Supporting Mature-Aged Students from a Low Socioeconomic Background

ERIC Educational Resources Information Center

Tones, Megan; Fraser, Jenny; Elder, Ruth; White, Katherine M.

2009-01-01

The aim of the current study was to examine mature-aged student perceptions of university support services and barriers to study. Using a mixed methods approach, interviews and focus groups were conducted with mature-aged students to identify barriers to study, knowledge and use of current student support services, and suggestions to improve upon…

People counting in classroom based on video surveillance

NASA Astrophysics Data System (ADS)

Zhang, Quanbin; Huang, Xiang; Su, Juan

2014-11-01

Currently, the switches of the lights and other electronic devices in the classroom are mainly relied on manual control, as a result, many lights are on while no one or only few people in the classroom. It is important to change the current situation and control the electronic devices intelligently according to the number and the distribution of the students in the classroom, so as to reduce the considerable waste of electronic resources. This paper studies the problem of people counting in classroom based on video surveillance. As the camera in the classroom can not get the full shape contour information of bodies and the clear features information of faces, most of the classical algorithms such as the pedestrian detection method based on HOG (histograms of oriented gradient) feature and the face detection method based on machine learning are unable to obtain a satisfied result. A new kind of dual background updating model based on sparse and low-rank matrix decomposition is proposed in this paper, according to the fact that most of the students in the classroom are almost in stationary state and there are body movement occasionally. Firstly, combining the frame difference with the sparse and low-rank matrix decomposition to predict the moving areas, and updating the background model with different parameters according to the positional relationship between the pixels of current video frame and the predicted motion regions. Secondly, the regions of moving objects are determined based on the updated background using the background subtraction method. Finally, some operations including binarization, median filtering and morphology processing, connected component detection, etc. are performed on the regions acquired by the background subtraction, in order to induce the effects of the noise and obtain the number of people in the classroom. The experiment results show the validity of the algorithm of people counting.

ViBe: a universal background subtraction algorithm for video sequences.

PubMed

Barnich, Olivier; Van Droogenbroeck, Marc

2011-06-01

This paper presents a technique for motion detection that incorporates several innovative mechanisms. For example, our proposed technique stores, for each pixel, a set of values taken in the past at the same location or in the neighborhood. It then compares this set to the current pixel value in order to determine whether that pixel belongs to the background, and adapts the model by choosing randomly which values to substitute from the background model. This approach differs from those based upon the classical belief that the oldest values should be replaced first. Finally, when the pixel is found to be part of the background, its value is propagated into the background model of a neighboring pixel. We describe our method in full details (including pseudo-code and the parameter values used) and compare it to other background subtraction techniques. Efficiency figures show that our method outperforms recent and proven state-of-the-art methods in terms of both computation speed and detection rate. We also analyze the performance of a downscaled version of our algorithm to the absolute minimum of one comparison and one byte of memory per pixel. It appears that even such a simplified version of our algorithm performs better than mainstream techniques.

Gaussian Multiscale Aggregation Applied to Segmentation in Hand Biometrics

PubMed Central

de Santos Sierra, Alberto; Ávila, Carmen Sánchez; Casanova, Javier Guerra; del Pozo, Gonzalo Bailador

2011-01-01

This paper presents an image segmentation algorithm based on Gaussian multiscale aggregation oriented to hand biometric applications. The method is able to isolate the hand from a wide variety of background textures such as carpets, fabric, glass, grass, soil or stones. The evaluation was carried out by using a publicly available synthetic database with 408,000 hand images in different backgrounds, comparing the performance in terms of accuracy and computational cost to two competitive segmentation methods existing in literature, namely Lossy Data Compression (LDC) and Normalized Cuts (NCuts). The results highlight that the proposed method outperforms current competitive segmentation methods with regard to computational cost, time performance, accuracy and memory usage. PMID:22247658

Gaussian multiscale aggregation applied to segmentation in hand biometrics.

PubMed

de Santos Sierra, Alberto; Avila, Carmen Sánchez; Casanova, Javier Guerra; del Pozo, Gonzalo Bailador

2011-01-01

This paper presents an image segmentation algorithm based on Gaussian multiscale aggregation oriented to hand biometric applications. The method is able to isolate the hand from a wide variety of background textures such as carpets, fabric, glass, grass, soil or stones. The evaluation was carried out by using a publicly available synthetic database with 408,000 hand images in different backgrounds, comparing the performance in terms of accuracy and computational cost to two competitive segmentation methods existing in literature, namely Lossy Data Compression (LDC) and Normalized Cuts (NCuts). The results highlight that the proposed method outperforms current competitive segmentation methods with regard to computational cost, time performance, accuracy and memory usage.

Enumerating viruses by using fluorescence and the nature of the nonviral background fraction.

PubMed

Pollard, Peter C

2012-09-01

Bulk fluorescence measurements could be a faster and cheaper way of enumerating viruses than epifluorescence microscopy, flow cytometry, or transmission electron microscopy (TEM). However, since viruses are not imaged, the background fluorescence compromises the signal, and we know little about its nature. In this paper the size ranges of nucleotides that fluoresce in the presence of SYBR gold were determined for wastewater and a range of freshwater samples using a differential filtration method. Fluorescence excitation-emission matrices (FEEMs) showed that >70% of the SYBR fluorescence was in the <10-nm size fraction (background) and was not associated with intact viruses. This was confirmed using TEM. The use of FEEMs to develop a fluorescence-based method for counting viruses is an approach that is fundamentally different from the epifluorescence microscopy technique used for enumerating viruses. This high fluorescence background is currently overlooked, yet it has had a most pervasive influence on the development of a simple fluorescence-based method for quantifying viral abundance in water.

Background-Modeling-Based Adaptive Prediction for Surveillance Video Coding.

PubMed

Zhang, Xianguo; Huang, Tiejun; Tian, Yonghong; Gao, Wen

2014-02-01

The exponential growth of surveillance videos presents an unprecedented challenge for high-efficiency surveillance video coding technology. Compared with the existing coding standards that were basically developed for generic videos, surveillance video coding should be designed to make the best use of the special characteristics of surveillance videos (e.g., relative static background). To do so, this paper first conducts two analyses on how to improve the background and foreground prediction efficiencies in surveillance video coding. Following the analysis results, we propose a background-modeling-based adaptive prediction (BMAP) method. In this method, all blocks to be encoded are firstly classified into three categories. Then, according to the category of each block, two novel inter predictions are selectively utilized, namely, the background reference prediction (BRP) that uses the background modeled from the original input frames as the long-term reference and the background difference prediction (BDP) that predicts the current data in the background difference domain. For background blocks, the BRP can effectively improve the prediction efficiency using the higher quality background as the reference; whereas for foreground-background-hybrid blocks, the BDP can provide a better reference after subtracting its background pixels. Experimental results show that the BMAP can achieve at least twice the compression ratio on surveillance videos as AVC (MPEG-4 Advanced Video Coding) high profile, yet with a slightly additional encoding complexity. Moreover, for the foreground coding performance, which is crucial to the subjective quality of moving objects in surveillance videos, BMAP also obtains remarkable gains over several state-of-the-art methods.

Skyrmion based universal memory operated by electric current

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

Zang, Jiadong; Chien, Chia-Ling; Li, Yufan

2017-09-26

A method for generating a skyrmion, comprising: depositing a vertical metallic nanopillar electrode on a first side of a helimagnetic thin film, the helimagnetic thin film having a contact on a second side to provide a current drain; injecting a current through the vertical metallic nanopillar electrode to generate a rotating field; and applying a static upward magnetic field perpendicular to the helimagnetic thin film to maintain an FM phase background.

Catheter tracking via online learning for dynamic motion compensation in transcatheter aortic valve implantation.

PubMed

Wang, Peng; Zheng, Yefeng; John, Matthias; Comaniciu, Dorin

2012-01-01

Dynamic overlay of 3D models onto 2D X-ray images has important applications in image guided interventions. In this paper, we present a novel catheter tracking for motion compensation in the Transcatheter Aortic Valve Implantation (TAVI). To address such challenges as catheter shape and appearance changes, occlusions, and distractions from cluttered backgrounds, we present an adaptive linear discriminant learning method to build a measurement model online to distinguish catheters from background. An analytic solution is developed to effectively and efficiently update the discriminant model and to minimize the classification errors between the tracking object and backgrounds. The online learned discriminant model is further combined with an offline learned detector and robust template matching in a Bayesian tracking framework. Quantitative evaluations demonstrate the advantages of this method over current state-of-the-art tracking methods in tracking catheters for clinical applications.

Adapting Individual Psychotherapy for Adults with Intellectual Disabilities: A Comparative Review of the Cognitive-Behavioural and Psychodynamic Literature

ERIC Educational Resources Information Center

Whitehouse, Richard M.; Tudway, Jeremy A.; Look, Roger; Kroese, Biza Stenfert

2006-01-01

Background: Historically, adults with intellectual disabilities have had little access to individual psychotherapy. Over the last 20 years an increasing body of literature has described psychotherapy with this client group and reported methods for adapting traditional psychotherapeutic techniques. Method: The current review identified the…

Physiological Markers of Anxiety Are Increased in Children of Abused Mothers

ERIC Educational Resources Information Center

Jovanovic, Tanja; Smith, Ami; Kamkwalala, Asante; Poole, James; Samples, Tara; Norrholm, Seth D.; Ressler, Kerry J.; Bradley, Bekh

2011-01-01

Background: A growing number of studies indicate that low income, African American men and women living in urban environments are at high risk for trauma exposure, which may have intergenerational effects. The current study employed psychophysiological methods to describe biomarkers of anxiety in children of traumatized mothers. Methods: Study…

Global challenges/chemistry solutions: Promoting personal safety and national security

USDA-ARS?s Scientific Manuscript database

Joe Alper: Can you provide a little background about why there is a need for this type of assay? Mark Carter: Ricin is considered a biosecurity threat agent. A more efficient detection method was required. Joe Alper: How are these type of assays done today, or are current methods unsuitable for ...

Teaching About Women in Hispanic Literature: Current Methods and Materials.

ERIC Educational Resources Information Center

Maier, Carol

Awareness of a new and altered method of teaching literature, similar to that described by Adrienne Rich, grew from the experience of teaching a small introductory course in twentieth century Hispanic women writers to students with diverse language, cultural, and economic backgrounds. Although about half the students were native Spanish speakers,…

Determining the near-surface current profile from measurements of the wave dispersion relation

NASA Astrophysics Data System (ADS)

Smeltzer, Benjamin; Maxwell, Peter; Aesøy, Eirik; Ellingsen, Simen

2017-11-01

The current-induced Doppler shifts of waves can yield information about the background mean flow, providing an attractive method of inferring the current profile in the upper layer of the ocean. We present measurements of waves propagating on shear currents in a laboratory water channel, as well as theoretical investigations of inversion techniques for determining the vertical current structure. Spatial and temporal measurements of the free surface profile obtained using a synthetic Schlieren method are analyzed to determine the wave dispersion relation and Doppler shifts as a function of wavelength. The vertical current profile can then be inferred from the Doppler shifts using an inversion algorithm. Most existing algorithms rely on a priori assumptions of the shape of the current profile, and developing a method that uses less stringent assumptions is a focus of this study, allowing for measurement of more general current profiles. The accuracy of current inversion algorithms are evaluated by comparison to measurements of the mean flow profile from particle image velocimetry (PIV), and a discussion of the sensitivity to errors in the Doppler shifts is presented.

Extending the Li&Ma method to include PSF information

NASA Astrophysics Data System (ADS)

Nievas-Rosillo, M.; Contreras, J. L.

2016-02-01

The so called Li&Ma formula is still the most frequently used method for estimating the significance of observations carried out by Imaging Atmospheric Cherenkov Telescopes. In this work a straightforward extension of the method for point sources that profits from the good imaging capabilities of current instruments is proposed. It is based on a likelihood ratio under the assumption of a well-known PSF and a smooth background. Its performance is tested with Monte Carlo simulations based on real observations and its sensitivity is compared to standard methods which do not incorporate PSF information. The gain of significance that can be attributed to the inclusion of the PSF is around 10% and can be boosted if a background model is assumed or a finer binning is used.

Are South African Speech-Language Therapists adequately equipped to assess English Additional Language (EAL) speakers who are from an indigenous linguistic and cultural background? A profile and exploration of the current situation

PubMed Central

Mdlalo, Thandeka; Flack, Penelope

2016-01-01

This article presents the results of a survey conducted on Speech-Language Therapists (SLTs) regarding current practices in the assessment of English Additional Language (EAL) speakers in South Africa. It forms part of the rationale for a broader (PhD) study that critiques the use of assessment instruments on EAL speakers from an indigenous linguistic and cultural background. This article discusses an aspect of the broader research and presents the background, method, findings, discussion and implications of the survey. The results of this survey highlight the challenges of human and material resources to, and the dominance of English in, the profession in South Africa. The findings contribute to understanding critical factors for acquiring reliable and valid assessment results with diverse populations, particularly the implications from a cultural and linguistic perspective. PMID:27247254

Illuminating the Background: Topics in Cosmic Microwave Background Polarization Research

NASA Astrophysics Data System (ADS)

Miller, Nathan J.

The cosmic microwave background provides a wealth of information about the origin and history of the universe. The statistics of the anisotropy and the polarization of the cosmic microwave background, among other things, can tell us about the distribution of matter, the redshift of reionization, and the nature of the primordial uctuations. From the lensing of cosmic microwave background due to intervening matter, we can extract information about neutrinos and the equation of state of dark energy. A measurement of the large angular scale B-mode polarization has been called the "smoking gun" of in ation, a theory that describes a possible early rapid expansion of the universe. The focus of current experiments is to measure this B-mode polarization, while several experiments, such as POLARBEAR, are also looking to measure the lensing of the cosmic microwave background. This dissertation will discuss several different topics in cosmic microwave background polarization research. I will make predictions for future experiments and I will also show analysis for two current experiments, POLARBEAR and BICEP. I will show how beam systematics affect the measurement of cosmological parameters and how well we must limit these systematics in order to get unbiased constraints on cosmological parameters for future experiments. I will discuss a novel way of using the temperature-polarization cross correlation to constrain the amount of inflationary gravitational waves. Through Markov Chain Monte Carlo methods, I will determine how well future experiments will be able to constrain the neutrino masses and their degeneracy parameters. I will show results from current data analysis and calibration being done on the Cedar Flat deployment for the POLARBEAR experiment which is currently being constructed in the Atacama desert in Chile. Finally, I will analyze the claim of detection of cosmological birefringence in the BICEP data and show that there is reason to believe it is due to systematic effects in the data.

On-line Monitoring Device for High-voltage Switch Cabinet Partial Discharge Based on Pulse Current Method

NASA Astrophysics Data System (ADS)

Y Tao, S.; Zhang, X. Z.; Cai, H. W.; Li, P.; Feng, Y.; Zhang, T. C.; Li, J.; Wang, W. S.; Zhang, X. K.

2017-12-01

The pulse current method for partial discharge detection is generally applied in type testing and other off-line tests of electrical equipment at delivery. After intensive analysis of the present situation and existing problems of partial discharge detection in switch cabinets, this paper designed the circuit principle and signal extraction method for partial discharge on-line detection based on a high-voltage presence indicating systems (VPIS), established a high voltage switch cabinet partial discharge on-line detection circuit based on the pulse current method, developed background software integrated with real-time monitoring, judging and analyzing functions, carried out a real discharge simulation test on a real-type partial discharge defect simulation platform of a 10KV switch cabinet, and verified the sensitivity and validity of the high-voltage switch cabinet partial discharge on-line monitoring device based on the pulse current method. The study presented in this paper is of great significance for switch cabinet maintenance and theoretical study on pulse current method on-line detection, and has provided a good implementation method for partial discharge on-line monitoring devices for 10KV distribution network equipment.

End-of-Life Care and Dying: Issues Raised by Staff Supporting Older People with Intellectual Disability in Community Living Services

ERIC Educational Resources Information Center

Wiese, Michele; Stancliffe, Roger J.; Balandin, Susan; Howarth, Glennys; Dew, Angela

2012-01-01

Background: The aim of this study was to explore the current status of end-of-life care and dying of people with intellectual disability based on the experiences of staff in community living services. Materials and Methods: Focus groups and individual interviews were conducted, guided by grounded theory methodology. Results: The current status of…

Laser-induced fluorescence imaging of bacteria

NASA Astrophysics Data System (ADS)

Hilton, Peter J.

1998-12-01

This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

Ionization signals from diamond detectors in fast-neutron fields

NASA Astrophysics Data System (ADS)

Weiss, C.; Frais-Kölbl, H.; Griesmayer, E.; Kavrigin, P.

2016-09-01

In this paper we introduce a novel analysis technique for measurements with single-crystal chemical vapor deposition (sCVD) diamond detectors in fast-neutron fields. This method exploits the unique electronic property of sCVD diamond sensors that the signal shape of the detector current is directly proportional to the initial ionization profile. In fast-neutron fields the diamond sensor acts simultaneously as target and sensor. The interaction of neutrons with the stable isotopes 12 C and 13 C is of interest for fast-neutron diagnostics. The measured signal shapes of detector current pulses are used to identify individual types of interactions in the diamond with the goal to select neutron-induced reactions in the diamond and to suppress neutron-induced background reactions as well as γ-background. The method is verified with experimental data from a measurement in a 14.3 MeV neutron beam at JRC-IRMM, Geel/Belgium, where the 13C(n, α)10Be reaction was successfully extracted from the dominating background of recoil protons and γ-rays and the energy resolution of the 12C(n, α)9Be reaction was substantially improved. The presented analysis technique is especially relevant for diagnostics in harsh radiation environments, like fission and fusion reactors. It allows to extract the neutron spectrum from the background, and is particularly applicable to neutron flux monitoring and neutron spectroscopy.

Evaluation of counting methods for oceanic radium-228

NASA Astrophysics Data System (ADS)

Orr, James C.

1988-07-01

Measurement of open ocean 228Ra is difficult, typically requiring at least 200 L of seawater. The burden of collecting and processing these large-volume samples severely limits the widespread use of this promising tracer. To use smaller-volume samples, a more sensitive means of analysis is required. To seek out new and improved counting method(s), conventional 228Ra counting methods have been compared with some promising techniques which are currently used for other radionuclides. Of the conventional methods, α spectrometry possesses the highest efficiency (3-9%) and lowest background (0.0015 cpm), but it suffers from the need for complex chemical processing after sampling and the need to allow about 1 year for adequate ingrowth of 228Th granddaughter. The other two conventional counting methods measure the short-lived 228Ac daughter while it remains supported by 228Ra, thereby avoiding the complex sample processing and the long delay before counting. The first of these, high-resolution γ spectrometry, offers the simplest processing and an efficiency (4.8%) comparable to α spectrometry; yet its high background (0.16 cpm) and substantial equipment cost (˜30,000) limit its widespread use. The second no-wait method, β-γ coincidence spectrometry, also offers comparable efficiency (5.3%), but it possesses both lower background (0.0054 cpm) and lower initial cost (˜12,000). Three new (i.e., untried for 228Ra) techniques all seem to promise about a fivefold increase in efficiency over conventional methods. By employing liquid scintillation methods, both α spectrometry and β-γ coincidence spectrometry can improve their counter efficiency while retaining low background. The third new 228Ra counting method could be adapted from a technique which measures 224Ra by 220Rn emanation. After allowing for ingrowth and then counting for the 224Ra great-granddaughter, 228Ra could be back calculated, thereby yielding a method with high efficiency, where no sample processing is required. The efficiency and background of each of the three new methods have been estimated and are compared with those of the three methods currently employed to measure oceanic 228Ra. From efficiency and background, the relative figure of merit and the detection limit have been determined for each of the six counters. These data suggest that the new counting methods have the potential to measure most 228Ra samples with just 30 L of seawater, to better than 5% precision. Not only would this reduce the time, effort, and expense involved in sample collection, but 228Ra could then be measured on many small-volume samples (20-30 L) previously collected with only 226Ra in mind. By measuring 228Ra quantitatively on such small-volume samples, three analyses (large-volume 228Ra, large-volume 226Ra, and small-volume 226Ra) could be reduced to one, thereby dramatically improving analytical precision.

Basics of Bayesian methods.

PubMed

Ghosh, Sujit K

2010-01-01

Bayesian methods are rapidly becoming popular tools for making statistical inference in various fields of science including biology, engineering, finance, and genetics. One of the key aspects of Bayesian inferential method is its logical foundation that provides a coherent framework to utilize not only empirical but also scientific information available to a researcher. Prior knowledge arising from scientific background, expert judgment, or previously collected data is used to build a prior distribution which is then combined with current data via the likelihood function to characterize the current state of knowledge using the so-called posterior distribution. Bayesian methods allow the use of models of complex physical phenomena that were previously too difficult to estimate (e.g., using asymptotic approximations). Bayesian methods offer a means of more fully understanding issues that are central to many practical problems by allowing researchers to build integrated models based on hierarchical conditional distributions that can be estimated even with limited amounts of data. Furthermore, advances in numerical integration methods, particularly those based on Monte Carlo methods, have made it possible to compute the optimal Bayes estimators. However, there is a reasonably wide gap between the background of the empirically trained scientists and the full weight of Bayesian statistical inference. Hence, one of the goals of this chapter is to bridge the gap by offering elementary to advanced concepts that emphasize linkages between standard approaches and full probability modeling via Bayesian methods.

Recursive least squares background prediction of univariate syndromic surveillance data

PubMed Central

2009-01-01

Background Surveillance of univariate syndromic data as a means of potential indicator of developing public health conditions has been used extensively. This paper aims to improve the performance of detecting outbreaks by using a background forecasting algorithm based on the adaptive recursive least squares method combined with a novel treatment of the Day of the Week effect. Methods Previous work by the first author has suggested that univariate recursive least squares analysis of syndromic data can be used to characterize the background upon which a prediction and detection component of a biosurvellance system may be built. An adaptive implementation is used to deal with data non-stationarity. In this paper we develop and implement the RLS method for background estimation of univariate data. The distinctly dissimilar distribution of data for different days of the week, however, can affect filter implementations adversely, and so a novel procedure based on linear transformations of the sorted values of the daily counts is introduced. Seven-days ahead daily predicted counts are used as background estimates. A signal injection procedure is used to examine the integrated algorithm's ability to detect synthetic anomalies in real syndromic time series. We compare the method to a baseline CDC forecasting algorithm known as the W2 method. Results We present detection results in the form of Receiver Operating Characteristic curve values for four different injected signal to noise ratios using 16 sets of syndromic data. We find improvements in the false alarm probabilities when compared to the baseline W2 background forecasts. Conclusion The current paper introduces a prediction approach for city-level biosurveillance data streams such as time series of outpatient clinic visits and sales of over-the-counter remedies. This approach uses RLS filters modified by a correction for the weekly patterns often seen in these data series, and a threshold detection algorithm from the residuals of the RLS forecasts. We compare the detection performance of this algorithm to the W2 method recently implemented at CDC. The modified RLS method gives consistently better sensitivity at multiple background alert rates, and we recommend that it should be considered for routine application in bio-surveillance systems. PMID:19149886

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis

PubMed Central

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described. PMID:28542338

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis.

PubMed

Young, Brian; King, Jonathan L; Budowle, Bruce; Armogida, Luigi

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described.

Knowledge-in-Action between Rules and Experiences: Lessons from High Performance Sport for Physical Education

ERIC Educational Resources Information Center

Loquet, Monique

2011-01-01

Background: Most of the current work in physical education champions a culture of "off-beat" educational practices over more traditional and accepted methods. However, in this paper we claim that in order for a student to gain a quality physical education, practices and methods used for novices need to be closely linked to those used by…

Integrated bio-fluorescence sensor.

PubMed

Thrush, Evan; Levi, Ofer; Ha, Wonill; Wang, Ke; Smith, Stephen J; Harris, James S

2003-09-26

Due to the recent explosion in optoelectronics for telecommunication applications, novel optoelectronic sensing structures can now be realized. In this work, we explore the integration of optoelectronic components towards miniature and portable fluorescence sensors. The integration of these micro-fabricated sensors with microfluidics and capillary networks may reduce the cost and complexity of current research instruments and open up a world of new applications in portable biological analysis systems. A novel optoelectronic design that capitalizes on current vertical-cavity surface-emitting laser (VCSEL) technology is explored. Specifically, VCSELs, optical emission filters and PIN photodetectors are fabricated as part of a monolithically integrated near-infrared fluorescence detection system. High-performance lasers and photodetectors have been characterized and integrated to form a complete sensor. Experimental results show that sensor sensitivity is limited by laser background. The laser background is caused by spontaneous emission emitted from the side of the VCSEL excitation source. Laser background will limit sensitivity in most integrated sensing designs due to locating excitation sources and photodetectors in such close proximity, and methods are proposed to reduce the laser background in such designs so that practical fluorescent detection limits can be achieved.

Improving estimates of the number of `fake' leptons and other mis-reconstructed objects in hadron collider events: BoB's your UNCLE

NASA Astrophysics Data System (ADS)

Gillam, Thomas P. S.; Lester, Christopher G.

2014-11-01

We consider current and alternative approaches to setting limits on new physics signals having backgrounds from misidentified objects; for example jets misidentified as leptons, b-jets or photons. Many ATLAS and CMS analyses have used a heuristic "matrix method" for estimating the background contribution from such sources. We demonstrate that the matrix method suffers from statistical shortcomings that can adversely affect its ability to set robust limits. A rigorous alternative method is discussed, and is seen to produce fake rate estimates and limits with better qualities, but is found to be too costly to use. Having investigated the nature of the approximations used to derive the matrix method, we propose a third strategy that is seen to marry the speed of the matrix method to the performance and physicality of the more rigorous approach.

Analysis of Electric Vehicle DC High Current Conversion Technology

NASA Astrophysics Data System (ADS)

Yang, Jing; Bai, Jing-fen; Lin, Fan-tao; Lu, Da

2017-05-01

Based on the background of electric vehicles, it is elaborated the necessity about electric energy accurate metering of electric vehicle power batteries, and it is analyzed about the charging and discharging characteristics of power batteries. It is needed a DC large current converter to realize accurate calibration of power batteries electric energy metering. Several kinds of measuring methods are analyzed based on shunts and magnetic induction principle in detail. It is put forward power batteries charge and discharge calibration system principle, and it is simulated and analyzed ripple waves containing rate and harmonic waves containing rate of power batteries AC side and DC side. It is put forward suitable DC large current measurement methods of power batteries by comparing different measurement principles and it is looked forward the DC large current measurement techniques.

Evaluation of background radiation dose contributions in the United Arab Emirates.

PubMed

Goddard, Braden; Bosc, Emmanuel; Al Hasani, Sarra; Lloyd, Cody

2018-09-01

The natural background radiation consists of three main components; cosmic, terrestrial, and skyshine. Although there are currently methods available to measure the total dose rate from background radiation, no established methods exist that allow for the measurement of each component the background radiation. This analysis consists of a unique methodology in which the dose rate contribution from each component of the natural background radiation is measured and calculated. This project evaluates the natural background dose rate in the Abu Dhabi City region from all three of these components using the developed methodology. Evaluating and understanding the different components of background radiation provides a baseline allowing for the detection, and possibly attribution, of elevated radiation levels. Measurements using a high-pressure ion chamber with different shielding configurations and two offshore measurements provided dose rate information that were attributed to the different components of the background radiation. Additional spectral information was obtained using an HPGe detector to verify and quantify the presence of terrestrial radionuclides. By evaluating the dose rates of the different shielding configurations the comic, terrestrial, and skyshine contribution in the Abu Dhabi City region were determined to be 33.0 ± 1.7, 15.7 ± 2.5, and 2.4 ± 2.1 nSv/h, respectively. Copyright © 2018. Published by Elsevier Ltd.

Monte Carlo Bayesian inference on a statistical model of sub-gridcolumn moisture variability using high-resolution cloud observations. Part 1: Method.

PubMed

Norris, Peter M; da Silva, Arlindo M

2016-07-01

A method is presented to constrain a statistical model of sub-gridcolumn moisture variability using high-resolution satellite cloud data. The method can be used for large-scale model parameter estimation or cloud data assimilation. The gridcolumn model includes assumed probability density function (PDF) intra-layer horizontal variability and a copula-based inter-layer correlation model. The observables used in the current study are Moderate Resolution Imaging Spectroradiometer (MODIS) cloud-top pressure, brightness temperature and cloud optical thickness, but the method should be extensible to direct cloudy radiance assimilation for a small number of channels. The algorithm is a form of Bayesian inference with a Markov chain Monte Carlo (MCMC) approach to characterizing the posterior distribution. This approach is especially useful in cases where the background state is clear but cloudy observations exist. In traditional linearized data assimilation methods, a subsaturated background cannot produce clouds via any infinitesimal equilibrium perturbation, but the Monte Carlo approach is not gradient-based and allows jumps into regions of non-zero cloud probability. The current study uses a skewed-triangle distribution for layer moisture. The article also includes a discussion of the Metropolis and multiple-try Metropolis versions of MCMC.

Monte Carlo Bayesian Inference on a Statistical Model of Sub-Gridcolumn Moisture Variability Using High-Resolution Cloud Observations. Part 1: Method

NASA Technical Reports Server (NTRS)

Norris, Peter M.; Da Silva, Arlindo M.

2016-01-01

A method is presented to constrain a statistical model of sub-gridcolumn moisture variability using high-resolution satellite cloud data. The method can be used for large-scale model parameter estimation or cloud data assimilation. The gridcolumn model includes assumed probability density function (PDF) intra-layer horizontal variability and a copula-based inter-layer correlation model. The observables used in the current study are Moderate Resolution Imaging Spectroradiometer (MODIS) cloud-top pressure, brightness temperature and cloud optical thickness, but the method should be extensible to direct cloudy radiance assimilation for a small number of channels. The algorithm is a form of Bayesian inference with a Markov chain Monte Carlo (MCMC) approach to characterizing the posterior distribution. This approach is especially useful in cases where the background state is clear but cloudy observations exist. In traditional linearized data assimilation methods, a subsaturated background cannot produce clouds via any infinitesimal equilibrium perturbation, but the Monte Carlo approach is not gradient-based and allows jumps into regions of non-zero cloud probability. The current study uses a skewed-triangle distribution for layer moisture. The article also includes a discussion of the Metropolis and multiple-try Metropolis versions of MCMC.

Monte Carlo Bayesian inference on a statistical model of sub-gridcolumn moisture variability using high-resolution cloud observations. Part 1: Method

PubMed Central

Norris, Peter M.; da Silva, Arlindo M.

2018-01-01

A method is presented to constrain a statistical model of sub-gridcolumn moisture variability using high-resolution satellite cloud data. The method can be used for large-scale model parameter estimation or cloud data assimilation. The gridcolumn model includes assumed probability density function (PDF) intra-layer horizontal variability and a copula-based inter-layer correlation model. The observables used in the current study are Moderate Resolution Imaging Spectroradiometer (MODIS) cloud-top pressure, brightness temperature and cloud optical thickness, but the method should be extensible to direct cloudy radiance assimilation for a small number of channels. The algorithm is a form of Bayesian inference with a Markov chain Monte Carlo (MCMC) approach to characterizing the posterior distribution. This approach is especially useful in cases where the background state is clear but cloudy observations exist. In traditional linearized data assimilation methods, a subsaturated background cannot produce clouds via any infinitesimal equilibrium perturbation, but the Monte Carlo approach is not gradient-based and allows jumps into regions of non-zero cloud probability. The current study uses a skewed-triangle distribution for layer moisture. The article also includes a discussion of the Metropolis and multiple-try Metropolis versions of MCMC. PMID:29618847

Removal of Differential Capacitive Interferences in Fast-Scan Cyclic Voltammetry.

PubMed

Johnson, Justin A; Hobbs, Caddy N; Wightman, R Mark

2017-06-06

Due to its high spatiotemporal resolution, fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes enables the localized in vivo monitoring of subsecond fluctuations in electroactive neurotransmitter concentrations. In practice, resolution of the analytical signal relies on digital background subtraction for removal of the large current due to charging of the electrical double layer as well as surface faradaic reactions. However, fluctuations in this background current often occur with changes in the electrode state or ionic environment, leading to nonspecific contributions to the FSCV data that confound data analysis. Here, we both explore the origin of such shifts seen with local changes in cations and develop a model to account for their shape. Further, we describe a convolution-based method for removal of the differential capacitive contributions to the FSCV current. The method relies on the use of a small-amplitude pulse made prior to the FSCV sweep that probes the impedance of the system. To predict the nonfaradaic current response to the voltammetric sweep, the step current response is differentiated to provide an estimate of the system's impulse response function and is used to convolute the applied waveform. The generated prediction is then subtracted from the observed current to the voltammetric sweep, removing artifacts associated with electrode impedance changes. The technique is demonstrated to remove select contributions from capacitive characteristics changes of the electrode both in vitro (i.e., in flow-injection analysis) and in vivo (i.e., during a spreading depression event in an anesthetized rat).

Background recovery via motion-based robust principal component analysis with matrix factorization

NASA Astrophysics Data System (ADS)

Pan, Peng; Wang, Yongli; Zhou, Mingyuan; Sun, Zhipeng; He, Guoping

2018-03-01

Background recovery is a key technique in video analysis, but it still suffers from many challenges, such as camouflage, lighting changes, and diverse types of image noise. Robust principal component analysis (RPCA), which aims to recover a low-rank matrix and a sparse matrix, is a general framework for background recovery. The nuclear norm is widely used as a convex surrogate for the rank function in RPCA, which requires computing the singular value decomposition (SVD), a task that is increasingly costly as matrix sizes and ranks increase. However, matrix factorization greatly reduces the dimension of the matrix for which the SVD must be computed. Motion information has been shown to improve low-rank matrix recovery in RPCA, but this method still finds it difficult to handle original video data sets because of its batch-mode formulation and implementation. Hence, in this paper, we propose a motion-assisted RPCA model with matrix factorization (FM-RPCA) for background recovery. Moreover, an efficient linear alternating direction method of multipliers with a matrix factorization (FL-ADM) algorithm is designed for solving the proposed FM-RPCA model. Experimental results illustrate that the method provides stable results and is more efficient than the current state-of-the-art algorithms.

Challenges in Building Disease-Based National Health Accounts

PubMed Central

Rosen, Allison B.; Cutler, David M.

2012-01-01

Background Measuring spending on diseases is critical to assessing the value of medical care. Objective To review the current state of cost of illness (COI) estimation methods, identifying their strengths, limitations and uses. We briefly describe the current National Health Expenditure Accounts (NHEA), and then go on to discuss the addition of COI estimation to the NHEA. Conclusion Recommendations are made for future research aimed at identifying the best methods for developing and using disease-based national health accounts to optimize the information available to policymakers as they struggle with difficult resource allocation decisions. PMID:19536017

Sustainable environmental flow management in an agricultural watershed in northeast Kansas

EPA Science Inventory

Background/Question/Methods The Delaware watershed, an area of land in northeast Kansas of over 1110 square miles, has degraded water quality due to intensive cultivation of crops and subsequent nutrient enrichment and erosion. The current conditions may be further aggravated by ...

Neuronopathic Lysosomal Storage Diseases: Clinical and Pathologic Findings

ERIC Educational Resources Information Center

Prada, Carlos E.; Grabowski, Gregory A.

2013-01-01

Background: The lysosomal--autophagocytic system diseases (LASDs) affect multiple body systems including the central nervous system (CNS). The progressive CNS pathology has its onset at different ages, leading to neurodegeneration and early death. Methods: Literature review provided insight into the current clinical neurological findings,…

Method and apparatus for monitoring machine performance

DOEpatents

Smith, Stephen F.; Castleberry, Kimberly N.

1996-01-01

Machine operating conditions can be monitored by analyzing, in either the time or frequency domain, the spectral components of the motor current. Changes in the electric background noise, induced by mechanical variations in the machine, are correlated to changes in the operating parameters of the machine.

Monte-Carlo background simulations of present and future detectors in x-ray astronomy

NASA Astrophysics Data System (ADS)

Tenzer, C.; Kendziorra, E.; Santangelo, A.

2008-07-01

Reaching a low-level and well understood internal instrumental background is crucial for the scientific performance of an X-ray detector and, therefore, a main objective of the instrument designers. Monte-Carlo simulations of the physics processes and interactions taking place in a space-based X-ray detector as a result of its orbital environment can be applied to explain the measured background of existing missions. They are thus an excellent tool to predict and optimize the background of future observatories. Weak points of a design and the main sources of the background can be identified and methods to reduce them can be implemented and studied within the simulations. Using the Geant4 Monte-Carlo toolkit, we have created a simulation environment for space-based detectors and we present results of such background simulations for XMM-Newton's EPIC pn-CCD camera. The environment is also currently used to estimate and optimize the background of the future instruments Simbol-X and eRosita.

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

PubMed

Kashuba, Corinna M; Benson, James D; Critser, John K

2014-04-01

The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. Copyright © 2014 Elsevier Inc. All rights reserved.

Design of Low Power CMOS Read-Out with TDI Function for Infrared Linear Photodiode Array Detectors

NASA Technical Reports Server (NTRS)

Vizcaino, Paul; Ramirez-Angulo, Jaime; Patel, Umesh D.

2007-01-01

A new low voltage CMOS infrared readout circuit using the buffer-direct injection method is presented. It uses a single supply voltage of 1.8 volts and a bias current of 1uA. The time-delay integration technique is used to increase the signal to noise ratio. A current memory circuit with faulty diode detection is used to remove dark current for background compensation and to disable a photodiode in a cell if detected as faulty. Simulations are shown that verify the circuit that is currently in fabrication in 0.5ym CMOS technology.

Overview of an Advanced Hypersonic Structural Concept Test Program

NASA Technical Reports Server (NTRS)

Stephens, Craig A.; Hudson, Larry D.; Piazza, Anthony

2007-01-01

This viewgraph presentation provides an overview of hypersonics M&S advanced structural concepts development and experimental methods. The discussion on concepts development includes the background, task objectives, test plan, and current status of the C/SiC Ruddervator Subcomponent Test Article (RSTA). The discussion of experimental methods examines instrumentation needs, sensors of interest, and examples of ongoing efforts in the development of extreme environment sensors.

A baseline drift detrending technique for fast scan cyclic voltammetry.

PubMed

DeWaele, Mark; Oh, Yoonbae; Park, Cheonho; Kang, Yu Min; Shin, Hojin; Blaha, Charles D; Bennet, Kevin E; Kim, In Young; Lee, Kendall H; Jang, Dong Pyo

2017-11-06

Fast scan cyclic voltammetry (FSCV) has been commonly used to measure extracellular neurotransmitter concentrations in the brain. Due to the unstable nature of the background currents inherent in FSCV measurements, analysis of FSCV data is limited to very short amounts of time using traditional background subtraction. In this paper, we propose the use of a zero-phase high pass filter (HPF) as the means to remove the background drift. Instead of the traditional method of low pass filtering across voltammograms to increase the signal to noise ratio, a HPF with a low cutoff frequency was applied to the temporal dataset at each voltage point to remove the background drift. As a result, the HPF utilizing cutoff frequencies between 0.001 Hz and 0.01 Hz could be effectively used to a set of FSCV data for removing the drifting patterns while preserving the temporal kinetics of the phasic dopamine response recorded in vivo. In addition, compared to a drift removal method using principal component analysis, this was found to be significantly more effective in reducing the drift (unpaired t-test p < 0.0001, t = 10.88) when applied to data collected from Tris buffer over 24 hours although a drift removal method using principal component analysis also showed the effective background drift reduction. The HPF was also applied to 5 hours of FSCV in vivo data. Electrically evoked dopamine peaks, observed in the nucleus accumbens, were clearly visible even without background subtraction. This technique provides a new, simple, and yet robust, approach to analyse FSCV data with an unstable background.

Monitoring In Vivo Changes in Tonic Extracellular Dopamine Level by Charge-Balancing Multiple Waveform Fast-Scan Cyclic Voltammetry.

PubMed

Oh, Yoonbae; Park, Cheonho; Kim, Do Hyoung; Shin, Hojin; Kang, Yu Min; DeWaele, Mark; Lee, Jeyeon; Min, Hoon-Ki; Blaha, Charles D; Bennet, Kevin E; Kim, In Young; Lee, Kendall H; Jang, Dong Pyo

2016-11-15

Dopamine (DA) modulates central neuronal activity through both phasic (second to second) and tonic (minutes to hours) terminal release. Conventional fast-scan cyclic voltammetry (FSCV), in combination with carbon fiber microelectrodes, has been used to measure phasic DA release in vivo by adopting a background subtraction procedure to remove background capacitive currents. However, measuring tonic changes in DA concentrations using conventional FSCV has been difficult because background capacitive currents are inherently unstable over long recording periods. To measure tonic changes in DA concentrations over several hours, we applied a novel charge-balancing multiple waveform FSCV (CBM-FSCV), combined with a dual background subtraction technique, to minimize temporal variations in background capacitive currents. Using this method, in vitro, charge variations from a reference time point were nearly zero for 48 h, whereas with conventional background subtraction, charge variations progressively increased. CBM-FSCV also demonstrated a high selectivity against 3,4-dihydroxyphenylacetic acid and ascorbic acid, two major chemical interferents in the brain, yielding a sensitivity of 85.40 ± 14.30 nA/μM and limit of detection of 5.8 ± 0.9 nM for DA while maintaining selectivity. Recorded in vivo by CBM-FSCV, pharmacological inhibition of DA reuptake (nomifensine) resulted in a 235 ± 60 nM increase in tonic extracellular DA concentrations, while inhibition of DA synthesis (α-methyl-dl-tyrosine) resulted in a 72.5 ± 4.8 nM decrease in DA concentrations over a 2 h period. This study showed that CBM-FSCV may serve as a unique voltammetric technique to monitor relatively slow changes in tonic extracellular DA concentrations in vivo over a prolonged time period.

Defining and Applying a Functionality Approach to Intellectual Disability

ERIC Educational Resources Information Center

Luckasson, R.; Schalock, R. L.

2013-01-01

Background: The current functional models of disability do not adequately incorporate significant changes of the last three decades in our understanding of human functioning, and how the human functioning construct can be applied to clinical functions, professional practices and outcomes evaluation. Methods: The authors synthesise current…

Furfural Induces Reactive Oxygen Species Accumulation and Cellular Damage in Saccharomyces Cerevisiae

USDA-ARS?s Scientific Manuscript database

Background: Biofuels offer a viable alternative to petroleum-based fuel. However, current methods are not sufficient and technology to use lignocellulosic biomass as a fermentation substrate faces several challenges. One challenge is the need of a robust fermentative microorganism that can tolera...

75 FR 28098 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-19

... studying crashes using case-control methods including the Grand Rapids study, (Borkenstein, R.F., Crowther... Federal holidays. SUPPLEMENTARY INFORMATION: Title: Motorcycle Crash Causation Study and Pilot Motorcycle Crash Causes and Outcomes Study. OMB Control #: 2125-0619. Background: Motorcycle injuries and...

Incentive Pay for Remotely Piloted Aircraft Career Fields

DTIC Science & Technology

2012-01-01

Fields C.1. Mathematical Symbols for Non-Stochastic Values and Shock Terms...78 C.2. Mathematical Symbols for Taste and Compensation . . . . . . . . . . . 79 xiii Summary Background and...manning requirement, even with the current incentive pays and reenlistment bonuses. 2 The mathematical foundations, data, and estimation methods for the

Food, Energy, and The Environment: Alternatives for Creating New Lifestyles.

ERIC Educational Resources Information Center

Sorrells, Nancy R.; Pimentel, David

1981-01-01

Provides background information on the interdependency of agriculture and ecological and social systems. Discusses in detail: (1) fossil energy and food production; (2) energy-intensive agriculture and environmental pollution; and (3) methods for developing alternatives. Includes recommendations to conserve fossil energy used in current food…

Ultra-Low Background Measurements Of Decayed Aerosol Filters

NASA Astrophysics Data System (ADS)

Miley, H.

2009-04-01

To experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS), aerosol samples collected on filter media were measured using HPGe spectrometers of varying low-background technology approaches. In this way, realistic estimates of the impact of low-background methodology can be assessed on the Minimum Detectable Activities obtained in systems such as the IMS. The current measurement requirement of stations in the IMS is 30 microBq per cubic meter of air for 140Ba, or about 106 fissions per daily sample. Importantly, this is for a fresh aerosol filter. Decay varying form 3 days to one week reduce the intrinsic background from radon daughters in the sample. Computational estimates of the improvement factor for these decayed filters for underground-based HPGe in clean shielding materials are orders of magnitude less, even when the decay of the isotopes of interest is included.

Cosmic Microwave Background Mapmaking with a Messenger Field

NASA Astrophysics Data System (ADS)

Huffenberger, Kevin M.; Næss, Sigurd K.

2018-01-01

We apply a messenger field method to solve the linear minimum-variance mapmaking equation in the context of Cosmic Microwave Background (CMB) observations. In simulations, the method produces sky maps that converge significantly faster than those from a conjugate gradient descent algorithm with a diagonal preconditioner, even though the computational cost per iteration is similar. The messenger method recovers large scales in the map better than conjugate gradient descent, and yields a lower overall χ2. In the single, pencil beam approximation, each iteration of the messenger mapmaking procedure produces an unbiased map, and the iterations become more optimal as they proceed. A variant of the method can handle differential data or perform deconvolution mapmaking. The messenger method requires no preconditioner, but a high-quality solution needs a cooling parameter to control the convergence. We study the convergence properties of this new method and discuss how the algorithm is feasible for the large data sets of current and future CMB experiments.

Robust constraint on cosmic textures from the cosmic microwave background.

PubMed

Feeney, Stephen M; Johnson, Matthew C; Mortlock, Daniel J; Peiris, Hiranya V

2012-06-15

Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic textures. Textures are a type of topological defect that can be produced during a cosmological phase transition in the early Universe, and which leave characteristic hot and cold spots in the CMB. We apply bayesian methods to carry out a rigorous test of the texture hypothesis, using full-sky data from the Wilkinson Microwave Anisotropy Probe. We conclude that current data do not warrant augmenting the standard cosmological model with textures. We rule out at 95% confidence models that predict more than 6 detectable cosmic textures on the full sky.

MixSIAR: A Bayesian stable isotope mixing model for characterizing intrapopulation niche variation

EPA Science Inventory

Background/Question/Methods The science of stable isotope mixing models has tended towards the development of modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances or syntheses of the current state of the art are published in parity with software packa...

Improving the risk assessment of lipophilic persistent environmental chemicals in breast milk

EPA Science Inventory

BACKGROUND: A breastfeeding infant’s intake of persistent organic pollutants (POPs) may be much greater than his/her mother’s average daily POP exposure. In many cases, current human health risk assessment methods do not account for differences between maternal and infant POP exp...

Easy-Access Services in Low-Threshold Opiate Agonist Maintenance

ERIC Educational Resources Information Center

Hesse, Morten; Pedersen, Mads U.

2008-01-01

Background: There is currently evidence that methadone and buprenorphine maintenance is effective in reducing substance abuse. However, it is not known whether psychosocial support improves the outcome of methadone maintenance in the absence of control measures, such as regular urine testing. Materials and Methods: In a prospective observational…

Label-free SERS detection of Salmonella Typhimurium on DNA aptamer modified AgNR substrates

USDA-ARS?s Scientific Manuscript database

Salmonella Typhimurium is an important foodborne pathogen which causes gastroenteritis in both humans and animals. Currently available rapid methods have relied on antibodies to offer specific recognition of the pathogen from the background. As a substitute of antibodies, nucleic acid aptamers offer...

Paediatric Palliative Care and Intellectual Disability--A Unique Context

ERIC Educational Resources Information Center

Duc, Jacqueline K.; Herbert, Anthony Robert; Heussler, Helen S.

2017-01-01

Background: Paediatric palliative care is a nuanced area of practice with additional complexities in the context of intellectual disability. There is currently minimal research to guide clinicians working in this challenging area of care. Method: This study describes the complex care of children with life-limiting conditions and intellectual…

Understanding Information about Mortality among People with Intellectual and Developmental Disabilities in Canada

ERIC Educational Resources Information Center

Ouellette-Kuntz, Hélène; Shooshtari, Shahin; Balogh, Robert; Martens, Patricia

2015-01-01

Background: This paper reviews what is currently known about mortality among Canadians with intellectual and developmental disabilities and describes opportunities for ongoing monitoring. Methods: In-hospital mortality among adults with intellectual and developmental disabilities in Ontario was examined using hospital data. Mortality was compared…

Protective Factors Based Model for Screening for Posttraumatic Distress in Adolescents

ERIC Educational Resources Information Center

Pat-Horenczyk, Ruth; Kenan, Avraham Max; Achituv, Michal; Bachar, Eytan

2014-01-01

Background: There is growing application of school-based screening to identify post-traumatic distress in students following exposure to trauma. The consensus method is based on self-report questionnaires that assess posttraumatic symptoms, functional impairment, depression or anxiety. Objective: The current research explored the possibility of…

Perceived Credibility and Eyewitness Testimony of Children with Intellectual Disabilities

ERIC Educational Resources Information Center

Henry, L.; Ridley, A.; Perry, J.; Crane, L.

2011-01-01

Background: Although children with intellectual disabilities (ID) often provide accurate witness testimony, jurors tend to perceive their witness statements to be inherently unreliable. Method: The current study explored the free recall transcripts of child witnesses with ID who had watched a video clip, relative to those of typically developing…

Exergame Apps and Physical Activity: The Results of the ZOMBIE Trial

ERIC Educational Resources Information Center

Cowdery, Joan; Majeske, Paul; Frank, Rebecca; Brown, Devin

2015-01-01

Background: Although there are thousands of health and fitness smartphone apps currently available, little research exists regarding the effects of mobile app technology on physical activity behavior. Purpose: The purpose of this study was to test whether Exergame smartphone applications increase physical activity levels. Methods: This was a…

Food Fight: The Battle over Redefining Competitive Foods

ERIC Educational Resources Information Center

Fleischhacker, Sheila

2007-01-01

Background: Environmental and policy influences are potentially the most powerful and yet the least understood strategies for reversing the current childhood obesity epidemic. Methods: This essay focuses on the school lunch environment and examines the key legal and policy factors that affect competitive foods or foods of minimal nutritional value…

Emanuel Miller Lecture: Confusions and Controversies about Asperger Syndrome

ERIC Educational Resources Information Center

Frith, Uta

2004-01-01

Background: Hans Asperger drew attention to individuals who show the core symptoms of autism in the presence of high verbal intelligence. Methods: A review of the literature explores current issues concerning the diagnosis and nature of Asperger syndrome. Results: The behavioural and neurophysiological evidence to date suggests that Asperger…

77 FR 25533 - Agency Requests for Approval of a New Information Collection(s): Human Subjects Experiments...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-30

... observational experiments are being conducted in support of current agency regulatory efforts that contemplate... comments [identified by Docket No. NHTSA- 2012-0046] through one of the following methods: Federal e... Information Collection. Background: NHTSA has initiated research and rulemaking to address these issues...

Children with Phonological Problems: A Survey of Clinical Practice

ERIC Educational Resources Information Center

Joffe, Victoria; Pring, T.

2008-01-01

Background: Children with phonological problems are a significant proportion of many therapists' caseloads. However, little is known about current clinical practice with these children or whether research on the effects of therapy have influenced this practice. Aims: To investigate the methods of assessment and remediation used by therapists…

Do Emotions Spark Interest in Alternative Tobacco Products?

ERIC Educational Resources Information Center

Popova, Lucy; So, Jiyeon; Sangalang, Angeline; Neilands, Torsten B.; Ling, Pamela M.

2017-01-01

Background: Exposure to advertisements for tobacco products and tobacco warning labels evokes emotions. This study evaluated the association of discrete positive and negative emotions with interest in alternative tobacco products. Method: In 2013, 1,226 U.S. adult nonsmokers and current smokers viewed advertisements for moist snuff, snus, and…

COMPARISON OF MYCOBACTERIUM AVIUM ISOLATES FROM DRINKING WATER AND FROM THE POPULATION SERVED BY THE SYSTEM

EPA Science Inventory

Background: Current evidence suggests that drinking water, soil, and produce are potential sources of Mycobacterium avium infections, a pathogen not known to be transmitted person-to-person.

Methods: We sampled water during 2000 - 2002 from a large municipal drinking wate...

A Mixed-Methods Study of Adolescents' Motivation to Read

ERIC Educational Resources Information Center

Troyer, Margaret

2017-01-01

Background: Research has shown that reading motivation is correlated with achievement. Studying motivation in older students is particularly important as reading motivation declines over the course of elementary and middle school. However, current research largely fails to reflect the nuance and complexity of reading motivation, or its variation…

The Latent Structure of Child Depression: A Taxometric Analysis

ERIC Educational Resources Information Center

Richey, J. Anthony; Schmidt, Norman B.; Lonigan, Christopher J.; Phillips, Beth M.; Catanzaro, Salvatore J.; Laurent, Jeff; Gerhardstein, Rebecca R.; Kotov, Roman

2009-01-01

Background: The current study examined the categorical versus continuous nature of child and adolescent depression among three samples of children and adolescents ranging from 5 to 19 years. Methods: Depression was measured using the Children's Depression Inventory (CDI). Indicators derived from the CDI were based on factor analytic research on…

Particle and flow field holography: A critical survey

NASA Technical Reports Server (NTRS)

Trolinger, James D.

1987-01-01

A brief background is provided for the fields of particle and flow visualization holography. A summary of methods currently in use is given, followed by a discussion of more recent and unique applications. The problem of data reduction is discussed. A state of the art summary is then provided with a prognosis of the future of the field. Particle and flow visualization holography are characterized as powerful tools currently in wide use and with significant untapped potential.

Detection of S-Nitrosothiols

PubMed Central

Diers, Anne R.; Keszler, Agnes; Hogg, Neil

2015-01-01

BACKGROUND S-Nitrosothiols have been recognized as biologically-relevant products of nitric oxide that are involved in many of the diverse activities of this free radical. SCOPE OF REVIEW This review serves to discuss current methods for the detection and analysis of protein S-nitrosothiols. The major methods of S-nitrosothiol detection include chemiluminescence-based methods and switch-based methods, each of which comes in various flavors with advantages and caveats. MAJOR CONCLUSIONS The detection of S-nitrosothiols is challenging and prone to many artifacts. Accurate measurements require an understanding of the underlying chemistry of the methods involved and the use of appropriate controls. GENERAL SIGNIFICANCE Nothing is more important to a field of research than robust methodology that is generally trusted. The field of S-Nitrosation has developed such methods but, as S-nitrosothiols are easy to introduce as artifacts, it is vital that current users learn from the lessons of the past. PMID:23988402

Recursive least squares background prediction of univariate syndromic surveillance data.

PubMed

Najmi, Amir-Homayoon; Burkom, Howard

2009-01-16

Surveillance of univariate syndromic data as a means of potential indicator of developing public health conditions has been used extensively. This paper aims to improve the performance of detecting outbreaks by using a background forecasting algorithm based on the adaptive recursive least squares method combined with a novel treatment of the Day of the Week effect. Previous work by the first author has suggested that univariate recursive least squares analysis of syndromic data can be used to characterize the background upon which a prediction and detection component of a biosurvellance system may be built. An adaptive implementation is used to deal with data non-stationarity. In this paper we develop and implement the RLS method for background estimation of univariate data. The distinctly dissimilar distribution of data for different days of the week, however, can affect filter implementations adversely, and so a novel procedure based on linear transformations of the sorted values of the daily counts is introduced. Seven-days ahead daily predicted counts are used as background estimates. A signal injection procedure is used to examine the integrated algorithm's ability to detect synthetic anomalies in real syndromic time series. We compare the method to a baseline CDC forecasting algorithm known as the W2 method. We present detection results in the form of Receiver Operating Characteristic curve values for four different injected signal to noise ratios using 16 sets of syndromic data. We find improvements in the false alarm probabilities when compared to the baseline W2 background forecasts. The current paper introduces a prediction approach for city-level biosurveillance data streams such as time series of outpatient clinic visits and sales of over-the-counter remedies. This approach uses RLS filters modified by a correction for the weekly patterns often seen in these data series, and a threshold detection algorithm from the residuals of the RLS forecasts. We compare the detection performance of this algorithm to the W2 method recently implemented at CDC. The modified RLS method gives consistently better sensitivity at multiple background alert rates, and we recommend that it should be considered for routine application in bio-surveillance systems.

Detection prospects of the cosmic neutrino background

NASA Astrophysics Data System (ADS)

Li, Yu-Feng

2015-04-01

The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015).

Winnowing DNA for rare sequences: highly specific sequence and methylation based enrichment.

PubMed

Thompson, Jason D; Shibahara, Gosuke; Rajan, Sweta; Pel, Joel; Marziali, Andre

2012-01-01

Rare mutations in cell populations are known to be hallmarks of many diseases and cancers. Similarly, differential DNA methylation patterns arise in rare cell populations with diagnostic potential such as fetal cells circulating in maternal blood. Unfortunately, the frequency of alleles with diagnostic potential, relative to wild-type background sequence, is often well below the frequency of errors in currently available methods for sequence analysis, including very high throughput DNA sequencing. We demonstrate a DNA preparation and purification method that through non-linear electrophoretic separation in media containing oligonucleotide probes, achieves 10,000 fold enrichment of target DNA with single nucleotide specificity, and 100 fold enrichment of unmodified methylated DNA differing from the background by the methylation of a single cytosine residue.

Normalization, bias correction, and peak calling for ChIP-seq

PubMed Central

Diaz, Aaron; Park, Kiyoub; Lim, Daniel A.; Song, Jun S.

2012-01-01

Next-generation sequencing is rapidly transforming our ability to profile the transcriptional, genetic, and epigenetic states of a cell. In particular, sequencing DNA from the immunoprecipitation of protein-DNA complexes (ChIP-seq) and methylated DNA (MeDIP-seq) can reveal the locations of protein binding sites and epigenetic modifications. These approaches contain numerous biases which may significantly influence the interpretation of the resulting data. Rigorous computational methods for detecting and removing such biases are still lacking. Also, multi-sample normalization still remains an important open problem. This theoretical paper systematically characterizes the biases and properties of ChIP-seq data by comparing 62 separate publicly available datasets, using rigorous statistical models and signal processing techniques. Statistical methods for separating ChIP-seq signal from background noise, as well as correcting enrichment test statistics for sequence-dependent and sonication biases, are presented. Our method effectively separates reads into signal and background components prior to normalization, improving the signal-to-noise ratio. Moreover, most peak callers currently use a generic null model which suffers from low specificity at the sensitivity level requisite for detecting subtle, but true, ChIP enrichment. The proposed method of determining a cell type-specific null model, which accounts for cell type-specific biases, is shown to be capable of achieving a lower false discovery rate at a given significance threshold than current methods. PMID:22499706

Parameter estimation for the exponential-normal convolution model for background correction of affymetrix GeneChip data.

PubMed

McGee, Monnie; Chen, Zhongxue

2006-01-01

There are many methods of correcting microarray data for non-biological sources of error. Authors routinely supply software or code so that interested analysts can implement their methods. Even with a thorough reading of associated references, it is not always clear how requisite parts of the method are calculated in the software packages. However, it is important to have an understanding of such details, as this understanding is necessary for proper use of the output, or for implementing extensions to the model. In this paper, the calculation of parameter estimates used in Robust Multichip Average (RMA), a popular preprocessing algorithm for Affymetrix GeneChip brand microarrays, is elucidated. The background correction method for RMA assumes that the perfect match (PM) intensities observed result from a convolution of the true signal, assumed to be exponentially distributed, and a background noise component, assumed to have a normal distribution. A conditional expectation is calculated to estimate signal. Estimates of the mean and variance of the normal distribution and the rate parameter of the exponential distribution are needed to calculate this expectation. Simulation studies show that the current estimates are flawed; therefore, new ones are suggested. We examine the performance of preprocessing under the exponential-normal convolution model using several different methods to estimate the parameters.

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

Aalseth, Craig E.; Day, Anthony R.; Fuller, Erin S.

Abstract A new ultra-low-background proportional counter (ULBPC) design was recently developed at Pacific Northwest National Laboratory (PNNL). This design, along with an ultra-low-background counting system (ULBCS) which provides passive and active shielding with radon exclusion, has been developed to complement a new shallow underground laboratory (~30 meters water-equivalent) constructed at PNNL. After these steps to mitigate dominant backgrounds (cosmic rays, external gamma-rays, radioactivity in materials), remaining background events do not exclusively arise from ionization of the proportional counter gas. Digital pulse-shape discrimination (PSD) is thus employed to further improve measurement sensitivity. In this work, a template shape is generated formore » each individual sample measurement of interest, a "self-calibrating" template. Differences in event topology can also cause differences in pulse shape. In this work, the temporal region analyzed for each event is refined to maximize background discrimination while avoiding unwanted sensitivity to event topology. This digital PSD method is applied to sample and background data, and initial measurement results from a biofuel methane sample are presented in the context of low-background measurements currently being developed.« less

The mercedes-benz approach to γ-ray astronomy

NASA Astrophysics Data System (ADS)

Akerlof, Carl W.

1988-02-01

The sensitivity requirements for ground-based γ-ray astronomy are reviewed in the light of the most reliable estimates of stellar fluxes above 100 GeV. Current data strongly favor the construction of detectors with the lowest energy thresholds. Since improvements in angular resolution are limited by shower fluctuations, better methods of rejecting hadronic showers must be found to reliably observe the known astrophysical sources. Several possible methods for reducing this hadronic background are discussed.

Comprehensive evaluation of global energy interconnection development index

NASA Astrophysics Data System (ADS)

Liu, Lin; Zhang, Yi

2018-04-01

Under the background of building global energy interconnection and realizing green and low-carbon development, this article constructed the global energy interconnection development index system which based on the current situation of global energy interconnection development. Through using the entropy method for the weight analysis of global energy interconnection development index, and then using gray correlation method to analyze the selected countries, this article got the global energy interconnection development index ranking and level classification.

Phase Error Correction in Time-Averaged 3D Phase Contrast Magnetic Resonance Imaging of the Cerebral Vasculature

PubMed Central

MacDonald, M. Ethan; Forkert, Nils D.; Pike, G. Bruce; Frayne, Richard

2016-01-01

Purpose Volume flow rate (VFR) measurements based on phase contrast (PC)-magnetic resonance (MR) imaging datasets have spatially varying bias due to eddy current induced phase errors. The purpose of this study was to assess the impact of phase errors in time averaged PC-MR imaging of the cerebral vasculature and explore the effects of three common correction schemes (local bias correction (LBC), local polynomial correction (LPC), and whole brain polynomial correction (WBPC)). Methods Measurements of the eddy current induced phase error from a static phantom were first obtained. In thirty healthy human subjects, the methods were then assessed in background tissue to determine if local phase offsets could be removed. Finally, the techniques were used to correct VFR measurements in cerebral vessels and compared statistically. Results In the phantom, phase error was measured to be <2.1 ml/s per pixel and the bias was reduced with the correction schemes. In background tissue, the bias was significantly reduced, by 65.6% (LBC), 58.4% (LPC) and 47.7% (WBPC) (p < 0.001 across all schemes). Correction did not lead to significantly different VFR measurements in the vessels (p = 0.997). In the vessel measurements, the three correction schemes led to flow measurement differences of -0.04 ± 0.05 ml/s, 0.09 ± 0.16 ml/s, and -0.02 ± 0.06 ml/s. Although there was an improvement in background measurements with correction, there was no statistical difference between the three correction schemes (p = 0.242 in background and p = 0.738 in vessels). Conclusions While eddy current induced phase errors can vary between hardware and sequence configurations, our results showed that the impact is small in a typical brain PC-MR protocol and does not have a significant effect on VFR measurements in cerebral vessels. PMID:26910600

Virtual reality and neuropsychology: upgrading the current tools.

PubMed

Schultheis, Maria T; Himelstein, Jessica; Rizzo, Albert A

2002-10-01

Virtual reality (VR) is an evolving technology that has been applied in various aspects of medicine, including the treatment of phobia disorders, pain distraction interventions, surgical training, and medical education. These applications have served to demonstrate the various assets offered through the use of VR. To provide a background and rationale for the application of VR to neuropsychological assessment. A brief introduction to VR technology and a review of current ongoing neuropsychological research that integrates the use of this technology. VR offers numerous assets that may enhance current neuropsychological assessment protocols and address many of the limitations faced by our traditional methods.

Comparison Between One-Point Calibration and Two-Point Calibration Approaches in a Continuous Glucose Monitoring Algorithm

PubMed Central

Mahmoudi, Zeinab; Johansen, Mette Dencker; Christiansen, Jens Sandahl

2014-01-01

Background: The purpose of this study was to investigate the effect of using a 1-point calibration approach instead of a 2-point calibration approach on the accuracy of a continuous glucose monitoring (CGM) algorithm. Method: A previously published real-time CGM algorithm was compared with its updated version, which used a 1-point calibration instead of a 2-point calibration. In addition, the contribution of the corrective intercept (CI) to the calibration performance was assessed. Finally, the sensor background current was estimated real-time and retrospectively. The study was performed on 132 type 1 diabetes patients. Results: Replacing the 2-point calibration with the 1-point calibration improved the CGM accuracy, with the greatest improvement achieved in hypoglycemia (18.4% median absolute relative differences [MARD] in hypoglycemia for the 2-point calibration, and 12.1% MARD in hypoglycemia for the 1-point calibration). Using 1-point calibration increased the percentage of sensor readings in zone A+B of the Clarke error grid analysis (EGA) in the full glycemic range, and also enhanced hypoglycemia sensitivity. Exclusion of CI from calibration reduced hypoglycemia accuracy, while slightly increased euglycemia accuracy. Both real-time and retrospective estimation of the sensor background current suggest that the background current can be considered zero in the calibration of the SCGM1 sensor. Conclusions: The sensor readings calibrated with the 1-point calibration approach indicated to have higher accuracy than those calibrated with the 2-point calibration approach. PMID:24876420

School hearing screening programme in the UK: practice and performance

PubMed Central

Fonseca, S; Forsyth, H; Neary, W

2005-01-01

Background: Paediatric audiology services and screening programmes are currently under review. Aims and Methods: To investigate current practice and performance of the school hearing screening programme (SHSP) by means of a questionnaire. Results: SHSP was found to detect previously unrecognised hearing loss at low cost. Wide variation in practice was shown, and the majority of services had no computerised system for data collection. Conclusion: There is a need for nationally agreed protocols and quality assurance procedures. PMID:15665168

Investigation of Radio Frequency Discharges and Langmuir Probe Diagnostic Methods in a Fast Flowing Electronegative Background Gas

DTIC Science & Technology

2007-12-01

Pinhero and others, 1998). The Air Force is currently developing the Electric Chemical Oxygen Iodine Laser (ElectriCOIL) system to replace the liquid...chemistry generator currently used in the Air Borne Laser (ABL) system (Zimmerman and others, 2003). The ElectriCOIL system produces in a radio...convected downstream is critical to improving the performance of the ABL system . The use of a second non-self sustained discharge operating at a lower

High-Operating Temperature HgCdTe: A Vision for the Near Future

NASA Astrophysics Data System (ADS)

Lee, D.; Carmody, M.; Piquette, E.; Dreiske, P.; Chen, A.; Yulius, A.; Edwall, D.; Bhargava, S.; Zandian, M.; Tennant, W. E.

2016-09-01

We review recent advances in the HgCdTe material quality and detector performance achieved at Teledyne using molecular beam epitaxy growth and the double-layer planar hetero-junction (DLPH) detector architecture. By using an un-doped, fully depleted absorber, Teledyne's DLPH architecture can be extended for use in high operating temperatures and other applications. We assess the potential achievable performance for long wavelength infrared (LWIR) hetero-junction p-lightly-doped n or p-intrinsic- n (p-i-n) detectors based on recently reported results for 10.7 μm cutoff 1 K × 1 K focal plane arrays (FPAs) tested at temperatures down to 30 K. Variable temperature dark current measurements show that any Shockley-Read-Hall currents in the depletion region of these devices have lifetimes that are reproducibly greater than 100 ms. Under the assumption of comparable lifetimes at higher temperatures, it is predicted that fully-depleted background radiation-limited performance can be expected for 10- μm cutoff detectors from room temperature to well below liquid nitrogen temperatures, with room-temperature dark current nearly 400 times lower than predicted by Rule 07. The hetero-junction p-i-n diode is shown to have numerous other significant potential advantages including minimal or no passivation requirements for pBn-like processing, low 1/ f noise, compatibility with small pixel pitch while maintaining high modulation transfer function, low crosstalk and good quantum efficiency. By appropriate design of the FPA dewar shielding, analysis shows that dark current can theoretically be further reduced below the thermal equilibrium radiative limit. Modeling shows that background radiation-limited LWIR HgCdTe operating with f/1 optics has the potential to operate within √2 of background-limited performance at 215 K. By reducing the background radiation by 2/3 using novel shielding methods, operation with a single-stage thermo-electric-cooler may be possible. If the background radiation can be reduced by 90%, then room-temperature operation is possible.

Enhancing School Asthma Action Plans: Qualitative Results from Southeast Minnesota Beacon Stakeholder Groups

ERIC Educational Resources Information Center

Egginton, Jason S.; Textor, Lauren; Knoebel, Erin; McWilliams, Deborah; Aleman, Marty; Yawn, Barbara

2013-01-01

Background: This study explores ways southeast Minnesota schools currently address asthma problems, identifies areas for improvement, and assesses the potential value of asthma action plans (AAPs) in schools. Methods: Focus groups were used to query stakeholder groups on asthma care in schools. Groups were held separately for elementary school…

Evaluating Reactions and Transfer of Skills from Blackboard Training

ERIC Educational Resources Information Center

Martin, Florence; Brooks, Robin Freeman; Gayford, Matthew C.; Hall, Herman A., IV; Whitfield, Kimberly Y.

2011-01-01

This article describes the methods that were used to evaluate the "Blackboard Basics" and "Teaching in Blackboard" courses that are currently being offered by the Office of e-Learning at a southeastern university in the United States. This report includes a description of the background of this course, the purpose of the…

Usual Source of Cigarettes and Alcohol among US High School Students

ERIC Educational Resources Information Center

Jones, Sherry Everett; Caraballo, Ralph S.

2014-01-01

Background: Cigarette and alcohol use are common among youth. We examined sources of cigarettes and alcohol among youth who were current cigarette and alcohol users. Methods: We analyzed nationally representative data from the 2009 and 2011 national Youth Risk Behavior Surveys--biennial, school-based surveys of high school students in the United…

COMPARISON OF MYCOBACTERIUM AVIUM ISOLATES FROM A DRINKING WATER DISTRIBUTION SYSTEM AND FROM THE POPULATION SERVED BY THE SYSTEM

EPA Science Inventory

Background: Current evidence suggests that drinking water, soil, and produce are potential sources of Mycobacterium avium infections, a pathogen not known to be transmitted person-to-person.

Methods: We sampled water during 2000-2002 from a large municipal drinking water ...

Looking at Movies and Cartoons: Eye-Tracking Evidence from Williams Syndrome and Autism

ERIC Educational Resources Information Center

Riby, D.; Hancock, P. J. B.

2009-01-01

Background: Autism and Williams syndrome (WS) are neuro-developmental disorders associated with distinct social phenotypes. While individuals with autism show a lack of interest in socially important cues, individuals with WS often show increased interest in socially relevant information. Methods: The current eye-tracking study explores how…

Education and Training in Psychiatry in the U.K.

ERIC Educational Resources Information Center

Carney, Stuart; Bhugra, Dinesh K.

2013-01-01

Background/Objective: Recent training and education changes have raised important issues in delivery of psychiatric education at all levels. In this article, the authors describe the current status of mental health education in the training of all doctors and postgraduate training and education in psychiatry in the U.K. Method: The authors explore…

Mortality of People with Intellectual Disabilities in England: A Comparison of Data from Existing Sources

ERIC Educational Resources Information Center

Heslop, Pauline; Glover, Gyles

2015-01-01

Background: At present, there is limited statistical information about mortality of people with intellectual disabilities in England. This study explores the data that are currently available. Materials and Methods: Four recent sources of data about mortality of people with intellectual disabilities in England are reviewed: the Confidential…

Collaborative Academic Training of Psychiatrists and Psychologists in VA and Medical School Settings

ERIC Educational Resources Information Center

Scaturo, Douglas J.; Huszonek, John J.

2009-01-01

Objective: The authors review the background and contemporary strengths of Dean's Committee Veterans Affairs Medical Centers in the collaborative academic training of psychiatrists and psychologists. Methods: The authors discuss the problems and prospects of the current health care environment as it impacts the behavioral health treatment of…

Health Inequity in People with Intellectual Disabilities: From Evidence to Action Applying an Appreciative Inquiry Approach

ERIC Educational Resources Information Center

Naaldenberg, Jenneken; Banks, Roger; Lennox, Nick; Ouellette-Kunz, Hélène; Meijer, Marijke; Lantman-de Valk, Henny van Schrojenstein

2015-01-01

Background: The current understanding of health inequities in people with intellectual disabilities does not readily translate into improvements in health status or health care. To identify opportunities for action, the 2013 IASSIDD health SIRG conference organized ten intensive workshops. Materials and methods: The workshops each addressed…

Service Providers' Perceptions of Active Ageing among Older Adults with Lifelong Intellectual Disabilities

ERIC Educational Resources Information Center

Buys, L.; Aird, R.; Miller, E.

2012-01-01

Background: Considerable attention is currently being directed towards both active ageing and the revising of standards for disability services within Australia and internationally. Yet, to date, no consideration appears to have been given to ways to promote active ageing among older adults with intellectual disabilities (IDs). Methods:…

Patterns of Physical Activity Outside of School Time among Japanese Junior High School Students

ERIC Educational Resources Information Center

He, Li; Ishii, Kaori; Shibata, Ai; Adachi, Minoru; Nonoue, Keiko; Oka, Koichiro

2013-01-01

Background: Physical activity is beneficial for adolescent health. The physical activity patterns of Japanese adolescents are relatively unknown. Therefore, this study aimed to describe the current patterns of physical activity and to identify sex and grade differences among them. Methods: The participants comprised 714 Japanese adolescents aged…

Exploring Student Midwives Creative Expression of the Meaning of Birth

ERIC Educational Resources Information Center

Hall, Jennifer; Mitchell, Mary

2008-01-01

This paper presents a study which explored creative pieces made by student midwives during an educational session on spirituality in relation to midwifery. Background: Exploration of methods of teaching relating to midwifery has been limited, specifically relating to effective learning about spirituality. There is a current expectation in the UK…

Lifestyle and Health Behaviours of Adults with an Intellectual Disability

ERIC Educational Resources Information Center

McGuire, B. E.; Daly, P.; Smyth, F.

2007-01-01

Background: There is currently no published research in Ireland on the health behaviours of adults with an intellectual disability (ID). With an increasing age profile and similar patterns of morbidity to the general population, the ID population would benefit from baseline data from which to establish risk factors. Methods: A questionnaire survey…

Improved HF183 reverse primer and probe for greater analytical sensitivity of human Bacteroides in the environment

EPA Science Inventory

Background: Numerous indicators have been used to assess the presence of fecal pollution, many relying on molecular methods such as qPCR. One of the targets frequently used, the human-associated Bacteroides 16s rRNA region, has several assays in current usage. These assays vary...

Interactions among climate and soil properties influence current and future geographic distribution of an invasive grass in the Chihuahuan Desert

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Lehmann lovegrass (Eragrostis lehmanniana) is an invasive exotic perennial grass throughout the Sonoran Desert. However, in the neighboring Chihuahuan Desert, this species is generally present in low abundance, although data on its geographic distribution are scarce. Our...

Comorbid Depression and Anxiety in Childhood and Adolescent Anorexia Nervosa: Prevalence and Implications for Outcome

ERIC Educational Resources Information Center

Hughes, Elizabeth K.

2012-01-01

Background: Comorbid conditions are common in individuals with anorexia nervosa (AN) and can raise issues for diagnosis, prognosis, and treatment planning. Methods: First, reported prevalence rates for depression and anxiety in children and adolescents with AN were reviewed. Diagnostic issues and current understanding of the temporal onset and…

Prenatal Family Adversity and Maternal Mental Health and Vulnerability to Peer Victimisation at School

ERIC Educational Resources Information Center

Lereya, Suzet Tanya; Wolke, Dieter

2013-01-01

Background: Prenatal stress has been shown to predict persistent behavioural abnormalities in offspring. Unknown is whether prenatal stress makes children more vulnerable to peer victimisation. Methods: The current study is based on the Avon Longitudinal Study of Parents and Children, a prospective community-based study. Family adversity, maternal…

Middle School Students' Perceptions of Safety: A Mixed-Methods Study

ERIC Educational Resources Information Center

Sweeney, Shannon M.; Von Hagen, Leigh Ann

2015-01-01

Background: Active travel to school has been on the decline, despite its beneficial influence on children's current and future well-being. Adults' safety perceptions have been shown to influence children's active travel. Children's perceptions, particularly of safety, may be an important link not only to their present health and travel behaviors,…

Evaluating the Strength of School Tobacco Policies: The Development of a Practical Rating System

ERIC Educational Resources Information Center

Boyce, Jennifer C.; Mueller, Nancy B.; Hogan-Watts, Melissa; Luke, Douglas A.

2009-01-01

Background: School tobacco control policies vary widely in their strength, extensiveness, and enforcement. Currently, no standardized method exists to assess the comprehensiveness of school tobacco policies. The purpose of this study was to develop a new practical rating system for school tobacco policies, assess its reliability, and present…

Development of a Comprehensive Heart Disease Knowledge Questionnaire

ERIC Educational Resources Information Center

Bergman, Hannah E.; Reeve, Bryce B.; Moser, Richard P.; Scholl, Sarah; Klein, William M. P.

2011-01-01

Background: Heart disease is the number one killer of both men and women in the United States, yet a comprehensive and evidence-based heart disease knowledge assessment is currently not available. Purpose: This paper describes the two-phase development of a novel heart disease knowledge questionnaire. Methods: After review and critique of the…

Adapting Compassion Focused Therapy for an Adult with a Learning Disability--A Case Study

ERIC Educational Resources Information Center

Cooper, Rosalind; Frearson, Julia

2017-01-01

Background: Joe was referred to the Community Learning Disabilities Team (CLDT) for support around low mood and overeating. Initial formulation suggested compassion focused therapy (CFT) as an intervention. The evidence base for using CFT with people with learning disabilities is currently limited. Materials and Methods: Adaptations were made to…

Physical Activity and Healthy Eating in the After-School Environment

ERIC Educational Resources Information Center

Coleman, Karen J.; Geller, Karly S.; Rosenkranz, Richard R.; Dzewaltowski, David A.

2008-01-01

Background: No research to date has extensively described moderate and vigorous physical activity (MVPA) and healthful eating (HE) opportunities in the after-school environment. The current study described the quality of the after-school environment for its impact on children's MVPA and HE. Methods: An alliance of 7 elementary schools and Boys and…

Probing Genetic Control of Swine Responses to PRRSV Infection: Current Progress of the PRRS Host Genetics Consortium

USDA-ARS?s Scientific Manuscript database

Background: Understanding the role of host genetics in resistance to porcine reproductive and respiratory syndrome virus (PRRSV) infection, and the effects of PRRS on pig health and related growth, are goals of the PRRS Host Genetics Consortium (PHGC). Methods: The project uses a nursery pig model ...

A Whole School Approach: Collaborative Development of School Health Policies, Processes, and Practices

ERIC Educational Resources Information Center

Hunt, Pete; Barrios, Lisa; Telljohann, Susan K.; Mazyck, Donna

2015-01-01

Background: The Whole School, Whole Community, Whole Child (WSCC) model shows the interrelationship between health and learning and the potential for improving educational outcomes by improving health outcomes. However, current descriptions do not explain how to implement the model. Methods: The existing literature, including scientific articles,…

Detection methods for stochastic gravitational-wave backgrounds: a unified treatment

NASA Astrophysics Data System (ADS)

Romano, Joseph D.; Cornish, Neil. J.

2017-04-01

We review detection methods that are currently in use or have been proposed to search for a stochastic background of gravitational radiation. We consider both Bayesian and frequentist searches using ground-based and space-based laser interferometers, spacecraft Doppler tracking, and pulsar timing arrays; and we allow for anisotropy, non-Gaussianity, and non-standard polarization states. Our focus is on relevant data analysis issues, and not on the particular astrophysical or early Universe sources that might give rise to such backgrounds. We provide a unified treatment of these searches at the level of detector response functions, detection sensitivity curves, and, more generally, at the level of the likelihood function, since the choice of signal and noise models and prior probability distributions are actually what define the search. Pedagogical examples are given whenever possible to compare and contrast different approaches. We have tried to make the article as self-contained and comprehensive as possible, targeting graduate students and new researchers looking to enter this field.

Preconditioner-free Wiener filtering with a dense noise matrix

NASA Astrophysics Data System (ADS)

Huffenberger, Kevin M.

2018-05-01

This work extends the Elsner & Wandelt (2013) iterative method for efficient, preconditioner-free Wiener filtering to cases in which the noise covariance matrix is dense, but can be decomposed into a sum whose parts are sparse in convenient bases. The new method, which uses multiple messenger fields, reproduces Wiener-filter solutions for test problems, and we apply it to a case beyond the reach of the Elsner & Wandelt (2013) method. We compute the Wiener-filter solution for a simulated Cosmic Microwave Background (CMB) map that contains spatially varying, uncorrelated noise, isotropic 1/f noise, and large-scale horizontal stripes (like those caused by atmospheric noise). We discuss simple extensions that can filter contaminated modes or inverse-noise-filter the data. These techniques help to address complications in the noise properties of maps from current and future generations of ground-based Microwave Background experiments, like Advanced ACTPol, Simons Observatory, and CMB-S4.

PET attenuation correction for rigid MR Tx/Rx coils from 176Lu background activity

NASA Astrophysics Data System (ADS)

Lerche, Christoph W.; Kaltsas, Theodoris; Caldeira, Liliana; Scheins, Jürgen; Rota Kops, Elena; Tellmann, Lutz; Pietrzyk, Uwe; Herzog, Hans; Shah, N. Jon

2018-02-01

One challenge for PET-MR hybrid imaging is the correction for attenuation of the 511 keV annihilation radiation by the required RF transmit and/or RF receive coils. Although there are strategies for building PET transparent Tx/Rx coils, such optimised coils still cause significant attenuation of the annihilation radiation leading to artefacts and biases in the reconstructed activity concentrations. We present a straightforward method to measure the attenuation of Tx/Rx coils in simultaneous MR-PET imaging based on the natural 176Lu background contained in the scintillator of the PET detector without the requirement of an external CT scanner or PET scanner with transmission source. The method was evaluated on a prototype 3T MR-BrainPET produced by Siemens Healthcare GmbH, both with phantom studies and with true emission images from patient/volunteer examinations. Furthermore, the count rate stability of the PET scanner and the x-ray properties of the Tx/Rx head coil were investigated. Even without energy extrapolation from the two dominant γ energies of 176Lu to 511 keV, the presented method for attenuation correction, based on the measurement of 176Lu background attenuation, shows slightly better performance than the coil attenuation correction currently used. The coil attenuation correction currently used is based on an external transmission scan with rotating 68Ge sources acquired on a Siemens ECAT HR  +  PET scanner. However, the main advantage of the presented approach is its straightforwardness and ready availability without the need for additional accessories.

Application of the cognitive therapy model to initial crisis assessment.

PubMed

Calvert, Patricia; Palmer, Christine

2003-03-01

This article provides a background to the development of cognitive therapy and cognitive therapeutic skills with a specific focus on the treatment of a depressive episode. It discusses the utility of cognitive therapeutic strategies to the model of crisis theory and initial crisis assessment currently used by the Community Assessment & Treatment Team of Waitemata District Health Board on the North Shore of Auckland, New Zealand. A brief background to cognitive therapy is provided, followed by a comprehensive example of the use of the Socratic questioning method in guiding collaborative assessment and treatment of suicidality by nurses during the initial crisis assessment.

[Mass anomalies of the extremities in anurans].

PubMed

Kovalenko, E E

2000-01-01

The author analyses literature data on anomalies of limbs in Anura. It is shown that published data is usually not enough to discuss either conditions of appearance or the causes of anomalies. Traditional statistical methods does not adequately characterise the frequency of anomalies. The author suggests a new criteria for ascertaining the fact of appearance of mass anomalies. A number of experimental data don't correspond to current theoretical ideas about the nature of anomalies. It is considered to distinguish "background" and "mass" anomalies. "Background" anomalies can not be a good indicator of unfavourable condition of development.

Comparison of fluorescence rejection methods of baseline correction and shifted excitation Raman difference spectroscopy

NASA Astrophysics Data System (ADS)

Cai, Zhijian; Zou, Wenlong; Wu, Jianhong

2017-10-01

Raman spectroscopy has been extensively used in biochemical tests, explosive detection, food additive and environmental pollutants. However, fluorescence disturbance brings a big trouble to the applications of portable Raman spectrometer. Currently, baseline correction and shifted-excitation Raman difference spectroscopy (SERDS) methods are the most prevailing fluorescence suppressing methods. In this paper, we compared the performances of baseline correction and SERDS methods, experimentally and simulatively. Through the comparison, it demonstrates that the baseline correction can get acceptable fluorescence-removed Raman spectrum if the original Raman signal has good signal-to-noise ratio, but it cannot recover the small Raman signals out of large noise background. By using SERDS method, the Raman signals, even very weak compared to fluorescence intensity and noise level, can be clearly extracted, and the fluorescence background can be completely rejected. The Raman spectrum recovered by SERDS has good signal to noise ratio. It's proved that baseline correction is more suitable for large bench-top Raman system with better quality or signal-to-noise ratio, while the SERDS method is more suitable for noisy devices, especially the portable Raman spectrometers.

Progress Towards a Neutral Current $$\\pi^0$$ Cross Section Analysis in the NOvA Near Detector

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

Bowles, Reed; Paley, Jonathan

The NOvA neutrino experiment is attempting to measure properties of neutrinos in order to figure out information about the universe. To detect the signal neutrino interactions, we must determine methods to identify and isolate background events. Research focused on a specific background interaction called a single prong neutral currentmore » $$\\pi^0$$ interaction. To do this, a basic cuts based analysis was performed, followed by feeding data into a multi-variate analysis package using a boosted decision tree (BDT) algorithm. Using the BDT, a a new variable was generated which separates signal and background very efficiently. Further work must still be done in order to continue improving the performance of the BDT. This research is valuable to the field of studying neutrino cross sections as it is a background which will always be present in this type of analysis.« less

Reducing background contributions in fluorescence fluctuation time-traces for single-molecule measurements in solution.

PubMed

Földes-Papp, Zeno; Liao, Shih-Chu Jeff; You, Tiefeng; Barbieri, Beniamino

2009-08-01

We first report on the development of new microscope means that reduce background contributions in fluorescence fluctuation methods: i) excitation shutter, ii) electronic switches, and iii) early and late time-gating. The elements allow for measuring molecules at low analyte concentrations. We first found conditions of early and late time-gating with time-correlated single-photon counting that made the fluorescence signal as bright as possible compared with the fluctuations in the background count rate in a diffraction-limited optical set-up. We measured about a 140-fold increase in the amplitude of autocorrelated fluorescence fluctuations at the lowest analyte concentration of about 15 pM, which gave a signal-to-background advantage of more than two-orders of magnitude. The results of this original article pave the way for single-molecule detection in solution and in live cells without immobilization or hydrodynamic/electrokinetic focusing at longer observation times than are currently available.

Winnowing DNA for Rare Sequences: Highly Specific Sequence and Methylation Based Enrichment

PubMed Central

Thompson, Jason D.; Shibahara, Gosuke; Rajan, Sweta; Pel, Joel; Marziali, Andre

2012-01-01

Rare mutations in cell populations are known to be hallmarks of many diseases and cancers. Similarly, differential DNA methylation patterns arise in rare cell populations with diagnostic potential such as fetal cells circulating in maternal blood. Unfortunately, the frequency of alleles with diagnostic potential, relative to wild-type background sequence, is often well below the frequency of errors in currently available methods for sequence analysis, including very high throughput DNA sequencing. We demonstrate a DNA preparation and purification method that through non-linear electrophoretic separation in media containing oligonucleotide probes, achieves 10,000 fold enrichment of target DNA with single nucleotide specificity, and 100 fold enrichment of unmodified methylated DNA differing from the background by the methylation of a single cytosine residue. PMID:22355378

Revisiting Antipsychotic-induced Akathisia: Current Issues and Prospective Challenges

PubMed Central

Salem, Haitham; Nagpal, Caesa; Pigott, Teresa; Teixeira, Antonio Lucio

2017-01-01

Background: Akathisia continues to be a significant challenge in current neurological and psychiatric practice. Prompt and accurate detection is often difficult and there is a lack of consensus concerning the neurobiological basis of akathisia. No definitive treatment has been established for akathisia despite numerous preclinical and clinical studies. Method: We reviewed antipsychotic-induced akathisia including its clinical presentation, proposed underlying pathophysiology, current and under investigation therapeutic strategies. Conclusion: Despite the initial promise that second generation antipsychotics would be devoid of akathisia effects, this has not been confirmed. Currently, there are limited therapeutic options for the clinical practice and the evidence supporting the most widely used treatments (beta blockers, anticholinergic drugs) is still absent or inconsistent. PMID:27928948

Community detection for fluorescent lifetime microscopy image segmentation

NASA Astrophysics Data System (ADS)

Hu, Dandan; Sarder, Pinaki; Ronhovde, Peter; Achilefu, Samuel; Nussinov, Zohar

2014-03-01

Multiresolution community detection (CD) method has been suggested in a recent work as an efficient method for performing unsupervised segmentation of fluorescence lifetime (FLT) images of live cell images containing fluorescent molecular probes.1 In the current paper, we further explore this method in FLT images of ex vivo tissue slices. The image processing problem is framed as identifying clusters with respective average FLTs against a background or "solvent" in FLT imaging microscopy (FLIM) images derived using NIR fluorescent dyes. We have identified significant multiresolution structures using replica correlations in these images, where such correlations are manifested by information theoretic overlaps of the independent solutions ("replicas") attained using the multiresolution CD method from different starting points. In this paper, our method is found to be more efficient than a current state-of-the-art image segmentation method based on mixture of Gaussian distributions. It offers more than 1:25 times diversity based on Shannon index than the latter method, in selecting clusters with distinct average FLTs in NIR FLIM images.

A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

PubMed Central

Sarver, Scott A.; Gartner, Carlos A.; Chetwani, Nishant; Go, David B.; Dovichi, Norman J.

2014-01-01

A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS has been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were 1 - 2 orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50%, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating improvements in spectral quality may benefit certain compounds, or classes of compounds, on an individual basis. PMID:24464359

Impingement-Current-Erosion Characteristics of Accelerator Grids on Two-Grid Ion Thrusters

NASA Technical Reports Server (NTRS)

Barker, Timothy

1996-01-01

Accelerator grid sputter erosion resulting from charge-exchange-ion impingement is considered to be a primary cause of failure for electrostatic ion thrusters. An experimental method was developed and implemented to measure erosion characteristics of ion-thruster accel-grids for two-grid systems as a function of beam current, accel-grid potential, and facility background pressure. Intricate accelerator grid erosion patterns, that are typically produced in a short time (a few hours), are shown. Accelerator grid volumetric and depth-erosion rates are calculated from these erosion patterns and reported for each of the parameters investigated. A simple theoretical volumetric erosion model yields results that are compared to experimental findings. Results from the model and experiments agree to within 10%, thereby verifying the testing technique. In general, the local distribution of erosion is concentrated in pits between three adjacent holes and trenches that join pits. The shapes of the pits and trenches are shown to be dependent upon operating conditions. Increases in beam current and the accel-grid voltage magnitude lead to deeper pits and trenches. Competing effects cause complex changes in depth-erosion rates as background pressure is increased. Shape factors that describe pits and trenches (i.e. ratio of the average erosion width to the maximum possible width) are also affected in relatively complex ways by changes in beam current, ac tel-grid voltage magnitude, and background pressure. In all cases, however, gross volumetric erosion rates agree with theoretical predictions.

On the uncertainty in single molecule fluorescent lifetime and energy emission measurements

NASA Technical Reports Server (NTRS)

Brown, Emery N.; Zhang, Zhenhua; Mccollom, Alex D.

1995-01-01

Time-correlated single photon counting has recently been combined with mode-locked picosecond pulsed excitation to measure the fluorescent lifetimes and energy emissions of single molecules in a flow stream. Maximum likelihood (ML) and least square methods agree and are optimal when the number of detected photons is large however, in single molecule fluorescence experiments the number of detected photons can be less than 20, 67% of those can be noise and the detection time is restricted to 10 nanoseconds. Under the assumption that the photon signal and background noise are two independent inhomogeneous poisson processes, we derive the exact joint arrival time probably density of the photons collected in a single counting experiment performed in the presence of background noise. The model obviates the need to bin experimental data for analysis, and makes it possible to analyze formally the effect of background noise on the photon detection experiment using both ML or Bayesian methods. For both methods we derive the joint and marginal probability densities of the fluorescent lifetime and fluorescent emission. the ML and Bayesian methods are compared in an analysis of simulated single molecule fluorescence experiments of Rhodamine 110 using different combinations of expected background nose and expected fluorescence emission. While both the ML or Bayesian procedures perform well for analyzing fluorescence emissions, the Bayesian methods provide more realistic measures of uncertainty in the fluorescent lifetimes. The Bayesian methods would be especially useful for measuring uncertainty in fluorescent lifetime estimates in current single molecule flow stream experiments where the expected fluorescence emission is low. Both the ML and Bayesian algorithms can be automated for applications in molecular biology.

On the Uncertainty in Single Molecule Fluorescent Lifetime and Energy Emission Measurements

NASA Technical Reports Server (NTRS)

Brown, Emery N.; Zhang, Zhenhua; McCollom, Alex D.

1996-01-01

Time-correlated single photon counting has recently been combined with mode-locked picosecond pulsed excitation to measure the fluorescent lifetimes and energy emissions of single molecules in a flow stream. Maximum likelihood (ML) and least squares methods agree and are optimal when the number of detected photons is large, however, in single molecule fluorescence experiments the number of detected photons can be less than 20, 67 percent of those can be noise, and the detection time is restricted to 10 nanoseconds. Under the assumption that the photon signal and background noise are two independent inhomogeneous Poisson processes, we derive the exact joint arrival time probability density of the photons collected in a single counting experiment performed in the presence of background noise. The model obviates the need to bin experimental data for analysis, and makes it possible to analyze formally the effect of background noise on the photon detection experiment using both ML or Bayesian methods. For both methods we derive the joint and marginal probability densities of the fluorescent lifetime and fluorescent emission. The ML and Bayesian methods are compared in an analysis of simulated single molecule fluorescence experiments of Rhodamine 110 using different combinations of expected background noise and expected fluorescence emission. While both the ML or Bayesian procedures perform well for analyzing fluorescence emissions, the Bayesian methods provide more realistic measures of uncertainty in the fluorescent lifetimes. The Bayesian methods would be especially useful for measuring uncertainty in fluorescent lifetime estimates in current single molecule flow stream experiments where the expected fluorescence emission is low. Both the ML and Bayesian algorithms can be automated for applications in molecular biology.

Current-limited electron beam injection

NASA Technical Reports Server (NTRS)

Stenzel, R. L.

1977-01-01

The injection of an electron beam into a weakly collisional, magnetized background plasma was investigated experimentally. The injected beam was energetic and cold, the background plasma was initially isothermal. Beam and plasma dimensions were so large that the system was considered unbounded. The temporal and spatial evolution of the beam-plasma system was dominated by collective effects. High-frequency electrostatic instabilities rapidly thermalized the beam and heated the background electrons. The injected beam current was balanced by a return current consisting of background electrons drifting toward the beam source. The drift between electrons and ions gave rise to an ion acoustic instability which developed into strong three-dimensional turbulence. It was shown that the injected beam current was limited by the return current which is approximately given by the electron saturation current. Non-Maxwellian electron distribution functions were observed.

Capacity of People with Intellectual Disabilities to Consent to Take Part in a Research Study

ERIC Educational Resources Information Center

Dye, Linda; Hare, Dougal Julian; Hendy, Steve

2007-01-01

Background: Within the context of current legislation relating to mental capacity in adults, the capacity of people with intellectual disabilities to consent to take part in research studies and the impact of different forms of information provision was experimentally investigated. Materials and methods: A questionnaire measure of ability to…

The Situated Dynamics of Purposes of Engagement and Self-Regulation Strategies: A Mixed-Methods Case Study of Writing

ERIC Educational Resources Information Center

Kaplan, Avi; Lichtinger, Einat; Margulis, Michal

2011-01-01

Background: Common conceptions of motivation and self-regulation view them as related but distinct entities. Most research on motivation and self-regulation investigates quantitative relations between level (e.g., self-efficacy) or type of motivation (e.g., mastery goals) and level of self-regulation. Purpose: Alternatively, the current study…

Development and Validation of a Modified Multiple Errands Test for Adults with Intellectual Disabilities

ERIC Educational Resources Information Center

Steverson, Tom; Adlam, Anna-Lynne R.; Langdon, Peter E.

2017-01-01

Background: The aims of the current study were to adapt a version of the MET for people with intellectual disabilities and assess its ecological and construct validity. Material and Methods: Using a correlational design, 40 participants with intellectual disabilities were invited to complete a battery of neuropsychological assessments and the…

Simultaneous detection of changes in protein expression and oxidative modification as function of age and APOE genotype in human APOE-targeted replacement mice

EPA Science Inventory

Background The purpose of this study was to improve the current method for detecting differentially-oxidized (carbonyl-modified) proteins by 2D-DIGE, while at the same time determining changes in total protein expression. Protein oxidation is a widely accepted model of aging and...

Frequency of Guns in the Households of High School Seniors

ERIC Educational Resources Information Center

Coker, Ann L.; Bush, Heather M.; Follingstad, Diane R.; Brancato, Candace J.

2017-01-01

Background: In 2013, President Obama lifted the federal ban on gun violence research. The current study provides one of the first reports to estimate household gun ownership as reported by youth. Methods: In this cohort study of 3,006 high school seniors from 24 schools, we examined the frequency of household guns ownership. Results: About 65%…

Stunting in Children (0-59 Months): What Is the Current Trend in South Africa?

ERIC Educational Resources Information Center

Dukhi, Natisha; Sartorius, Benn; Taylor, Myra

2017-01-01

Background: Stunting continues to affect young children as a global nutritional disorder. The aim of our study was to assess the prevalence, associated risk factors and spatial clustering for stunting in a disadvantaged South African District. Methods: A community-based cross-sectional weighted survey of households was conducted in the iLembe…

The Contextual Effect of School Satisfaction on Health-Risk Behaviors in Japanese High School Students

ERIC Educational Resources Information Center

Takakura, Minoru; Wake, Norie; Kobayashi, Minoru

2010-01-01

Background: The importance of school contextual effects on health and well-being among young people is currently recognized. This study examines the contextual effects of school satisfaction as well as the effects of individual-level school satisfaction on health-risk behaviors in Japanese high school students. Methods: Self-administered…

Consumer Evaluation of Educational Programs: Using Questionnaires Completed by Alumni.

ERIC Educational Resources Information Center

Copeland, H. L.; Hewson, M.; Weiker, G.

This paper describes a method used to evaluate 48 medical residency programs at one institution. It presents the background rationale, logistics, and results obtained by surveying alumni, in the context of their current practice, for relevant data on the value of their training experience. Surveys were sent for 3 years to all alumni of Cleveland…

Assessing Effectiveness of Students Taking a Right Stand (STARS) Nashville Student Assistance Programs

ERIC Educational Resources Information Center

Kanu, Mohamed; Hepler, Nancy; Labi, Halima

2015-01-01

Background: Since 1984, Students Taking a Right Stand (STARS) Nashville has implemented Student Assistance Programs (SAPs) in the middle Tennessee area, to include 14 counties and 16 school districts. STARS Nashville serves K-12 with a focus in middle and high schools. Methods: The current study reviewed studies that utilized quasi-experimental…

The Efficacy of Early Language Intervention in Mainstream School Settings: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Fricke, Silke; Burgoyne, Kelly; Bowyer-Crane, Claudine; Kyriacou, Maria; Zosimidou, Alexandra; Maxwell, Liam; Lervåg, Arne; Snowling, Margaret J.; Hulme, Charles

2017-01-01

Background: Oral language skills are a critical foundation for literacy and more generally for educational success. The current study shows that oral language skills can be improved by providing suitable additional help to children with language difficulties in the early stages of formal education. Methods: We conducted a randomized controlled…

Including Children with Intellectual Disabilities/Special Educational Needs into National Child Health Surveys: A Pilot Study

ERIC Educational Resources Information Center

Scott, Judith; Wishart, Jennifer; Currie, Candace

2011-01-01

Background: The language, format and length of typical national health survey questionnaires may make them inaccessible to many school-aged children with an intellectual disability. Materials and Methods: Using the standard delivery protocol, the WHO Health Behaviour in School-aged Children (HBSC) Questionnaire, currently in use in 43 countries,…

Changes in Speech Production in an Early Deafened Adult with a Cochlear Implant

ERIC Educational Resources Information Center

Wong, Patrick C. M.

2007-01-01

Background and Aims: The current study is a first investigation reporting the speech production characteristics of an early deafened adult cochlear implant user after a course of speech-language treatment. Methods and Procedures: The participant is culturally deaf and received the cochlear implant when she was 43 years old. A 24-week ABCABC…

The Nature of Trauma Memories in Acute Stress Disorder in Children and Adolescents

ERIC Educational Resources Information Center

Salmond, C. H.; Meiser-Stedman, R.; Glucksman, E.; Thompson, P.; Dalgleish, T.; Smith, P.

2011-01-01

Background: There is increasing theoretical, clinical and research evidence for the role of trauma memory in the aetiology of acute pathological stress responses in adults. However, research into the phenomenology of trauma memories in young people is currently scarce. Methods: This study compared the nature of trauma narratives to narratives of…

One Size (Never) Fits All: Segment Differences Observed Following a School-Based Alcohol Social Marketing Program

ERIC Educational Resources Information Center

Dietrich, Timo; Rundle-Thiele, Sharyn; Leo, Cheryl; Connor, Jason

2015-01-01

Background: According to commercial marketing theory, a market orientation leads to improved performance. Drawing on the social marketing principles of segmentation and audience research, the current study seeks to identify segments to examine responses to a school-based alcohol social marketing program. Methods: A sample of 371 year 10 students…

An optimized method for measuring methylmalonic acid in low volumes of serum using UPLC-MS/MS

USDA-ARS?s Scientific Manuscript database

Background: Methylmalonic acid (MMA) is a metabolic intermediate which is transformed to succinic acid (SA) by a vitamin B12-dependent catalytic step. MMA is broadly used as a clinical biomarker of functional vitamin B12 status. However, currently validated protocols use between 100 -1000 µL of se...

Practitioner Review: Do Performance-Based Measures and Ratings of Executive Function Assess the Same Construct?

ERIC Educational Resources Information Center

Toplak, Maggie E.; West, Richard F.; Stanovich, Keith E.

2013-01-01

Background: Both performance-based and rating measures are commonly used to index executive function in clinical and neuropsychological assessments. They are intended to index the same broad underlying mental construct of executive function. The association between these two types of measures was investigated in the current article. Method and…

A Preliminary Investigation of the Suitability of Aquatics for People with Severe and Profound Intellectual Disabilities

ERIC Educational Resources Information Center

Aherne, Cian; Coughlan, Barry

2017-01-01

Background: Aquatics is an under-researched but possibly appropriate form of activity for people with severe to profound intellectual disabilities (SPIDs). Aim: The current pilot study investigates the suitability of an aquatics programme for service users with SPIDs. Method: Four service users with SPID completed an 8-12-session aquatics…

A Masculine Perspective of Gendered Topics in the Research Literature on Males and Females with Intellectual Disability

ERIC Educational Resources Information Center

Wilson, Nathan J.; Parmenter, Trevor R.; Stancliffe, Roger J.; Shuttleworth, Russell P.; Parker, Desrae

2010-01-01

Background: A focus on male social pathologies may have evolved within parts of the intellectual disability research literature. This article explores this notion and makes some connections between mainstream gender theory about hegemonic masculinity and the current gendered discourse in intellectual disability research. Method: We conducted a…

Desegregating California Schools. California Current Review of Human Resources, Number 3, November 1969.

ERIC Educational Resources Information Center

California League of Women Voters, San Francisco.

This bulletin, prepared by the League of Women Voters, attempts to summarize popularly used methods of desegregation and to make specific suggestions for use in the State of California. State responsibilities for desegregation are presented against the background of Federal and State court decisions. The status of racial imbalance in California…

Staff Attitudes towards Sexuality in Relation to Gender of People with Intellectual Disability: A Qualitative Study

ERIC Educational Resources Information Center

Young, Rhea; Gore, Nick; McCarthy, Michelle

2012-01-01

Background: Research has found staff attitudes regarding the sexuality of people with intellectual disability (ID) to be negative but influenced by several factors. The current study aimed to examine whether gender of people with ID affects such attitudes. Method: Semistructured interviews were completed with 10 staff members and analysed using…

A Descriptive Profile of Physical Education Teachers and Programs in Atlantic Canada

ERIC Educational Resources Information Center

Randall, Lynn; Robinson, Daniel Bruce; Fletcher, Tim

2014-01-01

The purpose of this research was to investigate the extent to which quality physical education is currently being taught in Atlantic Canada. We used survey methods to generate descriptive data indicating: (a) the backgrounds of those who teach physical education and (b) what is being taught in physical education. Our findings suggest physical…

Responses to Positive Results from Suspicionless Random Drug Tests in US Public School Districts

ERIC Educational Resources Information Center

Ringwalt, Chris; Vincus, Amy A.; Ennett, Susan T.; Hanley, Sean; Bowling, J. Michael; Yacoubian, George S., Jr.; Rohrbach, Louise A.

2009-01-01

Background: Little is known about the context in which school-based suspicionless random drug testing (SRDT) occurs. The primary purpose of the current study was to describe school districts' responses to students' first positive result in districts with SRDT programs. Methods: Data were collected in spring 2005 from 1612 drug prevention…

Striking the Right Balance: Police Experience, Perceptions and Use of Independent Support Persons during Interviews Involving People with Intellectual Disability

ERIC Educational Resources Information Center

Henshaw, Marie; Spivak, Benjamin; Thomas, Stuart D. M.

2018-01-01

Background: Several jurisdictions mandate the presence of an independent support person during police interviews with vulnerable people. The current study investigated police officers' experiences and perceptions of these volunteers during interviews with people with intellectual disability(ies) (ID). Methods: The sample comprised 229 police…

Informal Social Networks of People with Profound Intellectual and Multiple Disabilities: Relationship with Age, Communicative Abilities and Current Living Arrangements

ERIC Educational Resources Information Center

Kamstra, A.; van der Putten, A. A. J.; Post, W. J.; Vlaskamp, C.

2015-01-01

Background: People with profound intellectual and multiple disabilities (PIMD) have limited informal social contacts. Research to determine the factors which can positively influence establishing sound informal social contacts is required. Materials and Methods: Regression analysis for 200 people with PIMD was used to analyse how age,…

A Multiple Case Study of Verbal Short-Term Memory in Velo-Cardio-Facial Syndrome

ERIC Educational Resources Information Center

Majerus, S.; Glaser, B.; Van der Linden, M.; Eliez, S.

2006-01-01

Background: Velo-cardio-facial syndrome (VCFS, 22q 11.2 deletion) is characterized by severely delayed language development. The current study explored the integrity of verbal short-term memory (STM), a cognitive function critically involved in language development, in eight children with VCFS. Methods: Using a multiple case study design, we…

Experiences of Two Multidisciplinary Team Members of Systemic Consultations in a Community Learning Disability Service

ERIC Educational Resources Information Center

Johnson, Clair; Viljoen, Nina

2017-01-01

Background: Systemic approaches can be useful in working with people with learning disabilities and their network. The evidence base for these approaches within the field of learning disabilities, however, is currently limited. Materials and Methods: This article presents part of a service evaluation of systemic consultations in a Community…

Job Satisfaction, Quality of Work Life and Work Motivation in Employees with Intellectual Disability: A Systematic Review

ERIC Educational Resources Information Center

Kocman, Andreas; Weber, Germain

2018-01-01

Background: Current research on employment options for people with Intellectual Disability emphasizes the importance of employee needs and satisfaction. The study aims at systematically reviewing the literature on job satisfaction and related constructs. Methods: A systematic literature search was conducted. Studies were included if (i) they are…

The Notional-Functional Approach: Teaching the Real Language in Its Natural Context.

ERIC Educational Resources Information Center

Laine, Elaine

This study of the notional-functional approach to second language teaching reviews the history and theoretical background of the method, current issues, and implementation of a notional-functional syllabus. Chapter 1 discusses the history and theory of the approach and the organization and advantages of the notional-functional syllabus. Chapter 2…

The Effectiveness of Antidepressant Medication in the Management of Behaviour Problems in Adults with Intellectual Disabilities: A Systematic Review

ERIC Educational Resources Information Center

Sohanpal, S. K.; Deb, S.; Thomas, C.; Soni, R.; Lenotre, L.; Unwin, G.

2007-01-01

Background: A comprehensive systematic review was performed to establish the current evidence base regarding the effectiveness of antidepressant medication for the management of behaviour problems in adults with intellectual disabilities. Method: An electronic search of PsycInfo, Embase, Medline and Cinahl databases was conducted spanning the time…

Family Sources of Sexual Health Information, Primary Messages, and Sexual Behavior of At-Risk, Urban Adolescents

ERIC Educational Resources Information Center

Rosengard, Cynthia; Tannis, Candace; Dove, David C.; van den Berg, Jacob J.; Lopez, Rosalie; Stein, L. A. R.; Morrow, Kathleen M.

2012-01-01

Background: Sources of sexual health information exert strong influence on adolescents' sexual behavior. Purpose: The current study was undertaken to understand how family serve as sexual information sources, the messages adolescents recall from family, and how family learning experiences affect sexual behavior among at-risk adolescents. Methods:…

Temperature- and field-dependent characterization of a conductor on round core cable

NASA Astrophysics Data System (ADS)

Barth, C.; van der Laan, D. C.; Bagrets, N.; Bayer, C. M.; Weiss, K.-P.; Lange, C.

2015-06-01

The conductor on round core (CORC) cable is one of the major high temperature superconductor cable concepts combining scalability, flexibility, mechanical strength, ease of fabrication and high current density; making it a possible candidate as conductor for large, high field magnets. To simulate the boundary conditions of such magnets as well as the temperature dependence of CORC cables a 1.16 m long sample consisting of 15, 4 mm wide SuperPower REBCO tapes was characterized using the ‘FBI’ (force—field—current) superconductor test facility of the Institute for Technical Physics of the Karlsruhe Institute of Technology. In a five step investigation, the CORC cable’s performance was determined at different transverse mechanical loads, magnetic background fields and temperatures as well as its response to swift current changes. In the first step, the sample’s 77 K, self-field current was measured in a liquid nitrogen bath. In the second step, the temperature dependence was measured at self-field condition and compared with extrapolated single tape data. In the third step, the magnetic background field was repeatedly cycled while measuring the current carrying capabilities to determine the impact of transverse Lorentz forces on the CORC cable sample’s performance. In the fourth step, the sample’s current carrying capabilities were measured at different background fields (2-12 T) and surface temperatures (4.2-51.5 K). Through finite element method simulations, the surface temperatures are converted into average sample temperatures and the gained field- and temperature dependence is compared with extrapolated single tape data. In the fifth step, the response of the CORC cable sample to rapid current changes (8.3 kA s-1) was observed with a fast data acquisition system. During these tests, the sample performance remains constant, no degradation is observed. The sample’s measured current carrying capabilities correlate to those of single tapes assuming field- and temperature dependence as published by the manufacturer.

Method for technology-delivered healthcare measures.

PubMed

Kramer-Jackman, Kelli Lee; Popkess-Vawter, Sue

2011-12-01

Current healthcare literature lacks development and evaluation methods for research and practice measures administered by technology. Researchers with varying levels of informatics experience are developing technology-delivered measures because of the numerous advantages they offer. Hasty development of technology-delivered measures can present issues that negatively influence administration and psychometric properties. The Method for Technology-delivered Healthcare Measures is designed to systematically guide the development and evaluation of technology-delivered measures. The five-step Method for Technology-delivered Healthcare Measures includes establishment of content, e-Health literacy, technology delivery, expert usability, and participant usability. Background information and Method for Technology-delivered Healthcare Measures steps are detailed.

Sonochemical approaches to enhanced oil recovery.

PubMed

Abramov, Vladimir O; Abramova, Anna V; Bayazitov, Vadim M; Altunina, Lyubov K; Gerasin, Artyom S; Pashin, Dmitriy M; Mason, Timothy J

2015-07-01

Oil production from wells reduces with time and the well becomes uneconomic unless enhanced oil recovery (EOR) methods are applied. There are a number of methods currently available and each has specific advantages and disadvantages depending on conditions. Currently there is a big demand for new or improved technologies in this field, the hope is that these might also be applicable to wells which have already been the subject of EOR. The sonochemical method of EOR is one of the most promising methods and is important in that it can also be applied for the treatment of horizontal wells. The present article reports the theoretical background of the developed sonochemical technology for EOR in horizontal wells; describes the requirements to the equipment needed to embody the technology. The results of the first field tests of the technology are reported. Copyright © 2014 Elsevier B.V. All rights reserved.

What is the lifetime risk of developing cancer?: the effect of adjusting for multiple primaries

PubMed Central

Sasieni, P D; Shelton, J; Ormiston-Smith, N; Thomson, C S; Silcocks, P B

2011-01-01

Background: The ‘lifetime risk' of cancer is generally estimated by combining current incidence rates with current all-cause mortality (‘current probability' method) rather than by describing the experience of a birth cohort. As individuals may get more than one type of cancer, what is generally estimated is the average (mean) number of cancers over a lifetime. This is not the same as the probability of getting cancer. Methods: We describe a method for estimating lifetime risk that corrects for the inclusion of multiple primary cancers in the incidence rates routinely published by cancer registries. The new method applies cancer incidence rates to the estimated probability of being alive without a previous cancer. The new method is illustrated using data from the Scottish Cancer Registry and is compared with ‘gold-standard' estimates that use (unpublished) data on first primaries. Results: The effect of this correction is to make the estimated ‘lifetime risk' smaller. The new estimates are extremely similar to those obtained using incidence based on first primaries. The usual ‘current probability' method considerably overestimates the lifetime risk of all cancers combined, although the correction for any single cancer site is minimal. Conclusion: Estimation of the lifetime risk of cancer should either be based on first primaries or should use the new method. PMID:21772332

Hadron electric polarizability from lattice QCD

NASA Astrophysics Data System (ADS)

Alexandru, Andrei

2017-09-01

Electromagnetic polarizabilities are important parameters for hadron structure, describing the response of the charge and current distributions inside the hadron to an external electromagnetic field. For most hadrons these quantities are poorly constrained experimentally since they can only be measured indirectly. Lattice QCD can be used to compute these quantities directly in terms of quark and gluons degrees of freedom, using the background field method. We present results for the neutron electric polarizability for two different quark masses, light enough to connect to chiral perturbation theory. These are currently the lightest quark masses used in polarizability studies. For each pion mass we compute the polarizability at four different volumes and perform an infinite volume extrapolation. We also discuss the effect of turning on the coupling between the background field and the sea quarks. A.A. is supported in part by the National Science Foundation CAREER Grant PHY-1151648 and by U.S. DOE Grant No. DE-FG02-95ER40907.

Learning to predict where human gaze is using quaternion DCT based regional saliency detection

NASA Astrophysics Data System (ADS)

Li, Ting; Xu, Yi; Zhang, Chongyang

2014-09-01

Many current visual attention approaches used semantic features to accurately capture human gaze. However, these approaches demand high computational cost and can hardly be applied to daily use. Recently, some quaternion-based saliency detection models, such as PQFT (phase spectrum of Quaternion Fourier Transform), QDCT (Quaternion Discrete Cosine Transform), have been proposed to meet real-time requirement of human gaze tracking tasks. However, current saliency detection methods used global PQFT and QDCT to locate jump edges of the input, which can hardly detect the object boundaries accurately. To address the problem, we improved QDCT-based saliency detection model by introducing superpixel-wised regional saliency detection mechanism. The local smoothness of saliency value distribution is emphasized to distinguish noises of background from salient regions. Our algorithm called saliency confidence can distinguish the patches belonging to the salient object and those of the background. It decides whether the image patches belong to the same region. When an image patch belongs to a region consisting of other salient patches, this patch should be salient as well. Therefore, we use saliency confidence map to get background weight and foreground weight to do the optimization on saliency map obtained by QDCT. The optimization is accomplished by least square method. The optimization approach we proposed unifies local and global saliency by combination of QDCT and measuring the similarity between each image superpixel. We evaluate our model on four commonly-used datasets (Toronto, MIT, OSIE and ASD) using standard precision-recall curves (PR curves), the mean absolute error (MAE) and area under curve (AUC) measures. In comparison with most state-of-art models, our approach can achieve higher consistency with human perception without training. It can get accurate human gaze even in cluttered background. Furthermore, it achieves better compromise between speed and accuracy.

Detection of artifacts from high energy bursts in neonatal EEG.

PubMed

Bhattacharyya, Sourya; Biswas, Arunava; Mukherjee, Jayanta; Majumdar, Arun Kumar; Majumdar, Bandana; Mukherjee, Suchandra; Singh, Arun Kumar

2013-11-01

Detection of non-cerebral activities or artifacts, intermixed within the background EEG, is essential to discard them from subsequent pattern analysis. The problem is much harder in neonatal EEG, where the background EEG contains spikes, waves, and rapid fluctuations in amplitude and frequency. Existing artifact detection methods are mostly limited to detect only a subset of artifacts such as ocular, muscle or power line artifacts. Few methods integrate different modules, each for detection of one specific category of artifact. Furthermore, most of the reference approaches are implemented and tested on adult EEG recordings. Direct application of those methods on neonatal EEG causes performance deterioration, due to greater pattern variation and inherent complexity. A method for detection of a wide range of artifact categories in neonatal EEG is thus required. At the same time, the method should be specific enough to preserve the background EEG information. The current study describes a feature based classification approach to detect both repetitive (generated from ECG, EMG, pulse, respiration, etc.) and transient (generated from eye blinking, eye movement, patient movement, etc.) artifacts. It focuses on artifact detection within high energy burst patterns, instead of detecting artifacts within the complete background EEG with wide pattern variation. The objective is to find true burst patterns, which can later be used to identify the Burst-Suppression (BS) pattern, which is commonly observed during newborn seizure. Such selective artifact detection is proven to be more sensitive to artifacts and specific to bursts, compared to the existing artifact detection approaches applied on the complete background EEG. Several time domain, frequency domain, statistical features, and features generated by wavelet decomposition are analyzed to model the proposed bi-classification between burst and artifact segments. A feature selection method is also applied to select the feature subset producing highest classification accuracy. The suggested feature based classification method is executed using our recorded neonatal EEG dataset, consisting of burst and artifact segments. We obtain 78% sensitivity and 72% specificity as the accuracy measures. The accuracy obtained using the proposed method is found to be about 20% higher than that of the reference approaches. Joint use of the proposed method with our previous work on burst detection outperforms reference methods on simultaneous burst and artifact detection. As the proposed method supports detection of a wide range of artifact patterns, it can be improved to incorporate the detection of artifacts within other seizure patterns and background EEG information as well. © 2013 Elsevier Ltd. All rights reserved.

A diffusion-based truncated projection artifact reduction method for iterative digital breast tomosynthesis reconstruction

PubMed Central

Lu, Yao; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir M

2014-01-01

Digital breast tomosynthesis (DBT) has strong promise to improve sensitivity for detecting breast cancer. DBT reconstruction estimates the breast tissue attenuation using projection views (PVs) acquired in a limited angular range. Because of the limited field of view (FOV) of the detector, the PVs may not completely cover the breast in the x-ray source motion direction at large projection angles. The voxels in the imaged volume cannot be updated when they are outside the FOV, thus causing a discontinuity in intensity across the FOV boundaries in the reconstructed slices, which we refer to as the truncated projection artifact (TPA). Most existing TPA reduction methods were developed for the filtered backprojection method in the context of computed tomography. In this study, we developed a new diffusion-based method to reduce TPAs during DBT reconstruction using the simultaneous algebraic reconstruction technique (SART). Our TPA reduction method compensates for the discontinuity in background intensity outside the FOV of the current PV after each PV updating in SART. The difference in voxel values across the FOV boundary is smoothly diffused to the region beyond the FOV of the current PV. Diffusion-based background intensity estimation is performed iteratively to avoid structured artifacts. The method is applicable to TPA in both the forward and backward directions of the PVs and for any number of iterations during reconstruction. The effectiveness of the new method was evaluated by comparing the visual quality of the reconstructed slices and the measured discontinuities across the TPA with and without artifact correction at various iterations. The results demonstrated that the diffusion-based intensity compensation method reduced the TPA while preserving the detailed tissue structures. The visibility of breast lesions obscured by the TPA was improved after artifact reduction. PMID:23318346

NMT - A new individual ion counting method: Comparison to a Faraday cup

NASA Astrophysics Data System (ADS)

Burton, Michael; Gorbunov, Boris

2018-03-01

Two sample detectors used to analyze the emission from Gas Chromatography (GC) columns are the Flame Ionization Detector (FID) and the Electron Capture Detector (ECD). Both of these detectors involve ionization of the sample molecules and then measuring electric current in the gas using a Faraday cup. In this paper a newly discovered method of ion counting, Nanotechnology Molecular Tagging (NMT) is tested as a replacement to the Faraday cup in GCs. In this method the effective physical volume of individual molecules is enlarged up to 1 billion times enabling them to be detected by an optical particle counter. It was found that the sensitivity of NMT was considerably greater than the Faraday cup. The background in the NMT was circa 200 ions per cm3, corresponding to an extremely low electric current ∼10-17 A.

Implementation of a flow-dependent background error correlation length scale formulation in the NEMOVAR OSTIA system

NASA Astrophysics Data System (ADS)

Fiedler, Emma; Mao, Chongyuan; Good, Simon; Waters, Jennifer; Martin, Matthew

2017-04-01

OSTIA is the Met Office's Operational Sea Surface Temperature (SST) and Ice Analysis system, which produces L4 (globally complete, gridded) analyses on a daily basis. Work is currently being undertaken to replace the original OI (Optimal Interpolation) data assimilation scheme with NEMOVAR, a 3D-Var data assimilation method developed for use with the NEMO ocean model. A dual background error correlation length scale formulation is used for SST in OSTIA, as implemented in NEMOVAR. Short and long length scales are combined according to the ratio of the decomposition of the background error variances into short and long spatial correlations. The pre-defined background error variances vary spatially and seasonally, but not on shorter time-scales. If the derived length scales applied to the daily analysis are too long, SST features may be smoothed out. Therefore a flow-dependent component to determining the effective length scale has also been developed. The total horizontal gradient of the background SST field is used to identify regions where the length scale should be shortened. These methods together have led to an improvement in the resolution of SST features compared to the previous OI analysis system, without the introduction of spurious noise. This presentation will show validation results for feature resolution in OSTIA using the OI scheme, the dual length scale NEMOVAR scheme, and the flow-dependent implementation.

Prediction of Anxiety Symptoms in Preschool-Aged Children: Examination of Maternal and Paternal Perspectives

ERIC Educational Resources Information Center

Edwards, Susan L.; Rapee, Ronald M.; Kennedy, Susan

2010-01-01

Background: Little is known about risk factors for anxiety in young children. The current study investigated the value of a set of theoretically derived risk factors to predict symptoms of anxiety in a sample of preschool-aged children. Methods: Mothers (n = 632) and fathers (n = 249) completed questionnaires twice, 12 months apart. Measures were…

School-Based Sleep Education Programs for Short Sleep Duration in Adolescents: A Systematic Review and Meta-Analysis

ERIC Educational Resources Information Center

Chung, Ka-Fai; Chan, Man-Sum; Lam, Ying-Yin; Lai, Cindy Sin-Yee; Yeung, Wing-Fai

2017-01-01

Background: Insufficient sleep among students is a major school health problem. School-based sleep education programs tailored to reach large number of students may be one of the solutions. A systematic review and meta-analysis was conducted to summarize the programs' effectiveness and current status. Methods: Electronic databases were searched up…

Association of School Social Networks' Influence and Mass Media Factors with Cigarette Smoking among Asthmatic Students

ERIC Educational Resources Information Center

Kanamori, Mariano; Beck, Kenneth H.; Carter-Pokras, Olivia

2015-01-01

Background: Around 10% of adolescent students under 18 years have current asthma. Asthmatic adolescents smoke as much or more than non-asthmatic adolescents. We explored the association between exposure to mass media and social networks' influence with asthmatic student smoking, and variations of these exposures by sex. Methods: This study…

Exploring the Literature on Music Participation and Social Connectedness for Young People with Intellectual Disability: A Critical Interpretive Synthesis

ERIC Educational Resources Information Center

Murphy, Melissa A. I.; McFerran, Katrina

2017-01-01

Background: This article explores the literature on social connectedness and music for young people with disability. It then critically examines the level of congruence between the reported literature to date and current rights-based disability studies discourse. Method: A critical interpretive synthesis was used to examine 27 articles referencing…

Transitions from School for Young Adults with Intellectual Disability: Parental Perspectives on "Life as an Adjustment"

ERIC Educational Resources Information Center

Davies, Michael D.; Beamish, Wendi

2009-01-01

Background: Few studies have investigated transition programs and outcomes for young adults with disabilities as viewed from the parent perspective. The current Australian study provided a voice for parents to report on the experiences of and outcomes for young adults following their recent transition from school into post-school life. Method: A…

The Effect of Reminiscence Group Work on Life Satisfaction, Self-Esteem and Mood of Ageing People with Intellectual Disabilities

ERIC Educational Resources Information Center

Van Puyenbroeck, Joris; Maes, Bea

2009-01-01

Background: This study evaluates the effects of reminiscence group work on the subjective well-being of ageing people with intellectual disabilities. Methods: The content of the successive group work sessions was manipulated as follows: a control-phase with three "current topics" sessions, an experimental phase with six "reminiscence" sessions and…

Barriers and Enablers to Accessing Mental Health Services for People with Intellectual Disability: A Scoping Review

ERIC Educational Resources Information Center

Whittle, Erin Louise; Fisher, Karen R.; Reppermund, Simone; Lenroot, Rhoshel; Trollor, Julian

2018-01-01

Background: It is well established that people with an intellectual disability have high rates of mental health problems, yet rates of uptake of services do not match need. Aim: To identify the current literature pertaining to the barriers and facilitators to access to mental health services for people with an intellectual disability. Method: A…

An Exploration of Clinical Psychology's Response to Parental Bereavement in Adults with Intellectual Disability

ERIC Educational Resources Information Center

Irwin, Lynn; O'Malley, Grace; Neelofur, Shazia; Guerin, Suzanne

2017-01-01

Background: The dearth of literature regarding how or when to intervene when an adult with intellectual disability is bereaved may impede clinical practice; this study therefore aimed to explore the current clinical psychology response, so as to enhance understanding of the role of the profession in supporting grief within this population. Method:…

Paid Support Workers for Adults with Intellectual Disabilities; Their Current Knowledge of Hearing Loss and Future Training Needs

ERIC Educational Resources Information Center

McShea, Lynzee; Fulton, John; Hayes, Catherine

2016-01-01

Background: People with intellectual disabilities are more likely to have hearing loss than the general population. For those unable to self-advocate, the responsibility of detection and management falls to their caregivers. Methods: This is the first cycle of a project using action research methodology to improve services. Twenty care workers…

A Review of the Research: Common Core State Standards for Improving Rural Children's School Readiness

ERIC Educational Resources Information Center

Bailey, Lora Battle

2014-01-01

Although a plethora of research focuses on economically at-risk preschool children in general across the United States, little can be found that investigates methods for improving rural children's academic outcomes. This review of research is intended to provide a contextual understanding of the background and current conditions that exist…

The Meaning of "Choice and Control" for People with Intellectual Disabilities Who Are Planning Their Social Care and Support

ERIC Educational Resources Information Center

Williams, Val; Porter, Sue

2017-01-01

Background: This paper questions consumerist assumptions in current English social care policy and aims to look behind the processes of personalization to interrogate what "choice and control" means in the lives of a diverse group of people with intellectual disabilities. Methods: Data were from multiple interviews and direct practice…

Long-Term Outcome from a Medium Secure Service for People with Intellectual Disability

ERIC Educational Resources Information Center

Alexander, R. T.; Crouch, K.; Halstead, S.; Piachaud, J.

2006-01-01

Background: The purpose of this paper is to describe long-term outcomes for patients discharged over a 12-year period from a medium secure service for people with intellectual disabilities (ID). Methods: A cohort study using case-notes analysis and a structured interview of current key informants. Results: Eleven per cent of the sample was…

What Is Standard Care for People with Learning Disabilities and Behaviour That Challenges and What Does It Cost?

ERIC Educational Resources Information Center

Iemmi, Valentina; Knapp, Martin; Gore, Nick; Cooper, Vivien; Brown, Freddy Jackson; Reid, Caroline; Saville, Maria

2016-01-01

Background: We describe current care arrangements in England for children, young people and adults with learning disabilities and behaviour that challenges, and estimate their comparative costs. Materials and Methods: A two-round Delphi exercise was performed in March and April 2014, followed by a costing exercise. Results: The study finds a mixed…

Psychological Well-Being in Parents of Children with Angelman, Cornelia de Lange and Cri du Chat Syndromes

ERIC Educational Resources Information Center

Griffith, G. M.; Hastings, R. P.; Oliver, C.; Howlin, P.; Moss, J.; Petty, J.; Tunnicliffe, P.

2011-01-01

Background: The current study focuses on mothers and fathers of children with three rare genetic syndromes that are relatively unexplored in terms of family experience: Angelman syndrome, Cornelia de Lange syndrome and Cri du Chat syndrome. Method: Parents of children with Angelman syndrome (n = 15), Cornelia de Lange syndrome (n = 16) and Cri du…

Predicting Reading Comprehension Academic Achievement in Late Adolescents with Velo-Cardio-Facial (22q11.2 Deletion) Syndrome (VCFS): A Longitudinal Study

ERIC Educational Resources Information Center

Antshel, K.; Hier, B.; Fremont, W.; Faraone, S. V.; Kates, W.

2014-01-01

Background: The primary objective of the current study was to examine the childhood predictors of adolescent reading comprehension in velo-cardio-facial syndrome (VCFS). Although much research has focused on mathematics skills among individuals with VCFS, no studies have examined predictors of reading comprehension. Methods: 69 late adolescents…

Respiratory and Laryngeal Changes with Vocal Loading in Younger and Older Individuals

ERIC Educational Resources Information Center

Sundarrajan, Anusha; Huber, Jessica E.; Sivasankar, M. Preeti

2017-01-01

Purpose: The objective of the current study was to investigate the effects of age and vocal loading on the respiratory and laryngeal systems. Method: Fourteen younger (M = 20 years) and 13 older (M = 75 years) healthy individuals participated in a 40-min vocal loading challenge in the presence of 70-dB background noise. Respiratory kinematic and…

Finding the Balance between Process and Product through Perceptual Lesson Planning

ERIC Educational Resources Information Center

Uhrmacher, P. Bruce; Conrad, Bradley M.; Moroye, Christy M.

2013-01-01

Background/Context: Lesson planning is one of the most common activities required of teachers; however, since the late 1970s and early 1980s, it has not been a major focus of study, either conceptually or empirically. Although there are recent articles on the topic, much of the current work is specific to examining a particular teaching method or…

Employment in Adults with Down Syndrome in the United States: Results from a National Survey

ERIC Educational Resources Information Center

Kumin, Libby; Schoenbrodt, Lisa

2016-01-01

Background: There is no current data about employment/unemployment of adults with Down syndrome in the United States. The data that exists includes adults with Down syndrome as part of the larger group of people with disabilities or people with intellectual disability. Method: This study used a survey to investigate paid and volunteer employment,…

Co-Occurrence of Conduct Disorder and Depression in a Clinic-Based Sample of Boys with ADHD

ERIC Educational Resources Information Center

Drabick, Deborah A. G.; Gadow, Kenneth D.; Sprafkin, Joyce

2006-01-01

Background: Children with attention-deficit/hyperactivity disorder (ADHD) are at risk for the development of comorbid conduct disorder (CD) and depression. The current study examined potential psychosocial risk factors for CD and depression in a clinic-based sample of 203 boys (aged 6-10 years) with ADHD. Methods: The boys and their mothers…

Understanding Prolonged Cessation From Heroin Use: Findings From a Community-Based Sample

PubMed Central

Weiss, Linda; Gass, Jonathon; Egan, James E.; Ompad, Danielle C.; Trezza, Claudia; Vlahov, David

2014-01-01

Background There is abundant literature describing heroin initiation, co-morbidities, and treatment. Few studies focus on cessation, examining the factors that motivate and facilitate it. Methods The CHANGE study utilized mixed methods to investigate heroin cessation among low-income New York City participants. This paper describes findings from qualitative interviews with 20 former and 11 current heroin users. Interviews focused on background and current activities, supports, drug history, cessation attempts, and motivators and facilitators to cessation. Results Participants found motivation for cessation in improved quality of life; combination of treatment, strategic avoidance of triggers, and engagement in alternative activities, including support groups, exercise, and faith-based practice. Several reported that progress toward goals served as motivators that increased confidence and facilitated cessation. Ultimatums were key motivators for some participants. Beyond that, they could not articulate factors that distinguished successful from unsuccessful cessation attempts, although data suggest that those who were successful could describe more individualized and concrete—rather than general—motivators and strategies. Conclusions Our findings indicate that cessation may be facilitated by multifaceted and individualized strategies, suggesting a need for personal and comprehensive approaches to treatment. PMID:25052788

A statistical, task-based evaluation method for three-dimensional x-ray breast imaging systems using variable-background phantoms

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

Park, Subok; Jennings, Robert; Liu Haimo

Purpose: For the last few years, development and optimization of three-dimensional (3D) x-ray breast imaging systems, such as digital breast tomosynthesis (DBT) and computed tomography, have drawn much attention from the medical imaging community, either academia or industry. However, there is still much room for understanding how to best optimize and evaluate the devices over a large space of many different system parameters and geometries. Current evaluation methods, which work well for 2D systems, do not incorporate the depth information from the 3D imaging systems. Therefore, it is critical to develop a statistically sound evaluation method to investigate the usefulnessmore » of inclusion of depth and background-variability information into the assessment and optimization of the 3D systems. Methods: In this paper, we present a mathematical framework for a statistical assessment of planar and 3D x-ray breast imaging systems. Our method is based on statistical decision theory, in particular, making use of the ideal linear observer called the Hotelling observer. We also present a physical phantom that consists of spheres of different sizes and materials for producing an ensemble of randomly varying backgrounds to be imaged for a given patient class. Lastly, we demonstrate our evaluation method in comparing laboratory mammography and three-angle DBT systems for signal detection tasks using the phantom's projection data. We compare the variable phantom case to that of a phantom of the same dimensions filled with water, which we call the uniform phantom, based on the performance of the Hotelling observer as a function of signal size and intensity. Results: Detectability trends calculated using the variable and uniform phantom methods are different from each other for both mammography and DBT systems. Conclusions: Our results indicate that measuring the system's detection performance with consideration of background variability may lead to differences in system performance estimates and comparisons. For the assessment of 3D systems, to accurately determine trade offs between image quality and radiation dose, it is critical to incorporate randomness arising from the imaging chain including background variability into system performance calculations.« less

Methods for Estimating Environmental Effects and Constraints on NexGen: High Density Case Study

NASA Technical Reports Server (NTRS)

Augustine, S.; Ermatinger, C.; Graham, M.; Thompson, T.

2010-01-01

This document provides a summary of the current methods developed by Metron Aviation for the estimate of environmental effects and constraints on the Next Generation Air Transportation System (NextGen). This body of work incorporates many of the key elements necessary to achieve such an estimate. Each section contains the background and motivation for the technical elements of the work, a description of the methods used, and possible next steps. The current methods described in this document were selected in an attempt to provide a good balance between accuracy and fairly rapid turn around times to best advance Joint Planning and Development Office (JPDO) System Modeling and Analysis Division (SMAD) objectives while also supporting the needs of the JPDO Environmental Working Group (EWG). In particular this document describes methods applied to support the High Density (HD) Case Study performed during the spring of 2008. A reference day (in 2006) is modeled to describe current system capabilities while the future demand is applied to multiple alternatives to analyze system performance. The major variables in the alternatives are operational/procedural capabilities for airport, terminal, and en route airspace along with projected improvements to airframe, engine and navigational equipment.

Study of moving object detecting and tracking algorithm for video surveillance system

NASA Astrophysics Data System (ADS)

Wang, Tao; Zhang, Rongfu

2010-10-01

This paper describes a specific process of moving target detecting and tracking in the video surveillance.Obtain high-quality background is the key to achieving differential target detecting in the video surveillance.The paper is based on a block segmentation method to build clear background,and using the method of background difference to detecing moving target,after a series of treatment we can be extracted the more comprehensive object from original image,then using the smallest bounding rectangle to locate the object.In the video surveillance system, the delay of camera and other reasons lead to tracking lag,the model of Kalman filter based on template matching was proposed,using deduced and estimated capacity of Kalman,the center of smallest bounding rectangle for predictive value,predicted the position in the next moment may appare,followed by template matching in the region as the center of this position,by calculate the cross-correlation similarity of current image and reference image,can determine the best matching center.As narrowed the scope of searching,thereby reduced the searching time,so there be achieve fast-tracking.

Star sub-pixel centroid calculation based on multi-step minimum energy difference method

NASA Astrophysics Data System (ADS)

Wang, Duo; Han, YanLi; Sun, Tengfei

2013-09-01

The star's centroid plays a vital role in celestial navigation, star images which be gotten during daytime, due to the strong sky background, have a low SNR, and the star objectives are nearly submerged in the background, takes a great trouble to the centroid localization. Traditional methods, such as a moment method, weighted centroid calculation method is simple but has a big error, especially in the condition of a low SNR. Gaussian method has a high positioning accuracy, but the computational complexity. Analysis of the energy distribution in star image, a location method for star target centroids based on multi-step minimum energy difference is proposed. This method uses the linear superposition to narrow the centroid area, in the certain narrow area uses a certain number of interpolation to pixels for the pixels' segmentation, and then using the symmetry of the stellar energy distribution, tentatively to get the centroid position: assume that the current pixel is the star centroid position, and then calculates and gets the difference of the sum of the energy which in the symmetric direction(in this paper we take the two directions of transverse and longitudinal) and the equal step length(which can be decided through different conditions, the paper takes 9 as the step length) of the current pixel, and obtain the centroid position in this direction when the minimum difference appears, and so do the other directions, then the validation comparison of simulated star images, and compare with several traditional methods, experiments shows that the positioning accuracy of the method up to 0.001 pixel, has good effect to calculate the centroid of low SNR conditions; at the same time, uses this method on a star map which got at the fixed observation site during daytime in near-infrared band, compare the results of the paper's method with the position messages which were known of the star, it shows that :the multi-step minimum energy difference method achieves a better effect.

SU-F-I-43: A Software-Based Statistical Method to Compute Low Contrast Detectability in Computed Tomography Images

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

Chacko, M; Aldoohan, S

Purpose: The low contrast detectability (LCD) of a CT scanner is its ability to detect and display faint lesions. The current approach to quantify LCD is achieved using vendor-specific methods and phantoms, typically by subjectively observing the smallest size object at a contrast level above phantom background. However, this approach does not yield clinically applicable values for LCD. The current study proposes a statistical LCD metric using software tools to not only to assess scanner performance, but also to quantify the key factors affecting LCD. This approach was developed using uniform QC phantoms, and its applicability was then extended undermore » simulated clinical conditions. Methods: MATLAB software was developed to compute LCD using a uniform image of a QC phantom. For a given virtual object size, the software randomly samples the image within a selected area, and uses statistical analysis based on Student’s t-distribution to compute the LCD as the minimal Hounsfield Unit’s that can be distinguished from the background at the 95% confidence level. Its validity was assessed by comparison with the behavior of a known QC phantom under various scan protocols and a tissue-mimicking phantom. The contributions of beam quality and scattered radiation upon the computed LCD were quantified by using various external beam-hardening filters and phantom lengths. Results: As expected, the LCD was inversely related to object size under all scan conditions. The type of image reconstruction kernel filter and tissue/organ type strongly influenced the background noise characteristics and therefore, the computed LCD for the associated image. Conclusion: The proposed metric and its associated software tools are vendor-independent and can be used to analyze any LCD scanner performance. Furthermore, the method employed can be used in conjunction with the relationships established in this study between LCD and tissue type to extend these concepts to patients’ clinical CT images.« less

The Cosmic Infrared Background Experiment (CIBER): A Sounding Rocket Payload to Study the near Infrared Extragalactic Background Light

NASA Astrophysics Data System (ADS)

Zemcov, M.; Arai, T.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Tsumura, K.; Wada, T.

2013-08-01

The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): A SOUNDING ROCKET PAYLOAD TO STUDY THE NEAR INFRARED EXTRAGALACTIC BACKGROUND LIGHT

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

Zemcov, M.; Bock, J.; Hristov, V.

2013-08-15

The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, andmore » electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.« less

Component separation of a isotropic Gravitational Wave Background

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

Parida, Abhishek; Jhingan, Sanjay; Mitra, Sanjit, E-mail: abhishek@jmi.ac.in, E-mail: sanjit@iucaa.in, E-mail: sjhingan@jmi.ac.in

2016-04-01

A Gravitational Wave Background (GWB) is expected in the universe from the superposition of a large number of unresolved astrophysical sources and phenomena in the early universe. Each component of the background (e.g., from primordial metric perturbations, binary neutron stars, milli-second pulsars etc.) has its own spectral shape. Many ongoing experiments aim to probe GWB at a variety of frequency bands. In the last two decades, using data from ground-based laser interferometric gravitational wave (GW) observatories, upper limits on GWB were placed in the frequency range of 0∼ 50−100 Hz, considering one spectral shape at a time. However, one strong componentmore » can significantly enhance the estimated strength of another component. Hence, estimation of the amplitudes of the components with different spectral shapes should be done jointly. Here we propose a method for 'component separation' of a statistically isotropic background, that can, for the first time, jointly estimate the amplitudes of many components and place upper limits. The method is rather straightforward and needs negligible amount of computation. It utilises the linear relationship between the measurements and the amplitudes of the actual components, alleviating the need for a sampling based method, e.g., Markov Chain Monte Carlo (MCMC) or matched filtering, which are computationally intensive and cumbersome in a multi-dimensional parameter space. Using this formalism we could also study how many independent components can be separated using a given dataset from a network of current and upcoming ground based interferometric detectors.« less

Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

2014-01-01

The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thrusters anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization.

Dissipation function and adaptive gradient reconstruction based smoke detection in video

NASA Astrophysics Data System (ADS)

Li, Bin; Zhang, Qiang; Shi, Chunlei

2017-11-01

A method for smoke detection in video is proposed. The camera monitoring the scene is assumed to be stationary. With the atmospheric scattering model, dissipation function is reflected transmissivity between the background objects in the scene and the camera. Dark channel prior and fast bilateral filter are used for estimating dissipation function which is only the function of the depth of field. Based on dissipation function, visual background extractor (ViBe) can be used for detecting smoke as a result of smoke's motion characteristics as well as detecting other moving targets. Since smoke has semi-transparent parts, the things which are covered by these parts can be recovered by poisson equation adaptively. The similarity between the recovered parts and the original background parts in the same position is calculated by Normalized Cross Correlation (NCC) and the original background's value is selected from the frame which is nearest to the current frame. The parts with high similarity are considered as smoke parts.

Amplification due to two-stream instability of self-electric and magnetic fields of an ion beam propagating in background plasma

NASA Astrophysics Data System (ADS)

Tokluoglu, Erinc K.; Kaganovich, Igor D.; Carlsson, Johan A.; Hara, Kentaro; Startsev, Edward A.

2018-05-01

Propagation of charged particle beams in background plasma as a method of space charge neutralization has been shown to achieve a high degree of charge and current neutralization and therefore enables nearly ballistic propagation and focusing of charged particle beams. Correspondingly, the use of plasmas for propagation of charged particle beams has important applications for transport and focusing of intense particle beams in inertial fusion and high energy density laboratory plasma physics. However, the streaming of beam ions through a background plasma can lead to the development of two-stream instability between the beam ions and the plasma electrons. The beam electric and magnetic fields enhanced by the two-stream instability can lead to defocusing of the ion beam. Using particle-in-cell simulations, we study the scaling of the instability-driven self-electromagnetic fields and consequent defocusing forces with the background plasma density and beam ion mass. We identify plasma parameters where the defocusing forces can be reduced.

Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

2014-01-01

The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

A Readout Integrated Circuit (ROIC) employing self-adaptive background current compensation technique for Infrared Focal Plane Array (IRFPA)

NASA Astrophysics Data System (ADS)

Zhou, Tong; Zhao, Jian; He, Yong; Jiang, Bo; Su, Yan

2018-05-01

A novel self-adaptive background current compensation circuit applied to infrared focal plane array is proposed in this paper, which can compensate the background current generated in different conditions. Designed double-threshold detection strategy is to estimate and eliminate the background currents, which could significantly reduce the hardware overhead and improve the uniformity among different pixels. In addition, the circuit is well compatible to various categories of infrared thermo-sensitive materials. The testing results of a 4 × 4 experimental chip showed that the proposed circuit achieves high precision, wide application and high intelligence. Tape-out of the 320 × 240 readout circuit, as well as the bonding, encapsulation and imaging verification of uncooled infrared focal plane array, have also been completed.

CUORE and Background Reduction Case Studies for CUPID

NASA Astrophysics Data System (ADS)

Sakai, Michinari; Gozlukluoglu, Nihal; Huang, Huan; Cuore Collaboration

2017-09-01

CUORE (Cryogenic Underground Observatory for Rare Events) is a bolometric experiment at cryogenic temperatures currently in operation to search for neutrinoless double beta decay. Successful detection of this extremely rare process requires stringent control of radioactive backgrounds of the experiment as well as the detector itself. Great care was taken in CUORE to select the materials and various parts that comprise the current detector. However next-generation neutrinoless double beta decay experiments face a challenge to further reduce backgrounds in order to probe more deeply into the effective Majorana neutrino mass phase space. In this presentation we will review the sensitivity and background budget for the currently running experiment CUORE, as well as the target sensitivity and background goals for the next generation experiment CUPID that will cover the inverted neutrino mass hierarchy. We will explore simulation based R&D case studies for background reduction and lay out achievable background reduction levels using possible materials and feasible geometries in the context of CUPID. National Science Foundation.

The International College of Neuropsychopharmacology (CINP) Treatment Guidelines for Bipolar Disorder in Adults (CINP-BD-2017), Part 1: Background and Methods of the Development of Guidelines

PubMed Central

Young, Allan; Yatham, Lakshmi; Grunze, Heinz; Vieta, Eduard; Blier, Pierre; Moeller, Hans Jurgen; Kasper, Siegfried

2017-01-01

Abstract Background: This paper includes a short description of the important clinical aspects of Bipolar Disorder with emphasis on issues that are important for the therapeutic considerations, including mixed and psychotic features, predominant polarity, and rapid cycling as well as comorbidity. Methods: The workgroup performed a review and critical analysis of the literature concerning grading methods and methods for the development of guidelines. Results: The workgroup arrived at a consensus to base the development of the guideline on randomized controlled trials and related meta-analyses alone in order to follow a strict evidence-based approach. A critical analysis of the existing methods for the grading of treatment options was followed by the development of a new grading method to arrive at efficacy and recommendation levels after the analysis of 32 distinct scenarios of available data for a given treatment option. Conclusion: The current paper reports details on the design, method, and process for the development of CINP guidelines for the treatment of Bipolar Disorder. The rationale and the method with which all data and opinions are combined in order to produce an evidence-based operationalized but also user-friendly guideline and a specific algorithm are described in detail in this paper. PMID:27815414

Megalithic Monument of Abuli, Georgia, and Possible Astronomical Signi cance

NASA Astrophysics Data System (ADS)

Jijelava, Badri; Simonia, Irakli

2016-08-01

Background/Objectives: In recent years, in purpose of investigation of the artefacts, the ancient culture and religion, based on the astronomy knowledge play significant role. The aim of this work is to identify the orientations of the religious megalithic complexes and their correlation to the celestial luminaries. Methods/Statistical Analysis: We harmonized the archeological data, ethnographical, historical information and restoration of ancient celestial sphere (using special astronomy application), which give us possibility to identify the correlations between the acronychal or helical rising/ set of luminaries and directions of megalithic objects. Very often such connections are stored in a current folklore too. Findings: This technique of investigations give us more clear understanding of ancient universe. Using this method, we can receive latent information about the ancient Gods - Luminaries, clarify current mythology, date of the megalithic complex. Application/Improvements: This method of investigation is an additional instrument for archeological investigations,

Endpoints and cutpoints in head and neck oncology trials: methodical background, challenges, current practice and perspectives.

PubMed

Hezel, Marcus; von Usslar, Kathrin; Kurzweg, Thiemo; Lörincz, Balazs B; Knecht, Rainald

2016-04-01

This article reviews the methodical and statistical basics of designing a trial, with a special focus on the process of defining and choosing endpoints and cutpoints as the foundations of clinical research, and ultimately that of evidence-based medicine. There has been a significant progress in the treatment of head and neck cancer in the past few decades. Currently available treatment options can have a variety of different goals, depending e.g. on tumor stage, among other factors. The outcome of a specific treatment in clinical trials is measured using endpoints. Besides classical endpoints, such as overall survival or organ preservation, other endpoints like quality of life are becoming increasingly important in designing and conducting a trial. The present work is based on electronic research and focuses on the solid methodical and statistical basics of a clinical trial, on the structure of study designs and on the presentation of various endpoints.

3D temporal subtraction on multislice CT images using nonlinear warping technique

NASA Astrophysics Data System (ADS)

Ishida, Takayuki; Katsuragawa, Shigehiko; Kawashita, Ikuo; Kim, Hyounseop; Itai, Yoshinori; Awai, Kazuo; Li, Qiang; Doi, Kunio

2007-03-01

The detection of very subtle lesions and/or lesions overlapped with vessels on CT images is a time consuming and difficult task for radiologists. In this study, we have developed a 3D temporal subtraction method to enhance interval changes between previous and current multislice CT images based on a nonlinear image warping technique. Our method provides a subtraction CT image which is obtained by subtraction of a previous CT image from a current CT image. Reduction of misregistration artifacts is important in the temporal subtraction method. Therefore, our computerized method includes global and local image matching techniques for accurate registration of current and previous CT images. For global image matching, we selected the corresponding previous section image for each current section image by using 2D cross-correlation between a blurred low-resolution current CT image and a blurred previous CT image. For local image matching, we applied the 3D template matching technique with translation and rotation of volumes of interests (VOIs) which were selected in the current and the previous CT images. The local shift vector for each VOI pair was determined when the cross-correlation value became the maximum in the 3D template matching. The local shift vectors at all voxels were determined by interpolation of shift vectors of VOIs, and then the previous CT image was nonlinearly warped according to the shift vector for each voxel. Finally, the warped previous CT image was subtracted from the current CT image. The 3D temporal subtraction method was applied to 19 clinical cases. The normal background structures such as vessels, ribs, and heart were removed without large misregistration artifacts. Thus, interval changes due to lung diseases were clearly enhanced as white shadows on subtraction CT images.

Detection and correction of laser induced breakdown spectroscopy spectral background based on spline interpolation method

NASA Astrophysics Data System (ADS)

Tan, Bing; Huang, Min; Zhu, Qibing; Guo, Ya; Qin, Jianwei

2017-12-01

Laser-induced breakdown spectroscopy (LIBS) is an analytical technique that has gained increasing attention because of many applications. The production of continuous background in LIBS is inevitable because of factors associated with laser energy, gate width, time delay, and experimental environment. The continuous background significantly influences the analysis of the spectrum. Researchers have proposed several background correction methods, such as polynomial fitting, Lorenz fitting and model-free methods. However, less of them apply these methods in the field of LIBS Technology, particularly in qualitative and quantitative analyses. This study proposes a method based on spline interpolation for detecting and estimating the continuous background spectrum according to its smooth property characteristic. Experiment on the background correction simulation indicated that, the spline interpolation method acquired the largest signal-to-background ratio (SBR) over polynomial fitting, Lorenz fitting and model-free method after background correction. These background correction methods all acquire larger SBR values than that acquired before background correction (The SBR value before background correction is 10.0992, whereas the SBR values after background correction by spline interpolation, polynomial fitting, Lorentz fitting, and model-free methods are 26.9576, 24.6828, 18.9770, and 25.6273 respectively). After adding random noise with different kinds of signal-to-noise ratio to the spectrum, spline interpolation method acquires large SBR value, whereas polynomial fitting and model-free method obtain low SBR values. All of the background correction methods exhibit improved quantitative results of Cu than those acquired before background correction (The linear correlation coefficient value before background correction is 0.9776. Moreover, the linear correlation coefficient values after background correction using spline interpolation, polynomial fitting, Lorentz fitting, and model-free methods are 0.9998, 0.9915, 0.9895, and 0.9940 respectively). The proposed spline interpolation method exhibits better linear correlation and smaller error in the results of the quantitative analysis of Cu compared with polynomial fitting, Lorentz fitting and model-free methods, The simulation and quantitative experimental results show that the spline interpolation method can effectively detect and correct the continuous background.

Genomics: The Science and Technology Behind the Human Genome Project (by Charles R. Cantor and Cassandra L. Smith)

NASA Astrophysics Data System (ADS)

Serra, Reviewed By Martin J.

2000-01-01

Genomics is one of the most rapidly expanding areas of science. This book is an outgrowth of a series of lectures given by one of the former heads (CRC) of the Human Genome Initiative. The book is designed to reach a wide audience, from biologists with little chemical or physical science background through engineers, computer scientists, and physicists with little current exposure to the chemical or biological principles of genetics. The text starts with a basic review of the chemical and biological properties of DNA. However, without either a biochemistry background or a supplemental biochemistry text, this chapter and much of the rest of the text would be difficult to digest. The second chapter is designed to put DNA into the context of the larger chromosomal unit. Specialized chromosomal structures and sequences (centromeres, telomeres) are introduced, leading to a section on chromosome organization and purification. The next 4 chapters cover the physical (hybridization, electrophoresis), chemical (polymerase chain reaction), and biological (genetic) techniques that provide the backbone of genomic analysis. These chapters cover in significant detail the fundamental principles underlying each technique and provide a firm background for the remainder of the text. Chapters 7­9 consider the need and methods for the development of physical maps. Chapter 7 primarily discusses chromosomal localization techniques, including in situ hybridization, FISH, and chromosome paintings. The next two chapters focus on the development of libraries and clones. In particular, Chapter 9 considers the limitations of current mapping and clone production. The current state and future of DNA sequencing is covered in the next three chapters. The first considers the current methods of DNA sequencing - especially gel-based methods of analysis, although other possible approaches (mass spectrometry) are introduced. Much of the chapter addresses the limitations of current methods, including analysis of error in sequencing and current bottlenecks in the sequencing effort. The next chapter describes the steps necessary to scale current technologies for the sequencing of entire genomes. Chapter 12 examines alternate methods for DNA sequencing. Initially, methods of single-molecule sequencing and sequencing by microscopy are introduced; the majority of the chapter is devoted to the development of DNA sequencing methods using chip microarrays and hybridization. The remaining chapters (13-15) consider the uses and analysis of DNA sequence information. The initial focus is on the identification of genes. Several examples are given of the use of DNA sequence information for diagnosis of inherited or infectious diseases. The sequence-specific manipulation of DNA is discussed in Chapter 14. The final chapter deals with the implications of large-scale sequencing, including methods for identifying genes and finding errors in DNA sequences, to the development of computer algorithms for the interpretation of DNA sequence information. The text figures are black and white line drawings that, although clearly done, seem a bit primitive for 1999. While I appreciated the simplicity of the drawings, many students accustomed to more colorful presentations will find them wanting. The four color figures in the center of the text seem an afterthought and add little to the text's clarity. Each chapter has a set of additional reading sources, mostly primary sources. Often, specialized topics are offset into boxes that provide clarification and amplification without cluttering the text. An appendix includes a list of the Web-based database resources. As an undergraduate instructor who has previously taught biochemistry, molecular biology, and a course on the human genome, I found many interesting tidbits and amplifications throughout the text. I would recommend this book as a text for an advanced undergraduate or beginning graduate course in genomics. Although the text works though several examples of genetic and genome analysis, additional problem/homework sets would need to be developed to ensure student comprehension. The text steers clear of the ethical implications of the Human Genome Initiative and remains true to its subtitle The Science and Technology .

Association of the Family Environment with Behavioural and Cognitive Outcomes in Children with Chromosome 22q11.2 Deletion Syndrome

ERIC Educational Resources Information Center

Allen, T. M.; Hersh, J.; Schoch, K.; Curtiss, K.; Hooper, S. R.; Shashi, V.

2014-01-01

Background: Children with 22q11.2 deletion syndrome (22q11DS) are at risk for social-behavioural and neurocognitive sequelae throughout development. The current study examined the impact of family environmental characteristics on social-behavioural and cognitive outcomes in this paediatric population. Method: Guardians of children with 22q11DS…

Quantifying and Understanding Effects from Wildlife, Radar, and Public Engagement on Future Wind Deployment

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

Tegen, Suzanne

This presentation provides an overview of findings from a report published in 2016 by researchers at the National Renewable Energy Laboratory, An Initial Evaluation of Siting Considerations on Current and Future Wind Deployment. The presentation covers the background for research, the Energy Department's Wind Vision, research methods, siting considerations, the wind project deployment process, and costs associated with siting considerations.

The Background to Current Theories of Scuffing

DTIC Science & Technology

1973-01-01

attention because, by neglecting axial flow , it can be treated in two dimensions. This has resulted in a fairly complete theoretical analysis...the contact. This method was essentially one of measuring the volume rate of flow through the contact, which was directly related to the pad...exit constriction. The pressure and temperature were also measured in the axial direction (105) and the results indicated that side leakage was

Voices of Young People with a History of Specific Language Impairment (SLI) in the First Year of Post-16 Education

ERIC Educational Resources Information Center

Palikara, Olympia; Lindsay, Geoff; Dockrell, Julie E.

2009-01-01

Background: Giving young people more and better opportunities to have their voices heard is a key feature of current educational policy and research internationally and in the UK. Aims: To examine the views of young people with a history of specific language impairment (SLI) as they entered post-16 education. Methods & Procedures: A total of…

Tobacco and Alcohol Use in People with Mild/Moderate Intellectual Disabilities: Giving Voice to Their Health Promotion Needs

ERIC Educational Resources Information Center

Kerr, Susan; Lawrence, Maggie; Middleton, Alan R.; Fitzsimmons, Lorna; Darbyshire, Christopher

2017-01-01

Background: Concerns have been raised about the use/misuse of tobacco and alcohol by people with mild/moderate intellectual disabilities. Aiming to address an identified gap in the current evidence base, this study sought to gain an understanding of the tobacco- and alcohol-related health promotion needs of this client group. Methods: Informed by…

A Revised Sexual Knowledge Assessment Tool for People with Intellectual Disabilities: Is Sexual Knowledge Related to Sexual Offending Behaviour?

ERIC Educational Resources Information Center

Talbot, T. J.; Langdon, Peter E.

2006-01-01

Background: The aim of the current study was to update an existing short measure of sexual knowledge and generate some initial reliability and normative data. Comparisons of sexual knowledge across several groups were made to examine whether or not a lack of sexual knowledge is related to sexual offending. Methods: The Bender Sexual Knowledge…

Assessment of the MPACT Resonance Data Generation Procedure

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

Kim, Kang Seog; Williams, Mark L.

Currently, heterogeneous models are being used to generate resonance self-shielded cross-section tables as a function of background cross sections for important nuclides such as 235U and 238U by performing the CENTRM (Continuous Energy Transport Model) slowing down calculation with the MOC (Method of Characteristics) spatial discretization and ESSM (Embedded Self-Shielding Method) calculations to obtain background cross sections. And then the resonance self-shielded cross section tables are converted into subgroup data which are to be used in estimating problem-dependent self-shielded cross sections in MPACT (Michigan Parallel Characteristics Transport Code). Although this procedure has been developed and thus resonance data have beenmore » generated and validated by benchmark calculations, assessment has never been performed to review if the resonance data are properly generated by the procedure and utilized in MPACT. This study focuses on assessing the procedure and a proper use in MPACT.« less

Conceptual knowledge representation: A cross-section of current research.

PubMed

Rogers, Timothy T; Wolmetz, Michael

2016-01-01

How is conceptual knowledge encoded in the brain? This special issue of Cognitive Neuropsychology takes stock of current efforts to answer this question through a variety of methods and perspectives. Across this work, three questions recur, each fundamental to knowledge representation in the mind and brain. First, what are the elements of conceptual representation? Second, to what extent are conceptual representations embodied in sensory and motor systems? Third, how are conceptual representations shaped by context, especially linguistic context? In this introductory article we provide relevant background on these themes and introduce how they are addressed by our contributing authors.

Exclusive Neutrino Charged Current Coherent Pion Production Cross Section Measurements in MINERvA

NASA Astrophysics Data System (ADS)

Higuera, A.

2012-03-01

MINERvA (Main Injector Experiment for v-A) is a neutrino scattering experiment in the 1-10 GeV energy range in the NuMI high-intensity neutrino beam at Fermi National Accelerator Laboratory. MINERvA is measuring neutrino/antineutrino scattering off a variety of different nuclear materials (C, Fe, Pb, He, H2O) and plans to measure the A-dependence of the Charged Current Coherent Pion Production cross section. We provide an outline of this measurement including the expected event rates and our methods for differentiating signal from background.

A platform for evolving intelligently interactive adversaries.

PubMed

Fogel, David B; Hays, Timothy J; Johnson, Douglas R

2006-07-01

Entertainment software developers face significant challenges in designing games with broad appeal. One of the challenges concerns creating nonplayer (computer-controlled) characters that can adapt their behavior in light of the current and prospective situation, possibly emulating human behaviors. This adaptation should be inherently novel, unrepeatable, yet within the bounds of realism. Evolutionary algorithms provide a suitable method for generating such behaviors. This paper provides background on the entertainment software industry, and details a prior and current effort to create a platform for evolving nonplayer characters with genetic and behavioral traits within a World War I combat flight simulator.

Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

DOE PAGES

Mace, Emily; Aalseth, Craig; Brandenberger, Jill; ...

2016-12-21

Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50–1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. Lastly, we present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

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

Mace, Emily; Aalseth, Craig; Brandenberger, Jill

Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50-1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. We present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

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

Mace, Emily; Aalseth, Craig; Brandenberger, Jill

Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50–1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. Lastly, we present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

Numerical simulation of large-scale field-aligned current generation from finite-amplitude magnetosonic waves

NASA Technical Reports Server (NTRS)

Yamauchi, M.

1994-01-01

A two-dimensional numerical simulation of finite-amplitude magnetohydrodynamic (MHD) magnetosonic waves is performed under a finite-velocity background convection condition. Isothermal cases are considered for simplicity. External dissipation is introduced by assuming that the field-aligned currents are generated in proportion to the accumulated charges. The simulation results are as follows: Paired field-aligned currents are found from the simulated waves. The flow directions of these field-aligned currents depend on the angle between the background convection and the wave normal, and hence two pairs of field-aligned currents are found from a bowed wave if we look at the overall structure. The majority of these field-aligned currents are closed within each pair rather than between two wings. These features are not observed under slow background convection. The result could be applied to the cusp current system and the substorm current system.

Engineering Ethics Education : Its Necessity, Objectives, Methods, Current State, and Challenges

NASA Astrophysics Data System (ADS)

Fudano, Jun

The importance of engineering ethics education has become widely recognized in the industrialized countries including Japan. This paper examines the background against which engineering ethics education is required, and reviews its objectives, methods, and challenges, as well as its current state. In pointing out important issues associated with the apparent acceptance and quantitative development of ethics education, especially after the establishment of the Japan Accreditation Board for Engineering Education in 1999, the author stresses that the most serious problem is the lack of common understanding on the objectives of engineering ethics education. As a strategy to improve the situation, the so-called “Ethics-across-the-Curriculum” approach is introduced. The author also claims that business/organization ethics which is consistent with engineering ethics should be promoted in Japan.

An AK-LDMeans algorithm based on image clustering

NASA Astrophysics Data System (ADS)

Chen, Huimin; Li, Xingwei; Zhang, Yongbin; Chen, Nan

2018-03-01

Clustering is an effective analytical technique for handling unmarked data for value mining. Its ultimate goal is to mark unclassified data quickly and correctly. We use the roadmap for the current image processing as the experimental background. In this paper, we propose an AK-LDMeans algorithm to automatically lock the K value by designing the Kcost fold line, and then use the long-distance high-density method to select the clustering centers to further replace the traditional initial clustering center selection method, which further improves the efficiency and accuracy of the traditional K-Means Algorithm. And the experimental results are compared with the current clustering algorithm and the results are obtained. The algorithm can provide effective reference value in the fields of image processing, machine vision and data mining.

MIT Participation in the Data Analysis of the XRS and XIS Instruments on the Astro-E2 Mission

NASA Technical Reports Server (NTRS)

Bautz, Mark

2005-01-01

Since the inception of this grant six weeks ago, we have completed the initial activation of the Suzaku X-ray Imaging Spectrometer (XIS) (on 13 August) and we have supported initial calibration observations. The instrument is performing very well in all respects. We have characterized the spectral resolution and effective area of each XIS sensor. We are especially excited about the scientific opportunities provided by the XIS'S back- illuminated sensor, which exhibits spectral resolution in the sub-keV band unmatched by any X-ray CCD currently in orbit. As specified in our proposal, we have established a web site (http://space.mit.edu/XIS) on which we maintain an up-to-date summary of instrument performance characteristics. Gain, spectral resolution and system noise, as well as residual background rates, are currently available on this site. Although the particle background level is low compared with Chandra and XMM, we are currently evaluating methods to reduce it still further. Techniques under study include use of 5x5 mode information and alternative grade selection methods. Although the primary responsibility for development of instrument response functions rests with our Japanese colleagues, we are incorporating our latest measurements of spectral resolution into some temporary response functions which we hope to make available to the Suzaku General Observer Facility and the Science Working Group(SWG). We are also preparing proposals for use of SWG observing time.

Solving a Higgs optimization problem with quantum annealing for machine learning.

PubMed

Mott, Alex; Job, Joshua; Vlimant, Jean-Roch; Lidar, Daniel; Spiropulu, Maria

2017-10-18

The discovery of Higgs-boson decays in a background of standard-model processes was assisted by machine learning methods. The classifiers used to separate signals such as these from background are trained using highly unerring but not completely perfect simulations of the physical processes involved, often resulting in incorrect labelling of background processes or signals (label noise) and systematic errors. Here we use quantum and classical annealing (probabilistic techniques for approximating the global maximum or minimum of a given function) to solve a Higgs-signal-versus-background machine learning optimization problem, mapped to a problem of finding the ground state of a corresponding Ising spin model. We build a set of weak classifiers based on the kinematic observables of the Higgs decay photons, which we then use to construct a strong classifier. This strong classifier is highly resilient against overtraining and against errors in the correlations of the physical observables in the training data. We show that the resulting quantum and classical annealing-based classifier systems perform comparably to the state-of-the-art machine learning methods that are currently used in particle physics. However, in contrast to these methods, the annealing-based classifiers are simple functions of directly interpretable experimental parameters with clear physical meaning. The annealer-trained classifiers use the excited states in the vicinity of the ground state and demonstrate some advantage over traditional machine learning methods for small training datasets. Given the relative simplicity of the algorithm and its robustness to error, this technique may find application in other areas of experimental particle physics, such as real-time decision making in event-selection problems and classification in neutrino physics.

Solving a Higgs optimization problem with quantum annealing for machine learning

NASA Astrophysics Data System (ADS)

Mott, Alex; Job, Joshua; Vlimant, Jean-Roch; Lidar, Daniel; Spiropulu, Maria

2017-10-01

The discovery of Higgs-boson decays in a background of standard-model processes was assisted by machine learning methods. The classifiers used to separate signals such as these from background are trained using highly unerring but not completely perfect simulations of the physical processes involved, often resulting in incorrect labelling of background processes or signals (label noise) and systematic errors. Here we use quantum and classical annealing (probabilistic techniques for approximating the global maximum or minimum of a given function) to solve a Higgs-signal-versus-background machine learning optimization problem, mapped to a problem of finding the ground state of a corresponding Ising spin model. We build a set of weak classifiers based on the kinematic observables of the Higgs decay photons, which we then use to construct a strong classifier. This strong classifier is highly resilient against overtraining and against errors in the correlations of the physical observables in the training data. We show that the resulting quantum and classical annealing-based classifier systems perform comparably to the state-of-the-art machine learning methods that are currently used in particle physics. However, in contrast to these methods, the annealing-based classifiers are simple functions of directly interpretable experimental parameters with clear physical meaning. The annealer-trained classifiers use the excited states in the vicinity of the ground state and demonstrate some advantage over traditional machine learning methods for small training datasets. Given the relative simplicity of the algorithm and its robustness to error, this technique may find application in other areas of experimental particle physics, such as real-time decision making in event-selection problems and classification in neutrino physics.

Current Sheet Formation in a Conical Theta Pinch Faraday Accelerator with Radio-frequency Assisted Discharge

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Hallock, Ashley K.; Choueiri, Edgar Y.

2008-01-01

Data from an inductive conical theta pinch accelerator are presented to gain insight into the process of inductive current sheet formation in the presence of a preionized background gas produced by a steady-state RF-discharge. The presence of a preionized plasma has been previously shown to allow for current sheet formation at lower discharge voltages and energies than those found in other pulsed inductive accelerator concepts, leading to greater accelerator efficiencies at lower power levels. Time-resolved magnetic probe measurements are obtained for different background pressures and pulse energies to characterize the effects of these parameters on current sheet formation. Indices are defined that describe time-resolved current sheet characteristics, such as the total current owing in the current sheet, the time-integrated total current ('strength'), and current sheet velocity. It is found that for a given electric field strength, maximums in total current, strength, and velocity occur for one particular background pressure. At other pressures, these current sheet indices are considerably smaller. The trends observed in these indices are explained in terms of the principles behind Townsend breakdown that lead to a dependence on the ratio of the electric field to the background pressure. Time-integrated photographic data are also obtained at the same experimental conditions, and qualitatively they compare quite favorably with the time-resolved magnetic field data.

A scene model of exosolar systems for use in planetary detection and characterisation simulations

NASA Astrophysics Data System (ADS)

Belu, A.; Thiébaut, E.; Ollivier, M.; Lagache, G.; Selsis, F.; Vakili, F.

2007-12-01

Context: Instrumental projects that will improve the direct optical finding and characterisation of exoplanets have advanced sufficiently to trigger organized investigation and development of corresponding signal processing algorithms. The first step is the availability of field-of-view (FOV) models. These can then be submitted to various instrumental models, which in turn produce simulated data, enabling the testing of processing algorithms. Aims: We aim to set the specifications of a physical model for typical FOVs of these instruments. Methods: The dynamic in resolution and flux between the various sources present in such a FOV imposes a multiscale, independent layer approach. From review of current literature and through extrapolations from currently available data and models, we derive the features of each source-type in the field of view likely to pass the instrumental filter at exo-Earth level. Results: Stellar limb darkening is shown to cause bias in leakage calibration if unaccounted for. Occurrence of perturbing background stars or galaxies in the typical FOV is unlikely. We extract galactic interstellar medium background emissions for current target lists. Galactic background can be considered uniform over the FOV, and it should show no significant drift with parallax. Our model specifications have been embedded into a Java simulator, soon to be made open-source. We have also designed an associated FITS input/output format standard that we present here. Work supported in part by the ESA/ESTEC contract 18701/04/NL/HB, led by Thales Alenia Space.

Knowledge and Acceptability of Long-Acting Reversible Contraception Among Adolescent Women Receiving School-Based Primary Care Services

PubMed Central

Hoopes, Andrea J.; Ahrens, Kym R.; Gilmore, Kelly; Cady, Janet; Haaland, Wren L.; Amies Oelschlager, Anne-Marie; Prager, Sarah

2016-01-01

Background: A key strategy to reduce unintended adolescent pregnancies is to expand access to long-acting reversible contraceptive (LARC) methods, including intrauterine devices and subdermal contraceptive implants. LARC services can be provided to adolescents in school-based health and other primary care settings, yet limited knowledge and negative attitudes about LARC methods may influence adolescents’ utilization of these methods. This study aimed to evaluate correlates of knowledge and acceptability of LARC methods among adolescent women at a school-based health center (SBHC). Methods: In this cross-sectional study, female patients receiving care at 2 SBHCs in Seattle, Washington completed an electronic survey about sexual and reproductive health. Primary outcomes were (1) LARC knowledge as measured by percentage correct of 10 true-false questions and (2) LARC acceptability as measured by participants reporting either liking the idea of having an intrauterine device (IUD)/subdermal implant or currently using one. Results: A total of 102 students diverse in race/ethnicity and socioeconomic backgrounds completed the survey (mean age 16.2 years, range 14.4-19.1 years). Approximately half reported a lifetime history of vaginal sex. Greater LARC knowledge was associated with white race (regression coefficient [coef] = 26.8; 95% CI 13.3-40.4; P < .001), history of vaginal intercourse (coef = 29.9; 95% CI 17.1-42.7; P < .001), and current/prior LARC use (coef = 22.8; 95% CI 6.5-40.0; P = .007). Older age was associated with lower IUD acceptability (odds ratio = 0.53, 95% CI 0.30-0.94; P = .029) while history of intercourse was associated with greater implant acceptability (odds ratio 5.66, 95% CI 1.46-22.0; P = .012). Discussion: Adolescent women in this SBHC setting had variable knowledge and acceptability of LARC. A history of vaginal intercourse was the strongest predictor of LARC acceptability. Our findings suggest a need for LARC counseling and education strategies, particularly for young women from diverse cultural backgrounds and those with less sexual experience. PMID:27067583

Search for neutrinoless double-electron capture of 156Dy

NASA Astrophysics Data System (ADS)

Finch, S. W.; Tornow, W.

2015-12-01

Background: Multiple large collaborations are currently searching for neutrinoless double-β decay, with the ultimate goal of differentiating the Majorana-Dirac nature of the neutrino. Purpose: Investigate the feasibility of resonant neutrinoless double-electron capture, an experimental alternative to neutrinoless double-β decay. Method: Two clover germanium detectors were operated underground in coincidence to search for the de-excitation γ rays of 156Gd following the neutrinoless double-electron capture of 156Dy. 231.95 d of data were collected at the Kimballton underground research facility with a 231.57 mg enriched 156Dy sample. Results: No counts were seen above background and half-life limits are set at O (1016-1018) yr for the various decay modes of 156Dy. Conclusion: Low background spectra were efficiently collected in the search for neutrinoless double-electron capture of 156Dy, although the low natural abundance and associated lack of large quantities of enriched samples hinders the experimental reach.

TU-F-BRD-01: Biomedical Informatics for Medical Physicists

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

Phillips, M; Kalet, I; McNutt, T

Biomedical informatics encompasses a very large domain of knowledge and applications. This broad and loosely defined field can make it difficult to navigate. Physicists often are called upon to provide informatics services and/or to take part in projects involving principles of the field. The purpose of the presentations in this symposium is to help medical physicists gain some knowledge about the breadth of the field and how, in the current clinical and research environment, they can participate and contribute. Three talks have been designed to give an overview from the perspective of physicists and to provide a more in-depth discussionmore » in two areas. One of the primary purposes, and the main subject of the first talk, is to help physicists achieve a perspective about the range of the topics and concepts that fall under the heading of 'informatics'. The approach is to de-mystify topics and jargon and to help physicists find resources in the field should they need them. The other talks explore two areas of biomedical informatics in more depth. The goal is to highlight two domains of intense current interest--databases and models--in enough depth into current approaches so that an adequate background for independent inquiry is achieved. These two areas will serve as good examples of how physicists, using informatics principles, can contribute to oncology practice and research. Learning Objectives: To understand how the principles of biomedical informatics are used by medical physicists. To put the relevant informatics concepts in perspective with regard to biomedicine in general. To use clinical database design as an example of biomedical informatics. To provide a solid background into the problems and issues of the design and use of data and databases in radiation oncology. To use modeling in the service of decision support systems as an example of modeling methods and data use. To provide a background into how uncertainty in our data and knowledge can be incorporated into modeling methods.« less

Reverse Current Shock Induced by Plasma-Neutral Collision

NASA Astrophysics Data System (ADS)

Wongwaitayakornkul, Pakorn; Haw, Magnus; Li, Hui; Li, Shengtai; Bellan, Paul

2017-10-01

The Caltech solar experiment creates an arched plasma-filled flux rope expanding into low density background plasma. A layer of electrical current flowing in the opposite direction with respect to the flux rope current is induced in the background plasma just ahead of the flux rope. Two dimensional spatial and temporal measurements by a 3-dimensional magnetic vector probe demonstrate the existence of this induced current layer forming ahead of the flux rope. The induced current magnitude is 20% of the magnitude of the current in the flux rope. The reverse current in the low density background plasma is thought to be a diamagnetic response that shields out the magnetic field ahead of the propagation. The spatial and magnetic characteristics of the reverse current layer are consistent with similar shock structures seen in 3-dimensional ideal MHD numerical simulations performed on the Turquoise supercomputer cluster using the Los Alamos COMPutational Astrophysics Simulation Suite. This discovery of the induced diamagnetic current provides useful insights for space and solar plasma.

Advanced Practice Registered Nurses and Physician Assistants in Sleep Centers and Clinics: A Survey of Current Roles and Educational Background

PubMed Central

Colvin, Loretta; Cartwright, Ann; Collop, Nancy; Freedman, Neil; McLeod, Don; Weaver, Terri E.; Rogers, Ann E.

2014-01-01

Study Objectives: To survey Advanced Practice Registered Nurse (APRN) and Physician Assistant (PA) utilization, roles and educational background within the field of sleep medicine. Methods: Electronic surveys distributed to American Academy of Sleep Medicine (AASM) member centers and APRNs and PAs working within sleep centers and clinics. Results: Approximately 40% of responding AASM sleep centers reported utilizing APRNs or PAs in predominantly clinical roles. Of the APRNs and PAs surveyed, 95% reported responsibilities in sleep disordered breathing and more than 50% in insomnia and movement disorders. Most APRNs and PAs were prepared at the graduate level (89%), with sleep-specific education primarily through “on the job” training (86%). All APRNs surveyed were Nurse Practitioners (NPs), with approximately double the number of NPs compared to PAs. Conclusions: APRNs and PAs were reported in sleep centers at proportions similar to national estimates of NPs and PAs in physicians' offices. They report predominantly clinical roles, involving common sleep disorders. Given current predictions that the outpatient healthcare structure will change and the number of APRNs and PAs will increase, understanding the role and utilization of these professionals is necessary to plan for the future care of patients with sleep disorders. Surveyed APRNs and PAs reported a significant deficiency in formal and standardized sleep-specific education. Efforts to provide formal and standardized educational opportunities for APRNs and PAs that focus on their clinical roles within sleep centers could help fill a current educational gap. Citation: Colvin L, Cartwright Ann, Collop N, Freedman N, McLeod D, Weaver TE, Rogers AE. Advanced practice registered nurses and physician assistants in sleep centers and clinics: a survey of current roles and educational background. J Clin Sleep Med 2014;10(5):581-587. PMID:24812545

The natural history of Charcot's neuroarthropathy.

PubMed

Nielson, David L; Armstrong, David G

2008-01-01

The goal of this article is to outline the progression of Charcot's neuroarthropathy. A historical background is detailed, with an emphasis on the current trends in the literature. Acute Charcot's neuroarthropathy requires a prompt diagnosis with the proper practical offloading methods of the affected limb. This, coupled with directed medical and surgical approaches designed to prevent or mitigate deformities, may subsequently reduce the risk of amputation in this high-risk population.

Relationship between Frequency and Intensity of Cigarette Smoking and TTFC/C among Students of the GYTS in Select Countries, 2007-2009

ERIC Educational Resources Information Center

Lam, Eugene; Giovino, Gary A.; Shin, Mikyong; Lee, Kyung A.; Rolle, Italia; Asma, Samira

2014-01-01

Background: This study assessed the construct validity of a measure of nicotine dependence that was used in the Global Youth Tobacco Survey (GYTS). Methods: Using 2007-2009 data from the GYTS, subjects from 6 countries were used to assess current smokers' odds of reporting time to first cigarette or craving positive (TTFC/C+) by the number of…

Treasure of the Past IX: Exposure Standardization of Iodine-125 Seeds Used for Brachytherapy

PubMed Central

Loftus, T. P.

2001-01-01

A method for calibrating iodine-125 seeds in terms of exposure has been established. The standard free-air ionization chamber, used for measuring soft x rays, was chosen for the measurements. Arrays of four to six seeds were used to enhance the ionization-current-to-background-current ratio. Seeds from an array were measured individually in a re-entrant chamber. The quotient of the exposure rate for the array by the sum of the ionization currents in the re-entrant chamber is the calibration factor for the re-entrant chamber. Calibration factors were established for three types of iodine-125 seeds. The overall uncertainty for the seed exposure calibrations is less than 6%. PMID:27500052

A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

2002-01-01

Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

Focal plane infrared readout circuit with automatic background suppression

NASA Technical Reports Server (NTRS)

Pain, Bedabrata (Inventor); Yang, Guang (Inventor); Sun, Chao (Inventor); Shaw, Timothy J. (Inventor); Wrigley, Chris J. (Inventor)

2002-01-01

A circuit for reading out a signal from an infrared detector includes a current-mode background-signal subtracting circuit having a current memory which can be enabled to sample and store a dark level signal from the infrared detector during a calibration phase. The signal stored by the current memory is subtracted from a signal received from the infrared detector during an imaging phase. The circuit also includes a buffered direct injection input circuit and a differential voltage readout section. By performing most of the background signal estimation and subtraction in a current mode, a low gain can be provided by the buffered direct injection input circuit to keep the gain of the background signal relatively small, while a higher gain is provided by the differential voltage readout circuit. An array of such readout circuits can be used in an imager having an array of infrared detectors. The readout circuits can provide a high effective handling capacity.

Toward real-time quantification of fluorescence molecular probes using target/background ratio for guiding biopsy and endoscopic therapy of esophageal neoplasia.

PubMed

Jiang, Yang; Gong, Yuanzheng; Rubenstein, Joel H; Wang, Thomas D; Seibel, Eric J

2017-04-01

Multimodal endoscopy using fluorescence molecular probes is a promising method of surveying the entire esophagus to detect cancer progression. Using the fluorescence ratio of a target compared to a surrounding background, a quantitative value is diagnostic for progression from Barrett's esophagus to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). However, current quantification of fluorescent images is done only after the endoscopic procedure. We developed a Chan-Vese-based algorithm to segment fluorescence targets, and subsequent morphological operations to generate background, thus calculating target/background (T/B) ratios, potentially to provide real-time guidance for biopsy and endoscopic therapy. With an initial processing speed of 2 fps and by calculating the T/B ratio for each frame, our method provides quasireal-time quantification of the molecular probe labeling to the endoscopist. Furthermore, an automatic computer-aided diagnosis algorithm can be applied to the recorded endoscopic video, and the overall T/B ratio is calculated for each patient. The receiver operating characteristic curve was employed to determine the threshold for classification of HGD/EAC using leave-one-out cross-validation. With 92% sensitivity and 75% specificity to classify HGD/EAC, our automatic algorithm shows promising results for a surveillance procedure to help manage esophageal cancer and other cancers inspected by endoscopy.

Current Methods in Health Behavior Research Among U.S. Community College Students: A Review of the Literature

PubMed Central

Pokhrel, Pallav; Little, Melissa A.; Herzog, Thaddeus A.

2016-01-01

The majority of health behavior research involving college students in the United States has focused on 4-year college students. Two-year or community college students have been less studied, although a significant proportion of U.S. undergraduates, primarily those from disadvantaged socioeconomic and/or racial/ethnic background, are enrolled in community colleges. Thus, there is a need to enhance health behavior and health promotion research among community college students. This study systematically reviewed 42 published, peer-reviewed health behavior studies conducted among U.S. community college students in order to determine the current state of research in the area with regard to behaviors studied, research designs used, recruitment and data collection strategies practiced, rates of student participation, and characteristics of the participants represented. Findings identified the methodological limitations of current research and suggested optimal recruitment and data collection methods suitable for various research needs. Findings are discussed in the context of enhancing health behavior research among U.S. community college students. PMID:24227658

Multiple imputation to account for measurement error in marginal structural models

PubMed Central

Edwards, Jessie K.; Cole, Stephen R.; Westreich, Daniel; Crane, Heidi; Eron, Joseph J.; Mathews, W. Christopher; Moore, Richard; Boswell, Stephen L.; Lesko, Catherine R.; Mugavero, Michael J.

2015-01-01

Background Marginal structural models are an important tool for observational studies. These models typically assume that variables are measured without error. We describe a method to account for differential and non-differential measurement error in a marginal structural model. Methods We illustrate the method estimating the joint effects of antiretroviral therapy initiation and current smoking on all-cause mortality in a United States cohort of 12,290 patients with HIV followed for up to 5 years between 1998 and 2011. Smoking status was likely measured with error, but a subset of 3686 patients who reported smoking status on separate questionnaires composed an internal validation subgroup. We compared a standard joint marginal structural model fit using inverse probability weights to a model that also accounted for misclassification of smoking status using multiple imputation. Results In the standard analysis, current smoking was not associated with increased risk of mortality. After accounting for misclassification, current smoking without therapy was associated with increased mortality [hazard ratio (HR): 1.2 (95% CI: 0.6, 2.3)]. The HR for current smoking and therapy (0.4 (95% CI: 0.2, 0.7)) was similar to the HR for no smoking and therapy (0.4; 95% CI: 0.2, 0.6). Conclusions Multiple imputation can be used to account for measurement error in concert with methods for causal inference to strengthen results from observational studies. PMID:26214338

Performance, Facility Pressure Effects, and Stability Characterization Tests of NASA's Hall Effect Rocket with Magnetic Shielding Thruster

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Yim, John; Herman, Daniel; Peterson, Peter Y.; Williams, George J.; Gilland, James; Hofer, Richard; Mikellides, Ioannis

2016-01-01

NASA's Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) has been the subject of extensive technology maturation in preparation for flight system development. Part of the technology maturation effort included experimental evaluation of the TDU-1 thruster with conducting and dielectric front pole cover materials in two different electrical configurations. A graphite front magnetic pole cover thruster configuration with the thruster body electrically tied to cathode, and an alumina front pole cover thruster configuration with the thruster body floating were evaluated. Both configurations were also evaluated at different facility background pressure conditions to evaluate background pressure effects on thruster operation. Performance characterization tests found that higher thruster performance was attained with the graphite front pole cover configuration with the thruster electrically tied to cathode. A total thrust efficiency of 68% and a total specific impulse of 2,820 s was demonstrated at a discharge voltage of 600 V and a discharge power of 12.5 kW. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations and with maps of the discharge current-voltage-magnetic field (IVB). Analysis of TDU-1 discharge current waveforms found that lower normalized discharge current peak-to-peak and root mean square magnitudes were attained when the thruster was electrically floated with alumina front pole covers. Background pressure effects characterization tests indicated that the thruster performance and stability were mostly invariant to changes in the facility background pressure for vacuum chamber pressure below 1×10-5 Torr-Xe (for thruster flow rates of 20.5 mg/s). Power spectral density analysis of the discharge current waveforms showed that increasing the vacuum chamber background pressure resulted in a higher discharge current dominant breathing mode frequency. Finally, IVB maps of the TDU-1 thruster indicated that the discharge current became more oscillatory with higher discharge current peak-to-peak and RMS values with increased facility background pressure at lower thruster mass flow rates; thruster operation at higher flow rates resulted in less change to the thruster's IVB characteristics with elevated background pressure.

Centile charts for birthweight for gestational age for Scottish singleton births

PubMed Central

Bonellie, Sandra; Chalmers, James; Gray, Ron; Greer, Ian; Jarvis, Stephen; Williams, Claire

2008-01-01

Background Centile charts of birthweight for gestational age are used to identify low birthweight babies. The charts currently used in Scotland are based on data from the 1970s and require updating given changes in birthweight and in the measurement of gestational age since then. Methods Routinely collected data of 100,133 singleton births occurring in Scotland from 1998–2003 were used to construct new centile charts using the LMS method. Results Centile charts for birthweight for sex and parity groupings were constructed for singleton birth and compared to existing charts used in Scottish hospitals. Conclusion Mean birthweight has been shown to have increased over recent decades. The differences shown between the new and currently used centiles confirm the need for more up-to-date centiles for birthweight for gestational age. PMID:18298810

Understanding and meeting injection device needs in multiple sclerosis: a survey of patient attitudes and practices

PubMed Central

Verdun di Cantogno, Elisabetta; Russell, Susan; Snow, Tom

2011-01-01

Background: All established disease-modifying drugs for multiple sclerosis require parenteral administration, which can cause difficulties for some patients, sometimes leading to suboptimal adherence. A new electronic autoinjection device has been designed to address these issues. Methods: Patients with relapsing multiple sclerosis currently receiving subcutaneous or intramuscular interferon beta-1a, interferon beta-1b, or glatiramer acetate completed an online questionnaire (July 4–25, 2008) that surveyed current injection practices, experiences with current injection methods, and impressions and appeal of the new device. Results: In total, 422 patients completed the survey, of whom 44% used autoinjectors, 43% prefilled syringes, and 13% syringes and vials; overall, 66% currently self-injected. Physical and psychological barriers to self-injection included difficulty with injections, needle phobia, and concerns over correct injection technique. Only 40% of respondents were “very satisfied” with their current injection method. The new electronic autoinjector was rated as “very appealing” by 65% of patients. The benefits of the new device included the ability to customize injection settings and to review dosing history. Conclusion: New technologies may help patients overcome physical and psychological barriers to self-injection. The combination of a reliable and flexible autoinjection device with dose-monitoring technology may improve communication between health care professionals and patients, and improve treatment adherence. PMID:21573048

Unsupervised background-constrained tank segmentation of infrared images in complex background based on the Otsu method.

PubMed

Zhou, Yulong; Gao, Min; Fang, Dan; Zhang, Baoquan

2016-01-01

In an effort to implement fast and effective tank segmentation from infrared images in complex background, the threshold of the maximum between-class variance method (i.e., the Otsu method) is analyzed and the working mechanism of the Otsu method is discussed. Subsequently, a fast and effective method for tank segmentation from infrared images in complex background is proposed based on the Otsu method via constraining the complex background of the image. Considering the complexity of background, the original image is firstly divided into three classes of target region, middle background and lower background via maximizing the sum of their between-class variances. Then, the unsupervised background constraint is implemented based on the within-class variance of target region and hence the original image can be simplified. Finally, the Otsu method is applied to simplified image for threshold selection. Experimental results on a variety of tank infrared images (880 × 480 pixels) in complex background demonstrate that the proposed method enjoys better segmentation performance and even could be comparative with the manual segmentation in segmented results. In addition, its average running time is only 9.22 ms, implying the new method with good performance in real time processing.

Selected methods for quantification of community exposure to aircraft noise

NASA Technical Reports Server (NTRS)

Edge, P. M., Jr.; Cawthorn, J. M.

1976-01-01

A review of the state-of-the-art for the quantification of community exposure to aircraft noise is presented. Physical aspects, people response considerations, and practicalities of useful application of scales of measure are included. Historical background up through the current technology is briefly presented. The developments of both single-event and multiple-event scales are covered. Selective choice is made of scales currently in the forefront of interest and recommended methodology is presented for use in computer programing to translate aircraft noise data into predictions of community noise exposure. Brief consideration is given to future programing developments and to supportive research needs.

Immunodiagnosis of childhood malignancies.

PubMed

Parham, D M; Holt, H

1999-09-01

Immunodiagnosis utilizing immunohistochemical techniques is currently the most commonly utilized and readily available method of ancillary diagnosis in pediatric oncopathology. The methodology comprises relatively simple steps, based on straightforward biologic concepts, and the reagents used are generally well characterized and widely used. The principle of cancer immunodiagnosis is based on the determination of neoplastic lineage using detection of proteins typical of cell differentiation pathways. Methodology sensitivity varies and has become greater with each new generation of tests, but technical draw-backs should be considered to avoid excessive background or nonspecific results. Automated instrumentation offers a degree of accuracy and reproducibility not easily attainable by manual methods.

The Matrix Element Method: Past, Present, and Future

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

Gainer, James S.; Lykken, Joseph; Matchev, Konstantin T.

2013-07-12

The increasing use of multivariate methods, and in particular the Matrix Element Method (MEM), represents a revolution in experimental particle physics. With continued exponential growth in computing capabilities, the use of sophisticated multivariate methods-- already common-- will soon become ubiquitous and ultimately almost compulsory. While the existence of sophisticated algorithms for disentangling signal and background might naively suggest a diminished role for theorists, the use of the MEM, with its inherent connection to the calculation of differential cross sections will benefit from collaboration between theorists and experimentalists. In this white paper, we will briefly describe the MEM and some ofmore » its recent uses, note some current issues and potential resolutions, and speculate about exciting future opportunities.« less

Validation studies and proficiency testing.

PubMed

Ankilam, Elke; Heinze, Petra; Kay, Simon; Van den Eede, Guy; Popping, Bert

2002-01-01

Genetically modified organisms (GMOs) entered the European food market in 1996. Current legislation demands the labeling of food products if they contain <1% GMO, as assessed for each ingredient of the product. To create confidence in the testing methods and to complement enforcement requirements, there is an urgent need for internationally validated methods, which could serve as reference methods. To date, several methods have been submitted to validation trials at an international level; approaches now exist that can be used in different circumstances and for different food matrixes. Moreover, the requirement for the formal validation of methods is clearly accepted; several national and international bodies are active in organizing studies. Further validation studies, especially on the quantitative polymerase chain reaction methods, need to be performed to cover the rising demand for new extraction methods and other background matrixes, as well as for novel GMO constructs.

Increasing the Response Rate of the Patient Satisfaction Survey of Inpatients at National Naval Medical Center

DTIC Science & Technology

1993-08-01

identify a method to improve the effectiveness of the current survey process to increase the response rate of the patients being sampled. As health care... consumer must have adequate representation to provide meaningful information for decision making by the health care organization. Background of the...the Total Quality Management (TQM) philosophy into the health care industry has increased the importance of listening to the customer (Matthews, 1992

Joint Services Electronics Program. Appendix

DTIC Science & Technology

1992-11-01

the accu- clude surface waves, creeping waves, multiple racy, convergence, and CPU times for the MM diffractions, shadowing effects , etc. A second ad...Method which is an approximation to the true current J Jn= A /m on the strip. The next section will discuss the - computation of the far zone...to the cavity (0 part of the incident plane wave captured by interior E•,. After a background discussion of the aperture at the open end is divided

An Exploration of the Differing Perceptions of Problem-Based Learning (PBL) from Students and Facilitators of Diverse Cultural Backgrounds, in the Fields of Theological and Nursing Education

ERIC Educational Resources Information Center

Fung, Nancy L. Y.

2013-01-01

Theological education has not widely utilized the PBL approach and there is very little research examining the utility of PBL in theological education. Lectures are currently the preferred teaching method in theological education, however, it is recognized that there is a need for a more holistic approach. As theological education is used in both…

Launch Vehicle Design and Optimization Methods and Priority for the Advanced Engineering Environment

NASA Technical Reports Server (NTRS)

Rowell, Lawrence F.; Korte, John J.

2003-01-01

NASA's Advanced Engineering Environment (AEE) is a research and development program that will improve collaboration among design engineers for launch vehicle conceptual design and provide the infrastructure (methods and framework) necessary to enable that environment. In this paper, three major technical challenges facing the AEE program are identified, and three specific design problems are selected to demonstrate how advanced methods can improve current design activities. References are made to studies that demonstrate these design problems and methods, and these studies will provide the detailed information and check cases to support incorporation of these methods into the AEE. This paper provides background and terminology for discussing the launch vehicle conceptual design problem so that the diverse AEE user community can participate in prioritizing the AEE development effort.

It’s like a juggling act: rheumatoid arthritis patient perspectives on daily life and flare while on current treatment regimes

PubMed Central

Morris, Marianne; Richards, Pam; Hughes, Rodney; Hewlett, Sarah

2014-01-01

Objective. The objective of this study was to explore patients’ experiences of RA daily life while on modern treatments. Methods. The methods of this study comprised semi-structured interviews with 15 RA patients, analysed using inductive thematic analysis. Results. Four themes suggest patients experience life with RA along a continuum from RA in the background to the foreground of their lives, underpinned by constant actions to maintain balance. Living with RA in the background shows patients experience continuous, daily symptoms, which they mediate through micromanagement (mediating the impact of RA on daily life), while learning to incorporate RA into their identity (redefining me). RA moving into the foreground shows patients experience fluctuating symptoms (unwelcome reminders) that may or may not lead to a flare (trying to make sense of fluctuation). Dealing with RA in the foreground shows how patients attempt to manage RA flares (trying to regain control) and decide to seek medical help only after feeling they are losing control. Patients employ a stepped approach to self-management (mediation ladder) as symptoms increase, with seeking medical help often seen as the last resort. Patients seek to find a balance between managing their fluctuating RA and living their daily lives. Conclusion. Patients move back and forth along a continuum of RA in the background vs the foreground by balancing self-management of symptoms and everyday life. Clinicians need to appreciate that daily micromanagement is needed, even on current treatment regimes. Further research is needed to quantify the level and impact of daily symptoms and identify barriers and facilitators to seeking help. PMID:24357813

Nanoscale Surface Modifications of Orthopaedic Implants: State of the Art and Perspectives

PubMed Central

Staruch, RMT; Griffin, MF; Butler, PEM

2016-01-01

Background: Orthopaedic implants such as the total hip or total knee replacement are examples of surgical interventions with postoperative success rates of over 90% at 10 years. Implant failure is associated with wear particles and pain that requires surgical revision. Improving the implant - bone surface interface is a key area for biomaterial research for future clinical applications. Current implants utilise mechanical, chemical or physical methods for surface modification. Methods: A review of all literature concerning the nanoscale surface modification of orthopaedic implant technology was conducted. Results: The techniques and fabrication methods of nanoscale surface modifications are discussed in detail, including benefits and potential pitfalls. Future directions for nanoscale surface technology are explored. Conclusion: Future understanding of the role of mechanical cues and protein adsorption will enable greater flexibility in surface control. The aim of this review is to investigate and summarise the current concepts and future directions for controlling the implant nanosurface to improve interactions. PMID:28217214

Efficacy of Selected Electrical Therapies on Chronic Low Back Pain: A Comparative Clinical Pilot Study.

PubMed

Rajfur, Joanna; Pasternok, Małgorzata; Rajfur, Katarzyna; Walewicz, Karolina; Fras, Beata; Bolach, Bartosz; Dymarek, Robert; Rosinczuk, Joanna; Halski, Tomasz; Taradaj, Jakub

2017-01-07

BACKGROUND In the currently available research publications on electrical therapy of low back pain, generally no control groups or detailed randomization were used, and such studies were often conducted with relatively small groups of patients, based solely on subjective questionnaires and pain assessment scales (lacking measurement methods to objectify the therapeutic progress). The available literature also lacks a comprehensive and large-scale clinical study. The purpose of this study was to assess the effects of treating low back pain using selected electrotherapy methods. The study assesses the influence of individual electrotherapeutic treatments on reduction of pain, improvement of the range of movement in lower section of the spine, and improvement of motor functions and mobility. MATERIAL AND METHODS The 127 patients qualified for the therapy (ultimately, 123 patients completed the study) and assigned to 6 comparison groups: A - conventional TENS, B - acupuncture-like TENS, C - high-voltage electrical stimulation, D - interferential current stimulation, E - diadynamic current, and F - control group. RESULTS The research showed that using electrical stimulation with interferential current penetrating deeper into the tissues results in a significant and more efficient elimination of pain, and an improvement of functional ability of patients suffering from low back pain on the basis of an analysis of both subjective and objective parameters. The TENS currents and high voltage were helpful, but not as effective. The use of diadynamic currents appears to be useless. CONCLUSIONS Selected electrical therapies (interferential current, TENS, and high voltage) appear to be effective in treating chronic low back pain.

Efficacy of Selected Electrical Therapies on Chronic Low Back Pain: A Comparative Clinical Pilot Study

PubMed Central

Rajfur, Joanna; Pasternok, Małgorzata; Rajfur, Katarzyna; Walewicz, Karolina; Fras, Beata; Bolach, Bartosz; Dymarek, Robert; Rosinczuk, Joanna; Halski, Tomasz; Taradaj, Jakub

2017-01-01

Background In the currently available research publications on electrical therapy of low back pain, generally no control groups or detailed randomization were used, and such studies were often conducted with relatively small groups of patients, based solely on subjective questionnaires and pain assessment scales (lacking measurement methods to objectify the therapeutic progress). The available literature also lacks a comprehensive and large-scale clinical study. The purpose of this study was to assess the effects of treating low back pain using selected electrotherapy methods. The study assesses the influence of individual electrotherapeutic treatments on reduction of pain, improvement of the range of movement in lower section of the spine, and improvement of motor functions and mobility. Material/Methods The 127 patients qualified for the therapy (ultimately, 123 patients completed the study) and assigned to 6 comparison groups: A – conventional TENS, B – acupuncture-like TENS, C – high-voltage electrical stimulation, D – interferential current stimulation, E – diadynamic current, and F – control group. Results The research showed that using electrical stimulation with interferential current penetrating deeper into the tissues results in a significant and more efficient elimination of pain, and an improvement of functional ability of patients suffering from low back pain on the basis of an analysis of both subjective and objective parameters. The TENS currents and high voltage were helpful, but not as effective. The use of diadynamic currents appears to be useless. Conclusions Selected electrical therapies (interferential current, TENS, and high voltage) appear to be effective in treating chronic low back pain. PMID:28062862

Extended morphological processing: a practical method for automatic spot detection of biological markers from microscopic images.

PubMed

Kimori, Yoshitaka; Baba, Norio; Morone, Nobuhiro

2010-07-08

A reliable extraction technique for resolving multiple spots in light or electron microscopic images is essential in investigations of the spatial distribution and dynamics of specific proteins inside cells and tissues. Currently, automatic spot extraction and characterization in complex microscopic images poses many challenges to conventional image processing methods. A new method to extract closely located, small target spots from biological images is proposed. This method starts with a simple but practical operation based on the extended morphological top-hat transformation to subtract an uneven background. The core of our novel approach is the following: first, the original image is rotated in an arbitrary direction and each rotated image is opened with a single straight line-segment structuring element. Second, the opened images are unified and then subtracted from the original image. To evaluate these procedures, model images of simulated spots with closely located targets were created and the efficacy of our method was compared to that of conventional morphological filtering methods. The results showed the better performance of our method. The spots of real microscope images can be quantified to confirm that the method is applicable in a given practice. Our method achieved effective spot extraction under various image conditions, including aggregated target spots, poor signal-to-noise ratio, and large variations in the background intensity. Furthermore, it has no restrictions with respect to the shape of the extracted spots. The features of our method allow its broad application in biological and biomedical image information analysis.

Prospects for pharmacologic inhibition of hepatic glucose production.

PubMed

Kurukulasuriya, R; Link, J T; Madar, D J; Pei, Z; Rohde, J J; Richards, S J; Souers, A J; Szczepankiewicz, B G

2003-01-01

Type 2 diabetes is a widespread disease where effective pharmacologic therapies can have a profound beneficial public health impact. Increased hepatic glucose production (HGP) is observed in diabetics and its moderation by currently available agents provides therapeutic benefits. This review describes the challenges associated with the discovery of small molecules that inhibit HGP. Gluconeogenesis, glycogenolysis, liver architecture, and hepatocyte composition are described to provide background information on hepatic function. Current methods of target validation for drug discovery, HGP measurement, diabetes animal models, as well as current drug therapies are covered. In the accompanying review article the new drug targets being probed to produce the next generation of therapies are described. Significant pharmaceutical and academic efforts to pharmacologically inhibit HGP has the opportunity to provide new therapeutics for type 2 diabetics.

Nonaqueous capillary electrophoresis of dextromethorphan and its metabolites.

PubMed

Pelcová, Marta; Langmajerová, Monika; Cvingráfová, Eliška; Juřica, Jan; Glatz, Zdeněk

2014-10-01

This study deals with the nonaqueous capillary electrophoretic separation of dextromethorphan and its metabolites using a methanolic background electrolyte. The optimization of separation conditions was performed in terms of the resolution of dextromethorphan and dextrorphan and the effect of separation temperature, voltage, and the characteristics of the background electrolyte were studied. Complete separation of all analytes was achieved in 40 mM ammonium acetate dissolved in methanol. Hydrodynamic injection was performed at 3 kPa for 4 s. The separation voltage was 20 kV accompanied by a low electric current. The ultraviolet detection was performed at 214 nm, the temperature of the capillary was 25°C. These conditions enabled the separation of four analytes plus the internal standard within 9 min. Further, the developed method was validated in terms of linearity, sensitivity, and repeatability. Rat liver perfusate samples were subjected to the nonaqueous capillary electrophoretic method to illustrate its applicability. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Accumulating pyramid spatial-spectral collaborative coding divergence for hyperspectral anomaly detection

NASA Astrophysics Data System (ADS)

Sun, Hao; Zou, Huanxin; Zhou, Shilin

2016-03-01

Detection of anomalous targets of various sizes in hyperspectral data has received a lot of attention in reconnaissance and surveillance applications. Many anomaly detectors have been proposed in literature. However, current methods are susceptible to anomalies in the processing window range and often make critical assumptions about the distribution of the background data. Motivated by the fact that anomaly pixels are often distinctive from their local background, in this letter, we proposed a novel hyperspectral anomaly detection framework for real-time remote sensing applications. The proposed framework consists of four major components, sparse feature learning, pyramid grid window selection, joint spatial-spectral collaborative coding and multi-level divergence fusion. It exploits the collaborative representation difference in the feature space to locate potential anomalies and is totally unsupervised without any prior assumptions. Experimental results on airborne recorded hyperspectral data demonstrate that the proposed methods adaptive to anomalies in a large range of sizes and is well suited for parallel processing.

Current status of quality evaluation of nursing care through director review and reflection from the Nursing Quality Control Centers

PubMed Central

Duan, Xia; Shi, Yan

2014-01-01

Background: The quality evaluation of nursing care is a key link in medical quality management. It is important and worth studying for the nursing supervisors to know the disadvantages during the process of quality evaluation of nursing care and then to improve the whole nursing quality. This study was to provide director insight on the current status of quality evaluation of nursing care from Nursing Quality Control Centers (NQCCs). Material and Methods: This qualitative study used a sample of 12 directors from NQCCs who were recruited from 12 provinces in China to evaluate the current status of quality evaluation of nursing care. Data were collected by in-depth interviews. Content analysis method was used to analyze the data. Results: Four themes emerged from the data: 1) lag of evaluation index; 2) limitations of evaluation content; 3) simplicity of evaluation method; 4) excessive emphasis on terminal quality. Conclusion: It is of great realistic significance to ameliorate nursing quality evaluation criteria, modify the evaluation content based on patient needs-oriented idea, adopt scientific evaluation method to evaluate nursing quality, and scientifically and reasonably draw horizontal comparisons of nursing quality between hospitals, as well as longitudinal comparisons of a hospital’s nursing quality. These methods mentioned above can all enhance a hospital’s core competitiveness and benefit more patients. PMID:25419427

Position and speed control of brushless DC motors using sensorless techniques and application trends.

PubMed

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks.

Recent improvements in oily wastewater treatment: Progress, challenges, and future opportunities.

PubMed

Jamaly, Sanaa; Giwa, Adewale; Hasan, Shadi Wajih

2015-11-01

Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications. These include electrochemical treatment, membrane filtration, biological treatment, hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation, and destabilization of emulsions through the use of zeolites and other natural minerals. This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed. Copyright © 2015. Published by Elsevier B.V.

Completion of the swine genome will simplify the production of swine as a large animal biomedical model

PubMed Central

2012-01-01

Background Anatomic and physiological similarities to the human make swine an excellent large animal model for human health and disease. Methods Cloning from a modified somatic cell, which can be determined in cells prior to making the animal, is the only method available for the production of targeted modifications in swine. Results Since some strains of swine are similar in size to humans, technologies that have been developed for swine can be readily adapted to humans and vice versa. Here the importance of swine as a biomedical model, current technologies to produce genetically enhanced swine, current biomedical models, and how the completion of the swine genome will promote swine as a biomedical model are discussed. Conclusions The completion of the swine genome will enhance the continued use and development of swine as models of human health, syndromes and conditions. PMID:23151353

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

Ali, Elsayed

Purpose: To characterize and correct for radiation-induced background (RIB) observed in the signals from a class of scanning water tanks. Methods: A method was developed to isolate the RIB through detector measurements in the background-free linac console area. Variation of the RIB against a large number of parameters was characterized, and its impact on basic clinical data for photon and electron beams was quantified. Different methods to minimize and/or correct for the RIB were proposed and evaluated. Results: The RIB is due to the presence of the electrometer and connection box in a low background radiation field (by design). Themore » absolute RIB current with a biased detector is up to 2 pA, independent of the detector size, which is 0.6% and 1.5% of the central axis reference signal for a standard and a mini scanning chamber, respectively. The RIB monotonically increases with field size, is three times smaller for detectors that do not require a bias (e.g., diodes), is up to 80% larger for positive (versus negative) polarity, decreases with increasing photon energy, exhibits a single curve versus dose rate at the electrometer location, and is negligible for electron beams. Data after the proposed field-size correction method agree with point measurements from an independent system to within a few tenth of a percent for output factor, head scatter, depth dose at depth, and out-of-field profile dose. Manufacturer recommendations for electrometer placement are insufficient and sometimes incorrect. Conclusions: RIB in scanning water tanks can have a non-negligible effect on dosimetric data.« less

Organic micropollutants paracetamol and ibuprofen-toxicity, biodegradation, and genetic background of their utilization by bacteria.

PubMed

Żur, Joanna; Piński, Artur; Marchlewicz, Ariel; Hupert-Kocurek, Katarzyna; Wojcieszyńska, Danuta; Guzik, Urszula

2018-06-19

Currently, analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) are classified as one of the most emerging group of xenobiotics and have been detected in various natural matrices. Among them, monocyclic paracetamol and ibuprofen, widely used to treat mild and moderate pain are the most popular. Since long-term adverse effects of these xenobiotics and their biological and pharmacokinetic activity especially at environmentally relevant concentrations are better understood, degradation of such contaminants has become a major concern. Moreover, to date, conventional wastewater treatment plants (WWTPs) are not fully adapted to remove that kind of micropollutants. Bioremediation processes, which utilize bacterial strains with increased degradation abilities, seem to be a promising alternative to the chemical methods used so far. Nevertheless, despite the wide prevalence of paracetamol and ibuprofen in the environment, toxicity and mechanism of their microbial degradation as well as genetic background of these processes remain not fully characterized. In this review, we described the current state of knowledge about toxicity and biodegradation mechanisms of paracetamol and ibuprofen and provided bioinformatics analysis concerning the genetic bases of these xenobiotics decomposition.

A Spatial and Temporal Characterization of the Background Neutron Environment at the Navy and Marine Corps Memorial Stadium

DTIC Science & Technology

2017-04-01

developing informed survey protocols. Experimental Method The neutron detector used in this research was the Large Neutron Sensor (LNS), containing...are useful in planning, conducting, and assessing the utility and limitations of radiation surveys using current state-of-the-art portable or...34,000. In a security environment, where large public venues may be a target for terrorist activity, the ability to survey venues for radio- logical

Numerical experiment to estimate the validity of negative ion diagnostic using photo-detachment combined with Langmuir probing

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

Oudini, N.; Sirse, N.; Ellingboe, A. R.

2015-07-15

This paper presents a critical assessment of the theory of photo-detachment diagnostic method used to probe the negative ion density and electronegativity α = n{sub -}/n{sub e}. In this method, a laser pulse is used to photo-detach all negative ions located within the electropositive channel (laser spot region). The negative ion density is estimated based on the assumption that the increase of the current collected by an electrostatic probe biased positively to the plasma is a result of only the creation of photo-detached electrons. In parallel, the background electron density and temperature are considered as constants during this diagnostics. While the numericalmore » experiments performed here show that the background electron density and temperature increase due to the formation of an electrostatic potential barrier around the electropositive channel. The time scale of potential barrier rise is about 2 ns, which is comparable to the time required to completely photo-detach the negative ions in the electropositive channel (∼3 ns). We find that neglecting the effect of the potential barrier on the background plasma leads to an erroneous determination of the negative ion density. Moreover, the background electron velocity distribution function within the electropositive channel is not Maxwellian. This is due to the acceleration of these electrons through the electrostatic potential barrier. In this work, the validity of the photo-detachment diagnostic assumptions is questioned and our results illustrate the weakness of these assumptions.« less

Latent variable method for automatic adaptation to background states in motor imagery BCI

NASA Astrophysics Data System (ADS)

Dagaev, Nikolay; Volkova, Ksenia; Ossadtchi, Alexei

2018-02-01

Objective. Brain-computer interface (BCI) systems are known to be vulnerable to variabilities in background states of a user. Usually, no detailed information on these states is available even during the training stage. Thus there is a need in a method which is capable of taking background states into account in an unsupervised way. Approach. We propose a latent variable method that is based on a probabilistic model with a discrete latent variable. In order to estimate the model’s parameters, we suggest to use the expectation maximization algorithm. The proposed method is aimed at assessing characteristics of background states without any corresponding data labeling. In the context of asynchronous motor imagery paradigm, we applied this method to the real data from twelve able-bodied subjects with open/closed eyes serving as background states. Main results. We found that the latent variable method improved classification of target states compared to the baseline method (in seven of twelve subjects). In addition, we found that our method was also capable of background states recognition (in six of twelve subjects). Significance. Without any supervised information on background states, the latent variable method provides a way to improve classification in BCI by taking background states into account at the training stage and then by making decisions on target states weighted by posterior probabilities of background states at the prediction stage.

Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

PubMed Central

Scatolini, Fabio; Alves, Cláudio Jorge Pinto

2016-01-01

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures. PMID:28099658

Substantial Expansion of Detectable Size Range in Ionic Current Sensing through Pores by Using a Microfluidic Bridge Circuit.

PubMed

Yasaki, Hirotoshi; Yasui, Takao; Yanagida, Takeshi; Kaji, Noritada; Kanai, Masaki; Nagashima, Kazuki; Kawai, Tomoji; Baba, Yoshinobu

2017-10-11

Measuring ionic currents passing through nano- or micropores has shown great promise for the electrical discrimination of various biomolecules, cells, bacteria, and viruses. However, conventional measurements have shown there is an inherent limitation to the detectable particle volume (1% of the pore volume), which critically hinders applications to real mixtures of biomolecule samples with a wide size range of suspended particles. Here we propose a rational methodology that can detect samples with the detectable particle volume of 0.01% of the pore volume by measuring a transient current generated from the potential differences in a microfluidic bridge circuit. Our method substantially suppresses the background ionic current from the μA level to the pA level, which essentially lowers the detectable particle volume limit even for relatively large pore structures. Indeed, utilizing a microscale long pore structure (volume of 5.6 × 10 4 aL; height and width of 2.0 × 2.0 μm; length of 14 μm), we successfully detected various samples including polystyrene nanoparticles (volume: 4 aL), bacteria, cancer cells, and DNA molecules. Our method will expand the applicability of ionic current sensing systems for various mixed biomolecule samples with a wide size range, which have been difficult to measure by previously existing pore technologies.

A new method for the determination of Gadolinium in ppq levels

NASA Astrophysics Data System (ADS)

Brünjes, Robert; Bichler, Andrea; Hofmann, Thilo

2015-04-01

The use of Gadolinium (Gd) complexes as a contrast agent in Magnetic Resonance Imaging (MRI) results in an enhanced Gd input in the aquatic environment. Gd-complexes are excreted by humans unmetabolized within 12h after application. Passing the sewage systems with almost no degradation taking place, they successively reach surface waters, which make Gd a capable tracer for surface water/groundwater (SW/GW) interactions. The natural background concentration of Gd and other rare earth elements (REE) occur at ultratrace levels [low ng/L]. Crust-normalized REE patterns show positive Gd-anomalies in surface water, groundwater, and recently also in tap water. The difference between the total concentration and its natural background concentration estimated by the REE pattern is the anthropogenic Gd. Not only densely populated areas are affected by the presence of anthropogenic Gd. Studies have shown that even in rural areas without MRI facilities, anthropogenic Gd can be detected, since people are sent home after treatment. However, low input concentrations and mixing with natural waters lead to a decrease of Gd concentration below the current limit of quantification (LOQ) [1-5ng/L]. Often anthropogenic Gd cannot be calculated, although it is present, because natural background concentration cannot be determined with current methods, in particular in areas with low waste water load (e.g. headwater catchments). A new method using an on-line preconcentration system "SeaFAST" (Elemental Scientific Inc., USA), in combination with a desolvation system "Apex Q" (Elemental Scientific Inc., USA) and a QQQ-ICP-MS instrument (Agilent Technologies, Japan) does lower the LOQ for REE by a factor of 10 to 20. The SeaFAST-system uses a resin with ethylenediaminetriacetic acid and iminodiacetic acid functional groups to preconcentrate specifically REE as they are exclusively trivalent while anions, alkali and alkaline earth cations are washed out. The Apex Q interface is also supposed to significantly lower oxide interferences. We also evaluate a pretreatment in order to degrade the complexes and reach high recoveries of anthropogenic Gd. Our method will provide a determination of REE in ppq-levels, that significantly improves the differentiation between naturally and anthropogenic Gd. This will allow the detection of less than 1% waste water in SW and GW and finally increase the areas where studies of anthropogenic Gd could be conducted. A first application of our method was conducted during a field study in November 2014.

High sensitivity of spontaneous spike frequency to sodium leak current in a Lymnaea pacemaker neuron.

PubMed

Lu, T Z; Kostelecki, W; Sun, C L F; Dong, N; Pérez Velázquez, J L; Feng, Z-P

2016-12-01

The spontaneous rhythmic firing of action potentials in pacemaker neurons depends on the biophysical properties of voltage-gated ion channels and background leak currents. The background leak current includes a large K + and a small Na + component. We previously reported that a Na + -leak current via U-type channels is required to generate spontaneous action potential firing in the identified respiratory pacemaker neuron, RPeD1, in the freshwater pond snail Lymnaea stagnalis. We further investigated the functional significance of the background Na + current in rhythmic spiking of RPeD1 neurons. Whole-cell patch-clamp recording and computational modeling approaches were carried out in isolated RPeD1 neurons. The whole-cell current of the major ion channel components in RPeD1 neurons were characterized, and a conductance-based computational model of the rhythmic pacemaker activity was simulated with the experimental measurements. We found that the spiking rate is more sensitive to changes in the Na + leak current as compared to the K + leak current, suggesting a robust function of Na + leak current in regulating spontaneous neuronal firing activity. Our study provides new insight into our current understanding of the role of Na + leak current in intrinsic properties of pacemaker neurons. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Improved thin-layer chromatography bioautographic assay for the detection of actylcholinesterase inhibitors in plants.

PubMed

Yang, Zhong-Duo; Song, Zhu-Wen; Ren, Jin; Yang, Ming-Jun; Li, Shuo

2011-01-01

Thin-layer chromatography (TLC) bioautographic method is a simple and rapid method to screen acetylcholinesterase inhibitors from plant extracts. However, the high consumption of enzyme (6 U/mL) in current methods makes the procedure expensive, which is an obstacle to scientific research centers lacking funding. To develop a new low-cost TLC bioautographic method. A series of compounds, as substrates, were synthesised and their ability to be hydrolysed by acetylcholinesterase was evaluated by the HPLC method. 4-Methoxyphenyl acetate (14) was proved to be an appropriate substrate for TLC bioautographic assay. Therefore a new and cheap TLC bioautographic assay was set up. The mechanism of this new method is that the enzyme converts 4-methoxylphenyl acetate into 4-methoxyphenol, which reacts with a solution of potassium ferricyanide ([K₃(FeCN)₆]) and iron chloride hexahydrate (FeCl₃·6H₂O) to make an aquamarine blue coloured background on the TLC plates. Regions of the TLC plate which contain acetylcholinesterase inhibitors show up as light yellow spots against the background. The consumption of enzyme (1 U/mL) in the new method is low and the detection limit of two known acetylcholinesterase inhibitors, huperzine A (0.0001 μg) and physostigmine (0.001 μg), for this assay are close to published values. A low-cost TLC bioautographic method was developed, which will benefit research groups pursuing natural acetylcholinesterase inhibitors. Copyright © 2011 John Wiley & Sons, Ltd.

A Survey of Hospice Volunteer Coordinators: Training Methods and Objectives of Current Hospice Volunteer Training Programs.

PubMed

Brock, Cara M; Herndon, Christopher M

2017-06-01

Currently more than 5800 hospice organizations operate in the United States. 1 Hospice organizations are required by the Centers for Medicare and Medicaid Services (CMS) to use volunteers for services provided to patients. 2 Although CMS regulates the amount of hours hospice volunteers should provide, there are currently no national requirements for objectives of training. 3 The purpose of this study was to gather information from a sample of hospices regarding volunteer coordinator background, current training for volunteers, importance of training objectives, and any comments regarding additional objectives. Representative state hospice organizations were contacted by e-mail requesting their participation and distribution of the survey throughout their member hospices. The survey asked demographical questions, along with ratings of training components based on perceived level of importance and time spent on each objective. A total of 90 surveys were received, and the response rate was undeterminable. Results showed the majority of hospices were nonprofit, had less than 100 currently trained volunteers, and maintained an average daily patient census of less than 50. Questions regarding training programs indicated that most use live lecture methods of approximately 19 hours or less in duration. Overall, responding hospice organizations agreed that all objectives surveyed were important in training volunteers. The small number of respondents to this survey makes generalization nationwide difficult, however it is a strong starting point for the development of further surveys on hospice volunteer training and achieving a standardized set of training objectives and delivery methods.

Increasing the Efficiency of Electron Microprobe Measurements of Minor and Trace Elements in Rutile

NASA Astrophysics Data System (ADS)

Neill, O. K.; Mattinson, C. G.; Donovan, J.; Hernández Uribe, D.; Sains, A.

2016-12-01

Minor and trace element contents of rutile, an accessory mineral found in numerous lithologic settings, has many applications for interpreting earth systems. While these applications vary widely, they share a need for precise and accurate elemental measurements. The electron microprobe can be used to measure rutile compositions, although long X-ray counting times are necessary to achieve acceptable precision. Continuum ("background") intensity can be estimated using the iterative Mean Atomic Number (MAN) method of Donovan and Tingle (1996), obviating the need for direct off-peak background measurements, and reducing counting times by half. For this study, several natural and synthetic rutiles were measured by electron microprobe. Data was collected once but reduced twice, using off-peak and an MAN background corrections, allowing direct comparison of the two methods without influence of other variables (counting time, analyte homogeneity, beam current, calibration standards, etc.). These measurements show that, if a "blank" correction (Donovan et al., 2011, 2016) is used, minor and trace elements of interest can be measured in rutile using the MAN background method in half the time of traditional off-peak measurements, without sacrificing accuracy or precision (Figure 1). This method has already been applied to Zr-in-rutile thermometry of ultra-high pressure metamorphic rocks from the North Qaidam terrane in northwest China. Finally, secondary fluorescence of adjacent phases by continuum X-rays can lead to artificially elevated concentrations. For example, when measuring Zr, care should be taken to avoid analytical spots within 100 microns of zircon or baddeleyite crystals. References: 1) J.J. Donovan and T.N Tingle (1996) J. Microscopy, 2(1), 1-7 2) J.J. Donovan, H.A. Lowers, and B.G. Rusk (2011) Am. Mineral., 96, 274­282 3) J.J. Donovan, J.W. Singer and J.T. Armstrong (2016) Am. Mineral., 101, 1839-1853 4) G.L. Lovizotto et al. (2009) Chem. Geol., 261, 346-369

Blind tests of methods for InSight Mars mission: Open scientific challenge

NASA Astrophysics Data System (ADS)

Clinton, John; Ceylan, Savas; Giardini, Domenico; Khan, Amir; van Driel, Martin; Böse, Maren; Euchner, Fabian; Garcia, Raphael F.; Drilleau, Mélanie; Lognonné, Philippe; Panning, Mark; Banerdt, Bruce

2017-04-01

The Marsquake Service (MQS) will be the ground segment service within the InSight mission to Mars, which will deploy a single seismic station on Elysium Planitia in November 2018. The main tasks of the MQS are the identification and characterisation of seismicity, and managing the Martian seismic event catalogue. In advance of the mission, we have developed a series of single station event location methods that rely on a priori 1D and 3D structural models. In coordination with the Mars Structural Service, we expect to use iterative inversion techniques to revise these structural models and event locations. In order to seek methodological advancements and test our current approaches, we have designed a blind test case using Martian synthetics combined with realistic noise models for the Martian surface. We invite all scientific parties that are interested in single station approaches and in exploring the Martian time-series to participate and contribute to our blind test. We anticipate the test will can improve currently developed location and structural inversion techniques, and also allow us explore new single station techniques for moment tensor and magnitude determination. The waveforms for our test case are computed employing AxiSEM and Instaseis for a randomly selected 1D background model and event catalogue that is statistically consistent with our current expectation of Martian seismicity. Realistic seismic surface noise is superimposed to generate a continuous time-series spanning 6 months. The event catalog includes impacts as well as Martian quakes. The temporal distribution of the seismicity in the timeseries, as well as the true structural model, are not be known to any participating parties including MQS till the end of competition. We provide our internal tools such as event location codes, suite of background models, seismic phase travel times, in order to support researchers who are willing to use/improve our current methods. Following the deadline of our blind test in late 2017, we plan to combine all outcomes in an article with all participants as co-authors.

Current methods for detecting ethylene in plants

PubMed Central

Cristescu, Simona M.; Mandon, Julien; Arslanov, Denis; De Pessemier, Jérôme; Hermans, Christian; Harren, Frans J. M.

2013-01-01

Background In view of ethylene's critical developmental and physiological roles the gaseous hormone remains an active research topic for plant biologists. Progress has been made to understand the ethylene biosynthesis pathway and the mechanisms of perception and action. Still numerous questions need to be answered and findings to be validated. Monitoring gas production will very often complete the picture of any ethylene research topic. Therefore the search for suitable ethylene measuring methods for various plant samples either in the field, greenhouses, laboratories or storage facilities is strongly motivated. Scope This review presents an update of the current methods for ethylene monitoring in plants. It focuses on the three most-used methods – gas chromatography detection, electrochemical sensing and optical detection – and compares them in terms of sensitivity, selectivity, time response and price. Guidelines are provided for proper selection and application of the described sensor methodologies and some specific applications are illustrated of laser-based detector for monitoring ethylene given off by Arabidopsis thaliana upon various nutritional treatments. Conclusions Each method has its advantages and limitations. The choice for the suitable ethylene sensor needs careful consideration and is driven by the requirements for a specific application. PMID:23243188

Neuroimaging for psychotherapy research: Current trends

PubMed Central

WEINGARTEN, CAROL P.; STRAUMAN, TIMOTHY J.

2014-01-01

Objective This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research. Method We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research. Results We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive-compulsive disorder (OCD), and schizophrenia. Conclusions The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research. PMID:24527694

Determination of Charge-Carrier Mobility in Disordered Thin-Film Solar Cells as a Function of Current Density

NASA Astrophysics Data System (ADS)

Mäckel, Helmut; MacKenzie, Roderick C. I.

2018-03-01

Charge-carrier mobility is a fundamental material parameter, which plays an important role in determining solar-cell efficiency. The higher the mobility, the less time a charge carrier will spend in a device and the less likely it is that it will be lost to recombination. Despite the importance of this physical property, it is notoriously difficult to measure accurately in disordered thin-film solar cells under operating conditions. We, therefore, investigate a method previously proposed in the literature for the determination of mobility as a function of current density. The method is based on a simple analytical model that relates the mobility to carrier density and transport resistance. By revising the theoretical background of the method, we clearly demonstrate what type of mobility can be extracted (constant mobility or effective mobility of electrons and holes). We generalize the method to any combination of measurements that is able to determine the mean electron and hole carrier density, and the transport resistance at a given current density. We explore the robustness of the method by simulating typical organic solar-cell structures with a variety of physical properties, including unbalanced mobilities, unbalanced carrier densities, and for high or low carrier trapping rates. The simulations reveal that near VOC and JSC , the method fails due to the limitation of determining the transport resistance. However, away from these regions (and, importantly, around the maximum power point), the method can accurately determine charge-carrier mobility. In the presence of strong carrier trapping, the method overestimates the effective mobility due to an underestimation of the carrier density.

Application of Research on the Metallogenic Background in the Assessment of Mineral Resources Potentiality

NASA Astrophysics Data System (ADS)

Jia, D.; Feng, Y.; Liu, J.; Yao, X.; Zhang, Z.; Ye, T.

2017-12-01

1. Working BackgroundCurrent Status of Geological Prospecting: Detecting boundaries and bottoms, making ore search nearby; Seeing the stars, not seeing the Moon; Deep prospecting, undesirable results. The reasons of these problems are the regional metallogenic backgroud unclear and the metallogenic backgroud of the exploration regions unknown. Accordingly, Development and Research Center, CGS organized a geological setting research, in detail investigate metallogenic geological features and acquire mineralization information. 2. Technical SchemeCore research content is prediction elements of Metallogenic Structure. Adopt unified technical requirements from top to bottom, and technical route from bottom to top; Divide elements of mineral forecast and characteristics of geological structure into five elements for research and expression; Make full use of geophysical, geochemical and remote sensing inferences for the interpretation of macro information. After eight years the great project was completed. 3. Main AchievementsInnovation of basic maps compilation content of geological background, reinforce of geological structure data base of potentiality valuation. Preparation of geotectonic facies maps in different scales and professions, providing brand-new geologic background for potentiality assessment, promoting Chinese geotectonic research to the new height. Preparation of 3,375 geological structure thematic base maps of detecting working area in 6 kinds of prediction methods, providing base working maps, rock assemblage, structure of the protolith of geologic body / mineralization / ore controlling for mineral prediction of 25 ores. Enrichment and development of geotectonic facies analysis method, establishment of metallogenic background research thoughts and approach system for assessment of national mineral resources potentiality for the first time. 4. Application EffectOrientation——More and better results with less effort. Positioning——Have a definite object in view. Heart calm down——Confidence.

Improvement of Accuracy for Background Noise Estimation Method Based on TPE-AE

NASA Astrophysics Data System (ADS)

Itai, Akitoshi; Yasukawa, Hiroshi

This paper proposes a method of a background noise estimation based on the tensor product expansion with a median and a Monte carlo simulation. We have shown that a tensor product expansion with absolute error method is effective to estimate a background noise, however, a background noise might not be estimated by using conventional method properly. In this paper, it is shown that the estimate accuracy can be improved by using proposed methods.

The Making of Psychological Methods

PubMed Central

Harlow, Lisa L.

2017-01-01

Psychological Methods celebrated its 20-year anniversary recently, having published its first quarterly issue in March 1996. It seemed time to provide a brief overview of the history, the highlights over the years, and the current state of the journal, along with tips for submissions. The article is organized to discuss: (1) the background and development of the journal, (2) the top articles, authors and topics over the years, (3) an overview of the journal today, and (4) a summary of the features of successful articles that usually entail rigorous and novel methodology described in clear and understandable writing and that can be applied in meaningful and relevant areas of psychological research. PMID:28252997

A modal parameter extraction procedure applicable to linear time-invariant dynamic systems

NASA Technical Reports Server (NTRS)

Kurdila, A. J.; Craig, R. R., Jr.

1985-01-01

Modal analysis has emerged as a valuable tool in many phases of the engineering design process. Complex vibration and acoustic problems in new designs can often be remedied through use of the method. Moreover, the technique has been used to enhance the conceptual understanding of structures by serving to verify analytical models. A new modal parameter estimation procedure is presented. The technique is applicable to linear, time-invariant systems and accommodates multiple input excitations. In order to provide a background for the derivation of the method, some modal parameter extraction procedures currently in use are described. Key features implemented in the new technique are elaborated upon.

The status of augmented reality in laparoscopic surgery as of 2016.

PubMed

Bernhardt, Sylvain; Nicolau, Stéphane A; Soler, Luc; Doignon, Christophe

2017-04-01

This article establishes a comprehensive review of all the different methods proposed by the literature concerning augmented reality in intra-abdominal minimally invasive surgery (also known as laparoscopic surgery). A solid background of surgical augmented reality is first provided in order to support the survey. Then, the various methods of laparoscopic augmented reality as well as their key tasks are categorized in order to better grasp the current landscape of the field. Finally, the various issues gathered from these reviewed approaches are organized in order to outline the remaining challenges of augmented reality in laparoscopic surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

Measurement of the membrane potential in small cells using patch clamp methods

PubMed Central

Wilson, James R; Clark, Robert B; Banderali, Umberto

2011-01-01

The resting membrane potential, Em, of mammalian cells is a fundamental physiological parameter. Even small changes in Em can modulate excitability, contractility and rates of cell migration. At present accurate, reproducible measurements of Em and determination of its ionic basis remain significant challenges when patch clamp methods are applied to small cells. In this study, a mathematical model has been developed which incorporates many of the main biophysical principles which govern recordings of the resting potential of “small cells”. Such a prototypical cell (approx. capacitance, 6 pF; input resistance 5 GΩ) is representative of neonatal cardiac myocytes, and other cells in the cardiovascular system (endothelium, fibroblasts) and small cells in other tissues, e.g., bone (osteoclasts) articular joints (chondrocytes) and the pancreas (β cells). Two common experimental conditions have been examined: (1) when the background K+ conductance is linear; and (2) when this K+ conductance is highly nonlinear and shows pronounced inward rectification. In the case of a linear K+ conductance, the presence of a “leakage” current through the seal resistance between the cell membrane and the patch pipette always depolarizes Em. Our calculations confirm that accurate characterization of Em is possible when the seal resistance is at least five times larger than the input resistance of the targeted cell. Measurement of Em under conditions in which the main background current includes a markedly nonlinear K+ conductance (due to inward rectification) yields complex and somewhat counter-intuitive findings. In fact, there are at least two possible stable values of resting membrane potential for a cell when the nonlinear, inwardly rectifying K+ conductance interacts with the seal current. This type of bistable behavior has been reported in a variety of small mammalian cells, including those from the heart, endothelium, smooth muscle and bone. Our theoretical treatment of these two common experimental situations provides useful mechanistic insights, and suggests practical methods by which these significant limitations, and their impact, can be minimized. PMID:21829090

Infrared images target detection based on background modeling in the discrete cosine domain

NASA Astrophysics Data System (ADS)

Ye, Han; Pei, Jihong

2018-02-01

Background modeling is the critical technology to detect the moving target for video surveillance. Most background modeling techniques are aimed at land monitoring and operated in the spatial domain. A background establishment becomes difficult when the scene is a complex fluctuating sea surface. In this paper, the background stability and separability between target are analyzed deeply in the discrete cosine transform (DCT) domain, on this basis, we propose a background modeling method. The proposed method models each frequency point as a single Gaussian model to represent background, and the target is extracted by suppressing the background coefficients. Experimental results show that our approach can establish an accurate background model for seawater, and the detection results outperform other background modeling methods in the spatial domain.

Techniques for the correction of topographical effects in scanning Auger electron microscopy

NASA Technical Reports Server (NTRS)

Prutton, M.; Larson, L. A.; Poppa, H.

1983-01-01

A number of ratioing methods for correcting Auger images and linescans for topographical contrast are tested using anisotropically etched silicon substrates covered with Au or Ag. Thirteen well-defined angles of incidence are present on each polyhedron produced on the Si by this etching. If N1 electrons are counted at the energy of an Auger peak and N2 are counted in the background above the peak, then N1, N1 - N2, (N1 - N2)/(N1 + N2) are measured and compared as methods of eliminating topographical contrast. The latter method gives the best compensation but can be further improved by using a measurement of the sample absorption current. Various other improvements are discussed.

Background Adjusted Alignment-Free Dissimilarity Measures Improve the Detection of Horizontal Gene Transfer.

PubMed

Tang, Kujin; Lu, Yang Young; Sun, Fengzhu

2018-01-01

Horizontal gene transfer (HGT) plays an important role in the evolution of microbial organisms including bacteria. Alignment-free methods based on single genome compositional information have been used to detect HGT. Currently, Manhattan and Euclidean distances based on tetranucleotide frequencies are the most commonly used alignment-free dissimilarity measures to detect HGT. By testing on simulated bacterial sequences and real data sets with known horizontal transferred genomic regions, we found that more advanced alignment-free dissimilarity measures such as CVTree and [Formula: see text] that take into account the background Markov sequences can solve HGT detection problems with significantly improved performance. We also studied the influence of different factors such as evolutionary distance between host and donor sequences, size of sliding window, and host genome composition on the performances of alignment-free methods to detect HGT. Our study showed that alignment-free methods can predict HGT accurately when host and donor genomes are in different order levels. Among all methods, CVTree with word length of 3, [Formula: see text] with word length 3, Markov order 1 and [Formula: see text] with word length 4, Markov order 1 outperform others in terms of their highest F 1 -score and their robustness under the influence of different factors.

Human Body 3D Posture Estimation Using Significant Points and Two Cameras

PubMed Central

Juang, Chia-Feng; Chen, Teng-Chang; Du, Wei-Chin

2014-01-01

This paper proposes a three-dimensional (3D) human posture estimation system that locates 3D significant body points based on 2D body contours extracted from two cameras without using any depth sensors. The 3D significant body points that are located by this system include the head, the center of the body, the tips of the feet, the tips of the hands, the elbows, and the knees. First, a linear support vector machine- (SVM-) based segmentation method is proposed to distinguish the human body from the background in red, green, and blue (RGB) color space. The SVM-based segmentation method uses not only normalized color differences but also included angle between pixels in the current frame and the background in order to reduce shadow influence. After segmentation, 2D significant points in each of the two extracted images are located. A significant point volume matching (SPVM) method is then proposed to reconstruct the 3D significant body point locations by using 2D posture estimation results. Experimental results show that the proposed SVM-based segmentation method shows better performance than other gray level- and RGB-based segmentation approaches. This paper also shows the effectiveness of the 3D posture estimation results in different postures. PMID:24883422

Isotropy-violation diagnostics for B-mode polarization foregrounds to the Cosmic Microwave Background

NASA Astrophysics Data System (ADS)

Rotti, Aditya; Huffenberger, Kevin

2016-09-01

Isotropy-violation statistics can highlight polarized galactic foregrounds that contaminate primordial B-modes in the Cosmic Microwave Background (CMB). We propose a particular isotropy-violation test and apply it to polarized Planck 353 GHz data, constructing a map that indicates B-mode foreground dust power over the sky. We build our main isotropy test in harmonic space via the bipolar spherical harmonic basis, and our method helps us to identify the least-contaminated directions. By this measure, there are regions of low foreground in and around the BICEP field, near the South Galactic Pole, and in the Northern Galactic Hemisphere. There is also a possible foreground feature in the BICEP field. We compare our results to those based on the local power spectrum, which is computed on discs using a version of the method of Planck Int. XXX (2016). The discs method is closely related to our isotropy-violation diagnostic. We pay special care to the treatment of noise, including chance correlations with the foregrounds. Currently we use our isotropy tool to assess the cleanest portions of the sky, but in the future such methods will allow isotropy-based null tests for foreground contamination in maps purported to measure primordial B-modes, particularly in cases of limited frequency coverage.

Effect of Pulse Parameters on Weld Quality in Pulsed Gas Metal Arc Welding: A Review

NASA Astrophysics Data System (ADS)

Pal, Kamal; Pal, Surjya K.

2011-08-01

The weld quality comprises bead geometry and its microstructure, which influence the mechanical properties of the weld. The coarse-grained weld microstructure, higher heat-affected zone, and lower penetration together with higher reinforcement reduce the weld service life in continuous mode gas metal arc welding (GMAW). Pulsed GMAW (P-GMAW) is an alternative method providing a better way for overcoming these afore mentioned problems. It uses a higher peak current to allow one molten droplet per pulse, and a lower background current to maintain the arc stability. Current pulsing refines the grains in weld fusion zone with increasing depth of penetration due to arc oscillations. Optimum weld joint characteristics can be achieved by controlling the pulse parameters. The process is versatile and easily automated. This brief review illustrates the effect of pulse parameters on weld quality.

Preliminary scaling laws for plasma current, ion kinetic temperature, and plasma number density in the NASA Lewis bumpy torus plasma

NASA Technical Reports Server (NTRS)

Roth, J. R.

1976-01-01

Parametric variation of independent variables which may affect the characteristics of bumpy torus plasma have identified those which have a significant effect on the plasma current, ion kinetic temperature, and plasma number density, and those which do not. Empirical power law correlations of the plasma current, and the ion kinetic temperature and number density were obtained as functions of potential applied to the midplane electrode rings, the background neutral gas pressure, and the magnetic field strength. Additional parameters studied included the type of gas, the polarity of the midplane electrode rings, the mode of plasma operation, and the method of measuring the plasma number density. No significant departures from the scaling laws appear to occur at the highest ion kinetic temperatures or number densities obtained to date.

Effect of Background Pressure on the Performance and Plume of the HiVHAc Hall Thruster

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Kamhawi, Hani; Haag, Thomas

2013-01-01

During the Single String Integration Test of the NASA HiVHAc Hall thruster, a number of plasma diagnostics were implemented to study the effect of varying facility background pressure on thruster operation. These diagnostics include thrust stand, Faraday probe, ExB probe, and retarding potential analyzer. The test results indicated a rise in thrust and discharge current with background pressure. There was also a decrease in ion energy per charge, an increase in multiply-charged species production, a decrease in plume divergence, and a decrease in ion beam current with increasing background pressure. A simplified ingestion model was applied to determine the maximum acceptable background pressure for thrust measurement. The maximum acceptable ingestion percentage was found to be around 1%. Examination of the diagnostics results suggest the ionization and acceleration zones of the thruster were shifting upstream with increasing background pressure.

WebArray: an online platform for microarray data analysis

PubMed Central

Xia, Xiaoqin; McClelland, Michael; Wang, Yipeng

2005-01-01

Background Many cutting-edge microarray analysis tools and algorithms, including commonly used limma and affy packages in Bioconductor, need sophisticated knowledge of mathematics, statistics and computer skills for implementation. Commercially available software can provide a user-friendly interface at considerable cost. To facilitate the use of these tools for microarray data analysis on an open platform we developed an online microarray data analysis platform, WebArray, for bench biologists to utilize these tools to explore data from single/dual color microarray experiments. Results The currently implemented functions were based on limma and affy package from Bioconductor, the spacings LOESS histogram (SPLOSH) method, PCA-assisted normalization method and genome mapping method. WebArray incorporates these packages and provides a user-friendly interface for accessing a wide range of key functions of limma and others, such as spot quality weight, background correction, graphical plotting, normalization, linear modeling, empirical bayes statistical analysis, false discovery rate (FDR) estimation, chromosomal mapping for genome comparison. Conclusion WebArray offers a convenient platform for bench biologists to access several cutting-edge microarray data analysis tools. The website is freely available at . It runs on a Linux server with Apache and MySQL. PMID:16371165

The Low Energy Neutrino Spectrometry (LENS) Experiment and LENS prototype, μLENS, initial results

NASA Astrophysics Data System (ADS)

Yokley, Zachary

2012-03-01

LENS is a low energy solar neutrino detector that will measure the solar neutrino spectrum above 115 keV, >95% of the solar neutrino flux, in real time. The fundamental neutrino reaction in LENS is charged-current based capture on 115-In detected in a liquid scintillator medium. The reaction yields the prompt emission of an electron and the delayed emission of 2 gamma rays that serve as a time & space coincidence tag. Sufficient spatial resolution is used to exploit this signature and suppress background, particularly due to 115-In beta decay. A novel design of optical segmentation (Scintillation Lattice or SL) channels the signal light along the three primary axes. The channeling is achieved via total internal reflection by suitable low index gaps in the segmentation. The spatial resolution of a nuclear event is obtained digitally, much more precisely than possible by common time of flight methods. Advanced Geant4 analysis methods have been developed to suppress adequately the severe background due to 115-In beta decay, achieving at the same time high detection efficiency. LENS physics and detection methods along with initial results characterizing light transport in the as built μLENS prototype will be presented.

A prospective cohort study of disability pension due to mental diagnoses: the importance of health factors and behaviors

PubMed Central

2013-01-01

Background Previous studies have found associations between various health factors and behaviors and mental disorders. However, knowledge of such associations with disability pension (DP) due to mental diagnoses is scarce. Moreover, the influence of familial factors (genetics and family background) on the associations are mainly unknown. The aim of the study was to investigate associations between health factors and behaviors and future DP due to mental diagnoses in a twin cohort, accounting for familial confounding. Methods A prospective cohort study of Swedish twins (N=28 613), including survey data and national register data on DP and other background factors was conducted. Cox proportional hazards regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for the whole twin cohort, and for discordant twin pairs. Results During follow-up 1998–2008 (median 10 years), 2.2% of the cohort was granted a DP with a mental diagnosis. In the fully adjusted analyses of the whole cohort, the associations of poor or moderate self-rated health (SRH), under- or overweight, former or current tobacco use, or being an abstainer from alcohol were significantly associated with risk of DP due to mental diagnoses. Analyses of discordant twin pairs confirmed all these associations, except for current tobacco use, being independent from familial confounding. Exclusion of individuals with current or previous depression or anxiety at baseline did not influence the associations found. Conclusions Poor or moderate SRH, under- or overweight, former tobacco use or being an abstainer from alcohol seem to be strong direct predictors of DP due to mental diagnoses, independently of several confounders of this study, including familial factors. PMID:23816331

Spin Currents and Ferromagnetic Resonance in Magnetic Thin Films

NASA Astrophysics Data System (ADS)

Ellsworth, David

Spin currents represent a new and exciting phenomenon. There is both a wealth of new physics to be discovered and understood, and many appealing devices which may result from this area of research. To fully realize the potential of this discipline it is necessary to develop new methods for realizing spin currents and explore new materials which may be suitable for spin current applications. Spin currents are an inherently dynamic phenomenon involving the transfer of angular momentum within and between different thin films. In order to understand and optimize such devices the dynamics of magnetization must be determined. This dissertation reports on novel approaches for spin current generation utilizing the magnetic insulators yttrium iron garnet (YIG) and M-type barium hexagonal ferrite (BaM). First, the light-induced spin Seebeck effect is reported for the first time in YIG. Additionally, the first measurement of the spin Seebeck effect without an external magnetic field is demonstrated. To accomplish this the self-biased BaM thin films are utilized. Second, a new method for the generation of spin currents is presented: the photo-spin-voltaic effect. In this new phenomenon, a spin current may be generated by photons in a non-magnetic metal that is in close proximity to a magnetic insulator. On exposure to light, there occurs a light induced, spin-dependent excitation of electrons in a few platinum layers near the metal/magnetic insulator interface. This excitation gives rise to a pure spin current which flows in the metal. This new effect is explored in detail and extensive measurements are carried out to confirm the photonic origin of the photo-spin-voltaic effect and exclude competing effects. In addition to the spin current measurements, magnetization dynamics were probed in thin films using ferromagnetic resonance (FMR). In order to determine the optimal material configuration for magnetic recording write heads, FMR measurements were used to perform damping studies on a set of FeCo samples with different numbers of lamination layers. The use of lamination layers has the potential to tune the damping in such films, while leaving the other magnetic properties unchanged. Finally, the sensitivity of the vector network analyzer FMR technique was improved. The use of field modulation and lock-in detection, along with the background subtraction of a Mach-Zehnder microwave interferometer working as a notch filter, is able to increase the sensitivity and lower the background noise of this measurement technique. This improved system opens the possibility of probing previously difficult samples with extremely low signals.

A Spectral Algorithm for Solving the Relativistic Vlasov-Maxwell Equations

NASA Technical Reports Server (NTRS)

Shebalin, John V.

2001-01-01

A spectral method algorithm is developed for the numerical solution of the full six-dimensional Vlasov-Maxwell system of equations. Here, the focus is on the electron distribution function, with positive ions providing a constant background. The algorithm consists of a Jacobi polynomial-spherical harmonic formulation in velocity space and a trigonometric formulation in position space. A transform procedure is used to evaluate nonlinear terms. The algorithm is suitable for performing moderate resolution simulations on currently available supercomputers for both scientific and engineering applications.

Note: thermal imaging enhancement algorithm for gas turbine aerothermal characterization.

PubMed

Beer, S K; Lawson, S A

2013-08-01

An algorithm was developed to convert radiation intensity images acquired using a black and white CCD camera to thermal images without requiring knowledge of incident background radiation. This unique infrared (IR) thermography method was developed to determine aerothermal characteristics of advanced cooling concepts for gas turbine cooling application. Compared to IR imaging systems traditionally used for gas turbine temperature monitoring, the system developed for the current study is relatively inexpensive and does not require calibration with surface mounted thermocouples.

Phase-ambiguity resolution for QPSK modulation systems. Part 1: A review

NASA Technical Reports Server (NTRS)

Nguyen, Tien Manh

1989-01-01

Part 1 reviews the current phase-ambiguity resolution techniques for QPSK coherent modulation systems. Here, those known and published methods of resolving phase ambiguity for QPSK with and without Forward-Error-Correcting (FEC) are discussed. The necessary background is provided for a complete understanding of the second part where a new technique will be discussed. An appropriate technique to the Consultative Committee for Space Data Systems (CCSDS) is recommended for consideration in future standards on phase-ambiguity resolution for QPSK coherent modulation systems.

Sodium MRI: Methods and applications

PubMed Central

Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

2014-01-01

Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

Tsunami Detection by High-Frequency Radar Beyond the Continental Shelf

NASA Astrophysics Data System (ADS)

Grilli, Stéphan T.; Grosdidier, Samuel; Guérin, Charles-Antoine

2016-12-01

Where coastal tsunami hazard is governed by near-field sources, such as submarine mass failures or meteo-tsunamis, tsunami propagation times may be too small for a detection based on deep or shallow water buoys. To offer sufficient warning time, it has been proposed to implement early warning systems relying on high-frequency (HF) radar remote sensing, that can provide a dense spatial coverage as far offshore as 200-300 km (e.g., for Diginext Ltd.'s Stradivarius radar). Shore-based HF radars have been used to measure nearshore currents (e.g., CODAR SeaSonde® system; http://www.codar.com/), by inverting the Doppler spectral shifts, these cause on ocean waves at the Bragg frequency. Both modeling work and an analysis of radar data following the Tohoku 2011 tsunami, have shown that, given proper detection algorithms, such radars could be used to detect tsunami-induced currents and issue a warning. However, long wave physics is such that tsunami currents will only rise above noise and background currents (i.e., be at least 10-15 cm/s), and become detectable, in fairly shallow water which would limit the direct detection of tsunami currents by HF radar to nearshore areas, unless there is a very wide shallow shelf. Here, we use numerical simulations of both HF radar remote sensing and tsunami propagation to develop and validate a new type of tsunami detection algorithm that does not have these limitations. To simulate the radar backscattered signal, we develop a numerical model including second-order effects in both wind waves and radar signal, with the wave angular frequency being modulated by a time-varying surface current, combining tsunami and background currents. In each "radar cell", the model represents wind waves with random phases and amplitudes extracted from a specified (wind speed dependent) energy density frequency spectrum, and includes effects of random environmental noise and background current; phases, noise, and background current are extracted from independent Gaussian distributions. The principle of the new algorithm is to compute correlations of HF radar signals measured/simulated in many pairs of distant "cells" located along the same tsunami wave ray, shifted in time by the tsunami propagation time between these cell locations; both rays and travel time are easily obtained as a function of long wave phase speed and local bathymetry. It is expected that, in the presence of a tsunami current, correlations computed as a function of range and an additional time lag will show a narrow elevated peak near the zero time lag, whereas no pattern in correlation will be observed in the absence of a tsunami current; this is because surface waves and background current are uncorrelated between pair of cells, particularly when time-shifted by the long-wave propagation time. This change in correlation pattern can be used as a threshold for tsunami detection. To validate the algorithm, we first identify key features of tsunami propagation in the Western Mediterranean Basin, where Stradivarius is deployed, by way of direct numerical simulations with a long wave model. Then, for the purpose of validating the algorithm we only model HF radar detection for idealized tsunami wave trains and bathymetry, but verify that such idealized case studies capture well the salient tsunami wave physics. Results show that, in the presence of strong background currents, the proposed method still allows detecting a tsunami with currents as low as 0.05 m/s, whereas a standard direct inversion based on radar signal Doppler spectra fails to reproduce tsunami currents weaker than 0.15-0.2 m/s. Hence, the new algorithm allows detecting tsunami arrival in deeper water, beyond the shelf and further away from the coast, and providing an early warning. Because the standard detection of tsunami currents works well at short range, we envision that, in a field situation, the new algorithm could complement the standard approach of direct near-field detection by providing a warning that a tsunami is approaching, at larger range and in greater depth. This warning would then be confirmed at shorter range by a direct inversion of tsunami currents, from which the magnitude of the tsunami would also estimated. Hence, both algorithms would be complementary. In future work, the algorithm will be applied to actual tsunami case studies performed using a state-of-the-art long wave model, such as briefly presented here in the Mediterranean Basin.

3D Inversion of Natural Source Electromagnetics

NASA Astrophysics Data System (ADS)

Holtham, E. M.; Oldenburg, D. W.

2010-12-01

The superior depth of investigation of natural source electromagnetic techniques makes these methods excellent candidates for crustal studies as well as for mining and hydrocarbon exploration. The traditional natural source method, the magnetotelluric (MT) technique, has practical limitations because the surveys are costly and time consuming due to the labor intensive nature of ground based surveys. In an effort to continue to use the penetration advantage of natural sources, it has long been recognized that tipper data, the ratio of the local vertical magnetic field to the horizontal magnetic field, provide information about 3D electrical conductivity structure. It was this understanding that prompted the development of AFMAG (Audio Frequency Magnetics) and recently the new airborne Z-Axis Tipper Electromagnetic Technique (ZTEM). In ZTEM, the vertical component of the magnetic field is recorded above the entire survey area, while the horizontal fields are recorded at a ground-based reference station. MT processing techniques yield frequency domain transfer functions typically between 30-720 Hz that relate the vertical fields over the survey area to the horizontal fields at the reference station. The result is a cost effective procedure for collecting natural source EM data and for finding large scale targets at moderate depths. It is well known however that 1D layered structures produce zero vertical magnetic fields and thus ZTEM data cannot recover such background conductivities. This is in sharp contrast to the MT technique where electric fields are measured and a 1D background conductivity can be recovered from the off diagonal elements of the impedance tensor. While 1D models produce no vertical fields, two and three dimensional structures will produce anomalous currents and a ZTEM response. For such models the background conductivity structure does affect the data. In general however, the ZTEM data have weak sensitivity to the background conductivity and while we show that it is possible to obtain the background structure by inverting the ZTEM data alone, it is desirable to obtain robust background conductivity information from other sources. This information could come from a priori geologic and petrophysical information or from additional geophysical data such as MT. To counter the costly nature of large MT surveys and the limited sensitivity of the ZTEM technique to the background conductivity we show that an effective method is to collect and invert both MT and ZTEM data. A sparse MT survey grid can gather information about the background conductivity and deep structures while keeping the survey costs affordable. Higher spatial resolution at moderate depths can be obtained by flying multiple lines of ZTEM data.

Performance, Facility Pressure Effects, and Stability Characterization Tests of NASA's Hall Effect Rocket with Magnetic Shielding Thruster

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Yim, John; Herman, Daniel; Williams, George; Gilland, James; Peterson, Peter; Hofer, Richard; Mikellides, Ioannis

2016-01-01

NASAs Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) Hall thruster has been the subject of extensive technology maturation in preparation for flight system development. Part of the technology maturation effort included experimental evaluation of the TDU-1 thruster with conducting and dielectric front pole cover materials in two different electrical configurations. A graphite front pole cover thruster configuration with the thruster body electrically tied to cathode and an alumina front pole cover thruster configuration with the thruster body floating were evaluated. Both configurations were also evaluated at different facility background pressure conditions to evaluate background pressure effects on thruster operation. Performance characterization tests found that higher thruster performance was attained with the graphite front pole cover configuration with the thruster electrically tied to cathode. A total thrust efficiency of 68 and a total specific impulse of 2,820 s was demonstrated at a discharge voltage of 600 V and a discharge power of 12.5 kW. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations and with maps of the current-voltage-magnetic field (IVB). Analysis of TDU-1 discharge current waveforms found that lower normalized discharge current peak-to-peak and root mean square magnitudes were attained when the thruster was electrically floated with alumina front pole covers. Background pressure effects characterization tests indicated that the thruster performance and stability was mostly invariant to changes in the facility background pressure for vacuum chamber pressure below 110-5 Torr-Xe (for thruster flow rate above 8 mgs). Power spectral density analysis of the discharge current waveform showed that increasing the vacuum chamber background pressure resulted in a higher discharge current dominant frequency. Finally the IVB maps of the TDU-1 thruster taken at elevated magnetic fields indicated that the discharge current became more oscillatory with increased facility background pressure at lower thruster mass flow rates, where thruster operation at higher flow rates resulted in less change to the thrusters IVB characteristics.

Exploring Patient Values in Medical Decision Making: A Qualitative Study

PubMed Central

Lee, Yew Kong; Low, Wah Yun; Ng, Chirk Jenn

2013-01-01

Background Patient decisions are influenced by their personal values. However, there is a lack of clarity and attention on the concept of patient values in the clinical context despite clear emphasis on patient values in evidence-based medicine and shared decision making. The aim of the study was to explore the concept of patient values in the context of making decisions about insulin initiation among people with type 2 diabetes. Methods and Findings We conducted individual in-depth interviews with people with type 2 diabetes who were making decisions about insulin treatment. Participants were selected purposively to achieve maximum variation. A semi-structured topic guide was used to guide the interviews which were audio-recorded and analysed using a thematic approach. We interviewed 21 participants between January 2011 and March 2012. The age range of participants was 28–67 years old. Our sample comprised 9 women and 12 men. Three main themes, ‘treatment-specific values’, ‘life goals and philosophies’, and ‘personal and social background’, emerged from the analysis. The patients reported a variety of insulin-specific values, which were negative and/or positive beliefs about insulin. They framed insulin according to their priorities and philosophies in life. Patients’ decisions were influenced by sociocultural (e.g. religious background) and personal backgrounds (e.g. family situations). Conclusions This study highlighted the need for expanding the current concept of patient values in medical decision making. Clinicians should address more than just values related to treatment options. Patient values should include patients’ priorities, life philosophy and their background. Current decision support tools, such as patient decision aids, should consider these new dimensions when clarifying patient values. PMID:24282518

A State-of-the-Art Review: Personalization of Tinnitus Sound Therapy.

PubMed

Searchfield, Grant D; Durai, Mithila; Linford, Tania

2017-01-01

Background: There are several established, and an increasing number of putative, therapies using sound to treat tinnitus. There appear to be few guidelines for sound therapy selection and application. Aim: To review current approaches to personalizing sound therapy for tinnitus. Methods: A "state-of-the-art" review (Grant and Booth, 2009) was undertaken to answer the question: how do current sound-based therapies for tinnitus adjust for tinnitus heterogeneity? Scopus, Google Scholar, Embase and PubMed were searched for the 10-year period 2006-2016. The search strategy used the following key words: "tinnitus" AND "sound" AND "therapy" AND "guidelines" OR "personalized" OR "customized" OR "individual" OR "questionnaire" OR "selection." The results of the review were cataloged and organized into themes. Results: In total 165 articles were reviewed in full, 83 contained sufficient details to contribute to answering the study question. The key themes identified were hearing compensation, pitched-match therapy, maskability, reaction to sound and psychosocial factors. Although many therapies mentioned customization, few could be classified as being personalized. Several psychoacoustic and questionnaire-based methods for assisting treatment selection were identified. Conclusions: Assessment methods are available to assist clinicians to personalize sound-therapy and empower patients to be active in therapy decision-making. Most current therapies are modified using only one characteristic of the individual and/or their tinnitus.

Implementation of a chemical background method (OH-CHEM) for measurements of OH using the Leeds FAGE instrument: Characterisation and observations from a coastal location

NASA Astrophysics Data System (ADS)

Woodward-Massey, R.; Cryer, D. R.; Whalley, L. K.; Ingham, T.; Seakins, P. W.; Heard, D. E.; Stimpson, L. M.

2015-12-01

The removal of pollutants and greenhouse gases in the troposphere is dominated by reactions with the hydroxyl radical (OH), which is closely coupled to the hydroperoxy radical (HO2). Comparisons of the levels of OH and HO2 observed during field campaigns to the results of detailed chemical box models serve as a vital tool to assess our understanding of the underlying chemical mechanisms involved in tropospheric oxidation. Recent measurements of OH and HO2 radicals are significantly higher than those predicted by models for some instruments measuring in certain environments, especially those influenced by high emissions of biogenic compounds such as isoprene, prompting intense laboratory research to account for such discrepancies. While current chemical mechanisms are likely incomplete, it is also possible that, at least in part, these elevated radical observations have been influenced by instrumental biases from interfering species. Recent studies have suggested that fluorescence assay by gas expansion (FAGE) instruments may be susceptible to an unknown interference in the measurement of OH. This hypothesis can be tested through the implementation of an alternative method to determine the OH background signal, whereby OH is removed by the addition of a chemical scavenger prior to sampling by FAGE. The Leeds FAGE instrument was modified to facilitate this method by the construction of an inlet pre-injector (IPI), where OH is removed through reaction with propane. The modified Leeds FAGE instrument was deployed at a coastal location in southeast England during summer 2015 as part of the ICOZA (Integrated Chemistry of OZone in the Atmosphere) project. Measurements of OH made using both background methods will be presented, alongside results from laboratory characterisation experiments and details of the IPI design.

Optical Design Considerations for Efficient Light Collection from Liquid Scintillation Counters

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

Bernacki, Bruce E.; Douglas, Matthew; Erchinger, Jennifer L.

2015-01-01

Liquid scintillation counters measure charged particle-emitting radioactive isotopes and are used for environmental studies, nuclear chemistry, and life science. Alpha and beta emissions arising from the material under study interact with the scintillation cocktail to produce light. The prototypical liquid scintillation counter employs low-level photon-counting detectors to measure the arrival of the scintillation light produced as a result of the dissolved material under study interacting with the scintillation cocktail. For reliable operation the counting instrument must convey the scintillation light to the detectors efficiently and predictably. Current best practices employ the use of two or more detectors for coincidence processingmore » to discriminate true scintillation events from background events due to instrumental effects such as photomultiplier tube dark rates, tube flashing, or other light emission not generated in the scintillation cocktail vial. In low background liquid scintillation counters additional attention is paid to shielding the scintillation cocktail from naturally occurring radioactive material (NORM) present in the laboratory and within the instruments construction materials. Low background design is generally at odds with optimal light collection. This study presents the evolution of a light collection design for liquid scintillation counting in a low background shield. The basic approach to achieve both good light collection and a low background measurement is described. The baseline signals arising from the scintillation vial are modeled and methods to efficiently collect scintillation light are presented as part of the development of a customized low-background, high sensitivity liquid scintillation counting system.« less

Investigating Galactic Structure with COBE/DIRBE and Simulation

NASA Technical Reports Server (NTRS)

Cohen, Martin

1999-01-01

In this work I applied the current version of the SKY model of the point source sky to the interpretation of the diffuse all-sky emission observed by COBE/DIRBE (Cosmic Background Explorer Satellite/Diffuse Infrared Background Experiment). The goal was to refine the SKY model using the all-sky DIRBE maps of the Galaxy, in order that a search could be made for an isotropic cosmic background."Faint Source Model" [FSM] was constructed to remove Galactic fore ground stars from the ZSMA products. The FSM mimics SKY version 1 but it was inadequate to seek cosmic background emission because of the sizeable residual emission in the ZSMA products after this starlight subtraction. At this point I can only support that such models are currently inadequate to reveal a cosmic background. Even SKY5 yields the same disappointing result.

Probing interferometric parallax with interplanetary spacecraft

NASA Astrophysics Data System (ADS)

Rodeghiero, G.; Gini, F.; Marchili, N.; Jain, P.; Ralston, J. P.; Dallacasa, D.; Naletto, G.; Possenti, A.; Barbieri, C.; Franceschini, A.; Zampieri, L.

2017-07-01

We describe an experimental scenario for testing a novel method to measure distance and proper motion of astronomical sources. The method is based on multi-epoch observations of amplitude or intensity correlations between separate receiving systems. This technique is called Interferometric Parallax, and efficiently exploits phase information that has traditionally been overlooked. The test case we discuss combines amplitude correlations of signals from deep space interplanetary spacecraft with those from distant galactic and extragalactic radio sources with the goal of estimating the interplanetary spacecraft distance. Interferometric parallax relies on the detection of wavefront curvature effects in signals collected by pairs of separate receiving systems. The method shows promising potentialities over current techniques when the target is unresolved from the background reference sources. Developments in this field might lead to the construction of an independent, geometrical cosmic distance ladder using a dedicated project and future generation instruments. We present a conceptual overview supported by numerical estimates of its performances applied to a spacecraft orbiting the Solar System. Simulations support the feasibility of measurements with a simple and time-saving observational scheme using current facilities.

Large Aircraft Robotic Paint Stripping (LARPS) system and the high pressure water process

NASA Astrophysics Data System (ADS)

See, David W.; Hofacker, Scott A.; Stone, M. Anthony; Harbaugh, Darcy

1993-03-01

The aircraft maintenance industry is beset by new Environmental Protection Agency (EPA) guidelines on air emissions, Occupational Safety and Health Administration (OSHA) standards, dwindling labor markets, Federal Aviation Administration (FAA) safety guidelines, and increased operating costs. In light of these factors, the USAF's Wright Laboratory Manufacturing Technology Directorate and the Aircraft Division of the Oklahoma City Air Logistics Center initiated a MANTECH/REPTECH effort to automate an alternate paint removal method and eliminate the current manual methylene chloride chemical stripping methods. This paper presents some of the background and history of the LARPS program, describes the LARPS system, documents the projected operational flow, quantifies some of the projected system benefits and describes the High Pressure Water Stripping Process. Certification of an alternative paint removal method to replace the current chemical process is being performed in two phases: Process Optimization and Process Validation. This paper also presents the results of the Process Optimization for metal substrates. Data on the coating removal rate, residual stresses, surface roughness, preliminary process envelopes, and technical plans for process Validation Testing will be discussed.

Comparative study of the effectiveness and limitations of current methods for detecting sequence coevolution.

PubMed

Mao, Wenzhi; Kaya, Cihan; Dutta, Anindita; Horovitz, Amnon; Bahar, Ivet

2015-06-15

With rapid accumulation of sequence data on several species, extracting rational and systematic information from multiple sequence alignments (MSAs) is becoming increasingly important. Currently, there is a plethora of computational methods for investigating coupled evolutionary changes in pairs of positions along the amino acid sequence, and making inferences on structure and function. Yet, the significance of coevolution signals remains to be established. Also, a large number of false positives (FPs) arise from insufficient MSA size, phylogenetic background and indirect couplings. Here, a set of 16 pairs of non-interacting proteins is thoroughly examined to assess the effectiveness and limitations of different methods. The analysis shows that recent computationally expensive methods designed to remove biases from indirect couplings outperform others in detecting tertiary structural contacts as well as eliminating intermolecular FPs; whereas traditional methods such as mutual information benefit from refinements such as shuffling, while being highly efficient. Computations repeated with 2,330 pairs of protein families from the Negatome database corroborated these results. Finally, using a training dataset of 162 families of proteins, we propose a combined method that outperforms existing individual methods. Overall, the study provides simple guidelines towards the choice of suitable methods and strategies based on available MSA size and computing resources. Software is freely available through the Evol component of ProDy API. © The Author 2015. Published by Oxford University Press.

New developments in transit noise and vibration criteria

NASA Astrophysics Data System (ADS)

Hanson, Carl E.

2004-05-01

Federal Transit Administration (FTA) noise and vibration impact criteria were developed in the early 1990's. Noise criteria are ambient-based, developed from the Schultz curve and fundamental research performed by the U.S. Environmental Protection Agency in the 1970's. Vibration criteria are single-value rms vibration velocity levels. After 10 years of experience applying the criteria in assessments of new transit projects throughout the United States, FTA is updating its methods. Approach to assessment of new projects in existing high-noise environments will be clarified. Method for assessing noise impacts due to horn blowing at grade crossings will be provided. Vibration criteria will be expanded to include spectral information. This paper summarizes the background of the current criteria, discusses examples where existing methods are lacking, and describes the planned remedies to improve criteria and methods.

The Role of Stem Cells in the Treatment of Cerebral Palsy: a Review.

PubMed

Kiasatdolatabadi, Anahita; Lotfibakhshaiesh, Nasrin; Yazdankhah, Meysam; Ebrahimi-Barough, Somayeh; Jafarabadi, Mina; Ai, Arman; Sadroddiny, Esmaeil; Ai, Jafar

2017-09-01

Cerebral palsy (CP) is a neuromuscular disease due to injury in the infant's brain. The CP disorder causes many neurologic dysfunctions in the patient. Various treatment methods have been used for the management of CP disorder. However, there has been no absolute cure for this condition. Furthermore, some of the procedures which are currently used for relief of symptoms in CP cause discomfort or side effects in the patient. Recently, stem cell therapy has attracted a huge interest as a new therapeutic method for treatment of CP. Several investigations in animal and human with CP have demonstrated positive potential of stem cell transplantation for the treatment of CP disorder. The ultimate goal of this therapeutic method is to harness the regenerative capacity of the stem cells causing a formation of new tissues to replace the damaged tissue. During the recent years, there have been many investigations on stem cell therapy. However, there are still many unclear issues regarding this method and high effort is needed to create a technology as a perfect treatment. This review will discuss the scientific background of stem cell therapy for cerebral palsy including evidences from current clinical trials.

Electromagnetic radiation due to naked singularity formation in self-similar gravitational collapse

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

Mitsuda, Eiji; Yoshino, Hirotaka; Tomimatsu, Akira

Dynamical evolution of test fields in background geometry with a naked singularity is an important problem relevant to the Cauchy horizon instability and the observational signatures different from black hole formation. In this paper we study electromagnetic perturbations generated by a given current distribution in collapsing matter under a spherically symmetric self-similar background. Using the Green's function method, we construct the formula to evaluate the outgoing energy flux observed at the future null infinity. The contributions from 'quasinormal' modes of the self-similar system as well as 'high-frequency' waves are clarified. We find a characteristic power-law time evolution of the outgoingmore » energy flux which appears just before naked singularity formation and give the criteria as to whether or not the outgoing energy flux diverges at the future Cauchy horizon.« less

A fully automatable enzymatic method for DNA extraction from plant tissues

PubMed Central

Manen, Jean-François; Sinitsyna, Olga; Aeschbach, Lorène; Markov, Alexander V; Sinitsyn, Arkady

2005-01-01

Background DNA extraction from plant tissues, unlike DNA isolation from mammalian tissues, remains difficult due to the presence of a rigid cell wall around the plant cells. Currently used methods inevitably require a laborious mechanical grinding step, necessary to disrupt the cell wall for the release of DNA. Results Using a cocktail of different carbohydrases, a method was developed that enables a complete digestion of the plant cell walls and subsequent DNA release. Optimized conditions for the digestion reaction minimize DNA shearing and digestion, and maximize DNA release from the plant cell. The method gave good results in 125 of the 156 tested species. Conclusion In combination with conventional DNA isolation techniques, the new enzymatic method allows to obtain high-yield, high-molecular weight DNA, which can be used for many applications, including genome characterization by AFLP, RAPD and SSR. Automation of the protocol (from leaf disks to DNA) is possible with existing workstations. PMID:16269076

Characterization of polymer, DNA-based, and silk thin film resistivities and of DNA-based films prepared for enhanced electrical conductivity

NASA Astrophysics Data System (ADS)

Yaney, Perry P.; Ouchen, Fahima; Grote, James G.

2009-08-01

DC resistivity studies were carried out on biopolymer films of DNA-CTMA and silk fibroin, and on selected traditional polymer films, including PMMA and APC. Films of DNA-CTMA versus molecular weight and with conductive dopants PCBM, BAYTRON P and ammonium tetrachloroplatinate are reported. The films were spin coated on glass slides configured for measurements of volume dc resistance. The measurements used the alternating polarity method to record the applied voltage-dependent current independent of charging and background currents. The Arrhenius equation plus a constant was fitted to the conductivity versus temperature data of the polymers and the non-doped DNA-based biopolymers with activation energies ranging from 0.8 to 1.4 eV.

Microwave beamed power technology improvement. [magnetrons and slotted waveguide arrays

NASA Technical Reports Server (NTRS)

Brown, W. C.

1980-01-01

The magnetron directional amplifier was tested for (1) phase shift and power output as a function of gain, anode current, and anode voltage, (2) background noise and harmonics in the output, (3) long life potential of the magnetron cathode, and (4) high operational efficiency. Examples of results were an adequate range of current and voltage over which 20 dB of amplification could be obtained, spectral noise density 155 dB below the carrier, 81.7% overall efficiency, and potential cathode life of 50 years in a design for solar power satellite use. A fabrication method was used to fabricate a 64 slot, 30 in square slotted waveguide array module from 0.020 in thick aluminum sheet. The test results on the array are discussed.

Identification of pathogen genomic variants through an integrated pipeline

PubMed Central

2014-01-01

Background Whole-genome sequencing represents a powerful experimental tool for pathogen research. We present methods for the analysis of small eukaryotic genomes, including a streamlined system (called Platypus) for finding single nucleotide and copy number variants as well as recombination events. Results We have validated our pipeline using four sets of Plasmodium falciparum drug resistant data containing 26 clones from 3D7 and Dd2 background strains, identifying an average of 11 single nucleotide variants per clone. We also identify 8 copy number variants with contributions to resistance, and report for the first time that all analyzed amplification events are in tandem. Conclusions The Platypus pipeline provides malaria researchers with a powerful tool to analyze short read sequencing data. It provides an accurate way to detect SNVs using known software packages, and a novel methodology for detection of CNVs, though it does not currently support detection of small indels. We have validated that the pipeline detects known SNVs in a variety of samples while filtering out spurious data. We bundle the methods into a freely available package. PMID:24589256

Development of Yellow Sand Image Products Using Infrared Brightness Temperature Difference Method

NASA Astrophysics Data System (ADS)

Ha, J.; Kim, J.; Kwak, M.; Ha, K.

2007-12-01

A technique for detection of airborne yellow sand dust using meteorological satellite has been developed from various bands from ultraviolet to infrared channels. Among them, Infrared (IR) channels have an advantage of detecting aerosols over high reflecting surface as well as during nighttime. There had been suggestion of using brightness temperature difference (BTD) between 11 and 12¥ìm. We have found that the technique is highly depends on surface temperature, emissivity, and zenith angle, which results in changing the threshold of BTD. In order to overcome these problems, we have constructed the background brightness temperature threshold of BTD and then aerosol index (AI) has been determined from subtracting the background threshold from BTD of our interested scene. Along with this, we utilized high temporal coverage of geostationary satellite, MTSAT, to improve the reliability of the determined AI signal. The products have been evaluated by comparing the forecasted wind field with the movement fiend of AI. The statistical score test illustrates that this newly developed algorithm produces a promising result for detecting mineral dust by reducing the errors with respect to the current BTD method.

Towards real-time detection of tumor margins using photothermal imaging of immune-targeted gold nanoparticles

PubMed Central

Jakobsohn, Kobi; Motiei, Menachem; Sinvani, Moshe; Popovtzer, Rachela

2012-01-01

Background One of the critical problems in cancer management is local recurrence of disease. Between 20% and 30% of patients who undergo tumor resection surgery require reoperation due to incomplete excision. Currently, there are no validated methods for intraoperative tumor margin detection. In the present work, we demonstrate the potential use of gold nanoparticles (GNPs) as a novel contrast agent for photothermal molecular imaging of cancer. Methods Phantoms containing different concentrations of GNPs were irradiated with continuous-wave laser and measured with a thermal imaging camera which detected the temperature field of the irradiated phantoms. Results The results clearly demonstrate the ability to distinguish between cancerous cells specifically targeted with GNPs and normal cells. This technique, which allows highly sensitive discrimination between adjacent low GNP concentrations, will allow tumor margin detection while the temperature increases by only a few degrees Celsius (for GNPs in relevant biological concentrations). Conclusion We expect this real-time intraoperative imaging technique to assist surgeons in determining clear tumor margins and to maximize the extent of tumor resection while sparing normal background tissue. PMID:22956871

Projected cancer risks potentially related to past, current, and future practices in paediatric CT in the United Kingdom, 1990–2020

PubMed Central

Journy, Neige M Y; Lee, Choonsik; Harbron, Richard W; McHugh, Kieran; Pearce, Mark S; Berrington de González, Amy

2017-01-01

Background: To project risks of developing cancer and the number of cases potentially induced by past, current, and future computed tomography (CT) scans performed in the United Kingdom in individuals aged <20 years. Methods: Organ doses were estimated from surveys of individual scan parameters and CT protocols used in the United Kingdom. Frequencies of scans were estimated from the NHS Diagnostic Imaging Dataset. Excess lifetime risks (ELRs) of radiation-related cancer were calculated as cumulative lifetime risks, accounting for survival probabilities, using the RadRAT risk assessment tool. Results: In 2000–2008, ELRs ranged from 0.3 to 1 per 1000 head scans and 1 to 5 per 1000 non-head scans. ELRs per scan were reduced by 50–70% in 2000–2008 compared with 1990–1995, subsequent to dose reduction over time. The 130 750 scans performed in 2015 in the United Kingdom were projected to induce 64 (90% uncertainty interval (UI): 38–113) future cancers. Current practices would lead to about 300 (90% UI: 230–680) future cancers induced by scans performed in 2016–2020. Conclusions: Absolute excess risks from single exposures would be low compared with background risks, but even small increases in annual CT rates over the next years would substantially increase the number of potential subsequent cancers. PMID:27824812

Reprint of Mechanisms of maintaining high suspended sediment concentration over tide-dominated offshore shoals in the southern Yellow Sea

NASA Astrophysics Data System (ADS)

Xiong, Jilian; Wang, Xiao Hua; Wang, Ya Ping; Chen, Jingdong; Shi, Benwei; Gao, Jianhua; Yang, Yang; Yu, Qian; Li, Mingliang; Yang, Lei; Gong, Xulong

2018-06-01

An understanding of the dynamics and behaviors of suspended sediments is vital in analysis of morphological, environmental, and ecological processes occurring in coastal marine environments. To study the mechanisms of maintaining high suspended sediment concentrations (SSCs) on a tide-dominated offshore shoal, we measured water depths, current velocities, SSCs, wave parameters and bottom sediment compositions in the southern Yellow Sea. These data were then used to calculate bottom shear stresses generated by currents (τc), waves (τw), and wave-current interactions (τcw). SSCs time series exhibited strong quarter-diurnal peaks during spring tides, in contrast to the semidiurnal signal during neap tides. A Fourier analysis showed that suspended sediment variations within tidal cycles was mainly controlled by resuspension in most stations. There existed relatively stable background SSCs (maintaining high SSCs among tidal cycles) values at all four stations during both windy (wind speed > 9.0 m/s) and normal weather conditions (wind speed < 3.0 m/s). The background SSCs had strong relationship with spring/neap-averaged τcw, indicating background SSCs were mainly controlled by mean bottom shear stress, with a minimum value of 0.21 N/m2. On account of the strong tidal currents, background SSCs of spring tides were greater than that of neap tides. In addition, on the base of wavelet, statistics analyses and turbulence dissipation parameter, background SSCs during slack tide in the study area may be maintained by intermittent turbulence events induced by a combined tidal current and wave action.

Mechanisms of maintaining high suspended sediment concentration over tide-dominated offshore shoals in the southern Yellow Sea

NASA Astrophysics Data System (ADS)

Xiong, Jilian; Wang, Xiao Hua; Wang, Ya Ping; Chen, Jingdong; Shi, Benwei; Gao, Jianhua; Yang, Yang; Yu, Qian; Li, Mingliang; Yang, Lei; Gong, Xulong

2017-05-01

An understanding of the dynamics and behaviors of suspended sediments is vital in analysis of morphological, environmental, and ecological processes occurring in coastal marine environments. To study the mechanisms of maintaining high suspended sediment concentrations (SSCs) on a tide-dominated offshore shoal, we measured water depths, current velocities, SSCs, wave parameters and bottom sediment compositions in the southern Yellow Sea. These data were then used to calculate bottom shear stresses generated by currents (τc), waves (τw), and wave-current interactions (τcw). SSCs time series exhibited strong quarter-diurnal peaks during spring tides, in contrast to the semidiurnal signal during neap tides. A Fourier analysis showed that suspended sediment variations within tidal cycles was mainly controlled by resuspension in most stations. There existed relatively stable background SSCs (maintaining high SSCs among tidal cycles) values at all four stations during both windy (wind speed > 9.0 m/s) and normal weather conditions (wind speed < 3.0 m/s). The background SSCs had strong relationship with spring/neap-averaged τcw, indicating background SSCs were mainly controlled by mean bottom shear stress, with a minimum value of 0.21 N/m2. On account of the strong tidal currents, background SSCs of spring tides were greater than that of neap tides. In addition, on the base of wavelet, statistics analyses and turbulence dissipation parameter, background SSCs during slack tide in the study area may be maintained by intermittent turbulence events induced by a combined tidal current and wave action.

Firearm Acquisition Without Background Checks: Results of a National Survey.

PubMed

Miller, Matthew; Hepburn, Lisa; Azrael, Deborah

2017-02-21

In 1994, 40% of U.S. gun owners who had recently acquired a firearm did so without a background check. No contemporary estimates exist. To estimate the proportion of current U.S. gun owners who acquired their most recent firearm without a background check, by time since and manner of acquisition, for the nation as a whole and separately in states with and without legislation regulating private sales. Probability-based online survey. United States, 2015. 1613 adult gun owners. Current gun owners were asked where and when they acquired their last firearm; if they purchased the firearm; and whether, as part of that acquisition, they had a background check (or were asked to show a firearm license or permit). 22% (95% CI, 16% to 27%) of gun owners who reported obtaining their most recent firearm within the previous 2 years reported doing so without a background check. For firearms purchased privately within the previous 2 years (that is, other than from a store or pawnshop, including sales between individuals in person, online, or at gun shows), 50% (CI, 35% to 65%) were obtained without a background check. This percentage was 26% (CI, 5% to 47%) for owners residing in states regulating private firearm sales and 57% (CI, 40% to 75%) for those living in states without regulations on private firearm sales. Potential inaccuracies due to recall and social desirability bias. 22% of current U.S. gun owners who acquired a firearm within the past 2 years did so without a background check. Although this represents a smaller proportion of gun owners obtaining firearms without background checks than in the past, millions of U.S. adults continue to acquire guns without background checks, especially in states that do not regulate private firearm sales. Fund for a Safer Future and the Joyce Foundation.

Enhancing the Detection of Giardia duodenalis Cysts in Foods by Inertial Microfluidic Separation

PubMed Central

Ganz, Kyle R.; Clime, Liviu; Farber, Jeffrey M.; Corneau, Nathalie

2015-01-01

The sensitivity and specificity of current Giardia cyst detection methods for foods are largely determined by the effectiveness of the elution, separation, and concentration methods used. The aim of these methods is to produce a final suspension with an adequate concentration of Giardia cysts for detection and a low concentration of interfering food debris. In the present study, a microfluidic device, which makes use of inertial separation, was designed and fabricated for the separation of Giardia cysts. A cyclical pumping platform and protocol was developed to concentrate 10-ml suspensions down to less than 1 ml. Tests involving Giardia duodenalis cysts and 1.90-μm microbeads in pure suspensions demonstrated the specificity of the microfluidic chip for cysts over smaller nonspecific particles. As the suspension cycled through the chip, a large number of beads were removed (70%) and the majority of the cysts were concentrated (82%). Subsequently, the microfluidic inertial separation chip was integrated into a method for the detection of G. duodenalis cysts from lettuce samples. The method greatly reduced the concentration of background debris in the final suspensions (10-fold reduction) in comparison to that obtained by a conventional method. The method also recovered an average of 68.4% of cysts from 25-g lettuce samples and had a limit of detection (LOD) of 38 cysts. While the recovery of cysts by inertial separation was slightly lower, and the LOD slightly higher, than with the conventional method, the sample analysis time was greatly reduced, as there were far fewer background food particles interfering with the detection of cysts by immunofluorescence microscopy. PMID:25841016

Ion Storage with the High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James; Lewis, Raymond; Chakrabarti, Suman; Pearson, Boise

2002-01-01

The matter antimatter reaction represents the densest form of energy storage/release known to modern physics: as such it offers one of the most compact sources of power for future deep space exploration. To take the first steps along this path, NASA-Marshall Space Flight Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a goal of maintaining 10(exp 12) particles for up to 18 days. Experiments have been performed with this hardware using normal matter (positive hydrogen ions) to assess the device's ability to hold charged particles. These ions are currently created using an electron gun method to ionize background gas; however, this technique is limited by the quantity that can be captured. To circumvent this issue, an ion source is currently being commissioned which will greatly increase the number of ions captured and more closely simulate actual operations expected at an antiproton production facility. Ions have been produced, stored for various time intervals, and then extracted against detectors to measure species, quantity and energy. Radio frequency stabilization has been tested as a method to prolong ion lifetime: results show an increase in the baseline 1/e lifetime of trapped particles from hours to days. Impurities in the residual background gas (typically carbon-containing species CH4, CO, CO2, etc.) present a continuing problem by reducing the trapped hydrogen population through the mechanism of ion charge exchange.

Multiple Frequency Audio Signal Communication as a Mechanism for Neurophysiology and Video Data Synchronization

PubMed Central

Topper, Nicholas C.; Burke, S.N.; Maurer, A.P.

2014-01-01

BACKGROUND Current methods for aligning neurophysiology and video data are either prepackaged, requiring the additional purchase of a software suite, or use a blinking LED with a stationary pulse-width and frequency. These methods lack significant user interface for adaptation, are expensive, or risk a misalignment of the two data streams. NEW METHOD A cost-effective means to obtain high-precision alignment of behavioral and neurophysiological data is obtained by generating an audio-pulse embedded with two domains of information, a low-frequency binary-counting signal and a high, randomly changing frequency. This enabled the derivation of temporal information while maintaining enough entropy in the system for algorithmic alignment. RESULTS The sample to frame index constructed using the audio input correlation method described in this paper enables video and data acquisition to be aligned at a sub-frame level of precision. COMPARISONS WITH EXISTING METHOD Traditionally, a synchrony pulse is recorded on-screen via a flashing diode. The higher sampling rate of the audio input of the camcorder enables the timing of an event to be detected with greater precision. CONCLUSIONS While On-line analysis and synchronization using specialized equipment may be the ideal situation in some cases, the method presented in the current paper presents a viable, low cost alternative, and gives the flexibility to interface with custom off-line analysis tools. Moreover, the ease of constructing and implements this set-up presented in the current paper makes it applicable to a wide variety of applications that require video recording. PMID:25256648

Substance P Depolarizes Lamprey Spinal Cord Neurons by Inhibiting Background Potassium Channels.

PubMed

Thörn Pérez, Carolina; Hill, Russell H; Grillner, Sten

2015-01-01

Substance P is endogenously released in the adult lamprey spinal cord and accelerates the burst frequency of fictive locomotion. This is achieved by multiple effects on interneurons and motoneurons, including an attenuation of calcium currents, potentiation of NMDA currents and reduction of the reciprocal inhibition. While substance P also depolarizes spinal cord neurons, the underlying mechanism has not been resolved. Here we show that effects of substance P on background K+ channels are the main source for this depolarization. Hyperpolarizing steps induced inward currents during whole-cell voltage clamp that were reduced by substance P. These background K+ channels are pH sensitive and are selectively blocked by anandamide and AVE1231. These blockers counteracted the effect of substance P on these channels and the resting membrane potential depolarization in spinal cord neurons. Thus, we have shown now that substance P inhibits background K+ channels that in turn induce depolarization, which is likely to contribute to the frequency increase observed with substance P during fictive locomotion.

Substance P Depolarizes Lamprey Spinal Cord Neurons by Inhibiting Background Potassium Channels

PubMed Central

Thörn Pérez, Carolina; Hill, Russell H.; Grillner, Sten

2015-01-01

Substance P is endogenously released in the adult lamprey spinal cord and accelerates the burst frequency of fictive locomotion. This is achieved by multiple effects on interneurons and motoneurons, including an attenuation of calcium currents, potentiation of NMDA currents and reduction of the reciprocal inhibition. While substance P also depolarizes spinal cord neurons, the underlying mechanism has not been resolved. Here we show that effects of substance P on background K+ channels are the main source for this depolarization. Hyperpolarizing steps induced inward currents during whole-cell voltage clamp that were reduced by substance P. These background K+ channels are pH sensitive and are selectively blocked by anandamide and AVE1231. These blockers counteracted the effect of substance P on these channels and the resting membrane potential depolarization in spinal cord neurons. Thus, we have shown now that substance P inhibits background K+ channels that in turn induce depolarization, which is likely to contribute to the frequency increase observed with substance P during fictive locomotion. PMID:26197458

A Survey of Elementary and Secondary Music Educators' Professional Background, Teaching Responsibilities and Job Satisfaction in the United States

ERIC Educational Resources Information Center

Matthews, Wendy K.; Koner, Karen

2017-01-01

The focus of this exploratory study was to examine the current trends of K-12 music educators in the United States regarding their (a) professional background, (b) classroom teaching responsibilities, and (c) job satisfaction. Participants included seven thousand four hundred and sixty-three (N = 7,463) currently employed music teachers who were…

Current and future risks of asbestos exposure in the Australian community

PubMed Central

2016-01-01

Background Australia mined asbestos for more than 100 years and manufactured and imported asbestos products. There is a legacy of in situ asbestos throughout the built environment. Methods The aim of this study was to identify the possible sources of current and future asbestos exposure from the built environment. Telephone interviews with environmental health officers, asbestos removalists, and asbestos assessors in Australia sought information about common asbestos scenarios encountered. Results There is a considerable amount of asbestos remaining in situ in the Australian built environment. Potential current and future sources of asbestos exposure to the public are from asbestos-containing roofs and fences, unsafe asbestos removal practices, do-it-yourself home renovations and illegal dumping. Conclusion This research has highlighted a need for consistent approaches in the regulation and enforcement of safe practices for the management and removal of asbestos to ensure that in situ asbestos in the built environment is managed appropriately. PMID:27611196

A global time-dependent model of thunderstorm electricity. I - Mathematical properties of the physical and numerical models

NASA Technical Reports Server (NTRS)

Browning, G. L.; Tzur, I.; Roble, R. G.

1987-01-01

A time-dependent model is introduced that can be used to simulate the interaction of a thunderstorm with its global electrical environment. The model solves the continuity equation of the Maxwell current, which is assumed to be composed of the conduction, displacement, and source currents. Boundary conditions which can be used in conjunction with the continuity equation to form a well-posed initial-boundary value problem are determined. Properties of various components of solutions of the initial-boundary value problem are analytically determined. The results indicate that the problem has two time scales, one determined by the background electrical conductivity and the other by the time variation of the source function. A numerical method for obtaining quantitative results is introduced, and its properties are studied. Some simulation results on the evolution of the displacement and conduction currents during the electrification of a storm are presented.

Preliminary scaling laws for plasma current, ion kinetic temperature, and plasma number density in the NASA Lewis Bumpy Torus plasma

NASA Technical Reports Server (NTRS)

Roth, J. R.

1976-01-01

Parametric variation of independent variables which may affect the characteristics of the NASA Lewis Bumpy Torus plasma have identified those which have a significant effect on the plasma current, ion kinetic temperature, and plasma number density, and those which do not. Empirical power-law correlations of the plasma current, and the ion kinetic temperature and number density were obtained as functions of the potential applied to the midplane electrode rings, the background neutral gas pressure, and the magnetic field strength. Additional parameters studied include the type of gas, the polarity of the midplane electrode rings (and hence the direction of the radial electric field), the mode of plasma operation, and the method of measuring the plasma number density. No significant departures from the scaling laws appear to occur at the highest ion kinetic temperatures or number densities obtained to date.

Transcranial Direct Current Stimulation (tDCS): A Promising Treatment for Major Depressive Disorder?

PubMed Central

Bennabi, Djamila; Haffen, Emmanuel

2018-01-01

Background: Transcranial direct current stimulation (tDCS) opens new perspectives in the treatment of major depressive disorder (MDD), because of its ability to modulate cortical excitability and induce long-lasting effects. The aim of this review is to summarize the current status of knowledge regarding tDCS application in MDD. Methods: In this review, we searched for articles published in PubMed/MEDLINE from the earliest available date to February 2018 that explored clinical and cognitive effects of tDCS in MDD. Results: Despite differences in design and stimulation parameters, the examined studies indicated beneficial effects of tDCS for MDD. These preliminary results, the non-invasiveness of tDCS, and its good tolerability support the need for further research on this technique. Conclusions: tDCS constitutes a promising therapeutic alternative for patients with MDD, but its place in the therapeutic armamentarium remains to be determined. PMID:29734768

Feedback control of persistent-current oscillation based on the atomic-clock technique

NASA Astrophysics Data System (ADS)

Yu, Deshui; Dumke, Rainer

2018-05-01

We propose a scheme of stabilizing the persistent-current Rabi oscillation based on the flux qubit-resonator-atom hybrid structure. The low-Q L C resonator weakly interacts with the flux qubit and maps the persistent-current Rabi oscillation of the flux qubit onto the intraresonator electric field. This oscillating electric field is further coupled to a Rydberg-Rydberg transition of the 87Rb atoms. The Rabi-frequency fluctuation of the flux qubit is deduced from measuring the atomic population via the fluorescence detection and stabilized by feedback controlling the external flux bias. Our numerical simulation indicates that the feedback-control method can efficiently suppress the background fluctuations in the flux qubit, especially in the low-frequency limit. This technique may be extensively applicable to different types of superconducting circuits, paving a way to long-term-coherence superconducting quantum information processing.

Current Controversies in Diagnosis and Management of Cleft Palate and Velopharyngeal Insufficiency

PubMed Central

Ysunza, Pablo Antonio; Repetto, Gabriela M.; Pamplona, Maria Carmen; Calderon, Juan F.; Shaheen, Kenneth; Chaiyasate, Konkgrit; Rontal, Matthew

2015-01-01

Background. One of the most controversial topics concerning cleft palate is the diagnosis and treatment of velopharyngeal insufficiency (VPI). Objective. This paper reviews current genetic aspects of cleft palate, imaging diagnosis of VPI, the planning of operations for restoring velopharyngeal function during speech, and strategies for speech pathology treatment of articulation disorders in patients with cleft palate. Materials and Methods. An updated review of the scientific literature concerning genetic aspects of cleft palate was carried out. Current strategies for assessing and treating articulation disorders associated with cleft palate were analyzed. Imaging procedures for assessing velopharyngeal closure during speech were reviewed, including a recent method for performing intraoperative videonasopharyngoscopy. Results. Conclusions from the analysis of genetic aspects of syndromic and nonsyndromic cleft palate and their use in its diagnosis and management are presented. Strategies for classifying and treating articulation disorders in patients with cleft palate are presented. Preliminary results of the use of multiplanar videofluoroscopy as an outpatient procedure and intraoperative endoscopy for the planning of operations which aimed to correct VPI are presented. Conclusion. This paper presents current aspects of the diagnosis and management of patients with cleft palate and VPI including 3 main aspects: genetics and genomics, speech pathology and imaging diagnosis, and surgical management. PMID:26273595

Tools for Implementing Science Practice in a Large Introductory Class

NASA Astrophysics Data System (ADS)

Prothero, W. A.

2008-12-01

Scientists must have in-depth background knowledge of their subject area and know where current knowledge can be advanced. They perform experiments that gather data to test new or existing theories, present their findings at meetings, publish their results, critically review the results of others, and respond to the reviews of their own work. In the context of a course, these activities correspond to learning the background material by listening to lectures or reading a text, formulating a problem, exploring data using student friendly data access and plotting software, giving brief talks to classmates in a small class or lab setting, writing a science paper or lab report, reviewing the writing of their peers, and receiving feedback (and grades) from their instructors and/or peers. These activities can be supported using course management software and online resources. The "LearningWithData" software system allows solid Earth (focused on plate tectonics) data exploration and plotting. Ocean data access, display, and plotting are also supported. Background material is delivered using animations and slide show type displays. Students are accountable for their learning through included homework assignments. Lab and small group activities provide support for data exploration and interpretation. Writing is most efficiently implemented using the "Calibrated Peer Review" method. This methodology is available at http://cpr.molsci.ucla.edu/. These methods have been successfully implemented in a large oceanography class at UCSB.

A Method for Detecting Circulating Tumor Cells Based on the Measurement of Single-Cell Metabolism in Droplet-Based Microfluidics.

PubMed

Del Ben, Fabio; Turetta, Matteo; Celetti, Giorgia; Piruska, Aigars; Bulfoni, Michela; Cesselli, Daniela; Huck, Wilhelm T S; Scoles, Giacinto

2016-07-18

The number of circulating tumor cells (CTCs) in blood is strongly correlated with the progress of metastatic cancer. Current methods to detect CTCs are based on immunostaining or discrimination of physical properties. Herein, a label-free method is presented exploiting the abnormal metabolic behavior of cancer cells. A single-cell analysis technique is used to measure the secretion of acid from individual living tumor cells compartmentalized in microfluidically prepared, monodisperse, picoliter (pL) droplets. As few as 10 tumor cells can be detected in a background of 200 000 white blood cells and proof-of-concept data is shown on the detection of CTCs in the blood of metastatic patients. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Feeding currents of the upside down jellyfish in the presence of background flow.

PubMed

Hamlet, Christina L; Miller, Laura A

2012-11-01

The upside-down jellyfish (Cassiopea spp.) is an ideal organism for examining feeding and exchange currents generated by bell pulsations due to its relatively sessile nature. Previous experiments and numerical simulations have shown that the oral arms play an important role in directing new fluid into the bell from along the substrate. All of this work, however, has considered the jellyfish in the absence of background flow, but the natural environments of Cassiopea and other cnidarians are dynamic. Flow velocities and directions fluctuate on multiple time scales, and mechanisms of particle capture may be fundamentally different in moving fluids. In this paper, the immersed boundary method is used to simulate a simplified jellyfish in flow. The elaborate oral arm structure is modeled as a homogenous porous layer. The results show that the oral arms trap vortices as they form during contraction and expansion of the bell. For constant flow conditions, the vortices are directed gently across the oral arms where particle capture occurs. For variable direction flows, the secondary structures change the overall pattern of the flow around the bell and appear to stabilize regions of mixing around the secondary mouths.

Search for neutrinoless double beta decay with GERDA phase II

NASA Astrophysics Data System (ADS)

Agostini, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Di Marco, N.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knies, J.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Majorovits, B.; Maneschg, W.; Marissens, G.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Ransom, C.; Reissfelder, M.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Seitz, H.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

2017-10-01

The GERmanium Detector Array (gerda) experiment, located at the Gran Sasso underground laboratory in Italy, is one of the leading experiments for the search of 0νββ decay. In Phase II of the experiment 35.6 kg of enriched germanium detectors are operated. The application of active background rejection methods, such as a liquid argon scintillation light read-out and pulse shape discrimination of germanium detector signals, allowed to reduce the background index to the intended level of 10-3 cts/(keV.kg.yr). In the first five month of data taking 10.8 kg yr of exposure were accumulated. No signal has been found and together with data from Phase I a new limit for the neutrinoless double beta decay half-life of 76Ge of 5.3 . 1025 yr at 90% C.L. was established in June 2016. Phase II data taking is ongoing and will allow the exploration of half-lifes in the 1026 yr regime. The current status of data taking and an update on the background index are presented.

Modification of surfaces of silver nanoparticles for controlled deposition of silicon, manganese, and titanium dioxides

NASA Astrophysics Data System (ADS)

Apostolova, Tzveta; Obreshkov, B. D.; Ionin, A. A.; Kudryashov, S. I.; Makarov, S. V.; Mel'nik, N. N.; Rudenko, A. A.

2018-01-01

In this work we show that nanometric-thick layers of SiO2, MnO2, and TiO2 may be effectively deposited on various silver nanoparticles (including cubic Ag nanoparticles) covered by a very thin (below 0.4 nm) layer of silver sulphide. The background in Raman measurements generated by sulphide-protected Ag nanoparticles is significantly smaller than that for analogous Ag nanoparticles protected by a monolayer formed from alkanethiols - depositing alkanethiols on a surface of anisotropic silver nanoparticles is the current standard method used for protecting a surface of Ag nanoparticles before depositing a layer of silica. Because of significantly smaller generated Raman background, Ag@SiO2 nanostructures with an Ag2S linkage layer between the silver core and the silica shell are very promising low-background electromagnetic nanoresonators for carrying out Raman analysis of various surfaces - especially using what is known as shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). Sample SHINERS analyses of various surfaces (including pesticide-contaminated surfaces of tomatoes) using cubic-Ag@SiO2 nanoparticles as electromagnetic nanoresonators are also presented.

Clinical Research with Transcranial Direct Current Stimulation (tDCS): Challenges and Future Directions

PubMed Central

Brunoni, Andre Russowsky; Nitsche, Michael A.; Bolognini, Nadia; Bikson, Marom; Wagner, Tim; Merabet, Lotfi; Edwards, Dylan J.; Valero-Cabre, Antoni; Rotenberg, Alexander; Pascual-Leone, Alvaro; Ferrucci, Roberta; Priori, Alberto; Boggio, Paulo; Fregni, Felipe

2011-01-01

Background Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past ten years, tDCS physiological mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodological, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them. Methods We convened a workgroup of researchers in the field to review, discuss and provide updates and key challenges of neuromodulation use for clinical research. Main Findings/Discussion We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (i) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (ii) methodological aspects related to the clinical research of tDCS as divided according to study phase (i.e., preclinical, phase I, phase II and phase III studies); (iii) ethical and regulatory concerns; (iv) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS. PMID:22037126

Estimating background-subtracted fluorescence transients in calcium imaging experiments: a quantitative approach.

PubMed

Joucla, Sébastien; Franconville, Romain; Pippow, Andreas; Kloppenburg, Peter; Pouzat, Christophe

2013-08-01

Calcium imaging has become a routine technique in neuroscience for subcellular to network level investigations. The fast progresses in the development of new indicators and imaging techniques call for dedicated reliable analysis methods. In particular, efficient and quantitative background fluorescence subtraction routines would be beneficial to most of the calcium imaging research field. A background-subtracted fluorescence transients estimation method that does not require any independent background measurement is therefore developed. This method is based on a fluorescence model fitted to single-trial data using a classical nonlinear regression approach. The model includes an appropriate probabilistic description of the acquisition system's noise leading to accurate confidence intervals on all quantities of interest (background fluorescence, normalized background-subtracted fluorescence time course) when background fluorescence is homogeneous. An automatic procedure detecting background inhomogeneities inside the region of interest is also developed and is shown to be efficient on simulated data. The implementation and performances of the proposed method on experimental recordings from the mouse hypothalamus are presented in details. This method, which applies to both single-cell and bulk-stained tissues recordings, should help improving the statistical comparison of fluorescence calcium signals between experiments and studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Adaptive removal of background and white space from document images using seam categorization

NASA Astrophysics Data System (ADS)

Fillion, Claude; Fan, Zhigang; Monga, Vishal

2011-03-01

Document images are obtained regularly by rasterization of document content and as scans of printed documents. Resizing via background and white space removal is often desired for better consumption of these images, whether on displays or in print. While white space and background are easy to identify in images, existing methods such as naïve removal and content aware resizing (seam carving) each have limitations that can lead to undesirable artifacts, such as uneven spacing between lines of text or poor arrangement of content. An adaptive method based on image content is hence needed. In this paper we propose an adaptive method to intelligently remove white space and background content from document images. Document images are different from pictorial images in structure. They typically contain objects (text letters, pictures and graphics) separated by uniform background, which include both white paper space and other uniform color background. Pixels in uniform background regions are excellent candidates for deletion if resizing is required, as they introduce less change in document content and style, compared with deletion of object pixels. We propose a background deletion method that exploits both local and global context. The method aims to retain the document structural information and image quality.

Characterization of unknown genetic modifications using high throughput sequencing and computational subtraction

PubMed Central

Tengs, Torstein; Zhang, Haibo; Holst-Jensen, Arne; Bohlin, Jon; Butenko, Melinka A; Kristoffersen, Anja Bråthen; Sorteberg, Hilde-Gunn Opsahl; Berdal, Knut G

2009-01-01

Background When generating a genetically modified organism (GMO), the primary goal is to give a target organism one or several novel traits by using biotechnology techniques. A GMO will differ from its parental strain in that its pool of transcripts will be altered. Currently, there are no methods that are reliably able to determine if an organism has been genetically altered if the nature of the modification is unknown. Results We show that the concept of computational subtraction can be used to identify transgenic cDNA sequences from genetically modified plants. Our datasets include 454-type sequences from a transgenic line of Arabidopsis thaliana and published EST datasets from commercially relevant species (rice and papaya). Conclusion We believe that computational subtraction represents a powerful new strategy for determining if an organism has been genetically modified as well as to define the nature of the modification. Fewer assumptions have to be made compared to methods currently in use and this is an advantage particularly when working with unknown GMOs. PMID:19814792

Position and Speed Control of Brushless DC Motors Using Sensorless Techniques and Application Trends

PubMed Central

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks. PMID:22163582

Improvements in Technique of NMR Imaging and NMR Diffusion Measurements in the Presence of Background Gradients.

NASA Astrophysics Data System (ADS)

Lian, Jianyu

In this work, modification of the cosine current distribution rf coil, PCOS, has been introduced and tested. The coil produces a very homogeneous rf magnetic field, and it is inexpensive to build and easy to tune for multiple resonance frequency. The geometrical parameters of the coil are optimized to produce the most homogeneous rf field over a large volume. To avoid rf field distortion when the coil length is comparable to a quarter wavelength, a parallel PCOS coil is proposed and discussed. For testing rf coils and correcting B _1 in NMR experiments, a simple, rugged and accurate NMR rf field mapping technique has been developed. The method has been tested and used in 1D, 2D, 3D and in vivo rf mapping experiments. The method has been proven to be very useful in the design of rf coils. To preserve the linear relation between rf output applied on an rf coil and modulating input for an rf modulating -amplifying system of NMR imaging spectrometer, a quadrature feedback loop is employed in an rf modulator with two orthogonal rf channels to correct the amplitude and phase non-linearities caused by the rf components in the rf system. The modulator is very linear over a large range and it can generate an arbitrary rf shape. A diffusion imaging sequence has been developed for measuring and imaging diffusion in the presence of background gradients. Cross terms between the diffusion sensitizing gradients and background gradients or imaging gradients can complicate diffusion measurement and make the interpretation of NMR diffusion data ambiguous, but these have been eliminated in this method. Further, the background gradients has been measured and imaged. A dipole random distribution model has been established to study background magnetic fields Delta B and background magnetic gradients G_0 produced by small particles in a sample when it is in a B_0 field. From this model, the minimum distance that a spin can approach a particle can be determined by measuring and <{bf G}_sp{0 }{2}>. From this model, the particle concentration in a sample can be determined by measuring the lineshape of a free induction decay (fid).

Observation of increased space-charge limited thermionic electron emission current by neutral gas ionization in a weakly-ionized deuterium plasma

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

Hollmann, E. M.; Yu, J. H.; Doerner, R. P.

2015-09-14

The thermionic electron emission current emitted from a laser-produced hot spot on a tungsten target in weakly-ionized deuterium plasma is measured. It is found to be one to two orders of magnitude larger than expected for bipolar space charge limited thermionic emission current assuming an unperturbed background plasma. This difference is attributed to the plasma being modified by ionization of background neutrals by the emitted electrons. This result indicates that the allowable level of emitted thermionic electron current can be significantly enhanced in weakly-ionized plasmas due to the presence of large neutral densities.

Magnetospheric Reconnection in Modified Current-Sheet Equilibria

NASA Astrophysics Data System (ADS)

Newman, D. L.; Goldman, M. V.; Lapenta, G.; Markidis, S.

2012-10-01

Particle simulations of magnetic reconnection in Earth's magnetosphere are frequently initialized with a current-carrying Harris equilibrium superposed on a current-free uniform background plasma. The Harris equilibrium satisfies local charge neutrality, but requires that the sheet current be dominated by the hotter species -- often the ions in Earth's magnetosphere. This constraint is not necessarily consistent with observations. A modified kinetic equilibrium that relaxes this constraint on the currents was proposed by Yamada et al. [Phys. Plasmas., 7, 1781 (2000)] with no background population. These modified equilibria were characterized by an asymptotic converging or diverging electrostatic field normal to the current sheet. By reintroducing the background plasma, we have developed new families of equilibria where the asymptotic fields are suppressed by Debye shielding. Because the electrostatic potential profiles of these new equilibria contain wells and/or barriers capable of spatially isolating different populations of electrons and/or ions, these solutions can be further generalized to include classes of asymmetric kinetic equilibria. Examples of both symmetric and asymmetric equilibria will be presented. The dynamical evolution of these equilibria, when perturbed, will be further explored by means of implicit 2D PIC reconnection simulations, including comparisons with simulations employing standard Harris-equilibrium initializations.

Who uses firearms as a means of suicide? A population study exploring firearm accessibility and method choice

PubMed Central

Klieve, Helen; Sveticic, Jerneja; De Leo, Diego

2009-01-01

Background The 1996 Australian National Firearms Agreement introduced strict access limitations. However, reports on the effectiveness of the new legislation are conflicting. This study, accessing all cases of suicide 1997-2004, explores factors which may impact on the choice of firearms as a suicide method, including current licence possession and previous history of legal access. Methods Detailed information on all Queensland suicides (1997-2004) was obtained from the Queensland Suicide Register, with additional details of firearm licence history accessed from the Firearm Registry (Queensland Police Service). Cases were compared against licence history and method choice (firearms or other method). Odds ratios (OR) assessed the risk of firearms suicide and suicide by any method against licence history. A logistic regression was undertaken identifying factors significant in those most likely to use firearms in suicide. Results The rate of suicide using firearms in those with a current license (10.92 per 100,000) far exceeded the rate in those with no license history (1.03 per 100,000). Those with a license history had a far higher rate of suicide (30.41 per 100,000) compared to that of all suicides (15.39 per 100,000). Additionally, a history of firearms licence (current or present) was found to more than double the risk of suicide by any means (OR = 2.09, P < 0.001). The group with the highest risk of selecting firearms to suicide were older males from rural locations. Conclusion Accessibility and familiarity with firearms represent critical elements in determining the choice of method. Further licensing restrictions and the implementation of more stringent secure storage requirements are likely to reduce the overall familiarity with firearms in the community and contribute to reductions in rates of suicide. PMID:19778414

Federal Child Care Policy. Current and Proposed. Family Impact Seminar (Washington, D.C., April 28, 1989). Meeting Highlights and Background Briefing Report.

ERIC Educational Resources Information Center

Ooms, Theodora; Herendeen, Lisa

The purpose of this policy seminar, one of a series of family impact seminars, was to consider current and proposed policies of the federal government that concern child care. This document provides highlights of presentations by the seminar panelists and a background briefing report prepared before the meeting. The highlights section summarizes:…

Fair Share or Freeride: Burden Sharing in Post-Cold War NATO

DTIC Science & Technology

2015-05-23

military facilities in Europe. 56 Carl Elk, NATO Common Funds Burdensharing: Background and Current Issues (Washington DC: Congressional Research...Defense Minister Franz Joseph Jung replied, “our contribution is excellent.”114 Germany was clearly proud of its contribution to NATO operations, but...Monsanto, Portugal: NATO Joint Analysis Lessons Learned Centre (JALLC), 2011. Elk, Carl . NATO Common Funds Burdensharing: Background and Current

Background estimation and player detection in badminton video clips using histogram of pixel values along temporal dimension

NASA Astrophysics Data System (ADS)

Peng, Yahui; Ma, Xiao; Gao, Xinyu; Zhou, Fangxu

2015-12-01

Computer vision is an important tool for sports video processing. However, its application in badminton match analysis is very limited. In this study, we proposed a straightforward but robust histogram-based background estimation and player detection methods for badminton video clips, and compared the results with the naive averaging method and the mixture of Gaussians methods, respectively. The proposed method yielded better background estimation results than the naive averaging method and more accurate player detection results than the mixture of Gaussians player detection method. The preliminary results indicated that the proposed histogram-based method could estimate the background and extract the players accurately. We conclude that the proposed method can be used for badminton player tracking and further studies are warranted for automated match analysis.

Image segregation in strabismic amblyopia.

PubMed

Levi, Dennis M

2007-06-01

Humans with naturally occurring amblyopia show deficits thought to involve mechanisms downstream of V1. These include excessive crowding, abnormal global image processing, spatial sampling and symmetry detection and undercounting. Several recent studies suggest that humans with naturally occurring amblyopia show deficits in global image segregation. The current experiments were designed to study figure-ground segregation in amblyopic observers with documented deficits in crowding, symmetry detection, spatial sampling and counting, using similar stimuli. Observers had to discriminate the orientation of a figure (an "E"-like pattern made up of 17 horizontal Gabor patches), embedded in a 7x7 array of Gabor patches. When the 32 "background" patches are vertical, the "E" pops-out, due to segregation by orientation and performance is perfect; however, if the background patches are all, or mostly horizontal, the "E" is camouflaged, and performance is random. Using a method of constant stimuli, we varied the number of "background" patches that were vertical and measured the probability of correct discrimination of the global orientation of the E (up/down/left/right). Surprisingly, amblyopes who showed strong crowding and deficits in symmetry detection and counting, perform normally or very nearly so in this segregation task. I therefore conclude that these deficits are not a consequence of abnormal segregation of figure from background.

Changes to Articulatory Kinematics in Response to Loudness Cues in Individuals with Parkinson’s Disease

PubMed Central

Darling, Meghan; Huber, Jessica E.

2012-01-01

Purpose Individuals with Parkinson’s disease (PD) exhibit differences in displacement and velocity of the articulators as compared to older adults. The purpose of the current study was to examine effects of three loudness cues on articulatory movement patterns in individuals with PD. Methods Nine individuals diagnosed with idiopathic PD and 9 age- and sex- matched healthy controls produced sentences in four conditions: 1) comfortable loudness, 2) targeting 10dB above comfortable, 3) twice as loud as comfortable, and 4) in background noise. Lip and jaw kinematics and acoustic measurements were obtained. Results Both groups significantly increased sound pressure level (SPL) in the loud conditions as compared to comfortable. For the loud conditions, both groups had the highest SPL in background noise and 10dB and the lowest in twice as loud. Control participants produced the largest opening displacement in background noise and the smallest in twice as loud. Conversely, individuals with PD produced the largest opening displacement in twice as loud and the smallest in background noise. Conclusions Control participants and individuals with PD responded to cues to increase loudness in different ways. Changes in SPL may explain differences in kinematics for the control participants, but do not for individuals with PD. PMID:21386044

Film Vetoes for Alpha Background Rejection in Bolometer Detectors

NASA Astrophysics Data System (ADS)

Deporzio, Nicholas; Bucci, Carlo; Canonica, Lucia; Divacri, Marialaura; Cuore Collaboration; Absurd Team

2015-04-01

This study characterizes the effectiveness of encasing bolometer detectors in scintillator, metal ionization, and more exotic films to veto alpha radiation background. Bolometers are highly susceptible to alpha background and a successful veto should boost the statistical strength, speed, and signal-background ratio of bolometer particle searches. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4 MeV to 6.0 MeV alpha particles representative of detector conditions. Photomultipliers detect the keV range scintillation light and produce a veto signal. Also, layered films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased with 0.1V to 100V to produce a current signal when incident 1.4 MeV to 6.0 MeV alpha particles ionize conduction paths through the film. Veto signals are characterized by their affect on bolometer detection of 865 keV target signals. Similar methods are applied to more exotic films. Early results show scintillator films raise target signal count rate and suppress counts above target energy by at least a factor of 10. This indicates scintillation vetoes are effective and that metal ionization and other films under study will also be effective.

A new background subtraction method for energy dispersive X-ray fluorescence spectra using a cubic spline interpolation

NASA Astrophysics Data System (ADS)

Yi, Longtao; Liu, Zhiguo; Wang, Kai; Chen, Man; Peng, Shiqi; Zhao, Weigang; He, Jialin; Zhao, Guangcui

2015-03-01

A new method is presented to subtract the background from the energy dispersive X-ray fluorescence (EDXRF) spectrum using a cubic spline interpolation. To accurately obtain interpolation nodes, a smooth fitting and a set of discriminant formulations were adopted. From these interpolation nodes, the background is estimated by a calculated cubic spline function. The method has been tested on spectra measured from a coin and an oil painting using a confocal MXRF setup. In addition, the method has been tested on an existing sample spectrum. The result confirms that the method can properly subtract the background.

Image characterization metrics for muon tomography

NASA Astrophysics Data System (ADS)

Luo, Weidong; Lehovich, Andre; Anashkin, Edward; Bai, Chuanyong; Kindem, Joel; Sossong, Michael; Steiger, Matt

2014-05-01

Muon tomography uses naturally occurring cosmic rays to detect nuclear threats in containers. Currently there are no systematic image characterization metrics for muon tomography. We propose a set of image characterization methods to quantify the imaging performance of muon tomography. These methods include tests of spatial resolution, uniformity, contrast, signal to noise ratio (SNR) and vertical smearing. Simulated phantom data and analysis methods were developed to evaluate metric applicability. Spatial resolution was determined as the FWHM of the point spread functions in X, Y and Z axis for 2.5cm tungsten cubes. Uniformity was measured by drawing a volume of interest (VOI) within a large water phantom and defined as the standard deviation of voxel values divided by the mean voxel value. Contrast was defined as the peak signals of a set of tungsten cubes divided by the mean voxel value of the water background. SNR was defined as the peak signals of cubes divided by the standard deviation (noise) of the water background. Vertical smearing, i.e. vertical thickness blurring along the zenith axis for a set of 2 cm thick tungsten plates, was defined as the FWHM of vertical spread function for the plate. These image metrics provided a useful tool to quantify the basic imaging properties for muon tomography.

A Study of the Air Force’s Current Method of Training Individuals to Use Contractor Developed Software in Information Management and the Perceived Effectiveness of Training

DTIC Science & Technology

1990-12-01

and only one Navy study was located. Lt. Cynthia S. Lassnoff (USN) conducted a case analysis of the training requirements of Navy microcomputer users...effectiveness of the training. The study found that greater emphasis must be placed on developing and supporting the use of a standardized training...recommends areas of further research based on the findings of this research. 1-8 II. Background No previous studies were located that evaluated how the Air

Traffic pollution and countermeasures of urban traffic environment

NASA Astrophysics Data System (ADS)

He, Yuhong; Zheng, Chaocheng

2018-01-01

Background: Traffic environment has become a serious social problem in China currently, therefore, urban traffic environment governance is the requirement to solve this issue because as an important place in people's social life, urban traffic environment shows a strong city's energy. Objective: Based on analysis on social function of city traffic environment and its influence of traffic on urban environment in this paper, the goal to establish a healthy urban traffic environment must be included under the aim of sustainable development eternally and feasible measures were put forward afterwards. Method, result, conclusion and possible applications.

Supernovae at the cosmic dawn

NASA Astrophysics Data System (ADS)

Chen, Ke-Jung

2014-03-01

Modern cosmological simulations predict that the first generation of stars formed with a mass scale around 100 M⊙ about 300-400 million years after the Big Bang. When the first stars reached the end of their lives, many of them might have died as energetic supernovae (SNe) that could have significantly affected the early Universe via injecting large amounts of energy and metals into the primordial intergalactic medium. In this paper, we review the current models of the first SNe by discussing on the relevant background physics, computational methods and the latest results.

iPhone and iPad Use in Orthopedic Surgery

PubMed Central

Duncan, Scott F. M.; Hendawi, Tariq K.; Sperling, John; Kakinoki, Ryosuke; Hartsock, Landon

2015-01-01

Background Thousands of healthcare mobile applications (apps) are available, and physicians are increasingly recognizing that mobile technology can improve their workflow and allow them to practice medicine in a better and/or more efficient manner. Methods This article highlights apps compatible with the iPhone and iPad and their utility to the busy orthopedic surgeon. Results Currently available apps address every aspect of healthcare: patient management, reference, education, and research. Conclusion Key aspects of helpful apps include low cost (preferably free), a user-friendly interface, and simplicity. PMID:25829881

Current Status of the Polyamine Research Field

PubMed Central

Pegg, Anthony E.; Casero, Robert A.

2013-01-01

This chapter provides an overview of the polyamine field and introduces the 32 other chapters that make up this volume. These chapters provide a wide range of methods, advice, and background relevant to studies of the function of polyamines, the regulation of their content, their role in disease, and the therapeutic potential of drugs targeting polyamine content and function. The methodology provided in this new volume will enable laboratories already working in this area to expand their experimental techniques and facilitate the entry of additional workers into this rapidly expanding field. PMID:21318864

An operational amplifier B1404UD1A-1 in the patch-clamp current-to-voltage converter.

PubMed

Korzun, A M; Rozinov, S V; Abashin, G I

1997-01-01

The applicability of the home-made operational amplifier B1404UD1A-1 in a patch-clamp current-to-voltage converter was analyzed. Its parameters (background noise, input bias current, and gain-bandwidth product) were estimated. Schematic solutions and practical recommendations for the use of this amplifier in a current-to-voltage converter were given. Based on the background noise and frequency parameters of the converter, we found that this device can be used for measuring ion channel currents with a high sensitivity and within a broad frequency range (0.055 pA, to 1 kHz; 0.4 pA, to 10 kHz). An example of the converter application in experiments is given.

General Aviation in Nebraska: Nebraska SATS Project Background Paper No. 1

NASA Technical Reports Server (NTRS)

Smith, Russell; Wachal, Jocelyn

2000-01-01

The Nebraska SATS project is a state-level component of NASA's Small Aircraft Transportation System (SATS). During the next several years the project will examine several different factors affecting SATS implementation in Nebraska. These include economic and taxation issues, public policy issues, airport planning processes, information dissemination strategies, and systemic change factors. This background paper profiles the general aviation system in Nebraska. It is written to provide information about the "context" within which SATS will be pursued. The primary focus is thus on describing and providing background information about the current situation. A secondary focus is on drawing general conclusions about the ability of the current system to incorporate the types of changes implied by SATS. First, some brief information on the U.S. aviation system is provided. The next two sections profile the current general aviation aircraft and pilot base. Nebraska's system of general aviation airports is then described. Within this section of the paper, information is provided on the different types of general aviation airports in Nebraska, airport activity levels and current infrastructure. The fourth major section of the background paper looks at Nebraska's local airport authorities. These special purpose local governments oversee the majority of the general aviation airports in the state. Among the items examined are total expenditures, capital expenditures and planning activities. Next, the paper provides background information on the Nebraska Department of Aeronautics (NDA) and recent Federal funding for general aviation in Nebraska. The final section presents summary conclusions.

Cloud masking and removal in remote sensing image time series

NASA Astrophysics Data System (ADS)

Gómez-Chova, Luis; Amorós-López, Julia; Mateo-García, Gonzalo; Muñoz-Marí, Jordi; Camps-Valls, Gustau

2017-01-01

Automatic cloud masking of Earth observation images is one of the first required steps in optical remote sensing data processing since the operational use and product generation from satellite image time series might be hampered by undetected clouds. The high temporal revisit of current and forthcoming missions and the scarcity of labeled data force us to cast cloud screening as an unsupervised change detection problem in the temporal domain. We introduce a cloud screening method based on detecting abrupt changes along the time dimension. The main assumption is that image time series follow smooth variations over land (background) and abrupt changes will be mainly due to the presence of clouds. The method estimates the background surface changes using the information in the time series. In particular, we propose linear and nonlinear least squares regression algorithms that minimize both the prediction and the estimation error simultaneously. Then, significant differences in the image of interest with respect to the estimated background are identified as clouds. The use of kernel methods allows the generalization of the algorithm to account for higher-order (nonlinear) feature relations. After the proposed cloud masking and cloud removal, cloud-free time series at high spatial resolution can be used to obtain a better monitoring of land cover dynamics and to generate more elaborated products. The method is tested in a dataset with 5-day revisit time series from SPOT-4 at high resolution and with Landsat-8 time series. Experimental results show that the proposed method yields more accurate cloud masks when confronted with state-of-the-art approaches typically used in operational settings. In addition, the algorithm has been implemented in the Google Earth Engine platform, which allows us to access the full Landsat-8 catalog and work in a parallel distributed platform to extend its applicability to a global planetary scale.

Comparison of presbyopic additions determined by the fused cross-cylinder method using alternative target background colours.

PubMed

Wee, Sung-Hyun; Yu, Dong-Sik; Moon, Byeong-Yeon; Cho, Hyun Gug

2010-11-01

To compare and contrast standard and alternative versions of refractor head (phoropter)-based charts used to determine reading addition. Forty one presbyopic subjects aged between 42 and 60 years were tested. Tentative additions were determined using a red-green background letter chart, and 4 cross-grid charts (with white, red, green, or red-green backgrounds) which were used with the fused cross cylinder (FCC) method. The final addition for a 40 cm working distance was determined for each subject by subjectively adjusting the tentative additions. There were significant differences in the tentative additions obtained using the 5 methods (repeated measures ANOVA, p < 0.001). The mean differences between the tentative and final additions were <0.10 D and were not clinically meaningful, with the exception of the red-green letter test, and the red background in the FCC method. There were no significant differences between the tentative and final additions for the green background in the FCC method (p > 0.05). The intervals of the 95% limits of agreement were under ±0.50 D, and the narrowest interval (±0.26 D) was for the red-green background. The 3 FCC methods with a white, green, or red-green background provided a tentative addition close to the final addition. Compared with the other methods, the FCC method with the red-green background had a narrow range of error. Further, since this method combines the functions of both the fused cross-cylinder test and the duochrome test, it can be a useful technique for determining presbyopic additions. © 2010 The Authors. Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

Data Analysis and Data Mining: Current Issues in Biomedical Informatics

PubMed Central

Bellazzi, Riccardo; Diomidous, Marianna; Sarkar, Indra Neil; Takabayashi, Katsuhiko; Ziegler, Andreas; McCray, Alexa T.

2011-01-01

Summary Background Medicine and biomedical sciences have become data-intensive fields, which, at the same time, enable the application of data-driven approaches and require sophisticated data analysis and data mining methods. Biomedical informatics provides a proper interdisciplinary context to integrate data and knowledge when processing available information, with the aim of giving effective decision-making support in clinics and translational research. Objectives To reflect on different perspectives related to the role of data analysis and data mining in biomedical informatics. Methods On the occasion of the 50th year of Methods of Information in Medicine a symposium was organized, that reflected on opportunities, challenges and priorities of organizing, representing and analysing data, information and knowledge in biomedicine and health care. The contributions of experts with a variety of backgrounds in the area of biomedical data analysis have been collected as one outcome of this symposium, in order to provide a broad, though coherent, overview of some of the most interesting aspects of the field. Results The paper presents sections on data accumulation and data-driven approaches in medical informatics, data and knowledge integration, statistical issues for the evaluation of data mining models, translational bioinformatics and bioinformatics aspects of genetic epidemiology. Conclusions Biomedical informatics represents a natural framework to properly and effectively apply data analysis and data mining methods in a decision-making context. In the future, it will be necessary to preserve the inclusive nature of the field and to foster an increasing sharing of data and methods between researchers. PMID:22146916

Method of Breast Reconstruction Determines Venous Thromboembolism Risk Better Than Current Prediction Models

PubMed Central

Patel, Niyant V.; Wagner, Douglas S.

2015-01-01

Background: Venous thromboembolism (VTE) risk models including the Davison risk score and the 2005 Caprini risk assessment model have been validated in plastic surgery patients. However, their utility and predictive value in breast reconstruction has not been well described. We sought to determine the utility of current VTE risk models in this population and the VTE rate observed in various methods of breast reconstruction. Methods: A retrospective review of breast reconstructions by a single surgeon was performed. One hundred consecutive transverse rectus abdominis myocutaneous (TRAM) patients, 100 consecutive implant patients, and 100 consecutive latissimus dorsi patients were identified over a 10-year period. Patient demographics and presence of symptomatic VTE were collected. 2005 Caprini risk scores and Davison risk scores were calculated for each patient. Results: The TRAM reconstruction group was found to have a higher VTE rate (6%) than the implant (0%) and latissimus (0%) reconstruction groups (P < 0.01). Mean Davison risk scores and 2005 Caprini scores were similar across all reconstruction groups (P > 0.1). The vast majority of patients were stratified as high risk (87.3%) by the VTE risk models. However, only TRAM reconstruction patients demonstrated significant VTE risk. Conclusions: TRAM reconstruction appears to have a significantly higher risk of VTE than both implant and latissimus reconstruction. Current risk models do not effectively stratify breast reconstruction patients at risk for VTE. The method of breast reconstruction appears to have a significant role in patients’ VTE risk. PMID:26090287

Estimation of channel parameters and background irradiance for free-space optical link.

PubMed

Khatoon, Afsana; Cowley, William G; Letzepis, Nick; Giggenbach, Dirk

2013-05-10

Free-space optical communication can experience severe fading due to optical scintillation in long-range links. Channel estimation is also corrupted by background and electrical noise. Accurate estimation of channel parameters and scintillation index (SI) depends on perfect removal of background irradiance. In this paper, we propose three different methods, the minimum-value (MV), mean-power (MP), and maximum-likelihood (ML) based methods, to remove the background irradiance from channel samples. The MV and MP methods do not require knowledge of the scintillation distribution. While the ML-based method assumes gamma-gamma scintillation, it can be easily modified to accommodate other distributions. Each estimator's performance is compared using simulation data as well as experimental measurements. The estimators' performance are evaluated from low- to high-SI areas using simulation data as well as experimental trials. The MV and MP methods have much lower complexity than the ML-based method. However, the ML-based method shows better SI and background-irradiance estimation performance.

The MAJORANA DEMONSTRATOR for 0νββ: Current Status and Future Plans

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

Green, M. P.; Abgrall, N.; Aguayo, Estanislao

2015-03-24

The Majorana Demonstrator will search for neutrinoless-double-beta decay in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based neutrinoless-double-beta decay experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the neutrinoless-double-beta decay region of interest (ROI) ofmore » no more than 3cnts/(ROI-t-y). The current status of the Demonstrator is discussed, as are plans for its completion.« less

Improving Factor Score Estimation Through the Use of Observed Background Characteristics

PubMed Central

Curran, Patrick J.; Cole, Veronica; Bauer, Daniel J.; Hussong, Andrea M.; Gottfredson, Nisha

2016-01-01

A challenge facing nearly all studies in the psychological sciences is how to best combine multiple items into a valid and reliable score to be used in subsequent modelling. The most ubiquitous method is to compute a mean of items, but more contemporary approaches use various forms of latent score estimation. Regardless of approach, outside of large-scale testing applications, scoring models rarely include background characteristics to improve score quality. The current paper used a Monte Carlo simulation design to study score quality for different psychometric models that did and did not include covariates across levels of sample size, number of items, and degree of measurement invariance. The inclusion of covariates improved score quality for nearly all design factors, and in no case did the covariates degrade score quality relative to not considering the influences at all. Results suggest that the inclusion of observed covariates can improve factor score estimation. PMID:28757790

Image retrieval by information fusion based on scalable vocabulary tree and robust Hausdorff distance

NASA Astrophysics Data System (ADS)

Che, Chang; Yu, Xiaoyang; Sun, Xiaoming; Yu, Boyang

2017-12-01

In recent years, Scalable Vocabulary Tree (SVT) has been shown to be effective in image retrieval. However, for general images where the foreground is the object to be recognized while the background is cluttered, the performance of the current SVT framework is restricted. In this paper, a new image retrieval framework that incorporates a robust distance metric and information fusion is proposed, which improves the retrieval performance relative to the baseline SVT approach. First, the visual words that represent the background are diminished by using a robust Hausdorff distance between different images. Second, image matching results based on three image signature representations are fused, which enhances the retrieval precision. We conducted intensive experiments on small-scale to large-scale image datasets: Corel-9, Corel-48, and PKU-198, where the proposed Hausdorff metric and information fusion outperforms the state-of-the-art methods by about 13, 15, and 15%, respectively.

Visual interface for space and terrestrial analysis

NASA Technical Reports Server (NTRS)

Dombrowski, Edmund G.; Williams, Jason R.; George, Arthur A.; Heckathorn, Harry M.; Snyder, William A.

1995-01-01

The management of large geophysical and celestial data bases is now, more than ever, the most critical path to timely data analysis. With today's large volume data sets from multiple satellite missions, analysts face the task of defining useful data bases from which data and metadata (information about data) can be extracted readily in a meaningful way. Visualization, following an object-oriented design, is a fundamental method of organizing and handling data. Humans, by nature, easily accept pictorial representations of data. Therefore graphically oriented user interfaces are appealing, as long as they remain simple to produce and use. The Visual Interface for Space and Terrestrial Analysis (VISTA) system, currently under development at the Naval Research Laboratory's Backgrounds Data Center (BDC), has been designed with these goals in mind. Its graphical user interface (GUI) allows the user to perform queries, visualization, and analysis of atmospheric and celestial backgrounds data.

Assessment of background particulate matter concentrations in small cities and rural locations--Prince George, Canada.

PubMed

Veira, Andreas; Jackson, Peter L; Ainslie, Bruce; Fudge, Dennis

2013-07-01

This study investigates the development and application of a simple method to calculate annual and seasonal PM2.5 and PM10 background concentrations in small cities and rural areas. The Low Pollution Sectors and Conditions (LPSC) method is based on existing measured long-term data sets and is designed for locations where particulate matter (PM) monitors are only influenced by local anthropogenic emission sources from particular wind sectors. The LPSC method combines the analysis of measured hourly meteorological data, PM concentrations, and geographical emission source distributions. PM background levels emerge from measured data for specific wind conditions, where air parcel trajectories measured at a monitoring station are assumed to have passed over geographic sectors with negligible local emissions. Seasonal and annual background levels were estimated for two monitoring stations in Prince George, Canada, and the method was also applied to four other small cities (Burns Lake, Houston, Quesnel, Smithers) in northern British Columbia. The analysis showed reasonable background concentrations for both monitoring stations in Prince George, whereas annual PM10 background concentrations at two of the other locations and PM2.5 background concentrations at one other location were implausibly high. For those locations where the LPSC method was successful, annual background levels ranged between 1.8 +/- 0.1 microg/m3 and 2.5 +/- 0.1 microg/m3 for PM2.5 and between 6.3 +/- 0.3 microg/m3 and 8.5 +/- 0.3 microg/m3 for PM10. Precipitation effects and patterns of seasonal variability in the estimated background concentrations were detectable for all locations where the method was successful. Overall the method was dependent on the configuration of local geography and sources with respect to the monitoring location, and may fail at some locations and under some conditions. Where applicable, the LPSC method can provide a fast and cost-efficient way to estimate background PM concentrations for small cities in sparsely populated regions like northern British Columbia. In rural areas like northern British Columbia, particulate matter (PM) monitoring stations are usually located close to emission sources and residential areas in order to assess the PM impact on human health. Thus there is a lack of accurate PM background concentration data that represent PM ambient concentrations in the absence of local emissions. The background calculation method developed in this study uses observed meteorological data as well as local source emission locations and provides annual, seasonal and precipitation-related PM background concentrations that are comparable to literature values for four out of six monitoring stations.

The Relative Influence of Childhood Sexual Abuse and Other Family Background Risk Factors on Adult Adversities in Female Outpatients Treated for Anxiety Disorders and Depression

ERIC Educational Resources Information Center

Peleikis, Dawn E.; Mykletun, Arnstein; Dahl, Alv A.

2004-01-01

Objective: This study from Norway examines the relative influence of child sexual abuse (CSA) and family background risk factors (FBRF) on the risk for current mental disorders and the quality of current intimate relationships in women with CSA treated for anxiety disorders and/or depression. Women with these disorders frequently seek treatment,…

Anti-Oxidative and Anti-Inflammatory Effects of Ginger in Health and Physical Activity: Review of Current Evidence

PubMed Central

Mashhadi, Nafiseh Shokri; Ghiasvand, Reza; Askari, Gholamreza; Hariri, Mitra; Darvishi, Leila; Mofid, Mohammad Reza

2013-01-01

Background: Ginger (Zingiber officinale Rosc.) belongs to the family Zingiberaceae. The health-promoting perspective of ginger is attributed to its rich phytochemistry. This study aimed to review the current evidence on ginger effects as an anti-inflammatory and anti-oxidative. Methods: We searched MEDLINE for related publications using “ginger” and “anti-oxidative” and “ginger” and “anti-inflammatory” as keywords. This search had considered Papers that had been published between 2000 and 2010 without any filter. Conclusions: The anticancer potential of ginger is well documented and its functional ingredients like gingerols, shogaol, and paradols are the valuable ingredients which can prevent various cancers. This review concludes to favor ginger but some ambiguities necessitate further research before claiming its efficacy. PMID:23717767

Gravitational-wave stochastic background from cosmic strings.

PubMed

Siemens, Xavier; Mandic, Vuk; Creighton, Jolien

2007-03-16

We consider the stochastic background of gravitational waves produced by a network of cosmic strings and assess their accessibility to current and planned gravitational wave detectors, as well as to big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and pulsar timing constraints. We find that current data from interferometric gravitational wave detectors, such as Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds. Future more sensitive LIGO runs and interferometers such as Advanced LIGO and Laser Interferometer Space Antenna (LISA) will be able to explore substantial parts of the parameter space.

Current status of contraceptive use among rural married women in Anhui Province of China.

PubMed

Zhang, X-J; Wang, G-Y; Shen, Q; Yu, Y-L; Sun, Y-H; Yu, G-B; Zhao, D; Ye, D-Q

2009-11-01

This study aims to explore the current status of married women in regard of their use of contraceptive methods (permanent methods versus non-permanent methods) and to find out factors that affect the use of contraceptive methods in rural areas of Anhui Province of China. Survey. Anhui, China. A total of 53,652 married women aged 18-49 years. A multistage probability sampling method was used to identify a representative sample of 53,652 married women aged 18-49 years. All women were asked to provide detailed information by completing detailed questionnaires. Contraceptive prevalence and influence factors. The total birth control rate of the sample was 95.2%. Samples choosing the permanent and nonpermanent contraceptive methods have taken up 46.7 and 48.5% respectively. Female sterilisation was the first choice with a usage rate of 43.6%, followed by intrauterine device (IUD), which was used by 41.1% of samples. Single-variable analysis showed that the choice of contraceptive methods was associated with age, education level, parity, frequency of sex intercourses in a month, contraceptive knowledge, RTI symptom and the gender of the last child of rural married women. A significant increase in contraceptive use of rural married women in Anhui Province of China. Female sterilisation and IUD still play the dominant role. Effective family planning methods should be advocated through adequate counselling on the correct use and proper management, with consideration of the background of custom and belief.

Exploring tool innovation: a comparison of Western and Bushman children.

PubMed

Nielsen, Mark; Tomaselli, Keyan; Mushin, Ilana; Whiten, Andrew

2014-10-01

A capacity for constructing new tools, or using old tools in new ways, to solve novel problems is a core feature of what it means to be human. Yet current evidence suggests that young children are surprisingly poor at innovating tools. However, all studies of tool innovation to date have been conducted with children from comparatively privileged Western backgrounds. This raises questions as to whether or not previously documented tool innovation failure is culturally and economically specific. In the current study, thus, we explored the innovation capacities of children from Westernized urban backgrounds and from remote communities of South African Bushmen. Consistent with past research, we found tool innovation to occur at extremely low rates and that cultural background had no bearing on this. The current study is the first to empirically test tool innovation in children from non-Western backgrounds, with our data being consistent with the view that despite its key role in human evolution, a capacity for innovation in tool making remains remarkably undeveloped during early childhood. Copyright © 2014 Elsevier Inc. All rights reserved.

The use and interpretation of in vitro data in regulatory toxicology: cosmetics, toiletries and household products.

PubMed

Indans, Ian

2002-02-28

There is currently a drive to eliminate animal testing for cosmetics, toiletries and household products; indeed, the European Union Cosmetics Directive aims to prohibit the use of experimental animals for the testing of finished cosmetic products after 2002. At present, national prohibitions are in place in the UK, Germany, Austria and the Netherlands, for the testing of finished cosmetic products and cosmetic ingredients. In the USA animal testing for certain types of finished products is mandatory. Against this background, the currently available regulatory in vitro tests comprise methods for eye irritation, skin corrosivity, genotoxicity, dermal penetration and photoirritation. The draft updates to the Organisation for Economic Co-operation and Development guidelines for eye and skin irritation advocate the use of in vitro or ex vivo methods prior to the commencement of animal studies. At present, testing for these endpoints cannot be completed in vitro, but potentially corrosive substances and products can be classified without the need for animal studies. Regulatory genotoxicity testing can be completed using only in vitro methods, provided that a clear negative outcome is obtained for each test. Data from dermal penetration studies may be used to refine risk assessments. Current developments in areas such as skin sensitisation and skin irritation promise that in the reasonably near future such information may be generated without the use of animals.

A State-of-the-Art Review: Personalization of Tinnitus Sound Therapy

PubMed Central

Searchfield, Grant D.; Durai, Mithila; Linford, Tania

2017-01-01

Background: There are several established, and an increasing number of putative, therapies using sound to treat tinnitus. There appear to be few guidelines for sound therapy selection and application. Aim: To review current approaches to personalizing sound therapy for tinnitus. Methods: A “state-of-the-art” review (Grant and Booth, 2009) was undertaken to answer the question: how do current sound-based therapies for tinnitus adjust for tinnitus heterogeneity? Scopus, Google Scholar, Embase and PubMed were searched for the 10-year period 2006–2016. The search strategy used the following key words: “tinnitus” AND “sound” AND “therapy” AND “guidelines” OR “personalized” OR “customized” OR “individual” OR “questionnaire” OR “selection.” The results of the review were cataloged and organized into themes. Results: In total 165 articles were reviewed in full, 83 contained sufficient details to contribute to answering the study question. The key themes identified were hearing compensation, pitched-match therapy, maskability, reaction to sound and psychosocial factors. Although many therapies mentioned customization, few could be classified as being personalized. Several psychoacoustic and questionnaire-based methods for assisting treatment selection were identified. Conclusions: Assessment methods are available to assist clinicians to personalize sound-therapy and empower patients to be active in therapy decision-making. Most current therapies are modified using only one characteristic of the individual and/or their tinnitus. PMID:28970812

Probabilistic BPRRC: Robust Change Detection against Illumination Changes and Background Movements

NASA Astrophysics Data System (ADS)

Yokoi, Kentaro

This paper presents Probabilistic Bi-polar Radial Reach Correlation (PrBPRRC), a change detection method that is robust against illumination changes and background movements. Most of the traditional change detection methods are robust against either illumination changes or background movements; BPRRC is one of the illumination-robust change detection methods. We introduce a probabilistic background texture model into BPRRC and add the robustness against background movements including foreground invasions such as moving cars, walking people, swaying trees, and falling snow. We show the superiority of PrBPRRC in the environment with illumination changes and background movements by using three public datasets and one private dataset: ATON Highway data, Karlsruhe traffic sequence data, PETS 2007 data, and Walking-in-a-room data.

How Long Is the Shadow? The Relationships of Family Background to Selected Adult Outcomes: Results from PIAAC

ERIC Educational Resources Information Center

Braun, Henry

2018-01-01

Background: Ongoing interest in the relationships between family background and adult outcomes is motivated by concerns regarding the intergenerational transmission of advantage/disadvantage. Currently all countries are far from achieving the ideal that all individuals, irrespective of their starting points or their demographic characteristics,…

Stroke-model-based character extraction from gray-level document images.

PubMed

Ye, X; Cheriet, M; Suen, C Y

2001-01-01

Global gray-level thresholding techniques such as Otsu's method, and local gray-level thresholding techniques such as edge-based segmentation or the adaptive thresholding method are powerful in extracting character objects from simple or slowly varying backgrounds. However, they are found to be insufficient when the backgrounds include sharply varying contours or fonts in different sizes. A stroke-model is proposed to depict the local features of character objects as double-edges in a predefined size. This model enables us to detect thin connected components selectively, while ignoring relatively large backgrounds that appear complex. Meanwhile, since the stroke width restriction is fully factored in, the proposed technique can be used to extract characters in predefined font sizes. To process large volumes of documents efficiently, a hybrid method is proposed for character extraction from various backgrounds. Using the measurement of class separability to differentiate images with simple backgrounds from those with complex backgrounds, the hybrid method can process documents with different backgrounds by applying the appropriate methods. Experiments on extracting handwriting from a check image, as well as machine-printed characters from scene images demonstrate the effectiveness of the proposed model.

The Chandra Source Catalog: X-ray Aperture Photometry

NASA Astrophysics Data System (ADS)

Kashyap, Vinay; Primini, F. A.; Glotfelty, K. J.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, I. N.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-09-01

The Chandra Source Catalog (CSC) represents a reanalysis of the entire ACIS and HRC imaging observations over the 9-year Chandra mission. We describe here the method by which fluxes are measured for detected sources. Source detection is carried out on a uniform basis, using the CIAO tool wavdetect. Source fluxes are estimated post-facto using a Bayesian method that accounts for background, spatial resolution effects, and contamination from nearby sources. We use gamma-function prior distributions, which could be either non-informative, or in case there exist previous observations of the same source, strongly informative. The current implementation is however limited to non-informative priors. The resulting posterior probability density functions allow us to report the flux and a robust credible range on it.

Optimal 2D-SIM reconstruction by two filtering steps with Richardson-Lucy deconvolution.

PubMed

Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl

2016-11-16

Structured illumination microscopy relies on reconstruction algorithms to yield super-resolution images. Artifacts can arise in the reconstruction and affect the image quality. Current reconstruction methods involve a parametrized apodization function and a Wiener filter. Empirically tuning the parameters in these functions can minimize artifacts, but such an approach is subjective and produces volatile results. We present a robust and objective method that yields optimal results by two straightforward filtering steps with Richardson-Lucy-based deconvolutions. We provide a resource to identify artifacts in 2D-SIM images by analyzing two main reasons for artifacts, out-of-focus background and a fluctuating reconstruction spectrum. We show how the filtering steps improve images of test specimens, microtubules, yeast and mammalian cells.

Optimal 2D-SIM reconstruction by two filtering steps with Richardson-Lucy deconvolution

NASA Astrophysics Data System (ADS)

Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl

2016-11-01

Structured illumination microscopy relies on reconstruction algorithms to yield super-resolution images. Artifacts can arise in the reconstruction and affect the image quality. Current reconstruction methods involve a parametrized apodization function and a Wiener filter. Empirically tuning the parameters in these functions can minimize artifacts, but such an approach is subjective and produces volatile results. We present a robust and objective method that yields optimal results by two straightforward filtering steps with Richardson-Lucy-based deconvolutions. We provide a resource to identify artifacts in 2D-SIM images by analyzing two main reasons for artifacts, out-of-focus background and a fluctuating reconstruction spectrum. We show how the filtering steps improve images of test specimens, microtubules, yeast and mammalian cells.

Image reconstruction of dynamic infrared single-pixel imaging system

NASA Astrophysics Data System (ADS)

Tong, Qi; Jiang, Yilin; Wang, Haiyan; Guo, Limin

2018-03-01

Single-pixel imaging technique has recently received much attention. Most of the current single-pixel imaging is aimed at relatively static targets or the imaging system is fixed, which is limited by the number of measurements received through the single detector. In this paper, we proposed a novel dynamic compressive imaging method to solve the imaging problem, where exists imaging system motion behavior, for the infrared (IR) rosette scanning system. The relationship between adjacent target images and scene is analyzed under different system movement scenarios. These relationships are used to build dynamic compressive imaging models. Simulation results demonstrate that the proposed method can improve the reconstruction quality of IR image and enhance the contrast between the target and the background in the presence of system movement.

Current strategies with 1-stage prosthetic breast reconstruction

PubMed Central

2015-01-01

Background 1-stage prosthetic breast reconstruction is gaining traction as a preferred method of breast reconstruction in select patients who undergo mastectomy for cancer or prevention. Methods Critical elements to the procedure including patient selection, technique, surgical judgment, and postoperative care were reviewed. Results Outcomes series reveal that in properly selected patients, direct-to-implant (DTI) reconstruction has similar low rates of complications and high rates of patient satisfaction compared to traditional 2-stage reconstruction. Conclusions 1-stage prosthetic breast reconstruction may be the procedure of choice in select patients undergoing mastectomy. Advantages include the potential for the entire reconstructive process to be complete in one surgery, the quick return to normal activities, and lack of donor site morbidity. PMID:26005643

DNA-based identification of spices: DNA isolation, whole genome amplification, and polymerase chain reaction.

PubMed

Focke, Felix; Haase, Ilka; Fischer, Markus

2011-01-26

Usually spices are identified morphologically using simple methods like magnifying glasses or microscopic instruments. On the other hand, molecular biological methods like the polymerase chain reaction (PCR) enable an accurate and specific detection also in complex matrices. Generally, the origins of spices are plants with diverse genetic backgrounds and relationships. The processing methods used for the production of spices are complex and individual. Consequently, the development of a reliable DNA-based method for spice analysis is a challenging intention. However, once established, this method will be easily adapted to less difficult food matrices. In the current study, several alternative methods for the isolation of DNA from spices have been developed and evaluated in detail with regard to (i) its purity (photometric), (ii) yield (fluorimetric methods), and (iii) its amplifiability (PCR). Whole genome amplification methods were used to preamplify isolates to improve the ratio between amplifiable DNA and inhibiting substances. Specific primer sets were designed, and the PCR conditions were optimized to detect 18 spices selectively. Assays of self-made spice mixtures were performed to proof the applicability of the developed methods.

Characterization of background concentrations of contaminants using a mixture of normal distributions.

PubMed

Qian, Song S; Lyons, Regan E

2006-10-01

We present a Bayesian approach for characterizing background contaminant concentration distributions using data from sites that may have been contaminated. Our method, focused on estimation, resolves several technical problems of the existing methods sanctioned by the U.S. Environmental Protection Agency (USEPA) (a hypothesis testing based method), resulting in a simple and quick procedure for estimating background contaminant concentrations. The proposed Bayesian method is applied to two data sets from a federal facility regulated under the Resource Conservation and Restoration Act. The results are compared to background distributions identified using existing methods recommended by the USEPA. The two data sets represent low and moderate levels of censorship in the data. Although an unbiased estimator is elusive, we show that the proposed Bayesian estimation method will have a smaller bias than the EPA recommended method.

The Pedestrian Detection Method Using an Extension Background Subtraction about the Driving Safety Support Systems

NASA Astrophysics Data System (ADS)

Muranaka, Noriaki; Date, Kei; Tokumaru, Masataka; Imanishi, Shigeru

In recent years, the traffic accident occurs frequently with explosion of traffic density. Therefore, we think that the safe and comfortable transportation system to defend the pedestrian who is the traffic weak is necessary. First, we detect and recognize the pedestrian (the crossing person) by the image processing. Next, we inform all the drivers of the right or left turn that the pedestrian exists by the sound and the image and so on. By prompting a driver to do safe driving in this way, the accident to the pedestrian can decrease. In this paper, we are using a background subtraction method for the movement detection of the movement object. In the background subtraction method, the update method in the background was important, and as for the conventional way, the threshold values of the subtraction processing and background update were identical. That is, the mixing rate of the input image and the background image of the background update was a fixation value, and the fine tuning which corresponded to the environment change of the weather was difficult. Therefore, we propose the update method of the background image that the estimated mistake is difficult to be amplified. We experiment and examines in the comparison about five cases of sunshine, cloudy, evening, rain, sunlight change, except night. This technique can set separately the threshold values of the subtraction processing and background update processing which suited the environmental condition of the weather and so on. Therefore, the fine tuning becomes possible freely in the mixing rate of the input image and the background image of the background update. Because the setting of the parameter which suited an environmental condition becomes important to minimize mistaking percentage, we examine about the setting of a parameter.

Assessment of Complement Activation by Nanoparticles: Development of a SPR Based Method and Comparison with Current High Throughput Methods.

PubMed

Coty, Jean-Baptiste; Noiray, Magali; Vauthier, Christine

2018-04-26

A Surface Plasmon Resonance chip (SPR) was developed to study the activation of complement system triggered by nanomaterials in contact with human serum, which is an important concern today to warrant safety of nanomedicines. The developed chip was tested for its specificity in complex medium and its longevity of use. It was then employed to assess the release of complement fragments upon incubation of nanoparticles in serum. A comparison was made with other current methods assessing complement activation (μC-IE, ELISA). The SPR chip was found to give a consistent response for C3a release upon activation by nanoparticles. Results were similar to those obtained by μC-IE. However, ELISA detection of iC3b fragments showed an explained high non-specific background. The impact of sample preparation preceding the analysis was assessed with the newly develop SPR method. The removal of nanoparticles before analysis showed an important modification in the obtained response, possibly leading to false negative results. The SPR chip developed in this work allows for an automated assessment of complement activation triggered by nanoparticles with possibility of multiplexed analysis. The design of the chip proved to give consistent results of complement activation by nanoparticles.

Students' perceptions of the admissions process for a program for internationally-trained dentists

NASA Astrophysics Data System (ADS)

King, Patricia Ann

This study is designed to analyze the students' perceptions of the application process for a foreign-trained dental program. The goal was to add to the knowledge base the views of students who have experienced the application process of this type of program. Using a quantitative approach, the method of data collection was through a link to an online Likert survey which was emailed to graduates, first-year and second-year current students of the International Dental Studies (IDS) program at the University of the Pacific Arthur A. Dugoni School of Dentistry. Respondents were students who had experienced the IDS application process and had been accepted into the program. The study identified three topics: background, motivation and perception of fairness. The background information identified whether the participant was male/female and whether they were a current first-/second-year student or a graduate of the program. Motivation for applying was identified through questions about knowing someone who was in or had completed the program, and/or applied because of the program's reputation. Perception of fairness was determined by asking how the student felt about each required element of the process. By using structure based upon construct, which provides the researcher with a methodical review and configuration of the information, the study found that students had some views about application elements that, at times, conflicted with school's requirements. However, in general, the students felt the school was requiring the right elements for their application and were, therefore, basing their acceptance decisions on the correct requisites.

It's like a juggling act: rheumatoid arthritis patient perspectives on daily life and flare while on current treatment regimes.

PubMed

Flurey, Caroline A; Morris, Marianne; Richards, Pam; Hughes, Rodney; Hewlett, Sarah

2014-04-01

The objective of this study was to explore patients' experiences of RA daily life while on modern treatments. The methods of this study comprised semi-structured interviews with 15 RA patients, analysed using inductive thematic analysis. Four themes suggest patients experience life with RA along a continuum from RA in the background to the foreground of their lives, underpinned by constant actions to maintain balance. Living with RA in the background shows patients experience continuous, daily symptoms, which they mediate through micromanagement (mediating the impact of RA on daily life), while learning to incorporate RA into their identity (redefining me). RA moving into the foreground shows patients experience fluctuating symptoms (unwelcome reminders) that may or may not lead to a flare (trying to make sense of fluctuation). Dealing with RA in the foreground shows how patients attempt to manage RA flares (trying to regain control) and decide to seek medical help only after feeling they are losing control. Patients employ a stepped approach to self-management (mediation ladder) as symptoms increase, with seeking medical help often seen as the last resort. Patients seek to find a balance between managing their fluctuating RA and living their daily lives. Patients move back and forth along a continuum of RA in the background vs the foreground by balancing self-management of symptoms and everyday life. Clinicians need to appreciate that daily micromanagement is needed, even on current treatment regimes. Further research is needed to quantify the level and impact of daily symptoms and identify barriers and facilitators to seeking help.

Background suppression of infrared small target image based on inter-frame registration

NASA Astrophysics Data System (ADS)

Ye, Xiubo; Xue, Bindang

2018-04-01

We propose a multi-frame background suppression method for remote infrared small target detection. Inter-frame information is necessary when the heavy background clutters make it difficult to distinguish real targets and false alarms. A registration procedure based on points matching in image patches is used to compensate the local deformation of background. Then the target can be separated by background subtraction. Experiments show our method serves as an effective preliminary of target detection.

Isolation and culture of adult mouse vestibular nucleus neurons

PubMed

Him, Aydın; Altuntaş, Serap; Öztürk, Gürkan; Erdoğan, Ender; Cengiz, Nureddin

2017-12-19

Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibular nucleus (MVN) from adult mice and describe its morphological and electrophysiological properties.Materials and methods: Vestibular nucleus neurons were mechanically and enzymatically isolated and cultured using a defined medium with known growth factors. Cell survival was measured with propidium iodide, and electrophysiological properties were investigated with current-clamp recording.Results: Vestibular neurons grew neurites in cultures, gaining adult-like morphological properties, and stayed viable for 3 days in culture. Adding bovine calf serum, nerve growth factor, or insulin-like growth factor into the culture medium enhanced neuronal viability. Current-clamp recording of the cultured neurons revealed tonic and phasic-type neurons with similar input resistance, resting membrane potential, action potential amplitude, and duration. Conclusion: Vestibular neurons from adult mice can be cultured, and regenerate axons in a medium containing appropriate growth factors. Culturing adult vestibular neurons provides a new method to study age-related pathologies of the vestibular system.

Data fusion and photometric restoration

NASA Astrophysics Data System (ADS)

Pirzkal, Norbert; Hook, Richard N.

2001-11-01

The current generation of 8-10m optical ground-based telescopes have a symbiotic relationship with space telescopes. For direct imaging in the optical the former can collect photons relatively cheaply but the latter can still achieve, even in the era of adaptive optics, significantly higher spatial resolution, point-spread function stability and astrometric fidelity over fields of a few arcminutes. The large archives of HST imaging already in place, when combined with the ease of access to ground-based data afforded by the virtual observatory currently under development, will make space-ground data fusion a powerful tool for the future. We describe a photometric image restoration method that we have developed which allows the efficient and accurate use of high-resolution space imaging of crowded fields to extract high quality photometry from very crowded ground-based images. We illustrate the method using HST and ESO VLT/FORS imaging of a globular cluster and demonstrate quantitatively the photometric measurements quality that can achieved using the data fusion approach instead of just using data from just one telescope. This method can handle most of the common difficulties encountered when attempting this problem such as determining the geometric mapping to the requisite precision, deriving the PSF and the background.

An improved approach for the segmentation of starch granules in microscopic images

PubMed Central

2010-01-01

Background Starches are the main storage polysaccharides in plants and are distributed widely throughout plants including seeds, roots, tubers, leaves, stems and so on. Currently, microscopic observation is one of the most important ways to investigate and analyze the structure of starches. The position, shape, and size of the starch granules are the main measurements for quantitative analysis. In order to obtain these measurements, segmentation of starch granules from the background is very important. However, automatic segmentation of starch granules is still a challenging task because of the limitation of imaging condition and the complex scenarios of overlapping granules. Results We propose a novel method to segment starch granules in microscopic images. In the proposed method, we first separate starch granules from background using automatic thresholding and then roughly segment the image using watershed algorithm. In order to reduce the oversegmentation in watershed algorithm, we use the roundness of each segment, and analyze the gradient vector field to find the critical points so as to identify oversegments. After oversegments are found, we extract the features, such as the position and intensity of the oversegments, and use fuzzy c-means clustering to merge the oversegments to the objects with similar features. Experimental results demonstrate that the proposed method can alleviate oversegmentation of watershed segmentation algorithm successfully. Conclusions We present a new scheme for starch granules segmentation. The proposed scheme aims to alleviate the oversegmentation in watershed algorithm. We use the shape information and critical points of gradient vector flow (GVF) of starch granules to identify oversegments, and use fuzzy c-mean clustering based on prior knowledge to merge these oversegments to the objects. Experimental results on twenty microscopic starch images demonstrate the effectiveness of the proposed scheme. PMID:21047380

Oxygen Activation and Photoelectrochemical Oxidation on Oxide Surfaces

DTIC Science & Technology

2013-12-04

electrolysis followed by product determination from mass spectroscopy showed that acetophenone was produced with a 95% Faradaic efficiency. The H/D kinetic...vs. NHE) 10 electrode: scan rate, 100mV/s. (b) Plot of catalytic currents during electrolysis at −1.38 V, icat (background subtracted), vs...controlled potential electrolysis at 3.0 V at two boron doped diamond electrodes (~0.85 cm2). Red line: background current without added catalyst

Evaluation of Plume Divergence and Facility Effects on Far-Field Faraday Probe Current Density Profiles

DTIC Science & Technology

2009-09-01

elevated background pressure, compared nude Faraday probe designs, and evaluated design modifications to minimize uncertainty due to charge exchange...evaluated Faraday probe design and facility background pressure on collected ion current. A comparison of two nude Faraday probe designs concluded...140.5 Plasma potential in the region surrounding a nude Faraday probe has been measured to study the possibility of probe bias voltage acting as a

The MAJORANA DEMONSTRATOR for 0νββ: Current Status and Future Plans

NASA Astrophysics Data System (ADS)

Green, M. P.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.

The MAJORANA DEMONSTRATOR will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of no more than 3 counts in the 0νββ-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.

The Majorana Demonstrator for 0νββ: Current Status and Future Plans

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

Green, Matthew P.; Avignone, F. T.; Bertrand, Jr, Fred E

2015-01-01

The Majorana Demonstrator will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of nomore » more than 3cnts/(ROI-t-y). The current status of the Demonstrator is discussed, as are plans for its completion.« less

Visualization of medical data based on EHR standards.

PubMed

Kopanitsa, G; Hildebrand, C; Stausberg, J; Englmeier, K H

2013-01-01

To organize an efficient interaction between a doctor and an EHR the data has to be presented in the most convenient way. Medical data presentation methods and models must be flexible in order to cover the needs of the users with different backgrounds and requirements. Most visualization methods are doctor oriented, however, there are indications that the involvement of patients can optimize healthcare. The research aims at specifying the state of the art of medical data visualization. The paper analyzes a number of projects and defines requirements for a generic ISO 13606 based data visualization method. In order to do so it starts with a systematic search for studies on EHR user interfaces. In order to identify best practices visualization methods were evaluated according to the following criteria: limits of application, customizability, re-usability. The visualization methods were compared by using specified criteria. The review showed that the analyzed projects can contribute knowledge to the development of a generic visualization method. However, none of them proposed a model that meets all the necessary criteria for a re-usable standard based visualization method. The shortcomings were mostly related to the structure of current medical concept specifications. The analysis showed that medical data visualization methods use hardcoded GUI, which gives little flexibility. So medical data visualization has to turn from a hardcoded user interface to generic methods. This requires a great effort because current standards are not suitable for organizing the management of visualization data. This contradiction between a generic method and a flexible and user-friendly data layout has to be overcome.

Background Characterization for Thermal Ion Release Experiments with 224Ra

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

Kwong, H.; /Stanford U., Phys. Dept.; Rowson, P.

The Enriched Xenon Observatory for neutrinoless double beta decay uses {sup 136}Ba identification as a means for verifying the decay's occurrence in {sup 136}Xe. A current challenge is the release of Ba ions from the Ba extraction probe, and one possible solution is to heat the probe to high temperatures to release the ions. The investigation of this method requires a characterization of the alpha decay background in our test apparatus, which uses a {sup 228}Th source that produces {sup 224}Ra daughters, the ionization energies of which are similar to those of Ba. For this purpose, we ran a backgroundmore » count with our apparatus maintained at a vacuum, and then three counts with the apparatus filled with Xe gas. We were able to match up our alpha spectrum in vacuum with the known decay scheme of {sup 228}Th, while the spectrum in xenon gas had too many unresolved ambiguities for an accurate characterization. We also found that the alpha decays occurred at a near-zero rate both in vacuum and in xenon gas, which indicates that the rate was determined by {sup 228}Th decays. With these background measurements, we can in the future make a more accurate measurement of the temperature dependency of the ratio of ions to neutral atoms released from the hot surface of the probe, which may lead to a successful method of Ba ion release.« less

Curriculum leadership in the postgraduate: Gap between current and optimal status

PubMed Central

Avizhgan, Maryam; Jafari, Ebrahim Mirshah; Nasr, Ahmad Reza; Changiz, Tahereh

2015-01-01

Background: Identifying the strengths and weakness points is one of the effective methods to analyze current status, and prioritizing actions based on the gap between current and optimal status is necessary for short-term and long-term planning in departments and colleges. The aim of this study was to determine the gap between current and optimal status of curriculum leadership in the postgraduate courses in two Iranian universities. Materials and Methods: In this cross-sectional study, a sample of 212 faculty members from the two Iranian universities (one medical and one nonmedical) was randomly selected through stratified random sampling method. Data were collected by using a researcher-made questionnaire, with 55 items categorized in four areas of main dimensions in curriculum leadership. The validity of the questionnaire was determined by curriculum studies scholars, and the reliability was confirmed as the Cronbach's alpha calculated 0.969. Data were analyzed using descriptive and inferential statistics according to the variables. Results: There was a gap in all dimensions and roles. The maximum gap (−1.70) with the highest frequency (98%) were related to “improving the educational atmosphere” dimension. As for items, the maximum gap (−2.41) was related to “society needs and expectations and the labor market” in “curriculum development and revision” dimension. Conclusion: The negative gap between all dimensions of curriculum leadership implies faculty members’ dissatisfaction. Curriculum leadership at universities, colleges and departments of the study in all aspects need to be improved. Hence, it is necessary for managers to make use of the viewpoints of the faculty members to decrease the gap. PMID:26109996

Peripheral nerve magnetic stimulation: influence of tissue non-homogeneity

PubMed Central

Krasteva, Vessela TZ; Papazov, Sava P; Daskalov, Ivan K

2003-01-01

Background Peripheral nerves are situated in a highly non-homogeneous environment, including muscles, bones, blood vessels, etc. Time-varying magnetic field stimulation of the median and ulnar nerves in the carpal region is studied, with special consideration of the influence of non-homogeneities. Methods A detailed three-dimensional finite element model (FEM) of the anatomy of the wrist region was built to assess the induced currents distribution by external magnetic stimulation. The electromagnetic field distribution in the non-homogeneous domain was defined as an internal Dirichlet problem using the finite element method. The boundary conditions were obtained by analysis of the vector potential field excited by external current-driven coils. Results The results include evaluation and graphical representation of the induced current field distribution at various stimulation coil positions. Comparative study for the real non-homogeneous structure with anisotropic conductivities of the tissues and a mock homogeneous media is also presented. The possibility of achieving selective stimulation of either of the two nerves is assessed. Conclusion The model developed could be useful in theoretical prediction of the current distribution in the nerves during diagnostic stimulation and therapeutic procedures involving electromagnetic excitation. The errors in applying homogeneous domain modeling rather than real non-homogeneous biological structures are demonstrated. The practical implications of the applied approach are valid for any arbitrary weakly conductive medium. PMID:14693034

Beyond Blood Culture and Gram Stain Analysis: A Review of Molecular Techniques for the Early Detection of Bacteremia in Surgical Patients

PubMed Central

Kaplan, Heidi B.; Dua, Anahita; Litwin, Douglas B.; Ambrose, Catherine G.; Moore, Laura J.; Murray, COL Clinton K.; Wade, Charles E.; Holcomb, John B.

2016-01-01

Abstract Background: Sepsis from bacteremia occurs in 250,000 cases annually in the United States, has a mortality rate as high as 60%, and is associated with a poorer prognosis than localized infection. Because of these high figures, empiric antibiotic administration for patients with systemic inflammatory response syndrome (SIRS) and suspected infection is the second most common indication for antibiotic administration in intensive care units (ICU)s. However, overuse of empiric antibiotics contributes to the development of opportunistic infections, antibiotic resistance, and the increase in multi-drug-resistant bacterial strains. The current method of diagnosing and ruling out bacteremia is via blood culture (BC) and Gram stain (GS) analysis. Methods: Conventional and molecular methods for diagnosing bacteremia were reviewed and compared. The clinical implications, use, and current clinical trials of polymerase chain reaction (PCR)-based methods to detect bacterial pathogens in the blood stream were detailed. Results: BC/GS has several disadvantages. These include: some bacteria do not grow in culture media; others do not GS appropriately; and cultures can require up to 5 d to guide or discontinue antibiotic treatment. PCR-based methods can be potentially applied to detect rapidly, accurately, and directly microbes in human blood samples. Conclusions: Compared with the conventional BC/GS, particular advantages to molecular methods (specifically, PCR-based methods) include faster results, leading to possible improved antibiotic stewardship when bacteremia is not present. PMID:26918696

Predicting Curriculum and Test Performance at Age 7 Years from Pupil Background, Baseline Skills and Phonological Awareness at Age 5

ERIC Educational Resources Information Center

Savage, R.; Carless, S.

2004-01-01

Background: Phonological awareness tests are known to be amongst the best predictors of literacy; however their predictive validity alongside current school screening practice (baseline assessment, pupil background data) and to National Curricular outcome measures is unknown. Aim: We explored the validity of phonological awareness and orthographic…

Ultra-sensitive in-situ detection of near-infrared persistent luminescent tracer nanoagents in crude oil-water mixtures.

PubMed

Chuang, Yen-Jun; Liu, Feng; Wang, Wei; Kanj, Mazen Y; Poitzsch, Martin E; Pan, Zhengwei

2016-06-15

Current fluorescent nanoparticles-based tracer sensing techniques for oilfield applications suffer from insufficient sensitivity, with the tracer detection limit typically at the several hundred ppm level in untreated oil/water mixtures, which is mainly caused by the interference of the background fluorescence from the organic residues in crude oil under constant external excitation. Here we report the use of a persistent luminescence phenomenon, which enables an external excitation-free and thus background fluorescence-free measurement condition, for ultrahigh-sensitivity crude oil sensing. By using LiGa5O8:Cr(3+) near-infrared persistent luminescent nanoparticles as a tracer nanoagent, we achieved a tracer detection limit at the single-digit ppb level (down to 1 ppb concentration of nanoparticles) in high oil fraction (up to 65 wt.%) oil/water mixtures via a convenient, CCD camera-based imaging technique without any pretreatment or phase separation of the fluid samples. This detection limit is about four to five orders of magnitude lower than that obtained using conventional spectral methods. This study introduces a new type of tracer nanoagents and a new detection method for water tracer sensing in oil reservoir characterization and management.

Single-shot ADC imaging for fMRI.

PubMed

Song, Allen W; Guo, Hua; Truong, Trong-Kha

2007-02-01

It has been suggested that apparent diffusion coefficient (ADC) contrast can be sensitive to cerebral blood flow (CBF) changes during brain activation. However, current ADC imaging techniques have an inherently low temporal resolution due to the requirement of multiple acquisitions with different b-factors, as well as potential confounds from cross talk between the deoxyhemoglobin-induced background gradients and the externally applied diffusion-weighting gradients. In this report a new method is proposed and implemented that addresses these two limitations. Specifically, a single-shot pulse sequence that sequentially acquires one gradient-echo (GRE) and two diffusion-weighted spin-echo (SE) images was developed. In addition, the diffusion-weighting gradient waveform was numerically optimized to null the cross terms with the deoxyhemoglobin-induced background gradients to fully isolate the effect of diffusion weighting from that of oxygenation-level changes. The experimental results show that this new single-shot method can acquire ADC maps with sufficient signal-to-noise ratio (SNR), and establish its practical utility in functional MRI (fMRI) to complement the blood oxygenation level-dependent (BOLD) technique and provide differential sensitivity for different vasculatures to better localize neural activity originating from the small vessels. Copyright (c) 2007 Wiley-Liss, Inc.

Report on FY15 alloy 617 code rules development

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

Sham, Sam; Jetter, Robert I; Hollinger, Greg

2015-09-01

Due to its strength at very high temperatures, up to 950°C (1742°F), Alloy 617 is the reference construction material for structural components that operate at or near the outlet temperature of the very high temperature gas-cooled reactors. However, the current rules in the ASME Section III, Division 5 Subsection HB, Subpart B for the evaluation of strain limits and creep-fatigue damage using simplified methods based on elastic analysis have been deemed inappropriate for Alloy 617 at temperatures above 650°C (1200°F) (Corum and Brass, Proceedings of ASME 1991 Pressure Vessels and Piping Conference, PVP-Vol. 215, p.147, ASME, NY, 1991). The rationalemore » for this exclusion is that at higher temperatures it is not feasible to decouple plasticity and creep, which is the basis for the current simplified rules. This temperature, 650°C (1200°F), is well below the temperature range of interest for this material for the high temperature gas-cooled reactors and the very high temperature gas-cooled reactors. The only current alternative is, thus, a full inelastic analysis requiring sophisticated material models that have not yet been formulated and verified. To address these issues, proposed code rules have been developed which are based on the use of elastic-perfectly plastic (EPP) analysis methods applicable to very high temperatures. The proposed rules for strain limits and creep-fatigue evaluation were initially documented in the technical literature (Carter, Jetter and Sham, Proceedings of ASME 2012 Pressure Vessels and Piping Conference, papers PVP 2012 28082 and PVP 2012 28083, ASME, NY, 2012), and have been recently revised to incorporate comments and simplify their application. Background documents have been developed for these two code cases to support the ASME Code committee approval process. These background documents for the EPP strain limits and creep-fatigue code cases are documented in this report.« less

Speaker-independent phoneme recognition with a binaural auditory image model

NASA Astrophysics Data System (ADS)

Francis, Keith Ivan

1997-09-01

This dissertation presents phoneme recognition techniques based on a binaural fusion of outputs of the auditory image model and subsequent azimuth-selective phoneme recognition in a noisy environment. Background information concerning speech variations, phoneme recognition, current binaural fusion techniques and auditory modeling issues is explained. The research is constrained to sources in the frontal azimuthal plane of a simulated listener. A new method based on coincidence detection of neural activity patterns from the auditory image model of Patterson is used for azimuth-selective phoneme recognition. The method is tested in various levels of noise and the results are reported in contrast to binaural fusion methods based on various forms of correlation to demonstrate the potential of coincidence- based binaural phoneme recognition. This method overcomes smearing of fine speech detail typical of correlation based methods. Nevertheless, coincidence is able to measure similarity of left and right inputs and fuse them into useful feature vectors for phoneme recognition in noise.

An Examination of Past and Current Influences of Rurality on Lesbians' Overweight/Obesity Risks.

PubMed

Barefoot, K Nikki; Warren, Jacob C; Smalley, K Bryant

2015-06-01

The purpose of our study was to separately examine past (i.e., rural or non-rural background) and present (i.e., current rural or urban location) influences of rurality on the weight status and diet/exercise behaviors of lesbians. A total of 895 lesbians participated in the online study. Participants were surveyed regarding their rurality status, weight/height, and diet/exercise patterns. A 2×2 (location×background) ANCOVA was conducted to explore influences of rurality on body mass index (BMI), while controlling for age, race, and education. Chi-square analyses were used to examine the relationship between dimensions of rurality and diet/exercise behaviors. There was a significant main effect of current location on BMI. No significant interaction between location and background on BMI was found nor was there a significant main effect of background. Lesbians currently living in rural areas were on average obese (M=30.61), with significantly higher BMIs than urban-residing lesbians (M=28.53). The only significant differences that emerged for lesbians' diet/exercise patterns were for current location-more rural-residing lesbians reported they never engage in exercise in comparison to their urban-residing counterparts, with a greater percentage of urban-residing lesbians reporting frequent exercise. Rural lesbians were also more likely to report a diet high in protein. Findings suggest that current rather than past influences of rurality may have a significant impact on lesbians' weight and diet/exercise behaviors and highlight significant obesity-related health disparities for rural-residing lesbians. These findings offer support for the development of culturally-appropriate healthy diet/exercise and weight promotion efforts that are accessible to rural lesbians.

Temperature-and field dependent characterization of a twisted stacked-tape cable

NASA Astrophysics Data System (ADS)

Barth, C.; Takayasu, M.; Bagrets, N.; Bayer, C. M.; Weiss, K.-P.; Lange, C.

2015-04-01

The twisted stacked-tape cable (TSTC) is one of the major high temperature superconductor cable concepts combining scalability, ease of fabrication and high current density making it a possible candidate as conductor for large scale magnets. To simulate the boundary conditions of such a magnets as well as the temperature dependence of TSTCs a 1.16 m long sample consisting of 40, 4 mm wide SuperPower REBCO tapes is characterized using the ‘FBI’ (force-field-current) superconductor test facility of the Institute for Technical Physics of the Karlsruhe Institute of Technology. In a first step, the magnetic background field is cycled while measuring the current carrying capabilities to determine the impact of Lorentz forces on the TSTC sample performance. In the first field cycle, the critical current of the TSTC sample is tested up to 12 T. A significant Lorentz force of up to 65.6 kN m-1 at the maximal magnetic background field of 12 T result in a 11.8% irreversible degradation of the current carrying capabilities. The degradation saturates (critical cable current of 5.46 kA at 4.2 K and 12 T background field) and does not increase in following field cycles. In a second step, the sample is characterized at different background fields (4-12 T) and surface temperatures (4.2-37.8 K) utilizing the variable temperature insert of the ‘FBI’ test facility. In a third step, the performance along the length of the sample is determined at 77 K, self-field. A 15% degradation is obtained for the central part of the sample which was within the high field region of the magnet during the in-field measurements.

Exogean: a framework for annotating protein-coding genes in eukaryotic genomic DNA

PubMed Central

Djebali, Sarah; Delaplace, Franck; Crollius, Hugues Roest

2006-01-01

Background Accurate and automatic gene identification in eukaryotic genomic DNA is more than ever of crucial importance to efficiently exploit the large volume of assembled genome sequences available to the community. Automatic methods have always been considered less reliable than human expertise. This is illustrated in the EGASP project, where reference annotations against which all automatic methods are measured are generated by human annotators and experimentally verified. We hypothesized that replicating the accuracy of human annotators in an automatic method could be achieved by formalizing the rules and decisions that they use, in a mathematical formalism. Results We have developed Exogean, a flexible framework based on directed acyclic colored multigraphs (DACMs) that can represent biological objects (for example, mRNA, ESTs, protein alignments, exons) and relationships between them. Graphs are analyzed to process the information according to rules that replicate those used by human annotators. Simple individual starting objects given as input to Exogean are thus combined and synthesized into complex objects such as protein coding transcripts. Conclusion We show here, in the context of the EGASP project, that Exogean is currently the method that best reproduces protein coding gene annotations from human experts, in terms of identifying at least one exact coding sequence per gene. We discuss current limitations of the method and several avenues for improvement. PMID:16925841

Within-Family Variability in Representations of Past Relationships With Parents

PubMed Central

Tucker, Corinna Jenkins; Fingerman, Karen; Savla, Jyoti

2009-01-01

Background We examined within-family variation in siblings’ memories of experiences with parents and their associations with current positive and negative affect. Methods Participants were 1,369 adults with at least 1 sibling, aged 26–74 years from 498 families in the MacArthur Study of Midlife in the United States (Mage = 47 years, 59% women, 94% White). Results There was considerable variability in recalled maternal and paternal treatment across the dimensions of affection (intraclass correlation coefficients [ICCs] 0.33 and 0.41, respectively), discipline (ICCs 0.39 and 0.43), and conflict (ICCs 0.24 and 0.26). In turn, recalled parental treatment, particularly affection, made unique contributions to current positive (ICC 0.12) and negative affect (ICC 0.08) over and above individual and familial level characteristics such as offspring demographic characteristics, extraversion and neuroticism, family structure, recalled early family environment, and parents' current status. Conclusions Results link adults' memories of experiences with their parents in childhood to their current well-being and highlight the importance of considering within-family models for family theory. PMID:19176488

Accounting for Dark Current Accumulated during Readout of Hubble's ACS/WFC Detectors

NASA Astrophysics Data System (ADS)

Ryon, Jenna E.; Grogin, Norman A.; Coe, Dan A.; ACS Team

2018-06-01

We investigate the properties of excess dark current accumulated during the 100-second full-frame readout of the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) detectors. This excess dark current, called "readout dark", gives rise to ambient background gradients and hot columns in each ACS/WFC image. While readout dark signal is removed from science images during the bias correction step in CALACS, the additional noise from the readout dark is currently not taken into account. We develop a method to estimate the readout dark noise properties in ACS/WFC observations. We update the error (ERR) extensions of superbias images to include the appropriate noise from the ambient readout dark gradient and stable hot columns. In recent data, this amounts to about 5 e-/pixel added variance in the rows farthest from the WFC serial registers, and about 7 to 30 e-/pixel added variance along the stable hot columns. We also flag unstable hot columns in the superbias data quality (DQ) extensions. The new reference file pipeline for ACS/WFC implements these updates to our superbias creation process.

Influences on adolescent self-esteem in multicultural Canadian secondary schools.

PubMed

Khanlou, Nazilla

2004-01-01

Abstract This study examined the global and current self-esteem levels of adolescents in a community sample of 550 secondary school students in Canada. A cross-sectional design and the survey method were used. Respondents' individual (age and gender) and environmental (cultural background, acculturating group, family circumstances, and perception of support) attributes were considered. Influences that promoted or challenged their current self-esteem were examined. Eighteen percent of respondents and 43.4% of respondents' parents were immigrants. When the Rosenberg Self-Esteem scale was used, 27.6% of respondents had the highest global self-esteem level; when the Current Self-Esteem scale was used, 12.7% had the highest current self-esteem level. A significant gender difference was found, with male adolescents having higher self-esteem. The results indicate that, although self-esteem promotion can benefit from lifestyle-oriented activities, its growth takes place in the larger context of adolescents' relationships, school-related experiences, achievements, and attitudes toward themselves. The study findings can contribute to mental health promotion strategies in multicultural and immigrant-receiving community settings.

Constraining Modified Theories of Gravity with Gravitational-Wave Stochastic Backgrounds

NASA Astrophysics Data System (ADS)

Maselli, Andrea; Marassi, Stefania; Ferrari, Valeria; Kokkotas, Kostas; Schneider, Raffaella

2016-08-01

The direct discovery of gravitational waves has finally opened a new observational window on our Universe, suggesting that the population of coalescing binary black holes is larger than previously expected. These sources produce an unresolved background of gravitational waves, potentially observable by ground-based interferometers. In this Letter we investigate how modified theories of gravity, modeled using the parametrized post-Einsteinian formalism, affect the expected signal, and analyze the detectability of the resulting stochastic background by current and future ground-based interferometers. We find the constraints that Advanced LIGO would be able to set on modified theories, showing that they may significantly improve the current bounds obtained from astrophysical observations of binary pulsars.

Disability and the impact of need for periodontal care on quality of life: A cross-sectional study

PubMed Central

AlAgl, Adel

2017-01-01

Objective The need for periodontal care may negatively impact daily life. We compared the need for periodontal care and its impact on daily life between disabled and healthy adults in the Eastern Province, Saudi Arabia. Methods In this cross-sectional study of 819 adults, a questionnaire was used to assess personal background factors; the impact of periodontitis on pain, avoiding foods, embarrassment, sleeplessness, work absence, and discontinuing daily activities; and risk factors (smoking, diabetes, toothbrushing, insurance, professional tooth cleaning, and dental visits). The outcome was clinically assessed need for periodontal care impacting daily life. The relationship between the outcome and risk factors adjusted for personal background and disability was assessed using ordinal regression. Results Healthy and disabled persons had a high need for periodontal care (66.8%). Current smokers had a higher likelihood and health-insured persons had a lower likelihood of need for periodontal care impacting daily life regardless of whether disability was considered. Conclusions Most adults needed periodontal care, and disabled persons experienced a greater impact on life. Current smokers and uninsured persons were more likely to need periodontal care impacting daily life. Our findings are important for the prevention of periodontitis through tobacco cessation and extending insurance coverage. PMID:28635358

A method of reducing background fluctuation in tunable diode laser absorption spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Rendi; Dong, Xiaozhou; Bi, Yunfeng; Lv, Tieliang

2018-03-01

Optical interference fringe is the main factor that leads to background fluctuation in gas concentration detection based on tunable diode laser absorption spectroscopy. The interference fringes are generated by multiple reflections or scatterings upon optical surfaces in optical path and make the background signal present an approximated sinusoidal oscillation. To reduce the fluctuation of the background, a method that combines dual tone modulation (DTM) with vibration reflector (VR) is proposed in this paper. The combination of DTM and VR can make the unwanted periodic interference fringes to be averaged out and the effectiveness of the method in reducing background fluctuation has been verified by simulation and real experiments in this paper. In the detection system based on the proposed method, the standard deviation (STD) value of the background signal is decreased to 0.0924 parts per million (ppm), which is reduced by a factor of 16 compared with that of wavelength modulation spectroscopy. The STD value of 0.0924 ppm corresponds to the absorption of 4 . 328 × 10-6Hz - 1 / 2 (with effective optical path length of 4 m and integral time of 0.1 s). Moreover, the proposed method presents a better stable performance in reducing background fluctuation in long time experiments.

Home and Health in the Third Age — Methodological Background and Descriptive Findings

PubMed Central

Kylén, Maya; Ekström, Henrik; Haak, Maria; Elmståhl, Sölve; Iwarsson, Susanne

2014-01-01

Background: The understanding of the complex relationship between the home environment, well-being and daily functioning in the third age is currently weak. The aim of this paper is to present the methodological background of the Home and Health in the Third Age Study, and describe a sample of men and women in relation to their home and health situation. Methods and Design: The study sample included 371 people aged 67–70, living in ordinary housing in the south of Sweden. Structured interviews and observations were conducted to collect data about objective and perceived aspects of home and health. Results: The majority of the participants were in good health and had few functional limitations. Women had more functional limitations and reported more symptoms than men. Environmental barriers were found in every home investigated; the most were found in the kitchen and hygiene area. Environmental barriers were more common in multi-family than in one-family dwellings. Discussion: This study will increase our knowledge on home and health dynamics among people in the third age. The results have potential to contribute to societal planning related to housing provision, home care and social services for senior citizens. PMID:25019267

Impact of local and non-local sources of pollution on background US Ozone: synergy of a low-earth orbiting and geostationary sounder constellation

NASA Astrophysics Data System (ADS)

Bowman, K. W.; Lee, M.

2015-12-01

Dramatic changes in the global distribution of emissions over the last decade have fundamentally altered source-receptor pollution impacts. A new generation of low-earth orbiting (LEO) sounders complimented by geostationary sounders over North America, Europe, and Asia providing a unique opportunity to quantify the current and future trajectory of emissions and their impact on global pollution. We examine the potential of this constellation of air quality sounders to quantify the role of local and non-local sources of pollution on background ozone in the US. Based upon an adjoint sensitivity method, we quantify the role synoptic scale transport of non-US pollution on US background ozone over months representative of different source-receptor relationships. This analysis allows us distinguish emission trajectories from megacities, e.g. Beijing, or regions, e.g., western China, from natural trends on downwind ozone. We subsequently explore how a combination of LEO and GEO observations could help quantify the balance of local emissions against changes in distant sources . These results show how this unprecedented new international ozone observing system can monitor the changing structure of emissions and their impact on global pollution.

Assessment of ambient background concentrations of elements in soil using combined survey and open-source data.

PubMed

Mikkonen, Hannah G; Clarke, Bradley O; Dasika, Raghava; Wallis, Christian J; Reichman, Suzie M

2017-02-15

Understanding ambient background concentrations in soil, at a local scale, is an essential part of environmental risk assessment. Where high resolution geochemical soil surveys have not been undertaken, soil data from alternative sources, such as environmental site assessment reports, can be used to support an understanding of ambient background conditions. Concentrations of metals/metalloids (As, Mn, Ni, Pb and Zn) were extracted from open-source environmental site assessment reports, for soils derived from the Newer Volcanics basalt, of Melbourne, Victoria, Australia. A manual screening method was applied to remove samples that were indicated to be contaminated by point sources and hence not representative of ambient background conditions. The manual screening approach was validated by comparison to data from a targeted background soil survey. Statistical methods for exclusion of contaminated samples from background soil datasets were compared to the manual screening method. The statistical methods tested included the Median plus Two Median Absolute Deviations, the upper whisker of a normal and log transformed Tukey boxplot, the point of inflection on a cumulative frequency plot and the 95th percentile. We have demonstrated that where anomalous sample results cannot be screened using site information, the Median plus Two Median Absolute Deviations is a conservative method for derivation of ambient background upper concentration limits (i.e. expected maximums). The upper whisker of a boxplot and the point of inflection on a cumulative frequency plot, were also considered adequate methods for deriving ambient background upper concentration limits, where the percentage of contaminated samples is <25%. Median ambient background concentrations of metals/metalloids in the Newer Volcanic soils of Melbourne were comparable to ambient background concentrations in Europe and the United States, except for Ni, which was naturally enriched in the basalt-derived soils of Melbourne. Copyright © 2016 Elsevier B.V. All rights reserved.

Ceramics in Restorative and Prosthetic DENTISTRY1

NASA Astrophysics Data System (ADS)

Kelly, J. Robert

1997-08-01

This review is intended to provide the ceramic engineer with information about the history and current use of ceramics in dentistry, contemporary research topics, and potential research agenda. Background material includes intra-oral design considerations, descriptions of ceramic dental components, and the origin, composition, and microstructure of current dental ceramics. Attention is paid to efforts involving net-shape processing, machining as a forming method, and the analysis of clinical failure. A rationale is presented for the further development of all-ceramic restorative systems. Current research topics receiving attention include microstructure/processing/property relationships, clinical failure mechanisms and in vitro testing, wear damage and wear testing, surface treatments, and microstructural modifications. The status of the field is critically reviewed with an eye toward future work. Significant improvements seem possible in the clinical use of ceramics based on engineering solutions derived from the study of clinically failed restorations, on the incorporation of higher levels of "biomimicry" in new systems, and on the synergistic developments in dental cements and adhesive dentin bonding.

Lithographed Superconducting Resonator Development for Next-Generation Frequency Multiplexing Readout of Transition-Edge Sensors

NASA Astrophysics Data System (ADS)

Faramarzi, F.; De Haan, T.; Kusaka, A.; Lee, A.; Neuhauser, B.; Plambeck, R.; Raum, C.; Suzuki, A.; Westbrook, B.

2018-03-01

Ground-based cosmic microwave background (CMB) experiments are undergoing a period of exponential growth. Current experiments are observing with 1000-10,000 detectors, and the next-generation experiment (CMB stage 4) is proposing to deploy approximately 500,000 detectors. This order of magnitude increase in detector count will require a new approach for readout electronics. We have developed superconducting resonators for next-generation frequency-domain multiplexing (fMUX) readout architecture. Our goal is to reduce the physical size of resonators, such that resonators and detectors can eventually be integrated on a single wafer. To reduce the size of these resonators, we have designed spiral inductors and interdigitated capacitors that resonate around 10-100 MHz, an order of magnitude higher frequency compared to current fMUX readout systems. The higher frequency leads to a wider bandwidth and would enable higher multiplexing factor than the current ˜ 50 detectors per readout channel. We will report on the simulation, fabrication method, characterization technique, and measurement of quality factor of these resonators.

Anophelism in a Former Malaria Area of Northeastern Spain

PubMed Central

Bueno-Marí, Rubén; Jiménez-Peydró, Ricardo

2013-01-01

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

Multivoxel MR Spectroscopy in Acute Ischemic Stroke:Comparison to the Stroke Protocol MRI

PubMed Central

Dani, Krishna A.; An, Li; Henning, Erica C.; Shen, Jun; Warach, Steven

2014-01-01

Background and Purpose Few patients with stroke have been imaged with MR spectroscopy (MRS) within the first few hours after onset. We compared data from current MRI protocols to MRS in subjects with ischemic stroke. Methods MRS was incorporated into the standard clinical MRI stroke protocol for subjects <24 hours after onset. MRI and clinical correlates for the metabolic data from MRS were sought. Results One hundred thirty-six MRS voxels from 32 subjects were analyzed. Lactate preceded the appearance of the lesion on diffusion-weighted imaging in some voxels but in others lagged behind it. Current protocols may predict up to 41% of the variance of MRS metabolites. Serum glucose concentration and time to maximum partially predicted the concentration of all major metabolites. Conclusion MRS may be helpful in acute stroke, especially for lactate detection when perfusion-weighted imaging is unavailable. Current MRI protocols do provide surrogate markers for some indices of metabolic activity. PMID:23091121

Styrene-Associated Health Outcomes at a Windblade Manufacturing Plant

PubMed Central

McCague, Anna-Binney; Cox-Ganser, Jean M.; Harney, Joshua M.; Alwis, K. Udeni; Blount, Benjamin C.; Cummings, Kristin J.; Edwards, Nicole; Kreiss, Kathleen

2015-01-01

Background Health risks of using styrene to manufacture windblades for the green energy sector are unknown. Methods Using data collected from 355 (73%) current windblade workers and regression analysis, we investigated associations between health outcomes and styrene exposure estimates derived from urinary styrene metabolites. Results The median current styrene exposure was 53.6 mg/g creatinine (interquartile range: 19.5–94.4). Color blindness in men and women (standardized morbidity ratios 2.3 and 16.6, respectively) was not associated with exposure estimates, but was the type previously reported with styrene. Visual contrast sensitivity decreased and chest tightness increased (odds ratio 2.9) with increasing current exposure. Decreases in spirometric parameters and FeNO, and increases in the odds of wheeze and asthma-like symptoms (odds ratios 1.3 and 1.2, respectively) occurred with increasing cumulative exposure. Conclusions Despite styrene exposures below the recommended 400 mg/g creatinine, visual and respiratory effects indicate the need for additional preventative measures in this industry. PMID:26305283

Search for gravitational waves from LIGO-Virgo science run and data interpretation

NASA Astrophysics Data System (ADS)

Biswas, Rahul

Search for gravitational wave events was performed on data jointly taken during LIGO's fifth science run (S5) and Virgo's first science mn (VSR1). The data taken during this period was broken down into five separate months. I shall report the analysis performed on one of these months. Apart from the search, I shall describe the work related to estimation of rate based on the loudest event in the search. I shall demonstrate methods used in construction of rate intervals at 90% confidence level and combination of rates from multiple experiments of similar duration. To have confidence in our detection, accurate estimation of false alarm probability (F.A.P.) associated with the event candidate is required. Current false alarm estimation techniques limit our ability to measure the F.A.P. to about 1 in 100. I shall describe a method that significantly improves this estimate using information from multiple detectors. Besides accurate knowledge of F.A.P., detection is also dependent on our ability to distinguish real signals to those from noise. Several tests exist which use the quality of the signal to differentiate between real and noise signal. The chi-square test is one such computationally expensive test applied in our search; we shall understand the dependence of the chi-square parameter on the signal to noise ratio (SNR) for a given signal, which will help us to model the chi-square parameter based on SNR. The two detectors at Hanford, WA, H1(4km) and H2(2km), share the same vacuum system and hence their noise is correlated. Our present method of background estimation cannot capture this correlation and often underestimates the background when only H1 and H2 are operating. I shall describe a novel method of time reversed filtering to correctly estimate the background.

A generalised background correction algorithm for a Halo Doppler lidar and its application to data from Finland

DOE PAGES

Manninen, Antti J.; O'Connor, Ewan J.; Vakkari, Ville; ...

2016-03-03

Current commercially available Doppler lidars provide an economical and robust solution for measuring vertical and horizontal wind velocities, together with the ability to provide co- and cross-polarised backscatter profiles. The high temporal resolution of these instruments allows turbulent properties to be obtained from studying the variation in radial velocities. However, the instrument specifications mean that certain characteristics, especially the background noise behaviour, become a limiting factor for the instrument sensitivity in regions where the aerosol load is low. Turbulent calculations require an accurate estimate of the contribution from velocity uncertainty estimates, which are directly related to the signal-to-noise ratio. Anymore » bias in the signal-to-noise ratio will propagate through as a bias in turbulent properties. In this paper we present a method to correct for artefacts in the background noise behaviour of commercially available Doppler lidars and reduce the signal-to-noise ratio threshold used to discriminate between noise, and cloud or aerosol signals. We show that, for Doppler lidars operating continuously at a number of locations in Finland, the data availability can be increased by as much as 50 % after performing this background correction and subsequent reduction in the threshold. Furthermore the reduction in bias also greatly improves subsequent calculations of turbulent properties in weak signal regimes.« less

A generalised background correction algorithm for a Halo Doppler lidar and its application to data from Finland

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

Manninen, Antti J.; O'Connor, Ewan J.; Vakkari, Ville

Current commercially available Doppler lidars provide an economical and robust solution for measuring vertical and horizontal wind velocities, together with the ability to provide co- and cross-polarised backscatter profiles. The high temporal resolution of these instruments allows turbulent properties to be obtained from studying the variation in radial velocities. However, the instrument specifications mean that certain characteristics, especially the background noise behaviour, become a limiting factor for the instrument sensitivity in regions where the aerosol load is low. Turbulent calculations require an accurate estimate of the contribution from velocity uncertainty estimates, which are directly related to the signal-to-noise ratio. Anymore » bias in the signal-to-noise ratio will propagate through as a bias in turbulent properties. In this paper we present a method to correct for artefacts in the background noise behaviour of commercially available Doppler lidars and reduce the signal-to-noise ratio threshold used to discriminate between noise, and cloud or aerosol signals. We show that, for Doppler lidars operating continuously at a number of locations in Finland, the data availability can be increased by as much as 50 % after performing this background correction and subsequent reduction in the threshold. Furthermore the reduction in bias also greatly improves subsequent calculations of turbulent properties in weak signal regimes.« less

Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT.

PubMed

Jang, J; Seo, J K

2015-06-01

This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

Health-related Quality of Life in Inflammatory Bowel Disease in a European-wide Population-based Cohort 10 Years After Diagnosis

PubMed Central

Høivik, Marte Lie; Langholz, Ebbe; Odes, Selwyn; Småstuen, Milada; Stockbrugger, Reinhold; Hoff, Geir; Moum, Bjørn; Bernklev, Tomm

2015-01-01

Background: Chronic inflammatory bowel disease (IBD) negatively affects the patient's health-related quality of life (HRQoL). Only a few population-based studies have compared the HRQoL of patients with the background population. The aim of this study was to evaluate the HRQoL in a European cohort of patients with ulcerative colitis and Crohn's disease 10 years after diagnosis (European Collaborative study group of Inflammatory Bowel Disease) compared with the national background population in each country and to assess possible country-specific differences. Methods: Patients with IBD from 7 European countries were invited to a follow-up visit 10 years after their diagnosis of IBD. We assessed their clinical and demographic data, including the generic HRQoL questionnaire short form health survey-36. Countrywise comparison with the background population was performed with z-scores using the Cohen's effect size index. Results: Seven hundred sixty-nine patients were eligible for the study. We registered statistically significant and clinically relevant decreases in the short form health survey-36 dimensional scores in patients with symptoms at the time of follow-up and for patients reporting sick leave during the previous year or having received disablement pension. In the Netherlands and Norway, there was a moderate difference between the patients with IBD and the background population for the general health dimension. Conclusions: Overall, the HRQoL was not reduced in the IBD cohort compared with the background populations. However, in addition to older age and female gender, current symptoms at follow-up, disablement pension, and sick leave during the previous year were significantly associated with a reduced HRQoL in patients with IBD. PMID:25569735

Advances in Assays and Analytical Approaches for Botulinum Toxin Detection

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

Grate, Jay W.; Ozanich, Richard M.; Warner, Marvin G.

2010-08-04

Methods to detect botulinum toxin, the most poisonous substance known, are reviewed. Current assays are being developed with two main objectives in mind: 1) to obtain sufficiently low detection limits to replace the mouse bioassay with an in vitro assay, and 2) to develop rapid assays for screening purposes that are as sensitive as possible while requiring an hour or less to process the sample an obtain the result. This review emphasizes the diverse analytical approaches and devices that have been developed over the last decade, while also briefly reviewing representative older immunoassays to provide background and context.

Doubling the spectrum of time-domain induced polarization by harmonic de-noising, drift correction, spike removal, tapered gating and data uncertainty estimation

NASA Astrophysics Data System (ADS)

Olsson, Per-Ivar; Fiandaca, Gianluca; Larsen, Jakob Juul; Dahlin, Torleif; Auken, Esben

2016-11-01

The extraction of spectral information in the inversion process of time-domain (TD) induced polarization (IP) data is changing the use of the TDIP method. Data interpretation is evolving from a qualitative description of the subsurface, able only to discriminate the presence of contrasts in chargeability parameters, towards a quantitative analysis of the investigated media, which allows for detailed soil- and rock-type characterization. Two major limitations restrict the extraction of the spectral information of TDIP data in the field: (i) the difficulty of acquiring reliable early-time measurements in the millisecond range and (ii) the self-potential background drift in the measured potentials distorting the shape of the late-time IP responses, in the second range. Recent developments in TDIP acquisition equipment have given access to full-waveform recordings of measured potentials and transmitted current, opening for a breakthrough in data processing. For measuring at early times, we developed a new method for removing the significant noise from power lines contained in the data through a model-based approach, localizing the fundamental frequency of the power-line signal in the full-waveform IP recordings. By this, we cancel both the fundamental signal and its harmonics. Furthermore, an efficient processing scheme for identifying and removing spikes in TDIP data was developed. The noise cancellation and the de-spiking allow the use of earlier and narrower gates, down to a few milliseconds after the current turn-off. In addition, tapered windows are used in the final gating of IP data, allowing the use of wider and overlapping gates for higher noise suppression with minimal distortion of the signal. For measuring at late times, we have developed an algorithm for removal of the self-potential drift. Usually constant or linear drift-removal algorithms are used, but these algorithms often fail in removing the background potentials present when the electrodes used for potential readings are previously used for current injection, also for simple contact resistance measurements. We developed a drift-removal scheme that models the polarization effect and efficiently allows for preserving the shape of the IP responses at late times. Uncertainty estimates are essential in the inversion of IP data. Therefore, in the final step of the data processing, we estimate the data standard deviation based on the data variability within the IP gates and the misfit of the background drift removal Overall, the removal of harmonic noise, spikes, self-potential drift, tapered windowing and the uncertainty estimation allows for doubling the usable range of TDIP data to almost four decades in time (corresponding to four decades in frequency), which will significantly advance the applicability of the IP method.

Carbon Nanostructures in Bone Tissue Engineering

PubMed Central

Perkins, Brian Lee; Naderi, Naghmeh

2016-01-01

Background: Recent advances in developing biocompatible materials for treating bone loss or defects have dramatically changed clinicians’ reconstructive armory. Current clinically available reconstructive options have certain advantages, but also several drawbacks that prevent them from gaining universal acceptance. A wide range of synthetic and natural biomaterials is being used to develop tissue-engineered bone. Many of these materials are currently in the clinical trial stage. Methods: A selective literature review was performed for carbon nanostructure composites in bone tissue engineering. Results: Incorporation of carbon nanostructures significantly improves the mechanical properties of various biomaterials to mimic that of natural bone. Recently, carbon-modified biomaterials for bone tissue engineering have been extensively investigated to potentially revolutionize biomaterials for bone regeneration. Conclusion: This review summarizes the chemical and biophysical properties of carbon nanostructures and discusses their functionality in bone tissue regeneration. PMID:28217212

Comparison of cardiothoracic surgery training in usa and germany

PubMed Central

2010-01-01

Background Training of cardiothoracic surgeons in Europe and the United States has expanded to incorporate new operative techniques and requirements. The purpose of this study was to compare the current structure of training programs in the United States and Germany. Methods We thoroughly reviewed the existing literature with particular focus on the curriculum, salary, board certification and quality of life for cardiothoracic trainees. Results The United States of America and the Federal Republic of Germany each have different cardiothoracic surgery training programs with specific strengths and weaknesses which are compared and presented in this publication. Conclusions The future of cardiothoracic surgery training will become affected by technological, demographic, economic and supply factors. Given current trends in training programs, creating an efficient training system would allow trainees to compete and grow in this constantly changing environment. PMID:21108853

Chiral magnetic effect in the presence of electroweak interactions as a quasiclassical phenomenon

NASA Astrophysics Data System (ADS)

Dvornikov, Maxim; Semikoz, Victor B.

2018-03-01

We elaborate the quasiclassical approach to obtain the modified chiral magnetic effect (CME) in the case when the massless charged fermions interact with electromagnetic fields and the background matter by the electroweak forces. The derivation of the anomalous current along the external magnetic field involves the study of the energy density evolution of chiral particles in parallel electric and magnetic fields. We consider both the particle acceleration by the external electric field and the contribution of the Adler anomaly. The condition of the validity of this method for the derivation of the CME is formulated. We obtain the expression for the electric current along the external magnetic field, which appears to coincide with our previous results based on the purely quantum approach. Our results are compared with the findings of other authors.

Final Report on Jobin Yvon Contained Inductively Coupled Plasma Emission Spectrometer

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

Pennebaker, F.M.

2003-03-17

A new Inductively Coupled Plasma -- Emission Spectrometer (ICP-ES) was recently purchased and installed in Lab B-147/151 at SRTC. The contained JY Model Ultima 170-C ICP-ES has been tested and compared to current ADS ICP-ES instrumentation. The testing has included both performance tests to evaluate instrumental ability, and the measurement of matrix standards commonly analyzed by ICP-ES at Savannah River. In developing operating procedures for this instrument, we have implemented the use of internal standards and off-peak background subtraction. Both of these techniques are recommended by EPA SW-846 ICP-ES methods and are common to current ICP-ES operations. Based on themore » testing and changes, the JY Model Ultima 170-C ICP-ES provides improved performance for elemental analysis of radioactive samples in the Analytical Development Section.« less

Track and vertex reconstruction: From classical to adaptive methods

NASA Astrophysics Data System (ADS)

Strandlie, Are; Frühwirth, Rudolf

2010-04-01

This paper reviews classical and adaptive methods of track and vertex reconstruction in particle physics experiments. Adaptive methods have been developed to meet the experimental challenges at high-energy colliders, in particular, the CERN Large Hadron Collider. They can be characterized by the obliteration of the traditional boundaries between pattern recognition and statistical estimation, by the competition between different hypotheses about what constitutes a track or a vertex, and by a high level of flexibility and robustness achieved with a minimum of assumptions about the data. The theoretical background of some of the adaptive methods is described, and it is shown that there is a close connection between the two main branches of adaptive methods: neural networks and deformable templates, on the one hand, and robust stochastic filters with annealing, on the other hand. As both classical and adaptive methods of track and vertex reconstruction presuppose precise knowledge of the positions of the sensitive detector elements, the paper includes an overview of detector alignment methods and a survey of the alignment strategies employed by past and current experiments.

Dissecting the Gamma-Ray Background in Search of Dark Matter

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

Cholis, Ilias; Hooper, Dan; McDermott, Samuel D.

2014-02-01

Several classes of astrophysical sources contribute to the approximately isotropic gamma-ray background measured by the Fermi Gamma-Ray Space Telescope. In this paper, we use Fermi's catalog of gamma-ray sources (along with corresponding source catalogs at infrared and radio wavelengths) to build and constrain a model for the contributions to the extragalactic gamma-ray background from astrophysical sources, including radio galaxies, star-forming galaxies, and blazars. We then combine our model with Fermi's measurement of the gamma-ray background to derive constraints on the dark matter annihilation cross section, including contributions from both extragalactic and galactic halos and subhalos. The resulting constraints are competitivemore » with the strongest current constraints from the Galactic Center and dwarf spheroidal galaxies. As Fermi continues to measure the gamma-ray emission from a greater number of astrophysical sources, it will become possible to more tightly constrain the astrophysical contributions to the extragalactic gamma-ray background. We project that with 10 years of data, Fermi's measurement of this background combined with the improved constraints on the astrophysical source contributions will yield a sensitivity to dark matter annihilations that exceeds the strongest current constraints by a factor of ~ 5 - 10.« less

Optical Thin Film Thickness Measurement for the Single Atom Microscope

NASA Astrophysics Data System (ADS)

Nelson, Courtney; Frisbie, Dustin; Singh, Jaideep; Spinlab Team

2017-09-01

The Single Atom Microscope Project proposes an efficient, selective, and sensitive method to measure the 1022Ne+24 He ->1225 Mg + n reaction. This rare nuclear reaction is a source of neutrons for heavy element development through the slow neutron capture process. This method embeds Magnesium atoms in a solid neon film. The Magnesium atoms exhibit a shifted fluorescence spectrum allowing for the detection of individual fluorescence photons against the excitation light background. Currently, Ytterbium is used in place of Magnesium-25 because it has been more thoroughly studied than Magnesium and we expect it to have a brighter signal. To identify the signal emitted from the Ytterbium atoms, we need to quantify the amount of signal and background per atom in the neon film. We need to know the film thickness to find the number of atoms in the film to determine the amount of light emitted per atom. In preparation for the neon film measurement, I constructed an experiment to advance the understanding of what is required to optically measure a thin film by using a cover glass slide in place of the thin film. This preliminary experiment has determined a measurement method for finding the thickness of a neon thin film on a sapphire substrate. This work is supported by Michigan State University, U.S. National Science Foundation under Grant Number 1654610, and U.S. NSF REU.

Background feature descriptor for offline handwritten numeral recognition

NASA Astrophysics Data System (ADS)

Ming, Delie; Wang, Hao; Tian, Tian; Jie, Feiran; Lei, Bo

2011-11-01

This paper puts forward an offline handwritten numeral recognition method based on background structural descriptor (sixteen-value numerical background expression). Through encoding the background pixels in the image according to a certain rule, 16 different eigenvalues were generated, which reflected the background condition of every digit, then reflected the structural features of the digits. Through pattern language description of images by these features, automatic segmentation of overlapping digits and numeral recognition can be realized. This method is characterized by great deformation resistant ability, high recognition speed and easy realization. Finally, the experimental results and conclusions are presented. The experimental results of recognizing datasets from various practical application fields reflect that with this method, a good recognition effect can be achieved.

Salvage Procedures for Management of Prosthetic Joint Infection After Hip and Knee Replacements

PubMed Central

Mahmoud, Samer S.S.; Sukeik, Mohamed; Alazzawi, Sulaiman; Shaath, Mohammed; Sabri, Omar

2016-01-01

Background: The increasing load placed by joint replacement surgery on health care systems makes infection, even with the lowest rates, a serious concern that needs to be thoroughly studied and addressed using all possible measures. Methods: A comprehensive review of the current literature on salvage procedures for recurrent PJIs using PubMed, EMBASE and CINAHL has been conducted. Results: Prolonged suppressive antibiotic therapy (PSAT), resection arthroplasty and arthrodesis were the most common procedures performed. Suppressive antibiotic therapy is based on the use of well tolerated long term antibiotics in controlling sensitive organisms. Resection arthroplasty which should be reserved as a last resort provided more predictable outcomes in the hip whereas arthrodesis was associated with better outcomes in the knee. Various methods for arthrodesis including internal and external fixation have been described. Conclusion: Despite good union and infection control rates, all methods were associated with complications occasionally requiring further surgical interventions. PMID:28144373

Comparative study of the antioxidant capacity and polyphenol content of Douro wines by chemical and electrochemical methods.

PubMed

Rebelo, M J; Rego, R; Ferreira, M; Oliveira, M C

2013-11-01

A comparative study of the antioxidant capacity and polyphenols content of Douro wines by chemical (ABTS and Folin-Ciocalteau) and electrochemical methods (cyclic voltammetry and differential pulse voltammetry) was performed. A non-linear correlation between cyclic voltammetric results and ABTS or Folin-Ciocalteau data was obtained if all types of wines (white, muscatel, ruby, tawny and red wines) are grouped together in the same correlation plot. In contrast, a very good linear correlation was observed between the electrochemical antioxidant capacity determined by differential pulse voltammetry and the radical scavenging activity of ABTS. It was also found that the antioxidant capacity of wines evaluated by the electrochemical methods (expressed as gallic acid equivalents) depend on background electrolyte of the gallic acid standards, type of electrochemical signal (current or charge) and electrochemical technique. Copyright © 2013 Elsevier Ltd. All rights reserved.

Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

PubMed Central

Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

2010-01-01

Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

Development and optimization of a diode laser for photodynamic therapy

PubMed Central

Lim, Hyun Soo

2011-01-01

Background and Aims: This study demonstrated the development of a laser system for cancer treatment with photodynamic therapy (PDT) based on a 635 nm laser diode. In order to optimize efficacy in PDT, the ideal laser system should deliver a homogeneous nondivergent light energy with a variable spot size and specific wavelength at a stable output power. Materials and Methods: We developed a digital laser beam controller using the constant current method to protect the laser diode resonator from the current spikes and other fluctuations, and electrical faults. To improve the PDT effects, the laser system should deliver stable laser energy in continuous wave (CW), burst mode and super burst mode, with variable irradiation times depending on the tumor type and condition. Results and Comments: The experimental results showed the diode laser system described herein was eminently suitable for PDT. The laser beam was homogeneous without diverging and the output power increased stably and in a linear manner from 10 mW to 1500 mW according to the increasing input current. Variation between the set and delivered output was less than 7%. Conclusions: The diode laser system developed by the author for use in PDT was compact, user-friendly, and delivered a stable and easily adjustable output power at a specific wavelength and user-set emission modes. PMID:24155529

Current Concepts: Osteochondritis Dissecans of the Capitellum and the Role of Osteochondral Autograft Transplantation.

PubMed

Kirsch, Jacob M; Thomas, Jared; Bedi, Asheesh; Lawton, Jeffrey N

2016-12-01

Background: Osteochondritis dissecans (OCD) of the capitellum is a painful condition, which often affects young throwing athletes. Our current understanding regarding the etiology, risks factors, diagnosis, and efficacy of the available treatment options has expanded over recent years, however remains suboptimal. Recent data on patient-reported outcomes following osteochondral autograft transplantation (OAT) for the treatment of large osteochondral lesions of the capitellum have been promising but limited. This review seeks to critically analyze and summarize the available literature on the etiology, diagnosis, and reported outcomes associated with OCD of the capitellum and the use of OAT for its treatment. Methods: A comprehensive literature search was conducted. Unique and customized search strategies were formulated in PubMed, Embase, Scopus, Web of Science, and CENTRAL. Combinations of keywords and controlled vocabulary terms were utilized in order to cast a broad net. Relevant clinical, biomechanical, anatomic and imaging studies were reviewed along with recent review articles, and case series. Results: Forty-three articles from our initial literature search were found to be relevant for this review. The majority of these articles were either review articles, clinical studies, anatomic or imaging studies or biomechanical studies. Conclusions: Current evidence suggests that OAT may lead to better and more consistent outcomes than previously described methods for treating large OCD lesions of the capitellum.

Adequacy of Current State Setbacks for Directional High-Volume Hydraulic Fracturing in the Marcellus, Barnett, and Niobrara Shale Plays

PubMed Central

Haley, Marsha; McCawley, Michael; Epstein, Anne C.; Arrington, Bob; Bjerke, Elizabeth Ferrell

2016-01-01

Background: There is an increasing awareness of the multiple potential pathways leading to human health risks from hydraulic fracturing. Setback distances are a legislative method to mitigate potential risks. Objectives: We attempted to determine whether legal setback distances between well-pad sites and the public are adequate in three shale plays. Methods: We reviewed geography, current statutes and regulations, evacuations, thermal modeling, air pollution studies, and vapor cloud modeling within the Marcellus, Barnett, and Niobrara Shale Plays. Discussion: The evidence suggests that presently utilized setbacks may leave the public vulnerable to explosions, radiant heat, toxic gas clouds, and air pollution from hydraulic fracturing activities. Conclusions: Our results suggest that setbacks may not be sufficient to reduce potential threats to human health in areas where hydraulic fracturing occurs. It is more likely that a combination of reasonable setbacks with controls for other sources of pollution associated with the process will be required. Citation: Haley M, McCawley M, Epstein AC, Arrington B, Bjerke EF. 2016. Adequacy of current state setbacks for directional high-volume hydraulic fracturing in the Marcellus, Barnett, and Niobrara Shale Plays. Environ Health Perspect 124:1323–1333; http://dx.doi.org/10.1289/ehp.1510547 PMID:26895553

A Novel Method for Detection of Phosphorylation in Single Cells by Surface Enhanced Raman Scattering (SERS) using Composite Organic-Inorganic Nanoparticles (COINs)

PubMed Central

Shachaf, Catherine M.; Elchuri, Sailaja V.; Koh, Ai Leen; Zhu, Jing; Nguyen, Lienchi N.; Mitchell, Dennis J.; Zhang, Jingwu; Swartz, Kenneth B.; Sun, Lei; Chan, Selena; Sinclair, Robert; Nolan, Garry P.

2009-01-01

Background Detection of single cell epitopes has been a mainstay of immunophenotyping for over three decades, primarily using fluorescence techniques for quantitation. Fluorescence has broad overlapping spectra, limiting multiplexing abilities. Methodology/Principal Findings To expand upon current detection systems, we developed a novel method for multi-color immuno-detection in single cells using “Composite Organic-Inorganic Nanoparticles” (COINs) Raman nanoparticles. COINs are Surface-Enhanced Raman Scattering (SERS) nanoparticles, with unique Raman spectra. To measure Raman spectra in single cells, we constructed an automated, compact, low noise and sensitive Raman microscopy device (Integrated Raman BioAnalyzer). Using this technology, we detected proteins expressed on the surface in single cells that distinguish T-cells among human blood cells. Finally, we measured intracellular phosphorylation of Stat1 (Y701) and Stat6 (Y641), with results comparable to flow cytometry. Conclusions/Significance Thus, we have demonstrated the practicality of applying COIN nanoparticles for measuring intracellular phosphorylation, offering new possibilities to expand on the current fluorescent technology used for immunoassays in single cells. PMID:19367337

The Effects of Prolotherapy With Hypertonic Dextrose Versus Prolozone (Intraarticular Ozone) in Patients With Knee Osteoarthritis

PubMed Central

Hashemi, Masoud; Jalili, Parviz; Mennati, Shirin; Koosha, Alireza; Rohanifar, Ramin; Madadi, Firouz; Razavi, Seyed Sajad; Taheri, Farinaz

2015-01-01

Background: Knee osteoarthritis (KOA) is a common disabling disease. Limited studies have demonstrated that prolotherapy with dextrose or with prolozone can be helpful in the treatment of patients with KOA. Objectives: In the current study, we compared the results between these two treatment methods. Patients and Methods: In the current randomized clinical trial, 80 patients with mild to moderate KOA were randomly assigned equally into two groups (ozone group and dextrose group). In each group, injections were repeated three times with 10-day intervals. Before the treatment and 3 months after the injections, the pain intensity was measured by using a visual analogue scale and the Western Ontario and McMaster university arthritis index scores. Finally, the results were compared between the two groups. Results: In the two groups, the pain intensity and WOMAC scores significantly decreased and increased, respectively (P < 0.001). However, there was no significant difference between the two groups. Conclusions: Prolotherapy with dextrose and with prolozone result in the same pain relief or functional improvement in patients with mild to moderate KOA. PMID:26587401

Method for calibration-free scanned-wavelength modulation spectroscopy for gas sensing

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

Hanson, Ronald K.; Jeffries, Jay B.; Sun, Kai

A method of calibration-free scanned-wavelength modulation spectroscopy (WMS) absorption sensing is provided by obtaining absorption lineshape measurements of a gas sample on a sensor using 1f-normalized WMS-2f where an injection current to an injection current-tunable diode laser (TDL) is modulated at a frequency f, where a wavelength modulation and an intensity modulation of the TDL are simultaneously generated, extracting using a numerical lock-in program and a low-pass filter appropriate band-width WMS-nf (n=1, 2, . . . ) signals, where the WMS-nf signals are harmonics of the f, determining a physical property of the gas sample according to ratios of themore » WMS-nf signals, determining the zero-absorption background using scanned-wavelength WMS, and determining non-absorption losses using at least two of the harmonics, where a need for a non-absorption baseline measurement is removed from measurements in environments where collision broadening has blended transition linewidths, where calibration free WMS measurements without knowledge of the transition linewidth is enabled.« less

Restructuring brain drain: strengthening governance and financing for health worker migration

PubMed Central

Mackey, Tim K.; Liang, Bryan A.

2013-01-01

Background Health worker migration from resource-poor countries to developed countries, also known as ‘‘brain drain’’, represents a serious global health crisis and a significant barrier to achieving global health equity. Resource-poor countries are unable to recruit and retain health workers for domestic health systems, resulting in inadequate health infrastructure and millions of dollars in healthcare investment losses. Methods Using acceptable methods of policy analysis, we first assess current strategies aimed at alleviating brain drain and then propose our own global health policy based solution to address current policy limitations. Results Although governments and private organizations have tried to address this policy challenge, brain drain continues to destabilise public health systems and their populations globally. Most importantly, lack of adequate financing and binding governance solutions continue to fail to prevent health worker brain drain. Conclusions In response to these challenges, the establishment of a Global Health Resource Fund in conjunction with an international framework for health worker migration could create global governance for stable funding mechanisms encourage equitable migration pathways, and provide data collection that is desperately needed. PMID:23336617

Social representation of hearing aids: cross-cultural study in India, Iran, Portugal, and the United Kingdom

PubMed Central

Manchaiah, Vinaya; Danermark, Berth; Vinay; Ahmadi, Tayebeh; Tomé, David; Krishna, Rajalakshmi; Germundsson, Per

2015-01-01

Background The current study was aimed at understanding the social representation of hearing aids in India, Iran, Portugal, and the United Kingdom. We also compared these results to explore the cross-cultural differences and similarities among these countries. Methods The study involved a cross-sectional design, and the data were collected from four different countries using the snowball sampling method. Data were analyzed using a content analysis to identify the most-similar categories of responses reported, a co-occurrences analysis to see which of these categories are reported commonly, and a chi-square analysis to study if there was any association between positive, neutral, and negative connotations among participants in different countries. Results The current study revealed four different social representations of hearing aids from India, Iran, Portugal, and the United Kingdom, and also a global index. Conclusion The study results provide very useful insights into how hearing aids are represented in the society. These findings may have important implications for public education and also for manufacturers from the viewpoint of designing and marketing hearing aids in different countries. PMID:26504376

The Atacama Cosmology Telescope (ACT): Beam Profiles and First SZ Cluster Maps

NASA Technical Reports Server (NTRS)

Hincks, A. D.; Acquaviva, V.; Ade, P. A.; Aguirre, P.; Amiri, M.; Appel, J. W.; Barrientos, L. F.; Battistelli, E. S.; Bond, J. R.; Brown, B.;

Two-phase Computerized Planning of Cryosurgery Using Bubble-packing and Force-field Analogy

PubMed Central

Tanaka, Daigo; Shimada, Kenji; Rabin, Yoed

2007-01-01

Background: Cryosurgery is the destruction of undesired tissues by freezing, as in prostate cryosurgery, for example. Minimally-invasive cryosurgery is currently performed by means of an array of cryoprobes, each in the shape of a long hypodermic needle. The optimal arrangement of the cryoprobes, which is known to have a dramatic effect on the quality of the cryoprocedure, remains an art held by the cryosurgeon, based on the cryosurgeon's experience and “rules of thumb.” An automated computerized technique for cryosurgery planning is the subject matter of the current report, in an effort to improve the quality of cryosurgery. Method of Approach: A two-phase optimization method is proposed for this purpose, based on two previous and independent developments by this research team. Phase I is based on a bubble-packing method, previously used as an efficient method for finite elements meshing. Phase II is based on a force-field analogy method, which has proven to be robust at the expense of a typically long runtime. Results: As a proof-of-concept, results are demonstrated on a 2D case of a prostate cross-section. The major contribution of this study is to affirm that in many instances cryosurgery planning can be performed without extremely expensive simulations of bioheat transfer, achieved in Phase I. Conclusions: This new method of planning has proven to reduce planning runtime from hours to minutes, making automated planning practical in a clinical time frame. PMID:16532617

Let the pyramid guide your food choices: capturing the total diet concept.

PubMed

Dixon, L B; Cronin, F J; Krebs-Smith, S M

2001-02-01

This paper discusses how the guideline "Eat a variety of foods" became "Let the Pyramid guide your food choices," presents background information on the food guidance system upon which the Food Guide Pyramid is based and reviews methods that have been used to assess aspects of the total diet, i.e., the variety, moderation and proportionality, promoted by this guidance. The methods include measures of dietary variety, patterns based on Pyramid food group intakes and scoring methods comprised of multiple dietary components. Highlights of results from these methods include the following. Although approximately one third of the U.S. population eat at least some food from all Pyramid food groups, only approximately 1-3% eat the recommended number of servings from all food groups on a given day. Fruits are the most commonly omitted food group. Vegetables and meat are the groups most commonly met by adults, and dairy the most commonly met by youth. Intakes of specific types of vegetables (i.e., dark green, deep yellow) and of grains (i.e., whole grains) are well below that recommended; intakes of total fat and added sugars exceed current recommendations. Scoring methods show those diets of the majority of the population require improvement, and that diets improve with increases in education and income. This paper also discusses the limitations and strengths of these approaches, and concludes with suggestions to improve current food guidance and methods to assess the total diet.

Limitations of the background field method applied to Rayleigh-Bénard convection

NASA Astrophysics Data System (ADS)

Nobili, Camilla; Otto, Felix

2017-09-01

We consider Rayleigh-Bénard convection as modeled by the Boussinesq equations, in the case of infinite Prandtl numbers and with no-slip boundary condition. There is a broad interest in bounds of the upwards heat flux, as given by the Nusselt number Nu, in terms of the forcing via the imposed temperature difference, as given by the Rayleigh number in the turbulent regime Ra ≫ 1 . In several studies, the background field method applied to the temperature field has been used to provide upper bounds on Nu in terms of Ra. In these applications, the background field method comes in the form of a variational problem where one optimizes a stratified temperature profile subject to a certain stability condition; the method is believed to capture the marginal stability of the boundary layer. The best available upper bound via this method is Nu ≲Ra/1 3 ( ln R a )/1 15 ; it proceeds via the construction of a stable temperature background profile that increases logarithmically in the bulk. In this paper, we show that the background temperature field method cannot provide a tighter upper bound in terms of the power of the logarithm. However, by another method, one does obtain the tighter upper bound Nu ≲ Ra /1 3 ( ln ln Ra ) /1 3 so that the result of this paper implies that the background temperature field method is unphysical in the sense that it cannot provide the optimal bound.

Research on "STI +" Model in College Entrepreneurship Education

ERIC Educational Resources Information Center

Liu, Maike; Xu, Shuo; Gu, Jibao

2017-01-01

The current state attaches great importance to college entrepreneurship education, but entrepreneurship education should combine with college students' professional learning. Different professional learning backgrounds have commonalities in entrepreneurship education; there may be differences, too. Various professional knowledge background and…

Critical Analysis of Different Methods to Retrieve Atmosphere Humidity Profiles from GNSS Radio Occultation Observations

NASA Astrophysics Data System (ADS)

Vespe, Francesco; Benedetto, Catia

2013-04-01

The huge amount of GPS Radio Occultation (RO) observations currently available thanks to space mission like COSMIC, CHAMP, GRACE, TERRASAR-X etc., have greatly encouraged the research of new algorithms suitable to extract humidity, temperature and pressure profiles of the atmosphere in a more and more precise way. For what concern the humidity profiles in these last years two different approaches have been widely proved and applied: the "Simple" and the 1DVAR methods. The Simple methods essentially determine dry refractivity profiles from temperature analysis profiles and hydrostatic equation. Then the dry refractivity is subtracted from RO refractivity to achieve the wet component. Finally from the wet refractivity is achieved humidity. The 1DVAR approach combines RO observations with profiles given by the background models with both the terms weighted with the inverse of covariance matrix. The advantage of "Simple" methods is that they are not affected by bias due to the background models. We have proposed in the past the BPV approach to retrieve humidity. Our approach can be classified among the "Simple" methods. The BPV approach works with dry atmospheric CIRA-Q models which depend on latitude, DoY and height. The dry CIRA-Q refractivity profile is selected estimating the involved parameters in a non linear least square fashion achieved by fitting RO observed bending angles through the stratosphere. The BPV as well as all the other "Simple" methods, has as drawback the unphysical occurrence of negative "humidity". Thus we propose to apply a modulated weighting of the fit residuals just to minimize the effects of this inconvenient. After a proper tuning of the approach, we plan to present the results of the validation.

Comparing and Contrasting Consensus versus Empirical Domains

PubMed Central

Jason, Leonard A.; Kot, Bobby; Sunnquist, Madison; Brown, Abigail; Reed, Jordan; Furst, Jacob; Newton, Julia L.; Strand, Elin Bolle; Vernon, Suzanne D.

2015-01-01

Background Since the publication of the CFS case definition [1], there have been a number of other criteria proposed including the Canadian Consensus Criteria [2] and the Myalgic Encephalomyelitis: International Consensus Criteria. [3] Purpose The current study compared these domains that were developed through consensus methods to one obtained through more empirical approaches using factor analysis. Methods Using data mining, we compared and contrasted fundamental features of consensus-based criteria versus empirical latent factors. In general, these approaches found the domain of Fatigue/Post-exertional malaise as best differentiating patients from controls. Results Findings indicated that the Fukuda et al. criteria had the worst sensitivity and specificity. Conclusions These outcomes might help both theorists and researchers better determine which fundamental domains to be used for the case definition. PMID:26977374

Paracoccidioidomycosis: Current Perspectives from Brazil

PubMed Central

Mendes, Rinaldo Poncio; Cavalcante, Ricardo de Souza; Marques, Sílvio Alencar; Marques, Mariângela Esther Alencar; Venturini, James; Sylvestre, Tatiane Fernanda; Paniago, Anamaria Mello Miranda; Pereira, Ana Carla; da Silva, Julhiany de Fátima; Fabro, Alexandre Todorovic; Bosco, Sandra de Moraes Gimenes; Bagagli, Eduardo; Hahn, Rosane Christine; Levorato, Adriele Dandara

2017-01-01

Background: This review article summarizes and updates the knowledge on paracoccidioidomycosis. P lutzii and the cryptic species of P. brasiliensis and their geographical distribution in Latin America, explaining the difficulties observed in the serological diagnosis. Objectives: Emphasis has been placed on some genetic factors as predisposing condition for paracoccidioidomycosis. Veterinary aspects were focused, showing the wide distribution of infection among animals. The cell-mediated immunity was better characterized, incorporating the recent findings. Methods: Serological methods for diagnosis were also compared for their parameters of accuracy, including the analysis of relapse. Results: Clinical forms have been better classified in order to include the pictures less frequently observesiod. Conclusion: Itraconazole and the trimethoprim-sulfamethoxazole combination was compared regarding efficacy, effectiveness and safety, demonstrating that azole should be the first choice in the treatment of paracoccidioidomycosis. PMID:29204222

Psychosocial Determinants of Tobacco Use among School Going Adolescents in Delhi, India

PubMed Central

Kumar, Varun; Talwar, Richa; Roy, Neelam; Raut, Deepak; Singh, Saudan

2014-01-01

Background. Tobacco use is one of the major preventable causes of premature death and disease in the world. Many psychosocial factors were found to influence tobacco use. Therefore the present study was designed to determine the role of psychosocial factors associated with tobacco use among school going adolescents in Delhi, India. Methods. Cross-sectional study was conducted from February 2013 to September 2013 in four government schools in South district of Delhi, India. The questionnaire contains questions adapted from GYTS (Global Youth Tobacco Survey) to find the prevalence and pattern of tobacco use among adolescents. Data were analyzed using SPSS version 21. Results. The prevalence of ever and current tobacco use was found in 16.4% and 13.1%. Current smoking and current tobacco chewing were found in 10.2% and 9.4% students, respectively. The risk of current tobacco use was found to be higher among males (P value = 0.000) and in those who got higher pocket money (P value = 0.000). Psychosocial factors like lower general self-efficacy and maladjustments with peers, teachers, and schools were also found to be significant predictors of current tobacco use. Conclusion. The study has revealed higher prevalence of ever and current tobacco use among adolescent students in Delhi, India. PMID:25431738

The Risk Factors of Performance-Based Early Frailty in Midlife and Older Age.

PubMed

Peterson, Matthew J

2018-01-01

Background: Identifying impairments prior to onset of physical frailty may inform targeted interventions. An objective, clinically feasible early frailty measure, termed performance-based early frailty (PBEF) was developed, and antecedent and current risk factors were examined. Method: Data were from N = 104 participants of the Fels Longitudinal Study. PBEF was derived from age-specific cut points for time to complete five chair stands and walk four meters. "Pre-PBEF" and "PBEF" were defined as impairment in one or both measures, respectively. Candidate PBEF risk factors included body composition, health and quality of life, grip strength, and biomarker measures. Results: Pre-PBEF was identified in 26% and 30% of midlife and older adults, and PBEF was identified in 11% and 14% of midlife and older adults, respectively. When predicting midlife PBEF, only current physical activity was significant (odds ratio [OR] = 0.18). In older adults, PBEF status was predicted by previous heavier drinking (OR = 3.09), previous better grip strength (OR = 0.92), current poorer sleep habits (OR = 1.19), and current higher C-reactive protein concentrations (OR = 1.20). Conclusion: Differing age group patterns of predictors emerged, suggesting that PBEF in midlife is likely a state influenced by current health status, whereas older age PBEF is influenced by both current and antecedent factors.

A novel method to remove GPR background noise based on the similarity of non-neighboring regions

NASA Astrophysics Data System (ADS)

Montiel-Zafra, V.; Canadas-Quesada, F. J.; Vera-Candeas, P.; Ruiz-Reyes, N.; Rey, J.; Martinez, J.

2017-09-01

Ground penetrating radar (GPR) is a non-destructive technique that has been widely used in many areas of research, such as landmine detection or subsurface anomalies, where it is required to locate targets embedded within a background medium. One of the major challenges in the research of GPR data remains the improvement of the image quality of stone materials by means of detection of true anisotropies since most of the errors are caused by an incorrect interpretation by the users. However, it is complicated due to the interference of the horizontal background noise, e.g., the air-ground interface, that reduces the high-resolution quality of radargrams. Thus, weak or deep anisotropies are often masked by this type of noise. In order to remove the background noise obtained by GPR, this work proposes a novel background removal method assuming that the horizontal noise shows repetitive two-dimensional regions along the movement of the GPR antenna. Specifically, the proposed method, based on the non-local similarity of regions over the distance, computes similarities between different regions of the same depth in order to identify most repetitive regions using a criterion to avoid closer regions. Evaluations are performed using a set of synthetic and real GPR data. Experimental results show that the proposed method obtains promising results compared to the classic background removal techniques and the most recently published background removal methods.

Structured background grids for generation of unstructured grids by advancing front method

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar

1991-01-01

A new method of background grid construction is introduced for generation of unstructured tetrahedral grids using the advancing-front technique. Unlike the conventional triangular/tetrahedral background grids which are difficult to construct and usually inadequate in performance, the new method exploits the simplicity of uniform Cartesian meshes and provides grids of better quality. The approach is analogous to solving a steady-state heat conduction problem with discrete heat sources. The spacing parameters of grid points are distributed over the nodes of a Cartesian background grid by interpolating from a few prescribed sources and solving a Poisson equation. To increase the control over the grid point distribution, a directional clustering approach is used. The new method is convenient to use and provides better grid quality and flexibility. Sample results are presented to demonstrate the power of the method.

Python package for model STructure ANalysis (pySTAN)

NASA Astrophysics Data System (ADS)

Van Hoey, Stijn; van der Kwast, Johannes; Nopens, Ingmar; Seuntjens, Piet

2013-04-01

The selection and identification of a suitable hydrological model structure is more than fitting parameters of a model structure to reproduce a measured hydrograph. The procedure is highly dependent on various criteria, i.e. the modelling objective, the characteristics and the scale of the system under investigation as well as the available data. Rigorous analysis of the candidate model structures is needed to support and objectify the selection of the most appropriate structure for a specific case (or eventually justify the use of a proposed ensemble of structures). This holds both in the situation of choosing between a limited set of different structures as well as in the framework of flexible model structures with interchangeable components. Many different methods to evaluate and analyse model structures exist. This leads to a sprawl of available methods, all characterized by different assumptions, changing conditions of application and various code implementations. Methods typically focus on optimization, sensitivity analysis or uncertainty analysis, with backgrounds from optimization, machine-learning or statistics amongst others. These methods also need an evaluation metric (objective function) to compare the model outcome with some observed data. However, for current methods described in literature, implementations are not always transparent and reproducible (if available at all). No standard procedures exist to share code and the popularity (and amount of applications) of the methods is sometimes more dependent on the availability than the merits of the method. Moreover, new implementations of existing methods are difficult to verify and the different theoretical backgrounds make it difficult for environmental scientists to decide about the usefulness of a specific method. A common and open framework with a large set of methods can support users in deciding about the most appropriate method. Hence, it enables to simultaneously apply and compare different methods on a fair basis. We developed and present pySTAN (python framework for STructure Analysis), a python package containing a set of functions for model structure evaluation to provide the analysis of (hydrological) model structures. A selected set of algorithms for optimization, uncertainty and sensitivity analysis is currently available, together with a set of evaluation (objective) functions and input distributions to sample from. The methods are implemented model-independent and the python language provides the wrapper functions to apply administer external model codes. Different objective functions can be considered simultaneously with both statistical metrics and more hydrology specific metrics. By using so-called reStructuredText (sphinx documentation generator) and Python documentation strings (docstrings), the generation of manual pages is semi-automated and a specific environment is available to enhance both the readability and transparency of the code. It thereby enables a larger group of users to apply and compare these methods and to extend the functionalities.

Use of traditional contraceptive methods in India & its socio-demographic determinants.

PubMed

Ram, Faujdar; Shekhar, Chander; Chowdhury, Biswabandita

2014-11-01

The high use of traditional contraceptive methods may have health repercussions on both partners. High failure rate, lack of protection from sexually transmitted diseases are some of the examples of these repercussions. The aim of this study was to understand the level, trends, pattern, volume and socio-demographic determinants of using traditional contraceptive methods in the Indian context. Percentages, per cent distribution, cross-tabulation and multinomial logistic regression analyses were carried out. The data from the three rounds of National Family Health survey (NFHS) were used. The unit level District Level Household Survey (2007-2008) were mainly used to carry out the analysis in this paper. Marriage rates for States and Union Territories (UTs) were projected for the period of 2001-2011 to estimate the volume of traditional contraceptive users. These rates are required to get the number of eligible couples as on 2011 in the respective State/UT. The latest round of the District Level Household Survey (2007-2008) revealed that 6.7 per cent currently married women were using traditional contraceptive methods in India. More than half of the currently married women (56%) have ever used these methods. In terms of socio-demographic determinants, the odds ratios of using these methods were significantly higher for women aged 35 years and above, rural, Hindu, other than Scheduled Castes/Tribes (SCs/STs), secondary and above educated, non-poor, having two plus living children, and at least one surviving son in most of the states as well as at the national level. The northeastern region showed higher odds ratios (5 times) of women using traditional contraceptive methods than the southern region. A large number of currently married women have ever used the traditional contraceptive methods in India. On the basis of the findings from this study, the total size of those women who were using traditional methods and those who were having unmet need, and are required to use modern spacing methods of family planning in achieving the reproductive goals, is around 53 million. Women from a set of specific socio-demographic backgrounds are more likely to use these methods. A regional pattern has also emerged in use of tradition contraceptive methods in India.

Inhibition of recombinase polymerase amplification by background DNA: a lateral flow-based method for enriching target DNA.

PubMed

Rohrman, Brittany; Richards-Kortum, Rebecca

2015-02-03

Recombinase polymerase amplification (RPA) may be used to detect a variety of pathogens, often after minimal sample preparation. However, previous work has shown that whole blood inhibits RPA. In this paper, we show that the concentrations of background DNA found in whole blood prevent the amplification of target DNA by RPA. First, using an HIV-1 RPA assay with known concentrations of nonspecific background DNA, we show that RPA tolerates more background DNA when higher HIV-1 target concentrations are present. Then, using three additional assays, we demonstrate that the maximum amount of background DNA that may be tolerated in RPA reactions depends on the DNA sequences used in the assay. We also show that changing the RPA reaction conditions, such as incubation time and primer concentration, has little effect on the ability of RPA to function when high concentrations of background DNA are present. Finally, we develop and characterize a lateral flow-based method for enriching the target DNA concentration relative to the background DNA concentration. This sample processing method enables RPA of 10(4) copies of HIV-1 DNA in a background of 0-14 μg of background DNA. Without lateral flow sample enrichment, the maximum amount of background DNA tolerated is 2 μg when 10(6) copies of HIV-1 DNA are present. This method requires no heating or other external equipment, may be integrated with upstream DNA extraction and purification processes, is compatible with the components of lysed blood, and has the potential to detect HIV-1 DNA in infant whole blood with high proviral loads.

Transgender in China

ERIC Educational Resources Information Center

Jun, Pi

2010-01-01

This autobiographical essay of a Chinese transgender who has grown up in a special social background involves the Chinese family, religion, and some social background to demonstrate the current situation of lesbian, gay, bisexual, and transgender groups, especially the condition of female-to-male transgender.

Background Noise Reduction Using Adaptive Noise Cancellation Determined by the Cross-Correlation

NASA Technical Reports Server (NTRS)

Spalt, Taylor B.; Brooks, Thomas F.; Fuller, Christopher R.

2012-01-01

Background noise due to flow in wind tunnels contaminates desired data by decreasing the Signal-to-Noise Ratio. The use of Adaptive Noise Cancellation to remove background noise at measurement microphones is compromised when the reference sensor measures both background and desired noise. The technique proposed modifies the classical processing configuration based on the cross-correlation between the reference and primary microphone. Background noise attenuation is achieved using a cross-correlation sample width that encompasses only the background noise and a matched delay for the adaptive processing. A present limitation of the method is that a minimum time delay between the background noise and desired signal must exist in order for the correlated parts of the desired signal to be separated from the background noise in the crosscorrelation. A simulation yields primary signal recovery which can be predicted from the coherence of the background noise between the channels. Results are compared with two existing methods.

Readout circuit with novel background suppression for long wavelength infrared focal plane arrays

NASA Astrophysics Data System (ADS)

Xie, L.; Xia, X. J.; Zhou, Y. F.; Wen, Y.; Sun, W. F.; Shi, L. X.

2011-02-01

In this article, a novel pixel readout circuit using a switched-capacitor integrator mode background suppression technique is presented for long wavelength infrared focal plane arrays. This circuit can improve dynamic range and signal-to-noise ratio by suppressing the large background current during integration. Compared with other background suppression techniques, the new background suppression technique is less sensitive to the process mismatch and has no additional shot noise. The proposed circuit is theoretically analysed and simulated while taking into account the non-ideal characteristics. The result shows that the background suppression non-uniformity is ultra-low even for a large process mismatch. The background suppression non-uniformity of the proposed circuit can also remain very small with technology scaling.

The MAJORANA DEMONSTRATOR for 0νββ: Current status and future plans

DOE PAGES

Green, M. P.; Abgrall, N.; Aguayo, E.; ...

2015-01-01

The Majorana Demonstrator will search for neutrinoless-double-beta decay (0νββ) in 76Ge, while establishing the feasibility of a future tonne-scale germanium-based 0νββ experiment, and performing searches for new physics beyond the Standard Model. The experiment, currently under construction at the Sanford Underground Research Facility in Lead, SD, will consist of a pair of modular high-purity germanium detector arrays housed inside of a compact copper, lead, and polyethylene shield. Through a combination of strict materials qualifications and assay, low-background design, and powerful background rejection techniques, the Demonstrator aims to achieve a background rate in the 0νββ region of interest (ROI) of nomore » more than 3 counts in the 0νββ-decay ROI per tonne of target isotope per year (cnts/(ROI-t-y)). The current status of the Demonstrator is discussed, as are plans for its completion.« less

Unfolding Neutron Spectrum with Markov Chain Monte Carlo at MIT Research Reactor with He-3 Neutral Current Detectors

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

Leder, A.; Anderson, A. J.; Billard, J.

2018-02-02

The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic Neutrino-Nucleus Scattering (CEνNS) using dark-matter-style detectors with sub-keV thresholds placed near a neutrino source, such as the MIT (research) Reactor (MITR), which operates at 5.5 MW generating approximately 2.2 × 1018 ν/second in its core. Currently, Ricochet is characterizing the backgrounds at MITR, the main component of which comes in the form of neutrons emitted from the core simultaneous with the neutrino signal. To characterize this background, we wrapped Bonner cylinders around a 32He thermal neutron detector, whose data was then unfolded via a Markov Chain Monte Carlo (MCMC) to produce a neutron energymore » spectrum across several orders of magnitude. We discuss the resulting spectrum and its implications for deploying Ricochet at the MITR site as well as the feasibility of reducing this background level via the addition of polyethylene shielding around the detector setup.« less