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Sample records for significant negative linear

  1. Unimode metamaterials exhibiting negative linear compressibility and negative thermal expansion

    International Nuclear Information System (INIS)

    Dudek, Krzysztof K; Attard, Daphne; Caruana-Gauci, Roberto; Grima, Joseph N; Wojciechowski, Krzysztof W

    2016-01-01

    Unimode metamaterials made from rotating rigid triangles are analysed mathematically for their mechanical and thermal expansion properties. It is shown that these unimode systems exhibit positive Poisson’s ratios irrespective of size, shape and angle of aperture, with the Poisson’s ratio exhibiting giant values for certain conformations. When the Poisson’s ratio in one loading direction is larger than +1, the systems were found to exhibit the anomalous property of negative linear compressibility along this direction, that is, the systems expand in this direction when hydrostatically compressed. Also discussed are the thermal expansion properties of these systems under the assumption that the units exhibit increased rotational agitation once subjected to an increase in temperature. The effect of the geometric parameters on the aforementioned thermo-mechanical properties of the system, are discussed, with the aim of identifying negative behaviour. (paper)

  2. The strategic significance of negative externalities.

    Science.gov (United States)

    2012-12-01

    Negative externalities have competitive relevance in a market when they have selective impacts as, for : example, when a product in use imposes greater costs on consumers of rival products than on other people. : Because managers have discretion ...

  3. Alternative theories of the non-linear negative mass instability

    International Nuclear Information System (INIS)

    Channell, P.J.

    1974-01-01

    A theory non-linear negative mass instability is extended to include resistance. The basic assumption is explained physically and an alternative theory is offered. The two theories are compared computationally. 7 refs., 8 figs

  4. Linear negative magnetoresistance in two-dimensional Lorentz gases

    Science.gov (United States)

    Schluck, J.; Hund, M.; Heckenthaler, T.; Heinzel, T.; Siboni, N. H.; Horbach, J.; Pierz, K.; Schumacher, H. W.; Kazazis, D.; Gennser, U.; Mailly, D.

    2018-03-01

    Two-dimensional Lorentz gases formed by obstacles in the shape of circles, squares, and retroreflectors are reported to show a pronounced linear negative magnetoresistance at small magnetic fields. For circular obstacles at low number densities, our results agree with the predictions of a model based on classical retroreflection. In extension to the existing theoretical models, we find that the normalized magnetoresistance slope depends on the obstacle shape and increases as the number density of the obstacles is increased. The peaks are furthermore suppressed by in-plane magnetic fields as well as by elevated temperatures. These results suggest that classical retroreflection can form a significant contribution to the magnetoresistivity of two-dimensional Lorentz gases, while contributions from weak localization cannot be excluded, in particular for large obstacle densities.

  5. Clinical Significance of CK19 Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    Nobuyuki Arima

    2012-12-01

    Full Text Available Analysis of sentinel lymph nodes (SLNs by means of One-Step Nucleic Acid Amplification (OSNA is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19 which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis.

  6. Clinical Significance of CK19 Negative Breast Cancer

    International Nuclear Information System (INIS)

    Fujisue, Mamiko; Nishimura, Reiki; Okumura, Yasuhiro; Tashima, Rumiko; Nishiyama, Yasuyuki; Osako, Tomofumi; Toyozumi, Yasuo; Arima, Nobuyuki

    2012-01-01

    Analysis of sentinel lymph nodes (SLNs) by means of One-Step Nucleic Acid Amplification (OSNA) is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19) which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis

  7. Clinical Significance of CK19 Negative Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Fujisue, Mamiko, E-mail: nishimura.reiki@cityhosp-kumamoto.jp; Nishimura, Reiki; Okumura, Yasuhiro [Department of Breast and Endocrine Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Tashima, Rumiko [Department of Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Nishiyama, Yasuyuki; Osako, Tomofumi [Department of Breast and Endocrine Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Toyozumi, Yasuo; Arima, Nobuyuki [Department of Pathology, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan)

    2012-12-21

    Analysis of sentinel lymph nodes (SLNs) by means of One-Step Nucleic Acid Amplification (OSNA) is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19) which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis.

  8. Negative base encoding in optical linear algebra processors

    Science.gov (United States)

    Perlee, C.; Casasent, D.

    1986-01-01

    In the digital multiplication by analog convolution algorithm, the bits of two encoded numbers are convolved to form the product of the two numbers in mixed binary representation; this output can be easily converted to binary. Attention is presently given to negative base encoding, treating base -2 initially, and then showing that the negative base system can be readily extended to any radix. In general, negative base encoding in optical linear algebra processors represents a more efficient technique than either sign magnitude or 2's complement encoding, when the additions of digitally encoded products are performed in parallel.

  9. High-brightness negative-hydrogen linear accelerator

    International Nuclear Information System (INIS)

    Wadlinger, E.A.; Farrell, J.A.; Dogliani, H.O.

    1982-01-01

    We have designed a linear accelerator to accelerate negative hydrogen ions to 50 MeV with an instantaneous output current of 100 mA and a normalized rms emittance in both transverse planes of 0.02 π cm mrad. The design and results obtained to date with a 2-MeV prototype are presented

  10. The clinicopathologic characteristics and prognostic significance of triple-negativity in node-negative breast cancer

    International Nuclear Information System (INIS)

    Rhee, Jiyoung; Kim, Tae-You; Han, Sae-Won; Oh, Do-Youn; Kim, Jee Hyun; Im, Seock-Ah; Han, Wonshik; Ae Park, In; Noh, Dong-Young; Bang, Yung-Jue

    2008-01-01

    Triple-negative (TN) breast cancer, which is defined as being negative for the estrogen receptor (ER), the progesterone receptor (PR), and the human epidermal growth factor receptor 2 (HER-2), represents a subset of breast cancer with different biologic behaviour. We investigated the clinicopathologic characteristics and prognostic indicators of lymph node-negative TN breast cancer. Medical records were reviewed from patients with node-negative breast cancer who underwent curative surgery at Seoul National University Hospital between Jan. 2000 and Jun. 2003. Clinicopathologic variables and clinical outcomes were evaluated. Among 683 patients included, 136 had TN breast cancer and 529 had non-TN breast cancer. TN breast cancer correlated with younger age (< 35 y, p = 0.003), and higher histologic and nuclear grade (p < 0.001). It also correlated with a molecular profile associated with biological aggressiveness: negative for bcl-2 expression (p < 0.001), positive for the epidermal growth factor receptor (p = 0.003), and a high level of p53 (p < 0.001) and Ki67 expression (p < 0.00). The relapse rates during the follow-up period (median, 56.8 months) were 14.7% for TN breast cancer and 6.6% for non-TN breast cancer (p = 0.004). Relapse free survival (RFS) was significantly shorter among patients with TN breast cancer compared with those with non-TN breast cancer (4-year RFS rate 85.5% vs. 94.2%, respectively; p = 0.001). On multivariate analysis, young age, close resection margin, and triple-negativity were independent predictors of shorter RFS. TN breast cancer had higher relapse rate and more aggressive clinicopathologic characteristics than non-TN in node-negative breast cancer. Thus, TN breast cancer should be integrated into the risk factor analysis for node-negative breast cancer

  11. Evaluating significance in linear mixed-effects models in R.

    Science.gov (United States)

    Luke, Steven G

    2017-08-01

    Mixed-effects models are being used ever more frequently in the analysis of experimental data. However, in the lme4 package in R the standards for evaluating significance of fixed effects in these models (i.e., obtaining p-values) are somewhat vague. There are good reasons for this, but as researchers who are using these models are required in many cases to report p-values, some method for evaluating the significance of the model output is needed. This paper reports the results of simulations showing that the two most common methods for evaluating significance, using likelihood ratio tests and applying the z distribution to the Wald t values from the model output (t-as-z), are somewhat anti-conservative, especially for smaller sample sizes. Other methods for evaluating significance, including parametric bootstrapping and the Kenward-Roger and Satterthwaite approximations for degrees of freedom, were also evaluated. The results of these simulations suggest that Type 1 error rates are closest to .05 when models are fitted using REML and p-values are derived using the Kenward-Roger or Satterthwaite approximations, as these approximations both produced acceptable Type 1 error rates even for smaller samples.

  12. Uniaxial Negative Thermal Expansion, Negative Linear Compressibility, and Negative Poisson's Ratio Induced by Specific Topology in Zn[Au(CN)2]2.

    Science.gov (United States)

    Wang, Lei; Luo, Hubin; Deng, Shenghua; Sun, Ying; Wang, Cong

    2017-12-18

    The well-known idea of "structure determines properties" can be understood profoundly in the case of hexagonal zinc dicyanometalate. Using density functional theory (DFT) calculations, we show the uniaxial negative thermal expansion (NTE) and negative linear compressibility (NLC) properties of Zn[Au(CN) 2 ] 2 . The temperature dependence of phonon frequencies within the quasi-harmonic approximation (QHA) is investigated. The abnormal phonon hardening (frequency increase on heating) is detected in the ranges of 0-225, 320-345, and 410-430 cm -1 , which can be indicative of the unusual physical properties of Zn[Au(CN) 2 ] 2 . Due to the significance of low-energy phonon frequencies in Zn[Au(CN) 2 ] 2 , in this work, the corresponding vibrational mode of the lowest-frequency optical phonon at the zone center is analyzed. The specific topology of a springlike framework that will produce the effects of a compressed spring on heating and an extended spring under hydrostatic pressure is identified and leads to the coexistence of uniaxial-NTE and NLC behaviors in Zn[Au(CN) 2 ] 2 . The distinguishing phonon group velocity along the a axis and c axis facilitates different responses for both the axes under temperature and hydrostatic pressure field. Through an analysis and visualization of the spatial dependence of elastic tensors, it is found that a negative Poisson's ratio (NPR) is presented in all projection planes due to the specific topology.

  13. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Cai, Weizhao; Katrusiak, Andrzej

    2014-07-04

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices.

  14. Wigner weight functions and Weyl symbols of non-negative definite linear operators

    NARCIS (Netherlands)

    Janssen, A.J.E.M.

    1989-01-01

    In this paper we present several necessary and, for radially symmetric functions, necessary and sufficient conditions for a function of two variables to be a Wigner weight function (Weyl symbol of a non-negative definite linear operator of L2(R)). These necessary conditions are in terms of spread

  15. Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA and lengthen linear DNA

    International Nuclear Information System (INIS)

    Verebová, Valéria; Adamcik, Jozef; Danko, Patrik; Podhradský, Dušan; Miškovský, Pavol; Staničová, Jana

    2014-01-01

    Highlights: • Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA. • Anthraquinones quinizarin and danthron lengthen linear DNA. • Anthraquinones quinizarin and danthron possess middle binding affinity to DNA. • Anthraquinones quinizarin and danthron interact with DNA by intercalating mode. - Abstract: The intercalating drugs possess a planar aromatic chromophore unit by which they insert between DNA bases causing the distortion of classical B-DNA form. The planar tricyclic structure of anthraquinones belongs to the group of chromophore units and enables anthraquinones to bind to DNA by intercalating mode. The interactions of simple derivatives of anthraquinone, quinizarin (1,4-dihydroxyanthraquinone) and danthron (1,8-dihydroxyanthraquinone), with negatively supercoiled and linear DNA were investigated using a combination of the electrophoretic methods, fluorescence spectrophotometry and single molecule technique an atomic force microscopy. The detection of the topological change of negatively supercoiled plasmid DNA, unwinding of negatively supercoiled DNA, corresponding to appearance of DNA topoisomers with the low superhelicity and an increase of the contour length of linear DNA in the presence of quinizarin and danthron indicate the binding of both anthraquinones to DNA by intercalating mode

  16. Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA and lengthen linear DNA

    Energy Technology Data Exchange (ETDEWEB)

    Verebová, Valéria [Institute of Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice (Slovakia); Adamcik, Jozef [Food and Soft Materials Science, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 9, CH-8092 Zürich (Switzerland); Danko, Patrik; Podhradský, Dušan [Department of Biochemistry, Institute of Chemistry, Faculty of Sciences, P.J. Šafárik University, Moyzesova 11, 041 54 Košice (Slovakia); Miškovský, Pavol [Department of Biophysics, Faculty of Sciences, P.J. Šafárik University, Jesenná 5, 041 54 Košice (Slovakia); Center for Interdisciplinary Biosciences, Faculty of Sciences, P.J. Šafárik University, Jesenná 5, 041 54 Košice (Slovakia); Staničová, Jana, E-mail: jana.stanicova@uvlf.sk [Institute of Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice (Slovakia)

    2014-01-31

    Highlights: • Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA. • Anthraquinones quinizarin and danthron lengthen linear DNA. • Anthraquinones quinizarin and danthron possess middle binding affinity to DNA. • Anthraquinones quinizarin and danthron interact with DNA by intercalating mode. - Abstract: The intercalating drugs possess a planar aromatic chromophore unit by which they insert between DNA bases causing the distortion of classical B-DNA form. The planar tricyclic structure of anthraquinones belongs to the group of chromophore units and enables anthraquinones to bind to DNA by intercalating mode. The interactions of simple derivatives of anthraquinone, quinizarin (1,4-dihydroxyanthraquinone) and danthron (1,8-dihydroxyanthraquinone), with negatively supercoiled and linear DNA were investigated using a combination of the electrophoretic methods, fluorescence spectrophotometry and single molecule technique an atomic force microscopy. The detection of the topological change of negatively supercoiled plasmid DNA, unwinding of negatively supercoiled DNA, corresponding to appearance of DNA topoisomers with the low superhelicity and an increase of the contour length of linear DNA in the presence of quinizarin and danthron indicate the binding of both anthraquinones to DNA by intercalating mode.

  17. Significance tests for the wavelet cross spectrum and wavelet linear coherence

    Directory of Open Access Journals (Sweden)

    Z. Ge

    2008-12-01

    Full Text Available This work attempts to develop significance tests for the wavelet cross spectrum and the wavelet linear coherence as a follow-up study on Ge (2007. Conventional approaches that are used by Torrence and Compo (1998 based on stationary background noise time series were used here in estimating the sampling distributions of the wavelet cross spectrum and the wavelet linear coherence. The sampling distributions are then used for establishing significance levels for these two wavelet-based quantities. In addition to these two wavelet quantities, properties of the phase angle of the wavelet cross spectrum of, or the phase difference between, two Gaussian white noise series are discussed. It is found that the tangent of the principal part of the phase angle approximately has a standard Cauchy distribution and the phase angle is uniformly distributed, which makes it impossible to establish significance levels for the phase angle. The simulated signals clearly show that, when there is no linear relation between the two analysed signals, the phase angle disperses into the entire range of [−π,π] with fairly high probabilities for values close to ±π to occur. Conversely, when linear relations are present, the phase angle of the wavelet cross spectrum settles around an associated value with considerably reduced fluctuations. When two signals are linearly coupled, their wavelet linear coherence will attain values close to one. The significance test of the wavelet linear coherence can therefore be used to complement the inspection of the phase angle of the wavelet cross spectrum. The developed significance tests are also applied to actual data sets, simultaneously recorded wind speed and wave elevation series measured from a NOAA buoy on Lake Michigan. Significance levels of the wavelet cross spectrum and the wavelet linear coherence between the winds and the waves reasonably separated meaningful peaks from those generated by randomness in the data set. As

  18. Large Negative Linear Compressibility in InH(BDC)₂ from Framework Hinging.

    Science.gov (United States)

    Zeng, Qingxin; Wang, Kai; Zou, Bo

    2017-11-08

    Materials with negative linear compressibility (NLC) counterintuitively expand along one specific direction coupled to the volume reduction when compressed uniformly. NLC with a large value is desired for compression and materials science. However, NLC is generally smaller than -20 TPa -1 . High-pressure X-ray diffraction experiments reveal that the β-quartz-like InH(BDC) 2 generates an extreme NLC (-62.4 TPa -1 ) by framework hinging. InH(BDC) 2 is much safer and lower-cost than Au + /Ag + and CN - -containing materials that dominated the fields of large NLC. This work reconfirms that a negative thermal expansion flexible framework could likely exhibit large NLC. Moreover, a large NLC could be anticipated to arise from β-quartz-like or related frameworks composed of rigid linear ligands and flexible framework angles.

  19. New stable multiply charged negative atomic ions in linearly polarized superintense laser fields

    International Nuclear Information System (INIS)

    Wei Qi; Kais, Sabre; Moiseyev, Nimrod

    2006-01-01

    Singly charged negative atomic ions exist in the gas phase and are of fundamental importance in atomic and molecular physics. However, theoretical calculations and experimental results clearly exclude the existence of any stable doubly-negatively-charged atomic ion in the gas phase, only one electron can be added to a free atom in the gas phase. In this report, using the high-frequency Floquet theory, we predict that in a linear superintense laser field one can stabilize multiply charged negative atomic ions in the gas phase. We present self-consistent field calculations for the linear superintense laser fields needed to bind extra one and two electrons to form He - , He 2- , and Li 2- , with detachment energies dependent on the laser intensity and maximal values of 1.2, 0.12, and 0.13 eV, respectively. The fields and frequencies needed for binding extra electrons are within experimental reach. This method of stabilization is general and can be used to predict stability of larger multiply charged negative atomic ions

  20. Subcellular localization for Gram positive and Gram negative bacterial proteins using linear interpolation smoothing model.

    Science.gov (United States)

    Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2015-12-07

    Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. NBLDA: negative binomial linear discriminant analysis for RNA-Seq data.

    Science.gov (United States)

    Dong, Kai; Zhao, Hongyu; Tong, Tiejun; Wan, Xiang

    2016-09-13

    RNA-sequencing (RNA-Seq) has become a powerful technology to characterize gene expression profiles because it is more accurate and comprehensive than microarrays. Although statistical methods that have been developed for microarray data can be applied to RNA-Seq data, they are not ideal due to the discrete nature of RNA-Seq data. The Poisson distribution and negative binomial distribution are commonly used to model count data. Recently, Witten (Annals Appl Stat 5:2493-2518, 2011) proposed a Poisson linear discriminant analysis for RNA-Seq data. The Poisson assumption may not be as appropriate as the negative binomial distribution when biological replicates are available and in the presence of overdispersion (i.e., when the variance is larger than or equal to the mean). However, it is more complicated to model negative binomial variables because they involve a dispersion parameter that needs to be estimated. In this paper, we propose a negative binomial linear discriminant analysis for RNA-Seq data. By Bayes' rule, we construct the classifier by fitting a negative binomial model, and propose some plug-in rules to estimate the unknown parameters in the classifier. The relationship between the negative binomial classifier and the Poisson classifier is explored, with a numerical investigation of the impact of dispersion on the discriminant score. Simulation results show the superiority of our proposed method. We also analyze two real RNA-Seq data sets to demonstrate the advantages of our method in real-world applications. We have developed a new classifier using the negative binomial model for RNA-seq data classification. Our simulation results show that our proposed classifier has a better performance than existing works. The proposed classifier can serve as an effective tool for classifying RNA-seq data. Based on the comparison results, we have provided some guidelines for scientists to decide which method should be used in the discriminant analysis of RNA-Seq data

  2. Negative linear compressibility and massive anisotropic thermal expansion in methanol monohydrate.

    Science.gov (United States)

    Fortes, A Dominic; Suard, Emmanuelle; Knight, Kevin S

    2011-02-11

    The vast majority of materials shrink in all directions when hydrostatically compressed; exceptions include certain metallic or polymer foam structures, which may exhibit negative linear compressibility (NLC) (that is, they expand in one or more directions under hydrostatic compression). Materials that exhibit this property at the molecular level--crystalline solids with intrinsic NLC--are extremely uncommon. With the use of neutron powder diffraction, we have discovered and characterized both NLC and extremely anisotropic thermal expansion, including negative thermal expansion (NTE) along the NLC axis, in a simple molecular crystal (the deuterated 1:1 compound of methanol and water). Apically linked rhombuses, which are formed by the bridging of hydroxyl-water chains with methyl groups, extend along the axis of NLC/NTE and lead to the observed behavior.

  3. Androgen Receptor Expression in Early Triple-Negative Breast Cancer: Clinical Significance and Prognostic Associations

    Directory of Open Access Journals (Sweden)

    Mirco Pistelli

    2014-06-01

    Full Text Available Background: Triple-negative breast cancers (TNBC are characterized by aggressive tumour biology resulting in a poor prognosis. Androgen receptor (AR is one of newly emerging biomarker in TNBC. In recent years, ARs have been demonstrated to play an important role in the genesis and in the development of breast cancer, although their prognostic role is still debated. In the present study, we explored the correlation of AR expression with clinical, pathological and molecular features and its impact on prognosis in early TNBC. Patients and Methods: ARs were considered positive in case of tumors with >10% nuclear-stained. Survival distribution was estimated by the Kaplan Meier method. The univariate and multivariate analyses were performed. The difference among variables were calculated by chi-square test. Results: 81 TNBC patients diagnosed between January 2006 and December 2011 were included in the analysis. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER-2, Ki-67, ALDH1, e-cadherin and AR. Of the 81 TNBC samples, 18.8% showed positive immunostaining for AR, 23.5% and 44.4% of patients were negative for e-cadherin and ALDH1, respectively. Positive AR immunostaining was inversely correlated with a higher Ki-67 (p < 0.0001 and a lympho-vascular invasion (p = 0.01, but no other variables. Univariate survival analysis revealed that AR expression was not associated with disease-free survival (p = 0.72 or overall survival (p = 0.93. Conclusions: The expression of AR is associated with some biological features of TNBC, such as Ki-67 and lympho-vascular invasion; nevertheless the prognostic significance of AR was not documented in our analysis. However, since ARs are expressed in a significant number of TNBC, prospective studies in order to determine the biological mechanisms and their potential role as novel treatment target.

  4. Androgen Receptor Expression in Early Triple-Negative Breast Cancer: Clinical Significance and Prognostic Associations

    Energy Technology Data Exchange (ETDEWEB)

    Pistelli, Mirco, E-mail: mirco.pistelli@alice.it; Caramanti, Miriam [Clinica di Oncologia Medica, AO Ospedali Riuniti-Ancona, Università Politecnica delle Marche, Ancona 60020 (Italy); Biscotti, Tommasina; Santinelli, Alfredo [Anatomia Patologica, AO Ospedali Riuniti-Ancona, Università Politecnica delle Marche, Ancona 60020 (Italy); Pagliacci, Alessandra; De Lisa, Mariagrazia; Ballatore, Zelmira; Ridolfi, Francesca; Maccaroni, Elena; Bracci, Raffaella; Berardi, Rossana; Battelli, Nicola; Cascinu, Stefano [Clinica di Oncologia Medica, AO Ospedali Riuniti-Ancona, Università Politecnica delle Marche, Ancona 60020 (Italy)

    2014-06-27

    Background: Triple-negative breast cancers (TNBC) are characterized by aggressive tumour biology resulting in a poor prognosis. Androgen receptor (AR) is one of newly emerging biomarker in TNBC. In recent years, ARs have been demonstrated to play an important role in the genesis and in the development of breast cancer, although their prognostic role is still debated. In the present study, we explored the correlation of AR expression with clinical, pathological and molecular features and its impact on prognosis in early TNBC. Patients and Methods: ARs were considered positive in case of tumors with >10% nuclear-stained. Survival distribution was estimated by the Kaplan Meier method. The univariate and multivariate analyses were performed. The difference among variables were calculated by chi-square test. Results: 81 TNBC patients diagnosed between January 2006 and December 2011 were included in the analysis. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER-2, Ki-67, ALDH1, e-cadherin and AR. Of the 81 TNBC samples, 18.8% showed positive immunostaining for AR, 23.5% and 44.4% of patients were negative for e-cadherin and ALDH1, respectively. Positive AR immunostaining was inversely correlated with a higher Ki-67 (p < 0.0001) and a lympho-vascular invasion (p = 0.01), but no other variables. Univariate survival analysis revealed that AR expression was not associated with disease-free survival (p = 0.72) or overall survival (p = 0.93). Conclusions: The expression of AR is associated with some biological features of TNBC, such as Ki-67 and lympho-vascular invasion; nevertheless the prognostic significance of AR was not documented in our analysis. However, since ARs are expressed in a significant number of TNBC, prospective studies in order to determine the biological mechanisms and their potential role as novel treatment target.

  5. Androgen Receptor Expression in Early Triple-Negative Breast Cancer: Clinical Significance and Prognostic Associations

    International Nuclear Information System (INIS)

    Pistelli, Mirco; Caramanti, Miriam; Biscotti, Tommasina; Santinelli, Alfredo; Pagliacci, Alessandra; De Lisa, Mariagrazia; Ballatore, Zelmira; Ridolfi, Francesca; Maccaroni, Elena; Bracci, Raffaella; Berardi, Rossana; Battelli, Nicola; Cascinu, Stefano

    2014-01-01

    Background: Triple-negative breast cancers (TNBC) are characterized by aggressive tumour biology resulting in a poor prognosis. Androgen receptor (AR) is one of newly emerging biomarker in TNBC. In recent years, ARs have been demonstrated to play an important role in the genesis and in the development of breast cancer, although their prognostic role is still debated. In the present study, we explored the correlation of AR expression with clinical, pathological and molecular features and its impact on prognosis in early TNBC. Patients and Methods: ARs were considered positive in case of tumors with >10% nuclear-stained. Survival distribution was estimated by the Kaplan Meier method. The univariate and multivariate analyses were performed. The difference among variables were calculated by chi-square test. Results: 81 TNBC patients diagnosed between January 2006 and December 2011 were included in the analysis. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER-2, Ki-67, ALDH1, e-cadherin and AR. Of the 81 TNBC samples, 18.8% showed positive immunostaining for AR, 23.5% and 44.4% of patients were negative for e-cadherin and ALDH1, respectively. Positive AR immunostaining was inversely correlated with a higher Ki-67 (p < 0.0001) and a lympho-vascular invasion (p = 0.01), but no other variables. Univariate survival analysis revealed that AR expression was not associated with disease-free survival (p = 0.72) or overall survival (p = 0.93). Conclusions: The expression of AR is associated with some biological features of TNBC, such as Ki-67 and lympho-vascular invasion; nevertheless the prognostic significance of AR was not documented in our analysis. However, since ARs are expressed in a significant number of TNBC, prospective studies in order to determine the biological mechanisms and their potential role as novel treatment target

  6. Multiply charged negative ions of hydrogen in linearly polarized laser fields

    International Nuclear Information System (INIS)

    van Duijn, E.; Muller, H.G.

    1997-01-01

    Motivated by the prediction of the appearance of atomic multiply charged negative ions (AMCNI) of hydrogen, induced by a linearly polarized laser field, we present an analytical quantum mechanical treatment of the appearance and structure of AMCNI in a linearly polarized field, based on high-frequency Floquet theory (HFFT). For the simplest AMCNI of hydrogen, H 2- and H 3- , the values of α 0 at which the first bound state appears are α 0 =1.62x10 2 and α 0 =1.02x10 4 , where α 0 =I 1/2 /ω 2 is the amplitude of the oscillation of a free electron in the field with frequency ω and intensity I (unless stated otherwise, we use atomic units throughout this paper). Whereas in vacuum at least one of the electrons of an AMCNI autodetaches, an intense high-frequency field can change the character of the ion dramatically, such that bound states of AMCNI can appear. Due to the interaction with the field, the electrons of the AMCNI oscillate in phase along the polarization axis. This open-quotes quiverclose quotes motion enables the electrons to be spatially separated over distances of order α 0 , reducing the repulsive e-e interaction as α 0 increases. In other words, for α 0 large enough, the field enables a configuration in which the electrons, while widely separated, are bound to one proton. For the prediction of bound states of H N- with N>3, however, a relativistic description or low-frequency theory is required. copyright 1997 The American Physical Society

  7. Speciation and Biofilm Production of Coagulase Negative Staphylococcal Isolates from Clinically Significant Specimens and their Antibiogram

    Directory of Open Access Journals (Sweden)

    S. S. Vijayasri Badampudi

    2016-04-01

    Full Text Available Background: Coagulase Negative Staphylococci (CONS are increasingly recognized as significant nosocomial pathogens. Their ability of biofilm formation and multiple drug resistance are causing serious human infections. Aim and Objectives: To isolate, identify, speciate clinically significant CONS from various specimens, to study antibiotic resistance pattern and biofilm production. Material and Methods: Specimens were collected aseptically, processed and identified upto the species level by a simple scheme of tests urease, novobiocin resistance, mannose and mannitol fermentation, ornithine decarboxylase. Antibiotic sensitivity was done with special reference to methicillin resistance. Biofilm formation was detected by Congo Red Agar (CRA method and Tube Method (TM. Results: Study groupOf 100 isolates majority were pus (40, followed by urine (28, blood (16, CSF (5, body fluids (4 and catheter tips and implants (7. The most common species isolated was S. epidermidis (40% followed by S. haemolyticus (26%, S. saprophyticus (15%, S. schleiferi (13%, S. simulans (2%, S. cohnii (2% and S. warneri and S. capitis each 1%. Resistance to penicillin was 91% followed by ampicillin (79%, cotrimoxazole (67%. Methicillin resistance was 72%. Biofilm producers were 69% by CRAmethod and 33% by TM with majority species S. epidermidis (82.5%- CRA and 55%-TM. Biofilm production was significantly associated with MRCONS (p value 0.0036. Control group-Of 30 isolates were S. epidermidis 66.6% followed by S. haemolyticus (16.66%. Biofilm producers were 53.33% by CRA method and 26.65% by TM with majority species S. epidermidis (65%-CRA and 30%-TM.Methicillin resistance was 26.6%. Conclusion: Clinical significance of CONS is increasing day by day, so there is a need for accurate identification to species level and their antibiogram to avoid multidrug resistance. Biofilm producing CONS species pose a risk and CRA method for screening biofilm can be used in all conventional

  8. Multilevel linear modelling of the response-contingent learning of young children with significant developmental delays.

    Science.gov (United States)

    Raab, Melinda; Dunst, Carl J; Hamby, Deborah W

    2018-02-27

    The purpose of the study was to isolate the sources of variations in the rates of response-contingent learning among young children with multiple disabilities and significant developmental delays randomly assigned to contrasting types of early childhood intervention. Multilevel, hierarchical linear growth curve modelling was used to analyze four different measures of child response-contingent learning where repeated child learning measures were nested within individual children (Level-1), children were nested within practitioners (Level-2), and practitioners were nested within the contrasting types of intervention (Level-3). Findings showed that sources of variations in rates of child response-contingent learning were associated almost entirely with type of intervention after the variance associated with differences in practitioners nested within groups were accounted for. Rates of child learning were greater among children whose existing behaviour were used as the building blocks for promoting child competence (asset-based practices) compared to children for whom the focus of intervention was promoting child acquisition of missing skills (needs-based practices). The methods of analysis illustrate a practical approach to clustered data analysis and the presentation of results in ways that highlight sources of variations in the rates of response-contingent learning among young children with multiple developmental disabilities and significant developmental delays. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Role of tumor microenvironment in triple-negative breast cancer and its prognostic significance

    Institute of Scientific and Technical Information of China (English)

    Tianjian Yu; Genhong Di

    2017-01-01

    Breast cancer has been shown to live in the tumor microenvironment,which consists of not only breast cancer cells themselves but also a significant amount of pathophysiologically altered surrounding stroma and cells.Diverse components of the breast cancer microenvironment,such as suppressive immune cells,re-programmed fibroblast cells,altered extracellular matrix (ECM) and certain soluble factors,synergistically impede an effective anti-tumor response and promote breast cancer progression and metastasis.Among these components,stromal cells in the breast cancer microenvironment are characterized by molecular alterations and aberrant signaling pathways,whereas the ECM features biochemical and biomechanical changes.However,triple-negative breast cancer (TNBC),the most aggressive subtype of this disease that lacks effective therapies available for other subtypes,is considered to feature a unique microenvironment distinct from that of other subtypes,especially compared to Luminal A subtype.Because these changes are now considered to significantly impact breast cancer development and progression,these unique alterations may serve as promising prognostic factors of clinical outcome or potential therapeutic targets for the treatment of TNBC.In this review,we focus on the composition of the TNBC microenvironment,concomitant distinct biological alteration,specific interplay between various cell types and TNBC cells,and the prognostic implications of these findings.

  10. Significance tests to determine the direction of effects in linear regression models.

    Science.gov (United States)

    Wiedermann, Wolfgang; Hagmann, Michael; von Eye, Alexander

    2015-02-01

    Previous studies have discussed asymmetric interpretations of the Pearson correlation coefficient and have shown that higher moments can be used to decide on the direction of dependence in the bivariate linear regression setting. The current study extends this approach by illustrating that the third moment of regression residuals may also be used to derive conclusions concerning the direction of effects. Assuming non-normally distributed variables, it is shown that the distribution of residuals of the correctly specified regression model (e.g., Y is regressed on X) is more symmetric than the distribution of residuals of the competing model (i.e., X is regressed on Y). Based on this result, 4 one-sample tests are discussed which can be used to decide which variable is more likely to be the response and which one is more likely to be the explanatory variable. A fifth significance test is proposed based on the differences of skewness estimates, which leads to a more direct test of a hypothesis that is compatible with direction of dependence. A Monte Carlo simulation study was performed to examine the behaviour of the procedures under various degrees of associations, sample sizes, and distributional properties of the underlying population. An empirical example is given which illustrates the application of the tests in practice. © 2014 The British Psychological Society.

  11. The region of influence of significant defects and the mechanical vibrations of linear elastic solids

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2004-12-01

    The presence of cracks, voids or fields of pores, and their growth under applied forces or environmental actions, can produce a meaningful lowering in the proper frequencies of normal modes of mechanical vibration in machines and structures. A quite general expression for the square of modes proper frequency as a functional of displacement field, density field and elastic moduli fields is used as a starting point. The effect of defects on frequency are modeled as equivalent changes in density and elastic moduli fields, introducing the concept of region of influence of each defect. This region of influence is derived from the relation between the stress field of flawed components in machines or structures, and the elastic energy released from a suitable reference state, due to the presence of significant defects in the above mentioned mechanical components. An approximate analytical expression is obtained, which relates the relative variation in the square of mode s proper frequency with position, size, shape and orientation of defects in mode displacement field. Some simple mathematical models of machine and structural elements with cracks or fields of pores are considered as examples. The connections between the relative lowering in the square of mode s proper frequency and the stress intensity factor of a defect are discussed : the concept of region of influence of a defect is used as a bridge between (low frequency and low amplitude) vibration dynamics and linear elastic fracture mechanics. Some limitations of the present approach are discussed as well as the possibility of applying the region of influence of defects to the damping of normal modes of vibration

  12. A non-linear association between self-reported negative emotional response to stress and subsequent allostatic load

    DEFF Research Database (Denmark)

    Dich, Nadya; Doan, Stacey N; Kivimäki, Mika

    2014-01-01

    dysregulation. Allostatic load also increased with age, but the association between negative emotional response and allostatic load remained stable over time. These results provide evidence for a more nuanced understanding of the role of negative emotions in long-term physical health....... response to major life events and allostatic load, a multisystem indicator of physiological dysregulation. Study sample was 6764 British civil service workers from the Whitehall II cohort. Negative emotional response was assessed by self-report at baseline. Allostatic load was calculated using...... cardiovascular, metabolic and immune function biomarkers at three clinical follow-up examinations. A non-linear association between negative emotional response and allostatic load was observed: being at either extreme end of the distribution of negative emotional response increased the risk of physiological...

  13. High ALK mRNA expression has a negative prognostic significance in rhabdomyosarcoma

    Science.gov (United States)

    Bonvini, P; Zin, A; Alaggio, R; Pawel, B; Bisogno, G; Rosolen, A

    2013-01-01

    Background: Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in cancer, but its clinical and functional importance remain controversial. Mutation or amplification of ALK, as well as its expression levels assessed by conventional immunohistochemistry methods, has been linked to prognosis in cancer, although with potential bias because of the semi-quantitative approaches. Herein, we measured ALK mRNA expression in rhabdomyosarcoma (RMS) and determined its clinical impact on patients' stratification and outcome. Methods: Specimens were obtained from RMS patients and cell lines, and ALK expression was analysed by quantitative RT–PCR, western blotting, IHC, and copy number analysis. Results: High ALK mRNA expression was detected in the vast majority of PAX3/7-FOXO1-positive tumours, whereas PAX3/7-FOXO1-negative RMS displayed considerably lower amounts of both mRNA and protein. Notably, ALK mRNA distinguished unfavourable PAX3/7-FOXO1-positive tumours from PAX3/7-FOXO1-negative RMS (Ptumour size (PALK mRNA levels were of prognostic relevance by Cox univariate regression analysis and correlated with increased risk of relapse (P=0.001) and survival (P=0.01), whereas by multivariate analysis elevated ALK mRNA expression resulted a negative prognostic marker when clinical stage was not included. Conclusion: Quantitative assessment of ALK mRNA expression helps to improve risk stratification of RMS patients and identifies tumours with adverse biological characteristics and aggressive behaviour. PMID:24149177

  14. Comparison of linear and zero-inflated negative binomial regression models for appraisal of risk factors associated with dental caries.

    Science.gov (United States)

    Batra, Manu; Shah, Aasim Farooq; Rajput, Prashant; Shah, Ishrat Aasim

    2016-01-01

    Dental caries among children has been described as a pandemic disease with a multifactorial nature. Various sociodemographic factors and oral hygiene practices are commonly tested for their influence on dental caries. In recent years, a recent statistical model that allows for covariate adjustment has been developed and is commonly referred zero-inflated negative binomial (ZINB) models. To compare the fit of the two models, the conventional linear regression (LR) model and ZINB model to assess the risk factors associated with dental caries. A cross-sectional survey was conducted on 1138 12-year-old school children in Moradabad Town, Uttar Pradesh during months of February-August 2014. Selected participants were interviewed using a questionnaire. Dental caries was assessed by recording decayed, missing, or filled teeth (DMFT) index. To assess the risk factor associated with dental caries in children, two approaches have been applied - LR model and ZINB model. The prevalence of caries-free subjects was 24.1%, and mean DMFT was 3.4 ± 1.8. In LR model, all the variables were statistically significant. Whereas in ZINB model, negative binomial part showed place of residence, father's education level, tooth brushing frequency, and dental visit statistically significant implying that the degree of being caries-free (DMFT = 0) increases for group of children who are living in urban, whose father is university pass out, who brushes twice a day and if have ever visited a dentist. The current study report that the LR model is a poorly fitted model and may lead to spurious conclusions whereas ZINB model has shown better goodness of fit (Akaike information criterion values - LR: 3.94; ZINB: 2.39) and can be preferred if high variance and number of an excess of zeroes are present.

  15. Significant and variable linear polarization during the prompt optical flash of GRB 160625B.

    Science.gov (United States)

    Troja, E.; Lipunov, V. M.; Mundell, C. G.; Butler, N. R.; Watson, A. M.; Kobayashi, S.; Cenko, S. B.; Marshall, F. E.; Ricci, R.; Fruchter, A.; Wieringa, M. H.; Gorbovskoy, E. S.; Kornilov, V.; Kutyrev, A.; Lee, W. H.; Toy, V.; Tyurina, N. V.; Budnev, N. M.; Buckley, D. A. H.; González, J.; Gress, O.; Horesh, A.; Panasyuk, M. I.; Prochaska, J. X.; Ramirez-Ruiz, E.; Rebolo Lopez, R.; Richer, M. G.; Roman-Zuniga, C.; Serra-Ricart, M.; Yurkov, V.; Gehrels, N.

    2017-07-01

    Newly formed black holes of stellar mass launch collimated outflows (jets) of ionized matter that approach the speed of light. These outflows power prompt, brief and intense flashes of γ-rays known as γ-ray bursts (GRBs), followed by longer-lived afterglow radiation that is detected across the electromagnetic spectrum. Measuring the polarization of the observed GRB radiation provides a direct probe of the magnetic fields in the collimated jets. Rapid-response polarimetric observations of newly discovered bursts have probed the initial afterglow phase, and show that, minutes after the prompt emission has ended, the degree of linear polarization can be as high as 30 per cent - consistent with the idea that a stable, globally ordered magnetic field permeates the jet at large distances from the central source. By contrast, optical and γ-ray observations during the prompt phase have led to discordant and often controversial results, and no definitive conclusions have been reached regarding the origin of the prompt radiation or the configuration of the magnetic field. Here we report the detection of substantial (8.3 ± 0.8 per cent from our most conservative simulation), variable linear polarization of a prompt optical flash that accompanied the extremely energetic and long-lived prompt γ-ray emission from GRB 160625B. Our measurements probe the structure of the magnetic field at an early stage of the jet, closer to its central black hole, and show that the prompt phase is produced via fast-cooling synchrotron radiation in a large-scale magnetic field that is advected from the black hole and distorted by dissipation processes within the jet.

  16. An investigation of the linear energy transfer distribution in a beam of negative pi-mesons

    International Nuclear Information System (INIS)

    Lewis, C.A.

    1979-07-01

    A review of the possible therapeutic advantages of negative pions is given and the more prolific of the dedicated facilities are described. The results are given of an examination of the microdosimetry of negative pion absorption in tissue through the measurement of event size spectra with proportional counters, and of the subsequent unfolding of these spectra in terms of LET distributions. The parameters LET and event size are discussed and methods of deriving LET distributions from event size measurements examined. Experiments with three tissue equivalent proportional counters of different geometry at the Rutherford Laboratory negative pion facility are described and the processing of the event size data is discussed. Fractional absorbed dose in LET distributions are presented for each of the counters at various positions of interest over the negative pion ionization profile. Quality Factors have been calculated from the data taken with the spherical counters and a Quality Factor of 5 is suggested for a negative pion beam. Results of measurements at two neutron facilities, a cyclotron neutron source and a 14 MeV neutron source, are also presented. Anomalies in the derived LET distributions are discussed. (UK)

  17. LASR-Guided Variability Subtraction: The Linear Algorithm for Significance Reduction of Stellar Seismic Activity

    Science.gov (United States)

    Horvath, Sarah; Myers, Sam; Ahlers, Johnathon; Barnes, Jason W.

    2017-10-01

    Stellar seismic activity produces variations in brightness that introduce oscillations into transit light curves, which can create challenges for traditional fitting models. These oscillations disrupt baseline stellar flux values and potentially mask transits. We develop a model that removes these oscillations from transit light curves by minimizing the significance of each oscillation in frequency space. By removing stellar variability, we prepare each light curve for traditional fitting techniques. We apply our model to $\\delta$-Scuti KOI-976 and demonstrate that our variability subtraction routine successfully allows for measuring bulk system characteristics using traditional light curve fitting. These results open a new window for characterizing bulk system parameters of planets orbiting seismically active stars.

  18. Significant difference in p53 and p21 protein immunoreactivity in HPV 16 positive and HPV negative breast carcinomas

    International Nuclear Information System (INIS)

    Hennig, E.M.; Norwegian Radium Hospital, Oslo; Kvinnsland, S.; Holm, R.; Nesland, J.M.

    1999-01-01

    Human papillomavirus (HPV) 16 has previously been found in 19/41 breast carcinomas (46%) in women with a history of HPV 16 positive CIN III lesions. There was no significant difference in distribution of histological subtypes, mean or median tumour diameter or number of regional lymph node metastases in the HPV positive and HPV negative breast carcinoma groups. P53, p21 and c-erbB-2 proteins were analyzed by immunohistochemistry in the HPV 16 positive and HPV negative breast carcinomas. There was a significant difference in p53 and p21 protein immunoreactivity between HPV 16 positive and HPV negative breast carcinomas (p=0.0091 and p=0.0040), with a significant less detectable p53 and p21 protein immunoreactivity in the HPV 16 positive cases. There was also a significant difference in the coexpression of p53/p21 between the HPV 16 positive and HPV 16 negative breast carcinomas (p=0.002). No significant difference in immunostaining for c-erbB-2 protein in the two groups was found (p=0.15), or for the coexpression of p53/c-erbB-2 (p=0.19). The significantly lower expression of p53 and p21 proteins in HPV 16 positive than in HPV 16 negative breast carcinomas supports the hypothesis of inactivation and degradation of wild-type p53 proteins by HPV 16 E6 and that p53 mutation is not necessary for transformation in the HPV 16 positive cases. (orig.)

  19. Use of negative multinomial linear models to investigate environmental effects on community structure.

    Science.gov (United States)

    A frequent goal in ecology is to understand the relationships between biological communities and their environment. Anderson and McCardle (2001) provided a nonparametric method, known as Permanova, that is often used for this purpose. Permanova represents a significant advance,...

  20. Clinical significance of histologic chorioamnionitis with a negative amniotic fluid culture in patients with preterm labor and premature membrane rupture.

    Directory of Open Access Journals (Sweden)

    Jeong Woo Park

    Full Text Available To evaluate the effect of histological chorioamnionitis (HCA with a negative amniotic fluid (AF culture on adverse pregnancy and neonatal outcomes and inflammatory status in the AF compartment in women with preterm labor or preterm premature rupture of membranes (PPROM.This is a retrospective cohort study of 153 women diagnosed as having a preterm labor or PPROM (20-34 weeks who delivered singleton gestations within 48 hours of amniocentesis. AF obtained through amniocentesis was cultured, and interleukin (IL-6, IL-8, and metalloproteinase-9 (MMP-9 levels were determined. The placentas were examined histologically.The prevalence of HCA with negative AF culture was 23.5% (36/153. The women with HCA but with a negative AF culture (group 2 and those with a positive AF culture (group 3 had a significantly lower mean gestational age at amniocentesis and delivery than those with a negative AF culture and without HCA (group 1. Women in group 3 had the highest levels of AF IL-6, IL-8, and MMP-9, followed by those in group 2, and those in group 1. Composite neonatal morbidity was significantly higher in groups 2 and 3 than in group 1, but this was no longer significant after adjusting for confounders caused mainly by the impact of gestational age.In the women who delivered preterm neonates, HCA with a negative AF culture was associated with increased risks of preterm birth, intense intra-amniotic inflammatory response, and prematurity-associated composite neonatal morbidity, and its risks are similar to the risk posed by positive AF culture.

  1. Non-linear Heart Rate Variability as a Discriminator of Internalizing Psychopathology and Negative Affect in Children With Internalizing Problems and Healthy Controls

    Directory of Open Access Journals (Sweden)

    Charlotte Fiskum

    2018-05-01

    Full Text Available Background: Internalizing psychopathology and dysregulated negative affect are characterized by dysregulation in the autonomic nervous system and reduced heart rate variability (HRV due to increases in sympathetic activity alongside reduced vagal tone. The neurovisceral system is however, a complex nonlinear system, and nonlinear indices related to psychopathology are so far less studied in children. Essential nonlinear properties of a system can be found in two main domains: the informational domain and the invariant domain. sample entropy (SampEn is a much-used method from the informational domain, while detrended fluctuation analysis (DFA represents a widely-used method from the invariant domain. To see if nonlinear HRV can provide information beyond linear indices of autonomic activation, this study investigated SampEn and DFA as discriminators of internalizing psychopathology and negative affect alongside measures of vagally-mediated HRV and sympathetic activation.Material and Methods: Thirty-Two children with internalizing difficulties and 25 healthy controls (aged 9–13 were assessed with the Child Behavior Checklist and the Early Adolescent Temperament Questionnaire, Revised, giving an estimate of internalizing psychopathology, negative affect and effortful control, a protective factor against psychopathology. Five minute electrocardiogram and impedance cardiography recordings were collected during a resting baseline, giving estimates of SampEn, DFA short-term scaling exponent α1, root mean square of successive differences (RMSSD, and pre-ejection period (PEP. Between-group differences and correlations were assessed with parametric and non-parametric tests, and the relationships between cardiac variables, psychopathology and negative affect were assessed using generalized linear modeling.Results: SampEn and DFA were not significantly different between the groups. SampEn was weakly negatively related to heart rate (HR in the controls

  2. On the significance of the noise model for the performance of a linear MPC in closed-loop operation

    DEFF Research Database (Denmark)

    Hagdrup, Morten; Boiroux, Dimitri; Mahmoudi, Zeinab

    2016-01-01

    This paper discusses the significance of the noise model for the performance of a Model Predictive Controller when operating in closed-loop. The process model is parametrized as a continuous-time (CT) model and the relevant sampled-data filtering and control algorithms are developed. Using CT...... models typically means less parameters to identify. Systematic tuning of such controllers is discussed. Simulation studies are conducted for linear time-invariant systems showing that choosing a noise model of low order is beneficial for closed-loop performance. (C) 2016, IFAC (International Federation...

  3. Significance of coagulase negative Staphylococcus from blood cultures: persisting problems and partial progress in resource constrained settings.

    Science.gov (United States)

    Sidhu, Shailpreet K; Malhotra, Sita; Devi, Pushpa; Tuli, Arpandeep K

    2016-12-01

    Coagulase negative Staphylococcus (CoNS) is frequently isolated from blood cultures but their significance is difficult to interpret. CoNS bacteria which are often previously dismissed as culture contaminants are attracting greater importance as true pathogens in the past decades. Clinical evaluation of these isolates suggests that although there is a relative increase of CoNS associated bloodstream infections in recent years, the microorganisms still remain the most common contaminants in blood cultures. The objective of this study was to determine the significance of CoNS isolated from blood cultures. A retrospective study was conducted to evaluate the rate of contamination in blood cultures in a tertiary care hospital. The paired specimens of blood were cultured using conventional culture methods and the isolates of coagulase negative staphylococci were identified by standard methodology. Clinical data, laboratory indices, microbiological parameters and patient characteristics were analyzed. Of 3503 blood samples, CoNS were isolated from blood culture of 307 patients (8.76%). The isolates were reported as true pathogens of bloodstream infections in only 74 out of 307 cases (24.1%). In the vast majority, 212 of 307 (69.0%), they were mere blood culture contaminants and reported as insignificant/contaminant. Determining whether a growth in the blood culture is a pathogen or a contaminant is a critical issue and multiple parameters have to be considered before arriving at a conclusion. Ideally, the molecular approach is for the most part a consistent method in determining the significant isolates of CoNS. However, in countries with inadequate resources, species identification and antibiogram tests are recommended when determining significance of these isolates.

  4. Improving sensitivity of linear regression-based cell type-specific differential expression deconvolution with per-gene vs. global significance threshold.

    Science.gov (United States)

    Glass, Edmund R; Dozmorov, Mikhail G

    2016-10-06

    The goal of many human disease-oriented studies is to detect molecular mechanisms different between healthy controls and patients. Yet, commonly used gene expression measurements from blood samples suffer from variability of cell composition. This variability hinders the detection of differentially expressed genes and is often ignored. Combined with cell counts, heterogeneous gene expression may provide deeper insights into the gene expression differences on the cell type-specific level. Published computational methods use linear regression to estimate cell type-specific differential expression, and a global cutoff to judge significance, such as False Discovery Rate (FDR). Yet, they do not consider many artifacts hidden in high-dimensional gene expression data that may negatively affect linear regression. In this paper we quantify the parameter space affecting the performance of linear regression (sensitivity of cell type-specific differential expression detection) on a per-gene basis. We evaluated the effect of sample sizes, cell type-specific proportion variability, and mean squared error on sensitivity of cell type-specific differential expression detection using linear regression. Each parameter affected variability of cell type-specific expression estimates and, subsequently, the sensitivity of differential expression detection. We provide the R package, LRCDE, which performs linear regression-based cell type-specific differential expression (deconvolution) detection on a gene-by-gene basis. Accounting for variability around cell type-specific gene expression estimates, it computes per-gene t-statistics of differential detection, p-values, t-statistic-based sensitivity, group-specific mean squared error, and several gene-specific diagnostic metrics. The sensitivity of linear regression-based cell type-specific differential expression detection differed for each gene as a function of mean squared error, per group sample sizes, and variability of the proportions

  5. Outcomes in Young Women With Breast Cancer of Triple-Negative Phenotype: The Prognostic Significance of CK19 Expression

    International Nuclear Information System (INIS)

    Parikh, Rahul R.; Yang Qifeng; Higgins, Susan A.; Haffty, Bruce G.

    2008-01-01

    Purpose: Basal-like carcinoma of the breast is associated with genetic instability and aggressive behavior. In this study, we evaluated the luminal cytokeratin marker CK-19 in young women with breast cancer treated with conservative surgery and radiation therapy (CS+RT). Methods: Primary tumor specimens from a cohort of 158 young premenopausal women (range, 25-49 years) treated with CS+RT with a median follow-up of 6.25 years were constructed into a tissue microarray. The array was stained for ER, PR, HER2, CK19, and p53. The molecular profiles were correlated with clinical-pathologic factors, overall, local, and distant relapse-free survival. The association between CK19, other co-variables, and outcome was assessed in a multivariate model. Results: Positive expression of ER, PR, HER-2/neu, CK19, and p53 were 33.1%, 34.5%, 10.0%, 79.5%, and 20.9%, respectively. With 20 local relapses and 38 distant metastases, the 10-year overall, breast relapse-free, and distant relapse-free survival were 79.65%, 87.29%, and 67.35%, respectively. Tumor stage and nodal status were associated with distant relapse-free and overall survival. In multivariate analysis, CK19 negativity was a predictor poor local (RR, 3.54; 95% CI, 1.87-7.65; p < 0.01) distant (RR, 1.44; 95% CI, 0.86-2.70; p = 0.17), and overall survival (RR, 1.89; 95% CI, 1.04-3.55; p = 0.03). Conclusions: Lack of CK19 expression identifies a subset of patients with a significantly higher risk of local relapse. Distant relapse and overall survival rates also correlated with CK19 negativity. Further evaluation of the prognostic significance of basal and luminal cytokeratins in young women with breast cancer is warranted

  6. Significant changes in sexual behavior after a diagnosis of human papillomavirus-positive and human papillomavirus-negative oral cancer.

    Science.gov (United States)

    Taberna, Miren; Inglehart, Ronald C; Pickard, Robert K L; Fakhry, Carole; Agrawal, Amit; Katz, Mira L; Gillison, Maura L

    2017-04-01

    Sexual behavior and oral human papillomavirus (HPV) infection are risk factors for oral squamous cell carcinoma (OSCC). The effects of OSCC diagnosis and treatment on subsequent relationship stress and sexual behavior are unknown. Incident cases of HPV-positive or HPV-negative OSCC in patients who had a partnered relationship and partners of patients with oropharyngeal cancer were eligible for a study in which surveys were administered at diagnosis and at the 6-month follow-up time point to assess relationship distress, HPV transmission and concerns about health consequences, and sexual behavior. The frequency distributions of responses, stratified by tumor HPV status, were compared at baseline and follow-up. In total, 262 patients with OSCC and 81 partners were enrolled. Among the patients, 142 (54.2%) had HPV-positive OSCC, and 120 (45.8%) had HPV-negative OSCC. Relationship distress was infrequently reported, and 69% of patients felt that their relationship had strengthened since the cancer diagnosis. Both HPV-positive patients (25%) and their partners (14%) reported feelings of guilt or responsibility for the diagnosis of an HPV-caused cancer. Concern over sexual, but not nonsexual, HPV transmission to partners was reported by 50%. Significant declines in the frequency of vaginal and oral sexual behaviors were reported at follow-up, regardless of tumor HPV status. From baseline to 6 months, significant increases in abstinence from vaginal sex (from 10% to 34%; P oral sex (from 25% to 80%; P oral sex, regardless of tumor HPV status. Sexual behavior is an important quality-of-life outcome to assess within clinical trials. [See related editorial on pages 000-000, this issue.] Cancer 2017. © 2017 American Cancer Society. Cancer 2017;123:1156-1165. © 2016 American Cancer Society. © 2017 American Cancer Society.

  7. Correction of the significance level when attempting multiple transformations of an explanatory variable in generalized linear models

    Science.gov (United States)

    2013-01-01

    Background In statistical modeling, finding the most favorable coding for an exploratory quantitative variable involves many tests. This process involves multiple testing problems and requires the correction of the significance level. Methods For each coding, a test on the nullity of the coefficient associated with the new coded variable is computed. The selected coding corresponds to that associated with the largest statistical test (or equivalently the smallest pvalue). In the context of the Generalized Linear Model, Liquet and Commenges (Stat Probability Lett,71:33–38,2005) proposed an asymptotic correction of the significance level. This procedure, based on the score test, has been developed for dichotomous and Box-Cox transformations. In this paper, we suggest the use of resampling methods to estimate the significance level for categorical transformations with more than two levels and, by definition those that involve more than one parameter in the model. The categorical transformation is a more flexible way to explore the unknown shape of the effect between an explanatory and a dependent variable. Results The simulations we ran in this study showed good performances of the proposed methods. These methods were illustrated using the data from a study of the relationship between cholesterol and dementia. Conclusion The algorithms were implemented using R, and the associated CPMCGLM R package is available on the CRAN. PMID:23758852

  8. Extracting real-crack properties from non-linear elastic behaviour of rocks: abundance of cracks with dominating normal compliance and rocks with negative Poisson ratios

    Directory of Open Access Journals (Sweden)

    V. Y. Zaitsev

    2017-09-01

    Full Text Available Results of examination of experimental data on non-linear elasticity of rocks using experimentally determined pressure dependences of P- and S-wave velocities from various literature sources are presented. Overall, over 90 rock samples are considered. Interpretation of the data is performed using an effective-medium description in which cracks are considered as compliant defects with explicitly introduced shear and normal compliances without specifying a particular crack model with an a priori given ratio of the compliances. Comparison with the experimental data indicated abundance (∼ 80 % of cracks with the normal-to-shear compliance ratios that significantly exceed the values typical of conventionally used crack models (such as penny-shaped cuts or thin ellipsoidal cracks. Correspondingly, rocks with such cracks demonstrate a strongly decreased Poisson ratio including a significant (∼ 45 % portion of rocks exhibiting negative Poisson ratios at lower pressures, for which the concentration of not yet closed cracks is maximal. The obtained results indicate the necessity for further development of crack models to account for the revealed numerous examples of cracks with strong domination of normal compliance. Discovering such a significant number of naturally auxetic rocks is in contrast to the conventional viewpoint that occurrence of a negative Poisson ratio is an exotic fact that is mostly discussed for artificial structures.

  9. Minimising negative externalities cost using 0-1 mixed integer linear programming model in e-commerce environment

    Directory of Open Access Journals (Sweden)

    Akyene Tetteh

    2017-04-01

    Full Text Available Background: Although the Internet boosts business profitability, without certain activities like efficient transportation, scheduling, products ordered via the Internet may reach their destination very late. The environmental problems (vehicle part disposal, carbon monoxide [CO], nitrogen oxide [NOx] and hydrocarbons [HC] associated with transportation are mostly not accounted for by industries. Objectives: The main objective of this article is to minimising negative externalities cost in e-commerce environments. Method: The 0-1 mixed integer linear programming (0-1 MILP model was used to model the problem statement. The result was further analysed using the externality percentage impact factor (EPIF. Results: The simulation results suggest that (1 The mode of ordering refined petroleum products does not impact on the cost of distribution, (2 an increase in private cost is directly proportional to the externality cost, (3 externality cost is largely controlled by the government and number of vehicles used in the distribution and this is in no way influenced by the mode of request (i.e. Internet or otherwise and (4 externality cost may be reduce by using more ecofriendly fuel system.

  10. Characterization and Prognosis Significance of JAK2 (V617F), MPL, and CALR Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    OpenAIRE

    Singdong, Roongrudee; Siriboonpiputtana, Teerapong; Chareonsirisuthigul, Takol; Kongruang, Adcharee; Limsuwanachot, Nittaya; Sirirat, Tanasan; Chuncharunee, Suporn; Rerkamnuaychoke, Budsaba

    2016-01-01

    Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical ...

  11. THE PROGNOSIS SIGNIFICANCE OF CATHEPSIN-D EXPRESSION IN THE DIFFERENT LOCATIONS IN AXILLARY NODES NEGATIVE CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: The aim of this study was to investigate Cathepsin-D (Cath-D) expression in different location and its relationship with prognosis in the axillary lymph nodes negative (ANN) breast cancer patients. Methods: Cath-D expression in 192 cases of breast carcinoma were examined by immunohistochemistry. Depending on different parts of expression, three evaluating methods were used, compared and analysed. Results: The positive rate of Cath-D expression in ANN breast cancer with poor prognosis group and axillary nodes positive (ANP) group were significantly higher than that in ANN breast cancer with good prognosis group (x2=23.20, P0.05). Cath-D expression in stromal cells had no statistical difference among the three groups (x2=1.56, P>0.05). When the Cath-D expression in cancer and stromal cells were counted into the positive rate, it was near the same (u1=0.47, u2=1.41, P>0.05). Conclusion: These results suggest that Cath-D expression is one of the powerful prognostic markers in ANN breast cancer. It's a reliable, practical, and convenient method to observe and evaluate Cath-D expression in cancer cells.

  12. Using the Coefficient of Determination "R"[superscript 2] to Test the Significance of Multiple Linear Regression

    Science.gov (United States)

    Quinino, Roberto C.; Reis, Edna A.; Bessegato, Lupercio F.

    2013-01-01

    This article proposes the use of the coefficient of determination as a statistic for hypothesis testing in multiple linear regression based on distributions acquired by beta sampling. (Contains 3 figures.)

  13. Cancellation of OpAmp virtual ground imperfections by a negative conductance applied to improve RF receiver linearity

    NARCIS (Netherlands)

    Mahrof, D.H.; Klumperink, Eric A.M.; Ru, Z.; Oude Alink, M.S.; Nauta, Bram

    2014-01-01

    High linearity CMOS radio receivers often exploit linear V-I conversion at RF, followed by passive down-mixing and an OpAmp-based Transimpedance Amplifier at baseband. Due to nonlinearity and finite gain in the OpAmp, virtual ground is imperfect, inducing distortion currents. This paper proposes a

  14. Characterization and Prognosis Significance of JAK2 (V617F), MPL, and CALR Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    Science.gov (United States)

    Singdong, Roongrudee; Siriboonpiputtana, Teerapong; Chareonsirisuthigul, Takol; Kongruang, Adcharee; Limsuwanachot, Nittaya; Sirirat, Tanasan; Chuncharunee, Suporn; Rerkamnuaychoke, Budsaba

    2016-10-01

    Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical presentation, disease progression, and treatment outcome. Material and Methods: Pyrosequencing was performed to detect JAK2 (V617F) and MPL (W515K/L) and capillary electrophoresis to identify CALR exon 9.0 mutations in 100.0 samples of Ph-negative MPNs (38.0 PV, 55 ET, 4 PMF, and 3 MPN-U). Results: The results showed somatic mutations of JAK2 (V617F) in 94.7% of PV, 74.5% of ET, 25.0% of PMF, and all MPN-U. A high proportion of JAK2 (V617F) mutant allele burden (mutational load > 50.0%) was predominantly observed in PV when compared with ET. Although a high level of JAK2 (V617F) allele burden was strongly associated with high WBC counts in both PV and ET, several hematological parameters (hemoglobin, hematocrit, and platelet count) were independent of JAK2 (V617F) mutational load. MPL (W515K/L) mutations could not be detected whereas CALR exon 9.0 mutations were identified in 35.7% of patients with JAK2 negative ET and 33.3% with JAK2 negative PMF. Conclusions: The JAK2 (V617F) allele burden may be involved in progression of MPNs. Furthermore, a high level of JAK2 (V617F) mutant allele appears strongly associated with leukocytosis in both PV and ET. Creative Commons Attribution License

  15. A non-linear association between self-reported negative emotional response to stress and subsequent allostatic load: prospective results from the Whitehall II cohort study.

    Science.gov (United States)

    Dich, Nadya; Doan, Stacey N; Kivimäki, Mika; Kumari, Meena; Rod, Naja Hulvej

    2014-11-01

    Previous research suggests that high levels of negative emotions may affect health. However, it is likely that the absence of an emotional response following stressful events may also be problematic. Accordingly, we investigated whether a non-linear association exists between negative emotional response to major life events and allostatic load, a multisystem indicator of physiological dysregulation. Study sample was 6764 British civil service workers from the Whitehall II cohort. Negative emotional response was assessed by self-report at baseline. Allostatic load was calculated using cardiovascular, metabolic and immune function biomarkers at three clinical follow-up examinations. A non-linear association between negative emotional response and allostatic load was observed: being at either extreme end of the distribution of negative emotional response increased the risk of physiological dysregulation. Allostatic load also increased with age, but the association between negative emotional response and allostatic load remained stable over time. These results provide evidence for a more nuanced understanding of the role of negative emotions in long-term physical health. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. The low risk of precancer after a screening result of human papillomavirus-negative/atypical squamous cells of undetermined significance papanicolaou and implications for clinical management.

    Science.gov (United States)

    Gage, Julia C; Katki, Hormuzd A; Schiffman, Mark; Castle, Philip E; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas; Cheung, Li C; Behrens, Catherine; Sharma, Abha; Zhao, Fang-Hui; Cuzick, Jack; Yang, Zi Hua; Kinney, Walter K

    2014-11-01

    Different US practice guidelines have conflicting recommendations for when women should return after a screening result of human papillomavirus (HPV)-negative with an equivocal Papanicolaou (Pap) result of atypical squamous cells of undetermined significance (ASC-US) (ie, return in either 3 or 5 years). One way to determine management is to compare the risk of precancer/cancer after an HPV-negative/ASC-US result with the risks after other negative screening results. For example, if the risk after an HPV-negative/ASC-US result was similar to the risk after a negative Pap test, a 3-year return would be preferred because guidelines agree that women with negative Pap test results should return in 3 years. Alternatively, if the risk after an HPV-negative/ASC-US result is similar to that after a cotest-negative result (HPV negative/Pap test negative), a 5-year return would be preferred because guidelines agree that women testing cotest negative should return in 5 years. The authors compared risks of cervical intraepithelial neoplasia of grade 3 or higher (CIN3+) and cervical cancer among women aged 30 years to 64 years at Kaiser Permanente Northern California with the following test results from 2003 through 2012: 17,191 women testing HPV negative/ASC-US; 980,268 women testing Pap test negative (regardless of HPV result); and 892,882 women testing cotest negative. The 5-year CIN3+ and cancer risks after an HPV-negative/ASC-US result were closer to the risks after a negative Pap test result (CIN3+: 0.48% vs 0.31% [P =.0019]; and cancer: 0.043% vs 0.031% [P =.4]) than after a negative cotest (CIN3+: 0.48% vs 0.11% [P<.0001]; and cancer: 0.043% vs 0.014% [P =.016]). Women testing HPV negative/ASC-US were found to have precancer/cancer risks that were more closely aligned with women with negative Pap test results, suggesting that women testing HPV negative/ASC-US should be managed similarly to women testing negative on Pap tests with a 3-year return for screening. © 2014

  17. Significance of definitions of relapse after discontinuation of oral antivirals in HBeAg-negative chronic hepatitis B.

    Science.gov (United States)

    Papatheodoridis, George V; Manolakopoulos, Spilios; Su, Tung-Hung; Siakavellas, Spyros; Liu, Chun-Jen; Kourikou, Anastasia; Yang, Hung-Chih; Kao, Jia-Horng

    2017-08-31

    Relapses are observed in most hepatitis B e antigen (HBeAg)-negative chronic hepatitis B patients who discontinue treatment with nucleos(t)ide analogues (NAs); however, the rates of relapse vary widely among studies, and whether all patients with relapse need retreatment is unclear. The aim of this study was to assess the impact of different definitions on the rates of posttreatment relapse and therefore on the probability of retreatment in patients who have discontinued effective long-term NA therapy. In total, 130 HBeAg-negative chronic hepatitis B patients without cirrhosis and before NA treatment were included. All had on-therapy virological remission for ≥24 months and close follow-up for ≥12 months after stopping NA treatment or until retreatment, which started on stringent predefined criteria. Relapses rates based on several predetermined definitions of virological and perhaps biochemical criteria were assessed. The median duration of therapy was 60 months and the median duration of on-therapy virological remission was 43 months. During a median off-NAs follow-up of 15 months, no patient experienced liver decompensation or died. Cumulative relapse rates were 2%-49%, 4%-73%, 11%-82%, and 16%-90% at 3, 6, 12, and 24 months, respectively, whereas cumulative retreatment rates were 15%, 22%, and 40% at 6, 12, and 24 months, respectively, after discontinuation of NA therapy. No patient characteristic was independently associated with the probability of relapse based on at least two definitions or of retreatment. In HBeAg-negative chronic hepatitis B patients who discontinue NA therapy, the definition of relapse has a great impact on off-NAs relapse rates and potentially on the probability of retreatment. Regardless of definition, off-NAs relapses cannot be easily predicted by patient characteristics. A substantial proportion of such patients may not require retreatment if stringent criteria are adopted. (Hepatology 2017). © 2017 by the American Association

  18. Solutions for Determining the Significance Region Using the Johnson-Neyman Type Procedure in Generalized Linear (Mixed) Models

    Science.gov (United States)

    Lazar, Ann A.; Zerbe, Gary O.

    2011-01-01

    Researchers often compare the relationship between an outcome and covariate for two or more groups by evaluating whether the fitted regression curves differ significantly. When they do, researchers need to determine the "significance region," or the values of the covariate where the curves significantly differ. In analysis of covariance (ANCOVA),…

  19. Analyses of significant features of L-Prolinium Picrate single crystal: An excellent material for non linear optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi, 110012 (India); CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vij, Mahak [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Nagaraja, C.M. [Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, 140001, Punjab (India); Jayaramakrishnan, V. [Centro De Investigations En Optica, Loma del Bosque 115, Colonia Lomas del Campestre, León, Guanajuato, Código Postal, 37150 (Mexico); Jayalakshmy, M.S. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, 686560 (India); Kant, Rajni [Department of Physics and Electronics, University of Jammu, Jammu Tawi, 180006 (India)

    2017-06-15

    Today the fundamental aspect of the researchers is to explore maximum physical properties of the material for device fabrication. In the present article, single crystal X-ray diffraction has been carried out to verify the formation of the synthesized compound. In addition to that, powder X-ray diffraction has been performed to obtain diffraction pattern of L-Prolinium Picrate single crystal. The strain present inside the single crystal was measured using Hall-Williamson equation from PXRD measurements. The dark current and photon current was obtained from photoconductivity technique whose plot depicted that the sample was negative photoconducting material. Optical homogeneity of the single crystal was analyzed using birefringence technique. Its resistance towards Nd: YAG laser was scrutinized for L-Prolinium Picrate single crystal by applying 1 pulse per second. Different thermal parameters like thermal conductivity, thermal diffusivity, thermal effusivity and specific heat were computed using photo-pyroelectric technique. Solid state parameters were calculated from Clausius Mossotti relation by taking structural information of the title compound. Also, optical parameters like refractive index, reflectance etc were calculated through UV–Vis–NIR analysis. - Highlights: • An optically transparent L-Prolinium Picrate single crystal was harvested from slow evaporation solution growth technique. • The compound shows negative photoconducting nature. • Its optical homogeneity was analyzed using birefringence. • Single shot of laser was applied to sample to measure laser damage threshold value. • The thermal parameters were computed from Photopyroelectric technique.

  20. Targeted Nanoparticles for Image-guided Treatment of Triple Negative Breast Cancer: Clinical Significance and Technological Advances

    Science.gov (United States)

    Miller-Kleinhenz, Jasmine M.; Bozeman, Erica N.

    2015-01-01

    Effective treatment of triple negative breast cancer (TNBC) with its aggressive tumor biology, highly heterogeneous tumor cells, and poor prognosis requires an integrated therapeutic approach that addresses critical issues in cancer therapy. Multifunctional nanoparticles with the abilities of targeted drug delivery and non-invasive imaging for monitoring drug delivery and responses to therapy, such as theranostic nanoparticles, hold great promise towards the development of novel therapeutic approaches for the treatment of TNBC using a single therapeutic platform. The biological and pathological characteristics of TNBC provide insight into several potential molecular targets for current and future nanoparticle based therapeutics. Extensive tumor stroma, highly proliferative cells, and a high rate of drug-resistance are all barriers that must be appropriately addressed in order for these nanotherapeutic platforms to be effective. Utilization of the enhanced permeability and retention (EPR) effect coupled with active targeting of cell surface receptors expressed by TNBC cells, and tumor associated endothelial cells, stromal fibroblasts and macrophages is likely to overcome such barriers to facilitate more effective drug delivery. An in depth summary of current studies investigating targeted nanoparticles in preclinical TNBC mouse and human xenograft models is presented. This review aims to outline the current status of nanotherapeutic options for TNBC patients, identification of promising molecular targets, challenges associated with the development of targeted nanotherapeutics, the research done by our group as well as others and future perspectives on the nanomedicine field and ways to translate current preclinical studies into the clinic. PMID:25966677

  1. Targeted nanoparticles for image-guided treatment of triple-negative breast cancer: clinical significance and technological advances.

    Science.gov (United States)

    Miller-Kleinhenz, Jasmine M; Bozeman, Erica N; Yang, Lily

    2015-01-01

    Effective treatment of triple-negative breast cancer (TNBC) with its aggressive tumor biology, highly heterogeneous tumor cells, and poor prognosis requires an integrated therapeutic approach that addresses critical issues in cancer therapy. Multifunctional nanoparticles with the abilities of targeted drug delivery and noninvasive imaging for monitoring drug delivery and responses to therapy, such as theranostic nanoparticles, hold great promise toward the development of novel therapeutic approaches for the treatment of TNBC using a single therapeutic platform. The biological and pathological characteristics of TNBC provide insight into several potential molecular targets for current and future nanoparticle-based therapeutics. Extensive tumor stroma, highly proliferative cells, and a high rate of drug resistance are all barriers that must be appropriately addressed in order for these nanotherapeutic platforms to be effective. Utilization of the enhanced permeability and retention effect coupled with active targeting of cell surface receptors expressed by TNBC cells, and tumor-associated endothelial cells, stromal fibroblasts, and macrophages is likely to overcome such barriers to facilitate more effective drug delivery. An in-depth summary of current studies investigating targeted nanoparticles in preclinical TNBC mouse and human xenograft models is presented. This review aims to outline the current status of nanotherapeutic options for TNBC patients, identification of promising molecular targets, challenges associated with the development of targeted nanotherapeutics, the research done by our group as well as by others, and future perspectives on the nanomedicine field and ways to translate current preclinical studies into the clinic. © 2015 Wiley Periodicals, Inc.

  2. Lift force fluctuations of magnetically levitated vehicles with an integrated synchronous linear motor and their significance for the technical security

    Energy Technology Data Exchange (ETDEWEB)

    Mnich, P; Huebner, K D

    1980-07-15

    In this paper the influence of the motor current on the magnetic force is investigated by an analytical method. With the integrated synchronous linear motor the reactions of the current sheet on the excitation field are depending on the pole angle and the amplitude of the current sheet. For an undisturbed operation - current sheet and induction wave in phase - the influence of the motor current on the magnetic force can be neglected. In case of a disturbed performance, i.e. when the pole angle is changing periodically, fluctuations of the magnetic force will be found. This effect has to be compensated by a reserve magnetic force in the levitation control. With the technical data for the new magnetic levitation pilots plants (International Traffic Fair 1979 at Hamburg and Transrapid - Pilot Plant Emsland) the stated relations are evaluated. Approximated relations for the levitation force are derived. For comparison, a finite-difference computer programme from the 'Institut fuer elektrische Maschinen, Antriebe und Bahnen, Technische Universitaet Braunschweig' is applied. The approximated relations developed in this paper are verified - with a sufficient precision - by the numerical calculations.

  3. Anomalous thermal expansion, negative linear compressibility, and high-pressure phase transition in ZnAu2(CN) 4 : Neutron inelastic scattering and lattice dynamics studies

    Science.gov (United States)

    Gupta, Mayanak K.; Singh, Baltej; Mittal, Ranjan; Zbiri, Mohamed; Cairns, Andrew B.; Goodwin, Andrew L.; Schober, Helmut; Chaplot, Samrath L.

    2017-12-01

    We present temperature-dependent inelastic-neutron-scattering measurements, accompanied by ab initio calculations of the phonon spectra and elastic properties as a function of pressure to quantitatively explain an unusual combination of negative thermal expansion and negative linear compressibility behavior of ZnAu2(CN) 4 . The mechanism of the negative thermal expansion is identified in terms of specific anharmonic phonon modes that involve bending of the -Zn-NC-Au-CN-Zn- linkage. The soft phonon at the L point at the Brillouin zone boundary quantitatively relates to the high-pressure phase transition at about 2 GPa. The ambient pressure structure is also found to be close to an elastic instability that leads to a weakly first-order transition.

  4. The mediational significance of negative/depressive affect in the relationship of childhood maltreatment and eating disorder features in adolescent psychiatric inpatients.

    Science.gov (United States)

    Hopwood, C J; Ansell, E B; Fehon, D C; Grilo, C M

    2011-03-01

    Childhood maltreatment is a risk factor for eating disorder and negative/depressive affect appears to mediate this relation. However, the specific elements of eating- and body-related psychopathology that are influenced by various forms of childhood maltreatment remain unclear, and investigations among adolescents and men/boys have been limited. This study investigated the mediating role of negative affect/depression across multiple types of childhood maltreatment and eating disorder features in hospitalized adolescent boys and girls. Participants were 148 adolescent psychiatric inpatients who completed an assessment battery including measures of specific forms of childhood maltreatment (sexual, emotional, and physical abuse), negative/depressive affect, and eating disorder features (dietary restriction, binge eating, and body dissatisfaction). Findings suggest that for girls, negative/depressive affect significantly mediates the relationships between childhood maltreatment and eating disorder psychopathology, although effects varied somewhat across types of maltreatment and eating disorder features. Generalization of mediation effects to boys was limited.

  5. Prognostic significance of the total number of harvested lymph nodes for lymph node-negative gastric cancer patients.

    Science.gov (United States)

    Ji, Xin; Bu, Zhao-De; Li, Zi-Yu; Wu, Ai-Wen; Zhang, Lian-Hai; Zhang, Ji; Wu, Xiao-Jiang; Zong, Xiang-Long; Li, Shuang-Xi; Shan, Fei; Jia, Zi-Yu; Ji, Jia-Fu

    2017-08-22

    The relationship between the number of harvested lymph nodes (HLNs) and prognosis of gastric cancer patients without an involvement of lymph nodes has not been well-evaluated. The objective of this study is to further explore this issue. We collected data from 399 gastric cancer patients between November 2006 and October 2011. All of them were without metastatic lymph nodes. Survival analyses showed that statistically significant differences existed in the survival outcomes between the two groups allocated by the total number of HLNs ranging from 16 to 22. Therefore, we adopted 22 as the cut-off value of the total number of HLNs for grouping (group A: HLNs <22; group B: HLNs≥22). The intraoperative and postoperative characteristics, including operative blood loss (P=0.096), operation time (P=0.430), postoperative hospital stay (P=0.142), complications (P=0.552), rate of reoperation (P=0.966) and postoperative mortality (P=1.000), were comparable between the two groups. T-stage-stratified Kaplan-Meier analyses revealed that the 5-year survival rate of patients at the T4 stage was better in group B than in group A (76.9% vs. 58.5%; P=0.004). An analysis of multiple factors elucidated that the total number of HLNs, T stage, operation time and age were independently correlated factors of prognosis. Regarding gastric cancer patients without the involvement of lymph nodes, an HLN number ≥22 would be helpful in prolonging their overall survival, especially for those at T4 stage. The total number of HLNs was an independent prognostic factor for this population of patients.

  6. Fertilization of sea urchin eggs and sperm motility are negatively impacted under low hypergravitational forces significant to space flight

    Science.gov (United States)

    Tash, J. S.; Kim, S.; Schuber, M.; Seibt, D.; Kinsey, W. H.

    2001-01-01

    Sperm and other flagellates swim faster in microgravity (microG) than in 1 G, raising the question of whether fertilization is altered under conditions of space travel. Such alterations have implications for reproduction of plant and animal food and for long-term space habitation by man. We previously demonstrated that microG accelerates protein phosphorylation during initiation of sperm motility but delays the sperm response to the egg chemotactic factor, speract. Thus sperm are sensitive to changes in gravitational force. New experiments using the NiZeMi centrifugal microscope examined whether low hypergravity (hyperG) causes effects opposite to microG on sperm motility, signal transduction, and fertilization. Sperm % motility and straight-line velocity were significantly inhibited by as little as 1.3 G. The phosphorylation states of FP130, an axonemal phosphoprotein, and FP160, a cAMP-dependent salt-extractable flagellar protein, both coupled to motility activation, showed a more rapid decline in hyperG. Most critically, hyperG caused an approximately 50% reduction in both the rate of sperm-egg binding and fertilization. The similar extent of inhibition of both fertilization parameters in hyperG suggests that the primary effect is on sperm rather than eggs. These results not only support our earlier microG data demonstrating that sperm are sensitive to small changes in gravitational forces but more importantly now show that this sensitivity affects the ability of sperm to fertilize eggs. Thus, more detailed studies on the impact of space flight on development should include studies of sperm function and fertilization.

  7. Prognostic significance of ASXL1, JAK2V617F mutations and JAK2V617F allele burden in Philadelphia-negative myeloproliferative neoplasms

    Directory of Open Access Journals (Sweden)

    Yonal-Hindilerden I

    2015-06-01

    Full Text Available Ipek Yonal-Hindilerden, Aynur Daglar-Aday, Basak Akadam-Teker, Ceylan Yilmaz, Meliha Nalcaci, Akif Selim Yavuz, Deniz SarginDivision of Hematology, Department of Internal Medicine, Istanbul Medical Faculty, Istanbul University, Fatih-Istanbul, Turkey Background: Despite insights into the genetic basis of Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs, a significant proportion of essential thrombocythemia (ET and primary myelofibrosis (PMF patients present with no known MPN disease alleles. There were no previous studies investigating the impact of ASXL1 mutations in Ph-negative MPNs in Turkey. In the current study, we investigated the prognostic significance of ASXL1 mutations in Turkish MPN patients. We also aimed to determine the prognostic significance of JAK2V617F allele burden and the relationship of JAK2V617F mutation with ASXL1 mutations in Ph-negative MPNs. Methods: About 184 patients from a single center diagnosed with Ph-negative MPNs were screened for ASXL1, JAK2V617F mutations, and JAK2V617F allele burden: 107 ET and 77 PMF. Results: A total of 29 ASXL1 mutations were detected in 24.7% of PMF and 8.4% of ET patients. ASXL1-mutated ET patients showed a trend toward an increase in the incidence of cerebrovascular events and higher total leukocyte counts. ASXL1-mutation in PMF was associated with older age and a higher prevalence of bleeding complications. In univariate analysis, overall survival (OS was significantly reduced in ASXL1-mutated PMF patients. In multivariate analysis, Dynamic International Prognostic Scoring System-plus high-risk category and ASXL1 mutation status were independently associated with shorter survival in PMF. In PMF, mutational status and allele burden of JAK2V617F showed no difference in terms of OS and leukemia-free survival. Conclusion: We conclude that ASXL1 mutations are molecular predictors of short OS in PMF. Keywords: Philadelphia-negative myeloproliferative neoplasms (Ph-negative

  8. Addendum to the article: Misuse of null hypothesis significance testing: Would estimation of positive and negative predictive values improve certainty of chemical risk assessment?

    Science.gov (United States)

    Bundschuh, Mirco; Newman, Michael C; Zubrod, Jochen P; Seitz, Frank; Rosenfeldt, Ricki R; Schulz, Ralf

    2015-03-01

    We argued recently that the positive predictive value (PPV) and the negative predictive value (NPV) are valuable metrics to include during null hypothesis significance testing: They inform the researcher about the probability of statistically significant and non-significant test outcomes actually being true. Although commonly misunderstood, a reported p value estimates only the probability of obtaining the results or more extreme results if the null hypothesis of no effect was true. Calculations of the more informative PPV and NPV require a priori estimate of the probability (R). The present document discusses challenges of estimating R.

  9. Individuals with clinically significant insomnia symptoms are characterised by a negative sleep-related expectancy bias: Results from a cognitive-experimental assessment.

    Science.gov (United States)

    Courtauld, Hannah; Notebaert, Lies; Milkins, Bronwyn; Kyle, Simon D; Clarke, Patrick J F

    2017-08-01

    Cognitive models of insomnia consistently suggest that negative expectations regarding the consequences of poor sleep contribute to the maintenance of insomnia. To date, however, no research has sought to determine whether insomnia is indeed characterised by such a negative sleep-related expectancy bias, using objective cognitive assessment tasks which are more immune to response biases than questionnaire assessments. Therefore, the current study employed a reaction-time task assessing biased expectations among a group with clinically significant insomnia symptoms (n = 30) and a low insomnia symptoms group (n = 40). The task involved the presentation of scenarios describing the consequences of poor sleep, and non-sleep related activities, which could be resolved in a benign or a negative manner. The results demonstrated that the high insomnia symptoms group were disproportionately fast to resolve sleep-related scenarios in line with negative outcomes, as compared to benign outcomes, relative to the low insomnia symptoms group. The two groups did not differ in their pattern of resolving non-sleep related scenarios. This pattern of findings is entirely consistent with a sleep-specific expectancy bias operating in individuals with clinically significant insomnia symptoms, and highlights the potential of cognitive-experimental assessment tasks to objectively index patterns of biased cognition in insomnia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The Clinical and Genomic Significance of Donor-Specific Antibody–Positive/C4d-Negative and Donor-Specific Antibody–Negative/C4d-Negative Transplant Glomerulopathy

    Science.gov (United States)

    Hayde, Nicole; Bao, Yi; Pullman, James; Ye, Bin; Calder, R. Brent; Chung, Monica; Schwartz, Daniel; Lubetzky, Michelle; Ajaimy, Maria; de Boccardo, Graciela

    2013-01-01

    Summary Background This study investigated the mechanisms involved in development of donor-specific antibody (DSA) and/or C4d-negative transplant glomerulopathy (TGP) by allograft gene expression profiles using microarrays. Design, Setting, Participants, & Measurements This cohort study was conducted in kidney transplant recipients. Patients were eligible for inclusion if they required a clinically indicated biopsy at any time point after their transplant. They were then classified according to their histopathology findings and DSA and C4d results. Eighteen chronic antibody-mediated rejection (CAMR), 14 DSA+/C4d− TGP, 25 DSA−/C4d− TGP, and 47 nonspecific interstitial fibrosis/tubular atrophy (IFTA) biopsy specimens were identified. In a subset of patients from the study population, biopsy specimens in each group and normal transplant kidney specimens were analyzed with Affymetrix Human Gene 1.0 ST Arrays. Results The mean sum score of glomerulitis and peritubular capillaritis increased from 0.28±0.78 in IFTA specimens to 0.75±0.85 in DSA−/C4d− TGP specimens, 1.71±1.49 in DSA+/C4d−/TGP specimens, and 2.11±1.74 in CAMR specimens (PTGP specimens (14.3%), and DSA−/C4d− TGP specimens (16%) (P=0.01). With use of microarrays, comparison of the gene expression profiles of DSA−/C4d− TGP specimens with glomerulitis + peritubular capillaritis scores > 0 to normal and IFTA biopsy specimens revealed higher expression of quantitative cytotoxic T cell–associated transcripts (QCAT). However, both CAMR and DSA+/C4d− TGP specimens had higher expression of not only QCAT but also IFN-γ and rejection-induced, constitutive macrophage-associated, natural killer cell–associated, and DSA-selective transcripts. Endothelial cell–associated transcript expression was upregulated only in CAMR biopsy specimens. Conclusions These results suggested that DSA+/C4d− TGP biopsy specimens may be classified as CAMR. In contrast, DSA−/C4d− TGP specimens showed

  11. The clinical and genomic significance of donor-specific antibody-positive/C4d-negative and donor-specific antibody-negative/C4d-negative transplant glomerulopathy.

    Science.gov (United States)

    Hayde, Nicole; Bao, Yi; Pullman, James; Ye, Bin; Calder, R Brent; Chung, Monica; Schwartz, Daniel; Lubetzky, Michelle; Ajaimy, Maria; de Boccardo, Graciela; Akalin, Enver

    2013-12-01

    This study investigated the mechanisms involved in development of donor-specific antibody (DSA) and/or C4d-negative transplant glomerulopathy (TGP) by allograft gene expression profiles using microarrays. This cohort study was conducted in kidney transplant recipients. Patients were eligible for inclusion if they required a clinically indicated biopsy at any time point after their transplant. They were then classified according to their histopathology findings and DSA and C4d results. Eighteen chronic antibody-mediated rejection (CAMR), 14 DSA+/C4d- TGP, 25 DSA-/C4d- TGP, and 47 nonspecific interstitial fibrosis/tubular atrophy (IFTA) biopsy specimens were identified. In a subset of patients from the study population, biopsy specimens in each group and normal transplant kidney specimens were analyzed with Affymetrix Human Gene 1.0 ST Arrays. The mean sum score of glomerulitis and peritubular capillaritis increased from 0.28±0.78 in IFTA specimens to 0.75±0.85 in DSA-/C4d- TGP specimens, 1.71±1.49 in DSA+/C4d-/TGP specimens, and 2.11±1.74 in CAMR specimens (PTGP specimens (14.3%), and DSA-/C4d- TGP specimens (16%) (P=0.01). With use of microarrays, comparison of the gene expression profiles of DSA-/C4d- TGP specimens with glomerulitis + peritubular capillaritis scores > 0 to normal and IFTA biopsy specimens revealed higher expression of quantitative cytotoxic T cell-associated transcripts (QCAT). However, both CAMR and DSA+/C4d- TGP specimens had higher expression of not only QCAT but also IFN-γ and rejection-induced, constitutive macrophage-associated, natural killer cell-associated, and DSA-selective transcripts. Endothelial cell-associated transcript expression was upregulated only in CAMR biopsy specimens. These results suggested that DSA+/C4d- TGP biopsy specimens may be classified as CAMR. In contrast, DSA-/C4d- TGP specimens showed increased cytotoxic T cell-associated transcripts, suggesting T cell activation as a mechanism of injury.

  12. Increased superior frontal gyrus activation during working memory processing in psychosis: Significant relation to cumulative antipsychotic medication and to negative symptoms.

    Science.gov (United States)

    Vogel, Tobias; Smieskova, Renata; Schmidt, André; Walter, Anna; Harrisberger, Fabienne; Eckert, Anne; Lang, Undine E; Riecher-Rössler, Anita; Graf, Marc; Borgwardt, Stefan

    2016-08-01

    Impairment in working memory (WM) is a core symptom in schizophrenia. However, little is known about how clinical features influence functional brain activity specific to WM processing during the development of first-episode psychosis (FEP) to schizophrenia (SZ). We compared functional WM-specific brain activity in FEP and SZ patients, including the effects of the duration of illness, psychopathological factors and antipsychotic medication. Cross-sectional study of male FEP (n=22) and SZ (n=20) patients performing an n-back task when undergoing functional magnetic resonance imaging (fMRI). Clinical features were collected by semi-structured interviews and medical records. The SZ group performed significantly worse than the FEP group in the 2-back condition. The SZ group also showed significantly higher activation in the left superior frontal gyrus in the 2-back versus 0-back condition (2-back>0-back). This frontal activation correlated positively with negative symptoms and with cumulative antipsychotic medication during the year before the fMRI examination. There were no significant correlations between activation and duration of illness. There was greater frontal neural activation in SZ than in FEP. This indicated differences in WM processing, and was significantly related to cumulative antipsychotic exposure and negative symptoms, but not to the duration of illness. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Significance of a negative exercise thallium test in the presence of a critical residual stenosis after thrombolysis for acute myocardial infarction

    International Nuclear Information System (INIS)

    Sutton, J.M.; Topol, E.J.

    1991-01-01

    After thrombolytic therapy for acute myocardial infarction, increasing emphasis is placed on early submaximal exercise testing, with further intervention advocated only for demonstrable ischemia. Although significant residual coronary artery lesions after successful thrombolysis are common, many patients paradoxically have no corresponding provokable ischemia. The relation between significant postthrombolytic residual coronary artery disease and a negative early, submaximal exercise thallium-201 tomogram was studied among 101 consecutive patients with uncomplicated myocardial infarction and at least 70% residual stenosis of the infarct artery. A negative test occurred in 49 (48.5%) patients with a mean 88% residual infarct artery stenosis. Further characteristics of the group were as follows: mean time to treatment was 3.1 hours; mean age was 54 +/- 10 years; 80% were male; 47% had anterior infarction; 39% had multivessel disease; mean left ventricular ejection fraction was 53 +/- 14%; and mean peak creatine kinase level was 3,820 +/- 3,123 IU/ml. A similar group of 52 (51.5%) patients, treated within 3.3 hours from symptom onset, with a mean postthrombolysis stenosis of 90%, had a positive exercise test. Characteristics of this group were as follows: age was 58 +/- 10 years; 92% were male; 56% had anterior infarction; 40% had multivessel disease; and mean left ventricular ejection fraction was 54 +/- 15%. The peak creatine kinase level associated with the infarction, however, was lower: 2,605 +/- 1,805 IU/ml (p = 0.04). There was no difference in performance at exercise testing with respect to peak systolic pressure, peak heart rate, or time tolerated on the treadmill between the two groups. By multivariate logistic regression, only peak creatine kinase level predicted a negative stress result in the presence of a significant residual stenosis

  14. Impact of age on the false negative rate of human papillomavirus DNA test in patients with atypical squamous cells of undetermined significance.

    Science.gov (United States)

    Won, Kyu-Hee; Lee, Jae Yeon; Cho, Hye-Yon; Suh, Dong Hoon; No, Jae Hong; Kim, Yong-Beom

    2015-03-01

    Human papillomavirus (HPV) test was incorporated into the triage of lesser abnormal cervical cytologies: atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL). This study aimed to evaluate the impact of age on the efficacy of HPV testing in patients with lesser abnormal cervical cytologies. A total of 439 patients with ASCUS or LSIL were included. The association between age groups and the diagnostic performances of HPV test for high-grade cervical intraepithelial neoplasia (CIN2+) was evaluated. Median age was 44 years (range, 17 to 75 years). ASCUS was more frequently observed in older patients while LSIL was more common in younger patients (P=0.002). CIN2+ was found in 11.3% (32/284) of the ASCUS patients and 12.9% (20/155) of patients with LSIL. Older patients with ASCUS showed lower HPV infection rates (P=0.025), but not LSIL (P=0.114). However, the prevalence of CIN2+ was similar between the age groups with ASCUS or LSIL. In patients with ASCUS, the false negative rate of HPV test for CIN2+ was 6.2%. The false negative rate of the HPV test became higher with increasing of the age after the age of 50 (P=0.034). Our findings suggest that false negative rate of the HPV test for CIN2+ in ASCUS patients older than 50 years might become higher with increasing of the age. Negative HPV results in patients of the age >50 years with ASCUS should be carefully interpreted.

  15. Linear gate

    International Nuclear Information System (INIS)

    Suwono.

    1978-01-01

    A linear gate providing a variable gate duration from 0,40μsec to 4μsec was developed. The electronic circuity consists of a linear circuit and an enable circuit. The input signal can be either unipolar or bipolar. If the input signal is bipolar, the negative portion will be filtered. The operation of the linear gate is controlled by the application of a positive enable pulse. (author)

  16. [Clinical significance of JAK2、CALR and MPL gene mutations in 1 648 Philadelphia chromosome negative myeloproliferative neoplasms patients from a single center].

    Science.gov (United States)

    Li, M Y; Chao, H Y; Sun, A N; Qiu, H Y; Jin, Z M; Tang, X W; Han, Y; Fu, C C; Chen, S N; Wu, D P

    2017-04-14

    Objective: To explore the prevalences of JAK2, CALR and MPL gene mutations and the mutation types in patients with Philadelphia chromosome negative myeloproliferative neoplasms (MPNs) , and to compare their clinical characteristics of different mutation types with each other and mutation negative group. Methods: The mutations of JAK2 V617F, JAK2 gene at exon 12, CALR gene at exon 9 and MPL gene at exon 10 in 1 648 Ph negative MPNs patients were detected by direct sequencing. Results: ① The JAK2V617F mutation was found in 471 (92.7%) of 508 PV patients, 819 (78.1%) of 1 049 ET patients and 74 (81.3%) of 91 PMF patients respectively, with the total mutation rate as 82.8% (1 364/1 648) . The JAK2 exon12 mutation was found in 9 (1.7%) of 508 PV patients, none was found in ET or PMF patients, with the total mutation rate as 0.5% (9/1 648) . The CALR mutation was found in 132 (12.6%) of 1 049 ET patients and 11 (12.1%) of 91 PMF patients respectively, with the total mutation rate as 8.7% (143/1 648) ; the MPL mutation was found in 9 (0.9%) of 1 049 ET patients and 1 (1.1%) of 91 PMF patients respectively, with the total mutation rate as 0.6% (10/1 648) . The co-occurrence of any two types of driver gene mutations was not detected by direct sequencing. ②The median onset age of patients with JAK2V617F[61 (15-95) y] was significant higher than of with JAK2 exon12 mutation[49 (33-62) y] or without mutations[42 (3-78) y] ( P MPL mutation[59 (22-71) y] ( P >0.05) . Patients with JAK2V617F had higher white blood cell count and hemoglobin level ( P MPL mutation ( P =0.013) . The platelet count of patients with CALR mutation was significantly higher than of with JAK2V617F[966 (400-2 069) ×10(9)/L vs 800 (198-3 730) ×10(9)/L, P MPL gene mutation revealed normal karyotype. Conclusions: Driver gene mutations detection could ensure the diagnosis and prognosis judgment of MPN more reliable, different subtypes of MPNs had different profiles of driver gene mutations, the latter

  17. Prognostic significance of proline, glutamic acid, leucine rich protein 1 (PELP1) in triple-negative breast cancer: a retrospective study on 129 cases

    International Nuclear Information System (INIS)

    Zhang, Yanzhi; Dai, Jiali; McNamara, Keely M.; Bai, Bing; Shi, Mumu; Chan, Monica S. M.; Liu, Ming; Sasano, Hironobu; Wang, Xiuli; Li, Xiaolei; Liu, Lijuan; Ma, Ying; Cao, Shuwen; Xing, Yanchun; Zhao, Baoshan; Song, Yinli; Wang, Lin

    2015-01-01

    Triple-negative breast cancer (TNBC) is associated with an aggressive clinical course due to the lack of therapeutic targets. Therefore, identifying reliable prognostic biomarkers and novel therapeutic targets for patients with TNBC is required. Proline, glutamic acid, leucine rich protein 1 (PELP1) is a novel steroidal receptor co-regulator, functioning as an oncogene and its expression is maintained in estrogen receptor (ER) negative breast cancers. PELP1 has been proposed as a prognostic biomarker in hormone-related cancers, including luminal-type breast cancers, but its significance in TNBC has not been studied. PELP1 immunoreactivity was evaluated using immunohistochemistry in 129 patients with TNBC. Results were correlated with clinicopathological variables including patient’s age, tumor size, lymph node stage, tumor grade, clinical stage, histological type, Ki-67 LI, as well as clinical outcome of the patients, including disease-free survival (DFS) and overall survival (OS). PELP1 was localized predominantly in the nuclei of carcinoma cells in TNBC. With the exception of a positive correlation between PELP1 protein expression and lymph node stage (p = 0.027), no significant associations between PELP1 protein expression and other clinicopathological variables, including DFS and OS, were found. However, when PELP1 and Ki-67 LI were grouped together, we found that patients in the PELP1/Ki-67 double high group (n = 48) demonstrated significantly reduced DFS (p = 0.005, log rank test) and OS (p = 0.002, log rank test) than others (n = 81). Multivariable analysis supported PELP1/Ki-67 double high expression as an independent prognostic factor in patients with TNBC, with an adjusted hazard ratio of 2.020 for recurrence (95 % CL, 1.022–3.990; p = 0.043) and of 2.380 for death (95 % CL, 1.138–4.978; p = 0.021). We found that evaluating both PELP1 and Ki-67 expression in TNBC could enhance the prognostic sensitivity of the two biomarkers. Therefore, we propose

  18. Age and associated fibrocystic changes are prognostically significant in patients with small node-negative (T1a,bN0) invasive breast cancer.

    Science.gov (United States)

    Durak, Merih Guray; Gonzalez-Angulo, Ana M; Hanrahan, Emer O; Broglio, Kristine R; Valero, Vicente; Hortobagyi, Gabriel N; Hunt, Kelly K; Sahin, Aysegul A

    2011-01-01

    Some patients with small (≤1.0 cm) node-negative (T1a,bN0) invasive breast cancer (IBC) who undergo only local therapy experience recurrences. There is limited information on prognostic factors in these patients. We sought to identify prognostic factors associated with disease-free survival (DFS) and overall survival (OS) in patients with T1a,bN0 IBC. Histologic sections from 273 T1a,bN0 IBC patients treated at M. D. Anderson Cancer Center (MDACC) between 1980 and 1999 were reviewed. Microscopic tumor size; multifocality; histologic type, grade of tumor; presence, type, grade of associated ductal carcinoma in situ (DCIS); presence of fibrocystic changes (FCC) with/without atypia; and lymphovascular invasion were identified. The Kaplan-Meier method was used to evaluate DFS and OS. Median patient age was 58 years, median follow-up period was 10.8 years, and median tumor size was 0.8 cm. Multifocal disease was identified in 26% of cases. At 10 years, the DFS and OS rates were 91% and 88%, respectively. Twenty-one percent of patients had extensive (>50%), and 30% had grade 3 DCIS. Nonproliferative FCC and proliferative FCC with/without atypia were present in 80%, 36%, and 38% of patients, respectively. In univariate analysis, age at diagnosis (p < 0.0001), grade (p = 0.015), and percent (p = 0.046) of DCIS were significantly associated with DFS; presence of FCC was associated with longer DFS and OS. In multivariable models, age and presence of FCC remained significantly associated with survival. Age at diagnosis and associated FCC are significant factors in predicting recurrence in patients with T1a,bN0 IBC. Adjuvant systemic therapy should be discussed with and considered for young patients with T1a,bN0 IBC. © 2011 Wiley Periodicals, Inc.

  19. Silibinin and Paclitaxel Cotreatment Significantly Suppress the Activity and Lung Metastasis of Triple Negative 4T1 Mammary Tumor Cell in Mice

    Directory of Open Access Journals (Sweden)

    Bing-Ying Ho

    2012-10-01

    Full Text Available The in vitro and in vivo bioactivities of silibinin (SB, paclitaxel (PTX and SB and PTX in combination (SB+PTX against murine metastatic mammary 4T1 cancer cell line were investigated. Isobologram and combination index (CI analyses showed that SB and PTX can function synergistically in the inhibition of 4T1 cell proliferation with a CI value<1. Both SB and PTX alone or SB+PTX treatment inhibited 4T1 cell migration and motility possibly through downregulation of the serpin protease nexin-1 (PN-1 and N-cadherin expression, inhibition of matrix metalloprotease (MMP-9 activity, and upregulation of E-cadherin. Flow cytometry and Western blot analyses demonstrated that both drugs deregulated cell-cycle mediators and induced apoptosis in 4T1 cells. A real-time in vivo bioluminescence imaging system to monitor the breast cancer cell metastasis in syngeneic BALB/c mice was established using a stable 4T1pGL−COX−2/Luc cell clone carrying a COX-2 promoter driven-luciferase reporter gene. In vivo study using the allograft 4T1pGL−COX−2/Luc metastatic mouse model indicated that SB co-treated with PTX can significantly suppress lung metastasis of 4T1 cells likely through inhibiting cell proliferation and angiogenesis. Together, this study demonstrates that SB could act synergistically with PTX in 4T1 cells, providing a therapeutic option for highly metastatic triple negative breast cancer.

  20. Conjugation of 10 kDa Linear PEG onto Trastuzumab Fab' Is Sufficient to Significantly Enhance Lymphatic Exposure while Preserving in Vitro Biological Activity.

    Science.gov (United States)

    Chan, Linda J; Ascher, David B; Yadav, Rajbharan; Bulitta, Jürgen B; Williams, Charlotte C; Porter, Christopher J H; Landersdorfer, Cornelia B; Kaminskas, Lisa M

    2016-04-04

    The lymphatic system is a major conduit by which many diseases spread and proliferate. There is therefore increasing interest in promoting better lymphatic drug targeting. Further, antibody fragments such as Fabs have several advantages over full length monoclonal antibodies but are subject to rapid plasma clearance, which can limit the lymphatic exposure and activity of Fabs against lymph-resident diseases. This study therefore explored ideal PEGylation strategies to maximize biological activity and lymphatic exposure using trastuzumab Fab' as a model. Specifically, the Fab' was conjugated with single linear 10 or 40 kDa PEG chains at the hinge region. PEGylation led to a 3-4-fold reduction in binding affinity to HER2, but antiproliferative activity against HER2-expressing BT474 cells was preserved. Lymphatic pharmacokinetics were then examined in thoracic lymph duct cannulated rats after intravenous and subcutaneous dosing at 2 mg/kg, and the data were evaluated via population pharmacokinetic modeling. The Fab' displayed limited lymphatic exposure, but conjugation of 10 kDa PEG improved exposure by approximately 11- and 5-fold after intravenous (15% dose collected in thoracic lymph over 30 h) and subcutaneous (9%) administration, respectively. Increasing the molecular weight of the PEG to 40 kDa, however, had no significant impact on lymphatic exposure after intravenous (14%) administration and only doubled lymphatic exposure after subcutaneous administration (18%) when compared to 10 kDa PEG-Fab'. The data therefore suggests that minimal PEGylation has the potential to enhance the exposure and activity of Fab's against lymph-resident diseases, while no significant benefit is achieved with very large PEGs.

  1. A semiparametric negative binomial generalized linear model for modeling over-dispersed count data with a heavy tail: Characteristics and applications to crash data.

    Science.gov (United States)

    Shirazi, Mohammadali; Lord, Dominique; Dhavala, Soma Sekhar; Geedipally, Srinivas Reddy

    2016-06-01

    Crash data can often be characterized by over-dispersion, heavy (long) tail and many observations with the value zero. Over the last few years, a small number of researchers have started developing and applying novel and innovative multi-parameter models to analyze such data. These multi-parameter models have been proposed for overcoming the limitations of the traditional negative binomial (NB) model, which cannot handle this kind of data efficiently. The research documented in this paper continues the work related to multi-parameter models. The objective of this paper is to document the development and application of a flexible NB generalized linear model with randomly distributed mixed effects characterized by the Dirichlet process (NB-DP) to model crash data. The objective of the study was accomplished using two datasets. The new model was compared to the NB and the recently introduced model based on the mixture of the NB and Lindley (NB-L) distributions. Overall, the research study shows that the NB-DP model offers a better performance than the NB model once data are over-dispersed and have a heavy tail. The NB-DP performed better than the NB-L when the dataset has a heavy tail, but a smaller percentage of zeros. However, both models performed similarly when the dataset contained a large amount of zeros. In addition to a greater flexibility, the NB-DP provides a clustering by-product that allows the safety analyst to better understand the characteristics of the data, such as the identification of outliers and sources of dispersion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Non-linear feeding functional responses in the Greater Flamingo (Phoenicopterus roseus) predict immediate negative impact of wetland degradation on this flagship species

    Science.gov (United States)

    Deville, Anne-Sophie; Grémillet, David; Gauthier-Clerc, Michel; Guillemain, Matthieu; Von Houwald, Friederike; Gardelli, Bruno; Béchet, Arnaud

    2013-01-01

    Accurate knowledge of the functional response of predators to prey density is essential for understanding food web dynamics, to parameterize mechanistic models of animal responses to environmental change, and for designing appropriate conservation measures. Greater flamingos (Phoenicopterus roseus), a flagship species of Mediterranean wetlands, primarily feed on Artemias (Artemia spp.) in commercial salt pans, an industry which may collapse for economic reasons. Flamingos also feed on alternative prey such as Chironomid larvae (e.g., Chironomid spp.) and rice seeds (Oryza sativa). However, the profitability of these food items for flamingos remains unknown. We determined the functional responses of flamingos feeding on Artemias, Chironomids, or rice. Experiments were conducted on 11 captive flamingos. For each food item, we offered different ranges of food densities, up to 13 times natural abundance. Video footage allowed estimating intake rates. Contrary to theoretical predictions for filter feeders, intake rates did not increase linearly with increasing food density (type I). Intake rates rather increased asymptotically with increasing food density (type II) or followed a sigmoid shape (type III). Hence, flamingos were not able to ingest food in direct proportion to their abundance, possibly because of unique bill structure resulting in limited filtering capabilities. Overall, flamingos foraged more efficiently on Artemias. When feeding on Chironomids, birds had lower instantaneous rates of food discovery and required more time to extract food from the sediment and ingest it, than when filtering Artemias from the water column. However, feeding on rice was energetically more profitable for flamingos than feeding on Artemias or Chironomids, explaining their attraction for rice fields. Crucially, we found that food densities required for flamingos to reach asymptotic intake rates are rarely met under natural conditions. This allows us to predict an immediate

  3. Sunitinib significantly suppresses the proliferation, migration, apoptosis resistance, tumor angiogenesis and growth of triple-negative breast cancers but increases breast cancer stem cells.

    Science.gov (United States)

    Chinchar, Edmund; Makey, Kristina L; Gibson, John; Chen, Fang; Cole, Shelby A; Megason, Gail C; Vijayakumar, Srinivassan; Miele, Lucio; Gu, Jian-Wei

    2014-01-01

    The majority of triple-negative breast cancers (TNBCs) are basal-like breast cancers. However there is no reported study on anti-tumor effects of sunitinib in xenografts of basal-like TNBC (MDA-MB-468) cells. In the present study, MDA-MB-231, MDA-MB-468, MCF-7 cells were cultured using RPMI 1640 media with 10% FBS. Vascular endothelia growth factor (VEGF) protein levels were detected using ELISA (R & D Systams). MDA-MB-468 cells were exposed to sunitinib for 18 hours for measuring proliferation (3H-thymidine incorporation), migration (BD Invasion Chamber), and apoptosis (ApopTag and ApoScreen Anuexin V Kit). The effect of sunitinib on Notch-1 expression was determined by Western blot in cultured MDA-MB-468 cells. 10(6) MDA-MB-468 cells were inoculated into the left fourth mammary gland fat pad in athymic nude-foxn1 mice. When the tumor volume reached 100 mm(3), sunitinib was given by gavage at 80 mg/kg/2 days for 4 weeks. Tumor angiogenesis was determined by CD31 immunohistochemistry. Breast cancer stem cells (CSCs) isolated from the tumors were determined by flow cytometry analysis using CD44(+)/CD24(-) or low. ELISA indicated that VEGF was much more highly expressed in MDA-MB-468 cells than MDA-MB-231 and MCF-7 cells. Sunitinib significantly inhibited the proliferation, invasion, and apoptosis resistance in cultured basal like breast cancer cells. Sunitinib significantly increased the expression of Notch-1 protein in cultured MDA-MB-468 or MDA-MB-231 cells. The xenograft models showed that oral sunitinib significantly reduced the tumor volume of TNBCs in association with the inhibition of tumor angiogeneisis, but increased breast CSCs. These findings support the hypothesis that the possibility should be considered of sunitinib increasing breast CSCs though it inhibits TNBC tumor angiogenesis and growth/progression, and that effects of sunitinib on Notch expression and hypoxia may increase breast cancer stem cells. This work provides the groundwork for an

  4. Clinical significance of spasmolytic polypeptide-expressing metaplasia and intestinal metaplasia in Epstein-Barr virus-associated and Epstein-Barr virus-negative gastric cancer.

    Science.gov (United States)

    Zhang, Yu; Chen, Jian-Ning; Dong, Min; Zhang, Zhi-Gang; Zhang, Yi-Wang; Wu, Jun-Yan; Du, Hong; Li, Hai-Gang; Huang, Yan; Shao, Chun-Kui

    2017-05-01

    Spasmolytic polypeptide-expressing metaplasia (SPEM) and intestinal metaplasia (IM) have been recognized as neoplastic precursors in gastric carcinogenesis. We explored the relationship between SPEM and IM in Epstein-Barr virus-associated (EBVaGC) and Epstein-Barr virus-negative (EBVnGC) gastric cancer. Sixty-four EBVaGC and one hundred and fifty-four EBVnGC patients were included. EBV positivity was identified using Epstein-Barr virus-encoded RNA-1 in situ hybridization. SPEM was subclassified into absent, early, and advanced SPEM. Acute and chronic inflammation was graded as absent, mild, moderate, and marked. Univariate and multivariate logistic regression analyses were conducted to analyze the correlation between SPEM, IM, and inflammation. Our study revealed that SPEM was detected in 87.5% EBVaGC and 85.1% EBVnGC patients. Distribution of patients according to the SPEM classification was significantly different between EBVaGC and EBVnGC groups (P=.038). IM was observed less frequently in EBVaGC when compared with EBVnGC patients (P<.001). No difference was observed between EBVaGC and EBVnGC in the levels of acute and chronic inflammation. A positive correlation between IM and SPEM status was observed in both EBVaGC and EBVnGC patients. Furthermore, advanced SPEM was an independent influential factor to IM in EBVnGC (P=.013). In conclusion, SPEM was associated with both EBVaGC and EBVnGC more frequently than IM. Moreover, advanced SPEM had a stronger association with IM than early SPEM in EBVnGC. These results suggest that identification of SPEM should be used as a high-risk indicator for detecting early gastric carcinoma, and should be brought to the attention of pathologists and clinicians. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Significant role of Fas ligand-binding but defective Fas receptor (CD95) in lymph node hyperplasia composed of abnormal double-negative T cells

    Science.gov (United States)

    Matsuzawa, Akio; Shimizu, Motomu; Takeda, Yasutaka; Nagase, Hisashi; Sayama, Kazutoshi; Kimura, Mikio

    2002-01-01

    The functional differences between two mutations of the Fas (CD95) locus, Faslpr (lpr) and Faslprcg (lprcg), were investigated using bone marrow (BM) transplantation on the C3H mouse background. Both lpr/lpr and lprcg/lprcg BM transferred caused lymph node (LN) hyperplasia in lpr/+ and lprcg/+ recipients, although it was clearly smaller than that in lpr/lpr and lprcg/lprcg recipients of lpr/lpr and lprcg/lprcg BM. In addition, both BM induced significantly larger LN hyperplasia in lprcg/+ than lpr/+ recipients. Appearance of CD4− CD8−[double negative (DN)] T cells in the periphery is the most consistent phenotype of Fas mutations. Importantly, the proportion of DN T cells was higher in larger LN hyperplasia in the order of lpr/+, lprcg/+ and lpr/lpr or lprcg/lprcg recipients. On the other hand, both lpr/lpr and lprcg/lprcg BM transferred into wild-type (+/+) mice caused marked LN atrophy. The former, but not the latter, induced wasting syndrome. Faslg1d (gld)-homozygous lpr/lpr BM transferred into +/+ mice elicited LN hyperplasia of the same extent as that in lpr/lpr mice transferred with lpr/lpr BM, but not wasting syndrome. Taken together with the fact that DN T cells massively express Fas ligand (FasL), this study implied that FasL overexpressed on DN cells may be involved in the accumulation of DN T cells in LN, LN atrophy and wasting syndrome, and that lprcg Fas, which can bind to Fas ligand but not transduce apoptosis signal into cells, may modulate these pathological conditions by interfering with the binding of FasL to Fas. PMID:12153509

  6. Critical significance of the region between Helix 1 and 2 for efficient dominant-negative inhibition by conversion-incompetent prion protein.

    Directory of Open Access Journals (Sweden)

    Yuzuru Taguchi

    Full Text Available Prion diseases are fatal infectious neurodegenerative disorders in man and animals associated with the accumulation of the pathogenic isoform PrP(Sc of the host-encoded prion protein (PrP(c. A profound conformational change of PrP(c underlies formation of PrP(Sc and prion propagation involves conversion of PrP(c substrate by direct interaction with PrP(Sc template. Identifying the interfaces and modalities of inter-molecular interactions of PrPs will highly advance our understanding of prion propagation in particular and of prion-like mechanisms in general. To identify the region critical for inter-molecular interactions of PrP, we exploited here dominant-negative inhibition (DNI effects of conversion-incompetent, internally-deleted PrP (ΔPrP on co-expressed conversion-competent PrP. We created a series of ΔPrPs with different lengths of deletions in the region between first and second α-helix (H1∼H2 which was recently postulated to be of importance in prion species barrier and PrP fibril formation. As previously reported, ΔPrPs uniformly exhibited aberrant properties including detergent insolubility, limited protease digestion resistance, high-mannose type N-linked glycans, and intracellular localization. Although formerly controversial, we demonstrate here that ΔPrPs have a GPI anchor attached. Surprisingly, despite very similar biochemical and cell-biological properties, DNI efficiencies of ΔPrPs varied significantly, dependant on location and inversely correlated with the size of deletion. This data demonstrates that H1∼H2 and the region C-terminal to it are critically important for efficient DNI. It also suggests that this region is involved in PrP-PrP interaction and conversion of PrP(C into PrP(Sc. To reconcile the paradox of how an intracellular PrP can exert DNI, we demonstrate that ΔPrPs are subject to both proteasomal and lysosomal/autophagic degradation pathways. Using autophagy pathways ΔPrPs obtain access to the locale

  7. Lack of clinical AIDS in SIV-infected sooty mangabeys with significant CD4+ T cell loss is associated with double-negative T cells

    Science.gov (United States)

    Milush, Jeffrey M.; Mir, Kiran D.; Sundaravaradan, Vasudha; Gordon, Shari N.; Engram, Jessica; Cano, Christopher A.; Reeves, Jacqueline D.; Anton, Elizabeth; O’Neill, Eduardo; Butler, Eboneé; Hancock, Kathy; Cole, Kelly S.; Brenchley, Jason M.; Else, James G.; Silvestri, Guido; Sodora, Donald L.

    2011-01-01

    SIV infection of natural host species such as sooty mangabeys results in high viral replication without clinical signs of simian AIDS. Studying such infections is useful for identifying immunologic parameters that lead to AIDS in HIV-infected patients. Here we have demonstrated that acute, SIV-induced CD4+ T cell depletion in sooty mangabeys does not result in immune dysfunction and progression to simian AIDS and that a population of CD3+CD4–CD8– T cells (double-negative T cells) partially compensates for CD4+ T cell function in these animals. Passaging plasma from an SIV-infected sooty mangabey with very few CD4+ T cells to SIV-negative animals resulted in rapid loss of CD4+ T cells. Nonetheless, all sooty mangabeys generated SIV-specific antibody and T cell responses and maintained normal levels of plasma lipopolysaccharide. Moreover, all CD4-low sooty mangabeys elicited a de novo immune response following influenza vaccination. Such preserved immune responses as well as the low levels of immune activation observed in these animals were associated with the presence of double-negative T cells capable of producing Th1, Th2, and Th17 cytokines. These studies indicate that SIV-infected sooty mangabeys do not appear to rely entirely on CD4+ T cells to maintain immunity and identify double-negative T cells as a potential subset of cells capable of performing CD4+ T cell–like helper functions upon SIV-induced CD4+ T cell depletion in this species. PMID:21317533

  8. Linearization Method and Linear Complexity

    Science.gov (United States)

    Tanaka, Hidema

    We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.

  9. Variable temperature ion trap studies of CH4+ + H2, HD and D2: negative temperature dependence and significant isotope effect

    International Nuclear Information System (INIS)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D.

    2004-01-01

    Reactions of methane cations, CH 4 + , with H 2 , HD and D 2 have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH 5 + in collisions with H 2 is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH 4 + with HD, the CH 5 + product ion (68% at 15 K) prevails over CH 4 D + (32%). Reaction of CH 4 + with D 2 is found to be much slower than with H 2 or HD. The rate coefficient for converting CH 4 + into CH 3 D + by H-D exchange has been determined to be smaller than 10 -12 cm 3 /s, indicating that scrambling in the CH 6 + complex is very unlikely

  10. Elevated endogenous expression of the dominant negative basic helix-loop-helix protein ID1 correlates with significant centrosome abnormalities in human tumor cells

    Directory of Open Access Journals (Sweden)

    Gutmann Anja

    2010-01-01

    Full Text Available Abstract Background ID proteins are dominant negative inhibitors of basic helix-loop-helix transcription factors that have multiple functions during development and cellular differentiation. Ectopic (over-expression of ID1 extends the lifespan of primary human epithelial cells. High expression levels of ID1 have been detected in multiple human malignancies, and in some have been correlated with unfavorable clinical prognosis. ID1 protein is localized at the centrosomes and forced (over-expression of ID1 results in errors during centrosome duplication. Results Here we analyzed the steady state expression levels of the four ID-proteins in 18 tumor cell lines and assessed the number of centrosome abnormalities. While expression of ID1, ID2, and ID3 was detected, we failed to detect protein expression of ID4. Expression of ID1 correlated with increased supernumerary centrosomes in most cell lines analyzed. Conclusions This is the first report that shows that not only ectopic expression in tissue culture but endogenous levels of ID1 modulate centrosome numbers. Thus, our findings support the hypothesis that ID1 interferes with centrosome homeostasis, most likely contributing to genomic instability and associated tumor aggressiveness.

  11. Variable temperature ion trap studies of CH{sub 4}{sup +} + H{sub 2}, HD and D{sub 2}: negative temperature dependence and significant isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D

    2004-03-08

    Reactions of methane cations, CH{sub 4}{sup +}, with H{sub 2}, HD and D{sub 2} have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH{sub 5}{sup +} in collisions with H{sub 2} is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH{sub 4}{sup +} with HD, the CH{sub 5}{sup +} product ion (68% at 15 K) prevails over CH{sub 4}D{sup +} (32%). Reaction of CH{sub 4}{sup +} with D{sub 2} is found to be much slower than with H{sub 2} or HD. The rate coefficient for converting CH{sub 4}{sup +} into CH{sub 3}D{sup +} by H-D exchange has been determined to be smaller than 10{sup -12} cm{sup 3}/s, indicating that scrambling in the CH{sub 6}{sup +} complex is very unlikely.

  12. A combined stretching-tilting mechanism produces negative, zero and positive linear thermal expansion in a semi-flexible Cd(II)-MOF.

    Science.gov (United States)

    Lama, Prem; Das, Raj Kumar; Smith, Vincent J; Barbour, Leonard J

    2014-06-21

    A novel semi-flexible Cd(II)-MOF has been synthesized and characterized by variable temperature powder and single-crystal X-ray diffraction. The material displays an unusual combination of thermal expansion (TE) i.e. negative, zero and positive, which is an extremely rare finding, especially for metal-organic frameworks as a result of a combined stretching-tilting mechanism.

  13. Impact of age on the false negative rate of human papillomavirus DNA test in patients with atypical squamous cells of undetermined significance

    OpenAIRE

    Won, Kyu-Hee; Lee, Jae Yeon; Cho, Hye-Yon; Suh, Dong Hoon; No, Jae Hong; Kim, Yong-Beom

    2015-01-01

    Objective Human papillomavirus (HPV) test was incorporated into the triage of lesser abnormal cervical cytologies: atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL). This study aimed to evaluate the impact of age on the efficacy of HPV testing in patients with lesser abnormal cervical cytologies. Methods A total of 439 patients with ASCUS or LSIL were included. The association between age groups and the diagnostic performances of ...

  14. Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: Significance of hepatitis B core antibodies screening

    International Nuclear Information System (INIS)

    Elbedewy, T.A.; Elashtokhy, H.A.; Rabee, E.S.; Kheder, G.E.

    2015-01-01

    Background: Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies. Aim of the work: To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy. Patients and methods: This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR). Results: Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation. Conclusion: The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

  15. Magnetic field cycling effect on the non-linear current-voltage characteristics and magnetic field induced negative differential resistance in α-Fe1.64Ga0.36O3 oxide

    Science.gov (United States)

    Bhowmik, R. N.; Vijayasri, G.

    2015-06-01

    We have studied current-voltage (I-V) characteristics of α-Fe1.64Ga0.36O3, a typical canted ferromagnetic semiconductor. The sample showed a transformation of the I-V curves from linear to non-linear character with the increase of bias voltage. The I-V curves showed irreversible features with hysteresis loop and bi-stable electronic states for up and down modes of voltage sweep. We report positive magnetoresistance and magnetic field induced negative differential resistance as the first time observed phenomena in metal doped hematite system. The magnitudes of critical voltage at which I-V curve showed peak and corresponding peak current are affected by magnetic field cycling. The shift of the peak voltage with magnetic field showed a step-wise jump between two discrete voltage levels with least gap (ΔVP) 0.345(± 0.001) V. The magnetic spin dependent electronic charge transport in this new class of magnetic semiconductor opens a wide scope for tuning large electroresistance (˜500-700%), magnetoresistance (70-135 %) and charge-spin dependent conductivity under suitable control of electric and magnetic fields. The electric and magnetic field controlled charge-spin transport is interesting for applications of the magnetic materials in spintronics, e.g., magnetic sensor, memory devices and digital switching.

  16. Magnetic field cycling effect on the non-linear current-voltage characteristics and magnetic field induced negative differential resistance in α-Fe{sub 1.64}Ga{sub 0.36}O{sub 3} oxide

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, R. N., E-mail: rnbhowmik.phy@pondiuni.edu.in; Vijayasri, G. [Department of Physics, Pondicherry University, R.Venkataraman Nagar, Kalapet, Puducherry - 605 014 (India)

    2015-06-15

    We have studied current-voltage (I-V) characteristics of α-Fe{sub 1.64}Ga{sub 0.36}O{sub 3}, a typical canted ferromagnetic semiconductor. The sample showed a transformation of the I-V curves from linear to non-linear character with the increase of bias voltage. The I-V curves showed irreversible features with hysteresis loop and bi-stable electronic states for up and down modes of voltage sweep. We report positive magnetoresistance and magnetic field induced negative differential resistance as the first time observed phenomena in metal doped hematite system. The magnitudes of critical voltage at which I-V curve showed peak and corresponding peak current are affected by magnetic field cycling. The shift of the peak voltage with magnetic field showed a step-wise jump between two discrete voltage levels with least gap (ΔV{sub P}) 0.345(± 0.001) V. The magnetic spin dependent electronic charge transport in this new class of magnetic semiconductor opens a wide scope for tuning large electroresistance (∼500-700%), magnetoresistance (70-135 %) and charge-spin dependent conductivity under suitable control of electric and magnetic fields. The electric and magnetic field controlled charge-spin transport is interesting for applications of the magnetic materials in spintronics, e.g., magnetic sensor, memory devices and digital switching.

  17. Magnetic field cycling effect on the non-linear current-voltage characteristics and magnetic field induced negative differential resistance in α-Fe1.64Ga0.36O3 oxide

    Directory of Open Access Journals (Sweden)

    R. N. Bhowmik

    2015-06-01

    Full Text Available We have studied current-voltage (I-V characteristics of α-Fe1.64Ga0.36O3, a typical canted ferromagnetic semiconductor. The sample showed a transformation of the I-V curves from linear to non-linear character with the increase of bias voltage. The I-V curves showed irreversible features with hysteresis loop and bi-stable electronic states for up and down modes of voltage sweep. We report positive magnetoresistance and magnetic field induced negative differential resistance as the first time observed phenomena in metal doped hematite system. The magnitudes of critical voltage at which I-V curve showed peak and corresponding peak current are affected by magnetic field cycling. The shift of the peak voltage with magnetic field showed a step-wise jump between two discrete voltage levels with least gap (ΔVP 0.345(± 0.001 V. The magnetic spin dependent electronic charge transport in this new class of magnetic semiconductor opens a wide scope for tuning large electroresistance (∼500-700%, magnetoresistance (70-135 % and charge-spin dependent conductivity under suitable control of electric and magnetic fields. The electric and magnetic field controlled charge-spin transport is interesting for applications of the magnetic materials in spintronics, e.g., magnetic sensor, memory devices and digital switching.

  18. Complementary Feeding Interventions Have a Small but Significant Impact on Linear and Ponderal Growth of Children in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Panjwani, Anita; Heidkamp, Rebecca

    2017-11-01

    Background: World Health Assembly member states have committed to ambitious global targets for reductions in stunting and wasting by 2025. Improving complementary diets of children aged 6-23 mo is a recommended approach for reducing stunting in children impact of complementary feeding interventions on linear [length-for-age z score (LAZ)] and ponderal [weight-for-length z score (WLZ)] growth of children aged 6-23 mo, with the specific goal of updating intervention-outcome linkages in the Lives Saved Tool (LiST). Methods: We started our review with studies included in the previous LiST review and searched for articles published since January 2012. We identified longitudinal trials that compared children aged 6-23 mo who received 1 of 2 types of complementary feeding interventions (nutrition education or counseling alone or complementary food supplementation with or without nutrition education or counseling) with a no-intervention control. We assessed study quality and generated pooled estimates of LAZ and WLZ change, as well as length and weight gain, for each category of intervention. Results: Interventions that provided nutrition education or counseling had a small but significant impact on linear growth in food-secure populations [LAZ standardized mean difference (SMD): 0.11; 95% CI: 0.01, 0.22] but not on ponderal growth. Complementary food supplementation interventions with or without nutrition education also had a small, significant effect in food-insecure settings on both LAZ (SMD: 0.08; 95% CI: 0.04, 0.13) and WLZ (SMD: 0.05; 95% CI: 0.01, 0.08). Conclusions: Nutrition education and complementary feeding interventions both had a small but significant impact on linear growth, and complementary feeding interventions also had an impact on ponderal growth of children aged 6-23 mo in low- and middle-income countries. The updated LiST model will support nutrition program planning and evaluation efforts by allowing users to model changes in intervention coverage on

  19. Linear algebra

    CERN Document Server

    Shilov, Georgi E

    1977-01-01

    Covers determinants, linear spaces, systems of linear equations, linear functions of a vector argument, coordinate transformations, the canonical form of the matrix of a linear operator, bilinear and quadratic forms, Euclidean spaces, unitary spaces, quadratic forms in Euclidean and unitary spaces, finite-dimensional space. Problems with hints and answers.

  20. Significant reduction of peripheral blood interleukin-35 and CD4+EBI3+ T cells, which are negatively correlated with an increase in the plasma IL-17 and cTnI level, in viral myocarditis patients

    Directory of Open Access Journals (Sweden)

    Han Ouyang

    2017-02-01

    Full Text Available Introduction: Viral myocarditis (VMC has become an increasingly common heart disease that endangers human health. In the present study, the plasma interleukin-35 (IL-35 level and the percentage of CD4 + EBI3 + T cells in VMC patients were detected to investigate the significance of changes in these parameters in the plasma of VMC patients and their association with the disease. Material and methods: ELISA was performed to detect the plasma IL-35 level and the percentage of peripheral blood CD4 + EBI3 + T cells in 40 VMC patients and in 20 healthy individuals. Moreover, the plasma IL-17 levels in the VMC patients and in the healthy individuals were detected using an ELISA, and the cardiac Troponin-I (cTnI levels were detected using a chemiluminescent microparticle immunoassay to compare the differences in the groups. Results : Plasma IL-35 level and the percentage of CD4 + EBI3 + T cells in acute phase VMC patients was lower than that in the healthy control group and the convalescent phase VMC patients. Additionally, the plasma IL-35 level in the VMC patients exhibited a negative correlation with the levels of cTnI and IL-17. The percentage of CD4 + EBI3 + T cells also showed a negative correlation with the levels of cTnI and IL-17. Conclusions : The plasma IL-35 level and the percentage of CD4 + EBI3 + T cells in VMC patients was reduced, and the amount of the decrease was associated with the severity of the disease. These results suggest that IL-35 and CD4 + EBI3 + T might play important roles in the progression of VMC and could be used as indictors of the disease.

  1. When negation is not negation

    OpenAIRE

    Milicevic, Nataša

    2008-01-01

    In this paper I will discuss the formation of different types of yes/no questions in Serbian (examples in (1)), focusing on the syntactically and semantically puzzling example (1d), which involves the negative auxiliary inversion. Although there is a negative marker on the fronted auxiliary, the construction does not involve sentential negation. This coincides with the fact that the negative quantifying NPIs cannot be licensed. The question formation and sentential negation have similar synta...

  2. Linear Accelerators

    International Nuclear Information System (INIS)

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics

  3. Negative mass

    International Nuclear Information System (INIS)

    Hammond, Richard T

    2015-01-01

    Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given. (paper)

  4. linear-quadratic-linear model

    Directory of Open Access Journals (Sweden)

    Tanwiwat Jaikuna

    2017-02-01

    Full Text Available Purpose: To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL model. Material and methods : The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR, and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD2 was calculated using biological effective dose (BED based on the LQL model. The software calculation and the manual calculation were compared for EQD2 verification with pair t-test statistical analysis using IBM SPSS Statistics version 22 (64-bit. Results: Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV determined by D90%, 0.56% in the bladder, 1.74% in the rectum when determined by D2cc, and less than 1% in Pinnacle. The difference in the EQD2 between the software calculation and the manual calculation was not significantly different with 0.00% at p-values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT and 0.240, 0.320, and 0.849 for brachytherapy (BT in HR-CTV, bladder, and rectum, respectively. Conclusions : The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.

  5. Linear algebra

    CERN Document Server

    Said-Houari, Belkacem

    2017-01-01

    This self-contained, clearly written textbook on linear algebra is easily accessible for students. It begins with the simple linear equation and generalizes several notions from this equation for the system of linear equations and introduces the main ideas using matrices. It then offers a detailed chapter on determinants and introduces the main ideas with detailed proofs. The third chapter introduces the Euclidean spaces using very simple geometric ideas and discusses various major inequalities and identities. These ideas offer a solid basis for understanding general Hilbert spaces in functional analysis. The following two chapters address general vector spaces, including some rigorous proofs to all the main results, and linear transformation: areas that are ignored or are poorly explained in many textbooks. Chapter 6 introduces the idea of matrices using linear transformation, which is easier to understand than the usual theory of matrices approach. The final two chapters are more advanced, introducing t...

  6. Negative Leadership

    Science.gov (United States)

    2013-03-01

    Negative Leadership by Colonel David M. Oberlander United States Army United States Army War...SUBTITLE Negative Leadership 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Colonel David M...Dr. Richard C. Bullis Department of Command Leadership , and Management 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING

  7. Negative liability

    NARCIS (Netherlands)

    Dari-Mattiacci, G.

    2009-01-01

    Negative and positive externalities pose symmetrical problems to social welfare. The law internalizes negative externalities by providing general tort liability rules. According to such rules, those who cause harm to others should pay compensation. In theory, in the presence of positive

  8. Negative ... concord?

    NARCIS (Netherlands)

    Giannakidou, A

    The main claim of this paper is that a general theory of negative concord (NC) should allow for the possibility of NC involving scoping of a universal quantifier above negation. I propose that Greek NC instantiates this option. Greek n-words will be analyzed as polarity sensitive universal

  9. Significância clínica de estafilococos coagulase-negativa isolados de recém-nascidos Clinical significance of coagulase-negative staphylococci isolated from neonates

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes R.S. Cunha

    2002-01-01

    Full Text Available Objetivo: avaliar a significância clínica de estafilococos coagulase-negativa (ECN isolados de processos infecciosos em recém-nascidos da unidade neonatal do Hospital das Clínicas da Faculdade de Medicina de Botucatu. Método: as linhagens de ECN isoladas foram identificadas e classificadas em significativas e contaminantes, com base em uma série de dados clínicos e laboratoriais obtidos dos prontuários dos pacientes internados na unidade neonatal. Foram pesquisados os dados referentes a fatores perinatais de risco para infecção, evolução clínica, alterações do hemograma e/ou positividade de proteína C-reativa e antibioticoterapia. Resultados: das 117 linhagens de ECN isoladas, 60 (51,3% foram classificadas como significativas, e 57 (48,7% como contaminantes. Das 54 crianças com infecção por ECN, 43 (79,6% eram prematuras, e 27 (50,0% tiveram peso ao nascimento Conclusões: a maioria dos recém-nascidos com infecção por ECN apresentou fatores predisponentes importantes para a instalação do processo infeccioso, incluindo o peso de nascimento Objective: to evaluate the clinical significance of coagulase-negative staphylococci (CNS isolated from newborns’ infections at Neonatal Unit of Hospital das Clínicas da Faculdade de Medicina de Botucatu. Methods: the CNS strains isolated were identified and classified as clinically significant and contaminant, based on a series of clinical and laboratory data obtained from patients who stayed in the Neonatal Unit. The following data were analyzed: risk factors for infections, clinical evolution, abnormal blood cell counts and/or C-reactive protein e antibiotic therapy. Results: among the 117 CNS strains isolated, 60 (51.3% were classified as significant and 57 (48.7% as contaminant. Among the 54 infants infected by CNS, 43 (79.6% presented very low birthweight (< 1,500g. Most of the infants infected by CNS were submitted to two or more invasive procedures (77.8%, including use of

  10. Expression of HIF-1α and Markers of Angiogenesis Are Not Significantly Different in Triple Negative Breast Cancer Compared to Other Breast Cancer Molecular Subtypes: Implications for Future Therapy.

    Science.gov (United States)

    Yehia, Lamis; Boulos, Fouad; Jabbour, Mark; Mahfoud, Ziyad; Fakhruddin, Najla; El-Sabban, Marwan

    2015-01-01

    Triple negative breast cancer lacks estrogen, progesterone and epidermal growth factor receptors rendering it refractory to available targetedtherapies. TNBC is associated with central fibrosis and necrosis, both indicators of tumor hypoxia. Hypoxia inducible factor 1α is up-regulated under hypoxia and its expression is associated with induction of angiogenesis resulting in proliferation, aggressive tumor phenotype and metastasis. In this study we evaluate the potential use of HIF-1α as aTNBC-specific marker. 62 TNBC, 64 HER2+, and 64 hormone-receptors positive breast cancer cases were evaluated for central fibrosis and necrosis, HIF-1α, HIF-1β, VEGFR3, CD31 expression and microvessel density. RNA extraction from paraffin-embedded samples, followed by quantitative real-time polymerase chain reaction (qRT-PCR) evaluation of HIF-1α and VEGF transcripts was performed on 54 cases (18 from each subtype). HIF-1α protein was expressed in 35.5% TNBC, 45.3% HER2+and 25.0% ER+/PR+ (p = 0.055; χ2 test). PCRanalysis of subgroup of breast cancers, 84.2% expressed HIF-1α protein and its transcripts, while only 66.7% expressed VEGF transcripts simultaneously with the HIF-1α protein and its transcripts. Central fibrosis and necrosis was highest in TNBC (p = 0.015; χ2 test), while MVD was comparable among all groups (p = 0.928; χ2 test). VEGFR3 was highest in TNBC expressing HIF-1α. HIF-1β protein was expressed in 32.0% of HIF-1α(+), and in (44.3%) of HIF-1α(-) breast cancer cases (p = 0.033; χ2 test). Moreover, HIF-1α expression in cases with central fibrosis and necrosis was highest in the HER2+ followed by the TNBC (p = 0.156; χ2 test). A proportion of TNBC express HIF-1α but not in a significantly different manner from other breast cancer subtypes. The potential of anti-HIF-1α targeted therapy is therefore not a candidate for exclusive use in TNBC, but should be considered in all breast cancers, especially in the setting of clinically aggressive or

  11. Linear algebra

    CERN Document Server

    Stoll, R R

    1968-01-01

    Linear Algebra is intended to be used as a text for a one-semester course in linear algebra at the undergraduate level. The treatment of the subject will be both useful to students of mathematics and those interested primarily in applications of the theory. The major prerequisite for mastering the material is the readiness of the student to reason abstractly. Specifically, this calls for an understanding of the fact that axioms are assumptions and that theorems are logical consequences of one or more axioms. Familiarity with calculus and linear differential equations is required for understand

  12. Linear programming

    CERN Document Server

    Solow, Daniel

    2014-01-01

    This text covers the basic theory and computation for a first course in linear programming, including substantial material on mathematical proof techniques and sophisticated computation methods. Includes Appendix on using Excel. 1984 edition.

  13. Linear algebra

    CERN Document Server

    Liesen, Jörg

    2015-01-01

    This self-contained textbook takes a matrix-oriented approach to linear algebra and presents a complete theory, including all details and proofs, culminating in the Jordan canonical form and its proof. Throughout the development, the applicability of the results is highlighted. Additionally, the book presents special topics from applied linear algebra including matrix functions, the singular value decomposition, the Kronecker product and linear matrix equations. The matrix-oriented approach to linear algebra leads to a better intuition and a deeper understanding of the abstract concepts, and therefore simplifies their use in real world applications. Some of these applications are presented in detailed examples. In several ‘MATLAB-Minutes’ students can comprehend the concepts and results using computational experiments. Necessary basics for the use of MATLAB are presented in a short introduction. Students can also actively work with the material and practice their mathematical skills in more than 300 exerc...

  14. Linear algebra

    CERN Document Server

    Berberian, Sterling K

    2014-01-01

    Introductory treatment covers basic theory of vector spaces and linear maps - dimension, determinants, eigenvalues, and eigenvectors - plus more advanced topics such as the study of canonical forms for matrices. 1992 edition.

  15. Linear Models

    CERN Document Server

    Searle, Shayle R

    2012-01-01

    This 1971 classic on linear models is once again available--as a Wiley Classics Library Edition. It features material that can be understood by any statistician who understands matrix algebra and basic statistical methods.

  16. LINEAR ACCELERATOR

    Science.gov (United States)

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  17. Does removal of mammalian predators significantly affect success of simulated nests in linear habitats? Case study on American mink Mustela vison \\& Predation on simulated duck nests in relation to nest density and habitat type

    OpenAIRE

    PADYŠÁKOVÁ, Eliška

    2007-01-01

    This thesis is made up of two studies dealing with predation of waterfowl nests. in the first study, we determined wheather removal of introduced predator Mustela vison affected nest survival of simulated duck nests in linear habitat. In the second study, we tested two hypothesis: 1)predation depends on density of waterfowl nests, 2)mammals are main predators in forest habitat and birds mainly depredate nests deployed in open land.

  18. Linear collider: a preview

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, H.

    1981-11-01

    Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

  19. Linear collider: a preview

    International Nuclear Information System (INIS)

    Wiedemann, H.

    1981-11-01

    Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center

  20. Linear regression

    CERN Document Server

    Olive, David J

    2017-01-01

    This text covers both multiple linear regression and some experimental design models. The text uses the response plot to visualize the model and to detect outliers, does not assume that the error distribution has a known parametric distribution, develops prediction intervals that work when the error distribution is unknown, suggests bootstrap hypothesis tests that may be useful for inference after variable selection, and develops prediction regions and large sample theory for the multivariate linear regression model that has m response variables. A relationship between multivariate prediction regions and confidence regions provides a simple way to bootstrap confidence regions. These confidence regions often provide a practical method for testing hypotheses. There is also a chapter on generalized linear models and generalized additive models. There are many R functions to produce response and residual plots, to simulate prediction intervals and hypothesis tests, to detect outliers, and to choose response trans...

  1. Linear Colliders

    International Nuclear Information System (INIS)

    Alcaraz, J.

    2001-01-01

    After several years of study e''+ e''- linear colliders in the TeV range have emerged as the major and optimal high-energy physics projects for the post-LHC era. These notes summarize the present status form the main accelerator and detector features to their physics potential. The LHC era. These notes summarize the present status, from the main accelerator and detector features to their physics potential. The LHC is expected to provide first discoveries in the new energy domain, whereas an e''+ e''- linear collider in the 500 GeV-1 TeV will be able to complement it to an unprecedented level of precision in any possible areas: Higgs, signals beyond the SM and electroweak measurements. It is evident that the Linear Collider program will constitute a major step in the understanding of the nature of the new physics beyond the Standard Model. (Author) 22 refs

  2. Linear algebra

    CERN Document Server

    Edwards, Harold M

    1995-01-01

    In his new undergraduate textbook, Harold M Edwards proposes a radically new and thoroughly algorithmic approach to linear algebra Originally inspired by the constructive philosophy of mathematics championed in the 19th century by Leopold Kronecker, the approach is well suited to students in the computer-dominated late 20th century Each proof is an algorithm described in English that can be translated into the computer language the class is using and put to work solving problems and generating new examples, making the study of linear algebra a truly interactive experience Designed for a one-semester course, this text adopts an algorithmic approach to linear algebra giving the student many examples to work through and copious exercises to test their skills and extend their knowledge of the subject Students at all levels will find much interactive instruction in this text while teachers will find stimulating examples and methods of approach to the subject

  3. The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women.

    Science.gov (United States)

    Jespers, Vicky; van de Wijgert, Janneke; Cools, Piet; Verhelst, Rita; Verstraelen, Hans; Delany-Moretlwe, Sinead; Mwaura, Mary; Ndayisaba, Gilles F; Mandaliya, Kishor; Menten, Joris; Hardy, Liselotte; Crucitti, Tania

    2015-03-04

    Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known. We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance. The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest G. vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of L. crispatus (studied African countries was similar, the presence of protective species i.e. L. crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively

  4. Negative CO

    NARCIS (Netherlands)

    Meysman, F.J.R.; Montserrat, F.

    2017-01-01

    Negative emission technologies (NETs) target the removal of carbon dioxide (CO2) from the atmosphere, and are being actively investigated as a strategy to limit global warming to within the 1.5–2°C targets of the 2015 UN climate agreement. Enhanced silicate weathering (ESW) proposes to

  5. Negative Certainty

    Science.gov (United States)

    Ariso, José María

    2017-01-01

    The definitions of "negative knowledge" and the studies in this regard published to date have not considered the categorial distinction Wittgenstein established between knowledge and certainty. Hence, the important role that certainty, despite its omission, should have in these definitions and studies has not yet been shown. In this…

  6. Use of genotypic identification by sodA sequencing in a prospective study to examine the distribution of coagulase-negative Staphylococcus species among strains recovered during septic orthopedic surgery and evaluate their significance.

    Science.gov (United States)

    Sivadon, V; Rottman, M; Chaverot, S; Quincampoix, J-C; Avettand, V; de Mazancourt, P; Bernard, L; Trieu-Cuot, P; Féron, J-M; Lortat-Jacob, A; Piriou, P; Judet, T; Gaillard, J-L

    2005-06-01

    A total of 212 coagulase-negative Staphylococcus strains recovered prospectively during 119 surgeries for proven or suspected bone and joint infection (BJI) were identified by sodA sequencing. These strains were identified as 151 Staphylococcus epidermidis isolates, 15 S. warneri isolates, 14 S. capitis isolates, 9 S. hominis isolates, 6 S. lugdunensis isolates, 5 S. haemolyticus isolates, 4 S. caprae isolates, 4 S. pasteuri isolates, 3 S. simulans isolates, and 1 S. cohnii isolate. Only S. epidermidis, S. lugdunensis, S. capitis, and S. caprae were found to be infecting organisms and were involved, respectively, in 35 (81.4%), 3 (7.0%), 3 (7.0%), and 2 (4.6%) cases of BJI.

  7. Linear programming

    CERN Document Server

    Karloff, Howard

    1991-01-01

    To this reviewer’s knowledge, this is the first book accessible to the upper division undergraduate or beginning graduate student that surveys linear programming from the Simplex Method…via the Ellipsoid algorithm to Karmarkar’s algorithm. Moreover, its point of view is algorithmic and thus it provides both a history and a case history of work in complexity theory. The presentation is admirable; Karloff's style is informal (even humorous at times) without sacrificing anything necessary for understanding. Diagrams (including horizontal brackets that group terms) aid in providing clarity. The end-of-chapter notes are helpful...Recommended highly for acquisition, since it is not only a textbook, but can also be used for independent reading and study. —Choice Reviews The reader will be well served by reading the monograph from cover to cover. The author succeeds in providing a concise, readable, understandable introduction to modern linear programming. —Mathematics of Computing This is a textbook intend...

  8. Positive and Negative Peer Influence in Residential Care.

    Science.gov (United States)

    Huefner, Jonathan C; Smith, Gail L; Stevens, Amy L

    2017-10-13

    The potential for negative peer influence has been well established in research, and there is a growing interest in how positive peer influence also impacts youth. No research, however, has concurrently examined positive and negative peer influence in the context of residential care. Clinical records for 886 residential care youth were used in a Hierarchical Linear Model analysis to examine the impact of negative and positive peer influence on naturally occurring patterns of serious problem behavior over time. Negative peer influence, where the majority of youth in a home manifested above the average number of serious behavior problems, occurred 13.7% of the time. Positive peer influence, where the majority of youth manifested no serious problem behaviors for the month, occurred 47.7% of the time. Overall, youth problem behavior improved over time. There were significantly lower rates of serious problem behavior in target youth during positive peer influence months. Conversely, there were significantly higher rates of serious problem behaviors in target youth during negative peer influence months. Negative peer influence had a relatively greater impact on target peers' serious behavior problems than did positive peer influence. Caregiver experience significantly reduced the impact of negative peer influence, but did not significantly augment positive peer influence. Months where negative peer influence was combined with inexperienced caregivers produced the highest rates of serious problem behavior. Our results support the view that residential programs for troubled youth need to create circumstances that promote positive and control for negative peer influence.

  9. Reduction of Linear Programming to Linear Approximation

    OpenAIRE

    Vaserstein, Leonid N.

    2006-01-01

    It is well known that every Chebyshev linear approximation problem can be reduced to a linear program. In this paper we show that conversely every linear program can be reduced to a Chebyshev linear approximation problem.

  10. The value of quantitative parameters of dynamic-enhanced MRI and the significance of the maximum linearity slope ratio in the differential diagnosis of benign and malignant breast lesions

    International Nuclear Information System (INIS)

    Ouyang Yi; Xie Chuanmiao; Wu Yaopan; Lv Yanchun; Ruan Chaomei; Zheng Lie; Peng Kangqiang; He Haoqiang; Chen Lin; Zhang Weizhang

    2008-01-01

    Objective: To find the effective quantitative parameters for the differentiation of the breast lesions using the post-processing of time-signal curve of 3D dynamic-enhanced MRI. Methods: Thirty patients with 35 lesions underwent 3D dynamic-enhanced MRI and the time-signal curve was deduced. The four quantitative parameters including SImax, PH, Slope and Slope R were analyzed in benign and malignant lesions of the breast. Independent samples t test and rank sum test were used for the statistics. Results: Seyenteen benign lesions and 18 malignant lesions were included in this study. The SImax (M) of benign and malignant lesions were 375.2 and 158.1, the 95% confidence intervals of SImax were 278.2- 506. 0 and 160.5--374. 8. The PH (M) of benign and malignant lesions were 114.4 and 87. 8, the 95% confidence intervals of PH were 73.7-196.5 and 71.3-162. 9. The Slope (M) of benign and malignant lesions were 22.3 x 10 -3 and 44.0 x 10 -3 , the 95% confidence intervals of Slope were 13.7 x 10 -3 - 41.1 x 10 -3 and 46.1 x 10 -3 -81.8 x 10 -3 . The Slopea (M) of benign and malignant lesions were 2.6 and 11.4, the 95% confidence intervals of Slopea were 1.9-3.4 and 9.8-14.5. There were no significant differences on SImax and PH between benign and malignant lesions (P>0.05). The significant differences existed on Slope (P<0.01) and Slopea (P <0.01) between benign and malignant lesions of the breast. Conclusion: Slopea is a very effective parameter in the differential diagnosis of breast lesions. (authors)

  11. Functional abilities and cognitive decline in adult and aging intellectual disabilities. Psychometric validation of an Italian version of the Alzheimer's Functional Assessment Tool (AFAST): analysis of its clinical significance with linear statistics and artificial neural networks.

    Science.gov (United States)

    De Vreese, L P; Gomiero, T; Uberti, M; De Bastiani, E; Weger, E; Mantesso, U; Marangoni, A

    2015-04-01

    (a) A psychometric validation of an Italian version of the Alzheimer's Functional Assessment Tool scale (AFAST-I), designed for informant-based assessment of the degree of impairment and of assistance required in seven basic daily activities in adult/elderly people with intellectual disabilities (ID) and (suspected) dementia; (b) a pilot analysis of its clinical significance with traditional statistical procedures and with an artificial neural network. AFAST-I was administered to the professional caregivers of 61 adults/seniors with ID with a mean age (± SD) of 53.4 (± 7.7) years (36% with Down syndrome). Internal consistency (Cronbach's α coefficient), inter/intra-rater reliabilities (intra-class coefficients, ICC) and concurrent, convergent and discriminant validity (Pearson's r coefficients) were computed. Clinical significance was probed by analysing the relationships among AFAST-I scores and the Sum of Cognitive Scores (SCS) and the Sum of Social Scores (SOS) of the Dementia Questionnaire for Persons with Intellectual Disabilities (DMR-I) after standardisation of their raw scores in equivalent scores (ES). An adaptive artificial system (AutoContractive Maps, AutoCM) was applied to all the variables recorded in the study sample, aimed at uncovering which variable occupies a central position and supports the entire network made up of the remaining variables interconnected among themselves with different weights. AFAST-I shows a high level of internal homogeneity with a Cronbach's α coefficient of 0.92. Inter-rater and intra-rater reliabilities were also excellent with ICC correlations of 0.96 and 0.93, respectively. The results of the analyses of the different AFAST-I validities all go in the expected direction: concurrent validity (r=-0.87 with ADL); convergent validity (r=0.63 with SCS; r=0.61 with SOS); discriminant validity (r=0.21 with the frequency of occurrence of dementia-related Behavioral Excesses of the Assessment for Adults with Developmental

  12. Investigation of a large volume negative hydrogen ion source

    International Nuclear Information System (INIS)

    Courteille, C.; Bruneteau, A.M.; Bacal, M.

    1995-01-01

    The electron and negative ion densities and temperatures are reported for a large volume hybrid multicusp negative ion source. Based on the scaling laws an analysis is made of the plasma formation and loss processes. It is shown that the positive ions are predominantly lost to the walls, although the observed scaling law is n + ∝I 0.57 d . However, the total plasma loss scales linearly with the discharge current, in agreement with the theoretical model. The negative ion formation and loss is also discussed. It is shown that at low pressure (1 mTorr) the negative ion wall loss becomes a significant part of the total loss. The dependence of n - /n e versus the electron temperature is reported. When the negative ion wall loss is negligible, all the data on n - /n e versus the electron temperatures fit a single curve. copyright 1995 American Institute of Physics

  13. Symmetric relations of finite negativity

    NARCIS (Netherlands)

    Kaltenbaeck, M.; Winkler, H.; Woracek, H.; Forster, KH; Jonas, P; Langer, H

    2006-01-01

    We construct and investigate a space which is related to a symmetric linear relation S of finite negativity on an almost Pontryagin space. This space is the indefinite generalization of the completion of dom S with respect to (S.,.) for a strictly positive S on a Hilbert space.

  14. Linear Algebra and Smarandache Linear Algebra

    OpenAIRE

    Vasantha, Kandasamy

    2003-01-01

    The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and vector spaces over finite p...

  15. Linear network theory

    CERN Document Server

    Sander, K F

    1964-01-01

    Linear Network Theory covers the significant algebraic aspect of network theory, with minimal reference to practical circuits. The book begins the presentation of network analysis with the exposition of networks containing resistances only, and follows it up with a discussion of networks involving inductance and capacity by way of the differential equations. Classification and description of certain networks, equivalent networks, filter circuits, and network functions are also covered. Electrical engineers, technicians, electronics engineers, electricians, and students learning the intricacies

  16. Linear versus non-linear measures of temporal variability in finger tapping and their relation to performance on open- versus closed-loop motor tasks: comparing standard deviations to Lyapunov exponents.

    Science.gov (United States)

    Christman, Stephen D; Weaver, Ryan

    2008-05-01

    The nature of temporal variability during speeded finger tapping was examined using linear (standard deviation) and non-linear (Lyapunov exponent) measures. Experiment 1 found that right hand tapping was characterised by lower amounts of both linear and non-linear measures of variability than left hand tapping, and that linear and non-linear measures of variability were often negatively correlated with one another. Experiment 2 found that increased non-linear variability was associated with relatively enhanced performance on a closed-loop motor task (mirror tracing) and relatively impaired performance on an open-loop motor task (pointing in a dark room), especially for left hand performance. The potential uses and significance of measures of non-linear variability are discussed.

  17. Isotropic Negative Thermal Expansion Metamaterials.

    Science.gov (United States)

    Wu, Lingling; Li, Bo; Zhou, Ji

    2016-07-13

    Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

  18. Linearly constrained minimax optimization

    DEFF Research Database (Denmark)

    Madsen, Kaj; Schjær-Jacobsen, Hans

    1978-01-01

    We present an algorithm for nonlinear minimax optimization subject to linear equality and inequality constraints which requires first order partial derivatives. The algorithm is based on successive linear approximations to the functions defining the problem. The resulting linear subproblems...

  19. The Stanford Linear Collider

    International Nuclear Information System (INIS)

    Emma, P.

    1995-01-01

    The Stanford Linear Collider (SLC) is the first and only high-energy e + e - linear collider in the world. Its most remarkable features are high intensity, submicron sized, polarized (e - ) beams at a single interaction point. The main challenges posed by these unique characteristics include machine-wide emittance preservation, consistent high intensity operation, polarized electron production and transport, and the achievement of a high degree of beam stability on all time scales. In addition to serving as an important machine for the study of Z 0 boson production and decay using polarized beams, the SLC is also an indispensable source of hands-on experience for future linear colliders. Each new year of operation has been highlighted with a marked improvement in performance. The most significant improvements for the 1994-95 run include new low impedance vacuum chambers for the damping rings, an upgrade to the optics and diagnostics of the final focus systems, and a higher degree of polarization from the electron source. As a result, the average luminosity has nearly doubled over the previous year with peaks approaching 10 30 cm -2 s -1 and an 80% electron polarization at the interaction point. These developments as well as the remaining identifiable performance limitations will be discussed

  20. Miniature linear cooler development

    International Nuclear Information System (INIS)

    Pruitt, G.R.

    1993-01-01

    An overview is presented of the status of a family of miniature linear coolers currently under development by Hughes Aircraft Co. for use in hand held, volume limited or power limited infrared applications. These coolers, representing the latest additions to the Hughes family of TOP trademark [twin-opposed piston] linear coolers, have been fabricated and tested in three different configurations. Each configuration is designed to utilize a common compressor assembly resulting in reduced manufacturing costs. The baseline compressor has been integrated with two different expander configurations and has been operated with two different levels of input power. These various configuration combinations offer a wide range of performance and interface characteristics which may be tailored to applications requiring limited power and size without significantly compromising cooler capacity or cooldown characteristics. Key cooler characteristics and test data are summarized for three combinations of cooler configurations which are representative of the versatility of this linear cooler design. Configurations reviewed include the shortened coldfinger [1.50 to 1.75 inches long], limited input power [less than 17 Watts] for low power availability applications; the shortened coldfinger with higher input power for lightweight, higher performance applications; and coldfingers compatible with DoD 0.4 Watt Common Module coolers for wider range retrofit capability. Typical weight of these miniature linear coolers is less than 500 grams for the compressor, expander and interconnecting transfer line. Cooling capacity at 80K at room ambient conditions ranges from 400 mW to greater than 550 mW. Steady state power requirements for maintaining a heat load of 150 mW at 80K has been shown to be less than 8 Watts. Ongoing reliability growth testing is summarized including a review of the latest test article results

  1. Foundations of linear and generalized linear models

    CERN Document Server

    Agresti, Alan

    2015-01-01

    A valuable overview of the most important ideas and results in statistical analysis Written by a highly-experienced author, Foundations of Linear and Generalized Linear Models is a clear and comprehensive guide to the key concepts and results of linear statistical models. The book presents a broad, in-depth overview of the most commonly used statistical models by discussing the theory underlying the models, R software applications, and examples with crafted models to elucidate key ideas and promote practical model building. The book begins by illustrating the fundamentals of linear models,

  2. Linear wind generator

    International Nuclear Information System (INIS)

    Kozarov, A.; Petrov, O.; Antonov, J.; Sotirova, S.; Petrova, B.

    2006-01-01

    The purpose of the linear wind-power generator described in this article is to decrease the following disadvantages of the common wind-powered turbine: 1) large bending and twisting moments to the blades and the shaft, especially when strong winds and turbulence exist; 2) significant values of the natural oscillation period of the construction result in the possibility of occurrence of destroying resonance oscillations; 3) high velocity of the peripheral parts of the rotor creating a danger for birds; 4) difficulties, connected with the installation and the operation on the mountain ridges and passages where the wind energy potential is the largest. The working surfaces of the generator in questions driven by the wind are not connected with a joint shaft but each moves along a railway track with few oscillations. So the sizes of each component are small and their number can be rather large. The mechanical trajectory is not a circle but a closed outline in a vertical plain, which consists of two rectilinear sectors, one above the other, connected in their ends by semi-circumferences. The mechanical energy of each component turns into electrical on the principle of the linear electrical generator. A regulation is provided when the direction of the wind is perpendicular to the route. A possibility of effectiveness is shown through aiming of additional quantities of air to the movable components by static barriers

  3. This research is to study the factors which influence the business success of small business ‘processed rotan’. The data employed in the study are primary data within the period of July to August 2013, 30 research observations through census method. Method of analysis used in the study is multiple linear regressions. The results of analysis showed that the factors of labor, innovation and promotion have positive and significant influence on the business success of small business ‘processed rotan’ simultaneously. The analysis also showed that partially labor has positive and significant influence on the business success, yet innovation and promotion have insignificant and positive influence on the business success.

    OpenAIRE

    Nasution, Inggrita Gusti Sari; Muchtar, Yasmin Chairunnisa

    2013-01-01

    This research is to study the factors which influence the business success of small business ‘processed rotan’. The data employed in the study are primary data within the period of July to August 2013, 30 research observations through census method. Method of analysis used in the study is multiple linear regressions. The results of analysis showed that the factors of labor, innovation and promotion have positive and significant influence on the business success of small busine...

  4. Feedback systems for linear colliders

    CERN Document Server

    Hendrickson, L; Himel, Thomas M; Minty, Michiko G; Phinney, N; Raimondi, Pantaleo; Raubenheimer, T O; Shoaee, H; Tenenbaum, P G

    1999-01-01

    Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an intregal part of the design. Feedback requiremetns for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at hi...

  5. CERN balances linear collider studies

    CERN Multimedia

    ILC Newsline

    2011-01-01

    The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader.   The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...

  6. A linear programming manual

    Science.gov (United States)

    Tuey, R. C.

    1972-01-01

    Computer solutions of linear programming problems are outlined. Information covers vector spaces, convex sets, and matrix algebra elements for solving simultaneous linear equations. Dual problems, reduced cost analysis, ranges, and error analysis are illustrated.

  7. Linear shaped charge

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, David; Stofleth, Jerome H.; Saul, Venner W.

    2017-07-11

    Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.

  8. Classifying Linear Canonical Relations

    OpenAIRE

    Lorand, Jonathan

    2015-01-01

    In this Master's thesis, we consider the problem of classifying, up to conjugation by linear symplectomorphisms, linear canonical relations (lagrangian correspondences) from a finite-dimensional symplectic vector space to itself. We give an elementary introduction to the theory of linear canonical relations and present partial results toward the classification problem. This exposition should be accessible to undergraduate students with a basic familiarity with linear algebra.

  9. Linear-Algebra Programs

    Science.gov (United States)

    Lawson, C. L.; Krogh, F. T.; Gold, S. S.; Kincaid, D. R.; Sullivan, J.; Williams, E.; Hanson, R. J.; Haskell, K.; Dongarra, J.; Moler, C. B.

    1982-01-01

    The Basic Linear Algebra Subprograms (BLAS) library is a collection of 38 FORTRAN-callable routines for performing basic operations of numerical linear algebra. BLAS library is portable and efficient source of basic operations for designers of programs involving linear algebriac computations. BLAS library is supplied in portable FORTRAN and Assembler code versions for IBM 370, UNIVAC 1100 and CDC 6000 series computers.

  10. Linear pulse amplifier

    International Nuclear Information System (INIS)

    Tjutju, R.L.

    1977-01-01

    Pulse amplifier is standard significant part of spectrometer. Apart from other type of amplification, it's a combination of amplification and pulse shaping. Because of its special purpose the device should fulfill the following : High resolution is desired to gain a high yield comparable to its actual state of condition. High signal to noise is desired to nhν resolution. High linearity to facilitate calibration. A good overload recovery, in order to the device will capable of analizing a low energy radiation which appear joinly on the high energy fields. Other expections of the device are its economical and practical use its extentive application. For that reason it's built on a standard NIM principle. Taking also into account the above mentioned considerations. High quality component parts are used throughout, while its availability in the domestic market is secured. (author)

  11. Sharp bounds on the ranks of negativity of certain sums

    Indian Academy of Sciences (India)

    with a finite rank of negativity k (i.e., k is the maximal dimension of any linear subspace ..... By linear algebra, we can choose a linear subspace E of L which is mapped ...... matics and its applications (Cambridge University Press) (1994) vol. 49.

  12. Negative parity non-strange baryons

    International Nuclear Information System (INIS)

    Stancu, F.; Stassart, P.

    1991-01-01

    Our previous study is extended to negative parity baryon resonances up to J=(9/2) - . The framework is a semi-relativistic constituent quark model. The quark-quark interaction contains a Coulomb plus linear confinement terms and a short distance spin-spin and tensor terms. It is emphasized that a linear confinement potential gives too large a mass to the D 35 (1930) resonance. (orig.)

  13. Negative-ion states

    International Nuclear Information System (INIS)

    Compton, R.N.

    1982-01-01

    In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures

  14. Negative ion detachment processes

    International Nuclear Information System (INIS)

    Champion, R.L.; Doverspike, L.D.

    1990-10-01

    This paper discusses the following topics: H - and D - collisions with atomic hydrogen; collisional decomposition of SF 6 - ; two-electron loss processes in negative ion collisions; associative electron detachment; and negative ion desorption from surfaces

  15. Sentential Negation in English

    Science.gov (United States)

    Mowarin, Macaulay

    2009-01-01

    This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

  16. Linear interaction of gravitational waves

    International Nuclear Information System (INIS)

    Ciubotariu, C.D.

    1992-01-01

    Starting with the linearized Einstein equations written in the same form as Maxwell equations, a damping term is found in the wave equation. The analogy with the propagation of the electromagnetic wave in ohmic media is obvious if we introduce an 'ohmic relation' for gravitational interaction. The possibility of the amplification of gravitational waves by a suitable choice of the velocity field of a dust ('dust with negative viscosity'), for example by the use of the free-electron laser principle, is indicated. (Author)

  17. Stochastic Linear Quadratic Optimal Control Problems

    International Nuclear Information System (INIS)

    Chen, S.; Yong, J.

    2001-01-01

    This paper is concerned with the stochastic linear quadratic optimal control problem (LQ problem, for short) for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. Some intrinsic relations among the LQ problem, the stochastic maximum principle, and the (linear) forward-backward stochastic differential equations are established. Some results involving Riccati equation are discussed as well

  18. Negative ion sources

    International Nuclear Information System (INIS)

    Ishikawa, Junzo; Takagi, Toshinori

    1983-01-01

    Negative ion sources have been originally developed at the request of tandem electrostatic accelerators, and hundreds of nA to several μA negative ion current has been obtained so far for various elements. Recently, the development of large current hydrogen negative ion sources has been demanded from the standpoint of the heating by neutral particle beam injection in nuclear fusion reactors. On the other hand, the physical properties of negative ions are interesting in the thin film formation using ions. Anyway, it is the present status that the mechanism of negative ion action has not been so fully investigated as positive ions because the history of negative ion sources is short. In this report, the many mechanisms about the generation of negative ions proposed so far are described about negative ion generating mechanism, negative ion source plasma, and negative ion generation on metal surfaces. As a result, negative ion sources are roughly divided into two schemes, plasma extraction and secondary ion extraction, and the former is further classified into the PIG ion source and its variation and Duoplasmatron and its variation; while the latter into reflecting and sputtering types. In the second half of the report, the practical negative ion sources of each scheme are described. If the mechanism of negative ion generation will be investigated more in detail and the development will be continued under the unified know-how as negative ion sources in future, the development of negative ion sources with which large current can be obtained for any element is expected. (Wakatsuki, Y.)

  19. Non linear system become linear system

    Directory of Open Access Journals (Sweden)

    Petre Bucur

    2007-01-01

    Full Text Available The present paper refers to the theory and the practice of the systems regarding non-linear systems and their applications. We aimed the integration of these systems to elaborate their response as well as to highlight some outstanding features.

  20. Linear motor coil assembly and linear motor

    NARCIS (Netherlands)

    2009-01-01

    An ironless linear motor (5) comprising a magnet track (53) and a coil assembly (50) operating in cooperation with said magnet track (53) and having a plurality of concentrated multi-turn coils (31 a-f, 41 a-d, 51 a-k), wherein the end windings (31E) of the coils (31 a-f, 41 a-e) are substantially

  1. Polemic and Descriptive Negations

    DEFF Research Database (Denmark)

    Horslund, Camilla Søballe

    2011-01-01

    to semantics and pragmatics, negations can be used in three different ways, which gives rise to a typology of three different types of negations: 1) the descriptive negation, 2) the polemic negation, and 3) the meta-linguistic negation (Nølke 1999, 4). This typology illuminates the fact that the negation...... common in certain social context or genres, while polemic negations are more likely to come up in other genres and social settings. Previous studies have shown a relation between articulatory prominence and register, which may further inform the analysis. Hence, the paper investigates how articulatory...... prominence and register may either work in concert or oppose each other with respect to the cues they provide for the interpretation....

  2. Basic linear algebra

    CERN Document Server

    Blyth, T S

    2002-01-01

    Basic Linear Algebra is a text for first year students leading from concrete examples to abstract theorems, via tutorial-type exercises. More exercises (of the kind a student may expect in examination papers) are grouped at the end of each section. The book covers the most important basics of any first course on linear algebra, explaining the algebra of matrices with applications to analytic geometry, systems of linear equations, difference equations and complex numbers. Linear equations are treated via Hermite normal forms which provides a successful and concrete explanation of the notion of linear independence. Another important highlight is the connection between linear mappings and matrices leading to the change of basis theorem which opens the door to the notion of similarity. This new and revised edition features additional exercises and coverage of Cramer's rule (omitted from the first edition). However, it is the new, extra chapter on computer assistance that will be of particular interest to readers:...

  3. Social anxiety and negative early life events in university students.

    Science.gov (United States)

    Binelli, Cynthia; Ortiz, Ana; Muñiz, Armando; Gelabert, Estel; Ferraz, Liliana; S Filho, Alaor; Crippa, José Alexandre S; Nardi, Antonio E; Subirà, Susana; Martín-Santos, Rocío

    2012-06-01

    There is substantial evidence regarding the impact of negative life events during childhood on the aetiology of psychiatric disorders. We examined the association between negative early life events and social anxiety in a sample of 571 Spanish University students. In a cross-sectional survey conducted in 2007, we collected data through a semistructured questionnaire of sociodemographic variables, personal and family psychiatric history, and substance abuse. We assessed the five early negative life events: (i) the loss of someone close, (ii) emotional abuse, (iii) physical abuse, (iv) family violence, and (v) sexual abuse. All participants completed the Liebowitz Social Anxiety Scale. Mean (SD) age was 21 (4.5), 75% female, LSAS score was 40 (DP = 22), 14.2% had a psychiatric family history and 50.6% had negative life events during childhood. Linear regression analyses, after controlling for age, gender, and family psychiatric history, showed a positive association between family violence and social score (p = 0.03). None of the remaining stressors produced a significant increase in LSAS score (p > 0.05). University students with high levels of social anxiety presented higher prevalence of negative early life events. Thus, childhood family violence could be a risk factor for social anxiety in such a population.

  4. Matrices and linear transformations

    CERN Document Server

    Cullen, Charles G

    1990-01-01

    ""Comprehensive . . . an excellent introduction to the subject."" - Electronic Engineer's Design Magazine.This introductory textbook, aimed at sophomore- and junior-level undergraduates in mathematics, engineering, and the physical sciences, offers a smooth, in-depth treatment of linear algebra and matrix theory. The major objects of study are matrices over an arbitrary field. Contents include Matrices and Linear Systems; Vector Spaces; Determinants; Linear Transformations; Similarity: Part I and Part II; Polynomials and Polynomial Matrices; Matrix Analysis; and Numerical Methods. The first

  5. Efficient Non Linear Loudspeakers

    DEFF Research Database (Denmark)

    Petersen, Bo R.; Agerkvist, Finn T.

    2006-01-01

    Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...... by changing the voice coil layout. This deliberate non-linear design has the benefit that a smaller amplifier can be used, which has the benefit of reducing system cost as well as reducing power consumption....

  6. Linear models with R

    CERN Document Server

    Faraway, Julian J

    2014-01-01

    A Hands-On Way to Learning Data AnalysisPart of the core of statistics, linear models are used to make predictions and explain the relationship between the response and the predictors. Understanding linear models is crucial to a broader competence in the practice of statistics. Linear Models with R, Second Edition explains how to use linear models in physical science, engineering, social science, and business applications. The book incorporates several improvements that reflect how the world of R has greatly expanded since the publication of the first edition.New to the Second EditionReorganiz

  7. Linear integrated circuits

    CERN Document Server

    Carr, Joseph

    1996-01-01

    The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa

  8. Fault tolerant linear actuator

    Science.gov (United States)

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  9. Superconducting linear accelerator cryostat

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; Elkonin, B.V.; Sokolowski, J.S.

    1984-01-01

    A large vertical cryostat for a superconducting linear accelerator using quarter wave resonators has been developed. The essential technical details, operational experience and performance are described. (author)

  10. Linearity enigmas in ecology

    Energy Technology Data Exchange (ETDEWEB)

    Patten, B.C.

    1983-04-01

    Two issues concerning linearity or nonlinearity of natural systems are considered. Each is related to one of the two alternative defining properties of linear systems, superposition and decomposition. Superposition exists when a linear combination of inputs to a system results in the same linear combination of outputs that individually correspond to the original inputs. To demonstrate this property it is necessary that all initial states and inputs of the system which impinge on the output in question be included in the linear combination manipulation. As this is difficult or impossible to do with real systems of any complexity, nature appears nonlinear even though it may be linear. A linear system that displays nonlinear behavior for this reason is termed pseudononlinear. The decomposition property exists when the dynamic response of a system can be partitioned into an input-free portion due to state plus a state-free portion due to input. This is a characteristic of all linear systems, but not of nonlinear systems. Without the decomposition property, it is not possible to distinguish which portions of a system's behavior are due to innate characteristics (self) vs. outside conditions (environment), which is an important class of questions in biology and ecology. Some philosophical aspects of these findings are then considered. It is suggested that those ecologists who hold to the view that organisms and their environments are separate entities are in effect embracing a linear view of nature, even though their belief systems and mathematical models tend to be nonlinear. On the other hand, those who consider that organism-environment complex forms a single inseparable unit are implictly involved in non-linear thought, which may be in conflict with the linear modes and models that some of them use. The need to rectify these ambivalences on the part of both groups is indicated.

  11. Negative Ion Density Fronts

    International Nuclear Information System (INIS)

    Igor Kaganovich

    2000-01-01

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas

  12. Negative energy solutions and symmetries

    International Nuclear Information System (INIS)

    Sidharth, B.G.

    2011-01-01

    We revisit the negative energy solutions of the Dirac (and Klein–Gordon) equation, which become relevant at very high energies in the context of the Feshbach–Villars formulation, and study several symmetries which follow therefrom. Significant consequences are briefly examined. (author)

  13. Positive Quasi Linear Operator Formulation

    International Nuclear Information System (INIS)

    Berry, L.A.; Jaeger, E.F.

    2005-01-01

    Expressions for the RF quasi-linear operator are biquadratic sums over the Fourier modes (or FLR equivalent) that describe the RF electric field with a kernel that is a function of the two wave vectors, k-vector L and k-vector R , in the sum. As a result of either an implicit or explicit average over field lines or flux surfaces, this kernel only depends on one parallel wave vector, conventionally k R -vector. When k-vector is an independent component of the representation for E, the sums are demonstrably positive. However, except for closed field line systems, k-vector is dependent on the local direction of the equilibrium magnetic field, and, empirically, the absorbed energy and quasi-linear diffusion coefficients are observed to have negative features. We have formally introduced an independent k-vector sum by Fourier transforming the RF electric field (assuming straight field lines) using a field-line-length coordinate. The resulting expression is positive. We have modeled this approach by calculating the quasi linear operator for 'modes' with fixed k-vector. We form these modes by discretizing k-vector and then assigning all of the Fourier components with k-vectorthat fall within a given k-vector bin to that k-vector mode. Results will be shown as a function of the number of bins. Future work will involve implementing the expressions derived from the Fourier transform and evaluating the dependence on field line length

  14. Linear colliders - prospects 1985

    International Nuclear Information System (INIS)

    Rees, J.

    1985-06-01

    We discuss the scaling laws of linear colliders and their consequences for accelerator design. We then report on the SLAC Linear Collider project and comment on experience gained on that project and its application to future colliders. 9 refs., 2 figs

  15. The SLAC linear collider

    International Nuclear Information System (INIS)

    Richter, B.

    1985-01-01

    A report is given on the goals and progress of the SLAC Linear Collider. The author discusses the status of the machine and the detectors and give an overview of the physics which can be done at this new facility. He also gives some ideas on how (and why) large linear colliders of the future should be built

  16. Linear Programming (LP)

    International Nuclear Information System (INIS)

    Rogner, H.H.

    1989-01-01

    The submitted sections on linear programming are extracted from 'Theorie und Technik der Planung' (1978) by W. Blaas and P. Henseler and reformulated for presentation at the Workshop. They consider a brief introduction to the theory of linear programming and to some essential aspects of the SIMPLEX solution algorithm for the purposes of economic planning processes. 1 fig

  17. Racetrack linear accelerators

    International Nuclear Information System (INIS)

    Rowe, C.H.; Wilton, M.S. de.

    1979-01-01

    An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)

  18. Negative stiffness honeycombs as tunable elastic metamaterials

    Science.gov (United States)

    Goldsberry, Benjamin M.; Haberman, Michael R.

    2018-03-01

    Acoustic and elastic metamaterials are media with a subwavelength structure that behave as effective materials displaying atypical effective dynamic properties. These material systems are of interest because the design of their sub-wavelength structure allows for direct control of macroscopic wave dispersion. One major design limitation of most metamaterial structures is that the dynamic response cannot be altered once the microstructure is manufactured. However, the ability to modify wave propagation in the metamaterial with an external stimulus is highly desirable for numerous applications and therefore remains a significant challenge in elastic metamaterials research. In this work, a honeycomb structure composed of a doubly periodic array of curved beams, known as a negative stiffness honeycomb (NSH), is analyzed as a tunable elastic metamaterial. The nonlinear static elastic response that results from large deformations of the NSH unit cell leads to a large variation in linear elastic wave dispersion associated with infinitesimal motion superposed on the externally imposed pre-strain. A finite element model is utilized to model the static deformation and subsequent linear wave motion at the pre-strained state. Analysis of the slowness surface and group velocity demonstrates that the NSH exhibits significant tunability and a high degree of anisotropy which can be used to guide wave energy depending on static pre-strain levels. In addition, it is shown that partial band gaps exist where only longitudinal waves propagate. The NSH therefore behaves as a meta-fluid, or pentamode metamaterial, which may be of use for applications of transformation elastodynamics such as cloaking and gradient index lens devices.

  19. Semidefinite linear complementarity problems

    International Nuclear Information System (INIS)

    Eckhardt, U.

    1978-04-01

    Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

  20. Linear algebra done right

    CERN Document Server

    Axler, Sheldon

    2015-01-01

    This best-selling textbook for a second course in linear algebra is aimed at undergrad math majors and graduate students. The novel approach taken here banishes determinants to the end of the book. The text focuses on the central goal of linear algebra: understanding the structure of linear operators on finite-dimensional vector spaces. The author has taken unusual care to motivate concepts and to simplify proofs. A variety of interesting exercises in each chapter helps students understand and manipulate the objects of linear algebra. The third edition contains major improvements and revisions throughout the book. More than 300 new exercises have been added since the previous edition. Many new examples have been added to illustrate the key ideas of linear algebra. New topics covered in the book include product spaces, quotient spaces, and dual spaces. Beautiful new formatting creates pages with an unusually pleasant appearance in both print and electronic versions. No prerequisites are assumed other than the ...

  1. Handbook on linear motor application

    International Nuclear Information System (INIS)

    1988-10-01

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  2. Lithium alloy negative electrodes

    Science.gov (United States)

    Huggins, Robert A.

    The 1996 announcement by Fuji Photo Film of the development of lithium batteries containing convertible metal oxides has caused a great deal of renewed interest in lithium alloys as alternative materials for use in the negative electrode of rechargeable lithium cells. The earlier work on lithium alloys, both at elevated and ambient temperatures is briefly reviewed. Basic principles relating thermodynamics, phase diagrams and electrochemical properties under near-equilibrium conditions are discussed, with the Li-Sn system as an example. Second-phase nucleation, and its hindrance under dynamic conditions plays an important role in determining deviations from equilibrium behavior. Two general types of composite microstructure electrodes, those with a mixed-conducting matrix, and those with a solid electrolyte matrix, are discussed. The Li-Sn-Si system at elevated temperatures, and the Li-Sn-Cd at ambient temperatures are shown to be examples of mixed-conducting matrix microstructures. The convertible oxides are an example of the solid electrolyte matrix type. Although the reversible capacity can be very large in this case, the first cycle irreversible capacity required to convert the oxides to alloys may be a significant handicap.

  3. A Modality Called 'Negation'

    NARCIS (Netherlands)

    Berto, F.

    2015-01-01

    I propose a comprehensive account of negation as a modal operator, vindicating a moderate logical pluralism. Negation is taken as a quantifier on worlds, restricted by an accessibility relation encoding the basic concept of compatibility. This latter captures the core meaning of the operator. While

  4. Negative thermal expansion materials

    International Nuclear Information System (INIS)

    Evans, J.S.O.

    1997-01-01

    The recent discovery of negative thermal expansion over an unprecedented temperature range in ZrW 2 O 8 (which contracts continuously on warming from below 2 K to above 1000 K) has stimulated considerable interest in this unusual phenomenon. Negative and low thermal expansion materials have a number of important potential uses in ceramic, optical and electronic applications. We have now found negative thermal expansion in a large new family of materials with the general formula A 2 (MO 4 ) 3 . Chemical substitution dramatically influences the thermal expansion properties of these materials allowing the production of ceramics with negative, positive or zero coefficients of thermal expansion, with the potential to control other important materials properties such as refractive index and dielectric constant. The mechanism of negative thermal expansion and the phase transitions exhibited by this important new class of low-expansion materials will be discussed. (orig.)

  5. Five-year change in morale is associated with negative life events in very old age.

    Science.gov (United States)

    Näsman, Marina; Niklasson, Johan; Saarela, Jan; Nygård, Mikael; Olofsson, Birgitta; Conradsson, Mia; Lövheim, Hugo; Gustafson, Yngve; Nyqvist, Fredrica

    2017-10-27

    The objectives were to study changes in morale in individuals 85 years and older, and to assess the effect of negative life events on morale over a five-year follow-up period. The present study is based on longitudinal data from the Umeå85+/GERDA-study, including individuals 85 years and older at baseline (n = 204). Morale was measured with the Philadelphia Geriatric Center Morale Scale (PGCMS). Negative life events were assessed using an index including 13 negative life events occurring during the follow-up period. Linear regression was used for the multivariate analyses. The majority of the sample (69.1%) had no significant changes in morale during the five-year follow-up. However, the accumulation of negative life events was significantly associated with a greater decrease in PGCMS. A higher baseline PGCMS score did not attenuate the adverse effect negative life events had on morale. Morale seemed to be mainly stable in a five-year follow-up of very old people. It seems, nonetheless, that individuals are affected by negative life events, regardless of level of morale. Preventing negative life events and supporting individuals who experience multiple negative life events could have important implications for the care of very old people.

  6. Effect of Large Negative Phase of Blast Loading on Structural Response of RC Elements

    Directory of Open Access Journals (Sweden)

    Syed Zubair Iman

    2016-01-01

    Full Text Available Structural response of reinforced concrete (RC elements for analysis and design are often obtained using the positive phase of the blast pressure curve disregarding the negative phase assuming insignificant contribution from the negative phase of the loading. Although, some insight on the effect of negative phase of blast pressure based on elastic single-degree-of-freedom (SDOF analysis was presented before, the influence of negative phase on different types of resistance functions of SDOF models and on realistic finite element analysis has not been explored. In this study, the effects of inclusion of pulse negative phase on structural response of RC elements from SDOF analysis and from more detailed finite element analysis have been investigated. Investigation of SDOF part has been conducted using MATLAB code that utilizes non-linear resistance functions of SDOF model. Detailed numerical investigation using finite element code DIANA was conducted on the significance of the negative phase on structural response. In the FE model, different support stiffness was used to explore the effect of support stiffness on the structural response due to blast negative phase. Results from SDOF and FE analyses present specific situations where the effect of large negative phase was found to be significant on the structural response of RC elements.

  7. Linear ubiquitination in immunity.

    Science.gov (United States)

    Shimizu, Yutaka; Taraborrelli, Lucia; Walczak, Henning

    2015-07-01

    Linear ubiquitination is a post-translational protein modification recently discovered to be crucial for innate and adaptive immune signaling. The function of linear ubiquitin chains is regulated at multiple levels: generation, recognition, and removal. These chains are generated by the linear ubiquitin chain assembly complex (LUBAC), the only known ubiquitin E3 capable of forming the linear ubiquitin linkage de novo. LUBAC is not only relevant for activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) in various signaling pathways, but importantly, it also regulates cell death downstream of immune receptors capable of inducing this response. Recognition of the linear ubiquitin linkage is specifically mediated by certain ubiquitin receptors, which is crucial for translation into the intended signaling outputs. LUBAC deficiency results in attenuated gene activation and increased cell death, causing pathologic conditions in both, mice, and humans. Removal of ubiquitin chains is mediated by deubiquitinases (DUBs). Two of them, OTULIN and CYLD, are constitutively associated with LUBAC. Here, we review the current knowledge on linear ubiquitination in immune signaling pathways and the biochemical mechanisms as to how linear polyubiquitin exerts its functions distinctly from those of other ubiquitin linkage types. © 2015 The Authors. Immunological Reviews Published by John Wiley & Sons Ltd.

  8. Linearizing W-algebras

    International Nuclear Information System (INIS)

    Krivonos, S.O.; Sorin, A.S.

    1994-06-01

    We show that the Zamolodchikov's and Polyakov-Bershadsky nonlinear algebras W 3 and W (2) 3 can be embedded as subalgebras into some linear algebras with finite set of currents. Using these linear algebras we find new field realizations of W (2) 3 and W 3 which could be a starting point for constructing new versions of W-string theories. We also reveal a number of hidden relationships between W 3 and W (2) 3 . We conjecture that similar linear algebras can exist for other W-algebra as well. (author). 10 refs

  9. Matrices and linear algebra

    CERN Document Server

    Schneider, Hans

    1989-01-01

    Linear algebra is one of the central disciplines in mathematics. A student of pure mathematics must know linear algebra if he is to continue with modern algebra or functional analysis. Much of the mathematics now taught to engineers and physicists requires it.This well-known and highly regarded text makes the subject accessible to undergraduates with little mathematical experience. Written mainly for students in physics, engineering, economics, and other fields outside mathematics, the book gives the theory of matrices and applications to systems of linear equations, as well as many related t

  10. Linearity in Process Languages

    DEFF Research Database (Denmark)

    Nygaard, Mikkel; Winskel, Glynn

    2002-01-01

    The meaning and mathematical consequences of linearity (managing without a presumed ability to copy) are studied for a path-based model of processes which is also a model of affine-linear logic. This connection yields an affine-linear language for processes, automatically respecting open......-map bisimulation, in which a range of process operations can be expressed. An operational semantics is provided for the tensor fragment of the language. Different ways to make assemblies of processes lead to different choices of exponential, some of which respect bisimulation....

  11. Elements of linear space

    CERN Document Server

    Amir-Moez, A R; Sneddon, I N

    1962-01-01

    Elements of Linear Space is a detailed treatment of the elements of linear spaces, including real spaces with no more than three dimensions and complex n-dimensional spaces. The geometry of conic sections and quadric surfaces is considered, along with algebraic structures, especially vector spaces and transformations. Problems drawn from various branches of geometry are given.Comprised of 12 chapters, this volume begins with an introduction to real Euclidean space, followed by a discussion on linear transformations and matrices. The addition and multiplication of transformations and matrices a

  12. Applied linear regression

    CERN Document Server

    Weisberg, Sanford

    2013-01-01

    Praise for the Third Edition ""...this is an excellent book which could easily be used as a course text...""-International Statistical Institute The Fourth Edition of Applied Linear Regression provides a thorough update of the basic theory and methodology of linear regression modeling. Demonstrating the practical applications of linear regression analysis techniques, the Fourth Edition uses interesting, real-world exercises and examples. Stressing central concepts such as model building, understanding parameters, assessing fit and reliability, and drawing conclusions, the new edition illus

  13. Quantum entanglement at negative temperature

    International Nuclear Information System (INIS)

    Furman, G B; Meerovich, V M; Sokolovsky, V L

    2013-01-01

    An isolated spin system that is in internal thermodynamic equilibrium and that has an upper limit to its allowed energy states can possess a negative temperature. We calculate the thermodynamic characteristics and the concurrence in this system over the entire range of positive and negative temperatures. Our calculation was performed for different real structures, which can be used in experiments. It is found that the temperature dependence of the concurrence is substantially asymmetrical similarly to other thermodynamic characteristics. At a negative temperature the maximum concurrence and the absolute temperature of the entanglement appearance are significantly larger than those at a positive temperature. The concurrence can be characterized by two dimensionless parameters: the ratio between the Zeeman and dipolar energies and the ratio of the thermal and dipolar energies. It was shown that for all considered structures the dimensionless temperatures of the transition between entanglement and separability of the first and second spins are independent of spin structure and the number of spins. (paper)

  14. Charging of dust grains in a plasma with negative ions

    International Nuclear Information System (INIS)

    Mamun, A.A.; Shukla, P.K.

    2003-01-01

    The role of negative ions on the charging of dust grains in a plasma is examined. Two models for negative ion distributions are considered. These are streaming negative ions and Boltzmannian negative ions. It is found that the effects of the negative ion number density, negative ion charge, and negative ion streaming speed significantly affect the dust grain surface potential or the dust grain charge

  15. Linear system theory

    Science.gov (United States)

    Callier, Frank M.; Desoer, Charles A.

    1991-01-01

    The aim of this book is to provide a systematic and rigorous access to the main topics of linear state-space system theory in both the continuous-time case and the discrete-time case; and the I/O description of linear systems. The main thrusts of the work are the analysis of system descriptions and derivations of their properties, LQ-optimal control, state feedback and state estimation, and MIMO unity-feedback systems.

  16. Atomic negative ions

    International Nuclear Information System (INIS)

    Brage, T.

    1991-01-01

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given

  17. Feedback Systems for Linear Colliders

    International Nuclear Information System (INIS)

    1999-01-01

    Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an integral part of the design. Feedback requirements for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at high bandwidth and fast response. To correct for the motion of individual bunches within a train, both feedforward and feedback systems are planned. SLC experience has shown that feedback systems are an invaluable operational tool for decoupling systems, allowing precision tuning, and providing pulse-to-pulse diagnostics. Feedback systems for the NLC will incorporate the key SLC features and the benefits of advancing technologies

  18. Parameterized Linear Longitudinal Airship Model

    Science.gov (United States)

    Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph

    2010-01-01

    A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics

  19. JET VELOCITY OF LINEAR SHAPED CHARGES

    Directory of Open Access Journals (Sweden)

    Vječislav Bohanek

    2012-12-01

    Full Text Available Shaped explosive charges with one dimension significantly larger than the other are called linear shaped charges. Linear shaped charges are used in various industries and are applied within specific technologies for metal cutting, such as demolition of steel structures, separating spent rocket fuel tanks, demining, cutting holes in the barriers for fire service, etc. According to existing theories and models efficiency of linear shaped charges depends on the kinetic energy of the jet which is proportional to square of jet velocity. The original method for measuring velocity of linear shaped charge jet is applied in the aforementioned research. Measurements were carried out for two different linear materials, and the results are graphically presented, analysed and compared. Measurement results show a discrepancy in the measured velocity of the jet for different materials with the same ratio between linear and explosive mass (M/C per unit of surface, which is not described by presented models (the paper is published in Croatian.

  20. Linear Regression on Sparse Features for Single-Channel Speech Separation

    DEFF Research Database (Denmark)

    Schmidt, Mikkel N.; Olsson, Rasmus Kongsgaard

    2007-01-01

    In this work we address the problem of separating multiple speakers from a single microphone recording. We formulate a linear regression model for estimating each speaker based on features derived from the mixture. The employed feature representation is a sparse, non-negative encoding of the speech...... mixture in terms of pre-learned speaker-dependent dictionaries. Previous work has shown that this feature representation by itself provides some degree of separation. We show that the performance is significantly improved when regression analysis is performed on the sparse, non-negative features, both...

  1. Negativity Bias in Dangerous Drivers.

    Directory of Open Access Journals (Sweden)

    Jing Chai

    Full Text Available The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes.

  2. Genetic variation throughout the folate metabolic pathway influences negative symptom severity in schizophrenia.

    Science.gov (United States)

    Roffman, Joshua L; Brohawn, David G; Nitenson, Adam Z; Macklin, Eric A; Smoller, Jordan W; Goff, Donald C

    2013-03-01

    Low serum folate levels previously have been associated with negative symptom risk in schizophrenia, as has the hypofunctional 677C>T variant of the MTHFR gene. This study examined whether other missense polymorphisms in folate-regulating enzymes, in concert with MTHFR, influence negative symptoms in schizophrenia, and whether total risk allele load interacts with serum folate status to further stratify negative symptom risk. Medicated outpatients with schizophrenia (n = 219), all of European origin and some included in a previous report, were rated with the Positive and Negative Syndrome Scale. A subset of 82 patients also underwent nonfasting serum folate testing. Patients were genotyped for the MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), MTR 2756A>G (rs1805087), MTRR 203A>G (rs1801394), FOLH1 484T>C (rs202676), RFC 80A>G (rs1051266), and COMT 675G>A (rs4680) polymorphisms. All genotypes were entered into a linear regression model to determine significant predictors of negative symptoms, and risk scores were calculated based on total risk allele dose. Four variants, MTHFR 677T, MTR 2756A, FOLH1 484C, and COMT 675A, emerged as significant independent predictors of negative symptom severity, accounting for significantly greater variance in negative symptoms than MTHFR 677C>T alone. Total allele dose across the 4 variants predicted negative symptom severity only among patients with low folate levels. These findings indicate that multiple genetic variants within the folate metabolic pathway contribute to negative symptoms of schizophrenia. A relationship between folate level and negative symptom severity among patients with greater genetic vulnerability is biologically plausible and suggests the utility of folate supplementation in these patients.

  3. Further linear algebra

    CERN Document Server

    Blyth, T S

    2002-01-01

    Most of the introductory courses on linear algebra develop the basic theory of finite­ dimensional vector spaces, and in so doing relate the notion of a linear mapping to that of a matrix. Generally speaking, such courses culminate in the diagonalisation of certain matrices and the application of this process to various situations. Such is the case, for example, in our previous SUMS volume Basic Linear Algebra. The present text is a continuation of that volume, and has the objective of introducing the reader to more advanced properties of vector spaces and linear mappings, and consequently of matrices. For readers who are not familiar with the contents of Basic Linear Algebra we provide an introductory chapter that consists of a compact summary of the prerequisites for the present volume. In order to consolidate the student's understanding we have included a large num­ ber of illustrative and worked examples, as well as many exercises that are strategi­ cally placed throughout the text. Solutions to the ex...

  4. NEGATION AFFIXES IN ENGLISH

    Directory of Open Access Journals (Sweden)

    Dedy Subandowo -

    2017-02-01

    Full Text Available Abstract: This research entitled "Negation Affixes in English". This study is aimed to describe the various negation affixes in English, morphological process, morphophonemic and meaning. The research data were taken from various sources of English grammar book, morphology, research journal and the book which relatees to the research. English grammar books used in this study are written by Otto Jesperson, Marcella Frank, Greenbaum and Geoffrey Leech.  The method used in this research is the descriptive-qualitative method. While the data collection techniques are performed by using jot-down method. And the results of analysis are presented in tabular form and descriptive method. The result of the research shows that English has six types of negative affixes which are categorized by the intensity of its appearance, such as dis-, in-, non-, un-, anti- and -less. Based on the function, negation affixes are divided into several categories such as adjectives, nouns, verbs, and adverbs. The morphophonemic affix in- has four allomorphs, they are in-, im-, il- and ir- . While the analysis revealed that negation affixes have some basic meanings, such as ‘not’, ‘without’, and ‘anti’.

  5. Detecting Novelty and Significance

    Science.gov (United States)

    Ferrari, Vera; Bradley, Margaret M.; Codispoti, Maurizio; Lang, Peter J.

    2013-01-01

    Studies of cognition often use an “oddball” paradigm to study effects of stimulus novelty and significance on information processing. However, an oddball tends to be perceptually more novel than the standard, repeated stimulus as well as more relevant to the ongoing task, making it difficult to disentangle effects due to perceptual novelty and stimulus significance. In the current study, effects of perceptual novelty and significance on ERPs were assessed in a passive viewing context by presenting repeated and novel pictures (natural scenes) that either signaled significant information regarding the current context or not. A fronto-central N2 component was primarily affected by perceptual novelty, whereas a centro-parietal P3 component was modulated by both stimulus significance and novelty. The data support an interpretation that the N2 reflects perceptual fluency and is attenuated when a current stimulus matches an active memory representation and that the amplitude of the P3 reflects stimulus meaning and significance. PMID:19400680

  6. Significant NRC Enforcement Actions

    Data.gov (United States)

    Nuclear Regulatory Commission — This dataset provides a list of Nuclear Regulartory Commission (NRC) issued significant enforcement actions. These actions, referred to as "escalated", are issued by...

  7. Linear mass reflectron

    International Nuclear Information System (INIS)

    Mamyrin, B.A.; Shmikk, D.V.

    1979-01-01

    A description and operating principle of a linear mass reflectron with V-form trajectory of ion motion -a new non-magnetic time-of-flight mass spectrometer with high resolution are presented. The ion-optical system of the device consists of an ion source with ionization by electron shock, of accelerating gaps, reflector gaps, a drift space and ion detector. Ions move in the linear mass refraction along the trajectories parallel to the axis of the analyzer chamber. The results of investigations into the experimental device are given. With an ion drift length of 0.6 m the device resolution is 1200 with respect to the peak width at half-height. Small-sized mass spectrometric transducers with high resolution and sensitivity may be designed on the base of the linear mass reflectron principle

  8. Applied linear algebra

    CERN Document Server

    Olver, Peter J

    2018-01-01

    This textbook develops the essential tools of linear algebra, with the goal of imparting technique alongside contextual understanding. Applications go hand-in-hand with theory, each reinforcing and explaining the other. This approach encourages students to develop not only the technical proficiency needed to go on to further study, but an appreciation for when, why, and how the tools of linear algebra can be used across modern applied mathematics. Providing an extensive treatment of essential topics such as Gaussian elimination, inner products and norms, and eigenvalues and singular values, this text can be used for an in-depth first course, or an application-driven second course in linear algebra. In this second edition, applications have been updated and expanded to include numerical methods, dynamical systems, data analysis, and signal processing, while the pedagogical flow of the core material has been improved. Throughout, the text emphasizes the conceptual connections between each application and the un...

  9. Theory of linear operations

    CERN Document Server

    Banach, S

    1987-01-01

    This classic work by the late Stefan Banach has been translated into English so as to reach a yet wider audience. It contains the basics of the algebra of operators, concentrating on the study of linear operators, which corresponds to that of the linear forms a1x1 + a2x2 + ... + anxn of algebra.The book gathers results concerning linear operators defined in general spaces of a certain kind, principally in Banach spaces, examples of which are: the space of continuous functions, that of the pth-power-summable functions, Hilbert space, etc. The general theorems are interpreted in various mathematical areas, such as group theory, differential equations, integral equations, equations with infinitely many unknowns, functions of a real variable, summation methods and orthogonal series.A new fifty-page section (``Some Aspects of the Present Theory of Banach Spaces'''') complements this important monograph.

  10. Dimension of linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    1996-01-01

    Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four of these cri......Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....

  11. Linear programming using Matlab

    CERN Document Server

    Ploskas, Nikolaos

    2017-01-01

    This book offers a theoretical and computational presentation of a variety of linear programming algorithms and methods with an emphasis on the revised simplex method and its components. A theoretical background and mathematical formulation is included for each algorithm as well as comprehensive numerical examples and corresponding MATLAB® code. The MATLAB® implementations presented in this book  are sophisticated and allow users to find solutions to large-scale benchmark linear programs. Each algorithm is followed by a computational study on benchmark problems that analyze the computational behavior of the presented algorithms. As a solid companion to existing algorithmic-specific literature, this book will be useful to researchers, scientists, mathematical programmers, and students with a basic knowledge of linear algebra and calculus.  The clear presentation enables the reader to understand and utilize all components of simplex-type methods, such as presolve techniques, scaling techniques, pivoting ru...

  12. Linear Colliders TESLA

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The aim of the TESLA (TeV Superconducting Linear Accelerator) collaboration (at present 19 institutions from seven countries) is to establish the technology for a high energy electron-positron linear collider using superconducting radiofrequency cavities to accelerate its beams. Another basic goal is to demonstrate that such a collider can meet its performance goals in a cost effective manner. For this the TESLA collaboration is preparing a 500 MeV superconducting linear test accelerator at the DESY Laboratory in Hamburg. This TTF (TESLA Test Facility) consists of four cryomodules, each approximately 12 m long and containing eight 9-cell solid niobium cavities operating at a frequency of 1.3 GHz

  13. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

    Hansen, M.R.; Andersen, T.O.

    2010-01-01

    This paper is concerned with the inherent oscillatory nature of pressure compensated velocity control of a hydraulic cylinder subjected to a negative load and suspended by means of an over-center valve. Initially, a linearized stability analysis of such a hydraulic circuit is carried out clearly ...... in a nonlinear time domain simulation model validating the linear stability analysis....

  14. On Various Negative Translations

    Directory of Open Access Journals (Sweden)

    Gilda Ferreira

    2011-01-01

    Full Text Available Several proof translations of classical mathematics into intuitionistic mathematics have been proposed in the literature over the past century. These are normally referred to as negative translations or double-negation translations. Among those, the most commonly cited are translations due to Kolmogorov, Godel, Gentzen, Kuroda and Krivine (in chronological order. In this paper we propose a framework for explaining how these different translations are related to each other. More precisely, we define a notion of a (modular simplification starting from Kolmogorov translation, which leads to a partial order between different negative translations. In this derived ordering, Kuroda and Krivine are minimal elements. Two new minimal translations are introduced, with Godel and Gentzen translations sitting in between Kolmogorov and one of these new translations.

  15. Negative ion sourcery

    International Nuclear Information System (INIS)

    Os, C.F.A. van.

    1989-01-01

    The work described in this thesis is involved by current research programs in the field of nuclear-fusion. A brief introduction to fusion is given, anticipated problems related to current drive of the fusion plasma are pinpointed and probable suggestions to overcome these problems are described. One probable means for current drive is highlighted; Neutral Beam Injection (NBI). This is based on injecting a 1 MeV neutral hydrogen or deuterium beam into a fusion plasma. Negative ions are needed as primary particles because they can easily be neutralized at 1 MeV. The two current schemes for production of negative ions are described, volume production and negative surface ionization. The latter method is extensively studied in this thesis. (author). 171 refs.; 55 figs.; 7 tabs

  16. Linearly Adjustable International Portfolios

    Science.gov (United States)

    Fonseca, R. J.; Kuhn, D.; Rustem, B.

    2010-09-01

    We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.

  17. Linearly Adjustable International Portfolios

    International Nuclear Information System (INIS)

    Fonseca, R. J.; Kuhn, D.; Rustem, B.

    2010-01-01

    We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.

  18. Linear induction motor

    International Nuclear Information System (INIS)

    Barkman, W.E.; Adams, W.Q.; Berrier, B.R.

    1978-01-01

    A linear induction motor has been operated on a test bed with a feedback pulse resolution of 5 nm (0.2 μin). Slewing tests with this slide drive have shown positioning errors less than or equal to 33 nm (1.3 μin) at feedrates between 0 and 25.4 mm/min (0-1 ipm). A 0.86-m (34-in)-stroke linear motor is being investigated, using the SPACO machine as a test bed. Initial results were encouraging, and work is continuing to optimize the servosystem compensation

  19. Handbook of linear algebra

    CERN Document Server

    Hogben, Leslie

    2013-01-01

    With a substantial amount of new material, the Handbook of Linear Algebra, Second Edition provides comprehensive coverage of linear algebra concepts, applications, and computational software packages in an easy-to-use format. It guides you from the very elementary aspects of the subject to the frontiers of current research. Along with revisions and updates throughout, the second edition of this bestseller includes 20 new chapters.New to the Second EditionSeparate chapters on Schur complements, additional types of canonical forms, tensors, matrix polynomials, matrix equations, special types of

  20. Linear Algebra Thoroughly Explained

    CERN Document Server

    Vujičić, Milan

    2008-01-01

    Linear Algebra Thoroughly Explained provides a comprehensive introduction to the subject suitable for adoption as a self-contained text for courses at undergraduate and postgraduate level. The clear and comprehensive presentation of the basic theory is illustrated throughout with an abundance of worked examples. The book is written for teachers and students of linear algebra at all levels and across mathematics and the applied sciences, particularly physics and engineering. It will also be an invaluable addition to research libraries as a comprehensive resource book for the subject.

  1. Statistical monitoring of linear antenna arrays

    KAUST Repository

    Harrou, Fouzi; Sun, Ying

    2016-01-01

    The paper concerns the problem of monitoring linear antenna arrays using the generalized likelihood ratio (GLR) test. When an abnormal event (fault) affects an array of antenna elements, the radiation pattern changes and significant deviation from

  2. Nonlinear instabilities relating to negative-energy modes

    International Nuclear Information System (INIS)

    Pfirsch, D.

    1993-03-01

    The nonlinear instability of general linearly stable systems allowing linear negative-energy perturbations is investigated with the aid of a multiple time scale formalism. It is shown that the basic equations thus obtained imply resonance conditions and possess inherent symmetries which lead to the existence of similarity solutions of these equations. These solutions can be of an explosive type, oscillatory or static. It is demonstrated that at least some of the oscillatory and static solutions are normally linearly unstable. (orig.). 5 figs

  3. A CMOS rail-to-rail linear VI-converter

    NARCIS (Netherlands)

    Vervoort, P.P.; Vervoort, P.P.; Wassenaar, R.F.

    1995-01-01

    A linear CMOS VI-converter operating in strong inversion with a common-mode input range from the negative to the positive supply rail is presented. The circuit consists of three linear VI-converters based on the difference of squares principle. Two of these perform the actual V to I conversion,

  4. America, Linearly Cyclical

    Science.gov (United States)

    2013-05-10

    AND VICTIM- ~ vAP BLAMING 4. AMERICA, LINEARLY CYCUCAL AF IMT 1768, 19840901, V5 PREVIOUS EDITION WILL BE USED. C2C Jessica Adams Dr. Brissett...his desires, his failings, and his aspirations follow the same general trend throughout history and throughout cultures. The founding fathers sought

  5. Stanford's linear collider

    International Nuclear Information System (INIS)

    Southworth, B.

    1985-01-01

    The peak of the construction phase of the Stanford Linear Collider, SLC, to achieve 50 GeV electron-positron collisions has now been passed. The work remains on schedule to attempt colliding beams, initially at comparatively low luminosity, early in 1987. (orig./HSI).

  6. Dosimetry of linear sources

    International Nuclear Information System (INIS)

    Mafra Neto, F.

    1992-01-01

    The dose of gamma radiation from a linear source of cesium 137 is obtained, presenting two difficulties: oblique filtration of radiation when cross the platinum wall, in different directions, and dose connection due to the scattering by the material mean of propagation. (C.G.C.)

  7. Resistors Improve Ramp Linearity

    Science.gov (United States)

    Kleinberg, L. L.

    1982-01-01

    Simple modification to bootstrap ramp generator gives more linear output over longer sweep times. New circuit adds just two resistors, one of which is adjustable. Modification cancels nonlinearities due to variations in load on charging capacitor and due to changes in charging current as the voltage across capacitor increases.

  8. LINEAR COLLIDERS: 1992 workshop

    International Nuclear Information System (INIS)

    Settles, Ron; Coignet, Guy

    1992-01-01

    As work on designs for future electron-positron linear colliders pushes ahead at major Laboratories throughout the world in a major international collaboration framework, the LC92 workshop held in Garmisch Partenkirchen this summer, attended by 200 machine and particle physicists, provided a timely focus

  9. Linear genetic programming

    CERN Document Server

    Brameier, Markus

    2007-01-01

    Presents a variant of Genetic Programming that evolves imperative computer programs as linear sequences of instructions, in contrast to the more traditional functional expressions or syntax trees. This book serves as a reference for researchers, but also contains sufficient introduction for students and those who are new to the field

  10. On Solving Linear Recurrences

    Science.gov (United States)

    Dobbs, David E.

    2013-01-01

    A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.

  11. Review of linear colliders

    International Nuclear Information System (INIS)

    Takeda, Seishi

    1992-01-01

    The status of R and D of future e + e - linear colliders proposed by the institutions throughout the world is described including the JLC, NLC, VLEPP, CLIC, DESY/THD and TESLA projects. The parameters and RF sources are discussed. (G.P.) 36 refs.; 1 tab

  12. Quantization of the Linearized Kepler Problem

    OpenAIRE

    Guerrero, Julio; Perez, Jose Miguel

    2003-01-01

    The linearized Kepler problem is considered, as obtained from the Kustaanheimo-Stiefel (K-S)transformation, both for negative and positive energies. The symmetry group for the Kepler problem turns out to be SU(2,2). For negative energies, the Hamiltonian of Kepler problem can be realized as the sum of the energies of four harmonic oscillator with the same frequency, with a certain constrain. For positive energies, it can be realized as the sum of the energies of four repulsive oscillator with...

  13. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana

    the rate of surgical wound infection and wound exudate post-caesarean and that wound infection had a negative impact on quality of life one month after surgery. Alongside the clinical trial, a trial-based cost-effectiveness analysis demonstrated that the treatment is cost-effective in a high......Women with a pre-gestational body mass index (BMI) above 30 kg/m2 giving birth by caesarean section are at high risk of surgical wound infection compared with women with a BMI below 30 kg/m2. Incisional Negative Pressure Wound Therapy (iNPWT) is one strategy to reduce the rate of surgical wound...... a randomised controlled trial in two tertiary and three teaching hospitals in three regions of Denmark, the Happy Belly Study, investigating the effectiveness of iNPWT in a population of obese women after caesarean section. The Happy Belly Study has demonstrated that prophylactic iNPWT significantly reduced...

  14. Finite-dimensional linear algebra

    CERN Document Server

    Gockenbach, Mark S

    2010-01-01

    Some Problems Posed on Vector SpacesLinear equationsBest approximationDiagonalizationSummaryFields and Vector SpacesFields Vector spaces Subspaces Linear combinations and spanning sets Linear independence Basis and dimension Properties of bases Polynomial interpolation and the Lagrange basis Continuous piecewise polynomial functionsLinear OperatorsLinear operatorsMore properties of linear operatorsIsomorphic vector spaces Linear operator equations Existence and uniqueness of solutions The fundamental theorem; inverse operatorsGaussian elimination Newton's method Linear ordinary differential eq

  15. Significance of perfectionism in understanding different forms of insomnia

    Directory of Open Access Journals (Sweden)

    Totić-Poznanović Sanja

    2012-01-01

    Full Text Available Introduction. Studies consistently show a connection between perfectionism as a multidimensional construct with various psychological and psychopathological states and characteristics. However, studies that analyze the connection between this concept and sleep disturbances, especially modalities of insomnia, are rare. Objective. The aim of this study was to examine whether dimensions of perfectionism can explain different forms of insomnia; difficulties initiating sleep (insomnia early, difficulties during the sleep (insomnia middle, waking in early hours of the morning (insomnia late and dissatisfaction with sleep quality (subjective insomnia. Methods. The sample consisted of 254 students of the School of Medicine in Belgrade. Predictive significance of nine perfectionism dimensions, measured by Frost’s and Hewitt’s and Flett’s scales of multi-dimensional perfectionism, related to four modalities of insomnia, measured by a structured questionnaire, was analyzed by multiple linear regression method. Results. Perfectionism dimensions are significant predictors of each of the tested forms of insomnia. Doubt about actions significantly predicts initial insomnia; to other-oriented perfectionism in the negative pole and socially prescribed perfectionism underlie the difficulties during the sleep, while organization and parental criticism underlie late insomnia. Significant predictors of subjective insomnia are personal standards and organization and to other-oriented perfectionism on the negative pole. Three of nine analyzed dimensions were not confirmed as significant; concern over mistakes, parental expectations and self-oriented perfectionism. Conclusion. Various aspects of perfectionism can be considered as a vulnerability factor for understanding some forms of insomnia. Out of all forms of insomnia tested, perfectionism as the personality trait proved to be the most significant for understanding subjective insomnia.

  16. Dualising Intuitionictic Negation

    Directory of Open Access Journals (Sweden)

    Graham Priest

    2009-01-01

    Full Text Available One of Da Costa's motives when he constructed the paraconsistent logic Cw was to dualise the negation of intuitionistic logic. In this paper I explore a different way of going about this task. A logic is defined by taking the Kripke semantics for intuitionistic logic, and dualising the truth conditions for negation. Various properties of the logic are established, including its relation to CWo Tableau and natural deduction systems for the logic are produced, as are appropriate algebraic structures. The paper then investigates dualising the intuitionistic conditional in the same way. This establishes various connections between the logic, and a logic called in the literature 'Brouwerian logic' or 'closed-set logic'.

  17. Dualising Intuitionistic Negation

    Directory of Open Access Journals (Sweden)

    Graham Priest

    2009-08-01

    Full Text Available One of Da Costa’s motives when he constructed the paraconsistent logic C! was to dualise the negation of intuitionistic logic. In this paper I explore a different way of going about this task. A logic is defined by taking the Kripke semantics for intuitionistic logic, and dualising the truth conditions for negation. Various properties of the logic are established, including its relation to C!. Tableau and natural deduction systems for the logic are produced, as are appropriate algebraic structures. The paper then investigates dualising the intuitionistic conditional in the same way. This establishes various connections between the logic, and a logic called in the literature ‘Brouwerian logic’ or ‘closed-set logic’.

  18. Linearity and Non-linearity of Photorefractive effect in Materials ...

    African Journals Online (AJOL)

    In this paper we have studied the Linearity and Non-linearity of Photorefractive effect in materials using the band transport model. For low light beam intensities the change in the refractive index is proportional to the electric field for linear optics while for non- linear optics the change in refractive index is directly proportional ...

  19. Linearly Refined Session Types

    Directory of Open Access Journals (Sweden)

    Pedro Baltazar

    2012-11-01

    Full Text Available Session types capture precise protocol structure in concurrent programming, but do not specify properties of the exchanged values beyond their basic type. Refinement types are a form of dependent types that can address this limitation, combining types with logical formulae that may refer to program values and can constrain types using arbitrary predicates. We present a pi calculus with assume and assert operations, typed using a session discipline that incorporates refinement formulae written in a fragment of Multiplicative Linear Logic. Our original combination of session and refinement types, together with the well established benefits of linearity, allows very fine-grained specifications of communication protocols in which refinement formulae are treated as logical resources rather than persistent truths.

  20. Linear Water Waves

    Science.gov (United States)

    Kuznetsov, N.; Maz'ya, V.; Vainberg, B.

    2002-08-01

    This book gives a self-contained and up-to-date account of mathematical results in the linear theory of water waves. The study of waves has many applications, including the prediction of behavior of floating bodies (ships, submarines, tension-leg platforms etc.), the calculation of wave-making resistance in naval architecture, and the description of wave patterns over bottom topography in geophysical hydrodynamics. The first section deals with time-harmonic waves. Three linear boundary value problems serve as the approximate mathematical models for these types of water waves. The next section uses a plethora of mathematical techniques in the investigation of these three problems. The techniques used in the book include integral equations based on Green's functions, various inequalities between the kinetic and potential energy and integral identities which are indispensable for proving the uniqueness theorems. The so-called inverse procedure is applied to constructing examples of non-uniqueness, usually referred to as 'trapped nodes.'

  1. The International Linear Collider

    Directory of Open Access Journals (Sweden)

    List Benno

    2014-04-01

    Full Text Available The International Linear Collider (ILC is a proposed e+e− linear collider with a centre-of-mass energy of 200–500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.

  2. The International Linear Collider

    Science.gov (United States)

    List, Benno

    2014-04-01

    The International Linear Collider (ILC) is a proposed e+e- linear collider with a centre-of-mass energy of 200-500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.

  3. Dimension of linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    1996-01-01

    Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....... of these criteria are widely used ones, while the remaining four are ones derived from the H-principle of mathematical modeling. Many examples from practice show that the criteria derived from the H-principle function better than the known and popular criteria for the number of components. We shall briefly review...

  4. Reciprocating linear motor

    Science.gov (United States)

    Goldowsky, Michael P. (Inventor)

    1987-01-01

    A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

  5. Duality in linearized gravity

    International Nuclear Information System (INIS)

    Henneaux, Marc; Teitelboim, Claudio

    2005-01-01

    We show that duality transformations of linearized gravity in four dimensions, i.e., rotations of the linearized Riemann tensor and its dual into each other, can be extended to the dynamical fields of the theory so as to be symmetries of the action and not just symmetries of the equations of motion. Our approach relies on the introduction of two superpotentials, one for the spatial components of the spin-2 field and the other for their canonically conjugate momenta. These superpotentials are two-index, symmetric tensors. They can be taken to be the basic dynamical fields and appear locally in the action. They are simply rotated into each other under duality. In terms of the superpotentials, the canonical generator of duality rotations is found to have a Chern-Simons-like structure, as in the Maxwell case

  6. The SLAC linear collider

    International Nuclear Information System (INIS)

    Phinney, N.

    1992-01-01

    The SLAC Linear Collider has begun a new era of operation with the SLD detector. During 1991 there was a first engineering run for the SLD in parallel with machine improvements to increase luminosity and reliability. For the 1992 run, a polarized electron source was added and more than 10,000 Zs with an average of 23% polarization have been logged by the SLD. This paper discusses the performance of the SLC in 1991 and 1992 and the technical advances that have produced higher luminosity. Emphasis will be placed on issues relevant to future linear colliders such as producing and maintaining high current, low emittance beams and focusing the beams to the micron scale for collisions. (Author) tab., 2 figs., 18 refs

  7. Linear waves and instabilities

    International Nuclear Information System (INIS)

    Bers, A.

    1975-01-01

    The electrodynamic equations for small-amplitude waves and their dispersion relation in a homogeneous plasma are outlined. For such waves, energy and momentum, and their flow and transformation, are described. Perturbation theory of waves is treated and applied to linear coupling of waves, and the resulting instabilities from such interactions between active and passive waves. Linear stability analysis in time and space is described where the time-asymptotic, time-space Green's function for an arbitrary dispersion relation is developed. The perturbation theory of waves is applied to nonlinear coupling, with particular emphasis on pump-driven interactions of waves. Details of the time--space evolution of instabilities due to coupling are given. (U.S.)

  8. Extended linear chain compounds

    CERN Document Server

    Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com­ plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper­ imental solid state physics/chemistry communities, was based on the obser­ vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso­ tropic electrical, optical, magnetic, and mechanical properties, the conver­ gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...

  9. Negative Pressure Wound Therapy in Maxillofacial Applications

    Directory of Open Access Journals (Sweden)

    Adam J. Mellott

    2016-09-01

    Full Text Available Negative pressure wound therapy has greatly advanced the field of wound healing for nearly two decades, by providing a robust surgical adjunct technique for accelerating wound closure in acute and chronic wounds. However, the application of negative pressure wound therapy in maxillofacial applications has been relatively under utilized as a result of the physical articulations and contours of the head and neck that make it challenging to obtain an airtight seal for different negative pressure wound therapy systems. Adapting negative pressure wound therapies for maxillofacial applications could yield significant enhancement of wound closure in maxillofacial applications. The current review summarizes the basic science underlying negative pressure wound therapy, as well as specific maxillofacial procedures that could benefit from negative pressure wound therapy.

  10. Linear scleroderma following Blaschko′s lines

    Directory of Open Access Journals (Sweden)

    Mukhopadhyay Amiya

    2005-01-01

    Full Text Available Blaschko′s lines form a pattern, which many diseases are found to follow, but linear scleroderma following Blaschko′s lines is a controversial entity rarely reported in the literature. A 24-year-old man presented with multiple linear, atrophic, hyperpigmented lesions punctuated by areas of depigmentations on the left half of the trunk distributed on the anterior, lateral and posterior aspects. The lesions were distributed in a typical S-shaped line. Antinuclear antibody and antihistone antibody tests were negative. Histopathological examination of the skin from the affected area showed features suggestive of scleroderma. Here, we present a case of linear scleroderma following Blaschko′s lines in a male patient - an entity reported only three times so far.

  11. Non-linear osmosis

    Science.gov (United States)

    Diamond, Jared M.

    1966-01-01

    1. The relation between osmotic gradient and rate of osmotic water flow has been measured in rabbit gall-bladder by a gravimetric procedure and by a rapid method based on streaming potentials. Streaming potentials were directly proportional to gravimetrically measured water fluxes. 2. As in many other tissues, water flow was found to vary with gradient in a markedly non-linear fashion. There was no consistent relation between the water permeability and either the direction or the rate of water flow. 3. Water flow in response to a given gradient decreased at higher osmolarities. The resistance to water flow increased linearly with osmolarity over the range 186-825 m-osM. 4. The resistance to water flow was the same when the gall-bladder separated any two bathing solutions with the same average osmolarity, regardless of the magnitude of the gradient. In other words, the rate of water flow is given by the expression (Om — Os)/[Ro′ + ½k′ (Om + Os)], where Ro′ and k′ are constants and Om and Os are the bathing solution osmolarities. 5. Of the theories advanced to explain non-linear osmosis in other tissues, flow-induced membrane deformations, unstirred layers, asymmetrical series-membrane effects, and non-osmotic effects of solutes could not explain the results. However, experimental measurements of water permeability as a function of osmolarity permitted quantitative reconstruction of the observed water flow—osmotic gradient curves. Hence non-linear osmosis in rabbit gall-bladder is due to a decrease in water permeability with increasing osmolarity. 6. The results suggest that aqueous channels in the cell membrane behave as osmometers, shrinking in concentrated solutions of impermeant molecules and thereby increasing membrane resistance to water flow. A mathematical formulation of such a membrane structure is offered. PMID:5945254

  12. Fundamentals of linear algebra

    CERN Document Server

    Dash, Rajani Ballav

    2008-01-01

    FUNDAMENTALS OF LINEAR ALGEBRA is a comprehensive Text Book, which can be used by students and teachers of All Indian Universities. The Text has easy, understandable form and covers all topics of UGC Curriculum. There are lots of worked out examples which helps the students in solving the problems without anybody's help. The Problem sets have been designed keeping in view of the questions asked in different examinations.

  13. Non linear viscoelastic models

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.

    2011-01-01

    Viscoelastic eects are often present in loudspeaker suspensions, this can be seen in the displacement transfer function which often shows a frequency dependent value below the resonance frequency. In this paper nonlinear versions of the standard linear solid model (SLS) are investigated....... The simulations show that the nonlinear version of the Maxwell SLS model can result in a time dependent small signal stiness while the Kelvin Voight version does not....

  14. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  15. Superconducting linear colliders

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The advantages of superconducting radiofrequency (SRF) for particle accelerators have been demonstrated by successful operation of systems in the TRISTAN and LEP electron-positron collider rings respectively at the Japanese KEK Laboratory and at CERN. If performance continues to improve and costs can be lowered, this would open an attractive option for a high luminosity TeV (1000 GeV) linear collider

  16. Perturbed asymptotically linear problems

    OpenAIRE

    Bartolo, R.; Candela, A. M.; Salvatore, A.

    2012-01-01

    The aim of this paper is investigating the existence of solutions of some semilinear elliptic problems on open bounded domains when the nonlinearity is subcritical and asymptotically linear at infinity and there is a perturbation term which is just continuous. Also in the case when the problem has not a variational structure, suitable procedures and estimates allow us to prove that the number of distinct crtitical levels of the functional associated to the unperturbed problem is "stable" unde...

  17. Linear pneumatic actuator

    Directory of Open Access Journals (Sweden)

    Avram Mihai

    2017-01-01

    Full Text Available The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber, two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation accomplished.

  18. Linear pneumatic actuator

    OpenAIRE

    Avram Mihai; Niţu Constantin; Bucşan Constantin; Grămescu Bogdan

    2017-01-01

    The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber), two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation) accomplished.

  19. Linear MHD equilibria

    International Nuclear Information System (INIS)

    Scheffel, J.

    1984-03-01

    The linear Grad-Shafranov equation for a toroidal, axisymmetric plasma is solved analytically. Exact solutions are given in terms of confluent hyper-geometric functions. As an alternative, simple and accurate WKBJ solutions are presented. With parabolic pressure profiles, both hollow and peaked toroidal current density profiles are obtained. As an example the equilibrium of a z-pinch with a square-shaped cross section is derived.(author)

  20. Linear induction accelerator

    Science.gov (United States)

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  1. Linear algebraic groups

    CERN Document Server

    Springer, T A

    1998-01-01

    "[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...

  2. Parametric Linear Dynamic Logic

    Directory of Open Access Journals (Sweden)

    Peter Faymonville

    2014-08-01

    Full Text Available We introduce Parametric Linear Dynamic Logic (PLDL, which extends Linear Dynamic Logic (LDL by temporal operators equipped with parameters that bound their scope. LDL was proposed as an extension of Linear Temporal Logic (LTL that is able to express all ω-regular specifications while still maintaining many of LTL's desirable properties like an intuitive syntax and a translation into non-deterministic Büchi automata of exponential size. But LDL lacks capabilities to express timing constraints. By adding parameterized operators to LDL, we obtain a logic that is able to express all ω-regular properties and that subsumes parameterized extensions of LTL like Parametric LTL and PROMPT-LTL. Our main technical contribution is a translation of PLDL formulas into non-deterministic Büchi word automata of exponential size via alternating automata. This yields a PSPACE model checking algorithm and a realizability algorithm with doubly-exponential running time. Furthermore, we give tight upper and lower bounds on optimal parameter values for both problems. These results show that PLDL model checking and realizability are not harder than LTL model checking and realizability.

  3. Quantum linear Boltzmann equation

    International Nuclear Information System (INIS)

    Vacchini, Bassano; Hornberger, Klaus

    2009-01-01

    We review the quantum version of the linear Boltzmann equation, which describes in a non-perturbative fashion, by means of scattering theory, how the quantum motion of a single test particle is affected by collisions with an ideal background gas. A heuristic derivation of this Lindblad master equation is presented, based on the requirement of translation-covariance and on the relation to the classical linear Boltzmann equation. After analyzing its general symmetry properties and the associated relaxation dynamics, we discuss a quantum Monte Carlo method for its numerical solution. We then review important limiting forms of the quantum linear Boltzmann equation, such as the case of quantum Brownian motion and pure collisional decoherence, as well as the application to matter wave optics. Finally, we point to the incorporation of quantum degeneracies and self-interactions in the gas by relating the equation to the dynamic structure factor of the ambient medium, and we provide an extension of the equation to include internal degrees of freedom.

  4. Entanglement negativity bounds for fermionic Gaussian states

    Science.gov (United States)

    Eisert, Jens; Eisler, Viktor; Zimborás, Zoltán

    2018-04-01

    The entanglement negativity is a versatile measure of entanglement that has numerous applications in quantum information and in condensed matter theory. It can not only efficiently be computed in the Hilbert space dimension, but for noninteracting bosonic systems, one can compute the negativity efficiently in the number of modes. However, such an efficient computation does not carry over to the fermionic realm, the ultimate reason for this being that the partial transpose of a fermionic Gaussian state is no longer Gaussian. To provide a remedy for this state of affairs, in this work, we introduce efficiently computable and rigorous upper and lower bounds to the negativity, making use of techniques of semidefinite programming, building upon the Lagrangian formulation of fermionic linear optics, and exploiting suitable products of Gaussian operators. We discuss examples in quantum many-body theory and hint at applications in the study of topological properties at finite temperature.

  5. Significant Tsunami Events

    Science.gov (United States)

    Dunbar, P. K.; Furtney, M.; McLean, S. J.; Sweeney, A. D.

    2014-12-01

    Tsunamis have inflicted death and destruction on the coastlines of the world throughout history. The occurrence of tsunamis and the resulting effects have been collected and studied as far back as the second millennium B.C. The knowledge gained from cataloging and examining these events has led to significant changes in our understanding of tsunamis, tsunami sources, and methods to mitigate the effects of tsunamis. The most significant, not surprisingly, are often the most devastating, such as the 2011 Tohoku, Japan earthquake and tsunami. The goal of this poster is to give a brief overview of the occurrence of tsunamis and then focus specifically on several significant tsunamis. There are various criteria to determine the most significant tsunamis: the number of deaths, amount of damage, maximum runup height, had a major impact on tsunami science or policy, etc. As a result, descriptions will include some of the most costly (2011 Tohoku, Japan), the most deadly (2004 Sumatra, 1883 Krakatau), and the highest runup ever observed (1958 Lituya Bay, Alaska). The discovery of the Cascadia subduction zone as the source of the 1700 Japanese "Orphan" tsunami and a future tsunami threat to the U.S. northwest coast, contributed to the decision to form the U.S. National Tsunami Hazard Mitigation Program. The great Lisbon earthquake of 1755 marked the beginning of the modern era of seismology. Knowledge gained from the 1964 Alaska earthquake and tsunami helped confirm the theory of plate tectonics. The 1946 Alaska, 1952 Kuril Islands, 1960 Chile, 1964 Alaska, and the 2004 Banda Aceh, tsunamis all resulted in warning centers or systems being established.The data descriptions on this poster were extracted from NOAA's National Geophysical Data Center (NGDC) global historical tsunami database. Additional information about these tsunamis, as well as water level data can be found by accessing the NGDC website www.ngdc.noaa.gov/hazard/

  6. Suggestibility and negative priming: two replication studies.

    Science.gov (United States)

    David, Daniel; Brown, Richard J

    2002-07-01

    Research suggests that inhibiting the effect of irrelevant stimuli on subsequent thought and action (cognitive inhibition) may be an important component of suggestibility. Two small correlation studies were conducted to address the relationship between different aspects of suggestibility and individual differences in cognitive inhibition, operationalized as the degree of negative priming generated by to-be-ignored stimuli in a semantic categorization task. The first study found significant positive correlations between negative priming, hypnotic suggestibility, and creative imagination; a significant negative correlation was obtained between negative priming and interrogative suggestibility, demonstrating the discriminant validity of the study results. The second study replicated the correlation between negative priming and hypnotic suggestibility, using a different suggestibility measurement procedure that assessed subjective experience and hypnotic involuntariness as well as objective responses to suggestions. These studies support the notion that the ability to engage in cognitive inhibition may be an important component of hypnotic responsivity and maybe of other forms of suggestibility.

  7. Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver

    International Nuclear Information System (INIS)

    Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

    2004-01-01

    Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm 2 was obtained under the same conditions that gave 57 45 mA/cm 2 of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl - was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm 2 , sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source

  8. Responses to negative pressure surrounding the neck in anesthetized animals.

    Science.gov (United States)

    Wolin, A D; Strohl, K P; Acree, B N; Fouke, J M

    1990-01-01

    Continuous positive pressure applied at the nose has been shown to cause a decrease in upper airway resistance. The present study was designed to determine whether a similar positive transmural pressure gradient, generated by applying a negative pressure at the body surface around the neck, altered upper airway patency. Studies were performed in nine spontaneously breathing anesthetized supine dogs. Airflow was measured with a pneumotachograph mounted on an airtight muzzle placed over the nose and mouth of each animal. Upper airway pressure was measured as the differential pressure between the extrathoracic trachea and the inside of the muzzle. Upper airway resistance was monitored as an index of airway patency. Negative pressure (-2 to -20 cmH2O) was applied around the neck by using a cuirass extending from the jaw to the thorax. In each animal, increasingly negative pressures were transmitted to the airway wall in a progressive, although not linear, fashion. Decreasing the pressure produced a progressive fall in upper airway resistance, without causing a significant change in respiratory drive or respiratory timing. At -5 cmH2O pressure, there occurred a significant fall in upper airway resistance, comparable with the response of a single, intravenous injection of sodium cyanide (0.5-3.0 mg), a respiratory stimulant that produces substantial increases in respiratory drive. We conclude that upper airway resistance is influenced by the transmural pressure across the airway wall and that such a gradient can be accomplished by making the extraluminal pressure more negative.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Negative ion beam processes

    International Nuclear Information System (INIS)

    Hayward, T.D.; Lawrence, G.P.; Bentley, R.F.; Malanify, J.J.; Jackson, J.A.

    1975-06-01

    Los Alamos Scientific Laboratory fiscal year 1975 work on production of intense, very bright, negative hydrogen (H - ), ion beams and conversion of a high-energy (a few hundred MeV) negative beam into a neutral beam are described. The ion source work has used a cesium charge exchange source that has produced H - ion beams greater than or equal to 10 mA (about a factor of 10 greater than those available 1 yr ago) with a brightness of 1.4 x 10 9 A/m 2 -rad 2 (about 18 times brighter than before). The high-energy, neutral beam production investigations have included measurements of the 800-MeV H - -stripping cross section in hydrogen gas (sigma/sub -10/, tentatively 4 x 10 -19 cm 2 ), 3- to 6-MeV H - -stripping cross sections in a hydrogen plasma (sigma/sub -10/, tentatively 2 to 4 x 10 -16 cm 2 ), and the small-angle scattering that results from stripping an 800-MeV H - ion beam to a neutral (H 0 ) beam in hydrogen gas. These last measurements were interrupted by the Los Alamos Meson Physics Facility shutdown in December 1974, but should be completed early in fiscal year 1976 when the accelerator resumes operation. Small-angle scattering calculations have included hydrogen gas-stripping, plasma-stripping, and photodetachment. Calculations indicate that the root mean square angular spread of a 390-MeV negative triton (T - ) beam stripped in a plasma stripper may be as low as 0.7 μrad

  10. Non linear microtearing modes

    International Nuclear Information System (INIS)

    Garbet, X.; Mourgues, F.; Samain, A.

    1987-01-01

    Among the various instabilities which could explain the anomalous electron heat transport observed in tokamaks during additional heating, a microtearing turbulence is a reasonable candidate since it affects directly the magnetic topology. This turbulence may be described in a proper frame rotating around the majors axis by a static potential vector. In strong non linear regimes, the flow of electrons along the stochastic field lines induces a current. The point is to know whether this current can sustain the turbulence. The mechanisms of this self-consistency, involving the combined effects of the thermal diamagnetism and of the electric drift are presented here

  11. RF linear accelerators

    CERN Document Server

    Wangler, Thomas P

    2008-01-01

    Thomas P. Wangler received his B.S. degree in physics from Michigan State University, and his Ph.D. degree in physics and astronomy from the University of Wisconsin. After postdoctoral appointments at the University of Wisconsin and Brookhaven National Laboratory, he joined the staff of Argonne National Laboratory in 1966, working in the fields of experimental high-energy physics and accelerator physics. He joined the Accelerator Technology Division at Los Alamos National Laboratory in 1979, where he specialized in high-current beam physics and linear accelerator design and technology. In 2007

  12. SLAC linear collider

    International Nuclear Information System (INIS)

    Richter, B.; Bell, R.A.; Brown, K.L.

    1980-06-01

    The SLAC LINEAR COLLIDER is designed to achieve an energy of 100 GeV in the electron-positron center-of-mass system by accelerating intense bunches of particles in the SLAC linac and transporting the electron and positron bunches in a special magnet system to a point where they are focused to a radius of about 2 microns and made to collide head on. The rationale for this new type of colliding beam system is discussed, the project is described, some of the novel accelerator physics issues involved are discussed, and some of the critical technical components are described

  13. Matlab linear algebra

    CERN Document Server

    Lopez, Cesar

    2014-01-01

    MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Linear Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. In addition to giving an introduction to

  14. Testing Significance Testing

    Directory of Open Access Journals (Sweden)

    Joachim I. Krueger

    2018-04-01

    Full Text Available The practice of Significance Testing (ST remains widespread in psychological science despite continual criticism of its flaws and abuses. Using simulation experiments, we address four concerns about ST and for two of these we compare ST’s performance with prominent alternatives. We find the following: First, the 'p' values delivered by ST predict the posterior probability of the tested hypothesis well under many research conditions. Second, low 'p' values support inductive inferences because they are most likely to occur when the tested hypothesis is false. Third, 'p' values track likelihood ratios without raising the uncertainties of relative inference. Fourth, 'p' values predict the replicability of research findings better than confidence intervals do. Given these results, we conclude that 'p' values may be used judiciously as a heuristic tool for inductive inference. Yet, 'p' values cannot bear the full burden of inference. We encourage researchers to be flexible in their selection and use of statistical methods.

  15. Safety significance evaluation system

    International Nuclear Information System (INIS)

    Lew, B.S.; Yee, D.; Brewer, W.K.; Quattro, P.J.; Kirby, K.D.

    1991-01-01

    This paper reports that the Pacific Gas and Electric Company (PG and E), in cooperation with ABZ, Incorporated and Science Applications International Corporation (SAIC), investigated the use of artificial intelligence-based programming techniques to assist utility personnel in regulatory compliance problems. The result of this investigation is that artificial intelligence-based programming techniques can successfully be applied to this problem. To demonstrate this, a general methodology was developed and several prototype systems based on this methodology were developed. The prototypes address U.S. Nuclear Regulatory Commission (NRC) event reportability requirements, technical specification compliance based on plant equipment status, and quality assurance assistance. This collection of prototype modules is named the safety significance evaluation system

  16. Predicting significant torso trauma.

    Science.gov (United States)

    Nirula, Ram; Talmor, Daniel; Brasel, Karen

    2005-07-01

    Identification of motor vehicle crash (MVC) characteristics associated with thoracoabdominal injury would advance the development of automatic crash notification systems (ACNS) by improving triage and response times. Our objective was to determine the relationships between MVC characteristics and thoracoabdominal trauma to develop a torso injury probability model. Drivers involved in crashes from 1993 to 2001 within the National Automotive Sampling System were reviewed. Relationships between torso injury and MVC characteristics were assessed using multivariate logistic regression. Receiver operating characteristic curves were used to compare the model to current ACNS models. There were a total of 56,466 drivers. Age, ejection, braking, avoidance, velocity, restraints, passenger-side impact, rollover, and vehicle weight and type were associated with injury (p < 0.05). The area under the receiver operating characteristic curve (83.9) was significantly greater than current ACNS models. We have developed a thoracoabdominal injury probability model that may improve patient triage when used with ACNS.

  17. Gas revenue increasingly significant

    International Nuclear Information System (INIS)

    Megill, R.E.

    1991-01-01

    This paper briefly describes the wellhead prices of natural gas compared to crude oil over the past 70 years. Although natural gas prices have never reached price parity with crude oil, the relative value of a gas BTU has been increasing. It is one of the reasons that the total amount of money coming from natural gas wells is becoming more significant. From 1920 to 1955 the revenue at the wellhead for natural gas was only about 10% of the money received by producers. Most of the money needed for exploration, development, and production came from crude oil. At present, however, over 40% of the money from the upstream portion of the petroleum industry is from natural gas. As a result, in a few short years natural gas may become 50% of the money revenues generated from wellhead production facilities

  18. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  19. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  20. Effect of antimony on lead-acid battery negative

    International Nuclear Information System (INIS)

    Mahato, B.K.; Bullock, K.R.; Strebe, J.L.; Wilkinson, D.F.

    1985-01-01

    The role of antimony on the lead-acid battery negative in terms of its effect on charge efficiency, its effect on gassing overpotential, its interactive influence with lignin expander in controlling the charge efficiency, and its retentive behavior or purging characteristics as SbH 3 in the overcharge gas stream was investigated. Linear potential sweep (LPS) cycling of Plante-type lead electrodes were used to determine the effect of antimony on gassing overpotential and to monitor its concentration either in the active material or the exit gas stream. Results showed a significant contribution of antimony in decreasing charge efficiency and an overwhelming role of lignin expander in suppressing the effect of antimony on charge efficiency. The critical lead-electrode potential for purging antimony from the electrode is close to -1275 mV (vs. Hg/Hg 2 SO 4 )

  1. Special set linear algebra and special set fuzzy linear algebra

    OpenAIRE

    Kandasamy, W. B. Vasantha; Smarandache, Florentin; Ilanthenral, K.

    2009-01-01

    The authors in this book introduce the notion of special set linear algebra and special set fuzzy Linear algebra, which is an extension of the notion set linear algebra and set fuzzy linear algebra. These concepts are best suited in the application of multi expert models and cryptology. This book has five chapters. In chapter one the basic concepts about set linear algebra is given in order to make this book a self contained one. The notion of special set linear algebra and their fuzzy analog...

  2. Tumor significant dose

    International Nuclear Information System (INIS)

    Supe, S.J.; Nagalaxmi, K.V.; Meenakshi, L.

    1983-01-01

    In the practice of radiotherapy, various concepts like NSD, CRE, TDF, and BIR are being used to evaluate the biological effectiveness of the treatment schedules on the normal tissues. This has been accepted as the tolerance of the normal tissue is the limiting factor in the treatment of cancers. At present when various schedules are tried, attention is therefore paid to the biological damage of the normal tissues only and it is expected that the damage to the cancerous tissues would be extensive enough to control the cancer. Attempt is made in the present work to evaluate the concent of tumor significant dose (TSD) which will represent the damage to the cancerous tissue. Strandquist in the analysis of a large number of cases of squamous cell carcinoma found that for the 5 fraction/week treatment, the total dose required to bring about the same damage for the cancerous tissue is proportional to T/sup -0.22/, where T is the overall time over which the dose is delivered. Using this finding the TSD was defined as DxN/sup -p/xT/sup -q/, where D is the total dose, N the number of fractions, T the overall time p and q are the exponents to be suitably chosen. The values of p and q are adjusted such that p+q< or =0.24, and p varies from 0.0 to 0.24 and q varies from 0.0 to 0.22. Cases of cancer of cervix uteri treated between 1978 and 1980 in the V. N. Cancer Centre, Kuppuswamy Naidu Memorial Hospital, Coimbatore, India were analyzed on the basis of these formulations. These data, coupled with the clinical experience, were used for choice of a formula for the TSD. Further, the dose schedules used in the British Institute of Radiology fraction- ation studies were also used to propose that the tumor significant dose is represented by DxN/sup -0.18/xT/sup -0.06/

  3. Electrodynamic linear motor

    Energy Technology Data Exchange (ETDEWEB)

    Munehiro, H

    1980-05-29

    When driving the carriage of a printer through a rotating motor, there are problems regarding the limited accuracy of the carriage position due to rotation or contraction and ageing of the cable. In order to solve the problem, a direct drive system was proposed, in which the printer carriage is driven by a linear motor. If one wants to keep the motor circuit of such a motor compact, then the magnetic flux density in the air gap must be reduced or the motor travel must be reduced. It is the purpose of this invention to create an electrodynamic linear motor, which on the one hand is compact and light and on the other hand has a relatively high constant force over a large travel. The invention is characterised by the fact that magnetic fields of alternating polarity are generated at equal intervals in the magnetic field, and that the coil arrangement has 2 adjacent coils, whose size corresponds to half the length of each magnetic pole. A logic circuit is provided to select one of the two coils and to determine the direction of the current depending on the signals of a magnetic field sensor on the coil arrangement.

  4. Uranium chemistry: significant advances

    International Nuclear Information System (INIS)

    Mazzanti, M.

    2011-01-01

    The author reviews recent progress in uranium chemistry achieved in CEA laboratories. Like its neighbors in the Mendeleev chart uranium undergoes hydrolysis, oxidation and disproportionation reactions which make the chemistry of these species in water highly complex. The study of the chemistry of uranium in an anhydrous medium has led to correlate the structural and electronic differences observed in the interaction of uranium(III) and the lanthanides(III) with nitrogen or sulfur molecules and the effectiveness of these molecules in An(III)/Ln(III) separation via liquid-liquid extraction. Recent work on the redox reactivity of trivalent uranium U(III) in an organic medium with molecules such as water or an azide ion (N 3 - ) in stoichiometric quantities, led to extremely interesting uranium aggregates particular those involved in actinide migration in the environment or in aggregation problems in the fuel processing cycle. Another significant advance was the discovery of a compound containing the uranyl ion with a degree of oxidation (V) UO 2 + , obtained by oxidation of uranium(III). Recently chemists have succeeded in blocking the disproportionation reaction of uranyl(V) and in stabilizing polymetallic complexes of uranyl(V), opening the way to to a systematic study of the reactivity and the electronic and magnetic properties of uranyl(V) compounds. (A.C.)

  5. Meaning and significance of

    Directory of Open Access Journals (Sweden)

    Ph D Student Roman Mihaela

    2011-05-01

    Full Text Available The concept of "public accountability" is a challenge for political science as a new concept in this area in full debate and developement ,both in theory and practice. This paper is a theoretical approach of displaying some definitions, relevant meanings and significance odf the concept in political science. The importance of this concept is that although originally it was used as a tool to improve effectiveness and eficiency of public governance, it has gradually become a purpose it itself. "Accountability" has become an image of good governance first in the United States of America then in the European Union.Nevertheless,the concept is vaguely defined and provides ambiguous images of good governance.This paper begins with the presentation of some general meanings of the concept as they emerge from specialized dictionaries and ancyclopaedies and continues with the meanings developed in political science. The concept of "public accontability" is rooted in economics and management literature,becoming increasingly relevant in today's political science both in theory and discourse as well as in practice in formulating and evaluating public policies. A first conclusin that emerges from, the analysis of the evolution of this term is that it requires a conceptual clarification in political science. A clear definition will then enable an appropriate model of proving the system of public accountability in formulating and assessing public policies, in order to implement a system of assessment and monitoring thereof.

  6. Need for Linear Revitalization - Gdynia Case

    Science.gov (United States)

    Sas-Bojarska, Aleksandra

    2017-10-01

    The aim of the article is to discuss the need of defining and implementation of the linear revitalization - the new approach related to the revitalization processes. The results of the preliminary investigations indicate that this kind of revitalization seems to be an important tool supporting city management and planning, especially in cases of cities fragmentation - causing lack of physical, social, economic and ecological cohesion. The problems which may occur in such situations could be, in author’s opinion, solved with the use of linear revitalization. Linear revitalization relates to various linear city structures, which need a renewal. The article presents the idea of new attitude, character of specific actions related to degraded linear structures, draft classification, as well as the potential benefits to the city structure which could be reached due to the linear revitalization implementation. The theoretical deliberations are supplemented by the description and assessment of the chosen case study from Gdynia in Poland. The Kwiatkowskiego Route in Gdynia, playing important role in the city traffic as the external connection, creates the barrier in the city structure, causing many negative effects. Author presents specific problems related to chosen example, and the ways to solve them and to connect city structure. The main conclusion of the study is that the presented approach may be, in author’s opinion, the beginning of the discussion related to the linear revitalization, which may become an important and effective tool of sustainable city development. It may help overcoming physical barriers, and minimise functional, economic, social, mental and environmental conflicts caused by city fragmentation.

  7. Significant Radionuclides Determination

    Energy Technology Data Exchange (ETDEWEB)

    Jo A. Ziegler

    2001-07-31

    The purpose of this calculation is to identify radionuclides that are significant to offsite doses from potential preclosure events for spent nuclear fuel (SNF) and high-level radioactive waste expected to be received at the potential Monitored Geologic Repository (MGR). In this calculation, high-level radioactive waste is included in references to DOE SNF. A previous document, ''DOE SNF DBE Offsite Dose Calculations'' (CRWMS M&O 1999b), calculated the source terms and offsite doses for Department of Energy (DOE) and Naval SNF for use in design basis event analyses. This calculation reproduces only DOE SNF work (i.e., no naval SNF work is included in this calculation) created in ''DOE SNF DBE Offsite Dose Calculations'' and expands the calculation to include DOE SNF expected to produce a high dose consequence (even though the quantity of the SNF is expected to be small) and SNF owned by commercial nuclear power producers. The calculation does not address any specific off-normal/DBE event scenarios for receiving, handling, or packaging of SNF. The results of this calculation are developed for comparative analysis to establish the important radionuclides and do not represent the final source terms to be used for license application. This calculation will be used as input to preclosure safety analyses and is performed in accordance with procedure AP-3.12Q, ''Calculations'', and is subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (DOE 2000) as determined by the activity evaluation contained in ''Technical Work Plan for: Preclosure Safety Analysis, TWP-MGR-SE-000010'' (CRWMS M&O 2000b) in accordance with procedure AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''.

  8. Linearization of the Lorenz system

    International Nuclear Information System (INIS)

    Li, Chunbiao; Sprott, Julien Clinton; Thio, Wesley

    2015-01-01

    A partial and complete piecewise linearized version of the Lorenz system is proposed. The linearized versions have an independent total amplitude control parameter. Additional further linearization leads naturally to a piecewise linear version of the diffusionless Lorenz system. A chaotic circuit with a single amplitude controller is then implemented using a new switch element, producing a chaotic oscillation that agrees with the numerical calculation for the piecewise linear diffusionless Lorenz system. - Highlights: • A partial and complete piecewise linearized version of the Lorenz system are addressed. • The linearized versions have an independent total amplitude control parameter. • A piecewise linear version of the diffusionless Lorenz system is derived by further linearization. • A corresponding chaotic circuit without any multiplier is implemented for the chaotic oscillation

  9. Topics in computational linear optimization

    DEFF Research Database (Denmark)

    Hultberg, Tim Helge

    2000-01-01

    Linear optimization has been an active area of research ever since the pioneering work of G. Dantzig more than 50 years ago. This research has produced a long sequence of practical as well as theoretical improvements of the solution techniques avilable for solving linear optimization problems...... of high quality solvers and the use of algebraic modelling systems to handle the communication between the modeller and the solver. This dissertation features four topics in computational linear optimization: A) automatic reformulation of mixed 0/1 linear programs, B) direct solution of sparse unsymmetric...... systems of linear equations, C) reduction of linear programs and D) integration of algebraic modelling of linear optimization problems in C++. Each of these topics is treated in a separate paper included in this dissertation. The efficiency of solving mixed 0-1 linear programs by linear programming based...

  10. Linearization of the Lorenz system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunbiao, E-mail: goontry@126.com [School of Electronic & Information Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Engineering Technology Research and Development Center of Jiangsu Circulation Modernization Sensor Network, Jiangsu Institute of Commerce, Nanjing 211168 (China); Sprott, Julien Clinton [Department of Physics, University of Wisconsin–Madison, Madison, WI 53706 (United States); Thio, Wesley [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210 (United States)

    2015-05-08

    A partial and complete piecewise linearized version of the Lorenz system is proposed. The linearized versions have an independent total amplitude control parameter. Additional further linearization leads naturally to a piecewise linear version of the diffusionless Lorenz system. A chaotic circuit with a single amplitude controller is then implemented using a new switch element, producing a chaotic oscillation that agrees with the numerical calculation for the piecewise linear diffusionless Lorenz system. - Highlights: • A partial and complete piecewise linearized version of the Lorenz system are addressed. • The linearized versions have an independent total amplitude control parameter. • A piecewise linear version of the diffusionless Lorenz system is derived by further linearization. • A corresponding chaotic circuit without any multiplier is implemented for the chaotic oscillation.

  11. Design of a linear neutron source

    International Nuclear Information System (INIS)

    Buzarbaruah, N.; Dutta, N.J.; Bhardwaz, J.K.; Mohanty, S.R.

    2015-01-01

    Highlights: • This paper reports the design of a linear neutron source based on inertial electrostatic confinement fusion scheme. • The voltage and current that is to be applied to the grid is computed theoretically. • Neutron production rate is theoretically estimated and found to be of the order of 10 7 –10 8 neutrons/s. • Electric potential distribution and ion trajectories are studied using SIMION code. • Optimized condition for the inner grid transparency has been found out. - Abstract: In this paper, we present the design of a linear neutron source based on the concept of inertial electrostatic confinement fusion. The source mainly comprises of a concentric coaxial cylindrical grid assembly housed inside a double walled cylindrical vacuum chamber, a gas injection system, a high voltage feedthrough and a high voltage negative polarity power supply. The inner grid will be kept at a high negative potential with respect to the outer grid that will be grounded. The effect of grid transparency on electric potential distribution and ion trajectories has been studied using SIMION. A diffuse deuterium plasma will be initially created by making filament discharge and subsequently, on application of high negative voltage to the inner grid, deuterons will be accelerated towards the axis of the device. These deuterons will oscillate in the negative potential and consequently fuse in between the grids to produce neutrons. This source is expected to produce 10 7 –10 8 neutrons/s. The proposed linear neutron source will be operated both in the continuous and pulse modes and it will be utilized for a few near term applications namely fusion reactor material studies and explosive detection

  12. Do `negative' temperatures exist?

    Science.gov (United States)

    Lavenda, B. H.

    1999-06-01

    A modification of the second law is required for a system with a bounded density of states and not the introduction of a `negative' temperature scale. The ascending and descending branches of the entropy versus energy curve describe particle and hole states, having thermal equations of state that are given by the Fermi and logistic distributions, respectively. Conservation of energy requires isentropic states to be isothermal. The effect of adiabatically reversing the field is entirely mechanical because the only difference between the two states is their energies. The laws of large and small numbers, leading to the normal and Poisson approximations, characterize statistically the states of infinite and zero temperatures, respectively. Since the heat capacity also vanishes in the state of maximum disorder, the third law can be generalized in systems with a bounded density of states: the entropy tends to a constant as the temperature tends to either zero or infinity.

  13. On the linear programming bound for linear Lee codes.

    Science.gov (United States)

    Astola, Helena; Tabus, Ioan

    2016-01-01

    Based on an invariance-type property of the Lee-compositions of a linear Lee code, additional equality constraints can be introduced to the linear programming problem of linear Lee codes. In this paper, we formulate this property in terms of an action of the multiplicative group of the field [Formula: see text] on the set of Lee-compositions. We show some useful properties of certain sums of Lee-numbers, which are the eigenvalues of the Lee association scheme, appearing in the linear programming problem of linear Lee codes. Using the additional equality constraints, we formulate the linear programming problem of linear Lee codes in a very compact form, leading to a fast execution, which allows to efficiently compute the bounds for large parameter values of the linear codes.

  14. Negative incidental emotions augment fairness sensitivity.

    Science.gov (United States)

    Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

    2016-04-22

    Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals' subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation.

  15. 40 CFR 721.10094 - Decene, branched and linear.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Decene, branched and linear. 721.10094... Substances § 721.10094 Decene, branched and linear. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as decene, branched and linear (PMN P-03-272; CAS...

  16. [Stress and attitudes toward negative emotions in adolescence].

    Science.gov (United States)

    Ozawa, Eiji

    2010-12-01

    This study investigated the relationship between stress and attitudes toward negative emotions in adolescents. Adolescent students (N=1500) completed a questionnaire that measured attitudes toward negative emotions, emotional-stress reactions, and stress coping. Analysis of date yielded, two factors of the attitudes toward negative emotions: "Negative feelings about negative emotions" and "Capabilities of switching of negative emotions". In order to examine the theoretical relationships among attitudes toward negative emotions, emotional-stress reactions, and stress coping, a hypothetical model was tested by covariance structure analysis. This model predicted that students who have a high level of attitudes toward negative emotions would report enhanced problem solving which promoted stress coping. The results indicated that "Negative feelings about negative emotions" enhanced avoidable coping, and avoidable coping enhanced stress reactions. "Capabilities of switching of negative emotions" was related to a decrease of avoidable coping. Based on the results from covariance structure analysis and a multiple population analysis, the clinical significance and developmental characteristics were discussed.

  17. Introduction to linear elasticity

    CERN Document Server

    Gould, Phillip L

    2013-01-01

    Introduction to Linear Elasticity, 3rd Edition, provides an applications-oriented grounding in the tensor-based theory of elasticity for students in mechanical, civil, aeronautical, and biomedical engineering, as well as materials and earth science. The book is distinct from the traditional text aimed at graduate students in solid mechanics by introducing the subject at a level appropriate for advanced undergraduate and beginning graduate students. The author's presentation allows students to apply the basic notions of stress analysis and move on to advanced work in continuum mechanics, plasticity, plate and shell theory, composite materials, viscoelasticity and finite method analysis. This book also:  Emphasizes tensor-based approach while still distilling down to explicit notation Provides introduction to theory of plates, theory of shells, wave propagation, viscoelasticity and plasticity accessible to advanced undergraduate students Appropriate for courses following emerging trend of teaching solid mechan...

  18. Linear step drive

    International Nuclear Information System (INIS)

    Haniger, L.; Elger, R.; Kocandrle, L.; Zdebor, J.

    1986-01-01

    A linear step drive is described developed in Czechoslovak-Soviet cooperation and intended for driving WWER-1000 control rods. The functional principle is explained of the motor and the mechanical and electrical parts of the drive, power control, and the indicator of position are described. The motor has latches situated in the reactor at a distance of 3 m from magnetic armatures, it has a low structural height above the reactor cover, which suggests its suitability for seismic localities. Its magnetic circuits use counterpoles; the mechanical shocks at the completion of each step are damped using special design features. The position indicator is of a special design and evaluates motor position within ±1% of total travel. A drive diagram and the flow chart of both the control electronics and the position indicator are presented. (author) 4 figs

  19. Linear Accelerator Laboratory

    International Nuclear Information System (INIS)

    1976-01-01

    This report covers the activity of the Linear Accelerator Laboratory during the period June 1974-June 1976. The activity of the Laboratory is essentially centered on high energy physics. The main activities were: experiments performed with the colliding rings (ACO), construction of the new colliding rings and beginning of the work at higher energy (DCI), bubble chamber experiments with the CERN PS neutrino beam, counter experiments with CERN's PS and setting-up of equipment for new experiments with CERN's SPS. During this period a project has also been prepared for an experiment with the new PETRA colliding ring at Hamburg. On the other hand, intense collaboration with the LURE Laboratory, using the electron synchrotron radiation emitted by ACO and DCI, has been developed [fr

  20. HEAVY ION LINEAR ACCELERATOR

    Science.gov (United States)

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  1. Linear absorptive dielectrics

    Science.gov (United States)

    Tip, A.

    1998-06-01

    Starting from Maxwell's equations for a linear, nonconducting, absorptive, and dispersive medium, characterized by the constitutive equations D(x,t)=ɛ1(x)E(x,t)+∫t-∞dsχ(x,t-s)E(x,s) and H(x,t)=B(x,t), a unitary time evolution and canonical formalism is obtained. Given the complex, coordinate, and frequency-dependent, electric permeability ɛ(x,ω), no further assumptions are made. The procedure leads to a proper definition of band gaps in the periodic case and a new continuity equation for energy flow. An S-matrix formalism for scattering from lossy objects is presented in full detail. A quantized version of the formalism is derived and applied to the generation of Čerenkov and transition radiation as well as atomic decay. The last case suggests a useful generalization of the density of states to the absorptive situation.

  2. Quantum algorithm for linear regression

    Science.gov (United States)

    Wang, Guoming

    2017-07-01

    We present a quantum algorithm for fitting a linear regression model to a given data set using the least-squares approach. Differently from previous algorithms which yield a quantum state encoding the optimal parameters, our algorithm outputs these numbers in the classical form. So by running it once, one completely determines the fitted model and then can use it to make predictions on new data at little cost. Moreover, our algorithm works in the standard oracle model, and can handle data sets with nonsparse design matrices. It runs in time poly( log2(N ) ,d ,κ ,1 /ɛ ) , where N is the size of the data set, d is the number of adjustable parameters, κ is the condition number of the design matrix, and ɛ is the desired precision in the output. We also show that the polynomial dependence on d and κ is necessary. Thus, our algorithm cannot be significantly improved. Furthermore, we also give a quantum algorithm that estimates the quality of the least-squares fit (without computing its parameters explicitly). This algorithm runs faster than the one for finding this fit, and can be used to check whether the given data set qualifies for linear regression in the first place.

  3. Negative inferential style, emotional clarity, and life stress: integrating vulnerabilities to depression in adolescence.

    Science.gov (United States)

    Stange, Jonathan P; Alloy, Lauren B; Flynn, Megan; Abramson, Lyn Y

    2013-01-01

    Negative inferential style and deficits in emotional clarity have been identified as vulnerability factors for depression in adolescence, particularly when individuals experience high levels of life stress. However, previous research has not integrated these characteristics when evaluating vulnerability to depression. In the present study, a racially diverse community sample of 256 early adolescents (ages 12 and 13) completed a baseline visit and a follow-up visit 9 months later. Inferential style, emotional clarity, and depressive symptoms were assessed at baseline, and intervening life events and depressive symptoms were assessed at follow-up. Hierarchical linear regressions indicated that there was a significant three-way interaction between adolescents' weakest-link negative inferential style, emotional clarity, and intervening life stress predicting depressive symptoms at follow-up, controlling for initial depressive symptoms. Adolescents with low emotional clarity and high negative inferential styles experienced the greatest increases in depressive symptoms following life stress. Emotional clarity buffered against the impact of life stress on depressive symptoms among adolescents with negative inferential styles. Similarly, negative inferential styles exacerbated the impact of life stress on depressive symptoms among adolescents with low emotional clarity. These results provide evidence of the utility of integrating inferential style and emotional clarity as constructs of vulnerability in combination with life stress in the identification of adolescents at risk for depression. They also suggest the enhancement of emotional clarity as a potential intervention technique to protect against the effects of negative inferential styles and life stress on depression in early adolescence.

  4. Optimism and positive and negative feelings in parents of young children with developmental delay.

    Science.gov (United States)

    Kurtz-Nelson, E; McIntyre, L L

    2017-07-01

    Parents' positive and negative feelings about their young children influence both parenting behaviour and child problem behaviour. Research has not previously examined factors that contribute to positive and negative feelings in parents of young children with developmental delay (DD). The present study sought to examine whether optimism, a known protective factor for parents of children with DD, was predictive of positive and negative feelings for these parents. Data were collected from 119 parents of preschool-aged children with developmental delay. Two separate hierarchical linear regression analyses were conducted to determine if optimism significantly predicted positive feelings and negative feelings and whether optimism moderated relations between parenting stress and parent feelings. Increased optimism was found to predict increased positive feelings and decreased negative feelings after controlling for child problem behaviour and parenting stress. In addition, optimism was found to moderate the relation between parenting stress and positive feelings. Results suggest that optimism may impact how parents perceive their children with DD. Future research should examine how positive and negative feelings impact positive parenting behaviour and the trajectory of problem behaviour specifically for children with DD. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  5. Correlations and Non-Linear Probability Models

    DEFF Research Database (Denmark)

    Breen, Richard; Holm, Anders; Karlson, Kristian Bernt

    2014-01-01

    the dependent variable of the latent variable model and its predictor variables. We show how this correlation can be derived from the parameters of non-linear probability models, develop tests for the statistical significance of the derived correlation, and illustrate its usefulness in two applications. Under......Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations between...... certain circumstances, which we explain, the derived correlation provides a way of overcoming the problems inherent in cross-sample comparisons of the parameters of non-linear probability models....

  6. Negative cognitive errors and positive illusions for negative divorce events: predictors of children's psychological adjustment.

    Science.gov (United States)

    Mazur, E; Wolchik, S A; Sandler, I N

    1992-12-01

    This study examined the relations among negative cognitive errors regarding hypothetical negative divorce events, positive illusions about those same events, actual divorce events, and psychological adjustment in 38 8- to 12-year-old children whose parents had divorced within the previous 2 years. Children's scores on a scale of negative cognitive errors (catastrophizing, overgeneralizing, and personalizing) correlated significantly with self-reported symptoms of anxiety and self-esteem, and with maternal reports of behavior problems. Children's scores on a scale measuring positive illusions (high self-regard, illusion of personal control, and optimism for the future) correlated significantly with less self-reported aggression. Both appraisal types accounted for variance in some measures of symptomatology beyond that explained by actual events. There was no significant association between children's negative cognitive errors and positive illusions. The implications of these results for theories of negative cognitive errors and of positive illusions, as well as for future research, are discussed.

  7. Linear and non-linear amplification of high-mode perturbations at the ablation front in HiPER targets

    Energy Technology Data Exchange (ETDEWEB)

    Olazabal-Loume, M; Breil, J; Hallo, L; Ribeyre, X [CELIA, UMR 5107 Universite Bordeaux 1-CNRS-CEA, 351 cours de la Liberation, 33405 Talence (France); Sanz, J, E-mail: olazabal@celia.u-bordeaux1.f [ETSI Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)

    2011-01-15

    The linear and non-linear sensitivity of the 180 kJ baseline HiPER target to high-mode perturbations, i.e. surface roughness, is addressed using two-dimensional simulations and a complementary analysis by linear and non-linear ablative Rayleigh-Taylor models. Simulations provide an assessment of an early non-linear stage leading to a significant deformation of the ablation surface for modes of maximum linear growth factor. A design using a picket prepulse evidences an improvement in the target stability inducing a delay of the non-linear behavior. Perturbation evolution and shape, evidenced by simulations of the non-linear stage, are analyzed with existing self-consistent non-linear theory.

  8. The changes in plasma endothelin after dosing intervention in type 2 diabetes and its clinical significance

    International Nuclear Information System (INIS)

    Yang Xixiu; Sun Jinfeng; Li Lusheng; Wang Shufang; Zhao Xin

    2002-01-01

    To explore the correlation of endothelin (ET), insulin resistance and microvascular complications in type 2 diabetes, the serum concentrations of OGTT, INS, C-P and plasma ET were measured by radioimmunoassay in 30 normal subjects and 82 patients with type 2 diabetes. ET level had a linear negative correlationship with IAI. The level of ET were significantly greater in group with microangiopathy than in group without microangiopathy (P<0.01). Insulin sensitivity are strongly correlated with vascular endothelial cells. The intervention may play an important role in decreasing insulin resistance of type 2 diabetes, and it is a vascular complications

  9. Examining the interplay among negative emotionality, cognitive functioning, and attention deficit/hyperactivity disorder symptom severity.

    Science.gov (United States)

    Healey, Dione M; Marks, David J; Halperin, Jeffrey M

    2011-05-01

    Cognition and emotion, traditionally thought of as largely distinct, have recently begun to be conceptualized as dynamically linked processes that interact to influence functioning. This study investigated the moderating effects of cognitive functioning on the relationship between negative emotionality and attention deficit/hyperactivity disorder (ADHD) symptom severity. A total of 216 (140 hyperactive/inattentive; 76 typically developing) preschoolers aged 3-4 years were administered a neuropsychological test battery (i.e., NEPSY). To avoid method bias, child negative emotionality was rated by teachers (Temperament Assessment Battery for Children-Revised), and parents rated symptom severity on the ADHD Rating Scale (ADHD-RS-IV). Hierarchical Linear Regression analyses revealed that both negative emotionality and Perceptual-Motor & Executive Functions accounted for significant unique variance in ADHD symptom severity. Significant interactions indicated that when negative emotionality is low, but not high, neuropsychological functioning accounts for significant variability in ADHD symptoms, with lower functioning predicting more symptoms. Emotional and neuropsychological functioning, both individually and in combination, play a significant role in the expression of ADHD symptom severity.

  10. Computer Program For Linear Algebra

    Science.gov (United States)

    Krogh, F. T.; Hanson, R. J.

    1987-01-01

    Collection of routines provided for basic vector operations. Basic Linear Algebra Subprogram (BLAS) library is collection from FORTRAN-callable routines for employing standard techniques to perform basic operations of numerical linear algebra.

  11. Quaternion Linear Canonical Transform Application

    OpenAIRE

    Bahri, Mawardi

    2015-01-01

    Quaternion linear canonical transform (QLCT) is a generalization of the classical linear canonical transfom (LCT) using quaternion algebra. The focus of this paper is to introduce an application of the QLCT to study of generalized swept-frequency filter

  12. Recursive Algorithm For Linear Regression

    Science.gov (United States)

    Varanasi, S. V.

    1988-01-01

    Order of model determined easily. Linear-regression algorithhm includes recursive equations for coefficients of model of increased order. Algorithm eliminates duplicative calculations, facilitates search for minimum order of linear-regression model fitting set of data satisfactory.

  13. Dynamical systems and linear algebra

    OpenAIRE

    Colonius, Fritz (Prof.)

    2007-01-01

    Dynamical systems and linear algebra / F. Colonius, W. Kliemann. - In: Handbook of linear algebra / ed. by Leslie Hogben. - Boca Raton : Chapman & Hall/CRC, 2007. - S. 56,1-56,22. - (Discrete mathematics and its applications)

  14. Linear spaces: history and theory

    OpenAIRE

    Albrecht Beutelspracher

    1990-01-01

    Linear spaces belong to the most fundamental geometric and combinatorial structures. In this paper I would like to give an onerview about the theory of embedding finite linear spaces in finite projective planes.

  15. Linear versus non-linear supersymmetry, in general

    Energy Technology Data Exchange (ETDEWEB)

    Ferrara, Sergio [Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy, UniversityC.L.A.,Los Angeles, CA 90095-1547 (United States); Kallosh, Renata [SITP and Department of Physics, Stanford University,Stanford, California 94305 (United States); Proeyen, Antoine Van [Institute for Theoretical Physics, Katholieke Universiteit Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium); Wrase, Timm [Institute for Theoretical Physics, Technische Universität Wien,Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)

    2016-04-12

    We study superconformal and supergravity models with constrained superfields. The underlying version of such models with all unconstrained superfields and linearly realized supersymmetry is presented here, in addition to the physical multiplets there are Lagrange multiplier (LM) superfields. Once the equations of motion for the LM superfields are solved, some of the physical superfields become constrained. The linear supersymmetry of the original models becomes non-linearly realized, its exact form can be deduced from the original linear supersymmetry. Known examples of constrained superfields are shown to require the following LM’s: chiral superfields, linear superfields, general complex superfields, some of them are multiplets with a spin.

  16. Linear versus non-linear supersymmetry, in general

    International Nuclear Information System (INIS)

    Ferrara, Sergio; Kallosh, Renata; Proeyen, Antoine Van; Wrase, Timm

    2016-01-01

    We study superconformal and supergravity models with constrained superfields. The underlying version of such models with all unconstrained superfields and linearly realized supersymmetry is presented here, in addition to the physical multiplets there are Lagrange multiplier (LM) superfields. Once the equations of motion for the LM superfields are solved, some of the physical superfields become constrained. The linear supersymmetry of the original models becomes non-linearly realized, its exact form can be deduced from the original linear supersymmetry. Known examples of constrained superfields are shown to require the following LM’s: chiral superfields, linear superfields, general complex superfields, some of them are multiplets with a spin.

  17. A primer on linear models

    CERN Document Server

    Monahan, John F

    2008-01-01

    Preface Examples of the General Linear Model Introduction One-Sample Problem Simple Linear Regression Multiple Regression One-Way ANOVA First Discussion The Two-Way Nested Model Two-Way Crossed Model Analysis of Covariance Autoregression Discussion The Linear Least Squares Problem The Normal Equations The Geometry of Least Squares Reparameterization Gram-Schmidt Orthonormalization Estimability and Least Squares Estimators Assumptions for the Linear Mean Model Confounding, Identifiability, and Estimability Estimability and Least Squares Estimators F

  18. Microdosimetry of negative pions

    International Nuclear Information System (INIS)

    Amols, H.I.; Dicello, J.F.; Lane, T.F.

    1976-01-01

    The radiation quality of negative and positive pions of initial momentum 168MeV/c has been determined at eight different depths in a liquid phantom. The measurements were made with a 2.5cm diameter spherical proportional counter with Shonka A-150 neutron tissue equivalent plastic walls. The gas pressure in the sensitive volume was chosen to stimulate a diameter of 2μm in unit density material. Dose distributions as a function of lineal energy change slowly in the entrance and plateau regions with a dose mean lineal energy of 6-8keV/μm. Less than 3% of the dose is delivered in excess of 50keV/μm in this region. In the Bragg peak region the distributions change rapidly as a function of depth with the dose mean lineal energy increasing to 38keV/μm at the peak and to 57keV/μm just beyond the peak. On the basis of these microdosimetric data predictions of RBE and OER have been made with the use of both the theory of dual radiation action and also the delta ray theory of cell survival. The former has been used to predict biological response at low doses and the latter at high doses. A comparison is made between the two theories at intermediate doses. The results of these calculations are not inconsistant with recent biological data

  19. Negative legacy of obesity.

    Directory of Open Access Journals (Sweden)

    Kohsuke Shirakawa

    Full Text Available Obesity promotes excessive inflammation, which is associated with senescence-like changes in visceral adipose tissue (VAT and the development of type 2 diabetes (T2DM and cardiovascular diseases. We have reported that a unique population of CD44hi CD62Llo CD4+ T cells that constitutively express PD-1 and CD153 exhibit cellular senescence and cause VAT inflammation by producing large amounts of osteopontin. Weight loss improves glycemic control and reduces cardiovascular disease risk factors, but its long-term effects on cardiovascular events and longevity in obese individuals with T2DM are somewhat disappointing and not well understood. High-fat diet (HFD-fed obese mice were subjected to weight reduction through a switch to a control diet. They lost body weight and visceral fat mass, reaching the same levels as lean mice fed a control diet. However, the VAT of weight reduction mice exhibited denser infiltration of macrophages, which formed more crown-like structures compared to the VAT of obese mice kept on the HFD. Mechanistically, CD153+ PD-1+ CD4+ T cells are long-lived and not easily eliminated, even after weight reduction. Their continued presence maintains a self-sustaining chronic inflammatory loop via production of large amounts of osteopontin. Thus, we concluded that T-cell senescence is essentially a negative legacy effect of obesity.

  20. Templates for Linear Algebra Problems

    NARCIS (Netherlands)

    Bai, Z.; Day, D.; Demmel, J.; Dongarra, J.; Gu, M.; Ruhe, A.; Vorst, H.A. van der

    1995-01-01

    The increasing availability of advanced-architecture computers is having a very signicant eect on all spheres of scientic computation, including algorithm research and software development in numerical linear algebra. Linear algebra {in particular, the solution of linear systems of equations and

  1. Linearization of CIF through SOS

    NARCIS (Netherlands)

    Nadales Agut, D.E.; Reniers, M.A.; Luttik, B.; Valencia, F.

    2011-01-01

    Linearization is the procedure of rewriting a process term into a linear form, which consist only of basic operators of the process language. This procedure is interesting both from a theoretical and a practical point of view. In particular, a linearization algorithm is needed for the Compositional

  2. Linear Logic on Petri Nets

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

  3. Positive Effects of Negative Publicity: When Negative Reviews Increase Sales

    OpenAIRE

    Jonah Berger; Alan T. Sorensen; Scott J. Rasmussen

    2010-01-01

    Can negative information about a product increase sales, and if so, when? Although popular wisdom suggests that "any publicity is good publicity," prior research has demonstrated only downsides to negative press. Negative reviews or word of mouth, for example, have been found to hurt product evaluation and sales. Using a combination of econometric analysis and experimental methods, we unify these perspectives to delineate contexts under which negative publicity about a product will have posit...

  4. Linear regression in astronomy. I

    Science.gov (United States)

    Isobe, Takashi; Feigelson, Eric D.; Akritas, Michael G.; Babu, Gutti Jogesh

    1990-01-01

    Five methods for obtaining linear regression fits to bivariate data with unknown or insignificant measurement errors are discussed: ordinary least-squares (OLS) regression of Y on X, OLS regression of X on Y, the bisector of the two OLS lines, orthogonal regression, and 'reduced major-axis' regression. These methods have been used by various researchers in observational astronomy, most importantly in cosmic distance scale applications. Formulas for calculating the slope and intercept coefficients and their uncertainties are given for all the methods, including a new general form of the OLS variance estimates. The accuracy of the formulas was confirmed using numerical simulations. The applicability of the procedures is discussed with respect to their mathematical properties, the nature of the astronomical data under consideration, and the scientific purpose of the regression. It is found that, for problems needing symmetrical treatment of the variables, the OLS bisector performs significantly better than orthogonal or reduced major-axis regression.

  5. Comparison of linear and non-linear models for predicting energy expenditure from raw accelerometer data.

    Science.gov (United States)

    Montoye, Alexander H K; Begum, Munni; Henning, Zachary; Pfeiffer, Karin A

    2017-02-01

    This study had three purposes, all related to evaluating energy expenditure (EE) prediction accuracy from body-worn accelerometers: (1) compare linear regression to linear mixed models, (2) compare linear models to artificial neural network models, and (3) compare accuracy of accelerometers placed on the hip, thigh, and wrists. Forty individuals performed 13 activities in a 90 min semi-structured, laboratory-based protocol. Participants wore accelerometers on the right hip, right thigh, and both wrists and a portable metabolic analyzer (EE criterion). Four EE prediction models were developed for each accelerometer: linear regression, linear mixed, and two ANN models. EE prediction accuracy was assessed using correlations, root mean square error (RMSE), and bias and was compared across models and accelerometers using repeated-measures analysis of variance. For all accelerometer placements, there were no significant differences for correlations or RMSE between linear regression and linear mixed models (correlations: r  =  0.71-0.88, RMSE: 1.11-1.61 METs; p  >  0.05). For the thigh-worn accelerometer, there were no differences in correlations or RMSE between linear and ANN models (ANN-correlations: r  =  0.89, RMSE: 1.07-1.08 METs. Linear models-correlations: r  =  0.88, RMSE: 1.10-1.11 METs; p  >  0.05). Conversely, one ANN had higher correlations and lower RMSE than both linear models for the hip (ANN-correlation: r  =  0.88, RMSE: 1.12 METs. Linear models-correlations: r  =  0.86, RMSE: 1.18-1.19 METs; p  linear models for the wrist-worn accelerometers (ANN-correlations: r  =  0.82-0.84, RMSE: 1.26-1.32 METs. Linear models-correlations: r  =  0.71-0.73, RMSE: 1.55-1.61 METs; p  models offer a significant improvement in EE prediction accuracy over linear models. Conversely, linear models showed similar EE prediction accuracy to machine learning models for hip- and thigh

  6. Linear particle accelerator

    International Nuclear Information System (INIS)

    Richards, J.A.

    1977-01-01

    A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target

  7. Generalized Linear Covariance Analysis

    Science.gov (United States)

    Carpenter, James R.; Markley, F. Landis

    2014-01-01

    This talk presents a comprehensive approach to filter modeling for generalized covariance analysis of both batch least-squares and sequential estimators. We review and extend in two directions the results of prior work that allowed for partitioning of the state space into solve-for'' and consider'' parameters, accounted for differences between the formal values and the true values of the measurement noise, process noise, and textita priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's epoch time occurs prior to the definitive span. We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the variance sandpile'' and the sensitivity mosaic,'' and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis.

  8. Equipartitioning in linear accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1982-01-01

    Emittance growth has long been a concern in linear accelerators, as has the idea that some kind of energy balance, or equipartitioning, between the degrees of freedom, would ameliorate the growth. M. Prome observed that the average transverse and longitudinal velocity spreads tend to equalize as current in the channel is increased, while the sum of the energy in the system stays nearly constant. However, only recently have we shown that an equipartitioning requirement on a bunched injected beam can indeed produce remarkably small emittance growth. The simple set of equations leading to this condition are outlined. At the same time, Hofmann has investigated collective instabilities in transported beams and has identified thresholds and regions in parameter space where instabilities occur. Evidence is presented that shows transport system boundaries to be quite accurate in computer simulations of accelerating systems. Discussed are preliminary results of efforts to design accelerators that avoid parameter regions where emittance is affected by the instabilities identified by Hofmann. These efforts suggest that other mechanisms are present. The complicated behavior of the RFQ linac in this framework also is shown

  9. Equipartitioning in linear accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1981-01-01

    Emittance growth has long been a concern in linear accelerators, as has the idea that some kind of energy balance, or equipartitioning, between the degrees of freedom, would ameliorate the growth. M. Prome observed that the average transverse and longitudinal velocity spreads tend to equalize as current in the channel is increased, while the sum of the energy in the system stays nearly constant. However, only recently have we shown that an equipartitioning requirement on a bunched injected beam can indeed produce remarkably small emittance growth. The simple set of equations leading to this condition are outlined below. At the same time, Hofmann, using powerful analytical and computational methods, has investigated collective instabilities in transported beams and has identified thresholds and regions in parameter space where instabilities occur. This is an important generalization. Work that he will present at this conference shows that the results are essentially the same in r-z coordinates for transport systems, and evidence is presented that shows transport system boundaries to be quite accurate in computer simulations of accelerating systems also. Discussed are preliminary results of efforts to design accelerators that avoid parameter regions where emittance is affected by the instabilities identified by Hofmann. These efforts suggest that other mechanisms are present. The complicated behavior of the RFQ linac in this framework also is shown

  10. Linear induction accelerators

    International Nuclear Information System (INIS)

    Briggs, R.J.

    1986-06-01

    The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs

  11. Berkeley Proton Linear Accelerator

    Science.gov (United States)

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  12. Negated bio-events: analysis and identification

    Science.gov (United States)

    2013-01-01

    Background Negation occurs frequently in scientific literature, especially in biomedical literature. It has previously been reported that around 13% of sentences found in biomedical research articles contain negation. Historically, the main motivation for identifying negated events has been to ensure their exclusion from lists of extracted interactions. However, recently, there has been a growing interest in negative results, which has resulted in negation detection being identified as a key challenge in biomedical relation extraction. In this article, we focus on the problem of identifying negated bio-events, given gold standard event annotations. Results We have conducted a detailed analysis of three open access bio-event corpora containing negation information (i.e., GENIA Event, BioInfer and BioNLP’09 ST), and have identified the main types of negated bio-events. We have analysed the key aspects of a machine learning solution to the problem of detecting negated events, including selection of negation cues, feature engineering and the choice of learning algorithm. Combining the best solutions for each aspect of the problem, we propose a novel framework for the identification of negated bio-events. We have evaluated our system on each of the three open access corpora mentioned above. The performance of the system significantly surpasses the best results previously reported on the BioNLP’09 ST corpus, and achieves even better results on the GENIA Event and BioInfer corpora, both of which contain more varied and complex events. Conclusions Recently, in the field of biomedical text mining, the development and enhancement of event-based systems has received significant interest. The ability to identify negated events is a key performance element for these systems. We have conducted the first detailed study on the analysis and identification of negated bio-events. Our proposed framework can be integrated with state-of-the-art event extraction systems. The

  13. Random linear codes in steganography

    Directory of Open Access Journals (Sweden)

    Kamil Kaczyński

    2016-12-01

    Full Text Available Syndrome coding using linear codes is a technique that allows improvement in the steganographic algorithms parameters. The use of random linear codes gives a great flexibility in choosing the parameters of the linear code. In parallel, it offers easy generation of parity check matrix. In this paper, the modification of LSB algorithm is presented. A random linear code [8, 2] was used as a base for algorithm modification. The implementation of the proposed algorithm, along with practical evaluation of algorithms’ parameters based on the test images was made.[b]Keywords:[/b] steganography, random linear codes, RLC, LSB

  14. Negative dimensional integrals. Pt. 1

    International Nuclear Information System (INIS)

    Halliday, I.G.; Ricotta, R.M.

    1987-01-01

    We propose a new method of evaluating integrals based on negative dimensional integration. We compute Feynman graphs by considering analytic extensions. Propagators are raised to negative integer powers and integrated over negative integer dimensions. We are left with the problem of computing polynomial integrals and summing finite series. (orig.)

  15. Negative chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Smit, A.L.C.

    1979-01-01

    This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)

  16. Thermodynamics of negative absolute pressures

    International Nuclear Information System (INIS)

    Lukacs, B.; Martinas, K.

    1984-03-01

    The authors show that the possibility of negative absolute pressure can be incorporated into the axiomatic thermodynamics, analogously to the negative absolute temperature. There are examples for such systems (GUT, QCD) processing negative absolute pressure in such domains where it can be expected from thermodynamical considerations. (author)

  17. Impact scores of invasive plants are biased by disregard of environmental co-variation and non-linearity

    Directory of Open Access Journals (Sweden)

    Jan Thiele

    2011-10-01

    Full Text Available Prioritisation of high-impact species is becoming increasingly important for management of introduced species (‘neobiota’ because of their growing number of which, however, only a small fraction has substantial impacts. Impact scores for prioritising species may be affected by the type of effect model used. Recent studies have shown that environmental co-variation and non-linearity may be significant for effect models of biological invasions. Here, we test for differences in impact scores between simple and complex effect models of three invasive plant species (Heracleum mantegazzianum, Lupinus polyphyllus, Rosa rugosa.We investigated the effects of cover percentages of the invasive plants on species richness of invaded communities using both simple linear effect models (‘basic models’ and more complex linear or non-linear models including environmental co-factors (‘full models’. Then, we calculated impact scores for each invasive species as the average reduction of species richness predicted by basic and full effect models.All three non-native species had negative effects on species richness, but the full effect models also indicated significant influence of habitat types. Heracleum mantegazzianum had uniform linear effects in all habitats, while effects of L. polyphyllus interacted strongly with habitat type, and R. rugosa showed a marked non-linear relationship. Impact scores were overestimated by basic effect models for H. mantegazzianum and R. rugosa due to disregard of habitat effects and non-linearity, respectively. In contrast, impact of L. polyphyllus was underestimated by the basic model that did not account for the strong interaction of invader cover and habitat type.We conclude that simple linear models will often yield inaccurate impact scores of non-native species. Hence, effect models should consider environmental co-variation and, if necessary, non-linearity of the effects of biological invasions on native ecosystems.

  18. From neurons to circuits: linear estimation of local field potentials

    Science.gov (United States)

    Rasch, Malte; Logthetis, Nikos K.; Kreiman, Gabriel

    2010-01-01

    Extracellular physiological recordings are typically separated into two frequency bands: local field potentials (LFPs, a circuit property) and spiking multi-unit activity (MUA). There has been increased interest in LFPs due to their correlation with fMRI measurements and the possibility of studying local processing and neuronal synchrony. To further understand the biophysical origin of LFPs, we asked whether it is possible to estimate their time course based on the spiking activity from the same or nearby electrodes. We used Signal Estimation Theory to show that a linear filter operation on the activity of one/few neurons can explain a significant fraction of the LFP time course in the macaque primary visual cortex. The linear filter used to estimate the LFPs had a stereotypical shape characterized by a sharp downstroke at negative time lags and a slower positive upstroke for positve time lags. The filter was similar across neocortical regions and behavioral conditions including spontaneous activity and visual stimulation. The estimations had a spatial resolution of ~1 mm and a temporal resolution of ~200 ms. By considering a causal filter, we observed a temporal asymmetry such that the positive time lags in the filter contributed more to the LFP estimation than negative time lags. Additionally, we showed that spikes occurring within ~10 ms of spikes from nearby neurons yielded better estimation accuracies than nonsynchronous spikes. In sum, our results suggest that at least some circuit-level local properties of the field potentials can be predicted from the activity of one or a few neurons. PMID:19889990

  19. Linear Algebraic Method for Non-Linear Map Analysis

    International Nuclear Information System (INIS)

    Yu, L.; Nash, B.

    2009-01-01

    We present a newly developed method to analyze some non-linear dynamics problems such as the Henon map using a matrix analysis method from linear algebra. Choosing the Henon map as an example, we analyze the spectral structure, the tune-amplitude dependence, the variation of tune and amplitude during the particle motion, etc., using the method of Jordan decomposition which is widely used in conventional linear algebra.

  20. Impact significance determination-Pushing the boundaries

    International Nuclear Information System (INIS)

    Lawrence, David P.

    2007-01-01

    Impact significance determination practice tends to be highly variable. Too often insufficient consideration is given to good practice insights. Also, impact significance determinations are frequently narrowly defined addressing, for example, only individual, negative impacts, focusing on bio-physical impacts, and not seeking to integrate either the Precautionary Principle or sustainability. This article seeks to extend the boundaries of impact significance determination practice by providing an overview of good general impact significance practices, together with stakeholder roles and potential methods for addressing significance determination challenges. Relevant thresholds, criteria, contextual considerations and support methods are also highlighted. The analysis is then extended to address how impact significance determination practices change for positive as compared with negative impacts, for cumulative as compared with individual impacts, for socio-economic as compared with bio-physical impacts, when the Precautionary Principle is integrated into the process, and when sustainability contributions drive the EIA process and related impact significance determinations. These refinements can assist EIA practitioners in ensuring that the scope and nature of impact significance determinations reflect the broadened scope of emerging EIA requirements and practices. Suggestions are included for further refining and testing of the proposed changes to impact significance determination practice

  1. Multiple linear regression analysis

    Science.gov (United States)

    Edwards, T. R.

    1980-01-01

    Program rapidly selects best-suited set of coefficients. User supplies only vectors of independent and dependent data and specifies confidence level required. Program uses stepwise statistical procedure for relating minimal set of variables to set of observations; final regression contains only most statistically significant coefficients. Program is written in FORTRAN IV for batch execution and has been implemented on NOVA 1200.

  2. Small diameter symmetric networks from linear groups

    Science.gov (United States)

    Campbell, Lowell; Carlsson, Gunnar E.; Dinneen, Michael J.; Faber, Vance; Fellows, Michael R.; Langston, Michael A.; Moore, James W.; Multihaupt, Andrew P.; Sexton, Harlan B.

    1992-01-01

    In this note is reported a collection of constructions of symmetric networks that provide the largest known values for the number of nodes that can be placed in a network of a given degree and diameter. Some of the constructions are in the range of current potential engineering significance. The constructions are Cayley graphs of linear groups obtained by experimental computation.

  3. Best linear decoding of random mask images

    International Nuclear Information System (INIS)

    Woods, J.W.; Ekstrom, M.P.; Palmieri, T.M.; Twogood, R.E.

    1975-01-01

    In 1968 Dicke proposed coded imaging of x and γ rays via random pinholes. Since then, many authors have agreed with him that this technique can offer significant image improvement. A best linear decoding of the coded image is presented, and its superiority over the conventional matched filter decoding is shown. Experimental results in the visible light region are presented. (U.S.)

  4. Practical algorithms for linear boolean-width

    NARCIS (Netherlands)

    ten Brinke, C.B.; van Houten, F.J.P.; Bodlaender, H.L.

    2015-01-01

    In this paper, we give a number of new exact algorithms and heuristics to compute linear boolean decompositions, and experimentally evaluate these algorithms. The experimental evaluation shows that significant improvements can be made with respect to running time without increasing the width of the

  5. Practical algorithms for linear Boolean-width

    NARCIS (Netherlands)

    ten Brinke, C.B.; van Houten, F.J.P.; Bodlaender, H.L.

    2015-01-01

    In this paper, we give a number of new exact algorithms and heuristics to compute linear boolean decompositions, and experimentally evaluate these algorithms. The experimental evaluation shows that significant improvements can be made with respect to running time without increasing the width of the

  6. Robust Linear Models for Cis-eQTL Analysis.

    Science.gov (United States)

    Rantalainen, Mattias; Lindgren, Cecilia M; Holmes, Christopher C

    2015-01-01

    Expression Quantitative Trait Loci (eQTL) analysis enables characterisation of functional genetic variation influencing expression levels of individual genes. In outbread populations, including humans, eQTLs are commonly analysed using the conventional linear model, adjusting for relevant covariates, assuming an allelic dosage model and a Gaussian error term. However, gene expression data generally have noise that induces heavy-tailed errors relative to the Gaussian distribution and often include atypical observations, or outliers. Such departures from modelling assumptions can lead to an increased rate of type II errors (false negatives), and to some extent also type I errors (false positives). Careful model checking can reduce the risk of type-I errors but often not type II errors, since it is generally too time-consuming to carefully check all models with a non-significant effect in large-scale and genome-wide studies. Here we propose the application of a robust linear model for eQTL analysis to reduce adverse effects of deviations from the assumption of Gaussian residuals. We present results from a simulation study as well as results from the analysis of real eQTL data sets. Our findings suggest that in many situations robust models have the potential to provide more reliable eQTL results compared to conventional linear models, particularly in respect to reducing type II errors due to non-Gaussian noise. Post-genomic data, such as that generated in genome-wide eQTL studies, are often noisy and frequently contain atypical observations. Robust statistical models have the potential to provide more reliable results and increased statistical power under non-Gaussian conditions. The results presented here suggest that robust models should be considered routinely alongside other commonly used methodologies for eQTL analysis.

  7. Linear Programming and Network Flows

    CERN Document Server

    Bazaraa, Mokhtar S; Sherali, Hanif D

    2011-01-01

    The authoritative guide to modeling and solving complex problems with linear programming-extensively revised, expanded, and updated The only book to treat both linear programming techniques and network flows under one cover, Linear Programming and Network Flows, Fourth Edition has been completely updated with the latest developments on the topic. This new edition continues to successfully emphasize modeling concepts, the design and analysis of algorithms, and implementation strategies for problems in a variety of fields, including industrial engineering, management science, operations research

  8. EPMLR: sequence-based linear B-cell epitope prediction method using multiple linear regression.

    Science.gov (United States)

    Lian, Yao; Ge, Meng; Pan, Xian-Ming

    2014-12-19

    B-cell epitopes have been studied extensively due to their immunological applications, such as peptide-based vaccine development, antibody production, and disease diagnosis and therapy. Despite several decades of research, the accurate prediction of linear B-cell epitopes has remained a challenging task. In this work, based on the antigen's primary sequence information, a novel linear B-cell epitope prediction model was developed using the multiple linear regression (MLR). A 10-fold cross-validation test on a large non-redundant dataset was performed to evaluate the performance of our model. To alleviate the problem caused by the noise of negative dataset, 300 experiments utilizing 300 sub-datasets were performed. We achieved overall sensitivity of 81.8%, precision of 64.1% and area under the receiver operating characteristic curve (AUC) of 0.728. We have presented a reliable method for the identification of linear B cell epitope using antigen's primary sequence information. Moreover, a web server EPMLR has been developed for linear B-cell epitope prediction: http://www.bioinfo.tsinghua.edu.cn/epitope/EPMLR/ .

  9. Negative snakes in JET: evidence for negative shear

    Energy Technology Data Exchange (ETDEWEB)

    Gill, R D; Alper, B; Edwards, A W [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Pearson, D [Reading Univ. (United Kingdom)

    1994-07-01

    The signature of the negative snakes from the soft X-ray cameras is very similar to the more usual snakes except that the localised region of the snake has, compared with its surroundings, decreased rather than increased emission. Circumstances where negative snakes have been seen are reviewed. The negative snake appears as a region of increased resistance and of increased impurity density. The relationship between the shear and the current perturbation is shown, and it seem probable that the magnetic shear is reversed at the point of the negative snake, i.e. that q is decreasing with radius. 6 refs., 6 figs.

  10. Negative snakes in JET: evidence for negative shear

    International Nuclear Information System (INIS)

    Gill, R.D.; Alper, B.; Edwards, A.W.

    1994-01-01

    The signature of the negative snakes from the soft X-ray cameras is very similar to the more usual snakes except that the localised region of the snake has, compared with its surroundings, decreased rather than increased emission. Circumstances where negative snakes have been seen are reviewed. The negative snake appears as a region of increased resistance and of increased impurity density. The relationship between the shear and the current perturbation is shown, and it seem probable that the magnetic shear is reversed at the point of the negative snake, i.e. that q is decreasing with radius. 6 refs., 6 figs

  11. High ALK mRNA expression has a negative prognostic significance in rhabdomyosarcoma

    OpenAIRE

    Bonvini, P; Zin, A; Alaggio, R; Pawel, B; Bisogno, G; Rosolen, A

    2013-01-01

    Background: Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in cancer, but its clinical and functional importance remain controversial. Mutation or amplification of ALK, as well as its expression levels assessed by conventional immunohistochemistry methods, has been linked to prognosis in cancer, although with potential bias because of the semi-quantitative approaches. Herein, we measured ALK mRNA expression in rhabdomyosarcoma (RMS) and determined its clin...

  12. Prognostic significance of nuclear expression of UMP-CMP kinase in triple negative breast cancer patients

    DEFF Research Database (Denmark)

    Liu, Ning Qing; De Marchi, Tommaso; Timmermans, Annemieke

    2016-01-01

    associated to its expression through gene set enrichment analysis (GSEA). A total of 461 TNBC paraffin-embedded tissues were collected from different academic hospitals in Europe, incorporated into tissue micro-arrays (TMA), and stained for CMPK1 expression. We also collected gene expression data of 60...

  13. Pheochromocytoma with Negative Metanephrines: A Rarity and the Significance of Dopamine Secreting Tumors

    Directory of Open Access Journals (Sweden)

    Michael Bozin

    2017-05-01

    Full Text Available We describe a case of a 25-year-old female with a dopamine secreting PPGL diagnosed retrospectively with biochemical analysis. This finding resulted in change in approach to investigation and management, given their important clinical implications. There are important differences in management of dopamine secreting PPGL compared to classical noradrenaline and adrenaline-secreting PPGL. This includes the risk of peri-operative cardiovascular collapse peri-operatively with alpha/beta blockade, risk of malignancy/recurrence, and associated genetic abnormalities.

  14. LINEAR2007, Linear-Linear Interpolation of ENDF Format Cross-Sections

    International Nuclear Information System (INIS)

    2007-01-01

    1 - Description of program or function: LINEAR converts evaluated cross sections in the ENDF/B format into a tabular form that is subject to linear-linear interpolation in energy and cross section. The code also thins tables of cross sections already in that form. Codes used subsequently need thus to consider only linear-linear data. IAEA1311/15: This version include the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Linear VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 points 2 - Method of solution: Each section of data is considered separately. Each section of File 3, 23, and 27 data consists of a table of cross section versus energy with any of five interpolation laws. LINEAR will replace each section with a new table of energy versus cross section data in which the interpolation law is always linear in energy and cross section. The histogram (constant cross section between two energies) interpolation law is converted to linear-linear by substituting two points for each initial point. The linear-linear is not altered. For the log-linear, linear-log and log- log laws, the cross section data are converted to linear by an interval halving algorithm. Each interval is divided in half until the value at the middle of the interval can be approximated by linear-linear interpolation to within a given accuracy. The LINEAR program uses a multipoint fractional error thinning algorithm to minimize the size of each cross section table

  15. Elementary linear programming with applications

    CERN Document Server

    Kolman, Bernard

    1995-01-01

    Linear programming finds the least expensive way to meet given needs with available resources. Its results are used in every area of engineering and commerce: agriculture, oil refining, banking, and air transport. Authors Kolman and Beck present the basic notions of linear programming and illustrate how they are used to solve important common problems. The software on the included disk leads students step-by-step through the calculations. The Second Edition is completely revised and provides additional review material on linear algebra as well as complete coverage of elementary linear program

  16. The art of linear electronics

    CERN Document Server

    Hood, John Linsley

    2013-01-01

    The Art of Linear Electronics presents the principal aspects of linear electronics and techniques in linear electronic circuit design. The book provides a wide range of information on the elucidation of the methods and techniques in the design of linear electronic circuits. The text discusses such topics as electronic component symbols and circuit drawing; passive and active semiconductor components; DC and low frequency amplifiers; and the basic effects of feedback. Subjects on frequency response modifying circuits and filters; audio amplifiers; low frequency oscillators and waveform generato

  17. Linearity and Non-linearity of Photorefractive effect in Materials ...

    African Journals Online (AJOL)

    Linearity and Non-linearity of Photorefractive effect in Materials using the Band transport ... For low light beam intensities the change in the refractive index is ... field is spatially phase shifted by /2 relative to the interference fringe pattern, which ...

  18. The linear programming bound for binary linear codes

    NARCIS (Netherlands)

    Brouwer, A.E.

    1993-01-01

    Combining Delsarte's (1973) linear programming bound with the information that certain weights cannot occur, new upper bounds for dmin (n,k), the maximum possible minimum distance of a binary linear code with given word length n and dimension k, are derived.

  19. Linear operator inequalities for strongly stable weakly regular linear systems

    NARCIS (Netherlands)

    Curtain, RF

    2001-01-01

    We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov

  20. Linear dynamic coupling in geared rotor systems

    Science.gov (United States)

    David, J. W.; Mitchell, L. D.

    1986-01-01

    The effects of high frequency oscillations caused by the gear mesh, on components of a geared system that can be modeled as rigid discs are analyzed using linear dynamic coupling terms. The coupled, nonlinear equations of motion for a disc attached to a rotating shaft are presented. The results of a trial problem analysis show that the inclusion of the linear dynamic coupling terms can produce significant changes in the predicted response of geared rotor systems, and that the produced sideband responses are greater than the unbalanced response. The method is useful in designing gear drives for heavy-lift helicopters, industrial speed reducers, naval propulsion systems, and heavy off-road equipment.

  1. Negative social acts and pain: evidence of a workplace bullying and 5-HTT genotype interaction.

    Science.gov (United States)

    Jacobsen, Daniel Pitz; Nielsen, Morten Birkeland; Einarsen, Ståle; Gjerstad, Johannes

    2018-05-01

    Objectives Long-term exposure to systematic negative acts at work, usually labeled workplace bullying, is a prevalent problem at many workplaces. The adverse effects of such exposure may range from psychological symptoms, such as depression and anxiety to somatic ailments like cardiovascular disease and musculoskeletal complaints. In this study, we examined the relationships among exposure to negative acts, genetic variability in the 5-HTT gene SLC6A4 and pain. Methods The study was based on a nationally representative survey of 987 Norwegian employees drawn from the Norwegian Central Employee Register by Statistics Norway. Exposure to bullying in the workplace was measured with the 9-item version of the Negative Acts Questionnaire - Revised (NAQ-R) inventory. Pain was rated using an 11-point (0-10) numeric rating scale (NRS). Genotyping with regard to SLC6A4 was carried out using a combination of gel-electrophoresis and TaqMan assay. Results The data revealed a significant interaction between exposure to negative acts and the SLC6A4 genotype with regard to pain (linear regression with 5000 resamples; age, sex, tobacco use and education were included as covariates). The relationship between negative acts and pain intensity was significantly stronger for subjects with the LALA genotype than for subjects with the SLA/LALG/SLG genotype. No significant difference between subjects with the LALA genotype and SS genotype was observed. Conclusions Our data demonstrated that the relationship between bullying and pain was modified by the 5-HTT genotype, ie, genetic variation in SLC6A4. The association between negative acts and health among vulnerable individuals appeared more potent than previously reported.

  2. Linear and non-linear optics of condensed matter

    International Nuclear Information System (INIS)

    McLean, T.P.

    1977-01-01

    Part I - Linear optics: 1. General introduction. 2. Frequency dependence of epsilon(ω, k vector). 3. Wave-vector dependence of epsilon(ω, k vector). 4. Tensor character of epsilon(ω, k vector). Part II - Non-linear optics: 5. Introduction. 6. A classical theory of non-linear response in one dimension. 7. The generalization to three dimensions. 8. General properties of the polarizability tensors. 9. The phase-matching condition. 10. Propagation in a non-linear dielectric. 11. Second harmonic generation. 12. Coupling of three waves. 13. Materials and their non-linearities. 14. Processes involving energy exchange with the medium. 15. Two-photon absorption. 16. Stimulated Raman effect. 17. Electro-optic effects. 18. Limitations of the approach presented here. (author)

  3. Advanced statistics: linear regression, part I: simple linear regression.

    Science.gov (United States)

    Marill, Keith A

    2004-01-01

    Simple linear regression is a mathematical technique used to model the relationship between a single independent predictor variable and a single dependent outcome variable. In this, the first of a two-part series exploring concepts in linear regression analysis, the four fundamental assumptions and the mechanics of simple linear regression are reviewed. The most common technique used to derive the regression line, the method of least squares, is described. The reader will be acquainted with other important concepts in simple linear regression, including: variable transformations, dummy variables, relationship to inference testing, and leverage. Simplified clinical examples with small datasets and graphic models are used to illustrate the points. This will provide a foundation for the second article in this series: a discussion of multiple linear regression, in which there are multiple predictor variables.

  4. News Media Framing of Negative Campaigning

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2014-01-01

    that news coverage of negative campaigning does apply the strategic game frame to a significantly larger degree than articles covering positive campaigning. This finding has significant implications for campaigning politicians and for scholars studying campaign and media effects.......News media coverage of election campaigns is often characterized by use of the strategic game frame and a focus on politicians’ use of negative campaigning. However, the exact relationship between these two characteristics of news coverage is largely unexplored. This article theorizes that consumer...... demand and norms of journalistic independence might induce the news media outlets to cover negative campaigning with a strategic game frame. A comprehensive content analysis based on several newspaper types, several election campaigns, and several different measurements of media framing confirms...

  5. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    We consider the impact of negative attitudes against immigrants and immigration on educational choice in a search and wage bargaining model including networking. We consider two cases in terms of the importance of negative attitudes againts immigrants for high and low educated individuals and find...... that more negative attitudes against immigrants has a positive impact on education in one case and a negative impact in the other and has no impact on natives. Immigration improves employment perspectives for immigrants and thereby increases immigrant education whereas endogenous negative attitudes lead...... use Danish register data to find a signficant positive correlation between negative attitudes towards immigrants and high school attendance and find a positive impact of networking on high school attendance. In both the macro and the micro-econometric analysis we run the same regressions for natives...

  6. Negative hydrogen ion production mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Bacal, M. [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Wada, M. [School of Science and Engineering, Doshisha University, Kyoto 610-0321 (Japan)

    2015-06-15

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  7. Statistical monitoring of linear antenna arrays

    KAUST Repository

    Harrou, Fouzi

    2016-11-03

    The paper concerns the problem of monitoring linear antenna arrays using the generalized likelihood ratio (GLR) test. When an abnormal event (fault) affects an array of antenna elements, the radiation pattern changes and significant deviation from the desired design performance specifications can resulted. In this paper, the detection of faults is addressed from a statistical point of view as a fault detection problem. Specifically, a statistical method rested on the GLR principle is used to detect potential faults in linear arrays. To assess the strength of the GLR-based monitoring scheme, three case studies involving different types of faults were performed. Simulation results clearly shown the effectiveness of the GLR-based fault-detection method to monitor the performance of linear antenna arrays.

  8. Gain scheduled linear quadratic control for quadcopter

    Science.gov (United States)

    Okasha, M.; Shah, J.; Fauzi, W.; Hanouf, Z.

    2017-12-01

    This study exploits the dynamics and control of quadcopters using Linear Quadratic Regulator (LQR) control approach. The quadcopter’s mathematical model is derived using the Newton-Euler method. It is a highly manoeuvrable, nonlinear, coupled with six degrees of freedom (DOF) model, which includes aerodynamics and detailed gyroscopic moments that are often ignored in many literatures. The linearized model is obtained and characterized by the heading angle (i.e. yaw angle) of the quadcopter. The adopted control approach utilizes LQR method to track several reference trajectories including circle and helix curves with significant variation in the yaw angle. The controller is modified to overcome difficulties related to the continuous changes in the operating points and eliminate chattering and discontinuity that is observed in the control input signal. Numerical non-linear simulations are performed using MATLAB and Simulink to illustrate to accuracy and effectiveness of the proposed controller.

  9. Viscothermal Losses in Double-Negative Acoustic Metamaterials

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; García-Chocano, Victor M.; Sánchez-Dehesa, José

    2017-01-01

    The influence of losses in double-negative metamaterial slabs recently introduced by Graciá-Salgado et al. [Phys. Rev. B 88, 224305 (2013)] is comprehensively studied. Viscous and thermal losses are considered in the linearized Navier-Stokes equations with no flow. Despite the extremely low thick...

  10. [Linear growth retardation in children under five years of age: a baseline study].

    Science.gov (United States)

    Rissin, Anete; Figueiroa, José Natal; Benício, Maria Helena D'Aquino; Batista Filho, Malaquias

    2011-10-01

    The scope of this study was to describe the prevalence of, and analyze factors associated with, linear growth retardation in children. The baseline study analyzed 2040 children under the age of five, establishing a possible association between growth delay (height/age index non-binary variables, there was a positive association with roof type and number of inhabitants per room and a negative association with income per capita, mother's schooling and birth weight. The adjusted analysis also indicated water supply, visit from the community health agent, birth delivery location, internment for diarrhea, or for pneumonia and birth weight as significant variables. Several risk factors were identified for linear growth retardation pointing to the multi-causal aspects of the problem and highlighting the need for control measures by the various hierarchical government agents.

  11. Wages, Amenities and Negative Attitudes

    DEFF Research Database (Denmark)

    Waisman, Gisela; Larsen, Birthe

    We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of the attitudes on immigrants welfare. We find that attitudes towards immigrants are of importance: they both affect their labour market outcomes and their quality of life. We...... interpret the negative effect on wages as evidence of labour market discrimination. We estimate the welfare effects of negative attitudes, through their wage and local amenities, for immigrants with different levels of skills, origin, gender and age....

  12. Income, Amenities and Negative Attitudes

    DEFF Research Database (Denmark)

    Waisman, Gisela; Larsen, Birthe

    2016-01-01

    We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of negative attitudes on refugees’ utility from labour income and amenities. We find that attitudes towards immigrants are important: while they affect mainly the refugees......’ quality of life, they also affect their income. We estimate the utility effects of negative attitudes for refugees with different levels of education and gender. We also analyse how the size of the refugees’ networks relate to their quality of life and income as well as how negative attitudes towards...

  13. Energy of linear quasineutral electrostatic drift waves

    International Nuclear Information System (INIS)

    Pfirsch, D.; Correa-Restrepo, D.

    1993-01-01

    Certain kinds of nonlinear instabilities are related to the existence of negative-energy perturbations. In this paper, an exact energy expression for linear quasineutral electrostatic perturbations is derived within the framework of dissipationless multifluid theory that is valid for any geometry. Taking the mass formally as a tensor with, in general, different masses parallel and perpendicular to an ambient magnetic field allows one to treat in a convenient way different approximations such as the full dynamics and restriction to parallel dynamics or the completely adiabatic case. Application to slab configurations yields the result that the adiabatic approximation does not allow negative energy for perturbations which are perfectly localized at a mode resonant surface, whereas inclusion of the parallel dynamics does. This is in agreement with a recent numerical study of drift-wave turbulence within the framework of collisional two-fluid theory by B. Scott [Phys. Rev. Lett. 65, 3289 (1990); Phys. Fluids B 4, 2468 (1992)]. A dissipationless theory can be formulated in terms of a Lagrangian, from which the energy is immediately obtained. We start with the nonlinear theory. The theory is formulated via a Lagrangian which is written in terms of displacement vectors ξ ν (x,t) such that all constraints are taken into account. The nonlinear energy is obtained from the Lagrangian by standard methods. The procedure used is the same as that developed in a forthcoming paper by Pfirsch and Sudan [Phys. Fluids B (to be published)] for ideal nonlinear magnetohydrodynamics theory. From the exact Lagrangian one obtains the Lagrangian of the linearized theory by simple expansion to second order in ξ ν . This Lagrangian then yields the energy of the linearized theory

  14. Para-mixed linear spaces

    Directory of Open Access Journals (Sweden)

    Crasmareanu Mircea

    2017-12-01

    Full Text Available We consider the paracomplex version of the notion of mixed linear spaces introduced by M. Jurchescu in [4] by replacing the complex unit i with the paracomplex unit j, j2 = 1. The linear algebra of these spaces is studied with a special view towards their morphisms.

  15. Linear Algebra and Image Processing

    Science.gov (United States)

    Allali, Mohamed

    2010-01-01

    We use the computing technology digital image processing (DIP) to enhance the teaching of linear algebra so as to make the course more visual and interesting. Certainly, this visual approach by using technology to link linear algebra to DIP is interesting and unexpected to both students as well as many faculty. (Contains 2 tables and 11 figures.)

  16. Efficient Searching with Linear Constraints

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

    2000-01-01

    We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint. This pr...

  17. Linear Motor With Air Slide

    Science.gov (United States)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  18. Linear morphoea follows Blaschko's lines.

    Science.gov (United States)

    Weibel, L; Harper, J I

    2008-07-01

    The aetiology of morphoea (or localized scleroderma) remains unknown. It has previously been suggested that lesions of linear morphoea may follow Blaschko's lines and thus reflect an embryological development. However, the distribution of linear morphoea has never been accurately evaluated. We aimed to identify common patterns of clinical presentation in children with linear morphoea and to establish whether linear morphoea follows the lines of Blaschko. A retrospective chart review of 65 children with linear morphoea was performed. According to clinical photographs the skin lesions of these patients were plotted on to standardized head and body charts. With the aid of Adobe Illustrator a final figure was produced including an overlay of all individual lesions which was used for comparison with the published lines of Blaschko. Thirty-four (53%) patients had the en coup de sabre subtype, 27 (41%) presented with linear morphoea on the trunk and/or limbs and four (6%) children had a combination of the two. In 55 (85%) children the skin lesions were confined to one side of the body, showing no preference for either left or right side. On comparing the overlays of all body and head lesions with the original lines of Blaschko there was an excellent correlation. Our data indicate that linear morphoea follows the lines of Blaschko. We hypothesize that in patients with linear morphoea susceptible cells are present in a mosaic state and that exposure to some trigger factor may result in the development of this condition.

  19. Dynamic Linear Models with R

    CERN Document Server

    Campagnoli, Patrizia; Petris, Giovanni

    2009-01-01

    State space models have gained tremendous popularity in as disparate fields as engineering, economics, genetics and ecology. Introducing general state space models, this book focuses on dynamic linear models, emphasizing their Bayesian analysis. It illustrates the fundamental steps needed to use dynamic linear models in practice, using R package.

  20. Linear Programming across the Curriculum

    Science.gov (United States)

    Yoder, S. Elizabeth; Kurz, M. Elizabeth

    2015-01-01

    Linear programming (LP) is taught in different departments across college campuses with engineering and management curricula. Modeling an LP problem is taught in every linear programming class. As faculty teaching in Engineering and Management departments, the depth to which teachers should expect students to master this particular type of…

  1. Introduction to RF linear accelerators

    International Nuclear Information System (INIS)

    Weiss, M.

    1994-01-01

    The basic features of RF linear accelerators are described. The concept of the 'loaded cavity', essential for the synchronism wave-particle, is introduced, and formulae describing the action of electromagnetic fields on the beam are given. The treatment of intense beams is mentioned, and various existing linear accelerators are presented as examples. (orig.)

  2. Spatial Processes in Linear Ordering

    Science.gov (United States)

    von Hecker, Ulrich; Klauer, Karl Christoph; Wolf, Lukas; Fazilat-Pour, Masoud

    2016-01-01

    Memory performance in linear order reasoning tasks (A > B, B > C, C > D, etc.) shows quicker, and more accurate responses to queries on wider (AD) than narrower (AB) pairs on a hypothetical linear mental model (A -- B -- C -- D). While indicative of an analogue representation, research so far did not provide positive evidence for spatial…

  3. Linear methods in band theory

    DEFF Research Database (Denmark)

    Andersen, O. Krogh

    1975-01-01

    of Korringa-Kohn-Rostoker, linear-combination-of-atomic-orbitals, and cellular methods; the secular matrix is linear in energy, the overlap integrals factorize as potential parameters and structure constants, the latter are canonical in the sense that they neither depend on the energy nor the cell volume...

  4. Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance.

    Science.gov (United States)

    Kramer, Karen L; Veile, Amanda; Otárola-Castillo, Erik

    2016-01-01

    Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children's growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children's monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1) as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2) competition from young siblings will negatively impact child growth during the post weaning period; 3) however because of their economic value, older siblings will have a negligible effect on young children's growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children's growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children's growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance.

  5. Sibling Competition & Growth Tradeoffs. Biological vs. Statistical Significance.

    Directory of Open Access Journals (Sweden)

    Karen L Kramer

    Full Text Available Early childhood growth has many downstream effects on future health and reproduction and is an important measure of offspring quality. While a tradeoff between family size and child growth outcomes is theoretically predicted in high-fertility societies, empirical evidence is mixed. This is often attributed to phenotypic variation in parental condition. However, inconsistent study results may also arise because family size confounds the potentially differential effects that older and younger siblings can have on young children's growth. Additionally, inconsistent results might reflect that the biological significance associated with different growth trajectories is poorly understood. This paper addresses these concerns by tracking children's monthly gains in height and weight from weaning to age five in a high fertility Maya community. We predict that: 1 as an aggregate measure family size will not have a major impact on child growth during the post weaning period; 2 competition from young siblings will negatively impact child growth during the post weaning period; 3 however because of their economic value, older siblings will have a negligible effect on young children's growth. Accounting for parental condition, we use linear mixed models to evaluate the effects that family size, younger and older siblings have on children's growth. Congruent with our expectations, it is younger siblings who have the most detrimental effect on children's growth. While we find statistical evidence of a quantity/quality tradeoff effect, the biological significance of these results is negligible in early childhood. Our findings help to resolve why quantity/quality studies have had inconsistent results by showing that sibling competition varies with sibling age composition, not just family size, and that biological significance is distinct from statistical significance.

  6. Discrepancy and Disliking Do Not Induce Negative Opinion Shifts

    Science.gov (United States)

    Flache, Andreas; Mäs, Michael

    2016-01-01

    Both classical social psychological theories and recent formal models of opinion differentiation and bi-polarization assign a prominent role to negative social influence. Negative influence is defined as shifts away from the opinion of others and hypothesized to be induced by discrepancy with or disliking of the source of influence. There is strong empirical support for the presence of positive social influence (a shift towards the opinion of others), but evidence that large opinion differences or disliking could trigger negative shifts is mixed. We examine positive and negative influence with controlled exposure to opinions of other individuals in one experiment and with opinion exchange in another study. Results confirm that similarities induce attraction, but results do not support that discrepancy or disliking entails negative influence. Instead, our findings suggest a robust positive linear relationship between opinion distance and opinion shifts. PMID:27333160

  7. Introduction to generalized linear models

    CERN Document Server

    Dobson, Annette J

    2008-01-01

    Introduction Background Scope Notation Distributions Related to the Normal Distribution Quadratic Forms Estimation Model Fitting Introduction Examples Some Principles of Statistical Modeling Notation and Coding for Explanatory Variables Exponential Family and Generalized Linear Models Introduction Exponential Family of Distributions Properties of Distributions in the Exponential Family Generalized Linear Models Examples Estimation Introduction Example: Failure Times for Pressure Vessels Maximum Likelihood Estimation Poisson Regression Example Inference Introduction Sampling Distribution for Score Statistics Taylor Series Approximations Sampling Distribution for MLEs Log-Likelihood Ratio Statistic Sampling Distribution for the Deviance Hypothesis Testing Normal Linear Models Introduction Basic Results Multiple Linear Regression Analysis of Variance Analysis of Covariance General Linear Models Binary Variables and Logistic Regression Probability Distributions ...

  8. Acoustic emission linear pulse holography

    International Nuclear Information System (INIS)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-01-01

    This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction

  9. Linear and Generalized Linear Mixed Models and Their Applications

    CERN Document Server

    Jiang, Jiming

    2007-01-01

    This book covers two major classes of mixed effects models, linear mixed models and generalized linear mixed models, and it presents an up-to-date account of theory and methods in analysis of these models as well as their applications in various fields. The book offers a systematic approach to inference about non-Gaussian linear mixed models. Furthermore, it has included recently developed methods, such as mixed model diagnostics, mixed model selection, and jackknife method in the context of mixed models. The book is aimed at students, researchers and other practitioners who are interested

  10. Analysis of Nonlinear Dynamics in Linear Compressors Driven by Linear Motors

    Science.gov (United States)

    Chen, Liangyuan

    2018-03-01

    The analysis of dynamic characteristics of the mechatronics system is of great significance for the linear motor design and control. Steady-state nonlinear response characteristics of a linear compressor are investigated theoretically based on the linearized and nonlinear models. First, the influence factors considering the nonlinear gas force load were analyzed. Then, a simple linearized model was set up to analyze the influence on the stroke and resonance frequency. Finally, the nonlinear model was set up to analyze the effects of piston mass, spring stiffness, driving force as an example of design parameter variation. The simulating results show that the stroke can be obtained by adjusting the excitation amplitude, frequency and other adjustments, the equilibrium position can be adjusted by adjusting the DC input, and to make the more efficient operation, the operating frequency must always equal to the resonance frequency.

  11. Modulation of sensorimotor circuits during retrieval of negative Autobiographical Memories: Exploring the impact of personality dimensions.

    Science.gov (United States)

    Mineo, Ludovico; Concerto, Carmen; Patel, Dhaval; Mayorga, Tyrone; Chusid, Eileen; Infortuna, Carmenrita; Aguglia, Eugenio; Sarraf, Yasmin; Battaglia, Fortunato

    2018-02-01

    Autobiographical Memory (AM) retrieval refers to recollection of experienced past events. Previous Transcranial Magnetic Stimulation (TMS) studies have shown that presentation of emotional negative stimuli affects human motor cortex excitability resulting in larger motor evoked potentials (MEPs). Up to date no TMS studies have been carried out in order to investigate the effect of personal memories with negative emotional value on corticospinal excitability. In this study we hypothesized that negative AM retrieval will modulate corticomotor excitability and sensorimotor integration as determined by TMS neurophysiological parameters. Furthermore, we investigated whether TMS responses during retrieval of negative AM are associated with specific personality traits. Twelve healthy subjects were asked to recall either a negative or a neutral AM across two different days in a randomized order. During this memory retrieval, the following TMS parameters were recorded: MEPs; Short- interval intracortical inhibition (SICI) and Intracortical facilitation (ICF); Short-latency afferent inhibition (SAI) and Long- latency afferent inhibition (LAI). Personality traits were assessed by using the Big Five scale. Statistical analysis was performed using factorial ANOVAs and multiple linear regression models. When compared to retrieval of neutral AM, recollection of negative AM induced a larger increase in MEP amplitude, an increase in ICF, and a decrease in SAI. The neuroticism personality trait was a significant predictor of the MEP amplitude increase during retrieval of negative AM. Altogether these results indicate that cortical excitability and sensorimotor integration are selectively modulated by the valence of AM. These results provide the first TMS evidence that the modulatory effect of the AM retrieval is associated with specific personality traits. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Increasing negativity of age stereotypes across 200 years: evidence from a database of 400 million words.

    Science.gov (United States)

    Ng, Reuben; Allore, Heather G; Trentalange, Mark; Monin, Joan K; Levy, Becca R

    2015-01-01

    Scholars argue about whether age stereotypes (beliefs about old people) are becoming more negative or positive over time. No previous study has systematically tested the trend of age stereotypes over more than 20 years, due to lack of suitable data. Our aim was to fill this gap by investigating whether age stereotypes have changed over the last two centuries and, if so, what may be associated with this change. We hypothesized that age stereotypes have increased in negativity due, in part, to the increasing medicalization of aging. This study applied computational linguistics to the recently compiled Corpus of Historical American English (COHA), a database of 400 million words that includes a range of printed sources from 1810 to 2009. After generating a comprehensive list of synonyms for the term elderly for these years from two historical thesauri, we identified 100 collocates (words that co-occurred most frequently with these synonyms) for each of the 20 decades. Inclusion criteria for the collocates were: (1) appeared within four words of the elderly synonym, (2) referred to an old person, and (3) had a stronger association with the elderly synonym than other words appearing in the database for that decade. This yielded 13,100 collocates that were rated for negativity and medicalization. We found that age stereotypes have become more negative in a linear way over 200 years. In 1880, age stereotypes switched from being positive to being negative. In addition, support was found for two potential explanations. Medicalization of aging and the growing proportion of the population over the age of 65 were both significantly associated with the increase in negative age stereotypes. The upward trajectory of age-stereotype negativity makes a case for remedial action on a societal level.

  13. Increasing negativity of age stereotypes across 200 years: evidence from a database of 400 million words.

    Directory of Open Access Journals (Sweden)

    Reuben Ng

    Full Text Available Scholars argue about whether age stereotypes (beliefs about old people are becoming more negative or positive over time. No previous study has systematically tested the trend of age stereotypes over more than 20 years, due to lack of suitable data. Our aim was to fill this gap by investigating whether age stereotypes have changed over the last two centuries and, if so, what may be associated with this change. We hypothesized that age stereotypes have increased in negativity due, in part, to the increasing medicalization of aging. This study applied computational linguistics to the recently compiled Corpus of Historical American English (COHA, a database of 400 million words that includes a range of printed sources from 1810 to 2009. After generating a comprehensive list of synonyms for the term elderly for these years from two historical thesauri, we identified 100 collocates (words that co-occurred most frequently with these synonyms for each of the 20 decades. Inclusion criteria for the collocates were: (1 appeared within four words of the elderly synonym, (2 referred to an old person, and (3 had a stronger association with the elderly synonym than other words appearing in the database for that decade. This yielded 13,100 collocates that were rated for negativity and medicalization. We found that age stereotypes have become more negative in a linear way over 200 years. In 1880, age stereotypes switched from being positive to being negative. In addition, support was found for two potential explanations. Medicalization of aging and the growing proportion of the population over the age of 65 were both significantly associated with the increase in negative age stereotypes. The upward trajectory of age-stereotype negativity makes a case for remedial action on a societal level.

  14. Algebraic Theory of Linear Viscoelastic Nematodynamics

    International Nuclear Information System (INIS)

    Leonov, Arkady I.

    2008-01-01

    This paper consists of two parts. The first one develops algebraic theory of linear anisotropic nematic 'N-operators' build up on the additive group of traceless second rank 3D tensors. These operators have been implicitly used in continual theories of nematic liquid crystals and weakly elastic nematic elastomers. It is shown that there exists a non-commutative, multiplicative group N 6 of N-operators build up on a manifold in 6D space of parameters. Positive N-operators, which in physical applications hold thermodynamic stability constraints, do not generally form a subgroup of group N 6 . A three-parametric, commutative transversal-isotropic subgroup S 3 subset of N 6 of positive symmetric nematic operators is also briefly discussed. The special case of singular, non-negative symmetric N-operators reveals the algebraic structure of nematic soft deformation modes. The second part of the paper develops a theory of linear viscoelastic nematodynamics applicable to liquid crystalline polymer. The viscous and elastic nematic components in theory are described by using the Leslie-Ericksen-Parodi (LEP) approach for viscous nematics and de Gennes free energy for weakly elastic nematic elastomers. The case of applied external magnetic field exemplifies the occurrence of non-symmetric stresses. In spite of multi-(10) parametric character of the theory, the use of nematic operators presents it in a transparent form. When the magnetic field is absent, the theory is simplified for symmetric case with six parameters, and takes an extremely simple, two-parametric form for viscoelastic nematodynamics with possible soft deformation modes. It is shown that the linear nematodynamics is always reducible to the LEP-like equations where the coefficients are changed for linear memory functionals whose parameters are calculated from original viscosities and moduli

  15. ALPS: A Linear Program Solver

    Science.gov (United States)

    Ferencz, Donald C.; Viterna, Larry A.

    1991-01-01

    ALPS is a computer program which can be used to solve general linear program (optimization) problems. ALPS was designed for those who have minimal linear programming (LP) knowledge and features a menu-driven scheme to guide the user through the process of creating and solving LP formulations. Once created, the problems can be edited and stored in standard DOS ASCII files to provide portability to various word processors or even other linear programming packages. Unlike many math-oriented LP solvers, ALPS contains an LP parser that reads through the LP formulation and reports several types of errors to the user. ALPS provides a large amount of solution data which is often useful in problem solving. In addition to pure linear programs, ALPS can solve for integer, mixed integer, and binary type problems. Pure linear programs are solved with the revised simplex method. Integer or mixed integer programs are solved initially with the revised simplex, and the completed using the branch-and-bound technique. Binary programs are solved with the method of implicit enumeration. This manual describes how to use ALPS to create, edit, and solve linear programming problems. Instructions for installing ALPS on a PC compatible computer are included in the appendices along with a general introduction to linear programming. A programmers guide is also included for assistance in modifying and maintaining the program.

  16. Linear and quasi-linear equations of parabolic type

    CERN Document Server

    Ladyženskaja, O A; Ural′ceva, N N; Uralceva, N N

    1968-01-01

    Equations of parabolic type are encountered in many areas of mathematics and mathematical physics, and those encountered most frequently are linear and quasi-linear parabolic equations of the second order. In this volume, boundary value problems for such equations are studied from two points of view: solvability, unique or otherwise, and the effect of smoothness properties of the functions entering the initial and boundary conditions on the smoothness of the solutions.

  17. Alpins and thibos vectorial astigmatism analyses: proposal of a linear regression model between methods

    Directory of Open Access Journals (Sweden)

    Giuliano de Oliveira Freitas

    2013-10-01

    Full Text Available PURPOSE: To determine linear regression models between Alpins descriptive indices and Thibos astigmatic power vectors (APV, assessing the validity and strength of such correlations. METHODS: This case series prospectively assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted among two phacoemulsification groups: one assigned to receive AcrySof®Toric intraocular lens (IOL in both eyes and another assigned to have AcrySof Natural IOL associated with limbal relaxing incisions, also in both eyes. All patients were reevaluated postoperatively at 6 months, when refractive astigmatism analysis was performed using both Alpins and Thibos methods. The ratio between Thibos postoperative APV and preoperative APV (APVratio and its linear regression to Alpins percentage of success of astigmatic surgery, percentage of astigmatism corrected and percentage of astigmatism reduction at the intended axis were assessed. RESULTS: Significant negative correlation between the ratio of post- and preoperative Thibos APVratio and Alpins percentage of success (%Success was found (Spearman's ρ=-0.93; linear regression is given by the following equation: %Success = (-APVratio + 1.00x100. CONCLUSION: The linear regression we found between APVratio and %Success permits a validated mathematical inference concerning the overall success of astigmatic surgery.

  18. The Theory of Linear Prediction

    CERN Document Server

    Vaidyanathan, PP

    2007-01-01

    Linear prediction theory has had a profound impact in the field of digital signal processing. Although the theory dates back to the early 1940s, its influence can still be seen in applications today. The theory is based on very elegant mathematics and leads to many beautiful insights into statistical signal processing. Although prediction is only a part of the more general topics of linear estimation, filtering, and smoothing, this book focuses on linear prediction. This has enabled detailed discussion of a number of issues that are normally not found in texts. For example, the theory of vecto

  19. Correlation and simple linear regression.

    Science.gov (United States)

    Zou, Kelly H; Tuncali, Kemal; Silverman, Stuart G

    2003-06-01

    In this tutorial article, the concepts of correlation and regression are reviewed and demonstrated. The authors review and compare two correlation coefficients, the Pearson correlation coefficient and the Spearman rho, for measuring linear and nonlinear relationships between two continuous variables. In the case of measuring the linear relationship between a predictor and an outcome variable, simple linear regression analysis is conducted. These statistical concepts are illustrated by using a data set from published literature to assess a computed tomography-guided interventional technique. These statistical methods are important for exploring the relationships between variables and can be applied to many radiologic studies.

  20. Non-linear optical materials

    CERN Document Server

    Saravanan, R

    2018-01-01

    Non-linear optical materials have widespread and promising applications, but the efforts to understand the local structure, electron density distribution and bonding is still lacking. The present work explores the structural details, the electron density distribution and the local bond length distribution of some non-linear optical materials. It also gives estimation of the optical band gap, the particle size, crystallite size, and the elemental composition from UV-Visible analysis, SEM, XRD and EDS of some non-linear optical materials respectively.

  1. Optimal control linear quadratic methods

    CERN Document Server

    Anderson, Brian D O

    2007-01-01

    This augmented edition of a respected text teaches the reader how to use linear quadratic Gaussian methods effectively for the design of control systems. It explores linear optimal control theory from an engineering viewpoint, with step-by-step explanations that show clearly how to make practical use of the material.The three-part treatment begins with the basic theory of the linear regulator/tracker for time-invariant and time-varying systems. The Hamilton-Jacobi equation is introduced using the Principle of Optimality, and the infinite-time problem is considered. The second part outlines the

  2. Dose reduction of risperidone and olanzapine can improve cognitive function and negative symptoms in stable schizophrenic patients: A single-blinded, 52-week, randomized controlled study.

    Science.gov (United States)

    Zhou, Yanling; Li, Guannan; Li, Dan; Cui, Hongmei; Ning, Yuping

    2018-05-01

    The long-term effects of dose reduction of atypical antipsychotics on cognitive function and symptomatology in stable patients with schizophrenia remain unclear. We sought to determine the change in cognitive function and symptomatology after reducing risperidone or olanzapine dosage in stable schizophrenic patients. Seventy-five stabilized schizophrenic patients prescribed risperidone (≥4 mg/day) or olanzapine (≥10 mg/day) were randomly divided into a dose-reduction group ( n=37) and a maintenance group ( n=38). For the dose-reduction group, the dose of antipsychotics was reduced by 50%; for the maintenance group, the dose remained unchanged throughout the whole study. The Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, and Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery were measured at baseline, 12, 28, and 52 weeks. Linear mixed models were performed to compare the Positive and Negative Syndrome Scale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects and MATRICS Consensus Cognitive Battery scores between groups. The linear mixed model showed significant time by group interactions on the Positive and Negative Syndrome Scale negative symptoms, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, attention/vigilance, working memory and total score of MATRICS Consensus Cognitive Battery (all pNegative Syndrome Scale negative subscale, Negative Symptom Assessment-16, Rating Scale for Extrapyramidal Side Effects, speed of processing, working memory and total score of MATRICS Consensus Cognitive Battery for the dose reduction group compared with those for the maintenance group (all pnegative symptoms in patients with stabilized schizophrenia.

  3. Evolution of Wigner function in laser process under the action of linear resonance force and its application

    Science.gov (United States)

    Dao-ming, Lu

    2018-05-01

    The negativity of Wigner function (WF) is one of the important symbols of non-classical properties of light field. Therefore, it is of great significance to study the evolution of WF in dissipative process. The evolution formula of WF in laser process under the action of linear resonance force is given by virtue of thermo entangled state representation and the technique of integration within an ordered product of operator. As its application, the evolution of WF of thermal field and that of single-photon-added coherent state are discussed. The results show that the WF of thermal field maintains its original character. On the other hand, the negative region size and the depth of negativity of WF of single- photon-added coherent state decrease until it vanishes with dissipation. This shows that the non-classical property of single-photon-added coherent state is weakened, until it disappears with dissipation time increasing.

  4. Backscattering and negative polarization of agglomerate particles.

    Science.gov (United States)

    Zubko, Evgenij; Shkuratov, Yuriy; Hart, Matthew; Eversole, Jay; Videen, Gorden

    2003-09-01

    We used the discrete dipole approximation to study the backscattering of agglomerate particles consisting of oblong monomers. We varied the aspect ratio of the monomers from approximately 1 (sphere) to 4, while we kept the total particle volume equivalent to that of an x = 10 sphere for m = 1.59 + i0 and 1.50 + i0 and considered two values of agglomerate packing density: rho = 0.25 and rho = 0.1. We found that these particles do not display a prominent brightness opposition effect but do produce significant negative polarization over a range of near-backscattering angles. Increasing the monomers' aspect ratio can make the negative polarization much more prominent. We have noted also that decreasing m and p can reduce the amplitude of the negative polarization for these particles.

  5. Cellular Automata Rules and Linear Numbers

    OpenAIRE

    Nayak, Birendra Kumar; Sahoo, Sudhakar; Biswal, Sagarika

    2012-01-01

    In this paper, linear Cellular Automta (CA) rules are recursively generated using a binary tree rooted at "0". Some mathematical results on linear as well as non-linear CA rules are derived. Integers associated with linear CA rules are defined as linear numbers and the properties of these linear numbers are studied.

  6. Decomposing the effects of negative framing in linear public goods games.

    OpenAIRE

    Cox, C.

    2015-01-01

    I examine two dimensions of framing in public goods games: Contributing vs. Taking and Gains vs. Losses. I find decreased cooperation under the Taking frame, but not under the Loss frame. This framing effect is stronger for men than women.

  7. An introduction to linear algebra

    CERN Document Server

    Mirsky, L

    2003-01-01

    Rigorous, self-contained coverage of determinants, vectors, matrices and linear equations, quadratic forms, more. Elementary, easily readable account with numerous examples and problems at the end of each chapter.

  8. CLIC: developing a linear collider

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    Compact Linear Collider (CLIC) is a CERN project to provide high-energy electron-positron collisions. Instead of conventional radio-frequency klystrons, CLIC will use a low-energy, high-intensity primary beam to produce acceleration.

  9. 1988 linear accelerator conference proceedings

    International Nuclear Information System (INIS)

    1989-06-01

    This report contains papers presented at the 1988 Linear Accelerator Conference. A few topics covered are beam dynamics; beam transport; superconducting components; free electron lasers; ion sources; and klystron research

  10. Linear Methods for Image Interpolation

    OpenAIRE

    Pascal Getreuer

    2011-01-01

    We discuss linear methods for interpolation, including nearest neighbor, bilinear, bicubic, splines, and sinc interpolation. We focus on separable interpolation, so most of what is said applies to one-dimensional interpolation as well as N-dimensional separable interpolation.

  11. Ada Linear-Algebra Program

    Science.gov (United States)

    Klumpp, A. R.; Lawson, C. L.

    1988-01-01

    Routines provided for common scalar, vector, matrix, and quaternion operations. Computer program extends Ada programming language to include linear-algebra capabilities similar to HAS/S programming language. Designed for such avionics applications as software for Space Station.

  12. Acoustic emission linear pulse holography

    Science.gov (United States)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-10-25

    This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

  13. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    , the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper......This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  14. Functionalized linear and cyclic polyolefins

    Energy Technology Data Exchange (ETDEWEB)

    Tuba, Robert; Grubbs, Robert H.

    2018-02-13

    This invention relates to methods and compositions for preparing linear and cyclic polyolefins. More particularly, the invention relates to methods and compositions for preparing functionalized linear and cyclic polyolefins via olefin metathesis reactions. Polymer products produced via the olefin metathesis reactions of the invention may be utilized for a wide range of materials applications. The invention has utility in the fields of polymer and materials chemistry and manufacture.

  15. Some new ternary linear codes

    Directory of Open Access Journals (Sweden)

    Rumen Daskalov

    2017-07-01

    Full Text Available Let an $[n,k,d]_q$ code be a linear code of length $n$, dimension $k$ and minimum Hamming distance $d$ over $GF(q$. One of the most important problems in coding theory is to construct codes with optimal minimum distances. In this paper 22 new ternary linear codes are presented. Two of them are optimal. All new codes improve the respective lower bounds in [11].

  16. Explorative methods in linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different feat...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression....

  17. Polarized Electrons for Linear Colliders

    International Nuclear Information System (INIS)

    Clendenin, J.

    2004-01-01

    Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%

  18. LINEAR AND NON-LINEAR ANALYSES OF CABLE-STAYED STEEL FRAME SUBJECTED TO SEISMIC ACTIONS

    Directory of Open Access Journals (Sweden)

    Marko Đuran

    2017-01-01

    Full Text Available In this study, linear and non-linear dynamic analyses of a cable-stayed steel frame subjected to seismic actions are performed. The analyzed cable-stayed frame is the main supporting structure of a wide-span sports hall. Since the complex dynamic behavior of cable-stayed structures results in significant geometric nonlinearity, a nonlinear time history analysis is conducted. As a reference, an analysis using the European standard approach, the so-called linear modal response spectrum method, is also performed. The analyses are conducted for different seismic actions considering dependence on the response spectrums for various ground types and the corresponding artificially generated accelerograms. Despite fundamental differences between the two analyses, results indicate that the modal response spectrum analysis is surprisingly consistent with the internal forces and bending moment distributions of the nonlinear time history analysis. However, significantly smaller values of bending moments, internal forces, and displacements are obtained with the response spectrum analysis.

  19. Linear induction accelerator for heavy ions

    International Nuclear Information System (INIS)

    Keefe, D.

    1976-01-01

    There is considerable recent interest in the use of high energy heavy ions to irradiate deuterium-tritium pellets in a reactor vessel to constitute a power source at the level of 1 GW or more. Various accelerator configurations involving storage rings have been suggested. This paper discusses how the technology of linear induction accelerators - well known to be matched to high current and short pulse length - may offer significant advantages for this application. (author)

  20. Recent negative ion source developments

    International Nuclear Information System (INIS)

    Alton, G.D.

    1978-01-01

    This report describes recent results obtained from studies associated with the development of negative ion sources which utilize sputtering in a diffuse cesium plasma as a means of ion beam generation. Data are presented which relate negative ion yield and important operational parameters such as cesium oven temperature and sputter probe voltage from each of the following sources: (1) A source based in principle according to the University of Aarhus design and (2) an axial geometry source. The important design aspects of the sources are given--along with a list of the negative ion intensities observed to date. Also a qualitative description and interpretation of the negative ion generation mechanism in sources which utilize sputtering in the presence of cesium is given

  1. Variable-energy drift-tube linear accelerator

    Science.gov (United States)

    Swenson, Donald A.; Boyd, Jr., Thomas J.; Potter, James M.; Stovall, James E.

    1984-01-01

    A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

  2. Negative Mood Increases Selective Attention to Negatively Valenced Body Parts in Female Adolescents with Anorexia Nervosa.

    Directory of Open Access Journals (Sweden)

    Jennifer Svaldi

    Full Text Available Previous research has yielded evidence of increased attentional processing of negatively valenced body parts in women with anorexia nervosa (AN, especially for those with high depressive symptomatology. The present study extended previous research by implementing an experimental mood manipulation.In a within-subjects design, female adolescents with AN (n = 12 and an age matched female control group (CG; n = 12 were given a negative and a positive mood induction at a one-week interval. After each mood induction, participants underwent a 3-min mirror exposure, while their eye movements were recorded.After the positive mood induction, both AN and CG participants displayed longer and more frequent gazes towards their self-defined most ugly relative to their self-defined most beautiful body part. However, after the negative mood induction, only females with AN were characterized by increased attention to their most ugly compared to their most beautiful body part, while CG participants' attention distribution was balanced. Furthermore, in the negative (but not in the positive mood induction condition gaze frequency and duration towards the most ugly body part was significantly stronger in the AN group relative to the CG.The results emphasize the role of negative mood in the maintenance of pathological information processing of the self-body. This increased body-related negativity-bias during negative mood may lead to the persistence and aggravation of AN patients' body image disturbance.

  3. Ferroelectric Negative Capacitance Domain Dynamics

    OpenAIRE

    Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

    2017-01-01

    Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr$_{0.2}$Ti$_{0.8}$)O$_3$ capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transien...

  4. Negative magnetic relaxation in superconductors

    Directory of Open Access Journals (Sweden)

    Krasnoperov E.P.

    2013-01-01

    Full Text Available It was observed that the trapped magnetic moment of HTS tablets or annuli increases in time (negative relaxation if they are not completely magnetized by a pulsed magnetic field. It is shown, in the framework of the Bean critical-state model, that the radial temperature gradient appearing in tablets or annuli during a pulsed field magnetization can explain the negative magnetic relaxation in the superconductor.

  5. SM-1 negative ion source

    International Nuclear Information System (INIS)

    Huang Zhenjun; Wang Jianzhen

    1987-01-01

    The working principle and characteristics of SM-1 Negative Ion Source is mainly introduced. In the instrument, there is a device to remove O 3 . This instrument can keep high density of negative ions which is generated by the electrical coronas setting out electricity at negative high voltage and can remove the O 3 component which is harmful to the human body. The density of negative ions is higher than 2.5 x 10 6 p./cm 3 while that of O 3 components is less than 1 ppb at the distance of 50 cm from the panel of the instrument. The instrument sprays negative ions automatically without the help of electric fan, so it works noiselessly. It is widely used in national defence, industry, agriculture, forestry, stock raising, sidelines and in the places with an equipment of low density of negative ion or high concentration of O 3 components. Besides, the instrument may also be used to treat diseases, to prevent against rot, to arrest bacteria, to purify air and so on

  6. Ferroelectric negative capacitance domain dynamics

    Science.gov (United States)

    Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

    2018-05-01

    Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transient negative capacitance is shown to originate from reverse domain nucleation and unrestricted domain growth. However, with the onset of domain coalescence, the capacitance becomes positive again. The persistence of the negative capacitance state is therefore limited by the speed of domain wall motion. By changing the applied electric field, capacitor area or external resistance, this domain wall velocity can be varied predictably over several orders of magnitude. Additionally, detailed insights into the intrinsic material properties of the ferroelectric are obtainable through these measurements. A new method for reliable extraction of the average negative capacitance of the ferroelectric is presented. Furthermore, a simple analytical model is developed, which accurately describes the negative capacitance transient time as a function of the material properties and the experimental boundary conditions.

  7. Emotional episodes in the everyday lives of people with schizophrenia: the role of intrinsic motivation and negative symptoms.

    Science.gov (United States)

    McCormick, Bryan P; Snethen, Gretchen; Lysaker, Paul H

    2012-12-01

    Research on emotional experience has indicated that subjects with schizophrenia experience less positive, and more negative emotional experience than non-psychiatric subjects in natural settings. Differences in the experience of emotion may result from differences in experiences such that everyday activities may evoke emotions. The purpose of this study was to identify if everyday experience of competence and autonomy were related to positive and negative emotion. Adults with schizophrenia spectrum disorders were recruited from day treatment programs (N=45). Data were collected using experience-sampling methods. A number of subjects failed to meet data adequacy (N=13) but did not differ from retained subjects (N=32) in symptoms or cognition. Positive and negative emotion models were analyzed using hierarchical linear modeling Everyday activities were characterized by those reported as easily accomplished and requiring at most moderate talents. Positive emotional experiences were stronger than negative emotional experiences. The majority of variance in positive and negative emotion existed between persons. Negative symptoms were significantly related to positive emotion, but not negative emotion. The perception that motivation for activity was external to subjects (e.g. wished they were doing something else) was related to decreased positive emotion and enhanced negative emotion. Activities that required more exertion for activities was related to enhanced positive emotion, whereas activities that subjects reported they wanted to do was associated with reduced negative emotion. The implications of this study are that everyday experiences of people with schizophrenia do affect emotional experience and that management of experience to enhance positive emotion may have therapeutic benefits. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Publication Trend of Clinical Trials with Negative Results Funded by Pharmaceutical Industries for the 2007-2012 Period

    Directory of Open Access Journals (Sweden)

    Evert A. Jiménez-Cotes

    2015-01-01

    Full Text Available Abstract: Objective: To evaluate the results of clinical trials financed by the pharmaceutical industries during the period 2007-2012 in a general medical journal. Materials and methods: We performed an observational cross sectional study where originals clinical trials financed by the pharmaceutical industry published between 2007 and 2012 in the journal The New England Journal of Medicine (http://www.nejm.org were reviewed. Trend Chi2 test was used to evaluate the results of studies over the years. A database was created with different variables, identifying the number of publications and the period of greater publishing negatives studies, as well as the medical specialty and pharmaceutical industry funding. Results: 321 clinical trials were analyzed. The Odds Ratio was calculated for each year evaluated, finding a Chi2 of linear trend in negatives studies of 2.91 with value p 0.08 and positive studies of 1.16 with value p 0.28. It was found that in the period 2007-2009 123 studies were published, 40 % of which presented negative results; unlike the 2010-2012 period in which 198 clinical trials where published, 142 of them, showed positive results, OR 1.68, 95 % CI (1.02-2.78 value p 0.03. The highest figures of negative results were published in 2007: 44.7 %. Conclusions: A progressive decrease in the number of publications with annual general negative results has been observed. A statistically significant difference in the publication of negative studies per year was not found between the periods 2007-2012. The medical specialty that showed the largest number of total and negative publications in both periods was cardiology. The pharmaceutical industry that sponsored most total clinical trials with negative results in both periods did so through Merck, Glaxo SmithKline, and Sanofi-Aventis. 50% of neurology publications showed negative results.

  9. Primordial black holes in linear and non-linear regimes

    Energy Technology Data Exchange (ETDEWEB)

    Allahyari, Alireza; Abolhasani, Ali Akbar [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Firouzjaee, Javad T., E-mail: allahyari@physics.sharif.edu, E-mail: j.taghizadeh.f@ipm.ir [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2017-06-01

    We revisit the formation of primordial black holes (PBHs) in the radiation-dominated era for both linear and non-linear regimes, elaborating on the concept of an apparent horizon. Contrary to the expectation from vacuum models, we argue that in a cosmological setting a density fluctuation with a high density does not always collapse to a black hole. To this end, we first elaborate on the perturbation theory for spherically symmetric space times in the linear regime. Thereby, we introduce two gauges. This allows to introduce a well defined gauge-invariant quantity for the expansion of null geodesics. Using this quantity, we argue that PBHs do not form in the linear regime irrespective of the density of the background. Finally, we consider the formation of PBHs in non-linear regimes, adopting the spherical collapse picture. In this picture, over-densities are modeled by closed FRW models in the radiation-dominated era. The difference of our approach is that we start by finding an exact solution for a closed radiation-dominated universe. This yields exact results for turn-around time and radius. It is important that we take the initial conditions from the linear perturbation theory. Additionally, instead of using uniform Hubble gauge condition, both density and velocity perturbations are admitted in this approach. Thereby, the matching condition will impose an important constraint on the initial velocity perturbations δ {sup h} {sub 0} = −δ{sub 0}/2. This can be extended to higher orders. Using this constraint, we find that the apparent horizon of a PBH forms when δ > 3 at turn-around time. The corrections also appear from the third order. Moreover, a PBH forms when its apparent horizon is outside the sound horizon at the re-entry time. Applying this condition, we infer that the threshold value of the density perturbations at horizon re-entry should be larger than δ {sub th} > 0.7.

  10. Non-linear direct effects of acid rain on leaf photosynthetic rate of terrestrial plants.

    Science.gov (United States)

    Dong, Dan; Du, Enzai; Sun, Zhengzhong; Zeng, Xuetong; de Vries, Wim

    2017-12-01

    Anthropogenic emissions of acid precursors have enhanced global occurrence of acid rain, especially in East Asia. Acid rain directly suppresses leaf function by eroding surface waxes and cuticle and leaching base cations from mesophyll cells, while the simultaneous foliar uptake of nitrates in rainwater may directly benefit leaf photosynthesis and plant growth, suggesting a non-linear direct effect of acid rain. By synthesizing data from literature on acid rain exposure experiments, we assessed the direct effects of acid rain on leaf photosynthesis across 49 terrestrial plants in China. Our results show a non-linear direct effect of acid rain on leaf photosynthetic rate, including a neutral to positive effect above pH 5.0 and a negative effect below that pH level. The acid rain sensitivity of leaf photosynthesis showed no significant difference between herbs and woody species below pH 5.0, but the impacts above that pH level were strongly different, resulting in a significant increase in leaf photosynthetic rate of woody species and an insignificant effect on herbs. Our analysis also indicates a positive effect of the molar ratio of nitric versus sulfuric acid in the acid solution on leaf photosynthetic rate. These findings imply that rainwater acidity and the composition of acids both affect the response of leaf photosynthesis and therefore result in a non-linear direct effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Linear Invariant Tensor Interpolation Applied to Cardiac Diffusion Tensor MRI

    Science.gov (United States)

    Gahm, Jin Kyu; Wisniewski, Nicholas; Kindlmann, Gordon; Kung, Geoffrey L.; Klug, William S.; Garfinkel, Alan; Ennis, Daniel B.

    2015-01-01

    Purpose Various methods exist for interpolating diffusion tensor fields, but none of them linearly interpolate tensor shape attributes. Linear interpolation is expected not to introduce spurious changes in tensor shape. Methods Herein we define a new linear invariant (LI) tensor interpolation method that linearly interpolates components of tensor shape (tensor invariants) and recapitulates the interpolated tensor from the linearly interpolated tensor invariants and the eigenvectors of a linearly interpolated tensor. The LI tensor interpolation method is compared to the Euclidean (EU), affine-invariant Riemannian (AI), log-Euclidean (LE) and geodesic-loxodrome (GL) interpolation methods using both a synthetic tensor field and three experimentally measured cardiac DT-MRI datasets. Results EU, AI, and LE introduce significant microstructural bias, which can be avoided through the use of GL or LI. Conclusion GL introduces the least microstructural bias, but LI tensor interpolation performs very similarly and at substantially reduced computational cost. PMID:23286085

  12. [Study on retention and stability of linear occlusal complete dentures].

    Science.gov (United States)

    Zhang, Ping; Xu, Jun

    2003-01-01

    To learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force. Static retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire. Linear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures. Linear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.

  13. Linear and non-linear stability analysis for finite difference discretizations of high-order Boussinesq equations

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Bingham, Harry B.; Madsen, Per A.

    2004-01-01

    of rotational and irrotational formulations in two horizontal dimensions provides evidence that the irrotational formulation has significantly better stability properties when the deep-water non-linearity is high, particularly on refined grids. Computation of matrix pseudospectra shows that the system is only...... insight into the numerical behaviour of this rather complicated system of non-linear PDEs....

  14. Positive and Negative Affect More Concurrent among Blacks than Whites.

    Science.gov (United States)

    Lankarani, Maryam Moghani; Assari, Shervin

    2017-08-01

    While positive and negative affect are inversely linked, people may experience and report both positive and negative emotions simultaneously. However, it is unknown if race alters the magnitude of the association between positive and negative affect. The current study compared Black and White Americans for the association between positive and negative affect. We used data from MIDUS (Midlife in the United States), a national study of Americans with an age range of 25 to 75. A total number of 7108 individuals were followed for 10 years from 1995 to 2004. Positive and negative affect was measured at baseline (1995) and follow-up (2004). Demographic (age and gender), socioeconomic (education and income) as well as health (self-rated health, chronic medical conditions, and body mass index) factors measured at baseline were covariates. A series of linear regressions were used to test the moderating effect of race on the reciprocal association between positive and negative affect at baseline and over time, net of covariates. In the pooled sample, positive and negative affect showed inverse correlation at baseline and over time, net of covariates. Blacks and Whites differed in the magnitude of the association between positive and negative affect, with weaker inverse associations among Blacks compared to Whites, beyond all covariates. Weaker reciprocal association between positive and negative affect in Blacks compared to Whites has implications for cross-racial measurement of affect and mood, including depression. Depression screening programs should be aware that race alters the concordance between positive and negative affect domains and that Blacks endorse higher levels of positive affect compared to Whites in the presence of high negative affect.

  15. Impact significance determination-Designing an approach

    International Nuclear Information System (INIS)

    Lawrence, David P.

    2007-01-01

    The question of how best to go about determining the significance of impacts has, to date, only been addressed in a partial and preliminary way. The assumption tends to be made that it is either only necessary to provide explicit, justified reasons for a judgment about significance and/or to explicitly apply a prescribed procedure-a procedure usually involving the staged application of thresholds and/or criteria. The detailed attributes, strengths and limitations of such approaches and possible alternative approaches have yet to be explored systematically. This article addresses these deficiencies by analyzing the characteristics, specific methods and positive and negative tendencies of three general impact significance determination approaches-the technical approach, the collaborative approach and the reasoned argumentation approach. A range of potential composite approaches are also described. With an enhanced understanding of these approaches, together with potential combinations, EIA practitioners and other EIA participants can be in a better position to select an approach appropriate to their needs, to reinforce the positive tendencies and offset the negative tendencies of the selected approach and to combine the best qualities of more than one approach

  16. The free energy principle, negative energy modes, and stability

    International Nuclear Information System (INIS)

    Morrison, P.J.; Kotschenreuther, M.

    1990-01-01

    This paper is concerned with instability of equilibria of Hamiltonian, fluid and plasma dynamical systems. Usually the dynamical equilibrium of interest is not the state of thermodynamic equilibrium, and does not correspond to a free energy minimum. The relaxation of this type of equilibrium is conventionally considered to be initiated by linear instability. However, there are many cases where linear instability is not present, but the equilibrium is nonlinearly unstable to arbitrarily small perturbations. This paper is about general free energy expressions for determining the presence of linear or nonlinear instabilities. These expressions are simple and practical, and can be obtained for all equilibria of all ideal fluid and plasma models. By free energy, we mean the energy change upon perturbations of the equilibrium that respect dynamical phase space constraints. This quantity is measured by a self-adjoint quadratic form, called δ 2 F. The free energy can result in instability when δ 2 F is indefinite; i.e. there exist accessible perturbations that lower the free energy of the system. A primary purpose of this paper is to tie together three manifestations of what we will refer to as negative energy modes. The first is the conventional plasma physics notion of negative energy mode that is based on the definition of the energy in a homogeneous dielectric medium. A negative energy mode is a normal mode of the medium (plasma) that possesses negative dielectric energy. The second manifestation occurs in finite degree-of-freedom Hamiltonian normal form theory. The quadratic part of a Hamiltonian in the vicinity of an equilibrium point, which possesses only distinct oscillatory eigenvalues, has an invariant signature. Thus in cases where the quadratic form is indefinite, it is natural to refer to the modes corresponding to the negative signature as negative energy modes

  17. The linear-non-linear frontier for the Goldstone Higgs

    International Nuclear Information System (INIS)

    Gavela, M.B.; Saa, S.; Kanshin, K.; Machado, P.A.N.

    2016-01-01

    The minimal SO(5)/SO(4) σ-model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, enjoying a (pseudo) Nambu-Goldstone-boson ancestry. Varying the σ mass allows one to sweep from the perturbative regime to the customary non-linear implementations. The low-energy benchmark effective non-linear Lagrangian for bosons and fermions is obtained, determining as well the operator coefficients including linear corrections. At first order in the latter, three effective bosonic operators emerge which are independent of the explicit soft breaking assumed. The Higgs couplings to vector bosons and fermions turn out to be quite universal: the linear corrections are proportional to the explicit symmetry-breaking parameters. Furthermore, we define an effective Yukawa operator which allows a simple parametrization and comparison of different heavy-fermion ultraviolet completions. In addition, one particular fermionic completion is explored in detail, obtaining the corresponding leading low-energy fermionic operators. (orig.)

  18. Advanced statistics: linear regression, part II: multiple linear regression.

    Science.gov (United States)

    Marill, Keith A

    2004-01-01

    The applications of simple linear regression in medical research are limited, because in most situations, there are multiple relevant predictor variables. Univariate statistical techniques such as simple linear regression use a single predictor variable, and they often may be mathematically correct but clinically misleading. Multiple linear regression is a mathematical technique used to model the relationship between multiple independent predictor variables and a single dependent outcome variable. It is used in medical research to model observational data, as well as in diagnostic and therapeutic studies in which the outcome is dependent on more than one factor. Although the technique generally is limited to data that can be expressed with a linear function, it benefits from a well-developed mathematical framework that yields unique solutions and exact confidence intervals for regression coefficients. Building on Part I of this series, this article acquaints the reader with some of the important concepts in multiple regression analysis. These include multicollinearity, interaction effects, and an expansion of the discussion of inference testing, leverage, and variable transformations to multivariate models. Examples from the first article in this series are expanded on using a primarily graphic, rather than mathematical, approach. The importance of the relationships among the predictor variables and the dependence of the multivariate model coefficients on the choice of these variables are stressed. Finally, concepts in regression model building are discussed.

  19. The linear-non-linear frontier for the Goldstone Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Gavela, M.B.; Saa, S. [IFT-UAM/CSIC, Universidad Autonoma de Madrid, Departamento de Fisica Teorica y Instituto de Fisica Teorica, Madrid (Spain); Kanshin, K. [Universita di Padova, Dipartimento di Fisica e Astronomia ' G. Galilei' , Padua (Italy); INFN, Padova (Italy); Machado, P.A.N. [IFT-UAM/CSIC, Universidad Autonoma de Madrid, Departamento de Fisica Teorica y Instituto de Fisica Teorica, Madrid (Spain); Fermi National Accelerator Laboratory, Theoretical Physics Department, Batavia, IL (United States)

    2016-12-15

    The minimal SO(5)/SO(4) σ-model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, enjoying a (pseudo) Nambu-Goldstone-boson ancestry. Varying the σ mass allows one to sweep from the perturbative regime to the customary non-linear implementations. The low-energy benchmark effective non-linear Lagrangian for bosons and fermions is obtained, determining as well the operator coefficients including linear corrections. At first order in the latter, three effective bosonic operators emerge which are independent of the explicit soft breaking assumed. The Higgs couplings to vector bosons and fermions turn out to be quite universal: the linear corrections are proportional to the explicit symmetry-breaking parameters. Furthermore, we define an effective Yukawa operator which allows a simple parametrization and comparison of different heavy-fermion ultraviolet completions. In addition, one particular fermionic completion is explored in detail, obtaining the corresponding leading low-energy fermionic operators. (orig.)

  20. Linearization: Geometric, Complex, and Conditional

    Directory of Open Access Journals (Sweden)

    Asghar Qadir

    2012-01-01

    Full Text Available Lie symmetry analysis provides a systematic method of obtaining exact solutions of nonlinear (systems of differential equations, whether partial or ordinary. Of special interest is the procedure that Lie developed to transform scalar nonlinear second-order ordinary differential equations to linear form. Not much work was done in this direction to start with, but recently there have been various developments. Here, first the original work of Lie (and the early developments on it, and then more recent developments based on geometry and complex analysis, apart from Lie’s own method of algebra (namely, Lie group theory, are reviewed. It is relevant to mention that much of the work is not linearization but uses the base of linearization.

  1. Window observers for linear systems

    Directory of Open Access Journals (Sweden)

    Utkin Vadim

    2000-01-01

    Full Text Available Given a linear system x ˙ = A x + B u with output y = C x and a window function ω ( t , i.e., ∀ t , ω ( t ∈ {0,1 }, and assuming that the window function is Lebesgue measurable, we refer to the following observer, x ˆ = A x + B u + ω ( t L C ( x − x ˆ as a window observer. The stability issue is treated in this paper. It is proven that for linear time-invariant systems, the window observer can be stabilized by an appropriate design under a very mild condition on the window functions, albeit for linear time-varying system, some regularity of the window functions is required to achieve observer designs with the asymptotic stability. The corresponding design methods are developed. An example is included to illustrate the possible applications

  2. Topics in quaternion linear algebra

    CERN Document Server

    Rodman, Leiba

    2014-01-01

    Quaternions are a number system that has become increasingly useful for representing the rotations of objects in three-dimensional space and has important applications in theoretical and applied mathematics, physics, computer science, and engineering. This is the first book to provide a systematic, accessible, and self-contained exposition of quaternion linear algebra. It features previously unpublished research results with complete proofs and many open problems at various levels, as well as more than 200 exercises to facilitate use by students and instructors. Applications presented in the book include numerical ranges, invariant semidefinite subspaces, differential equations with symmetries, and matrix equations. Designed for researchers and students across a variety of disciplines, the book can be read by anyone with a background in linear algebra, rudimentary complex analysis, and some multivariable calculus. Instructors will find it useful as a complementary text for undergraduate linear algebra courses...

  3. Towards the International Linear Collider

    International Nuclear Information System (INIS)

    Lopez-Fernandez, Ricardo

    2006-01-01

    The broad physics potential of e+e- linear colliders was recognized by the high energy physics community right after the end of LEP in 2000. In 2007, the Large Hadron Collider (LHC) now under construction at CERN will obtain its first collisions. The LHC, colliding protons with protons at 14 TeV, will discover a standard model Higgs boson over the full potential mass range, and should be sensitive to new physics into the several TeV range. The program for the Linear Collider (LC) will be set in the context of the discoveries made at the LHC. All the proposals for a Linear Collider will extend the discoveries and provide a wealth of measurements that are essential for giving deeper understanding of their meaning, and pointing the way to further evolution of particle physics in the future. For the mexican groups is the right time to join such an effort

  4. Linear Synchronous Motor Repeatability Tests

    International Nuclear Information System (INIS)

    Ward, C.R.

    2002-01-01

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility

  5. Linearly polarized photons at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, Holger [Physikalisches Institut, Universitaet Bonn (Germany)

    2009-07-01

    To investigate the nucleon resonance regime in meson photoproduction, double polarization experiments are currently performed at the electron accelerator ELSA in Bonn. The experiments make use of a polarized target and circularly or linearly polarized photon beams. Linearly polarized photons are produced by coherent bremsstrahlung from an accurately aligned diamond crystal. The orientation of the crystal with respect to the electron beam is measured using the Stonehenge-Technique. Both, the energy of maximum polarization and the plane of polarization, can be deliberately chosen for the experiment. The linearly polarized beam provides the basis for the measurement of azimuthal beam asymmetries, such as {sigma} (unpolarized target) and G (polarized target). These observables are extracted in various single and multiple meson photoproduction channels.

  6. Linear programming foundations and extensions

    CERN Document Server

    Vanderbei, Robert J

    2001-01-01

    Linear Programming: Foundations and Extensions is an introduction to the field of optimization. The book emphasizes constrained optimization, beginning with a substantial treatment of linear programming, and proceeding to convex analysis, network flows, integer programming, quadratic programming, and convex optimization. The book is carefully written. Specific examples and concrete algorithms precede more abstract topics. Topics are clearly developed with a large number of numerical examples worked out in detail. Moreover, Linear Programming: Foundations and Extensions underscores the purpose of optimization: to solve practical problems on a computer. Accordingly, the book is coordinated with free efficient C programs that implement the major algorithms studied: -The two-phase simplex method; -The primal-dual simplex method; -The path-following interior-point method; -The homogeneous self-dual methods. In addition, there are online JAVA applets that illustrate various pivot rules and variants of the simplex m...

  7. Uniqueness theorems in linear elasticity

    CERN Document Server

    Knops, Robin John

    1971-01-01

    The classical result for uniqueness in elasticity theory is due to Kirchhoff. It states that the standard mixed boundary value problem for a homogeneous isotropic linear elastic material in equilibrium and occupying a bounded three-dimensional region of space possesses at most one solution in the classical sense, provided the Lame and shear moduli, A and J1 respectively, obey the inequalities (3 A + 2 J1) > 0 and J1>O. In linear elastodynamics the analogous result, due to Neumann, is that the initial-mixed boundary value problem possesses at most one solution provided the elastic moduli satisfy the same set of inequalities as in Kirchhoffs theorem. Most standard textbooks on the linear theory of elasticity mention only these two classical criteria for uniqueness and neglect altogether the abundant literature which has appeared since the original publications of Kirchhoff. To remedy this deficiency it seems appropriate to attempt a coherent description ofthe various contributions made to the study of uniquenes...

  8. Bayes linear statistics, theory & methods

    CERN Document Server

    Goldstein, Michael

    2007-01-01

    Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...

  9. Scalar-tensor linear inflation

    Energy Technology Data Exchange (ETDEWEB)

    Artymowski, Michał [Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland); Racioppi, Antonio, E-mail: Michal.Artymowski@uj.edu.pl, E-mail: Antonio.Racioppi@kbfi.ee [National Institute of Chemical Physics and Biophysics, Rävala 10, 10143 Tallinn (Estonia)

    2017-04-01

    We investigate two approaches to non-minimally coupled gravity theories which present linear inflation as attractor solution: a) the scalar-tensor theory approach, where we look for a scalar-tensor theory that would restore results of linear inflation in the strong coupling limit for a non-minimal coupling to gravity of the form of f (φ) R /2; b) the particle physics approach, where we motivate the form of the Jordan frame potential by loop corrections to the inflaton field. In both cases the Jordan frame potentials are modifications of the induced gravity inflationary scenario, but instead of the Starobinsky attractor they lead to linear inflation in the strong coupling limit.

  10. Cardiac Vagal Control and Depressive Symptoms in Response to Negative Emotional Stress.

    Science.gov (United States)

    Tonhajzerova, I; Visnovcova, Z; Mestanikova, A; Jurko, A; Mestanik, M

    We aimed to study complex cardiovagal control using heart rate variability (HRV), linear and nonlinear analyses at rest and during negative emotional stress in healthy students with varying depressive symptoms. ECG recording in 20 students was performed at baseline, negative emotional stress, and recovery period. The HRV parameters evaluated were the following: RR interval, spectral power in high-frequency band (HF-HRV), and symbolic dynamics index 2LV%. The subjects were divided into two groups based on the score of the Beck Depression Inventory (BDI) - normal mood (BDI: 0.6 ± 0.2) and mild mood disturbance (BDI: 14.3 ± 1.4). We found significantly lower logHF-HRV during emotional stress in mild mood disturbance compared with normal mood (p = 0.047). No significant differences were found in the remaining parameters. We conclude that negative emotional stress attenuated the cardiovagal control during mood disturbance, which points to discrete abnormalities in the neurocardiac reflex system associated with depressive symptoms. Hampered cardiovagal control could represent a potential pathomechanism leading to depression-linked cardiovascular complications.

  11. Permafrost Hazards and Linear Infrastructure

    Science.gov (United States)

    Stanilovskaya, Julia; Sergeev, Dmitry

    2014-05-01

    The international experience of linear infrastructure planning, construction and exploitation in permafrost zone is being directly tied to the permafrost hazard assessment. That procedure should also consider the factors of climate impact and infrastructure protection. The current global climate change hotspots are currently polar and mountain areas. Temperature rise, precipitation and land ice conditions change, early springs occur more often. The big linear infrastructure objects cross the territories with different permafrost conditions which are sensitive to the changes in air temperature, hydrology, and snow accumulation which are connected to climatic dynamics. One of the most extensive linear structures built on permafrost worldwide are Trans Alaskan Pipeline (USA), Alaska Highway (Canada), Qinghai-Xizang Railway (China) and Eastern Siberia - Pacific Ocean Oil Pipeline (Russia). Those are currently being influenced by the regional climate change and permafrost impact which may act differently from place to place. Thermokarst is deemed to be the most dangerous process for linear engineering structures. Its formation and development depend on the linear structure type: road or pipeline, elevated or buried one. Zonal climate and geocryological conditions are also of the determining importance here. All the projects are of the different age and some of them were implemented under different climatic conditions. The effects of permafrost thawing have been recorded every year since then. The exploration and transportation companies from different countries maintain the linear infrastructure from permafrost degradation in different ways. The highways in Alaska are in a good condition due to governmental expenses on annual reconstructions. The Chara-China Railroad in Russia is under non-standard condition due to intensive permafrost response. Standards for engineering and construction should be reviewed and updated to account for permafrost hazards caused by the

  12. A Linear Electromagnetic Piston Pump

    Science.gov (United States)

    Hogan, Paul H.

    Advancements in mobile hydraulics for human-scale applications have increased demand for a compact hydraulic power supply. Conventional designs couple a rotating electric motor to a hydraulic pump, which increases the package volume and requires several energy conversions. This thesis investigates the use of a free piston as the moving element in a linear motor to eliminate multiple energy conversions and decrease the overall package volume. A coupled model used a quasi-static magnetic equivalent circuit to calculate the motor inductance and the electromagnetic force acting on the piston. The force was an input to a time domain model to evaluate the mechanical and pressure dynamics. The magnetic circuit model was validated with finite element analysis and an experimental prototype linear motor. The coupled model was optimized using a multi-objective genetic algorithm to explore the parameter space and maximize power density and efficiency. An experimental prototype linear pump coupled pistons to an off-the-shelf linear motor to validate the mechanical and pressure dynamics models. The magnetic circuit force calculation agreed within 3% of finite element analysis, and within 8% of experimental data from the unoptimized prototype linear motor. The optimized motor geometry also had good agreement with FEA; at zero piston displacement, the magnetic circuit calculates optimized motor force within 10% of FEA in less than 1/1000 the computational time. This makes it well suited to genetic optimization algorithms. The mechanical model agrees very well with the experimental piston pump position data when tuned for additional unmodeled mechanical friction. Optimized results suggest that an improvement of 400% of the state of the art power density is attainable with as high as 85% net efficiency. This demonstrates that a linear electromagnetic piston pump has potential to serve as a more compact and efficient supply of fluid power for the human scale.

  13. Sparse Linear Identifiable Multivariate Modeling

    DEFF Research Database (Denmark)

    Henao, Ricardo; Winther, Ole

    2011-01-01

    and bench-marked on artificial and real biological data sets. SLIM is closest in spirit to LiNGAM (Shimizu et al., 2006), but differs substantially in inference, Bayesian network structure learning and model comparison. Experimentally, SLIM performs equally well or better than LiNGAM with comparable......In this paper we consider sparse and identifiable linear latent variable (factor) and linear Bayesian network models for parsimonious analysis of multivariate data. We propose a computationally efficient method for joint parameter and model inference, and model comparison. It consists of a fully...

  14. Quantized, piecewise linear filter network

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    1993-01-01

    A quantization based piecewise linear filter network is defined. A method for the training of this network based on local approximation in the input space is devised. The training is carried out by repeatedly alternating between vector quantization of the training set into quantization classes...... and equalization of the quantization classes linear filter mean square training errors. The equalization of the mean square training errors is carried out by adapting the boundaries between neighbor quantization classes such that the differences in mean square training errors are reduced...

  15. Correct Linearization of Einstein's Equations

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2006-06-01

    Full Text Available Regularly Einstein's equations can be reduced to a wave form (linearly dependent from the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel's symbols. As shown here, the origin of the problem is that one uses the general covariant theory of measurement. Here the wave form of Einstein's equations is obtained in the terms of Zelmanov's chronometric invariants (physically observable projections on the observer's time line and spatial section. The obtained equations depend on solely the second derivatives even if gravitation, the space rotation and Christoffel's symbols. The correct linearization proves: the Einstein equations are completely compatible with weak waves of the metric.

  16. Basic linear partial differential equations

    CERN Document Server

    Treves, Francois

    1975-01-01

    Focusing on the archetypes of linear partial differential equations, this text for upper-level undergraduates and graduate students features most of the basic classical results. The methods, however, are decidedly nontraditional: in practically every instance, they tend toward a high level of abstraction. This approach recalls classical material to contemporary analysts in a language they can understand, as well as exploiting the field's wealth of examples as an introduction to modern theories.The four-part treatment covers the basic examples of linear partial differential equations and their

  17. Introduction to computational linear algebra

    CERN Document Server

    Nassif, Nabil; Erhel, Jocelyne

    2015-01-01

    Introduction to Computational Linear Algebra introduces the reader with a background in basic mathematics and computer programming to the fundamentals of dense and sparse matrix computations with illustrating examples. The textbook is a synthesis of conceptual and practical topics in ""Matrix Computations."" The book's learning outcomes are twofold: to understand state-of-the-art computational tools to solve matrix computations problems (BLAS primitives, MATLAB® programming) as well as essential mathematical concepts needed to master the topics of numerical linear algebra. It is suitable for s

  18. Linear feedback controls the essentials

    CERN Document Server

    Haidekker, Mark A

    2013-01-01

    The design of control systems is at the very core of engineering. Feedback controls are ubiquitous, ranging from simple room thermostats to airplane engine control. Helping to make sense of this wide-ranging field, this book provides a new approach by keeping a tight focus on the essentials with a limited, yet consistent set of examples. Analysis and design methods are explained in terms of theory and practice. The book covers classical, linear feedback controls, and linear approximations are used when needed. In parallel, the book covers time-discrete (digital) control systems and juxtapos

  19. Passive longitudinal phase space linearizer

    Directory of Open Access Journals (Sweden)

    P. Craievich

    2010-03-01

    Full Text Available We report on the possibility to passively linearize the bunch compression process in electron linacs for the next generation x-ray free electron lasers. This can be done by using the monopole wakefields in a dielectric-lined waveguide. The optimum longitudinal voltage loss over the length of the bunch is calculated in order to compensate both the second-order rf time curvature and the second-order momentum compaction terms. Thus, the longitudinal phase space after the compression process is linearized up to a fourth-order term introduced by the convolution between the bunch and the monopole wake function.

  20. Generalized, Linear, and Mixed Models

    CERN Document Server

    McCulloch, Charles E; Neuhaus, John M

    2011-01-01

    An accessible and self-contained introduction to statistical models-now in a modernized new editionGeneralized, Linear, and Mixed Models, Second Edition provides an up-to-date treatment of the essential techniques for developing and applying a wide variety of statistical models. The book presents thorough and unified coverage of the theory behind generalized, linear, and mixed models and highlights their similarities and differences in various construction, application, and computational aspects.A clear introduction to the basic ideas of fixed effects models, random effects models, and mixed m

  1. Emittance control in linear colliders

    International Nuclear Information System (INIS)

    Ruth, R.D.

    1991-01-01

    Before completing a realistic design of a next-generation linear collider, the authors must first learn the lessons taught by the first generation, the SLC. Given that, they must make designs fault tolerant by including correction and compensation in the basic design. They must also try to eliminate these faults by improved alignment and stability of components. When these two efforts cross, they have a realistic design. The techniques of generation and control of emittance reviewed here provide a foundation for a design which can obtain the necessary luminosity in a next-generation linear collider

  2. Linear contextual modal type theory

    DEFF Research Database (Denmark)

    Schack-Nielsen, Anders; Schürmann, Carsten

    Abstract. When one implements a logical framework based on linear type theory, for example the Celf system [?], one is immediately con- fronted with questions about their equational theory and how to deal with logic variables. In this paper, we propose linear contextual modal type theory that gives...... a mathematical account of the nature of logic variables. Our type theory is conservative over intuitionistic contextual modal type theory proposed by Nanevski, Pfenning, and Pientka. Our main contributions include a mechanically checked proof of soundness and a working implementation....

  3. Geology of photo linear elements, Great Divide Basin, Wyoming

    Science.gov (United States)

    Blackstone, D. L., Jr.

    1973-01-01

    The author has identified the following significant results. Ground examination of photo linear elements in the Great Divide Basin, Wyoming indicates little if any tectonic control. Aeolian aspects are more widespread and pervasive than previously considered.

  4. Large-scale linear programs in planning and prediction.

    Science.gov (United States)

    2017-06-01

    Large-scale linear programs are at the core of many traffic-related optimization problems in both planning and prediction. Moreover, many of these involve significant uncertainty, and hence are modeled using either chance constraints, or robust optim...

  5. Unstable volatility functions: the break preserving local linear estimator

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irene

    The objective of this paper is to introduce the break preserving local linear (BPLL) estimator for the estimation of unstable volatility functions. Breaks in the structure of the conditional mean and/or the volatility functions are common in Finance. Markov switching models (Hamilton, 1989......) and threshold models (Lin and Terasvirta, 1994) are amongst the most popular models to describe the behaviour of data with structural breaks. The local linear (LL) estimator is not consistent at points where the volatility function has a break and it may even report negative values for finite samples...

  6. Linearized holographic isotropization at finite coupling

    Energy Technology Data Exchange (ETDEWEB)

    Atashi, Mahdi; Fadafan, Kazem Bitaghsir [Shahrood University of Technology, Physics Department (Iran, Islamic Republic of); Jafari, Ghadir [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of)

    2017-06-15

    We study holographic isotropization of an anisotropic homogeneous non-Abelian strongly coupled plasma in the presence of Gauss-Bonnet corrections. It was verified before that one can linearize Einstein's equations around the final black hole background and simplify the complicated setup. Using this approach, we study the expectation value of the boundary stress tensor. Although we consider small values of the Gauss-Bonnet coupling constant, it is found that finite coupling leads to significant increasing of the thermalization time. By including higher order corrections in linearization, we extend the results to study the effect of the Gauss-Bonnet coupling on the entropy production on the event horizon. (orig.)

  7. Negative Attitudes, Networks and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    This paper theoretically and empirically assesses the potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking. The paper considers that two these parameters may influence high and uneducated...... workers as well as immigrants and natives differently, creating different incentives to acquire education for the two groups. Using rich Danish administrative data, this paper finds suggestive evidence rejecting the theoretical case where negative attitudes decrease 1st generation immigrant education...... and indications that quality of networks seems to matter more for immigrants than the quantity of individuals in a potential network....

  8. Patch Test Negative Generalized Dermatitis.

    Science.gov (United States)

    Spiker, Alison; Mowad, Christen

    2016-01-01

    Allergic contact dermatitis is a common condition in dermatology. Patch testing is the criterion standard for diagnosis. However, dermatitis is not always caused by an allergen, and patch testing does not identify a culprit in every patient. Generalized dermatitis, defined as eczematous dermatitis affecting greater than 3 body sites, is often encountered in dermatology practice, especially patch test referral centers. Management for patients with generalized dermatitis who are patch test negative is challenging. The purpose of this article is to outline an approach to this challenging scenario and summarize the paucity of existing literature on patch test negative generalized dermatitis.

  9. New approach to solve fully fuzzy system of linear equations using ...

    Indian Academy of Sciences (India)

    This paper proposes two new methods to solve fully fuzzy system of linear equations. The fuzzy system has been converted to a crisp system of linear equations by using single and double parametric form of fuzzy numbers to obtain the non-negative solution. Double parametric form of fuzzy numbers is defined and applied ...

  10. Vanilla Technicolor at Linear Colliders

    DEFF Research Database (Denmark)

    T. Frandsen, Mads; Jarvinen, Matti; Sannino, Francesco

    2011-01-01

    We analyze the reach of Linear Colliders (LC)s for models of dynamical electroweak symmetry breaking. We show that LCs can efficiently test the compositeness scale, identified with the mass of the new spin-one resonances, till the maximum energy in the center-of-mass of the colliding leptons. In ...

  11. Variational linear algebraic equations method

    International Nuclear Information System (INIS)

    Moiseiwitsch, B.L.

    1982-01-01

    A modification of the linear algebraic equations method is described which ensures a variational bound on the phaseshifts for potentials having a definite sign at all points. The method is illustrated by the elastic scattering of s-wave electrons by the static field of atomic hydrogen. (author)

  12. Aspects of robust linear regression

    NARCIS (Netherlands)

    Davies, P.L.

    1993-01-01

    Section 1 of the paper contains a general discussion of robustness. In Section 2 the influence function of the Hampel-Rousseeuw least median of squares estimator is derived. Linearly invariant weak metrics are constructed in Section 3. It is shown in Section 4 that $S$-estimators satisfy an exact

  13. Periodic linear differential stochastic processes

    NARCIS (Netherlands)

    Kwakernaak, H.

    1975-01-01

    Periodic linear differential processes are defined and their properties are analyzed. Equivalent representations are discussed, and the solutions of related optimal estimation problems are given. An extension is presented of Kailath and Geesey’s [1] results concerning the innovations representation

  14. Linear colliders for photon collisions

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The enthusiasm of the first international workshop on photonphoton colliders and associated physics, held at the Lawrence Berkeley Laboratory from 28 March - 1 April, could have set a ball rolling. According to proponents of this physics, the particle physics one can study with a high energy linear collider is special and complements that of a hadron supercollider

  15. Saturation and linear transport equation

    International Nuclear Information System (INIS)

    Kutak, K.

    2009-03-01

    We show that the GBW saturation model provides an exact solution to the one dimensional linear transport equation. We also show that it is motivated by the BK equation considered in the saturated regime when the diffusion and the splitting term in the diffusive approximation are balanced by the nonlinear term. (orig.)

  16. Linear Methods for Image Interpolation

    Directory of Open Access Journals (Sweden)

    Pascal Getreuer

    2011-09-01

    Full Text Available We discuss linear methods for interpolation, including nearest neighbor, bilinear, bicubic, splines, and sinc interpolation. We focus on separable interpolation, so most of what is said applies to one-dimensional interpolation as well as N-dimensional separable interpolation.

  17. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  18. Data Compression with Linear Algebra

    OpenAIRE

    Etler, David

    2015-01-01

    A presentation on the applications of linear algebra to image compression. Covers entropy, the discrete cosine transform, thresholding, quantization, and examples of images compressed with DCT. Given in Spring 2015 at Ocean County College as part of the honors program.

  19. 175 Years of Linear Programming

    Indian Academy of Sciences (India)

    polynomial-time solvability of linear programming, that is, testing if a polyhedron Q E ~ ... Q is rational, i.e. all extreme points and rays of Q are ra- tional vectors or ..... rithrll terminates with an interior solution, a post-processing step is usually ...

  20. 175 Years of Linear Programming

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 10. 175 Years of Linear Programming - Max Flow = Min Cut. Vijay Chandru M R Rao. Series Article Volume 4 Issue 10 October 1999 pp 22-39. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Linear collider systems and costs

    International Nuclear Information System (INIS)

    Loew, G.A.

    1993-05-01

    The purpose of this paper is to examine some of the systems and sub-systems involved in so-called ''conventional'' e + e - linear colliders and to study how their design affects the overall cost of these machines. There are presently a total of at least six 500 GeV c. of m. linear collider projects under study in the world. Aside from TESLA (superconducting linac at 1.3 GHz) and CLIC (two-beam accelerator with main linac at 30GHz), the other four proposed e + e - linear colliders can be considered ''conventional'' in that their main linacs use the proven technique of driving room temperature accelerator sections with pulsed klystrons and modulators. The centrally distinguishing feature between these projects is their main linac rf frequency: 3 GHz for the DESY machine, 11.424 GHz for the SLAC and JLC machines, and 14 GHz for the VLEPP machine. The other systems, namely the electron and positron sources, preaccelerators, compressors, damping rings and final foci, are fairly similar from project to project. Probably more than 80% of the cost of these linear colliders will be incurred in the two main linacs facing each other and it is therefore in their design and construction that major savings or extra costs may be found

  2. Linear accelerators of the future

    International Nuclear Information System (INIS)

    Loew, G.A.

    1986-07-01

    Some of the requirements imposed on future linear accelerators to be used in electron-positron colliders are reviewed, as well as some approaches presently being examined for meeting those requirements. RF sources for use in these linacs are described, as well as wakefields, single bunches, and multiple-bunch trains

  3. 175 Years of Linear Programming

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 5. 175 Years of Linear Programming - Pune's Gift. Vijay Chandru M R Rao. Series Article Volume 4 Issue 5 May ... Computer Science and Automation, IISc Bangalore 560012, India. Director, Indian Institute of Management, Bannerghatta Road, ...

  4. Non-linear frequency and amplitude modulation of a nano-contact spin torque oscillator

    OpenAIRE

    Muduli, P. K.; Pogoryelov, Ye.; Bonetti, S.; Consolo, G.; Mancoff, Fred; Åkerman, Johan

    2009-01-01

    We study the current controlled modulation of a nano-contact spin torque oscillator. Three principally different cases of frequency non-linearity ($d^{2}f/dI^{2}_{dc}$ being zero, positive, and negative) are investigated. Standard non-linear frequency modulation theory is able to accurately describe the frequency shifts during modulation. However, the power of the modulated sidebands only agrees with calculations based on a recent theory of combined non-linear frequency and amplitude modulation.

  5. Production of negative helium ions

    International Nuclear Information System (INIS)

    Toledo, A.S. de; Sala, O.

    1977-01-01

    A negative helium ion source using potassium charge exchange vapor has been developed to be used as an injector for the Pelletron accelerator. 3 He and α beam currents of up to 2μA have been extracted with 75% particle transmission through the machine [pt

  6. Spaces of Piecewise Linear Manifolds

    DEFF Research Database (Denmark)

    Gomez Lopez, Mauricio Esteban

    Abstract In this thesis we introduce Δ-set  ψPLd(RN) which we regard as the piecewise linear analogue of the space ψd(RN) of smooth d-dimensional submanifoldsin RN introduced by Galatius in [4]. Using ψPLd(RN) we define a bi-Δ-set Cd(RN)•,• ( whose geometric realization BCPLd(RN) = llCd(RN)•,•ll ......Abstract In this thesis we introduce Δ-set  ψPLd(RN) which we regard as the piecewise linear analogue of the space ψd(RN) of smooth d-dimensional submanifoldsin RN introduced by Galatius in [4]. Using ψPLd(RN) we define a bi-Δ-set Cd(RN)•,• ( whose geometric realization BCPLd(RN) = ll...... BCPLd (RN) ≅ ΩN–1lψPLd (RN)•l when N — d  ≥ 3. The proof of the main theorem relies on properties of ψPLd (RN) • which arise from the fact that this Δ-set can be obtained from a more general contravariant functor PL op → Sets defined on the category of finite dimensional polyhedraand piecewise linear...... maps, and on a fiberwise transversality result for piecewise linear submersions whose fibers are contained in R × (-1,1)N-1 ⊆ RN . For the proof of this transversality result we use a theorem of Hudson on extensions of piecewise linear isotopies which is why we need to include the condition N — d ≥ 3...

  7. Negative Life Events and Antenatal Depression among Pregnant Women in Rural China: The Role of Negative Automatic Thoughts.

    Science.gov (United States)

    Wang, Yang; Wang, Xiaohua; Liu, Fangnan; Jiang, Xiaoning; Xiao, Yun; Dong, Xuehan; Kong, Xianglei; Yang, Xuemei; Tian, Donghua; Qu, Zhiyong

    2016-01-01

    Few studies have looked at the relationship between psychological and the mental health status of pregnant women in rural China. The current study aims to explore the potential mediating effect of negative automatic thoughts between negative life events and antenatal depression. Data were collected in June 2012 and October 2012. 495 rural pregnant women were interviewed. Depressive symptoms were measured by the Edinburgh postnatal depression scale, stresses of pregnancy were measured by the pregnancy pressure scale, negative automatic thoughts were measured by the automatic thoughts questionnaire, and negative life events were measured by the life events scale for pregnant women. We used logistic regression and path analysis to test the mediating effect. The prevalence of antenatal depression was 13.7%. In the logistic regression, the only socio-demographic and health behavior factor significantly related to antenatal depression was sleep quality. Negative life events were not associated with depression in the fully adjusted model. Path analysis showed that the eventual direct and general effects of negative automatic thoughts were 0.39 and 0.51, which were larger than the effects of negative life events. This study suggested that there was a potentially significant mediating effect of negative automatic thoughts. Pregnant women who had lower scores of negative automatic thoughts were more likely to suffer less from negative life events which might lead to antenatal depression.

  8. Schizophrenia and smoking: impact on negative symptoms

    Directory of Open Access Journals (Sweden)

    Miriam Saliba

    2017-06-01

    Full Text Available Introduction: it has been hypothesized that individuals with schizophrenia use nicotine to reduce negative symptoms and improve cognitive function. There is an inconsistency in the literature suggesting that nicotine could help decrease negative symptoms in schizophrenic patients. Objective: to investigate the effects of nicotine on the expression of the negative symptoms in smokers and non-smokers with schizophrenia. Methods: a cross sectional study, conducted between April and August 2016, 100 inpatients with schizophrenia (54 smokers and 46 non-smokers diagnosed according to DSM-V, at Psychiatric Hospital of the Cross Lebanon, were compared to changes in clinical parameters using CDSS, PANSS, and nicotine dependence using FTND. The Student’s t-test was used to compare between 2 groups, while the ANOVA test was used to compare between 3 or more groups. For categorical variables, the chi-2 test was used. Results: the mean age was 47.16 years (SD = 7.14 for smokers compared to 47.02 years (SD = 7.92 for non-smokers. 64.8% of smokers were males versus 45.7% of non-smokers. Smoking (high nicotine dependence significantly decreases the PANSS negative symptoms score between the 2 groups (p .05 for both variables. Discussion and conclusion: this study is the first to investigate the relationship between the expression of negative symptoms in individuals with schizophrenia and smoking in Lebanon. Cigarette smoking rates remain remarkably high in patients with schizophrenia. Smoking is a complex process which involves psychopathological, biochemical and neuropharmacological aspects among schizophrenic patients. Further studies are needed to acknowledge these findings and the reasons behind it.

  9. Linear fixed-field multipass arcs for recirculating linear accelerators

    Directory of Open Access Journals (Sweden)

    V. S. Morozov

    2012-06-01

    Full Text Available Recirculating linear accelerators (RLA’s provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dogbone RLA capable of transporting two beam passes with momenta different by a factor of 2. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dogbone RLA.

  10. Negative remodeling at the ostium of the left circumflex artery.

    Science.gov (United States)

    Kobayashi, Y; Mehran, R; Moussa, I; Reyes, A; Moses, J W

    2001-12-01

    We report an ostial lesion with negative remodeling. Coronary angiography revealed a 60% stenosis at the ostium of the left circumflex artery (LCX). Intravascular ultrasound (IVUS)-guided directional atherectomy followed by stenting was planned. However, IVUS images revealed no significant stenosis and negative remodeling at the ostium of the LCX. The lesion did not undergo intervention.

  11. Capillarity Induced Negative Pressure of Water Plugs in Nanochannels

    NARCIS (Netherlands)

    Tas, Niels Roelof; Mela, P.; Kramer, Tobias; Berenschot, Johan W.; van den Berg, Albert

    2003-01-01

    We have found evidence that water plugs in hydrophilic nanochannels can be at significant negative pressure due to tensile capillary forces. The negative pressure of water plugs in nanochannels induces bending of the thin channel capping layer, which results in a visible curvature of the liquid

  12. Negative thermal expansion in Sc2(WO4)3

    International Nuclear Information System (INIS)

    Evans, J.S.O.; Mary, T.A.; Sleight, A.W.

    1998-01-01

    Sc 2 (WO 4 ) 3 has been found to show the highly unusual property of negative thermal expansion over a temperature range of 10 to 1,073 K. Powder neutron diffraction data from 10 to 450 K shows an essentially linear decrease in cell volume as a function of temperature. The intrinsic linear coefficient of thermal expansion from this data is -2.2 x 10 -6 K -1 . The linear coefficient of thermal expansion measured on a ceramic bar of Sc 2 (WO 4 ) 3 can be as negative as -11 x 10 -6 K -1 due to microstructure changes as a function of temperature. Rietveld refinement as a function of temperature suggests that the intrinsic negative thermal expansion can be related to transverse vibrations of bridging oxygen atoms in the structure. The anharmonic nature of these vibrations leads to a coupled tilting of the quasi-rigid framework polyhedra. This tilting in turn causes the structure to become more dense with increasing temperature

  13. [Multiple linear regression and ROC curve analysis of the factors of lumbar spine bone mineral density].

    Science.gov (United States)

    Zhang, Xiaodong; Zhao, Yinxia; Hu, Shaoyong; Hao, Shuai; Yan, Jiewen; Zhang, Lingyan; Zhao, Jing; Li, Shaolin

    2015-09-01

    To investigate the correlation between the lumbar vertebra bone mineral density (BMD) and age, gender, height, weight, body mass index, waistline, hipline, bone marrow and abdomen fat, and to explore the key factor affecting the BMD. A total of 72 cases were randomly recruited. All the subjects underwent a spectroscopic examination of the third lumber vertebra with single-voxel method in 1.5T MR. Lipid fractions (FF%) were measured. Quantitative CT were also performed to get the BMD of L3 and the corresponding abdomen subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). The statistical analysis were performed by SPSS 19.0. Multiple linear regression showed except the age and FF% showed significant difference (P0.05). The correlation of age and FF% with BMD was statistically negatively significant (r=-0.830, -0.521, P<0.05). The ROC curve analysis showed that the sensitivety and specificity of predicting osteoporosis were 81.8% and 86.9%, with a threshold of 58.5 years old. And it showed that the sensitivety and specificity of predicting osteoporosis were 90.9% and 55.7%, with a threshold of 52.8% for FF%. The lumbar vertebra BMD was significantly and negatively correlated with age and bone marrow FF%, but it was not significantly correlated with gender, height, weight, BMI, waistline, hipline, SAT and VAT. And age was the critical factor.

  14. Metric preheating and limitations of linearized gravity

    International Nuclear Information System (INIS)

    Bassett, Bruce A.; Tamburini, Fabrizio; Kaiser, David I.; Maartens, Roy

    1999-01-01

    During the preheating era after inflation, resonant amplification of quantum field fluctuations takes place. Recently it has become clear that this must be accompanied by resonant amplification of scalar metric fluctuations, since the two are united by Einstein's equations. Furthermore, this 'metric preheating' enhances particle production, and leads to gravitational rescattering effects even at linear order. In multi-field models with strong preheating (q>>1), metric perturbations are driven non-linear, with the strongest amplification typically on super-Hubble scales (k→0). This amplification is causal, being due to the super-Hubble coherence of the inflaton condensate, and is accompanied by resonant growth of entropy perturbations. The amplification invalidates the use of the linearized Einstein field equations, irrespective of the amount of fine-tuning of the initial conditions. This has serious implications on all scales - from large-angle cosmic microwave background (CMB) anisotropies to primordial black holes. We investigate the (q,k) parameter space in a two-field model, and introduce the time to non-linearity, t nl , as the timescale for the breakdown of the linearized Einstein equations. t nl is a robust indicator of resonance behavior, showing the fine structure in q and k that one expects from a quasi-Floquet system, and we argue that t nl is a suitable generalization of the static Floquet index in an expanding universe. Backreaction effects are expected to shut down the linear resonances, but cannot remove the existing amplification, which threatens the viability of strong preheating when confronted with the CMB. Mode-mode coupling and turbulence tend to re-establish scale invariance, but this process is limited by causality and for small k the primordial scale invariance of the spectrum may be destroyed. We discuss ways to escape the above conclusions, including secondary phases of inflation and preheating solely to fermions. The exclusion principle

  15. Preface: Introductory Remarks: Linear Scaling Methods

    Science.gov (United States)

    Bowler, D. R.; Fattebert, J.-L.; Gillan, M. J.; Haynes, P. D.; Skylaris, C.-K.

    2008-07-01

    It has been just over twenty years since the publication of the seminal paper on molecular dynamics with ab initio methods by Car and Parrinello [1], and the contribution of density functional theory (DFT) and the related techniques to physics, chemistry, materials science, earth science and biochemistry has been huge. Nevertheless, significant improvements are still being made to the performance of these standard techniques; recent work suggests that speed improvements of one or even two orders of magnitude are possible [2]. One of the areas where major progress has long been expected is in O(N), or linear scaling, DFT, in which the computer effort is proportional to the number of atoms. Linear scaling DFT methods have been in development for over ten years [3] but we are now in an exciting period where more and more research groups are working on these methods. Naturally there is a strong and continuing effort to improve the efficiency of the methods and to make them more robust. But there is also a growing ambition to apply them to challenging real-life problems. This special issue contains papers submitted following the CECAM Workshop 'Linear-scaling ab initio calculations: applications and future directions', held in Lyon from 3-6 September 2007. A noteworthy feature of the workshop is that it included a significant number of presentations involving real applications of O(N) methods, as well as work to extend O(N) methods into areas of greater accuracy (correlated wavefunction methods, quantum Monte Carlo, TDDFT) and large scale computer architectures. As well as explicitly linear scaling methods, the conference included presentations on techniques designed to accelerate and improve the efficiency of standard (that is non-linear-scaling) methods; this highlights the important question of crossover—that is, at what size of system does it become more efficient to use a linear-scaling method? As well as fundamental algorithmic questions, this brings up

  16. Historical Significant Volcanic Eruption Locations

    Data.gov (United States)

    Department of Homeland Security — A significant eruption is classified as one that meets at least one of the following criteriacaused fatalities, caused moderate damage (approximately $1 million or...

  17. Control of Coherent Instabilities by Linear Coupling

    CERN Document Server

    Cappi, R; Möhl, D

    2001-01-01

    One of the main challenges in the design of high-energy colliders is the very high luminosity necessary to provide significant event rates. This imposes strong constraints to achieve and preserve beams of high brightness, i.e. intensity to emittance ratio, all along the injector chain. Amongst the phenomena that can blow up and even destroy the beam are transverse coherent instabilities. Two methods are widely used to damp these instabilities. The first one is Landau damping by non-linearities. The second consists in using an electronic feedback system. However, non-linearities are harmful to single-particle motion due to resonance phenomena, and powerful wideband feedback systems are expensive. It is shown in this paper that linear coupling is a further method that can be used to damp transverse coherent instabilities. The theory of collective motion is outlined, including the coupling of instability rise and damping rates, chromaticity and Landau damping. Experimental results obtained at the CERN PS are rep...

  18. A comment on framing effects in linear public good games

    OpenAIRE

    Cartwright, Edward

    2016-01-01

    A number of recent papers have looked at framing effects in linear public good games. In this comment, I argue that, within this literature, the distinction between give-take and positive–negative framing effects has become blurred, and that this is a barrier towards understanding the experimental evidence on framing effects. To make these points, I first illustrate that frames can differ along both an externality and choice dimension. I then argue that the existing evidence is consistent wit...

  19. Multivariate covariance generalized linear models

    DEFF Research Database (Denmark)

    Bonat, W. H.; Jørgensen, Bent

    2016-01-01

    are fitted by using an efficient Newton scoring algorithm based on quasi-likelihood and Pearson estimating functions, using only second-moment assumptions. This provides a unified approach to a wide variety of types of response variables and covariance structures, including multivariate extensions......We propose a general framework for non-normal multivariate data analysis called multivariate covariance generalized linear models, designed to handle multivariate response variables, along with a wide range of temporal and spatial correlation structures defined in terms of a covariance link...... function combined with a matrix linear predictor involving known matrices. The method is motivated by three data examples that are not easily handled by existing methods. The first example concerns multivariate count data, the second involves response variables of mixed types, combined with repeated...

  20. Systems of Inhomogeneous Linear Equations

    Science.gov (United States)

    Scherer, Philipp O. J.

    Many problems in physics and especially computational physics involve systems of linear equations which arise e.g. from linearization of a general nonlinear problem or from discretization of differential equations. If the dimension of the system is not too large standard methods like Gaussian elimination or QR decomposition are sufficient. Systems with a tridiagonal matrix are important for cubic spline interpolation and numerical second derivatives. They can be solved very efficiently with a specialized Gaussian elimination method. Practical applications often involve very large dimensions and require iterative methods. Convergence of Jacobi and Gauss-Seidel methods is slow and can be improved by relaxation or over-relaxation. An alternative for large systems is the method of conjugate gradients.