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Sample records for shape discrimination studies

  1. Pulse shape discrimination studies of Phase I Ge-detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, Andrea [MPI fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The GERmanium Detector Array experiment aims to search for the neutrinoless double beta decay (0νββ) of {sup 76}Ge by using isotopically enriched germanium crystals as source and detector simultaneously. The bare semiconductor diodes are operated in liquid argon at cryogenic temperatures in an ultra-low background environment. In addition, Gerda applies different active background reduction techniques, one of which is pulse shape discrimination studies of the current Phase I germanium detectors. The analysis of the signal time structure provides an important tool to distinguish single site events (SSE) of the ββ-decay from multi site events (MSE) of common gamma-ray background or surface events. To investigate the correlation between the signal shape and the interaction position, a new, also to the predominantly deployed closed-ended coaxial HPGe detectors applicable analysis technique has been developed. A summary of the used electronic/detector assembly is given and followed by a discussion of the performed classification procedure by means of accurate pulse shape simulations of 0νββ-like signals. Finally, the obtained results are presented along with an evaluation of the relevance for the Gerda experiment.

  2. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    , not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...

  3. 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)

  4. Study on Digital Pulse Shape Discrimination System in BF{sub 3} Detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinhyeong; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of)

    2013-10-15

    In this study, we develop the digital PSD system and discriminate the background signal of BF{sub 3}. Spectrum shapes are different according to the t{sub start} setting method, and it is favorable to set it as the certain ratio of maximum height. In future, it will be performed to vary t{sub start} point to optimize the pulse discrimination. To quantify the performance, Figure Of Merit (FOM) will be determined. For the nuclear non-proliferation and safeguards, an accurate and reliable measurement of nuclear material is essential. The nuclear material emits neutron and γ-ray, simultaneously. For the accurate detection of the nuclear material, neutron should be discriminated from γ-ray or background radiation. In previous study, N. S. Jung developed pulse shape analysis method based on NIM and CAMAC system. However, applications of other discrimination methods based on different detection modules or changing parameters are time-and-money consuming procedures in analogue systems. Today, the performance of digitizers is improved and it replaces some radiation measurement systems which require simple and portable equipment. Digital Pulse Shape Discrimination (PSD) method by using a digital oscilloscope is developed and applied to a neutron detection system by using BF{sub 3} detector in this study.

  5. Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Tomonori Kagawa

    Full Text Available A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS. Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7, extrastriate cortex (BA18, BA19, and striate cortex (BA17 activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7, extrastriate cortex (BA18, 19, and striate cortex (BA17, as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

  6. Pulse shape discrimination with scintillation detectors

    International Nuclear Information System (INIS)

    Winyard, R.A.

    A quantitative study of pulse shape discrimination with scintillation counters has been undertaken using a crossover timing technique. The scintillators investigated included experimental and commercial liquids and plastics in addition to inorganic phosphors. The versatility of the pulse shape discrimination system has been demonstrated by extending the measurements to investigate phoswiches and liquids loaded with radioactive materials and by its application to the suppression of unwanted backgrounds in delayed coincidence counting for the measurement of nuclear half-lives and isotope identification have been carried out. (author)

  7. Pulse shape discrimination with fast digitizers

    International Nuclear Information System (INIS)

    Cester, D.; Lunardon, M.; Nebbia, G.; Stevanato, L.; Viesti, G.; Petrucci, S.; Tintori, C.

    2014-01-01

    The pulse shape discrimination (PSD) between neutrons and gamma rays in liquid scintillators is studied by using the charge integration method with fast digitizers having different technical characteristics. The use of the Figure of Merit (FoM) to verify the PSD capability is discussed. The dependence of the FoM on the digitizer sampling rate and resolution is experimentally determined. The effects due to the type of source and the irradiation geometry are also evidenced and discussed

  8. Developing of CIAE2170 pulse shape discriminator

    International Nuclear Information System (INIS)

    Shen Guanren; Wuru Gongsang; Zhou Zuying; Guo Li; Gao Weixiang; Ni Hefeng; Sun Gong

    1995-01-01

    The pulse shape discriminator is very important electronics for reducing γ rays background. The CIAE2170 pulse shape discriminator is developed and is applied to the experiments on neutron and fission physics and measurements of nuclear data for more than 1500 h. It's very stable and reliable, and continually worked for more than 200 h. The main performance is carefully tested and is in the lead in china and arrived at international advanced level. Specially, the temperature stability is less than 0.10 ns/degree C in 5-45 degree C range

  9. 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.))

  10. Neutron-gamma discrimination in mixed field by pulse shape discriminator

    International Nuclear Information System (INIS)

    Sharghi Ido, A.; Shahriari, M.; Etaati, G. R.

    2009-01-01

    In this study, a pulse shape discriminator, incorporating zero-crossing method has been developed. The separate measurements with 241 Am-Be and 252 Cf sources undertaken by BC501A liquid have shown that the purposed and the common-used pulse shape discriminator's are in good agreement. The improved characteristics of the presented pulse shape discriminator are FOM=1.36 at a threshold of 60 ke Vee and 1.5μsec dead time which allows the count rates up to 50 k Hz

  11. The zebrafish world of colors and shapes: preference and discrimination.

    Science.gov (United States)

    Oliveira, Jessica; Silveira, Mayara; Chacon, Diana; Luchiari, Ana

    2015-04-01

    Natural environment imposes many challenges to animals, which have to use cognitive abilities to cope with and exploit it to enhance their fitness. Since zebrafish is a well-established model for cognitive studies and high-throughput screening for drugs and diseases that affect cognition, we tested their ability for ambient color preference and 3D objects discrimination to establish a protocol for memory evaluation. For the color preference test, zebrafish were observed in a multiple-chamber tank with different environmental color options. Zebrafish showed preference for blue and green, and avoided yellow and red. For the 3D objects discrimination, zebrafish were allowed to explore two equal objects and then observed in a one-trial test in which a new color, size, or shape of the object was presented. Zebrafish showed discrimination for color, shape, and color+shape combined, but not size. These results imply that zebrafish seem to use some categorical system to discriminate items, and distracters affect their ability for discrimination. The type of variables available (color and shape) may favor zebrafish objects perception and facilitate discrimination processing. We suggest that this easy and simple memory test could serve as a useful screening tool for cognitive dysfunction and neurotoxicological studies.

  12. 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.)

  13. Application of pulse shape discrimination in Si detector for fission ...

    Indian Academy of Sciences (India)

    Pulse shape discrimination (PSD) with totally depleted transmission type Si surface barrier detector in reverse mount has been investigated to identify fission fragments in the presence of elastic background in heavy ion-induced fission reactions by both numerical simulation and experimental studies. The PSD method is ...

  14. 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...

  15. Low level alpha activity measurements with pulse shape discrimination

    International Nuclear Information System (INIS)

    Satoh, Kaneaki; Higuchi, Hideo; Kitamura, Kiyoshi; Noguchi, Masayasu.

    1984-01-01

    Liquid scintillation counting of α rays with pulse shape discrimination was applied to the analysis of 226 Ra and 239+240 Pu in environmental samples and of α-emitters in/on a filter paper. The instrument used in this study was either a specially designed detector or a commercial liquid scintillation counter with an automatic sample changer, both of which were connected to the pulse shape discrimination circuit. The background counting rate in α energy region of 5-7 MeV was 0.01 or 0.04 cpm/MeV, respectively. The figure of merit indicating the resolving power for α- and β-particles in time spectrum was found to be 5.7 for the commercial liquid scintillation counter. (author)

  16. 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

  17. 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.

  18. 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)

  19. Low level alpha activity measurements with pulse shape discrimination

    International Nuclear Information System (INIS)

    Noguchi, Masayasu; Satoh, Kaneaki; Higuchi, Hideo.

    1984-01-01

    Pulse shape discrimination of α and β rays with liquid scintillation counting was investigated for the purpose of low level α activity measurements. Various liquid scintillators for pulse shape discrimination were examined by means of pulse rise time analysis. A new scintillator of low cost and of superior characteristics was found. The figure of merits better than 3.5 in risetime spectrum and the energy resolution better than 9% were obtained for carefully prepared samples. The background counting rate for a sample of 10 ml was reduced to 0.013 cpm/MeV in the range of α ray energy 5 to 7 MeV. (author)

  20. 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.

  1. The time course of shape discrimination in the human brain.

    Science.gov (United States)

    Ales, Justin M; Appelbaum, L Gregory; Cottereau, Benoit R; Norcia, Anthony M

    2013-02-15

    The lateral occipital cortex (LOC) activates selectively to images of intact objects versus scrambled controls, is selective for the figure-ground relationship of a scene, and exhibits at least some degree of invariance for size and position. Because of these attributes, it is considered to be a crucial part of the object recognition pathway. Here we show that human LOC is critically involved in perceptual decisions about object shape. High-density EEG was recorded while subjects performed a threshold-level shape discrimination task on texture-defined figures segmented by either phase or orientation cues. The appearance or disappearance of a figure region from a uniform background generated robust visual evoked potentials throughout retinotopic cortex as determined by inverse modeling of the scalp voltage distribution. Contrasting responses from trials containing shape changes that were correctly detected (hits) with trials in which no change occurred (correct rejects) revealed stimulus-locked, target-selective activity in the occipital visual areas LOC and V4 preceding the subject's response. Activity that was locked to the subjects' reaction time was present in the LOC. Response-locked activity in the LOC was determined to be related to shape discrimination for several reasons: shape-selective responses were silenced when subjects viewed identical stimuli but their attention was directed away from the shapes to a demanding letter discrimination task; shape-selectivity was present across four different stimulus configurations used to define the figure; LOC responses correlated with participants' reaction times. These results indicate that decision-related activity is present in the LOC when subjects are engaged in threshold-level shape discriminations. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. Analysis of pulse-shape discrimination techniques for BC501A using GHz digital signal processing

    International Nuclear Information System (INIS)

    Rooney, B.D.; Dinwiddie, D.R.; Nelson, M.A.; Rawool-Sullivan, Mohini W.

    2001-01-01

    A comparison study of pulse-shape analysis techniques was conducted for a BC501A scintillator using digital signal processing (DSP). In this study, output signals from a preamplifier were input directly into a 1 GHz analog-to-digital converter. The digitized data obtained with this method was post-processed for both pulse-height and pulse-shape information. Several different analysis techniques were evaluated for neutron and gamma-ray pulse-shape discrimination. It was surprising that one of the simplest and fastest techniques resulted in some of the best pulse-shape discrimination results. This technique, referred to here as the Integral Ratio technique, was able to effectively process several thousand detector pulses per second. This paper presents the results and findings of this study for various pulse-shape analysis techniques with digitized detector signals.

  8. Pulse shape discrimination with silicon detectors using charge and current-sensitive preamplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Hamrita, H.; Rauly, E.; Blumenfeld, Y.; Borderie, B.; Chabot, M.; Edelbruck, P.; Lavergne, L.; Le Bris, J.; Le Neindre, N.; Richard, A.; Rivet, M.F.; Scarpaci, J.A.; Barbey, S.; Becheva, E.; Bzyl, F.R.; D' Esesquelles, P.; Galichet, E.; Lalu, G.; Martinet, G.; Pierre, S. [Institut de Physique Nucleaire, IN2P3-CNRS, 91 - Orsay (France); Legou, Th.; Tillier, J.; Bocage, F.; Bougault, R.; Carniol, B.; Cussol, D.; Etasse, D.; Grevy, S.; Lopez, O.; Tamain, B.; Vient, E. [Caen Univ., LPC, IN2P3-CNRS, ENSI, 14 - Caen (France); Galichet, E. [Conservatoire National des Arts et Metier, 75 - Paris (France); Guinet, D.; Lautesse, Ph. [Villeurbanne Univ., Institut de Physique Nucleaire, IN2P3-CNRS, 69 (France); Lanzalone, G. [Catania Univ., INFN, Laboratori Nazionali del Sud and Dipartimento di Fisica e Astronomia, (Italy); Politi, G. [Catania Univ., INFN, Sezione di Catania and Dipartimento di Fisica e Astronomia (Italy); Rosato, E. [Napoli, Univ., Dipt. di Scienze Fisiche e Sezione INFN (Italy)

    2003-07-01

    For the first time shapes of current pulses from light charged particles and carbon ions are presented. Capabilities for pulse shape discrimination techniques are demonstrated. In this work, charge and current-sensitive preamplifier prototypes for nuclear structure and dynamics experiments have been developed and tested with the aim of improving PSD (pulse shape discrimination) method by studying in detail current signal shapes from particles and ions over a large energy range. Note that current signal shapes have been recently used in atomic cluster studies to identify partitions of carbon cluster fragmentation. The paper is organized as follows. Section 2 is devoted to characterization of preamplifiers. In section 3, results of on beam tests will be presented, discussed and compared to a simple simulation.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Alpha/beta pulse shape discrimination in plastic scintillation using commercial scintillation detectors

    International Nuclear Information System (INIS)

    Bagan, H.; Tarancon, A.; Rauret, G.; Garcia, J.F.

    2010-01-01

    Activity determination in different types of samples is a current need in many different fields. Simultaneously analysing alpha and beta emitters is now a routine option when using liquid scintillation (LS) and pulse shape discrimination. However, LS has an important drawback, the generation of mixed waste. Recently, several studies have shown the capability of plastic scintillation (PS) as an alternative to LS, but no research has been carried out to determine its capability for alpha/beta discrimination. The objective of this study was to evaluate the capability of PS to discriminate alpha/beta emitters on the basis of pulse shape analysis (PSA). The results obtained show that PS pulses had lower energy than LS pulses. As a consequence, a lower detection efficiency, a shift to lower energies and a better discrimination of beta and a worst discrimination of alpha disintegrations was observed for PS. Colour quenching also produced a decrease in the energy of the particles, as well as the effects described above. It is clear that in PS, the discrimination capability was correlated with the energy of the particles detected. Taking into account the discrimination capabilities of PS, a protocol for the measurement and the calculation of alpha and beta activities in mixtures using PS and commercial scintillation detectors has been proposed. The new protocol was applied to the quantification of spiked river water samples containing a pair of radionuclides ( 3 H- 241 Am or 90 Sr/ 90 Y- 241 Am) in different activity proportions. The relative errors in all determinations were lower than 7%. These results demonstrate the capability of PS to discriminate alpha/beta emitters on the basis of pulse shape and to quantify mixtures without generating mixed waste.

  14. 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

  15. 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.

  16. 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)

  17. The application of pulse shape discrimination in NE 213 to neutron spectrometry

    International Nuclear Information System (INIS)

    Perkins, L.J.; Scott, M.C.

    1979-01-01

    The use of a zero-crossing pulse shape discrimination technique to distinguish protons from alpha particles in NE 213 is described, and a theoretical analysis is performed to predict the zero crossing characteristics. It is shown that, irrespective of the particular method of pulse shape discrimination employed, the pulse shape at low energies no longer uniquely determines the particle type for electrons, protons, alpha particles or 12 C nuclei, and the general limitations of pulse shape discrimination in NE 213 are deduced. The use of an alpha discrimination technique is then discribed, enabling neutron spectra to be unfolded from the measured detector response using a differential code. (orig.)

  18. 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)

  19. 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)

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Neutron-gamma discrimination based on pulse shape discrimination in a Ce:LiCaAlF{sub 6} scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Atsushi, E-mail: a-yamazaki@nucl.nagoya-u.ac.jp [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University (Japan); Watanabe, Kenichi; Uritani, Akira [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University (Japan); Iguchi, Tetsuo [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University (Japan); Kawaguchi, Noriaki [Tokuyama Corporation (Japan); Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Kamada, Kei [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University (Japan); Fukuda, Kentaro; Suyama, Toshihisa [Tokuyama Corporation (Japan); Yoshikawa, Akira [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University (Japan); New Industry Creation Hatchery Center (NICHe), Tohoku University (Japan)

    2011-10-01

    We demonstrate neutron-gamma discrimination based on a pulse shape discrimination method in a Ce:LiCAF scintillator. We have tried neutron-gamma discrimination using a difference in the pulse shape or the decay time of the scintillation light pulse. The decay time is converted into the rise time through an integrating circuit. A {sup 252}Cf enclosed in a polyethylene container is used as the source of thermal neutrons and prompt gamma-rays. Obvious separation of neutron and gamma-ray events is achieved using the information of the rise time of the scintillation light pulse. In the separated neutron spectrum, the gamma-ray events are effectively suppressed with little loss of neutron events. The pulse shape discrimination is confirmed to be useful to detect neutrons with the Ce:LiCAF scintillator under an intense high-energy gamma-ray condition.

  5. 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.

  6. 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

  7. 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.

  8. A pulse-shape discrimination method for improving Gamma-ray spectrometry based on a new digital shaping filter

    Science.gov (United States)

    Qin, Zhang-jian; Chen, Chuan; Luo, Jun-song; Xie, Xing-hong; Ge, Liang-quan; Wu, Qi-fan

    2018-04-01

    It is a usual practice for improving spectrum quality by the mean of designing a good shaping filter to improve signal-noise ratio in development of nuclear spectroscopy. Another method is proposed in the paper based on discriminating pulse-shape and discarding the bad pulse whose shape is distorted as a result of abnormal noise, unusual ballistic deficit or bad pulse pile-up. An Exponentially Decaying Pulse (EDP) generated in nuclear particle detectors can be transformed into a Mexican Hat Wavelet Pulse (MHWP) and the derivation process of the transform is given. After the transform is performed, the baseline drift is removed in the new MHWP. Moreover, the MHWP-shape can be discriminated with the three parameters: the time difference between the two minima of the MHWP, and the two ratios which are from the amplitude of the two minima respectively divided by the amplitude of the maximum in the MHWP. A new type of nuclear spectroscopy was implemented based on the new digital shaping filter and the Gamma-ray spectra were acquired with a variety of pulse-shape discrimination levels. It had manifested that the energy resolution and the peak-Compton ratio were both improved after the pulse-shape discrimination method was used.

  9. 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.)

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. 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.)

  15. 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.))

  16. Pulse-shape Discrimination in Organic Scintillators Using the Rising Edge

    International Nuclear Information System (INIS)

    Jones, A.; Joyce, M.J.

    2013-06-01

    The possibility of discriminating between neutrons and γ rays on the basis of differences in the rising edge of corresponding pulses from organic scintillation detectors is described. It has long been known that radiation type can be discerned on the basis of subtle differences in pulse shape from a variety of detection materials, but discrimination in fast organic scintillators has long been reliant on the separation in decay face of the pulse. This can constrain pulse-shape discrimination techniques to follow after the peak amplitude of the event and they can thus be more susceptible to the effects of pile up. Furthermore, discrimination in the decay face places a fundamental limit on the time relative to the evolution of the event when discrimination can be performed and thus this can be a significant constraint on the event processing rate for high pulse-rate applications. In this paper the correspondence between established mathematical models of organic pulse shape and real events in the rising edge part of the event is investigated, and the potential for rise-time based pulse-shape discrimination in mixed-field data from organic scintillators is explored. Special nuclear materials (SNM) are of particular interest to security surveillance and based on active interrogation. Active interrogation involves neutrons hitting a material that is fissile, and detecting the emitted γ rays and neutrons to try and classify materials. Faster, more efficient and more transportable devices are being sought to help in the prevention of illicit transport of nuclear materials. SNM are difficult to detect due to high-flux γ emissions, and very low neutron signatures (authors)

  17. 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....

  18. 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.

  19. 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.)

  20. 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.

  1. 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.)

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.)

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. 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)

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.)

  2. 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)

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.)

  10. 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)

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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).

  17. 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)

  18. 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

  19. Detailed Characterization of Nuclear Recoil Pulse Shape Discrimination in the Darkside-50 Direct Dark Matter Experiment

    Science.gov (United States)

    Ludert, Erin Edkins

    While evidence of non-baryonic dark matter has been accumulating for decades, its exact nature continues to remain a mystery. Weakly Interacting Massive Particles (WIMPs) are a well motivated candidate which appear in certain extensions of the Standard Model, independently of dark matter theory. If such particles exist, they should occasionally interact with particles of normal matter, producing a signal which may be detected. The DarkSide-50 direct dark matter experiment aims to detect the energy of recoiling argon atoms due to the elastic scattering of postulated WIMPs. In order to make such a discovery, a clear understanding of both the background and signal region is essential. This understanding requires a careful study of the detector's response to radioactive sources, which in turn requires such sources may be safely introduced into or near the detector volume and reliably removed. The CALibration Insertaion System (CALIS) was designed and built for this purpose in a joint effort between Fermi National Laboratory and the University of Hawaii. This work describes the design and testing of CALIS, its installation and commissioning at the Laboratori Nazionali del Gran Sasso (LNGS) and the multiple calibration campaigns which have successfully employed it. As nuclear recoils produced by WIMPs are indistinguishable from those produced by neutrons, radiogenic neutrons are both the most dangerous class of background and a vital calibration source for the study of the potential WIMP signal. Prior to the calibration of DarkSide-50 with radioactive neutron sources, the acceptance region was determined by the extrapolation of nuclear recoil data from a separate, dedicated experiment, ScENE, which measured the distribution of the pulse shape discrimination parameter, f 90, for nuclear recoils of known energies. This work demonstrates the validity of the extrapolation of ScENE values to DarkSide-50, by direct comparison of the f90 distribution of nuclear recoils from Sc

  20. 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.)

  1. 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.)

  2. 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.

  3. 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,

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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)

  15. 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.

  16. 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.)

  17. 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...

  18. 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.)

  19. 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

  20. 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

  1. 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.

  2. 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…

  3. 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)

  4. 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)

  5. 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

  6. 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).

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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…

  17. Detailed Characterization of Nuclear Recoil Pulse Shape Discrimination in the DarkSide-50 Direct Dark Matter Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Edkins, Erin Elisabeth [Univ. of Hawaii, Honolulu, HI (United States)

    2017-05-01

    While evidence of non-baryonic dark matter has been accumulating for decades, its exact nature continues to remain a mystery. Weakly Interacting Massive Particles (WIMPs) are a well motivated candidate which appear in certain extensions of the Standard Model, independently of dark matter theory. If such particles exist, they should occasionally interact with particles of normal matter, producing a signal which may be detected. The DarkSide-50 direct dark matter experiment aims to detect the energy of recoiling argon atoms due to the elastic scattering of postulated WIMPs. In order to make such a discovery, a clear understanding of both the background and signal region is essential. This understanding requires a careful study of the detector's response to radioactive sources, which in turn requires such sources may be safely introduced into or near the detector volume and reliably removed. The CALibration Insertaion System (CALIS) was designed and built for this purpose in a j oint effort between Fermi National Laboratory and the University of Hawaii. This work describes the design and testing of CALIS, its installation and commissioning at the Laboratori Nazionali del Gran Sasso (LNGS) and the multiple calibration campaigns which have successfully employed it. As nuclear recoils produced by WIMPs are indistinguishable from those produced by neutrons, radiogenic neutrons are both the most dangerous class of background and a vital calibration source for the study of the potential WIMP signal. Prior to the calibration of DarkSide-50 with radioactive neutron sources, the acceptance region was determined by the extrapolation of nuclear recoil data from a separate, dedicated experiment, ScENE, which measured the distribution of the pulse shape discrimination parameter, $f_{90}$, for nuclear recoils of known energies. This work demonstrates the validity of the extrapolation of ScENE values to DarkSide-50, by direct comparison of the $f_{90}$ distributio n of nuclear

  18. Performance, usability and comparison of two versions of a new macular vision test: the handheld Radial Shape Discrimination test

    Directory of Open Access Journals (Sweden)

    Jae Y. Ku

    2016-11-01

    Full Text Available Background Central vision, critical for everyday tasks such as reading and driving, is impacted by age-related changes in the eye and by diseases such as age-related macular degeneration. The detection of changes in macular function is therefore important. The Radial Shape Discrimination (RSD test measures the threshold at which distortions in a radial frequency pattern can be detected and there is evidence that it is more sensitive to macular pathology than visual acuity (VA. It also provides a more quantitative measure of macular function than the commonly available Amsler grid. Recently, handheld versions of the test (hRSD in which stimuli are presented on mobile devices (e.g., Apple iPod Touch, iPhone have been developed. We investigated the characteristics of the hRSD test in healthy participants. Methods Data were collected using both three-alternative forced choice (3AFC and 4AFC versions of the hRSD test, presented on an Apple iPod Touch. For the 3AFC version, data from a single test session were available for 186 (72 male; mean ± SD age 42 ± 17y; range 16–90y healthy participants. Test-retest data were available for subgroups of participants (intra-session: N = 74; tests approximately 2 months apart: N = 30; tests 39 months apart: N = 15. The 3AFC and 4AFC versions were directly compared in 106 participants who also completed a usability questionnaire. Distance and near VA and Pelli Robson Contrast Sensitivity (CS data were collected and undilated fundoscopy performed on the majority of participants. Results Mean (±SD 3AFC hRSD threshold was −0.77 ± 0.14 logMAR, and was statistically significantly correlated with age (Pearson r = 0.35; p < 0.001. The linear regression of hRSD threshold on age had a slope of +0.0026 compared to +0.0051 for near VA (which also correlated with age: r = 0.51; p < 0.001. There were no statistically significant differences in hRSD thresholds for any of the test-retest subgroups. We

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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)

  4. 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.

  5. 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)

  6. Discriminative study of white porcelains by INAA and PIXE

    International Nuclear Information System (INIS)

    Feng, X.Q.; Feng, S.L.; Meng, F.F.; Wang, H.M.; Liu, S.S.

    2005-01-01

    The fine white porcelains of Xing Kiln, Ding Kiln and Jingxing Kiln are very similar or alike in many aspects, such as typology of the vessel, texture of the body, colors of the body and the glaze. It is difficult for the archaeologists to distinguish the provenance using traditional methods. Nuclear analytical techniques (INAA, PIXE, XRF, SRXRF) have been widely employed for the provenance study of cultural relics in recent years due to their unique advantage, i.e. capable of nondestructive analysis. The element contents in the body and glaze of white porcelain shards with known provenance were determined by INAA and PIXE. In the meanwhile blind samples were prepared and analyzed in the same way. The differences of the element abundance patterns were processed by multivariate statistical analysis. On the basis of the analytical data and the statistical results, the discriminating criteria for provenance identification are obtained and verified by the blind samples.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

    OpenAIRE

    Stubbs, Christopher; Stubbs, Alexander

    2015-01-01

    We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors 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, a...

  12. A Novel Mechanism for Color Vision: Pupil Shape and Chromatic Aberration Can Provide Spectral Discrimination for Color Blind Organisms.

    OpenAIRE

    Stubbs, Alexander L; Stubbs, Christopher William

    2016-01-01

    We present a mechanism by which organisms with only a single photoreceptor, that have a monochromatic view of the world, can achieve color discrimination. The combination of an off axis pupil and the principle of chromatic aberration (where light of different colors 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, a...

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

    Science.gov (United States)

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

    2007-09-01

    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.

  14. 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.

  15. 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.

  16. 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.

  17. Search for the neutrinoless double β-decay in GERDA phase I using a pulse shape discrimination technique

    International Nuclear Information System (INIS)

    Kirsch, Andrea

    2014-01-01

    The Germanium Detector Array (Gerda) experiment, located underground at the INFN Laboratori Nazionali del Gran Sasso (LNGS) in Italy, deploys high-purity germanium detectors to search for the neutrinoless double β-decay (0νββ) of 76 Ge. An observation of this lepton number violating process, which is expected by many extensions of the Standard Model, would not only generate a fundamental shift in our understanding of particle physics, but also unambiguously prove the neutrino to have a non-vanishing Majorana mass component. A first phase of data recording lasted from November 2011 to May 2013 - resulting in a total exposure (defined as the product of detector mass and measurement time) of 21.6 kg.yr. Within this thesis a thorough study of this data with special emphasis on the development and scrutiny of an active background suppression technique by means of a signal shape analysis has been performed. Among several investigated multivariate approaches, particularly a selection algorithm based on an artificial neural network is found to yield the best performance; i.a. the background index close to the Q-value of the 0νββ-decay could be suppressed by 45% to 1.10 -2 cts/(keV.kg.yr), while still retaining a considerably high signal survival fraction of (83±3)% leading to a significant improvement of the experimental sensitivity. The efficiency is derived by a simulation and further validated by substantiated consistency checks availing themselves of measurements taken with different calibration sources and physics data. No signal is observed and a new lower limit of T 0ν 1/2 (90%C.L.)> 2.2. 10 25 yr for the half-life of neutrinoless double β-decay of 76 Ge is established.

  18. Search for the neutrinoless double β-decay in GERDA phase I using a pulse shape discrimination technique

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, Andrea

    2014-07-09

    The Germanium Detector Array (Gerda) experiment, located underground at the INFN Laboratori Nazionali del Gran Sasso (LNGS) in Italy, deploys high-purity germanium detectors to search for the neutrinoless double β-decay (0νββ) of {sup 76}Ge. An observation of this lepton number violating process, which is expected by many extensions of the Standard Model, would not only generate a fundamental shift in our understanding of particle physics, but also unambiguously prove the neutrino to have a non-vanishing Majorana mass component. A first phase of data recording lasted from November 2011 to May 2013 - resulting in a total exposure (defined as the product of detector mass and measurement time) of 21.6 kg.yr. Within this thesis a thorough study of this data with special emphasis on the development and scrutiny of an active background suppression technique by means of a signal shape analysis has been performed. Among several investigated multivariate approaches, particularly a selection algorithm based on an artificial neural network is found to yield the best performance; i.a. the background index close to the Q-value of the 0νββ-decay could be suppressed by 45% to 1.10{sup -2} cts/(keV.kg.yr), while still retaining a considerably high signal survival fraction of (83±3)% leading to a significant improvement of the experimental sensitivity. The efficiency is derived by a simulation and further validated by substantiated consistency checks availing themselves of measurements taken with different calibration sources and physics data. No signal is observed and a new lower limit of T{sup 0ν}{sub 1/2} (90%C.L.)> 2.2. 10{sup 25} yr for the half-life of neutrinoless double β-decay of {sup 76}Ge is established.

  19. 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.

  20. Which assessment features shape students' learning? A review study

    NARCIS (Netherlands)

    Joosten-ten Brinke, Desirée; Sluijsmans, Dominique; Van der Vleuten, Cees

    2013-01-01

    Joosten-ten Brinke, D., Sluijsmans, D., & Van der Vleuten, C. (2012, 28 November). Which assessment features shape students’ learning? A review study. Presentation at the Eapril conference, Jyväskylä, Finland.

  1. 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/

  2. Shapes related to longitudinal studies of disease

    DEFF Research Database (Denmark)

    Erleben, Lene Lillemark

    investigated four different proximity markers which lead to significantly improved marker values between NC and AD after correction for whole brain and hippocampus volume. Based on the different proximity markers we have chosen the surface connectivity marker that gave the best separation to investigate......This dissertation investigates novel markers for cardiovascular diseases (CVD) and Alzheimer's disease (AD). Both CVD and AD are among the large diseases counted in morbidity and mortality in the western world, which makes them huge and increasing problems. By investigating and learning....... The first part of this dissertation studies the growth patterns of atherosclerotic calcified deposits in the lumbar aorta based on x-ray images over an 8-year time period. We have been able to find simple growth patterns that explain how the calcifications evolve. The calcifications grew on average 41 % (p...

  3. Functional magnetic resonance imaging of visual object construction and shape discrimination : relations among task, hemispheric lateralization, and gender.

    Science.gov (United States)

    Georgopoulos, A P; Whang, K; Georgopoulos, M A; Tagaris, G A; Amirikian, B; Richter, W; Kim, S G; Uğurbil, K

    2001-01-01

    We studied the brain activation patterns in two visual image processing tasks requiring judgements on object construction (FIT task) or object sameness (SAME task). Eight right-handed healthy human subjects (four women and four men) performed the two tasks in a randomized block design while 5-mm, multislice functional images of the whole brain were acquired using a 4-tesla system using blood oxygenation dependent (BOLD) activation. Pairs of objects were picked randomly from a set of 25 oriented fragments of a square and presented to the subjects approximately every 5 sec. In the FIT task, subjects had to indicate, by pushing one of two buttons, whether the two fragments could match to form a perfect square, whereas in the SAME task they had to decide whether they were the same or not. In a control task, preceding and following each of the two tasks above, a single square was presented at the same rate and subjects pushed any of the two keys at random. Functional activation maps were constructed based on a combination of conservative criteria. The areas with activated pixels were identified using Talairach coordinates and anatomical landmarks, and the number of activated pixels was determined for each area. Altogether, 379 pixels were activated. The counts of activated pixels did not differ significantly between the two tasks or between the two genders. However, there were significantly more activated pixels in the left (n = 218) than the right side of the brain (n = 161). Of the 379 activated pixels, 371 were located in the cerebral cortex. The Talairach coordinates of these pixels were analyzed with respect to their overall distribution in the two tasks. These distributions differed significantly between the two tasks. With respect to individual dimensions, the two tasks differed significantly in the anterior--posterior and superior--inferior distributions but not in the left--right (including mediolateral, within the left or right side) distribution. Specifically

  4. 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…

  5. 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

  6. 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.

  7. Particle identification using digital pulse shape discrimination in a nTD silicon detector with a 1 GHz sampling digitizer

    Science.gov (United States)

    Mahata, K.; Shrivastava, A.; Gore, J. A.; Pandit, S. K.; Parkar, V. V.; Ramachandran, K.; Kumar, A.; Gupta, S.; Patale, P.

    2018-06-01

    In beam test experiments have been carried out for particle identification using digital pulse shape analysis in a 500 μm thick Neutron Transmutation Doped (nTD) silicon detector with an indigenously developed FPGA based 12 bit resolution, 1 GHz sampling digitizer. The nTD Si detector was used in a low-field injection setup to detect light heavy-ions produced in reactions of ∼ 5 MeV/A 7Li and 12C beams on different targets. Pulse height, rise time and current maximum have been obtained from the digitized charge output of a high bandwidth charge and current sensitive pre-amplifier. Good isotopic separation have been achieved using only the digitized charge output in case of light heavy-ions. The setup can be used for charged particle spectroscopy in nuclear reactions involving light heavy-ions around the Coulomb barrier energies.

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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).

  13. 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.

  14. A Shape Optimization Study for Tool Design in Resistance Welding

    DEFF Research Database (Denmark)

    Bogomolny, Michael; Bendsøe, Martin P.; Hattel, Jesper Henri

    2009-01-01

    The purpose of this study is to apply shape optimization tools for design of resistance welding electrodes. The numerical simulation of the welding process has been performed by a simplified FEM model implemented in COMSOL. The design process is formulated as an optimization problem where...... the objective is to prolong the life-time of the electrodes. Welding parameters like current, time and electrode shape parameters are selected to be the design variables while constraints are chosen to ensure a high quality of the welding. Surrogate models based on a Kriging approximation has been used in order...

  15. 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.

  16. Study of the Auger line shape of polyethylene and diamond

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M; Pepper, S V

    1984-03-01

    The KVV Auger electron line shapes of carbon in polyethylene and diamond have been studied. The spectra were obtained in derivative form by electron beam excitation. They were treated by background subtraction, integration and deconvolution to produce the intrinsic Auger line shape. Electron energy loss spectra provided the response function in the deconvolution procedure. The line shape from polyethylene is compared with spectra from linear alkanes and with a previous spectrum of Kelber et al. Both spectra are compared with the self-convolution of their full valence band densities of states and of their p-projected densities. The experimental spectra could not be understood in terms of existing theories. This is so even when correlation effects are qualitatively taken into account according to the theories of Cini and Sawatzky and Lenselink.

  17. Stress analysis studies in optimised 'D' shaped TOKAMAK magnet designs

    International Nuclear Information System (INIS)

    Diserens, N.J.

    1975-07-01

    A suite of computer programs TOK was developed which enabled simple data input to be used for computation of magnetic fields and forces in a toroidal system of coils with either D-shaped or circular cross section. An additional requirement was that input data to the Swansea stress analysis program FINESSE could be output from the TOK fields and forces program, and that graphical output from either program should be available. A further program was required to optimise the coil shape. This used the field calculating routines from the TOK program. The starting point for these studies was the proposed 40 coil Princeton design. The stresses resulting from three different shapes of D-coil were compared. (author)

  18. 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.

  19. Incomplete contour representations and shape descriptors : ICR test studies

    NARCIS (Netherlands)

    Ghosh, Anarta; Petkov, Nicolai; Gregorio, MD; DiMaio,; Frucci, M; Musio, C

    2005-01-01

    Inspired by psychophysical studies of the human cognitive abilities we propose a novel aspect and a method for performance evaluation of contour based shape recognition algorithms regarding their robustness to incompleteness of contours. We use complete contour representations of objects as a

  20. 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

  1. 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....

  2. Time resolution studies using digital constant fraction discrimination

    International Nuclear Information System (INIS)

    Fallu-Labruyere, A.; Tan, H.; Hennig, W.; Warburton, W.K.

    2007-01-01

    Digital Pulse Processing (DPP) modules are being increasingly considered to replace modular analog electronics in medium-scale nuclear physics experiments (100-1000s of channels). One major area remains, however, where it has not been convincingly demonstrated that DPP modules are competitive with their analog predecessors-time-of-arrival measurement. While analog discriminators and time-to-amplitude converters can readily achieve coincidence time resolutions in the 300-500 ps range with suitably fast scintillators and Photomultiplier Tubes (PMTs), this capability has not been widely demonstrated with DPPs. Some concern has been expressed, in fact, that such time resolutions are attainable with the 10 ns sampling times that are presently commonly available. In this work, we present time-coincidence measurements taken using a commercially available DPP (the Pixie-4 from XIA LLC) directly coupled to pairs of fast PMTs mated with either LSO or LaBr 3 scintillator crystals and excited by 22 Na γ-ray emissions. Our results, 886 ps for LSO and 576 ps for LaBr 3 , while not matching the best literature results using analog electronics, are already well below 1 ns and fully adequate for a wide variety of experiments. These results are shown not to be limited by the DPPs themselves, which achieved 57 ps time resolution using a pulser, but are degraded in part both by the somewhat limited number of photoelectrons we collected and by a sub-optimum choice of PMT. Analysis further suggests that increasing the sampling speed would further improve performance. We therefore conclude that DPP time-of-arrival resolution is already adequate to supplant analog processing in many applications and that further improvements could be achieved with only modest efforts

  3. 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

  4. 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

  5. Study of the shape of fragmentation events in central collisions

    International Nuclear Information System (INIS)

    Nguyen, A.D.; Durand, D.; Bocage, F.; Bougault, R.; Brou, R.; Colin, J; Cussol, D.; Genouin-Duhamel, E.; Gulminelli, F.; Lecolley, J.F.; Lefort, T.; Le Neindre, N.; Lopez, O.; Louvel, M.; Peter, J.; Steckmeyer, J.C.; Tamain, B.; Vient, E.

    1997-01-01

    The study of the most central collisions resulting in the fragmentation of nuclear systems requires a precise as highly possible knowledge of the space-time configuration of matter. Particularly, it is important to be able to define the event shapes in order to estimate the equilibrium degree reached by the system in the moment of its breakup. To do that, an tensor analysis was developed end applied to data from INDRA for the system Xe + Sn at 50 MeV/u. The obtained results were compared with the predictions of the SIMON generator. The analysis indicates a quasi-sphericity of the fragmentation source. This result is a convincing evidence in favor of formation of a highly excited system in equilibrium the life-time of which is long enough to relax the shape degrees of freedom as well as the internal freedom degrees. A comparison between the experimental results corresponding to the Xe + Sn central collisions at 50 MeV/u and the predictions of a SIMON calculation for different shapes of the fragmenting source is presented as a function of the variables D and C, which are linear combinations of the eigenvalues of the tensor of the moments used for characterisation of the event shape

  6. 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…

  7. 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.

  8. 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.

  9. Study of oblate nuclear shapes and shape coexistence in neutron-deficient rare earth isotopes

    CERN Multimedia

    Guttormsen, M S; Reiter, P; Larsen, A; Korten, W; Clement, E; Siem, S; Renstrom, T; Buerger, A; Jenkins, D G

    We propose to investigate nuclear shapes and shape coexistence in neutron-deficient rare earth nuclei below the N=82 shell closure at the ISOLDE facility by employing Coulomb excitation of Nd, Sm, Gd, and Dy beams from the REX accelerator and the Miniball experiment. Nuclear shapes are expected to change rapidly in this region of the nuclear chart. The measurement of electric quadrupole moments of excited states and the transition rates between them serves as a stringent test of theoretical models and effective nucleon-nucleon interactions.

  10. 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.

  11. 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

  12. Design of the sex hormones and physical exercise (SHAPE study

    Directory of Open Access Journals (Sweden)

    Peeters Petra HM

    2007-09-01

    Full Text Available Abstract Background Physical activity has been associated with a decreased risk for breast cancer. The biological mechanismn(s underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones either direct, or indirect by preventing overweight and abdominal adiposity. In order to get more insight in the causal pathway between physical activity and breast cancer risk, we designed the Sex Hormones and Physical Exercise (SHAPE study. Purpose of SHAPE study is to examine the effects of a 1-year moderate-to-vigorous intensity exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether the amount of total body fat or abdominal fat mediates the effects. Methods/Design In the SHAPE study, 189 sedentary postmenopausal women, aged 50–69 years, are randomly allocated to an intervention or a control group. The intervention consists of an 1-year moderate-to-vigorous intensity aerobic and strenght training exercise programme. Partcipants allocated to the control group are requested to retain their habitual exercise pattern. Primary study parameters measured at baseline, at four months and at 12 months are: serum concentrations of endogenous estrogens, endogenous androgens, sex hormone binding globuline and insuline. Other study parameters include: amount of total and abdominal fat, weight, BMI, body fat distribution, physical fitness, blood pressure and lifestyle factors. Discussion This study will contribute to the body of evidence relating physical activity and breast cancer risk and will provide insight into possible mechanisms through which physical activity might be associated with reduced risk of breast cancer in postmenopausal women. Trial registration NCT00359060

  13. 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

  14. 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.

  15. 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.

  16. 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…

  17. Color-Blindness Study: Color Discrimination on the TICCIT System.

    Science.gov (United States)

    Asay, Calvin S.; Schneider, Edward W.

    The question studied whether the specific seven TICCIT system colors used within color coding schemes can be a source of confusion, or not seen at all, by the color-blind segment of target populations. Subjects were 11 color-blind and three normally sighted students at Brigham Young University. After a preliminary training exercise to acquaint the…

  18. Workplace Discrimination and Americans with Psychiatric Disabilities: A Comparative Study

    Science.gov (United States)

    An, Sunghee; Roessler, Richard T.; McMahon, Brian T.

    2011-01-01

    This study reports findings from an analysis of employment allegations and resolutions maintained in the U.S. Equal Employment Opportunity Commission (EEOC) database. Spanning the years 1992 to 2005, the data were aggregated for individuals with psychiatric disabilities and individuals with a variety of physical, sensory, and neurological…

  19. 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

  20. 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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. "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.

  4. Experience of Career-Related Discrimination for Female-to-Male Transgender Persons: A Qualitative Study

    Science.gov (United States)

    Dispenza, Franco; Watson, Laurel B.; Chung, Y. Barry; Brack, Greg

    2012-01-01

    In this qualitative study, the authors examined the experience of discrimination and its relationship to the career development trajectory of 9 female-to-male transgender persons. Participants were between 21 and 48 years old and had a variety of vocational experiences. Individual semistructured interviews were conducted via telephone and analyzed…

  5. 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.

  6. 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...

  7. 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.

  8. Studies of the shapes of heavy pear-shaped nuclei at ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Butler, P. A., E-mail: peter.butler@liverpool.ac.uk [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2016-07-07

    For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a ”pear-shape” in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that will exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.

  9. Cosmic Topology: Studying The Shape And Size Of Our Universe

    Science.gov (United States)

    Yzaguirre, Amelia; Hajian, A.

    2010-01-01

    The question of the size and the shape of our universe is a very old problem that has received considerable attention over the past few years. The simplest cosmological model predicts that the mean density of the universe is very close to the critical density, admitting a local geometry of the universe that is flat. Current results from different cosmological observations confirm this to the percent level accuracy. General Relativity (being a local theory) only determines local geometry, which allows for the possibility of a multiply connected universe with a zero (or small) curvature. To study the global shape, or topology, of the universe, one can use cosmological observations on large scales. In this project we investigate the possibility of a ``small universe'', that is, a compact finite space, by searching for planar symmetries in the CMB anisotropy maps provided by the five-year WMAP observations in two foreground cleaned maps (WMAP ILC map and the Tegmark, et al. (TOH) map ). Our results strongly suggest that the small universe model is not a viable topology for the universe.

  10. New apparatus for discriminating shapes - application to the study of neutron-proton elastic scattering at 14.6 MeV; Nouveau dispositif de discrimination de formes - Application a l'etude de la diffusion elastique neutron-proton a 14,6 MeV; Novyj diskriminator po forme - primenenie k izucheniyu uprugogo rasseyaniya nejtronproton s 14,6 MeV; Nuevo dispositivo para discriminacion de formas - Aplicacion al estudio de la dispersion elastica neutron-proton a 14,6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crettez, J P; Cambou, F; Ambrosino, G [Laboratoire Maurice de Broglie, Paris (France)

    1962-04-15

    The mean life of scintillations in caesium iodide is dependent on the nature of the ionizing particle, the shortest life corresponding to the highest ionization density. This property is utilized for distinguishing different particles producing scintillations of similar amplitude. The apparatus described is a shape discriminator. It measures the time required by the scintillation to fall from its maximum to an adjustable fraction thereof. A time-amplitude converter provides a pulse the height of which is proportional to the time so measured. A comparison is then made between the shapes of the scintillations produced by alpha particles, protons and electrons, and the results obtained are shown. Application of this method to the measurement of recoil protons set in motion in a thin hydrogenated diffuser by a neutron flux is also described. Suppression of the pulses produced by gamma rays makes it possible to deduce from the spectra obtained the variation of the differential elastic scattering cross-section in terms of the angle, for d-t reaction neutrons. (author) [French] La vie moyenne des scintillations dans l'iodure de cesium varie suivant la nature de la particule ionisante. A la plus grande densite d'ionisation correspond la vie la plus courte. Cette propriete est employee pour distinguer differentes particules produisant des scintillations d'amplitude analogue. L'appareil decrit est un discriminateur de forme. Il mesure le temps mis par la scintillation pour passer de son maximum a une fraction reglable de cette amplitude. Un convertisseur temps-amplitude fournit une impulsion dont la hauteur est proportionnelle au temps ainsi mesure. Les auteurs comparent les formes des scintillations produites par les particules a, les protons, les electrons; ils presentent les resultats obtenus. Les auteurs decrivent l'application de cette methode a la mesure des protons de recul qu'un flux de neutrons met en mouvement dans un diffuseur hydrogene mince. La suppression des

  11. Investigating shape and space in mathematics: A case study | Kotze ...

    African Journals Online (AJOL)

    Evidence was obtained regarding mathematics teachers' and mathematics learners' knowledge of space and shape. Problems experienced in concept formation in geometry were investigated and analysed. An account is provided of how teachers and learners responded to problems related to space and shape.

  12. 76 FR 59706 - Proposed Collection; Comment Request; Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2011-09-27

    ... published in scientific journals and will be used for the development of future research initiatives... Request; Healthy Communities Study: How Communities Shape Children's Health (HCS) SUMMARY: Under the... control number. Proposed Collection: Title: Healthy Communities Study: How Communities Shape Children's...

  13. 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.

  14. 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.

  15. [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

  16. Study on discriminant analysis by military mental disorder prediction scale for mental disorder of new recruits

    Directory of Open Access Journals (Sweden)

    Li-yi ZHANG

    2011-11-01

    Full Text Available Objective To examine the predictive role of the Military Mental Disorder Prediction Scale on the mental disorder of new recruits.Methods The present study examined 115 new recruits diagnosed with mental disorder and 115 healthy new recruits.The recruits were tested using the Military Mental Disorder Prediction Scale.The discriminant function was built by discriminant analysis method.The current study analyzed the predictive value of 11 factors(family medical record and past medical record(X1,growth experience(X2,introversion(X3,stressor(X4,poor mental defense(X5,social support(X6,psychosis(X7,depression(X8,mania(X9,neurosis(X10,and personality disorder(X11 aside from lie factor on the mental disorder of new recruits.Results The mental disorder group has higher total score and factor score in family medical record and past medical record,introversion,stressor,poor mental defense,social support,psychosis,depression,mania,neurosis,personality disorder,and lie than those of the contrast group(P < 0.01.For the score of growth experience factor,that of the mental disorder group is higher than the score of the contrast group(P < 0.05.All 11 factors except the lie factor in the Mental Disorder Prediction Scale are taken as independent variables by enforced introduction to obtain the Fisher linear discriminant function as follows: The mental disorder group=-7.014-0.278X1+1.556X2+1.563X3+0.878X4+0.183X5-0.845X6-0.562X7-0.353X8+1.246X9-0.505X10+1.029X11.The contrast group=-2.971+0.056X1+2.194X2+0.707X3+0.592X4-0.086X5-0.888X6-0.133X7-0.360X8+0.654X9-0.467X10+0.308X11.The discriminant function has an accuracy rate of 76.5% on the new recruits with mental disorders and 100% on the healthy new recruits.The total accurate discrimination rate is 88.3% and the total inaccurate discrimination rate is 11.7%.Conclusion The Military Mental Disorder Prediction Scale has a high accuracy rate on the prediction of mental disorder of new recruits and is worthy of

  17. 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

  18. The Impact of Handedness, Sex, and Cognitive Abilities on Left–Right Discrimination: A Behavioral Study

    Science.gov (United States)

    Constant, Martin; Mellet, Emmanuel

    2018-01-01

    The present study examined the relationship between left–right discrimination (LRD) performance and handedness, sex and cognitive abilities. In total, 31 men and 35 women – with a balanced ratio of left-and right-handers – completed the Bergen Left–Right Discrimination Test. We found an advantage of left-handers in both identifying left hands and in verifying “left” propositions. A sex effect was also found, as women had an overall higher error rate than men, and increasing difficulty impacted their reaction time more than it did for men. Moreover, sex interacted with handedness and manual preference strength. A negative correlation of LRD reaction time with visuo-spatial and verbal long-term memory was found independently of sex, providing new insights into the relationship between cognitive skills and performance on LRD. PMID:29636718

  19. The Favelas of Rio de Janeiro: A study of socio-spatial segregation and racial discrimination

    Directory of Open Access Journals (Sweden)

    OLAVARRIA BERENGUER, Leticia

    2014-05-01

    Full Text Available Race relations in Brazil are characterized by the coexistence of miscegenation (interracial social contact and racial discrimination. This paper examines to what extent Brazilian race relations are expressed in the urban space, how they inflect its physical configuration and influence the social processes that take place within it. In this sense, it states that as long as it is considered that the space is subjected to power relations it can be asserted that these dynamics are expressed in the configuration of Brazilian cities, particularly in Rio de Janeiro. Thus, the urban structure of Rio reflects certain level of interracial sociability in terms of residence and the social hyper-inequalities of Brazilian society. In addition, the study of the favelas shows how discourses about race and urban space are interconnected and reinforce racial discrimination.

  20. How discrimination and stress affects self-esteem among Dominican immigrant women: an exploratory study.

    Science.gov (United States)

    Panchanadeswaran, Subadra; Dawson, Beverly Araujo

    2011-01-01

    Understanding the factors that contribute to the health disparities among racial and ethnic minorities in the United States is very important given the growing Latina population. Although researchers have investigated the health and mental health status among Latinas, the relationship between mental health and self-esteem has not been given a lot of attention. Given that self-esteem is a proxy for mental health status, investigations exploring the factors that can negatively affect self-esteem are needed. Therefore, the current study examined the influence of discrimination and stress on self-esteem among Dominican immigrant women. A cross-sectional study was undertaken among 235 immigrant Dominican women in New York City. Women (age 18-49 years) and in the United States for fewer than 20 years were more likely to report experiencing discrimination compared to women older than age 50 years and in the United States for more than 20 years. After controlling for age, time in the United States, educational level, and income, high levels of discrimination (-0.09, p < 0.01) and stress (-0.69, p < 0.001) were significantly associated with reduced self-esteem. Interventions with Latino/a populations, especially women, need to acknowledge their individual evaluations of the discriminatory and stressful experiences that negatively influence their self-esteem and subsequently their mental health status.

  1. 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).

  2. 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

  3. Descriptive study of the Socratic method: evidence for verbal shaping.

    Science.gov (United States)

    Calero-Elvira, Ana; Froján-Parga, María Xesús; Ruiz-Sancho, Elena María; Alpañés-Freitag, Manuel

    2013-12-01

    In this study we analyzed 65 fragments of session recordings in which a cognitive behavioral therapist employed the Socratic method with her patients. Specialized coding instruments were used to categorize the verbal behavior of the psychologist and the patients. First the fragments were classified as more or less successful depending on the overall degree of concordance between the patient's verbal behavior and the therapeutic objectives. Then the fragments were submitted to sequential analysis so as to discover regularities linking the patient's verbal behavior and the therapist's responses to it. Important differences between the more and the less successful fragments involved the therapist's approval or disapproval of verbalizations that approximated therapeutic goals. These approvals and disapprovals were associated with increases and decreases, respectively, in the patient's behavior. These results are consistent with the existence, in this particular case, of a process of shaping through which the therapist modifies the patient's verbal behavior in the overall direction of his or her chosen therapeutic objectives. © 2013.

  4. Genetic explanations, discrimination and chronic illness: A qualitative study on hereditary haemochromatosis in Germany.

    Science.gov (United States)

    Manz, Ulrike

    2016-12-01

    The objective of this study is to explore the discriminatory impacts of genetic diagnosis for people living with the chronic illness of hereditary haemochromatosis in Germany. Semi-structured interviews with 15 patients; all had tested positive for a genetic mutation associated with haemochromatosis and already displayed symptoms of the disease. Inductive approach, with interviews collaboratively interpreted by the research group in a vertical and horizontal analysis informed by a multi-person perspective. First, as the genetic diagnosis of the disease holds the promise of therapeutic intervention, the interviewees perceived it as leading to relief. Second, the interviewees felt stigmatized by their family members, they complained of social isolation and a lack of acknowledgement of their health problems. Third, they feared disadvantages for themselves or their children at their place of work, when buying insurance coverage, and when attempting to donate blood. The findings point to the need for an expanded view on genetic discrimination. Besides institutional discrimination, it appears necessary to systematically address interactional stigmatization and take anxieties and fears into account. Here we see starting points for providing essential support through specialist and self-help groups to those faced with the genetic diagnosis of haemochromatosis in addition to and beyond the legal protection against genetic discrimination that already exists. © The Author(s) 2016.

  5. Perception, experience, and response to genetic discrimination in Huntington's disease: the Australian results of The International RESPOND-HD study.

    Science.gov (United States)

    Goh, Anita M Y; Chiu, Edmond; Yastrubetskaya, Olga; Erwin, Cheryl; Williams, Janet K; Juhl, Andrew R; Paulsen, Jane S

    2013-02-01

    This study examines elements of genetic discrimination among an at-risk, clinically undiagnosed Huntington's disease (HD) population. Sixty at-risk individuals, either positive or negative for the HD genetic mutation, completed a survey regarding their experiences of genetic discrimination, adverse and unfair treatment, and knowledge about existing laws and policies surrounding genetic discrimination. Sixty eight percent of participants reported feeling "Great benefit" from knowing their genetic test results. Reported benefits of knowledge included planning for the future, making decisions, and many individuals found meaning in active participation in the HD community and in advocating for themselves or families at risk for HD. Many individuals found personal meaning and a sense of community from knowledge of this information and from the ability to participate in research. Despite these positive feelings toward gene testing, results demonstrated that 33% of participants perceived experiences of genetic discrimination, which occurred repeatedly and caused great self-reported distress. Significantly, more gene-positive respondents reported experiencing incidents of genetic discrimination, compared to gene-negative respondents. At least 58 separate incidents of discrimination were reported, the number of incidents ranged from 1 to 10, with 45% of individuals (9/20 respondents) indicating more than one event. Of the most significant events of discrimination, 58% were related to insurance, 21% to employment, 16% to transactions of daily life, and 5% to relationships. Results contribute toward validation of empirical data regarding genetic discrimination.

  6. 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

  7. 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)

  8. 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

  9. 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

  10. 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.

  11. Priming in implicit memory tasks: prior study causes enhanced discriminability, not only bias.

    Science.gov (United States)

    Zeelenberg, René; Wagenmakers, Eric-Jan M; Raaijmakers, Jeroen G W

    2002-03-01

    R. Ratcliff and G. McKoon (1995, 1996, 1997; R. Ratcliff, D. Allbritton, & G. McKoon, 1997) have argued that repetition priming effects are solely due to bias. They showed that prior study of the target resulted in a benefit in a later implicit memory task. However, prior study of a stimulus similar to the target resulted in a cost. The present study, using a 2-alternative forced-choice procedure, investigated the effect of prior study in an unbiased condition: Both alternatives were studied prior to their presentation in an implicit memory task. Contrary to a pure bias interpretation of priming, consistent evidence was obtained in 3 implicit memory tasks (word fragment completion, auditory word identification, and picture identification) that performance was better when both alternatives were studied than when neither alternative was studied. These results show that prior study results in enhanced discriminability, not only bias.

  12. 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

  13. Probability shapes perceptual precision: A study in orientation estimation.

    Science.gov (United States)

    Jabar, Syaheed B; Anderson, Britt

    2015-12-01

    Probability is known to affect perceptual estimations, but an understanding of mechanisms is lacking. Moving beyond binary classification tasks, we had naive participants report the orientation of briefly viewed gratings where we systematically manipulated contingent probability. Participants rapidly developed faster and more precise estimations for high-probability tilts. The shapes of their error distributions, as indexed by a kurtosis measure, also showed a distortion from Gaussian. This kurtosis metric was robust, capturing probability effects that were graded, contextual, and varying as a function of stimulus orientation. Our data can be understood as a probability-induced reduction in the variability or "shape" of estimation errors, as would be expected if probability affects the perceptual representations. As probability manipulations are an implicit component of many endogenous cuing paradigms, changes at the perceptual level could account for changes in performance that might have traditionally been ascribed to "attention." (c) 2015 APA, all rights reserved).

  14. Does Avalanche Shovel Shape Affect Excavation Time: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Kurt Schindelwig

    2017-05-01

    Full Text Available In Europe and North America, approximately 150 fatalities occur as a result of avalanches every year. However, it is unclear whether certain shovel shapes are more effective than others in snow removal during avalanche victim recovery. The objective was to determine the performance parameters with a developed standardized test using different shovel shapes and to determine sex-specific differences. Hence, several parameters were determined for clearing the snow from a snow filled box (15 men, 14 women. A flat (F and a deep (D shovel blade with the shaft connected straight (S or in clearing mode (C were used for the investigation of the shovel shapes FS, DC and the subsequent use of DC&DS. Mean snow mass shifted per unit time increased significantly from 1.50 kg/s with FS to 1.71 kg/s (14% with DS and further to 1.79 kg/s (4% with DC&DS for all participants. Snow mass shifted per unit time was 44% higher (p < 0.05 for men than for women. In excavation operations, the sex-specific physical performance should be taken into account. The results were limited to barely binding snow, because only with this snow did the tests show a high reliability.

  15. 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.

  16. Job Strain, Workplace Discrimination, and Hypertension among Older Workers: The Health and Retirement Study.

    Science.gov (United States)

    Mezuk, Briana; Kershaw, Kiarri N; Hudson, Darrell; Lim, Kyuang Ah; Ratliff, Scott

    2011-03-01

    Job strain has been associated with hypertension among younger workers; however, whether this relationship persists among older workers, particularly older racial/ethnic minorities, is unresolved. This study evaluated whether job strain and workplace discrimination are associated with hypertension and poor blood pressure control among older workers and whether these relationships vary by gender and race/ethnicity. Data were drawn from the Health and Retirement Study, and analysis was restricted to employed participants with complete information on job strain and blood pressure (N = 3,794). In adjusted models, high job strain was associated with lower likelihood of hypertension (odds ratio (OR): 0.75, 95% confidence interval (CI): 0.63, 0.89) relative to low job strain. Stratified analyses indicated this association was only significant among white (OR: 0.71, 95% CI: 0.58, 0.86) and male (OR: 0.61, 95% CI: 0.47, 0.79) workers. High job strain was not significantly associated with hypertension among African American (OR: 1.14, 95% CI: 0.63, 2.07) or Hispanic (OR: 0.56, 95% CI: 0.29, 1.09) workers. Workplace discrimination was not associated with hypertension among any group. Neither job strain nor discrimination was associated with poor blood pressure control. These findings suggest that persistence in work characterized by high job strain in later life may signal resilience to the influence of work-related stressors on health. Future research efforts should examine the factors that contribute to gender and racial differences in these relationships.

  17. 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

  18. 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

  19. 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/

  20. 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

  1. Spectral discrimination of giant reed (Arundo donax L.): A seasonal study in riparian areas

    Science.gov (United States)

    Fernandes, Maria Rosário; Aguiar, Francisca C.; Silva, João M. N.; Ferreira, Maria Teresa; Pereira, José M. C.

    2013-06-01

    The giant reed (Arundo donax L.) is amongst the one hundred worst invasive alien species of the world, and it is responsible for biodiversity loss and failure of ecosystem functions in riparian habitats. In this work, field spectroradiometry was used to assess the spectral separability of the giant reed from the adjacent vegetation and from the common reed, a native similar species. The study was conducted at different phenological periods and also for the giant reed stands regenerated after mechanical cutting (giant reed_RAC). A hierarchical procedure using Kruskal-Wallis test followed by Classification and Regression Trees (CART) was used to select the minimum number of optimal bands that discriminate the giant reed from the adjacent vegetation. A new approach was used to identify sets of wavelengths - wavezones - that maximize the spectral separability beyond the minimum number of optimal bands. Jeffries Matusita and Bhattacharya distance were used to evaluate the spectral separability using the minimum optimal bands and in three simulated satellite images, namely Landsat, IKONOS and SPOT. Giant reed was spectrally separable from the adjacent vegetation, both at the vegetative and the senescent period, exception made to the common reed at the vegetative period. The red edge region was repeatedly selected, although the visible region was also important to separate the giant reed from the herbaceous vegetation and the mid infrared region to the discrimination from the woody vegetation. The highest separability was obtained for the giant reed_RAC stands, due to its highly homogeneous, dense and dark-green stands. Results are discussed by relating the phenological, morphological and structural features of the giant reed stands and the adjacent vegetation with their optical traits. Weaknesses and strengths of the giant reed spectral discrimination are highlighted and implications of imagery selection for mapping purposes are argued based on present results.

  2. Treatment experiences among LGBT veterans with discrimination-based trauma exposure: A pilot study.

    Science.gov (United States)

    Shipherd, Jillian C; Ruben, Mollie A; Livingston, Nicholas A; Curreri, Andrew; Skolnik, Avy A

    2018-01-01

    Past research suggests that rates of trauma exposure and Posttraumatic Stress Disorder (PTSD) are elevated among lesbian, gay, bisexual, and transgender (LGBT) veterans compared to heterosexual and cisgender veterans. Given higher rates of trauma exposure and PTSD, and the culture associated with the Department of Defense's history of policies excluding LGBT people, it is important to understand if LGBT veterans are seeking PTSD treatment following discrimination-based traumatic events, where they seek care, and if they are satisfied with treatment. This study aimed to describe the experiences of discrimination-based trauma-exposed LGBT veterans' (n = 47) experiences with PTSD treatment, including location of treatment (Veterans Health Administration [VHA] versus non-VHA) and satisfaction with care. The majority of veterans had received a PTSD diagnosis from a health-care provider in their lifetimes (78.72%, n = 37), and over half reported currently experiencing PTSD symptoms. Approximately 47% of LGBT veterans with discrimination-based trauma histories preferred to seek PTSD treatment exclusively at VHA (46.81%) or with a combination of VHA and non-VHA services (38.30%). Veterans who received PTSD treatment exclusively from VHA reported higher satisfaction ratings (7.44 on 0-9 scale) than veterans who received PTSD treatment exclusively from outside VHA (5.25 on 0-9 scale). For veterans who sought PTSD treatment at both VHA and non-VHA facilities, there were no significant differences regarding satisfaction ratings for their PTSD treatment in the two settings. Results are discussed in terms of VHA's continued efforts to establish equitable, patient-centered health care for all veterans and the importance of non-VHA facilities to recognize veteran identities.

  3. Gender Wage Gap: Discrimination or Different Preferences of Men and Women? A Case Study of Ostrava, Czech Republic

    OpenAIRE

    Zuzana Machová; Lenka Filipová

    2013-01-01

    This paper was written as a part of a research project studying problem of wage determinant measuring and wage discrimination considering different wage requirements of men and women. The wage determinants and gender wage discrimination are analyzed using a probit model. The whole analysis is methodologically based on Mincer’s Wage Regression and Oaxaca-Blinder decomposition of gender wage gap. The wage variables include, aside from standard personal characteristics, dummies for institution...

  4. CSR as a Tool to Prevent Gender-Based Discrimination. A Case Study of the Textile Export Industry in India

    OpenAIRE

    Svedevall, Ida

    2015-01-01

    This thesis examines the ability of CSR as a tool in the efforts to reduce gender based discrimination in the textile industry in the Delhi area in India. This research focuses on the CSR work programs undertaken by foreign entities using the case study of the company Lindex. Given that discrimination occurs daily facilitated by embedded cultural structures this research questions how, and if, CSR interventions can be successful in address these underlying issues. This research draws on exist...

  5. Prevalence and Mental Health Correlates of Harassment and Discrimination in the Workplace: Results from a National Study

    OpenAIRE

    Rospenda, Kathleen M.; Richman, Judith A.; Shannon, Candice A.

    2008-01-01

    This study describes past-year prevalence and effects on mental health and drinking outcomes for harassment and discrimination in the workplace (HDW) in a nationally-representative random-digit dial phone survey conducted in 2003–2004 (n=2,151). HDW measures included experiences and perceptions of sexual harassment and generalized workplace harassment, and perceived harassment or discrimination due to race/ethnicity. Prevalence was examined by sex, race, age, occupation, marital status, and e...

  6. 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....

  7. 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

  8. The neural network involved in a bimanual tactile-tactile matching discrimination task: a functional imaging study at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Habas, Christophe; Cabanis, Emmanuel A. [UPMC Paris 6, Service de NeuroImagerie, Hopital des Quinze-Vingts, Paris (France)

    2007-08-15

    The cerebral and cerebellar network involved in a bimanual object recognition was studied in blood oxygenation dependent level functional magnetic resonance imaging (fMRI). Nine healthy right-handed volunteers were scanned (1) while performing bilateral finger movements (nondiscrimination motor task), and (2) while performing a bimanual tactile-tactile matching discrimination task using small chess pieces (tactile discrimination task). Extensive activations were specifically observed in the parietal (SII, superior lateral lobule), insular, prefrontal, cingulate and neocerebellar cortices (HVIII), with a left predominance in motor areas, during the tactile discrimination task in contrast to the findings during the nondiscrimination motor task. Bimanual tactile-tactile matching discrimination recruits multiple sensorimotor and associative cerebral and neocerebellar networks (including the cerebellar second homunculus, HVIII), comparable to the neural circuits involved in unimanual tactile object recognition. (orig.)

  9. 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.

  10. 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

  11. 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.

  12. Exploratory and discriminative studies of commercial processed Brazilian coffees with different degrees of roasting and decaffeinated

    Directory of Open Access Journals (Sweden)

    Juliano Souza Ribeiro

    2013-09-01

    Full Text Available The fingerprints of the volatile compounds of 21 commercial Brazilian coffee samples submitted to different industrial processing i.e. decaffeinated or different roasting degrees (traditional and dark were studied. The volatiles were collected by headspace solid phase microextraction (HS-SPME and analyzed by GC-FID and GC-MS. The chromatographic data matrices (fingerprints obtained were explored by the principal component analysis (PCA and partial least squares - discriminative analysis (PLS-DA. Initially the chromatographic profiles were aligned by the algorithm correlation optimized warping (COW. The PCA showed the discrimination of the decaffeinated coffees from the others with both the SPME fibres used. This separation probably occurred due to the loss of some volatile precursors during the decaffeination process, such as sucrose. For both the fibres tested, PDMS/DVB and CX / PDMS SPME, the PLS-DA models correctly classified 100% of the samples according to their roasting degree: (medium and dark, the main differences being the concentrations of some of the volatile compounds such as 2-methyl furan, 2-methylbutanal, 2,3-pentanedione, pyrazine, 2-carboxyaldehyde pyrrole, furfural and 2-furanmethanol.

  13. 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.)

  14. Beam shaping for conformal fractionated stereotactic radiotherapy: a modeling study

    International Nuclear Information System (INIS)

    Hacker, Fred L.; Kooy, Hanne M.; Bellerive, Marc R.; Killoran, Joseph H.; Leber, Zachary H.; Shrieve, Dennis C.; Tarbell, Nancy J.; Loeffler, Jay S.

    1997-01-01

    Purpose: The patient population treated with fractionated stereotactic radiotherapy (SRT) is significantly different than that treated with stereotactic radiosurgery (SRS). Generally, lesions treated with SRT are larger, less spherical, and located within critical regions of the central nervous system; hence, they offer new challenges to the treatment planner. Here a simple, cost effective, beam shaping system has been evaluated relative to both circular collimators and an ideal dynamically conforming system for effectiveness in providing conformal therapy for these lesions. Methods and Materials: We have modeled a simple system for conformal arc therapy using four independent jaws. The jaw positions and collimator angle are changed between arcs but held fixed for the duration of each arc. Eleven previously treated SRT cases have been replanned using this system. The rectangular jaw plans were then compared to the original treatment plans which used circular collimators. The plans were evaluated with respect to tissue sparing at 100%, 80%, 50%, and 20% of the prescription dose. A plan was also done for each tumor in which the beam aperture was continuously conformed to the beams eye view projection of the tumor. This was used as an ideal standard for conformal therapy in the absence of fluence modulation. Results: For tumors with a maximum extent of over 3.5 cm the rectangular jaw plans reduced the mean volume of healthy tissue involved at the prescription dose by 57% relative to the circular collimator plans. The ideal conformal plans offered no significant further improvement at the prescription dose. The relative advantage of the rectangular jaw plans decreased at lower isodoses so that at 20% of the prescription dose tissue involvement for the rectangular jaw plans was equivalent to that for the circular collimator plans. At these isodoses the ideal conformal plans gave substantially better tissue sparing. Conclusion: A simple and economical field shaping

  15. 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

  16. 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...

  17. Study of shape evaluation for mask and silicon using large field of view

    Science.gov (United States)

    Matsuoka, Ryoichi; Mito, Hiroaki; Shinoda, Shinichi; Toyoda, Yasutaka

    2010-09-01

    We have developed a highly integrated method of mask and silicon metrology. The aim of this integration is evaluating the performance of the silicon corresponding to Hotspot on a mask. It can use the mask shape of a large field, besides. The method adopts a metrology management system based on DBM (Design Based Metrology). This is the high accurate contouring created by an edge detection algorithm used in mask CD-SEM and silicon CD-SEM. Currently, as semiconductor manufacture moves towards even smaller feature size, this necessitates more aggressive optical proximity correction (OPC) to drive the super-resolution technology (RET). In other words, there is a trade-off between highly precise RET and mask manufacture, and this has a big impact on the semiconductor market that centers on the mask business. As an optimal solution to these issues, we provide a DFM solution that extracts 2-dimensional data for a more realistic and error-free simulation by reproducing accurately the contour of the actual mask, in addition to the simulation results from the mask data. On the other hand, there is roughness in the silicon form made from a mass-production line. Moreover, there is variation in the silicon form. For this reason, quantification of silicon form is important, in order to estimate the performance of a pattern. In order to quantify, the same form is equalized in two dimensions. And the method of evaluating based on the form is popular. In this study, we conducted experiments for averaging method of the pattern (Measurement Based Contouring) as two-dimensional mask and silicon evaluation technique. That is, observation of the identical position of a mask and a silicon was considered. The result proved its detection accuracy and reliability of variability on two-dimensional pattern (mask and silicon) and is adaptable to following fields of mask quality management. •Discrimination of nuisance defects for fine pattern. •Determination of two-dimensional variability of

  18. 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.

  19. 76 FR 35452 - Proposed Collection; Comment Request; Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2011-06-17

    ... scientific journals and will be used for the development of future research initiatives targeting childhood... Request; Healthy Communities Study: How Communities Shape Children's Health (HCS) SUMMARY: In compliance... Collection: Title: Healthy Communities Study: How Communities Shape Children's Health (HCS). Type of...

  20. 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

  1. STUDY THE CREEP OF TUBULAR SHAPED FIBER REINFORCED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Najat J. Saleh

    2013-05-01

    Full Text Available Inpresent work tubular –shaped fiber reinforced composites were manufactured byusing two types of resins ( Epoxy and unsaturated polyester and separatelyreinforced with glass, carbon and kevlar-49 fibers (filament and woven roving,hybrid reinforcement composites of these fibers were also prepared. The fiberswere wet wound on a mandrel using a purposely designed winding machine,developed by modifying an ordinary lathe, in winding angle of 55° for filament. A creep test was made of either the fulltube or specimens taken from it. Creep was found to increase upon reinforcementin accordance to the rule of mixture and mainly decided by the type of singleor hybridized fibers. The creep behavior, showed that the observed strain tendsto appear much faster at higher temperature as compared with that exhibited atroom temperate. The creep rate also found to be depending on fiber type, matrixtype, and the fiber /matrix bonding. The creep energy calculated fromexperimental observations was found to exhibit highest value for hybridizedreinforcement.

  2. 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.

  3. Accounting for Ethnic Discrimination : A Discursive Study Among Minority and Majority Group Members

    NARCIS (Netherlands)

    Verkuyten, Maykel J. A. M.

    2005-01-01

    This article discusses the ways in which ethnic minority and majority group members account, in an interview context, for the existence of discrimination in Dutch society. Taking a discursive approach, the focus is on the strategies used to describe and explain discrimination. In both groups,

  4. Discrimination, Affirmative Action and Women Academics: A Case Study of the University of New England.

    Science.gov (United States)

    Davies, Bronwyn

    1982-01-01

    Sex discrimination in employment is analyzed based on definitions developed through antidiscrimination legislation in Australia. Experiences at one university are used to illustrate how discrimination manifests and perpetuates itself in a cycle of attitudes, acts, and outcomes. Substantial data on employment patterns and practices are presented.…

  5. 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.

  6. 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.

  7. 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.

  8. A Comparative Study of Feature Selection Methods for the Discriminative Analysis of Temporal Lobe Epilepsy

    Directory of Open Access Journals (Sweden)

    Chunren Lai

    2017-12-01

    Full Text Available It is crucial to differentiate patients with temporal lobe epilepsy (TLE from the healthy population and determine abnormal brain regions in TLE. The cortical features and changes can reveal the unique anatomical patterns of brain regions from structural magnetic resonance (MR images. In this study, structural MR images from 41 patients with left TLE, 34 patients with right TLE, and 58 normal controls (NC were acquired, and four kinds of cortical measures, namely cortical thickness, cortical surface area, gray matter volume (GMV, and mean curvature, were explored for discriminative analysis. Three feature selection methods including the independent sample t-test filtering, the sparse-constrained dimensionality reduction model (SCDRM, and the support vector machine-recursive feature elimination (SVM-RFE were investigated to extract dominant features among the compared groups for classification using the support vector machine (SVM classifier. The results showed that the SVM-RFE achieved the highest performance (most classifications with more than 84% accuracy, followed by the SCDRM, and the t-test. Especially, the surface area and GMV exhibited prominent discriminative ability, and the performance of the SVM was improved significantly when the four cortical measures were combined. Additionally, the dominant regions with higher classification weights were mainly located in the temporal and the frontal lobe, including the entorhinal cortex, rostral middle frontal, parahippocampal cortex, superior frontal, insula, and cuneus. This study concluded that the cortical features provided effective information for the recognition of abnormal anatomical patterns and the proposed methods had the potential to improve the clinical diagnosis of TLE.

  9. 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

  10. 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.

  11. 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

  12. Are Joris and Renske more employable than Rashid and Samira? A study on the prevalence and sources of ethnic discrimination in recruitment in the Netherlands using experimental and survey data

    NARCIS (Netherlands)

    Blommaert, E.C.C.A.

    2013-01-01

    This study brings together four research lines from different scientific disciplines to expand existing knowledge on the pervasiveness of ethnic discrimination in recruitment and the circumstances under which discrimination is more likely to occur: (1) field experiments on discrimination in

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. Financial consumer protection and customer satisfaction. A relationship study by using factor analysis and discriminant analysis

    Directory of Open Access Journals (Sweden)

    Marimuthu SELVAKUMAR

    2015-11-01

    Full Text Available This paper tries to make an attempt to study the relationship between the financial consumer protection and customer satisfaction by using factor analysis and discriminant analysis. The main objectives of the study are to analyze the financial consumer protection in commercial banks, to examine the customer satisfaction of commercial banks and to identify the factors of financial consumer protection lead customer satisfaction. There are many research work carried out on financial consumer protection in financial literacy, but the identification of factors which lead the financial consumer protection and the relationship between financial consumer protection and the customer satisfaction is very important, Particularly for banks to improve its quality and increase the customer satisfaction. Therefore this study is carried out with the aim of identifying the factors of financial consumer protection and its influence on customer satisfaction. This study is both descriptive and analytical in nature. It covers both primary and secondary data. The primary data has been collected from the customers of commercial banks using pre-tested interview schedule and the secondary data has been collected from standard books, journals, magazines, websites and so on.

  18. What Shapes the Intention to Study Abroad? An Experimental Approach

    Science.gov (United States)

    Petzold, Knut; Moog, Petra

    2018-01-01

    In contrast to previous studies, this investigation aims to get deeper insights into the causes of the intention to study abroad by using an experimental approach. Although international experience is often considered as important, many students at German universities do not even consider abroad. Referring to the Theory of Rational Choice (RCT)…

  19. Shaping Up? Three Acts of Education Studies as Textual Critique

    Science.gov (United States)

    McDougall, Julian; Walker, Stephen; Kendall, Alex

    2006-01-01

    This paper presents a study of dominant educational discourses through textual critique and argues that such an approach enables education studies to preserve an important distinction from teacher training. The texts deconstructed here are specific to English education, but the discourses at work have international relevance as the rhetorics of…

  20. Perception, experience, and response to genetic discrimination in Huntington disease: the international RESPOND-HD study.

    Science.gov (United States)

    Erwin, Cheryl; Williams, Janet K; Juhl, Andrew R; Mengeling, Michelle; Mills, James A; Bombard, Yvonne; Hayden, Michael R; Quaid, Kimberly; Shoulson, Ira; Taylor, Sandra; Paulsen, Jane S

    2010-07-01

    Genetic discrimination-defined as the denial of rights, privileges, or opportunities or other adverse treatment based solely on genetic information (including family history)-is an important concern to patients, healthcare professionals, lawmakers, and family members at risk for carrying a deleterious gene. Data from the United States, Canada, and Australia were collected from 433 individuals at risk for Huntington disease (HD) who have tested either positive or negative for the gene that causes HD and family members of affected individuals who have a 50% risk for developing the disorder but remain untested. Across all three countries, a total of 46.2% of respondents report genetic discrimination or stigma based on either their family history of HD or genetic testing for the HD gene mutation. We report on the overall incidence of discrimination and stigma in the domains of insurance (25.9%), employment (6.5%), relationships (32.9%), and other transactions (4.6%) in the United States, Canada, and Australia combined. The incidence of self-reported discrimination is less than the overall worry about the risk of discrimination, which is more prevalent in each domain. Despite a relatively low rate of perceived genetic discrimination in the areas of health insurance and employment, compared to the perception of discrimination and stigma in personal relationships, the cumulative burden of genetic discrimination across all domains of experience represents a challenge to those at risk for HD. The effect of this cumulative burden on daily life decisions remains unknown. (c) 2010 Wiley-Liss, Inc.

  1. Muslim woman seeking work: An English case study with a dutch comparison, of discrimination and achievement

    OpenAIRE

    Bagley, C; Abubaker, M

    2017-01-01

    © 2016 by the author.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 emp...

  2. 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

  3. Study of α-energy discrimination in CR-39 track etch detectors for use as a radon/thoron dosemeter

    International Nuclear Information System (INIS)

    Kandaiya, S.; Al-Najjar, S.A.R.; Piesch, E.

    1988-01-01

    The properties of CR 39 nuclear track detectors were evaluated for their α-energy discrimination up to 8.77 MeV using a combination of chemical-electrochemical track revealing techniques. Using three field strengths, α-energy discrimination by ECE track diameter and track density as a function of chemical pre-etching time were studied. α-energy spectra using different irradiation geometries were then evaluated using the optimum conditions and then compared with those obtained form other techniques. (author)

  4. 78 FR 13350 - Proposed Collection; Comment Request Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2013-02-27

    ... community-based initiatives; community characteristics (e.g., school environment); measurements of children... used for the development of future research initiatives targeting childhood obesity. Frequency of... Request Healthy Communities Study: How Communities Shape Children's Health (HCS) Summary: Under the...

  5. Qualitative study of HIV related stigma and discrimination: What women say in Iran.

    Science.gov (United States)

    Oskouie, Fatemeh; Kashefi, Farzaneh; Rafii, Forough; Gouya, Mohammad Mehdi

    2017-07-01

    HIV-related stigma is a major social problem of people living with HIV. Stigma against these people, especially women, interferes with the prevention, diagnosis and treatment of HIV. This study examined the experiences of HIV infected women who were stigmatized, as well as the strategies used to tackle the issue. Twenty-five women living with HIV were examined using in-depth, semi-structured interviews. The data obtained was analyzed using content analysis method in MAXQDA10. The finding of this study was classified into four themes: fear, shame, rejection by family or friends and feelings of frustration. The participant strategies adopted to the perceived stigma and discrimination included isolation, nondisclosure, and loss of follow-up. HIV in women has different social interposition. It is necessary to intervene, so as to alleviate the effect of stigma on HIV infected women, in order that they gain the ability to accomplish wellness, increase life span and improve quality of life. Nurses, midwives and other professionals need to be involved to ensure public policy in providing supportive environments, and decrease stigma.

  6. Discrimination against Obese Exercise Clients: An Experimental Study of Personal Trainers.

    Science.gov (United States)

    Fontana, Fabio; Bopes, Jonathan; Bendixen, Seth; Speed, Tyler; George, Megan; Mack, Mick

    2018-01-01

    The aim of the study was to compare exercise recommendations, attitudes, and behaviors of personal trainers toward clients of different weight statuses. Fifty-two personal trainers participated in the study. The data collection was organized into two phases. In phase one, trainers read a profile and watched the video displaying an interview of either an obese or an average-weight client. Profiles and video interviews were identical except for weight status. Then, trainers provided exercise recommendations and rated their attitude toward the client. In phase two, trainers personally met an obese or an average-weight mock client. Measures were duration and number of advices provided by the trainer to a question posed by the client and sitting distance between trainer and client. There were no significant differences in exercise intensity ( p = .94), duration of first session ( p = .65), and total exercise duration of first week ( p = .76) prescribed to the obese and average-weight clients. The attitude of the personal trainers toward the obese client were not significantly different from the attitude of personal trainers toward the average-weight client ( p = .58). The number of advices provided ( p = .49), the duration of the answer ( p = .55), and the distance personal trainers sat from the obese client ( p = .68) were not significantly different from the behaviors displayed toward the average-weight client. Personal trainers did not discriminate against obese clients in professional settings.

  7. 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...

  8. Building the Nanoplasmonics Toolbox Through Shape Modeling and Single Particle Optical Studies

    Science.gov (United States)

    Ringe, Emilie

    Interest in nanotechnology is driven by unprecedented properties tailorability, achievable by controlling particle structure and composition. Unlike bulk components, minute changes in size and shape affect the optical and electronic properties of nanoparticles. Characterization of such structure-function relationships and better understanding of structure control mechanisms is crucial to the development of applications such as plasmonic sensors and devices. The objective of the current research is thus twofold: to theoretically predict and understand how shape is controlled by synthesis conditions, and to experimentally unravel, through single particle studies, how shape, composition, size, and surrounding environment affect plasmonic properties in noble metal particles. Quantitative, predictive rules and fundamental knowledge obtained from this research contributes to the "nanoplasmonics toolbox", a library designed to provide scientists and engineers the tools to create and optimize novel nanotechnology applications. In this dissertation, single particle approaches are developed and used to unravel the effects of size, shape, substrate, aggregation state and surrounding environment on the optical response of metallic nanoparticles. Ag and Au nanocubes on different substrates are first presented, followed by the discussion of the concept of plasmon length, a universal parameter to describe plasmon energy for a variety of particle shapes and plasmon modes. Plasmonic sensing (both refractive index sensing and surface-enhanced Raman spectroscopy) and polarization effects are then studied at the single particle level. In the last two Chapters, analytical shape models based on the Wulff construction provide unique modeling tools for alloy and kinetically grown nanoparticles. The former reveals a size-dependence of the shape of small alloy particles (such as those used in catalysis) because of surface segregation, while the latter uniquely models the shape of many

  9. Perceived ethnic discrimination in relation to smoking and alcohol consumption in ethnic minority groups in The Netherlands: the HELIUS study

    NARCIS (Netherlands)

    Visser, Marlies J.; Ikram, Umar Z.; Derks, Eske M.; Snijder, Marieke B.; Kunst, Anton E.

    2017-01-01

    We examined the associations of perceived ethnic discrimination (PED) with smoking and alcohol consumption in ethnic minority groups residing in a middle-sized European city. Data were derived from the HELIUS study in Amsterdam, The Netherlands. We included 23,126 participants aged 18-70 years of

  10. The Utility of the MMPI-2 Malingering Discriminant Function Index in the Detection of Malingering: A Study of Criminal Defendants

    Science.gov (United States)

    Toomey, Joseph A.; Kucharski, L. Thomas; Duncan, Scott

    2009-01-01

    This study examined the utility of the Minnesota Multiphasic Personality Inventory-2's (MMPI-2) malingering discriminant function index (M-DFI), recently developed by Bacchiochi and Bagby, in the detection of malingering in a forensic sample. Criminal defendants were divided into "malingering" and "not malingering" groups using…

  11. Prevalence and Mental Health Correlates of Harassment and Discrimination in the Workplace: Results from a National Study

    Science.gov (United States)

    Rospenda, Kathleen M.; Richman, Judith A.; Shannon, Candice A.

    2009-01-01

    This study describes past-year prevalence and effects on mental health and drinking outcomes for harassment and discrimination in the workplace (HDW) in a nationally representative random digit dial phone survey conducted in 2003-2004 (n = 2,151). HDW measures included experiences and perceptions of sexual harassment (SH) and generalized workplace…

  12. 'Flying below the radar': a qualitative study of minority experience and management of discrimination in academic medicine.

    Science.gov (United States)

    Carr, Phyllis L; Palepu, Anita; Szalacha, Laura; Caswell, Cheryl; Inui, Thomas

    2007-06-01

    This paper aims to give voice to the lived experience of faculty members who have encountered racial or ethnic discrimination in the course of their academic careers. It looks at how they describe the environment for minorities, how they manage discrimination and what institutions and majority-member faculty can do to improve medical academe for minority members. Qualitative techniques were used for semi-structured, in-depth individual telephone interviews, which were audiotaped, transcribed and analysed by reviewers. Themes expressed by multiple faculty members were studied for patterns of connection and grouped into broader categories. A description of the faculty sample is provided, in which respondents ranked the importance of discrimination in hindering academic advancement and used Likert scales to evaluate effects of discrimination. The sample was drawn from 12 of 24 academic medical centres in the National Faculty Survey and included 18 minority-member faculty staff stratified by gender, rank and degree who had experienced, or possibly experienced, work-related discrimination. Minority faculty described the need to be strongly self-reliant, repeatedly prove themselves, develop strong supports and acquire a wide range of academic skills to succeed. Suggested responses to discrimination were to be cautious, level-headed and informed. Confronting discriminatory actions by sitting down with colleagues and raising the level of awareness were important methods of dealing with such situations. Academic medical centres may need to make greater efforts to support minority faculty and improve understanding of the challenges confronting such faculty in order to prevent the loss and/or under-utilisation of important talent.

  13. A reactor study on a belt-shaped screw pinch

    International Nuclear Information System (INIS)

    Bustraan, M.; Franken, W.M.P.; Klippel, H.Th.; Veringa, H.J.; Verschuur, K.A.

    1979-10-01

    A previous study on a screw-pinch reactor with circular cross section (ECN-16 (1977) or Rijnhuizen report 77-101) has been extended to a belt configuration which allows to raise β to 0.5. The present study starts from the main assumptions and principal constraints of the previous work, but some technical aspects are treated more realistically. More attention has been paid to the modular construction, the non-uniform distribution of the wall loading, the thermo-hydraulics, the design of and the losses in the coil systems, and the energy storage and electric transmission systems. A potential use of the first wall of the blanket as part of the implosion coil system is suggested. Finally, a conceptual design of a reactor, with a cost estimate is given. Numerical results are given of parameter variations around the values for the reference reactor. The belt screw-pinch reactor with resistive coils turns out to be uneconomical because of its low net efficiency and its high capital costs. The application of superconducting coils to reduce the ohmic losses turns out to be a non-viable alternative. A more promising way to improve the energy balance seems to be the alternative scheme of fuel injection during the burn

  14. 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

  15. Study of a scintillation detector of special shape

    International Nuclear Information System (INIS)

    Empl, A.

    1989-07-01

    Object of this thesis is the study of a rotated scintillator segment especially regarding its light yield. For this both an experiment with the prototype of a segment was performed and also software was produced which simulates the photon transport through light guides and scintillators. The latter allows to obtain without experiment first estimations of the optical properties for variations of the 'verticil' segment. In the central chapter 3 the experimental arrangement and the performance of the experiment are described. Subsequently the measurement results are presented. Previously however chapter 2 is dedicated to the simulation of the photon transport (program structure, simulation results) and the special geometry of the 'verticil'. (orig./HSI) [de

  16. Experimental study and theoretical simulation of the cross hardening effect in shape memory alloys

    Science.gov (United States)

    Movchan, A. A.; Sil'chenko, A. L.; Kazarina, S. A.

    2017-10-01

    The shapes and the relative position of martensitic inelasticity and forward transformation diagrams are experimentally studied. The strain dependences of the stress in loading under martensitic inelasticity conditions after an experiment on the accumulation of the forward transformation-induced strain at a constant or variable stress are investigated on titanium nickelide samples. It is found that the hardening of the martensite part of the representative volume of a shape memory alloy (titanium nickelide) after forward transformation under a nonmonotonically changing stress can be nonuniform. The cross hardening phenomenon is theoretically described in terms of the model of nonlinear deformation of a shape memory alloy during phase and structural transformations.

  17. Discrimination of stress in speech and music: a mismatch negativity (MMN) study.

    Science.gov (United States)

    Peter, Varghese; McArthur, Genevieve; Thompson, William Forde

    2012-12-01

    The aim of this study was to determine if duration-related stress in speech and music is processed in a similar way in the brain. To this end, we tested 20 adults for their abstract mismatch negativity (MMN) event-related potentials to two duration-related stress patterns: stress on the first syllable or note (long-short), and stress on the second syllable or note (short-long). A significant MMN was elicited for both speech and music except for the short-long speech stimulus. The long-short stimuli elicited larger MMN amplitudes for speech and music compared to short-long stimuli. An extra negativity-the late discriminative negativity (LDN)-was observed only for music. The larger MMN amplitude for long-short stimuli might be due to the familiarity of the stress pattern in speech and music. The presence of LDN for music may reflect greater long-term memory transfer for music stimuli. Copyright © 2012 Society for Psychophysiological Research.

  18. Sex determination using discriminant function analysis in Indigenous (Kurubas children and adolescents of Coorg, Karnataka, India: A lateral cephalometric study

    Directory of Open Access Journals (Sweden)

    Darshan Devang Divakar

    2016-11-01

    Full Text Available Aim: To test the validity of sex discrimination using lateral cephalometric radiograph and discriminant function analysis in Indigenous (Kuruba children and adolescents of Coorg, Karnataka, India. Methods and materials: Six hundred and sixteen lateral cephalograms of 380 male and 236 females of age ranging from 6.5 to 18 years of Indigenous population of Coorg, Karnataka, India called Kurubas having a normal occlusion were included in the study. Lateral cephalograms were obtained in a standard position with teeth in centric occlusion and lips relaxed. Each radiograph was traced and cephalometric landmarks were measured using digital calliper. Calculations of 24 cephalometric measurements were performed. Results: Males exhibited significantly greater mean angular and linear cephalometric measurements as compared to females (p < 0.05 (Table 5. Also, significant differences (p < 0.05 were observed in all the variables according to age (Table 6. Out of 24 variables, only ULTc predicts the gender. The reliability of the derived discriminant function was assessed among study subjects; 100% of males and females were recognized correctly. Conclusion: The final outcome of this study validates the existence of sexual dimorphism in the skeleton as early as 6.5 years of age. There is a need for further research to determine other landmarks that can help in sex determination and norms for Indigenous (Kuruba population and also other Indigenous population of Coorg, Karnataka, India. Keywords: Discriminant function analysis, Forensic investigation, Indigenous, Lateral cephalograms, Sex determination

  19. 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.

  20. A Comparative Study of Shaping Ability of four Rotary Systems.

    Science.gov (United States)

    Rubio, Jorge; Zarzosa, José Ignacio; Pallarés, Antonio

    2015-12-01

    This study compared the cutting area, instrumentation time, root canal anatomy preservation and non-instrumented areas obtained by F360(®), Mtwo(®), RaCe(®) and Hyflex(®) files with ISO size 35. 120 teeth with a single straight root and root canal were divided into 4 groups. Working length was calculated by using X-rays. The teeth were sectioned with a handpiece and a diamond disc, and the sections were observed with Nikon SMZ-2T stereoscopic microscope and an Intralux 4000-1 light source. The groups were adjusted with a preoperative analysis with AutoCAD. The teeth were reconstructed by a #10 K-File and epoxy glue. Each group was instrumented with one of the four file systems. The instrumentation time was calculated with a 1/100 second chronometer. The area of the thirds and root canal anatomy preservation were analyzed with AutoCAD 2013 and the non-instrumented areas with AutoCAD 2013 and SMZ-2T stereoscopic microscope. The statistical analysis was made with Levene's Test, ANOVA, Bonferroni Test and Pearson´s Chi-square. Equal variances were shown by Levene's Test (P > 0.05). ANOVA (P > 0.05) showed the absence of significant differences. There were significant differences in the instrumentation time (P 0.05). The 4 different rotary systems produced similar cutting area, root canal anatomy preservation and non-instrumented areas. Regarding instrumentation time, F360(®) was the fastest system statistically.

  1. A Comparative Study of Shaping Ability of four Rotary Systems

    Directory of Open Access Journals (Sweden)

    Jorge Rubio

    2015-01-01

    Full Text Available Purpose: This study compared the cutting area, instrumentation time, root canal anatomy preservation and non-instrumented areas obtained by F360®, Mtwo®, RaCe® and Hyflex® files with ISO size 35. Material and Methods: 120 teeth with a single straight root and root canal were divided into 4 groups. Working length was calculated by using X-rays. The teeth were sectioned with a handpiece and a diamond disc, and the sections were observed with Nikon SMZ-2T stereoscopic microscope and an Intralux 4000-1 light source. The groups were adjusted with a preoperative analysis with AutoCAD. The teeth were reconstructed by a #10 K-File and epoxy glue. Each group was instrumented with one of the four file systems. The instrumentation time was calculated with a 1/100 second chronometer. The area of the thirds and root canal anatomy preservation were analyzed with AutoCAD 2013 and the non-instrumented areas with AutoCAD 2013 and SMZ-2T stereoscopic microscope. The statistical analysis was made with Levene’s Test, ANOVA, Bonferroni Test and Pearson´s Chi-square. Results: Equal variances were shown by Levene’s Test (P > 0.05. ANOVA (P > 0.05 showed the absence of significant differences. There were significant ifferences in the instrumentation time (P 0.05. Conclusions: The 4 different rotary systems produced similar cutting area, root canal anatomy preservation and non-instrumented areas. Regarding instrumentation time, F360® was the fastest system statistically.

  2. Simians in the Shape School: A comparative study of executive attention.

    Science.gov (United States)

    French, Kristin; Beran, Michael J; Espy, Kimberly Andrews; Washburn, David A

    2018-01-08

    Executive functions (EF) have been studied extensively in children and adults. However, EF tasks for young children can be difficult to administer and interpret. Espy (1997, Developmental Neuropsychology, 13, 495-499) designed the Shape School task to measure inhibition and switching in preschool-aged children. Shape School presents cartoon-like characters that children must flexibly name by their color, their shape, or both, depending on cues that indicate the appropriate rule. Shape School has been found to be age sensitive as well as predictive of performance on other EF tasks. We presented a computerized analogue of Shape School to seven rhesus macaques. Monkeys were trained to categorize characters by color or shape, or to inhibit this response, depending on whether the characters had eyes open, eyes closed, or wore hats. Monkeys performed above chance on the inhibition and switching components of the task. Long runs of a single classification rule and long runs of noninhibition trials had no significant impact on performance when the rule changed or inhibition was required. This nonverbal adaptation of Shape School can measure EF in nonhuman animals and could be used in conjunction with other EF tasks to provide a clearer picture of both human and nonhuman executive functions.

  3. Mass discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Broeckman, A. [Rijksuniversiteit Utrecht (Netherlands)

    1978-12-15

    In thermal ionization mass spectrometry the phenomenon of mass discrimination has led to the use of a correction factor for isotope ratio-measurements. The correction factor is defined as the measured ratio divided by the true or accepted value of this ratio. In fact this factor corrects for systematic errors of the whole procedure; however mass discrimination is often associated just with the mass spectrometer.

  4. 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.

  5. 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.

  6. 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

  7. Experimental and modelling studies of the shape memory properties of amorphous polymer network composites

    International Nuclear Information System (INIS)

    Arrieta, J S; Diani, J; Gilormini, P

    2014-01-01

    Shape memory polymer composites (SMPCs) have become an important way to leverage improvements in the development of applications featuring shape memory polymers (SMPs). In this study, an amorphous SMP matrix has been filled with different types of reinforcements. An experimental set of results is presented and then compared to three-dimensional (3D) finite-element simulations. Thermomechanical shape memory cycles were performed in uniaxial tension. The fillers effect was studied in stress-free and constrained-strain recoveries. Experimental observations indicate complete shape recovery and put in evidence the increased sensitivity of constrained length stress recoveries to the heating ramp on the tested composites. The simulations reproduced a simplified periodic reinforced composite and used a model for the matrix material that has been previously tested on regular SMPs. The latter combines viscoelasticity at finite strain and time-temperature superposition. The simulations easily allow representation of the recovery properties of a reinforced SMP. (paper)

  8. 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.

  9. Predicting The Type Of Pregnancy Using Flexible Discriminate Analysis And Artificial Neural Networks: A Comparison Study

    International Nuclear Information System (INIS)

    Hooman, A.; Mohammadzadeh, M.

    2008-01-01

    Some medical and epidemiological surveys have been designed to predict a nominal response variable with several levels. With regard to the type of pregnancy there are four possible states: wanted, unwanted by wife, unwanted by husband and unwanted by couple. In this paper, we have predicted the type of pregnancy, as well as the factors influencing it using three different models and comparing them. Regarding the type of pregnancy with several levels, we developed a multinomial logistic regression, a neural network and a flexible discrimination based on the data and compared their results using tow statistical indices: Surface under curve (ROC) and kappa coefficient. Based on these tow indices, flexible discrimination proved to be a better fit for prediction on data in comparison to other methods. When the relations among variables are complex, one can use flexible discrimination instead of multinomial logistic regression and neural network to predict the nominal response variables with several levels in order to gain more accurate predictions

  10. 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.

  11. Cheiloscopy, Palatoscopy and Odontometrics in Sex Prediction and Dis-crimination - a Comparative Study.

    Science.gov (United States)

    V, Nagalaxmi; Ugrappa, Sridevi; M, Naga Jyothi; Ch, Lalitha; Maloth, Kotya Naik; Kodangal, Srikanth

    2014-01-01

    Human identification is the forensic odontologist's primary duty in the fields like violent crime, child abuse, elder abuse, missing persons and mass disaster scenarios. In each context, dental traits may produce compelling evidence to aid victim identity, suspect identity and narrow down the outcome of investigative casework. Sometimes it becomes necessary to apply some least known and less popular techniques in identification procedure where lip prints, rugae patterns and canine odontometrics can give us comparatively valid conclusions pertaining to person's identification. This study elucidates the significance of cheiloscopy, palatoscopy and canine odontometry in sex prediction and discrimination. A cross- sectional study involving a total of 60 subjects, 30 males and 30 females were selected from the outpatient department of oral medicine and radiology. Lip prints were recorded using lipstick, palatal impressions were taken with alginate and odontometric measurements were taken with digital vernier calipers from every subject. All the obtained records were analyzed by two observers. Reliability of lip prints was assessed using Kappa coefficient. Comparison of rugae patterns was done using Chi-square test. Mean canine and inter canine width was compared using t test. A p-value of print patterns analyzed in males and females, while no significant difference was observed in the rugae patterns but a significant difference in the mesio-distal width of mandibular canines in males and females was found with right mandibular canine(3.73%) showing greater sexual dimorphism compared to left mandibular canine(3.06%). This study shows the uniqueness of the lip prints and rugae patterns with the lip prints showing sensitivity of 81.7% giving reliable prediction of sex over palatoscopy. Hence, cheiloscopy along with the canine odontometrics aid in sex determination and can be considered as an ancilliary forensic tool in identification.

  12. Recent Advances in the Study of Bipolar/Rod-Shaped Microglia and their Roles in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Ngan Pan Bennett Au

    2017-05-01

    Full Text Available Microglia are the resident immune cells of the central nervous system (CNS and they contribute to primary inflammatory responses following CNS injuries. The morphology of microglia is closely associated with their functional activities. Most previous research efforts have attempted to delineate the role of ramified and amoeboid microglia in the pathogenesis of neurodegenerative diseases. In addition to ramified and amoeboid microglia, bipolar/rod-shaped microglia were first described by Franz Nissl in 1899 and their presence in the brain was closely associated with the pathology of infectious diseases and sleeping disorders. However, studies relating to bipolar/rod-shaped microglia are very limited, largely due to the lack of appropriate in vitro and in vivo experimental models. Recent studies have reported the formation of bipolar/rod-shaped microglia trains in in vivo models of CNS injury, including diffuse brain injury, focal transient ischemia, optic nerve transection and laser-induced ocular hypertension (OHT. These bipolar/rod-shaped microglia formed end-to-end alignments in close proximity to the adjacent injured axons, but they showed no interactions with blood vessels or other types of glial cell. Recent studies have also reported on a highly reproducible in vitro culture model system to enrich bipolar/rod-shaped microglia that acts as a powerful tool with which to characterize this form of microglia. The molecular aspects of bipolar/rod-shaped microglia are of great interest in the field of CNS repair. This review article focuses on studies relating to the morphology and transformation of microglia into the bipolar/rod-shaped form, along with the differential gene expression and spatial distribution of bipolar/rod-shaped microglia in normal and pathological CNSs. The spatial arrangement of bipolar/rod-shaped microglia is crucial in the reorganization and remodeling of neuronal and synaptic circuitry following CNS injuries. Finally, we

  13. Penerapan Prinsip Non Discrimination Dalam World Trade Organization Terhadap Kebijakan Tenaga Kerja Asing Di Indonesia (Studi Kasus : Tenaga Kerja Asing Tiongkok Di Indonesia)

    OpenAIRE

    -, VERA NURUL HAYATI

    2016-01-01

    2016 Vera Nurul Hayati (B 111 12 117),The Application of Non Discrimination Principle of World Trade Organization Against Foreign Workers in Indonesia (Case Study : China Foreign Workers in Indonesia), led by Muhammad Ashri dan Laode Abdul Gani. Writing aims to determine 1) Implementation of Non Discrimination principle on policy regulation against Foreign labor in Indonesia. 2) Enforcement of non discrimination principle against Tiongkok foreign labor in Indonesia. ...

  14. 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 ...

  15. 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.

  16. 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.

  17. 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.

  18. Teaching Consumer Price Discrimination: An Interdisciplinary Case Study for Business Law Students

    Science.gov (United States)

    Edwards, Matthew A.

    2014-01-01

    It is generally agreed that price discrimination can, in some circumstances at least, be an extraordinarily unpopular business practice. In late 2000, customers discovered that Amazon.com was varying its prices online for the exact same products. Although the incident is almost fifteen years old, it has become the standard reference in law review…

  19. Gender Discrimination in Educational Personnel: A Case Study of Gweru Urban District Secondary Schools, Zimbabwe

    Science.gov (United States)

    Matope, Nogget

    2012-01-01

    Gender discrimination in educational institutions persists, despite the vigorous pursuit of policies and programmes to reduce the varying degrees of gender inequity in Zimbabwe. Zimbabwe is a signatory to international agreements and conventions which promote gender equity with a thrust towards increased access to education for girls and females.…

  20. Gender Discrimination and Sexual Harassment in Medical Education: Perspectives Gained by a 14-School Study.

    Science.gov (United States)

    Nora, Lois Margaret; McLaughlin, Margaret A.; Fosson, Sue E.; Stratton, Terry D.; Murphy-Spencer, Amy; Fincher, Ruth-Marie E.; German, Deborah C.; Seiden, David; Witzke, Donald B.

    2002-01-01

    Surveyed medical students about their exposures to and perceptions of gender discrimination and sexual harassment (GD/SH) in selected academic and nonacademic contexts. Findings included that more women than men reported all types of GD/SH across all contexts, and that GD/SH is prevalent in undergraduate medical education, particularly within core…

  1. Gender Discrimination as a Function of Stereotypic and Counterstereotypic Behavior: A Cross-Cultural Study.

    Science.gov (United States)

    Lobel, Thalma E.; Mashraki-Pedhatzur, Sharon; Mantzur, Ahmed; Libby, Sharon

    2000-01-01

    Investigated seventh graders' gender discrimination from a cross-cultural perspective. Israeli Arabs and Jews rated two hypothetical male candidates for class representative (who were generally masculine or outstandingly feminine) on their beliefs about their ability to be elected and their willingness to interact with them. Both groups…

  2. Discriminant Validity of Self-Reported Emotional Intelligence: A Multitrait-Multisource Study

    Science.gov (United States)

    Joseph, Dana L.; Newman, Daniel A.

    2010-01-01

    A major stumbling block for emotional intelligence (EI) research has been the lack of adequate evidence for discriminant validity. In a sample of 280 dyads, self- and peer-reports of EI and Big Five personality traits were used to confirm an a priori four-factor model for the Wong and Law Emotional Intelligence Scale (WLEIS) and a five-factor…

  3. Gender discrimination and sexual harassment in medical education: perspectives gained by a 14-school study.

    Science.gov (United States)

    Nora, Lois Margaret; McLaughlin, Margaret A; Fosson, Sue E; Stratton, Terry D; Murphy-Spencer, Amy; Fincher, Ruth-Marie E; German, Deborah C; Seiden, David; Witzke, Donald B

    2002-12-01

    The authors attempted to determine male and female medical students' exposures to and perceptions of gender discrimination and sexual harassment (GD/SH) in selected academic and nonacademic contexts. An anonymous, self-report questionnaire was administered in the spring of 1997 to senior medical students at 14 U.S. medical schools. Data were collected about students' exposures to GD/SH during undergraduate medical education and outside the medical training environment. Students' perceptions of GD/SH in various medical specialties and practice settings were also measured. Of the 1,911 questionnaires administered, 1,314 were completed (response rate, 69%). Both men and women reported exposures to GD/SH. More women than men reported all types of exposures to GD/SH across all academic and nonacademic contexts. Differences between men and women in the frequencies of exposures were greatest outside the medical training environment (t = 15.67, df = 1171, p study suggests that mistreatment in the form of GD/SH is prevalent in undergraduate medical education, particularly within core clerkships. Interventions focused on particular specialties and training periods may be helpful.

  4. 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.

  5. Discrimination and Assessment of Induced Seismicity in Active Tectonic Zones: A Case Study from Southern California

    Science.gov (United States)

    Bachmann, C. E.; Lindsey, N.; Foxall, W.; Robertson, M.

    2014-12-01

    Earthquakes induced by human activity have become a matter of heightened public concern during recent years. Of particular concern is seismicity associated with wastewater injection, which has included events having magnitudes greater than 5. The causes of the induced events are primarily changes in pore-pressure, fluid volume and perhaps temperature due to injection. Recent research in the US has focused on mid-continental regions having low rates of naturally-occurring seismicity, where induced events can be identified by relatively straightforward spatial and temporal correlation of seismicity with high-volume injection activities. Recent examples include events correlated with injection of wastewater in Oklahoma, Arkansas, Texas and Ohio, and long-term brine injection in the Paradox Valley in Colorado. Even in some of the cases where there appears at first sight to be a clear spatial correlation between seismicity and injection, it has been difficult to establish causality definitively. Here, we discuss methods to identify induced seismicity in active tectonic regions. We concentrate our study on Southern California, where large numbers of wastewater injection wells are located in oil-producing basins that experience moderate to high rates of naturally-occurring seismicity. Using the catalog of high-precision CISN relocations produced by Hauksson et al. (BSSA, 2012), we aim to discriminate induced from natural events based on spatio-temporal patterns of seismicity occurrence characteristics and their relationships to injection activities, known active faults and other faults favorably oriented for slip under the tectonic stress field. Since the vast majority of induced earthquakes are very small, it is crucial to include all events above the detection threshold of the CISN in each area studied. In addition to exploring the correlation of seismicity to injection activities in time and space, we analyze variations in frequency-magnitude distributions, which can

  6. Study of the morphology exhibited by linear segmented polyurethanes during shape memory cycles

    International Nuclear Information System (INIS)

    Pereira, I.M.; Orefice, R.L.

    2009-01-01

    By using small-angle X-ray, this study aims to identify the role of the morphological structures of linear segmented thermoplastic polyurethane during shape memory cycle. A deformed specimen was placed on a heating stage mounted at the beamline; the shape recovery was measured during 20min. Furthermore, to study the influence of the temperature during recover, the specimens were subjected to different thermo-cycle. In each condition, the phase morphology and composition were investigated. Recovery process was separated into three stages. Bulk incompatibility and entropic recovery were the two controlling features for determining the final polyurethane morphology. (author)

  7. Study of shape phase transition at N = 60 in Zr and Pd

    International Nuclear Information System (INIS)

    Kumar, Rajesh; Gupta, J.B.; Sharma, S.

    2011-01-01

    The level structure of Zr, Mo, Ru and Pd in the region of A = 100 has been of much interest recently. At N=60 the level structure varies rather sharply. Below N = 60 the structure is vibrator like and at N > 60, the structure corresponds to a rotor. The use of single term expression for level energies in the study of shape phase transition at N=60 is illustrated here. The much sharper shape transition of Zr and slower for Pd is exhibited. There being only two free parameters one can study the nuclei with fewer levels as well

  8. A radiographic study of the position and shape of mental foramen in panoramic radiographs

    International Nuclear Information System (INIS)

    Choi, Karp Shik; Kim, Dong Youn; Sohn, Jeong Ick; Bae, Yong Chul

    1997-01-01

    The purpose of this study was to evaluate the position and shape of mental foramen in panoramic radiographs. For this study, panoramic radiographs were obtained from the 200 adults and evaluated the position and shape of mental foramen. According to various positional changes in panoramic radiographs of the patients, the author also obtained panoramic radiographs from the 100 adults and then evaluated the positional and shape changes of mental foramen. The following results were obtained : 1. Shapes of mental foramen were observed elliptical (43.3%), round or oval (42.5%), unidentified (7.5%) and diffuse (6.7%) type in descending order of frequency. 2. Horizontal position of mental foramen were most frequently observed at the 2nd premolar area (54.2%), and area between the 1st premolar and 2nd premolar (43.1%), area between the 2nd premolar and 1st molar (2.7%), and at apex (9.7%), overlap with apex (1.9%), superior of apex (0.2%) in descending order of frequency. 4. According to various positional changes in panoramic radiographs of the patients, shape changes of mental foramen were more obviously observed at the forward 10 mm and chin down 10 degree positioned panoramic radiographs, And changes of horizontal and vertical position were observed in similar to compared with normal positioned panoramic radiographs.

  9. Objective Tests and Their Discriminating Power in Business Courses: a Case Study

    Directory of Open Access Journals (Sweden)

    Edgard B. Cornachione Jr.

    2005-07-01

    Full Text Available Evaluating students’ learning experiences outcomes cannot be considered a simple task. This paper aims at investigating students’ overall performance and the discriminating power of particular tests’ items in the context of business courses. The purpose of this paper is to contribute with this issue while analyzing it, with scientific approach, from an accounting information systems standpoint: two experiments based on a database management system (DBMS undergraduate course, involving 66 and 62 students (experiments E1 and E2, respectively. The discriminant analysis generated discriminant functions with high canonical correlations (E1=0.898 and E2= 0.789. As a result, high percentages of original grouped cases were correctly classified (E1=98.5% and E2= 95.2% based on a relatively small number of items: 7 out of 22 items from E1 (multiple-choice, and 3 out of 6 from E2 (short-answer. So, with only a few items from the analyzed instruments it is possible todiscriminate “good” or “bad” academic performance, and this is a measure of quality of the observed testing instruments. According to these findings, especially in business area, instructors and institutions, together, are able to analyze and act towards improving their assessment methods, to be of minimum influence whileevaluating students’ performance.

  10. Computational and experimental study of effects of sediment shape on erosion of hydraulic turbines

    International Nuclear Information System (INIS)

    Poudel, L; Thapa, B; Shrestha, B P; Thapa, B S; Shrestha, K P; Shrestha, N K

    2012-01-01

    Hard particles as Quartz and Feldspar are present in large amount in most of the rivers across the Himalayan basins. In run-off-river hydro power plants these particles find way to turbine and cause its components to erode. Loss of turbine material due to the erosion and subsequent change in flow pattern induce several operational and maintenance problems in the power plants. Reduction in overall efficiency, vibrations and reduced life of turbine components are the major effects of sediment erosion of hydraulic turbines. Sediment erosion of hydraulic turbines is a complex phenomenon and depends upon several factors. One of the most influencing parameter is the characteristics of sediment particles. Quantity of sediment particles, which are harder than the turbine material, is one of the bases to indicate erosion potential of a particular site. Research findings have indicated that shape and size of the hard particles together with velocity of impact play a major role to decide the mode and rate of erosion in turbine components. It is not a common practice in Himalayan basins to conduct a detail study of sediment characteristics as a part of feasibility study for hydropower projects. Lack of scientifically verified procedures and guidelines to conduct the sediment analysis to estimate its erosion potential is one of the reasons to overlook this important part of feasibility study. Present study has been conducted by implementing computational tools to characterize the sediment particles with respect to their shape and size. Experimental studies have also been done to analyze the effects of different combinations of shape and size of hard particles on turbine material. Efforts have also been given to develop standard procedures to conduct similar study to compare erosion potential between different hydropower sites. Digital image processing software and sieve analyzer have been utilized to extract shape and size of sediment particles from the erosion sensitive power

  11. Sex determination using discriminant function analysis in Indigenous (Kurubas) children and adolescents of Coorg, Karnataka, India: A lateral cephalometric study.

    Science.gov (United States)

    Devang Divakar, Darshan; John, Jacob; Al Kheraif, Abdulaziz Abdullah; Mavinapalla, Seema; Ramakrishnaiah, Ravikumar; Vellappally, Sajith; Hashem, Mohamed Ibrahim; Dalati, M H N; Durgesh, B H; Safadi, Rima A; Anil, Sukumaran

    2016-11-01

    Aim: To test the validity of sex discrimination using lateral cephalometric radiograph and discriminant function analysis in Indigenous (Kuruba) children and adolescents of Coorg, Karnataka, India. Methods and materials: Six hundred and sixteen lateral cephalograms of 380 male and 236 females of age ranging from 6.5 to 18 years of Indigenous population of Coorg, Karnataka, India called Kurubas having a normal occlusion were included in the study. Lateral cephalograms were obtained in a standard position with teeth in centric occlusion and lips relaxed. Each radiograph was traced and cephalometric landmarks were measured using digital calliper. Calculations of 24 cephalometric measurements were performed. Results: Males exhibited significantly greater mean angular and linear cephalometric measurements as compared to females ( p  gender. The reliability of the derived discriminant function was assessed among study subjects; 100% of males and females were recognized correctly. Conclusion: The final outcome of this study validates the existence of sexual dimorphism in the skeleton as early as 6.5 years of age. There is a need for further research to determine other landmarks that can help in sex determination and norms for Indigenous (Kuruba) population and also other Indigenous population of Coorg, Karnataka, India.

  12. Dexamethasone facilitates fear extinction and safety discrimination in PTSD: A placebo-controlled, double-blind study.

    Science.gov (United States)

    Michopoulos, Vasiliki; Norrholm, Seth D; Stevens, Jennifer S; Glover, Ebony M; Rothbaum, Barbara O; Gillespie, Charles F; Schwartz, Ann C; Ressler, Kerry J; Jovanovic, Tanja

    2017-09-01

    Psychophysiological hallmarks of posttraumatic stress disorder (PTSD) include exaggerated fear responses, impaired inhibition and extinction of conditioned fear, and decreased discrimination between safety and fear cues. This increased fear load associated with PTSD can be a barrier to effective therapy thus indicating the need for new treatments to reduce fear expression in people with PTSD. One potential biological target for reducing fear expression in PTSD is the hypothalamic-pituitary-adrenal (HPA) axis, which is dysregulated in PTSD. Recent translational rodent studies and cross-sectional clinical studies have shown that dexamethasone administration and the resulting suppression of cortisol in individuals with PTSD leads to a decrease in the fear responses characteristic of PTSD. These data, taken together, suggest that dexamethasone may serve as a novel pharmacologic intervention for heightened fear responses in PTSD. We conducted a double-blind, placebo-controlled trial to test our hypothesis that dexamethasone administration and the concomitant suppression of HPA axis hyperactivity would attenuate fear expression and enhance fear extinction in individuals with PTSD. Study participants (n=62) were recruited from Grady Memorial Hospital in Atlanta, GA. Participants were randomized to receive dexamethasone or placebo prior to fear conditioning and extinction, in a counterbalanced design (treatments separated by a week). Both PTSD- (n=37) and PTSD+ (n=25) participants showed significant startle increases in the presence of the danger signal during placebo and dexamethasone treatments (all pextinction blocks during both conditions (p's≤0.001), with PTSD+ participants showing deficits in fear extinction and safety discrimination in the placebo condition. Notably, extinction and discrimination deficits in PTSD+ subjects were markedly reversed with dexamethasone (pextinction and discrimination in individuals with PTSD. Copyright © 2017 Elsevier Ltd. All rights

  13. 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.

  14. Study of the low-energy ER/NR discrimination and its electric-field dependence with liquid argon

    Science.gov (United States)

    Washimi, T.; Kikuchi, T.; Kimura, M.; Tanaka, M.; Yorita, K.

    2018-02-01

    A two-phase argon detector is generally suitable for the direct detection of weakly interacting massive particle (WIMP) dark matter owing to its high rejection power against electron recoil background events. However, ionization signal (S2) has not been effectively used for argon in current experiments because its basic properties and discrimination power from S2 signal in the low-energy region are not well known, as compared with xenon. The scope of this study is evaluation of S2 properties at a low-energy region of about 40 keVnr and its discrimination power between electron recoils and nuclear recoils based on results from a prototype LAr time projection chamber. The drift-field was varied from null to 3 kV/cm. The detection feasibility for low-mass WIMP with argon is also discussed.

  15. A Preliminary Study of the Core Catcher System on Various Stud Shapes using FLUENT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Uiju; Seo, Gwang Hyeok; Jeun, Gyoodong; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    As a kind of in-vessel retention (IVR) strategies, reactor cavity flooding is used for Westinghouse's AP1000 and South Korea's OPR1000. Moreover, the European Pressurized Reactor (EPR) has adopted an ex-vessel core catcher strategy rather than the IVR strategy. Although the mitigation strategies suggested are vigorously considered, there are still various issues due to its uncertainties and complex phenomena during severe accidents. In this study, to assess the effect of studs installed on the core catcher body, a CFD analysis for coolant channels having rectangular or cylinder shaped studs is carried out. In this study, numerical simulations for the different stud shapes of the core catcher system were carried out using ANSYS FLUENT. For a comparison work, the rectangular and cylinder shaped stud were modeled with the same initial and boundary conditions. The major findings observed from this study can be summarized as follows. - The simulation results showed the 31% reduced amount of pressure drop for the case of the cylinder shaped studs as compared with the reference case, which is for the rectangular studs. - The tendency of reduced pressure drop is well in accord with the flow distribution. The fluid velocities around the studs were greatly distorted for the rectangular studs than those around the cylinder studs. - The distorted stream of fluid could affect heat transfer from core catcher body, and result in locally additional damages. This result may suggest the necessity of finding an optimized stud shape. For more improved comparison work, an additional simulation is planned including different stud shapes.

  16. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Science.gov (United States)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  17. The use of shape memory compression anastomosis clips in cholecystojejunostomy in pigs – a preliminary study

    Directory of Open Access Journals (Sweden)

    Piotr Holak

    2015-01-01

    Full Text Available This paper reports on the use of compression anastomosis clips (CAC in cholecystoenterostomy in an animal model. Cholecystojejunostomy was performed in 6 pigs using implants made of nickel-titanium alloy in the form of elliptical springs with two-way shape memory. The applied procedure led to the achievement of tight anastomosis with a minimal number of complications and positive results of histopathological evaluations of the anastomotic site. The results of the study indicate that shape memory NiTi clips are a promising surgical tool for cholecystoenterostomy in cats and dogs.

  18. Study of influence of radial matcher section end shape on RFQ cavity frequency

    International Nuclear Information System (INIS)

    Zhang Zhouli; He Yuan; Zhang Bin; Shi Aimin; Pan Gang; Du Xiaonan; Sun Liepeng; Li Derun

    2014-01-01

    To investigate the feasibility of using a form cutter to machine the Radial Matcher Section (RMS) of the Radio Frequency Quadrupole (RFQ) for the Accelerator Driven System (ADS) project at Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS), the influence of RMS end shape on the RFQ cavity frequency is studied. The results indicate that using a form cutter to machine the RMS of an RFQ will indeed influence the cavity frequency. The RMS end shape will give more influence to a shorter RFQ cavity. For the 4.2 m ADS RFQ, the influence is negligible, which means that a form cutter can be used to machine the RMS. (authors)

  19. Re-examining the basis for source discrimination and data corrections used by sediment fingerprinting studies in agricultural catchments

    Science.gov (United States)

    Smith, Hugh; Blake, Will

    2014-05-01

    The sediment fingerprinting technique has been widely used in agricultural catchments to quantify fine sediment contributions from various land use sources. This application of the technique depends on the key assumption that land-use source signatures imprinted on catchment soils are decipherable from those due to other landscape factors affecting soil and sediment properties. We re-examine this key assumption by investigating (i) the physical and chemical basis for source discrimination and (ii) potential factors that may confound source un-mixing in agricultural catchments, including particle size and organic matter effects on tracer properties. The study is situated in the River Tamar, a predominantly agricultural catchment in south-west England that has also been affected by mining. Source discrimination focused on pasture and cultivated land uses and channel banks. Monthly, time-integrated suspended sediment samples were collected across seven catchments for a 12-month period. Physical and chemical properties measured in source soils and sediment included fallout radionuclides, major and minor element geochemical constituents, total organic carbon and particle size. Source discrimination was entirely dependent on differences in tracer property concentrations between surface and sub-surface soils. This is based on fallout radionuclide concentrations that are surface-elevated, while many geochemical properties are surface-depleted due to weathering and pedogenetic effects, although surface soil contamination can reverse this trend. Source discrimination in the study catchments was limited by (i) rotation of cultivated and pasture fields resulting in reduced differences between these two sources and (ii) the cultivated source signature resembling a mix of the pasture and channel bank sources for many tracer properties. Furthermore, metal pollution from abandoned historic mines and organic enrichment of sediment from areas of peaty soil resulted in the non

  20. 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.

  1. Shape study of the N=Z waiting-point nucleus 72Kr via beta decay

    CERN Document Server

    Briz Monago, Jose Antonio; Nácher González, Enrique

    The Ph.D. thesis entitled “Shape study of the N=Z waiting-point nucleus 72Kr via beta decay” is devoted to the study of the shape of the ground state of the 72Kr nucleus. It is an N=Z nucleus in the mass region A~70-80 where shape transitions and the shape coexistence phenomena have been identified. Furthermore, this nucleus participates in the rp-process as a waiting point due to the slowdown of the process taking place at the arrival to this nucleus. The study of the properties of this nucleus is interesting from the Nuclear Structure point of view, for the phenomena occurring in its mass region and have been predicted for it, and from the Nuclear Astrophysics for the accurate performance of astrophysical calculations. The β+/EC decay of the 72Kr nucleus has been studied through two complementary experiments at the ISOLDE facility at CERN in Geneva (Switzerland). In one of them, the low-spin structure of the daughter nucleus, 72Br, has been revised via conversion electron spectroscopy where the convers...

  2. Writing Shapes Thinking: Investigative Study of Preservice Teachers Reading, Writing to Learn, and Critical Thinking

    Science.gov (United States)

    Sanchez, Bernice; Lewis, Katie D.

    2014-01-01

    Teacher Preparation Programs must work towards not only preparing preservice teachers to have knowledge of classroom pedagogy but also must expand preservice teachers understanding of content knowledge as well as to develop higher-order thinking which includes thinking critically. This mixed methods study examined how writing shapes thinking and…

  3. Discrimination and Acculturation Stress: A Longitudinal Study of Children's Well-Being from Prenatal Development to 5 Years of Age.

    Science.gov (United States)

    Zeiders, Katharine H; Umaña-Taylor, Adriana J; Jahromi, Laudan B; Updegraff, Kimberly A; White, Rebecca M B

    2016-09-01

    To examine whether cumulative family discrimination and acculturation stress (prenatally to 24 months postpartum) among Mexican-origin adolescent mothers and their mother-figures predicted children's socio-emotional functioning and academic achievement at 5 years of age, and the role of maternal depressive symptoms and mother-child interactions in the association. Mexican-origin families (N = 204) with an adolescent mother, a child, and a mother-figure participated in a 6-wave longitudinal study (2007-2013). Families were recruited and interviewed during the adolescent mother's pregnancy; adolescent mothers, mother-figures, and children were then assessed annually for the next 5 years using a combination of interview-based survey and observational methods. Maternal reports of children's socio-emotional behaviors (measured using the Child Behavior Checklist) and children's academic achievement (assessed with the Woodcock Johnson III Tests of Achievement/Bateria III Woodcock-Muñoz) were used. Structural equation modeling revealed that greater cumulative family discrimination and acculturation stress from pregnancy to 24 months postpartum predicted higher adolescent mothers' depressive symptoms, greater mother-child intrusive interactions, and less mother sensitivity at 36 months postpartum. Maternal depressive symptoms were positively related to children's CBCL symptoms at 60 months postpartum. Greater cumulative discrimination and acculturation stressors directly predicted children's lower Woodcock Johnson/Bateria test scores after accounting for socio-economic status. Mexican-origin adolescent mothers' and mother figures' cumulative discrimination and acculturation stress from pregnancy through children's second birthday predicted children's socio-emotional and academic achievement at age 5. Overall, the findings underscore the cumulative impact of these stressors on well-being in a population with substantial public health significance.

  4. Discrimination of Fearful and Angry Emotional Voices in Sleeping Human Neonates: a Study of the Mismatch Brain Responses

    Directory of Open Access Journals (Sweden)

    Dandan eZhang

    2014-12-01

    Full Text Available Appropriate processing of human voices with different threat-related emotions is of evolutionarily adaptive value for the survival of individuals. Nevertheless, it is still not clear whether the sensitivity to threat-related information is present at birth. Using an oddball paradigm, the current study investigated the neural correlates underlying automatic processing of emotional voices of fear and anger in sleeping neonates. Event-related potential data showed that the frontocentral scalp distribution of the neonatal brain could discriminate fearful voices from angry voices; the mismatch response (MMR was larger in response to the deviant stimuli of anger, compared with the standard stimuli of fear. Furthermore, this fear-anger MMR discrimination was observed only when neonates were in active sleep state. Although the neonates’ sensitivity to threat-related voices is not likely associated with a conceptual understanding of fearful and angry emotions, this special discrimination in early life may provide a foundation for later emotion and social cognition development.

  5. Study on non-linear bistable dynamics model based EEG signal discrimination analysis method.

    Science.gov (United States)

    Ying, Xiaoguo; Lin, Han; Hui, Guohua

    2015-01-01

    Electroencephalogram (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations generating from ionic current flows within the neurons of the brain. EEG signal is looked as one of the most important factors that will be focused in the next 20 years. In this paper, EEG signal discrimination based on non-linear bistable dynamical model was proposed. EEG signals were processed by non-linear bistable dynamical model, and features of EEG signals were characterized by coherence index. Experimental results showed that the proposed method could properly extract the features of different EEG signals.

  6. A Bayesian Stepwise Discriminant Model for Predicting Risk Factors of Preterm Premature Rupture of Membranes: A Case-control Study.

    Science.gov (United States)

    Zhang, Li-Xia; Sun, Yang; Zhao, Hai; Zhu, Na; Sun, Xing-De; Jin, Xing; Zou, Ai-Min; Mi, Yang; Xu, Ji-Ru

    2017-10-20

    Preterm premature rupture of membrane (PPROM) can lead to serious consequences such as intrauterine infection, prolapse of the umbilical cord, and neonatal respiratory distress syndrome. Genital infection is a very important risk which closely related with PPROM. The preliminary study only made qualitative research on genital infection, but there was no deep and clear judgment about the effects of pathogenic bacteria. This study was to analyze the association of infections with PPROM in pregnant women in Shaanxi, China, and to establish Bayesian stepwise discriminant analysis to predict the incidence of PPROM. In training group, the 112 pregnant women with PPROM were enrolled in the case subgroup, and 108 normal pregnant women in the control subgroup using an unmatched case-control method. The sociodemographic characteristics of these participants were collected by face-to-face interviews. Vaginal excretions from each participant were sampled at 28-36+6 weeks of pregnancy using a sterile swab. DNA corresponding to Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU), Candida albicans, group B streptococci (GBS), herpes simplex virus-1 (HSV-1), and HSV-2 were detected in each participant by real-time polymerase chain reaction. A model of Bayesian discriminant analysis was established and then verified by a multicenter validation group that included 500 participants in the case subgroup and 500 participants in the control subgroup from five different hospitals in the Shaanxi province, respectively. The sociological characteristics were not significantly different between the case and control subgroups in both training and validation groups (all P > 0.05). In training group, the infection rates of UU (11.6% vs. 3.7%), CT (17.0% vs. 5.6%), and GBS (22.3% vs. 6.5%) showed statistically different between the case and control subgroups (all P case and control subgroups (P case and control subgroup were 84.1% and 86.8% in the training and validation groups, respectively

  7. Hearing shapes of few electrons quantum drums: A configuration–interaction study

    Energy Technology Data Exchange (ETDEWEB)

    Ţolea, F.; Ţolea, M., E-mail: tzolea@infim.ro

    2015-02-01

    The – highly remarkable – existence of non-congruent yet vibrationally isospectral shapes has been first proved theoretically and then also tested experimentally – by using electromagnetic waves in cavities, vibrating smectic films or electrons in nanostructures. In this context, we address the question whether isospectrality holds if two or more electrons interact electrostatically, using the accurate configuration–interaction method, in a discrete representation of the Bilby and Hawk shapes. Isospectral pairs offer an unique possibility to test how identical sets of single-particle energies may combine differently in the few-electrons eigenmodes, due to different wave functions spatial distributions. Our results point towards the break down of isospectrality in the presence of interactions. Thus one should be able to ”hear” the shapes of few electrons quantum drums. Interestingly however, for the analyzed two and three electrons cases, there exists an interaction strength (which can be tuned by changing the size of the shapes), for which the ground states energies of Bilby and Hawk coincide, but not the excited states as well. Wigner localization is studied and shown to occur at about the same size for both Bilby and Hawk shapes. Next, an exercise is proposed to use the two-electrons charge density of the Bilby and Hawk ground states in the phase extraction scheme as proposed by Moon et al. (2008). Results show that out-of-phase regions appear if the linear size of the shapes exceeds the Bohr radius as occupation of higher Slater determinants becomes significant.

  8. Hearing shapes of few electrons quantum drums: A configuration–interaction study

    International Nuclear Information System (INIS)

    Ţolea, F.; Ţolea, M.

    2015-01-01

    The – highly remarkable – existence of non-congruent yet vibrationally isospectral shapes has been first proved theoretically and then also tested experimentally – by using electromagnetic waves in cavities, vibrating smectic films or electrons in nanostructures. In this context, we address the question whether isospectrality holds if two or more electrons interact electrostatically, using the accurate configuration–interaction method, in a discrete representation of the Bilby and Hawk shapes. Isospectral pairs offer an unique possibility to test how identical sets of single-particle energies may combine differently in the few-electrons eigenmodes, due to different wave functions spatial distributions. Our results point towards the break down of isospectrality in the presence of interactions. Thus one should be able to ”hear” the shapes of few electrons quantum drums. Interestingly however, for the analyzed two and three electrons cases, there exists an interaction strength (which can be tuned by changing the size of the shapes), for which the ground states energies of Bilby and Hawk coincide, but not the excited states as well. Wigner localization is studied and shown to occur at about the same size for both Bilby and Hawk shapes. Next, an exercise is proposed to use the two-electrons charge density of the Bilby and Hawk ground states in the phase extraction scheme as proposed by Moon et al. (2008). Results show that out-of-phase regions appear if the linear size of the shapes exceeds the Bohr radius as occupation of higher Slater determinants becomes significant

  9. Genome-Wide Association Study on Male Genital Shape and Size in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Baku Takahara

    Full Text Available Male genital morphology of animals with internal fertilization and promiscuous mating systems have been one of the most diverse and rapidly evolving morphological traits. The male genital morphology in general is known to have low phenotypic and genetic variations, but the genetic basis of the male genital variation remains unclear. Drosophila melanogaster and its closely related species are morphologically very similar, but the shapes of the posterior lobe, a cuticular projection on the male genital arch are distinct from each other, representing a model system for studying the genetic basis of male genital morphology. In this study, we used highly inbred whole genome sequenced strains of D. melanogaster to perform genome wide association analysis on posterior lobe morphology. We quantified the outline shape of posterior lobes with Fourier coefficients obtained from elliptic Fourier analysis and performed principal component analysis, and posterior lobe size. The first and second principal components (PC1 and PC2 explained approximately 88% of the total variation of the posterior lobe shape. We then examined the association between the principal component scores and posterior lobe size and 1902142 single nucleotide polymorphisms (SNPs. As a result, we obtained 15, 14 and 15 SNPs for PC1, PC2 and posterior lobe size with P-values smaller than 10(-5. Based on the location of the SNPs, 13, 13 and six protein coding genes were identified as potential candidates for PC1, PC2 and posterior lobe size, respectively. In addition to the previous findings showing that the intraspecific posterior shape variation are regulated by multiple QTL with strong effects, the present study suggests that the intraspecific variation may be under polygenic regulation with a number of loci with small effects. Further studies are required for investigating whether these candidate genes are responsible for the intraspecific posterior lobe shape variation.

  10. Hyperspectral image analysis for rapid and accurate discrimination of bacterial infections: A benchmark study.

    Science.gov (United States)

    Arrigoni, Simone; Turra, Giovanni; Signoroni, Alberto

    2017-09-01

    With the rapid diffusion of Full Laboratory Automation systems, Clinical Microbiology is currently experiencing a new digital revolution. The ability to capture and process large amounts of visual data from microbiological specimen processing enables the definition of completely new objectives. These include the direct identification of pathogens growing on culturing plates, with expected improvements in rapid definition of the right treatment for patients affected by bacterial infections. In this framework, the synergies between light spectroscopy and image analysis, offered by hyperspectral imaging, are of prominent interest. This leads us to assess the feasibility of a reliable and rapid discrimination of pathogens through the classification of their spectral signatures extracted from hyperspectral image acquisitions of bacteria colonies growing on blood agar plates. We designed and implemented the whole data acquisition and processing pipeline and performed a comprehensive comparison among 40 combinations of different data preprocessing and classification techniques. High discrimination performance has been achieved also thanks to improved colony segmentation and spectral signature extraction. Experimental results reveal the high accuracy and suitability of the proposed approach, driving the selection of most suitable and scalable classification pipelines and stimulating clinical validations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments

    Science.gov (United States)

    Charpentier, Isabelle; Staszyc, Alicia B.; Wellner, Julia S.; Alejandro, Vanessa

    2017-06-01

    As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a 100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.

  12. Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments

    Directory of Open Access Journals (Sweden)

    Charpentier Isabelle

    2017-01-01

    Full Text Available As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a ~100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.

  13. 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

  14. Self-Reported Discrimination in Health-Care Settings Based on Recognizability as Transgender: A Cross-Sectional Study Among Transgender U.S. Citizens.

    Science.gov (United States)

    Rodriguez, Amanda; Agardh, Anette; Asamoah, Benedict Oppong

    2018-05-01

    Discrimination has long been tied to health inequality. Rejected by families and communities because of their gender identity and gender-role behavior, transgender individuals are often socially marginalized. This study aimed to assess discrimination in health-care settings among persons self-identifying as transgender in the U.S. in relation to their recognizability as transgender, operationalized as how often they experienced that others recognized them as transgender. Data were obtained from the National Transgender Discrimination Survey (n = 6106 participants, assigned sex at birth = 3608 males, 2480 females, respectively). Binary logistic regressions were performed to examine associations between transgender recognizability and discrimination in health-care settings. Being recognized as transgender to any extent had a significant effect on perceived discrimination in health care. Always recognized as transgender showed significant associations with discrimination in a health-care setting (OR 1.48) and the following individualized health-care settings: social service settings (rape crisis and domestic violence centers, OR 5.22) and mental health settings (mental health clinic and drug treatment program, OR 1.87). Sex work and other street economy, which are known experiential factors affected by discrimination, were also significantly associated with discrimination in health-care settings. Discrimination in health-care settings is pervasive for transgender who are recognized as transgender. Public health efforts to improve access to equitable health care for transgender individuals may benefit from consideration of demographic, experiential, and medical risk factors to more fully understand the source of the seemingly excess risk of discrimination among persons recognized by others as being transgender.

  15. 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.

  16. 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.

  17. Study of different cross-shaped microchannels affecting thermal-bubble-actuated microparticle manipulation

    Science.gov (United States)

    Li, Weichen; Tsou, Chingfu

    2015-10-01

    This paper presents a thermal-bubble-actuated microfluidic chip with cross-shaped microchannels for evaluating the effect of different microchannel designs on microparticle manipulation. Four cross-shaped microchannel designs, with orthogonal, misaligned, skewed, and antiskewed types, were proposed in this study. The thermal bubble micropump, which is based on a resistive bulk microheater, was used to drive fluid transportation, and it can be realized using a simple microfabrication process with a silicon-on-isolator wafer. Using commercial COMSOL software, the flow profiles of microfluidics in various cross-shaped microchannels were simulated qualitatively under different pumping pressures. Microbeads, with a diameter of 20 μm, manipulated in four cross-shaped microchannels, were also implemented in this experiment. The results showed that a skewed microchannel design has a higher sorting rate compared with orthogonal, misaligned, and antiskewed microchannels because its flow velocity in the main microchannel is significantly reduced by pumping pressure. Typically, the successful sorting rate for this type of skewed microchannel can reach 30% at a pumping frequency of 100 Hz.

  18. Study on Effects of The Shape of Cavitator on Supercavitation Flow Field Characteristics

    Science.gov (United States)

    Wang, Rui; Dang, Jianjun; Yao, Zhong

    2018-03-01

    The cavitator is the key part of the nose of the vehicle to induce the formation of supercavity, which has an important influence in the cavity formation rate, cavity shape and cavity stability. To study the influence of the shape on the supercavitation flew field characteristics, the cavity characteristics and the resistance characteristics of different shapes of cavitator under different working conditions are obtained by combining technical methods of numerical simulation and experimental research in water tunnel. The simulation results are contrast and analyzed with the test results. The analysis results show that : in terms of the cavity size, the inverted-conic cavitator can form the biggest cavity size, followed by the disk cavitator, and the truncated-conic cavitator is the least; in terms of the cavity formation speed, the inverted-conic cavitator has the fastest cavity formation speed, then is the truncated-conic cavitator, and the disk cavitator is the least; in terms of the drag characteristic, the truncated-conic cavitator has the maximum coefficient, disk cavitator is the next, the inverted-conic cavitator is the minimal. The research conclusion can provide reference and basis for the head shape design of supercavitating underwater ordnance and the design of hydrodynamic layout.

  19. Study of droplet flow in a T-shape microchannel with bottom wall fluctuation

    Science.gov (United States)

    Pang, Yan; Wang, Xiang; Liu, Zhaomiao

    2018-03-01

    Droplet generation in a T-shape microchannel, with a main channel width of 50 μm , side channel width of 25 μm, and height of 50 μm, is simulated to study the effects of the forced fluctuation of the bottom wall. The periodic fluctuations of the bottom wall are applied on the near junction part of the main channel in the T-shape microchannel. Effects of bottom wall's shape, fluctuation periods, and amplitudes on the droplet generation are covered in the research of this protocol. In the simulation, the average size is affected a little by the fluctuations, but significantly by the fixed shape of the deformed bottom wall, while the droplet size range is expanded by the fluctuations under most of the conditions. Droplet sizes are distributed in a periodic pattern with small amplitude along the relative time when the fluctuation is forced on the bottom wall near the T-junction, while the droplet emerging frequency is not varied by the fluctuation. The droplet velocity is varied by the bottom wall motion, especially under the shorter period and the larger amplitude. When the fluctuation period is similar to the droplet emerging period, the droplet size is as stable as the non-fluctuation case after a development stage at the beginning of flow, while the droplet velocity is varied by the moving wall with the scope up to 80% of the average velocity under the conditions of this investigation.

  20. 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).

  1. A qualitative study on discrimination and ethical implications in stroke care in contemporary Greece.

    Science.gov (United States)

    Theofanidis, Dimitrios

    2015-12-01

    Contemporary stroke care is diverse, contributing to complex ethical dilemmas and controversies. In Greece, continuing austerity measures and an ageing population are expected to increase the burden of stroke on health care delivery. We sought to explore ethical views and stances of health care professionals caring for stroke patients in Greece. Forms of discrimination against elderly hospitalized patients were also addressed. A qualitative design was adopted whereby an informal focus group interview and follow-up, face-to-face individual interviews were undertaken. The sample consisted of 12 nurses working in clinical areas with stroke patients. Their mean age was 31 years with a mean work experience of 10 years. Individual discussions were audio taped after subject consent and were transcribed verbatim subsequently for keywords-in-context analysis. Analysis of the focus interview revealed several recurring themes, namely, ward destination, admission policies, the concepts of age as related to stroke. Individual interviews highlighted several other topics, such as preferences for specific types of patients, communication capacity of the patient's condition, and his or her individual characteristics as a favoring or limiting factors, and challenges to age-related criteria for treatment. There is an age-related criteria of 65 years for ward destination after stroke as set by a ministerial decree, which is still practiced. Moreover, younger stroke patients may be offered more thorough assessments and clinical tests and therapies. Discrepancies in the level of care pose an ethical concern regarding levels of care for older stroke patients in Greece. A longstanding, age-related national policy in Greece regarding hospital admission criteria is shown to be a detrimental influence on ward admission for stroke patients. This policy, coupled with prehospital care protocols, was shown to promote ageism against this patient group. The age-related agenda in the Greek health

  2. Study on Dissipation of Landslide Generated Waves in Different Shape of Reservoirs

    Science.gov (United States)

    An, Y.; Liu, Q.

    2017-12-01

    The landslide generated waves are major risks for many reservoirs located in mountainous areas. As the initial wave is often very huge (e.g. 30m of the height in Xiaowan event, 2009, China), the dissipation of the wave, which is closely connected with the shape of the reservoir (e.g. channel type vs. lake type), is a crucial factor in risk estimation and prevention. While even for channel type reservoir, the wave damping also varies a lot due to details of the shape such as branches and turnings. Focusing on the influence of this shape details on the wave damping in channel type reservoir, we numerically studied two landslide generated wave events with both a triangle shape of the cross section but different longitudinal shape configurations (Xiaowan event in 2009 and an assuming event in real topography). The two-dimensional Saint-Venant equation and dry-wet boundary treatment method are used to simulate the wave generation and propagation processes. The simulation is based on an open source code called `Basilisk' and the adaptive mesh refinement technique is used to achieve enough precision with affordable computational resources. The sensitivity of the parameters representing bed drag and the vortex viscosity is discussed. We found that the damping is relatively not sensitive to the bed drag coefficient, which is natural as the water depth is large compared with wave height. While the vortex viscosity needs to be chosen carefully as it is related to cross sectional velocity distribution. It is also found that the longitudinal shape, i.e. the number of turning points and branches, is the key factor influencing the wave damping. The wave height at the far field could be only one seventh comparing with the initial wave in the case with complex longitudinal shape, while the damping is much weaker in the straight channel case. We guess that this phenomenon is due to the increasing sloshing at these abruptly changed positions. This work could provide a deeper

  3. Three-dimensional quantitative analysis of healthy foot shape: a proof of concept study.

    Science.gov (United States)

    Stanković, Kristina; Booth, Brian G; Danckaers, Femke; Burg, Fien; Vermaelen, Philippe; Duerinck, Saartje; Sijbers, Jan; Huysmans, Toon

    2018-01-01

    Foot morphology has received increasing attention from both biomechanics researches and footwear manufacturers. Usually, the morphology of the foot is quantified by 2D footprints. However, footprint quantification ignores the foot's vertical dimension and hence, does not allow accurate quantification of complex 3D foot shape. The shape variation of healthy 3D feet in a population of 31 adult women and 31 adult men who live in Belgium was studied using geometric morphometric methods. The effect of different factors such as sex, age, shoe size, frequency of sport activity, Body Mass Index (BMI), foot asymmetry, and foot loading on foot shape was investigated. Correlation between these factors and foot shape was examined using multivariate linear regression. The complex nature of a foot's 3D shape leads to high variability in healthy populations. After normalizing for scale, the major axes of variation in foot morphology are (in order of decreasing variance): arch height, combined ball width and inter-toe distance, global foot width, hallux bone orientation (valgus-varus), foot type (e.g. Egyptian, Greek), and midfoot width. These first six modes of variation capture 92.59% of the total shape variation. Higher BMI results in increased ankle width, Achilles tendon width, heel width and a thicker forefoot along the dorsoplantar axis. Age was found to be associated with heel width, Achilles tendon width, toe height and hallux orientation. A bigger shoe size was found to be associated with a narrow Achilles tendon, a hallux varus, a narrow heel, heel expansion along the posterior direction, and a lower arch compared to smaller shoe size. Sex was found to be associated with differences in ankle width, Achilles tendon width, and heel width. Frequency of sport activity was associated with Achilles tendon width and toe height. A detailed analysis of the 3D foot shape, allowed by geometric morphometrics, provides insights in foot variations in three dimensions that can not be

  4. Discrimination Factors and Incorporation Rates for Organic Matrix in Shark Teeth Based on a Captive Feeding Study.

    Science.gov (United States)

    Zeichner, S S; Colman, A S; Koch, P L; Polo-Silva, C; Galván-Magaña, F; Kim, S L

    Sharks migrate annually over large distances and occupy a wide variety of habitats, complicating analysis of lifestyle and diet. A biogeochemical technique often used to reconstruct shark diet and environment preferences is stable isotope analysis, which is minimally invasive and integrates through time and space. There are previous studies that focus on isotopic analysis of shark soft tissues, but there are limited applications to shark teeth. However, shark teeth offer an advantage of multiple ecological snapshots and minimum invasiveness during removal because of their distinct conveyor belt tooth replacement system. In this study, we analyze δ 13 C and δ 15 N values of the organic matrix in leopard shark teeth (Triakis semifasciata) from a captive experiment and report discrimination factors as well as incorporation rates. We found differences in tooth discrimination factors for individuals fed different prey sources (mean ± SD; Δ 13 C squid = 4.7‰ ± 0.5‰, Δ 13 C tilapia = 3.1‰ ± 1.0‰, Δ 15 N squid = 2.0‰ ± 0.7‰, Δ 15 N tilapia = 2.8‰ ± 0.6‰). In addition, these values differed from previously published discrimination factors for plasma, red blood cells, and muscle of the same leopard sharks. Incorporation rates of shark teeth were similar for carbon and nitrogen (mean ± SE; λ C = 0.021 ± 0.009, λ N = 0.024 ± 0.007) and comparable to those of plasma. We emphasize the difference in biological parameters on the basis of tissue substrate and diet items to interpret stable isotope data and apply our results to stable isotope values from blue shark (Prionace glauca) teeth to illustrate the importance of biological parameters to interpret the complex ecology of a migratory shark.

  5. Study of n-γ discrimination with NE213 and BC501A liquid scintillators of different size

    International Nuclear Information System (INIS)

    Moszynski, M.; Costa, G.J.; Guillaume, G.; Heusch, B.; Huck, A.; Mouatassim, S.

    1994-01-01

    A comparative study of n-γ discrimination by the digital charge comparison method was carried out for NE213 and BC501A scintillators of different size coupled to a 130 mm diameter XP4512B photomultiplier. Particularly, the scintillators of diameter 50 mmx50 mm size are compared with those of 4 l volume (160 mm in diameter and 200 mm in depth). The figure of merit, M, of 3.81 measured with the diameter 50 mmx50 mm BC501A scintillator at 1 MeV energy lost by recoil electrons, is much better than M of 2.05 as observed with the 4 l volume cell. This is the effect of the reduced photoelectron yield by about 50% determined for the 4 l volume scintillator. Moreover, the slowing down of the light pulse and multiscattering of neutrons have a further influence on the lowering of the M factor. The study of the M factor versus the initial delay and width of the gate set at the slow component showed that the early light of the slow component represented often by the intermediate component with the decay time constant of about 30 ns is of great importance for the n-γ discrimination. Particularly, for the 4 l volume cells it is sufficient to limit the width of the gate at the slow component to about 300 ns. The comparison of the NE213 and BC501A scintillators showed that the BC501A scintillator exhibits a larger light yield evidently observed for the 4 l volume cell and thus giving a better n-γ discrimination. ((orig.))

  6. 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

  7. 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

  8. Study on mechanical properties of laminated rubber bearing with small shape factor

    International Nuclear Information System (INIS)

    Mazda, T.; Ootori, Y.; Yabana, S.; Hirata, K.; Ishida, K.

    1995-01-01

    Laminated rubber bearings with a small shape factor are regarded as one of the most promising isolation devices to reduce the vertical seismic load of a nuclear power plant. In this study, three types of natural rubber bearings with different aspect ratios (diameter/total thickness of rubber) and one high-damping rubber bearing are tested under varied loading conditions. Basic characteristics and ultimate characteristics of the bearings are made clear, and applicability of estimation formula and analysis method are verified

  9. Shape coexistence in the lightest Tl isotopes studied by laser spectroscopy

    CERN Multimedia

    Herfurth, F; Antalic, S; Darby, I G; Venhart, M; Flanagan, K; Veselsky, M; Blaum, K; Radulov, D P; Beck, D; Kowalska, M; Schwarz, S; Chapman, R; Diriken, J V J; Lane, J; Rosenbusch, M

    This proposal aims at atomic spectroscopy studies of the very neutron-deficient isotopes $^{178-187}$Tl, at and far beyond the region of the neutron mid-shell at N=104, in which shape coexistence phenomena were investigated so far by particle and $\\gamma$-ray spectroscopy methods only. Our motivation for this proposal is as follows : \\\\\\\\ -These studies will provide direct data on magnetic dipole moment, spin, charge radii and deformations of these isotopes. The results will form a stringent test for our current understanding of the shape coexistence phenomena in the vicinity of the neutron mid-shell at N=104, where the relevant effects are expected to be the strongest (cf.shape staggering in the isotopes $^{181,183,185}$Hg). \\\\-The knowledge of the structure (configuration, spin, deformation) and whether one or two $\\beta$-decaying isomers are present in the parent isotopes $^{178,180,182}$Tl are crucial for understanding of the results of our recent studies of $\\beta$-delayed fission in the lightest thalli...

  10. Neural indices of phonemic discrimination and sentence-level speech intelligibility in quiet and noise: A P3 study.

    Science.gov (United States)

    Koerner, Tess K; Zhang, Yang; Nelson, Peggy B; Wang, Boxiang; Zou, Hui

    2017-07-01

    This study examined how speech babble noise differentially affected the auditory P3 responses and the associated neural oscillatory activities for consonant and vowel discrimination in relation to segmental- and sentence-level speech perception in noise. The data were collected from 16 normal-hearing participants in a double-oddball paradigm that contained a consonant (/ba/ to /da/) and vowel (/ba/ to /bu/) change in quiet and noise (speech-babble background at a -3 dB signal-to-noise ratio) conditions. Time-frequency analysis was applied to obtain inter-trial phase coherence (ITPC) and event-related spectral perturbation (ERSP) measures in delta, theta, and alpha frequency bands for the P3 response. Behavioral measures included percent correct phoneme detection and reaction time as well as percent correct IEEE sentence recognition in quiet and in noise. Linear mixed-effects models were applied to determine possible brain-behavior correlates. A significant noise-induced reduction in P3 amplitude was found, accompanied by significantly longer P3 latency and decreases in ITPC across all frequency bands of interest. There was a differential effect of noise on consonant discrimination and vowel discrimination in both ERP and behavioral measures, such that noise impacted the detection of the consonant change more than the vowel change. The P3 amplitude and some of the ITPC and ERSP measures were significant predictors of speech perception at segmental- and sentence-levels across listening conditions and stimuli. These data demonstrate that the P3 response with its associated cortical oscillations represents a potential neurophysiological marker for speech perception in noise. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Study of the matrix specific mass discrimination effects during inductively coupled plasma mass spectrometry isotope ratio measurements

    International Nuclear Information System (INIS)

    Vassileva, E.; Quetel, Ch.R.

    2004-01-01

    Sample matrix related effects on mass discrimination during inductively coupled plasma mass spectrometry (ICP-MS) isotope ratio measurements have only been rarely reported. However, they can lead to errors larger than the uncertainty claimed on the ratio results when not properly taken into account or corrected for. These matrix specific affects were experienced during an Isotope Dilution Mass Spectrometry (IDMS) campaign we carried out for the certification of the Cd amount content in some food digest samples (7% acidity and salts content around 450μg g -1 ). Dilution was not possible for Cd only present at the low ng g -1 level. Up to 1% difference was observed on Cd isotope ratio results between measurements performed directly or after matrix separation. This was a significant difference considering that less than 1.5% relative combined uncertainty was eventually estimated for these IDMS measurements. Similar results could be obtained either way after the implementation of necessary corrections. The direct measurement approach associated to a correction for mass discrimination effects using the food digest sample itself (and the IUPAC table values as reference for the natural Cd isotopic composition) was preferred as it was the easiest. Consequently, the impact of matrix effects on mass discrimination during isotope ratio measurements with two types of ICP- MS (quadrupole and magnetic sector instruments) was studied for 4 elements (Li, Cu, Cd and Tl). Samples of varying salinity (up to 0.25%) and acidity (up to 7%) characteristics were prepared using isotopic certified reference materials of these elements. The long term and short-term stability, respectively reproducibility and repeatability, of the results, as well as the evolution of the difference to certified ratio values were monitored. As expected the 13 investigated isotopic ratios were all sensitive to variations in salt and acid concentrations. Our experiments also showed that simultaneous variation

  12. Changes in body weight, composition, and shape: a 4-year study of college students.

    Science.gov (United States)

    Gropper, Sareen S; Simmons, Karla P; Connell, Lenda Jo; Ulrich, Pamela V

    2012-12-01

    The objectives of this study were to examine changes in body weight, body mass index (BMI), body composition, and shape in a group of male and female students over the 4-year college period. Anthropometric assessments including height and weight (via standard techniques), body composition (via bioelectrical impedance analysis), and body shape (via 3-dimensional body scanning) were conducted at the beginning of the freshman year and end of the senior year in 131 college students. Four-year changes included significant (p obese increased from 18% to 31%. The number of females and males with ≥30% and 20% body fat, respectively, increased from n = 14 to n = 26 (with n = 4 exhibiting normal weight obesity) over the 4-year period. The waist circumference changes were significantly (p obesity and normal weight obesity among this college population suggests the need for additional health promotion strategies on college campuses.

  13. Numerical study on human model shape and grid dependency for indoor thermal comfort evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jin Won; Choi, Yun Ho [Ajou University, Suwon (Korea, Republic of); Park, Jae Hong [LIG Nexl Co. Ltd, Seongnam (Korea, Republic of)

    2013-02-15

    Various computer-simulated person (CSP) models have been used to represent occupants in indoor airflow simulations using computational fluid dynamics (CFD). Despite the capability of CFD to predict temperature and velocity fields in an automotive cabin or a room in a building, it is more difficult to evaluate the degree of thermal comfort considered by the CSP models. Up to now, the shapes of CSP models and their grid characteristics have not been studied for the evaluation of indoor thermal comfort. In this paper, the effects of the human model's shape and the physical characteristics of the grids are studied. The FLUENT code is used for analysis, and the predicted mean vote (PMV), predicted percentage dissatisfied (PPD), and equivalent homogeneous temperature (EHT) values are used for the evaluation and comparison of thermal comfort. The computational results show that the CSP shape and grid features do not affect the global flow fields or the evaluations of PMV and PPD. However, more precise results are obtained from the evaluation of thermal comfort by EHT when detailed human models with a prism grid are used.

  14. Numerical study on human model shape and grid dependency for indoor thermal comfort evaluation

    International Nuclear Information System (INIS)

    Seo, Jin Won; Choi, Yun Ho; Park, Jae Hong

    2013-01-01

    Various computer-simulated person (CSP) models have been used to represent occupants in indoor airflow simulations using computational fluid dynamics (CFD). Despite the capability of CFD to predict temperature and velocity fields in an automotive cabin or a room in a building, it is more difficult to evaluate the degree of thermal comfort considered by the CSP models. Up to now, the shapes of CSP models and their grid characteristics have not been studied for the evaluation of indoor thermal comfort. In this paper, the effects of the human model's shape and the physical characteristics of the grids are studied. The FLUENT code is used for analysis, and the predicted mean vote (PMV), predicted percentage dissatisfied (PPD), and equivalent homogeneous temperature (EHT) values are used for the evaluation and comparison of thermal comfort. The computational results show that the CSP shape and grid features do not affect the global flow fields or the evaluations of PMV and PPD. However, more precise results are obtained from the evaluation of thermal comfort by EHT when detailed human models with a prism grid are used.

  15. Study of identification of geometrically shaped solids using colour and range information

    International Nuclear Information System (INIS)

    Ebihara, Kenichi

    1997-05-01

    This report is the revision of the Technical Report (MECSE 1996-7) of Monash University in Melbourne, Australia which has been distributed to the Department Library in this University. The main work which is described in this report was carried out at Intelligent Robotics Research Center (IRRC) in the Department of Electrical and Computer Systems Engineering of Monash University from March in 1995 to March in 1996 and was be supported by a grant from Research Development Corporation of Japan (JRDC). This report describes the study of identification of geometrically shaped solids with unique colour using colour and range information. This study aims at recognition of equipment in nuclear plants. For this purpose, it is hypothesized that equipment in nuclear plants can be represented by combination of geometrically shaped solids with unique colour, such as a sphere, an ellipsoid, a cone, a cylinder, a rectangular solid and a pyramid. In this report, the colour image of geometrically shaped solids could be segmented comparatively easily and effectively into regions of each solid by using colour and range information. The range data of each solid was extracted using the segmented colour image. Thus the extracted range data could be classified into a plane surface or a curved surface by checking its spatial distribution. (author)

  16. Organizational culture shapes the adoption and incorporation of simulation into nursing curricula: a grounded theory study.

    Science.gov (United States)

    Taplay, Karyn; Jack, Susan M; Baxter, Pamela; Eva, Kevin; Martin, Lynn

    2014-01-01

    Purpose. To create a substantive mid-range theory explaining how the organizational cultures of undergraduate nursing programs shape the adoption and incorporation of mid-to high-level technical fidelity simulators as a teaching strategy within curricula. Method. A constructivist grounded theory was used to guide this study which was conducted in Ontario, Canada, during 2011-12. Semistructured interviews (n = 43) with participants that included nursing administrators, nursing faculty, and simulation leaders across multiple programs (n = 13) informed this study. Additionally, key documents (n = 67) were reviewed. Purposeful and theoretical sampling was used and data were collected and analyzed simultaneously. Data were compared among and between sites. Findings. The organizational elements that shape simulation in nursing (OESSN) model depicts five key organizational factors at the nursing program level that shaped the adoption and incorporation of simulation: (1) leaders working in tandem, (2) information exchange, (3) physical locale, (4) shared motivators, and (5) scaffolding to manage change. Conclusions. The OESSN model provides an explanation of the organizational factors that contributed to the adoption and incorporation of simulation into nursing curricula. Nursing programs that use the OESSN model may experience a more rapid or broad uptake of simulation when organizational factors that impact adoption and incorporation are considered and planned for.

  17. Effect of Particle Shape on Mechanical Behaviors of Rocks: A Numerical Study Using Clumped Particle Model

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Zhou, Chuang-bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied. PMID:23997677

  18. Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

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

    Science.gov (United States)

    Wever, D J; Elstrodt, J A; Veldhuizen, A G; v Horn, J R

    2002-04-01

    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. An originally curved squared rod, in the cold condition, was straightened and fixed to the spine with pedicle screws. Peroperatively, the memory effect of the rod was activated by heating the rod to 50 degrees C by a low-voltage, high-frequency current. After 3 and after 6 months the animals were sacrificed. The first radiographs, obtained immediately after surgery, showed in all animals an induced curve of about 40 degrees Cobb angle - the original curve of the rod. This curve remained constant during the follow-up. The postoperative serum nickel measurements were around the detection limit, and were not significantly higher compared to the preoperative nickel concentration. Macroscopic inspection after 3 and 6 months showed that the device was almost overgrown with newly formed bone. Corrosion and fretting processes were not observed. Histologic examination of the sections of the surrounding tissues and sections of the lung, liver, spleen and kidney showed no evidence of a foreign body response. In view of the initiation of the scoliotic deformation, it is expected that the shape-memory metal based scoliosis correction device also has the capacity to correct a scoliotic curve. Moreover, it is expected that the new device will show good biocompatibility in clinical application. Extensive fatigue testing of the whole system should be performed before clinical trials are initiated.

  20. Prevalence and mental health correlates of harassment and discrimination in the workplace: results from a national study.

    Science.gov (United States)

    Rospenda, Kathleen M; Richman, Judith A; Shannon, Candice A

    2009-05-01

    This study describes past-year prevalence and effects on mental health and drinking outcomes for harassment and discrimination in the workplace (HDW) in a nationally representative random digit dial phone survey conducted in 2003-2004 (n = 2,151). HDW measures included experiences and perceptions of sexual harassment (SH) and generalized workplace harassment (GWH), and perceived harassment or discrimination because of race or ethnicity. Prevalence was examined by sex, race, age, occupation, marital status, and education. Effects of HDW were assessed controlling for demo-graphics and job and life stressors. Experiencing multiple types of HDW was common. SH was more prevalent among women, and Blacks and those of other or mixed race or ethnicity experienced the highest levels of HDW overall. HDW variables explained additional variance in problem drinking and mental health beyond life and job stressors, particularly for women. This study demonstrates that HDW is a prevalent problem associated with poor mental health and problem drinking in the U.S. workforce.

  1. Theoretical study of the effect of probe shape on adhesion force between probe and substrate in atomic force microscope experiment

    OpenAIRE

    Yang, Li; Hu, Junhui; Kong, Lingjiang

    2017-01-01

    The quantitative description of adhesion force dependence on the probe shapes are of importance in many scientific and industrial fields. In order to elucidate how the adhesion force varied with the probe shape in atomic force microscope manipulation experiment, we performed a theoretical study of the influences of the probe shape (the sphere and parabolic probe) on the adhesion force at different humidity. We found that the combined action of the triple point and the Kelvin radius guiding th...

  2. Shape-coexistence and shape-evolution studies for bismuth isotopes by insource laser spectroscopy and $\\beta$-delayed fission in $^{188}$Bi

    CERN Multimedia

    The proposal aims at the two main goals: \\\\ \\\\1) the studies of shape-coexistence and shape-evolution phenomena in the long chain of bismuth isotopes (Z=83) by in-source laser spectroscopy measurements of isotopic shifts (IS) and hyperfine structures (hfs), and \\\\ 2) $\\beta$-delayed fission ($\\beta$DF) of two isomeric states in $^{188}$Bi. \\\\ \\\\Isomer-selective $\\beta$DF studies for $^{188m1, 188m2}$Bi isomers will enable us for the first time to investigate the spin-dependence of the $\\beta$DF process and to check theoretical predictions of asymmetrical fission fragment mass-distribution in this region of nuclei. The measurements will be performed with the well-proven Windmill and MR-TOF MS/Penning Trap techniques.

  3. Influence of culture and discrimination on care-seeking behavior of elderly African Americans: a qualitative study.

    Science.gov (United States)

    Martin, Shadi S; Trask, Jacqueline; Peterson, Tina; Martin, Bryan C; Baldwin, Josh; Knapp, Matthew

    2010-05-01

    In this study, the influence of culture and discrimination on care-seeking behavior of elderly African Americans was explored. This was a qualitative phenomenological study that involved in-depth interviews with 15 African American men and women aged 60 and older in Alabama. The sample size of 15 was adequate for the phenomenological method of this study. While this was a small exploratory study and was not intended for any generalizations, it did provide a unique opportunity to hear the voices, the concerns, and the stories of elderly African Americans, which have often been overlooked in the literature. The following themes emerged from the analysis of data: (1) perception of health as ability to be active, (2) reluctance toward prescription medicine use, (3) lack of trust in doctors, (4) avoidance of bad news, (5) race of doctors, (6) use of home remedies, and (7) importance of God and spirituality on health, illness, and healing.

  4. Self-fitting shape memory polymer foam inducing bone regeneration: A rabbit femoral defect study.

    Science.gov (United States)

    Xie, Ruiqi; Hu, Jinlian; Hoffmann, Oskar; Zhang, Yuanchi; Ng, Frankie; Qin, Tingwu; Guo, Xia

    2018-04-01

    Although tissue engineering has been attracted greatly for healing of critical-sized bone defects, great efforts for improvement are still being made in scaffold design. In particular, bone regeneration would be enhanced if a scaffold precisely matches the contour of bone defects, especially if it could be implanted into the human body conveniently and safely. In this study, polyurethane/hydroxyapatite-based shape memory polymer (SMP) foam was fabricated as a scaffold substrate to facilitate bone regeneration. The minimally invasive delivery and the self-fitting behavior of the SMP foam were systematically evaluated to demonstrate its feasibility in the treatment of bone defects in vivo. Results showed that the SMP foam could be conveniently implanted into bone defects with a compact shape. Subsequently, it self-matched the boundary of bone defects upon shape-recovery activation in vivo. Micro-computed tomography determined that bone ingrowth initiated at the periphery of the SMP foam with a constant decrease towards the inside. Successful vascularization and bone remodeling were also demonstrated by histological analysis. Thus, our results indicate that the SMP foam demonstrated great potential for bone regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Heritability of face shape in twins: a preliminary study using 3D stereophotogrammetry and geometric morphometrics

    Directory of Open Access Journals (Sweden)

    Seth M. Weinberg

    2013-11-01

    Full Text Available Introduction: Previous research suggests that aspects of facial surface morphology are heritable.  Traditionally, heritability studies have used a limited set of linear distances to quantify facial morphology and often employ statistical methods poorly designed to deal with biological shape.  In this preliminary report, we use a combination of 3D photogrammetry and landmark-based morphometrics to explore which aspects of face shape show the strongest evidence of heritability in a sample of twins. Methods: 3D surface images were obtained from 21 twin pairs (10 monozygotic, 11 same-sex dizygotic.  Thirteen 3D landmarks were collected from each facial surface and their coordinates subjected to geometric morphometric analysis.  This involved superimposing the individual landmark configurations and then subjecting the resulting shape coordinates to a principal components analysis.  The resulting PC scores were then used to calculate rough narrow-sense heritability estimates. Results: Three principal components displayed evidence of moderate to high heritability and were associated with variation in the breadth of orbital and nasal structures, upper lip height and projection, and the vertical and forward projection of the root of the nose due to variation in the position of nasion. Conclusions: Aspects of facial shape, primarily related to variation in length and breadth of central midfacial structures, were shown to demonstrate evidence of strong heritability. An improved understanding of which facial features are under strong genetic control is an important step in the identification of specific genes that underlie normal facial variation.

  6. A Study on the Method to Discriminate Between the Internal and External Radioactive Contamination Using Whole Body Counter

    International Nuclear Information System (INIS)

    Kong, T. Y.; Kim, H. G.; Yang, H. Y.; Kang, D. W.; Lim, S. N.; Kim, H. J.; Jin, H. H.; Lee, S. G.; Park, S. C.

    2006-01-01

    Whole Body Counter (WBC) is used to identify and measure the radioactivity in the body of human beings in a nuclear power plants (NPPs). In domestic NPPs, it is prescribed that all workers should take a whole body counting after radiation works if the possibilities of radioactive contamination exist or the radioactivity is detected by a portal monitoring. It is, however, found that the external skin contamination is occasionally estimated as the internal radioactive contamination. In this case, the worker assumed to be detected is recommended to take showers for the decontamination of skin and take a whole body counting again. Although the detected radioactivity is reduced remarkably after several decontaminations, confirmed as the external skin contamination, it is determined finally as an internal exposure if the radioactivity is still detected in the body of worker. The amount of detected radioactivity can be much higher than that of the expected for this mistaken contamination since the radioisotopes attached to skin come to be close to the detectors of WBC. Finally, this makes the misjudgment of the external skin contamination as well as the excessively conservative estimation of radioactive contamination. In this study, several experiments were carried out to discriminate between the internal and external radioactive contamination using the humanoid phantom and WBC. Preliminary experimental results indicated that the use of front and backside counts could be applied to the discrimination of the external skin contamination and the difference of detected radioactivities between front and backside counts was less than about factor 2 for the internal contamination

  7. 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

  8. Discrimination of surface wear on obsidian tools using LSCM and RelA: pilot study results (area-scale analysis of obsidian tool surfaces).

    Science.gov (United States)

    Stemp, W James; Chung, Steven

    2011-01-01

    This pilot study tests the reliability of laser scanning confocal microscopy (LSCM) to quantitatively measure wear on experimental obsidian tools. To our knowledge, this is the first use of confocal microscopy to study wear on stone flakes made from an amorphous silicate like obsidian. Three-dimensional surface roughness or texture area scans on three obsidian flakes used on different contact materials (hide, shell, wood) were documented using the LSCM to determine whether the worn surfaces could be discriminated using area-scale analysis, specifically relative area (RelA). When coupled with the F-test, this scale-sensitive fractal analysis could not only discriminate the used from unused surfaces on individual tools, but was also capable of discriminating the wear histories of tools used on different contact materials. Results indicate that such discriminations occur at different scales. Confidence levels for the discriminations at different scales were established using the F-test (mean square ratios or MSRs). In instances where discrimination of surface roughness or texture was not possible above the established confidence level based on MSRs, photomicrographs and RelA assisted in hypothesizing why this was so. Copyright © 2011 Wiley Periodicals, Inc.

  9. A case study of quark-gluon discrimination at NNLL{sup '} in comparison to parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Jonathan; Waalewijn, Wouter J. [University of Amsterdam, Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics, Amsterdam (Netherlands); Nikhef, Theory Group, Amsterdam (Netherlands); Tackmann, Frank J. [Theory Group, Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-11-15

    Predictions for our ability to distinguish quark and gluon jets vary by more than a factor of two between different parton showers. We study this problem using analytic resummed predictions for the thrust event shape up to NNLL{sup '} using e{sup +}e{sup -} → Z → q anti q and e{sup +}e{sup -} → H → gg as proxies for quark and gluon jets. We account for hadronization effects through a nonperturbative shape function, and include an estimate of both perturbative and hadronization uncertainties. In contrast to previous studies, we find reasonable agreement between our results and predictions from both Pythia and Herwig parton showers. We find that this is due to a noticeable improvement in the description of gluon jets in the newest Herwig 7.1 compared to previous versions. (orig.)

  10. A case study of quark-gluon discrimination at NNLL{sup '} in comparison to parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Jonathan; Waalewijn, Wouter [Institute for Theoretical Physics, Amsterdam (Netherlands); Amsterdam Univ. (Netherlands). Delta Inst. for Theoretical Physics; Nikhef, Amsterdam (Netherlands). Theory Group; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2017-08-15

    Predictions for our ability to distinguish quark and gluon jets vary by more than a factor of two between different parton showers. We study this problem using analytic resummed predictions for the thrust event shape up to NNLL{sup '} using e{sup +}e{sup -}→Z→q anti q and e{sup +}e{sup -}→H→gg as proxies for quark and gluon jets. We account for hadronization effects through a nonperturbative shape function, and include an estimate of both perturbative and hadronization uncertainties. In contrast to previous studies, we find reasonable agreement between our results and predictions from both PYTHIA and HERWIG parton showers. We find that this is due to a noticeable improvement in the description of gluon jets in the newest Herwig 7.1 compared to previous versions.

  11. Exposing Racial Discrimination: Implicit & Explicit Measures–The My Body, My Story Study of 1005 US-Born Black & White Community Health Center Members

    Science.gov (United States)

    Krieger, Nancy; Waterman, Pamela D.; Kosheleva, Anna; Chen, Jarvis T.; Carney, Dana R.; Smith, Kevin W.; Bennett, Gary G.; Williams, David R.; Freeman, Elmer; Russell, Beverley; Thornhill, Gisele; Mikolowsky, Kristin; Rifkin, Rachel; Samuel, Latrice

    2011-01-01

    Background To date, research on racial discrimination and health typically has employed explicit self-report measures, despite their potentially being affected by what people are able and willing to say. We accordingly employed an Implicit Association Test (IAT) for racial discrimination, first developed and used in two recent published studies, and measured associations of the explicit and implicit discrimination measures with each other, socioeconomic and psychosocial variables, and smoking. Methodology/Principal Findings Among the 504 black and 501 white US-born participants, age 35–64, randomly recruited in 2008–2010 from 4 community health centers in Boston, MA, black participants were over 1.5 times more likely (pdiscrimination exposure was also 2.5 to 3.7 times higher (pdiscrimination occurred for the black versus white participants: for “black person vs. white person”: 0.26 vs. 0.13; and for “me vs. them”: 0.24 vs. 0.19. In both groups, only low non-significant correlations existed between the implicit and explicit discrimination measures; social desirability was significantly associated with the explicit but not implicit measures. Although neither the explicit nor implicit discrimination measures were associated with odds of being a current smoker, the excess risk for black participants (controlling for age and gender) rose in models that also controlled for the racial discrimination and psychosocial variables; additional control for socioeconomic position sharply reduced and rendered the association null. Conclusions Implicit and explicit measures of racial discrimination are not equivalent and both warrant use in research on racial discrimination and health, along with data on socioeconomic position and social desirability. PMID:22125618

  12. Structure Sensitivity Study of Waterborne Contaminant Hydrogenation Using Shape- and Size-Controlled Pd Nanoparticles

    KAUST Repository

    Shuai, Danmeng; McCalman, Dorrell C.; Choe, Jong Kwon; Shapley, John R.; Schneider, William F.; Werth, Charles J.

    2013-01-01

    Catalytic reduction with Pd has emerged as a promising technology to remove a suite of contaminants from drinking water, such as oxyanions, disinfection byproducts, and halogenated pollutants, but low activity is a major challenge for application. To address this challenge, we synthesized a set of shape- and size-controlled Pd nanoparticles and evaluated the activity of three probe contaminants (i.e., nitrite, N-nitrosodimethylamine (NDMA), and diatrizoate) as a function of facet type (e.g., (100), (110), (111)), ratios of low- to high-coordination sites, and ratios of surface sites to total Pd (i.e., dispersion). Reduction results for an initial contaminant concentration of 100 μM show that initial turnover frequency (TOF0) for nitrite increases 4.7-fold with increasing percent of (100) surface Pd sites (from 0% to 95.3%), whereas the TOF0 for NDMA and for diatrizoate increases 4.5- and 3.6-fold, respectively, with an increasing percent of terrace surface Pd sites (from 79.8% to 95.3%). Results for an initial nitrite concentration of 2 mM show that TOF0 is the same for all shape- and size-controlled Pd nanoparticles. Trends for TOF0 were supported by results showing that all catalysts but one were stable in shape and size up to 12 days; for the exception, iodide liberation in diatrizoate reduction appeared to be responsible for a shape change of 4 nm octahedral Pd nanoparticles. Density functional theory (DFT) simulations for the free energy change of hydrogen (H2), nitrite, and nitric oxide (NO) adsorption and a two-site model based on the Langmuir-Hinshelwood mechanism suggest that competition of adsorbates for different Pd sites can explain the TOF0 results. Our study shows for the first time that catalytic reduction activity for waterborne contaminant removal varies with the Pd shape and size, and it suggests that Pd catalysts can be tailored for optimal performance to treat a variety of contaminants for drinking water. © 2013 American Chemical Society.

  13. Structure Sensitivity Study of Waterborne Contaminant Hydrogenation Using Shape- and Size-Controlled Pd Nanoparticles

    KAUST Repository

    Shuai, Danmeng

    2013-03-01

    Catalytic reduction with Pd has emerged as a promising technology to remove a suite of contaminants from drinking water, such as oxyanions, disinfection byproducts, and halogenated pollutants, but low activity is a major challenge for application. To address this challenge, we synthesized a set of shape- and size-controlled Pd nanoparticles and evaluated the activity of three probe contaminants (i.e., nitrite, N-nitrosodimethylamine (NDMA), and diatrizoate) as a function of facet type (e.g., (100), (110), (111)), ratios of low- to high-coordination sites, and ratios of surface sites to total Pd (i.e., dispersion). Reduction results for an initial contaminant concentration of 100 μM show that initial turnover frequency (TOF0) for nitrite increases 4.7-fold with increasing percent of (100) surface Pd sites (from 0% to 95.3%), whereas the TOF0 for NDMA and for diatrizoate increases 4.5- and 3.6-fold, respectively, with an increasing percent of terrace surface Pd sites (from 79.8% to 95.3%). Results for an initial nitrite concentration of 2 mM show that TOF0 is the same for all shape- and size-controlled Pd nanoparticles. Trends for TOF0 were supported by results showing that all catalysts but one were stable in shape and size up to 12 days; for the exception, iodide liberation in diatrizoate reduction appeared to be responsible for a shape change of 4 nm octahedral Pd nanoparticles. Density functional theory (DFT) simulations for the free energy change of hydrogen (H2), nitrite, and nitric oxide (NO) adsorption and a two-site model based on the Langmuir-Hinshelwood mechanism suggest that competition of adsorbates for different Pd sites can explain the TOF0 results. Our study shows for the first time that catalytic reduction activity for waterborne contaminant removal varies with the Pd shape and size, and it suggests that Pd catalysts can be tailored for optimal performance to treat a variety of contaminants for drinking water. © 2013 American Chemical Society.

  14. 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).

  15. Segmentation and quantification of materials with energy discriminating computed tomography: A phantom study

    International Nuclear Information System (INIS)

    Le, Huy Q.; Molloi, Sabee

    2011-01-01

    Purpose: To experimentally investigate whether a computed tomography (CT) system based on CdZnTe (CZT) detectors in conjunction with a least-squares parameter estimation technique can be used to decompose four different materials. Methods: The material decomposition process was divided into a segmentation task and a quantification task. A least-squares minimization algorithm was used to decompose materials with five measurements of the energy dependent linear attenuation coefficients. A small field-of-view energy discriminating CT system was built. The CT system consisted of an x-ray tube, a rotational stage, and an array of CZT detectors. The CZT array was composed of 64 pixels, each of which is 0.8x0.8x3 mm. Images were acquired at 80 kVp in fluoroscopic mode at 50 ms per frame. The detector resolved the x-ray spectrum into energy bins of 22-32, 33-39, 40-46, 47-56, and 57-80 keV. Four phantoms were constructed from polymethylmethacrylate (PMMA), polyethylene, polyoxymethylene, hydroxyapatite, and iodine. Three phantoms were composed of three materials with embedded hydroxyapatite (50, 150, 250, and 350 mg/ml) and iodine (4, 8, 12, and 16 mg/ml) contrast elements. One phantom was composed of four materials with embedded hydroxyapatite (150 and 350 mg/ml) and iodine (8 and 16 mg/ml). Calibrations consisted of PMMA phantoms with either hydroxyapatite (100, 200, 300, 400, and 500 mg/ml) or iodine (5, 15, 25, 35, and 45 mg/ml) embedded. Filtered backprojection and a ramp filter were used to reconstruct images from each energy bin. Material segmentation and quantification were performed and compared between different phantoms. Results: All phantoms were decomposed accurately, but some voxels in the base material regions were incorrectly identified. Average quantification errors of hydroxyapatite/iodine were 9.26/7.13%, 7.73/5.58%, and 12.93/8.23% for the three-material PMMA, polyethylene, and polyoxymethylene phantoms, respectively. The average errors for the four

  16. Fighting discrimination.

    Science.gov (United States)

    Wientjens, Wim; Cairns, Douglas

    2012-10-01

    In the fight against discrimination, the IDF launched the first ever International Charter of Rights and Responsibilities of People with Diabetes in 2011: a balance between rights and duties to optimize health and quality of life, to enable as normal a life as possible and to reduce/eliminate the barriers which deny realization of full potential as members of society. It is extremely frustrating to suffer blanket bans and many examples exist, including insurance, driving licenses, getting a job, keeping a job and family affairs. In this article, an example is given of how pilots with insulin treated diabetes are allowed to fly by taking the responsibility of using special blood glucose monitoring protocols. At this time the systems in the countries allowing flying for pilots with insulin treated diabetes are applauded, particularly the USA for private flying, and Canada for commercial flying. Encouraging developments may be underway in the UK for commercial flying and, if this materializes, could be used as an example for other aviation authorities to help adopt similar protocols. However, new restrictions implemented by the new European Aviation Authority take existing privileges away for National Private Pilot Licence holders with insulin treated diabetes in the UK. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Association of perceived ethnic discrimination with general and abdominal obesity in ethnic minority groups: the HELIUS study.

    Science.gov (United States)

    Schmengler, Heiko; Ikram, Umar Z; Snijder, Marieke B; Kunst, Anton E; Agyemang, Charles

    2017-05-01

    Discrimination is associated with obesity, but this may differ according to the type of obesity and ethnic group. This study examines the association of perceived ethnic discrimination (PED) with general and abdominal obesity in 5 ethnic minority groups. We used cross-sectional data from the HELIUS study, collected from 2011 to 2015. The study sample included 2297 Ghanaians, 4110 African Surinamese, 3021 South-Asian Surinamese, 3562 Turks and 3868 Moroccans aged 18-70 years residing in Amsterdam, the Netherlands. Body mass index (BMI) was used as a measure for general obesity, and waist circumference (WC) for abdominal obesity. PED was measured using the Everyday Discrimination Scale. We used linear regression models adjusted for sociodemographics, psychosocial stressors and health behaviours. In additional analysis, we used standardised variables to compare the strength of the associations. In adjusted models, PED was significantly, positively associated with BMI in the South-Asian Surinamese (β coefficient 0.338; 95% CI 0.106 to 0.570), African Surinamese (0.394; 0.171 to 0.618) and Turks (0.269; 0.027 to 0.510). For WC, a similar pattern was seen: positive associations in the South-Asian Surinamese (0.759; 0.166 to 1.353), African Surinamese (0.833; 0.278 to 1.388) and Turks (0.870; 0.299 to 1.440). When stratified by sex, we found positive associations in Surinamese women, Turkish men and Moroccan men. The strength of the associations with BMI and WC was comparable in the groups. Among the Ghanaians, no significant associations were observed. Ethnic and sex variations are observed in the association of PED with both general and abdominal obesity. Further research on psychosocial buffers and underlying biological mechanisms might help in understanding these variations. 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/.

  18. Feasibility study of polyurethane shape-memory polymer actuators for pressure bandage application

    International Nuclear Information System (INIS)

    Ahmad, Manzoor; Luo Jikui; Miraftab, Mohsen

    2012-01-01

    The feasibility of laboratory-synthesized polyurethane-based shape-memory polymer (SMPU) actuators has been investigated for possible application in medical pressure bandages where gradient pressure is required between the ankle and the knee for treatment of leg ulcers. In this study, using heat as the stimulant, SMPU strip actuators have been subjected to gradual and cyclic stresses; their recovery force, reproducibility and reusability have been monitored with respect to changes in temperature and circumference of a model leg, and the stress relaxation at various temperatures has been investigated. The findings suggest that SMPU actuators can be used for the development of the next generation of pressure bandages.

  19. Feasibility study of polyurethane shape-memory polymer actuators for pressure bandage application.

    Science.gov (United States)

    Ahmad, Manzoor; Luo, Jikui; Miraftab, Mohsen

    2012-02-01

    The feasibility of laboratory-synthesized polyurethane-based shape-memory polymer (SMPU) actuators has been investigated for possible application in medical pressure bandages where gradient pressure is required between the ankle and the knee for treatment of leg ulcers. In this study, using heat as the stimulant, SMPU strip actuators have been subjected to gradual and cyclic stresses; their recovery force, reproducibility and reusability have been monitored with respect to changes in temperature and circumference of a model leg, and the stress relaxation at various temperatures has been investigated. The findings suggest that SMPU actuators can be used for the development of the next generation of pressure bandages.

  20. Parameter studies on the effect of pulse shape on the dynamic plastic deformation of a hexagon

    International Nuclear Information System (INIS)

    Youngdahl, C.K.

    1973-10-01

    Results of a parameter study on the dynamic plastic response of a hexagonal subassembly duct subjected to an internal pressure pulse of arbitrary shape are presented. Plastic distortion of the cross section and large-deformation geometric effects that result in redistribution of the internal forces between bending and membrane stresses in the hexagon wall are included in the analytical model. Correlation procedures are established for relating permanent plastic deformation to simple properties of the pressure pulse, for both the small- and large-deformation ranges. Characteristic response times are determined, and the dynamic load factor for large-deformation plastic response is computed

  1. Nuclear shape coexistence and the study of nuclei far from stability

    International Nuclear Information System (INIS)

    Wood, J.L.

    1987-01-01

    The systematic features of shape coexistence are briefly outlined. The most useful spectroscopic fingerprints for identifying shape coexistence far from stability are presented. Directions for future work are discussed

  2. 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…

  3. 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…

  4. 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

  5. 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)

  6. Low-Dose Contrast-Enhanced Breast CT Using Spectral Shaping Filters: An Experimental Study.

    Science.gov (United States)

    Makeev, Andrey; Glick, Stephen J

    2017-12-01

    Iodinated contrast-enhanced X-ray imaging of the breast has been studied with various modalities, including full-field digital mammography (FFDM), digital breast tomosynthesis (DBT), and dedicated breast CT. Contrast imaging with breast CT has a number of advantages over FFDM and DBT, including the lack of breast compression, and generation of fully isotropic 3-D reconstructions. Nonetheless, for breast CT to be considered as a viable tool for routine clinical use, it would be desirable to reduce radiation dose. One approach for dose reduction in breast CT is spectral shaping using X-ray filters. In this paper, two high atomic number filter materials are studied, namely, gadolinium (Gd) and erbium (Er), and compared with Al and Cu filters currently used in breast CT systems. Task-based performance is assessed by imaging a cylindrical poly(methyl methacrylate) phantom with iodine inserts on a benchtop breast CT system that emulates clinical breast CT. To evaluate detectability, a channelized hoteling observer (CHO) is used with sums of Laguerre-Gauss channels. It was observed that spectral shaping using Er and Gd filters substantially increased the dose efficiency (defined as signal-to-noise ratio of the CHO divided by mean glandular dose) as compared with kilovolt peak and filter settings used in commercial and prototype breast CT systems. These experimental phantom study results are encouraging for reducing dose of breast CT, however, further evaluation involving patients is needed.

  7. KNOW-BLADE, task-3.2 report, tip shape study

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, N.N.; Johansen, J.; Conway, S.; Voutsinas, S.; Hansen, M.O.L.; Stuermer, A.

    2005-01-01

    For modern rotor blades with their very large aspect ratio, the blade tip is a very limited part of the overall rotor, and as such of limited importance for the overall aerodynamics of the rotor. Even though they may not be very important for the overall power production, the tip noise can be very important for the acoustics of the rotor [15], and the blade tips can as well be important for the aerodynamic damping properties of the rotor blades [13]. Unfortunately, not many options exists for predicting the aerodynamic behavior of blade tips using computational methods. Experimentally it is dicult to perform detailed measurements in the form of pressure and velocity measurements in natural wind conditions on modern large scale turbines due to the inherent unsteadiness in the natural wind. The present study describes the application of four different Navier-Stokes solvers to tip shape studies, and shows that these codes are well suited to study the flow around different tip shape geometries, and can predict the pressure distributions at the blade tip quite accurately. (au)

  8. 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.

  9. A study on fast digital discrimination of neutron and gamma-ray for improvement neutron emission profile measurement

    International Nuclear Information System (INIS)

    Uchida, Y.; Takada, E.; Fujisaki, A.; Isobe, M.; Ogawa, K.; Shinohara, K.; Tomita, H.; Kawarabayashi, J.; Iguchi, T.

    2014-01-01

    Neutron and γ-ray (n-γ) discrimination with a digital signal processing system has been used to measure the neutron emission profile in magnetic confinement fusion devices. However, a sampling rate must be set low to extend the measurement time because the memory storage is limited. Time jitter decreases a discrimination quality due to a low sampling rate. As described in this paper, a new charge comparison method was developed. Furthermore, automatic n-γ discrimination method was examined using a probabilistic approach. Analysis results were investigated using the figure of merit. Results show that the discrimination quality was improved. Automatic discrimination was applied using the EM algorithm and k-means algorithm

  10. A study on fast digital discrimination of neutron and gamma-ray for improvement neutron emission profile measurement

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Y., E-mail: h1312101@mailg.nc-toyama.ac.jp; Takada, E.; Fujisaki, A. [National Institute of Technology, Toyama College, 13 Hongo-machi, Toyama 939-8630 (Japan); Isobe, M. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); The Graduate University for Advanced Studies (SOKENDAI), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Ogawa, K. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Shinohara, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0913 (Japan); Tomita, H.; Kawarabayashi, J.; Iguchi, T. [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2014-11-15

    Neutron and γ-ray (n-γ) discrimination with a digital signal processing system has been used to measure the neutron emission profile in magnetic confinement fusion devices. However, a sampling rate must be set low to extend the measurement time because the memory storage is limited. Time jitter decreases a discrimination quality due to a low sampling rate. As described in this paper, a new charge comparison method was developed. Furthermore, automatic n-γ discrimination method was examined using a probabilistic approach. Analysis results were investigated using the figure of merit. Results show that the discrimination quality was improved. Automatic discrimination was applied using the EM algorithm and k-means algorithm.

  11. Gender-based discrimination and unprotected receptive anal intercourse among transgender women in Brazil: A mixed methods study.

    Science.gov (United States)

    Magno, Laio; Dourado, Inês; Silva, Luís Augusto V da; Brignol, Sandra; Amorim, Leila; MacCarthy, Sarah

    2018-01-01

    Discrimination related to gender identity may directly influence vulnerability to HIV through increased exposure to unprotected receptive anal intercourse (URAI). Little is known about the relationship between gender-based discrimination (GBD) and URAI with stable partners among transgender women. This mixed-methods research began with a cross-sectional survey conducted between 2014 and 2016 with transgender women in Salvador, the capital city in one of the poorest regions in Brazil. Respondent-driven sampling was used to recruit the study population. GBD was defined through Latent Class Analysis. Additionally, 19 semi-structured interviews with participants were transcribed and analyzed through thematic content analysis. URAI with stable partners was commonly reported (37.3%). GDB was positively associated with URAI among stable partners (OR = 6.47; IC 95%: 1.67-25.02). The analysis of the interviews illustrated how GBD impacted transgender women in diverse ways. Experiences with GBD perpetrated by the family often initiated a trajectory of economic vulnerability that led many to engage in survival sex work. The constant experience with GBD contributed to participants feeling an immense sense of trust with their stable partners, ultimately diminished their desire to use condoms. Further, the high frequency of GBD contributed to poor mental health overall, though some participants said engagement in transgender advocacy efforts provided a vital source of resilience and support. Our mixed-method study capitalizes upon the strengths of diverse data sets to produce a holistic understanding of GBD and URAI with stable partners. Furthermore, by confirming the association between greater GBD and URAI, we have demonstrated how GBD can impact condom negotiation in diverse relationships.

  12. Community-based interventions that work to reduce HIV stigma and discrimination: results of an evaluation study in Thailand.

    Science.gov (United States)

    Jain, Aparna; Nuankaew, Ratana; Mongkholwiboolphol, Nungruthai; Banpabuth, Arunee; Tuvinun, Rachada; Oranop Na Ayuthaya, Pakprim; Richter, Kerry

    2013-11-13

    HIV stigma and discrimination are major issues affecting people living with HIV in their everyday lives. In Thailand, a project was implemented to address HIV stigma and discrimination within communities with four activities: (1) monthly banking days; (2) HIV campaigns; (3) information, education and communication (IEC) materials and (4) "Funfairs." This study evaluates the effect of project interventions on reducing community-level HIV stigma. A repeated cross-sectional design was developed to measure changes in HIV knowledge and HIV-related stigma domains among community members exposed to the project. Two cross-sectional surveys were implemented at baseline (respondent n=560) and endline (respondent n=560). T-tests were employed to assess changes on three stigma domains: fear of HIV infection through daily activity, shame associated with having HIV and blame towards people with HIV. Baseline scales were confirmed at endline, and each scale was regressed on demographic characteristics, HIV knowledge and exposure to intervention activities. No differences were observed in respondent characteristics at baseline and endline. Significant changes were observed in HIV transmission knowledge, fear of HIV infection and shame associated with having HIV from baseline to endline. Respondents exposed to three specific activities (monthly campaign, Funfair and IEC materials) were less likely to exhibit stigma along the dimensions of fear (3.8 points lower on average compared to respondents exposed to none or only one intervention; 95% CI: -7.3 to -0.3) and shame (4.1 points lower; 95% CI: -7.7 to -0.6), net of demographic controls and baseline levels of stigma. Personally knowing someone with HIV was associated with low fear and shame, and females were less likely to possess attitudes of shame compared to males. The multivariate linear models suggest that a combination of three interventions was critical in shifting community-level stigma--monthly campaign, Funfair and IEC

  13. Self-reported racial discrimination, response to unfair treatment, and coronary calcification in asymptomatic adults - the North Texas Healthy Heart study

    Directory of Open Access Journals (Sweden)

    Young Richard

    2010-05-01

    Full Text Available Abstract Background Accruing evidence supports the hypothesis that psychosocial factors are related to cardiovascular disease. However, a limited number of studies have investigated the pathophysiologic pathways through which these associations occur. The purpose of this study was to assess whether experiences of self-reported racial discrimination and reactions to unfair treatment were associated with coronary artery calcification (CAC, an indicator of subclinical coronary heart disease (CHD. Methods This cross-sectional study recruited 571 subjects (45 years and older who were asymptomatic of CHD from Fort Worth, Texas from 2006 to 2008. Subjects completed a questionnaire, a multi-slice computed tomography scan to assess for CAC presence (measured as Agatston score >0, and serum chemistries. Logistic regression was used to estimate odds ratios (ORs and 95% confidence intervals (CIs for the association between self-reported discrimination and CAC. Results were stratified by response to unfair treatment as it was found to significantly modify the relationship between discrimination and CAC. Results Among those who passively responded to unfair treatment, the odds of having CAC present were approximately 3 times higher for those experiencing discrimination (OR, 2.95; 95% CI, 1.19-7.32 after adjusting for age, gender, race/ethnicity, education, body mass index, hyperlipidemia, smoking status, hypertension, diabetes, and first degree relative with heart disease. Conclusions This is the first multi-racial/ethnic study to find racial discrimination associated with CAC, which differs based on how one responds to unfair treatment.

  14. 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...

  15. A Floating Ocean Energy Conversion Device and Numerical Study on Buoy Shape and Performance

    Directory of Open Access Journals (Sweden)

    Ruiyin Song

    2016-05-01

    Full Text Available Wave and current energy can be harnessed in the East China Sea and South China Sea; however, both areas are subject to high frequencies of typhoon events. To improve the safety of the ocean energy conversion device, a Floating Ocean Energy Conversion Device (FOECD with a single mooring system is proposed, which can be towed to avoid severe ocean conditions or for regular maintenance. In this paper, the structure of the FOECD is introduced, and it includes a catamaran platform, an oscillating buoy part, a current turbine blade, hydraulic energy storage and an electrical generation part. The numerical study models the large catamaran platform as a single, large buoy, while the four floating buoys were modeled simply as small buoys. Theoretical models on wave energy power capture and efficiency were established. To improve the suitability of the buoy for use in the FOECD and its power harvesting capability, a numerical simulation of the four buoy geometries was undertaken. The shape profiles examined in this paper are cylindrical, turbinate (V-shaped and U-shaped cone with cylinder, and combined cylinder-hemisphere buoys. Simulation results reveal that the suitability of a turbinate buoy is the best of the four types. Further simulation models were carried out by adjusting the tip radius of the turbinate buoy. Three performance criteria including suitability, power harvesting capability and energy capture efficiency were analyzed. It reveals that the turbinate buoy has almost the same power harvesting capabilities and energy capture efficiency, while its suitability is far better than that of a cylindrical buoy.

  16. Study of shape memory alloy fibers for the development of artificial myocardium.

    Science.gov (United States)

    Hassoulas, Ioannis A; Ladopoulos, Vlassios S; Kalogerakos, Paris-Dimitrios K

    2010-01-01

    Circulatory support devices are employed to treat heart failure. Such a device could be made from shape memory alloy (SMA) fibers. These Ni-Ti fibers contract when electric current flows through them, thus resembling artificial muscles. An artificial myocardium device made from SMA fibers can directly compress the epicardial surface of a failing heart, thus contributing to the pumping action. Unlike modern mechanical circulatory support devices, there is no blood-contacting surface to provoke thromboembolism, hemorrhage, inflammatory response or hemolysis. The experimental setup permitted a detailed study of a sample SMA fiber with great accuracy while the ambient temperature was controlled to resemble that of the human body. The current profile through the fiber was controlled (current shaping, CS) by a microcontroller and a portable computer. Parameters such as strain, contraction and relaxation velocities and the effect of ambient temperature were measured. The contraction and relaxation velocities were measured after applying various effective currents. It was found that the contraction velocity could be manipulated to reach that of the healthy myocardium through CS. On the other hand, the relaxation velocity was independent of the contraction velocity. A cardiac assist device can be made from SMA fibers. More studies need to be conducted in this direction.

  17. 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.

  18. 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.

  19. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  20. Video raster stereography back shape reconstruction: a reliability study for sagittal, frontal, and transversal plane parameters.

    Science.gov (United States)

    Schroeder, J; Reer, R; Braumann, K M

    2015-02-01

    As reliability of raster stereography was proved only for sagittal plane parameters with repeated measures on the same day, the present study was aiming at investigating variability and reliability of back shape reconstruction for all dimensions (sagittal, frontal, transversal) and for different intervals. For a sample of 20 healthy volunteers, intra-individual variability (SEM and CV%) and reliability (ICC ± 95% CI) were proved for sagittal (thoracic kyphosis, lumbar lordosis, pelvis tilt angle, and trunk inclination), frontal (pelvis torsion, pelvis and trunk imbalance, vertebral side deviation, and scoliosis angle), transversal (vertebral rotation), and functional (hyperextension) spine shape reconstruction parameters for different test-retest intervals (on the same day, between-day, between-week) by means of video raster stereography. Reliability was high for the sagittal plane (pelvis tilt, kyphosis and lordosis angle, and trunk inclination: ICC > 0.90), and good to high for lumbar mobility (0.86 < ICC < 0.97). Apart from sagittal plane spinal alignment, there was a lack of certainty for a high reproducibility indicated by wider ICC confidence intervals. So, reliability was fair to high for vertebral side deviation and the scoliosis angle (0.71 < ICC < 0.95), and poor to good for vertebral rotation values as well as for frontal plane upper body and pelvis position parameters (0.65 < ICC < 0.92). Coefficients for the between-day and between-week interval were a little lower than for repeated measures on the same day. Variability (SEM) was less than 1.5° or 1.5 mm, except for trunk inclination. Relative variability (CV) was greater in global trunk position and pelvis parameters (35-98%) than in scoliosis (14-20%) or sagittal sway parameters (4-8 %). Although we found a lower reproducibility for the frontal plane, raster stereography is considered to be a reliable method for the non-invasive, three-dimensional assessment of spinal alignment in normal non

  1. 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.

  2. A study on the shape memory characteristics of Ti-Ni50-x-Pdx alloys

    International Nuclear Information System (INIS)

    Lee, H. W.; Chun, B. S.; Oh, S. J.; Kuk, I.H.

    1991-01-01

    The shape memory characteristics in TiNi alloys are greatly effected by the alloy composition and heat treatment condition. The present work was aimed to investigate the effect of Pd x (x=5,10,15,20) addition on the shape memory chracteristics of TiNi alloys by means of electrical resistance measurement. X-ray diffraction, differential scanning calorimetry and electron dispersive analysis X-ray measurement. The results obtained from this study are as follows; 1. The martensitic transformation start temperature, Ms of Ti-Ni 50-x -Pd x alloys decreased considerably with the increase of Pd content up to 10at%, whereas increased largely with the increase of Pd content in the alloys with Pd content more than 15at%. 2. The Ms temperature of Ti-Ni 50-x -Pd x alloys with cold working was significantly lower than that of the fully annealed alloys because high density dislocation has been introduced by the cold working which suppressed the martensitic transformation. (Author)

  3. Spectrally shaped broadband study of up-conversion in Y2O3:Er3+

    International Nuclear Information System (INIS)

    Lytle, A.L.; Gagnon, E.; Tulchinsky, L.; Krebs, J.K.

    2014-01-01

    We present a novel scheme for studying up-conversion through excited state absorption (ESA) by using a broadband excitation source with spectral shaping capabilities. Up-conversion processes have typically been investigated using a single, narrowband excitation source, when the two steps of the process are coincident in frequency, which is often made possible by broadening mechanisms of the intermediate excited state manifolds. Thus, narrowband sources are limited in the systems they can excite and what material information they can provide. With broadband light, we are able to drive up-conversion with non-coincident frequencies as well. Finally, by windowing the spectrum, we determine the optimal excitation bandwidth for low-concentration (1%) Y 2 O 3 :Er 3+ nanocrystals. - Highlights: • Broadband excitation light is used to drive up-conversion in Y 2 O 3 :Er 3+ . • Broadband light excites all available transitions in the two-photon process. • A spectral shaping technique is used to alter the excitation frequencies present. • The optimal excitation bandwidth is measured by windowing the spectrum. • Broadband excitation reveals information inaccessible by narrowband sources

  4. A Clinical Study on the Shape of Normal Liver by Scintiphoto

    International Nuclear Information System (INIS)

    Chang, Ko Chang; Park, Chong In; Kim, Chong Suhl; Lee, Jin Oh; Lee, Jang Kyu

    1975-01-01

    A knowledge of the wide ranges in shape of liver is important in the interpretation of hepatic scintigraphy as some variants may be easily confused with pathological abnormalities. In this study, the variations in shape in 250 cases of normal liver obtained by scintiphoto were categorized into 9 types by means of the arbitrary standard for classification. 1) Among 250 normal cases, type 5 was 118 (47.2%) with the highest prevalence and type 3 was 2 (0.8%) with the lowest. 2) A higher incidence of obesity was noted in type 1, type 4 and type 8. That of ideal weight was noted in type 2, type 5 type 6 and type 9. 3) A high ratio of cardiac impression in scintiphoto was noted in type 4, type 7 and type 8. That of square left lobe was noted in type 2, type 6 and type 9. Finally that of tailed left lobe was in type 4, type 7 and type 8.

  5. Prenatal maternal stress shapes children's theory of mind: the QF2011 Queensland Flood Study.

    Science.gov (United States)

    Simcock, G; Kildea, S; Elgbeili, G; Laplante, D P; Cobham, V; King, S

    2017-08-01

    Research shows that stress in pregnancy has powerful and enduring effects on many facets of child development, including increases in behavior problems and neurodevelopmental disorders. Theory of mind is an important aspect of child development that is predictive of successful social functioning and is impaired in children with autism. A number of factors related to individual differences in theory of mind have been identified, but whether theory of mind development is shaped by prenatal events has not yet been examined. In this study we utilized a sudden onset flood that occurred in Queensland, Australia in 2011 to examine whether disaster-related prenatal maternal stress predicts child theory of mind and whether sex of the child or timing of the stressor in pregnancy moderates these effects. Higher levels of flood-related maternal subjective stress, but not objective hardship, predicted worse theory of mind at 30 months (n=130). Further, maternal cognitive appraisal of the flood moderated the effects of stress in pregnancy on girls' theory of mind performance but not boys'. These results illuminate how stress in pregnancy can shape child development and the findings are discussed in relation to biological mechanisms in pregnancy and stress theory.

  6. Shape coexistence in the neutron-deficient mercury isotopes studied through Coulomb excitation

    CERN Document Server

    Bree, Nick

    This thesis describes the analysis and results of a series of Coulomb-excitation experiments on even-even neutron-deficient mercury isotopes aimed at obtaining a more detailed description of shape coexistence. Two experimental campaigns have been undertaken in the Summer of 2007 and 2008. Pure beams of 182,184,186,188Hg were produced and accelerated at the REX-ISOLDE radioactive-beam facility, located at CERN (Geneva, Switzerland). The beams were guided to collide with a stable target to induce Coulomb excitation. The scattered particles were registered by a double-sided silicon strip detector, and the emitted gamma rays by the MINIBALL gamma-ray spectrometer. The motivation to study these mercury isotopes, focused around shape coexistence in atomic nuclei, is addressed in chapter 1, as well as an overview of the knowledge in this region of the nuclear chart. A theoretical description of Coulomb excitation is presented in the second chapter, while the third chapter describes the setup employed for the experim...

  7. Experimental study on mechanism and shape characteristics of suspended flexible dam

    Science.gov (United States)

    Wang, Jian-zhong; Fan, Hong-xia; Zhu, Li-jun

    2014-12-01

    Hydraulic structures such as groin, longitudinal dike and seawall are common in water conservancy and water transportation engineering projects at home and abroad, which have long been dominated by solid mass structural form. With brush and stone as building materials, this kind of structure has an obvious engineering effect. However, it not only requires huge capital investments, but also has negative impacts on the ecological environment. The suspended flexible dam is an innovative engineering measure, and few theoretical and experimental researches of this type dam can be found at present. This paper studies the mechanism and shape characteristics of this dam and obtains the dynamic equilibrium equation of flexible dam, the float buoyancy expression, and the condition for transformation among three forms of the underwater shape of the dam. The results are valuable in engineering application and can be used as the reference for the future work due to the distinctive design philosophy, the small negative effects on environment and the consistency for sustainable development.

  8. The J-shape association of ethanol intake with total homocysteine concentrations: the ATTICA study

    Directory of Open Access Journals (Sweden)

    Pitsavos Christos

    2004-10-01

    Full Text Available Abstract Background Epidemiological studies suggest a non-monotonic effect of alcohol consumption on cardiovascular risk, while there is strong evidence concerning the involvement of homocysteine levels on thrombosis. The aim of this work was to evaluate the association between usual ethanol consumption and homocysteine levels, in cardiovascular disease free adults. Methods From May 2001 to December 2002 we randomly enrolled 1514 adult men and 1528 women, without any evidence of cardiovascular disease, stratified by age – gender (census 2001, from the greater area of Athens, Greece. Among the variables ascertained we measured the daily ethanol consumption and plasma homocysteine concentrations. Results Data analysis revealed a J-shape association between ethanol intake (none, 48 gr per day and total homocysteine levels (mean ± standard deviation among males (13 ± 3 vs. 11 ± 3 vs. 14 ± 4 vs. 18 ± 5 vs. 19 ± 3 μmol/L, respectively, p Conclusion We observed a J-shape relationship between homocysteine concentrations and the amount of ethanol usually consumed.

  9. 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

  10. A study of weather types at Athens and Thessaloniki and their relationship to circulation types for the cold-wet period, part II: discriminant analysis

    Science.gov (United States)

    Michailidou, C.; Maheras, P.; Arseni-Papadimititriou, A.; Kolyva-Machera, F.; Anagnostopoulou, C.

    2009-06-01

    A discriminant analysis is applied in order to determine the relationships between circulation types in the middle troposphere and prevailing weather types over two major Greek cities, Athens and Thessaloniki. In order to describe the synoptic conditions, an automatic classification scheme for the Greek region is used. For each circulation type identified (14 in total), several meteorological parameters at the 500 hPa level are calculated such as geopotential heights and their anomalies, temperature and relative vorticity. Weather group-types that reflect the conditions at the surface, were previously defined using a two-step cluster analysis. These types result from a combination of five meteorological parameters—maximum temperature, precipitation amount, relative humidity, wind velocity and sunshine duration. The study period is 43 years long (1958-2000) and is restricted to the cold and wet period of the year, from December until March. For Athens, six weather types are developed, whereas for Thessaloniki five are produced. By means of a stepwise discriminant analysis (DA) model, the most important variables from the 500 hPa level are found and are used to generate the necessary functions that can discriminate weather types over the two stations. The aim of the present study is first to discriminate weather types effectively and to identify the most important discriminating variables, and second, to connect these weather types to elements of the prevailing synoptic pattern, through mathematical functions provided by DA. The results of the evaluation of the aforementioned procedure are considered to be very satisfactory.

  11. Day-to-day discrimination and health among Asian Indians: a population-based study of Gujarati men and women in Metropolitan Detroit.

    Science.gov (United States)

    Yoshihama, Mieko; Bybee, Deborah; Blazevski, Juliane

    2012-10-01

    This study examined the relationship between experiences of day-to-day discrimination and two measures of health among Gujaratis, one of the largest ethnic groups of Asian Indians in the U.S. Data were collected via computer-assisted telephone interviews with a random sample of Gujarati men and women aged 18-64 in Metropolitan Detroit (N = 423). Using structural equation modeling, we tested two gender-moderated models of the relationship between day-to-day discrimination and health, one using the single-item general health status and the other using the 4-item emotional wellbeing measure. For both women and men, controlling for socio-demographic and other relevant characteristics, the experience of day-to-day discrimination was associated with worse emotional wellbeing. However, day-to-day discrimination was associated with the single-item self-rated general health status only for men. This study identified not only gender differences in discrimination-health associations but also the importance of using multiple questions in assessing perceived health status.

  12. Engineering Design Tools for Shape Memory Alloy Actuators: CASMART Collaborative Best Practices and Case Studies

    Science.gov (United States)

    Wheeler, Robert W.; Benafan, Othmane; Gao, Xiujie; Calkins, Frederick T; Ghanbari, Zahra; Hommer, Garrison; Lagoudas, Dimitris; Petersen, Andrew; Pless, Jennifer M.; Stebner, Aaron P.; hide

    2016-01-01

    The primary goal of the Consortium for the Advancement of Shape Memory Alloy Research and Technology (CASMART) is to enable the design of revolutionary applications based on shape memory alloy (SMA) technology. In order to help realize this goal and reduce the development time and required experience for the fabrication of SMA actuation systems, several modeling tools have been developed for common actuator types and are discussed herein along with case studies, which highlight the capabilities and limitations of these tools. Due to their ability to sustain high stresses and recover large deformations, SMAs have many potential applications as reliable, lightweight, solid-state actuators. Their advantage over classical actuators can also be further improved when the actuator geometry is modified to fit the specific application. In this paper, three common actuator designs are studied: wires, which are lightweight, low-profile, and easily implemented; springs, which offer actuation strokes upwards of 200 at reduced mechanical loads; and torque tubes, which can provide large actuation forces in small volumes and develop a repeatable zero-load actuation response (known as the two-way shape memory effect). The modeling frameworks, which have been implemented in the design tools, are developed for each of these frequently used SMA actuator types. In order to demonstrate the versatility and flexibility of the presented design tools, as well as validate their modeling framework, several design challenges were completed. These case studies include the design and development of an active hinge for the deployment of a solar array or foldable space structure, an adaptive solar array deployment and positioning system, a passive air temperature controller for regulation flow temperatures inside of a jet engine, and a redesign of the Corvette active hatch, which allows for pressure equalization of the car interior. For each of the presented case studies, a prototype or proof

  13. The Prototype of Indicators of a Responsive Partner Shapes Information Processing: A False Recognition Study.

    Science.gov (United States)

    Turan, Bulent

    2016-01-01

    When judging whether a relationship partner can be counted on to "be there" when needed, people may draw upon knowledge structures to process relevant information. We examined one such knowledge structure using the prototype methodology: indicators of a partner who is likely to be there when needed. In the first study (N = 91), the structure, content, and reliability of the prototype of indicators were examined. Then, using a false recognition study (N = 77), we demonstrated that once activated, the prototype of indicators of a partner who is likely to be there when needed affects information processing. Thus, the prototype of indicators may shape how people process support-relevant information in everyday life, affecting relationship outcomes. Using this knowledge structure may help a person process relevant information quickly and with cognitive economy. However, it may also lead to biases in judgments in certain situations.

  14. 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.

  15. Perceived discrimination and the risk of schizophrenia in ethnic minorities : a case-control study

    NARCIS (Netherlands)

    Veling, Wim; Hoek, H. W.; Mackenbach, J. P.

    2008-01-01

    BACKGROUND: Previous studies have reported a very high incidence of schizophrenia for immigrant ethnic groups in Western Europe. The explanation of these findings is unknown, but is likely to involve social stress inherent to the migrant condition. A previous study reported that the incidence of

  16. 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.

  17. An experimental study on coolability of a particulate bed with radial stratification or triangular shape

    International Nuclear Information System (INIS)

    Thakre, Sachin; Li, Liangxing; Ma, Weimin

    2014-01-01

    Highlights: • Dryout heat flux of a particulate bed with radial stratification is obtained. • It was found to be dominated by hydrodynamics in the bigger size of particle layer. • Coolability of a particulate bed with triangular shape is investigated. • The coolability is improved in the triangular bed due to lateral ingression of coolant. • Coolability of both beds is enhanced by a downcomer. - Abstract: This paper deals with the results of an experimental study on the coolability of particulate beds with radial stratification and triangular shape, respectively. The study is intended to get an idea on how the coolability is affected by the different features of a debris bed formed in a severe accident of light water reactors. The experiments were performed on the POMECO-HT facility which was constructed to investigate two-phase flow and heat transfer in particulate beds under either top-flooding or bottom-fed condition. A downcomer is designed to enable investigation of the effectiveness of natural circulation driven coolability. Two homogenous beds were also employed in the present study to compare their dryout power densities with those of the radially stratified bed and the triangular bed. The results show that the dryout heat fluxes of the homogeneous beds at top-flooding condition can be predicted by the Reed model. For the radially stratified bed, the dryout heat flux is dominated by two-phase flow in the columns packed with larger particles, and the dryout occurred initially near the boundary between the middle column and a side column. Given the same volume of particles under top-flooding condition, the dryout power density of the triangular bed is about 69% higher than that of the homogenous bed. The coolability of all the beds is enhanced by bottom-fed coolant driven by either forced injection or downcomer-induced natural circulation

  18. An experimental study on coolability of a particulate bed with radial stratification or triangular shape

    Energy Technology Data Exchange (ETDEWEB)

    Thakre, Sachin; Li, Liangxing; Ma, Weimin, E-mail: ma@safety.sci.kth.se

    2014-09-15

    Highlights: • Dryout heat flux of a particulate bed with radial stratification is obtained. • It was found to be dominated by hydrodynamics in the bigger size of particle layer. • Coolability of a particulate bed with triangular shape is investigated. • The coolability is improved in the triangular bed due to lateral ingression of coolant. • Coolability of both beds is enhanced by a downcomer. - Abstract: This paper deals with the results of an experimental study on the coolability of particulate beds with radial stratification and triangular shape, respectively. The study is intended to get an idea on how the coolability is affected by the different features of a debris bed formed in a severe accident of light water reactors. The experiments were performed on the POMECO-HT facility which was constructed to investigate two-phase flow and heat transfer in particulate beds under either top-flooding or bottom-fed condition. A downcomer is designed to enable investigation of the effectiveness of natural circulation driven coolability. Two homogenous beds were also employed in the present study to compare their dryout power densities with those of the radially stratified bed and the triangular bed. The results show that the dryout heat fluxes of the homogeneous beds at top-flooding condition can be predicted by the Reed model. For the radially stratified bed, the dryout heat flux is dominated by two-phase flow in the columns packed with larger particles, and the dryout occurred initially near the boundary between the middle column and a side column. Given the same volume of particles under top-flooding condition, the dryout power density of the triangular bed is about 69% higher than that of the homogenous bed. The coolability of all the beds is enhanced by bottom-fed coolant driven by either forced injection or downcomer-induced natural circulation.

  19. Numerical and experimental study on atmospheric pressure ionization waves propagating through a U-shape channel

    International Nuclear Information System (INIS)

    Yan, Wen; Xia, Yang; Bi, Zhenhua; Song, Ying; Liu, Dongping; Wang, Dezhen; Sosnin, Eduard A; Skakun, Victor S

    2017-01-01

    A 2D computational study of ionization waves propagating in U-shape channels at atmospheric pressure was performed, with emphasis on the effect of voltage polarity and the curvature of the bend. The discharge was ignited by a HV needle electrode inside the channel, and power was applied in the form of a trapezoidal pulse lasting 2 µ s. We have shown that behavior of ionization waves propagating in U-shape channels was quite different with that in straight tubes. For positive polarity of applied voltage, the ionization waves tended to propagate along one side of walls rather than filling the channel. The propagation velocity of ionization waves predicted by the simulation was in good agreement with the experiment results; the velocity was first increasing rapidly in the vicinity of the needle tip and then decreasing with the increment of propagation distance. Then we have studied the influence of voltage polarity on discharge characteristics. For negative polarity, the ionization waves tended to propagate along the opposite side of the wall, while the discharge was more diffusive and volume-filling compared with the positive case. It was found that the propagation velocity for the negative ionization wave was higher than that for the positive one. Meanwhile, the propagation of the negative ionization wave depended less on the pre-ionization level than the positive ionization wave. Finally, the effect of the radius of curvature was studied. Simulations have shown that the propagation speeds were sensitive to the radii of the curvature of the channels for both polarities. Higher radii of curvature tended to have higher speed and longer length of plasma. The simulation results were supported by experimental observations under similar discharge conditions. (paper)

  20. The Impact of Everyday Discrimination and Racial Identity Centrality on African American Medical Student Well-Being: a Report from the Medical Student CHANGE Study.

    Science.gov (United States)

    Perry, Sylvia P; Hardeman, Rachel; Burke, Sara E; Cunningham, Brooke; Burgess, Diana J; van Ryn, Michelle

    2016-09-01

    Positive psychological well-being is an important predictor of and contributor to medical student success. Previous work showed that first-year African American medical students whose self-concept was highly linked to their race (high racial identity centrality) were at greater risk for poor well-being. The current study extends this work by examining (a) whether the psychological impact of racial discrimination on well-being depends on African American medical students' racial identity centrality and (b) whether this process is explained by how accepted students feel in medical school. This study used baseline data from the Medical Student Cognitive Habits and Growth Evaluation (CHANGE) Study, a large national longitudinal cohort study of 4732 medical students at 49 medical schools in the USA (n = 243). Regression analyses were conducted to test whether medical student acceptance mediated an interactive effect of discrimination and racial identity centrality on self-esteem and well-being. Both racial identity centrality and everyday discrimination were associated with negative outcomes for first-year African American medical students. Among participants who experienced higher, but not lower, levels of everyday discrimination, racial identity centrality was associated with negative outcomes. When everyday discrimination was high, but not low, racial identity was negatively related to perceived acceptance in medical school, and this in turn was related to increased negative outcomes. Our results suggest that discrimination may be particularly harmful for African American students who perceive their race to be central to their personal identity. Additionally, our findings speak to the need for institutional change that includes commitment and action towards inclusivity and the elimination of structural racism.

  1. In their own words: reports of stigma and genetic discrimination by people at risk for Huntington disease in the International RESPOND-HD study.

    Science.gov (United States)

    Williams, Janet K; Erwin, Cheryl; Juhl, Andrew R; Mengeling, Michelle; Bombard, Yvonne; Hayden, Michael R; Quaid, Kimberly; Shoulson, Ira; Taylor, Sandra; Paulsen, Jane S

    2010-09-01

    Genetic discrimination may be experienced in the day-to-day lives of people at risk for Huntington disease (HD), encompassing occurrences in the workplace, when seeking insurance, within social relationships, and during other daily encounters. At-risk individuals who have tested either positive or negative for the genetic expansion that causes HD, as well as at-risk persons with a 50% chance for developing the disorder but have not had DNA testing completed the International RESPOND-HD (I-RESPOND-HD) survey. One of the study's purposes was to examine perceptions of genetic stigmatization and discrimination. A total of 412 out of 433 participants provided narrative comments, and 191 provided related codable narrative data. The core theme, Information Control, refers to organizational policies and interpersonal actions. This theme was found in narrative comments describing genetic discrimination perceptions across employment, insurance, social, and other situations. These reports were elaborated with five themes: What They Encountered, What They Felt, What Others Did, What They Did, and What Happened. Although many perceptions were coded as hurtful, this was not true in all instances. Findings document that reports of genetic discrimination are highly individual, and both policy as well as interpersonal factors contribute to the outcome of potentially discriminating events. (c) 2010 Wiley-Liss, Inc.

  2. Spiral versus J-shaped coils for neurovascular embolisation - an in-vitro study

    International Nuclear Information System (INIS)

    Sugiu, K.; Tokunaga, K.; Mandai, S.; Martin, J.B.; Jean, B.; Ruefenacht, D.A.

    2003-01-01

    Our purpose was to compare the characteristics of J-shaped detachable platinum coils with those of spiral coils in in-vitro vascular models. J-shaped coils consist of distal semicircular and proximal straight segments, the latter extending for most of the length of the coil. Spiral coils have a helical shape memory and are thus limited in expansion. In in-vitro silicone vascular models simulating intracranial aneurysms and dural arteriovenous fistulae, we compared J-shaped and spiral coils with regard to ease of delivery, anchoring and folding patterns, and stability in various types of vascular lumen. Delivery and retrieval were comparable. In large and irregular aneurysms and venous sinuses, J-shaped coils could form a more complex basket which conformed to the shape of the vascular cavity. The J-shaped coil was always in contact with the vessel wall. In wide-necked aneurysms, coil protrusion was more frequent with J-shaped coils, while spiral coils tended to stay compact and circular. Arteries were occluded in a shorter segment with spiral coils. J-shaped coils were safe and superior for large and irregular aneurysms or sinuses. Spiral coils were preferable for spherical aneurysms and segmental occlusion of arteries. (orig.)

  3. Shapes of the $^{192,190}$Pb ground states from beta decay studies using the total absorption technique

    CERN Document Server

    Estevez Aguado, M.E.; Agramunt, J.; Rubio, B.; Tain, J.L.; Jordan, D.; Fraile, L.M.; Gelletly, W.; Frank, A.; Csatlos, M.; Csige, L.; Dombradi, Zs.; Krasznahorkay, A.; Nacher, E.; Sarriguren, P.; Borge, M.J.G.; Briz, J.A.; Tengblad, O.; Molina, F.; Moreno, O.; Kowalska, M.; Fedosseev, V.N.; Marsh, B.A.; Fedorov, D.V.; Molkanov, P.L.; Andreyev, A.N.; Seliverstov, M.D.; Burkard, K.; Huller, W.

    2015-01-01

    The beta decay of $^{192,190}$Pb has been studied using the total absorption technique at the ISOLDE(CERN) facility. The beta-decay strength deduced from the measurements, combined with QRPA theoretical calculations, allow us to infer that the ground states of the $^{192,190}$Pb isotopes are spherical. These results represent the first application of the shape determination method using the total absorption technique for heavy nuclei and in a region where there is considerable interest in nuclear shapes and shape effects.

  4. 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

  5. Event-shape-engineering study of charge separation in heavy-ion collisions

    Science.gov (United States)

    Wen, Fufang; Bryon, Jacob; Wen, Liwen; Wang, Gang

    2018-01-01

    Recent measurements of charge-dependent azimuthal correlations in high-energy heavy-ion collisions have indicated charge-separation signals perpendicular to the reaction plane, and have been related to the chiral magnetic effect (CME). However, the correlation signal is contaminated with the background caused by the collective motion (flow) of the collision system, and an effective approach is needed to remove the flow background from the correlation. We present a method study with simplified Monte Carlo simulations and a multi-phase transport model, and develop a scheme to reveal the true CME signal via event-shape engineering with the flow vector of the particles of interest. Supported by a grant (DE-FG02-88ER40424) from U.S. Department of Energy, Office of Nuclear Physics

  6. Study on the Depth, Rate, Shape, and Strength of Pulse with Cardiovascular Simulator

    Directory of Open Access Journals (Sweden)

    Ju-Yeon Lee

    2017-01-01

    Full Text Available Pulse diagnosis is important in oriental medicine. The purpose of this study is explaining the mechanisms of pulse with a cardiovascular simulator. The simulator is comprised of the pulse generating part, the vessel part, and the measurement part. The pulse generating part was composed of motor, slider-crank mechanism, and piston pump. The vessel part, which was composed with the aorta and a radial artery, was fabricated with silicon to implement pulse wave propagation. The pulse parameters, such as the depth, rate, shape, and strength, were simulated. With changing the mean pressure, the floating pulse and the sunken pulse were generated. The change of heart rate generated the slow pulse and the rapid pulse. The control of the superposition time of the reflected wave generated the string-like pulse and the slippery pulse. With changing the pulse pressure, the vacuous pulse and the replete pulse were generated. The generated pulses showed good agreements with the typical pulses.

  7. Experimental Study of Boundary Layer Flow Control Using an Array of Ramp-Shaped Vortex Generators

    Science.gov (United States)

    Hirt, Stefanie M.; Zaman, Khairul B.M.Q.; Bencic, Tomothy J.

    2012-01-01

    The objective of this study was to obtain a database on the flowfield past an array of vortex generators (VGs) in a turbulent boundary layer. All testing was carried out in a low speed wind tunnel with a flow velocity of 29 ft/sec, giving a Reynolds number of 17,500 based on the width of the VG. The flowfield generated by an array of five ramp-shaped vortex generators was examined with hot wire anemometry and smoke flow visualization. The magnitude and extent of the velocity increase near the wall, the penetration of the velocity deficit into the core flow, and the peak streamwise vorticity are examined. Influence of various parameters on the effectiveness of the array is considered on the basis of the ability to pull high momentum fluid into the near wall region.

  8. Size and diluted magnetic properties of diamond shaped graphene quantum dots: Monte Carlo study

    Science.gov (United States)

    Masrour, R.; Jabar, A.

    2018-05-01

    The magnetic properties of diamond shaped graphene quantum dots have been investigated by varying their sizes with the Monte Carlo simulation. The magnetizations and magnetic susceptibilities have been studied with dilutions x (magnetic atom), several sizes L (carbon atom) and exchange interaction J between the magnetic atoms. The all magnetic susceptibilities have been situated at the transitions temperatures of each parameters. The obtained values increase when increases the values of x, L and J. The effect of exchanges interactions and crystal field on the magnetization has been discussed. The magnetic hysteresis cycles for several dilutions x, sizes L, exchange interactions J and temperatures T. The magnetic coercive increases with increasing the exchange interactions and decreases when the temperatures values increasing.

  9. Study on properties of stress relaxation for NiTiNb shape memory alloy

    International Nuclear Information System (INIS)

    Zhou Xuchang; Mo Huaqiang; Zeng Guangting; Shen Baoluo; Huo Yongzhong

    2002-01-01

    Stress relaxation tests at high temperature are performed for NiTiNb shape memory alloy to obtain the properties of stress relaxation. The relaxation curve fitted with the expression, which is deduced based on the relation between the relaxation and the creep. With the aid of experimental data, relaxation characteristic coefficient and remaining stress ratio are obtained, which characterize the relaxation behavior. The results of the study show that stress relaxation would be more evident with the higher temperature and/or greater initial stress. NiTiNb alloy has good relaxation resistance in the temperature range 300-400 degree C and the initial stress range 260-360 MPa. NiTiNb has better properties to resist relaxation than NiTiFe, therefore it is more applicable to work at high temperature

  10. Theoretical study of the fibrous capsule tissue growth around a disk-shaped implant

    KAUST Repository

    Djellouli, Rabia; Mahserejian, Shant; Mokrane, A.; Moussaoui, Mohand; Laleg-Kirati, Taous-Meriem

    2012-01-01

    We analyze the mathematical properties of the fibrous capsule tissue concentration around a disk-shaped implant. We establish stability estimates as well as monotonicity results that illustrate the sensitivity of this growth to the biocompatibility index parameters of the implant. In addition, we prove that the growth of the tissue increases exponentially in time toward an asymptotic regime. We also study the mathematical properties of the solution of the inverse problem consisting in the determination of the values of the biocompatibility index parameters from the knowledge of some fibrous capsule tissue measurements. We prove that this model calibration problem admits a unique solution, and establish a characterization of the index parameters. Furthermore, we demonstrate analytically that such a solution is not continuous with respect to the data, and therefore the considered inverse problem is ill-posed due to the lack of the stability requirement. © 2012 Springer-Verlag.

  11. A Retrospective Study of Association between Peg-shaped Maxillary Lateral Incisors and Dental Anomalies.

    Science.gov (United States)

    Kim, Jae-Hwan; Choi, Nam-Ki; Kim, Seon-Mi

    The purpose of this study was to investigate the prevalence of peg-shaped maxillary lateral incisors and the incidence of associated dental anomalies in children. We investigated the prevalence of peg-laterals and incidence of associated dental anomalies in 3,834 children aged 7-15 who visited the Department of Pediatric Dentistry from January 2010 to December 2015 and underwent panoramic radiographs. The prevalence of peg-laterals was 1.69% in boys, 1.75% in girls, and 1.72% overall. Among children with peg-laterals, the frequencies of associated dental anomalies were as follows: congenitally missing teeth, 31.8%; dens invaginatus, 19.7%; palatally displaced canines, 12.1%; supernumerary teeth, 7.6%; and transposition, 7.6%. As children with peg-laterals have a higher incidence of other dental anomalies, careful consideration is needed when planning diagnosis and treatment.

  12. Theoretical study of the fibrous capsule tissue growth around a disk-shaped implant

    KAUST Repository

    Djellouli, Rabia

    2012-08-19

    We analyze the mathematical properties of the fibrous capsule tissue concentration around a disk-shaped implant. We establish stability estimates as well as monotonicity results that illustrate the sensitivity of this growth to the biocompatibility index parameters of the implant. In addition, we prove that the growth of the tissue increases exponentially in time toward an asymptotic regime. We also study the mathematical properties of the solution of the inverse problem consisting in the determination of the values of the biocompatibility index parameters from the knowledge of some fibrous capsule tissue measurements. We prove that this model calibration problem admits a unique solution, and establish a characterization of the index parameters. Furthermore, we demonstrate analytically that such a solution is not continuous with respect to the data, and therefore the considered inverse problem is ill-posed due to the lack of the stability requirement. © 2012 Springer-Verlag.

  13. A cross-sectional study of associations between casual partner, friend discrimination, social support and anxiety symptoms among Chinese transgender women.

    Science.gov (United States)

    Yang, Xiaoshi; Wang, Lie; Gu, Yuan; Song, Wei; Hao, Chun; Zhou, Jinling; Zhang, Qun; Zhao, Qun

    2016-10-01

    Anxiety symptoms are the prevalent mental disorders for transgender women. However, only a few studies are available pertaining to this problem among Chinese Transgender women. Chinese Transgender women are a vulnerable population which is exposed to discrimination and loss of social support due to their gender identity and transition. This study was conducted to estimate the prevalence and factors associated with anxiety symptoms among Chinese transgender women. A cross-sectional study was performed by convenience sampling. This comprised of 209 Chinese transgender women in Shenyang, China. The Zung Self-Rating Anxiety Scale (SAS) was used to assess anxiety symptoms for these transgender women. Hierarchical multiple regression analysis was performed to explore the associated factors of SAS. The prevalence of anxiety symptoms in Chinese transgender women was found to be 34.5%. Regression analyses indicated that SAS was associated with casual partnership, friend discrimination and social support in the final model. Sexual partnership and discrimination contributed the most to the model, R-square, accounting for 19.2% and 15.5% of the total variance respectively. Chinese transgender women showed considerably high level of anxiety symptoms. It was also found that they were exposed to significant transition challenges, such as high risk sexual partnership, excessive discrimination and a reduction in social support. Furthermore, anxiety symptoms was best predicted by the absence or presence of a casual partner, friend discrimination and social support rather than the disclosure of their gender identity, knowledge of HIV prevention and health service. Improvement of social support, reduction of friend discrimination and determination of the characteristics of risky sexual partnerships especially for the casual partner can help to attenuate anxiety symptoms and increase mental well-being for transgender women. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. 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

  15. 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

  16. The use of metabolic balance studies in the objective discrimination between intestinal insufficiency and intestinal failure

    DEFF Research Database (Denmark)

    Prahm, August P; Brandt, Christopher F; Askov-Hansen, Carsten

    2017-01-01

    Background: In research settings that use metabolic balance studies (MBSs) of stable adult patients with short bowel syndrome, intestinal failure (IF) and dependence on parenteral support (PS) have been defined objectively as energy absorption metabolic rate (BMR), wet......, to objectivize the cause of nutritional dyshomeostasis (oral failure, malabsorption, or both), and to quantify the effects of treatment....

  17. Discrimination between low dietary zinc and endotoxin exposure : a model study on weaning rats

    NARCIS (Netherlands)

    Wouwe, van J.P.; Veldhuizen, M.; Hamer, van den C.J.A.; de Goeij, J.J.M.

    1990-01-01

    To establish a parameter for zinc status that is independent of the occurrence of infection, we studied the effects of low dietary zinc and endotoxin in weaning rats 21 d after 65Zn intubation. We monitored aspects of zinc status (tissue zinc content, 65Zn distribution, and specific 65Zn activity in

  18. An experimental study of the correlates and consequences of perceiving oneself to be the target of gender discrimination.

    Science.gov (United States)

    Brown, Christia Spears; Bigler, Rebecca S; Chu, Hui

    2010-10-01

    An experimental methodology was used to test hypotheses concerning the effects of contextual, cognitive-developmental, and individual difference factors on children's views of whether they have been the target of gender discrimination and the possible consequent effect of such views on two forms of state self-esteem: performance and social acceptance. Children (N=108, 5-11 years of age) completed theory of mind and gender attitude measures and a drawing task. Next, children received feedback that was designed to appear either gender biased (discrimination condition) or nonbiased (control condition). Children's attributions for the feedback and state self-esteem were assessed. As expected, children reported having been the target of gender discrimination more often in the discrimination condition than in the control condition. Older and more cognitively advanced children made fewer attributions to discrimination than their peers. Perceptions of discrimination were associated with higher performance state self-esteem and, among egalitarian children, lower social state self-esteem. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Experimental Study for Effects of the Stud shape of the Core Catcher System

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyusang; Son, Hong Hyun; Jeong, Uiju; Seo, Gwang Hyeok; Shin, Doyoung; Jeun, Gyoodong; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2015-05-15

    analysis, it was found that installation of studs affects the streamline by partially blocking the channel. In addition, it was observed that stagnant flow exists at the back of the studs. Such disturbances were expected to differ with the shape of the studs. Thus various stud shapes of rectangular, cylinder, and ellipse were investigated. With this preliminary CFD study, flow boiling experiments were designed and conducted to investigate the effects of the different stud shape on the critical heat flux (CHF). The occurrence of the CHF is anticipated at the back side of the stud due to the possible existence of the hot spot driven by the accumulation of the vapors. Final objective is, therefore, to confirm the effect of the core catcher stud on the performance of boiling heat transfer and to assure that the designed core catcher system may work as intended. In this study, CFD simulations for the different stud shapes of the core catcher system were carried out using ANSYS FLUENNT. With this preliminary CFD study, flow boiling experiments were designed. Final objective is to confirm the effect of the core catcher stud on the performance of boiling heat transfer and to assure that the designed core catcher system may work.

  20. 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

  1. Predictions of On-Line Banks' Fraudulent: A Study on Discriminant Analysis.

    OpenAIRE

    Gabriel Joseph Mukungu; Gwangyong Gim

    2014-01-01

    The information and communication technology (ICT) is growing fast in the community along with some risks. The on-line banks' fraudulent are increasing dramatically resulting in the loss of money and retardate the growth on economic development. Some law enforcers like Tanzanian police yet use the traditional prevention technologies to investigate these on-line banks' fraudulent cases mainly known as cyber crimes. For the purpose of this study, 150 data were collected as cyber...

  2. 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).

  3. Design reuse in product shape modeling : A study of freeform feature reuse by signal processing techniques

    NARCIS (Netherlands)

    Wang, C.

    2005-01-01

    Lack of facilities in supporting design reuse is a serious problem in product shape modeling, especially in computer-aided design systems. This becomes a bottleneck of fast shape conceptualization and creation in consumer product design, which consequently prohibits creativity and innovation. In the

  4. A longitudinal study of perceptual grouping by proximity, luminance and shape in infants at two, four and six months

    OpenAIRE

    Farran, E. K.; Brown, J. H.; Cole, V. L.; Houston-Price, C.; Karmiloff-Smith, A.

    2008-01-01

    Grouping by luminance and shape similarity has previously been demonstrated in neonates and at 4 months, respectively. By contrast, grouping by proximity has hitherto not been investigated in infancy. This is also the first study to chart the developmental emergence of perceptual grouping longitudinally. Sixty-one infants were presented with a matrix of local stimuli grouped horizontally or vertically by luminance, shape or proximity at 2, 4, and 6 months. Infants were exposed to each set of ...

  5. 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.

  6. Comparative Study Between Support Vector Machines And Neural Networks For Lithological Discrimination Using Hyper spectral Data

    International Nuclear Information System (INIS)

    Naguib, A.M.; Abd Elwahab, M.S.; Farag, M.A.; Yahia, M.A.; Ramadan, H.H.

    2009-01-01

    Remote sensing hyper spectral data has many applications especially in the field of , earth science. Utilization of this technology has shown a rapid increase in many areas of economic and scientific significance. Hyper spectral sensors capture the detailed spectral signatures that uniquely characterize a great number of diverse surface materials. Classification, clustering, and visualization of these very high dimensional signatures need untraditional methods. Different approaches for spectral image interpretation have been studied using Artificial Neural Networks (ANNs) and Support Vector Machines (SVM) to meet the challenge of high dimensionality. The study used SVMs for geological mapping of hyper spectral imagery at Abu Zenima area, western Sinai, Egypt, the hyper spectral data has been captured in 2003 by Hyperion instrument on the United States Geological survey (USGS) Earth Observing 1 (EO-I) satellite. Precisely the study compares between the use of SVMs and a neural network built on the concept of SVMs, this network uses the Kernel-Adatron algorithm with the Gaussian kernel for the process of training. The SVMs also uses the Gaussian kernel with different bandwidths to enhance the performance of the interpretation process; the results are compared in details. The Neural Network was trained with four data sets, the first consists of 11310 samples, gives recognition rate of 84%, the second has 22620 samples, recognition rate was 91.5%; the third has 33930 samples, recognition rate was 94.6%; finally the fourth has 45240 samples, recognition rate of 99.2%. The previous results fall in comparison with the results of SVMs which use two algorithms for training the first is the one against one algorithm which gave a recognition rate of 84% for the first data set, a recognition rate of 76.9% for the second data set, a recognition rate of 95.2% for the third one and 98.5% for the fourth one. and the other is one against many algorithms which gave a recognition

  7. Shaping the future of dental education: Caries as a case-study.

    Science.gov (United States)

    Pitts, N B; Mazevet, M E; Mayne, C

    2018-03-01

    This study reports on the full-day workshop "The Shape of The Future of Dental Education for Dental Caries-and how we get there" held immediately prior to the May 2017 ADEE/ADEA/King's College London meeting "Shaping the Future of Dental Education." A standardised, evidence-led Core Curriculum in Cariology (CCC) was developed jointly and systematically by ORCA and ADEE, starting in 2010. At the same time, the ICDAS Foundation was developing a comprehensive caries management system, ICCMS™. The workshop reported on what has been achieved on a global basis by many building on these initiatives. The CCC has been, or is currently being, localised in a number of places around the world and has, in some countries, been successfully implemented. There are also other areas which are struggling more with the logistics of introducing it. The workshop presented geographical perspectives and experiences on implementing the CCC from Colombia, the United States and Europe, as well as professional perspectives from hygienists, students and policymakers. The workshop then considered the future of the CCC and the roles of Interprofessional Education, Technology, Global Networking and Assessment in a Global Context in 4 breakout groups. Having had reports back and plenary discussion, it was concluded that the caries world has made good progress towards a "futuristic" curriculum with parallel development of a comprehensive, preventive and tooth-preserving caries management system-ICCMS™. The implementation challenge is now to share even more effectively in order to have these developments more widely accepted and adopted worldwide. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. A Study on the Effects of Position Change on the Liver Shape on Radioisotope Scan

    International Nuclear Information System (INIS)

    Hong, Kee Suk; Choi, Du Hyok; Yang, Young Tae; Koh, Chang Soon

    1982-01-01

    For this study, the authors obtained and examined anterior views of the liver and spleen in two different positions, upright and supine, of 39 normal subjects and 20 patients with hepatic pathology by means of 99m Tc-colloid and gamma camera. This examination confirms the following findings. In general, it is shown, left lobe of the liver in upright position becomes longer in height than in supine position, while the distance between lateral margin of the liver and that of spleen becomes father in with in supine position than in upright position. The upper margin of liver moves more downward in upright position than in supine. It is noticeable that as for 5 cases with severe chronic liver disease, there is minimal alteration of the liver shape between in two positions. The comparison of the both positions for the better liver scan shows the following findings. Prominent caudate and/or left lobe are marked in the upright position in 16 cases out of the total 59, while none is found in the supine. The false cold area in lower part of the liver disappears in 7 cases in the upright position, while only one shows the disappearance of the false cold area in the supine. Left liver margin due to close contact of spleen is blurred in 3 cases in the upright position. In total 23 cases out of 59 support that the upright position is better for the liver scan, while only 4 cases support the supine position is better. These findings support two assumptions. One is that upright view can be expected more improved resolution than supine view for liver scan. Second is that minimal change of the liver shape in both views indicate the serious abnormality in the liver.

  9. A study of the validity and reliability of the Brazilian version of the Body Shape Questionnaire (BSQ among adolescents Estudo de validade e confiabilidade da versão brasileira do Body Shape Questionnaire (BSQ para adolescentes

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Conti

    2009-09-01

    Full Text Available OBJECTIVES: to produce evidence of the validity and reliability of the Body Shape Questionnaire (BSQ - a tool for measuring an individual's attitude towards his or her body image. METHODS: the study covered 386 young people of both sexes aged between 10 and 18 from a private school and used self-applied questionnaires and anthropometric evaluation. It evaluated the internal consistency, the discriminant validity for differences from the means, according to nutritional status (underweight, eutrophic, overweight and obese, the concurrent validity by way of Spearman's correlation coefficient between the scale and the Body Mass Index (BMI, the waist-hip circumference ratio (WHR and the waist circumference (WC. Reliability was tested using Wilcoxon's Test, the intraclass correlation coefficient and the Bland-Altman figures. RESULTS: the BSQ displayed good internal consistency (±=0.96 and was capable of discriminating among the total population, boys and girls, according to nutritional status (pOBJETIVOS: verificar evidência de validade e confiabilidade do Body Shape Questionnaire (BSQ - instrumento que mensura o aspecto atitudinal da imagem corporal. MÉTODOS: PArticiparam 386 jovens, de ambos os sexos, na faixa etária de 10-18 anos de uma escola particular de ensino, por meio de questionários auto-aplicáveis e avaliação antropométrica. Avaliou-se a consistência interna, a validade discriminante pelas diferenças das médias, segundo estado nutricional (baixo peso, eutrófico, sobrepeso e obesidade, a validade concorrente por meio do coeficiente de correlação de Spearman entre a escala e o Índice de Massa Corporal (IMC, a razão circunferência quadril (RCQ e a circunferência da cintura (CC. Para confiabilidade, utilizou-se o teste de Wilcoxon, o coeficiente de correlação intraclasse e as Figuras de Bland-Altman. RESULTADOS: o BSQ apresentou boa consistência interna (±=0,96 e foi capaz de discriminar população total, meninos e

  10. Identification of facial shape by applying golden ratio to the facial measurements: an interracial study in malaysian population.

    Science.gov (United States)

    Packiriswamy, Vasanthakumar; Kumar, Pramod; Rao, Mohandas

    2012-12-01

    The "golden ratio" is considered as a universal facial aesthetical standard. Researcher's opinion that deviation from golden ratio can result in development of facial abnormalities. This study was designed to study the facial morphology and to identify individuals with normal, short, and long face. We studied 300 Malaysian nationality subjects aged 18-28 years of Chinese, Indian, and Malay extraction. The parameters measured were physiognomical facial height and width of face, and physiognomical facial index was calculated. Face shape was classified based on golden ratio. Independent t test was done to test the difference between sexes and among the races. The mean values of the measurements and index showed significant sexual and interracial differences. Out of 300 subjects, the face shape was normal in 60 subjects, short in 224 subjects, and long in 16 subjects. As anticipated, the measurements showed variations according to gender and race. Only 60 subjects had a regular face shape, and remaining 240 subjects had irregular face shape (short and long). Since the short and long shape individuals may be at risk of developing various disorders, the knowledge of facial shapes in the given population is important for early diagnostic and treatment procedures.

  11. A Study on Visibility Estimation of Web-Safe Colors using Paired Comparison and Discriminant Analysis

    Science.gov (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web safe colors. The research of web page visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., paired comparison. Eighteen chromatic and 3 achromatic web-safe colors were employed for visual stimuli. Twenty-eight subjects ranging from ages 21 to 75 were recruited, and all were with normal color sensation. They looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparison technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  12. The Hue of Shapes

    Science.gov (United States)

    Albertazzi, Liliana; Da Pos, Osvaldo; Canal, Luisa; Micciolo, Rocco; Malfatti, Michela; Vescovi, Massimo

    2013-01-01

    This article presents an experimental study on the naturally biased association between shape and color. For each basic geometric shape studied, participants were asked to indicate the color perceived as most closely related to it, choosing from the Natural Color System Hue Circle. Results show that the choices of color for each shape were not…

  13. Automatic online adaptive radiation therapy techniques for targets with significant shape change: a feasibility study

    International Nuclear Information System (INIS)

    Court, Laurence E; Tishler, Roy B; Petit, Joshua; Cormack, Robert; Chin Lee

    2006-01-01

    This work looks at the feasibility of an online adaptive radiation therapy concept that would detect the daily position and shape of the patient, and would then correct the daily treatment to account for any changes compared with planning position. In particular, it looks at the possibility of developing algorithms to correct for large complicated shape change. For co-planar beams, the dose in an axial plane is approximately associated with the positions of a single multi-leaf collimator (MLC) pair. We start with a primary plan, and automatically generate several secondary plans with gantry angles offset by regular increments. MLC sequences for each plan are calculated keeping monitor units (MUs) and number of segments constant for a given beam (fluences are different). Bulk registration (3D) of planning and daily CT images gives global shifts. Slice-by-slice (2D) registration gives local shifts and rotations about the longitudinal axis for each axial slice. The daily MLC sequence is then created for each axial slice/MLC leaf pair combination, by taking the MLC positions from the pre-calculated plan with the nearest rotation, and shifting using a beam's-eye-view calculation to account for local linear shifts. A planning study was carried out using two head and neck region MR images of a healthy volunteer which were contoured to simulate a base-of-tongue treatment: one with the head straight (used to simulate the planning image) and the other with the head tilted to the left (the daily image). Head and neck treatment was chosen to evaluate this technique because of its challenging nature, with varying internal and external contours, and multiple degrees of freedom. Shape change was significant: on a slice-by-slice basis, local rotations in the daily image varied from 2 to 31 deg, and local shifts ranged from -0.2 to 0.5 cm and -0.4 to 0.0 cm in right-left and posterior-anterior directions, respectively. The adapted treatment gave reasonable target coverage (100%, 90

  14. A study of process parameters on workpiece anisotropy in the laser engineered net shaping (LENSTM) process

    Science.gov (United States)

    Chandra, Shubham; Rao, Balkrishna C.

    2017-06-01

    The process of laser engineered net shaping (LENSTM) is an additive manufacturing technique that employs the coaxial flow of metallic powders with a high-power laser to form a melt pool and the subsequent deposition of the specimen on a substrate. Although research done over the past decade on the LENSTM processing of alloys of steel, titanium, nickel and other metallic materials typically reports superior mechanical properties in as-deposited specimens, when compared to the bulk material, there is anisotropy in the mechanical properties of the melt deposit. The current study involves the development of a numerical model of the LENSTM process, using the principles of computational fluid dynamics (CFD), and the subsequent prediction of the volume fraction of equiaxed grains to predict process parameters required for the deposition of workpieces with isotropy in their properties. The numerical simulation is carried out on ANSYS-Fluent, whose data on thermal gradient are used to determine the volume fraction of the equiaxed grains present in the deposited specimen. This study has been validated against earlier efforts on the experimental studies of LENSTM for alloys of nickel. Besides being applicable to the wider family of metals and alloys, the results of this study will also facilitate effective process design to improve both product quality and productivity.

  15. Ultrasonic Characterization of Cast Austenitic Stainless Steel Microstructure: Discrimination between Equiaxed- and Columnar-Grain Material – An Interim Study

    Energy Technology Data Exchange (ETDEWEB)

    Ramuhalli, Pradeep; Good, Morris S.; Diaz, Aaron A.; Anderson, Michael T.; Watson, Bruce E.; Peters, Timothy J.; Dixit, Mukul; Bond, Leonard J.

    2009-10-27

    Ultrasonic nondestructive evaluation (NDE) and inspection of cast austenitic stainless steel (CASS) components used in the nuclear power industry is neither as effective nor reliable as is needed due to detrimental effects upon the interrogating ultrasonic beam and interference from ultrasonic backscatter. The root cause is the coarse-grain microstructure inherent to this class of materials. Some ultrasonic techniques perform better for particular microstructural classifications and this has led to the hypothesis that an ultrasonic inspection can be optimized for a particular microstructural class, if a technique exists to reliably classify the microstructure for feedback to the inspection. This document summarizes scoping experiments of in-situ ultrasonic methods for classification and/or characterization of the material microstructures in CASS components from the outside surface of a pipe. The focus of this study was to evaluate ultrasonic methods and provide an interim report that documents results and technical progress. An initial set of experiments were performed to test the hypothesis that in-service characterization of cast austenitic stainless steel (CASS) is feasible, and that, if reliably performed, such data would provide real-time feedback to optimize in-service inspections in the field. With this objective in mind, measurements for the experiment were restricted to techniques that should be robust if carried forward to eventual field implementation. Two parameters were investigated for their ability to discriminate between different microstructures in CASS components. The first parameter was a time-of-flight ratio of a normal incidence shear wave to that of a normal incidence longitudinal wave (TOFRSL). The ratio removed dependency on component thickness which may not be accurately reported in the field. The second parameter was longitudinal wave attenuation. The selected CASS specimens provided five equiaxed-grain material samples and five columnar

  16. "Human immunodeficiency virus serostatus disclosure-Rate, reactions, and discrimination": A cross-sectional study at a rural tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Umesh S Joge

    2013-01-01

    Full Text Available Background: From the moment scientists identified Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS, social responses of fear, denial, stigma, and discrimination have accompanied the epidemic. Aims: To assess the rate of disclosure of HIV serostatus, reactions by the HIV/AIDS patients and their spouse, and discrimination faced by the patients. Methods: The present cross-sectional study was conducted at Antiretroviral Therapy (ART center of a rural tertiary care hospital, situated in Marathawada region of Maharashtra state from November 2008 to October 2010. Totally, 801 HIV-positive patients coming to ART center for treatment were included after ensuring confidentiality and taking informed consent. A preformed questionnaire was used to enquire about reaction after diagnosis, disclosure, and discrimination faced by the patients. The data analyzed using descriptive statistics and Chi-square test. Results: The most common immediate reaction by the HIV patients after getting diagnosed as seropositive was fear (593, 74.03% followed by depression (385, 48.06% and suicidal thoughts (98, 12.25%. Out of 801 patients, 769 (96% had spouse and of these maximum number of patients (653, 84.92% had disclosed HIV status to their spouses. Most common immediate reaction by spouse after disclosure was crime (324, 42.13% followed by horror (294, 38.23% and anger (237, 36.29%. Maximum number of patients were discriminated by friends (120, 71.01% followed by discrimination at workplace (49, 67.12%, by neighbors (32, 56.14%, and by relatives (53, 43.80%. Conclusion: Male positives were granted greater acceptance, care, and support by their spouses. More percentage of females discriminated by neighbors, relatives, and friends and at workplace which might be due to factors like customs, morals, and taboos.

  17. "Human Immunodeficiency Virus serostatus disclosure-Rate, reactions, and discrimination": a cross-sectional study at a rural tertiary care hospital.

    Science.gov (United States)

    Joge, Umesh S; Deo, Deepali S; Choudhari, Sonali G; Malkar, Vilas R; Ughade, Harshada M

    2013-01-01

    From the moment scientists identified Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS), social responses of fear, denial, stigma, and discrimination have accompanied the epidemic. To assess the rate of disclosure of HIV serostatus, reactions by the HIV/AIDS patients and their spouse, and discrimination faced by the patients. The present cross-sectional study was conducted at Antiretroviral Therapy (ART) center of a rural tertiary care hospital, situated in Marathawada region of Maharashtra state from November 2008 to October 2010. Totally, 801 HIV-positive patients coming to ART center for treatment were included after ensuring confidentiality and taking informed consent. A preformed questionnaire was used to enquire about reaction after diagnosis, disclosure, and discrimination faced by the patients. The data analyzed using descriptive statistics and Chi-square test. The most common immediate reaction by the HIV patients after getting diagnosed as seropositive was fear (593, 74.03%) followed by depression (385, 48.06%) and suicidal thoughts (98, 12.25%). Out of 801 patients, 769 (96%) had spouse and of these maximum number of patients (653, 84.92%) had disclosed HIV status to their spouses. Most common immediate reaction by spouse after disclosure was crime (324, 42.13%) followed by horror (294, 38.23%) and anger (237, 36.29%). Maximum number of patients were discriminated by friends (120, 71.01%) followed by discrimination at workplace (49, 67.12%), by neighbors (32, 56.14%), and by relatives (53, 43.80%). Male positives were granted greater acceptance, care, and support by their spouses. More percentage of females discriminated by neighbors, relatives, and friends and at workplace which might be due to factors like customs, morals, and taboos.

  18. 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

  19. [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.

  20. Differences in two-point discrimination and sensory threshold in the blind between braille and text reading: a pilot study.

    Science.gov (United States)

    Noh, Ji-Woong; Park, Byoung-Sun; Kim, Mee-Young; Lee, Lim-Kyu; Yang, Seung-Min; Lee, Won-Deok; Shin, Yong-Sub; Kang, Ji-Hye; Kim, Ju-Hyun; Lee, Jeong-Uk; Kwak, Taek-Yong; Lee, Tae-Hyun; Kim, Ju-Young; Kim, Junghwan

    2015-06-01

    [Purpose] This study investigated two-point discrimination (TPD) and the electrical sensory threshold of the blind to define the effect of using Braille on the tactile and electrical senses. [Subjects and Methods] Twenty-eight blind participants were divided equally into a text-reading and a Braille-reading group. We measured tactile sensory and electrical thresholds using the TPD method and a transcutaneous electrical nerve stimulator. [Results] The left palm TPD values were significantly different between the groups. The values of the electrical sensory threshold in the left hand, the electrical pain threshold in the left hand, and the electrical pain threshold in the right hand were significantly lower in the Braille group than in the text group. [Conclusion] These findings make it difficult to explain the difference in tactility between groups, excluding both palms. However, our data show that using Braille can enhance development of the sensory median nerve in the blind, particularly in terms of the electrical sensory and pain thresholds.

  1. DISCRIMINATING BETWEEN TARIFF BILL-BASED THEORIES OF THE STOCK MARKET CRASH OF 1929 USING EVENT STUDY DATA

    Directory of Open Access Journals (Sweden)

    Bernard C. Beaudreau

    2014-07-01

    Full Text Available Jude Wanniski (1978 argued that the Smoot-Hawley Tariff Bill was a key factor in the Stock Market Crash of October 1929 and the Great Depression. The specter of higher tariffs and lower foreign trade, he argued, depressed share prices, leading ultimately to the Stock Market Crash. Bernard Beaudreau (1996, 2005, on the other hand, made the reverse argument, namely that the specter of higher tariffs from November 1928 to October 1929 fueled the Stock Market Boom as investors anticipated higher revenues and profits from the anticipated increase in sales and revenues. The Stock Market Crash, he argued, came on the heels of the defeat of the Thomas Recommittal Plan which foretold of lower, not higher as Wanniski contended, tariffs on manufactures. Using Event Study data from January 14, 1929 to October 29, 1929, this paper attempts to discriminate between these two hypotheses. The results show that “good” tariff bill news as reported in the New York Times contributed to stock price appreciation, and vice-versa, supporting the latter theory.

  2. Experiences of Transgender-Related Discrimination and Implications for Health: Results From the Virginia Transgender Health Initiative Study

    Science.gov (United States)

    Reisner, Sari L.; Honnold, Julie A.; Xavier, Jessica

    2013-01-01

    Objectives. We examined relationships between social determinants of health and experiences of transgender-related discrimination reported by transgender people in Virginia. Methods. In 2005 through 2006, 387 self-identified transgender people completed a statewide health needs assessment; 350 who completed eligibility questions were included in this examination of factors associated with experiences of discrimination in health care, employment, or housing. We fit multivariate logistic regression models using generalized estimating equations to adjust for survey modality (online vs paper). Results. Of participants, 41% (n = 143) reported experiences of transgender-related discrimination. Factors associated with transgender-related discrimination were geographic context, gender (female-to male spectrum vs male-to-female spectrum), low socioeconomic status, being a racial/ethnic minority, not having health insurance, gender transition indicators (younger age at first transgender awareness), health care needed but unable to be obtained (hormone therapy and mental health services), history of violence (sexual and physical), substance use health behaviors (tobacco and alcohol), and interpersonal factors (family support and community connectedness). Conclusions. Findings suggest that transgender Virginians experience widespread discrimination in health care, employment, and housing. Multilevel interventions are needed for transgender populations, including legal protections and training for health care providers. PMID:23153142

  3. Studies on 13C isotope discrimination for identifying tree provenances efficient in water use under water deficit conditions in Kenya

    International Nuclear Information System (INIS)

    Nyamai, D.O.; Juma, P.O.

    1996-01-01

    Screening for drought resistance traits was conducted in a semi-arid site in Machakos using 11 provenances of Acacia tortilis, 6 provenances of Prosopis juliflora and 4 provenances of Casuarina equisetifolia. Tolerance to drought was assessed by the 13 C isotope discrimination (Δ) technique as well as by determining the waster use efficiency (WUE). Measurements of dry matter and early growth performance were also taken as indicators of drought resistance. The results showed significant differences in the 13 C Isotope discrimination, water use efficiency and dry matter yields by the different provenances tested. Generally, the results indicated that there were significant linear negative relationships between 13 C discrimination with water use efficiency as well as dry matter yield. The results further showed highly significant positive relationship between dry matter yield and water use efficiency. Acacia tortilis provenances from middle East and neighbouring North Eastern Africa region appear to possess the greatest abilities for drought resistance in comparison with those from sub-saharan Africa as indicated by their 13 C Isotope discrimination levels, dry matter yield and water use efficiency. However, Acacia provenance from Israel had the highest drought resistance trail. Prosopis provenance from Costa Rica and Casuarina from Dakar region in Senegal also emerged as the best provenances in terms of drought tolerance as shown by the 13 C isotope discrimination and dry matter traits. (author). 8 refs, 4 figs, 3 tabs

  4. Experiences of transgender-related discrimination and implications for health: results from the Virginia Transgender Health Initiative Study.

    Science.gov (United States)

    Bradford, Judith; Reisner, Sari L; Honnold, Julie A; Xavier, Jessica

    2013-10-01

    We examined relationships between social determinants of health and experiences of transgender-related discrimination reported by transgender people in Virginia. In 2005 through 2006, 387 self-identified transgender people completed a statewide health needs assessment; 350 who completed eligibility questions were included in this examination of factors associated with experiences of discrimination in health care, employment, or housing. We fit multivariate logistic regression models using generalized estimating equations to adjust for survey modality (online vs paper). Of participants, 41% (n = 143) reported experiences of transgender-related discrimination. Factors associated with transgender-related discrimination were geographic context, gender (female-to male spectrum vs male-to-female spectrum), low socioeconomic status, being a racial/ethnic minority, not having health insurance, gender transition indicators (younger age at first transgender awareness), health care needed but unable to be obtained (hormone therapy and mental health services), history of violence (sexual and physical), substance use health behaviors (tobacco and alcohol), and interpersonal factors (family support and community connectedness). Findings suggest that transgender Virginians experience widespread discrimination in health care, employment, and housing. Multilevel interventions are needed for transgender populations, including legal protections and training for health care providers.

  5. Study of the peak shape in alpha spectra measured by liquid scintillation

    CERN Document Server

    Vera-Tome, F; Martin-Sanchez, A

    2002-01-01

    Liquid-scintillation counting allows the measurement of alpha and beta activities jointly or only of the alpha-emitting nuclides in a sample. Although the resolution of the alpha spectra is poorer than that attained with semiconductor detectors, it is still an attractive alternative. We describe here attempts to fit a peak shape to experimental liquid-scintillation alpha spectra and discuss the parameters affecting this shape, such as the PSA (pulse-shape analyser) level, vial type, shaking the sample, etc. Spectral analysis has been applied for complex alpha spectra.

  6. [Perceived discrimination at work for being an immigrant: a study on self-perceived mental health status among immigrants in Italy].

    Science.gov (United States)

    Di Napoli, Anteo; Gatta, Rosaria; Rossi, Alessandra; Perez, Monica; Costanzo, Gianfranco; Mirisola, Concetta; Petrelli, Alessio

    2017-01-01

    exposure to discrimination is widely understood as a social determinant of psychophysical health and a contributing factor to health inequities among social groups. Few studies exist, particularly in Italy, about the effects of discrimination among immigrants at workplace. to analyse the association between perceived discrimination at work for being an immigrant and mental health status among immigrants in Italy. a sub-sample of 12,408 immigrants residing in Italy was analysed. data came from the survey "Social conditions and integration of foreign citizens in Italy", carried out in 2011-2012 by the Italian National Institute of Statistics (Istat). Self-perceived mental health status was measured through mental component summary (MCS) of SF-12 questionnaire, assuming as worse health status MCS score distribution ≤1st quartile. In order to evaluate the probability of poor health status, a multivariate log-binomial model was performed assuming: discrimination at work for being an immigrant as determinant variable; age, gender, educational level, employment status, area of origin, residence in Italy, length of stay in Italy, self-perceived loneliness and satisfaction about life as potential confounding variables. among immigrants, 15.8% referred discrimination at his/her workplace in Italy for being an immigrant. Higher probability of poor mental health status was observed for immigrants who referred discrimination at workplace (Prevalence Rate Ratio - PRR: 1.16) who arrived in Italy since at least 5 years (PRR: 1.14), for not employed subjects (PRR: 1.31), and for people from the Americas (PRR: 1.14). Lower probability of poor mental health status was found in immigrants from Western- Central Asia (PRR: 0.83) and Eastern-Pacific Asia (PRR: 0.79). Compared to immigrants residing in North-Eastern Italy, higher probability of worse mental health status was observed in people who resided in Northern-Western (PRR: 1.30), Central (PRR: 1.26), and Southern (PRR: 1

  7. Broadband Discrimination Studies

    Science.gov (United States)

    1976-03-01

    Oroville. This low seismicity continued through initial loading of nearby Oroville Dam in 1967-68 and until the first foreshock on June 28, 1975...Twenty-one foreshocks (ML > 1.6), the largest of magnitude 4.7, preceded the magnitude 5.7 main shock of 01 August. All foreshocks and aftershocks of ML...preceded by foreshocks beginning on June 28, 1975, the largest of which had ML = 3.5 (Table 1); the sequence appeared to have died out (only five events

  8. Shape change in the atlas with congenital midline non-union of its posterior arch: a morphometric geometric study.

    Science.gov (United States)

    Ríos, Luis; Palancar, Carlos; Pastor, Francisco; Llidó, Susana; Sanchís-Gimeno, Juan Alberto; Bastir, Markus

    2017-10-01

    The congenital midline non-union of the posterior arch of the atlas is a developmental variant present at a frequency ranging from 0.7% to 3.9%. Most of the reported cases correspond to incidental findings during routine medical examination. In cases of posterior non-union, hypertrophy of the anterior arch and cortical bone thickening of the posterior arches have been observed and interpreted as adaptive responses of the atlas to increased mechanical stress. We sought to determine if the congenital non-union of the posterior arch results in a change in the shape of the atlas. This study is an analysis of the first cervical vertebrae from osteological collections through morphometric geometric techniques. A total of 21 vertebrae were scanned with a high-resolution three-dimensional scanner (Artec Space Spider, Artec Group, Luxembourg). To capture vertebral shape, 19 landmarks and 100 semilandmarks were placed on the vertebrae. Procrustes superimposition was applied to obtain size and shape data (MorphoJ 1.02; Klingenberg, 2011), which were analyzed through principal component analysis (PCA) and mean shape comparisons. The PCA resulted in two components explaining 22.32% and 18.8% of the total shape variance. The graphic plotting of both components indicates a clear shape difference between the control atlas and the atlas with posterior non-union. This observation was supported by statistically significant differences in mean shape comparisons between both types of vertebra (patlas is associated with significant changes in the shape of the vertebra. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Design and Experimental Study of an L Shape Piezoelectric Energy Harvester

    Directory of Open Access Journals (Sweden)

    In-Ho Kim

    2017-01-01

    Full Text Available Piezoelectric energy harvesters of cantilevered beam type are studied in various fields due to simplicity. In general, these systems obtain electrical energy from mechanical strain by bending of cantilevered beam. However, conventional systems have disadvantages that they have low efficiency in frequency regions other than resonance frequency. To overcome the limitations, various energy harvesters to apply performance enhancement strategies are proposed and investigated. In this paper, a frequency-changeable L shape energy harvester which is form connected cantilever beam and rigid arm is proposed and investigated. The conventional piezoelectric energy harvester exhibits the principal frequency in the simple bending mode whereas the proposed system features the twisting mode resulting in a higher output voltage than the conventional system. The proposed energy harvester is simplified to a two-degree-of-freedom model and its dynamics are described. How the length of a rigid bar affects its natural frequencies is also studied. To evaluate the performance of the system, experiments by using a vertical shaker and numerical simulation are carried out. As a result, it is shown that the natural frequency for a twisting mode decreases as the arm length increased, and the higher output voltage is generated comparing with those of the conventional energy harvester.

  10. Experimentally Studied Influence of the Bullet Head Shape on Dispersion Characteristics at Subsonic Airspeeds

    Directory of Open Access Journals (Sweden)

    S. N. Ilukhin

    2015-01-01

    Full Text Available The article presents description and results of experiments on a ballistic track and subsonic wind tunnel. The subject of study is important an issue such as the assessment of the influence of the bullet head shape on the accuracy of shooting parameters at subsonic muzzle velocity. The article points to the features of examined precision of guided and unguided aircraft, refers to the main disturbing factors. In addition, it outlines the most well known ways to improve the flight precision of unguided munitions. The article presents the geometric parameters of bullets and their scale models used in the experiments. It describes the experimental facilities and the