Science.gov

Sample records for additional negative effect

  1. Biochar mitigates negative effects of salt additions on two herbaceous plant species.

    PubMed

    Thomas, Sean C; Frye, Susan; Gale, Nigel; Garmon, Matthew; Launchbury, Rebecca; Machado, Natasha; Melamed, Sarah; Murray, Jessica; Petroff, Alexandre; Winsborough, Carolyn

    2013-11-15

    Addition of pyrolyzed biomass ("biochar") to soils has commonly been shown to increase crop yields and alleviate plant stresses associated with drought and exposure to toxic materials. Here we investigate the ability of biochar (at two dosages: 5 and 50 t ha(-1)) to mitigate salt-induced stress, simulating road salt additions in a factorial glasshouse experiment involving the broadleaved herbaceous plants Abutilon theophrasti and Prunella vulgaris. Salt additions of 30 g m(-2) NaCl to unamended soils resulted in high mortality rates for both species. Biochar (Fagus grandifolia sawdust pyrolyzed at 378 °C), when applied at 50 t ha(-1) as a top dressing, completely alleviated salt-induced mortality in A. theophrasti and prolonged survival of P. vulgaris. Surviving A. theophrasti plants that received both 50 t ha(-1) biochar and salt addition treatments showed growth rates and physiological performance similar to plants without salt addition. Biochar treatments alone also substantially increased biomass of P. vulgaris, with a ∼50% increase relative to untreated controls at both biochar dosages. Biochar did not significantly affect photosynthetic carbon gain (Amax), water use efficiency, or chlorophyll fluorescence (Fv/Fm) in either species. Our results indicate that biochar can ameliorate salt stress effects on plants through salt sorption, suggesting novel applications of biochar to mitigate effects of salinization in agricultural, urban, and contaminated soils. PMID:23796889

  2. Hypoxia and Acidification Have Additive and Synergistic Negative Effects on the Growth, Survival, and Metamorphosis of Early Life Stage Bivalves

    PubMed Central

    Gobler, Christopher J.; DePasquale, Elizabeth L.; Griffith, Andrew W.; Baumann, Hannes

    2014-01-01

    Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4–7.6) reduced survivorship (by >50%), low oxygen (30–50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios. PMID:24416169

  3. The negative effect of Zr addition on the high temperature strength in alumina-forming austenitic stainless steels

    SciTech Connect

    Moon, Joonoh; Jang, Min-Ho; Kang, Jun-Yun; Lee, Tae-Ho

    2014-01-15

    The effect of a Zr addition on the precipitation behavior and mechanical properties in Nb-containing alumina-forming austenitic (AFA) stainless steels was investigated using tensile tests, scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM) analysis. The TEM observation showed that a Zr addition led to the formation of a (Nb,Zr)(C,N) complex particle, which coarsened the Nb-rich carbonitride. Tensile tests were performed at an elevated temperature (700 °C), and both the tensile and yield strengths decreased with a Zr addition. This unexpected result of a Zr addition was due to the reduction of the precipitation strengthening by particle coarsening. - Highlights: • The effect of Zr on high temperature strength in AFA steel containing Nb was studied. • Both the tensile and yield strengths of an AFA steel decreased with Zr-addition. • This is due to the reduction of precipitation strengthening by particle coarsening. • Nb(C,N) and (Nb,Zr)(C,N) particles were precipitated in an AFA and Zr-added AFA steel. • The size of (Nb,Zr)(C,N) particle is much bigger than that of Nb(C,N) particle.

  4. Estimation of adjusted rate differences using additive negative binomial regression.

    PubMed

    Donoghoe, Mark W; Marschner, Ian C

    2016-08-15

    Rate differences are an important effect measure in biostatistics and provide an alternative perspective to rate ratios. When the data are event counts observed during an exposure period, adjusted rate differences may be estimated using an identity-link Poisson generalised linear model, also known as additive Poisson regression. A problem with this approach is that the assumption of equality of mean and variance rarely holds in real data, which often show overdispersion. An additive negative binomial model is the natural alternative to account for this; however, standard model-fitting methods are often unable to cope with the constrained parameter space arising from the non-negativity restrictions of the additive model. In this paper, we propose a novel solution to this problem using a variant of the expectation-conditional maximisation-either algorithm. Our method provides a reliable way to fit an additive negative binomial regression model and also permits flexible generalisations using semi-parametric regression functions. We illustrate the method using a placebo-controlled clinical trial of fenofibrate treatment in patients with type II diabetes, where the outcome is the number of laser therapy courses administered to treat diabetic retinopathy. An R package is available that implements the proposed method. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27073156

  5. Beneficial effects of activated carbon additives on the performance of negative lead-acid battery electrode for high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Xiang, Jiayuan; Ding, Ping; Zhang, Hao; Wu, Xianzhang; Chen, Jian; Yang, Yusheng

    2013-11-01

    Experiments are made with negative electrode of 2 V cell and 12 V lead-acid battery doped with typical activated carbon additives. It turns out that the negative electrode containing tens-of-micron-sized carbon particles in NAM exhibits markedly increased HRPSoC cycle life than the one containing carbon particles with much smaller size of several microns or the one containing no activated carbon. The improved performance is mainly attributed to the optimized NAM microstructure and the enhanced electrode reaction kinetics by introducing appropriate activated carbon. The beneficial effects can be briefly summarized from three aspects. First, activated carbon acts as new porous-skeleton builder to increase the porosity and active surface of NAM, and thus facilitates the electrolyte diffusion from surface to inner and provides more sites for crystallization/dissolution of lead sulfate; second, activated carbon plays the role of electrolyte supplier to provide sufficient H2SO4 in the inner of plate when the diffusion of H2SO4 from plate surface cannot keep pace of the electrode reaction; Third, activated carbon acts as capacitive buffer to absorb excess charge current which would otherwise lead to insufficient NAM conversion and hydrogen evolution.

  6. The Distinction between Positive and Negative Reinforcement: Some Additional Considerations

    ERIC Educational Resources Information Center

    Sidman, Murray

    2006-01-01

    In this article, the author discusses the distinction between positive and negative reinforcement and some additional considerations. He states that the concept of negative reinforcement has caused confusion, and he believes that the difficulty stems from conventions of ordinary speech, in which the term "negative" usually denotes the opposite of…

  7. The Negative Repetition Effect

    ERIC Educational Resources Information Center

    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…

  8. The negative repetition effect.

    PubMed

    Mulligan, Neil W; Peterson, Daniel J

    2013-09-01

    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 across pairs, the target words were drawn from a small set of categories. In the repetition condition, the pairs were initially presented in a random order and then presented a 2nd time blocked by the category of the target words. In the single presentation condition, the pairs were presented only in the blocked order. Participants in the former condition recalled fewer target words on a free recall test despite having seen the word pairs twice (the negative repetition effect). This phenomenon is explored in a series of 5 experiments assessing 3 theoretical accounts of the effect. The experiments demonstrate that the negative repetition effect generalizes over multiple encoding conditions (reading and generative encoding), over different memory tests (free and cued recall), and over delay (5 min and 2 days). The results argue against a retrieval account and a levels-of-processing account but are consistent with the item-specific-relational account, the account upon which the effect was initially predicated. PMID:23421508

  9. Effects of drying control chemical additive on properties of Li 4Ti 5O 12 negative powders prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ju, Seo Hee; Kang, Yun Chan

    High-density Li 4Ti 5O 12 powders comprising spherical particles are prepared by spray pyrolysis from a solution containing dimethylacetamide (drying control chemical additive) and citric acid and ethylene glycol (organic additives). The prepared powders have high discharge capacities and good cycle properties. The optimum concentration of dimethylacetamide is 0.5 M. The addition of dimethylacetamide to the polymeric spray solutions containing citric acid and ethylene glycol helps in the effective control of the morphology of the Li 4Ti 5O 12 powders. At a constant current density of 0.17 mA g -1, the initial discharge capacities of the powders obtained from the spray solution with and without the organic additives are 171 and 167 mAh g -1, respectively.

  10. Immediate postoperative radiotherapy in residual nonfunctioning pituitary adenoma: Beneficial effect on local control without additional negative impact on pituitary function and life expectancy

    SciTech Connect

    Bergh, Alfons C.M. van den . E-mail: a.c.m.van.den.bergh@rt.umcg.nl; Berg, Gerrit van den; Schoorl, Michiel A.; Sluiter, Wim J.; Vliet, Anton M. van der; Hoving, Eelco W.; Szabo, Ben G.; Langendijk, Johannes A.; Wolffenbuttel, Bruce H.R.; Dullaart, Robin P.F.

    2007-03-01

    Purpose: To demonstrate the benefit of immediate postoperative radiotherapy in residual nonfunctioning pituitary adenoma (NFA) in perspective to the need for hormonal substitution and life expectancy. Methods and Materials: Retrospective cohort analysis of 122 patients, operated for NFA between 1979 and 1998. Recurrence was defined as regrowth on computed tomography or magnetic resonance imaging. The occurrence of hormonal deficiencies was defined as the starting date of hormonal substitution therapy. Results: Seventy-six patients had residual NFA after surgery and received immediate postoperative radiotherapy (Group 1); three patients developed a recurrence, resulting in a 95% local control rate at 10 years. Twenty-eight patients had residual NFA after surgery, but were followed by a wait-and-see policy (Group 2). Sixteen developed a recurrence, resulting in a local control rate of 49% at 5 years and 22% at 10 years (p < 0.001 compared with Group 1). There were no differences between Group 1 and 2 regarding the need for substitution with thyroid hormone, glucocorticoids, and sex hormones before first surgery, directly after surgery and at end of follow-up. There were no differences in hormone substitution free survival between Group 1 and Group 2 during the study period after first surgery. Life expectancy was similar in Group 1 and 2, and their median life expectancy did not differ from median life expectancy in the general population. Conclusions: Immediate postoperative radiotherapy provides a marked improvement of local control among patients with residual NFA compared with surgery alone, without an additional deleterious effect on pituitary function and life expectancy.

  11. Examining the association between rumination, negative affectivity, and negative affect induced by a paced auditory serial addition task.

    PubMed

    Feldner, Matthew T; Leen-Feldner, Ellen W; Zvolensky, Michael J; Lejuez, C W

    2006-09-01

    The present study examined the relations among a depressive ruminative response style, a general propensity to experience negative affectivity, and negative affect induced by a paced serial auditory addition task (PASAT). Ninety nonclinical individuals completed a computerized version of the PASAT, which elicits a generalized negative affect response [Lejuez, C. W., Kahler, C. W., & Brown, R. A. (2003). A modified computer version of the paced auditory serial addition task (PASAT) as a laboratory-based stressor: Implications for behavioral assessment. Behavior Therapist, 26, 290-292]. As hypothesized, there was a moderate correlation between depressive rumination and a propensity to experience negative affect, as indexed both by a significant association with a negative affect personality factor and the prediction of negative affect elicited during the provocation. Findings also suggested that dispositional negative affectivity moderated the effects of a depressive ruminative response style on the valence but not arousal dimensions of emotional responding to the challenge. These findings are discussed in terms of improving our understanding of rumination and its potential role in emotional vulnerability processes. PMID:16139240

  12. Negative effects of positive reinforcement

    PubMed Central

    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. ImagesFigure 1Figure 2 PMID:22478391

  13. Nanotribological Properties of Positively and Negatively charged nanodiamonds as additives to solutions

    NASA Astrophysics Data System (ADS)

    Liu, Zijian; Corley, Steven; Shenderova, Olga; Brenner, Donald; Krim, Jacqueline

    2013-03-01

    Nano-diamond (ND) particles are known to be beneficial for wear and friction reduction when used as additives in liquids, but the fundamental origins of the improvement in tribological properties has not been established. In order to explore this issue, we have investigated the nanotribological properties of ND coated with self-assembled monolayers (SAM) as additives to solutions, employing gold/chrome coated quartz crystal microbalances (QCM). Measurements were performed with the QCM initially immersed in deionized water. ND particles with positively and negatively charged SAM end groups were then added to the water, while the frequency and amplitude of the QCM were monitored. Negative shifts in both the QCM frequency and amplitude were observed when ND with positively charged SAM end groups were added, while positive shifts in both the QCM frequency and amplitude were observed when ND with negatively charged ND end groups were added. The results are consistent with a lubricating effect for the negatively charged ND, but were only observed for sufficiently small negative ND particle size. Experiments on QCM surfaces with differing textures and roughness are in progress, to determine the separate contributing effects of surface roughness charge-water interactions. Funding provided by NSF DMR.

  14. Porous composite with negative thermal expansion obtained by photopolymer additive manufacturing

    NASA Astrophysics Data System (ADS)

    Takezawa, Akihiro; Kobashi, Makoto; Kitamura, Mitsuru

    2015-07-01

    Additive manufacturing (AM) could be a novel method of fabricating composite and porous materials having various effective performances based on mechanisms of their internal geometries. Materials fabricated by AM could rapidly be used in industrial application since they could easily be embedded in the target part employing the same AM process used for the bulk material. Furthermore, multi-material AM has greater potential than usual single-material AM in producing materials with effective properties. Negative thermal expansion is a representative effective material property realized by designing a composite made of two materials with different coefficients of thermal expansion. In this study, we developed a porous composite having planar negative thermal expansion by employing multi-material photopolymer AM. After measurement of the physical properties of bulk photopolymers, the internal geometry was designed by topology optimization, which is the most effective structural optimization in terms of both minimizing thermal stress and maximizing stiffness. The designed structure was converted to a three-dimensional stereolithography (STL) model, which is a native digital format of AM, and assembled as a test piece. The thermal expansions of the specimens were measured using a laser scanning dilatometer. Negative thermal expansion corresponding to less than -1 × 10-4 K-1 was observed for each test piece of the N = 3 experiment.

  15. Potential negative ecological effects of corridors.

    PubMed

    Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

    2014-10-01

    Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening

  16. Strategies of Pre-Service Primary School Teachers for Solving Addition Problems with Negative Numbers

    ERIC Educational Resources Information Center

    Almeida, Rut; Bruno, Alicia

    2014-01-01

    This paper analyses the strategies used by pre-service primary school teachers for solving simple addition problems involving negative numbers. The findings reveal six different strategies that depend on the difficulty of the problem and, in particular, on the unknown quantity. We note that students use negative numbers in those problems they find…

  17. Direct numerical simulations of exhaust gas recirculation effect on multistage autoignition in the negative temperature combustion regime for stratified HCCI flow conditions by using H2O2 addition

    NASA Astrophysics Data System (ADS)

    El-Asrag, Hossam A.; Ju, Yiguang

    2013-04-01

    Direct numerical simulations (DNSs) of a stratified flow in a homogeneous compression charge ignition (HCCI) engine are performed to investigate the exhaust gas recirculation (EGR) and temperature/mixture stratification effects on the autoignition of synthetic dimethyl ether (DME) in the negative temperature combustion region. Detailed chemistry for a DME/air mixture is employed and solved by a hybrid multi-time scale (HMTS) algorithm to reduce the computational cost. The effect of ? to mimic the EGR effect on autoignition are studied. The results show that adding ? enhances autoignition by rapid OH radical pool formation (34-46% reduction in ignition delay time) and changes the ignition heat release rates at different ignition stages. Sensitivity analysis is performed and the important reactions pathways affecting the autoignition are specified. The DNS results show that the scales introduced by thermal and mixture stratifications have a strong effect after the low temperature chemistry (LTC) ignition especially at the locations of high scalar dissipation rates. Compared to homogenous ignition, stratified ignitions show similar first autoignition delay times, but 18% reduction in the second and third ignition delay times. The results also show that molecular transport plays an important role in stratified low temperature ignition, and that the scalar mixing time scale is strongly affected by local ignition in the stratified flow. Two ignition-kernel propagation modes are observed: a wave-like, low-speed, deflagrative mode and a spontaneous, high-speed, ignition mode. Three criteria are introduced to distinguish these modes by different characteristic time scales and Damkhöler numbers using a progress variable conditioned by an ignition kernel indicator. The low scalar dissipation rate flame front is characterized by high displacement speeds and high mixing Damkhöler number. The proposed criteria are applied successfully at the different ignition stages and

  18. Negative Effects from Psychological Treatments: A Perspective

    ERIC Educational Resources Information Center

    Barlow, David H.

    2010-01-01

    The author offers a 40-year perspective on the observation and study of negative effects from psychotherapy or psychological treatments. This perspective is placed in the context of the enormous progress in refining methodologies for psychotherapy research over that period of time, resulting in the clear demonstration of positive effects from…

  19. Proactive and Retroactive Effects of Negative Suggestion

    ERIC Educational Resources Information Center

    Brown, Alan S.; Brown, Christine M.; Mosbacher, Joy L.; Dryden, W. Erich

    2006-01-01

    The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false…

  20. Ulva additions alter soil biogeochemistry and negatively impact Spartina alterniflora growth

    EPA Science Inventory

    Decaying mats of Ulva can be washed into salt marshes by the tides as large wrack deposits, especially in eutrophic estuaries, where they can negatively impact marsh vegetation. We report on a series of field and laboratory mesocosm experiments where we examined the effects of d...

  1. Proactive and retroactive effects of negative suggestion.

    PubMed

    Brown, Alan S; Brown, Christine M; Mosbacher, Joy L; Dryden, W Erich

    2006-11-01

    The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false discrimination was evaluated via multiple-choice tests. Negative suggestion, defined as poorer performance on interference items than noninterference (control) items, consistently occurred when the wrong information followed the correct information (RI) but not when it preceded the correct information (PI). These effects did not change as a function of retention interval (immediate, 1 week, or 3 weeks) or number of incorrect alternatives (1 or 3). Implications of this outcome for experiencing incorrect information in both academic and nonacademic situations are considered. PMID:17087580

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

    ERIC Educational Resources Information Center

    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…

  3. The disembodiment effect of negation: negating action-related sentences attenuates their interference on congruent upper limb movements.

    PubMed

    Bartoli, Eleonora; Tettamanti, Andrea; Farronato, Paolo; Caporizzo, Armanda; Moro, Andrea; Gatti, Roberto; Perani, Daniela; Tettamanti, Marco

    2013-04-01

    Human languages can express opposite propositions by means of the negative operator "not," which turns affirmative sentences into negative ones. Psycholinguistic research has indicated that negative meanings are formed by transiently reducing the access to mental representations of negated conceptual information. Neuroimaging studies have corroborated these findings, showing reduced activation of concept-specific embodied neural systems by negative versus affirmative sentences. This "disembodiment effect" of sentential negation should have two distinct consequences: first, the embodied systems should be computationally more free to support concurrent tasks when processing negative than affirmative sentences; second, the computational interference should only be reduced when there is a strict semantic congruency between the negated concept and the referent targeted by concurrent tasks. We tested these two predictions in two complementary experiments involving the comprehension of action-related sentences and kinematic measurements of its effects on concurrent, congruent actions. Sentences referred to actions involving either proximal or distal arm musculature. In experiment 1, requiring a proximal arm movement, we found interference reduction for negative proximal sentences. In experiment 2, requiring a distal arm movement, we found interference reduction for negative distal sentences. This dissociation provides the first conclusive evidence in support of a disembodiment theory of negation. We conclude that the computational cost resulting from the insertion of an additional lexical item ("not") in negative sentences is compensated by solely storing a concept in affirmative form in semantic memory, since its negative counterpart can be produced by transiently reducing the access to such stored semantic information. PMID:23307950

  4. The Negative Effects of Volatile Sulphur Compounds.

    PubMed

    Milella, Lisa

    2015-01-01

    Oral malodor has been studied extensively in humans but not necessarily to the same degree in our veterinary patients where malodor constitutes a significant problem. Breath malodor may originate from the mouth, or from an extra oral source, originating from other organ systems such as gastrointestinal, respiratory, or even systemic disease. Oral malodor is a result of microbial metabolism of exogenous and endogenous proteinaceous substrates leading to the production of compounds such as indole, skatole, tyramine, cadaverine, puterescine, mercaptans, and sulphides. Volatile sulphur compounds have been shown to be the main cause of oral malodor. Although most clients perceive oral malodor to be primarily a cosmetic problem, there is an increasing volume of evidence in human dental literature demonstrating that volatile sulphur compounds produced by bacteria, even at low concentrations, are toxic to tissues and play a role in the pathogenesis of periodontitis. This article reviews the current available literature in human dentistry looking at these negative effects. No veterinary studies have been conducted looking at the negative effects of volatile sulphur compounds specifically, but as this article highlights, we should be aware of the potential negative effects of volatile sulphur compounds and consider this an area of future research. PMID:26415386

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

    PubMed

    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. PMID:25264353

  6. Chondroitin sulfate addition to CD44H negatively regulates hyaluronan binding

    SciTech Connect

    Ruffell, Brian; Johnson, Pauline . E-mail: pauline@interchange.ubc.ca

    2005-08-26

    CD44 is a widely expressed cell adhesion molecule that binds hyaluronan, an extracellular matrix glycosaminoglycan, in a tightly regulated manner. This regulated interaction has been implicated in inflammation and tumor metastasis. CD44 exists in the standard form, CD44H, or as higher molecular mass isoforms due to alternative splicing. Here, we identify serine 180 in human CD44H as the site of chondroitin sulfate addition and show that lack of chondroitin sulfate addition at this site enhances hyaluronan binding by CD44. A CD44H-immunoglobulin fusion protein expressed in HEK293 cells, and CD44H expressed in murine L fibroblast cells were modified by chondroitin sulfate, as determined by reduced sulfate incorporation after chondroitinase ABC treatment. Mutation of serine 180 or glycine 181 in CD44H reduced chondroitin sulfate addition and increased hyaluronan binding, indicating that serine 180 is the site for chondroitin sulfate addition in CD44H and that this negatively regulates hyaluronan binding.

  7. Longitudinal Slit Procedure in Addition to Negative Pressure Wound Therapy for a Refractory Wound With Exposed Achilles Tendon

    PubMed Central

    Ohata, Erika; Mishima, Yoshito; Matsuo, Kiyoshi

    2015-01-01

    Objective: This case report reviews features of negative pressure wound therapy, particularly for the exposed Achilles tendon, and describes an additional effective procedure. Methods: An 87-year-old man presented with a soft-tissue defect measuring 3×5 cm with the exposed Achilles tendon as a sequela of deep burn. The condition of his affected leg was ischemic because of arteriosclerosis. We used negative pressure wound therapy and made 2 longitudinal slits penetrating the tendon to induce blood flow from the ventral side to the dorsal surface. Results: By this combination therapy, the surface of the exposed Achilles tendon was completely epithelialized and the tendon was spared without disuse syndrome. Conclusions: The authors conclude that this combination therapy is useful for covering the widely exposed tendon in aged patients. PMID:25848445

  8. An in situ generated carbon as integrated conductive additive for hierarchical negative plate of lead-acid battery

    NASA Astrophysics Data System (ADS)

    Saravanan, M.; Ganesan, M.; Ambalavanan, S.

    2014-04-01

    In this work, we report an in situ generated carbon from sugar as additive in the Negative Active Mass (NAM) which enhances the charge-discharge characteristics of the lead-acid cells. In situ formed sugar derived carbon (SDC) with leady oxide (LO) provides a conductive network and excellent protection against NAM irreversible lead sulfation. The effect of SDC and carbon black (CB) added negative plates are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), galvanostatic charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The results show that subtle changes in the addition of carbon to NAM led to subsequent changes on the performance during partial-state-of-charge (PSoC) operations in lead-acid cells. Furthermore, SDC added cells exhibit remarkable improvement in the rate capability, active material utilization, cycle performance and charge acceptance compared to that of the conventional CB added cells. The impact of SDC with LO at various synthesis conditions on the electrochemical performance of the negative plate is studied systematically.

  9. Integration of Consonant and Pitch Processing as Revealed by the Absence of Additivity in Mismatch Negativity

    PubMed Central

    Gong, Diankun; Chen, Sifan; Kendrick, Keith M.; Yao, Dezhong

    2012-01-01

    Consonants, unlike vowels, are thought to be speech specific and therefore no interactions would be expected between consonants and pitch, a basic element for musical tones. The present study used an electrophysiological approach to investigate whether, contrary to this view, there is integrative processing of consonants and pitch by measuring additivity of changes in the mismatch negativity (MMN) of evoked potentials. The MMN is elicited by discriminable variations occurring in a sequence of repetitive, homogeneous sounds. In the experiment, event-related potentials (ERPs) were recorded while participants heard frequently sung consonant-vowel syllables and rare stimuli deviating in either consonant identity only, pitch only, or in both dimensions. Every type of deviation elicited a reliable MMN. As expected, the two single-deviant MMNs had similar amplitudes, but that of the double-deviant MMN was also not significantly different from them. This absence of additivity in the double-deviant MMN suggests that consonant and pitch variations are processed, at least at a pre-attentive level, in an integrated rather than independent way. Domain-specificity of consonants may depend on higher-level processes in the hierarchy of speech perception. PMID:22693614

  10. Negative effects of Phaeocystis globosa on microalgae

    NASA Astrophysics Data System (ADS)

    Liu, Jiesheng; van Rijssel, Marion; Yang, Weidong; Peng, Xichun; Lü, Songhui; Wang, Yan; Chen, Jufang; Wang, Zhaohui; Qi, Yuzao

    2010-07-01

    The potential allelopathic effects of the microalga, Phaeocystis globosa Scherffel, on three harmful bloom algae, Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Chattonella ovata Hara et Chihara were studied. The growth of C. marina and C. ovata was markedly reduced when the organisms were co-cultured with P. globosa or cultured in cell-free spent medium. Haemolytic extracts from P. globosa cells in the senescence phase had a similar inhibitory effect on the three harmful bloom algae. However, P. globosa had less influence on the brine shrimp, Artemia salina. These results indicate that P. globosa may have an allelopathic effect on microalgae, which would explain the superior competitive abilities of P. globosa. Because the addition of the haemolytic toxins from P. globosa had similar effects on algae as spent media, these compounds may be involved in the allelopathic action of P. globosa.

  11. Nitrogen and phosphorus additions negatively affect tree species diversity in tropical forest regrowth trajectories.

    PubMed

    Siddique, Ilyas; Vieira, Ima Célia Guimarães; Schmidt, Susanne; Lamb, David; Carvalho, Cláudio José Reis; Figueiredo, Ricardo de Oliveira; Blomberg, Simon; Davidson, Eric A

    2010-07-01

    Nutrient enrichment is increasingly affecting many tropical ecosystems, but there is no information on how this affects tree biodiversity. To examine dynamics in vegetation structure and tree species biomass and diversity, we annually remeasured tree species before and for six years after repeated additions of nitrogen (N) and phosphorus (P) in permanent plots of abandoned pasture in Amazonia. Nitrogen and, to a lesser extent, phosphorus addition shifted growth among woody species. Nitrogen stimulated growth of two common pioneer tree species and one common tree species adaptable to both high- and low-light environments, while P stimulated growth only of the dominant pioneer tree Rollinia exsucca (Annonaceae). Overall, N or P addition reduced tree assemblage evenness and delayed tree species accrual over time, likely due to competitive monopolization of other resources by the few tree species responding to nutrient enrichment with enhanced establishment and/or growth rates. Absolute tree growth rates were elevated for two years after nutrient addition. However, nutrient-induced shifts in relative tree species growth and reduced assemblage evenness persisted for more than three years after nutrient addition, favoring two nutrient-responsive pioneers and one early-secondary tree species. Surprisingly, N + P effects on tree biomass and species diversity were consistently weaker than N-only and P-only effects, because grass biomass increased dramatically in response to N + P addition. The resulting intensified competition probably prevented an expected positive N + P synergy in the tree assemblage. Thus, N or P enrichment may favor unknown tree functional response types, reduce the diversity of coexisting species, and delay species accrual during structurally and functionally complex tropical rainforest secondary succession. PMID:20715634

  12. Effect of glutathione addition in sparkling wine.

    PubMed

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Marcon, Ângela Rossi; Carnieli, Gilberto João; Vanderlinde, Regina

    2014-09-15

    This study aims to evaluate the effect of the addition of glutathione (GSH) on secondary aromas and on the phenolic compounds of sparkling wine elaborated by traditional method. It was added 10 and 20 mg L(-1) of GSH to must and to base wine. The determination of aroma compounds was performed by gas chromatography. Phenolic compounds and glutathione content were analyzed by high performance liquid chromatography. Sparkling wines with addition of GSH to must showed lower levels of total phenolic compounds and hydroxycinnamic acids. Furthermore, the sparkling wine with addition of GSH to must showed higher levels of 2-phenylethanol, 3-methyl-1-butanol and diethyl succinate, and lower concentrations of ethyl decanoate, octanoic and decanoic acids. The GSH addition to the must show a greater influence on sparkling wine than to base wine, however GSH addition to base wine seems retain higher SO2 free levels. The concentration of GSH added showed no significant difference. PMID:24767072

  13. Pharmacological and Chemical Effects of Cigarette Additives

    PubMed Central

    Rabinoff, Michael; Caskey, Nicholas; Rissling, Anthony; Park, Candice

    2007-01-01

    We investigated tobacco industry documents and other sources for evidence of possible pharmacological and chemical effects of tobacco additives. Our findings indicated that more than 100 of 599 documented cigarette additives have pharmacological actions that camouflage the odor of environmental tobacco smoke emitted from cigarettes, enhance or maintain nicotine delivery, could increase the addictiveness of cigarettes, and mask symptoms and illnesses associated with smoking behaviors. Whether such uses were specifically intended for these agents is unknown. Our results provide a clear rationale for regulatory control of tobacco additives. PMID:17666709

  14. A negative stimulus movement effect in pigeons.

    PubMed

    Daniel, Thomas A; Katz, Jeffrey S

    2016-09-01

    Rhesus monkeys and humans perform more accurately in matching-to-sample tasks when the sample stimulus moves through space (Washburn et al., 1989; Washburn, 1993). This Stimulus Movement Effect (SME) is believed to be due to movement increasing attention toward the sample stimulus, creating an easier discrimination between the sample and choice stimuli. To date, there is no evidence for this phenomenon in a non-mammalian species. In the current study, we investigate the possibility of an SME in an avian species. Across three experiments, pigeons were tested with moving and stationary sample stimuli in a non-matching- to-sample task. The area and velocity by which the sample stimulus traveled was manipulated but no advantage for moving over stationary sample trials was found within or across sessions. Even when a delay condition was implemented, there was no advantage for moving sample trials. Contrary to the results found in humans and monkeys, pigeons performed better when the sample was stationary, a negative SME, and no evidence was found that stimulus movement increases discrimination performance. PMID:27373975

  15. Negative Effects and Occupational Upgrading in a Collective Bargaining Environment.

    ERIC Educational Resources Information Center

    Elkin, Randyl D.

    Manpower training and upgrading programs have negative secondary effects upon regular employees. A review of the literature and empirical research on these negative effects indicated that no model has yet been devised and tested to measure these negative effects. This paper suggests a preliminary model for the evaluation of the disruptive effects…

  16. Differential effects of arousal in positive and negative autobiographical memories.

    PubMed

    Ford, Jaclyn Hennessey; Addis, Donna Rose; Giovanello, Kelly S

    2012-01-01

    Autobiographical memories are characterised by a range of emotions and emotional reactions. Recent research has demonstrated that differences in emotional valence (positive vs. negative emotion) and arousal (the degree of emotional intensity) differentially influence the retrieved memory narrative. Although the mnemonic effects of valence and arousal have both been heavily studied, it is currently unclear whether the effects of emotional arousal are equivalent for positive and negative autobiographical events. In the current study, multilevel models were used to examine differential effects of emotional valence and arousal on the richness of autobiographical memory retrieval both between and within subjects. Thirty-four young adults were asked to retrieve personal autobiographical memories associated with popular musical cues and to rate the valence, arousal and richness of these events. The multilevel analyses identified independent influences of valence and intensity upon retrieval characteristics at the within- and between-subject levels. In addition, the within-subject interactions between valence and arousal highlighted differential effects of arousal for positive and negative memories. These findings have important implications for future studies of emotion and memory, highlighting the importance of considering both valence and arousal when examining the role emotion plays in the richness of memory representation. PMID:22873402

  17. Differential Effects of Arousal in Positive and Negative Autobiographical Memories

    PubMed Central

    Ford, Jaclyn Hennessey; Addis, Donna Rose; Giovanello, Kelly S.

    2014-01-01

    Autobiographical memories are characterized by a range of emotions and emotional reactions. Recent research has demonstrated that differences in emotional valence (positive v. negative emotion) and arousal (the degree of emotional intensity) differentially influence the retrieved memory narrative. Although the mnemonic effects of valence and arousal have both been heavily studied, it is currently unclear whether the effects of emotional arousal are equivalent for positive and negative autobiographical events. In the current study, multilevel models were used to examine differential effects emotional valence and arousal on the richness of autobiographical memory retrieval both between and within subjects. Thirty-four young adults were asked to retrieve personal autobiographical memories associated with popular musical cues and to rate the valence, arousal, and richness of these events. The multilevel analyses identified independent influences of valence and intensity upon retrieval characteristics at the within and between subject levels. In addition, the within subject interactions between valence and arousal highlighted differential effects of arousal for positive and negative memories. These findings have important implications for future studies of emotion and memory, highlighting the importance of considering both valence and arousal when examining the role emotion plays in the richness of memory representation. PMID:22873402

  18. Suicidal Fantasies and Positive/Negative Effects.

    ERIC Educational Resources Information Center

    Fouts, Gregory; Norrie, Janice

    This study attempted to provide some initial normative data to help professionals and researchers to distinguish between playful and stimulating suicidal fantasies as opposed to serious and compulsive thoughts and behaviours characterized by negative affects. It is argued that the former is a natural consequence of cognitive development, the entry…

  19. Addition agents effects on hydrocarbon fuels burning

    NASA Astrophysics Data System (ADS)

    Larionov, V. M.; Mitrofanov, G. A.; Sakhovskii, A. V.

    2016-01-01

    Literature review on addition agents effects on hydrocarbon fuels burning has been conducted. The impact results in flame pattern and burning velocity change, energy efficiency increase, environmentally harmful NOx and CO emission reduction and damping of self-oscillations in flow. An assumption about water molecules dissociation phenomenon existing in a number of practical applications and being neglected in most explanations for physical- chemical processes taking place in case of injection of water/steam into combustion zone has been noted. The hypothesis about necessity of water dissociation account has been proposed. It can be useful for low temperature combustion process control and NOx emission reduction.

  20. Membrane Permeabilization Induced by Sphingosine: Effect of Negatively Charged Lipids

    PubMed Central

    Jiménez-Rojo, Noemi; Sot, Jesús; Viguera, Ana R.; Collado, M. Isabel; Torrecillas, Alejandro; Gómez-Fernández, J.C.; Goñi, Félix M.; Alonso, Alicia

    2014-01-01

    Sphingosine [(2S, 3R, 4E)-2-amino-4-octadecen-1, 3-diol] is the most common sphingoid long chain base in sphingolipids. It is the precursor of important cell signaling molecules, such as ceramides. In the last decade it has been shown to act itself as a potent metabolic signaling molecule, by activating a number of protein kinases. Moreover, sphingosine has been found to permeabilize phospholipid bilayers, giving rise to vesicle leakage. The present contribution intends to analyze the mechanism by which this bioactive lipid induces vesicle contents release, and the effect of negatively charged bilayers in the release process. Fluorescence lifetime measurements and confocal fluorescence microscopy have been applied to observe the mechanism of sphingosine efflux from large and giant unilamellar vesicles; a graded-release efflux has been detected. Additionally, stopped-flow measurements have shown that the rate of vesicle permeabilization increases with sphingosine concentration. Because at the physiological pH sphingosine has a net positive charge, its interaction with negatively charged phospholipids (e.g., bilayers containing phosphatidic acid together with sphingomyelins, phosphatidylethanolamine, and cholesterol) gives rise to a release of vesicular contents, faster than with electrically neutral bilayers. Furthermore, phosphorous 31-NMR and x-ray data show the capacity of sphingosine to facilitate the formation of nonbilayer (cubic phase) intermediates in negatively charged membranes. The data might explain the pathogenesis of Niemann-Pick type C1 disease. PMID:24940775

  1. Nosewitness identification: effects of negative emotion.

    PubMed

    Alho, Laura; Soares, Sandra C; Ferreira, Jacqueline; Rocha, Marta; Silva, Carlos F; Olsson, Mats J

    2015-01-01

    Every individual has a unique body odor (BO), similar to a fingerprint. In forensic research, identification of culprit BOs has been performed by trained dogs, but not by humans. We introduce the concept of nosewitness identification and present the first experimental results on BO memory in witness situations involving violent crimes. Two experiments indicated that BO associated with male characters in authentic videos could later be identified in BO lineup tests well above chance. Moreover, culprit BO in emotional crime videos could be identified considerably better than the BO of a male person in neutral videos. This indicates that nosewitness identification benefits from emotional encoding. Altogether, the study testifies to the virtue of body odor as a cue to identify individuals observed under negative emotion. PMID:25612211

  2. Renal effects of continuous negative pressure breathing

    NASA Technical Reports Server (NTRS)

    Kinney, M. J.; Discala, V. A.

    1975-01-01

    Continuous negative pressure breathing (CNPB) was utilized to simulate the thoracic vascular distension of zero g or space, in 11 anesthetized rats. The animals underwent renal clearance and micropuncture renal nephron studies before, during, and after CNPB. Rats were pretreated with a high salt diet and I-M desoxycorticosterone (DOCA) in excess. None of these rats diuresed with CNPB. In contrast 5 of the 7 remaining rats increased the fraction of the filtered sodium excreted (C sub Na/GFR, p .05) and their urinary flow rate (V, p .05). Potassium excretion increased (U sub k V, p .05). End proximal tubular fluid specimen's TF/P inulin ratios were unchanged. Whole kidney and single nephron glomerular filtration rates fell 10%. CNPB, a mechanism for atrial distension, appears to cause, in rats, a decrease in distal tubular sodium, water and potassium reabsorption. Exogenous mineral-corticoid prevents the diuresis, saluresis, and kaluresis.

  3. Nosewitness Identification: Effects of Negative Emotion

    PubMed Central

    Ferreira, Jacqueline; Rocha, Marta; Silva, Carlos F.; Olsson, Mats J.

    2015-01-01

    Every individual has a unique body odor (BO), similar to a fingerprint. In forensic research, identification of culprit BOs has been performed by trained dogs, but not by humans. We introduce the concept of nosewitness identification and present the first experimental results on BO memory in witness situations involving violent crimes. Two experiments indicated that BO associated with male characters in authentic videos could later be identified in BO lineup tests well above chance. Moreover, culprit BO in emotional crime videos could be identified considerably better than the BO of a male person in neutral videos. This indicates that nosewitness identification benefits from emotional encoding. Altogether, the study testifies to the virtue of body odor as a cue to identify individuals observed under negative emotion. PMID:25612211

  4. Negative mass

    NASA Astrophysics Data System (ADS)

    Hammond, Richard T.

    2015-03-01

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

  5. Renal effects of continuous negative pressure breathing

    NASA Technical Reports Server (NTRS)

    Kinney, M. J.

    1975-01-01

    Continuous negative pressure breathing (CNPB) was utilized to simulate the thoracic vascular distension of zero G in 11 anesthetized rats. The animals underwent renal clearance and micropuncture renal nephron studies before, during, and after CNPB. Four rats were pretreated with a high salt diet and I-M desoxycorticosterone (DOCA) in excess. None of these rats diuresed with CNPB. In contrast, five of the seven remaining rats increased the fraction of the filtered sodium excreted and their urinary flow rate. Potassium excretion increased. End proximal tubular fluid specimen's TF/P inulin ratios were unchanged. Whole kidney and single nephron glomerular filtration rates fell 10%. CNPB, a mechanism for atrial distension, appears to cause in the rat a decrease in distal tubular sodium and water reabsorption. Exogenous mineral-corticoid prevents the diuresis, saluresis, and kaluresis. The adequacy of other nonatrial volume control mechanisms in regulating renal salt and water conservation in opposition to the studied atrial-renal (Henry-Gauer) reflex of thoracic vascular distension is confirmed.

  6. 40 CFR 57.816 - Effect of negative recommendation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Effect of negative recommendation. 57.816 Section 57.816 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement...

  7. 40 CFR 57.816 - Effect of negative recommendation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Effect of negative recommendation. 57.816 Section 57.816 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Reduction Technology § 57.816 Effect of negative recommendation. No waiver of the interim requirement...

  8. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  9. The Negative Testing Effect and Multifactor Account

    ERIC Educational Resources Information Center

    Peterson, Daniel J.; Mulligan, Neil W.

    2013-01-01

    Across 3 experiments, we investigated the factors that dictate when taking a test improves subsequent memory performance (the "testing effect"). In Experiment 1, participants retrieving a set of targets during a retrieval practice phase ultimately recalled fewer of those targets compared with a group of participants who studied the…

  10. Cognitive Effects of Greek Affiliation in College: Additional Evidence

    ERIC Educational Resources Information Center

    Pascarella, Ernest T.; Flowers, Lamont; Whitt, Elizabeth J.

    2009-01-01

    Previous research published in this journal found broad-based negative effects of Greek affiliation on standardized measures of cognitive development after 1 year of college. Following the same sample, and employing essentially the same research design and analytic model, the present study found that the negative effects of Greek affiliation were…

  11. Effect of nicotine on negative affect among more impulsive smokers.

    PubMed

    Doran, Neal; McChargue, Dennis; Spring, Bonnie; VanderVeen, Joe; Cook, Jessica Werth; Richmond, Malia

    2006-08-01

    In the present study, the authors tested the hypothesis that nicotine would provide greater relief from negative affect for more impulsive smokers than for less impulsive smokers. Euthymic adult smokers (N=70) participated in 2 laboratory sessions, during which they underwent a negative mood induction (music + autobiographical memory), then smoked either a nicotinized or de-nicotinized cigarette. Mixed-effects regression yielded a significant Impulsivity x Condition (nicotinized vs. de-nicotinized) x Time interaction. Simple effects analyses showed that heightened impulsivity predicted greater negative affect relief after smoking a nicotinized cigarette but not after smoking a de-nicotinized cigarette. These data suggest that nicotine may be a disproportionately powerful negative reinforcer for highly impulsive smokers, promoting higher levels of nicotine dependence and inhibiting smoking cessation. PMID:16893271

  12. The negative compatibility effect: A case for self-inhibition

    PubMed Central

    Schlaghecken, Friederike; Rowley, Laura; Sembi, Sukhdev; Simmons, Rachel; Whitcomb, Daniel

    2008-01-01

    In masked priming, a briefly presented prime stimulus is followed by a mask, which in turn is followed by the task-relevant target. Under certain conditions, negative compatibility effects (NCNCEs) occur, with impaired performance on compatible trials (where prime and target indicate the same response) relative to incompatible trials (where they indicate opposite responses). However, the exact boundary conditions of NCEs, and hence the functional significance of this effect, are still under discussion. In particular, it has been argued that the NCE might be a stimulus-specific phenomenon of little general interest. This paper presents new findings indicating that the NCE can be obtained under a wider variety of conditions, suggesting that it reflects more general processes in motor control. In addition, evidence is provided suggesting that prime identification levels in forced choice tasks – usually employed to estimate prime visibility in masked prime tasks – are affected by prior experience with the prime (Exp. 1) as well as by direct motor priming (Exp. 2 & 3). PMID:20517511

  13. Negativity bias and task motivation: testing the effectiveness of positively versus negatively framed incentives.

    PubMed

    Goldsmith, Kelly; Dhar, Ravi

    2013-12-01

    People are frequently challenged by goals that demand effort and persistence. As a consequence, philosophers, psychologists, economists, and others have studied the factors that enhance task motivation. Using a sample of undergraduate students and a sample of working adults, we demonstrate that the manner in which an incentive is framed has implications for individuals' task motivation. In both samples we find that individuals are less motivated when an incentive is framed as a means to accrue a gain (positive framing) as compared with when the same incentive is framed as a means to avoid a loss (negative framing). Further, we provide evidence for the role of the negativity bias in this effect, and highlight specific populations for whom positive framing may be least motivating. Interestingly, we find that people's intuitions about when they will be more motivated show the opposite pattern, with people predicting that positively framed incentives will be more motivating than negatively framed incentives. We identify a lay belief in the positive correlation between enjoyment and task motivation as one possible factor contributing to the disparity between predicted and actual motivation as a result of the framing of the incentive. We conclude with a discussion of the managerial implications for these findings. PMID:24059820

  14. The Immoral Assumption Effect: Moralization Drives Negative Trait Attributions.

    PubMed

    Meindl, Peter; Johnson, Kate M; Graham, Jesse

    2016-04-01

    Jumping to negative conclusions about other people's traits is judged as morally bad by many people. Despite this, across six experiments (total N = 2,151), we find that multiple types of moral evaluations--even evaluations related to open-mindedness, tolerance, and compassion--play a causal role in these potentially pernicious trait assumptions. Our results also indicate that moralization affects negative-but not positive-trait assumptions, and that the effect of morality on negative assumptions cannot be explained merely by people's general (nonmoral) preferences or other factors that distinguish moral and nonmoral traits, such as controllability or desirability. Together, these results suggest that one of the more destructive human tendencies--making negative assumptions about others--can be caused by the better angels of our nature. PMID:26984017

  15. Negative cooperativity in Root-effect hemoglobins: role of heterogeneity.

    PubMed

    Decker, Heinz; Nadja, Hellmann

    2007-10-01

    In some animals, the oxygen transport capacity of blood decreases when pH is lowered, yielding oxygen binding curves with Hill-coefficients smaller than unity. This so-called Root effect is observed in several fishes and is important for creating large oxygen partial pressures locally, for example in the swim bladder. While there is general agreement on the physiological advantages of this effect, its molecular basis remains ambiguous. Various studies show that isoforms of hemoglobins usually are present in the hemolymph, when the Root effect is observed. Here, we show that in such a case the mixture of these isoforms can exhibit apparent negative cooperativity, although each component taken separately can be described by the MWC model. In other cases, isolated isoforms exhibit true negative cooperativity. The well established MWC model describes many cooperative phenomena of enzymes and respiratory proteins but is not capable of describing negative cooperativity. In order to model negative cooperativity within a single molecular species a decoupling model might be employed, as pointed out previously. However, simulations show that it is not mandatory to have species with negative cooperativity, in order to obtain the binding curves typically seen for whole blood. These two aspects of the Root effect will be discussed on the basis of data from the literature. PMID:21672870

  16. Cost effective processes by using negative-tone development application

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kei; Kato, Keita; Ou, Keiyu; Shirakawa, Michihiro; Kamimura, Sou

    2015-03-01

    The high volume manufacturing with extreme ultraviolet (EUV) lithography is delaying due to its light source issue. Therefore, ArF-immersion lithography has still been the most promising technology for down scaling of device pitch. As the limitation of ArF-immersion single patterning is considered to be nearly 40nm half pitch (hp), ArF-immersion lithography has necessity to be extended by combining processes to achieve sub- 20nm hp patterning. Recently, there are many reports about the extension of ArF-immersion lithography, e.g., self-aligned multiple patterning (SAMP) and litho-etch-litho-etch (LELE) process. These methods have been realized by the combination of lithography, deposition, and etching. On the other aspect, 1-D layout is adopted for leading devices, which contains additional cut or block litho and etch processes to form 2-D like layout. Thus, according to the progress of down scaling technologies, number of processes increases and the cost of ownership (CoO) can not be neglected. Especially, the number of lithography steps and etching steps has been expanded by the combination of processes, and it has come to occupy a large portion of total manufacturing cost. We have reported that negative tone development (NTD) system using organic solvent developer have enough resolution to achieve fine narrow trench or contact hole patterning, since negative tone imaging enables to apply bright mask for these pattern with significantly high optical image contrast compared to positive tone imaging, and it has contributed high throughput multiple patterning. On the other hand, NTD system is found to be useful not only for leading device node, but also for cost effective process. In this report, we propose the cost effective process using NTD application. In the viewpoint of cost down at exposure tool, we have developed KrF-NTD resist which is customized for organic solvent developer. Our KrF-NTD resist has resolution comparable with ArF positive tone development

  17. Experimental Observation of Negative Effective Gravity in Water Waves

    PubMed Central

    Hu, Xinhua; Yang, Jiong; Zi, Jian; Chan, C. T.; Ho, Kai-Ming

    2013-01-01

    The gravity of Earth is responsible for the formation of water waves and usually difficult to change. Although negative effective gravity was recently predicted theoretically in water waves, it has not yet been observed in experiments and remains a mathematical curiosity which is difficult to understand. Here we experimentally demonstrate that close to the resonant frequency of purposely-designed resonating units, negative effective gravity can occur for water waves passing through an array of resonators composing of bottom-mounted split tubes, resulting in the prohibition of water wave propagation. It is found that when negative gravity occurs, the averaged displacement of water surface in a unit cell of the array has a phase difference of π to that along the boundary of the unit cell, consistent with theoretical predictions. Our results provide a mechanism to block water waves and may find applications in wave energy conversion and coastal protection. PMID:23715132

  18. Method effects: the problem with negatively versus positively keyed items.

    PubMed

    Lindwall, Magnus; Barkoukis, Vassilis; Grano, Caterina; Lucidi, Fabio; Raudsepp, Lennart; Liukkonen, Jarmo; Thøgersen-Ntoumani, Cecilie

    2012-01-01

    Using confirmatory factor analyses, we examined method effects on Rosenberg's Self-Esteem Scale (RSES; Rosenberg, 1965) in a sample of older European adults. Nine hundred forty nine community-dwelling adults 60 years of age or older from 5 European countries completed the RSES as well as measures of depression and life satisfaction. The 2 models that had an acceptable fit with the data included method effects. The method effects were associated with both positively and negatively worded items. Method effects models were invariant across gender and age, but not across countries. Both depression and life satisfaction predicted method effects. Individuals with higher depression scores and lower life satisfaction scores were more likely to endorse negatively phrased items. PMID:22339312

  19. Negative Effects of Learning Spreadsheet Management on Learning Database Management

    ERIC Educational Resources Information Center

    Vágner, Anikó; Zsakó, László

    2015-01-01

    A lot of students learn spreadsheet management before database management. Their similarities can cause a lot of negative effects when learning database management. In this article, we consider these similarities and explain what can cause problems. First, we analyse the basic concepts such as table, database, row, cell, reference, etc. Then, we…

  20. A Negative Effect of Repetition in Episodic Memory

    ERIC Educational Resources Information Center

    Peterson, Daniel J.; Mulligan, Neil W.

    2012-01-01

    One of the foundational principles of human memory is that repetition (i.e., being presented with a stimulus multiple times) improves recall. In the current study a group of participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once, a negative repetition effect. Such a…

  1. Spin-memory effect and negative magnetoresistance in hopping conductivity

    NASA Astrophysics Data System (ADS)

    Agam, Oded; Aleiner, Igor L.; Spivak, Boris

    2014-03-01

    We propose a mechanism for negative isotropic magnetoresistance in the hopping regime. It results from a memory effect encrypted into spin correlations that are not taken into account by the conventional theory of hopping conductivity. The spin correlations are generated by the nonequilibrium electric currents and lead to the decrease of the conductivity. The application of the magnetic field destroys the correlations thus enhancing the conductance. This effect can occur even at magnetic fields as small as a few gauss.

  2. Negative refraction, gain and nonlinear effects in hyperbolic metamaterials.

    PubMed

    Argyropoulos, Christos; Estakhri, Nasim Mohammadi; Monticone, Francesco; Alù, Andrea

    2013-06-17

    The negative refraction and evanescent-wave canalization effects supported by a layered metamaterial structure obtained by alternating dielectric and plasmonic layers is theoretically analyzed. By using a transmission-line analysis, we formulate a way to rapidly analyze the negative refraction operation for given available materials over a broad range of frequencies and design parameters, and we apply it to broaden the bandwidth of negative refraction. Our analytical model is also applied to explore the possibility of employing active layers for loss compensation. Nonlinear dielectrics can also be considered within this approach, and they are explored in order to add tunability to the optical response, realizing positive-to-zero-to-negative refraction at the same frequency, as a function of the input intensity. Our findings may lead to a better physical understanding and improvement of the performance of negative refraction and subwavelength imaging in layered metamaterials, paving the way towards the design of gain-assisted hyperlenses and tunable nonlinear imaging devices. PMID:23787691

  3. Determinants of positive and negative generation effects in free recall.

    PubMed

    Steffens, M C; Erdfelder, E

    1998-11-01

    Better retention of self-produced as opposed to experimenter-presented material is called generation effect; the reverse phenomenon is the negative generation effect. Both are found in intentional-learning experiments in which generating versus reading is manipulated between subjects. The present article presents an overview of those findings and aims at clarifying the conditions under which these effects emerge. Experiments 1 and 2 demonstrate that if cue-target relations are manipulated within one list, a negative generation effect in free recall can be obtained for all items, no matter which cue-target relation they bear. In Experiment 3, cue-target relations were manipulated between lists. Here, a negative generation effect in free recall was found only in lists in which items were cued with words that mismatched the inter-target relations, whereas a positive generation effect was observed in those lists in which the generation cues matched the inter-target relations. A subsequent cued-recall test demonstrated that in cases of mismatch of relations, participants in the generate condition process cue-target relations at the expense of inter-target relations. The three-factor theory can be integrated with the task-demand account in a transfer-appropriate processing framework to accommodate these findings. PMID:9854440

  4. Development of additives in negative active-material to suppress sulfation during high-rate partial-state-of-charge operation of lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Sawai, Ken; Funato, Takayuki; Watanabe, Masashi; Wada, Hidetoshi; Nakamura, Kenji; Shiomi, Masaaki; Osumi, Shigeharu

    Additives in the negative active-material of lead-acid batteries were examined to determine whether they could prevent progressive accumulation of lead sulfate (PbSO 4) in negative plates during high-rate partial-state-of-charge (HRPSoC) operation. This phenomenon is caused by progressive growth of PbSO 4 particles and a lack of conductive paths near these PbSO 4 particles. Barium sulfate (BaSO 4) particles in various sizes and synthetic lignin were added to the negative active-material to control PbSO 4 particle size during HRPSoC cycle-life. Some types of carbon fibres were also added to form conductive paths around the PbSO 4 particles. Synthetic lignin was found to be the most effective additive for improving battery life in HRPSoC cycle-life tests, whereas the other factors such as BaSO 4 size or carbon fibre extended less influence. The growth rate of PbSO 4 particles per cycle was much lower in a cell with synthetic lignin than in a cell with natural lignin.

  5. Acute Effects of Marijuana Smoking on Negative and Positive Affect

    PubMed Central

    Metrik, Jane; Kahler, Christopher W.; McGeary, John E.; Monti, Peter M.; Rohsenow, Damaris J.

    2013-01-01

    Human studies and animal experiments present a complex and often contradictory picture of the acute impact of marijuana on emotions. The few human studies specifically examining changes in negative affect find either increases or reductions following delta-9-tetrahydrocannabinol (THC) administration. In a 2 × 2, instructional set (told THC vs. told no THC) by drug administration (smoked marijuana with 2.8% THC vs. placebo) between-subjects design, we examined the pharmacologic effect of marijuana on physiological and subjective stimulation, subjective intoxication, and self-reported negative and positive affect with 114 weekly marijuana smokers. Individuals were first tested under a baseline/no smoking condition and again under experimental condition. Relative to placebo, THC significantly increased arousal and confusion/bewilderment. However, the direction of effect on anxiety varied depending on instructional set: Anxiety increased after THC for those told placebo but decreased among other participants. Furthermore, marijuana users who expected more impairment from marijuana displayed more anxiety after smoking active marijuana, whereas those who did not expect the impairment became less anxious after marijuana. Both pharmacologic and stimulus expectancy main effects significantly increased positive affect. Frequent marijuana users were less anxious after smoking as compared to less frequent smokers. These findings show that expectancy instructions and pharmacology play independent roles in effects of marijuana on negative affect. Further studies examining how other individual difference factors impact marijuana's effects on mood are needed. PMID:24319318

  6. Positive and negative generation effects, hypermnesia, and total recall time.

    PubMed

    Mulligan, Neil W; Duke, Marquinn D

    2002-10-01

    Self-generated information is typically remembered better than perceived information (the generation effect). Experimental design produces an important limiting condition for this effect: Generation enhances recall in within-subjects designs, but typically not in between-subjects designs. However, Mulligan (2001) found that the generation effect emerged over repeated recall tests in a between-subjects design, calling into question the generality of this limiting condition. Two experiments further delineated the emergent generation effect Experiment 1 demonstrated that this effect does not require multiple discrete recall tests but may emerge on a single recall test of long duration. Experiment 2 demonstrated that the negative generation effect (a reversal of the typical generation effect produced under certain conditions) is abolished by multiple recall tests. In both experiments, the generate condition produced greater hypemnesia (increased recall over tests) than did the read condition. PMID:12507369

  7. The Innuendo Effect: Hearing the Positive but Inferring the Negative

    PubMed Central

    Kervyn, Nicolas; Bergsieker, Hilary B.; Fiske, Susan T.

    2015-01-01

    Speakers can convey mixed impressions by providing only positive information. As a series of studies shows, when communicators omit information on a salient, relevant dimension of social perception, listeners make negative inferences about the target on that omitted dimension, despite directly receiving only positive information on another dimension (Studies 1 and 2a). These negative inferences mediated the effect of the innuendo manipulation on judgments about the target person's suitability for inclusion in one's group. Simulating communication, Study 2b participants read Study 2a's descriptions and showed this innuendo effect is stronger for descriptions of female as opposed to male targets in an academic domain. We discuss implications of innuendo for the communication and perpetuation of mixed impressions and their prevalence in descriptions of subordinate group members. PMID:26023243

  8. Blocked Shape Memory Effect in Negative Poisson's Ratio Polymer Metamaterials.

    PubMed

    Boba, Katarzyna; Bianchi, Matteo; McCombe, Greg; Gatt, Ruben; Griffin, Anselm C; Richardson, Robert M; Scarpa, Fabrizio; Hamerton, Ian; Grima, Joseph N

    2016-08-10

    We describe a new class of negative Poisson's ratio (NPR) open cell PU-PE foams produced by blocking the shape memory effect in the polymer. Contrary to classical NPR open cell thermoset and thermoplastic foams that return to their auxetic phase after reheating (and therefore limit their use in technological applications), this new class of cellular solids has a permanent negative Poisson's ratio behavior, generated through multiple shape memory (mSM) treatments that lead to a fixity of the topology of the cell foam. The mSM-NPR foams have Poisson's ratio values similar to the auxetic foams prior their return to the conventional phase, but compressive stress-strain curves similar to the ones of conventional foams. The results show that by manipulating the shape memory effect in polymer microstructures it is possible to obtain new classes of materials with unusual deformation mechanisms. PMID:27377708

  9. Interactive and Indirect Effects of Anxiety and Negative Urgency on Alcohol-Related Problems

    PubMed Central

    Menary, Kyle R.; Corbin, William R.; Leeman, Robert F.; Fucito, Lisa M.; Toll, Benjamin A.; DeMartini, Kelly; O’Malley, Stephanie S.

    2015-01-01

    Background Although drinking for tension reduction has long been posited as a risk factor for alcohol-related problems, studies investigating anxiety in relation to risk for alcohol problems have returned inconsistent results, leading researchers to search for potential moderators. Negative urgency (the tendency to become behaviorally dysregulated when experiencing negative affect) is a potential moderator of theoretical interest because it may increase risk for alcohol problems among those high in negative affect. The present study tested a cross-sectional mediated moderation hypothesis whereby an interactive effect of anxiety and negative urgency on alcohol problems is mediated through coping-related drinking motives. Method The study utilized baseline data from a hazardously drinking sample of young adults (N = 193) evaluated for participation in a randomized controlled trial of naltrexone and motivational interviewing for drinking reduction. Results The direct effect of anxiety on physiological dependence symptoms was moderated by negative urgency such that the positive association between anxiety and physiological dependence symptoms became stronger as negative urgency increased. Indirect effects of anxiety and negative urgency on alcohol problems (operating through coping motives) were also observed. Conclusions Although results of the current cross-sectional study require replication using longitudinal data, the findings suggest that the simultaneous presence of anxiety and negative urgency may be an important indicator of risk for AUDs via both direct interactive effects and indirect additive effects operating through coping motives. These findings have potentially important implications for prevention/intervention efforts for individuals who become disinhibited in the context of negative emotional states. PMID:26031346

  10. The negative priming effect in cognitive conflict processing.

    PubMed

    Pan, Fada; Shi, Liang; Lu, Qingyun; Wu, Xiaogang; Xue, Song; Li, Qiwei

    2016-08-15

    The present study used event-related potentials (ERPs) to investigate the specific physiological mechanisms underlying the negative nature of cognitive conflict and its influence on affective word evaluations. The present study used an affective priming paradigm where Stroop stimuli were presented for 200ms after which affective target words had to be evaluated as being positive or negative. Behavioral results showed that reaction times (RTs) were shorter for positive targets following congruent primes relative to incongruent primes, and for negative targets following incongruent primes relative to congruent primes. The ERP results showed that the N2 amplitude (200-300ms) for incongruent stimuli was significantly larger than for congruent stimuli in the Stroop task, which indicated a significant conflict effect. Moreover, the N400 amplitude (300-500ms) was smaller for negative words following incongruent primes relative to congruent primes, and for positive words following congruent primes relative to incongruent primes. The results demonstrated that cognitive conflict modulated both behavioral and electrophysiological correlates of subsequent emotional processing, consistent with its hypothesized registration as an aversive signal. PMID:27268038

  11. Priming effects in Haplic Luvisol after different substrate additions

    NASA Astrophysics Data System (ADS)

    Bogomolova, I.; Blagodatskaya, E.; Blagodatsky, S.; Kuzyakov, Y.

    2009-04-01

    Although soils contain considerable amounts of soil organic carbon (SOC), most of it is not easily available for microorganisms. Addition of various substrates to soil (for example, plant residues, root exudates) may affect SOC mineralization. The addition of mineral nutrients, especially N, may also affect C turnover and so change the mineralization rate of SOC. Such short-term changes in mineralization of organic substance of soil were termed as "priming-effects" (Bingemann et al., 1953). Priming effect leads to additional mineralization of SOC (van Elsas and van Overbeek, 1993). It has been shown that not only plant residues induce priming effects (Sauerbeck, 1966; Stemmer et al., 1999; Bell et al., 2003), but also easily available substrates such as sugars or amino acids, which are present in soil solutions and root exudates (Vasconcellos, 1994; Shen and Bartha, 1997; Hamer and Marschner, 2002). Since easily available substrates may not only accelerate SOC mineralization, but also may retard it, Kuzyakov et al. (2000) differentiated between positive and negative priming effects. It is not clear until now, how long priming effects persists in soil after substrate addition, and if they are induced every time when a substrate becomes available in soil. So, the aim of this study was to evaluate effects of glucose and plant residues on SOM decomposition, and influence of glucose on plant residues decomposition in soil. The experimental layout was designed as two factor experiment: 1) plant residues and 2) available substrate amendment. Maize shoot residues (50 mg added to 5 g soil) were 14C labeled (9•104 DPM per 5 g soil). Soil without of any plant residues served as a control for this treatment. Two levels of D (+) glucose as easily available substrates were added after three months of pre-incubation of soil samples with maize residues: 0.009 mg glucose C g-1 soil and 0.225 mg glucose C g-1 soil. The glucose was uniformly labelled with 14C (2.37•104 DPM per 5

  12. Positive Effects of Talking about the Negative: Family Narratives of Negative Experiences and Preadolescents' Perceived Competence

    ERIC Educational Resources Information Center

    Marin, Kelly A.; Bohanek, Jennifer G.; Fivush, Robyn

    2008-01-01

    Family narratives about the past are an important context for the socialization of emotion, but relations between expression of negative emotion and children's emerging competence are conflicting. In this study, 24 middle-class two-parent families narrated a shared negative experience together and we examined the process (initiations and…

  13. Negative contributions to S in an effective field theory

    SciTech Connect

    Dobrescu, Bogdan A.; Terning, John

    1997-09-19

    We show that an effective field theory that includes non-standard couplings between the electroweak gauge bosons and the top and bottom quarks may yield negative contributions to both the S and T oblique radiative electroweak parameters. We find that such an effective field theory provides a better fit to data than the standard model (the {chi}{sup 2} per degree of freedom is half as large). We examine in some detail an illustrative model where the exchange of heavy scalars produces the correct type of non-standard couplings.

  14. Negative Effects of Psychological Treatments: An Exploratory Factor Analysis of the Negative Effects Questionnaire for Monitoring and Reporting Adverse and Unwanted Events

    PubMed Central

    Kottorp, Anders; Boettcher, Johanna; Andersson, Gerhard; Carlbring, Per

    2016-01-01

    Research conducted during the last decades has provided increasing evidence for the use of psychological treatments for a number of psychiatric disorders and somatic complaints. However, by focusing only on the positive outcomes, less attention has been given to the potential of negative effects. Despite indications of deterioration and other adverse and unwanted events during treatment, little is known about their occurrence and characteristics. Hence, in order to facilitate research of negative effects, a new instrument for monitoring and reporting their incidence and impact was developed using a consensus among researchers, self-reports by patients, and a literature review: the Negative Effects Questionnaire. Participants were recruited via a smartphone-delivered self-help treatment for social anxiety disorder and through the media (N = 653). An exploratory factor analysis was performed, resulting in a six-factor solution with 32 items, accounting for 57.64% of the variance. The derived factors were: symptoms, quality, dependency, stigma, hopelessness, and failure. Items related to unpleasant memories, stress, and anxiety were experienced by more than one-third of the participants. Further, increased or novel symptoms, as well as lack of quality in the treatment and therapeutic relationship rendered the highest self-reported negative impact. In addition, the findings were discussed in relation to prior research and other similar instruments of adverse and unwanted events, giving credence to the items that are included. The instrument is presently available in eleven different languages and can be freely downloaded and used from www.neqscale.com. PMID:27331907

  15. Negative Effects of Psychological Treatments: An Exploratory Factor Analysis of the Negative Effects Questionnaire for Monitoring and Reporting Adverse and Unwanted Events.

    PubMed

    Rozental, Alexander; Kottorp, Anders; Boettcher, Johanna; Andersson, Gerhard; Carlbring, Per

    2016-01-01

    Research conducted during the last decades has provided increasing evidence for the use of psychological treatments for a number of psychiatric disorders and somatic complaints. However, by focusing only on the positive outcomes, less attention has been given to the potential of negative effects. Despite indications of deterioration and other adverse and unwanted events during treatment, little is known about their occurrence and characteristics. Hence, in order to facilitate research of negative effects, a new instrument for monitoring and reporting their incidence and impact was developed using a consensus among researchers, self-reports by patients, and a literature review: the Negative Effects Questionnaire. Participants were recruited via a smartphone-delivered self-help treatment for social anxiety disorder and through the media (N = 653). An exploratory factor analysis was performed, resulting in a six-factor solution with 32 items, accounting for 57.64% of the variance. The derived factors were: symptoms, quality, dependency, stigma, hopelessness, and failure. Items related to unpleasant memories, stress, and anxiety were experienced by more than one-third of the participants. Further, increased or novel symptoms, as well as lack of quality in the treatment and therapeutic relationship rendered the highest self-reported negative impact. In addition, the findings were discussed in relation to prior research and other similar instruments of adverse and unwanted events, giving credence to the items that are included. The instrument is presently available in eleven different languages and can be freely downloaded and used from www.neqscale.com. PMID:27331907

  16. Character of the opposition effect and negative polarization

    NASA Technical Reports Server (NTRS)

    Pieters, Carle M.; Shkuratov, Yu. G.; Stankevich, D. G.

    1991-01-01

    Photometric and polarimetric properties at small phase angles were measured for silicates with controlled surface properties in order to distinguish properties that are associated with surface reflection from those that are associated with multiple scattering from internal grain boundaries. These data provide insight into the causes and conditions of photometric properties observed at small phase angles for dark bodies of the solar system. Obsidian was chosen to represent a silicate dielectric with no internal scattering boundaries. Because obsidian is free of internal scatterers, light reflected from both the rough and smooth obsidian samples is almost entirely single and multiple Fresnel reflections form surface facets with no body component. Surface structure alone cannot produce an opposition effect. Comparison of the obsidian and basalt results indicates that for an opposition effect to occur, surface texture must be both rough and contain internal scattering interfaces. Although the negative polarization observed for the obsidian samples indicates single and multiple reflections are part of negative polarization, the longer inversion angle of the multigrain inversion samples implies that internal reflections must also contribute a significant negative polarization component.

  17. How Do We Learn in a Negative Mood? Effects of a Negative Mood on Transfer and Learning

    ERIC Educational Resources Information Center

    Brand, Serge; Reimer, Torsten; Opwis, Klaus

    2007-01-01

    Findings show that both positive and negative mood may hinder or promote information processing. In two experiments, we show that negative mood impairs transfer effects and learning. In the first experiment, N = 54 participants drawn from a training course for the Swiss Corps of Fortification Guards first learned to solve the three- and four-disk…

  18. Positive and negative recency effects in retirement savings decisions.

    PubMed

    Rieskamp, Jörg

    2006-12-01

    Retirement savings decisions can be influenced by the fund composition of the retirement savings plan. In 2 experiments, strong composition effects were observed, with a larger percentage of resources being invested in stock funds when more stock than bond funds were offered. Although participants changed their allocations repeatedly, the opportunity to learn did not alter the composition effects. Learning processes led to positive and negative recency effects as well, providing evidence that allocations were strongly influenced by the recent performance of the different allocation options. Two learning models were tested to explain these learning processes. The first, a local adaptation learning model, assumes that people change their behavior on the basis of recent experience, whereas the second, a reinforcement learning model, assumes that decisions are made on the basis of the totality of accumulated experience. The local adaptation model was more accurate in predicting allocation decisions, in explaining positive and negative recency effects, and in showing why composition effects are not overcome by learning. PMID:17154772

  19. The Negative Effective Magnetic Pressure in Stratified Forced Turbulence

    NASA Astrophysics Data System (ADS)

    Brandenburg, Axel; Kemel, Koen; Kleeorin, Nathan; Rogachevskii, Igor

    2012-04-01

    To understand the basic mechanism of the formation of magnetic flux concentrations, we determine by direct numerical simulations the turbulence contributions to the mean magnetic pressure in a strongly stratified isothermal layer with large plasma beta, where a weak uniform horizontal mean magnetic field is applied. The negative contribution of turbulence to the effective mean magnetic pressure is determined for strongly stratified forced turbulence over a range of values of magnetic Reynolds and Prandtl numbers. Small-scale dynamo action is shown to reduce the negative effect of turbulence on the effective mean magnetic pressure. However, the turbulence coefficients describing the negative effective magnetic pressure phenomenon are found to converge for magnetic Reynolds numbers between 60 and 600, which is the largest value considered here. In all these models, the turbulent intensity is arranged to be nearly independent of height, so the kinetic energy density decreases with height due to the decrease in density. In a second series of numerical experiments, the turbulent intensity increases with height such that the turbulent kinetic energy density is nearly independent of height. Turbulent magnetic diffusivity and turbulent pumping velocity are determined with the test-field method for both cases. The vertical profile of the turbulent magnetic diffusivity is found to agree with what is expected based on simple mixing length expressions. Turbulent pumping is shown to be down the gradient of turbulent magnetic diffusivity, but it is twice as large as expected. Corresponding numerical mean-field models are used to show that a large-scale instability can occur in both cases, provided the degree of scale separation is large enough and hence the turbulent magnetic diffusivity small enough.

  20. Context-specific control and the Stroop negative priming effect.

    PubMed

    Milliken, Bruce; Thomson, David R; Bleile, Karmen; MacLellan, Ellen; Giammarco, Maria

    2012-01-01

    The present study highlights the utility of context-specific learning for different probe types in accounting for the commonly observed dependence of negative priming on probe selection. Using a Stroop priming procedure, Experiments 1a and 1b offered a demonstration that Stroop priming effects can differ qualitatively for selection and no-selection probes when probe selection is manipulated between subjects, but not when it is manipulated randomly from trial to trial within subject (see also Moore, 1994). In Experiments 2 and 3, selection and no-selection probes served as two contexts that varied randomly from trial to trial, but for which proportion repeated was manipulated separately. A context-specific proportion repeated effect was observed in Experiment 2, characterized by modest quantitative shifts in the repetition effects as a function of the context-specific proportion repeated manipulation. However, with a longer intertrial interval in Experiment 3, a context-specific proportion repeated manipulation that focused on the no-selection probes changed the repetition effect qualitatively, from negative priming when the proportion repeated was .25 to positive priming when the proportion repeated was .75. The results are discussed with reference to the role of rapid, context-specific learning processes in the integration of prior experiences with current perception and action. PMID:22502818

  1. The effect of negative affect on cognition: Anxiety, not anger, impairs executive function.

    PubMed

    Shields, Grant S; Moons, Wesley G; Tewell, Carl A; Yonelinas, Andrew P

    2016-09-01

    It is often assumed that negative affect impairs the executive functions that underlie our ability to control and focus our thoughts. However, support for this claim has been mixed. Recent work has suggested that different negative affective states like anxiety and anger may reflect physiologically separable states with distinct effects on cognition. However, the effects of these 2 affective states on executive function have never been assessed. As such, we induced anxiety or anger in participants and examined the effects on executive function. We found that anger did not impair executive function relative to a neutral mood, whereas anxiety did. In addition, self-reports of induced anxiety, but not anger, predicted impairments in executive function. These results support functional models of affect and cognition, and highlight the need to consider differences between anxiety and anger when investigating the influence of negative affect on fundamental cognitive processes such as memory and executive function. (PsycINFO Database Record PMID:27100367

  2. Double jeopardy! The additive consequences of negative affect on performance-monitoring decrements following traumatic brain injury.

    PubMed

    Larson, Michael J; Kaufman, David A S; Kellison, Ida L; Schmalfuss, Ilona M; Perlstein, William M

    2009-07-01

    Survivors of severe traumatic brain injury (TBI) are at increased risk for emotional sequelae. The current study utilized the error-related negativity (ERN) and posterror positivity (Pe) components of the event-related potential (ERP) to test the hypothesis that negative affect disproportionately impairs performance-monitoring following severe TBI. High-density ERPs were acquired while 20 survivors of severe TBI and 20 demographically matched controls performed a single-trial Stroop task. Response-locked ERPs were separately averaged for correct and error trials. Negative affect was measured as the single latent factor of measures of depression and anxiety. Groups did not differ on overall level of negative affect. Control and TBI participants did not differ on error rates as a function of negative affect, but differed in response times. ERP results revealed disproportionately smaller ERN amplitudes in participants with TBI relative to controls as a function of negative affect. Pe amplitude did not differ between groups. Negative affect inversely correlated with ERN amplitude in TBI but not control participants. Overall, results support a "double jeopardy" hypothesis of disproportionate impairments in performance monitoring when negative affect is overlaid on severe TBI. PMID:19586208

  3. Hostile attributional bias, negative emotional responding, and aggression in adults: moderating effects of gender and impulsivity.

    PubMed

    Chen, Pan; Coccaro, Emil F; Jacobson, Kristen C

    2012-01-01

    The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were explored. Multilevel models were fitted to data from 2,749 adult twins aged 20-55 from the PennTwins cohort. HAB was positively associated with all four forms of aggression. There was also a significant interaction between impulsivity and HAB for general aggression. Specifically, the relationship between HAB and general aggression was only significant for individuals with average or above-average levels of impulsivity. Negative emotional responding was also found to predict all measures of aggression, although in different ways. Anger was positively associated with all forms of aggression, whereas embarrassment/upset predicted decreased levels of general, physical, and verbal aggression but increased levels of relational aggression. The associations between negative emotional responding and aggression were generally stronger for males than females. The current study provides evidence for the utility of HAB and negative emotional responding as predictors of adult aggression and further suggests that gender and impulsivity may moderate their links with aggression. PMID:24833604

  4. Negative electrocaloric effect in antiferroelectric PbZrO3

    NASA Astrophysics Data System (ADS)

    Pirc, R.; Rožič, B.; Koruza, J.; Malič, B.; Kutnjak, Z.

    2014-07-01

    The dielectric and thermal properties of a typical antiferroelectric (AFE) material are investigated by minimising numerically the free energy as given by the Kittel model of AFEs. The phase line of second-order phase transitions in the E\\text{-}T phase diagram is shown to change to a first-order line at the tricritical point T3cp, E3cp. The static dielectric susceptibility and the electrocaloric (EC) effect are calculated as a function of temperature and the applied electric field E. It is found that in a given range of electric fields and temperatures the EC effect has negative values but generally becomes positive above the AFE ordering temperature T0. The dielectric susceptibility shows characteristic peaks at the phase transitions between the field-induced polar and the AFE antipolar phase, and diverges at the tricritical point. We present experimental results for a negative EC effect, which have been obtained by direct EC measurements in PbZrO3 ceramics, and agree qualitatively with the above model.

  5. Neonatal Handling: An Overview of the Positive and Negative Effects

    PubMed Central

    Raineki, Charlis; Lucion, Aldo B.; Weinberg, Joanne

    2016-01-01

    As one of the first rodent models designed to investigate the effects of early-life experiences, the neonatal handling paradigm has helped us better understand how subtle changes in the infant environment can powerfully drive neurodevelopment of the immature brain in typical or atypical trajectories. Here, we review data from more than 50 years demonstrating the compelling effects of neonatal handling on behavior, physiology, and neural function across the lifespan. Moreover, we present data that challenge the classical view of neonatal handling as an animal model that results only in positive/beneficial outcomes. Indeed, the overall goal of this review is to offer the suggestion that the effects of early-life experiences—including neonatal handling—are nuanced rather than unidirectional. Both beneficial and negative outcomes may occur, depending on the parameters of testing, sex of the subject, and neurobehavioral system analyzed. PMID:25132525

  6. Regulation of positive and negative emotion: effects of sociocultural context

    PubMed Central

    Snyder, Sara A.; Heller, S. Megan; Lumian, Daniel S.; McRae, Kateri

    2013-01-01

    Previous research has demonstrated that the use of emotion regulation strategies can vary by sociocultural context. In a previous study, we reported changes in the use of two different emotion regulation strategies at an annual alternative cultural event, Burning Man (McRae et al., 2011). In this sociocultural context, as compared to typically at home, participants reported less use of expressive suppression (a strategy generally associated with maladaptive outcomes), and greater use of cognitive reappraisal (a strategy generally associated with adaptive outcomes). What remained unclear was whether these changes in self-reported emotion regulation strategy use were characterized by changes in the regulation of positive emotion, negative emotion, or both. We addressed this issue in the current study by asking Burning Man participants separate questions about positive and negative emotion. Using multiple datasets, we replicated our previous findings, and found that the decreased use of suppression is primarily driven by reports of decreased suppression of positive emotion at Burning Man. By contrast, the increased use of reappraisal is not characterized by differential reappraisal of positive and negative emotion at Burning Man. Moreover, we observed novel individual differences in the magnitude of these effects. The contextual changes in self-reported suppression that we observe are strongest for men and younger participants. For those who had previously attended Burning Man, we observed lower levels of self-reported suppression in both sociocultural contexts: Burning Man and typically at home. These findings have implications for understanding the ways in which certain sociocultural contexts may decrease suppression, and possibly minimize its associated maladaptive effects. PMID:23840191

  7. Effects of Efflux Pump Inhibitors on Colistin Resistance in Multidrug-Resistant Gram-Negative Bacteria.

    PubMed

    Ni, Wentao; Li, Yanjun; Guan, Jie; Zhao, Jin; Cui, Junchang; Wang, Rui; Liu, Youning

    2016-05-01

    We tested the effects of various putative efflux pump inhibitors on colistin resistance in multidrug-resistant Gram-negative bacteria. Addition of 10 mg/liter cyanide 3-chlorophenylhydrazone (CCCP) to the test medium could significantly decrease the MICs of colistin-resistant strains. Time-kill assays showed CCCP could reverse colistin resistance and inhibit the regrowth of the resistant subpopulation, especially in Acinetobacter baumannii and Stenotrophomonas maltophilia These results suggest colistin resistance in Gram-negative bacteria can be suppressed and reversed by CCCP. PMID:26953203

  8. Negative effects of item repetition on source memory

    PubMed Central

    Yi, Do-Joon; Raye, Carol L.; Johnson, Marcia K.

    2013-01-01

    In the present study, we explored how item repetition affects source memory for new item–feature associations (picture–location or picture–color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item–source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item–source associations will be encoded. PMID:22411165

  9. Negative congruency effects: a test of the inhibition account.

    PubMed

    Kiesel, Andrea; Berner, Michael P; Kunde, Wilfried

    2008-03-01

    Masked priming experiments occasionally revealed surprising effects: Participants responded slower for congruent compared to incongruent primes. This negative congruency effect (NCE) was ascribed to inhibition of prime-induced activation [Eimer, M., & Schlaghecken, F. (2003). Response faciliation and inhibition in subliminal priming. Biological Psychology, 64, 7-26.] that sets in if the prime activation is sufficiently strong. The current study tests this assumption by implementing manipulations designed to vary the amount of prime-induced activation in three experiments. In Experiments 1 and 3, NCEs were observed despite reduced prime-induced activation. Experiment 2 revealed no NCE with at least similar prime strength. Thus, the amount of prime activation did not predict whether or not NCEs occurred. The findings are discussed with regard to the inhibition account and the recently proposed account of mask-induced activation [cf. Lleras, A., & Enns, J. T. (2004). Negative compatibility or object updating? A cautionary tale of mask-dependent priming. Journal of Experimental Psychology: General, 133, 475-493; Verleger, R., Jaskowski, P., Aydemir, A., van der Lubbe, R. H. J., & Groen, M. (2004). Qualitative differences between conscious and nonconscious processing? On inverse priming induced by masked arrows. Journal of Experimental Psychology: General, 133, 494-515]. PMID:17188514

  10. Implementation of Complexity Analyzing Based on Additional Effect

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Li, Na; Liang, Yanhong; Liu, Fang

    According to the Complexity Theory, there is complexity in the system when the functional requirement is not be satisfied. There are several study performances for Complexity Theory based on Axiomatic Design. However, they focus on reducing the complexity in their study and no one focus on method of analyzing the complexity in the system. Therefore, this paper put forth a method of analyzing the complexity which is sought to make up the deficiency of the researches. In order to discussing the method of analyzing the complexity based on additional effect, this paper put forth two concepts which are ideal effect and additional effect. The method of analyzing complexity based on additional effect combines Complexity Theory with Theory of Inventive Problem Solving (TRIZ). It is helpful for designers to analyze the complexity by using additional effect. A case study shows the application of the process.

  11. Effects of fuel and additives on combustion chamber deposits

    SciTech Connect

    Jackson, M.M.; Pocinki, S.B.

    1994-10-01

    The effects of gasoline composition, as represented in typical regular and premium unleaded gasolines and fuel additives, on Combustion Chamber Deposits (CCD) were investigated in BMW and Ford tests. In addition, the influences of engine lubricant oil and ethanol oxygenate on CCD were examined in Ford 2.3L engine dynamometer tests. Also, additive effects of packages based on mineral oil fluidizers versus synthetic fluidizers were studied in several different engines for CCD. Finally, a new method for evaluating the effect of fluidizers on valve sticking is introduced. 6 refs., 16 figs., 14 tabs.

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

    PubMed

    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. PMID:26226491

  13. Effect of additives on the purification of urease

    NASA Astrophysics Data System (ADS)

    Yu, X.; Wang, J.; Ulrich, J.

    2015-12-01

    The effect of additives on the purification of proteins was investigated. The target protein studied here is the enzyme urease. Studies on the purification of urease from jack bean meal were carried out. 32% (v/v) acetone was utilized to extract urease from the jack bean meal. Further purification by crystallization with the addition of 2-mercaptoethanol and EDTA disodium salt dehydrate was carried out. It was found out that the presence of additives can affect the selectivity of the crystallization. Increases in both purity and yield of the urease after crystallization were observed in the presence of additives, which were proven using both SDS-PAGE and activity. Urease crystals with a yield of 69.9% and a purity of 85.1% were obtained in one crystallization step in the presence of additives. Furthermore, the effect of additives on the thermodynamics and kinetics of urease crystallization was studied.

  14. Polymer Photooxidation: An Experiment to Demonstrate the Effect of Additives.

    ERIC Educational Resources Information Center

    Allen, Norman S.; McKellar, John F.

    1979-01-01

    This undergraduate experiment shows that the inclusion of an appropriate additive can have a very marked effect on the physical properties of a polymer. The polymer used is polypropylene and the additives are 2-hydroxy-4-octyloxy-benzophenone and benzophenone. (BB)

  15. Unraveling Additive from Nonadditive Effects Using Genomic Relationship Matrices

    PubMed Central

    Muñoz, Patricio R.; Resende, Marcio F. R.; Gezan, Salvador A.; Resende, Marcos Deon Vilela; de los Campos, Gustavo; Kirst, Matias; Huber, Dudley; Peter, Gary F.

    2014-01-01

    The application of quantitative genetics in plant and animal breeding has largely focused on additive models, which may also capture dominance and epistatic effects. Partitioning genetic variance into its additive and nonadditive components using pedigree-based models (P-genomic best linear unbiased predictor) (P-BLUP) is difficult with most commonly available family structures. However, the availability of dense panels of molecular markers makes possible the use of additive- and dominance-realized genomic relationships for the estimation of variance components and the prediction of genetic values (G-BLUP). We evaluated height data from a multifamily population of the tree species Pinus taeda with a systematic series of models accounting for additive, dominance, and first-order epistatic interactions (additive by additive, dominance by dominance, and additive by dominance), using either pedigree- or marker-based information. We show that, compared with the pedigree, use of realized genomic relationships in marker-based models yields a substantially more precise separation of additive and nonadditive components of genetic variance. We conclude that the marker-based relationship matrices in a model including additive and nonadditive effects performed better, improving breeding value prediction. Moreover, our results suggest that, for tree height in this population, the additive and nonadditive components of genetic variance are similar in magnitude. This novel result improves our current understanding of the genetic control and architecture of a quantitative trait and should be considered when developing breeding strategies. PMID:25324160

  16. Effects of Experimental Nitrogen and Phosphorus Addition on Litter Decomposition in an Old-Growth Tropical Forest

    PubMed Central

    Chen, Hao; Dong, Shaofeng; Liu, Lei; Ma, Chuan; Zhang, Tao; Zhu, Xiaomin; Mo, Jiangming

    2013-01-01

    The responses of litter decomposition to nitrogen (N) and phosphorus (P) additions were examined in an old-growth tropical forest in southern China to test the following hypotheses: (1) N addition would decrease litter decomposition; (2) P addition would increase litter decomposition, and (3) P addition would mitigate the inhibitive effect of N addition. Two kinds of leaf litter, Schima superba Chardn. & Champ. (S.S.) and Castanopsis chinensis Hance (C.C.), were studied using the litterbag technique. Four treatments were conducted at the following levels: control, N-addition (150 kg N ha−1 yr−1), P-addition (150 kg P ha−1 yr−1) and NP-addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). While N addition significantly decreased the decomposition of both litters, P addition significantly inhibited decomposition of C.C., but did not affect the decomposition of S.S. The negative effect of N addition on litter decomposition might be related to the high N-saturation in this old-growth tropical forest; however, the negative effect of P addition might be due to the suppression of “microbial P mining”. Significant interaction between N and P addition was found on litter decomposition, which was reflected by the less negative effect in NP-addition plots than those in N-addition plots. Our results suggest that P addition may also have negative effect on litter decomposition and that P addition would mitigate the negative effect of N deposition on litter decomposition in tropical forests. PMID:24391895

  17. Mathematics Anxiety Effects in Simple and Complex Addition.

    ERIC Educational Resources Information Center

    Faust, Michael W.; And Others

    1996-01-01

    Reports three experiments that show that anxiety effects were prominent in two-column addition problems, especially those involving carrying. Elaborates a theory of mathematics anxiety. Contains 50 references. (SKS)

  18. Effects of various additives on sintering of aluminum nitride

    NASA Technical Reports Server (NTRS)

    Komeya, K.; Inoue, H.; Tsuge, A.

    1982-01-01

    Effects of thirty additives on sintering A/N were investigated. The addition of alkali earth oxides and rare earth oxides gave fully densified aluminum nitride. This is due to the formation of nitrogen-containing aluminate liquid in the system aluminum nitride-alkali earth oxides or rare earth oxides. Microstructural studies of the sintered specimens with the above two types of additives suggested that the densification was due to the liquid phase sintering. Additions of silicon compounds resulted in poor densification by the formation of highly refractory compounds such as A/N polytypes.

  19. Potentiation of photoinactivation of Gram-positive and Gram-negative bacteria mediated by six phenothiazinium dyes by addition of azide ion

    PubMed Central

    Kasimova, Kamola R; Sadasivam, Magesh; Landi, Giacomo; Sarna, Tadeusz; Hamblin, Michael R.

    2014-01-01

    Antimicrobial photodynamic inactivation (APDI) using phenothiazinium dyes is mediated by reactive oxygen species consisting of a combination of singlet oxygen (quenched by azide), hydroxyl radicals and other reactive oxygen species. We recently showed that addition of sodium azide paradoxically potentiated APDI of Gram-positive and Gram-negative bacteria using methylene blue as the photosensitizer, and this was due to electron transfer to the dye triplet state from azide anion, producing azidyl radical. Here we compare this effect using six different homologous phenothiazinium dyes: methylene blue, toluidine blue O, new methylene blue, dimethylmethylene blue, azure A, and azure B. We found both significant potentiation (up to 2 logs) and also significant inhibition (>3 logs) of killing by adding 10 mM azide depending on Gram classification, washing the dye from the cells, and dye structure. Killing of E. coli was potentiated with all 6 dyes after a wash, while S. aureus killing was only potentiated by MB and TBO with a wash and DMMB with no wash. More lipophilic dyes (higher log P value, such as DMMB) were more likely to show potentiation. We conclude that the Type I photochemical mechanism (potentiation with azide) likely depends on the microenvironment, i.e. higher binding of dye to bacteria. Bacterial dye-binding is thought to be higher with Gram-negative compared to Gram-positive bacteria, when unbound dye has been washed away, and with more lipophilic dyes. PMID:25177833

  20. Effects of some polymeric additives on the cocrystallization of caffeine

    NASA Astrophysics Data System (ADS)

    Chung, Jihae; Kim, Il Won

    2011-11-01

    Effects of polymeric additives on the model cocrystallization were examined. The model cocrystal was made from caffeine and oxalic acid, and poly(ethylene glycol) (PEG), poly( L-lactide) (PLLA), poly(ɛ-caprolactone) (PCL), and poly(acrylic acid) (PAA) were the additives. The cocrystals were formed as millimeter-sized crystals without additives, and they became microcrystals with PLLA and PCL, and nanocrystals with PAA. XRD and IR revealed that the cocrystal structure was unchanged despite the strong effects of the additives on the crystal morphology, although some decrease in crystallinity was observed with PAA as confirmed by DSC. The DSC study also showed that the cocrystal melted and recrystallized to form α-caffeine upon heating. The present study verified that the polymeric additives can be utilized to modulate the size and morphology of the cocrystals without interfering the intermolecular interactions essential to the integrity of the cocrystal structures.

  1. Acoustic field effects on a negative corona discharge

    NASA Astrophysics Data System (ADS)

    Bálek, R.; Červenka, M.; Pekárek, S.

    2014-06-01

    For a negative corona discharge under atmospheric pressure in different regimes, we investigated the effects of an acoustic field both on its electrical parameters and on the change in its visual appearance. We found that the application of an acoustic field on the true corona discharge, for particular currents, decreases the discharge voltage. The application of an acoustic field on the discharge in the filamentary streamer regime substantially extends the range of currents for which the discharge voltage remains more or less constant, i.e. it allows a substantial increase in the power delivered to the discharge. The application of an acoustic field on the discharge causes the discharge to spread within the discharge chamber and consequently, a highly reactive non-equilibrium plasma is created throughout the inter-electrode space. Finally, our experimental apparatus radiates almost no acoustic energy from the discharge chamber.

  2. The negative effect of hypokinesia involving injury and preventive measures

    NASA Technical Reports Server (NTRS)

    Izakson, K. A.

    1981-01-01

    The optimum length of bed rest for athletes suffering from broken bones is considered. Negative effects of hypokinesia induced by bed rest include general weakness and deconditioning of the muscles as well as sleeplessness, headaches, muscle pain, constipation, unstable pulse and arterial pressure, and changes in reflexes. This is considered to be the result of a vegetative dysfunction induced by the decreased flow of nerve impulses and a decrease in interoceptive and exteroceptive signals. The briefest possible period of bed rest, followed by an increase in motor activity, the prescription of a large quantity of LFK, and an active program of physical therapy are recommended. The symptomology associated with hypokinesia disappears after one month of free motor activity.

  3. Additive effects on the toughening of unsaturated polyester resins

    SciTech Connect

    Suspene, L.; Yang, Y.S.; Pascault, J.P.

    1993-12-31

    An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins. 49 refs., 13 figs., 3 tabs.

  4. The effect of additives on lime dissolution rates. Final report

    SciTech Connect

    Khang, S.J.

    1996-07-31

    Based on the previous years` studies concerning the efficiency of SO{sub 2} removal by spray dryers with high sulfur coal flue gas, the work for year five included investigations of lime dissolution rates at different slaking conditions and with the effect of additives. The prominent additives that have significant effects on lime dissolution rates were tested with the mini pilot spray drying absorber to see their effects on spray drying desulfurization applications. The mechanisms of these additive effects along with the properties of hygroscopic additives have been discussed and incorporated into the spray drying desulfurization model ``SPRAYMOD-M.`` Slaking conditions are very important factors in producing high quality lime slurry in spray drying desulfurization processes. At optimal slaking conditions, the slaked lime particles are very fine (3-5{mu}m) and the slaked lime has high BET surface areas which are beneficial to the desulfurization. The slaked lime dissolution rate experiments in our study are designed to determine how much lime can dissolve in a unit time if the initial lime surface area is kept constant. The purpose of the dissolution rate study for different additives is to find those effective additives that can enhance lime dissolution rates and to investigate the mechanisms of the dissolution rate enhancement properties for these additives. The applications of these additives on spray drying desulfurization are to further verify the theory that dissolution rate is a rate limiting step in the whole spray drying desulfurization process as well as to test the feasibility of these additives on enhancing SO{sub 2} removal in spray dryers.

  5. POEM: Identifying Joint Additive Effects on Regulatory Circuits

    PubMed Central

    Botzman, Maya; Nachshon, Aharon; Brodt, Avital; Gat-Viks, Irit

    2016-01-01

    Motivation: Expression Quantitative Trait Locus (eQTL) mapping tackles the problem of identifying variation in DNA sequence that have an effect on the transcriptional regulatory network. Major computational efforts are aimed at characterizing the joint effects of several eQTLs acting in concert to govern the expression of the same genes. Yet, progress toward a comprehensive prediction of such joint effects is limited. For example, existing eQTL methods commonly discover interacting loci affecting the expression levels of a module of co-regulated genes. Such “modularization” approaches, however, are focused on epistatic relations and thus have limited utility for the case of additive (non-epistatic) effects. Results: Here we present POEM (Pairwise effect On Expression Modules), a methodology for identifying pairwise eQTL effects on gene modules. POEM is specifically designed to achieve high performance in the case of additive joint effects. We applied POEM to transcription profiles measured in bone marrow-derived dendritic cells across a population of genotyped mice. Our study reveals widespread additive, trans-acting pairwise effects on gene modules, characterizes their organizational principles, and highlights high-order interconnections between modules within the immune signaling network. These analyses elucidate the central role of additive pairwise effect in regulatory circuits, and provide computational tools for future investigations into the interplay between eQTLs. Availability: The software described in this article is available at csgi.tau.ac.il/POEM/. PMID:27148351

  6. Study of electrochemically active carbon, Ga2O3 and Bi2O3 as negative additives for valve-regulated lead-acid batteries working under high-rate, partial-state-of-charge conditions

    NASA Astrophysics Data System (ADS)

    Zhao, Li; Chen, Baishuang; Wu, Jinzhu; Wang, Dianlong

    2014-02-01

    Electrochemically active carbon (EAC), Gallium (III) oxide (Ga2O3) and Bismuth (III) oxide (Bi2O3) are used as the negative additives of valve-regulated lead-acid (VRLA) batteries to prolong the cycle life of VRLA batteries under high-rate partial-state-of-charge (HRPSoC) conditions, and their effects on the cycle life of VRLA batteries are investigated. It is found that the addition of EAC in negative active material can restrain the sulfation of the negative plates and prolong the cycle performance of VRLA batteries under HRPSoC conditions. It is also observed that the addition of Ga2O3 or Bi2O3 in EAC can effectively increase the overpotential of hydrogen evolution on EAC electrodes, and decrease the evolution rate of hydrogen. An appropriate addition amount of Ga2O3 or Bi2O3 in the negative plates of VRLA batteries can decrease the cut-off charging voltage, increase the cut-off discharging voltage, and prolong the cycle life of VRLA batteries under HRPSoC conditions. The battery added with 0.5% EAC and 0.01% Ga2O3 in negative active material shows a lowest cut-off charging voltage and a highest cut-off discharging voltage under HRPSoC conditions, and its' cycle life reaches about 8100 cycles which is at least three times longer than that without Ga2O3.

  7. The effect of lubricant additives on fretting wear

    NASA Astrophysics Data System (ADS)

    Qiu, Y.; Roylance, B. J.

    1992-10-01

    The effect of lubricant additives on fretting wear has been investigated using a ball-on-plate machine. The test results confirm that the antiwear additives, e.g. phospho-sulphurized terpene, sulphurized esters and sulphurized paraffins, are effective in reducing friction and wear. Examination of worn surfaces by optical and electron microscope inspection indicated the presence of thin films which had been deposited under fretting action when using oils containing these additives. Unlubricated fretting wear occurred in the scuffing region. In contrast, the lubricated fretting wear with the lubricating oils containing the antiwear additives took place in the mixed lubrication region. In lubricated fretting wear, the size of the wear particles was smaller than with dry fretting wear.

  8. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1990-07-01

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies of NO adsorption, reaction probing, study state rate measurement, and transient kinetic study. A better understanding of the role of additive on the synthesis reaction may allow us to sue chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas. (VC)

  9. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1990-07-01

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies of NO adsorption, reaction probing, study state rate measurement, and transient kinetic study. A better understanding of the role of additive on the synthesis reaction may allow us to use chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas.

  10. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1988-11-14

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies including temperature programmed desorption, infrared study of NO adsorption, reactive probing, steady state rate measurement, and transient kinetic study. A better understanding of the role of additive on the synthesis reaction may allow us to use chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas.

  11. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1990-11-01

    The objective of this research is to elucidate the role of additives on the ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies of NO adsorption, reaction probing, study state rate measurement, and transient kinetic study. A better understanding of the role of additive on the synthesis reaction may allow them to use chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas. 49 refs., 6 figs., 3 tabs.

  12. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.; Balakos, M.W.

    1991-09-20

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies of NO adsorption, reaction probing, study state rate measurement, and transient kinetic study. A better understanding of the role of additives on the synthesis reaction may allow us to use chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas. 27 refs. 7 figs., 2 tabs.

  13. Word Meaning Frequencies Affect Negative Compatibility Effects In Masked Priming.

    PubMed

    Brocher, Andreas; Koenig, Jean-Pierre

    2016-01-01

    Negative compatibility effects (NCEs)-that is, slower responses to targets in related than unrelated prime-target pairs, have been observed in studies using stimulus-response (S-R) priming with stimuli like arrows and plus signs. Although there is no consensus on the underlying mechanism, explanations tend to locate NCEs within the motor-response system. A characteristic property of perceptuo-motor NCEs is a biphasic pattern of activation: A brief period in which very briefly presented (typically) masked primes facilitate processing of related targets is followed by a phase of target processing impairment. In this paper, we present data that suggest that NCEs are not restricted to S-R priming with low-level visual stimuli: The brief (50 ms), backward masked (250 ms) presentation of ambiguous words (bank) leads to slower responses than baseline to words related to the more frequent (rob) but not less frequent meaning (swim). Importantly, we found that slowed responses are preceded by a short phase of response facilitation, replicating the biphasic pattern reported for arrows and plus signs. The biphasic pattern of priming and the fact that the NCEs were found only for target words that are related to their prime word's more frequent meaning has strong implications for any theory of NCEs that locate these effects exclusively within the motor-response system. PMID:27152129

  14. Word Meaning Frequencies Affect Negative Compatibility Effects In Masked Priming

    PubMed Central

    Brocher, Andreas; Koenig, Jean-Pierre

    2016-01-01

    Negative compatibility effects (NCEs)—that is, slower responses to targets in related than unrelated prime-target pairs, have been observed in studies using stimulus-response (S-R) priming with stimuli like arrows and plus signs. Although there is no consensus on the underlying mechanism, explanations tend to locate NCEs within the motor-response system. A characteristic property of perceptuo-motor NCEs is a biphasic pattern of activation: A brief period in which very briefly presented (typically) masked primes facilitate processing of related targets is followed by a phase of target processing impairment. In this paper, we present data that suggest that NCEs are not restricted to S-R priming with low-level visual stimuli: The brief (50 ms), backward masked (250 ms) presentation of ambiguous words (bank) leads to slower responses than baseline to words related to the more frequent (rob) but not less frequent meaning (swim). Importantly, we found that slowed responses are preceded by a short phase of response facilitation, replicating the biphasic pattern reported for arrows and plus signs. The biphasic pattern of priming and the fact that the NCEs were found only for target words that are related to their prime word’s more frequent meaning has strong implications for any theory of NCEs that locate these effects exclusively within the motor-response system. PMID:27152129

  15. Non-additive dietary effects in juvenile slider turtles, Trachemys scripta.

    PubMed

    Bouchard, Sarah S; Murphy, Amber K; Berry, Jennifer A

    2010-02-01

    Non-additive dietary effects occur when nutritional gains from a mixed diet are greater than or less than that predicted by summing the gains from individual diet items. Both positive and negative effects occur in adult slider turtles, Trachemys scripta. Such effects may also be important to juvenile T. scripta as they ontogenetically switch from carnivorous to herbivorous diets. The purpose of this study was to determine if juveniles experience non-additive effects and to assess the underlying mechanism. Two feeding trials were conducted. In Trial 1, juveniles were fed 100% duckweed, Lemna valdiviana, 100% grass shrimp, Palaemontes paludosus, or a mixed diet containing 81% duckweed and 19% shrimp. In Trial 2, juveniles were fed 100% duckweed, Lemna minor, 100% cricket, Acheta domesticus, or one of three mixed diets containing duckweed and cricket in varying percentages (22%, 39% and 66% cricket). Similar to adults, a negative non-additive effect was demonstrated on the 19% shrimp and 22% cricket diets. However, the positive effect found in adults was not observed. Intake varied dramatically between the plant and animal diets, resulting in differences in transit time that could explain the non-additive effect. These results offer some insight into understanding ontogenetic diet shifts in turtles. PMID:19931632

  16. Effects of Negative and Positive Evidence on Adult Word Learning

    ERIC Educational Resources Information Center

    Strapp, Chehalis M.; Helmick, Augusta L.; Tonkovich, Hayley M.; Bleakney, Dana M.

    2011-01-01

    This study compared negative and positive evidence in adult word learning, predicting that adults would learn more forms following negative evidence. Ninety-two native English speakers (32 men and 60 women [M[subscript age] = 20.38 years, SD = 2.80]), learned nonsense nouns and verbs provided within English frames. Later, participants produced…

  17. Negative space charge effects in photon-enhanced thermionic emission solar converters

    SciTech Connect

    Segev, G.; Weisman, D.; Rosenwaks, Y.; Kribus, A.

    2015-07-06

    In thermionic energy converters, electrons in the gap between electrodes form a negative space charge and inhibit the emission of additional electrons, causing a significant reduction in conversion efficiency. However, in Photon Enhanced Thermionic Emission (PETE) solar energy converters, electrons that are reflected by the electric field in the gap return to the cathode with energy above the conduction band minimum. These electrons first occupy the conduction band from which they can be reemitted. This form of electron recycling makes PETE converters less susceptible to negative space charge loss. While the negative space charge effect was studied extensively in thermionic converters, modeling its effect in PETE converters does not account for important issues such as this form of electron recycling, nor the cathode thermal energy balance. Here, we investigate the space charge effect in PETE solar converters accounting for electron recycling, with full coupling of the cathode and gap models, and addressing conservation of both electric and thermal energy. The analysis shows that the negative space charge loss is lower than previously reported, allowing somewhat larger gaps compared to previous predictions. For a converter with a specific gap, there is an optimal solar flux concentration. The optimal solar flux concentration, the cathode temperature, and the efficiency all increase with smaller gaps. For example, for a gap of 3 μm the maximum efficiency is 38% and the optimal flux concentration is 628, while for a gap of 5 μm the maximum efficiency is 31% and optimal flux concentration is 163.

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

    PubMed Central

    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. PMID:27144385

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

    PubMed

    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. PMID:27144385

  20. Spontaneous toroidal flow generation due to negative effective momentum diffusivity

    SciTech Connect

    McMillan, Ben F.

    2015-02-15

    Spontaneous structure formation, and in particular, zonal flows, is observed in a broad range of natural and engineered systems, often arising dynamically as the saturated state of a linear instability. Flows in tokamaks are known to self-organise on small scales, but large scale toroidal flows also arise even when externally applied torques are zero. This has previously been interpreted as the result of small externally imposed breaking of a symmetry. However, we show that for large enough field line pitch, a robust spontaneous symmetry breaking occurs, leading to the generation of strong toroidal flow structures; parameters are typical of Spherical Tokamak discharges with reversed shear profiles. The short wavelength dynamics are qualitatively similar to the growth of poloidal flow structures, and toroidal flow gradients nonlinearly saturate at levels where the shearing rate is comparable to linear growth rate. On long wavelengths, we measure Prandtl numbers of around zero for these systems, in conjunction with the formation of structured toroidal flows, and we show that this is consistent with a model of momentum transport where fluxes act to reinforce small flow gradients: the effective momentum diffusivity is negative. Toroidal flow structures are largely unaffected by collisional damping, so this may allow toroidal bulk flows of order the ion thermal velocity to be maintained with zero momentum input. This phenomenon also provides a mechanism for the generation of localised meso-scale structures like transport barriers.

  1. Effects of chemical additives on microbial enhanced oil recovery processes

    SciTech Connect

    Bryant, R.S.; Chase, K.L.; Bertus, K.M.; Stepp, A.K.

    1989-12-01

    An extensive laboratory study has been conducted to determine (1) the role of the microbial cells and products in oil displacement, (2) the relative rates of transport of microbial cells and chemical products from the metabolism of nutrient in porous media, and (3) the effects of chemical additives on the oil recovery efficiency of microbial formulations. This report describes experiments relating to the effects of additives on oil recovery efficiency of microbial formulations. The effects of additives on the oil recovery efficiency of microbial formulations were determined by conducting oil displacement experiments in 1-foot-long Berea sandstone cores. Sodium tripolyphosphate (STPP), a low-molecular-weight polyacrylamide polymer, a lignosulfonate surfactant, and sodium bicarbonate were added to a microbial formulation at a concentration of 1%. The effects of using these additives in a preflush prior to injection of the microbial formulation were also evaluated. Oil-displacement experiments with and without a sodium bicarbonate preflush were conducted in 4-foot-long Berea sandstone cores, and samples of in situ fluids were collected at various times at four intermediate points along the core. The concentrations of metabolic products and microbes in the fluid samples were determined. 9 refs., 22 figs., 8 tabs.

  2. Effects of age on white matter integrity and negative symptoms in schizophrenia

    PubMed Central

    Bijanki, Kelly Rowe; Hodis, Brendan; Magnotta, Vincent A.; Zeien, Eugene; Andreasen, Nancy C.

    2014-01-01

    The current study examined the relationship between white matter integrity as indexed by diffusion tensor imaging and negative symptom severity in schizophrenia. The current study included statistical controls for age effects on the relationship of interest, a major weakness of the existing literature on the subject. Participants included 59 chronic schizophrenia patients, and 31 first-episode schizophrenia patients. Diffusion-weighted neuroimaging was used to calculate fractional anisotropy (FA) in each major brain region (frontal, temporal, parietal, and occipital lobes). Negative symptoms were measured using the Scale for the Assessment of Negative Symptoms (SANS) in all schizophrenia patients. Significant bivariate correlations were observed between global SANS scores and global FA, as well as in most brain regions. These relationships appeared to be driven by SANS items measuring facial expressiveness, poor eye contact, affective flattening , inappropriate affect, poverty of speech, poverty of speech content, alogia, and avolition. However, upon addition of age as a covariate, the observed relationships became non-significant. Further analysis revealed very strong age effects on both FA and SANS scores in the current sample. The findings of this study refute previous reports of significant relationships between DTI variables and negative symptoms in schizophrenia, and they suggest an important confounding variable to be considered in future studies in this population. PMID:24957354

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

    PubMed

    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. PMID:27232102

  4. Effects of additional interfering signals on adaptive array performance

    NASA Technical Reports Server (NTRS)

    Moses, Randolph L.

    1989-01-01

    The effects of additional interference signals on the performance of a fully adaptive array are considered. The case where the number of interference signals exceeds the number of array degrees of freedom is addressed. It is shown how performance is affected as a function of the number of array elements, the number of interference signals, and the directivity of the array antennas. By using directive auxiliary elements, the performance of the array can be as good as the performance when the additional interference signals are not present.

  5. Additive genetic effect of APOE and BDNF on hippocampus activity.

    PubMed

    Kauppi, Karolina; Nilsson, Lars-Göran; Persson, Jonas; Nyberg, Lars

    2014-04-01

    Human memory is a highly heritable polygenic trait with complex inheritance patterns. To study the genetics of memory and memory-related diseases, hippocampal functioning has served as an intermediate phenotype. The importance of investigating gene-gene effects on complex phenotypes has been emphasized, but most imaging studies still focus on single polymorphisms. APOE ε4 and BDNF Met, two of the most studied gene variants for variability in memory performance and neuropsychiatric disorders, have both separately been related to poorer episodic memory and altered hippocampal functioning. Here, we investigated the combined effect of APOE and BDNF on hippocampal activation (N=151). No non-additive interaction effects were seen. Instead, the results revealed decreased activation in bilateral hippocampus and parahippocampus as a function of the number of APOE ε4 and BDNF Met alleles present (neither, one, or both). The combined effect was stronger than either of the individual effects, and both gene variables explained significant proportions of variance in BOLD signal change. Thus, there was an additive gene-gene effect of APOE and BDNF on medial temporal lobe (MTL) activation, showing that a larger proportion of variance in brain activation attributed to genetics can be explained by considering more than one gene variant. This effect might be relevant for the understanding of normal variability in memory function as well as memory-related disorders associated with APOE and BDNF. PMID:24321557

  6. Tin nanoparticles as an effective conductive additive in silicon anodes.

    PubMed

    Zhong, L; Beaudette, C; Guo, J; Bozhilov, K; Mangolini, L

    2016-01-01

    We have found that the addition of tin nanoparticles to a silicon-based anode provides dramatic improvements in performance in terms of both charge capacity and cycling stability. Using a simple procedure and off-the-shelf additives and precursors, we developed a structure in which the tin nanoparticles are segregated at the interface between the silicon-containing active layer and the solid electrolyte interface. Even a minor addition of tin, as small as ∼2% by weight, results in a significant decrease in the anode resistance, as confirmed by electrochemical impedance spectroscopy. This leads to a decrease in charge transfer resistance, which prevents the formation of electrically inactive "dead spots" in the anode structure and enables the effective participation of silicon in the lithiation reaction. PMID:27484849

  7. Tin nanoparticles as an effective conductive additive in silicon anodes

    PubMed Central

    Zhong, L.; Beaudette, C.; Guo, J.; Bozhilov, K.; Mangolini, L.

    2016-01-01

    We have found that the addition of tin nanoparticles to a silicon-based anode provides dramatic improvements in performance in terms of both charge capacity and cycling stability. Using a simple procedure and off-the-shelf additives and precursors, we developed a structure in which the tin nanoparticles are segregated at the interface between the silicon-containing active layer and the solid electrolyte interface. Even a minor addition of tin, as small as ∼2% by weight, results in a significant decrease in the anode resistance, as confirmed by electrochemical impedance spectroscopy. This leads to a decrease in charge transfer resistance, which prevents the formation of electrically inactive “dead spots” in the anode structure and enables the effective participation of silicon in the lithiation reaction. PMID:27484849

  8. Tin nanoparticles as an effective conductive additive in silicon anodes

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Beaudette, C.; Guo, J.; Bozhilov, K.; Mangolini, L.

    2016-08-01

    We have found that the addition of tin nanoparticles to a silicon-based anode provides dramatic improvements in performance in terms of both charge capacity and cycling stability. Using a simple procedure and off-the-shelf additives and precursors, we developed a structure in which the tin nanoparticles are segregated at the interface between the silicon-containing active layer and the solid electrolyte interface. Even a minor addition of tin, as small as ∼2% by weight, results in a significant decrease in the anode resistance, as confirmed by electrochemical impedance spectroscopy. This leads to a decrease in charge transfer resistance, which prevents the formation of electrically inactive “dead spots” in the anode structure and enables the effective participation of silicon in the lithiation reaction.

  9. Effectiveness of various organometallics as antiwear additives in mineral oil

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1977-01-01

    Sliding friction experiments were conducted with 1045 steel contacting 302 stainless steel and lubricated with various organometallics in mineral oil. Auger emission spectroscopy was used to determine the element present in the wear contact zone. The results indicate that there are organometallics which are as effective an antiwear additives as the commonly used zinc dialkyl dithiophosphate. These include dimethyl cadmium, triphenyl lead thiomethoxide, and triphenyl tin chloride. The additives were examined in concentrations to 1 weight percent. With dimethyl cadmium at concentrations of 0.5 weight percent and above, cadmium was detected in the contact zone. Coincident with the detection of cadmium, a marked decrease in the friction coefficient was observed. All additives examined reduced friction, but only the aforementioned reduced wear to a level comparable to that observed with zinc dialkyl dithiophosphate.

  10. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1989-02-04

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used will include S, P, Ag, Cu, Mn, and Na. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of studies including temperature programmed desorption, infrared study of NO adsorption, reactive probing, steady state rate measurement, and transient kinetic study. A better understanding of the role of additive may allow us to use chemical additives to manipulate the catalytic properties of Rh- and Ni-based catalysts for producing high yields of ethanol from syngas. CO insertion is known to be a key step to the formation of acetaldehyde and ethanol from CO hydrogenation over Rh catalysts. Ethylene hydroformylation has often served as a probe to determine CO insertion capabilities of Rh catalysts. The mechanism of CO insertion in ethylene hydroformylation over Rh/SiO{sub 2} was investigated.

  11. How encompassing is the effect of negativity bias on political conservatism?

    PubMed

    Malka, Ariel; Soto, Christopher J

    2014-06-01

    We argue that the political effects of negativity bias are narrower than Hibbing et al. suggest. Negativity bias reliably predicts social, but not economic, conservatism, and its political effects often vary across levels of political engagement. Thus the role of negativity bias in broad ideological conflict depends on the strategic packaging of economic and social attitudes by political elites. PMID:24970443

  12. Effect of trehalose addition on volatiles responsible for strawberry aroma.

    PubMed

    Kopjar, Mirela; Hribar, Janez; Simcic, Marjan; Zlatić, Emil; Pozrl, Tomaz; Pilizota, Vlasta

    2013-12-01

    Aroma is one of the most important quality properties of food products and has a great influence on quality and acceptability of foods. Since it is very difficult to control, in this study the effect of addition of trehalose (3, 5 and 10%) to freeze-dried strawberry cream fillings was investigated as a possible means for retention of some of the aroma compounds responsible for the strawberry aroma. In samples with added trehalose, higher amounts of fruity esters were determined. Increase of trehalose content did not cause a proportional increase in the amount of fruity esters. However, results of our research showed that trehalose addition did not have the same effect on both gamma-decalactone and furaneol. PMID:24555295

  13. Double hysteresis loops and large negative and positive electrocaloric effects in tetragonal ferroelectrics.

    PubMed

    Wu, Hong-Hui; Zhu, Jiaming; Zhang, Tong-Yi

    2015-10-01

    Phase field modelling and thermodynamic analysis are employed to investigate depolarization and compression induced large negative and positive electrocaloric effects (ECEs) in ferroelectric tetragonal crystalline nanoparticles. The results show that double-hysteresis loops of polarization versus electric field dominate at temperatures below the Curie temperature of the ferroelectric material, when the mechanical compression exceeds a critical value. In addition to the mechanism of pseudo-first-order phase transition (PFOPT), the double-hysteresis loops are also caused by the abrupt rise of macroscopic polarization from the abc phase to the c phase or the sudden fall of macroscopic polarization from the c phase to the abc phase when the temperature increases. This phenomenon is called the electric-field-induced-pseudo-phase transition (EFIPPT) in the present study. Similar to the two types of PFOPTs, the two types of EFIPPTs cause large negative and positive ECEs, respectively, and give the maximum absolute values of negative and positive adiabatic temperature change (ATC ΔT). The temperature associated with the maximum absolute value of negative ATC ΔT is lower than that associated with the maximum positive ATC ΔT. Both maximum absolute values of ATC ΔTs change with the variation in the magnitude of an applied electric field and depend greatly on the compression intensity. PMID:26307461

  14. First-principles particle simulation and Boltzmann equation analysis of negative differential conductivity and transient negative mobility effects in xenon

    NASA Astrophysics Data System (ADS)

    Donko, Zoltan; Dyatko, Nikolay

    2016-06-01

    The Negative Differential Conductivity and Transient Negative Mobility effects in xenon gas are analyzed by a first-principles particle simulation technique and via an approximate solution of the Boltzmann transport equation (BE). The particle simulation method is devoid of the approximations that are traditionally adopted in the BE solutions in which: (i) the distribution function is searched for in a two-term form; (ii) the Coulomb part of the collision integral for the anisotropic part of the distribution function is neglected; (iii) Coulomb collisions are treated as binary events; and (iv) the range of the electron-electron interaction is limited to a cutoff distance. The results obtained from the two methods are, for both effects, in good qualitative agreement, small differences are attributed to the approximations listed above.

  15. The Buffering Effects of Job Embeddedness on Negative Shocks

    ERIC Educational Resources Information Center

    Burton, James P.; Holtom, Brooks C.; Sablynski, Chris J.; Mitchell, Terence R.; Lee, Thomas W.

    2010-01-01

    Unpleasant events are a fact of organizational life. The way in which people respond to such events, however, varies. In the present study, we hypothesized and found that some individuals choose to respond to negative events in ways that helped the organization. Instead of withdrawing in an attempt to "get even" by reducing work outputs, these…

  16. Effect of Neonatal Clomipramine Treatment on Consummatory Successive Negative Contrast

    ERIC Educational Resources Information Center

    Ruetti, Eliana; Burgueno, Adriana L.; Justel, Nadia R.; Pirola, Carlos J.; Mustaca, Alba E.

    2013-01-01

    Neonatal administration of clomipramine (CLI) produces physiological, neuroendocrinal and behavioral abnormalities in rats when they reach adulthood, which are similar to those observed in animal models of depression. In consummatory successive negative contrast (cSNC), rats that have had experience drinking 32% sucrose solution drink…

  17. Neural Effects of Positive and Negative Incentives during Marijuana Withdrawal

    PubMed Central

    Filbey, Francesca M.; Dunlop, Joseph; Myers, Ursula S.

    2013-01-01

    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. PMID:23690923

  18. Neural effects of positive and negative incentives during marijuana withdrawal.

    PubMed

    Filbey, Francesca M; Dunlop, Joseph; Myers, Ursula S

    2013-01-01

    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. PMID:23690923

  19. Destructive Dialogue: Negative Self-Talk and Effective Imaging.

    ERIC Educational Resources Information Center

    Weaver, Richard L., II; Cotrell, Howard W.

    Destructive dialogue, originating from frustration and disappointment, is an intrapersonal process that always involves a person in a relationship to others and that can be defined as inner talk cast in a negative tone. It is so powerful, influential, and pervasive that it can affect all aspects of a person's life and become a self-fulfilling…

  20. Effect of additives on physicochemical properties in amorphous starch matrices.

    PubMed

    Liang, Jun; Wang, Simon; Ludescher, Richard D

    2015-03-15

    The effect of the addition of non-reducing sugars or methylcellulose on the matrix physical properties and rate of non-enzymatic browning (NBR) between exogenous glucose+lysine in a starch-based glassy matrix were studied, using the methods of luminescence and FTIR. Amorphous starch-based matrices were formulated by rapidly dehydrating potato starch gel mixed with additives at weight ratios of 7:93 (additive:starch). Data on the phosphorescence emission energy and lifetime from erythrosin B dispersed in the matrices indicated that sugars decreased starch matrix mobility in a Tg-dependent manner, except for trehalose that interacted with starch in a unique mode, while methylcellulose, the additive with the highest Tg, increased the molecular mobility. Using FTIR, we found that methylcellulose decreased the strength of hydrogen bond network and sugars enhanced the hydrogen bond strength in the order: trehalose>maltitol>sucrose. Comparing those changes with the rate of NBR between exogenous glucose+lysine, we suggest that NBR rates are primarily influenced by matrix mobility, which is modulated by the hydrogen bond network, and interactions among components. PMID:25308673

  1. Effects of discharge chamber length on the negative ion generation in volume-produced negative hydrogen ion source

    SciTech Connect

    Chung, Kyoung-Jae; Jung, Bong-Ki; An, YoungHwa; Dang, Jeong-Jeung; Hwang, Y. S.

    2014-02-15

    In a volume-produced negative hydrogen ion source, control of electron temperature is essential due to its close correlation with the generation of highly vibrationally excited hydrogen molecules in the heating region as well as the generation of negative hydrogen ions by dissociative attachment in the extraction region. In this study, geometric effects of the cylindrical discharge chamber on negative ion generation via electron temperature changes are investigated in two discharge chambers with different lengths of 7.5 cm and 11 cm. Measurements with a radio-frequency-compensated Langmuir probe show that the electron temperature in the heating region is significantly increased by reducing the length of the discharge chamber due to the reduced effective plasma size. A particle balance model which is modified to consider the effects of discharge chamber configuration on the plasma parameters explains the variation of the electron temperature with the chamber geometry and gas pressure quite well. Accordingly, H{sup −} ion density measurement with laser photo-detachment in the short chamber shows a few times increase compared to the longer one at the same heating power depending on gas pressure. However, the increase drops significantly as operating gas pressure decreases, indicating increased electron temperatures in the extraction region degrade dissociative attachment significantly especially in the low pressure regime. It is concluded that the increase of electron temperature by adjusting the discharge chamber geometry is efficient to increase H{sup −} ion production as long as low electron temperatures are maintained in the extraction region in volume-produced negative hydrogen ion sources.

  2. Effects of discharge chamber length on the negative ion generation in volume-produced negative hydrogen ion source.

    PubMed

    Chung, Kyoung-Jae; Jung, Bong-Ki; An, YoungHwa; Dang, Jeong-Jeung; Hwang, Y S

    2014-02-01

    In a volume-produced negative hydrogen ion source, control of electron temperature is essential due to its close correlation with the generation of highly vibrationally excited hydrogen molecules in the heating region as well as the generation of negative hydrogen ions by dissociative attachment in the extraction region. In this study, geometric effects of the cylindrical discharge chamber on negative ion generation via electron temperature changes are investigated in two discharge chambers with different lengths of 7.5 cm and 11 cm. Measurements with a radio-frequency-compensated Langmuir probe show that the electron temperature in the heating region is significantly increased by reducing the length of the discharge chamber due to the reduced effective plasma size. A particle balance model which is modified to consider the effects of discharge chamber configuration on the plasma parameters explains the variation of the electron temperature with the chamber geometry and gas pressure quite well. Accordingly, H(-) ion density measurement with laser photo-detachment in the short chamber shows a few times increase compared to the longer one at the same heating power depending on gas pressure. However, the increase drops significantly as operating gas pressure decreases, indicating increased electron temperatures in the extraction region degrade dissociative attachment significantly especially in the low pressure regime. It is concluded that the increase of electron temperature by adjusting the discharge chamber geometry is efficient to increase H(-) ion production as long as low electron temperatures are maintained in the extraction region in volume-produced negative hydrogen ion sources. PMID:24593559

  3. Effect of surfactant addition on removal of microbubbles using ultrasound.

    PubMed

    Kobayashi, Daisuke; Hayashida, Yoshiyuki; Sano, Kazuki; Terasaka, Koichi

    2014-08-01

    It is difficult to control the bubble in a liquid by the external operation, because the behavior of the bubble is controlled in buoyancy and flow of liquid. On the other hand, microbubbles, whose diameter is several decades μm, stably disperse in static liquid because of their small buoyancy and electrical repulsion. When an ultrasound, whose frequency was 2.4 MHz, was irradiated, the milky white microbubbles suspended solution became rapidly clear. In this study, the effects of surfactant addition on the removal of microbubbles from a liquid in an ultrasonic field were investigated. The efficiency of removal of microbubbles decreased with surfactant addition. Surfactant type influenced the size of agglomerated microbubbles, and the efficiency of removal of microbubbles changed. The surface of microbubble was modified by surfactant adsorption, and the steric inhibition influenced the removal of microbubbles. PMID:24745307

  4. Effects of acetylacetone additions on PZT thin film processing

    SciTech Connect

    Schwartz, R.W.; Assink, R.A.; Dimos, D.; Sinclair, M.B.; Boyle, T.J.; Buchheit, C.D.

    1995-02-01

    Sol-gel processing methods are frequently used for the fabrication of lead zirconate titanate (PZT) thin films for many electronic applications. Our standard approach for film fabrication utilizes lead acetate and acetic acid modified metal alkoxides of zirconium and titanium in the preparation of our precursor solutions. This report highlights some of our recent results on the effects of the addition of a second chelating ligand, acetylacetone, to this process. The authors discuss the changes in film drying behavior, densification and ceramic microstructure which accompany acetylacetone additions to the precursor solution and relate the observed variations in processing behavior to differences in chemical precursor structure induced by the acetylacetone ligand. Improvements in thin film microstructure, ferroelectric and optical properties are observed when acetylacetone is added to the precursor solution.

  5. Negative refraction induced acoustic concentrator and the effects of scattering cancellation, imaging, and mirage

    NASA Astrophysics Data System (ADS)

    Wei, Qi; Cheng, Ying; Liu, Xiao-jun

    2012-07-01

    We present a three-dimensional acoustic concentrator capable of significantly enhancing the sound intensity in the compressive region with scattering cancellation, imaging, and mirage effects. The concentrator shell is built by isotropic gradient negative-index materials, which together with an exterior host medium slab constructs a pair of complementary media. The enhancement factor, which can approach infinity by tuning the geometric parameters, is always much higher than that of a traditional concentrator made by positive-index materials with the same size. The acoustic scattering theory is applied to derive the pressure field distribution of the concentrator, which is consistent with the numerical full-wave simulations. The inherent acoustic impedance match at the interfaces of the shell as well as the inverse processes of “negative refraction—progressive curvature—negative refraction” for arbitrary sound rays can exactly cancel the scattering of the concentrator. In addition, the concentrator shell can also function as an acoustic spherical magnifying superlens, which produces a perfect image with the same shape, with bigger geometric and acoustic parameters located at a shifted position. Then some acoustic mirages are observed whereby the waves radiated from (scattered by) an object located in the center region may seem to be radiated from (scattered by) its image. Based on the mirage effect, we further propose an intriguing acoustic transformer which can transform the sound scattering pattern of one object into another object at will with arbitrary geometric, acoustic, and location parameters.

  6. Effect of negative emotions evoked by light, noise and taste on trigeminal thermal sensitivity

    PubMed Central

    2014-01-01

    Background Patients with migraine often have impaired somatosensory function and experience headache attacks triggered by exogenous stimulus, such as light, sound or taste. This study aimed to assess the influence of three controlled conditioning stimuli (visual, auditory and gustatory stimuli and combined stimuli) on affective state and thermal sensitivity in healthy human participants. Methods All participants attended four experimental sessions with visual, auditory and gustatory conditioning stimuli and combination of all stimuli, in a randomized sequence. In each session, the somatosensory sensitivity was tested in the perioral region with use of thermal stimuli with and without the conditioning stimuli. Positive and Negative Affect States (PANAS) were assessed before and after the tests. Subject based ratings of the conditioning and test stimuli in addition to skin temperature and heart rate as indicators of arousal responses were collected in real time during the tests. Results The three conditioning stimuli all induced significant increases in negative PANAS scores (paired t-test, P ≤0.016). Compared with baseline, the increases were in a near dose-dependent manner during visual and auditory conditioning stimulation. No significant effects of any single conditioning stimuli were observed on trigeminal thermal sensitivity (P ≥0.051) or arousal parameters (P ≥0.057). The effects of combined conditioning stimuli on subjective ratings (P ≤0.038) and negative affect (P = 0.011) were stronger than those of single stimuli. Conclusions All three conditioning stimuli provided a simple way to evoke a negative affective state without physical arousal or influence on trigeminal thermal sensitivity. Multisensory conditioning had stronger effects but also failed to modulate thermal sensitivity, suggesting that so-called exogenous trigger stimuli e.g. bright light, noise, unpleasant taste in patients with migraine may require a predisposed or sensitized nervous

  7. PREDATOR IDENTITY AND ADDITIVE EFFECTS IN A TREEHOLE COMMUNITY

    PubMed Central

    Griswold, Marcus W.; Lounibos, L. Philip

    2007-01-01

    Multiple predator species can interact as well as strongly affect lower trophic levels, resulting in complex, nonadditive effects on prey populations and community structure. Studies of aquatic systems have shown that interactive effects of predators on prey are not necessarily predictable from the direct effects of each species alone. To test for complex interactions, the individual and combined effects of a top and intermediate predator on larvae of native and invasive mosquito prey were examined in artificial analogues of water-filled treeholes. The combined effects of the two predators were accurately predicted from single predator treatments by a multiplicative risk model, indicating additivity. Overall survivorship of both prey species decreased greatly in the presence of the top predator Toxorhynchites rutilus. By itself, the intermediate predator Corethrella appendiculata increased survivorship of the native prey species Ochlerotatus triseriatus and decreased survivorship of the invasive prey species Aedes albopictus relative to treatments without predators. Intraguild predation did not occur until alternative prey numbers had been reduced by approximately one-half. Owing to changes in size structure accompanying its growth, T. rutilus consumed more prey as time progressed, whereas C. appendiculata consumed less. The intermediate predator, C. appendiculata, changed species composition by preferentially consuming A. albopictus, while the top predator, T. rutilus, reduced prey density, regardless of species. Although species interactions were in most cases predicted from pairwise interactions, risk reduction from predator interference occurred when C. appendiculata densities were increased and when the predators were similarly sized. PMID:16676542

  8. Galfenol alloying additions and the effects on uniaxial anisotropy generation

    NASA Astrophysics Data System (ADS)

    Summers, Eric; Meloy, Rob; Restorff, J. B.

    2009-07-01

    The effects of substitutional and interstitial additions on uniaxial anisotropy (Kuni) generated via stress annealing were investigated for the galfenol (Fe-Ga) alloy system. Polycrystalline samples prepared via free stand zone melt directional solidification technique were tested under pre- and post-stress annealed conditions in order to ascertain the extent of the built-in stress (Tbuilt-in) created. Energy based modeling utilizing magnetostriction and magnetization data was used to determine Kuni and Tbuilt-in. Differential magnetomechanical properties; d33 and μr were estimated using the same model. Carbon additions from a Fe-C master alloy resulted in Kuni and Tbuilt-in values of 12.1 kJ/m3 and 55 MPa, comparable to the binary system. Low carbon steel additions resulted in a minor decrease in Kuni to 9.6 kJ/m3, but still had high Tbuilt-in values of 54 MPa. Aluminum additions exhibited the largest decreases in Kuni and Tbuilt-in. A linear decrease in both values was observed as a function of increasing aluminum content. Kuni values for Fe81.6Ga13.8Al4.6 and Fe81.6Ga9.2Al9.2 alloys were 6.7 and 4.2 kJ/m3, respectively. Tbuilt-in values for Fe81.6Ga13.8Al4.6 and Fe81.6Ga9.2Al9.2 alloys were 37 and 24 MPa, respectively. Estimated d33 and μr values ranged from 2.0 to 2.7×10-8 m/A and 120-170 for all compositions studied.

  9. Eddy damping effect of additional conductors in superconducting levitation systems

    NASA Astrophysics Data System (ADS)

    Jiang, Zhao-Fei; Gou, Xiao-Fan

    2015-12-01

    Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  10. Effectiveness of antibacterial copper additives in silicone implants.

    PubMed

    Gosau, Martin; Bürgers, Ralf; Vollkommer, Tobias; Holzmann, Thomas; Prantl, Lukas

    2013-08-01

    Staphylococcus epidermidis plays a major role in capsular contractures of silicone breast implants. This in vitro study evaluates the antibacterial effect of copper on S. epidermidis in silicone implants. Specimens of a silicone material used for breast augmentation (Cu0) and specimens coated with different copper concentrations (Cu1, Cu2) were artificially aged. Surface roughness and surface free energy were assessed. The specimens were incubated in an S. epidermidis suspension. We assessed the quantification and the viability of adhering bacteria by live/dead cell labeling with fluorescence microscopy. Additionally, inhibition of bacterial growth was evaluated by agar diffusion, broth culture, and quantitative culture of surface bacteria. No significant differences in surface roughness and surface free energy were found between Cu0, Cu1 and Cu2. Aging did not change surface characteristics and the extent of bacterial adhesion. Fluorescence microscopy showed that the quantity of bacteria on Cu0 was significantly higher than that on Cu1 and Cu2. The ratio of dead to total adhering bacteria was significantly lower on Cu0 than on Cu1 and Cu2, and tended to be higher for Cu2 than for Cu1. Quantitative culture showed equal trends. Copper additives seem to have anti-adherence and bactericidal effects on S. epidermidis in vitro. PMID:22492200

  11. Effects of Salinity and Nutrient Addition on Mangrove Excoecaria agallocha

    PubMed Central

    Chen, Yaping; Ye, Yong

    2014-01-01

    Effects of salinity on seed germination and growth of young (1 month old) and old (2-year old) seedlings of Excoecaria agallocha were investigated. Combined effects of salinity and nutrient level were also examined on old seedlings. Seed germination was best at 0 and 5 psu salinity. 15 psu salinity significantly delayed root initiation and decreased final establishment rate. All seeds failed to establish at 25 psu salinity. Young seedlings performed best at 0 and 5 psu, but growth was stunned at 15 psu, and all seedlings died within 90 days at 25 psu. Old seedlings grew best at salinities below 5 psu and they survived the whole cultivation at 25 psu. This indicated that E. agallocha increased salt tolerance over time. Gas exchange was significantly compromised by salinities above 15 psu but evidently promoted by high nutrient. Proline accumulated considerably at high nutrient, and its contents increased from 0 to 15 psu but decreased at 25 psu salinity. Lipid peroxidation was aggravated by increasing salinity beyond 15 psu but markedly alleviated by nutrient addition. These responses indicated that E. agallocha was intolerant to high salinity but it can be greatly enhanced by nutrient addition. PMID:24691495

  12. Probing the "additive effect" in the proline and proline hydroxamic acid catalyzed asymmetric addition of nitroalkanes to cyclic enones.

    PubMed

    Hanessian, Stephen; Govindan, Subramaniyan; Warrier, Jayakumar S

    2005-11-01

    The effect of chirality and steric bulk of 2,5-disubstituted piperazines as additives in the conjugate addition of 2-nitropropane to cyclohexenone, catalyzed by l-proline, was investigated. Neither chirality nor steric bulk affects the enantioselectivity of addition, which gives 86-93% ee in the presence of achiral and chiral nonracemic 2,5-disubstituted piperazines. Proline hydroxamic acid is shown for the first time to be an effective organocatalyst in the same Michael reaction. PMID:16189834

  13. Thermal processing of EVA encapsulants and effects of formulation additives

    SciTech Connect

    Pern, F.J.; Glick, S.H.

    1996-05-01

    The authors investigated the in-situ processing temperatures and effects of various formulation additives on the formation of ultraviolet (UV) excitable chromophores, in the thermal lamination and curing of ethylene-vinyl acetate (EVA) encapsulants. A programmable, microprocessor-controlled, double-bag vacuum laminator was used to study two commercial as formulated EVA films, A9918P and 15295P, and solution-cast films of Elvaxrm (EVX) impregnated with various curing agents and antioxidants. The results show that the actual measured temperatures of EVA lagged significantly behind the programmed profiles for the heating elements and were affected by the total thermal mass loaded inside the laminator chamber. The antioxidant Naugard P{trademark}, used in the two commercial EVA formulations, greatly enhances the formation of UV-excitable, short chromophores upon curing, whereas other tested antioxidants show little effect. A new curing agent chosen specifically for the EVA formulation modification produces little or no effect on chromophore formation, no bubbling problems in the glass/EVX/glass laminates, and a gel content of {approximately}80% when cured at programmed 155{degrees}C for 4 min. Also demonstrated is the greater discoloring effect with higher concentrations of curing-generated chromophores.

  14. Effects of positive and negative delusional ideation on memory.

    PubMed

    Sugimori, Eriko; Tanno, Yoshihiko

    2010-04-01

    We investigated the relationship between levels of delusional ideation (whether positive or negative delusions) and the activation and distortion of memory by using pairs of positive and negative adjectives describing personality traits where those adjectives had similar meanings. We presented one of each pair of adjectives in the learning phase. Immediately after the learning phase in Experiment 1, we asked whether each adjective had been presented. Participants with high (positive or negative) delusional ideation were more likely to indicate that they had learned adjectives that they had not actually learned. This finding suggested that non-learned positive (or negative) adjectives that were associated with learned negative (or positive) adjectives were more likely to be activated in participants prone to positive (or negative) delusional ideation. However, in Experiment 2, two forced-choice tests were conducted immediately after the learning phase. In this context, participants, regardless of their proneness to delusional ideation, could almost always correctly distinguish what had and had not been presented, suggesting that the activation of learned items was still stronger than that for non-learned items in the immediate test. As time passed, the proportion of false alarms for positive or negative adjectives was higher in the two forced-choice tests among those with high proneness to (positive or negative) delusional ideation, suggesting that participants with delusional ideation were increasingly likely to depend on internal conditions for retrieval over time. Nous avons examiné la relation entre les niveaux d'idéation illusoire (qu'elle soit positive ou négative) et l'activation et la distorsion de la mémoire, en utilisant des paires d'adjectifs positifs et négatifs à significations similaires décrivant des traits de personnalité. Nous avons présenté un membre de chaque paire d'adjectifs lors d'une phase d'apprentissage. Dans une première exp

  15. The effect of additives and substrates on nonferrous metal electrodeposition

    NASA Astrophysics Data System (ADS)

    Zhou, Zeyang

    Electrodeposits play an important role in science and industry today. Control of the quality of electrodeposits becomes more critical. One of the major factors which can lead to better products is the ability to control the electrocrystallization process to obtain smooth, dense and coherent deposits with good mechanical and physical properties, such as corrosion resistance, ductility and less internal stress. Many parameters may play a prominent role in electrodeposition. Two of the more important parameters is the control of impurities/additives present in the solution and cathode condition. In this study, the effects of small concentrations of tin additions on the composition, structure and surface morphology of Zn-Ni alloy deposits were studied. Electrochemical impedance spectroscopy (EIS) were conducted to study the role of tin in changing the charge transfer resistance of the reaction. The results obtained were promising in elucidating some basic factors which influence Zn-Ni alloy electrocrystallization mechanisms. The effects of thermal oxidation of stainless steel cathodes used in copper electrodeposition were studied. Particular emphasis was given to the initial stages of copper nucleation and growth. The copper electrocrystallization process was strongly influenced by the temperature applied in oxidizing the stainless steel. In this research, the effects of the impurities Alsp{3+} and Crsp{3+} using two stainless steels as cathodes during Ni electrowinning from a sulfate bath were studied. The current efficiency decreased in the presence of the impurities over the concentration range studied. Certain changes in the surface morphology, internal stress, crystallographic orientation and polarization behavior were observed. The changes were different for two stainless steel substrates.

  16. Negative Treatment Effects: Is It Time for a Black Box Warning?

    ERIC Educational Resources Information Center

    Boisvert, Charles M.

    2010-01-01

    Comments on Negative effects from psychological treatments: A perspective by David Barlow. The author addresses negative treatment effects in the psychotherapy field by stating that Barlow provided a historical perspective of clinical psychology's long-standing interest in studying the positive effects of psychotherapy, and he indicated that…

  17. Evaluating the Separate and Combined Effects of Positive and Negative Reinforcement on Task Compliance

    ERIC Educational Resources Information Center

    Bouxsein, Kelly J.; Roane, Henry S.; Harper, Tara

    2011-01-01

    Positive and negative reinforcement are effective for treating escape-maintained destructive behavior. The current study evaluated the separate and combined effects of these contingencies to increase task compliance. Results showed that a combination of positive and negative reinforcement was most effective for increasing compliance. (Contains 1…

  18. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1989-04-30

    The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativeities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experimental studies of NO adsorption, reactive probing, steady state rate measurement, and transient kinetic study. CO insertion is known to be a key step to the formation of acetaldehyde and ethanol from CO hydrogenation. Reaction of ethylene with syngas is used as a probe to determine CO insertion capabilities of metal catalysts. During the sixth quarter of the project, the mechanism of CO insertion on Ni/SiO{sub 2} was investigated by in-situ infrared spectroscopy. Ni/SiO{sub 2}, a methanation catalyst, has been shown to exhibit CO insertion activity. In situ infrared studies of CO/H{sub 2} and C{sub 2}H{sub 4}/CO/H{sub 2} reactions show that the carbonylation of Ni/SiO{sub 2} to Ni(CO){sub 4} leads to an inhibition of methanation in CO hydrogenation but an enhancement of formation of propionaldehyde in C{sub 2}H{sub 4}/CO/H{sub 2} reaction. The results suggest that the sites for propionaldehyde formation is different from those for methanation.

  19. Negative Priming Effect on Organic Matter Mineralisation in NE Atlantic Slope Sediments

    PubMed Central

    Gontikaki, Evangelia; Thornton, Barry; Huvenne, Veerle A. I.; Witte, Ursula

    2013-01-01

    The priming effect (PE) is a complex phenomenon which describes a modification (acceleration or retardation) in the mineralisation rate of refractory organic matter (OM) following inputs of labile material. PEs are well-studied in terrestrial ecosystems owing to their potential importance in the evolution of soil carbon stocks but have been largely ignored in aquatic systems despite the fact that the prerequisite for their occurrence, i.e. the co-existence of labile and refractory OM, is also true for sediments. We conducted stable isotope tracer experiments in continental margin sediments from the NE Atlantic (550–950 m) to study PE occurrence and intensity in relation to labile OM input. Sediment slurries were treated with increasing quantities of the 13C-labelled diatom Thalassiosira rotula and PE was quantified after 7, 14 and 21 days. There was a stepwise effect of diatom quantity on its mineralisation although mineralisation efficiency dropped with increasing substrate amounts. The addition of diatomaceous OM yielded a negative PE (i.e. retardation of existing sediment OM mineralisation) at the end of the experiment regardless of diatom quantity. Negative PE is often the result of preferential utilisation of the newly deposited labile material by the microbial community (“preferential substrate utilization”, PSU) which is usually observed at excessive substrate additions. The fact that PSU and the associated negative PE occurred even at low substrate levels in this study could be attributed to limited amounts of OM subject to priming in our study area (∼0.2% organic carbon [OC]) which seems to be an exception among continental slopes (typically >0.5%OC). We postulate that PEs will normally be positive in continental slope sediments and that their intensity will be a direct function of sediment OC content. More experiments with varying supply of substrate targeting C-poor vs. C-rich sediments are needed to confirm these hypotheses. PMID:23840766

  20. The effect of social support derived from World of Warcraft on negative psychological symptoms.

    PubMed

    Longman, Huon; O'Connor, Erin; Obst, Patricia

    2009-10-01

    Previous research examining players of massively multiplayer online games (MMOGs) suggests that players form meaningful relationships with each other. Other research indicates that people may derive social support from online sources, and this social support has been associated with greater well-being. This study used an online survey of players (N = 206) of the MMOG World of Warcraft (WoW) to examine if social support can be derived from MMOGs and to examine its relationship with negative psychological symptoms. Players of WoW were found to derive social support from playing and a positive relationship was found between game engagement and levels of in-game social support. Higher levels of in-game social support were associated with fewer negative psychological symptoms, although this effect was not maintained after accounting for social support derived from the offline sources. Additionally, a small subsample of players (n = 21) who played for 44 to 82 hours per week (M = 63.33) was identified. These players had significantly lower levels of offline social support and higher levels of negative symptoms compared to the rest of the sample. This study provides evidence that social support can be derived from MMOGs and the associated potential to promote well-being but also highlights the potential harm from spending excessive hours playing. PMID:19817567

  1. Who benefits from treatment for executive dysfunction after brain injury? Negative effects of emotion recognition deficits.

    PubMed

    Spikman, Jacoba M; Boelen, Danielle H E; Pijnenborg, Gerdina H M; Timmerman, Marieke E; van der Naalt, Joukje; Fasotti, Luciano

    2013-01-01

    Deficits in emotion recognition, a crucial aspect of social cognition, are common after serious brain injury, as are executive deficits. Since social cognition and executive function are considered to be separate constructs, our first aim was to examine the presence of emotion recognition problems in brain injury patients with dysexecutive problems. We studied 65 brain injury patients of mixed aetiology participating in a randomised controlled trial evaluating the effects of a multifaceted treatment for executive dysfunction (Spikman, Boelen, Lamberts, Brouwer, & Fasotti, 2010 ) and 84 matched controls with a test for emotion recognition. Results showed that, in patients with acquired brain injury exhibiting executive deficits, emotion recognition deficits are also present. Male patients are more impaired than female patients, irrespective of aetiology. Our second aim was to investigate whether emotion recognition problems negatively predict the results of the treatment programme. Pre-treatment emotion recognition performance significantly predicted resumption of roles in daily life (Role Resumption List; RRL) and performance on an ecologically valid test for everyday executive functioning (Executive Secretarial Task; EST) post-treatment and, in addition, interfered negatively with treatment condition. Moreover, worse pre-treatment emotion recognition skills affect the learning of compensatory strategies for executive dysfunction negatively, whereas pre-treatment dysexecutive deficits do not. PMID:23964996

  2. Negative compatibility effect: the object-updating hypothesis revisited.

    PubMed

    Jaśkowski, Piotr

    2009-02-01

    A prime even if backward masked can affect the reaction to a subsequently presented target. According to the object-updating hypothesis, negative CE (i.e. longer reactions in the compatible than incompatible trials) occurs due to the interaction between prime and a subsequent stimulus (usually a mask or flanker). Its crucial assumption is that only new elements of the mask can affect the response. As the masks are usually composed of figures that call for both possible responses, the masks' new element calls for a response opposite to that initialized by the prime. Here an experiment is described in which the prime and target were two arrowheads pointing to left or right. Two different flankers were composed from the two heads pointing to the opposite directions. In contrast to the OU hypothesis, NCEs were different for the two flankers. This finding contradicts the OU hypothesis. PMID:19156401

  3. Hierarchical additive effects on heterosis in rice (Oryza sativa L.).

    PubMed

    Dan, Zhiwu; Hu, Jun; Zhou, Wei; Yao, Guoxin; Zhu, Renshan; Huang, Wenchao; Zhu, Yingguo

    2015-01-01

    Exploitation of heterosis in crops has contributed greatly to improvement in global food and energy production. In spite of the pervasive importance of heterosis, a complete understanding of its mechanisms has remained elusive. In this study, a small test-crossed rice population was constructed to investigate the formation mechanism of heterosis for 13 traits. The results of the relative mid-parent heterosis and modes of inheritance of all investigated traits demonstrated that additive effects were the foundation of heterosis for complex traits in a hierarchical structure, and multiplicative interactions among the component traits were the framework of heterosis in complex traits. Furthermore, new balances between unit traits and related component traits provided hybrids with the opportunity to achieve an optimal degree of heterosis for complex traits. This study dissected heterosis of both reproductive and vegetative traits from the perspective of hierarchical structure for the first time. Additive multiplicative interactions of component traits were proven to be the origin of heterosis in complex traits. Meanwhile, more attention should be paid to component traits, rather than complex traits, in the process of revealing the mechanism of heterosis. PMID:26442051

  4. Hierarchical additive effects on heterosis in rice (Oryza sativa L.)

    PubMed Central

    Dan, Zhiwu; Hu, Jun; Zhou, Wei; Yao, Guoxin; Zhu, Renshan; Huang, Wenchao; Zhu, Yingguo

    2015-01-01

    Exploitation of heterosis in crops has contributed greatly to improvement in global food and energy production. In spite of the pervasive importance of heterosis, a complete understanding of its mechanisms has remained elusive. In this study, a small test-crossed rice population was constructed to investigate the formation mechanism of heterosis for 13 traits. The results of the relative mid-parent heterosis and modes of inheritance of all investigated traits demonstrated that additive effects were the foundation of heterosis for complex traits in a hierarchical structure, and multiplicative interactions among the component traits were the framework of heterosis in complex traits. Furthermore, new balances between unit traits and related component traits provided hybrids with the opportunity to achieve an optimal degree of heterosis for complex traits. This study dissected heterosis of both reproductive and vegetative traits from the perspective of hierarchical structure for the first time. Additive multiplicative interactions of component traits were proven to be the origin of heterosis in complex traits. Meanwhile, more attention should be paid to component traits, rather than complex traits, in the process of revealing the mechanism of heterosis. PMID:26442051

  5. Effects of additives on the thermostability of chloroperoxidase.

    PubMed

    Zhi, Lifei; Jiang, Yucheng; Wang, Yingsong; Hu, Mancheng; Li, Shuni; Ma, Yingjun

    2007-01-01

    The effects of several polyhydroxy compounds (glucose, fructose, gumsugar, galactose, trehalose, dextran, xylose, PEG200, glycerin) and surfactant (dioctyl sulfosuccinate sodium salt, AOT) on the catalytic activity and thermal stability of chloroperoxidase (CPO) in aqueous systems were investigated at various temperatures. A 25% superactivity was found in AOT solutions at 25 degrees C, and it could be maintained during the 882 h. PEG200 and glycerin were proven to be the most efficient stabilizer for CPO in temperatures ranging from 25 to 60 degrees C. Trehalose is more helpful than other sugars for extended storage of CPO. These results are promising in view of industrial applications of this versatile biological catalyst. The protective mechanism of various additives on CPO was discussed. PMID:17487972

  6. Effect of adsorbent addition on floc formation and clarification.

    PubMed

    Younker, Jessica M; Walsh, Margaret E

    2016-07-01

    Adding adsorbent into the coagulation process is an emerging treatment solution for targeting hard-to-remove dissolved organic compounds from both drinking water and industrial wastewater. The impact of adding powdered activated carbon (PAC) or organoclay (OC) adsorbents with ferric chloride (FeCl3) coagulant was investigated in terms of potential changes to the coagulated flocs formed with respect to size, structure, and breakage and regrowth properties. The ability of dissolved air flotation (DAF) and sedimentation (SED) clarification processes to remove hybrid adsorbent-coagulant flocs was also evaluated through clarified water quality analysis of samples collected in bench-scale jar test experiments. The jar tests were conducted using both a synthetic fresh water and oily wastewater test water spiked with dissolved aromatic compounds phenol and naphthalene. Results of the study demonstrated that addition of adsorbent reduced the median coagulated floc size by up to 50% but did not affect floc strength or regrowth potential after application of high shear. Experimental results in fresh water demonstrated that sedimentation was more effective than DAF for clarification of both FeCl3-PAC and FeCl3-OC floc aggregates. However, experimental tests performed on the synthetic oily wastewater showed that coagulant-adsorbent floc aggregates were effectively removed with both DAF and sedimentation treatment, with lower residual turbidity achieved in clarified water samples than with coagulation treatment alone. Addition of OC or PAC into the coagulation process resulted in removals of over half, or nearly all of the dissolved aromatics, respectively. PMID:27064206

  7. Constant-Pressure Combustion Charts Including Effects of Diluent Addition

    NASA Technical Reports Server (NTRS)

    Turner, L Richard; Bogart, Donald

    1949-01-01

    Charts are presented for the calculation of (a) the final temperatures and the temperature changes involved in constant-pressure combustion processes of air and in products of combustion of air and hydrocarbon fuels, and (b) the quantity of hydrocarbon fuels required in order to attain a specified combustion temperature when water, alcohol, water-alcohol mixtures, liquid ammonia, liquid carbon dioxide, liquid nitrogen, liquid oxygen, or their mixtures are added to air as diluents or refrigerants. The ideal combustion process and combustion with incomplete heat release from the primary fuel and from combustible diluents are considered. The effect of preheating the mixture of air and diluents and the effect of an initial water-vapor content in the combustion air on the required fuel quantity are also included. The charts are applicable only to processes in which the final mixture is leaner than stoichiometric and at temperatures where dissociation is unimportant. A chart is also included to permit the calculation of the stoichiometric ratio of hydrocarbon fuel to air with diluent addition. The use of the charts is illustrated by numerical examples.

  8. Interactive effects between N addition and disturbance on boreal forest ecosystem structure and function

    NASA Astrophysics Data System (ADS)

    Nordin, Annika; Strengbom, Joachim; From, Fredrik

    2014-05-01

    In management of boreal forests, nitrogen (N) enrichment from atmospheric deposition or from forest fertilization can appear in combination with land-use related disturbances, i.e. tree harvesting by clear-felling. Long-term interactive effects between N enrichment and disturbance on boreal forest ecosystem structure and function are, however, poorly known. We investigated effects of N enrichment by forest fertilization done > 25 years ago on forest understory species composition in old-growth (undisturbed) forests, and in forests clear-felled 10 years ago (disturbed). In clear-felled forests we also investigated effects of the previous N addition on growth of tree saplings. The results show that the N enrichment effect on the understory species composition was strongly dependent on the disturbance caused by clear-felling. In undisturbed forests, there were small or no effects on understory species composition from N addition. In contrast, effects were large in forests first exposed to N addition and subsequently disturbed by clear-felling. Effects of N addition differed among functional groups of plants. Abundance of graminoids increased (+232%) and abundance of dwarf shrubs decreased (-44%) following disturbance in N fertilized forests. For vascular plants, the two perturbations had contrasting effects on α-(within forests) and β-diversity (among forests): in disturbed forests, N addition reduced, or had no effect on α-diversity, while β-diversity increased. For bryophytes, negative effects of disturbance on α-diversity were smaller in N fertilized forests than in forests not fertilized, while neither N addition nor disturbance had any effects on β-diversity. Moreover, sapling growth in forests clear-felled 10 years ago was significantly higher in previously N fertilized forests than in forests not fertilized. Our study show that effects of N addition on plant communities may appear small, short-lived, or even absent until exposed to a disturbance. This

  9. The Effect of Negative Polarity Items on Inference Verification

    PubMed Central

    SZABOLCSI, ANNA; BOTT, LEWIS; McELREE, BRIAN

    2010-01-01

    The scalar approach to negative polarity item (NPI) licensing assumes that NPIs are allowable in contexts in which the introduction of the NPI leads to proposition strengthening (e.g. Kadmon & Landman 1993; Krifka 1995; Lahiri 1997; Chierchia 2006). A straightforward processing prediction from such a theory is that NPIs facilitate inference verification from sets to subsets. Three experiments are reported that test this proposal. In each experiment, participants evaluated whether inferences from sets to subsets were valid. Crucially, we manipulated whether the premises contained an NPI. In Experiment 1, participants completed a metalinguistic reasoning task and Experiments 2 and 3 tested reading times using a self-paced reading task. Contrary to expectations, no facilitation was observed when the NPI was present in the premise compared to when it was absent. In fact, the NPI significantly slowed down reading times in the inference region. Our results therefore favour those scalar theories that predict that the NPI is costly to process (Chierchia 2006), or other, non-scalar theories (Ladusaw 1992; Giannakidou 1998; Szabolcsi 2004; Postal 2005) that likewise predict NPI processing cost but, unlike Chierchia (2006), expect the magnitude of the processing cost to vary with the actual pragmatics of the NPI. PMID:21562618

  10. Further Investigating Method Effects Associated with Negatively Worded Items on Self-Report Surveys

    ERIC Educational Resources Information Center

    DiStefano, Christine; Motl, Robert W.

    2006-01-01

    This article used multitrait-multimethod methodology and covariance modeling for an investigation of the presence and correlates of method effects associated with negatively worded items on the Rosenberg Self-Esteem (RSE) scale (Rosenberg, 1989) using a sample of 757 adults. Results showed that method effects associated with negative item phrasing…

  11. Longitudinal Invariance of Self-Esteem and Method Effects Associated with Negatively Worded Items.

    ERIC Educational Resources Information Center

    Motl, Robert W.; DiStefano, Christine

    2002-01-01

    Examined the longitudinal invariance of method effects associated with negatively worded items on a self-report measure of global self-esteem. Data from the National Educational Longitudinal Study for 3,950 junior high school and high school students show that the method effects associated with negatively worded items exhibit invariance across…

  12. Ivermectin plus diethylcarbamazine: an additive effect on early microfilarial clearance.

    PubMed

    Moulia-Pelat, J P; Nguyen, L N; Glaziou, P; Chanteau, S; Ottesen, E A; Cardines, R; Martin, P M; Cartel, J L

    1994-02-01

    The effects of ivermectin, diethylcarbamazine (DEC), and the combination of both drugs on levels of microfilaremia (mf) were studied in 30 male Polynesian Wuchereria bancrofti carriers. Microfilarial densities were measured 30 min (H1/2), 1 hr (H1), and 2, 4, 8, 24, and 96 hr (H2, H4, H8, H24, and H96) after supervised single doses of ivermectin plus DEC (400 micrograms/kg plus 1 mg/kg, respectively, 400 micrograms/kg plus 3 mg/kg, respectively, and 400 micrograms/kg plus 6 mg/kg, respectively), DEC (6 mg/kg) alone, and ivermectin (400 micrograms/kg and 100 micrograms/kg, respectively) alone given to six groups of five patients each. The results showed that 1) DEC alone or combined with ivermectin induced a rapid clearance of mf after drug intake; at H1/2, the number of circulating microfilariae was reduced to 16%, 8%, 28%, and 31%, respectively, of pretreatment values in the groups receiving ivermectin plus DEC (400 micrograms/kg plus 1 mg/kg, 400 micrograms/kg plus 3 mg/kg, and 400 micrograms/kg plus 6 mg/kg) and DEC (6 mg/kg) alone; 2) ivermectin alone induced a rapid increase of mf densities during the first 2 hr, followed by a sharp decrease from H4 to H96; and 3) between H8 and H96, mf clearance was almost complete with the combination of ivermectin and DEC. A comparison among groups did not show any synergistic interaction between ivermectin and DEC on the clearance of microfilaria, with the effect of each drug being additive to each another. PMID:8116814

  13. Reversing the affordance effect: negative stimulus-response compatibility observed with images of graspable objects.

    PubMed

    Kostov, Kiril; Janyan, Armina

    2015-09-01

    Responses are faster when the task-irrelevant orientation of a graspable object's handle corresponds to the location of the response hand. Over the past decade, research has focused on dissociating between two competing accounts of this effect: One rooted in motoric object affordances and the other resting on attentional mechanisms (i.e., Simon effect). Following this avenue of inquiry, we conducted three experiments, in which subjects had to respond bimanually to grayscale photographs of frying pans and saucepans. In addition to horizontal orientation (control/leftward/rightward handles), Experiments 1 and 2 also manipulated the direction of exogenous attentional shifts (left/right) using laterally placed, colored markers within the objects. Both experiments yielded regular Simon effects based on the location of the colored markers. However, in stark contrast to previous research, a negative stimulus-response compatibility effect was obtained with regard to the orientation of the graspable handles. This reversed affordance effect was also observed using the original, unedited grayscale photographs (Experiment 3), which suggested that its occurrence cannot be attributed to the use of colored markers. These unexpected findings appear to support the idea that Simon effects result from automatic and exogenous attentional orienting mechanisms, whereas affordances arise from controlled and endogenous attentional processes. Such a top-down attentional account of affordance can accommodate the observed reversal of the effect in the context of task characteristics. PMID:26233530

  14. Lubricant and additive effects on spur gear fatigue life

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.; Scibbe, H. W.

    1985-01-01

    Spur gear endurance tests were conducted with six lubricants using a single lot of consumable-electrode vacuum melted (CVM) AISI 9310 spur gears. The sixth lubricant was divided into four batches each of which had a different additive content. Lubricants tested with a phosphorus-type load carrying additive showed a statistically significant improvement in life over lubricants without this type of additive. The presence of sulfur type antiwear additives in the lubricant did not appear to affect the surface fatigue life of the gears. No statistical difference in life was produced with those lubricants of different base stocks but with similar viscosity, pressure-viscosity coefficients and antiwear additives. Gears tested with a 0.1 wt % sulfur and 0.1 wt % phosphorus EP additives in the lubricant had reactive films that were 200 to 400 (0.8 to 1.6 microns) thick.

  15. "STOP Regain": Are There Negative Effects of Daily Weighing?

    ERIC Educational Resources Information Center

    Wing, Rena R.; Tate, Deborah F.; Gorin, Amy A.; Raynor, Hollie A.; Fava, Joseph L.; Machan, Jason

    2007-01-01

    Several recent studies suggest that daily weighing is important for long-term weight control, but concerns have been raised about possible adverse psychological effects. The "STOP Regain" clinical trial provides a unique opportunity to examine this issue both cross-sectionally and prospectively. Successful weight losers (N = 314) were randomly…

  16. The effects of positive and negative social exchanges on aging adults.

    PubMed

    Ingersoll-Dayton, B; Morgan, D; Antonucci, T

    1997-07-01

    This study tested various models of the effects of positive and negative exchanges on positive and negative affect using structural equation modeling. Based on a probability sample of middle-aged and older adults, the relationships between social exchanges and psychological well-being were examined both within the total sample and within subgroups of individuals who had experienced few vs many life events. Within the general population, the Domain Specific Model resulted in the best fit. That is, positive exchanges were associated with positive affect, and negative exchanges were associated with negative affect. However, among the subgroup that had experienced more life events, there was a significantly stronger relationship between negative exchanges and negative affect. These findings suggest that, to understand the effects of social exchanges, it is important to consider the context of life events. PMID:9224447

  17. Ants have a negative rather than a positive effect on extrafloral nectaried Crotalaria pallida performance

    NASA Astrophysics Data System (ADS)

    Pereira, Marcela Fernandes; Trigo, José Roberto

    2013-08-01

    Crotalaria pallida (Fabaceae) is a pantropical plant with extrafloral nectaries (EFNs) near the reproductive structures. EFN-visiting ants attack and remove arctiid moth Utetheisa ornatrix larvae, the main pre-dispersal seed predator, but the impact of ants on C. pallida fitness is unknown. To assess this impact, we controlled ant presence on plants and evaluated the reproductive output of C. pallida with and without ants. Predatory wasps also visit EFNs, prey upon U. ornatrix larvae, and may be driven out by ants during EFN feeding. Does this agonistic interaction affect the multitrophic interaction outcome? We found it difficult to evaluate the effect of both visitors because cages excluding wasps affect plant growth and do not allow U. ornatrix oviposition. Therefore, we verified whether ant presence inhibited wasp EFN visitation and predicted that (1) if ants confer a benefit for C. pallida, any negative effect of ants on wasps would be negligible for the plant because ants would be the best guardians, and (2) if ants are poor guardians, they would negatively affect wasps and negatively impact the fitness of C. pallida. Surprisingly, we found that the number of seeds/pods significantly increased, ca. 4.7 times, after ant removal. Additionally, we unexpectedly verified that controls showed a higher percentage of herbivore bored pods than ant-excluded plants. We found that wasps spent less time visiting EFNs patrolled by ants (ca. 299 s less). These results support our second prediction and suggest that the outcome of multitrophic interactions may vary with natural enemy actors.

  18. The Role of Negative Statements on the Subjective Effects of Traffic Noise

    NASA Astrophysics Data System (ADS)

    Nieves Vera, M.; Vila, J.; Godoy, J. F.

    1995-12-01

    This study assesses subjective effects of traffic noise and the mediator role that negative statements about the noise and about oneself play. Eighty-four students underwent two 15-minute presentations of high intensity traffic noise, with and without negative statements. The potential effect of the negative statements was enhanced by the use of instructions concerning the expectation of negative noise effects and the credibility of the statements in half the subjects. Level of anxiety, subjective noise aversion and time estimation of the noise were taken. The State Anxiety Inventory and the Profile of Mood States Questionnaire were used as pre- and post-tests. Noise increased anxiety levels, these levels being higher during the Statements condition than during the Noise alone condition. Instructions further increased the effects of these negative statements. Subjects did not adapt to noise. Scores in the questionnaires were significantly higher in the post-test than in the pre-test. Implications of these results are discussed.

  19. Aperture Size Effect on Extracted Negative Ion Current Density

    NASA Astrophysics Data System (ADS)

    de Esch, H. P. L.; Svensson, L.; Riz, D.

    2009-03-01

    This paper discusses experimental results obtained at the 1 MV testbed at CEA Cadarache that appear to show a higher extracted D- current density from small apertures. Plasma grids with different shapes have been installed and tested. All grids had one single aperture. The tests were done in volume operation and in caesium operation. We tested four grids, two with O/14 mm, one with O/11 mm and one with O/8 mm apertures. No aperture size effect was observed in volume operation. In caesiated operation the extracted current density for the O/8 mm aperture appears to be significantly higher (˜50%) than for the O/14 mm aperture. Simulations with a 3D Monte Carlo Trajectory Following Code have shown an aperture size effect of about 20%. Finally, as byproducts of the experiments, data on backstreaming positive ions and the temperature of the plasma grid have been obtained.

  20. Attentional capture by evaluative stimuli: gain- and loss-connoting colors boost the additional-singleton effect.

    PubMed

    Wentura, Dirk; Müller, Philipp; Rothermund, Klaus

    2014-06-01

    In a valence induction task, one color acquired positive valence by indicating the chance to win money (in the case of fast and correct responses), and a different color acquired negative valence by indicating the danger to lose money (in the case of slow or incorrect responses). In the additional-singleton trials of a visual search task, the task-irrelevant singleton color was either the positive one, the negative one, or one of two neutral colors. We found an additional-singleton effect (i.e., longer RTs with a singleton color than in the no-singleton control condition). This effect was significantly increased for the two valent colors (with no differences between them) relative to the two neutral colors (with no differences between them, either). This result favors the hypothesis that the general relevance of stimuli elicits attentional capture, rather than the negativity bias hypothesis. PMID:24488806

  1. Effect of fast positive ions incident on caesiated plasma grid of negative ion source

    SciTech Connect

    Bacal, M.

    2012-02-15

    This paper describes the effect on negative ion formation on a caesiated surface of the backscattering of positive ions approaching it with energy of a few tens of eV. For a positive ion energy of 45 eV, the surface produced negative ion current density due to these fast positive ions is 12 times larger than that due to thermal atoms, thus dominating the negative ion surface production instead of the thermal atoms, as considered until now.

  2. Chemistry of Food Additives: Direct and Indirect Effects.

    ERIC Educational Resources Information Center

    Pauli, George H.

    1984-01-01

    The primary component(s), impurities, and degradation products of polysorbate 80, nitrate and nitrite salts, and diethylpyrocarbonate (DEPC) are discussed. Safety considerations related to these food additives are also noted. The chick-edema factor which results from an additive in poultry feed is also discussed. (JN)

  3. A reliable method for avoiding false negative results with Luminex single antigen beads; evidence of the prozone effect.

    PubMed

    Carey, B Sean; Boswijk, Kim; Mabrok, Mazen; Rowe, Peter A; Connor, Andrew; Saif, Imran; Poles, Anthony

    2016-07-01

    Luminex single antigen bead (SAB) assays have become an essential tool in monitoring the status of antibody to the Human Leucocyte Antigen (HLA) of patients both before and after transplantation. In addition SAB data is used to aid risk stratification to assess immunological risk of humoral rejection in solid organ transplantation (CTAG/BTAG guidelines) [1]. Increasingly laboratories are reporting false negative results at high antibody titre due to a prozone effect. Here we report a case study where the prozone effect led to a false negative antibody result that could have resulted in adverse outcome. We describe a method to reliably remove the prozone effect through heat inactivation and the addition of Ethylenediaminetetraacetic acid (EDTA) to the Luminex wash buffer. PMID:27109036

  4. Negative inotropic and hypotensive effects of the superoxide dismutase mimetic tempol in pigs.

    PubMed

    Kristensen, Mads Nyboe; Frederiksen, Christian Alcaraz; Sivén, Eleonora; Hyldebrandt, Janus Adler; Juhl-Olsen, Peter; Sloth, Erik; Simonsen, Ulf; Buus, Niels Henrik

    2014-05-15

    Through interference with free radicals, the nitroxide tempol potentially increases bioavailability of nitric oxide (NO) and along with modulation of potassium channels reduces blood pressure (BP). We studied whether tempol in pigs lowers BP by mechanisms sensitive to inhibition of NO synthase or large conductance calcium-activated potassium channels (BKCa). The cardiovascular effects of intravenous tempol (25-50mg/kg) were examined in anesthetized pigs with myocardial function being evaluated by echocardiography. While saline-treated animals remained hemodynamically stable, tempol induced fast, dose-dependent and transient reductions in BP lasting 5-10 min with a simultaneous impairment of left ventricular contraction. Pretreatment with the NO synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME, 4 mg/kg) or a blocker of BKCa (tetraethylammonium (TEA), 100mg/h) increased baseline BP but also enhanced BP reductions to tempol. Isolated myocardial trabeculae subjected to an identical protocol also demonstrated dose-related reductions in contractility to tempol. This effect was not affected by l-NAME, but attenuated by TEA. In isolated mesenteric resistance arteries contracted with noradrenaline, tempol caused small postjunctional l-NAME sensitive relaxations, while neurogenic contractions were inhibited by tempol by TEA-sensitive mechanisms and mechanisms insensitive to TEA and l-NAME. In conclusion intravenous tempol induces fast transient reductions in BP associated with simultaneous reductions in myocardial contraction. Tempol exerts direct negative inotropic effects which are partly sensitive to BKCa-blockade but independent of NOS inhibition. In addition tempol has direct vasodilatory effects despite NOS and potassium channel blockade. The negative inotropic and hypotensive effects raise concerns using tempol, or structurally similar drugs, for intravenous use. PMID:24632458

  5. Top predators negate the effect of mesopredators on prey physiology.

    PubMed

    Palacios, Maria M; Killen, Shaun S; Nadler, Lauren E; White, James R; McCormick, Mark I

    2016-07-01

    Predation theory and empirical evidence suggest that top predators benefit the survival of resource prey through the suppression of mesopredators. However, whether such behavioural suppression can also affect the physiology of resource prey has yet to be examined. Using a three-tier reef fish food web and intermittent-flow respirometry, our study examined changes in the metabolic rate of resource prey exposed to combinations of mesopredator and top predator cues. Under experimental conditions, the mesopredator (dottyback, Pseudochromis fuscus) continuously foraged and attacked resource prey (juveniles of the damselfish Pomacentrus amboinensis) triggering an increase in prey O2 uptake by 38 ± 12·9% (mean ± SE). The visual stimulus of a top predator (coral trout, Plectropomus leopardus) restricted the foraging activity of the mesopredator, indirectly allowing resource prey to minimize stress and maintain routine O2 uptake. Although not as strong as the effect of the top predator, the sight of a large non-predator species (thicklip wrasse, Hemigymnus melapterus) also reduced the impact of the mesopredator on prey metabolic rate. We conclude that lower trophic-level species can benefit physiologically from the presence of top predators through the behavioural suppression that top predators impose on mesopredators. By minimizing the energy spent on mesopredator avoidance and the associated stress response to mesopredator attacks, prey may be able to invest more energy in foraging and growth, highlighting the importance of the indirect, non-consumptive effects of top predators in marine food webs. PMID:27113316

  6. On negative higher-order Kerr effect and filamentation

    NASA Astrophysics Data System (ADS)

    Loriot, V.; Béjot, P.; Ettoumi, W.; Petit, Y.; Kasparian, J.; Henin, S.; Hertz, E.; Lavorel, B.; Faucher, O.; Wolf, J.-P.

    2011-07-01

    As a contribution to the ongoing controversy about the role of higher-order Kerr effect (HOKE) in laser filamentation, we first provide thorough details about the protocol that has been employed to infer the HOKE indices from the experiment. Next, we discuss potential sources of artifact in the experimental measurements of these terms and show that neither the value of the observed birefringence, nor its inversion, nor the intensity at which it is observed, appear to be flawed. Furthermore, we argue that, independently on our values, the principle of including HOKE is straightforward. Due to the different temporal and spectral dynamics, the respective efficiency of defocusing by the plasma and by the HOKE is expected to depend substantially on both incident wavelength and pulse duration. The discussion should therefore focus on defining the conditions where each filamentation regime dominates.

  7. Effect of Art Production on Negative Mood and Anxiety for Adults in Treatment for Substance Abuse

    ERIC Educational Resources Information Center

    Laurer, Mattye; van der Vennet, Renée

    2015-01-01

    This study investigated whether art production or viewing and sorting art reproductions would be more effective in reducing negative mood and anxiety for 28 adults with substance use disorders. Participants were randomly assigned to one of two groups and completed pre- and posttest measures of negative mood and anxiety The hypothesis that art…

  8. Emotion-Specific Priming: Congruence Effects on Affect and Recognition across Negative Emotions.

    ERIC Educational Resources Information Center

    Hansen, Christine H.; Shantz, Cynthia A.

    1995-01-01

    Demonstrated the emotion-specific priming effects of negatively valenced emotions (anger, sadness, and fear) in a divided attention task. Results indicated that a negative emotion displayed by a target that matched the emotion induced by a priming manipulation was significantly stronger than an incongruous priming manipulation and displayed…

  9. The effect of switchable water additives on clay settling.

    PubMed

    Chen, Chien-Shun; Lau, Ying Yin; Mercer, Sean M; Robert, Tobias; Horton, J Hugh; Jessop, Philip G

    2013-01-01

    The recycling of process water from strip mining extractions is a very relevant task both industrially and environmentally. The sedimentation of fine tailings during such processes, however, can often require long periods of time and/or the addition of flocculants which make later water recycling difficult. We propose the use of switchable water additives as reversible flocculants for clay/water suspensions. Switchable water additives are compounds such as diamines that make it possible to reversibly control the ionic strength of an aqueous solution. Addition of CO(2) to such an aqueous solution causes the ionic strength to rise dramatically, and the change is reversed upon removal of the CO(2). These additives, while in the presence of CO(2), promote the aggregation of clay tailings, reduce settling times, and greatly increase the clarity of the liberated water. The removal of CO(2) from the liberated water regenerates a low ionic strength solution that does not promote clay aggregation and settling until CO(2) is added again. Such reversible behavior would be useful in applications such as oil sands separations in which the recycled water must not promote aggregation. When added to kaolinite and montmorillonite clay suspensions, switchable water provided process waters of lower turbidity than those additives from inorganic salts or by CO(2)-treatment alone. When recollected, the switchable water supernatant was shown to be recyclable over three cycles for enhanced settling of kaolinite. PMID:22945593

  10. Effects of Water and Nitrogen Addition on Species Turnover in Temperate Grasslands in Northern China

    PubMed Central

    Xu, Zhuwen; Wan, Shiqiang; Ren, Haiyan; Han, Xingguo; Li, Mai-He; Cheng, Weixin; Jiang, Yong

    2012-01-01

    Global nitrogen (N) deposition and climate change have been identified as two of the most important causes of current plant diversity loss. However, temporal patterns of species turnover underlying diversity changes in response to changing precipitation regimes and atmospheric N deposition have received inadequate attention. We carried out a manipulation experiment in a steppe and an old-field in North China from 2005 to 2009, to test the hypothesis that water addition enhances plant species richness through increase in the rate of species gain and decrease in the rate of species loss, while N addition has opposite effects on species changes. Our results showed that water addition increased the rate of species gain in both the steppe and the old field but decreased the rates of species loss and turnover in the old field. In contrast, N addition increased the rates of species loss and turnover in the steppe but decreased the rate of species gain in the old field. The rate of species change was greater in the old field than in the steppe. Water interacted with N to affect species richness and species turnover, indicating that the impacts of N on semi-arid grasslands were largely mediated by water availability. The temporal stability of communities was negatively correlated with rates of species loss and turnover, suggesting that water addition might enhance, but N addition would reduce the compositional stability of grasslands. Experimental results support our initial hypothesis and demonstrate that water and N availabilities differed in the effects on rate of species change in the temperate grasslands, and these effects also depend on grassland types and/or land-use history. Species gain and loss together contribute to the dynamic change of species richness in semi-arid grasslands under future climate change. PMID:22768119

  11. The negative effects of poverty & food insecurity on child development.

    PubMed

    Chilton, Mariana; Chyatte, Michelle; Breaux, Jennifer

    2007-10-01

    This paper addresses the importance of the first three years of life to the developing child, examines the importance of early childhood nutrition and the detrimental effects on child health and development due to poverty and food insecurity. As development experts learn more about the importance of the first three years of life, there is growing recognition that investments in early education, maternal-child attachment and nurturance, and more creative nutrition initiatives are critical to help break the cycle of poverty. Even the slightest forms of food insecurity can affect a young child's development and learning potential. The result is the perpetuation of another generation in poverty. Conceptualizing the poorly developed child as an embodiment of injustice helps ground the two essential frameworks needed to address food insecurity and child development: the capability approach and the human rights framework. The capability approach illuminates the dynamics that exist between poverty and child development through depicting poverty as capability deprivation and hunger as failure in the system of entitlements. The human rights framework frames undernutrition and poor development of young children as intolerable for moral and legal reasons, and provides a structure through which governments and other agencies of the State and others can be held accountable for redressing such injustices. Merging the development approach with human rights can improve and shape the planning, approach, monitoring and evaluation of child development while establishing international accountability in order to enhance the potential of the world's youngest children. PMID:18032801

  12. Negative Electron Affinity Effect on the Surface of Chemical Vapor Deposited Diamond Polycrystalline Films

    NASA Technical Reports Server (NTRS)

    Krainsky, I. L.; Asnin, V. M.; Mearini, G. T.; Dayton, J. A., Jr.

    1996-01-01

    Strong negative electron affinity effects have been observed on the surface of as-grown chemical vapor deposited diamond using Secondary Electron Emission. The test samples were randomly oriented and the surface was terminated with hydrogen. The effect appears as an intensive peak in the low energy part of the spectrum of the electron energy distribution and may be described in the model of effective negative electron affinity.

  13. The negative compatibility effect with relevant masks: a case for automatic motor inhibition

    PubMed Central

    Ocampo, Brenda; Finkbeiner, Matthew

    2013-01-01

    For many years controversy has surrounded the so-called “negative compatibility effect” (NCE), a surprising phenomenon whereby responses to a target stimulus are delayed when the target is preceded by an unconscious, response-compatible prime. According to proponents of the “self-inhibition” hypothesis, the NCE occurs when a low-level self-inhibitory mechanism supresses early motor activations that are no longer supported by perceptual evidence. This account has been debated, however, by those who regard the NCE to be a stimulus-specific phenomenon that can be explained without recourse to a self-inhibitory mechanism. The present study used a novel reach-to-touch paradigm to test whether unconscious response priming would manifest as motor activation of the opposite-to-prime response (supporting mask-induced priming accounts), or motor inhibition of the primed response (supporting the notion of low-level self-inhibition). This paper presents new findings that show the emergence of positive and negative compatibility effects as they occur in stimulus processing time. In addition, evidence is provided suggesting that the NCE is not driven by the activation of the incorrect, “opposite-to-prime” response, but rather might reflect automatic motor inhibition. PMID:24265623

  14. The negative piezoelectric effect of the ferroelectric polymer poly(vinylidene fluoride).

    PubMed

    Katsouras, Ilias; Asadi, Kamal; Li, Mengyuan; van Driel, Tim B; Kjær, Kasper S; Zhao, Dong; Lenz, Thomas; Gu, Yun; Blom, Paul W M; Damjanovic, Dragan; Nielsen, Martin M; de Leeuw, Dago M

    2016-01-01

    Piezoelectricity describes interconversion between electrical charge and mechanical strain. As expected for lattice ions displaced in an electric field, the proportionality constant is positive for all piezoelectric materials. The exceptions are poly(vinylidene fluoride) (PVDF) and its copolymers with trifluoroethylene (P(VDF-TrFE)), which exhibit a negative longitudinal piezoelectric coefficient. Reported explanations exclusively consider contraction with applied electric field of either the crystalline or the amorphous part of these semi-crystalline polymers. To distinguish between these conflicting interpretations, we have performed in situ dynamic X-ray diffraction measurements on P(VDF-TrFE) capacitors. We find that the piezoelectric effect is dominated by the change in lattice constant but, surprisingly, it cannot be accounted for by the polarization-biased electrostrictive contribution of the crystalline part alone. Our quantitative analysis shows that an additional contribution is operative, which we argue is due to an electromechanical coupling between the intermixed crystalline lamellae and amorphous regions. Our findings tie the counterintuitive negative piezoelectric response of PVDF and its copolymers to the dynamics of their composite microstructure. PMID:26436342

  15. The negative piezoelectric effect of the ferroelectric polymer poly(vinylidene fluoride)

    NASA Astrophysics Data System (ADS)

    Katsouras, Ilias; Asadi, Kamal; Li, Mengyuan; van Driel, Tim B.; Kjær, Kasper S.; Zhao, Dong; Lenz, Thomas; Gu, Yun; Blom, Paul W. M.; Damjanovic, Dragan; Nielsen, Martin M.; de Leeuw, Dago M.

    2016-01-01

    Piezoelectricity describes interconversion between electrical charge and mechanical strain. As expected for lattice ions displaced in an electric field, the proportionality constant is positive for all piezoelectric materials. The exceptions are poly(vinylidene fluoride) (PVDF) and its copolymers with trifluoroethylene (P(VDF-TrFE)), which exhibit a negative longitudinal piezoelectric coefficient. Reported explanations exclusively consider contraction with applied electric field of either the crystalline or the amorphous part of these semi-crystalline polymers. To distinguish between these conflicting interpretations, we have performed in situ dynamic X-ray diffraction measurements on P(VDF-TrFE) capacitors. We find that the piezoelectric effect is dominated by the change in lattice constant but, surprisingly, it cannot be accounted for by the polarization-biased electrostrictive contribution of the crystalline part alone. Our quantitative analysis shows that an additional contribution is operative, which we argue is due to an electromechanical coupling between the intermixed crystalline lamellae and amorphous regions. Our findings tie the counterintuitive negative piezoelectric response of PVDF and its copolymers to the dynamics of their composite microstructure.

  16. Effects of Ce additions on the age hardening response of Mg–Zn alloys

    SciTech Connect

    Langelier, Brian Esmaeili, Shahrzad

    2015-03-15

    The effects of Ce additions on the precipitation hardening behaviour of Mg–Zn are examined for a series of alloys, with Ce additions at both alloying and microalloying levels. The alloys are artificially aged, and studied using hardness measurement and X-ray diffraction, as well as optical and transmission electron microscopy. It is found that the age-hardening effect is driven by the formation of fine precipitates, the number density of which is related to the Zn content of the alloy. Conversely, the Ce content is found to slightly reduce hardening. When the alloy content of Ce is high, large secondary phase particles containing both Ce and Zn are present, and remain stable during solutionizing. These particles effectively reduce the amount of Zn available as solute for precipitation, and thereby reduce hardening. Combining hardness results with thermodynamic analysis of alloy solute levels also suggests that Ce can have a negative effect on hardening when present as solutes at the onset of ageing. This effect is confirmed by designing a pre-ageing heat treatment to preferentially remove Ce solutes, which is found to restore the hardening capability of an Mg–Zn–Ce alloy to the level of the Ce-free alloy. - Highlights: • The effects of Ce additions on precipitation in Mg–Zn alloys are examined. • Additions of Ce to Mg–Zn slightly reduce the age-hardening response. • Ce-rich secondary phase particles deplete the matrix of Zn solute. • Hardening is also decreased when Ce is present in solution. • Pre-ageing to preferentially precipitate out Ce restores hardening capabilities.

  17. Negative effects of fluoranthene on the ecophysiology of tomato plants (Lycopersicon esculentum Mill) Fluoranthene mists negatively affected tomato plants.

    PubMed

    Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

    2010-02-01

    Cherry tomato plants (Lycopersicon esculentum Mill) were sprayed with fluoranthene and mixture of fluoranthene and mannitol solutions for 30d. The exposure was carried out in growth chambers in field conditions, and the air was filtered through charcoal filters to remove atmospheric contaminants. Plants were sprayed with 10microM fluoranthene as mist until they reached the fruiting stage, and the eco-physiological parameters were measured to determine the effects of the treatments. We measured CO(2) uptake and water vapour exchange, chlorophyll fluorescence, leaf pigment contents, visual symptoms and biomass allocation. Fluoranthene which was deposited as mist onto leaves negatively affected both growth and the quality of tomato plants, while other treatments did not. The photosynthetic rate measured at saturated irradiance was approximately 37% lower in fluoranthene-treated plants compared with the control group. Other variables, such as stomata conductance, the photochemical efficiency of PSII in the dark, Chl a, Chl b, and the total chlorophyll contents of the tomato leaves were significantly reduced in the fluoranthene-treated plants. Tomato plants treated with fluoranthene showed severe visible injury symptoms on the foliage during the exposure period. Mannitol (a reactive oxygen scavenger) mitigated effects of fluoranthene; thus, reactive oxygen species generated through fluoranthene may be responsible for the damaged tomato plants. It is possible for fluoranthene to decrease the aesthetic and hence the economic value of this valuable crop plant. PMID:20006894

  18. Concentration Addition, Independent Action and Generalized Concentration Addition Models for Mixture Effect Prediction of Sex Hormone Synthesis In Vitro

    PubMed Central

    Hadrup, Niels; Taxvig, Camilla; Pedersen, Mikael; Nellemann, Christine; Hass, Ulla; Vinggaard, Anne Marie

    2013-01-01

    Humans are concomitantly exposed to numerous chemicals. An infinite number of combinations and doses thereof can be imagined. For toxicological risk assessment the mathematical prediction of mixture effects, using knowledge on single chemicals, is therefore desirable. We investigated pros and cons of the concentration addition (CA), independent action (IA) and generalized concentration addition (GCA) models. First we measured effects of single chemicals and mixtures thereof on steroid synthesis in H295R cells. Then single chemical data were applied to the models; predictions of mixture effects were calculated and compared to the experimental mixture data. Mixture 1 contained environmental chemicals adjusted in ratio according to human exposure levels. Mixture 2 was a potency adjusted mixture containing five pesticides. Prediction of testosterone effects coincided with the experimental Mixture 1 data. In contrast, antagonism was observed for effects of Mixture 2 on this hormone. The mixtures contained chemicals exerting only limited maximal effects. This hampered prediction by the CA and IA models, whereas the GCA model could be used to predict a full dose response curve. Regarding effects on progesterone and estradiol, some chemicals were having stimulatory effects whereas others had inhibitory effects. The three models were not applicable in this situation and no predictions could be performed. Finally, the expected contributions of single chemicals to the mixture effects were calculated. Prochloraz was the predominant but not sole driver of the mixtures, suggesting that one chemical alone was not responsible for the mixture effects. In conclusion, the GCA model seemed to be superior to the CA and IA models for the prediction of testosterone effects. A situation with chemicals exerting opposing effects, for which the models could not be applied, was identified. In addition, the data indicate that in non-potency adjusted mixtures the effects cannot always be

  19. Catching rudeness is like catching a cold: The contagion effects of low-intensity negative behaviors.

    PubMed

    Foulk, Trevor; Woolum, Andrew; Erez, Amir

    2016-01-01

    In this article we offer a new perspective to the study of negative behavioral contagion in organizations. In 3 studies, we investigate the contagion effect of rudeness and the cognitive mechanism that explains this effect. Study 1 results show that low-intensity negative behaviors like rudeness can be contagious, and that this contagion effect can occur based on single episodes, that anybody can be a carrier, and that this contagion effect has second-order consequences for future interaction partners. In Studies 2 and 3 we explore in the laboratory the cognitive mechanism that underlies the negative behavioral contagion effect observed in Study 1. Specifically, we show that rudeness activates a semantic network of related concepts in individuals' minds, and that this activation influences individual's hostile behaviors. In sum, in these 3 studies we show that just like the common cold, common negative behaviors can spread easily and have significant consequences for people in organizations. PMID:26121091

  20. The Therapeutic Effect of Negative Pressure in Treating Femoral Head Necrosis in Rabbits

    PubMed Central

    Zhang, Yin-gang; Wang, Xuezhi; Yang, Zhi; Zhang, Hong; Liu, Miao; Qiu, Yushen; Guo, Xiong

    2013-01-01

    Because negative pressure can stimulate vascular proliferation, improve blood circulation and promote osteogenic differentiation of bone marrow stromal cells, we investigated the therapeutic effect of negative pressure on femoral head necrosis (FHN) in a rabbit model. Animals were divided into four groups (n = 60/group): [1] model control, [2] core decompression, [3] negative pressure and [4] normal control groups. Histological investigation revealed that at 4 and 8 weeks postoperatively, improvements were observed in trabecular bone shape, empty lacunae and numbers of bone marrow hematopoietic cells and fat cells in the negative pressure group compared to the core decompression group. At week 8, there were no significant differences between the negative pressure and normal control groups. Immunohistochemistry staining revealed higher expression of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) in the femoral heads in the negative pressure group compared with the core decompression group. Transmission electron microscopy revealed that cell organelles were further developed in the negative pressure group compared with the core decompression group. Microvascular ink staining revealed an increased number of bone marrow ink-stained blood vessels, a thicker vascular lumen and increased microvascular density in the negative pressure group relative to the core decompression group. Real-time polymerase chain reaction revealed that expression levels of both VEGF and BMP-2 were higher in the negative pressure group compared with the core decompression group. In summary, negative pressure has a therapeutic effect on FHN. This effect is superior to core decompression, indicating that negative pressure is a potentially valuable method for treating early FHN. PMID:23383276

  1. Negative temperament as a moderator of intervention effects in infancy: testing a differential susceptibility model.

    PubMed

    Anzman-Frasca, Stephanie; Stifter, Cynthia A; Paul, Ian M; Birch, Leann L

    2014-10-01

    A consideration of potential moderators can highlight intervention effects that are attenuated when investigating aggregate results. Differential susceptibility is one type of interaction, where susceptible individuals have poorer outcomes in negative environments and better outcomes in positive environments, compared to less susceptible individuals, who have moderate outcomes regardless of environment. In the current study, we provide rationale for investigating this type of interaction in the context of a behavioral childhood obesity preventive intervention and test whether infant negativity moderated intervention effects on infant self-regulation and weight gain and on two aspects of mothers' parenting competence: parenting self-efficacy and parenting satisfaction. Results showed that infants' negative temperament at 3 weeks moderated intervention effects on some, but not all, outcomes. The intervention led to greater parenting satisfaction in mothers with highly negative infants but did not affect parenting satisfaction in mothers with less negative infants, consistent with a model of differential susceptibility. There was also a trend toward less weight gain in highly negative intervention group infants. In contrast, there was a main effect of the intervention on infant self-regulation at 1 year, such that the intervention group had higher observed self-regulation, across levels of infant negativity. Results support the importance of incorporating tests of moderation into evaluations of obesity interventions and also illustrate that individuals may be differentially susceptible to environmental effects on some outcomes but not others. PMID:23832637

  2. Species-specific effects of pigmentation negation on the neural response to faces.

    PubMed

    Balas, Benjamin; Stevenson, Kate

    2013-08-01

    Face processing is limited in scope as a function of experience - discrimination ability and face-specific behavioral effects are reduced in out-group faces. Nonetheless, other-species faces phylogenetically close to our own may be processed by similar mechanisms as human faces. Presently, we asked whether or not the well-known effect of contrast-negation on face recognition (Galper, 1970) was exclusive to human faces or generalized to monkey faces. Negation disrupts face pigmentation substantially, allowing us to examine species-specific use of surface cues as a function of expertise. We tested adult observers behaviorally and electrophysiologically: participants completed a 4AFC discrimination task subject to manipulations of face species and independent negation of image luminance and image chroma, and the same stimuli were used to collect event-related potentials in a go/no-go task. We predicted that expertise for human faces would lead to larger deleterious effects of negation for human faces in both tasks, reflected in longer RTs for correct responses in the discrimination task and species-specific modulation of the N170 and P200 by contrast-negation. Our results however, indicate that behaviorally, luminance and chroma negation affect discrimination performance in a species-independent manner, while similar effects of contrast-negation effects are evident in each species at different components of the ERP response. PMID:23792327

  3. Effects of Atorvastatin on Negative Sign in Chronic Schizophrenia: a Double Blind Clinical Trial

    PubMed Central

    Sayyah, Mehdi; Boostani, Hatam; Ashrafpoori, Mitra; Pakseresht, Siroos

    2015-01-01

    The aim of this study was to evaluate the effects of Atorvastatin on negative symptoms in patients with chronic schizophrenia. The study was a prospective, double-blind, 6-week trial. Forty patients participated in the study; 19 patients were assigned to the Atorvastatin group as well as 21 patients to the placebo group. For assessing negative signs, we used Scale for the Assessment of Negative Symptoms (SANS) in weeks 1st, 3nd, 4th, and 6th. Moreover, patients were randomly assigned to treatment groups with Risperidone (6 mg/day) plus 20 mg Atorvastatin or with Risperidone (6 mg/day) plus placebo. Mean scores of Scale for the Assessment of Negative Symptoms (SANS) decreased during the treatment but there was no significant difference between the mean scores of two groups. The result of this trial suggested that Atorvastatin can be effective in reducing negative sign in schizophrenia although further studies seem to be needed. PMID:26664396

  4. Effect of upper airway negative pressure on inspiratory drive during sleep.

    PubMed

    Eastwood, P R; Curran, A K; Smith, C A; Dempsey, J A

    1998-03-01

    To determine the effect of upper airway (UA) negative pressure and collapse during inspiration on regulation of breathing, we studied four unanesthetized female dogs during wakefulness and sleep while they breathed via a fenestrated tracheostomy tube, which was sealed around the permanent tracheal stoma. The snout was sealed with an airtight mask, thereby isolating the UA when the fenestration (Fen) was closed and exposing the UA to intrathoracic pressure changes, but not to flow changes, when Fen was open. During tracheal occlusion with Fen closed, inspiratory time (TI) increased during wakefulness, non-rapid-eye-movement (NREM) sleep and rapid-eye-movement (REM) sleep (155 +/- 8, 164 +/- 11, and 161 +/- 32%, respectively), reflecting the removal of inhibitory lung inflation reflexes. During tracheal occlusion with Fen open (vs. Fen closed): 1) the UA remained patent; 2) TI further increased during wakefulness and NREM (215 +/- 52 and 197 +/- 28%, respectively) but nonsignificantly during REM sleep (196 +/- 42%); 3) mean rate of rise of diaphragm EMG (EMGdi/TI) and rate of fall of tracheal pressure (Ptr/TI) were decreased, reflecting an additional inhibitory input from UA receptors; and 4) both EMGdi/TI and Ptr/TI were decreased proportionately more as inspiration proceeded, suggesting greater reflex inhibition later in the effort. Similar inhibitory effects of exposing the UA to negative pressure (via an open tracheal Fen) were seen when an inspiratory resistive load was applied over several breaths during wakefulness and sleep. These inhibitory effects persisted even in the face of rising chemical stimuli. This inhibition of inspiratory motor output is alinear within an inspiration and reflects the activation of UA pressure-sensitive receptors by UA distortion, with greater distortion possibly occurring later in the effort. PMID:9480970

  5. Exercise and DHA prevent the negative effects of hypoxia on EEG and nerve conduction velocity.

    PubMed

    Erken, Haydar Ali; Erken, Gülten; Colak, Rıdvan; Genç, Osman

    2013-12-01

    It is known that hypoxia has a negative effect on nervous system functions, but exercise and DHA (docosahexaenoic acid) have positive effect. In this study, it was investigated whether exercise and/or DHA can prevent the effects of hypoxia on EEG and nerve conduction velocity (NCV). 35 adult Wistar albino male rats were divided into five groups (n=7): control (C), hypoxia (H), hypoxia and exercise (HE), hypoxia and DHA (HD), and hypoxia and exercise and DHA (HED) groups. During the 28-day hypoxia exposure, the HE and HED groups of rats were exercised (0% incline, 30 m/min speed, 20 min/day, 5 days a week). In addition, DHA (36 mg/kg/day) was given by oral gavage to rats in the HD and HED groups. While EEG records were taken before and after the experimental period, NCV records were taken after the experimental period from anesthetized rats. Data were analyzed by paired t-test, one-way ANOVA, and post hoc Tukey test. In this study, it was shown that exposure to hypoxia decreased theta activity and NCV, but exercise and DHA reduced the delta activity, while theta, alpha, beta activities, and NCV were increased. These results have shown that the effects of hypoxia exposure on EEG and NCV can be prevented by exercise and/or DHA. PMID:24377343

  6. The Positive and Negative Effects of Science Concept Tests on Student Conceptual Understanding

    NASA Astrophysics Data System (ADS)

    Chang, Chun-Yen; Yeh, Ting-Kuang; Barufaldi, James P.

    2010-01-01

    This study explored the phenomenon of testing effect during science concept assessments, including the mechanism behind it and its impact upon a learner's conceptual understanding. The participants consisted of 208 high school students, in either the 11th or 12th grade. Three types of tests (traditional multiple-choice test, correct concept test, and incorrect concept test) related to the greenhouse effect and global warming were developed to explore the mechanisms underlining the test effect. Interview data analyzed by means of the flow-map method were used to examine the two-week post-test consequences of taking one of these three tests. The results indicated: (1) Traditional tests can affect participants' long-term memory, both positively and negatively; in addition, when students ponder repeatedly and think harder about highly distracting choices during a test, they may gradually develop new conceptions; (2) Students develop more correct conceptions when more true descriptions are provided on the tests; on the other hand, students develop more misconceptions while completing tests in which more false descriptions of choices are provided. Finally, the results of this study revealed a noteworthy phenomenon that tests, if employed appropriately, may be also an effective instrument for assisting students' conceptual understanding.

  7. Effects of Video Games as Reinforcers for Computerized Addition Performance.

    ERIC Educational Resources Information Center

    Axelrod, Saul; And Others

    1987-01-01

    Four 2nd-grade students completed addition problems on a computer, using video games as reinforcers. Two variable ratio schedules of reinforcement failed to increase student accuracy or the rate of correct responses. In a no-games reinforcement condition, students had more opportunities to respond and had a greater number of correct answers.…

  8. Effects of Positive and Negative Adult-Child Interactions on Children's Social Preference

    ERIC Educational Resources Information Center

    Redd, William H.; And Others

    1975-01-01

    Studied the effects of positive and negative interaction on the performance of preschool and elementary school children and their preferences for the adults associated with each type of interaction. (Author/SDH)

  9. Reactivity to stressor pile-up in adulthood: effects on daily negative and positive affect.

    PubMed

    Schilling, Oliver K; Diehl, Manfred

    2014-03-01

    This study used data from a 30-day diary study with 289 adults (age range 18-89 years) to model the effects of stressor pile-up on individuals' daily negative affect (NA) and positive affect (PA) and to test for age differences in these effects. Specifically, we developed a new approach to operationalize and model stressor pile-up and evaluated this approach using generalized mixed models, taking into account the gamma response distribution of the highly skewed daily NA data. Findings showed that pile-up of stressors over a 1-week period was significantly coupled with increases in individuals' daily NA above and beyond the effect of concurrent stressors. Findings also showed that the effects of stressor accumulation and concurrent stress were additive rather than multiplicative. Age interacted significantly with stressor accumulation so that a higher age was associated with less NA reactivity to stressor pile-up. Yet, we did not find such an age-related association for NA reactivity to concurrent daily stressors. Daily PA was not associated with daily stress or with stressor pile-up. The operational definition of stressor pile-up presented in this study contributes to the literature by providing a new approach to model the dynamic effects of stress, and by providing new ways of separating the effects of acute stressors from the effects of stressor pile-up. The age differences found in the present study suggest that older adults develop effective emotion regulation skills for handling stressor pile-up, but that they react to acute daily stressors in a similar way than younger adults. PMID:24660797

  10. Negative mood effects on craving to smoke in women versus men.

    PubMed

    Perkins, Kenneth A; Karelitz, Joshua L; Giedgowd, Grace E; Conklin, Cynthia A

    2013-02-01

    Negative mood situations increase craving to smoke, even in the absence of any tobacco deprivation (e.g. "stressors"). Individual differences in effects of negative mood situations on craving have received relatively little attention but may include variability between men and women. Across two separate within-subjects studies, we examined sex differences in craving (via the QSU-brief) as functions of brief smoking abstinence (versus satiation; Study 1) and acute induction of negative mood (versus neutral mood; Study 2). Subjective ratings of negative affect (via the Mood Form) were also assessed. In Study 1, we compared the effects of overnight (>12h) abstinence versus non-abstinence on craving and affect in adult male (n=63) and female (n=42) smokers. In Study 2, these responses to negative versus neutral mood induction (via pictorial slides and music) were examined in male (n=85) and female (n=78) satiated smokers. Results from each study were similar in showing that craving during the abstinence and negative mood induction conditions was greater in women than men, as hypothesized, although the sex difference in craving due to abstinence was only marginal after controlling for dependence. Craving was strongly associated with negative affect in both studies. These results suggest that very acute negative mood situations (e.g. just a few minutes in Study 2), and perhaps overnight abstinence, may increase craving to smoke to a greater extent in women relative to men. PMID:22726579

  11. The effect of chemical additives on the synthesis of ethanol

    SciTech Connect

    Chuang, S.S.C.

    1992-03-06

    The objective of this research was to investigate the reaction mechanism of higher alcohol and aldehyde synthesis from syngas and the role of additives in the synthesis. An in situ IR reaction system and probe molecule technique were developed to study adsorbed species, active sites, and reaction pathway during reaction. The catalysts used for this study included silica-supported Rh, Ru, and Ni. (VC)

  12. The Effect of Tungsten Additions on Disk Alloy CH98

    NASA Technical Reports Server (NTRS)

    Gayda, John; Gabb, Timothy P.

    2003-01-01

    Gas turbine engines for future subsonic transports will probably have higher pressure ratios which will require nickelbase superalloy disks with 1300 to 1400 F temperature capability. Several advanced disk alloys are being developed to fill this need. One of these, CH98, is a promising candidate for gas turbine engines and is being studied in NASA s Advanced Subsonic Technology (AST) program. For large disks, residual stresses generated during quenching from solution heat treatments are often reduced by a stabilization heat treatment, in which the disk is heated in the range of 1500 to 1600 F for several hours followed by a static air cool and age. The reduction in residual stress levels lessens distortion during machining of disks. Previous work on CH98 has indicated that stabilization treatments will decrease creep capability, however, tungsten additions appear to improve the creep capability of stabilized and aged CH98. In this study, a systematic variation of tungsten additions to CH98 was investigated. Specifically, the 1300 F tensile, creep, and fatigue crack growth properties of stabilized CH 98 were assessed with varying levels of tungsten additions.

  13. Effect of shaddock albedo addition on the properties of frankfurters.

    PubMed

    Shan, Bing; Li, Xingmin; Pan, Teng; Zheng, Limin; Zhang, Hao; Guo, Huiyuan; Jiang, Lu; Zhen, Shaobo; Ren, Fazheng

    2015-07-01

    To explore the potential as a natural auxiliary emulsifier, shaddock albedo was added into frankfurters at six different levels: 0.0, 2.5, 5.0, 7.5, 10 and 12.5 %. The emulsion capacity (EC) of meat batters and cooking properties of frankfurters were evaluated. EC of meat batters was improved with the addition of shaddock albedo and the maximum value was reached at the 5 % albedo concentration. The addition of shaddock albedo resulted in lower cooking losses of frankfurters, with the lowest value obtained at the 7.5 % level. The presence of shaddock albedo decreased the total expressible fluid (TEF) and the proportion of fat in total expressible fluid (PF) which indicated the emulsion stability of frankfurters and the lowest values both occurred at the concentration of 7.5 %. Shaddock albedo inclusion increased the lightness and yellowness of frankfurters and decreased redness. Texture profile analysis showed increased hardness and decreased chewiness of frankfurters with the addition of shaddock albedo. Consequently, shaddock albedo could be a potential source of auxiliary emulsifier filler for emulsion-type meat products. PMID:26139927

  14. The effect of feedstock additives on FCC catalyst deactivation

    SciTech Connect

    Hughes, R.; Koon, C.L.; McGhee, B.

    1995-12-31

    Fluid catalytic cracking is a major petroleum refining process and because of this the deactivation of FCC catalysts by coke deposition has been the subject of considerable investigation during the past 50 years. Nevertheless, a lack of understanding of the fundamental understanding of processes leading to coke formation still exists. Basic studies using Zeolites have usually involved excessively high levels of coke deposits compared to normal FCC operation. The present study addresses coke formation at realistic levels of 0.5 to 1.0% w/w using a standard MAT reactor in which concentrations of 1% and 10% of various additives were added to the n-hexadecane feedstock. These additives included, quinoline, phenanthrene, benzofuran, thianaphthene and indene. The coke formed was characterised by mass spectrometry and was significantly aliphatic in nature, the amount formed increasing in the order quinoline, phenanthrene, thianaphthene, benzofuran, indene. Quinoline acts primarily as a poison, whereas the other additives tend to promote coke formation in n-hexadecane cracking.

  15. Combinatorial Effects of Lapatinib and Rapamycin in Triple-Negative Breast Cancer Cells

    PubMed Central

    Liu, Tongrui; Yacoub, Rami; Taliaferro-Smith, LaTonia D.; Sun, Shi-Yong; Graham, Tisheeka R.; Dolan, Ryan; Lobo, Christine; Tighiouart, Mourad; Yang, Lily; Adams, Amy; O'Regan, Ruth M.

    2016-01-01

    Triple-negative breast cancers, which lack estrogen receptor, progesterone receptor, and HER2/neu overexpression, account for approximately 15% of breast cancers, but occur more commonly in African Americans. The poor survival outcomes seen with triple-negative breast cancers patients are, in part, due to a lack of therapeutic targets. Epidermal growth factor receptor (EGFR) is overexpressed in 50% of triple-negative breast cancers, but EGFR inhibitors have not been effective in patients with metastatic breast cancers. However, mTOR inhibition has been shown to reverse resistance to EGFR inhibitors. We examined the combination effects of mTOR inhibition with EGFR inhibition in triple-negative breast cancer in vitro and in vivo. The combination of EGFR inhibition by using lapatinib and mTOR inhibition with rapamycin resulted in significantly greater cytotoxicity than the single agents alone and these effects were synergistic in vitro. The combination of rapamycin and lapatinib significantly decreased growth of triple-negative breast cancers in vivo compared with either agent alone. EGFR inhibition abrogated the expression of rapamycin-induced activated Akt in triple-negative breast cancer cells in vitro. The combination of EGFR and mTOR inhibition resulted in increased apoptosis in some, but not all, triple-negative cell lines, and these apoptotic effects correlated with a decrease in activated eukaryotic translation initiation factor (eIF4E). These results suggest that mTOR inhibitors could sensitize a subset of triple-negative breast cancers to EGFR inhibitors. Given the paucity of effective targeted agents in triple-negative breast cancers, these results warrant further evaluation. PMID:21690228

  16. Oxidative addition of hydrogen halides and dihalogens to Pd. Trends in reactivity and relativistic effects.

    PubMed

    de Jong, G Theodoor; Kovacs, Attila; Bickelhaupt, F Matthias

    2006-06-29

    We have theoretically studied the oxidative addition of HX and X(2) to palladium for X = F, Cl, Br, I and At, using both nonrelativistic and ZORA-relativistic density functional theory at BLYP/QZ4P. The purpose is 3-fold: (i) to obtain a set of consistent potential energy surfaces (PESs) to infer accurate trends in reactivity for simple, archetypal oxidative addition reactions; (ii) to assess how relativistic effects modify these trends along X = F, Cl, Br, I and At; and (iii) to rationalize the trends in reactivity in terms of the reactants' molecular-orbital (MO) electronic structure and the H-X and X-X bond strengths. For the latter, we provide full Dirac-Coulomb CCSD(T) benchmarks. All oxidative additions to Pd are exothermic and have a negative overall barrier, except that of HF which is approximately thermoneutral and has a positive overall barrier. The activation barriers of the HX oxidative additions decrease systematically as X descends in group 17 of the periodic table; those of X(2) first increase, from F to Cl, but then also decrease further down group 17. On the other hand, HX and X(2) show clearly opposite trends regarding the heat of reaction: that of HX becomes more exothermic and that of X(2) less exothermic as X descends in group 17. Relativistic effects can be as large as 15-20 kcal/mol but they do not change the qualitative trends. Interestingly, the influence of relativistic effects on activation barriers and heats of reaction decreases for the heavier halogens due to counteracting relativistic effects in palladium and the halogens. PMID:16789784

  17. Soliton propagation in an inhomogeneous plasma at critical density of negative ions: Effects of gyratory and thermal motions of ions

    SciTech Connect

    Malik, Hitendra K.; Kawata, Shigeo

    2007-10-15

    The effects of gyratory and thermal motions of ions on soliton propagation in an inhomogeneous plasma that contains positive ions, negative ions, and electrons are studied at a critical density of negative ions. Since at this critical negative ion density the nonlinear term of the relevant Korteweg-deVries (KdV) equation vanishes, a higher order of nonlinearity is considered by retaining higher-order perturbation terms in the expansion of dependent quantities together with the appropriate set of stretched coordinates. Under this situation, time-dependent perturbation leads to the evolution of modified KdV solitons, which are governed by a modified form of the KdV equation that has an additional term due to the density gradient present in the plasma. On the basis of the solution of this equation and obliquely applied magnetic field, the effects of gyratory and thermal motions of ions are analyzed on the soliton propagation for three cases, n{sub n0}n{sub e0}, together with n{sub n0} (n{sub e0}) as the density of negative ions (electrons). The role of the negative ions in the evolution of the modes and the solitons is also discussed. Under the limiting cases, our calculations reduce to the ones obtained by other investigators in the past. This substantiates the generality of the present analysis.

  18. Effects of negative air ions on activity of neural substrates involved in autonomic regulation in rats

    NASA Astrophysics Data System (ADS)

    Suzuki, Satoko; Yanagita, Shinya; Amemiya, Seiichiro; Kato, Yumi; Kubota, Natsuko; Ryushi, Tomoo; Kita, Ichiro

    2008-07-01

    The neural mechanism by which negative air ions (NAI) mediate the regulation of autonomic nervous system activity is still unknown. We examined the effects of NAI on physiological responses, such as blood pressure (BP), heart rate (HR), and heart rate variability (HRV) as well as neuronal activity, in the paraventricular nucleus of the hypothalamus (PVN), locus coeruleus (LC), nucleus ambiguus (NA), and nucleus of the solitary tract (NTS) with c-Fos immunohistochemistry in anesthetized, spontaneously breathing rats. In addition, we performed cervical vagotomy to reveal the afferent pathway involved in mediating the effects of NAI on autonomic regulation. NAI significantly decreased BP and HR, and increased HF power of the HRV spectrum. Significant decreases in c-Fos positive nuclei in the PVN and LC, and enhancement of c-Fos expression in the NA and NTS were induced by NAI. After vagotomy, these physiological and neuronal responses to NAI were not observed. These findings suggest that NAI can modulate autonomic regulation through inhibition of neuronal activity in PVN and LC as well as activation of NA neurons, and that these effects of NAI might be mediated via the vagus nerves.

  19. Additive effect of propofol and fentanyl precipitating cardiogenic shock

    PubMed Central

    Prabhakaran, AC Jesudoss

    2013-01-01

    The intravenous administration of propofol and fentanyl has become a common practice in a variety of clinical settings including outpatient dermatologic, cosmetic and oral surgery. The combination provides both systematic sedation and analgesia with low incidence of unwanted side effects. The cardiogenic shock is very uncommon in healthy individuals. The cardiovascular depressive effect of propofol and fentanyl has been well established, but the development of cardiogenic shock is very rare when these drugs are used together. Hence the awareness of this effect is advantageous to the patients undergoing such surgeries PMID:23960431

  20. The Alternative Omen Effect: Illusory negative correlation between the outcomes of choice options.

    PubMed

    Marciano-Romm, Déborah; Romm, Assaf; Bourgeois-Gironde, Sacha; Deouell, Leon Y

    2016-01-01

    In situations of choice between uncertain options, one might get feedback on both the outcome of the chosen option and the outcome of the unchosen option ("the alternative"). Extensive research has shown that when both outcomes are eventually revealed, the alternative's outcome influences the way people evaluate their own outcome. In a series of experiments, we examined whether the outcome of the alternative plays an additional role in the decision-making process by creating expectations regarding the outcome of the chosen option. Specifically, we hypothesized that people see a good (bad) alternative's outcome as a bad (good) sign regarding their own outcome when the two outcomes are in fact uncorrelated, a phenomenon we call the "Alternative Omen Effect" (ALOE). Subjects had to repeatedly choose between two boxes, the outcomes of which were then sequentially revealed. In Experiments 1 and 2 the alternative's outcome was presented first, and we assessed the individual's prediction of their own outcome. In Experiment 3, subjects had to predict the alternative's outcome after seeing their own. We find that even though the two outcomes were in fact uncorrelated, people tended to see a good (bad) alternative outcome as a bad (good) sign regarding their own outcome. Importantly, this illusory negative correlation affected subsequent behavior and led to irrational choices. Furthermore, the order of presentation was critical: when the outcome of the chosen option was presented first, the effect disappeared, suggesting that this illusory negative correlation is influenced by self-relevance. We discuss the possible sources of this illusory correlation as well as its implications for research on counterfactual thinking. PMID:26500191

  1. Meta-atom cluster acoustic metamaterial with broadband negative effective mass density

    SciTech Connect

    Chen, Huaijun; Zhai, Shilong; Ding, Changlin; Liu, Song; Luo, Chunrong; Zhao, Xiaopeng

    2014-02-07

    We design a resonant meta-atom cluster, via which a two-dimensional (2D) acoustic metamaterial (AM) with broadband negative effective mass density from 1560 Hz to 5580 Hz is fabricated. Experimental results confirm that there is only weak interaction among the meta-atoms in the cluster. And then the meta-atoms in the cluster independently resonate, resulting in the cluster becoming equivalent to a broadband resonance unit. Extracted effective refractive indices from reflection and transmission measurements of the 2D AM appear to be negative from 1500 Hz to 5480 Hz. The broadband negative refraction has also been demonstrated by our further experiments. We expect that this meta-atom cluster AM will significantly contribute to the design of broadband negative effective mass density AM.

  2. Effects of an additional dimension in the Young experiment

    SciTech Connect

    Barros, Allan Kardec

    2015-09-15

    The results of the Young experiment can be analyzed either by classical or Quantum Physics. The later one though leads to a more complete interpretation, based on two different patterns that appear when one works either with single or double slits. Here we show that the two patterns can be derived from a single principle, in the context of General Relativity, if one assumes an additional spatial dimension to the four known today. The found equations yield the same results as those in Quantum Mechanics.

  3. Additive effect of Lygodium venustum SW. in association with gentamicin.

    PubMed

    Morais-Braga, Maria F B; Souza, Teógenes M; Santos, Karla K A; Guedes, Gláucia M M; Andrade, Jacqueline C; Tintino, Saulo R; Sobral-Souza, Celestina E; Costa, José G M; Saraiva, Antonio A F; Coutinho, Henrique D M

    2016-08-01

    The aim of this work was to evaluate the interactions between gentamicin and the ethanol extract of the fern Lygodium venustum SW (EELV). The ethanol extract of L. venustum was obtained, the phytocompounds were identified and the EELV was assayed by the checkerboard method with gentamicin against two bacterial strains multiresistant to antibiotics. The antibiotic activity of gentamicin, when associated with the extract, was enhanced in an additive manner against both strains. The results indicated that L. venustum can be a source of secondary metabolites to be used in association with antibiotics as aminoglycosides in the antibiotic chemotherapy against resistant bacteria. PMID:26284428

  4. Influence of negative emotion on the framing effect: evidence from event-related potentials.

    PubMed

    Ma, Qingguo; Pei, Guanxiong; Wang, Kai

    2015-04-15

    The framing effect is the phenomenon in which different descriptions of an identical problem can result in different choices. The influence of negative emotions on the framing effect and its neurocognitive basis are important issues, especially in the domain of saving lives, which is essential and highly risky. In each trial of our experiment, the emotion stimulus is presented to the participants, followed by the decision-making stimulus, which comprises certain and risky options with the same expected value. Each pair of options is positively or negatively framed. The behavioral results indicate a significant interactive effect between negative emotion and frame; thus, the risk preference under the positive frame can be enhanced by negative emotions, whereas this finding is not true under the negative frame. The event-related potential analysis indicates that choosing certain options under the positive frame with negative emotion priming generates smaller P2 and P3 amplitudes and a larger N2 amplitude than with neutral emotion priming. The event-related potential findings indicate that individuals can detect risk faster and experience more conflict and increased decision difficulty if they choose certain options under the positive frame with negative priming compared with neutral priming. PMID:25714423

  5. Effects Of Radiation On Electronics-Additional References

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.

    1988-01-01

    Bibliography abstracts summarizing literature on effects of radiation on new electronic devices. This and second volume cover years 1984 and 1985. Third volume, covers 1982 and 1983 (previously published).

  6. Does individualism bring happiness? Negative effects of individualism on interpersonal relationships and happiness

    PubMed Central

    Ogihara, Yuji; Uchida, Yukiko

    2014-01-01

    We examined the negative effects of individualism in an East Asian culture. Although individualistic systems decrease interpersonal relationships through competition, individualistic values have prevailed in European American cultures. One reason is because individuals could overcome negativity by actively constructing interpersonal relationships. In contrast, people in East Asian cultures do not have such strategies to overcome the negative impact of individualistic systems, leading to decreased well-being. To test this hypothesis, we investigated the relationship between individualistic values, number of close friends, and subjective well-being (SWB). Study 1 indicated that individualistic values were negatively related with the number of close friends and SWB for Japanese college students but not for American college students. Moreover, Study 2 showed that even in an individualistic workplace in Japan, individualistic values were negatively related with the number of close friends and SWB. We discuss how cultural change toward increasing individualism might affect interpersonal relationships and well-being. PMID:24634663

  7. Obstructive Sleep Apnea, Hypertension, and Their Additive Effects on Atherosclerosis

    PubMed Central

    Damiani, Mario Francesco; Zito, Annapaola; Carratù, Pierluigi; Falcone, Vito Antonio; Bega, Elioda; Scicchitano, Pietro; Ciccone, Marco Matteo; Resta, Onofrio

    2015-01-01

    Background and Aims. It is widely accepted that obstructive sleep apnea (OSA) is independently associated with atherosclerosis. Similar to OSA, hypertension (HTN) is a condition associated with atherosclerosis. However, to date, the impact of the simultaneous presence of OSA and HTN on the risk of atherosclerosis has not been extensively studied. The aim of this study was to evaluate the consequences of the coexistence of OSA and HTN on carotid intima-media thickness (IMT) and on inflammatory markers of atherosclerosis (such as interleukin- [IL-] 6 and pentraxin- [PTX-] 3). Methods. The study design allowed us to define 4 groups: (1) controls (n = 30); (2) OSA patients without HTN (n = 30); (3) HTN patients without OSA (n = 30); (4) patients with OSA and HTN (n = 30). In the morning after portable monitoring (between 7 am and 8 am), blood samples were collected, and carotid IMT was measured. Results. Carotid IMT, IL-6, and PTX-3 in OSA normotensive patients and in non-OSA HTN subjects were significantly higher compared to control subjects; in addition, in OSA hypertensive patients they were significantly increased compared to OSA normotensive, non-OSA HTN, or control subjects. Conclusions. OSA and HTN have an additive role in the progression of carotid atherosclerosis and in blood levels of inflammatory markers for atherosclerosis, such as interleukin-6 and pentraxin-3. PMID:26697221

  8. Non-uniformity effects in the negative effective magnetic pressure instability

    NASA Astrophysics Data System (ADS)

    Kemel, K.; Brandenburg, A.; Kleeorin, N.; Rogachevskii, I.

    2013-07-01

    In direct numerical simulations of strongly stratified turbulence we have previously studied the development of large scale magnetic structures starting from a uniform background field. This is caused by an instability resulting from a negative contribution of small-scale turbulence to the effective (mean-field) magnetic pressure, and was qualitatively reproduced in mean-field simulations (MFS) where this pressure reduction was modeled as a function of the mean magnetic field normalized by the equipartition field. We now investigate the effect of mean current density on the turbulent pressure reduction. In our MFS, such currents are associated with sharp gradients of the growing structures. We find that an enhanced mean current density increases the suppression of the turbulent pressure.

  9. Opposing effects of negative emotion on amygdalar and hippocampal memory for items and associations

    PubMed Central

    Horner, Aidan J.; Hørlyck, Lone D.; Burgess, Neil

    2016-01-01

    Although negative emotion can strengthen memory of an event it can also result in memory disturbances, as in post-traumatic stress disorder (PTSD). We examined the effects of negative item content on amygdalar and hippocampal function in memory for the items themselves and for the associations between them. During fMRI, we examined encoding and retrieval of paired associates made up of all four combinations of neutral and negative images. At test, participants were cued with an image and, if recognised, had to retrieve the associated (target) image. The presence of negative images increased item memory but reduced associative memory. At encoding, subsequent item recognition correlated with amygdala activity, while subsequent associative memory correlated with hippocampal activity. Hippocampal activity was reduced by the presence of negative images, during encoding and correct associative retrieval. In contrast, amygdala activity increased for correctly retrieved negative images, even when cued by a neutral image. Our findings support a dual representation account, whereby negative emotion up-regulates the amygdala to strengthen item memory but down-regulates the hippocampus to weaken associative representations. These results have implications for the development and treatment of clinical disorders in which diminished associations between emotional stimuli and their context contribute to negative symptoms, as in PTSD. PMID:26969864

  10. Opposing effects of negative emotion on amygdalar and hippocampal memory for items and associations.

    PubMed

    Bisby, James A; Horner, Aidan J; Hørlyck, Lone D; Burgess, Neil

    2016-06-01

    Although negative emotion can strengthen memory of an event it can also result in memory disturbances, as in post-traumatic stress disorder (PTSD). We examined the effects of negative item content on amygdalar and hippocampal function in memory for the items themselves and for the associations between them. During fMRI, we examined encoding and retrieval of paired associates made up of all four combinations of neutral and negative images. At test, participants were cued with an image and, if recognised, had to retrieve the associated (target) image. The presence of negative images increased item memory but reduced associative memory. At encoding, subsequent item recognition correlated with amygdala activity, while subsequent associative memory correlated with hippocampal activity. Hippocampal activity was reduced by the presence of negative images, during encoding and correct associative retrieval. In contrast, amygdala activity increased for correctly retrieved negative images, even when cued by a neutral image. Our findings support a dual representation account, whereby negative emotion up-regulates the amygdala to strengthen item memory but down-regulates the hippocampus to weaken associative representations. These results have implications for the development and treatment of clinical disorders in which diminished associations between emotional stimuli and their context contribute to negative symptoms, as in PTSD. PMID:26969864

  11. Personality, work characteristics, and employee well-being: a longitudinal analysis of additive and moderating effects.

    PubMed

    Houkes, Inge; Janssen, Peter P M; de Jonge, Jan; Bakker, Arnold B

    2003-01-01

    This study tested the longitudinal influence of personality (measured by the characteristics growth need strength, negative affectivity [NA], and upward striving) on 3 psychological outcomes (intrinsic work motivation, emotional exhaustion, and turnover intention), using a pattern of specific relationships between work characteristics and these outcomes as a framework. The study hypotheses were tested in a multioccupational sample consisting of bank employees and teachers, using a 2-wave panel design with a 1-year time interval and structural equation modeling. NA had a cross-lagged direct and additive relationship with emotional exhaustion and also moderated the relationship between Time 1 workload and Time 2 emotional exhaustion. The authors concluded that NA may have multiple effects on emotional exhaustion that persist over time. PMID:12553527

  12. Effective face recognition using bag of features with additive kernels

    NASA Astrophysics Data System (ADS)

    Yang, Shicai; Bebis, George; Chu, Yongjie; Zhao, Lindu

    2016-01-01

    In past decades, many techniques have been used to improve face recognition performance. The most common and well-studied ways are to use the whole face image to build a subspace based on the reduction of dimensionality. Differing from methods above, we consider face recognition as an image classification problem. The face images of the same person are considered to fall into the same category. Each category and each face image could be both represented by a simple pyramid histogram. Spatial dense scale-invariant feature transform features and bag of features method are used to build categories and face representations. In an effort to make the method more efficient, a linear support vector machine solver, Pegasos, is used for the classification in the kernel space with additive kernels instead of nonlinear SVMs. Our experimental results demonstrate that the proposed method can achieve very high recognition accuracy on the ORL, YALE, and FERET databases.

  13. Fasting and other mild stresses with hormetic effects in Drosophila melanogaster can additively increase resistance to cold.

    PubMed

    Le Bourg, Éric

    2015-08-01

    Mild stresses can have various positive effects in animal models and human beings. Previous studies have shown that fasting, i.e. a short starvation period with water ad lib, increases resistance to a severe cold stress in flies (percentage of survivors 3 days after being kept at 0 °C). Only a few studies have combined two mild stresses with hormetic effects in an attempt to obtain additive effects. Fasting was combined in the same flies with either a hypergravity, cold or heat stress and resistance to cold was observed. When each mild stress had positive effects on this trait (fasting, cold, and hypergravity in males only), their combination had additive effects. However, when one of the mild stresses had no positive effect or even a negative effect (heat), combining it with fasting did not increase the positive effect of fasting or even decreased it. PMID:25864076

  14. The effectiveness of net negative carbon dioxide emissions in reversing anthropogenic climate change

    NASA Astrophysics Data System (ADS)

    Tokarska, Katarzyna B.; Zickfeld, Kirsten

    2015-09-01

    Artificial removal of CO2 from the atmosphere (also referred to as negative emissions) has been proposed as a means to restore the climate system to a desirable state, should the impacts of climate change become ‘dangerous’. Here we explore whether negative emissions are indeed effective in reversing climate change on human timescales, given the potentially counteracting effect of natural carbon sinks and the inertia of the climate system. We designed a range of CO2 emission scenarios, which follow a gradual transition to a zero-carbon energy system and entail implementation of various amounts of net-negative emissions at technologically plausible rates. These scenarios are used to force an Earth System Model of intermediate complexity. Results suggest that while it is possible to revert to a desired level of warming (e.g. 2 °C above pre-industrial) after different levels of overshoot, thermosteric sea level rise is not reversible for at least several centuries, even under assumption of large amounts of negative CO2 emissions. During the net-negative emission phase, artificial CO2 removal is opposed by CO2 outgassing from natural carbon sinks, with the efficiency of CO2 removal—here defined as the drop in atmospheric CO2 per unit negative emission—decreasing with the total amount of negative emissions.

  15. EFFECT OF POSITIVE AND NEGATIVE AFFECTIVE STIMULI AND BEVERAGE CUES ON MEASURES OF CRAVING IN NON TREATMENT-SEEKING ALCOHOLICS

    PubMed Central

    Mason, Barbara J.; Light, John M.; Escher, Tobie; Drobes, David J.

    2009-01-01

    Rationale Laboratory paradigms are useful for investigating mechanisms of human alcohol cue reactivity in a highly controlled environment. A number of studies have examined the effects of beverage exposure or negative affective stimuli on cue reactivity independently, but only a few have reported on interaction effects between beverage cue and affective stimuli, and none have evaluated the effects of positive stimuli on beverage cue reactivity. Objectives To assess independent and interactive effects of both positive and negative affective stimuli and beverage cue on psychophysiological and subjective measures of reactivity in alcohol dependence. Methods A total of 47 non treatment-seeking paid volunteers with current alcohol dependence participated in a within-subjects trial where each was exposed to a standardized set of pleasant, neutral, or unpleasant visual stimuli followed by alcohol or water cues. Psychophysiological cue reactivity measures were obtained during beverage presentation, and subjective reactivity measures were taken directly following beverage presentation. Results Mixed-effect models revealed a significant main effect of beverage and positive (but not negative) affective stimuli on subjective strength of craving, and significant main effects of both positive and negative affective stimuli on ratings of emotionality. Despite the power to detect relatively small interaction effects, no significant interactions were observed between affect and beverage conditions on any reactivity measure. A key finding of this study is that positive affective stimuli commonly associated with drinking situations can induce craving in the absence of alcohol cues. Conclusions Main effects of beverage cue replicated results from previous studies. In addition, positive affective stimuli influenced craving strength. Beverage and affective cues showed no interaction effects. PMID:18604601

  16. Additive and non-additive effects of simulated leaf and inflorescence damage on survival, growth and reproduction of the perennial herb Arabidopsis lyrata.

    PubMed

    Puentes, Adriana; Ågren, Jon

    2012-08-01

    Herbivores may damage both leaves and reproductive structures, and although such combined damage may affect plant fitness non-additively, this has received little attention. We conducted a 2-year field experiment with a factorial design to examine the effects of simulated leaf (0, 12.5, 25, or 50% of leaf area removed) and inflorescence damage (0 vs. 50% of inflorescences removed) on survival, growth and reproduction in the perennial herb Arabidopsis lyrata. Leaf and inflorescence damage negatively and independently reduced flower, fruit and seed production in the year of damage; leaf damage also reduced rosette size by the end of the first season and flower production in the second year. Leaf damage alone reduced the proportion of flowers forming a fruit and fruit production per plant the second year, but when combined with inflorescence damage no such effect was observed (significant leaf × inflorescence damage interaction). Damage to leaves (sources) caused a greater reduction in future reproduction than did simultaneous damage to leaves and inflorescences (sinks). This demonstrates that a full understanding of the effects of herbivore damage on plant fitness requires that consequences of damage to vegetative and reproductive structures are evaluated over more than 1 year and that non-additive effects are considered. PMID:22349755

  17. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    PubMed

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. PMID:26033303

  18. Evidence for Negative Effects of Elevated Intra-Abdominal Pressure on Pulmonary Mechanics and Oxidative Stress

    PubMed Central

    Davarcı, I.; Karcıoğlu, M.; Tuzcu, K.; İnanoğlu, K.; Yetim, T. D.; Motor, S.; Ulutaş, K. T.; Yüksel, R.

    2015-01-01

    Objective. To compare the effects of pneumoperitoneum on lung mechanics, end-tidal CO2 (ETCO2), arterial blood gases (ABG), and oxidative stress markers in blood and bronchoalveolar lavage fluid (BALF) during laparoscopic cholecystectomy (LC) by using lung-protective ventilation strategy. Materials and Methods. Forty-six patients undergoing LC and abdominal wall hernia (AWH) surgery were assigned into 2 groups. Measurements and blood samples were obtained before, during pneumoperitoneum, and at the end of surgery. BALF samples were obtained after anesthesia induction and at the end of surgery. Results. Peak inspiratory pressure, ETCO2, and pCO2 values at the 30th minute were significantly increased, while there was a significant decrease in dynamic lung compliance, pH, and pO2 values in LC group. In BALF samples, total oxidant status (TOS), arylesterase, paraoxonase, and malondialdehyde levels were significantly increased; the glutathione peroxidase levels were significantly decreased in LC group. The serum levels of TOS and paraoxonase were significantly higher at the end of surgery in LC group. In addition, arylesterase level in the 30th minute was increased compared to baseline. Serum paraoxonase level at the end of surgery was significantly increased when compared to AWH group. Conclusions. Our study showed negative effects of pneumoperitoneum in both lung and systemic levels despite lung-protective ventilation strategy. PMID:25685845

  19. Optimization studies of carbon additives to negative active material for the purpose of extending the life of VRLA batteries in high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Boden, D. P.; Loosemore, D. V.; Spence, M. A.; Wojcinski, T. D.

    The negative plates of lead-acid batteries subjected to partial-state-of-charge (PSOC) operation fail because of the development of an electrically inert film of lead sulfate on their surfaces. It has been found that carbon additives to the negative active material can significantly increase their cycle life in this type of operation. In this paper we show that various types of carbon, including graphite, carbon black eliminate the surface development of lead sulfate and that, in their presence, the lead sulfate becomes homogeneously distributed throughout the active material. Examination of active material by energy dispersive spectroscopy after extensive cycling shows that lead formed during charge of lead sulfate preferentially deposits on the carbon particles that have been embedded in the active material. Electrochemical studies have been carried out on a number of types of carbon additives having a wide range of properties. These included flake, expanded and synthetic graphite, isotropically graphitized carbon, carbon black and activated carbon. We have investigated their effect on the resistivity and surface areas of the negative active material and also on such electrochemical properties as active material utilization and cycle life. Most of the carbon additives increase the utilization of the active material and impressive increases in cycle life have been obtained with over 6000 capacity turnovers having been achieved. However, at this time, we have not been able to correlate either the type or the properties of the carbon with capacity or cycle life. Further work is needed in this area. The increases that have been achieved in cycle life provide evidence that the lead-acid battery is a viable low cost option for hybrid-electric vehicle use.

  20. Renormalization and additional degrees of freedom within the chiral effective theory for spin-1 resonances

    SciTech Connect

    Kampf, Karol; Novotny, Jiri; Trnka, Jaroslav

    2010-06-01

    We study in detail various aspects of the renormalization of the spin-1 resonance propagator in the effective field theory framework. First, we briefly review the formalisms for the description of spin-1 resonances in the path integral formulation with the stress on the issue of propagating degrees of freedom. Then we calculate the one-loop 1{sup --} meson self-energy within the resonance chiral theory in the chiral limit using different methods for the description of spin-1 particles, namely, the Proca field, antisymmetric tensor field, and the first-order formalisms. We discuss in detail technical aspects of the renormalization procedure which are inherent to the power-counting nonrenormalizable theory and give a formal prescription for the organization of both the counterterms and one-particle irreducible graphs. We also construct the corresponding propagators and investigate their properties. We show that the additional poles corresponding to the additional one-particle states are generated by loop corrections, some of which are negative norm ghosts or tachyons. We count the number of such additional poles and briefly discuss their physical meaning.

  1. Effect of lysine addition on growth of black iguana (Ctenosaura pectinata).

    PubMed

    Guzmán, Juan José Ortiz; Luis, Arcos-García José; Martínez, Germán D Mendoza; Pérez, Fernando Xicoténcatl Plata; Mascorro, Gisela Fuentes; Inzunza, Gabriela Ruelas

    2013-01-01

    The effects of the addition of lysine to commercial feed given to captive black iguana (Ctenosaura pectinata) were evaluated in terms of growth and feed digestibility. Twenty-eight-day-old black iguana with an initial weight of 5.5 ± 0.3 g were housed individually in cages measuring 45 × 45 × 45 cm. The experiment lasted 150 days. The ambient temperature ranged from 28 to 35°C with a relative humidity of 60 to 95%. Treatments consisted of the addition of different percentages of lysine to the feed (0.0, 0.1, 0.2, and 0.3%, dry matter [DM] base). There was a linear response (P < 0.01) in daily gain (68, 112, 118, and 151 mg/d) and daily intake (251, 289, 297, and 337 mg/d) for levels from 0 to 0.3%, respectively, as well in the growth in head size, snout-vent length, and total length. The digestibility of DM, neutral detergent fiber, and acid detergent fiber were reduced linearly (P < 0.01) as lysine levels increased. Intake and digestibility were negatively correlated (r = -0.74; P < 0.001). It is concluded that the addition of lysine to the black iguana diet in the first months of life is important to stimulate growth and intake. PMID:22628251

  2. Negative and positive testing effects in terms of item-specific and relational information.

    PubMed

    Mulligan, Neil W; Peterson, Daniel J

    2015-05-01

    Though retrieving information typically results in improved memory on a subsequent test (the testing effect), Peterson and Mulligan (2013) outlined the conditions under which retrieval practice results in poorer recall relative to restudy, a phenomenon dubbed the negative testing effect. The item-specific-relational account proposes that this occurs when retrieval disrupts interitem relational encoding despite enhancing item-specific information. Four experiments examined the negative testing effect, showing the following: (a) The basic phenomenon is replicable in free recall; (b) it extends to category-cued recall; (c) it converts to a positive testing effect when the final test is recognition, a test heavily reliant on item-specific information; (d) the negative testing effect in recall, robust in a pure list design, reverses to a positive testing effect in a mixed-list design; and (e) more generally, the present testing manipulation interacts with experimental design, such that an initially negative effect becomes positive or an initially positive effect becomes larger as the design changes from pure-list to mixed-list. The breadth of results fits well within the item-specific-relational framework and provides evidence against 2 alternative accounts. Finally, this research indicates that the testing effect shares important similarities with the generation effect and other similar memory phenomena. PMID:25181496

  3. Isotropic negative effective permeability in the visible range produced by clusters of plasmonic triangular nanoprisms

    NASA Astrophysics Data System (ADS)

    Morits, Dmitry; Simovski, Constantin

    2011-12-01

    In this paper we suggest and study a design solution of metamaterial made of raspberry-like clusters of silver triangular nanoprisms. We show that this design theoretically allows one to obtain isotropic negative effective permeability in the visible range even taking into account real dissipative losses in silver. To estimate the magnetic response of the structure two independent methods are used. The study is presented in view of prospective for isotropic doubly-negative metamaterials operating in the visible range.

  4. Effects of Disengagement Coping with HIV Risk on Unprotected Sex among HIV-Negative Gay Men in New York City

    PubMed Central

    Yi, Huso; Sandfort, Theo G. M.; Shidlo, Ariel

    2009-01-01

    Objective This study examined how disengagement coping with HIV risk mediated the association between internalized homophobia and unprotected anal intercourse (UAI) and how sexual encounters in public venues (public sex) and drug use moderated the association between disengagement coping and UAI among HIV-negative gay men. Disengagement coping included fatalistic beliefs about maintaining HIV-negative seronegative serostatus (fatalism), optimistic attitudes toward medical seriousness of HIV infection and reduced concern about HIV risk due to HAART (optimism), and negative affective states associated with sexual risk (anxiety). Design A survey was conducted among 285 HIV-negative gay men at an HIV prevention counseling program in New York City. Main Outcome Measures Sexual risk was defined as having had UAI with non-primary partners in the past six months. Results In addition to the positive association between internalized homophobia, disengagement coping, and UAI, fatalism mediated the association between internalized homophobia and UAI; and optimism mediated the association between anxiety and UAI. A significant moderation effect of public sex was found between fatalism and UAI. Conclusions The findings highlight the importance of understanding disengagement coping as it affects sexual risk practices among HIV-negative gay men in the continuing epidemic. PMID:20230094

  5. Decoupled effects (positive to negative) of nutrient enrichment on ecosystem services.

    PubMed

    Antón, Andrea; Cebrian, Just; Heck, Kenneth L; Duarte, Carlos M; Sheehan, Kate L; Miller, Mary-Elizabeth C; Foster, C Drew

    2011-04-01

    Eutrophication is a widespread phenomenon that disrupts natural ecosystems around the globe. Despite the general recognition that ecosystems provide many services and benefits to humans, little effort has been made to address how increasing anthropogenic eutrophication affects those services. We conducted a field experiment to determine the effect of nutrient enrichment on five ecological services provided by a model coastal system, a shallow seagrass community near Mobile Bay, Alabama (USA): (1) the provision of shelter for fauna; (2) the quality of food provided to first-order consumers; (3) quantity of food provision to first-order consumers and O2/CO2 exchange; (4) producer carbon and nitrogen storage, and (5) water clarity. The results showed a severe negative impact on seagrass density and biomass, which greatly reduced the structural complexity of the community and provision of shelter to fauna. Water clarity and the standing stock of producer carbon were reduced in the fertilized area in comparison with the control area. In contrast, nutrient addition did not affect in any consistent way the total quantity of food available for first-order consumers, the net exchange of O2/CO2, or the standing stock of producer nitrogen in the community. The nutritional quality of the food available for first-order consumers increased with fertilization. These results show that the impacts of nutrient enrichment on the services provided by natural systems may be disparate, ranging from negative to positive. These findings suggest that management policies for anthropogenic eutrophication will depend on the specific ecosystem service targeted. In the case of shallow seagrass beds, the loss of biogenic habitat and drastic impacts on commercially important fauna may be sufficiently alarming to warrant rigorous control of coastal eutrophication. PMID:21639061

  6. Examination of the negative alcohol-deprivation effect in the golden hamster (Mesocricetus auratus).

    PubMed

    DiBattista, D

    1991-01-01

    When ethanol-consuming animals are denied access to their ethanol solution for a period of days, there is typically a temporary but substantial increase in their ethanol consumption when the solution is returned. Golden hamsters are unusual in that they actually decrease their consumption of a 7% ethanol solution (v/v) under these circumstances. There experiments were therefore undertaken to further investigate this unusual negative alcohol-deprivation effect (ADE) in hamsters. In Experiment 1, the negative ADE was observed across a wide range of ethanol concentrations; adult male hamsters were given access to food, water, and either a 7.5, 15, or 30% (v/v) ethanol solution, and when the ethanol solution was withdrawn for seven days and then returned, ethanol consumption decreased significantly for several days and then recovered. Experiment 2 demonstrated that similar negative deprivation effects occur with glucose (15% w/v) and saccharin (0.1%) solutions, suggesting that the nutritional and pharmacological properties of ethanol do not play an important role in the negative ADE of hamsters. In Experiment 3, when hamsters with continuous access to either an ethanol, glucose, or saccharin solution were switched to an alternate-days access schedule, their intake of solutions decreased substantially, supporting the conclusion that a common mechanism accounts for the golden hamster's negative deprivation responses to ethanol solutions and to other solutions, both nutritive and nonnutritive. Hypotheses relating to the mechanism underlying negative deprivation effects are presented and discussed. PMID:1797030

  7. Suppressor Effects of Positive and Negative Religious Coping on Academic Burnout Among Korean Middle School Students.

    PubMed

    Noh, Hyunkyung; Chang, Eunbi; Jang, Yoojin; Lee, Ji Hae; Lee, Sang Min

    2016-02-01

    Statistical suppressor effects in prediction models can provide evidence of the interdependent relationship of independent variables. In this study, the suppressor effects of positive and negative religious coping on academic burnout were examined using longitudinal data. First, 388 middle school students reported their type of religion and use of positive and negative religious coping strategies. Four months later, they also reported their level of academic burnout. From structural equation modeling, significant suppressor effects were found among religious students. That is, the coefficients became larger when both positive and negative religious coping predicted academic burnout simultaneously, compared to when each religious coping predicted academic burnout alone. However, suppressor effects were not found among non-religious students. PMID:25656472

  8. Transition from positive to negative on the leadership effect of the biological particles group

    NASA Astrophysics Data System (ADS)

    Yi, Ma; Kwok Kit Yuen, Richard; Lee, Eric Wai Ming

    2016-04-01

    This paper reports the existence of the negative effect of leadership on the collective motion of biological particles and shows that the effect of leadership may transit from positive to negative with the change in the sensing capability of the particles. Simulations were conducted in many scenarios using a simple individual-based model. The results showed that leadership can accelerate the collective motion of the biological particles and play a positive role when the sensing capability of the particles is very limited. However, when the sensing capability of the particles becomes large enough, leadership may actually slow the collective motion of the biological particles. This unusual result suggests that leadership may have a negative effect on the collective motion of biological particles. Our finding provides a new insight into how effective leadership can be achieved in a biological particles group.

  9. Effects on Diagnostic Parameters After Removing Additional Synchronous Gear Meshes

    NASA Technical Reports Server (NTRS)

    Decker, Harry J.

    2003-01-01

    Gear cracks are typically difficult to diagnose with sufficient time before catastrophic damage occurs. Significant damage must be present before algorithms appear to be able to detect the damage. Frequently there are multiple gear meshes on a single shaft. Since they are all synchronous with the shaft frequency, the commonly used synchronous averaging technique is ineffective in removing other gear mesh effects. Carefully applying a filter to these extraneous gear mesh frequencies can reduce the overall vibration signal and increase the accuracy of commonly used vibration metrics. The vibration signals from three seeded fault tests were analyzed using this filtering procedure. Both the filtered and unfiltered vibration signals were then analyzed using commonly used fault detection metrics and compared. The tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 5000 revolutions per minute and torques from 184 to 228 percent of design load. The inability to detect these cracks with high confidence results from the high loading which is causing fast fracture as opposed to stable crack growth. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.

  10. Analysis of the Encoding Factors That Produce the Negative Repetition Effect

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Peterson, Daniel J.

    2014-01-01

    Perhaps the most basic finding in memory research is the repetition effect--the fact 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…

  11. Negative and Positive Testing Effects in Terms of Item-Specific and Relational Information

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Peterson, Daniel J.

    2015-01-01

    Though retrieving information typically results in improved memory on a subsequent test (the testing effect), Peterson and Mulligan (2013) outlined the conditions under which retrieval practice results in poorer recall relative to restudy, a phenomenon dubbed the "negative testing effect." The item-specific-relational account proposes…

  12. On the Control of Single-Prime Negative Priming: The Effects of Practice and Time Course

    ERIC Educational Resources Information Center

    Chao, Hsuan-Fu

    2009-01-01

    Single-prime negative priming refers to the phenomenon wherein repetition of a prime as the probe target results in delayed response. Sometimes this effect has been found to be contingent on participants' unawareness of the primes, and sometimes it has not. Further, sometimes this effect has been found to be eliminated when the prime could predict…

  13. The Primacy of Perceiving: Emotion Recognition Buffers Negative Effects of Emotional Labor

    ERIC Educational Resources Information Center

    Bechtoldt, Myriam N.; Rohrmann, Sonja; De Pater, Irene E.; Beersma, Bianca

    2011-01-01

    There is ample empirical evidence for negative effects of emotional labor (surface acting and deep acting) on workers' well-being. This study analyzed to what extent workers' ability to recognize others' emotions may buffer these effects. In a 4-week study with 85 nurses and police officers, emotion recognition moderated the relationship between…

  14. Negative Self-Focused Cognitions Mediate the Effect of Trait Social Anxiety on State Anxiety

    PubMed Central

    Schulz, Stefan M.; Alpers, Georg W.; Hofmann, Stefan G.

    2008-01-01

    The cognitive model of social anxiety predicts that negative self-focused cognitions increase anxiety when anticipating social threat. To test this prediction, 36 individuals were asked to anticipate and perform a public speaking task. During anticipation, negative self-focused cognitions or relaxation were experimentally induced while self-reported anxiety, autonomic arousal (heart rate, heart rate variability, skin conductance level), and acoustic eye-blink startle response were assessed. As predicted, negative self-focused cognitions mediated the effects of trait social anxiety on self-reported anxiety and heart rate variability during negative anticipation. Furthermore, trait social anxiety predicted increased startle amplitudes. These findings support a central assumption of the cognitive model of social anxiety. PMID:18321469

  15. Negative self-focused cognitions mediate the effect of trait social anxiety on state anxiety.

    PubMed

    Schulz, Stefan M; Alpers, Georg W; Hofmann, Stefan G

    2008-04-01

    The cognitive model of social anxiety predicts that negative self-focused cognitions increase anxiety when anticipating social threat. To test this prediction, 36 individuals were asked to anticipate and perform a public-speaking task. During anticipation, negative self-focused cognitions or relaxation were experimentally induced while self-reported anxiety, autonomic arousal (heart rate, heart rate variability, skin conductance level), and acoustic eye-blink startle response were assessed. As predicted, negative self-focused cognitions mediated the effects of trait social anxiety on self-reported anxiety and heart rate variability during negative anticipation. Furthermore, trait social anxiety predicted increased startle amplitudes. These findings support a central assumption of the cognitive model of social anxiety. PMID:18321469

  16. Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish

    PubMed Central

    Flynn, Erin E.; Bjelde, Brittany E.; Miller, Nathan A.; Todgham, Anne E.

    2015-01-01

    Anthropogenic CO2 is rapidly causing oceans to become warmer and more acidic, challenging marine ectotherms to respond to simultaneous changes in their environment. While recent work has highlighted that marine fishes, particularly during early development, can be vulnerable to ocean acidification, we lack an understanding of how life-history strategies, ecosystems and concurrent ocean warming interplay with interspecific susceptibility. To address the effects of multiple ocean changes on cold-adapted, slowly developing fishes, we investigated the interactive effects of elevated partial pressure of carbon dioxide (pCO2) and temperature on the embryonic physiology of an Antarctic dragonfish (Gymnodraco acuticeps), with protracted embryogenesis (∼10 months). Using an integrative, experimental approach, our research examined the impacts of near-future warming [−1 (ambient) and 2°C (+3°C)] and ocean acidification [420 (ambient), 650 (moderate) and 1000 μatm pCO2 (high)] on survival, development and metabolic processes over the course of 3 weeks in early development. In the presence of increased pCO2 alone, embryonic mortality did not increase, with greatest overall survival at the highest pCO2. Furthermore, embryos were significantly more likely to be at a later developmental stage at high pCO2 by 3 weeks relative to ambient pCO2. However, in combined warming and ocean acidification scenarios, dragonfish embryos experienced a dose-dependent, synergistic decrease in survival and developed more slowly. We also found significant interactions between temperature, pCO2 and time in aerobic enzyme activity (citrate synthase). Increased temperature alone increased whole-organism metabolic rate (O2 consumption) and developmental rate and slightly decreased osmolality at the cost of increased mortality. Our findings suggest that developing dragonfish are more sensitive to ocean warming and may experience negative physiological effects of ocean acidification only

  17. Ocean acidification exerts negative effects during warming conditions in a developing Antarctic fish.

    PubMed

    Flynn, Erin E; Bjelde, Brittany E; Miller, Nathan A; Todgham, Anne E

    2015-01-01

    Anthropogenic CO2 is rapidly causing oceans to become warmer and more acidic, challenging marine ectotherms to respond to simultaneous changes in their environment. While recent work has highlighted that marine fishes, particularly during early development, can be vulnerable to ocean acidification, we lack an understanding of how life-history strategies, ecosystems and concurrent ocean warming interplay with interspecific susceptibility. To address the effects of multiple ocean changes on cold-adapted, slowly developing fishes, we investigated the interactive effects of elevated partial pressure of carbon dioxide (pCO2) and temperature on the embryonic physiology of an Antarctic dragonfish (Gymnodraco acuticeps), with protracted embryogenesis (∼10 months). Using an integrative, experimental approach, our research examined the impacts of near-future warming [-1 (ambient) and 2°C (+3°C)] and ocean acidification [420 (ambient), 650 (moderate) and 1000 μatm pCO2 (high)] on survival, development and metabolic processes over the course of 3 weeks in early development. In the presence of increased pCO2 alone, embryonic mortality did not increase, with greatest overall survival at the highest pCO2. Furthermore, embryos were significantly more likely to be at a later developmental stage at high pCO2 by 3 weeks relative to ambient pCO2. However, in combined warming and ocean acidification scenarios, dragonfish embryos experienced a dose-dependent, synergistic decrease in survival and developed more slowly. We also found significant interactions between temperature, pCO2 and time in aerobic enzyme activity (citrate synthase). Increased temperature alone increased whole-organism metabolic rate (O2 consumption) and developmental rate and slightly decreased osmolality at the cost of increased mortality. Our findings suggest that developing dragonfish are more sensitive to ocean warming and may experience negative physiological effects of ocean acidification only in

  18. Negative refractive index, perfect lenses and checkerboards: Trapping and imaging effects in folded optical spaces

    NASA Astrophysics Data System (ADS)

    Guenneau, Sébastien; Ramakrishna, S. Anantha

    2009-06-01

    Newly discovered metamaterials have opened new vistas for better control of light via negative refraction, whereby light refracts in the "wrong" manner. These are dielectric and metallic composite materials structured at subwavelength lengthscales. Their building blocks consist of local resonators such as conducting thin bars and split rings driving the material parameters such as the dielectric permittivity and magnetic permeability to negative (complex) values. Combined together, these structural elements can bring about a (complex valued) negative effective refractive index for the Snell-Descartes law and result in negative refraction of radiation. Negative refractive index materials can support a host of surface plasmon states for both polarizations of light. This makes possible unique effects such as imaging with subwavelength image resolution through the Pendry-Veselago slab lens. Other geometries have also been investigated, such as cylindrical or spherical lenses that enable a magnification of images with subwavelength resolution. Superlenses of three-fold (equilateral triangle), four-fold (square) and six-fold (hexagonal) geometry allow for multiple images, respectively two, three, and five. Generalization to rectangular and triangular checkerboards consisting of alternating cells of positive and negative refractive index represents a very singular situation in which the density of modes diverges at the corners, with an infinity of images. Sine-cosecant anisotropic heterogeneous square and triangular checkerboards can be respectively mapped onto three-dimensional cubic and icosahedral corner lenses consisting of alternating positive and negative refractive regions. All such systems with corners between negative and positive refractive media display very singular behavior with the local density of states becoming infinitely large at the corner, in the limit of no dissipation. We investigate all of these, using the unifying viewpoint of transformation optics

  19. Zirconium tungstate/epoxy nanocomposites: effect of nanoparticle morphology and negative thermal expansivity.

    PubMed

    Wu, Hongchao; Rogalski, Mark; Kessler, Michael R

    2013-10-01

    The ability to tailor the coefficient of thermal expansion (CTE) of a polymer is essential for mitigating thermal residual stress and reducing microcracks caused by CTE mismatch of different components in electronic applications. This work studies the effect of morphology and thermal expansivity of zirconium tungstate nanoparticles on the rheological, thermo-mechanical, dynamic-mechanical, and dielectric properties of ZrW2O8/epoxy nanocomposites. Three types of ZrW2O8 nanoparticles were synthesized under different hydrothermal conditions and their distinct properties were characterized, including morphology, particle size, aspect ratio, surface area, and CTE. Nanoparticles with a smaller particle size and larger surface area led to a more significant reduction in gel-time and glass transition temperature of the epoxy nanocomposites, while a higher initial viscosity and significant shear thinning behavior was found in prepolymer suspensions containing ZrW2O8 with larger particle sizes and aspect ratios. The thermo- and dynamic-mechanical properties of epoxy-based nanocomposites improved with increasing loadings of the three types of ZrW2O8 nanoparticles. In addition, the introduced ZrW2O8 nanoparticles did not negatively affect the dielectric constant or the breakdown strength of the epoxy resin, suggesting potential applications of ZrW2O8/epoxy nanocomposites in the microelectronic insulation industry. PMID:24070222

  20. Cochlear outer hair cell bio-inspired metamaterial with negative effective parameters

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Zhang, Siwen

    2016-05-01

    Inspired by periodical outer hair cells (OHCs) and stereocilia clusters of mammalian cochlear, a type of bio-inspired metamaterial with negative effective parameters based on the OHC structure is proposed. With the structural parameters modified and some common engineering materials adopted, the bio-inspired structure design with length scales of millimeter and lightweight is presented, and then, a bending wave bandgap in a favorable low-frequency with width of 55 Hz during the interval 21-76 or 116 Hz during the interval 57-173 Hz is obtained, i.e., the excellent low-frequency acoustic performance turns up. Compared with the local resonance unit in previous literatures, both the size and weight are greatly reduced in our bio-inspired structure. In addition, the lower edge of low-frequency bandgap is reduced by an order of magnitude, almost to the lower limit frequency of the hearing threshold as well, which achieves an important breakthrough on the aspect of low-frequency and great significance on the noise and vibration reduction in low-frequency range.

  1. Effect of jenny milk addition on the inhibition of late blowing in semihard cheese.

    PubMed

    Cosentino, C; Paolino, R; Valentini, V; Musto, M; Ricciardi, A; Adduci, F; D'Adamo, C; Pecora, G; Freschi, P

    2015-08-01

    The occurrence of late blowing defects in cheese produces negative effects on the quality and commercial value of the product. In this work, we verified whether the addition of raw jenny milk to bulk cow milk reduced the late blowing defects in semihard cheeses. During cheesemaking, different aliquots of jenny milk were poured into 2 groups of 4 vats, each containing a fixed amount of cow milk. A group of cheeses was created by deliberately contaminating the 4 vats with approximately 3 log10 cfu/mL milk of Clostridium tyrobutyricum CLST01. The other 4 vats, which were not contaminated, were used for a second group of cheeses. After 120 d of ripening, some physical, chemical, and microbiological parameters were evaluated on the obtained semihard cheeses. Differences in sensory properties among cheeses belonging to the uncontaminated group were evaluated by 80 regular consumers of cheese. Our results showed that the increasing addition of jenny milk to cow milk led to a reduction of pH and total bacterial count in both cheese groups, as well as C. tyrobutyricum spores that either grew naturally or artificially inoculated. We observed a progressive reduction of the occurrence of late blowing defects in cheese as consequence of the increasing addition of jenny milk during cheese making. Moreover, the addition of jenny milk did not affect the acceptability of the product, as consumers found no difference among cheeses concerning sensorial aspects. In conclusion, the important antimicrobial activity of lysozyme contained in jenny milk has been confirmed in the current research. It is recommend for use as a possible and viable alternative to egg lysozyme for controlling late blowing defects in cheese. PMID:26074234

  2. Electrified emotions: Modulatory effects of transcranial direct stimulation on negative emotional reactions to social exclusion.

    PubMed

    Riva, Paolo; Romero Lauro, Leonor J; Vergallito, Alessandra; DeWall, C Nathan; Bushman, Brad J

    2015-01-01

    Social exclusion, ostracism, and rejection can be emotionally painful because they thwart the need to belong. Building on studies suggesting that the right ventrolateral prefrontal cortex (rVLPFC) is associated with regulation of negative emotions, the present experiment tests the hypothesis that decreasing the cortical excitability of the rVLPFC may increase negative emotional reactions to social exclusion. Specifically, we applied cathodal transcranial direct current stimulation (tDCS) over the rVLPFC and predicted an increment of negative emotional reactions to social exclusion. In Study 1, participants were either socially excluded or included, while cathodal tDCS or sham stimulation was applied over the rVLPFC. Cathodal stimulation of rVLPFC boosted the typical negative emotional reaction caused by social exclusion. No effects emerged from participants in the inclusion condition. To test the specificity of tDCS effects over rVLPFC, in Study 2, participants were socially excluded and received cathodal tDCS or sham stimulation over a control region (i.e., the right posterior parietal cortex). No effects of tDCS stimulation were found. Our results showed that the rVLPFC is specifically involved in emotion regulation and suggest that cathodal stimulation can increase negative emotional responses to social exclusion. PMID:25139575

  3. Asymmetric effect of automatic deviant detection: The effect of familiarity in visual mismatch negativity.

    PubMed

    Sulykos, István; Kecskés-Kovács, Krisztina; Czigler, István

    2015-11-11

    The visual mismatch negativity (vMMN) component is regarded as a prediction error signal elicited by events violating the sequential regularities of environmental stimulation. The aim of the study was to investigate the effect of familiarity on the vMMN. Stimuli were patterns comprised of familiar (N) or unfamiliar (И) letters. In a passive oddball paradigm, letters (N and И) were presented as either standard or deviant in separate conditions. VMMNs emerged in both conditions; peak latency of vMMN was shorter to the И deviant compared to the vMMN elicited by the N deviant. To test the orientation-specific effect of the oblique lines on the vMMN, we introduced a control experiment. In the control experiment, the patterns were constructed solely from oblique lines, identical to the oblique lines of the N and И stimuli. Contrary to the first experiment, there was no significant difference between the vMNNs elicited by the two orientations. Therefore, the differences in vMMNs to И and N deviants are not attributable to the physical difference between the И and N stimuli. Consequently, the vMMN is sensitive to the familiarity of the stimuli. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:25724142

  4. Effects of Increased Summer Precipitation and Nitrogen Addition on Root Decomposition in a Temperate Desert

    PubMed Central

    Zhao, Hongmei; Huang, Gang; Li, Yan; Ma, Jian; Sheng, Jiandong; Jia, Hongtao; Li, Congjuan

    2015-01-01

    Background Climate change scenarios that include precipitation shifts and nitrogen (N) deposition are impacting carbon (C) budgets in arid ecosystems. Roots constitute an important part of the C cycle, but it is still unclear which factors control root mass loss and nutrient release in arid lands. Methodology/Principal Findings Litterbags were used to investigate the decomposition rate and nutrient dynamics in root litter with water and N-addition treatments in the Gurbantunggut Desert in China. Water and N addition had no significant effect on root mass loss and the N and phosphorus content of litter residue. The loss of root litter and nutrient releases were strongly controlled by the initial lignin content and the lignin:N ratio, as evidenced by the negative correlations between decomposition rate and litter lignin content and the lignin:N ratio. Fine roots of Seriphidium santolinum (with higher initial lignin content) had a slower decomposition rate in comparison to coarse roots. Conclusion/Significance Results from this study indicate that small and temporary changes in rainfall and N deposition do not affect root decomposition patterns in the Gurbantunggut Desert. Root decomposition rates were significantly different between species, and also between fine and coarse roots, and were determined by carbon components, especially lignin content, suggesting that root litter quality may be the primary driver of belowground carbon turnover. PMID:26544050

  5. The effect of suppressing negative emotions on eating behavior in binge eating disorder.

    PubMed

    Dingemans, Alexandra E; Martijn, Carolien; Jansen, Anita T M; van Furth, Eric F

    2009-02-01

    Overeating may be a consequence of the suppression of negative emotions, by depleting self-control resources. This experiment investigated whether (a) there is a causal relationship between the suppression of negative emotions, negative mood, and overeating in people with binge eating disorder (BED) and whether (b) this relationship is increased in depressed people with BED. Sixty-six women with (full and sub-threshold) BED were shown an upsetting movie and then asked either to suppress their emotions or to react naturally. Subsequently, everyone participated in a taste task. After a decline, initial mood before watching the movie was restored after eating. Depressive symptomatology was positively correlated with caloric intake. Within the clinically depressed (Beck Depression Inventory-score>19) BED group, those who were most affected by the negative mood induction consumed the most calories. No differences were found between the two conditions with regard to caloric intake. No interaction effect was found between depressive symptoms and mood suppression. The hypothesis that suppression of negative emotion leads to overeating in (depressed) binge eaters was not born out. Overeating may serve as a means to (temporary) repair negative mood. PMID:18778742

  6. Differential effects of negative publicity on beef consumption according to household characteristics in South Korea.

    PubMed

    Youn, Hyungho; Lim, Byung In; Jin, Hyun Joung

    2012-07-01

    This paper examines how South Korean households responded to an unprecedented boycott campaign against US beef from spring to summer of 2008, and investigates differential responses in relation to households' characteristics. It was found that beef consumption reduced by 4.8% immediately after the so-called candle-light demonstration. Instead, pork and chicken consumption increased by 17.2% and 16.6%, respectively. This confirms a substitution effect due to the negative publicity concerning US beef. It was also found that the negative publicity effect was transitory and the reactions of consumers were not uniform; they differed depending on their socio-economic characteristics. The econometric model revealed that younger, less-educated, and/or lower-income households were more susceptible to the negative publicity, and reduced their beef consumption more than other households. PMID:22482492

  7. Comparing the Effects of Negative and Mixed Emotional Messages on Predicted Occasional Excessive Drinking

    PubMed Central

    Carrera, Pilar; Caballero, Amparo; Muñoz, Dolores

    2008-01-01

    In this work we present two types of emotional message, negative (sadness) versus mixed (joy and sadness), with the aim of studying their differential effect on attitude change and the probability estimated by participants of repeating the behavior of occasional excessive drinking in the near future. The results show that for the group of participants with moderate experience in this behavior the negative message, compared to the mixed one, is associated with higher probability of repeating the risk behavior and a less negative attitude toward it. These results suggest that mixed emotional messages (e.g. joy and sadness messages) could be more effective in campaigns for the prevention of this risk behavior. PMID:25977606

  8. Effects of negative outcome on food consumption in college women with and without troubled eating patterns.

    PubMed

    Kisler, V A; Corcoran, K J

    1997-01-01

    This study looked at the effects that failure experiences have on food consumption and their effect on college women. Part I of the study (N = 169) was used to screen subjects for Part II (N = 55) based on scores on the Bulimia Test-Revised. In part II, eating-disordered and control participants completed one of two types of tasks-a negative outcome and a neutral outcome control task. Following the task, a bogus cookie rating task provided the opportunity for participants to eat chocolate chip cookies. Mood was assessed throughout Part II. Results indicate that mood was more negative following the negative outcome task. Eating-disordered participants ate more than did controls in this same condition; these participants also reported improved mood after eating. PMID:9290856

  9. Pervasive negative effects of rewards on intrinsic motivation: The myth continues

    PubMed Central

    Cameron, Judy; Banko, Katherine M.; Pierce, W. David

    2001-01-01

    A major concern in psychology and education is that rewards decrease intrinsic motivation to perform activities. Over the past 30 years, more than 100 experimental studies have been conducted on this topic. In 1994, Cameron and Pierce conducted a meta-analysis of this literature and concluded that negative effects of reward were limited and could be easily prevented in applied settings. A more recent meta-analysis of the literature by Deci, Koestner, and Ryan (1999) shows pervasive negative effects of reward. The purpose of the present article is to resolve differences in previous meta-analytic findings and to provide a meta-analysis of rewards and intrinsic motivation that permits tests of competing theoretical explanations. Our results suggest that in general, rewards are not harmful to motivation to perform a task. Rewards given for low-interest tasks enhance free-choice intrinsic motivation. On high-interest tasks, verbal rewards produce positive effects on free-choice motivation and self-reported task interest. Negative effects are found on high-interest tasks when the rewards are tangible, expected (offered beforehand), and loosely tied to level of performance. When rewards are linked to level of performance, measures of intrinsic motivation increase or do not differ from a nonrewarded control group. Overall, the pattern of results indicates that reward contingencies do not have pervasive negative effects on intrinsic motivation. Theoretical and practical implications of the findings are addressed. PMID:22478353

  10. RRAD inhibits the Warburg effect through negative regulation of the NF-κB signaling

    PubMed Central

    Wu, Rui; Lin, Meihua; Liang, Yingjian; Liu, Jia; Wang, Xiaolong; Yang, Bo; Feng, Zhaohui

    2015-01-01

    Cancer cells preferentially use aerobic glycolysis to meet their increased energetic and biosynthetic demands, a phenomenon known as the Warburg effect. Its underlying mechanism is not fully understood. RRAD, a small GTPase, is a potential tumor suppressor in lung cancer. RRAD expression is frequently down-regulated in lung cancer, which is associated with tumor progression and poor prognosis. Recently, RRAD was reported to repress the Warburg effect, indicating that down-regulation of RRAD expression is an important mechanism contributing to the Warburg effect in lung cancer. However, the mechanism by which RRAD inhibits the Warburg effect remains unclear. Here, we found that RRAD negatively regulates the NF-κB signaling to inhibit the GLUT1 translocation and the Warburg effect in lung cancer cells. Mechanically, RRAD directly binds to the p65 subunit of the NF-κB complex and inhibits the nuclear translocation of p65, which in turn negatively regulates the NF-κB signaling to inhibit GLUT1 translocation and the Warburg effect. Blocking the NF-κB signaling largely abolishes the inhibitory effects of RRAD on the translocation of GLUT1 to the plasma membrane and the Warburg effect. Taken together, our results revealed a novel mechanism by which RRAD negatively regulates the Warburg effect in lung cancer cells. PMID:25893381

  11. The effects of CO2 on the negative reactant ions of IMS

    NASA Technical Reports Server (NTRS)

    Spangler, Glenn E.

    1995-01-01

    In the presence of CO2, the negative reactant ions of ion mobility spectrometry (IMS) are ion clusters of CO4(-) and CO3(-). Methyl salicylate is ionized by the CO4(-)(H2O(n))(N2(m)) reactant ions, but not by the CO3(-)(H2O(n))(N2(m)) reactant ions. While the CO4(-) ions are formed by direct association, the CO3(-) ions require additional energy to be formed. The additional energy is provided by either excited neutral gas molecules in a metastable state or UV (ultraviolet) radiation.

  12. Biases in Ratings of Disruptive Behavior in Children: Effects of Sex and Negative Halos

    ERIC Educational Resources Information Center

    Hartung, Cynthia M.; Van Pelt, Jill C.; Armendariz, Monica L.; Knight, Laura A.

    2006-01-01

    Objective: Behavior disorders are more prevalent among boys than girls, but the etiology of this difference is unclear. Studies have not tested for sex bias in ratings as a contributing factor to the differential sex prevalence rates. However, there are several studies showing "negative halo effects" in ratings of boys (i.e., the presence of one…

  13. Effect of Items Direction (Positive or Negative) on the Reliability in Likert Scale. Paper-11

    ERIC Educational Resources Information Center

    Gul, Showkeen Bilal Ahmad; Qasem, Mamun Ali Naji; Bhat, Mehraj Ahmad

    2015-01-01

    In this paper an attempt was made to analyze the effect of items direction (positive or negative) on the Alpha Cronbach reliability coefficient and the Split Half reliability coefficient in Likert scale. The descriptive survey research method was used for the study and sample of 510 undergraduate students were selected by used random sampling…

  14. From Sunshine to Double Arrows: An Evaluation Window Account of Negative Compatibility Effects

    ERIC Educational Resources Information Center

    Klauer, Karl Christoph; Dittrich, Kerstin

    2010-01-01

    In category priming, target stimuli are to be sorted into 2 categories. Prime stimuli preceding targets typically facilitate processing of targets when primes and targets are members of the same category, relative to the case in which both stem from different categories, a positive compatibility effect (PCE). But negative compatibility effects…

  15. The Effects of Concreteness and Negation on the Difficulty of Hypothetical, Disjunctive and Linear Syllogisms.

    ERIC Educational Resources Information Center

    Hample, Dale

    Three studies investigated the effects of concrete versus abstract wording and negative versus positive premises on the difficulty subjects had in solving several kinds of reasoning tasks. Subjects for all three studies were college undergraduates who received booklets containing either hypothetical, disjunctive, or linear syllogisms. Each booklet…

  16. Effectiveness of crizotinib in a patient with ALK IHC-positive/FISH-negative metastatic lung adenocarcinoma.

    PubMed

    Rosoux, A; Pauwels, P; Duplaquet, F; D'Haene, N; Weynand, B; Delos, M; Menon, R; Heukamp, L C; Thunnissen, E; Ocak, S

    2016-08-01

    We report a case of crizotinib effectiveness in a heavily pretreated patient with a metastatic NSCLC initially considered IHC-positive and FISH-negative for ALK rearrangement. After repeated analyses of tumor samples, borderline ALK FISH-positivity (18.5% positive cells) was demonstrated. PMID:27393517

  17. Graduate School and the Self: A Theoretical View of Some Negative Effects of Professional Socialization.

    ERIC Educational Resources Information Center

    Egan, Janet Malenchek

    1989-01-01

    Proposes a conceptualization of the professionalization that is inherent in graduate school training as resocialization rather than developmental socialization. Discusses the possible negative effects of this process on students' self-concept. Responses by Jane Allyn Piliavin, Norman Goodman, and Joan Aldous follow. (LS)

  18. Rewarding Multitasking: Negative Effects of an Incentive on Problem Solving under Divided Attention

    ERIC Educational Resources Information Center

    Wieth, Mareike B.; Burns, Bruce D.

    2014-01-01

    Research has consistently shown negative effects of multitasking on tasks such as problem solving. This study was designed to investigate the impact of an incentive when solving problems in a multitasking situation. Incentives have generally been shown to increase problem solving (e.g., Wieth & Burns, 2006), however, it is unclear whether an…

  19. Theoretical Basis of the Test-Negative Study Design for Assessment of Influenza Vaccine Effectiveness.

    PubMed

    Sullivan, Sheena G; Tchetgen Tchetgen, Eric J; Cowling, Benjamin J

    2016-09-01

    Influenza viruses undergo frequent antigenic changes. As a result, the viruses circulating change within and between seasons, and the composition of the influenza vaccine is updated annually. Thus, estimation of the vaccine's effectiveness is not constant across seasons. In order to provide annual estimates of the influenza vaccine's effectiveness, health departments have increasingly adopted the "test-negative design," using enhanced data from routine surveillance systems. In this design, patients presenting to participating general practitioners with influenza-like illness are swabbed for laboratory testing; those testing positive for influenza virus are defined as cases, and those testing negative form the comparison group. Data on patients' vaccination histories and confounder profiles are also collected. Vaccine effectiveness is estimated from the odds ratio comparing the odds of testing positive for influenza among vaccinated patients and unvaccinated patients, adjusting for confounders. The test-negative design is purported to reduce bias associated with confounding by health-care-seeking behavior and misclassification of cases. In this paper, we use directed acyclic graphs to characterize potential biases in studies of influenza vaccine effectiveness using the test-negative design. We show how studies using this design can avoid or minimize bias and where bias may be introduced with particular study design variations. PMID:27587721

  20. The Effects of Positive and Negative Mood on Cognition and Motivation in Multimedia Learning Environment

    ERIC Educational Resources Information Center

    Liew, Tze Wei; Tan, Su-Mae

    2016-01-01

    The Cognitive-Affective Theory of Learning with Media framework posits that the multimedia learning process is mediated by the learner's mood. Recent studies have shown that positive mood has a facilitating effect on multimedia learning. Though literature has shown that negative mood encourages an individual to engage in a more systematic,…

  1. Selective Attention and Inhibitory Deficits in ADHD: Does Subtype or Comorbidity Modulate Negative Priming Effects?

    ERIC Educational Resources Information Center

    Pritchard, Verena E.; Neumann, Ewald; Rucklidge, Julia J.

    2008-01-01

    Selective attention has durable consequences for behavior and neural activation. Negative priming (NP) effects are assumed to reflect a critical inhibitory component of selective attention. The performance of adolescents with Attention Deficit/Hyperactivity Disorder (ADHD) was assessed across two conceptually based NP tasks within a selective…

  2. The Presence of a Best Friend Buffers the Effects of Negative Experiences

    ERIC Educational Resources Information Center

    Adams, Ryan E.; Santo, Jonathan Bruce; Bukowski, William M.

    2011-01-01

    The goal of the current study was to examine how the presence of a best friend might serve as protection against the effect of negative experiences on global self-worth and the hypothalamic-pituitary-adrenocortical axis (HPA axis). A total of 103 English-speaking male (n = 55) and female (n = 48) participants from Grade 5 (M = 10.27 years) and…

  3. Using an Electronic Highlighter to Eliminate the Negative Effects of Pre-Existing, Inappropriate Highlighting

    ERIC Educational Resources Information Center

    Gier, Vicki; Kreiner, David; Hudnell, Jason; Montoya, Jodi; Herring, Daniel

    2011-01-01

    The purpose of the present experiment was to determine whether using an active learning technique, electronic highlighting, can eliminate the negative effects of pre-existing, poor highlighting on reading comprehension. Participants read passages containing no highlighting, appropriate highlighting, or inappropriate highlighting. We hypothesized…

  4. The Negative Effects of Prejudice on Interpersonal Relationships within Adolescent Peer Groups

    ERIC Educational Resources Information Center

    Poteat, V. Paul; Mereish, Ethan H.; Birkett, Michelle

    2015-01-01

    Social development theories highlight the centrality of peer groups during adolescence and their role in socializing attitudes and behaviors. In this longitudinal study, we tested the effects of group-level prejudice on ensuing positive and negative interpersonal interactions among peers over a 7-month period. We used social network analysis to…

  5. Comparison of the Frequency and Effectiveness of Positive and Negative Reinforcement Practices in Schools

    ERIC Educational Resources Information Center

    Dad, Hukam; Ali, Riasat; Janjua, Muhammad Zaigham Qadeer; Shahzad, Saqib; Khan, Muhammad Saeed

    2010-01-01

    The major purpose of the study was to compare the frequency and effectiveness of positive and negative reinforcement practices deployed by teachers in boys' and girls' secondary schools in urban and rural areas. It was hypothesized that there would be no difference in use of reward and punishment by teachers in secondary schools in urban and rural…

  6. The negative effect of biocrusts upon annual-plant growth on sand dunes during extreme droughts

    NASA Astrophysics Data System (ADS)

    Kidron, Giora J.

    2014-01-01

    The moisture content of crusted and non-crusted habitats on sand was measured.Higher available water characterized the non-crusted habitats during drought years.Non-crusted habitats had higher species diversity, density and biomass.Crusts exert a negative effect on annual plants during droughts.Mobile sand serve as fertility belts for annual plants during drought years.

  7. [Negative effects of anti-nutritional factors from soybeans in Salmonidae].

    PubMed

    van den Ingh, T S; Krogdahl, A

    1990-10-15

    Soya bean products are used with increasing frequency in diets for salmonids. Soya beans however contain antinutritional factors (ANF), like protease inhibitors and lectins, which may decrease growth performance and even cause disease. The paper reviews the literature and adds some recent developments to the knowledge on the negative effects of ANF from soya beans in salmonids. PMID:2281471

  8. The Effects of Different Drawing Materials on Children's Drawings of Positive and Negative Human Figures

    ERIC Educational Resources Information Center

    Burkitt, Esther; Barrett, Martyn

    2011-01-01

    Children tend to use certain drawing strategies differentially when asked to draw topics with positive and negative emotional characterisations. These effects have however only been established when children are asked to use standard drawing materials. The present study was designed to investigate whether the above pattern of children's response…

  9. CXCR4 Protein Epitope Mimetic Antagonist POL5551 Disrupts Metastasis and Enhances Chemotherapy Effect in Triple-Negative Breast Cancer.

    PubMed

    Xiang, Jingyu; Hurchla, Michelle A; Fontana, Francesca; Su, Xinming; Amend, Sarah R; Esser, Alison K; Douglas, Garry J; Mudalagiriyappa, Chidananda; Luker, Kathryn E; Pluard, Timothy; Ademuyiwa, Foluso O; Romagnoli, Barbara; Tuffin, Gérald; Chevalier, Eric; Luker, Gary D; Bauer, Michael; Zimmermann, Johann; Aft, Rebecca L; Dembowsky, Klaus; Weilbaecher, Katherine N

    2015-11-01

    The SDF-1 receptor CXCR4 has been associated with early metastasis and poorer prognosis in breast cancers, especially the most aggressive triple-negative subtype. In line with previous reports, we found that tumoral CXCR4 expression in patients with locally advanced breast cancer was associated with increased metastases and rapid tumor progression. Moreover, high CXCR4 expression identified a group of bone marrow-disseminated tumor cells (DTC)-negative patients at high risk for metastasis and death. The protein epitope mimetic (PEM) POL5551, a novel CXCR4 antagonist, inhibited binding of SDF-1 to CXCR4, had no direct effects on tumor cell viability, but reduced migration of breast cancer cells in vitro. In two orthotopic models of triple-negative breast cancer, POL5551 had little inhibitory effect on primary tumor growth, but significantly reduced distant metastasis. When combined with eribulin, a chemotherapeutic microtubule inhibitor, POL5551 additively reduced metastasis and prolonged survival in mice after resection of the primary tumor compared with single-agent eribulin. Hypothesizing that POL5551 may mobilize tumor cells from their microenvironment and sensitize them to chemotherapy, we used a "chemotherapy framing" dosing strategy. When administered shortly before and after eribulin treatment, three doses of POL5551 with eribulin reduced bone and liver tumor burden more effectively than chemotherapy alone. These data suggest that sequenced administration of CXCR4 antagonists with cytotoxic chemotherapy synergize to reduce distant metastases. PMID:26269605

  10. Anthelmintic effects of phytogenic feed additives in Ascaris suum inoculated pigs.

    PubMed

    van Krimpen, M M; Binnendijk, G P; Borgsteede, F H M; Gaasenbeek, C P H

    2010-03-25

    Two experiments were performed to determine the anthelmintic effect of some phytogenic feed additives on a mild infection of Ascaris suum in growing and finishing pigs. Usually, an infection of A. suum is controlled by using conventional synthetic drugs. Organic farmers, however, prefer a non-pharmaceutical approach to worm control. Therefore, phytotherapy could be an appropriate alternative. In the first experiment, a commercial available organic starter diet was supplemented with 3% of a herb mixture, adding 1% Thymus vulgaris, 1% Melissa officinalis and 1% Echinacea purpurea to the diet, or with 4% of a herb mixture, thereby adding the mentioned herbs plus 1% Camellia sinensis (black tea). A negative control group (no treatment) and a positive control group (treatment with conventional synthetic drug flubendazole) were included. In the second experiment, the anthelmintic properties against A. suum of three individual herbs, Carica papaya, Peumus boldus and Artemisia vulgaris, each in a dose of 1%, were tested. Pigs were infected with 1000 infective worm eggs each. Each experiment was performed with 32 individually housed growing pigs (8 replicates/treatment), which were monitored for 67 days. It was hypothesized that the herbs would block the cycles of the larvae, thereby preventing the development of adult worms. Therefore, phytogenic feed additives were not supplied during the whole experimental period, but only from the start until D39. Pigs were inoculated with infective worm eggs during five consecutive days (D17-D21). At D67 all pigs were dissected, whereafter livers were checked for the presence of white spots. Also numbers of worms in the small intestine were counted. In experiment 1, the numbers of worm-infected pigs were similar for both the herb supplemented (groups 3 and 4) and the unsupplemented (group 1) treatments (5-6 pigs of 8), while the treatment with flubendazole (group 2) resulted in 0 infected pigs. In experiment 2, herb addition (groups 2

  11. Comparative late effects of X-rays and negative pimesons on the mouse kidney.

    PubMed Central

    Jordan, S. W.; Yuhas, J. M.; Key, C. R.; Hogstrom, K. R.; Butler, J. L.; Kligerman, M. M.

    1979-01-01

    A system is described for comparing various modalities and fractionation schedules of radiation by means of their long-term morphologic effects upon the mouse kidney. The comparison system utilizes a grading scale for histopathologic changes in which a given histologic grade depends upon meeting defined threshold criteria, rather than quantitation of a particular measurement. Renal tubular alterations served as the basis for comparison, since they appeared more reliably defined than glomerular changes. The radiation dose that induced a specific threshold effect in kidneys from 50% of the animals at 6 months was defined as the effective dose-50%, or ED50.ED50 was found for x-rays and negative pimesons administered in 1, 2, or 5 fractions. From these data, the relative biologic effectiveness (RBE) of negative pi-mesons with respect to x-rays was determined for each fractionation schedule. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:525675

  12. Muscarinic receptors mediate negative and positive inotropic effects in mammalian ventricular myocardium: differentiation by agonists.

    PubMed Central

    Korth, M.; Kühlkamp, V.

    1987-01-01

    The concentration-dependence of the negative and positive inotropic effect of choline esters and of oxotremorine was studied in isometrically contracting papillary muscles of the guinea-pig. The preparations were obtained from reserpine-pretreated animals and were electrically driven at a frequency of 0.2 Hz. In the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methyl xanthine (IBMX, 100 mumol l-1), choline esters and oxotremorine produced concentration-dependent negative inotropic effects. Oxotremorine exhibited the highest negative inotropic potency (with a half-maximal effective concentration, EC50, of 20 nmol l-1) followed by carbachol (139 nmol l-1), methacholine (490 nmol l-1), acetylcholine in the presence of 10 mumol l-1 physostigmine (1.36 mumol l-1) and bethanechol (10 mumol l-1). Atropine was a competitive antagonist of the negative inotropic effects. Carbachol and oxotremorine decreased Vmax, overshoot and duration of slow Ca2+-dependent action potentials which had been elicited in the presence of 100 mumol l-1 IBMX. Choline esters produced a concentration-dependent positive inotropic effect. With an EC50 of 32 mumol l-1, carbachol was the most potent compound, followed by methacholine (35 mumol l-1), acetylcholine in the presence of 10 mumol l-1 physostigmine (46 mumol l-1) and bethanechol (142 mumol l-1). Compared to carbachol and methacholine which increased force by 100% of control, the increase induced by acetylcholine and bethanechol was only 64 and 58%, respectively. Atropine shifted the concentration-effect curves of all choline esters to higher concentrations. Choline esters caused intracellular Na+ activity to increase in the quiescent papillary muscle. This effect was reversed by atropine. Oxotremorine produced a small concentration-dependent positive inotropic effect (about 30% of the maximal effect of carbachol) which was resistant to atropine. Oxotremorine was a potent inhibitor of the positive inotropic effect of choline esters

  13. [The effect of netilmicin on gram negative rods isolated in the Konya region].

    PubMed

    Sengil, A Z; Ozenci, H; Altindiş, M; Erdoğan, E

    1988-01-01

    Netilmicin, was tested for the effect against 276 isolates of gram negative bacteria, before had used in Konya region. 15.9% of the isolates were resistant and 84.1% were sensitive to netilmicin. The effects of Netilmicin and gentamicin for 50 Pseudomonas isolates were compared. The other aminoglycosides also were tested against isolates of the bacterium, amikacin was the most active one. PMID:3252118

  14. The hysteresis-free negative capacitance field effect transistors using non-linear poly capacitance

    NASA Astrophysics Data System (ADS)

    Fan, S.-T.; Yan, J.-Y.; Lai, D.-C.; Liu, C. W.

    2016-08-01

    A gate structure design for negative capacitance field effect transistors (NCFETs) is proposed. The hysteresis loop in current-voltage performances is eliminated by the nonlinear C-V dependence of polysilicon in the gate dielectrics. Design considerations and optimizations to achieve the low SS and hysteresis-free transfer were elaborated. The effects of gate-to-source/drain overlap, channel length scaling, interface trap states and temperature impact on SS are also investigated.

  15. Positive and Negative Interactions Observed Between Siblings: Moderating Effects for Children Exposed to Parents’ Conflict

    PubMed Central

    Iturralde, Esti; Margolin, Gayla; Spies Shapiro, Lauren A.

    2012-01-01

    This study investigated links between interparental conflict appraisals (specifically threat and self-blame), sibling relationship quality (positive and negative dimensions), and anxiety in sibling pairs comprised of an adolescent and a younger sibling close in age. Sibling relationship quality was measured through behavioral observation. Links between self-blame and anxiety were moderated by sibling relationship quality. In older siblings, positive behavior with a sibling was associated with an attenuated relation between self-blame and anxiety. A paradoxical moderating effect was found for negative interactions; for both younger and older siblings, a relation between self-blame and anxiety was weakened in the presence of sibling negativity. Results offered support for theorized benefits of sibling relationship quality in helping early adolescents adjust to conflict between parents. PMID:24244080

  16. Coping self-efficacy mediates the effects of negative cognitions on posttraumatic distress.

    PubMed

    Cieslak, Roman; Benight, Charles C; Caden Lehman, Victoria

    2008-07-01

    Although cognitive distortions have predicted posttraumatic distress after various types of traumatic events, the mechanisms through which cognitive distortions influence posttraumatic distress remain unclear. We hypothesized that coping self-efficacy, the belief in one's own ability to manage posttraumatic recovery demands, would operate as a mediator between negative cognitions (about self, about the world, and self-blame beliefs) and posttraumatic distress. In the cross-sectional Study 1, data collected among 66 adult female victims of child sexual abuse indicated that coping self-efficacy mediated the effects of negative cognitions about self and about the world on posttraumatic distress. The same pattern of results was found in a longitudinal Study 2, conducted among 70 survivors of motor vehicle accidents. Coping self-efficacy measured at 1 month after the trauma mediated the effects of 7-day negative cognitions about self and about the world on 3-month posttraumatic distress. In both studies self-blame was not related to posttraumatic distress and the effect of self-blame on posttraumatic distress was not mediated by coping self-efficacy. The results provide insight into a mechanism through which negative cognitions may affect posttraumatic distress and highlight the potential importance of interventions aimed at enhancing coping self-efficacy beliefs. PMID:18456241

  17. Negative Magnus Effect on a Rotating Sphere at around the Critical Reynolds Number

    NASA Astrophysics Data System (ADS)

    Muto, Masaya; Watanabe, Hiroaki; Tsubokura, Makoto; Oshima, Nobuyuki

    2011-12-01

    Negative Magnus lift acting on a sphere rotating about the axis perpendicular to an incoming flow is investigated using large-eddy simulation at three Reynolds numbers of 1.0× 104, 2.0 × 105, and 1.14 × 106. The numerical methods adopted are first validated on a non-rotating sphere and the spatial resolution around the sphere is determined so as to reproduce the laminar separation, reattachment, and turbulent transition of the boundary layer observed at around the critical Reynolds number. In the rotating sphere, positive or negative Magnus effect is observed depending on the Reynolds number and the rotating speed imposed. At the Reynolds number in the subcritical or supercritical region, the direction of the lift force follows the Magnus effect to be independent of the rotational speed tested here. In contrast, negative lift is observed at the Reynolds number at the critical region when particular rotating speeds are imposed. The negative Magnus effect is discussed in the context of the suppression or promotion of boundary layer transition around the separation point.

  18. Distracted by pleasure: Effects of positive versus negative valence on emotional capture under load.

    PubMed

    Gupta, Rashmi; Hur, Young-Jin; Lavie, Nilli

    2016-04-01

    We report 3 experiments examining the effects of positive versus negative valence and perceptual load in determining attention capture by irrelevant emotional distractors. Participants performed a letter search task searching for 1 of 2 target letters (X or N) in conditions of either low perceptual load (circular nontarget letters) or high perceptual load (angular nontarget letters that are similar to the target letters). On 25% of the trials an irrelevant emotional distractor was presented at the display center and participants were instructed to ignore it. The distractor stimulus was either positive or negative and was selected from 3 different classes: IAPS pictures of erotica or mutilated bodies (Experiment 1), happy or angry faces (Experiment 2), and faces associated with gain or loss in a prior value-learning phase involving a betting game (Experiment 3). The results showed a consistent pattern of interaction of load and valence across the 3 experiments. Irrelevant emotional distractors produced interference effects on search reaction time (RT) in conditions of low load, with no difference between negative and positive valence. High perceptual load, however, consistently reduced interference from the negative-valence distractors, but had no effect on the positive-valence distractors. As these results were consistently found across 3 different categories of emotional distractors, they suggest the general conclusion that attentional capture by irrelevant emotional distractors depends on both their valence and the level of perceptual load in the task and highlight the special status of distractors associated with pleasure. PMID:26479771

  19. Influenza vaccine effectiveness: potential of the test-negative design. A systematic review

    PubMed Central

    Sullivan, Sheena G; Feng, Shuo; Cowling, Benjamin J

    2014-01-01

    SUMMARY Background The test-negative design is a variant of the case control study being increasingly used to study influenza vaccine effectiveness. In these studies, patients with influenza-like illness are tested for influenza. Vaccine coverage is compared between those testing positive versus those testing negative to estimate vaccine effectiveness. Objectives We reviewed features in the design, analysis and reporting of 85 published test-negative studies. Data sources Studies were identified from PubMed, reference lists and email updates. Study eligibility All studies using the test-negative design reporting end-of-season estimates were included. Study appraisal Design features that may affect the validity and comparability of reported estimates were reviewed, including setting, study period, source population, case definition, exposure and outcome ascertainment and statistical model. Results There was considerable variation in the analytic approach, with 68 unique statistical models identified among the studies. Conclusion Harmonisation of analytic approaches may improve the potential for pooling vaccine effectiveness estimates. PMID:25348015

  20. Coping Self-Efficacy Mediates the Effects of Negative Cognitions on Posttraumatic Distress

    PubMed Central

    Cieslak, Roman; Benight, Charles C.; Lehman, Victoria Caden

    2008-01-01

    Although cognitive distortions have predicted posttraumatic distress after various types of traumatic events, the mechanisms through which cognitive distortions influence posttraumatic distress remain unclear. We hypothesized that coping self-efficacy, the belief in one’s own ability to manage posttraumatic recovery demands, would operate as a mediator between negative cognitions (about self, about the world, and self-blame beliefs) and posttraumatic distress. In the cross-sectional Study 1, data collected among 66 adult female victims of child sexual abuse indicated that coping self-efficacy mediated the effects of negative cognitions about self and about the world on posttraumatic distress. The same pattern of results was found in a longitudinal Study 2, conducted among 70 survivors of motor vehicle accidents. Coping self-efficacy measured at 1 month after the trauma mediated the effects of 7-day negative cognitions about self and about the world on 3-month posttraumatic distress. In both studies self-blame was not related to posttraumatic distress and the effect of self-blame on posttraumatic distress was not mediated by coping self-efficacy. The results provide insight into a mechanism through which negative cognitions may affect posttraumatic distress and highlight the potential importance of interventions aimed at enhancing coping self-efficacy beliefs. PMID:18456241

  1. Effectiveness of group body psychotherapy for negative symptoms of schizophrenia: multicentre randomised controlled trial†

    PubMed Central

    Priebe, S.; Savill, M.; Wykes, T.; Bentall, R. P.; Reininghaus, U.; Lauber, C.; Bremner, S.; Eldridge, S.; Röhricht, F.

    2016-01-01

    Background Negative symptoms of schizophrenia have a severe impact on functional outcomes and treatment options are limited. Arts therapies are currently recommended but more evidence is required. Aims To assess body psychotherapy as a treatment for negative symptoms compared with an active control (trial registration: ISRCTN84216587). Method Schizophrenia out-patients were randomised into a 20-session body psychotherapy or Pilates group. The primary outcome was negative symptoms at end of treatment. Secondary outcomes included psychopathology, functional, social and treatment satisfaction outcomes at treatment end and 6-months later. Results In total, 275 participants were randomised. The adjusted difference in negative symptoms was 0.03 (95% CI −1.11 to 1.17), indicating no benefit from body psychotherapy. Small improvements in expressive deficits and movement disorder symptoms were detected in favour of body psychotherapy. No other outcomes were significantly different. Conclusions Body psychotherapy does not have a clinically relevant beneficial effect in the treatment of patients with negative symptoms of schizophrenia. PMID:27151073

  2. Photoperiod-dependent negative feedback effects of thyroid hormones in Fundulus heteroclitus

    SciTech Connect

    Brown, C.L.; Stetson, M.H.

    1985-05-01

    In Fundulus heteroclitus, an annual cycle in the response of the thyroid to ovine thyroid-stimulating hormone (oTSH) is characterized by maximal thyroxin (T4) secretion in mid-winter and minimal T4 secretion in summer. Four daily injections of oTSH, given in winter caused serum T4 to plateau at elevated levels for several days, while in summer fish similar treatment resulted in far more fluctuating titers of serum T4; maximum levels were similar in both groups. The difference in sustenance rather than magnitude of Peak T4 led to an examination of the negative feedback effects of thyroid hormones as they might relate to these seasonal changes. Radioiodine uptake by thyroid follicles served as a simple, but effective bioassay for endogenous TSH. Fish collected in summer were more sensitive to negative feedback of T3 than those collected in winter; feedback effects of T4 in the two groups were not significantly different. The effects of specific photoperiods on negative feedback sensitivity to T3 and T4 were also tested. Exposure of winter fish for one month to long days (LD 14:10) enhanced the degree of reduction of iodine uptake caused by T4 in the aquarium water (10 micrograms/100 ml). Negative feedback in short-day (LD 8:16) winter fish was not demonstrated. It is concluded that long days increase and short days diminish the negative feedback sensitivity of the hypothalamus-pituitary axis to thyroid hormones in F. heteroclitus. Such photoperiodically induced changes may act to aid in the year-round maintenance of T4 levels necessary for seasonal adaptation and survival.

  3. Analysis of the encoding factors that produce the negative repetition effect.

    PubMed

    Mulligan, Neil W; Peterson, Daniel J

    2014-05-01

    Perhaps the most basic finding in memory research is the repetition effect-the fact 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 across pairs, the target words were drawn from a small set of categories. In the repetition condition, the pairs were initially presented in a random order and then presented a second time blocked by the category of the target words. In the single presentation condition, the pairs were presented only in the blocked order. Participants in the former condition recalled fewer target words on a free recall test despite having seen the word pairs twice (the negative repetition effect). The encoding conditions necessary to produce this effect were examined in 4 experiments. Presenting the repetitions in a single study list elicited the negative repetition effect in free and category-cued recall. However, eliminating the strong within-trial, rhyme relationship eliminated the effect in both tests. Finally, presenting a disorganized but unrelated set of rhyming word pairs as List 1 reduced recall (relative to the single-presentation condition) to the same degree as the repetition condition. The negative repetition effect is due to reduced interitem relational processing during the presentation of the organized list (or half list), a reduction that requires a competing within-target relationship but can be induced by an unrelated as well as identical set of word pairs. PMID:24548323

  4. Aromatase inhibiting and combined estrogenic effects of parabens and estrogenic effects of other additives in cosmetics

    SciTech Connect

    Meeuwen, J.A. van Son, O. van; Piersma, A.H.; Jong, P.C. de; Berg, M. van den

    2008-08-01

    There is concern widely on the increase in human exposure to exogenous (anti)estrogenic compounds. Typical are certain ingredients in cosmetic consumer products such as musks, phthalates and parabens. Monitoring a variety of human samples revealed that these ingredients, including the ones that generally are considered to undergo rapid metabolism, are present at low levels. In this in vitro research individual compounds and combinations of parabens and endogenous estradiol (E{sub 2}) were investigated in the MCF-7 cell proliferation assay. The experimental design applied a concentration addition model (CA). Data were analyzed with the estrogen equivalency (EEQ) and method of isoboles approach. In addition, the catalytic inhibitory properties of parabens on an enzyme involved in a rate limiting step in steroid genesis (aromatase) were studied in human placental microsomes. Our results point to an additive estrogenic effect in a CA model for parabens. In addition, it was found that parabens inhibit aromatase. Noticeably, the effective levels in both our in vitro systems were far higher than the levels detected in human samples. However, estrogenic compounds may contribute in a cumulative way to the circulating estrogen burden. Our calculation for the extra estrogen burden due to exposure to parabens, phthalates and polycyclic musks indicates an insignificant estrogenic load relative to the endogenous or therapeutic estrogen burden.

  5. A subliminal inhibitory mechanism for the negative compatibility effect: a continuous versus threshold mechanism.

    PubMed

    Liu, Peng; Chen, Xuhai; Dai, Dongyang; Wang, Yongchun; Wang, Yonghui

    2014-07-01

    The current study investigated the mechanism underlying subliminal inhibition using the negative compatibility effect (NCE) paradigm. We hypothesized that a decrease in prime activation affects the subsequent inhibitory process, delaying onset of inhibition and reducing its strength. Two experiments tested this hypothesis using arrow stimuli as primes and targets. Two different irrelevant masks (i.e., a mask sharing no prime features) were presented in succession in each trial to not only ensure that primes were processed subliminally, but also avoid feature updating between primes and masks. Prime/target compatibility and prime background density were manipulated in Experiment 1. Results showed that under subliminal inhibitory condition, the NCE disappears when the density increases (i.e., pixel density in the prime's background of 25 %) in Experiment 1. However, when we fixed the prime's background at the density of 25 % and manipulated prime/target compatibility as well as inter-stimuli-interval (ISI) between mask and target in Experiment 2, behavioral results showed marginally significant NCEs in the 150-ms ISI condition. Electrophysiological evidence showed the lateralized readiness potential for compatible trials was significantly more positive than that for incompatible trials during the two consecutive time windows (i.e., 400-450 and 450-500 ms) in the 150-ms ISI condition. In addition, the NCE size was significant smaller in Experiment 2 than in Experiment 1. All of the results support predictions of the continuous subliminal inhibitory mechanism hypothesis which posits that decreases in prime activation strength lead to delay in inhibitory onset and decline in inhibitory strength. PMID:24715101

  6. Nodal expression in triple-negative breast cancer: Cellular effects of its inhibition following doxorubicin treatment.

    PubMed

    Bodenstine, Thomas M; Chandler, Grace S; Reed, David W; Margaryan, Naira V; Gilgur, Alina; Atkinson, Janis; Ahmed, Nida; Hyser, Matthew; Seftor, Elisabeth A; Strizzi, Luigi; Hendrix, Mary J C

    2016-05-01

    Triple-negative breast cancer (TNBC) represents an aggressive cancer subtype characterized by the lack of expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The independence of TNBC from these growth promoting factors eliminates the efficacy of therapies which specifically target them, and limits TNBC patients to traditional systemic neo/adjuvant chemotherapy. To better understand the growth advantage of TNBC - in the absence of ER, PR and HER2, we focused on the embryonic morphogen Nodal (associated with the cancer stem cell phenotype), which is re-expressed in aggressive breast cancers. Most notably, our previous data demonstrated that inhibition of Nodal signaling in breast cancer cells reduces their tumorigenic capacity. Furthermore, inhibiting Nodal in other cancers has resulted in improved effects of chemotherapy, although the mechanisms for this remain unknown. Thus, we hypothesized that targeting Nodal in TNBC cells in combination with conventional chemotherapy may improve efficacy and represent a potential new strategy. Our preliminary data demonstrate that Nodal is highly expressed in TNBC when compared to invasive hormone receptor positive samples. Treatment of Nodal expressing TNBC cell lines with a neutralizing anti-Nodal antibody reduces the viability of cells that had previously survived treatment with the anthracycline doxorubicin. We show that inhibiting Nodal may alter response mechanisms employed by cancer cells undergoing DNA damage. These data suggest that development of therapies which target Nodal in TNBC may lead to additional treatment options in conjunction with chemotherapy regimens - by altering signaling pathways critical to cellular survival. PMID:27007464

  7. Shear-mediated contributions to the effective properties of soft acoustic metamaterials including negative index

    PubMed Central

    Forrester, Derek Michael; Pinfield, Valerie J.

    2015-01-01

    Here we show that, for sub-wavelength particles in a fluid, viscous losses due to shear waves and their influence on neighbouring particles significantly modify the effective acoustic properties, and thereby the conditions at which negative acoustic refraction occurs. Building upon earlier single particle scattering work, we adopt a multiple scattering approach to derive the effective properties (density, bulk modulus, wavenumber). We show,through theoretical prediction, the implications for the design of “soft” (ultrasonic) metamaterials based on locally-resonant sub-wavelength porous rubber particles, through selection of particle size and concentration, and demonstrate tunability of the negative speed zones by modifying the viscosity of the suspending medium. For these lossy materials with complex effective properties, we confirm the use of phase angles to define the backward propagation condition in preference to “single-” and “double-negative” designations. PMID:26686414

  8. Negative effective mass density of acoustic metamaterial plate decorated with low frequency resonant pillars

    NASA Astrophysics Data System (ADS)

    Oudich, Mourad; Djafari-Rouhani, Bahram; Pennec, Yan; Assouar, M. Badreddine; Bonello, Bernard

    2014-11-01

    We investigate the elastic wave dispersion by a phononic metamaterial plate containing low frequency resonator stubs arranged periodically over the plate. We show that this system not only provides stop bands for wavelengths much larger than the periodicity but also displays negative behavior of its effective mass density under the homogenization assumption. A numerical method is used to calculate the plate's effective dynamic mass density as function of the frequency where the metamaterial is considered as homogeneous plate for these large wavelengths. Strong anisotropy of the effective mass density matrix is observed around the resonance frequencies where the gaps are opened. In these regions, we demonstrate that the effective matrix density components take negative values. For each of these components, the negative behavior is studied by taking into account the polarization of the involved resonant modes as well as their associated partial band gaps opened for each specific Lamb symmetry modes. We found that coupling between Lamb waves and resonant modes strongly affects the effective density of the whole plate especially in the coupling frequency regions of the gaps.

  9. [Bioactive effectiveness of selected disinfective agents on Gram-negative bacilli isolated from hospital environment].

    PubMed

    Pancer, Katarzyna W; Laudy, Agnieszka E; Mikulak, Ewa; Gliniewicz, Aleksandra; Staniszewska, Monika; Stypułkowska-Misiurewicz, Hanna

    2004-01-01

    In our study the susceptibility (MIC) of chosen 21 strains of Gram-negative bacilli isolated in hospitals to disinfectant agents (glucoprotamine, sodium dichloroisocyanurate, potassium persulfate), the effectiveness of these disinfectants against selected bacteria and their effectiveness to biofilm forming bacteria was determined. It was found that glucoprotamine showed the highest activity to Gram-negative bacteria. Obtained MIC values for glucoprotamine (except 1 strain of S. marcescens) were 16-64 times lower that MICs for sodium dichloroisocyanurate and 4-32 times lower that MICs for potassium persulfate. The effectiveness of disinfectants containing potassium persulfate or sodium dichloroisocyanurate was 100% tested by carrier method. Glucoprotamine was ineffective against 2 out of 9 strains (18%): E. cloacae and S. marcescens. It was found that disinfectants were more effective against Gram-negative bacteria in carrier methods than for biofilm forming bacteria. 86% of bacteria growing 5 days on a catheter were resistant to working solution of disinfectant containing glucoprotamine (5200 mg/L) or potassium persulfate (4300 mg/L); 66.6% of tested bacteria were resistant to working solution of sodium dichloroisocyanurate (1795.2 mg/L). In our study the highest effectiveness to biofilm forming bacteria showed disinfectant with sodium dichloroisocyanurate, the lowest--with glucoprotamine. PMID:15810507

  10. Asymmetric and Negative Differential Thermal Spin Effect at Magnetic Interfaces: Towards Spin Seebeck Diodes and Transistors

    NASA Astrophysics Data System (ADS)

    Ren, Jie; Zhu, Jian-Xin

    2014-03-01

    We study the nonequilibrium thermal-spin transport across metal-magnetic insulator interfaces. The transport is assisted by the exchange interaction between conduction electrons in the metal and localized spins in the magnetic insulator. We predict the rectification and negative differential spin Seebeck effect (SSE), that is, reversing the temperature bias is able to give asymmetric spin currents and increasing temperature bias could give an anomalously decreasing spin current. We resolve their microscopic mechanism as a consequence of the energy-dependent electronic DOS in the metal. The rectification of spin Peltier effect is also discussed. We then study the asymmetric and negative differential magnon tunneling driven by temperature bias. We show that the many-body magnon interaction that makes the magnonic spectrum temperature-dependent is the crucial factor for the emergence of rectification and negative differential SSEs in magnon tunneling junctions. We show that these asymmetric and negative differential SSEs are relevant for building magnon and spin Seebeck diodes and transistors, which could play important roles in controlling information and energy in functional devices. Supported by the National Nuclear Security Administration of the US DOE at LANL under Contract No. DE-AC52-06NA25396.

  11. Effect of negative pressure on growth, secretion and biofilm formation of Staphylococcus aureus.

    PubMed

    Li, Tongtong; Wang, Guoqi; Yin, Peng; Li, Zhirui; Zhang, Licheng; Liu, Jianheng; Li, Ming; Zhang, Lihai; Han, Li; Tang, Peifu

    2015-10-01

    Negative pressure wound therapy (NPWT) has gained popularity in the management of contaminated wounds as an effective physical therapy, although its influence on the bacteria in the wounds remains unclear. In this study, we attempted to explore the effect of negative pressure conditions on Staphylococcus aureus, the most frequently isolated pathogen during wound infection. S. aureus was cultured in Luria-Bertani medium at subatmospheric pressure of -125 mmHg for 24 h, with the bacteria grown at ambient pressure as the control. The application of negative pressure was found to slow down the growth rate and inhibit biofilm development of S. aureus, which was confirmed by static biofilm assays. Furthermore, decreases in the total amount of virulence factors and biofilm components were observed, including α-hemolysin, extracellular adherence protein, polysaccharide intercellular adhesin and extracellular DNA. With quantitative RT-PCR analysis, we also revealed a significant inhibition in the transcription of virulence and regulatory genes related to wound infections and bacterial biofilms. Together, these findings indicated that negative pressure could inhibit the growth, virulence and biofilm formation of S. aureus. A topical subatmospheric pressure condition, such as NPWT, may be a potential antivirulence and antibiofilm strategy in the field of wound care. PMID:26272011

  12. Negative Priming Effects in Children Engaged in Nonspatial Tasks: Evidence for Early Development of an Intact Inhibitory Mechanism

    ERIC Educational Resources Information Center

    Pritchard, Verena E.; Neumann, Ewald

    2004-01-01

    Three experiments are reported that examined conceptual negative priming effects in children 5 to 12 years of age. Experiment 1 used a negative priming variant of a flanker task requiring the naming of a central color blob flanked by irrelevant distractors. Experiment 2 used a negative priming variant of the Stroop color-word task. Experiment 3…

  13. Negative differential thermal conductance and thermal rectification effects across a graphene-based superconducting junction

    NASA Astrophysics Data System (ADS)

    Zhou, Xingfei; Zhang, Zhi

    2016-05-01

    We study the heat transport in a graphene-based normal-superconducting junction by solving the Bogoliubov-de Gennes (BdG) equation. There are two effects, the competitive and cooperative effects, which come from the interaction between the temperature-dependent energy-gap function in the superconducting region and the occupation difference of quasiparticles. It is found that the competitive effect can not only bring the negative differential thermal conductance effect but also the thermal rectification effect. By contrast, the cooperative effect just causes the thermal rectification effect. Furthermore, the thermal rectification ratio and the magnitude of heat current should be seen as two inseparable signs for characterizing the thermal rectification effect. These discoveries can add more application for the graphene-based superconducting junction, such as heat diode and heat transistor, at cryogenic temperatures.

  14. Contribution of temperament to eating disorder symptoms in emerging adulthood: Additive and interactive effects.

    PubMed

    Burt, Nicole M; Boddy, Lauren E; Bridgett, David J

    2015-08-01

    Temperament characteristics, such as higher negative emotionality (NE) and lower effortful control (EC), are individual difference risk factors for developmental psychopathology. Research has also noted relations between temperament and more specific manifestations of psychopathology, such as eating disorders (EDs). Although work is emerging that indicates that NE and EC may additively contribute to risk for ED symptoms, no studies have considered the interactive effects of NE and EC in relation to ED symptoms. In the current investigation, we hypothesized that (1) low EC would be associated with increased ED symptoms, (2) high NE would be associated with increased ED symptoms, and (3) these temperament traits would interact, such that the relationship between NE and ED symptoms would be strongest in the presence of low EC. After controlling for gender and child trauma history, emerging adults' (N=160) lower EC (i.e., more difficulties with self-regulation) was associated with more ED symptoms. NE did not emerge as a direct predictor of ED symptoms. However, the anticipated interaction of these temperament characteristics on ED symptoms was found. The association between NE and ED symptoms was only significant in the context of low EC. These findings provide evidence that elevated NE may only be a risk factor for the development of eating disorders when individuals also have self-regulation difficulties. The implications of these findings for research and interventions are discussed. PMID:25875113

  15. The effects of negative air ions on various physiological functions during work in a hot environment

    NASA Astrophysics Data System (ADS)

    Inbar, O.; Rotstein, A.; Dlin, R.; Dotan, R.; Sulman, F. G.

    1982-06-01

    The effects of negative air-ions on human physical performance has been investigated. Twenty-one healthy males, 20 25 years old (X=23.6±2.6) were exposed to two 180-min rest and exercise sessions two weeks apart. The subjects were randomly assigned into either an experimental group (n=12) or to a control group (n=9). The experimental group performed the first session in neutral air conditions and the second one in air containing 1.36 to 1.90×105 negative air ions and 1.40 to 1.66×102 positive air ions/ml. The control group performed both sessions under neutral air conditions. All sessions were held at Ta=40±1‡C and 25±5% RH. Each session included one hour of resting under the respective ionization conditions, followed by 3 30-min cycle ergometer work bouts, separated by 7-min rest periods. The mechanical work-load during the bicycle exercise was 1.64±0.6 W/kg BW. The experimental group showed a significant reduction with negative air-ions in heart rate (HR), in rectal temperature, and in the rating of perceived exertion (RPE), all when compared with their own neutral session. The control group showed no significant changes between the first and the second exposure. Although not statistically significant, being exposed to negative air-ions seems also to reduce total sweat rate and minute ventilation (VE), and to increase O2 pulse. It is suggested that under the conditions of this study negative air ions can improve various cardiovascular and thermoregulatory functions as well as subjective feelings during physical effort. It is felt that such positive influences may be augmented by increasing the exposure time to negative ionized air and/or prolonging the stressful conditions.

  16. Chemopreventive effects of Ginkgo biloba extract in estrogen-negative human breast cancer cells.

    PubMed

    Park, Yong Joo; Kim, Mi Jie; Kim, Ha Ryong; Yi, Min Sun; Chung, Kyu Hyuck; Oh, Seung Min

    2013-01-01

    Excessive level of estrogen is considered as a main cause of breast cancer, therefore, many studies have focused on estrogen receptor (ER)-positive breast cancer, even though ER-negative cancer has a poor prognosis than ER-positive breast cancer. We evaluated the anti-cancer effects of Ginkgo biloba extract (GBE) in estrogen-independent breast cancer. GBE has been traditionally used as a platelet activating factor, a circulatory stimulant, a tonic, and anti-asthmatic drug, and anti-cancer agent. However, anti-cancer effects of GBE on ER-negative breast cancer have not been proved yet. In this study, we tested chemotherapeutic potential of GBE in the MDA-MB-231 (ER-negative) human breast cancer cell line. Our results showed that cytotoxicity effects of GBE in MDA-MB-231 lead to DNA fragmentation at high concentrations (500 and 1,000 μg/ml). Caspase-3 was significantly activated and mRNA levels of apoptosis-related genes (Bcl-2 and Bax) were altered. These results indicate that GBE induces apoptosis in MDA-MB-231 cells. It is presumed that GBE has chemopreventive effects in ER-independent breast cancer through anti-proliferation and apoptosis-inducing activities. PMID:23335025

  17. Effects of negative pions and neutrons on the growth of Vicia faba bean roots.

    PubMed

    Bianchi, M; Hill, D K; Baarli, J; Sullivan, A H

    1978-02-01

    Vicia faba bean roots have been irratiated with neutrons of various energies and with negative pi-mesons, and the effect on the ten-day growth of the roots has been determened. The neutron irratiations were made in beams of 400 and 600 MeV maximum energy, as well as with neutrons from a plutonium-beryllium source (mean energy 4.4 MeV) and from a 14 MeV neutron generator. The bean roots have also been irradiated at various points along the depth-dose curve of negative pi-mesons, including the gegion where the pions annihilate on coming to rest. The results show a maximum relative biological effectiveness (RBE) of 3.7 for 50% reduction in ten days growth for stopped negative pions and values up to 3.3 for high-energy neutrons, compared to 5.5 for 14 MeV neutrons. The biological effectiveness of high-energy neutrons and stopped pions shows a more pronounced dependence on dose than does the effect with lower-energy neutrons. PMID:626812

  18. Effect of electrolyte addition to rehydration drinks consumed after severe fluid and energy restriction.

    PubMed

    James, Lewis J; Shirreffs, Susan M

    2015-02-01

    This study examined the effect of electrolyte addition to drinks ingested after severe fluid and energy restriction (FER). Twelve subjects (6 male and 6 female) completed 3 trials consisting of 24-hour FER (energy intake: 21 kJ·kg body mass; water intake: 5 ml·kg body mass), followed by a 2-hour rehydration period and a 4-hour monitoring period. During rehydration, subjects ingested a volume of drink equal to 125% of the body mass lost during FER in 6 aliquots, once every 20 minutes. Drinks were a sugar-free lemon squash (P) or the P drink with the addition of 50 mmol·L sodium chloride (Na) or 30 mmol·L potassium chloride (K). Total void urine samples were given before and after FER and every hour during rehydration and monitoring. Over all trials, FER produced a 2.1% reduction in body mass and negative sodium (-67 mmol), potassium (-48 mmol), and chloride (-84 mmol) balances. Urine output after drinking was 1627 (540) ml (P), 1391 (388) ml (K), and 1150 (438) ml (Na), with a greater postdrinking urine output during P than Na (p ≤ 0.05). Ingestion of drink Na resulted in a more positive sodium balance compared with P or K (p < 0.001), whereas ingestion of drink K resulted in a more positive potassium balance compared with P or Na (p < 0.001). These results demonstrate that after 24-hour FER, ingestion of a high sodium drink results in an increased sodium balance that augments greater drink retention compared with a low electrolyte placebo drink. PMID:25162651

  19. Heat diode effect and negative differential thermal conductance across nanoscale metal-dielectric interfaces

    NASA Astrophysics Data System (ADS)

    Ren, Jie; Zhu, Jian-Xin

    2013-06-01

    Controlling heat flow by phononic nanodevices has received significant attention recently because of its fundamental and practical implications. Elementary phononic devices such as thermal rectifiers, transistors, and logic gates are essentially based on two intriguing properties: heat diode effect and negative differential thermal conductance. However, little is known about these heat transfer properties across metal-dielectric interfaces, especially at nanoscale. Here we analytically resolve the microscopic mechanism of the nonequilibrium nanoscale energy transfer across metal-dielectric interfaces, where the inelastic electron-phonon scattering directly assists the energy exchange. We demonstrate the emergence of heat diode effect and negative differential thermal conductance in nanoscale interfaces and explain why these novel thermal properties are usually absent in bulk metal-dielectric interfaces. These results will generate exciting prospects for the nanoscale interfacial energy transfer, which should have important implications in designing hybrid circuits for efficient thermal control and open up potential applications in thermal energy harvesting with low-dimensional nanodevices.

  20. Interrogative pressure in simulated forensic interviews: the effects of negative feedback.

    PubMed

    McGroarty, Allan; Baxter, James S

    2007-08-01

    Much experimental research on interrogative pressure has concentrated on the effects of leading questions, and the role of feedback in influencing responses in the absence of leading questions has been neglected by comparison. This study assessed the effect of negative feedback and the presence of a second interviewer on interviewee responding in simulated forensic interviews. Participants viewed a videotape of a crime, answered questions about the clip and were requestioned after receiving feedback. Compared with neutral feedback, negative feedback resulted in more response changes, higher reported state anxiety and higher ratings of interview difficulty. These results are consistent with Gudjonsson and Clark's (1986) model of interrogative suggestibility. The presence and involvement of a second interviewer did not significantly affect interviewee responding, although trait anxiety scores were elevated when a second interviewer was present. The theoretical and applied implications of these findings are considered. PMID:17535467

  1. The importance of negative defensive medicine in the effects of malpractice reform.

    PubMed

    Montanera, Daniel

    2016-04-01

    This article presents a model of physician and insurer behavior in which the practice of defensive medicine, both positive and negative, can arise. Accounting for negative defensive medicine, and insurers' reaction to it, leads to different predictions of the effects of changing malpractice pressure compared to past models. Rising malpractice pressure causes both health care spending and quality to increase up to a threshold, and decrease thereafter. This non-monotonicity implies that malpractice reform is not a "silver bullet" capable of achieving both cost reductions and quality improvements for all consumers. The results can further explain inconsistent findings in the empirical literature and suggest alternative specifications for estimating the effects of malpractice reform. PMID:25855557

  2. Positive and negative effects of grass, cattle, and wild herbivores on Acacia saplings in an East African savanna.

    PubMed

    Riginos, Corinna; Young, Truman P

    2007-10-01

    Plant-plant interactions can be a complex mixture of positive and negative interactions, with the net outcome depending on abiotic and community contexts. In savanna systems, the effects of large herbivores on tree-grass interactions have rarely been studied experimentally, though these herbivores are major players in these systems. In African savannas, trees often become more abundant under heavy cattle grazing but less abundant in wildlife preserves. Woody encroachment where cattle have replaced wild herbivores may be caused by a shift in the competitive balance between trees and grasses. Here we report the results of an experiment designed to quantify the positive, negative, and net effects of grasses, wild herbivores, and cattle on Acacia saplings in a Kenyan savanna. Acacia drepanolobium saplings under four long-term herbivore regimes (wild herbivores, cattle, cattle + wild herbivores, and no large herbivores) were cleared of surrounding grass or left with the surrounding grass intact. After two years, grass-removal saplings exhibited 86% more browse damage than control saplings, suggesting that grass benefited saplings by protecting them from herbivory. However, the negative effect of grass on saplings was far greater; grass-removal trees accrued more than twice the total stem length of control trees. Where wild herbivores were present, saplings were browsed more and produced more new stem growth. Thus, the net effect of wild herbivores was positive, possibly due to the indirect effects of lower competitor tree density in areas accessible to elephants. Additionally, colonization of saplings by symbiotic ants tracked growth patterns, and colonized saplings experienced lower rates of browse damage. These results suggest that savanna tree growth and woody encroachment cannot be predicted by grass cover or herbivore type alone. Rather, tree growth appears to depend on a variety of factors that may be acting together or antagonistically at different stages of the

  3. The Effect of Positive and Negative Feedback on Risk-Taking across Different Contexts

    PubMed Central

    Losecaat Vermeer, Annabel B.; Sanfey, Alan G.

    2015-01-01

    Preferences for risky choices have often been shown to be unstable and context-dependent. Though people generally avoid gambles with mixed outcomes, a phenomenon often attributed to loss aversion, contextual factors can impact this dramatically. For example, people typically prefer risky options after a financial loss, while generally choosing safer options after a monetary gain. However, it is unclear what exactly contributes to these preference shifts as a function of prior outcomes, as these gain/loss outcomes are usually confounded with participant performance, and therefore it is unclear whether these effects are driven purely by the monetary gains or losses, or rather by success or failure at the actual task. Here, we experimentally separated the effects of monetary gains/losses from performance success/failure prior to a standard risky choice. Participants performed a task in which they experienced contextual effects: 1) monetary gain or loss based directly on performance, 2) monetary gain or loss that was randomly awarded and was, crucially, independent from performance, and 3) success or failure feedback based on performance, but without any monetary incentive. Immediately following these positive/negative contexts, participants were presented with a gain-loss gamble that they had to decide to either play or pass. We found that risk preferences for identical sets of gambles were biased by positive and negative contexts containing monetary gains and losses, but not by contexts containing performance feedback. This data suggests that the observed framing effects are driven by aversion for monetary losses and not simply by the positive or negative valence of the context, or by potential moods resulting from positive or negative contexts. These results highlight the specific context dependence of risk preferences. PMID:26407298

  4. Are the Negative Effects of Divorce on Well-Being Dependent on Marital Quality?

    ERIC Educational Resources Information Center

    Kalmijn, Matthijs; Monden, Christiaan W. S.

    2006-01-01

    We test the so-called escape hypothesis, which argues that for people from a poor marriage, a divorce has a less negative or even a positive effect on well-being. In an analysis of two waves of the National Survey of Families and Households (N = 4,526), we find only limited evidence. When people divorce from a dissatisfactory or unfair marriage,…

  5. Negative Affect Mediates Effects of Psychological Stress on Disordered Eating in Young Chinese Women

    PubMed Central

    Chen, Jue; Wang, Zhen; Guo, Boliang; Arcelus, Jon; Zhang, Haiyin; Jia, Xiuzhen; Xu, Yong; Qiu, Jianyin; Xiao, Zeping; Yang, Min

    2012-01-01

    Background The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women. Methodology A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10), Beck Depression Inventory Revised (BDI-II), Beck Anxiety Inventory (BAI), and Eating Attitude Test (EAT-26) were administered to all participants. Principal Findings The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (–0.012, 95%CI: –.038∼0.006, p = 0.357), however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022∼0.044, p<0.001) and 0.015 (95%CI: 0.005∼0.023, p<0.01), respectively. Conclusions Perceived stress and negative affects of depression and anxiety were demonstrated to be strongly associated with disordered eating. Negative affect mediated the relationship between perceived stress and disordered eating. The findings suggest that effective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population. PMID:23071655

  6. Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma

    SciTech Connect

    Barman, Arnab; Misra, A. P. E-mail: apmisra@gmail.com

    2014-07-15

    The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (μ{sub pd}) as well as the ratios of positive to negative ion temperatures (σ) and masses (m)

  7. Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma

    NASA Astrophysics Data System (ADS)

    Barman, Arnab; Misra, A. P.

    2014-07-01

    The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (μpd) as well as the ratios of positive to negative ion temperatures (σ) and masses (m).

  8. Negative effects of nicotine on bone-resorbing cytokines and bone histomorphometric parameters in male rats.

    PubMed

    Hapidin, Hermizi; Othman, Faizah; Soelaiman, Ima-Nirwana; Shuid, Ahmad N; Luke, Douglas A; Mohamed, Norazlina

    2007-01-01

    The effects of nicotine administration on bone-resorbing cytokines, cotinine, and bone histomorphometric parameters were studied in 21 Sprague-Dawley male rats. Rats aged 3 months and weighing 250-300 g were divided into three groups. Group 1 was the baseline control (BC), which was killed without treatment. The other two groups were the control group (C) and the nicotine-treated group (N). The N group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection for 6 days/week for 4 months. The rats were injected intraperitoneally with calcein 20 mg/kg body weight at day 9 and day 2 before they were killed. ELISA test kits were used to measure the serum interleukin-1 (IL-1), interleukin-6 (IL-6), and cotinine (a metabolite of nicotine) levels at the beginning of the study and upon completion of the study. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis revealed that nicotine treatment for 4 months significantly increased the serum IL-1, IL-6, and cotinine levels as compared to pretreatment levels. In addition, the serum cotinine level was significantly higher in the N group than in the C group after 4 months treatment. Histomorphometric analysis showed that nicotine significantly decreased the trabecular bone volume (BV/TV), trabecular thickness (Tb.Th), double-labeled surface (dLS/BS), mineralizing surface (MS/BS), mineral appositional rate (MAR), and bone formation rate (BFR/BS), while causing an increase in the single-labeled surface (sLS/BS), osteoclast surface (Oc.S/BS), and eroded surface (ES/BS) as compared to the BC and C groups. In conclusion, treatment with nicotine 7 mg/kg for 4 months was detrimental to bone by causing an increase in the bone resorbing cytokines and cotinine levels. Nicotine also exerted negative effects on the dynamic trabecular histomorphometric

  9. Effect of flame-retarding additives on surface chemistry in Li-ion batteries

    SciTech Connect

    Nam, N.D.; Park, I.J.; Kim, J.G.; Kim, H.S.

    2012-10-15

    This study examined the properties of 1 wt.% vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and diphenyl octyl phosphate (DPOF) additive electrolytes as a promising way of beneficially improving the surface and cell resistance of Li-ion batteries. Surface film formation on the negative and positive electrodes was analyzed by electrochemical impedance spectroscopy (EIS), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). In conclusion, EIS, FT-IR spectroscopy and SEM results confirmed that DPOF is an excellent additive to the electrolyte in the Li-ion batteries due to the improved co-intercalation of the solvent molecules.

  10. The effect of alternative testing strategies and bio-exclusion practices on Johne's disease risk in test-negative herds.

    PubMed

    More, S J; Sergeant, E S G; Strain, S; Cashman, W; Kenny, Kevin; Graham, D

    2013-03-01

    Herd classification is a key component of national Johne's disease (JD) control programs. Herds are categorized on the basis of test results, and separate sub-programs are followed for test-positive and test-negative herds. However, a test-negative herd result does not necessarily equate to JD freedom for reasons relating to disease pathogenesis and available diagnostic tests. Thus, in several countries, JD control programs define test-negative herds as having a "low risk" of infection below a specified prevalence. However, the approach is qualitative, and little quantitative work is available on herd-level estimates of probability of freedom in test-negative herds. This paper examines the effect over time of alternative testing strategies and bio-exclusion practices on JD risk in test-negative herds. A simulation model was developed in the programming language R. Key model inputs included sensitivity and specificity estimates for 3 individual animal diagnostic tests (serum ELISA, milk ELISA, and fecal culture), design prevalence, testing options, and testing costs. Key model outputs included the probability that infection will be detected if present at the design prevalence or greater (herd sensitivity; SeH), the probability that infection in the herd is either absent or at very low prevalence (i.e., less than the design prevalence; ProbF), the probability of an uninfected herd producing a false-positive result [P(False+)], and mean testing cost (HerdCost) for different testing strategies. The output ProbF can be updated periodically, incorporating data from additional herd testing and information on cattle purchases, and could form the basis for an output-based approach to herd classification. A high ProbF is very difficult to achieve, reflecting the low sensitivity of the evaluated tests. Moreover, ProbF is greatly affected by any risk of introduction of infection, decreasing in herds with poor bio-exclusion practices despite ongoing negative test results. The

  11. Negative and interactive effects of sex, aging, and alcohol abuse on gray matter morphometry.

    PubMed

    Thayer, Rachel E; Hagerty, Sarah L; Sabbineni, Amithrupa; Claus, Eric D; Hutchison, Kent E; Weiland, Barbara J

    2016-06-01

    Chronic alcohol use is associated with declines in gray matter (GM) volume, as is the normal aging process. Less apparent, however, is how the interaction between aging and heavy alcohol use affects changes in GM across the lifespan. There is some evidence that women are more vulnerable to the negative effects of alcohol use on GM than men. In the current study, we examined whether localized GM was related to measures of alcohol use disorder (e.g., AUDIT score) in a large sample (N = 436) of participants, ages 18-55 years, with a range of disease severity, using both voxel-based morphometry (VBM) and surface-based morphometry (SBM). We also explored whether GM associations with alcohol use disorder (AUD) severity are moderated by sex and age. Results showed significant negative associations between AUD severity and GM volume throughout temporal, parietal, frontal, and occipital lobes. Women showed more negative effects of alcohol use than men for cortical thickness in left orbitofrontal cortex, but evidence for increased vulnerability based on sex was limited overall. Similarly, a specific age by alcohol use interaction was observed for volume of right insula, but other regional or global interactions were not statistically supported. However, significant negative associations between heavy alcohol use and GM volumes were observed as early as 18-25 years. These findings support that alcohol has deleterious effects on global and regional GM above and beyond age, and, of particular importance, that regional associations emerge in early adulthood. Hum Brain Mapp 37:2276-2292, 2016. © 2016 Wiley Periodicals, Inc. PMID:26947584

  12. The effect of silane addition timing on mixing processability and properties of silica reinforced rubber compound

    NASA Astrophysics Data System (ADS)

    Jeong, Hee-Hoon; Jin, Hyun-Ho; Ha, Sung-Ho; Jang, Suk-Hee; Kang, Yong-Gu; Han, Min-Hyun

    2016-03-01

    A series of experiments were performed to determine an optimum balance between processability and performance of a highly loaded silica compound. The experiments evaluated 4 different silane injection times. All mixing related to silane addition was conducted with a scaled up "Tandem" mixer line. With exception to silane addition timing, almost all operating conditions were controlled between experimental features. It was found that when the silane addition was introduced earlier in the mixing cycle both the reaction was more complete and the bound rubber content was higher. But processability indicators such as sheet forming and Mooney plasticity were negatively impacted. On the other hand, as silane injection was delayed to later in the mixing process the filler dispersion and good sheet forming was improved. However both the bound rubber content and Silane reaction completion were decreased. With the changes in silane addition time, the processability and properties of a silica compound can be controlled.

  13. Effects of Experimental Negative Affect Manipulations on Ad Lib Smoking: A Meta-Analysis

    PubMed Central

    Heckman, Bryan W.; Carpenter, Mathew J.; Correa, John B.; Wray, Jennifer M.; Saladin, Michael E.; Froeliger, Brett; Drobes, David J.; Brandon, Thomas H.

    2015-01-01

    Aims To quantify the effect of negative affect (NA), when manipulated experimentally, upon smoking as measured within laboratory paradigms. Quantitative meta-analyses tested the effects of NA vs. neutral conditions on 1) latency to smoke and 2) number of puffs taken. Methods Twelve experimental studies tested the influence of NA induction, relative to a neutral control condition (N = 1,190; range = 24–235). Those providing relevant data contributed to separate random effects meta-analyses to examine the effects of NA on two primary smoking measures: 1) latency to smoke (nine studies) and 2) number of puffs taken during ad lib smoking (eleven studies). Hedge’s g was calculated for all studies through the use of post-NA cue responses relative to post-neutral cue responses. This effect size estimate is similar to Cohen’s d, but corrects for small sample size bias. Results NA reliably decreased latency to smoke (g = −.14; CI = −.23 to −.04; p = .007) and increased number of puffs taken (g = .14; CI = .02 to .25; p = .02). There was considerable variability across studies for both outcomes (I2 = 51% and 65% for latency and consumption, respectively). Potential publication bias was indicated for both outcomes, and adjusted effect sizes were smaller and no longer statistically significant. Conclusions In experimental laboratory studies of smokers, negative affect appears to reduce latency to smoking and increase number of puffs taken but this could be due to publication bias. PMID:25641624

  14. Simulation of electrical characteristics in negative capacitance surrounding-gate ferroelectric field-effect transistors

    NASA Astrophysics Data System (ADS)

    Xiao, Y. G.; Chen, Z. J.; Tang, M. H.; Tang, Z. H.; Yan, S. A.; Li, J. C.; Gu, X. C.; Zhou, Y. C.; Ouyang, X. P.

    2012-12-01

    The electrical characteristics of surrounding-gate (SG) metal-ferroelectric-semiconductor (MFS) field-effect transistors (FETs) were theoretically investigated by considering the ferroelectric negative capacitance (NC) effect. The derived results demonstrated that the NC-SG-MFS-FET displays superior electrical properties compared with that of the traditional SG-MIS-FET, in terms of better electrostatic control of the gate electrode over the channel, smaller subthreshold swing (S < 60 mV/dec), and bigger value of ION. It is expected that this investigation may provide some insight into the design and performance improvement for the fast switching and low power dissipation applications of ferroelectric FETs.

  15. The devil is in the specificity: the negative effect of prediction specificity on prediction accuracy.

    PubMed

    Yoon, Song-Oh; Suk, Kwanho; Goo, Jin Kyung; Lee, Jiheon; Lee, Seon Min

    2013-07-01

    In the research reported here, we proposed and demonstrated the prediction-specificity effect, which states that people's prediction of the general outcome of an event (e.g., the winner of a soccer match) is less accurate when the prediction question is framed in a more specific manner (e.g., guessing the score) rather than in a less specific manner (e.g., guessing the winner). We demonstrated this effect by examining people's predictions on actual sports games both in field and laboratory studies. In Study 1, the analysis of 19 billion bets from a commercial sports-betting business provided evidence for the effect of prediction specificity. This effect was replicated in three controlled laboratory studies, in which participants predicted the outcomes of a series of soccer matches. Furthermore, the negative effect of prediction specificity was mediated by participants' underweighting of important holistic information during decision making. PMID:23660410

  16. Effectiveness of caudal epidural injections in discogram positive and negative chronic low back pain.

    PubMed

    Manchikanti, Laxmaiah; Singh, Vijay; Rivera, Jose J; Pampati, Vidyasagar; Beyer, Carla; Damron, Kim; Barnhill, Renee C

    2002-01-01

    Epidural steroid injections are the most commonly used procedures to manage chronic low back pain in interventional pain management settings. The overall effectiveness of epidural steroid injections has been highly variable, and in the role has not been evaluated in patients discographically evaluated. One hundred consecutive patients, without evidence of disc herniation or radiculitis, who had failed to respond to conservative management with physical therapy, chiropractic and/or medical therapy, underwent discography utilizing strict criteria of concordant pain, and negative adjacent discs, after being judged to be negative for facet joint and/or sacroiliac joint pain utilizing comparative local anesthetic blocks. Any other type of response was considered negative. This study included 62 patients, who underwent caudal epidural steroid injections with Sarapin. They included Group I, comprised of 45 of 55 patients negative on provocative discography; and Group II, with 17 of 45 patients with positive provocative discography. Results showed that there was significant improvement in patients receiving caudal epidural injections, with a decrease in pain associated with improved physical, functional, and mental status; decreased narcotic intake, and increased return to work. The study showed that at 1 month, 100% of the patients evaluated showed significant improvement in both groups; this declined to 86% at 3 months in Group I, but remained at 100% in Group II, declining to 60% and 64% at 6 months in Group I and Group II, respectfully, with administration of one to three injections. Analysis with one to three injections, which included all (62) patients showed significant relief in 71% and 65% of the patients at 1 month, in 67% and 65% at 3 months, and in 47% and 41% at 6 months, in Group I and Group II, respectively. In conclusion, caudal epidural injections with or without steroids is an effective modality of treatment in managing chronic, persistent low back pain

  17. Soldered Contact and Current Risetime Effects on Negative Polarity Wire Array Z-pinches

    SciTech Connect

    Chalenski, D. A.; Kusse, B. R.; Greenly, J. B.; Blesener, I. C.; McBride, R. D.; Hammer, D. A.; Knapp, P. F.

    2009-01-21

    The Cornell University COBRA pulser is a nominal 1 MA machine, capable of driving up to 32 wire cylindrical Z-pinch arrays. COBRA can operate with variable current risetimes ranging from 100 ns to 200 ns (short and long pulse, respectively). Wires are typically strung with a 'press' contact to the electrode hardware, where the wire is loosely pulled against the hardware and held there to establish electrical contact. The machine is normally negative, but a bolt-on convolute can be used to modify the current path and effectively produce positive polarity operation at the load.Previous research with single wires on a 1-5 kA pulser has shown that soldering the wire, thereby improving the wire/electrode contact, and operating in positive polarity can improve the energy deposition into the wire and enhance wire core expansion. Negative polarity showed no difference. Previous experiments on the negative polarity, 20 MA, 100 ns Z accelerator have shown that improving the contact improved the x-ray yield.Cornell data were collected on 16-wire Aluminum Z-pinch arrays in negative polarity. Experiments were conducted with both short and long current pulses with soldered and no-soldered wire/electrode contacts. The initiation, ablation, implosion and stagnation phases were compared for these four conditions. Time dependent x-ray signals were measured using diodes and diamond detectors. An inductive voltage monitor was used to infer minimum current radius achieved, as defined by a uniform shell of current moving radially inward, producing a time dependent inductance. Total energy data were collected with a metal-strip bolometer. Self-emission data were collected by an XUV 4-frame camera and an optical streak camera.In negative polarity and with short pulses, soldering appeared to produce a smaller radius pinch and decrease variations in the x-ray pulse shape. The bolometer, laser backlighter, 4-frame and streak cameras showed negligible differences in the initiation ablation

  18. "Effective" negative surface tension: a property of coated nanoaerosols relevant to the atmosphere.

    PubMed

    Chakraborty, Purnendu; Zachariah, Michael R

    2007-06-28

    Atmospheric aerosols play a very important role in atmospheric processes and have a major influence on the global climate. In this paper, we report results of a molecular dynamics study on the unique properties of organic-coated water droplets. In particular, we find that, for particles preferring an inverted micelle structure, the lower chain-chain interaction, with increasing radial distance from the water-organic interface, results in a negative internal radial pressure profile for the organic layer. As a result, a coated particle behaves as though the surface tension is "negative" and implies that such a particle will inherently have an inverse Kelvin vapor pressure effect, resulting in increased water condensation. PMID:17539611

  19. Combined effects of positive and negative affectivity and job satisfaction on job performance and turnover intentions.

    PubMed

    Bouckenooghe, Dave; Raja, Usman; Butt, Arif Nazir

    2013-01-01

    Capturing data from employee-supervisor dyads (N = 321) from eight organizations in Pakistan, including human service organizations, an electronics assembly plant, a packaging material manufacturing company, and a small food processing plant, we used moderated regression analysis to examine whether the relationships between trait affect (positive affectivity [PA] and negative affectivity [NA]) and two key work outcome variables (job performance and turnover) are contingent upon the level of job satisfaction. We applied the Trait Activation Theory to explain the moderating effect of job satisfaction on the relationship between affect and performance and between affect and turnover. Overall, the data supported our hypotheses. Positive and negative affectivity influenced performance and the intention to quit, and job satisfaction moderated these relationships. We discuss in detail the results of these findings and their implications for research and practice. PMID:23469474

  20. The Big-Fish-Little-Pond Effect: Persistent Negative Effects of Selective High Schools on Self-Concept after Graduation

    ERIC Educational Resources Information Center

    Marsh, Herbert W.; Trautwein, Ulrich; Ludtke, Oliver; Baumert, Jurgen; Koller, Olaf

    2007-01-01

    According to the big-fish-little-pond effect (BFLPE), attending academically selective high schools negatively affects academic self-concept. Does the BFLPE persist after graduation from high school? In two large, representative samples of German high school students (Study 1: 2,306 students, 147 schools; Study 2: 1,758 students, 94 schools), the…

  1. The effect of positive and negative verbal feedback on surgical skills performance and motivation.

    PubMed

    Kannappan, Aarthy; Yip, Dana T; Lodhia, Nayna A; Morton, John; Lau, James N

    2012-01-01

    There is considerable effort and time invested in providing feedback to medical students and residents during their time in training. However, little effort has been made to measure the effects of positive and negative verbal feedback on skills performance and motivation to learn and practice. To probe these questions, first-year medical students (n = 25) were recruited to perform a peg transfer task on Fundamentals of Laparoscopic Surgery box trainers. Time to completion and number of errors were recorded. The students were then randomized to receive either positive or negative verbal feedback from an expert in the field of laparoscopic surgery. After this delivery of feedback, the students repeated the peg transfer task. Differences in performance pre- and post-feedback and also between the groups who received positive feedback (PF) vs negative feedback (NF) were analyzed. A survey was then completed by all the participants. Baseline task times were similar between groups (PF 209.3 seconds; NF 203 seconds, p = 0.58). The PF group averaged 1.83 first-time errors while the NF group 1 (p = 0.84). Post-feedback task times were significantly decreased for both groups (PF 159.75 seconds, p = 0.05; NF 132.08 seconds, p = 0.002). While the NF group demonstrated a greater improvement in mean time than the PF group, this was not statistically significant. Both groups also made fewer errors (PF 0.33 errors, p = 0.04; NF 0.38 errors, p = 0.23). When surveyed about their responses to standardized feedback scenarios, the students stated that both positive and negative verbal feedback could be potent stimulants for improved performance and motivation. Further research is required to better understand the effects of feedback on learner motivation and the interpersonal dynamic between mentors and their trainees. PMID:23111049

  2. Effects of litter addition on ectomycorrhizal associates of a lodgepole pine (Pinus contorta) stand in Yellowstone National Park

    NASA Technical Reports Server (NTRS)

    Cullings, Kenneth W.; New, Michael H.; Makhija, Shilpa; Parker, V. Thomas

    2003-01-01

    Increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (EM) communities by inhibiting fungal growth. In this study, we used molecular genetic methods to determine the effects of litter addition on the EM community of a Pinus contorta stand in Yellowstone National Park that regenerated after a stand-replacing fire. Two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chemically neutral substance, was added to maintain soil moisture and temperature at levels similar to those under litter. We found that (i) species richness did not change significantly following perlite addition (2.6 +/- 0.3 species/core in control plots, compared with 2.3 +/- 0.3 species/core in perlite plots) but decreased significantly (P < 0.05) following litter addition (1.8 +/- 0.3 species/core); (ii) EM infection was not affected by the addition of perlite but increased significantly (P < 0.001) in response to litter addition, and the increase occurred only in the upper soil layer, directly adjacent to the added litter; and (iii) Suillus granulatus, Wilcoxina mikolae, and agaricoid DD were the dominant organisms in controls, but the levels of W. mikolae and agaricoid DD decreased significantly in response to both perlite and litter addition. The relative levels of S. granulatus and a fourth fungus, Cortinariaceae species 2, increased significantly (P < 0.01 and P < 0.05, respectively) following litter addition. Thus, litter addition resulted in some negative effects that may be attributable to moisture-temperature relationships rather than to the increased nutrients associated with litter. Some species respond positively to litter addition, indicating that there are differences in their physiologies. Hence, changes in the EM community induced by litter accumulation also may affect ecosystem function.

  3. Additive Effects of Word Frequency and Stimulus Quality: The Influence of Trial History and Data Transformations

    ERIC Educational Resources Information Center

    Balota, David A.; Aschenbrenner, Andrew J.; Yap, Melvin J.

    2013-01-01

    A counterintuitive and theoretically important pattern of results in the visual word recognition literature is that both word frequency and stimulus quality produce large but additive effects in lexical decision performance. The additive nature of these effects has recently been called into question by Masson and Kliegl (in press), who used linear…

  4. Modulation of Additive and Interactive Effects in Lexical Decision by Trial History

    ERIC Educational Resources Information Center

    Masson, Michael E. J.; Kliegl, Reinhold

    2013-01-01

    Additive and interactive effects of word frequency, stimulus quality, and semantic priming have been used to test theoretical claims about the cognitive architecture of word-reading processes. Additive effects among these factors have been taken as evidence for discrete-stage models of word reading. We present evidence from linear mixed-model…

  5. The Additional-Mass Effect of Plates as Determined by Experiments

    NASA Technical Reports Server (NTRS)

    Gracey, William

    1941-01-01

    The apparent increase in the inertia properties of a body moving in a fluid medium has been called the additional-mass effect. This report presents a resume of test procedures and results of experimental determinations of the additional-mass effect of flat plates. In addition to data obtained from various foreign sources and from a NACA investigation in 1933, the results of tests recently conducted by the National Advisory Committee for Aeronautics are included.

  6. Perceived entitativity and the black-sheep effect: when will we denigrate negative ingroup members?

    PubMed

    Lewis, Amy C; Sherman, Steven J

    2010-01-01

    Although ingroup favoritism is a robust effect, there are notable exceptions. For example, the outgroup extremity effect indicates outgroup derogation, whereas the black-sheep effect indicates ingroup derogation. We propose that perceived entitativity, the degree to which a group is viewed as a unified social entity, may help explain ingroup derogation. Negative ingroup members from high perceived entitativity groups may pose a meaningful threat to the perceiver's social identity that can be alleviated by denigrating the target (i.e., the black-sheep effect). Participants evaluated high or low quality essays attributed to ingroup and outgroup members. Participants did not differentiate based on ingroup/outgroup membership for low perceived entitativity groups. However, when rating high perceived entitativity groups, ingroup extremity emerged. These results confirm and provide explanations for ingroup denigration. PMID:20397595

  7. The effect of additives on charge decay in electron-beam charged polypropylene films

    NASA Astrophysics Data System (ADS)

    Hillenbrand, J; Motz, T; Sessler, G M; Zhang, X; Behrendt, N; von Salis-Soglio, C; Erhard, D P; Altstädt, V; Schmidt, H-W

    2009-03-01

    The charge decay in isotactic polypropylene (i-PP) films of 50 µm thickness, containing three kinds of additives, namely a trisamide, a bisamide and a fluorinated compound, with concentrations in the range 0.004-1 wt% was studied. Compression molding was used to produce the films. The samples were either surface-charged by a corona method or volume-charged by mono-energetic electron beams of different energies, having penetration depths up to 6 µm. In all cases, surface potentials of about 200 V were chosen. After charging the films, the decay of the surface potential was studied either by an isothermal discharge method at 90 °C or by thermally stimulated discharge measurements. The results show a dependence of the decay rate on the kind of additive used, on additive concentration and on the energy of the injected charges. In particular, for samples with fluorinated additives, the stability of the surface potential decreases markedly with increasing electron energy, while such a dependence is very weak for samples containing the bisamide additive and does not exist at all for samples with the trisamide additive. These observations are tentatively explained by the radiation-induced generation of relatively mobile negative ions originating from the bisamide and fluorinated additives.

  8. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

    PubMed

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-01-01

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests. PMID:26395406

  9. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests

    PubMed Central

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-01-01

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m−2·yr−1), P addition (15 g P m−2·yr−1), and N and P addition (15 + 15 g N and P m−2·yr−1, respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests. PMID:26395406

  10. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-01

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m-2·yr-1), P addition (15 g P m-2·yr-1), and N and P addition (15 + 15 g N and P m-2·yr-1, respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  11. Effect of Particle Addition on Degradation Rate of Methylene Blue in an Ultrasonic Field

    NASA Astrophysics Data System (ADS)

    Honma, Chiemi; Kobayashi, Daisuke; Matsumoto, Hideyuki; Takahashi, Tomoki; Kuroda, Chiaki; Otake, Katsuto; Shono, Atsushi

    2013-07-01

    Ultrasound has been found to be an attractive advanced technology for the degradation of hazardous organic compounds in water. In addition, the sonochemical reaction is enhanced by particle addition. However, the enhancement mechanism of particle addition has not been investigated well, because ultrasound enhances not only chemical reactions but also mass transfer. In this study, the ultrasonic degradation of methylene blue was carried out, and the effects of the ultrasonic irradiation condition on the degradation rate were investigated. The effect of ultrasonic frequency on the improvement of degradation by particle addition was also investigated. The order of degradation rate with frequency was the same as the tendency of sonochemical efficiency value obtained using KI oxidation dosimetry method (SEKI). The degradation process of methylene blue was intensified by particle addition, and the degradation rate increased with increasing amount of particle addition. The enhancement of degradation rate by particle addition was influenced by both ultrasonic frequency and type or diameter of particles.

  12. Down-Regulation of Negative Emotional Processing by Transcranial Direct Current Stimulation: Effects of Personality Characteristics

    PubMed Central

    Peña-Gómez, Cleofé; Vidal-Piñeiro, Dídac; Clemente, Immaculada C.; Pascual-Leone, Álvaro; Bartrés-Faz, David

    2011-01-01

    Evidence from neuroimaging and electrophysiological studies indicates that the left dorsolateral prefrontal cortex (DLPFC) is a core region in emotional processing, particularly during down-regulation of negative emotional conditions. However, emotional regulation is a process subject to major inter-individual differences, some of which may be explained by personality traits. In the present study we used transcranial direct current stimulation (tDCS) over the left DLPFC to investigate whether transiently increasing the activity of this region resulted in changes in the ratings of positive, neutral and negative emotional pictures. Results revealed that anodal, but not cathodal, tDCS reduced the perceived degree of emotional valence for negative stimuli, possibly due to an enhancement of cognitive control of emotional expression. We also aimed to determine whether personality traits (extraversion and neuroticism) might condition the impact of tDCS. We found that individuals with higher scores on the introversion personality dimension were more permeable than extraverts to the modulatory effects of the stimulation. The present study underlines the role of the left DLPFC in emotional regulation, and stresses the importance of considering individual personality characteristics as a relevant variable, although replication is needed given the limited sample size of our study. PMID:21829522

  13. Effects of an experimental social stressor on resources loss, negative affect, and coping strategies.

    PubMed

    Zeidner, Moshe; Ben-Zur, Hasida

    2014-01-01

    This experimental study, grounded in Hobfoll's conservation of resources (COR) theory, assessed the effects of manipulating a social stressor on loss of psychological resources, negative affect, and coping strategies. Israeli student volunteers were randomly allocated to one of two conditions: (1) social stressor (n = 66) and (2.) nonstressor (n = 59). The social stressor, aimed at reducing participant's personal resources, was experimentally induced via the Trier Social Stress Test protocol. The protocol consisted of a mock job interview administered under evaluative conditions, followed by performing a difficult arithmetic calculation task. The nonstressor condition involved a neutral interaction with an experimenter, followed by performing a relatively easy mental calculation task. Consistent with our hypotheses, the social stressor, compared to the nonstressor condition, resulted in statistically significant lower mean levels of psychological resources, higher levels of negative affect, and increased emotion-oriented and avoidance-oriented coping. Furthermore, under the social stressor condition, compared with the nonstressor condition, negative affect was more strongly related to loss of psychological resources and various coping strategies. Overall, the data provide experimental support for key tenets of COR theory. PMID:24192220

  14. Regression approaches in the test-negative study design for assessment of influenza vaccine effectiveness.

    PubMed

    Bond, H S; Sullivan, S G; Cowling, B J

    2016-06-01

    Influenza vaccination is the most practical means available for preventing influenza virus infection and is widely used in many countries. Because vaccine components and circulating strains frequently change, it is important to continually monitor vaccine effectiveness (VE). The test-negative design is frequently used to estimate VE. In this design, patients meeting the same clinical case definition are recruited and tested for influenza; those who test positive are the cases and those who test negative form the comparison group. When determining VE in these studies, the typical approach has been to use logistic regression, adjusting for potential confounders. Because vaccine coverage and influenza incidence change throughout the season, time is included among these confounders. While most studies use unconditional logistic regression, adjusting for time, an alternative approach is to use conditional logistic regression, matching on time. Here, we used simulation data to examine the potential for both regression approaches to permit accurate and robust estimates of VE. In situations where vaccine coverage changed during the influenza season, the conditional model and unconditional models adjusting for categorical week and using a spline function for week provided more accurate estimates. We illustrated the two approaches on data from a test-negative study of influenza VE against hospitalization in children in Hong Kong which resulted in the conditional logistic regression model providing the best fit to the data. PMID:26732691

  15. Stereotype validation: the effects of activating negative stereotypes after intellectual performance.

    PubMed

    Clark, Jason K; Thiem, Kelsey C; Barden, Jamie; Stuart, Jillian O'Rourke; Evans, Abigail T

    2015-04-01

    With regard to intellectual performance, a large body of research has shown that stigmatized group members may perform more poorly when negative, self-relevant stereotypes become activated prior to a task. However, no research to date has identified the potential ramifications of stereotype activation that happens after-rather than before-a person has finished performing. Six studies examined how postperformance stereotype salience may increase the certainty individuals have in evaluations of their own performance. In the current research, the accessibility of gender or racial stereotypes was manipulated after participants completed either a difficult math test (Studies 1-5) or a test of child-care knowledge (Study 6). Consistent with predictions, stereotype activation was found to increase the certainty that women (Studies 1, 2, 4, and 5), African Americans (Study 3), and men (Study 6) had toward negative evaluations of their own test performance. These effects emerged when performance-related perceptions were stereotype consistent rather than inconsistent (Studies 1-6) and were found to be most pronounced among those who were highly identified with the stereotyped group (Study 5). Furthermore, greater certainty-triggered by negative stereotypes-predicted lowered domain-relevant beliefs (Studies 1, 2, 3, and 6) and differential exposure to domain-relevant stimuli (Studies 4 and 5). PMID:25844573

  16. Effect of enzyme concentration, addition of water and incubation time on increase in yield of starch from potato.

    PubMed

    Sit, Nandan; Agrawal, U S; Deka, Sankar C

    2014-05-01

    Enzymatic treatment process for starch extraction from potato was investigated using cellulase enzyme and compared with conventional process. The effects of three parameters, cellulase enzyme concentration, incubation time and addition of water were evaluated for increase in starch yield as compared to the conventional process i.e., without using enzyme. A two-level full factorial design was used to study the process. The results indicated that all the main parameters and their interactions are statistically significant. Enzyme concentration and incubation time had a positive effect on the increase in starch yield while addition of water had a negative effect. The increase in starch yield ranged from 1.9% at low enzyme concentration and incubation time and high addition of water to a maximum of 70% increase from conventional process in starch yield was achieved when enzyme concentration and incubation time were high and addition of water was low suggesting water present in the ground potato meal is sufficient for access to the enzyme with in the slurry ensuring adequate contact with the substrate. PMID:24803713

  17. Inhibitory and toxic effects of extracellular self-DNA in litter: a mechanism for negative plant-soil feedbacks?

    PubMed

    Mazzoleni, Stefano; Bonanomi, Giuliano; Incerti, Guido; Chiusano, Maria Luisa; Termolino, Pasquale; Mingo, Antonio; Senatore, Mauro; Giannino, Francesco; Cartenì, Fabrizio; Rietkerk, Max; Lanzotti, Virginia

    2015-02-01

    Plant-soil negative feedback (NF) is recognized as an important factor affecting plant communities. The objectives of this work were to assess the effects of litter phytotoxicity and autotoxicity on root proliferation, and to test the hypothesis that DNA is a driver of litter autotoxicity and plant-soil NF. The inhibitory effect of decomposed litter was studied in different bioassays. Litter biochemical changes were evaluated with nuclear magnetic resonance (NMR) spectroscopy. DNA accumulation in litter and soil was measured and DNA toxicity was assessed in laboratory experiments. Undecomposed litter caused nonspecific inhibition of root growth, while autotoxicity was produced by aged litter. The addition of activated carbon (AC) removed phytotoxicity, but was ineffective against autotoxicity. Phytotoxicity was related to known labile allelopathic compounds. Restricted (13) C NMR signals related to nucleic acids were the only ones negatively correlated with root growth on conspecific substrates. DNA accumulation was observed in both litter decomposition and soil history experiments. Extracted total DNA showed evident species-specific toxicity. Results indicate a general occurrence of litter autotoxicity related to the exposure to fragmented self-DNA. The evidence also suggests the involvement of accumulated extracellular DNA in plant-soil NF. Further studies are needed to further investigate this unexpected function of extracellular DNA at the ecosystem level and related cellular and molecular mechanisms. PMID:25354164

  18. Expanding the prion concept to cancer biology: dominant-negative effect of aggregates of mutant p53 tumour suppressor

    PubMed Central

    Silva, Jerson L.; Rangel, Luciana P.; Costa, Danielly C. F.; Cordeiro, Yraima; De Moura Gallo, Claudia V.

    2013-01-01

    p53 is a key protein that participates in cell-cycle control, and its malfunction can lead to cancer. This tumour suppressor protein has three main domains; the N-terminal transactivation domain, the CTD (C-terminal domain) and the core domain (p53C) that constitutes the sequence-specific DBD (DNA-binding region). Most p53 mutations related to cancer development are found in the DBD. Aggregation of p53 into amyloid oligomers and fibrils has been shown. Moreover, amyloid aggregates of both the mutant and WT (wild-type) forms of p53 were detected in tumour tissues. We propose that if p53 aggregation occurred, it would be a crucial aspect of cancer development, as p53 would lose its WT functions in an aggregated state. Mutant p53 can also exert a dominant-negative regulatory effect on WT p53. Herein, we discuss the dominant-negative effect in light of p53 aggregation and the fact that amyloid-like mutant p53 can convert WT p53 into more aggregated species, leading into gain of function in addition to the loss of tumour suppressor function. In summary, the results obtained in the last decade indicate that cancer may have characteristics in common with amyloidogenic and prion diseases. PMID:24003888

  19. Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

    2014-06-01

    Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southeast China. Solidago had more rapid mass and N loss rate than Phragmites when they decomposed separately. Litter mixing decreased N loss rate in Phragmites litter and increased that of Solidago. Large decreases in Phragmites mass loss and smaller increases in Solidago mass loss caused negative non-additive effect. Solidago litter extracts reduced soil C decomposition and N processes, suggested an inhibitory effect of Solidago secondary compounds. These results are consistent with the idea that nutrient transfer and secondary compounds both affected litter mixtures decomposition.

  20. Decomposition of Phragmites australis litter retarded by invasive Solidago canadensis in mixtures: an antagonistic non-additive effect

    PubMed Central

    Zhang, Ling; Zhang, Yaojun; Zou, Jianwen; Siemann, Evan

    2014-01-01

    Solidago canadensis is an aggressive invader in China. Solidago invasion success is partially attributed to allelopathic compounds release and more benefits from AM fungi, which potentially makes the properties of Solidago litter different from co-occurring natives. These properties may comprehensively affect litter decomposition of co-occurring natives. We conducted a field experiment to examine litter mixing effects in a Phragmites australis dominated community invaded by Solidago in southeast China. Solidago had more rapid mass and N loss rate than Phragmites when they decomposed separately. Litter mixing decreased N loss rate in Phragmites litter and increased that of Solidago. Large decreases in Phragmites mass loss and smaller increases in Solidago mass loss caused negative non-additive effect. Solidago litter extracts reduced soil C decomposition and N processes, suggested an inhibitory effect of Solidago secondary compounds. These results are consistent with the idea that nutrient transfer and secondary compounds both affected litter mixtures decomposition. PMID:24976274

  1. Effect of Oxygen-affinity Additives on the Superconducting Properties of Magnesium Diboride

    NASA Astrophysics Data System (ADS)

    Jang, J.-J.; Ahn, J.-H.

    We examined the effect of oxygen-affinity additives on the superconducting properties of magnesium diborides. The additives were elemental Y, Sm, Ca, Li compounds (LiH, LiBH4), polyethylene and polyethylene glycol, which have a higher oxygen-affinity than magnesium. The formation of magnesium oxide during in-situ sintering of magnesium diboride was inhibited by the addition of such materials. The critical current density was not improved by the additives of Y, Sm, Ca and lithium compounds in spite of reduced oxide phases. Only the addition of polyethylene and polyethylene glycol resulted in the enhanced superconducting property.

  2. Nanoparticle-induced negative differential resistance and memory effect in polymer bistable light-emitting device

    NASA Astrophysics Data System (ADS)

    Tseng, Ricky J.; Ouyang, Jianyong; Chu, Chih-Wei; Huang, Jinsong; Yang, Yang

    2006-03-01

    Recently, electrical bistability was demonstrated in polymer thin films incorporated with metal nanoparticles [J. Ouyang, C. W. Chu, C. R. Szmanda, L. P. Ma, and Y. Yang, Nat. Mater. 3, 918 (2004)]. In this letter, we show the evidence that electrons are the dominant charge carriers in these bistable devices. Direct integration of bistable polymer layer with a light-emitting polymer layer shows a unique light-emitting property modulated by the electrical bistability. A unique negative differential resistance induced by the charged gold nanoparticles is observed due to the charge trapping effect from the nanoparticles when interfaced with the light-emitting layer.

  3. Effect of facial hair on the face seal of negative-pressure respirators

    SciTech Connect

    Skretvedt, O.T.; Loschiavo, J.G.

    1984-01-01

    The effect of facial hair on the face seal of negative-pressure respirators, both half-masks and full facepieces, has been investigated. 370 male employees were fit tested both qualitatively and quantitatively. Of these, 67 had fully established beards. Bearded subjects consistently failed the qualitative fit test protocol. With half-mask respirators, an average 246-fold drop in protection was experienced by bearded employees in comparison with clean-shaven subjects; for full facepiece respirators, at least a 330-fold drop in protection was experienced by bearded employees. The presence of a beard greatly increases the leakage through the respirator face seal.

  4. Investigation of three-terminal organic-based devices with memory effect and negative differential resistance

    NASA Astrophysics Data System (ADS)

    Yu, Li-Zhen; Lee, Ching-Ting

    2009-09-01

    The current-voltage characteristics of the gate-controlled three-terminal organic-based devices with memory effect and negative differential resistances (NDR) were studied. Gold and 9,10-di(2-naphthyl)anthracene (ADN) were used as the metal electrode and active channel layer of the devices, respectively. By using various gate-source voltages, the memory and NDR characteristics of the devices can be modulated. The memory and NDR characteristics of the devices were attributed to the formation of trapping sites in the interface between Au electrode and ADN active layer caused by the defects, when Au metal deposited on the ADN active layer.

  5. Negative differential gain in quantum dot systems: Interplay of structural properties and many-body effects

    SciTech Connect

    Goldmann, E. Jahnke, F.; Lorke, M.; Frauenheim, T.

    2014-06-16

    The saturation behaviour of optical gain with increasing excitation density is an important factor for laser device performance. For active materials based on self-organized InGaAs/GaAs quantum dots, we study the interplay between structural properties of the quantum dots and many-body effects of excited carriers in the optical properties via a combination of tight-binding and quantum-kinetic calculations. We identify regimes where either phase-space filling or excitation-induced dephasing dominates the saturation behavior of the optical gain. The latter can lead to the emergence of a negative differential material gain.

  6. Triangular lattice of carbon nanotube arrays for negative index of refraction and subwavelength lensing effect

    SciTech Connect

    Wang, Y.; Wang, X.; Rybczynski, J.; Wang, D.Z.; Kempa, K.; Ren, Z.F.

    2005-04-11

    Self-assembly of polystyrene microspheres has been utilized in a two-step masking technique to prepare triangular lattices of catalytic nanodots at low cost. Subsequent triangular lattices of aligned carbon nanotubes on a silicon substrate are achieved by plasma-enhanced chemical vapor deposition. Nickel is used both in the nanodots and in the secondary mask. The triangular lattices of carbon nanotube arrays as two-dimensional photonic crystals show higher geometrical symmetry than the hexagonal lattices previously reported, enabling broader applications including negative index of refraction and subwavelength lensing effect.

  7. Countermeasure of the negative effects of weightlessness on physical systems in long-term space flights

    NASA Astrophysics Data System (ADS)

    Kozlovskaya, I. B.; Grigoriev, A. I.; Stepantzov, V. I.

    The system of countermcasure of microgravity effects has been developed in Russia that allowed to perform safely long-term space flights. This system that includes different means and methods such as special regimens of physical exercises, axial loading ("Pingiun") and antigravity suits, low body negative pressure device (LBNP, "Chibis") and "cuffs" and others has been used with certain variations at certain stages of flight in 27 successfully accomplished space flights that lasted from 60 to 439 days. The pre-, in- and postflight studies performed in 57 crew members of these flights have shown that the system of countermeasure is effective in preventing or diminishing to a great extent almost all the negative effects of weightlessness in flights of a year and more duration and that the intensity and duration of changes recorded in different body systems after flights do not correlate significantly to flight durations, correlating strongly to the volume and intensity of physical exercises used during flight and especially during concluding stage of it.

  8. Positive and Negative Effects of Alcohol and Nicotine and Their Interactions: A Mechanistic Review

    PubMed Central

    Hurley, Laura L.; Taylor, Robert E.

    2012-01-01

    Nicotine and alcohol are two of the most commonly abused legal substances. Heavy use of one drug can often lead to, or is predictive of, heavy use of the other drug in adolescents and adults. Heavy drinking and smoking alone are of significant health hazard. The combination of the two, however, can result in synergistic adverse effects particularly in incidences of various cancers (e.g., esophagus). Although detrimental consequences of smoking are well established, nicotine by itself might possess positive and even therapeutic potential. Similarly, alcohol at low or moderated doses may confer beneficial health effects. These opposing findings have generated considerable interest in how these drugs act. Here we will briefly review the negative impact of drinking–smoking co-morbidity followed by factors that appear to contribute to the high rate of co-use of alcohol and nicotine. Our main focus will be on what research is telling us about the central actions and interactions of these drugs, and what has been elucidated about the mechanisms of their positive and negative effects. We will conclude by making suggestions for future research in this area. PMID:21932109

  9. Localization of click trains and speech by cats: the negative level effect.

    PubMed

    Gai, Yan; Ruhland, Janet L; Yin, Tom C T

    2014-10-01

    Although localization of sound in elevation is believed to depend on spectral cues, it has been shown with human listeners that the temporal features of sound can also greatly affect localization performance. Of particular interest is a phenomenon known as the negative level effect, which describes the deterioration of localization ability in elevation with increasing sound level and is observed only with impulsive or short-duration sound. The present study uses the gaze positions of domestic cats as measures of perceived locations of sound targets varying in azimuth and elevation. The effects of sound level on localization in terms of accuracy, precision, and response latency were tested for sound with different temporal features, such as a click train, a single click, a continuous sound that had the same frequency spectrum of the click train, and speech segments. In agreement with previous human studies, negative level effects were only observed with click-like stimuli and only in elevation. In fact, localization of speech sounds in elevation benefited significantly when the sound level increased. Our findings indicate that the temporal continuity of a sound can affect the frequency analysis performed by the auditory system, and the variation in the frequency spectrum contained in speech sound does not interfere much with the spectral coding for its location in elevation. PMID:24942705

  10. Differential negative air ion effects on learning disabled and normal-achieving children

    NASA Astrophysics Data System (ADS)

    Morton, L. L.; Kershner, J. R.

    1990-03-01

    Forty normal-achieving and 33 learning disabled (LD) children were assigned randomly to either a negative ion or placebo test condition. On a dichotic listening task using consonant-vowel (CV) combinations, both groups showed an ioninduced increase in the normal right ear advantage (REA). However, the mechanisms for this effect were different for each group. The LDs showed the effect at the right ear/left hemisphere (enhancement). The normal achievers showed the effect at the left ear/right hemisphere (inhibition). The results are consistent with an activation-inhibition model of cerebral function and suggest a functional relationship between arousal, interhemispheric activation-inhibition, and learning disabilities. The LDs may have an interhemispheric dysfunction. Both groups showed superior right ear report and the normal achiever showed overall superiority. Normal achievers showed higher consonant intrusion scores, probably due to a greater cognitive capacity. Age was a significant covariate reflecting developmental capacity changes. Negative air ions are seen to be a tool with potential theoretical and remedial applications.

  11. Revisiting the therapeutic effect of rTMS on negative symptoms in schizophrenia: A meta-analysis

    PubMed Central

    Shi, Chuan; Yu, Xin; Cheung, Eric F.C.; Shum, David H.K.; Chan, Raymond C.K.

    2014-01-01

    This study sought to determine the moderators in the treatment effect of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms in schizophrenia. We performed a meta-analysis of prospective studies on the therapeutic application of rTMS in schizophrenia assessing the effects of both low-frequency and high-frequency rTMS on negative symptoms. Results indicate that rTMS is effective in alleviating negative symptoms in schizophrenia. The effect size was moderate (0.63 and 0.53, respectively). The effect size of rTMS on negative symptoms in sham-controlled trials was 0.80 as measured by the SANS and 0.41 as measured by the PANSS. A longer duration of illness was associated with poorer efficacy of rTMS on negative symptoms. A 10 Hz setting, at least 3 consecutive weeks of treatment, treatment site at the left dorsolateral prefrontal cortex (DLPFC) and a 110% motor threshold (MT) were found to be the best rTMS parameters for the treatment of negative symptoms. The results of our meta-analysis suggest that rTMS is an effective treatment option for negative symptoms in schizophrenia. The moderators of rTMS on negative symptoms included duration of illness, stimulus frequency, duration of illness, position and intensity of treatment as well as the type of outcome measures used. PMID:24411074

  12. Is the Memory Effect of the Blind Spot Involved in Negative Dysphotopsia after Cataract Surgery?

    PubMed Central

    Wenzel, Martin; Menapace, Rupert; Eppig, Timo; Langenbucher, Achim

    2015-01-01

    We present novel clinical observations on negative dysphotopsia (ND) in eyes that have undergone cataract surgery. In the past, shadow effects were alleged to be located in the far peripheral temporal visual field 50° to 100° away from the optical axis. In a small series of eight patients we found evidence of photic effects, described by the patients as shadows in the periphery that were objectively located much more centrally. In all cases, we could find an association of these phenomena with the blind spot. We hypothesize that the memory effect of the blind spot which is dislocated and changed in magnification due to replacement of the crystalline lens could be one determinant for pseudophakic ND. The scotoma of the optic nerve head and the main arteries and veins of the phakic eye are displaced in the pseudophakic eye depending on the specific characteristics and position of the intraocular lens within the eye. PMID:26425353

  13. Study on nitrogen doped carbon atom chains with negative differential resistance effect

    NASA Astrophysics Data System (ADS)

    Shen, Ji-Mei; Liu, Jing; Min, Yi; Zhou, Li-Ping

    2016-05-01

    Recent calculations (Mahmoud and Lugli, 2013, [21]) of gold leads sandwiching carbon chains which are separated by diphenyl-dimethyl demonstrated that the negative differential resistance (NDR) effect appears only for "odd" numbers of carbon atoms. In this paper, according to a first-principles study based on non-equilibrium Green's function combining density functional theory, we find that the NDR effect appears both for "odd" and for "even" numbers of carbon atoms when the chains are doped by nitrogen atom. Our calculations remove the restriction of "odd/even" chains for the NDR effect, which may promise the potential applications of carbon chains in the nano-scale or molecular devices in the future.

  14. Colossal positive and negative thermal expansion and thermosalient effect in a pentamorphic organometallic martensite.

    PubMed

    Panda, Manas K; Runčevski, Tomče; Sahoo, Subash Chandra; Belik, Alexei A; Nath, Naba K; Dinnebier, Robert E; Naumov, Panče

    2014-01-01

    The thermosalient effect is an extremely rare propensity of certain crystalline solids for self-actuation by elastic deformation or by a ballistic event. Here we present direct evidence for the driving force behind this impressive crystal motility. Crystals of a prototypical thermosalient material, (phenylazophenyl)palladium hexafluoroacetylacetonate, can switch between five crystal structures (α-ε) that are related by four phase transitions including one thermosalient transition (α↔γ). The mechanical effect is driven by a uniaxial negative expansion that is compensated by unusually large positive axial expansion (260 × 10(-6)  K(-1)) with volumetric expansion coefficients (≈250 × 10(-6)  K(-1)) that are among the highest values reported in molecular solids thus far. The habit plane advances at ~10(4) times the rate observed with non-thermosalient transitions. This rapid expansion of the crystal following the phase switching is the driving force for occurrence of the thermosalient effect. PMID:25185949

  15. Novel Cytokinin Derivatives Do Not Show Negative Effects on Root Growth and Proliferation in Submicromolar Range

    PubMed Central

    Podlešáková, Kateřina; Zalabák, David; Čudejková, Mária; Plíhal, Ondřej; Szüčová, Lucie; Doležal, Karel; Spíchal, Lukáš; Strnad, Miroslav; Galuszka, Petr

    2012-01-01

    Background When applied to a nutrition solution or agar media, the non-substituted aromatic cytokinins caused thickening and shortening of the primary root, had an inhibitory effect on lateral root branching, and even showed some negative effects on development of the aerial part at as low as a 10 nanomolar concentration. Novel analogues of aromatic cytokinins ranking among topolins substituted on N9-atom of adenine by tetrahydropyranyl or 4-chlorobutyl group have been prepared and tested in standardized cytokinin bioassays [1]. Those showing comparable activities with N6-benzylaminopurine were further tested in planta. Methodology/Principal Findings The main aim of the study was to explain molecular mechanism of function of novel cytokinin derivatives on plant development. Precise quantification of cytokinin content and profiling of genes involved in cytokinin metabolism and perception in treated plants revealed several aspects of different action of m-methoxytopolin base and its substituted derivative on plant development. In contrast to standard cytokinins, N9- tetrahydropyranyl derivative of m-topolin and its methoxy-counterpart showed the negative effects on root development only at three orders of magnitude higher concentrations. Moreover, the methoxy-derivative demonstrates a positive effect on lateral root branching and leaf emerging in a nanomolar range of concentrations, in comparison with untreated plants. Conclusions/Significance Tetrahydropyranyl substitution at N9-position of cytokinin purine ring significantly enhances acropetal transport of a given cytokinins. Together with the methoxy-substitution, impedes accumulation of non-active cytokinin glucoside forms in roots, allows gradual release of the active base, and has a significant effect on the distribution and amount of endogenous isoprenoid cytokinins in different plant tissues. The utilization of novel aromatic cytokinin derivatives can distinctively improve expected hormonal effects in plant

  16. Magnetic Flux Concentrations in Stratified Turbulent Plasma Due to Negative Effective Magnetic Pressure Instability

    NASA Astrophysics Data System (ADS)

    Jabbari, S.; Brandenburg, A.

    2014-12-01

    Recent studies have suggested a new mechanism that can be used to explain the formation of magnetic spots or bipolar regions in highly stratified turbulent plasmas. According to this model, a large-scale magnetic field suppresses the turbulent pressure, which leads to a negative contribution of turbulence to the effective magnetic pressure. Direct numerical simulations (DNS) have confirmed that the negative contribution is large enough so that the effective magnetic pressure becomes negative and leads to a large-scale instability, which we refer to as negative effective magnetic pressure Instability (NEMPI). NEMPI was used to explain the formation of active regions and sunspots on the solar surface. One step toward improving this model was to combine dynamo in- stability with NEMPI. The dynamo is known to be responsible for the solar large-scale magnetic field and to play a role in solar activity. In this context, we studied stratified turbulent plasmas in spherical geometry, where the background field was generated by alpha squared dynamo. For NEMPI to be excited, the initial magnetic field should be in a proper range, so we used quenching function for alpha. Using the Pencil Code and mean field simulations (MFS), we showed that in the presence of dynamo-generated magnetic fields, we deal with a coupled system, where both instabilities, dynamo and NEMPI, work together and lead to the formation of magnetic structures (Jabbari et al. 2013). We also studied a similar system in plane geometry in the presence of rotation and confirmed that for slow rotation NEMPI works, but as the Coriolis number increases, the rotation suppresses NEMPI. By increasing the Coriolis number even further, the combination of fast rotation and high stratification excites a dynamo, which leads again to a coupled system of dynamo and NEMPI (Jabbari et al. 2014). Another important finding concerning NEMPI is the case where the instability is excited by a vertical magnetic field (Brandenburg et

  17. Effect of silver addition on thermoelectric properties of half-doped rare-earth manganite

    NASA Astrophysics Data System (ADS)

    Khade, Poonam; Bagwaiya, Toshi; Bhattacharya, Shovit; Aswal, D. K.; Gupta, S. K.; Shelke, Vilas

    2016-05-01

    We have synthesized polycrystalline samples with nominal compositions La0.5Ca0.5MnO3-Agx (0 ≤ x ≤ 0.1) by solid state reaction method and studied thermoelectric properties within the temperature range of 300K to 800K. The electrical resistivity decreases with increasing temperature for all the samples. The Seebeck coefficient (S) increases gradually with temperature and negative sign of indicates n-type nature. The addition of silver causes a drastic reduction in electrical resistivity and significant enhancement in Seebeck coefficient.

  18. Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

    DOE PAGESBeta

    Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.; Ciesielski, Filip; Kuzmenko, Ivan; Holt, Stephen A.; Lakey, Jeremy H.

    2014-12-09

    The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg2+ and Ca2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutronmore » reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.« less

  19. Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

    SciTech Connect

    Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.; Ciesielski, Filip; Kuzmenko, Ivan; Holt, Stephen A.; Lakey, Jeremy H.

    2014-12-09

    The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg2+ and Ca2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.

  20. Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

    PubMed Central

    2014-01-01

    The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg2+ and Ca2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration. PMID:25489959

  1. Effect of urea addition on giant reed ensilage and subsequent methane production by anaerobic digestion.

    PubMed

    Liu, Shan; Ge, Xumeng; Liew, Lo Niee; Liu, Zhe; Li, Yebo

    2015-09-01

    The effect of urea addition on giant reed ensilage and sequential anaerobic digestion (AD) of the ensiled giant reed was evaluated. The dry matter loss during ensilage (up to 90 days) with or without urea addition was about 1%. Addition of 2% urea enhanced production of lactic acid by about 4 times, and reduced production of propionic acid by 2-8 times. Besides, urea addition reduced degradation of cellulose and hemicellulose, and increased degradation of lignin in giant reed during ensilage. Ensilage with or without urea addition had no significant effects on the enzymatic digestibility of giant reed, but ensilage with urea addition achieved a cumulative methane yield of 173 L/kg VS, which was 18% higher than that of fresh giant reed. The improved methane yield of giant reed could be attributed to the production of organic acids and ethanol during ensilage. PMID:26094194

  2. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking.

    PubMed

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the "laws of perceptual organization" proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. "Additive effect" refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The "where" and "what" pathways might have played an important role in the additive grouping effect. PMID:27199875

  3. Transport properties of bare and hydrogenated zigzag silicene nanoribbons: Negative differential resistances and perfect spin-filtering effects

    SciTech Connect

    Yang, X. F.; Liu, Y. S. Feng, J. F.; Wang, X. F.; Zhang, C. W.; Chi, F.

    2014-09-28

    Ab initio calculations are performed to investigate the spin-polarized transport properties of the bare and hydrogenated zigzag silicene nanoribbons (ZSiNRs). The results show that the ZSiNRs with symmetric (asymmetric) edges prefer the ferromagnetic (antiferromagnetic) as their ground states with the semiconductor properties, while the accordingly antiferromagnetic (ferromagnetic) states exhibit the metallic behaviors. These facts result in a giant magnetoresistance behavior between the ferromagnetic and antiferromagnetic states in the low bias-voltage regime. Moreover, in the ferromagnetic ZSiNRs with asymmetric edges, a perfect spin-filtering effect with 100% positive electric current polarization can be achieved by altering the bias voltage. In addition, we also find that the negative differential resistances prefer the metastable states. The findings here indicate that the asymmetric and symmetric ZSiNRs are promising materials for spintronic applications.

  4. Frequencies of Inaudible High-Frequency Sounds Differentially Affect Brain Activity: Positive and Negative Hypersonic Effects

    PubMed Central

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10–13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC. PMID:24788141

  5. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    PubMed

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC. PMID:24788141

  6. Exploring modality switching effects in negated sentences: further evidence for grounded representations.

    PubMed

    Hald, Lea A; Hocking, Ian; Vernon, David; Marshall, Julie-Ann; Garnham, Alan

    2013-01-01

    Theories of embodied cognition (e.g., Perceptual Symbol Systems Theory; Barsalou, 1999, 2009) suggest that modality specific simulations underlie the representation of concepts. Supporting evidence comes from modality switch costs: participants are slower to verify a property in one modality (e.g., auditory, BLENDER-loud) after verifying a property in a different modality (e.g., gustatory, CRANBERRIES-tart) compared to the same modality (e.g., LEAVES-rustling, Pecher et al., 2003). Similarly, modality switching costs lead to a modulation of the N400 effect in event-related potentials (ERPs; Collins et al., 2011; Hald et al., 2011). This effect of modality switching has also been shown to interact with the veracity of the sentence (Hald et al., 2011). The current ERP study further explores the role of modality match/mismatch on the processing of veracity as well as negation (sentences containing "not"). Our results indicate a modulation in the ERP based on modality and veracity, plus an interaction. The evidence supports the idea that modality specific simulations occur during language processing, and furthermore suggest that these simulations alter the processing of negation. PMID:23450002

  7. Functional diversity of catch mitigates negative effects of temperature variability on fisheries yields.

    PubMed

    Dee, Laura E; Miller, Steve J; Peavey, Lindsey E; Bradley, Darcy; Gentry, Rebecca R; Startz, Richard; Gaines, Steven D; Lester, Sarah E

    2016-08-17

    Temperature variation within a year can impact biological processes driving population abundances. The implications for the ecosystem services these populations provide, including food production from marine fisheries, are poorly understood. Whether and how temperature variability impacts fishery yields may depend on the number of harvested species and differences in their responses to varying temperatures. Drawing from previous theoretical and empirical studies, we predict that greater temperature variability within years will reduce yields, but harvesting a larger number of species, especially a more functionally diverse set, will decrease this impact. Using a global marine fisheries dataset, we find that within-year temperature variability reduces yields, but current levels of functional diversity (FD) of targeted species, measured using traits related to species' responses to temperature, largely offset this effect. Globally, high FD of catch could avoid annual losses in yield of 6.8% relative to projections if FD were degraded to the lowest level observed in the data. By contrast, species richness in the catch and in the ecosystem did not provide a similar mitigating effect. This work provides novel empirical evidence that short-term temperature variability can negatively impact the provisioning of ecosystem services, but that FD can buffer these negative impacts. PMID:27534960

  8. Parental warmth amplifies the negative effect of parental hostility on dating violence.

    PubMed

    Simons, Leslie Gordon; Simons, Ronald L; Lei, Man-Kit; Hancock, Donna L; Fincham, Frank D

    2012-09-01

    Past research has documented the positive association between parental hostility and offspring involvement in intimate partner violence. Researchers, practitioners, and parents typically adopt the standpoint that parental warmth may counter these negative lessons. However, Straus and colleagues argue that parents foster IPV to the extent that they teach their child that verbal and physical aggression are a normal and legitimate component of loving relationships. A strict interpretation of social learning theory would suggest that these lessons are more, not less, likely to occur when parental hostility is interspersed with displays of affection. The present study tests this idea using data from 2,088 undergraduate students from a large university in the Southeast. Consistent with Straus' arguments, findings suggest that, rather than attenuating the negative effects of hostility, supportive interactions seem to amplify the probability that offspring will emulate aggressive behaviors in their own romantic relationships. The same is true for the effects of harsh parenting for women. It seems that the best way parents can avoid contributing to their child's chances of being in a violent dating relationship is to eschew family interaction involving verbal and physical aggression. PMID:22491219

  9. Effects of biological pit additives on microbial ecology of stored pig manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of biological pit additives on microbial ecology in stored pig manure were investigated using a dynamic manure storage system, which allowed for continual addition of swine feces and urine. After 13 weeks of manure collection and storage, four treatments were added to tanks (900 L capaci...

  10. Parental Anxiety and Child Symptomatology: An Examination of Additive and Interactive Effects of Parent Psychopathology

    ERIC Educational Resources Information Center

    Burstein, Marcy; Ginsburg, Golda S.; Tein, Jenn-Yun

    2010-01-01

    The current study examined relations between parent anxiety and child anxiety, depression, and externalizing symptoms. In addition, the study tested the additive and interactive effects of parent anxiety with parent depression and externalizing symptoms in relation to child symptoms. Forty-eight parents with anxiety disorders and 49 parents…

  11. Metabolic effects of ß-glucans addition to corn maize flour

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of ß-glucans to degermed precooked corn maize flour produced favorably low metabolic responses in healthy young subjects. The increase in viscosity in the small intestine during the digestion period is the proposed mechanism for this effect. The addition of ß-glucans to corn maize pro...

  12. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking

    PubMed Central

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the “laws of perceptual organization” proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. “Additive effect” refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The “where” and “what” pathways might have played an important role in the additive grouping effect. PMID:27199875

  13. The effect of alkaline additives on the performance of surfactant systems designed to recover light oils

    SciTech Connect

    French, T.R.; Josephson, C.B.; Evans, D.B.

    1991-02-01

    Surfactant flooding is flexible because of the ability to optimize formulations for a wide range of reservoir conditions and crude oil types. The objective for this work was to determine if the addition of alkaline additives will allow the design of surfactant formulations that are effective for the recovery of crude oil, while, at the same time, maintaining the surfactant concentration at a much lower level than has previously been used for micellar flooding. Specifically, the focus of the work was on light, midcontinent crudes that typically have very low acid contents. These oils are typical of much of the midcontinent resource. The positive effect of alkaline additives on the phase behavior of the surfactant formulations and acidic crude oils is well known. The extension to nonacidic and slightly acidic oils is not obvious. Three crude oils, a variety of commercial surfactants, and several alkaline additives were tested. The oils had acid numbers that ranged from 0.13, which is quite low, to less than 0.01 mg KOH/g of oil. Alkaline additives were found to be very effective in recovering Delaware-Childers (OK) oil at elevated temperatures, but much less effective at reservoir temperatures. Alkaline additives were very effective with Teapot Dome (WY) oil. With Teapot Dome oil, surfactant/alkali systems produced ultralow IFT values and recovered 60% of the residual oil that remained after waterflooding. The effect of alkaline additives on recovering Hepler (KS) oil was minimal. The results of this work indicate that alkaline additives do have merit for use in surfactant flooding of low acid crude oils; however, no universal statement about applicability can be made. Each oil behaves differently, with this treatment, and the effect of alkaline additives must be determined (at reservoir conditions) for each oil. 23 refs., 13 figs., 3 tabs.

  14. Relationships between parental negativity and childhood antisocial behavior over time: a bidirectional effects model in a longitudinal genetically informative design.

    PubMed

    Larsson, Henrik; Viding, Essi; Rijsdijk, Fruhling V; Plomin, Robert

    2008-07-01

    This study examined the direction and etiology underlying the relationships between parental negativity and early childhood antisocial behavior using a bidirectional effects model in a longitudinal genetically informative design. We analyzed parent reports of parental negativity and early childhood antisocial behavior in 6,230 pairs of twins at 4 and 7 years of age. Results from a cross-lagged twin model contribute to the understanding of the mechanisms underlying the bidirectional processes involved in parental negativity and childhood antisocial behavior. Specifically, the findings of this study suggest that the association between parenting and child antisocial behavior is best explained by both parent-driven and child-driven effects. We found support for the notion that parent's negative feelings towards their children environmentally mediate the risk for child antisocial behavior. We also found evidence of genetically mediated child effects; in which genetically influenced antisocial behavior evoke parental negativity towards the child. PMID:17602294

  15. 75 FR 66752 - ILP Effectiveness Evaluation 2010; Additional Notice of Multi-Stakeholder Technical Conference on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission ILP Effectiveness Evaluation 2010; Additional Notice of Multi- Stakeholder..., ``Notice of Interviews, Teleconferences, Regional Workshops And Multi-Stakeholder Technical Conference...

  16. Low-bias negative differential resistance effect in armchair graphene nanoribbon junctions

    SciTech Connect

    Li, Suchun; Gan, Chee Kwan; Son, Young-Woo; Feng, Yuan Ping; Quek, Su Ying

    2015-01-05

    Graphene nanoribbons with armchair edges (AGNRs) have bandgaps that can be flexibly tuned via the ribbon width. A junction made of a narrower AGNR sandwiched between two wider AGNR leads was recently reported to possess two perfect transmission channels close to the Fermi level. Here, we report that by using a bias voltage to drive these transmission channels into the gap of the wider AGNR lead, we can obtain a negative differential resistance (NDR) effect. Owing to the intrinsic properties of the AGNR junctions, the on-set bias reaches as low as ∼0.2 V and the valley current almost vanishes. We further show that such NDR effect is robust against details of the atomic structure of the junction, substrate, and whether the junction is made by etching or by hydrogenation.

  17. Perfect spin filtering effect and negative differential behavior in phosphorus-doped zigzag graphene nanoribbons

    PubMed Central

    Zou, Fei; Zhu, Lin; Yao, Kailun

    2015-01-01

    On the basis of the density functional theory combined with the Keldysh nonequilibrium Green’s function method, we investigate the spin-dependent transport properties of single-edge phosphorus-doped ZGNR systems with different widths. The results show a perfect spin filtering effect reaching 100% at a wide bias range in both parallel (P) and antiparallel (AP) spin configurations for all systems, especially for 6-ZGNR-P system. Instructively, for the AP spin configuration, the spin down current of the 4-ZGNR-P system exhibits a negative differential effect. By analyzing the transmission spectrum and the spin-resolved band structures of the electrodes, we elucidate the mechanism for these peculiar properties. Our findings provide a new way to produce multifunctional spintronic devices based on phosphorus-doped zigzag graphene nanoribbons. PMID:26514646

  18. How increasing CO2 leads to an increased negative greenhouse effect in Antarctica

    NASA Astrophysics Data System (ADS)

    Schmithüsen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter; Jung, Thomas

    2015-12-01

    CO2 is the strongest anthropogenic forcing agent for climate change since preindustrial times. Like other greenhouse gases, CO2 absorbs terrestrial surface radiation and causes emission from the atmosphere to space. As the surface is generally warmer than the atmosphere, the total long-wave emission to space is commonly less than the surface emission. However, this does not hold true for the high elevated areas of central Antarctica. For this region, the emission to space is higher than the surface emission; and the greenhouse effect of CO2 is around zero or even negative, which has not been discussed so far. We investigated this in detail and show that for central Antarctica an increase in CO2 concentration leads to an increased long-wave energy loss to space, which cools the Earth-atmosphere system. These findings for central Antarctica are in contrast to the general warming effect of increasing CO2.

  19. Negative Effects of Reward on Intrinsic Motivation--A Limited Phenomenon: Comment on Deci, Koestner, and Ryan (2001).

    ERIC Educational Resources Information Center

    Cameron, Judy

    2001-01-01

    Prior meta analyses by J. Cameron and other researchers suggested that the negative effects of extrinsic reward on intrinsic motivation were limited and avoidable. E. Deci and others (2001) suggested that the analyses were flawed. This commentary makes the case that there is no inherent negative property of reward. (SLD)

  20. A Fine-Grained Analysis of the Effects of Negative Evidence with and without Metalinguistic Information in Language Development

    ERIC Educational Resources Information Center

    Lado, Beatriz; Bowden, Harriet Wood; Stafford, Catherine A; Sanz, Cristina

    2014-01-01

    The current study compared the effectiveness of computer-delivered task-essential practice coupled with feedback consisting of (1) negative evidence with metalinguistic information (NE+MI) or (2) negative evidence without metalinguistic information (NE-MI) in promoting absolute beginners' (n = 58) initial learning of aspects of Latin…

  1. Relationships between Parental Negativity and Childhood Antisocial Behavior over Time: A Bidirectional Effects Model in a Longitudinal Genetically Informative Design

    ERIC Educational Resources Information Center

    Larsson, Henrik; Viding, Essi; Rijsdijk, Fruhling V.; Plomin, Robert

    2008-01-01

    This study examined the direction and etiology underlying the relationships between parental negativity and early childhood antisocial behavior using a bidirectional effects model in a longitudinal genetically informative design. We analyzed parent reports of parental negativity and early childhood antisocial behavior in 6,230 pairs of twins at 4…

  2. Giant Negative Electrocaloric Effect in Antiferroelectric La-Doped Pb(ZrTi)O3 Thin Films Near Room Temperature.

    PubMed

    Geng, Wenping; Liu, Yang; Meng, Xiangjian; Bellaiche, Laurent; Scott, James F; Dkhil, Brahim; Jiang, Anquan

    2015-05-27

    Antiferroelectric thin films are demonstrated as a new class of giant electrocaloric materials that exhibit a negative electrocaloric response of about -5 K near room temperature. The giant negative electrocaloric effect may open up a new paradigm for light, compact, reliable, and high-efficiency refrigeration devices. PMID:25864588

  3. Arbuscular mycorrhizae alleviate negative effects of zinc oxide nanoparticle and zinc accumulation in maize plants--A soil microcosm experiment.

    PubMed

    Wang, Fayuan; Liu, Xueqin; Shi, Zhaoyong; Tong, Ruijian; Adams, Catharine A; Shi, Xiaojun

    2016-03-01

    ZnO nanoparticles (NPs) are considered an emerging contaminant when in high concentration, and their effects on crops and soil microorganisms pose new concerns and challenges. Arbuscular mycorrhizal (AM) fungi (AMF) form mutualistic symbioses with most vascular plants, and putatively contribute to reducing nanotoxicity in plants. Here, we studied the interactions between ZnO NPs and maize plants inoculated with or without AMF in ZnO NPs-spiked soil. ZnO NPs had no significant adverse effects at 400 mg/kg, but inhibited both maize growth and AM colonization at concentrations at and above 800 mg/kg. Sufficient addition of ZnO NPs decreased plant mineral nutrient acquisition, photosynthetic pigment concentrations, and root activity. Furthermore, ZnO NPs caused Zn concentrations in plants to increase in a dose-dependent pattern. As the ZnO NPs dose increased, we also found a positive correlation with soil diethylenetriaminepentaacetic acid (DTPA)-extractable Zn. However, AM inoculation significantly alleviated the negative effects induced by ZnO NPs: inoculated-plants experienced increased growth, nutrient uptake, photosynthetic pigment content, and SOD activity in leaves. Mycorrhizal plants also exhibited decreased ROS accumulation, Zn concentrations and bioconcentration factor (BCF), and lower soil DTPA-extractable Zn concentrations at high ZnO NPs doses. Our results demonstrate that, at high contamination levels, ZnO NPs cause toxicity to AM symbiosis, but AMF help alleviate ZnO NPs-induced phytotoxicity by decreasing Zn bioavailability and accumulation, Zn partitioning to shoots, and ROS production, and by increasing mineral nutrients and antioxidant capacity. AMF may play beneficial roles in alleviating the negative effects and environmental risks posed by ZnO NPs in agroecosystems. PMID:26761602

  4. Chloroquine has tumor-inhibitory and tumor-promoting effects in triple-negative breast cancer

    PubMed Central

    TUOMELA, JOHANNA; SANDHOLM, JOUKO; KAUPPILA, JOONAS H.; LEHENKARI, PETRI; HARRIS, KEVIN W.; SELANDER, KATRI S.

    2013-01-01

    Toll-like receptor-9 (TLR9) is an intracellular DNA receptor that is widely expressed in breast and other cancers. We previously demonstrated that low tumor TLR9 expression upon diagnosis is associated with significantly shortened disease-specific survival times in patients with triple-negative breast cancer (TNBC). There are no targeted therapies for this subgroup of patients whose prognosis is among the worst in breast cancer. Due to the previously detected in vitro anti-invasive effects of chloroquine in these cell lines, the present study aimed to investigate the in vivo effects of chloroquine against two clinical subtypes of TNBC that differ in TLR9 expression. Chloroquine suppressed matrix metalloproteinase (MMP)-2 and MMP-9 mRNA expression and protein activity, whereas MMP-13 mRNA expression and proteolytic activity were increased. Despite enhancing TLR9 mRNA expression, chloroquine suppressed TLR9 protein expression in vitro. Daily treatment of mice with intraperitoneal (i.p.) chloroquine (80 mg/kg/day) for 22 days, did not inhibit the growth of control siRNA or TLR9 siRNA MDA-MB-231 breast cancer cells. In conclusion, despite the favorable in vitro effects on TNBC invasion and viability, particularly in hypoxic conditions, chloroquine does not prevent the growth of the triple-negative MDA-MB-231 cells with high or low TLR9 expression levels in vivo. This may be explained by the activating effects of chloroquine on MMP-13 expression or by the fact that chloroquine, by suppressing TLR9 expression, permits the activation of currently unknown molecular pathways, which allow the aggressive behavior of TNBC cells with low TLR9 expression in hypoxia. PMID:24273604

  5. The Interactive Effects of Impulsivity and Negative Emotions on Adolescent Nonsuicidal Self-injury: A Latent Growth Curve Analysis.

    PubMed

    You, Jianing; Deng, Baoping; Lin, Min-Pei; Leung, Freedom

    2016-06-01

    This study employed latent growth curve analysis to evaluate the interactive effects of two specific facets of impulsivity (i.e., negative urgency [NU] and premeditation [PRE]) and negative emotions (NE) on the developmental trajectory of nonsuicidal self-injury (NSSI) among 3,453 (57% females) Chinese community adolescents. Participants completed questionnaires assessing NSSI, NU, PRE, and NE (i.e., depression, anxiety, and stress) at three waves of time. The initial levels of NE and NU significantly predicted the initial level of NSSI. Changes in NE and NU significantly predicted change in NSSI. Moreover, the initial levels of NU and PRE significantly moderated the relationship between the initial levels of NE and NSSI, such that among individuals with higher NU or less PRE, the three NE were associated with a higher level of NSSI. Additionally, among individuals with a faster increase in NU, depression and anxiety were associated with a faster increase in NSSI. These findings suggest that adolescents with trait impulsivity, especially in the form of NU, are more vulnerable to the engagement in NSSI. PMID:26436464

  6. Effects of Roundup formulations, nutrient addition, and Western mosquitofish (Gambusia affinis) on aquatic communities.

    PubMed

    Geyer, Rebecca L; Smith, Geoffrey R; Rettig, Jessica E

    2016-06-01

    Aquatic communities can be affected by herbicides, nutrient addition, and non-native fish species. We conducted a mesocosm experiment to examine the direct and interactive effects of three stressors: (1) Roundup formulations (Roundup Weed and Grass Killer(®) and Roundup Poison Ivy and Tough Brush Killer Plus(®)), (2) nutrient addition, and (3) the presence of the non-native Western mosquitofish (Gambusia affinis), on experimental pond communities. Roundup formulations had the most widespread effects on the zooplankton community, but effects varied between formulations and among taxa. The only significant effect of nutrient addition was a lowering of Daphnia abundance in the nutrient addition treatments. The abundances of Daphnia, mid-sized cladocerans, and total zooplankton were lowered by mosquitofish, but no other taxa showed significant mosquitofish effects. We found several two-way and three-way interactions among the stressors, but these varied among zooplankton taxa. Chlorophyll a levels were higher with nutrient addition but were not significantly affected by Roundup formulation or mosquitofish. Our results suggest toxicity of Roundup formulations varies among taxa, and Roundup formulations differ in their toxicity to zooplankton, but with no cascading effects on primary producers. In addition, interactions among stressors affected the zooplankton community. PMID:26944427

  7. An atomic view of additive mutational effects in a protein structure

    SciTech Connect

    Skinner, M.M.; Terwilliger, T.C.

    1996-04-01

    Substitution of a single amino acid in a protein will often lead to substantial changes in properties. If these properties could be altered in a rational way then proteins could be readily generated with functions tailored to specific uses. When amino acid substitutions are made at well-separated locations in a single protein, their effects are generally additive. Additivity of effects of amino acid substitutions is very useful because the properties of proteins with any combination of substitutions can be inferred directly from those of the proteins with single changes. It would therefore be of considerable interest to have a means of knowing whether substitutions at a particular pair of sites in a protein are likely to lead to additive effects. The structural basis for additivity of effects of mutations on protein function was examined by determining crystal structures of single and double mutants in the hydrophobic core of gene V protein. Structural effects of mutations were found to be cumulative when two mutations were made in a single protein. Additivity occurs in this case because the regions structurally affected by mutations at the two sites do not overlap even though the sites are separated by only 9 {angstrom}. Structural distortions induced by mutations in gene V protein decrease rapidly, but not isotropically, with distance from the site of mutation. It is anticipated that cases where structural and functional effects of mutations will be additive could be identified simply by examining whether the regions structurally affected by each component mutation overlap.

  8. Irradiation effect of carbon negative-ion implantation on polytetrafluoroethylene for controlling cell-adhesion property

    NASA Astrophysics Data System (ADS)

    Sommani, Piyanuch; Tsuji, Hiroshi; Kojima, Hiroyuki; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo; Takaoka, Gikan H.

    2010-10-01

    We have investigated the irradiation effect of negative-ion implantation on the changes of physical surface property of polytetrafluoroethylene (PTFE) for controlling the adhesion property of stem cells. Carbon negative ions were implanted into PTFE sheets at fluences of 1 × 10 14-1 × 10 16 ions/cm 2 and energies of 5-20 keV. Wettability and atomic bonding state including the ion-induced functional groups on the modified surfaces were investigated by water contact angle measurement and XPS analysis, respectively. An initial value of water contact angles on PTFE decreased from 104° to 88° with an increase in ion influence to 1 × 10 16 ions/cm 2, corresponding to the peak shifting of XPS C1s spectra from 292.5 eV to 285 eV with long tail on the left peak-side. The change of peak position was due to decrease of C-F 2 bonds and increase of C-C bonds with the formation of hydrophilic oxygen functional groups of OH and C dbnd O bonds after the ion implantation. After culturing rat mesenchymal stem cells (MSC) for 4 days, the cell-adhesion properties on the C --patterned PTFE were observed by fluorescent microscopy with staining the cell nuclei and their actin filament (F-actin). The clear adhesion patterning of MSCs on the PTFE was obtained at energies of 5-10 keV and a fluence of 1 × 10 15 ions/cm 2. While the sparse patterns and the uncontrollable patterns were found at a low fluence of 3 × 10 14 ions/cm 2 and a high fluence of 3 × 10 15 ions/cm 2, respectively. As a result, we could improve the surface wettability of PTFE to control the cell-adhesion property by carbon negative-ion implantation.

  9. Effect of Surface-active Additives on Physical Properties of Slurries of Vapor-process Magnesium

    NASA Technical Reports Server (NTRS)

    Pinns, Murray L

    1955-01-01

    The presence of 3 to 5 percent surface-active additive gave the lowest Brookfield apparent viscosity, plastic viscosity, and yield value that were obtained for slurry fuels containing approximately 50 percent vapor-process magnesium in JP-1 fuel. The slurries settled little and were easily remixed. A polyoxyethylene dodecyl alcohol was the most effective of 13 additives tested in reducing the Brookfield apparent viscosity and the yield value of the slurry. The seven most effective additives all had a hydroxyl group plus an ester or polyoxethylene group in the molecule. The densities of some of the slurries were measured.

  10. Additive effect of BPA and Gd-DTPA for application in accelerator-based neutron source.

    PubMed

    Yoshida, F; Yamamoto, T; Nakai, K; Zaboronok, A; Matsumura, A

    2015-12-01

    Because of its fast metabolism gadolinium as a commercial drug was not considered to be suitable for neutron capture therapy. We studied additive effect of gadolinium and boron co-administration using colony forming assay. As a result, the survival of tumor cells with additional 5 ppm of Gd-DTPA decreased to 1/10 compared to the cells with boron only. Using gadolinium to increase the effect of BNCT instead of additional X-ray irradiation might be beneficial, as such combination complies with the short-time irradiation regimen at the accelerator-based neutron source. PMID:26242560

  11. Effect of ionic additives on the elution of sodium aryl sulfonates in supercritical fluid chromatography.

    PubMed

    Zheng, J; Taylor, L T; Pinkston, J David; Mangels, M L

    2005-08-01

    Addition of a small amount of polar solvent (i.e., modifier) to CO2 in packed column supercritical fluid chromatography (SFC) has shown major improvements in both polar analyte solubility and interaction of the polar analyte with the stationary phase. Recently, the addition of an ionic component (i.e., additive) to the primary modifier by one of us has been shown to extend even further the application of SFC to polar analytes. In this work, the effect of various ionic additives on the elution of ionic compounds, such as sodium 4-dodecylbenzene sulfonate and sodium 4-octylbenene sulfonate, has been studied. The additives were lithium acetate, ammonium acetate, tetramethylammonium acetate, tetrabutylammonium acetate, and ammonium chloride dissolved in methanol. Three stationary phases with different degrees of deactivation were considered: conventional cyanopropyl, deltabond cyanopropyl, and bare silica. The effect of additive concentration and additive functionality on analyte retention was investigated. Sodium 4-dodecylbenzene sulfonate was successfully eluted using all the additives with good peak shape under isocratic/isobaric/isothermal conditions. Different additives, however, yielded different retention times and in some cases different peak shapes. PMID:16035365

  12. Global change and biological soil crusts: Effects of ultraviolet augmentation under altered precipitation regimes and nitrogen additions

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Flint, S.; Money, J.; Caldwell, M.

    2008-01-01

    Biological soil crusts (BSCs), a consortium of cyanobacteria, lichens, and mosses, are essential in most dryland ecosystems. As these organisms are relatively immobile and occur on the soil surface, they are exposed to high levels of ultraviolet (UV) radiation and atmospheric nitrogen (N) deposition, rising temperatures, and alterations in precipitation patterns. In this study, we applied treatments to three types of BSCs (early, medium, and late successional) over three time periods (spring, summer, and spring-fall). In the first year, we augmented UV and altered precipitation patterns, and in the second year, we augmented UV and N. In the first year, with average air temperatures, we saw little response to our treatments except quantum yield, which was reduced in dark BSCs during one of three sample times and in Collema BSCs two of three sample times. There was more response to UV augmentation the second year when air temperatures were above average. Declines were seen in 21% of the measured variables, including quantum yield, chlorophyll a, UV-protective pigments, nitrogenase activity, and extracellular polysaccharides. N additions had some negative effects on light and dark BSCs, including the reduction of quantum yield, ??-carotene, nitrogenase activity, scytonemin, and xanthophylls. N addition had no effects on the Collema BSCs. When N was added to samples that had received augmented UV, there were only limited effects relative to samples that received UV without N. These results indicate that the negative effect of UV and altered precipitation on BSCs will be heightened as global temperatures increase, and that as their ability to produce UV-protective pigments is compromised, physiological functioning will be impaired. N deposition will only ameliorate UV impacts in a limited number of cases. Overall, increases in UV will likely lead to lowered productivity and increased mortality in BSCs through time, which, in turn, will reduce their ability to contribute

  13. Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus.

    PubMed

    Peterson, Jennifer K; Graham, Andrea L; Elliott, Ryan J; Dobson, Andrew P; Triana Chávez, Omar

    2016-08-01

    Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses. PMID:27174360

  14. The effect of preterm birth on infant negative affect and maternal postpartum depressive symptoms: A preliminary examination in an underrepresented minority sample

    PubMed Central

    Barroso, Nicole; Hartley, Chelsey M.; Bagner, Daniel M.; Pettit, Jeremy W.

    2015-01-01

    Objective To examine the effect of preterm birth on maternal postpartum depressive symptoms and infant negative affect in an underrepresented minority sample. Method Participants were 102 mothers and their 3- to 10-month-old infants. Mothers completed the Edinburgh Postnatal Depression Scale and the Infant Behavior Questionnaire-Revised. Results Relative to normative samples, the current underrepresented minority sample of mostly Hispanics and Blacks displayed high rates of preterm birth (30%) and maternal postpartum depressive symptoms (17%). Preterm birth had a significant direct effect on postpartum depressive symptoms and infant negative affect. Additionally, there was an indirect effect of postpartum depressive symptoms on the relation between preterm birth and infant negative affect. Specifically, lower birth weight and gestational age predicted higher levels of depressive symptoms in the mother, and higher levels of depressive symptoms in the mother, in turn, predicted higher levels of infant negative affect. Conclusion Findings emphasize the importance of screening for postpartum depressive symptoms and infant negative affect among mothers and their preterm infants, especially among families from underrepresented minority backgrounds. PMID:25879520

  15. Effects of Blocking D2/D3 Receptors on Mismatch Negativity and P3a Amplitude of Initially Antipsychotic Naïve, First Episode Schizophrenia Patients

    PubMed Central

    Glenthøj, Birte Yding; Oranje, Bob

    2016-01-01

    Background: Reduced mismatch negativity and P3a amplitude have been suggested to be among the core deficits in schizophrenia since the late 1970s. Blockade of dopamine D2 receptors play an important role in the treatment of schizophrenia. In addition, there is some evidence indicating that deficits in mismatch negativity and P3a amplitude are related to increased dopaminergic activity. This is the first study investigating the effect of amisulpride, a potent D2-antagonist, on mismatch negativity and P3a amplitude in a large group of antipsychotic-naïve, first-episode schizophrenia patients. Methods: Fifty-one antipsychotic-naïve, first-episode schizophrenia patients were tested in a mismatch negativity paradigm at baseline and after 6 weeks of treatment with amisulpride. We further examined 48 age- and gender-matched controls in this paradigm. Results: At baseline, the patients showed significantly reduced P3a amplitude compared with healthy controls, but no differences in mismatch negativity. Although the treatment with amisulpride significantly improved the patients’ psychopathological (PANSS) and functional (GAF) scores, it did not influence their mismatch negativity amplitude, while also their reduced P3a amplitude persisted. Conclusion: Our findings show that antipsychotic naïve, first-episode patients with schizophrenia have normal mismatch negativity yet reduced P3a amplitude compared with healthy controls. In spite of the fact that the 6-week amisulpride treatment improved the patients both clinically and functionally, it had no effect on either mismatch negativity or P3a amplitude. This suggests that even though there is a dopaminergic involvement in global functioning and symptomatology in schizophrenia, there is no such involvement in these particular measures of early information processing. PMID:26453696

  16. The neuroendocrine response to stress under the effect of drugs: Negative synergy between amphetamine and stressors.

    PubMed

    Gómez-Román, Almudena; Ortega-Sánchez, Juan A; Rotllant, David; Gagliano, Humberto; Belda, Xavier; Delgado-Morales, Raúl; Marín-Blasco, Ignacio; Nadal, Roser; Armario, Antonio

    2016-01-01

    There have been numerous studies into the interaction between stress and addictive drugs, yet few have specifically addressed how the organism responds to stress when under the influence of psychostimulants. Thus, we studied the effects of different acute stressors (immobilization, interleukin-1β and forced swimming) in young adult male rats simultaneously exposed to amphetamine (AMPH, 4 mg/kg SC), evaluating classic biological markers. AMPH administration itself augmented the plasma hypothalamic-pituitary-adrenal (HPA) hormones, adrenocorticotropin (ACTH) and corticosterone, without affecting plasma glucose levels. By contrast, this drug dampened the peripheral HPA axis, as well as the response of glucose to the three stressors. We also found that AMPH administration completely blocked the forced swim-induced expression of the corticotropin-releasing hormone (hnCRH) and it partially reduced c-fos expression in the paraventricular nucleus of the hypothalamus (PVN). Indeed, this negative synergy in the forced swim test could even be observed with a lower dose of AMPH (1mg/kg, SC), a dose that is usually received in self-administration experiments. In conclusion, when rats that receive AMPH are subjected to stress, a negative synergy occurs that dampens the prototypic peripheral physiological response to stress and activation of the PVN. PMID:26433325

  17. What predicts negative effects of rheumatoid arthritis? A follow-up two years after diagnosis.

    PubMed

    Gåfvels, Catharina; Hägerström, Margareta; Nordmark, Birgitta; Wändell, Per

    2014-01-01

    We aimed at analyzing important predictive factors for experienced negative emotional and social effects of rheumatoid arthritis (RA) two years after diagnosis in patients aged 18-65 years. The first group included 41 participants, who had psychosocial problems (PSP) already at diagnosis, and who received an intervention by a medical social worker to improve coping capacity and social situation. The second group included 54 patients (NPSP) without such problems at diagnosis. All completed a questionnaire mapping their social situation, the Hospital Anxiety and Depression Scale (HADS), the Sense of Coherence Scale (SOC) and the General Coping Questionnaire (GCQ) at diagnosis and after 24 months. The most pronounced predictive factor for a strong impact of the disease was high scores on HADS depression scale. After 24 months, PSP participants had a more strained life situation, with higher scores on anxiety and depression and lower on SOC, in comparison with NPSP. NPSP participants improved their coping strategies regarding self-trust, cognitive revaluation, protest and intrusion, but deteriorated regarding problem focusing and social trust. PSP patients kept their initial coping strategies, except for intrusion decreasing over time, and seemed to have a more rigid coping pattern. However, the experienced negative impact of the disease increased over time in both groups despite improvement in sickness related data. Mostly influenced areas were economy, leisure time activities and social life. We conclude that psychosocial consequences of RA are more connected to emotional and social vulnerability than are RA-related clinical factors. PMID:24634809

  18. Effects of simulated interpersonal touch and trait intrinsic motivation on the error-related negativity.

    PubMed

    Tjew-A-Sin, Mandy; Tops, Mattie; Heslenfeld, Dirk J; Koole, Sander L

    2016-03-23

    The error-related negativity (ERN or Ne) is a negative event-related brain potential that peaks about 20-100ms after people perform an incorrect response in choice reaction time tasks. Prior research has shown that the ERN may be enhanced by situational and dispositional factors that promote intrinsic motivation. Building on and extending this work the authors hypothesized that simulated interpersonal touch may increase task engagement and thereby increase ERN amplitude. To test this notion, 20 participants performed a Go/No-Go task while holding a teddy bear or a same-sized cardboard box. As expected, the ERN was significantly larger when participants held a teddy bear rather than a cardboard box. This effect was most pronounced for people high (rather than low) in trait intrinsic motivation, who may depend more on intrinsically motivating task cues to maintain task engagement. These findings highlight the potential benefits of simulated interpersonal touch in stimulating attention to errors, especially among people who are intrinsically motivated. PMID:26876476

  19. Effect of tensile strain on the negative differential resistance in the WTe2 armchair nanoribbon

    NASA Astrophysics Data System (ADS)

    Ghosh, Bahniman; Gupta, Abhishek; Bishnoi, Bhupesh

    2014-04-01

    In this work, we have studied the charge transport characteristics of WTe2 armchair nanoribbon and analyzed the variation in results by applying tensile strain to the nanoribbon. Tungsten ditelluride (WTe2) is a member of the transition metal dichalcogenides family. WTe2 is orthorhombic in structure with lattice parameters a = 0.6282 nm, b = 0.3496 nm, c = 1.407 nm. We have simulated the model using first-principle density functional tight binding theory and the non-equilibrium Green’s function method to study the effect of strain on the transport characteristics. The obtained results are compared with that of the perfectly relaxed nanoribbon. We have applied uniaxial (ɛ xx) and biaxial (ɛ xx = ɛ yy) tensile strain to the nanoribbon. We present the ID-VDS characteristics, transmission spectrum and conductance for different cases. Negative differential resistance (NDR) is observed in all the cases along with a change in peak-to-valley current ratio (PVCR) and negative differential resistance region (NDRR).

  20. Negative Differential Transconductance in Silicon CMOS Quantum Well Field Effect Transistors

    NASA Astrophysics Data System (ADS)

    Naquin, Clint; Lee, Mark; Edwards, Hal; Chatterjee, Tathagata; Mathur, Guru

    2014-03-01

    Quantum well (QW) devices are potentially useful as high-speed oscillators and sensors, as well as high-density memory and multi-state logic. Historically, these devices have been built using III-V heterostructures grown epitaxially in the vertical direction. Silicon CMOS field effect transistors (FETs) that incorporate QWs through the lateral confinement of a silicon inversion layer are of particular interest due to their capability for mass production and industrial scalability. We report on the observation of negative differential transconductance (NDTC) in a set of Si CMOS QW FETs fabricated using industrial 45 nm node processing. Measurements of drain current as a function of gate voltage from 5 K to room temperature were conducted, and local current maxima and minima were observed leading to negative differential transconductance. When voltage-biasing the body terminal, NDTC appears at temperatures as high as 218 K; however, for measurements taken with the body terminal current-biased, NDTC appears at higher temperatures with peak-to-valley ratios (PVR) greater than two.

  1. Positive and negative reinforcement effects on behavior in a three-person microsociety.

    PubMed Central

    Emurian, H H; Emurian, C S; Brady, J V

    1985-01-01

    Three-person groups, either of males or of females, resided for 6 to 12 days in a continuously programmed environment. Subjects followed a behavioral program that determined the sequential and contingent relations within an inventory of activities. The program consisted of positive reinforcement days and avoidance days. During a positive reinforcement day, each work unit completed by a subject incremented a group account. The account was divided evenly among the three participants at the conclusion of the study. During a negative reinforcement day, no money was earned, and the group was assigned work unit criterion that, if completed, prevented a reduction in accumulated earnings. During negative reinforcement days, subjects made aggressive verbal responses, which differed in magnitude among the four groups. These differences were evident in several distinct behavioral measures. Performances on components of the work unit were not demonstrably affected by the reinforcement schedules in effect, although during the avoidance condition one subject stopped working and another subject's productivity declined. PMID:11536563

  2. Can reduced predation offset negative effects of sea louse parasites on chum salmon?

    PubMed

    Peacock, Stephanie J; Connors, Brendan M; Krkosek, Martin; Irvine, James R; Lewis, Mark A

    2014-02-01

    The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations. PMID:24352951

  3. Effects of positive and negative human contacts and intranasal oxytocin on cerebrospinal fluid oxytocin.

    PubMed

    Rault, Jean-Loup

    2016-07-01

    Despite the popularity of oxytocin (OT) research for its role in social behavior, the relationship between the social environment and endogenous central OT remains poorly understood. This study investigated the effects of positive and negative human contacts and intranasal OT administration on OT concentration in the cerebrospinal fluid (CSF). The pig was used as a model, with repeated CSF sampling through a spinal catheter using a within-subject design. Positive human contact led to sustained CSF OT elevation in pigs over 120min which outlasted the 15min interaction. Furthermore, the frequency of positive interactions was correlated with CSF OT increase. This provides a neurophysiological basis to positive human-animal relationships, with OT preserving bonds within but also between species through interactions. Conversely, CSF OT concentration did not vary during or after negative contact with an unfamiliar person, supporting CSF OT as a biomarker of positive valence in the human-animal relationship context. Intranasal OT administration resulted in peak CSF OT within 10min, with approximately 0.001% of the administered dose reaching the CSF. The sensitivity of the oxytocinergic system to variations in the social environment is a worthy area of investigation for its scientific and clinical implications. In particular, positive interactions result in outlasting central OT release. PMID:27032064

  4. Ocean warming ameliorates the negative effects of ocean acidification on Paracentrotus lividus larval development and settlement.

    PubMed

    García, Eliseba; Clemente, Sabrina; Hernández, José Carlos

    2015-09-01

    Ocean warming and acidification both impact marine ecosystems. All organisms have a limited body temperature range, outside of which they become functionally constrained. Beyond the absolute extremes of this range, they cannot survive. It is hypothesized that some stressors can present effects that interact with other environmental variables, such as ocean acidification (OA) that have the potential to narrow the thermal range where marine species are functional. An organism's response to ocean acidification can therefore be highly dependent on thermal conditions. This study evaluated the combined effects of predicted ocean warming conditions and acidification, on survival, development, and settlement, of the sea urchin Paracentrotus lividus. Nine combined treatments of temperature (19.0, 20.5 and 22.5 °C) and pH (8.1, 7.7 and 7.4 units) were carried out. All of the conditions tested were either within the current natural ranges of seawater pH and temperature or are within the ranges that have been predicted for the end of the century, in the sampling region (Canary Islands). Our results indicated that the negative effects of low pH on P. lividus larval development and settlement will be mitigated by a rise in seawater temperature, up to a thermotolerance threshold. Larval development and settlement performance of the sea urchin P. lividus was enhanced by a slight increase in temperature, even under lowered pH conditions. However, the species did show negative responses to the levels of ocean warming and acidification that have been predicted for the turn of the century. PMID:26275754

  5. Bidirectional-Compounding Effects of Rumination and Negative Emotion in Predicting Impulsive Behavior: Implications for Emotional Cascades.

    PubMed

    Selby, Edward A; Kranzler, Amy; Panza, Emily; Fehling, Kara B

    2016-04-01

    Influenced by chaos theory, the emotional cascade model proposes that rumination and negative emotion may promote each other in a self-amplifying cycle that increases over time. Accordingly, exponential-compounding effects may better describe the relationship between rumination and negative emotion when they occur in impulsive persons, and predict impulsive behavior. Forty-seven community and undergraduate participants who reported frequent engagement in impulsive behaviors monitored their ruminative thoughts and negative emotion multiple times daily for two weeks using digital recording devices. Hypotheses were tested using cross-lagged mixed model analyses. Findings indicated that rumination predicted subsequent elevations in rumination that lasted over extended periods of time. Rumination and negative emotion predicted increased levels of each other at subsequent assessments, and exponential functions for these associations were supported. Results also supported a synergistic effect between rumination and negative emotion, predicting larger elevations in subsequent rumination and negative emotion than when one variable alone was elevated. Finally, there were synergistic effects of rumination and negative emotion in predicting number of impulsive behaviors subsequently reported. These findings are consistent with the emotional cascade model in suggesting that momentary rumination and negative emotion progressively propagate and magnify each other over time in impulsive people, promoting impulsive behavior. PMID:25388298

  6. College Students' Intentions to Seek Help for Suicidal Ideation: Accounting for the Help-Negation Effect

    ERIC Educational Resources Information Center

    Yakunina, Elena S.; Rogers, James R.; Waehler, Charles A.; Werth, James L., Jr.

    2010-01-01

    Prior research has identified a negative association between suicidal ideation and help-seeking, a phenomenon called "help-negation." Help-negation has been documented to occur for both professional and nonprofessional sources of help. In this study help-seeking attitudes, stigma concerns, and perceptions of social support were examined as…

  7. Negative interactive effects between biochar and phosphorus fertilization on phosphorus availability and plant yield in saline sodic soil.

    PubMed

    Xu, Gang; Zhang, You; Sun, Junna; Shao, Hongbo

    2016-10-15

    Little is known about the interactive effects between biochar application and phosphorus (P) fertilization on plant growth and P uptake. For this purpose, five wheat straw biochars (produced at 25°C, 300°C, 400°C, 500°C and 600°C for 4h) with equal P (36mgkg(-1)) amount, with and without additional P fertilization (100mgkg(-1)) were applied in a pot experiment to investigate the growth of Suaeda salsa and their uptake of P from biochar and P fertilization amended saline sodic soil. Soil P fractions, dry matter yield, and plant P concentrations were determined after harvesting 90days. Our results confirmed that relatively lower pyrolysis temperature (<400°C) biochar retained P availability and increased plant growth. The plant P concentration was significantly correlated with NaHCO3-Pi (P<0.05), and NaOH-Pi (P<0.1) during early incubation time (4days) for biochar amended soil. As revealed by statistical analysis, a significant (P<0.05) negative (antagonistic) interaction occurred between biochar and P fertilization on the biomass production and plant P concentration. For plant biomass, the effects size of biochar (B), P, and their interaction followed the order of B×P (0.819)>B (0.569)≈P (0.568) based on the partial Eta squared values whereas the order changed as P (0.782)>B (0.562)>B×P (0.515) for plant P concentration. When biochar and P fertilization applied together, phosphate precipitation/sorption reaction occurred in saline sodic soil which explained the decreased plant P availability and plant yield in saline sodic soil. The negative interaction effects between biochar and P fertilization indicated limited utility value of biochar application in saline sodic soil. PMID:27328879

  8. Nitrogen Addition Altered the Effect of Belowground C Allocation on Soil Respiration in a Subtropical Forest.

    PubMed

    He, Tongxin; Wang, Qingkui; Wang, Silong; Zhang, Fangyue

    2016-01-01

    The availabilities of carbon (C) and nitrogen (N) in soil play an important role in soil carbon dioxide (CO2) emission. However, the variation in the soil respiration (Rs) and response of microbial community to the combined changes in belowground C and N inputs in forest ecosystems are not yet fully understood. Stem girdling and N addition were performed in this study to evaluate the effects of C supply and N availability on Rs and soil microbial community in a subtropical forest. The trees were girdled on 1 July 2012. Rs was monitored from July 2012 to November 2013, and soil microbial community composition was also examined by phospholipid fatty acids (PLFAs) 1 year after girdling. Results showed that Rs decreased by 40.5% with girdling alone, but N addition only did not change Rs. Interestingly, Rs decreased by 62.7% under the girdling with N addition treatment. The reducing effect of girdling and N addition on Rs differed between dormant and growing seasons. Girdling alone reduced Rs by 33.9% in the dormant season and 54.8% in the growing season compared with the control. By contrast, girdling with N addition decreased Rs by 59.5% in the dormant season and 65.4% in the growing season. Girdling and N addition significantly decreased the total and bacterial PLFAs. Moreover, the effect of N addition was greater than girdling. Both girdling and N addition treatments separated the microbial groups on the basis of the first principal component through principal component analysis compared with control. This indicated that girdling and N addition changed the soil microbial community composition. However, the effect of girdling with N addition treatment separated the microbial groups on the basis of the second principal component compared to N addition treatment, which suggested N addition altered the effect of girdling on soil microbial community composition. These results suggest that the increase in soil N availability by N deposition alters the effect of

  9. Nitrogen Addition Altered the Effect of Belowground C Allocation on Soil Respiration in a Subtropical Forest

    PubMed Central

    He, Tongxin; Wang, Qingkui; Wang, Silong; Zhang, Fangyue

    2016-01-01

    The availabilities of carbon (C) and nitrogen (N) in soil play an important role in soil carbon dioxide (CO2) emission. However, the variation in the soil respiration (Rs) and response of microbial community to the combined changes in belowground C and N inputs in forest ecosystems are not yet fully understood. Stem girdling and N addition were performed in this study to evaluate the effects of C supply and N availability on Rs and soil microbial community in a subtropical forest. The trees were girdled on 1 July 2012. Rs was monitored from July 2012 to November 2013, and soil microbial community composition was also examined by phospholipid fatty acids (PLFAs) 1 year after girdling. Results showed that Rs decreased by 40.5% with girdling alone, but N addition only did not change Rs. Interestingly, Rs decreased by 62.7% under the girdling with N addition treatment. The reducing effect of girdling and N addition on Rs differed between dormant and growing seasons. Girdling alone reduced Rs by 33.9% in the dormant season and 54.8% in the growing season compared with the control. By contrast, girdling with N addition decreased Rs by 59.5% in the dormant season and 65.4% in the growing season. Girdling and N addition significantly decreased the total and bacterial PLFAs. Moreover, the effect of N addition was greater than girdling. Both girdling and N addition treatments separated the microbial groups on the basis of the first principal component through principal component analysis compared with control. This indicated that girdling and N addition changed the soil microbial community composition. However, the effect of girdling with N addition treatment separated the microbial groups on the basis of the second principal component compared to N addition treatment, which suggested N addition altered the effect of girdling on soil microbial community composition. These results suggest that the increase in soil N availability by N deposition alters the effect of

  10. Aharonov-Bohm Effect in the Photodetachment Microscopy of Hydrogen Negative Ions in an Electric Field

    NASA Astrophysics Data System (ADS)

    Wang, Dehua

    2014-09-01

    The Aharonov-Bohm (AB) effect in the photodetachment microscopy of the H- ions in an electric field has been studied on the basis of the semiclassical theory. After the H- ion is irradiated by a laser light, they provide a coherent electron source. When the detached electron is accelerated by a uniform electric field, two trajectories of a detached electron which run from the source to the same point on the detector, will interfere with each other and lead to an interference pattern in the photodetachment microscopy. After the solenoid is electrified beside the H- ion, even though no Lorentz force acts on the electron outside the solenoid, the photodetachment microscopy interference pattern on the detector is changed with the variation in the magnetic flux enclosed by the solenoid. This is caused by the AB effect. Under certain conditions, the interference pattern reaches the macroscopic dimensions and could be observed in a direct AB effect experiment. Our study can provide some predictions for the future experimental study of the AB effect in the photodetachment microscopy of negative ions.

  11. Effect of multivitamin supplements on weight gain during pregnancy among HIV-negative women in Tanzania.

    PubMed

    Changamire, Freeman T; Mwiru, Ramadhani S; Peterson, Karen E; Msamanga, Gernard I; Spiegelman, Donna; Petraro, Paul; Urassa, Willy; Fawzi, Wafaie W

    2015-07-01

    Multivitamin supplementation has been shown to reduce the risk of low birthweight. This effect could be mediated through gestational weight gain. However, the effect of multivitamin supplementation on weight gain during pregnancy has not been fully studied. The objective of this study was to examine the effects of multivitamins on pregnancy weight gain. We enrolled 8468 HIV-negative women from Dar es Salaam, Tanzania, in a randomised, placebo-controlled trial of multivitamins on birth outcomes. Women were randomly assigned to receive either a daily oral dose of multivitamin tablets or a placebo and were weighed every 4 weeks from enrolment until the last visit before delivery. Intent-to-treat analyses were carried out to examine the effects of multivitamins on pregnancy weight gain. Multivariate linear and binomial regression models with the log-link function were used to examine the association of weight gain during pregnancy to birthweight. The overall total weight gain was 253 g (SE: 69, P: 0.0003) more, while the overall 4 weekly weight gain was 59 g greater (SE: 18, P: 0.005) among women who received multivitamins compared to placebo. Women in the lowest quartile of gestational weight gain had babies with an average birthweight of 3030 g (SD: 524), while women in the highest quartile had babies weighing 3246 g (SD: 486), on average. Prenatal multivitamin supplements increased gestational weight gain, which was a significant predictor of birthweight. PMID:23253638

  12. Influence of heterogeneous sulfur atoms on the negative differential resistance effect in polythiophene

    SciTech Connect

    Liu, Xiao Jing; Dong, Kang Liang; An, Zhong

    2014-09-07

    In this work, we have carried out theoretical investigations aiming to clarify the effects of sulfur heteroatoms on the transport characteristics in polythiophene. Sulfur atoms in polythiophene are demonstrated to influence the structure and transport process by two aspects: the electron hopping between carbon atoms on both sides of the sulfur atom as well as the effective confinement of π electrons from the sulfur atom. Based on the static Su-Schrieffer-Heeger model and the nonequilibrium Green's function formalism, we simulate the electron transportation in a metal/polythiophene/metal structure. The simulation results show that the electron hopping via sulfur atoms is responsible for the observed negative differential resistance (NDR) behavior in the I-V curves. The NDR disappears if the electron transport channels from carbon to carbon via sulfur atoms are forbidden. The weaker the effective confinement of π electrons and the electron hopping between carbon atoms on both sides of the sulfur atom are, the higher is the peak-to-valley ratio of the NDR and the wider the voltage range where the current remains at low levels. These results can help in understanding the NDR effect in polythiophene.

  13. Strong negative effects of simulated heat waves in a tropical butterfly.

    PubMed

    Fischer, Klaus; Klockmann, Michael; Reim, Elisabeth

    2014-08-15

    Climate change poses a significant challenge to all natural systems on Earth. Especially increases in extreme weather events such as heat waves have the potential to strongly affect biodiversity, though their effects are poorly understood because of a lack of empirical data. Therefore, we here explore the sensitivity of a tropical ectotherm, which are in general believed to have a low warming tolerance, to experimentally simulated climate change using ecologically realistic diurnal temperature cycles. Increasing the mean temperature permanently by 3°C had mostly minor effects on developmental traits in the butterfly Bicyclus anynana. Simulated heat waves (strongly elevated temperatures for some time though retaining the same overall temperature mean), in contrast, caused strong negative effects by prolonging development time (by up to 10%) and reducing body mass (-21%), especially when combined with reduced relative humidity. Detrimental effects were carried over into the adult stage, diminishing subsequent performance. Most strikingly, higher temperatures suppressed adult immune function (haemocytes: -54%, lysozyme activity: -32%), which may potentially change the way species interact with antagonists. Heat waves thus reduced fitness parameters by 10-25% for development time and body mass and by up to 54% for immune parameters even in this plastic and widespread butterfly, exemplifying the potentially dramatic impact of extreme weather events on biodiversity. PMID:24902752

  14. The effects of temperature and nitrogen and sulfur additions on carbon accumulation in a nutrient-poor boreal mire: Decadal effects assessed using 210Pb peat chronologies

    NASA Astrophysics Data System (ADS)

    Olid, Carolina; Nilsson, Mats B.; Eriksson, Tobias; Klaminder, Jonatan

    2014-03-01

    Boreal peatlands are a major long-term reservoir of atmospheric carbon (C) and play an important role in the global C cycle. It is unclear how C accumulation in peatlands responds to changing temperatures and nutrients (specifically, nitrogen and sulfur). In this study, we assessed how the C input rate and C accumulation rate in decadal old peat layers respond to increased air temperatures (+3.6°C) during the growing season and the annual additions of nitrogen (N) and sulfur (S) (30 and 20 kg ha-1 yr-1, respectively) over 12 years of field treatments in a boreal mire. An empirical mass balance model was applied to 210Pb-dated peat cores to evaluate changes in C inputs, C mass loss, and net C accumulation rates in response to the treatments. We found that (i) none of the treatments generated a significant effect on peat mass loss decay rates, (ii) C input rates were positively affected by N additions and negatively affected by S additions, (iii) the C accumulation rate in the uppermost (10 to 12 cm) peat was increased by N additions and decreased by S additions, and (iv) only air temperature significantly affected the main effects induced by N and S additions. Based on our findings, we argue that C accumulation rates in surface peat layers of nutrient-poor boreal mires can increase despite the predicted rise in air temperatures as long as N loads increase and acid atmospheric S remains low.

  15. A Hamiltonian Model of Dissipative Wave-particle Interactions and the Negative-mass Effect

    SciTech Connect

    A. Zhmoginov

    2011-02-07

    The effect of radiation friction is included in the Hamiltonian treatment of wave-particle interactions with autoresonant phase-locking, yielding a generalized canonical approach to the problem of dissipative dynamics near a nonlinear resonance. As an example, the negativemass eff ect exhibited by a charged particle in a pump wave and a static magnetic field is studied in the presence of the friction force due to cyclotron radiation. Particles with negative parallel masses m! are shown to transfer their kinetic energy to the pump wave, thus amplifying it. Counterintuitively, such particles also undergo stable dynamics, decreasing their transverse energy monotonically due to cyclotron cooling, whereas some of those with positive m! undergo cyclotron heating instead, extracting energy from the pump wave.

  16. Intervention Effects on Negative Affect of CPS-Referred Children: Results of a Randomized Clinical Trial

    PubMed Central

    Lind, Teresa; Bernard, Kristin; Ross, Emily; Dozier, Mary

    2014-01-01

    Exposure to early adversity places young children at risk for behavioral, physiological, and emotional dysregulation, predisposing them to a range of long-term problematic outcomes. Attachment and Biobehavioral Catch-up (ABC) is a 10-session intervention designed to enhance children’s self-regulatory capabilities by helping parents to behave in nurturing, synchronous, and non-frightening ways. The effectiveness of the intervention was assessed in a randomized clinical trial, with parents who had been referred to Child Protective Services (CPS) for allegations of maltreatment. Parent-child dyads received either the ABC intervention or a control intervention. Following the intervention, children from the ABC intervention (n = 56) expressed lower levels of negative affect during a challenging task compared to children from the control intervention (n = 61). PMID:24814751

  17. Resource-independent negative effects of foreign language on analogical problem solving.

    PubMed

    Wakebe, Toshihiro; Hidaka, Sho; Watamura, Eiichiro

    2015-02-01

    It has been shown that analogical problem solving is more difficult when a target problem is written in a foreign language than in one's native language. Possible resource-independence of this negative effect of a foreign language was investigated. After reading an analog or a filler story, participants solved a target problem written in their native or a foreign language. Those who read the problem in their native language performed a concurrent task to reduce their available processing resources. Nevertheless, they were better able to solve it than those who read the problem in a foreign language after reading the analog. This indicates that reading the problem in a foreign language decreases analogical problem-solving ability in a resource-independent manner. PMID:25588066

  18. Effects of regional hemoconcentration during LBNP on plasma volume determinations. [Lower Body Negative Pressure

    NASA Technical Reports Server (NTRS)

    Loeppky, J. A.; Kobayashi, Y.; Venters, M. D.; Luft, U. C.

    1979-01-01

    Blood samples were obtained from forearm vein or artery with indwelling cannula (1) before, (2) during the last min, and (3) about 2 min after lower body negative pressure (LBNP) in 16 experiments to determine whether plasma volume (PV) estimates were affected by regional hemoconcentration in the lower body. Total hemoglobin (THb) was estimated with the CO method prior to LBNP. Hemoglobin (Hb) and hematocrit (Hct) values from (2) gave only a 3% (87 ml) loss in PV due to LBNP, assuming no change in THb. However, Hb and Hct values from (3) showed an 11% loss in PV (313 ml). This 72% underestimation of PV loss with (2) must have resulted from the sequestration of blood and subsequent hemoconcentration in the lower body during LBNP. The effects of LBNP on PV should be estimated 1-3 min after exposure, after mixing but before extravascular fluid returns to the circulation.

  19. Giant magnetoelectric effect in negative magnetostrictive/piezoelectric/positive magnetostrictive semiring structure

    NASA Astrophysics Data System (ADS)

    Zeng, Lingyu; Zhou, Minhong; Bi, Ke; Lei, Ming

    2016-01-01

    Magnetoelectric (ME) Ni/PZT/TbFe2 and TbFe2/PZT composites with two semiring structures are prepared. The dependence between ME coupling and magnetostrictive property of the composite is discussed. Because Ni possesses negative magnetostrictive property and TbFe2 shows positive magnetostrictive property, the ME voltage coefficient of Ni/PZT/TbFe2 semiring structure is much larger than that of TbFe2/PZT. In these composites, the ME voltage coefficient increases and the resonance frequency gradually decreases with the increase of the semiring radius, showing that structural parameters are key factors to the composite properties. Due to the strong ME coupling effect, a giant ME voltage coefficient αE = 44.8 V cm-1 Oe-1 is obtained. This approach opens a way for the design of ME composites with giant ME voltage coefficient.

  20. Novel variants in GNAI3 associated with auriculocondylar syndrome strengthen a common dominant negative effect.

    PubMed

    Romanelli Tavares, Vanessa L; Gordon, Christopher T; Zechi-Ceide, Roseli M; Kokitsu-Nakata, Nancy Mizue; Voisin, Norine; Tan, Tiong Y; Heggie, Andrew A; Vendramini-Pittoli, Siulan; Propst, Evan J; Papsin, Blake C; Torres, Tatiana T; Buermans, Henk; Capelo, Luciane Portas; den Dunnen, Johan T; Guion-Almeida, Maria L; Lyonnet, Stanislas; Amiel, Jeanne; Passos-Bueno, Maria Rita

    2015-04-01

    Auriculocondylar syndrome is a rare craniofacial disorder comprising core features of micrognathia, condyle dysplasia and question mark ear. Causative variants have been identified in PLCB4, GNAI3 and EDN1, which are predicted to function within the EDN1-EDNRA pathway during early pharyngeal arch patterning. To date, two GNAI3 variants in three families have been reported. Here we report three novel GNAI3 variants, one segregating with affected members in a family previously linked to 1p21.1-q23.3 and two de novo variants in simplex cases. Two variants occur in known functional motifs, the G1 and G4 boxes, and the third variant is one amino acid outside of the G1 box. Structural modeling shows that all five altered GNAI3 residues identified to date cluster in a region involved in GDP/GTP binding. We hypothesize that all GNAI3 variants lead to dominant negative effects. PMID:25026904

  1. Novel variants in GNAI3 associated with auriculocondylar syndrome strengthen a common dominant negative effect

    PubMed Central

    Romanelli Tavares, Vanessa L; Gordon, Christopher T; Zechi-Ceide, Roseli M; Kokitsu-Nakata, Nancy Mizue; Voisin, Norine; Tan, Tiong Y; Heggie, Andrew A; Vendramini-Pittoli, Siulan; Propst, Evan J; Papsin, Blake C; Torres, Tatiana T; Buermans, Henk; Capelo, Luciane Portas; den Dunnen, Johan T; Guion-Almeida, Maria L; Lyonnet, Stanislas; Amiel, Jeanne; Passos-Bueno, Maria Rita

    2015-01-01

    Auriculocondylar syndrome is a rare craniofacial disorder comprising core features of micrognathia, condyle dysplasia and question mark ear. Causative variants have been identified in PLCB4, GNAI3 and EDN1, which are predicted to function within the EDN1–EDNRA pathway during early pharyngeal arch patterning. To date, two GNAI3 variants in three families have been reported. Here we report three novel GNAI3 variants, one segregating with affected members in a family previously linked to 1p21.1-q23.3 and two de novo variants in simplex cases. Two variants occur in known functional motifs, the G1 and G4 boxes, and the third variant is one amino acid outside of the G1 box. Structural modeling shows that all five altered GNAI3 residues identified to date cluster in a region involved in GDP/GTP binding. We hypothesize that all GNAI3 variants lead to dominant negative effects. PMID:25026904

  2. Intervention effects on negative affect of CPS-referred children: results of a randomized clinical trial.

    PubMed

    Lind, Teresa; Bernard, Kristin; Ross, Emily; Dozier, Mary

    2014-09-01

    Exposure to early adversity places young children at risk for behavioral, physiological, and emotional dysregulation, predisposing them to a range of long-term problematic outcomes. Attachment and Biobehavioral Catch-up (ABC) is a 10-session intervention designed to enhance children's self-regulatory capabilities by helping parents to behave in nurturing, synchronous, and non-frightening ways. The effectiveness of the intervention was assessed in a randomized clinical trial, with parents who had been referred to Child Protective Services (CPS) for allegations of maltreatment. Parent-child dyads received either the ABC intervention or a control intervention. Following the intervention, children from the ABC intervention (n=56) expressed lower levels of negative affect during a challenging task compared to children from the control intervention (n=61). PMID:24814751

  3. Dynamic Jahn-Teller Effect in Negatively Charged Nitrogen-Vacancy Center in Diamond

    NASA Astrophysics Data System (ADS)

    Abtew, Tesfaye; Zhang, Peihong

    2011-03-01

    The negatively charged nitrogen-vacancy (NV) center in diamond has attracted much research interest recently owing to its desirable optical properties and long spin coherent lifetime. The ground state of NV- center has a 3 A2 symmetry, which can be optically excited, to a 3 E state. The excited state is orbitally degenerate therefore should experience either static or dynamic Jahn-Teller (JT) effects. We use accurate first-principles methods to study structural and electronic properties of the NV- center in diamond both in the ground and excited states. Our results indicate that the excited state of the NV- center is indeed a dynamic JT system. We acknowledge the Center for Computational Research at the University at Buffalo, SUNY. This work is supported by the National Science Foundation under Grant No. DMR-0946404 and by the Department of Energy under GrantNo. DE-SC0002623.

  4. Effect of different feed ingredients and additives on IPEC-J2 cells challenged with an enterotoxigenic Escherichia coli strain.

    PubMed

    Spitzer, F; Speiser, S; Vahjen, W; Zentek, J

    2016-08-01

    The intestinal porcine epithelial cell line IPEC-J2 was used as an in vitro model to assess effects of additives on the adhesion and cell toxic effects of a F4-positive (ETEC) and a F4-negative Escherichia coli (DSM 2840) strain. Bacterial adhesion was examined using flow cytometry in IPEC-J2 cells infected with bacteria stained with 5,6-carboxymethyl fluorescein diacetate succinimidyl ester. Measurement of transepithelial electrical resistance (TEER) was performed to characterize the impact on IPEC-J2 monolayer integrity. The feed additives were prepared as aqueous extract and tested in different dilutions and incubation times. The F4-positive ETEC strain had a high adhesion to IPEC-J2 cells and reduced TEER shortly after the in vitro infection. The nonpathogenic E. coli strain DSM 2840 showed only low adhesion capacity and no TEER impairment. Infection with ETEC with added test extracts showed a reduction of bacterial adhesion to IPEC-J2 cells by an autolyzed yeast product (p < 0.05). Bovine colostrum, an additive containing thyme extract and an organic acid mix did not interfere with the ETEC adherence. The TEER decrease of the IPEC-J2 monolayer after ETEC infection was not affected by the added substances. In conclusion, interference with epithelial adhesion might be a protective mechanism of the tested yeast extract, indicating that the cell culture model might be suitable as screening tool to complement in vivo challenge trials with piglets. PMID:26275434

  5. Effect of lapatinib on the development of estrogen receptor-negative mammary tumors in mice.

    PubMed

    Strecker, Tracy E; Shen, Qiang; Zhang, Yun; Hill, Jamal L; Li, Yuxin; Wang, Chunyu; Kim, Hee-Tae; Gilmer, Tona M; Sexton, Krystal R; Hilsenbeck, Susan G; Osborne, C Kent; Brown, Powel H

    2009-01-21

    Lapatinib, a selective orally available inhibitor of epidermal growth factor receptor (EGFR) and ErbB2 receptor tyrosine kinases, is a promising agent for the treatment of breast cancer. We examined the effect of lapatinib on the development of mammary tumors in MMTV-erbB2 transgenic mice, which express wild-type ErbB2 under the control of the mouse mammary tumor virus promoter and spontaneously develop estrogen receptor (ER)-negative and ErbB2-positive mammary tumors by 14 months of age. Mice were treated from age 3 months to age 15 months with vehicle (n = 17) or lapatinib (30 or 75 mg/kg body weight; n = 16 mice per group) by oral gavage twice daily (6 d/wk). All statistical tests were two-sided. By 328 days after the start of treatment, all 17 (100%) of the vehicle-treated mice vs five (31%) of the 16 mice treated with high-dose lapatinib developed mammary tumors (P < .001). Among MMTV-erbB2 mice treated for 5 months (n = 20 mice per group), those treated with lapatinib had fewer premalignant lesions and noninvasive cancers in their mammary glands than those treated with vehicle (P = .02). Lapatinib also effectively blocked epidermal growth factor-induced signaling through the EGFR and ErbB2 receptors, suppressed cyclin D1 and epiregulin mRNA expression, and stimulated p27 mRNA expression in human mammary epithelial cells and in mammary epithelial cells from mice treated for 5 months with high-dose lapatinib. Thus, cyclin D1, epiregulin, and p27 may represent useful biomarkers of lapatinib response in patients. These data suggest that lapatinib is a promising agent for the prevention of ER-negative breast cancer. PMID:19141783

  6. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

    PubMed

    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. PMID:25381837

  7. Superlensing effect for surface acoustic waves in a pillar-based phononic crystal with negative refractive index

    SciTech Connect

    Addouche, Mahmoud Al-Lethawe, Mohammed A. Choujaa, Abdelkrim Khelif, Abdelkrim

    2014-07-14

    We demonstrate super resolution imaging for surface acoustic waves using a phononic structure displaying negative refractive index. This phononic structure is made of a monolithic square lattice of cylindrical pillars standing on a semi-infinite medium. The pillars act as acoustic resonator and induce a surface propagating wave with unusual dispersion. We found, under specific geometrical parameters, one propagating mode that exhibits negative refraction effect with negative effective index close to −1. Furthermore, a flat lens with finite number of pillars is designed to allow the focusing of an acoustic point source into an image with a resolution of (λ)/3 , overcoming the Rayleigh diffraction limit.

  8. Additive effects of word frequency and stimulus quality: the influence of trial history and data transformations.

    PubMed

    Balota, David A; Aschenbrenner, Andrew J; Yap, Melvin J

    2013-09-01

    A counterintuitive and theoretically important pattern of results in the visual word recognition literature is that both word frequency and stimulus quality produce large but additive effects in lexical decision performance. The additive nature of these effects has recently been called into question by Masson and Kliegl (in press), who used linear mixed effects modeling to provide evidence that the additive effects were actually being driven by previous trial history. Because Masson and Kliegl also included semantic priming as a factor in their study and recent evidence has shown that semantic priming can moderate the additivity of word frequency and stimulus quality (Scaltritti, Balota, & Peressotti, 2012), we reanalyzed data from 3 published studies to determine if previous trial history moderated the additive pattern when semantic priming was not also manipulated. The results indicated that previous trial history did not influence the joint influence of word frequency and stimulus quality. More important, and independent of Masson and Kliegl's conclusions, we also show how a common transformation used in linear mixed effects analyses to normalize the residuals can systematically alter the way in which two variables combine to influence performance. Specifically, using transformed, rather than raw reaction times, consistently produces more underadditive patterns. PMID:23565779

  9. Effects of additives on volume change on melting, surface tension, and viscosity of liquid aluminum oxide

    NASA Technical Reports Server (NTRS)

    Bates, J. L.; Rasmussen, J. J.

    1972-01-01

    The effects of various oxide additives on the volume change on melting, the surface tension, and the viscosity of liquid Al2O3 were studied. Additives of Sm2O3, MgO, and Y2O3 which form solid solutions, compounds, and multiphase solids with Al2O3 were studied. A review of the property data for Al2O3 and Al2O3 containing oxide additives is presented. Oxide additives to Al2O3 reduce the volume change on melting and with the exception of SiO2 lower the viscosity; surface tensions change with oxide additives, but changes vary with different container material. Viscosity and volume change on melting appeared to be significantly more important for studying the properties of liquid oxides than surface tension. Supercooling of 270 K of yttrium aluminum garnet was observed.

  10. Cross-Cultural Generalizability of Year in School Effects: Negative Effects of Acceleration and Positive Effects of Retention on Academic Self-Concept

    ERIC Educational Resources Information Center

    Marsh, Herbert W.

    2016-01-01

    Given that the Big-Fish-Little-Pond-Effect, the negative effect of school-average achievement on academic self-concept, is one of the most robust findings in educational psychology (Marsh, Seaton et al., 2007), this research extends the theoretical model, based on social comparison theory, to study relative year in school effects (e.g., being 1…

  11. Endurance training prevents negative effects of the hypoxia mimetic dimethyloxalylglycine on cardiac and skeletal muscle function.

    PubMed

    Favier, Francois B; Britto, Florian A; Ponçon, Benjamin; Begue, Gwenaelle; Chabi, Beatrice; Reboul, Cyril; Meyer, Gregory; Py, Guillaume

    2016-02-15

    Hypoxic preconditioning is a promising strategy to prevent hypoxia-induced damages to several tissues. This effect is related to prior stabilization of the hypoxia-inducible factor-1α via inhibition of the prolyl-hydroxylases (PHDs), which are responsible for its degradation under normoxia. Although PHD inhibition has been shown to increase endurance performance in rodents, potential side effects of such a therapy have not been explored. Here, we investigated the effects of 1 wk of dimethyloxalylglycine (DMOG) treatment (150 mg/kg) on exercise capacity, as well as on cardiac and skeletal muscle function in sedentary and endurance-trained rats. DMOG improved maximal aerobic velocity and endurance in both sedentary and trained rats. This effect was associated with an increase in red blood cells without significant alteration of skeletal muscle contractile properties. In sedentary rats, DMOG treatment resulted in enhanced left ventricle (LV) weight together with impairment in diastolic function, LV relaxation, and pulse pressure. Moreover, DMOG decreased maximal oxygen uptake (state 3) of isolated mitochondria from skeletal muscle. Importantly, endurance training reversed the negative effects of DMOG treatment on cardiac function and restored maximal mitochondrial oxygen uptake to the level of sedentary placebo-treated rats. In conclusion, we provide here evidence that the PHD inhibitor DMOG has detrimental influence on myocardial and mitochondrial function in healthy rats. However, one may suppose that the deleterious influence of PHD inhibition would be potentiated in patients with already poor physical condition. Therefore, the present results prompt us to take into consideration the potential side effects of PHD inhibitors when administrated to patients. PMID:26679609

  12. Tools to assess negative symptoms in schizophrenia.

    PubMed

    Kane, John M

    2013-06-01

    Although effective treatments for negative symptoms are currently limited, clinicians still need to assess and monitor them because of their impact on patient functioning. Further, documenting patients' negative symptoms provides a complete clinical record that the clinician can use to make systematic and careful treatment decisions. Several tools for assessing negative symptoms in schizophrenia are available, including the Clinical Global Impression scale (CGI), the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Negative Symptoms (SANS), the 16-item Negative Symptoms Assessment (NSA-16), and the Schedule for Deficit Syndrome (SDS). Additionally, newer instruments are in development-the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptoms Scale (BNSS)-and are yielding promising results. This overview outlines these assessment tools so that clinicians can measure negative symptom severity and track treatment response for their patients with schizophrenia. PMID:23842020

  13. Experimental confirmation of temperature dependent negative capacitance in ferroelectric field effect transistor

    NASA Astrophysics Data System (ADS)

    Salvatore, Giovanni A.; Rusu, Alexandru; Ionescu, Adrian M.

    2012-04-01

    In this paper, we report the basic design conditions and the experimental confirmation of a temperature dependent negative capacitance (NC) effect in a ferroelectric field-effect-transistor (Fe-FET). We find that the internal voltage amplification peaks of a metal-ferroelectric-metal-insulator-semiconductor (MFMIS) structure are correlated with the S-shape of the polarization versus electrical field characteristics. The internal voltage amplification is responsible for the subthreshold swing reduction in a Fe-FET; this effect cancels out when the temperature is increased close to the Curie temperature because of the narrowing of the NC region and because of the saturation of the amplification. A counter-clockwise rotation of the P-V loops with an associated increase of the dP/dV slope with the temperature is reported, which corresponds to an increase of the overall ferroelectric capacitance with the temperature. Finally, we theoretically and experimentally demonstrate that an optimum temperature exists at which the amplification gets its maximum.

  14. Regulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery

    SciTech Connect

    Xiao, Xingcheng; Zhou, Weidong; Kim, Youngnam; Ryu, Ill; Gu, Meng; Wang, Chong M.; Liu, Gao; Liu, Zhongyi; Gao, Huajian

    2015-03-01

    Si is an attractive negative electrode material for lithium ion batteries due to its high specifi c capacity (≈3600 mAh g –1 ). However, the huge volume swelling and shrinking during cycling, which mimics a breathing effect at the material/electrode/cell level, leads to several coupled issues including fracture of Si particles, unstable solid electrolyte interphase, and low Coulombic effi ciency. In this work, the regulation of the breathing effect is reported by using Si–C yolk–shell nanocomposite which has been well-developed by other researchers. The focus is on understanding how the nanoscaled materials design impacts the mechanical and electrochemical response at electrode level. For the fi rst time, it is possible to observe one order of magnitude of reduction on breathing effect at the electrode level during cycling: the electrode thickness variation reduced down to 10%, comparing with 100% in the electrode with Si nanoparticles as active materials. The Si–C yolk–shell nanocomposite electrode exhibits excellent capacity retention and high cycle effi ciency. In situ transmission electron microscopy and fi nite element simulations consistently reveals that the dramatically enhanced performance is associated with the regulated breathing of the Si in the new composite, therefore the suppression of the overall electrode expansion.

  15. Climate change enhances the negative effects of predation risk on an intermediate consumer.

    PubMed

    Miller, Luke P; Matassa, Catherine M; Trussell, Geoffrey C

    2014-12-01

    Predators are a major source of stress in natural systems because their prey must balance the benefits of feeding with the risk of being eaten. Although this 'fear' of being eaten often drives the organization and dynamics of many natural systems, we know little about how such risk effects will be altered by climate change. Here, we examined the interactive consequences of predator avoidance and projected climate warming in a three-level rocky intertidal food chain. We found that both predation risk and increased air and sea temperatures suppressed the foraging of prey in the middle trophic level, suggesting that warming may further enhance the top-down control of predators on communities. Prey growth efficiency, which measures the efficiency of energy transfer between trophic levels, became negative when prey were subjected to predation risk and warming. Thus, the combined effects of these stressors may represent an important tipping point for individual fitness and the efficiency of energy transfer in natural food chains. In contrast, we detected no adverse effects of warming on the top predator and the basal resources. Hence, the consequences of projected warming may be particularly challenging for intermediate consumers residing in food chains where risk dominates predator-prey interactions. PMID:24947942

  16. Effect of dimethyl sulfoxide addition on ultrasonic degradation of methylene blue

    NASA Astrophysics Data System (ADS)

    Shimakage, Kaho; Kobayashi, Daisuke; Naya, Masakazu; Matsumoto, Hideyuki; Shimada, Yuichiro; Otake, Katsuto; Shono, Atsushi

    2016-07-01

    The ultrasonic degradation of methylene blue was carried out in the absence and presence of dimethyl sulfoxide (DMSO) as a radical scavenger for various frequencies, and the effects of DMSO addition on the degradation rate constant estimated by assuming first-order kinetics were investigated. The degradation reaction rate decreased with DMSO addition, and hydroxyl radicals were observed to play important roles in the degradation of methylene blue. However, the degradation reaction did not stop with DMSO addition, and the degradation rate constant in the presence of DMSO was not affected by ultrasonic frequency.

  17. Effects of different additives on the performance of spray dryer system during incineration process.

    PubMed

    Wey, M Y; Peng, C Y; Wu, H Y; Chiang, B C; Liu, Z S

    2002-06-01

    The spray dryer system was conventionally employed to remove the SOx, NOx, and HCl in the flue gas. However, the removal efficiency of acid gas in the practical incineration flue gas, which contains dust, heavy metals, and acid gas itself, was seldom mentioned in the literature. The alkaline sorbents possess large specific surface that was a main factor on the adsorption of heavy metals and acid gas. Therefore, the primary objective of this study was focused on the effect of different additives on the removal efficiency of acid gas and heavy metals (Cr, Cd and Pb). The mass and element size distribution of heavy metals in fly ash under different additives were also investigated. The results indicated that the removal efficiency of HCl in the spray dryer system was higher than 97.8%. The effects of additives on the removal efficiency of HCl, however, were undistinguished. In the desulfurization process, the highest removal efficiency was 71.3% when the additive of amorphous SiO2 was added in the spray dryer system. The removal efficiency was 66.0% with the additive of CaCl2 and 63.1% without any additives, respectively. It was also found that the spray dryer system could decrease the concentration of metal in fly ash but increase the amount of fly ash. In addition, amorphous SiO2 in the alkaline sorbent tended to increase the adsorption of heavy metal on reactant, because it could enhance the dispersion of alkaline sorbent. PMID:12118621

  18. Glucocorticoid and antibiotic effects on hepatic microcirculation and associated host responses in lethal gram-negative bacteremia.

    PubMed

    Balis, J U; Paterson, J F; Shelley, S A; Larson, C H; Fareed, J; Gerber, L I

    1979-01-01

    Liver changes and associated host responses were evaluated in four groups of male rats, weighing 300 +/- 20 gm., which received intravenous injection of 2.2 times 10(9) live Escherichia coli. This bolus was given either without additional treatment (group A) or prior to the following regimens: intramuscular injection of gentamicin sulfate, 5 mg. per kg. (group B); intravenous injection of methylprednisolone sodium succinate, 40 mg. per kg. (group C); and intramuscular injection of gentamicin immediately after methylprednisolone sodium succinate treatment (group D). Rats given injections of saline or methylprednisolone sodium succinate served as controls. Survival rates at 10 and 20 hours were 25 per cent and 4 per cent for group A; 44 per cent and 28 per cent for group B; 94 per cent and 70 per cent for group C; 98 per cent and 98 per cent for group D, respectively. In rats of groups A and B, killed at 1, 2, 4, and 6 hours, progressive liver changes included intravascular sequestration of rapidly degranulating leukocytes, fibrinous deposits, and platelet aggregates in sinusoids as well as in spaces of Disse adjacent to subendothelial collagen, and extensive Kupffer cell disruption in association with severe midzonal necrosis. These alterations were accompanied by progressive hypoglycemia and elevations of serum enzymes, glutamic pyruvic transaminase, lactate dehydrogenase, and glutamic oxaloacetic transaminase. Hematologic studies revealed that E. coli bacteremia results in rapid leukopenia and disseminated intravascular coagulation primarily due to activation of the intrinsic coagulation pathway. All above reactions were delayed and markedly reduced in rats treated with methylprednisolone sodium succinate. The results indicate that antibiotic treatment of lethal, Gram-negative bacteremia is effective only in conjunction with early steroid treatment. The protective effects of glucocorticoids on the liver microcirculation and polymorphonuclear leukocytes appear to

  19. Widespread non-additive and interaction effects within HLA loci modulate the risk of autoimmune diseases

    PubMed Central

    Lenz, Tobias L.; Deutsch, Aaron J.; Han, Buhm; Hu, Xinli; Okada, Yukinori; Eyre, Stephen; Knapp, Michael; Zhernakova, Alexandra; Huizinga, Tom W.J.; Abecasis, Goncalo; Becker, Jessica; Boeckxstaens, Guy E.; Chen, Wei-Min; Franke, Andre; Gladman, Dafna D.; Gockel, Ines; Gutierrez-Achury, Javier; Martin, Javier; Nair, Rajan P.; Nöthen, Markus M.; Onengut-Gumuscu, Suna; Rahman, Proton; Rantapää-Dahlqvist, Solbritt; Stuart, Philip E.; Tsoi, Lam C.; Van Heel, David A.; Worthington, Jane; Wouters, Mira M.; Klareskog, Lars; Elder, James T.; Gregersen, Peter K.; Schumacher, Johannes; Rich, Stephen S.; Wijmenga, Cisca; Sunyaev, Shamil R.; de Bakker, Paul I.W.; Raychaudhuri, Soumya

    2015-01-01

    Human leukocyte antigen (HLA) genes confer strong risk for autoimmune diseases on a log-additive scale. Here we speculated that differences in autoantigen binding repertoires between a heterozygote’s two expressed HLA variants may result in additional non-additive risk effects. We tested non-additive disease contributions of classical HLA alleles in patients and matched controls for five common autoimmune diseases: rheumatoid arthritis (RA, Ncases=5,337), type 1 diabetes (T1D, Ncases=5,567), psoriasis vulgaris (Ncases=3,089), idiopathic achalasia (Ncases=727), and celiac disease (Ncases=11,115). In four out of five diseases, we observed highly significant non-additive dominance effects (RA: P=2.5×1012; T1D: P=2.4×10−10; psoriasis: P=5.9×10−6; celiac disease: P=1.2×10−87). In three of these diseases, the dominance effects were explained by interactions between specific classical HLA alleles (RA: P=1.8×10−3; T1D: P=8.6×1027; celiac disease: P=6.0×10−100). These interactions generally increased disease risk and explained moderate but significant fractions of phenotypic variance (RA: 1.4%, T1D: 4.0%, and celiac disease: 4.1%, beyond a simple additive model). PMID:26258845

  20. [Effects of superphosphate addition on NH3 and greenhouse gas emissions during vegetable waste composting].

    PubMed

    Yang, Yan; Sun, Qin-ping; Li, Ni; Liu, Chun-sheng; Li, Ji-jin; Liu, Ben-sheng; Zou, Guo-yuan

    2015-01-01

    To study the effects of superphosphate (SP) on the NH, and greenhouse gas emissions, vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls, five vegetable waste mixtures (0.77 m3 each) were treated with different amounts of the SP additive, namely, 5%, 10%, 15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting. Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH3 emission by 4.0% to 16.7%. The total greenhouse gas emissions (CO2-eq) of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases. The amount of NH3 (CO2-eq) from each treatment ranged from 59.90 kg . t-1 to 81.58 kg . t-1; NH3(CO2-eq) accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer. PMID:25985667

  1. Effect of a phytogenic feed additive on the susceptibility of Onchorhynchus mykiss to Aeromonas salmonicida.

    PubMed

    Menanteau-Ledouble, S; Krauss, I; Santos, G; Fibi, S; Weber, B; El-Matbouli, M

    2015-06-29

    In recent years, feed additives have increasingly been adopted by the aquaculture industry. These supplements not only offer an alternative to antibiotics but have also been linked to enhanced growth performance. However, the literature is still limited and provides contradictory information on their effectiveness. This is mainly due to the wide variety of available products and their complex mechanisms of action. Phytogenic feed additives have been shown to have antimicrobial effects and can improve growth performance. In the present study, we investigated the susceptibility of several fish pathogenic bacteria to a phytogenic essential oil product in vitro. In addition, we determined the protective effect of a commercial phytogenic feed additive containing oregano, anis and citrus oils on the resistance of rainbow trout Oncorhynchus mykiss to infection by Aeromonas salmonicida. The bacterium was administered through 3 different routes: intra-peritoneal injection, immersion in a bacterial solution and cohabitation with infected fish. Mortality rates were significantly lower in infected rainbow trout that had received the feed additive: the overall mortality rate across all routes of infection was 18% in fish fed a diet containing the additive compared to 37% in fish that received unsupplemented feed. The route of infection also significantly impacted mortality, with average mortality rates of 60, 17.5 and 5% for intra-peritoneal injection, immersion and cohabitation, respectively. In general, fish were better protected against infection by immersion than infection by injection. PMID:26119300

  2. Magnetic Flux Concentrations in Stratified Turbulent Plasma Due to Negative Effective Magnetic Pressure Instability

    NASA Astrophysics Data System (ADS)

    Jabbari, Sarah

    2015-08-01

    We study a system of a highly stratified turbulent plasma. In such a system, when the magnetic Reynolds number is large enough and there is a background field of suitable strength, a new effect will play role in con- centrating magnetic fields such that it leads to the formation of magnetic spots and bipolar regions. This effect is due to the fact that the turbu- lent pressure is suppressed by the large-scale magnetic field, which adds a negative term to the total mean-field (effective) pressure. This leads to an instability, which is known as the negative effective magnetic pressure instability (NEMPI). Direct numerical simulations (DNS) of isothermally forced turbulence have shown that NEMPI leads to the formation of spots in the presence of an imposed field. Our main aim now is to use NEMPI to explain the formation of active regions and sunspots. To achieve this goal, we need to move progressively to more realistic models. Here we extend our model by allowing the magnetic field to be generated by a dy- namo. A dynamo plays an important role in solar activity. Therefore, it is of interest to investigate NEMPI in the presence of dynamo-generated magnetic fields. Mean-field simulations (MFS) of such systems in spheri- cal geometry have shown how these two instabilities work in concert. In fact NEMPI will be activated as long as the strength of the magnetic field generated by the dynamo is in a proper range (for more detail see Jab- bari et al. 2013). In our new study, we use DNS to investigate a similar system. The turbulence is forced in the entire spherical shell, but the forc- ing is made helical in the lower 30% of the shell, similar to the model of Mitra et al. (2014). We perform simulations using the Pencil Code for different density contrasts and other input parameters. We applied ver- tical field boundary conditions in the r direction. The results show that, when the stratification is high enough, intense bipolar regions form and as time passes, they expand

  3. Synergistic effects of the chitosan addition and polysaccharides-EPS on the formation of anaerobic granules.

    PubMed

    Hudayah, N; Suraraksa, B; Chaiprasert, P

    2016-11-01

    Concomitant early granulation with chitosan addition under a syntroph-specific substrate and enhancement of extracellular polymeric substances (EPS) production were aimed at to build anaerobic granules with high syntrophic activities in a short period. Two laboratory-scale upflow anaerobic sludge blanket reactors were operated as control (R1) and chitosan addition (R2) reactors during early granulation (phase 1). Chitosan decreased the negativity of microbial surface charges (zeta potential) to -10.5 mV on day 58 which led to increases in average diameter sizes, nuclei and granule ratio of approximately 115 µm, 55.1% and 8.2%, respectively. While zeta potential in R1 slightly changed, this resulted in less microbial aggregation. Although microbial aggregation in R2 was rapidly triggered by chitosan addition during phase 1, its structure was clumpy with rough surface due to lack of EPS. Substrate switching to glucose increased polysaccharides-EPS during phase 2 which was synergistically improved on the structural characteristics of microbial aggregate in R2, that is, more spherical and compact, with a smoother surface. Rapid-growth microorganism was also boosted, which then dominated the outer layer of the aggregate. The Archaea clumps were observed at a deeper layer and were surrounded by Eubacteria, presumably acetogens, indicating a syntrophic relationship due to substrate association between these microbial groups. PMID:27553457

  4. The effects of Na/K additives and flyash on NO reduction in a SNCR process.

    PubMed

    Hao, Jiangtao; Yu, Wei; Lu, Ping; Zhang, Yufei; Zhu, Xiuming

    2015-03-01

    An experimental study of Na/K additives and flyash on NO reduction during the selective non-catalytic reduction (SNCR) process were carried out in an entrained flow reactor (EFR). The effects of reaction temperature (Tr), water vapor, Na/K additives (NaCl, KCl, Na2CO3) and flyash characteristics on NO reduction were analyzed. The results indicated that NO removal efficiency shows a pattern of increasing first and decreasing later with the increase of the temperature at Tr=850-1150°C. Water vapor can improve the performance of NO reduction, and the NO reduction of 70.5% was obtained while the flue gas containing 4% water vapor at 950°C. Na/K additives have a significant promoting effect on NO reduction and widen the SNCR temperature window, the promoting effect of the test additives is ordered as Na2CO3>KCl>NaCl. NO removal efficiency with 125ppm Na2CO3 and 4% water vapor can reach up to 84.9% at the optimal reaction temperature. The additive concentration has no significant effects on NO reduction while its concentration is above 50ppm. Addition of circulating fluidized combustion (CFB) flyash deteriorates NO reduction significantly. However, CFB flyash and Na/K additives will get a coupling effect on NO reduction during the SNCR process, and the best NO reduction can reach 72.3% while feeding Na2CO3-impregnated CFB flyash at 125ppm Na2CO3 and Tr=950°C. PMID:25532766

  5. Effects of In and Ni Addition on Microstructure of Sn-58Bi Solder Joint

    NASA Astrophysics Data System (ADS)

    Mokhtari, Omid; Nishikawa, Hiroshi

    2014-11-01

    In this study, the effect of adding 0.5 wt.% and 1 wt.% In and Ni to Sn-58Bi solder on intermetallic compound (IMC) layers at the interface and the microstructure of the solder alloys were investigated during reflow and thermal aging by scanning electron microscopy and electron probe micro-analysis. The results showed that the addition of minor elements was not effective in suppressing the IMC growth during the reflow; however, the addition of 0.5 wt.% In and Ni was effective in suppressing the IMC layer growth during thermal aging. The thickening kinetics of the total IMC layer was analyzed by plotting the mean thickness versus the aging time on log-log coordinates, and the results showed the transition point from grain boundary diffusion control to a volume diffusion control mechanism. The results also showed that the minor addition of In can significantly suppress the coarsening of the Bi phase.

  6. Additivity of semantic and phonological effects: Evidence from speech production in Mandarin.

    PubMed

    Zhu, Xuebing; Zhang, Qingfang; Damian, Markus F

    2016-11-01

    A number of previous studies using picture-word interference (PWI) tasks conducted with speakers of Western languages have demonstrated non-additive effects of semantic and form overlap between pictures and words, which may indicate underlying non-discrete processing stages in lexical retrieval. The present study used Mandarin speakers and presented Chinese characters as distractors. In two experiments, we crossed semantic relatedness with "pure" phonological (i.e., orthographically unrelated) relatedness and found statistically additive effects. In a third experiment, semantic relatedness was crossed with orthographic overlap (phonological overlap was avoided), and once again we found an additive pattern. The results are discussed with regard to possible cross-linguistic differences between Western and non-Western languages in terms of phonological encoding, as well as concerning the locus of relatedness effects in PWI tasks. PMID:26730809

  7. Mechanisms and modeling of the effects of additives on the nitrogen oxides emission

    NASA Technical Reports Server (NTRS)

    Kundu, Krishna P.; Nguyen, Hung Lee; Kang, M. Paul

    1991-01-01

    A theoretical study on the emission of the oxides of nitrogen in the combustion of hydrocarbons is presented. The current understanding of the mechanisms and the rate parameters for gas phase reactions were used to calculate the NO(x) emission. The possible effects of different chemical species on thermal NO(x), on a long time scale were discussed. The mixing of these additives at various stages of combustion were considered and NO(x) concentrations were calculated; effects of temperatures were also considered. The chemicals such as hydrocarbons, H2, CH3OH, NH3, and other nitrogen species were chosen as additives in this discussion. Results of these calculations can be used to evaluate the effects of these additives on the NO(x) emission in the industrial combustion system.

  8. Effect of coagulase-negative staphylococci on somatic cell count in Dutch dairy herds.

    PubMed

    Sampimon, Otlis; van den Borne, Bart Hp; Santman-Berends, Inge; Barkema, Herman W; Lam, Theo

    2010-08-01

    The effect was quantified of coagulase-negative staphylococci (CNS) intramammary infections on quarter- and cow-level somatic cell count (SCC) and on bulk milk somatic cell count (BMSCC) in different BMSCC cohorts in Dutch dairy herds. Two datasets were used for this purpose. In the first dataset, on 49 randomly selected dairy farms a total of 4220 quarter milk samples of 1072 cows were collected of all cows and heifers with a test-day SCC 250 000 and 150 000 cells/ml, respectively, and of 25% of cows and heifers below these thresholds. In the second dataset, on 39 selected dairy farms a total of 8329 quarter milk samples of 2115 cows were collected of all cows with a test-day SCC 250 000 cells/ml following two consecutive SCC <250 000 cells/ml, and of heifers using the same SCC criteria but with a threshold of 150 000 cells/ml. These cows and heifers were defined as new high SCC. In both datasets, CNS was the most frequently isolated pathogen, 11% in the first dataset and 12% in the second dataset. In both datasets, quarters with CNS IMI had a lower SCC than quarters infected with major pathogens, and a higher SCC than culture-negative quarters. The same was found for SCC at cow level. Coagulase-negative staphylococci were more often found in quarters with SCC 200 000 cells/ml in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a higher BMSCC. Prevalence of CNS in cows and heifers with a high SCC was higher in dairy farms with a BMSCC <150 000 cells/ml compared with dairy farms with a medium or high BMSCC: 30, 19 and 18%, respectively. This indicates that CNS IMI as a cause of subclinical mastitis is relatively more important in dairy farms with a low BMSCC and may become a point of attention in udder health management on that type of farm. PMID:20450528

  9. Anaerobic co-digestion of acetate-rich with lignin-rich wastewater and the effect of hydrotalcite addition.

    PubMed

    Rodriguez-Chiang, Lourdes; Llorca, Jordi; Dahl, Olli

    2016-10-01

    The methane potential and biodegradability of different ratios of acetate and lignin-rich effluents from a neutral sulfite semi-chemical (NSSC) pulp mill were investigated. Results showed ultimate methane yields up to 333±5mLCH4/gCOD when only acetate-rich substrate was added and subsequently lower methane potentials of 192±4mLCH4/gCOD when the lignin fraction was increased. The presence of lignin showed a linear decay in methane production, resulting in a 41% decrease in methane when the lignin-rich feed had a 30% increase. A negative linear correlation between lignin content and biodegradability was also observed. Furthermore, the effect of hydrotalcite (HT) addition was evaluated and showed increase in methane potential of up to 8%, a faster production rate and higher soluble lignin removal (7-12% higher). Chemical oxygen demand (COD) removal efficiencies between 64 and 83% were obtained for all samples. PMID:27347802

  10. The additive and interactive effects of parenting and temperament in predicting adjustment problems of children of divorce.

    PubMed

    Lengua, L J; Wolchik, S A; Sandler, I N; West, S G

    2000-06-01

    Investigated the interaction between parenting and temperament in predicting adjustment problems in children of divorce. The study utilized a sample of 231 mothers and children, 9 to 12 years old, who had experienced divorce within the previous 2 years. Both mothers' and children's reports on parenting, temperament, and adjustment variables were obtained and combined to create cross-reporter measures of the variables. Parenting and temperament were directly and independently related to outcomes consistent with an additive model of their effects. Significant interactions indicated that parental rejection was more strongly related to adjustment problems for children low in positive emotionality, and inconsistent discipline was more strongly related to adjustment problems for children high in impulsivity. These findings suggest that children who are high in impulsivity may be at greater risk for developing problems, whereas positive emotionality may operate as a protective factor, decreasing the risk of adjustment problems in response to negative parenting. PMID:10802832

  11. Clastogenic effects of food additive citric acid in human peripheral lymphocytes

    PubMed Central

    Ünal, Fatma; Yüzbaşıoğlu, Deniz; Aksoy, Hüseyin

    2008-01-01

    Clastogenic properties of the food additive citric acid, commonly used as an antioxidant, were analysed in human peripheral blood lymphocytes. Citric acid induced a significant increase of chromosomal aberrations (CAs) at all the concentrations and treatment periods tested. Citric acid significantly decreased mitotic index (MI) at 100 and 200 μg ml−1 concentrations at 24 h, and in all concentrations at 48 h. However, it did not decrease the replication index (RI) significantly. Citric acid also significantly increased sister chromatid exchanges (SCEs) at 100 and 200 μg ml−1 concentrations at 24 h, and in all concentrations at 48 h. This chemical significantly increased the micronuclei frequency (MN) compared to the negative control. It also decreased the cytokinesis-block proliferation index (CBPI), but this result was not statistically significant. PMID:19002851

  12. Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments.

    PubMed

    Yan, Ying; Yi, Grace Y

    2016-07-01

    Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods. PMID:26328545

  13. Bioremediation of high organic load lagoon sediments: compost addition and priming effects.

    PubMed

    d'Errico, G; Giovannelli, D; Montano, C; Milanovic, V; Ciani, M; Manini, E

    2013-03-01

    Lagoons are often affected by eutrophication phenomena, due to their shallow nature, high productivity, weak hydrodynamism and anthropic exploitation. Bioremediation techniques have been widely used in the treatment of chemical pollution; however, no information is available on the use of bioremediation of organic-rich sediments. In the present study, we investigated the priming effects following compost addition to organic-rich lagoon sediments, and the effects of this compost addition on degradation and cycling of organic detritus, transfer of organic matter to higher trophic levels, and in situ prokaryotic community structure. There was a positive response to treatment, particularly during the first days after compost addition. The compost had a stimulating effect on degradation activity of the prokaryotic community. This occurred despite an increase in available organic matter, as the community was more efficient at removing it. These data are supported by the prokaryotic community structure analysis, which revealed no changes in the in situ community following compost addition. This priming effect enhancement through compost addition represents an efficient method to treat organic-rich sediments. PMID:23273326

  14. Genomic prediction of growth in pigs based on a model including additive and dominance effects.

    PubMed

    Lopes, M S; Bastiaansen, J W M; Janss, L; Knol, E F; Bovenhuis, H

    2016-06-01

    Independent of whether prediction is based on pedigree or genomic information, the focus of animal breeders has been on additive genetic effects or 'breeding values'. However, when predicting phenotypes rather than breeding values of an animal, models that account for both additive and dominance effects might be more accurate. Our aim with this study was to compare the accuracy of predicting phenotypes using a model that accounts for only additive effects (MA) and a model that accounts for both additive and dominance effects simultaneously (MAD). Lifetime daily gain (DG) was evaluated in three pig populations (1424 Pietrain, 2023 Landrace, and 2157 Large White). Animals were genotyped using the Illumina SNP60K Beadchip and assigned to either a training data set to estimate the genetic parameters and SNP effects, or to a validation data set to assess the prediction accuracy. Models MA and MAD applied random regression on SNP genotypes and were implemented in the program Bayz. The additive heritability of DG across the three populations and the two models was very similar at approximately 0.26. The proportion of phenotypic variance explained by dominance effects ranged from 0.04 (Large White) to 0.11 (Pietrain), indicating that importance of dominance might be breed-specific. Prediction accuracies were higher when predicting phenotypes using total genetic values (sum of breeding values and dominance deviations) from the MAD model compared to using breeding values from both MA and MAD models. The highest increase in accuracy (from 0.195 to 0.222) was observed in the Pietrain, and the lowest in Large White (from 0.354 to 0.359). Predicting phenotypes using total genetic values instead of breeding values in purebred data improved prediction accuracy and reduced the bias of genomic predictions. Additional benefit of the method is expected when applied to predict crossbred phenotypes, where dominance levels are expected to be higher. PMID:26676611

  15. Radiation graft modification of ethylene-propylene rubber—II. Effect of additives

    NASA Astrophysics Data System (ADS)

    Haddadi-Asl, V.; Burford, R. P.; Garnett, J. L.

    1995-02-01

    The effect of multifunctional acrylic additives including TMPTA, PEGDA and PGTA on the radiation grafting of hydrophilic vinyl monomers onto ethylene—propylene elastomer (EPM rubbers) was studied. This work centres upon gamma irradiation-induced grafting of acrylamide (AAm), N-vinyl-2-pyrrolidone (NVP), 2-hydroxyethyl methacrylate (HEMA) and acrylonitrile (AN) onto EPM rubber by the simultaneous method. Water proved to be an effective solvent but methanol lowered grafting. Sulphuric acid was detrimental to both homopolymerisation and grafting, a result consistent with the theory proposed for the role of this additive in polymer grafting systems.

  16. Nicotine content and abstinence state have different effects on subjective ratings of positive versus negative reinforcement from smoking

    PubMed Central

    Lindsey, Kimberly P.; Bracken, Bethany K.; MacLean, Robert R.; Ryan, Elizabeth T.; Lukas, Scott E.; Frederick, Blaise deB.

    2012-01-01

    Despite the well-known adverse health consequences of smoking, approximately 20% of US adults smoke tobacco cigarettes. Much of the research on smoking reinforcement and the maintenance of tobacco smoking behavior has focused on nicotine; however, a number of other non-nicotine factors are likely to influence the reinforcing effects of smoked tobacco. A growing number of studies suggest that non-nicotine factors, through many pairings with nicotine, are partially responsible for the reinforcing effect of smoking. Additionally, both clinical studies and preclinical advances in our understanding of nicotinic receptor regulation suggest that abstinence from smoking may influence smoking reinforcement. These experiments were conducted for 2 reasons: to validate a MRI-compatible cigarette smoking device; and to simultaneously investigate the impact of nicotine, smoking-associated conditioned reinforcers, and smoking abstinence state on subjective ratings of smoking reinforcement. Participants smoked nicotine and placebo cigarettes through an fMRI compatible device in an overnight-abstinent state or in a nonabstinent state, after having smoked a cigarette 25 minutes prior. Outcome measures were within-subject changes in physiology and subjective ratings of craving and drug effect during the smoking of nicotine or placebo cigarettes on different days in both abstinence states. Cigarette type (nicotine vs. placebo) had a significant effect on positive subjective ratings of smoking reinforcement (“High”, “Like Drug”, “Feel Drug”; nicotine>placebo). In contrast, abstinence state was found to have significant effects on both positive and negative ratings of smoking reinforcement (“Crave”, “Anxiety”, “Irritability”; abstinence > nonabstinence). Interaction effects between abstinence and nicotine provide clues about the importance of neuroadaptive mechanisms operating in dependence, as well as the impact of conditioned reinforcement on subjective ratings

  17. Synergistic and Additive Effect of Oregano Essential Oil and Biological Silver Nanoparticles against Multidrug-Resistant Bacterial Strains.

    PubMed

    Scandorieiro, Sara; de Camargo, Larissa C; Lancheros, Cesar A C; Yamada-Ogatta, Sueli F; Nakamura, Celso V; de Oliveira, Admilton G; Andrade, Célia G T J; Duran, Nelson; Nakazato, Gerson; Kobayashi, Renata K T

    2016-01-01

    Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare) essential oil (OEO) and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP), produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all 17 strains tested, with minimal inhibitory concentrations (MIC) ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 μM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min), while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM) revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA) cells exposed to three different treatments (OEO, bio-AgNP and combination of the two), which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds showed very low

  18. Synergistic and Additive Effect of Oregano Essential Oil and Biological Silver Nanoparticles against Multidrug-Resistant Bacterial Strains

    PubMed Central

    Scandorieiro, Sara; de Camargo, Larissa C.; Lancheros, Cesar A. C.; Yamada-Ogatta, Sueli F.; Nakamura, Celso V.; de Oliveira, Admilton G.; Andrade, Célia G. T. J.; Duran, Nelson; Nakazato, Gerson; Kobayashi, Renata K. T.

    2016-01-01

    Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare) essential oil (OEO) and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP), produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all 17 strains tested, with minimal inhibitory concentrations (MIC) ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 μM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min), while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM) revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA) cells exposed to three different treatments (OEO, bio-AgNP and combination of the two), which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds showed very low

  19. Haemodynamic effects of negative pressure wound therapy when using a rigid barrier to prevent heart rupture.

    PubMed

    Lindstedt, Sandra; Ingemansson, Richard; Malmsjo, Malin

    2011-08-01

    Right ventricular heart rupture is a devastating complication associated with negative pressure wound therapy (NPWT) in cardiac surgery. The use of a rigid barrier has been suggested to offer protection against this lethal complication by preventing the heart from being drawn up and damaged by the sharp sternum bone edges. The aim of this study was to investigate the haemodynamic effects of placing a rigid barrier over the heart to protect it from rupture during NPWT. Eight pigs underwent median sternotomy followed by NPWT at --70 and --120 mmHg, using foam, with or without a rigid plastic disc between the heart and the sternal edges. The heart frequency, cardiac output, mean systemic arterial pressure, mean pulmonary artery pressure, central venous pressure and left atrial pressure were recorded. Cardiac output was not affected by NPWT, regardless of whether a rigid barrier was used. Heart frequency decreased during NPWT without a disc, and showed a tendency towards a decrease when using a rigid disc. The blood pressure decreased during NPWT without a disc, and showed only a tendency towards a decrease when a disc was inserted between the heart and the sternum. In conclusion, the results of this haemodynamic study show that a rigid disc can safely be placed over the heart during NPWT, to prevent heart rupture. The haemodynamic effects of NPWT in sternotomy wounds are slightly reduced by the presence of the rigid disc. PMID:21585658

  20. Dose-related effect of alcohol on mismatch negativity and reaction time performance.

    PubMed

    Jääskeläinen, I P; Pekkonen, E; Alho, K; Sinclair, J D; Sillanaukee, P; Näätänen, R

    1995-01-01

    In a recent study, the mismatch negativity (MMN) component of auditory event-related potential, elicited by occasional frequency changes in a repetitive tone, was strongly attenuated by a low dosage of alcohol. We investigated the phenomenon in nine subjects with two different dosages of ethanol (0.35 and 0.55 g/kg), and with two magnitudes of frequency changes (5% and 10%), in a single-blind, placebo-controlled paradigm. Ethanol had no observable effect on the N1 and P2 deflections, nor on the reaction time to frequency changes measured in a separate session. However, the MMN was attenuated after administration of the larger dosage of alcohol, suggesting impaired preconscious processing of stimulus features outside the scope of attention. The results support the view according to which the automatic functions of human information processing are more sensitive than the controlled functions to the detrimental effects of alcohol. The fact that the MMN suppression was stronger when stimulus deviation was smaller indicates that at relatively low blood alcohol concentrations the detection of small deviations is especially hampered. PMID:8590608

  1. AMPK is a negative regulator of the Warburg Effect and suppresses tumor growth in vivo

    PubMed Central

    Faubert, Brandon; Boily, Gino; Izreig, Said; Griss, Takla; Samborska, Bozena; Dong, Zhifeng; Dupuy, Fanny; Chambers, Christopher; Fuerth, Benjamin J.; Viollet, Benoit; Mamer, Orval A.; Avizonis, Daina; DeBerardinis, Ralph J.; Siegel, Peter M.; Jones, Russell G.

    2012-01-01

    Summary AMPK is a metabolic sensor that helps maintain cellular energy homeostasis. Despite evidence linking AMPK with tumor suppressor functions, the role of AMPK in tumorigenesis and tumor metabolism is unknown. Here we show that AMPK negatively regulates aerobic glycolysis (the Warburg effect) in cancer cells, and suppresses tumor growth in vivo. Genetic ablation of the α1 catalytic subunit of AMPK accelerates Myc-induced lymphomagenesis. Inactivation of AMPKα in both transformed and non-transformed cells promotes a metabolic shift to aerobic glycolysis, increased allocation of glucose carbon into lipids, and biomass accumulation. These metabolic effects require normoxic stabilization of the hypoxia-inducible factor-1α (HIF-1α), as silencing HIF-1α reverses the shift to aerobic glycolysis and the biosynthetic and proliferative advantages conferred by reduced AMPKα signaling. Together our findings suggest that AMPK activity opposes tumor development, and its loss fosters tumor progression in part by regulating cellular metabolic pathways that support cell growth and proliferation. PMID:23274086

  2. The generalist Inga subnuda subsp. luschnathiana (Fabaceae): negative effect of floral visitors on reproductive success?

    PubMed

    Avila, R; Pinheiro, M; Sazima, M

    2015-05-01

    Inga species are characterised by generalist or mixed pollination system. However, this feature does not enhance reproductive rates in species with very low fruit set under natural conditions. Some ecological and genetic factors are associated with this feature, and to test the effect of massive visits on pollination success in Inga subnuda subsp. luschnathiana, we studied the efficacy of polyads deposited on stigmas of flowers isolated from visitors and polyads exposed to visitors. The proportion of polyads fixed in stigmas decreased after exposure to visitors (24 h) in comparison to stigmas isolated from visitors (hummingbirds, bees, wasps, hawkmoths and bats), and fruit set was very low. Furthermore, nectar production, sugar composition and other floral biology traits were evaluated. Increased nectar production, sugar availability and sucrose dominance during the night indicates adaptation to nocturnal visitors and supports their role as main pollinators; although the brush-flower morphology, time of anthesis, nectar dynamics and chemical composition also allow daytime visitors. Thus the species is an important resource for a diverse group of floral visitors. We conclude that excess visits (diurnal and nocturnal) are responsible for the decrease in fixed polyads in stigmas of I. subnuda subsp. luschnathiana flowers, thus contributing, with others factors, to its low fruit set. Therefore, the generalist pollination system does not result in reproductive advantages because the low fruit set in natural conditions could be the result of a negative effect of visitors/pollinators. PMID:25488371

  3. The effects of negative emotions on sensory perception: fear but not anger decreases tactile sensitivity

    PubMed Central

    Kelley, Nicholas J.; Schmeichel, Brandon J.

    2014-01-01

    Emotions and sensory perceptions are closely intertwined. Of the five senses, sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances sensory perception, including tactile sensitivity. A competing hypothesis based on research on peripheral psychophysiology predicts that fear should decrease tactile sensitivity. Two experiments that induced negative emotional states and measured two-point discrimination ability at the fingertip found that fear reduces tactile sensitivity relative to anger or a neutral control condition (Studies 1 and 2). These findings did not appear to be driven by participants’ naïve beliefs about the influence of emotions on touch (Study 3). The results represent the first evidence of the causal impact of emotional states on tactile sensitivity, are consistent with prior evidence for the peripheral physiological effects of fear, and offer novel empirical grounds for developing and advancing theories of emotional influences on sensory perception. PMID:25202299

  4. Size effects on negative thermal expansion in cubic ScF3

    NASA Astrophysics Data System (ADS)

    Yang, C.; Tong, P.; Lin, J. C.; Guo, X. G.; Zhang, K.; Wang, M.; Wu, Y.; Lin, S.; Huang, P. C.; Xu, W.; Song, W. H.; Sun, Y. P.

    2016-07-01

    Scandium trifluoride (ScF3), adopting a cubic ReO3-type structure at ambient pressure, undergoes a pronounced negative thermal expansion (NTE) over a wide range of temperatures (10 K-1100 K). Here, we report the size effects on the NTE properties of ScF3. The magnitude of NTE is reduced with diminishing the crystal size. As revealed by the specific heat measurement, the low-energy phonon vibrations which account for the NTE behavior are stiffened as the crystal size decreases. With decreasing the crystal size, the peaks in high-energy X-ray pair distribution function (PDF) become broad, which cannot be illuminated by local symmetry breaking. Instead, the broadened PDF peaks are strongly indicative of enhanced atomic displacements which are suggested to be responsible for the stiffening of NTE-related lattice vibrations. The present study suggests that the NTE properties of ReO3-type and other open-framework materials can be effectively adjusted by controlling the crystal size.

  5. Nutraceutical intervention reverses the negative effects of blood from aged rats on stem cells.

    PubMed

    Bickford, Paula C; Kaneko, Yuji; Grimmig, Bethany; Pappas, Colleen; Small, Brent; Sanberg, Cyndy D; Sanberg, Paul R; Tan, Jun; Douglas Shytle, R

    2015-10-01

    Aging is associated with a decline in function in many of the stem cell niches of the body. An emerging body of literature suggests that one of the reasons for this decline in function is due to cell non-autonomous influences on the niche from the body. For example, studies using the technique of parabiosis have demonstrated a negative influence of blood from aged mice on muscle satellite cells and neurogenesis in young mice. We examined if we could reverse this effect of aged serum on stem cell proliferation by treating aged rats with NT-020, a dietary supplement containing blueberry, green tea, vitamin D3, and carnosine that has been shown to increase neurogenesis in aged rats. Young and aged rats were administered either control NIH-31 diet or one supplemented with NT-020 for 28 days, and serum was collected upon euthanasia. The serum was used in cultures of both rat hippocampal neural progenitor cells (NPCs) and rat bone marrow-derived mesenchymal stem cells (MSCs). Serum from aged rats significantly reduced cell proliferation as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2'-deoxyuridine (BrdU) assays in both NPCs and MSCs. Serum from aged rats treated with NT-020 was not different from serum from young rats. Therefore, NT-020 rescued the effect of serum from aged rats to reduce stem cell proliferation. PMID:26410618

  6. Ovariectomy does not exacerbate the negative effects of sleep deprivation on synaptic plasticity in rats.

    PubMed

    Hajali, Vahid; Sheibani, Vahid; Mahani, Saeed E; Hajializadeh, Zahra; Shabani, Mohammad; Aliabadi, Hamzeh P; Saadati, Hakimeh; Esmaeilpour, Khadijeh

    2015-05-15

    In our previous work, we found that female rats showed more cognitive impairment than male rats following 72h sleep deprivation (SD). Here, we compared the intact female with ovariectomized (OVX) rats to assess the potential modulatory effects of endogenous female sex hormones against the 48h SD-induced cognitive and synaptic modulations. The multiple platform method was applied for SD induction and spatial performances were determined using Morris water maze (MWM) task. Early longterm potentiation (E-LTP) was evaluated in area CA1 of the hippocampus and PCR and western blotting assays were employed to assess hippocampal BDNF gene and protein expression. To reveal any influence of sleep loss on stress level, we also measured the plasma corticosterone levels of animals. Regardless of reproductive status, SD significantly impaired short-term memory and LTP, but did not significantly change the BDNF expression in the hippocampus. The corticosterone levels were decreased in both intact and OVX female rats following SD. These findings suggest that depletion of female sex steroid hormones does not lead to any heightened responsivity of female animals to the negative effects of SD on cognitive and synaptic functions. PMID:25748255

  7. Bound Na(+) is a Negative Effecter for Thrombin-Substrate Stereospecific Complex Formation.

    PubMed

    Kurisaki, Ikuo; Takayanagi, Masayoshi; Nagaoka, Masataka

    2016-05-26

    Thrombin has been studied as a paradigmatic protein of Na(+)-activated allosteric enzymes. Earlier structural studies suggest that Na(+)-binding promotes the thrombin-substrate association reaction. However, it is still elusive because (1) the structural change, driven by Na(+)-binding, is as small as the thermal fluctuation, and (2) the bound Na(+) is close to Asp189 in the primary substrate binding pocket (S1-pocket), possibly preventing substrate access via repulsive interaction. It still remains a matter of debate whether Na(+)-binding actually promotes the reaction. To solve this problem, we examined the effect of Na(+) on the reaction by employing molecular dynamics (MD) simulations. By executing independent 210 MD simulations of apo and holo systems, we obtained 80 and 26 trajectories undergoing substrate access to S1-pocket, respectively. Interestingly, Na(+)-binding results in a 3-fold reduction of the substrate access. Furthermore, we examined works for the substrate access and release, and found that Na(+)-binding is disadvantageous for the presence of the substrate in the S1-pocket. These observations provide the insight that the bound Na(+) is essentially a negative effecter in thrombin-substrate stereospecific complex formation. The insight rationalizes an enigmatic feature of thrombin, relatively low Na(+)-binding affinity. This is essential to reduce the disadvantage of Na(+)-binding in the substrate-binding. PMID:27164318

  8. PINK1 Is a Negative Regulator of Growth and the Warburg Effect in Glioblastoma.

    PubMed

    Agnihotri, Sameer; Golbourn, Brian; Huang, Xi; Remke, Marc; Younger, Susan; Cairns, Rob A; Chalil, Alan; Smith, Christian A; Krumholtz, Stacey-Lynn; Mackenzie, Danielle; Rakopoulos, Patricia; Ramaswamy, Vijay; Taccone, Michael S; Mischel, Paul S; Fuller, Gregory N; Hawkins, Cynthia; Stanford, William L; Taylor, Michael D; Zadeh, Gelareh; Rutka, James T

    2016-08-15

    Proliferating cancer cells are characterized by high rates of glycolysis, lactate production, and altered mitochondrial metabolism. This metabolic reprogramming provides important metabolites for proliferation of tumor cells, including glioblastoma. These biological processes, however, generate oxidative stress that must be balanced through detoxification of reactive oxygen species (ROS). Using an unbiased retroviral loss-of-function screen in nontransformed human astrocytes, we demonstrate that mitochondrial PTEN-induced kinase 1 (PINK1) is a regulator of the Warburg effect and negative regulator of glioblastoma growth. We report that loss of PINK1 contributes to the Warburg effect through ROS-dependent stabilization of hypoxia-inducible factor-1A and reduced pyruvate kinase muscle isozyme 2 activity, both key regulators of aerobic glycolysis. Mechanistically, PINK1 suppresses ROS and tumor growth through FOXO3a, a master regulator of oxidative stress and superoxide dismutase 2. These findings highlight the importance of PINK1 and ROS balance in normal and tumor cells. PINK1 loss was observed in a significant number of human brain tumors including glioblastoma (n > 900) and correlated with poor patient survival. PINK1 overexpression attenuates in vivo glioblastoma growth in orthotopic mouse xenograft models and a transgenic glioblastoma model in Drosophila Cancer Res; 76(16); 4708-19. ©2016 AACR. PMID:27325644

  9. The emotion potential of simple sentences: additive or interactive effects of nouns and adjectives?

    PubMed Central

    Lüdtke, Jana; Jacobs, Arthur M.

    2015-01-01

    The vast majority of studies on affective processes in reading focus on single words. The most robust finding is a processing advantage for positively valenced words, which has been replicated in the rare studies investigating effects of affective features of words during sentence or story comprehension. Here we were interested in how the different valences of words in a sentence influence its processing and supralexical affective evaluation. Using a sentence verification task we investigated how comprehension of simple declarative sentences containing a noun and an adjective depends on the valences of both words. The results are in line with the assumed general processing advantage for positive words. We also observed a clear interaction effect, as can be expected from the affective priming literature: sentences with emotionally congruent words (e.g., The grandpa is clever) were verified faster than sentences containing emotionally incongruent words (e.g., The grandpa is lonely). The priming effect was most prominent for sentences with positive words suggesting that both, early processing as well as later meaning integration and situation model construction, is modulated by affective processing. In a second rating task we investigated how the emotion potential of supralexical units depends on word valence. The simplest hypothesis predicts that the supralexical affective structure is a linear combination of the valences of the nouns and adjectives (Bestgen, 1994). Overall, our results do not support this: The observed clear interaction effect on ratings indicate that especially negative adjectives dominated supralexical evaluation, i.e., a sort of negativity bias in sentence evaluation. Future models of sentence processing thus should take interactive affective effects into account. PMID:26321975

  10. Computational modeling of the negative priming effect based on inhibition patterns and working memory

    PubMed Central

    Chung, Dongil; Raz, Amir; Lee, Jaewon; Jeong, Jaeseung

    2013-01-01

    Negative priming (NP), slowing down of the response for target stimuli that have been previously exposed, but ignored, has been reported in multiple psychological paradigms including the Stroop task. Although NP likely results from the interplay of selective attention, episodic memory retrieval, working memory, and inhibition mechanisms, a comprehensive theoretical account of NP is currently unavailable. This lacuna may result from the complexity of stimuli combinations in NP. Thus, we aimed to investigate the presence of different degrees of the NP effect according to prime-probe combinations within a classic Stroop task. We recorded reaction times (RTs) from 66 healthy participants during Stroop task performance and examined three different NP subtypes, defined according to the type of the Stroop probe in prime-probe pairs. Our findings show significant RT differences among NP subtypes that are putatively due to the presence of differential disinhibition, i.e., release from inhibition. Among the several potential origins for differential subtypes of NP, we investigated the involvement of selective attention and/or working memory using a parallel distributed processing (PDP) model (employing selective attention only) and a modified PDP model with working memory (PDP-WM, employing both selective attention and working memory). Our findings demonstrate that, unlike the conventional PDP model, the PDP-WM successfully simulates different levels of NP effects that closely follow the behavioral data. This outcome suggests that working memory engages in the re-accumulation of the evidence for target response and induces differential NP effects. Our computational model complements earlier efforts and may pave the road to further insights into an integrated theoretical account of complex NP effects. PMID:24312046

  11. Additive and interactive effects of stimulus degradation: no challenge for CDP+.

    PubMed

    Ziegler, Johannes C; Perry, Conrad; Zorzi, Marco

    2009-01-01

    S. O'Malley and D. Besner (2008) showed that additive effects of stimulus degradation and word frequency in reading aloud occur in the presence of nonwords but not in pure word lists. They argued that this dissociation presents a major challenge to interactive computational models of reading aloud and claimed that no currently implemented model is able to simulate additive effects in these conditions. In the current article, it is shown that the connectionist dual process model (CDP+) can simulate these effects because its nonlexical route is thresholded. The authors present a series of simulations showing that CDP+ can not only simulate the precise dissociation observed by O'Malley and Besner but more generally can produce additive effects for a wide range of parameter combinations and different sets of items. The nonlexical route of CDP+ was not modified post hoc to deal with the effects of stimulus quality, but it had been thresholded for principled reasons before it was known that these effects existed. Together, the effects of stimulus quality on word frequency do not challenge CDP+ but rather provide unexpected support for its architecture and processing dynamics. PMID:19210104

  12. Effects of additives on lipase immobilization in microemulsion-based organogels.

    PubMed

    Zhang, Wei-Wei; Wang, Na; Zhang, Ling; Wu, Wan-Xia; Hu, Cheng-Li; Yu, Xiao-Qi

    2014-03-01

    An inexpensive, facile, and environmentally benign method was developed to improve the activity and stability of Candida rugosa lipase (triacylglycerol acylhydrolase) immobilized on microemulsion-based organogels (CRL MBGs) via the addition of additives during immobilization. The additives used were polyethylene glycol (PEG) or polysaccharides. This study is the first report on the effect of additives in CRL MBGs. Among the tested additives, PEG produced the most improvement in the immobilized CRL, enhancing its stability in organic solvents (specifically polar solvents). The results of circular dichroism and fluorescence spectra experiments indicated that exposure of the acidic CRL to electronegative additives in the buffer, such as polyethylenimine and the electropositive surfactant cetyltrimethylammonium bromide, may change the lipase secondary structure, ultimately causing enzyme inactivation. However, sodium bis(2-ethylhexyl)sulfosuccinate and PEG 2000 had minimal effects on the secondary structure of CRL. The CRL MBGs containing PEG 2000 demonstrated remarkable retention of their catalytic activity during the recycling test. No significant changes in enzymatic activity were observed, even after nine runs, and 90% of the original yield was maintained after 15 cycles. PMID:24497044

  13. Positive and negative effective mass of classical particles in oscillatory and static fields.

    PubMed

    Dodin, I Y; Fisch, N J

    2008-03-01

    A classical particle oscillating in an arbitrary high-frequency or static field effectively exhibits a modified rest mass m(eff) derived from the particle averaged Lagrangian. Relativistic ponderomotive and diamagnetic forces, as well as magnetic drifts, are obtained from the m(eff) dependence on the guiding center location and velocity. The effective mass is not necessarily positive and can result in backward acceleration when an additional perturbation force is applied. As an example, adiabatic dynamics with m||>0 and m||<0 is demonstrated for a wave-driven particle along a dc magnetic field, m|| being the effective longitudinal mass derived from m(eff). Multiple energy states are realized in this case, yielding up to three branches of m|| for a given magnetic moment and parallel velocity. PMID:18517528

  14. The effect of lactic acid bacterial starter culture and chemical additives on wilted rice straw silage.

    PubMed

    Wang, Yan-Su; Shi, Wei; Huang, Lin-Ting; Ding, Cheng-Long; Dai, Chuan-Chao

    2016-04-01

    Lactic acid bacteria (LAB) are suitable for rice straw silage fermentation, but have been studied rarely, and rice straw as raw material for ensiling is difficult because of its disadvantages, such as low nutrition for microbial activities and low abundances of natural populations of LAB. So we investigated the effect of application of LAB and chemical additives on the fermentation quality and microbial community of wilted rice straw silage. Treatment with chemical additives increased the concentrations of crude protein (CP), water soluble carbohydrate (WSC), acetic acid and lactic acid, reduced the concentrations of acid detergent fiber (ADF) and neutral detergent fiber (NDF), but did not effectively inhibit the growth of spoilage organisms. Inoculation with LABs did not improve the nutritional value of the silage because of poor growth of LABs in wilted rice straw. Inoculation with LAB and addition of chemical materials improved the quality of silage similar to the effects of addition of chemical materials alone. Growth of aerobic and facultatively anaerobic bacteria was inhibited by this mixed treatment and the LAB gradually dominated the microbial community. In summary, the fermentation quality of wilted rice straw silage had improved by addition of LAB and chemical materials. PMID:26429595

  15. The Blazhko Effect and Additional Excited Modes in RR Lyrae Stars

    NASA Astrophysics Data System (ADS)

    Benkő, J. M.; Szabó, R.

    2015-08-01

    Recent photometric space missions, such as CoRoT and Kepler, revealed that many RR Lyrae stars pulsate—beyond their main radial pulsation mode—in low-amplitude modes. Space data seem to indicate a clear trend that, namely, overtone (RRc) stars and modulated fundamental (RRab) RR Lyrae stars ubiquitously show additional modes, while non-Blazhko RRab stars never do. Two Kepler stars (V350 Lyr and KIC 7021124), however, apparently seemed to break this rule: they were classified as non-Blazhko RRab stars showing additional modes. We processed Kepler pixel photometric data of these stars. We detected a small amplitude (but significant) Blazhko effect for both stars by using the resulting light curves and O-C diagrams. This finding strengthens the apparent connection between the Blazhko effect and the excitation of additional modes. In addition, it yields a potential tool for detecting Blazhko stars through the additional frequency patterns, even if we have only short but accurate time series observations. V350 Lyr shows the smallest amplitude multiperiodic Blazhko effect ever detected.

  16. Effect of fructo-oligosaccharide and isomalto-oligosaccharide addition on baking quality of frozen dough.

    PubMed

    Park, Eun Young; Jang, Sung-Bum; Lim, Seung-Taik

    2016-12-15

    The baking quality of frozen doughs containing different levels of fructo-oligosaccharides (FO) or isomalto-oligosaccharides (IMO) (3-9%, w/w flour), and stored for 0-8weeks at -18°C, was examined. The addition of FO or IMO increased the proof volume of the dough and the loaf volume of bread prepared from frozen dough. A 6% addition of FO or IMO was optimum, giving the highest proof volume and bread loaf volume, but a higher concentration than 6% induced low baking quality including lower proof volume and bread loaf volume. The bread crumb was moister and softer after the addition of FO or IMO before, and even after, frozen storage. Darker crumb colour was observed in the bread after the addition of FO or IMO. The oligosaccharides added to the frozen dough were effective in improving the quality of bread made from frozen dough, except for resulting in a darker bread crumb. PMID:27451167

  17. Effects of TFA addition on the growth of sintered YBa2Cu3Oy superconductors

    NASA Astrophysics Data System (ADS)

    Kita, Ryusuke; Kuroda, Keita; Kato, Teppei; Miura, O.; Yamada, K.; Kaneko, K.

    The effects of trifluoroacetic acid (TFA) addition on the growth of a superconducting phase in sintered YBCO samples were investigated. YBCO samples with TFA addition were prepared by adding TFA (99.0%) to YBCO powder and then pressed into pellets and heated 1173 K - 1213 K for 12 - 20 hr in air. After the heat treatment, the TFA-added sample showed large grain sizes and highly c-axis oriented structures compared to pure YBCO samples, which indicates the enhancement of the grain growth of YBCO sintered samples by the TFA addition. The Jc (0) value and Jc/Jc (0T) properties of the sintered samples was improved by the TFA addition.

  18. Effect of Fuel Additives on Spray Performance of Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2015-11-01

    Role of alternative fuels on reducing the combustion pollutants is gaining momentum in both land and air transport. Recent studies have shown that addition of nanoscale metal particles as fuel additives to liquid fuels have a positive effect not only on their combustion performance but also in reducing the pollutant formation. However, most of those studies are still in the early stages of investigation with the addition of nanoparticles at low weight percentages. Such an addition can affect the hydrodynamic and thermo-physical properties of the fuel. In this study, the near nozzle spray performance of gas-to-liquid jet fuel with and without the addition of alumina nanoparticles are investigated at macro- and microscopic levels using optical diagnostic techniques. At macroscopic level, the addition of nanoparticles is seen to enhance the sheet breakup process when compared to that of the base fuel. Furthermore, the microscopic spray characteristics such as droplet size and velocity are also found to be affected. Although the addition of nanoscale metal particles at low weight percentages does not affect the bulk fluid properties, the atomization process is found to be affected in the near nozzle region. Funded by Qatar National Research Fund.

  19. Effect on intake valve deposits of ethanol and additives common to the available ethanol supply

    SciTech Connect

    Shibolm, C.M.; Schoonveld, G.A.

    1990-01-01

    With the widespread introduction of the third generation additives to modern gasolines, the author's company chose to further define the effects of gasoline/ethanol blends (gasohol) on intake system deposits (ISD). The third generation additives referred to here are those that provide protection against ISD. This paper presents detailed results of the investigation in this area. During evaluation of various ISD additives, it was found that additive levels capable of controlling ISD with normal gasolines were unable to do so with fuels containing neat ethanol. Most fuel grade ethanol available in the marketplace is pretreated with additives intended to control accumulation of port fuel injector (PFI) deposits. These currently accepted PFI additives proved to be even more of a problem to intake valves than neat ethanol in gasoline. Some, however, contributed more to valve deposits than others. Data for this investigation was generated via the Modified IVD Test in BMW vehicles at an independent laboratory. Results identify that proper gasoline and ethanol additive combinations and treatment levels can provide satisfactory ISD protection in gasoline engines.

  20. Quantification of Treatment Effect Modification on Both an Additive and Multiplicative Scale

    PubMed Central

    Girerd, Nicolas; Rabilloud, Muriel; Pibarot, Philippe; Mathieu, Patrick; Roy, Pascal

    2016-01-01

    Background In both observational and randomized studies, associations with overall survival are by and large assessed on a multiplicative scale using the Cox model. However, clinicians and clinical researchers have an ardent interest in assessing absolute benefit associated with treatments. In older patients, some studies have reported lower relative treatment effect, which might translate into similar or even greater absolute treatment effect given their high baseline hazard for clinical events. Methods The effect of treatment and the effect modification of treatment were respectively assessed using a multiplicative and an additive hazard model in an analysis adjusted for propensity score in the context of coronary surgery. Results The multiplicative model yielded a lower relative hazard reduction with bilateral internal thoracic artery grafting in older patients (Hazard ratio for interaction/year = 1.03, 95%CI: 1.00 to 1.06, p = 0.05) whereas the additive model reported a similar absolute hazard reduction with increasing age (Delta for interaction/year = 0.10, 95%CI: -0.27 to 0.46, p = 0.61). The number needed to treat derived from the propensity score-adjusted multiplicative model was remarkably similar at the end of the follow-up in patients aged < = 60 and in patients >70. Conclusions The present example demonstrates that a lower treatment effect in older patients on a relative scale can conversely translate into a similar treatment effect on an additive scale due to large baseline hazard differences. Importantly, absolute risk reduction, either crude or adjusted, can be calculated from multiplicative survival models. We advocate for a wider use of the absolute scale, especially using additive hazard models, to assess treatment effect and treatment effect modification. PMID:27045168