Development of a pulse shape discrimination circuit

International Nuclear Information System (INIS)

Ye Bangjiao; Fan Wei; Fan Yangmei; Yu Xiaoqi; Mei Wen; Wang Zhongmin; Han Rongdian; Xiao Zhenxi

1994-01-01

A pulse shape discrimination circuit was designed and used in an experiment measuring double-differential cross sections of (n, charged particle) reaction; to identify p, α and γ. The performance of the circuit was tested. With this circuit, excellent identification of p, α and γ was obtained. ((orig.))

Particle identification via pulse-shape discrimination with a charge-integrating ADC

International Nuclear Information System (INIS)

Heltsley, J.H.; Brandon, L.; Galonsky, A.; Heilbronn, L.; Remington, B.A.; Langer, S.; Van der Molen, A.; Yurkon, J.; Michigan State Univ., East Lansing; Kasagi, J.

1988-01-01

A charge-integrating ADC has been used to sample the intensity in two different time regions of a pulse and thus to sense the shape of the pulse. This idea has been applied to produce neutron/γ-ray discrimination from pulses in a liquid scintillation detector. Optimization of available parameters yields good pulse-shape discrimination for pulses greater than those produced by 100 keV electrons. The method uses only general purpose electronics. (orig.)

Using otolith shape for intraspecific discrimination: the case of gurnards (Scorpaeniformes, Triglidae

Directory of Open Access Journals (Sweden)

Stefano Montanini

2015-11-01

Full Text Available The sagittal otoliths are sound transducers and play an important role in fish hearing. Triglidae (Teleostei, Scorpaeniformes are known for sound producing ability in agonistic contexts related to territorial defence, reproduction and competitive feeding (Amorim et al., 2004. Chelidonichthys cuculus and C. lucerna show a significant body size-depth relationship and specie-specific feeding strategies with growth. Both juveniles and adults of C. cuculus prey necto-benthic invertebrates while C. lucerna specimens change diet from crustaceans to teleost during growth (Stagioni et al., 2012; Vallisneri et al., 2014; Montanini et al., 2015. The goal of this study was to analyze intraspecific shape variations in sagitta of model species of gurnards. 217 specimens were collected during bottom trawl surveys in Adriatic sea (northeastern Mediterranean. Each left sagitta was removed, cleaned in ultrasounds bath and kept dry. The otolith digital images were processed to calculate five shape indices (aspect ratio, roundness, rectangularity, ellipticity and circularity. Indices were normalised to avoid allometric effects according to Lleonart et al. (2000, than processed by linear discriminant analysis (LDA. The SHAPE program was used to extract the outline and to assess the variability of shapes (EFA method and estimated it through the study of principal component analysis (PCA. Considering the first two discriminant functions, LDA plot showed a clearly separation between juvenile and adults for both species. About EFA, the first 4 principal component discriminated over 80% of variance and significant differences were found at critical size between juveniles and adults for all the components analysed. The allometric trends corresponded to a relative elongation of the sulcus acusticus and an increase of excisura ostii. The combined use of the two external outlines methods should be highly informative for intraspecific discrimination and might be related to

Pulse-shape discrimination in IAEA tritium proportional counters

International Nuclear Information System (INIS)

Florkowski, T.

1981-01-01

Two systems of pulse-shape discrimination (PSD) for the reduction of background in low-level proportional counters were tested. A tentative conclusion is drawn that both PSD systems, although they decrease slightly the meson background, do not bring improvement in the analytical accuracy

Pulse-shape discrimination in radioanalytical methods. Part I. Delayed fission neutron counting

International Nuclear Information System (INIS)

Posta, S.; Vacik, J.; Hnatowicz, V.; Cervena, J.

1999-01-01

In this study the principle of pulse shape discrimination (PSD) has been employed in delayed fission neutron counting (DNC) method. Effective elimination of unwanted gamma background signals in measured radiation spectra has been proved. (author)

Gamma–neutron imaging system utilizing pulse shape discrimination with CLYC

International Nuclear Information System (INIS)

Whitney, Chad M.; Soundara-Pandian, Lakshmi; Johnson, Erik B.; Vogel, Sam; Vinci, Bob; Squillante, Michael; Glodo, Jarek; Christian, James F.

2015-01-01

Recently, RMD has investigated the use of CLYC (Cs 2 LiYCl 6 :Ce), a new and emerging scintillation material, in a gamma–neutron coded aperture imaging system based on RMD's commercial RadCam TM instrument. CLYC offers efficient thermal neutron detection, fast neutron detection capabilities, excellent pulse shape discrimination (PSD), and gamma-ray energy resolution as good as 4% at 662 keV. PSD improves the isolation of higher energy gammas from thermal neutron interactions (>3 MeV electron equivalent peak), compared to conventional pulse height techniques. The scintillation emission time in CLYC provides the basis for PSD; where neutron interactions result in a slower emission rise and decay components while gamma interactions result in a faster emission components. By creating a population plot based on the ratio of the decay tail compared to the total integral amplitude (PSD ratio), discrimination of gammas, thermal neutrons, and fast neutrons is possible. Previously, we characterized the CLYC-based RadCam system for imaging gammas and neutrons using a layered W-Cd coded aperture mask and employing only pulse height discrimination. In this paper, we present the latest results which investigate gamma-neutron imaging capabilities using PSD. An FPGA system is used to acquire the CLYC–PSPMT last dynode signals, determine a PSD ratio for each event, and compare it to a calibrated PSD cutoff. Each event is assigned either a gamma (low) or neutron (high) flag signal which is then correlated with the imaging information for each event. - Highlights: • The latest results are presented for our CLYC RadCam-2 system which investigate gamma–neutron imaging using pulse shape discrimination. • CLYC RadCam-2 system successfully discriminates gammas, thermal neutrons, and fast neutrons by employing a fully integrated, FPGA-based PSD system. • Imaging of our 252 Cf source was possible using both pulse height and pulse shape discrimination with CLYC. • Imaging

Digital pulse shape discrimination

International Nuclear Information System (INIS)

Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

2007-01-01

Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

Near threshold pulse shape discrimination techniques in scintillating CsI(Tl) crystals

International Nuclear Information System (INIS)

Wu, S.C.; Yue, Q.; Lai, W.P.; Li, H.B.; Li, J.; Lin, S.T.; Liu, Y.; Singh, V.; Wang, M.Z.; Wong, H.T.; Xin, B.; Zhou, Z.Y.

2004-01-01

There are recent interests with CsI(Tl) scintillating crystals for Dark Matter experiments. The key merit is the capability to differentiate nuclear recoil (nr) signatures from the background β/γ-events due to ambient radioactivity on the basis of their different pulse shapes. One of the major experimental challenges is to perform such pulse shape analysis in the statistics-limited domain where the light output is close to the detection threshold. Using data derived from measurements with low-energy γ's and nuclear recoils due to neutron elastic scatterings, it was verified that the pulse shapes between β/γ-events are different. Several methods of pulse shape discrimination (PSD) are studied, and their relative merits are compared. Full digitization of the pulse shapes is crucial to achieve good discrimination. Advanced software techniques with mean time, neural network and likelihood ratios give rise to satisfactory performance, and are superior to the conventional Double Charge method commonly applied at higher energies. PSD becomes effective starting at a light yield of about 20 photo-electrons. This corresponds to a detection threshold of about 5 keV electron-equivalence energy, or 40-50 keV recoil kinetic energy, in realistic experiments

Pulse shape discrimination in non-aromatic plastics

Energy Technology Data Exchange (ETDEWEB)

Paul Martinez, H.; Pawelczak, Iwona; Glenn, Andrew M.; Leslie Carman, M.; Zaitseva, Natalia; Payne, Stephen

2015-01-21

Recently it has been demonstrated that plastic scintillators have the ability to distinguish neutrons from gamma rays by way of pulse shape discrimination (PSD). This discovery has lead to new materials and new capabilities. Here we report our work with the effects of aromatic, non-aromatic, and mixed aromatic/non-aromatic matrices have on the performance of PSD plastic scintillators.

Textural Maturity Analysis and Sedimentary Environment Discrimination Based on Grain Shape Data

Science.gov (United States)

Tunwal, M.; Mulchrone, K. F.; Meere, P. A.

2017-12-01

Morphological analysis of clastic sedimentary grains is an important source of information regarding the processes involved in their formation, transportation and deposition. However, a standardised approach for quantitative grain shape analysis is generally lacking. In this contribution we report on a study where fully automated image analysis techniques were applied to loose sediment samples collected from glacial, aeolian, beach and fluvial environments. A range of shape parameters are evaluated for their usefulness in textural characterisation of populations of grains. The utility of grain shape data in ranking textural maturity of samples within a given sedimentary environment is evaluated. Furthermore, discrimination of sedimentary environment on the basis of grain shape information is explored. The data gathered demonstrates a clear progression in textural maturity in terms of roundness, angularity, irregularity, fractal dimension, convexity, solidity and rectangularity. Textural maturity can be readily categorised using automated grain shape parameter analysis. However, absolute discrimination between different depositional environments on the basis of shape parameters alone is less certain. For example, the aeolian environment is quite distinct whereas fluvial, glacial and beach samples are inherently variable and tend to overlap each other in terms of textural maturity. This is most likely due to a collection of similar processes and sources operating within these environments. This study strongly demonstrates the merit of quantitative population-based shape parameter analysis of texture and indicates that it can play a key role in characterising both loose and consolidated sediments. This project is funded by the Irish Petroleum Infrastructure Programme (www.pip.ie)

High‐resolution stock discrimination of Atlantic herring (Clupea harengus) based on otolith shape, microstructure, and genetic markers

DEFF Research Database (Denmark)

Mosegaard, Henrik; Worsøe Clausen, Lotte; Bekkevold, Dorte

2012-01-01

between populations, which suggest genetic control as well. Thus otolith shape serves as a population marker, suitable for individual assignment. Here we use otolith morphological characteristics (otolith shape and larval otolith microstructure) combined with genetic markers to discriminate between...... otolith shape characteristics as separation parameters. Otolith shape was found to clearly discriminate between individuals at all ages from different spawning populations. The identified distances between populations based on otolith shape matched previously obtained genetic distances and were, when......One of the most rapidly developing applications of otolith research is shape analysis, often used for population discrimination as well as for species identification. Otolith shape is influenced by the environment through physiology, but also shows consistent and temporally stable differences...

Digital pulse shape discrimination of detector data using fuzzy clustering

International Nuclear Information System (INIS)

Kumar, Abhinav; Chatterjee, A.; Ramachandran, K.; Shrivastava, A.; Mahata, K.

2011-01-01

In accelerator based experiments, data acquisition is done by CAMAC, VME and other systems. The current trend is to digitize the pulse shapes and not just the peak heights of all the input channels, by means of Flash ADCs. In view of the large number of channels involved, this leads to unprecedented data volumes. Therefore, attempts to perform a first level of analysis in real time using algorithms implemented in FPGA have become important. In the present work, digital pulse shape discrimination using fuzzy clustering has been investigated. The attempt has been to devise general purpose PSD Techniques, loosely coupled with the characteristics of detector or particle type, for particle identification. The method is applicable to neutron-gamma discrimination for liquid scintillators and charged particles detected by Si detectors

Pulse discrimination of background and gamma-ray source by digital pulse shape discrimination in a BF3 detector

International Nuclear Information System (INIS)

Kim, Jinhyung; Kim, J. H.; Choi, H. D.

2014-01-01

As a representative method of non-destructive assay, accurate neutron measurement is difficult due to large background radiation such as γ-ray, secondary radiation, spurious pulse, etc. In a BF 3 detector, the process of signal generation is different between neutron and other radiations. As the development of detection technique, all of signal data can be digitized by digital measurement method. In the previous study, Applied Nuclear Physics Group in Seoul National University has developed digital Pulse Shape Discrimination (PSD) method using digital oscilloscope. In this study, optimization of parameters for pulse discrimination is discussed and γ-ray region is determined by measuring 60 Co source. The background signal of BF 3 detector is discriminated by digital PSD system. Parameters for PSD are optimized through FOM calculation. And the γ-ray region is determined by measuring 60 Co source. In the future, the performance of developed system will be tested in low and high intensity neutron field

Evaluation of otolith shape as a tool for stock discrimination in marine fishes using Baltic Sea cod as a case study

DEFF Research Database (Denmark)

Hüssy, Karin; Mosegaard, Henrik; Albertsen, Christoffer Moesgaard

2016-01-01

demonstrate theinterplay of environmental, ontogenetic and genetic influences on otolith shape, which complicates theapplication of otolith shape for stock discrimination in mixed-stock scenarios. Rigours genetic validationand further studies on the temporal dynamics of shape formation are necessary.......In the Western Baltic Sea two genetically distinct cod stocks “Eastern Baltic cod” and “Western Balticcod” occur with considerable mixing of stocks. In this study we evaluated the applicability of otolithshape analysis for classification of individuals caught in the mixed stock cod fishery, using...... SNP (singlenucleotide polymorphism) based genetic assignment of otolith shape baselines. We further developeda management aimed approach for mixed stock assignment by robust stochastic baseline selection andposterior bias correction by individual reassignment of the least likely classifications...

Fast neutron spectrometer with pulse shape discrimination

International Nuclear Information System (INIS)

Verbitsky, S.S.

1978-01-01

A fast neutron spectrometer with a stilbene single crystal designed to operate at high pulsed count rate has been described. Making use of identification and rejection of events, accompanied by pile-up, allowed to increase permissible count rates by an order of magnitude. The results of energy dependence of signal amplitude and shape relative anisotropy in stilbene in the range 4-10 and 2-8 MeV respectively have been presented. Taking into account anisotropy of the detector-scintillation properties allowed to improve particle discrimination. (Auth.)

The efficient neutron-gamma pulse shape discrimination with small active volume scintillation detector

International Nuclear Information System (INIS)

Phan Van Chuan; Nguyen Duc Hoa; Nguyen Xuan Hai; Nguyen Ngoc Anh; Tuong Thi Thu Huong; Nguyen Nhi Dien; Pham Dinh Khang

2016-01-01

A small detector with EJ-301 liquid scintillation was manufactured for the study on the neutron-gamma pulse shape discrimination. In this research, four algorithms, including Threshold crossing time (TCT), Pulse gradient analysis (PGA), Charge comparison method (CCM), and Correlation pattern recognition (CPR) were developed and compared in terms of their discrimination effectiveness between neutrons and gamma rays. The figures of merits (FOMs) obtained for 100 ÷ 2000 keVee (keV energy electron equivalent) neutron energy range show the charge comparison method was the most efficient of the four algorithms. (author)

Shape discrimination by total curvature, with a view to cancer diagnostics

DEFF Research Database (Denmark)

Gardner, R.J.; Hobolth, Asger; Jensen, Eva Bjørn Vedel

2005-01-01

This paper investigates the use of total curvature for shape discrimination of objects via profiles of their planar sections (not assumed to be star shaped). Methods of estimating total curvature from observation of a finite number of points on the boundary of the object are investigated, includi...... a simple discrete approximation method and various interpolation methods. Total curvature is capable of revealing shape differences on a local scale, as demonstrated by the analysis of two data sets of malignant and normal or benign tumour cell nuclear profiles....

2-Dimension pulse shape discriminator for phoswich detector based on FPGA

International Nuclear Information System (INIS)

Ji Jianfeng; Liu Congzhan; Zhang Zhi

2011-01-01

It improves the data acquire system for the pulse signal based on digital front-rear pulse shape discrimination system. It adds pulse width information into the pulse's data package. Base on this, we divide the pulse event process into two process, on line coast process and offline accurate process: the online process sets a big threshold, just save the data of the event below this threshold; the offline process uses the acquired data, get the pulse amplitude and pulse width, and then according the spectrum's real shape, set the accurate threshold. this design resolves the problem that the detector's decay time change with the temperature; at the same time, it can correct the system's distortion when the input signal at small amplitude, improves the discrimination system's accuracy. (authors)

Application of the pulse-shape technique to proton-alpha discrimination in Si-detector arrays

International Nuclear Information System (INIS)

Pausch, G.; Moszynski, M.; Wolski, D.; Bohne, W.; Grawe, H.; Hilscher, D.; Schubart, R.; De Angelis, G.; De Poli, M.

1995-04-01

The capability of the pulse-shape technique with reversed n-type Si detectors for discrimination of protons and alphas produced in fusion-evaporation reactions was tested at the VICKSI cyclotron in Berlin. We applied a zero-crossing technique which does not need any external time reference, and which can therefore be exploited at DC accelerators. Excellent proton-alpha discrimination in the full energy range of the evaporation spectra, but also charge and even isotope resolution for heavier ions produced in projectile fragmentation, was obtained with detectors of an existing Si ball. There is no doubt that the pulse-shape discrimination works well with detectors from serial production and under experimental conditions which are typical for nuclear structure studies. An application of this technique in Si detector arrays is obvious, but some special features must be considered in the design of the electronics. The particle discrimination depends strongly on the electric field distribution inside the detector. Stabilization of the bias voltage at the detector is therefore recommended. A consequence of the rear-side injection mode is a strong variation of the charge-collection time with energy, charge, and mass number of the detected ion. To obtain a precise energy signal it is indispensable to correct for the ballistic deficit. (orig.)

Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

Directory of Open Access Journals (Sweden)

Shuzhi Sam Ge

2011-09-01

Full Text Available One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects’ shapes and, more specifically, the objects’ surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB, Artificial Neural Networks (ANN, and Support Vector Machines (SVM were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

Hadronic vs. electromagnetic pulse shape discrimination in CsI(Tl) for high energy physics experiments

Science.gov (United States)

Longo, S.; Roney, J. M.

2018-03-01

Pulse shape discrimination using CsI(Tl) scintillators to perform neutral hadron particle identification is explored with emphasis towards application at high energy electron-positron collider experiments. Through the analysis of the pulse shape differences between scintillation pulses from photon and hadronic energy deposits using neutron and proton data collected at TRIUMF, it is shown that the pulse shape variations observed for hadrons can be modelled using a third scintillation component for CsI(Tl), in addition to the standard fast and slow components. Techniques for computing the hadronic pulse amplitudes and shape variations are developed and it is shown that the intensity of the additional scintillation component can be computed from the ionization energy loss of the interacting particles. These pulse modelling and simulation methods are integrated with GEANT4 simulation libraries and the predicted pulse shape for CsI(Tl) crystals in a 5 × 5 array of 5 × 5 × 30 cm3 crystals is studied for hadronic showers from 0.5 and 1 GeV/c KL0 and neutron particles. Using a crystal level and cluster level approach for photon vs. hadron cluster separation we demonstrate proof-of-concept for neutral hadron detection using CsI(Tl) pulse shape discrimination in high energy electron-positron collider experiments.

Pile-up and defective pulse rejection by pulse shape discrimination in surface barrier detectors

International Nuclear Information System (INIS)

Sjoeland, K.A.; Kristiansson, P.

1994-01-01

A technique to reject pile-up pulses and defective tail pulses from surface barrier detectors by the use of pulse shape discrimination is demonstrated. The electronic implementation of the pulse shape discrimination is based upon the zero crossing technique and for data reduction multiparameter techniques are used. The characteristic τ value for pile-up rejection is shown to be less than 56 ns. Its effect on detection limits from tail reduction in Particle Elastic Scattering Analysis (PESA) and pile-up peak suppression is discussed. ((orig.))

Pulse-shape discrimination in NE213 liquid scintillator detectors

International Nuclear Information System (INIS)

Cavallaro, M.; Tropea, S.; Agodi, C.; Assié, M.; Azaiez, F.; Boiano, C.; Bondì, M.; Cappuzzello, F.; Carbone, D.; De Napoli, M.; Séréville, N. de; Foti, A.; Linares, R.; Nicolosi, D.; Scarpaci, J.A.

2013-01-01

The 16-channel fast stretcher BaFPro module, originally developed for processing signals of Barium Fluoride scintillators, has been modified to make a high performing analog pulse-shape analysis of signals from the NE213 liquid scintillators of the EDEN neutron detector array. The module produces two Gaussian signals, whose amplitudes are proportional to the height of the fast component of the output light and to the total energy deposited into the scintillator, respectively. An in-beam test has been performed at INFN-LNS (Italy) demonstrating a low detection threshold, a good pulse-shape discrimination even at low energies and a wide dynamic range for the measurement of the neutrons energy.

Fast neutron flux analyzer with real-time digital pulse shape discrimination

Energy Technology Data Exchange (ETDEWEB)

Ivanova, A.A., E-mail: a.a.ivanova@inp.nsk.su [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Zubarev, P.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Ivanenko, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Khilchenko, A.D. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Kotelnikov, A.I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Polosatkin, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Puryga, E.A.; Shvyrev, V.G. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Sulyaev, Yu.S. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

2016-08-11

Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL–3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL–3 and GDT devices. This analyzer was tested and calibrated with the help of {sup 137}Cs and {sup 252}Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented. - Highlights: • Electronic equipment for measurement of fast neutron flux with stilbene scintillator is presented. • FPGA-implemented digital pulse-shape discrimination algorithm by charge comparison method is shown. • Calibration of analyzer was carried out with {sup 137}Cs and {sup 252}Cf. • Figures of Merit (FOM) values for energy cuts from 1/8 Cs to 2 Cs are from 1.264 to 2.34 respectively.

Experimental tests of the new plastic scintillator with pulse shape discrimination capabilities EJ-299-33

Energy Technology Data Exchange (ETDEWEB)

Cester, D., E-mail: davide.cester@gmail.com [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Nebbia, G. [INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Stevanato, L. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Pino, F. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Apartado 89000, 1080 A Caracas (Venezuela, Bolivarian Republic of); Viesti, G. [Dipartimento di Fisica ed Astronomia dell' Università di Padova, Via Marzolo 8, I-35131 Padova (Italy)

2014-01-21

We have studied the prototype of a new plastic scintillator material (EJ-299-33) engineered for gamma-neutron discrimination. Energy and time resolutions as well as pulse shape discrimination capability have been compared with those of standard plastic and liquid scintillators. EJ-299-33 characteristics are somewhat poorer compared to standard scintillators. However, results obtained with the new plastic material suggest its possible use in basic research (time-of-flight measurements) as well as in Homeland Security applications (neutron/gamma monitoring device)

Triple pulse shape discrimination and capture-gated spectroscopy in a composite heterogeneous scintillator

Energy Technology Data Exchange (ETDEWEB)

Sharma, M., E-mail: mksharma@umich.edu [University of Michigan, Ann Arbor, MI 48109 (United States); Nattress, J. [University of Michigan, Ann Arbor, MI 48109 (United States); Wilhelm, K. [Pennsylvania State University, University Park, PA 16802 (United States); Jovanovic, I. [University of Michigan, Ann Arbor, MI 48109 (United States)

2017-06-11

We demonstrate an all-solid-state design for a composite heterogeneous scintillation detector sensitive to interactions with high-energy photons (gammas), fast neutrons, and thermal neutrons. The scintillator exhibits triple pulse shape discrimination, effectively separating electron recoils, fast neutron recoils, and neutron captures. This is accomplished by combining the properties of two distinct scintillators, whereby a 51-mm diameter, 51-mm tall cylinder of pulse shape discriminating plastic is wrapped by a 320-µm thick sheet of {sup 6}LiF:ZnS(Ag), optically coupling the scintillators to each other and to the photomultiplier tube. In this way, the sensitivity to neutron captures is achieved without the need to load the plastic scintillator with a capture agent. We demonstrate a figure of merit of up to 1.2 for fast neutrons/gammas and 5.7 for thermal neutrons/gammas. Intrinsic capture efficiency is found to be 0.46±0.05% and is in good agreement with simulation, while gamma rejection was 10{sup −6} with respect to the capture region and 10{sup −4} with respect to the recoil region using a 300 keVee threshold. Finally, we show an improvement in capture-gated neutron spectroscopy by rejecting accidental gamma coincidences using pulse shape discrimination in the plastic scintillator.

Recent developments in plastic scintillators with pulse shape discrimination

Science.gov (United States)

Zaitseva, N. P.; Glenn, A. M.; Mabe, A. N.; Carman, M. L.; Hurlbut, C. R.; Inman, J. W.; Payne, S. A.

2018-05-01

The paper reports results of studies conducted to improve scintillation performance of plastic scintillators capable of neutron/gamma pulse-shape discrimination (PSD). Compositional modifications made with the polymer matrix improved physical stability, allowing for increased loads of the primary dye that, in combination with selected secondary dyes, provided enhanced PSD especially important for the lower energy ranges. Additional measurements were made with a newly-introduced PSD plastic EJ-276, that replaces the first commercially produced EJ-299. Comparative studies conducted with the new materials and EJ-309 liquids at large scale (up to 10 cm) show that current plastics may provide scintillation and PSD performance sufficient for the replacement of liquid scintillators. Comparison to stilbene single crystals compliments the information about the status of the solid-state materials recently developed for fast neutron detection applications.

Otolith shape analysis for stock discrimination of two Collichthys genus croaker (Pieces: Sciaenidae,) from the northern Chinese coast

Science.gov (United States)

Zhao, Bo; Liu, Jinhu; Song, Junjie; Cao, Liang; Dou, Shuozeng

2017-08-01

The otolith morphology of two croaker species (Collichthys lucidus and Collichthys niveatus) from three areas (Liaodong Bay, LD; Huanghe (Yellow) River estuary, HRE; Jiaozhou Bay, JZ) along the northern Chinese coast were investigated for species identification and stock discrimination. The otolith contour shape described by elliptic Fourier coefficients (EFC) were analysed using principal components analysis (PCA) and stepwise canonical discriminant analysis (CDA) to identify species and stocks. The two species were well differentiated, with an overall classification success rate of 97.8%. And variations in the otolith shapes were significant enough to discriminate among the three geographical samples of C. lucidus (67.7%) or C. niveatus (65.2%). Relatively high mis-assignment occurred between the geographically adjacent LD and HRE samples, which implied that individual mixing may exist between the two samples. This study yielded information complementary to that derived from genetic studies and provided information for assessing the stock structure of C. lucidus and C. niveatus in the Bohai Sea and the Yellow Sea.

Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

Energy Technology Data Exchange (ETDEWEB)

Hochel, R C; Hayes, D W [Du Pont de Nemours (E.I.) and Co., Aiken, S.C. (USA). Savannah River Lab.

1975-12-01

A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background.

Exploring laterality and memory effects in the haptic discrimination of verbal and non-verbal shapes.

Science.gov (United States)

Stoycheva, Polina; Tiippana, Kaisa

2018-03-14

The brain's left hemisphere often displays advantages in processing verbal information, while the right hemisphere favours processing non-verbal information. In the haptic domain due to contra-lateral innervations, this functional lateralization is reflected in a hand advantage during certain functions. Findings regarding the hand-hemisphere advantage for haptic information remain contradictory, however. This study addressed these laterality effects and their interaction with memory retention times in the haptic modality. Participants performed haptic discrimination of letters, geometric shapes and nonsense shapes at memory retention times of 5, 15 and 30 s with the left and right hand separately, and we measured the discriminability index d'. The d' values were significantly higher for letters and geometric shapes than for nonsense shapes. This might result from dual coding (naming + spatial) or/and from a low stimulus complexity. There was no stimulus-specific laterality effect. However, we found a time-dependent laterality effect, which revealed that the performance of the left hand-right hemisphere was sustained up to 15 s, while the performance of the right-hand-left hemisphere decreased progressively throughout all retention times. This suggests that haptic memory traces are more robust to decay when they are processed by the left hand-right hemisphere.

Development of a homogeneous pulse shape discriminating flow-cell radiation detection system

International Nuclear Information System (INIS)

Hastie, K.H.; DeVol, T.A.; Fjeld, R.A.

1999-01-01

A homogeneous flow-cell radiation detection system which utilizes coincidence counting and pulse shape discrimination circuitry was assembled and tested with five commercially available liquid scintillation cocktails. Two of the cocktails, Ultima Flo (Packard) and Mono Flow 5 (National Diagnostics) have low viscosities and are intended for flow applications; and three of the cocktails, Optiphase HiSafe 3 (Wallac), Ultima Gold AB (Packard), and Ready Safe (Beckman), have higher viscosities and are intended for static applications. The low viscosity cocktails were modified with 1-methylnaphthalene to increase their capability for alpha/beta pulse shape discrimination. The sample loading and pulse shape discriminator setting were optimized to give the lowest minimum detectable concentration for methylnaphthalenein a 30 s count time. Of the higher viscosity cocktails, Optiphase HiSafe 3 had the lowest minimum detectable activities for alpha and beta radiation, 0.2 and 0.4 Bq/ml for 233 U and 90 Sr/ 90 Y, respectively, for a 30 s count time. The sample loading was 70% and the corresponding alpha/beta spillover was 5.5%. Of the low viscosity cocktails, Mono Flow 5 modified with 2.5% (by volume) 1-methylnaphthalene resulted in the lowest minimum detectable activities for alpha and beta radiation; 0.3 and 0.5 Bq/ml for 233 U and 90 Sr/ 90 Y, respectively, for a 30 s count time. The sample loading was 50%, and the corresponding alpha/beta spillover was 16.6%. HiSafe 3 at a 10% sample loading was used to evaluate the system under simulated flow conditions

Performance of n-γ pulse-shape discrimination with simple pile-up rejection at high γ-ray count rates

International Nuclear Information System (INIS)

Okuda, T.; Yamazaki, H.; Kawabata, M.; Kasagi, J.; Harada, H.

1999-01-01

The performance of n-γ pulse-shape discrimination for a liquid scintillation detector has been investigated for γ-ray count rates up to 50 kcps. A method in which the ratio of the total to partial charge in the anode pulse is directly measured has shown much improved quality of the pulse-shape discrimination when pile-up events are rejected; it can discriminate neutron events of 50 cps from γ-ray events of 29 kcps. The method with simple pile-up rejection has the advantage that only general purpose electronics are required

A triple-crystal phoswich detector with digital pulse shape discrimination for alpha/beta/gamma spectroscopy

International Nuclear Information System (INIS)

White, Travis L.; Miller, William H.

1999-01-01

Researchers at the University of Missouri - Columbia have developed a three-crystal phoswich detector coupled to a digital pulse shape discrimination system for use in alpha/beta/gamma spectroscopy. Phoswich detectors use a sandwich of scintillators viewed by a single photomultiplier tube to simultaneously detect multiple types of radiation. Separation of radiation types is based upon pulse shape difference among the phosphors, which has historically been performed with analog circuitry. The system uses a GaGe CompuScope 1012, 12 bit, 10 MHz computer-based oscilloscope that digitally captures the pulses from a phoswich detector and subsequently performs pulse shape discrimination with cross-correlation analysis. The detector, based partially on previous phoswich designs by Usuda et al., uses a 10 mg/cm 2 thick layer of ZnS(Ag) for alpha detection, followed by a 0.254 cm CaF 2 (Eu) crystal for beta detection, all backed by a 2.54 cm NaI(Tl) crystal for gamma detection. Individual energy spectra and count rate information for all three radiation types are displayed and updated periodically. The system shows excellent charged particle discrimination with an accuracy of greater than 99%. Future development will include a large area beta probe with gamma-ray discrimination, systems for low-energy photon detection (e.g. Bremsstrahlung or keV-range photon emissions), and other health physics instrumentation

Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

International Nuclear Information System (INIS)

Hochel, R.C.; Hayes, D.W.

1975-01-01

A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background. (Auth.)

Pulse shape discrimination of plastic scintillator EJ 299-33 with radioactive sources

Science.gov (United States)

Pagano, E. V.; Chatterjee, M. B.; De Filippo, E.; Russotto, P.; Auditore, L.; Cardella, G.; Geraci, E.; Gnoffo, B.; Guazzoni, C.; Lanzalone, G.; De Luca, S.; Maiolino, C.; Martorana, N. S.; Pagano, A.; Papa, M.; Parsani, T.; Pirrone, S.; Politi, G.; Porto, F.; Quattrocchi, L.; Rizzo, F.; Trifirò, A.; Trimarchi, M.

2018-05-01

The present study has been carried out in order to investigate about the possibility of using EJ 299-33 scintillator in a multi-detector array to detect neutrons along with light charged particles. In a reaction induced by stable and exotic heavy-ions beams, where copious production of neutrons and other light charged particles occurs, discrimination with low identification threshold of these particles are of great importance. In view of this, EJ 299-33 scintillator having dimension of 3 cm × 3 cm × 3 cm backed by a photomultiplier tube was tested and used under vacuum to detect neutrons, gamma-rays and alpha particles emitted by radioactive sources. Anode pulses from the photomultiplier tube were digitized through GET electronics, recorded and stored in a data acquisition system for the purpose of an off-line analysis. The measurements, under vacuum and low background conditions, show good pulse shape discrimination properties characterized by low identification threshold for neutrons, gamma-rays and alpha particles. The Figures of Merit for neutron-gamma and alpha particles-gamma discriminations have been evaluated together with the energy resolution for gamma-ray and alpha particles.

A pulse shape discriminator with high precision of neutron and gamma ray selection at high counting rate

International Nuclear Information System (INIS)

Bialkowski, J.; Moszynski, M.; Wolski, D.

1989-01-01

A pulse shape discriminator based on the zero-crossing principle is described. Due to dc negative feedback loops stabilizing the shaping amplifier and the zero-crossing discriminator, the working of the circuit is not affected by the high counting rate and the temperature variations. The pileup rejection circuit built into the discriminator improves the quality of the n-γ separation at high counting rates. A full γ-ray rejection is obtained for a recoil energy of electrons down to 25 keV. At high counting rates the remaining γ-ray contribution is evidently due to the pileup effect which is equal to about 2% at 4x10 5 counts/s. (orig.)

Application of otolith shape analysis for stock discrimination and species identification of five goby species (Perciformes: Gobiidae) in the northern Chinese coastal waters

Science.gov (United States)

Yu, Xin; Cao, Liang; Liu, Jinhu; Zhao, Bo; Shan, Xiujuan; Dou, Shuozeng

2014-09-01

We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species ( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices (83.7%), elliptic Fourier coefficients (98.6%), or the combination of both methods (94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks (Liaodong Bay, LD; Bohai Bay, BH; Huanghe (Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta (50%-54%) and C. stigmatias (65.7%-75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone (70.2%) or in combination with shape indices (75.8%) than using only shape indices (65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.

Neutron-Gamma Pulse Shape Discrimination With Ne-213 Liquid Scintillator By Using Digital Signal Processing Combined With Similarity Method

International Nuclear Information System (INIS)

Mardiyanto

2008-01-01

Neutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method. Measurement of mixed neutron-gamma radiation is difficult because a nuclear detector is usually sensitive to both radiations. A new attempt of neutron-gamma pulse shape discrimination for a NE-213 liquid scintillator is presented by using digital signal processing combined with an off-line similarity method. The output pulse shapes are digitized with a high speed digital oscilloscope. The n-γ discrimination is done by calculating the index of each pulse shape, which is determined by the similarity method, and then fusing it with its corresponding pulse height. Preliminary results demonstrate good separation of neutron and gamma-ray signals from a NE-213 scintillator with a simple digital system. The results were better than those with a conventional rise time method. Figure of Merit is used to determine the quality of discrimination. The figure of merit of the discrimination using digital signal processing combined with off-line similarity method are 1.9; 1.7; 1.1; 1.1; and 0.8; on the other hand by using conventional method the rise time are 0.9; 0.9; 0.9; 0.7; and 0.4 for the equivalent electron energy of 800; 278; 139; 69; and 30 keV. (author)

Pulse shape discrimination and classification methods for continuous depth of interaction encoding PET detectors

International Nuclear Information System (INIS)

Roncali, Emilie; Phipps, Jennifer E; Marcu, Laura; Cherry, Simon R

2012-01-01

In previous work we demonstrated the potential of positron emission tomography (PET) detectors with depth-of-interaction (DOI) encoding capability based on phosphor-coated crystals. A DOI resolution of 8 mm full-width at half-maximum was obtained for 20 mm long scintillator crystals using a delayed charge integration linear regression method (DCI-LR). Phosphor-coated crystals modify the pulse shape to allow continuous DOI information determination, but the relationship between pulse shape and DOI is complex. We are therefore interested in developing a sensitive and robust method to estimate the DOI. Here, linear discriminant analysis (LDA) was implemented to classify the events based on information extracted from the pulse shape. Pulses were acquired with 2×2×20 mm 3 phosphor-coated crystals at five irradiation depths and characterized by their DCI values or Laguerre coefficients. These coefficients were obtained by expanding the pulses on a Laguerre basis set and constituted a unique signature for each pulse. The DOI of individual events was predicted using LDA based on Laguerre coefficients (Laguerre-LDA) or DCI values (DCI-LDA) as discriminant features. Predicted DOIs were compared to true irradiation depths. Laguerre-LDA showed higher sensitivity and accuracy than DCI-LDA and DCI-LR and was also more robust to predict the DOI of pulses with higher statistical noise due to low light levels (interaction depths further from the photodetector face). This indicates that Laguerre-LDA may be more suitable to DOI estimation in smaller crystals where lower collected light levels are expected. This novel approach is promising for calculating DOI using pulse shape discrimination in single-ended readout depth-encoding PET detectors. (paper)

Simulating response functions and pulse shape discrimination for organic scintillation detectors with Geant4

Energy Technology Data Exchange (ETDEWEB)

Hartwig, Zachary S., E-mail: hartwig@psfc.mit.edu [Department of Nuclear Science and Engineering, MIT, Cambridge MA (United States); Gumplinger, Peter [TRIUMF, Vancouver, BC (Canada)

2014-02-11

We present new capabilities of the Geant4 toolkit that enable the precision simulation of organic scintillation detectors within a comprehensive Monte Carlo code for the first time. As of version 10.0-beta, the Geant4 toolkit models the data-driven photon production from any user-defined scintillator, photon transportation through arbitrarily complex detector geometries, and time-resolved photon detection at the light readout device. By fully specifying the optical properties and geometrical configuration of the detector, the user can simulate response functions, photon transit times, and pulse shape discrimination. These capabilities enable detector simulation within a larger experimental environment as well as computationally evaluating novel scintillators, detector geometry, and light readout configurations. We demonstrate agreement of Geant4 with the NRESP7 code and with experiments for the spectroscopy of neutrons and gammas in the ranges 0–20 MeV and 0.511–1.274 MeV, respectively, using EJ301-based organic scintillation detectors. We also show agreement between Geant4 and experimental modeling of the particle-dependent detector pulses that enable simulated pulse shape discrimination. -- Highlights: • New capabilities enable the modeling of organic scintillation detectors in Geant4. • Detector modeling of complex scintillators, geometries, and light readout. • Enables particle- and energy-dependent production of scintillation photons. • Provides ability to generate response functions with precise optical physics. • Provides ability to computationally evaluate pulse shape discrimination.

Reinforcement shapes clines in female mate discrimination in Drosophila subquinaria

Science.gov (United States)

Bewick, Emily R.; Dyer, Kelly A.

2014-01-01

Reinforcement of species boundaries may alter mate recognition in a way that also affects patterns of mate preference among conspecific populations. In the fly Drosophila subquinaria, females sympatric with the closely related species D. recens reject mating with heterospecific males as well as with conspecific males from allopatric populations. Here, we assess geographic variation in behavioral isolation within and among populations of D. subquinaria and use cline theory to understand patterns of selection on reinforced discrimination and its consequences for sexual isolation within species. We find that selection has fixed rejection of D. recens males in sympatry, while significant genetic variation in this behavior occurs within allopatric populations. In conspecific matings sexual isolation is also asymmetric and stronger in populations that are sympatric with D. recens. The clines in behavioral discrimination within and between species are similar in shape and are maintained by strong selection in the face of gene flow, and we show that some of their genetic basis may be either shared or linked. Thus, while reinforcement can drive extremely strong phenotypic divergence, the long-term consequences for incipient speciation depend on gene flow, genetic linkage of discrimination traits, and the cost of these behaviors in allopatry. PMID:25163510

Pulse-shape discrimination of high-energy neutrons and gamma rays in NaI(Tl)

International Nuclear Information System (INIS)

Share, G.H.; Kurfess, J.D.; Theus, R.B.

1978-01-01

Pulse-shape discrimination can be used to separate neutron and gamma-ray interactions depositing energies up to in excess of 50 MeV in NaI(Tl) crystals. The secondary alpha particles, deuterons and protons produced in the neutron interactions are also resolvable. (Auth.)

Stigma, discrimination and agency: Diagnostic disclosure as an everyday practice shaping social citizenship.

Science.gov (United States)

O'Connor, Deborah; Mann, Jim; Wiersma, Elaine

2018-03-01

The importance of stigma in shaping the experiences of people living with dementia and challenging their social citizenship emerges repeatedly as a powerful and negative force. In a recent participatory action research (PAR) study focused on understanding what people with dementia need to know to live well, this link between stigma, discrimination and social citizenship emerged once again. A group of people living with dementia (n=8) met monthly for 16months to discuss their experiences and advise on the curriculum of a proposed self-management program. From the first introduction, stigma was identified as a defining feature of the experience of living well with dementia. This paper analyses this group's talk around stigma and discrimination, drawing attention to the critical role that diagnostic disclosure has in both positioning people with dementia in a stigmatizing way and, also, acting as a strategy of resistance that facilitates full social citizenship. Copyright © 2018 Elsevier Inc. All rights reserved.

Study of n-γ discrimination using QDC for a liquid scintillator

International Nuclear Information System (INIS)

Jhingan, Akhil; Singh, R.P.; Golda, K.S.; Sugathan, P.; Bhowmik, R.K.; Singh, Hardev

2006-01-01

An array of neutron detectors has been recently installed in beam hall II at Inter University Accelerator Centre, New Delhi. The array currently has 26 neutron detectors with some detectors pooled from SINP, Kolkata. For some in beam test experiments and off line source tests, zero crossing technique has been successfully used for n-γ discrimination, using commercially available pulse shape discriminator module 2160A from Canberra, as well as with in house designed and fabricated pulse shape discriminator module using zero crossing technique

Evaluation of polymer-coated CsI:Tl as an alpha/beta pulse shape discriminating flow-cell

International Nuclear Information System (INIS)

Branton, S.D.; Fjeld, R.A.; DeVol, T.A.

1996-01-01

A pulse shape discriminating flow-cell radiation detection system constructed with polymer coated CsI:Tl was evaluated for simultaneous gross alpha/gross beta quantification. The CsI:TI scintillator was crushed and sieved to 63-90 μm particle size and microencapsulated with Parylene C to reduce its rate of dissolution. Averaged over the first hour of use, the pulse shape discrimination figure-of-merit was 1.4 and the detection efficiencies were 64.9 ± 5.7 %, 52.5 ± 4.5 % and 4.5 ± 0.2 % for 233 U, 90 Sr/ 90 Y and 14 C , respectively. The typical background count rate in the alpha and beta pulse shape window was 0.17 and 0.004 cps, respectively. The resultant minimum detectable activity for a 30 second count time was calculated to be 0.19 ± 0.01 Bq, 0.9 ± 0.1 Bq and 11.4 ± 0.6 Bq for 233 U, 90 Sr/ 90 Y and 14 C, respectively. Although the 3 μm thick microencapsulation reduced CsI:Tl dissolution, the detection efficiency declined by a factor of two after 4.8 hours while the pulse shape resolution degraded slightly

Neutron–gamma discrimination based on bipolar trapezoidal pulse shaping using FPGAs in NE213

International Nuclear Information System (INIS)

Esmaeili-sani, Vahid; Moussavi-zarandi, Ali; Akbar-ashrafi, Nafiseh; Boghrati, Behzad; Afarideh, Hossein

2012-01-01

A technique employing neutron–gamma pulse shape discrimination (PSD) system that overcomes pile up limitations of previous methods to distinguish neutrons from gammas in scintillation detectors is described. The output signals of detectors were digitized and processed with a data acquisition system based on bipolar trapezoidal pulse shaping using Field programmable gate arrays (FPGA). FPGAs are capable of doing complex discrete signal processing algorithms with clock rates above 100 MHz. Their low cost, ease of use and selected dedicated hardware make them an ideal option for spectrometer systems.

Neutron-gamma discrimination based on bipolar trapezoidal pulse shaping using FPGAs in NE213

Energy Technology Data Exchange (ETDEWEB)

Esmaeili-sani, Vahid, E-mail: vaheed_esmaeely80@yahoo.com [Department of Nuclear Engineering and Physics, Amirkabir University of Technology, P.O. Box 4155-4494, Tehran (Iran, Islamic Republic of); Moussavi-zarandi, Ali; Akbar-ashrafi, Nafiseh; Boghrati, Behzad; Afarideh, Hossein [Department of Nuclear Engineering and Physics, Amirkabir University of Technology, P.O. Box 4155-4494, Tehran (Iran, Islamic Republic of)

2012-12-01

A technique employing neutron-gamma pulse shape discrimination (PSD) system that overcomes pile up limitations of previous methods to distinguish neutrons from gammas in scintillation detectors is described. The output signals of detectors were digitized and processed with a data acquisition system based on bipolar trapezoidal pulse shaping using Field programmable gate arrays (FPGA). FPGAs are capable of doing complex discrete signal processing algorithms with clock rates above 100 MHz. Their low cost, ease of use and selected dedicated hardware make them an ideal option for spectrometer systems.

Tests on a digital neutron-gamma pulse shape discriminator with NE213

International Nuclear Information System (INIS)

Bell, Z.W.

1981-01-01

A technique using charge sensitive analog-to-digital converters to do neutron-gamma pulse shape discrimination is reported. The converters are gated by short (135 ns) pulses so as to reduce pile-up and the timing is such that the slow and total light output from the scintillator are measured. Preliminary tests indicate that the system performs reasonably well but poorer than some reported analog systems employing gated integrators or cross-over techniques. (orig.)

A comparison of two methods of pulse-shape discrimination for alpha-gamma separation with trans-stilbene

International Nuclear Information System (INIS)

Shani, G.; Cojocaru, M.

1977-01-01

A method for measurement of low level alpha particles in high level gamma background is investigated. Because of its pulse-shape-discrimination properties and being a solid scintillator, trans-stilbene seems to be the proper scintillator, for this purpose. The investigation was done by measuring the effect of different gamma background level (from very low to very high) on constant alpha count rate. Two different pulse-shape-discrimination systems were used and compared. The Ortec system measures the pulse fall time and supplies a corresponding pulse height and the Elscint system checks whether the pulse is what is expected to be the gamma pulse, or is a longer pulse. Both systems yielded good results and were found to be adequate for alpha-gamma separation with trans-stilbene. (Auth.)

Pulse shape discrimination based on fast signals from silicon photomultipliers

Science.gov (United States)

Yu, Junhao; Wei, Zhiyong; Fang, Meihua; Zhang, Zixia; Cheng, Can; Wang, Yi; Su, Huiwen; Ran, Youquan; Zhu, Qingwei; Zhang, He; Duan, Kai; Chen, Ming; Liu, Meng

2018-06-01

Recent developments in organic plastic scintillators capable of pulse shape discrimination (PSD) enable a breakthrough in discrimination between neutrons and gammas. Plastic scintillator detectors coupled with silicon photomultipliers (SiPMs) offer many advantages, such as lower power consumption, smaller volume, and especially insensitivity to magnetic fields, compared with conventional photomultiplier tubes (PMTs). A SensL SiPM has two outputs: a standard output and a fast output. It is known that the charge injected into the fast output electrode is typically approximately 2% of the total charge generated during the avalanche, whereas the charge injected into the standard output electrode is nearly 98% of the total. Fast signals from SiPMs exhibit better performance in terms of timing and time-correlated measurements compared with standard signals. The pulse duration of a standard signal is on the order of hundreds of nanoseconds, whereas the pulse duration of the main monopole waveform of a fast signal is a few tens of nanoseconds. Fast signals are traditionally thought to be suitable for photon counting at very high speeds but unsuitable for PSD due to the partial charge collection. Meanwhile, the standard outputs of SiPMs coupled with discriminating scintillators have yielded nice PSD performances, but there have been no reports on PSD using fast signals. Our analysis shows that fast signals can also provide discrimination if the rate of charge injection into the fast output electrode is fixed for each event, even though only a portion of the charge is collected. In this work, we achieved successful PSD using fast signals; meanwhile, using a coincidence timing window of less 3 nanoseconds between the readouts from both ends of the detector reduced the influence of the high SiPM dark current. We experimentally achieved good timing performance and PSD capability simultaneously.

Digital pulse-shape discrimination applied to an ultra-low-background gas-proportional counting system. First results

International Nuclear Information System (INIS)

Aalseth, C.E.; Day, A.R.; Fuller, E.S.; Hoppe, E.W.; Keillor, M.E.; Mace, E.K.; Myers, A.W.; Overman, C.T.; Panisko, M.E.; Seifert, A.

2013-01-01

A new ultra-low-background proportional counter design was recently developed at Pacific Northwest National Laboratory (PNNL). This design, along with an ultra-low-background counting system which provides passive and active shielding with radon exclusion, has been developed to complement a new shallow underground laboratory (∼30 m 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 for 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. (author)

A 16-channel real-time digital processor for pulse-shape discrimination in multiplicity assay

International Nuclear Information System (INIS)

Joyce, Malcolm J.; Aspinall, M.D.; Cave, F.D.; Lavietes, A.

2013-06-01

In recent years, real-time neutron/γ-ray pulse-shape discrimination has become feasible for use with scintillator-based detectors that respond extremely quickly, on the order of 25 ns in terms of pulse width, and their application to a variety of nuclear material assays has been reported. For the in-situ analysis of nuclear materials, measurements are often based on the multiplicity assessment of spontaneous fission events. An example of this is the 240 Pu eff assessment stemming from long-established techniques developed for 3 He-based neutron coincidence counters when 3 He was abundant and cheap. However, such measurements when using scintillator detectors can be plagued by low detection efficiencies and low orders of coincidence (often limited to triples) if the number of detectors in use is similarly limited to 3-4 detectors. Conversely, an array of >10 detector modules arranged to optimize efficiency and multiplicity sensitivity, shifts the emphasis in terms of performance requirement to the real-time digital analyzer and, critically, to the scope remaining in the temporal processing window of these systems. In this paper we report on the design, development and commissioning of a bespoke, 16-channel real-time pulse-shape discrimination analyzer specified for the materials assay challenge summarized above. The analyzer incorporates 16 dedicated and independent high-voltage supplies along with 16 independent digital processing channels offering pulse-shape discrimination at a rate of 3 x 10 6 events per second. These functions are configured from a dedicated graphical user interface, and all settings can be adjusted on-the-fly with the analyzer effectively configured one-time-only (where desired) for subsequent plug-and-play connection, for example to a fuel bundle organic scintillation detector array. (authors)

Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

Energy Technology Data Exchange (ETDEWEB)

Lombigit, L., E-mail: lojius@nm.gov.my; Yussup, N., E-mail: nolida@nm.gov.my; Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M. [Instrumentation Group, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

2015-04-29

A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume.

Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

International Nuclear Information System (INIS)

Lombigit, L.; Yussup, N.; Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M.

2015-01-01

A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume

Visual feature discrimination versus compression ratio for polygonal shape descriptors

Science.gov (United States)

Heuer, Joerg; Sanahuja, Francesc; Kaup, Andre

2000-10-01

In the last decade several methods for low level indexing of visual features appeared. Most often these were evaluated with respect to their discrimination power using measures like precision and recall. Accordingly, the targeted application was indexing of visual data within databases. During the standardization process of MPEG-7 the view on indexing of visual data changed, taking also communication aspects into account where coding efficiency is important. Even if the descriptors used for indexing are small compared to the size of images, it is recognized that there can be several descriptors linked to an image, characterizing different features and regions. Beside the importance of a small memory footprint for the transmission of the descriptor and the memory footprint in a database, eventually the search and filtering can be sped up by reducing the dimensionality of the descriptor if the metric of the matching can be adjusted. Based on a polygon shape descriptor presented for MPEG-7 this paper compares the discrimination power versus memory consumption of the descriptor. Different methods based on quantization are presented and their effect on the retrieval performance are measured. Finally an optimized computation of the descriptor is presented.

Fast neutron detection using a new pulse shape discrimination technique: Charge sensitive integration

International Nuclear Information System (INIS)

Zucker, M.; Tsoupas, N.; Karwowski, H.; Castaneda, C.; Nimnual, S.; Porter, R.; Ward, T.

1988-01-01

A new electronic technique that depends on charge sensitive integration (CSI) has been developed and tested using a CAMAC based pulse shape discrimination system. Neutrons are well separated from γ-ray signals in the 0.1-100 MeV energy range. The new method was compared with the old zero-crossing time-to-amplitude differentiating technique and was found to be comparable in count rate and superior in noise suppression

Very low level α-particle detection by means of pulse shape discrimination

International Nuclear Information System (INIS)

Omori, M.

1993-01-01

A charge comparison pulse shape discriminator has been shown to be capable of low level alpha particle detection in a NE213 scintillator by discriminating against a high rate of gamma background. The clearly observed alpha peaks were due to 212 Po in 232 Th chain and 214 Po in 238 U chain with rates of 13.5/h and 15.6/h, and energies of 8.95 and 7.83 MeV respectively. For the 8.95 MeV alpha, the gamma background rate was reduced by a factor of 2.1 x 10 4 to a level of 22.5/h. The measurements were made in a low muon flux environment underground (1230 m deep). The detection limit for the alphas could be lowered to as low as 0.1-1 event per day deep underground by use of high purity PSD scintillators. (orig.)

Comparative study of large samples (2'' × 2'') plastic scintillators and EJ309 liquid with pulse shape discrimination (PSD) capabilities

International Nuclear Information System (INIS)

Iwanowska-Hanke, J; Moszynski, M; Swiderski, L; Sibczynski, P; Szczesniak, T; Krakowski, T; Schotanus, P

2014-01-01

In the paper we reported on the scintillation properties and pulse shape discrimination (PSD) performance of new plastic scintillators. The samples with dimension of 2 inches × 2 inches were tested: EJ299-34, EJ299-34G, EJ299-33 and EJ299-33G. They are the first commercially available plastics with neutron/gamma discrimination properties. The paper covers the measurements of emission spectra, photoelectron yield, analysis of the light pulse shapes originating from events related to gamma-rays and fast neutrons as well as neutron/gamma discrimination. The tested plastics are characterized by a photoelectron yield on a level of approximately 1600-2500 phe/MeV, depending on the sample. The highest value, measured for EJ299-34, is similar to the number of photoelectrons measured for EJ309 (2600 phe/MeV). The figure of merit (FOM) calculated for narrow energy cuts — indicating the PSD performance — showed that the PSD capabilities of the plastics are significantly lower than of EJ309. These scintillators are still under development in order to optimize the composition and manufacturing procedures. At this time the results obtained with the new plastics suggest their possible use as an alternative for liquid scintillators, especially if we consider their inflammability and non-toxicity

An alphaβgamma health physics instrument with pulse-shape discrimination

International Nuclear Information System (INIS)

McElhaney, S.A.; Chiles, M.M.; Ramsey, J.A.

1990-01-01

This paper reports on a recent breakthrough in alpha scintillation detector design which supports the feasibility of extending this new technology to the development of a monolithic alphaβgamma (αβγ) scintillation detector. The new scintillator is physically robust and chemically resistant to environmental conditions encountered in radiation monitoring, and yet inexpensive to manufacture. The use of pulse-shape discrimination electronics allows pulses from each scintillator to be separated for particle identification. An α β γ detector has a side variety of possible applications including laundry monitoring, wastewater monitoring, air sampling, and health physics instrumentation

Standardized Index of Shape (SIS): a quantitative DCE-MRI parameter to discriminate responders by non-responders after neoadjuvant therapy in LARC

Energy Technology Data Exchange (ETDEWEB)

Petrillo, Antonella; Fusco, Roberta; Petrillo, Mario; Granata, Vincenza [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy). Div. of Radiology; Sansone, Mario [Naples Univ. ' ' Federico II' ' (Italy). Dept. of Biomedical, Electronics and Telecommunications Engineering; Avallone, Antonio [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy). Div. of Gastrointestinal Medical Oncology; Delrio, Paolo [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy). Div. of Gastrointestinal surgical Oncology; Pecori, Biagio [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy). Div. of Radiotherapy; Tatangelo, Fabiana [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy). Div. of Diagnostic Pathology; Ciliberto, Gennaro [Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS, Naples (Italy)

2015-07-15

To investigate the potential of DCE-MRI to discriminate responders from non-responders after neoadjuvant chemo-radiotherapy (CRT) for locally advanced rectal cancer (LARC). We investigated several shape parameters for the time-intensity curve (TIC) in order to identify the best combination of parameters between two linear parameter classifiers. Seventy-four consecutive patients with LARC were enrolled in a prospective study approved by our ethics committee. Each patient gave written informed consent. After surgery, pathological TNM and tumour regression grade (TRG) were estimated. DCE-MRI semi-quantitative analysis (sqMRI) was performed to identify the best parameter or parameter combination to discriminate responders from non-responders in response monitoring to CRT. Percentage changes of TIC shape descriptors from the baseline to the presurgical scan were assessed and correlated with TRG. Receiver operating characteristic analysis and linear classifier were applied. Forty-six patients (62.2 %) were classified as responders, while 28 subjects (37.8 %) were considered as non-responders. sqMRI reached a sensitivity of 93.5 % and a specificity of 82.1 % combining the percentage change in Maximum Signal Difference (ΔMSD) and Wash-out Slope (ΔWOS), the Standardized Index of Shape (SIS). SIS obtains the best result in discriminating responders from non-responders after CRT in LARC, with a cut-off value of -3.0 %. (orig.)

Charged particle identification including Pions by pulse-shape discrimination with an NE213 liquid scintillator

International Nuclear Information System (INIS)

Nakamoto, T.; Ishibashi, K.; Matsufuji, N.; Shigyo, N.; Maehata, K.

1995-01-01

Particles emitted from spallation reactions induced by protons having GeV energies were measured with an NE213 liquid scintillator, 12.7 cm in diameter and 12.7 cm thick. The pulse-shape discrimination (PSD) was carried out for charged particle identification by the two-gate integration method. Pions having energies up to 60 MeV were clearly discriminated from protons and electrons. On the contrary, pions with higher energies could not be identified since they escaped from the detector. The advantage of PSD for charged particle identification is that there is no requirement for a ΔE detector in the measurements. copyright 1995 American Institute of Physics

Evaluation of removal of the size effect using data scaling and elliptic Fourier descriptors in otolith shape analysis, exemplified by the discrimination of two yellow croaker stocks along the Chinese coast

Science.gov (United States)

Zhao, Bo; Liu, Jinhu; Song, Junjie; Cao, Liang; Dou, Shuozeng

2017-11-01

Removal of the length effect in otolith shape analysis for stock identification using length scaling is an important issue; however, few studies have attempted to investigate the effectiveness or weakness of this methodology in application. The aim of this study was to evaluate whether commonly used size scaling methods and normalized elliptic Fourier descriptors (NEFDs) could effectively remove the size effect of fish in stock discrimination. To achieve this goal, length groups from two known geographical stocks of yellow croaker, Larimichthys polyactis, along the Chinese coast (five groups from the Changjiang River estuary of the East China Sea and three groups from the Bohai Sea) were subjected to otolith shape analysis. The results indicated that the variation of otolith shape caused by intra-stock fish length might exceed that due to inter-stock geographical separation, even when otolith shape variables are standardized with length scaling methods. This variation could easily result in misleading stock discrimination through otolith shape analysis. Therefore, conclusions about fish stock structure should be carefully drawn from otolith shape analysis because the observed discrimination may primarily be due to length effects, rather than differences among stocks. The application of multiple methods, such as otoliths shape analysis combined with elemental fingering, tagging or genetic analysis, is recommended for sock identification.

Interpersonal discrimination and markers of adiposity in longitudinal studies: a systematic review.

Science.gov (United States)

Bernardo, C de O; Bastos, J L; González-Chica, D A; Peres, M A; Paradies, Y C

2017-09-01

While the impact of interpersonal discrimination on mental health is well established, its effects on physical health outcomes have not been fully elucidated. This study systematically reviewed the literature on the prospective association between interpersonal discrimination and markers of adiposity. Medline, Web of Science, Scopus, PsycInfo, SciELO, LILACS, Google Scholar, Capes/Brazil and ProQuest databases were used to retrieve relevant information in November 2016. The results from the 10 studies that met the inclusion criteria support an association between interpersonal self-reported discrimination and the outcomes. In general, the most consistent findings were for weight and body mass index (BMI) among women, i.e. high levels of self-reported discrimination were related to increased weight and BMI. Waist circumference (WC) showed a similar pattern of association with discrimination, in a positive direction, but an inverted U-shaped association was also found. Despite a few inverse associations between discrimination and markers of adiposity, none of the associations were statistically significant. Overall, markers of adiposity were consistently associated with discrimination, mainly through direct and nonlinear associations. This review provides evidence that self-reported discrimination can play an important role in weight, BMI and WC changes. © 2017 World Obesity Federation.

Is interpolation cognitively encapsulated? Measuring the effects of belief on Kanizsa shape discrimination and illusory contour formation

Science.gov (United States)

Keane, Brian P.; Lu, Hongjing; Papathomas, Thomas V.; Silverstein, Steven M.; Kellman, Philip J.

2012-01-01

Contour interpolation is a perceptual process that fills-in missing edges on the basis of how surrounding edges (inducers) are spatiotemporally related. Cognitive encapsulation refers to the degree to which perceptual mechanisms act in isolation from beliefs, expectations, and utilities (Pylyshyn, 1999). Is interpolation encapsulated from belief? We addressed this question by having subjects discriminate briefly-presented, partially-visible fat and thin shapes, the edges of which either induced or did not induce illusory contours (relatable and non-relatable conditions, respectively). Half the trials in each condition incorporated task-irrelevant distractor lines, known to disrupt the filling-in of contours. Half of the observers were told that the visible parts of the shape belonged to a single thing (group strategy); the other half were told that the visible parts were disconnected (ungroup strategy). It was found that distractor lines strongly impaired performance in the relatable condition, but minimally in the non-relatable condition; that strategy did not alter the effects of the distractor lines for either the relatable or non-relatable stimuli; and that cognitively grouping relatable fragments improved performance whereas cognitively grouping non-relatable fragments did not. These results suggest that 1) filling-in effects during illusory contour formation cannot be easily removed via strategy; 2) filling-in effects cannot be easily manufactured from stimuli that fail to elicit interpolation; and 3) actively grouping fragments can readily improve discrimination performance, but only when those fragments form interpolated contours. Taken together, these findings indicate that discriminating filled-in shapes depends on strategy but filling-in itself may be encapsulated from belief. PMID:22440789

Hydrodynamic discrimination of wakes caused by objects of different size or shape in a harbour seal (Phoca vitulina)

DEFF Research Database (Denmark)

Wieskotten, S.; Mauck, B.; Miersch, L.

2011-01-01

Harbour seals can use their mystacial vibrissae to detect and track hydrodynamic wakes. We investigated the ability of a harbour seal to discriminate objects of different size or shape by their hydrodynamic signature and used particle image velocimetry to identify the hydrodynamic parameters...... that a seal may be using to do so. Hydrodynamic trails were generated by different sized or shaped paddles that were moved in the calm water of an experimental box to produce a characteristic signal. In a two-alternative forced-choice procedure the blindfolded subject was able to discriminate size differences...... of down to 3.6. cm (Weber fraction 0.6) when paddles were moved at the same speed. Furthermore the subject distinguished hydrodynamic signals generated by flat, cylindrical, triangular or undulated paddles of the same width. Particle image velocimetry measurements demonstrated that the seal could have...

Alpha-gamma pulse shape discrimination in CsI:Tl, CsI:Na and BaF sub 2 scintillators

CERN Document Server

Dinca, L E; Haas, J; Bom, V R; Eijk, C W E

2002-01-01

Some scintillating materials offer the possibility of measuring well separated alpha and gamma scintillation response using a single crystal. Eventually aiming at thermal neutron detection using sup 6 Li or sup 1 sup 0 B admixture, pulse shape discrimination measurements were made on three scintillators: CsI:Tl, CsI:Na and pure BaF sub 2 crystals. A very good alpha/gamma discrimination was obtained using sup 2 sup 2 Na, sup 2 sup 4 sup 1 Am (gamma) and sup 2 sup 4 sup 4 Cm (alpha) radioactive sources.

Consistency check of pulse shape discrimination for broad energy germanium detectors using double beta decay data

Energy Technology Data Exchange (ETDEWEB)

Liao, Heng-Ye [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GERDA-Collaboration

2013-07-01

The Gerda (GERmanium Detector Array) experiment was built to study fundamental neutrino properties via neutrinoless double beta decay (0νββ). 0νββ events are single-site events (SSE) confined to a scale about millimeter. However, most of backgrounds are multi-site events (MSE). Broad Energy Germanium detectors (BEGes) offer the potential merits of improved pulse shape recognition efficiencies of SSE/MSE. They allow us to reach the goal of Phase II with a background index of 10{sup -3} cts/(keV.kg.yr) in the ROI. BEGe detectors with a total target mass of 3.63 kg have been installed to the Gerda setup in the Laboratori Nazionali del Gran Sasso (LNGS) in July 2012 and are collecting data since. A consistency check of the pulse shape discrimination (PSD) efficiencies by comparison of calibration data and 2νββ data will be presented. The PSD power of these detectors is demonstrated.

Pulse shape discrimination performance of inverted coaxial Ge detectors

Science.gov (United States)

Domula, A.; Hult, M.; Kermaïdic, Y.; Marissens, G.; Schwingenheuer, B.; Wester, T.; Zuber, K.

2018-05-01

We report on the characterization of two inverted coaxial Ge detectors in the context of being employed in future 76Ge neutrinoless double beta (0 νββ) decay experiments. It is an advantage that such detectors can be produced with bigger Ge mass as compared to the planar Broad Energy Ge (BEGe) or p-type Point Contact (PPC) detectors that are currently used in the GERDA and MAJORANA DEMONSTRATOR 0 νββ decay experiments respectively. This will result in a lower background for the search of 0 νββ decay due to a reduction of detector surface to volume ratio, cables, electronics and holders which are dominating nearby radioactive sources. The measured resolution near the 76Ge Q-value at 2039 keV is 2.3 keV FWHM and their pulse-shape discrimination of background events are similar to BEGe and PPC detectors. It is concluded that this type of Ge-detector is suitable for usage in 76Ge 0 νββ decay experiments.

Otolith shape: a population marker for Atlantic herring Clupea harengus.

Science.gov (United States)

Libungan, L A; Óskarsson, G J; Slotte, A; Jacobsen, J A; Pálsson, S

2015-04-01

Otolith shape variation of seven Atlantic herring Clupea harengus populations from Canada, the Faroe Islands, Iceland, Ireland, Norway and Scotland, U.K., covering a large area of the species' distribution, was studied in order to see if otolith shape can be used to discriminate between populations. The otolith shape was obtained using quantitative shape analysis, transformed with Wavelet and analysed with multivariate methods. Significant differences were detected among the seven populations, which could be traced to three morphological structures in the otoliths. The differentiation in otolith shape between populations was not only correlated with their spawning time, indicating a strong environmental effect, but could also be due to differing life-history strategies. A model based on the shape differences discriminates with 94% accuracy between Icelandic summer spawners and Norwegian spring spawners, which are known to mix at feeding grounds. This study shows that otolith shape could become an accurate marker for C. harengus population discrimination. © 2015 The Fisheries Society of the British Isles.

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

International Nuclear Information System (INIS)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker

2015-01-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s -1 (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Study and understanding of n/γ discrimination processes in organic plastic scintillators

International Nuclear Information System (INIS)

Hamel, Matthieu; Blanc, Pauline; Rocha, Licinio; Normand, Stephane; Pansu, Robert

2013-01-01

For 50 years, it was assumed that unlike liquid scintillators or organic crystals, plastic scintillators were not able to discriminate fast neutrons from gamma. In this work, we will demonstrate that triplet-triplet annihilations (which are responsible of n/γ discrimination) can occur even in plastic scintillators, following certain conditions. Thus, the presentation will deal with the chemical preparation, the characterization and the comparison of n/γ pulse shape discrimination of various plastic scintillators. To this aim, scale-up of the process allowed us to prepare a O 100 mm x*110 mm thick. (authors)

Detecting hippocampal shape changes in Alzheimer's disease using statistical shape models

Science.gov (United States)

Shen, Kaikai; Bourgeat, Pierrick; Fripp, Jurgen; Meriaudeau, Fabrice; Salvado, Olivier

2011-03-01

The hippocampus is affected at an early stage in the development of Alzheimer's disease (AD). Using brain Magnetic Resonance (MR) images, we can investigate the effect of AD on the morphology of the hippocampus. Statistical shape models (SSM) are usually used to describe and model the hippocampal shape variations among the population. We use the shape variation from SSM as features to classify AD from normal control cases (NC). Conventional SSM uses principal component analysis (PCA) to compute the modes of variations among the population. Although these modes are representative of variations within the training data, they are not necessarily discriminant on labelled data. In this study, a Hotelling's T 2 test is used to qualify the landmarks which can be used for PCA. The resulting variation modes are used as predictors of AD from NC. The discrimination ability of these predictors is evaluated in terms of their classification performances using support vector machines (SVM). Using only landmarks statistically discriminant between AD and NC in SSM showed a better separation between AD and NC. These predictors also showed better correlation to the cognitive scores such as mini-mental state examination (MMSE) and Alzheimer's disease assessment scale (ADAS).

Neutron/gamma pulse shape discrimination in plastic scintillators: Preparation and characterization of various compositions

International Nuclear Information System (INIS)

Blanc, Pauline; Hamel, Matthieu; Dehé-Pittance, Chrystèle; Rocha, Licinio; Pansu, Robert B.; Normand, Stéphane

2014-01-01

This work deals with the preparation and evaluation of plastic scintillators for neutron/gamma pulse shape discrimination (PSD). We succeeded in developing a plastic scintillator with good neutron/gamma discrimination properties in the range of what is already being commercialized. Several combinations of primary and secondary fluorophores were implemented in chemically modified polymers. These scintillators were fully characterized by fluorescence spectroscopy and under neutron irradiation. The materials proved to be stable for up to 5 years without any degradation of PSD properties. They were then classified in terms of their PSD capabilities and light yield. Our best candidate, 28.6 wt% of primary fluorophore with a small amount of secondary fluorophore, shows promising PSD results and is particularly suited to industrial development, because its preparation does not involve the use of expensive or exotic compounds. Furthermore, even at the highest prepared concentration, high stability over time was observed. As a proof of concept, one sample with dimensions 109 mm ∅×114 mm height (≈1 L) was prepared

Neutron/gamma pulse shape discrimination in plastic scintillators: Preparation and characterization of various compositions

Energy Technology Data Exchange (ETDEWEB)

Blanc, Pauline [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (CNRS UMR 8531), École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan cedex (France); Hamel, Matthieu, E-mail: matthieu.hamel@cea.fr [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Dehé-Pittance, Chrystèle; Rocha, Licinio [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France); Pansu, Robert B. [Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (CNRS UMR 8531), École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan cedex (France); Normand, Stéphane [CEA, LIST, Laboratoire Capteurs et Architectures Électroniques, F-91191 Gif-sur-Yvette (France)

2014-06-01

This work deals with the preparation and evaluation of plastic scintillators for neutron/gamma pulse shape discrimination (PSD). We succeeded in developing a plastic scintillator with good neutron/gamma discrimination properties in the range of what is already being commercialized. Several combinations of primary and secondary fluorophores were implemented in chemically modified polymers. These scintillators were fully characterized by fluorescence spectroscopy and under neutron irradiation. The materials proved to be stable for up to 5 years without any degradation of PSD properties. They were then classified in terms of their PSD capabilities and light yield. Our best candidate, 28.6 wt% of primary fluorophore with a small amount of secondary fluorophore, shows promising PSD results and is particularly suited to industrial development, because its preparation does not involve the use of expensive or exotic compounds. Furthermore, even at the highest prepared concentration, high stability over time was observed. As a proof of concept, one sample with dimensions 109 mm ∅×114 mm height (≈1 L) was prepared.

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker [Mainz Univ. (Germany). Inst. fuer Kernchemie; Omtvedt, Jon-Petter [Oslo Univ. (Norway). Dept. of Chemistry; Skarnemark, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

2015-05-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s{sup -1} (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Statistical and Machine-Learning Classifier Framework to Improve Pulse Shape Discrimination System Design

Energy Technology Data Exchange (ETDEWEB)

Wurtz, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kaplan, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-10-28

Pulse shape discrimination (PSD) is a variety of statistical classifier. Fully-­realized statistical classifiers rely on a comprehensive set of tools for designing, building, and implementing. PSD advances rely on improvements to the implemented algorithm. PSD advances can be improved by using conventional statistical classifier or machine learning methods. This paper provides the reader with a glossary of classifier-­building elements and their functions in a fully-­designed and operational classifier framework that can be used to discover opportunities for improving PSD classifier projects. This paper recommends reporting the PSD classifier’s receiver operating characteristic (ROC) curve and its behavior at a gamma rejection rate (GRR) relevant for realistic applications.

Human perception of shape from touch

NARCIS (Netherlands)

Kappers, Astrid M L

2011-01-01

In this paper, I focus on the role of active touch in three aspects of shape perception and discrimination studies. First an overview is given of curvature discrimination experiments. The most prominent result is that first-order stimulus information (that is, the difference in attitude or slope

Background suppression by pulse shape discrimination in the CALIFA calorimeter

Energy Technology Data Exchange (ETDEWEB)

Heiss, Benjamin; Gernhaeuser, Roman; Klenze, Philipp; Remmels, Patrick; Winkel, Max [Technische Universtaet Muenchen (Germany); Collaboration: R3B-Collaboration

2016-07-01

The 4π-calorimeter CALIFA is one of the major detectors of the R{sup 3}B-experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) in Darmstadt. This calorimeter with 2464 CsI(Tl) crystals and 96 Phoswich detectors (LaBr{sub 3}(Ce) and LaCl{sub 3}(Ce)) plays a major role in the realization of kinematically complete measurements. General demands on CALIFA are a high efficiency, good energy resolution of about 5 % at 1 MeV γ energies and a large dynamic range, allowing a simultaneous measurement of γ-rays at E > 100 keV and scattered protons up to E < 700 MeV. Due to the very high energies of the light charged particles at the relativistic beam energies, especially in the forward direction of CALIFA, a significant fraction triggers nuclear reactions in the detector material. This talk presents the methods of the background suppression by pulse shape discrimination based on an experiment with protons at kinetic energies up to E = 480 MeV at the TRIUMF Laboratory in Vancouver, Canada.

A simple pulse shape discrimination technique applied to a silicon strip detector

International Nuclear Information System (INIS)

Figuera, P.; Lu, J.; Amorini, F.; Cardella, G.; DiPietro, A.; Papa, M.; Musumarra, A.; Pappalardo, G.; Rizzo, F.; Tudisco, S.

2001-01-01

Full text: Since the early sixties, it has been known that the shape of signals from solid state detectors can be used for particle identification. Recently, this idea has been revised in a group of papers where it has been shown that the shape of current signals from solid state detectors is mainly governed by the combination of plasma erosion time and charge carrier collection time effects. We will present the results of a systematic study on a pulse shape identification method which, contrary to the techniques proposed, is based on the use of the same electronic chain normally used in the conventional time of flight technique. The method is based on the use of charge preamplifiers, low polarization voltages (i.e. just above full depletion ones), rear side injection of the incident particles, and on a proper setting of the constant fraction discriminators which enhances the dependence of the timing output on the rise time of the input signals (which depends on the charge and energy of the incident ions). The method has been applied to an annular Si strip detector with an inner radius of about 16 mm and an outer radius of about 88 mm. The detector, manufactured by Eurisys Measures (Type Ips.73.74.300.N9), is 300 microns thick and consists of 8 independent sectors each divided into 9 circular strips. On beam tests have been performed at the cyclotron of the Laboratori Nazionali del Sud in Catania using a 25.7 MeV/nucleon 58 Ni beam impinging on a 51 V and 45 Sc composite target. Excellent charge identification from H up to the Ni projectile has been observed and typical charge identification thresholds are: ∼ 1.7 MeV/nucleon for Z ≅ 6, ∼ 3.0 MeV/nucleon for Z ≅ 11, and ∼ 5.5 MeV/nucleon for Z ≅ 20. Isotope identification up to A ≅ 13 has been observed with an energy threshold of about 6 MeV/nucleon. The identification quality has been studied as a function of the constant fraction settings. The method has been applied to all the 72 independent strips

Studies in genetic discrimination. Final progress report

Energy Technology Data Exchange (ETDEWEB)

1994-06-01

We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

Pulse-shape discrimination techniques for the COBRA double beta-decay experiment at LNGS

Science.gov (United States)

Zatschler, S.; COBRA Collaboration

2017-09-01

In modern elementary particle physics several questions arise from the fact that neutrino oscillation experiments have found neutrinos to be massive. Among them is the so far unknown nature of neutrinos: either they act as so-called Majorana particles, where one cannot distinguish between particle and antiparticle, or they are Dirac particles like all the other fermions in the Standard Model. The study of neutrinoless double beta-decay (0νββ-decay), where the lepton number conservation is violated by two units, could answer the question regarding the underlying nature of neutrinos and might also shed light on the mechanism responsible for the mass generation. So far there is no experimental evidence for the existence of 0νββ-decay, hence, existing experiments have to be improved and novel techniques should be explored. One of the next-generation experiments dedicated to the search for this ultra-rare decay is the COBRA experiment. This article gives an overview of techniques to identify and reject background based on pulse-shape discrimination.

Measurement of radionuclides using ion chromatography and flow-cell scintillation counting with pulse shape discrimination

International Nuclear Information System (INIS)

DeVol, T.A.; Fjeld, R.A.

1995-01-01

A project has been initiated at Clemson Univ. to develop a HPLC/flow- cell system for analysis of non-gamma emitting radionuclides in environmental samples; an important component is development of a low background flow-cell detector that counts alpha and beta particles separately through pulse shape discrimination. Objective of the work presented here is to provide preliminary results of an evaluation of the following scintillators: CaF 2 :Eu, scintillating glass, and BaF 2 . Slightly acidic aqueous solutions of the alpha emitter 233 U and the beta emitter 45 Ca were used. Detection efficiencies and minimum detectable activities were determined

Face adaptation improves gender discrimination.

Science.gov (United States)

Yang, Hua; Shen, Jianhong; Chen, Juan; Fang, Fang

2011-01-01

Adaptation to a visual pattern can alter the sensitivities of neuronal populations encoding the pattern. However, the functional roles of adaptation, especially in high-level vision, are still equivocal. In the present study, we performed three experiments to investigate if face gender adaptation could affect gender discrimination. Experiments 1 and 2 revealed that adapting to a male/female face could selectively enhance discrimination for male/female faces. Experiment 3 showed that the discrimination enhancement induced by face adaptation could transfer across a substantial change in three-dimensional face viewpoint. These results provide further evidence suggesting that, similar to low-level vision, adaptation in high-level vision could calibrate the visual system to current inputs of complex shapes (i.e. face) and improve discrimination at the adapted characteristic. Copyright © 2010 Elsevier Ltd. All rights reserved.

Doped luminescent materials and particle discrimination using same

Science.gov (United States)

Doty, F. Patrick; Allendorf, Mark D; Feng, Patrick L

2014-10-07

Doped luminescent materials are provided for converting excited triplet states to radiative hybrid states. The doped materials may be used to conduct pulse shape discrimination (PSD) using luminescence generated by harvested excited triplet states. The doped materials may also be used to detect particles using spectral shape discrimination (SSD).

A simple neutron-gamma discriminating system

International Nuclear Information System (INIS)

Liu Zhongming; Xing Shilin; Wang Zhongmin

1986-01-01

A simple neutron-gamma discriminating system is described. A detector and a pulse shape discriminator are suitable for the neutron-gamma discriminating system. The influence of the constant fraction discriminator threshold energy on the neutron-gamma resolution properties is shown. The neutron-gamma timing distributions from an 241 Am-Be source, 2.5 MeV neutron beam and 14 MeV neutron beam are presented

Digital pulse shape discrimination between fast neutrons and gamma rays with para-terphenyl scintillator

Science.gov (United States)

Chepurnov, A. S.; Kirsanov, M. A.; Klenin, A. A.; Klimanov, S. G.; Kubankin, A. S.

2017-12-01

In the presented work, we investigated several digital methods of a discrimination signals from fast neutrons and gamma quanta. The experimental setup consists of a Pu-Be neutron source, a scintillation detector with an organic para-terphenyl monocrystal, and a digitizer (CAEN DT5730, 500 MS/s). Mixed waveform sequences were stored and then separated by pulse shape. Four methods were used for signals separation. Comparison of the traditional and the new methods of Figure of Merit (FOM) calculation is given. FOM = 1.5 was obtained in our setup for the minimum threshold value. A scintillation detector with a para-terphenyl crystal was used to measure neutron yield in the neutron generator with carbon nanotubes.

The Neutron-Gamma Pulse Shape Discrimination Method for Neutron Flux Detection in the ITER

International Nuclear Information System (INIS)

Xu Xiufeng; Li Shiping; Cao Hongrui; Yin Zejie; Yuan Guoliang; Yang Qingwei

2013-01-01

The neutron flux monitor (NFM), as a significant diagnostic system in the International Thermonuclear Experimental Reactor (ITER), will play an important role in the readings of a series of key parameters in the fusion reaction process. As the core of the main electronic system of the NFM, the neutron-gamma pulse shape discrimination (n-γ PSD) can distinguish the neutron pulse from the gamma pulse and other disturbing pulses according to the thresholds of the rising time and the amplitude pre-installed on the board, the double timing point CFD method is used to get the rising time of the pulse. The n-γ PSD can provide an accurate neutron count. (magnetically confined plasma)

Fast differential pulse discriminator-counter

International Nuclear Information System (INIS)

Shelevoj, K.D.

1985-01-01

The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

Limitations of the pulse-shape technique for particle discrimination in planar Si detectors

International Nuclear Information System (INIS)

Pausch, G.; Seidel, W.; Lampert, M.O.; Rohr, P.

1996-11-01

Limitations of the pulse-shape discrimination (PSD) technique - a promising method to identify the charged particles stopped in planar Si-detectors - have been investigated. The particle resolution turned out to be basically determined by resistivity fluctuations in the bulk silicon which cause the charge-collection time to depend on the point of impact. Detector maps showing these fluctuations have been measured and are discussed. Furthermore we present a simple method to test the performance of detectors with respect to PSD. Another limitation of the PSD technique is the finite energy threshold for particle identification. This threshold is caused by an unexpected decrease of the total charge-collection time for ions with a short range, in spite of the fact that the particle tracks are located in a region of very low electric field. (orig.)

Otolith shape analysis as a tool for stock discrimination of the black scabbardfish, Aphanopus carbo Lowe, 1839 (Pisces: Trichiuridae, in Portuguese waters

Directory of Open Access Journals (Sweden)

Inês Farias

2009-12-01

Full Text Available The variability in otolith contour shape of black scabbardfish (Aphanopus carbo from Portuguese waters was analysed for stock discrimination purposes. The contour shape of otoliths from specimens caught off mainland Portugal, Madeira and Azores archipelagos was digitised and extracted according to the closed-form Fourier analysis technique. Mainland and Madeira specimens were compared through the adjustment of a MANOVA model to the normalised elliptic Fourier descriptor (NEFDs obtained for the otoliths of 200 females and 200 males sampled at each area. Significant differences were found between areas and between sexes; the interaction term was not statistically significant. The effect of the area also proved to be significant when samples from the three regions were considered. These results were further supported by the discriminant analysis of the individual NEFDs for which the correct classifications were 87.5-89% when they were considered by sex and total length for the mainland and Madeira, and 90.9-97.7%, when NEFDs from the three areas were compared by sex and fish length. Otolith contour shape was shown to be a possible tool for differentiating between black scabbardfish stocks in the NE Atlantic.

Investigation of depth-of-interaction by pulse shape discrimination in multicrystal detectors read out by avalanche photodiodes

International Nuclear Information System (INIS)

Saoudi, A.; Pepin, C.M.; Dion, F.; Bentourkia, M.; Lecomte, R.; Dautet, H.

1999-01-01

The measurement of depth of interaction (DOI) within detectors is necessary to improve resolution uniformity across the FOV of small diameter PET scanners. DOI encoding by pulse shape discrimination (PSD) has definite advantages as it requires only one readout per pixel and it allows DOI measurement of photoelectric and Compton events. The PSD time characteristics of various scintillators were studied with avalanche photodiodes (APD) and the identification capability was tested in multi-crystal assemblies with up to four scintillators. In the PSD time spectrum of an APD-GSO/LSO/BGO/CsI(Tl) assembly, four distinct time peaks at 45, 26, 88 and 150 ns relative to a fast test pulse, having resolution of 10.6, 5.2, 20 and 27 ns, can be easily separated. Whereas the number and position of scintillators in the multi-crystal assemblies affect detector performance, the ability to identify crystals is not compromised. Compton events have a significant effect on PSD accuracy, suggesting that photopeak energy gating should be used for better crystal identification. However, more sophisticated PSD techniques using parametric time-energy histograms can also improve crystal identification in cases where PSD time or energy discrimination alone is inadequate. These results confirm the feasibility of PSD DOI encoding with APD-based detectors for PET

A monolithic constant-fraction discriminator using distributed R-C delay-line shaping

International Nuclear Information System (INIS)

Simpson, M.L.; Young, G.R.; Xu, M.

1995-01-01

A monolithic, CMOS, constant-fraction discriminator (CFD) was fabricated in the Orbit Semiconductor, 1.2 μ N-well process. This circuit uses an on-chip, distributed, R-C delay-line to realize the constant-fraction shaping. The delay-line is constructed from a narrow, 500-μ serpentine layer of polysilicon above a wide, grounded, second layer of polysilicon. This R-C delay-line generates about 1.1 ns of delay for 5 ns risetime signals with a slope degradation of only ≅ 15% and an amplitude reduction of about 6.1%. The CFD also features an automatic walk adjustment. The entire circuit, including the delay line, has a 200 μ pitch and is 950 μ long. The walk for a 5 ns risetime signal was measured as ± 100 ps over the 100:1 dynamic range from -15 mV to -1.5 mV. to -1.5 V. The CFD consumes 15 mW

Place of birth effects on self-reported discrimination: Variations by type of discrimination.

Science.gov (United States)

Brondolo, Elizabeth; Rahim, Reanne; Grimaldi, Stephanie; Ashraf, Amina; Bui, Nini; Schwartz, Joseph

2015-11-01

Researchers have suggested that perceptions of discrimination may vary depending on place of birth and the length of time spent living in the U.S., variables related to acculturation. However, the existing literature provides a mixed picture, with data suggesting that the effects of acculturation on perceptions of discrimination vary by race and other sociodemographic factors. This study evaluated the role of place of birth (POB: defined as U.S.-born vs. foreign-born), age at immigration, and length of residence in the U.S. on self-reported discrimination in a sample of urban-dwelling Asian and Black adults (n= 1454). Analyses examined POB effects on different types of discrimination including race-related stigmatization, exclusion, threat, and workplace discrimination. Sociodemographic variables (including age, gender, employment status and education level) were tested as potential moderators of the relationship between POB and discrimination. The results revealed a significant main effect for POB on discrimination, with U.S.-born individuals reporting significantly more discrimination than foreign-born individuals, although the effect was reduced when sociodemographic variables were controlled. Across the sample, POB effects were seen only for race-related stigmatization and exclusion, not for threat and workplace discrimination. With the exception of limited effects for gender, sociodemographic variables did not moderate these effects. Younger age at immigration and greater years of residence in the U.S. were also positively associated with higher levels of perceived discrimination. These findings suggest increasing acculturation may shape the experience and perception of racial and ethnic discrimination.

Place of birth effects on self-reported discrimination: Variations by type of discrimination

Science.gov (United States)

Brondolo, Elizabeth; Rahim, Reanne; Grimaldi, Stephanie; Ashraf, Amina; Bui, Nini; Schwartz, Joseph

2016-01-01

Researchers have suggested that perceptions of discrimination may vary depending on place of birth and the length of time spent living in the U.S., variables related to acculturation. However, the existing literature provides a mixed picture, with data suggesting that the effects of acculturation on perceptions of discrimination vary by race and other sociodemographic factors. This study evaluated the role of place of birth (POB: defined as U.S.-born vs. foreign-born), age at immigration, and length of residence in the U.S. on self-reported discrimination in a sample of urban-dwelling Asian and Black adults (n= 1454). Analyses examined POB effects on different types of discrimination including race-related stigmatization, exclusion, threat, and workplace discrimination. Sociodemographic variables (including age, gender, employment status and education level) were tested as potential moderators of the relationship between POB and discrimination. The results revealed a significant main effect for POB on discrimination, with U.S.-born individuals reporting significantly more discrimination than foreign-born individuals, although the effect was reduced when sociodemographic variables were controlled. Across the sample, POB effects were seen only for race-related stigmatization and exclusion, not for threat and workplace discrimination. With the exception of limited effects for gender, sociodemographic variables did not moderate these effects. Younger age at immigration and greater years of residence in the U.S. were also positively associated with higher levels of perceived discrimination. These findings suggest increasing acculturation may shape the experience and perception of racial and ethnic discrimination. PMID:27647943

Optimal design of waveform digitisers for both energy resolution and pulse shape discrimination

Science.gov (United States)

Cang, Jirong; Xue, Tao; Zeng, Ming; Zeng, Zhi; Ma, Hao; Cheng, Jianping; Liu, Yinong

2018-04-01

Fast digitisers and digital pulse processing have been widely used for spectral application and pulse shape discrimination (PSD) owing to their advantages in terms of compactness, higher trigger rates, offline analysis, etc. Meanwhile, the noise of readout electronics is usually trivial for organic, plastic, or liquid scintillator with PSD ability because of their poor intrinsic energy resolution. However, LaBr3(Ce) has been widely used for its excellent energy resolution and has been proven to have PSD ability for alpha/gamma particles. Therefore, designing a digital acquisition system for such scintillators as LaBr3(Ce) with both optimal energy resolution and promising PSD ability is worthwhile. Several experimental research studies about the choice of digitiser properties for liquid scintillators have already been conducted in terms of the sampling rate and vertical resolution. Quantitative analysis on the influence of waveform digitisers, that is, fast amplifier (optional), sampling rates, and vertical resolution, on both applications is still lacking. The present paper provides quantitative analysis of these factors and, hence, general rules about the optimal design of digitisers for both energy resolution and PSD application according to the noise analysis of time-variant gated charge integration.

Neutron calibration facility with an Am-Be source for pulse shape discrimination measurement of CsI(Tl) crystals

International Nuclear Information System (INIS)

Lee, H.S.; Bhang, H.; Choi, J.H.; Choi, S.; Joo, H.W.; Kim, G.B.; Kim, K.W.; Kim, S.C.; Kim, S.K.; Lee, J.H.; Lee, J.K.; Myung, S.S.; Hahn, I.S.; Jeon, E.J.; Kang, W.G.; Kim, Y.D.; Kim, Y.H.; Li, J.; Kim, H.J.; Leonard, D.S.

2014-01-01

We constructed a neutron calibration facility based on a 300-mCi Am-Be source in conjunction with a search for weakly interacting massive particle candidates for dark matter. The facility is used to study the response of CsI(Tl) crystals to nuclear recoils induced by neutrons from the Am-Be source and comparing them with the response to electron recoils produced by Compton scattering of 662-keV γ-rays from a 137 Cs source. The measured results on pulse shape discrimination (PSD) between nuclear- and electron-recoil events are quantified in terms of quality factors. A comparison with our previous result from a neutron generator demonstrate the feasibility of performing calibrations of PSD measurements using neutrons from a Am-Be source

Discrimination and sleep: a systematic review.

Science.gov (United States)

Slopen, Natalie; Lewis, Tené T; Williams, David R

2016-02-01

An increasing body of literature indicates that discrimination has a negative impact on health; poor sleep may be an underlying mechanism. The primary objective of this review was to examine existing studies on the relationship between discrimination and sleep to clarify (a) the potential role of discrimination in shaping population patterns of sleep and sleep disparities, and (b) the research needed to develop interventions at individual and institutional levels. We identified articles from English-language publications in PubMed and EBSCO databases from inception through July 2014. We employed a broad definition of discrimination to include any form of unfair treatment and all self-reported and objectively assessed sleep outcomes, including duration, difficulties, and sleep architecture. Seventeen studies were identified: four prospective, 12 cross-sectional, and one that utilized a daily-diary design. Fifteen of the 17 studies evaluated interpersonal discrimination as the exposure and the majority of studies included self-reported sleep as the outcome. Only four studies incorporated objective sleep assessments. All 17 studies identified at least one association between discrimination and a measure of poorer sleep, although studies with more detailed consideration of either discrimination or sleep architecture revealed some inconsistencies. Taken together, existing studies demonstrate consistent evidence that discrimination is associated with poorer sleep outcomes. This evidence base can be strengthened with additional prospective studies that incorporate objectively measured aspects of sleep. We outline important extensions for this field of inquiry that can inform the development of interventions to improve sleep outcomes, and consequently promote well-being and reduce health inequities across the life course. Copyright © 2015 Elsevier B.V. All rights reserved.

Pulse discrimination of scintillator detector with artificial neural network

International Nuclear Information System (INIS)

Chen Man; Cai Yuerong; Yang Chaowen

2006-01-01

The features of signal for scintillator detectors are analyzed. According to the difference in the fraction of slow and fast scintillation for different particles, three intrinsic parameters (signal amplitude, integration of signal during rinsing, integration of frequency spectrum of signals in middle frequencies) of signals are defined. The artificial neural network method for pulse discrimination of scintillator detector is studied. The signals with different shapes under real condition are simulated with computer, and discriminated by the method. Results of discrimination are gotten and discussed. (authors)

Comparative study of neutron and gamma-ray pulse shape discrimination of anthracene, stilbene, and p-terphenyl

International Nuclear Information System (INIS)

Yanagida, Takayuki; Watanabe, Kenichi; Fujimoto, Yutaka

2015-01-01

Solid state organic scintillators, such as anthracene, stilbene, and p-terphenyl were investigated on their basic scintillation properties and neutron–gamma discrimination capabilities. Scintillation wavelengths under X-ray irradiation of anthracene, stilbene, and p-terphenyl were 445–525, 400–500, and 350–450 nm, respectively. Scintillation light yields of anthracene, stilbene, and p-terphenyl under 137 Cs gamma-ray irradiation were 20100, 16000, and 19400 ph/MeV, respectively. Neutron and gamma-ray events discrimination capabilities were examined and anthracene exhibited the best figure of merit among three organic scintillators

Comparative study of neutron and gamma-ray pulse shape discrimination of anthracene, stilbene, and p-terphenyl

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Takayuki, E-mail: yanagida@lsse.kyutech.ac.jp [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0196 (Japan); Watanabe, Kenichi [Nagoya University, Furocho, Chikusa, Nagoya 464-8603 (Japan); Fujimoto, Yutaka [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0196 (Japan)

2015-06-01

Solid state organic scintillators, such as anthracene, stilbene, and p-terphenyl were investigated on their basic scintillation properties and neutron–gamma discrimination capabilities. Scintillation wavelengths under X-ray irradiation of anthracene, stilbene, and p-terphenyl were 445–525, 400–500, and 350–450 nm, respectively. Scintillation light yields of anthracene, stilbene, and p-terphenyl under {sup 137}Cs gamma-ray irradiation were 20100, 16000, and 19400 ph/MeV, respectively. Neutron and gamma-ray events discrimination capabilities were examined and anthracene exhibited the best figure of merit among three organic scintillators.

Culture shapes 7-month-olds' perceptual strategies in discriminating facial expressions of emotion.

Science.gov (United States)

Geangu, Elena; Ichikawa, Hiroko; Lao, Junpeng; Kanazawa, So; Yamaguchi, Masami K; Caldara, Roberto; Turati, Chiara

2016-07-25

Emotional facial expressions are thought to have evolved because they play a crucial role in species' survival. From infancy, humans develop dedicated neural circuits [1] to exhibit and recognize a variety of facial expressions [2]. But there is increasing evidence that culture specifies when and how certain emotions can be expressed - social norms - and that the mature perceptual mechanisms used to transmit and decode the visual information from emotional signals differ between Western and Eastern adults [3-5]. Specifically, the mouth is more informative for transmitting emotional signals in Westerners and the eye region for Easterners [4], generating culture-specific fixation biases towards these features [5]. During development, it is recognized that cultural differences can be observed at the level of emotional reactivity and regulation [6], and to the culturally dominant modes of attention [7]. Nonetheless, to our knowledge no study has explored whether culture shapes the processing of facial emotional signals early in development. The data we report here show that, by 7 months, infants from both cultures visually discriminate facial expressions of emotion by relying on culturally distinct fixation strategies, resembling those used by the adults from the environment in which they develop [5]. Copyright © 2016 Elsevier Ltd. All rights reserved.

Feelings: what questions best discriminate women with and without eating disorders?

Science.gov (United States)

Abraham, S F; von Lojewski, A; Anderson, G; Clarke, S; Russell, J

2009-03-01

This study explored feelings that discriminate between eating disorder and community groups of women. Responses to 25 questions about body image (9), eating (8) self-esteem (3) general psychology (5) were collected in 2002-2003 (N=268) and 2005-2006 (N=472). Wilk's lambda was used to test discrimination. The most discriminating psychological questions were: 'feeling unhappy and unable to cope as well as usual', 'unease attending social functions', 'fearing loss of control over emotions'; and for eating questions were: 'feeling uneasy if other people saw you eating', 'feeling preoccupied with food/eating', 'fearing loss of control over eating'. For body image only 'feeling preoccupied with body weight/shape' and 'fearing loss of control over your body' discriminated. Questions relating to weight and shape for self-esteem ('feeling fat', 'fearing weight gain' and 'wanting to lose weight') discriminated poorly. Results for both cohorts were consistent. Preoccupation with thoughts of eating or body image and fear of loss of control of these would be useful additions to eating disorders criteria. Psychological impairment should also be present.

EJ-309 pulse shape discrimination performance with a high gamma-ray-to-neutron ratio and low threshold

Energy Technology Data Exchange (ETDEWEB)

Kaplan, A.C., E-mail: Alexis.C.Kaplan@gmail.com [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48104 (United States); Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Flaska, M.; Enqvist, A.; Dolan, J.L.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48104 (United States)

2013-11-21

Measuring neutrons in the presence of high gamma-ray fluence is a challenge with multi-particle detectors. Organic liquid scintillators such as the EJ-309 are capable of accurate pulse-shape discrimination (PSD) but the chance for particle misclassification is not negligible for some applications. By varying the distance from an EJ-309 scintillator to a strong-gamma-ray source and keeping a weak-neutron source at a fixed position, various gamma-to-neutron ratios can be measured and PSD performance can be quantified. Comparing neutron pulse-height distributions allows for pulse-height specific PSD evaluation, and quantification and visualization of deviation from {sup 252}Cf alone. Even with the addition of the misclassified gamma-rays, the PSD is effective in separating particles so that neutron count rate can be predicted with less than 10% error up to a gamma-to-neutron ratio of almost 650. For applications which can afford a reduction in neutron detection efficiency, PSD can be sufficiently effective in discriminating particles to measure a weak neutron source in a high gamma-ray background. -- Highlights: •We measure neutrons in a high photon background with EJ-309 liquid scintillators. •A low threshold is used to test the limits of particle discrimination. •A weak neutron signal is detectable with a gamma/neutron ratio as high as 770. •Photon pileup most commonly adds to error in classification of neutrons. •Neutron count rates are within 10% of expected rate under high gamma background.

EJ-309 pulse shape discrimination performance with a high gamma-ray-to-neutron ratio and low threshold

International Nuclear Information System (INIS)

Kaplan, A.C.; Flaska, M.; Enqvist, A.; Dolan, J.L.; Pozzi, S.A.

2013-01-01

Measuring neutrons in the presence of high gamma-ray fluence is a challenge with multi-particle detectors. Organic liquid scintillators such as the EJ-309 are capable of accurate pulse-shape discrimination (PSD) but the chance for particle misclassification is not negligible for some applications. By varying the distance from an EJ-309 scintillator to a strong-gamma-ray source and keeping a weak-neutron source at a fixed position, various gamma-to-neutron ratios can be measured and PSD performance can be quantified. Comparing neutron pulse-height distributions allows for pulse-height specific PSD evaluation, and quantification and visualization of deviation from 252 Cf alone. Even with the addition of the misclassified gamma-rays, the PSD is effective in separating particles so that neutron count rate can be predicted with less than 10% error up to a gamma-to-neutron ratio of almost 650. For applications which can afford a reduction in neutron detection efficiency, PSD can be sufficiently effective in discriminating particles to measure a weak neutron source in a high gamma-ray background. -- Highlights: •We measure neutrons in a high photon background with EJ-309 liquid scintillators. •A low threshold is used to test the limits of particle discrimination. •A weak neutron signal is detectable with a gamma/neutron ratio as high as 770. •Photon pileup most commonly adds to error in classification of neutrons. •Neutron count rates are within 10% of expected rate under high gamma background

Bilateral lesions of nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS) selectively impair figure-ground discrimination in pigeons.

Science.gov (United States)

Scully, Erin N; Acerbo, Martin J; Lazareva, Olga F

2014-01-01

Earlier, we reported that nucleus rotundus (Rt) together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), had significantly higher activity in pigeons performing figure-ground discrimination than in the control group that did not perform any visual discriminations. In contrast, color discrimination produced significantly higher activity than control in the Rt but not in the SP/IPS. Finally, shape discrimination produced significantly lower activity than control in both the Rt and the SP/IPS. In this study, we trained pigeons to simultaneously perform three visual discriminations (figure-ground, color, and shape) using the same stimulus displays. When birds learned to perform all three tasks concurrently at high levels of accuracy, we conducted bilateral chemical lesions of the SP/IPS. After a period of recovery, the birds were retrained on the same tasks to evaluate the effect of lesions on maintenance of these discriminations. We found that the lesions of the SP/IPS had no effect on color or shape discrimination and that they significantly impaired figure-ground discrimination. Together with our earlier data, these results suggest that the nucleus Rt and the SP/IPS are the key structures involved in figure-ground discrimination. These results also imply that thalamic processing is critical for figure-ground segregation in avian brain.

Proportional counters for measuring plutonium-239 'in vivo' - The choice of counting gas and the use of pulse shape discrimination techniques

International Nuclear Information System (INIS)

Pike, R.A.; Ramsden, D.

1969-08-01

The system for determining insoluble plutonium 'in vivo', now in routine use at A.E.E-. Winfrith, has a limit of detection of the order of 4 nCi plutonium - 239. The method of reducing background by using pulse shape discrimination techniques whilst retaining a high detection efficiency is described. The choice of a counting gas mixture to obtain optimum performance is discussed as are the techniques of gas handling. (author)

Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal

International Nuclear Information System (INIS)

Lee, H.S.; Adhikari, G.; Adhikari, P.; Choi, S.; Hahn, I.S.

2015-01-01

We report on the response of a high light-output NaI(Tl) crystal to nuclear recoils induced by neutrons from an Am-Be source and compare the results with the response to electron recoils produced by Compton-scattered 662 keV γ-rays from a 137 Cs source. The measured pulse-shape discrimination (PSD) power of the NaI(Tl) crystal is found to be significantly improved because of the high light output of the NaI(Tl) detector. We quantify the PSD power with a quality factor and estimate the sensitivity to the interaction rate for weakly interacting massive particles (WIMPs) with nucleons, and the result is compared with the annual modulation amplitude observed by the DAMA/LIBRA experiment. The sensitivity to spin-independent WIMP-nucleon interactions based on 100 kg⋅year of data from NaI detectors is estimated with simulated experiments, using the standard halo model.

Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal

Energy Technology Data Exchange (ETDEWEB)

Lee, H.S. [Department of Physics, Ewha Womans University,Seoul 120-750 (Korea, Republic of); Adhikari, G.; Adhikari, P. [Department of Physics, Sejong University,Seoul 143-747 (Korea, Republic of); Choi, S. [Department of Physics and Astronomy, Seoul National University,Seoul 151-747 (Korea, Republic of); Hahn, I.S. [Department of Science Education, Ewha Womans University,Seoul 120-750 (Korea, Republic of)

2015-08-18

We report on the response of a high light-output NaI(Tl) crystal to nuclear recoils induced by neutrons from an Am-Be source and compare the results with the response to electron recoils produced by Compton-scattered 662 keV γ-rays from a {sup 137}Cs source. The measured pulse-shape discrimination (PSD) power of the NaI(Tl) crystal is found to be significantly improved because of the high light output of the NaI(Tl) detector. We quantify the PSD power with a quality factor and estimate the sensitivity to the interaction rate for weakly interacting massive particles (WIMPs) with nucleons, and the result is compared with the annual modulation amplitude observed by the DAMA/LIBRA experiment. The sensitivity to spin-independent WIMP-nucleon interactions based on 100 kg⋅year of data from NaI detectors is estimated with simulated experiments, using the standard halo model.

Evidence of across-channel processing for spectral-ripple discrimination in cochlear implant listeners.

Science.gov (United States)

Won, Jong Ho; Jones, Gary L; Drennan, Ward R; Jameyson, Elyse M; Rubinstein, Jay T

2011-10-01

Spectral-ripple discrimination has been used widely for psychoacoustical studies in normal-hearing, hearing-impaired, and cochlear implant listeners. The present study investigated the perceptual mechanism for spectral-ripple discrimination in cochlear implant listeners. The main goal of this study was to determine whether cochlear implant listeners use a local intensity cue or global spectral shape for spectral-ripple discrimination. The effect of electrode separation on spectral-ripple discrimination was also evaluated. Results showed that it is highly unlikely that cochlear implant listeners depend on a local intensity cue for spectral-ripple discrimination. A phenomenological model of spectral-ripple discrimination, as an "ideal observer," showed that a perceptual mechanism based on discrimination of a single intensity difference cannot account for performance of cochlear implant listeners. Spectral modulation depth and electrode separation were found to significantly affect spectral-ripple discrimination. The evidence supports the hypothesis that spectral-ripple discrimination involves integrating information from multiple channels. © 2011 Acoustical Society of America

Learning temporal context shapes prestimulus alpha oscillations and improves visual discrimination performance.

Science.gov (United States)

Toosi, Tahereh; K Tousi, Ehsan; Esteky, Hossein

2017-08-01

Time is an inseparable component of every physical event that we perceive, yet it is not clear how the brain processes time or how the neuronal representation of time affects our perception of events. Here we asked subjects to perform a visual discrimination task while we changed the temporal context in which the stimuli were presented. We collected electroencephalography (EEG) signals in two temporal contexts. In predictable blocks stimuli were presented after a constant delay relative to a visual cue, and in unpredictable blocks stimuli were presented after variable delays relative to the visual cue. Four subsecond delays of 83, 150, 400, and 800 ms were used in the predictable and unpredictable blocks. We observed that predictability modulated the power of prestimulus alpha oscillations in the parieto-occipital sites: alpha power increased in the 300-ms window before stimulus onset in the predictable blocks compared with the unpredictable blocks. This modulation only occurred in the longest delay period, 800 ms, in which predictability also improved the behavioral performance of the subjects. Moreover, learning the temporal context shaped the prestimulus alpha power: modulation of prestimulus alpha power grew during the predictable block and correlated with performance enhancement. These results suggest that the brain is able to learn the subsecond temporal context of stimuli and use this to enhance sensory processing. Furthermore, the neural correlate of this temporal prediction is reflected in the alpha oscillations. NEW & NOTEWORTHY It is not well understood how the uncertainty in the timing of an external event affects its processing, particularly at subsecond scales. Here we demonstrate how a predictable timing scheme improves visual processing. We found that learning the predictable scheme gradually shaped the prestimulus alpha power. These findings indicate that the human brain is able to extract implicit subsecond patterns in the temporal context of

Fast neutron tomography with real-time pulse-shape discrimination in organic scintillation detectors

Energy Technology Data Exchange (ETDEWEB)

Joyce, Malcolm J., E-mail: m.joyce@lancaster.ac.uk [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom); Agar, Stewart [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom); Aspinall, Michael D. [Hybrid Instruments Ltd., Gordon Manley Building, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YW (United Kingdom); Beaumont, Jonathan S.; Colley, Edmund; Colling, Miriam; Dykes, Joseph; Kardasopoulos, Phoevos; Mitton, Katie [Department of Engineering, Lancaster University, Lancaster, Lancashire LA1 4YW (United Kingdom)

2016-10-21

A fast neutron tomography system based on the use of real-time pulse-shape discrimination in 7 organic liquid scintillation detectors is described. The system has been tested with a californium-252 source of dose rate 163 μSv/h at 1 m and neutron emission rate of 1.5×10{sup 7} per second into 4π and a maximum acquisition time of 2 h, to characterize two 100×100×100 mm{sup 3} concrete samples. The first of these was a solid sample and the second has a vertical, cylindrical void. The experimental data, supported by simulations with both Monte Carlo methods and MATLAB®, indicate that the presence of the internal cylindrical void, corners and inhomogeneities in the samples can be discerned. The potential for fast neutron assay of this type with the capability to probe hydrogenous features in large low-Z samples is discussed. Neutron tomography of bulk porous samples is achieved that combines effective penetration not possible with thermal neutrons in the absence of beam hardening.

Novel discrimination parameters for neutron-gamma discrimination with liquid scintillation detectors using wavelet transform

International Nuclear Information System (INIS)

Singh, H.; Singh, S.

2015-01-01

It has been observed that the discrimination performance of the wavelet transform method strongly depends on definition of discrimination parameters. These parameters are usually obtained from a combination of scaling functions at different scales, which represents the energy density of the wavelet coefficients. In this paper, the discrete wavelet transform (DWT) at minimum possible values of scale was investigated. Novel pulse shape discrimination parameters have been proposed for neutron and gamma discrimination in a mixed radiation field and tested with modeled pulses. The performance of these parameters was also validated in terms of quality of discrimination using experimental data of mixed events from an AmBe source collected with BC501 liquid scintillation detector. The quality of discrimination was evaluated by calculating a figure of merit (FOM) with all parameters under same experimental and simulation conditions. The FOM obtained with the proposed novel parameters was also compared with the charge comparison method. The proposed parameters exhibit better FOM as compared to the charge comparison method when high levels of noise are present in the data

An event-related brain potential study of visual selective attention to conjunctions of color and shape.

Science.gov (United States)

Smid, H G; Jakob, A; Heinze, H J

1999-03-01

What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other conjunctions of these attributes in three discriminability conditions. Attending to color and shape produced three ERP effects: frontal selection positivity (FSP), central negativity (N2b), and posterior selection negativity (SN). The results suggested that the processes underlying SN and N2b perform independent within-dimension selections, whereas the process underlying the FSP performs hierarchical between-dimension selections. At posterior electrodes, manipulation of discriminability changed the ERPs to the relevant but not to the irrelevant stimuli, suggesting that the SN does not concern the selection process itself but rather a cognitive process initiated after selection is finished. Other findings suggested that selection of multiple visual attributes occurs in parallel.

Evidence of across-channel processing for spectral-ripple discrimination in cochlear implant listeners a

Science.gov (United States)

Ho Won, Jong; Jones, Gary L.; Drennan, Ward R.; Jameyson, Elyse M.; Rubinstein, Jay T.

2011-01-01

Spectral-ripple discrimination has been used widely for psychoacoustical studies in normal-hearing, hearing-impaired, and cochlear implant listeners. The present study investigated the perceptual mechanism for spectral-ripple discrimination in cochlear implant listeners. The main goal of this study was to determine whether cochlear implant listeners use a local intensity cue or global spectral shape for spectral-ripple discrimination. The effect of electrode separation on spectral-ripple discrimination was also evaluated. Results showed that it is highly unlikely that cochlear implant listeners depend on a local intensity cue for spectral-ripple discrimination. A phenomenological model of spectral-ripple discrimination, as an “ideal observer,” showed that a perceptual mechanism based on discrimination of a single intensity difference cannot account for performance of cochlear implant listeners. Spectral modulation depth and electrode separation were found to significantly affect spectral-ripple discrimination. The evidence supports the hypothesis that spectral-ripple discrimination involves integrating information from multiple channels. PMID:21973363

Improvement of SOI microdosimeter performance using pulse shape discrimination techniques

International Nuclear Information System (INIS)

Cornelius, I.

2002-01-01

Full text: Microdosimetry is used to study the radiobiological properties of densely ionising radiations encountered in hadron therapy and space environments by measuring energy deposition in microscopic volumes. The creation of a solid state microdosimeter to replace the traditional tissue equivalent proportional counter is a topic of ongoing research. The Centre for Medical Radiation Physics has been investigating a technique using microscopic arrays of reverse biased pn junctions to measure the linear energy transfer of ions. A prototype silicon-on-insulator (SOI) microdosimeter was developed and measurements were conducted at boron neutron capture therapy, proton therapy, and fast neutron therapy facilities. Previous studies have shown the current microdosimeter possesses a poorly defined sensitive volume, a consequence of charge collection events being measured for ion strikes outside the pn junction via the diffusion of charge carriers. As a result, the amount of charge collected by the microdosimeter following an ion strike has a strong dependence on the location of the strike on the device and the angle of incidence of the ion. The aim of this work was to investigate the use of pulse shape discrimination (PSD) techniques to preclude the acquisition of events resulting from ion strikes outside the depletion region of the pn junction. Experiments were carried out using the Heavy Ion Microprobe (HIMP) at the Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia. The HIMP was used to measure the charge collection time as a function of ion strike location on the microdosimeter array. As expected, the charge collection time was seen to increase monotonically as the distance of the ion strike from the junction increased. The charge collection time corresponding to ion strikes within the junction was determined. Through use of suitable electronics it was possible to gate the charge collection signal based on simultaneous measurements of

Extrastriate cortical areas activated during visual discrimination in man

DEFF Research Database (Denmark)

Roland, PE

1981-01-01

The regional cerebral blood flow (rCBF) was measured in 254 different regions of the human extrastriate cerebral cortex during rest and during visual shape discrimination. Visual shape discrimination increased the rCBF markedly in the frontal eye fields, the upper part of the prefrontal cortex, t......, the lateral occipital cortex and the superior parietal cortex. Moderate increases of rCBF appeared in the inferotemporal cortex, the parietotemporo-occipital region and scattered in the lateral part of the prefrontal cortex....

Evaluation of granulated BGO, GSO:Ce, YAG:Ce, CaF2:Eu and ZnS:Ag for alpha/beta pulse shape discrimination in a flow-cell radiation detector

International Nuclear Information System (INIS)

DeVol, T.A.; Chotoo, S.B.; Fjeld, R.A.

1999-01-01

Granulated BGO, GSO:Ce, YAG:Ce, and CaF 2 :Eu; CaF 2 :Eu coated with a fluorescent polymer, and combinations of coated and uncoated CaF 2 :Eu with ZnS:Ag were evaluated for their ability to discriminate between alpha and beta particles in a flow-cell radiation detector. The evaluations were based on the analysis of pulse shape spectra. Various granulated scintillators were packed into flow cell detectors that were coils of 3.0 mm ODx1.5 mm ID fluorinated ethylene propylene Teflon[reg] tubing positioned between dual photomultiplier tubes for analysis. The best pulse shape discrimination was obtained for a combination of equal masses of uncoated CaF 2 :Eu (63-90 μm) and ZnS:Ag (10 μm), which had a 9% spillover. Additional research is needed to reduce the spillover

Intrapopulation variability shaping isotope discrimination and turnover: experimental evidence in arctic foxes.

Directory of Open Access Journals (Sweden)

Nicolas Lecomte

Full Text Available Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue composition has changed. We investigated simultaneously the effects of age, sex, and diet types on the variation of discrimination and half-life in nitrogen and carbon stable isotopes (δ¹⁵N and δ¹³C, respectively in five tissues (blood cells, plasma, muscle, liver, nail, and hair of a top predator, the arctic fox Vulpes lagopus.We fed 40 farmed foxes (equal numbers of adults and yearlings of both sexes with diet capturing the range of resources used by their wild counterparts. We found that, for a single species, six tissues, and three diet types, the range of discrimination values can be almost as large as what is known at the scale of the whole mammalian or avian class. Discrimination varied depending on sex, age, tissue, and diet types, ranging from 0.3‰ to 5.3‰ (mean  = 2.6‰ for δ¹⁵N and from 0.2‰ to 2.9‰ (mean  = 0.9‰ for δ¹³C. We also found an impact of population structure on δ¹⁵N half-life in blood cells. Varying across individuals, δ¹⁵N half-life in plasma (6 to 10 days was also shorter than for δ¹³C (14 to 22 days, though δ¹⁵N and δ¹³C half-lives are usually considered as equal.Overall, our multi-factorial experiment revealed that at least six levels of isotopic variations could co-occur in the same population. Our experimental analysis provides a framework for quantifying multiple sources of variation in isotopic discrimination and half-life that needs to be taken into account when designing and analysing ecological field studies.

Task-irrelevant emotion facilitates face discrimination learning.

Science.gov (United States)

Lorenzino, Martina; Caudek, Corrado

2015-03-01

We understand poorly how the ability to discriminate faces from one another is shaped by visual experience. The purpose of the present study is to determine whether face discrimination learning can be facilitated by facial emotions. To answer this question, we used a task-irrelevant perceptual learning paradigm because it closely mimics the learning processes that, in daily life, occur without a conscious intention to learn and without an attentional focus on specific facial features. We measured face discrimination thresholds before and after training. During the training phase (4 days), participants performed a contrast discrimination task on face images. They were not informed that we introduced (task-irrelevant) subtle variations in the face images from trial to trial. For the Identity group, the task-irrelevant features were variations along a morphing continuum of facial identity. For the Emotion group, the task-irrelevant features were variations along an emotional expression morphing continuum. The Control group did not undergo contrast discrimination learning and only performed the pre-training and post-training tests, with the same temporal gap between them as the other two groups. Results indicate that face discrimination improved, but only for the Emotion group. Participants in the Emotion group, moreover, showed face discrimination improvements also for stimulus variations along the facial identity dimension, even if these (task-irrelevant) stimulus features had not been presented during training. The present results highlight the importance of emotions for face discrimination learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Visual shape recognition in crayfish as revealed by habituation.

Directory of Open Access Journals (Sweden)

Cinzia Chiandetti

2017-08-01

Full Text Available To cope with the everyday challenges that they encounter in their evolutionary niche, crayfish are considered to rely mainly on chemical information or, alternatively, on tactile information, but not much on vision. Hence, research has focused on chemical communication, whereas crayfish visual abilities remain poorly understood and investigated. To fill in this gap, we tested whether crayfish (Procambarus clarkii can distinguish between two different visual shapes matched in terms of luminance. To this aim, we measured both the habituation response to a repeated presentation of a given shape, a downright Y, and the response recovery when a novel shape was presented. The novel shape could be either a Möbius or the same Y-shape but upright rotated. Our results demonstrate that, after habituation to the downright Y, crayfish showed a significantly higher response recovery to the Möbius as compared to the upright rotated Y. Hence, besides relying on chemo-haptic information, we found that crayfish can use sight alone to discriminate between different abstract geometrical shapes when macroscopically different. Failure to discriminate between the downright Y and its inversion or a generalization from the presence of a shape with three points creating a simple category, are both likely parsimonious explanations that should be investigated systematically in further studies. A future challenge will be understanding whether crayfish are capable of generalized shape recognition.

Investigation on n/γ discrimination methods for liquid scintillator detector

International Nuclear Information System (INIS)

Li Kuinian; Li Yang; Zhang Mei; Zhang Zhongbing; Li Binkang; Zhang Xiaodong; Liu Jun; Zhang Xianpeng

2014-01-01

To obtain the n/γ discrimination ability of different digital pulse shape discrimination methods, four methods (rising time method, charge comparison method, pulse gradient analysis and frequency gradient analysis) in americium-beryllium mixed radiation fields were demonstrated. The signals from EJ-301 and BC501A scintillator detectors were digitized using oscilloscope. A comparison was taken among the four discrimination methods. The discrimination results of the four methods in liquid scintillator detectors show that the rising time method is the best and it provides a good choice in real-time n/γ discrimination system. (authors)

Improvement in limit of detection in particle induced X-ray emission by means of rise time and pulse shape discrimination

Energy Technology Data Exchange (ETDEWEB)

Papp, Tibor E-mail: tibpapp@netscape.nettibpapp@yahoo.ca; Lakatos, Tamas; Nejedly, Zdenek; Campbell, John L

2002-04-01

A digital signal processor, based upon high-rate sampling of the preamplifier output, and equipped with rise time and pulse shape discrimination, has been tested in three situations. This processor provided significant improvement of particle induced X-ray emission and X-ray fluorescence detection limits over the state of the art analog processors, depending on the energy and intensity distribution of the X-ray spectra. Additionally it had a superior performance when measurements were performed in an environment of large electronic noise and in large nuclear background environment. It has also improved the reduction of several artifacts in X-ray spectra.

The relationship between cross-sectional shapes and FTIR profiles in synthetic wig fibers and their discriminating abilities - An evidential value perspective.

Science.gov (United States)

Joslin Yogi, Theresa A; Penrod, Michael; Holt, Melinda; Buzzini, Patrick

2018-02-01

Wig fragments or fibers may occasionally be recognized as potential physical evidence during criminal investigations. While analytical methods traditionally adopted for the examination of textile fibers are utilized for the characterizations and comparisons of wig specimens, it is essential to understand in deeper detail the valuable contribution of features of these non-routine evidentiary materials as well as the relationship of the gathered analytical data. This study explores the dependence between the microscopic features of cross-sectional shapes and the polymer type gathered by Fourier transform infrared (FTIR) spectroscopy. The discriminating power of the two methods of cross-sectioning and FTIR spectroscopy was also investigated. Forty-one synthetic wigs varying in both quality and price were collected: twenty-three brown, twelve blondes and six black samples. The collected samples were observed using light microscopy methods (bright field illumination and polarized light), before obtaining cross-sections using the Joliff method and analyze them using FTIR spectroscopy. The forty-one samples were divided into ten groups based on one or more of the ten types of cross-sectional shapes that were observed. The majority of encountered cross-sectional shapes were defined as horseshoe, dog bone and lobular. Infrared spectroscopy confirmed modacrylic to be the most prevalent fiber type. Blends of modacrylic and polyvinyl chloride fibers were also observed as well as polypropylene wig samples. The Goodman and Kruskal lambda statistical test was used and showed that the cross-sectional shape and infrared profile were related. From an evidentiary value perspective, this finding has implications when addressing questions about a common source between questioned wig specimens and a wig reference sample. Copyright © 2017 Elsevier B.V. All rights reserved.

A CMOS integrated timing discriminator circuit for fast scintillation counters

International Nuclear Information System (INIS)

Jochmann, M.W.

1998-01-01

Based on a zero-crossing discriminator using a CR differentiation network for pulse shaping, a new CMOS integrated timing discriminator circuit is proposed for fast (t r ≥ 2 ns) scintillation counters at the cooler synchrotron COSY-Juelich. By eliminating the input signal's amplitude information by means of an analog continuous-time divider, a normalized pulse shape at the zero-crossing point is gained over a wide dynamic input amplitude range. In combination with an arming comparator and a monostable multivibrator this yields in a highly precise timing discriminator circuit, that is expected to be useful in different time measurement applications. First measurement results of a CMOS integrated logarithmic amplifier, which is part of the analog continuous-time divider, agree well with the corresponding simulations. Moreover, SPICE simulations of the integrated discriminator circuit promise a time walk well below 200 ps (FWHM) over a 40 dB input amplitude dynamic range

Discrimination and chemical phylogenetic study of seven species of Dendrobium using infrared spectroscopy combined with cluster analysis

Science.gov (United States)

Luo, Congpei; He, Tao; Chun, Ze

2013-04-01

Dendrobium is a commonly used and precious herb in Traditional Chinese Medicine. The high biodiversity of Dendrobium and the therapeutic needs require tools for the correct and fast discrimination of different Dendrobium species. This study investigates Fourier transform infrared spectroscopy followed by cluster analysis for discrimination and chemical phylogenetic study of seven Dendrobium species. Despite the general pattern of the IR spectra, different intensities, shapes, peak positions were found in the IR spectra of these samples, especially in the range of 1800-800 cm-1. The second derivative transformation and alcoholic extracting procedure obviously enlarged the tiny spectral differences among these samples. The results indicated each Dendrobium species had a characteristic IR spectra profile, which could be used to discriminate them. The similarity coefficients among the samples were analyzed based on their second derivative IR spectra, which ranged from 0.7632 to 0.9700, among the seven Dendrobium species, and from 0.5163 to 0.9615, among the ethanol extracts. A dendrogram was constructed based on cluster analysis the IR spectra for studying the chemical phylogenetic relationships among the samples. The results indicated that D. denneanum and D. crepidatum could be the alternative resources to substitute D. chrysotoxum, D. officinale and D. nobile which were officially recorded in Chinese Pharmacopoeia. In conclusion, with the advantages of high resolution, speediness and convenience, the experimental approach can successfully discriminate and construct the chemical phylogenetic relationships of the seven Dendrobium species.

Evaluation of granulated BGO, GSO:Ce, YAG:Ce, CaF sub 2 :Eu and ZnS:Ag for alpha/beta pulse shape discrimination in a flow-cell radiation detector

CERN Document Server

Devol, T A; Fjeld, R A

1999-01-01

Granulated BGO, GSO:Ce, YAG:Ce, and CaF sub 2 :Eu; CaF sub 2 :Eu coated with a fluorescent polymer, and combinations of coated and uncoated CaF sub 2 :Eu with ZnS:Ag were evaluated for their ability to discriminate between alpha and beta particles in a flow-cell radiation detector. The evaluations were based on the analysis of pulse shape spectra. Various granulated scintillators were packed into flow cell detectors that were coils of 3.0 mm ODx1.5 mm ID fluorinated ethylene propylene Teflon[reg] tubing positioned between dual photomultiplier tubes for analysis. The best pulse shape discrimination was obtained for a combination of equal masses of uncoated CaF sub 2 :Eu (63-90 mu m) and ZnS:Ag (10 mu m), which had a 9% spillover. Additional research is needed to reduce the spillover.

The Shape of Utility Functions and Organizational Behavior

NARCIS (Netherlands)

J.M.E. Pennings; A. Smidts (Ale)

2002-01-01

textabstractBased on measurements with 332 owner-managers, the global shape of the utility function (i.e., S-shaped versus concave or convex over the total range of outcomes) appears to discriminate organizational behavior. Whereas the degree of risk aversion, based on the local shape of the utility

Shape-based assessment of vertebral fracture risk in postmenopausal women using discriminative shape alignment

DEFF Research Database (Denmark)

Crimi, Alessandro; Loog, Marco; de Bruijne, Marleen

2012-01-01

RATIONALE AND OBJECTIVES: Risk assessment of future osteoporotic vertebral fractures is currently based mainly on risk factors, such as bone mineral density, age, prior fragility fractures, and smoking. It can be argued that an osteoporotic vertebral fracture is not exclusively an abrupt event...... independently performed manual annotations of the vertebrae, and fracture prediction using shape features extracted from the baseline annotations was performed. This was implemented using posterior probabilities from a standard linear classifier. RESULTS: The classifier tested on the study population quantified...

Studies of pear-shaped nuclei using accelerated radioactive beams

CERN Document Server

Gaffney, L P; Scheck, M; Hayes, A B; Wenander, F; Albers, M; Bastin, B; Bauer, C; Blazhev, A; Bonig, S; Bree, N; Cederkall, J; Chupp, T; Cline, D; Cocolios, T E; Davinson, T; DeWitte, H; Diriken, J; Grahn, T; Herzan, A; Huyse, M; Jenkins, D G; Joss, D T; Kesteloot, N; Konki, J; Kowalczyk, M; Kroll, Th; Kwan, E; Lutter, R; Moschner, K; Napiorkowski, P; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Reynders, K; Rigby, S V; Robledo, L M; Rudigier, M; Sambi, S; Seidlitz, M; Siebeck, B; Stora, T; Thoele, P; Van Duppen, P; Vermeulen, M J; von Schmid, M; Voulot, D; Warr, N; Wimmer, K; Wrzosek-Lipska, K; Wu, C Y; Zielinska, M

2013-01-01

There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are ‘octupole deformed’, that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on and $^{224}$Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental...

The experience of discrimination by US and Internationally educated nurses in hospital practice in the USA: a qualitative study.

Science.gov (United States)

Wheeler, Rebecca M; Foster, Jennifer W; Hepburn, Kenneth W

2014-02-01

To document experiences of nurses educated abroad and in the USA in 2 urban hospitals in the southeastern USA. Nurses are responsible for providing quality patient care. Discrimination against nurses in the workplace may create hostile environments, potentially affecting patient care and leading to higher nurse attrition rates. Structuration theory posits that agents' interactions create structures. Agents' use of resources and rules shapes interactions, potentially changing the structures. In this study, nurses described interactions with patients and their families and other healthcare personnel, their strategies for managing interactions and rationales behind their selected strategy. This study employed a qualitative, explorative approach using structuration theory. In 2011, 42 internationally educated and 40 USA-educated nurses practising in two urban hospitals in the southeastern USA were interviewed about their experiences in the workplace. Forty-one nurses were re-interviewed to explore the issues raised in the preliminary round: 21 internationally educated and 20 USA. Transcripts were analysed using the constant comparative method. Although internationally educated nurses experienced more explicit discrimination, all nurses experienced discrimination from their patients, their nurse colleagues and/or other hospital personnel. Internationally educated nurses and USA nurses shared similar coping strategies. The prevalence of nurses' experiences of discrimination suggests that healthcare institutions need to strengthen policies to effectively address this harmful practice. More research is needed about discrimination against nurses in the workplace because discrimination may have serious psychological effects that impact nurse retention and the quality of patient care. © 2013 John Wiley & Sons Ltd.

Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

Directory of Open Access Journals (Sweden)

Honda Manabu

2006-12-01

Full Text Available Abstract Background It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1, is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D shapes on Mah-Jong tiles (Mah-Jong experts. Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. Results When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. Conclusion The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

Pulse shape discrimination using EJ-299-33 plastic scintillator coupled with a Silicon Photomultiplier array

International Nuclear Information System (INIS)

Liao, Can; Yang, Haori

2015-01-01

Recent developments in organic plastic scintillators capable of pulse shape discrimination (PSD) have gained much interest. Novel photon detectors, such as Silicon Photomultipliers (SiPMs), offer numerous advantages and can be used as an alternative to conventional photo multiplier tubes (PMTs) in many applications. In this work, we evaluate the PSD performance of the EJ-299-33 plastic scintillator coupled with a SiPM array. 2D PSD plots as well as the Figure of Merit (FOM) parameters are presented to demonstrate the PSD capability of EJ-299-33 using a SiPM as the light sensor. The best FOM of 0.76 was observed with a 1.0 MeVee (MeV-electron-equivalent) energy threshold, despite the high noise level of the SiPM array. A high-speed digital oscilloscope was used to acquire data, which was then processed offline in MATLAB. A performance comparison between two different PSD algorithms was carried out. The dependence of PSD quality on the sampling rate was also evaluated, stimulated by the interest to implement this setup for handheld applications where power consumption is crucial

[Application of the elliptic fourier functions to the description of avian egg shape].

Science.gov (United States)

Ávila, Dennis Denis

2014-12-01

Egg shape is difficult to quantify due to the lack of an exact formula to describe its geometry. Here I described a simple algorithm to characterize and compare egg shapes using Fourier functions. These functions can delineate any closed contour and had been previously applied to describe several biological objects. I described, step by step, the process of data acquisition, processing and the use of the SHAPE software to extract function coefficients in a study case. I compared egg shapes in three birds' species representing different reproductive strategies: Cuban Parakeet (Aratinga euops), Royal Tern (Thalasseus maximus) and Cuban Blackbird (Dives atroviolaceus). Using 73 digital pictures of eggs kept in Cuban scientific collections, I calculated Fourier descriptors with 4, 6, 8, 16 and 20 harmonics. Descriptors were reduced by a Principal Component Analysis and the scores of the eigen-values that account for 90% of variance were used in a Lineal Discriminant Function to analyze the possibility to differentiate eggs according to its shapes. Using four harmonics, the first five component accounted for 97% of shape variances; more harmonics diluted the variance increasing to eight the number of components needed to explain most of the variation. Convex polygons in the discriminant space showed a clear separation between species, allowing trustful discrimination (classification errors between 7-15%). Misclassifications were related to specific egg shape variability between species. In the study case, A. euops eggs were perfectly classified, but for the other species, errors ranged from 5 to 29% of misclassifications, in relation to the numbers or harmonics and components used. The proposed algorithm, despite its apparent mathematical complexity, showed many advantages to describe eggs shape allowing a deeper understanding of factors related to this variable.

Impaired somatosensory discrimination of shape in Parkinson's disease : Association with caudate nucleus dopaminergic function

NARCIS (Netherlands)

Weder, BJ; Leenders, KL; Vontobel, P; Nienhusmeier, M; Keel, A; Zaunbauer, W; Vonesch, T; Ludin, HP

1999-01-01

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness,

Timing properties and pulse shape discrimination of LAB-based liquid scintillator

International Nuclear Information System (INIS)

Li Xiaobo; Xiao Hualin; Cao Jun; Li Jin; Heng Yuekun; Ruan Xichao

2011-01-01

Linear Alkyl Benzene (LAB) is a promising liquid scintillator solvent in neutrino experiments because it has many appealing properties. The timing properties of LAB-based liquid scintillator have been studied through ultraviolet and ionization excitation in this study. The decay time of LAB, PPO and bis-MSB is found to be 48.6 ns, 1.55 ns and 1.5 ns, respectively. A model can describe the absorption and re-emission process between PPO and bis-MSB perfectly. The energy transfer time between LAB and PPO with different concentrations can be obtained via another model. We also show that the LAB-based liquid scintillator has good (n, γ) and (α, γ) discrimination power. (authors)

Associations of racial discrimination and parental discrimination coping messages with African American adolescent racial identity.

Science.gov (United States)

Richardson, Bridget L; Macon, Tamarie A; Mustafaa, Faheemah N; Bogan, Erin D; Cole-Lewis, Yasmin; Chavous, Tabbye M

2015-06-01

Research links racial identity to important developmental outcomes among African American adolescents, but less is known about the contextual experiences that shape youths' racial identity. In a sample of 491 African American adolescents (48% female), associations of youth-reported experiences of racial discrimination and parental messages about preparation for racial bias with adolescents' later racial identity were examined. Cluster analysis resulted in four profiles of adolescents varying in reported frequency of racial discrimination from teachers and peers at school and frequency of parental racial discrimination coping messages during adolescents' 8th grade year. Boys were disproportionately over-represented in the cluster of youth experiencing more frequent discrimination but receiving fewer parental discrimination coping messages, relative to the overall sample. Also examined were clusters of adolescents' 11th grade racial identity attitudes about the importance of race (centrality), personal group affect (private regard), and perceptions of societal beliefs about African Americans (public regard). Girls and boys did not differ in their representation in racial identity clusters, but 8th grade discrimination/parent messages clusters were associated with 11th grade racial identity cluster membership, and these associations varied across gender groups. Boys experiencing more frequent discrimination but fewer parental coping messages were over-represented in the racial identity cluster characterized by low centrality, low private regard, and average public regard. The findings suggest that adolescents who experience racial discrimination but receive fewer parental supports for negotiating and coping with discrimination may be at heightened risk for internalizing stigmatizing experiences. Also, the findings suggest the need to consider the context of gender in adolescents' racial discrimination and parental racial socialization.

Perceived and anticipated discrimination in people with mental illness--an interview study.

Science.gov (United States)

Hansson, Lars; Stjernswärd, Sigrid; Svensson, Bengt

2014-02-01

Studies on perceived discrimination of people with mental illness are largely lacking. The purpose of the study was to investigate perceived discrimination in a sample of users in contact with mental health services in Sweden. Interviews were conducted with 156 users, asking for perceived and anticipated discrimination during the last 2 years. Background characteristics were also collected. Perceived discrimination was common. Highest frequencies were reported regarding family (54%), avoidance by people who knew about the mental illness (53%) and in making or keeping friends (50%). A majority of those anticipating discrimination regarding job or education seeking, or starting a close relationship did not report having been discriminated in these areas. Previous hospitalizations were associated with discrimination, and age with anticipated discrimination. Public stigma and self-stigma have been reported to have a number of negative consequences for people with mental illness. Discrimination is part of this complex situation and this study showed that this largely affects a number of individual life areas posing an obstacle for social integration. Anticipated discrimination or self-stigma was also prevalent and it is pointed out that this to a great extent is an obstacle on its own without being promoted by actual experiences of discrimination.

Pairwise harmonics for shape analysis

KAUST Repository

Zheng, Youyi

2013-07-01

This paper introduces a simple yet effective shape analysis mechanism for geometry processing. Unlike traditional shape analysis techniques which compute descriptors per surface point up to certain neighborhoods, we introduce a shape analysis framework in which the descriptors are based on pairs of surface points. Such a pairwise analysis approach leads to a new class of shape descriptors that are more global, discriminative, and can effectively capture the variations in the underlying geometry. Specifically, we introduce new shape descriptors based on the isocurves of harmonic functions whose global maximum and minimum occur at the point pair. We show that these shape descriptors can infer shape structures and consistently lead to simpler and more efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.

Unravelling fears of genetic discrimination: an exploratory study of Dutch HCM families in an era of genetic non-discrimination acts.

Science.gov (United States)

Geelen, Els; Horstman, Klasien; Marcelis, Carlo L M; Doevendans, Pieter A; Van Hoyweghen, Ine

2012-10-01

Since the 1990s, many countries in Europe and the United States have enacted genetic non-discrimination legislation to prevent people from deferring genetic tests for fear that insurers or employers would discriminate against them based on that information. Although evidence for genetic discrimination exists, little is known about the origins and backgrounds of fears of discrimination and how it affects decisions for uptake of genetic testing. The aim of this article is to gain a better understanding of these fears and its possible impact on the uptake of testing by studying the case of hypertrophic cardiomyopathy (HCM). In a qualitative study, we followed six Dutch extended families involved in genetic testing for HCM for three-and-a-half years. Semi-structured interviews were conducted with 57 members of these families. Based on the narratives of the families, we suggest that fears of discrimination have to be situated in the broader social and life-course context of family and kin. We describe the processes in which families developed meaningful interpretations of genetic discrimination and how these interpretations affected family members' decisions to undergo genetic testing. Our findings show that fears of genetic discrimination do not so much stem from the opportunity of genetic testing but much more from earlier experiences of discrimination of diseased family members. These results help identify the possible limitations of genetic non-discrimination regulations and provide direction to clinicians supporting their clients as they confront issues of genetic testing and genetic discrimination.

Social discrimination, stress, and risk of unintended pregnancy among young women.

Science.gov (United States)

Hall, Kelli Stidham; Kusunoki, Yasamin; Gatny, Heather; Barber, Jennifer

2015-03-01

Prior research linking young women's mental health to family planning outcomes has often failed to consider their social circumstances and the intersecting biosocial mechanisms that shape stress and depression as well as reproductive outcomes during adolescence and young adulthood. We extend our previous work to investigate relationships between social discrimination, stress and depression symptoms, and unintended pregnancy among adolescent and young adult women. Data were drawn from 794 women aged 18-20 years in a longitudinal cohort study. Baseline and weekly surveys assessed psychosocial information including discrimination (Everyday Discrimination Scale), stress (Perceived Stress Scale), depression (Center for Epidemiologic Studies-Depression Scale), and reproductive outcomes. Multilevel, mixed-effects logistic regression and discrete-time hazard models estimated associations between discrimination, mental health, and pregnancy. Baron and Kenny's method was used to test mediation effects of stress and depression on discrimination and pregnancy. The mean discrimination score was 19/45 points; 20% reported moderate/high discrimination. Discrimination scores were higher among women with stress and depression symptoms versus those without symptoms (21 vs. 18 points for both, p women with moderate/high (23%) versus low (11%) discrimination (p Discrimination was associated with stress (adjusted relative risk ratio, [aRR], 2.2; 95% confidence interval [CI], 1.4-3.4), depression (aRR, 2.4; CI, 1.5-3.7), and subsequent pregnancy (aRR, 1.8; CI, 1.1-3.0). Stress and depression symptoms did not mediate discrimination's effect on pregnancy. Discrimination was associated with an increased risk of mental health symptoms and unintended pregnancy among these young women. The interactive social and biological influences on reproductive outcomes during adolescence and young adulthood warrant further study. Copyright © 2015 Society for Adolescent Health and Medicine. Published

A feed-forward spiking model of shape-coding by IT cells

Directory of Open Access Journals (Sweden)

August eRomeo

2014-05-01

Full Text Available The ability to recognize a shape is linked to figure-ground organization. Cell preferences appear to be correlated across contrast-polarity reversals and mirror reversals of polygon displays, but not so much across figure-ground (FG reversals. Here we present a network structure which explains both shape-coding by IT cells and the suppression of responses to figure-ground reversed stimuli. In the model figure-ground discrimination is achieved much before shape discrimination, that is itself evidenced by the difference in the spiking onsets of a couple of cells selective for two image categories.

Structural Discrimination

DEFF Research Database (Denmark)

Thorsen, Mira Skadegård

discrimination as two ways of articulating particular, opaque forms of racial discrimination that occur in everyday Danish (and other) contexts, and have therefore become normalized. I present and discuss discrimination as it surfaces in data from my empirical studies of discrimination in Danish contexts...

Discriminative power of visual attributes in dermatology.

Science.gov (United States)

Giotis, Ioannis; Visser, Margaretha; Jonkman, Marcel; Petkov, Nicolai

2013-02-01

Visual characteristics such as color and shape of skin lesions play an important role in the diagnostic process. In this contribution, we quantify the discriminative power of such attributes using an information theoretical approach. We estimate the probability of occurrence of each attribute as a function of the skin diseases. We use the distribution of this probability across the studied diseases and its entropy to define the discriminative power of the attribute. The discriminative power has a maximum value for attributes that occur (or do not occur) for only one disease and a minimum value for those which are equally likely to be observed among all diseases. Verrucous surface, red and brown colors, and the presence of more than 10 lesions are among the most informative attributes. A ranking of attributes is also carried out and used together with a naive Bayesian classifier, yielding results that confirm the soundness of the proposed method. proposed measure is proven to be a reliable way of assessing the discriminative power of dermatological attributes, and it also helps generate a condensed dermatological lexicon. Therefore, it can be of added value to the manual or computer-aided diagnostic process. © 2012 John Wiley & Sons A/S.

Discriminative power of visual attributes in dermatology

NARCIS (Netherlands)

Giotis, Ioannis; Visser, Margaretha; Jonkman, Marcel; Petkov, Nicolai

Background/purpose: Visual characteristics such as color and shape of skin lesions play an important role in the diagnostic process. In this contribution, we quantify the discriminative power of such attributes using an information theoretical approach. Methods: We estimate the probability of

Discriminant validity study of Achilles enthesis ultrasound.

Science.gov (United States)

Expósito Molinero, María Rosa; de Miguel Mendieta, Eugenio

2016-01-01

We want to know if the ultrasound examination of the Achilles tendon in spondyloarthritis is different compared to other rheumatic diseases. We studied 97 patients divided into five groups: rheumatoid arthritis, spondyloarthritis, gout, chondrocalcinosis and osteoarthritis, exploring six elementary lesions in 194 Achilles entheses examined. In our study the total index ultrasonographic Achilles is higher in spondyloarthritis with significant differences. The worst elementary spondyloarthritis lesions for discriminations against other pathologies were calcification. This study aims to demonstrate the discriminant validity of Achilles enthesitis observed by ultrasound in spondyloarthritis compared with other rheumatic diseases that may also have ultrasound abnormalities such enthesis level. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Pulse Shape Analysis and Discrimination for Silicon-Photomultipliers in Helium-4 Gas Scintillation Neutron Detector

Science.gov (United States)

Barker, Cathleen; Zhu, Ting; Rolison, Lucas; Kiff, Scott; Jordan, Kelly; Enqvist, Andreas

2018-01-01

Using natural helium (helium-4), the Arktis 180-bar pressurized gas scintillator is capable of detecting and distinguishing fast neutrons and gammas. The detector has a unique design of three optically separated segments in which 12 silicon-photomultiplier (SiPM) pairs are positioned equilaterally across the detector to allow for them to be fully immersed in the helium-4 gas volume; consequently, no additional optical interfaces are necessary. The SiPM signals were amplified, shaped, and readout by an analog board; a 250 MHz, 14-bit digitizer was used to examine the output pulses from each SiPMpair channel. The SiPM over-voltage had to be adjusted in order to reduce pulse clipping and negative overshoot, which was observed for events with high scintillation production. Pulse shaped discrimination (PSD) was conducted by evaluating three different parameters: time over threshold (TOT), pulse amplitude, and pulse integral. In order to differentiate high and low energy events, a 30ns gate window was implemented to group pulses from two SiPM channels or more for the calculation of TOT. It was demonstrated that pulses from a single SiPM channel within the 30ns window corresponded to low-energy gamma events while groups of pulses from two-channels or more were most likely neutron events. Due to gamma pulses having lower pulse amplitude, the percentage of measured gamma also depends on the threshold value in TOT calculations. Similarly, the threshold values were varied for the optimal PSD methods of using pulse amplitude and pulse area parameters. Helium-4 detectors equipped with SiPMs are excellent for in-the-field radiation measurement of nuclear spent fuel casks. With optimized PSD methods, the goal of developing a fuel cask content monitoring and inspection system based on these helium-4 detectors will be achieved.

Need for Studies of Sex Discrimination in Public Schools.

Science.gov (United States)

1972

This paper was designed to aid organizations seeking to eliminate sex discrimination in the public schools. Major emphasis was placed on the need for studies of sex discrimination. Six areas of investigation should include: 1) one sex schools; 2) one sex or practically one sex courses in co-ed schools; 3) physical education, sports and other extra…

Fast neutron-gamma discrimination on neutron emission profile measurement on JT-60U

International Nuclear Information System (INIS)

Ishii, K.; Okamoto, A.; Kitajima, S.; Sasao, M.; Shinohara, K.; Ishikawa, M.; Baba, M.; Isobe, M.

2010-01-01

A digital signal processing (DSP) system is applied to stilbene scintillation detectors of the multichannel neutron emission profile monitor in JT-60U. Automatic analysis of the neutron-γ pulse shape discrimination is a key issue to diminish the processing time in the DSP system, and it has been applied using the two-dimensional (2D) map. Linear discriminant function is used to determine the dividing line between neutron events and γ-ray events on a 2D map. In order to verify the validity of the dividing line determination, the pulse shape discrimination quality is evaluated. As a result, the γ-ray contamination in most of the beam heating phase was negligible compared with the statistical error with 10 ms time resolution.

Branch length similarity entropy-based descriptors for shape representation

Science.gov (United States)

Kwon, Ohsung; Lee, Sang-Hee

2017-11-01

In previous studies, we showed that the branch length similarity (BLS) entropy profile could be successfully used for the shape recognition such as battle tanks, facial expressions, and butterflies. In the present study, we proposed new descriptors, roundness, symmetry, and surface roughness, for the recognition, which are more accurate and fast in the computation than the previous descriptors. The roundness represents how closely a shape resembles to a circle, the symmetry characterizes how much one shape is similar with another when the shape is moved in flip, and the surface roughness quantifies the degree of vertical deviations of a shape boundary. To evaluate the performance of the descriptors, we used the database of leaf images with 12 species. Each species consisted of 10 - 20 leaf images and the total number of images were 160. The evaluation showed that the new descriptors successfully discriminated the leaf species. We believe that the descriptors can be a useful tool in the field of pattern recognition.

A new digital method for high precision neutron-gamma discrimination with liquid scintillation detectors

International Nuclear Information System (INIS)

Nakhostin, M

2013-01-01

A new pulse-shape discrimination algorithm for neutron and gamma (n/γ) discrimination with liquid scintillation detectors has been developed, leading to a considerable improvement of n/γ separation quality. The method is based on triangular pulse shaping which offers a high sensitivity to the shape of input pulses, as well as, excellent noise filtering characteristics. A clear separation of neutrons and γ-rays down to a scintillation light yield of about 65 keVee (electron equivalent energy) with a dynamic range of 45:1 was achieved. The method can potentially operate at high counting rates and is well suited for real-time measurements.

Challenging Racism in Brazil. Legal Suits in the Context of the 1951 Anti-Discrimination Law

Directory of Open Access Journals (Sweden)

Jerry Dávila

Full Text Available Abstract This article examines efforts to define the nature of racial discrimination in Brazil, within an environment shaped by perceptions of the meaning of racism in the United States and perceptions about the nature of race relations in the lusophone world. The article asks how did black Brazilians work to define discrimination, and what opportunities did they find to mount challenges? This study elucidates reactions to discrimination, looking for these acts where they occurred rather than where the U.S. experience tells us to find them, exploring efforts to define discrimination and to create means to challenge it. Though these efforts often dialogued with ever-present perceptions about race in the U.S., they were adapted to particular legal, political, social and cultural circumstances in the Brazil of their time. In particular, I examine challenges to discrimination through criminal suits brought under Brazil's 1951 anti-discrimination law.

Examining Workplace Discrimination in a Discrimination-Free Environment

OpenAIRE

Braxton, Shawn Lamont

2010-01-01

Examining Workplace Discrimination in a Discrimination-Free Environment Shawn L. Braxton Abstract The purpose of this study is to explore how racial and gender discrimination is reproduced in concrete workplace settings even when anti-discrimination policies are present, and to understand the various reactions utilized by those who commonly experience it. I have selected a particular medical center, henceforth referred to by a pseudonym, â The Bliley Medical Centerâ as my case ...

Study of signal discrimination for timing measurements

CERN Document Server

Krepelkova, Marta

2017-01-01

The timing detectors of the CMS-TOTEM Precision Proton Spectrometer (CT-PPS) are currently read out using discrete components, separated into three boards; the first board hosts the sensors and the amplifiers, the second one hosts the discriminators and the third is dedicated to the Time to Digital Converter (TDC) and to the interface with the data acquisition system (DAQ). This work proposes a new front-end electronics for the timing detector, with sensors, amplifiers and discriminators integrated on the same board. We simulated an updated version of the amplifier together with a discriminator designed using commercial components. We decided to use an LVDS buffer as a discriminator, because of its cost, availability, speed and lo w power consumption. As a proof of concept, we used the LVDS input of an FPGA to discriminate signals produced by a detector prototype, using a radioactive source.

Comparison of n-γ discrimination by zero-crossing and digital charge comparison methods

International Nuclear Information System (INIS)

Wolski, D.; Moszynski, M.; Ludziejewski, T.; Johnson, A.; Klamra, W.; Skeppstedt, Oe.

1995-01-01

A comparative study of the n-γ discrimination done by the digital charge comparison and zero-crossing methods was carried out for a 130 mm in diameter and 130 mm high BC501A liquid scintillator coupled to a 130 mm diameter XP4512B photomultiplier. The high quality of the tested detector was reflected in a photoelectron yield of 2300±100 phe/MeV and excellent n-γ discrimination properties with energy discrimination thresholds corresponding to very low neutron (or electron) energies. The superiority of the Z/C method was demonstrated for the n-γ discrimination method alone, as well as, for the simultaneous separation by the pulse shape discrimination and the time-of-flight methods down to about 30 keV recoil electron energy. The digital charge comparison method fails for a large dynamic range of energy and its separation is weakly improved by time-of-flight method for low energies. (orig.)

Pulse shape analysis using CsI(Tl) Crystals

International Nuclear Information System (INIS)

Silva, J.; Fiori, E.; Loher, B.; Savran, D.; Wirth, R.; Vencelj, M.

2013-06-01

The decay time of CsI(Tl) scintillating material consists of more than a single exponential component. The ratio between the intensity of these components varies as a function of the ionizing power of the absorbed particles, such as γ -rays or protons, and the temperature. This property can therefore be used for particle discrimination and for temperature monitoring, using pulse shape analysis. An unsupervised method that uses fuzzy clustering algorithms for particle identification based on pulse shape analysis is presented. The method is applied to discriminate between photon and proton-induced signals in CsI(Tl) scintillator detectors. The first results of a method that uses pulse shape analysis for correcting the temperature-dependent gain effect of the detector are also presented. The method aims at conserving a good energy resolution in a temperature varying environment without the need to measure the temperature of the detector externally (authors)

Focusing light through strongly scattering media using genetic algorithm with SBR discriminant

Science.gov (United States)

Zhang, Bin; Zhang, Zhenfeng; Feng, Qi; Liu, Zhipeng; Lin, Chengyou; Ding, Yingchun

2018-02-01

In this paper, we have experimentally demonstrated light focusing through strongly scattering media by performing binary amplitude optimization with a genetic algorithm. In the experiments, we control 160 000 mirrors of digital micromirror device to modulate and optimize the light transmission paths in the strongly scattering media. We replace the universal target-position-intensity (TPI) discriminant with signal-to-background ratio (SBR) discriminant in genetic algorithm. With 400 incident segments, a relative enhancement value of 17.5% with a ground glass diffuser is achieved, which is higher than the theoretical value of 1/(2π )≈ 15.9 % for binary amplitude optimization. According to our repetitive experiments, we conclude that, with the same segment number, the enhancement for the SBR discriminant is always higher than that for the TPI discriminant, which results from the background-weakening effect of SBR discriminant. In addition, with the SBR discriminant, the diameters of the focus can be changed ranging from 7 to 70 μm at arbitrary positions. Besides, multiple foci with high enhancement are obtained. Our work provides a meaningful reference for the study of binary amplitude optimization in the wavefront shaping field.

A toolbox to visually explore cerebellar shape changes in cerebellar disease and dysfunction

Science.gov (United States)

Abulnaga, S. Mazdak; Yang, Zhen; Carass, Aaron; Kansal, Kalyani; Jedynak, Bruno M.; Onyike, Chiadi U.; Ying, Sarah H.; Prince, Jerry L.

2016-03-01

The cerebellum plays an important role in motor control and is also involved in cognitive processes. Cerebellar function is specialized by location, although the exact topographic functional relationship is not fully understood. The spinocerebellar ataxias are a group of neurodegenerative diseases that cause regional atrophy in the cerebellum, yielding distinct motor and cognitive problems. The ability to study the region-specific atrophy patterns can provide insight into the problem of relating cerebellar function to location. In an effort to study these structural change patterns, we developed a toolbox in MATLAB to provide researchers a unique way to visually explore the correlation between cerebellar lobule shape changes and function loss, with a rich set of visualization and analysis modules. In this paper, we outline the functions and highlight the utility of the toolbox. The toolbox takes as input landmark shape representations of subjects' cerebellar substructures. A principal component analysis is used for dimension reduction. Following this, a linear discriminant analysis and a regression analysis can be performed to find the discriminant direction associated with a specific disease type, or the regression line of a specific functional measure can be generated. The characteristic structural change pattern of a disease type or of a functional score is visualized by sampling points on the discriminant or regression line. The sampled points are used to reconstruct synthetic cerebellar lobule shapes. We showed a few case studies highlighting the utility of the toolbox and we compare the analysis results with the literature.

A toolbox to visually explore cerebellar shape changes in cerebellar disease and dysfunction.

Science.gov (United States)

Abulnaga, S Mazdak; Yang, Zhen; Carass, Aaron; Kansal, Kalyani; Jedynak, Bruno M; Onyike, Chiadi U; Ying, Sarah H; Prince, Jerry L

2016-02-27

The cerebellum plays an important role in motor control and is also involved in cognitive processes. Cerebellar function is specialized by location, although the exact topographic functional relationship is not fully understood. The spinocerebellar ataxias are a group of neurodegenerative diseases that cause regional atrophy in the cerebellum, yielding distinct motor and cognitive problems. The ability to study the region-specific atrophy patterns can provide insight into the problem of relating cerebellar function to location. In an effort to study these structural change patterns, we developed a toolbox in MATLAB to provide researchers a unique way to visually explore the correlation between cerebellar lobule shape changes and function loss, with a rich set of visualization and analysis modules. In this paper, we outline the functions and highlight the utility of the toolbox. The toolbox takes as input landmark shape representations of subjects' cerebellar substructures. A principal component analysis is used for dimension reduction. Following this, a linear discriminant analysis and a regression analysis can be performed to find the discriminant direction associated with a specific disease type, or the regression line of a specific functional measure can be generated. The characteristic structural change pattern of a disease type or of a functional score is visualized by sampling points on the discriminant or regression line. The sampled points are used to reconstruct synthetic cerebellar lobule shapes. We showed a few case studies highlighting the utility of the toolbox and we compare the analysis results with the literature.

Cyclodextrin Films with Fast Solvent Transport and Shape-Selective Permeability

KAUST Repository

Villalobos, Luis Francisco

2017-04-24

This study describes the molecular-level design of a new type of filtration membrane made of crosslinked cyclodextrins-inexpensive macrocycles of glucose, shaped like hollow truncated cones. The channel-like cavities of cyclodextrins spawn numerous paths of defined aperture in the separation layer that can effectively discriminate between molecules. The transport of molecules through these membranes is highly shape-sensitive. In addition, the presence of hydrophobic (cavity) and hydrophilic (ester-crosslinked outer part) domains in these films results in high permeances for both polar and nonpolar solvents.

Synthesis of plastic scintillation microspheres: Alpha/beta discrimination

International Nuclear Information System (INIS)

Santiago, L.M.; Bagán, H.; Tarancón, A.; Garcia, J.F.

2014-01-01

Plastic scintillation microspheres (PSm) have been developed as an alternative for liquid scintillation cocktails due to their ability to avoid the mixed waste, besides other strengths in which the possibility for alpha/beta discrimination is included. The aim of this work was to evaluate the capability of PSm containing two combinations of fluorescence solutes (PPO/POPOP and pT/Bis-MSB) and variable amounts of a second organic solvent (naphthalene) to enhance the alpha/beta discrimination. Two commercial detectors with different Pulse Shape Discrimination performances (Quantulus and Triathler) were used to evaluate the alpha/beta discrimination. An optimal discrimination of alpha/beta particles was reached, with very low misclassification values (2% for beta particles and 0.5% for alpha particles), when PSm containing PPO/POPOP and between 0.6 and 2.0 g of naphthalene were evaluated using Triathler and the appropriate programme for data processing. - Highlights: • Plastic scintillation microspheres for α/β discrimination have been synthesised. • The energy transfer process in PSm with different compositions has been investigated. • The α/β discrimination capabilities of two commercial detectors have been evaluated. • 2% and 0.5% of misclassifications for β and α radionuclides have been achieved respectively

Pulse shape discrimination for Gerda Phase I data

Science.gov (United States)

Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barnabé Heider, M.; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Cossavella, F.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Ferella, A.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Guthikonda, K. K.; Hampel, W.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Liu, X.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Machado, A. A.; Majorovits, B.; Maneschg, W.; Misiaszek, M.; Nemchenok, I.; Nisi, S.; O'Shaughnessy, C.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Tarka, M.; Ur, C. A.; Vasenko, A. A.; Volynets, O.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

2013-10-01

The Gerda experiment located at the Laboratori Nazionali del Gran Sasso of INFN searches for neutrinoless double beta (0 νββ) decay of 76Ge using germanium diodes as source and detector. In Phase I of the experiment eight semi-coaxial and five BEGe type detectors have been deployed. The latter type is used in this field of research for the first time. All detectors are made from material with enriched 76Ge fraction. The experimental sensitivity can be improved by analyzing the pulse shape of the detector signals with the aim to reject background events. This paper documents the algorithms developed before the data of Phase I were unblinded. The double escape peak (DEP) and Compton edge events of 2.615 MeV γ rays from 208Tl decays as well as two-neutrino double beta (2 νββ) decays of 76Ge are used as proxies for 0 νββ decay. For BEGe detectors the chosen selection is based on a single pulse shape parameter. It accepts 0.92±0.02 of signal-like events while about 80 % of the background events at Q ββ =2039 keV are rejected. For semi-coaxial detectors three analyses are developed. The one based on an artificial neural network is used for the search of 0 νββ decay. It retains 90 % of DEP events and rejects about half of the events around Q ββ . The 2 νββ events have an efficiency of 0.85±0.02 and the one for 0 νββ decays is estimated to be . A second analysis uses a likelihood approach trained on Compton edge events. The third approach uses two pulse shape parameters. The latter two methods confirm the classification of the neural network since about 90 % of the data events rejected by the neural network are also removed by both of them. In general, the selection efficiency extracted from DEP events agrees well with those determined from Compton edge events or from 2 νββ decays.

Pulse shape discrimination for Gerda Phase I data

Energy Technology Data Exchange (ETDEWEB)

Agostini, M.; Bode, T.; Budjas, D.; Janicsko Csathy, J.; Lazzaro, A.; Schoenert, S. [Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Allardt, M.; Barros, N.; Domula, A.; Lehnert, B.; Wester, T.; Zuber, K. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); Andreotti, E. [Institute for Reference Materials and Measurements, Geel (Belgium); Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Bakalyarov, A.M.; Belyaev, S.T.; Lebedev, V.I.; Zhukov, S.V. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Balata, M.; Ioannucci, L.; Junker, M.; Laubenstein, M.; Macolino, C.; Nisi, S.; Pandola, L.; Zavarise, P. [LNGS, INFN Laboratori Nazionali del Gran Sasso, Assergi (Italy); Barabanov, I.; Bezrukov, L.; Gurentsov, V.; Inzhechik, L.V.; Kuzminov, V.V.; Lubsandorzhiev, B.; Yanovich, E. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Barnabe Heider, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Baudis, L.; Benato, G.; Ferella, A.; Guthikonda, K.K.; Tarka, M.; Walter, M. [Physik Institut der Universitaet Zuerich, Zuerich (Switzerland); Bauer, C.; Hampel, W.; Heisel, M.; Heusser, G.; Hofmann, W.; Kihm, T.; Kirsch, A.; Knoepfle, K.T.; Lindner, M.; Lubashevskiy, A.; Machado, A.A.; Maneschg, W.; Salathe, M.; Schreiner, J.; Schwingenheuer, B.; Simgen, H.; Smolnikov, A.; Strecker, H.; Wagner, V.; Wegmann, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Becerici-Schmidt, N.; Caldwell, A.; Cossavella, F.; Liao, H.Y.; Liu, X.; Majorovits, B.; O' Shaughnessy, C.; Schulz, O.; Volynets, O. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Bellotti, E.; Pessina, G. [Universita Milano Bicocca, Dipartimento di Fisica, Milano (Italy); INFN Milano Bicocca, Milano (Italy); Belogurov, S.; Kornoukhov, V.N. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bettini, A.; Brugnera, R.; Garfagnini, A.; Hemmer, S.; Sada, C. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); INFN Padova, Padova (Italy); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Rumyantseva, N.; Shevchik, E.; Zhitnikov, I.; Zinatulina, D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Cattadori, C.; Gotti, C. [INFN Milano Bicocca, Milano (Italy); Chernogorov, A.; Demidova, E.V.; Kirpichnikov, I.V.; Vasenko, A.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Falkenstein, R.; Freund, K.; Grabmayr, P.; Hegai, A.; Jochum, J.; Schmitt, C. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Frodyma, N.; Misiaszek, M.; Pelczar, K.; Wojcik, M.; Zuzel, G. [Jagiellonian University, Institute of Physics, Cracow (Poland); Gangapshev, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Hult, M.; Lutter, G. [Institute for Reference Materials and Measurements, Geel (Belgium); Klimenko, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Lippi, I.; Stanco, L.; Ur, C.A. [INFN Padova, Padova (Italy); Pullia, A.; Riboldi, S. [Universita degli Studi di Milano (IT); INFN Milano, Dipartimento di Fisica, Milano (IT); Shirchenko, M. [Joint Institute for Nuclear Research, Dubna (RU); National Research Centre ' ' Kurchatov Institute' ' , Moscow (RU); Sturm, K. von [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (IT); INFN Padova, Padova (IT); Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (DE)

2013-10-15

The Gerda experiment located at the Laboratori Nazionali del Gran Sasso of INFN searches for neutrinoless double beta (0{nu}{beta}{beta}) decay of {sup 76}Ge using germanium diodes as source and detector. In Phase I of the experiment eight semi-coaxial and five BEGe type detectors have been deployed. The latter type is used in this field of research for the first time. All detectors are made from material with enriched {sup 76}Ge fraction. The experimental sensitivity can be improved by analyzing the pulse shape of the detector signals with the aim to reject background events. This paper documents the algorithms developed before the data of Phase I were unblinded. The double escape peak (DEP) and Compton edge events of 2.615 MeV {gamma} rays from {sup 208}Tl decays as well as two-neutrino double beta (2{nu}{beta}{beta}) decays of {sup 76}Ge are used as proxies for 0{nu}{beta}{beta} decay. For BEGe detectors the chosen selection is based on a single pulse shape parameter. It accepts 0.92{+-}0.02 of signal-like events while about 80 % of the background events at Q{sub {beta}{beta}} =2039 keV are rejected. For semi-coaxial detectors three analyses are developed. The one based on an artificial neural network is used for the search of 0 {nu}{beta}{beta} decay. It retains 90 % of DEP events and rejects about half of the events around Q{sub {beta}{beta}}. The 2 {nu}{beta}{beta} events have an efficiency of 0.85 {+-}0.02 and the one for 0 {nu}{beta}{beta} decays is estimated to be 0.90{sup +0.05}{sub -0.09}. A second analysis uses a likelihood approach trained on Compton edge events. The third approach uses two pulse shape parameters. The latter two methods confirm the classification of the neural network since about 90 % of the data events rejected by the neural network are also removed by both of them. In general, the selection efficiency extracted from DEP events agrees well with those determined from Compton edge events or from 2{nu}{beta}{beta} decays. (orig.)

The shield of professional status: Comparing internationally educated nurses' and international medical graduates' experiences of discrimination.

Science.gov (United States)

Neiterman, Elena; Bourgeault, Ivy Lynn

2015-11-01

This article examines the intersecting roles of gender, ethnicity, and professional status in shaping the experiences of internationally educated health professionals in Canada. The article is based on 140 semi-structured qualitative interviews with internationally trained nurses and physicians who came to Canada within past 10 years with the intention to practice their profession. Describing the challenging process of professional integration in Canada, our participants highlighted incidents of discrimination they experienced along the way. Although some of the participants from both professional groups experienced racial discrimination, the context of those experiences differed. Physicians rarely reported instances of discrimination in communication with patients or nurses. Instead, they were concerned with instances of discrimination within their own professional group. Nurses, on the other hand, reported discrimination at the hands of patients and their families as well as racialization by physicians, management, and other nurses. We conclude our article with a reflection on the role that gender and professional status play in shaping the experiences of ethnic discrimination of internationally educated health professionals. © The Author(s) 2015.

The Role of Courts in Shaping Health Equity.

Science.gov (United States)

Hall, Mark A

2017-10-01

United States' courts have played a limited, yet key, role in shaping health equity in three areas of law: racial discrimination, disability discrimination, and constitutional rights. Executive and administrative action has been much more instrumental than judicial decisions in advancing racial equality in health care. Courts have been reluctant to intervene on racial justice because overt discrimination has largely disappeared, and the Supreme Court has interpreted civil rights laws in a fashion that restricts judicial authority to address more subtle or diffused forms of disparate impact. In contrast, courts have been more active in limiting disability discrimination by expanding the conditions that are considered disabling and by articulating and applying the operative concepts "reasonable accommodation" and "other qualified" in the context of both treatment and insurance coverage decisions. Finally, regarding constitutional rights, courts have had limited opportunity to intervene because, outside of specially protected arenas such as reproduction, constitutional law gives government wide discretion to define health and safety goals and methods. Thus, courts have had only a limited role in shaping health equity in the United States. It remains to be seen whether this will change under the Affordable Care Act or whatever health reform measure might replace it. Copyright © 2017 by Duke University Press.

Coincidence measurements in α/β/γ spectrometry with phoswich detectors using digital pulse shape discrimination analysis

International Nuclear Information System (INIS)

Celis, B. de; Fuente, R. de la; Williart, A.; Celis Alonso, B. de

2007-01-01

A novel system has been developed for the detection of low radioactivity levels using coincidence techniques. The device combines a phoswich detector for α/β/γ ray recognition with a fast digital card for electronic pulse analysis. The detector is able to discriminate different types of radiation in a mixed α/β/γ field and can be used in a coincidence mode by identifying the composite signal produced by the simultaneous detection of β particles in a plastic scintillator and γ rays in an NaI(Tl) scintillator. Use of a coincidence technique with phoswich detectors was proposed recently to verify the Nuclear Test Ban Treaty, which made it necessary to monitor the low levels of xenon radioisotopes produced by underground nuclear explosions. Previous studies have shown that combining CaF 2 (Eu) for β ray detection and NaI(Tl) for γ ray detection makes it difficult to identify the coincidence signals because of the similar fluorescence decay times of the two scintillators. With the device proposed here, it is possible to identify the coincidence events owing to the short fluorescence decay time of the plastic scintillator. The sensitivity of the detector may be improved by employing liquid scintillators, which allow low radioactivity levels from actinides to be measured when present in environmental samples. The device developed is simpler to use than conventional coincidence equipment because it uses a single detector and electronic circuit, and it offers fast and precise analysis of the coincidence signals by employing digital pulse shape analysis

Time resolution measurements with an improved discriminator and conical scintillators

International Nuclear Information System (INIS)

McGervey, J.D.; Vogel, J.; Sen, P.; Knox, C.

1977-01-01

A new constant fraction discriminator with improved stability and walk characteristics is described. The discriminator was used with RCA C31024 photomultiplier tubes to test scintillators of conical and cylindrical shapes. Conical scintillators of 2.54 cm base diameter, 1.0 cm top diameter, and 2.54 cm height gave a fwhm of 155 ps for 60 Co gamma rays; larger conical scintillators gave an improvement of 10-15% in fwhm over cylindrical scintillators of equal volume. (Auth.)

Intrinsic Evaluation of n/γ Discrimination in Organic Plastic Scintillators

International Nuclear Information System (INIS)

Blanc, Pauline; Hamel, Matthieu; Rocha, Licinio; Normand, Stephane; Pansu, Robert; Gobert, Fabrice; Lampre, Isabelle

2013-06-01

This paper is devoted to characterizing plastic scintillators with neutron/gamma (n/γ) discrimination abilities and understanding experimentally the photophysical processes downstream. This experimental work is divided into two main studies, neutron sources irradiations and optical photoionization on a range of organic scintillators. The commercial liquid and plastic scintillators, respectively BC-501A from Bicron and EJ-200 from Eljen, are used as references in term of respectively extremely high [1] and poor n/γ discrimination efficiency, or more precisely Triplet-Triplet Annihilation rate probabilities after nuclear irradiations. We have characterized a range of organic plastic scintillators including one developed in our laboratory that shows good discrimination efficiency when compared to plastics that discriminate from literature. For that purpose we use the well known charge comparison as a pulse shape discrimination (PSD) method. We have also studied raw wave forms acquired after neutron irradiation before any kind of treatment was applied and managed to separate two light components, prompt and delayed, thus two particle families. We have demonstrated that by exciting with a 70 femto-seconds pulsed Laser at the femtosecond up to 50 μJ at 260 nm, photoionization was achieved for a range of organic scintillators by observing a delayed light emission in the time decay fluorescence when the Laser energy deposited in the materials was increased. This work is ongoing at CEA in collaboration with the nuclear measurement industry Canberra and the Laboratoire de Chimie Physique from Orsay University. (authors)

Cardiovascular risk indicators and perceived race/ethnic discrimination in the Dallas Heart Study.

Science.gov (United States)

Albert, Michelle A; Ravenell, Joseph; Glynn, Robert J; Khera, Amit; Halevy, Nitsan; de Lemos, James A

2008-12-01

The objective of the study was to evaluate the association between race/ethnic (r/e) discrimination and subclinical cardiovascular disease (CVD). Although r/e discrimination is a chronic stressor that might have negative health effects, cardiovascular data related to experiences with discrimination among different r/e groups in the United States remain sparse. Using data from the Dallas Heart Study, we assessed the association between perceived r/e discrimination and traditional CVD risk factors, C-reactive protein (CRP), aortic plaque area and wall thickness, and coronary calcium (CAC) score among black, white, and Hispanic participants. Prevalent CAC was defined as a CAC score > or =10 Agatston units; CRP elevation was defined as > or =3 mg/L. Participants were asked, "Have you ever been discriminated against due to your race/ethnicity? (responses: yes, no, or don't know)". Blacks reported r/e discrimination more frequently than whites or Hispanics (P discrimination were more likely to be college graduates, to have a family history of myocardial infarction, and to be more physically active than blacks who did not report r/e discrimination (each P discrimination had a higher prevalence of smoking (P discrimination and aortic wall thickness, aortic plaque area, prevalent CAC, or elevated CRP in any of the r/e groups. Among blacks, stratification by gender and education did not change the observed relationship between perceived r/e discrimination and CAC or CRP. Although perceived r/e discrimination is associated with certain health characteristics that may result in negative health outcomes, in general, we found no association of r/e discrimination with either subclinical atherosclerosis as determined by CAC score, aortic wall thickness and aortic plaque area, or inflammation as assessed by elevated CRP levels.

Application of the A/E pulse shape discrimination method to first Ge-76 enriched BEGe detectors operated in GERDA

Energy Technology Data Exchange (ETDEWEB)

Lazzaro, Andrea; Agostini, Matteo; Budjas, Dusan; Schoenert, Stefan [Physik-Department E15, Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

2013-07-01

In 2013 the Gerda experiment will be upgraded to its second phase with more than double of the current {sup 76}Ge mass. The additional diodes are custom made Broad Energy Germanium (BEGe) detectors. This design has been chosen to enhance the pulse shape discrimination (PSD) capability, with respect to the Phase I coaxial detectors. The goal of Phase II is to improve by one order of magnitude the current background index; the PSD will bring a major contribution to this result. Since summer 2012 the first set of five enriched BEGe detectors are operated in Gerda Phase I. This offers us the possibility to test the PSD performances and the signal analysis in an environment as close as possible to the Gerda Phase II configuration. In this talk I present the A/E analysis, the calibration of the cut parameters and the results in terms of background reduction for the data taken with these enriched BEGe.

Influence of sampling properties of fast-waveform digitizers on neutron−gamma-ray, pulse-shape discrimination for organic scintillation detectors

International Nuclear Information System (INIS)

Flaska, Marek; Faisal, Muhammad; Wentzloff, David D.; Pozzi, Sara A.

2013-01-01

One of the most important questions to be answered with regard to digital pulse-shape discrimination (PSD) systems based on organic scintillators is: What sampling properties are required for a fast-waveform digitizer used for digitizing neutron/gamma-ray pulses, while an accurate PSD is desired? Answering this question is the main objective of this paper. Specifically, the paper describes the influence of the resolution and sampling frequency of a waveform digitizer on the PSD performance of organic scintillators. The results presented in this paper are meant to help the reader choosing a waveform digitizer with appropriate bit resolution and sampling frequency. The results presented here show that a 12-bit, 250-MHz digitizer is a good choice for applications that require good PSD performance. However, when more accurate PSD performance is the main requirement, this paper presents PSD figures of merit to qualify the impact of further increasing either sampling frequency or resolution of the digitizer

Wing shape variation associated with mimicry in butterflies.

Science.gov (United States)

Jones, Robert T; Le Poul, Yann; Whibley, Annabel C; Mérot, Claire; ffrench-Constant, Richard H; Joron, Mathieu

2013-08-01

Mimetic resemblance in unpalatable butterflies has been studied by evolutionary biologists for over a century, but has largely focused on the convergence in wing color patterns. In Heliconius numata, discrete color-pattern morphs closely resemble comimics in the distantly related genus Melinaea. We examine the possibility that the shape of the butterfly wing also shows adaptive convergence. First, simple measures of forewing dimensions were taken of individuals in a cross between H. numata morphs, and showed quantitative differences between two of the segregating morphs, f. elegans and f. silvana. Second, landmark-based geometric morphometric and elliptical Fourier outline analyses were used to more fully characterize these shape differences. Extension of these techniques to specimens from natural populations suggested that, although many of the coexisting morphs could not be discriminated by shape, the differences we identified between f. elegans and f. silvana hold in the wild. Interestingly, despite extensive overlap, the shape variation between these two morphs is paralleled in their respective Melinaea comimics. Our study therefore suggests that wing-shape variation is associated with mimetic resemblance, and raises the intriguing possibility that the supergene responsible for controlling the major switch in color pattern between morphs also contributes to wing shape differences in H. numata. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Plastic Scintillators for Pulse Shape Discrimination of Particle Types in Radiation Detection

Science.gov (United States)

Hajagos, Tibor Jacob

Organic scintillators have a long history in the field of radiation detection, dating back to some of the earliest studies of organic photophysics and optoelectronic properties. In particular, plastics have come to dominate the commercial market for organic scintillators, due to their low cost and ease of use and manufacturing, and more notably in spite of their poorer performance in many metrics. While there has been decades of active research since their inception, little progress has been made to improve upon the now well established compositions of commercial plastics, a notable exception being the recent development of plastic scintillators capable of pulse shape discrimination (PSD) of n/gamma radiation, which is of particular interest among governments and industry for the detection of illicit nuclear material and weapons. In recent years, much attention has been paid towards the study of luminescent organic materials, in particular due to the invention and widespread adoption of organic light emitting diode (OLED) based electronic devices, and the knowledge and lessons that have been fundamental to such fields have recently begun to be adopted by the organic scintilator community. In this work, new approaches to the design of both plastic scintillator components, and of the materials as a whole, are described, with particular emphasis paid towards the design and synthesis of small molecule scintillating dyes that are specifically tailored towards the development of PSD-capable plastic scintilators. In the first of these approaches, the design and synthesis of a highly soluble and polymerizable derivative of 9,10-diphenylanthracene is described, and the properties of plastic scintilators fabricated from this dye when copolymerized with poly(vinyl toluene) were investigated. This particular approach was used to demonstrate a proof-of-concept of PSD in highly loaded plastics stabilized through copolymerization of the primary dye, a strategy conceived to

Hard and soft age discrimination: the dual nature of workplace discrimination.

Science.gov (United States)

Stypinska, Justyna; Turek, Konrad

2017-03-01

The paper concentrates on the problem of age discrimination in the labour market and the way it can be conceptualised and measured in a multi-disciplinary way. The approach proposed here combines two understandings of age discrimination-a sociological and legal one, what allows for a fuller and expanded understanding of ageism in the workplace. At the heart of the study is a survey carried out in Poland with a sample of 1000 men and women aged 45-65 years. The study takes a deeper and innovative look into the issue of age discrimination in employment. Confirmatory factor analysis with WLSMV estimation and logistic regressions were used to test the hypotheses. The study shows that age discrimination in labour market can take on different forms: hard and soft, where the hard type of age discrimination mirrors the legally prohibited types of behaviours and those which relate to the actual decisions of employers which can impact on the employee's career development. The soft discrimination corresponds with those occurrences, which are not inscribed in the legal system per se, are occurring predominantly in the interpersonal sphere, but can nevertheless have negative consequences. Soft discrimination was experienced more often (28.6% of respondents) than hard discrimination (15.7%) with higher occurrences among women, persons in precarious job situation or residents of urban areas. The role of education was not confirmed to influence the levels of perceived age discrimination.

An examination of the relationships between acculturative stress, perceived discrimination, and eating disorder symptoms among ethnic minority college students.

Science.gov (United States)

Kwan, Mun Yee; Gordon, Kathryn H; Minnich, Allison M

2018-01-01

Empirical evidence suggests the importance of considering acculturative stress and perceived discrimination in understanding the mental health of ethnic minority groups, including their eating behaviors and associated psychopathology. The current study examined the effect of acculturative stress and perceived discrimination on eating disorder symptoms among ethnic minority undergraduate students. A total of 187 ethnic minority undergraduate students (41.2% men) completed this cross-sectional study by completing self-report questionnaires on a secure online system. Regression analyses revealed a main effect of acculturative stress on eating concern, shape concern, weight concern, drive for thinness, and bulimia but not restraint or body dissatisfaction. Gender moderated the effect of acculturative stress on drive for muscularity, suggesting that this effect was only significant in women, but not men. The main effect of perceived discrimination was significant for restraint, eating concern, shape concern, weight concern, and drive for muscularity but not drive for thinness, bulimia, or body dissatisfaction. Acculturative stress and perceived discrimination are important factors to consider in understanding the development and maintenance of eating disorder symptoms among ethnic minority populations. Targeting these two factors may improve the effectiveness of intervention programs for eating disorder symptoms among ethnic minority undergraduate students. Copyright © 2018 Elsevier Ltd. All rights reserved.

Attention Effects on Neural Population Representations for Shape and Location Are Stronger in the Ventral than Dorsal Stream

Science.gov (United States)

2018-01-01

Abstract We examined how attention causes neural population representations of shape and location to change in ventral stream (AIT) and dorsal stream (LIP). Monkeys performed two identical delayed-match-to-sample (DMTS) tasks, attending either to shape or location. In AIT, shapes were more discriminable when directing attention to shape rather than location, measured by an increase in mean distance between population response vectors. In LIP, attending to location rather than shape did not increase the discriminability of different stimulus locations. Even when factoring out the change in mean vector response distance, multidimensional scaling (MDS) still showed a significant task difference in AIT, but not LIP, indicating that beyond increasing discriminability, attention also causes a nonlinear warping of representation space in AIT. Despite single-cell attentional modulations in both areas, our data show that attentional modulations of population representations are weaker in LIP, likely due to a need to maintain veridical representations for visuomotor control. PMID:29876521

Perceived discrimination In Primary Healthcare in Europe: evidence from the cross-sectional QUALICOPC study.

Science.gov (United States)

Hanssens, Lise G M; Detollenaere, Jens D J; Van Pottelberge, Amelie; Baert, Stijn; Willems, Sara J T

2017-03-01

Recent figures show that discrimination in healthcare is still persistent in the European Union. Research has confirmed these results but focused mainly on the outcomes of perceived discrimination. Studies that take into account socioeconomic determinants of discrimination limit themselves to either ethnicity, income or education. This article explores the influence of several socioeconomic indicators (e.g. gender, age, income, education and ethnicity) on perceived discrimination in 30 European countries. Data from the QUALICOPC study were used. These data were collected between October 2011 and December 2013 in the participating countries. In total, 7183 GPs (general practitioners) and 61932 patients participated in the study, which had an average response rate of 74.1%. Data collection was co-ordinated by NIVEL (Dutch Institute for Research of Health Care). Bivariate binomial logistic regressions were used to estimate the impact of each socioeconomic indicator on perceived discrimination. Multivariate logistic regressions were used to estimate the unique effect of each indicator. Results indicate that in Europe, overall 7% of the respondents felt discriminated, ranging between 1.4% and 12.8% at the country level. With regard to socioeconomic determinants in perceived discrimination, income and age are both important indicators, with lower income groups and younger people having a higher chance to feel discriminated. In addition, we find significant influences of education, gender, age and ethnicity in several countries. In most countries, higher educated people, older people, women and the indigenous population appeared to feel less discriminated. In conclusion, perceived discrimination in healthcare is reported in almost all European countries, but there is large variation between European countries. A high prevalence of perceived discrimination within a country also does not imply a correlation between socioeconomic indicators and perceived discrimination. �

Does the experience of discrimination affect health? A cross-sectional study of Korean elders.

Science.gov (United States)

Chun, Heeran; Kang, Minah; Cho, Sung-il; Jung-Choi, Kyunghee; Jang, Soong-Nang; Khang, Young-Ho

2015-03-01

This study was conducted among 992 Koreans aged 60 to 89 to examine the effects of perceived discrimination on the health of an ethnically homogenous older population. Perceived discrimination was measured with a self-report instrument. Health outcomes included depressive symptoms, poor self-rated health, and chronic diseases. Of the elderly Koreans surveyed, 23.5% reported having experienced discrimination based on education, age, birthplace, birth order, or gender. Among women, 23.1% reported experiencing gender discrimination, compared to 0.9% among men. Men reported education and age discrimination most frequently-9.4% and 7.7%, respectively. Those who reported experiencing any discrimination were 2.19 times more likely to report depressive symptoms (95% confidence interval = 1.50-3.22) and 1.40 times more likely to report poor self-rated health (95% confidence interval = 1.02-1.93). The health effects of educational discrimination appeared most prominent. This study supports the positive associations between perceived discrimination and poorer health, particularly mental health, in later life. © 2013 APJPH.

A real-time neutron-gamma discriminator based on the support vector machine method for the time-of-flight neutron spectrometer

Science.gov (United States)

Wei, ZHANG; Tongyu, WU; Bowen, ZHENG; Shiping, LI; Yipo, ZHANG; Zejie, YIN

2018-04-01

A new neutron-gamma discriminator based on the support vector machine (SVM) method is proposed to improve the performance of the time-of-flight neutron spectrometer. The neutron detector is an EJ-299-33 plastic scintillator with pulse-shape discrimination (PSD) property. The SVM algorithm is implemented in field programmable gate array (FPGA) to carry out the real-time sifting of neutrons in neutron-gamma mixed radiation fields. This study compares the ability of the pulse gradient analysis method and the SVM method. The results show that this SVM discriminator can provide a better discrimination accuracy of 99.1%. The accuracy and performance of the SVM discriminator based on FPGA have been evaluated in the experiments. It can get a figure of merit of 1.30.

PICTORIAL INTERLUDES Flake-shaped rice bodies

African Journals Online (AJOL)

removing the rice bodies and the bursa.3. In summary: rice bodies can occur without underlying systemic disorder, have different shapes and sizes, and have specific signal characteristics on. MRI that allow discrimination from synovial chondromatosis. 1. Cheung HS, Ryan LM, Kozin F, McCarty DJ. Synovial origins of rice ...

Perceived discrimination and depressive symptoms among US Latinos: the modifying role of educational attainment.

Science.gov (United States)

Ward, Julia B; Feinstein, Lydia; Vines, Anissa I; Robinson, Whitney R; Haan, Mary N; Aiello, Allison E

2017-04-12

Despite growing evidence that discrimination may contribute to poor mental health, few studies have assessed this association among US Latinos. Furthermore, the interaction between discrimination and educational attainment in shaping Latino mental health is virtually unexplored. This study aims to examine the association between perceived discrimination and depressive symptoms and the modifying role of education among a population of Mexican-origin adults. We utilized population-based data from 629 Mexican-origin adults (mean age = 52.8 years) participating the Niños Lifestyle and Diabetes Study (2013-2014). Perceived discrimination was defined as responding 'sometimes' or 'often' to at least one item on the 9-item Everyday Discrimination Scale. High depressive symptoms were defined as scoring ≥10 on the CESD-10. We used log-binomial and linear-binomial models to estimate prevalence ratios (PR) and prevalence differences (PD), respectively, of high depressive symptoms for levels of perceived discrimination. Final models were adjusted for age, sex, education, cultural orientation, and nativity. General estimating equations were employed to account for within-family clustering. Prevalence of perceived discrimination and high depressive symptoms were 49.5% and 29.2%, respectively. Participants experiencing discrimination had higher depressive symptom prevalence than those never or rarely experiencing discrimination [PR = 1.94, 95% confidence interval (CI): 1.46-2.58; PD = 0.19, 95% CI: 0.12-0.27]. The strength of this association varied by education level. The association between discrimination and depressive symptoms was stronger among those with >12 years of education (PR = 2.69; PD = 0.24) compared to those with ≤12 years of education (PR = 1.36; PD = 0.09). US Latinos suffer a high burden of depressive symptoms, and discrimination may be an important driver of this burden. Our results suggest that effortful coping strategies, such

A novel perceptual discrimination training task: Reducing fear overgeneralization in the context of fear learning.

Science.gov (United States)

Ginat-Frolich, Rivkah; Klein, Zohar; Katz, Omer; Shechner, Tomer

2017-06-01

Generalization is an adaptive learning mechanism, but it can be maladaptive when it occurs in excess. A novel perceptual discrimination training task was therefore designed to moderate fear overgeneralization. We hypothesized that improvement in basic perceptual discrimination would translate into lower fear overgeneralization in affective cues. Seventy adults completed a fear-conditioning task prior to being allocated into training or placebo groups. Predesignated geometric shape pairs were constructed for the training task. A target shape from each pair was presented. Thereafter, participants in the training group were shown both shapes and asked to identify the image that differed from the target. Placebo task participants only indicated the location of each shape on the screen. All participants then viewed new geometric pairs and indicated whether they were identical or different. Finally, participants completed a fear generalization test consisting of perceptual morphs ranging from the CS + to the CS-. Fear-conditioning was observed through physiological and behavioural measures. Furthermore, the training group performed better than the placebo group on the assessment task and exhibited decreased fear generalization in response to threat/safety cues. The findings offer evidence for the effectiveness of the novel discrimination training task, setting the stage for future research with clinical populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Online Learning for Classification of Alzheimer Disease based on Cortical Thickness and Hippocampal Shape Analysis.

Science.gov (United States)

Lee, Ga-Young; Kim, Jeonghun; Kim, Ju Han; Kim, Kiwoong; Seong, Joon-Kyung

2014-01-01

Mobile healthcare applications are becoming a growing trend. Also, the prevalence of dementia in modern society is showing a steady growing trend. Among degenerative brain diseases that cause dementia, Alzheimer disease (AD) is the most common. The purpose of this study was to identify AD patients using magnetic resonance imaging in the mobile environment. We propose an incremental classification for mobile healthcare systems. Our classification method is based on incremental learning for AD diagnosis and AD prediction using the cortical thickness data and hippocampus shape. We constructed a classifier based on principal component analysis and linear discriminant analysis. We performed initial learning and mobile subject classification. Initial learning is the group learning part in our server. Our smartphone agent implements the mobile classification and shows various results. With use of cortical thickness data analysis alone, the discrimination accuracy was 87.33% (sensitivity 96.49% and specificity 64.33%). When cortical thickness data and hippocampal shape were analyzed together, the achieved accuracy was 87.52% (sensitivity 96.79% and specificity 63.24%). In this paper, we presented a classification method based on online learning for AD diagnosis by employing both cortical thickness data and hippocampal shape analysis data. Our method was implemented on smartphone devices and discriminated AD patients for normal group.

Handling conditional discrimination

NARCIS (Netherlands)

Zliobaite, I.; Kamiran, F.; Calders, T.G.K.

2011-01-01

Historical data used for supervised learning may contain discrimination. We study how to train classifiers on such data, so that they are discrimination free with respect to a given sensitive attribute, e.g., gender. Existing techniques that deal with this problem aim at removing all discrimination

Regularized Discriminant Analysis: A Large Dimensional Study

KAUST Repository

Yang, Xiaoke

2018-04-28

In this thesis, we focus on studying the performance of general regularized discriminant analysis (RDA) classifiers. The data used for analysis is assumed to follow Gaussian mixture model with different means and covariances. RDA offers a rich class of regularization options, covering as special cases the regularized linear discriminant analysis (RLDA) and the regularized quadratic discriminant analysis (RQDA) classi ers. We analyze RDA under the double asymptotic regime where the data dimension and the training size both increase in a proportional way. This double asymptotic regime allows for application of fundamental results from random matrix theory. Under the double asymptotic regime and some mild assumptions, we show that the asymptotic classification error converges to a deterministic quantity that only depends on the data statistical parameters and dimensions. This result not only implicates some mathematical relations between the misclassification error and the class statistics, but also can be leveraged to select the optimal parameters that minimize the classification error, thus yielding the optimal classifier. Validation results on the synthetic data show a good accuracy of our theoretical findings. We also construct a general consistent estimator to approximate the true classification error in consideration of the unknown previous statistics. We benchmark the performance of our proposed consistent estimator against classical estimator on synthetic data. The observations demonstrate that the general estimator outperforms others in terms of mean squared error (MSE).

Fundamental study on laser manipulation of contamination particles with determining shape, size and species

International Nuclear Information System (INIS)

Shimizu, Isao; Fujii, Taketsugu

1995-01-01

It has been desired to eliminate or collect the contamination particles of radioisotope in each sort of species or shape and size non-invasively. The shape and size of particle can be determined from the shape and distribution of diffraction pattern of particle in the parallel laser beam, the species of particle can be discriminated by the fluorescence from resonance of laser beam, or by the laser Raman scattering, and the particle suspended in the air or falling down in a vacuum can be levitated against the gravity and trapped by the radiation force and the trapping force of the focussed laser beam in the atmosphere or in a vacuum. For the purpose of the non-invasive manipulation of contamination particles, the laser manipulation technique, image processing technique with Multiplexed Matched Spatial Filter and the determination technique of laser Raman scattering or fluorescence from resonance of laser light were combined in the experiments. The shape, size and species of particles trapped in the focal plane of focused Ar laser beam can be determined simultaneously and instantaneously from the shape and intensity distributions of diffraction patterns of the particles in the irradiation of parallel coherent beam of He-Ne laser, and fluorescence from the resonance of YAG laser beam with variable wave length. In this research, a new technique is proposed to manipulate non-invasively the contamination particles determined with the shape, size and species in the atmosphere or in a vacuum, by laser beam. (author)

Population connectivity among geographic variants within the Lutjanidae (Pisces of the Mexican Pacific coast through fish scale shape recognition

Directory of Open Access Journals (Sweden)

Ana L. Ibáñez

2012-11-01

Full Text Available Fish scale shape was used to identify geographic variants among Lutjanidae (Lutjanus argentiventris, L. guttatus and L. peru. Specimens were collected from three different geographic areas, north to south of the tropical Pacific coast of Mexico: Puerto Vallarta (PV, Manzanillo (MA and Caleta de Campos (CC. Configuration of landmark coordinates of fish scales were scaled, translated and rotated using generalized procrustes analysis, followed by principal components analysis of resulting shape coordinates. Principal component scores were submitted to cross-validated discriminant analysis to determine the efficacy of scale landmarks for discrimination by geographic variants. This was done with shape and form (shape plus size. PV and MA were recognized as one population different from the CC sampling area. Using only shape (without size, identification rates predicted geographic variant membership much better than chance (91.3%, 70.6% and 85.4% for L. argentiventris, L. guttatus and L. peru, respectively, and taking size into account, classification is somewhat improved (90.6%, 80.1% and 87.5% for L. argentiventris, L. guttatus and L. peru, respectively. Consistency of the two populations for the three species shows non-fortuitous events. Population discrimination confirmed previous genetic studies that show a zoogeographic barrier between the North Equatorial Current and the California Current. The method is non-destructive, fast and less expensive than genetic analysis, thus allowing screening of many individuals for traceability of fish.

How discriminating are discriminative instruments?

Science.gov (United States)

Hankins, Matthew

2008-05-27

The McMaster framework introduced by Kirshner & Guyatt is the dominant paradigm for the development of measures of health status and health-related quality of life (HRQL). The framework defines the functions of such instruments as evaluative, predictive or discriminative. Evaluative instruments are required to be sensitive to change (responsiveness), but there is no corresponding index of the degree to which discriminative instruments are sensitive to cross-sectional differences. This paper argues that indices of validity and reliability are not sufficient to demonstrate that a discriminative instrument performs its function of discriminating between individuals, and that the McMaster framework would be augmented by the addition of a separate index of discrimination. The coefficient proposed by Ferguson (Delta) is easily adapted to HRQL instruments and is a direct, non-parametric index of the degree to which an instrument distinguishes between individuals. While Delta should prove useful in the development and evaluation of discriminative instruments, further research is required to elucidate the relationship between the measurement properties of discrimination, reliability and responsiveness.

How discriminating are discriminative instruments?

Directory of Open Access Journals (Sweden)

Hankins Matthew

2008-05-01

Full Text Available Abstract The McMaster framework introduced by Kirshner & Guyatt is the dominant paradigm for the development of measures of health status and health-related quality of life (HRQL. The framework defines the functions of such instruments as evaluative, predictive or discriminative. Evaluative instruments are required to be sensitive to change (responsiveness, but there is no corresponding index of the degree to which discriminative instruments are sensitive to cross-sectional differences. This paper argues that indices of validity and reliability are not sufficient to demonstrate that a discriminative instrument performs its function of discriminating between individuals, and that the McMaster framework would be augmented by the addition of a separate index of discrimination. The coefficient proposed by Ferguson (Delta is easily adapted to HRQL instruments and is a direct, non-parametric index of the degree to which an instrument distinguishes between individuals. While Delta should prove useful in the development and evaluation of discriminative instruments, further research is required to elucidate the relationship between the measurement properties of discrimination, reliability and responsiveness.

Association between perceived racial discrimination and hypertension: findings from the ELSA-Brasil study.

Science.gov (United States)

Mendes, Patrícia Miranda; Nobre, Aline Araújo; Griep, Rosane Härter; Guimarães, Joanna Miguez Nery; Juvanhol, Leidjaira Lopes; Barreto, Sandhi Maria; Pereira, Alexandre; Chor, Dóra

2018-03-01

"Pardos" and blacks in Brazil and blacks in the USA are at greater risk of developing arterial hypertension than whites, and the causes of this inequality are still little understood. Psychosocial and contextual factors, including racial discrimination, are indicated as conditions associated with this inequality. The aim of this study was to identify the association between perceived racial discrimination and hypertension. The study evaluated 14,012 workers from the ELSA-Brazil baseline population. Perceived discrimination was measured by the Lifetime Major Events Scale, adapted to Portuguese. Classification by race/color followed the categories proposed by Brazilian Institute of Geography and Statistics (IBGE). Hypertension was defined by standard criteria. The association between the compound variable - race/racial discrimination - and hypertension was estimated by Poisson regression with robust variance and stratified by the categories of body mass index (BMI) and sex. Choosing white women as the reference group, in the BMI 25kg/m2 and men in any BMI category, no effect of racial discrimination was identified. Despite the differences in point estimates of prevalence of hypertension between "pardo" women who reported and those who did not report discrimination, our results are insufficient to assert that an association exists between racial discrimination and hypertension.

Simulation of neutrons and gamma pulse signal and research on the pulse shape discrimination technology

International Nuclear Information System (INIS)

Zuo Guangxia; He Bin; Xu Peng; Qiu Xiaolin; Ma Wenyan; Li Sufen

2012-01-01

In neutrons detection, it is important to discriminate the neutron signals from the gamma-ray background. In this article, simulation of neutrons and gamma pulse signals is developed based on the LabVIEW platform. Two digital algorithms of the charge comparison method and the pulse duration time method are realized using 10000 simulation signals. Experimental results show that neutron and gamma pulse signals can be discriminated by the two methods, and the pulse duration time method is better than the charge comparison method. (authors)

An Efficient Digital Pulse Shape Discrimination Technique for Scintillation Detectors Based on FPGA

International Nuclear Information System (INIS)

Kamel, M.S.

2014-01-01

Different techniques for pulse discrimination (PSD) of the scintillation pulses have been developed. The PSD of scintillation pulese can been used in several applications as Positron Emission Topography (PET) system. Each technique analyzes the resulting pulses from the absorption of radiation in the scintillation pulses were filtered and digitized then it is captured using DAQ, and it sent to the host computer for processing. The spatial resolution of images that generated in PET system can be improved by applying the proposed PSD. In this thesis various digital PSD techniques are proposed to discriminate the scintillation pulses. These techniques are based on discrete sine transform (DST). discrete cosine transform (DCT). Discrete hartley transform (DHT), Discrete Goertzel transform (DGT),and principal component analysis (PCA). Then the output coefficients of the discrete transforms are classified using one of the following classifiers T-test,tuned, or support vector machine (SVM).

Density-Based 3D Shape Descriptors

Directory of Open Access Journals (Sweden)

Schmitt Francis

2007-01-01

Full Text Available We propose a novel probabilistic framework for the extraction of density-based 3D shape descriptors using kernel density estimation. Our descriptors are derived from the probability density functions (pdf of local surface features characterizing the 3D object geometry. Assuming that the shape of the 3D object is represented as a mesh consisting of triangles with arbitrary size and shape, we provide efficient means to approximate the moments of geometric features on a triangle basis. Our framework produces a number of 3D shape descriptors that prove to be quite discriminative in retrieval applications. We test our descriptors and compare them with several other histogram-based methods on two 3D model databases, Princeton Shape Benchmark and Sculpteur, which are fundamentally different in semantic content and mesh quality. Experimental results show that our methodology not only improves the performance of existing descriptors, but also provides a rigorous framework to advance and to test new ones.

Memory as discrimination: what distraction reveals.

Science.gov (United States)

Beaman, C Philip; Hanczakowski, Maciej; Hodgetts, Helen M; Marsh, John E; Jones, Dylan M

2013-11-01

Recalling information involves the process of discriminating between relevant and irrelevant information stored in memory. Not infrequently, the relevant information needs to be selected from among a series of related possibilities. This is likely to be particularly problematic when the irrelevant possibilities not only are temporally or contextually appropriate, but also overlap semantically with the target or targets. Here, we investigate the extent to which purely perceptual features that discriminate between irrelevant and target material can be used to overcome the negative impact of contextual and semantic relatedness. Adopting a distraction paradigm, it is demonstrated that when distractors are interleaved with targets presented either visually (Experiment 1) or auditorily (Experiment 2), a within-modality semantic distraction effect occurs; semantically related distractors impact upon recall more than do unrelated distractors. In the semantically related condition, the number of intrusions in recall is reduced, while the number of correctly recalled targets is simultaneously increased by the presence of perceptual cues to relevance (color features in Experiment 1 or speaker's gender in Experiment 2). However, as is demonstrated in Experiment 3, even presenting semantically related distractors in a language and a sensory modality (spoken Welsh) distinct from that of the targets (visual English) is insufficient to eliminate false recalls completely or to restore correct recall to levels seen with unrelated distractors . Together, the study shows how semantic and nonsemantic discriminability shape patterns of both erroneous and correct recall.

Racial discrimination, gender discrimination, and substance abuse among Latina/os nationwide.

Science.gov (United States)

Otiniano Verissimo, Angie Denisse; Gee, Gilbert C; Ford, Chandra L; Iguchi, Martin Y

2014-01-01

This study investigates the relationship between discrimination and substance abuse among Latina/os, and further examines whether this relationship differs by gender and type of discrimination. Analyses focus on the Latina/o respondents (n = 1,039 men; n = 1,273 women) from the National Latino and Asian American Study carried out from 2002-2003. Outcomes were alcohol abuse and drug abuse measured using DSM-IV definitions and criteria. Additional covariates included immigrant characteristics and demographics. Analyses were completed using gender-stratified multinomial logistic regression. Men reported more discrimination (39.6% vs. 30.3%) and had higher prevalence of alcohol abuse (16.5% vs. 4.5%) and drug abuse (9.5% vs. 2.3%) than women. Discrimination was significantly associated with increased risk of alcohol abuse for women and increased risk of drug abuse for men. Men and women also varied in the types of discrimination (e.g., racial vs. gender) reported, and in the associations between these types of discrimination and substance abuse. These data indicate that discrimination is associated with different substance abuse outcomes between genders. Future research should consider the mechanisms that explain these differences.

Familiar shapes attract attention in figure-ground displays.

Science.gov (United States)

Nelson, Rolf A; Palmer, Stephen E

2007-04-01

We report five experiments that explore the effect of figure-ground factors on attention. We hypothesized that figural cues, such as familiar shape, would draw attention to the figural side in an attentional cuing task using bipartite figure-ground displays. The first two experiments used faces in profile as the familiar shape and found a perceptual advantage for targets presented on the meaningful side of the central contour in detection speed (Experiment 1) and discrimination accuracy (Experiment 2). The third experiment demonstrated the figural advantage in response time (RT) with nine other familiar shapes (including a sea horse, a guitar, a fir tree, etc.), but only when targets appeared in close proximity to the contour. A fourth experiment obtained a figural advantage in a discrimination task with the larger set of familiar shapes. The final experiment ruled out eye movements as a possible confounding factor by replicating the RT advantage for targets on the figural side of face displays when all trials containing eye movements were eliminated. The results are discussed in terms of ecological influences on attention, and are cast within the framework of Yantis and Jonides's hypothesis that attention is exogenously drawn to the onset of new perceptual objects. We argue that the figural side constitutes an "object" whereas the ground side does not, and that figural cues such as shape familiarity are effective in determining which areas represent objects.

Figure-ground discrimination in the avian brain: the nucleus rotundus and its inhibitory complex.

Science.gov (United States)

Acerbo, Martin J; Lazareva, Olga F; McInnerney, John; Leiker, Emily; Wasserman, Edward A; Poremba, Amy

2012-10-01

In primates, neurons sensitive to figure-ground status are located in striate cortex (area V1) and extrastriate cortex (area V2). Although much is known about the anatomical structure and connectivity of the avian visual pathway, the functional organization of the avian brain remains largely unexplored. To pinpoint the areas associated with figure-ground segregation in the avian brain, we used a radioactively labeled glucose analog to compare differences in glucose uptake after figure-ground, color, and shape discriminations. We also included a control group that received food on a variable-interval schedule, but was not required to learn a visual discrimination. Although the discrimination task depended on group assignment, the stimulus displays were identical for all three experimental groups, ensuring that all animals were exposed to the same visual input. Our analysis concentrated on the primary thalamic nucleus associated with visual processing, the nucleus rotundus (Rt), and two nuclei providing regulatory feedback, the pretectum (PT) and the nucleus subpretectalis/interstitio-pretecto-subpretectalis complex (SP/IPS). We found that figure-ground discrimination was associated with strong and nonlateralized activity of Rt and SP/IPS, whereas color discrimination produced strong and lateralized activation in Rt alone. Shape discrimination was associated with lower activity of Rt than in the control group. Taken together, our results suggest that figure-ground discrimination is associated with Rt and that SP/IPS may be a main source of inhibitory control. Thus, figure-ground segregation in the avian brain may occur earlier than in the primate brain. Copyright © 2012 Elsevier Ltd. All rights reserved.

Workplace Discrimination and Depressive Symptoms: A Study of Multi-Ethnic Hospital Employees

OpenAIRE

Hammond, Wizdom Powell; Gillen, Marion; Yen, Irene H.

2010-01-01

Workplace discrimination reports have recently increased in the U.S. Few studies have examined racial/ethnic differences and the mental health consequences of this exposure. We examined the association between self-reported workplace discrimination and depressive symptoms among a multi-ethnic sample of hospital employees. Data came from the prospective case–control Gradients of Occupational Health in Hospital Workers (GROW) study (N = 664). We used the Center for Epidemiological Studies Depre...

Acculturation, Discrimination, and Depressive Symptoms among Chinese American Adolescents: A Longitudinal Study

Science.gov (United States)

Juang, Linda P.; Cookston, Jeffrey T.

2009-01-01

This study focused on the perceptions of discrimination for Chinese American adolescents: how perceptions changed over time, how generational status and acculturation were related to these changes, and whether earlier discrimination experiences were related to subsequent depressive symptomatology. The sample included 309 Chinese American…

Baseline drift effect on the performance of neutron and γ ray discrimination using frequency gradient analysis

International Nuclear Information System (INIS)

Liu Guofu; Luo Xiaoliang; Yang Jun; Lin Cunbao; Hu Qingqing; Peng Jinxian

2013-01-01

Frequency gradient analysis (FGA) effectively discriminates neutrons and γ rays by examining the frequency-domain features of the photomultiplier tube anode signal. This approach is insensitive to noise but is inevitably affected by the baseline drift similar to other pulse shape discrimination methods. The baseline drift effect is attributed to factors such as power line fluctuation, dark current, noise disturbances, hum, and pulse tail in front-end electronics. This effect needs to be elucidated and quantified before the baseline shift can be estimated and removed from the captured signal. Therefore, the effect of baseline shift on the discrimination performance of neutrons and γ rays with organic scintillation detectors using FGA is investigated in this paper. The relationship between the baseline shift and discrimination parameters of FGA is derived and verified by an experimental system consisting of an americium—beryllium source, a BC501A liquid scintillator detector, and a 5 GSample/s 8-bit oscilloscope. The theoretical and experimental results both show that the estimation of the baseline shift is necessary, and the removal of baseline drift from the pulse shapes can improve the discrimination performance of FGA. (authors)

Sending-Country Violence & Receiving-Country Discrimination: Effects on the Health of Colombian Refugees in Ecuador

Science.gov (United States)

Shedlin, Michele G.; Decena, Carlos U.; Noboa, Hugo; Betancourt, Óscar

2013-01-01

BACKGROUND This study explored factors affecting the health and well being of recent refugees from Colombia in Ecuador. Data collection focused on how sending-country violence and structural violence in a new environment affect immigrant health vulnerability and risk behaviors. METHODS A qualitative approach included ethnographic observation, media content analysis, focus groups, and individual interviews with refugees (N=137). The focus groups (5) provided perspectives on the research domains by sex workers; drug users; male and female refugees; and service providers. RESULTS Social and economic marginalization are impacting the health and well being of this growing refugee population. Data illustrate how stigma and discrimination affect food and housing security, employment and health services, and shape vulnerabilities and health risks in a new receiving environment. DISCUSSION Widespread discrimination in Ecuador reflects fears, misunderstanding, and stereotypes about Colombian refugees. For this displaced population, the sequelae of violence, combined with survival needs and lack of support and protections, shape new risks to health and well-being. PMID:23377565

Alpha/beta(gamma ray) discrimination and spillover quantification with a BaF2 scintillator

International Nuclear Information System (INIS)

DeVol, T.A.; Fjeld, R.A.

1994-01-01

A simple pulse shape discrimination technique was used to separate alpha and beta(gamma ray) interactions in a BaF 2 scintillator. The separation was not ideal, resulting in a 5.1% spillover of alpha interactions into the beta(gamma ray) channel and 11.9% spillover of beta(gamma ray) interactions into the alpha channel for a set pulse shape discriminator. The misclassification of events was reduced by post-processing the data using either a simple analytical technique or a more complex linear least squares technique. Both techniques typically reduced the difference between the expected and calculated interaction rates to <10% when the ratio of beta(gamma ray) to alpha count rate was less than 100 : 1. ((orig.))

Discrimination between biological interfaces and crystal-packing contacts

Directory of Open Access Journals (Sweden)

Yuko Tsuchiya

2008-11-01

Full Text Available Yuko Tsuchiya1, Haruki Nakamura2, Kengo Kinoshita1,31Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minatoku, Tokyo, 108-8639, Japan; 2Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan; 3Bioinformatics Research and Development, JST, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, JapanAbstract: A discrimination method between biologically relevant interfaces and artificial crystal-packing contacts in crystal structures was constructed. The method evaluates protein-protein interfaces in terms of complementarities for hydrophobicity, electrostatic potential and shape on the protein surfaces, and chooses the most probable biological interfaces among all possible contacts in the crystal. The method uses a discriminator named as “COMP”, which is a linear combination of the complementarities for the above three surface features and does not correlate with the contact area. The discrimination of homo-dimer interfaces from symmetry-related crystal-packing contacts based on the COMP value achieved the modest success rate. Subsequent detailed review of the discrimination results raised the success rate to about 88.8%. In addition, our discrimination method yielded some clues for understanding the interaction patterns in several examples in the PDB. Thus, the COMP discriminator can also be used as an indicator of the “biological-ness” of protein-protein interfaces.Keywords: protein-protein interaction, complementarity analysis, homo-dimer interface, crystal-packing contact, biological interfaces

Perceived discrimination and cancer screening behaviors in US Hispanics: the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study.

Science.gov (United States)

Valdovinos, Cristina; Penedo, Frank J; Isasi, Carmen R; Jung, Molly; Kaplan, Robert C; Giacinto, Rebeca Espinoza; Gonzalez, Patricia; Malcarne, Vanessa L; Perreira, Krista; Salgado, Hugo; Simon, Melissa A; Wruck, Lisa M; Greenlee, Heather A

2016-01-01

Perceived discrimination has been associated with lower adherence to cancer screening guidelines. We examined whether perceived discrimination was associated with adherence to breast, cervical, colorectal, and prostate cancer screening guidelines in US Hispanic/Latino adults. Data were obtained from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study, including 5,313 Hispanic adults aged 18–74 from Bronx, NY, Chicago, IL, Miami, FL, and San Diego, CA, and those who were within appropriate age ranges for specific screening tests were included in the analysis. Cancer screening behaviors were assessed via self-report. Perceived discrimination was measured using the Perceived Ethnic Discrimination Questionnaire. Confounder-adjusted multivariable polytomous logistic regression models assessed the association between perceived discrimination and adherence to cancer screening guidelines. Among women eligible for screening, 72.1 % were adherent to cervical cancer screening guidelines and 71.3 %were adherent to breast cancer screening guidelines. In participants aged 50–74, 24.6 % of women and 27.0 % of men were adherent to fecal occult blood test guidelines; 43.5 % of women and 34.8 % of men were adherent to colonoscopy/sigmoidoscopy guidelines; 41.0 % of men were adherent to prostate-specific antigen screening guidelines. Health insurance coverage, rather than perceived ethnic discrimination,was the variable most associated with receiving breast, cervical,colorectal, or prostate cancer screening. The influence of discrimination as a barrier to cancer screening may be modest among Hispanics/Latinos in urban US regions. Having health insurance facilitates cancer screening in this population. Efforts to increase cancer screening in Hispanics/Latinos should focus on increasing access to these services, especially among the uninsured.

Spatial discrimination and visual discrimination

DEFF Research Database (Denmark)

Haagensen, Annika M. J.; Grand, Nanna; Klastrup, Signe

2013-01-01

Two methods investigating learning and memory in juvenile Gottingen minipigs were evaluated for potential use in preclinical toxicity testing. Twelve minipigs were tested using a spatial hole-board discrimination test including a learning phase and two memory phases. Five minipigs were tested...... in a visual discrimination test. The juvenile minipigs were able to learn the spatial hole-board discrimination test and showed improved working and reference memory during the learning phase. Performance in the memory phases was affected by the retention intervals, but the minipigs were able to remember...... the concept of the test in both memory phases. Working memory and reference memory were significantly improved in the last trials of the memory phases. In the visual discrimination test, the minipigs learned to discriminate between the three figures presented to them within 9-14 sessions. For the memory test...

Item information and discrimination functions for trinary PCM items

NARCIS (Netherlands)

Akkermans, Wies; Muraki, Eiji

1997-01-01

For trinary partial credit items the shape of the item information and the item discrimination function is examined in relation to the item parameters. In particular, it is shown that these functions are unimodal if δ2 – δ1 < 4 ln 2 and bimodal otherwise. The locations and values of the maxima are

[Discrimination perceived by people with a diagnosis of schizophrenic disorders. INternational study of DIscrimination and stiGma Outcomes (INDIGO): French results].

Science.gov (United States)

Daumerie, N; Vasseur Bacle, S; Giordana, J-Y; Bourdais Mannone, C; Caria, A; Roelandt, J-L

2012-06-01

The INDIGO study (INternational study of DIscrimination and stiGma Outcomes) aims at assessing the impact of schizophrenic disorders diagnosis on privacy, social and professional life, in terms of discrimination. In the general population, and even among health and social professionals, erroneous negative stereotypes (double personality, dangerosity) lead to high social distance. And this has an impact on various parts of daily life: employment, housing, compliance, self-esteem… About a tenth of the adult population suffers from mental disorders at any one time. These disorders now account for about 12% of the global impact of disability, and this will rise to 15% by the year 2020. People living with schizophrenia, for example, experience reduced social participation, whilst public images of mental illness and social reactions add a dimension of suffering, which has been described as a "second illness". Stigmatizing attitudes and discriminatory behavior among the general population against people with severe mental illness are common in all countries. Globally, little is known of effective interventions against stigma. It is clear that the negative effects of stigma can act as formidable barriers to active recovery. The INDIGO study intends to establish detailed international data on how stigma and discrimination affect the lives of people with a diagnosis of schizophrenia. The first aim of the INDIGO study is to conduct qualitative and quantitative interviews with 25 people with a diagnosis of schizophrenia in each participating site, to elicit information on how the condition affects their everyday lives, with a focus upon sites in Europe. The second is to gather data for all participating countries on the laws, policies and regulations which set a clear distinction between people with a diagnosis of mental illness and others, to establish an international profile of such discrimination. A new scale (Discrimination and Stigma Scale [DISC]), used in a face

Strategies of Iranian nurses to overcome professional discrimination: An explorative qualitative study.

Science.gov (United States)

Shohani, Masoumeh

2017-01-01

Discrimination is a situation in which individuals receive unequal social benefits in return for equal roles they play. They react to such a situation in different ways. This study aims at identifying the strategies used by Iranian nurses to overcome professional discrimination. This qualitative study was conducted with the participation of 23 nurses who worked in hospitals in the cities of Tehran, Tabriz, and Ilam. They were selected based on purposive sampling. Data were collected using deep and unstructured interviews in a period of time between May 2013 and June 2014. Interviews were simultaneously analyzed using conventional content analysis method after being transcribed. Ethical consideration: This study was approved by the Regional Committee of Medical Research Ethics. Also, voluntary participation, anonymity, and confidentiality were considered. "Presenting a positive image of oneself," "objection," and "expectation" were three themes extracted through data analysis. Organizational discrimination puts nurses under stress and pressure. Nurses react to unfair behavior in different ways. These reactions are harmful to an organization and lead to negative consequences. Professional discrimination has made nurses adopt strategies which would lead to such consequences, which in turn influences their performance as nurses.

Set discrimination of quantum states

International Nuclear Information System (INIS)

Zhang Shengyu; Ying Mingsheng

2002-01-01

We introduce a notion of set discrimination, which is an interesting extension of quantum state discrimination. A state is secretly chosen from a number of quantum states, which are partitioned into some disjoint sets. A set discrimination is required to identify which set the given state belongs to. Several essential problems are addressed in this paper, including the condition of perfect set discrimination, unambiguous set discrimination, and in the latter case, the efficiency of the discrimination. This generalizes some important results on quantum state discrimination in the literature. A combination of state and set discrimination and the efficiency are also studied

Automatic Sex Determination of Skulls Based on a Statistical Shape Model

Directory of Open Access Journals (Sweden)

Li Luo

2013-01-01

Full Text Available Sex determination from skeletons is an important research subject in forensic medicine. Previous skeletal sex assessments are through subjective visual analysis by anthropologists or metric analysis of sexually dimorphic features. In this work, we present an automatic sex determination method for 3D digital skulls, in which a statistical shape model for skulls is constructed, which projects the high-dimensional skull data into a low-dimensional shape space, and Fisher discriminant analysis is used to classify skulls in the shape space. This method combines the advantages of metrical and morphological methods. It is easy to use without professional qualification and tedious manual measurement. With a group of Chinese skulls including 127 males and 81 females, we choose 92 males and 58 females to establish the discriminant model and validate the model with the other skulls. The correct rate is 95.7% and 91.4% for females and males, respectively. Leave-one-out test also shows that the method has a high accuracy.

Cyclodextrin Films with Fast Solvent Transport and Shape-Selective Permeability

KAUST Repository

Villalobos, Luis Francisco; Huang, Tiefan; Peinemann, Klaus-Viktor

2017-01-01

paths of defined aperture in the separation layer that can effectively discriminate between molecules. The transport of molecules through these membranes is highly shape-sensitive. In addition, the presence of hydrophobic (cavity) and hydrophilic (ester

Sending-country violence and receiving-country discrimination: effects on the health of Colombian refugees in Ecuador.

Science.gov (United States)

Shedlin, Michele G; Decena, Carlos U; Noboa, Hugo; Betancourt, Óscar

2014-02-01

This study explored factors affecting the health and well being of recent refugees from Colombia in Ecuador. Data collection focused on how sending-country violence and structural violence in a new environment affect immigrant health vulnerability and risk behaviors. A qualitative approach included ethnographic observation, media content analysis, focus groups, and individual interviews with refugees (N = 137). The focus groups (5) provided perspectives on the research domains by sex workers; drug users; male and female refugees; and service providers. Social and economic marginalization are impacting the health and well being of this growing refugee population. Data illustrate how stigma and discrimination affect food and housing security, employment and health services, and shape vulnerabilities and health risks in a new receiving environment. Widespread discrimination in Ecuador reflects fears, misunderstanding, and stereotypes about Colombian refugees. For this displaced population, the sequelae of violence, combined with survival needs and lack of support and protections, shape new risks to health and well-being.

Asymmetry and irregularity border as discrimination factor between melanocytic lesions

Science.gov (United States)

Sbrissa, David; Pratavieira, Sebastião.; Salvio, Ana Gabriela; Kurachi, Cristina; Bagnato, Vanderlei Salvadori; Costa, Luciano Da Fontoura; Travieso, Gonzalo

2015-06-01

Image processing tools have been widely used in systems supporting medical diagnosis. The use of mobile devices for the diagnosis of melanoma can assist doctors and improve their diagnosis of a melanocytic lesion. This study proposes a method of image analysis for melanoma discrimination from other types of melanocytic lesions, such as regular and atypical nevi. The process is based on extracting features related with asymmetry and border irregularity. It were collected 104 images, from medical database of two years. The images were obtained with standard digital cameras without lighting and scale control. Metrics relating to the characteristics of shape, asymmetry and curvature of the contour were extracted from segmented images. Linear Discriminant Analysis was performed for dimensionality reduction and data visualization. Segmentation results showed good efficiency in the process, with approximately 88:5% accuracy. Validation results presents sensibility and specificity 85% and 70% for melanoma detection, respectively.

Perceived Discrimination, Harassment, and Abuse in Physician Assistant Education: A Pilot Study.

Science.gov (United States)

DiBaise, Michelle; Tshuma, Lisa; Ryujin, Darin; LeLacheur, Susan

2018-06-01

A 2014 meta-analysis found that by graduation, 16.6% of medical students had reported abuse, harassment, or discrimination and that this hostile environment caused an increase in depression and anxiety. The purpose of this research study was to increase the understanding of discrimination and psychological/physical abuse in physician assistant (PA) education programs and the potential impact on student attrition. Information was collected using an online, anonymous survey that asked about witnessed or experienced discrimination and psychological or physical abuse during the didactic and clinical years of training in PA programs in the United States. The survey received 1159 respondents, which represents 6.1% of total PA student enrollment. Up to 30% of respondents had witnessed or experienced discrimination, and up to 2.3% had experienced psychological abuse while in PA school. The majority of witnessed or experienced discrimination during PA education was not reported (retribution or they simply did not know who to report to, particularly if the incident involved faculty. Reducing the prevalence of discrimination in PA education requires recognition of this issue and targeted efforts to ensure that the infrastructure of every program is inclusive and values diversity of all kinds. The authors advocate that PA programs discuss their current institutional reporting structure; develop a universal curriculum on workplace violence, discrimination, and harassment; and develop value statements that explicitly identify diversity and equity as a core value as an important first step to improving the overall "climate" and culture of the program.

Study of sampling rate influence on neutron-gamma discrimination with stilbene coupled to a silicon photomultiplier.

Science.gov (United States)

Zhang, Jinglong; Moore, Michael E; Wang, Zhonghai; Rong, Zhou; Yang, Chaowen; Hayward, Jason P

2017-10-01

Choosing a digitizer with an appropriate sampling rate is often a trade-off between performance and economy. The influence of sampling rates on the neutron-gamma Pulse Shape Discrimination (PSD) with a solid stilbene scintillator coupled to a Silicon Photomultiplier was investigated in this work. Sampling rates from 125MSPS to 2GSPS from a 10-bit digitizer were used to collect detector pulses produced by the interactions of a Cf-252 source. Due to the decreased signal-to-noise ratio (SNR), the PSD performance degraded with reduced sampling rates. The reason of PSD performance degradation was discussed. Then, an efficient combination of filtering and digital signal processing (DSP) was then applied to suppress the timing noise and electronic background noise. The results demonstrate an improved PSD performance especially at low sampling rates, down to 125MSPS. Using filtering and DSP, the ascribed Figure of Merit (FOM) at 125keV ee (± 10keV ee ) increased from 0.95 to 1.02 at 125MSPS. At 300keV ee and above, all the FOMs are better than 2.00. Our study suggests that 250MSPS is a good enough sampling rate for neutron-gamma discrimination in this system in order to be sensitive to neutrons at and above ~ 125keV ee . Copyright © 2017 Elsevier Ltd. All rights reserved.

Discrimination and Anti-discrimination in Denmark

DEFF Research Database (Denmark)

Olsen, Tore Vincents

The purpose of this report is to describe and analyse Danish anti-discrimination legislation and the debate about discrimination in Denmark in order to identify present and future legal challenges. The main focus is the implementation of the EU anti-discrimination directives in Danish law...

Investigation of the performance of alpha particle counting and alpha-gamma discrimination by pulse shape with micro-pixel avalanche photodiode

International Nuclear Information System (INIS)

Ahmadov, G.; Madatov, R.; Sadigov, A.; Sadygov, Z.; Jafarova, E.; Ahmadov, G.; Sadygov, Z.; Olshevski, A.; Zerrouk, F.; Mukhtarov, R.

2015-01-01

Being capable measuring small lights gives possibility to use micro-pixel avalanche photodiodes with scintillators. It is shown two prototypes to use micro-pixel avalanche photodiodes with and without scintillators as alpha and gamma counters in this paper. First prototype is to use two micro-pixel avalanche photodiodes. One for detecting alpha particles and closer to it, the second one with a thin plastic scintillator for detecting gamma rays. Second prototype is called two-layers configuration in which it is used only one micro-pixel avalanche photodiode, but two scntillators with different decay times. One can distinquish alpha particle and gamma ray events by using pulse shape discrimination techniques in the two-layer configuration. In this work an alpha particle and gamma ray counting performance of micro-pixel avalanche photodiodes without scintillators and its combination of plastic and BGO+ plastic scintillators was investigated. Obtained results showed the detection performance of the micro-pixel avalanche photodiodes in combination with plastic scintillator was about the same as conventional semiconductor detectors

Perceived Discrimination in LGBTIQ Discourse: A Typology of Verbal Discrimination

Directory of Open Access Journals (Sweden)

Sol Rojas Lizana

2014-08-01

Full Text Available New within the field of Discourse Analysis, Perceived Discrimination (PD is the study of discourse that focuses on the perspective of the victims of discrimination. This article explores the experiences of verbal discrimination as reported by eighteen LGBTIQ participants during semi-structured, co-constructed interviews. Data were classified in order to develop a taxonomy of discrimination based on Mellor’s (2003, 2004. This taxonomy foregrounds two types of discrimination: verbal and behavioural. In this paper, I exemplify the forms of verbal discrimination encountered and offer an analysis of the discourse used in the construction of the experiences and of the effects reported. The results show that verbal discrimination is an overt phenomenon and that participants are stressed by the ever present possibility of facing it. Verbal discrimination is mainly triggered by a perceived transgression to the normalised standards of people’s behaviour, movements and look in a heterosexist society. It presents three subtypes: name calling, abuse and remarks. These subtypes are described through the analysis of keywords, effects and expressions (such as faggot, gay, dyke, queer, the pronoun ‘it’, religious comments and other remarks. The type of discrimination used was associated with the level of acquaintance perpetrators have with the experiencers; that is, name calling was used by people unknown to the victims while abuse and remarks by acquaintances and family members. Participants resorted to several discursive strategies to convey their intentions. They used mitigation strategies when wanting to minimize the experience, hedging and repetition were used for emphasis, and to convey urgency and pervasiveness. Metaphorical expressions related to internal or external injuries were also used to express the powerful effect of verbal discrimination on people.

Family responsibilities discrimination, HR work-family discourse and organizational mediation of US civil rights law

OpenAIRE

Robin, Stryker; Heidi, Reynolds-Stenson; Krista, Frederico

2017-01-01

Because the US addresses work-family concerns mostly through voluntary employer-provided benefits combined with anti-discrimination legislation, organizational mediation of law shapes the content and impact of employ-ers’ response to employees’ work- family issues. Centrality of organiza-tional mediation means centrality of HR professional discourse. Given skyrocketing lawsuits claiming family responsibilities discrimination (FRD), we examine FRD-related discourse, 1980-2012, in the two high...

REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE I STUDY

Energy Technology Data Exchange (ETDEWEB)

Fox, K; James Newell, J; Tommy Edwards, T; David Best, D; Irene Reamer, I; Phyllis Workman, P

2008-02-13

studied HLW glasses with relatively high Al{sub 2}O{sub 3} compositions of 25 wt % or greater and nepheline discriminator values well below 0.62 have been shown to be free of nepheline crystallization upon quenching and slow cooling. Thus, the current nepheline discriminator equation also appears to be conservative for some HLW glass compositions. Refining the nepheline discriminator to include other important components and to reduce conservatism may provide access to high Al{sub 2}O{sub 3} concentration glass compositions for the DWPF, which could in turn allow access to higher waste loadings, decreased washing and improved waste throughput. The objective of this study was to develop and characterize a series of HLW glass compositions based on a projected composition of Sludge Batch 5 (SB5), the next sludge batch to be processed in the DWPF. The selected glass compositions all had nepheline discriminator values below the current limit of 0.62. They cover a range of locations on the SiO{sub 2}-Na{sub 2}O-Al{sub 2}O{sub 3} diagram. They also include varying amounts of B{sub 2}O{sub 3} and CaO to support an evaluation of the impact of these components on the propensity for nepheline crystallization. The results described in this report confirm that some conservatism exists in the current nepheline discriminator. Several glass compositions, particularly compositions that target higher Al{sub 2}O{sub 3} concentrations, were shown to be very durable (i.e., PCT responses that were more than an order of magnitude better than that of the Environmental Assessment benchmark glass) while their nepheline discriminator values were well below the current nepheline discriminator limit of 0.62. Increased concentrations of B{sub 2}O{sub 3} and increased concentrations of CaO were shown to improve durability responses and suppress the formation of nepheline. This provides incentive to revise the nepheline discriminator to reduce some of this conservatism and incorporate the influence of B

Rotation and scale invariant shape context registration for remote sensing images with background variations

Science.gov (United States)

Jiang, Jie; Zhang, Shumei; Cao, Shixiang

2015-01-01

Multitemporal remote sensing images generally suffer from background variations, which significantly disrupt traditional region feature and descriptor abstracts, especially between pre and postdisasters, making registration by local features unreliable. Because shapes hold relatively stable information, a rotation and scale invariant shape context based on multiscale edge features is proposed. A multiscale morphological operator is adapted to detect edges of shapes, and an equivalent difference of Gaussian scale space is built to detect local scale invariant feature points along the detected edges. Then, a rotation invariant shape context with improved distance discrimination serves as a feature descriptor. For a distance shape context, a self-adaptive threshold (SAT) distance division coordinate system is proposed, which improves the discriminative property of the feature descriptor in mid-long pixel distances from the central point while maintaining it in shorter ones. To achieve rotation invariance, the magnitude of Fourier transform in one-dimension is applied to calculate angle shape context. Finally, the residual error is evaluated after obtaining thin-plate spline transformation between reference and sensed images. Experimental results demonstrate the robustness, efficiency, and accuracy of this automatic algorithm.

Price discrimination in obstetric services--a case study in Bangladesh.

Science.gov (United States)

Amin, Mohammad; Hanson, Kara; Mills, Anne

2004-06-01

This article examines the existence of price discrimination for obstetric services in two private hospitals in Bangladesh, and considers the welfare consequences of such discrimination, i.e. whether or not price discrimination benefited the poorer users. Data on 1212 normal and caesarean section patients discharged from the two hospitals were obtained. Obstetric services were chosen because they are relatively standardised and the patient population is relatively homogeneous, so minimising the scope and scale of product differentiation due to procedure and case-mix differences. The differences between the hospital list price for delivery and actual prices paid by patients were calculated to determine the average rate of discount. The welfare consequences of price discrimination were assessed by testing the differences in mean prices paid by patients from three income groups: low, middle and high. The results suggest that two different forms of price discrimination for obstetric services occurred in both these hospitals. First, there was price discrimination according to income, with the poorer users benefiting from a higher discount rate than richer ones; and second, there was price discrimination according to social status, with three high status occupational groups (doctors, senior government officials, and large businessmen) having the highest probability of receiving some level of discount. Copyright 2003 John Wiley & Sons, Ltd.

Selective Beta and Gamma-ray Discrimination by CdWO{sub 4} and PlasticScintillator

Energy Technology Data Exchange (ETDEWEB)

Bae, Jun Woo; Kim, Hee Reyoung [Dept. of Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2017-04-15

Radiation monitoring technique has been used for monitoring of decommissioning site of nuclear facility, radioactive waste disposal site, or in case of radioactivity accident. For rapid measurement of gamma-ray and beta-ray, many portable radiation detectors were developed but they are sensitive to specific radiation type. For example, portable detectors using NaI(Tl) or high purity germanium (HPGe) are suitable to detect gamma-ray. Otherwise, Geiger-müller (GM) tube or ionization chamber are suitable to detect all-types of radiation but it is hard to determine which particle is detected in the detector. In this reason, phoswich detectors for discrimination of beta-ray and gamma-ray were developed by using pulse shape discrimination. In this study, another approach to discriminate the beta-ray and gamma-ray is carried out. Two scintillators are used, cadmium tungstate (CdWO{sub 4}) and plastic scintillator. They have huge difference in their effective atomic number and mass density, thus they have huge difference in their gamma-ray sensitivity while the sensitivity of beta-ray is similar. The characterization of beta-ray and gamma-ray discrimination by using this characteristics is include. A technique of discrimination between beta-ray and gamma-ray was suggested. The method was verified by Monte Carlo simulation and experiment. This work showed feasibility on in field measurement of radiation with discrimination of beta-ray and gamma-ray.

Quantum-state discrimination

International Nuclear Information System (INIS)

Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos

2002-01-01

A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions

Impaired capacity of cerebellar patients to perceive and learn two-dimensional shapes based on kinesthetic cues.

Science.gov (United States)

Shimansky, Y; Saling, M; Wunderlich, D A; Bracha, V; Stelmach, G E; Bloedel, J R

1997-01-01

This study addresses the issue of the role of the cerebellum in the processing of sensory information by determining the capability of cerebellar patients to acquire and use kinesthetic cues received via the active or passive tracing of an irregular shape while blindfolded. Patients with cerebellar lesions and age-matched healthy controls were tested on four tasks: (1) learning to discriminate a reference shape from three others through the repeated tracing of the reference template; (2) reproducing the reference shape from memory by drawing blindfolded; (3) performing the same task with vision; and (4) visually recognizing the reference shape. The cues used to acquire and then to recognize the reference shape were generated under four conditions: (1) "active kinesthesia," in which cues were acquired by the blindfolded subject while actively tracing a reference template; (2) "passive kinesthesia," in which the tracing was performed while the hand was guided passively through the template; (3) "sequential vision," in which the shape was visualized by the serial exposure of small segments of its outline; and (4) "full vision," in which the entire shape was visualized. The sequential vision condition was employed to emulate the sequential way in which kinesthetic information is acquired while tracing the reference shape. The results demonstrate a substantial impairment of cerebellar patients in their capability to perceive two-dimensional irregular shapes based only on kinesthetic cues. There also is evidence that this deficit in part relates to a reduced capacity to integrate temporal sequences of sensory cues into a complete image useful for shape discrimination tasks or for reproducing the shape through drawing. Consequently, the cerebellum has an important role in this type of sensory information processing even when it is not directly associated with the execution of movements.

Age discrimination in the workplace: validation of the Nordic Age Discrimination Scale (NADS).

Science.gov (United States)

Furunes, Trude; Mykletun, Reidar J

2010-02-01

Due to population ageing, older workers will make up a larger proportion of the workforce. However, recent reports show an increase in perceived age discrimination among older employees. Previous research found that age discrimination may result in negative feelings, such as uselessness, powerlessness and lower self-esteem. This study develops and validates a scale for monitoring age discrimination in the workplace. The validation study draws on three datasets, from Norway, Sweden and Finland respectively. The study provides a psychometric contribution to the study of the behavioral component of ageism.

To tell or not to tell? Examining the role of discrimination in the pregnancy disclosure process at work.

Science.gov (United States)

Jones, Kristen P

2017-04-01

Despite the rapid entrance of women into the workforce over the past several decades, many workplace experiences unique to women remain poorly understood. One critical, yet understudied, area is the intersection of work and pregnancy. Because pregnancy remains concealable for a substantial amount of time, expectant employees must navigate decisions regarding to whom, when, and how to disclose their pregnant identities at work. In light of evidence that has suggested pregnancy is often stigmatized within the workplace, I employed a retrospective longitudinal design to explore the extent to which women's expectations about discrimination-anticipated discrimination-shape their pregnancy disclosure behaviors, and the extent to which these different behavioral strategies are associated with higher or lower experienced discrimination. I also examined the link between pregnancy disclosure strategies and psychological distress. Taken together, findings suggest that pregnant employees' expectations about pregnancy discrimination play a role in shaping disclosure behaviors at work. Furthermore, certain behavioral strategies for pregnancy disclosure were linked with average reports of experienced discrimination and momentary reports of psychological distress. I also discuss theoretical and practical implications. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effects of X-ray radiation on complex visual discrimination learning and social recognition memory in rats.

Directory of Open Access Journals (Sweden)

Catherine M Davis

Full Text Available The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal. One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min, while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation.

Effects of X-ray radiation on complex visual discrimination learning and social recognition memory in rats.

Science.gov (United States)

Davis, Catherine M; Roma, Peter G; Armour, Elwood; Gooden, Virginia L; Brady, Joseph V; Weed, Michael R; Hienz, Robert D

2014-01-01

The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation.

Effects of X-Ray Radiation on Complex Visual Discrimination Learning and Social Recognition Memory in Rats

Science.gov (United States)

Davis, Catherine M.; Roma, Peter G.; Armour, Elwood; Gooden, Virginia L.; Brady, Joseph V.; Weed, Michael R.; Hienz, Robert D.

2014-01-01

The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation. PMID:25099152

[The discrimination of mono-syllable words in noise in listeners with normal hearing].

Science.gov (United States)

Yoshida, M; Sagara, T; Nagano, M; Korenaga, K; Makishima, K

1992-02-01

The discrimination of mono-syllable words (67S word-list) pronounced by a male and a female speaker was investigated in noise in 39 normal hearing subjects. The subjects listened to the test words at a constant level of 62 dB together with white or weighted noise in four S/N conditions. By processing the data with logit transformation, S/N-discrimination curves were presumed for each combination of a speech material and a noise. Regardless of the type of noise, the discrimination scores for the female voice started to decrease gradually at a S/N ratio of +10 dB, and reached 10 to 20% at-10 dB. For the male voice in white noise, the discrimination curve was similar to those for the female voice. On the contrary, the discrimination score for the male voice in weighted noise declined rapidly from a S/N ratio of +5 dB, and went below 10% at -5 dB. The discrimination curves seem to be shaped by the interrelations between the spectrum of the speech material and that of the noise.

Modeling Self-Occlusions/Disocclusions in Dynamic Shape and Appearance Tracking for Obtaining Precise Shape

KAUST Repository

Yang, Yanchao

2013-05-01

We present a method to determine the precise shape of a dynamic object from video. This problem is fundamental to computer vision, and has a number of applications, for example, 3D video/cinema post-production, activity recognition and augmented reality. Current tracking algorithms that determine precise shape can be roughly divided into two categories: 1) Global statistics partitioning methods, where the shape of the object is determined by discriminating global image statistics, and 2) Joint shape and appearance matching methods, where a template of the object from the previous frame is matched to the next image. The former is limited in cases of complex object appearance and cluttered background, where global statistics cannot distinguish between the object and background. The latter is able to cope with complex appearance and a cluttered background, but is limited in cases of camera viewpoint change and object articulation, which induce self-occlusions and self-disocclusions of the object of interest. The purpose of this thesis is to model self-occlusion/disocclusion phenomena in a joint shape and appearance tracking framework. We derive a non-linear dynamic model of the object shape and appearance taking into account occlusion phenomena, which is then used to infer self-occlusions/disocclusions, shape and appearance of the object in a variational optimization framework. To ensure robustness to other unmodeled phenomena that are present in real-video sequences, the Kalman filter is used for appearance updating. Experiments show that our method, which incorporates the modeling of self-occlusion/disocclusion, increases the accuracy of shape estimation in situations of viewpoint change and articulation, and out-performs current state-of-the-art methods for shape tracking.

Discrimination and delusional ideation.

Science.gov (United States)

Janssen, I; Hanssen, M; Bak, M; Bijl, R V; de Graaf, R; Vollebergh, W; McKenzie, K; van Os, J

2003-01-01

In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. To test whether perceived discrimination is associated longitudinally with onset of psychosis. A 3-year prospective study of cohorts with no history of psychosis and differential rates of reported discrimination on the basis of age, gender, disability, appearance, skin colour or ethnicity and sexual orientation was conducted in the Dutch general population (n=4076). The main outcome was onset of psychotic symptoms (delusions and hallucinations). The rate of delusional ideation was 0.5% (n=19) in those who did not report discrimination, 0.9% (n=4) in those who reported discrimination in one domain, and 2.7% (n=3) in those who reported discrimination in more than one domain (exact P=0.027). This association remained after adjustment for possible confounders. No association was found between baseline discrimination and onset of hallucinatory experiences. Perceived discrimination may induce delusional ideation and thus contribute to the high observed rates of psychotic disorder in exposed minority populations.

Blue colour preference in honeybees distracts visual attention for learning closed shapes.

Science.gov (United States)

Morawetz, Linde; Svoboda, Alexander; Spaethe, Johannes; Dyer, Adrian G

2013-10-01

Spatial vision is an important cue for how honeybees (Apis mellifera) find flowers, and previous work has suggested that spatial learning in free-flying bees is exclusively mediated by achromatic input to the green photoreceptor channel. However, some data suggested that bees may be able to use alternative channels for shape processing, and recent work shows conditioning type and training length can significantly influence bee learning and cue use. We thus tested the honeybees' ability to discriminate between two closed shapes considering either absolute or differential conditioning, and using eight stimuli differing in their spectral characteristics. Consistent with previous work, green contrast enabled reliable shape learning for both types of conditioning, but surprisingly, we found that bees trained with appetitive-aversive differential conditioning could additionally use colour and/or UV contrast to enable shape discrimination. Interestingly, we found that a high blue contrast initially interferes with bee shape learning, probably due to the bees innate preference for blue colours, but with increasing experience bees can learn a variety of spectral and/or colour cues to facilitate spatial learning. Thus, the relationship between bee pollinators and the spatial and spectral cues that they use to find rewarding flowers appears to be a more rich visual environment than previously thought.

A neural network approach to discrimination between defects and calyces in oranges

Directory of Open Access Journals (Sweden)

Salvatore Ingrassia

1993-11-01

Full Text Available The problem of automatic discrimination among pictures concerning either defects or calyces in oranges is approached. The method here proposed is based on a statistical analysis of the grey-levels and the shape of calyces in the pictures. Some suitable statistical indices are considered and the discriminant function is designed by means of a neural network on the basis of a suitable vector representation of the images. Numerical experiments give 5 misclassifications in a set of 52 images, where only three defects have been classified as calyces.

Statistical Shape Modelling and Markov Random Field Restoration (invited tutorial and exercise)

DEFF Research Database (Denmark)

Hilger, Klaus Baggesen

This tutorial focuses on statistical shape analysis using point distribution models (PDM) which is widely used in modelling biological shape variability over a set of annotated training data. Furthermore, Active Shape Models (ASM) and Active Appearance Models (AAM) are based on PDMs and have proven...... deformation field between shapes. The tutorial demonstrates both generative active shape and appearance models, and MRF restoration on 3D polygonized surfaces. ''Exercise: Spectral-Spatial classification of multivariate images'' From annotated training data this exercise applies spatial image restoration...... using Markov random field relaxation of a spectral classifier. Keywords: the Ising model, the Potts model, stochastic sampling, discriminant analysis, expectation maximization....

Perceiving discrimination in "real life" : Distinguishing negative events from discrimination attributions.

NARCIS (Netherlands)

Thijs, J.T.; Piscoi, Dea

2016-01-01

The present survey study examined a sample of ethnic minority preadolescents (ages 9–13) and made the empirical distinction between their exposure to peer victimization and the extent to which they attributed this to discrimination. Both peer victimization and the attribution to discrimination were

Perceived age discrimination in older adults.

Science.gov (United States)

Rippon, Isla; Kneale, Dylan; de Oliveira, Cesar; Demakakos, Panayotes; Steptoe, Andrew

2014-05-01

to examine perceived age discrimination in a large representative sample of older adults in England. this cross-sectional study of over 7,500 individuals used data from the fifth wave of the English Longitudinal Study of Ageing (ELSA), a longitudinal cohort study of men and women aged 52 years and older in England. Wave 5 asked respondents about the frequency of five everyday discriminatory situations. Participants who attributed any experiences of discrimination to their age were treated as cases of perceived age discrimination. Multivariable logistic regression analysis was used to estimate the odds ratios of experiencing perceived age discrimination in relation to selected sociodemographic factors. approximately a third (33.3%) of all respondents experienced age discrimination, rising to 36.8% in those aged 65 and over. Perceived age discrimination was associated with older age, higher education, lower levels of household wealth and being retired or not in employment. The correlates of age discrimination across the five discriminatory situations were similar. understanding age discrimination is vital if we are to develop appropriate policies and to target future interventions effectively. These findings highlight the scale of the challenge of age discrimination for older adults in England and illustrate that those groups are particularly vulnerable to this form of discrimination.

Provider Factors and Patient-Reported Healthcare Discrimination in the Diabetes Study of California (DISTANCE)

Science.gov (United States)

Lyles, Courtney R.; Karter, Andrew J.; Young, Bessie A.; Spigner, Clarence; Grembowski, David; Schillinger, Dean; Adler, Nancy

2011-01-01

Objective We examined provider-level factors and reported discrimination in the healthcare setting. Methods With data from the Diabetes Study of Northern California (DISTANCE)—a race-stratified survey of diabetes patients in Kaiser Permanente Northern California—we analyzed patient-reported racial/ethnic discrimination from providers. Primary exposures were characteristics of the primary care provider (PCP, who coordinates care in this system), including specialty/type, and patient-provider relationship variables including racial concordance. Results Subjects (n=12,151) included 20% black, 20% Latino, 23% Asian, 30% white, and 6% other patients, with 2% to 8% reporting discrimination by racial/ethnic group. Patients seeing nurse practitioners as their PCP (OR=0.09; 95% CI: 0.01–0.67), those rating their provider higher on communication (OR=0.70; 95% CI: 0.66–0.74) were less likely to report discrimination, while those with more visits (OR=1.10; 95% CI: 1.03–1.18) were more likely to report discrimination. Racial concordance was not significant once adjusting for patient race/ethnicity. Conclusions Among diverse diabetes patients in managed care, provider type and communication were significantly related to patient-reported discrimination. Practice Implications Given potential negative impacts on patient satisfaction and treatment decisions, future studies should investigate which interpersonal aspects of the provider-patient relationship reduce patient perceptions of unfair treatment. PMID:21605956

Differential discriminator

International Nuclear Information System (INIS)

Dukhanov, V.I.; Mazurov, I.B.

1981-01-01

A principal flowsheet of a differential discriminator intended for operation in a spectrometric circuit with statistical time distribution of pulses is described. The differential discriminator includes four integrated discriminators and a channel of piled-up signal rejection. The presence of the rejection channel enables the discriminator to operate effectively at loads of 14x10 3 pulse/s. The temperature instability of the discrimination thresholds equals 250 μV/ 0 C. The discrimination level changes within 0.1-5 V, the level shift constitutes 0.5% for the filling ratio of 1:10. The rejection coefficient is not less than 90%. Alpha spectrum of the 228 Th source is presented to evaluate the discriminator operation with the rejector. The rejector provides 50 ns time resolution

Timbre discrimination in musical patterns.

Science.gov (United States)

Grey, J M

1978-08-01

Most research on timbre perception has studied isolated tones. This study compares timbre discrimination of isolated tones with discrimination in various musical contexts, both single-voiced and multivoiced. Twelve different contexts were used (four isolated tonal comparisons, four single-voice musical patterns, and four multivoice patterns). Listerners judged whether the timbre remained the same or changed during the trial. Two possible versions of any instrumental timbre differed in the physical information used in their synthesis. Three instrumental timbres were tested in all contexts: clarinet, trumpet, and bassoon. The effects of context upon discrimination varied across instruments. The clarinet and trumpet versions were best discriminated in isolated contexts, with discrimination progressively worse in single-voice and multivoice patterns. The bassoon versions were best discriminated in the single-voice patterns, with equal discrimination in the isolated and multivoice cases. It is suggested that these results were due to pronounced physical differences observed between the spectra of the two versions of the bassoon that were not apparent between the versions of the clarinet or trumpet.

Perceived weight discrimination and chronic biochemical stress: A population?based study using cortisol in scalp hair

OpenAIRE

Jackson, Sarah E.; Kirschbaum, Clemens; Steptoe, Andrew

2016-01-01

Objective There is increasing evidence for weight?based discrimination against persons with obesity. This study aimed to examine the physiological impact of perceived weight discrimination on cortisol in hair, an indicator of chronic stress exposure. Methods Data were from 563 nonsmoking individuals with obesity (body mass index, BMI ?30 kg/m2) participating in the English Longitudinal Study of Ageing. Experiences of discrimination were reported via questionnaire, and hair cortisol concentrat...

Discrimination or Unobserved Differences in Characteristics?-An Empirical Study on Wage Inequality

OpenAIRE

Fang, Zheng; Sakellariou, Chris

2015-01-01

We apply the discrimination search model with wage-tenure contracts to NLSY79 data to study race/gender wage inequality with a focus on distinguishing unobserved productivity differences from discrimination in the labor market and also simulating the pattern of wage dynamics. Our findings suggest that the productivity differential between black and white workers is 3% of white worker productivity while productivity differences between men and women are estimated to be 3% of male productivity....

The Role of Discrimination in Care Postponement Among Trans-Feminine Individuals in the U.S. National Transgender Discrimination Survey.

Science.gov (United States)

Glick, Jennifer L; Theall, Katherine P; Andrinopoulos, Katherine M; Kendall, Carl

2018-04-01

This study examines the associations between discrimination experiences (types and locations) and care postponement among trans-feminine individuals in the United States. This secondary, cross-sectional study utilized a subset of the data from the National Transgender Discrimination Survey (n = 2248), specifically for trans-feminine individuals. In this analysis, we examined the relationship between discrimination and primary care postponement. Twenty-six percent (26.25%) of the study sample reported delaying preventive care due to fear of discrimination; 23.98%-46.66% of respondents reported past experiences of discrimination (setting dependent). Discrimination in health and non-health settings and different types of discrimination-being denied services, verbally harassed, or physically assaulted-were all significantly associated with delaying care; respondents reporting discrimination were up to 20 times more likely to postpone care. While discrimination at a health location had the strongest association with care postponement (adjusted odds ratio = 9.65, confidence interval = 7.60-12.24), discrimination in all non-health-related locations was also important. Individuals reporting discrimination in greater numbers of locations and multiple types of discrimination were more likely to postpone care. To promote preventive care-seeking, these results affirm the importance of interventions that promote discrimination-free environments for gender minorities.

Perceived weight discrimination in England: a population-based study of adults aged ⩾50 years.

Science.gov (United States)

Jackson, S E; Steptoe, A; Beeken, R J; Croker, H; Wardle, J

2015-05-01

Despite a wealth of experimental studies on weight bias, little is known about weight discrimination at the population level. This study examined the prevalence and socio-demographic correlates of perceived weight discrimination in a large population-based sample of older adults. Data were from 5307 adults in the English Longitudinal Study of Ageing; a population-based cohort of men and women aged ⩾50 years. Weight discrimination was reported for five domains (less respect/courtesy; treated as less clever; poorer treatment in medical settings; poorer service in restaurants/stores; threatened/harassed) at wave 5 (2010-2011). Height and weight were measured at wave 4 (2008-2009). We used logistic regression to test the odds of weight discrimination in relation to weight status, age, sex, wealth, education and marital status. Perceived weight discrimination in any domain was reported by 4.6% of participants, ranging from 0.8% in the normal-weight participants through 0.9, 6.7, 24.2 and 35.1% in individuals who were overweight or met criteria for class I, II and III obesity. Overall, and in each situation, odds of perceived weight discrimination were higher in younger and less wealthy individuals. There was no interaction between weight status and any socio-demographic variable. Relative to normal-weight participants, odds ratios for any perceived weight discrimination were 1.13 (95% confidence interval 0.53-2.40) in those who were overweight, 8.86 (4.65-16.88) in those with class I obesity, 35.06 (18.30-67.16) in class II obese and 56.43 (27.72-114.87) in class III obese. Our results indicate that rates of perceived weight discrimination are comparatively low in individuals who are overweight or have class I obesity, but for those with class II/III obesity, >10% had experienced discrimination in each domain, and >20% had been treated with less respect or courtesy. These findings have implications for public policy and highlight the need for effective interventions

Perceptions of weight discrimination: prevalence and comparison to race and gender discrimination in America.

Science.gov (United States)

Puhl, R M; Andreyeva, T; Brownell, K D

2008-06-01

Limited data are available on the prevalence and patterns of body weight discrimination from representative samples. This study examined experiences of weight/height discrimination in a nationally representative sample of US adults and compared their prevalence and patterns with discrimination experiences based on race and gender. Data were from the National Survey of Midlife Development in the United States, a 1995-1996 community-based survey of English-speaking adults aged 25-74 (N=2290). Reported experiences of weight/height discrimination included a variety of institutional settings and interpersonal relationships. Multivariate regression analyses were used to predict weight/height discrimination controlling for sociodemographic characteristics and body weight status. The prevalence of weight/height discrimination ranged from 5% among men to 10% among women, but these average percentages obscure the much higher risk of weight discrimination among heavier individuals (40% for adults with body mass index (BMI) of 35 and above). Younger individuals with a higher BMI had a particularly high risk of weight/height discrimination regardless of their race, education and weight status. Women were at greater risk for weight/height discrimination than men, especially women with a BMI of 30-35 who were three times more likely to report weight/height discrimination compared to male peers of a similar weight. Weight/height discrimination is prevalent in American society and is relatively close to reported rates of racial discrimination, particularly among women. Both institutional forms of weight/height discrimination (for example, in employment settings) and interpersonal mistreatment due to weight/height (for example, being called names) were common, and in some cases were even more prevalent than discrimination due to gender and race.

The parietal cortices participate in encoding, short-term memory, and decision-making related to tactile shape.

Science.gov (United States)

Rojas-Hortelano, Eduardo; Concha, Luis; de Lafuente, Victor

2014-10-15

We routinely identify objects with our hands, and the physical attributes of touched objects are often held in short-term memory to aid future decisions. However, the brain structures that selectively process tactile information to encode object shape are not fully identified. In this article we describe the areas within the human cerebral cortex that specialize in encoding, short-term memory, and decision-making related to the shape of objects explored with the hand. We performed event-related functional magnetic resonance imaging in subjects performing a shape discrimination task in which two sequentially presented objects had to be explored to determine whether they had the same shape or not. To control for low-level and nonspecific brain activations, subjects performed a temperature discrimination task in which they compared the temperature of two spheres. Our results show that although a large network of brain structures is engaged in somatosensory processing, it is the areas lining the intraparietal sulcus that selectively participate in encoding, maintaining, and deciding on tactile information related to the shape of objects. Copyright © 2014 the American Physiological Society.

Charged particle discrimination with silicon surface barrier detectors

International Nuclear Information System (INIS)

Coote, G.E.; Pithie, J.; Vickridge, I.C.

1996-01-01

The application for materials analysis of nuclear reactions that give rise to charged particles is a powerful surface analytical and concentration depth profiling technique. Spectra of charged particles, with energies in the range 0.1 to 15 MeV, emitted from materials irradiated with beams of light nuclei such as deuterons are measured with silicon surface barrier detectors. The spectra from multi-elemental materials typically encountered in materials research are usually composed of an overlapping superposition of proton, alpha, and other charged particle spectra. Interpretation of such complex spectra would be simplified if a means were available to electronically discriminate between the detector response to the different kinds of charged particle. We have investigated two methods of discriminating between different types of charged particles. The fast charge pulses from a surface barrier detector have different shapes, depending on the spatial distribution of energy deposition of the incident particle. Fast digitisation of the pulses, followed by digital signal processing provides one avenue for discrimination. A second approach is to use a thin transmission detector in front of a thick detector as a detector telescope. For a given incident energy, different types of charged particles will lose different amounts of energy in the thin detector, providing an alternative means of discrimination. We show that both approaches can provide significant simplification in the interpretation of charged particle spectra in practical situations, and suggest that silicon surface barrier detectors having graded electronic properties could provide improved discrimination compared to the current generation of detectors having homogeneous electronic properties. (author).12 refs., 2 tabs., 28 figs

Cross-sectional association between perceived discrimination and hypertension in African-American men and women: the Pitt County Study.

Science.gov (United States)

Roberts, Calpurnyia B; Vines, Anissa I; Kaufman, Jay S; James, Sherman A

2008-03-01

Few studies have examined the impact of the frequency of discrimination on hypertension risk. The authors assessed the cross-sectional associations between frequency of perceived racial and nonracial discrimination and hypertension among 1,110 middle-aged African-American men (n = 393) and women (n = 717) participating in the 2001 follow-up of the Pitt County Study (Pitt County, North Carolina). Odds ratios were estimated using gender-specific unconditional weighted logistic regression with adjustment for relevant confounders and the frequency of discrimination. More than half of the men (57%) and women (55%) were hypertensive. The prevalences of perceived racial discrimination, nonracial discrimination, and no discrimination were 57%, 29%, and 13%, respectively, in men and 42%, 43%, and 15%, respectively, in women. Women recounting frequent nonracial discrimination versus those reporting no exposure to discrimination had the highest odds of hypertension (adjusted odds ratio = 2.34, 95% confidence interval: 1.09, 5.02). A nonsignificant inverse odds ratio was evident in men who perceived frequent exposure to racial or nonracial discrimination in comparison with no exposure. A similar association was observed for women reporting perceived racial discrimination. These results indicate that the type and frequency of discrimination perceived by African-American men and women may differentially affect their risk of hypertension.

Perceived weight discrimination and chronic biochemical stress: A population‐based study using cortisol in scalp hair

Science.gov (United States)

Kirschbaum, Clemens; Steptoe, Andrew

2016-01-01

Objective There is increasing evidence for weight‐based discrimination against persons with obesity. This study aimed to examine the physiological impact of perceived weight discrimination on cortisol in hair, an indicator of chronic stress exposure. Methods Data were from 563 nonsmoking individuals with obesity (body mass index, BMI ≥30 kg/m2) participating in the English Longitudinal Study of Ageing. Experiences of discrimination were reported via questionnaire, and hair cortisol concentrations were determined from the scalp‐nearest 2‐cm hair segment. Height and weight were objectively measured. ANCOVAs tested associations between perceived weight discrimination and hair cortisol concentration overall and by degree of obesity. All analyses were adjusted for age, sex, ethnicity, socioeconomic status, and BMI. Results Mean hair cortisol concentrations were 33% higher in those who had experienced weight discrimination than those who had not (mean log pg/mg 1.241 vs. 0.933, F = 12.01, P = 0.001). The association between weight discrimination and hair cortisol was particularly pronounced in individuals with severe (class II/III) obesity (1.402 vs. 0.972, F = 11.58, P = 0.001). Conclusions Weight discrimination is associated with the experience of stress at a biological level. Chronic exposure to elevated levels of cortisol may play a role in generating a vicious circle of weight gain and discrimination and contribute to obesity‐associated health conditions. PMID:27740706

Study of n-γ discrimination by digital charge comparison method for a large volume liquid scintillator

International Nuclear Information System (INIS)

Moszynski, M.; Costa, G.J.; Guillaume, G.; Heusch, B.; Huck, A.; Ring, C.; Bizard, G.; Durand, D.; Peter, J.; Tamain, B.; El Masri, Y.; Hanappe, F.

1992-01-01

The study of the n-γ discrimination for a large 41 volume BC501A liquid scintillator coupled to a 130 mm diameter XP4512B photomultiplier was carried out by digital charge comparison method. A very good n-γ discrimination down to 100 keV of recoil electron energy was achieved. The measured relative intensity of the charge integrated at the slow component of the scintillation pulse and the photoelectron yield of the tested counter allow the factor of merit of the n-γ discrimination spectra to be calculated and to be compared with those measured experimentally. This shows that the main limitation of the n-γ discrimination is associated with the statistical fluctuation of the photoelectron number at the slow component. A serious effect of the distortion in the cable used to send the photomultiplier pulse to the electronics for the n-γ discrimination was studied. This suggests that the length of RG58 cable should be limited to about 40 m to preserve a high quality n-γ discrimination. (orig.)

Discrimination in Healthcare Settings is Associated with Disability in Older Adults: Health and Retirement Study, 2008-2012.

Science.gov (United States)

Rogers, Stephanie E; Thrasher, Angela D; Miao, Yinghui; Boscardin, W John; Smith, Alexander K

2015-10-01

As our society ages, improving medical care for an older population will be crucial. Discrimination in healthcare may contribute to substandard experiences with the healthcare system, increasing the burden of poor health in older adults. Few studies have focused on the presence of healthcare discrimination and its effects on older adults. We aimed to examine the relationship between healthcare discrimination and new or worsened disability. This was a longitudinal analysis of data from the nationally representative Health and Retirement Study administered in 2008 with follow-up through 2012. Six thousand and seventeen adults over the age of 50 years (mean age 67 years, 56.3 % female, 83.1 % white) were included in this study. Healthcare discrimination assessed by a 2008 report of receiving poorer service or treatment than other people by doctors or hospitals (never, less than a year=infrequent; more than once a year=frequent). Outcome was self-report of new or worsened disability by 2012 (difficulty or dependence in any of six activities of daily living). We used a Cox proportional hazards model adjusting for age, race/ethnicity, gender, net worth, education, depression, high blood pressure, diabetes, cancer, lung disease, heart disease, stroke, and healthcare utilization in the past 2 years. In all, 12.6 % experienced discrimination infrequently and 5.9 % frequently. Almost one-third of participants (29 %) reporting frequent healthcare discrimination developed new or worsened disability over 4 years, compared to 16.8 % of those who infrequently and 14.7 % of those who never experienced healthcare discrimination (p discrimination, frequent healthcare discrimination was associated with new or worsened disability over 4 years (aHR = 1.63, 95 % CI 1.16-2.27). One out of five adults over the age of 50 years experiences discrimination in healthcare settings. One in 17 experience frequent healthcare discrimination, and this is associated with new or worsened

Comparative psychophysics of bumblebee and honeybee colour discrimination and object detection.

Science.gov (United States)

Dyer, Adrian G; Spaethe, Johannes; Prack, Sabina

2008-07-01

Bumblebee (Bombus terrestris) discrimination of targets with broadband reflectance spectra was tested using simultaneous viewing conditions, enabling an accurate determination of the perceptual limit of colour discrimination excluding confounds from memory coding (experiment 1). The level of colour discrimination in bumblebees, and honeybees (Apis mellifera) (based upon previous observations), exceeds predictions of models considering receptor noise in the honeybee. Bumblebee and honeybee photoreceptors are similar in spectral shape and spacing, but bumblebees exhibit significantly poorer colour discrimination in behavioural tests, suggesting possible differences in spatial or temporal signal processing. Detection of stimuli in a Y-maze was evaluated for bumblebees (experiment 2) and honeybees (experiment 3). Honeybees detected stimuli containing both green-receptor-contrast and colour contrast at a visual angle of approximately 5 degrees , whilst stimuli that contained only colour contrast were only detected at a visual angle of 15 degrees . Bumblebees were able to detect these stimuli at a visual angle of 2.3 degrees and 2.7 degrees , respectively. A comparison of the experiments suggests a tradeoff between colour discrimination and colour detection in these two species, limited by the need to pool colour signals to overcome receptor noise. We discuss the colour processing differences and possible adaptations to specific ecological habitats.

Perceived discrimination is associated with health behaviours among African-Americans in the Jackson Heart Study.

Science.gov (United States)

Sims, Mario; Diez-Roux, Ana V; Gebreab, Samson Y; Brenner, Allison; Dubbert, Patricia; Wyatt, Sharon; Bruce, Marino; Hickson, DeMarc; Payne, Tom; Taylor, Herman

2016-02-01

Using Jackson Heart Study data, we examined associations of multiple measures of perceived discrimination with health behaviours among African-Americans (AA). The cross-sectional associations of everyday, lifetime and burden of discrimination with odds of smoking and mean differences in physical activity, dietary fat and sleep were examined among 4925 participants aged 35-84 years after adjustment for age and socioeconomic status (SES). Men reported slightly higher levels of everyday and lifetime discrimination than women and similar levels of burden of discrimination as women. After adjustment for age and SES, everyday discrimination was associated with more smoking and a greater percentage of dietary fat in men and women (OR for smoking: 1.13, 95% CI 1.00 to 1.28 and 1.19, 95% CI 1.05 to 1.34; mean difference in dietary fat: 0.37, pwomen, respectively). Everyday and lifetime discrimination were associated with fewer hours of sleep in men and women (mean difference for everyday discrimination: -0.08, pdiscrimination: -0.08, pdiscrimination was associated with more smoking and fewer hours of sleep in women only. Higher levels of perceived discrimination were associated with select health behaviours among men and women. Health behaviours offer a potential mechanism through which perceived discrimination affects health in AA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Does perceived discrimination affect health? Longitudinal relationships between work discrimination and women's physical and emotional health.

Science.gov (United States)

Pavalko, Eliza K; Mossakowski, Krysia N; Hamilton, Vanessa J

2003-03-01

This study uses longitudinal data to examine the causal relationships between perceived work discrimination and women's physical and emotional health. Using data on 1,778 employed women in the National Longitudinal Survey of Mature Women, we investigate the structural and individual characteristics that predict later perceptions of discrimination and the effects of those perceptions on subsequent health. We find that perceptions of discrimination are influenced by job attitudes, prior experiences of discrimination, and work contexts, but prior health is not related to later perceptions. However, perceptions of discrimination do impact subsequent health, and these effects remain significant after controlling for prior emotional health, physical health limitations, discrimination, and job characteristics. Overall, the results provide even stronger support for the health impact of workplace discrimination and suggest a need for further longitudinal analyses of causes and consequences of perceived discrimination.

Discrimination among adults with craniofacial conditions.

Science.gov (United States)

Roberts, Rachel M

2014-01-01

The primary goal of this study was to establish the level of perceived discrimination experienced by adults with congenital craniofacial conditions in Australia and to examine predictors of discrimination. Specifically, this study tested whether social support mediates the relationship between discrimination and health. Adults (n = 93) who had been treated at the Australian Craniofacial Unit, Women's and Children's Hospital, Adelaide for congenital craniofacial conditions (not including cleft lip and/or palate) completed questionnaires examining satisfaction with life, quality of life, anxiety and depression, self-esteem, satisfaction with social support, and satisfaction with appearance. A substantial minority of adults with congenital craniofacial conditions reported that they experience discrimination almost every day in a range of areas. Higher reports of discrimination were related to older age, being male, and less education. Other factors related to higher discrimination included lower levels of satisfaction with life, self-esteem, satisfaction with appearance and mental quality of life, as well as higher levels of anxiety and depression. Social support partially mediated the relationship between discrimination and mental health outcomes. The current study shows that discrimination experiences continue into adulthood confirming the importance of ensuring patients are well supported both by psychosocial services as well as within their own social support networks.

Perceived weight discrimination and chronic biochemical stress: A population-based study using cortisol in scalp hair.

Science.gov (United States)

Jackson, Sarah E; Kirschbaum, Clemens; Steptoe, Andrew

2016-12-01

There is increasing evidence for weight-based discrimination against persons with obesity. This study aimed to examine the physiological impact of perceived weight discrimination on cortisol in hair, an indicator of chronic stress exposure. Data were from 563 nonsmoking individuals with obesity (body mass index, BMI ≥30 kg/m 2 ) participating in the English Longitudinal Study of Ageing. Experiences of discrimination were reported via questionnaire, and hair cortisol concentrations were determined from the scalp-nearest 2-cm hair segment. Height and weight were objectively measured. ANCOVAs tested associations between perceived weight discrimination and hair cortisol concentration overall and by degree of obesity. All analyses were adjusted for age, sex, ethnicity, socioeconomic status, and BMI. Mean hair cortisol concentrations were 33% higher in those who had experienced weight discrimination than those who had not (mean log pg/mg 1.241 vs. 0.933, F = 12.01, P = 0.001). The association between weight discrimination and hair cortisol was particularly pronounced in individuals with severe (class II/III) obesity (1.402 vs. 0.972, F = 11.58, P = 0.001). Weight discrimination is associated with the experience of stress at a biological level. Chronic exposure to elevated levels of cortisol may play a role in generating a vicious circle of weight gain and discrimination and contribute to obesity-associated health conditions. © 2016 The Authors. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Racial/Ethnic Workplace Discrimination

Science.gov (United States)

Chavez, Laura J.; Ornelas, India J.; Lyles, Courtney R.; Williams, Emily C.

2014-01-01

Background Experiences of discrimination are associated with tobacco and alcohol use, and work is a common setting where individuals experience racial/ethnic discrimination. Few studies have evaluated the association between workplace discrimination and these behaviors, and none have described associations across race/ethnicity. Purpose To examine the association between workplace discrimination and tobacco and alcohol use in a large, multistate sample of U.S. adult respondents to the Behavioral Risk Factor Surveillance System survey Reactions to Race Module (2004–2010). Methods Multivariable logistic regression analyses evaluated cross-sectional associations between self-reported workplace discrimination and tobacco (current and daily smoking) and alcohol use (any and heavy use, and binge drinking) among all participants and stratified by race/ethnicity, adjusting for relevant covariates. Data were analyzed in 2013. Results Among respondents, 70,080 completed the workplace discrimination measure. Discrimination was more common among black non-Hispanic (21%), Hispanic (12%), and other race respondents (11%) than white non-Hispanics (4%) (pdiscrimination was associated with current smoking (risk ratio [RR]=1.32, 95% CI=1.19, 1.47), daily smoking (RR=1.41, 95% CI=1.24, 1.61), and heavy drinking (RR=1.11, 95% CI=1.01, 1.22), but not binge or any drinking. Among Hispanics, workplace discrimination was associated with increased heavy and binge drinking, but not any alcohol use or smoking. Workplace discrimination among black non-Hispanics and white Non-Hispanics was associated with increased current and daily smoking, but not alcohol outcomes. Conclusions Workplace discrimination is common, associated with smoking and alcohol use, and merits further policy attention given the impact of these behaviors on morbidity and mortality. PMID:25441232

Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers.

Science.gov (United States)

Wang, Chun-Neng; Hsu, Hao-Chun; Wang, Cheng-Chun; Lee, Tzu-Kuei; Kuo, Yan-Fu

2015-01-01

The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D) images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D) images by using microcomputed tomography (μCT) and to examine the floral shape variations by using geometric morphometrics (GM). To demonstrate the advantages of the 3D-μCT-GM approach, we applied the approach to a second-generation population of florist's gloxinia (Sinningia speciosa) crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks) from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-μCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations.

Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers

Directory of Open Access Journals (Sweden)

Chun-Neng eWang

2015-09-01

Full Text Available The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D images by using microcomputed tomography (μCT and to examine the floral shape variations by using geometric morphometrics (GM. To demonstrate the advantages of the 3D-µCT-GM approach, we applied the approach to a second-generation population of florist’s gloxinia (Sinningia speciosa crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-µCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations.

Electronic methods for discriminating scintillation shapes; Methodes electroniques de discrimination des formes des impulsions issues de scintillateurs; Ehlektronnye metody diskriminatsii form stsintillyatsii; Metodos electronicos de discriminacion de forma de impulsos de centelleo

Energy Technology Data Exchange (ETDEWEB)

Forte, M; Konsta, A; Maranzana, C [European Atomic Energy Community, CCR, ISPRA (Italy)

1962-04-15

As reported previously, the scintillation pulse shape, which is characteristic of the excitating particle type (electron, proton, alpha, etc.), can be converted into a pulse-height independent parameter. This displays, by means of a multichannel analyser, the composition of a mixed particle beam which excites the scintillator. This method was successful with several scintillators, both of the organic and the inorganic type. Details are given of the electronic techniques used for converting the pulse shapes. For the simpler case of discrimination between only two classes of pulses (e.g. neutron-gamma discrimination) the use of passive networks has also been considered possible for further improvements and simplifications. A few networks were tried, the main results being that, in the presence of gamma background, the discrimination of recoil protons in liquid scintillators was extended to small pulses of a few decades of photoelectrons and the discrimination of neutron-capture fragments in boronloaded liquids was obtained. Some of these networks operated with pulses of the same polarity, from two of the last dynode, or even with the output from a single electrode. This may be useful when it is convenient to use the anode independently, e. g. for operating fast time circuits. (author) [French] On sait que la forme des impulsions delivrees par un detecteur a scintillations, qui est fonction du type de particule excitatrice (electron, proton, particule alpha, etc.), peut etre convertie en un parametre d'amplitude d'impulsion independant. Cette propriete permet de determiner, a l'aide d'un selecteur multicanaux, la composition d'un faisceau de particules mixte qui frappe le scintillateur. Cette methode a ete utilisee avec succes dans le cas de plusieurs scintillateurs, tant organiques qu'inorganiques. Les auteurs donnent des precisions sur les procedes electroniques employes pour convertir la forme de l'impulsion. Dans le cas le plus simple, celui ou la discrimination

An in situ neutron diffraction study of shape setting shape memory NiTi

International Nuclear Information System (INIS)

Benafan, O.; Padula, S.A.; Noebe, R.D.; Brown, D.W.; Clausen, B.; Vaidyanathan, R.

2013-01-01

A bulk polycrystalline Ni 49.9 Ti 50.1 (at.%) shape memory alloy specimen was shape set while neutron diffraction spectra were simultaneously acquired. The objective was to correlate internal stress, phase volume fraction, and texture measurements (from neutron diffraction spectra) with the macroscopic stress and shape changes (from load cell and extensometry measurements) during the shape setting procedure and subsequent shape recovery. Experimental results showed the evolution of the martensitic transformation (lattice strains, phase fractions and texture) against external constraints during both heating and cooling. Constrained heating resulted in a build-up of stresses during the martensite to austenite transformation, followed by stress relaxation due to thermal expansion, final conversion of retained martensite, and recovery processes. Constrained cooling also resulted in stress build-up arising from thermal contraction and early formation of martensite, followed by relaxation as the austenite fully transformed to martensite. Comparisons were also made between specimens pre-shape set and post-shape set with and without external constraints. The specimens displayed similar shape memory behavior consistent with the microstructure of the shape set sample, which was mostly unchanged by the shape setting process and similar to that of the as-received material

Digital pulse-shape analyzer based on fast sampling of an integrated charge pulse

International Nuclear Information System (INIS)

Jordanov, V.T.; Knoll, G.F.

1995-01-01

A novel configuration for pulse-shape analysis and discrimination has been developed. The current pulse from detector is sent to a gated integrator and then sampled by a flash analog-to-digital converter (ADC). The sampled data are processed digitally, thus allowing implementation of a near-optimum weighting function and elimination some of the instabilities associated with the gated integrator. The analyzer incorporates pileup rejection circuit that reduces the pileup effects at high counting rates. The system was tested liquid scintillator. Figures of merit for neutron-gamma pulse-shape discrimination were found to be: 0.78 for 25 keV (electron equivalent energy) and 3.5 for 500 keV. The technique described in this paper was developed to be used in a near tissue-equivalent neutron-gamma dosimeter which employs a liquid scintillator detector

Discrimination and delusional ideation

NARCIS (Netherlands)

Janssen, I.C.M.; Hanssen, M.S.S.; Bak, M.L.F.J.; Bijl, R.V.; Graaf, R. de; Vollebergh, W.A.M.; McKenzie, K.; Os, J. van

2003-01-01

Background In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. Aims To test whether perceived discrimination is associated longitudinally with onset of psychosis. Method A 3-year prospective study of cohorts with no history of psychosis and

Measuring HIV- and AIDS-related stigma and discrimination in Nicaragua: results from a community-based study.

Science.gov (United States)

Ugarte, William J; Högberg, Ulf; Valladares, Eliette C; Essén, Birgitta

2013-04-01

Psychometric properties of external HIV-related stigma and discrimination scales and their predictors were investigated. A cross-sectional community-based study was carried out among 520 participants using an ongoing health and demographic surveillance system in León, Nicaragua. Participants completed an 18-item HIV stigma scale and 19 HIV and AIDS discrimination-related statements. A factor analysis found that 15 of the 18 items in the stigma scale and 18 of the 19 items in the discrimination scale loaded clearly into five- and four-factor structures, respectively. Overall Cronbach's alpha of .81 for the HIV stigma scale and .91 for the HIV discrimination scale provided evidence of internal consistency. Hierarchical multiple linear regression analysis identified that females, rural residents, people with insufficient HIV-related transmission knowledge, those not tested for HIV, those reporting an elevated self-perception of HIV risk, and those unwilling to disclose their HIV status were associated with higher stigmatizing attitudes and higher discriminatory actions towards HIV-positive people. This is the first community-based study in Nicaragua that demonstrates that overall HIV stigma and discrimination scales were reliable and valid in a community-based sample comprised of men and women of reproductive age. Stigma and discrimination were reported high in the general population, especially among sub-groups. The findings in the current study suggest community-based strategies, including the monitoring of stigma and discrimination, and designing and implementing stigma reduction interventions, are greatly needed to reduce inequities and increase acceptance of persons with HIV.

Discrimination of Breast Tumors in Ultrasonic Images by Classifier Ensemble Trained with AdaBoost

Science.gov (United States)

Takemura, Atsushi; Shimizu, Akinobu; Hamamoto, Kazuhiko

In this paper, we propose a novel method for acurate automated discrimination of breast tumors (carcinoma, fibroadenoma, and cyst). We defined 199 features related to diagnositic observations noticed when a doctor judges breast tumors, such as internal echo, shape, and boundary echo. These features included novel features based on a parameter of log-compressed K distribution, which reflect physical characteristics of ultrasonic B-mode imaging. Furthermore, we propose a discrimination method of breast tumors by using an ensemble classifier based on the multi-class AdaBoost algorithm with effective features selection. Verification by analyzing 200 carcinomas, 30 fibroadenomas and 30 cycts showed the usefulness of the newly defined features and the effectiveness of the discrimination by using an ensemble classifier trained by AdaBoost.

THE JURIDICAL PROTECTION ON GLOBAL DISCRIMINATION

Directory of Open Access Journals (Sweden)

CRISTINA OTOVESCU FRĂSIE

2012-05-01

Full Text Available In this study I wished to evidence the main juridical documents referring to discrimination, adopted world wide by the United Nations Organization. Thus, can be identified several types of definitions concerning the discrimination against women, the race discrimination, the torture etc. within the analyzed documents. The democratic countries have laws that punish the discrimination, but, unfortunately, there are discrimination phenomena for example regarding the ethnicity, the gender, the language, the convictions, the age, at the working place, inside the family etc.

From general discrimination to segmented inequality: Migration and inequality in urban China.

Science.gov (United States)

Lu, Yao; Wang, Feng

2013-11-01

Internal migration in China during the last three decades, the largest in human history, offers a rare opportunity to understand inequalities in the making. Using data spanning 10years from China's largest metropolis, Shanghai, this study assesses how enduring state institutions interplay with the spread of market forces to shape income inequality between migrants and native urban workers. Though the wages of both Chinese migrants and urban workers rose considerably, economic restructuring during the decade under study resulted in diminished privileges for urbanites and subsequently increased collision between migrants and urban workers in the private sectors. These shifts, rather than substantially reducing inequality, have led to an evolving form of inequality, from an initial general blatant discrimination against migrants across the board, to a new and more subtle form of inequality characterized by substantial segmented discrimination against migrants within economic sectors, with the degree of inequality varying from sector to sector. We discuss how this changing inequality reflects complementary rather than competing roles of the state and market institutions in inequality creation and maintenance. Copyright © 2013 Elsevier Inc. All rights reserved.

From discrimination to internalized mental illness stigma: The mediating roles of anticipated discrimination and anticipated stigma.

Science.gov (United States)

Quinn, Diane M; Williams, Michelle K; Weisz, Bradley M

2015-06-01

Internalizing mental illness stigma is related to poorer well-being, but less is known about the factors that predict levels of internalized stigma. This study explored how experiences of discrimination relate to greater anticipation of discrimination and devaluation in the future and how anticipation of stigma in turn predicts greater stigma internalization. Participants were 105 adults with mental illness who self-reported their experiences of discrimination based on their mental illness, their anticipation of discrimination and social devaluation from others in the future, and their level of internalized stigma. Participants were approached in several locations and completed surveys on laptop computers. Correlational analyses indicated that more experiences of discrimination due to one's mental illness were related to increased anticipated discrimination in the future, increased anticipated social stigma from others, and greater internalized stigma. Multiple serial mediator analyses showed that the effect of experiences of discrimination on internalized stigma was fully mediated by increased anticipated discrimination and anticipated stigma. Experiences of discrimination over one's lifetime may influence not only how much future discrimination people with mental illness are concerned with but also how much they internalize negative feelings about the self. Mental health professionals may need to address concerns with future discrimination and devaluation in order to decrease internalized stigma. (c) 2015 APA, all rights reserved).

Attentional modulation of neural processing of shape, color, and velocity in humans

International Nuclear Information System (INIS)

Corbetta, M.; Miezin, F.M.; Dobmeyer, S.; Shulman, G.L.; Petersen, S.E.

1990-01-01

Positron emission tomography (PET) was used to measure changes in regional cerebral blood flow of normal subjects, while they were discriminating different attributes (shape, color, and velocity) of the same set of visual stimuli. Psychophysical evidence indicated that the sensitivity for discriminating subtle stimulus changes was higher when subjects focused attention on one attribute than when they divided attention among several attributes. Correspondingly, attention enhanced the activity of different regions of extrastriate visual cortex that appear to be specialized for processing information related to the selected attribute

Deep Correlated Holistic Metric Learning for Sketch-Based 3D Shape Retrieval.

Science.gov (United States)

Dai, Guoxian; Xie, Jin; Fang, Yi

2018-07-01

How to effectively retrieve desired 3D models with simple queries is a long-standing problem in computer vision community. The model-based approach is quite straightforward but nontrivial, since people could not always have the desired 3D query model available by side. Recently, large amounts of wide-screen electronic devices are prevail in our daily lives, which makes the sketch-based 3D shape retrieval a promising candidate due to its simpleness and efficiency. The main challenge of sketch-based approach is the huge modality gap between sketch and 3D shape. In this paper, we proposed a novel deep correlated holistic metric learning (DCHML) method to mitigate the discrepancy between sketch and 3D shape domains. The proposed DCHML trains two distinct deep neural networks (one for each domain) jointly, which learns two deep nonlinear transformations to map features from both domains into a new feature space. The proposed loss, including discriminative loss and correlation loss, aims to increase the discrimination of features within each domain as well as the correlation between different domains. In the new feature space, the discriminative loss minimizes the intra-class distance of the deep transformed features and maximizes the inter-class distance of the deep transformed features to a large margin within each domain, while the correlation loss focused on mitigating the distribution discrepancy across different domains. Different from existing deep metric learning methods only with loss at the output layer, our proposed DCHML is trained with loss at both hidden layer and output layer to further improve the performance by encouraging features in the hidden layer also with desired properties. Our proposed method is evaluated on three benchmarks, including 3D Shape Retrieval Contest 2013, 2014, and 2016 benchmarks, and the experimental results demonstrate the superiority of our proposed method over the state-of-the-art methods.

Neutron/gamma discrimination employing the power spectrum analysis of the signal from the liquid scintillator BC501A

International Nuclear Information System (INIS)

Luo, X.L.; Wang, Y.K; Yang, J.; Liu, G.; Lin, C.B.; Hu, Q.Q.; Peng, J.X.

2013-01-01

A digital method for the discrimination of neutron and γ-ray events based on analyzing the power spectra of the signals from a BC501A liquid scintillator detector was presented and investigated in this paper. In order to evaluate the feasibility of this novel pulse shape discrimination method, a 5GSample/s 8-bit oscilloscope was used to acquire waveforms for n/γ discrimination. Furthermore, the performance of this novel n/γ discrimination method was compared with that of a widely used method called the reference-pulses method which averaged a large number of neutron and γ-ray pulses to obtain the reference-pulse as the criterion for n/γ discrimination. The results showed that the proposed method performed well over the reference-pulses method, which was verified by the considerable decrease in the error rate of n/γ discrimination and the improvement of the Figure of Merit

"Discrimination", the Main Concern of Iranian Nurses over Inter-Professional Collaboration: an Explorative Qualitative Study.

Science.gov (United States)

Valizadeh, Leila; Zamanzadeh, Vahid; Irajpour, Alireza; Shohani, Masoumeh

2015-06-01

People in various professions may face discrimination. In the nursing field, discrimination among nurses in the workplace, regardless of race, gender or religion have not been studied; a problem that leads to a reduction in the quality of nursing care and nurse turnover. Discovery of the concerns of nurses about inter-professional collaboration is the purpose of this study. The present study is conducted by using a qualitative content analysis. The data collection process included 22 unstructured and in-depth interviews with nurses between April 2012 and February 2013 in the medical teaching centers of Iran. A purposive sampling method was used. All interviews were recorded, typed, and analyzed simultaneously. The category obtained from explaining nurses' experiences of inter-professional collaboration was "discrimination" that included two subcategories, namely (1) lack of perspective towards equality in authorities, and (2) professional respect and value deficit. Nurses' experiences are indicating their perception of discrimination that influences the collaboration between nurses, which should be taken into account by managers. The findings of the present study help to managers about decision making on how to deal with staff and can be helpful in preventing nurse turnover and providing better services by nurses.

Relationship of race-, sexual orientation-, and HIV-related discrimination with adherence to HIV treatment: a pilot study.

Science.gov (United States)

Boarts, Jessica M; Bogart, Laura M; Tabak, Melanie A; Armelie, Aaron P; Delahanty, Douglas L

2008-10-01

Adherence to highly active antiretroviral therapy (HAART) must be close to perfect in order to maintain suppression of HIV viral load, and to prevent the development of drug resistant strains of HIV. People living with HIV (PLWH) often report low levels of adherence. One variable that has been linked to poor adherence is perceived discrimination; however, research has generally not considered the possible unique effects of different types of discrimination on adherence. The present pilot study aimed to examine the association of three types of discrimination (due to HIV+ status, race, or sexual orientation) with adherence among 57 PLWH. Logistic regression analyses were conducted to demonstrate the relationships between each type of discrimination and self-reported adherence. Racial discrimination significantly predicted lower adherence levels, whereas sexual orientation- and HIV-related discrimination did not. Results underscore the importance of addressing discrimination issues, specifically racial, when designing interventions to improve adherence to HAART.

Experienced discrimination amongst European old citizens

NARCIS (Netherlands)

van den Heuvel, Wim J. A.; van Santvoort, Marc M.

2011-01-01

This study analyses the experienced age discrimination of old European citizens and the factors related to this discrimination. Differences in experienced discrimination between old citizens of different European countries are explored. Data from the 2008 ESS survey are used. Old age is defined as

Need for Studies of Sex Discrimination in Public Schools. Revised.

Science.gov (United States)

Citizens Advisory Council on the Status of Women, Washington, DC.

This memorandum reviews the need for studies on sex discrimination in public schools and suggests groups that should make local reviews and those areas which need reviewing -- one sex schools; one sex or practically one sex courses; physical education, sports, and other extracurricular activities; textbooks, library books, and other curricular…

Random, double- and single-strand DNA breaks can be differentiated in the method of Comet assay by the shape of the comet image.

Science.gov (United States)

Georgieva, Milena; Zagorchev, Plamen; Miloshev, George

2015-10-01

Comet assay is an invaluable tool in DNA research. It is widely used to detect DNA damage as an indicator of exposure to genotoxic stress. A canonical set of parameters and specialized software programs exist for Comet assay data quantification and analysis. None of them so far has proven its potential to employ a computer-based algorithm for assessment of the shape of the comet as an indicator of the exact mechanism by which the studied genotoxins cut in the molecule of DNA. Here, we present 14 unique measurements of the comet image based on the comet morphology. Their mathematical derivation and statistical analysis allowed precise description of the shape of the comet image which in turn discriminated the cause of genotoxic stress. This algorithm led to the development of the "CometShape" software which allowed easy discrimination among different genotoxins depending on the type of DNA damage they induce. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Children's perceptions of gender discrimination.

Science.gov (United States)

Spears Brown, Christia; Bigler, Rebecca S

2004-09-01

Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the gender of the perpetrator (i.e., teacher) were manipulated. Results indicated that older children were more likely than younger children to make attributions to discrimination when contextual information suggested that it was likely. Girls (but not boys) were more likely to view girls than boys as victims of discrimination, and children with egalitarian gender attitudes were more likely to perceive discrimination than were their peers. Copyright 2004 American Psychological Association

Discrimination methods between neutron and gamma rays for boron loaded plastic scintillators

CERN Document Server

Normand, S; Haan, S; Louvel, M

2002-01-01

Boron loaded plastic scintillators exhibit interesting properties for neutron detection in nuclear waste management and especially in investigating the amount of fissile materials when enclosed in waste containers. Combining a high thermal neutron efficiency and a low mean neutron lifetime, they are suitable in neutron multiplicity counting. However, due to their high sensitivity to gamma rays, pulse shape discrimination methods need to be developed in order to optimize the passive neutron assay measurement. From the knowledge of their physical properties, it is possible to separate the three kinds of particles that have interacted in the boron loaded plastic scintillator (gamma, fast neutron and thermal neutron). For this purpose, we have developed and compared the two well known discrimination methods (zero crossing and charge comparison) applied for the first time to boron loaded plastic scintillator. The setup for the zero crossing discrimination method and the charge comparison methods is thoroughly expl...

Simple ways of n-γ discrimination using charge comparison technique

International Nuclear Information System (INIS)

Jhingan, Akhil; Singh, Hardev; Singh, R.P.; Golda, K.S.; Sugathan, P.; Mandal, S.; Bhowmik, R.K.

2008-01-01

The charge comparison method for n-γ discrimination has been in practice for more than two decades; technically it can be implemented in variety of ways. We present explicitly, in detail, two simple ways of implementing this technique. The first one is the conventional way of comparing the fractional or slow charge in the tail with the full charge of photomultiplier tubes (PMTs) anode pulse fed to a charge integrating ADC or QDC, but has been electronically implemented in a new fashion. The second one is a novel technique of comparing shaped-dynode pulse, fed to a peak-sensing ADC, with the fractional slow charge integrated in QDC. This technique reduces the complexity of individual gate generation, and thus reduces the number of gate and delay generators, compared with the first case. To implement these techniques, we have designed and fabricated a six-channel, single-width NIM module for use with QDC for n-γ discrimination. The module fabrication is very simple and inexpensive, and can be easily integrated with commercially available high-density NIM and CAMAC modules in experimental setups involving a large number of neutron detectors. Commercially available passive analog delay line chips have been used for delaying analog signals fed to the QDC. To simplify the setup for high-density applications we have replaced the constant fraction discriminator (CFD) by a fast leading-edge discriminator. The quality of n-γ discrimination obtained is comparable with that reported earlier in the literature

Colour and shape analysis techniques for weed detection in cereal fields

DEFF Research Database (Denmark)

Pérez, A.J; López, F; Benlloch, J.V.

2000-01-01

. The proposed methods use colour information to discriminate between vegetation and background, whilst shape analysis techniques are applied to distinguish between crop and weeds. The determination of crop row position helps to reduce the number of objects to which shape analysis techniques are applied....... The performance of algorithms was assessed by comparing the results with a human classification, providing an acceptable success rate. The study has shown that despite the difficulties in accurately determining the number of seedlings (as in visual surveys), it is feasible to use image processing techniques......Information on weed distribution within the field is necessary to implement spatially variable herbicide application. This paper deals with the development of near-ground image capture and processing techniques in order to detect broad-leaved weeds in cereal crops under actual field conditions...

Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning.

Science.gov (United States)

Guo, Yanrong; Gao, Yaozong; Shao, Yeqin; Price, True; Oto, Aytekin; Shen, Dinggang

2014-07-01

Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on different patches of the

Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

Science.gov (United States)

Guo, Yanrong; Gao, Yaozong; Shao, Yeqin; Price, True; Oto, Aytekin; Shen, Dinggang

2014-01-01

Purpose: Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. Methods: To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on different

Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

International Nuclear Information System (INIS)

Guo, Yanrong; Shao, Yeqin; Gao, Yaozong; Price, True; Oto, Aytekin; Shen, Dinggang

2014-01-01

Purpose: Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. Methods: To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on

Deformable segmentation of 3D MR prostate images via distributed discriminative dictionary and ensemble learning

Energy Technology Data Exchange (ETDEWEB)

Guo, Yanrong; Shao, Yeqin [Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina 27599 (United States); Gao, Yaozong; Price, True [Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina 27599 and Department of Computer Science, University of North Carolina at Chapel Hill, North Carolina 27599 (United States); Oto, Aytekin [Department of Radiology, Section of Urology, University of Chicago, Illinois 60637 (United States); Shen, Dinggang, E-mail: dgshen@med.unc.edu [Department of Radiology and BRIC, University of North Carolina at Chapel Hill, North Carolina 27599 and Department of Brain and Cognitive Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2014-07-15

Purpose: Automatic prostate segmentation from MR images is an important task in various clinical applications such as prostate cancer staging and MR-guided radiotherapy planning. However, the large appearance and shape variations of the prostate in MR images make the segmentation problem difficult to solve. Traditional Active Shape/Appearance Model (ASM/AAM) has limited accuracy on this problem, since its basic assumption, i.e., both shape and appearance of the targeted organ follow Gaussian distributions, is invalid in prostate MR images. To this end, the authors propose a sparse dictionary learning method to model the image appearance in a nonparametric fashion and further integrate the appearance model into a deformable segmentation framework for prostate MR segmentation. Methods: To drive the deformable model for prostate segmentation, the authors propose nonparametric appearance and shape models. The nonparametric appearance model is based on a novel dictionary learning method, namely distributed discriminative dictionary (DDD) learning, which is able to capture fine distinctions in image appearance. To increase the differential power of traditional dictionary-based classification methods, the authors' DDD learning approach takes three strategies. First, two dictionaries for prostate and nonprostate tissues are built, respectively, using the discriminative features obtained from minimum redundancy maximum relevance feature selection. Second, linear discriminant analysis is employed as a linear classifier to boost the optimal separation between prostate and nonprostate tissues, based on the representation residuals from sparse representation. Third, to enhance the robustness of the authors' classification method, multiple local dictionaries are learned for local regions along the prostate boundary (each with small appearance variations), instead of learning one global classifier for the entire prostate. These discriminative dictionaries are located on

Workplace discrimination: experiences of practicing physicians.

Science.gov (United States)

Coombs, Alice A Tolbert; King, Roderick K

2005-04-01

In response to a growing concern regarding physician discrimination in the workplace, this study was developed to: (1) describe the types of discrimination that exist for the practicing physician and (2) determine which groups of physicians are more likely to experience the various forms of discrimination. Surveys were mailed to 1930 practicing physicians in Massachusetts. Participants were asked if they had encountered discrimination, how significant the discrimination was against a specific group, the frequency of personal discrimination, and the type of discrimination. Factor analysis identified four types of discrimination: career advancement, punitive behaviors, practice barriers and hiring barriers. A total of 445 responses were received (a 24% response rate). Sixty-three percent of responding physicians had experienced some form of discrimination. Respondents were women (46%), racial/ethnic minorities (42%) and international medical graduates (IMGs) (40%). In addition, 26% of those classified as white were also IMGs. Over 60% of respondents believed discrimination against IMGs was very or somewhat significant. Almost 27% of males acknowledged that gender bias against females was very or somewhat significant. IMGs were more likely to indicate that discrimination against IMGs was significant in their current organization. Of U.S. medical graduates (USMGs) 44% reported that discrimination against IMGs in their current organization was significant. Nonwhites were more likely to report that discrimination based on race/ethnicity was significant. Nearly 29% of white respondents also believed that such discrimination was very or somewhat significant. Physicians practicing in academic, research, and private practice sectors experience discrimination based on gender, ethnic/racial, and IMG status.

Application of Phase Congruency for Discriminating Some Lung Diseases Using Chest Radiograph

Directory of Open Access Journals (Sweden)

Omar Mohd Rijal

2015-01-01

Full Text Available A novel procedure using phase congruency is proposed for discriminating some lung disease using chest radiograph. Phase congruency provides information about transitions between adjacent pixels. Abrupt changes of phase congruency values between pixels may suggest a possible boundary or another feature that may be used for discrimination. This property of phase congruency may have potential for deciding between disease present and disease absent where the regions of infection on the images have no obvious shape, size, or configuration. Five texture measures calculated from phase congruency and Gabor were shown to be normally distributed. This gave good indicators of discrimination errors in the form of the probability of Type I Error (δ and the probability of Type II Error (β. However, since 1 −  δ is the true positive fraction (TPF and β is the false positive fraction (FPF, an ROC analysis was used to decide on the choice of texture measures. Given that features are normally distributed, for the discrimination between disease present and disease absent, energy, contrast, and homogeneity from phase congruency gave better results compared to those using Gabor. Similarly, for the more difficult problem of discriminating lobar pneumonia and lung cancer, entropy and homogeneity from phase congruency gave better results relative to Gabor.

The role of mastery in the relationship between perceived ethnic discrimination and depression: The HELIUS study.

Science.gov (United States)

Slotman, Anne; Snijder, Marieke B; Ikram, Umar Z; Schene, Aart H; Stevens, Gonneke W J M

2017-04-01

This study examined the mediating and moderating role of one's sense of mastery in the relationship between perceived ethnic discrimination and depression. Questionnaire data from participants of the Healthy Life in an Urban Setting (HELIUS) study were used, containing responses from 9,141 Surinamese, Turkish, Moroccan, and Ghanaian immigrant adults, aged 18 to 70, living in Amsterdam, the Netherlands. Results of path modeling indicated that perceptions of ethnic discrimination were positively related to depression symptomatology, and this relationship was moderated and partially mediated by mastery. Results remained fairly robust across sex, educational level, immigrant generation, and ethnicity. This study indicated that mastery may both serve a moderating and mediating role in the relationship between perceived ethnic discrimination and depression, suggestive of a process in which the impact of perceiving discrimination becomes increasingly more deteriorating over time. Thus, interventions focused on mastery may potentially be beneficial to improve ethnic minority mental health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

From Discrimination to Internalized Mental Illness Stigma: The Mediating Roles of Anticipated Discrimination and Anticipated Stigma

Science.gov (United States)

Quinn, Diane M.; Williams, Michelle K.; Weisz, Bradley M.

2015-01-01

Objective Internalizing mental illness stigma is related to poorer well-being, but less is known about the factors that predict levels of internalized stigma. This study explored how experiences of discrimination relate to greater anticipation of discrimination and devaluation in the future, and how anticipation of stigma, in turn predicts greater stigma internalization. Method Participants were 105 adults with mental illness who self-reported their experiences of discrimination based on their mental illness, their anticipation of discrimination and social devaluation from others in the future, and their level of internalized stigma. Participants were approached in several locations and completed surveys on laptop computers. Results Correlational analyses indicated that more experiences of discrimination due to one’s mental illness were related to increased anticipated discrimination in the future, increased anticipated social stigma from others, and greater internalized stigma. Multiple serial mediator analyses showed that the effect of experiences of discrimination on internalized stigma was fully mediated by increased anticipated discrimination and anticipated stigma. Conclusion and Implications for Practice Experiences of discrimination over the lifetime may influence not only how much future discrimination people with mental illness are concerned with but also how much they internalize negative feelings about the self. Mental health professionals may need to address concerns with future discrimination and devaluation in order to decrease internalized stigma. PMID:25844910

Large number discrimination by mosquitofish.

Directory of Open Access Journals (Sweden)

Christian Agrillo

Full Text Available BACKGROUND: Recent studies have demonstrated that fish display rudimentary numerical abilities similar to those observed in mammals and birds. The mechanisms underlying the discrimination of small quantities (<4 were recently investigated while, to date, no study has examined the discrimination of large numerosities in fish. METHODOLOGY/PRINCIPAL FINDINGS: Subjects were trained to discriminate between two sets of small geometric figures using social reinforcement. In the first experiment mosquitofish were required to discriminate 4 from 8 objects with or without experimental control of the continuous variables that co-vary with number (area, space, density, total luminance. Results showed that fish can use the sole numerical information to compare quantities but that they preferentially use cumulative surface area as a proxy of the number when this information is available. A second experiment investigated the influence of the total number of elements to discriminate large quantities. Fish proved to be able to discriminate up to 100 vs. 200 objects, without showing any significant decrease in accuracy compared with the 4 vs. 8 discrimination. The third experiment investigated the influence of the ratio between the numerosities. Performance was found to decrease when decreasing the numerical distance. Fish were able to discriminate numbers when ratios were 1:2 or 2:3 but not when the ratio was 3:4. The performance of a sample of undergraduate students, tested non-verbally using the same sets of stimuli, largely overlapped that of fish. CONCLUSIONS/SIGNIFICANCE: Fish are able to use pure numerical information when discriminating between quantities larger than 4 units. As observed in human and non-human primates, the numerical system of fish appears to have virtually no upper limit while the numerical ratio has a clear effect on performance. These similarities further reinforce the view of a common origin of non-verbal numerical systems in all

Spike detection, characterization, and discrimination using feature analysis software written in LabVIEW.

Science.gov (United States)

Stewart, C M; Newlands, S D; Perachio, A A

2004-12-01

Rapid and accurate discrimination of single units from extracellular recordings is a fundamental process for the analysis and interpretation of electrophysiological recordings. We present an algorithm that performs detection, characterization, discrimination, and analysis of action potentials from extracellular recording sessions. The program was entirely written in LabVIEW (National Instruments), and requires no external hardware devices or a priori information about action potential shapes. Waveform events are detected by scanning the digital record for voltages that exceed a user-adjustable trigger. Detected events are characterized to determine nine different time and voltage levels for each event. Various algebraic combinations of these waveform features are used as axis choices for 2-D Cartesian plots of events. The user selects axis choices that generate distinct clusters. Multiple clusters may be defined as action potentials by manually generating boundaries of arbitrary shape. Events defined as action potentials are validated by visual inspection of overlain waveforms. Stimulus-response relationships may be identified by selecting any recorded channel for comparison to continuous and average cycle histograms of binned unit data. The algorithm includes novel aspects of feature analysis and acquisition, including higher acquisition rates for electrophysiological data compared to other channels. The program confirms that electrophysiological data may be discriminated with high-speed and efficiency using algebraic combinations of waveform features derived from high-speed digital records.

Perceived discrimination among men and women with normal weight and obesity. A population-based study from Sweden.

Science.gov (United States)

Hansson, Lena M; Näslund, Erik; Rasmussen, Finn

2010-08-01

We examined whether men and women with obesity reported different types of discrimination to a greater extent than those with normal weight, and explored whether these associations were modified by socioeconomic position. National representative sample of men and women, with normal weight (n = 2,000), moderate obesity (n = 2,461) and severe obesity (n = 557). Participants were identified in a yearly population-based survey (1996-2006) and data on perceived discrimination and potential confounding factors were measured in 2008. Logistic regression models tested whether obesity was associated with perceived lifetime, workplace, healthcare and interpersonal discrimination. The overall response rate was 56%. For men, moderate obesity was associated with workplace discrimination, while severely obese women were more likely to report this sort of discrimination than normal weight women. Severely obese individuals were twice as likely to report healthcare discrimination than normal weight individuals. Women, regardless of weight status group, were in turn twice as likely to report healthcare discrimination as men. Women with severe obesity were significantly more likely to report interpersonal discrimination compared with normal weight women. Socioeconomic position modified the association between weight status and healthcare discrimination. Highly educated individuals with moderate and severe obesity were more likely to report healthcare discrimination than their normal weight counterparts, whereas low educated individuals with normal weight, moderate and severe obesity were equally likely to report discrimination. In this large, population-based study, discrimination was more likely to be reported by obese individuals compared with those of normal weight. The associations, however, varied according to gender and socioeconomic position.

Unravelling fears of genetic discrimination: an exploratory study of Dutch HCM families in an era of genetic non-discrimination acts

NARCIS (Netherlands)

Geelen, E.; Horstman, K.; Marcelis, C.L.; Doevendans, P.A.; Van Hoyweghen, I.

2012-01-01

Since the 1990s, many countries in Europe and the United States have enacted genetic non-discrimination legislation to prevent people from deferring genetic tests for fear that insurers or employers would discriminate against them based on that information. Although evidence for genetic

Pulse duration discriminator

International Nuclear Information System (INIS)

Kosakovskij, L.F.

1980-01-01

Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

Multichannel Discriminative Detection of Explosive Vapors with an Array of Nanofibrous Membranes Loaded with Quantum Dots

Directory of Open Access Journals (Sweden)

Zhaofeng Wu

2017-11-01

Full Text Available The multichannel fluorescent sensor array based on nanofibrous membranes loaded with ZnS quantum dots (QDs was created and demonstrated for the discriminative detection of explosives. The synergistic effect of the high surface-to-volume ratio of QDs, the good permeability of nanofibrous membranes and the differential response introduced by surface ligands was played by constructing the sensing array using nanofibrous membranes loaded with ZnS QDs featuring several surface ligands. Interestingly, although the fluorescence quenching of the nanofibrous membranes is not linearly related to the exposure time, the fingerprint of each explosive at different times is very similar in shape, and the fingerprints of the three explosives show different shapes. Three saturated vapors of nitroaromatic explosives could be reliably detected and discriminated by the array at room temperature. This work is the first step toward devising a monitoring system for explosives in the field of public security and defense. It could, for example, be coupled with the technology of image recognition and large data analysis for a rapid diagnostic test of explosives. This work further highlights the power of differential, multichannel arrays for the rapid and discriminative detection of a wide range of chemicals.

Perceived weight discrimination and obesity.

Directory of Open Access Journals (Sweden)

Angelina R Sutin

Full Text Available Weight discrimination is prevalent in American society. Although associated consistently with psychological and economic outcomes, less is known about whether weight discrimination is associated with longitudinal changes in obesity. The objectives of this research are (1 to test whether weight discrimination is associated with risk of becoming obese (Body Mass Index≥30; BMI by follow-up among those not obese at baseline, and (2 to test whether weight discrimination is associated with risk of remaining obese at follow-up among those already obese at baseline. Participants were drawn from the Health and Retirement Study, a nationally representative longitudinal survey of community-dwelling US residents. A total of 6,157 participants (58.6% female completed the discrimination measure and had weight and height available from the 2006 and 2010 assessments. Participants who experienced weight discrimination were approximately 2.5 times more likely to become obese by follow-up (OR = 2.54, 95% CI = 1.58-4.08 and participants who were obese at baseline were three times more likely to remain obese at follow up (OR = 3.20, 95% CI = 2.06-4.97 than those who had not experienced such discrimination. These effects held when controlling for demographic factors (age, sex, ethnicity, education and when baseline BMI was included as a covariate. These effects were also specific to weight discrimination; other forms of discrimination (e.g., sex, race were unrelated to risk of obesity at follow-up. The present research demonstrates that, in addition to poorer mental health outcomes, weight discrimination has implications for obesity. Rather than motivating individuals to lose weight, weight discrimination increases risk for obesity.

Does gender discrimination impact regular mammography screening? Findings from the race differences in screening mammography study.

Science.gov (United States)

Dailey, Amy B; Kasl, Stanislav V; Jones, Beth A

2008-03-01

ABSTRACT Objective: To determine if gender discrimination, conceptualized as a negative life stressor, is a deterrent to adherence to mammography screening guidelines. African American and white women (1451) aged 40-79 years who obtained an index screening mammogram at one of five urban hospitals in Connecticut between October 1996 and January 1998 were enrolled in this study. This logistic regression analysis includes the 1229 women who completed telephone interviews at baseline and follow-up (average 29.4 months later) and for whom the study outcome, nonadherence to age-specific mammography screening guidelines, was determined. Gender discrimination was measured as lifetime experience in seven possible situations. Gender discrimination, reported by nearly 38% of the study population, was significantly associated with nonadherence to mammography guidelines in women with annual family incomes of > or =$50,000 (OR 1.99, 95% CI 1.33, 2.98) and did not differ across racial/ethnic group. Our findings suggest that gender discrimination can adversely influence regular mammography screening in some women. With nearly half of women nonadherent to screening mammography guidelines in this study and with decreasing mammography rates nationwide, it is important to address the complexity of nonadherence across subgroups of women. Life stressors, such as experiences of gender discrimination, may have considerable consequences, potentially influencing health prevention prioritization in women.

On new physics searches with multidimensional differential shapes

Science.gov (United States)

Ferreira, Felipe; Fichet, Sylvain; Sanz, Veronica

2018-03-01

In the context of upcoming new physics searches at the LHC, we investigate the impact of multidimensional differential rates in typical LHC analyses. We discuss the properties of shape information, and argue that multidimensional rates bring limited information in the scope of a discovery, but can have a large impact on model discrimination. We also point out subtleties about systematic uncertainties cancellations and the Cauchy-Schwarz bound on interference terms.

"Discrimination", the Main Concern of Iranian Nurses over Inter-Professional Collaboration: an Explorative Qualitative Study

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Leila Valizadeh

2015-06-01

Full Text Available Introduction: People in various professions may face discrimination. In the nursing field, discrimination among nurses in the workplace, regardless of race, gender or religion have not been studied; a problem that leads to a reduction in the quality of nursing care and nurse turnover. Discovery of the concerns of nurses about inter-professional collaboration is the purpose of this study. Methods: The present study is conducted by using a qualitative content analysis. The data collection process included 22 unstructured and in-depth interviews with nurses between April 2012 and February 2013 in the medical teaching centers of Iran. A purposive sampling method was used. All interviews were recorded, typed, and analyzed simultaneously. Results: The category obtained from explaining nurses' experiences of inter-professional collaboration was "discrimination" that included two subcategories, namely (1 lack of perspective towards equality in authorities, and (2 professional respect and value deficit.Conclusion: Nurses' experiences are indicating their perception of discrimination that influences the collaboration between nurses, which should be taken into account by managers. The findings of the present study help to managers about decision making on how to deal with staff and can be helpful in preventing nurse turnover and providing better services by nurses.

A method for assessment of the shape of the proximal femur and its relationship to osteoporotic hip fracture.

Science.gov (United States)

Gregory, J S; Testi, D; Stewart, A; Undrill, P E; Reid, D M; Aspden, R M

2004-01-01

The shape of the proximal femur has been demonstrated to be important in the occurrence of fractures of the femoral neck. Unfortunately, multiple geometric measurements frequently used to describe this shape are highly correlated. A new method, active shape modeling (ASM) has been developed to quantify the morphology of the femur. This describes the shape in terms of orthogonal modes of variation that, consequently, are all independent. To test this method, digitized standard pelvic radiographs were obtained from 26 women who had suffered a hip fracture and compared with images from 24 age-matched controls with no fracture. All subjects also had their bone mineral density (BMD) measured at five sites using dual-energy X-ray absorptiometry. An ASM was developed and principal components analysis used to identify the modes which best described the shape. Discriminant analysis was used to determine which variable, or combination of variables, was best able to discriminate between the groups. ASM alone correctly identified 74% of the individuals and placed them in the appropriate group. Only one of the BMD values (Ward's triangle) achieved a higher value (82%). A combination of Ward's triangle BMD and ASM improved the accuracy to 90%. Geometric variables used in this study were weaker, correctly classifying less than 60% of the study group. Logistic regression showed that after adjustment for age, body mass index, and BMD, the ASM data was still independently associated with hip fracture (odds ratio (OR)=1.83, 95% confidence interval 1.08 to 3.11). The odds ratio was calculated relative to a 10% increase in the probability of belonging to the fracture group. Though these initial results were obtained from a limited data set, this study shows that ASM may be a powerful method to help identify individuals at risk of a hip fracture in the future.

Mnemonic discrimination relates to perforant path integrity: An ultra-high resolution diffusion tensor imaging study.

Science.gov (United States)

Bennett, Ilana J; Stark, Craig E L

2016-03-01

Pattern separation describes the orthogonalization of similar inputs into unique, non-overlapping representations. This computational process is thought to serve memory by reducing interference and to be mediated by the dentate gyrus of the hippocampus. Using ultra-high in-plane resolution diffusion tensor imaging (hrDTI) in older adults, we previously demonstrated that integrity of the perforant path, which provides input to the dentate gyrus from entorhinal cortex, was associated with mnemonic discrimination, a behavioral outcome designed to load on pattern separation. The current hrDTI study assessed the specificity of this perforant path integrity-mnemonic discrimination relationship relative to other cognitive constructs (identified using a factor analysis) and white matter tracts (hippocampal cingulum, fornix, corpus callosum) in 112 healthy adults (20-87 years). Results revealed age-related declines in integrity of the perforant path and other medial temporal lobe (MTL) tracts (hippocampal cingulum, fornix). Controlling for global effects of brain aging, perforant path integrity related only to the factor that captured mnemonic discrimination performance. Comparable integrity-mnemonic discrimination relationships were also observed for the hippocampal cingulum and fornix. Thus, whereas perforant path integrity specifically relates to mnemonic discrimination, mnemonic discrimination may be mediated by a broader MTL network. Copyright © 2015 Elsevier Inc. All rights reserved.

Interactive lesion segmentation with shape priors from offline and online learning.

Science.gov (United States)

Shepherd, Tony; Prince, Simon J D; Alexander, Daniel C

2012-09-01

In medical image segmentation, tumors and other lesions demand the highest levels of accuracy but still call for the highest levels of manual delineation. One factor holding back automatic segmentation is the exemption of pathological regions from shape modelling techniques that rely on high-level shape information not offered by lesions. This paper introduces two new statistical shape models (SSMs) that combine radial shape parameterization with machine learning techniques from the field of nonlinear time series analysis. We then develop two dynamic contour models (DCMs) using the new SSMs as shape priors for tumor and lesion segmentation. From training data, the SSMs learn the lower level shape information of boundary fluctuations, which we prove to be nevertheless highly discriminant. One of the new DCMs also uses online learning to refine the shape prior for the lesion of interest based on user interactions. Classification experiments reveal superior sensitivity and specificity of the new shape priors over those previously used to constrain DCMs. User trials with the new interactive algorithms show that the shape priors are directly responsible for improvements in accuracy and reductions in user demand.

A Comparative Study of Discrimination in Education: The Learning Environment and Behaviours of Students and Teachers in Iran

Science.gov (United States)

Ghaffarzadeh, Mozhgan

2016-01-01

It is the learners' right to get an education free from discrimination. Discrimination in education ranges from gender to race, age, social class, financial status, and other characteristics. In this study the focus is on discrimination in education in regard to social class and financial status. The paper describes observations of the school…

Spectral discrimination in color blind animals via chromatic aberration and pupil shape.

Science.gov (United States)

Stubbs, Alexander L; Stubbs, Christopher W

2016-07-19

We present a mechanism by which organisms with only a single photoreceptor, which have a monochromatic view of the world, can achieve color discrimination. An off-axis pupil and the principle of chromatic aberration (where different wavelengths come to focus at different distances behind a lens) can combine to provide "color-blind" animals with a way to distinguish colors. As a specific example, we constructed a computer model of the visual system of cephalopods (octopus, squid, and cuttlefish) that have a single unfiltered photoreceptor type. We compute a quantitative image quality budget for this visual system and show how chromatic blurring dominates the visual acuity in these animals in shallow water. We quantitatively show, through numerical simulations, how chromatic aberration can be exploited to obtain spectral information, especially through nonaxial pupils that are characteristic of coleoid cephalopods. We have also assessed the inherent ambiguity between range and color that is a consequence of the chromatic variation of best focus with wavelength. This proposed mechanism is consistent with the extensive suite of visual/behavioral and physiological data that has been obtained from cephalopod studies and offers a possible solution to the apparent paradox of vivid chromatic behaviors in color blind animals. Moreover, this proposed mechanism has potential applicability in organisms with limited photoreceptor complements, such as spiders and dolphins.

Quantitative Outline-based Shape Analysis and Classification of Planetary Craterforms using Supervised Learning Models

Science.gov (United States)

Slezak, Thomas Joseph; Radebaugh, Jani; Christiansen, Eric

2017-10-01

The shapes of craterform morphology on planetary surfaces provides rich information about their origins and evolution. While morphologic information provides rich visual clues to geologic processes and properties, the ability to quantitatively communicate this information is less easily accomplished. This study examines the morphology of craterforms using the quantitative outline-based shape methods of geometric morphometrics, commonly used in biology and paleontology. We examine and compare landforms on planetary surfaces using shape, a property of morphology that is invariant to translation, rotation, and size. We quantify the shapes of paterae on Io, martian calderas, terrestrial basaltic shield calderas, terrestrial ash-flow calderas, and lunar impact craters using elliptic Fourier analysis (EFA) and the Zahn and Roskies (Z-R) shape function, or tangent angle approach to produce multivariate shape descriptors. These shape descriptors are subjected to multivariate statistical analysis including canonical variate analysis (CVA), a multiple-comparison variant of discriminant analysis, to investigate the link between craterform shape and classification. Paterae on Io are most similar in shape to terrestrial ash-flow calderas and the shapes of terrestrial basaltic shield volcanoes are most similar to martian calderas. The shapes of lunar impact craters, including simple, transitional, and complex morphology, are classified with a 100% rate of success in all models. Multiple CVA models effectively predict and classify different craterforms using shape-based identification and demonstrate significant potential for use in the analysis of planetary surfaces.

The dark side of ambiguous discrimination: how state self-esteem moderates emotional and behavioural responses to ambiguous and unambiguous discrimination.

Science.gov (United States)

Cihangir, Sezgin; Barreto, Manuela; Ellemers, Naomi

2010-03-01

Two experiments examine how experimentally induced differences in state self-esteem moderate emotional and behavioural responses to ambiguous and unambiguous discrimination. Study 1 (N=108) showed that participants who were exposed to ambiguous discrimination report more negative self-directed emotions when they have low compared to high self-esteem. These differences did not emerge when participants were exposed to unambiguous discrimination. Study 2 (N=118) additionally revealed that self-esteem moderated the effect of ambiguous discrimination on self-concern, task performance, and self-stereotyping. Results show that ambiguous discrimination caused participants with low self-esteem to report more negative self-directed emotions, more self-concern, an inferior task performance, and more self-stereotyping, compared to participants in the high self-esteem condition. Emotional and behavioural responses to unambiguous discrimination did not depend on the induced level of self-esteem in these studies.

Discrimination across the ideological divide : The role of value violations and abstract values in discrimination by liberals and conservatives

NARCIS (Netherlands)

Wetherell, G.A.; Brandt, M.J.; Reyna, C.

2013-01-01

Despite ample research linking conservatism to discrimination and liberalism to tolerance, both groups may discriminate. In two studies, we investigated whether conservatives and liberals support discrimination against value violators, and whether liberals’ and conservatives’ values distinctly

Experimental Study of an SWH System with V-Shaped Plate

Directory of Open Access Journals (Sweden)

Jalaluddin

2016-05-01

Full Text Available Solar energy is known as an environmentally friendly energy source with a wide range of applications. This energy can be utilized in various applications such as domestic and industrial water heating using solar water heating (SWH systems. The thermal performance of an SWH system using a V-shaped absorber plate is presented in this study. Two SWH systems with different absorber plates, i.e. a flat-plate and a V-shaped plate, have been investigated experimentally. First, the absorptivity of the absorber plates was calculated analytically. The optimum V-shaped configuration with angle at β = 21° (V-shaped dimensions t = 4 cm and l = 4 cm was determined from various V-shaped plate absorbers based on their absorptivity and applied in the experimental study. Two SWH systems were installed and tested at a low flowrate of 0.5 L/min and at a high flowrate of 2 L/min. The results showed that the SWH system with V-shaped plate absorber had a 3.6-4.4% better performance compared with that of the system with flat-plate absorber.

A novel algorithm for discrimination between inrush current and internal faults in power transformer differential protection based on discrete wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)

2011-01-15

This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)

Pedestrian detection and tracking using a mixture of view-based shape-texture models

NARCIS (Netherlands)

Munder, S.; Schnörr, C.; Gavrila, D.M.

2008-01-01

This paper presents a robust multicue approach to the integrated detection and tracking of pedestrians in a cluttered urban environment. A novel spatiotemporal object representation is proposed, which combines a generative shape model and a discriminative texture classifier, both of which are

Perceived discrimination in the Netherlands

NARCIS (Netherlands)

Iris Andriessen; Henk Fernee; Karin Wittebrood

2014-01-01

Only available in electronic version There is no systematic structure in the Netherlands for mapping out the discrimination experiences of different groups in different areas of society. As in many other countries, discrimination studies in the Netherlands mostly focus on the experiences

Quantifying explainable discrimination and removing illegal discrimination in automated decision making

KAUST Repository

Kamiran, Faisal

2012-11-18

Recently, the following discrimination-aware classification problem was introduced. Historical data used for supervised learning may contain discrimination, for instance, with respect to gender. The question addressed by discrimination-aware techniques is, given sensitive attribute, how to train discrimination-free classifiers on such historical data that are discriminative, with respect to the given sensitive attribute. Existing techniques that deal with this problem aim at removing all discrimination and do not take into account that part of the discrimination may be explainable by other attributes. For example, in a job application, the education level of a job candidate could be such an explainable attribute. If the data contain many highly educated male candidates and only few highly educated women, a difference in acceptance rates between woman and man does not necessarily reflect gender discrimination, as it could be explained by the different levels of education. Even though selecting on education level would result in more males being accepted, a difference with respect to such a criterion would not be considered to be undesirable, nor illegal. Current state-of-the-art techniques, however, do not take such gender-neutral explanations into account and tend to overreact and actually start reverse discriminating, as we will show in this paper. Therefore, we introduce and analyze the refined notion of conditional non-discrimination in classifier design. We show that some of the differences in decisions across the sensitive groups can be explainable and are hence tolerable. Therefore, we develop methodology for quantifying the explainable discrimination and algorithmic techniques for removing the illegal discrimination when one or more attributes are considered as explanatory. Experimental evaluation on synthetic and real-world classification datasets demonstrates that the new techniques are superior to the old ones in this new context, as they succeed in

Foreign-born physicians' perceptions of discrimination and stress in Finland: a cross-sectional questionnaire study.

Science.gov (United States)

Heponiemi, Tarja; Hietapakka, Laura; Lehtoaro, Salla; Aalto, Anna-Mari

2018-06-07

Foreign-born physicians fill in the shortage of physicians in many developed countries. Labour market theory and previous studies suggest that foreign-born physicians may be a disadvantaged group with a higher likelihood of discrimination and less prestigious jobs. The present study examines foreign-born physicians' experiences of discrimination (coming from management, colleagues and patients separately) and patient-related stress and integration-related stress, and it examines how gender, age, employment sector, country of birth, years from getting a practicing license in Finland, language problems, cross-cultural training, cross-cultural empathy, team climate and skill discretion were associated with these factors. The present study was a cross-sectional questionnaire study among 371 foreign-born physicians in Finland, aged between 26 and 65 (65% women). Analyses of covariance and logistic regression analyses were conducted to examine the associations. A good team climate and high cross-cultural empathy were associated with lower likelihoods of discrimination from all sources, patient-related stress and integration-related stress. Skill discretion was associated with lower levels of integration-related stress and discrimination from management and colleagues. Language problems were associated with higher levels of integration-related stress. The biggest sources of discrimination were patients and their relatives. The present study showed the importance of a good team climate, cross-cultural empathy and patience, skill discretion and language skills in regard to the proper integration of foreign-born health care employees into the workplace. Good job resources, such as a good team climate and the possibility to use one's skills, may help foreign-born employees, for instance by giving them support when needed and offering flexibility. Health care organizations should invest in continuous language training for foreign-born employees and also offer support when

Discriminant method for the optimization of radionuclide activity in studies of nuclear medicine

International Nuclear Information System (INIS)

Perez Diaz, Marlen

2003-01-01

It is presented a method for the optimization of the radionuclidic activity to administer to mature patients in studies of Nuclear Medicine. The method is based in technical of discriminant analysis to build a function that discriminates groups with image quality differed on the base of physical parameters as they are the contrast image and the aleatory noise. The image quality is the dependent variable and it is selected by means of experts' evaluation and technical of clustering. The function is a lineal combination of a reduced group of variables physical-medical, able to discriminate the groups starting from a big group of variables measures. The method allows, also, to establish the relative weight of each discriminant variable selected . The behavior of the same ones is analyzed among studies carried out with different administered activity, with the objective of determining the minimum value of this that still allows good results in the image quality (Approach of activity optimization). It is validated the method by means of results comparison with the grateful Curved ROC in studies carried out with the Mannequins of Jaszczak (for planar studies) and of Insert Heart (for studies of SPECT). The optim activity value of the 99mTc, obtained with the application of the method, was coincident with the one obtained after the application of the method ROC to 6 expert observers as much in planar studies as in SPECT for two different cameras gamma. The method was applied later on in static, dynamic studies and of SPECT carried out with camera gamma to a mature population of 210 patient. The decisive variables of the quality of the image were obtained in the nuclear venticulography in rest, the bony gammagraphy, the nuclear renogram, the renal gammagraphy and the cerebral SPECT, as well as some activity values optimized for the equipment conditions and available radiopharmac in the country, allowing to establish a better commitment relationship between image quality

Automatic discrimination of bubbles and slugs in two-phase gas-liquid flow and measurement of the respective velocities

International Nuclear Information System (INIS)

Fitremann, J.M.; Guilpin, C.; Postaire, J.

1976-01-01

The measurement of the interface velocity in a two-phase gas-liquid flow is a difficult problem, owing to the dispersion of the velocity components of individual bubbles, gas-slugs, droplets, waves, etc. An entirely automatic method is presented, it gives the velocity of slugs and bubbles independently, by discrimination of local phase probe signals into a 'slug' signal and a 'bubble' signal feeding a shape-recognition program. Both discriminated void fractions are also calculated by the apparatus [fr

Experienced and anticipated discrimination against people with schizophrenia

Directory of Open Access Journals (Sweden)

Milačić-Vidojević Ivona

2011-01-01

Full Text Available Aim of this research was to describe the nature, direction and severity of anticipated and experienced discrimination reported by people with schizophrenia. We applied interview to 50 patients with diagnosis of schizophrenia in two psychiatric hospitals in Belgrade. Discrimination was measured with discrimination and stigma scale (DISC which produce 3 subscores, positive experienced discrimination, negative experienced discrimination and anticipated discrimination. The same scale was used in cross-cultural research in 27 european countries. Results have shown that participants from Serbia do not recognize discrimination in all areas of life equally. The discrimination recognized is more frequentlly negative then positive and is associated with existentially important realms of life. Due to anticipated discrimination participants in our study prevent themselves from looking for a close relationship. Anticipated discrimination could not be predicted on the grounds of experienced, positive or negative discrimination.

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm.

Science.gov (United States)

Poblano, Adrián; Castro-Sierra, Eduardo; Arteaga, Carmina; Pérez-Ruiz, Santiago J

Zapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec. We employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age. We observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination. Our data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Discriminant analysis on the treatment results of interstitial radium tongue implants

International Nuclear Information System (INIS)

Hoshina, Masao; Shibuya, Hitoshi; Horiuchi, Jun-Ichi; Matsubara, Sho; Suzuki, Soji; Takeda, Masamune

1989-01-01

Discriminant analysis was carried out for 48 tongue cancer patients who were treated with radium single-plane implantation. The 48 patients were grouped into 32 successfully cured without complications, five successfully cured with complications, six successfully cured but requiring additional boost therapy and five with local recurrence. To evaluate the relation between the dose distribution and the local treatment results, the analysis was based on a volume-dose relationship. The functions introduced by this discriminant analysis were linear, and the parameters used were modal dose, average dose and shape factors of histograms. Each group of treatment results had a correction rate of >80%, except for the successfully cured group with ulcers. The discriminant functions were useful as an index to obtain a final clinical treatment result at the early time of implantation, and these functions could be used as a criterion for the optimal treatment of tongue carcinoma. We were also able to recognize the limitation of the actual arrangement of sources in the single-plane implant. (author)

Discrimination against Muslim American Adolescents

Science.gov (United States)

Aroian, Karen J.

2012-01-01

Although there is ample evidence of discrimination toward Muslim Americans in general, there is limited information specific to Muslim American adolescents. The few existing studies specific to this age group suggest that Muslim American adolescents encounter much discrimination from teachers, school administrators, and classmates. This…

Discrimination of animate and inanimate motion in 9-month-old infants: an ERP study.

Science.gov (United States)

Kaduk, Katharina; Elsner, Birgit; Reid, Vincent M

2013-10-01

Simple geometric shapes moving in a self-propelled manner, and violating Newtonian laws of motion by acting against gravitational forces tend to induce a judgement that an object is animate. Objects that change their motion only due to external causes are more likely judged as inanimate. How the developing brain is employed in the perception of animacy in early ontogeny is currently unknown. The aim of this study was to use ERP techniques to determine if the negative central component (Nc), a waveform related to attention allocation, was differentially affected when an infant observed animate or inanimate motion. Short animated movies comprising a marble moving along a marble run either in an animate or an inanimate manner were presented to 15 infants who were 9 months of age. The ERPs were time-locked to a still frame representing animate or inanimate motion that was displayed following each movie. We found that 9-month-olds are able to discriminate between animate and inanimate motion based on motion cues alone and most likely allocate more attentional resources to the inanimate motion. The present data contribute to our understanding of the animate-inanimate distinction and the Nc as a correlate of infant cognitive processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Study of event shape variables at LEP

CERN Document Server

Sarkar, Subir

1997-01-01

We present the LEP results on the study of the hadronic event shape variables. Excellent detector performance and improved theoretical calculations make it possible to study quantum chromodynamics with small experimental and theoretical uncertainties. QCD predictions describe data well at energies above the Z peak.

Discrimination and the health of immigrants and refugees: exploring Canada's evidence base and directions for future research in newcomer receiving countries.

Science.gov (United States)

Edge, Sara; Newbold, Bruce

2013-02-01

Research and practice increasingly suggests discrimination compromises health. Yet the unique experiences and effects facing immigrant and refugee populations remain poorly understood in Canada and abroad. We review current knowledge on discrimination against newcomers in Canada, emphasizing impacts upon health status and service access to identify gaps and research needs. Existing knowledge centers around experiences within health-care settings, differences in perception and coping, mental health impacts, and debates about "non-discriminatory" health-care. There is need for comparative analyses within and across ethno-cultural groups and newcomer classes to better understand factors shaping how discrimination and its health effects are differentially experienced. Women receive greater attention in the literature given their compounded vulnerability. While this must continue, little is known about the experiences of youth and men. Governance and policy discourse analyses would elucidate how norms, institutions and practices shape discriminatory attitudes and responses. Finally, "non-discriminatory health-care" interventions require critical evaluation to determine their effectiveness.

Pulse-width discriminators

International Nuclear Information System (INIS)

Budyashov, Yu.G.; Grebenyuk, V.M.; Zinov, V.G.

1978-01-01

A pulse duration discriminator is described which is intended for processing signals from multilayer scintillators. The basic elements of the scintillator are: an input gate, a current generator, an integrating capacitor, a Schmidt trigger and an anticoincidence circuit. The basic circuit of the discriminator and its time diagrams explaining its operating are given. The discriminator is based on microcircuits. Pulse duration discrimination threshold changes continuously from 20 to 100 ns, while its amplitude threshold changes within 20 to 100 mV. The temperature instability of discrimination thresholds (both in pulse width and in amplitude) is better than 0.1 per cent/deg C

Perceived Discrimination and Heavy Episodic Drinking Among African-American Youth: Differences by Age and Reason for Discrimination.

Science.gov (United States)

Madkour, Aubrey Spriggs; Jackson, Kristina; Wang, Heng; Miles, Thomas T; Mather, Frances; Shankar, Arti

2015-11-01

The purpose of this study was to examine whether associations between perceived discrimination and heavy episodic drinking (HED) vary by age and by discrimination type (e.g., racial, age, physical appearance) among African-American youth. National data from the Panel Study of Income Dynamics Transition to Adulthood Study were analyzed. Youth participated in up to four interviews (2005, 2007, 2009, 2011; n = 657) between ages 18 and 25 years. Respondents reported past-year engagement in HED (four or more drinks for females, five or more drinks for males) and frequency of discriminatory acts experienced (e.g., receiving poor service, being treated with less courtesy). Categorical latent growth curve models, including perceived discrimination types (racial, age, and physical appearance) as a time-varying predictors of HED, were run. Controls for gender, birth cohort, living arrangement in adolescence, familial wealth, parental alcohol use, and college attendance were explored. The average HED trajectory was curvilinear (increasing followed by flattening), whereas perceived discrimination remained flat with age. In models including controls, odds of HED were significantly higher than average around ages 20-21 years with greater frequency of perceived racial discrimination; associations were not significant at other ages. Discrimination attributed to age or physical appearance was not associated with HED at any age. Perceived racial discrimination may be a particularly salient risk factor for HED around the ages of transition to legal access to alcohol among African-American youth. Interventions to reduce discrimination or its impact could be targeted before this transition to ameliorate the negative outcomes associated with HED. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Discrimination, internalized racism, and depression: A comparative study of African American and Afro-Caribbean adults in the US

Science.gov (United States)

Molina, Kristine M.; James, Drexler

2016-01-01

Emerging research suggests that both perceptions of discrimination and internalized racism (i.e., endorsement of negative stereotypes of one’s racial group) are associated with poor mental health. Yet, no studies to date have examined their effects on mental health with racial/ethnic minorities in the US in a single study. The present study examined: (a) the direct effects of everyday discrimination and internalized racism on risk of DSM-IV criteria of past-year major depressive disorder (MDD); (b) the interactive effects of everyday discrimination and internalized racism on risk of past-year MDD; and (c) the indirect effect of everyday discrimination on risk of past-year MDD via internalized racism. Further, we examined whether these associations differed by ethnic group membership. We utilized nationally representative data of Afro-Caribbean (N = 1,418) and African American (N = 3,570) adults from the National Survey of American Life. Results revealed that experiencing discrimination was associated with increased odds of past-year MDD among the total sample. Moreover, for Afro-Caribbeans, but not African Americans, internalized racism was associated with decreased odds of meeting criteria for past-year MDD. We did not find an interaction effect for everyday discrimination by internalized racism, nor an indirect effect of discrimination on risk of past-year MDD through internalized racism. Collectively, our findings suggest a need to investigate other potential mechanisms by which discrimination impacts mental health, and examine further the underlying factors of internalized racism as a potential self-protective strategy. Lastly, our findings point to the need for research that draws attention to the heterogeneity within the U.S. Black population. PMID:28405176

Discriminant validity of well-being measures.

Science.gov (United States)

Lucas, R E; Diener, E; Suh, E

1996-09-01

The convergent and discriminant validities of well-being concepts were examined using multitrait-multimethod matrix analyses (D. T. Campbell & D. W. Fiske, 1959) on 3 sets of data. In Study 1, participants completed measures of life satisfaction, positive affect, negative affect, self-esteem, and optimism on 2 occasions 4 weeks apart and also obtained 3 informant ratings. In Study 2, participants completed each of the 5 measures on 2 occasions 2 years apart and collected informant reports at Time 2. In Study 3, participants completed 2 different scales for each of the 5 constructs. Analyses showed that (a) life satisfaction is discriminable from positive and negative affect, (b) positive affect is discriminable from negative affect, (c) life satisfaction is discriminable from optimism and self-esteem, and (d) optimism is separable from trait measures of negative affect.

Chiral discrimination in biomimetic systems: Phenylalanine

Indian Academy of Sciences (India)

Chiral discrimination and recognition is important in peptide biosynthesis, amino acid synthesis and drug designing. Detailed structural information is available about the peptide synthesis in ribosome. However, no detailed study is available about the discrimination in peptide synthesis. We study the conformational energy ...

HPGe detectors timing using pulse shape analysis techniques

International Nuclear Information System (INIS)

Crespi, F.C.L.; Vandone, V.; Brambilla, S.; Camera, F.; Million, B.; Riboldi, S.; Wieland, O.

2010-01-01

In this work the Pulse Shape Analysis has been used to improve the time resolution of High Purity Germanium (HPGe) detectors. A set of time aligned signals was acquired in a coincidence measurement using a coaxial HPGe and a cerium-doped lanthanum chloride (LaCl 3 :Ce) scintillation detector. The analysis using a Constant Fraction Discriminator (CFD) time output versus the HPGe signal shape shows that time resolution ranges from 2 to 12 ns depending on the slope in the initial part of the signal. An optimization procedure of the CFD parameters gives the same final time resolution (8 ns) as the one achieved after a correction of the CFD output based on the current pulse maximum position. Finally, an algorithm based on Pulse Shape Analysis was applied to the experimental data and a time resolution between 3 and 4 ns was obtained, corresponding to a 50% improvement as compared with that given by standard CFDs.

Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo.

Science.gov (United States)

Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A

2008-12-01

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo (including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group 'distinctness values') was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of 'distinctness values' was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of 'distinctness values' test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the

Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo

Science.gov (United States)

Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A

2008-01-01

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo(including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group ‘distinctness values’) was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of ‘distinctness values’ was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of ‘distinctness values’ test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups

Associations Between Perceived Race-based Discrimination and Contraceptive Use Among Women Veterans in the ECUUN Study.

Science.gov (United States)

MacDonald, Serena; Hausmann, Leslie R M; Sileanu, Florentina E; Zhao, Xinhua; Mor, Maria K; Borrero, Sonya

2017-09-01

To describe perceived race-based discrimination in Veterans Affairs (VA) health care settings and assess its associations with contraceptive use among a sample of women Veterans. This study used data from a national telephone survey of women Veterans aged 18-44 receiving health care in VA who were at risk of unintended pregnancy. Participants were asked about their perceptions of race-based discrimination while seeking VA health care and about their contraceptive use at last heterosexual intercourse. Logistic and multinomial regression analyses were used to examine associations between perceived race-based discrimination with use of prescription contraception. In our sample of 1341 women Veterans, 7.9% report perceived race-based discrimination when receiving VA care, with blacks and Hispanics reporting higher levels of perceived discrimination than white women (11.3% and 11.2% vs. 4.4%; Pwomen who perceived race-based discrimination were less likely to use any prescription birth control than women who did not (odds ratio, 0.65; 95% confidence interval, 0.42-1.00), with the largest difference seen in rates of intrauterine device or implant use (odds ratio, 0.40; 95% confidence interval, 0.20-0.79). In this national sample of women Veterans, over 10% of racial/ethnic minority women perceived race-based discrimination when receiving care in VA settings, and perceived racial/ethnic discrimination was associated with lower likelihood of prescription contraception use, especially intrauterine devices and implants. VA efforts to enhance respectful interactions may not only improve patient health care experiences, but also represent an opportunity to improve reproductive health outcomes for women Veterans.

Weight-based discrimination: an ubiquitary phenomenon?

Science.gov (United States)

Sikorski, C; Spahlholz, J; Hartlev, M; Riedel-Heller, S G

2016-02-01

Despite strong indications of a high prevalence of weight-related stigmatization in individuals with obesity, limited attention has been given to the role of weight discrimination in examining the stigma obesity. Studies, up to date, rely on a limited basis of data sets and additional studies are needed to confirm the findings of previous studies. In particular, data for Europe are lacking, and are needed in light of a recent ruling of the European Court of Justice that addressed weight-based discrimination. The data were derived from a large representative telephone survey in Germany (n=3003). The dependent variable, weight-based discrimination, was assessed with a one-item question. The lifetime prevalence of weight discrimination across different sociodemographic variables was determined. Logistic regression models were used to assess the association of independent and dependent variables. A sub-group analysis was conducted analyzing all participants with a body mass index ⩾25 kg m(-)(2). The overall prevalence of weight-based discrimination was 7.3%. Large differences, however, were observed regarding weight status. In normal weight and overweight participants the prevalence was 5.6%, but this number doubled in participants with obesity class I (10.2%), and quadrupled in participants with obesity class II (18.7%) and underweight (19.7%). In participants with obesity class III, every third participant reported accounts of weight-based discrimination (38%). In regression models, after adjustment, the associations of weight status and female gender (odds ratio: 2.59, PDiscrimination seems to be an ubiquitary phenomenon at least for some groups that are at special risk, such as heavier individuals and women. Our findings therefore emphasize the need for research and intervention on weight discrimination among adults with obesity, including anti-discrimination legislation.

Gender Discrimination in Jessica's Career.

Science.gov (United States)

Cook, Ellen Piel

1997-01-01

Focuses on the sexual harassment and other gender-related difficulties faced by a Chinese-American woman. Profiles her encounters with gender discrimination and how it hindered career advancement and led to professional isolation. Relates how this case study can be used to sensitize workers to gender discrimination. (RJM)

Drug use Discrimination Predicts Formation of High-Risk Social Networks: Examining Social Pathways of Discrimination.

Science.gov (United States)

Crawford, Natalie D; Ford, Chandra; Rudolph, Abby; Kim, BoRin; Lewis, Crystal M

2017-09-01

Experiences of discrimination, or social marginalization and ostracism, may lead to the formation of social networks characterized by inequality. For example, those who experience discrimination may be more likely to develop drug use and sexual partnerships with others who are at increased risk for HIV compared to those without experiences of discrimination. This is critical as engaging in risk behaviors with others who are more likely to be HIV positive can increase one's risk of HIV. We used log-binomial regression models to examine the relationship between drug use, racial and incarceration discrimination with changes in the composition of one's risk network among 502 persons who use drugs. We examined both absolute and proportional changes with respect to sex partners, drug use partners, and injecting partners, after accounting for individual risk behaviors. At baseline, participants were predominately male (70%), black or Latino (91%), un-married (85%), and used crack (64%). Among those followed-up (67%), having experienced discrimination due to drug use was significantly related to increases in the absolute number of sex networks and drug networks over time. No types of discrimination were related to changes in the proportion of high-risk network members. Discrimination may increase one's risk of HIV acquisition by leading them to preferentially form risk relationships with higher-risk individuals, thereby perpetuating racial and ethnic inequities in HIV. Future social network studies and behavioral interventions should consider whether social discrimination plays a role in HIV transmission.

Measurement of the ratio Γbb/Γhad using event shape variables

Science.gov (United States)

Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xie, D.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Levinthal, D.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Lan Wu, Sau; Wu, X.; Zheng, M.; Zobernig, G.

1993-09-01

The branching fraction of Z --> bb relative to all hadronic decays of the Z has been measured using event shape variables to preferentially select Z --> bb events. The method chosen applies a combination of shape discriminators and the selection of high transverse momentum leptons to event hemispheres. From a sample of 440 000 hadronic Z decays collected with the ALEPH detector at LEP, the ration Γbb/Γhad = 0.228+/-0.005(stat.)+/-0.005(syst.) is measured. Supported by the US Department of Energy, contract DE-AC02-76ER00881.

Insiders' Insight: Discrimination against Indigenous Peoples through the Eyes of Health Care Professionals.

Science.gov (United States)

Wylie, Lloy; McConkey, Stephanie

2018-05-07

Discrimination in the health care system has a direct negative impact on health and wellbeing. Experiences of discrimination are considered a root cause for the health inequalities that exist among Indigenous peoples. Experiences of discrimination are commonplace, with patients noting abusive treatment, stereotyping, and a lack of quality in the care provided, which discourage Indigenous people from accessing care. This research project examined the perspectives of health care providers and decision-makers to identify what challenges they see facing Indigenous patients and families when accessing health services in a large city in southern Ontario. Discrimination against Indigenous people was identified as major challenges by respondents, noting that it is widespread. This paper discusses the three key discrimination subthemes that were identified, including an unwelcoming environment, stereotyping and stigma, and practice informed by racism. These findings point to the conclusion that in order to improve health care access for Indigenous peoples, we need to go beyond simply making health services more welcoming and inclusive. Practice norms shaped by biases informed by discrimination against Indigenous people are widespread and compromise standards of care. Therefore, the problem needs to be addressed throughout the health care system as part of a quality improvement strategy. This will require not only a significant shift in the attitudes, knowledge, and skills of health care providers, but also the establishment of accountabilities for health care organizations to ensure equitable health services for Indigenous peoples.

Quantifying explainable discrimination and removing illegal discrimination in automated decision making

NARCIS (Netherlands)

Kamiran, F.; Zliobaite, I.; Calders, T.G.K.

2013-01-01

Recently, the following discrimination-aware classification problem was introduced. Historical data used for supervised learning may contain discrimination, for instance, with respect to gender. The question addressed by discrimination-aware techniques is, given sensitive attribute, how to train

Superior haptic-to-visual shape matching in autism spectrum disorders.

Science.gov (United States)

Nakano, Tamami; Kato, Nobumasa; Kitazawa, Shigeru

2012-04-01

A weak central coherence theory in autism spectrum disorder (ASD) proposes that a cognitive bias toward local processing in ASD derives from a weakness in integrating local elements into a coherent whole. Using this theory, we hypothesized that shape perception through active touch, which requires sequential integration of sensorimotor traces of exploratory finger movements into a shape representation, would be impaired in ASD. Contrary to our expectation, adults with ASD showed superior performance in a haptic-to-visual delayed shape-matching task compared to adults without ASD. Accuracy in discriminating haptic lengths or haptic orientations, which lies within the somatosensory modality, did not differ between adults with ASD and adults without ASD. Moreover, this superior ability in inter-modal haptic-to-visual shape matching was not explained by the score in a unimodal visuospatial rotation task. These results suggest that individuals with ASD are not impaired in integrating sensorimotor traces into a global visual shape and that their multimodal shape representations and haptic-to-visual information transfer are more accurate than those of individuals without ASD. Copyright © 2012 Elsevier Ltd. All rights reserved.

Perceived Discrimination among Black Youth: An 18-Year Longitudinal Study

Directory of Open Access Journals (Sweden)

Shervin Assari

2018-04-01

Full Text Available Background: Recent research has suggested vulnerability to perceived racial discrimination (PRD as a mechanism behind high levels of depression seen in high socioeconomic status (SES Black males. To better understand the effects of gender and SES on shaping experiences of PRD among Black youth in the United States, we used data from the Family and Community Health Study (FACHS to explore the trajectory of PRD in Black youth by gender, SES, and place. Methods: Data came from FACHS, 1997–2017, which followed 889 children aged 10–12 years old at Wave 1 (n = 478; 53.8% females and n = 411; 46.2% males for up to 18 years. Data were collected in seven waves. The main predictors of interest were gender, SES (parent education and annual family income, age, and place of residence. Main outcomes of interest were baseline and slope of PRD. Latent growth curve modeling (LGCM was used for data analysis. Results: Gender, SES, place, and age were correlated with baseline and change in PRD over time. Male, high family income, and younger Black youth reported lower PRD at baseline but a larger increase in PRD over time. Youth who lived in Iowa (in a predominantly White area reported higher PRD at baseline and also an increase in PRD over time. High parental education was not associated with baseline or change in PRD. Conclusion: In the United States, Black youth who are male, high income, and live in predominantly White areas experience an increase in PRD over time. Future research is needed on the interactions between gender, SES, and place on exposure and vulnerability of Black youth to PRD. Such research may explain the increased risk of depression in high SES Black males.

Discrimination of high-Z materials in concrete-filled containers using muon scattering tomography

Science.gov (United States)

Frazão, L.; Velthuis, J.; Thomay, C.; Steer, C.

2016-07-01

An analysis method of identifying materials using muon scattering tomography is presented, which uses previous knowledge of the position of high-Z objects inside a container and distinguishes them from similar materials. In particular, simulations were performed in order to distinguish a block of Uranium from blocks of Lead and Tungsten of the same size, inside a concrete-filled drum. The results show that, knowing the shape and position from previous analysis, it is possible to distinguish 5 × 5 × 5 cm3 blocks of these materials with about 4h of muon exposure, down to 2 × 2 × 2 cm3 blocks with 70h of data using multivariate analysis (MVA). MVA uses several variables, but it does not benefit the discrimination over a simpler method using only the scatter angles. This indicates that the majority of discrimination is provided by the angular information. Momentum information is shown to provide no benefits in material discrimination.

Scoliosis correction with shape-memory metal : results of an experimental study

NARCIS (Netherlands)

Elstrodt, JA; Veldhuizen, AG; van Horn, [No Value

The biocompatibility and functionality of a new scoliosis correction device, based on the properties of the shape-memory metal nickel-titanium alloy, were studied. With this device, the shape recovery forces of a shape-memory metal rod are used to achieve a gradual three-dimensional scoliosis

Social Status Correlates of Reporting Racial Discrimination and Gender Discrimination among Racially Diverse Women

Science.gov (United States)

Ro, Annie E.; Choi, Kyung-Hee

2009-01-01

The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning clinics in Northern California (11.4% African American, 16.8% Latina, 10.1% Asian and 61.7% Caucasian). A multivariate analysis revealed that race, financial difficulty and marital status were significantly correlated with higher reports of racial discrimination, while race, education, financial difficulty and nativity were significantly correlated with gender discrimination scores. Our findings suggest that the social patterning of perceiving racial discrimination is somewhat different from that of gender discrimination. This has implications in the realm of discrimination research and applied interventions, as different forms of discrimination may have unique covariates that should be accounted for in research analysis or program design. PMID:19485231

Social status correlates of reporting gender discrimination and racial discrimination among racially diverse women.

Science.gov (United States)

Ro, Annie E; Choi, Kyung-Hee

2009-01-01

The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning clinics in North California (11.4% African American, 16.8% Latina, 10.1% Asian and 61.7% Caucasian). A multivariate analysis revealed that race, financial difficulty and marital status were significantly correlated with higher reports of racial discrimination, while race, education, financial difficulty and nativity were significantly correlated with gender discrimination scores. Our findings suggest that the social patterning of perceiving racial discrimination is somewhat different from that of gender discrimination. This has implications in the realm of discrimination research and applied interventions, as different forms of discrimination may have unique covariates that should be accounted for in research analysis or program design.

Atlas-based analysis of cardiac shape and function: correction of regional shape bias due to imaging protocol for population studies.

Science.gov (United States)

Medrano-Gracia, Pau; Cowan, Brett R; Bluemke, David A; Finn, J Paul; Kadish, Alan H; Lee, Daniel C; Lima, Joao A C; Suinesiaputra, Avan; Young, Alistair A

2013-09-13

Cardiovascular imaging studies generate a wealth of data which is typically used only for individual study endpoints. By pooling data from multiple sources, quantitative comparisons can be made of regional wall motion abnormalities between different cohorts, enabling reuse of valuable data. Atlas-based analysis provides precise quantification of shape and motion differences between disease groups and normal subjects. However, subtle shape differences may arise due to differences in imaging protocol between studies. A mathematical model describing regional wall motion and shape was used to establish a coordinate system registered to the cardiac anatomy. The atlas was applied to data contributed to the Cardiac Atlas Project from two independent studies which used different imaging protocols: steady state free precession (SSFP) and gradient recalled echo (GRE) cardiovascular magnetic resonance (CMR). Shape bias due to imaging protocol was corrected using an atlas-based transformation which was generated from a set of 46 volunteers who were imaged with both protocols. Shape bias between GRE and SSFP was regionally variable, and was effectively removed using the atlas-based transformation. Global mass and volume bias was also corrected by this method. Regional shape differences between cohorts were more statistically significant after removing regional artifacts due to imaging protocol bias. Bias arising from imaging protocol can be both global and regional in nature, and is effectively corrected using an atlas-based transformation, enabling direct comparison of regional wall motion abnormalities between cohorts acquired in separate studies.

Different conceptions of anti-discrimination: an analytical framework

DEFF Research Database (Denmark)

Olsen, Tore Vincents

2011-01-01

In social science and legal studies there is a lack of clarity in the categorisation of different national anti-discrimination policies. To remedy this situation, the article develops an analytical framework for categorising anti-discrimination policies. It suggests that it is useful to distinguish...... between assimilationist, liberal and multiculturalist anti-discrimination policies and demonstrates the usefulness of the analytical framework by analysing the Danish anti-discrimination policy. The categorisation of anti-discrimination policies as assimilationist, liberal or multiculturalist depends...

Elliptic Fourier Analysis of body shape variation of Hippocampus spp. (seahorse in Danajon Bank, Philippines

Directory of Open Access Journals (Sweden)

S. R. M. Tabugo-Rico

2017-12-01

Full Text Available Seahorses inhabit various ecosystems hence, had become a flagship species of the marine environment. The Philippines as a hot spot of biodiversity in Asia holds a number of species of seahorses. This serve as an exploratory study to describe body shape variation of selected common seahorse species: Hippocampus comes, Hippocampus histrix, Hippocampus spinosissimus and Hippocampus kuda from Danajon bank using Elliptic Fourier Analysis. The method was done to test whether significant yet subtle differences in body shape variation can be species-specific, habitat-influenced and provide evidence of sexual dimorphism. It is hypothesized that phenotypic divergence may provide evidence for genetic differentiation or mere adaptations to habitat variation. Results show significant considerable differences in the body shapes of the five populations based on the canonical variate analysis (CVA and multivariate analysis of variance (MANOVA with significant p values. Populations were found to be distinct from each other suggesting that body shape variation is species-specific, habitat-influenced and provided evidence for sexual dimorphism. Results of discriminant analysis show further support for species specific traits and sexual dimorphism. This study shows the application of the method of geometric morphometrics specifically elliptic fourier analysis in describing subtle body shape variation of selected Hippocampus species.

Effect of noise on the performance of Digital Charge Comparison method for n-γ discrimination

International Nuclear Information System (INIS)

Singh, Harleen; Mehra, Rohit

2017-01-01

The neutron-gamma discrimination from a mixed radiation field is of prime importance in the field of nuclear safeguards, nuclear fission, radiation therapy etc. The liquid scintillators are widely used for n-γ discrimination as the relative decay rate of neutron pulse is less as compared to γ - ray in these detectors.The most popular and simple technique for pulse shape discrimination (PSD) is the charge comparison (CC). Due to the availability of fast ADCs and FPGAs, the traditional analogue techniques can be implemented in digital domain by sampling the PMT pulses. The performance of a PSD method depends on various parameters like sampling rate, noise distortion in the pulses the duration of processing gate etc. In this paper, the effect of noise levels on the performance of CC method is investigated at optimized processing gate

Chronic discrimination and bodily pain in a multiethnic cohort of midlife women in the Study of Women's Health Across the Nation.

Science.gov (United States)

Dugan, Sheila A; Lewis, Tené T; Everson-Rose, Susan A; Jacobs, Elizabeth A; Harlow, Siobán D; Janssen, Imke

2017-09-01

A growing literature links discrimination to key markers of biobehavioral health. While racial or ethnic differences in pain are seen in experimental and clinical studies, the authors were interested in how chronic discrimination contributes to pain within multiple racial or ethnic groups over time. Participants were 3056 African American, Caucasian, Chinese, Hispanic, and Japanese women from the Study of Women's Health Across the Nation. The Everyday Discrimination Scale was assessed from baseline through 13 follow-up examinations. The bodily pain subscale of the MOS 36-Item Short-Form Health Survey (SF-36) was assessed annually. There were large racial or ethnic differences in reports of discrimination and pain. Discrimination attributions also varied by race or ethnicity. In linear mixed model analyses, initially adjusted for age, education, and pain medications, chronic everyday discrimination was associated with more bodily pain in all ethnic groups (beta = -5.84; P discrimination remained a significant predictor of pain for African American (beta = -4.50; P discrimination were strongly linked to reports of bodily pain for the majority of women. Further research is needed to determine if addressing psychosocial stressors, such as discrimination, with patients can enhance clinical management of pain symptoms.

Social Status Correlates of Reporting Racial Discrimination and Gender Discrimination among Racially Diverse Women

OpenAIRE

Ro, Annie E.; Choi, Kyung-Hee

2009-01-01

The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning ...

Children's Perceptions of Gender Discrimination

Science.gov (United States)

Brown, Christia Spears; Bigler, Rebecca S.

2004-01-01

Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the…

Scoliosis correction with shape-memory metal: results of an experimental study

OpenAIRE

Wever, D.; Elstrodt, J.; Veldhuizen, A.; v Horn, J.

2001-01-01

The biocompatibility and functionality of a new scoliosis correction device, based on the properties of the shape-memory metal nickel-titanium alloy, were studied. With this device, the shape recovery forces of a shape-memory metal rod are used to achieve a gradual three-dimensional scoliosis correction. In the experimental study the action of the new device was inverted: the device was used to induce a scoliotic curve instead of correcting one. Surgical procedures were performed in six pigs....

MR1-restricted MAIT cells display ligand discrimination and pathogen selectivity through distinct T cell receptor usage

DEFF Research Database (Denmark)

Gold, Marielle C.; McLaren, James E.; Reistetter, Joseph A.

2015-01-01

with this interpretation, MAIT cell clones with distinct TCRs responded differentially to a riboflavin metabolite. These results suggest that MAIT cells can discriminate between pathogen-derived ligands in a clonotype-dependent manner, providing a basis for adaptive memory via recruitment of specific repertoires shaped...

Social identity change in response to discrimination.

Science.gov (United States)

Perozzo, Cristina; de la Sablonnière, Roxane; Auger, Emilie; Caron-Diotte, Mathieu

2016-09-01

This study investigated the conditions under which discrimination can lead to social identity changes among members of a minority group. Both positive and negative relations between perceptions of discrimination and social identity have previously been reported. To explain the conflicting results and understand the complex reality of members of stigmatized groups, we argue that group-based emotions (e.g., group-based dissatisfaction) and ambiguity of discrimination cues (i.e., overt vs. ambiguous) need to be considered. We hypothesized that perceptions of discrimination would play a moderating role between group-based dissatisfaction and social identity change in a context of ambiguous, but not of overt, discrimination. The sample was comprised of 151 Arab Muslims living in the province of Quebec. Participants read fictitious newspaper articles portraying either overt (n = 76) or ambiguous (n = 75) discrimination towards in-group members. Results revealed that for participants in the overt discrimination condition, only group-based dissatisfaction was positively associated with social identity change. In contrast, for the participants in the ambiguous discrimination condition, those who perceived little discrimination and felt low group-based dissatisfaction reported a decrease in social identity. However, those who perceived low group discrimination and felt high group-based dissatisfaction reported a positive social identity change. © 2016 The British Psychological Society.

Perceived discrimination, humiliation, and mental health: a mixed-methods study among Haitian migrants in the Dominican Republic.

Science.gov (United States)

Keys, Hunter M; Kaiser, Bonnie N; Foster, Jennifer W; Burgos Minaya, Rosa Y; Kohrt, Brandon A

2015-01-01

Many Haitian migrants live and work as undocumented laborers in the Dominican Republic. This study examines the legacy of anti-Haitian discrimination in the Dominican Republic and association of discrimination with mental health among Haitian migrants. This study used mixed methods to generate hypotheses for associations between discrimination and mental health of Haitian migrants in the Dominican Republic. In-depth interviews were conducted with 21 Haitian and 18 Dominican community members and clinicians. One hundred and twenty-seven Haitian migrants participated in a pilot cross-sectional community survey. Instruments included culturally adapted Kreyòl versions of the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) and a locally developed function impairment scale. Haitian migrants described humiliation (imilyasyon) as a reason for mental distress and barrier to health care. Dominicans reported that discrimination (discriminación) was not a current social problem and attributed negative social interactions to sociocultural, behavioral, and biological differences between Dominicans and Haitians. These qualitative findings were supported in the quantitative analyses. Perceived discrimination was significantly associated with depression severity and functional impairment. Perceived mistreatment by Dominicans was associated with a 6.6-point increase in BDI score (90% confidence interval [CI]: 3.29, 9.9). Knowing someone who was interrogated or deported was associated with a 3.4-point increase in BAI score (90% CI: 0.22, 6.64). Both qualitative and quantitative methods suggest that perceived discrimination and the experience of humiliation contribute to Haitian migrant mental ill-health and limit access to health care. Future research should evaluate these associations and identify intervention pathways for both improved treatment access and reduction of discrimination-related health risk factors.

Object Recognition in Flight: How Do Bees Distinguish between 3D Shapes?

Science.gov (United States)

Werner, Annette; Stürzl, Wolfgang; Zanker, Johannes

2016-01-01

Honeybees (Apis mellifera) discriminate multiple object features such as colour, pattern and 2D shape, but it remains unknown whether and how bees recover three-dimensional shape. Here we show that bees can recognize objects by their three-dimensional form, whereby they employ an active strategy to uncover the depth profiles. We trained individual, free flying honeybees to collect sugar water from small three-dimensional objects made of styrofoam (sphere, cylinder, cuboids) or folded paper (convex, concave, planar) and found that bees can easily discriminate between these stimuli. We also tested possible strategies employed by the bees to uncover the depth profiles. For the card stimuli, we excluded overall shape and pictorial features (shading, texture gradients) as cues for discrimination. Lacking sufficient stereo vision, bees are known to use speed gradients in optic flow to detect edges; could the bees apply this strategy also to recover the fine details of a surface depth profile? Analysing the bees' flight tracks in front of the stimuli revealed specific combinations of flight maneuvers (lateral translations in combination with yaw rotations), which are particularly suitable to extract depth cues from motion parallax. We modelled the generated optic flow and found characteristic patterns of angular displacement corresponding to the depth profiles of our stimuli: optic flow patterns from pure translations successfully recovered depth relations from the magnitude of angular displacements, additional rotation provided robust depth information based on the direction of the displacements; thus, the bees flight maneuvers may reflect an optimized visuo-motor strategy to extract depth structure from motion signals. The robustness and simplicity of this strategy offers an efficient solution for 3D-object-recognition without stereo vision, and could be employed by other flying insects, or mobile robots.

LABOR DISCRIMINATION IN BULGARIA

Directory of Open Access Journals (Sweden)

Vyara Slavyanska

2017-03-01

Full Text Available Labor discrimination is a phenomenon with very serious social and economic consequences, which has increased actuality and importance in Bulgaria nowadays. Because of the high price of discrimination, building effective anti-discrimination legislation occupies a special place in the policy of the European Union. Despite the European directives, the presence of anti-discrimination legislation and the broadly declared anti-discrimination inclinations in our country, these are absolutely not enough for providing environment of equality, with a climate of respect and tolerance to the differences. It turns out that certain groups are definitely victims of labor discrimination. In this connection the present article consecutively identifies these groups, as well as the reasons for their discrimination, underlining the necessity and benefits of the integration of the different.

Event Shape Analysis in ALICE

CERN Document Server

AUTHOR|(CDS)2073367; Paic, Guy

2009-01-01

The jets are the final state manifestation of the hard parton scattering. Since at LHC energies the production of hard processes in proton-proton collisions will be copious and varied, it is important to develop methods to identify them through the study of their final states. In the present work we describe a method based on the use of some shape variables to discriminate events according their topologies. A very attractive feature of this analysis is the possibility of using the tracking information of the TPC+ITS in order to identify specific events like jets. Through the correlation between the quantities: thrust and recoil, calculated in minimum bias simulations of proton-proton collisions at 10 TeV, we show the sensitivity of the method to select specific topologies and high multiplicity. The presented results were obtained both at level generator and after reconstruction. It remains that with any kind of jet reconstruction algorithm one will confronted in general with overlapping jets. The present meth...

Associations between sickness absence and harassment, threats, violence, or discrimination: a cross-sectional study of the Swedish Police.

Science.gov (United States)

Svedberg, Pia; Alexanderson, Kristina

2012-01-01

To study if sick leave among employees in the Swedish Police was associated with experiences of discrimination, harassment, or (threats of) violence. All employees in the Swedish Police in 2005. Analyses of data from a questionnaire to all employees; 74% (n=16,725) responded. Odds ratios (OR) with 95% confidence intervals (CI) between sick leave and the studied factors were assessed. The rate of sickness absence was higher for women (12%) than for men (8%) (pmen had experienced discrimination, while more men reported harassment from the public and experiences of threats or violence. ORs were significant between sick-leave and discrimination, sexual harassment, and violence, and higher for the men. Associations between harassment from the public, threats of violence or violence, and sickness absence were statistically significant for men only. The study identifies the importance of investigating discrimination, harassment, and violence in relation to health outcomes for both male and female Police employees.

Experimental study of thermo-mechanical behavior of a thermosetting shape-memory polymer

Science.gov (United States)

Liu, Ruoxuan; Li, Yunxin; Liu, Zishun

2018-01-01

The thermo-mechanical behavior of shape-memory polymers (SMPs) serves for the engineering applications of SMPs. Therefore the understanding of thermo-mechanical behavior of SMPs is of great importance. This paper investigates the influence of loading rate and loading level on the thermo-mechanical behavior of a thermosetting shape-memory polymer through experimental study. A series of cyclic tension tests and shape recovery tests at different loading conditions are performed to study the strain level and strain rate effect. The results of tension tests show that the thermosetting shape-memory polymer will behave as rubber material at temperature lower than the glass transition temperature (Tg) and it can obtain a large shape fix ratio at cyclic loading condition. The shape recovery tests exhibit that loading rate and loading level have little effect on the beginning and ending of shape recovery process of the thermosetting shape-memory polymer. Compared with the material which is deformed at temperature higher than Tg, the material deformed at temperature lower than Tg behaves a bigger recovery speed.

Implicit self-other discrimination affects the interplay between multisensory affordances of mental representations of faces.

Science.gov (United States)

Zeugin, David; Arfa, Norhan; Notter, Michael; Murray, Micah M; Ionta, Silvio

2017-08-30

Face recognition is an apparently straightforward but, in fact, complex ability, encompassing the activation of at least visual and somatosensory representations. Understanding how identity shapes the interplay between these face-related affordances could clarify the mechanisms of self-other discrimination. To this aim, we exploited the so-called "face inversion effect" (FIE), a specific bias in the mental rotation of face images (of other people): with respect to inanimate objects, face images require longer time to be mentally rotated from the upside-down. Via the FIE, which suggests the activation of somatosensory mechanisms, we assessed identity-related changes in the interplay between visual and somatosensory affordances between self- and other-face representations. Methodologically, to avoid the potential interference of the somatosensory feedback associated with musculoskeletal movements, we introduced the tracking of gaze direction to record participants' response. Response times from twenty healthy participants showed the larger FIE for self- than other-faces, suggesting that the impact of somatosensory affordances on mental representation of faces varies according to identity. The present study lays the foundations of a quantifiable method to implicitly assess self-other discrimination, with possible translational benefits for early diagnosis of face processing disturbances (e.g. prosopagnosia), and for neurophysiological studies on self-other discrimination in ethological settings. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of the particle discriminator for producing the microporous nuclear track etched membrane

International Nuclear Information System (INIS)

Thongphud, Apaporn; Ratanatongchai, Wichian; Supaphol, Pitt; Visal-athaphand, Pinpan

2005-10-01

The particle discriminator was used to focus the fission fragments from nuclear fission reaction between thermal neutron from the Thai Research Reactor and U-235 in uranium screen to strike almost normally to the polycarbonate (PC) film. The latent tracks in the thin 15 mm PC film were revealed after etching in 6N NaOH solution at 70 o C for 60 min. It was found that the tracks were porous. The porosity was more discrete and the pore shape was more circular as well. The track diameter was measured 3.73 +- 0.32 mm. It was also found that using particle discriminators with increasing thickness during exposure gives fewer pores in the PC film, after chemical etching under the same condition as above

NEIGHBOURHOOD POVERTY, PERCEIVED DISCRIMINATION AND CENTRAL ADIPOSITY IN THE USA: INDEPENDENT ASSOCIATIONS IN A REPEATED MEASURES ANALYSIS.

Science.gov (United States)

Kwarteng, Jamila L; Schulz, Amy J; Mentz, Graciela B; Israel, Barbara A; Shanks, Trina R; Perkins, Denise White

2016-11-01

This study examines the independent effects of neighbourhood context (i.e. neighbourhood poverty) and exposure to perceived discrimination in shaping risk of obesity over time. Weighted three-level hierarchical linear regression models for a continuous outcome were used to assess the independent effects of neighbourhood poverty and perceived discrimination on obesity over time in a sample of 157 non-Hispanic Black, non-Hispanic White and Hispanic adults in Detroit, USA, in 2002/2003 and 2007/2008. Independent associations were found between neighbourhood poverty and perceived discrimination with central adiposity over time. Residents of neighbourhoods with high concentrations of poverty were more likely to show increases in central adiposity compared with those in neighbourhoods with lower concentrations of poverty. In models adjusted for BMI, neighbourhood poverty at baseline was associated with a greater change in central adiposity among participants who lived in neighbourhoods in the second (B=3.79, p=0.025) and third (B=3.73, p=0.024) poverty quartiles, compared with those in the lowest poverty neighbourhoods. The results from models that included both neighbourhood poverty and perceived discrimination showed that both were associated with increased risk of increased central adiposity over time. Residents of neighbourhoods in the second (B=9.58, ppoverty were more likely to show greater increases in central adiposity over time, compared with those in the lowest poverty quartile, with mean discrimination at baseline independently and positively associated with increases in central adiposity over time (B=2.36, p=0.020). The results suggest that neighbourhood poverty and perceived discrimination are independently associated with a heightened risk of increase in central adiposity over time. Efforts to address persistent disparities in central adiposity in the USA should include strategies to reduce high concentrations of neighbourhood poverty as well as

A Study of Employment Discrimination against Women in China from a Comparative Perspective

OpenAIRE

Wei, Nana

2016-01-01

This thesis is intended to focus on the employment discrimination against women in China. Firstly, the thesis will set forth the research background, including the research questions, literature review, theoretical orientations and methodology. Secondly, it will describe the current situation of employment discrimination against women in China, and analyze the reasons from the economic, social, cultural and legal aspects. Thirdly, it will analyze current anti-discrimination legislation and en...

Monostatic Radar Cross Section Estimation of Missile Shaped Object Using Physical Optics Method

Science.gov (United States)

Sasi Bhushana Rao, G.; Nambari, Swathi; Kota, Srikanth; Ranga Rao, K. S.

2017-08-01

Stealth Technology manages many signatures for a target in which most radar systems use radar cross section (RCS) for discriminating targets and classifying them with regard to Stealth. During a war target’s RCS has to be very small to make target invisible to enemy radar. In this study, Radar Cross Section of perfectly conducting objects like cylinder, truncated cone (frustum) and circular flat plate is estimated with respect to parameters like size, frequency and aspect angle. Due to the difficulties in exactly predicting the RCS, approximate methods become the alternative. Majority of approximate methods are valid in optical region and where optical region has its own strengths and weaknesses. Therefore, the analysis given in this study is purely based on far field monostatic RCS measurements in the optical region. Computation is done using Physical Optics (PO) method for determining RCS of simple models. In this study not only the RCS of simple models but also missile shaped and rocket shaped models obtained from the cascaded objects with backscatter has been computed using Matlab simulation. Rectangular plots are obtained for RCS in dbsm versus aspect angle for simple and missile shaped objects using Matlab simulation. Treatment of RCS, in this study is based on Narrow Band.

Simpson's Paradox: A Data Set and Discrimination Case Study Exercise

Science.gov (United States)

Taylor, Stanley A.; Mickel, Amy E.

2014-01-01

In this article, we present a data set and case study exercise that can be used by educators to teach a range of statistical concepts including Simpson's paradox. The data set and case study are based on a real-life scenario where there was a claim of discrimination based on ethnicity. The exercise highlights the importance of performing…

Pulse shape discrimination properties of Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12}:Ce,B single crystal in comparison with CsI:Tl

Energy Technology Data Exchange (ETDEWEB)

Rawat, S. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Department of Physics, Indian Institute of Technology, Roorkee 247667 (India); Tyagi, Mohit [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Netrakanti, P.K.; Kashyap, V.K.S.; Mitra, A. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, A.K.; Desai, D.G. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, G. Anil [Department of Physics, Indian Institute of Technology, Roorkee 247667 (India); Gadkari, S.C. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2016-12-21

Single crystals of Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12}:Ce,B and CsI:Tl were grown by Czochralski and Bridgman techniques, respectively. While both the crystals exhibited similar emission at about 550 nm, their scintillation decay times showed significantly different characteristics. The average scintillation decay time of Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12}:Ce,B crystal was found to be about 284 ns for alpha excitation compared to 108 ns measured for a gamma source. On the other hand in CsI:Tl crystals, the alpha excitation resulted in a lower average decay time of 600 ns compared to 1200 ns with gamma excitation. Their pulse shape discrimination (PSD) for gamma and alpha radiations were studied by coupling the scintillators with photomultiplier tube or SiPM and employing an advanced digitizer as well as a conventional zero-crossing setup. In spite of having a poor α/γ light yield ratio, the PSD figure of merit and the difference of zero-crossing time in Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12}:Ce,B crystals were found to be superior in comparison to CsI:Tl crystals.

Discriminability and dimensionality effects in visual search for featural conjunctions: a functional pop-out.

Science.gov (United States)

Dehaene, S

1989-07-01

Treisman and Gelade's (1980) feature-integration theory of attention states that a scene must be serially scanned before the objects in it can be accurately perceived. Is serial scanning compatible with the speed observed in the perception of real-world scenes? Most real scenes consist of many more dimensions (color, size, shape, depth, etc.) than those generally found in search paradigms. Furthermore, real objects differ from each other along many of these dimensions. The present experiment assessed the influence of the total number of dimensions and target/distractor discriminability (the number of dimensions that suffice to separate a target from distractors) on search times for a conjunction of features. Search was always found to be serial. However, for the most discriminable targets, search rate was so fast that search times were in the same range as pop-out detection times. Apparently, greater discriminability enables subjects to direct attention at a faster rate and at only a fraction of the items in a scene.

Perceived Discrimination as a Risk Factor for Use of Emerging Tobacco Products: More Similarities Than Differences Across Demographic Groups and Attributions for Discrimination.

Science.gov (United States)

Unger, Jennifer B

2018-01-17

Perceived discrimination has been associated with cigarette smoking and other substance use among members of disadvantaged minority groups. However, most studies have focused on a single minority group, have not considered the individual's attribution for the discrimination, and have not considered emerging tobacco products. This study examined the associations between perceived discrimination and use of six tobacco products (cigarettes, e-cigarettes, cigars, pipe tobacco, hookah, and smokeless tobacco) in a diverse sample of 1,068 adults in the United States. Participants were recruited on Amazon's Mechanical Turk and participated in an online survey. Logistic regression models were used to examine the association between perceived discrimination and use of each tobacco product. Interactions between discrimination and demographic characteristics, and between discrimination and perceived reasons for discrimination, were evaluated. Controlling for age, sex, race/ethnicity, education, and socioeconomic status, perceived discrimination was a risk factor for current use of five of the six tobacco products. These associations were consistent across racial/ethnic groups and regardless of the individual's attribution for the reason for the discrimination. Results indicate that perceived discrimination is a risk factor for the use of multiple tobacco products, and that this association is not limited to particular demographic groups or types of discrimination. Public health programs could potentially reduce tobacco-related disease by teaching healthier ways to cope with discrimination.

The Oval Female Facial Shape--A Study in Beauty.

Science.gov (United States)

Goodman, Greg J

2015-12-01

Our understanding of who is beautiful seems to be innate but has been argued to conform to mathematical principles and proportions. One aspect of beauty is facial shape that is gender specific. In women, an oval facial shape is considered attractive. To study the facial shape of beautiful actors, pageant title winners, and performers across ethnicities and in different time periods and to construct an ideal oval shape based on the average of their facial shape dimensions. Twenty-one full-face photographs of purportedly beautiful female actors, performers, and pageant winners were analyzed and an oval constructed from their facial parameters. Only 3 of the 21 faces were totally symmetrical, with the most larger in the left upper and lower face. The average oval was subsequently constructed from an average bizygomatic distance (horizontal parameter) of 4.3 times their intercanthal distance (ICD) and a vertical dimension that averaged 6.3 times their ICD. This average oval could be fitted to many of the individual subjects showing a smooth flow from the forehead through temples, cheeks, jaw angle, jawline, and chin with all these facial aspects abutting the oval. Where they did not abut, treatment may have improved these subjects.

Design of nuclear pulse shaped circuit based on proportional counter

International Nuclear Information System (INIS)

Song Qianqian; Cheng Yi; Tuo Xianguo

2011-01-01

Use the self-developed proportional to sample gas tritium in environment and make the measurement. For this detector, a kind of pulse shape circuit based on second order active low pass filtering circuit realized filtering and shaping nuclear pulse by high-speed operational amplifier, with less stages that has been approved for filter Gaussian wave. Use Multisim 10.0 to simulate the different parameters of the filter circuit. The simulation result was consistent with the theoretical results. The experiments proved the feasibility of this circuit, and at the same time provided a convenient and reliable method for analysis and optimization of the nuclear pulse waveform in order for discriminating by MCA. (authors)

Experienced discrimination in home mortgage lending

DEFF Research Database (Denmark)

Secchi, Davide; Seri, Raffaello

2017-01-01

This article proposes a framework for the analysis of experienced discrimination in home mortgages. It addresses the problem of home mortgage lending discrimination in one of the richest areas of northern Italy. Employees of a local hospital were interviewed to study their perception (or experien...

The combined effects of genetic risk and perceived discrimination on blood pressure among African Americans in the Jackson Heart Study.

Science.gov (United States)

Taylor, Jacquelyn Y; Sun, Yan V; Barcelona de Mendoza, Veronica; Ifatunji, Mosi; Rafferty, Jane; Fox, Ervin R; Musani, Solomon K; Sims, Mario; Jackson, James S

2017-10-01

Both genomics and environmental stressors play a significant role in increases in blood pressure (BP). In an attempt to further explain the hypertension (HTN) disparity among African Americans (AA), both genetic underpinnings (selected candidate genes) and stress due to perceived racial discrimination (as reported in the literature) have independently been linked to increased BP among AAs. Although Gene x Environment interactions on BP have been examined, the environmental component of these investigations has focused more on lifestyle behaviors such as smoking, diet, and physical activity, and less on psychosocial stressors such as perceived discrimination.The present study uses candidate gene analyses to identify the relationship between Everyday Discrimination (ED) and Major Life Discrimination (MLD) with increases in systolic BP (SBP) and diastolic BP (DBP) among AA in the Jackson Heart Study. Multiple linear regression models reveal no association between discrimination and BP after adjusting for age, sex, body mass index (BMI), antihypertensive medication use, and current smoking status.Subsequent candidate gene analysis identified 5 SNPs (rs7602215, rs3771724, rs1006502, rs1791926, and rs2258119) that interacted with perceived discrimination and SBP, and 3 SNPs (rs2034454, rs7602215, and rs3771724) that interacted with perceived discrimination and DBP. Most notably, there was a significant SNP × discrimination interaction for 2 SNPs on the SLC4A5 gene: rs3771724 (MLD: SBP P = .034, DBP P = .031; ED: DBP: P = .016) and rs1006502 (MLD: SBP P = .034, DBP P = .030; ED: DBP P = .015).This study supports the idea that SNP × discrimination interactions combine to influence clinically relevant traits such as BP. Replication with similar epidemiological samples is required to ascertain the role of genes and psychosocial stressors in the development and expression of high BP in this understudied population.

Locomotor activity and discriminative stimulus effects of a novel series of synthetic cathinone analogs in mice and rats.

Science.gov (United States)

Gatch, Michael B; Dolan, Sean B; Forster, Michael J

2017-04-01

Recent years have seen an increase in the recreational use of novel, synthetic psychoactive substances. There are little or no data on the abuse liability of many of the newer compounds. The current study investigated the discriminative stimulus and locomotor effects of a series of synthetic analogs of cathinone: α-pyrrolidinopropiophenone (α-PPP), α-pyrrolidinohexiophenone (α-PHP), α-pyrrolidinopentiothiophenone (α-PVT), 3,4-methylenedioxybutiophenone (MDPBP), and ethylone. Locomotor activity was assessed in an open-field assay using Swiss-Webster mice. Discriminative stimulus effects were assessed in Sprague-Dawley rats trained to discriminate either cocaine or methamphetamine from vehicle. Each of the compounds produced an inverted-U dose-effect on locomotor activity. Maximal effects were similar among the test compounds, but potencies varied with relative potencies of MDPBP > α-PPP = α-PHP > ethylone > α-PVT. Each of the test compounds substituted fully for the discriminative stimulus effects of methamphetamine. α-PPP, α-PHP, and ethylone fully substituted for cocaine. α-PVT produced a maximum of 50% cocaine-appropriate responding, and MDPBP produced an inverted-U-shaped dose-effect curve with maximum effects of 67%. These data provide initial evidence that these structurally similar, emerging novel psychoactive substances demonstrate potential for abuse and may be utilized for their stimulant-like effects, given their ability to stimulate locomotor activity and their substitution for the discriminative stimulus effects of the classical psychostimulants cocaine and/or methamphetamine.

Mapping the X-shaped Milky Way Bulge

Science.gov (United States)

Saito, R. K.; Zoccali, M.; McWilliam, A.; Minniti, D.; Gonzalez, O. A.; Hill, V.

2011-09-01

We analyzed the distribution of the red clump (RC) stars throughout the Galactic bulge using Two Micron All Sky Survey data. We mapped the position of the RC in 1 deg2 fields within the area |l| RC seen in the central area splits into two components at high Galactic longitudes in both hemispheres, produced by two structures at different distances along the same line of sight. The X-shape is clearly visible in the Z-X plane for longitudes close to the l = 0° axis. Crude measurements of the space densities of RC stars in the bright and faint RC populations are consistent with the adopted RC distances, providing further supporting evidence that the X-structure is real, and that there is approximate front-back symmetry in our bulge fields. We conclude that the Milky Way bulge has an X-shaped structure within |l| <~ 2°, seen almost edge-on with respect to the line of sight. Additional deep near-infrared photometry extending into the innermost bulge regions combined with spectroscopic data is needed in order to discriminate among the different possibilities that can cause the observed X-shaped structure.

Device for the track useful signal discrimination during the image scanning form bubble chambers

International Nuclear Information System (INIS)

Osipov, E.A.; Uvarov, V.A.

1976-01-01

A device for the image processing from the bubble chambers, developed to increase the reliability of the track useful signal discrimination at the image scanning from the background component is described. The device consists of a low-pass filter, repetition and memory circuit and subtraction circuit. Besides a delay line and extra channel consisting of a differentiating circuit in series with the selective shaping circuit are introduced into the device. The output signal of the selective shaping is the controlling signal of the repetition and memory circuit, at the output of which a signal corresponding the background component is formed. The functional diagram of the device operation is presented

Perceived discrimination is associated with reduced breast and cervical cancer screening: the Study of Women's Health Across the Nation (SWAN).

Science.gov (United States)

Jacobs, Elizabeth A; Rathouz, Paul J; Karavolos, Kelly; Everson-Rose, Susan A; Janssen, Imke; Kravitz, Howard M; Lewis, Tené T; Powell, Lynda H

2014-02-01

Racial disparities in breast and cervical cancer screening have been documented in African American, Hispanic, and Asian populations. Perceived discrimination may contribute to this disparity. The aim of this study was to understand the relationship between perceived everyday racial/ethnic and other discrimination and receipt of breast and cervical cancer screening in a multiethnic population of women. We analyzed data from 3,258 women participating in the Study of Women's Health Across the Nation (SWAN), a multiethnic/racial, longitudinal cohort study of the natural history of the menopausal transition conducted at seven U.S. sites. Participants completed a validated measure of perceived discrimination and reasons for believing that they were treated differently, along with Pap smears, clinical breast exams (CBE), and mammography at each follow-up period. We used multiple logistic regression for the binary outcomes of having a Pap smear, CBE, or mammogram in each of the two follow-up years, using self-reported "race discrimination" and "other discrimination" at baseline as the main predictors. African American women reported the highest percentage of racial discrimination (35%), followed by Chinese (20%), Hispanic (12%), Japanese (11%), and non-Hispanic white women (3%). Non-Hispanic white women reported the highest percentage of "other" discrimination (40%), followed by Chinese (33%), African American (24%), Japanese (23%), and Hispanic women (16%). Perceived racial discrimination was not associated with reduced receipt of preventive screening, except in one fully adjusted model. Reported discrimination owing to "other" reasons, such as age or gender, was associated with reduced receipt of Pap smear (odds ratio [OR] 0.85; 95% confidence interval [CI] 0.74-0.99), CBE (OR 0.78; 95% CI 0.67-0.91), and mammography (OR 0.80; 95% CI 0.69-0.92) regardless of patient race. Perceived discrimination is an important issue across racial/ethnic groups and is negatively

[Comment on] Statistical discrimination

Science.gov (United States)

Chinn, Douglas

In the December 8, 1981, issue of Eos, a news item reported the conclusion of a National Research Council study that sexual discrimination against women with Ph.D.'s exists in the field of geophysics. Basically, the item reported that even when allowances are made for motherhood the percentage of female Ph.D.'s holding high university and corporate positions is significantly lower than the percentage of male Ph.D.'s holding the same types of positions. The sexual discrimination conclusion, based only on these statistics, assumes that there are no basic psychological differences between men and women that might cause different populations in the employment group studied. Therefore, the reasoning goes, after taking into account possible effects from differences related to anatomy, such as women stopping their careers in order to bear and raise children, the statistical distributions of positions held by male and female Ph.D.'s ought to be very similar to one another. Any significant differences between the distributions must be caused primarily by sexual discrimination.

A comparison of different discrimination parameters for the DFT-based PSD method in fast scintillators

International Nuclear Information System (INIS)

Liu, G.; Yang, J.; Luo, X.L.; Lin, C.B.; Peng, J.X.; Yang, Y.

2013-01-01

Although the discrete Fourier transform (DFT) based pulse shape discrimination (PSD) method, realized by transforming the digitized scintillation pulses into frequency coefficients by using DFT, has been proven to effectively discriminate neutrons and γ rays, its discrimination performance depends strongly on the selection of the discrimination parameter obtained by the combination of these frequency coefficients. In order to thoroughly understand and apply the DFT-based PSD in organic scintillation detectors, a comparison of three different discrimination parameters, i.e. the amplitude of zero-frequency component, the amplitude difference between the amplitude of zero-frequency component and the amplitude of base-frequency component, and the ratio of the amplitude of base-frequency component to the amplitude of zero-frequency component, is described in this paper. An experimental setup consisting of an Americium–Beryllium (Am–Be) source, a BC501A liquid scintillator detector, and a 5Gsample/s 8-bit oscilloscope was built to assess the performance of the DFT-based PSD with each of these discrimination parameters in terms of the figure-of-merit (based on the separation of the event distributions). The third technique, which uses the ratio of the amplitude of base-frequency component to the amplitude of zero-frequency component as the discrimination parameter, is observed to provide the best discrimination performance in this research. - Highlights: • The spectrum difference between neutron pulse and γ-ray pulse was investigated. • The DFT-based PSD with different parameter definitions was assessed. • The way of using the ratio of magnitude spectrum provides the best performance. • The performance differences were explained from noise suppression features

Socially-Tolerable Discrimination

OpenAIRE

Amegashie, J. Atsu

2008-01-01

History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

Discrimination and psychiatric disorders among older African Americans.

Science.gov (United States)

Mouzon, Dawne M; Taylor, Robert Joseph; Keith, Verna M; Nicklett, Emily J; Chatters, Linda M

2017-02-01

This study examined the impact of everyday discrimination (both racial and non-racial) on the mental health of older African Americans. This analysis is based on the older African American subsample of the National Survey of American Life (NSAL) (n = 773). We examined the associations between everyday discrimination and both general distress and psychiatric disorders as measured by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Six dependent variables were examined: lifetime mood disorders, lifetime anxiety disorders, any lifetime disorder, number of lifetime disorders, depressive symptoms as measured by the 12-item Center for Epidemiological Scale of Depression (CES-D), and serious psychological distress as measured by the Kessler 6 (K6). Overall, racial and non-racial everyday discrimination were consistently associated with worse mental health for older African Americans. Older African Americans who experienced higher levels of overall everyday discrimination had higher odds of any psychiatric disorder, any lifetime mood disorder, any lifetime anxiety disorder, and more lifetime DSM-IV disorders, in addition to elevated levels of depressive symptoms and serious psychological distress. These findings were similar for both racial discrimination and non-racial discrimination. This study documents the harmful association of not only racial discrimination, but also non-racial (and overall) discrimination with the mental health of older African Americans. Specifically, discrimination is negatively associated with mood and anxiety disorders as well as depressive symptoms and psychological distress. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Employment Discrimination against LGBT Utahns

OpenAIRE

Rosky, Clifford; Mallory, Christy; Smith, Jenni; Badgett, M.V. Lee

2011-01-01

This study analyzes data from a 2010 survey on the employment experiences of 939 LGBT people living in Utah.  The study found that 44% of LGB people and 66% of transgender people in Utah have experienced employment discrimination.  The data showed that employment discrimination based on sexual orientation and gender identity currently occurs in Utah, with close to 30% of LGB respondents and 45% of transgender respondents reporting that they experienced some form of workplace harassment on a w...

Study of pulse shapes in Ge detectors with PET

Energy Technology Data Exchange (ETDEWEB)

Grabmayr, Peter; Hegai, Alexander; Jochum, Josef; Schmitt, Christopher; Schuetz, Ann-Kathrin [Eberhard Karls Univeritaet Tuebingen (Germany); Collaboration: GERDA-Collaboration

2016-07-01

The Gerda collaboration aims to determine the half life of the neutrinoless double beta decay (0νββ) of {sup 76}Ge. For Phase II Gerda wants to reduce the background contribution significantly by active background-suppression techniques. One of such techniques is the pulse shape analysis of signals induced by the interaction of radiation with the detector. The pulse shapes depend not only on the energy of the interacting gamma, the geometry and field configuration but also on the location of interaction in the crystal. The waveform and the location of the interaction in the germanium can be determined by positron-emission-tomography (PET). First results of this novel pulse shape study with the PET will be presented in this talk.

REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE II STUDY

Energy Technology Data Exchange (ETDEWEB)

Fox, K; Tommy Edwards, T

2008-11-21

Twenty five glass compositions were selected for a Phase II study to assess the potential for reducing the conservatism in the nepheline discriminator. The glass compositions were restricted to regions that fell within the validation ranges of the DWPF PCCS models. In addition, the liquidus temperature model was used to restrict the glass compositions so that they could all be melted at the same temperature. The nepheline discriminator was used to force the glass compositions into regions where nepheline formation was predicted to occur. The glasses were fabricated in the laboratory and characterized for crystallization and chemical durability after both quenching and slow cooling. Chemical analysis showed that the fabricated glasses met the target compositions. Nepheline was identified in one of the quenched glasses and several of the CCC glasses. There was no clear relationship between the types of crystallization that occurred in a particular glass and its location on the Al{sub 2}O{sub 3}-Na{sub 2}O-SiO{sub 2} ternary diagram. A partitioning algorithm was used to identify trends in crystallization behavior based on glass composition. Generally, for the CCC glasses MnO influenced the crystallization of spinels and B{sub 2}O{sub 3} and SiO{sub 2} influenced the crystallization of nepheline. Measured durability responses varied from acceptable to unacceptable depending on the glass composition and type and extent of crystallization that occurred. It was not possible to identify any linear effects of composition on chemical durability performance for this set of study glasses. The results were not sufficient to recommend modification of the current nepheline discriminator at this time. It is recommended that the next series of experiments continue to focus not only on compositional regions where the PCCS models are considered applicable (i.e., the model validation ranges), but also be restricted to compositional regions where acceptable glasses are predicted to be

Tissue Discrimination by Uncorrected Autofluorescence Spectra: A Proof-of-Principle Study for Tissue-Specific Laser Surgery

Directory of Open Access Journals (Sweden)

Katja Tangermann-Gerk

2013-10-01

Full Text Available Laser surgery provides a number of advantages over conventional surgery. However, it implies large risks for sensitive tissue structures due to its characteristic non-tissue-specific ablation. The present study investigates the discrimination of nine different ex vivo tissue types by using uncorrected (raw autofluorescence spectra for the development of a remote feedback control system for tissue-selective laser surgery. Autofluorescence spectra (excitation wavelength 377 ± 50 nm were measured from nine different ex vivo tissue types, obtained from 15 domestic pig cadavers. For data analysis, a wavelength range between 450 nm and 650 nm was investigated. Principal Component Analysis (PCA and Quadratic Discriminant Analysis (QDA were used to discriminate the tissue types. ROC analysis showed that PCA, followed by QDA, could differentiate all investigated tissue types with AUC results between 1.00 and 0.97. Sensitivity reached values between 93% and 100% and specificity values between 94% and 100%. This ex vivo study shows a high differentiation potential for physiological tissue types when performing autofluorescence spectroscopy followed by PCA and QDA. The uncorrected autofluorescence spectra are suitable for reliable tissue discrimination and have a high potential to meet the challenges necessary for an optical feedback system for tissue-specific laser surgery.

Discrimination in the workplace, reported by people with major depressive disorder: a cross-sectional study in 35 countries

Science.gov (United States)

Brouwers, E P M; Mathijssen, J; Van Bortel, T; Knifton, L; Wahlbeck, K; Van Audenhove, C; Kadri, N; Chang, Ch; Goud, B R; Ballester, D; Tófoli, LF; Bello, R; Jorge-Monteiro, M F; Zäske, H; Milaćić, I; Uçok, A; Bonetto, C; Lasalvia, A; Thornicroft, G; Van Weeghel, J

2016-01-01

Objective Whereas employment has been shown to be beneficial for people with Major Depressive Disorder (MDD) across different cultures, employers’ attitudes have been shown to be negative towards workers with MDD. This may form an important barrier to work participation. Today, little is known about how stigma and discrimination affect work participation of workers with MDD, especially from their own perspective. We aimed to assess, in a working age population including respondents with MDD from 35 countries: (1) if people with MDD anticipate and experience discrimination when trying to find or keep paid employment; (2) if participants in high, middle and lower developed countries differ in these respects; and (3) if discrimination experiences are related to actual employment status (ie, having a paid job or not). Method Participants in this cross-sectional study (N=834) had a diagnosis of MDD in the previous 12 months. They were interviewed using the Discrimination and Stigma Scale (DISC-12). Analysis of variance and generalised linear mixed models were used to analyse the data. Results Overall, 62.5% had anticipated and/or experienced discrimination in the work setting. In very high developed countries, almost 60% of respondents had stopped themselves from applying for work, education or training because of anticipated discrimination. Having experienced workplace discrimination was independently related to unemployment. Conclusions Across different countries and cultures, people with MDD very frequently reported discrimination in the work setting. Effective interventions are needed to enhance work participation in people with MDD, focusing simultaneously on decreasing stigma in the work environment and on decreasing self-discrimination by empowering workers with MDD. PMID:26908523

MEASUREMENT OF RADIONUCLIDES USING ION CHROMATOGRAPHY AND FLOW-CELL SCINTILLATION COUNTING WITH PULSE SHAPE DISCRIMINATION

International Nuclear Information System (INIS)

Fjeld, R. A.; DeVol, T.A.; Leyba, J.D.

2000-01-01

Radiological characterization and monitoring is an important component of environmental management activities throughout the Department of Energy complex. Gamma-ray spectroscopy is the technology most often used for the detection of radionuclides. However, radionuclides which cannot easily be detected by gamma-ray spectroscopy, such as pure beta emitters and transuranics, pose special problems because their quantification generally requires labor intensive radiochemical separations procedures that are time consuming and impractical for field applications. This project focused on a technology for measuring transuranics and pure beta emitters relatively quickly and has the potential of being field deployable. The technology combines ion exchange liquid chromatography and on-line alpha/beta pulse shape discriminating scintillation counting to produce simultaneous alpha and beta chromatograms. The basic instrumentation upon which the project was based was purchased in the early 1990's. In its original commercial form, the instrumentation was capable of separating select activation/fission products in ionic forms from relatively pure aqueous samples. We subsequently developed the capability of separating and detecting actinides (thorium, uranium, neptunium, plutonium, americium, and curium) in less than 30 minutes (Reboul, 1993) and realized that the potential time savings over traditional radiochemical methods for isolating some of these radionuclides was significant. However, at that time, the technique had only been used for radionuclide concentrations that were considerably above environmental levels and for aqueous samples of relatively high chemical purity. For the technique to be useful in environmental applications, development work was needed in lowering detection limits; to be useful in applications involving non-aqueous matrices such as soils and sludges or complex aqueous matrices such as those encountered in waste samples, development work was needed in

The influence of discrimination and fairness on collective self-esteem.

Science.gov (United States)

Scheepers, Daan; Spears, Russell; Manstead, Antony S R; Doosje, Bertjan

2009-04-01

This article examines the influence of discrimination and fairness on collective self-esteem. Whereas social identity theory's self-esteem hypothesis emphasizes that discrimination can enhance self-esteem, the authors contend that this self-esteem advantage will actually reverse when groups are primed with the idea of engaging in a fair intergroup competition. They measured (Study 1) and manipulated (Study 2) discrimination and fairness in real (Study 1) and minimal (Study 2) groups, after which they manipulated the presence of an intergroup competition in both studies. Collective self-esteem served as the main dependent measure. Results indicated that when an intergroup competition was present or impending, previously expressed fairness (or less discrimination) was positively related to self-esteem, whereas discrimination was positively related to collective self-esteem in the absence of an intergroup competition. Results are discussed in terms of social identity theory and the importance of the broader social context for examining the relationship between discrimination and self-esteem.

Self-Reported Experiences of Discrimination and Depression in Native Hawaiians.

Science.gov (United States)

Antonio, Mapuana Ck; Ahn, Hyeong Jun; Ing, Claire Townsend; Dillard, Adrienne; Cassel, Kevin; Kekauoha, B Puni; Kaholokula, Joseph Keawe'aimoku

2016-09-01

Discrimination is an acute and chronic stressor that negatively impacts the health of many ethnic groups in the United States. Individuals who perceive increased levels of discrimination are at risk of experiencing psychological distress and symptoms of depression. No study to date has examined the relationship between perceived discrimination and mental health in Native Hawaiians. The purpose of this study is to explore the relationship between perceived discrimination and depression based on the Homestead Health Survey mailed to Native Hawaiian residents of Hawaiian Home Lands. This study also explores the role of cultural identity and how it may impact experiences of discrimination and symptoms of depression. Based on cross-sectional data obtained from 104 Native Hawaiian residents, a significant positive correlation was found between perceived discrimination and symptoms of depression (r= 0.32, Paccounting for differences in socio-demographics and degree of identification with the Native Hawaiian and American cultures. These findings are consistent with other studies that have focused on the effects of discrimination on psychological wellbeing for other ethnic minority populations.

The problem of non-discrimination in labor relations

OpenAIRE

Вишновецька, Світлана Василівна; Національний авіаційний університет; Пінчук, Ольга Борисівна; Національний авіаційний університет

2015-01-01

The problem of discrimination on the grounds of gender and age in the field of labor relations are investigated in the article. International and Ukrainian legal regulation of non-discrimination as a guarantee of the right to work was analyzed; solutions to the problem are proposed in the article. The different points of view on the concept of discrimination in labor relations were studied by the authors. It was founded that discrimination by age and gender are the most extended forms of disc...

Discrimination of nuclear-explosion and lightning electromagnetic pulse

International Nuclear Information System (INIS)

Qi Shufeng; Li Ximei; Han Shaoqing; Niu Chao; Feng Jun; Liu Daizhi

2012-01-01

The discrimination of nuclear-explosion and lightning electromagnetic pulses was studied using empirical mode decomposition and the fractal analytical method. The box dimensions of nuclear-explosion and lightning electromagnetic pulses' original signals were calculated, and the box dimensions of the intrinsic mode functions (IMFs) of nuclear-explosion and lightning electromagnetic pulses' original signals after empirical mode decomposition were also obtained. The discrimination of nuclear explosion and lightning was studied using the nearest neighbor classification. The experimental results show that, the discrimination rate of the box dimension based on the first and second IMF after the original signal empirical mode decomposition is higher than that based on the third and forth IMF; the discrimination rate of the box dimension based on the original signal is higher than that based on any IMF; and the discrimination rate based on two-dimensional and three-dimensional characters is higher and more stable than that based on one-dimensional character, besides, the discrimination rate based on three-dimensional character is over 90%. (authors)

Statistical Discrimination in a Competitive Labor Market

OpenAIRE

Jonathan B. Berk

1999-01-01

This paper studies the effect of employee job selection in a model of statistical discrimination in a competitive labor market. In an economy in which there are quality differences between groups, a surprisingly strong condition is required to guarantee discrimination against the worse qualified group --- MLRP must hold. In addition, because of the self-selection bias induced by competition, the resulting discrimination is small when compared to the magnitude of the underlying quality differe...

Spine Shape Predicts Vertebral Fractures in Postmenopausal Women

DEFF Research Database (Denmark)

de Bruijne, Marleen; Pettersen, P.C.; A. Ghosh

2008-01-01

Early diagnosis and treatment of patients at high risk of developing fragility fractures is crucial in the management of osteoporosis. The purpose of this study was to investigate whether the shape of the spine as can be observed from lateral X-rays is indicative for the risk of future development...... of fragility fractures in the spine. The study included 568 elderly women of whom 455 maintained skeletal integrity during the mean observation period of 4.8 years and 113 sustained at least one vertebral fracture in the same period. At baseline, none of the women had experienced a previous osteoporotic...... and intervertebral disks, alignment of vertebrae, and spinal curvature. The positions of the points were subsequently used as the input features to train a pattern classification system to discriminate between spines of women maintaining skeletal health and spines sustaining a fracture in the near future...

Muslim Woman Seeking Work: An English Case Study with a Dutch Comparison, of Discrimination and Achievement

Directory of Open Access Journals (Sweden)

Christopher Bagley

2017-02-01

Full Text Available The measurement of discrimination in employment is a key variable in understanding dynamics in the nature of, and change in “race relations”. Measuring such discrimination using ‘situation’ and ‘correspondence’ tests was influenced by John Rex’s sociological analyses, and earlier work, begun in America, was continued in England in the 1960s, and further replicated in Europe and America in later decades. This literature is reviewed, and the methodologies of testing for employment discrimination are discussed. Recent work in Britain and the Netherlands is considered in detail in the light of changing social structures, and the rise of Islamophobia. Manchester, apparently the city manifesting the most discrimination in Britain, is considered for a special case study, with a focus on one individual, a Muslim woman seeking intermediate level accountancy employment. Her vita was matched with that of a manifestly indigenous, white Briton. Submitted vitas (to 1043 potential employers indicated significant discrimination against the Muslim woman candidate. Results are discussed within the context of Manchester’s micro-sociology, and Muslim women’s employment progress in broader contexts. We conclude with the critical realist comment that the “hidden racism” of employment discrimination shows that modern societies continue, in several ways, to be institutionally racist, and the failure to reward legitimate aspirations of minorities may have the effect of pushing some ethnic minorities into a permanent precariat, with implications for social justice and social control in ways which may deny minority efforts to “integrate” in society’s employment systems.

DISCRIMINATION OF WOMEN IN THE LABOUR MARKET OF SR AND MODELS OF DISCRIMINATION

OpenAIRE

Ján Vravec; Radovan Baèík

2012-01-01

IThe paper deals with the problem of women’s discrimination in the labour market. Significant differences, among women and men in the labour market, are especially in unemployment rate in reward system, and high horizontal and vertical segregation of women. The aspects of discrimination arise despite of existing legislation, which gender discrimination strictly prohibits. An analysis of arguments, consequences and models of women’s discrimination in the labour market can significantly help to...

Perceived discrimination: why applicants and employees expect and perceive discrimination

NARCIS (Netherlands)

Abu Ghazaleh, N.

2012-01-01

In this dissertation we have investigated perceptions of discrimination. We have shown discrimination exists in the eyes of applicants and employees and especially when from an ethnic minority group. There are psychological variables that influence these perceptions differently for minority and

Self-reported experiences of discrimination and inflammation among men and women: The multi-ethnic study of atherosclerosis.

Science.gov (United States)

Kershaw, Kiarri N; Lewis, Tené T; Diez Roux, Ana V; Jenny, Nancy S; Liu, Kiang; Penedo, Frank J; Carnethon, Mercedes R

2016-04-01

To examine associations of lifetime and everyday discrimination with inflammation independent of sociodemographic characteristics. Cross-sectional associations of self-reported experiences of everyday discrimination and lifetime discrimination with interleukin-6 (IL-6) and C-reactive protein (CRP) were examined by gender in a multiethnic sample of 3,099 men and 3,468 women aged 45-84 years. Everyday discrimination, lifetime discrimination due to any attribution, and lifetime discrimination attributed to race/ethnicity were based on self-report, and IL-6 and CRP were assayed from blood samples. Among women, higher levels of all 3 discrimination measures were significantly associated with higher IL-6 in models adjusted for sociodemographic characteristics, recent infection, anti-inflammatory medication use, and hormone replacement therapy use. All associations were attenuated with adjustment for body mass index (BMI). For men, everyday discrimination was inversely associated with IL-6 in all adjusted models. Lifetime discrimination was not related to IL-6 among men. Discrimination was unassociated with CRP in all models for both men and women. The association between discrimination and inflammation varied by gender and marker of inflammation. These findings highlight the complex relationship between discrimination and cardiovascular disease (CVD) risk and point to areas in need of further research. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Factorization and shape-function effects in inclusive B-meson decays

International Nuclear Information System (INIS)

Bosch, S.W.; Lange, B.O.; Neubert, M.; Paz, G.

2004-01-01

Using methods of effective field theory, factorized expressions for arbitrary B-bar ->Xul-ν-bar decay distributions in the shape-function region of large hadronic energy and moderate hadronic invariant mass are derived. Large logarithms are resummed at next-to-leading order in renormalization-group improved perturbation theory. The operator product expansion is employed to relate moments of the renormalized shape function with HQET parameters such as mb, Λ-bar and λ1 defined in a new physical subtraction scheme. An analytic expression for the asymptotic behavior of the shape function is obtained, which reveals that it is not positive definite. Explicit expressions are presented for the charged-lepton energy spectrum, the hadronic invariant mass distribution, and the spectrum in the hadronic light-cone momentum P+=EH-|P->H|. A new method for a precision measurement of |Vub| is proposed, which combines good theoretical control with high efficiency and a powerful discrimination against charm background

Discrimination in the workplace, reported by people with major depressive disorder: a cross-sectional study in 35 countries.

Science.gov (United States)

Brouwers, E P M; Mathijssen, J; Van Bortel, T; Knifton, L; Wahlbeck, K; Van Audenhove, C; Kadri, N; Chang, Ch; Goud, B R; Ballester, D; Tófoli, L F; Bello, R; Jorge-Monteiro, M F; Zäske, H; Milaćić, I; Uçok, A; Bonetto, C; Lasalvia, A; Thornicroft, G; Van Weeghel, J

2016-02-23

Whereas employment has been shown to be beneficial for people with Major Depressive Disorder (MDD) across different cultures, employers' attitudes have been shown to be negative towards workers with MDD. This may form an important barrier to work participation. Today, little is known about how stigma and discrimination affect work participation of workers with MDD, especially from their own perspective. We aimed to assess, in a working age population including respondents with MDD from 35 countries: (1) if people with MDD anticipate and experience discrimination when trying to find or keep paid employment; (2) if participants in high, middle and lower developed countries differ in these respects; and (3) if discrimination experiences are related to actual employment status (ie, having a paid job or not). Participants in this cross-sectional study (N=834) had a diagnosis of MDD in the previous 12 months. They were interviewed using the Discrimination and Stigma Scale (DISC-12). Analysis of variance and generalised linear mixed models were used to analyse the data. Overall, 62.5% had anticipated and/or experienced discrimination in the work setting. In very high developed countries, almost 60% of respondents had stopped themselves from applying for work, education or training because of anticipated discrimination. Having experienced workplace discrimination was independently related to unemployment. Across different countries and cultures, people with MDD very frequently reported discrimination in the work setting. Effective interventions are needed to enhance work participation in people with MDD, focusing simultaneously on decreasing stigma in the work environment and on decreasing self-discrimination by empowering workers with MDD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Vigilance in the discrimination-stress model for Black Americans.

Science.gov (United States)

Himmelstein, Mary S; Young, Danielle M; Sanchez, Diana T; Jackson, James S

2015-01-01

Daily events of discrimination are important factors in understanding health disparities. Vigilant coping, or protecting against anticipated discrimination by monitoring and modifying behaviour, is an understudied mechanism that may link discrimination and health outcomes. This study investigates how responding to everyday discrimination with anticipatory vigilance relates to the health of Black men and women. Black adults (N = 221) from the Detroit area completed measures of discrimination, adverse life events, vigilance coping, stress, depressive symptoms and self-reported health. Vigilance coping strategies mediated the relationship between discrimination and stress. Multi-group path analysis revealed that stress in turn was associated with increased depression in men and women. Self-reported health consequences of stress differed between men and women. Vigilance coping mediates the link between discrimination and stress, and stress has consequences for health outcomes resulting from discrimination. More research is needed to understand other underlying contributors to discrimination, stress and poor health outcomes as well as to create potential interventions to ameliorate health outcomes in the face of discrimination-related stress.

Molecules as quantum shapes and how they violate P and T

International Nuclear Information System (INIS)

Balachandran, A.P.; Witt, D.M.; Simoni, A.

1992-01-01

A geometric shape is a rigid shape in n-dimensional Euclidean space. These shapes commonly occur in the Born-Oppenheimer approximation in molecular physics, and collective models of nuclei. Abelian and non-Abelian generalizations of the of the vacuum angle of gauge theories are realized in the quantum theory of shapes. In this paper, such generalizations are presented in the language of modern quantum physics and it is shown that parity, P, and time reversal, T, are violated in certain of these quantum theories. However, the combined symmetry PT of parity composed with time reversal generally remains a good symmetry, just as in gauge theories. The exceptions are the quantum theories of staggered conformations which can violate only T. The mechanism responsible for the loss of these symmetries is a generalization of the vacuum angle mechanism for the same effect. An important results of the present analysis is the demonstration that geometric shapes, molecules in the Born-Oppenheimer approximation, and nuclei in the collective model description furnish concrete systems which upon quantization discriminate between left- and right-handed coordinates even though this distinction is entirely absent in their classical descriptions

The Economics of Discrimination: Evidence from Basketball

OpenAIRE

Kahn, Lawrence M.

2009-01-01

This Chapter reviews evidence on discrimination in basketball, primarily examining studies on race but with some discussion of gender as well. I focus on discrimination in pay, hiring, and retention against black NBA players and coaches and pay disparities by gender among college coaches. There was much evidence for each of these forms of discrimination against black NBA players in the 1980s. However, there appears to be less evidence of racial compensation, hiring and retention discriminatio...