extreme eventualities, such as terrorism, that come to mind easily. This article explores whether such availability biases can be reconciled with rational information processing by taking into account the fact that decision makers value their time and have limited cognitive resources. Our analysis suggests that to make optimal use of their finite time decision makers should overrepresent the most important potential consequences relative to less important, put potentially more probable, outcomes. To evaluate this account, we derive and test a model we call utility-weighted sampling. Utility-weighted sampling estimates the expected utility of potential actions by simulating their outcomes. Critically, outcomes with more extreme utilities have a higher probability of being simulated. We demonstrate that this model can explain not only people's availability bias in judging the frequency of extreme events but also a wide range of cognitive biases in decisions from experience, decisions from description, and memory recall. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Exome sequencing of extreme phenotypes identifies DCTN4 as a modifier of chronic Pseudomonas aeruginosa infection in cystic fibrosis.

PubMed

Emond, Mary J; Louie, Tin; Emerson, Julia; Zhao, Wei; Mathias, Rasika A; Knowles, Michael R; Wright, Fred A; Rieder, Mark J; Tabor, Holly K; Nickerson, Deborah A; Barnes, Kathleen C; Gibson, Ronald L; Bamshad, Michael J

2012-07-08

Exome sequencing has become a powerful and effective strategy for the discovery of genes underlying Mendelian disorders. However, use of exome sequencing to identify variants associated with complex traits has been more challenging, partly because the sample sizes needed for adequate power may be very large. One strategy to increase efficiency is to sequence individuals who are at both ends of a phenotype distribution (those with extreme phenotypes). Because the frequency of alleles that contribute to the trait are enriched in one or both phenotype extremes, a modest sample size can potentially be used to identify novel candidate genes and/or alleles. As part of the National Heart, Lung, and Blood Institute (NHLBI) Exome Sequencing Project (ESP), we used an extreme phenotype study design to discover that variants in DCTN4, encoding a dynactin protein, are associated with time to first P. aeruginosa airway infection, chronic P. aeruginosa infection and mucoid P. aeruginosa in individuals with cystic fibrosis.
Risk factors for lower extremity injury: a review of the literature

PubMed Central

Murphy, D; Connolly, D; Beynnon, B

2003-01-01

Prospective studies on risk factors for lower extremity injury are reviewed. Many intrinsic and extrinsic risk factors have been implicated; however, there is little agreement with respect to the findings. Future prospective studies are needed using sufficient sample sizes of males and females, including collection of exposure data, and using established methods for identifying and classifying injury severity to conclusively determine addtional risk factors for lower extremity injury. PMID:12547739
Ibritumomab Injection

MedlinePlus

... albumin (a product that is made from live donor blood). Although there is a extremely small chance that ... develop these antibodies, you may have an allergic reaction when you take medications made from murine proteins, ...
A Descriptive Study of Pediatric Injury Patterns from the National Automotive Sampling System

PubMed Central

Newgard, C; Jolly, BT

1998-01-01

This study describes information from the National Automotive Sampling System for injury mechanisms in the pediatric age group (age 0–16). The total number of pediatric cases in the NASS database for this three year sampling period is 2141(weighted 591,084). No restraint use was identified in 23–43% of the children. For age < 1yr, 60% of patients suffer a facial injury. Head injuries make up only 10% of the total injuries, but are severe. For those age 1–4 yrs abdominal injuries and lower extremity injuries begin to appear. For those age 5–10 yrs, the predominant change over younger occupants is the proportion of spinal injuries. By age 11–16, injuries to the spine, upper extremities, and lower extremities outnumber injuries to the face and head. However, in this population, the greatest proportions of AIS 3–5 injuries still occur to the head and abdomen.
Small Fermi surfaces of PtSn4 and Pt3In7

NASA Astrophysics Data System (ADS)

Yara, T.; Kakihana, M.; Nishimura, K.; Hedo, M.; Nakama, T.; Ōnuki, Y.; Harima, H.

2018-05-01

An extremely large magnetoresistance of PtSn4 has been recently observed and discussed from a viewpoint of de Haas-van Alphen (dHvA) oscillations and theoretical small Fermi surfaces. We have studied precisely the Fermi surfaces by measuring angular dependences of dHvA frequencies and have also carried out the full potential LAPW band calculation. Furthermore, small Fermi surfaces have been detected in another Pt-based compound of Pt3In7 with the cubic structure.
Endophenotype Best Practices

PubMed Central

Iacono, William G.; Malone, Stephen M.; Vrieze, Scott I.

2016-01-01

This review examines the current state of electrophysiological endophenotype research and recommends best practices that are based on knowledge gleaned from the last decade of molecular genetic research with complex traits. Endophenotype research is being oversold for its potential to help discover psychopathology relevant genes using the types of small samples feasible for electrophysiological research. This is largely because the genetic architecture of endophenotypes appears to be very much like that of behavioral traits and disorders: they are complex, influenced by many variants (e.g., tens of thousands) within many genes, each contributing a very small effect. Out of over 40 electrophysiological endophenotypes covered by our review, only resting heart, a measure that has received scant advocacy as an endophenotype, emerges as an electrophysiological variable with verified associations with molecular genetic variants. To move the field forward, investigations designed to discover novel variants associated with endophenotypes will need extremely large samples best obtained by forming consortia and sharing data obtained from genome wide arrays. In addition, endophenotype research can benefit from successful molecular genetic studies of psychopathology by examining the degree to which these verified psychopathology-relevant variants are also associated with an endophenotype, and by using knowledge about the functional significance of these variants to generate new endophenotypes. Even without molecular genetic associations, endophenotypes still have value in studying the development of disorders in unaffected individuals at high genetic risk, constructing animal models, and gaining insight into neural mechanisms that are relevant to clinical disorder. PMID:27473600
A random sampling approach for robust estimation of tissue-to-plasma ratio from extremely sparse data.

PubMed

Chu, Hui-May; Ette, Ene I

2005-09-02

his study was performed to develop a new nonparametric approach for the estimation of robust tissue-to-plasma ratio from extremely sparsely sampled paired data (ie, one sample each from plasma and tissue per subject). Tissue-to-plasma ratio was estimated from paired/unpaired experimental data using independent time points approach, area under the curve (AUC) values calculated with the naïve data averaging approach, and AUC values calculated using sampling based approaches (eg, the pseudoprofile-based bootstrap [PpbB] approach and the random sampling approach [our proposed approach]). The random sampling approach involves the use of a 2-phase algorithm. The convergence of the sampling/resampling approaches was investigated, as well as the robustness of the estimates produced by different approaches. To evaluate the latter, new data sets were generated by introducing outlier(s) into the real data set. One to 2 concentration values were inflated by 10% to 40% from their original values to produce the outliers. Tissue-to-plasma ratios computed using the independent time points approach varied between 0 and 50 across time points. The ratio obtained from AUC values acquired using the naive data averaging approach was not associated with any measure of uncertainty or variability. Calculating the ratio without regard to pairing yielded poorer estimates. The random sampling and pseudoprofile-based bootstrap approaches yielded tissue-to-plasma ratios with uncertainty and variability. However, the random sampling approach, because of the 2-phase nature of its algorithm, yielded more robust estimates and required fewer replications. Therefore, a 2-phase random sampling approach is proposed for the robust estimation of tissue-to-plasma ratio from extremely sparsely sampled data.
Extreme isotopic variations in the upper mantle: evidence from Ronda

NASA Astrophysics Data System (ADS)

Reisberg, Laurie; Zindler, Alan

1986-12-01

The Ronda Ultramafic Complex in southern Spain represents a piece of the Earth's mantle which has been tectonically emplaced into the crust. Nd and Sr isotopic analyses are presented for leached, hand-picked Cr-diopside separates prepared from 15 rock and 18 river sediment samples from Ronda. These results demonstrate that within this small, contiguous body there exists the entire range of Nd isotopic compositions, and much of the range of Sr compositions, found in rocks derived from the sub-oceanic mantle. The sediment cpx samples show that the average isotopic composition of the massif becomes progressively less "depleted" moving from SW to NE along the long axis of the massif. The rock cpx samples document 143Nd/ 144Nd variations from 0.5129 to 0.5126 and 87Sr/ 86Sr variations from 0.7031 to 0.7039 within a uniform outcrop less than 10 m in extent. Thus, extreme isotopic fluctuations exist over a wide range of wavelengths. Sr and Nd isotopes are generally inversely correlated, forming a trend on a Nd-Sr diagram that sharply crosscuts that of the "mantle array". Many of the 143Nd/ 144Nd values, and all of the Sm/Nd values, from one section of the massif are lower than that SCV015SCV0 of the bulk earth, implying that this region existed, or was influenced by a component which existed, in a LREE-enriched environment for a significant period of time. Among the sediment cpxs there is a positive correlation between 143Nd/ 144Nd and 147Sm/ 144Nd. The rock cpx separates display considerably more scatter. A simple, single-stage differentiation event starting with a uniform mantle source cannot explain these results. At least one episode of mixing with a LREE-enriched component is required. If these results from Ronda are typical of the upper mantle, basalts with different isotopic compositions need not derive from spatially separated mantle sources.

On Shaft Data Acquisition System (OSDAS)

NASA Technical Reports Server (NTRS)

Pedings, Marc; DeHart, Shawn; Formby, Jason; Naumann, Charles

2012-01-01

On Shaft Data Acquisition System (OSDAS) is a rugged, compact, multiple-channel data acquisition computer system that is designed to record data from instrumentation while operating under extreme rotational centrifugal or gravitational acceleration forces. This system, which was developed for the Heritage Fuel Air Turbine Test (HFATT) program, addresses the problem of recording multiple channels of high-sample-rate data on most any rotating test article by mounting the entire acquisition computer onboard with the turbine test article. With the limited availability of slip ring wires for power and communication, OSDAS utilizes its own resources to provide independent power and amplification for each instrument. Since OSDAS utilizes standard PC technology as well as shared code interfaces with the next-generation, real-time health monitoring system (SPARTAA Scalable Parallel Architecture for Real Time Analysis and Acquisition), this system could be expanded beyond its current capabilities, such as providing advanced health monitoring capabilities for the test article. High-conductor-count slip rings are expensive to purchase and maintain, yet only provide a limited number of conductors for routing instrumentation off the article and to a stationary data acquisition system. In addition to being limited to a small number of instruments, slip rings are prone to wear quickly, and introduce noise and other undesirable characteristics to the signal data. This led to the development of a system capable of recording high-density instrumentation, at high sample rates, on the test article itself, all while under extreme rotational stress. OSDAS is a fully functional PC-based system with 48 channels of 24-bit, high-sample-rate input channels, phase synchronized, with an onboard storage capacity of over 1/2-terabyte of solid-state storage. This recording system takes a novel approach to the problem of recording multiple channels of instrumentation, integrated with the test article itself, packaged in a compact/rugged form factor, consuming limited power, all while rotating at high turbine speeds.
The cost of large numbers of hypothesis tests on power, effect size and sample size.

PubMed

Lazzeroni, L C; Ray, A

2012-01-01

Advances in high-throughput biology and computer science are driving an exponential increase in the number of hypothesis tests in genomics and other scientific disciplines. Studies using current genotyping platforms frequently include a million or more tests. In addition to the monetary cost, this increase imposes a statistical cost owing to the multiple testing corrections needed to avoid large numbers of false-positive results. To safeguard against the resulting loss of power, some have suggested sample sizes on the order of tens of thousands that can be impractical for many diseases or may lower the quality of phenotypic measurements. This study examines the relationship between the number of tests on the one hand and power, detectable effect size or required sample size on the other. We show that once the number of tests is large, power can be maintained at a constant level, with comparatively small increases in the effect size or sample size. For example at the 0.05 significance level, a 13% increase in sample size is needed to maintain 80% power for ten million tests compared with one million tests, whereas a 70% increase in sample size is needed for 10 tests compared with a single test. Relative costs are less when measured by increases in the detectable effect size. We provide an interactive Excel calculator to compute power, effect size or sample size when comparing study designs or genome platforms involving different numbers of hypothesis tests. The results are reassuring in an era of extreme multiple testing.
Extremely high genetic diversity in a single tumor points to prevalence of non-Darwinian cell evolution.

PubMed

Ling, Shaoping; Hu, Zheng; Yang, Zuyu; Yang, Fang; Li, Yawei; Lin, Pei; Chen, Ke; Dong, Lili; Cao, Lihua; Tao, Yong; Hao, Lingtong; Chen, Qingjian; Gong, Qiang; Wu, Dafei; Li, Wenjie; Zhao, Wenming; Tian, Xiuyun; Hao, Chunyi; Hungate, Eric A; Catenacci, Daniel V T; Hudson, Richard R; Li, Wen-Hsiung; Lu, Xuemei; Wu, Chung-I

2015-11-24

The prevailing view that the evolution of cells in a tumor is driven by Darwinian selection has never been rigorously tested. Because selection greatly affects the level of intratumor genetic diversity, it is important to assess whether intratumor evolution follows the Darwinian or the non-Darwinian mode of evolution. To provide the statistical power, many regions in a single tumor need to be sampled and analyzed much more extensively than has been attempted in previous intratumor studies. Here, from a hepatocellular carcinoma (HCC) tumor, we evaluated multiregional samples from the tumor, using either whole-exome sequencing (WES) (n = 23 samples) or genotyping (n = 286) under both the infinite-site and infinite-allele models of population genetics. In addition to the many single-nucleotide variations (SNVs) present in all samples, there were 35 "polymorphic" SNVs among samples. High genetic diversity was evident as the 23 WES samples defined 20 unique cell clones. With all 286 samples genotyped, clonal diversity agreed well with the non-Darwinian model with no evidence of positive Darwinian selection. Under the non-Darwinian model, MALL (the number of coding region mutations in the entire tumor) was estimated to be greater than 100 million in this tumor. DNA sequences reveal local diversities in small patches of cells and validate the estimation. In contrast, the genetic diversity under a Darwinian model would generally be orders of magnitude smaller. Because the level of genetic diversity will have implications on therapeutic resistance, non-Darwinian evolution should be heeded in cancer treatments even for microscopic tumors.
Utility of Cytospin and Cell block Technology in Evaluation of Body Fluids and Urine Samples: A Comparative Study

PubMed Central

Qamar, Irmeen; Rehman, Suhailur; Mehdi, Ghazala; Maheshwari, Veena; Ansari, Hena A.; Chauhan, Sunanda

2018-01-01

Background: Cytologic examination of body fluids commonly involves the use of direct or sediment smears, cytocentrifuge preparations, membrane filter preparations, or cell block sections. Cytospin and cell block techniques are extremely useful in improving cell yield of thin serous effusions and urine samples, and ensure high diagnostic efficacy. Materials and Methods: We studied cytospin preparations and cell block sections prepared from 180 samples of body fluids and urine samples to compare the relative efficiency of cell retrieval, preservation of cell morphology, ease of application of special stains, and diagnostic efficacy. Samples were collected and processed to prepare cytospin smears and cell block sections. Results: We observed that overall, cell yield and preservation of individual cell morphology were better in cytospin preparations as compared to cell blocks, while preservation of architectural pattern was better in cell block sections. The number of suspicious cases also decreased on cell block sections, with increased detection of malignancy. It was difficult to prepare cell blocks from urine samples due to low cellularity. Conclusions: Cytospin technology is a quick, efficient, and cost-effective method of increasing cell yield in hypocellular samples, with better preservation of cell morphology. Cell blocks are better prepared from high cellularity fluids; however, tissue architecture is better studied, with improved rate of diagnosis and decrease in ambiguous results. Numerous sections can be prepared from a small amount of material. Special stains and immunochemical stains can be easily applied to cell blocks. It also provides a source of archival material. PMID:29643653
Exploring the Utilization of Low-Pressure, Piston-Cylinder Experiments to Determine the Bulk Compositions of Finite, Precious Materials

NASA Technical Reports Server (NTRS)

Vander Kaaden, K. E.; McCubbin, F. M.; Harrington, A. D.

2017-01-01

Determining the bulk composition of precious materials with a finite mass (e.g., meteorite samples) is extremely important in the fields of Earth and Planetary Science. From meteorite studies we are able to place constraints on large scale planetary processes like global differentiation and subsequent volcanism, as well as smaller scale processes like crystallization in a magma chamber or sedimentary compaction at the surface. However, with meteorite samples in particular, far too often we are limited by how precious the sample is as well as its limited mass. In this study, we have utilized aliquots of samples previously studied for toxicological hazards, including both the fresh samples (lunar mare basalt NWA 4734, lunar regolith breccia NWA 7611, martian basalt Tissint, martian regolith breccia NWA 7034, a vestian basalt Berthoud, a vestian regolith breccia NWA 2060, and a terrestrial mid-ocean ridge basalt (MORB)), and those that underwent iron leaching (Tissint, NWA 7034, NWA 4734, MORB). With these small masses of material, we performed low pressure (approx. 0.75 GPa), high temperature (greater than 1600 degrees Celsius) melting experiments. Each sample was analyzed using a JEOL 8530F electron microprobe to determine the bulk composition of the materials that were previously examined. When available, the results of our microprobe data were compared with bulk rock compositions in the literature. The results of this study show that with this technique, only approx. 50 mg of sample is required to accurately determine the bulk composition of the materials of interest.
Extremely high genetic diversity in a single tumor points to prevalence of non-Darwinian cell evolution

PubMed Central

Ling, Shaoping; Hu, Zheng; Yang, Zuyu; Yang, Fang; Li, Yawei; Lin, Pei; Chen, Ke; Dong, Lili; Cao, Lihua; Tao, Yong; Hao, Lingtong; Chen, Qingjian; Gong, Qiang; Wu, Dafei; Li, Wenjie; Zhao, Wenming; Tian, Xiuyun; Hao, Chunyi; Hungate, Eric A.; Catenacci, Daniel V. T.; Hudson, Richard R.; Li, Wen-Hsiung; Lu, Xuemei; Wu, Chung-I

2015-01-01

The prevailing view that the evolution of cells in a tumor is driven by Darwinian selection has never been rigorously tested. Because selection greatly affects the level of intratumor genetic diversity, it is important to assess whether intratumor evolution follows the Darwinian or the non-Darwinian mode of evolution. To provide the statistical power, many regions in a single tumor need to be sampled and analyzed much more extensively than has been attempted in previous intratumor studies. Here, from a hepatocellular carcinoma (HCC) tumor, we evaluated multiregional samples from the tumor, using either whole-exome sequencing (WES) (n = 23 samples) or genotyping (n = 286) under both the infinite-site and infinite-allele models of population genetics. In addition to the many single-nucleotide variations (SNVs) present in all samples, there were 35 “polymorphic” SNVs among samples. High genetic diversity was evident as the 23 WES samples defined 20 unique cell clones. With all 286 samples genotyped, clonal diversity agreed well with the non-Darwinian model with no evidence of positive Darwinian selection. Under the non-Darwinian model, MALL (the number of coding region mutations in the entire tumor) was estimated to be greater than 100 million in this tumor. DNA sequences reveal local diversities in small patches of cells and validate the estimation. In contrast, the genetic diversity under a Darwinian model would generally be orders of magnitude smaller. Because the level of genetic diversity will have implications on therapeutic resistance, non-Darwinian evolution should be heeded in cancer treatments even for microscopic tumors. PMID:26561581
Enabling low-noise null-point scanning thermal microscopy by the optimization of scanning thermal microscope probe through a rigorous theory of quantitative measurement.

PubMed

Hwang, Gwangseok; Chung, Jaehun; Kwon, Ohmyoung

2014-11-01

The application of conventional scanning thermal microscopy (SThM) is severely limited by three major problems: (i) distortion of the measured signal due to heat transfer through the air, (ii) the unknown and variable value of the tip-sample thermal contact resistance, and (iii) perturbation of the sample temperature due to the heat flux through the tip-sample thermal contact. Recently, we proposed null-point scanning thermal microscopy (NP SThM) as a way of overcoming these problems in principle by tracking the thermal equilibrium between the end of the SThM tip and the sample surface. However, in order to obtain high spatial resolution, which is the primary motivation for SThM, NP SThM requires an extremely sensitive SThM probe that can trace the vanishingly small heat flux through the tip-sample nano-thermal contact. Herein, we derive a relation between the spatial resolution and the design parameters of a SThM probe, optimize the thermal and electrical design, and develop a batch-fabrication process. We also quantitatively demonstrate significantly improved sensitivity, lower measurement noise, and higher spatial resolution of the fabricated SThM probes. By utilizing the exceptional performance of these fabricated probes, we show that NP SThM can be used to obtain a quantitative temperature profile with nanoscale resolution independent of the changing tip-sample thermal contact resistance and without perturbation of the sample temperature or distortion due to the heat transfer through the air.
Bipolar vulnerability and extreme appraisals of internal states: a computerized ratings study.

PubMed

Dodd, Alyson L; Mansell, Warren; Morrison, Anthony P; Tai, Sara

2011-01-01

A recent integrative cognitive model proposed that multiple, extreme, personalized, positive and negative appraisals of internal states predispose to maintain and exacerbate bipolar symptoms. This study aimed to directly assess conviction in a range of positive and negative appraisals of internal states suggested by the model, by using a laboratory-based computerized task. In a student sample (n = 68), a history of hypomania was associated with more positive and less negative appraisals of internal states, and a history of depression was associated with more negative appraisals and less positive appraisals of internal states. The sample was then split into three groups for comparison: bipolar risk (n = 18), depression risk (n = 20) and controls (n = 30). Relative to controls, the bipolar risk group made more extreme ratings of catastrophic appraisals of low activation states and tended to make more extreme ratings of appraisals of high activation states. The depression risk group scored higher on a range of negative appraisals of low activation states. These findings provide tentative support for the role of both positive and negative, extreme, personalized appraisals of internal states in hypomania and depression. Copyright © 2011 John Wiley & Sons, Ltd.
The Impact of Air-Sea Interactions on the Representation of Tropical Precipitation Extremes

NASA Astrophysics Data System (ADS)

Hirons, L. C.; Klingaman, N. P.; Woolnough, S. J.

2018-02-01

The impacts of air-sea interactions on the representation of tropical precipitation extremes are investigated using an atmosphere-ocean-mixed-layer coupled model. The coupled model is compared to two atmosphere-only simulations driven by the coupled-model sea-surface temperatures (SSTs): one with 31 day running means (31 d), the other with a repeating mean annual cycle. This allows separation of the effects of interannual SST variability from those of coupled feedbacks on shorter timescales. Crucially, all simulations have a consistent mean state with very small SST biases against present-day climatology. 31d overestimates the frequency, intensity, and persistence of extreme tropical precipitation relative to the coupled model, likely due to excessive SST-forced precipitation variability. This implies that atmosphere-only attribution and time-slice experiments may overestimate the strength and duration of precipitation extremes. In the coupled model, air-sea feedbacks damp extreme precipitation, through negative local thermodynamic feedbacks between convection, surface fluxes, and SST.
Shadowgraph Study of Gradient Driven Fluctuations

NASA Technical Reports Server (NTRS)

Cannell, David; Nikolaenko, Gennady; Giglio, Marzio; Vailati, Alberto; Croccolo, Fabrizio; Meyer, William

2002-01-01

A fluid or fluid mixture, subjected to a vertical temperature and/or concentration gradient in a gravitational field, exhibits greatly enhanced light scattering at small angles. This effect is caused by coupling between the vertical velocity fluctuations due to thermal energy and the vertically varying refractive index. Physically, small upward or downward moving regions will be displaced into fluid having a refractive index different from that of the moving region, thus giving rise to the enhanced scattering. The scattered intensity is predicted to vary with scattering wave vector q, as q(sup -4), for sufficiently large q, but the divergence is quenched by gravity at small q. In the absence of gravity, the long wavelength fluctuations responsible for the enhanced scattering are predicted to grow until limited by the sample dimensions. It is thus of interest to measure the mean-squared amplitude of such fluctuations in the microgravity environment for comparison with existing theory and ground based measurements. The relevant wave vectors are extremely small, making traditional low-angle light scattering difficult or impossible because of stray elastically scattered light generated by optical surfaces. An alternative technique is offered by the shadowgraph method, which is normally used to visualize fluid flows, but which can also serve as a quantitative tool to measure fluctuations. A somewhat novel shadowgraph apparatus and the necessary data analysis methods will be described. The apparatus uses a spatially coherent, but temporally incoherent, light source consisting of a super-luminescent diode coupled to a single-mode optical fiber in order to achieve extremely high spatial resolution, while avoiding effects caused by interference of light reflected from the various optical surfaces that are present when using laser sources. Results obtained for a critical mixture of aniline and cyclohexane subjected to a vertical temperature gradient will be presented. The sample was confined between two horizontal parallel sapphire plates with a vertical spacing of 1 mm. The temperatures of the sapphire plates were controlled by independent circulating water loops that used Peltier devices to add or remove heat from the room air as required. For a mixture with a temperature gradient, two effects are involved in generating the vertical refractive index gradient, namely thermal expansion and the Soret effect, which generates a concentration gradient in response to the applied temperature gradient. For the aniline/cyclohexane system, the denser component (aniline) migrates toward the colder surface. Consequently, when heating from above, both effects result in the sample density decreasing with altitude and are stabilizing in the sense that no convective motion occurs regardless of the magnitude of the applied temperature gradient. The Soret effect is strong near a binary liquid critical point, and thus the dominant effect is due to the induced concentration gradient. The results clearly show the divergence at low q and the predicted gravitational quenching. Results obtained for different applied temperature gradients at varying temperature differences from the critical temperature, clearly demonstrate the predicted divergence of the thermal diffusion ratio. Thus, the more closely the critical point is approached, the smaller becomes the temperature gradient required to generate the same signal. Two different methods have been used to generate pure concentration gradients. In the first, a sample cell was filled with a single fluid, ethylene glycol, and a denser miscible fluid, water, was added from below thus establishing a sharp interface to begin the experiment. As time went on the two fluids diffused into each other, and large amplitude fluctuations were clearly observed at low q. The effects of gravitational quenching were also evident. In the second method, the aniline/cyclohexane sample was used, and after applying a vertical temperature gradient for several hours, the top and bottom temperatures were set equal and the thermal gradient died on a time scale of seconds, leaving the Soret induced concentration gradient in place. Again, large-scale fluctuations were observed and died away slowly in amplitude as diffusion destroyed the initial concentration gradient.
Genetic Influences on Political Ideologies: Twin Analyses of 19 Measures of Political Ideologies from Five Democracies and Genome-Wide Findings from Three Populations

PubMed Central

Hatemi, Peter K.; Medland, Sarah E.; Klemmensen, Robert; Oskarrson, Sven; Littvay, Levente; Dawes, Chris; Verhulst, Brad; McDermott, Rose; Nørgaard, Asbjørn Sonne; Klofstad, Casey; Christensen, Kaare; Johannesson, Magnus; Magnusson, Patrik K.E.; Eaves, Lindon J.; Martin, Nicholas G.

2014-01-01

Almost forty years ago, evidence from large studies of adult twins and their relatives suggested that between 30-60% of the variance in social and political attitudes could be explained by genetic influences. However, these findings have not been widely accepted or incorporated into the dominant paradigms that explain the etiology of political ideology. This has been attributed in part to measurement and sample limitations, as well the relative absence of molecular genetic studies. Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled. The only exception is a question that explicitly uses the phrase “Left-Right”. We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one’s genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits. PMID:24569950
High-resolution X-ray diffraction with no sample preparation

PubMed Central

Turner, S. M. R.; Degryse, P.; Shortland, A. J.

2017-01-01

It is shown that energy-dispersive X-ray diffraction (EDXRD) implemented in a back-reflection geometry is extremely insensitive to sample morphology and positioning even in a high-resolution configuration. This technique allows high-quality X-ray diffraction analysis of samples that have not been prepared and is therefore completely non-destructive. The experimental technique was implemented on beamline B18 at the Diamond Light Source synchrotron in Oxfordshire, UK. The majority of the experiments in this study were performed with pre-characterized geological materials in order to elucidate the characteristics of this novel technique and to develop the analysis methods. Results are presented that demonstrate phase identification, the derivation of precise unit-cell parameters and extraction of microstructural information on unprepared rock samples and other sample types. A particular highlight was the identification of a specific polytype of a muscovite in an unprepared mica schist sample, avoiding the time-consuming and difficult preparation steps normally required to make this type of identification. The technique was also demonstrated in application to a small number of fossil and archaeological samples. Back-reflection EDXRD implemented in a high-resolution configuration shows great potential in the crystallographic analysis of cultural heritage artefacts for the purposes of scientific research such as provenancing, as well as contributing to the formulation of conservation strategies. Possibilities for moving the technique from the synchrotron into museums are discussed. The avoidance of the need to extract samples from high-value and rare objects is a highly significant advantage, applicable also in other potential research areas such as palaeontology, and the study of meteorites and planetary materials brought to Earth by sample-return missions. PMID:28660862
Genetic influences on political ideologies: twin analyses of 19 measures of political ideologies from five democracies and genome-wide findings from three populations.

PubMed

Hatemi, Peter K; Medland, Sarah E; Klemmensen, Robert; Oskarsson, Sven; Littvay, Levente; Dawes, Christopher T; Verhulst, Brad; McDermott, Rose; Nørgaard, Asbjørn Sonne; Klofstad, Casey A; Christensen, Kaare; Johannesson, Magnus; Magnusson, Patrik K E; Eaves, Lindon J; Martin, Nicholas G

2014-05-01

Almost 40 years ago, evidence from large studies of adult twins and their relatives suggested that between 30 and 60% of the variance in social and political attitudes could be explained by genetic influences. However, these findings have not been widely accepted or incorporated into the dominant paradigms that explain the etiology of political ideology. This has been attributed in part to measurement and sample limitations, as well the relative absence of molecular genetic studies. Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled. The only exception is a question that explicitly uses the phrase "Left-Right". We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one's genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.
Solanum jamesii - new traits and hybrids

USDA-ARS?s Scientific Manuscript database

One of the two wild potato relatives native to the USA is Solanum jamesii (jam). The genebank has collected and studied over 120 samples since 1958. This species has been shown to have extreme late blight resistance, and its tubers have extremely long dormancy, high antioxidants, and compounds tha...
Cardiovascular consequences of extreme prematurity: the EPICure study.

PubMed

McEniery, Carmel M; Bolton, Charlotte E; Fawke, Joseph; Hennessy, Enid; Stocks, Janet; Wilkinson, Ian B; Cockcroft, John R; Marlow, Neil

2011-07-01

The long-term consequences of extreme prematurity are becoming increasingly important, given recent improvements in neonatal intensive care. The aim of the current study was to examine the cardiovascular consequences of extreme prematurity in 11-year-olds born at or before 25 completed weeks of gestation. Age and sex-matched classmates were recruited as controls. Information concerning perinatal and maternal history was collected, and current anthropometric characteristics were measured in 219 children born extremely preterm and 153 classmates. A subset of the extremely preterm children (n = 68) and classmates (n = 90) then underwent detailed haemodynamic investigations, including measurement of supine blood pressure (BP), aortic pulse wave velocity (aPWV, a measure of aortic stiffness) and augmentation index (AIx, a measure of arterial pressure wave reflections). Seated brachial systolic and diastolic BP were not different between extremely preterm children and classmates (P = 0.3 for both), although there was a small, significant elevation in supine mean and diastolic BP in the extremely preterm children (P < 0.05 for both). Arterial pressure wave reflections were significantly elevated in the extremely preterm children (P < 0.001) and this persisted after adjusting for confounding variables. However, aortic stiffness was not different between the groups (P = 0.1). These data suggest that extreme prematurity is associated with altered arterial haemodynamics in children, not evident from the examination of brachial BP alone. Moreover, the smaller, preresistance and resistance vessels rather than large elastic arteries appear to be most affected. Children born extremely preterm may be at increased future cardiovascular risk.
Conformational sampling with stochastic proximity embedding and self-organizing superimposition: establishing reasonable parameters for their practical use.

PubMed

Tresadern, Gary; Agrafiotis, Dimitris K

2009-12-01

Stochastic proximity embedding (SPE) and self-organizing superimposition (SOS) are two recently introduced methods for conformational sampling that have shown great promise in several application domains. Our previous validation studies aimed at exploring the limits of these methods and have involved rather exhaustive conformational searches producing a large number of conformations. However, from a practical point of view, such searches have become the exception rather than the norm. The increasing popularity of virtual screening has created a need for 3D conformational search methods that produce meaningful answers in a relatively short period of time and work effectively on a large scale. In this work, we examine the performance of these algorithms and the effects of different parameter settings at varying levels of sampling. Our goal is to identify search protocols that can produce a diverse set of chemically sensible conformations and have a reasonable probability of sampling biologically active space within a small number of trials. Our results suggest that both SPE and SOS are extremely competitive in this regard and produce very satisfactory results with as few as 500 conformations per molecule. The results improve even further when the raw conformations are minimized with a molecular mechanics force field to remove minor imperfections and any residual strain. These findings provide additional evidence that these methods are suitable for many everyday modeling tasks, both high- and low-throughput.
Comparison of Internal Energy Distributions of Ions Created by Electrospray Ionization and Laser Ablation-Liquid Vortex Capture-Electrospray Ionization

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

Cahill, John F.; Kertesz, Vilmos; Ovchinnikova, Olga S.

2015-06-27

Recently a number of techniques have combined laser ablation with liquid capture for mass spectrometry spot sampling and imaging applications. The newly developed non-contact liquid-vortex capture probe has been used to efficiently collect 355 nm UV laser ablated material in a continuous flow solvent stream in which the captured material dissolves and then undergoes electrospray ionization. This sampling and ionization approach has produced what appear to be classic electrospray ionization spectra; however, the softness of this sampling/ionization process versus simple electrospray ionization has not been definitely determined. A series of benzlypyridinium salts, known as thermometer ions, were used to comparemore » internal energy distributions between electrospray ionization and the UV laser ablation liquid-vortex capture probe electrospray combination. Measured internal energy distributions were identical between the two techniques, even with differences in laser fluence (0.7-3.1 J cm-2) and when using UV-absorbing or non-UV-absorbing sample substrates. This data indicates ions formed directly by UV laser ablation, if any, are likely an extremely small constituent of the total ion signal observed. Instead, neutral molecules, clusters or particulates ejected from the surface during laser ablation, subsequently captured and dissolved in the flowing solvent stream then electrosprayed are the predominant source of ion signal observed. The electrospray ionization process used controls the softness of the technique.« less
The clustering evolution of distant red galaxies in the GOODS-MUSIC sample

NASA Astrophysics Data System (ADS)

Grazian, A.; Fontana, A.; Moscardini, L.; Salimbeni, S.; Menci, N.; Giallongo, E.; de Santis, C.; Gallozzi, S.; Nonino, M.; Cristiani, S.; Vanzella, E.

2006-07-01

Aims.We study the clustering properties of Distant Red Galaxies (DRGs) to test whether they are the progenitors of local massive galaxies. Methods.We use the GOODS-MUSIC sample, a catalog of ~3000 Ks-selected galaxies based on VLT and HST observation of the GOODS-South field with extended multi-wavelength coverage (from 0.3 to 8~μm) and accurate estimates of the photometric redshifts to select 179 DRGs with J-Ks≥ 1.3 in an area of 135 sq. arcmin.Results.We first show that the J-Ks≥ 1.3 criterion selects a rather heterogeneous sample of galaxies, going from the targeted high-redshift luminous evolved systems, to a significant fraction of lower redshift (1
Clinical diagnoses in young offspring from eastern Québec multigenerational families densely affected by schizophrenia or bipolar disorder.

PubMed

Maziade, M; Gingras, N; Rouleau, N; Poulin, S; Jomphe, V; Paradis, M-E; Mérette, C; Roy, M-A

2008-02-01

The follow-up since 1989 of a large sample of multigenerational families of eastern Québec that are densely affected by schizophrenia (SZ) or bipolar disorder (BP) has permitted to look at the rates of DSM diagnoses in the young offspring of a SZ parent (HRSZ) and of a BP parent (HRBP) who had an extremely loaded family history. The sample (average age of 17.5, SD 4.5) consisted of 54 high-risk offspring (HR) having one parent affected by a DSM-IV SZ or BP. The parents descended from 21 multigenerational families that constitute a quasi-total sample of such kindred in eastern Québec. The HRs were administered a lifetime best estimate DSM-IV diagnosis. We observed that the rates, the diversity of diagnoses, the high comorbidity, the severity and the age of onset of the clinical diagnoses tended to be similar with those already reported in the offspring of affected parents with a low familial loading. Although the sample size was small, HRSZ and HRBP also tended to show similarities in their clinical status. Overall, taking into account methodological limitations, the observation early in life of some shared characteristics among HRSZ and HRBP in terms of non-psychotic diagnosis may be congruent with the accumulating evidence that several phenotypic features are shared in adulthood by the two major psychoses.
Heavy Metal Resistant, Alkalitolerant Bacteria Isolated From Serpentinizing Springs in the Zambales Ophiolite, Philippines

NASA Astrophysics Data System (ADS)

Vallalar, B.; Meyer-Dombard, D. R.; Cardace, D.; Arcilla, C. A.

2016-12-01

Serpentinization involves hydrologic alteration of ultramafic mantle rocks containing olivine and pyroxene to produce serpentine minerals. The fluids resulting from this reaction are reduced, extremely depleted in dissolved inorganic carbon, and are highly alkaline with pH values typically exceeding 10. Major byproducts of the serpentinizing reaction include iron oxides, hydrogen, methane, and small amounts of organic molecules that provide chemosynthetic energy for subsurface microbial communities. In addition, weathering of serpentine rocks often produces fluids and sediments that have elevated concentrations of various toxic heavy metals such as chromium, nickel, cobalt, copper, and zinc. Thus, microorganisms inhabiting these unique ecological niches must be adapted to a variety of physicochemical extremes. The purpose of this study is to isolate bacteria that are capable of withstanding extremely high concentrations of multiple heavy metals from serpentine fluid-associated sediments. Fluid and sediment samples for microbial culturing were collected from Manleluag Spring National Park located on the island of Luzon, Philippines. The area is part of the Zambales ophiolite range, and hosts several serpentinizing fluid seeps. Fluid emanating from the source pool of the spring, designated Manleluag 2 (ML2), has a pH of 10.83 and temperature of 34.4 °C. Luria-Bertani agar medium was supplemented with varying concentrations of five trace elements - Cu, Cr, Co, Ni, and Zn. Environmental samples were spread on each of these media and colony forming units were subsequently chosen for isolation. In all, over 20 isolates were obtained from media with concentrations ranging from 25 mg/L - 400 mg/L of each metal. Taxonomic identity of each isolate was determined using 16S rRNA gene sequences. The isolates were then tested for tolerance to alkaline conditions by altering LB medium to pH values of 8, 9, 10, 11, and 12. The majority of strains exhibit growth at the highest pH tested, demonstrating that alkalitolerant, highly metal resistant organisms are found in this serpentinizing system. These organisms are of great interest as they may be exploited for bioremediation, enzyme production, and other biotechnological applications.

Kinematic and neuromuscular relationships between lower extremity clinical movement assessments.

PubMed

Mauntel, Timothy C; Cram, Tyler R; Frank, Barnett S; Begalle, Rebecca L; Norcross, Marc F; Blackburn, J Troy; Padua, Darin A

2018-06-01

Lower extremity injuries have immediate and long-term consequences. Lower extremity movement assessments can assist with identifying individuals at greater injury risk and guide injury prevention interventions. Movement assessments identify similar movement characteristics and evidence suggests large magnitude kinematic relationships exist between movement patterns observed across assessments; however, the magnitude of the relationships for electromyographic (EMG) measures across movement assessments remains largely unknown. This study examined relationships between lower extremity kinematic and EMG measures during jump landings and single leg squats. Lower extremity three-dimensional kinematic and EMG data were sampled from healthy adults (males = 20, females = 20) during the movement assessments. Pearson correlations examined the relationships of the kinematic and EMG measures and paired samples t-tests compared mean kinematic and EMG measures between the assessments. Overall, significant moderate correlations were observed for lower extremity kinematic (r avg = 0.41, r range = 0.10-0.61) and EMG (r avg = 0.47, r range = 0.32-0.80) measures across assessments. Kinematic and EMG measures were greater during the jump landings. Jump landings and single leg squats place different demands on the body and necessitate different kinematic and EMG patterns, such that these measures are not highly correlated between assessments. Clinicians should, therefore, use multiple assessments to identify aberrant movement and neuromuscular control patterns so that comprehensive interventions can be implemented.
Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

USDA-ARS?s Scientific Manuscript database

Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...
Extreme assay sensitivity in molecular diagnostics further unveils intratumour heterogeneity in metastatic colorectal cancer as well as artifactual low-frequency mutations in the KRAS gene.

PubMed

Mariani, Sara; Bertero, Luca; Osella-Abate, Simona; Di Bello, Cristiana; Francia di Celle, Paola; Coppola, Vittoria; Sapino, Anna; Cassoni, Paola; Marchiò, Caterina

2017-07-25

Gene mutations in the RAS family rule out metastatic colorectal carcinomas (mCRCs) from anti-EGFR therapies. We report a retrospective analysis by Sequenom Massarray and fast COLD-PCR followed by Sanger sequencing on 240 mCRCs. By Sequenom, KRAS and NRAS exons 2-3-4 were mutated in 52.9% (127/240) of tumours, while BRAF codon 600 mutations reached 5% (12/240). Fast COLD-PCR found extra mutations at KRAS exon 2 in 15/166 (9%) of samples, previously diagnosed by Sequenom as wild-type or mutated at RAS (exons 3-4) or BRAF genes. After UDG digestion results were reproduced in 2/12 analysable subclonally mutated samples leading to a frequency of true subclonal KRAS mutations of 1.2% (2.1% of the previous Sequenom wild-type subgroup). In 10 out of 12 samples, the subclonal KRAS mutations disappeared (9 out of 12) or turned to a different sequence variant (1 out of 12). mCRC can harbour coexisting multiple gene mutations. High sensitivity assays allow the detection of a small subset of patients harbouring true subclonal KRAS mutations. However, DNA changes with mutant allele frequencies <3% detected in formalin-fixed paraffin-embedded samples may be artifactual in a non-negligible fraction of cases. UDG pre-treatment of DNA is mandatory to identify true DNA changes in archival samples and avoid misinterpretation due to artifacts.
Extreme assay sensitivity in molecular diagnostics further unveils intratumour heterogeneity in metastatic colorectal cancer as well as artifactual low-frequency mutations in the KRAS gene

PubMed Central

Mariani, Sara; Bertero, Luca; Osella-Abate, Simona; Di Bello, Cristiana; Francia di Celle, Paola; Coppola, Vittoria; Sapino, Anna; Cassoni, Paola; Marchiò, Caterina

2017-01-01

Background: Gene mutations in the RAS family rule out metastatic colorectal carcinomas (mCRCs) from anti-EGFR therapies. Methods: We report a retrospective analysis by Sequenom Massarray and fast COLD-PCR followed by Sanger sequencing on 240 mCRCs. Results: By Sequenom, KRAS and NRAS exons 2-3-4 were mutated in 52.9% (127/240) of tumours, while BRAF codon 600 mutations reached 5% (12/240). Fast COLD-PCR found extra mutations at KRAS exon 2 in 15/166 (9%) of samples, previously diagnosed by Sequenom as wild-type or mutated at RAS (exons 3-4) or BRAF genes. After UDG digestion results were reproduced in 2/12 analysable subclonally mutated samples leading to a frequency of true subclonal KRAS mutations of 1.2% (2.1% of the previous Sequenom wild-type subgroup). In 10 out of 12 samples, the subclonal KRAS mutations disappeared (9 out of 12) or turned to a different sequence variant (1 out of 12). Conclusions: mCRC can harbour coexisting multiple gene mutations. High sensitivity assays allow the detection of a small subset of patients harbouring true subclonal KRAS mutations. However, DNA changes with mutant allele frequencies <3% detected in formalin-fixed paraffin-embedded samples may be artifactual in a non-negligible fraction of cases. UDG pre-treatment of DNA is mandatory to identify true DNA changes in archival samples and avoid misinterpretation due to artifacts. PMID:28618430
Facile sonochemical synthesis of amorphous NiFe-(oxy)hydroxide nanoparticles as superior electrocatalysts for oxygen evolution reaction.

PubMed

Lee, Eunjik; Park, Ah-Hyeon; Park, Hyun-Uk; Kwon, Young-Uk

2018-01-01

In this work, we present facile synthesis of amorphous Ni/Fe mixed (oxy)hydroxide (NiFe(H)) nanoparticles (NPs) and their electrocatalytic performance for oxygen evolution reaction (OER) in alkaline media. a-NiFe(H) NPs have received lots of attention as OER electrocatalysts with many desirable properties. By using a simple sonochemical route, we prepared amorphous Ni and Fe-alkoxide (NiFe(A)) NPs whose composition can be controlled in the entire composition range (Ni 100-x Fe x , 0≤x≤1). These samples are composed of extremely small NiFe(A) NPs with Ni and Fe atoms homogeneously distributed. NiFe(A) NPs are readily converted into corresponding electrocatalytically active NiFe(H) NP by a simple electrochemical treatment. Electrochemical analysis data show that the OER activity of amorphous NiFe(H) samples follows the volcano-type trend when plotted against the Fe content. Ni 70 Fe 30 (H) sample showed the lowest overpotential of 292mV at 10mAcm -2 geo and the lowest Tafel slope of 30.4mVdec -1 , outperforming IrO x /C (326mV, 41.7mVdec -1 ). Our samples are highly durable based on the chronopotentiometry data at the current density of 10mAcm -2 geo for 2h which show that Ni 70 Fe 30 sample maintains the steady-state potential, contrary to the time-varying IrO x /C. Copyright © 2017 Elsevier B.V. All rights reserved.
Immunohistochemical myofiber typing and high-resolution myofibrillar lesion detection in LR white embedded muscle

NASA Technical Reports Server (NTRS)

Thompson, J. L.; Vijayan, K.; Riley, D. A.

2000-01-01

We have developed a method of fixing, embedding, sectioning, and staining that allows high-resolution detection of myofibrillar structure and myosin immunocytochemical muscle fiber typing in serial semithin sections of LR White plastic embedded muscle at the light microscopic level. Traditional approaches, such as cryostat sections, permit fiber typing, but small myofibrillar lesions (1-3 sarcomeres) are difficult to detect because of section thickness. Semithin sections of hydrophobic resins do not stain well either histochemically or immunocytochemically. Electron microscopy can resolve lesions and discriminate fiber types based on morphology, but the sampling area is small. Our goal was to develop a rapid method for defining both fiber type and high-resolution primary myofibrillar lesion damage. Mild fixation (1-4% paraformaldehyde, 0. 05-0.1% glutaraldehyde) and embedment in a hydrophilic resin (LR White) were used. Myofibrillar structure was extremely well preserved at the light microscopic (LM) level, and lesions could be readily resolved in Toluidine blue stained 500-nm sections. Fiber type was defined by LM immunomyosin staining of serial plastic semithin sections, which demonstrated reciprocal staining patterns for "fast (Sigma M4276) and "total" (skeletal muscle) myosins (Sigma M7523). Copyright 2000 Wiley-Liss, Inc.
Monitoring of oceanographic properties of Glacier Bay, Alaska 2004

USGS Publications Warehouse

Madison, Erica N.; Etherington, Lisa L.

2005-01-01

Glacier Bay is a recently (300 years ago) deglaciated fjord estuarine system that has multiple sills, very deep basins, tidewater glaciers, and many streams. Glacier Bay experiences a large amount of runoff, high sedimentation, and large tidal variations. High freshwater discharge due to snow and ice melt and the presence of the tidewater glaciers makes the bay extremely cold. There are many small- and large-scale mixing and upwelling zones at sills, glacial faces, and streams. The complex topography and strong currents lead to highly variable salinity, temperature, sediment, primary productivity, light penetration, stratification levels, and current patterns within a small area. The oceanographic patterns within Glacier Bay drive a large portion of the spatial and temporal variability of the ecosystem. It has been widely recognized by scientists and resource managers in Glacier Bay that a program to monitor oceanographic patterns is essential for understanding the marine ecosystem and to differentiate between anthropogenic disturbance and natural variation. This year’s sampling marks the 12th continuous year of monitoring the oceanographic conditions at 23 stations along the primary axes within Glacier Bay, AK, making this a very unique and valuable data set in terms of its spatial and temporal coverage.
Static and dynamic bending has minor effects on xylem hydraulics of conifer branches (Picea abies, Pinus sylvestris).

PubMed

Mayr, Stefan; Bertel, Clara; Dämon, Birgit; Beikircher, Barbara

2014-09-01

The xylem hydraulic efficiency and safety is usually measured on mechanically unstressed samples, although trees may be exposed to combined hydraulic and mechanical stress in the field. We analysed changes in hydraulic conductivity and vulnerability to drought-induced embolism during static bending of Picea abies and Pinus sylvestris branches as well as the effect of dynamic bending on the vulnerability. We hypothesized this mechanical stress to substantially impair xylem hydraulics. Intense static bending caused an only small decrease in hydraulic conductance (-19.5 ± 2.4% in P. abies) but no shift in vulnerability thresholds. Dynamic bending caused a 0.4 and 0.8 MPa decrease of the water potential at 50 and 88% loss of conductivity in P. sylvestris, but did not affect vulnerability thresholds in P. abies. With respect to applied extreme bending radii, effects on plant hydraulics were surprisingly small and are thus probably of minor eco-physiological importance. More importantly, results indicate that available xylem hydraulic analyses (of conifers) sufficiently reflect plant hydraulics under field conditions. © 2014 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.
Asteroid Origins Satellite (AOSAT) I: An On-orbit Centrifuge Science Laboratory

NASA Astrophysics Data System (ADS)

Lightholder, Jack; Thoesen, Andrew; Adamson, Eric; Jakubowski, Jeremy; Nallapu, Ravi; Smallwood, Sarah; Raura, Laksh; Klesh, Andrew; Asphaug, Erik; Thangavelautham, Jekan

2017-04-01

Exploration of asteroids, comets and small moons (small bodies) can answer fundamental questions relating to the formation of the solar system, the availability of resources, and the nature of impact hazards. Near-earth asteroids and the small moons of Mars are potential targets of human exploration. But as illustrated by recent missions, small body surface exploration remains challenging, expensive, and fraught with risk. Despite their small size, they are among the most extreme planetary environments, with low and irregular gravity, loosely bound regolith, extreme temperature variation, and the presence of electrically charged dust. Here we describe the Asteroid Origins Satellite (AOSAT-I), an on-orbit, 3U CubeSat centrifuge using a sandwich-sized bed of crushed meteorite fragments to replicate asteroid surface conditions. Demonstration of this CubeSat will provide a low-cost pathway to physical asteroid model validation, shed light on the origin and geophysics of asteroids, and constrain the design of future landers, rovers, resource extractors, and human missions. AOSAT-I will conduct scientific experiments within its payload chamber while operating in two distinct modes: (1) as a nonrotating microgravity laboratory to investigate primary accretion, and (2) as a rotating centrifuge producing artificial milligravity to simulate surface conditions on asteroids, comets and small moons. AOSAT-I takes advantage of low-cost, off-the-shelf components, modular design, and the rapid assembly and instrumentation of the CubeSat standard, to answer fundamental questions in planetary science and reduce cost and risk of future exploration.
Measurements of characteristic parameters of extremely small cogged wheels with low module by means of low-coherence interferometry

NASA Astrophysics Data System (ADS)

Pakula, Anna; Tomczewski, Slawomir; Skalski, Andrzej; Biało, Dionizy; Salbut, Leszek

2010-05-01

This paper presents novel application of Low Coherence Interferometry (LCI) in measurements of characteristic parameters as circular pitch, foot diameter, heads diameter, in extremely small cogged wheels (cogged wheel diameter lower than θ=3 mm and module m = 0.15) produced from metal and ceramics. The most interesting issue concerning small diameter cogged wheels occurs during their production. The characteristic parameters of the wheel depend strongly on the manufacturing process and while inspecting small diameter wheels the shrinkage during the cast varies with the slight change of fabrication process. In the paper the LCI interferometric Twyman - Green setup with pigtailed high power light emitting diode, for cogged wheels measurement, is described. Due to its relatively big field of view the whole wheel can be examined in one measurement, without the necessity of numerical stitching. For purposes of small cogged wheel's characteristic parameters measurement the special binarization algorithm was developed and successfully applied. At the end the results of measurement of heads and foot diameters of two cogged wheels obtained by proposed LCI setup are presented and compared with the results obtained by the commercial optical profiler. The results of examination of injection moulds used for fabrication of measured cogged wheels are also presented. Additionally, the value of cogged wheels shrinkage is calculated as a conclusion for obtained results. Proposed method is suitable for complex measurements of small diameter cogged wheels with low module especially when there are no measurements standards for such objects.
Dynamic response analysis of a 24-story damped steel structure

NASA Astrophysics Data System (ADS)

Feng, Demin; Miyama, Takafumi

2017-10-01

In Japanese and Chinese building codes, a two-stage design philosophy, damage limitation (small earthquake, Level 1) and life safety (extreme large earthquake, Level 2), is adopted. It is very interesting to compare the design method of a damped structure based on the two building codes. In the Chinese code, in order to be consistent with the conventional seismic design method, the damped structure is also designed at the small earthquake level. The effect of damper systems is considered by the additional damping ratio concept. The design force will be obtained from the damped design spectrum considering the reduction due to the additional damping ratio. The additional damping ratio by the damper system is usually calculated by a time history analysis method at the small earthquake level. The velocity dependent type dampers such as viscous dampers can function well even in the small earthquake level. But, if steel damper is used, which usually remains elastic in the small earthquake, there will be no additional damping ratio achieved. On the other hand, a time history analysis is used in Japan both for small earthquake and extreme large earthquake level. The characteristics of damper system and ductility of the structure can be modelled well. An existing 24-story steel frame is modified to demonstrate the design process of the damped structure based on the two building codes. Viscous wall type damper and low yield steel panel dampers are studied as the damper system.
Discrimination of different genuine Danshen and their extracts by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

NASA Astrophysics Data System (ADS)

Liu, Xin-hu; Xu, Chang-hua; Sun, Su-qin; Huang, Jian; Zhang, Ke; Li, Guo-yu; Zhu, Yun; Zhou, Qun; Zhang, Zhi-cheng; Wang, Jin-hui

2012-11-01

In this study, six varieties of Danshen from different populations and genuine ("Daodi" in Chinese transliteration) regions were discriminated and identified by a three-step infrared spectroscopy method (Fourier transform-infrared spectroscopy (FT-IR) coupled with second derivative infrared spectroscopy (SD-IR) and two dimensional correlation infrared spectroscopy (2D-IR)). Though only small differences were found among the FT-IR spectra of the six Danshen samples, the positions and intensities of peaks at 3393, 3371, 1613, 1050, and 1036 cm-1 could be considered as the key factors to discriminate them. More significant differences were exhibited in their SD-IR, particularly for the peaks around 1080, 1144, 695, 665, 800, 1610, 1510, 1450, 1117 and 1077 cm-1. The visual 2D-IR spectra provided dynamic chemical structure information of the six Danshen samples with presenting different particular auto-peak clusters, respectively. Moreover, the contents of salvianolic acid B in all samples were measured quantitatively by a validated ultra performance liquid chromatography (UPLC), which was consistent with the FT-IR findings. This study provides a promising method for characteristics and quality control of the complicated and extremely similar herbal medicine like Danshen, which is more cost effective and time saving.
Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

DOE PAGES

Bang, W.; Albright, B. J.; Bradley, P. A.; ...

2015-09-22

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore » unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less
Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams.

PubMed

Bang, W; Albright, B J; Bradley, P A; Gautier, D C; Palaniyappan, S; Vold, E L; Santiago Cordoba, M A; Hamilton, C E; Fernández, J C

2015-09-22

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has been unavailable to date. Here we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.
A personal sampler for aircraft engine cold start particles: laboratory development and testing.

PubMed

Armendariz, Alfredo; Leith, David

2003-01-01

Industrial hygienists in the U.S. Air Force are concerned about exposure of their personnel to jet fuel. One potential source of exposure for flightline ground crews is the plume emitted during the start of aircraft engines in extremely cold weather. The purpose of this study was to investigate a personal sampler, a small tube-and-wire electrostatic precipitator (ESP), for assessing exposure to aircraft engine cold start particles. Tests were performed in the laboratory to characterize the sampler's collection efficiency and to determine the magnitude of adsorption and evaporation artifacts. A low-temperature chamber was developed for the artifact experiments so tests could be performed at temperatures similar to actual field conditions. The ESP collected particles from 0.5 to 20 micro m diameter with greater than 98% efficiency at particle concentrations up to 100 mg/m(3). Adsorption artifacts were less than 5 micro g/m(3) when sampling a high concentration vapor stream. Evaporation artifacts were significantly lower for the ESP than for PVC membrane filters across a range of sampling times and incoming vapor concentrations. These tests indicate that the ESP provides more accurate exposure assessment results than traditional filter-based particle samplers when sampling cold start particles produced by an aircraft engine.
Combinatorial Multidomain Mesoporous Chips and a Method for Fractionation, Stabilization, and Storage of Biomolecules

NASA Technical Reports Server (NTRS)

Tasciotti, Ennio (Inventor); Hu, Ye (Inventor); Ferrari, Mauro (Inventor); Bouamrani, Ali (Inventor); Liu, Xuewu (Inventor)

2014-01-01

A new fractionation device shows desirable features for exploratory screening and biomarker discovery. The constituent MSCs may be tailored for desired pore sizes and surface properties and for the sequestration and enrichment of extremely low abundant protein and peptides in desired ranges of the mass/charge spectrum. The MSCs are effective in yielding reproducible extracts from complex biological samples as small as 10 microliter in a time as short as 30 minutes. They are inexpensive to manufacture, and allow for scaled up production to attain the simultaneous processing of a large number of samples. The MSCs are multiplexed, label-free diagnostic tools with the potential of biological recognition moiety modification for enhanced specificity. The MSCs may store, protect and stabilize biological fluids, enabling the simplified and cost-effective collection and transportation of clinical samples. The MSC-based device may serve as a diagnostic tool to complement histopathology, imaging, and other conventional clinical techniques. The MSCs mediated identification of disease-specific protein signatures may help in the selection of personalized therapeutic combinations, in the real-time assessment of therapeutic efficacy and toxicity, and in the rational modulation of therapy based on the changes in the protein networks associated with the prognosis and the drug resistance of the disease.
Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

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

Bang, W.; Albright, B. J.; Bradley, P. A.

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has beenmore » unavailable to date. We have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.« less
Visualization of expanding warm dense gold and diamond heated rapidly by laser-generated ion beams

NASA Astrophysics Data System (ADS)

Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Cordoba, M. A. Santiago; Hamilton, C. E.; Fernández, J. C.

2015-09-01

With the development of several novel heating sources, scientists can now heat a small sample isochorically above 10,000 K. Although matter at such an extreme state, known as warm dense matter, is commonly found in astrophysics (e.g., in planetary cores) as well as in high energy density physics experiments, its properties are not well understood and are difficult to predict theoretically. This is because the approximations made to describe condensed matter or high-temperature plasmas are invalid in this intermediate regime. A sufficiently large warm dense matter sample that is uniformly heated would be ideal for these studies, but has been unavailable to date. Here we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils uniformly and isochorically. For the first time, we visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperature of these heated samples from the measured expansion speeds of gold and diamond into vacuum. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics.
Development of a Micro-Fabricated Total-Field Magnetometer

DTIC Science & Technology

2011-03-01

are made with fluxgate technologies. Fluxgates have lower sensitivity than Cs magnetometers , yet they continue to be used in small wands simply...extraction process by providing the sensitivity of a Cs magnetometer with the convenience and low cost of a fluxgate wand. Extremely small and low cost...FINAL REPORT Development of a Micro-Fabricated Total-Field Magnetometer SERDP Project MR-1512 MARCH 2011 Mark Prouty Geometrics, Inc
Finding the Right Fit: Assessing the Impact of Traditional v. Large Lecture/Small Lab Course Formats on a General Education Course

ERIC Educational Resources Information Center

Wildermuth, Susan M.; French, Tammy; Fredrick, Edward

2013-01-01

This study explores alternative approaches for teaching general education courses burdened with serving extremely large enrollments. It compares the effectiveness of a self-contained course in which each course section is taught by one instructor to a large lecture/small lab format in which all course enrollees attend one large lecture section and…

Heat and hydration status: Predictors of repeated measures of urine specific gravity among Tsimane' adults in the Bolivian Amazon.

PubMed

Rosinger, Asher

2015-12-01

Hydration status is critical to physiological and cognitive health, yet it is unclear how populations living in hot-humid environments experiencing lifestyle transitions manage this underexplored facet of heat adaptation. This study assesses the predictors of repeated measures of hydration status for adults from two villages (close and distant from a market town) in the Bolivian Amazon. Interviews and focal follows were conducted with 36 Tsimane' (50% male). Urine samples, temperature, activity levels, and anthropometrics were measured pre-interview and post-follow and yielded a small panel (72 observations). Urine samples were analyzed for urine specific gravity (USG), a biomarker of hydration, with a refractometer. The mean USG was 1.020 g/ml (SD ± 0.008) with men (1.022 ± 0.008) slightly more dehydrated than women (1.018 ± 0.007). Using 1.020 as the criteria for clinical dehydration, 42% of the participants were dehydrated at both intervals and 21% were extremely dehydrated. Controlling for activity level, village membership, and covariates in random-effects linear regression models, each degree centigrade increase was associated with a USG increase of 0.0008 g/ml (P = 0.000). Adults from the village closer to the market town had significantly higher USG (B = 0.0041; P = 0.04) than those in the distant village. Dehydration was predicted to occur at 29°C, just above the thermoneutral range, and extreme dehydration at 37°C. These findings suggest that hotter temperatures coupled with lifestyle transitions may create conditions that increase vulnerability to dehydration among rural populations through landscape modifications and diet changes. © 2015 Wiley Periodicals, Inc.
Microfluidic acoustophoretic force based low-concentration oil separation and detection from the environment.

PubMed

Wang, Han; Liu, Zhongzheng; Kim, Sungman; Koo, Chiwan; Cho, Younghak; Jang, Dong-Young; Kim, Yong-Joe; Han, Arum

2014-03-07

Detecting and quantifying extremely low concentrations of oil from the environment have broad applications in oil spill monitoring in ocean and coastal areas as well as in oil leakage monitoring on land. Currently available methods for low-concentration oil detection are bulky or costly with limited sensitivities. Thus they are difficult to be used as portable and field-deployable detectors in the case of oil spills or for monitoring the long-term effects of dispersed oil on marine and coastal ecosystems. Here, we present a low-concentration oil droplet trapping and detection microfluidic system based on the acoustophoresis phenomenon where oil droplets in water having a negative acoustic contrast factor move towards acoustic pressure anti-nodes. By trapping oil droplets from water samples flowing through a microfluidic channel, even very low concentrations of oil droplets can be concentrated to a detectable level for further analyses, which is a significant improvement over currently available oil detection systems. Oil droplets in water were successfully trapped and accumulated in a circular acoustophoretic trapping chamber of the microfluidic device and detected using a custom-built compact fluorescent detector based on the natural fluorescence of the trapped crude oil droplets. After the on-line detection, crude oil droplets released from the trapping chamber were successfully separated into a collection outlet by acoustophoretic force for further off-chip analyses. The developed microfluidic system provides a new way of trapping, detecting, and separating low-concentration crude oil from environmental water samples and holds promise as a low-cost field-deployable oil detector with extremely high sensitivity. The microfluidic system and operation principle are expected to be utilized in a wide range of applications where separating, concentrating, and detecting small particles having a negative acoustic contrast factor are required.
Oxygen isotope compositions of selected laramide-tertiary granitoid stocks in the Colorado Mineral Belt and their bearing on the origin of climax-type granite-molybdenum systems

USGS Publications Warehouse

Hannah, J.L.; Stein, H.J.

1986-01-01

Quartz phenocrysts from 31 granitoid stocks in the Colorado Mineral Belt yield ??18O values less than 10.4???, with most values between 9.3 and 10.4???. An average magmatic value of about 8.5??? is suggested. The stocks resemble A-type granites; these data support magma genesis by partial melting of previously depleted, fluorine-enriched, lower crustal granulites, followed by extreme differentiation and volatile evolution in the upper crust. Subsolidus interaction of isotopically light water with stocks has reduced most feldspar and whole rock ??18O values. Unaltered samples from Climax-type molybdenumbearing granites, however, show no greater isotopic disturbance than samples from unmineralized stocks. Although meteoric water certainly played a role in post-mineralization alteration, particularly in feldspars, it is not required during high-temperature mineralization processes. We suggest that slightly low ??18O values in some vein and replacement minerals associated with molybdenum mineralization may have resulted from equilibration with isotopically light magmatic water and/or heavy isotope depletion of the ore fluid by precipitation of earlier phases. Accumulation of sufficient quantities of isotopically light magmatic water to produce measured depletions of 18O requires extreme chemical stratification in a large magma reservoir. Upward migration of a highly fractionated, volatile-rich magma into a small apical Climax-type diapir, including large scale transport of silica, alkalis, molybdenum, and other vapor soluble elements, may occur with depression of the solidus temperature and reduction of magma viscosity by fluorine. Climax-type granites may provide examples of 18O depletion in magmatic systems without meteoric water influx. ?? 1986 Springer-Verlag.
Disturbance legacies and climate jointly drive tree growth and mortality in an intensively studied boreal forest

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

Bond-Lamberty, Benjamin; Rocha, Adrian; Calvin, Katherine V.

2014-01-01

How will regional growth and mortality change with even relatively small climate shifts, even independent of catastrophic disturbances? This question is particularly acute for the North American boreal forest, which is carbon-dense and subject The goals of this study were to combine dendrochronological sampling, inventory records, and machine-learning algorithms to understand how tree growth and death have changed at one highly studied site (Northern Old Black Spruce, NOBS) in the central Canadian boreal forest. Over the 1999-2012 inventory period, mean DBH increased even as stand density and basal area declined significantly from 41.3 to 37.5 m2 ha-1. Tree mortality averagedmore » 1.4±0.6% yr-1, with most mortality occurring in medium-sized trees. A combined tree ring chronology constructed from 2001, 2004, and 2012 sampling showed several periods of extreme growth depression, with increased mortality lagging depressed growth by ~5 years. Minimum and maximum air temperatures exerted a negative influence on tree growth, while precipitation and climate moisture index had a positive effect; both current- and previous-year data exerted significant effects. Models based on these variables explained 23-44% of the ring-width variability. There have been at least one, and probably two, significant recruitment episodes since stand initiation, and we infer that past climate extremes led to significant NOBS mortality still visible in the current forest structure. These results imply that a combination of successional and demographic processes, along with mortality driven by abiotic factors, continue to affect the stand, with significant implications for our understanding of previous work at NOBS and the sustainable management of regional forests.« less
The Mass-loss Return from Evolved Stars to the Large Magellanic Cloud. IV. Construction and Validation of a Grid of Models for Oxygen-rich AGB Stars, Red Supergiants, and Extreme AGB Stars

NASA Astrophysics Data System (ADS)

Sargent, Benjamin A.; Srinivasan, S.; Meixner, M.

2011-02-01

To measure the mass loss from dusty oxygen-rich (O-rich) evolved stars in the Large Magellanic Cloud (LMC), we have constructed a grid of models of spherically symmetric dust shells around stars with constant mass-loss rates using 2Dust. These models will constitute the O-rich model part of the "Grid of Red supergiant and Asymptotic giant branch star ModelS" (GRAMS). This model grid explores four parameters—stellar effective temperature from 2100 K to 4700 K luminosity from 103 to 106 L sun; dust shell inner radii of 3, 7, 11, and 15 R star; and 10.0 μm optical depth from 10-4 to 26. From an initial grid of ~1200 2Dust models, we create a larger grid of ~69,000 models by scaling to cover the luminosity range required by the data. These models are available online to the public. The matching in color-magnitude diagrams and color-color diagrams to observed O-rich asymptotic giant branch (AGB) and red supergiant (RSG) candidate stars from the SAGE and SAGE-Spec LMC samples and a small sample of OH/IR stars is generally very good. The extreme AGB star candidates from SAGE are more consistent with carbon-rich (C-rich) than O-rich dust composition. Our model grid suggests lower limits to the mid-infrared colors of the dustiest AGB stars for which the chemistry could be O-rich. Finally, the fitting of GRAMS models to spectral energy distributions of sources fit by other studies provides additional verification of our grid and anticipates future, more expansive efforts.
Outliers and Extremes: Dragon-Kings or Dragon-Fools?

NASA Astrophysics Data System (ADS)

Schertzer, D. J.; Tchiguirinskaia, I.; Lovejoy, S.

2012-12-01

Geophysics seems full of monsters like Victor Hugo's Court of Miracles and monstrous extremes have been statistically considered as outliers with respect to more normal events. However, a characteristic magnitude separating abnormal events from normal ones would be at odd with the generic scaling behaviour of nonlinear systems, contrary to "fat tailed" probability distributions and self-organized criticality. More precisely, it can be shown [1] how the apparent monsters could be mere manifestations of a singular measure mishandled as a regular measure. Monstrous fluctuations are the rule, not outliers and they are more frequent than usually thought up to the point that (theoretical) statistical moments can easily be infinite. The empirical estimates of the latter are erratic and diverge with sample size. The corresponding physics is that intense small scale events cannot be smoothed out by upscaling. However, based on a few examples, it has also been argued [2] that one should consider "genuine" outliers of fat tailed distributions so monstrous that they can be called "dragon-kings". We critically analyse these arguments, e.g. finite sample size and statistical estimates of the largest events, multifractal phase transition vs. more classical phase transition. We emphasize the fact that dragon-kings are not needed in order that the largest events become predictable. This is rather reminiscent of the Feast of Fools picturesquely described by Victor Hugo. [1] D. Schertzer, I. Tchiguirinskaia, S. Lovejoy et P. Hubert (2010): No monsters, no miracles: in nonlinear sciences hydrology is not an outlier! Hydrological Sciences Journal, 55 (6) 965 - 979. [2] D. Sornette (2009): Dragon-Kings, Black Swans and the Prediction of Crises. International Journal of Terraspace Science and Engineering 1(3), 1-17.
Temperature-Related Death and Illness. Chapter 2

NASA Technical Reports Server (NTRS)

Sarofim, Marcus C.; Saha, Shubhayu; Hawkins, Michelle D.; Mills, David M.; Hess, Jeremy; Horton, Radley; Kinney, Patrick; Schwartz, Joel; St. Juliana, Alexis

2016-01-01

Based on present-day sensitivity to heat, an increase of thousands to tens of thousands of premature heat-related deaths in the summer and a decrease of premature cold-related deaths in the winter are projected each year as a result of climate change by the end of the century. Future adaptation will very likely reduce these impacts (see Changing Tolerance to Extreme Heat Finding). The reduction in cold-related deaths is projected to be smaller than the increase in heat-related deaths in most regions. Days that are hotter than usual in the summer or colder than usual in the winter are both associated with increased illness and death. Mortality effects are observed even for small differences from seasonal average temperatures. Because small temperature differences occur much more frequently than large temperature differences, not accounting for the effect of these small differences would lead to underestimating the future impact of climate change. An increase in population tolerance to extreme heat has been observed over time. Changes in this tolerance have been associated with increased use of air conditioning, improved social responses, and or physiological acclimatization, among other factors. Expected future increases in this tolerance will reduce the projected increase in deaths from heat. Older adults and children have a higher risk of dying or becoming ill due to extreme heat. People working outdoors, the socially isolated and economically disadvantaged, those with chronic illnesses, as well as some communities of color, are also especially vulnerable to death or illness.
AN AUTOMATIC DETECTION METHOD FOR EXTREME-ULTRAVIOLET DIMMINGS ASSOCIATED WITH SMALL-SCALE ERUPTION

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

Alipour, N.; Safari, H.; Innes, D. E.

2012-02-10

Small-scale extreme-ultraviolet (EUV) dimming often surrounds sites of energy release in the quiet Sun. This paper describes a method for the automatic detection of these small-scale EUV dimmings using a feature-based classifier. The method is demonstrated using sequences of 171 Angstrom-Sign images taken by the STEREO/Extreme UltraViolet Imager (EUVI) on 2007 June 13 and by Solar Dynamics Observatory/Atmospheric Imaging Assembly on 2010 August 27. The feature identification relies on recognizing structure in sequences of space-time 171 Angstrom-Sign images using the Zernike moments of the images. The Zernike moments space-time slices with events and non-events are distinctive enough to be separatedmore » using a support vector machine (SVM) classifier. The SVM is trained using 150 events and 700 non-event space-time slices. We find a total of 1217 events in the EUVI images and 2064 events in the AIA images on the days studied. Most of the events are found between latitudes -35 Degree-Sign and +35 Degree-Sign . The sizes and expansion speeds of central dimming regions are extracted using a region grow algorithm. The histograms of the sizes in both EUVI and AIA follow a steep power law with slope of about -5. The AIA slope extends to smaller sizes before turning over. The mean velocity of 1325 dimming regions seen by AIA is found to be about 14 km s{sup -1}.« less
Heavy metal pollution caused by small-scale metal ore mining activities: A case study from a polymetallic mine in South China.

PubMed

Sun, Zehang; Xie, Xiande; Wang, Ping; Hu, Yuanan; Cheng, Hefa

2018-10-15

Although metal ore mining activities are well known as an important source of heavy metals, soil pollution caused by small-scale mining activities has long been overlooked. This study investigated the pollution of surface soils in an area surrounding a recently abandoned small-scale polymetallic mining district in Guangdong province of south China. A total of 13 tailing samples, 145 surface soil samples, and 29 water samples were collected, and the concentrations of major heavy metals, including Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb, and Se, were determined. The results show that the tailings contained high levels of heavy metals, with Cu, Zn, As, Cd, and Pb occurring in the ranges of 739-4.15 × 10 3 , 1.81 × 10 3 -5.00 × 10 3 , 118-1.26 × 10 3 , 8.14-57.7, and 1.23 × 10 3 -6.99 × 10 3  mg/kg, respectively. Heavy metals also occurred at high concentrations in the mine drainages (15.4-17.9 mg/L for Cu, 21.1-29.3 mg/L for Zn, 0.553-0.770 mg/L for Cd, and 1.17-2.57 mg/L for Pb), particularly those with pH below 3. The mean contents of Cu, Zn, As, Cd, and Pb in the surface soils of local farmlands were up to 7 times higher than the corresponding background values, and results of multivariate statistical analysis clearly indicate that Cu, Zn, Cd, and Pb were largely contributed by the mining activities. The surface soils from farmlands surrounding the mining district were moderately to seriously polluted, while the potential ecological risk of heavy metal pollution was extremely high. It was estimated that the input fluxes from the mining district to the surrounding farmlands were approximately 17.1, 59.2, 0.311, and 93.8 kg/ha/yr for Cu, Zn, Cd, and Pb, respectively, which probably occurred through transport of fine tailings by wind and runoff, and mine drainage as well. These findings indicate the significant need for proper containment of the mine tailings at small-scale metal ore mines. Copyright © 2018. Published by Elsevier B.V.
Estimating the probability that the sample mean is within a desired fraction of the standard deviation of the true mean.

PubMed

Schillaci, Michael A; Schillaci, Mario E

2009-02-01

The use of small sample sizes in human and primate evolutionary research is commonplace. Estimating how well small samples represent the underlying population, however, is not commonplace. Because the accuracy of determinations of taxonomy, phylogeny, and evolutionary process are dependant upon how well the study sample represents the population of interest, characterizing the uncertainty, or potential error, associated with analyses of small sample sizes is essential. We present a method for estimating the probability that the sample mean is within a desired fraction of the standard deviation of the true mean using small (n<10) or very small (n < or = 5) sample sizes. This method can be used by researchers to determine post hoc the probability that their sample is a meaningful approximation of the population parameter. We tested the method using a large craniometric data set commonly used by researchers in the field. Given our results, we suggest that sample estimates of the population mean can be reasonable and meaningful even when based on small, and perhaps even very small, sample sizes.
A New Sample of Cool Subdwarfs from SDSS: Properties and Kinematics

NASA Astrophysics Data System (ADS)

Savcheva, Antonia S.; West, Andrew A.; Bochanski, John J.

2014-10-01

We present a new sample of M subdwarfs compiled from the seventh data release of the Sloan Digital Sky Survey. With 3517 new subdwarfs, this new sample significantly increases the number of spectroscopically confirmed low-mass subdwarfs. This catalog also includes 905 extreme and 534 ultra sudwarfs. We present the entire catalog, including observed and derived quantities, and template spectra created from co-added subdwarf spectra. We show color-color and reduced proper motion diagrams of the three metallicity classes, which are shown to separate from the disk dwarf population. The extreme and ultra subdwarfs are seen at larger values of reduced proper motion, as expected for more dynamically heated populations. We determine 3D kinematics for all of the stars with proper motions. The color-magnitude diagrams show a clear separation of the three metallicity classes with the ultra and extreme subdwarfs being significantly closer to the main sequence than the ordinary subdwarfs. All subdwarfs lie below (fainter) and to the left (bluer) of the main sequence. Based on the average (U, V, W) velocities and their dispersions, the extreme and ultra subdwarfs likely belong to the Galactic halo, while the ordinary subdwarfs are likely part of the old Galactic (or thick) disk. An extensive activity analysis of subdwarfs is performed using Hα emission, and 208 active subdwarfs are found. We show that while the activity fraction of subdwarfs rises with spectral class and levels off at the latest spectral classes, consistent with the behavior of M dwarfs, the extreme and ultra subdwarfs are basically flat.
Intensification of hot extremes in the United States

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

Diffenbaugh, Noah; Ashfaq, Moetasim

Governments are currently considering policies that will limit greenhouse gas concentrations, including negotiation of an international treaty to replace the expiring Kyoto Protocol. Existing mitigation targets have arisen primarily from political negotiations, and the ability of such policies to avoid dangerous impacts is still uncertain. Using a large suite of climate model experiments, we find that substantial intensification of hot extremes could occur within the next 3 decades, below the 2 C global warming target currently being considered by policy makers. We also find that the intensification of hot extremes is associated with a shift towards more anticyclonic atmospheric circulationmore » during the warm season, along with warm-season drying over much of the U.S. The possibility that intensification of hot extremes could result from relatively small increases in greenhouse gas concentrations suggests that constraining global warming to 2 C may not be sufficient to avoid dangerous climate change.« less
A simple scaling approach to produce climate scenarios of local precipitation extremes for the Netherlands

NASA Astrophysics Data System (ADS)

Lenderink, Geert; Attema, Jisk

2015-08-01

Scenarios of future changes in small scale precipitation extremes for the Netherlands are presented. These scenarios are based on a new approach whereby changes in precipitation extremes are set proportional to the change in water vapor amount near the surface as measured by the 2m dew point temperature. This simple scaling framework allows the integration of information derived from: (i) observations, (ii) a new unprecedentedly large 16 member ensemble of simulations with the regional climate model RACMO2 driven by EC-Earth, and (iii) short term integrations with a non-hydrostatic model Harmonie. Scaling constants are based on subjective weighting (expert judgement) of the three different information sources taking also into account previously published work. In all scenarios local precipitation extremes increase with warming, yet with broad uncertainty ranges expressing incomplete knowledge of how convective clouds and the atmospheric mesoscale circulation will react to climate change.
Relative optical navigation around small bodies via Extreme Learning Machine

NASA Astrophysics Data System (ADS)

Law, Andrew M.

To perform close proximity operations under a low-gravity environment, relative and absolute positions are vital information to the maneuver. Hence navigation is inseparably integrated in space travel. Extreme Learning Machine (ELM) is presented as an optical navigation method around small celestial bodies. Optical Navigation uses visual observation instruments such as a camera to acquire useful data and determine spacecraft position. The required input data for operation is merely a single image strip and a nadir image. ELM is a machine learning Single Layer feed-Forward Network (SLFN), a type of neural network (NN). The algorithm is developed on the predicate that input weights and biases can be randomly assigned and does not require back-propagation. The learned model is the output layer weights which are used to calculate a prediction. Together, Extreme Learning Machine Optical Navigation (ELM OpNav) utilizes optical images and ELM algorithm to train the machine to navigate around a target body. In this thesis the asteroid, Vesta, is the designated celestial body. The trained ELMs estimate the position of the spacecraft during operation with a single data set. The results show the approach is promising and potentially suitable for on-board navigation.
Astronomical variation experiments with a Mars general circulation model

NASA Technical Reports Server (NTRS)

Pollack, J. B.; Haberle, R. M.; Murphy, J. R.; Schaeffer, J.; Lee, H.

1992-01-01

In time scales of a hundred thousand to a million years, the eccentricity of Mars orbit varies in a quasi-periodic manner between extremes as large as 0.14 and as small as 0 and the tilt of its axis of rotation with respect to the orbit normal also varies quasi-periodically between extremes as large as 35 deg and as small as 15 deg. In addition, the orientation of the axis precesses on comparable time scales. These astronomical variations are much more extreme than those experienced by the Earth. These variations are thought to have strongly modulated the seasonal cycles of dust, carbon dioxide, and water. One manifestation of the induced quasiperiodic climate changes may be the layered terrain of the polar regions, with individual layers perhaps recording variations in the absolute and/or relative deposition rates of dust and water in the polar regions, most likely in association with the winter time deposition of carbon dioxide ice. In an attempt to understand the manner in which atmospheric temperatures and winds respond to the astronomical forcings, we have initiated a series of numerical experiments with the NASA/Ames general circulation model of the Martian Atmosphere.
Optimal sensitivity for molecular recognition MAC-mode AFM

PubMed

Schindler; Badt; Hinterdorfer; Kienberger; Raab; Wielert-Badt; Pastushenko

2000-02-01

Molecular recognition force microscopy (MRFM) using the magnetic AC mode (MAC mode) atomic force microscope (AFM) was recently investigated to locate and probe recognition sites. A flexible crosslinker carrying a ligand is bound to the tip for the molecular recognition of receptors on the surface of a sample. In this report, the driving frequency is calculated which optimizes the sensitivity (S). The sensitivity of MRFM is defined as the relative change of the magnetically excited cantilever deflection amplitude arising from a crosslinker/antibody/antigen connection that is characterized by a very small force constant. The sensitivity is calculated in a damped oscillator model with a certain value of quality factor Q, which, together with load, defines the frequency response (unloaded oscillator shows resonance at Q > 0.707). If Q < 1, the greatest value of S corresponds to zero driving frequency omega (measured in units of eigenfrequency). Therefore, for Q < 1, MAC-mode has no advantage in comparison with DC-mode. Two additional extremes are found at omegaL = (1 - 1/Q)(1/2) and omegaR = (1 + 1/Q)(1/2), with corresponding sensitivities S(L) = Q2/(2Q - 1), S(R) = Q2/(2Q + 1). The L-extreme exists only for Q > 1, and then S(L) > S(R), i.e. the L-extreme is the main one. For Q > 1, S(L) > 1, and for Q > 2.41, S(R) > 1. These are the critical Q-values, above which selecting driving frequency equal to sigmaL or sigmaR brings advantage to MAC mode vs. DC mode. Satisfactory quality of the oscillator model is demonstrated by comparison of some results with those calculated within the classical description of cantilevers.
Extremely red quasars in BOSS

NASA Astrophysics Data System (ADS)

Hamann, Fred; Zakamska, Nadia L.; Ross, Nicholas; Paris, Isabelle; Alexandroff, Rachael M.; Villforth, Carolin; Richards, Gordon T.; Herbst, Hanna; Brandt, W. Niel; Cook, Ben; Denney, Kelly D.; Greene, Jenny E.; Schneider, Donald P.; Strauss, Michael A.

2017-01-01

Red quasars are candidate young objects in an early transition stage of massive galaxy evolution. Our team recently discovered a population of extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey (BOSS) that has a suite of peculiar emission-line properties including large rest equivalent widths (REWs), unusual `wingless' line profiles, large N V/Lyα, N V/C IV, Si IV/C IV and other flux ratios, and very broad and blueshifted [O III] λ5007. Here we present a new catalogue of C IV and N V emission-line data for 216 188 BOSS quasars to characterize the ERQ line properties further. We show that they depend sharply on UV-to-mid-IR colour, secondarily on REW(C IV), and not at all on luminosity or the Baldwin Effect. We identify a `core' sample of 97 ERQs with nearly uniform peculiar properties selected via I-W3 ≥ 4.6 (AB) and REW(C IV) ≥ 100 Å at redshifts 2.0-3.4. A broader search finds 235 more red quasars with similar unusual characteristics. The core ERQs have median luminosity ˜ 47.1, sky density 0.010 deg-2, surprisingly flat/blue UV spectra given their red UV-to-mid-IR colours, and common outflow signatures including BALs or BAL-like features and large C IV emission-line blueshifts. Their SEDs and line properties are inconsistent with normal quasars behind a dust reddening screen. We argue that the core ERQs are a unique obscured quasar population with extreme physical conditions related to powerful outflows across the line-forming regions. Patchy obscuration by small dusty clouds could produce the observed UV extinctions without substantial UV reddening.
Development of a Historical Hydrological online research and application platform for Switzerland - Historical Hydrological Atlas of Switzerland (HHAS)

NASA Astrophysics Data System (ADS)

Wetter, Oliver

2017-04-01

It is planned to develop and maintain a historical hydrological online platform for Switzerland, which shall be specially designed for the needs of research and federal, cantonal or private institutions being interested in hydrological risk assessment and protection measures. The aim is on the one hand to facilitate the access to raw data which generally is needed for further historical hydrological reconstruction and quantification, so that future research will be achieved in significantly shorter time. On the other hand, new historical hydrological research results shall be continuously included in order to establish this platform as a useful tool for the assessment of hydrological risk by including the long term experience of reconstructed pre-instrumental hydrological extreme events like floods and droughts. Meteorological parameters that may trigger extreme hydrological events, like monthly or seasonally resolved reconstructions of temperature and precipitation shall be made accessible in this platform as well. The ultimate goal will be to homogenise the reconstructed hydrological extreme events which usually appeared in the pre anthropogenic influence period under different climatological as well as different hydrological regimes and topographical conditions with the present day state. Long term changes of reconstructed small- to extreme flood seasonality, based on municipal accounting records, will be included in the platform as well. This helps - in combination with the before mentioned meteorological parameters - to provide an increased understanding of the major changes in the generally complex overall system that finally causes hydrological extreme events. The goal of my presentation at the Historical Climatology session is to give an overview about the applied historical climatological and historical hydrological methodologies that are applied on the historical raw data (evidence) to reconstruct pre instrumental hydrological events and meteorological and climatological parameter. I thus will present examples of index- as well as proxy based temperature and precipitation reconstructions, index- and water level based hydrological extreme event reconstructions (floods and droughts) as well examples about accounting records based reconstructions of long term changes of small- to extreme flood events.
Accuracy and sampling error of two age estimation techniques using rib histomorphometry on a modern sample.

PubMed

García-Donas, Julieta G; Dyke, Jeffrey; Paine, Robert R; Nathena, Despoina; Kranioti, Elena F

2016-02-01

Most age estimation methods are proven problematic when applied in highly fragmented skeletal remains. Rib histomorphometry is advantageous in such cases; yet it is vital to test and revise existing techniques particularly when used in legal settings (Crowder and Rosella, 2007). This study tested Stout & Paine (1992) and Stout et al. (1994) histological age estimation methods on a Modern Greek sample using different sampling sites. Six left 4th ribs of known age and sex were selected from a modern skeletal collection. Each rib was cut into three equal segments. Two thin sections were acquired from each segment. A total of 36 thin sections were prepared and analysed. Four variables (cortical area, intact and fragmented osteon density and osteon population density) were calculated for each section and age was estimated according to Stout & Paine (1992) and Stout et al. (1994). The results showed that both methods produced a systemic underestimation of the individuals (to a maximum of 43 years) although a general improvement in accuracy levels was observed when applying the Stout et al. (1994) formula. There is an increase of error rates with increasing age with the oldest individual showing extreme differences between real age and estimated age. Comparison of the different sampling sites showed small differences between the estimated ages suggesting that any fragment of the rib could be used without introducing significant error. Yet, a larger sample should be used to confirm these results. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Trunk restraint to promote upper extremity recovery in stroke patients: a systematic review and meta-analysis.

PubMed

Wee, Seng Kwee; Hughes, Ann-Marie; Warner, Martin; Burridge, Jane H

2014-09-01

Many stroke patients exhibit excessive compensatory trunk movements during reaching. Compensatory movement behaviors may improve upper extremity function in the short-term but be detrimental to long-term recovery. To evaluate the evidence that trunk restraint limits compensatory trunk movement and/or promotes better upper extremity recovery in stroke patients. A search was conducted through electronic databases from January 1980 to June 2013. Only randomized controlled trials (RCTs) comparing upper extremity training with and without trunk restraint were selected for review. Three review authors independently assessed the methodological quality and extracted data from the studies. Meta-analysis was conducted when there was sufficient homogenous data. Six RCTs involving 187 chronic stroke patients were identified. Meta-analysis of key outcome measures showed that trunk restraint has a moderate statistically significant effect on improving Fugl-Meyer Upper Extremity (FMA-UE) score, active shoulder flexion, and reduction in trunk displacement during reaching. There was a small, nonsignificant effect of trunk restraint on upper extremity function. Trunk restraint has a moderate effect on reduction of upper extremity impairment in chronic stroke patients, in terms of FMA-UE score, increased shoulder flexion, and reduction in excessive trunk movement during reaching. There is insufficient evidence to demonstrate that trunk restraint improves upper extremity function and reaching trajectory smoothness and straightness in chronic stroke patients. Future research on stroke patients at different phases of recovery and with different levels of upper extremity impairment is recommended. © The Author(s) 2014.

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