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Sample records for catt negative result

  1. Carrie Chapman Catt and Woman Suffrage.

    Science.gov (United States)

    Hardesty, Carolyn, Ed.

    1989-01-01

    Most of the material for this issue of the "Goldfinch," which explores the life of Carrie Chapman Catt, came from the archives of the State Historical Society of Iowa. Carrie Chapman Catt (1859-1947) was an Iowan who advocated woman suffrage and spent 26 years actively working for that cause. The issue contains a biography of Catt, and…

  2. An Apparent Paradox: Catt's Anomaly

    Science.gov (United States)

    Pieraccini, M.; Selleri, S.

    2013-01-01

    Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

  3. Phase I (CATTS Theory), Phase II (Milne Point), Phase III (Hydrate Ridge)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-10-31

    This study introduces a new type of cumulative seismic attribute (CATT) which quantifies gas hydrates resources in Hydrate Ridge offshore Oregon. CATT is base on case-specific transforms that portray hydrated reservoir properties. In this study we used a theoretical rock physics model to correct measured velocity log data.

  4. University of Arizona's Collaboration to Advance Teaching Technology and Science (CATTS): lesson for photonics education collaborations

    Science.gov (United States)

    Hall-Wallace, Michelle; Regens, Nancy L.; Pompea, Stephen M.

    2002-05-01

    CATTS is a National Science Foundation-funded partnership between the University of Arizona and local school districts to improve science, mathematics and technology teaching at all levels. The goals of the CATTS Program are to develop sustainable partnerships with Kindergarten through 12th grade level (K-12) educators that foster integration of science, mathematics, engineering and technology research in classroom learning experiences. The program also creates opportunities for graduate and undergraduate students to be active participants in K-12 education by providing training and fellowships. CATTS seeks to foster effective teaching and a greater understanding of learning at all levels. School districts and University of Arizona outreach programs propose fellowship activities that address identified educational needs; they work together with CATTS to create customized programs to meet those needs. CATTS Fellows, their faculty mentors and K - 12 partners participate in workshops to gain experience with inquiry-based teaching and understanding diverse learning styles. In the partnership, CATTS Fellows have an opportunity to share their research experiences with K - 12 educators and gain experience with inquiry teaching. On the other side of the partnership, professional educators share their knowledge of teaching with Fellows and gain deeper understanding of scientific inquiry. In the two years that this NSF funded program has been in operation, a variety of lessons have been learned that can apply to school, university, and industrial partnerships to foster education and training. In particular since each organization operates in its own subculture, particular attention must be paid to raising cultural awareness among the participants in ways that foster mutual respect and communication of shared goals. Proper coordination and sensible logistics are also critical for the success of a complex project such as this. Training of the partners and the project

  5. Therapeutic efficacy of bevacizumab for age-related macular degeneration: what are the implications of CATT for routine management?

    Science.gov (United States)

    Ziemssen, Focke; Sobolewska, Bianka

    2011-11-01

    CATT (Comparison of Age-related macular degeneration [AMD] Treatment Trials) examined the efficacy of ranibizumab and bevacizumab for the treatment of neovascular AMD. This prospective, randomized, but unblinded trial revealed a significant improvement in vision with both treatments in terms of visual acuity; importantly, patients with juxtafoveal choroidal neovascularization (CNV) and retinal pigment epithelial detachments were not excluded from the study. Monthly treatment with the drugs resulted in similar increases in visual acuity, although angiograms indicated that ranibizumab was superior in terms of reducing retinal fluid and leakage. As the study also differentiated between a fixed regimen and an as-needed (pro re nata [PRN]) dosing regimen, a larger sample size and Bonferroni statistical correction were necessary. The equivalence of the PRN dosing of bevacizumab to the monthly treatment could not be confirmed. Almost all of the frequent deviations from the protocol (referring to retreatment criteria: 25.7-28.5%) resulted in under-treatment. Since this applied to both drugs equally, under-treatment alone could not explain the larger loss of visual acuity observed in the bevacizumab PRN arm. The PRN regimen was generally associated with a larger lesion size after 12 months compared with the fixed treatment regimens. The investigators accepted the drawbacks of an incomplete masking to allow co-payment by Medicare. As assessments of drug trials are often politically motivated, the higher demands of a non-inferiority trial compared with a superiority design must be emphasized. A comparison of the per-protocol and last-observation-carried-forward analysis has not yet been published; ongoing subgroup analysis might highlight the impact of different lesion characteristics. While CATT provided further evidence for the efficacy of bevacizumab treatment, differences in adverse events between the two treatments (e.g. a higher rate of serious adverse events with

  6. Thank you to reviewers of negative results in 2014

    Directory of Open Access Journals (Sweden)

    David Alcantara

    2014-12-01

    Full Text Available The mission of The All Results Journals:Biol is the communication of excellent research work obtaining negative results from all fields of biology and biomedicine. Clearly, a scientific journal’s greatest responsibility toward the scientific community is to ensure that all contributions accepted for publication are rigorously but fairly reviewed, specially in a journal of negative results like this. For this reason, all manuscripts published in the journal are reviewed by expert referees. The final quality of papers accepted for publication depends to a considerable extent on the reviewers, who give valuable constructive criticism to the authors. The input and dedication of all our reviewers are highly appreciated by both the editors and the authors.

  7. Large Deviation Results for Generalized Compound Negative Binomial Risk Models

    Institute of Scientific and Technical Information of China (English)

    Fan-chao Kong; Chen Shen

    2009-01-01

    In this paper we extend and improve some results of the large deviation for random sums of random variables.Let {Xn;n≥1} be a sequence of non-negative,independent and identically distributed random variables with common heavy-tailed distribution function F and finite mean μ∈R+,{N(n);n≥0} be a sequence of negative binomial distributed random variables with a parameter p ∈(0,1),n≥0,let {M(n);n≥0} be a Poisson process with intensity λ0.Suppose {N(n);n≥0},{Xn;n≥1} and {M(n);n≥0} are mutually results.These results can be applied to certain problems in insurance and finance.

  8. False negative results from using common PCR reagents

    Directory of Open Access Journals (Sweden)

    Atwood Allison A

    2011-10-01

    Full Text Available Abstract Background The sensitivity of the PCR reaction makes it ideal for use when identifying potentially novel viral infections in human disease. Unfortunately, this same sensitivity also leaves this popular technique open to potential contamination with previously amplified PCR products, or "carry-over" contamination. PCR product carry-over contamination can be prevented with uracil-DNA-glycosylase (UNG, and it is for this reason that it is commonly included in many commercial PCR master-mixes. While testing the sensitivity of PCR assays to detect murine DNA contamination in human tissue samples, we inadvertently discovered that the use of this common PCR reagent may lead to the production of false-negative PCR results. Findings We show here that contamination with minute quantities of UNG-digested PCR product or any negative control PCR reactions containing primer-dimers regardless of UNG presence can completely block amplification from as much as 60 ng of legitimate target DNA. Conclusions These findings could potentially explain discrepant results from laboratories attempting to amplify MLV-related viruses including XMRV from human samples, as none of the published reports used internal-tube controls for amplification. The potential for false negative results needs to be considered and carefully controlled in PCR experiments, especially when the target copy number may be low - just as the potential for false positive results already is.

  9. Association between the −794 (CATT)5–8  MIF Gene Polymorphism and Susceptibility to Acute Coronary Syndrome in a Western Mexican Population

    Science.gov (United States)

    Valdés-Alvarado, Emmanuel; Muñoz-Valle, José Francisco; Valle, Yeminia; Sandoval-Pinto, Elena; García-González, Ilian Janet; Valdez-Haro, Angélica; Flores-Salinas, Héctor Enrique; Padilla-Gutiérrez, Jorgé Ramón

    2014-01-01

    The macrophage migration inhibitory factor (MIF) is related to the progression of atherosclerosis, which, in turn, is a key factor in the development of acute coronary syndrome (ACS). MIF has a CATT short tandem repeat (STR) at position −794 that might be involved in its expression rate. The aim of this study was to investigate the association between the −794 (CATT)5–8  MIF gene polymorphism and susceptibility to ACS in a western Mexican population. This research included 200 ACS patients classified according to the criteria of the American College of Cardiology (ACC) and 200 healthy subjects (HS). The −794 (CATT)5–8  MIF gene polymorphism was analyzed using a conventional polymerase chain reaction (PCR) technique. The 6 allele was the most frequent in both groups (ACS: 54% and HS: 57%). The most common genotypes in ACS patients and HS were 6/7 and 6/6, respectively, and a significant association was found between the 6/7 genotype and susceptibility to ACS (68% versus 47% in ACS and HS, resp., P = 0.03). We conclude that the 6/7 genotype of the MIF −794 (CATT)5–8 polymorphism is associated with susceptibility to ACS in a western Mexican population. PMID:25105152

  10. Association between the −794 (CATT5–8  MIF Gene Polymorphism and Susceptibility to Acute Coronary Syndrome in a Western Mexican Population

    Directory of Open Access Journals (Sweden)

    Emmanuel Valdés-Alvarado

    2014-01-01

    Full Text Available The macrophage migration inhibitory factor (MIF is related to the progression of atherosclerosis, which, in turn, is a key factor in the development of acute coronary syndrome (ACS. MIF has a CATT short tandem repeat (STR at position −794 that might be involved in its expression rate. The aim of this study was to investigate the association between the −794 CATT5–8  MIF gene polymorphism and susceptibility to ACS in a western Mexican population. This research included 200 ACS patients classified according to the criteria of the American College of Cardiology (ACC and 200 healthy subjects (HS. The −794 CATT5–8  MIF gene polymorphism was analyzed using a conventional polymerase chain reaction (PCR technique. The 6 allele was the most frequent in both groups (ACS: 54% and HS: 57%. The most common genotypes in ACS patients and HS were 6/7 and 6/6, respectively, and a significant association was found between the 6/7 genotype and susceptibility to ACS (68% versus 47% in ACS and HS, resp., P=0.03. We conclude that the 6/7 genotype of the MIF −794 CATT5–8 polymorphism is associated with susceptibility to ACS in a western Mexican population.

  11. Incidence of cervical cancer after several negative smear results by age 50: prospective observational study

    DEFF Research Database (Denmark)

    Rebolj, Matejka; van Ballegooijen, Marjolein; Lynge, Elsebeth;

    2009-01-01

    of histopathology and cytopathology (PALGA). SETTING: Netherlands, national data. Population 218,847 women aged 45-54 and 445,382 aged 30-44 at the time of the third negative smear test. MAIN OUTCOME MEASURES: 10 year cumulative incidence of interval cervical cancer. RESULTS: 105 women developed cervical cancer...... after several negative smear results by age 50 is similar to the risk at younger ages. Even after several negative smear results, age is not a good discriminative factor for early cessation of cervical cancer screening....

  12. Negative symptom improvement during cognitive rehabilitation: results from a 2-year trial of Cognitive Enhancement Therapy.

    Science.gov (United States)

    Eack, Shaun M; Mesholam-Gately, Raquelle I; Greenwald, Deborah P; Hogarty, Susan S; Keshavan, Matcheri S

    2013-08-30

    Cognitive rehabilitation has shown beneficial effects on cognition in patients with schizophrenia, which may also help to improve negative symptoms due to overlapping pathophysiology between these two domains. To better understand the possible relationship between these areas, we conducted an exploratory analysis of the effects of Cognitive Enhancement Therapy (CET) on negative symptoms. Early course schizophrenia outpatients (n=58) were randomized to 2 years of CET or an Enriched Supportive Therapy (EST) control condition. Results revealed significant and medium-sized (d=0.61) differential improvements favoring CET in overall negative symptoms, particularly social withdrawal, affective flattening, and motor retardation. Neurocognitive improvement was associated with reduced negative symptoms in CET, but not EST patients. No relationships were observed between improvements in emotion processing aspects of social cognition, as measured by the Mayer-Salovey-Caruso Emotional Intelligence Test, and negative symptoms. CET represents an effective cognitive rehabilitation intervention for schizophrenia that may also have benefits to negative symptoms. Future studies specifically designed to examine negative symptoms during the course of cognitive rehabilitation are needed.

  13. Reliability of environmental sampling culture results using the negative binomial intraclass correlation coefficient.

    Science.gov (United States)

    Aly, Sharif S; Zhao, Jianyang; Li, Ben; Jiang, Jiming

    2014-01-01

    The Intraclass Correlation Coefficient (ICC) is commonly used to estimate the similarity between quantitative measures obtained from different sources. Overdispersed data is traditionally transformed so that linear mixed model (LMM) based ICC can be estimated. A common transformation used is the natural logarithm. The reliability of environmental sampling of fecal slurry on freestall pens has been estimated for Mycobacterium avium subsp. paratuberculosis using the natural logarithm transformed culture results. Recently, the negative binomial ICC was defined based on a generalized linear mixed model for negative binomial distributed data. The current study reports on the negative binomial ICC estimate which includes fixed effects using culture results of environmental samples. Simulations using a wide variety of inputs and negative binomial distribution parameters (r; p) showed better performance of the new negative binomial ICC compared to the ICC based on LMM even when negative binomial data was logarithm, and square root transformed. A second comparison that targeted a wider range of ICC values showed that the mean of estimated ICC closely approximated the true ICC.

  14. False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13

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    Yang Cao

    2016-01-01

    Full Text Available Background. Noninvasive prenatal screening (NIPS is revolutionizing prenatal screening as a result of its increased sensitivity, specificity. NIPS analyzes cell-free fetal DNA (cffDNA circulating in maternal plasma to detect fetal chromosome abnormalities. However, cffDNA originates from apoptotic placental trophoblast; therefore cffDNA is not always representative of the fetus. Although the published data for NIPS testing states that the current technique ensures high sensitivity and specificity for aneuploidy detection, false positives are possible due to isolated placental mosaicism, vanishing twin or cotwin demise, and maternal chromosome abnormalities or malignancy. Results. We report a case of false negative cell-free DNA (cfDNA screening due to fetoplacental mosaicism. An infant male with negative cfDNA screening result was born with multiple congenital abnormalities. Postnatal chromosome and FISH studies on a blood specimen revealed trisomy 13 in 20/20 metaphases and 100% interphase nuclei, respectively. FISH analysis on tissues collected after delivery revealed extraembryonic mosaicism. Conclusions. Extraembryonic tissue mosaicism is likely responsible for the false negative cfDNA screening result. This case illustrates that a negative result does not rule out the possibility of a fetus affected with a trisomy, as cffDNA is derived from the placenta and therefore may not accurately represent the fetal genetic information.

  15. Negative results of growing titania nanotubes on cellulose nanocrystals - Effect of hydrothermal reaction

    Science.gov (United States)

    Chamakh, Mariem Mohamed; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

    Titania nanotubes (TiO2 nanotubes or TNT) are grown hydrothermally on cellulose nanocrystals (CNC) synthesized from microcrystalline cellulose. It is observed that the CNC are lost during synthesis due to its low thermal stability. This negative result of metal growth on CNC and its influence on thermal degradation are reported here.

  16. Unexplained False Negative Results in Noninvasive Prenatal Testing: Two Cases Involving Trisomies 13 and 18

    Directory of Open Access Journals (Sweden)

    R. Hochstenbach

    2015-01-01

    Full Text Available Noninvasive prenatal testing (NIPT validation studies show high sensitivity and specificity for detection of trisomies 13, 18, and 21. False negative cases have rarely been reported. We describe a false negative case of trisomy 13 and another of trisomy 18 in which NIPT was commercially marketed directly to the clinician. Both cases came to our attention because a fetal anatomy scan at 20 weeks of gestation revealed multiple anomalies. Karyotyping of cultured amniocytes showed nonmosaic trisomies 13 and 18, respectively. Cytogenetic investigation of cytotrophoblast cells from multiple placental biopsies showed a low proportion of nontrisomic cells in each case, but this was considered too small for explaining the false negative NIPT result. The discordant results also could not be explained by early gestational age, elevated maternal weight, a vanishing twin, or suboptimal storage or transport of samples. The root cause of the discrepancies could, therefore, not be identified. The couples involved experienced difficulties in accepting the unexpected and late-adverse outcome of their pregnancy. We recommend that all parties involved in caring for couples who choose NIPT should collaborate to clarify false negative results in order to unravel possible biological causes and to improve the process of patient care from initial counseling to communication of the result.

  17. A transfection reporter for the prevention of false-negative results in molecular beacon experiments.

    Science.gov (United States)

    Toga, Tatsuya; Kuraoka, Isao; Yasui, Akira; Iwai, Shigenori

    2013-09-01

    We previously developed a molecular beacon-type probe to detect the strand scission in cellular base excision repair and found that the phosphodiester linkages in the fluorophore/quencher linkers were cleaved. This reaction was applied to a transfection reporter, which contained the unmodified phosphodiester in the linker to another type of fluorophore. After cotransfection of cells with the probe and the reporter, the signals were used to detect the incision and to confirm the proper transfection, respectively. This method will contribute to the prevention of false-negative results in experiments using molecular beacon-type probes.

  18. Macrophage migration inhibitory factor (MIF) promoter polymorphisms (-794 CATT5-8 and -173 G>C): association with MIF and TNFα in psoriatic arthritis

    Science.gov (United States)

    Morales-Zambrano, Ramsés; Bautista-Herrera, Luis A; la Cruz-Mosso, Ulises De; Villanueva-Quintero, Guadalupe D; Padilla-Gutiérrez, Jorge R; Valle, Yeminia; Parra-Rojas, Isela; Rangel-Villalobos, Héctor; Gutiérrez-Ureña, Sergio R; Muñoz-Valle, José F

    2014-01-01

    Psoriatic arthritis (PsA) is an autoimmune disease with a complex interaction of gene and with a dysregulation of pro-inflammatory cytokine such as Macrophage migration Inhibitory Factor (MIF) and Tumor Necrosis Factor-alpha (TNFα). Two polymorphisms identified in the promoter region of the MIF gene have been described: the STR-794 CATT5-8 (rs5844572) and the SNP-173 G>C (rs755622), which are associated with increased MIF levels in circulation and with autoimmune diseases in several populations. In this case-control study we investigated whether commonly occurring functional MIF polymorphisms are associated with PsA susceptibility and clinical variables as well as with MIF and TNFα serum levels in a Mexican-Mestizo population. Genotyping of the -794 CATT5-8 and -173 G>C MIF polymorphisms was performed by PCR and PCR-RFLP respectively in 50 PsA patients and 100 healthy subjects (HS). MIF and TNFα serum levels were determined by ELISA. A significant increase of MIF (PsA: 7.8 vs. HS: 5.25 ng/mL; p C MIF were associated with susceptibility to PsA. In conclusion the -173*C allele is associated with susceptibility to PsA in Mexican-Mestizo population, whereas the correlation between MIF and TNFα soluble levels provided evidence that both cytokines are closely related in the pathophysiology of the PsA. PMID:25356116

  19. False positive and false negative radon measurement results due to uncertainties in seasonal correction factors

    Energy Technology Data Exchange (ETDEWEB)

    Cliff, K.D.; Miles, J.C.H.; Naismith, S.P. [National Radiological Protection Board, Chilton (United Kingdom)

    1994-12-31

    Data from the UK national survey of radon in 2300 homes has been re-analysed to determine the uncertainty in seasonal correction factors applied to measurements of less than 1 year. The required correction factor for each six-month result was calculated from the known annual average for the appropriate home. The seasonal correction factors derived for each month were found to be approximately log-normally distributed, with an average geometric standard deviation of 1.36. Following this initial survey, radon measurements have been made in more than 80,000 homes in southwest England to determine whether they are above the UK radon Action Level of 2000 Bq.m{sup -3}. The measurements were carried out over three months in each case using etched track detectors in two locations in each home, and the results were corrected for the average seasonal variation found in the original UK study of radon in homes. Because of the uncertainty in the seasonal correction factors, households with between 130 and 300 Bq.m{sup -3} were advised to have a second three-month measurement in a different season before deciding whether or not to take remedial action. More than 7000 homes were remonitored for this purpose. The results are analysed to show the number of false positive and false negative results that would have been reported if advice had been based solely on the initial measurement. It is shown that the present scheme results in extremely small numbers of false positive and false negative results. (author).

  20. First results of the ITER-relevant negative ion beam test facility ELISE (invited).

    Science.gov (United States)

    Fantz, U; Franzen, P; Heinemann, B; Wünderlich, D

    2014-02-01

    An important step in the European R&D roadmap towards the neutral beam heating systems of ITER is the new test facility ELISE (Extraction from a Large Ion Source Experiment) for large-scale extraction from a half-size ITER RF source. The test facility was constructed in the last years at Max-Planck-Institut für Plasmaphysik Garching and is now operational. ELISE is gaining early experience of the performance and operation of large RF-driven negative hydrogen ion sources with plasma illumination of a source area of 1 × 0.9 m(2) and an extraction area of 0.1 m(2) using 640 apertures. First results in volume operation, i.e., without caesium seeding, are presented.

  1. Milk composition and its relationship with weaning weight in Charolais catte

    Directory of Open Access Journals (Sweden)

    Víctor Inocencio Pacheco Contreras

    2015-06-01

    Full Text Available To determine the effects of a number of non-genetic factors on milk components and estimate their indirect relationships with weaning weight (WW205, the percentages of protein, fat, lactose and solids non-fat in Charolais cows from Mexico were estimated. Lactation period (LP and calving season (CS had significant effects on protein and fat, whereas lactose and solids non-fat were only affected by the LP. Sire line and age of the dam had significant effects on calf birth weight, while CS affected WW205. Residual correlations between milk components and WW205 suggest a low but significant correlation with lactose. These results demonstrate the importance of several non-genetic factors on the composition of milk from Charolais cows managed under extensive cow-calf production systems and the indirect relationships between these factors and the weaning weight of a calf.

  2. A Highly Sensitive Telomerase Activity Assay that Eliminates False-Negative Results Caused by PCR Inhibitors

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    Hidenobu Yaku

    2013-09-01

    Full Text Available An assay for telomerase activity based on asymmetric polymerase chain reaction (A-PCR on magnetic beads (MBs and subsequent application of cycling probe technology (CPT is described. In this assay, the telomerase reaction products are immobilized on MBs, which are then washed to remove PCR inhibitors that are commonly found in clinical samples. The guanine-rich sequences (5'-(TTAGGGn-3' of the telomerase reaction products are then preferentially amplified by A-PCR, and the amplified products are subsequently detected via CPT, where a probe RNA with a fluorophore at the 5' end and a quencher at the 3' end is hydrolyzed by RNase H in the presence of the target DNA. The catalyst-mediated cleavage of the probe RNA enhances fluorescence from the 5' end of the probe. The assay allowed us to successfully detect HeLa cells selectively over normal human dermal fibroblast (NHDF cells. Importantly, this selectivity produced identical results with regard to detection of HeLa cells in the absence and presence of excess NHDF cells; therefore, this assay can be used for practical clinical applications. The lower limit of detection for HeLa cells was 50 cells, which is lower than that achieved with a conventional telomeric repeat amplification protocol assay. Our assay also eliminated false-negative results caused by PCR inhibitors. Furthermore, we show that this assay is appropriate for screening among G-quadruplex ligands to find those that inhibit telomerase activity.

  3. Negative differential electrolyte resistance in a solid-state nanopore resulting from electroosmotic flow bistability.

    Science.gov (United States)

    Luo, Long; Holden, Deric A; White, Henry S

    2014-03-25

    A solid-state nanopore separating two aqueous solutions containing different concentrations of KCl is demonstrated to exhibit negative differential resistance (NDR) when a constant pressure is applied across the nanopore. NDR refers to a decrease in electrical current when the voltage applied across the nanopore is increased. NDR results from the interdependence of solution flow (electroosmotic and pressure-engendered) with the distributions of K+ and Cl- within the nanopore. A switch from a high-conductivity state to a low-conductivity state occurs over a very narrow voltage window (geometry, electrolyte concentration, and nanopore surface charge density. Finite element simulations based on a simultaneous solution of the Navier-Stokes, Poisson, and Nernst-Planck equations demonstrate that NDR results from a positive feedback mechanism between the ion distributions and electroosmotic flow, yielding a true bistability in fluid flow and electrical current at a critical applied voltage, i.e., the NDR "switching potential". Solution pH and Ca2+ were separately employed as chemical stimuli to investigate the dependence of the NDR on the surface charge density. The NDR switching potential is remarkably sensitive to the surface charge density, and thus to pH and the presence of Ca2+, suggesting possible applications in chemical sensing.

  4. Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

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    Morfin-Otero Rayo

    2012-06-01

    Full Text Available Abstract Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%, but exhibited lower rates for levofloxacin (18.2% vs 56%. Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%. This finding represents a disturbing development in a common nosocomial and community pathogen.

  5. JT-60 negative ion beam NBI apparatus. Present state of its construction and initial experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, Masaaki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1997-02-01

    The NBI (Neutral Beam Injection) apparatus used for negative ion at first in the world, has an aim to actually prove heating and electric current drive with high density plasma at the JT-60 and to constitute physical and technical bases for selection and design of heating apparatus of ITER (International Thermal Nuclear Fusion Experimental Reactor). Construction of 500 KeV negative ion NBI apparatus for the JT-60 started to operate on 1993 was completed at March, 1996. On the way, at a preliminary test on forming and acceleration of the negative ion beam using a portion of this apparatus, 400 KeV and 13.5 A/D of the highest deuterium negative ion beam acceleration in the world was obtained successfully, which gave a bright forecasting of the plasma heating and electric current drive experiment using the negative ion NBI apparatus. After March, 1996, some plans to begin beam incident experiment at the JT-60 using the negative ion NBI apparatus and to execute the heating and electric current drive experiment at the JT-60 under intending increase of beam output are progressed. (G.K.)

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

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    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.

  7. False Negative Fine Needle Aspiration Biopsy Results in Primary Thyroid Lymphoma

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    Kim, In Joong; Kim, Eun Kyung; Koh, Myoung Ju; Kwak, Jin Young; Moon, Hee Jung [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-06-15

    Ultrasonography-guided fine needle aspiration biopsy (US-FNA) is one of the methods used to diagnose thyroid lymphoma, but it has a relatively high false-negative rate. The authors report a case of a primary thyroid lymphoma associated with underlying lymphocytic thyroiditis that was initially misdiagnosed as lymphocytic thyroiditis based on US-FNA findings

  8. The Set-Point Theory of Well-Being: Negative Results and Consequent Revisions

    Science.gov (United States)

    Headey, Bruce

    2008-01-01

    An adequate theory of happiness or subjective well-being (SWB) needs to link at least three sets of variables: stable person characteristics (including personality traits), life events and measures of well-being (life satisfaction, positive affects) and ill-being (anxiety, depression, negative affects). It also needs to be based on long-term data…

  9. Understanding of a negative bowel screening result and potential impact on future symptom appraisal and help-seeking behaviour

    DEFF Research Database (Denmark)

    Barnett, Karen N; Weller, David; Smith, Steve;

    2016-01-01

    ) emotional response to a negative FOBt, (ii) understanding the limitations of FOBt screening, (iii) symptom knowledge and interpretation and (iv) over-reassurance from a negative FOBt. Participants were reassured by a negative FOBt, but there was variability in the extent to which the result was interpreted...... could lead to a short-term delay in help-seeking if symptoms developed. Screening programmes should seek to emphasize the importance of the temporal nature of FOBt results with key messages about symptom recognition and prompt help-seeking behaviour....

  10. Risk factors for false positive and for false negative test results in screening with fecal occult blood testing.

    Science.gov (United States)

    Stegeman, Inge; de Wijkerslooth, Thomas R; Stoop, Esther M; van Leerdam, Monique; van Ballegooijen, M; Kraaijenhagen, Roderik A; Fockens, Paul; Kuipers, Ernst J; Dekker, Evelien; Bossuyt, Patrick M

    2013-11-15

    Differences in the risk of a false negative or a false positive fecal immunochemical test (FIT) across subgroups may affect optimal screening strategies. We evaluate whether subgroups are at increased risk of a false positive or a false negative FIT result, whether such variability in risk is related to differences in FIT sensitivity and specificity or to differences in prior CRC risk. Randomly selected, asymptomatic individuals were invited to undergo colonoscopy. Participants were asked to undergo one sample FIT and to complete a risk questionnaire. We identified patient characteristics associated with a false negative and false positive FIT results using logistic regression. We focused on statistically significant differences as well as on variables influencing the false positive or negative risk for which the odds ratio exceeded 1.25. Of the 1,426 screening participants, 1,112 (78%) completed FIT and the questionnaire; 101 (9.1%) had advanced neoplasia. 102 Individuals were FIT positive, 65 (64%) had a false negative FIT result and 66 (65%) a false positive FIT result. Participants at higher age and smokers had a significantly higher risk of a false negative FIT result. Males were at increased risk of a false positive result, so were smokers and regular NSAID users. FIT sensitivity was lower in females. Specificity was lower for males, smokers and regular NSAID users. FIT sensitivity was lower in women. FIT specificity was lower in males, smokers and regular NSAID users. Our results can be used for further evidence based individualization of screening strategies.

  11. Comparison of length of stay and outcomes of patients with positive versus negative blood culture results.

    Science.gov (United States)

    Armstrong-Briley, Danielle; Hozhabri, Neda S T; Armstrong, Kris; Puthottile, Jason; Benavides, Raul; Beal, Stacy

    2015-01-01

    In the United States, sepsis is the leading cause of death in critically ill patients. The fatality rate for severe sepsis is about 40%, and treatment costs over $16 billion annually. It is critical to identify and treat the source of sepsis. While there are varying guidelines determining when to draw blood for culture, at Baylor University Medical Center at Dallas, blood cultures are ordered for patients with new onset of fever, immunosuppression, or a suspicion of an underlying infectious etiology. We conducted a retrospective study of patients who had blood cultures after hospital admission or in the emergency department in December 2013. We compared length of stay and outcomes of patients with positive versus negative blood cultures. There was no significant difference for length of stay or outcomes among patients with positive and negative blood cultures. For patients admitted from the emergency department, there was a longer length of stay for patients with positive cultures; however, the overall prognosis was not worse.

  12. Serum albumin and globulin analysis for hepatocellular carcinoma detection avoiding false-negative results from alpha-fetoprotein test negative subjects

    Science.gov (United States)

    Wang, Jing; Feng, Shangyuan; Lin, Juqiang; Zeng, Yongyi; Li, Ling; Huang, Zufang; Li, Buhong; Zeng, Haishan; Chen, Rong

    2013-11-01

    Surface-enhanced Raman spectroscopy (SERS) of serum albumin and globulin were employed to detect hepatocellular carcinoma (HCC). Tentative assignments of SERS bands show specific biomolecular changes associated with cancer development. These changes include a decrease in relative amounts of tryptophan, glutamine, glycine, and serine, indicating excessive consumption of amino acids for protein duplication. Principal component analysis was also introduced to analyze the obtained spectra, resulting in both diagnostic sensitivity and specificity of 100%. More importantly, it reveals that this method can detect HCC patients with alpha-fetoprotein negative test results, suggesting its great potential as a new alternative to detect HCC.

  13. FALSE-NEGATIVE DENGUE CASES IN RORAIMA, BRAZIL: AN APPROACH REGARDING THE HIGH NUMBER OF NEGATIVE RESULTS BY NS1 AG KITS

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    Pablo O. A. Acosta

    2014-09-01

    Full Text Available Serum samples from 150 NS1-negative (Platelia ELISA patients presumptively diagnosed with dengue were analyzed by the TaqMan probed real-time reverse transcription PCR (TaqMan qRT-PCR method. The qRT-PCR positive samples were tested for serotype by semi-nested RT-PCR and a qualitative immunochromatographic assay for IgG and IgM. Molecular detection methods showed 33 (22% positive samples out of 150 NS1-antigen negative samples. Of these, 72% were collected up to day 2 after the onset of symptoms, when diagnostic sensitivity of NS1-antigen test assays is significantly enhanced. Most of the cases were not characterized as secondary infection. Twenty-eight samples were successfully serotyped, 75% of which for DENV-4, 14% for DENV-2, 7% for DENV-3 and 4% for DENV-1. These findings reaffirm the hyperendemic situation of the state of Roraima and suggest a lower sensitivity of the NS1 test, mainly when DENV-4 is the predominant serotype. Health care providers should therefore be aware of samples tested negative by NS1 antigen assays, especially when clinical symptoms and other laboratory data results show evidence of dengue infection.

  14. Concepts and targets in triple-negative breast cancer: recent results and clinical implications.

    Science.gov (United States)

    Saha, Poornima; Nanda, Rita

    2016-09-01

    Triple-negative breast cancer (TNBC) is a heterogeneous disease in which tumors are defined by lack of expression of the estrogen receptor (ER), the progesterone receptor (PR), and the human epidermal growth factor receptor 2 (HER2) receptor. No targeted therapies are available for the treatment of TNBC, and chemotherapy remains the standard of care. Gene expression profiling has identified six distinct molecular subtypes of TNBC. The identification of novel targets, coupled with the development of therapies for different subsets of TNBC, holds great promise for the future treatment of this aggressive form of breast cancer. This review focuses on novel therapies in development for the treatment of TNBC.

  15. Approach to Perturbative QCD Results in Transition Amplitudes of Nucleon Negative-Parity Resonances

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-Bing

    2004-01-01

    The scaling behaviors of the nucleon resonance transition amplitudes from perturbative QCD (PQCD) are utilized to parametrize the amplitudes of the first negative-parity nucleon resonance S11 (1535). Our analysis indicates that the constraints of the transition amplitude for the S11 resonance at the limit Q2 →∞ by QCD sum rule calculations are not applicable at a moderate Q2 range of 2.5 ~ 4 Ge V2 compared with the present available data if the contribution of S11 is dominant in the Q2 limit.

  16. Negative feedback in ants: crowding results in less trail pheromone deposition.

    Science.gov (United States)

    Czaczkes, Tomer J; Grüter, Christoph; Ratnieks, Francis L W

    2013-04-06

    Crowding in human transport networks reduces efficiency. Efficiency can be increased by appropriate control mechanisms, which are often imposed externally. Ant colonies also have distribution networks to feeding sites outside the nest and can experience crowding. However, ants do not have external controllers or leaders. Here, we report a self-organized negative feedback mechanism, based on local information, which downregulates the production of recruitment signals in crowded parts of a network by Lasius niger ants. We controlled crowding by manipulating trail width and the number of ants on a trail, and observed a 5.6-fold reduction in the number of ants depositing trail pheromone from least to most crowded conditions. We also simulated crowding by placing glass beads covered in nest-mate cuticular hydrocarbons on the trail. After 10 bead encounters over 20 cm, forager ants were 45 per cent less likely to deposit pheromone. The mechanism of negative feedback reported here is unusual in that it acts by downregulating the production of a positive feedback signal, rather than by direct inhibition or the production of an inhibitory signal.

  17. Macrophage Migration Inhibitory Factor Promoter Polymorphisms (−794 CATT5–8 and −173 G>C): Relationship with mRNA Expression and Soluble MIF Levels in Young Obese Subjects

    Science.gov (United States)

    Matia-García, Inés; Salgado-Goytia, Lorenzo; Muñoz-Valle, José F.; García-Arellano, Samuel; Hernández-Bello, Jorge; Salgado-Bernabé, Aralia B.; Parra-Rojas, Isela

    2015-01-01

    We analyzed the relationship of −794 CATT5–8 and −173 G>C MIF polymorphisms with mRNA and soluble MIF in young obese subjects. A total of 250 young subjects, 150 normal-weight and 100 obese subjects, were recruited in the study. Genotyping of −794 CATT5–8 and −173 G>C MIF polymorphisms was performed by PCR and PCR-RFLP, respectively. MIF mRNA expression was determined by real-time PCR and serum MIF levels were measured using an ELISA kit. For both MIF promoter polymorphisms, no significant differences in the genotype and allele frequencies between groups were observed. MIF mRNA expression was slightly higher in obese subjects than in normal-weight subjects (1.38-fold), while soluble MIF levels did not show differences between groups. In addition, we found an increase in MIF mRNA expression in carriers of the 6,6 and C/C genotypes and the 6G haplotype of the −794 CATT5–8 and −173 G>C MIF polymorphisms, although it was not significant. In conclusion, this study found no relationship between obesity and MIF gene promoter polymorphisms with MIF mRNA expression in young obese subjects. PMID:25972622

  18. Macrophage Migration Inhibitory Factor Promoter Polymorphisms (−794 CATT5–8 and −173 G>C: Relationship with mRNA Expression and Soluble MIF Levels in Young Obese Subjects

    Directory of Open Access Journals (Sweden)

    Inés Matia-García

    2015-01-01

    Full Text Available We analyzed the relationship of −794 CATT5–8 and −173 G>C MIF polymorphisms with mRNA and soluble MIF in young obese subjects. A total of 250 young subjects, 150 normal-weight and 100 obese subjects, were recruited in the study. Genotyping of −794 CATT5–8 and −173 G>C MIF polymorphisms was performed by PCR and PCR-RFLP, respectively. MIF mRNA expression was determined by real-time PCR and serum MIF levels were measured using an ELISA kit. For both MIF promoter polymorphisms, no significant differences in the genotype and allele frequencies between groups were observed. MIF mRNA expression was slightly higher in obese subjects than in normal-weight subjects (1.38-fold, while soluble MIF levels did not show differences between groups. In addition, we found an increase in MIF mRNA expression in carriers of the 6,6 and C/C genotypes and the 6G haplotype of the −794 CATT5–8 and −173 G>C MIF polymorphisms, although it was not significant. In conclusion, this study found no relationship between obesity and MIF gene promoter polymorphisms with MIF mRNA expression in young obese subjects.

  19. Opportunities for improving triple-negative breast cancer outcomes: results of a population-based study.

    Science.gov (United States)

    Rapiti, Elisabetta; Pinaud, Kim; Chappuis, Pierre O; Viassolo, Valeria; Ayme, Aurélie; Neyroud-Caspar, Isabelle; Usel, Massimo; Bouchardy, Christine

    2017-03-01

    Triple-negative breast cancer (TNBC) is associated with a poor prognosis. Surgery, radiotherapy, chemotherapy, and referral for genetic counseling are the standard of care. We assessed TNBC prevalence, management, and outcome using data from the population-based Geneva cancer registry. 2591 women had a first invasive stage I-III breast cancer diagnosed between 2003 and 2011. We compared TNBC to other breast cancers (OBC) by χ(2) -test and logistic regression. Kaplan-Meier survival curves, up to 31-12-2014, were compared using log-rank test. TNBC risk of mortality overall (OS) and for breast cancer (BCSS) was evaluated through Cox models. Linkage with the Oncogenetics and Cancer Prevention Unit (OCPU) database of the Geneva University Hospitals provided genetic counseling information. TNBC patients (n = 192, 7.4%) were younger, more often born in Africa or Central-South America than OBC, had larger and more advanced tumors. 18% of TNBC patients did not receive chemotherapy. Thirty-one (17%) TNBC women consulted the OCPU, 39% among those aged <40 years. Ten-year survival was lower in TNBC than OBC (72% vs. 82% for BCSS; P < 0.001; 80% vs. 91% for OS; P < 0.001). The mortality risks remained significant after adjustment for other prognostic variables. The strongest determinants of mortality were age, place of birth, and lymph node status. A substantial proportion of TNBC patients in Geneva did not receive optimal care. Over 60% of eligible women did not receive genetic counseling and 18% did not receive chemotherapy. To improve TNBC prognosis, comprehensive care as recommended by standard guidelines should be offered to all patients.

  20. Cross sections and modelling results for TGF- and positron spectrum produced by a negative stepped lightning leader

    NARCIS (Netherlands)

    Köhn, C.; Ebert, U.

    2012-01-01

    We model the energy resolved angular distribution of TGFs and of positrons produced by a negative lightning leader stepping upwards in a thundercloud. First we present our new results for doubly differential cross sections for Bremsstrahlung and pair production based on the triply differential cross

  1. Oscillation for equations with positive and negative coefficients and with distributed delay I: General results

    Directory of Open Access Journals (Sweden)

    Leonid Berezansky

    2003-02-01

    Full Text Available We study a scalar delay differential equation with a bounded distributed delay, $$ dot{x}(t+ int_{h(t}^t x(s,d_s R(t,s - int_{g(t}^t x(s,d_s T(t,s=0, $$ where $R(t,s$, $T(t,s$ are nonnegative nondecreasing in $s$ for any $t$, $$ R(t,h(t=T(t,g(t=0, quad R(t,s geq T(t,s. $$ We establish a connection between non-oscillation of this differential equation and the corresponding differential inequalities, and between positiveness of the fundamental function and the existence of a nonnegative solution for a nonlinear integral inequality that constructed explicitly. We also present comparison theorems, and explicit non-oscillation and oscillation results. In a separate publication (part II, we will consider applications of this theory to differential equations with several concentrated delays, integrodifferential, and mixed equations.

  2. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

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    Jacques Luauté

    2012-01-01

    Full Text Available Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.

  3. Some results on the optimal depletion of exhaustible resources under negative discounting

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, T.

    1981-07-01

    This paper is concerned with finding necessary, and sufficient, conditions for the existence of a valuation finite optimal program for developing exhaustible resources. Three conditions are used for the existence theorem (Theorem 1). The first condition states that the effect of technical progress outweighs the effect of population growth (B.1). The second states that the utility function is bounded (B.2). The third essentially amounts to a condition on the rate at which utility must approach its upper bound as consumption goes to infinity, in relation to the consumption growth possibilities given by the production function, population growth and technical progress (B.3). Three necessary conditions are established for the existence of a valuation finite optimal program (Theorem 2). First, it is shown that if an optimal program exists (whether it is valuation finite or not) then the effect of technical progress must outweigh the effect of population growth. Second, if an optimal program exists, the utility function must be bounded (Condition B.2). The third condition expresses much the same restriction as (B.3), but in slightly weaker form. Examples are given which illustrate how Theorems 1 and 2 can be applied to cases where the utility function assumes parametric forms. Remarks following the Theorems relate the necessary, and sufficient conditions for existence of a valuation finite optimal program to the results on this issue in the existing literature. 10 references.

  4. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

    Science.gov (United States)

    Luauté, Jacques; Jacquin-Courtois, Sophie; O'Shea, Jacinta; Christophe, Laure; Rode, Gilles; Boisson, Dominique; Rossetti, Yves

    2012-01-01

    Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed. PMID:23050168

  5. Cyberbullying as a negative result of cyber-culture of Slovak children and adolescents: selected research findings

    Directory of Open Access Journals (Sweden)

    Hollá Katarína

    2016-05-01

    Full Text Available Cyber-culture points out the life in cyberspace and goes beyond national cultures. It is particularly attractive for the young people who use Information and Communications Technologies (ICT to express their attitudes, values, beliefs and thinking. Those do not need to be necessarily in accordance with the standards of an individual society. Cyberculture becomes dangerous. Great risk lies in cyberbullying that represents negative impact of cyber-culture on human behavior. The aim of the study is to detect cyberbullying as a negative impact of cyber-culture among of Slovak children and adolescents. The research was carried out on a sample of 1619 11-18-year old respondents (average age was 14.51. Results of cyberbullying research carried out using Latent Class Analysis (LCA have proved the appropriateness of 3-latent-class module. Relative entropy of the module reached 0.915. It was demonstrated that 52.9% of respondents belonged to the group of uninvolved, 42.7% were victims and 4.4% were victims-aggressors. Being a negative consequence of cyber-culture, cyberbullying is a challenge that educators - including other assisting professions - face when educating children and adolescents to orientate in cyberspace, behave responsibly, express themselves in a way that would not interfere others’ integrity and identity (personal and virtual. The study was written under VEGA MŠVVaŠ SR a SAV č. 1/0244/15: “Detekcia a riešenie kyberšikany”.

  6. False Negative NIPT Results: Risk Figures for Chromosomes 13, 18 and 21 Based on Chorionic Villi Results in 5967 Cases and Literature Review.

    Directory of Open Access Journals (Sweden)

    Diane Van Opstal

    Full Text Available Non-invasive prenatal testing (NIPT demonstrated a small chance for a false negative result. Since the "fetal" DNA in maternal blood originates from the cytotrophoblast of chorionic villi (CV, some false negative results will have a biological origin. Based on our experience with cytogenetic studies of CV, we tried to estimate this risk. 5967 CV samples of pregnancies at high risk for common aneuplodies were cytogenetically investigated in our centre between January 2000 and December 2011. All cases of fetal trisomy 13, 18 and 21 were retrospectively studied for the presence of a normal karyotype or mosaicism < 30% in short-term cultured (STC- villi. 404 cases of trisomies 13, 18 and 21 were found amongst 5967 samples (6,8%. Of these 404 cases, 14 (3,7% had a normal or low mosaic karyotype in STC-villi and therefore would potentially be missed with NIPT. It involved 2% (5/242 of all trisomy 21 cases and 7.3% (9/123 of all trisomy 18 cases. In 1:426 (14/5967 NIPT samples of patients at high risk for common aneuploidies, a trisomy 18 or 21 will potentially be missed due to the biological phenomenon of absence of the chromosome aberration in the cytotrophoblast.

  7. Comparison of ONIX simulation results with experimental data from the BATMAN testbed for the study of negative ion extraction

    Science.gov (United States)

    Mochalskyy, Serhiy; Fantz, Ursel; Wünderlich, Dirk; Minea, Tiberiu

    2016-10-01

    The development of negative ion (NI) sources for the ITER neutral beam injector is strongly accompanied by modelling activities. The ONIX (Orsay Negative Ion eXtraction) code simulates the formation and extraction of negative hydrogen ions and co-extracted electrons produced in caesiated sources. In this paper the 3D geometry of the BATMAN extraction system, and the source characteristics such as the extraction and bias potential, and the 3D magnetic field were integrated in the model. Calculations were performed using plasma parameters experimentally obtained on BATMAN. The comparison of the ONIX calculated extracted NI density with the experimental results suggests that predictive calculations of the extraction of NIs are possible. The results show that for an ideal status of the Cs conditioning the extracted hydrogen NI current density could reach ~30 mA cm-2 at 10 kV and ~20 mA cm-2 at 5 kV extraction potential, with an electron/NI current density ratio of about 1, as measured in the experiments under the same plasma and source conditions. The dependency of the extracted NI current on the NI density in the bulk plasma region from both the modeling and the experiment was investigated. The separate distributions composing the NI beam originating from the plasma bulk region and the PG surface are presented for different NI plasma volume densities and NI emission rates from the plasma grid (PG) wall, respectively. The extracted current from the NIs produced at the Cs covered PG surface, initially moving towards the bulk plasma and then being bent towards the extraction surfaces, is lower compared to the extracted NI current from directly extracted surface produced ions.

  8. The factor structure of the twelve item General Health Questionnaire (GHQ-12: the result of negative phrasing?

    Directory of Open Access Journals (Sweden)

    Hankins Matthew

    2008-04-01

    Full Text Available Abstract Background The 12-item General Health Questionnaire (GHQ-12 is used routinely as a unidimensional measure of psychological morbidity. Many factor-analytic studies have reported that the GHQ-12 has two or three dimensions, threatening its validity. It is possible that these 'dimensions' are the result of the wording of the GHQ-12, namely its division into positively phrased (PP and negatively phrased (NP statements about mood states. Such 'method effects' introduce response bias which should be taken into account when deriving and interpreting factors. Methods GHQ-12 data were obtained from the 2004 cohort of the Health Survey for England (N = 3705. Following exploratory factor analysis (EFA, the goodness of fit indices of one, two and three factor models were compared with those of a unidimensional model specifying response bias on the NP items, using structural equation modelling (SEM. The hypotheses were (1 the variance of the responses would be significantly higher for NP items than for PP items because of response bias, and (2 that the modelling of response bias would provide the best fit for the data. Results Consistent with previous reports, EFA suggested a two-factor solution dividing the items into NP and PP items. The variance of responses to the NP items was substantially and significantly higher than for the PP items. The model incorporating response bias was the best fit for the data on all indices (RMSEA = 0.068, 90%CL = 0.064, 0.073. Analysis of the frequency of responses suggests that the response bias derives from the ambiguity of the response options for the absence of negative mood states. Conclusion The data are consistent with the GHQ-12 being a unidimensional scale with a substantial degree of response bias for the negatively phrased items. Studies that report the GHQ-12 as multidimensional without taking this response bias into account risk interpreting the artefactual factor structure as denoting 'real' constructs

  9. Real-Time PCR for Measles Virus Detection on Clinical Specimens with Negative IgM Result in Morocco.

    Science.gov (United States)

    Benamar, Touria; Tajounte, Latifa; Alla, Amal; Khebba, Fatima; Ahmed, Hinda; Mulders, Mick N; Filali-Maltouf, Abdelkarim; El Aouad, Rajae

    2016-01-01

    Since the confirmation of measles cases represents an important indicator regarding the performance of the measles-elimination program, the aim of this study was to evaluate the effectiveness of the routine procedures followed in Morocco for the laboratory confirmation of measles cases. Suspected cases reported between January 2010 and December 2012 were assessed for the timeliness of the sample collection, occurrence of measles clinical symptoms, and the results of the laboratory diagnoses. For 88% of the 2,708 suspected cases, a clinical specimen was collected within 7d of rash onset, of which 50% were IgM-positive and 2.6% were equivocal. The measles symptoms were reported in 91.4% of the cases; the occurrence of symptoms showed a positive association with the serological results (odds ratio [OR] = 2.9883, 95% confidence interval [CI] 2.2238-4.0157). Of the negative samples, 52% (n = 116) tested positive by real-time polymerase chain reaction (PCR). These results are in favor of using molecular detection to complement serological diagnosis in the context of measles surveillance approach in Morocco. In addition, the introduction of additional laboratory methods for differential diagnosis is required for the final classification of suspected cases with maculopapular rash and fever in the context of the measles elimination program.

  10. Occurrence of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae isolates.

    Directory of Open Access Journals (Sweden)

    Peng Wang

    Full Text Available Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT. Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All produced extended spectrum β-lactamases (ESBLs but were susceptible to carbapenems. Antimicrobial susceptibility testing was performed by the disk diffusion and agar dilution methods. The MHT was performed using the standard inoculum of test organisms recommended by the CLSI. Genes that encoded ESBLs and carbapenemases were identified by PCR and DNA sequencing. Among the 301 clinical isolates, none of the isolates conformed to the criteria for carbapenemase screening recommended by the CLSI. The susceptibility rates for imipenem, meropenem, and ertapenem all were 100.0%, 100.0%, and 100.0%, respectively. Of the 301 E. coli and K. pneumoniae isolates, none produced carbapenemase. The MHT gave a positive result for 3.3% (10/301 of the isolates. False positive results can occur when the MHT is used to detect carbapenemase in ESBL-producing isolates and clinical laboratories must be aware of this fact.

  11. Follow-Up Study of Tuberculosis-Exposed Supermarket Customers with Negative Tuberculin Skin Test Results in Association with Positive Gamma Interferon Release Assay Results▿

    Science.gov (United States)

    Franken, Willeke P. J.; Koster, Ben F. P. J.; Bossink, Ailko W. J.; Thijsen, Steven F. T.; Bouwman, John J. M.; van Dissel, Jaap T.; Arend, Sandra M.

    2007-01-01

    We report a follow-up study of 29 subjects with negative tuberculin skin test (TST) results in association with positive gamma interferon release assay (IGRA) results, mainly due to responses to CFP-10 in the T-SPOT.TB assay, during a contact investigation. One year later, 12/29 subjects (41%) had converted to positive TST results in association with negative IGRA results. PMID:17626157

  12. Probability of a false-negative HIV antibody test result during the window period: a tool for pre- and post-test counselling.

    Science.gov (United States)

    Taylor, Darlene; Durigon, Monica; Davis, Heather; Archibald, Chris; Konrad, Bernhard; Coombs, Daniel; Gilbert, Mark; Cook, Darrel; Krajden, Mel; Wong, Tom; Ogilvie, Gina

    2015-03-01

    Failure to understand the risk of false-negative HIV test results during the window period results in anxiety. Patients typically want accurate test results as soon as possible while clinicians prefer to wait until the probability of a false-negative is virtually nil. This review summarizes the median window periods for third-generation antibody and fourth-generation HIV tests and provides the probability of a false-negative result for various days post-exposure. Data were extracted from published seroconversion panels. A 10-day eclipse period was used to estimate days from infection to first detection of HIV RNA. Median (interquartile range) days to seroconversion were calculated and probabilities of a false-negative result at various time periods post-exposure are reported. The median (interquartile range) window period for third-generation tests was 22 days (19-25) and 18 days (16-24) for fourth-generation tests. The probability of a false-negative result is 0.01 at 80 days' post-exposure for third-generation tests and at 42 days for fourth-generation tests. The table of probabilities of falsely-negative HIV test results may be useful during pre- and post-test HIV counselling to inform co-decision making regarding the ideal time to test for HIV.

  13. Integrative deficits in depression and in negative mood states as a result of fronto-parietal network dysfunctions.

    Science.gov (United States)

    Brzezicka, Aneta

    2013-01-01

    Depression is a disorder characterized not only by persistent negative mood, lack of motivation and a "ruminative" style of thinking, but also by specific deficits in cognitive functioning. These deficits are especially pronounced when integration of information is required. Previous research on linear syllogisms points to a clear pattern of cognitive disturbances present in people suffering from depressive disorders, as well as in people with elevated negative mood. Such disturbances are characterized by deficits in the integration of piecemeal information into coherent mental representations. In this review, I present evidence which suggests that the dysfunction of specific brain areas plays a crucial role in creating reasoning and information integration problems among people with depression and with heightened negative mood. As the increasingly prevalent systems neuroscience approach is spreading into the study of mental disorders, it is important to understand how and which brain networks are involved in creating certain symptoms of depression. Two large brain networks are of particular interest when considering depression: the default mode network (DMN) and the fronto-parietal (executive) network (FNP). The DMN network shows abnormally high activity in the depressed population, whereas FNP circuit activity is diminished. Disturbances within the FNP network seem to be strongly associated with cognitive problems in depression, especially those concerning executive functions. The dysfunctions within the fronto-parietal network are most probably connected to ineffective transmission of information between prefrontal and parietal regions, and also to an imbalance between FNP and DMN circuits. Inefficiency of this crucial circuits functioning may be a more general mechanism leading to problems with flexible cognition and executive functions, and could be the cause of more typical symptoms of depression like persistent rumination.

  14. Can We Reduce Negative Blood Cultures With Clinical Scores and Blood Markers? Results From an Observational Cohort Study.

    Science.gov (United States)

    Laukemann, Svenja; Kasper, Nina; Kulkarni, Prasad; Steiner, Deborah; Rast, Anna Christina; Kutz, Alexander; Felder, Susan; Haubitz, Sebastian; Faessler, Lukas; Huber, Andreas; Fux, Christoph A; Mueller, Beat; Schuetz, Philipp

    2015-12-01

    Only a small proportion of blood cultures routinely performed in emergency department (ED) patients is positive. Multiple clinical scores and biomarkers have previously been examined for their ability to predict bacteremia. Conclusive clinical validation of these scores and biomarkers is essential.This observational cohort study included patients with suspected infection who had blood culture sampling at ED admission. We assessed 5 clinical scores and admission concentrations of procalcitonin (PCT), C-reactive protein (CRP), lymphocyte and white blood cell counts, the neutrophil-lymphocyte count ratio (NLCR), and the red blood cell distribution width (RDW). Two independent physicians assessed true blood culture positivity. We used logistic regression models with area under the curve (AUC) analysis.Of 1083 patients, 104 (9.6%) had positive blood cultures. Of the clinical scores, the Shapiro score performed best (AUC 0.729). The best biomarkers were PCT (AUC 0.803) and NLCR (AUC 0.700). Combining the Shapiro score with PCT levels significantly increased the AUC to 0.827. Limiting blood cultures only to patients with either a Shapiro score of ≥4 or PCT > 0.1 μg/L would reduce negative sampling by 20.2% while still identifying 100% of positive cultures. Similarly, a Shapiro score ≥3 or PCT >0.25 μg/L would reduce cultures by 41.7% and still identify 96.1% of positive blood cultures.Combination of the Shapiro score with admission levels of PCT can help reduce unnecessary blood cultures with minimal false negative rates.The study was registered on January 9, 2013 at the 'ClinicalTrials.gov' registration web site (NCT01768494).

  15. Can We Reduce Negative Blood Cultures With Clinical Scores and Blood Markers? Results From an Observational Cohort Study

    Science.gov (United States)

    Laukemann, Svenja; Kasper, Nina; Kulkarni, Prasad; Steiner, Deborah; Rast, Anna Christina; Kutz, Alexander; Felder, Susan; Haubitz, Sebastian; Faessler, Lukas; Huber, Andreas; Fux, Christoph A.; Mueller, Beat; Schuetz, Philipp

    2015-01-01

    Abstract Only a small proportion of blood cultures routinely performed in emergency department (ED) patients is positive. Multiple clinical scores and biomarkers have previously been examined for their ability to predict bacteremia. Conclusive clinical validation of these scores and biomarkers is essential. This observational cohort study included patients with suspected infection who had blood culture sampling at ED admission. We assessed 5 clinical scores and admission concentrations of procalcitonin (PCT), C-reactive protein (CRP), lymphocyte and white blood cell counts, the neutrophil-lymphocyte count ratio (NLCR), and the red blood cell distribution width (RDW). Two independent physicians assessed true blood culture positivity. We used logistic regression models with area under the curve (AUC) analysis. Of 1083 patients, 104 (9.6%) had positive blood cultures. Of the clinical scores, the Shapiro score performed best (AUC 0.729). The best biomarkers were PCT (AUC 0.803) and NLCR (AUC 0.700). Combining the Shapiro score with PCT levels significantly increased the AUC to 0.827. Limiting blood cultures only to patients with either a Shapiro score of ≥4 or PCT > 0.1 μg/L would reduce negative sampling by 20.2% while still identifying 100% of positive cultures. Similarly, a Shapiro score ≥3 or PCT >0.25 μg/L would reduce cultures by 41.7% and still identify 96.1% of positive blood cultures. Combination of the Shapiro score with admission levels of PCT can help reduce unnecessary blood cultures with minimal false negative rates. The study was registered on January 9, 2013 at the ‘ClinicalTrials.gov’ registration web site (NCT01768494). PMID:26656373

  16. Warm Autoimmune Hemolytic Anemia and Direct Antiglobulin Testing With a False-Negative Result in a 53-Year-Old Man: The DAT Will Set You Free.

    Science.gov (United States)

    Losos, Michael; Hamad, Diane; Joshi, Sarita; Scrape, Scott; Chen, Jian

    2016-08-01

    Warm autoimmune hemolytic anemia (WAIHA), the most common of the relatively uncommon autoimmune-mediated hemolytic anemias (AIHAs), is mediated by polyclonal immunoglobulin (Ig)G autoantibodies in most cases. Herein, we present a case of WAIHA involving a direct antiglobulin test (DAT) with an initially negative result. Using a modified DAT protocol, repeat testing of the same specimen material from a previously healthy 53-year-old man yielded positive results. This case demonstrates that investigation of an apparently negative DAT result plays a critical role in the differential diagnosis of patients with rapidly progressing hemolytic anemia and the reversal of that decline.

  17. Dimethoate affects cholinesterases in Folsomia candida and their locomotion--false negative results of an avoidance behaviour test.

    Science.gov (United States)

    Pereira, Cecília M S; Novais, Sara C; Soares, Amadeu M V M; Amorim, Mónica J B

    2013-01-15

    The main mode of action of organophosphate insecticides is to inhibit acetylcholinesterase (AChE), which causes neuromuscular paralysis leading ultimately to death. The collembolan Folsomia candida is an important and standard test species in ecotoxicology, where effects on avoidance behaviour are assessed. Being related to insects they represent potential targets of insecticides such as the organophosphate dimethoate. In the present study we exposed F. candida to dimethoate having 2 main aims: 1) to assess the ability of F. candida to avoid it, and 2) to assess its effect on the cholinergic synapses to explore the link. For the latter, several sub-steps were needed: a) to characterise the existing ChE types and b) assess ChE activity (via exposure in vitro and in vivo). No avoidance was observed within the tested concentration range (0-0.32-1-3.2-10-32 mg/kg), in fact an apparent "attraction" (more animals on the spiked side) was observed. As expected, there was a significant decrease of AChE activities (AChE being the main ChE type) with an increase of dimethoate dose (IC(50)=1.4 mg/kg). Further, post-exposure video records showed that organisms were still alive in the spiked soil but lacked the locomotion ability (immobilised). The AChE inhibition correlated positively with immobilisation. Hence, this observation also showed that the apparent "attraction" behaviour observed in the avoidance test is rather a direct effect of not being able to escape due to paralysis hence a false-negative avoidance. This can constitute a confounding factor in an avoidance behaviour test and consequent interpretation, which is not accounted for at present.

  18. Prognostic value of HPV E6/E7 mRNA assay in women with negative colposcopy or CIN1 histology result: a follow-up study.

    Science.gov (United States)

    Giorgi Rossi, Paolo; Benevolo, Maria; Vocaturo, Amina; Caraceni, Donatella; Ciccocioppo, Lucia; Frega, Antonio; Terrenato, Irene; Zappacosta, Roberta; French, Deborah; Rosini, Sandra

    2013-01-01

    Pap test, and especially HPV DNA test, identify a large group of women who do not have any clinically relevant lesions, i.e., CIN2+ (Cervical Intraepithelial Neoplasia grade 2 or worse), but who are at greater risk of getting lesions in the future. The follow up of these women needs new biomarkers with prognostic value. The objective of this study is to evaluate the prognostic value of E6/E7 mRNA over-expression assay (PreTect HPV-Proofer, Norchip) for 5 HR-HPV types (16, 18, 31, 33, and 45) for progression to CIN2+ after a negative colposcopy. This prospective study, conducted at four Italian centres, enrolled 673 women with either a negative colposcopy or a negative or CIN1 histology. The clinical end-point was histological confirmation of CIN2+. Women were classified at baseline according to mRNA results and managed according to local colposcopy protocols. At least one conclusive follow-up test was obtained for 347 women (25 months average lapse since recruitment, range 5-74). Only seven CIN2+ were detected during follow up, three among the 82 women positive for mRNA at baseline, two among the 250 negative (Fisher exact test, p = 0.02), and two among the 12 with an invalid test. Absolute CIN2+ risk was 6.7/1,000 person/years in the whole cohort. The absolute CIN2+ risk was 18.4/1,000 person/years and 3.6/1,000 person/years in mRNA-positive and mRNA-negative women, respectively. In conclusion, E6/E7 mRNA over-expression appears to be a good candidate as a prognostic biomarker to manage HR-HPV DNA-positive women with negative colposcopy or histology, particularly in order to decrease follow-up intensity in those who are negative.

  19. Prognostic value of HPV E6/E7 mRNA assay in women with negative colposcopy or CIN1 histology result: a follow-up study.

    Directory of Open Access Journals (Sweden)

    Paolo Giorgi Rossi

    Full Text Available Pap test, and especially HPV DNA test, identify a large group of women who do not have any clinically relevant lesions, i.e., CIN2+ (Cervical Intraepithelial Neoplasia grade 2 or worse, but who are at greater risk of getting lesions in the future. The follow up of these women needs new biomarkers with prognostic value. The objective of this study is to evaluate the prognostic value of E6/E7 mRNA over-expression assay (PreTect HPV-Proofer, Norchip for 5 HR-HPV types (16, 18, 31, 33, and 45 for progression to CIN2+ after a negative colposcopy. This prospective study, conducted at four Italian centres, enrolled 673 women with either a negative colposcopy or a negative or CIN1 histology. The clinical end-point was histological confirmation of CIN2+. Women were classified at baseline according to mRNA results and managed according to local colposcopy protocols. At least one conclusive follow-up test was obtained for 347 women (25 months average lapse since recruitment, range 5-74. Only seven CIN2+ were detected during follow up, three among the 82 women positive for mRNA at baseline, two among the 250 negative (Fisher exact test, p = 0.02, and two among the 12 with an invalid test. Absolute CIN2+ risk was 6.7/1,000 person/years in the whole cohort. The absolute CIN2+ risk was 18.4/1,000 person/years and 3.6/1,000 person/years in mRNA-positive and mRNA-negative women, respectively. In conclusion, E6/E7 mRNA over-expression appears to be a good candidate as a prognostic biomarker to manage HR-HPV DNA-positive women with negative colposcopy or histology, particularly in order to decrease follow-up intensity in those who are negative.

  20. Efficacy of bilateral repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia : results of a multicenter double-blind randomized controlled trial

    NARCIS (Netherlands)

    Dlabac-de Lange, J. J.; Bais, L.; van Es, F. D.; Visser, B. G. J.; Reinink, E.; Bakker, B.; van den Heuvel, E. R.; Aleman, A.; Knegtering, H.

    2015-01-01

    Background. Few studies have investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for negative symptoms of schizophrenia, reporting inconsistent results. We aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3 w

  1. Genetic antimicrobial susceptibility testing in Gram-negative sepsis - impact on time to results in a routine laboratory.

    Science.gov (United States)

    Kommedal, Øyvind; Aasen, Johanne Lind; Lindemann, Paul Christoffer

    2016-07-01

    Diagnostic testing of positive blood cultures is among the most critical tasks performed by clinical microbiology laboratories, and the total analysis time from sampling to results should be kept as short as possible. By providing identification of pelleted bacteria directly from positive blood-cultures, MALDI-TOF MS opens for relatively low-complex species-adjusted genetic susceptibility testing from the same bacterial pellet. In our lab routine, we prospectively evaluated a rapid in-house real-time PCR targeting the most common aminoglycoside and cephalosporin resistance genes in Escherichia coli and Klebsiella pneumoniae and measured time to preliminary susceptibility reporting for 138 samples. The results were compared to direct phenotypic susceptibility testing with interpretation after 6 h and overnight incubation respectively. Results from the genetic susceptibility testing were available for 69.5% (96/138) of the positive blood cultures within 24 h after sample collection. No phenotypic susceptibility results were available at this time. Compared to overnight direct susceptibility testing, the average time from sample collection to preliminary susceptibility reporting was reduced with 43%, from 45 h and 5 min to 25 h and 44 min, providing an earlier adjustment of antimicrobial therapy for 12 patients. Minor logistic adjustments have the potential to save yet another 4 h.

  2. Pegylated interferon in HBeAg-positive and -negative chronic hepatitis B patients: post-treatment 1-year results of three Turkish centres.

    Science.gov (United States)

    Yamazhan, Tansu; Kurtaran, Behice; Pullukçu, Hüsnü; Yüksel, Esma; Özkaya, Deniz; Taşbakan, Meltem Işıkgöz; Sipahi, Oğuz Reşat; Durusoy, Raika; Aksu, Hasan Salih Zeki

    2014-12-01

    In this study, we aimed to evaluate the 1-year post-treatment follow-up results of 112 patients who received pegylated interferon (PEG-IFN) for 52 weeks. HBeAg negativity/seroconversion and/or negative HBV-DNA at the end of the treatment were considered as response. Patients who had response at the end of treatment but had HBV-DNA breakthrough during 1-year follow-up were considered as relapse. The study group comprised 112 cases (34 HBeAg-positive, 78 HBeAg-negative). In HBeAg-positive and -negative cases, end-of-treatment response rates were 2·9% and 60·2%, whereas 1-year sustained virological response rates were 0 and 33·3%, respectively. When we compared relapse cases versus cases with response at the end of 1-year follow-up, being female and having low viral load were the two parameters associated with higher response rates (Chi-square, P  =  0·028; Mann-Whitney U test, P  =  0·023). Overall non-response rates to PEG-IFN were high (57·1%). Results in HBeAg-positive cases were disappointing.

  3. Factors that Predict Negative Results of QuantiFERON-TB Gold In-Tube Test in Patients with Culture-Confirmed Tuberculosis: A Multicenter Retrospective Cohort Study.

    Directory of Open Access Journals (Sweden)

    Yong-Soo Kwon

    Full Text Available Interferon-γ release assays such as the QuantiFERON-TB Gold In-Tube Test (QFT-GIT are designed to detect Mycobacterium tuberculosis infections, whether latent or manifesting as disease. However, a substantial number of persons with culture-confirmed tuberculosis (TB have negative QFT-GITs. Information on host factors contributing to false-negative and indeterminate results are limited.A multicenter retrospective cohort study was performed with 1,264 culture-confirmed TB patients older than 18 years who were subjected to the QFT-GIT at one of the six hospitals between May 2007 and February 2014. Patients with human immunodeficiency virus infection were excluded. Clinical and laboratory data were collected in South Korea.Of all patients, 87.6% (1,107/1,264 were diagnosed with pulmonary TB and 12.4% (157/1,264 with extrapulmonary TB. The rate of negative results was 14.4% (182/1,264. The following factors were highly correlated with false-negative results in the QFT-GIT: advanced age (age ≥ 65 years, odds ratio [OR] 1.57, 95% confidence interval [CI] 1.03-2.39, bilateral disease as determined by chest radiography (OR 1.75, 95% CI 1.13-2.72, malignancy (OR 2.42, 95% CI 1.30-4.49, and lymphocytopenia (total lymphocyte count < 1.0 × 109/L, OR 1.86, 95% CI 1.21-2.87.Consequently, QFT-GIT results need to be interpreted with caution in patients with these host risk factors such as the elderly, bilateral disease on chest radiography, or malignancy, or lymphocytopenia.

  4. Antimicrobial activity of ceftobiprole against Gram-negative and Gram-positive pathogens: results from INVITA-A-CEFTO Brazilian study

    Directory of Open Access Journals (Sweden)

    Rosângela Ferraz Cereda

    2011-08-01

    Full Text Available Ceftobiprole is a broad-spectrum cephalosporin with potent activity against staphylococci, including those resistant to oxacillin, as well as against most Gram-negative bacilli including Pseudomonas aeruginosa. In this study, the in vitro activity of ceftobiprole and comparator agents was tested against bacterial isolates recently collected from Brazilian private hospitals. A total of 336 unique bacterial isolates were collected from hospitalized patients between February 2008 and August 2009. Each hospital was asked to submit 100 single bacterial isolates responsible for causing blood, lower respiratory tract or skin and soft tissue infections. Bacterial identification was confirmed and antimicrobial susceptibility testing was performed using CLSI microdilution method at a central laboratory. The CLSI M100-S21 (2011 was used for interpretation of the antimicrobial susceptibility results. Among the 336 pathogens collected, 255 (75.9% were Gram-negative bacilli and 81 (24.1% were Gram-positive cocci. Although ceftobiprole MIC50 values for oxacillin resistant strains were two-fold higher than for methicillin susceptible S. aureus, ceftobiprole inhibited 100% of tested S. aureus at MICs 6 µg/mL for both species. Our results showed that ceftobiprole has potent activity against staphylococci and E. faecalis, which was superior to that of vancomycin. Our data also indicates that ceftobiprole demonstrated potency comparable to that of cefepime and ceftazidime against key Gram-negative species.

  5. Antimicrobial activity of ceftobiprole against gram-negative and gram-positive pathogens: results from INVITA-A-CEFTO Brazilian study.

    Science.gov (United States)

    Cereda, Rosângela Ferraz; Azevedo, Heber Dias; Girardello, Raquel; Xavier, Danilo Elias; Gales, Ana C

    2011-01-01

    Ceftobiprole is a broad-spectrum cephalosporin with potent activity against staphylococci, including those resistant to oxacillin, as well as against most gram-negative bacilli including Pseudomonas aeruginosa. In this study, the in vitro activity of ceftobiprole and comparator agents was tested against bacterial isolates recently collected from Brazilian private hospitals. A total of 336 unique bacterial isolates were collected from hospitalized patients between February 2008 and August 2009. Each hospital was asked to submit 100 single bacterial isolates responsible for causing blood, lower respiratory tract or skin and soft tissue infections. Bacterial identification was confirmed and antimicrobial susceptibility testing was performed using CLSI microdilution method at a central laboratory. The CLSI M100-S21 (2011) was used for interpretation of the antimicrobial susceptibility results. Among the 336 pathogens collected, 255 (75.9%) were gram-negative bacilli and 81 (24.1%) were gram-positive cocci. Although ceftobiprole MIC50 values for oxacillin resistant strains were two-fold higher than for methicillin susceptible S. aureus, ceftobiprole inhibited 100% of tested S. aureus at MICs ceftobiprole MIC50 > 6 µg/mL for both species. Our results showed that ceftobiprole has potent activity against staphylococci and E. faecalis, which was superior to that of vancomycin. Our data also indicates that ceftobiprole demonstrated potency comparable to that of cefepime and ceftazidime against key gram-negative species.

  6. Suppression of telomere-binding protein TPP1 resulted in telomere dysfunction and enhanced radiation sensitivity in telomerase-negative osteosarcoma cell line

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Weiguang [Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital, Wuhan University, Wuhan (China); Department of Oncology, The Third Affiliated Hospital, Soochow University, Changzhou (China); Wu, Qinqin [Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital, Wuhan University, Wuhan (China); Department of Radiation Oncology, Changzhou Tumor Hospital, Soochow University, Changzhou (China); Zhou, Fuxiang; Xie, Conghua [Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital, Wuhan University, Wuhan (China); Wu, Changping, E-mail: wcpzlk@163.com [Department of Oncology, The Third Affiliated Hospital, Soochow University, Changzhou (China); Zhou, Yunfeng, E-mail: yfzhouwhu@163.com [Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital, Wuhan University, Wuhan (China)

    2014-03-07

    Highlights: • Down-regulation of TPP1 shortened telomere length in telomerase-negative cells. • Down-regulation of TPP1 induced cell apoptosis in telomerase-negative cells. • Down-regulation of TPP1 increased radiosensitivity in telomerase-negative cells. - Abstract: Mammalian telomeres are protected by the shelterin complex that contains the six core proteins POT1, TPP1, TIN2, TRF1, TRF2 and RAP1. TPP1, formerly known as TINT1, PTOP, and PIP1, is a key factor that regulates telomerase recruitment and activity. In addition to this, TPP1 is required to mediate the shelterin assembly and stabilize telomere. Previous work has found that TPP1 expression was elevated in radioresistant cells and that overexpression of TPP1 led to radioresistance and telomere lengthening in telomerase-positive cells. However, the exact effects and mechanism of TPP1 on radiosensitivity are yet to be precisely defined in the ALT cells. Here we report on the phenotypes of the conditional deletion of TPP1 from the human osteosarcoma U2OS cells using ALT pathway to extend the telomeres.TPP1 deletion resulted in telomere shortening, increased apoptosis and radiation sensitivity enhancement. Together, our findings show that TPP1 plays a vital role in telomere maintenance and protection and establish an intimate relationship between TPP1, telomere and cellular response to ionizing radiation, but likely has the specific mechanism yet to be defined.

  7. Effectiveness of Trivalent Inactivated Influenza Vaccine in Children Estimated by a Test-Negative Case-Control Design Study Based on Influenza Rapid Diagnostic Test Results.

    Science.gov (United States)

    Shinjoh, Masayoshi; Sugaya, Norio; Yamaguchi, Yoshio; Tomidokoro, Yuka; Sekiguchi, Shinichiro; Mitamura, Keiko; Fujino, Motoko; Shiro, Hiroyuki; Komiyama, Osamu; Taguchi, Nobuhiko; Nakata, Yuji; Yoshida, Naoko; Narabayashi, Atsushi; Myokai, Michiko; Sato, Masanori; Furuichi, Munehiro; Baba, Hiroaki; Fujita, Hisayo; Sato, Akihiro; Ookawara, Ichiro; Tsunematsu, Kenichiro; Yoshida, Makoto; Kono, Mio; Tanaka, Fumie; Kawakami, Chiharu; Kimiya, Takahisa; Takahashi, Takao; Iwata, Satoshi

    2015-01-01

    We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013-14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38 °C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39-52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56-69), 77% (95% CI, 59-87), and 26% (95% CI, 14-36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B.

  8. Chagasic thymic atrophy does not affect negative selection but results in the export of activated CD4+CD8+ T cells in severe forms of human disease.

    Directory of Open Access Journals (Sweden)

    Alexandre Morrot

    2011-08-01

    Full Text Available Extrathymic CD4+CD8+ double-positive (DP T cells are increased in some pathophysiological conditions, including infectious diseases. In the murine model of Chagas disease, it has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment and the lymphoid compartment. In the acute phase, this results in a severe atrophy of the organ and early release of DP cells into the periphery. To date, the effect of the changes promoted by the parasite infection on thymic central tolerance has remained elusive. Herein we show that the intrathymic key elements that are necessary to promote the negative selection of thymocytes undergoing maturation during the thymopoiesis remains functional during the acute chagasic thymic atrophy. Intrathymic expression of the autoimmune regulator factor (Aire and tissue-restricted antigen (TRA genes is normal. In addition, the expression of the proapoptotic Bim protein in thymocytes was not changed, revealing that the parasite infection-induced thymus atrophy has no effect on these marker genes necessary to promote clonal deletion of T cells. In a chicken egg ovalbumin (OVA-specific T-cell receptor (TCR transgenic system, the administration of OVA peptide into infected mice with thymic atrophy promoted OVA-specific thymocyte apoptosis, further indicating normal negative selection process during the infection. Yet, although the intrathymic checkpoints necessary for thymic negative selection are present in the acute phase of Chagas disease, we found that the DP cells released into the periphery acquire an activated phenotype similar to what is described for activated effector or memory single-positive T cells. Most interestingly, we also demonstrate that increased percentages of peripheral blood subset of DP cells exhibiting an activated HLA-DR+ phenotype are associated with severe cardiac forms of human chronic Chagas disease. These cells may

  9. Implementation of the Bacillus cereus microbiological plate used for the screening of tetracyclines in raw milk samples with STAR protocol - the problem with false-negative results solved.

    Science.gov (United States)

    Raspor Lainšček, P; Biasizzo, M; Henigman, U; Dolenc, J; Kirbiš, A

    2014-01-01

    In antibiotic residue analyses the first step of screening is just as important as the following steps. Screening methods need to be quick and inexpensive, but above all sensitive enough to detect the antibiotic residue at or below the maximum residue limit (MRL). In the case of a positive result, the next step is conducted and further methods are used for confirmation. MRLs stated in European Union Regulation 37/2010 for tetracyclines in raw milk are: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 100 µg kg(-1) for chlortetracycline and no limit for doxycycline because it is prohibited for use in animals from which milk is produced for human consumption. The current five-plate microbiological screening method for the detection of antibiotic residues in raw milk was found to be simple and inexpensive, but not specific, sensitive and reliable enough to detect tetracycline at MRL in routine raw milk screening procedures. Spiking samples with tetracycline at the MRL level and applying them on Bacillus cereus ATCC 11778 microbiological plates often gave false-negative results, indicating that tetracyclines may have to be inactivated or masked. Tetracyclines seem to bind to a certain component in milk. Consequently, when applying samples to the B. cereus microbiological plate the antibiotic cannot inhibit the growth of B. cereus which disables the formation of inhibition zones on the test plate. After adding the appropriate amount of citric acid into the milk samples, we solved the problem of false-negative results. During the validation 79 samples of milk were spiked with tetracyclines at different concentrations: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 80 µg kg(-1) for chlortetracycline and 30 µg kg(-1) for doxycycline. Concentrations used in the validation matched the requirements for MRLs (they were either at or below the MRLs) stated in European Union Regulation 37/2010. The sensitivity of the validation was 100%.

  10. Hot topic: Bovine milk samples yielding negative or nonspecific results in bacterial culturing--the possible role of PCR-single strand conformation polymorphism in mastitis diagnosis.

    Science.gov (United States)

    Schwaiger, K; Wimmer, M; Huber-Schlenstedt, R; Fehlings, K; Hölzel, C S; Bauer, J

    2012-01-01

    A large proportion of mastitis milk samples yield negative or nonspecific results (i.e., no mastitis pathogen can be identified) in bacterial culturing. Therefore, the culture-independent PCR-single strand conformation polymorphism method was applied to the investigation of bovine mastitis milk samples. In addition to the known mastitis pathogens, the method was suitable for the detection of fastidious bacteria such as Mycoplasma spp., which are often missed by conventional culturing methods. The detection of Helcococcus ovis in 4 samples might indicate an involvement of this species in pathogenesis of bovine mastitis. In conclusion, PCR-single-strand conformation polymorphism is a promising tool for gaining new insights into the bacteriological etiology of mastitis.

  11. Lack of a Negative Effect of BCG-Vaccination on Child Psychomotor Development: Results from the Danish Calmette Study - A Randomised Clinical Trial

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper; Stensballe, Lone Graff; Birk, Nina Marie;

    2016-01-01

    MEASURES: Psychomotor development measured using Ages and Stages Questionnaire (ASQ) completed by the parents at 12 months. Additionally, parents of premature children (gestational age Developmental assessment was available for 3453/4262 (81%). RESULTS......OBJECTIVES: To assess the non-specific effect of Bacillus Calmette-Guérin (BCG) vaccination at birth on psychomotor development. DESIGN: This is a pre-specified secondary outcome from a randomised, clinical trial. SETTING: Maternity units and paediatric wards at three university hospitals...... was -7.8 points (-20.6 to 5.0, p = 0.23), d = -0.23 (-0.62 to 0.15). CONCLUSIONS: A negative non-specific effect of BCG vaccination at birth on psychomotor development was excluded in term children. TRIAL REGISTRATION: ClinicalTrials.gov NCT01694108....

  12. Multiplanar spiral CT enterography in patients with Crohn's disease using a negative oral contrast material: initial results of a noninvasive imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Reittner, Pia; Goritschnig, Toria; Doerfler, Otto [Department of Radiology, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Petritsch, Wolfgang; Hinterleitner, Thomas [Department of Internal Medicine, Karl Franzens Medical School and University Hospital Graz, Auenbruggerplatz 9, 8036 Graz (Austria); Preidler, Klaus W.; Szolar, Dieter H. [Diagnostikum Graz Sued West, Weblinger Guertel 25, 8054 Graz (Austria)

    2002-09-01

    The aim of this study was to prospectively define the role of multiplanar spiral CT enterography with a new negative oral contrast material for noninvasive assessment of the small bowel in patients with Crohn's disease. Thirty patients with established Crohn's disease prospectively underwent spiral CT enterography at 45-60 min after distension of the small bowel with 1400 ml of a negative oral contrast material (Mucofalk water enema). Spiral CT scans were obtained 50 s after administration of intravenous contrast material with the following parameters: 5-mm collimation; 7.5-mm/s table feed; and 3-mm reconstruction interval. The adequacy of bowel opacification, luminal distension, and the contribution of two-dimensional multiplanar reformatted imaging were assessed by two observers. Spiral CT imaging findings were compared with results of enteroclysis as well as endoscopic and histological findings in all patients. Spiral CT enterography with Mucofalk water enema was well tolerated in 29 of 30 patients. Findings on spiral CT enterography were comparable with those of barium studies in 25 of 30 patients, superior to those on barium studies in 4 patients, and inferior in 1 patient (p<0.05). The addition of multiplanar reformatted images to axial spiral CT scans significantly improved observers' confidence in image interpretation (p<0.05) but did not reveal additional abnormalities. Multiplanar spiral CT enterography with Mucofalk excellently provides information in patients with Crohn's disease. This technique accurately depicts the level of small bowel obstruction and the extent of inflammatory small bowel disease and its extraluminal complications. (orig.)

  13. Cognitive Effects of High-Frequency rTMS in Schizophrenia Patients With Predominant Negative Symptoms: Results From a Multicenter Randomized Sham-Controlled Trial.

    Science.gov (United States)

    Hasan, Alkomiet; Guse, Birgit; Cordes, Joachim; Wölwer, Wolfgang; Winterer, Georg; Gaebel, Wolfgang; Langguth, Berthold; Landgrebe, Michael; Eichhammer, Peter; Frank, Elmar; Hajak, Göran; Ohmann, Christian; Verde, Pablo E; Rietschel, Marcella; Ahmed, Raees; Honer, William G; Malchow, Berend; Karch, Susanne; Schneider-Axmann, Thomas; Falkai, Peter; Wobrock, Thomas

    2016-05-01

    Cognitive impairments are one of the main contributors to disability and poor long-term outcome in schizophrenia. Proof-of-concept trials indicate that repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) has the potential to improve cognitive functioning. We analyzed the effects of 10-Hz rTMS to the left DLPFC on cognitive deficits in schizophrenia in a large-scale and multicenter, sham-controlled study. A total of 156 schizophrenia patients with predominant negative symptoms were randomly assigned to a 3-week intervention (10-Hz rTMS, 15 sessions, 1000 stimuli per session) with either active or sham rTMS. The Rey Auditory Verbal Learning Test, Trail Making Test A and B, Wisconsin Card Sorting Test, Digit Span Test, and the Regensburg Word Fluency Test were administered before intervention and at day 21, 45, and 105 follow-up. From the test results, a neuropsychological composite score was computed. Both groups showed no differences in any of the outcome variables before and after intervention. Both groups improved markedly over time, but effect sizes indicate a numeric, but nonsignificant superiority of active rTMS in certain cognitive tests. Active 10-Hz rTMS applied to the left DLPFC for 3 weeks was not superior to sham rTMS in the improvement of various cognitive domains in schizophrenia patients with predominant negative symptoms. This is in contrast to previous preliminary proof-of-concept trials, but highlights the need for more multicenter randomized controlled trials in the field of noninvasive brain stimulation.

  14. An undetectable source of technical error that could lead to false negative results in enzyme linked immunosorbent assay of antibodies to HIV-1.

    Science.gov (United States)

    Wiltbank, T B; McCarroll, D R; Wartick, M G

    1989-01-01

    Since the institution of routine testing for antibodies to Human Immunodeficiency Virus (HIV) using the enzyme-linked immunosorbent assay (ELISA), the specificity and sensitivity of this assay system has received significant scrutiny. During previous use of this methodology, we have quantified rates of false biological positive results using commercial kit assays in a normal donor population. In this study, we have identified a potential source for false negative results. Using multiple lots of two different commercial ELISA kits, the absorbance readings at the test end point could not differentiate between normal non-reactive donor samples and blanks containing no sample. These results occur using normal donor samples, even though the assays could distinguish between blank wells and the manufacturers' "normal controls", provided with the assay. Our findings suggest that a technical pipetting error is presently undetectable, either visually or by statistical methods, and could permit an untested, potentially HIV-1 positive, unit to be released into the transfusable blood supply. A possible solution is suggested.

  15. The enhanced healing of a high-risk, clean, sutured surgical incision by prophylactic negative pressure wound therapy as delivered by Prevena™ Customizable™: cosmetic and therapeutic results.

    Science.gov (United States)

    Scalise, Alessandro; Tartaglione, Caterina; Bolletta, Elisa; Calamita, Roberto; Nicoletti, Giovanni; Pierangeli, Marina; Grassetti, Luca; Di Benedetto, Giovanni

    2015-04-01

    According to the literature, incisional closure complications may range from postoperative surgical site infections, representing 17-22% of health care-associated infections, surgical wound dehiscence and formation of haematomas or seromas, and can lead to delayed or impaired incision healing. These kinds of situations are more common when wounds are closed under tension or in specific patient morbidities. Obesity, in particular, is associated with an impaired blood flow to tissues, predisposing the patient to increased risk of wound complications by various mechanisms. Incisional complications can become relevant economic burdens for health care systems because of an increase in the average length of hospital stay and readmissions, and additional medical and surgical procedures. Thus, a preventive therapy may have a critical role in the management of healing. Negative pressure wound therapy (NPWT) technology as delivered by Prevena™ Customizable™ (Kinetic Concepts Inc., San Antonio, TX) has recently been the focus of a new investigation, as a prophylactic measure to prevent complications via immediate postoperative application in high-risk, clean, closed surgical incisions. The authors present a 62-year-old class II obese female, who underwent bilateral inguinal dermolipectomy. Prophylactic NPWT as delivered by Prevena™ was performed successfully over surgical incisions. Cosmetic and therapeutic results are shown.

  16. Time Interval From Breast-Conserving Surgery to Breast Irradiation in Early Stage Node-Negative Breast Cancer: 17-Year Follow-Up Results and Patterns of Recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Vujovic, Olga, E-mail: olga.vujovic@lhsc.on.ca [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario (Canada); Yu, Edward [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario (Canada); Cherian, Anil [Station Health Centre, Royal Air Force Lossiemouth, Moray (United Kingdom); Dar, A. Rashid [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario (Canada); Stitt, Larry [Department of Biometry, London Regional Cancer Program, London, Ontario (Canada); Perera, Francisco [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario (Canada)

    2015-02-01

    Purpose: A retrospectivechart review was conducted to determine whether the time interval from breast-conserving surgery to breast irradiation (surgery-radiation therapy interval) in early stage node-negative breast cancer had any detrimental effects on recurrence rates. Methods and Materials: There were 566 patients with T1 to T3, N0 breast cancer treated with breast-conserving surgery and breast irradiation and without adjuvant systemic treatment between 1985 and 1992. The surgery-to-radiation therapy intervals used for analysis were 0 to 8 weeks (201 patients), >8 to 12 weeks (233 patients), >12 to 16 weeks (91 patients), and >16 weeks (41 patients). Kaplan-Meier estimates of time to local recurrence, disease-free survival, distant disease-free survival, cause-specific survival, and overall survival rates were calculated. Results: Median follow-up was 17.4 years. Patients in all 4 time intervals were similar in terms of characteristics and pathologic features. There were no statistically significant differences among the 4 time groups in local recurrence (P=.67) or disease-free survival (P=.82). The local recurrence rates at 5, 10, and 15 years were 4.9%, 11.5%, and 15.0%, respectively. The distant disease relapse rates at 5, 10, and 15 years were 10.6%, 15.4%, and 18.5%, respectively. The disease-free failure rates at 5, 10, and 15 years were 20%, 32.3%, and 39.8%, respectively. Cause-specific survival rates at 5, 10, and 15 years were 92%, 84.6%, and 79.8%, respectively. The overall survival rates at 5, 10, and 15 years were 89.3%, 79.2%, and 66.9%, respectively. Conclusions: Surgery-radiation therapy intervals up to 16 weeks from breast-conserving surgery are not associated with any increased risk of recurrence in early stage node-negative breast cancer. There is a steady local recurrence rate of 1% per year with adjuvant radiation alone.

  17. Culture Negative Listeria monocytogenes Meningitis Resulting in Hydrocephalus and Severe Neurological Sequelae in a Previously Healthy Immunocompetent Man with Penicillin Allergy

    Directory of Open Access Journals (Sweden)

    Shahin Gaini

    2015-01-01

    Full Text Available A previously healthy 74-year-old Caucasian man with penicillin allergy was admitted with evolving headache, confusion, fever, and neck stiffness. Treatment for bacterial meningitis with dexamethasone and monotherapy ceftriaxone was started. The cerebrospinal fluid showed negative microscopy for bacteria, no bacterial growth, and negative polymerase chain reaction for bacterial DNA. The patient developed hydrocephalus on a second CT scan of the brain on the 5th day of admission. An external ventricular catheter was inserted and Listeria monocytogenes grew in the cerebrospinal fluid from the catheter. The patient had severe neurological sequelae. This case report emphasises the importance of covering empirically for Listeria monocytogenes in all patients with penicillin allergy with suspected bacterial meningitis. The case also shows that it is possible to have significant infection and inflammation even with negative microscopy, negative cultures, and negative broad range polymerase chain reaction in cases of Listeria meningitis. Follow-up spinal taps can be necessary to detect the presence of Listeria monocytogenes.

  18. Overexpression of sICAM-1 in the Alveolar Epithelial Space Results in an Exaggerated Inflammatory Response and Early Death in Gram Negative Pneumonia

    Directory of Open Access Journals (Sweden)

    Curtis Jeffery L

    2011-01-01

    Full Text Available Abstract Background A sizeable body of data demonstrates that membrane ICAM-1 (mICAM-1 plays a significant role in host defense in a site-specific fashion. On the pulmonary vascular endothelium, mICAM-1 is necessary for normal leukocyte recruitment during acute inflammation. On alveolar epithelial cells (AECs, we have shown previously that the presence of normal mICAM-1 is essential for optimal alveolar macrophage (AM function. We have also shown that ICAM-1 is present in the alveolar space as a soluble protein that is likely produced through cleavage of mICAM-1. Soluble intercellular adhesion molecule-1 (sICAM-1 is abundantly present in the alveolar lining fluid of the normal lung and could be generated by proteolytic cleavage of mICAM-1, which is highly expressed on type I AECs. Although a growing body of data suggesting that intravascular sICAM-1 has functional effects, little is known about sICAM-1 in the alveolus. We hypothesized that sICAM-1 in the alveolar space modulates the innate immune response and alters the response to pulmonary infection. Methods Using the surfactant protein C (SPC promoter, we developed a transgenic mouse (SPC-sICAM-1 that constitutively overexpresses sICAM-1 in the distal lung, and compared the responses of wild-type and SPC-sICAM-1 mice following intranasal inoculation with K. pneumoniae. Results SPC-sICAM-1 mice demonstrated increased mortality and increased systemic dissemination of organisms compared with wild-type mice. We also found that inflammatory responses were significantly increased in SPC-sICAM-1 mice compared with wild-type mice but there were no difference in lung CFU between groups. Conclusions We conclude that alveolar sICAM-1 modulates pulmonary inflammation. Manipulating ICAM-1 interactions therapeutically may modulate the host response to Gram negative pulmonary infections.

  19. Antimicrobial susceptibility trends among gram-positive and -negative clinical isolates collected between 2005 and 2012 in Mexico: results from the Tigecycline Evaluation and Surveillance Trial

    OpenAIRE

    Morfin-Otero, Rayo; Noriega, Eduardo Rodriguez; Dowzicky, Michael J.

    2015-01-01

    Background The Tigecycline Evaluation and Surveillance Trial (T.E.S.T) is a global antimicrobial surveillance study of both gram-positive and gram-negative organisms. This report presents data on antimicrobial susceptibility among organisms collected in Mexico between 2005 and 2012 as part of T.E.S.T., and compares rates between 2005–2007 and 2008–2012. Method Each center in Mexico submitted at least 200 isolates per collection year; including 65 gram-positive isolates and 135 gram-negative i...

  20. Culture Negative Listeria monocytogenes Meningitis Resulting in Hydrocephalus and Severe Neurological Sequelae in a Previously Healthy Immunocompetent Man with Penicillin Allergy

    DEFF Research Database (Denmark)

    Gaini, Shahin; Karlsen, Gunn Hege; Nandy, Anirban

    2015-01-01

    for bacteria, no bacterial growth, and negative polymerase chain reaction for bacterial DNA. The patient developed hydrocephalus on a second CT scan of the brain on the 5th day of admission. An external ventricular catheter was inserted and Listeria monocytogenes grew in the cerebrospinal fluid from...

  1. The Impact of Positive and Negative Ecstasy-Related Information on Ecstasy Use among College Students: Results of a Longitudinal Study

    Science.gov (United States)

    Vincent, Kathryn B.; Caldeira, Kimberly M.; O'Grady, Kevin E.; Wish, Eric D.; Arria, Amelia M.

    2010-01-01

    Aims: To: (1) estimate the proportion of students exposed to specific types of information regarding the positive and negative effects of ecstasy, (2) test models that quantified the relationship between exposure to these messages and subsequent ecstasy use, controlling for peer drug use and sensation-seeking. Methods: As part of the College Life…

  2. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    Science.gov (United States)

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  3. Negative anisotropic magnetoresistance resulting from minority spin transport in NixFe4-xN (x = 1 and 3) epitaxial films

    Science.gov (United States)

    Takata, Fumiya; Kabara, Kazuki; Ito, Keita; Tsunoda, Masakiyo; Suemasu, Takashi

    2017-01-01

    We grew 50 nm-thick NixFe4-xN (x = 1 and 3) epitaxial films on a SrTiO3(001) single-crystal substrate by molecular beam epitaxy and measured their anisotropic magnetoresistance (AMR) ratios rAMR in the temperature range of 5-300 K with current directions set along either NixFe4-xN [100] or [110]. A negative rAMR was obtained up to 200 K or higher. Their magnitude | rAMR | increased with decreasing temperature. From the negative AMR effect and the negative spin-polarization of density of states for NixFe4-xN at the Fermi level, it can be stated that the minority spin transport is dominant in NixFe4-xN, similar to Fe4N and Co3FeN. The rAMR depends on the current direction that arises from the current direction dependence of s-d scattering. In the case of Ni3FeN, the rAMR decreased to nearly zero at 260 K. This temperature agreed well with the Curie temperature determined from the temperature dependence of magnetization. The AMR curves were reproduced well by using both cos2ϕ and cos4ϕ components below 100 K, whereas a cos2ϕ component was enough to fit those obtained above 100 K. It is assumed that the tetragonal crystal field was enhanced at low temperatures (<100 K) similar to Fe4N (<50 K).

  4. Comparative in vitro activity of carbapenems against major Gram-negative pathogens: results of Asia-Pacific surveillance from the COMPACT II study.

    Science.gov (United States)

    Kiratisin, Pattarachai; Chongthaleong, Anan; Tan, Thean Yen; Lagamayo, Evelina; Roberts, Sally; Garcia, Jemelyn; Davies, Todd

    2012-04-01

    Resistance rates amongst Gram-negative pathogens are increasing in the Asia-Pacific region. The Comparative Activity of Carbapenem Testing (COMPACT) II study surveyed the carbapenem susceptibility and minimum inhibitory concentrations (MICs) of doripenem, imipenem and meropenem against 1260 major Gram-negative pathogens isolated from hospitalised patients at 20 centres in five Asia-Pacific countries (New Zealand, the Philippines, Singapore, Thailand and Vietnam) during 2010. Pseudomonas aeruginosa (n=625), Enterobacteriaceae (n=500), and other Gram-negative pathogens including Acinetobacter baumannii (n=135) were collected from patients with bloodstream infection (32.2%), nosocomial pneumonia including ventilator-associated pneumonia (58.1%), and complicated intra-abdominal infection (9.7%), with 36.7% being isolated from patients in an Intensive Care Unit. As high as 29.8% of P. aeruginosa and 73.0% of A. baumannii isolates were not susceptible to at least a carbapenem, whereas the majority of Enterobacteriaceae (97.2%) were susceptible to all carbapenems. Respective MIC(50)/MIC(90) values (MICs for 50% and 90% of the organisms, respectively) of doripenem, imipenem and meropenem were: 0.38/8, 1.5/32 and 0.38/16 mg/L for P. aeruginosa; 0.023/0.094, 0.25/0.5 and 0.032/0.094 mg/L for Enterobacteriaceae; and 32/64, 32/128 and 32/64 mg/L for A. baumannii. Doripenem and meropenem had comparable activity against P. aeruginosa, both being more active than imipenem. All carbapenems were highly potent against Enterobacteriaceae, although imipenem demonstrated higher MIC values than doripenem and meropenem. The three carbapenems showed less activity against A. baumannii. The high prevalence of carbapenem resistance amongst important nosocomial pathogens (P. aeruginosa and A. baumannii) warrants rigorous infection control measures and appropriate antimicrobial use in the Asia-Pacific region.

  5. Negative Numbers

    Science.gov (United States)

    Galbraith, Mary J.

    1974-01-01

    Examination of models for representing integers demonstrates that formal operational thought is required for establishing the operations on integers. Advocated is the use of many models for introducing negative numbers but, apart from addition, it is recommended that operations on integers be delayed until the formal operations stage. (JP)

  6. 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…

  7. D471G Mutation in LCMV-NP Affects Its Ability to Self-associate and Results in a Dominant Negative Effect in Viral RNA Synthesis

    Directory of Open Access Journals (Sweden)

    Luis Martínez-Sobrido

    2012-10-01

    Full Text Available Arenaviruses merit significant interest because several family members are etiological agents of severe hemorrhagic fevers, representing a major burden to public health. Currently, there are no FDA-licensed vaccines against arenaviruses and the only available antiviral therapy is limited to the use of ribavirin that is partially effective. Arenavirus nucleoprotein (NP is found associated with the genomic RNA forming the viral ribonucleoproteins (vRNPs that together with the polymerase (L direct viral replication and transcription. Virion formation requires the recruitment of vRNPs into budding sites, a process in which the arenavirus matrix-like protein (Z plays a major role. Therefore, proper NP-NP and NP-Z interactions are required for the generation of infectious progeny. In this work we demonstrate the role of the amino acid residue D471 in the self-association of lymphocytic choriomeningitis virus nucleoprotein (LCMV-NP. Amino acid substitutions at this position abrogate NP oligomerization, affecting its ability to mediate replication and transcription of a minigenome reporter plasmid. However, its ability to interact with the Z protein, counteract the cellular interferon response and bind to dsRNA analogs was retained. Additionally, we also document the dominant negative effect of D471G mutation on viral infection, suggesting that NP self-association is an excellent target for the development of new antivirals against arenaviruses.

  8. Disruption of the protein kinase N gene of Drosophila melanogaster Results in the Recessive delorean Allele (pkndln ) With a Negative Impact on Wing Morphogenesis

    OpenAIRE

    Sass, Georgette L.; Ostrow, Bruce D.

    2014-01-01

    We describe the delorean mutation of the Drosophila melanogaster protein kinase N gene (pkndln ) with defects in wing morphology. Flies homozygous for the recessive pkndln allele have a composite wing phenotype that exhibits changes in relative position and shape of the wing blade as well as loss of specific vein and bristle structures. The pkndln allele is the result of a P-element insertion in the first intron of the pkn locus, and the delorean wing phenotype is contingent upon the interact...

  9. Negative refractive index with negative absorption

    CERN Document Server

    Wuestner, Sebastian; Tsakmakidis, Kosmas L; Hamm, Joachim M; Hess, Ortwin

    2010-01-01

    On the basis of a full-vectorial three-dimensional Maxwell-Bloch approach we investigate the possibility of using gain to overcome losses in a negative refractive index fishnet metamaterial. We show that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the non-bianisotropic metamaterial becomes amplifying. In that region both the real and the imaginary part of the effective refractive index become simultaneously negative and the figure-of-merit diverges at two distinct frequency points.

  10. Disruption of the protein kinase N gene of drosophila melanogaster results in the recessive delorean allele (pkndln) with a negative impact on wing morphogenesis.

    Science.gov (United States)

    Sass, Georgette L; Ostrow, Bruce D

    2014-04-16

    We describe the delorean mutation of the Drosophila melanogaster protein kinase N gene (pkn(dln)) with defects in wing morphology. Flies homozygous for the recessive pkn(dln) allele have a composite wing phenotype that exhibits changes in relative position and shape of the wing blade as well as loss of specific vein and bristle structures. The pkn(dln) allele is the result of a P-element insertion in the first intron of the pkn locus, and the delorean wing phenotype is contingent upon the interaction of insertion-bearing alleles in trans. The presence of the insertion results in production of a novel transcript that initiates from within the 3' end of the P-element. The delorean-specific transcript is predicted to produce a wild-type PKN protein. The delorean phenotype is not the result of a reduction in pkn expression, as it could not be recreated using a variety of wing-specific drivers of pkn-RNAi expression. Rather, it is the presence of the delorean-specific transcript that correlates with the mutant phenotype. We consider the delorean wing phenotype to be due to a pairing-dependent, recessive mutation that behaves as a dosage-sensitive, gain of function. Our analysis of genetic interactions with basket and nemo reflects an involvement of pkn and Jun-terminal kinase signaling in common processes during wing differentiation and places PKN as a potential effector of Rho1's involvement in the Jun-terminal kinase pathway. The delorean phenotype, with its associated defects in wing morphology, provides evidence of a role for PKN in adult morphogenetic processes.

  11. VTD-melphalan is well tolerated and results in very high rates of stringent CR and MRD-negative status in multiple myeloma.

    Science.gov (United States)

    Nadiminti, Kalyan; Singh Abbi, Kamal Kant; Mott, Sarah L; Dozeman, Lindsay; Tricot, Annick; Schultz, Allyson; Behrends, Sonya; Zhan, Fenghuang; Tricot, Guido

    2017-01-01

    The addition of cytotoxic drugs to high-dose melphalan as a preparative regimen for autologous stem cell transplantation in multiple myeloma has not resulted in superior activity. Although novel agents have significantly improved outcome in multiple myeloma, their role in preparative regimens remains largely unknown. We have evaluated the toxicity and efficacy of combining bortezomib, thalidomide, and dexamethasone with high-dose melphalan. An institutional review board-approved retrospective analysis was performed on 100 consecutive patients receiving 153 transplants; 53 had tandem transplants; 64 patients received early transplants; and 36 had salvage transplantation. Endpoints were treatment-related toxicity and mortality, and quality of response post-transplantation with assessment of stringent complete remission (sCR) and minimal residual disease (MRD) status. Median age was 61 years, and median follow-up was 16.2 months. At 6 months, sCR was attained in 56% of patients and CR in 20%. An MRD status, assessed by sensitive (10(-4)) multiparameter flow cytometry, was achieved in 85%. The 100-day mortality rate was 2.6% (4/153); 1.8% for early transplants and 4.5% for salvage transplants. Grade 3-5 non-hematologic toxicities were mainly related to metabolism/nutrition; gastrointestinal and infectious problems. Median time to absolute neutrophil count of >500/µL was 12 days for both early and salvage transplantations. No significant differences in quality of response were observed between early and salvage transplantation or between single and tandem autologous stem cell transplantation. Since both sCR and MRD are excellent early surrogate markers for progression-free and overall survival, this regimen will likely be superior to melphalan alone, but it needs to be formally assessed in a randomized study.

  12. Effectiveness of Alpha Biofeedback Therapy: Negative Results.

    Science.gov (United States)

    Watson, Charles G.; Herder, Joseph

    1980-01-01

    Assessed the utility of alpha biofeedback training in the treatment of patients (N=66). Biofeedback and placebo biofeedback groups were given alpha or mock-alpha training sessions. Improvement on 54 variables was compared to that of no-treatment controls. Only a chance number of significant changes appeared among the groups. (Author)

  13. Rh(D)阴性献血者不规则抗体检测的结果分析%Analysis the result of irregular antibody test in Rh (D) negative donors

    Institute of Scientific and Technical Information of China (English)

    李健; 周英; 吕文彬; 陈雪; 迭敏; 龚希

    2012-01-01

    目的 分析Rh(D)阴性献血者不规则抗体检测的结果,探讨在献血者血液Rh(D)阴性确认试验时,进行不规则抗体检测的必要性.方法 用间接抗人球蛋白法进行Rh(D)阴性确认试验及抗体筛选试验、抗体鉴定试验,盐水法进行Rh表现型的检测.结果 1205份Rh(D)阴性献血员标本中,抗体筛选试验阳性的标本有20份,经过抗体鉴定,其中抗-D 10份,抗-M 6份,非特异性抗体2份,抗-Lea 1份,冷自身抗体1份.结论 Rh(D)阴性献血者抗体筛选阳性率高达1.66%,较以往报道的正常人群抗体筛选阳性率高.在临床供血上,其高检出率对临床用血安全有较为重要的意义,对Rh(D)阴性献血者更应该进行不规则抗体检测.%Objective To analyze the result of irregular antibody test in Rh (D) negatie donors, discuss in the necessity of irregular antibody test in Rh (D) negative confirmation experiment among the blood testing with Rh ( D) negative donors. Methods Rh (D) negative confirmation experiment antibody screening and antibody Identification test using indirect antiglobulin test(IAT) , The Rh phenotype were determined by saline method. Results among 120S samples of Rh (D) negative donors, 20 samples antibody screening test is positive. And after antibody Identification test, Among them 10 samples were anti- 0 , 6 samples were anti- M, 2 samples were Nonspecific antibody, 1 sample was anti- Le,l sample was cold antibody. Conclusion The positive rate of Antibody screening in Rh ( D) negative donors is 1. 66% . It is greater than Previous reports of the normal population positive antibody screening. The higher positive rate of Antibody screening has Important clinical significance in blood supply, therefore Rh ( D) negative donors more should do irregular antibody test.

  14. 杭州地区体检人群乙型肝炎病毒标志物阴性结果分析%Analysis of negative results of hepatitis B virus markers in healthy population in Hangzhou district

    Institute of Scientific and Technical Information of China (English)

    钟毓红; 戴宇; 张松照

    2015-01-01

    目的:分析2014年杭州地区体检人群乙型肝炎病毒血清学五项标志物(HBV‐M )全阴模式的分布特征,为预防和控制HBV‐M阴性人群感染乙型肝炎病毒(HBV )提供对策。方法采用 ELISA 对体检人群的血液标本进行 HBV‐M (HBsAg、HBsAb、HBeAg、HBeAb和HBcAb)检测。对保存的300例 HBV‐M阴性标本,分别使用化学发光免疫分析法检测 HBsAg、HB‐sAb和PROCLEIX ULTRIO棆 Assay检测HBV‐DNA ,对 HBV‐DNA反应性标本进行病毒载量测定。结果在检测的9143例体检者的标本中,2213例标本为 HBV‐M阴性,阴性率为24.20%;男女 HBV‐M 阴性率比值为1∶1.21。使用化学发光免疫分析法和PROCLEIX ULTRIO棆 Assay分别检测出1例低浓度的HBsAg标本(HBsAb及 HBV DNA均无反应性),4例低浓度的HBsAb标本(HBsAg及 HBV DNA均无反应性),2例 HBV‐DNA反应性标本(HBV‐M 阴性)。其中1例 HBV‐DNA反应性标本定量检测为560 IU/mL。结论杭州地区ELISA HBV‐M 阴性的体检人群中,少数人可检出低浓度的 HBsAg或 HBsAb或HBV DNA。针对ELISA HBV‐M阴性人群,建议接种乙肝疫苗前进行HBV‐M和HBV‐DNA定量检测,以确定是否需要接种乙肝疫苗及接种乙肝疫苗的方案。%Objective To analyse the distribution characteristics of negative pattern of hepatitis B virus Markers (HBV‐M ) in healthy population in Hangzhou district in 2014 ,and provide strategy for the prevention and control of HBV infection in HBV‐M negative population .Methods The HBV‐M (HBsAg ,HBsAb ,HBeAg ,HBeAb and HBcAb) in blood specimens of health examina‐tion population were tested by using ELISA .For 300 cases preserved HBV‐M negative specimens ,HBsAg and HBsAb were detec‐ted by using chemiluminescence immunoassay and HBV‐DNA was detected by using PROCLEIX ULTRIO® Assay .The viral load of HBV‐DNA reactive sample was quantitatively determined .Results Among 9 143

  15. Differential sensitivity of aerobic gram-positive and gram-negative microorganisms to 2,4,6-trinitrotoluene (TNT) leads to dissimilar growth and TNT transformation: Results of soil and pure culture studies

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, M.E.; Manning, J.F. Jr.

    1996-07-30

    The effects of 2,4,6-trinitrotoluene (TNT) on indigenous soil populations and pure bacterial cultures were examined. The number of colony-forming units (CFU) appearing when TNT-contaminated soil was spread on 0.3% molasses plates decreased by 50% when the agar was amended with 67 {mu}g TNT mL{sup -1}, whereas a 99% reduction was observed when uncontaminated soil was plated. Furthermore, TNT-contaminated soil harbored a greater number of organisms able to grow on plates amended with greater than 10 {mu}g TNT mL{sup -1}. The percentage of gram-positive isolates was markedly less in TNT-contaminated soil (7%; 2 of 30) than in uncontaminated soil (61%; 20 of 33). Pseudomonas aeruginosa, Pseudomonas corrugate, Pseudomonasfluorescens and Alcaligenes xylosoxidans made up the majority of the gram-negative isolates from TNT-contaminated soil. Gram-positive isolates from both soils demonstrated marked growth inhibition when greater than 8-16 {mu}g TNT mL{sup -1} was present in the culture media. Most pure cultures of known aerobic gram-negative organisms readily degraded TNT and evidenced net consumption of reduced metabolites. However, pure cultures of aerobic gram-positive bacteria were sensitive to relatively low concentrations of TNT as indicated by the 50% reduction in growth and TNT transformation which was observed at approximately 10 {mu}g TNT mL{sup -1}. Most non-sporeforming gram-positive organisms incubated in molasses media amended with 80 {mu}g TNT mL{sup -1} or greater became unculturable, whereas all strains tested remained culturable when incubated in mineral media amended with 98 {mu}g TNT mL{sup -1}, indicating that TNT sensitivity is likely linked to cell growth. These results indicate that gram-negative organisms are most likely responsible for any TNT transformation in contaminated soil, due to their relative insensitivity to high TNT concentrations and their ability to transform TNT.

  16. Wie häufig und belastend sind negative Erfahrungen im Medizinstudium? – Ergebnisse einer Online-Befragung von Medizinstudierenden [Frequency and perceived severity of negative experiences during medical education in Germany – Results of an online-survery of medical students

    Directory of Open Access Journals (Sweden)

    Gágyor, Ildikó

    2012-08-01

    Full Text Available [english] Aims: Negative experiences during the course of medical education have been reported in many countries, but little is known about the perceived severity of these experiences. We studied for the first time how often students at a medical university in Germany have had negative experiences, and how severe they perceive these to be.Method: We asked medical students in an online survey whether they felt adequately appreciated, had experienced peer rivalry, verbal abuse by their mentors, physical abuse or mistreatment, sexual harassment, racial or ethnic discrimination, or any other kind of mistreatment.Results: Of 391 students, 56% stated that they felt insufficiently appreciated, 51% had experienced rivalry, and 34% had suffered verbal abuse. Fifty-nine percent of the students felt highly aggrieved because of verbal abuse, while 46% were aggrieved by the ongoing rivalry and 32% by the lack of appreciation. Significantly fewer students felt upset because they were passed over or ignored (21%. Generally, female students felt more often aggrieved by these negative experiences than their male colleagues.Conclusion: Of the possible negative experiences, the less prominent ones such as lack of appreciation or verbal abuse are not only frequent, they are also perceived as very upsetting. Medical teachers should reflect this more in their day-to-day dealings with students and aim to improve on their contact with the students accordingly.[german] Zielsetzung: Negative Erfahrungen im Medizinstudium sind bereits in vielen Ländern untersucht worden. Wenig ist jedoch darüber bekannt, welche Erfahrungen als belastend empfunden werden. In dieser Studie sollten – zum ersten Mal in Deutschland – Studierende nach der Häufigkeit negativer Erfahrungen und der daraus resultierenden Belastung befragt werden.Methodik: Medizinstudierende wurden online zu Wertschätzung, Konkurrenz, verbal unangemessener Behandlung, körperlicher Maßregelung, sexueller

  17. The negation bias: when negations signal stereotypic expectancies.

    Science.gov (United States)

    Beukeboom, Camiel J; Finkenauer, Catrin; Wigboldus, Daniël H J

    2010-12-01

    Research on linguistic biases shows that stereotypic expectancies are implicitly reflected in language and are thereby subtly communicated to message recipients. We examined whether these findings extend to the use of negations (e.g., not smart instead of stupid). We hypothesized that people use more negations in descriptions of stereotype-inconsistent behavior than in descriptions of stereotype-consistent behavior. In 3 studies, participants either judged the applicability of experimentally controlled person descriptions or spontaneously produced person descriptions themselves. Results provided support for this hypothesis. Moreover, a 4th study demonstrated that negations have communicative consequences. When a target person's behavior was described with negations, message recipients inferred that this behavior was an exception to the rule and that it was more likely caused by situational circumstances than by dispositional factors. These findings indicate that by using negations people implicitly communicate stereotypic expectancies and that negations play a subtle but powerful role in stereotype maintenance.

  18. On Multiplying Negative Numbers.

    Science.gov (United States)

    Crowley, Mary L.; Dunn, Kenneth A.

    1985-01-01

    Comments on the history of negative numbers, some methods that can be used to introduce the multiplication of negative numbers to students, and an explanation of why the product of two negative numbers is a positive number are included. (MNS)

  19. Brain representations of negative numbers.

    Science.gov (United States)

    Parnes, Michael; Berger, Andrea; Tzelgov, Joseph

    2012-12-01

    Participants performed a physical comparison task of pairs of positive and pairs of negative one-digit numbers while their electrophysiological brain activity was measured. The numerical value of the presented digits was either congruent or incongruent with the physical size of the digits. Analysis has shown that the earliest event-related potential (ERP) difference between positive and negative numbers was found in the P300 ERP component peak, where there was an inverse effect of congruity in the negative pairs, compared with the positive ones. This pattern of results supports the idea that natural numbers serve as primitives of the human cognitive system, whereas negative numbers are apparently generated if needed.

  20. 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.

  1. Negative hydrogen ion production mechanisms

    Science.gov (United States)

    Bacal, M.; Wada, M.

    2015-06-01

    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.

  2. Efficacy and safety of adding an agent to bevacizumab/taxane regimens for the first-line treatment of Her2-negative patients with locally recurrent or metastatic breast cancer: results from seven randomized controlled trials

    Science.gov (United States)

    Liu, Xiaoqun; Liu, Xiangdong; Qiao, Tiankui; Chen, Wei; Yuan, Sujuan

    2016-01-01

    Background The combined therapy of bevacizumab (BEV) with taxane (paclitaxel or docetaxel) has shown an improvement on progression-free survival (PFS) and objective remission in Her2-negative patients with locally recurrent or metastatic breast cancer (LR/MBC). However, there was no benefit in overall survival (OS). The aim of this study was to evaluate the efficacy and safety of adding an agent to the BEV/taxane regimens for the treatment of Her2-negative patients with LR/MBC in a first-line setting. Materials and methods We searched PubMed, Web of Science, EMBASE, EBSCO, and the Cochrane Library databases for eligible trials. A meta-analysis was performed using Review Manager 5.0 freeware package. We calculated the hazard ratio (HR) for PFS and OS. The odds ratio (OR) was used to calculate objective response rate (ORR) and grade 3/4 drug-related adverse events. The heterogeneity of study outcomes was calculated by the χ2 test or I2 statistics. Results A total of 1,124 patients from seven randomized controlled trials were analyzed. Our meta-analysis showed that the ORR was significantly improved in the BEV/taxane-based triplet group when compared with the BEV/taxane-based doublet group (OR =1.31, 95% confidence interval [CI]: 1.03–1.67, P=0.03). A subset analysis showed that a similar result was achieved in the triplet group in which a cytotoxic agent was added (OR =1.46, 95% CI: 1.09–1.95, P=0.01). However, the PFS and OS had no statistically significant differences between the two groups (HR =0.87, 95% CI: 0.68–1.13, P=0.31; HR =0.98, 95% CI: 0.82–1.16, P=0.78, respectively). Regarding safety, thromboembolic events, fatigue, and diarrhea (all $grade 3) were more frequently observed in the BEV/taxane-based triplet group (OR =3.8, 95% CI: 1.86–7.79, P=0.0003; OR =1.55, 95% CI: 1.05–2.27, P=0.03; OR =2.1, 95% CI: 1.29–3.41, P=0.003, respectively). Other toxic effects had no statistically significant differences between the two groups. Conclusion Our

  3. Negative Emissions Technology

    Science.gov (United States)

    Day, Danny

    2006-04-01

    Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

  4. Compound negative binomial distribution with negative multinomial summands

    Science.gov (United States)

    Jordanova, Pavlina K.; Petkova, Monika P.; Stehlík, Milan

    2016-12-01

    The class of Negative Binomial distributions seems to be introduced by Greenwood and Yule in 1920. Due to its wide spread application, investigations of distributions, closely related with it will be always contemporary. Bates, Neyman and Wishart introduce Negative Multinomial distribution. They reach it considering the mixture of independent Poisson distributed random variables with one and the same Gamma mixing variable. This paper investigates a particular case of multivariate compound distribution with one and the same compounding variable. In our case it is Negative Binomial or Sifted Negative Binomial. The summands with equal indexes in different coordinates are Negative Multinomially distributed. In case without shifting, considered as a mixture, the resulting distribution coincides with Mixed Negative Multinomial distribution with scale changed Negative Binomially distributed first parameter. We prove prove that it is Multivariate Power Series Distributed and find explicit form of its parameters. When the summands are geometrically distributed this distribution is stochastically equivalent to a product of independent Bernoulli random variable and appropriate multivariate Geometrically distributed random vector. We show that Compound Shifted Negative Binomial Distribution with Geometric Summands is a particular case of Negative Multinomial distribution with new parameters.

  5. Negating the Verum

    DEFF Research Database (Denmark)

    Ørsnes, Bjarne

    2012-01-01

    In Danish the base position of the negation (and negated quantifier phrases) is between the subject and the finite verb in embedded clauses. However, in embedded clauses introduced by a non-veridical complementizer such as hvis ‘if’ or om ‘whether’, the negation can also appear between the comple......In Danish the base position of the negation (and negated quantifier phrases) is between the subject and the finite verb in embedded clauses. However, in embedded clauses introduced by a non-veridical complementizer such as hvis ‘if’ or om ‘whether’, the negation can also appear between...

  6. Negation in English

    Institute of Scientific and Technical Information of China (English)

    宋炳

    2016-01-01

    Every language has its own unique ways of negation and English is no exception. More importance should be attached to when a negative English sentence is translated into its Chinese equivalent. Negation in English can be realized in many differ-ent ways. In the first place, the different types of negation in English will be analyzed. In addition, the affixes and lexicons used to denote negation will be investigated. The last part is mainly concerning the idioms and other expressions which denote nega-tive meanings. In order to make the views much more clearly, some Chinese equivalents of the English sentences will be offered here.

  7. Analysis of Negative Correlation Learning

    Institute of Scientific and Technical Information of China (English)

    Liu Yong; Zou Xiu-fen

    2003-01-01

    This paper describes negative correlation learning for designing neural network ensembles. Negative correlation learning has been firstly analysed in terms of minimising mutual information on a regression task. By ninimising the mutual information between variables extracted by two neural networks, they are forced to convey different information about some features of their input. Based on the decision boundaries and correct response sets, negative correlation learning has been further studied on two pattern classification problems. The purpose of examining the decision boundaries and the correct response sets is not only to illustrate the learning behavior of negative correlation learning, but also to cast light on how to design more effective neural network ensembles. The experimental results showed the decision boundary of the trained neural network ensemble by negative correlation learning is almost as good as the optimum decision boundary.

  8. Physics of negative absolute temperatures

    Science.gov (United States)

    Abraham, Eitan; Penrose, Oliver

    2017-01-01

    Negative absolute temperatures were introduced into experimental physics by Purcell and Pound, who successfully applied this concept to nuclear spins; nevertheless, the concept has proved controversial: a recent article aroused considerable interest by its claim, based on a classical entropy formula (the "volume entropy") due to Gibbs, that negative temperatures violated basic principles of statistical thermodynamics. Here we give a thermodynamic analysis that confirms the negative-temperature interpretation of the Purcell-Pound experiments. We also examine the principal arguments that have been advanced against the negative temperature concept; we find that these arguments are not logically compelling, and moreover that the underlying "volume" entropy formula leads to predictions inconsistent with existing experimental results on nuclear spins. We conclude that, despite the counterarguments, negative absolute temperatures make good theoretical sense and did occur in the experiments designed to produce them.

  9. C1Q Assay Results in Complement-Dependent Cytotoxicity Crossmatch Negative Renal Transplant Candidates with Donor-Specific Antibodies: High Specificity but Low Sensitivity When Predicting Flow Crossmatch

    Directory of Open Access Journals (Sweden)

    José M. Arreola-Guerra

    2016-01-01

    Full Text Available The aim of the present study was to describe the association of positive flow cross match (FXM and C1q-SAB. Methods. In this observational, cross-sectional, and comparative study, patients included had negative AHG-CDC-XM and donor specific antibodies (DSA and were tested with FXM. All pretransplant sera were tested with C1q-SAB assay. Results. A total of 50 donor/recipient evaluations were conducted; half of them had at least one C1q+ Ab (n=26, 52%. Ten patients (20.0% had DSA C1q+ Ab. Twenty-five (50% FXMs were positive. Factors associated with a positive FXM were the presence of C1q+ Ab (DSA C1q+ Ab: OR 27, 2.80–259.56, P=0.004, and no DSA C1q+ Ab: OR 5, 1.27–19.68, P=0.021 and the DSA LABScreen-SAB MFI (OR 1.26, 95% CI 1.06–1.49, P=0.007. The cutoff point of immunodominant LABScreen SAB DSA-MFI with the greatest sensitivity and specificity to predict FXM was 2,300 (sensitivity: 72% and specificity: 75%. For FXM prediction, DSA C1q+ Ab was the most specific (95.8%, 85–100 and the combination of DSA-MFI > 2,300 and C1q+ Ab was the most sensitive (92.0%, 79.3–100. Conclusions. C1q+ Ab and LABScreen SAB DSA-MFI were significantly associated with FXM. DSA C1q+ Ab was highly specific but with low sensitivity.

  10. 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…

  11. Personality, Negativity, and Political Participation

    Directory of Open Access Journals (Sweden)

    Aaron C. Weinschenk

    2014-08-01

    Full Text Available Scholars have recently started to integrate personality traits into models of political participation. In this paper, we present the results of a survey experiment (N = 724 designed to test whether negative political messages differentially impact people with different personality traits. We found evidence that individuals with high scores on agreeableness were less likely, and individuals with high scores on extraversion were more likely, to report intending to participate in politics than their counterparts after being exposed to negative political messages. Agreeableness and extraversion also interacted with negative messages to influence specific intentions to make a political donation, attend a meeting, rally, or event, and volunteer for a political campaign. We also found suggestive evidence that agreeableness interacted with negativity to influence turnout intentions. The results of this study have important implications for the study of political engagement, the ways in which people interact with political information, and the practice of democratic politics.

  12. 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.

  13. Broncoscopia no diagnóstico de tuberculose pulmonar em pacientes com baciloscopia de escarro negativa Bronchoscopy for the diagnosis of pulmonary tuberculosis in patients with negative sputum smear microscopy results

    Directory of Open Access Journals (Sweden)

    Márcia Jacomelli

    2012-04-01

    Full Text Available OBJETIVO: Avaliar a acurácia diagnóstica da broncoscopia em pacientes com suspeita clínica ou radiológica de tuberculose, com baciloscopia negativa ou incapazes de produzir escarro. MÉTODOS: Estudo transversal prospectivo de 286 pacientes com suspeita clínica/radiológica de tuberculose pulmonar e submetidos à broncoscopia - LBA e biópsia transbrônquica (BTB. As amostras de LBA foram testadas por pesquisas diretas e culturas de BAAR e de fungos, e as de BTB por exame histopatológico. RESULTADOS: Dos 286 pacientes estudados, a broncoscopia contribuiu para o diagnóstico em 225 (79%: tuberculose pulmonar em 127 (44%; inflamações crônicas inespecíficas em 51 (18%; pneumocistose, infecções fúngicas ou nocardiose em 20 (7%; bronquiolite obliterante com pneumonia em organização, alveolites ou pneumoconioses em 14 (5%; neoplasias pulmonares ou metastáticas em 7 (2%; e micobacterioses não tuberculosas em 6 (2%. Para o diagnóstico de tuberculose, o LBA mostrou sensibilidade e especificidade de 60% e 100% respectivamente, havendo um aumento importante da sensibilidade quando associado à biópsia (84% e à baciloscopia após a broncoscopia (94%. Complicações controláveis decorrentes do procedimento ocorreram em 5,6% dos casos. CONCLUSÕES: A broncoscopia representa um método diagnóstico confiável para pacientes com tuberculose pulmonar, apresentando baixos índices de complicações. A associação de biópsia transbrônquica ao lavado broncoalveolar elevou a sensibilidade diagnóstica do método e permitiu o diagnóstico diferencial com outras doenças.OBJECTIVE: To evaluate the diagnostic accuracy of bronchoscopy in patients with clinical or radiological suspicion of tuberculosis who were unable to produce sputum or with negative sputum smear microscopy results. METHODS: A prospective cross-sectional study involving 286 patients under clinical or radiological suspicion of having pulmonary tuberculosis and submitted to

  14. Differential impact of parental region of birth on negative parenting behavior and its effects on child mental health: Results from a large sample of 6 to 11 year old school children in France

    OpenAIRE

    Kovess-Masfety, Viviane; Husky, Mathilde; Pitrou, Isabelle; Fermanian, Christophe; Shojaei, Taraneh; Chee, Christine Chan; Siddiqi, Arjumand; Beiser, Morton

    2016-01-01

    Background In France, one in 10 residents has immigrated mainly from North Africa, West Africa or the Caribbean including the French West Indies. However little is known about how parents from these regions behave when they migrate to countries that have different cultural norms. It is therefore important to determine how ethno-cultural background affects parental behavior and subsequent child mental health in the context of immigration. The objectives are: 1) to compare negative parenting be...

  15. Primitive Virtual Negative Charge

    CERN Document Server

    Kim, Kiyoung

    2008-01-01

    Physical fields, such as gravity and electromagnetic field, are interpreted as results from rearrangement of vacuum particles to get the equilibrium of net charge density and net mass density in 4-dimensional complex space. Then, both fields should interact to each other in that physical interaction is considered as a field-to-field interaction. Hence, Mass-Charge interaction is introduced with primitive-virtual negative charge defined for the mass. With the concept of Mass-Charge interaction electric equilibrium of the earth is discussed, especially about the electric field and magnetic field of the earth. For unsettled phenomena related with the earth's gravity, such as antigravity phenomenon, gravity anomalies during the solar eclipses, the connection between geomagnetic storms and earthquakes, etc., possible explanations are discussed.

  16. Piezoelectric enhancement under negative pressure

    Science.gov (United States)

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-07-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

  17. Negative numbers in simple arithmetic.

    Science.gov (United States)

    Das, Runa; LeFevre, Jo-Anne; Penner-Wilger, Marcie

    2010-10-01

    Are negative numbers processed differently from positive numbers in arithmetic problems? In two experiments, adults (N = 66) solved standard addition and subtraction problems such as 3 + 4 and 7 - 4 and recasted versions that included explicit negative signs-that is, 3 - (-4), 7 + (-4), and (-4) + 7. Solution times on the recasted problems were slower than those on standard problems, but the effect was much larger for addition than subtraction. The negative sign may prime subtraction in both kinds of recasted problem. Problem size effects were the same or smaller in recasted than in standard problems, suggesting that the recasted formats did not interfere with mental calculation. These results suggest that the underlying conceptual structure of the problem (i.e., addition vs. subtraction) is more important for solution processes than the presence of negative numbers.

  18. The Analysis of Negative

    Institute of Scientific and Technical Information of China (English)

    辛琨

    2009-01-01

    @@ Chapter 1 The Meaning of Negation Negation,in our daily life,is very commonly used.When you deny something,you use it;when you refuse something,you use it too.And the most common negatiom"no"and"not"are used by US every day.

  19. Negative creep in nickel base superalloys

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter; Hald, John

    2004-01-01

    Negative creep describes the time dependent contraction of a material as opposed to the elongation seen for a material experiencing normal creep behavior. Negative creep occurs because of solid state transformations that results in lattice contractions. For most applications negative creep will h...

  20. Toward a Negative Anthropology

    OpenAIRE

    Johannssen, Dennis

    2014-01-01

    Can philosophy say what man is? What is gained or lost by making theoretical assumptions about the human being? This essay examines the “negative anthropology” of the early Frankfurt School by asking how Max Horkheimer, Theodor W. Adorno and Ulrich Sonnemann engage with the question “What is man?” Negative anthropology turns out to be more than the critique of philosophical anthropology: By understanding the human being as the ensemble of what it is not, negative anthropology avoids the predi...

  1. Negative thermal expansion

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, G D [Departamento de QuImica, Universidad Nacional de la Patagonia SJB, Ciudad Universitaria, 9000 Comodoro Rivadavia (Argentina); Bruno, J A O [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de QuImica Inorganica, AnalItica y QuImica FIsica, Pabellon 2, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Barron, T H K [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom); Allan, N L [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom)

    2005-02-02

    There has been substantial renewed interest in negative thermal expansion following the discovery that cubic ZrW{sub 2}O{sub 8} contracts over a temperature range in excess of 1000 K. Substances of many different kinds show negative thermal expansion, especially at low temperatures. In this article we review the underlying thermodynamics, emphasizing the roles of thermal stress and elasticity. We also discuss vibrational and non-vibrational mechanisms operating on the atomic scale that are responsible for negative expansion, both isotropic and anisotropic, in a wide range of materials. (topical review)

  2. Holographic Quantum Entanglement Negativity

    CERN Document Server

    Chaturvedi, Pankaj; Sengupta, Gautam

    2016-01-01

    We propose a holographic prescription to compute the entanglement negativity for conformal field theories at finite temperatures which exactly reproduces the entanglement negativity for (1+1)- dimensional conformal field theories at finite temperatures dual to (2+1)- dimensional bulk Euclidean BTZ black holes. We observe that the holographic entanglement negativity captures the distillable pure quantum entanglement and is related to the holographic mutual information. The application of our prescription to higher dimensional conformal field theories at finite temperatures within a $AdS_{d+1}/CFT_{d}$ scenario involving dual bulk $AdS$-Schwarzschild black holes is discussed to elucidate the universality of our conjecture.

  3. Isotropic Single Negative Metamaterials

    Directory of Open Access Journals (Sweden)

    P. Protiva

    2008-09-01

    Full Text Available This paper presents the application of simple, and therefore cheap, planar resonators for building 3D isotropic metamaterials. These resonators are: a broadside-coupled split ring resonator with a magnetic response providing negative permeability; an electric dipole terminated by a loop inductor together with a double H-shaped resonator with an electric response providing negative permittivity. Two kinds of 3D isotropic single negative metamaterials are reported. The first material consists of unit cells in the form of a cube bearing on its faces six equal planar resonators with tetrahedral symmetry. In the second material, the planar resonators boxed into spherical plastic shells and randomly distributed in a hosting material compose a real 3D volumetric metamaterial with an isotropic response. In both cases the metamaterial shows negative permittivity or permeability, according to the type of resonators that are used. The experiments prove the isotropic behavior of the cells and of the metamaterial specimens.

  4. Logo and Negative Numbers.

    Science.gov (United States)

    Strawn, Candace A.

    1998-01-01

    Describes LOGO's turtle graphics capabilities based on a sixth-grade classroom's activities with negative numbers and Logo programming. A sidebar explains LOGO and offers suggestions to teachers for using LOGO effectively. (LRW)

  5. Dose from slow negative muons.

    Science.gov (United States)

    Siiskonen, T

    2008-01-01

    Conversion coefficients from fluence to ambient dose equivalent, from fluence to maximum dose equivalent and quality factors for slow negative muons are examined in detail. Negative muons, when stopped, produce energetic photons, electrons and a variety of high-LET particles. Contribution from each particle type to the dose equivalent is calculated. The results show that for the high-LET particles the details of energy spectra and decay yields are important for accurate dose estimates. For slow negative muons the ambient dose equivalent does not always yield a conservative estimate for the protection quantities. Especially, the skin equivalent dose is strongly underestimated if the radiation-weighting factor of unity for slow muons is used. Comparisons to earlier studies are presented.

  6. Covariant holographic entanglement negativity

    CERN Document Server

    Chaturvedi, Pankaj; Sengupta, Gautam

    2016-01-01

    We conjecture a holographic prescription for the covariant entanglement negativity of $d$-dimensional conformal field theories dual to non static bulk $AdS_{d+1}$ gravitational configurations in the framework of the $AdS/CFT$ correspondence. Application of our conjecture to a $AdS_3/CFT_2$ scenario involving bulk rotating BTZ black holes exactly reproduces the entanglement negativity of the corresponding $(1+1)$ dimensional conformal field theories and precisely captures the distillable quantum entanglement. Interestingly our conjecture for the scenario involving dual bulk extremal rotating BTZ black holes also accurately leads to the entanglement negativity for the chiral half of the corresponding $(1+1)$ dimensional conformal field theory at zero temperature.

  7. Nedtrykt af negative nyheder

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Søberg, Pernille Frantz

    2016-01-01

    I adskillige år er det blevet debatteret, hvorvidt nyhedernes negative fokus har konsekvenser for borgerne, og om det i sid-ste ende får flere til at vende ryggen til nyhederne. Vores viden om effekterne af positive og negative nyheder er dog begrænset, og derfor undersøges det i denne artikel......, hvordan henholdsvis positive og negative tv-nyheder påvirker seernes humør, hukom-melse af information fra indslaget og lyst til at se yderligere tv-nyheder. Det gør vi i et survey-eksperiment (N=204), hvor tre grupper så enten et originalt indslag eller det samme indslag klippet med henholdsvis et...

  8. Negative Probabilities and Contextuality

    CERN Document Server

    de Barros, J Acacio; Oas, Gary

    2015-01-01

    There has been a growing interest, both in physics and psychology, in understanding contextuality in experimentally observed quantities. Different approaches have been proposed to deal with contextual systems, and a promising one is contextuality-by-default, put forth by Dzhafarov and Kujala. The goal of this paper is to present a tutorial on a different approach: negative probabilities. We do so by presenting the overall theory of negative probabilities in a way that is consistent with contextuality-by-default and by examining with this theory some simple examples where contextuality appears, both in physics and psychology.

  9. Polemic and Descriptive Negations

    DEFF Research Database (Denmark)

    Horslund, Camilla Søballe

    2011-01-01

    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...

  10. Depressionens negative spiral

    DEFF Research Database (Denmark)

    Munk, Karen

    2006-01-01

    Artiklen formidler resultater fra en longitudinel undersøgelse af det selvforstærkende, negative samspil imellem udvikling og vedligeholdelse af alderdomsdepression via primære miljøbelastninger og via  den deprimerede ældre som belastning for miljøet, som i sin tur "svarer negativt" på lidelsen og...

  11. The Negative Repetition Effect

    Science.gov (United States)

    Mulligan, Neil W.; Peterson, Daniel J.

    2013-01-01

    A fundamental property of human memory is that repetition enhances memory. Peterson and Mulligan (2012) recently documented a surprising "negative repetition effect," in which participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once. Words within a pair rhymed, and…

  12. Serum testosterone as a biomarker for second prostatic biopsy in men with negative first biopsy for prostatic cancer and PSA>4ng/mL, or with PIN biopsy result

    Science.gov (United States)

    Fiamegos, Alexandros; Varkarakis, John; Kontraros, Michael; Karagiannis, Andreas; Chrisofos, Michael; Barbalias, Dimitrios; Deliveliotis, Charalampos

    2016-01-01

    Abstract Introduction: Data from animal, clinical and prevention studies support the role of androgens in prostate cancer growth, proliferation and progression. Results of serum based epidemiologic studies in humans, however, have been inconclusive. The present study aims to define whether serum testosterone can be used as a predictor of a positive second biopsy in males considered for re-biopsy. Material and Methods: The study included 320 men who underwent a prostatic biopsy in our department from October 2011 until June 2012. Total testosterone, free testosterone, bioavailable testosterone and prostate pathology were evaluated in all cases. Patients undergoing a second biopsy were identified and biopsy results were statistically analyzed. Results: Forty men (12.5%) were assessed with a second biopsy. The diagnosis of the second biopsy was High Grade Intraepithelial Neoplasia in 14 patients (35%) and Prostate Cancer in 12 patients (30%). The comparison of prostatic volume, total testosterone, sex hormone binding globulin, free testosterone, bioavailable testosterone and albumin showed that patients with cancer of the prostate had significantly greater levels of free testosterone (p=0.043) and bioavailable T (p=0.049). Conclusion: In our study, higher free testosterone and bioavailable testosterone levels were associated with a cancer diagnosis at re-biopsy. Our results indicate a possible role for free and bioavailable testosterone in predicting the presence of prostate cancer in patients considered for re-biopsy. PMID:27532110

  13. Exploring Impact: Negative Effects of Social Networks

    OpenAIRE

    Egbert, Henrik; Sedlarski, Teodor

    2011-01-01

    he sociological literature on social networks emphasizes by and large positive network effects. Negative effects of such networks are discussed rather rarely. This paper tackles negative effects by applying economic theory, particularly neoclassical theory, new institutional theory and the results from experimental economics to the concept of social networks. In the paper it is assumed that social networks are exclusive and since exclusiveness affects the allocation of resources, negative ext...

  14. Singularities in universes with negative cosmological constant

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1976-10-01

    It is well known that many universes with negative cosmological constant contain singularities. We shall generalize this result by proving that all closed universes with negative cosmological constant are both future and past timelike geodesically incomplete if the strong energy condition holds. No global causality conditions or restrictions on the initial data are used in the proof. Furthermore, we shall show that all open universes with a Cauchy surface and a negative cosmological constant are singular if the strong energy condition holds. (AIP)

  15. Negative magnetoresistivity in holography

    CERN Document Server

    Sun, Ya-Wen

    2016-01-01

    Negative magnetoresistivity is a special magnetotransport property associated with chiral anomaly in four dimensional chiral anomalous systems, which refers to the transport behavior that the DC longitudinal magnetoresistivity decreases with increasing magnetic field. We calculate the longitudinal magnetoconductivity in the presence of backreactions of the magnetic field to gravity in holographic zero charge and axial charge density systems with and without axial charge dissipation. In the absence of axial charge dissipation, we find that the quantum critical conductivity grows with increasing magnetic field when the backreaction strength is larger than a critical value, in contrast to the monotonically decreasing behavior of quantum critical conductivity in the probe limit. With axial charge dissipation, we find the negative magnetoresistivity behavior. The DC longitudinal magnetoconductivity scales as $B$ in the large magnetic field limit, which deviates from the exact $B^2$ scaling of the probe limit resul...

  16. How do negative emotions impair self-control? A neural model of negative urgency.

    Science.gov (United States)

    Chester, David S; Lynam, Donald R; Milich, Richard; Powell, David K; Andersen, Anders H; DeWall, C Nathan

    2016-05-15

    Self-control often fails when people experience negative emotions. Negative urgency represents the dispositional tendency to experience such self-control failure in response to negative affect. Neither the neural underpinnings of negative urgency nor the more general phenomenon of self-control failure in response to negative emotions are fully understood. Previous theorizing suggests that an insufficient, inhibitory response from the prefrontal cortex may be the culprit behind such self-control failure. However, we entertained an alternative hypothesis: negative emotions lead to self-control failure because they excessively tax inhibitory regions of the prefrontal cortex. Using fMRI, we compared the neural activity of people high in negative urgency with controls on an emotional, inhibitory Go/No-Go task. While experiencing negative (but not positive or neutral) emotions, participants high in negative urgency showed greater recruitment of inhibitory brain regions than controls. Suggesting a compensatory function, inhibitory accuracy among participants high in negative urgency was associated with greater prefrontal recruitment. Greater activity in the anterior insula on negatively-valenced, inhibitory trials predicted greater substance abuse one month and one year after the MRI scan among individuals high in negative urgency. These results suggest that, among people whose negative emotions often lead to self-control failure, excessive reactivity of the brain's regulatory resources may be the culprit.

  17. Variations in the Produce-Associated Microbiota and the Occurrence Frequency of Extended-Spectrum Beta-Lactamase Gram-Negative Bacteria Result in Different Level of Ingestion Risks

    KAUST Repository

    Bokhari, Osama

    2016-04-01

    A monitoring effort that spanned across one and a half years was conducted to examine three types of produce-associated microbiota. Produce type was determined to be the predominant factor affecting the microbial communities. Other significant factors that resulted in differences in the microbial populations were the origin and sampling date. Specifically, produce-associated microbiota among lettuce and tomatoes clustered based on the sampling period. Through molecular and cultivation-based approaches, sporadic presence of extended spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae and Acinetobacter baumannii was detected on lettuce and cucumbers during certain periods of sampling. Quantitative microbial risk assessment denoted varying levels of ingestion risks associated with different types of produce. In particular, the risks arising from ESBL-positive K. pneumoniae in the lettuce were higher than the acceptable annual risk of 10-4. Commonly used approaches to clean and wash the produce were insufficient in removing majority of the produce-associated microbiota. More invasive cleaning approaches or thorough cooking of the produce would be required to mitigate the associated risks. Most of the current reports of ESBL-positive bacterial isolates were identified in nosocomial environment. However, the carriage of such drug-resistant bacteria in food that is consumed daily

  18. Causality, Non-Locality and Negative Refraction

    CERN Document Server

    Forcella, Davide; Carminati, Rémi

    2016-01-01

    The importance of spatial non-locality in the description of negative refraction in electromagnetic materials has been put forward recently. We develop a theory of negative refraction in homogeneous and isotropic media, based on first principles, and that includes non-locality in its full generality. The theory shows that both dissipation and spatial non-locality are necessary conditions for the existence of negative refraction. It also provides a sufficient condition in materials with weak spatial non-locality. These fundamental results should have broad implications in the theoretical and practical analyses of negative refraction of electromagnetic and other kinds of waves.

  19. Analyzing negative ties in social networks

    Directory of Open Access Journals (Sweden)

    Mankirat Kaur

    2016-03-01

    Full Text Available Online social networks are a source of sharing information and maintaining personal contacts with other people through social interactions and thus forming virtual communities online. Social networks are crowded with positive and negative relations. Positive relations are formed by support, endorsement and friendship and thus, create a network of well-connected users whereas negative relations are a result of opposition, distrust and avoidance creating disconnected networks. Due to increase in illegal activities such as masquerading, conspiring and creating fake profiles on online social networks, exploring and analyzing these negative activities becomes the need of hour. Usually negative ties are treated in same way as positive ties in many theories such as balance theory and blockmodeling analysis. But the standard concepts of social network analysis do not yield same results in respect of each tie. This paper presents a survey on analyzing negative ties in social networks through various types of network analysis techniques that are used for examining ties such as status, centrality and power measures. Due to the difference in characteristics of flow in positive and negative tie networks some of these measures are not applicable on negative ties. This paper also discusses new methods that have been developed specifically for analyzing negative ties such as negative degree, and h∗ measure along with the measures based on mixture of positive and negative ties. The different types of social network analysis approaches have been reviewed and compared to determine the best approach that can appropriately identify the negative ties in online networks. It has been analyzed that only few measures such as Degree and PN centrality are applicable for identifying outsiders in network. For applicability in online networks, the performance of PN measure needs to be verified and further, new measures should be developed based upon negative clique concept.

  20. Brilliant but Cruel: Perceptions of Negative Evaluators.

    Science.gov (United States)

    Amabile, Teresa M.

    Two studies examined the hypothesis that negative evaluators will be perceived as more intelligent than positive evalutors. Two types of stimuli were used: excerpts from actual negative and positive book reviews, and versions of those excerpts that were edited so that the balance of the reviews varied but the content did not. The results strongly…

  1. Negative refractive index metamaterials

    Directory of Open Access Journals (Sweden)

    Willie J. Padilla

    2006-07-01

    Full Text Available Engineered materials composed of designed inclusions can exhibit exotic and unique electromagnetic properties not inherent in the individual constituent components. These artificially structured composites, known as metamaterials, have the potential to fill critical voids in the electromagnetic spectrum where material response is limited and enable the construction of novel devices. Recently, metamaterials that display negative refractive index – a property not found in any known naturally occurring material – have drawn significant scientific interest, underscoring the remarkable potential of metamaterials to facilitate new developments in electromagnetism.

  2. On Translation of Negative Sentences

    Institute of Scientific and Technical Information of China (English)

    谭利彬

    2007-01-01

    The English language has its peculiarities in negation.And the method of negation in English is quite different from that in Chinese.In order to fully understand the negative sentence in English,we should make clear the classification and key points of negation first.

  3. On Translation of Negative Sentences

    Institute of Scientific and Technical Information of China (English)

    谭利彬

    2007-01-01

    The English language has its peculiarities in negation. And the method of negation in English is quite different from that in Chinese. In order to fully understand the negative sentence in English, we should make clear the classification and key points of negation first.

  4. Classroom Management and Negative Reinforcement.

    Science.gov (United States)

    Tauber, Robert T.

    Of the four simple consequences for behavior, none is more misunderstood than negative reinforcement. A Negative Reinforcement Quiz administered to 233 student teachers from two universities revealed that the vast majority of respondents mistakenly viewed negative reinforcement as a synonym for punishment, and believe that negative reinforcement…

  5. Cosmology With Negative Potentials

    CERN Document Server

    Felder, G; Kofman, L A; Linde, Andrei D; Felder, Gary; Frolov, Andrei; Kofman, Lev; Linde, Andrei

    2002-01-01

    We investigate cosmological evolution in models where the effective potential V(\\phi) may become negative for some values of the field \\phi. Phase portraits of such theories in space of variables (\\phi,\\dot\\phi,H) have several qualitatively new features as compared with phase portraits in the theories with V(\\phi) > 0. Cosmological evolution in models with potentials with a "stable" minimum at V(\\phi)<0 is similar in some respects to the evolution in models with potentials unbounded from below. Instead of reaching an AdS regime dominated by the negative vacuum energy, the universe reaches a turning point where its energy density vanishes, and then it contracts to a singularity with properties that are practically independent of V(\\phi). We apply our methods to investigation of the recently proposed cyclic universe scenario. We show that in addition to the singularity problem there are other problems that need to be resolved in order to realize a cyclic regime in this scenario. We propose several modificati...

  6. Negative leave balances

    CERN Document Server

    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...

  7. Negative leave balances

    CERN Document Server

    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...

  8. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  9. Polarized negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Haeberli, W.

    1981-04-01

    This paper presents a survey of methods, commonly in use or under development, to produce beams of polarized negative ions for injection into accelerators. A short summary recalls how the hyperfine interaction is used to obtain nuclear polarization in beams of atoms. Atomic-beam sources for light ions are discussed. If the best presently known techniques are incorporated in all stages of the source, polarized H/sup -/ and D/sup -/ beams in excess of 10 ..mu..A can probably be achieved. Production of polarized ions from fast (keV) beams of polarized atoms is treated separately for atoms in the H(25) excited state (Lamb-Shift source) and atoms in the H(1S) ground state. The negative ion beam from Lamb-Shift sources has reached a plateau just above 1 ..mu..A, but this beam current is adequate for many applications and the somewhat lower beam current is compensated by other desirable characteristics. Sources using fast polarized ground state atoms are in a stage of intense development. The next sections summarize production of polarized heavy ions by the atomic beam method, which is well established, and by optical pumping, which has recently been demonstrated to yield very large nuclear polarization. A short discussion of proposed ion sources for polarized /sup 3/He/sup -/ ions is followed by some concluding remarks.

  10. Negative-permittivity plasma generation in negative-permeability space with high-energy metamaterials

    Science.gov (United States)

    Sakai, Osamu; Nakamura, Yoshihiro; Iwai, Akinori; Iio, Satoshi

    2016-10-01

    Plasma generation by electromagnetic waves in negative-permeability space is analyzed using experimental results and theoretical models. Installation of negative-permeability metamaterials triggers drastic changes to the propagation of electromagnetic waves. Unlike usual cases in which permeability is  +1, negative permeability induces evanescent modes in a space without plasma. However, if permittivity becomes negative due to high-electron-density or overdense plasma, electromagnetic waves can propagate because negative-refractive-index states emerge. In this study, reviewing our previous experimental data, we study the underlying physical processes in plasma generation in terms of wave propagation and parameters of wave media. We confirm nonlinear (transition) processes in the phase of density evolution up to the negative permittivity state and negative-refractive-index states in the quasi-steady phase. We also note that such energetic metamaterials are built up when we use plasma, unlike conventional metamaterials composed of solid-state materials.

  11. Negated bio-events: analysis and identification

    Directory of Open Access Journals (Sweden)

    Nawaz Raheel

    2013-01-01

    Full Text Available Abstract 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

  12. 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.

  13. Negative Expertise: Comparing Differently Tenured Elder Care Nurses' Negative Knowledge

    Science.gov (United States)

    Gartmeier, Martin; Lehtinen, Erno; Gruber, Hans; Heid, Helmut

    2011-01-01

    Negative expertise is conceptualised as the professional's ability to avoid errors during practice due to certain cognitive agencies. In this study, negative knowledge (i.e. knowledge about what is wrong in a certain context and situation) is conceptualised as one such agency. This study compares and investigates the negative knowledge of elder…

  14. Brand Suicide? Memory and Liking of Negative Brand Names

    Science.gov (United States)

    Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

    2016-01-01

    Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name. PMID:27023872

  15. Brand Suicide? Memory and Liking of Negative Brand Names.

    Directory of Open Access Journals (Sweden)

    Duncan Guest

    Full Text Available Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink, yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name.

  16. Brand Suicide? Memory and Liking of Negative Brand Names.

    Science.gov (United States)

    Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

    2016-01-01

    Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name.

  17. Negative temperatures and the definition of entropy

    Science.gov (United States)

    Swendsen, Robert H.; Wang, Jian-Sheng

    2016-07-01

    The concept of negative temperature has recently received renewed interest in the context of debates about the correct definition of the thermodynamic entropy in statistical mechanics. Several researchers have identified the thermodynamic entropy exclusively with the "volume entropy" suggested by Gibbs, and have further concluded that by this definition, negative temperatures violate the principles of thermodynamics. We disagree with these conclusions. We demonstrate that volume entropy is inconsistent with the postulates of thermodynamics for systems with non-monotonic energy densities, while a definition of entropy based on the probability distributions of macroscopic variables does satisfy the postulates of thermodynamics. Our results confirm that negative temperature is a valid extension of thermodynamics.

  18. Negative Index of Refraction in Optical Metamaterials

    CERN Document Server

    Shalaev, V M; Chettiar, U; Yuan, H K; Sarychev, A K; Drachev, V P; Kildishev, A V; Shalaev, Vladimir M.; Cai, Wenshan; Chettiar, Uday; Yuan, Hsiao-Kuan; Sarychev, Andrey K.; Drachev, Vladimir P.; Kildishev, Alexander V.

    2005-01-01

    An array of pairs of parallel gold nanorods is shown to have a negative refractive index in the optical range, close to a wavelength of 1 micron. Such behavior results from the plasmon resonance in the pairs of nanorods for both the electric and magnetic components of light. The metal rods act as inductive elements whereas the dielectric gaps perform as capacitive elements, forming an optical LC-circuit. Our experiments and simulations demonstrate the resonant behavior for an index of refraction. Above the resonance, the refractive index becomes negative. Paired metal nanorods open new opportunities for developing negative-refraction materials in optics.

  19. On multiphase negative flash for ideal solutions

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2012-01-01

    coefficients. It is shown that this inner loop, named here as multiphase negative flash for ideal solutions, can be solved either by Michelsen's algorithm for multiphase normal flash, or by its variation which uses F−1 phase amounts as independent variables. In either case, the resulting algorithm is actually...... simpler than the corresponding normal flash algorithm. Unlike normal flash, multiphase negative flash for ideal solutions can diverge if the feasible domain for phase amounts is not closed. This can be judged readily during the iteration process. The algorithm can also be extended to the partial negative...

  20. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

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

    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......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...

  1. The case for negative senescence

    DEFF Research Database (Denmark)

    Vaupel, James W; Baudisch, Annette; Dölling, Martin;

    2004-01-01

    Negative senescence is characterized by a decline in mortality with age after reproductive maturity, generally accompanied by an increase in fecundity. Hamilton (1966) ruled out negative senescence: we adumbrate the deficiencies of his model. We review empirical studies of various plants and some...... kinds of animals that may experience negative senescence and conclude that negative senescence may be widespread, especially in indeterminate-growth species for which size and fertility increase with age. We develop optimization models of life-history strategies that demonstrate that negative senescence...

  2. Contingent negative variation of mood disorder patients

    Institute of Scientific and Technical Information of China (English)

    Yingzhi Lu; Wenbin Zong; Qingtao Ren; Jinyu Pu; Jun Chen; Juan Li; Xingshi Chen; Yong Wang

    2011-01-01

    Studies on brain-evoked potential and contingent negative variation (CNV) in mood disorder remain controversial. To date, no CNV difference between unipolar and bipolar depression has been reported. Brain-evoked potentials were measured in the present study to analyze CNV in three subtypes of mood disorder (mania, unipolar depression, and bipolar depression), and these results were compared with normal controls. In the mania group, CNV amplitude B was greater than in controls, and the depression group exhibited lower CNV amplitude B and smaller A-S'2 area, and prolonged post-imperative negative variation latency. The CNV comparison between unipolar and bipolar depression found that the prolonged post-imperative negative variation latency was only in unipolar depression. These results suggest that prolonged post-imperative negative variation latency is a characteristic of unipolar depression, and CNV amplitude change is a state characteristic of mood disorder patients.

  3. Analyzing negative ties in social networks

    OpenAIRE

    Mankirat Kaur; Sarbjeet Singh

    2016-01-01

    Online social networks are a source of sharing information and maintaining personal contacts with other people through social interactions and thus forming virtual communities online. Social networks are crowded with positive and negative relations. Positive relations are formed by support, endorsement and friendship and thus, create a network of well-connected users whereas negative relations are a result of opposition, distrust and avoidance creating disconnected networks. Due to increase i...

  4. Underpowered samples, false negatives, and unconscious learning

    OpenAIRE

    Vadillo, M. A.; Konstantinidis, E.; Shanks, D.R.

    2016-01-01

    The scientific community has witnessed growing concern about the high rate of false positives and unreliable results within the psychological literature, but the harmful impact of false negatives has been largely ignored. False negatives are particularly concerning in research areas where demonstrating the absence of an effect is crucial, such as studies of unconscious or implicit processing. Research on implicit processes seeks evidence of above-chance performance on some implicit behavioral...

  5. Information Filtering Based on Users' Negative Opinions

    Science.gov (United States)

    Guo, Qiang; Li, Yang; Liu, Jian-Guo

    2013-05-01

    The process of heat conduction (HC) has recently found application in the information filtering [Zhang et al., Phys. Rev. Lett.99, 154301 (2007)], which is of high diversity but low accuracy. The classical HC model predicts users' potential interested objects based on their interesting objects regardless to the negative opinions. In terms of the users' rating scores, we present an improved user-based HC (UHC) information model by taking into account users' positive and negative opinions. Firstly, the objects rated by users are divided into positive and negative categories, then the predicted interesting and dislike object lists are generated by the UHC model. Finally, the recommendation lists are constructed by filtering out the dislike objects from the interesting lists. By implementing the new model based on nine similarity measures, the experimental results for MovieLens and Netflix datasets show that the new model considering negative opinions could greatly enhance the accuracy, measured by the average ranking score, from 0.049 to 0.036 for Netflix and from 0.1025 to 0.0570 for Movielens dataset, reduced by 26.53% and 44.39%, respectively. Since users prefer to give positive ratings rather than negative ones, the negative opinions contain much more information than the positive ones, the negative opinions, therefore, are very important for understanding users' online collective behaviors and improving the performance of HC model.

  6. 微核试验数据的Poisson和负二项回归模型拟合效果比较%Comparison of Fitting Results of Poisson Regression and Negative Binomial Regression Models for Data of Cytokinesis-block Micronucleus Test

    Institute of Scientific and Technical Information of China (English)

    郑辉烈; 王增珍; 俞慧强

    2011-01-01

    Objective To compare the fitting results of the Poisson regression model and negative binomial regression model for data of cytokinesis-block micronucleus test, and to provide a basis for statistical analysis of data of cytokinesis-block micronucleus test. Methods By using the log likelihood function,the deviance,Pearson x2 and cluster index, the fitting results of Poisson regression model and the negative binomial regression model for data of cytokinesis-block micronucleus test were evaluated. Result The ratio of log lielihood function to degree of freedom for negative binomial regression was greater than that for Poisson regression. The ratio of deviance to degree of freedom and the ratio of Pearson x2 to degree of freedom for negative binomial regression were less than those for Poisson regression. There was a significant difference in cluster index that was not equal to zero for negative binomial regression model(x2= 1 160.42, P<0.001).Conclusion The negative binomial regression model was superior to Poisson regression model for data of cytokinesis-block micronucleus test.%目的 比较Poisson和负二项回归模型对微核试验数据(每1 000个双核淋巴细胞中具有微核的淋巴细胞数)的拟合效果,为微核试验数据的模型拟合提供依据.方法 运用微核试验数据,拟合Poisson分布和负二项分布回归模型,采用对数似然函数、偏差统计量、Pearson χ2统计量和聚集性指数等指标比较2种回归模型对实例数据的拟合效果.结果 负二项回归模型对数似然函数值与自由度的比值(-2.51)大于Poisson回归模型(-3.52);负二项回归模型拟合优度统计量-偏差统计量和Pearson χ2统计量与对应的自由度比值(1.16和1.07)小于Poisson回归模型;聚集性指数的似然比检验(H0:k=0)显示,聚集性指数不等于0具有统计学意义(χ2=1 160.42,P<0.001).结论对于微核试验数据,拟合负二项回归模型要优于Poisson回归模型.

  7. 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.

  8. Pharmacological treatment of negative symptoms in schizophrenia.

    Science.gov (United States)

    Möller, Hans-Jürgen; Czobor, Pal

    2015-10-01

    Effective treatment of negative symptoms is one of the most important unmet needs in schizophrenic disorders. Because the evidence on current psychopharmacological treatments is unclear, the authors reviewed the findings published to date by searching PubMed with the keywords negative symptoms, antipsychotics, antidepressants, glutamatergic compounds, monotherapy and add-on therapy and identifying additional articles in the reference lists of the resulting publications. The findings presented here predominantly focus on results of meta-analyses. Evidence for efficacy of current psychopharmacological medications is difficult to assess because of methodological problems and inconsistent results. In general, the second-generation antipsychotics (SGAs) do not appear to have good efficacy in negative symptoms, although some show better efficacy than first-generation antipsychotics, some of which also demonstrated efficacy in negative symptoms. Specific trials on predominant persistent negative symptoms are rare and have been performed with only a few SGAs. More often, trials on somewhat persistent negative symptoms evaluate add-on strategies to ongoing antipsychotic treatment. Such trials, mostly on modern antidepressants, have demonstrated some efficacy. Several trials with small samples have evaluated add-on treatment with glutamatergic compounds, such as the naturally occurring amino acids glycine and D-serine and new pharmacological compounds. The results are highly inconsistent, although overall efficacy results appear to be positive. The unsatisfactory and inconsistent results can be partially explained by methodological problems. These problems need to be solved in the future, and the authors propose some possible solutions. Further research is required to identify effective treatment for the negative symptoms of schizophrenia.

  9. Congenital nystagmus and negative electroretinography

    Directory of Open Access Journals (Sweden)

    Roussi M

    2011-04-01

    Full Text Available Mirella Roussi, Hélène Dalens, Jean Jacques Marcellier, Franck BacinDepartment of Ophthalmology, Clermont-Ferrand University, Clermont-Ferrand, FranceAbstract: Congenital nystagmus is a pathologic oculomotor state appearing at about three to four months of age. The precise diagnosis requires detailed clinical examination and electrophysiological findings. This case report presents two male patients with congenital nystagmus examined longitudinally from the age of six months until 17-18 years of age. Clinical and electrophysiological protocols were detailed. The first results showed electronegative electroretinography in the two cases and examination combined with electroretinographic findings helped us to make the diagnosis of Congenital Night Stationary Blindness (CSNB. This diagnosis was confirmed by genetic studies. CSNB is interesting to study because through electrophysiological findings, it enables a better understanding of the physiology of neural transmission in the outer part of the retina.Keywords: Congenital nystagmus, negative electroretinography, congenital night stationary blindness

  10. Reactions of Negative Ions

    Science.gov (United States)

    1984-07-17

    2 + H2 SO 4 + HS04 (HNO 3 ) 2 + HNO 3 1.1 0.6 * defined as 1 The most important results from an atmospheric viewpoint are the reactions of H SO with NO...constant HS04 >4.5 bracketing 22 0 C1 , 1.95 * 0.25 bracketlng 32 -4 __.. . .___,_=____,,_______... . . . -- . . . . One particularly interesting aspect of

  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. On Negation as Mitigation: The Case of Negative Irony

    Science.gov (United States)

    Giora, Rachel; Fein, Ofer; Ganzi, Jonathan; Levi, Natalie Alkeslassy; Sabah, Hadas

    2005-01-01

    Four experiments support the view of negation as mitigation (Giora, Balaban, Fein, & Alkabets, 2004). They show that when irony involves some sizable gap between what is said and what is criticized (He is exceptionally bright said of an idiot), it is rated as highly ironic (Giora, 1995). A negated version of that overstatement (He is not…

  13. Income, Amenities and Negative Attitudes

    DEFF Research Database (Denmark)

    Waisman, Gisela; Larsen, Birthe

    2016-01-01

    ’ 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......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...

  14. Prestarlike functions with negative coefficients

    Directory of Open Access Journals (Sweden)

    H. Silverman

    1979-01-01

    Full Text Available The extreme points for prestarlike functions having negative coefficients are determined. Coefficient, distortion and radii of univalence, starlikeness, and convexity theorems are also obtained.

  15. Neuroimaging correlates of negative priming.

    Science.gov (United States)

    Steel, C; Haworth, E J; Peters, E; Hemsley, D R; Sharma, T; Gray, J A; Pickering, A; Gregory, L; Simmons, A; Bullmore, E T; Williams, S C

    2001-11-16

    Many theoretical accounts of selective attention and memory retrieval include reference to active inhibitory processes, such as those argued to underlie the negative priming effect. fMRI was used in order to investigate the areas of cortical activation associated with Stroop interference, Stroop facilitation and Stroop negative priming tasks. The most significant activation within the negative priming task was within the inferior parietal lobule, left temporal lobe and frontal lobes. Areas of cortical activation are discussed with reference to theoretical accounts of the negative priming effect.

  16. Neurobiological background of negative symptoms.

    Science.gov (United States)

    Galderisi, Silvana; Merlotti, Eleonora; Mucci, Armida

    2015-10-01

    Studies investigating neurobiological bases of negative symptoms of schizophrenia failed to provide consistent findings, possibly due to the heterogeneity of this psychopathological construct. We tried to review the findings published to date investigating neurobiological abnormalities after reducing the heterogeneity of the negative symptoms construct. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, genetics and neurobiology of schizophrenia. We searched PubMed with the keywords "negative symptoms," "deficit schizophrenia," "persistent negative symptoms," "neurotransmissions," "neuroimaging" and "genetic." Additional articles were identified by manually checking the reference lists of the relevant publications. Publications in English were considered, and unpublished studies, conference abstracts and poster presentations were not included. Structural and functional imaging studies addressed the issue of neurobiological background of negative symptoms from several perspectives (considering them as a unitary construct, focusing on primary and/or persistent negative symptoms and, more recently, clustering them into factors), but produced discrepant findings. The examined studies provided evidence suggesting that even primary and persistent negative symptoms include different psychopathological constructs, probably reflecting the dysfunction of different neurobiological substrates. Furthermore, they suggest that complex alterations in multiple neurotransmitter systems and genetic variants might influence the expression of negative symptoms in schizophrenia. On the whole, the reviewed findings, representing the distillation of a large body of disparate data, suggest that further deconstruction of negative symptomatology into more elementary components is needed to gain insight into underlying neurobiological mechanisms.

  17. Negative Plasma Densities Raise Questions

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A

    2006-01-26

    Nearly all the matter encountered on Earth is either a solid, liquid, or gas. Yet plasma-the fourth state of matter-comprises more than 99 percent of the visible universe. Understanding the physical characteristics of plasmas is important to many areas of scientific research, such as the development of fusion as a clean, renewable energy source. Lawrence Livermore scientists study the physics of plasmas in their pursuit to create fusion energy, because plasmas are an integral part of that process. When deuterium and tritium are heated to the extreme temperatures needed to achieve and sustain a fusion reaction (about 100 million degrees), the electrons in these light atoms become separated from the nuclei. This process of separation is called ionization, and the resulting collection of negatively charged free electrons and positively charged nuclei is known as a plasma. Although plasmas and gases have many similar properties, plasmas differ from gases in that they are good conductors of electricity and can generate magnetic fields. For the past decade, x-ray laser interferometry has been used in the laboratory for measuring a plasma's index of refraction to determine plasma density. (The index of refraction for a given material is defined as the wavelength of light in a vacuum divided by the wavelength of light traveling through the material.) Until now, plasma physicists expected to find an index of refraction less than one. Researchers from Livermore and Colorado State University recently conducted experiments on aluminum plasmas at the Laboratory's COMET laser facility and observed results in which the index of refraction was greater than one. This surprising result implied a negative electron density. Livermore physicist Joseph Nilsen and his colleagues from Livermore and the University of Notre Dame have performed sophisticated calculations to explain this phenomenon. Previously, researchers believed that only free electrons contributed to the index

  18. Queries with Guarded Negation (full version)

    CERN Document Server

    Barany, Vince; Otto, Martin

    2012-01-01

    A well-established and fundamental insight in database theory is that negation (also known as complementation) tends to make queries difficult to process and difficult to reason about. Many basic problems are decidable and admit practical algorithms in the case of unions of conjunctive queries, but become difficult or even undecidable when queries are allowed to contain negation. Inspired by recent results in finite model theory, we consider a restricted form of negation, guarded negation. We introduce a fragment of SQL, called GN-SQL, as well as a fragment of Datalog with stratified negation, called GN-Datalog, that allow only guarded negation, and we show that these query languages are computationally well behaved, in terms of testing query containment, query evaluation, open-world query answering, and boundedness. GN-SQL and GN-Datalog subsume a number of well known query languages and constraint languages, such as unions of conjunctive queries, monadic Datalog, and frontier-guarded tgds. In addition, an a...

  19. Negative phototropism of rice root

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@It is often believed that the stem of higher plants has characteristics of positive phototropism, and the root shows no phototropism or no sensitivity to light though the root of Arabdopsis was reported possessing characteristics of negative phototropism. In this study, a distinct negative phototropism of the root system of rice seedlings was observed.

  20. Negative supervisionsoplevelser og deres konsekvenser

    DEFF Research Database (Denmark)

    Nielsen, Jan

    2011-01-01

    in evaluation. First part of the paper explores negative experience in supervision in general. The second part, focusing on negative experience in supervision caused by evaluation, is explored and discussed in relation to the key concept of supervisory alliance (Bordin, 1983), perceiving evaluation...

  1. Be Aware of Negative Reinforcement.

    Science.gov (United States)

    Cipani, Ennio C.

    1995-01-01

    This article examines the concept of negative reinforcement in relation to the maintenance of off-task and disruptive behaviors in classrooms. Suggestions are given for determining whether negative reinforcement (in the form of escape from the instructional task) or teacher attention is maintaining the behavior. Suggestions for making tasks less…

  2. Negative refraction in outer space?

    OpenAIRE

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2004-01-01

    Mediums which do not support the propagation of plane waves with negative phase velocity (NPV) when viewed at rest can support NPV propagation when they are viewed in a reference frame which is uniformly translated at sufficiently high velocity. Thus, relativistic negative refraction may be exploited in astronomical scenarios.

  3. Conditional negative association for competing urns

    CERN Document Server

    Kahn, Jeff

    2010-01-01

    Competing urns refers to the random experiment where m balls are dropped, randomly and independently, into urns 1,...,n. Formally, we have a random map $\\sigma$ from {1,...,m} to {1,...,n} with the $\\sigma(i)$'s i.i.d. With $x_j$ the indicator of the event that at least $t_j$ balls land in urn j (for some threshold $t_j$), we prove conditional negative association for the random variables $x_1,...,x_n$. We mostly deal with the more general situation in which the $\\sigma(i)$'s need not be identically distributed, proving results which imply conditional negative association in the i.i.d. case. Some of the results--particularly Lemma 8 on graph orientations--are thought to be of independent interest. We also give a counterexample to a negative correlation conjecture of D. Welsh, a strong version of a (still open) conjecture of G. Farr.

  4. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

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

    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......, 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...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  5. Cognitive representation of negative numbers.

    Science.gov (United States)

    Fischer, Martin H

    2003-05-01

    To understand negative numbers, must we refer to positive number representations (the phylogenetic hypothesis), or do we acquire a negative mental number line (the ontogenetic hypothesis)? In the experiment reported here, participants made lateralized button responses to indicate the larger of two digits from the range -9 to 9. Digit pairs were displayed spatially congruent or incongruent with either a phylogenetic or an ontogenetic mental number line. The pattern of decision latencies suggests that negative numbers become associated with left space, thus supporting the ontogenetic view.

  6. Assessment of Negative Self-Image and Fear of Negative Evaluation Among Adolescents and Young Adults

    Institute of Scientific and Technical Information of China (English)

    Agbu Jane-Frances; Ibida Ebele

    2014-01-01

    Concern with real or imagined defect in physical appearance can become a major preoccupation during adolescence and young adult years. This is because, changes of puberty, rapid physical growth, and resulting sexual maturation that characterizes this age can trigger feelings of self-consciousness and awkwardness about body-image perceptions. In addition, the "perfect" body-image as dictated in the social culture could become a measure of self-worth, and this is capable of triggering negative self-image and social anxiety among adolescents. This study seeks to assess the incidence of negative self-image (preoccupation with real or imagined defect in physical appearance) and social anxiety characterized by fear of negative evaluation, among adolescents and young adults. Samples of 329 participants in the age range of 16-25 were drawn from the first and second years students of Federal University Wukari and University of Lagos, Nigeria. Participants completed a socio-demographic data sheet as well as NSII (Negative Self-Image Inventory) and revalidated version of FNE (Fear of Negative Evaluation). Findings revealed that there is a correlation between negative self-image and fear of negative evaluation; males manifested higher symptoms of negative self-image than females; young adults aged 21-25 presented higher negative self-image that those aged 16-20, adolescents and young adults from Lagos metropolis experience higher manifestation of fear of negative evaluation than those from Wukari axis. This study therefore adds to knowledge in this area.

  7. Adjective metaphors evoke negative meanings.

    Science.gov (United States)

    Sakamoto, Maki; Utsumi, Akira

    2014-01-01

    Previous metaphor studies have paid much attention to nominal metaphors and predicative metaphors, but little attention has been given to adjective metaphors. Although some studies have focused on adjective metaphors, they only examined differences in the acceptability of various types of adjective metaphors. This paper explores the cognitive effects evoked by adjective metaphors. Three psychological experiments revealed that (1) adjective metaphors, especially those modified by color adjectives, tend to evoke negative effect; (2) although the meanings of metaphors are basically affected by the meanings of their vehicles, when a vehicle has a neutral meaning, negative meanings are evoked most frequently for adjective metaphors compared to nominal and predicative metaphors; (3) negative meanings evoked by adjective metaphors are related to poeticness, and poetic metaphors evoke negative meanings more easily than less poetic metaphors. Our research sheds new light on studies of the use of metaphor, which is one of the most basic human cognitive abilities.

  8. Negative effects of positive reinforcement

    OpenAIRE

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive—those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say t...

  9. Use of Negation in Search

    Science.gov (United States)

    2010-06-01

    number of individuals indicated that negation was valuable for them in their shopping on Craigslist and eBay , particularly for collectible items...research or in a quest for rare collectibles on eBay , is sufficient cause for further investigation into the notion of negation in search. Research...that use of advanced search syntax is correlated with users being online for more time, “spend[ing] less time querying and traversing search trails” (p

  10. 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.

  11. Negative refraction in photonic crystals

    OpenAIRE

    Baba, T.; Matsumoto, T.; Asatsuma, T.

    2008-01-01

    Photonic crystals are multidimensional periodic gratings, in which the light propagation is dominated by Bragg diffraction that appears to be refraction at the flat surfaces of the crystals. The refraction angle from positive to negative, perfectly or only partially obeying Snell’s law, can be tailored based on photonic band theory. Negative refraction enables novel prism, collimation, and lens effects. Because photonic crystals usually consist of two transparent media, these effects occur at...

  12. Negative differential resistance in molecular conductors

    Science.gov (United States)

    Kozhushner, Mortko; Oleynik, Ivan

    2007-03-01

    Negative differential resistance σd=dI/dVassymetrical. This results in an initial increase of the resonant molecular current as a resonant level appears in the interval of energies [EF, EF-eV] and a subsequent decrease of the current as the asymmetry in localization at the right and left interfaces is amplified upon further increase of applied bias.

  13. More Negative Findings for Positive Prepositions.

    Science.gov (United States)

    Abkarian, G. G.

    1983-01-01

    Three- and four-year-old children were tested in their comprehension of locative prepositions. Results showed that those prepositions characterized as positive were comprehended less well than their ostensibly negative counterparts, contrary to theoretical predictions. An explanatory hypothesis concerning children's developing spatial…

  14. NEGATIVE MAXWELL-STEFAN DIFFUSION-COEFFICIENTS

    NARCIS (Netherlands)

    KRAAIJEVELD, G; WESSELINGH, JA

    1993-01-01

    The existence of negative Maxwell-Stefan diffusivities is investigated. For the case where the diffusion coefficients are taken to be composition dependent, it is found that the theory of irreversible thermodynamics does not require all diffusivities to be positive definite. This theoretical result

  15. On affine non-negative matrix factorization

    DEFF Research Database (Denmark)

    Laurberg, Hans; Hansen, Lars Kai

    2007-01-01

    We generalize the non-negative matrix factorization (NMF) generative model to incorporate an explicit offset. Multiplicative estimation algorithms are provided for the resulting sparse affine NMF model. We show that the affine model has improved uniqueness properties and leads to more accurate...

  16. Experimental study of negative capacitance in LEDs

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-feng; WANG Jun; ZHU Chuan-yun; CONG Hong-xia; CHEN Yong; WANG Cun-da

    2005-01-01

    The experimental study on negative capacitance(NC) of various light-emitting diodes(LEDs) is presented.Experimental result shows that all LEDs display the NC phenomenon.The voltage modulated electroluminescence(VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence.The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar: NC phenomenon is more obvious with higher voltage or lower frequency.

  17. Negative numbers are generated in the mind.

    Science.gov (United States)

    Ganor-Stern, Dana; Tzelgov, Joseph

    2008-01-01

    The goal of the present study was to disentangle two possible representations of negative numbers--the holistic representation, where absolute magnitude is integrated with polarity; and the components representation, where absolute magnitude is stored separately from polarity. Participants' performance was examined in two tasks involving numbers from--100 to 100. In the numerical comparison task, participants had to decide which number of a pair was numerically larger/smaller. In the number line task, participants were presented with a spatial number line on which they had to place a number. The results of both tasks support the components representation of negative numbers. The findings suggest that processing of negative numbers does not involve retrieval of their meaning from memory, but rather the integration of the polarity sign with the digits' magnitudes.

  18. Numerical Simulation of a Negative Impulsive Wave

    Institute of Scientific and Technical Information of China (English)

    ToshiakiSETOGUCHI; ShenYU; 等

    1996-01-01

    A compression wave discharged from an open end of a tube causes positive impulsive noise,Active noise cancellation which is the cancelling of the noise by the addition of an inverse wave is a useful technique for reducing impulsive noise,The main objective of this study is to present the design for a negative impulsive wave generator utilizing unsteady mass influx.In this paper,in order to clarify the relationship between the unsteady mass influx and the negative impulsive wave,numerical and aeroacoustic analyses have been carried out using an unsteady expansion wave discharged from an open end of a shock tube.As a result,the effect of an unsteady expansion wave on a negative impulsive wave was charified.

  19. A new bivariate negative binomial regression model

    Science.gov (United States)

    Faroughi, Pouya; Ismail, Noriszura

    2014-12-01

    This paper introduces a new form of bivariate negative binomial (BNB-1) regression which can be fitted to bivariate and correlated count data with covariates. The BNB regression discussed in this study can be fitted to bivariate and overdispersed count data with positive, zero or negative correlations. The joint p.m.f. of the BNB1 distribution is derived from the product of two negative binomial marginals with a multiplicative factor parameter. Several testing methods were used to check overdispersion and goodness-of-fit of the model. Application of BNB-1 regression is illustrated on Malaysian motor insurance dataset. The results indicated that BNB-1 regression has better fit than bivariate Poisson and BNB-2 models with regards to Akaike information criterion.

  20. Analysis of the results of antinuclear antibody spectrum which antinuclear antibody were negative and assessment of the risks of disease%抗核抗体阴性病例的抗核抗体谱的检测分析与疾病风险的评估

    Institute of Scientific and Technical Information of China (English)

    卢伟; 刘斌剑; 梁艳; 杨再兴

    2016-01-01

    Objective By analyzing the results of antinuclear antibody spectrum(ANAs)which antinuclear antibody (ANA)were negative,to explore the correlation between them and make clinical assessment of the risks of disease. Methods Make a statistics of the results of serum ANAs cases which ANA were negative and clinical data of 6003 dif-ferent patients came from outpatient and?inpatient from 2011 until May 15,2014.The relationship among the results and their clinical significance were analyzed.Results Of 6003 ANA negative specimens,the positive rate of ANAs was 10.9%,the negative rate of ANAs was 89.1%,the positive rate of anti-SSA antibody was the first (3.9%),the posi-tive rate of anti-Ro-52 antibody was the second(3.6%).Of ANAs positive specimens,the weakly positive rate of anti-Sm,anti-SSB,anti-Scl-70 and anti-His antibodies were higher than the positive of them,the positive rate of anti-Ro-52 antibody was higher than the weakly positive,there were all with statistical significance (P <0.05).The total positive rate of single event’s antibody was the highest(8.7%).Of the weakly positive cases and positive cases of single event’ s antibody,the positive cases of two events’s antibody,the cases of one weak positive and the other positive of mixed e-vents’s antibody,the female positive rate was higher than the male and there was with statistical significance(P <0.05).In the different age group of ≤20 years old,21-49 years old and ≥50 years old,there was statistical significance of ANAs positive rate(6.2%,9.5% 12.6%,χ2 = 21.23,P < 0.05).Of 652 ANAs positive specimens,patients diag-nosed as autoimmune disease(AID)were 104 cases(16.0%).The positive antibodies of ANAs positive specimens were 162 cases,the positive rate of anti-Ro-52 antibody in the AID group was the first (30.9%),the positive rate of anti-SSA antibody was the second(28.4%).Of 5351 ANAs negative specimens,patients diagnosed as AID were 322 cases(6. 0%).The AID patients in ANAs positive specimens were

  1. Neural responses to negative feedback are related to negative emotionality in healthy adults

    Science.gov (United States)

    Santesso, Diane L.; Bogdan, Ryan; Birk, Jeffrey L.; Goetz, Elena L.; Holmes, Avram J.

    2012-01-01

    Prior neuroimaging and electrophysiological evidence suggests that potentiated responses in the anterior cingulate cortex (ACC), particularly the rostral ACC, may contribute to abnormal responses to negative feedback in individuals with elevated negative affect and depressive symptoms. The feedback-related negativity (FRN) represents an electrophysiological index of ACC-related activation in response to performance feedback. The purpose of the present study was to examine the FRN and underlying ACC activation using low resolution electromagnetic tomography source estimation techniques in relation to negative emotionality (a composite index including negative affect and subclinical depressive symptoms). To this end, 29 healthy adults performed a monetary incentive delay task while 128-channel event-related potentials were recorded. We found that enhanced FRNs and increased rostral ACC activation in response to negative—but not positive—feedback was related to greater negative emotionality. These results indicate that individual differences in negative emotionality—a putative risk factor for emotional disorders—modulate ACC-related processes critically implicated in assessing the motivational impact and/or salience of environmental feedback. PMID:21917847

  2. 22 A beam production of the uniform negative ions in the JT-60 negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masafumi, E-mail: yoshida.masafumi@jaea.go.jp [Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193 (Japan); Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko [Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193 (Japan); Grisham, Larry R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Hatayama, Akiyoshi; Shibata, Takanori; Yamamoto, Takashi [Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8511 (Japan); Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ohzeki, Masahiro; Seki, Norikazu; Sasaki, Shunichi; Shimizu, Tatsuo; Terunuma, Yuto [Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193 (Japan)

    2015-10-15

    Highlights: • In order to improve a uniformity of the negative ion beam and produce high current negative ion beam in the JT-60 negative ion source, a tent-shaped filter is applied. • Beam uniformity is improved from 68% to 83% over an area of the whole extraction area of 450 x 1100 mm{sup 2}. • The improvement of the beam uniformity leads to the production of 32 A H{sup −} ion beams with the whole extraction area. - Abstract: In order to improve the spatial uniformity of the negative ion beam and to produce high current negative ion beams in a large negative ion source, a magnetic field configuration is modified from an original transverse filter to a tent-shaped filter, in combination with reducing the magnetic field strength in the JT-60 negative ion source. As a result, the beam uniformity is improved from 68% to 83% over an area of the whole extraction area of 450 × 1100 mm{sup 2}. The improvement of the beam uniformity leads to the production of 32 A H{sup −} ion beams with the whole extraction area. The obtained beam current fulfills the requirement for JT-60SA.

  3. Giant negative thermal expansion in magnetic nanocrystals.

    Science.gov (United States)

    Zheng, X G; Kubozono, H; Yamada, H; Kato, K; Ishiwata, Y; Xu, C N

    2008-12-01

    Most solids expand when they are heated, but a property known as negative thermal expansion has been observed in a number of materials, including the oxide ZrW2O8 (ref. 1) and the framework material ZnxCd1-x(CN)2 (refs 2,3). This unusual behaviour can be understood in terms of low-energy phonons, while the colossal values of both positive and negative thermal expansion recently observed in another framework material, Ag3[Co(CN)6], have been explained in terms of the geometric flexibility of its metal-cyanide-metal linkages. Thermal expansion can also be stopped in some magnetic transition metal alloys below their magnetic ordering temperature, a phenomenon known as the Invar effect, and the possibility of exploiting materials with tuneable positive or negative thermal expansion in industrial applications has led to intense interest in both the Invar effect and negative thermal expansion. Here we report the results of thermal expansion experiments on three magnetic nanocrystals-CuO, MnF2 and NiO-and find evidence for negative thermal expansion in both CuO and MnF2 below their magnetic ordering temperatures, but not in NiO. Larger particles of CuO and MnF2 also show prominent magnetostriction (that is, they change shape in response to an applied magnetic field), which results in significantly reduced thermal expansion below their magnetic ordering temperatures; this behaviour is not observed in NiO. We propose that the negative thermal expansion effect in CuO (which is four times larger than that observed in ZrW2O8) and MnF2 is a general property of nanoparticles in which there is strong coupling between magnetism and the crystal lattice.

  4. Beyond natural numbers: negative number representation in parietal cortex.

    Science.gov (United States)

    Blair, Kristen P; Rosenberg-Lee, Miriam; Tsang, Jessica M; Schwartz, Daniel L; Menon, Vinod

    2012-01-01

    Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference 6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

  5. Input calibration for negative originals

    Science.gov (United States)

    Tuijn, Chris

    1995-04-01

    One of the major challenges in the prepress environment consists of controlling the electronic color reproduction process such that a perfect match of any original can be realized. Whether this goal can be reached depends on many factors such as the dynamic range of the input device (scanner, camera), the color gamut of the output device (dye sublimation printer, ink-jet printer, offset), the color management software etc. The characterization of the color behavior of the peripheral devices is therefore very important. Photographs and positive transparents reflect the original scene pretty well; for negative originals, however, there is no obvious link to either the original scene or a particular print of the negative under consideration. In this paper, we establish a method to scan negatives and to convert the scanned data to a calibrated RGB space, which is known colorimetrically. This method is based on the reconstruction of the original exposure conditions (i.e., original scene) which generated the negative. Since the characteristics of negative film are quite diverse, a special calibration is required for each combination of scanner and film type.

  6. Effects of suppressing negative memories on intrusions and autobiographical memory specificity

    NARCIS (Netherlands)

    Geraerts, Elke; Hauer, Beatrijs J. A.; Wessel, Ineke

    2010-01-01

    This study examines whether avoidance of negative memories results in intrusions as well as reduced memory specificity. Healthy participants suppressed memories of either a negative or a neutral autobiographical event. Individuals who suppressed negative memories tended to demonstrate smaller increa

  7. The negation bias: When negations signal stereotypic expectancies

    NARCIS (Netherlands)

    Beukeboom, C.J.; Finkenauer, C.; Wigboldus, D.H.J.

    2010-01-01

    Research on linguistic biases shows that stereotypic expectancies are implicitly reflected in language and are thereby subtly communicated to message recipients. We examined whether these findings extend to the use of negations (e.g., not smart instead of stupid). We hypothesized that people use mor

  8. Chinese Negative Transfer in Translation

    Institute of Scientific and Technical Information of China (English)

    王红琴

    2009-01-01

    The nat ive language can help learn a foreign language, but foreign language learners const ant ly suffer negat ivet ransfer from t heir mot her language. We,as Chinese English learners in t he environment ,in t he English-Chinese t ranslat ion inChinese is oft en negat ive impact .The present paper probes int o t he essence of language t ransfer ,making a det ailed comparisonbet ween Chinese and English vocabulary in t erms of concept ual meaning,connot at ive meaning and idioms in order t o find out t hebasic principle of t ranslat ion which may help avoid negat ive t ransfer from Chinese.

  9. Negative-Pressure Pulmonary Edema.

    Science.gov (United States)

    Bhattacharya, Mallar; Kallet, Richard H; Ware, Lorraine B; Matthay, Michael A

    2016-10-01

    Negative-pressure pulmonary edema (NPPE) or postobstructive pulmonary edema is a well-described cause of acute respiratory failure that occurs after intense inspiratory effort against an obstructed airway, usually from upper airway infection, tumor, or laryngospasm. Patients with NPPE generate very negative airway pressures, which augment transvascular fluid filtration and precipitate interstitial and alveolar edema. Pulmonary edema fluid collected from most patients with NPPE has a low protein concentration, suggesting hydrostatic forces as the primary mechanism for the pathogenesis of NPPE. Supportive care should be directed at relieving the upper airway obstruction by endotracheal intubation or cricothyroidotomy, institution of lung-protective positive-pressure ventilation, and diuresis unless the patient is in shock. Resolution of the pulmonary edema is usually rapid, in part because alveolar fluid clearance mechanisms are intact. In this review, we discuss the clinical presentation, pathophysiology, and management of negative-pressure or postobstructive pulmonary edema.

  10. Sigma Models with Negative Curvature

    CERN Document Server

    Alonso, Rodrigo; Manohar, Aneesh V.

    2016-01-01

    We construct Higgs Effective Field Theory (HEFT) based on the scalar manifold H^n, which is a hyperbolic space of constant negative curvature. The Lagrangian has a non-compact O(n,1) global symmetry group, but it gives a unitary theory as long as only a compact subgroup of the global symmetry is gauged. Whether the HEFT manifold has positive or negative curvature can be tested by measuring the S-parameter, and the cross sections for longitudinal gauge boson and Higgs boson scattering, since the curvature (including its sign) determines deviations from Standard Model values.

  11. Negative refractive index in chiral metamaterials.

    Science.gov (United States)

    Zhang, Shuang; Park, Yong-Shik; Li, Jensen; Lu, Xinchao; Zhang, Weili; Zhang, Xiang

    2009-01-16

    We experimentally demonstrate a chiral metamaterial exhibiting negative refractive index at terahertz frequencies. The presence of strong chirality in the terahertz metamaterial lifts the degeneracy for the two circularly polarized waves and allows for the achievement of negative refractive index without requiring simultaneously negative permittivity and negative permeability. The realization of terahertz chiral negative index metamaterials offers opportunities for investigation of their novel electromagnetic properties, such as negative refraction and negative reflection, as well as important terahertz device applications.

  12. Photonic crystal negative refractive optics.

    Science.gov (United States)

    Baba, Toshihiko; Abe, Hiroshi; Asatsuma, Tomohiko; Matsumoto, Takashi

    2010-03-01

    Photonic crystals (PCs) are multi-dimensional periodic gratings, in which the light propagation is dominated by Bragg diffraction that appears to be refraction at the flat surfaces of the PC. The refraction angle from positive to negative, perfectly or only partially obeying Snell's law, can be tailored using photonic band theory. The negative refraction enables novel prism, collimation, and lens effects. Because PCs usually consist of two transparent media, these effects occur at absorption-free frequencies, affording significant design flexibility for free-space optics. The PC slab, a high-index membrane with a two-dimensional airhole array, must be carefully designed to avoid reflection and diffraction losses. Light focusing based on negative refraction forms a parallel image of a light source, facilitating optical couplers and condenser lenses for wavelength demultiplexing. A compact wavelength demultiplexer can be designed by combining the prism and lens effects. The collimation effect is obtainable not only inside but also outside of the PC by optimizing negative refractive condition.

  13. Questioning Zero and Negative Numbers

    Science.gov (United States)

    Wilcox, Virginia B.

    2008-01-01

    After experiencing a Developing Mathematical Ideas (DMI) class on the construction of algebraic concepts surrounding zero and negative numbers, the author conducted an interview with a first grader to determine the youngster's existing level of understanding about these topics. Uncovering young students' existing understanding can provide focus…

  14. A Semantic Analysis of Negative Concord

    NARCIS (Netherlands)

    Wouden van der, Ton; Zwarts, Frans

    1993-01-01

    It is not uncommon in natural languages that negation seems to behave in an illogical manner. The general term for the many cases where multiple occurrences of morphologically negative constituents express a single semantic negation is negative concord (Labov 1979). Negative concord may take either

  15. Negative refraction angular characterization in one-dimensional photonic crystals.

    Directory of Open Access Journals (Sweden)

    Jesus Eduardo Lugo

    Full Text Available BACKGROUND: Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. METHODOLOGY/PRINCIPAL FINDINGS: By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. CONCLUSIONS/SIGNIFICANCE: Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

  16. Perisylvian functional connectivity during processing of sentential negation

    Directory of Open Access Journals (Sweden)

    Jörg eBahlmann

    2011-05-01

    Full Text Available Every language has the means to reverse the truth value of a sentence by using specific linguistic markers of negation. In the present study we investigated the neural processing costs afforded by the construction of meaning in German sentences containing negation in different clause types. We studied negations within and across clause boundaries as well as single and double negations. Participants read German sentences comprising of affirmations, single negations in the main or in the subordinate clause, or double negations. As a result, we found a network including the left inferior frontal gyrus (pars triangularis, BA 45, and the left inferior parietal gyrus (BA 40 to be activated whenever negations in the main clause had to be processed. Additionally, we found increased functional coupling between the left pars triangularis (BA 45, left pars opercularis (BA 44, left SMA (BA 6, and left superior temporal gyrus (BA 42 during the processing of main clause negations. The study shows that in order to process negations that require semantic integration across clause boundaries left BA 45 interplays with other areas that have been related to language processing and/or the processing of cognitive demands and logical/conditional reasoning. Thus, the results indicate that the left perisylvian language network synchronizes in order to resolve negations, in particular, whenever requirements on meaning integration are enhanced.

  17. Magnetic levitation from negative permeability materials

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, Mark W., E-mail: mcoffey@mines.edu [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States)

    2012-09-03

    As left-handed materials and metamaterials are becoming more prevalent, we examine the effect of negative permeability upon levitation force. We first consider two half spaces of differing permeability and a point magnetic source, so that the method of images may be employed. We determine that the resulting force may be larger than for conventional magnetic materials. We then illustrate the inclusion of a finite sample thickness. -- Highlights: ► The effect of negative permeability upon levitation force is considered. ► Such an effect could be realized with metamaterials. ► The resulting force may be larger than with conventional materials. ► The analysis is extended to allow for a finite sample thickness. ► Representative numerical values are given.

  18. Human choice under schedules of negative reinforcement.

    Science.gov (United States)

    Alessandri, Jérôme; Cançado, Carlos R X

    2015-12-01

    The generalized matching equation provides a good description of response allocation in concurrent schedules of positive reinforcement in nonhumans as well as in humans. The present experiment was conducted to further investigate the allocation of responding under concurrent schedules of negative reinforcement (i.e., timeouts from pressing a force cell) in humans. Each of three participants was exposed to different reinforcement ratios (9:1, 1:1 and 1:9) in the terminal links of a concurrent-chains schedule of negative reinforcement. The allocation of responding under this schedule was well described by the generalized matching equation, for each participant. These results replicate previous findings obtained with nonhumans and humans under concurrent schedules of positive reinforcement. In addition, they extend the results reported by Alessandri and Rivière (2013) showing that human behavior maintained by timeouts from an effortful response is sensitive to changes in relative reinforcement ratios as well as relative delays of reinforcement.

  19. Uniform Refraction in Negative Refractive Index Materials

    CERN Document Server

    Gutierrez, Cristian E

    2015-01-01

    We study the problem of constructing an optical surface separating two homogeneous, isotropic media, one of which has a negative refractive index. In doing so, we develop a vector form of Snell's law, which is used to study surfaces possessing a certain uniform refraction property, both in the near and far field cases. In the near field problem, unlike the case when both materials have positive refractive index, we show that the resulting surfaces can be neither convex nor concave.

  20. Uniform refraction in negative refractive index materials.

    Science.gov (United States)

    Gutiérrez, Cristian E; Stachura, Eric

    2015-11-01

    We study the problem of constructing an optical surface separating two homogeneous, isotropic media, one of which has a negative refractive index. In doing so, we develop a vector form of Snell's law, which is used to study surfaces possessing a certain uniform refraction property, in both the near- and far-field cases. In the near-field problem, unlike the case when both materials have positive refractive indices, we show that the resulting surfaces can be neither convex nor concave.

  1. Negative Point Mass Singularities in General Relativity

    CERN Document Server

    Robbins, Nicholas

    2010-01-01

    First we review the definition of a negative point mass singularity. Then we examine the gravitational lensing effects of these singularities in isolation and with shear and convergence from continuous matter. We review the Inverse Mean Curvature Flow and use this flow to prove some new results about the mass of a singularity, the ADM mass of the manifold, and the capacity of the singularity. We describe some particular examples of these singularities that exhibit additional symmetries.

  2. Negative marginal tax rates and heterogeneity

    OpenAIRE

    Choné, Philippe; Laroque, Guy

    2009-01-01

    Heterogeneity is likely to be an important determinant of the shape of optimal tax schemes. This article addresses the issue in a model à la Mirrlees with a continuum of agents. The agents differ in their productivities and opportunity costs of work, but their labor supplies depend only on a unidimensional combination of their two characteristics. Conditions are given under which the standard result that marginal tax rates are everywhere non-negative holds. This is in particular the case when...

  3. The impact of parental behaviors on children's negative emotions

    OpenAIRE

    Tong, Sijia

    2015-01-01

    The study examined the role of different parental behaviors on children’s negative emotions. Parents of 152 Finnish first grade children (79 girls and 73 boys) filled in diary-formed questionnaires which measure parental behaviors including affection, behavioral control and psychological control. Children’s negative emotions are also measured by diary-formed questionnaires which are filled in by their parents. The results showed that parental affection was negatively related to children’s neg...

  4. Learning processes underlying avoidance of negative outcomes.

    Science.gov (United States)

    Andreatta, Marta; Michelmann, Sebastian; Pauli, Paul; Hewig, Johannes

    2017-04-01

    Successful avoidance of a threatening event may negatively reinforce the behavior due to activation of brain structures involved in reward processing. Here, we further investigated the learning-related properties of avoidance using feedback-related negativity (FRN). The FRN is modulated by violations of an intended outcome (prediction error, PE), that is, the bigger the difference between intended and actual outcome, the larger the FRN amplitude is. Twenty-eight participants underwent an operant conditioning paradigm, in which a behavior (button press) allowed them to avoid a painful electric shock. During two learning blocks, participants could avoid an electric shock in 80% of the trials by pressing one button (avoidance button), or by not pressing another button (punishment button). After learning, participants underwent two test blocks, which were identical to the learning ones except that no shocks were delivered. Participants pressed the avoidance button more often than the punishment button. Importantly, response frequency increased throughout the learning blocks but it did not decrease during the test blocks, indicating impaired extinction and/or habit formation. In line with a PE account, FRN amplitude to negative feedback after correct responses (i.e., unexpected punishment) was significantly larger than to positive feedback (i.e., expected omission of punishment), and it increased throughout the blocks. Highly anxious individuals showed equal FRN amplitudes to negative and positive feedback, suggesting impaired discrimination. These results confirm the role of negative reinforcement in motivating behavior and learning, and reveal important differences between high and low anxious individuals in the processing of prediction errors.

  5. Negative spiral CT in acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, T.; Olausson, A. [Karolinska Hospital, Stockholm (Sweden). Dept. of Thoracic Radiology; Johnsson, H. [Karolinska Hospital, Stockholm (Sweden). Dept. of Internal Medicine; Nyman, U. [County Hospital, Trelleborg (Sweden). Dept. of Radiology; Aspelin, P. [Huddinge Univ. Hospital (Sweden). Dept. of Radiology

    2002-09-01

    Purpose: To retrospectively evaluate the clinical outcome of non-anticoagulated patients with clinically suspected acute pulmonary embolism (PE) and no symptoms or signs of deep venous thrombosis (DVT) following a negative contrast medium-enhanced spiral CT of the pulmonary arteries (s-CTPA). Material and Methods: During a 24-month period, 739 of 751 patients underwent s-CTPA with acceptable diagnostic quality for clinically suspected acute PE. All patients who had a CT study not positive for PE were followed up with a questionnaire, a telephone interview and review of all medical reports, including autopsies and death certificates for any episodes of venous thromboembolism (VTE) during a 3-month period. Results: PE was diagnosed in 158 patients. Of the remaining 581 patients with a negative s-CTPA, 45 patients were lost to follow-up. 88 patients were excluded because of anticoagulation treatment (cardiac disorder n=32, chronic VTE or acute symptomatic DVT n=31, PE diagnosed at pulmonary angiography n=1, thrombus prophylaxis during diagnostic work-up or other reasons than VTE n=24) and 7 patients undergoing lower extremity venous studies because of symptoms of DVT (all negative). Thus, 441 patients with a negative s-CTPA and no DVT symptoms, venous studies or anticoagulant treatment constituted the follow-up cohort. Four of these patients had proven VTE (all PE) during the 3-month follow-up period. Two of the PE episodes contributed to the patient's death. Conclusion: Patients with clinically suspected acute PE, no symptoms or signs of DVT and a negative single slice s-CTPA using 3-5 mm collimation, may safely be left without anticoagulation treatment unless they are critically ill, have a limited cardiopulmonary reserve and/or if a high clinical suspicion remains.

  6. Cosmology with Negative Absolute Temperatures

    CERN Document Server

    Vieira, J P P; Lewis, Antony

    2016-01-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al (2013) has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion ($w<-1$) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  7. Cosmology with negative absolute temperatures

    Science.gov (United States)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  8. Proclus’ View about Negative Theology

    Directory of Open Access Journals (Sweden)

    S Rahimiyan

    2012-09-01

    Full Text Available Negative theology is a modern theological approach that idiomatically implies those theological doctrines which are based on the negative premises and concepts for describing God. Among Greeks, this approach was on its climax in Neo-Platonism. Proclus is one of the Neo-Platonists who lived in fifth century (A.D and was in charge of Athena academy for years. He was the most important Neo-Platonist after Plotinus. In his philosophical system, on the one hand, it is impossible to recognize the first source and, on the other hand, the existence of some principles like the relationship between the creator and the universe, reversion and the way of emanation receiving, requires the knowledge of the first source. It seems that such paradox can be resolved by separating the stages of existence order.

  9. Gram-Negative Flagella Glycosylation

    Directory of Open Access Journals (Sweden)

    Susana Merino

    2014-02-01

    Full Text Available Protein glycosylation had been considered as an eccentricity of a few bacteria. However, through advances in analytical methods and genome sequencing, it is now established that bacteria possess both N-linked and O-linked glycosylation pathways. Both glycosylation pathways can modify multiple proteins, flagellins from Archaea and Eubacteria being one of these. Flagella O-glycosylation has been demonstrated in many polar flagellins from Gram-negative bacteria and in only the Gram-positive genera Clostridium and Listeria. Furthermore, O-glycosylation has also been demonstrated in a limited number of lateral flagellins. In this work, we revised the current advances in flagellar glycosylation from Gram-negative bacteria, focusing on the structural diversity of glycans, the O-linked pathway and the biological function of flagella glycosylation.

  10. Negation switching invariant signed graphs

    Directory of Open Access Journals (Sweden)

    Deepa Sinha

    2014-04-01

    Full Text Available A signed graph (or, $sigraph$ in short is a graph G in which each edge x carries a value $\\sigma(x \\in \\{-, +\\}$ called its sign. Given a sigraph S, the negation $\\eta(S$ of the sigraph S is a sigraph obtained from S by reversing the sign of every edge of S. Two sigraphs $S_{1}$ and $S_{2}$ on the same underlying graph are switching equivalent if it is possible to assign signs `+' (`plus' or `-' (`minus' to vertices of $S_{1}$ such that by reversing the sign of each of its edges that has received opposite signs at its ends, one obtains $S_{2}$. In this paper, we characterize sigraphs which are negation switching invariant and also see for what sigraphs, S and $\\eta (S$ are signed isomorphic.

  11. Negative effects of positive reinforcement.

    Science.gov (United States)

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive-those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say the distinction is untenable). When the distinction is made purely in operational terms, experiments reveal that positive reinforcement has aversive functions. On a practical level, positive reinforcement can lead to deleterious effects, and it is implicated in a range of personal and societal problems. These issues challenge us to identify other criteria for judging behavioral procedures.

  12. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Birke-Sorensen, Hanne; Kruse, Marie;

    Aim: Postoperative wound complications make many surgical procedures unnecessarily complex, particularly in high-risk patients. Negative Pressure Wound Therapy is well recognized in the management of open wounds. In recent years, it has been introduced as well in the management of closed surgical...... incisions to reduce postoperative wound complications, though the evidence base to support this intervention is limited. The aim of this study was to assess if Negative Pressure Wound Therapy (NPWT) reduces postoperative complications when applied on closed surgical incisions. Method: A systematic review...... formation (52%) compared to standard care. The reduction in wound dehiscence was not statistically significant. The numbers needed to treat were 3 (seroma), 17 (dehiscence), and 25 (infection). Methodical heterogeneity across studies led to downgrading quality of evidence to moderate for infection...

  13. 3a-Negative Yersinia Pestis, China

    Directory of Open Access Journals (Sweden)

    Zhizhen Qi

    2015-12-01

    Full Text Available Dear Editor, As the causative agent of plague, Yersinia pestis has killed millions of people in the three major historical pandemics and remains endemic in many natural foci around the world today. This Gram-negative bacterium is transmitted to humans and susceptible animals from the natural rodent reservoirs through the bites of infected fleas, contact with infected animals or persons, or aerosols. Because of its respiratory transmission and high pathogenicity, the potential use of Y. pestis as a bioterrorism agent is a major concern. The specific and rapid detection of Y. pestis is the key step in implementing effective countermeasures during plague epidemics. The standard culture and biochemical identification methods for Y. pestis are relatively time-consuming, so PCR assays are frequently used because they are rapid. However, the amplification targets are usually based on three plasmids, which may be lost in atypical strains, causing false-negative results. Therefore, Radnedge et al. identified a signature sequence, designated “3a”, in a chromosomal region of Y. pestis, based on the results of suppression subtractive hybridization, which was later confirmed with a microarray-based analysis. A positive 3a result has been shown to be an effective marker for the identification of Y. pestis isolates. However, the recent isolation of 3a-negative Y. pestis in China suggests that this indicator is unreliable.

  14. Quantum Complexity and Negative Curvature

    CERN Document Server

    Brown, Adam R; Zhao, Ying

    2016-01-01

    As time passes, once simple quantum states tend to become more complex. For strongly coupled k-local Hamiltonians, this growth of computational complexity has been conjectured to follow a distinctive and universal pattern. In this paper we show that the same pattern is exhibited by a much simpler system: classical geodesics on a compact two-dimensional geometry of uniform negative curvature. This striking parallel persists whether the system is allowed to evolve naturally or is perturbed from the outside.

  15. Research priorities for negative emissions

    Science.gov (United States)

    Fuss, S.; Jones, C. D.; Kraxner, F.; Peters, G. P.; Smith, P.; Tavoni, M.; van Vuuren, D. P.; Canadell, J. G.; Jackson, R. B.; Milne, J.; Moreira, J. R.; Nakicenovic, N.; Sharifi, A.; Yamagata, Y.

    2016-11-01

    Carbon dioxide removal from the atmosphere (CDR)—also known as ‘negative emissions’—features prominently in most 2 °C scenarios and has been under increased scrutiny by scientists, citizens, and policymakers. Critics argue that ‘negative emission technologies’ (NETs) are insufficiently mature to rely on them for climate stabilization. Some even argue that 2 °C is no longer feasible or might have unacceptable social and environmental costs. Nonetheless, the Paris Agreement endorsed an aspirational goal of limiting global warming to even lower levels, arguing that climate impacts—especially for vulnerable nations such as small island states—will be unacceptably severe in a 2 °C world. While there are few pathways to 2 °C that do not rely on negative emissions, 1.5 °C scenarios are barely conceivable without them. Building on previous assessments of NETs, we identify some urgent research needs to provide a more complete picture for reaching ambitious climate targets, and the role that NETs can play in reaching them.

  16. Persistent Negative Symptoms in Schizophrenia: An Overview

    OpenAIRE

    Buchanan, Robert W.

    2006-01-01

    Persistent negative symptoms represent an alternative approach for assessing negative symptoms in the context of clinical trials. Persistent negative symptoms are designed to capture those symptoms that lead to functional impairment but are currently understudied and for which there are no currently available effective treatments. Persistent negative symptoms differ from the 2 most commonly used approaches: primary, enduring negative symptoms or deficit symptoms and negative symptoms broadly ...

  17. Bayesian network model of crowd emotion and negative behavior

    Science.gov (United States)

    Ramli, Nurulhuda; Ghani, Noraida Abdul; Hatta, Zulkarnain Ahmad; Hashim, Intan Hashimah Mohd; Sulong, Jasni; Mahudin, Nor Diana Mohd; Rahman, Shukran Abd; Saad, Zarina Mat

    2014-12-01

    The effects of overcrowding have become a major concern for event organizers. One aspect of this concern has been the idea that overcrowding can enhance the occurrence of serious incidents during events. As one of the largest Muslim religious gathering attended by pilgrims from all over the world, Hajj has become extremely overcrowded with many incidents being reported. The purpose of this study is to analyze the nature of human emotion and negative behavior resulting from overcrowding during Hajj events from data gathered in Malaysian Hajj Experience Survey in 2013. The sample comprised of 147 Malaysian pilgrims (70 males and 77 females). Utilizing a probabilistic model called Bayesian network, this paper models the dependence structure between different emotions and negative behaviors of pilgrims in the crowd. The model included the following variables of emotion: negative, negative comfortable, positive, positive comfortable and positive spiritual and variables of negative behaviors; aggressive and hazardous acts. The study demonstrated that emotions of negative, negative comfortable, positive spiritual and positive emotion have a direct influence on aggressive behavior whereas emotion of negative comfortable, positive spiritual and positive have a direct influence on hazardous acts behavior. The sensitivity analysis showed that a low level of negative and negative comfortable emotions leads to a lower level of aggressive and hazardous behavior. Findings of the study can be further improved to identify the exact cause and risk factors of crowd-related incidents in preventing crowd disasters during the mass gathering events.

  18. Oligoclonal IgG bands in the cerebrospinal fluid of portuguese patients with multiple sclerosis: negative results indicate benign disease Bandas oligoclonais da IgG no líquido céfalo-raquidiano de doentes portugueses com esclerose múltipla: resultados negativos indicam doença benigna

    Directory of Open Access Journals (Sweden)

    Maria José Sá

    2005-06-01

    Full Text Available We assessed the frequency of cerebrospinal fluid (CSF restricted oligoclonal IgG bands (IgG-OCB in Portuguese multiple sclerosis (MS patients and its relationship with outcome. Paired CSF/serum samples of 406 patients with neurological disorders were submitted to isoelectric focusing with immunodetection of IgG. Ninety-two patients had definite MS; non-MS cases were assembled in groups inflammatory/infectious diseases (ID, n=141 and other/controls (OD, n=173. We found in the MS group: mean duration, 38.9 months; clinically isolated syndromes, 24%; relapsing/remitting course (RR, 65%; in RR patients the mean EDSS was 2.1 and the mean index of progression was 0.31. Positive patterns significantly predominated in MS (82.6%; ID, 40.4%; OD, 3.5%. The sensitivity and the specificity of positive IgG-OCB for MS diagnosis was 82.6% and 79.9%, respectively. The sole statistically significant difference in the MS group was the lower progression index observed in negative cases. We conclude that the frequency of positive IgG-OCB patterns in our MS patients fits most values reported in the literature, and that negative results indicate benign disease.Analisamos a frequência de bandas oligoclonais (BOC restritas ao líquido céfalo-raquidiano (LCR em doentes portugueses com esclerose múltipla (EM e sua relação com a clínica. Determinaram-se por focagem isoeléctrica e imunodetecção as BOC da IgG em pares de amostras LCR/soro de 406 doentes com diversas patologias neurológicas: 92 tinham EM definitiva; os casos "não-EM" agruparam-se em doenças inflamatórias/infecciosas (ID; n=141 e outras/controles (OD; n=173. O grupo EM apresentava duração média: 38,9 meses; síndromes clinicamente isolados (CIS, 24%; formas surto/remissão (RR, 65%, nas quais se encontrou EDSS e índice de progressão médios de 2,1 e 0,31, respectivamente. O perfil positivo predominava significativamente na EM (82,6%; ID, 40,4%; OD, 3,5%, cuja sensibilidade e especificidade

  19. BRCA1/2-negative hereditary triple-negative breast cancers exhibit BRCAness.

    Science.gov (United States)

    Domagala, Pawel; Hybiak, Jolanta; Cybulski, Cezary; Lubinski, Jan

    2017-04-01

    BRCA1/2-associated breast cancers are sensitive to poly(ADPribose) polymerase (PARP) inhibitors and platinum compounds mainly due to their deficiency in DNA repair via homologous recombination (HR). However, approximately only 15% of triple-negative breast cancers (TNBCs) are BRCA1/2-associated. TNBCs that exhibit BRCAness (a phenotype reflecting impaired HR in BRCA1/2-negative tumors) are also regarded sensitive to PARP inhibitors and platinum compounds. Thus, we hypothesized that hereditary BRCA1/2-negative TNBCs may exhibit BRCAness. To find a subset of hereditary BRCA1/2-negative TNBCs among 360 TNBCs, we first identified a group of 41 hereditary TNBCs by analyzing the family histories of the patients. Next, we tested this group for the presence of germline BRCA1/2 mutations, and finally, we compared the expression levels of 120 genes involved in HR and five other major mechanisms of DNA damage repair between BRCA1/2-associated and BRCA1/2-negative subgroups of hereditary TNBCs using real-time PCR arrays. Approximately 73% of the hereditary TNBCs were BRCA1/2-associated and 27% were BRCA1/2-negative. The expression levels of the analyzed genes showed no significant differences between these two subgroups indicating the BRCAness of the BRCA1/2-negative hereditary TNBCs and thereby distinguishing a novel subset of TNBCs as a potential target for PARP inhibitors or platinum-based therapy. The results show the significance of family history in selecting patients with TNBC for therapies directed at incompetent DNA repair (e.g., PARP inhibitors and/or platinum-based therapies) and indicate that a relatively simple strategy for broadening the target group for these modes of treatment is to identify patients with hereditary TNBCs.

  20. Negative refractive index metamaterials aided by extraordinary optical transmission.

    Science.gov (United States)

    García-Meca, C; Ortuño, R; Rodríguez-Fortuño, F J; Martí, J; Martínez, A

    2009-04-13

    We study under which conditions extraordinary optical transmission (EOT) structures can be used to build negative refractive index media. As a result, we present a metamaterial with superimposed EOT and negative index at visible wavelengths. The tailoring process starting from a simple hole array until achieving the negative index is detailed. We also discuss the so-called fishnet metamaterial (previously linked to EOT) under the same prism. Using the ideas put forward in this work, other structures with negative index could be engineered in the optical or visible spectrum.

  1. Ray-tracing optical modeling of negative dysphotopsia

    Science.gov (United States)

    Hong, Xin; Liu, Yueai; Karakelle, Mutlu; Masket, Samuel; Fram, Nicole R.

    2011-12-01

    Negative dysphotopsia is a relatively common photic phenomenon that may occur after implantation of an intraocular lens. The etiology of negative dysphotopsia is not fully understood. In this investigation, optical modeling was developed using nonsequential-component Zemax ray-tracing technology to simulate photic phenomena experienced by the human eye. The simulation investigated the effects of pupil size, capsulorrhexis size, and bag diffusiveness. Results demonstrated the optical basis of negative dysphotopsia. We found that photic structures were mainly influenced by critical factors such as the capsulorrhexis size and the optical diffusiveness of the capsular bag. The simulations suggested the hypothesis that the anterior capsulorrhexis interacting with intraocular lens could induce negative dysphotopsia.

  2. Negative Correlations and Entanglement in Higher-Spin Dicke States

    Science.gov (United States)

    Wang, Xiaoqian; Zhong, Wei; Wang, Xiaoguang

    2016-10-01

    We consider entanglement criteria based on the spin squeezing inequalities for arbitrary spin systems. Here we use the negative correlations to detect the entanglement in the system with exchange symmetry. For arbitrary spin systems, we can find that the state is entangled, when the minimal pairwise correlation is negative. Then we give a parameter which is defined by the collective angular momentum operator, to detect the entanglement for the Dicke state with N spin -1 particles, and the results are as the same as negative correlation. We also consider the directions of negative correlation, the state is entangled in two orthogonal directions for the superposition of Dicke state without parity.

  3. Electromagnetic field energy density in homogeneous negative index materials.

    Science.gov (United States)

    Shivanand; Webb, Kevin J

    2012-05-07

    An exact separation of both electric and magnetic energies into stored and lost energies is shown to be possible in the special case when the wave impedance is independent of frequency. A general expression for the electromagnetic energy density in such a dispersive medium having a negative refractive index is shown to be accurate in comparison with numerical results. Using an example metamaterial response that provides a negative refractive index, it is shown that negative time-averaged stored energy can occur. The physical meaning of this negative energy is explained as the energy temporarily borrowed by the field from the material. This observation for negative index materials is of interest when approaching properties for a perfect lens. In the broader context, the observation of negative stored energy is of consequence in the study of dispersive materials.

  4. Negative ion studies on the RF plasma device MAGPIE

    Science.gov (United States)

    Willett, Hannah; Santoso, Jesse; Corr, Cormac; Gibson, Kieran

    2016-10-01

    Neutral beam injection (NBI) systems provide both heating and current drive in tokamak fusion reactors. High energy (> 1 MeV) neutral beams are produced by neutralising accelerated ions, for which negative ions are used; the neutralisation cross section for positive ions becomes negligible at these energies. This requires very high throughput negative ion sources. Currently this is achieved using inductively coupled plasma sources, which incorporate caesium to improve the production rate. It has been proposed that helicon plasma sources could provide a more efficient, higher throughput method of producing negative ions for NBI, possibly even removing the need for caesium. We report on studies of the negative hydrogen ion population in the MAGPIE helicon device (Australian National University) under a variety of operating conditions. The probe-based laser photodetachment method and Langmuir probes are employed to estimate the negative hydrogen ion density throughout the device. Initial results support the viability of helicon-based negative ion sources.

  5. Nanocharacterization of the negative stiffness of ferroelectric materials

    Science.gov (United States)

    Alipour Skandani, A.; Ctvrtlik, R.; Al-Haik, M.

    2014-08-01

    Phase changing materials such as ferroelectric materials could exhibit negative stiffness under certain thermomechanical environments. This negative stiffness is embodied by a deflection along the opposite direction of the applied load. So far negative stiffness materials were investigated with the specific morphology of embedded inclusions in stiff matrices then the resulting composite is studied to measure the behavior of each constituent indirectly. In this study, a modified nonisothermal nanoindentation method is developed to measure the negative stiffness of triglycine sulfate single crystal directly. This in-situ method is intended to first demonstrate the feasibility of detecting the negative stiffness via nanoindentation and nanocreep of a ferroelectric material at its Curie point and then to quantify the negative stiffness without the need for embedding the crystal within a stiffer matrix.

  6. Frequency Dependent Negative Resistance-A review

    Directory of Open Access Journals (Sweden)

    D.Susan

    2012-08-01

    Full Text Available Inductors are bulky and costly but reducing the size of the inductors reduces the quality factor. There is also a fundamental limitation of using inductor that it cannot be suitable for the micro miniature structure and integrated circuits applications. Because of these limitations, inductors cannot be used in most of the analog circuit applications. Hence simulated inductors are used as an alternative. In case the simulated inductor becomes floating some linear transformation is used which results in the formation of a new D element called the Frequency Dependent Negative Resistance (FDNR. This paper presents an overview of the basic circuits of simulating the Frequency Dependent Negative Resistance and its various applications in analog circuits in the place of floating inductor.

  7. Can Bold Typeface Improve Readers' Comprehension and Metacomprehension of Negation?

    Science.gov (United States)

    Margolin, Sara J.

    2013-01-01

    Recent research on negation has demonstrated that while readers are aware that this text construction is difficult, they seem to be able to do little to improve their comprehension. The present research evaluated whether a change in typeface could improve comprehension and metacomprehension of negation. Results indicated that while readers were…

  8. On complete moment convergence for nonstationary negatively associated random variables

    Directory of Open Access Journals (Sweden)

    Mi-Hwa Ko

    2016-05-01

    Full Text Available Abstract The purpose of this paper is to establish the complete moment convergence for nonstationary negatively associated random variables satisfying the weak mean domination condition. The result is an improvement of complete convergence in Marcinkiewicz-Zygmund-type SLLN for negatively associated random variables in Kuczmaszewska (Acta Math. Hung. 128:116-130, 2010.

  9. 19 CFR 10.618 - Issuance of negative origin determinations.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Issuance of negative origin determinations. 10.618... Issuance of negative origin determinations. If, as a result of an origin verification initiated under this... subject of the verification together with the identifying numbers and dates of the import...

  10. [Negative pressure wound therapy dressings].

    Science.gov (United States)

    Téot, Luc

    2016-01-01

    There are many different forms of negative pressure wound therapy dressings and it is important to distinguish clearly between each type. They enable the treatment to be adapted to the shape and depth of the wound, its degree of exudation and the persistence of the fibrinous areas on the surface. The machine's traction capacity, measured in mm of mercury (Hg), must be controlled to establish the healing profile: the more powerful the machine and the more contact there is between the foam and the wound, the faster the formation of the granulation tissue. There are many different solutions which are implemented in accordance with the clinical assessment of the wound.

  11. Superluminal travel requires negative energies

    OpenAIRE

    Olum, Ken D.

    1998-01-01

    I investigate the relationship between faster-than-light travel and weak-energy-condition violation, i.e., negative energy densities. In a general spacetime it is difficult to define faster-than-light travel, and I give an example of a metric which appears to allow superluminal travel, but in fact is just flat space. To avoid such difficulties, I propose a definition of superluminal travel which requires that the path to be traveled reach a destination surface at an earlier time than any neig...

  12. Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Davis, V.T. [Test Support Division, Defense Threat Reduction Agency, West Desert Test Center, Dugway, UT 84022-5000 (United States)]. E-mail: vernon.davis@us.army.mil; Covington, A.M. [Department of Physics, University of Nevada, MS 220, Reno, NV 89557-0058 (United States); Duvvuri, S.S. [Department of Physics, University of Nevada, MS 220, Reno, NV 89557-0058 (United States); Kraus, R.G. [Department of Physics, University of Nevada, MS 220, Reno, NV 89557-0058 (United States); Emmons, E.D. [Department of Physics, University of Nevada, MS 220, Reno, NV 89557-0058 (United States); Kvale, T.J. [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States); Thompson, J.S. [Department of Physics, University of Nevada, MS 220, Reno, NV 89557-0058 (United States)

    2007-08-15

    The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps.

  13. The effect of negative experiences on delinquent behavior of youth in a social withdrawal situation.

    Science.gov (United States)

    Chan, Gloria Hongyee; Lo, T Wing

    2016-07-01

    This study examines the relationship between negative experiences, negative emotions, and delinquent behavior among young people in a social withdrawal situation. There were 533 participants in this study and various quantitative analyses were utilized. Results showed that participants with a longer period of social withdrawal were generally less affected by negative experiences, while those with a higher level of social withdrawal were more affected by negative experiences, particularly negative relationships with other people. Also, both negative emotions and higher level of social withdrawal mediated the relationship between negative experiences and involvement in delinquent behavior, with negative emotions displaying a higher mediating effect. This reflects that the root of delinquent behavior is the negative experiences which arouse negative emotions, rather than the social withdrawal behavior itself. Results imply that practitioners should first explore the negative experiences suffered by these young people, so as to provide them the most appropriate support.

  14. The developmental origins of cognitive vulnerability to depression: temperament, parenting, and negative life events in childhood as contributors to negative cognitive style.

    Science.gov (United States)

    Mezulis, Amy H; Hyde, Janet Shibley; Abramson, Lyn Y

    2006-11-01

    Cognitive models of depression have been well supported with adults, but the developmental origins of cognitive vulnerability are not well understood. The authors hypothesized that temperament, parenting, and negative life events in childhood would contribute to the development of cognitive style, with withdrawal negativity and negative parental feedback moderating the effects of negative life events to predict more depressogenic cognitive styles. These constructs were assessed in 289 children and their parents followed longitudinally from infancy to 5th grade; a subsample (n = 120) also participated in a behavioral task in which maternal feedback to child failure was observed. Results indicated that greater withdrawal negativity in interaction with negative life events was associated with more negative cognitive styles. Self-reported maternal anger expression and observed negative maternal feedback to child's failure significantly interacted with child's negative events to predict greater cognitive vulnerability. There was little evidence of paternal parenting predicting child negative cognitive style.

  15. Negative Halogen Ions for Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-01

    Over the past quarter century, advances in hydrogen negative ion sources have extended the usable range of hydrogen isotope neutral beams to energies suitable for large magnetically confined fusion devices. Recently, drawing upon this experience, negative halogen ions have been proposed as an alternative to positive ions for heavy ion fusion drivers in inertial confinement fusion, because electron accumulation would be prevented in negative ion beams, and if desired, the beams could be photo-detached to neutrals. This paper reports the results of an experiment comparing the current density and beam emittance of Cl+ and Cl- extracted from substantially ion-ion plasmas with that of Ar+ extracted from an ordinary electron-ion plasma, all using the same source, extractor, and emittance scanner. At similar discharge conditions, the Cl- current was typically 85 – 90% of the positive chlorine current, with an e-/ Cl- ratio as low as seven without grid magnets. The Cl- was as much as 76% of the Ar+ current from a discharge with the same RF drive. The minimum normalized beam emittance and inferred ion temperatures of Cl+, Cl-, and Ar+ were all similar, so the current density and optical quality of Cl- appear as suitable for heavy ion fusion driver applications as a positive noble gas ion of similar mass. Since F, I, and Br should all behave similarly in an ion source, they should also be suitable as driver beams.

  16. A computational approach to negative priming

    Science.gov (United States)

    Schrobsdorff, H.; Ihrke, M.; Kabisch, B.; Behrendt, J.; Hasselhorn, M.; Herrmann, J. Michael

    2007-09-01

    Priming is characterized by a sensitivity of reaction times to the sequence of stimuli in psychophysical experiments. The reduction of the reaction time observed in positive priming is well-known and experimentally understood (Scarborough et al., J. Exp. Psycholol: Hum. Percept. Perform., 3, pp. 1-17, 1977). Negative priming—the opposite effect—is experimentally less tangible (Fox, Psychonom. Bull. Rev., 2, pp. 145-173, 1995). The dependence on subtle parameter changes (such as response-stimulus interval) usually varies. The sensitivity of the negative priming effect bears great potential for applications in research in fields such as memory, selective attention, and ageing effects. We develop and analyse a computational realization, CISAM, of a recent psychological model for action decision making, the ISAM (Kabisch, PhD thesis, Friedrich-Schiller-Universitat, 2003), which is sensitive to priming conditions. With the dynamical systems approach of the CISAM, we show that a single adaptive threshold mechanism is sufficient to explain both positive and negative priming effects. This is achieved by comparing results obtained by the computational modelling with experimental data from our laboratory. The implementation provides a rich base from which testable predictions can be derived, e.g. with respect to hitherto untested stimulus combinations (e.g. single-object trials).

  17. Negative Stress Margins - Are They Real?

    Science.gov (United States)

    Raju, Ivatury S.; Lee, Darlene S.; Mohaghegh, Michael

    2011-01-01

    Advances in modeling and simulation, new finite element software, modeling engines and powerful computers are providing opportunities to interrogate designs in a very different manner and in a more detailed approach than ever before. Margins of safety are also often evaluated using local stresses for various design concepts and design parameters quickly once analysis models are defined and developed. This paper suggests that not all the negative margins of safety evaluated are real. The structural areas where negative margins are frequently encountered are often near stress concentrations, point loads and load discontinuities, near locations of stress singularities, in areas having large gradients but with insufficient mesh density, in areas with modeling issues and modeling errors, and in areas with connections and interfaces, in two-dimensional (2D) and three-dimensional (3D) transitions, bolts and bolt modeling, and boundary conditions. Now, more than ever, structural analysts need to examine and interrogate their analysis results and perform basic sanity checks to determine if these negative margins are real.

  18. Ultrarefraction and negative refraction in metamaterials

    Science.gov (United States)

    Maystre, Daniel R.; Enoch, Stefan; Tayeb, Gerard

    2004-07-01

    In the recent years, many experimental and theoretical achievements have shown that meta-materials can simulate homogeneous materials with optical index less than unity or even negative. For example, a dielectric photonic crystal, used at the edge of a band gap, can generate phenomena of ultra-refraction (positive index less than unity) or negative refraction (negative index). Some applications of these phenomena will be shown, specially the design of directive antenna in the microwaves region. More recently, experimental and theoretical studies have been published on left-handed materials. These materials, which have a permittivity and a permeability equal to -1, have been the subject of controversies about their alleged property of making perfect lenses. It will be shown that such a perfect lens cannot exist. However, this kind of meta-material could be used for making better lenses than the best classical ones, a fact which could explain some experimental results. The vital influence of the size of the elementary cell on the performance of the lens will be pointed out. Finally, it will be shown that surprisingly, a left-handed material can be interpreted as a means to go through the mirror, as Alice in the novel of Lewis Carrol...

  19. Negative Binomial-Lindley Distribution and Its Application

    Directory of Open Access Journals (Sweden)

    Hossein Zamani

    2010-01-01

    Full Text Available Problem statement: The modeling of claims count is one of the most important topics in actuarial theory and practice. Many attempts were implemented in expanding the classes of mixed and compound distributions, especially in the distribution of exponential family, resulting in a better fit on count data. In some cases, it is proven that mixed distributions, in particular mixed Poisson and mixed negative binomial, provided better fit compared to other distributions. Approach: In this study, we introduce a new mixed negative binomial distribution by mixing the distributions of negative binomial (r,p and Lindley (θ, where the reparameterization of p = exp(-λ is considered. Results: The closed form and the factorial moment of the new distribution, i.e., the negative binomial-Lindley distribution, are derived. In addition, the parameters estimation for negative binomial-Lindley via the method of moments (MME and the Maximum Likelihood Estimation (MLE are provided. Conclusion: The application of negative binomial-Lindley distribution is carried out on two samples of insurance data. Based on the results, it is shown that the negative binomial-Lindley provides a better fit compared to the Poisson and the negative binomial for count data where the probability at zero has a large value.

  20. Hyperbolic spaces are of strictly negative type

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Kokkendorff, Simon L.; Markvorsen, Steen

    2002-01-01

    We study finite metric spaces with elements picked from, and distances consistent with, ambient Riemannian manifolds. The concepts of negative type and strictly negative type are reviewed, and the conjecture that hyperbolic spaces are of strictly negative type is settled, in the affirmative....... The technique of the proof is subsequently applied to show that every compact manifold of negative type must have trivial fundamental group, and to obtain a necessary criterion for product manifolds to be of negative type....

  1. Mondialization: The negation of territory

    Directory of Open Access Journals (Sweden)

    Đorđević Dejan

    2007-01-01

    Full Text Available The main objective of this paper is to present some weaknesses and inconsistence of the mondialization/globalization concept, especially regarding obvious negation of territoriality as a principle and a crude reality of uneven spatial distribution of resources, wealth and population on global scale. The domination of the globalism and neo-liberalism in the spheres of economy, society, culture and even language leads toward greater differences, in such intensity that some authors describe it as a "clash of civilizations". Loosing territoriality means loosing "raison d’etre" of spatial planning. Some efforts to introduce participation as a planning solution for the beginning of the new century is actually a Trojan horse and a step in the wrong direction.

  2. Entanglement negativity in the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Sugumi [Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao (Spain); Laboratory for Quantum Gravity & Strings and Astrophysics, Cosmology & Gravity Center, Department of Mathematics & Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Shock, Jonathan P. [Laboratory for Quantum Gravity & Strings and Astrophysics, Cosmology & Gravity Center, Department of Mathematics & Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); National Institute for Theoretical Physics, Private Bag X1, Matieland, 7602 (South Africa); Soda, Jiro [Department of Physics, Kobe University, Kobe 657-8501 (Japan)

    2015-03-10

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  3. Negative Tree Reweighted Belief Propagation

    CERN Document Server

    Liu, Qiang

    2012-01-01

    We introduce a new class of lower bounds on the log partition function of a Markov random field which makes use of a reversed Jensen's inequality. In particular, our method approximates the intractable distribution using a linear combination of spanning trees with negative weights. This technique is a lower-bound counterpart to the tree-reweighted belief propagation algorithm, which uses a convex combination of spanning trees with positive weights to provide corresponding upper bounds. We develop algorithms to optimize and tighten the lower bounds over the non-convex set of valid parameter values. Our algorithm generalizes mean field approaches (including naive and structured mean field approximations), which it includes as a limiting case.

  4. Entanglement negativity in the multiverse

    CERN Document Server

    Kanno, Sugumi; Soda, Jiro

    2014-01-01

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  5. Entanglement negativity in the multiverse

    Science.gov (United States)

    Kanno, Sugumi; Shock, Jonathan P.; Soda, Jiro

    2015-03-01

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  6. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Vinter, Christina Anne; Bille, Camilla

    Background: Obese women undergoing caesarean section are at increased risk of surgical wound complications, which may lead to delayed recovery, pain, reduced quality of life, and increased health care cost. The aim of this study is to evaluate the effect of incisional Negative Pressure Wound...... generator are used to allocate the participants into one of two groups (iNPWT vs. standard dressing), stratified by centre and type of CS. The study is conducted at five public hospitals located in three regions of Denmark. Interim analyses will be preformed along the trial using the group sequential method....... The analyses will be performed when sample size reaches 179, 357, 535, 713, and 891, respectively. Population: women with a pre-gestational BMI ≥ 30 undergoing planned or emergency caesarean section. The iNPWT or standard dressings is applied immediately following operation. In the intervention group...

  7. Negative health care experiences of immigrant patients: a qualitative study

    Directory of Open Access Journals (Sweden)

    Stronks Karien

    2011-01-01

    Full Text Available Abstract Background Negative events are abusive, potentially dangerous or life-threatening health care events, as perceived by the patient. Patients' perceptions of negative events are regarded as a potentially important source of information about the quality of health care. We explored negative events in hospital care as perceived by immigrant patients. Methods Semi-structured individual and group interviews were conducted with respondents about negative experiences of health care. Interviews were transcribed and analyzed using a framework method. A total of 22 respondents representing 7 non-Dutch ethnic origins were interviewed; each respondent reported a negative event in hospital care or treatment. Results Respondents reported negative events in relation to: 1 inadequate information exchange with care providers; 2 different expectations between respondents and care providers about medical procedures; 3 experienced prejudicial behavior on the part of care providers. Conclusions We identified three key situations in which negative events were experienced by immigrant patients. Exploring negative events from the immigrant patient perspective offers important information to help improve health care. Our results indicate that care providers need to be trained in adequately exchanging information with the immigrant patient and finding out specific patient needs and perspectives on illness and treatment.

  8. Growing Networks with Positive and Negative Links

    Science.gov (United States)

    Dech, Corynne; Antwi, Shadrack; Shaw, Leah

    Scale-free networks grown via preferential attachment have been used to model real-world networks such as the Internet, citation networks, and social networks. Here we investigate signed scale-free networks where an edge represents a positive or negative connection. We present analytic results and simulation for a growing signed network model. We compare the signed network to an unsigned scale-free network. We discuss several options for preferential attachment in a signed network that could be further adapted to model the accumulation of links over time in real-world signed networks.

  9. Culture Negative Infective Endocarditits: a Changing Paradigm

    LENUS (Irish Health Repository)

    Daly, A

    2016-05-01

    Traditionally, the modified Duke\\'s criteria, based primarily on positive blood cultures, is used to diagnose Infective Endocarditis (IE). However, reports demonstrate that 31% of cases are diagnosed as Culture Negative Infective Endocarditis (CNIE)1. Consequently, empiric broad-spectrum antibiotics are prescribed to cover unidentified organisms and, as a result, antibiotic therapy may be compromised. Molecular diagnostic techniques aid with identifying causative organisms in cases of CNIE and we question if the increasing use of such technologies will change the local epidemiology of CNIE. We present the first case of Tropheryma whipplei Infective Endocarditis (TWIE) reported in Ireland.

  10. Single-resonator double-negative metamaterial

    Science.gov (United States)

    Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Johnson, William A.; Ihlefeld, Jon; Ginn, III, James C.; Clem, Paul G.; Sinclair, Michael B.

    2016-06-21

    Resonances can be tuned in dielectric resonators in order to construct single-resonator, negative-index metamaterials. For example, high-contrast inclusions in the form of metallic dipoles can be used to shift the first electric resonance down (in frequency) to the first magnetic resonance, or alternatively, air splits can be used to shift the first magnetic resonance up (in frequency) near the first electric resonance. Degenerate dielectric designs become especially useful in infrared- or visible-frequency applications where the resonator sizes associated with the lack of high-permittivity materials can become of sufficient size to enable propagation of higher-order lattice modes in the resulting medium.

  11. Entanglement negativity in quantum field theory.

    Science.gov (United States)

    Calabrese, Pasquale; Cardy, John; Tonni, Erik

    2012-09-28

    We develop a systematic method to extract the negativity in the ground state of a 1+1 dimensional relativistic quantum field theory, using a path integral formalism to construct the partial transpose ρ(A)(T(2) of the reduced density matrix of a subsystem [formula: see text], and introducing a replica approach to obtain its trace norm which gives the logarithmic negativity E=ln//ρ(A)(T(2))//. This is shown to reproduce standard results for a pure state. We then apply this method to conformal field theories, deriving the result E~(c/4)ln[ℓ(1)ℓ(2)/(ℓ(1)+ℓ(2))] for the case of two adjacent intervals of lengths ℓ(1), ℓ(2) in an infinite system, where c is the central charge. For two disjoint intervals it depends only on the harmonic ratio of the four end points and so is manifestly scale invariant. We check our findings against exact numerical results in the harmonic chain.

  12. EFFECTS OF MEDICAL DISPUTES ON INTERNET COMMUNICATIONS OF NEGATIVE EMOTIONS AND NEGATIVE ONLINE WORD-OF-MOUTH.

    Science.gov (United States)

    Lee, Yi-Chih; Wu, Wei-Li

    2015-08-01

    Emotions play an important role in human behavior. Negative emotions resulting from medical disputes are problems for medical personnel to solve but also have a significant impact on a hospital's reputation and people's trust in the hospital. One medical dispute case was chosen from an Internet news source to assess the correlation between people's negative emotions and negative online word-of-mouth. Convenience sampling was used in school faculties and university students who had shared their medical treatment experiences online were the research participants. A total of 221 Taiwanese participants volunteered (158 women, 63 men; ages: 26.7% under 19, 22.6% 20-29, 30.8% 30-39,19.9% over 40). Four negative emotions were measured using rating scales: uncertainty, anger, disappointment, and sadness. Four negative online word-of-mouth measures were: venting, advice search, helping receiver, and revenge. A modeled relationship was assessed by partial least square method (PLS). Then, people's positive emotions were further analyzed to assess changes after spreading negative word-of-mouth. The results showed that uncertainty had a positive effect on venting and advice search. People who felt anger or regret spread word-of-mouth in order to help the receiver. Disappointment may trigger the revenge behavior of negative word-of-mouth. Negative emotions could be relieved after engaging in the behavior of helping the receiver.

  13. Prejudice Masquerading as Praise: The Negative Echo of Positive Stereotypes.

    Science.gov (United States)

    Siy, John Oliver; Cheryan, Sapna

    2016-07-01

    Five studies demonstrate the powerful connection between being the target of a positive stereotype and expecting that one is also being ascribed negative stereotypes. In Study 1, women who heard a man state a positive stereotype were more likely to believe that he held negative stereotypes of them than women who heard no stereotype. Beliefs about being negatively stereotyped mediated the relationship between hearing a positive stereotype and believing that the stereotyper was prejudiced. Studies 2 to 4 extended these results to Asian Americans and accounted for alternative explanations (e.g., categorization threat). In Study 5, the same positive stereotype (e.g., good at math) was directed to Asian American men's racial or gender identity. Their perceptions about whether negative racial or gender stereotypes were being applied to them depended on the identity referenced by the positive stereotype. Positive stereotypes signal a latent negativity about one's group, thereby explaining why they can feel like prejudice.

  14. Autobiographical memories for negative and positive events in war contexts

    Directory of Open Access Journals (Sweden)

    Antonio L. Manzanero

    2015-01-01

    Full Text Available The aim of the present study was to examine the phenomenological qualities of self-reported negative and positive memories. The study was conducted in the Gaza Strip, Palestine, and a total of 134 autobiographical memories about negative and positive events were analyzed using a version of the Phenomenological Questionnaire for Autobiographical Memory (Manzanero & López, 2007. Participants were university students, 80 percent were women and 20 percent were men. Results showed that negative memories are more confused, more complex, and decay more over time than positive ones. In contrast, no differences were found between positive and negative memories on sensory information, spatial location, vividness, definition, accessibility, fragmentation, recall perspective, doubts about the accuracy of the memory, and how much participants recovered and talked about the event. High Dimensional Visualization (HDV graph revealed that there were individual differences between negative and positive memories but no consistent differences across participants.

  15. PT -symmetric spectral singularity and negative-frequency resonance

    Science.gov (United States)

    Pendharker, Sarang; Guo, Yu; Khosravi, Farhad; Jacob, Zubin

    2017-03-01

    Vacuum consists of a bath of balanced and symmetric positive- and negative-frequency fluctuations. Media in relative motion or accelerated observers can break this symmetry and preferentially amplify negative-frequency modes as in quantum Cherenkov radiation and Unruh radiation. Here, we show the existence of a universal negative-frequency-momentum mirror symmetry in the relativistic Lorentzian transformation for electromagnetic waves. We show the connection of our discovered symmetry to parity-time (PT ) symmetry in moving media and the resulting spectral singularity in vacuum fluctuation-related effects. We prove that this spectral singularity can occur in the case of two metallic plates in relative motion interacting through positive- and negative-frequency plasmonic fluctuations (negative-frequency resonance). Our work paves the way for understanding the role of PT -symmetric spectral singularities in amplifying fluctuations and motivates the search for PT symmetry in novel photonic systems.

  16. The Influence of Negative Surprise on Hedonic Adaptation

    Directory of Open Access Journals (Sweden)

    Ana Paula Kieling

    2016-01-01

    Full Text Available After some time using a product or service, the consumer tends to feel less pleasure with consumption. This reduction of pleasure is known as hedonic adaptation. One of the emotions that interfere in this process is surprise. Based on two experiments, we suggest that negative surprise – differently to positive – influences with the level of pleasure foreseen and experienced by the consumer. Study 1 analyzes the influence of negative (vs. positive surprise on the consumer’s post-purchase hedonic adaptation expectation. Results showed that negative surprise influences the intensity of adaptation, augmenting its strength. Study 2 verifies the influence of negative (vs positive surprise over hedonic adaptation. The findings suggested that negative surprise makes adaptation happen more intensively and faster as time goes by, which brings consequences to companies and consumers in the post-purchase process, such as satisfaction and loyalty.

  17. Physical effects of negative air ions in a wet sauna

    Science.gov (United States)

    Watanabe, I.; Noro, Hiroshi; Ohtsuka, Yoshinori; Mano, Yukio; Agishi, Yuko

    The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42° C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were singificantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna.

  18. A Weighted Likelihood Ratio of Two Related Negative Hypergeomeric Distributions

    Institute of Scientific and Technical Information of China (English)

    Titi Obilade

    2004-01-01

    In this paper we consider some related negative hypergeometric distributions arising from the problem of sampling without replacement from an urn containing balls of different colours and in different proportions but stopping only after some specifi number of balls of different colours have been obtained.With the aid of some simple recurrence relations and identities we obtain in the case of two colours the moments for the maximum negative hypergeometric distribution,the minimum negative hypergeometric distribution,the likelihood ratio negative hypergeometric distribution and consequently the likelihood proportional negative hypergeometric distributiuon.To the extent that the sampling scheme is applicable to modelling data as illustrated with a biological example and in fact many situations of estimating Bernoulli parameters for binary traits within afinite population,these are important first-step results.

  19. Dynamic Vibration Absorber with Negative Stiffness for Rotor System

    Directory of Open Access Journals (Sweden)

    Hongliang Yao

    2016-01-01

    Full Text Available To suppress the vibration of a rotor system, a vibration absorber combining negative stiffness with positive stiffness together is proposed in this paper. Firstly, the negative stiffness producing mechanism using ring type permanent magnets is presented and the characteristics of the negative stiffness are analyzed. Then, the structure of the absorber is proposed; the principles and nonlinear dynamic characteristics of the absorber-rotor system are studied numerically. Finally, experiments are carried out to verify the numerical conclusions. The results show that the proposed vibration absorber is effective to suppress the vibration of the rotor system, the nonlinearity of the negatives stiffness affects the vibration suppression effect little, and the negative stiffness can broaden the effective vibration control frequency range of the absorber.

  20. Flat lens imaging does not need negative refraction

    OpenAIRE

    Kuo, Chao-Hsien; Ye, Zhen

    2003-01-01

    In a recent communication, Parimi et al. (Nature 426, 404 (2003)) reported the experimental results on imaging by a flat lens made of photonic crystals. They attributed the observed focusing to the negative refraction expected for the Left-Handed-Materials (LHMs). Here we demonstrate that the experimental observation is irrelevant to the negative refraction of LHMs. Rather, the phenomenon is a natural result of the anisotropic scattering by an array of scatterers.

  1. Long-pulse operation of an intense negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Takeiri, Yasuhiko; Osakabe, Masaki; Tsumori, Katsuyoshi; Kaneko, Osamu; Oka, Yoshihide; Asano, Eiji; Kawamoto, Toshikazu; Akiyama, Ryuichi; Kuroda, Tsutomu [National Inst. for Fusion Science, Nagoya (Japan)

    1997-02-01

    In the National Institute for Fusion Science, as the heating system for the Large Helical Device (LHD), the negative ion NBI system of 20 MW incident power has been planned, and the development of a large current, large size negative ion source has been advanced. Based on the results obtained so far, the design of the LHD-NBI system was reconsidered, and the specification of the actual negative ion source was decided as 180 KeV-40A. This time, the grounding electrode with heightened heat removal capacity was made, and the long pulse operation was attempted, therefore, its results are reported. The structure of the external magnetic filter type large negative ion source used for the long pulse experiment is explained. In order to form the negative ion beam of long pulses, it is necessary to form stable are discharge plasma for long time, and variable resistors were attached to the output side of arc power sources of respective filament systems. By adjusting the resistors, uniform are discharge was able to be caused for longer than 10 s stably. The results of the long pulse experiment are reported. The dependence of the characteristics of negative ion beam on plasma electrode temperature was small, and the change of the characteristics of negative ion beam due to beam pulse width was not observed. (K.I.)

  2. Negative selection of murine medullary-type single positive thymocytes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Negative selection depletes self-reactive T cells, thus ensuring self-tolerance. It is usually considered that negative selection imposed on double-positive (DP) thymocytes that reside at the cortico-medullary junction. Negative selection model was set up by injecting mice with anti-T cell receptor (TCR) monoclonal antibody (mAb) intraperitoneally in this work. As shown in phenotypic analysis of thymocytes, negative selection destroys not only cortical-type DP thymocytes, but also medullary-type CD3+TCRαβ+CD4SP and CD3+TCRαβ+CD8SP thymocytes. Negative selection of medullary-type single positive (SP) are more susceptible to apoptosis, while with development of the cells, their resistance to apoptosis increases. Therefore, negative selection does not operate on functionally mature thymocytes at the late stage. This result is a supplement to the traditional theory of negative selection. Negative selection of medullary-type thymocytes is probably to further deplete self-reactive T cells, thus producing precise TCR repertoire and inducing self-tolerance.

  3. LINGO-1 negatively regulates myelination by oligodendrocytes.

    Science.gov (United States)

    Mi, Sha; Miller, Robert H; Lee, Xinhua; Scott, Martin L; Shulag-Morskaya, Svetlane; Shao, Zhaohui; Chang, Jufang; Thill, Greg; Levesque, Melissa; Zhang, Mingdi; Hession, Cathy; Sah, Dinah; Trapp, Bruce; He, Zhigang; Jung, Vincent; McCoy, John M; Pepinsky, R Blake

    2005-06-01

    The control of myelination by oligodendrocytes in the CNS is poorly understood. Here we show that LINGO-1 is an important negative regulator of this critical process. LINGO-1 is expressed in oligodendrocytes. Attenuation of its function by dominant-negative LINGO-1, LINGO-1 RNA-mediated interference (RNAi) or soluble human LINGO-1 (LINGO-1-Fc) leads to differentiation and increased myelination competence. Attenuation of LINGO-1 results in downregulation of RhoA activity, which has been implicated in oligodendrocyte differentiation. Conversely, overexpression of LINGO-1 leads to activation of RhoA and inhibition of oligodendrocyte differentiation and myelination. Treatment of oligodendrocyte and neuron cocultures with LINGO-1-Fc resulted in highly developed myelinated axons that have internodes and well-defined nodes of Ranvier. The contribution of LINGO-1 to myelination was verified in vivo through the analysis of LINGO-1 knockout mice. The ability to recapitulate CNS myelination in vitro using LINGO-1 antagonists and the in vivo effects seen in the LINGO-1 knockout indicate that LINGO-1 signaling may be critical for CNS myelination.

  4. A Review of Chinese Redundant Negation

    Institute of Scientific and Technical Information of China (English)

    李璕

    2016-01-01

    Chinese redundant negation, characteristic of unecnomical language structure and illogical meaning expression, represents an intriguing language phenomenon well worth exploring. By far, plenty of researches have been made on Chinese redundant negation, encompassing researches on specific types of it microscopically and the issue of redundant negation in general macroscopically. This thesis attempts to conduct a review of Chinese redundant negation in the hope of deepening the understanding of this peculiar phenomenon meanwhile yeilding some pedagogical implication for second language teaching.

  5. Negative interest rates: why and how?

    OpenAIRE

    Kiselak, Jozef; Hermann, Philipp; Stehlik, Milan

    2016-01-01

    The interest rates (or nominal yields) can be negative, this is an unavoidable fact which has already been visible during the Great Depression (1929-39). Nowadays we can find negative rates easily by e.g. auditing. Several theoretical and practical ideas how to model and eventually overcome empirical negative rates can be suggested, however, they are far beyond a simple practical realization. In this paper we discuss the dynamical reasons why negative interest rates can happen in the second o...

  6. Self-Evaluation of Negative Symptoms: A Novel Tool to Assess Negative Symptoms.

    Science.gov (United States)

    Dollfus, Sonia; Mach, Cyril; Morello, Rémy

    2016-05-01

    Many patients with schizophrenia have negative symptoms, but their evaluation is a challenge. Thus, standardized assessments are needed to facilitate identification of these symptoms. Many tools have been developed, but most are based on observer ratings. Self-evaluation can provide an additional outcome measure and allow patients to be more engaged in their treatment. The aim of this study was to present a novel tool, Self-evaluation of Negative Symptoms (SNS), and demonstrate its validity. Forty-nine patients with schizophrenia and schizoaffective disorders according to DSM-5 were evaluated. Cronbach's coefficient (α = 0.867) showed good internal consistency. Factor analysis extracted 2 factors (apathy and emotional) that accounted for 75.2% of the variance. The SNS significantly correlated with the Scale of Assessment of Negative Symptoms (r= 0.628) and the Clinician Global Impression on the severity of negative symptoms (r= 0.599), supporting good convergent validity. SNS scores did not correlate with level of insight (r= 0.008), Parkinsonism (r= 0.175) or Brief Psychiatric Rating Scale positive subscores (r= 0.253), which indicates good discriminant validity. The intrasubject reliability of the SNS revealed excellent intraclass correlation coefficients (ICC = 0.942). Taken together, the results show that the SNS has good psychometric properties and satisfactory acceptance by patients. The study also demonstrates the ability of patients with schizophrenia to accurately report their own experiences. Self-assessments of negative symptoms should be more widely employed in clinical practice because they may allow patients with schizophrenia to develop appropriate coping strategies.

  7. Energy flow in negative index materials

    Institute of Scientific and Technical Information of China (English)

    Lorenzo Bolla; Michele Midrio; Carlo G. Someda

    2004-01-01

    From Maxwell's equations, we compute the speed and the direction of propagation of active power refractedfrom air into a negative index material. We prove, both analytically and numerically that the power mayrefract positively even if phase fronts refract negatively. Considerations on the usage of ray optics inproblems involving negative index materials are drawn.

  8. Enceladus Results

    Data.gov (United States)

    National Aeronautics and Space Administration — Here are some results from the Spectra Decomposition Algorithm on infrared spectral images of Saturn's moon Enceladus. Figure 1 is the spatial contribution of the...

  9. Negative refraction in a laminate

    Science.gov (United States)

    Willis, J. R.

    2016-12-01

    This work is concerned with the reflection and transmission of waves at a plane interface between a homogeneous elastic half-space and a half-space of elastic material that is periodically laminated. The lamination is always in the direction of the x1-coordinate axis and the displacement is always longitudinal shear, so that the only non-zero displacement component is u3(x1 ,x2 , t). After an initial discussion of Floquet-Bloch waves in the laminated material, brief consideration is given to the reflection-transmission problem, when the interface between the two media is the plane x1 = 0. Nothing unusual emerges: there are just a single reflected wave and a single transmitted wave, undergoing positive group-velocity refraction. Then, the problem is considered when the interface between the two media is the plane x2 = 0. The periodic structure of the interface induces an infinite set of reflected waves and an infinite set of transmitted waves. All need to be taken into account, but most decay exponentially away from the interface. It had previously been recognized that, if the incident wave had appropriate frequency and angle of incidence, a propagating transmitted wave would be generated that would undergo negative group-velocity refraction - behaviour usually associated with a metamaterial. It is established by an example in this work that there is, in addition, a propagating transmitted wave with smaller wavelength but larger group velocity that undergoes positive group-velocity refraction. The work concludes with a brief discussion of this finding, including its implications for the utility (or not) of "effective medium" theory.

  10. The use of negative themes in television food advertising.

    Science.gov (United States)

    Pettigrew, Simone; Roberts, Michele; Chapman, Kathy; Quester, Pascale; Miller, Caroline

    2012-04-01

    The ability of food advertising to trigger food consumption and influence social norms relating to food consumption has resulted in increasing attention being given to the prevalence and nature of food advertising. The present study investigated the use of negative themes in food advertisements aired on Australian television to determine the prevalence of depictions of violence/aggression, mocking, nagging, boredom, loneliness, food craving, mood enhancement, and the emotional use of food across 61 days of programming time. The results suggest that advertisers are using negative themes to capture attention and invoke an emotional response in the target audience. Sixteen percent (14,611) of the 93,284 food advertisements contained negative themes, with mood enhancement and food craving being the most commonly depicted negative themes. Advertisements with negative themes were more likely to be for non-core foods and to be aired during children's popular viewing times than at other times. The potential for negative themes in food advertising to promote unhealthy food consumption behaviors among children is likely to be of concern to policy makers. Building on this exploratory study, further research is needed to investigate how nutrition-related decision making is affected by exposure to food advertisements employing negative emotional themes.

  11. Analysis of CD117-negative gastrointestinal stromal tumors

    Institute of Scientific and Technical Information of China (English)

    Chin-Yuan Tzen; Bey-Liing Mau

    2005-01-01

    AIM: To identify the gastrointestinal stromal tumors(GISTs) that are negative for CD117 expression by immunohistochemistry and to characterize their malignant potential.METHODS: A total of 108 primary mesenchymal tumors of the gastrointestinal tract were screened to select CD117-negative tumors, from which KIT(exons 9, 11, 13, and 17)and PDGFRA (exons 10, 12, 14, and 18) were sequenced to identify GISTs. Tumor recurrence and distant metastasis were used as the criteria of malignancy.RESULTS: The result showed that approximately 25%(29/108) of the gastrointestinal mesenchymal tumors were negative for CD117 and approximately 6% (7/108)of the tumors were CD117-negative GISTs. All these CD117-negative tumors had a mutated KITand a wildtype PDGFRA. All CD117-negative GISTs with mutations at codons 557/558 of KIThad mitotic counts >10/50 high power field, and 75% (3/4) of them showed multiple recurrence or distant metastasis.CONCLUSION: CD1 17-negative KITmutated GISTs account for approximately 6% of the gastrointestinal mesenchymal tumors. Tumor recurrence or distant metastasis correlates to both theKITmutations at codons 557/558 and the mitotic counts, but not to the tumor size.

  12. Information Flow in Training Exercises with the Combined Arms Tactical Training Simulator (CATTS)

    Science.gov (United States)

    1977-11-01

    A 4 12 16 G & S 10 6 16 A & S 0 2 2 A & G & S 5 3 8 Fabrication 2 1 3 Total 41 44 85 aData are based on one training group. 17 example...position (0A14) . Feedback A The team commander reported that his unit was in " big trouble". He indicated that he would not be

  13. Magnetic moments of negative-parity baryons in QCD

    CERN Document Server

    Aliev, T M

    2014-01-01

    Using the most general form of the interpolating current for the octet baryons, the magnetic moments of the negative-parity baryons are calculated within the light-cone sum rules. The contributions coming from diagonal transitions of the positive-parity baryons, and also from non-diagonal transition between positive and negative-parity baryons are eliminated by considering the combinations of different sum rules corresponding to the different Lorentz structures. A comparison of our results on magnetic moments of the negative-parity baryons with the other approaches existing in literature is presented.

  14. Negative refraction at telecommunication wavelengths through plasmon-photon hybridization.

    Science.gov (United States)

    Kalusniak, Sascha; Sadofev, Sergey; Henneberger, Fritz

    2015-11-16

    We demonstrate negative refraction at telecommunication wavelengths through plasmon-photon hybridization on a simple microcavity with metallic mirrors. Instead of using conventional metals, the plasmonic excitations are provided by a heavily doped semiconductor which enables us to tune them into resonance with the infrared photon modes of the cavity. In this way, the dispersion of the resultant hybrid cavity modes can be widely adjusted. In particular, negative dispersion and negative refraction at telecommunication wavelengths on an all-ZnO monolithical cavity are demonstrated.

  15. Impact of Negative Sequence Current Injection by Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Göksu, Ömer; Teodorescu, Remus;

    2013-01-01

    This paper presents an analysis of the impact from negative sequence current injection by wind power plants in power systems under steady-state and short-term unbalanced conditions, including faults. The separate positive and negative sequence current control capability of the grid-side converters...... of full scale converter type wind turbines may be utilized to alter voltage imbalance at the point of connection and further into the grid, in turn changing the resultant negative sequence current flow in the grid. The effects of such control actions have been analyzed and discussed through theoretical...

  16. Gravitational Collapse, Negative World and Complex Holism

    CERN Document Server

    Sengupta, A

    2010-01-01

    Building on the engine-pump paradigm of ChaNoXity, this paper argues that complex holism - as the competitive homeostasis of dispersion and concentration - is the operating mode of Nature. Specifically, we show that the negative world \\mathfrak{W} is a gravitationally collapsed black hole that was formed at big-bang time t=0 as the pair (W,\\mathfrak{W}), with W a real world, and gravity the unique expression of the maximal multifunctional nonlinearity of the negative world \\mathfrak{W} in the functional reality of W. The temperature of a gravitationally collapsed system does enjoy the relationship T\\propto1/r with its radius, but the entropy follows the usual volumetric alignment with microstates, reducing to the surface approximation only at small r. It is not clear if quantum non-locality is merely a linear manifestation of complex holism, with the interaction of quantum gates in quantum entanglements resulting in distinctive features from the self-evolved structures of complex holism remaining an open ques...

  17. Universal corner contributions to entanglement negativity

    Science.gov (United States)

    Kim, Keun-Young; Niu, Chao; Pang, Da-Wei

    2016-09-01

    It has been realised that corners in entangling surfaces can induce new universal contributions to the entanglement entropy and Rényi entropy. In this paper we study universal corner contributions to entanglement negativity in three- and four-dimensional CFTs using both field theory and holographic techniques. We focus on the quantity χ defined by the ratio of the universal part of the entanglement negativity over that of the entanglement entropy, which may characterise the amount of distillable entanglement. We find that for most of the examples χ takes bigger values for singular entangling regions, which may suggest increase in distillable entanglement. However, there also exist counterexamples where distillable entanglement decreases for singular surfaces. We also explore the behaviour of χ as the coupling varies and observe that for singular entangling surfaces, the amount of distillable entanglement is mostly largest for free theories, while counterexample exists for free Dirac fermion in three dimensions. For holographic CFTs described by higher derivative gravity, χ may increase or decrease, depending on the sign of the relevant parameters. Our results may reveal a more profound connection between geometry and distillable entanglement.

  18. Negative Energy: From Lamb Shift to Entanglement

    CERN Document Server

    Bu, Shou-Liang

    2016-01-01

    "Negative energy" has been one of the most enduring puzzles in quantum theory, whereas the present work reveals that it actually plays a central role in clarifying various controversies of quantum theory. The basic idea is contained in a hypothesis on negative energy, and it is shown that the idea: (1)is compatible with both relativistic quantum mechanics and known experimental results; (2)helps to clarify the essence of matter waves, and therefore better understand the reality of the wave function, the so-called 'wave-packet reduction' occurring in quantum measurement, and the ghost like correlations between entangled systems; (3)is helpful for distinguishing the vacuum from the ground state of the quantized field, and may supply a possible way for removing the deep-rooted infinities in quantum field theory. The vacuum energy density of the electromagnetic field is calculated here as an example. By employing the same idea, the Lamb-Shift is recalculated in a different way from conventional renormalization me...

  19. How quantum are non-negative wavefunctions?

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, M. B. [Station Q, Microsoft Research, Santa Barbara, California 93106-6105, USA and Quantum Architectures and Computation Group, Microsoft Research, Redmond, Washington 98052 (United States)

    2016-01-15

    We consider wavefunctions which are non-negative in some tensor product basis. We study what possible teleportation can occur in such wavefunctions, giving a complete answer in some cases (when one system is a qubit) and partial answers elsewhere. We use this to show that a one-dimensional wavefunction which is non-negative and has zero correlation length can be written in a “coherent Gibbs state” form, as explained later. We conjecture that such holds in higher dimensions. Additionally, some results are provided on possible teleportation in general wavefunctions, explaining how Schmidt coefficients before measurement limit the possible Schmidt coefficients after measurement, and on the absence of a “generalized area law” [D. Aharonov et al., in Proceedings of Foundations of Computer Science (FOCS) (IEEE, 2014), p. 246; e-print arXiv.org:1410.0951] even for Hamiltonians with no sign problem. One of the motivations for this work is an attempt to prove a conjecture about ground state wavefunctions which have an “intrinsic” sign problem that cannot be removed by any quantum circuit. We show a weaker version of this, showing that the sign problem is intrinsic for commuting Hamiltonians in the same phase as the double semion model under the technical assumption that TQO-2 holds [S. Bravyi et al., J. Math. Phys. 51, 093512 (2010)].

  20. Optical Properties of Synthetic Cannabinoids with Negative Indexes

    CERN Document Server

    Shen, Yao

    2016-01-01

    Some kinds of psychoactive drugs have the structures which are called split-ring resonators (SRRs). SRRs might result in negative permittivity and permeability simultaneously in electromagnetic field. Simultaneous negative indexes can lead to the famous phenomenon of negative refraction. This optical property makes it possible to distinguish synthetic cannabinoids from other abusive psychoactive drugs in the UV-vis region. This optical method is non-damaged and superior in forensic science. In this paper, we use tight-binding model calculating the permittivity and permeability of the main ingredients of synthetic cannabinoids. At the same time, we give two more results of zolpidem and caffeine. Further we discuss the negative refraction of the category of zepam qualitatively.

  1. Drag and propulsive forces in electric sails with negative polarity

    Science.gov (United States)

    Sanchez-Torres, Antonio

    2016-02-01

    An electric solar sail (E-sail) is a recent propellantless propulsion concept for a direct exploration of the Solar System. An E-sail consists of a set of bare, conductive tethers at high positive/negative bias, prone to extract solar wind momentum by Coulomb deflection of protons. Additionally, a negatively biased E-sail has been proposed as a concept for de-orbiting space debris with drag forces produced in Low Earth Orbit (LEO). The present work focuses on the negative-bias case with a sheath that must be correctly modeled for a flowing plasma ambient. Ion scattering within the sheath and the resulting force are determined for several plasma conditions. Since the plasma flow does reduce the effective range for the ion scattering within the sheath, the resulting force is then reduced. Tethers at very high negative bias should be required for extremely high plasma flow.

  2. Negative Poisson's Ratio in Modern Functional Materials.

    Science.gov (United States)

    Huang, Chuanwei; Chen, Lang

    2016-10-01

    Materials with negative Poisson's ratio attract considerable attention due to their underlying intriguing physical properties and numerous promising applications, particularly in stringent environments such as aerospace and defense areas, because of their unconventional mechanical enhancements. Recent progress in materials with a negative Poisson's ratio are reviewed here, with the current state of research regarding both theory and experiment. The inter-relationship between the underlying structure and a negative Poisson's ratio is discussed in functional materials, including macroscopic bulk, low-dimensional nanoscale particles, films, sheets, or tubes. The coexistence and correlations with other negative indexes (such as negative compressibility and negative thermal expansion) are also addressed. Finally, open questions and future research opportunities are proposed for functional materials with negative Poisson's ratios.

  3. Impact of negation salience and cognitive resources on negation during attitude formation.

    Science.gov (United States)

    Boucher, Kathryn L; Rydell, Robert J

    2012-10-01

    Because of the increased cognitive resources required to process negations, past research has shown that explicit attitude measures are more sensitive to negations than implicit attitude measures. The current work demonstrated that the differential impact of negations on implicit and explicit attitude measures was moderated by (a) the extent to which the negation was made salient and (b) the amount of cognitive resources available during attitude formation. When negations were less visually salient, explicit but not implicit attitude measures reflected the intended valence of the negations. When negations were more visually salient, both explicit and implicit attitude measures reflected the intended valence of the negations, but only when perceivers had ample cognitive resources during encoding. Competing models of negation processing, schema-plus-tag and fusion, were examined to determine how negation salience impacts the processing of negations.

  4. Negative particle production at the CERN intersecting storage rings

    CERN Document Server

    Bertin, A; Cristallini, A; D'Agostino-Bruno, M; Ellis, R J; Giacomelli, G; Maroni, C; Mercatali, F; Rossi, A M; Vannini, G

    1972-01-01

    Preliminary results on the production of negative particles in inclusive reactions at intermediate angles (80-200 mrad) at the CERN ISR are reported. Pion production, is still the dominant process; within experimental errors, scaling holds for negative pions or alternatively a limiting distribution is reached at relatively low energies. However the antiproton production cross-sections are apparently larger than smaller energies. (14 refs).

  5. Negative Impact of HRM Complementarity on Knowledge Transfer in MNCs

    DEFF Research Database (Denmark)

    Minbaeva, Dana

    2005-01-01

    -related outcomes will result incrowding effect of extrinsic and intrinsic motivation and be negative. Hypothesesderived from these arguments are tested on the data from 92 subsidiaries of Danishmultinational corporations located in 11 countries.Extrinsic/intrinsic motivation, HRM practices, knowledge transfer......This paper explores reasons for negative complementarity among HRM practices. It isbuilt upon the premise that there are certain HRM practices influencing extrinsic andintrinsic motivation of knowledge receivers. If those HRM practices are applied in acomplementary way, their impact on knowledge...

  6. Onset of negative dispersion in one-component-plasma revisited

    CERN Document Server

    Khrapak, Sergey

    2016-01-01

    A simple approach to describe the long-wavelength dispersion of the longitudinal (plasmon) mode of the classical one-component-plasma (OCP), with the main objective to correctly capture the onset of negative dispersion, is proposed. The approach is applicable to both three-dimensional and two-dimensional OCP. The predicted onset of negative dispersion compares well with the available results from numerical simulations and more sophisticated theoretical models.

  7. Negative Refraction Angular Characterization in One-Dimensional Photonic Crystals

    OpenAIRE

    Jesus Eduardo Lugo; Rafael Doti; Jocelyn Faubert

    2011-01-01

    BACKGROUND: Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity d...

  8. On the Strong Rates of Convergence for Arrays of Rowwise Extended Negatively Dep endent Random Variables

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lu-lu; XU Chen; HUANG Xu-feng; WANG Xue-jun

    2014-01-01

    A general result on the strong convergence rate and complete convergence for arrays of rowwise extended negatively dependent random variables is established. As ap-plications, some well-known results on negatively dependent random variables can be easily extended to the case of arrays of rowwise extended negatively dependent random variables.

  9. A CLDN1-negative phenotype predicts poor prognosis in triple-negative breast cancer.

    Directory of Open Access Journals (Sweden)

    Fei Ma

    Full Text Available INTRODUCTION: Triple-negative breast cancer (TNBC is a heterogeneous disease with no definitive prognostic markers. As a major component of tight junctions, claudins (CLDNs presumably play an important role in carcinogenesis and progression of breast cancer. This study was aimed at determining the relationship between the expression of CLDNs and the clinical outcomes of TNBCs. MATERIALS AND METHODS: The surgical specimens of primary breast tumors from a consecutive cohort of 173 TNBC patients were retrospectively collected. The membranous expression of CLDN1, CLDN2, CLDN4, and CLDN7 was measured by immunohistochemistry. Then, the associations between CLDN expression, clinicopathological features, and clinical outcomes were assessed. RESULTS: Positive CLDN1, CLDN2, CLDN4, and CLDN7 membrane expression was detected in 44.5%, 54.9%, 76.9%, and 73.4% of the cohort specimens, respectively. A lack of CLDN1 expression was related to only lymph node metastasis (P = 0.014. The rate of CLDN4-positive tumors was significantly increased in tumors of a higher grade (P = 0.003. Importantly, negative CLDN1 expression was associated with worse relapse-free survival (RFS in both lymph node positive (LN+ and negative (LN- cases (both P<0.001. Similarly it was also associated with shorter overall survival (OS(P = 0.003 in LN+ cases; P = 0.018 in LN- cases. In the LN+ subgroup, CLDN2-negative cases had a significantly higher risk of recurrence (P = 0.008. Multivariate analysis revealed that negative CLDN1 expression was an independent prognostic factor for high risk of both recurrence and death (HR 5.529, 95% CI 2.664-11.475, P<0.001; HR 3.459, 95% CI 1.555-7.696, P = 0.002. However, neither CLDN4 nor CLDN7 expression was associated with survival. CONCLUSION: In TNBC, the CLDN1-negative phenotype predicts a high risk of recurrence and death. The absence of CLDN1 expression is strongly suggested to be an independent adverse prognostic factor

  10. Safety and efficacy of combination therapy of interferon-alpha2 + JAK1-2 Inhibitor in the philadelphia-negative chronic myeloproliferative neoplasms. Preliminary results from the danish combi-trial-an open label, single arm, non-randomized multicenter phase II study

    DEFF Research Database (Denmark)

    Mikkelsen, S. U.; Kjaer, L.; Skov, V.

    2015-01-01

    Background: The Philadelphia-negative, chronic myeloproliferative neoplasms (MPN) include essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (MF) (PMF). Chronic inflammation and a deregulated immune system are considered important for clonal evolution and disease....... Hct control without phlebotomy was achieved by week 4 in 78 % of pts (7 of 9), who at baseline had an elevated hct. Only 3 pts required a total of 3 phlebotomies after initiation of CT. In Figure 1 median hct levels at 0, 1, 3, 6 months are shown. Overall, complete response (CR) was achieved as best......) or major response (n=2) was achieved in 4 pts (57.1%) by week 2 or 1 month, and NR in 3 pts (42.8%). Among PPV-MF pts, 2 pts (66.7%) achieved CR and 1 patient (33,3%) PR by week 2. Furthermore, JAK2V617F% declined significantly as depicted in Figure 2 (JAK2V617F% over time for each patient) and 3 (median...

  11. Tunelling with a negative cosmological constant

    CERN Document Server

    Gibbons, G W

    1996-01-01

    The point of this paper is see what light new results in hyperbolic geometry may throw on gravitational entropy and whether gravitational entropy is relevant for the quantum origin of the univeres. We introduce some new gravitational instantons which mediate the birth from nothing of closed universes containing wormholes and suggest that they may contribute to the density matrix of the universe. We also discuss the connection between their gravitational action and the topological and volumetric entropies introduced in hyperbolic geometry. These coincide for hyperbolic 4-manifolds, and increase with increasing topological complexity of the four manifold. We raise the questions of whether the action also increases with the topological complexity of the initial 3-geometry, measured either by its three volume or its Matveev complexity. We point out, in distinction to the non-supergravity case, that universes with domains of negative cosmological constant separated by supergravity domain walls cannot be born from ...

  12. Formation of Voids from Negative Density Perturbations

    Science.gov (United States)

    de Araujo, J. C. N.; Opher, R.

    1990-11-01

    RESUMEN. Se estudia la formaci6n de huecos a partir de un espectro negativo de perturbaciones, tomando en cuenta la expansi6n del Universo, arrastre por fotones, enfriamiento por fotones, fotoionizaci6n, ioniza- ci6n colisional, enfriamiento Lyman a y la formaci6n y enfriamiento de moleculas H2. Nuestros resultados predicen la existencia de regiones 1/10 de Ia densidad promedio para regiones de masa lO - 1O10M . ABSTRACT. In the present paer we study the formation of voids from a negative spectrum of perturbations taking into account the expansion of the Universe, photon-drag, photon-cooling, photoionization, collisional ionization, Lyman a cooling and the formation and cooling of 112 molecules. Our results predict the existence of regions 1/10 the average density for regions of mass 1O - 1O10M@ : CLUSTERS-GALAXIES - COSMOLOGY

  13. Three-dimensional optical metamaterial with a negative refractive index.

    Science.gov (United States)

    Valentine, Jason; Zhang, Shuang; Zentgraf, Thomas; Ulin-Avila, Erick; Genov, Dentcho A; Bartal, Guy; Zhang, Xiang

    2008-09-18

    Metamaterials are artificially engineered structures that have properties, such as a negative refractive index, not attainable with naturally occurring materials. Negative-index metamaterials (NIMs) were first demonstrated for microwave frequencies, but it has been challenging to design NIMs for optical frequencies and they have so far been limited to optically thin samples because of significant fabrication challenges and strong energy dissipation in metals. Such thin structures are analogous to a monolayer of atoms, making it difficult to assign bulk properties such as the index of refraction. Negative refraction of surface plasmons was recently demonstrated but was confined to a two-dimensional waveguide. Three-dimensional (3D) optical metamaterials have come into focus recently, including the realization of negative refraction by using layered semiconductor metamaterials and a 3D magnetic metamaterial in the infrared frequencies; however, neither of these had a negative index of refraction. Here we report a 3D optical metamaterial having negative refractive index with a very high figure of merit of 3.5 (that is, low loss). This metamaterial is made of cascaded 'fishnet' structures, with a negative index existing over a broad spectral range. Moreover, it can readily be probed from free space, making it functional for optical devices. We construct a prism made of this optical NIM to demonstrate negative refractive index at optical frequencies, resulting unambiguously from the negative phase evolution of the wave propagating inside the metamaterial. Bulk optical metamaterials open up prospects for studies of 3D optical effects and applications associated with NIMs and zero-index materials such as reversed Doppler effect, superlenses, optical tunnelling devices, compact resonators and highly directional sources.

  14. Characterization of Patients with Helicobacter pylori-Negative Peptic Ulcers

    Directory of Open Access Journals (Sweden)

    Roberto Hernández Conde

    2013-10-01

    Full Text Available Background: the rate of Helicobacter pylori-negative ulcers is increasing. Treatment with nonsteroidal anti-inflammatory drugs and other ulcerogenic drugs plays a significant role.Objective: to characterize patients with Helicobacter pylori-negative peptic ulcer. Methods: a case series study of patients attended by the Gastroenterology Service of the Hermanos Ameijeiras Hospital was conducted in the year 2009. Demographic, epidemiological, clinical, endoscopic and histological variables were studied. Mean and standard deviation were analyzed; logistic regression, t-Student and Chi-square tests were used. Results: A total of 269 gastric ulcers, 239 duodenal ulcers and 41 combined were diagnosed; 115 cases were Helicobacter pylori-negative and 434 were positive. Nonsteroidal anti-inflammatory drugs were associated with 33,9 % of H. pylori-negative patients and 22.8% of the positive patients. Ulcerative syndrome occurred in 47 % and 45% in both groups. All H. pylori-negative duodenal ulcers were located in the duodenal bulb as well as 96, 6 % of the positive. The antrum was the most common location for gastric ulcerations (92.3% negative; 90.5% positive. Multiple ulcers predominated in the duodenum while double ulcers prevailed in the stomach, all negative for H.pylori. Antral gastritis predominated (73. 0 % H. pilory- negative, the level of activity was higher in the positive cases (97. 0 % and intestinal metaplasia was similar for both groups. Conclusions: in patients with H. pylori-negative peptic ulcer, non-steroidal anti-inflammatory drugs should be taken into consideration as one of the main factors associated with this entity.

  15. NEGATIVE EFFECT OF METALLOID STRESS ON WHEAT

    Directory of Open Access Journals (Sweden)

    Marína Maglovski

    2015-02-01

    Full Text Available Arsenic (As belongs to heavy metals and its accumulation in plants, besides damaging the organism itself, represents a potential health risk to animal and human consumers. Therefore, contamination of soils and waters with this compound is a serious environmental problem. In this work we focused on investigating a negative impact of As on selected parameters of growth of wheat plants (Triticum aestivum L. cv. Genoveva grown in hydropony. In the stage of first assimilation leaves we applied a solution of heavy metal (1 mg.kg-1 As3+ on wheat plants. For plants grown under hydropony conditions we observed different plant parameters such as length, weight, amount of fresh and dry biomass. Further we analyzed accumulation of hydrogen peroxide and products membrane lipid peroxidation as indicators of oxidative stress. In addition to these we also measured the content of photosynthetic pigments, maximal quantum yield and proline in plant tissue. Our data indicate reduction of the biomass of shoots forthcoming as a result of exposure of stressed plants to As. Decline of biomass accumulation was accompanied by increase of hydrogen peroxide in plant tissue. In contrast, level of lipid peroxidation was suppressed in stressed shoots. Contents of photosynthetic pigments soundly decreased. Interestingly, fluorescence (Fp=Fm in stressed wheat shoots increased. Similarly in tested shoots the content of proline was increased. The results indicate that the applied dose of As has a negative impact on the growth and photosynthetic performance of stressed plants. A better understanding of the mechanisms responsible for As resistance and toxicity in plants requires further investigation.

  16. Oblique effect in visual mismatch negativity

    Directory of Open Access Journals (Sweden)

    Endre eTakács

    2013-09-01

    Full Text Available We investigated whether visual orientation anisotropies (known as oblique effect exist in non-attended visual changes using event-related potentials (ERP. We recorded visual mismatch negativity (vMMN which signals violation of sequential regularities. In the visual periphery unattended, task-irrelevant Gábor patches were displayed in an oddball sequence while subjects performed a tracking task in the central field. A moderate change (50° in the orientation of stimuli revealed no consistent change-related components. However we found orientation-related differences around 170 ms in occipito-temporal areas in the amplitude of the ERPs evoked by standard stimuli. In a supplementary experiment we determined the amount of orientation difference that is needed for change detection in an active, attended paradigm. Results exhibited the classical oblique effect; subjects detected 10° deviations from cardinal directions, while threshold from oblique directions was 17°. These results provide evidence that perception of change could be accomplished at significantly smaller thresholds, than what elicits vMMN. In Experiment2 we increased the orientation change to 90°. Deviant-minus-standard difference was negative in occipito-parietal areas, between 120-200 ms after stimulus onset. VMMNs to changes from cardinal angles were larger and more sustained than vMMNs evoked by changes from oblique angles. Changes from cardinal orientations represent a more detectable signal for the automatic change detection system than changes from oblique angles, thus increased vMMN to these larger deviances might be considered a variant of the magnitude of deviance effect rarely observed in vMMN studies.

  17. Bug hunting with false negatives

    NARCIS (Netherlands)

    Calamé, Jens; Ioustinova, Natalia; Pol, van de Jaco; Sidorova, Natalia; Davies, J.; Gibbons, J.

    2007-01-01

    Safe data abstractions are widely used for verification purposes. Positive verification results can be transferred from the abstract to the concrete system. When a property is violated in the abstract system, one still has to check whether a concrete violation scenario exists. However, even when the

  18. Nonlinear Negative Refraction by Difference Frequency Generation

    CERN Document Server

    Cao, Jianjun; Feng, Yaming; Wan, Wenjie

    2015-01-01

    Negative refraction has attracted much interest for its promising capability in imaging applications. Such an effect can be implemented by negative index meta-materials, however, which are usually accompanied by high loss and demanding fabrication processes. Recently, alternative nonlinear approaches like phase conjugation and four wave mixing have shown advantages of low-loss and easy-to-implement, but associated problems like narrow accepting angles can still halt their practical applications. Here we demonstrate theoretically and experimentally a new scheme to realize negative refraction by nonlinear difference frequency generation with wide tunability, where a thin BBO slice serves as a negative refraction layer bending the input signal beam to the idler beam at a negative angle. Furthermore, we realize optical focusing effect using such nonlinear negative refraction, which may enable many potential applications in imaging science.

  19. Nonlinear negative refraction by difference frequency generation

    Science.gov (United States)

    Cao, Jianjun; Shen, Dongyi; Feng, Yaming; Wan, Wenjie

    2016-05-01

    Negative refraction has attracted much interest for its promising capability in imaging applications. Such an effect can be implemented by negative index meta-materials, however, which are usually accompanied by high loss and demanding fabrication processes. Recently, alternative nonlinear approaches like phase conjugation and four wave mixing have shown advantages of low-loss and easy-to-implement, but associated problems like narrow accepting angles can still halt their practical applications. Here, we demonstrate theoretically and experimentally a scheme to realize negative refraction by nonlinear difference frequency generation with wide tunability, where a thin Beta barium borate slice serves as a negative refraction layer bending the input signal beam to the idler beam at a negative angle. Furthermore, we realize optical focusing effect using such nonlinear negative refraction, which may enable many potential applications in imaging science.

  20. Performance of Variable Negative Stiffness MRE Vibration Isolation System

    Directory of Open Access Journals (Sweden)

    Run-pu Li

    2015-01-01

    Full Text Available Magnetorheological elastomer (MRE vibration isolation devices can improve a system’s vibration response via adjustable stiffness and damping under different magnetic fields. Combined with negative stiffness design, these MRE devices can reduce a system’s stiffness and improve the vibration control effect significantly. This paper develops a variable negative stiffness MRE isolation device by combining an improved separable iron core with laminated MREs. The relationship between the negative stiffness and the performance of the device is obtained by mathematical transformation. Its vibration response under simple harmonic excitation at small amplitude and the impact of the volume fraction of soft magnetic particles on the isolation system are also analyzed. The results show that the negative stiffness produced by the magnetic force is a major factor affecting the capacity of the isolation system. Compared to devices of the same size, the isolation system equipped with low-particle volume fraction MREs demonstrates better performance.

  1. Textile inspired flexible metamaterial with negative refractive index

    Science.gov (United States)

    Burgnies, L.; Lheurette, É.; Lippens, D.

    2015-04-01

    This work introduces metallo-dielectric woven fabric as a metamaterial for phase-front manipulation. Dispersion diagram as well as effective medium parameters retrieved from reflection and transmission coefficients point out negative values of refractive index. By numerical simulations, it is evidenced that a pair of meandered metallic wires, arranged in a top to bottom configuration, can yield to a textile metamaterial with simultaneously negative permittivity and permeability. While the effective negative permittivity stems from the metallic grid arrangement, resonating current loop resulting from the top to bottom configuration of two meandered metallic wires in near proximity produces magnetic activity with negative permeability. By adjusting the distance between pairs of metallic wires, the electric plasma frequency can be shifted to overlap the magnetic resonance. Finally, it is shown that the woven metamaterial is insensitive to the incident angle up to around 60°.

  2. [Nuclear morphology in false negative and negative rectal biopsies (author's transl)].

    Science.gov (United States)

    Rilke, F; Clemente, C; Pilotti, S

    1975-01-01

    An typical nuclear structure consisting of a cribriform and condensed chromatin pattern with hyperchromasia, a small nucleolus and a moderately increased nuclear-cytoplasmic ratio was observed in the epithelial cells of the crypts and in the stromal and muscular cells of 51 out of 70 oncologically negative biopsies of the rectal mucosa. The subsequent retrieval of all clinical and histologia data revealed that the 51 cases included 39 of adenocarcinoma of the large intestine either present (15 cases) at a variable distance from the false negative biopsy or removed previously (24 cases), 7 of extra-intestinal malignant tumor (parotid gland, urinary bladder, endometrium, breast, stomach, metastatic, anus) and 5 with benign conditions of the large intestine. Of the remaining 19 cases whose biopsies did not reveal the atypical nuclear structure 16 had benign lesions of the large intestine and nowhere evidence of malignancy, two had an adenocarcinoma of the large bowel (one present and one removed previously) and one a carcinoma of the anus. In the rectal biopsies examined the atypical nuclear structure was detected in 93.9% of the cases with a malignant tumor either present or removed previously and in 19% of the cases with benign conditions. The morphologic evidence indicated that the atypical nuclear structure was compatible with a possible distrubance of the mitotic cycle since the findings were restricted to the generative compartment of rectal epithelium. The results are discussed in connection with their possible practical use as a diagnostic aid in the evaluation and interpretation of false negative and negative rectal biopsies as well as with their possible significance in the biology of tumor-bearing hosts.

  3. Negative refraction in natural ferromagnetic metals

    OpenAIRE

    Engelbrecht, Sebastian; Shuvaev, Alexey Mikhailovich; Luo, Y.; Moshnyaga, V.; Pimenov, Andrei

    2010-01-01

    It is generally believed that Veselago's criterion for negative refraction cannot be fulfilled in natural materials. However, considering imaginary parts of the permittivity ({\\epsilon}) and permeability ({\\mu}) and for metals at not too high frequencies the general condition for negative refraction becomes extremely simple: Re({\\mu}) Re(n) < 0. Here we demonstrate experimentally that in such natural metals as pure Co and FeCo alloy the negative values of the refractive index are achi...

  4. Conscientiousness predicts greater recovery from negative emotion

    OpenAIRE

    Kristin N Javaras; Schaefer, Stacey M.; van Reekum, Carien M.; Lapate, Regina C.; Greischar, Lawrence L.; Bachuber, David R.; Love, Gale; Ryff, Carol D.; Richard J Davidson

    2012-01-01

    Greater levels of conscientiousness have been associated with lower levels of negative affect. We focus on one mechanism through which conscientiousness may decrease\\ud negative affect: effective emotion regulation, as reflected by greater recovery from negative stimuli. In 273 adults who were 35 - 85 years old, we collected self-report measures of personality including conscientiousness and its self-control facet, followed\\ud on average 2 years later by psychophysiological measures of emotio...

  5. Enhanced Negative Feedback Responses in Remitted Depression

    OpenAIRE

    Pizzagalli, Diego; Meites, Tiffany M.; Deveney, Christen M; Holmes, Avram J.; Bogdan, Ryan; Steele, Katherine T.; Santesso, Diane L.

    2008-01-01

    Major depressive disorder (MDD)is characterized by hypersensitivity to negative feedback that might involve frontocingulate dysfunction. MDD patients exhibit enhanced electrophysiological responses to negative internal (errors) and external (feedback) cues. Whether this dysfunction extends to remitted depressed (RD) individuals with a history of MDD is currently unknown. To address this issue, we examined the feedback-related negativity in RD and control participants using a probabilistic pun...

  6. Copper and the negative price of storage

    OpenAIRE

    Larson, Donald Frederick; DEC

    1994-01-01

    Commodities are often stored during periods in which storage returns a negative price. Further, during periods of"backwardation,"the expected revenue from holding inventories will be negative. Since the 1930s, the negative price of storage has been attributed to an offsetting"convenience yield."It has been argued that inventories are a necessary adjunct to business and that increasing inventories from some minimal level reduces overall costs. This theory has always been criticized by proponen...

  7. Design of double negativity elastic metamaterial

    Directory of Open Access Journals (Sweden)

    Y.C. Su

    2015-01-01

    Full Text Available A metamaterial model that possesses simultaneously negative effective mass density and negative effective Young’s modulus is proposed in this study. Dispersion curves and dynamic responses of the model are investigated. In the double negative frequency region, it is demonstrated that the phase velocity is negative. In addition, it was found that the band gap region of the metamaterial can be predicted accurately by taking parts of single-unit cell to analyze the steady-state response. The design is also fabricated by a 3D printer.

  8. 40 CFR 52.122 - Negative declarations.

    Science.gov (United States)

    2010-07-01

    ... air pollution control districts submitted negative declarations for volatile organic compound source... Operations, Rubber Tire Manufacturing, Polymer Manufacturing, Industrial Wastewater, Ship Building and...

  9. Pais-Uhlenbeck Oscillator and Negative Energies

    CERN Document Server

    Pavšič, Matej

    2016-01-01

    We review the occurrence of negative energies in Pais-Uhlenbeck oscillator. We point out that in the absence of interactions negative energies are not problematic, neither in the classical nor in the quantized theory. However, in the presence of interactions that couple positive and negative energy degrees of freedom the system is unstable, unless the potential is bounded from bellow and above. We review some approaches in the literature that attempt to avoid the problem of negative energies in the Pais-Uhlenbeck oscillator.

  10. Negative thermal expansion due to negative area compressibility in TlGaSe2 semiconductor with layered crystalline structure

    Science.gov (United States)

    Seyidov, MirHasan Yu.; Suleymanov, Rauf A.

    2010-09-01

    We conducted comparison of the original experimental data of the temperature dependences of thermal expansion in crystals with layered crystalline structure. It is shown that in most crystals with layered structure (graphite, boron nitride, GaSe, GaS, and InSe) the effect of negative thermal expansion can be explained by the specific character of the phonon spectra. It was shown, that in contrast to other crystals with layered structure, negative thermal expansion in the layers' plane of TlGaSe2 is the result of negative area compressibility. We demonstrate that the thermal expansion of TlGaSe2 crystals can be controlled by illumination, external electric field, and thermal annealing. The nature of observed effects and a special mechanism of the negative area compressibility in TlGaSe2 crystals are discussed.

  11. Clinicopathological Features of Triple Negative Breast Carcinoma

    Science.gov (United States)

    Reddy, Gowry Maram; Pai, Radha R.

    2017-01-01

    Introduction Breast carcinoma is one of the most common malignancies affecting women in developing countries. Molecular studies of breast carcinoma have classified the tumour based on the immunohistochemical staining into 4 subtypes, such as Luminal A, Luminal B, HER2/neu Positive and Triple Negative Breast Carcinoma (TNBC). TNBCs are reported to have an aggressive behaviour and wide metastasis, leading to selective treatment outcomes. Aim The aim was to study the clinicopathological features such as age, site, tumour size, histopathological type, histologic grade, lymph node status, stage and treatment outcomes of triple negative breast carcinoma. Materials and Methods A retrospective study was conducted on 108 cases of breast carcinoma received during the period of 2 years. The tumour was classified based on immunohistochemical staining into four subtypes. The clinicopathological details, histomorphological and immunohistochemical features of TNBC were studied. Results Of the 108 patients, 34 patients were diagnosed as TNBC. The average age at presentation was 48 years. Most of the cases showed Nottingham Modification of Scarff Bloom-Richardson (NMBR) grade 3 (55.9%) and stage II (67.6%). Ly-mph node metastasis was seen in 50% of cases. Infiltrating ductal carcinoma (not otherwise specified) type (91.2%) was the most common histological type. Among the other subtypes, Luminal A carcinoma was the most common (36.1%), followed by TNBC (31.5%) and HER2/neu positive carcinomas (28.7%). Compared to the other types of tumours, TNBC showed the most frequent distant lymph node metastasis (50%) when compared to luminal A (38.5%), luminal B (25%), HER2/neu positive (48.4%). Unlike the other types of tumours, TNBC were mostly high-grade. Conclusion TNBC have an aggressive behaviour compared to other subtypes with higher NMBR grade, nuclear pleomorphism, high mitotic rate and lymph node metastasis. PMID:28273970

  12. Triple negative breast cancer: an Indian perspective

    Directory of Open Access Journals (Sweden)

    Akhtar M

    2015-08-01

    Full Text Available Murtaza Akhtar, Subhrajit Dasgupta, Murtuza Rangwala Department of Surgery, NKP Salve Institute of Medical Sciences and Research Centre, Nagpur, Maharashtra, India Introduction: Breast cancer is the most common female cancer in the world. Triple negative breast cancer (TNBC is a recently identified biological variant with aggressive tumor behavior and poor prognosis. Data of hormonal status from the Indian population is scarce due to financial constraints in performing immunohistochemistry evaluation. The present study aims to prospectively analyze receptor status of all breast cancer patients and identify TNBC and compare their clinical profile and short term survival with other non-TNBC group. Materials and methods: All cytologically and histopathologically confirmed cases of carcinoma breast were prospectively enrolled. In a longitudinal study at tertiary care hospital in central India based on the hormonal status, they were further divided into TNBC and other groups. Comparison of risk factors, clinical profile and short-term survival was carried out. Results: A total 85 patients were enrolled and of them 37 (43.7% were TNBC. On comparing risk factors ie, age, age at menarche, total reproductive age, age at first child birth, and menopausal status – no statistical significance was observed between the TNBC and non-TNBC groups. But on comparison of clinical profile TNBC tumors were significantly large with majority of patients presenting as locally advanced breast cancer (83%. No statistical difference was observed in axillary lymph node status between two groups. TNBC tumors were histologically more aggressive (grade 3 compared to other groups. No statistically significant difference was observed in short term overall survival but all three deaths were observed in the TNBC group only and two local recurrences after surgery were observed in the TNBC group. Conclusion: TNBC forms a large proportion of carcinoma breast patients in a central

  13. Negation in Igálà Negation in Igálà

    Directory of Open Access Journals (Sweden)

    Johnson Folorunso ILORI

    2012-06-01

    Full Text Available Unlike other Yoruboid languages, Igálà uses a double negation syntax which combines two independent but mutually obligatory elements to generate a single semantic unit of negation. Apart from providing a description of Igálà negatio nsystem, this paper, relying on instruments of minimalist grammar as propounded in Chomsky (1995, 1998, 2002, argues for a negative clause projection in which there are two separate but interdependent Neg projections – NegP1 and NegP2 - such that Negº2 takes NegP1 as complement to project NegP2. Spell-out constituent ordering derives from Negº2 ń/nóò attracting NegP1 to Spec-NegP2 resulting in the word order where Negº2 obligatorily ends negative clause expressions in Igálà. This grammar structurally predicts that nothing follows Negº2 ń/nóò in the linear orderof words in Igálà negative clause constructions.Diferentemente de outras línguas Yoruboid, Igalá usa uma sintaxe da dupla negação que combina dois elementos independentes, mas mutuamenteo brigatórios para gerar uma única unidade semântica de negação. Além de prover uma descrição do sistema de negação do Igalá, esse artigo, apoiado em instrumentos da gramática minimalista, como proposta por Chomsky (1995, 1998, 2002, defende uma projeção da oração negativa em que há duas projeções Neg separadas, mas interdependentes - NegP1 e NegP2 - de tal modo que Negº2 toma NegP1 como complemento para projetar NegP2. A ordenação do constituinte explícito deriva de a Negº2 ń/nóò atrair NegP1 para SpecNegP2, resultando numa ordem de palavras em que Negº2 obrigatoriamente fica no final de orações negativas em Igalá. Esta gramática prevê estruturalmente que nada segue Negº2 ń/nóò na ordem linear de palavras em construções oracionais negativas em Igalá.

  14. The Relationship between Negative Affect and Reported Cognitive Failures

    Directory of Open Access Journals (Sweden)

    Tabitha W. Payne

    2014-01-01

    Full Text Available The purpose of this study was to expand our understanding of the range of negative affect associated with reported problems with everyday functions and activities, measured by the cognitive failures questionnaire (CFQ. Evidence from previous research indicates that individuals meeting criteria for mood disorders, such as major depression or seasonal affective disorder, experience cognitive deficits in memory and attention that can lead to problems with everyday activities reported in the CFQ. The Positive and Negative Affect Scale (PANAS was used to assess potential correlations with a wider range of negative emotions. Findings for a sample of 129 college students revealed that negative affective experiences were significantly correlated with failures of memory and attention on the CFQ (fear = .41, hostility = .38, sadness = .28, and guilt = .43. Conversely, positive affect was negatively correlated with distractibility (r=−.21. Additional affective scales on the PANAS (e.g., shyness and fatigue were also associated with higher reports of cognitive failures. The results provide converging evidence of a relationship between negative affective experiences and reported frequency of problems on the cognitive failures questionnaire.

  15. Negative addiction to exercise: are there differences between genders?

    Directory of Open Access Journals (Sweden)

    Vladimir Bonilha Modoio

    2011-01-01

    Full Text Available INTRODUCTION: Regular physical exercise has numerous benefits. However, there is a subset of the exercising population who may develop a compulsion to exercise excessively and who may, as a consequence, display physiological and psychological changes that have a direct influence on their quality of life. OBJECTIVE: Our objective was to determine if there are differences between male and female athletes' scores on measures of negative addiction symptoms, quality of life, mood and sleep. METHODS: 144 female and 156 male athletes participated in this study by answering the following questionnaires: Negative Addiction Scale, Beck Depression Inventory, Trait Anxiety Inventory, Profile of Mood States, SF-36 Quality of Life, Pittsburgh Sleep Quality and Epworth Sleepiness Scale. RESULTS: Higher dedication to training sessions in the male group, and members of the female group with symptoms of negative addiction to exercise showed a lower score on vigor observed by the Profile of Mood States compared to the males in both situations. We also observed depression symptoms in both members of groups who had negative addiction symptoms when compared with their peers without symptoms, and these figures were even higher in females compared with the male group in the same situation. CONCLUSION: No differences were seen in the development of negative addiction exercise symptoms in males and females and there were no changes in the quality of life and mood of these athletes. Further studies of eating disorders associated with changes in body image perception could contribute to a better understanding of negative addiction to exercise.

  16. A triple negative breast cancer: what it is not!

    Directory of Open Access Journals (Sweden)

    Katakkar SB

    2012-02-01

    Full Text Available Suresh B KatakkarRegional Medical Oncology Hematology Leader, Centre for the North, BC Cancer Agency, Prince George, British Columbia, CanadaAbstract: The triple negative cancer is an unusual, and at the same time, a unique entity where the discordance rate is almost 18%. That means 18% of Her2 negative results will transform into a Her2 positive status and will have the affinity to spread to the central nervous system (CNS. With the identification of CD44, CD24, and ALDH1, we may be able to determine which group of triple negative breast cancer patients will have CNS metastasis. This case illustrates the Her2 expressing cells have higher CNS affinity. As the original tumor was Her2 negative, if a genomic assay was then done on this patient, we would have identified the potential of CNS involvement. In conclusion, genomic assays should be routinely done on triple negative cancers.Keywords: triple negative, breast cancer, claudin high or low, genomic microassay

  17. Prevalence of rhesus negativity among pregnant women

    Directory of Open Access Journals (Sweden)

    Ezhil Arasi Nagamuthu

    2016-08-01

    Conclusions: The prevalence of Rh D negative women is low when compared to Rh D positive women.There is a need for adequate counselling of pregnant women on the importance of Rh D negative factor during the antenatal period in order to prevent hemolytic disease of the newborn. [Int J Res Med Sci 2016; 4(8.000: 3305-3309

  18. Brouwer and Griss on intuitionistic negation

    OpenAIRE

    Franchella, Miriam

    1994-01-01

    During the 1940s, a debate about the intuitionistic definition of negation took place between G .F. C. Griss and L. E. J. Brouwer: namely, Griss criticized Brouwer's definition as inconsistent with the intuitionistic framework. In this paper I present firstly Brouwer's definition of negation; then Griss' criticism of it and his proposal of a "negationless" mathematics; finally Brouwer's reply to Griss.

  19. A negative ion source for alkali ions

    NARCIS (Netherlands)

    Vermeer, A.; Zwol, N.A. van

    1980-01-01

    An ion source is described which delivers negative alkali ions. With this source, which consists of a duoplasmatron and a charge exchange canal with alkali vapour, negative Li, Na and K ions are produced. The oven in which alkali metals are evaporated can reach temperatures up to 575°C.

  20. Estimation for Entanglement Negativity of Free Fermions

    CERN Document Server

    Herzog, Christopher P

    2016-01-01

    In this letter we study the negativity of one dimensional free fermions. We derive the general form of the $\\mathbb{Z}_{N}$ symmetric term in moments of the partial transposed (reduced) density matrix, which is an algebraic function of the end points of the system. Such a path integral turns out to be a convenient tool for making estimations for the negativity.

  1. The degree functions of negative adjectives

    NARCIS (Netherlands)

    Weidman Sassoon, G.

    2010-01-01

    This paper provides a new account of positive versus negative antonyms. The data includes well-known linguistic generalizations regarding negative adjectives, such as their incompatibility with measure phrases (cf. two meters tall/ *short) and ratio phrases (twice as tall/ #short) as well as the imp

  2. Distress attributed to negative symptoms in schizophrenia

    NARCIS (Netherlands)

    Selten, JP; Wiersma, D; van den Bosch, RJ

    2000-01-01

    The purpose of the study was to examine (1) to which negative symptoms schizophrenia patients attribute distress and (2) whether clinical variables can predict the levels of reported distress. With the help of a research assistant, 86 hospitalized patients completed a self-rating scale for negative

  3. Atomic Gases at Negative Kinetic Temperature

    NARCIS (Netherlands)

    Mosk, A.P.

    2005-01-01

    We show that thermalization of the motion of atoms at negative temperature is possible in an optical lattice, for conditions that are feasible in current experiments. We present a method for reversibly inverting the temperature of a trapped gas. Moreover, a negative-temperature ensemble can be coole

  4. Negative Learning Rates and P-Learning

    OpenAIRE

    Merrill, Devon

    2016-01-01

    We present a method of training a differentiable function approximator for a regression task using negative examples. We effect this training using negative learning rates. We also show how this method can be used to perform direct policy learning in a reinforcement learning setting.

  5. Negative Priming in Free Recall Reconsidered

    Science.gov (United States)

    Hanczakowski, Maciej; Beaman, C. Philip; Jones, Dylan M.

    2016-01-01

    Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and…

  6. First observation and mobility measurements of negative ions in superfluid He-4

    NARCIS (Netherlands)

    Kasimova, A; Zuhlke, C; Jungmann, K; Putlitz, GZ

    2003-01-01

    We present the results of the first mobility measurements in superfluid helium for negative ions of different elements. Various negative ions like Cl-, F- and I- were produced by laser ablation from targets consisting of NaCl, NaF, NaI, LiF and KCl immersed in a He-4 bath. In addition to negative io

  7. First observation and mobility measurements of negative ions in superfluid 4He

    NARCIS (Netherlands)

    Kasimov, Aziz; Zühlke, Christiane; Jungmann, Klaus; Zu Putlitz, Gisbert

    2003-01-01

    We present the results of the first mobility measurements in superfluid helium for negative ions of different elements. Various negative ions like Cl-, F- and I- were produced by laser ablation from targets consisting of NaCl, NaF, NaI, LiF and KCl immersed in a 4He bath. In addition to negative ion

  8. Conscientiousness predicts greater recovery from negative emotion.

    Science.gov (United States)

    Javaras, Kristin N; Schaefer, Stacey M; van Reekum, Carien M; Lapate, Regina C; Greischar, Lawrence L; Bachhuber, David R; Love, Gayle Dienberg; Ryff, Carol D; Davidson, Richard J

    2012-10-01

    Greater levels of conscientiousness have been associated with lower levels of negative affect. We focus on one mechanism through which conscientiousness may decrease negative affect: effective emotion regulation, as reflected by greater recovery from negative stimuli. In 273 adults who were 35-85 years old, we collected self-report measures of personality including conscientiousness and its self-control facet, followed on average 2 years later by psychophysiological measures of emotional reactivity and recovery. Among middle-aged adults (35-65 years old), the measures of conscientiousness and self-control predicted greater recovery from, but not reactivity to, negative emotional stimuli. The effect of conscientiousness and self-control on recovery was not driven by other personality variables or by greater task adherence on the part of high conscientiousness individuals. In addition, the effect was specific to negative emotional stimuli and did not hold for neutral or positive emotional stimuli.

  9. Enhanced Negative Feedback Responses in Remitted Depression

    Science.gov (United States)

    Santesso, Diane L.; Steele, Katherine T.; Bogdan, Ryan; Holmes, Avram J.; Deveney, Christen M.; Meites, Tiffany M.; Pizzagalli, Diego A.

    2011-01-01

    Major depressive disorder (MDD) is characterized by hypersensitivity to negative feedback that might involve frontocingulate dysfunction. MDD subjects exhibit enhanced electrophysiological responses to negative internal (errors) and external (feedback) cues. Whether this dysfunction extends to remitted depressed (RD) subjects with a history of MDD is currently unknown. To address this issue, we examined the feedback-related negativity (FRN) in RD and control subjects using a probabilistic punishment learning task. Despite equivalent behavioral performance, RD subjects showed larger FRNs to negative feedback relative to controls; group differences remained after accounting for residual anxiety and depressive symptoms. The present findings suggest that abnormal responses to negative feedback extend to samples at increased risk for depressive episodes in the absence of current symptoms. PMID:18580576

  10. Universe Models with Negative Bulk Viscosity

    CERN Document Server

    Brevik, Iver

    2013-01-01

    The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting ensemble of ultracold atoms is investigated experimentally and found to correspond to a negative-temperature system since the entropy decreases with increasing energy at the high end of the energy spectrum. As the authors suggest, it would be of interest to investigate whether a suitable generalization of standard cosmological theory could be helpful, in order to elucidate the observed accelerated expansion of the universe usually explained in terms of a positive tensile stress (negative pressure). In the present note we take up this basic idea and investigate a generalization of the standard viscous cosmological theory, not by admitting negative temperatures but instead by letting the bulk viscosity take negative values. Evidently, such an approach breaks standard thermodynamics,...

  11. The entanglement negativity in random spin chains

    CERN Document Server

    Ruggiero, Paola; Calabrese, Pasquale

    2016-01-01

    We investigate the logarithmic negativity in strongly-disordered spin chains in the random-singlet phase. We focus on the spin-1/2 random Heisenberg chain and the random XX chain. We find that for two arbitrary intervals the disorder-averaged negativity and the mutual information are proportional to the number of singlets shared between the two intervals. Using the strong-disorder renormalization group (SDRG), we prove that the negativity of two adjacent intervals grows logarithmically with the intervals length. In particular, the scaling behavior is the same as in conformal field theory, but with a different prefactor. For two disjoint intervals the negativity is given by a universal simple function of the cross ratio, reflecting scale invariance. As a function of the distance of the two intervals, the negativity decays algebraically in contrast with the exponential behavior in clean models. We confirm our predictions using a numerical implementation of the SDRG method. Finally, we also implement DMRG simula...

  12. Study on space charge compensation in negative hydrogen ion beam.

    Science.gov (United States)

    Zhang, A L; Peng, S X; Ren, H T; Zhang, T; Zhang, J F; Xu, Y; Guo, Z Y; Chen, J E

    2016-02-01

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H(+) beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H(-) beam from a 2.45 GHz microwave driven H(-) ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  13. Study on space charge compensation in negative hydrogen ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, A. L.; Chen, J. E. [University of Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Peng, S. X., E-mail: sxpeng@pku.edu.cn; Ren, H. T.; Zhang, T.; Zhang, J. F.; Xu, Y.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

    2016-02-15

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H{sup +} beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H{sup −} beam from a 2.45 GHz microwave driven H{sup −} ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  14. Graphene nanopores as negative differential resistance devices

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Wanzhi; Nguyen, Phuong Duc; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Centre for Neural Engineering, The University of Melbourne, 203 Bouverie Street, Carlton, Victoria 3053, Australia and Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Victoria 3010 (Australia)

    2015-02-07

    We present graphene nanopores as new negative differential resistance (NDR) devices, and study their quantum transport properties using non-equilibrium Green's function and the density functional tight binding method. The proposed device structure is created on intrinsic armchair-edged graphene nanoribbons with uniform widths, where the central scattering region has a nanopore in the interior, and the two ends of the nanoribbon act naturally as connecting electrodes. We show that nitrogen-passivated scattering regions generally result in pronounced NDR properties, while hydrogen-passivated ones do not. This NDR effect occurs at low bias voltages, below 1 V, and achieves extraordinarily high peak-to-valley current ratio, while still attaining very high peak current densities. In addition, very sharp current peaks in the μA range can occur in the I-V curves, and through varying structural dimensions of the proposed structure multiple NDR regions can be realized. These results suggest that the device has promising potential in applications such as high frequency oscillators, memory devices, and fast switches.

  15. Time evolution of negative ion profile in a large cesiated negative ion source applicable to fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, M., E-mail: yoshida.masafumi@jaea.go.jp; Hanada, M.; Kojima, A.; Kashiwagi, M.; Umeda, N.; Hiratsuka, J.; Ichikawa, M.; Watanabe, K. [Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193 (Japan); Grisham, L.R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Tsumori, K.; Kisaki, M. [National Institute for Fusion Science, Toki, Gifu 509-5792 (Japan)

    2016-02-15

    To understand the physics of the cesium (Cs) recycling in the large Cs-seeded negative ion sources relevant to ITER and JT-60SA with ion extraction area of 45-60 cm × 110-120 cm, the time evolution of the negative ion profile was precisely measured in JT-60SA where the ion extraction area is longitudinally segmented into 5. The Cs was seeded from the oven at 180 °C to the ion source. After 1 g of Cs input, surface production of the negative ions appeared only in the central segment where a Cs nozzle was located. Up to 2 g of Cs, the negative ion profile was longitudinally expanded over full ion extraction area. The measured time evolution of the negative ion profile has the similar tendency of distribution of the Cs atoms that is calculated. From the results, it is suggested that Cs atom distribution is correlated with the formation of the negative ion profile.

  16. Numerical Study of Negative-Refractive Index Ferrite Waveguide

    Directory of Open Access Journals (Sweden)

    Mohammed O. Sid-Ahmed

    2012-03-01

    Full Text Available Consider a magnetized ferrite-wire waveguide structure situated between two half free spaces. Ferrites to provide negative permeability and wire array to provide negative permittivity. The structure form left-handed material (LHM with negative refractive index. The transmission of electromagnetic waves through the structure is investigated theoretically. Maxwell's equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell's law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected and transmitted powers of the structure. Numerical results are illustrated to show the effect of frequency, applied magnetic fields, angle of incidence and LHM thickness on the mentioned powers. The analyzed results show that the transmission is very good when the permeability and permittivity of the structure are both simultaneously negative. The frequency band corresponding to this transmission can be tuned by changing the applied magnetic fields. The obtained results are in agreement with the law of conservation of energy. Consider a magnetized ferrite-wire waveguide structure situated between two half free spaces. Ferrites to provide negative permeability and wire array to provide negative permittivity. The structure form left-handed material (LHM with negative refractive index. The transmission of electromagnetic waves through the structure is investigated theoretically. Maxwell's equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell's law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected and transmitted powers of the structure. Numerical results are illustrated to show the effect of frequency, applied magnetic fields, angle of incidence and LHM thickness on the mentioned powers. The analyzed results show that the transmission is very good when the permeability and

  17. Coagulase-negative Staphylococcus isolated from bloodculture: Causes or contaminants?

    Directory of Open Access Journals (Sweden)

    Stojanović Predrag

    2008-01-01

    Full Text Available Introduction According to the results of different investigations, the opinion that isolate of coagulase-negative staphylococci by bloodcultures represents the blood infection in 10-12% patient. The aim of the work was to determine the number of patients with blood infection-sepsa induced coagulase-negative staphylococci isolated by bloodcultures. Material and methods: The research was done at the Institute for Public Health in Niš. The basic group consisted of 56 patients and coagulase-negative staphylococci were segregated form their bloodcultures. The growth of microorganisms was monitored by the computerized apparatus 'Bactec 9120'. Coagulase-negative staphylococci were identified by the standard microbiologic method and Vitec AMS system. Results Eight patients (14.28% were found to have minimum two signs of blood infection. S. epidermis was isolated in four patients. S. saprophyticus was isolated in the patients on hemodialysis with implanted urinary catheter. S. capitis was isolated in the patients with infarctus miocardi. S. auricularis was isolated in child who was administered the immunosuppressive therapy before and during hospitalization due to an acute asthmatic attack. The isolate of S. simulans was cultivated from samples of the patients hospitalized due to the febrile state. Discussion A correct interpretation of coagulase-negative staphylococci findings in bloodcultures is an overriding part of medical treatment. The best laboratory indicators of the presence of coagulase-negative staphylococci in blood would be to segregate those of the same kind from two samples at the same time but from different anatomic sites in the presence of clinical signs of blood infection. Conclusion In the investigation conducted at the Public Health Institute-Nis, we determined that bloodcultures isolated coagulase-negative staphylococci represent the blood infection on 14.28% patient.

  18. Negative HPV screening test predicts low cervical cancer risk better than negative Pap test

    Science.gov (United States)

    Based on a study that included more than 1 million women, investigators at NCI have determined that a negative test for HPV infection compared to a negative Pap test provides greater safety, or assurance, against future risk of cervical cancer.

  19. Negative refraction and Negative refractive index in an optical uniaxial absorbent medium

    OpenAIRE

    Jen, Yi-Jun; Yu, Ching-Wei; Lin, Chin-Te

    2009-01-01

    This work demonstrates the existence of both negative refraction and a negative refractive index in an optical uniaxial absorbent medium that can be characterized by ordinary and extraordinary refractive indices. Negative refraction occurs in any absorbent uniaxial medium if the real part of the extraordinary index is less than its imaginary part. The refractive index is negative when the incident medium is sufficiently dense and the incident angle exceeds a critical angle that is defined here.

  20. Myopic decisions under negative emotions correlate with altered time perception.

    Science.gov (United States)

    Guan, Shuchen; Cheng, Lu; Fan, Ying; Li, Xianchun

    2015-01-01

    Previous studies have obtained inconsistent findings about emotional influence on inter-temporal choice (IC). In the present study, we first examined the effect of temporary emotional priming induced by affective pictures in a trial-to-trial paradigm on IC. The results showed that negative priming resulted in much higher percentages of trials during which smaller-but-sooner reward (SS%) were chosen compared with positive and neutral priming. Next, we attempted to explore the possible mechanisms underlying such emotional effects. When participants performed a time reproduction task, mean reaction times in negative priming condition were significantly shorter than those in the other two emotional contexts, which indicated that negative emotional priming led to overestimation of time. Moreover, such overestimation was negatively correlated with performance in the IC task. In contrast, temporary changes of emotional contexts did not alter performances in a Go/NoGo task (including commission errors and omission errors). In sum, our present findings suggested that myopic decisions under negative emotions were associated with altered time perception but not response inhibition.

  1. Myopic decisions under negative emotions correlate with altered time perception

    Directory of Open Access Journals (Sweden)

    Shuchen eGuan

    2015-04-01

    Full Text Available Previous studies have obtained inconsistent findings about emotional influence on inter-temporal choice. In the present study, we first examined the effect of temporary emotional priming induced by affective pictures in a trial-to-trial paradigm on inter-temporal choice. The results showed that negative priming resulted in much higher percentages of trials during which smaller-but-sooner rewards (SS% were chosen compared with positive and neutral priming. Next, we attempted to explore the possible mechanisms underlying such emotional effects. When participants performed a time reproduction task, mean reaction times in negative priming conditions were significantly shorter than those in the other two emotional contexts, which indicated that negative emotional priming led to overestimation of time. Moreover, such overestimation was negatively correlated with performance in the inter-temporal choice task. In contrast, temporary changes of emotional contexts did not alter performances in a Go/NoGo task (including commission errors and omission errors. In sum, our present findings suggested that myopic decisions under negative emotions were associated with altered time perception but not response inhibition.

  2. Negative refraction in Möbius molecules

    Science.gov (United States)

    Fang, Y. N.; Shen, Yao; Ai, Qing; Sun, C. P.

    2016-10-01

    We theoretically show the negative refraction existing in Möbius molecules. The negative refractive index is induced by the nontrivial topology of the molecules. With the Möbius boundary condition, the effective electromagnetic fields felt by the electron in a Möbius ring is spatially inhomogeneous. In this regard, the DN symmetry is broken in Möbius molecules and thus the magnetic response is induced through the effective magnetic field. Our findings provide an alternative architecture for negative refractive index materials based on the nontrivial topology of Möbius molecules.

  3. Critique of Optical Negative Refraction Superlensing

    CERN Document Server

    Christou, George

    2010-01-01

    Has the ten-year old quest for the optical superlens, based on Veselago's hypothesis of negative refraction, been a chimera? We argue that Pendry's alternative prescription of the silver superlens is nothing more than an application of the natural phenomenon of surface plasmon resonance that occurs in the noble metal films. This phenomenon does not predict the reality of Veselago's negative refractive index materials. We give a simple explanation of how this resonance achieves a field intensity enhancement at the interface of silver and air without involving the concept of negative refraction.

  4. Does Negative Type Characterize the Round Sphere?

    DEFF Research Database (Denmark)

    Kokkendorff, Simon Lyngby

    2007-01-01

    We discuss the measure theoretic metric invariants extent, mean distance and symmetry ratio and their relation to the concept of negative type of a metric space. A conjecture stating that a compact Riemannian manifold with symmetry ratio 1 must be a round sphere, was put forward in a previous paper....... We resolve this conjecture in the class of Riemannian symmetric spaces by showing, that a Riemannian manifold with symmetry ratio 1 must be of negative type and that the only compact Riemannian symmetric spaces of negative type are the round spheres....

  5. Reversible negative photochromic sulfo-substituted spiropyrans

    Science.gov (United States)

    Gao, Hongqi; Guo, Tianqi; Chen, Yun; Kong, Yangyang; Peng, Zhihong

    2016-11-01

    A series of sulfonyl-containing spiropyrans exhibiting negative photochromism were designed and synthesized. The prepared compounds show more stability for the brightly colored state in the dark-adapted than the colorless state under visible irradiation. Negative photochromic properties and fatigue resistance of these compounds in solution were confirmed by UV spectroscopy with time variation. Single-crystal X-ray diffraction analysis, NMR and variable-time absorption spectra studies suggest that the negative photochromism of the compounds involved a ring-opening spiro Csbnd O bond cleavage of the spiropyran followed by an intramolecular proton transfer.

  6. The Modified Negative Decision Number in Graphs

    Directory of Open Access Journals (Sweden)

    Changping Wang

    2011-01-01

    Full Text Available A mapping x:V→{-1,1} is called negative if ∑u∈N[v]x(u≤1 for every v∈V. The maximum of the values of ∑v∈Vx(v taken over all negative mappings x, is called the modified negative decision number and is denoted by βD′(G. In this paper, several sharp upper bounds of this number for a general graph are presented. Exact values of these numbers for cycles, paths, cliques and bicliques are found.

  7. The chameleonic nature of French ni : negative coordination in a negative concord language

    NARCIS (Netherlands)

    Doetjes, Jenny

    2005-01-01

    The main goal of this paper is to defend the claim that ni, the French counterpart of neither and nor is always a negative conjunction which takes part in the negative concord system of French. The interpretation one seems to get for this negative concord ni varies depending on the environment where

  8. The Negative Testing and Negative Generation Effects Are Eliminated by Delay

    Science.gov (United States)

    Mulligan, Neil W.; Peterson, Daniel J.

    2015-01-01

    Although retrieval often enhances subsequent memory (the testing effect), a negative testing effect has recently been documented in which prior retrieval harms later recall compared with restudying. The negative testing effect was predicated on the negative generation effect and the item-specific-relational framework. The present experiments…

  9. [Negative symptoms of schizophrenia: from electrophysiology to electrotherapy].

    Science.gov (United States)

    Micoulaud Franchi, J-A; Quiles, C; Belzeaux, R; Adida, M; Azorin, J-M

    2015-12-01

    The aim of this review of the literature is to summarize the state of the knowledge concerning the relationship between negative symptoms in schizophrenia, electrophysiology and electrotherapy. The scientific literature search of international articles was performed during August and September 2015 using the PubMed electronic database. We used the following MeSH terms: "Negative symptoms", "Schizophrenia", "Electrophysiology", "Neurophysiology", "EEG power", "Alpha rhythm", "Transcranial magnetic stimulation", "Transcranial direct current stimulation", "Electroconvulsive therapy", "Neurofeedback", "Vagus Nerve Stimulation", "Deep Brain Stimulation", and "State dependent". Negative symptoms in schizophrenia are associated with altered activity in prefrontal cortex in functional neuroimaging studies. This is in line with electrophysiological measurements that found a change in EEG spectral power in the alpha frequency band over prefrontal brain regions. The notion of functional hypofrontality has led to hypotheses that electrotherapy applied to the prefrontal cortex may be an effective treatment of negative symptoms in schizophrenia. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) were used to increase cortical activity in schizophrenia and achieve a clinical effect on negative symptoms. Three meta-analyses confirmed, with a moderate effect size, that rTMS is an effective treatment option for negative symptoms in schizophrenia. The two subsequently published prospective multicenter studies, however, found opposite results from each other. Two randomized controlled studies suggested that tDCS is an effective treatment option for negative symptoms. There is no study on the efficacy of neurofeedback, vagal nerve stimulation or deep brain stimulation on negative symptoms in schizophrenia. Additional studies are needed to confirm the efficacy of rTMS and tDCS on negative symptoms in schizophrenia. Influencing factors

  10. Negative phototropism of rice root and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhong(王忠); MO; Yiwei(莫亿伟); QIAN; Shanqin(钱善勤); GU; Yunjie(顾蕴洁)

    2002-01-01

    Some characteristics of the rice (Oryza sativa L.) root were found in the experiment of unilaterally irradiating the roots which were planted in water: (ⅰ) All the seminal roots, adventitious roots and their branched roots bent away from light, and their curvatures ranged from 25° to 60°. The curvature of adventitious root of the higher node was often larger than that of the lower node, and even larger than that of the seminal root. (ⅱ) The negative phototropic bending of the rice root was mainly due to the larger growth increment of root-tip cells of the irradiated side compared with that of the shaded side. (ⅲ) Root cap was the site of light perception. If root cap was shaded while the root was irradiated the root showed no negative phototropism, and the root lost the characteristic of negative phototropism when root cap was divested. Rice root could resume the characteristic of negative phototropism when the new root cap grew up, if the original cells of root cap were well protected while root cap was divested. (ⅳ) The growth increment and curvature of rice root were both influenced by light intensity. Within the range of 0-100μmol@m-2@s-1, the increasing of light intensity resulted in the decreasing of the growth increment and the increasing of the curvature of rice root. (ⅴ) The growth increment and the curvature reached the maximum at 30℃ with the temperature treatment of 10-40℃. (ⅵ) Blue-violet light could prominently induce the negative phototropism of rice root, while red light had no such effect. (ⅶ) The auxin (IAA) in the solution, as a very prominent influencing factor, inhibited the growth, the negative phototropism and the gravitropism of rice root when the concentration of IAA increased. The response of negative phototropism of rice root disappeared when the concentration of IAA was above 10 mg@L-1.

  11. Outcome Following a Negative CT Angiogram for Gastrointestinal Hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Victoria, E-mail: drvictoriac@gmail.com; Tse, Donald, E-mail: donald.tse@gmail.com; Dixon, Shaheen, E-mail: shaheen7noorani@gmail.com [John Radcliffe Hospital, Department of Radiology, Level 2 (United Kingdom); Shrivastava, Vivek, E-mail: vivshriv@yahoo.com [Hull Royal Infirmary, Department of Radiology (United Kingdom); Bratby, Mark, E-mail: mark.bratby@ouh.nhs.uk; Anthony, Suzie, E-mail: suzie.anthony@ouh.nhs.uk; Patel, Rafiuddin, E-mail: rafiuddin.patel@ouh.nhs.uk; Tapping, Charles, E-mail: charles.tapping@ouh.nhs.uk; Uberoi, Raman, E-mail: raman.uberoi@orh.nhs.uk [John Radcliffe Hospital, Department of Radiology, Level 2 (United Kingdom)

    2015-04-15

    ObjectiveThis study was designed to evaluate the role of a negative computed tomography angiogram (CTA) in patients who present with gastrointestinal (GI) hemorrhage.MethodsA review of all patients who had CTAs for GI hemorrhage over an 8-year period from January 2005 to December 2012 was performed. Data for patient demographics, location of hemorrhage, hemodynamic stability, and details of angiograms and/or the embolization procedure were obtained from the CRIS/PACS database, interventional radiology database, secure electronic medical records, and patient’s clinical notes.ResultsA total of 180 patients had 202 CTAs during the 8-year period: 87 CTAs were performed for upper GI hemorrhage (18 positive for active bleeding, 69 negative) and 115 for lower GI hemorrhage (37 positive for active bleeding, 78 negative); 58.7 % (37/63) of patients with upper GI bleed and 77.4 % (48/62) of patients with lower GI bleed who had an initial negative CTA did not rebleed without the need for radiological or surgical intervention. This difference was statistically significant (p = 0.04). The relative risk of rebleeding, following a negative CTA, in lower GI bleeding versus upper GI bleeding patients is 0.55 (95 % confidence interval 0.32–0.95).ConclusionsPatients with upper GI bleed who had negative CTAs usually require further intervention to stop the bleeding. In contrast, most patients presenting with lower GI hemorrhage who had a negative first CTA were less likely to rebleed.

  12. Tunnelling with a negative cosmological constant

    Science.gov (United States)

    Gibbons, G. W.

    1996-02-01

    The point of this paper is to see what light new results in hyperbolic geometry may throw on gravitational entropy and whether gravitational entropy is relevant for the quantum origin of the universe. We introduce some new gravitational instantons which mediate the birth from nothing of closed universes containing wormholes and suggest that they may contribute to the density matrix of the universe. We also discuss the connection between their gravitational action and the topological and volumetric entropies introduced in hyperbolic geometry. These coincide for hyperbolic 4-manifolds, and increase with increasing topological complexity of the 4-manifold. We raise the question of whether the action also increases with the topological complexity of the initial 3-geometry, measured either by its 3-volume or its Matveev complexity. We point out, in distinction to the non-supergravity case, that universes with domains of negative cosmological constant separated by supergravity domain walls cannot be born from nothing. Finally we point out that our wormholes provide examples of the type of Perpetual Motion machines envisaged by Frolov and Novikov.

  13. Threshold photodetachment spectroscopy of negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Kitsopoulos, T.N.

    1991-12-01

    This thesis is concerned with the development and application of high resolution threshold photodetachment spectroscopy of negative ions. Chapter I deals with the principles of our photodetachment technique, and in chapter II a detailed description of the apparatus is presented. The threshold photodetachment spectra of I{sup {minus}}, and SH{sup {minus}}, presented in the last sections of chapter II, indicated that a resolution of 3 cm{sup {minus}1} can be achieved using our technique. In chapter III the threshold photodetachment spectroscopy study of the transition state region of I + HI and I + Di reactions is discussed. Our technique probes the transition state region directly, and the results of our study are the first unambiguous observations of reactive resonances in a chemical reaction. Chapters IV, V and VI are concerned with the spectroscopy of small silicon and carbon clusters. From our spectra we were able to assign electronic state energies and vibrational frequencies for the low lying electronics states of Si{sub n} (n=2,3,4), C{sub 5} and their corresponding anions.

  14. Decreasing seagrass density negatively influences associated fauna.

    Science.gov (United States)

    McCloskey, Rosemary M; Unsworth, Richard K F

    2015-01-01

    Seagrass meadows globally are disappearing at a rapid rate with physical disturbances being one of the major drivers of this habitat loss. Disturbance of seagrass can lead to fragmentation, a reduction in shoot density, canopy height and coverage, and potentially permanent loss of habitat. Despite being such a widespread issue, knowledge of how such small scale change affects the spatial distribution and abundances of motile fauna remains limited. The present study investigated fish and macro faunal community response patterns to a range of habitat variables (shoot length, cover and density), including individual species habitat preferences within a disturbed and patchy intertidal seagrass meadow. Multivariate analysis showed a measurable effect of variable seagrass cover on the abundance and distribution of the fauna, with species specific preferences to both high and low seagrass cover seagrass. The faunal community composition varied significantly with increasing/decreasing cover. The faunal species composition of low cover seagrass was more similar to sandy control plots than to higher cover seagrass. Shannon Wiener Diversity (H') and species richness was significantly higher in high cover seagrass than in low cover seagrass, indicating increasing habitat value as density increases. The results of this study underline how the impacts of small scale disturbances from factors such as anchor damage, boat moorings and intertidal vehicle use on seagrass meadows that reduce shoot density and cover can impact upon associated fauna. These impacts have negative consequences for the delivery of ecosystem services such as the provision of nursery habitat.

  15. Microwave gain medium with negative refractive index.

    Science.gov (United States)

    Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

    2014-12-19

    Artificial effective media are attractive because of the fantastic applications they may enable, such as super lensing and electromagnetic invisibility. However, the inevitable loss due to their strongly dispersive nature is one of the fundamental challenges preventing such applications from becoming a reality. In this study, we demonstrate an effective gain medium based on negative resistance, to overcompensate the loss of a conventional passive metamaterial, meanwhile keeping its original negative-index property. Energy conservation-based theory, full-wave simulation and experimental measurement show that a fabricated sample consisting of conventional sub-wavelength building blocks with embedded microwave tunnel diodes exhibits a band-limited Lorentzian dispersion simultaneously with a negative refractive index and a net gain. Our work provides experimental evidence to the assertion that a stable net gain in negative-index gain medium is achievable, proposing a potential solution for the critical challenge current metamateiral technology faces in practical applications.

  16. Microwave gain medium with negative refractive index

    Science.gov (United States)

    Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

    2014-12-01

    Artificial effective media are attractive because of the fantastic applications they may enable, such as super lensing and electromagnetic invisibility. However, the inevitable loss due to their strongly dispersive nature is one of the fundamental challenges preventing such applications from becoming a reality. In this study, we demonstrate an effective gain medium based on negative resistance, to overcompensate the loss of a conventional passive metamaterial, meanwhile keeping its original negative-index property. Energy conservation-based theory, full-wave simulation and experimental measurement show that a fabricated sample consisting of conventional sub-wavelength building blocks with embedded microwave tunnel diodes exhibits a band-limited Lorentzian dispersion simultaneously with a negative refractive index and a net gain. Our work provides experimental evidence to the assertion that a stable net gain in negative-index gain medium is achievable, proposing a potential solution for the critical challenge current metamateiral technology faces in practical applications.

  17. Heart Disease Linked to Anxiety, Negative Feelings

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163702.html Heart Disease Linked to Anxiety, Negative Feelings And that's especially ... Feb. 21, 2017 (HealthDay News) -- People with mild heart disease are more likely to say they have poorer ...

  18. Negation of the Self in Wuthering Heights

    Institute of Scientific and Technical Information of China (English)

    李敏

    2015-01-01

    Emily Bronte created one of the greatest novels in19th British literary history---Wuthering Heights.Through this works,the writers tries to severely criticize the feature in western civilization:negation of the self.

  19. Negation of the Self in Wuthering Heights

    Institute of Scientific and Technical Information of China (English)

    李敏

    2015-01-01

    Emily Bronte created one of the greatest novels in 19th British literary history---Wuthering Heights.Through this works,the writers tries to severely criticize the feature in western civilization: negation of the self.

  20. Bubbles in the negative pressure domain

    Science.gov (United States)

    Maslov, V. P.

    2015-10-01

    We determine the extension of an ideal liquid by "thermodynamic forces," that is, forces related to entropy growth. We show that the negative pressure corresponds to the case of at most two degrees of freedom.

  1. Critique of optical negative refraction superlensing

    OpenAIRE

    Christou, George; Mias, Christos

    2011-01-01

    Has the ten-year old quest for the optical superlens, based on Veselago's hypothesis of negative refraction, been a chimera? We argue that Pendry's alternative prescription of the silver superlens is nothing more than an application of the natural phenomenon of surface plasmon resonance that occurs in the noble metal films. This phenomenon does not predict the reality of Veselago's negative refractive index materials. We give a simple explanation of how this resonance achieves a field intensi...

  2. Negative Link Prediction in Social Media

    OpenAIRE

    Tang, Jiliang; Chang, Shiyu; Aggarwal, Charu; Liu, Huan

    2014-01-01

    Signed network analysis has attracted increasing attention in recent years. This is in part because research on signed network analysis suggests that negative links have added value in the analytical process. A major impediment in their effective use is that most social media sites do not enable users to specify them explicitly. In other words, a gap exists between the importance of negative links and their availability in real data sets. Therefore, it is natural to explore whether one can pr...

  3. Waves in geomaterials exhibiting negative stiffness behaviour

    Science.gov (United States)

    Esin, Maxim; Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Negative stiffness denotes the type of material behaviour when the force applied to the body decreases the body's deformation increases. Some geomaterials, for instance, rocks, demonstrate behaviour of this type at certain loads: during the compression tests the loading curves exhibit descending branch (post-peak softening). One of the possible mechanisms of the negative stiffness appearance in geomaterials is rotation of non-spherical grains. It is important to emphasize that in this case the descending branch may be reversible given that the testing machine is stiff enough (in general case it means an importance of boundary conditions). Existence of geomaterials with a negative modulus associated with rotations may have significant importance. In particular, important is understanding of the wave propagation in such materials. We study the stability of geomaterials with negative stiffness inclusions and wave propagation in it using two approaches: Cosserat continuum and discrete mass-spring models. In both cases we consider the rotational degrees of freedom in addition to the conventional translational ones. We show that despite non positiveness of the energy the materials with negative stiffness elements can be stable if certain conditions are met. In the case of Cosserat continuum the Cosserat shear modulus (the modulus relating the non-symmetrical part of shear stress and internal rotations) is allowed to assume negative values as long as its value does not exceed the value of the standard (positive) shear modulus. In the case of discrete mass-spring systems (with translational and rotational springs) the concentration of negative stiffness springs and the absolute values of negative spring stiffness are limited. The critical concentration when the system loses stability and the amplitude of the oscillations tends to infinity is equal to 1/2 and 3/5 for two- and three-dimensional cases respectively.

  4. Negative entropy and information in quantum mechanics

    OpenAIRE

    Cerf, N. J.; Adami, C.

    1995-01-01

    A framework for a quantum mechanical information theory is introduced that is based entirely on density operators, and gives rise to a unified description of classical correlation and quantum entanglement. Unlike in classical (Shannon) information theory, quantum (von Neumann) conditional entropies can be negative when considering quantum entangled systems, a fact related to quantum non-separability. The possibility that negative (virtual) information can be carried by entangled particles sug...

  5. Quantum Confinement and Negative Heat Capacity

    OpenAIRE

    Serra, Pablo; Carignano, Marcelo; Alharbi, Fahhad; Kais, Sabre

    2013-01-01

    Thermodynamics dictates that the specific heat of a system is strictly non-negative. However, in finite classical systems there are well known theoretical and experimental cases where this rule is violated, in particular finite atomic clusters. Here, we show for the first time that negative heat capacity can also occur in finite quantum systems. The physical scenario on which this effect might be experimentally observed is discussed. Observing such an effect might lead to the design of new li...

  6. Finite Metric Spaces of Strictly Negative Type

    DEFF Research Database (Denmark)

    Hjorth, Poul; Lisonek, P.; Markvorsen, Steen

    1998-01-01

    We prove that, if a finite metric space is of strictly negative type, then its transfinite diameter is uniquely realized by the infinite extender (load vector). Finite metric spaces that have this property include all spaces on two, three, or four points, all trees, and all finite subspaces of Eu...... by Kelly, we conjecture that all finite subspaces of hyperbolic spaces are hypermetric and regular, and hence of strictly negative type. (C) 1998 Elsevier Science Inc....

  7. Negative capacitance in multidomain ferroelectric superlattices

    Science.gov (United States)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk'Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric-dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  8. Motion of Inertial Observers Through Negative Energy

    CERN Document Server

    Ford, L H; Roman, Thomas A.

    1993-01-01

    Recent research has indicated that negative energy fluxes due to quantum coherence effects obey uncertainty principle-type inequalities of the form $|\\Delta E|\\,{\\Delta \\tau} \\lprox 1\\,$. Here $|\\Delta E|$ is the magnitude of the negative energy which is transmitted on a timescale $\\Delta \\tau$. Our main focus in this paper is on negative energy fluxes which are produced by the motion of observers through static negative energy regions. We find that although a quantum inequality appears to be satisfied for radially moving geodesic observers in two and four-dimensional black hole spacetimes, an observer orbiting close to a black hole will see a constant negative energy flux. In addition, we show that inertial observers moving slowly through the Casimir vacuum can achieve arbitrarily large violations of the inequality. It seems likely that, in general, these types of negative energy fluxes are not constrained by inequalities on the magnitude and duration of the flux. We construct a model of a non-gravitational ...

  9. Tailoring graphene to achieve negative Poisson's ratio properties.

    Science.gov (United States)

    Grima, Joseph N; Winczewski, Szymon; Mizzi, Luke; Grech, Michael C; Cauchi, Reuben; Gatt, Ruben; Attard, Daphne; Wojciechowski, Krzysztof W; Rybicki, Jarosław

    2015-02-25

    Graphene can be made auxetic through the introduction of vacancy defects. This results in the thinnest negative Poisson's ratio material at ambient conditions known so far, an effect achieved via a nanoscale de-wrinkling mechanism that mimics the behavior at the macroscale exhibited by a crumpled sheet of paper when stretched.

  10. Radiative decays of negative parity heavy baryons in QCD

    CERN Document Server

    Agamaliev, A K; Savcı, M

    2016-01-01

    The transition form factors responsible for the radiative $\\Sigma_Q \\to \\Lambda_Q \\gamma$ and $\\Xi_Q^\\prime \\to \\Xi \\gamma$ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the radiative transitions are calculated using the obtained results of the form factors.

  11. A NEGATIVE ANSWER TO A PROBLEM OF FREMLIN AND MENDOZA

    Institute of Scientific and Technical Information of China (English)

    Ye Guoju; Stefan Schwabik

    2007-01-01

    This article studies some convergence results for the McShane integral of functions mapping the interval [0, 1] into a Banach space X from the point of view of an open problem proposed by D.H.Fremlin and J. Mendoza in [2], also the anthors give a negative answer to this open problem.

  12. Negative Integer Understanding: Characterizing First Graders' Mental Models

    Science.gov (United States)

    Bofferding, Laura

    2014-01-01

    This article presents results of a research study. Sixty-one first graders' responses to interview questions about negative integer values and order and directed magnitudes were examined to characterize the students' mental models. The models reveal that initially, students overrelied on various combinations of whole-number principles as…

  13. Capacity recovery after storage negatively precharged nickel hydrogen cells

    Science.gov (United States)

    Lowery, John E.

    1993-01-01

    Tests were conducted to investigate the recovery of capacity lost during open circuit storage of negatively precharged nickel hydrogen batteries. Four Eagle Picher RNH-90-3 cells were used in the tests. Recovery procedures and test results are presented in outline and graphic form.

  14. The Teaching of Numerical Extensions: The Case of Negative Numbers.

    Science.gov (United States)

    Bruno, Alicia; Martinon, Antonio

    1999-01-01

    Presents some results of a study on teaching negative numbers. Focuses on the identification of addition and subtraction, the use of the number line, additive problem solving, and the possibility of following several sequences of numerical extensions. Indicates the importance of previous ideas on positive numbers and how these ideas influence the…

  15. A multiple relevance feedback strategy with positive and negative models.

    Directory of Open Access Journals (Sweden)

    Yunlong Ma

    Full Text Available A commonly used strategy to improve search accuracy is through feedback techniques. Most existing work on feedback relies on positive information, and has been extensively studied in information retrieval. However, when a query topic is difficult and the results from the first-pass retrieval are very poor, it is impossible to extract enough useful terms from a few positive documents. Therefore, the positive feedback strategy is incapable to improve retrieval in this situation. Contrarily, there is a relatively large number of negative documents in the top of the result list, and it has been confirmed that negative feedback strategy is an important and useful way for adapting this scenario by several recent studies. In this paper, we consider a scenario when the search results are so poor that there are at most three relevant documents in the top twenty documents. Then, we conduct a novel study of multiple strategies for relevance feedback using both positive and negative examples from the first-pass retrieval to improve retrieval accuracy for such difficult queries. Experimental results on these TREC collections show that the proposed language model based multiple model feedback method which is generally more effective than both the baseline method and the methods using only positive or negative model.

  16. Distinguishing between Binomial, Hypergeometric and Negative Binomial Distributions

    Science.gov (United States)

    Wroughton, Jacqueline; Cole, Tarah

    2013-01-01

    Recognizing the differences between three discrete distributions (Binomial, Hypergeometric and Negative Binomial) can be challenging for students. We present an activity designed to help students differentiate among these distributions. In addition, we present assessment results in the form of pre- and post-tests that were designed to assess the…

  17. Sensitivity of negative subsequent memory and task-negative effects to age and associative memory performance.

    Science.gov (United States)

    de Chastelaine, Marianne; Mattson, Julia T; Wang, Tracy H; Donley, Brian E; Rugg, Michael D

    2015-07-01

    The present fMRI experiment employed associative recognition to investigate the relationships between age and encoding-related negative subsequent memory effects and task-negative effects. Young, middle-aged and older adults (total n=136) were scanned while they made relational judgments on visually presented word pairs. In a later memory test, the participants made associative recognition judgments on studied, rearranged (items studied on different trials) and new pairs. Several regions, mostly localized to the default mode network, demonstrated negative subsequent memory effects in an across age-group analysis. All but one of these regions also demonstrated task-negative effects, although there was no correlation between the size of the respective effects. Whereas negative subsequent memory effects demonstrated a graded attenuation with age, task-negative effects declined markedly between the young and the middle-aged group, but showed no further reduction in the older group. Negative subsequent memory effects did not correlate with memory performance within any age group. By contrast, in the older group only, task-negative effects predicted later memory performance. The findings demonstrate that negative subsequent memory and task-negative effects depend on dissociable neural mechanisms and likely reflect distinct cognitive processes. The relationship between task-negative effects and memory performance in the older group might reflect the sensitivity of these effects to variations in amount of age-related neuropathology. This article is part of a Special Issue entitled SI: Memory.

  18. Overcoming losses with gain in a negative refractive index metamaterial.

    Science.gov (United States)

    Wuestner, Sebastian; Pusch, Andreas; Tsakmakidis, Kosmas L; Hamm, Joachim M; Hess, Ortwin

    2010-09-17

    On the basis of a full-vectorial three-dimensional Maxwell-Bloch approach we investigate the possibility of using gain to overcome losses in a negative refractive index fishnet metamaterial. We show that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the nonbianisotropic metamaterial becomes amplifying. In that region both the real and the imaginary part of the effective refractive index become simultaneously negative and the figure of merit diverges at two distinct frequency points.

  19. Broadband negative refractive index obtained by plasmonic hybridization in metamaterials

    Science.gov (United States)

    Nguyen, Hien T.; Bui, Tung S.; Yan, Sen; Vandenbosch, Guy A. E.; Lievens, Peter; Vu, Lam D.; Janssens, Ewald

    2016-11-01

    We experimentally demonstrate a broadband negative refractive index (NRI) behavior in combined dimer and fishnet dimer metamaterials operating in the GHz frequency range. The observations can be well explained by a hybridization model and are in agreement with numerical modelling results. Hybridization of the magnetic resonances is obtained by reducing the distance between the layers in the dimer structures. A ratio of the double negative refractive index bandwidth to operational frequency of approximately 10% was achieved in the fishnet dimer. The applicable frequency range of the broadband NRI was shown to scale with the size of the structures from the microwave to the far infrared.

  20. Effects of Positive and Negative Consequences on Altruistic Behavior

    Directory of Open Access Journals (Sweden)

    Virginia Pacheco

    2008-05-01

    Full Text Available To evaluate the effects of different types of consequences (positive and negative for helping and not helping, was used a preparation in which each participant had to solve arithmetical operations of different complexity to accumulate interchangeable points by a compact disc. During the task the participants could accept or refuse themselves to help a virtual peer who could not accumulate his points. The results show that participants did prefer to help their virtual peer only when negative consequences for not helping were presented. Even though the quality of the help for peer wasinferior compared to the execution shown in the participant own task.

  1. Negative price-image effects of appealing store architecture

    DEFF Research Database (Denmark)

    Zielke, Stephan; Toporowski, Waldemar

    2012-01-01

    Retailers often worry about the negative effects of appealing exterior architecture on their store's price image, especially the price-level perception and the ease of price evaluation. Findings from prior laboratory experiments support these concerns, while field studies find no such effects....... The present study explains this inconsistency by analyzing the moderating effects of price and retail brand information available to customers in real shopping situations. The results show that negative effects of appealing exterior architecture do not exist when retail brand information is available...

  2. Negative edge plasma currents in the SINP tokamak

    Indian Academy of Sciences (India)

    Ramesh Narayanan; A N Sekar Iyengar

    2011-12-01

    A tokamak plasma discharge having an increase in duration accompanied with enhanced runaway electron flux has been experimentally studied in this paper. The discharges have been obtained by controlling the applied vertical magnetic field ($B^{\\text{appl}}_v$) to below a critical value. Such discharges have been observed to have ‘negative edge plasma currents’, detected using an internal Rogowskii coil (IRC). We have tried to correlate the runaway behaviour with the negative edge plasma currents and have explained that these observations are a result of beam plasma instabilities.

  3. Negative serology: could exclude the diagnosis of brucellosis?

    Science.gov (United States)

    Çelik, Aygul Dogan; Yulugkural, Zerrin; Kilincer, Cumhur; Hamamcioglu, Mustafa Kemal; Kuloglu, Figen; Akata, Filiz

    2012-08-01

    Two cases of brucellar spondylodiscitis of the lumbar area were presented. Although both cases showed typical radiological changes, serological tests could not detect Brucella agglutinating antibodies. One of the patients was bacteremic and Brucella spp. was identified from blood culture. In the second patient needle biopsy was required for definite diagnosis. Although small, serologic tests have a certain rate of false negative results in brucellosis. Thus, a negative serology should not exclude the diagnosis of brucellosis, as it is demonstrated in the current cases.

  4. Neuropsychology of reward learning and negative symptoms in schizophrenia.

    Science.gov (United States)

    Nestor, Paul G; Choate, Victoria; Niznikiewicz, Margaret; Levitt, James J; Shenton, Martha E; McCarley, Robert W

    2014-11-01

    We used the Iowa Gambling Test (IGT) to examine the relationship of reward learning to both neuropsychological functioning and symptom formation in 65 individuals with schizophrenia. Results indicated that compared to controls, participants with schizophrenia showed significantly reduced reward learning, which in turn correlated with reduced intelligence, memory and executive function, and negative symptoms. The current findings suggested that a disease-related disturbance in reward learning may underlie both cognitive and motivation deficits, as expressed by neuropsychological impairment and negative symptoms in schizophrenia.

  5. Atypical false negative results of {sup 67}Ga scintigraphy and {sup 18}F-F.D.G. PET-CT in a patient with sarcoidosis and bilateral breast cancer; Resultats atypiques et faux-negatifs de la scintigraphie au {sup 67}Ga et de la TEP-TDM au {sup 18}F-FDG chez une patiente avec sarcoidose et cancer du sein bilateral

    Energy Technology Data Exchange (ETDEWEB)

    Keomany, J.; Imperiale, A.; Constantinesco, A. [Hopital de Hautepierre, Hopitaux Universitaires de Strasbourg, Service de Biophysique et de Medecine Nucleaire, 67 - Strasbourg (France); Thiriat, S. [Hopital de Hautepierre, Hopitaux Universitaires de Strasbourg, Service de Radiologie, 67 - Strasbourg (France); Braun, J.J. [Hopital de Hautepierre, Hopitaux Universitaires de Strasbourg, Service d' ORL, 67 - Strasbourg (France)

    2009-12-15

    We describe the case of a patient with biopsy proven sino-nasal sarcoidosis and a bilateral breast cancer that was unknown at the time of {sup 67}Ga scintigraphy and {sup 18}F-F.D.G. PET-CT. {sup 67}Ga scintigraphy showed low sensibility in the assessment of sarcoidosis localizations. Conversely, multiple foci of intense {sup 18}F-F.D.G. uptake were assessed suggesting the presence of active granulomatous disease in sino-nasal region, rhino pharynx, skin and several peripheral lymphadenopathy, which were not previously detected by conventional evaluation. On the other hand, an atypical focal accumulation of {sup 67}Ga uptake was showed in right breast parenchyma, proving to be a grade III infiltrating canalar carcinoma coexistent with pleomorphic type, without axillary metastatic lymphadenopathy. Surprisingly, no {sup 18}F-F.D.G. uptake abnormalities were detected in the right breast in correspondence of {sup 67}Ga pathological uptake. The whole of these results is discussed according to histological nature of the lesions and the data of the literature. (authors)

  6. Negative emotion boosts quality of visual working memory representation.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2016-08-01

    Negative emotion impacts a variety of cognitive processes, including working memory (WM). The present study investigated whether negative emotion modulated WM capacity (quantity) or resolution (quality), 2 independent limits on WM storage. In Experiment 1, observers tried to remember several colors over 1-s delay and then recalled the color of a randomly picked memory item by clicking a best-matching color on a continuous color wheel. On each trial, before the visual WM task, 1 of 3 emotion conditions (negative, neutral, or positive) was induced by having observers to rate the valence of an International Affective Picture System image. Visual WM under negative emotion showed enhanced resolution compared with neutral and positive conditions, whereas the number of retained representations was comparable across the 3 emotion conditions. These effects were generalized to closed-contour shapes in Experiment 2. To isolate the locus of these effects, Experiment 3 adopted an iconic memory version of the color recall task by eliminating the 1-s retention interval. No significant change in the quantity or quality of iconic memory was observed, suggesting that the resolution effects in the first 2 experiments were critically dependent on the need to retain memory representations over a short period of time. Taken together, these results suggest that negative emotion selectively boosts visual WM quality, supporting the dissociable nature quantitative and qualitative aspects of visual WM representation. (PsycINFO Database Record

  7. Tissue fixation and autoradiographic negative chemography in rat oral epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Prime, S.S.; MacDonald, D.G. (Glasgow Dental Hospital (UK))

    1983-01-01

    The effect of routine methods of tissue fixation on autoradiographic negative chemography was investigated in adult rat palatal and tongue epithelia following the incorporation of /sup 3/H thymidine in vivo. Tissues fixed in formalin or Bouin's without acetic acid demonstrated more negative chemography than those fixed in Bouin's fluid, formol-acetic-methanol or Carnoy's solutions. These findings were associated with the lowest silver grain counts per nucleus in the formalin fixed tissues, low grain counts in tissues fixed in Bouin's without acetic acid, but the addition of acetic acid to make complete Bouin's fluid gave results similar to those following fixation with Carnoy's solution. The highest silver grain counts were obtained with tissues fixed in formol-acetic-methanol. The relationship between negative chemography and the labelling indices of tissues was unclear except where the negative chemographic effects were severe. Formalin fixed tissues showed the maximum negative chemographic effects and the lowest labelling indices. Carnoy's solution appeared to be the fixative of choice for cell kinetic studies of oral epithelium.

  8. Effects of CEOs’ Negative Traits on Corporate Social Responsibility

    Directory of Open Access Journals (Sweden)

    Jae Kyu Myung

    2017-04-01

    Full Text Available The dark triad, composed of Machiavellianism, psychopathy and narcissism, refers to negative personality traits, which may influence business processes. While negative traits could be an important factor explaining the relationship between a CEO’s immoral and unethical behavior and corporate social responsibility (CSR, there has been minimal research focusing on this relationship. This paper thus attempts to investigate how a CEO exhibiting these negative traits affects CSR, and if an employee’s perception of ethics and social responsibility would mediate the relationship. In addition, this paper considers the moderating effects of an individual performance-based compensation system (IPBCS between employee’s CSR perception and CSR activities. The data are collected through a survey conducted on 165 employees (companies in twelve industries. The regression result indicates an inverse relationship between the negative traits of a CEO and an employee’s perception of ethics and social responsibility and CSR activities, and the mediating effect of the perception in the relationship between the negative traits and CSR activities. It also indicates that an IPBCS moderates the relationship between CSR perception and activities. Implications for the study, future research directions, and management approach are discussed.

  9. Negative Feedback, Linearity and Parameter Invariance in Linear Electronics

    CERN Document Server

    Costa, Luciano da F; Comin, Cesar H

    2016-01-01

    Negative feedback is a powerful approach capable of improving several aspects of a system. In linear electronics, it has been critical for allowing invariance to device properties. Negative feedback is also known to enhance linearity in amplification, which is one of the most important foundations of linear electronics. At the same time, thousands of transistors types have been made available, suggesting that these devices, in addition to their known variability of parameters, have distinguishing properties. The current work reports a systematic approach to quantifying the potential of negative feedback, with respect to bipolar transistors, as a means to providing device invariance and linearity. Several methods, including concepts from multivariate statistics and complex systems, are applied at the theoretical as well as experimental levels, and a number of interesting results are obtained and discussed. For instance, it has been verified that the transistors types indeed have well-defined characteristics wh...

  10. Topological entanglement negativity in Chern-Simons theories

    CERN Document Server

    Wen, Xueda; Ryu, Shinsei

    2016-01-01

    We study the topological entanglement negativity between two spatial regions in (2+1)-dimensional Chern-Simons gauge theories by using the replica trick and the surgery method. For a bipartitioned or tripartitioned spatial manifold, we show how the topological entanglement negativity depends on the presence of quasiparticles and the choice of ground states. In particular, for two adjacent non-contractible regions on a tripartitioned torus, the entanglement negativity provides a simple way to distinguish Abelian and non-Abelian theories. Our method applies to a Chern-Simons gauge theory defined on an arbitrary oriented (2+1)-dimensional spacetime manifold. Our results agree with the edge theory approach in a recent work (X. Wen, S. Matsuura and S. Ryu, arXiv:1603.08534).

  11. Negative Affectivity is Common to Pediatric Behavioral Health Problems

    Directory of Open Access Journals (Sweden)

    Simone Behar

    2014-10-01

    Full Text Available A significant number of youth in the United States experience mental illness; within these youth, comorbidity is considered the rule, not the exception. Rather than treat each disorder distinctly, recent research examines common psychopathological processes shaping various presenting problems to simultaneously target deficits and excesses. Contemporary research hypothesizes that negative affectivity pervades multiple psychiatric problems in youth. The present study sought to examine negative affectivity in an intent-to-treat sample of young patients presenting at an outpatient clinic in an academic medical center. Young patients (n=54 with internalizing disorders, externalizing disorders, or both completed the Children’s Depression Inventory and the Screen for Childhood Anxiety and Related Emotional Disorders. MANOVA results indicated no significant difference between the groups. Additionally, no gender differences were found. Findings suggest negative affectivity is a core feature of psychopathology in general, and thus a valuable focus for transdiagnostic treatments.

  12. Micro-architected Composite Lattices with Tunable Negative Thermal Expansions

    Science.gov (United States)

    Wang, Qiming

    Solid materials with minimum or negative thermal expansion (NTE) have broad applications, from dental fillings to thermal-sensitive precision instruments. Previous studies on NTE structures were mostly focused on theoretically design and 2D experimental demonstrations. Here, aided with multimaterial projection micro-stereolithography, we experimentally fabricate multi-material composite lattices that exhibit significant negative thermal expansion in three directions and over a large range of temperature variations. The negative thermal expansion is induced by the structural interaction of material components with distinct thermal expansion coefficients. The NTE performance can be tuned over a large range by varying the thermal expansion coefficient difference between constituent beams and geometrical arrangement. Our experimental results match qualitatively with a simple scaling law and quantitatively consistently with computational models.

  13. Acoustic metamaterial with negative mass density in water

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huaijun; Zhai, Shilong; Ding, Changlin; Luo, Chunrong; Zhao, Xiaopeng, E-mail: xpzhao@nwpu.edu.cn [Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710129 (China)

    2015-09-07

    A two-dimensional (2D) acoustic metamaterial (AM) with negative effective mass density in water is designed by periodically arranging hollow tube “meta-atoms.” Experimental and simulated results demonstrate that transmission dips accompanied with inverse phases are presented in the transmission spectra of the 2D AM at the ultrasonic frequency band. Effective parameters extracted from the experimental measured transmission and reflection coefficients of the 2D AM show that the effective mass density and refractive index are negative near the dip frequency range of 35.31–35.94 kHz. The simulation also shows the negative response in the 2D AM. Due to the excellent properties, the 2D AM is appealing for the potential applications in areas such as subwavelength imaging, ultrasonic cloaking in water, and so on.

  14. Positive and negative caregiver experiences in first-episode psychosis

    DEFF Research Database (Denmark)

    Jansen, Jens Einar; Lysaker, Paul H.; Harder, Susanne

    2014-01-01

    Objectives While caregivers of persons with first-episode psychosis often report a range of negative experiences, little is known about what psychological factors are involved. The aim of this study was to examine how caregivers' general wellbeing, emotional overinvolvement and metacognition...... influenced their reports of both positive and negative caregiving experiences. Design A prospective consecutive cross-sectional study. Methods Forty caregivers of patients with first-episode psychosis were interviewed using semi-structured interview and questionnaires. Results Greater levels of distress...... metacognitive capacity does not necessarily alleviate the suffering and distress, which is a healthy and normal reaction to having a close one suffering from psychosis. But it might help broaden the perspective, allowing for both negative and positive experiences. Clinical implications in terms of expanding...

  15. Negative feedback effects on star formation history and cosmic reionization

    CERN Document Server

    Wang, Lei; Xiang, Shouping; Yuan, Ye-Fei

    2008-01-01

    After considering the effects of negative feedback on the process of star formation, we explore the relationship between star formation process and the associated feedback, by investigating how the mechanical feedback from supernovae(SNe) and radiative feedback from luminous objects regulate the star formation rate and therefore affect the cosmic reionization.Based on our present knowledge of the negative feedback theory and some numerical simulations, we construct an analytic model in the framework of the Lambda cold dark matter model. In certain parameter regions, our model can explain some observational results properly. In large halos(T_vir>10000 K), both mechanical and radiative feedback have a similar behavior: the relative strength of negative feedback reduces as the redshift decreases. In contrast, in small halos (T_vir<10000 K$) that are thought to breed the first stars at early time, the radiative feedback gets stronger when the redshift decreases. And the star formation rate in these small halos...

  16. Topological entanglement negativity in Chern-Simons theories

    Science.gov (United States)

    Wen, Xueda; Chang, Po-Yao; Ryu, Shinsei

    2016-09-01

    We study the topological entanglement negativity between two spatial regions in (2+1)-dimensional Chern-Simons gauge theories by using the replica trick and the surgery method. For a bipartitioned or tripartitioned spatial manifold, we show how the topological entanglement negativity depends on the presence of quasiparticles and the choice of ground states. In particular, for two adjacent non-contractible regions on a tripartitioned torus, the entanglement negativity provides a simple way to distinguish Abelian and non-Abelian theories. Our method applies to a Chern-Simons gauge theory defined on an arbitrary oriented (2+1)-dimensional spacetime manifold. Our results agree with the edge theory approach in a recent work [35].

  17. Machine learning to differentiate between positive and negative emotions using pupil diameter

    Directory of Open Access Journals (Sweden)

    Areej eBabiker

    2015-12-01

    Full Text Available Pupil diameter (PD has been suggested as a reliable parameter for identifying an individual’s emotional state. In this paper, we introduce a learning machine technique to detect and differentiate between positive and negative emotions. We presented 30 participants with positive and negative sound stimuli and recorded pupillary responses. The results showed a significant increase in pupil dilation during the processing of negative and positive sound stimuli with greater increase for negative stimuli. We also found a more sustained dilation for negative compared to positive stimuli at the end of the trial, which was utilized to differentiate between positive and negative emotions using a machine learning approach which gave an accuracy of 96.5% with sensitivity of 97.93% and specificity of 98%. The obtained results were validated using another dataset designed for a different study and which was recorded while 30 participants processed word pairs with positive and negative emotions.

  18. Machine Learning to Differentiate Between Positive and Negative Emotions Using Pupil Diameter

    Science.gov (United States)

    Babiker, Areej; Faye, Ibrahima; Prehn, Kristin; Malik, Aamir

    2015-01-01

    Pupil diameter (PD) has been suggested as a reliable parameter for identifying an individual’s emotional state. In this paper, we introduce a learning machine technique to detect and differentiate between positive and negative emotions. We presented 30 participants with positive and negative sound stimuli and recorded pupillary responses. The results showed a significant increase in pupil dilation during the processing of negative and positive sound stimuli with greater increase for negative stimuli. We also found a more sustained dilation for negative compared to positive stimuli at the end of the trial, which was utilized to differentiate between positive and negative emotions using a machine learning approach which gave an accuracy of 96.5% with sensitivity of 97.93% and specificity of 98%. The obtained results were validated using another dataset designed for a different study and which was recorded while 30 participants processed word pairs with positive and negative emotions. PMID:26733912

  19. Quantification and Negation in Event Semantics

    Directory of Open Access Journals (Sweden)

    Lucas Champollion

    2010-12-01

    Full Text Available Recently, it has been claimed that event semantics does not go well together with quantification, especially if one rejects syntactic, LF-based approaches to quantifier scope. This paper shows that such fears are unfounded, by presenting a simple, variable-free framework which combines a Neo-Davidsonian event semantics with a type-shifting based account of quantifier scope. The main innovation is that the event variable is bound inside the verbal denotation, rather than at sentence level by existential closure. Quantifiers can then be interpreted in situ. The resulting framework combines the strengths of event semantics and type-shifting accounts of quantifiers and thus does not force the semanticist to posit either a default underlying word order or a syntactic LF-style level. It is therefore well suited for applications to languages where word order is free and quantifier scope is determined by surface order. As an additional benefit, the system leads to a straightforward account of negation, which has also been claimed to be problematic for event-based frameworks.ReferencesBarker, Chris. 2002. ‘Continuations and the nature of quantification’. Natural Language Semantics 10: 211–242.http://dx.doi.org/10.1023/A:1022183511876Barker, Chris & Shan, Chung-chieh. 2008. ‘Donkey anaphora is in-scope binding’. Semantics and Pragmatics 1: 1–46.Beaver, David & Condoravdi, Cleo. 2007. ‘On the logic of verbal modification’. In Maria Aloni, Paul Dekker & Floris Roelofsen (eds. ‘Proceedings of the Sixteenth Amsterdam Colloquium’, 3–9. Amsterdam, Netherlands: University of Amsterdam.Beghelli, Filippo & Stowell, Tim. 1997. ‘Distributivity and negation: The syntax of each and every’. In Anna Szabolcsi (ed. ‘Ways of scope taking’, 71–107. Dordrecht, Netherlands: Kluwer.Brasoveanu, Adrian. 2010. ‘Modified Numerals as Post-Suppositions’. In Maria Aloni, Harald Bastiaanse, Tikitu de Jager & Katrin Schulz (eds. ‘Logic, Language

  20. A revisão rápida de 100% é eficiente na detecção de resultados falsos-negativos dos exames citopatológicos cervicais e varia com a adequabilidade da amostra: uma experiência no Brasil The 100% rapid rescreening is efficient in the detection of false-negative results and varies according to the quality of the sample: a Brazilian experience

    Directory of Open Access Journals (Sweden)

    Edna Joana Cláudio Manrique

    2007-08-01

    Full Text Available OBJETIVO: avaliar a eficiência da revisão rápida de 100% para detecção de resultados falsos-negativos dos exames citopatológicos cervicais e verificar se esses resultados variam com a adequabilidade da amostra e com a idade da mulher. MÉTODOS: para avaliar a eficiência da revisão rápida, os 5.530 esfregaços classificados como negativos pelo escrutínio de rotina, após serem submetidos à revisão rápida de 100%, foram comparados com as revisões dos esfregaços com base em critérios clínicos e aleatória de 10%. Para análise estatística, as variáveis foram estudadas de maneira descritiva e, quando houve comparação, foram aplicados o teste do chi2 e o teste Cochran-Armitage. RESULTADOS: dos 141 esfregaços suspeitos pela revisão rápida, 84 (59,6% foram confirmados pelo diagnóstico final; desses, 36 (25,5% foram classificados como células escamosas atípicas de significado indeterminado, cinco (3,5% como células escamosas atípicas, não podendo excluir lesão de alto grau, 34 (24,1% como lesão intra-epitelial escamosa de baixo grau, seis (4,3% como lesão intra-epitelial de alto grau e três (2,1% como células glandulares atípicas. Dos 84 esfregaços suspeitos e confirmados pelo diagnóstico final, 62 (73,8 foram classificados como satisfatórios e 22 (26,2% satisfatórios, porém com alguma limitação, mas não se observou diferença significativa com a idade da mulher. CONCLUSÕES: os resultados deste estudo mostraram que a revisão rápida é uma alternativa eficiente como método de controle interno da qualidade na detecção de resultados falsos-negativos dos exames citopatológicos cervicais. Observou-se, também, que a revisão rápida apresentou melhor desempenho quando a amostra foi classificada como satisfatória para análise, porém não variou com a idade da mulher.PURPOSE: to evaluate the efficiency of the 100% rapid rescreening in the detection of false-negative results and to verify whether the results

  1. Perceptual Negativity Predicts Greater Reactivity to Negative Events in Daily Life.

    Science.gov (United States)

    Robinson, Michael D; Liu, Tianwei

    2013-11-01

    Reinforcement sensitivity theory includes the idea that people differ in their sensitivity to negative events, but relevant process-based assessments have not been developed. The present studies assessed sensitivity to negative events in terms of the extent to which negative word stimuli were perceived to be larger than neutral word stimuli. There was a general tendency to overestimate the size of negative relative to neutral words, but individuals differed substantially in this form of what is termed perceptual negativity. Of more importance, two studies (total N = 151) found systematic relationships between individual differences in perceptual negativity and reactivity to negative events in daily diary protocols. Study 1 found that within-person variations in the occurrence of daily negative events undermined goal-related optimism to a greater extent at higher, relative to lower, levels of perceptual negativity. Study 2 conceptually replicated this interaction in the context of within-person associations between the occurrence of daily negative events and antisocial behavior. These findings are important in advancing reinforcement sensitivity theory, in operationalizing a particular component of it, and in extending it to reactivity processes in daily life.

  2. Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts.

    Directory of Open Access Journals (Sweden)

    Jari Kätsyri

    Full Text Available Television viewers' attention is increasingly more often divided between television and "second screens", for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking.

  3. Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts.

    Science.gov (United States)

    Kätsyri, Jari; Kinnunen, Teemu; Kusumoto, Kenta; Oittinen, Pirkko; Ravaja, Niklas

    2016-01-01

    Television viewers' attention is increasingly more often divided between television and "second screens", for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking.

  4. Triple-negative breast cancer: correlation between imaging and pathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Eun Sook; Lee, Byung Hee [Korea Cancer Centre Hospital, Department of Radiology, Seoul (Korea); Kim, Hyun-A; Noh, Woo-Chul [Korea Cancer Centre Hospital, Department of Surgery, Seoul (Korea); Kim, Min Suk [Korea Cancer Centre Hospital, Department of Pathology, Seoul (Korea); Lee, Sang-Ah [Kangwon National University, Department of Preventive Medicine, Kangwon-do (Korea)

    2010-05-15

    This study was designed to investigate the mammography and ultrasound findings of triple-negative breast cancer and to compare the results with characteristics of ER-positive/PR-negative/HER2-negative breast cancer and ER-negative/PR-negative/HER2-positive breast cancer. From January 2007 to October 2008, mammography and ultrasound findings of 245 patients with pathologically confirmed triple-negative (n = 87), ER-positive/PR-negative/HER2-negative (n = 93) or ER-negative/PR-negative/HER2-positive breast cancers (n = 65) were retrospectively reviewed. We also reviewed pathological reports for information on the histological type, histological grade and the status of the biological markers. Triple-negative breast cancers showed a high histological grade. On mammography, triple-negative breast cancers usually presented with a mass (43/87, 49%) or with focal asymmetry (19/87, 22%), and were less associated with calcifications. On ultrasound, the cancers were less frequently seen as non-mass lesions (12/87, 14%), more likely to have circumscribed margins (43/75, 57%), were markedly hypoechoic (36/75, 57%) and less likely to show posterior shadowing (4/75, 5%). Among the three types of breast cancers, ER-negative/PR-negative/HER2-positive breast cancers most commonly had associated calcifications (52/65, 79%) on mammography and were depicted as non-mass lesions (21/65, 32%) on ultrasound. Our results suggest that the imaging findings might be useful in diagnosing triple-negative breast cancer. (orig.)

  5. Tamm plasmon-polariton with negative group velocity induced by a negative index meta-material capping layer at metal-Bragg reflector interface.

    Science.gov (United States)

    Liu, Cunding; Kong, Mingdong; Li, Bincheng

    2014-05-05

    Influence of a negative refractive index meta-material (NIM) capping layer on properties of Tamm plasmon-polariton at the interface of metal-Bragg reflector structure is investigated. Conditions for excitation of the plasmon-polariton is determined from reflectivity mapping calculation and analyzed with cavity mode theory. For specific thicknesses of capping layers, Tamm plasmon-polariton with negative group velocity is revealed in a wide region of frequency. Different from backward optical propagation induced by negative effective-group-refractive-index in dispersive media, negative group velocity of Tamm plasmon-polariton results from opposite signs of cross-section-integrated field energy and Poynting vector.

  6. Positive rights, negative rights and health care.

    Science.gov (United States)

    Bradley, Andrew

    2010-12-01

    In the current debate about healthcare reform in the USA, advocates for government-ensured universal coverage assume that health care is a right. Although this position is politically popular, it is sometimes challenged by a restricted view of rights popular with libertarians and individualists. The restricted view of rights only accepts 'negative' rights as legitimate rights. Negative rights, the argument goes, place no obligations on you to provide goods to other people and thus respect your right to keep the fruits of your labour. A classic enumeration of negative rights includes life, liberty, and the pursuit of happiness. Positive rights, by contrast, obligate you either to provide goods to others, or pay taxes that are used for redistributive purposes. Health care falls into the category of positive rights since its provision by the government requires taxation and therefore redistribution. Therefore, the libertarian or individualist might argue that health care cannot be a true right. This paper rejects the distinction between positive and negative rights. In fact, the protection of both positive and negative rights can place obligations on others. Furthermore, because of its role in helping protect equality of opportunity, health care can be tied to the rights to life, liberty, and the pursuit of happiness. There is, therefore, good reason to believe that health care is a human right and that universal access should be guaranteed. The practical application, by governments and non-governmental organisations, of several of the arguments presented in this paper is also discussed.

  7. Negative capacitance for ultra-low power computing

    Science.gov (United States)

    Khan, Asif Islam

    Owing to the fundamental physics of the Boltzmann distribution, the ever-increasing power dissipation in nanoscale transistors threatens an end to the almost-four-decade-old cadence of continued performance improvement in complementary metal-oxide-semiconductor (CMOS) technology. It is now agreed that the introduction of new physics into the operation of field-effect transistors---in other words, "reinventing the transistor'"--- is required to avert such a bottleneck. In this dissertation, we present the experimental demonstration of a novel physical phenomenon, called the negative capacitance effect in ferroelectric oxides, which could dramatically reduce power dissipation in nanoscale transistors. It was theoretically proposed in 2008 that by introducing a ferroelectric negative capacitance material into the gate oxide of a metal-oxide-semiconductor field-effect transistor (MOSFET), the subthreshold slope could be reduced below the fundamental Boltzmann limit of 60 mV/dec, which, in turn, could arbitrarily lower the power supply voltage and the power dissipation. The research presented in this dissertation establishes the theoretical concept of ferroelectric negative capacitance as an experimentally verified fact. The main results presented in this dissertation are threefold. To start, we present the first direct measurement of negative capacitance in isolated, single crystalline, epitaxially grown thin film capacitors of ferroelectric Pb(Zr0.2Ti0.8)O3. By constructing a simple resistor-ferroelectric capacitor series circuit, we show that, during ferroelectric switching, the ferroelectric voltage decreases, while the stored charge in it increases, which directly shows a negative slope in the charge-voltage characteristics of a ferroelectric capacitor. Such a situation is completely opposite to what would be observed in a regular resistor-positive capacitor series circuit. This measurement could serve as a canonical test for negative capacitance in any novel

  8. Negative evidence in L2 acquisition

    Directory of Open Access Journals (Sweden)

    Anne Dahl

    2005-02-01

    Full Text Available This article deals with the L2 acquisition of differences between Norwegian and English passives, and presents data to show that the acquisition of these differences by Norwegian L2 acquirers of English cannot be fully explained by positive evidence, cues, conservativism or economy. Rather, it is argued, it is natural to consider whether indirect negative evidence may facilitate acquisition by inferencing. The structures in focus are impersonal passive constructions with postverbal NPs and passive constructions with intransitive verbs. These sentences are ungrammatical in English. Chomsky (1981 proposes that this is a result of passive morphology absorbing objective case in English. There is no such case to be assigned to the postverbal NP in impersonal passives. In passive constructions with intransitive verbs, the verb does not assign objective case, so that there is no case for the passive morphology to absorb. Thus, impersonal passives have to be changed into personal passives, where the NP receives nominative case, and the objective case is free to go to the passive morphology. Intransitive verbs, however, cannot be used in the passive voice at all. Both the structures discussed in this article, i.e. are grammatical in Norwegian. However, the options available in English, viz. personal passives and active sentences, are equally possible. Åfarli (1992 therefore proposes that Norwegian has optional case absorption (passive morphology optionally absorbs case. On the basis on such observations, we may propose a parameter with the settings [+case absorption] for English, and [-case absorption], signifying optional case absorption, for Norwegian. This means that none of the structures that are grammatical in English can function as positive evidence for the [+case absorption] setting, since they are also grammatical in optional case absorption languages. The question is how this parameter is set.

  9. Seeing ghosts: negative body evaluation predicts overestimation of negative social feedback.

    Science.gov (United States)

    Alleva, Jessica M; Lange, Wolf-Gero; Jansen, Anita; Martijn, Carolien

    2014-06-01

    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, and of a neutral object, were followed by nonverbal social feedback (i.e., facial crowds with equal numbers of negative, positive, and neutral faces). Afterward, women estimated the percentage of negative, positive, and neutral social feedback that followed their own body, the control woman's body, and the neutral object. The findings provided evidence for a covariation bias: negative body evaluation predicted higher estimates of negative social feedback for women's own body, but not for the other stimuli. Additionally, the covariation bias was not explained by differences in how women interpreted the social feedback (the facial stimuli). Clinical implications of the covariation bias to body image are discussed.

  10. A Translational Investigation of Positive and Negative Behavioral Contrast

    OpenAIRE

    Boyle, Megan A.

    2015-01-01

    Behavioral contrast occurs when a change in reinforcement rate in one context causes behavior to change in the opposite direction in another context. Positive contrast occurs when a decrease in the rate of reinforcement in one context results in an increase in behavior in another context. Negative contrast occurs when an increase in the rate of reinforcement in one context results in a decrease in behavior in another context. Research with nonhumans has found that positive contrast is more re...

  11. On Complete Moment Convergence of Weighted Sums for Arrays of Rowwise Negatively Associated Random Variables

    Directory of Open Access Journals (Sweden)

    Mingle Guo

    2012-01-01

    Full Text Available The complete moment convergence of weighted sums for arrays of rowwise negatively associated random variables is investigated. Some sufficient conditions for complete moment convergence of weighted sums for arrays of rowwise negatively associated random variables are established. Moreover, the results of Baek et al. (2008, are complemented. As an application, the complete moment convergence of moving average processes based on a negatively associated random sequences is obtained, which improves the result of Li et al. (2004.

  12. Studies on Negative Refractive Index without Absorption

    CERN Document Server

    Rajapakse, R M; Yelin, S F

    2012-01-01

    Which systems are ideal to obtain negative refraction with no absorption? Electromagnetically induced transparency (EIT) is a method to suppress absorption and make a material transparent to a field of a given frequency. Such a system has been discussed in [1]; however the main limitations for negative refraction introduced are the necessity of resonant electric and magnetic dipole transitions, and the necessity of very dense media. We suggest using frequency translators in a composite system that would provide negative refraction for a range of optical frequencies while attempting to overcome the limitations discussed above. In the process of using frequency translators, we also find composite systems that can be used for refractive index enhancement.

  13. WHEN ONE MIGHT EXPECT NEGATIVE DISCOUNT RATE?

    Directory of Open Access Journals (Sweden)

    Marcin Palenik

    2012-12-01

    Full Text Available Both in economics and psychology, positive discount rate is usually assumed as an axiom. However, there are circumstances which may lead to negative discount rate. This article presents such a phenomenon. Moreover, author presents particular cases of theories and models which imply preference of receiving lower income in later period of time, rather than higher income in earlier period of time (“less later than more earlier”. The described models are as follows: Life Cycle Hypothesis together with Self Control Theory, Construal Level Theory, Model of Patience Formation and Loewenstein’s Anticipation Model. Authors conclude that there is a need of empirical research verifying implications of these models concerning negative discount rate. Authors believe that the problem of negative discount rate deserves more attention, taking into account that in developed countries interest rates are close to zero and it still does not discourage customers from putting money aside.

  14. Preservation Copying Endangered Historic Negative Collections

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad

    2008-01-01

    This article discusses preservation copying of unstable B&W nitrate and acetate still photographic negatives. It focuses on evaluating two different strategies for preserving the copies from a point of view of quality and cost-effectiveness. The evaluated strategies are preservation of the master...... by describing essential characteristics of negatives, which must be passed on to the copies, and the required metadata and technical imaging specifications. Next the paper discusses strategies for preservation and makes an analysis with the LIFE2 Costing Model. The paper concludes that the most beneficial...... and cost-effective preservation solution for large format negatives is to keep the preservation copies as digital files. However, it also acknowledges that it is important to revisit such strategies regularly to monitor changes in user expectations, technologies and costs....

  15. 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...

  16. Goffman, Parsons, and the Negational Self

    Directory of Open Access Journals (Sweden)

    James J. Chriss

    2015-01-01

    Full Text Available Erving Goffman’s emphasis on impression management in everyday life means that for the most part persons offer only partial or incomplete glimpses of themselves. Indeed, under specifiable conditions self-presentations may take the form of a negational self. If negational selves exist at the person or individual level, then they must also exist at the collective level (that is, if we are to take seriously such notions as the social mind, collective representations, or even culture. Understandings of how this negational self appears and is produced at various analytical levels (micro, meso, and macro can be anchored via a conceptual schema which merges Goffman’s own identity typology with the three-world model of Jürgen Habermas by way of Talcott Parsons.

  17. Negative Energy Cosmology and the Cosmological Constant

    CERN Document Server

    Prokopec, Tomislav

    2011-01-01

    It is well known that string theories naturally compactify on anti-de Sitter spaces, and yet cosmological observations show no evidence of a negative cosmological constant in the early Universe's evolution. In this letter we present two simple nonlocal modifications of the standard Friedmann cosmology that can lead to observationally viable cosmologies with an initial (negative) cosmological constant. The nonlocal operators we include are toy models for the quantum cosmological backreaction. In Model I an initial quasiperiodic oscillatory epoch is followed by inflation and a late time matter era, representing a dark matter candidate. The backreaction in Model II quickly compensates the negative cosmological term such that the Ricci curvature scalar rapidly approaches zero, and the Universe ends up in a late time radiation era.

  18. Quantum Electrodynamics in Media with Negative Refraction

    CERN Document Server

    K"astel, J; Fleischhauer, Michael

    2004-01-01

    We consider the interaction of atoms with the quantized electromagnetic field in the presence of materials with negative index of refraction. Spontaneous emission of an atom embedded in a negative index material is discussed. It is shown furthermore that the possibility of a vanishing optical path length between two spatially separated points provided by these materials can lead to complete suppression of spontaneous emission of an atom in front of a perfect mirror even if the distance between atom and mirror is large compared to the transition wavelength. Two atoms put in the focal points of a lens formed by a parallel slab of ideal negative index material are shown to exhibit perfect sub- and superradiance. The maximum length scale in both cases is limited only by the propagation distance within the free-space radiative decay time. Limitations of the predicted effects arising from absorption, finite transversal extension and dispersion of the material are analyzed.

  19. Negative coupled inductors for polyphase choppers

    Science.gov (United States)

    Jamieson, Robert S. (Inventor)

    1984-01-01

    A technique for negatively coupling the outputs of polyphase choppers is disclosed, wherein the output inductance of each phase is divided into two windings, and each winding is negatively coupled to a corresponding winding of a neighboring phase. In a preferred embodiment for a three-phase chopper circuit, the output inductance of phase A is divided into windings 100 and 102, the output inductance of phase B is divided into windings 110 and 112, and the output inductance of phase C is divided into windings 120 and 122. Pairs of windings 100 and 110, 112 and 120, and 102 and 122 are respectively disposed in transformers arranged for negatively coupling the windings of each pair.

  20. Human immunodeficiency virus-negative plasmablastic lymphoma

    Science.gov (United States)

    Lin, Li; Zhang, Xudong; Dong, Meng; Li, Ling; Wang, Xinhua; Zhang, Lei; Fu, Xiaorui; Sun, Zhenchang; Wu, Jingjing; Li, Zhaoming; Chang, Yu; Wang, Yingjun; Zhou, Zhiyuan; Zhang, Mingzhi; Chen, Qingjiang

    2017-01-01

    Abstract Rationale: Plasmablastic lymphoma (PBL) is a rare subtype of human immunodeficiency virus (HIV)-related non-Hodgkin's lymphoma that predominantly manifests in the oral cavity. Patient concerns: Three cases of HIV-negative PBL were reported. Diagnoses: HIV-negative PBL Interventions: The patient had undergone chemotherapy. Outcomes: Clinical outcomes were very poor in Cases 1 and 3; Case 2, whose diagnosis suggested no bone marrow involvement, is still alive. Lessons subsections: These cases served to broaden the reported clinical spectrum of HIV-negative PBL. Clinicians and pathologists need to be familiar with lymphoma in the identified extra-oral PBL variation and there levant differential diagnosis procedures for this particular disease. PMID:28207555

  1. Negative exploration for pyloric stenosis – Is it preventable?

    Directory of Open Access Journals (Sweden)

    Kenny Simon E

    2008-09-01

    Full Text Available Abstract Background The diagnosis of infantile hypertrophic pyloric stenosis (IHPS, although traditionally clinical, is now increasingly dependent on radiological corroboration. The rate of negative exploration in IHPS has been reported as 4%. The purpose of our study was to look at elements of supportive clinical evidence leading to positive diagnosis, and to review these with respect to misdiagnosed cases undergoing negative exploration. Methods All infants undergoing surgical exploration for IHPS between January 2000 and December 2004 were retrospectively analysed with regard to clinical symptoms, examination findings, investigations and operative findings. Results During the study period, 343 explorations were performed with a presumptive diagnosis of IHPS. Of these, 205 infants (60% had a positive test feed, 269 (78% had a positive ultrasound scan and 175 (55% were alkalotic (pH ≥7.45 and/or base excess ≥2.5. The positive predictive value for an ultrasound (US diagnosis was 99.1% for canal length ≥14 mm, and 98.7% for muscle thickness ≥4 mm. Four infants (1.1% underwent a negative surgical exploration; Ultrasound was positive in 3, and negative in 1(who underwent surgery on the basis of a positive upper GI contrast. One US reported as positive had a muscle thickness Conclusion A 1% rate of negative exploration in IHPS compares favourably with other studies. However potential causes of error were identified in all 4 cases. Confident diagnosis comprises a combination of positive test feed and an 'in house US' in an alkalotic infant. UGI contrast study should not be used in isolation to diagnose IHPS. If the test feed is negative, strict diagnostic measurements should be observed on US and the pyloric 'tumour' palpated on table under anaesthetic before exploration.

  2. [Pediatric osteo-articular infections with negative culture results: what about Kingella kingae?].

    Science.gov (United States)

    Cherkaoui, A; Ceroni, D; Ferey, S; Emonet, S; Schrenzel, J

    2009-11-04

    Kingella kingae is an emerging pathogen that is recognized as a causative agent of septic arthritis and osteomyelitis, primarily in infants and children. The bacterium is best detected by rapid inoculation in blood culture systems or by real-time PCR assays. Pathogenesis of the agent was linked recently to the production of a potent cytotoxin, known as RTX, which is toxic to a variety of human cell types. The locus encoding the RTX toxin is thought to be a putative virulence factor, and is, apparently, essential for inducing cytotoxic effects on respiratory epithelial, synovial and macrophage-like cells. Herein, we describe a novel real-time PCR assay that targets the RTX toxin gene. The assay exhibited a sensitivity of 30 c.f.u., which is 10-fold more sensitive than a previously published semi-nested broad-range 16S rRNA gene PCR, and showed no crossreactivity with several related species and common osteoarticular pathogens. Its clinical impact is illustrated by three pediatric cases.

  3. Leadership Orientation as a Function of Interpersonal Need Structure: A Replication with Negative Results.

    Science.gov (United States)

    Tucker, Jeffrey H.

    1983-01-01

    To replicate the Kuehl et al. (1975) study, 151 graduate students completed the Leadership Opinion Questionnaire, Least Preferred Co-Worker (LPC) Questionnaire, FIRO-B (Functional Interpersonal Relations Orientation-Behavior), and F-Scale. Data failed to replicate earlier significant correlations between interpersonal needs as measured by the LPC…

  4. MMR-Vaccine and Regression in Autism Spectrum Disorders: Negative Results Presented from Japan

    Science.gov (United States)

    Uchiyama, Tokio; Kurosawa, Michiko; Inaba, Yutaka

    2007-01-01

    It has been suggested that the measles, mumps, and rubella vaccine (MMR) is a cause of regressive autism. As MMR was used in Japan only between 1989 and 1993, this time period affords a natural experiment to examine this hypothesis. Data on 904 patients with autism spectrum disorders (ASD) were analyzed. During the period of MMR usage no…

  5. Neural responses to negative feedback are related to negative emotionality in healthy adults

    OpenAIRE

    Santesso, Diane L.; Bogdan, Ryan; Birk, Jeffrey L.; Goetz, Elena L.; Holmes, Avram J.; Pizzagalli, Diego A.

    2011-01-01

    Prior neuroimaging and electrophysiological evidence suggests that potentiated responses in the anterior cingulate cortex (ACC), particularly the rostral ACC, may contribute to abnormal responses to negative feedback in individuals with elevated negative affect and depressive symptoms. The feedback-related negativity (FRN) represents an electrophysiological index of ACC-related activation in response to performance feedback. The purpose of the present study was to examine the FRN and underlyi...

  6. Negative Pressure Consolidation of Silt Inside Bucket Foundation

    Institute of Scientific and Technical Information of China (English)

    Ding Hongyan丁红岩; Liu Yonggang刘永刚; Zhang Puyang张浦阳

    2015-01-01

    A series of model experiments of bucket foundations concerning suction installation and negative pres-sure consolidation in saturated silt were carried out in a cube steel bin at Tianjin University. The experimental re-sults show that the silt inside the bucket has been strengthened by negative pressure, and the strengthening effect decreases with the increase of the distance from the bucket. A three-dimensional numerical model of the experi-ments was built by means of finite element software ABAQUS with fluid-solid coupling method. The results show that the bearing capacity of the silt inside the bucket foundation increases significantly at the former stage of nega-tive pressure consolidation, while the increasing trend slows down over time. The rotation centers of the bucket foundation and the inner soil region tend to be closer to each other based on the consolidation. The bearing capacity of the bucket foundation is improved effectively with the increase of soil strength. The effects of negative pressure consolidation on the bearing capacity of bucket foundation were also illustrated by an actual offshore wind power project case.

  7. Atlas of Tilted Accretion Disks & Source to Negative Superhumps

    CERN Document Server

    Montgomery, M M

    2009-01-01

    Using smoothed particle hydrodynamics, we numerically simulate steady state accretion discs for Cataclysmic Variable Dwarf Novae systems that have a secondary-to-primary mass ratio (0.35 \\le q \\le 0.55). After these accretion discs have come to quasi-equilibrium, we rotate each disc out of the orbital plane by (\\delta = (1, 2, 3, 4, 5,) or (20)^{o}) to induce negative superhumps. For accretion discs tilted $5^{o}$, we generate light curves and associated Fourier transforms for an atlas on negative superhumps and retrograde precession. Our simulation results suggest that accretion discs need to be tilted more than three degrees for negative superhumps to be statistically significant. We also show that if the disc is tilted enough such that the gas stream strikes a disc face, then a dense cooling ring is generated near the radius of impact. In addition to the atlas, we study these artificially tilted accretion discs to find the source to negative superhumps. Our results suggest that the source is additional lig...

  8. Negative ratings play a positive role in information filtering

    Science.gov (United States)

    Zeng, Wei; Zhu, Yu-Xiao; Lü, Linyuan; Zhou, Tao

    2011-11-01

    The explosive growth of information asks for advanced information filtering techniques to solve the so-called information overload problem. A promising way is the recommender system which analyzes the historical records of users’ activities and accordingly provides personalized recommendations. Most recommender systems can be represented by user-object bipartite networks where users can evaluate and vote for objects, and ratings such as “dislike” and “I hate it” are treated straightforwardly as negative factors or are completely ignored in traditional approaches. Applying a local diffusion algorithm on three benchmark data sets, MovieLens, Netflix and Amazon, our study arrives at a very surprising result, namely the negative ratings may play a positive role especially for very sparse data sets. In-depth analysis at the microscopic level indicates that the negative ratings from less active users to less popular objects could probably have positive impacts on the recommendations, while the ones connecting active users and popular objects mostly should be treated negatively. We finally outline the significant relevance of our results to the two long-term challenges in information filtering: the sparsity problem and the cold-start problem.

  9. A Negative Permeability Material at Red Light

    DEFF Research Database (Denmark)

    Yuan, Hsiao-Kuan; Chettiar, Uday K.; Cai, Wenshan;

    2007-01-01

    A negative permeability in a periodic array of pairs of thin silver strips is demonstrated experimentally for two distinct samples. The effect of the strip surface roughness on negative permeability is evaluated. The first sample, Sample A, is fabricated of thinner strips with a root mean square...... roughness of 7 nm, while Sample B is made of thicker strips with 3-nm roughness. The real part of permeability, μ ′ , is −1 at a wavelength of 770 nm in Sample A and −1.7 at 725 nm in Sample B. Relative to prototypes simulated with ideal strips, larger strip roughness acts to decrease μ ′ by a factor of 7...

  10. Osmosis at constant volume. Negative pressure

    CERN Document Server

    Zupanovic, Pasko; Brumen, Milan; Fajmut, Ales; Juretic, Davor

    2009-01-01

    A thermodynamic state of solvent and solution separated with an elastic semipermeable membrane, in the box with a fixed volume, is considered. It is shown that the minimum of the free energy is accompanied by the compression of the solution and tension of the solvent caused by the transfer of solvent molecules into compartment with solution. The tensile state of the solvent is described in terms of negative pressure. It is found that the negative pressure as well as compression pressure is of the order of osmotic pressure given by van't Hoff equation. It is proposed that this mechanism could be responsible for the water uptake in tall trees.

  11. Negative Ion Sources: Magnetron and Penning

    CERN Document Server

    Faircloth, D C

    2013-01-01

    The history of the magnetron and Penning electrode geometry is briefly outlined. Plasma generation by electrical discharge-driven electron impact ionization is described and the basic physics of plasma and electrodes relevant to magnetron and Penning discharges are explained. Negative ions and their applications are introduced, along with their production mechanisms. Caesium and surface production of negative ions are detailed. Technical details of how to build magnetron and Penning surface plasma sources are given, along with examples of specific sources from around the world. Failure modes are listed and lifetimes compared.

  12. Numerical simulations of negative-index refraction in a lamellar composite with alternating single negative layers

    Institute of Scientific and Technical Information of China (English)

    Dong Zheng-Gao; Zhu Shi-Ning; Liu Hui

    2006-01-01

    Negative-index refraction is demonstrated in a lamellar composite with epsilon-negative (ENG) and mu-negative (MNG) materials stacked alternatively. Based on the effective medium approximation, simultaneously negative effective permittivity and permeability of such a lamellar composite are obtained theoretically and further proven by full-wave simulations. Consequently, the renowned left-handed metamaterial comprising split ring resonators and wires is interpreted as an analogy of such ENG-MNG layers. In addition, beyond the effective medium approximation, the propagating field squeezed near the ENG/MNG interface is demonstrated to be left-handed surface waves with backward phase velocity.

  13. Feasibility study for pseudoscopic problem in integral imaging using negative refractive index materials.

    Science.gov (United States)

    Zhang, JianLei; Wang, XiaoRui; Chen, YuJiao; Zhang, QiPing; Yu, Shuo; Yuan, Ying; Guo, BingTao

    2014-08-25

    To solve the pseudoscopic problem, we propose a one-step integral imaging system with negative refractive index materials, which can avoid the deterioration in resolution inherent to the optical or digital two-step processes. Specifically, the proposed method is based on the novel feature of negative refractive index materials, bending light to a negative angle relative to the surface normal. The pseudoscopic imaging property of the negative refractive index material slab is theoretically investigated. For formation of orthoscopic reconstructed images, the matching condition of the negative index lens array and the positive index lens array is deduced. Two types of conceptual prototypes of integral imaging system with negative refractive index materials are designed. Experimental results show the validity of the proposed method. To the best of our knowledge, this is the first time to explore the application of negative index materials in eliminating the pseudoscopic effect in integral imaging.

  14. Negative correlation between brain glutathione level and negative symptoms in schizophrenia: a 3T 1H-MRS study.

    Directory of Open Access Journals (Sweden)

    Daisuke Matsuzawa

    Full Text Available BACKGROUND: Glutathione (GSH, a major intracellular antioxidant, plays a role in NMDA receptor-mediated neurotransmission, which is involved in the pathophysiology of schizophrenia. In the present study, we aimed to investigate whether GSH levels are altered in the posterior medial frontal cortex of schizophrenic patients. Furthermore, we examined correlations between GSH levels and clinical variables in patients. METHODS AND FINDINGS: Twenty schizophrenia patients and 16 age- and gender-matched normal controls were enrolled to examine the levels of GSH in the posterior medial frontal cortex by using 3T SIGNA EXCITE (1H-MRS with the spectral editing technique, MEGA-PRESS. Clinical variables of patients were assessed by the Global Assessment of Functioning (GAF, Scale for the Assessment of Negative Symptoms (SANS, Brief Psychiatric Rating Scale (BPRS, Drug-Induced Extra-Pyramidal Symptoms Scale (DIEPSS, and five cognitive performance tests (Word Fluency Test, Stroop Test, Trail Making Test, Wisconsin Card Sorting Test and Digit Span Distractibility Test. Levels of GSH in the posterior medial frontal cortex of schizophrenic patients were not different from those of normal controls. However, we found a significant negative correlation between GSH levels and the severity of negative symptoms (SANS total score and negative symptom subscore on BPRS in patients. There were no correlations between brain GSH levels and scores on any cognitive performance test except Trail Making Test part A. CONCLUSION: These results suggest that GSH levels in the posterior medial frontal cortex may be related to negative symptoms in schizophrenic patients. Therefore, agents that increase GSH levels in the brain could be potential therapeutic drugs for negative symptoms in schizophrenia.

  15. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    Science.gov (United States)

    Teyssedre, G.; Vu, T. T. N.; Laurent, C.

    2015-12-01

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30-60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10-14-10-13 m2 V-1 s-1 for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets.

  16. Mismatch negativity, social cognition, and functional outcomes in patients after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Hui-yan Sun

    2015-01-01

    Full Text Available Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocognition with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, respectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most significant positive correlations were found between mismatch negativity in the fronto-central region and measures of functional outcomes. The most significant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positively associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental findings suggest that mismatch negativity might efficiently reflect functional outcomes in patients after traumatic brain injury.

  17. Mismatch negativity, social cognition, and functional outcomes in patients after traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Hui-yan Sun; Qiang Li; Xi-ping Chen; Lu-yang Tao

    2015-01-01

    Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocogni-tion with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, re-spectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most signiifcant positive correlations were found be-tween mismatch negativity in the fronto-central region and measures of functional outcomes. The most signiifcant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positive-ly associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental ifndings suggest that mismatch negativity might efifciently relfect functional outcomes in patients after traumatic brain injury.

  18. Negative refractive index in artificial metamaterials.

    Science.gov (United States)

    Grigorenko, A N

    2006-08-15

    We discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity and suggest a simple formula for the refractive index of a general optical medium. Using the effective-field theory, we calculate the effective permeability and the refractive index of nanofabricated media composed of pairs of identical gold nanopillars with magnetic response in the visible spectrum.

  19. Metamaterials: Turning a negative into a positive

    Science.gov (United States)

    Ying, Jackie Y.

    2012-03-01

    Metamaterials are synthetic materials tailored with unusual properties that are not found in nature. It has now been predicted that they could be engineered with negative refractive index through the use of periodic structures via bottom-up self-assembly synthesis.

  20. Negative Impacts of High-Stakes Testing

    Science.gov (United States)

    Minarechová, Michaela

    2012-01-01

    High-stakes testing is not a new phenomenon in education. It has become part of the education system in many countries. These tests affect the school systems, teachers, students, politicians and parents, whether that is in a positive or negative sense. High-stakes testing is associated with concepts such as a school's accountability, funding…

  1. Abortion Rights: Anatomy of a Negative Campaign.

    Science.gov (United States)

    Olasky, Marvin N.

    1987-01-01

    Analyzes a highly successful negative public relations campaign carried on by major pro-choice organizations from October 1985 through March 1987. Explores the effectiveness of this campaign (much of it carried on in the media), and questions the ethics of such a campaign. (NKA)

  2. Negative Impacts of High-Stakes Testing

    Science.gov (United States)

    Minarechová, Michaela

    2012-01-01

    High-stakes testing is not a new phenomenon in education. It has become part of the education system in many countries. These tests affect the school systems, teachers, students, politicians and parents, whether that is in a positive or negative sense. High-stakes testing is associated with concepts such as a school's accountability, funding and…

  3. Positive and negative pulsed corona in argon

    NARCIS (Netherlands)

    Veldhuizen, E.M. van; Rutgers, W.R.; Ebert, U.

    2002-01-01

    Photographs are obtained of corona discharges in argon at atmospheric pressure using a high resolution, intensified CCD camera. Positive and negative polarity is applied at the curved electrode in a point-plane gap and a plane-plane gap with a protruding point. Branching is observed in the positive

  4. Review of Negative Hydrogen Ion Sources

    Science.gov (United States)

    1990-09-01

    is v -senritiv-t-t-ih- -tliffe•p- asma -sffi-ei onverter surface which is biased negative -dfikensions and confitiioS in thigregion.0 ]t ihe-extitifoin...National Laboratory, Accelerator Technology Division, MS H85 1, Los Alamos, New Mexico , 87545 ABSTRACT The Large Orbit Gyrotron Los Alamos is investigating

  5. Energy Levels of a Positronium Negative Ion

    Institute of Scientific and Technical Information of China (English)

    段斌; 顾晓艳; 马中骐

    2001-01-01

    The energy levels of a positronium negative ion are calculated directly from the Schrodinger equation. After removing the translational and rotational degrees of freedom, only three internal variables are involved in both functions and equations. The singularity of the solution is eliminated by choosing the right internal variables, and the series in calculation converges very fast.

  6. Negative attitudes toward masturbation in sex therapy.

    Science.gov (United States)

    Mosher, D L

    1979-01-01

    The incidence of masturbation in males and females as reported by Kinsey was cited as basic data to support Gagnon and Simon's theoretical conceptions of differences in the psychosexual development of males and females. The use of masturbation as treatment in sex therapy was reviewed. An inventory to measure negative attitudes toward masturbation was described, and four research studies supporting its construct validity was summarized. The affective-cognitive structure of masturbation-guilt was posited to inhibit masturbatory behavior and to elicit negative affects such as guilt and disgust as a consequence of masturbation. The use of the inventory measuring negative attitudes toward masturbation was illustrated using the P-LI-SS-IT model. Intensive therapy from a gestalt sex therapy perspective was illustrated as integrating the negative masturbatory schema into self-regulating awareness-expression cycles. A caution to sex therapists alerted them to the importance of awareness of emotions, fantasy, and sociosexual meanings in sex therapy rather than using masturbation as a packaged technique.

  7. [Psychopathological aspects of negative symptoms in schizophrenia].

    Science.gov (United States)

    Cermolacce, M; Belzeaux, R; Pringuey, D; Adida, M; Azorin, J-M

    2015-12-01

    During the past ten years, research on schizophrenia has witnessed a clear emphasis on studies based on negative symptoms. This interest can be explained in terms of diagnosis, specific treatment, functional prognosis and outcome issues. However, main current approaches consider negative symptoms from an operationalist view, which implies objective and atheoretical descriptions of clinical criteria, observed from a third person perspective. And the understanding of negative symptoms in schizophrenia, still a crucial issue of mental health, remains only partial. From a different perspective, psychopathology - and notably psychiatric phenomenology -, can provide a conceptual and clinical framework, taking into account subjective experience (first person perspective), based on a global understanding of the clinical situation lived by patients with schizophrenia. In the present review, we give a brief survey on the historical aspects of the description of negative symptoms. Then, we introduce the clinical contributions raised by clinical phenomenology. We principally develop Minkowski's notion of loss of vital contact, and Blankenburg's notion of loss of natural evidence. Then we highlight the current debates which are discussed and explored in contemporary psychopathology. In conclusion, we discuss the possible articulation between objective and subjective approaches, in order to better understand pauci-symptomatic forms of schizophrenia.

  8. Finite Metric Spaces of Strictly negative Type

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    If a finite metric space is of strictly negative type then its transfinite diameter is uniquely realized by an infinite extent (“load vector''). Finite metric spaces that have this property include all trees, and all finite subspaces of Euclidean and Hyperbolic spaces. We prove that if the distance...

  9. Did Hypatia Know about Negative Numbers?

    CERN Document Server

    Abramowicz, Marek

    2012-01-01

    In this Letter we comment on one particular aspect of Hypatia's enigmatic biography by translating into English a short poem that appeared in a recent review of the third revised Polish edition of Maria Dzielska's book about Hypatia. It poses a simple and specifc question: did Hypatia know about the negative numbers?

  10. Negative pressure wound therapy: clinical utility

    Directory of Open Access Journals (Sweden)

    Sandoz H

    2015-04-01

    Full Text Available Heidi Sandoz Accelerate CIC, Mile End Hospital, London, UK Abstract: Negative pressure wound therapy (NPWT, also known as topical negative pressure therapy, has been increasingly used in health care for the management of a wide variety of wounds over the last 2–3 decades. It is an advanced therapy that can be helpful to accelerate wound healing in both acute and chronic wounds by delivering negative pressure (suction to the wound bed. More recent advancements in the application of NPWT have provided clinicians with wider choices of utilization. There are now devices available that can deliver irrigation to the wound bed, be used for closed surgical incisions, or are disposable and highly portable. Systematic reviews considering NPWT have been published previously. These usually focus on one wound group or device and fail to offer practical clinical guidance due to the scrutiny offered to the evidence via a systematic review process. Here, an overview of the history of NPWT, the varieties of device available, their wide clinical application, and the evidence to support its use are explored in a pragmatic way. Keywords: negative pressure, wound, incision, healing, pain 

  11. Double Negative Materials (DNM), Phenomena and Applications

    Science.gov (United States)

    2009-07-01

    9 Feynman , R. P., R. B. Leighton, and M. Sands. Quantum physics . Vol. 1 of The Feynman Lectures on Physics (Addison-Wesley, 1964...involved in justifying basic physical questions of causality, validity of the concept of negative index of refraction interpretation of experimental...Materials ......................................... 2-4 3. Basic Physics Phenomena

  12. Toward laser cooling of negative lanthanum

    Science.gov (United States)

    Jordan, Elena; Cerchiari, Giovanni; Erlewein, Stefan; Kellerbauer, Alban; UNIC Team

    2016-05-01

    Anion laser cooling holds the potential to allow the production of ultracold ensembles of any negatively charged species by sympathetic cooling. It is a promising technique for cooling of antiprotons to a few mK and could clear the way for precision measurements on cold antihydrogen. Laser cooling of negative ions has never been achieved, since most species have no bound-bound electric dipole transitions. Negative lanthanum (La-) is one of the few anions with multiple electric dipole transitions. The bound-bound transition from the 3F2e ground state to the 3D1o excited state in La- has been proposed theoretically as a candidate for laser cooling. The potential laser cooling transition was identified using laser photodetachment spectroscopy and its excitation energy was measured. We have studied the aforementioned transition in a beam of La anions by high-resolution laser photodetachment spectroscopy. Seven of the nine expected hyperfine structure transitions have been resolved and the transition cross sections have been estimated from experimental observations. It was found that presently La- is the most promising candidate among the atomic anions. We plan to demonstrate the first direct laser cooling of negative ions in a linear radio frequency trap. We gratefully acknowledge support from the European Research Council (ERC).

  13. Treating Problem Behaviors Maintained by Negative Reinforcement.

    Science.gov (United States)

    Cipani, Ennio; Spooner, Fred

    1997-01-01

    Identifies four treatment techniques that may be applied when problem behavior is maintained by negative reinforcement: (1) functional communication training; (2) behavioral momentum; (3) differential reinforcement or an alternative escape behavior; and (4) errorless learning. Each of the techniques is defined, and applications and guidelines for…

  14. A Hidden Case of Negative Amortization.

    Science.gov (United States)

    Waits, Bert K.; Demana, Franklin

    1990-01-01

    The rule of 78 is used by banks and loan companies to compute the amounts due when installment loans are paid early. Describes an unexpected case of negative amortization when the rule is applied. Presents an actual problem and discusses the case. (YP)

  15. Entanglement versus negative domains of Wigner functions

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Mack, H.; Wolf, A.;

    2006-01-01

    We show that s waves, that is wave functions that only depend on a hyperradius, are entangled if and only if the corresponding Wigner functions exhibit negative domains. We illustrate this feature using a special class of s waves which allows us to perform the calculations analytically. This class...

  16. Negative Capability? Measuring the Unmeasurable in Education

    Science.gov (United States)

    Unterhalter, Elaine

    2017-01-01

    This introductory article to the special issue of "Comparative Education" on measuring the unmeasurable in education considers measurement as reflecting facts and uncertainties. The notion of negative capability is used metaphorically to depict some limits of what is measurable, and portray aspects of the process of education, associated…

  17. Vi kan bryde den negative kulturelle arv

    DEFF Research Database (Denmark)

    Pecseli, Benedicta

    2014-01-01

    Den ny bekendtgørelse for pædagoguddannelsen fokuserer på brydning af den negative sociale arv, men det som inklusionspædagogikken skal inkludere til, eller den horisont inden for hvilken alle børn skal gives lige livschance/mulighed, er der næsten ingen redegørelse for. Begreber som Kultur og...

  18. The Positive Side of Negative Labelling

    NARCIS (Netherlands)

    Dam, van Y.K.; Jonge, de J.

    2015-01-01

    Ethical labels signal positive ethical quality of a product but fail to create massive demand for such products. Based on regulatory focus theory and prospect theory, it is argued that negative signalling of low ethical quality would have a stronger effect on the adoption of ethical products than th

  19. Attribution of Negative Intention in Williams Syndrome

    Science.gov (United States)

    Godbee, Kali; Porter, Melanie A.

    2013-01-01

    People with Williams syndrome (WS) are said to have sociable and extremely trusting personalities, approaching strangers without hesitation. This study investigated whether people with WS are less likely than controls to attribute negative intent to others when interpreting a series of ambiguous pictures. This may, at least partially, explain…

  20. Targeting EGFR in Triple Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    Naoto T. Ueno, Dongwei Zhang

    2011-01-01

    Full Text Available Our preliminary data show that erlotinib inhibits Triple-negative breast cancer (TNBC in a xenograft model. However, inhibition of metastasis by erlotinib is accompanied by nonspecific effects because erlotinib can inhibit other kinases; thus, more direct targets that regulate TNBC metastasis need to be identified to improve its therapeutic efficacy.

  1. The Contrast Theory of negative input.

    Science.gov (United States)

    Saxton, M

    1997-02-01

    Beliefs about whether or not children receive corrective input for grammatical errors depend crucially on how one defines the concept of correction. Arguably, previous conceptualizations do not provide a viable basis for empirical research (Gold, 1967; Brown & Hanlon, 1970; Hirsh-Pasek, Treiman & Schneiderman, 1984). Within the Contrast Theory of negative input, an alternative definition of negative evidence is offered, based on the idea that the unique discourse structure created in the juxtaposition of child error and adult correct form can reveal to the child the contrast, or conflict, between the two forms, and hence provide a basis for rejecting the erroneous form. A within-subjects experimental design was implemented for 36 children (mean age 5;0), in order to compare the immediate effects of negative evidence with those of positive input, on the acquisition of six novel irregular past tense forms. Children reproduced the correct irregular model more often, and persisted with fewer errors, following negative evidence rather than positive input.

  2. Negative ion beam extraction in ROBIN

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Gourab, E-mail: bansal@ipr.res.in [Institute for Plasma Research (IPR), Bhat, Gandhinagar, Gujarat 382428 (India); Gahlaut, Agrajit; Soni, Jignesh; Pandya, Kaushal; Parmar, Kanu G.; Pandey, Ravi; Vuppugalla, Mahesh; Prajapati, Bhavesh; Patel, Amee; Mistery, Hiren [Institute for Plasma Research (IPR), Bhat, Gandhinagar, Gujarat 382428 (India); Chakraborty, Arun; Bandyopadhyay, Mainak; Singh, Mahendrajit J.; Phukan, Arindam; Yadav, Ratnakar K.; Parmar, Deepak [ITER-India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujarat 380025 (India)

    2013-10-15

    Highlights: ► A RF based negative hydrogen ion beam test bed has been set up at IPR, India. ► Ion source has been successfully commissioned and three campaigns of plasma production have been carried out. ► Extraction system (35 kV) has been installed and commissioning has been initiated. Negative ion beam extraction is immediate milestone. -- Abstract: The RF based single driver −ve ion source experiment test bed ROBIN (Replica Of BATMAN like source in INDIA) has been set up at Institute for Plasma Research (IPR), India in a technical collaboration with IPP, Garching, Germany. A hydrogen plasma of density 5 × 10{sup 12} cm{sup −3} is expected in driver region of ROBIN by launching 100 kW RF power into the driver by 1 MHz RF generator. The cesiated source is expected to deliver a hydrogen negative ion beam of 10 A at 35 kV with a current density of 35 mA/cm{sup 2} as observed in BATMAN. In first phase operation of the ROBIN ion source, a hydrogen plasma has been successfully generated (without extraction system) by coupling 80 kW RF input power through a matching network with high power factor (cos θ > 0.8) and different plasma parameters have been measured using Langmuir probes and emission spectroscopy. The plasma density of 2.5 × 10{sup 11} cm{sup −3} has been measured in the extraction region of ROBIN. For negative hydrogen ion beam extraction in second phase operation, extraction system has been assembled and installed with ion source on the vacuum vessel. The source shall be first operated in volume mode for negative ion beam extraction. The commissioning of the source with high voltage power supply has been initiated.

  3. Seeing ghosts: Negative body evaluation predicts overestimation of negative social feedback

    NARCIS (Netherlands)

    Alleva, J.M.; Lange, W.G.; Jansen, A.T.M.; Martijn, C.

    2014-01-01

    The current study investigated whether negative body evaluation predicts women's overestimation of negative social feedback related to their own body (i.e., covariation bias). Sixty-five female university students completed a computer task where photos of their own body, of a control woman's body, a

  4. Locating Sites of Negations and Denegating "Negative Essentializing": Rereading Virginia Woolf's "A Room of One's Own"

    Science.gov (United States)

    Adhikari, Manahari

    2014-01-01

    This essay examines how Virginia Woolf uses writing as a tool to locate sites of negations, such as women's exclusion from places of power and knowledge, and to expose negative essentializing that permeates patriarchal structure in "A Room of One's Own." Whereas scholarship on the book has explored a wide range of issues including sex,…

  5. Sentential Negative Markers as Pro-Forms of Negative Sentences in Modern Mongolian

    Science.gov (United States)

    Dagvasumberel, Enkhjargal

    2015-01-01

    Negation in modern Mongolian was analyzed by scholars namely: Luvsanvandan Sh (1968, 2000), Wonsoo Yu (1991), Mönkh-Amgalan Yu (1998), Purev-Ochir B. (1998, 2001), Byambasan P. (2006), Kunihiko Hasimoto (2008), BatIreedui J.(2009), Ravdan E. (2009), Mönkh-Amgalan Yu & Kan Shin (2014). Sentential negation in modern Mongolian is not sufficiently…

  6. Negative Instances in Mathematical Concept Acquisition: Transfer Effects Between the Concepts of Commutativity and Associativity

    Science.gov (United States)

    Shumway, Richard J.

    1974-01-01

    The effects of negative instances on the acquisition of the mathematical concepts of commutativity and associativity were examined. Also investigated were possible transfer effects that might result from the use of negative instances. For 64 ninth-grade subjects, results favored the treatments containing mixed instances and supported the transfer…

  7. TOKAMAK EQUILIBRIA WITH CENTRAL CURRENT HOLES AND NEGATIVE CURRENT DRIVE

    Energy Technology Data Exchange (ETDEWEB)

    CHU, M.S.; PARKS, P.B.

    2002-06-01

    OAK B202 TOKAMAK EQUILIBRIA WITH CENTRAL CURRENT HOLES AND NEGATIVE CURRENT DRIVE. Several tokamak experiments have reported the development of a central region with vanishing currents (the current hole). Straightforward application of results from the work of Greene, Johnson and Weimer [Phys. Fluids, 3, 67 (1971)] on tokamak equilibrium to these plasmas leads to apparent singularities in several physical quantities including the Shafranov shift and casts doubts on the existence of this type of equilibria. In this paper, the above quoted equilibrium theory is re-examined and extended to include equilibria with a current hole. It is shown that singularities can be circumvented and that equilibria with a central current hole do satisfy the magnetohydrodynamic equilibrium condition with regular behavior for all the physical quantities and do not lead to infinitely large Shafranov shifts. Isolated equilibria with negative current in the central region could exist. But equilibria with negative currents in general do not have neighboring equilibria and thus cannot have experimental realization, i.e. no negative currents can be driven in the central region.

  8. Neural effects of positive and negative incentives during marijuana withdrawal.

    Directory of Open Access Journals (Sweden)

    Francesca M Filbey

    Full Text Available In spite of evidence suggesting two possible mechanisms related to drug-seeking behavior, namely reward-seeking and harm avoidance, much of the addiction literature has focused largely on positive incentivization mechanisms associated with addiction. In this study, we examined the contributing neural mechanisms of avoidance of an aversive state to drug-seeking behavior during marijuana withdrawal. To that end, marijuana users were scanned while performing the monetary incentive delay task in order to assess positive and negative incentive processes. The results showed a group x incentive interaction, such that marijuana users had greater response in areas that underlie reward processes during positive incentives while controls showed greater response in the same areas, but to negative incentives. Furthermore, a negative correlation between withdrawal symptoms and response in the amygdala during negative incentives was found in the marijuana users. These findings suggest that although marijuana users have greater reward sensitivity and less harm avoidance than controls, that attenuated amygdala response, an area that underlies fear and avoidance, was present in marijuana users with greater marijuana withdrawal symptoms. This is concordant with models of drug addiction that involve multiple sources of reinforcement in substance use disorders, and suggests the importance of strategies that focus on respective mechanisms.

  9. Estimating negative binomial parameters from occurrence data with detection times.

    Science.gov (United States)

    Hwang, Wen-Han; Huggins, Richard; Stoklosa, Jakub

    2016-11-01

    The negative binomial distribution is a common model for the analysis of count data in biology and ecology. In many applications, we may not observe the complete frequency count in a quadrat but only that a species occurred in the quadrat. If only occurrence data are available then the two parameters of the negative binomial distribution, the aggregation index and the mean, are not identifiable. This can be overcome by data augmentation or through modeling the dependence between quadrat occupancies. Here, we propose to record the (first) detection time while collecting occurrence data in a quadrat. We show that under what we call proportionate sampling, where the time to survey a region is proportional to the area of the region, that both negative binomial parameters are estimable. When the mean parameter is larger than two, our proposed approach is more efficient than the data augmentation method developed by Solow and Smith (, Am. Nat. 176, 96-98), and in general is cheaper to conduct. We also investigate the effect of misidentification when collecting negative binomially distributed data, and conclude that, in general, the effect can be simply adjusted for provided that the mean and variance of misidentification probabilities are known. The results are demonstrated in a simulation study and illustrated in several real examples.

  10. The Relationship Between Trust-in-God, Positive and Negative Affect, and Hope.

    Science.gov (United States)

    Fadardi, Javad S; Azadi, Zeinab

    2017-06-01

    We aimed to test the relationships between Trust-in-God, positive and negative affect, and feelings of hope. A sample of university students (N = 282, 50 % female) completed the Positive and Negative Affect Schedule, the Adult Dispositional Hope Scale, and a Persian measure of Trust-in-God for Muslims. The results of a series of hierarchical regression analyses indicated that Trust-in-God was positively associated with participants' scores for hope and positive affect but was negatively associated with their scores for negative affect. The results support the relationship between Trust-in-God and indices of mental health.

  11. Positively and negatively large Goos-Hänchen lateral displacements from a single negative layered structure.

    Science.gov (United States)

    Talebzadeh, Robabeh; Namdar, Abdolrahman

    2012-09-20

    We study the electromagnetic beam reflection from layered structures that include the so-called ε-negative and the μ-negative materials, also called single negative materials. We predict that such structures can demonstrate a giant lateral Goos-Hänchen shift of the resonant excitation of surface waves at the interface between the conventional and single negative materials, as well as due to the excitation of leaky modes in the layered structures. Then we replace the conventional layer with a left-handed layer (a material with both ε<0 and μ<0). We show that the Goos-Hänchen shift can be positive and negative depending on the type of this layer (conventional or LH material), which can support TE or TM surface waves.

  12. Negative Reinforcement in Applied Behavior Analysis: An Emerging Technology.

    Science.gov (United States)

    Iwata, Brian A.

    1987-01-01

    The article describes three aspects of negative reinforcement as it relates to applied behavior analysis: behavior acquired or maintained through negative reinforcement, the treatment of negatively reinforced behavior, and negative reinforcement as therapy. Current research suggests the emergence of an applied technology on negative reinforcement.…

  13. Negative effects of internet interventions: a qualitative content analysis of patients' experiences with treatments delivered online.

    Science.gov (United States)

    Rozental, Alexander; Boettcher, Johanna; Andersson, Gerhard; Schmidt, Brad; Carlbring, Per

    2015-01-01

    Internet interventions are defined as the delivery of health care-related treatments via an online or a smartphone interface, and have been shown to be a viable alternative to face-to-face treatments. However, not all patients benefit from such treatments, and it is possible that some may experience negative effects. Investigations of face-to-face treatments indicate that deterioration occurs in 5-10% of all patients. The nature and scope of other negative effects of Internet interventions is, however, largely unknown. Hence, the current study explored patients' reported negative experiences while undergoing treatments delivered via the Internet. Data from four large clinical trials (total N = 558) revealed that 9.3% of patients reported some type of negative effects. Qualitative content analysis was used to explore the patients' responses to open-ended questions regarding their negative experiences. Results yielded two broad categories and four subcategories of negative effects: patient-related negative effects (insight and symptom) and treatment-related negative effects (implementation and format). Results emphasize the importance of always considering negative effects in Internet-based interventions, and point to several ways of preventing such experiences, including regular assessment of negative events, increasing the flexibility of treatment schedules and therapist contact, as well as prolonging the treatment duration.

  14. Locus of single-prime negative priming: the role of perceptual form.

    Science.gov (United States)

    Chao, Hsuan-Fu

    2013-07-01

    Single-prime negative priming refers to the phenomenon in which after a single prime word is briefly presented, repeating it as the probe target results in a delay in responding to the target. The present study investigated the locus of this negative priming effect. Experiment 1 showed that repeating the identity of the prime produced a negative priming effect but merely repeating the response of the prime did not. Experiment 2 showed that the negative priming effect transformed into positive priming when the probe distractor was absent. Experiments 3 and 4 further revealed that single-prime negative priming was observed when the perceptual form was repeated. Taken together, these results suggest that single-prime negative priming involves a perceptual locus.

  15. Parental reactions to children's negative emotions: relationships with emotion regulation in children with an anxiety disorder.

    Science.gov (United States)

    Hurrell, Katherine E; Hudson, Jennifer L; Schniering, Carolyn A

    2015-01-01

    Research has demonstrated that parental reactions to children's emotions play a significant role in the development of children's emotion regulation (ER) and adjustment. This study compared parent reactions to children's negative emotions between families of anxious and non-anxious children (aged 7-12) and examined associations between parent reactions and children's ER. Results indicated that children diagnosed with an anxiety disorder had significantly greater difficulty regulating a range of negative emotions and were regarded as more emotionally negative and labile by their parents. Results also suggested that mothers of anxious children espoused less supportive parental emotional styles when responding to their children's negative emotions. Supportive and non-supportive parenting reactions to children's negative emotions related to children's emotion regulation skills, with father's non-supportive parenting showing a unique relationship to children's negativity/lability.

  16. Negative confounding by essential fatty acids in methylmercury neurotoxicity associations

    DEFF Research Database (Denmark)

    Choi, Anna L; Mogensen, Ulla Brasch; Bjerve, Kristian S

    2014-01-01

    BACKGROUND: Methylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestim......BACKGROUND: Methylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result...... concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7 years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder...

  17. Pass transistor Based Negative Edge Trigged D Flip Flop (PTDFF

    Directory of Open Access Journals (Sweden)

    S. P. Nagamani Bai

    2014-04-01

    Full Text Available In this paper a new technique is proposed based on the comparison between Conventional Transistorized Flipflopand Data transition Look ahead D flip flop here we are checking the working of DLDFF and the conventional D Flip-flop after that we are analyzing the characteristic comparison using power & area constraints after that we are proposing a Negative Edge triggered flip-flop named as Passtransistor based negative edge trigged D Flip Flop(PTDFF with reduced number of transistors which will reduce the overall power area as well as delay. The simulations are done using Microwind& DSCH analysis software tools and the result between all those types are listed below. Our proposed system simulations are done under 50nm technology and the results are tabulated below. In that our proposed system is showing better output than the other flip-flops compared here.

  18. [Behavioral therapy of ticks with negative reinforcement in children].

    Science.gov (United States)

    Nabieva, T N; Mukhin, E I

    2003-01-01

    Thirty-two children suffering from motor and vocal ticks exhibited weakness and distonia of ticks-prone muscles were examined. Based on the results obtained earlier, a complex of physical exercises has been worked out and conducted for 20 days. The patients were divided into 3 groups: 1st (n = 10) group did the exercises daily for training the ticks-prone muscles; the 2nd one (n = 10) exercised only after tick's appearance--negative reinforcement; 3rd group (n = 12) did exercises after tick's appearance as well but on irregular basis--probable negative reinforcement. In the 1st group, the exercising resulted in muscle strengthening and decrease of tick's number. The patients of the 2nd group got rid of ticks for 20 days. The probable tick's reinforcement in children of the 3rd group did not change pathological muscle activity. The central mechanisms of cortical plasticity in behavioral therapy of ticks are discussed.

  19. Inflation with negative potentials and the signature reversal symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Mithani, Audrey T.; Vilenkin, Alex, E-mail: audrey.todhunter@tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)

    2013-04-01

    We discuss recent papers by Hartle, Hawking and Hertog, which proposed that quantum cosmology could predict an inflating universe in models with negative scalar potentials. Here we show that this is a result of an underlying symmetry which is manifest in both classical and quantum theory. Moreover, we show that inflating solutions in such models generally develop tachyonic and ghost instabilities and are therefore unphysical in realistic theories.

  20. Antinuclear antibody-negative systemic lupus erythematosus-how common?

    OpenAIRE

    1982-01-01

    A review of five years' DNA-binding antibody results in a routine service laboratory revealed 38 patients who had high DNA-binding capacity (DNA-bc) but no antinuclear antibodies (ANA). On retrospective case note analysis, 22 patients (58%) were thought to have systemic lupus erythematosus (SLE), although only six (16%) fulfilled the preliminary classification criteria of the American Rheumatism Association (ARA). Our findings indicate that ANA-negative SLE is commoner than generally realised...