Actinide and Xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D.L.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and Xenon reactivity effects in ATW high flux systems

Energy Technology Data Exchange (ETDEWEB)

Woosley, M. [Univ. of Virginia, Charlottesville, VA (United States); Olson, K.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)] [and others

1995-10-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

Reactivity effects due to beryllium poisoning of BR2

International Nuclear Information System (INIS)

Kalcheva, S.; Ponsard, B.; Koonen, E.

2004-01-01

This paper illustrates the impact of the poisoning of the beryllium reflector on reactivity variations of the Belgian MTR BR2 in SCK.CEN. Detailed calculations by MCNP-4C of reactivity effects caused by strong neutron absorbers 3 He and 6 Li during reactor operation history are presented. The importance of beryllium poisoning for the accuracy of reactivity predictions is discussed. (authors)

Measurement of reactivity effect caused by nonuniform fuel distribution

International Nuclear Information System (INIS)

Yamane, Yoshihiro; Hirano, Yasushi; Yasui, Hazime; Nishina, Kojiro; Shiroya, Seiji

1991-01-01

A reactivity effect due to a spatial variation of nuclear fuel concentration is an important problem in a reprocessing plant. To estimate this reactivity effect theoretically, the ''Goertzel's necessary condition, and th Fuel Importance'' theory have been proposed. In order to verify these theories, we have performed systematic measurements of reactivity effect due to the nonuniformity in the fuel distribution within the Kyoto University Critical Assembly. Neutron flux distribution and Fuel Importance distribution were also determined. A nonuniform assembly whose fuel concentration in the center region was 40% higher than the uniform one was found to have an excess reactivity of 0.3%Δk/k, with the same total uranium mass for which the uniform assembly was just critical. Moreover, its spatial distribution of thermal neutron flux and of Fuel Importance were more flat than those of the uniform assembly, as expected by the Goertzel's condition and the Fuel Importance theory. (Author)

Exaggerated secretion of glucagon-like peptide-1 (GLP-1) could cause reactive hypoglycaemia

DEFF Research Database (Denmark)

Toft-Nielsen, M; Madsbad, Sten; Holst, Jens Juul

1998-01-01

The plasma concentrations of the insulinotropic incretin hormone, glucagon-like peptide-1 (GLP-1) are abnormally high after oral glucose in partially gastrectomised subjects with reactive hypoglycaemia, suggesting a causal relationship. Because of the glucose-dependency of its effects, it is impo......The plasma concentrations of the insulinotropic incretin hormone, glucagon-like peptide-1 (GLP-1) are abnormally high after oral glucose in partially gastrectomised subjects with reactive hypoglycaemia, suggesting a causal relationship. Because of the glucose-dependency of its effects...

Influence of life stress on immunological reactivity to mild psychological stress

NARCIS (Netherlands)

Brosschot, J. F.; Benschop, R. J.; Godaert, G. L.; Olff, M.; de Smet, M.; Heijnen, C. J.; Ballieux, R. E.

1994-01-01

This study investigated the effects of self-reported life stress and locus of control on reactivity of several immune parameters to a mild and short-lasting interpersonal stressor. Subjects were 86 male teachers aged 24 to 55 years. Immune reactivity was defined as changes in numbers of monocytes.

The experimental study of digital reactivity meter with space effect elimination

International Nuclear Information System (INIS)

Xie, Y.Q.; Jian, Z.B.; Zhang, Y.S.

1988-01-01

The paper summarizes a digital reactivity measurement theory with space effect elimination. On the basis of the theory, we have prepared an on-line digital reactivity meter with space effect elimination. This system is composed of neutron detector and magnifying, data acquisition channel, monoplate microprocessor and data output channel. Measured results of reactivity using the method described in this paper are in agreement with measured results of reactivity using the pulsed neutron method and 'ρ-shape' method within experimental error. (author)

Blunted stress reactivity in chronic cannabis users.

Science.gov (United States)

Cuttler, Carrie; Spradlin, Alexander; Nusbaum, Amy T; Whitney, Paul; Hinson, John M; McLaughlin, Ryan J

2017-08-01

One of the most commonly cited reasons for chronic cannabis use is to cope with stress. Consistent with this, cannabis users have shown reduced emotional arousal and dampened stress reactivity in response to negative imagery. To our knowledge, the present study represents the first to examine the effects of an acute stress manipulation on subjective stress and salivary cortisol in chronic cannabis users compared to non-users. Forty cannabis users and 42 non-users were randomly assigned to complete either the stress or no stress conditions of the Maastricht Acute Stress Test (MAST). The stress condition of the MAST manipulates both physiological (placing hand in ice bath) and psychosocial stress (performing math under conditions of social evaluation). Participants gave baseline subjective stress ratings before, during, and after the stress manipulation. Cortisol was measured from saliva samples obtained before and after the stress manipulation. Further, cannabis cravings and symptoms of withdrawal were measured. Subjective stress ratings and cortisol levels were significantly higher in non-users in the stress condition relative to non-users in the no stress condition. In contrast, cannabis users demonstrated blunted stress reactivity; specifically, they showed no increase in cortisol and a significantly smaller increase in subjective stress ratings. The stress manipulation had no impact on cannabis users' self-reported cravings or withdrawal symptoms. Chronic cannabis use is associated with blunted stress reactivity. Future research is needed to determine whether this helps to confer resiliency or vulnerability to stress-related psychopathology as well as the mechanisms underlying this effect.

Acute effects of LSD on amygdala activity during processing of fearful stimuli in healthy subjects.

Science.gov (United States)

Mueller, F; Lenz, C; Dolder, P C; Harder, S; Schmid, Y; Lang, U E; Liechti, M E; Borgwardt, S

2017-04-04

Lysergic acid diethylamide (LSD) induces profound changes in various mental domains, including perception, self-awareness and emotions. We used functional magnetic resonance imaging (fMRI) to investigate the acute effects of LSD on the neural substrate of emotional processing in humans. Using a double-blind, randomised, cross-over study design, placebo or 100 μg LSD were orally administered to 20 healthy subjects before the fMRI scan, taking into account the subjective and pharmacological peak effects of LSD. The plasma levels of LSD were determined immediately before and after the scan. The study (including the a priori-defined study end point) was registered at ClinicalTrials.gov before study start (NCT02308969). The administration of LSD reduced reactivity of the left amygdala and the right medial prefrontal cortex relative to placebo during the presentation of fearful faces (PLSD-induced amygdala response to fearful stimuli and the LSD-induced subjective drug effects (PLSD modulates the engagement of brain regions that mediate emotional processing.

Effect of intravenous N-acetylcysteine infusion on haemostatic parameters in healthy subjects

DEFF Research Database (Denmark)

Knudsen, TT; Thorsen, S; Jensen, SA

2005-01-01

BACKGROUND AND AIMS: N-acetylcysteine is used to treat paracetamol overdose but depresses the activity of plasma coagulation factors II, VII, and X, which are often used to assess liver injury. The aim of this study was to investigate the effect of N-acetylcysteine on haemostasis in normal...... volunteers. METHODS: Haemostatic parameters in 10 healthy subjects were analysed before and following intravenous infusion of therapeutic doses of N-acetylcysteine, as well as in vitro. RESULTS: N-acetylcysteine induced significant decreases in plasma levels of vitamin K dependent haemostatic proteins...... activity, and free protein S reactivity, respectively. These data suggest that N-acetylcysteine induces protein modifications affecting activity. Five subjects developed an adverse reaction to infusion of N-acetylcysteine and these were associated with a rapid increase in levels of factor VIII and its...

Present art of reactivity determination

International Nuclear Information System (INIS)

Kaneko, Yoshihiko; Nakano, Masafumi; Matsuura, Shojiro

1977-01-01

Experimental techniques for reactivity determination of a reactor have been one of the long standing subjects in reactor physics. Recently, such a requirement was proposed by the reactor designers and operators that the values of reactivity should be measured more accurately. This is because importance is emphasized for the role of reactivity to the performance of reactor safety, economics and operability. Motivated by the requirement, some remarkable progresses are being made for the improvement of the experimental techniques. Then, the present review summarizes the research activities on this subject, identifies several reactor physics problems to be overcome, and makes mention of the future targets. (auth.)

A revision of sensitivity analysis for small reactivity effects in ZPRs

International Nuclear Information System (INIS)

Ros, Paul; Blaise, Patrick; Gruel, Adrien; Leconte, Pierre

2017-01-01

Sensitivity analysis appears to be an important element for nuclear data improvement experiments. Indeed, it brings significant information on the contribution of the isotopes involved in the measurements performed in Zero Power Reactors (ZPRs), particularly oscillation measurements like in MINERVE, and its successor ZEPHYR (Zero power Experimental PHYsics Reactor), currently being designed at CEA. Oscillation measurements consist in oscillating a small sample made of separated isotopes (or irradiated fuels) in the core center. Then, two perturbations occur: a local one corresponding to the flux modification around the sample, and a global one which corresponds to the induced variation of reactivity. This variation of reactivity is either uncontrolled (open loop) or automatically compensated by an external pilot rod (closed loop) to keep the configuration in its critical state. Representativity studies are used in order to evaluate the pertinence of an experiment configuration versus a targeted application. For oscillation experiments, sensitivity of the reactivity effects to nuclear data is needed to obtain such coefficients. The Equivalent Generalized Perturbation Theory (EGPT) method, based on an approximation of the Generalized Perturbation. Theory, is currently applied in the ERANOS code for control rod insertions and other important variations of reactivity. However, such reactivity insertions induce consequent reactivity changes and variations of the flux, whereas oscillations induce maximal reactivity effects of 10 pcm (10 10 -5 Δk/k ) and consequently very local variations of the flux surrounding the sample. Therefore, such numerical methods are not necessarily adapted to the calculation of small reactivity effect sensitivities to nuclear data. The influence of peripheral isotopes (through their cross-sections) to central measurements is evaluated thanks to the deterministic EGPT method and the Monte-Carlo technique of correlated samples. Large

Event-Based Modularization of Reactive Systems

NARCIS (Netherlands)

Malakuti Khah Olun Abadi, Somayeh; Aksit, Mehmet

2014-01-01

There is a large number of complex software systems that have reactive behavior. As for any other software system, reactive systems are subject to evolution demands. This paper defines a set requirements that must be fulfilled so that reuse of reactive software systems can be increased. Detailed

Gut microbiome response to short-term dietary interventions in reactive hypoglycemia subjects.

Science.gov (United States)

Quercia, Sara; Turroni, Silvia; Fiori, Jessica; Soverini, Matteo; Rampelli, Simone; Biagi, Elena; Castagnetti, Andrea; Consolandi, Clarissa; Severgnini, Marco; Pianesi, Mario; Fallucca, Francesco; Pozzilli, Paolo; Brigidi, Patrizia; Candela, Marco

2017-11-01

Reactive hypoglycemia is a metabolic disorder that provokes severe hypoglycemic episodes after meals. Over recent years, the gut microbiota has been recognized as potential target for the control of metabolic diseases, and the possibility to correct gut microbiota dysbioses through diet, favouring the recovery of metabolic homeostasis, has been considered. We investigate the impact of 2 short-term (3-day) nutritional interventions, based on the macrobiotic Ma-Pi 2 diet and a control Mediterranean diet, on the structure and functionality of the gut microbiota in 12 patients affected by reactive hypoglycemia. The gut microbiota composition was characterized by next-generation sequencing of the V3 to V4 region of the 16S rRNA gene, and the ecosystem functionality was addressed by measuring the faecal concentration of short-chain fatty acids (SCFAs). In order to measure the short-term physiological gut microbiota fluctuation, the microbiomes of 7 healthy people were characterized before and after 3 days of constant diet. While no convergence of the gut microbiota compositional profiles was observed, a significant increase in SCFA faecal levels was induced only in the Ma-Pi 2 diet group, suggesting the potential of this diet to support a short-term functional convergence of the gut microbiota, regardless of the individual compositional layout. The Ma-Pi 2 diet, with its high fibre load, was effective in increasing the production of SCFAs by the gut microbiota. Because these metabolites are known for their ability to counterbalance the metabolic deregulation in persons with glucose impairment disorders, their increased bioavailability could be of some relevance in reactive hypoglycemia. Copyright © 2017 John Wiley & Sons, Ltd.

A carnosine intervention study in overweight human volunteers: bioavailability and reactive carbonyl species sequestering effect

Science.gov (United States)

Regazzoni, Luca; de Courten, Barbora; Garzon, Davide; Altomare, Alessandra; Marinello, Cristina; Jakubova, Michaela; Vallova, Silvia; Krumpolec, Patrik; Carini, Marina; Ukropec, Jozef; Ukropcova, Barbara; Aldini, Giancarlo

2016-06-01

Carnosine is a natural dipeptide able to react with reactive carbonyl species, which have been recently associated with the onset and progression of several human diseases. Herein, we report an intervention study in overweight individuals. Carnosine (2 g/day) was orally administered for twelve weeks in order to evaluate its bioavailability and metabolic fate. Two carnosine adducts were detected in the urine samples of all subjects. Such adducts are generated from a reaction with acrolein, which is one of the most toxic and reactive compounds among reactive carbonyl species. However, neither carnosine nor adducts have been detected in plasma. Urinary excretion of adducts and carnosine showed a positive correlation although a high variability of individual response to carnosine supplementation was observed. Interestingly, treated subjects showed a significant decrease in the percentage of excreted adducts in reduced form, accompanied by a significant increase of the urinary excretion of both carnosine and carnosine-acrolein adducts. Altogether, data suggest that acrolein is entrapped in vivo by carnosine although the response to its supplementation is possibly influenced by individual diversities in terms of carnosine dietary intake, metabolism and basal production of reactive carbonyl species.

Effect of reactive atmosphere on pulsed laser deposition of hydroxyapatite thin films

Czech Academy of Sciences Publication Activity Database

Mroz, W.; Jedynski, M.; Hoffman, J.; Jelínek, Miroslav; Major, B.; Prokopiuk, A.; Szymanski, Z.

2007-01-01

Roč. 59, - (2007), s. 720-723 ISSN 1742-6588 Grant - others:PBZ-KBN(PL) 100/TO8/2003 and 0028/TOO/2005/29 Institutional research plan: CEZ:AV0Z10100522 Keywords : PLD * hydroxyapatite * reactive atmosphere * thin layers Subject RIV: BM - Solid Matter Physics ; Magnetism

Effectiveness of Chinese Martial Arts and Philosophy to Reduce Reactive and Proactive Aggression in Schoolchildren.

Science.gov (United States)

Fung, Annis Lai Chu; Lee, Toney Ka Hung

2018-04-10

This study examined the effectiveness of Chinese martial arts in reducing reactive and proactive aggressive behavior among schoolchildren with a cluster-randomized trial. A screening questionnaire was completed by 3511 schoolchildren of Grades 2 to 5 from 13 sites in Hong Kong. We shortlisted 298 children who scored z ≥ 1 on the total score of the Reactive-Proactive Aggression Questionnaire in their respective sites to participate in the experiment. They were divided into 31 clusters that were blinded and randomly assigned to one of the 4 conditions: skills only, philosophy only, skills and philosophy, and physical fitness (placebo). Subjects were assessed at baseline, posttraining, and 6 months after training using aggression scales. Results from the linear mixed model indicated that the time × training interaction effects were significant for aggressive behavior (reactive and proactive), delinquent behavior, anxiety/depression, and attention problems. Although all measures declined in all conditions over time, only the skills-and-philosophy condition showed a significant reduction at posttraining and/or 6-month follow-up compared with the placebo. The results provided a theoretical proof for the relationship between aggression and sport involvement combined with children's moral reasoning. This study gives practical implications to intervention that solely playing sports or teaching moral lessons is not effective enough for high-risk schoolchildren with aggressive behavior. However, combined traditional Chinese martial arts skills and moral philosophy training could be considered in the school curriculum to reduce school violence and facilitate creation of harmonious schools.

Reduction in reactive oxygen species production by mitochondria from elderly subjects with normal and impaired glucose tolerance.

Science.gov (United States)

Ghosh, Sangeeta; Lertwattanarak, Raweewan; Lefort, Natalie; Molina-Carrion, Marjorie; Joya-Galeana, Joaquin; Bowen, Benjamin P; Garduno-Garcia, Jose de Jesus; Abdul-Ghani, Muhammad; Richardson, Arlan; DeFronzo, Ralph A; Mandarino, Lawrence; Van Remmen, Holly; Musi, Nicolas

2011-08-01

Aging increases the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes. It has been proposed that increased reactive oxygen species (ROS) generation by dysfunctional mitochondria could play a role in the pathogenesis of these metabolic abnormalities. We examined whether aging per se (in subjects with normal glucose tolerance [NGT]) impairs mitochondrial function and how this relates to ROS generation, whether older subjects with IGT have a further worsening of mitochondrial function (lower ATP production and elevated ROS generation), and whether exercise reverses age-related changes in mitochondrial function. Mitochondrial ATP and ROS production were measured in muscle from younger individuals with NGT, older individuals with NGT, and older individuals with IGT. Measurements were performed before and after 16 weeks of aerobic exercise. ATP synthesis was lower in older subjects with NGT and older subjects with IGT versus younger subjects. Notably, mitochondria from older subjects (with NGT and IGT) displayed reduced ROS production versus the younger group. ATP and ROS production were similar between older groups. Exercise increased ATP synthesis in the three groups. Mitochondrial ROS production also increased after training. Proteomic analysis revealed downregulation of several electron transport chain proteins with aging, and this was reversed by exercise. Old mitochondria from subjects with NGT and IGT display mitochondrial dysfunction as manifested by reduced ATP production but not with respect to increased ROS production. When adjusted to age, the development of IGT in elderly individuals does not involve changes in mitochondrial ATP and ROS production. Lastly, exercise reverses the mitochondrial phenotype (proteome and function) of old mitochondria.

Analytical estimation of control rod shadowing effect for excess reactivity measurement of HTTR

International Nuclear Information System (INIS)

Nakano, Masaaki; Fujimoto, Nozomu; Yamashita, Kiyonobu

1999-01-01

The fuel addition method is generally used for the excess reactivity measurement of the initial core. The control rod shadowing effect for the excess reactivity measurement has been estimated analytically for High Temperature Engineering Test Reactor (HTTR). 3-dimensional whole core analyses were carried out. The movements of control rods in measurements were simulated in the calculation. It was made clear that the value of excess reactivity strongly depend on combinations of measuring control rods and compensating control rods. The differences in excess reactivity between combinations come from the control rod shadowing effect. The shadowing effect is reduced by the use of plural number of measuring and compensating control rods to prevent deep insertion of them into the core. The measured excess reactivity in the experiments is, however, smaller than the estimated value with shadowing effect. (author)

Effect of substituents on the reactivity of ninhydrin with urea

NARCIS (Netherlands)

Jong, Jacobus A.W.; Moret, Marc Etienne; Verhaar, Marianne C.; Hennink, Wim E.; Gerritsen, Karin G.F.; Van Nostrum, Cornelus F.

2018-01-01

Ninhydrin, i. e. the stable hydrate of the reactive species indanetrione, is a well-known compound used for the quantification of ammonia and amino acids. However, substituent effects on the reactivity of ninhydrin with nucleophiles are not described. In this work, the kinetics of the reaction of

Serum C-reactive protein and thioredoxin levels in subjects with mildly reduced glomerular filtration rate

Directory of Open Access Journals (Sweden)

Ishimura Eiji

2010-04-01

Full Text Available Abstract Background Chronic kidney disease (CKD is a newly recognized high-risk condition for cardiovascular disease (CVD, and previous studies reported the changes in inflammation and oxidative stress in advanced stages of CKD. We compared the levels of serum biomarkers for inflammation and oxidative stress between subjects with normal and mildly reduced glomerular filtration rate (GFR. Methods The subjects were 182 participants of a health check-up program including those with normal (≥ 90 mL/min/1.73 m2, N = 79 and mildly reduced eGFR (60-89 mL/min/1.73 m2, N = 103 which was calculated based on serum creatinine, age and sex. We excluded those with reduced eGFR 2. No one had proteinuria. We measured serum levels of C-reactive protein (CRP and thioredoxin (TRX as the markers of inflammation and oxidative stress, respectively. Results As compared with subjects with normal eGFR, those with mildly reduced eGFR had increased levels of both CRP and TRX. Also, eGFR was inversely correlated with these biomarkers. The associations of eGFR with these biomarkers remained significant after adjustment for age and sex. When adjustment was done for eight possible confounders, CRP showed significant association with systolic blood pressure, high density lipoprotein cholesterol (HDL-C and non-HDL-C, whereas TRX was associated with sex significantly, and with eGFR and systolic blood pressure at borderline significance. Conclusions We showed the increased levels of CRP and TRX in subjects with mildly reduced eGFR. The eGFR-CRP link and the eGFR-TRX link appeared to be mediated, at least partly, by the alterations in blood pressure and plasma lipids in these subjects.

Effect of polyunsaturated fatty acids on the reactive oxygen and nitrogen species production by raw 264.7 macrophages

Czech Academy of Sciences Publication Activity Database

Ambrožová, Gabriela; Pekarová, Michaela; Lojek, Antonín

2010-01-01

Roč. 49, č. 3 (2010), s. 133-139 ISSN 1436-6207 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : polyunsaturated fatty acids * reactive oxygen species * reactive nitrogen species Subject RIV: BO - Biophysics Impact factor: 3.343, year: 2010

Effect of Aerobic Exercise on C-reatine reactive protein and Index of ...

African Journals Online (AJOL)

Lamina

Subjects in the interval group involved in interval training (60-79% maximum heart ... of exercise training on C-reactive protein, erectile function index, SBP, DBP ... patients with cardiac disease have shown a high .... low intensity of between 35-59% of their HR max .... Aging and Body Composition Study (Health ABC) (40),.

Multimodal assessment of emotional reactivity in borderline personality pathology: the moderating role of posttraumatic stress disorder symptoms.

Science.gov (United States)

Dixon-Gordon, Katherine L; Gratz, Kim L; Tull, Matthew T

2013-08-01

Emotional reactivity has been theorized to play a central role in borderline personality (BP) pathology. Although growing research provides evidence for subjective emotional reactivity in BP pathology, research on physiological or biological reactivity among people with BP pathology is less conclusive. With regard to biological reactivity in particular, research on cortisol reactivity (a neurobiological marker of emotional reactivity) in response to stressors among individuals with BP pathology has produced contradictory results and highlighted the potential moderating role of PTSD-related pathology. Thus, this study sought to examine the moderating role of PTSD symptoms in the relation between BP pathology and both subjective (self-report) and biological (cortisol) emotional reactivity to a laboratory stressor. Participants were 171 patients in a residential substance use disorder treatment center. Consistent with hypotheses, results revealed a significant main effect of BP pathology on subjective emotional reactivity to the laboratory stressor. Furthermore, results revealed a significant interaction between BP pathology and PTSD symptoms in the prediction of cortisol reactivity, such that BP pathology was associated with heightened cortisol reactivity only among participants with low levels of PTSD symptoms. Similar findings were obtained when examining the interaction between BP pathology and the reexperiencing and avoidance/numbing symptoms of PTSD specifically. Results highlight the moderating role of PTSD symptoms in the BP-reactivity relation. Copyright © 2013 Elsevier Inc. All rights reserved.

Significance of isolated reactive treponemal chemiluminescence immunoassay results.

Science.gov (United States)

Hunter, Michael G; Robertson, Peter W; Post, Jeffrey J

2013-05-01

Isolated reactive serum treponemal chemiluminescence immunoassay (CIA) specimens cause clinical uncertainty. Sera were screened by CIA, and reactive samples underwent reflex testing with rapid plasma reagin (RPR), Treponema pallidum particle agglutination (TPPA), and fluorescent treponemal antibody absorption (FTA Abs) assays. Samples reactive only on the CIA were deemed "isolated" reactive CIA samples. We undertook detailed review of a subset of subjects with isolated reactive CIA specimens. Of 28 261 specimens, 1171 (4.1%) were reactive on CIA, of which 133 (11.3%) had isolated CIA reactivity. Most subjects (66 of 82 [80.5%]) with isolated reactive CIA specimens were from high-prevalence populations. We found evidence of CIA, TPPA, and FTA Abs seroreversion. The median chemiluminescent signal-to-cutoff ratio was similar for isolated reactive CIA sera and sera that were reactive on either FTA Abs or TPPA assays (2.19 vs 2.32; P = .15) but lower than for sera reactive on both FTA Abs and TPPA assays (12.37; P < .001) or for sera reactive on RPR assays (25.53; P < .001). A total of 11 of 20 patients (55%) with an isolated reactive CIA specimen who underwent medical record review had previous or subsequent evidence of syphilis infection. Isolated reactive CIA specimens may represent true T. pallidum infection and may be found after seroreversion of traditional treponemal assays.

Void effects on BWR Doppler and void reactivity feedback

International Nuclear Information System (INIS)

Hsiang-Shou Cheng; Diamond, D.J.

1978-01-01

The significance of steam voids and control rods on the Doppler feedback in a gadolinia shimmed BWR is demonstrated. The importance of bypass voids when determining void feedback is also shown. Calculations were done using a point model, i.e., feedback was expressed in terms of reactivity coefficients which were determined for individual four-bundle configurations and then appropriately combined to yield reactor results. For overpower transients the inclusion of the void effect of control rods is to reduce Doppler feedback. For overpressurization transients the inclusion of the effect of bypass void wil increase the reactivity due to void collapse. (author)

The effect of interfacial modification on the properties of reactively processed polypropylene/clay nanocomposites

Czech Academy of Sciences Publication Activity Database

Khunová, V.; Kelnar, Ivan; Liauw, C. M.; Lukáč, P.

2011-01-01

Roč. 18, č. 4 (2011), s. 357-370 ISSN 0927-6440 Institutional research plan: CEZ:AV0Z40500505 Keywords : nanocomposite * reactive processing * polyolefins Subject RIV: JI - Composite Materials Impact factor: 0.438, year: 2011

Reactivity effects of fission product decay in PWRs

International Nuclear Information System (INIS)

Aragones, J.M.; Ahnert, C.

1988-01-01

The purpose of the work reported in this paper is to analyze the effects of fission product chains with radioactive decay on the reactivity in pressurized water reactor (PWR) cores, calculating their accumulation and absorption rates along fuel burnup at continuous operation and after shutdown periods extending from 1 day to a few months. The authors PWR version of the WIMS-D4 code is first used to obtain the individual number densities, absorption rates, and averaged cross sections for every nuclide of the fission product chains with significant decay rates, as a function of fuel burnup at continuous irradiation. Next, by an auxiliary ad hoc code, these data, have been processed together with the required one for fissile nuclides and boron, also taken from WIMS at each burnup step, to calculate the average or effective values relevant for the analysis and the decay and change in overall absorption after several shutdown times. (1) The reactivity effect of fission product decay changes significantly with the shutdown time. The maximum absorption increase by decay is reached in ∼ 10 days' shutdown. (2) The dependence with fuel type, enrichment, and burnup is slight, but the change with previous power density is nearly linear, which might be significant after coast-down in previous cycles. (3) For long shutdown periods, the overall reactivity effect of decay in the three fission product chains considered is much less than if only the samarium peak due to 149 Nd is considered

Effective NH2-grafting on attapulgite surfaces for adsorption of reactive dyes

International Nuclear Information System (INIS)

Xue, Ailian; Zhou, Shouyong; Zhao, Yijiang; Lu, Xiaoping; Han, Pingfang

2011-01-01

Highlights: → We prepared a new amine functionalized adsorbent derived from clay-based material. → Attapulgite surface was modified with 3-aminopropyltriethoxysilane. → Some modification parameters affecting the adsorption potential were investigated. → Enhance the attapulgite adsorptive capacity for reactive dyes from aqueous solutions. - Abstract: The amine moiety has an important function in many applications, including, adsorption, catalysis, electrochemistry, chromatography, and nanocomposite materials. We developed an effective adsorbent for aqueous reactive dye removal by modifying attapulgite with an amino-terminated organosilicon (3-aminopropyltriethoxysilane, APTES). Surface properties of the APTES-modified attapulgite were characterized by the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption. We evaluated the impact of solvent, APTES concentration, water volume, reaction time, and temperature on the surface modification. NH 2 -attapulgite was used to remove reactive dyes in aqueous solution and showed very high adsorption rates of 99.32%, 99.67%, and 96.42% for Reactive Red 3BS, Reactive Blue KE-R and Reactive Black GR, respectively. These powerful dye removal effects were attributed to strong electrostatic interactions between reactive dyes and the grafted NH 2 groups.

Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

International Nuclear Information System (INIS)

Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O.; Martins, C.N.; Silva, A.M.V.; Plentz, R.D.M.; Irigoyen, M.C.; Signori, L.U.

2014-01-01

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia

Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

Energy Technology Data Exchange (ETDEWEB)

Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Martins, C.N. [Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Silva, A.M.V. [Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Plentz, R.D.M. [Universidade Federal de Ciências da Saúde de Porto Alegre, Programa de Pós-Graduação em Ciências da Reabilitação, Programa de Pós-Graduação em Ciências da Saúde, Porto Alegre, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Programa de Pós-Graduação em Ciências da Reabilitação, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Irigoyen, M.C. [Faculdade de Medicina, Universidade de São Paulo, Instituto do Coração, Unidade de Hipertensão, São Paulo, SP, Brasil, Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Signori, L.U. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

2014-04-04

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

Reactivity effect of spent fuel depending on burn-up history

International Nuclear Information System (INIS)

Hayashi, Takafumi; Suyama, Kenya; Nomura, Yasushi

2001-06-01

It is well known that a composition of spent fuel depends on various parameter changes throughout a burn-up period. In this study we aimed at the boron concentration and its change, the coolant temperature and its spatial distribution, the specific power, the operation mode, and the duration of inspection, because the effects due to these parameters have not been analyzed in detail. The composition changes of spent fuel were calculated by using the burn-up code SWAT, when the parameters mentioned above varied in the range of actual variations. Moreover, to estimate the reactivity effect caused by the composition changes, the criticality calculations for an infinite array of spent fuel were carried out with computer codes SRAC95 or MVP. In this report the reactivity effects were arranged from the viewpoint of what parameters gave more positive reactivity effect. The results obtained through this study are useful to choose the burn-up calculation model when we take account of the burn-up credit in the spent fuel management. (author)

Cerebrovascular mental stress reactivity is impaired in hypertension

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Naqvi Tasneem Z

2009-07-01

Full Text Available Abstract Background Brachial artery reactivity in response to shear stress is altered in subjects with hypertension. Since endothelial dysfunction is generalized, we hypothesized that carotid artery (CA reactivity would also be altered in hypertension. Purpose To compare (CA endothelium-dependent vasodilation in response to mental stress in normal and hypertensive subjects. Methods We evaluated CA reactivity to mental stress in 10 young healthy human volunteers (aged 23 ± 4 years, 20 older healthy volunteers (aged 49 ± 11 years and in 28 patients with essential hypertension (aged 51 ± 13 years. In 10 healthy volunteers and 12 hypertensive subjects, middle cerebral artery (MCA PW transcranial Doppler was performed before and 3 minutes after mental stress. Results Mental stress by Stroop color word conflict, math or anger recall tests caused CA vasodilation in young healthy subjects (0.61 ± 0.06 to 0.65 ± 0.07 cm, p Conclusion Mental stress produces CA vasodilation and is accompanied by an increase in CA and MCA blood flow in healthy subjects. This mental stress induced CA vasodilation and flow reserve is attenuated in subjects with hypertension and may reflect cerebral vascular endothelial dysfunction. Assessment of mental stress induced CA reactivity by ultrasound is a novel method for assessing the impact of hypertension on cerebrovascular endothelial function and blood flow reserve.

Elevated concentrations of C-reactive protein in subjects with type 2 diabetes mellitus are moderately influenced by glycemic control.

Science.gov (United States)

Rodríguez-Morán, M; Guerrero-Romero, F

2003-03-01

The aim of this study was to establish whether glycemic control results in decrease of C-reactive protein (CRP) in Type 2 diabetic subjects. Newly diagnosed Type 2 diabetic subjects were recruited and followed-up by 6-month intensive medical management. All the participants were carefully interviewed, clinically examined, and laboratory tested to exclude conditions likely to provoke an inflammatory response, which was an exclusion criterium. CRP was measured by automated microparticle enzyme immunoassay (IMx, Abbott Laboratories, USA). Two-hundred and forty-eight patients were included in the analysis of data. At baseline, average CRP levels were of 9.6 +/- 6.2 mg/l. Only 14 (5.7%) patients showed a fasting glucose equal or lower than 6.1 mmo/l (5.6 +/- 0.4 mmo/l); of them, 6 (42.8%) had elevated CRP levels (8.8 +/- 6.7 mg/l). The fasting glucose in the 234 (94.3%) non-controlled subjects was 13.1 +/- 4.8 mmol/l; of them 179 (76.5%) subjects showed elevated CRP levels (10.9 +/- 6.5 mg/I). At the end of the 6-month follow-up, the average fasting glucose and HbA1c in the overall group decreased from 12.5 +/- 5.0 to 9.0 +/- 1.6 mmol/l, p diabetic subjects.

Relationship between general intelligence, emotional intelligence, stress levels and stress reactivity.

Science.gov (United States)

Singh, Yogesh; Sharma, Ratna

2012-07-01

Stressful life events and daily life stresses have both deleterious and cumulative effects on human body. In several studies, stress has been shown to affect various parameter of higher mental function like attention, concentration, learning and memory. Present study was designed to explore the relationship among GI level, EI level, psychological stress levels and acute stress reactivity in young normal healthy subjects. The study was conducted on thirty four healthy male student volunteers to study a) acute stress reactivity in subjects with varying levels of General Intelligence (GI) and Emotional Intelligence (EI) and b) correlation between GI, EI, acute stress and perceived stress. Baseline GI and EI and acute stress and perceived stress scores were measured by standard assessment scales. Using median value of GI and EI scores as cutoff values, subjects were categorized into four groups. Among different GI-EI groups, acute stress reactivity was similar but salivary Cortisol (especially post stressor level) and perceived stress level was a differentiating factor. High level of EI was associated inversely with acute and chronic perceived stress level. Significant correlation was found between acute and chronic perceived stress levels. Level of general intelligence showed no relation to acute or chronic stress levels as well as acute stress reactivity. The differences in various groups of GI and EI had no effect on the baseline and post stress performance on Sternberg memory test and all the three conditions of Stroop test. In conclusion emotional intelligence as an attribute is better suited to handle day to day acute stress and chronic perceived stress.

Hepatotoxic effects of fenofibrate in spontaneously hypertensive rats expressing human C-reactive protein

Czech Academy of Sciences Publication Activity Database

Škop, V.; Trnovská, J.; Oliyarnyk, O.; Marková, I.; Malínská, H.; Kazdová, L.; Zídek, Václav; Landa, Vladimír; Mlejnek, Petr; Šimáková, Miroslava; Kůdela, M.; Pravenec, Michal; Šilhavý, Jan

2016-01-01

Roč. 65, č. 6 (2016), s. 891-899 ISSN 0862-8408 R&D Projects: GA MZd(CZ) NT14325 Institutional support: RVO:67985823 Keywords : fenofibrate * rosuvastatin * C-reactive protein * transgenic * spontaneously hypertensive rat * inflammation * hepatotoxic Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.461, year: 2016

Effect of levamisole and methisoprinol on in vitro lymphocyte reactivity in chronically irradiated subjects and patients affected by neoplasias

Energy Technology Data Exchange (ETDEWEB)

Campo, M.; Chiavaro, I.; Canfarotta, C.; Stivala, F.; Berrardini, A.

1982-01-01

The data of this experiment show that Levamisole moderately stimulates T-lymphocyte proliferation and efficiency in vitro and methisoprinol markedly does so when both drugs act in combination with PHA in subjects with severely impaired cell-mediated responsiveness, whereas they do not exert any effect on lymphocytes in normal subjects. B-lymphocyte in vitro responsiveness does not appear to be affected by the immunomodulators, except for some cases of cancer of the stomach wherein B-lymphocyte responsiveness is stimulated in vitro by Levamisole and more evidently by Methisoprinol. These data support the use of Methisoprinol or Levamisole in therapy, and further investigations regarding the mechanisms whereby they might act and the dose-effect relationship which might show to be important for the type of desired immunomodulation would appear appropriate.

Effect of levamisole and methisoprinol on in vitro lymphocyte reactivity in chronically irradiated subjects and patients affected by neoplasias

International Nuclear Information System (INIS)

Campo, M.; Chiavaro, I.; Canfarotta, C.; Stivala, F.; Berrardini, A.

1982-01-01

The data of this experiment show that Levamisole moderately stimulates T-lymphocyte proliferation and efficiency in vitro and methisoprinol markedly does so when both drugs act in combination with PHA in subjects with severely impaired cell-mediated responsiveness, whereas they do not exert any effect on lymphocytes in normal subjects. B-lymphocyte in vitro responsiveness does not appear to be affected by the immunomodulators, except for some cases of cancer of the stomach wherein B-lymphocyte responsiveness is stimulated in vitro by Levamisole and more evidently by Methisoprinol. These data support the use of Methisoprinol or Levamisole in therapy, and further investigations regarding the mechanisms whereby they might act and the dose-effect relationship which might show to be important for the type of desired immunomodulation would appear appropriate

Distress tolerance and physiological reactivity to stress predict women's problematic alcohol use.

Science.gov (United States)

Holzhauer, Cathryn Glanton; Wemm, Stephanie; Wulfert, Edelgard

2017-06-01

Research has shown that measures of reactivity to distress-including distress tolerance and physiological reactivity to stress-are dysregulated in women who misuse alcohol. These variables may interact and create a risk profile for young adult women, reflecting patterns of stress reactivity that confer a risk for alcohol misuse. The current study tested this hypothesis by examining the independent and interactive associations of subjective distress tolerance, behavioral distress tolerance, and physiological stress reactivity with women's alcohol misuse. The study was conducted with a sample of 91 college women recruited on a large northeastern university campus. Results showed that subjective levels of distress tolerance and physiological reactivity to stress (skin conductance reactivity, SCR), but not behavioral distress tolerance, were independently associated with alcohol misuse. In addition, subjective distress tolerance moderated the relationship between SCR and negative alcohol-related consequences. Specifically, women with low physiological reactivity (SCR) to a stressful task and greater urge to quickly rid themselves of distress (low subjective distress tolerance) endorsed a significantly greater number of adverse consequences from their alcohol use. These results extend prior findings by showing that, even among a nonclinical sample of women, lower stress reactivity in combination with low subjective distress tolerance is associated with increased risk for various drinking-related negative consequences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Synergistic effect on co-gasification reactivity of biomass-petroleum coke blended char.

Science.gov (United States)

Wei, Juntao; Guo, Qinghua; Gong, Yan; Ding, Lu; Yu, Guangsuo

2017-06-01

In this work, effects of gasification temperature (900°C-1100°C) and blended ratio (3:1, 1:1, 1:3) on reactivity of petroleum coke and biomass co-gasification were studied in TGA. Quantification analysis of active AAEM transformation and in situ investigation of morphological structure variations in gasification were conducted respectively using inductively coupled plasma optical emission spectrometer and heating stage microscope to explore synergistic effect on co-gasification reactivity. The results indicated that char gasification reactivity was enhanced with increasing biomass proportion and gasification temperature. Synergistic effect on co-gasification reactivity was presented after complete generation of biomass ash, and gradually weakened with increasing temperature from 1000°C to 1100°C after reaching the most significant value at 1000°C. This phenomenon was well related with the appearance of molten biomass ash rich in glassy state potassium and the weakest inhibition effect on active potassium transformation during co-gasification at the temperature higher than 1000°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

The ionising radiation effect on reactivation of antibiotics

International Nuclear Information System (INIS)

Dikij, I.L.; Manskij, A.A.; Krasnopyorova, A.P.

2002-01-01

The effect of gamma-radiation on the molecular structure of antibiotics was studied with a view to extending their useful life beyond the current expiration period. The following antibiotics were examined: penicillin, bicillin-3,5, streptomycine, and ampioxe. The samples were irradiated by Co-60 gamma-radiation from a research irradiator. Doses of 0.1, 1, 5, 7, and 10 Gy were applied. The processes were elucidated using the classical method of 2-divisible serial dilutions and IR-spectroscopy. All the measurements were carried out at 300 K. The IR-spectra revealed that the chemical structure of new and old antibiotics is identical; the change in the antibiotic activity is generally a result of deformation of the molecule or change in its conformation; the reactivation process returns the molecule to its previous state and the activity of antibiotic after reactivation meets established standards. Hence, this method can be used for the reactivation of expired antibiotics

Effect of Frustration on Brain Activation Pattern in Subjects with Different Temperament.

Science.gov (United States)

Bierzynska, Maria; Bielecki, Maksymilian; Marchewka, Artur; Debowska, Weronika; Duszyk, Anna; Zajkowski, Wojciech; Falkiewicz, Marcel; Nowicka, Anna; Strelau, Jan; Kossut, Malgorzata

2015-01-01

In spite of the prevalence of frustration in everyday life, very few neuroimaging studies were focused on this emotional state. In the current study we aimed to examine effects of frustration on brain activity while performing a well-learned task in participants with low and high tolerance for arousal. Prior to the functional magnetic resonance imaging session, the subjects underwent 2 weeks of Braille reading training. Frustration induction was obtained by using a novel highly difficult tactile task based on discrimination of Braille-like raised dots patterns and negative feedback. Effectiveness of this procedure has been confirmed in a pilot study using galvanic skin response and questionnaires. Brain activation pattern during tactile discrimination task before and after frustration were compared directly. Results revealed changes in brain activity in structures mostly reported in acute stress studies: striatum, cingulate cortex, insula, middle frontal gyrus and precuneus and in structures engaged in tactile Braille discrimination: SI and SII. Temperament type affected activation pattern. Subjects with low tolerance for arousal showed higher activation in the posterior cingulate gyrus, precuneus, and inferior parietal lobule than high reactivity group. Even though performance in the discrimination trials following frustration was unaltered, we observed increased activity of primary and secondary somatosensory cortex processing the tactile information. We interpret this effect as an indicator of additional involvement required to counteract the effects of frustration.

Modeling food matrix effects on chemical reactivity: Challenges and perspectives.

Science.gov (United States)

Capuano, Edoardo; Oliviero, Teresa; van Boekel, Martinus A J S

2017-06-29

The same chemical reaction may be different in terms of its position of the equilibrium (i.e., thermodynamics) and its kinetics when studied in different foods. The diversity in the chemical composition of food and in its structural organization at macro-, meso-, and microscopic levels, that is, the food matrix, is responsible for this difference. In this viewpoint paper, the multiple, and interconnected ways the food matrix can affect chemical reactivity are summarized. Moreover, mechanistic and empirical approaches to explain and predict the effect of food matrix on chemical reactivity are described. Mechanistic models aim to quantify the effect of food matrix based on a detailed understanding of the chemical and physical phenomena occurring in food. Their applicability is limited at the moment to very simple food systems. Empirical modeling based on machine learning combined with data-mining techniques may represent an alternative, useful option to predict the effect of the food matrix on chemical reactivity and to identify chemical and physical properties to be further tested. In such a way the mechanistic understanding of the effect of the food matrix on chemical reactions can be improved.

Analysis Of Temperature Effects On Reactivity Of The Rsg-Gas Core Using Silicide Fuels

International Nuclear Information System (INIS)

Surbakti, Tukiran; Pinem, Surian

2001-01-01

RSG-GAS has been operating using new silicide fuels so that it is necessary to estimate and to measure the effect of temperature on reactivity of the core. The parameters to be determined due to temperature effect are reactivity coefficient of moderator temperature, temperature coefficient of fuel element and power reactivity coefficient. By doing a couple compensation method, determination of reactivity coefficient as well as the reactivity coefficient of moderator temperature can be obtained. Furthermore, coefficient of the reactivity was successfully estimated using the combination of WIMS-D4 and Batan-2DIFF. The cell calculation was done by using WIMS-D4 code to get macroscopic cross section and Batan-2DIFF code is used for core calculation. The calculation and experimental results of reactivity coefficient do not show any deviation from RSG-GAS safety margin. The results are -2,84 sen/ o C, -1,29 sen/MW and -0,64 sen/ o C for reactivity coefficients of temperature, power, fuel element and moderator temperature, respectively. All of 3 parameters are absolutely met with safety criteria

Effect of reactive feedback on the transverse mode coupling instability

International Nuclear Information System (INIS)

Myers, S.

1984-08-01

An important and realistic test to examine the effect of reactive feedback on the transverse mode coupling instability could be performed at PEP using the existing feedback system with some minor modifications. This test would of necessity take place at low energy and low synchrotron tune. Such an experiment is of great importance for the design of the LEP reactive feedback system and for the ultimate evaluation of LEP performance

Development of perturbation theory expressions for the evaluation of reactivity effects and sensitivity coefficient of reactivity effect to the group cross-sections on the basis of improved coarse mesh method for 3D diffusion problem

International Nuclear Information System (INIS)

Seregin, A.S.

2000-01-01

In the paper the formulae for perturbation theory functionals calculation are given and equations are based on improved coarse mesh discretization of diffusion problem in 3-dimensional geometry (Hex-Z). Expressions for the reactivity effect components and reactivity coefficients, written in the framework of the first order perturbation theory, are presented. On this basis the formulae for estimation of the sensitivity coefficients of different reactivity effects group cross-sections were derived. Expressions for the reactivity effect and its components obtained in the framework of the strict perturbation theory, are also presented in the paper. (author)

Respuesta hemodinámica al estrés mental y físico en sujetos normotensos hiperreactivos: Efectos del Betabloqueo Cardiovascular response to mental and physical stress in hyper-reactive normotensive subjects: Beta blockade effect

Directory of Open Access Journals (Sweden)

Julio Przybylski

2004-10-01

Full Text Available El objetivo de nuestro trabajo fue estudiar la reactividad cardiovascular en personas sanas normotensas sin medicación, mediante la técnica, de Stroop de conflicto entre el color y la palabra (SCWCT, la respuesta anticipatoria de la presión arterial con el ejercicio (RA y la prueba ergométrica graduada (PEG. Se analizó el efecto de un betabloqueante beta1 selectivo: bisoprolol (B sobre la reactividad cardiovascular al estrés mental (EM y físico en personas hiperreactivas. Se estudiaron 42 personas, de los cuales fueron incluidas sólo 30 (21 mujeres y 9 varones que resultaron hiperreactivas, con una edad media de 42.5 años. Los mayores valores de la presión arterial sistólica (PAS y diastólica (PAD durante el EM fueron tomados como medida de reactividad, considerándose como respuesta hiperreactiva un aumento de 30 mm de Hg o mayor y/o 15 mm de Hg o mayor respectivamente. El efecto de una dosis diaria oral de 5 mg de B vs placebo (P fue estudiado en forma prospectiva, randomizada y doble ciego. Se analizaron los datos acerca de la reactividad en el SCWCT mediante el test exacto de Fisher. En los resultados, se observó una menor sensibilidad de RA y PEG vs SCWCT. Las 15 personas que recibieron P continuaron hiperreactivas en tanto que 6 de las 15 personas tratadas con B dejaron de ser reactivas (pThe aim of our study was to evaluate the cardiovascular reactivity in healthy normotensive subjects without medication, using mental and physical stress techniques: Stroop color word conflict test (SCWCT, anticipatory blood pressure response to exercise (ARE and stress testing (ST. We analized the effects of a selective beta 1 betablocker: bisoprolol (B on cardiovascular reactivity in our subjects (s. We studied 42 s, but only 30 (21 females and 9 males were included who were hyperreactives. The mean age was 42,5 years. The higher values of systolic (SBP and diastolic blood pressure (DBP during the mental stress (MS were taken as a measure of

Boosting recovery rather than buffering reactivity: Higher stress-induced oxytocin secretion is associated with increased cortisol reactivity and faster vagal recovery after acute psychosocial stress.

Science.gov (United States)

Engert, Veronika; Koester, Anna M; Riepenhausen, Antje; Singer, Tania

2016-12-01

Animal models and human studies using paradigms designed to stimulate endogenous oxytocin release suggest a stress-buffering role of oxytocin. We here examined the involvement of stress-induced peripheral oxytocin secretion in reactivity and recovery phases of the human psychosocial stress response. Healthy male and female participants (N=114) were subjected to a standardized laboratory stressor, the Trier Social Stress Test. In addition to plasma oxytocin, cortisol was assessed as a marker of hypothalamic-pituitary-adrenal (HPA-) axis activity, alpha-amylase and heart rate as markers of sympathetic activity, high frequency heart rate variability as a marker of vagal tone and self-rated anxiety as an indicator of subjective stress experience. On average, oxytocin levels increased by 51% following psychosocial stress. The stress-induced oxytocin secretion, however, did not reduce stress reactivity. To the contrary, higher oxytocin secretion was associated with greater cortisol reactivity and peak cortisol levels in both sexes. In the second phase of the stress response the opposite pattern was observed, with higher oxytocin secretion associated with faster vagal recovery. We suggest that after an early stage of oxytocin and HPA-axis co-activation, the stress-reducing action of oxytocin unfolds. Due to the time lag it manifests as a recovery-boosting rather than a reactivity-buffering effect. By reinforcing parasympathetic autonomic activity, specifically during stress recovery, oxytocin may provide an important protective function against the health-compromising effects of sustained stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Preventative Ankle Taping on Planned Change-of-Direction and Reactive Agility Performance and Ankle Muscle Activity in Basketballers

Directory of Open Access Journals (Sweden)

Matthew D. Jeffriess, Adrian B. Schultz, Tye S. McGann, Samuel J. Callaghan, Robert G. Lockie

2015-12-01

Full Text Available This study investigated the effects of preventative ankle taping on planned change-of-direction and reactive agility performance and peak ankle muscle activity in basketballers. Twenty male basketballers (age = 22.30 ± 3.97 years; height = 1.84 ± 0.09 meters; body mass = 85.96 ± 11.88 kilograms with no ankle pathologies attended two testing sessions. Within each session, subjects completed six planned and six reactive randomized trials (three to the left and three to the right for each condition of the Y-shaped agility test, which was recorded by timing lights. In one session, subjects had both ankles un-taped. In the other, both ankles were taped using a modified subtalar sling. Peak tibialis anterior, peroneus longus (PL, peroneus brevis (PB, and soleus muscle activity was recorded for both the inside and outside legs across stance phase during the directional change, which was normalized against 10-meter sprint muscle activity (nEMG. Both the inside and outside cut legs during the change-of-direction step were investigated. Repeated measures ANOVA determined performance time and nEMG differences between un-taped and taped conditions. There were no differences in planned change-of-direction or reactive agility times between the conditions. Inside cut leg PL nEMG decreased when taped for the planned left, reactive left, and reactive right cuts (p = 0.01. Outside leg PB and soleus nEMG increased during the taped planned left cut (p = 0.02. There were no other nEMG changes during the cuts with taping. Taping did not affect change-of-direction or agility performance. Inside leg PL activity was decreased, possibly due to the tape following the line of muscle action. This may reduce the kinetic demand for the PL during cuts. In conclusion, ankle taping did not significantly affect planned change-of-direction or reactive agility performance, and did not demonstrate large changes in activity of the muscle complex in healthy basketballers.

Time to wake up: reactive countermeasures to sleep inertia.

Science.gov (United States)

Hilditch, Cassie J; Dorrian, Jillian; Banks, Siobhan

2016-12-07

Sleep inertia is the period of impaired performance and grogginess experienced after waking. This period of impairment is of concern to workers who are on-call, or nap during work hours, and need to perform safety-critical tasks soon after waking. While several studies have investigated the best sleep timing and length to minimise sleep inertia effects, few have focused on countermeasures -especially those that can be implemented after waking (i.e. reactive countermeasures). This structured review summarises current literature on reactive countermeasures to sleep inertia such as caffeine, light, and temperature and discusses evidence for the effectiveness and operational viability of each approach. Current literature does not provide a convincing evidence-base for a reactive countermeasure. Caffeine is perhaps the best option, although it is most effective when administered prior to sleep and is therefore not strictly reactive. Investigations into light and temperature have found promising results for improving subjective alertness; further research is needed to determine whether these countermeasures can also attenuate performance impairment. Future research in this area would benefit from study design features highlighted in this review. In the meantime, it is recommended that proactive sleep inertia countermeasures are used, and that safety-critical tasks are avoided immediately after waking.

Cue reactivity towards shopping cues in female participants.

Science.gov (United States)

Starcke, Katrin; Schlereth, Berenike; Domass, Debora; Schöler, Tobias; Brand, Matthias

2013-03-01

Background and aims It is currently under debate whether pathological buying can be considered as a behavioural addiction. Addictions have often been investigated with cue-reactivity paradigms to assess subjective, physiological and neural craving reactions. The current study aims at testing whether cue reactivity towards shopping cues is related to pathological buying tendencies. Methods A sample of 66 non-clinical female participants rated shopping related pictures concerning valence, arousal, and subjective craving. In a subgroup of 26 participants, electrodermal reactions towards those pictures were additionally assessed. Furthermore, all participants were screened concerning pathological buying tendencies and baseline craving for shopping. Results Results indicate a relationship between the subjective ratings of the shopping cues and pathological buying tendencies, even if baseline craving for shopping was controlled for. Electrodermal reactions were partly related to the subjective ratings of the cues. Conclusions Cue reactivity may be a potential correlate of pathological buying tendencies. Thus, pathological buying may be accompanied by craving reactions towards shopping cues. Results support the assumption that pathological buying can be considered as a behavioural addiction. From a methodological point of view, results support the view that the cue-reactivity paradigm is suited for the investigation of craving reactions in pathological buying and future studies should implement this paradigm in clinical samples.

Reactivity effect of spent fuel due to spatial distributions for coolant temperature and burnup

Energy Technology Data Exchange (ETDEWEB)

Hayashi, T.; Yamane, Y. [Nagoya Univ., Dept. of Nuclear Engineering, Nagoya, Aichi (Japan); Suyama, K. [OECD/NEA, Paris (France); Mochizuki, H. [Japan Research Institute, Ltd., Tokyo (Japan)

2002-03-01

We investigated the reactivity effect of spent fuel caused by the spatial distributions of coolant temperature and burnup by using the integrated burnup calculation code system SWAT. The reactivity effect which arises from taking account of the spatial coolant temperature distribution increases as the average burnup increases, and reaches the maximum value of 0.69%{delta}k/k at 50 GWd/tU when the burnup distribution is concurrently considered. When the burnup distribution is ignored, the reactivity effect decreases by approximately one-third. (author)

Effects of age on reactive capacity and nigrostriatal dopamine function

International Nuclear Information System (INIS)

Gilliam, P.E.

1984-01-01

This investigation examined the effects of aging on reactive capacity (reaction time), and striatal dopamine function in the same animals. Twenty, 3 month old, and twenty, 24 month old, male Sprague-Dawley rats were trained in a reactive capacity test to quickly release a lever, in response to an auditory and visual stimulus, in order to avoid footshocks. The young animals were tested at 3, 6, and 9 months of age, while the Old animals were tested at 18, 21, and 24 months of age. Twenty-four hours after the last testing session the animals were sacrificed and their striata dissected for biochemical assays. A [ 3 H]-spiperone receptor binding assay was performed to determine the density and affinity of striatial D-2 receptors. It was hypothesized that the improvement in reactive capacity performance of the Old animals over days was due to their ability to compensate for their decrease in receptor density by an increase in the production and utilization of dopamine. Significant positive correlations were also found between reactive capacity performance and receptor density as well as between reactive capacity and the ratio of DOPAC + HVA/DA

Moderator temperature effects on reactivity of HEU core of MNSR

International Nuclear Information System (INIS)

Ahmad, Siraj-ul-Islam; Sahibzada, Tasveer Muhammad

2012-01-01

Highlights: ► The MNSR core was analyzed to see the cross section effects on moderator temperature coefficient of reactivity. ► WIMS-D code was used for cell calculations. ► The 3D diffusion theory code PRIDE was first validated using IAEA benchmark problem and then used for analysis of MNSR. ► The differences among results for various libraries were discussed. -- Abstract: In this article we report on analyses that were performed to investigate the influence of cross section differences among libraries released by various centers on reactivity of Miniature Neutron Source Reactors. The 3D model of the core was developed with WIMS-D and PRIDE codes and six cross section libraries were used including JENDL-3.2, JEF-2.2, JEFF-3.3, ENDF/B-VI and ENDF/B-VII, and IAEA library. It was observed that all the libraries predict the reactivity within 10%, with IAEA library giving minimum reactivity worth, and JEF-2.2 data library resulted in highest worth.

Reactive Kripke semantics

CERN Document Server

Gabbay, Dov M

2013-01-01

This text offers an extension to the traditional Kripke semantics for non-classical logics by adding the notion of reactivity. Reactive Kripke models change their accessibility relation as we progress in the evaluation process of formulas in the model. This feature makes the reactive Kripke semantics strictly stronger and more applicable than the traditional one. Here we investigate the properties and axiomatisations of this new and most effective semantics, and we offer a wide landscape of applications of the idea of reactivity. Applied topics include reactive automata, reactive grammars, rea

Spectral fine structure effects on material and doppler reactivity worth

International Nuclear Information System (INIS)

Greenspan, E.; Karni, Y.

1975-01-01

New formulations concerning the fine structure effects on the reactivity worth of resonances are developed and conclusions are derived following the extension to more general types of perturbations which include: the removal of resonance material at finite temperatures and the temperature variation of part of the resonance material. It is concluded that the flux method can overpredict the reactivity worth of resonance materials more than anticipated. Calculations on the Doppler worth were carried out; the results can be useful for asessing the contribution of the fine structure effects to the large discrepancy that exists between the calculated and measured small sample Doppler worths. (B.G.)

The Influence of Executive Functioning on Facial and Subjective Pain Responses in Older Adults

Science.gov (United States)

2016-01-01

Cognitive decline is known to reduce reliability of subjective pain reports. Although facial expressions of pain are generally considered to be less affected by this decline, empirical support for this assumption is sparse. The present study therefore examined how cognitive functioning relates to facial expressions of pain and whether cognition acts as a moderator between nociceptive intensity and facial reactivity. Facial and subjective responses of 51 elderly participants to mechanical stimulation at three intensities levels (50 kPa, 200 kPa, and 400 kPa) were assessed. Moreover, participants completed a neuropsychological examination of executive functioning (planning, cognitive inhibition, and working memory), episodic memory, and psychomotor speed. The results showed that executive functioning has a unique relationship with facial reactivity at low pain intensity levels (200 kPa). Moreover, cognitive inhibition (but not other executive functions) moderated the effect of pressure intensity on facial pain expressions, suggesting that the relationship between pressure intensity and facial reactivity was less pronounced in participants with high levels of cognitive inhibition. A similar interaction effect was found for cognitive inhibition and subjective pain report. Consequently, caution is needed when interpreting facial (as well as subjective) pain responses in individuals with a high level of cognitive inhibition. PMID:27274618

Cross-reactive microbial peptides can modulate HIV-specific CD8+ T cell responses.

Directory of Open Access Journals (Sweden)

Christopher W Pohlmeyer

Full Text Available Heterologous immunity is an important aspect of the adaptive immune response. We hypothesized that this process could modulate the HIV-1-specific CD8+ T cell response, which has been shown to play an important role in HIV-1 immunity and control. We found that stimulation of peripheral blood mononuclear cells (PBMCs from HIV-1-positive subjects with microbial peptides that were cross-reactive with immunodominant HIV-1 epitopes resulted in dramatic expansion of HIV-1-specific CD8+ T cells. Interestingly, the TCR repertoire of HIV-1-specific CD8+ T cells generated by ex vivo stimulation of PBMCs using HIV-1 peptide was different from that of cells stimulated with cross-reactive microbial peptides in some HIV-1-positive subjects. Despite these differences, CD8+ T cells stimulated with either HIV-1 or cross-reactive peptides effectively suppressed HIV-1 replication in autologous CD4+ T cells. These data suggest that exposure to cross-reactive microbial antigens can modulate HIV-1-specific immunity.

Effect of frustration on brain activation pattern in subjects with different temperament.

Directory of Open Access Journals (Sweden)

Maria eBierzynska

2016-01-01

Full Text Available In spite of the prevalence of frustration in everyday life, very few neuroimaging studies were focused on this emotional state. In the current study we aimed to examine effects of frustration on brain activity while performing a well-learned task in participants with low and high tolerance for arousal. Prior to the functional magnetic resonance imaging (fMRI session, the subjects underwent two weeks of Braille reading training. Frustration induction was obtained by using a novel highly difficult tactile task based on discrimination of Braille-like raised dots patterns and negative feedback. Effectiveness of this procedure has been confirmed in a pilot study using galvanic skin response (GSR and questionnaires. Brain activation pattern during tactile discrimination task before and after frustration were compared directly. Results revealed changes in brain activity in structures mostly reported in acute stress studies: striatum, cingulate cortex, insula, middle frontal gyrus and precuneus and in structures engaged in tactile Braille discrimination: SI and SII. Temperament type affected activation pattern. Subjects with low tolerance for arousal showed higher activation in the posterior cingulate gyrus, precuneus and inferior parietal lobule (IPL than high reactivity group. Even though performance in the discrimination trials following frustration was unaltered, we observed increased activity of primary and secondary somatosensory cortex processing the tactile information. We interpret this effect as an indicator of additional involvement required to counteract the effects of frustration.

Effect of processing temperature on the bitumen/MDI-PEG reactivity

Energy Technology Data Exchange (ETDEWEB)

Martin-Alfonso, M.J.; Partal, P.; Navarro, F.J.; Garcia-Morales, M. [Departamento de Ingenieria Quimica, Facultad de Ciencias Experimentales, Campus de ' El Carmen' , Universidad de Huelva, 21071, Huelva (Spain); Bordado, J.C.M. [Chemical and Biological Engineering Department, IBB, Instituto Superior Tecnico, Av. Rovisco Pais 1049-001 Lisbon (Portugal); Diogo, A.C. [Materials Engineering Department, Instituto Superior Tecnico, Av. Rovisco Pais 1049-001 Lisbon (Portugal)

2009-04-15

Reactive polymers are lately gaining acceptance to give added value to a residue of the crude oil refining process such as bitumen. The resulting material should display enhanced mechanical properties to be considered for advanced applications in construction. In the present paper, we report the effect of processing temperature on the reaction between bitumen compounds and an isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4'-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol (PEG). Rheokinetics experiments, viscosity measurements at 60 C, atomic force microscopy (AFM) characterization, thin layer chromatography (TLC-FID) analysis and thermogravimetric studies (TGA) were performed on the reactive polymer and on samples of MDI-PEG modified bitumen containing 2 wt.% of the polymer. Results showed the existence of an optimum processing temperature arisen as a consequence of opposite effects: microstructural availability for the formation of a polymer-bitumen network, reaction ability and polymer thermal degradation. Consequently, this study aims to serve as a guideline for the refining and asphalt industries facing the stage of selecting the optimum processing parameters. (author)

Environmental life cycle assessment of permeable reactive barriers: effects of construction methods, reactive materials and groundwater constituents.

Science.gov (United States)

Mak, Mark S H; Lo, Irene M C

2011-12-01

The effects of the construction methods, materials of reactive media and groundwater constituents on the environmental impacts of a permeable reactive barrier (PRB) were evaluated using life cycle assessment (LCA). The PRB is assumed to be installed at a simulated site contaminated by either Cr(VI) alone or Cr(VI) and As(V). Results show that the trench-based construction method can reduce the environmental impacts of the remediation remarkably compared to the caisson-based method due to less construction material consumption by the funnel. Compared to using the zerovalent iron (Fe(0)) and quartz sand mixture, the use of the Fe(0) and iron oxide-coated sand (IOCS) mixture can reduce the environmental impacts. In the presence of natural organic matter (NOM) in groundwater, the environmental impacts generated by the reactive media were significantly increased because of the higher usage of Fe(0). The environmental impacts are lower by using the Fe(0) and IOCS mixture in the groundwater with NOM, compared with using the Fe(0) and quartz sand mixture. Since IOCS can enhance the removal efficiency of Cr(VI) and As(V), the usage of the Fe(0) can be reduced, which in turn reduces the impacts induced by the reactive media.

Differential effects of painful and non-painful stimulation on tactile processing in fibromyalgia syndrome and subjects with masochistic behaviour.

Directory of Open Access Journals (Sweden)

Bettina Pollok

Full Text Available BACKGROUND: In healthy subjects repeated tactile stimulation in a conditioning test stimulation paradigm yields attenuation of primary (S1 and secondary (S2 somatosensory cortical activation, whereas a preceding painful stimulus results in facilitation. METHODOLOGY/PRINCIPAL FINDINGS: Since previous data suggest that cognitive processes might affect somatosensory processing in S1, the present study aims at investigating to what extent cortical reactivity is altered by the subjective estimation of pain. To this end, the effect of painful and tactile stimulation on processing of subsequently applied tactile stimuli was investigated in patients with fibromyalgia syndrome (FMS and in subjects with masochistic behaviour (MB by means of a 122-channel whole-head magnetoencephalography (MEG system. Ten patients fulfilling the criteria for the diagnosis of FMS, 10 subjects with MB and 20 control subjects matched with respect to age, gender and handedness participated in the present study. Tactile or brief painful cutaneous laser stimuli were applied as conditioning stimulus (CS followed by a tactile test stimulus (TS 500 ms later. While in FMS patients significant attenuation following conditioning tactile stimulation was evident, no facilitation following painful stimulation was found. By contrast, in subjects with MB no attenuation but significant facilitation occurred. Attenuation as well as facilitation applied to cortical responses occurring at about 70 ms but not to early S1 or S2 responses. Additionally, in FMS patients the amount of attenuation was inversely correlated with catastrophizing tendency. CONCLUSION: The present results imply altered cortical reactivity of the primary somatosensory cortex in FMS patients and MB possibly reflecting differences of individual pain experience.

Study on the effect of moderator density reactivity for Kartini reactor

International Nuclear Information System (INIS)

Budi Rohman; Widarto

2009-01-01

One of important characteristics of water-cooled reactors is the change of reactivity due to change in the density of coolant or moderator. This parameter generally has negative value and it has significant role in preventing the excursion of power during operation. Many thermal-hydraulic codes for nuclear reactors require this parameter as the input to account for reactivity feedback due to increase in moderator voids and the subsequent decrease in moderator density during operation. Kartini reactor is cooled and moderated by water, therefore, it is essential to study the effect of the change in moderator density as well as to determine the value of void or moderator density reactivity coefficient in order to characterize its behavior resulting from the presence of vapor or change of moderator density during operation. Analysis by MCNP code shows that the reactivity of core is decreasing with the decrease in moderator density. The analysis estimates the void or moderator density reactivity coefficient for Kartini Reactor to be -2.17×10-4 Δρ/ % void . (author)

The effect of core configuration on temperature coefficient of reactivity in IRR-1

Energy Technology Data Exchange (ETDEWEB)

Bettan, M.; Silverman, I.; Shapira, M.; Nagler, A. [Soreq Nuclear Research Center, Yavne (Israel)

1997-08-01

Experiments designed to measure the effect of coolant moderator temperature on core reactivity in an HEU swimming pool type reactor were performed. The moderator temperature coefficient of reactivity ({alpha}{sub {omega}}) was obtained and found to be different in two core loadings. The measured {alpha}{sub {omega}} of one core loading was {minus}13 pcm/{degrees}C at the temperature range of 23-30{degrees}C. This value of {alpha}{sub {omega}} is comparable to the data published by the IAEA. The {alpha}{sub {omega}} measured in the second core loading was found to be {minus}8 pcm/{degrees}C at the same temperature range. Another phenomenon considered in this study is core behavior during reactivity insertion transient. The results were compared to a core simulation using the Dynamic Simulator for Nuclear Power Plants. It was found that in the second core loading factors other than the moderator temperature influence the core reactivity more than expected. These effects proved to be extremely dependent on core configuration and may in certain core loadings render the reactor`s reactivity coefficient undesirable.

Reactivity-flooding effect of the MNSR inner irradiation sites

International Nuclear Information System (INIS)

Khamis, I.; Khattab, K.

1999-01-01

For the purpose of safety assessments, evaluation of the reactivity effects of inner irradiation sites, being flooded with water in the MNSR reactor was conducted both numerically and experimentally. Measured and calculated effect of different combination of inner irradiation sites being flooded with water was evaluated numerically and experimentally. Good agreement between measurement and calculated results were obtained

Natural honey lowers plasma glucose, C-reactive protein, homocysteine, and blood lipids in healthy, diabetic, and hyperlipidemic subjects: comparison with dextrose and sucrose.

Science.gov (United States)

Al-Waili, Noori S

2004-01-01

This study included the following experiments: (1) effects of dextrose solution (250 mL of water containing 75 g of dextrose) or honey solution (250 mL of water containing 75 g of natural honey) on plasma glucose level (PGL), plasma insulin, and plasma C-peptide (eight subjects); (2) effects of dextrose, honey, or artificial honey (250 mL of water containing 35 g of dextrose and 40 g of fructose) on cholesterol and triglycerides (TG) (nine subjects); (3) effects of honey solution, administered for 15 days, on PGL, blood lipids, C-reactive protein (CRP), and homocysteine (eight subjects); (4) effects of honey or artificial honey on cholesterol and TG in six patients with hypercholesterolemia and five patients with hypertriglyceridemia; (5) effects of honey for 15 days on blood lipid and CRP in five patients with elevated cholesterol and CRP; (6) effects of 70 g of dextrose or 90 g of honey on PGL in seven patients with type 2 diabetes mellitus; and (7) effects of 30 g of sucrose or 30 g of honey on PGL, plasma insulin, and plasma C-peptide in five diabetic patients. In healthy subjects, dextrose elevated PGL at 1 (53%) and 2 (3%) hours, and decreased PGL after 3 hours (20%). Honey elevated PGL after 1 hour (14%) and decreased it after 3 hours (10%). Elevation of insulin and C-peptide was significantly higher after dextrose than after honey. Dextrose slightly reduced cholesterol and low-density lipoprotein-cholesterol (LDL-C) after 1 hour and significantly after 2 hours, and increased TG after 1, 2, and 3 hours. Artificial honey slightly decreased cholesterol and LDL-C and elevated TG. Honey reduced cholesterol, LDL-C, and TG and slightly elevated high-density lipoprotein-cholesterol (HDL-C). Honey consumed for 15 days decreased cholesterol (7%), LDL-C (1%), TG (2%), CRP (7%), homocysteine (6%), and PGL (6%), and increased HDL-C (2%). In patients with hypertriglyceridemia, artificial honey increased TG, while honey decreased TG. In patients with hyperlipidemia

Serum lipids modify periodontal infection - C-reactive protein association.

Science.gov (United States)

Haro, Anniina; Saxlin, Tuomas; Suominen, Anna-Liisa; Ylöstalo, Pekka; Leiviskä, Jaana; Tervonen, Tellervo; Knuuttila, Matti

2012-09-01

To investigate whether low-grade inflammation-related factors such as serum low-density (LDL-C) and high-density lipoprotein cholesterol (HDL-C) modify the association between periodontal infection and C-reactive protein. This study was based on a subpopulation of the Health 2000 Survey, which consisted of dentate, non-diabetic, non-rheumatic subjects who were 30-49 years old (n = 2710). The extent of periodontal infection was measured by means of the number of teeth with periodontal pocket ≥4 mm and teeth with periodontal pocket ≥6 mm and systemic inflammation using high sensitive C-reactive protein. The extent of periodontal infection was associated with elevated levels of C-reactive protein among those subjects whose HDL-C value was below the median value of 1.3 mmol/l or LDL-C above the median value of 3.4 mmol/l. Among those with HDL-C ≥ 1.3 mmol/l or LDL-C ≤ 3.4 mmol/l, the association between periodontal infection and serum concentrations of C-reactive protein was practically non-existent. This study suggests that the relation of periodontal infection to the systemic inflammatory condition is more complicated than previously presumed. The findings of this study suggest that the possible systemic effect of periodontal infection is dependent on serum lipid composition. © 2012 John Wiley & Sons A/S.

Supervised exercise training counterbalances the adverse effects of insulin therapy in overweight/obese subjects with type 2 diabetes.

Science.gov (United States)

Balducci, Stefano; Zanuso, Silvano; Cardelli, Patrizia; Salerno, Gerardo; Fallucca, Sara; Nicolucci, Antonio; Pugliese, Giuseppe

2012-01-01

To examine the effect of supervised exercise on traditional and nontraditional cardiovascular risk factors in sedentary, overweight/obese insulin-treated subjects with type 2 diabetes from the Italian Diabetes Exercise Study (IDES). The study randomized 73 insulin-treated patients to twice weekly supervised aerobic and resistance training plus structured exercise counseling (EXE) or to counseling alone (CON) for 12 months. Clinical and laboratory parameters were assessed at baseline and at the end of the study. The volume of physical activity was significantly higher in the EXE versus the CON group. Values for hemoglobin A(1c), BMI, waist circumference, high-sensitivity C-reactive protein, blood pressure, LDL cholesterol, and the coronary heart disease risk score were significantly reduced only in the EXE group. No major adverse events were observed. In insulin-treated subjects with type 2 diabetes, supervised exercise is safe and effective in improving glycemic control and markers of adiposity and inflammation, thus counterbalancing the adverse effects of insulin on these parameters.

Acute effects of inspiratory muscle warm-up on pulmonary function in healthy subjects.

Science.gov (United States)

Özdal, Mustafa

2016-06-15

The acute effects of inspiratory muscle warm-up on pulmonary functions were examined in 26 healthy male subjects using the pulmonary function test (PFT) in three different trials. The control trial (CON) did not involve inspiratory muscle warm-up, while the placebo (IMWp) and experimental (IMW) trials involved inspiratory muscle warm-up. There were no significant changes between the IMWp and CON trials (p>0.05). All the PFT measurements, including slow vital capacity, inspiratory vital capacity, forced vital capacity, forced expiratory volume in one second, maximal voluntary ventilation, and maximal inspiratory pressure were significantly increased by 3.55%, 12.52%, 5.00%, 2.75%, 2.66%, and 7.03% respectively, in the subjects in the IMW trial than those in the CON trial (pcooperation of the upper thorax, neck, and respiratory muscles, and increased level of reactive O2 species in muscle tissue, and potentially improvement of muscle O2 delivery-to-utilization. However, further investigation is required to determine the precise mechanisms responsible from among these candidates. Copyright © 2016 Elsevier B.V. All rights reserved.

Calculation code of heterogeneity effects for analysis of small sample reactivity worth

International Nuclear Information System (INIS)

Okajima, Shigeaki; Mukaiyama, Takehiko; Maeda, Akio.

1988-03-01

The discrepancy between experimental and calculated central reactivity worths has been one of the most significant interests for the analysis of fast reactor critical experiment. Two effects have been pointed out so as to be taken into account in the calculation as the possible cause of the discrepancy; one is the local heterogeneity effect which is associated with the measurement geometry, the other is the heterogeneity effect on the distribution of the intracell adjoint flux. In order to evaluate these effects in the analysis of FCA actinide sample reactivity worth the calculation code based on the collision probability method was developed. The code can handle the sample size effect which is one of the local heterogeneity effects and also the intracell adjoint heterogeneity effect. (author)

Effect of water pipe tobacco smoking on plasma high sensitivity C reactive protein level and endothelial function compared to cigarette smoking

OpenAIRE

Osama Ali Diab; Elzahraa Mohamed Abdelrahim; Mohamed Esmail

2015-01-01

Background: Cigarette smoking is a well known risk factor for cardiovascular disease, however, little is known regarding water pipe (WP) smoking. High sensitivity C-reactive protein (hs-CRP) and flow mediated dilatation (FMD) are well recognized methods to assess cardiovascular risks. Objectives: To study the effect of WP smoking on hs-CRP level and endothelial function compared to cigarette smoking. Methods: The study included 77 male subjects (30 WP smokers, 30 cigarette smokers, and ...

Neurofeedback Effects on Evoked and Induced EEG Gamma Band Reactivity to Drug-related Cues in Cocaine Addiction

Science.gov (United States)

Horrell, Timothy; El-Baz, Ayman; Baruth, Joshua; Tasman, Allan; Sokhadze, Guela; Stewart, Christopher; Sokhadze, Estate

2010-01-01

Introduction Preoccupation with drug and drug-related items is a typical characteristic of cocaine addicted individuals. It has been shown in multiple accounts that prolonged drug use has a profound effect on the EEG recordings of drug addicts when compared to controls during cue reactivity tests. Cue reactivity refers to a phenomenon in which individuals with a history of drug abuse exhibit excessive psychophysiological responses to cues associated with their drug of choice. One of the aims of this pilot study was to determine the presence of an attentional bias to preferentially process drug-related cues using evoked and induced gamma reactivity measures in cocaine addicts before and after biobehavioral treatment based on neurofeedback. Another aim was to show that central SMR amplitude increase and frontal theta control is possible in an experimental outpatient drug users group over 12 neurofeedback sessions. Method Ten current cocaine abusers participated in this pilot research study using neurofeedback combined with Motivational Interviewing sessions. Eight of them completed all planned pre- and post –neurofeedback cue reactivity tests with event-related EEG recording and clinical evaluations. Cue reactivity test represented a visual oddball task with images from the International Affective Picture System and drug-related pictures. Evoked and induced gamma responses to target and non-target drug cues were analyzed using wavelet analysis. Results Outpatient subjects with cocaine addiction completed the biobehavioral intervention and successfully increased SMR while keeping theta practically unchanged in 12 sessions of neurofeedback training. The addition of Motivational Interviewing helped retain patients in the study. Clinical evaluations immediately after completion of the treatment showed decreased self-reports on depression and stress scores, and urine tests collaborated reports of decreased use of cocaine and marijuana. Effects of neurofeedback resulted

Acceptance lowers stress reactivity: Dismantling mindfulness training in a randomized controlled trial.

Science.gov (United States)

Lindsay, Emily K; Young, Shinzen; Smyth, Joshua M; Brown, Kirk Warren; Creswell, J David

2018-01-01

Mindfulness interventions, which train practitioners to monitor their present-moment experience with a lens of acceptance, are known to buffer stress reactivity. Little is known about the active mechanisms driving these effects. We theorize that acceptance is a critical emotion regulation mechanism underlying mindfulness stress reduction effects. In this three-arm parallel trial, mindfulness components were dismantled into three structurally equivalent 15-lesson smartphone-based interventions: (1) training in both monitoring and acceptance (Monitor+Accept), (2) training in monitoring only (Monitor Only), or (3) active control training (Coping control). 153 stressed adults (mean age=32years; 67% female; 53% white, 21.5% black, 21.5% Asian, 4% other race) were randomly assigned to complete one of three interventions. After the intervention, cortisol, blood pressure, and subjective stress reactivity were assessed using a modified Trier Social Stress Test. As predicted, Monitor+Accept training reduced cortisol and systolic blood pressure reactivity compared to Monitor Only and control trainings. Participants in all three conditions reported moderate levels of subjective stress. This study provides the first experimental evidence that brief smartphone mindfulness training can impact stress biology, and that acceptance training drives these effects. We discuss implications for basic and applied research in contemplative science, emotion regulation, stress and coping, health, and clinical interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor α: a meta-analysis.

Science.gov (United States)

Li, Kelei; Huang, Tao; Zheng, Jusheng; Wu, Kejian; Li, Duo

2014-01-01

Previous studies did not draw a consistent conclusion about the effects of marine-derived n-3 polyunsaturated fatty acids (PUFAs) on fasting blood level of C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α). A comprehensive search of Web of Science, PubMed, Embase and Medline (from 1950 to 2013) and bibliographies of relevant articles was undertaken. Sixty-eight RCTs with a total of 4601 subjects were included in the meta-analysis. Marine-derived n-3 PUFAs supplementation showed a lowering effect on Marine-derived n-3 PUFAs supplementation had a significant lowering effect on TNF-α, IL-6 and CRP in three groups of subjects (subjects with chronic non-autoimmune disease, subjects with chronic autoimmune disease and healthy subjects). A significant negative linear relationship between duration and effect size of marine-derived n-3 PUFAs supplementation on fasting blood levels of TNF-α and IL-6 in subjects with chronic non-autoimmune disease was observed, indicating that longer duration of supplementation could lead to a greater lowering effect. A similar linear relationship was also observed for IL-6 levels in healthy subjects. Restricted cubic spline analysis and subgroup analysis showed that the lowering effect of marine-derived n-3 PUFAs on CRP, IL-6 and TNF-α in subjects with chronic non-autoimmune disease became weakened when body mass index was greater than 30 kg/m². The effect of marine-derived n-3 PUFAs from dietary intake was only assessed in subjects with chronic non-autoimmune disease, and a significant lowering effect was observed on IL-6, but not on CRP and TNF-α. Marine-derived n-3 PUFAs supplementation had a significant lowering effect on CRP, IL-6 and TNF-α level. The lowering effect was most effective in non-obese subjects and consecutive long-term supplementation was recommended.

Mother-child language style matching predicts children's and mothers' emotion reactivity.

Science.gov (United States)

Rasmussen, Hannah F; Borelli, Jessica L; Smiley, Patricia A; Cohen, Chloe; Cheung, Ryan Cheuk Ming; Fox, Schuyler; Marvin, Matthew; Blackard, Betsy

2017-05-15

Co-regulation of behavior occurring within parent-child attachment relationships is thought to be the primary means through which children develop the capacity to regulate emotion, an ability that is protective across development. Existing research on parent-child co-regulation focuses predominantly on parent-infant dyads, and operationalizes co-regulation as the matching of facial expressions; however, matching can occur on other behaviors, including vocal tone, body movement, and language. Studies with young children find that greater matching is associated with children's lower emotion reactivity, but with unknown impacts on parents. In this study we examine a recently-developed metric of behavioral matching, language style matching (LSM), a composite measure of the similarity of function word use in spoken or written language between two or more people. We test whether LSM between mothers and their school-aged children is associated with children's and mothers' physiological and subjective emotion reactivity. Children completed a standardized stressor task while their mothers observed; children's and mother's cortisol and cardiovascular reactivity were assessed, as were their subjective reports of emotion reactivity. Following the stressor, children and mothers completed independent interviews about the experience, later assessed for LSM. Higher mother-child LSM was associated with lower emotion reactivity (lower cortisol reactivity, lower reports of negative emotion) for children, and with higher maternal cardiovascular but not cortisol or subjective reactivity. Further, higher LSM was more strongly associated with lower child cortisol reactivity when mothers were more reactive themselves. We conclude that mother-child LSM, thought to reflect a history of co-regulated interaction, confers protective benefits for children, but heightened reactivity for mothers. Copyright © 2016 Elsevier B.V. All rights reserved.

The effects of trait impulsivity on proactive and reactive interference control.

Science.gov (United States)

Xiang, Ling; Chen, Yan; Chen, Antao; Zhang, Fenghua; Xu, Fuming; Wang, Baoxi

2018-02-01

The current study used event-related brain potentials (ERPs) to explore whether self-reported trait impulsivity in healthy individuals might be differentially related to proactive and reactive interference control. Participants with high and low impulsivity (HI and LI, respectively) performed a modified version of the prime-target interference task. Proactive interference control was induced in the mostly incongruent (MI) context and reactive interference control was induced in the mostly congruent (MC) context. Although the behavioral data revealed no difference between HI and LI individuals in terms of the interference effects (incongruent - congruent) under both contexts, the ERP results showed that impulsivity has a different influence on the interference effects under different task contexts. In the MC context, the interference effects on the medial frontal negativity (MFN) and the negative sustained potential (N-SP) were greater, while that on the positive sustained potential (P-SP) were smaller in the HI compared to those in the LI group. This suggests that high levels of impulsivity might be associated with a reduced efficiency of the processes supporting reactive control to resolve interference when interference is not expected. In contrast, the three ERP indices (MFN, P-SP, and N-SP) of interference processing in the MI context were insensitive to variations in impulsivity. This suggests that HI individuals might be as effective as LI individuals in recruiting proactive control for sustained active maintenance of task goals to anticipate and prevent interference throughout the experimental blocks where interference occurs frequently. In conclusion, these results indicate that impulsivity has a more negative influence on reactive interference control than on proactive interference control. Copyright © 2017. Published by Elsevier B.V.

Effect of nonsteroidal antiinflammatory drugs on the C-reactive protein level in rheumatoid arthritis

DEFF Research Database (Denmark)

Tarp, Simon; Bartels, Else M.; Bliddal, Henning

2012-01-01

To evaluate the effects of oral nonsteroidal antiinflammatory drugs (NSAIDs) on C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients, with a prespecified focus on the different NSAIDs.......To evaluate the effects of oral nonsteroidal antiinflammatory drugs (NSAIDs) on C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients, with a prespecified focus on the different NSAIDs....

Effects of proline on photosynthesis, root reactive oxygen species ...

African Journals Online (AJOL)

Effects of 0.2 mM proline applied to saline nutrient solution on biomass, chlorophyll content, photosynthetic parameters, reactive oxygen species and antioxidant enzymes activities of two melon cultivars (cv. Yuhuang and cv. Xuemei) were examined. Results indicate that exogenous proline increased the fresh and dry ...

Effects of poison panel shrinkage and gaps on fuel storage rack reactivity

International Nuclear Information System (INIS)

Boyd, W.A.; Mueller, D.E.

1988-01-01

Fixed poison panels are used in spent fuel rack designs to increase enrichment limits and reduce cell spacing; therefore, assurances that the maximum rack reactivity will meet the design limit (0.95) throughout the lifetime of the racks depend on the continued effectiveness of the poison with time. Industry data have shown that poison panels will shrink under irradiated conditions. From recent data, however, poison panels have been found to have gaps spanning their width after relatively short operating periods. This paper presents results of studies showing the fuel rack reactivity changes associated with poison panel shrinkage and formation of gaps. The discovery of gaps in the fuel rack poison panels at an operating plant raises concerns regarding the effectiveness of the poison over the lifetime of the fuel racks. Studies performed to evaluate the effect of the poison panel shrinkage on reactivity show that reactivity changes from zero to several percent are possible depending on the initial panel size. Results of recent studies show that some gaps can be accommodated in the fuel rack poison panels at the fuel midplane without causing the fuel rack K eff limit to be exceeded. With worst-case assumptions concerning gap size and the number of panels affected, other actions will likely be required to show that the rack K eff design limit will not be exceeded

Planned and reactive agility performance in semiprofessional and amateur basketball players.

Science.gov (United States)

Lockie, Robert G; Jeffriess, Matthew D; McGann, Tye S; Callaghan, Samuel J; Schultz, Adrian B

2014-09-01

Research indicates that planned and reactive agility are different athletic skills. These skills have not been adequately assessed in male basketball players. To define whether 10-m-sprint performance and planned and reactive agility measured by the Y-shaped agility test can discriminate between semiprofessional and amateur basketball players. Ten semiprofessional and 10 amateur basketball players completed 10-m sprints and planned- and reactive-agility tests. The Y-shaped agility test involved subjects sprinting 5 m through a trigger timing gate, followed by a 45° cut and 5-m sprint to the left or right through a target gate. In the planned condition, subjects knew the cut direction. For reactive trials, subjects visually scanned to find the illuminated gate. A 1-way analysis of variance (P basketball players; planned agility did not. To distinguish between male basketball players of different ability levels, agility tests should include a perceptual and decision-making component.

Evaluation of serum C-reactive protein levels in subjects with aggressive and chronic periodontitis and comparison with healthy controls

Science.gov (United States)

Kanaparthy, Aruna; Kanaparthy, Rosaiah; Niranjan, Nandini

2012-01-01

Background: Periodontal subgingival pathogens affect local and systemic immune responses and initiate an acute phase systemic inflammatory response characterized by the release of C-reactive proteins (CRPs). This study has been carried out to evaluate the serum concentration of CRPs, which can be used as a marker of periodontal disease as well as a risk indicator for cardiovascular diseases. Materials and Methods: In a retrospective study a total number of 45 subjects were selected from the outpatient department of periodontics a mean age of 40 years. Based on the periodontal status, the subjects were divided into 3 groups of 15 subjects each. Group I: Control group [with attachment loss (AL) ≤ 2 mm and pocket depth (PD) periodontitis (AL ≤ 5 mm), Group III: chronic periodontitis (AL ≥ 2 mm, PD ≥ 5 mm), which includes moderate and severe periodontitis. The clinical parameters recorded were plaque index,gingival index, bleeding index, probing PD, and clinical attachment levels and scoring was done on 6 surfaces of all teeth. For the CRP assessment, blood samples were collected from subjects at the time of clinical examination. Analysis of covariance was used for comparison of mean values between the groups to adjust the ages (P value chronic periodontitis compared with controls. This was found to be statistically significant. A statistically significant difference (P = 0.012) was found in the CRP level between groups I and II and between groups II and III, and between groups I and III. Conclusion: The results of the present study indicated an increase in serum CRP levels in subjects with generalized aggressive periodontitis and chronic periodontitis as compared with the controls. PMID:23087729

Evaluation of serum C-reactive protein levels in subjects with aggressive and chronic periodontitis and comparison with healthy controls.

Science.gov (United States)

Kanaparthy, Aruna; Kanaparthy, Rosaiah; Niranjan, Nandini

2012-05-01

Periodontal subgingival pathogens affect local and systemic immune responses and initiate an acute phase systemic inflammatory response characterized by the release of C-reactive proteins (CRPs). This study has been carried out to evaluate the serum concentration of CRPs, which can be used as a marker of periodontal disease as well as a risk indicator for cardiovascular diseases. In a retrospective study a total number of 45 subjects were selected from the outpatient department of periodontics a mean age of 40 years. Based on the periodontal status, the subjects were divided into 3 groups of 15 subjects each. Group I: Control group [with attachment loss (AL) ≤ 2 mm and pocket depth (PD) periodontitis (AL ≤ 5 mm), Group III: chronic periodontitis (AL ≥ 2 mm, PD ≥ 5 mm), which includes moderate and severe periodontitis. The clinical parameters recorded were plaque index,gingival index, bleeding index, probing PD, and clinical attachment levels and scoring was done on 6 surfaces of all teeth. For the CRP assessment, blood samples were collected from subjects at the time of clinical examination. Analysis of covariance was used for comparison of mean values between the groups to adjust the ages (P value periodontitis compared with controls. This was found to be statistically significant. A statistically significant difference (P = 0.012) was found in the CRP level between groups I and II and between groups II and III, and between groups I and III. The results of the present study indicated an increase in serum CRP levels in subjects with generalized aggressive periodontitis and chronic periodontitis as compared with the controls.

Episodic retrieval involves early and sustained effects of reactivating information from encoding.

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Johnson, Jeffrey D; Price, Mason H; Leiker, Emily K

2015-02-01

Several fMRI studies have shown a correspondence between the brain regions activated during encoding and retrieval, consistent with the view that memory retrieval involves hippocampally-mediated reinstatement of cortical activity. With the limited temporal resolution of fMRI, the precise timing of such reactivation is unclear, calling into question the functional significance of these effects. Whereas reactivation influencing retrieval should emerge with neural correlates of retrieval success, that signifying post-retrieval monitoring would trail retrieval. The present study employed EEG to provide a temporal landmark of retrieval success from which we could investigate the sub-trial time course of reactivation. Pattern-classification analyses revealed that early-onsetting reactivation differentiated the outcome of recognition-memory judgments and was associated with individual differences in behavioral accuracy, while reactivation was also evident in a sustained form later in the trial. The EEG findings suggest that, whereas prior fMRI findings could be interpreted as reflecting the contribution of reinstatement to retrieval success, they could also indicate the maintenance of episodic information in service of post-retrieval evaluation. Copyright © 2014 Elsevier Inc. All rights reserved.

Oxime reactivators and their in vivo and in vitro effects on nicotinic receptors

Czech Academy of Sciences Publication Activity Database

Soukup, O.; Krůšek, Jan; Kaniaková, Martina; Kumar, U. K.; Oz, M.; Jun, D.; Fusek, J.; Kuča, K.; Tobin, G.

2011-01-01

Roč. 60, č. 4 (2011), s. 679-686 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA202/09/0806; GA MŠk(CZ) LC554 Grant - others:GA ČR(CZ) GAP303/11/1907 Institutional research plan: CEZ:AV0Z50110509 Keywords : organophosphates * patch-clamp * nicotinic receptors * reactivator * isometric muscle contraction * TE671 cells Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.555, year: 2011

Effective neutron temperature measurements in well moderated reactor by the reactivity coefficient method

International Nuclear Information System (INIS)

Raisic, N.; Klinc, T.

1968-11-01

The ratio of the reactivity changes of a nuclear reactor produced by successive introduction of two different neutron absorbers in the reactor core, has been measured and information on effective neutron temperature at a particular point obtained. Boron was used as a l/v absorber and cadmium as an absorber sensiti ve to neutron temperature. Effective neutron temperature distribution has been deduced by moving absorbers across the reactor core and observing the corresponding reactivity changes. (author)

Impact of aerobic exercise intensity on craving and reactivity to smoking cues.

Science.gov (United States)

Janse Van Rensburg, Kate; Elibero, Andrea; Kilpatrick, Marcus; Drobes, David J

2013-06-01

Aerobic exercise can acutely reduce cigarette cravings during periods of nicotine deprivation. The primary aim of this study was to assess the differential effects of light and vigorous intensity aerobic exercise on cigarette cravings, subjective and physiological reactivity to smoking cues, and affect after overnight nicotine deprivation. A secondary aim was to examine cortisol change as a mediator of the effects of exercise on smoking motivation. 162 (55 female, 107 male) overnight nicotine-deprived smokers were randomized to one of three exercise conditions: light intensity, vigorous intensity, or a passive control condition. After each condition, participants engaged in a standardized cue reactivity assessment. Self-reported urges to smoke, affect, and salivary cortisol were assessed at baseline (i.e., before each condition), immediately after each condition, and after the cue reactivity assessment. Light and vigorous exercise significantly decreased urges to smoke and increased positive affect, relative to the control condition. In addition, those in the vigorous exercise condition demonstrated suppressed appetitive reactivity to smoking cues, as indexed by the startle eyeblink reflex. Although exercise intensity was associated with expected changes in cortisol concentration, these effects were not related to changes in craving or cue reactivity. Both light and vigorous exercise can reduce general cravings to smoke, whereas vigorous exercise appears especially well-suited for reducing appetitive reactions to cues that may precede smoking. Results did not support exercise-induced cortisol release as a mechanism for these effects. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Short-term effects of an anti-inflammatory treatment on clinical parameters and serum levels of C-reactive protein and proinflammatory cytokines in subjects with periodontitis.

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Renvert, Stefan; Lindahl, Christel; Roos-Jansåker, Ann-Marie; Lessem, Jan

2009-06-01

Periodontal disease is the most common multifactorial disease, afflicting a very large proportion of the adult population. Periodontal disease secondarily causes increases in the serum levels of C-reactive protein (CRP) and other markers of inflammation. An increased level of CRP reflects an increased risk for cardiovascular disease. The aim of the current randomized clinical trial was to evaluate the short-term effect of a combination of dipyridamole and prednisolone (CRx-102) on the levels of high-sensitivity (hs)-CRP, proinflammatory markers in blood, and clinical signs of periodontal disease. Fifty-seven patients with >/=10 pockets with probing depths >/=5 mm were randomized into two groups in this masked single-center placebo-controlled study: CRx-102 (n = 28) and placebo (n = 29). hs-CRP levels, inflammatory markers (interleukin [IL]-6, -1beta, -8, and -12, tumor necrosis factor-alpha, and interferon-gamma [IFN-gamma]), bleeding on probing (BOP), and changes in probing depths were evaluated. The subjects received mechanical non-surgical therapy after 42 days, and the study was completed after 49 days. At day 42, the differences in the hs-CRP, IFN-gamma, and IL-6 levels between the two groups were statistically significant (P <0.05), whereas no difference was found for the other inflammatory markers. There was no change in probing depth or BOP between the two groups. The administration of CRx-102 resulted in significant decreases in hs-CRP, IFN-gamma, and IL-6, but it did not significantly change BOP or probing depths.

Mediating effect of Facebook addiction on the relationship between subjective vitality and subjective happiness.

Science.gov (United States)

Uysal, Recep; Satici, Seydi Ahmet; Akin, Ahmet

2013-12-01

This study examined the mediating effects of Facebook addiction on the relationship between subjective vitality and subjective happiness. 297 university students (157 women, 140 men; M age = 20.1 yr., SD = 1.3) were administered the Facebook Addiction Scale, the Subjective Vitality Scale, and the Subjective Happiness Scale. Hierarchical regression analysis showed that Facebook addiction partially mediated the relationship between subjective vitality and subjective happiness.

Oxytocin increases amygdala reactivity to threatening scenes in females.

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Lischke, Alexander; Gamer, Matthias; Berger, Christoph; Grossmann, Annette; Hauenstein, Karlheinz; Heinrichs, Markus; Herpertz, Sabine C; Domes, Gregor

2012-09-01

The neuropeptide oxytocin (OT) is well known for its profound effects on social behavior, which appear to be mediated by an OT-dependent modulation of amygdala activity in the context of social stimuli. In humans, OT decreases amygdala reactivity to threatening faces in males, but enhances amygdala reactivity to similar faces in females, suggesting sex-specific differences in OT-dependent threat-processing. To further explore whether OT generally enhances amygdala-dependent threat-processing in females, we used functional magnetic resonance imaging (fMRI) in a randomized within-subject crossover design to measure amygdala activity in response to threatening and non-threatening scenes in 14 females following intranasal administration of OT or placebo. Participants' eye movements were recorded to investigate whether an OT-dependent modulation of amygdala activity is accompanied by enhanced exploration of salient scene features. Although OT had no effect on participants' gazing behavior, it increased amygdala reactivity to scenes depicting social and non-social threat. In females, OT may, thus, enhance the detection of threatening stimuli in the environment, potentially by interacting with gonadal steroids, such as progesterone and estrogen. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effect of periodontal treatment on C-reactive protein: A clinical study.

Science.gov (United States)

Kumar, Santosh; Shah, Samir; Budhiraja, Shilpa; Desai, Khushboo; Shah, Chirag; Mehta, Dhaval

2013-07-01

Chronic periodontitis in amultifactorial inflammatory disease which is caused by various microorganisms. Many studies have found close association between chronic periodontitis and C-reactive protein (CRP). CRPis an inflammatory marker which increases in all inflammatory condition. The present clinical study was designed to show the effect of periodontal treatment on the CRP levels of gingival crevicular fluid and to determine the effect of nonsurgical therapy in minimizing the CRP levels in chronic generalized periodontitis. Gingival crevicular fluid was collected using a micro capillary pipette that was hand calibrated at every 1 mm till 10 mm, from selected sites in the subjects on the 1st, 14th and 45th days. Decreased CRP levels of gingival crevicular fluid were observed at the end of the study. There was a 37% reduction in probing pocket depth and 45% gain in clinical attachment level and a reduction of about 57% after 14 days and 90% reduction of CRP levels in gingival crevicular fluid after 45 days. Thus, the results show that the presence of CRP level is more significant in gingival crevicular fluid and confirms the underlying inflammatory component of the disease activity in chronic periodontitis.

Radiation enhanced reactivation of herpes simplex virus: effect of caffeine.

Science.gov (United States)

Hellman, K B; Lytle, C D; Bockstahler, L E

1976-09-01

Ultaviolet enhanced (Weigle) reactivation of UV-irradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cell monolayers was decreased by caffeine. X-ray enhanced reactivation of UV-irradiated virus in X-irradiated monolayers (X-ray reactivation) and UV- or X-ray-inactivated capacity of the cells to support unirradiated virus plaque formation were unaffected by caffeine. The results suggest that a caffeine-sensitive process is necessary for the expression of Weigle reactivation for herpes virus. Since cafeine did not significantly affect X-ray reactivation, different mechanisms may be responsible for the expression of Weigle reactivation and X-ray reactivation.

Radiation enhaced reactivation of herpes simplex virus: effect of caffeine

International Nuclear Information System (INIS)

Hellman, K.B.; Lytle, C.D.; Bockstahler, L.E.

1976-01-01

Ultraviolet enhanced (Weigle) reactivation of UV-irradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cell monolayers was decreased by caffeine. X-ray enhanced reactivation of UV-irradiated virus in X-irradiated monolayers (X-ray reactivation) and UV- or X-ray-inactivated capacity of the cells to support unirradiated virus plaque formation were unaffected by caffeine. The results suggest that a caffeine-sensitive process is necessary for the expression of Weigle reactivation for herpes virus. Since caffeine did not significantly affect X-ray reactivation, different mechanisms may be responsible for the expression of Weigle reactivation and X-ray reactivation

Differential Immuno-Reactivity to Genomic DNA, RNA and Mitochondrial DNA is Associated with Auto-Immunity

Directory of Open Access Journals (Sweden)

Vilena V. Ivanova

2014-12-01

Full Text Available Background: Circulating auto-reactive antibodies are hallmark features of auto-immune diseases, however little is known with respect to the specificity of such bio-markers. In the present study, we investigated the specificity of anti-nucleic acid antibodies in the blood of subjects with systemic lupus erythematosus (SLE and healthy controls. Methods: Sera from 12 SLE cases and 8 controls were evaluated for immuno-reactivity to purified RNA, DNA and mitochondrial DNA (mtDNA by enzyme-linked immuno-sorbent assay (ELISA. Results: As expected, immuno-reactivity to total nucleic acids was significantly higher in subjects with SLE when compared to healthy controls, however a clear distinction was observed among the various nucleic acid sub-types, with sera from SLE subjects displaying the greatest immuno-reactivity to RNA followed by mtDNA and then total DNA. Conclusion: The identification of auto-reactive antibodies can serve as highly sensitive biomarkers, although their specificity may not always allow diagnostic certainty. The knowledge that auto-antibodies in subjects with SLE display differential immuno-reactivity may help to improve existing diagnostics and may lead to a better understanding of the pathogenesis of auto-immune disorders.

Long-Term Effectiveness of Stress Management at Work: Effects of the Changes in Perceived Stress Reactivity on Mental Health and Sleep Problems Seven Years Later.

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Herr, Raphael M; Barrech, Amira; Riedel, Natalie; Gündel, Harald; Angerer, Peter; Li, Jian

2018-02-03

The reduction of stress reactivity resulting from stress management interventions prevents disorders and improves mental health, however, its long-term sustainability has been little examined. The objective of this study was, therefore, to determine the effectiveness of a stress management intervention, designed to improve stress reactivity, for mental health and sleep problems seven years later, using longitudinal data from 101 male industrial workers. Linear regressions estimated the adjusted effects of the changes in stress reactivity in general as well as in its six subdimensions (work overload, social conflict, social stress, failure at work, and anticipatory and prolonged reactivity) on depression, anxiety, and sleep problems seven years later. The improvement of the prolonged reactivity had positive effects on depression, anxiety, and sleep problems (unstandardized regression coefficients [ Bs ] ≥ 0.35, all p -values ≤ 0.01). Depression and sleep problems were further improved by a reduction of the reactivity to social conflicts ( Bs ≥ 0.29, p -values stress reactivity resulting from a work stress intervention was effective and generally long-lasting in preventing mental health and sleep problems. The reduction of the prolonged reactivity seems of particular importance and efficient in inhibiting negative stress manifestations.

Structural and reactivity models for copper oxygenases: cooperative effects and novel reactivities.

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Serrano-Plana, Joan; Garcia-Bosch, Isaac; Company, Anna; Costas, Miquel

2015-08-18

Dioxygen is widely used in nature as oxidant. Nature itself has served as inspiration to use O2 in chemical synthesis. However, the use of dioxygen as an oxidant is not straightforward. Its triplet ground-state electronic structure makes it unreactive toward most organic substrates. In natural systems, metalloenzymes activate O2 by reducing it to more reactive peroxide (O2(2-)) or superoxide (O2(-)) forms. Over the years, the development of model systems containing transition metals has become a convenient tool for unravelling O2-activation mechanistic aspects and reproducing the oxidative activity of enzymes. Several copper-based systems have been developed within this area. Tyrosinase is a copper-based O2-activating enzyme, whose structure and reactivity have been widely studied, and that serves as a paradigm for O2 activation at a dimetal site. It contains a dicopper center in its active site, and it catalyzes the regioselective ortho-hydroxylation of phenols to catechols and further oxidation to quinones. This represents an important step in melanin biosynthesis and it is mediated by a dicopper(II) side-on peroxo intermediate species. In the present accounts, our research in the field of copper models for oxygen activation is collected. We have developed m-xylyl linked dicopper systems that mimick structural and reactivity aspects of tyrosinase. Synergistic cooperation of the two copper(I) centers results in O2 binding and formation of bis(μ-oxo)dicopper(III) cores. These in turn bind and ortho-hydroxylate phenolates via an electrophilic attack of the oxo ligand over the arene. Interestingly the bis(μ-oxo)dicopper(III) cores can also engage in ortho-hydroxylation-defluorination of deprotonated 2-fluorophenols, substrates that are well-known enzyme inhibitors. Analysis of Cu2O2 species with different binding modes show that only the bis(μ-oxo)dicopper(III) cores can mediate the reaction. Finally, the use of unsymmetric systems for oxygen activation is a field

Effect of Marine-Derived n-3 Polyunsaturated Fatty Acids on C-Reactive Protein, Interleukin 6 and Tumor Necrosis Factor α: A Meta-Analysis

Science.gov (United States)

Li, Kelei; Huang, Tao; Zheng, Jusheng; Wu, Kejian; Li, Duo

2014-01-01

Background Previous studies did not draw a consistent conclusion about the effects of marine-derived n-3 polyunsaturated fatty acids (PUFAs) on fasting blood level of C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α). Methods and Findings A comprehensive search of Web of Science, PubMed, Embase and Medline (from 1950 to 2013) and bibliographies of relevant articles was undertaken. Sixty-eight RCTs with a total of 4601 subjects were included in the meta-analysis. Marine-derived n-3 PUFAs supplementation showed a lowering effect on Marine-derived n-3 PUFAs supplementation had a significant lowering effect on TNF-α, IL-6 and CRP in three groups of subjects (subjects with chronic non-autoimmune disease, subjects with chronic autoimmune disease and healthy subjects). A significant negative linear relationship between duration and effect size of marine-derived n-3 PUFAs supplementation on fasting blood levels of TNF-α and IL-6 in subjects with chronic non-autoimmune disease was observed, indicating that longer duration of supplementation could lead to a greater lowering effect. A similar linear relationship was also observed for IL-6 levels in healthy subjects. Restricted cubic spline analysis and subgroup analysis showed that the lowering effect of marine-derived n-3 PUFAs on CRP, IL-6 and TNF-α in subjects with chronic non-autoimmune disease became weakened when body mass index was greater than 30 kg/m2. The effect of marine-derived n-3 PUFAs from dietary intake was only assessed in subjects with chronic non-autoimmune disease, and a significant lowering effect was observed on IL-6, but not on CRP and TNF-α. Conclusions Marine-derived n-3 PUFAs supplementation had a significant lowering effect on CRP, IL-6 and TNF-α level. The lowering effect was most effective in non-obese subjects and consecutive long-term supplementation was recommended. PMID:24505395

Preliminary investigation of actinide and xenon reactivity effects in accelerator transmutation of waste high-flux systems

International Nuclear Information System (INIS)

Olson, K.R.; Henderson, D.L.

1995-01-01

The possibility of an unstable positive reactivity growth in an accelerator transmutation of waste (ATW)-type high-flux system is investigated. While it has always been clear that xenon is an important actor in the reactivity response of a system to flux changes, it has been suggested that in very high thermal flux transuranic burning systems, a positive, unstable reactivity growth could be caused by the actinides alone. Initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately. The maximum change in reactivity after a flux change caused by the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or startup. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response caused by the actinides. The capabilities and applications of both the current actinide model and the xenon model are discussed. Finally, the need for a complete dynamic model for the high-flux fluid-fueled ATW system is addressed

An earlier time of scan is associated with greater threat-related amygdala reactivity.

Science.gov (United States)

Baranger, David A A; Margolis, Seth; Hariri, Ahmad R; Bogdan, Ryan

2017-08-01

Time-dependent variability in mood and anxiety suggest that related neural phenotypes, such as threat-related amygdala reactivity, may also follow a diurnal pattern. Here, using data from 1,043 young adult volunteers, we found that threat-related amygdala reactivity was negatively coupled with time of day, an effect which was stronger in the left hemisphere (β = -0.1083, p-fdr = 0.0012). This effect was moderated by subjective sleep quality (β = -0.0715, p-fdr = 0.0387); participants who reported average and poor sleep quality had relatively increased left amygdala reactivity in the morning. Bootstrapped simulations suggest that similar cross-sectional samples with at least 300 participants would be able to detect associations between amygdala reactivity and time of scan. In control analyses, we found no associations between time and V1 activation. Our results provide initial evidence that threat-related amygdala reactivity may vary diurnally, and that this effect is potentiated among individuals with average to low sleep quality. More broadly, our results suggest that considering time of scan in study design or modeling time of scan in analyses, as well as collecting additional measures of circadian variation, may be useful for understanding threat-related neural phenotypes and their associations with behavior, such as fear conditioning, mood and anxiety symptoms, and related phenotypes. © The Author (2017). Published by Oxford University Press.

The role of age on reactivity and memory for emotional pictures.

Science.gov (United States)

Christianson, S A; Fällman, L

1990-01-01

The purpose of this study was to investigate subjects' reactivity to emotional pictures and their recollection of these pictures, and to examine these two factors as they relate to age. Adolescents and young adults were shown emotionally arousing scenic pictures for long (4-s) and very brief (50-ms) durations. Recognition of the pictures and recall and recognition of words presented along with the pictures were assessed both immediately after the presentation and six weeks later. The results showed that very negative pictures are retained better than neutral or even positive pictures, and that very negative pictures reduce memory for associated information. It was also found that adolescents show a somewhat lower reactivity to very negative pictures and a higher degree of retention of these pictures than adults. The results are discussed in relation to (a) habituation effects, (b) strategies that subjects might develop to block emotional involvement, and (c) the notion that watching violence might serve as a powerful prime to socially undesirable behaviour.

Identification of fast power reactivity effect in nuclear power reactor

International Nuclear Information System (INIS)

Efanov, A.I.; Kaminskas, V.A.; Lavrukhin, V.S.; Rimidis, A.P.; Yanitskene, D.Yu.

1987-01-01

A nuclear power reactor is an object of control with distributed parameters, characteristics of which vary during operation time. At the same time the reactor as the object of control has internal feedback circuits, which are formed as a result of the effects of fuel parameters and a coolant (pressure, temperature, steam content) on the reactor breeding properties. The problem of internal feedback circuit identification in a nuclear power reactor is considered. Conditions for a point reactor identification are obtained and algorithms of parametric identification are constructed. Examples of identification of fast power reactivity effect for the RBMK-1000 reactor are given. Results of experimental testing have shown that the developed method of fast power reactivity effect identification permits according to the data of normal operation to construct adaptive models for the point nuclear reactor, designed for its behaviour prediction in stationary and transition operational conditions. Therefore, the models considered can be used for creating control systems of nuclear power reactor thermal capacity (of RBMK type reactor, in particular) which can be adapted to the change in the internal feedback circuit characteristics

Effect of tamoxifen on the coronary vascular reactivity of spontaneously hypertensive female rats

Directory of Open Access Journals (Sweden)

M.V. Borgo

2011-08-01

Full Text Available Tamoxifen has been associated with a reduction in the incidence of myocardial infarction. However, the effects of tamoxifen on coronary reactivity have not been fully elucidated. The objective of this study was to determine the effects of chronic treatment with tamoxifen on coronary vascular reactivity in spontaneously hypertensive rats (SHR. Female SHR were divided into four groups (N = 7 each: sham-operated (SHAM, sham-operated and treated with tamoxifen (10 mg/kg by gavage for 90 days (TAMOX, ovariectomized (OVX, and ovariectomized and treated with tamoxifen (OVX+TAMOX. Mean arterial pressure (MAP, heart rate (HR, coronary perfusion pressure (CPP, and coronary vascular reactivity were measured. MAP and HR were reduced (9.42 and 11.67%, respectively in the OVX+TAMOX group compared to the OVX group (P < 0.01. The coronary vascular reactivity of the OVX+TAMOX group presented smaller vasoconstrictor responses to acetylcholine (2-64 µg when compared to the OVX group (P < 0.01 and this response was similar to that of the SHAM group. The adenosine-induced vasodilator response was greater in the TAMOX group compared to the SHAM and OVX groups (P < 0.05. Baseline CPP was higher in OVX+TAMOX and TAMOX groups (136 ± 3.6 and 130 ± 1.5 mmHg than in OVX and SHAM groups (96 ± 2 and 119 ± 2.3 mmHg; P < 0.01. Tamoxifen, when combined with OVX, attenuated the vasoconstriction induced by acetylcholine and increased the adenosine-induced vasodilatory response, as well as reducing the MAP, suggesting beneficial effects of tamoxifen therapy on coronary vascular reactivity after menopause.

Microheterogeneity of alpha 1-acid glycoprotein in healthy elderly subjects: patterns obtained by crossed affino-immunoelectrophoresis.

Science.gov (United States)

Kawerk, N; Succari-Aderschlag, M; Foglietti, M J

1991-10-14

Total serum alpha 1-acid glycoprotein (AGP) concentration and concanavalin A-dependent microheterogeneity were studied in 31 healthy elderly subjects (18 men, 13 women, 71 to 76 yr old). Crossed affino-immunoelectrophoresis (CAIE) revealed three microheterogeneity variants of AGP: non-reactive, weakly reactive and strongly reactive with ConA. Two patterns were found in both elderly men and women, i.e. a normal pattern and one with an increase in the non-reactive form. Mean serum AGP levels in the elderly subjects with slightly higher than in a reference group of younger subjects. The Con A non-reactive form of AGP was increased in 42% of the elderly population. An increase in the non-reactive form of AGP in CAIE should be considered as general expression of chronic inflammation which is of no clinical relevance.

Effects of worry on physiological and subjective reactivity to emotional stimuli in generalized anxiety disorder and nonanxious control participants.

Science.gov (United States)

Llera, Sandra J; Newman, Michelle G

2010-10-01

The present study examined the effect of worry versus relaxation and neutral thought activity on both physiological and subjective responding to positive and negative emotional stimuli. Thirty-eight participants with generalized anxiety disorder (GAD) and 35 nonanxious control participants were randomly assigned to engage in worry, relaxation, or neutral inductions prior to sequential exposure to each of four emotion-inducing film clips. The clips were designed to elicit fear, sadness, happiness, and calm emotions. Self reported negative and positive affect was assessed following each induction and exposure, and vagal activity was measured throughout. Results indicate that worry (vs. relaxation) led to reduced vagal tone for the GAD group, as well as higher negative affect levels for both groups. Additionally, prior worry resulted in less physiological and subjective responding to the fearful film clip, and reduced negative affect in response to the sad clip. This suggests that worry may facilitate avoidance of processing negative emotions by way of preventing a negative emotional contrast. Implications for the role of worry in emotion avoidance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Craving by imagery cue reactivity in opiate dependence following detoxification

OpenAIRE

Behera, Debakanta; Goswami, Utpal; Khastgir, Udayan; Kumar, Satindra

2003-01-01

Background: Frequent relapses in opioid addiction may be a result of abstinentemergent craving. Exposure to various stimuli associated with drug use (drug cues) may trigger craving as a conditioned response to ?drug cues?. Aims: The present study explored the effects of imagery cue exposure on psychophysiological mechanisms of craving, viz. autonomic arousal, in detoxified opiate addicts. Methodology: Opiate dependent subjects (N=38) following detoxification underwent imagery cue reactivity t...

Study of catalytic effects of mineral matter level on coal reactivity

Energy Technology Data Exchange (ETDEWEB)

Mazzocco, Nestor J.; Klunder, Edgar B.; Krastman, Donald

1981-03-01

Coal liquefaction experiments using a 400-lb/day bubble-column reactor tested the catalytic effects of added mineral matter level on coal conversion, desulfurization, and distillate yields in continuous operation under recycle conditions, with specific emphasis on the use of a disposable pyrite catalyst indigenous to the feed coal. Western Kentucky No. 11 run-of-mine (ROM) and washed coals were used as feedstocks to determine the effects of levels of mineral matter, specifically iron compounds. Liquefaction reactivity as characterized by total distillate yield was lower for washed coal, which contained less mineral matter. Liquefaction reactivity was regained when pyrite concentrate was added as a disposable catalyst to the washed coal feed in sufficient quantity to match the feed iron concentration of the run-of-mine coal liquefaction test run.

Heat shock and herpes virus: enhanced reactivation without untargeted mutagenesis

International Nuclear Information System (INIS)

Lytle, C.D.; Carney, P.G.

1988-01-01

Enhanced reactivation of Ultraviolet-irradiated virus has been reported to occur in heat-shocked host cells. Since enhanced virus reactivation is often accompanied by untargeted mutagenesis, we investigated whether such mutagenesis would occur for herpes simplex virus (HSV) in CV-1 monkey kidney cells subjected to heat shock. In addition to expressing enhanced reactivation, the treated cells were transiently more susceptible to infection by unirradiated HSV. No mutagenesis of unirradiated HSV was found whether infection occurred at the time of increased susceptibility to infection or during expression of enhanced viral reactivation

Determination of static and dynamic reactivity effects in KNK II

International Nuclear Information System (INIS)

Essig, C.

1987-11-01

In the frame of a pre-study of the KNK II test program two series of experiments related to inherent safety characteristics of sodium cooled breeder reactors have been elaborated, which are one basis for the performance of experiments of the Loss Of Flow (LOF) type and the Loss Of Heat Sink (LOHS) type. Tests of this type at KNK II would -different from the earlier tests at RAPSODIE and EBR-II- provide a demonstration of the inherently safe performance in case of a significantly non-zero Doppler effect. With a suitable execution, the foreseen series of experiments allow, as explained in this report, a substantial separation of the reactivity contributions and the determination of reactivity effects, i.e. the time constants of the recouplings. The performance and evaluation of these experiments with respect to the inherent safety potential will once more underline the distinguished role of KNK II for the development of fast breeders [de

A technique for computing bowing reactivity feedback in LMFBR's

International Nuclear Information System (INIS)

Finck, P.J.

1987-01-01

During normal or accidental transients occurring in a LMFBR core, the assemblies and their support structure are subjected to important thermal gradients which induce differential thermal expansions of the walls of the hexcans and differential displacement of the assembly support structure. These displacements, combined with the creep and swelling of structural materials, remain quite small, but the resulting reactivity changes constitute a significant component of the reactivity feedback coefficients used in safety analyses. It would be prohibitive to compute the reactivity changes due to all transients. Thus, the usual practice is to generate reactivity gradient tables. The purpose of the work presented here is twofold: develop and validate an efficient and accurate scheme for computing these reactivity tables; and to qualify this scheme

EFFECT OF REACTIVE MAGNESIUM OXIDE ON PROPERTIES OF ALKALI ACTIVATED SLAG GEOPOLYMER CEMENT PASTES

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H. A. Abdel-Gawwad

2015-03-01

Full Text Available The effect of different proportions and different reactivities of MgO on the drying shrinkage and compressive strength of alkali activated slag pastes (AAS has been investigated. The slag was activated by 6 wt.% sodium hydroxide and liquid sodium silicate at ratio of 3:3 (wt.. The different reactivities of MgOs were produced from the calcination of hydromagnesite at different temperatures (550, 1000, 1250 C. The results showed that the reactivity of magnesium oxide decreases with increasing the calcination temperature. Also, the drying shrinkage of AAS was reduced by the replacement of slag with MgOs. The highly reactive MgO accelerated the hydration of AAS at early ages. The replacement of slag with 5% MgO550 increased one day compressive strength by ~26 % while MgO1250 had little effect. A significant increase in strength was observed after 7 days in case of replacement of slag with 5 % MgO1250. The MgO reacts with slag to form hydrotalcite likephases (Ht as detected by XRD, FTIR spectroscopy, TGA/DTG analysis and SEM.

Self-Reported Trait Mindfulness and Affective Reactivity: A Motivational Approach Using Multiple Psychophysiological Measures

Science.gov (United States)

Cosme, Danielle; Wiens, Stefan

2015-01-01

As a form of attention, mindfulness is qualitatively receptive and non-reactive, and is thought to facilitate adaptive emotional responding. One suggested mechanism is that mindfulness facilitates disengagement from an affective stimulus and thereby decreases affective reactivity. However, mindfulness has been conceptualized as a state, intervention, and trait. Because evidence is mixed as to whether self-reported trait mindfulness decreases affective reactivity, we used a multi-method approach to study the relationship between individual differences in self-reported trait mindfulness and electrocortical, electrodermal, electromyographic, and self-reported responses to emotional pictures. Specifically, while participants (N = 51) passively viewed pleasant, neutral, and unpleasant IAPS pictures, we recorded high-density (128 channels) electrocortical, electrodermal, and electromyographic data to the pictures as well as to acoustic startle probes presented during the pictures. Afterwards, participants rated their subjective valence and arousal while viewing the pictures again. If trait mindfulness spontaneously reduces general emotional reactivity, then for individuals reporting high rather than low mindfulness, response differences between emotional and neutral pictures would show relatively decreased early posterior negativity (EPN) and late positive potential (LPP) amplitudes, decreased skin conductance responses, and decreased subjective ratings for valence and arousal. High mindfulness would also be associated with decreased emotional modulation of startle eyeblink and P3 amplitudes. Although results showed clear effects of emotion on the dependent measures, in general, mindfulness did not moderate these effects. For most measures, effect sizes were small with rather narrow confidence intervals. These data do not support the hypothesis that individual differences in self-reported trait mindfulness are related to spontaneous emotional responses during picture

Self-reported trait mindfulness and affective reactivity: a motivational approach using multiple psychophysiological measures.

Directory of Open Access Journals (Sweden)

Danielle Cosme

Full Text Available As a form of attention, mindfulness is qualitatively receptive and non-reactive, and is thought to facilitate adaptive emotional responding. One suggested mechanism is that mindfulness facilitates disengagement from an affective stimulus and thereby decreases affective reactivity. However, mindfulness has been conceptualized as a state, intervention, and trait. Because evidence is mixed as to whether self-reported trait mindfulness decreases affective reactivity, we used a multi-method approach to study the relationship between individual differences in self-reported trait mindfulness and electrocortical, electrodermal, electromyographic, and self-reported responses to emotional pictures. Specifically, while participants (N = 51 passively viewed pleasant, neutral, and unpleasant IAPS pictures, we recorded high-density (128 channels electrocortical, electrodermal, and electromyographic data to the pictures as well as to acoustic startle probes presented during the pictures. Afterwards, participants rated their subjective valence and arousal while viewing the pictures again. If trait mindfulness spontaneously reduces general emotional reactivity, then for individuals reporting high rather than low mindfulness, response differences between emotional and neutral pictures would show relatively decreased early posterior negativity (EPN and late positive potential (LPP amplitudes, decreased skin conductance responses, and decreased subjective ratings for valence and arousal. High mindfulness would also be associated with decreased emotional modulation of startle eyeblink and P3 amplitudes. Although results showed clear effects of emotion on the dependent measures, in general, mindfulness did not moderate these effects. For most measures, effect sizes were small with rather narrow confidence intervals. These data do not support the hypothesis that individual differences in self-reported trait mindfulness are related to spontaneous emotional responses

Relational victimization and proactive versus reactive relational aggression: The moderating effects of respiratory sinus arrhythmia and skin conductance.

Science.gov (United States)

Wagner, Caitlin R; Abaied, Jamie L

2015-01-01

This research examined the moderating effect of the autonomic nervous system (ANS) on the associations between relational victimization and reactive and proactive relational aggression. Both branches of the ANS, the parasympathetic nervous system (indexed by respiratory sinus arrhythmia reactivity; RSA-Reactivity) and the sympathetic nervous system (indexed by skin conductance level reactivity; SCL-Reactivity), were examined. Emerging adults (N = 168) self-reported on relational victimization and proactive and reactive relational aggression; RSA-Reactivity and SCL-Reactivity were assessed in response to a laboratory stressor. Relational victimization predicted heightened reactive relational aggression given RSA augmentation/high SCL-Reactivity (i.e., coactivation) and RSA withdrawal/low SCL-Reactivity (i.e., coinhibition). In addition, relational victimization predicted heightened reactive relational aggression given RSA augmentation/low SCL-Reactivity (i.e., reciprocal parasympathetic activation). This study extends previous research on relational victimization and provides novel evidence that (a) exposure to relational victimization is associated with reactive relational aggression, but not proactive relational aggression, and (b) parasympathetic and sympathetic nervous system reactivity jointly moderate the link between relational victimization and reactive relational aggression. © 2015 Wiley Periodicals, Inc.

The effect of reactive emotions expressed in response to another's anger on inferences of social power.

Science.gov (United States)

Hareli, Shlomo; David, Shlomo

2017-06-01

Social perception of emotions is influenced by the context in which it occurs. One such context is a social interaction involving an exchange of emotions. The way parties to the interaction are perceived is shaped by the combination of emotions exchanged. This idea was examined by assessing the extent to which expressions of anger toward a target-which, in isolation, are perceived as signals of high social power-are influenced by the target's emotional reaction to it (i.e., reactive emotions). Three studies show that the angry person was perceived as having a higher level of social power when this anger was responded by fear or sadness than when it was responded by neutrality or anger. Study 1 indicated that reactive emotions have a stronger effect on perceived social power when emotions were incongruent with gender stereotypes. Study 2 indicated that these effects are a result of these emotions serving as reactive emotions rather than a benchmark against which the angry person's power is assessed. Study 3 showed that reactive emotions affect perceived social power by serving as signals of the level to which the high social power suggested by the first person's expression is confirmed by its target. Comparing effects of reactive emotions to anger with reactive emotions to sadness, showed that perceived social power of the expresser is determined by the nature of the expression, with some adjustment caused by the reactive emotions. This underscores the importance of social interaction as a context for the social perception of emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Studies of the Reactivity Effect of Polythene in the Fast Reactor FR0

Energy Technology Data Exchange (ETDEWEB)

Tiren, I; Haakansson, R

1967-12-15

Measurements of the reactivity effect of polythene (CH{sub 2}){sub n} have been made in two FR0 assemblies having neutron spectra broadly similar to those of current steam cooled fast reactor concepts. The experiments include studies of the axial and radial distributions of the reactivity coefficient. The reactivity contributions from small polythene samples were found to be approximately additive. No large effects of heterogeneity or interaction between samples were observed. Comparisons with calculations using a homogeneous model are therefore relevant. The experimental results are largely in reasonable agreement with calculated values. The latter are very sensitive to moderate changes in the cross sections at low neutron energies. The agreement with experiment is improved if transport rather than diffusion theory is used. Although the geometrical size of FR0 is probably adequate for studies of steam coefficients in fast power reactors, Pu isotopes and fission products should be included in the core composition in order to obtain information of direct use in such studies.

Maternal Brain-Reactive Antibodies and Autism Spectrum Disorder

Science.gov (United States)

2015-10-01

AWARD NUMBER: W81XWH-14-1-0369 TITLE: Maternal Brain-Reactive Antibodies and Autism Spectrum Disorder PRINCIPAL INVESTIGATOR: Betty Diamond...Sep 2015 4. TITLE AND SUBTITLE Maternal Brain-Reactive Antibodies and Autism Spectrum 5a. CONTRACT NUMBER Disorder 5b. GRANT NUMBER W81XWH-14-1...to approximately 5% of cases of ASD. 15. SUBJECT TERMS Fetal brain; Autism spectrum disorder ; antibody; B cells; Caspr2 16. SECURITY CLASSIFICATION

Lactation and Reactivity to Physical and Psychological Stress

National Research Council Canada - National Science Library

Carter, C

1998-01-01

.... Studies of basal cortisol levels, cognitive performance and reactivity to stressors were conducted in human subjects during late pregnancy and immediately postpartum in women that were lactating...

Psychophysiological and self-reported reactivity associated with social anxiety and public speaking fear symptoms: Effects of fear versus distress.

Science.gov (United States)

Panayiotou, Georgia; Karekla, Maria; Georgiou, Dora; Constantinou, Elena; Paraskeva-Siamata, Michaela

2017-09-01

This study examines psychophysiological and subjective reactivity to anxiety-provoking situations in relation to social anxiety and public speaking fear. We hypothesized that social anxiety symptoms would be associated with similar reactivity across types of imaginary anxiety scenes and not specifically to social anxiety-related scenes. This would be attributed to co-existing depression symptoms. Public speaking fear was expected to be associated with more circumscribed reactivity to survival-threat scenes, due to its association with fearfulness. Community participants imagined standardized anxiety situations, including social anxiety and animal fear scenes, while their physiological reactivity and self-reported emotions were assessed. Findings supported that social anxiety was associated with undifferentiated physiological reactivity across anxiety-provoking situations, except with regards to skin conductance level, which was higher during social anxiety imagery. Public speaking fear was associated with increased reactivity to animal phobia and panic scenes. Covariance analyses indicated that the lack of response specificity associated with social anxiety could be attributed to depression levels, while the specificity associated with public speaking fear could be explained by fearfulness. Findings highlight the need to assess not only primary anxiety symptoms but also depression and fearfulness, which likely predict discrepant reactions of individuals to anxiogenic situations. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Aging decreases CO2 reactivity in the retinal artery, but not in the ocular choroidal vessels; a cross-sectional study.

Science.gov (United States)

Miyaji, Akane; Ikemura, Tsukasa; Hayashi, Naoyuki

2018-04-14

The CO2 reactivity is often used to assess vascular function, but it is still unclear whether this reactivity is affected by aging. To investigate the effects of aging on the CO2 reactivity in ocular and cerebral vessels, both of which are highly sensitive to hypercapnia, we compared the CO2 reactivity in the retinal artery (RA), retinal and choroidal vessels (RCV), optic nerve head (ONH), and middle cerebral artery (MCA) between young and middle-aged subjects. We measured the CO2 reactivity in 14 young and 11 middle-aged males using laser-speckle flowgraphy during a 3-min inhalation of CO2-rich air. The CO2 reactivity in the RA and ONH were lower in the middle-aged group than in the young group, but no significant effect of age was observed in the RCV or MCA. The CO2 reactivity in the RA and ONH were correlated significantly with age, whereas those in the RCV or MCA were not. These findings suggest that there are regional differences in the effect of age on the CO2 reactivity among not only ocular and cerebral vessels, but also the retinal and choroidal vessels, even though these vessels are in neighboring areas.

Three-Week Bright-Light Intervention Has Dose-Related Effects on Threat-Related Corticolimbic Reactivity and Functional Coupling

DEFF Research Database (Denmark)

Fisher, Patrick M; Madsen, Martin K; Mc Mahon, Brenda

2014-01-01

environmental stimuli (e.g., threat) and may underlie these effects. Serotonin signaling modulates this circuit and is implicated in the pathophysiology of seasonal and other affective disorders. METHODS: We evaluated the effects of a bright-light intervention protocol on threat-related corticolimbic reactivity......-related amygdala and prefrontal reactivity in a dose-dependent manner. Conversely, amygdala-prefrontal and intraprefrontal functional coupling increased significantly in a dose-dependent manner. Genotype status significantly moderated bright-light intervention effects on intraprefrontal functional coupling....... CONCLUSIONS: This is the first study to evaluate the effects of clinically relevant bright-light intervention on threat-related brain function. We show that amygdala-prefrontal reactivity and communication are significantly affected by bright-light intervention, an effect partly moderated by genotype...

Reactive solute transport in physically and chemically heterogeneous porous media with multimodal reactive mineral facies: the Lagrangian approach.

Science.gov (United States)

Soltanian, Mohamad Reza; Ritzi, Robert W; Dai, Zhenxue; Huang, Chao Cheng

2015-03-01

Physical and chemical heterogeneities have a large impact on reactive transport in porous media. Examples of heterogeneous attributes affecting reactive mass transport are the hydraulic conductivity (K), and the equilibrium sorption distribution coefficient (Kd). This paper uses the Deng et al. (2013) conceptual model for multimodal reactive mineral facies and a Lagrangian-based stochastic theory in order to analyze the reactive solute dispersion in three-dimensional anisotropic heterogeneous porous media with hierarchical organization of reactive minerals. An example based on real field data is used to illustrate the time evolution trends of reactive solute dispersion. The results show that the correlation between the hydraulic conductivity and the equilibrium sorption distribution coefficient does have a significant effect on reactive solute dispersion. The anisotropy ratio does not have a significant effect on reactive solute dispersion. Furthermore, through a sensitivity analysis we investigate the impact of changing the mean, variance, and integral scale of K and Kd on reactive solute dispersion. Copyright © 2014 Elsevier Ltd. All rights reserved.

The influence of spatial effects on the measurement results of reactivity in 'fast disturbances' of core parameters

International Nuclear Information System (INIS)

Tsyganov, S.V.; Shishkov, L.K.

2001-01-01

The analysis of methods for the determination of reactivity revealed an essential influence of spatial effect on the measurement precision. Using of reverse point kinetic equation for reactivity meter is assumed that the average neutron flux weigh with the importance function is known at every moment of the transient. In fact, reactivity meter represent behaviour of the neutron flux only of the part of the core, so measured value of reactivity can differ from really reactivity. Three-dimensional dynamic model of the core allow to evaluate such difference. It is supposed to evaluate correction factor for the neutron flux measured at the place where ion chamber situated with the three-dimensional model NOSTRA of the WWER core. On the basis of such algorithm we propose to build module allowing the influence of spatial effects on the results of the reactivity meter to be eliminated at real time regime. This code will be incorporated into the core monitoring system 'BLOK' (SCORPIO type) which is being developed for the Kola and Rostov NPP. The report illustrates utilization of such algorithm (Authors)

The bystander effect: is reactive oxygen species the driver?

International Nuclear Information System (INIS)

Szumiel, I.

2003-01-01

The paper reviews selected examples of the bystander effect, such as clonogenic survival decrease, chromosomal aberrations and mutations. The similarities and differences between the biological effects in directly targeted and bystander cells are briefly discussed. Also reviewed are the experimental data which support the role of reactive oxygen species (ROS), especially *O 2 - , as mediators of the bystander effect. Endogenously generated ROS, due to activation of NAD(P)H oxidases, play a kay role in the introduction of DNA damage in bystander cells. All the observed effects in bystander cells, such as alteration in gene expression patterns, chromosomal aberrations, sister chromatid exchanges, mutations, genome instability and neoplastic transformation are the consequence of DNA damage. (author)

Reactive sites influence in PMMA oligomers reactivity: a DFT study

Science.gov (United States)

Paz, C. V.; Vásquez, S. R.; Flores, N.; García, L.; Rico, J. L.

2018-01-01

In this work, we present a theoretical study of methyl methacrylate (MMA) living anionic polymerization. The study was addressed to understanding two important experimental observations made for Michael Szwarc in 1956. The unexpected effect of reactive sites concentration in the propagation rate, and the self-killer behavior of MMA (deactivating of living anionic polymerization). The theoretical calculations were performed by density functional theory (DFT) to obtain the frontier molecular orbitals values. These values were used to calculate and analyze the chemical interaction descriptors in DFT-Koopmans’ theorem. As a result, it was observed that the longest chain-length species (related with low concentration of reactive sites) exhibit the highest reactivity (behavior associated with the increase of the propagation rate). The improvement in this reactivity was attributed to the crosslinking produced in the polymethyl methacrylate chains. Meanwhile, the self-killer behavior was associated with the intermolecular forces present in the reactive sites. This behavior was associated to an obstruction in solvation, since the active sites remained active through all propagation species. The theoretical results were in good agreement with the Szwarc experiments.

Inherent safety that the reactivity effect of core bending in fast reactors brings about

International Nuclear Information System (INIS)

Nakagawa, Masatoshi; Yagawa, Genki.

1994-01-01

FBRs have the merit on safety by low operation pressure and the large heat capacity of coolant, in addition, due to the core temperature rise at the time of accidents and the thermal expansion of core structures, the negative feedback of reactivity can be expected. Recently, attention has been paid to the negative feedback of reactivity due to core bending. It can be expected also in the core of limited free bow type. Bending is caused by the difference of thermal expansion on six surfaces of hexagonal wrapper tubes. The bending changes core reactivity and exerts effects to fuel exchange force and operation, insertion of control rods and the structural soundness of fuel assemblies. for the purpose of limiting the effect that core bending exerts to core characteristics to allowable range, core constraint mechanism is installed. The behavior of core bending at the time of anticipated transient without scram is explained. The example of the analysis of PRISM reactor is shown. The experiment that confirmed the negative feedback of reactivity due to core bending under the condition of ULOF was that at the fast flux test facility. (K.I.)

Moderate alcohol consumption reduces plasma C-reactive protein and fibrinogen levels : a randomized, diet-controlled intervention study

NARCIS (Netherlands)

Sierksma, A.; Gaag, M.S. van der; Kluft, C.; Hendriks, H.F.J.

2002-01-01

Objective: To evaluate the effect of moderate alcohol consumption on the acute phase proteins C-reactive protein and fibrinogen. Design: Randomized, diet-controlled, cross-over study. Setting: The study was performed at TNO Nutrition and Food Research, Zeist, The Netherlands. Subjects: Ten

Impact of long-term meditation practice on cardiovascular reactivity during perception and reappraisal of affective images.

Science.gov (United States)

Pavlov, Sergei V; Reva, Natalia V; Loktev, Konstantin V; Korenyok, Vladimir V; Aftanas, Lyubomir I

2015-03-01

Meditation has been found to be an efficient strategy for coping with stress in healthy individuals and in patients with psychosomatic disorders. The main objective of the present study was to investigate the psychophysiological mechanisms of beneficial effects of meditation on cardiovascular reactivity. We examined effects of long-term Sahaja Yoga meditation on cardiovascular reactivity during affective image processing under "unregulated" and "emotion regulation" conditions. Twenty two experienced meditators and 20 control subjects participated in the study. Under "unregulated" conditions participants were shown neutral and affective images and were asked to attend to them. Under "emotion regulation" conditions they down-regulated negative affect through reappraisal of negative images or up-regulated positive affect through reappraisal of positive images. Under "unregulated" conditions while anticipating upcoming images meditators vs. controls did not show larger pre-stimulus total peripheral resistance and greater cardiac output for negative images in comparison with neutral and positive ones. Control subjects showed TPR decrease for negative images only when they consciously intended to reappraise them (i.e. in the "emotion regulation" condition). Both meditators and controls showed comparable cardiovascular reactivity during perception of positive stimuli, whereas up-regulating of positive affect was associated with more pronounced cardiac activation in meditators. The findings provide some insight into understanding the beneficial influence of meditation on top-down control of emotion and cardiovascular reactivity. Copyright © 2015 Elsevier B.V. All rights reserved.

Regarding KUR Reactivity Measurement System

International Nuclear Information System (INIS)

Nakamori, Akira; Hasegawa, Kei; Tsuchiyama, Tatsuo; Yamamoto, Toshihiro; Okumura, Ryo; Sano, Tadafumi

2012-01-01

This article reported: (1) the outline of the reactivity measurement system of Kyoto University Research Reactor (KUR), (2) the calibration data of control rod, (3) the problems and the countermeasures for range switching of linear output meter. For the laptop PC for the reactivity measurement system, there are four input signals: (1) linear output meter, (2) logarithmic output meter, (3) core temperature gauge, and (4) control rod position. The hardware of reactivity measurement system is controlled with Labview installed on the laptop. Output, reactivity, reactor period, and the change in reactivity due to temperature effect or Xenon effect are internally calculated and displayed in real-time with Labview based on the four signals above. Calculation results are recorded in the form of a spreadsheet. At KUR, the reactor core arrangement was changed, so the control rod was re-calibrated. At this time, calculated and experimental values of reactivity based on the reactivity measurement system were compared, and it was confirmed that the reactivity calculation by Labview was accurate. The range switching of linear output meter in the nuclear instrumentation should automatically change within the laptop, however sometimes this did not function properly in the early stage. It was speculated that undefined percent values during the transition of percent value were included in the calculation and caused calculation errors. The range switching started working properly after fixing this issue. (S.K.)

Parent emotion socialization and pre-adolescent's social and emotional adjustment: Moderating effects of autonomic nervous system reactivity.

Science.gov (United States)

McQuade, Julia D; Breaux, Rosanna P

2017-12-01

This study examined whether measures of children's autonomic nervous system (ANS) reactivity to social stress moderated the effect of parent emotion socialization on children's social and emotional adjustment. Sixty-one children (9-13 years) completed a peer rejection task while their respiratory sinus arrhythmia reactivity (RSA-R) and skin conductance level reactivity (SCL-R) were assessed. Parents' report of supportive and non-supportive reactions to their child's negative emotions served as measures of emotion socialization. Measures of children's social and emotional adjustment included: teacher-rated peer rejection, aggression, and prosocial behavior and parent-rated aggressive/dysregulated behavior and emotion regulation skills. Measures of children's ANS reactivity moderated the effect of parent emotion socialization on children's adjustment. Supportive responses were more protective for children evidencing RSA augmentation whereas non-supportive responses were more detrimental for children evidencing low SCL-R. Thus children's ANS reactivity during social stress may represent a biological vulnerability that influences sensitivity to parent emotion socialization. Copyright © 2017 Elsevier B.V. All rights reserved.

Metamemory ratings predict long-term changes in reactivated episodic memories

Directory of Open Access Journals (Sweden)

Amnon eYacoby

2015-02-01

Full Text Available Reactivation of long-term memory can render the memory item temporarily labile, offering an opportunity to modify it via behavioral or pharmacological intervention. Declarative memory reactivation is accompanied by a metamemory ability to subjectively assess the knowledge available concerning the target item (Feeling of knowing, FOK. We set out to examine whether FOK can predict the extent of change of long-term episodic memories by post-retrieval manipulations. To this end, participants watched a short movie and immediately thereafter tested on their memory for it. A day later, they were reminded of that movie, and either immediately or one day later, were presented with a second movie. The reminder phase consisted of memory cues to which participants were asked to judge their FOK regarding the original movie. The memory performance of participants to whom new information was presented immediately after reactivating the original episode corresponded to the degree of FOK ratings upon reactivation such that the lower their FOK, the less their memory declined. In contrast, no relation was found between FOK and memory strength for those who learned new information one day after the reminder phase. Our findings suggest that the subjective accessibility of reactivated memories may determine the extent to which new information might modify those memories.

Effect of nigella sativa seeds extract on serum c-reactive protein in albino rats

International Nuclear Information System (INIS)

Bashir, M.U.; Qureshi, H.

2014-01-01

C-reactive protein (CRP) is an acute phase protein. It predicts future risk of cardiovascular diseases. Different medicinal plants and their active ingredients possess the ability to reduce serum CRP levels and hence inflammatory disorders and cardiovascular diseases. In our study, ethanolic extract of Nigella sativa seeds was evaluated in albino rats for its possible effect on serum CRP levels. Objective: The objective of this study was to determine the effect of ethanolic extract of Nigella sativa seeds on an acute inflammatory biomarker/mediator, C-reactive protein (CRP) in albino rats. Study Design: Randomized controlled trial (RCT). Place and Duration of Study: Physiology Department, Services Institute of Medical Sciences (SIMS), Lahore; from September to November, 2009. Subjects and Methods: The study was carried out on 90 male albino rats. Five percent (5%) formalin in a dose of 50 meu1 was injected into sub-plantar surface of right hind paw of each rat to produce inflammation. The rats were randomly divided into three groups of thirty each. Group A was given normal saline (control); group B was given Nigella sativa seed extract; and group C received diclofenac sodium, as a reference drug. CRP levels in each group were measured from blood samples taken 25 hours after giving formalin. Results: The ethanolic extract of Nigella sativa seeds, given intraperitoneally, caused highly significant (p<0.001) reduction in serum CRP levels as compared to control group. The reduction in CRP levels by ethanolic extract of Nigella sativa was also significantly (p<0.05) more than that produced by diclofenac sodium. Conclusion: Our results suggest that Nigella sativa possesses ability to reduce serum CRP levels significantly, after production of artificial inflammation, in albino rats. (author)

Sex Differences in High Sensitivity C-Reactive Protein in Subjects with Risk Factors of Metabolic Syndrome

Directory of Open Access Journals (Sweden)

Vinicius Pacheco Garcia

2016-03-01

Full Text Available Abstract Background: Metabolic syndrome (MetS is associated with a higher risk of all-cause mortality. High-sensitivity C-reactive protein (hsCRP is a prototypic marker of inflammation usually increased in MetS. Women with MetS-related diseases present higher hsCRP levels than men with MetS-related diseases, suggesting sex differences in inflammatory markers. However, it is unclear whether serum hsCRP levels are already increased in men and/or women with MetS risk factors and without overt diseases or under pharmacological treatment. Objective: To determine the impact of the number of MetS risk factors on serum hsCRP levels in women and men. Methods One hundred and eighteen subjects (70 men and 48 women; 36 ± 1 years were divided into four groups according to the number of MetS risk factors: healthy group (CT; no risk factors, MetS ≤ 2, MetS = 3, and MetS ≥ 4. Blood was drawn after 12 hours of fasting for measurement of biochemical variables and hsCRP levels, which were determined by immunoturbidimetric assay. Results: The groups with MetS risk factors presented higher serum hsCRP levels when compared with the CT group (p 0.05. The best linear regression model to explain the association between MetS risk factors and hsCRP levels included waist circumference and HDL cholesterol (r = 0.40, p < 0.01. Women with MetS risk factors presented higher hsCRP levels when compared with men (psex < 0.01. Conclusions: Despite the absence of overt diseases and pharmacological treatment, subjects with MetS risk factors already presented increased hsCRP levels, which were significantly higher in women than men at similar conditions.

Sex Differences in High Sensitivity C-Reactive Protein in Subjects with Risk Factors of Metabolic Syndrome

International Nuclear Information System (INIS)

Garcia, Vinicius Pacheco; Rocha, Helena Naly Miguens; Sales, Allan Robson Kluser; Rocha, Natália Galito; Nóbrega, Antonio Claudio Lucas da

2016-01-01

Metabolic syndrome (MetS) is associated with a higher risk of all-cause mortality. High-sensitivity C-reactive protein (hsCRP) is a prototypic marker of inflammation usually increased in MetS. Women with MetS-related diseases present higher hsCRP levels than men with MetS-related diseases, suggesting sex differences in inflammatory markers. However, it is unclear whether serum hsCRP levels are already increased in men and/or women with MetS risk factors and without overt diseases or under pharmacological treatment. To determine the impact of the number of MetS risk factors on serum hsCRP levels in women and men. One hundred and eighteen subjects (70 men and 48 women; 36 ± 1 years) were divided into four groups according to the number of MetS risk factors: healthy group (CT; no risk factors), MetS ≤ 2, MetS = 3, and MetS ≥ 4. Blood was drawn after 12 hours of fasting for measurement of biochemical variables and hsCRP levels, which were determined by immunoturbidimetric assay. The groups with MetS risk factors presented higher serum hsCRP levels when compared with the CT group (p < 0.02). There were no differences in hsCRP levels among groups with MetS risk factors (p > 0.05). The best linear regression model to explain the association between MetS risk factors and hsCRP levels included waist circumference and HDL cholesterol (r = 0.40, p < 0.01). Women with MetS risk factors presented higher hsCRP levels when compared with men (p sex < 0.01). Despite the absence of overt diseases and pharmacological treatment, subjects with MetS risk factors already presented increased hsCRP levels, which were significantly higher in women than men at similar conditions

Sex Differences in High Sensitivity C-Reactive Protein in Subjects with Risk Factors of Metabolic Syndrome

Energy Technology Data Exchange (ETDEWEB)

Garcia, Vinicius Pacheco; Rocha, Helena Naly Miguens [Laboratório de Ciências do Exercício - Departamento de Fisiologia e Farmacologia - Universidade Federal Fluminense, Niterói, RJ (Brazil); Sales, Allan Robson Kluser [Unidade de Reabilitação Cardiovascular e Fisiologia do Exercício - Instituto do Coração (InCor) - Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP (Brazil); Rocha, Natália Galito; Nóbrega, Antonio Claudio Lucas da, E-mail: anobrega@id.uff.br [Laboratório de Ciências do Exercício - Departamento de Fisiologia e Farmacologia - Universidade Federal Fluminense, Niterói, RJ (Brazil)

2016-03-15

Metabolic syndrome (MetS) is associated with a higher risk of all-cause mortality. High-sensitivity C-reactive protein (hsCRP) is a prototypic marker of inflammation usually increased in MetS. Women with MetS-related diseases present higher hsCRP levels than men with MetS-related diseases, suggesting sex differences in inflammatory markers. However, it is unclear whether serum hsCRP levels are already increased in men and/or women with MetS risk factors and without overt diseases or under pharmacological treatment. To determine the impact of the number of MetS risk factors on serum hsCRP levels in women and men. One hundred and eighteen subjects (70 men and 48 women; 36 ± 1 years) were divided into four groups according to the number of MetS risk factors: healthy group (CT; no risk factors), MetS ≤ 2, MetS = 3, and MetS ≥ 4. Blood was drawn after 12 hours of fasting for measurement of biochemical variables and hsCRP levels, which were determined by immunoturbidimetric assay. The groups with MetS risk factors presented higher serum hsCRP levels when compared with the CT group (p < 0.02). There were no differences in hsCRP levels among groups with MetS risk factors (p > 0.05). The best linear regression model to explain the association between MetS risk factors and hsCRP levels included waist circumference and HDL cholesterol (r = 0.40, p < 0.01). Women with MetS risk factors presented higher hsCRP levels when compared with men (p{sub sex} < 0.01). Despite the absence of overt diseases and pharmacological treatment, subjects with MetS risk factors already presented increased hsCRP levels, which were significantly higher in women than men at similar conditions.

Effect of Anisotropy Structure on Plume Entropy and Reactive Mixing in Helical Flows

DEFF Research Database (Denmark)

Ye, Yu; Chiogna, Gabriele; Lu, Chunhui

2018-01-01

Plume dilution and reactive mixing can be considerably enhanced by helical flows occurring in three-dimensional anisotropic porous media. In this study, we perform conservative and reactive transport simulations considering different anisotropy structures of a single inclusion with the objective...... of exploring the effect of the inclusion’s geometry and orientation on the patterns of twisted streamlines and on the overall dilution and reaction of solute plumes. We analyzed 100 different scenarios by varying key parameters such as the angle of the anisotropic structures with respect to the average flow...... velocity, the spacing between alternated heterogeneous zones of coarse and fine materials, the permeability contrast between such matrices, and the magnitude of the seepage velocity. Entropy conservation equations and entropy-based metrics for both conservative and reactive species were adopted to quantify...

Anger Modulates Influence Hierarchies Within and Between Emotional Reactivity and Regulation Networks

Science.gov (United States)

Jacob, Yael; Gilam, Gadi; Lin, Tamar; Raz, Gal; Hendler, Talma

2018-01-01

Emotion regulation is hypothesized to be mediated by the interactions between emotional reactivity and regulation networks during the dynamic unfolding of the emotional episode. Yet, it remains unclear how to delineate the effective relationships between these networks. In this study, we examined the aforementioned networks’ information flow hierarchy during viewing of an anger provoking movie excerpt. Anger regulation is particularly essential for averting individuals from aggression and violence, thus improving prosocial behavior. Using subjective ratings of anger intensity we differentiated between low and high anger periods of the film. We then applied the Dependency Network Analysis (DEPNA), a newly developed graph theory method to quantify networks’ node importance during the two anger periods. The DEPNA analysis revealed that the impact of the ventromedial prefrontal cortex (vmPFC) was higher in the high anger condition, particularly within the regulation network and on the connections between the reactivity and regulation networks. We further showed that higher levels of vmPFC impact on the regulation network were associated with lower subjective anger intensity during the high-anger cinematic period, and lower trait anger levels. Supporting and replicating previous findings, these results emphasize the previously acknowledged central role of vmPFC in modulating negative affect. We further show that the impact of the vmPFC relies on its correlational influence on the connectivity between reactivity and regulation networks. More importantly, the hierarchy network analysis revealed a link between connectivity patterns of the vmPFC and individual differences in anger reactivity and trait, suggesting its potential therapeutic role. PMID:29681803

Energy transfer in reactive and non-reactive H2 + OH collisions

International Nuclear Information System (INIS)

Rashed, O.; Brown, N.J.

1985-04-01

We have used the methods of quasi-classical dynamics to compute energy transfer properties of non-reactive and reactive H 2 + OH collisions. Energy transfer has been investigated as function of translational temperature, reagent rotational energy, and reagent vibrational energy. The energy transfer mechanism is complex with ten types of energy transfer possible, and evidence was found for all types. There is much more exchange between the translational degree of freedom and the H 2 vibrational degree of freedom than there is between translation and OH vibration. Translational energy is transferred to the rotational degrees of freedom of each molecule. There is a greater propensity for the transfer of translation to OH rotation than H 2 rotation. In reactive collisions, increases in reagent translational temperature predominantly appear as vibrational energy in the water molecule. Energy transfer in non-reactive and reactive collisions does not depend strongly on the initial angular momentum in either molecule. In non-reactive collisions, vibrational energy is transferred to translation, to the rotational degree of freedom of the same molecule, and to the rotational and vibrational degrees of freedom of the other molecule. In reactive collisions, the major effect of increasing the vibrational energy in reagent molecules is that, on the average, the vibrational energy of the reagents appears as product vibrational energy. 18 refs., 16 figs., 6 tabs

Role of histamine receptors in the effects of histamine on the production of reactive oxygen species by whole blood phagocytes

Czech Academy of Sciences Publication Activity Database

Vašíček, Ondřej; Lojek, Antonín; Jančinová, V.; Nosál, R.; Číž, Milan

2014-01-01

Roč. 100, č. 1 (2014), s. 67-72 ISSN 0024-3205 R&D Projects: GA MŠk(CZ) LD11010 Institutional support: RVO:68081707 Keywords : Histamine * Histamine receptors * Reactive oxygen species Subject RIV: BO - Biophysics Impact factor: 2.702, year: 2014

Biodecolorization and biodegradation of Reactive Blue by ...

African Journals Online (AJOL)

SERVER

2007-06-18

Jun 18, 2007 ... Aspergillus sp. effectively decolorized Reactive Blue and other structurally different synthetic dyes. Agitation was found to be an important ... Few chemically different dyes such as Reactive Black (75%), Reactive Yellow (70%),. Reactive Red (33%) and ..... Degradation of azo dyes by the lignin degrading ...

Omega-3 Polyunsaturated Fatty Acids Enriched Hen Eggs Consumption Enhances Microvascular Reactivity in Young Healthy Individuals.

Science.gov (United States)

Stupin, Ana; Rasic, Lidija; Matic, Anita; Stupin, Marko; Kralik, Zlata; Kralik, Gordana; Grcevic, Manuela; Drenjancevic, Ines

2018-04-10

Whilst the beneficial effect of omega-3 polyunsaturated fatty acids (PUFAs) supplementation on cardiovascular (CV) system is well supported in CV patients, the effect of consumption of omega-3 PUFAs enriched functional food in healthy individuals is still not fully elucidated. This study aimed to determine the effect of consumption of omega-3 PUFAs enriched hen eggs on microvascular reactivity (primary outcome), blood pressure (BP) and serum lipid profile in young healthy individuals. Control group (N=16) ate three ordinary hen eggs (277 mg omega-3 PUFAs/day), and OMEGA-3 group (N=20) ate three omega-3 PUFAs enriched eggs containing 259 mg of omega-3 PUFAs/egg daily (ALA 167 mg/egg, EPA 7 mg/egg, DHA 84 mg/egg) for 3 weeks (777 mg omega-3 PUFAs/day). Post-occlusive reactive hyperemia (PORH) in skin microcirculation assessed by laser Doppler flowmetry, serum lipid profile, fasting blood glucose, high-sensitivity C-reactive protein (hsCRP) and arterial BP were measured in all subjects before and after the protocol. PORH was significantly enhanced, and triglycerides, hsCRP and BP were significantly decreased in OMEGA-3 group compared to baseline measurement, while there was no significant difference in Control group after the protocol compared to baseline. This is the first study to demonstrate that consumption of a mixture of omega-3 PUFAs (ALA+EPA+DHA), provided via enriched hen eggs, elicits changes in microvascular reactivity, BP and triglycerides level in healthy subjects that are associated with CV benefits, thus suggesting that daily consumption of omega-3 PUFAs enriched eggs in healthy individuals may potentially contribute to CV risk factors attenuation and disease prevention.

Functional neuroimaging studies in addiction: multisensory drug stimuli and neural cue reactivity.

Science.gov (United States)

Yalachkov, Yavor; Kaiser, Jochen; Naumer, Marcus J

2012-02-01

Neuroimaging studies on cue reactivity have substantially contributed to the understanding of addiction. In the majority of studies drug cues were presented in the visual modality. However, exposure to conditioned cues in real life occurs often simultaneously in more than one sensory modality. Therefore, multisensory cues should elicit cue reactivity more consistently than unisensory stimuli and increase the ecological validity and the reliability of brain activation measurements. This review includes the data from 44 whole-brain functional neuroimaging studies with a total of 1168 subjects (812 patients and 356 controls). Correlations between neural cue reactivity and clinical covariates such as craving have been reported significantly more often for multisensory than unisensory cues in the motor cortex, insula and posterior cingulate cortex. Thus, multisensory drug cues are particularly effective in revealing brain-behavior relationships in neurocircuits of addiction responsible for motivation, craving awareness and self-related processing. Copyright © 2011 Elsevier Ltd. All rights reserved.

Reducing Schoolchildren With Reactive Aggression Through Child, Parent, and Conjoint Parent-Child Group Interventions: A Longitudinal Outcome Effectiveness Study.

Science.gov (United States)

Fung, Annis Lai Chu

2017-10-10

This study was the first to evaluate the effectiveness of three different group interventions to reduce children's reactive aggression based on the social information processing (SIP) model. In the first stage of screening, 3,734 children of Grades 4-6 completed the Reactive-Proactive Aggression Questionnaire (RPQ) to assess their reactive and proactive aggression. Respondents with a total score of z ≥ 1 on the RPQ were shortlisted for the second stage of screening by qualitative interview. Interviews with 475 children were conducted to select those who showed reactive aggression featuring a hostile attributional bias. Finally, 126 children (97 males and 29 females) aged 8 to 14 (M = 9.71, SD = 1.23) were selected and randomly assigned to one of the three groups: a child group, a parent group, and a parent-child group. A significant Time × Intervention effect was found for general and reactive aggression. The parent-child group and child group showed a significant drop in general aggression and reactive aggression from posttest to 6-month follow-up, after controlling for baseline scores, sex, and age. However, the parent group showed no treatment effect: reactive aggression scores were significantly higher than those in the child group at 6-month follow-up. This study has provided strong evidence that children with reactive aggression need direct and specific treatment to reconstruct the steps of the SIP involving the selection and interpretation of cues. The intervention could help to prevent severe violent crimes at the later stage of a reactive aggressor. © 2017 Family Process Institute.

Changes in cue reactivity and attentional bias following experimental cue exposure and response prevention: a laboratory study of the effects of D-cycloserine in heavy drinkers.

Science.gov (United States)

Kamboj, Sunjeev K; Massey-Chase, Rachel; Rodney, Lydia; Das, Ravi; Almahdi, Basil; Curran, H Valerie; Morgan, Celia J A

2011-09-01

The effects of D-cycloserine (DCS) in animal models of anxiety disorders and addiction indicate a role for N-methyl D-aspartate (NMDA) receptors in extinction learning. Exposure/response prevention treatments for anxiety disorders in humans are enhanced by DCS, suggesting a promising co-therapy regime, mediated by NMDA receptors. Exposure/response prevention may also be effective in problematic drinkers, and DCS might enhance habituation to cues in these individuals. Since heavy drinkers show ostensible conditioned responses to alcohol cues, habituation following exposure/response prevention should be evident in these drinkers, with DCS enhancing this effect. The objective of this study is to investigate the effect of DCS on exposure/response prevention in heavy drinkers. In a randomised, double-blind, placebo-controlled study, heavy social drinkers recruited from the community received either DCS (125 mg; n = 19) or placebo (n = 17) 1 h prior to each of two sessions of exposure/response prevention. Cue reactivity and attentional bias were assessed during these two sessions and at a third follow-up session. Between-session drinking behaviour was recorded. Robust cue reactivity and attentional bias to alcohol cues was evident, as expected of heavy drinkers. Within- and between-session habituation of cue reactivity, as well as a reduction in attentional bias to alcohol cues over time was found. However, there was no evidence of greater habituation in the DCS group. Subtle stimulant effects (increased subjective contentedness and euphoria) which were unrelated to exposure/response prevention were found following DCS. DCS does not appear to enhance habituation of alcohol cue reactivity in heavy non-dependent drinkers. Its utility in enhancing treatments based on exposure/response prevention in dependent drinkers or drug users remains open.

Radial core expansion reactivity feedback in advanced LMRs: uncertainties and their effects on inherent safety

International Nuclear Information System (INIS)

Wigeland, R.A.; Moran, T.J.

1988-01-01

An analytical model for calculating radial core expansion, based on the thermal and elastic bowing of a single subassembly at the core periphery, is used to quantify the effect of uncertainties on this reactivity feedback mechanism. This model has been verified and validated with experimental and numerical results. The impact of these uncertainties on the safety margins in unprotected transients is investigated with SASSYS/SAS4A, which includes this model for calculating the reactivity feedback from radial core expansion. The magnitudes of these uncertainties are not sufficient to preclude the use of radial core expansion reactivity feedback in transient analysis

Oral Topical Doxepin Rinse: Anesthetic Effect in Normal Subjects

Directory of Open Access Journals (Sweden)

Joel B Epstein

2003-01-01

Full Text Available Oral doxepin rinse has been reported to provide pain relief in patients with oral mucosal lesions due to cancer or cancer therapy. The purpose of this study was to assess the anesthetic effect of doxepin oral rinse in normal subjects to identify the duration of effect and to contrast the anesthetic effect with reported pain relief in patients with oral mucosal lesions. Normal volunteers were provided a solution of doxepin (5 mg/mL for oral rinsing. Oral numbness and adverse effects were recorded for a period of 4 h after rinsing. Doxepin rinse resulted in mucosal anesthesia in all subjects. Sedation/fatigue was reported in four of seven subjects. There were no taste complaints and no nausea reported. The limited duration of numbness/anesthesia in normal subjects compared with prior studies showing pain relief for more than 3 h in patients with mucosal lesions, suggests that the extended duration of pain relief in patients was due to analgesic effects rather than anesthetic effects. The majority of normal subjects reported sedation after use, but this was less common in patients with mucosal lesions.

Effects of Human C-Reactive Protein on Pathogenesis of Features of the Metabolic Syndrome

Czech Academy of Sciences Publication Activity Database

Pravenec, Michal; Kajiya, T.; Zídek, Václav; Landa, Vladimír; Mlejnek, Petr; Šimáková, Miroslava; Šilhavý, Jan; Malínská, H.; Oliyarnyk, O.; Kazdová, L.; Fan, J.; Wang, J.; Kurtz, T. W.

2011-01-01

Roč. 57, č. 4 (2011), s. 731-737 ISSN 0194-911X R&D Projects: GA MZd(CZ) NS9759; GA MŠk(CZ) ME08006; GA MŠk(CZ) 1M0520; GA ČR(CZ) GAP301/10/0290; GA ČR GAP303/10/0505; GA AV ČR(CZ) IAA500110805 Grant - others:EC(XE) HEALTH-F4-2010-241504 Institutional research plan: CEZ:AV0Z50110509 Keywords : C-reactive protein * metabolic syndrome * transgenic rat Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 6.207, year: 2011

Estimating sources, sinks and fluxes of reactive atmospheric compounds within a forest canopy

Science.gov (United States)

While few dispute the significance of within-canopy sources or sinks of reactive gaseous and particulate compounds, their estimation continues to be the subject of active research and debate. Reactive species undergo turbulent dispersion within an inhomogeneous flow field, and ma...

Electronic cigarettes: abuse liability, topography and subjective effects.

Science.gov (United States)

Evans, Sarah E; Hoffman, Allison C

2014-05-01

To review the available evidence evaluating the abuse liability, topography, subjective effects, craving and withdrawal suppression associated with e-cigarette use in order to identify information gaps and provide recommendations for future research. Literature searches were conducted between October 2012 and January 2014 using five electronic databases. Studies were included in this review if they were peer-reviewed scientific journal articles evaluating clinical laboratory studies, national surveys or content analyses. A total of 15 peer-reviewed articles regarding behavioural use and effects of e-cigarettes published between 2010 and 2014 were included in this review. Abuse liability studies are limited in their generalisability. Topography (consumption behaviour) studies found that, compared with traditional cigarettes, e-cigarette average puff duration was significantly longer, and e-cigarette use required stronger suction. Data on e-cigarette subjective effects (such as anxiety, restlessness, concentration, alertness and satisfaction) and withdrawal suppression are limited and inconsistent. In general, study data should be interpreted with caution, given limitations associated with comparisons of novel and usual products, as well as the possible effects associated with subjects' previous experience/inexperience with e-cigarettes. Currently, very limited information is available on abuse liability, topography and subjective effects of e-cigarettes. Opportunities to examine extended e-cigarette use in a variety of settings with experienced e-cigarette users would help to more fully assess topography as well as behavioural and subjective outcomes. In addition, assessment of 'real-world' use, including amount and timing of use and responses to use, would clarify behavioural profiles and potential adverse health effects.

Termination of nanoscale zero-valent iron reactivity by addition of bromate as a reducing reactivity competitor

Science.gov (United States)

Mines, Paul D.; Kaarsholm, Kamilla M. S.; Droumpali, Ariadni; Andersen, Henrik R.; Lee, Wontae; Hwang, Yuhoon

2017-09-01

Remediation of contaminated groundwater by nanoscale zero-valent iron (nZVI) is widely becoming a leading environmentally friendly solution throughout the globe. Since a wide range of various nZVI-containing materials have been developed for effective remediation, it is necessary to determine an appropriate way to terminate the reactivity of any nZVI-containing material for a practical experimental procedure. In this study, bimetallic Ni/Fe-NPs were prepared to enhance overall reduction kinetics owing to the catalytic reactivity of nickel on the surface of nZVI. We have tested several chemical strategies in order to terminate nZVI reactivity without altering the concentration of volatile compounds in the solution. The strategies include surface passivation in alkaline conditions by addition of carbonate, and consumption of nZVI by a reaction competitor. Four halogenated chemicals, trichloroethylene, 1,1,1-trichloroethane, atrazine, and 4-chlorophenol, were selected and tested as model groundwater contaminants. Addition of carbonate to passivate the nZVI surface was not effective for trichloroethylene. Nitrate and then bromate were applied to competitively consume nZVI by their faster reduction kinetics. Bromate proved to be more effective than nitrate, subsequently terminating nZVI reactivity for all four of the tested halogenated compounds. Furthermore, the suggested termination method using bromate was successfully applied to obtain trichloroethylene reduction kinetics. Herein, we report the simple and effective method to terminate the reactivity of nZVI by addition of a reducing reactivity competitor.

Study of the Reactive-element Effect in Oxidation of Fe-cr Alloys Using Transverse Section Analytical Electron Microscopy

Science.gov (United States)

King, W. E.; Ethridge, E. C.

1985-01-01

The role of trace additions of reactive elements like Y, Ce, Th, or Hf to Cr bearing alloys was studied by applying a new developed technique of transverse section analytical electron microscopy. This reactive-element effect improves the high temperature oxidation resistance of alloys by strongly reducing the high temperature oxidation rate and enhancing the adhesion of the oxide scale, however, the mechanisms for this important effect remain largely unknown. It is indicated that the presence of yttrium affects the oxidation of Fe-Cr-Y alloys in at least two ways. The reactive element alters the growth mechanism of the oxide scale as evidenced by the marked influence of the reactive element on the oxide scale microstructure. The present results also suggest that reactive-element intermetallic compounds, which internally oxidize in the metal during oxidation, act as sinks for excess vacancies thus inhibiting vacancy condensation at the scale-metal interface and possibly enhancing scale adhesion.

H3N2 influenza infection elicits more cross-reactive and less clonally expanded anti-hemagglutinin antibodies than influenza vaccination.

Directory of Open Access Journals (Sweden)

M Anthony Moody

Full Text Available BACKGROUND: During the recent H1N1 influenza pandemic, excess morbidity and mortality was seen in young but not older adults suggesting that prior infection with influenza strains may have protected older subjects. In contrast, a history of recent seasonal trivalent vaccine in younger adults was not associated with protection. METHODS AND FINDINGS: To study hemagglutinin (HA antibody responses in influenza immunization and infection, we have studied the day 7 plasma cell repertoires of subjects immunized with seasonal trivalent inactivated influenza vaccine (TIV and compared them to the plasma cell repertoires of subjects experimentally infected (EI with influenza H3N2 A/Wisconsin/67/2005. The majority of circulating plasma cells after TIV produced influenza-specific antibodies, while most plasma cells after EI produced antibodies that did not react with influenza HA. While anti-HA antibodies from TIV subjects were primarily reactive with single or few HA strains, anti-HA antibodies from EI subjects were isolated that reacted with multiple HA strains. Plasma cell-derived anti-HA antibodies from TIV subjects showed more evidence of clonal expansion compared with antibodies from EI subjects. From an H3N2-infected subject, we isolated a 4-member clonal lineage of broadly cross-reactive antibodies that bound to multiple HA subtypes and neutralized both H1N1 and H3N2 viruses. This broad reactivity was not detected in post-infection plasma suggesting this broadly reactive clonal lineage was not immunodominant in this subject. CONCLUSION: The presence of broadly reactive subdominant antibody responses in some EI subjects suggests that improved vaccine designs that make broadly reactive antibody responses immunodominant could protect against novel influenza strains.

Serum levels of C-reactive protein in adolescents with periodontitis

DEFF Research Database (Denmark)

López, Rodrigo; Baelum, Vibeke; Hedegaard, Chris Juul

2011-01-01

Background: The results of several cross-sectional studies suggested a relationship between periodontitis and higher serum levels of C-reactive protein (CRP). Most of these studies were restricted to adult study groups with severe periodontal inflammation, and the potential effects of confounding...... ng/ml (31 to 183 ng/ml), respectively (P = 0.8). Conclusions: Serum levels of CRP were not significantly higher among subjects with periodontitis than among controls. However, a statistically significant positive association between percentages of sites with bleeding on probing and log...

Renal effects of hyperinsulinaemia in subjects with two hypertensive parents

DEFF Research Database (Denmark)

Andersen, U B; Skøtt, P; Bruun, N E

1999-01-01

aged 18-35 years whose parents both had essential hypertension, and 22 age- and sex-matched subjects whose parents were both normotensive. Diabetes or morbid obesity in any subject or parent excluded the family. The 24-h blood pressure was measured. The subjects received an isocaloric diet with a fixed...... the sodium-retaining effect of insulin was more pronounced in subjects with a strong genetic predisposition to essential hypertension than in subjects with normotensive parents. This effect may contribute to the development of hypertension in subjects with a genetic predisposition to hypertension....

Reinstatement versus Reactivation Effects on Active Memory in Infants.

Science.gov (United States)

Adler, Scott A.; Rovee-Collier, Carolyn; Wilk, Amy

2000-01-01

Four experiments examined whether reinstatement and reactivation reminder paradigms affected memory performance of 102 three-month-olds. Results indicated that a single reinstatement protracted retention twice as long after training as a single reactivation. The novelty of the reminder stimulus also affected duration and specificity of memory in…

Influence of void effects on reactivity of coupled fast-thermal system HERBE

International Nuclear Information System (INIS)

Ljubenov, V.; Milovanovic, S.; Milovanovic, T.; Cuknic, O.

1997-01-01

Coupled fast-thermal system HERBE at the experimental zero power heavy water reactor RB is a system with the significant effects of the neutron leakage and neutron absorption. Presence of a coolant void introduces a new structure in an extremely heterogeneous core. In those conditions satisfactory results of the calculation are acquired only using specified space-energy homogenization procedure. In order to analyze transient appearances and accidental cases of the reactor systems, a procedure for modeling of influence of moderator and coolant loss on reactivity ('void effect') is developed. Reduction of the moderator volume fraction in some fuel channels due to air gaps or steam generation during the accidental moderator boiling, restricts validity of the diffusion approximation in the reactor calculations. In cases of high neutron flux gradients, which are consequence of high neutron absorption, application of diffusion approximation is questionable too. The problem may be solved using transport or Monte Carlo methods, but they are not acceptable in the routine applications. Applying new techniques based on space-energy core homogenization, such as the SPH method or the discontinuity factor method, diffusion calculations become acceptable. Calculations based on the described model show that loss of part of moderator medium introduce negative reactivity in the HERBE system. Calculated local void reactivity coefficients are used in safety analysis of hypothetical accidents

Recruiting phobic research subjects: effectiveness and cost.

Science.gov (United States)

Kaakko, T; Murtomaa, H; Milgrom, P; Getz, T; Ramsay, D S; Coldwell, S E

2001-01-01

Efficiently enrolling subjects is one of the most important and difficult aspects of a clinical trial. This prospective study evaluated strategies used in the recruitment of 144 dental injection phobics for a clinical trial evaluating the effectiveness of combining alprazolam with exposure therapy. Three types of recruitment strategies were evaluated: paid advertising, free publicity, and professional referral. Sixty-three percent of subjects were enrolled using paid advertising (the majority of them from bus advertisements [27.0%], posters on the University of Washington campus [20.1%], and newspaper advertisements [13.2%]). Free publicity (eg, television coverage, word of mouth) yielded 18.8% of enrolled subjects and professionaL referrals 14.6% of subjects. The average cost (1996 dollars) of enrolling 1 subject was $79. Bus and poster advertising attracted more initial contacts and yielded the greatest enrollment.

Tectonic reactivation in the Indian Ocean: Evidences from seamount morphology and manganese nodule characteristics

Digital Repository Service at National Institute of Oceanography (India)

Mukhopadhyay, R.; Khadge, N.H.

The Central Indian Ocean Basin (CIOB) was subjected to tectonic reactivation in geological past which is unusual for a basin occurring on an apparently single tectonic plate. ENE-WSW trending latitude parallel zone of reactivation across the central...

Fenton oxidation treatment of spent wash-off liquor for reuse in reactive dying

International Nuclear Information System (INIS)

Mangat, A.; Shaikh, I.A.; Ahmed, F.; Baqar, M

2014-01-01

The use of clean and high quality water in textile dyeing process is very expensive. In this study, the potential of reusing Fenton treated wash-off wastewater generated at the end of reactive dyeing was investigated. The treated wastewater was used in several dyeings employing three widely used reactive dyes, C. I. Reactive Yellow 145, C. I. Reactive Red 194, and C. I. Reactive Blue 221. Experimental results showed that at acidic pH (3.5) using optimized quantities of FeSO/sub 4/ and H/sub 2/O/sub 2/, Fenton process yielded a significant reduction (80-99%) of colour and COD in 30 minutes of treatment time. New dyeings were then carried out in Fenton decolourized wash-off wastewater, and dyed fabric samples were subjected to quality evaluations in terms of wash fastness, crock fastness, and colour difference properties (delta L*, delta c*, delta h*, and delta E*). This study concluded that Fenton oxidation was an efficient method for the treatment of textile wash-off wastewater, and treated liquor can be effectively recycled in next dyeing, without compromising quality parameters. This method proved to be an eco-friendly process owing to the fact that it did not use any fresh water. (author)

Crosslinking of epoxy-polysiloxane system by reactive blending

Czech Academy of Sciences Publication Activity Database

Gonzales, M.; Kadlec, Petr; Štěpánek, Petr; Strachota, Adam; Matějka, Libor

2004-01-01

Roč. 45, č. 16 (2004), s. 5533-5541 ISSN 0032-3861 R&D Projects: GA AV ČR IAA4050008 Keywords : reactive blending * siloxane network * epoxy network Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.433, year: 2004

Cue reactivity is associated with duration and severity of alcohol dependence: an FMRI study.

Directory of Open Access Journals (Sweden)

Zsuzsika Sjoerds

Full Text Available INTRODUCTION: With the progression of substance dependence, drug cue-related brain activation is thought to shift from motivational towards habit pathways. However, a direct association between cue-induced brain activation and dependence duration has not yet been shown. We therefore examined the relationship between alcohol cue-reactivity in the brain, cue-induced subjective craving and alcohol dependence duration and severity. Since alcohol dependence is highly comorbid with depression/anxiety, which may modulate brain responses to alcohol cues, we also examined the relation between comorbid depression/anxiety and cue-reactivity. METHODS: We compared 30 alcohol dependent patients with 15 healthy controls and 15 depression/anxiety patients during a visual alcohol cue-reactivity task using functional magnetic resonance imaging blood oxygenated level-dependent responses and subjective craving as outcomes. Within the alcohol dependent group we correlated cue-reactivity with alcohol dependence severity and duration, with cue-induced craving and with depression/anxiety levels. RESULTS: Alcohol dependent patients showed greater cue-reactivity in motivational brain pathways and stronger subjective craving than depression/anxiety patients and healthy controls. Depression/anxiety was not associated with cue-reactivity, but depression severity in alcohol dependent patients was positively associated with craving. Within alcohol dependence, longer duration of alcohol dependence was associated with stronger cue-related activation of the posterior putamen, a structure involved in habits, whereas higher alcohol dependence severity was associated with lower cue-reactivity in the anterior putamen, an area implicated in goal-directed behavior preceding habit formation. CONCLUSION: Cue-reactivity in alcohol dependence is not modulated by comorbid depression or anxiety. More importantly, the current data confirm the hypothesis of a ventral to dorsal striatal shift

Sources of variability of resting cerebral blood flow in healthy subjects

DEFF Research Database (Denmark)

Henriksen, Otto Mølby; Kruuse, Christina Rostrup; Olesen, Jes

2013-01-01

Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF...... measurements acquired in 152 healthy, young subjects using (133)Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity...... when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences...

Measurements and analyses on reactivity effects of absorber rods in a light-water moderated UO2 lattices

International Nuclear Information System (INIS)

Murakami, Kiyonobu; Miyoshi, Yoshinori; Hirose, Hideyuki; Suzaki, Takenori

1985-03-01

Reactivity effects and reactivity-interference effects of absorber rods were measured with a cylindrical core aiming to obtain bench-marks for verification of the calculational methods. The core consisted of 2.6 w/o enriched UO 2 fuel rods lattice of which water-to-fuel volume ratio was 1.83. In the experiment, the critical water levels were measured changing neutron absorber content of absorber rods and the distance between two absorber rods in the core center. Monte Calro codes KENO-IV and MULTI-KENO were used to calculate reactivity worthes of absorber rods. The calculational results of effective multiplication factors ranged from 0.978 to 0.999 for the 60 cases of critical cores with inserted absorber rods. The calculational results of absorber worthes agreed to the experimental results within twice of the standerd deviation accompanied with the Monte Calro calculation. (author)

Effect of 3-D moderator flow configurations on the reactivity of CANDU nuclear reactors

International Nuclear Information System (INIS)

Zadeh, Foad Mehdi; Etienne, Stephane; Chambon, Richard; Marleau, Guy; Teyssedou, Alberto

2017-01-01

Highlights: • 3-D CFD simulations of CANDU-6 moderator flows are presented. • A thermal-hydraulic code using thermal physical fluid properties is used. • The numerical approach and convergence is validated against available data. • Flow configurations are correlated using Richardson’s number. • The interaction between moderator temperatures with reactivity is determined. - Abstract: The reactivity of nuclear reactors can be affected by thermal conditions prevailing within the moderator. In CANDU reactors, the moderator and the coolant are mechanically separated but not necessarily thermally isolated. Hence, any variation of moderator flow properties may change the reactivity. Until now, nuclear reactor calculations have been performed by assuming uniform moderator flow temperature distribution. However, CFD simulations have predicted large time dependent flow fluctuations taking place inside the calandria, which can bring about local temperature variations that can exceed 50 °C. This paper presents robust CANDU 3-D CFD moderator simulations coupled to neutronic calculations. The proposed methodology makes it possible to study not only different moderator flow configurations but also their effects on the reactor reactivity coefficient.

Effects of a Context Shift and Multiple Context Extinction on Reactivity to Alcohol Cues

Science.gov (United States)

MacKillop, James; Lisman, Stephen A.

2008-01-01

Cue exposure treatment (CET) attempts to reduce the influence of conditioned substance cues on addictive behavior via prolonged cue exposure with response prevention (i.e., extinction), but has received only modest empirical support in clinical trials. This may be because extinction learning appears to be context dependent and a change in context may result in a return of conditioned responding (i.e., renewal), although this has received only limited empirical examination. The current study used a four-session laboratory analogue of CET to examine whether a change in context following three sessions of alcohol cue exposure with response prevention would result in renewal of conditioned responding. In addition, this study examined whether conducting extinction in multiple contexts would attenuate renewal of conditioned responding. In a one-way between-subjects design, 73 heavy drinkers (71% male) were randomized to three conditions: 1) single context extinction (extinction to alcohol cues in the same context for three sessions followed by a context shift at the fourth session); 2) multiple context extinction (extinction to alcohol cues in different contexts each day for all four sessions); and 3) pseudo-extinction control condition (exposure to neutral cues in the same context for three sessions followed by exposure to alcohol cues at the fourth session). The results revealed the predicted cue reactivity and extinction effects, but the hypotheses that a context shift would generate renewed cue reactivity and that multiple contexts would enhance extinction were not supported. Methodological aspects of the study and the need for parametric data on the context dependency of extinction to alcohol cues are discussed. PMID:18729687

Effects of Reactive Oxygen Species on Tubular Transport along the Nephron.

Science.gov (United States)

Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

2017-03-23

Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. Due to their high reactivity and potentially damaging effects to biomolecules, cells express a battery of enzymes to rapidly metabolize them to innocuous intermediaries. Initially, ROS were considered by biologists as dangerous byproducts of respiration capable of causing oxidative stress, a condition in which overproduction of ROS leads to a reduction in protective molecules and enzymes and consequent damage to lipids, proteins, and DNA. In fact, ROS are used by immune systems to kill virus and bacteria, causing inflammation and local tissue damage. Today, we know that the functions of ROS are not so limited, and that they also act as signaling molecules mediating processes as diverse as gene expression, mechanosensation, and epithelial transport. In the kidney, ROS such as nitric oxide (NO), superoxide (O₂ - ), and their derivative molecules hydrogen peroxide (H₂O₂) and peroxynitrite (ONO₂ - ) regulate solute and water reabsorption, which is vital to maintain electrolyte homeostasis and extracellular fluid volume. This article reviews the effects of NO, O₂ - , ONO₂ - , and H₂O₂ on water and electrolyte reabsorption in proximal tubules, thick ascending limbs, and collecting ducts, and the effects of NO and O₂ - in the macula densa on tubuloglomerular feedback.

Effects of Metformin on Tissue Oxidative and Dicarbonyl Stress in Transgenic Spontaneously Hypertensive Rats Expressing Human C-Reactive Protein

Czech Academy of Sciences Publication Activity Database

Malínská, H.; Oliyarnyk, O.; Škop, V.; Šilhavý, Jan; Landa, Vladimír; Zídek, Václav; Mlejnek, Petr; Šimáková, Miroslava; Strnad, Hynek; Kazdová, L.; Pravenec, Michal

2016-01-01

Roč. 11, č. 3 (2016), e0150924 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LL1204; GA MZd(CZ) NT14325 Institutional support: RVO:67985823 ; RVO:68378050 Keywords : inflammation * spontaneously hypertensive rat * transgenic * C-reactive protein * dicarbonyl stress * metformin Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 2.806, year: 2016

Sb(V reactivity with human blood components: redox effects.

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Silvana López

Full Text Available We assessed the reactivity of Sb(V in human blood. Sb(V reactivity was determined using an HPLC-HG-AFS hyphenated system. Sb(V was partially reduced to Sb(III in blood incubation experiments; however, Sb(III was a highly unstable species. The addition of 0.1 mol L(-1 EDTA prevented Sb(III oxidation, thus enabling the detection of the reduction of Sb(V to Sb(III. The transformation of Sb(V to Sb(III in human whole blood was assessed because the reduction of Sb(V in human blood may likely generate redox side effects. Our results indicate that glutathione was the reducing agent in this reaction and that Sb(V significantly decreased the GSH/GSSG ratio from 0.32 ± 0.09 to 0.07 ± 0.03. Moreover, the presence of 200 ng mL(-1 of Sb(V increased the activity of superoxide dismutase from 4.4 ± 0.1 to 7.0 ± 0.4 U mL(-1 and decreased the activity of glutathione peroxidase from 62 ± 1 to 34 ± 2 nmol min(-1 mL(-1.

The effects of racial stressors and hostility on cardiovascular reactivity in African American and Caucasian men.

Science.gov (United States)

Fang, C Y; Myers, H F

2001-01-01

This study examined the effects of race-related stressors and hostility on cardiovascular reactivity in 31 African American and 31 Caucasian men. Participants viewed 3 film excerpts that depicted neutral, anger-provoking (but race-neutral), and racist situations. Participants exhibited significantly greater diastolic blood pressure reactivity to anger-provoking and racist stimuli compared with neutral stimuli. In addition, high hostility was associated with higher recovery systolic and diastolic blood pressure levels after exposure to the films. Although the results failed to confirm previous reports of greater reactivity to racism in African Americans, the findings suggest that diastolic blood pressure levels may remain elevated after exposure to racist stimuli. These results indicate that even indirect exposure to interpersonal conflict elicits significant reactivity, which can persist after exposure to the stressor, especially among high-hostile men.

Simulation of reactive geochemical transport in groundwater using a semi-analytical screening model

Science.gov (United States)

McNab, Walt W.

1997-10-01

A reactive geochemical transport model, based on a semi-analytical solution to the advective-dispersive transport equation in two dimensions, is developed as a screening tool for evaluating the impact of reactive contaminants on aquifer hydrogeochemistry. Because the model utilizes an analytical solution to the transport equation, it is less computationally intensive than models based on numerical transport schemes, is faster, and it is not subject to numerical dispersion effects. Although the assumptions used to construct the model preclude consideration of reactions between the aqueous and solid phases, thermodynamic mineral saturation indices are calculated to provide qualitative insight into such reactions. Test problems involving acid mine drainage and hydrocarbon biodegradation signatures illustrate the utility of the model in simulating essential hydrogeochemical phenomena.

Emotional reactivity across the adult life span: the cognitive pragmatics make a difference.

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Kunzmann, Ute; Richter, David

2009-12-01

Previously, we found that during films about age-typical losses, older adults experienced greater sadness than young adults, whereas their physiological responses were just as large. In the present study, our goal was to replicate this finding and extend past work by examining the role of cognitive functioning in age differences in emotional reactivity. We measured the autonomic and subjective responses of 240 adults (age range=20 to 70) while they viewed films about age-typical losses from our previous work. Findings were fully supportive of our past work: The magnitude of subjective reactions to our films increased linearly over the adult years, whereas there were no age differences on the level of physiological reactivity. We also found that the subjective reactions of adults with high pragmatic intelligence were of moderate size independent of their own age or the age relevance of the emotion elicitor. In contrast, the subjective reactions of adults low on pragmatic intelligence were more variable. Together, this evidence suggests that research on age differences in emotional reactivity may benefit from a perspective that considers individual difference variables as well as contextual variations. PsycINFO Database Record Copyright (c) 2009 APA, all rights reserved

Virtual Reality Cue Reactivity Assessment: A Comparison of Treatment- vs. Nontreatment-Seeking Smokers

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Bordnick, Patrick S.; Yoon, Jin H.; Kaganoff, Eili; Carter, Brian

2013-01-01

Objectives: The cue-reactivity paradigm has been widely used to assess craving among cigarette smokers. Seeking to replicate and expand on previous virtual reality (VR) nicotine cue-reactivity research on nontreatment-seeking smokers, the current study compared subjective reports of craving for cigarettes when exposed to smoking (proximal and…

The Effects of Training Contingency Awareness During Attention Bias Modification on Learning and Stress Reactivity.

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Lazarov, Amit; Abend, Rany; Seidner, Shiran; Pine, Daniel S; Bar-Haim, Yair

2017-09-01

Current attention bias modification (ABM) procedures are designed to implicitly train attention away from threatening stimuli with the hope of reducing stress reactivity and anxiety symptoms. However, the mechanisms underlying effective ABM delivery are not well understood, with awareness of the training contingency suggested as one possible factor contributing to ABM efficacy. Here, 45 high-anxious participants were trained to divert attention away from threat in two ABM sessions. They were randomly assigned to one of three training protocols: an implicit protocol, comprising two standard implicit ABM training sessions; an explicit protocol, comprising two sessions with explicit instruction as to the attention training contingency; and an implicit-explicit protocol, in which participants were not informed of the training contingency in the first ABM session and informed of it at the start of the second session. We examined learning processes and stress reactivity following a stress-induction task. Results indicate that relative to implicit instructions, explicit instructions led to stronger learning during the first training session. Following rest, the explicit and implicit groups exhibited consolidation-related improvement in performance, whereas no such improvement was noted for the implicit-explicit group. Finally, although stress reactivity was reduced after training, contingency awareness did not yield a differential effect on stress reactivity measured using both self-reports and skin conductance, within and across sessions. These results suggest that explicit ABM administration leads to greater initial learning during the training protocol while not differing from standard implicit administration in terms of off-line learning and stress reactivity. Copyright © 2017. Published by Elsevier Ltd.

Serological Reactivity and Identification of Immunoglobulin E-Binding Polypeptides of Ganoderma applanatum Crude Spore Cytoplasmic Extract in Puerto Rican Subjects.

Science.gov (United States)

Vilá-Héreter, Frances; Rivera-Mariani, Félix E; Bolaños-Rosero, Benjamín

2017-01-01

The allergenic potential of Ganoderma applanatum basidiospores has been demonstrated previously in Puerto Rico. However, basidiomycete allergens are not available for inclusion in allergy diagnostic panels. Therefore, we sought to confirm allergic sensitization to G. applanatum crude spore cytoplasmic extract through reactivity in serological assays and detection of immunoglobulin E (IgE)-binding polypeptides. Via an indirect ELISA, serological reactivity was compared between groups of individuals with different allergic profiles. Group 1 (n = 51) consisted of individuals with sIgE to the allergens included in the diagnostic panels; group 2 (n = 14) comprised individuals with no sIgE to the allergens tested; and group 3 (n = 22) included individuals with no allergic history. To visualize IgE-binding polypeptides, group 1 sera were examined via Western blotting (WB). Polypeptide bands with the highest reactivity were analyzed by mass spectrometry (MS) for putative identification. The serological reactivity of group 1 was significantly higher than that of group 3 in an indirect ELISA (p = 0.03). Sixty-five percent of group 1 individuals showed reactivity to polypeptide bands in WB. Bands of 81 and 56 kDa had the highest reactivity proportions among the reactive sera, followed by a 45-kDa band. MS analysis of these 3 polypeptides suggests that they are basidiomycete-derived enzymes with aconitate hydratase, catalase, and enolase functions. G. applanatum spores have allergenic components recognized by Puerto Rican individuals, which could eventually be considered as markers in cases of fungal allergy and be included in diagnostic allergen panels in Puerto Rico and tropical regions. © 2017 S. Karger AG, Basel.

Neighborhood disadvantage and adolescent stress reactivity

Directory of Open Access Journals (Sweden)

Daniel A. Hackman

2012-10-01

Full Text Available Lower socioeconomic status (SES is associated with higher levels of life stress, which in turn affect stress physiology. SES is related to basal cortisol and diurnal change, but it is not clear if SES is associated with cortisol reactivity to stress. To address this question, we examined the relationship between two indices of SES, parental education and concentrated neighborhood disadvantage, and the cortisol reactivity of African-American adolescents to a modified version of the Trier Social Stress Test. We found that concentrated disadvantage was associated with cortisol reactivity and this relationship was moderated by gender, such that higher concentrated disadvantage predicted higher cortisol reactivity and steeper recovery in boys but not in girls. Parental education, alone or as moderated by gender, did not predict reactivity or recovery, while neither education nor concentrated disadvantage predicted estimates of baseline cortisol. This finding is consistent with animal literature showing differential vulnerability, by gender, to the effects of adverse early experience on stress regulation and the differential effects of neighborhood disadvantage in adolescent males and females. This suggests that the mechanisms underlying SES differences in brain development and particularly reactivity to environmental stressors may vary across genders.

The reactivity meter and core reactivity

International Nuclear Information System (INIS)

Siltanen, P.

1999-01-01

This paper discussed in depth the point kinetic equations and the characteristics of the point kinetic reactivity meter, particularly for large negative reactivities. From a given input signal representing the neutron flux seen by a detector, the meter computes a value of reactivity in dollars (ρ/β), based on inverse point kinetics. The prompt jump point of view is emphasised. (Author)

Positive void reactivity

International Nuclear Information System (INIS)

Diamond, D.J.

1992-09-01

This report is a review of some of the important aspects of the analysis of large loss-of-coolant accidents (LOCAs). One important aspect is the calculation of positive void reactivity. To study this subject the lattice physics codes used for void worth calculations and the coupled neutronic and thermal-hydraulic codes used for the transient analysis are reviewed. Also reviewed are the measurements used to help validate the codes. The application of these codes to large LOCAs is studied with attention focused on the uncertainty factor for the void worth used to bias the results. Another aspect of the subject dealt with in the report is the acceptance criteria that are applied. This includes the criterion for peak fuel enthalpy and the question of whether prompt criticality should also be a criterion. To study the former, fuel behavior measurements and calculations are reviewed. (Author) (49 refs., 2 figs., tab.)

Object attraction effects during subject-verb agreement in Persian.

Science.gov (United States)

Feiz, Aazam; Cowles, Wind

2018-04-01

Subject-verb agreement provides insight into how grammatical and semantic features interact during sentence production, and prior studies have found attraction errors when an intervening local noun is grammatically part of the subject. Two major types of theories have emerged from these studies: control based and competition-based. The current study used an subject-object-verb language with optional subject-verb agreement, Persian, to test the competition-based hypothesis that intervening object nouns may also cause attraction effects, even though objects are not part of the syntactic relationship between the subject and verb. Our results, which did not require speakers to make grammatical errors, show that objects can be attractors for agreement, but this effect appears to be dependent on the type of plural marker on the object. These results support competition-based theories of agreement production, in which agreement may be influenced by attractors that are outside the scope of the subject-verb relationship.

Grass-specific CD4+ T-cells exhibit varying degrees of cross-reactivity, implications for allergen-specific immunotherapy

Science.gov (United States)

Archila, LD; DeLong, JH; Wambre, E; James, EA; Robinson, DM; Kwok, WW

2014-01-01

Background Conceptually, allergic responses may involve cross-reactivity by antibodies or T-cells. While IgE cross-reactivity amongst grass pollen allergens has been observed, cross-reactivity at the allergen-specific T-cell level has been less documented. Identification of the patterns of cross-reactivity may improve our understanding, allowing optimization of better immunotherapy strategies. Objectives We use Phleum pratense as model for the studying of cross-reactivity at the allergen-specific CD4+ T cell level amongst DR04:01 restricted Pooideae grass pollen T-cell epitopes. Methods After In vitro culture of blood mononucleated cells from Grass-pollen allergic subjects with specific Pooideae antigenic epitopes, dual tetramer staining with APC-labeled DR04:01/Phleum pratense tetramers and PE-labeled DR04:01/Pooideae grass homolog tetramers was assessed to identify cross-reactivity amongst allergen-specific DR04:01-restricted T-cells in 6 subjects. Direct ex vivo staining enabled the comparison of frequency and phenotype of different Pooideae grass pollen reactive T-cells. Intracellular cytokine staining (ICS) assays were also used to examine phenotypes of these T-cells. Results T-cells with various degree of cross reactive profiles could be detected. Poa p 1 97-116, Lol p 1 221-240, Lol p 5a 199-218, and Poa p 5a 199-218 were identified as minimally-cross-reactive T-cell epitopes that do not show cross reactivity to Phl p 1 and Phl p 5a epitopes. Ex vivo tetramer staining assays demonstrated T-cells that recognized these minimally-cross reactive T-cell epitopes are present in Grass-pollen allergic subjects. Conclusions Our results suggest that not all Pooideae grass epitopes with sequence homology are cross-reactive. Non-cross reactive T-cells with comparable frequency, phenotype and functionality to Phl p-specific T-cells, suggest that a multiple allergen system should be considered for immunotherapy instead of a mono allergen system. PMID:24708411

Grass-specific CD4(+) T-cells exhibit varying degrees of cross-reactivity, implications for allergen-specific immunotherapy.

Science.gov (United States)

Archila, L D; DeLong, J H; Wambre, E; James, E A; Robinson, D M; Kwok, W W

2014-07-01

Conceptually, allergic responses may involve cross-reactivity by antibodies or T-cells. While IgE cross-reactivity among grass-pollen allergens has been observed, cross-reactivity at the allergen-specific T-cell level has been less documented. Identification of the patterns of cross-reactivity may improve our understanding, allowing optimization of better immunotherapy strategies. We use Phleum pratense as model for the studying of cross-reactivity at the allergen-specific CD4(+) T cell level among DR04:01 restricted Pooideae grass-pollen T-cell epitopes. After in vitro culture of blood mono-nucleated cells from grass-pollen-allergic subjects with specific Pooideae antigenic epitopes, dual tetramer staining with APC-labelled DR04:01/Phleum pratense tetramers and PE-labelled DR04:01/Pooideae grass homolog tetramers was assessed to identify cross-reactivity among allergen-specific DR04:01-restricted T-cells in six subjects. Direct ex vivo staining enabled the comparison of frequency and phenotype of different Pooideae grass-pollen reactive T-cells. Intracellular cytokine staining (ICS) assays were also used to examine phenotypes of these T-cells. T-cells with various degrees of cross-reactive profiles could be detected. Poa p 1 97-116 , Lol p 1 221-240 , Lol p 5a 199-218 , and Poa p 5a 199-218 were identified as minimally cross-reactive T-cell epitopes that do not show cross-reactivity to Phl p 1 and Phl p 5a epitopes. Ex vivo tetramer staining assays demonstrated T-cells that recognized these minimally cross-reactive T-cell epitopes are present in Grass-pollen-allergic subjects. Our results suggest that not all Pooideae grass epitopes with sequence homology are cross-reactive. Non-cross-reactive T-cells with comparable frequency, phenotype and functionality to Phl p-specific T-cells suggest that a multiple allergen system should be considered for immunotherapy instead of a mono-allergen system. © 2014 John Wiley & Sons Ltd.

Effect of Daytime Exercise on Sleep Eeg and Subjective Sleep

Science.gov (United States)

Sasazawa, Y.; Kawada, T.; Kiryu, Y.

1997-08-01

This study was designed to assess the effects of daytime physical exercise on the quality of objective and subjective sleep by examining all-night sleep EEGs. The subjects were five male students, aged 19 to 20 years, who were in the habit of performing regular daytime exercise. The sleep polygraphic parameters in this study were sleep stage time as a percentage of total sleep time (%S1, %S2, %S(3+4), %SREM, %MT), time in bed (TIB), sleep time (ST), total sleep time (TST), sleep onset latency (SOL), waking from sleep, sleep efficiency, number of awakenings, number of stage shifts, number of spindles, and percentages of α and δ waves, all of which were determined by an automatic computer analysis system. The OSA questionnaire was used to investigate subjective sleep. The five scales of the OSA used were sleepiness, sleep maintenance, worry, integrated sleep feeling, and sleep initiation. Each sleep parameter was compared in the exercise and the non-exercise groups. Two-way analysis of variance was applied using subject factor and exercise factor. The main effect of the subject was significant in all parameters and the main effect of exercise in %S(3+4), SOL and sleep efficiency, among the objective sleep parameters. The main effects of the subject, except sleepiness, were significant, as was the main effect of exercise on sleep initiation, among the subjective sleep parameters. These findings suggest that daytime exercise shortened sleep latency and prolonged slow-wave sleep, and that the subjects fell asleep more easily on exercise days. There were also significant individual differences in both the objective and subjective sleep parameters.

Association between stress-related sleep reactivity and cognitive processes in insomnia disorder and insomnia subgroups: preliminary results.

Science.gov (United States)

Palagini, Laura; Faraguna, Ugo; Mauri, Mauro; Gronchi, Alessia; Morin, Charles M; Riemann, Dieter

2016-03-01

Stress-related sleep reactivity, sleep-related cognitions, and psychological factors play an important role in insomnia. The aim was to investigate their possible association in Insomnia Disorder, insomnia subgroups, and healthy subjects. The cross-sectional study consisted of 93 subjects who met diagnostic criteria for Insomnia Disorder according to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) and of 30 healthy subjects. Survey instruments included the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Ford Insomnia Response to Stress Test (FIRST), Dysfunctional Beliefs about Sleep scale (DBAS), Beck Depression Inventory (BDI), and Zung Self-Rating Anxiety Scale (SAS). Descriptive statistics, Pearson correlations, χ(2)-test, and multiple linear regression were performed. FIRST and SAS best determined the insomnia subjects vs good sleepers (FIRST χ(2) = 109.6, p insomnia, stress-related sleep reactivity, and psychological factors, such as anxiety symptoms, may distinguish insomnia subjects from good sleepers; (2) sleep reactivity and sleep-related cognitions seem interrelated, unhelpful beliefs may affect the stress reactivity; (3) psychological factors may influence sleep quality and the severity of insomnia; (4) these important sleep-related variables may have similar associations in insomnia subgroups; they may constitute the core factors for insomnia development and maintenance. Copyright © 2015 Elsevier B.V. All rights reserved.

Vascular Reactivity and Salt Sensitivity in Normotensive and ...

African Journals Online (AJOL)

system activation (Everson, 2001). Cardiovascular reactivity ... personality factors and emotion (Everson, 2001). Race is equally ... cardiovascular or sympathetic nerve function. Subjects ..... a low sodium diet. The present study is also important in that identifying ... project on genetic basis of hypertension and renal. Epithelial ...

Poor habitual sleep efficiency is associated with increased cardiovascular and cortisol stress reactivity in men.

Science.gov (United States)

Massar, Stijn A A; Liu, Jean C J; Mohammad, Nabilah B; Chee, Michael W L

2017-07-01

Inadequate sleep and psychological stress can both elevate physiological stress markers, such as cortisol. Prior studies that have applied induced psychosocial stress after a night of experimental sleep deprivation have found these effects to be compounded. We examined whether the relationship between stress reactivity and poor sleep also extends to habitual sleep patterns. Fifty-nine adult male participants were recruited. Habitual sleep patterns were monitored with actigraphy for a week. Participants subsequently underwent the Trier Social Stress Test. Cardiovascular responses and salivary cortisol were measured at baseline, during stress, and during recovery. Subjects who showed poor habitual sleep efficiency during the week before stress induction responded with higher stress-related elevations of blood pressure and cortisol levels as compared to subjects with high sleep efficiency. This relationship between poor sleep efficiency and elevated blood pressure persisted during the post-stress recovery period. Similar associations between total sleep time in the week prior to the stress induction and physiological reactivity did not reach significance. Our findings indicate that habitual low sleep efficiency exaggerates cardiovascular and neuroendocrine effects of psychosocial stress, in a male population. Copyright © 2017 Elsevier Ltd. All rights reserved.

The mediating effect of mindful non-reactivity in exposure-based cognitive behavior therapy for severe health anxiety.

Science.gov (United States)

Hedman, Erik; Hesser, Hugo; Andersson, Erik; Axelsson, Erland; Ljótsson, Brjánn

2017-08-01

Exposure-based cognitive behavior therapy (CBT) has been shown to be effective in the treatment of severe health anxiety, but little is known about mediators of treatment effect. The aim of the present study was to investigate mindful non-reactivity as a putative mediator of health anxiety outcome using data from a large scale randomized controlled trial. We assessed mindful non-reactivity using the Five Facets Mindfulness Questionnaire-Non-Reactivity scale (FFMQ-NR) and health anxiety with the Short Health Anxiety Inventory (SHAI). Participants with severe health anxiety (N=158) were randomized to internet-delivered exposure-based CBT or behavioral stress management (BSM) and throughout the treatment, both the mediator and outcome were measured weekly. As previously reported, exposure-based CBT was more effective than BSM in reducing health anxiety. In the present study, latent process growth modeling showed that treatment condition had a significant effect on the FFMQ-NR growth trajectory (α-path), estimate=0.18, 95% CI [0.04, 0.32], p=.015, indicating a larger increase in mindful non-reactivity among participants receiving exposure-based CBT compared to the BSM group. The FFMQ-NR growth trajectory was significantly correlated with the SHAI trajectory (β-path estimate=-1.82, 95% CI [-2.15, -1.48], panxiety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of packing fraction variations on reactivity in pebble-bed reactor

International Nuclear Information System (INIS)

Snoj, L.; Ravnik, M.

2004-01-01

The pebble-bed reactor (PBR) core consists of large number of randomly packed spherical fuel elements. The effect of fuel element packing density variations on multiplication factor in a typical PBR is studied using WIMS code. It is observed that at normal conditions the k-eff increases with packing fraction. Effects of secondary coolant ingress (water or molten lead) in the core at accidental conditions are studied at various packing densities. The effect of water ingress on reactivity depends strongly on water density and packing fraction and is prevailingly positive, while the lead ingress reduces multiplication factor regardless of lead effective density and packing fraction. Both effects are stronger at lower packing fractions. (author)

Method for reactivating solid catalysts used in alkylation reactions

Science.gov (United States)

Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

2003-06-17

A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

Effects of D-cycloserine on extinction of mesolimbic cue reactivity in alcoholism: a randomized placebo-controlled trial.

Science.gov (United States)

Kiefer, Falk; Kirsch, Martina; Bach, Patrick; Hoffmann, Sabine; Reinhard, Iris; Jorde, Anne; von der Goltz, Christoph; Spanagel, Rainer; Mann, Karl; Loeber, Sabine; Vollstädt-Klein, Sabine

2015-07-01

Mesocorticolimbic reactivity to alcohol-associated cues has been shown to be associated with relapse to renewed drinking and to be decreased by cue-exposure-based extinction training (CET). Evidence from preclinical studies suggests that the extinction of conditioned alcohol-seeking behavior might be facilitated by drugs increasing N-methyl-D-aspartate (NMDA) receptor-associated memory consolidation. In this study, we assessed the efficacy of CET treatment supplemented with the partial NMDA-receptor agonist D-cycloserine (DCS) at reducing mesolimbic cue reactivity (CR), craving, and relapse risk in alcoholism. In a randomized, placebo-controlled, double-blind study, we recruited 76 recently detoxified abstinent alcohol-dependent patients. Thirty-two (16 DCS, 16 placebo) patients showed cue-induced ventral-striatal activation measured with functional magnetic resonance imaging (fMRI) prior to treatment and were thus included in the efficacy analyses. After inpatient detoxification, patients underwent nine sessions of CET spaced over 3 weeks, receiving either 50 mg DCS or placebo 1 h prior to each CET session. FMRI was conducted before treatment and 3 weeks after treatment onset. Following treatment with CET plus DCS, cue-induced brain activation in the ventral and dorsal striatum was decreased compared to treatment with CET plus placebo. Elevated posttreatment ventral striatal CR and increased craving (assessed using the Obsessive Compulsive Drinking Scale) were associated with increased relapse risk. DCS was shown to augment the effect of CET for alcohol-dependent subjects. The interaction between craving and ventral-striatal CR on treatment outcome suggests that CET might be especially effective in patients exhibiting both high craving and elevated CR.

Ginseng and Ginkgo Biloba Effects on Cognition as Modulated by Cardiovascular Reactivity: A Randomised Trial.

Directory of Open Access Journals (Sweden)

Derek Ong Lai Teik

Full Text Available There is some evidence to suggest that ginseng and Ginkgo biloba can improve cognitive performance, however, very little is known about the mechanisms associated with such improvement. Here, we tested whether cardiovascular reactivity to a task is associated with cognitive improvement.Using a double-blind, placebo controlled, crossover design, participants (N = 24 received two doses of Panax Ginseng (500, 1000 mg or Ginkgo Biloba (120, 240 mg (N = 24, and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline to cognitive tasks. This effect (reversal was most notable after those tasks (Stroop and Iowa that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo blunted response (i.e. decrease or no change from baseline to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement.ClinicalTrials.gov NCT02386852.

Effect of periodontal therapy on serum C-reactive protein levels in patients with gingivitis and chronic periodontitis: a clinicobiochemical study.

Science.gov (United States)

Patil, Veena A; Desai, Manthan H

2013-03-01

The aim of the present study was to evaluate the effect of periodontal therapy on serum C-reactive protein (CRP) levels in patients with gingivitis and chronic periodontitis. A total of 60 subjects (30 males and 30 females) were included in the study with 20 subjects in each of the groups classified based on community periodontal index (CPI) scores: I: Healthy, II: Gingivitis, III: Mild periodontitis. Periodontal therapy was performed on groups II and III patients. Venous blood was collected from each subject at baseline and 3 months after periodontal therapy. The collected sample was subjected to biochemical analysis to detect CRP levels by using immunoturbidimetric method. The present study demonstrated that the periodontitis group had a higher mean CRP levels (2.49 ± 0.47 ng/ml) as compared to the gingivitis group (1.40 ± 0.32 ng/ml) and healthy group (0.56 ± 0.20 ng/ml). The mean CRP values after periodontal therapy were found to be reduced to 0.44 ± 0.23 ng/ml in group II and 1.30 ± 0.36 ng/ml in group III patients. Within the limitations of this study, it can be concluded that CRP level progressively increases from periodontal health to disease. A decrease in CRP levels with periodontal treatment was also observed. Due to its opsonizing abilities CRP plays an important role in the innate host defence. It can be hypothesized that CRP is a potential biomarker of periodontal disease. A number of studies have reported elevated serum CRP levels in periodontitis subjects. Long standing periodontal disease and raised CRP levels enhance the risk of cardiovascular disease, cerebrovascular accidents and preterm low birth weight infants. There is also evidence that effective periodontal therapy can lower serum CRP levels. However, the data of interventional studies on CRP in gingivitis and periodontitis is scarce.

Effect of heavy metals ondecolorization of reactive brilliant red by newly isolated microorganisms

International Nuclear Information System (INIS)

Nosheen, S.; Arshad, M.

2011-01-01

This study involves aerobic decolorisation of reactive azo dye reactive brilliant red 2KBP by newly isolated microbial strains (two bacterial and one fungal strain) in presence of heavy metals including cobalt chloride, ferric chloride, zinc sulphate, copper sulphate and nickel chloride. Many heavy metals are necessary for microbial growth and are required in very small amounts however at higher levels they become toxic. So was the objective of present work to check the effect of concentration of heavy metals on the potential of microbial strains to decolorize azo dyes. All the heavy metals under consideration were added in range of 0.5 gl-1-2.5gl/sup -1/. All heavy metals showed inhibitory effect on decolorization capacity of bacterial as well as fungal strain .At optimum conditions bacterial strains named as B1 and B2 removed 84% and 78% while fungal strain decolorized 90.4% of dye. Cobalt and nickel showed greater inhibitors on% decolorization of dyes than Zinc and iron. Fungal strain showed greater negative effect. Heavy metals might affect enzyme activities and thus reducing removal of dye. (author)

Cerebrovascular CO2 reactivity in normotensive and hypertensive man

DEFF Research Database (Denmark)

Tominaga, S; Strandgaard, S; Uemura, K

1976-01-01

Cerebrovascular reactivity to CO2 inhalation and voluntary hyperventilation was studied in seven normotensive subjects and nine hypertensive patients without clinical or angiographical signs of arteriosclerosis. Cerebral blood flow (CBF) was measured by the intracarotid 133Xe clearance method...... and calculated as the initial slope index. Three to five CBF measurements were made in each patient in the PaCO2 range of 20 to 55 mm Hg. No difference was observed in reactivity between hypertensive and normotensive patients, either during CO2 inhalation or during hyperventilation. The shape of the CBF:PaCO2...... curve suggested a decrease in reactivity below a PaCO2 of 30 to 35 mm Hg in both groups. Above a PaCO2 of 35 mm Hg, exponential regression analysis yielded a mean reactivity of 6 +/- 2%, whereas below a PaCO2 of 30 mm Hg it was about 2%. The rise in CBF during CO2 inhalation was not influenced...

Effective Proactive and Reactive Defense Strategies against Malicious Attacks in a Virtualized Honeynet

Directory of Open Access Journals (Sweden)

Frank Yeong-Sung Lin

2013-01-01

Full Text Available Virtualization plays an important role in the recent trend of cloud computing. It allows the administrator to manage and allocate hardware resources flexibly. However, it also causes some security issues. This is a critical problem for service providers, who simultaneously strive to defend against malicious attackers while providing legitimate users with high quality service. In this paper, the attack-defense scenario is formulated as a mathematical model where the defender applies both proactive and reactive defense mechanisms against attackers with different attack strategies. In order to simulate real-world conditions, the attackers are assumed to have incomplete information and imperfect knowledge of the target network. This raises the difficulty of solving the model greatly, by turning the problem nondeterministic. After examining the experiment results, effective proactive and reactive defense strategies are proposed. This paper finds that a proactive defense strategy is suitable for dealing with aggressive attackers under “winner takes all” circumstances, while a reactive defense strategy works better in defending against less aggressive attackers under “fight to win or die” circumstances.

Geochemical reactivity of rocks of the Czech Republic

Czech Academy of Sciences Publication Activity Database

Chuman, T.; Gürtlerová, P.; Hruška, Jakub; Adamová, M.

2014-01-01

Roč. 10, č. 2 (2014), s. 341-349 ISSN 1744-5647 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : geochemical reactivity * Czech Republic * susceptibility to weathering Subject RIV: EH - Ecology, Behaviour Impact factor: 1.193, year: 2014

Possibilities of achieving non-positive void reactivity effect in fast sodium-cooled reactors with increased self-protection

International Nuclear Information System (INIS)

Alekseev, P.N.; Zverkov, Yu.A.; Morozov, A.G.; Orlov, V.V.; Slesarev, I.S.; Subbotin, S.A.

1989-01-01

The problems of self-protection inhancement for the liquid-metal cooled fast reactors with intra-assembly heterogeneity of the core are studied. Possible approaches to arrangement of such reactors with various powers characterized by high levels of coolant natural circulation, minimum reactivity changes during fuel burn-up and non-positive void effect of reactivity are found. 10 refs.; 11 figs

Reactive Laser-induced Ablation as Approach to Titanium Oxycarbide Films

Czech Academy of Sciences Publication Activity Database

Jandová, Věra; Fajgar, Radek; Dytrych, Pavel; Koštejn, Martin; Dřínek, Vladislav; Kupčík, Jaroslav

2015-01-01

Roč. 590, SEP 1 (2015), s. 270-275 ISSN 0040-6090 Institutional support: RVO:67985858 Keywords : IR laser * reactive ablation * titanium ethoxide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.761, year: 2015

Central insulin administration improves odor-cued reactivation of spatial memory in young men.

Science.gov (United States)

Brünner, Yvonne F; Kofoet, Anja; Benedict, Christian; Freiherr, Jessica

2015-01-01

Insulin receptors are ubiquitously found in the human brain, comprising the olfactory bulb, essential for odor processing, and the hippocampus, important for spatial memory processing. The present study aimed at examining if intranasal insulin, which is known to transiently increase brain insulin levels in humans, would improve odor-cued reactivation of spatial memory in young men. We applied a double-blind, placebo-controlled, counterbalanced within-subject design. The study was conducted at the research unit of a university hospital. Interventions/Participants/Main Outcome Measures: Following intranasal administration of either insulin (40 I.U.) or placebo, male subjects (n = 18) were exposed to eight odors. During each odor exposure, a green-colored field was presented on a 17-in. computer screen. During immediate recall (comprising 3 runs), the participants were re-exposed to each odor cue, and were asked to select the corresponding field (with visual feedback after each response). The delayed recall was scheduled ∼10 min later (without feedback). To test if insulin's putative effect on odor-place memory would be domain-specific, participants also performed a separate place and odor recognition task. Intranasal insulin improved the delayed but not immediate odor-cued recall of spatial memory. This effect was independent of odor type and in the absence of systemic side effects (eg, fasting plasma glucose levels remained unaltered). Place and odor recognition were unaffected by the insulin treatment. These findings suggest that acute intranasal insulin improves odor-cued reactivation of spatial memory in young men.

Comparative study of C-Reactive Protein and other biochemical ...

African Journals Online (AJOL)

Serum levels of C-reactive proteins (CRP), Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total protein, albumin and globulins were investigated using high sensitivity Immunoturbidometric and colorimetric techniques in individuals with hepatitis (n=50), Malaria (n=50) and 40 control subjects in age ...

Definition of reactivity and its measurability

International Nuclear Information System (INIS)

Hu Dapu

1986-01-01

Reactivity is the fundamental and important physical quantity in the reactor physics. The different kinds of method for defining reactivity are represented, the difference between different definitions of reactivity is indicalted and the conditions under which they have nearly the same measurable value are discussed. It is demonstrated that when the static adjointed neutron density or the neutron importance is selected to be a weight function for generating kinetic parameters used in the neutron kinetic equations, the kinetic reactivity is approximately equal to the static reactivity. Due to the constraint of the normalization condition, the shape function must be so selected that the corresponding amplitude function is proportional to the fundamental mode of neutron density variating with time. Measured reactivity by the kinetic method may vary with the position of detector, owing to the different space distribution of the prompt neutrons density and the delayed neutrons density and the effect of the higher harmonics of the neutron density. Some corresponding correction must be made in order to obtain the real static reactivity

The BDNF Val66Met polymorphism affects HPA-axis reactivity to acute stress.

Science.gov (United States)

Alexander, Nina; Osinsky, Roman; Schmitz, Anja; Mueller, Eva; Kuepper, Yvonne; Hennig, Juergen

2010-07-01

Growing evidence suggests that individual differences in HPA-axis reactivity to psychosocial stress are partly due to heritable influences. However, knowledge about the role of specific genetic variants remains very limited to date. Since brain-derived neurotrophic factor (BDNF) not only exhibits neurotrophic actions but is also involved in the regulation of hypothalamic neuropeptides, we investigated the role of a common functional polymorphism within the BDNF gene (BDNF Val66Met) in the context of endocrine and cardiovascular stress reactivity. Healthy male adults (N=100) were genotyped and exposed to a standardized laboratory stress task (Public Speaking). Saliva cortisol and self-reported mood levels were obtained at 6 time points prior to the stressor and during an extended recovery period. Furthermore, heart rate reactivity as an indicator of sympathetic activation was monitored continuously during the experimental procedure. We report a small, but significant effect of the BDNF Val66Met polymorphism on stress reactivity. More precisely, carriers of the met-allele showed a significantly attenuated HPA-axis and cardiovascular reactivity to the psychosocial stressor compared to subjects with the val/val genotype. Furthermore, the diminished physiological response in met-allele carriers was also attended by significantly lower self-reported ratings of perceived stress and nervousness. Our findings of a diminished endocrine and cardiovascular stress response in healthy male adults is consistent with a previously published study and adds further evidence for a crucial role of the BDNF Val66Met polymorphism in the modulation of stress reactivity. Copyright 2010. Published by Elsevier Ltd.

Frictional and hydraulic behaviour of carbonate fault gouge during fault reactivation - An experimental study

Science.gov (United States)

Delle Piane, Claudio; Giwelli, Ausama; Clennell, M. Ben; Esteban, Lionel; Nogueira Kiewiet, Melissa Cristina D.; Kiewiet, Leigh; Kager, Shane; Raimon, John

2016-10-01

We present a novel experimental approach devised to test the hydro-mechanical behaviour of different structural elements of carbonate fault rocks during experimental re-activation. Experimentally faulted core plugs were subject to triaxial tests under water saturated conditions simulating depletion processes in reservoirs. Different fault zone structural elements were created by shearing initially intact travertine blocks (nominal size: 240 × 110 × 150 mm) to a maximum displacement of 20 and 120 mm under different normal stresses. Meso-and microstructural features of these sample and the thickness to displacement ratio characteristics of their deformation zones allowed to classify them as experimentally created damage zones (displacement of 20 mm) and fault cores (displacement of 120 mm). Following direct shear testing, cylindrical plugs with diameter of 38 mm were drilled across the slip surface to be re-activated in a conventional triaxial configuration monitoring the permeability and frictional behaviour of the samples as a function of applied stress. All re-activation experiments on faulted plugs showed consistent frictional response consisting of an initial fast hardening followed by apparent yield up to a friction coefficient of approximately 0.6 attained at around 2 mm of displacement. Permeability in the re-activation experiments shows exponential decay with increasing mean effective stress. The rate of permeability decline with mean effective stress is higher in the fault core plugs than in the simulated damage zone ones. It can be concluded that the presence of gouge in un-cemented carbonate faults results in their sealing character and that leakage cannot be achieved by renewed movement on the fault plane alone, at least not within the range of slip measureable with our apparatus (i.e. approximately 7 mm of cumulative displacement). Additionally, it is shown that under sub seismic slip rates re-activated carbonate faults remain strong and no frictional

Pyrimidine nucleobase radical reactivity in DNA and RNA

Science.gov (United States)

Greenberg, Marc M.

2016-11-01

Nucleobase radicals are major products of the reactions between nucleic acids and hydroxyl radical, which is produced via the indirect effect of ionizing radiation. The nucleobase radicals also result from hydration of cation radicals that are produced via the direct effect of ionizing radiation. The role that nucleobase radicals play in strand scission has been investigated indirectly using ionizing radiation to generate them. More recently, the reactivity of nucleobase radicals resulting from formal hydrogen atom or hydroxyl radical addition to pyrimidines has been studied by independently generating the reactive intermediates via UV-photolysis of synthetic precursors. This approach has provided control over where the reactive intermediates are produced within biopolymers and facilitated studying their reactivity. The contributions to our understanding of pyrimidine nucleobase radical reactivity by this approach are summarized.

Neural correlates of sexual cue reactivity in individuals with and without compulsive sexual behaviours.

Science.gov (United States)

Voon, Valerie; Mole, Thomas B; Banca, Paula; Porter, Laura; Morris, Laurel; Mitchell, Simon; Lapa, Tatyana R; Karr, Judy; Harrison, Neil A; Potenza, Marc N; Irvine, Michael

2014-01-01

Although compulsive sexual behaviour (CSB) has been conceptualized as a "behavioural" addiction and common or overlapping neural circuits may govern the processing of natural and drug rewards, little is known regarding the responses to sexually explicit materials in individuals with and without CSB. Here, the processing of cues of varying sexual content was assessed in individuals with and without CSB, focusing on neural regions identified in prior studies of drug-cue reactivity. 19 CSB subjects and 19 healthy volunteers were assessed using functional MRI comparing sexually explicit videos with non-sexual exciting videos. Ratings of sexual desire and liking were obtained. Relative to healthy volunteers, CSB subjects had greater desire but similar liking scores in response to the sexually explicit videos. Exposure to sexually explicit cues in CSB compared to non-CSB subjects was associated with activation of the dorsal anterior cingulate, ventral striatum and amygdala. Functional connectivity of the dorsal anterior cingulate-ventral striatum-amygdala network was associated with subjective sexual desire (but not liking) to a greater degree in CSB relative to non-CSB subjects. The dissociation between desire or wanting and liking is consistent with theories of incentive motivation underlying CSB as in drug addictions. Neural differences in the processing of sexual-cue reactivity were identified in CSB subjects in regions previously implicated in drug-cue reactivity studies. The greater engagement of corticostriatal limbic circuitry in CSB following exposure to sexual cues suggests neural mechanisms underlying CSB and potential biological targets for interventions.

Latent Virus Reactivation in Space Shuttle Astronauts

Science.gov (United States)

Mehta, S. K.; Crucian, B. E.; Stowe, R. P.; Sams, C.; Castro, V. A.; Pierson, D. L.

2011-01-01

Latent virus reactivation was measured in 17 astronauts (16 male and 1 female) before, during, and after short-duration Space Shuttle missions. Blood, urine, and saliva samples were collected 2-4 months before launch, 10 days before launch (L-10), 2-3 hours after landing (R+0), 3 days after landing (R+14), and 120 days after landing (R+120). Epstein-Barr virus (EBV) DNA was measured in these samples by quantitative polymerase chain reaction. Varicella-zoster virus (VZV) DNA was measured in the 381 saliva samples and cytomegalovirus (CMV) DNA in the 66 urine samples collected from these subjects. Fourteen astronauts shed EBV DNA in 21% of their saliva samples before, during, and after flight, and 7 astronauts shed VZV in 7.4% of their samples during and after flight. It was interesting that shedding of both EBV and VZV increased during the flight phase relative to before or after flight. In the case of CMV, 32% of urine samples from 8 subjects contained DNA of this virus. In normal healthy control subjects, EBV shedding was found in 3% and VZV and CMV were found in less than 1% of the samples. The circadian rhythm of salivary cortisol measured before, during, and after space flight did not show any significant difference between flight phases. These data show that increased reactivation of latent herpes viruses may be associated with decreased immune system function, which has been reported in earlier studies as well as in these same subjects (data not reported here).

The effects of applying silicon carbide coating on core reactivity of pebble-bed HTR in water ingress accident

Energy Technology Data Exchange (ETDEWEB)

Zuhair, S.; Setiadipura, Topan [National Nuclear Energy Agency of Indonesia, Serpong Tagerang Selatan (Indonesia). Center for Nuclear Reactor Technology and Safety; Su' ud, Zaki [Bandung Institute of Technology (Indonesia). Dept. of Physics

2017-03-15

Graphite is used as the moderator, fuel barrier material, and core structure in High Temperature Reactors (HTRs). However, despite its good thermal and mechanical properties below the radiation and high temperatures, it cannot avoid corrosion as a consequence of an accident of water/air ingress. Degradation of graphite as a main HTR material and the formation of dangerous CO gas is a serious problem in HTR safety. One of the several steps that can be adopted to avoid or prevent the corrosion of graphite by the water/air ingress is the application of a thin layer of silicon carbide (SiC) on the surface of the fuel element. This study investigates the effect of applying SiC coating on the fuel surfaces of pebble-bed HTR in water ingress accident from the reactivity points of view. A series of reactivity calculations were done with the Monte Carlo transport code MCNPX and continuous energy nuclear data library ENDF/B-VII at temperature of 1200 K. Three options of UO{sub 2}, PuO{sub 2}, and ThO{sub 2}/UO{sub 2} fuel kernel were considered to obtain the inter comparison of the core reactivity of pebble-bed HTR in conditions of water/air ingress accident. The calculation results indicated that the UO{sub 2}-fueled pebble-bed HTR reactivity was slightly reduced and relatively more decreased when the thickness of the SiC coating increased. The reactivity characteristic of ThO{sub 2}/UO{sub 2}-fueled pebble-bed HTR showed a similar trend to that of UO{sub 2}, but did not show reactivity peak caused by water ingress. In contrast with UO{sub 2}- and ThO{sub 2}-fueled pebble-bed HTR, although the reactivity of PuO{sub 2}-fueled pebble-bed HTR was the lowest, its characteristics showed a very high reactivity peak (0.33 Δk/k) and this introduction of positive reactivity is difficult to control. SiC coating on the surface of the plutonium fuel pebble has no significant impact. From the comparison between reactivity characteristics of uranium, thorium and plutonium cores with 0

Living alongside railway tracks: Long-term effects of nocturnal noise on sleep and cardiovascular reactivity as a function of age.

Science.gov (United States)

Tassi, Patricia; Rohmer, Odile; Schimchowitsch, Sarah; Eschenlauer, Arnaud; Bonnefond, Anne; Margiocchi, Florence; Poisson, Franck; Muzet, Alain

2010-10-01

Very few studies were devoted to permanent effects of nocturnal railway noise on sleep and cardiovascular reactivity. We investigated the effects of nocturnal railway noise on sleep and cardiovascular response in young and middle-aged adults living for many years either near a railway track or in a quiet area. Forty subjects (50% males) divided into two age groups (juniors: 26.2+/-3.6 and seniors: 56.2+/-4.2) participated in this experiment. Half of them lived near a railway track (RW group: 2.6 to 19 years) and the other half in a quiet environment (QE group: 8.1 to 14.2 years). After an adaptation night, all subjects underwent two nights in the laboratory: one control night and one noisy night (30 by-passes of a freight train). Sleep and cardiovascular modifications were assessed in response to noise. Sleep fragmentation indices were lower in RW subjects compared to QE whatever their age. In response to noise, there was a higher cardiovascular response rate to noise in RW juniors and a lower cardiovascular response rate in RW seniors compared to their age-paired QE counterparts. In conclusion, permanent exposure to nocturnal railway noise leads to decreased sleep fragmentation and to cardiovascular habituation. It is suggested that during the initial period experienced by residents living near railway tracks, nocturnal railway noise could induce a sensitization process on the autonomic response to noise reflecting a startle/defense reflex due to its functional significance, which progressively turns to habituation in the long-term if no adverse effect is experienced. Copyright 2010 Elsevier Ltd. All rights reserved.

Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

Science.gov (United States)

Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

2012-08-01

To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

Long term storage effects of irradiated fuel elements on power distribution and reactivity

Energy Technology Data Exchange (ETDEWEB)

Ponzoni Filho, P.; Sato, Sadakatu; Santos, Teresinha Ipojuca Cardoso T.I.C.; Fernandes Vanderlei Borba [FURNAS, Rio de Janeiro, RJ (Brazil); Fetterman, R.J. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

1995-12-31

The ALPHA/PHOENIX-P/ANC (APA) code package was used to calculate the pin by pin power distribution and reactivity for Angra 1 Power Plant, Cycle 5. The Angra 1 Cycle 5 core was loaded with several irradiated fuel elements which were stored in the Spent Fuel Pool (SFP) for more than 8 years. Generally, neutronic codes take into account the buildup and depletion of just a few key fission, products such as Sm-149. In this paper it is shown that the buildup effects of other fission products must be considered for fuel which has been out of the core for significant periods of time. Impacts of these other fission products can change core reactivity and power distribution. (author). 3 refs, 4 figs, 4 tabs.

Long term storage effects of irradiated fuel elements on power distribution and reactivity

International Nuclear Information System (INIS)

Ponzoni Filho, P.; Sato, Sadakatu; Santos, Teresinha Ipojuca Cardoso T.I.C.; Fernandes Vanderlei Borba; Fetterman, R.J.

1995-01-01

The ALPHA/PHOENIX-P/ANC (APA) code package was used to calculate the pin by pin power distribution and reactivity for Angra 1 Power Plant, Cycle 5. The Angra 1 Cycle 5 core was loaded with several irradiated fuel elements which were stored in the Spent Fuel Pool (SFP) for more than 8 years. Generally, neutronic codes take into account the buildup and depletion of just a few key fission, products such as Sm-149. In this paper it is shown that the buildup effects of other fission products must be considered for fuel which has been out of the core for significant periods of time. Impacts of these other fission products can change core reactivity and power distribution. (author). 3 refs, 4 figs, 4 tabs

Reactivity estimation during a reactivity-initiated accident using the extended Kalman filter

International Nuclear Information System (INIS)

Busquim e Silva, R.; Marques, A.L.F.; Cruz, J.J.; Shirvan, K.; Kazimi, M.S.

2015-01-01

Highlights: • The EKF is modeled using sophisticate strategies to make the algorithm robust and accurate. • For a supercritical reactor under RIA, the EKF presents better results compared to IPK method independent of magnitude of the noise loads. • A sensitivity for five distinct carry-over effects indicates that the EKF is less sensitive to the different set of noise. • Although the P3D/R5 simulates the reactivity using a spatial kinetics method, the use of PKRE to model the EKF provides accurate results. • The reactivity’s standard deviation is higher for the IKF method. • Under HZP (slow power response) the IPK reactivity varies widely from positive to negative values (add extra difficulty to controlling the supercritical reactor): the EKF method does not have similar behavior under the same conditions (better controlling the operation). - Abstract: This study implements the extended Kalman filter (EKF) to estimate the nuclear reactor reactivity behavior under a reactivity-initiated accident (RIA). A coupled neutronics/thermal hydraulics code PARCS/RELAP5 (P3D/R5) simulates a control rod assembly ejection (CRE) on a traditional 2272 MWt PWR to generate the reactor power profile. A MATLAB script adds random noise to the simulated reactor power. For comparison, the inverse point kinetics (IPK) deterministic method is also implemented. Three different cases of CRE are simulated and the EKF, IPK and the P3D/R5 reactivity are compared. It was found that the EKF method presents better results compared to the IPK method. Furthermore, under a RIA due to small reactivity insertion and slow power response, the IPK reactivity varies widely from positive to negative, which may add extra difficulty to the task of controlling a supercritical reactor. This feature is also confirmed by a sensitivity analysis for five different noise loads and three distinct noise measurements standard deviations (SD)

Effects of a prevention program for divorced families on youth cortisol reactivity 15 years later.

Science.gov (United States)

Luecken, Linda J; Hagan, Melissa J; Mahrer, Nicole E; Wolchik, Sharlene A; Sandler, Irwin N; Tein, Jenn-Yun

2015-01-01

We examined whether an empirically based, randomised controlled trial of a preventive intervention for divorced mothers and children had a long-term impact on offspring cortisol regulation. Divorced mothers and children (age 9-12) were randomly assigned to a literature control condition or the 11-week New Beginnings Program, a family-focused group preventive intervention for mothers and children in newly divorced families. Fifteen years after the trial, offspring salivary cortisol (n = 161) was measured before and after a social stress task. Multilevel mixed models were used to predict cortisol from internalizing symptoms, externalizing symptoms, group assignment and potential moderators of intervention effects. Across the sample, higher externalizing symptoms were associated with lower cortisol reactivity. There was a significant group-by-age interaction such that older offspring in the control group had higher reactivity relative to the intervention group, and younger offspring in the control group exhibited a decline across the task relative to younger offspring in the intervention group. Preventive interventions for youth from divorced families may have a long-term impact on cortisol reactivity to stress. Results highlight the importance of examining moderators of program effects.

MTR fuel element burn-up measurements by the reactivity method

International Nuclear Information System (INIS)

Zuniga, A.; Cuya, T.R.; Ravnik, M.

2003-01-01

Fuel element burn-up was measured by the reactivity method in the 10 MW Peruvian MTR reactor RP-10. The main purpose of the experiment was testing the reactivity method for an MTR reactor as the reactivity method was originally developed for TRIGA reactors. The reactivity worth of each measured fuel element was measured in its original core position in order to measure the burn-up of the fuel elements that were part of the experimental core. The burn-up of each measured fuel element was derived by interpolating its reactivity worth from the reactivity worth of two reference fuel elements of known burn-up, whose reactivity worth was measured in the position of the measured fuel element. The accuracy of the method was improved by separating the reactivity effect of burn-up from the effect of the position in the core. The results of the experiment showed that the modified reactivity method for fuel element burn-up determination could be applied also to MTR reactors. (orig.)

Mediating role of stress reactivity in the effects of prenatal tobacco exposure on childhood mental health outcomes.

Science.gov (United States)

Park, Aesoon; O'Malley, Stephanie S; King, Sarah L; Picciotto, Marina R

2014-02-01

Prenatal tobacco exposure, through maternal smoking during pregnancy, has been associated with adverse mental health outcomes in childhood. However, the mechanisms by which prenatal tobacco exposure compromises mental health later in life are unclear. We hypothesized that sensitized reactivity to stressful life events in early childhood mediates the effect of prenatal tobacco exposure on mental health outcomes in middle childhood, after accounting for earlier mental health outcomes. Data were from 12,308 mothers and their children drawn from the Avon Longitudinal Study of Parents and Children, a large prospective population-based study. Mothers' self-reports of smoking during pregnancy, mothers' ratings of their child's reactivity to stressful life events, and teachers' and mothers' ratings of the Strengths and Difficulties Questionnaire assessing 5 domains of mental health outcomes were measured. A positive association was found between prenatal tobacco exposure and stress reactivity between the ages of 2 and 6. In turn, stress reactivity was positively associated with peer (isolation), hyperactivity, conduct, and emotional problems (but not prosocial behaviors) between the ages of 7 and 11, after accounting for the mental health outcome at age 4 and other confounders. Heightened stress reactivity in preschool ages mediated the effect of prenatal tobacco exposure on adverse mental health outcomes between the ages of 7 and 11. Interventions to assist children exposed to tobacco smoke during gestation in coping with stressful life events may help mitigate psychiatric symptoms in this population.

Lysosome-Targeting Amplifiers of Reactive Oxygen Species as Anticancer Prodrugs

Czech Academy of Sciences Publication Activity Database

Daum, S.; Reshetnikov, M.S.V.; Šíša, Miroslav; Dumych, T.; Lootsik, M. D.; Bilyy, R.; Bila, E.; Janko, C.; Alexiou, C.; Herrmann, M.; Sellner, L.; Mokhir, A.

2017-01-01

Roč. 56, č. 49 (2017), s. 15545-15549 ISSN 1433-7851 Institutional support: RVO:61389030 Keywords : aminoferrocene * cancer * lysosomes * prodrugs * reactive oxygen species Subject RIV: ED - Physiology OBOR OECD: Organic chemistry Impact factor: 11.994, year: 2016

Sleep deprived and sweating it out: the effects of total sleep deprivation on skin conductance reactivity to psychosocial stress.

Science.gov (United States)

Liu, Jean C J; Verhulst, Silvan; Massar, Stijn A A; Chee, Michael W L

2015-01-01

We examined how sleep deprivation alters physiological responses to psychosocial stress by evaluating changes in skin conductance. Between-subjects design with one group allocated to 24 h of total sleep deprivation and the other to rested wakefulness. The study took place in a research laboratory. Participants were 40 healthy young adults recruited from a university. Sleep deprivation and feedback. Electrodermal activity was monitored while participants completed a difficult perceptual task with false feedback. All participants showed increased skin conductance levels following stress. However, compared to well-rested participants, sleep deprived participants showed higher skin conductance reactivity with increasing stress levels. Our results suggest that sleep deprivation augments allostatic responses to increasing psychosocial stress. Consequentially, we propose sleep loss as a risk factor that can influence the pathogenic effects of stress. © 2014 Associated Professional Sleep Societies, LLC.

Design and Development of Virtual Reactivity System for PWR

International Nuclear Information System (INIS)

Anwar, M. I.

2012-01-01

The reactivity monitoring and investigation is an important mean to ensure the safety operation of a nuclear power plant. But the reactivity of the nuclear reactor usually cannot be directly measured. It should be computed with certain estimation method. In this thesis, an effort has been made using an artificial neural network and highly fluctuating experimental data for predicting the total reactivity of the nuclear reactor based on all components of net reactivity. This virtual reactivity system is designed by taking advantage of neural network's nonlinear mapping capability. Based on analysis of the reactivity contributing factors, several neural network models are built separately for control rod, boron, poisons, fuel Doppler Effect and moderator effect. Extensive simulation and validation tests for PWR show that satisfied results have been obtained with the proposed approach. It presents a new idea to estimate the PWR's reactivity using artificial intelligence. All the design and simulation work is carried out in MATLAB and a real time programming environment is chosen for the computation and prediction of reactivity. (author)

Effect of exhaust gas recirculation (EGR) and multiple injections on diesel soot nano-structure and reactivity

International Nuclear Information System (INIS)

Rohani, Behzad; Bae, Choongsik

2017-01-01

-cylinder soot oxidation, and the consequent effect on the soot surface roughness. Results also show that the influence of injection strategy on the soot reactivity and VOF content tends to vanish as EGR is added.

Gender differences in cue exposure reactivity and 9-month outcome.

Science.gov (United States)

Sterling, Robert C; Dean, Jessica; Weinstein, Stephen P; Murphy, Jennifer; Gottheil, Edward

2004-07-01

Gender differences have been shown to be related to the course of cocaine dependence and treatment. While previous research has shown cue exposure procedures to be somewhat effective at reducing reactivity of substance dependent individuals to drug related stimuli, the few studies that have examined gender differences in craving and cue-reactivity have yielded equivocal results. We have recently demonstrated that an active cue-exposure procedure that featured cocaine-dependent individuals receiving immediate feedback about their level of physiological arousal following videotaped exposure to cocaine-related stimuli was capable of positively influencing in-treatment (helplessness, abstinence efficacy) as well as 9-month followup outcome (i.e., urinalysis) indices (Sterling, R., Gottheil, E., Murphy, J., & Weinstein, S. (2001). Cue exposure and abstinence efficacy. College on Problems of Drug Dependence, Phoenix, AZ, June 17, 2001). The purpose of the present study was to determine whether differential in-treatment or 9-month followup outcomes were obtained for male and female study participants. Subjects in this study were 81 individuals (47 male/34 female) who met DSM-IV criteria for cocaine dependence and who had consented to be randomly assigned to either the active cue-exposure or control conditions. Participants were compared along a myriad of pre-treatment, in-treatment, and 9-month followup measures. Other than males reporting more recent employment, there was no obvious systematic pattern of differences on pre-treatment indices. No gender differences in treatment retention were observed. With respect to 9-month followup, no gender differences on measures of addiction severity, psychological functioning, or urinalyses were noted. However males were more "cue-reactive" and more successful at establishing control over their reactivity to the cocaine stimuli. Additional research is needed to determine whether these differences in reactivity can be more clearly

Secure provision of reactive power ancillary services in competitive electricity markets

Science.gov (United States)

El-Samahy, Ismael

The research work presented in this thesis discusses various complex issues associated with reactive power management and pricing in the context of new operating paradigms in deregulated power systems, proposing appropriate policy solutions. An integrated two-level framework for reactive power management is set forth, which is both suitable for a competitive market and ensures a secure and reliable operation of the associated power system. The framework is generic in nature and can be adopted for any electricity market structure. The proposed hierarchical reactive power market structure comprises two stages: procurement of reactive power resources on a seasonal basis, and real-time reactive power dispatch. The main objective of the proposed framework is to provide appropriate reactive power support from service providers at least cost, while ensuring a secure operation of the power system. The proposed procurement procedure is based on a two-step optimization model. First, the marginal benefits of reactive power supply from each provider, with respect to system security, are obtained by solving a loadability-maximization problem subject to transmission security constraints imposed by voltage and thermal limits. Second, the selected set of generators is determined by solving an optimal power flow (OPF)-based auction. This auction maximizes a societal advantage function comprising generators' offers and their corresponding marginal benefits with respect to system security, and considering all transmission system constraints. The proposed procedure yields the selected set of generators and zonal price components, which would form the basis for seasonal contracts between the system operator and the selected reactive power service providers. The main objective of the proposed reactive power dispatch model is to minimize the total payment burden on the Independent System Operator (ISO), which is associated with reactive power dispatch. The real power generation is

Cue reactivity in non-daily smokers: effects on craving and on smoking behavior.

Science.gov (United States)

Shiffman, Saul; Dunbar, Michael S; Kirchner, Thomas R; Li, Xiaoxue; Tindle, Hilary A; Anderson, Stewart J; Scholl, Sarah M; Ferguson, Stuart G

2013-03-01

Non-daily, or intermittent smokers (ITS), are increasingly prevalent. Their smoking may be more situational than that of daily smokers (DS), and thus is hypothesized to be more influenced by cues. To assess ITS' response to cues, and compare it to that of DS. Samples of 239 ITS and 207 DS (previously reported in Shiffman et al. 2012a) were studied in 2,586 laboratory cue-reactivity sessions. Craving (Questionnaire of Smoking Urges) and smoking (probability, latency, puff parameters, and carbon monoxide increases) in response to cues was assessed following exposure to neutral cues and cues related to smoking, alcohol, negative affect, positive affect, and smoking prohibitions. Mixed effects models, generalized estimating equations and random-effects survival analyses were used to assess response to cues and differences between DS and ITS. ITS' craving increased following exposure to smoking and alcohol cues and decreased following positive affect cues, but cues had little effect on smoking behaviors. Cue reactivity was similar in ITS and DS. Among ITS, craving intensity predicted smoking probability, latency, and intensity, and the effects on latency were stronger among ITS than DS. Contrary to hypotheses, ITS were not more responsive to laboratory cues than DS. Results show that ITS do experience craving and craving increases that are then associated with smoking.

pH effect on decolorization of raw textile wastewater polluted with reactive dyes by advanced oxidation with uv/h2o2

NARCIS (Netherlands)

Racyte, J.; Rimeika, M.; Bruning, H.

2009-01-01

The effectiveness of the advanced oxidation process (UV/H2O2) in decolorizing real textile wastewater polluted with commercial reactive dyes - Reactive Yellow 84 and Reactive Red 141 was investigated. All the experiments were performed in a lab-scale reactor with the original high pH of the

Social support and loneliness in college students: effects on pulse pressure reactivity to acute stress.

Science.gov (United States)

O'Donovan, Aoife; Hughes, Brian

2007-01-01

Socially supportive relationships at university may buffer against psychological stress in students, particularly in those experiencing loneliness. To examine the relation of social support at university and loneliness with pulse pressure (PP) reactivity to acute psychological stress in a sample of first-year undergraduate students. Sixty-five female, adolescent, first-year university students. Pulse pressure (PP) was calculated as the arithmetic difference between systolic blood pressure and diastolic blood pressure, which were measured during a resting baseline and during a stressful reading task. The difference between baseline and reading task PP represents PP reactivity. The Social Support at University Scale (SSUS) was used to assess social support availability in university, and the Revised UCLA Loneliness Scale was used to assess loneliness. Hierarchical linear regression was used to examine main and interactive effects of SSUS and loneliness on PP change scores, and simple slopes were computed to assist in the interpretation of interaction effects. Social support at university was associated with lower PP reactivity in students reporting medium (t = -2.03, p = .04) or high levels of loneliness (t = -2.93, p = .004), but not in those reporting low levels of loneliness (t = -0.20, p = .83). Psychosocial interventions designed to increase social support available at university, and targeted at students experiencing loneliness may buffer against the harmful effects of acute stressors in lonely first-year students.

Biological Sensitivity to Context: The Interactive Effects of Stress Reactivity and Family Adversity on Socioemotional Behavior and School Readiness

Science.gov (United States)

Obradovic, Jelena; Bush, Nicole R.; Stamperdahl, Juliet; Adler, Nancy E.; Boyce, W. Thomas

2010-01-01

This study examined the direct and interactive effects of stress reactivity and family adversity on socioemotional and cognitive development in three hundred and thirty-eight 5- to 6-year-old children. Neurobiological stress reactivity was measured as respiratory sinus arrhythmia and salivary cortisol responses to social, cognitive, sensory, and…

Effect of Relative Humidity and CO2 Concentration on the Properties of Carbonated Reactive MgO Cement Based Materials

Science.gov (United States)

Bilan, Yaroslav

Sustainability of modern concrete industry recently has become an important topic of scientific discussion, and consequently there is an effort to study the potential of the emerging new supplementary cementitious materials. This study has a purpose to investigate the effect of reactive magnesia (reactive MgO) as a replacement for general use (GU) Portland Cements and the effect of environmental factors (CO2 concentrations and relative humidity) on accelerated carbonation curing results. The findings of this study revealed that improvement of physical properties is related directly to the increase in CO2 concentrations and inversely to the increase in relative humidity and also depends much on %MgO in the mixture. The conclusions of this study helped to clarify the effect of variable environmental factors and the material replacement range on carbonation of reactive magnesia concrete materials, as well as providing an assessment of the optimal conditions for the effective usage of the material.

Neural mechanisms of reactivation-induced updating that enhance and distort memory.

Science.gov (United States)

St Jacques, Peggy L; Olm, Christopher; Schacter, Daniel L

2013-12-03

We remember a considerable number of personal experiences because we are frequently reminded of them, a process known as memory reactivation. Although memory reactivation helps to stabilize and update memories, reactivation may also introduce distortions if novel information becomes incorporated with memory. Here we used functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms mediating reactivation-induced updating in memory for events experienced during a museum tour. During scanning, participants were shown target photographs to reactivate memories from the museum tour followed by a novel lure photograph from an alternate tour. Later, participants were presented with target and lure photographs and asked to determine whether the photographs showed a stop they visited during the tour. We used a subsequent memory analysis to examine neural recruitment during reactivation that was associated with later true and false memories. We predicted that the quality of reactivation, as determined by online ratings of subjective recollection, would increase subsequent true memories but also facilitate incorporation of the lure photograph, thereby increasing subsequent false memories. The fMRI results revealed that the quality of reactivation modulated subsequent true and false memories via recruitment of left posterior parahippocampal, bilateral retrosplenial, and bilateral posterior inferior parietal cortices. However, the timing of neural recruitment and the way in which memories were reactivated contributed to differences in whether memory reactivation led to distortions or not. These data reveal the neural mechanisms recruited during memory reactivation that modify how memories will be subsequently retrieved, supporting the flexible and dynamic aspects of memory.

Effect of oral contraceptives and/or metformin on GLP-1 secretion and reactive hypoglycemia in PCOS

DEFF Research Database (Denmark)

Glintborg, Dorte; Mumm, Hanne; Holst, Jens Juul

2017-01-01

CONTEXT: Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS ...... significantly lower in obese vs. lean patients and were inversely associated with BMI. CONCLUSIONS: AUC GLP-1 levels were unchanged during treatment. Increased risk of hypoglycemia during metformin +OCP could be associated with increased insulin secretion.......CONTEXT: Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS......, glucose, insulin, and C-peptide during 5 h OGTT. RESULTS: Fasting GLP-1 levels increased during metformin+OCP vs. OCP treatment, whereas AUC GLP-1 levels were unchanged during medical treatment. The prevalence of reactive hypoglycemia increased from 9/65 to 14/65 after intervention (P

Investigation of Reactivity Feedback Mechanism of Axial and Radial Expansion Effect of Metal-Fueled Sodium-Cooled Fast Reactor

International Nuclear Information System (INIS)

Seong, Seung-Hwan; Choi, Chi-Woong; Jeong, Tae-Kyung; Ha, Gi-Seok

2015-01-01

The major inherent reactivity feedback models for a ceramic fuel used in a conventional light water reactor are Doppler feedback and moderator feedback. The metal fuel has these two reactivity feedback mechanisms previously mentioned. In addition, the metal fuel has two more reactivity feedback models related to the thermal expansion phenomena of the metal fuel. Since the metal fuel has a good capability to expand according to the temperature changes of the core, two more feedback mechanisms exist. These additional two feedback mechanism are important to the inherent safety of metal fuel and can make metal-fueled SFR safer than oxide-fueled SFR. These phenomena have already been applied to safety analysis on design extended condition. In this study, the effect of these characteristics on power control capability was examined through a simple load change operation. The axial expansion mechanism is induced from the change of the fuel temperature according to the change of the power level of PGSFR. When the power increases, the fuel temperatures in the metal fuel will increase and then the reactivity will decrease due to the axial elongation of the metal fuel. To evaluate the expansion effect, 2 cases were simulated with the same scenario by using MMS-LMR code developed at KAERI. The first simulation was to analyze the change of the reactor power according to the change of BOP power without the reactivity feedback model of the axial and radial expansion of the core during the power transient event. That is to say, the core had only two reactivity feedback mechanism of Doppler and coolant temperature

Effect of nonlinear void reactivity on bifurcation characteristics of a lumped-parameter model of a BWR: A study relevant to RBMK

Energy Technology Data Exchange (ETDEWEB)

Verma, Dinkar, E-mail: dinkar@iitk.ac.in [Nuclear Engineering and Technology Program, Indian Institute of Technology Kanpur, Kanpur 208 016 (India); Kalra, Manjeet Singh, E-mail: drmanjeet.singh@dituniversity.edu.in [DIT University, Dehradun 248 009 (India); Wahi, Pankaj, E-mail: wahi@iitk.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

2017-04-15

Highlights: • A simplified model with nonlinear void reactivity feedback is studied. • Method of multiple scales for nonlinear analysis and oscillation characteristics. • Second order void reactivity dominates in determining system dynamics. • Opposing signs of linear and quadratic void reactivity enhances global safety. - Abstract: In the present work, the effect of nonlinear void reactivity on the dynamics of a simplified lumped-parameter model for a boiling water reactor (BWR) is investigated. A mathematical model of five differential equations comprising of neutronics and thermal-hydraulics encompassing the nonlinearities associated with both the reactivity feedbacks and the heat transfer process has been used. To this end, we have considered parameters relevant to RBMK for which the void reactivity is known to be nonlinear. A nonlinear analysis of the model exploiting the method of multiple time scales (MMTS) predicts the occurrence of the two types of Hopf bifurcation, namely subcritical and supercritical, leading to the evolution of limit cycles for a range of parameters. Numerical simulations have been performed to verify the analytical results obtained by MMTS. The study shows that the nonlinear reactivity has a significant influence on the system dynamics. A parametric study with varying nominal reactor power and operating conditions in coolant channel has also been performed which shows the effect of change in concerned parameter on the boundary between regions of sub- and super-critical Hopf bifurcations in the space constituted by the two coefficients of reactivities viz. the void and the Doppler coefficient of reactivities. In particular, we find that introduction of a negative quadratic term in the void reactivity feedback significantly increases the supercritical region and dominates in determining the system dynamics.

The effect of Helicobacter pylori eradication on macrophage migration inhibitory factor, C-reactive protein and fetuin-a levels

Directory of Open Access Journals (Sweden)

Levent Kebapcilar

2010-06-01

Full Text Available OBJECTIVES: To determine the effect of Helicobacter pylori (H. pylori eradication on blood levels of high-sensitivity C-reactive protein (hs-CRP, macrophage migration inhibitory factor and fetuin-A in patients with dyspepsia who are concurrently infected with H. pylori. METHODS: H.pylori infection was diagnosed based on the 14C urea breath test (UBT and histology. Lansoprazole 30 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily were given to all infected patients for 14 days; 14C UBT was then re-measured. In 30 subjects, migration inhibitory factor, fetuin-A and hs-CRP levels were examined before and after the eradication of H. pylori infection and compared to levels in 30 healthy subjects who tested negative for H. pylori infection. RESULTS: Age and sex distribution were comparable between patients and controls. Migration inhibitory factor and hs-CRP levels were higher, and fetuin-A levels were lower, in H. pylori-infected patients (p0.05. CONCLUSION: These findings suggest that H. pylori eradication reduces the levels of pro-inflammatory cytokines such as migration inhibitory factor and hs-CRP and also results in a significant increase in anti-inflammatory markers such as fetuin-A.

Pay-as-bid based reactive power market

International Nuclear Information System (INIS)

Amjady, N.; Rabiee, A.; Shayanfar, H.A.

2010-01-01

In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

Pay-as-bid based reactive power market

Energy Technology Data Exchange (ETDEWEB)

Amjady, N. [Department of Electrical Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Rabiee, A., E-mail: Rabiee@iust.ac.i [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

2010-02-15

In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

Effects on nano zero-valent iron reactivity of interactions between hardness, alkalinity, and natural organic matter in reverse osmosis concentrate

DEFF Research Database (Denmark)

Hwang, Yuhoon; Shin, Hang-Sik

2013-01-01

, the influence of hardness, alkalinity, and organic matter on NZVI reactivity was evaluated by the response surface method (RSM). Hardness (Ca2 ) had a positive effect on NZVI reactivity by accelerating iron corrosion. In contrast, alkalinity (bicarbonate; HCO3-) and organic matter (humic acid; HA) had negative...... effects on NZVI reactivity due to morphological change to carbonate green rust, and to competitive adsorption of HA, respectively. The validity of the statistical prediction model derived from RSM was confirmed by an additional confirmation experiment, and the experimental result was within the 95......% confidential interval. Therefore, it can be said that the RSM model produced results that were statistically significant....

Chemical reactivity of cation-exchanged zeolites

OpenAIRE

Pidko, E.A.

2008-01-01

Zeolites modified with metal cations have been extensively studied during the last two decades because of their wide application in different technologically important fields such as catalysis, adsorption and gas separation. Contrary to the well-understood mechanisms of chemical reactions catalyzed by Brønsted acid sites in the hydrogen forms of zeolites, the nature of chemical reactivity, and related, the structure of the metal-containing ions in cation-exchanged zeolites remains the subject...

The Effect of Aging on the Dynamics of Reactive and Proactive Cognitive Control of Response Interference.

Science.gov (United States)

Xiang, Ling; Zhang, Baoqiang; Wang, Baoxi; Jiang, Jun; Zhang, Fenghua; Hu, Zhujing

2016-01-01

A prime-target interference task was used to investigate the effects of cognitive aging on reactive and proactive control after eliminating frequency confounds and feature repetitions from the cognitive control measures. We used distributional analyses to explore the dynamics of the two control functions by distinguishing the strength of incorrect response capture and the efficiency of suppression control. For reactive control, within-trial conflict control and between-trial conflict adaption were analyzed. The statistical analysis showed that there were no reliable between-trial conflict adaption effects for either young or older adults. For within-trial conflict control, the results revealed that older adults showed larger interference effects on mean RT and mean accuracy. Distributional analyses showed that the decline mainly stemmed from inefficient suppression rather than from stronger incorrect responses. For proactive control, older adults showed comparable proactive conflict resolution to young adults on mean RT and mean accuracy. Distributional analyses showed that older adults were as effective as younger adults in adjusting their responses based on congruency proportion information to minimize automatic response capture and actively suppress the direct response activation. The results suggest that older adults were less proficient at suppressing interference after conflict was detected but can anticipate and prevent inference in response to congruency proportion manipulation. These results challenge earlier views that older adults have selective deficits in proactive control but intact reactive control.

Effect of alpha irradiation on UO2 surface reactivity in aqueous media

International Nuclear Information System (INIS)

Jegou, C.; Muzeau, B.; Broudic, V.; Poulesquen, A.; Roudil, D.; Jorion, F.; Corbel, C.

2005-01-01

The option of direct disposal of spent nuclear fuel in a deep geological formation raises the need to investigate the long-term behavior of the UO 2 matrix in aqueous media subjected to α-β-γ radiation. The β-γ emitters account for most of the activity of spent fuel at the moment it is removed from the reactor, but diminish within a millennial time frame by over three orders of magnitude to less than the long-term activity. The latter persists over much longer time periods and must therefore be taken into account over a geological disposal time scale. Leaching experiments with solution renewal were carried out on UO 2 pellets doped with alpha emitters ( 238 Pu and 239 Pu) to quantify the impact of alpha irradiation on UO 2 matrix alteration. Three batches of doped UO 2 pellets with different alpha flux levels (3.30 x 10 4 , 3.30 x 10 5 , and 3.2 x 10 6 α cm -2 s -1 ) were studied. The results obtained in aerated and deaerated media immediately after sample annealing or interim storage in air provide a better understanding of the UO 2 matrix alteration mechanisms under alpha irradiation. Interim storage in air of UO 2 pellets doped with alpha emitters results in variations of the UO 2 surface reactivity, which depends on the alpha particle flux at the interface and on the interim storage duration. The variation in the surface reactivity and the greater uranium release following interim storage cannot be attributed to the effect of alpha radiolysis in aerated media since the uranium release tends toward the same value after several leaching cycles for the doped UO 2 pellet batches and spent fuel. Oxygen diffusion enhanced by alpha irradiation of the extreme surface layer and/or radiolysis of the air could account for the oxidation of the surface UO 2 to UO 2+x . However, leaching experiments performed in deaerated media after annealing the samples and preleaching the surface suggest that alpha radiolysis does indeed affect the dissolution, which varies with the

Reactivity of main components and substituent distribution in esterified sugarcane bagasse prepared by effective solid phase reaction.

Science.gov (United States)

Gan, Tao; Zhang, Yanjuan; Chen, Yane; Hu, Huayu; Yang, Mei; Huang, Zuqiang; Chen, Dong; Huang, Aimin

2018-02-01

Three main components of lignocellulose (cellulose, hemicellulose, and lignin isolated from sugarcane bagasse (SCB)) as well as holocellulose and SCB were modified with maleic acid by mechanical activation (MA)-assisted solid phase reaction (MASPR) technology. The order of reactivity was found to be lignin>hemicellulose>cellulose. The amorphous structure of lignin and hemicellulose mainly attributed to their better reactivity, and the modified lignin could reach a maximum degree of esterification (DE) of 93.45%. MA improved the accessibility and reactivity of cellulose, as the DE of modified cellulose gradually increased with milling time and reached the maximum value of 57.30% at 120min, which had significant effect on structure changes and DE of modified holocellulose and SCB. MA enhanced the esterification of all three components in lignocellulose with relatively high substituent distribution in them, and maleated SCB with a maximum DE of 64.17% was successfully prepared by this simple, green, and effective MASPR technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

EFFECT OF UV IRRADIATION ON THE DYEING OF COTTON FABRIC WITH REACTIVE BLUE 204

Directory of Open Access Journals (Sweden)

ROŞU Liliana

2017-05-01

Full Text Available Reactive dyes are synthetic organic compounds used on a wide scale in textile industry, for painting materials of different types and compositions (e.g. 100% cotton, wool, natural satin, viscose, synthetic fibres. Reactive dyes are solid compounds (powders completely water soluble at normal temperature and pressure conditions. Their structures contain chromophore groups, which generate colour, and auxochrome groups, which determine the compounds water solubility and the capacity to fix to the textile fiber. Such organic compounds absorb UV-Vis radiations at specific wavelengths, corresponding to maximum absorbtion peaks, in both solution and dyed fiber. The human organism, through the dyed clothing, comes in direct contact with those dyes which can undergo modifications once exposed to UV radiations, having the posibility to reach the organism via cutanated transport. As it is known, the provoked negative effects are stronger during summer when UV radiations are more intense and in order to reduce their intensity dark coloured clothing is avoided. Dyes can be transformed in compounds which are easily absorbed into the skin. Some of these metabolites can be less toxic than the original corresponding dye, whilst others, such as free radicals, are potentially cancerous. Knowledge of the biological effects of the organic dyes, reactive dyes in particular, correlated with their structural and physical characteristics, permanently consists an issue of high scientific and practical interest and its solution may contribute in the diminishing of risk factors and improving of population health. UV radiation influence on the structural and colour modifications of textile materials were studied. Colour modifications are due to structural changes in aromatic and carbonil groups. In most cases photo-oxidative processes were identified in the dye structure. Dyeing was performed using non-irradiated and irradiated cotton painted with reactive blue dye 204.

Effective biotransformation and detoxification of anthraquinone dye reactive blue 4 by using aerobic bacterial granules.

Science.gov (United States)

Chaudhari, Ashvini U; Paul, Dhiraj; Dhotre, Dhiraj; Kodam, Kisan M

2017-10-01

Treatment of textile wastewater containing anthraquinone dye is quite a huge challenge due to its complex aromatic structure and toxicity. Present study deals with the degradation and detoxification of anthraquinone dye reactive blue 4 using aerobic bacterial granules. Bacterial granules effectively decolorized reactive blue 4 at wide range of pH (4.0-11.0) and temperature (20-55 °C) as well as decolorized and tolerated high concentration of reactive blue 4 dye upto 1000 mg l -1 with V max 6.16 ± 0.82 mg l -1 h -1 and K m 227 ± 41 mg l -1 . Metagenomics study evaluates important role of Clostridia, Actinobacteria, and Proteobacterial members in biotransformation and tolerance of high concentrations of reactive blue 4 dye. Up-regulation of xenobiotic degradation and environmental information processing pathways during dye exposure signifies their noteworthy role in dye degradation. Biotransformation of dye was confirmed by significant decrease in the values of total suspended solids, biological and chemical oxygen demand. The metabolites formed after biotransformation was characterized by FT-IR and GC-MS analysis. The reactive blue 4 dye was found to be phytotoxic, cytotoxic and genotoxic whereas its biotransformed product were non-toxic. This study comprehensively illustrates that, bacterial aerobic granules can be used for eco-friendly remediation and detoxification of wastewater containing high organic load of anthraquinone dye. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proactive and reactive effects of vigorous exercise on learning and vocabulary comprehension.

Science.gov (United States)

Salis, Andrea S

2013-06-01

College students (N = 90) were randomly assigned to participate in vigorous, moderate or no physical exercise and vocabulary recall and comprehension learning activities under varying conditions to assess whether or not increased intensities of exercise, performed either before a vocabulary recall and comprehension learning activity (i.e., proactive effect) or after a vocabulary recall and comprehension learning activity (i.e., reactive effect), would improve vocabulary recall and comprehension. The results demonstrated that performing exercise at a vigorous intensity before or after rehearsing for a vocabulary comprehension test improved test results.

[Effects of allelochemical dibutyl phthalate on Gymnodinium breve reactive oxygen species].

Science.gov (United States)

Bie, Cong-Cong; Li, Feng-Min; Li, Yuan-Yuan; Wang, Zhen-Yu

2012-02-01

The purpose of this study was to investigate the mechanism of inhibitory action of dibutyl phthalate (DBP) on red tide algae Gymnodinium breve. Reactive oxygen species (ROS) level, contents of *OH and H2O2, and O2*(-) production rate were investigated, and also for the effects of electron transfer inhibitors on the ROS induction of DBP. The results showed that DBP triggered the synthesis of reactive oxygen species ROS, and with the increase of concentration of DBP, *OH and H2O2 contents in cells accumulated, as for the 3 mg x L(-1) DBP treated algae cultures, OH showed a peak of 33 U x mL(-1) at 48 h, which was about 2. 4 times higher than that in the controlled, and H2O2 contents was about 250 nmol x (10(7) cells)(-1) at 72 h, which was about 5 times higher and also was the highest during the whole culture. Rotenone (an inhibitor of complex I in the mitochondria electron transport chain) decreased the DBP induced ROS production, and dicumarol (an inhibitor of the redox enzyme system in the plasma membrane) stimulated the DBP induced ROS production. Taken all together, the results demonstrated DBP induced over production of reactive oxygen species in G. breve, which is the main inhibitory mechanism, and mitochondria and plasma membrane seem to be the main target site of DBP. These conclusions were of scientific meaning on uncovering the inhibitory mechanism of allelochemical on algae.

Neural correlates of sexual cue reactivity in individuals with and without compulsive sexual behaviours.

Directory of Open Access Journals (Sweden)

Valerie Voon

Full Text Available Although compulsive sexual behaviour (CSB has been conceptualized as a "behavioural" addiction and common or overlapping neural circuits may govern the processing of natural and drug rewards, little is known regarding the responses to sexually explicit materials in individuals with and without CSB. Here, the processing of cues of varying sexual content was assessed in individuals with and without CSB, focusing on neural regions identified in prior studies of drug-cue reactivity. 19 CSB subjects and 19 healthy volunteers were assessed using functional MRI comparing sexually explicit videos with non-sexual exciting videos. Ratings of sexual desire and liking were obtained. Relative to healthy volunteers, CSB subjects had greater desire but similar liking scores in response to the sexually explicit videos. Exposure to sexually explicit cues in CSB compared to non-CSB subjects was associated with activation of the dorsal anterior cingulate, ventral striatum and amygdala. Functional connectivity of the dorsal anterior cingulate-ventral striatum-amygdala network was associated with subjective sexual desire (but not liking to a greater degree in CSB relative to non-CSB subjects. The dissociation between desire or wanting and liking is consistent with theories of incentive motivation underlying CSB as in drug addictions. Neural differences in the processing of sexual-cue reactivity were identified in CSB subjects in regions previously implicated in drug-cue reactivity studies. The greater engagement of corticostriatal limbic circuitry in CSB following exposure to sexual cues suggests neural mechanisms underlying CSB and potential biological targets for interventions.

Two-dimensional simulation of reactive diffusion in binary systems

Czech Academy of Sciences Publication Activity Database

Svoboda, Jiří; Stopka, J.; Fischer, F. D.

2014-01-01

Roč. 95, DEC (2014), s. 309-315 ISSN 0927-0256 R&D Projects: GA ČR(CZ) GA14-24252S Institutional support: RVO:68081723 Keywords : Phase transformation * Diffusion-controlled interface migration * Reactive diffusion * Multiphase system * Intermetallic compounds Subject RIV: BJ - Thermodynamics Impact factor: 2.131, year: 2014

Embedded Cluster Models for Reactivity of the Hydrated Electron

Czech Academy of Sciences Publication Activity Database

Uhlig, Frank; Jungwirth, Pavel

2013-01-01

Roč. 227, č. 11 (2013), s. 1583-1593 ISSN 0942-9352 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : hydrated electron * clusters * reactivity * ab initio molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.178, year: 2013

The action of red wine and purple grape juice on vascular reactivity is independent of plasma lipids in hypercholesterolemic patients.

Science.gov (United States)

Coimbra, S R; Lage, S H; Brandizzi, L; Yoshida, V; da Luz, P L

2005-09-01

Although red wine (RW) reduces cardiovascular risk, the mechanisms underlying the effect have not been identified. Correction of endothelial dysfunction by RW flavonoids could be one mechanism. We measured brachial artery reactivity by high-resolution ultrasonography, plasma lipids, glucose, adhesion molecules (ICAM-1 and VCAM), and platelet function in 16 hypercholesterolemic individuals (8 men and 8 women; mean age 51.6 +/- 8.1 years) without other risk factors. Twenty-four normal subjects were used as controls for vascular reactivity. Subjects randomly received RW, 250 ml/day, or purple grape juice (GJ), 500 ml/day, for 14 days with an equal wash-out period. At baseline, all 16 subjects were hypercholesterolemic (mean LDL = 181.0 +/- 28.7 mg/dl) but HDL, triglycerides, glucose, adhesion molecules, and platelet function were within normal limits. Brachial artery flow-mediated dilation was significantly decreased compared to controls (9.0 +/- 7.1 vs 12.1 +/- 4.5%; P effect on either molecule. No significant alterations were observed in plasma lipids, glucose or platelet aggregability with RW or GJ. Both RW and GJ similarly improved flow-mediated dilation, but RW also enhanced endothelium-independent vasodilation in hypercholesterolemic patients despite the increased plasma cholesterol. Thus, we conclude that GJ may protect against coronary artery disease without the additional negative effects of alcohol despite the gender.

Reactive power management and voltage control in deregulated power markets

Science.gov (United States)

Spangler, Robert G.

The research that is the subject of this dissertation is about the management of reactive power and voltage support in the wholesale open access power markets in the United States (US). The purpose of this research is to place decisions about open access market structures, as they relate to reactive power and voltage control, on a logical and consistent economic basis, given the engineering needs of a commercial electric power system. An examination of the electricity markets operating in the US today reveals that current approaches to reactive power management and voltage support are extensions of those based on historical, regulated monopoly electric service. A case for change is built by first looking at the subject of reactive power from an engineering viewpoint and then from an economic perspective. Ultimately, a set of market rules for managing reactive power and voltage support is proposed. The proposal suggests that cost recovery for static and dynamic VARs is appropriately accomplished through the regulated transmission cost of service. Static VAR cost recovery should follow traditional rate recovery methodologies. In the case of dynamic VARs, this work provides a methodology based on the microeconomic theory of the firm for determining such cost. It further suggests that an operational strategy that reduces and limits the use of dynamic VARs, during normal operations, is appropriate. This latter point leads to an increase in the fixed cost of the transmission network but prevents price spikes and short supply situations from affecting, or being affected by, the reactive capability limitations associated with dynamic VARs supplied from synchronous generators. The rules are consistent with a market structure that includes competitive generation and their application will result in the communication of a clear understanding of the responsibilities, related to voltage control, of each type of market entity. In this sense, their application will contribute to

Effect of reactivity insertion rate on peak power and temperatures in swimming pool type research reactor

International Nuclear Information System (INIS)

Khan, L.A.; Jabbar, A.; Anwar, A.R.; Ahmad, N.

1998-01-01

It is essential to study the reactor behavior under different accidental conditions and take proper measures for its safe operation. We have studied the effect of reactivity insertion, with and without scram conditions, on peak power and temperatures of fuel, cladding and coolant in typical swimming pool type research reactor. The reactivity ranging from 1 $ to 2 $ and insertion times from 0.25 to 1 second have been considered. The computer code PARET has been used and results are presented in this article. (author)

Improvements of the base bleed effect using reactive particles

Energy Technology Data Exchange (ETDEWEB)

Bournot, Herve; Daniel, Eric [Polytech' Marseille, IUSTI UMR CNRS 6595, 5, rue E. Fermi, Technopole de Chateau Gombert, 13453 Marseille cedex 13 (France); Cayzac, Roxan [Giat Industries, 7, Route de Guerry, F-18023 Bourges cedex (France)

2006-11-15

A numerical study of the base drag reduction of axisymmetric body projectiles in supersonic flight using a base bleed injection is presented in this paper. Unsteady computations of compressible viscous flow have been achieved in order to investigate the coupled effect of the bleed temperature and the bleed mass flow rate on the base pressure. The idea developed in the study, consists in the addition of metallic particles in the propellant composition used to provide the additional mass injected in order to obtain the lowest base drag. Indeed, for a low mass addition, a significant increase of the mixture energy is expected due to the particles combustion. Base flow with reactive two-phase injection is then simulated. Results show the ability of the method to describe such flows and the efficiency of the particles combustion to increase the base bleed reducing drag effect. (author)

Ultraviolet enhanced reactivation of a human virus: effect of delayed infection

International Nuclear Information System (INIS)

Bockstahler, L.E.; Lytle, C.D.; Stafford, J.E.; Haynes, K.F.

1976-01-01

The ability of UV-irradiated herpes simplex virus to form plaques was examined in monolayers of CV-1 monkey kidney cells preexposed to UV radiation at different intervals before virus assay. From analysis of UV reactivation (Weigle reactivation) curves it was found that as the interval between cell UV irradiation (0-20 J/m 2 ) and initiation of the virus assay was increased over a period of five days, (1) the capacity of the cells to support unirradiated virus plaque formation, which was decreased immediately following UV exposure of the monolayers, increased and returned to approximately normal levels within five days, and (2) at five days an exponential increase was observed in the relative plaque formation of irradiated virus as a function of UV dose to the monolayers. For high UV fluence (20 J/m 2 ) to the cells, the relative plaque formation by the UV-irradiated virus at five days was about 10-fold higher than that obtained from assay on unirradiated cells. This enhancement in plaque formation is interpreted as a delayed expression of Weigle reactivation. The amount of enhancement resulting from this delayed reactivation was several fold greater than that produced by the Weigle reactivation which occurred when irradiated herpes virus was assayed immediately following cell irradiation

C-reactive protein a better indicator of inflammation after third molar ...

African Journals Online (AJOL)

operative pain and pre-operative levels of C-reactive and post-operative pain and swelling in impacted third molar surgery. Materials and Methods: In this prospective study subjects were patients indicated for mandibular third molar extraction.

The Interactive Effects of Stressful Family Life Events and Cortisol Reactivity on Adolescent Externalizing and Internalizing Behaviors

Science.gov (United States)

Steeger, Christine M.; Cook, Emily C.; Connell, Christian M.

2016-01-01

This study investigated the associations between stressful family life events and adolescent externalizing and internalizing behaviors, and the interactive effects of family life events and cortisol reactivity on problem behaviors. In a sample of 100 mothers and their adolescents (M age = 15.09; SD age = 0.98; 68% girls), adolescent cortisol reactivity was measured in response to a mother-adolescent conflict interaction task designed to elicit a stress response. Mothers reported on measures of family life events and adolescent problem behaviors. Results indicated that a heightened adolescent cortisol response moderated the relations between stressful family life events and both externalizing and internalizing behaviors. Results support context-dependent theoretical models, suggesting that for adolescents with higher cortisol reactivity (compared to those with lower cortisol reactivity), higher levels of stressful family life events were associated with greater problem behaviors, whereas lower levels of stressful family life events were related to fewer problem behaviors. PMID:26961703

Reactivity anomalies in the FFTF [Fast Flux Test Facility

International Nuclear Information System (INIS)

Knutson, B.J.; Harris, R.A.

1987-04-01

Experience using an automated core reactivity monitoring technique at the Fast Flux Test Facility (FFTF) through eight operating cycles is described. This technique relies on comparing predicted to measured rod positions to detect any anomalous (or unpredicted) core reactivity changes. Reactivity worth predictions of core state changes (e.g., temperature and irradiation changes) and compensating control rod movements are required for the rod position comparison. A substantial data base now exists to evaluate changes in temperature reactivity feedback effects operational in the FFTF, rod worth changes due to core loading, temperature and irradiation effects and burnup effects associated with transmutation of fuel materials. This report summarizes preliminary work of correlating zero power and at-power rod worth measurement data, calculated burnup rates and rod worths using the latest ENDF/B-V cross section set for each cycle to evaluate the prediction models and attempt to resolve observed reactivity anomalies. 2 figs., 2 tabs

Effects of prenatal stress and emotional reactivity of the mother on emotional and cognitive abilities in lambs.

Science.gov (United States)

Coulon, Marjorie; Nowak, Raymond; Andanson, Stephane; Petit, Bérengère; Lévy, Frédéric; Boissy, Alain

2015-07-01

Consequences of prenatal stress on emotional reactivity and cognitive abilities in offspring are under-documented in precocial mammals. Here, we investigated to what extent emotional reactivity, judgment bias and spatial learning abilities of lambs are affected by chronic stress during late pregnancy and by their dams' emotional reactivity. The 20 highest-responsive (HR) and 20 lowest-responsive (LR) ewes from a population of 120 Romane ewes were selected according to their pre-mating reactivity to social isolation in a new environment. Over the final third of pregnancy, 10 HR ewes and 10 LR ewes were exposed daily to various unpredictable aversive events such as restraint, mixing groups and transport while the other 20 selected ewes were not. In a human and an object test, prenatally-stressed lambs were more fearful than control lambs, but the prenatal stress effect was moderated by the reactivity of the mothers: prenatally-stressed lambs from ewes with high emotional reactivity were more affected. Prenatally-stressed lambs did not perform as well as control lambs in a maze test and showed pessimistic-like judgment in a cognitive bias test. Prenatally-stressed lambs were thus characterized by a negative affective state with increased fear reactions and impaired cognitive evaluation. The development of negative moods could have long-lasting consequences on the coping strategies of the lambs in response to their rearing conditions. © 2015 Wiley Periodicals, Inc.

Effects of direct injection timing and blending ratio on RCCI combustion with different low reactivity fuels

International Nuclear Information System (INIS)

Benajes, Jesús; Molina, Santiago; García, Antonio; Monsalve-Serrano, Javier

2015-01-01

Highlights: • E85 requires notable lower premixed energy ratios to achieve a stable combustion. • E10-95 leads to shorter and advanced combustion with higher maximum RoHR peaks. • E20-95, E10-98 and E10-95 reach EURO VI NOx and soot levels for all the engine loads. • E10-95 allows a significant reduction in HC and CO emissions. - Abstract: This work investigates the effects of the direct injection timing and blending ratio on RCCI performance and engine-out emissions at different engine loads using four low reactivity fuels: E10-95, E10-98, E20-95 and E85 (port fuel injected) and keeping constant the same high reactivity fuel: diesel B7 (direct injected). The experiments were conducted using a heavy-duty single-cylinder research diesel engine adapted for dual-fuel operation. All the tests were carried out at 1200 rpm. To assess the blending ratio effect, the total energy delivered to the cylinder coming from the low reactivity fuel was kept constant for the different fuel blends investigated by adjusting the low reactivity fuel mass as required in each case. In addition, a detailed analysis of the air/fuel mixing process has been developed by means of a 1-D in-house developed spray model. Results suggest that notable higher diesel amount is required to achieve a stable combustion using E85. This fact leads to higher NOx levels and unacceptable ringing intensity. By contrast, EURO VI NOx and soot levels are fulfilled with E20-95, E10-98 and E10-95. Finally, the higher reactivity of E10-95 results in a significant reduction in CO and HC emissions, mainly at low load

Effect of mechanical activation on structure changes and reactivity in further chemical modification of lignin.

Science.gov (United States)

Zhao, Xiaohong; Zhang, Yanjuan; Hu, Huayu; Huang, Zuqiang; Yang, Mei; Chen, Dong; Huang, Kai; Huang, Aimin; Qin, Xingzhen; Feng, Zhenfei

2016-10-01

Lignin was treated by mechanical activation (MA) in a customized stirring ball mill, and the structure and reactivity in further esterification were studied. The chemical structure and morphology of MA-treated lignin and the esterified products were analyzed by chemical analysis combined with UV/vis spectrometer, FTIR,NMR, SEM and particle size analyzer. The results showed that MA contributed to the increase of aliphatic hydroxyl, phenolic hydroxyl, carbonyl and carboxyl groups but the decrease of methoxyl groups. Moreover, MA led to the decrease of particle size and the increase of specific surface area and roughness of surface in lignin. The reactivity of lignin was enhanced significantly for the increase of hydroxyl content and the improvement of mass transfer in chemical reaction caused by the changes of molecular structure and morphological structure. The process of MA is green and simple, and is an effective method for enhancing the reactivity of lignin. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessment of reactivity of three treponemal tests in non-treponemal non-reactive cases from sexually transmitted diseases clinic, antenatal clinic, integrated counselling and testing centre, other different outdoor patient departments/indoor patients of a tertiary care centre and peripheral health clinic attendees

Directory of Open Access Journals (Sweden)

M Bala

2013-01-01

Full Text Available In India, many state reference centres for sexually transmitted infections perform only a single screening assay for syphilis diagnosis. In this study, Treponema pallidum haemagglutination (TPHA was performed on 1115 Venereal Disease Research Laboratory (VDRL/rapid plasma regain (RPR non-reactive and 107 reactive sera out of 10,489 tested by VDRL/RPR according to the National AIDS Control Organisation syphilis testing protocol. A total of 47 Specimens reactive in TPHA and non-reactive with VDRL test were subjected to fluorescent treponemal antibody absorption and enzyme-immunoassay. Seroprevalence considering both VDRL and TPHA positivity was highest (4.4% in sexually transmitted diseases clinic attendees than in other subject groups. Positivity by two treponemal tests in 24 (2.2% cases non-reactive by VDRL/RPR was representative of the fully treated patients or latent or late syphilis cases. The findings highlight that a suitable treponemal confirmatory test should be performed in all the diagnostic laboratories.

Emotional reactivity to social stimuli in patients with eating disorders.

Science.gov (United States)

Tapajóz P de Sampaio, Fernanda; Soneira, Sebastian; Aulicino, Alfredo; Harris, Paula; Allegri, Ricardo Francisco

2015-10-30

Patients with eating disorders often display a wide range of difficulties in psychosocial functioning. Most of the studies on this subject have focused on theory of mind; however, little is known about the subjective emotional reactivity of patients to social situations. The aim of this study was to evaluate the patients' perceptions of their own emotions when viewing pictures with social content. Emotional reactivity was assessed in 85 women (29 with anorexia nervosa, 28 with bulimia nervosa, and 28 healthy controls) by using 30 images from the International Affective Picture System. Images were divided into categories based on its social content and its emotional valence. The emotional response was evaluated through the Self-Assessment Manikin. Patients with bulimia nervosa presented higher arousal and lower control when viewing images with social content of pleasant, unpleasant, and neutral valence. Patients with anorexia nervosa reported higher arousal and lower control only for social images with neutral valence. There were no differences between groups for the control images. The finding of specific differences in emotional reactivity to pictures with social content contributes to a more accurate understanding of the difficulties of patients in social situations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of Acute Hypoxia on Post-Exercise Parasympathetic Reactivation in Healthy Men

Science.gov (United States)

Al Haddad, Hani; Mendez-Villanueva, Alberto; Bourdon, Pitre C.; Buchheit, Martin

2012-01-01

In this study we assessed the effect of acute hypoxia on post-exercise parasympathetic reactivation inferred from heart rate (HR) recovery (HRR) and HR variability (HRV) indices. Ten healthy males participated in this study. Following 10 min of seated rest, participants performed 5 min of submaximal running at the speed associated with the first ventilatory threshold (Sub) followed by a 20-s all-out supramaximal sprint (Supra). Both Sub and Supra runs were immediately followed by 15 min of seated passive recovery. The resting and exercise sequence were performed in both normoxia (N) and normobaric hypoxia (H; FiO2 = 15.4%). HRR indices (e.g., heart beats recovered in the first minute after exercise cessation, HRR60s) and vagal-related HRV indices [i.e., natural logarithm of the square root of the mean of the sum of the squared differences between adjacent normal R–R intervals (Ln rMSSD)] were calculated for both conditions. Difference in the changes between N and H for all HR-derived indices were also calculated for both Sub and Supra. HRR60s was greater in N compared with H following Sub only (60 ± 14 vs. 52 ± 19 beats min−1, P = 0.016). Ln rMSSD was greater in N compared with H (post Sub: 3.60 ± 0.45 vs. 3.28 ± 0.44 ms in N and H, respectively, and post Supra: 2.66 ± 0.54 vs. 2.65 ± 0.63 ms, main condition effect P = 0.02). When comparing the difference in the changes, hypoxia decreased HRR60s (−14.3% ± 17.2 vs. 5.2% ± 19.3; following Sub and Supra, respectively; P = 0.03) and Ln rMSSD (−8.6% ± 7.0 vs. 2.0% ± 13.3, following Sub and Supra, respectively; P = 0.08, Cohen’s effect size = 0.62) more following Sub than Supra. While hypoxia may delay parasympathetic reactivation following submaximal exercise, its effect is not apparent following supramaximal exercise. This may suggest that the effect of blood O2 partial pressure on parasympathetic reactivation is limited

[Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants].

Science.gov (United States)

Gutiérrez, Liliana; García, José R; Rincón, María de Jesús; Ceballos, Guillermo M; Olivares, Ivonne M

2015-07-06

Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants. Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined. Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 μM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 μM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments. We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Effects of moderation level on core reactivity and. neutron fluxes in natural uranium fueled and heavy water moderated reactors

International Nuclear Information System (INIS)

Khan, M.J.; Aslam; Ahmad, N.; Ahmed, R.; Ahmad, S.I.

2005-01-01

The neutron moderation level in a nuclear reactor has a strong influence on core multiplication, reactivity control, fuel burnup, neutron fluxes etc. In the study presented in this article, the effects of neutron moderation level on core reactivity and neutron fluxes in a typical heavy water moderated nuclear research reactor is explored and the results are discussed. (author)

Neural Network Based Reactive Navigation for Mobile Robot in Dynamic Environment

Czech Academy of Sciences Publication Activity Database

Krejsa, Jiří; Věchet, S.; Ripel, T.

2013-01-01

Roč. 198, č. 2013 (2013), s. 108-113 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : mobile robot * reactive navigation * artificial neural networks Subject RIV: JD - Computer Applications, Robotics

Effect of chemical degradation on fluxes of reactive compounds – a study with a stochastic Lagrangian transport model

Directory of Open Access Journals (Sweden)

J. Rinne

2012-06-01

Full Text Available In the analyses of VOC fluxes measured above plant canopies, one usually assumes the flux above canopy to equal the exchange at the surface. Thus one assumes the chemical degradation to be much slower than the turbulent transport. We used a stochastic Lagrangian transport model in which the chemical degradation was described as first order decay in order to study the effect of the chemical degradation on above canopy fluxes of chemically reactive species. With the model we explored the sensitivity of the ratio of the above canopy flux to the surface emission on several parameters such as chemical lifetime of the compound, friction velocity, stability, and canopy density. Our results show that friction velocity and chemical lifetime affected the loss during transport the most. The canopy density had a significant effect if the chemically reactive compound was emitted from the forest floor. We used the results of the simulations together with oxidant data measured during HUMPPA-COPEC-2010 campaign at a Scots pine site to estimate the effect of the chemistry on fluxes of three typical biogenic VOCs, isoprene, α-pinene, and β-caryophyllene. Of these, the chemical degradation had a major effect on the fluxes of the most reactive species β-caryophyllene, while the fluxes of α-pinene were affected during nighttime. For these two compounds representing the mono- and sesquiterpenes groups, the effect of chemical degradation had also a significant diurnal cycle with the highest chemical loss at night. The different day and night time loss terms need to be accounted for, when measured fluxes of reactive compounds are used to reveal relations between primary emission and environmental parameters.

Childhood trauma, psychosis liability and social stress reactivity: a virtual reality study.

Science.gov (United States)

Veling, W; Counotte, J; Pot-Kolder, R; van Os, J; van der Gaag, M

2016-12-01

Childhood trauma is associated with higher risk for mental disorders, including psychosis. Heightened sensitivity to social stress may be a mechanism. This virtual reality study tested the effect of childhood trauma on level of paranoid ideations and distress in response to social stress, in interaction with psychosis liability and level of social stress exposure. Seventy-five individuals with higher psychosis liability (55 with recent onset psychotic disorder and 20 at ultra-high risk for psychosis) and 95 individuals with lower psychosis liability (42 siblings and 53 controls) were exposed to a virtual café in five experiments with 0-3 social stressors (crowded, other ethnicity and hostility). Paranoid ideation was measured after each experiment. Subjective distress was self-rated before and after experiments. Multilevel random regression analyses were used to test main effects of childhood trauma and interaction effects. Childhood trauma was more prevalent in individuals with higher psychosis liability, and was associated with higher level of (subclinical) psychotic and affective symptoms. Individuals with a history of childhood trauma responded with more subjective distress to virtual social stress exposures. The effects of childhood trauma on paranoia and subjective distress were significantly stronger when the number of virtual environmental stressors increased. Higher psychosis liability increased the effect of childhood trauma on peak subjective distress and stress reactivity during experiments. Childhood trauma is associated with heightened social stress sensitivity and may contribute to psychotic and affective dysregulation later in life, through a sensitized paranoid and stress response to social stressors.

The effect of aging on the dynamics of reactive and proactive cognitive control of response interference

Directory of Open Access Journals (Sweden)

Ling Xiang

2016-11-01

Full Text Available A prime-target interference task was used to investigate the effects of cognitive aging on reactive and proactive control in which frequency confounds and feature repetitions were eliminated from the cognitive control measures. We used distributional analyses to explore the dynamics of the two control functions by distinguishing the strength of incorrect response capture and the efficiency of suppression control. For reactive control, within-trial conflict control and between-trial conflict adaption were analyzed. The statistical analysis showed that there were no reliable between-trial conflict adaption effects for both young and older adults. For within-trial conflict control, the results revealed that older adults showed larger interference effects on mean RT and mean accuracy. Distributional analyses showed that the decline mainly stemmed from inefficient suppression rather than from stronger incorrect responses. For proactive control, older adults showed comparable proactive conflict resolution than young adults on mean RT and mean accuracy. Distributional analyses showed older adults were as effective as younger adults in adjusting their responses to minimize automatic response capture and actively suppress the direct response activation based on congruency proportion information. The results suggest that older adults were less proficient at suppressing interference after conflict was detected but can anticipate and prevent inference in response to congruency proportion manipulation. The results challenge earlier views that older adults have selective deficits in proactive control but are spared in reactive control.

Effects of drying methods on the low temperature reactivity of Victorian brown coal to oxygen

Energy Technology Data Exchange (ETDEWEB)

Unal, S.; Wood, D.G.; Harris, I.J. (University of Marmara, Istanbul (Turkey). Ataturk Faculty of Education, Division of Science Education)

1992-02-01

The effects of air drying and thermal dewatering on the low temperature oxygen reactivity of Victorian brown coal have been investigated in the temperature range 35-55{degree}C and at 100 kPa oxygen pressure using coal samples ground to {lt} 100 mesh. An attempt has also been made to relate the low temperature oxygen reactivity of the coal to its free radical concentration as measured prior to oxidation. Two rate models, the Schmidt and Winmill models, have been adapted to include the initial free radical concentration of the coal samples as the drying method sensitivity parameter in lieu of the concentration of oxygen-reactive sites in the coal material. The experimental results show that air drying, which reduces the free radical concentration of the coal, causes a decline in its oxygen reactivity whereas thermal dewatering, which causes an increase in the free radical concentration of the coal, enhances its oxygen reactivity. Air drying does not affect the distribution of the consumed oxygen in the oxidation products. A difference is observed in the case of the thermally dewatered coal samples. The correlation of the two rate models adopted is considered equally satisfactory. However, only the values obtained for the two activation energies in the Winmill model reflect the changes caused by thermal dewatering in the oxidation pattern of the coal. The activation energy values obtained from the two models are within the range of those quoted in the literature for the abstraction of hydrogen from various arene structures by free radicals. 35 refs., 10 figs., 8 tabs.

Absorption and subjective effects of caffeine from coffee, cola and capsules.

Science.gov (United States)

Liguori, A; Hughes, J R; Grass, J A

1997-11-01

Coffee is often perceived as producing greater pharmacological effects than cola. The present study compared the magnitude and rapidity of peak caffeine levels and subjective effects between coffee and cola. Thirteen users of both coffee and cola (mean daily caffeine consumption = 456 mg) ingested 400 mg caffeine via 12 oz unsweetened coffee, 24 oz sugar-free cola or 2 capsules in a random, double-blind, placebo-controlled, within-subjects design. Subjects provided a saliva sample and completed subjective effect scales 15 min before and 30, 60, 90, 120, 180 and 240 min after ingestion. Mean peak saliva caffeine levels did not differ between coffee (9.7 +/- 1.2 micrograms/ml) and cola (9.8 +/- 0.9 micrograms/ml) and appeared to be greater with these beverages than with the capsule (7.8 +/- 0.6 micrograms/ml; p = NS). Saliva caffeine levels peaked at similar times for coffee (42 +/- 5 min) and cola (39 +/- 5 min) but later for capsule (67 +/- 7 min; p = 0.004). There was no main effect of vehicle or interaction of vehicle and drug on magnitude of peak effect or time to peak increase on self-report scales. In summary, peak caffeine absorption, time to peak absorption, and subjective effects do not appear to be influenced by cola vs. coffee vehicle. Perceived differences in the effects of coffee vs. cola may be due to differences in dose, time of day, added sweetener, environmental setting or contingencies.

Appetitive Motivation and Negative Emotion Reactivity among Remitted Depressed Youth

Science.gov (United States)

Hankin, Benjamin L.; Wetter, Emily K.; Flory, Kate

2012-01-01

Depression has been characterized as involving altered appetitive motivation and emotional reactivity. Yet no study has examined objective indices of emotional reactivity when the appetitive/approach system is suppressed in response to failure to attain a self-relevant goal and desired reward. Three groups of youth (N = 98, ages 9–15; remitted depressed, n = 34; externalizing disordered without depression, n = 30, and healthy controls, n = 34) participated in a novel reward striving task designed to activate the appetitive/approach motivation system. Objective facial expressions of emotion were videotaped and coded throughout both failure (i.e., nonreward) and control (success and reward) conditions. Observational coding of facial expressions as well as youths’ subjective emotion reports showed that the remitted depressed youth specifically exhibited more negative emotional reactivity to failure in the reward striving task, but not the control condition. Neither externalizing disordered (i.e., ADHD, CD, and/ or ODD) nor control youth displayed greater negative emotional reactivity in either the failure or control condition. Findings suggest that depression among youth is related to dysregulated appetitive motivation and associated negative emotional reactivity after failing to achieve an important, self-relevant goal and not attaining reward. These deficits in reward processing appear to be specific to depression as externalizing disordered youth did not display negative emotional reactivity to failure after their appetitive motivation system was activated. PMID:22901275

Differential pharmacological effects on brain reactivity and plasticity in Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Anna-Katharine eBrem

2013-10-01

Full Text Available Acetylcholinesterase inhibitors (AChEI are the most commonly prescribed monotherapeutic medications for Alzheimer’s disease (AD. However, their underlying neurophysiological effects remain largely unknown.We investigated the effects of monotherapy (AChEI and combination therapy (AChEI and memantine on brain reactivity and plasticity. Patients treated with monotherapy (AChEI (N=7 were compared to patients receiving combination therapy (COM (N=9 and a group of age-matched, healthy controls (HC (N=13. Cortical reactivity and plasticity of the motor cortex (MC were examined using transcranial magnetic stimulation (TMS. Cognitive functions were assessed with the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog, activities of daily living with the ADCS-ADL. In addition we assessed the degree of brain atrophy by measuring brain-scalp distances in seven different brain areas.Patient groups differed in resting motor threshold and brain atrophy, with COM showing a lower motor threshold but less atrophy than AChEI. COM showed similar plasticity effects as the HC group, while plasticity was reduced in AChEI. Long-interval intracortical inhibition (LICI was impaired in both patient groups when compared to HC. ADAS-Cog scores were positively correlated with LICI measures and with brain atrophy, specifically in the left IPL.AD patients treated with mono- or combination therapy show distinct neurophysiological patterns. Further studies should investigate whether these measures might serve as biomarkers of treatment response and whether they could guide other therapeutic interventions.

Validation of moderator-level reactivity coefficient using station data

Energy Technology Data Exchange (ETDEWEB)

Younis, M.; Martchouk, I., E-mail: mohamed.younis@amecfw.com, E-mail: iouri.martchouk@amecfw.com [Amec Foster Wheeler, Toronto, ON (Canada); Buchan, P.D., E-mail: david.buchan@opg.com [Ontario Power Generation, Pickering, ON (Canada)

2015-07-01

The reactivity effect due to variations in the moderator level has been recognized as a reactor physics phenomenon of importance during normal operation and accident analysis. The moderator-level reactivity coefficient is an important parameter in safety analysis of CANDU reactors, e.g., during Loss of Moderator Heat Sink as well as in the simulation of Reactor Regulating System action in CANDU reactors that use moderator level for reactivity control. This paper presents the results of the validation exercise of the reactor-physics toolset using the measurements performed in Pickering Unit 4 in 2003. The capability of the code suite of predicting moderator-level reactivity effect was tested by comparing measured and predicted reactor-physics parameters. (author)

Psychophysiology of proactive and reactive relational aggression.

Science.gov (United States)

Murray-Close, Dianna; Holterman, Leigh Ann; Breslend, Nicole L; Sullivan, Alexandra

2017-12-01

This study investigated the joint effects of parasympathetic and sympathetic nervous system reactivity to social and non-social stressors on proactive (i.e., goal-directed, unemotional) and reactive (i.e., emotional, impulsive) functions of relational aggression. Two hundred and forty-seven (M age =18.77years) participants completed a series of stressor tasks while their sympathetic arousal (i.e., skin conductance) and parasympathetic arousal (i.e., respiratory sinus arrhythmia) were assessed. Participants also provided self-reports of their aggressive behavior. In the standardized social stressor only, physiological reactivity was related to aggression, such that respiratory sinus arrhythmia augmentation predicted proactive relational aggression whereas heightened skin conductance reactivity predicted reactive relational aggression. Finally, in the context of low skin conductance reactivity, respiratory sinus arrhythmia augmentation was related to heightened proactive and reactive aggression, whereas respiratory sinus arrhythmia withdrawal was protective. Results suggest that the benefits hypothesized to accompany respiratory sinus arrhythmia withdrawal may only occur among individuals with low "fight or flight" stress responses. Findings extend research on the physiological indicators of aggression to relational aggression, and highlight the importance of assessing functions of aggression, as well as physiological reactivity to multiple stressors. Copyright © 2017 Elsevier B.V. All rights reserved.

Digital reactivity meter

International Nuclear Information System (INIS)

Akkus, B.; Anac, H.; Alsan, S.; Erk, S.

1991-01-01

Nowadays, various digital methods making use of microcomputers for neutron detector signals and determining the reactivity by numerical calculations are used in reactor control systems in place of classical reactivity meters. In this work, a calculation based on the ''The Time Dependent Transport Equation'' has been developed for determining the reactivity numerically. The reactivity values have been obtained utilizing a computer-based data acquisition and control system and compared with the analog reactivity meter values as well as the values calculated from the ''Inhour Equation''

The effect of lipid peroxidation products on reactive oxygen species formation and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages

Czech Academy of Sciences Publication Activity Database

Ambrožová, Gabriela; Pekarová, Michaela; Lojek, Antonín

2011-01-01

Roč. 25, č. 1 (2011), s. 145-152 ISSN 0887-2333 R&D Projects: GA MŠk(CZ) OC08058; GA ČR(CZ) GA524/08/1753 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : lipid peroxidation products * reactive oxygen species * nitric oxide Subject RIV: BO - Biophysics Impact factor: 2.775, year: 2011

Substrate temperature effects on reactively sputtered Cr2O3/n-Si heterojunctions

International Nuclear Information System (INIS)

Ocak, Yusuf Selim; Genisel, Mustafa Fatih; Issa, Ali Ahmed; Tombak, Ahmet; Kilicoglu, Tahsin

2016-01-01

To see the effects of substrate temperature on Cr 2 O 3 /n-Si heterojunctions, Cr 2 O 3 thin films were formed on n-Si and glass substrates at 40, 150 and 250 °C by radio frequency (RF) reactive sputtering technique. High purity Cr was used as target and oxygen was used as reactive gas. Optical properties of Cr 2 O 3 /n-Si thin films were analyzed using UV-vis data. The band gaps of the films were compared. The electrical properties of Cr 2 O 3 /n-Si heterojunction were tested by their current voltage ( I-V ) measurements in dark. It was observed that the heterojunction which was fabricated by forming Cr 2 O 3 thin film at 250 °C gave better rectification. The characteristic electrical parameters such as barrier height, ideality factor and series resistance were calculated by using its I-V data. The influence of light intensity on photovoltaic effect behavior of the device was also calculated, finally the barrier height value of the structure obtained from capacitance-voltage ( C-V ) data were compared with the one calculated from I-V measurements. (paper)

On the effects of the reactive terms in the Boltzmann equation

Directory of Open Access Journals (Sweden)

C. J. Zamlutti

Full Text Available The effects of the production and loss mechanisms that affect the Boltzmann equations are considered by the inclusion of a reactive term. The necessary elements to develop a proper form for this term are revised and the current trends analyzed. Although no accurate theoretical treatment of the problem is possible due to the many body nature of it, important relations can be derived which, besides being representative of the quantitative aspects of the matter, are illustrative of the qualitative features of the phenomenon. The overall procedure is detailed in this revision.

A Reactive Balance Rating Method that Correlates with Kinematics after Trip-Like Perturbations on a Treadmill and Fall Risk Among Residents of Older Adult Congregate Housing.

Science.gov (United States)

Madigan, Michael L; Aviles, Jessica; Allin, Leigh J; Nussbaum, Maury A; Alexander, Neil B

2018-04-16

A growing number of studies are using modified treadmills to train reactive balance after trip-like perturbations that require multiple steps to recover balance. The goal of this study was thus to develop and validate a low-tech reactive balance rating method in the context of trip-like treadmill perturbations to facilitate the implementation of this training outside the research setting. Thirty-five residents of five senior congregate housing facilities participated in the study. Subjects completed a series of reactive balance tests on a modified treadmill from which the reactive balance rating was determined, along with a battery of standard clinical balance and mobility tests that predict fall risk. We investigated the strength of correlation between the reactive balance rating and reactive balance kinematics. We compared the strength of correlation between the reactive balance rating and clinical tests predictive of fall risk, with the strength of correlation between reactive balance kinematics and the same clinical tests. We also compared the reactive balance rating between subjects predicted to be at a high or low risk of falling. The reactive balance rating was correlated with reactive balance kinematics (Spearman's rho squared = .04 - .30), exhibited stronger correlations with clinical tests than most kinematic measures (Spearman's rho squared = .00 - .23), and was 42-60% lower among subjects predicted to be at a high risk for falling. The reactive balance rating method may provide a low-tech, valid measure of reactive balance kinematics, and an indicator of fall risk, after trip-like postural perturbations.

A Conformational Change in C-Reactive Protein Enhances Leukocyte Recruitment and Reactive Oxygen Species Generation in Ischemia/Reperfusion Injury

Directory of Open Access Journals (Sweden)

Jan R. Thiele

2018-04-01

Full Text Available IntroductionC-reactive protein circulates as a pentameric protein (pCRP. pCRP is a well-established diagnostic marker as plasma levels rise in response to tissue injury and inflammation. We recently described pro-inflammatory properties of CRP, which are mediated by conformational changes from pCRP to bioactive isoforms expressing pro-inflammatory neo-epitopes [pCRP* and monomeric C-reactive protein (mCRP]. Here, we investigate the role of CRP isoforms in renal ischemia/reperfusion injury (IRI.MethodsRat kidneys in animals with and without intraperitoneally injected pCRP were subjected to IRI by the time of pCRP exposure and were subsequently analyzed for monocyte infiltration, caspase-3 expression, and tubular damage. Blood urea nitrogen (BUN was analyzed pre-ischemia and post-reperfusion. CRP effects on leukocyte recruitment were investigated via intravital imaging of rat-striated muscle IRI. Localized conformational CRP changes were analyzed by immunohistochemistry using conformation specific antibodies. 1,6-bis(phosphocholine-hexane (1,6-bisPC, which stabilizes CRP in its native pentameric form was used to validate CRP effects. Leukocyte activation was assessed by quantification of reactive oxygen species (ROS induction by CRP isoforms ex vivo and in vitro through electron spin resonance spectroscopy. Signaling pathways were analyzed by disrupting lipid rafts with nystatin and subsequent ROS detection. In order to confirm the translational relevance of our findings, biopsies of microsurgical human free tissue transfers before and after IRI were examined by immunofluorescence for CRP deposition and co-localization of CD68+ leukocytes.ResultsThe application of pCRP aggravates tissue damage in renal IRI. 1,6-bisPC reverses these effects via inhibition of the conformational change that leads to exposure of pro-inflammatory epitopes in CRP (pCRP* and mCRP. Structurally altered CRP induces leukocyte–endothelial interaction and induces ROS

Subjective qualities of memories associated with the picture superiority effect in schizophrenia.

Science.gov (United States)

Huron, Caroline; Danion, Jean-Marie; Rizzo, Lydia; Killofer, Valérie; Damiens, Annabelle

2003-02-01

Patients with schizophrenia (n = 24) matched with 24 normal subjects were presented with both words and pictures. On a recognition memory task, they were asked to give remember, know, or guess responses to items that were recognized on the basis of conscious recollection, familiarity, or guessing, respectively. Compared with normal subjects, patients exhibited a lower picture superiority effect selectively related to remember responses. Unlike normal subjects, they did not exhibit any word superiority effect in relation to guess responses; this explains why the overall picture superiority effect appeared to be intact. These results emphasize the need to take into account the subjective states of awareness when analyzing memory impairments in schizophrenia.

Substation Reactive Power Regulation Strategy

Science.gov (United States)

Zhang, Junfeng; Zhang, Chunwang; Ma, Daqing

2018-01-01

With the increasing requirements on the power supply quality and reliability of distribution network, voltage and reactive power regulation of substations has become one of the indispensable ways to ensure voltage quality and reactive power balance and to improve the economy and reliability of distribution network. Therefore, it is a general concern of the current power workers and operators that what kind of flexible and effective control method should be used to adjust the on-load tap-changer (OLTC) transformer and shunt compensation capacitor in a substation to achieve reactive power balance in situ, improve voltage pass rate, increase power factor and reduce active power loss. In this paper, based on the traditional nine-zone diagram and combining with the characteristics of substation, a fuzzy variable-center nine-zone diagram control method is proposed and used to make a comprehensive regulation of substation voltage and reactive power. Through the calculation and simulation of the example, this method is proved to have satisfactorily reconciled the contradiction between reactive power and voltage in real-time control and achieved the basic goal of real-time control of the substation, providing a reference value to the practical application of the substation real-time control method.

The Effects of Objective and Subjective Socioeconomic Status on Subjective Well-Being among Rural-to-Urban Migrants in China: The Moderating Role of Subjective Social Mobility

Directory of Open Access Journals (Sweden)

Silin Huang

2017-05-01

Full Text Available Although previous investigations have agreed that Chinese rural-to-urban migrants’ socioeconomic status (SES increases with their migration, the association between SES and subjective well-being is uncertain. To address this research gap, the present study proposed that the association between objective SES and subjective well-being is mediated by subjective SES. This model was tested with a sample of 432 Chinese rural-to-urban migrants. The results indicate a significant association between objective SES and subjective well-being and a partial mediating effect of subjective SES. Furthermore, subjective social mobility, which is one’s expectation about the possibility to move upward in the social hierarchy, was found to moderate both the direct path from objective SES to subjective well-being and the indirect path from subjective SES to subjective well-being. These findings suggest that Chinese rural-to-urban migrants gained in subjective well-being not only because of direct financial achievement but also because of their perceptions and beliefs about their relative social status.

Steam-chemical reactivity for irradiated beryllium

Energy Technology Data Exchange (ETDEWEB)

Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

1998-01-01

This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

Does reactivation trigger episodic memory change? A meta-analysis.

Science.gov (United States)

Scully, Iiona D; Napper, Lucy E; Hupbach, Almut

2017-07-01

According to the reconsolidation hypothesis, long-term memories return to a plastic state upon their reactivation, leaving them vulnerable to interference effects and requiring re-storage processes or else these memories might be permanently lost. The present study used a meta-analytic approach to critically evaluate the evidence for reactivation-induced changes in human episodic memory. Results indicated that reactivation makes episodic memories susceptible to physiological and behavioral interference. When applied shortly after reactivation, interference manipulations altered the amount of information that could be retrieved from the original learning event. This effect was more pronounced for remote memories and memories of narrative structure. Additionally, new learning following reactivation reliably increased the number of intrusions from new information into the original memory. These findings support a dynamic view of long-term memory by showing that memories can be changed long after they were acquired. Copyright © 2016 Elsevier Inc. All rights reserved.

Serum C-reactive protein levels in pre-dialysis chronic kidney ...

African Journals Online (AJOL)

2016-03-01

Mar 1, 2016 ... 1Department of Internal Medicine, Kidney Care Centre, Ondo, Ondo State, Nigeria. ... C-reactive protein (CRP) is a marker of cardiovascular disease and predictor of mortality in CKD patients. ... Methods: This was a case-control study involving 80 consecutive CKD patients and 40 control subjects without.

Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects

DEFF Research Database (Denmark)

James, W Philip T; Caterson, Ian D; Coutinho, Walmir

2010-01-01

The long-term effects of sibutramine treatment on the rates of cardiovascular events and cardiovascular death among subjects at high cardiovascular risk have not been established.......The long-term effects of sibutramine treatment on the rates of cardiovascular events and cardiovascular death among subjects at high cardiovascular risk have not been established....

Effect of alpha irradiation on UO{sub 2} surface reactivity in aqueous media

Energy Technology Data Exchange (ETDEWEB)

Jegou, C.; Muzeau, B.; Broudic, V.; Poulesquen, A.; Roudil, D. [Commissariat a l' Energie Atomique (CEA), Rhone Valley Research Center, DIEC/SESC/LMPA, Bagnols-sur-Ceze (France); Jorion, F. [Commissariat a l' Energie Atomique (CEA), Rhone Valley Research Center, DRCP/SE2A/LEMA, Bagnols-sur-Ceze (France); Corbel, C. [Commissariat a l' Energie Atomique (CEA), Saclay Research Center, DSM/DRECAM/SCM, Gif sur Yvette (France)

2005-07-01

The option of direct disposal of spent nuclear fuel in a deep geological formation raises the need to investigate the long-term behavior of the UO{sub 2} matrix in aqueous media subjected to {alpha}-{beta}-{gamma} radiation. The {beta}-{gamma} emitters account for most of the activity of spent fuel at the moment it is removed from the reactor, but diminish within a millennial time frame by over three orders of magnitude to less than the long-term activity. The latter persists over much longer time periods and must therefore be taken into account over a geological disposal time scale. Leaching experiments with solution renewal were carried out on UO{sub 2} pellets doped with alpha emitters ({sup 238}Pu and {sup 239}Pu) to quantify the impact of alpha irradiation on UO{sub 2} matrix alteration. Three batches of doped UO{sub 2} pellets with different alpha flux levels (3.30 x 10{sup 4}, 3.30 x 10{sup 5}, and 3.2 x 10{sup 6} {alpha} cm{sup -2} s{sup -1}) were studied. The results obtained in aerated and deaerated media immediately after sample annealing or interim storage in air provide a better understanding of the UO{sub 2} matrix alteration mechanisms under alpha irradiation. Interim storage in air of UO{sub 2} pellets doped with alpha emitters results in variations of the UO{sub 2} surface reactivity, which depends on the alpha particle flux at the interface and on the interim storage duration. The variation in the surface reactivity and the greater uranium release following interim storage cannot be attributed to the effect of alpha radiolysis in aerated media since the uranium release tends toward the same value after several leaching cycles for the doped UO{sub 2} pellet batches and spent fuel. Oxygen diffusion enhanced by alpha irradiation of the extreme surface layer and/or radiolysis of the air could account for the oxidation of the surface UO{sub 2} to UO{sub 2+x}. However, leaching experiments performed in deaerated media after annealing the samples and

PARTIAL REINFORCEMENT (ACQUISITION) EFFECTS WITHIN SUBJECTS.

Science.gov (United States)

AMSEL, A; MACKINNON, J R; RASHOTTE, M E; SURRIDGE, C T

1964-03-01

Acquisition performance of 22 rats in a straight alley runway was examined. The animals were subjected to partial reinforcement when the alley was black (B+/-) and continuous reinforcement when it was white (W+). The results indicated (a) higher terminal performance, for partial as against continuous reinforcement conditions, for starting-time and running-time measures, and (b) lower terminal performance under partial conditions for a goal-entry-time measure. These results confirm within subjects an effect previously demonstrated, in the runway, only in between-groups tests, where one group is run under partial reinforcement and a separate group is run under continuous reinforcement in the presence of the same external stimuli. Differences between the runway situation, employing a discrete-trial procedure and performance measures at three points in the response chain, and the Skinner box situation, used in its free-operant mode with a single performance measure, are discussed in relation to the present findings.

The Synergistic Effect of Proteins and Reactive Oxygen Species on Electrochemical Behaviour of 316L Stainless Steel for Biomedical Applications

Science.gov (United States)

Simionescu, N.; Benea, L.; Dumitrascu, V. M.

2018-06-01

The stainless steels, especially 316L type is the most used metallic biomaterials for biomedical applications due to their good biocompatibility, low price, excellent corrosion resistance, availability, easy processing and high strength. Due to these favorable properties 316L stainless steel has become the most attractive biomaterial for dental implants, stents and orthopedic implants. However an implant material in the human body is exposed to an action effect of other molecules, including proteins (such as albumin) and reactive oxygen species (such as hydrogen peroxide - H2O2 ) produced by bacteria and immune cells. In the literature there are few studies to follow the effect of proteins and reactive oxygen species on 316L stainless steel used as implant material and are still unclear. The degree of corrosion resistance is the first criterion in the use of a metallic biomaterial in the oral or body environment. The aim of this research work is to investigate the influence of proteins (albumin) and reactive oxygen species (H2O2 ) in combination, taking into account the synergistic effect of these two factors on 316L stainless steel. Albumin is present in the body near implants and reactive oxygen species could appear in inflammatory processes as well. The study shows that the presence of albumin and reactive species influences the corrosion resistance of 316L stainless steel in biological solutions. In this research work the corrosion behavior of 316L stainless steel is analyzed by electrochemical methods such as: open circuit potential (OCP), Electrochemical Impedance Spectroscopy (EIS). It was found that, the electrochemical results are in a good agreement with micro photographs taken before and after corrosion assays. The albumin and reactive oxygen species have influence on 316L stainless steel behavior.

How does tunneling contribute to counterintuitive H-abstraction reactivity of nonheme Fe(IV)O oxidants with alkanes?

Science.gov (United States)

Mandal, Debasish; Ramanan, Rajeev; Usharani, Dandamudi; Janardanan, Deepa; Wang, Binju; Shaik, Sason

2015-01-21

This article addresses the intriguing hydrogen-abstraction (H-abstraction) and oxygen-transfer (O-transfer) reactivity of a series of nonheme [Fe(IV)(O)(TMC)(Lax)](z+) complexes, with a tetramethyl cyclam ligand and a variable axial ligand (Lax), toward three substrates: 1,4-cyclohexadiene, 9,10-dihydroanthracene, and triphenyl phosphine. Experimentally, O-transfer-reactivity follows the relative electrophilicity of the complexes, whereas the corresponding H-abstraction-reactivity generally increases as the axial ligand becomes a better electron donor, hence exhibiting an antielectrophilic trend. Our theoretical results show that the antielectrophilic trend in H-abstraction is affected by tunneling contributions. Room-temperature tunneling increases with increase of the electron donation power of the axial-ligand, and this reverses the natural electrophilic trend, as revealed through calculations without tunneling, and leads to the observed antielectrophilic trend. By contrast, O-transfer-reactivity, not being subject to tunneling, retains an electrophilic-dependent reactivity trend, as revealed experimentally and computationally. Tunneling-corrected kinetic-isotope effect (KIE) calculations matched the experimental KIE values only if all of the H-abstraction reactions proceeded on the quintet state (S = 2) surface. As such, the present results corroborate the initially predicted two-state reactivity (TSR) scenario for these reactions. The increase of tunneling with the electron-releasing power of the axial ligand, and the reversal of the "natural" reactivity pattern, support the "tunneling control" hypothesis (Schreiner et al., ref 19). Should these predictions be corroborated, the entire field of C-H bond activation in bioinorganic chemistry would lay open to reinvestigation.

Thromboxane production in morbidly obese subjects.

Science.gov (United States)

Graziani, Francesca; Biasucci, Luigi M; Cialdella, Pio; Liuzzo, Giovanna; Giubilato, Simona; Della Bona, Roberta; Pulcinelli, Fabio M; Iaconelli, Amerigo; Mingrone, Geltrude; Crea, Filippo

2011-06-01

Postmortem studies have demonstrated that morbidly obese subjects, surprisingly, have less coronary atherosclerosis than obese subjects. However, the reasons for this apparent protection from atherosclerosis are not yet clear. Thromboxane A2, a marker of platelet activation, is greater in obese subjects than in lean subjects, and this might be a clue to their increased cardiovascular risk. However, data on thromboxane A2 in morbidly obese subjects are lacking; therefore, we hypothesized that lower levels of thromboxane A2 in morbidly obese subjects might play a role in their lower atherothrombotic burden. We measured the serum levels of thromboxane B2 (TxB2), a stable metabolite of thromboxane A2, high-sensitivity C-reactive protein (hs-CRP) and leptin in 17 lean subjects (body mass index [BMI] 22.9 ± 1.6 kg/m(2)), 25 obese subjects (BMI 32.6 ± 2.4 kg/m(2)), and 23 morbidly obese subjects (BMI 48.6 ± 7.1 kg/m(2)), without insulin resistance, diabetes, or overt cardiovascular disease. The serum TxB2 levels were lower in the lean subjects than in the obese subjects (p = 0.046) and in the morbidly obese subjects than in the lean and obese subjects (p = 0.015 and p lean subjects (hs-CRP, p lean subjects (p lean subjects, suggesting that reduced platelet activation could play a role in the paradoxical protection of morbidly obese subjects from atherosclerosis, despite the greater levels of leptin. Copyright © 2011 Elsevier Inc. All rights reserved.

Reactivity of Dual-Use Decontaminants with Chemical Warfare Agents

Science.gov (United States)

2016-07-01

REACTIVITY OF DUAL-USE DECONTAMINANTS WITH CHEMICAL WARFARE AGENTS ECBC-TR-1384... Decontaminants with Chemical Warfare Agents 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Willis, Matthew P...extraction) of chemical warfare agents from materials. 15. SUBJECT TERMS GD HD Decontamination Hazard mitigation VX Chemical warfare agent Liquid-phase

Effects of interpretation training on hostile attribution bias and reactivity to interpersonal insult.

Science.gov (United States)

Hawkins, Kirsten A; Cougle, Jesse R

2013-09-01

Research suggests that individuals high in anger have a bias for attributing hostile intentions to ambiguous situations. The current study tested whether this interpretation bias can be altered to influence anger reactivity to an interpersonal insult using a single-session cognitive bias modification program. One hundred thirty-five undergraduate students were randomized to receive positive training, negative training, or a control condition. Anger reactivity to insult was then assessed. Positive training led to significantly greater increases in positive interpretation bias relative to the negative group, though these increases were only marginally greater than the control group. Negative training led to increased negative interpretation bias relative to other groups. During the insult, participants in the positive condition reported less anger than those in the control condition. Observers rated participants in the positive condition as less irritated than those in the negative condition and more amused than the other two conditions. Though mediation of effects via bias modification was not demonstrated, among the positive condition posttraining interpretation bias was correlated with self-reported anger, suggesting that positive training reduced anger reactivity by influencing interpretation biases. Findings suggest that positive interpretation training may be a promising treatment for reducing anger. However, the current study was conducted with a non-treatment-seeking student sample; further research with a treatment-seeking sample with problematic anger is necessary. Copyright © 2013. Published by Elsevier Ltd.

Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects

Energy Technology Data Exchange (ETDEWEB)

Lu, X., E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Naidis, G.V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Laroussi, M. [Plasma Engineering & Medicine Institute, Old Dominion University, Norfolk, VA 23529 (United States); Reuter, S. [Leibniz Institute for Plasma Science and Technology, Felix-Hausdorff-Strasse 2, 17489 Greifswald (Germany); Graves, D.B. [Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720 (United States); Ostrikov, K. [Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000 (Australia); School of Physics, Chemistry, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000 (Australia); Commonwealth Scientific and Industrial Research Organization, P.O.Box 218, Lindfield, NSW 2070 (Australia); School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia)

2016-05-04

Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmospheric-pressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, time-resolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors’ vision for the emerging convergence trends across several disciplines and application domains is presented to

Effects of methyl group on aromatic hydrocarbons on the nanostructures and oxidative reactivity of combustion-generated soot

KAUST Repository

Guerrero Peñ a, Gerardo D.J.; Alrefaai, Mhd Maher; Yang, Seung Yeon; Raj, Abhijeet; Brito, Joaquin L.; Stephen, Samuel; Anjana, Tharalekshmy; Pillai, Vinu; Al Shoaibi, Ahmed; Chung, Suk-Ho

2016-01-01

The substituted and unsubstituted aromatic hydrocarbons, present in transportation fuels such as gasoline and diesel, are thought to be responsible for most of the soot particles produced during their combustion. However, the effects of the substituted alkyl groups on the aromatic hydrocarbons on their sooting tendencies, and on the physical and chemical properties of soot produced from them are not well understood. In this work, the effect of the presence of methyl groups on aromatic hydrocarbons on their sooting propensity, and on the oxidative reactivity, morphology, and chemical composition of soot generated from them in diffusion flames is studied using benzene, toluene, and m-xylene as fuels. Several experimental techniques including high resolution transmission electron microscopy and X-ray diffraction are used to identify the morphological changes in soot, whereas the elemental and thermo-gravimetric analyses, electron energy loss spectroscopy, and Fourier transform infrared spectroscopy are used to study the changes in its chemical properties and reactivity. The activation energies for soot oxidation are calculated at different conversion levels, and a trend in the reactivity of soots from benzene, toluene and m-xylene is reported. It is observed that the sizes of primary particles and graphene-like sheets, and the concentrations of aliphatics and oxygenated groups in soot particles decreased with the addition of methyl group(s) on the aromatic ring. The physicochemical changes in soot are found to support the oxidative reactivity trends. © 2016 The Combustion Institute

Effects of methyl group on aromatic hydrocarbons on the nanostructures and oxidative reactivity of combustion-generated soot

KAUST Repository

Guerrero Peña, Gerardo D.J.

2016-07-23

The substituted and unsubstituted aromatic hydrocarbons, present in transportation fuels such as gasoline and diesel, are thought to be responsible for most of the soot particles produced during their combustion. However, the effects of the substituted alkyl groups on the aromatic hydrocarbons on their sooting tendencies, and on the physical and chemical properties of soot produced from them are not well understood. In this work, the effect of the presence of methyl groups on aromatic hydrocarbons on their sooting propensity, and on the oxidative reactivity, morphology, and chemical composition of soot generated from them in diffusion flames is studied using benzene, toluene, and m-xylene as fuels. Several experimental techniques including high resolution transmission electron microscopy and X-ray diffraction are used to identify the morphological changes in soot, whereas the elemental and thermo-gravimetric analyses, electron energy loss spectroscopy, and Fourier transform infrared spectroscopy are used to study the changes in its chemical properties and reactivity. The activation energies for soot oxidation are calculated at different conversion levels, and a trend in the reactivity of soots from benzene, toluene and m-xylene is reported. It is observed that the sizes of primary particles and graphene-like sheets, and the concentrations of aliphatics and oxygenated groups in soot particles decreased with the addition of methyl group(s) on the aromatic ring. The physicochemical changes in soot are found to support the oxidative reactivity trends. © 2016 The Combustion Institute

Inhibitory Effects of Trapping Agents of Sulfur Drug Reactive Intermediates against Major Human Cytochrome P450 Isoforms

Directory of Open Access Journals (Sweden)

Jasleen K. Sodhi

2017-07-01

Full Text Available In some cases, the formation of reactive species from the metabolism of xenobiotics has been linked to toxicity and therefore it is imperative to detect potential bioactivation for candidate drugs during drug discovery. Reactive species can covalently bind to trapping agents in in vitro incubations of compound with human liver microsomes (HLM fortified with β-nicotinamide adenine dinucleotide phosphate (NADPH, resulting in a stable conjugate of trapping agent and reactive species, thereby facilitating analytical detection and providing evidence of short-lived reactive metabolites. Since reactive metabolites are typically generated by cytochrome P450 (CYP oxidation, it is important to ensure high concentrations of trapping agents are not inhibiting the activities of CYP isoforms. Here we assessed the inhibitory properties of fourteen trapping agents against the major human CYP isoforms (CYP1A2, 2C9, 2C19, 2D6 and 3A. Based on our findings, eleven trapping agents displayed inhibition, three of which had IC50 values less than 1 mM (2-mercaptoethanol, N-methylmaleimide and N-ethylmaleimide (NEM. Three trapping agents (dimedone, N-acetyl-lysine and arsenite did not inhibit CYP isoforms at concentrations tested. To illustrate effects of CYP inhibition by trapping agents on reactive intermediate trapping, an example drug (ticlopidine and trapping agent (NEM were chosen for further studies. For the same amount of ticlopidine (1 μM, increasing concentrations of the trapping agent NEM (0.007–40 mM resulted in a bell-shaped response curve of NEM-trapped ticlopidine S-oxide (TSO-NEM, due to CYP inhibition by NEM. Thus, trapping studies should be designed to include several concentrations of trapping agent to ensure optimal trapping of reactive metabolites.

Effect of viscosity, basicity and organic content of composite flocculant on the decolorization performance and mechanism for reactive dyeing wastewater

Institute of Scientific and Technical Information of China (English)

Yuanfang Wang; Baoyu Gao; Qinyan Yue; Yah Wang

2011-01-01

A coagulation/flocculation process using the composite floceulant polyaluminum chloride-epichlorohydrin dimethylamine (PAC-EPI-DMA) was employed for the treatment of an anionic azo dye (Reactive Brilliant Red K-2BP dye).The effect of viscosity (η),basicity (B =[OH]/[Al]) and organic content (Wp) on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated.The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA.PAC-EPI-DMA with an intermediate η (2400 mPa-sec) gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers.The Wp of the composite flocculant was a minor important factor for the flocculation.The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp,whereasthe charge neutralization of them was weaker with the increase of Wp.There was interaction between Wp and B on the removal of reactive dye.The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater,which could achieve high reactive dye removal efficiency with low organic dosage.

Reactive nitrogen in the environment and its effect on climate change

International Nuclear Information System (INIS)

Erisman, J.W.; Bleeker, A.; Galloway, J.; Seitzinger, S.; Butterbach-Bahl, K.

2011-01-01

Humans have doubled levels of reactive nitrogen in circulation, largely as a result of fertilizer application and fossil fuel burning. This massive alteration of the nitrogen cycle affects climate, food security, energy security, human health and ecosystem services. Our estimates show that nitrogen currently leads to a net-cooling effect on climate with very high uncertainty. The many complex warming and cooling interactions between nitrogen and climate need to be better assessed, taking also into account the other effects of nitrogen on human health, environment and ecosystem services. Through improved nitrogen management substantial reductions in atmospheric greenhouse gas concentrations could be generated, also allowing for other co-benefits, including improving human health and improved provision of ecosystem services, for example clean air and water, and biodiversity.

GRANULAR ACTIVATED CARBON ADSORPTION AND INFRARED REACTIVATION: A CASE STUDY

Science.gov (United States)

A study evaluated the effectiveness and cost of removing trace organic contaminants and surrogates from drinking water by granular activated carbon (GAC) adsorption. The effect of multiple reactivations of spent GAC was also evaluated. Results indicated that reactivated GAC eff...

Association Between Stress-Related Sleep Reactivity and Metacognitive Beliefs About Sleep in Insomnia Disorder: Preliminary Results.

Science.gov (United States)

Palagini, Laura; Bruno, Rosa Maria; Paolo, Toti; Caccavale, Lisa; Gronchi, Alessia; Mauri, Mauro; Riemann, Dieter; Drake, Christopher L

2016-01-01

To evaluate the relation between stress-related sleep reactivity and metacognitive beliefs about sleep in subjects with insomnia disorder (93) and in a group of healthy controls (30) a set of variables, including Ford Insomnia Response to Stress Test (FIRST) and Metacognition Questionnaire-Insomnia (MCQ-I), have been used. Internal consistency of the Italian version of FIRST was studied. Univariate correlation, regression analysis, and principal component analysis were also performed. The Italian version of FIRST showed good internal consistency and discriminant validity. Sleep reactivity was higher in women (p sleep (p sleep reactivity. Therapeutic strategies acting selectively on metacognition to reduce stress-related sleep reactivity in insomnia may be useful.

Effect of nifedipine on gastric emptying in normal subjects

Energy Technology Data Exchange (ETDEWEB)

Traube, M.; Lange, R.C.; McAllister, R.G.; McCallum, R.W.

1985-05-01

Nifedipine (N) inhibits calcium entry into smooth muscle cells and relaxes esophageal smooth muscle. The authors studied N's effect on gastric emptying of liquids and solids. Ten normal subjects underwent radionuclide (In-111-DTPA in water and Tc-99m-sulfur colloid tagged to chicken liver) emptying tests with and without 30 mg N given orally 20 min prior to meal ingestion. Peak plasma N levels were either 30 or 60 min after drug dosing and showed a 3-fold variation (low 145 ng/ml, high 434 ng/ml). Both mean N levels and integral concentration time values were twice as high as those obtained after 30 mg sublingual dosing in normals previously studied in our lab. The authors conclude that plasma N levels which are associated with significant esophageal motility effects do not change gastric emptying in normal subjects. The data also show that N levels are greater after oral than sublingual dosing of 30 mg in normal subjects.

Effect of nifedipine on gastric emptying in normal subjects

International Nuclear Information System (INIS)

Traube, M.; Lange, R.C.; McAllister, R.G.; McCallum, R.W.

1985-01-01

Nifedipine (N) inhibits calcium entry into smooth muscle cells and relaxes esophageal smooth muscle. The authors studied N's effect on gastric emptying of liquids and solids. Ten normal subjects underwent radionuclide (In-111-DTPA in water and Tc-99m-sulfur colloid tagged to chicken liver) emptying tests with and without 30 mg N given orally 20 min prior to meal ingestion. Peak plasma N levels were either 30 or 60 min after drug dosing and showed a 3-fold variation (low 145 ng/ml, high 434 ng/ml). Both mean N levels and integral concentration time values were twice as high as those obtained after 30 mg sublingual dosing in normals previously studied in our lab. The authors conclude that plasma N levels which are associated with significant esophageal motility effects do not change gastric emptying in normal subjects. The data also show that N levels are greater after oral than sublingual dosing of 30 mg in normal subjects

A method for on-line reactivity monitoring in nuclear reactors

International Nuclear Information System (INIS)

Dulla, S.; Nervo, M.; Ravetto, P.

2014-01-01

Highlights: • The problem of the on-line monitoring of reactivity in a source-free nuclear reactor is considered. • A relationship between the system stable period and the power, its derivative and its integral is derived. • The reactivity can be reconstructed at each time instant from the measured power-related quantities. • A study on the sensitivity of the reactivity to the uncertainty on the values of the integral parameters is performed. • The spatial effects are investigated by applying the method to the interpretation of flux signals. - Abstract: In the present work the problem of the on-line monitoring of the reactivity in a source-free nuclear reactor is considered. The method is based on the classic point kinetic model of reactor physics. A relationship between the instantaneous value of the system stable period and the values of the neutron flux amplitude (or the power), of its derivative and of the integral convolution term determining the instantaneous value of the effective delayed neutron concentration is derived. The reactivity can then be evaluated through the application of the inhour equation, assuming the effective delayed neutron fraction and prompt generation time are known from independent measurements. Since the power related quantities can be assumed to be experimental observables at each instant, the reactivity can be easily reconstructed. The method is tested at first through the interpretation of power histories simulated by the solution of the point kinetic equations; the effect of the time interval between power detections on the accuracy is studied, proving the excellent performance of the procedure. The work includes also a study on the sensitivity of the reactivity forecast to the uncertainty on the values of the effective delayed neutron fraction and prompt generation time. The spatial effects are investigated by applying the method to the interpretation of flux evolution histories generated by a numerical code solving

Determination of reactivity coefficients from measurable effects of small external perturbations using a bank of Kalman filters

International Nuclear Information System (INIS)

Racz, A.

1990-12-01

The goal of this paper is to present a method for the determination of reactivity coefficients in a nuclear power reactor in operation. A method based on Kalman filtering technique and the Magill-Bogler test is proposed for the determination of reactivity coefficients from measured effects of small external perturbation introduced into a steady-state power reactor. Numerical experiments are presented to justify the procedure. A realistic problem is considered: the calculation of the control rod worth. Finally a possible way is given to check the goodness of the estimation. (author) 16 refs.; 4 figs

Various reactivity effects value for assuring fast reactor core inherent safety

International Nuclear Information System (INIS)

Belov, S.B.; Vasilyev, B.A.

1991-01-01

The paper presents the results of temperature and power reactivity feedback components calculations for fast reactors with different core volume when using oxide, carbide, nitride and metal fuel. Reactor parameters change in loss of flow without scram and transient over power without scram accidents was evaluated. The importance of various reactivity feedback components in restricting the consequences of these accidents has been analyzed. (author)

Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation*

Science.gov (United States)

Gopinath, Vipin; Raghunandanan, Sajith; Gomez, Roshna Lawrence; Jose, Leny; Surendran, Arun; Ramachandran, Ranjit; Pushparajan, Akhil Raj; Mundayoor, Sathish; Jaleel, Abdul; Kumar, Ramakrishnan Ajay

2015-01-01

Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) have rarely been subjected to a detailed investigation. In this study, we developed an in vitro reactivation system by re-aerating the virulent laboratory strain of M. tuberculosis that was made dormant employing Wayne's dormancy model, and compared the proteome profiles of dormant and reactivated bacteria using label-free one-dimensional LC/MS/MS analysis. The proteome of dormant bacteria was analyzed at nonreplicating persistent stage 1 (NRP1) and stage 2 (NRP2), whereas that of reactivated bacteria was analyzed at 6 and 24 h post re-aeration. Proteome of normoxially grown bacteria served as the reference. In total, 1871 proteins comprising 47% of the M. tuberculosis proteome were identified, and many of them were observed to be expressed differentially or uniquely during dormancy and reactivation. The number of proteins detected at different stages of dormancy (764 at NRP1, 691 at NRP2) and reactivation (768 at R6 and 983 at R24) was very low compared with that of the control (1663). The number of unique proteins identified during normoxia, NRP1, NRP2, R6, and R24 were 597, 66, 56, 73, and 94, respectively. We analyzed various biological functions during these conditions. Fluctuation in the relative quantities of proteins involved in energy metabolism during dormancy and reactivation was the most significant observation we made in this study. Proteins that are up-regulated or uniquely expressed during reactivation from dormancy offer to be attractive targets for therapeutic

The effect of periodontal treatment on serum leptin, interleukin-6, and C-reactive protein.

Science.gov (United States)

Shimada, Yasuko; Komatsu, Yasutaka; Ikezawa-Suzuki, Ikuyo; Tai, Hideaki; Sugita, Noriko; Yoshie, Hiromasa

2010-08-01

Previous studies suggest that periodontitis is closely related to obesity and metabolic syndrome. Leptin, a pleiotrophic hormone produced by adipose tissue, has been reported to be related to periodontitis. This study investigates the effects of periodontal treatment on the serum levels of leptin and other cytokines in patients with chronic periodontitis (CP). Serum samples were taken from 33 CP patients (22 non-smokers, 11 smokers) and 18 healthy subjects. The serum leptin, adiponectin, tumor necrosis factor-alpha, interleukin (IL)-6, and C-reactive protein (CRP) levels were measured before and after non-surgical periodontal treatment. Significant differences between healthy and CP patients were found in serum leptin, IL-6, and CRP levels (P = 0.0018, P = 0.0064, and P = 0.0095, respectively). The serum leptin level was associated with mean probing depth, mean clinical attachment level, mean alveolar bone loss, and body mass index. There were significant associations between serum leptin levels and IL-6 and CRP levels. After non-surgical periodontal treatment, serum leptin, IL-6, and CRP levels were significantly decreased (mean +/- SD before and after, P value, respectively: leptin, 8.02 +/- 5.5, 7.10 +/- 4.4, P = 0.015; IL-6, 1.73 +/- 1.02, 1.36 +/- 0.73, P = 0.048; and CRP, 802.0 +/- 1065, 491.2 +/- 479.3, P = 0.047). Periodontal treatment is effective in reducing serum leptin, IL-6, and CRP levels. The results suggest that leptin, IL-6, and CRP could be mediating factors that connect metabolic syndrome and periodontitis.

A DRAGON-MCNP comparison of void reactivity calculations

Energy Technology Data Exchange (ETDEWEB)

Marleau, G [Ecole Polytechnique, Montreal, PQ (Canada). Inst. de Genie Nucleaire; Milgram, M S [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1996-12-31

The determination of the reactivity coefficients associated with coolant voiding in a CANDU reactor is a subject which has attracted a large amount of interest in the last few years both from the theoretical and experimental point of view. One expects that deterministic codes such as DRAGON and WIMS-AECL or the MCNP4 Monte Carlo code should be able to adequately simulate the cell behaviour upon coolant voiding. However, the absence of an experimental database at equilibrium and discharge burnups has not permitted the full validation of any of these lattice codes, although a partial validation through comparison of two different computer codes has been considered. Here we present a comparison between DRAGON and MCNP4 of the void reactivity evaluation for fresh fuel. (author). 16 refs., 5 tabs.

A DRAGON-MCNP comparison of void reactivity calculations

International Nuclear Information System (INIS)

Marleau, G.

1995-01-01

The determination of the reactivity coefficients associated with coolant voiding in a CANDU reactor is a subject which has attracted a large amount of interest in the last few years both from the theoretical and experimental point of view. One expects that deterministic codes such as DRAGON and WIMS-AECL or the MCNP4 Monte Carlo code should be able to adequately simulate the cell behaviour upon coolant voiding. However, the absence of an experimental database at equilibrium and discharge burnups has not permitted the full validation of any of these lattice codes, although a partial validation through comparison of two different computer codes has been considered. Here we present a comparison between DRAGON and MCNP4 of the void reactivity evaluation for fresh fuel. (author). 16 refs., 5 tabs

Appetitive motivation and negative emotion reactivity among remitted depressed youth.

Science.gov (United States)

Hankin, Benjamin L; Wetter, Emily K; Flory, Kate

2012-01-01

Depression has been characterized as involving altered appetitive motivation and emotional reactivity. Yet no study has examined objective indices of emotional reactivity when the appetitive/approach system is suppressed in response to failure to attain a self-relevant goal and desired reward. Three groups of youth (N = 98, ages 9-15; remitted depressed, n = 34; externalizing disordered without depression, n = 30; and healthy controls, n = 34) participated in a novel reward striving task designed to activate the appetitive/approach motivation system. Objective facial expressions of emotion were videotaped and coded throughout both failure (i.e., nonreward) and control (success and reward) conditions. Observational coding of facial expressions as well as youths' subjective emotion reports showed that the remitted depressed youth specifically exhibited more negative emotional reactivity to failure in the reward striving task, but not the control condition. Neither externalizing disordered (i.e., attention deficit hyperactivity disorder, conduct disorder, and/or oppositional defiant disorder) nor control youth displayed greater negative emotional reactivity in either the failure or control condition. Findings suggest that depression among youth is related to dysregulated appetitive motivation and associated negative emotional reactivity after failing to achieve an important, self-relevant goal and not attaining reward. These deficits in reward processing appear to be specific to depression as externalizing disordered youth did not display negative emotional reactivity to failure after their appetitive motivation system was activated.

Effects of Experimenter Surveillance on Reactive Self-Monitoring.

Science.gov (United States)

Belfiore, Phillip J.; And Others

1989-01-01

Worker reactivity patterns were examined in a study of two women with mild and moderate mental retardation who self-monitored their work productivity with and without external surveillance. Findings suggest that surveillance is a setting event that may be important in achieving and maintaining self-management program benefits. (MSE)

Effects of a visuotemporal cue on walking ability of independent ambulatory subjects with spinal cord injury as compared with healthy subjects.

Science.gov (United States)

Pramodhyakul, N; Amatachaya, P; Sooknuan, T; Arayawichanon, P; Amatachaya, S

2014-03-01

An experimental, cross-sectional study. To investigate effects of using a visuotemporal cue on the walking ability of independent ambulatory subjects with spinal cord injury (SCI) as compared with healthy subjects. A tertiary rehabilitation center, Thailand. Forty independent ambulatory subjects with SCI and healthy subjects participated in the study (20 subjects per group). All of them were assessed for their walking speed, stride length, cadence and percents of step symmetry under two conditions, including walking at their fastest speed with and without a visuotemporal cue along a 10 m walkway. When walking with a visuotemporal cue, walking speed, stride length and cadence of the subjects were significantly increased from the uncued condition (Pwalking speed and cadence, whereas, subjects with SCI demonstrated significantly higher improvement in stride length as compared with the other group (Pbenefits of using a visuotemporal cue to improve variables relating to walking ability in subjects with intact integrative capability of the brain but with different levels of sensorimotor deterioration. The findings suggest the use of a visuotemporal cue to improve the effectiveness of programs in sport and exercise sciences, and rehabilitation treatments.

Effects of some structural materials on the reactivity and flux distributions in a pressurised water reactor

International Nuclear Information System (INIS)

Mondal, A.M.W.; Mannan, M.A.

1983-01-01

The effect of the structural materials of the guide tubes, spacer grids and the shroud on the reactivity and the flux distribution of a Pressurised Water Reactor (PWR) has been studied. Group constants of different cells of guide tubes, spacer grids, shroud and the fuel have been calculated using the cell codes LEOPARD, PANTHER and METHUSELAH. Core calculations have been performed using the diffusion code EQUIPOISE. It has been found for a PWR of 1300 MWe of Kraftwork Union design for Iron that the total change in reactivity due to the presence of guide tubes, spacer grids and the shroud is about -2.48x10 -2 . (author)

Studies of the reactivity effects of hydrogenous material in a sodium cooled fast reactor

International Nuclear Information System (INIS)

Ingram, D.; Sweet, D.W.

1979-01-01

The reactivity effects of hydrogenous substances, such as the oil used in the primary coolant pumps, which could enter the core of a fast reactor in a hypothetical accident, have been studied in a series of experiments and calculations. Measurements to study the influence of the density of the hydrogen and its location on reactivity were made in two assemblies in the zero power reactor ZEBRA. The first of these was similar in size to PFR and the second was the large BZB assembly of the BIZET programme. The results of this work have been compared with calculations using the FGL5 nuclear data library. Calculations for a 1200 MW (e) CFR have been made using three quantities of material (8, 40 and 160 Kg of hydrocarbon, equivalent to 10, 50 and 200 litres of oil). The calculations have used different geometrical models and hydrocarbon distributions and have explored the influence of core temperature, fuel burn-up and the presence of control rods to estimate the maximum reactivity changes that can be obtained. The results have been analysed in terms of components of the change in neutron balance produced by the material and uncertainties in these have been derived from the ZEBRA work. (author)

C-reactive Protein and Disease Outcome in Nigerian Sickle Cell ...

African Journals Online (AJOL)

Background: Evidence suggests that sickle cell disease (SCD) is associated with a chronic inflammatory state. C.reactive protein (CRP) is known to modulate inflammation. Its role in the chronic inflammation of SCD may make it valuable as a therapeutic target. Aim: The aim was to determine CRP levels in SCD subjects in ...

Human serum protein and C-reactive protein levels among HIV ...

African Journals Online (AJOL)

Human serum protein and C-reactive protein levels were determined among HIV patients visiting St Camillus Hospital, Uromi, Edo State, Nigeria, between January to March, 2013. Fifty (50) HIV patients (20 males; 30 females) and 50 control subjects (24 males; 26 females) were enrolled for this study. The clinical status of ...

Effect of 137Cs on immunological reactivity

International Nuclear Information System (INIS)

Shubik, V.M.

1975-01-01

An important role of 137 Cs as a new ecological factor was shown by analyzing 31 different studies. The radioisotope may at present be detected in the organisms of all inhabitants of this planet. The migration of 137 Cs along the chain lichen-deer-man leads to its accumulation in the organism of humans living in the Extreme North and taking venison in their food. Although the high sensitivity of immunological reactions to various unfavourable environmental factors is well known, data on the effect of incorporated 137 Cs on immunity are scanty. Experiments on animals showed changes in factors of nonspecific immunity (phagocytic reaction of blood neutrophils, bactericidal activity, lysozyme and complement titres of blood serum) and specific immunity (formation of antiviral antibodies). The blood of animals injured by the isotope displays complete and incomplete autoantibodies. The dependence of immunobiological changes on the dose absorbed by the organism is shown. The 137 Cs intake of inhabitants of the Extreme North who eat venison did not, with the absorbed dose equalling up to 50 Mrem per year, lead to changes in their immunological reactivity. (author)

Measurement of large asymptotic reactor periods from about 103 to 4.104 sec) to determine reactivity effects of small samples

International Nuclear Information System (INIS)

Grinevich, F.A.; Evchuk, A.I.; Klimentov, V.B.; Tyzh, A.V.; Churkin, Yu.I.; Yaroshevich, O.I.

1977-01-01

All investigation programs on fast reactor physics include measurements of low reactivity values (1-0.01)x10 -5 ΔK/K. An application of the pile oscillator technique for the purpose requires a special critical assembly for an installation of the oscillator. Thus it is of interest to develop relatively simple methods. In particular, one of such methods is the asymptotic period method which is widely used for low reactivity measurements. The description of the method and equipment developed for low reactivity measurements according to the measurements of the steady-state reactor period is presented. The equipment has been tested on the BTS-2 fast-thermal critical assembly. Measurement results on the reactivity effects of small samples in the fast zone centre are given. It is shown that the application of the method of measuring long steady-state periods and developed and tested equipment enables the reactivity of (1+-0.02)x10 -5 ΔK/K to be determined at the critical assembly power of 5 to 10 Wt. The disadvantage of the method presented is the time lost on reaching the steady-state period which results in greater sensitivity of the method to reactivity drifts

Relations of children's proactive and reactive assertiveness to peer acceptance: moderating effects of social interest.

Science.gov (United States)

Lee, Han-Jong

2014-06-01

Previous studies on the social outcome of assertiveness reported mixed findings, failing to support the assumption that assertiveness promotes peer acceptance. In an attempt to provide explanations for the inconsistencies in prior findings, this study proposed making a distinction between proactive and reactive assertiveness and examined the moderating effects of social interest. A total of 441 fifth and sixth graders (232 boys, 209 girls; M age = 10.6 yr., SD = 0.6) participated in the study. Results indicated that proactive assertiveness was positively related to peer acceptance regardless of social interest. By contrast, reactive assertiveness was positively related to peer acceptance but only when social interest is high. When social interest is low, it was negatively associated with peer acceptance.

Measurements of low reactivities using a reactor oscillator

International Nuclear Information System (INIS)

Obradovic, D.; Petrovic, M.

1965-12-01

Most of the methods of measuring reactivity are limited to the region from several hundreds to several thousands of pcm. The present work develops a method of measuring low reactivities from several pcm to about 600 pcm using the ROB-1 reactor oscillator on the RB reactor of the Boris Kidric Institute of Nuclear Sciences at Vinca. The accuracy of measurement is better than 1%. Several methods are used to measure low reactivities. The most often used is the method based on measuring the stable reactor period. The bottom limit of this method is about 30 porn /1,2/. For control rod calibration the method of rod oscillation is used /3,4/. This method is confronted with considerable influence of space effects /5/. Reference /6/ reports on a method for measuring the reactivity coefficient at a critical level in liquid-moderated reactors. The method is based on measuring reactor response to the oscillation of the moderator about the critical level. The present work reports on a method of determining the reactivity by measuring the phase shift between the perturbation of the effective multiplication factor and reactor response. With the use of the ROB-1 reactor oscillator, the method allows measurement of the reactivity from several pcm to about 600 pcm with an accuracy of 1% (author)

Measurements of low reactivities using a reactor oscillator

Energy Technology Data Exchange (ETDEWEB)

Obradovic, D; Petrovic, M [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1965-12-15

Most of the methods of measuring reactivity are limited to the region from several hundreds to several thousands of pcm. The present work develops a method of measuring low reactivities from several pcm to about 600 pcm using the ROB-1 reactor oscillator on the RB reactor of the Boris Kidric Institute of Nuclear Sciences at Vinca. The accuracy of measurement is better than 1%. Several methods are used to measure low reactivities. The most often used is the method based on measuring the stable reactor period. The bottom limit of this method is about 30 porn /1,2/. For control rod calibration the method of rod oscillation is used /3,4/. This method is confronted with considerable influence of space effects /5/. Reference /6/ reports on a method for measuring the reactivity coefficient at a critical level in liquid-moderated reactors. The method is based on measuring reactor response to the oscillation of the moderator about the critical level. The present work reports on a method of determining the reactivity by measuring the phase shift between the perturbation of the effective multiplication factor and reactor response. With the use of the ROB-1 reactor oscillator, the method allows measurement of the reactivity from several pcm to about 600 pcm with an accuracy of 1% (author)

Effects of non-soy legume consumption on C-reactive protein: a systematic review and meta-analysis.

Science.gov (United States)

Salehi-Abargouei, Amin; Saraf-Bank, Sahar; Bellissimo, Nick; Azadbakht, Leila

2015-05-01

Because of conflicting results of presented studies, the aim of this systematic review and meta-analysis of randomized clinical trials (RCTs) was to examine the effect of non-soy legume intake on inflammatory markers and C-reactive protein (CRP). We searched Pubmed, ISI Web of Knowledge, SCOPUS, and Google Scholar for relevant studies up to July 2013, using medical subject headings [MeSH] and other related keywords. Nine RCTs were systematically reviewed to examine the effect of non-soy legume consumption on inflammatory markers. Eight studies involving 464 participants were included in the meta-analysis. The results of the meta-analysis showed that non-soy legume consumption had a trend toward a significant effect on decreasing CRP and high-sensitivity (hs)-CRP concentrations (mean difference (MD) = -0.21; 95% confidence interval [CI], -0.44 to 0.02; P = 0.068). There was no overall effect of non-soy legume consumption on CRP or hs-CRP levels in either the parallel or crossover study designs. Our subgroup analysis of CRP type and study design, showed that non-soy legume intake had a significant effect on CRP levels in parallel studies (MD = -1.01; 95% CI, -1.78 to -0.23; P = 0.011) and a significant effect on hs-CRP levels (MD = -0.53; 95% CI, -0.95 to -0.11; P = 0.014) and in the crossover sub group (MD = -0.68; 95% CI, -1.28 to -0.08; P = 0.026). This review of RCTs showed that non-soy legume consumption may contribute to reductions in CRP and hs-CRP concentrations. However, further controlled clinical trials are needed to investigate the effect of non-soy legume intake on other inflammatory markers. Copyright © 2015 Elsevier Inc. All rights reserved.

The effect of actinide thin films on the electronic structure and reactivity of various elements

Energy Technology Data Exchange (ETDEWEB)

Gouder, T.; Colmenares, C.

1994-12-08

This report summarizes the experimental work carried out at the Lawrence Livermore National Laboratory on the electronic structure and reactivity of uranium thin films on Pd, Pt, Si, graphite, Cu, and Au substrates from 1990 to 1993. The U-Pd system was studied in the most detail because it was the first to be chosen right after the completion of the experimental equipment. We first studied and characterized clean U overlayers and the possible surface reactions between this metal and the substrates studied. We then subjected these systems to reactive conditions such as heating and adsorbing corrosive gases (O{sub 2}, CO, CO{sub 2}, and C{sub 2}H{sub 4}). Finally we investigated the diffusion of U metal and some of its compounds into the substrates. A new technique was developed, based on Auger Electron Spectroscopy, to follow in real time the diffusion of U overlayers into the substrate. The temperature of the sample is ramped linearly up to 900{degrees}C while following the Auger peak intensities of the two components for a given system. Diffusion rates are obtained by differentiating the measured intensity curves, then peaks result corresponding to diffusion processes with different activation energies. This technique bears a strong similarity to thermal desorption spectroscopy (TDS), where the sample is heated linearly and the rate of desorption is measured as a function of temperature and heating rate.

Tryptophan 2,3-dioxygenase (TDO)-reactive T cells differ in their functional characteristics in health and cancer

DEFF Research Database (Denmark)

Hjortsø, Mads Duus; Larsen, Stine Kiaer; Kongsted, Per

2015-01-01

of different origin. Interestingly, the processed and presented TDO-derived epitopes varied between different cancer cells. With respect to CD4(+) TDO-reactive T cells, in vitro expanded T-cell cultures comprised a Th1 and/or a Treg phenotype. In summary, our data demonstrate that the immune modulating enzyme....... In the present study, we detected the presence of both CD8(+) and CD4(+) T-cell reactivity toward TDO in peripheral blood of patients with malignant melanoma (MM) or breast cancer (BC) as well as healthy subjects. However, TDO-reactive CD4(+) T cells constituted distinct functional phenotypes in health...... TDO is a target for CD8(+) and CD4(+) T cell responses both in healthy subjects as well as patients with cancer; notably, however, the functional phenotype of these T-cell responses differ depending on the respective conditions of the host....

Unique and cross-reactive T cell epitope peptides of the major Bahia grass pollen allergen, Pas n 1.

Science.gov (United States)

Etto, Tamara; de Boer, Carmela; Prickett, Sara; Gardner, Leanne M; Voskamp, Astrid; Davies, Janet M; O'Hehir, Robyn E; Rolland, Jennifer M

2012-01-01

Bahia grass pollen (BaGP) is a major cause of allergic rhinitis. Subcutaneous allergen-specific immunotherapy is effective for grass pollen allergy, but is unsuitable for patients with moderate to severe asthma due to the risk of anaphylaxis. T cell-reactive but IgE nonreactive peptides provide a safer treatment option. This study aimed to identify and characterize dominant CD4(+) T cell epitope peptides of the major BaGP allergen, Pas n 1. Pas n 1-specific T cell lines generated from the peripheral blood of BaGP-allergic subjects were tested for proliferative and cytokine response to overlapping 20-mer Pas n 1 peptides. Cross-reactivity to homologous peptides from Lol p 1 and Cyn d 1 of Ryegrass and Bermuda grass pollen, respectively, was assessed using Pas n 1 peptide-specific T cell clones. MHC class II restriction of Pas n 1 peptide T cell recognition was determined by HLA blocking assays and peptide IgE reactivity tested by dot blotting. Three Pas n 1 peptides showed dominant T cell reactivity; 15 of 18 (83%) patients responded to one or more of these peptides. T cell clones specific for dominant Pas n 1 peptides showed evidence of species-specific T cell reactivity as well as cross-reactivity with other group 1 grass pollen allergens. The dominant Pas n 1 T cell epitope peptides showed HLA binding diversity and were non-IgE reactive. The immunodominant T cell-reactive Pas n 1 peptides are candidates for safe immunotherapy for individuals, including those with asthma, who are allergic to Bahia and possibly other grass pollens. Copyright © 2012 S. Karger AG, Basel.

Reactivity effect of non-uniformly distributed fuel in fuel solution systems

International Nuclear Information System (INIS)

Hirano, Yasushi; Yamane, Yoshihiro; Nishina, Kojiro; Mitsuhashi, Ishi.

1991-01-01

A numerical method to determine the optimal fuel distribution for minimum critical mass, or maximum k-effective, is developed using the Maximum Principle in order to evaluate the maximum effect of non-uniformly distributed fuel on reactivity. This algorithm maximizes the Hamiltonian directly by an iterative method under a certain constraint-the maintenance of criticality or total fuel mass. It ultimately reaches the same optimal state of a flattened fuel importance distribution as another algorithm by Dam based on perturbation theory. This method was applied to two kinds of spherical cores with water reflector in the simulating reprocessing facility. In the slightly-enriched uranyl nitrate solution core, the minimum critical mass decreased by less than 1% at the optimal moderation state. In the plutonium nitrate solution core, the k-effective increment amounted up to 4.3% Δk within the range of present study. (author)

Hepatitis B virus reactivation during immunosuppressive therapy: Appropriate risk stratification.

Science.gov (United States)

Seto, Wai-Kay

2015-04-28

Our understanding of hepatitis B virus (HBV) reactivation during immunosuppresive therapy has increased remarkably during recent years. HBV reactivation in hepatitis B surface antigen (HBsAg)-positive individuals has been well-described in certain immunosuppressive regimens, including therapies containing corticosteroids, anthracyclines, rituximab, antibody to tumor necrosis factor (anti-TNF) and hematopoietic stem cell transplantation (HSCT). HBV reactivation could also occur in HBsAg-negative, antibody to hepatitis B core antigen (anti-HBc) positive individuals during therapies containing rituximab, anti-TNF or HSCT.For HBsAg-positive patients, prophylactic antiviral therapy is proven to the effective in preventing HBV reactivation. Recent evidence also demonstrated entecavir to be more effective than lamivudine in this aspect. For HBsAg-negative, anti-HBc positive individuals, the risk of reactivations differs with the type of immunosuppression. For rituximab, a prospective study demonstrated the 2-year cumulative risk of reactivation to be 41.5%, but prospective data is still lacking for other immunosupressive regimes. The optimal management in preventing HBV reactivation would involve appropriate risk stratification for different immunosuppressive regimes in both HBsAg-positive and HBsAg-negative, anti-HBc positive individuals.

Subjective effects of cannabis before the first psychotic episode

NARCIS (Netherlands)

Peters, Bart D.; de Koning, Pelle; Dingemans, Peter; Becker, Hiske; Linszen, Don H.; de Haan, Lieuwe

2009-01-01

Objective: The aim of the present study was to gain more insight into the positive and negative effects of cannabis in the prodromal phase of schizophrenia and in the ultrahigh-risk (UHR) state for psychosis. Method: A theory-driven questionnaire was used to examine subjective effects in the

Reactivity and burnout of wood fuels

Energy Technology Data Exchange (ETDEWEB)

Dall' Ora, M.

2011-07-01

This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile in the boiler and thereby the overall operation and efficiency of the plant. Chapter 1 consists of an introduction to thermal conversion of biomass fuels as well as a description of a Danish power plant where a measuring campaign was carried out as part of this project. Chapter 2 is a brief literature review of different aspects relevant to wood combustion, including wood structure and composition, wood pyrolysis, wood char properties and wood char oxidation. The full scale campaign, which is the subject of Chapter 3, included sampling of wood fuel before and after milling and sampling of gas and particles at the top of the combustion chamber. The collected samples and data are used to obtain an evaluation of the mills in operation at the power plant, the particle size distribution of the wood fuel, as well as the char conversion attained in the furnace. In Chapter 4 an experimental investigation on the relation between pyrolysis of wood in boiler-like conditions and wood char properties is presented. Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyser. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature varied in the range 673-1673 K for slow pyrolysis and 1073-1573 K for fast pyrolysis. The chars were oxidised in a thermogravimetric analyser and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104-105 K/s) was as low as 1-6% on a dry ash free basis, whereas it was about 15-17% for slow pyrolysis (10-20 K/min); char yield decreased as

Process effects on radio frequency diode reactively sputtered ZrO2 films

International Nuclear Information System (INIS)

Yang, M.M.; Reith, T.M.; Lin, C.J.

1990-01-01

The ZrO 2 thin film is deposited by means of a reactive radio frequency diode sputtering from an elemental zirconium target in an argon--oxygen mixture gas. The influence of the deposition process parameters on the microinstructure, composition, film stress, and refractive index is investigated. It is noted that the process parameters, in particular substrate bias, have a profound effect on the structure and properties. The possible mechanism, in terms of bombardment of energetic particles and adatom mobility on the film surface, is discussed

BN600 reactivity definition

International Nuclear Information System (INIS)

Zheltyshev, V.; Ivanov, A.

2000-01-01

Since 1980, the fast BN600 reactor with sodium coolant has been operated at Beloyarsk Nuclear Power Plant. The periodic monitoring of the reactivity modifications should be implemented in compliance with the standards and regulations applied in nuclear power engineering. The reactivity measurements are carried out in order to confirm the basic neutronic features of a BN600 reactor. The reactivity measurements are aimed to justify that nuclear safety is provided in course of the in-reactor installation of the experimental core components. Two reactivity meters are to be used on BN600 operation: 1. Digital on-line reactivity calculated under stationary reactor operation on power (approximation of the point-wise kinetics is applied). 2. Second reactivity meter used to define the reactor control rod operating components efficiency under reactor startup and take account of the changing efficiency of the sensor, however, this is more time-consumptive than the on-line reactivity meter. The application of two reactivity meters allows for the monitoring of the reactor reactivity under every operating mode. (authors)

Reduced enrichment fuel and its reactivity effects in the University Training Reactor Moata

International Nuclear Information System (INIS)

Wilson, D.J.

1983-08-01

Concern for nuclear proliferation is likely to preclude future supply of highly enriched uranium fuel for research reactors such as the University Training Reactor Moata. This study calculates the fuel densities necessary to maintain the reactivity per plate of the present high enrichment (90 per cent 235 U) fuel for a range of lower enrichments assuming that no geometry changes are allowed. The maximum uranium density for commercially available aluminium-type research reactor fuels is generally considered to be about 1.7 g cm -3 . With this density limitation, the minimum enrichment to maintain present reactivity per plate is about 35 per cent 235 U. For low enrichment (max. 20 per cent 235 U) fuel, the required U density is about 2.9 g cm -3 , which is beyond the expected range for UAl/sub x/-Al but within that projected for the longer term development and full qualification for U 3 O 8 -Al. Medium enrichment (nominally 45 per cent 235 U) Al/sub x/-Al would be entirely satisfactory as an immediate replacement fuel, requiring no modifications to the reactor and operating procedures, and minimal reappraisal of safety issues. Included in this study are calculations of the fuel coefficients at various enrichments, the effect of replacing standard fuel plates or complete elements with 45 per cent enriched fuel, and the reactivity to be gained by replacing 12-plate with 13-plate elements

Effect of reactive and un-reactive substrates on photopolymerization of self-etching adhesives with different aggressiveness.

Science.gov (United States)

Zhang, Ying; Wang, Yong

2013-01-01

The study investigated the influence of reactive (enamel) and un-reactive (glass) substrates on photo-polymerization of self-etching adhesives. Two commercial adhesives Adper Prompt L-Pop (APLP, pH~0.8) and Adper Easy Bond (AEB, pH~2.5) were applied onto prepared enamel and glass substrates using the same protocol. Micro-Raman spectroscopy was employed to determine the degree of conversion (DC) and the involved mechanism. DC of APLP was dramatically enhanced from ~9.4% to ~82.0% as when changing from glass to enamel, while DC of AEB on both substrates showed no difference. The DC distributions along the adhesive layers of the APLP and AEB on enamel showed descending and constant trends, respectively. Spectral analysis disclosed that the difference in chemical reaction of the two adhesives with enamel might be associated with the results. The chemical reaction of the adhesives with enamel significantly improved the DC of the strong APLP, but not that of the mild AEB.

Luminometric determination of antioxidant capacity towards individual reactive oxygen species

Czech Academy of Sciences Publication Activity Database

Komrsková, D.; Lojek, Antonín; Hrbáč, J.; Číž, Milan

2005-01-01

Roč. 3, č. 1 (2005), S25 [Cells VI - Biological Days /18./. 24.10.2005-26.10.2005, České Budějovice] R&D Projects: GA ČR(CZ) GA524/01/1219 Institutional research plan: CEZ:AV0Z50040507 Keywords : chemiluminescence * reactive oxygen species * scavenger Subject RIV: BO - Biophysics

Chronic lead exposure decreases the vascular reactivity of rat aortas: the role of hydrogen peroxide.

Directory of Open Access Journals (Sweden)

Karolini Zuqui Nunes

Full Text Available We investigated whether exposure to small concentrations of lead alters blood pressure and vascular reactivity. Male Wistar rats were sorted randomly into the following two groups: control (Ct and treatment with 100 ppm of lead (Pb, which was added to drinking water, for 30 days. Systolic blood pressure (BP was measured weekly. Following treatment, aortic ring vascular reactivity was assessed. Tissue samples were properly stored for further biochemical investigation. The lead concentration in the blood reached approximately 8 μg/dL. Treatment increased blood pressure and decreased the contractile responses of the aortic rings to phenylephrine (1 nM-100 mM. Following N-nitro-L arginine methyl ester (L-NAME administration, contractile responses increased in both groups but did not differ significantly between them. Lead effects on Rmax were decreased compared to control subjects following superoxide dismutase (SOD administration. Catalase, diethyldithiocarbamic acid (DETCA, and apocynin increased the vasoconstrictor response induced by phenylephrine in the aortas of lead-treated rats but did not increase the vasoconstrictor response in the aortas of untreated rats. Tetraethylammonium (TEA potentiated the vasoconstrictor response induced by phenylephrine in aortic segments in both groups, but these effects were greater in lead-treated rats. The co-incubation of TEA and catalase abolished the vasodilatory effect noted in the lead group. The present study is the first to demonstrate that blood lead concentrations well below the values established by international legislation increased blood pressure and decreased phenylephrine-induced vascular reactivity. The latter effect was associated with oxidative stress, specifically oxidative stress induced via increases in hydrogen peroxide levels and the subsequent effects of hydrogen peroxide on potassium channels.

Multi-site exploration of sex differences in brain reactivity to smoking cues: Consensus across sites and methodologies.

Science.gov (United States)

Dumais, Kelly M; Franklin, Teresa R; Jagannathan, Kanchana; Hager, Nathan; Gawrysiak, Michael; Betts, Jennifer; Farmer, Stacey; Guthier, Emily; Pater, Heather; Janes, Amy C; Wetherill, Reagan R

2017-09-01

Biological sex influences cigarette smoking behavior. More men than women smoke, but women have a harder time quitting. Sex differences in smoking cue (SC) reactivity may underlie such behavioral differences. However, the influence of sex on brain reactivity to SCs has yielded inconsistent findings suggesting the need for continued study. Here, we investigated the effect of sex on SC reactivity across two sites using different imaging modalities and SC stimulus types. Pseudo-continuous arterial spin-labeled (pCASL) perfusion functional magnetic resonance imaging (fMRI) was used to assess brain responses to SC versus non-SC videos in 40 smokers (23 females) at the University of Pennsylvania. BOLD fMRI was used to assess brain responses to SC versus non-SC still images in 32 smokers (18 females) at McLean Hospital. Brain reactivity to SCs was compared between men and women and was correlated with SC-induced craving. In both cohorts, males showed higher SC versus non-SC reactivity compared to females in reward-related brain regions (i.e., ventral striatum/ventral pallidum, ventral medial prefrontal cortex). Brain activation during SC versus non-SC exposure correlated positively with SC-induced subjective craving in males, but not females. The current work provides much needed replication and validation of sex differences in SC-reactivity. These findings also add to a body of literature showing that men have greater reward-related brain activation to drug cues across drug classes. Such sex differences confirm the need to consider sex not only when evaluating SC-reactivity but when examining nicotine dependence etiology and treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Memory Reactivation Enables Long-Term Prevention of Interference.

Science.gov (United States)

Herszage, Jasmine; Censor, Nitzan

2017-05-22

The ability of the human brain to successively learn or perform two competing tasks constitutes a major challenge in daily function. Indeed, exposing the brain to two different competing memories within a short temporal offset can induce interference, resulting in deteriorated performance in at least one of the learned memories [1-4]. Although previous studies have investigated online interference and its effects on performance [5-13], whether the human brain can enable long-term prevention of future interference is unknown. To address this question, we utilized the memory reactivation-reconsolidation framework [2, 12] stemming from studies at the synaptic level [14-17], according to which reactivation of a memory enables its update. In a set of experiments, using the motor sequence learning task [18] we report that a unique pairing of reactivating the original memory (right hand) in synchrony with novel memory trials (left hand) prevented future interference between the two memories. Strikingly, these effects were long-term and observed a month following reactivation. Further experiments showed that preventing future interference was not due to practice per se, but rather specifically depended on a limited time window induced by reactivation of the original memory. These results suggest a mechanism according to which memory reactivation enables long-term prevention of interference, possibly by creating an updated memory trace integrating original and novel memories during the reconsolidation time window. The opportunity to induce a long-term preventive effect on memories may enable the utilization of strategies optimizing normal human learning, as well as recovery following neurological insults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reactivity considerations for the on-line refuelling of a pebble bed modular reactor—Illustrating safety for the most reactive core fuel load

International Nuclear Information System (INIS)

Reitsma, Frederik

2012-01-01

In the multi-pass fuel management scheme employed for the pebble bed modular reactor the fuel pebbles are re-circulated until they reach the target burn-up. The rate at which fresh fuel is loaded and burned fuel is discharged is a result of the core neutronics cycle analysis but in practice (on the plant) this has to be controlled and managed by the fuel handling and storage system and use of the burnup measurement system. The excess reactivity is the additional reactivity available in the core during operating conditions that is the result of loading a fuel mixture in the core that is more reactive (less burned) than what is required to keep the reactor critical at full power operational conditions. The excess reactivity is balanced by the insertion of the control rods to keep the reactor critical. The excess reactivity allows flexibility in operations, for example to overcome the xenon build up when power is decreased as part of load follow. In order to limit reactivity excursions and to ensure safe shutdown the excess reactivity and thus the insertion depth of the control rods at normal operating conditions has to be managed. One way to do this is by operational procedures. The reactivity effect of long-term operation with the control rods inserted deeper than the design point is investigated and a control rod insertion limit is proposed that will not limit normal operations. The effects of other phenomena that can increase the power defect, such as higher-than-expected fuel temperatures, are also introduced. All of these cases are then evaluated by ensuring cold shutdown is still achievable and where appropriate by reactivity insertion accident analysis. These aspects are investigated on the PBMR 400 MW design.

Stress reactivity and personality in extreme sport athletes: The psychobiology of BASE jumpers.

Science.gov (United States)

Monasterio, Erik; Mei-Dan, Omer; Hackney, Anthony C; Lane, Amy R; Zwir, Igor; Rozsa, Sandor; Cloninger, C Robert

2016-12-01

This is the first report of the psychobiology of stress in BASE jumpers, one of the most dangerous forms of extreme sport. We tested the hypotheses that indicators of emotional style (temperament) predict salivary cortisol reactivity, whereas indicators of intentional goal-setting (persistence and character) predict salivary alpha-amylase reactivity during BASE jumping. Ninety-eight subjects completed the Temperament and Character Inventory (TCI) the day before the jump, and 77 also gave salivary samples at baseline, pre-jump on the bridge over the New River Gorge, and post-jump upon landing. Overall BASE jumpers are highly resilient individuals who are highly self-directed, persistent, and risk-taking, but they are heterogeneous in their motives and stress reactivity in the Hypothalamic-Pituitary-Adrenal (HPA) stress system (cortisol reactivity) and the sympathetic arousal system (alpha-amylase reactivity). Three classes of jumpers were identified using latent class analysis based on their personality profiles, prior jumping experience, and levels of cortisol and alpha-amylase at all three time points. "Masterful" jumpers (class 1) had a strong sense of self-directedness and mastery, extensive prior experience, and had little alpha-amylase reactivity and average cortisol reactivity. "Trustful" jumpers (class 2) were highly cooperative and trustful individuals who had little cortisol reactivity coincident with the social support they experienced prior to jumping. "Courageous" jumpers (class 3) were determined despite anxiety and inexperience, and they had high sympathetic reactivity but average cortisol activation. We conclude that trusting social attachment (Reward Dependence) and not jumping experience predicted low cortisol reactivity, whereas persistence (determination) and not jumping experience predicted high alpha-amylase reactivity. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Reactivation of the Shock-Tunnel Facility at Fort Cronkhite. Final report

International Nuclear Information System (INIS)

1982-05-01

This final report describes the results of work undertaken to reactivate the Shock Tunnel Facility at Battery Townsley, Fort Cronkhite, Marin County, California. The facility has been reactivated and can not be utilized for blast testing. The major emphasis will be testing of concepts pertaining to programs of interest to the Federal Emergency Management Agency (FEMA) and in particular to civil defense oriented research. However, a wide variety of testing requirements can be accommodated. For example, past programs at the facility have included: tests of debris from trees subjected to blast for Bell Telephone Laboratories; tests of the response of aluminum hull panels to blast loading and of the response of a model surface effects ship for the Naval Ship Research and Development center, and tests of the response of a radome prototype to blast loading conducted for ANCOM (the radome manufacturer). The Shock Tunnel Facility is located in a former coastal defense 16-inch gun emplacement constructed by the US Army beginning in 1938. It was converted in 1967 to serve as a facility for full-scale testing of the loading and response of structural elements and civil defense equipment. It remained in operation until November 1976 when Battery Townsley was turned over to the National Park Service. Work under the present purchase order consisted of the following major tasks: (I) cleanup and secure the facility, (II) reactivate the shock tunnel, and (III) design permanent facility improvements

Subjective, behavioral, and physiological effects of acute caffeine in light, nondependent caffeine users.

Science.gov (United States)

Childs, Emma; de Wit, Harriet

2006-05-01

Caffeine produces mild psychostimulant effects that are thought to underlie its widespread use. However, the direct effects of caffeine are difficult to evaluate in regular users of caffeine because of tolerance and withdrawal. Indeed, some researchers hypothesize that the psychostimulant effects of caffeine are due largely to the reversal of withdrawal and question whether there are direct effects of caffeine consumption upon mood, alertness, or mental performance in nondependent individuals. This study investigated the physiological, subjective, and behavioral effects of 0, 50, 150, and 450 mg caffeine in 102 light, nondependent caffeine users. Using a within-subjects design, subjects participated in four experimental sessions, in which they received each of the four drug conditions in random order under double blind conditions. Participants completed subjective effects questionnaires and vital signs were measured before and at repeated time points after drug administration. Forty minutes after the capsules were ingested, subjects completed behavioral tasks that included tests of sustained attention, short-term memory, psychomotor performance, and behavioral inhibition. Caffeine significantly increased blood pressure, and produced feelings of arousal, positive mood, and high. Caffeine increased the number of hits and decreased reaction times in a vigilance task, but impaired performance on a memory task. We confirm that acute doses of caffeine, at levels typically found in a cup of coffee, produce stimulant-like subjective effects and enhance performance in light, nondependent caffeine users. These findings support the idea that the drug has psychoactive effects even in the absence of withdrawal.

Reactivation of organophosphate-inhibited human acetylcholinesterase by isonitrosoacetone (MINA): a kinetic analysis.

Science.gov (United States)

Worek, Franz; Thiermann, Horst

2011-11-15

Treatment of poisoning by highly toxic organophosphorus compounds (OP) with atropine and an acetylcholinesterase (AChE) reactivator (oxime) is of limited effectiveness in case of different nerve agents and pesticides. One challenge is the reactivation of OP-inhibited brain AChE which shows inadequate success with charged pyridinium oximes. Recent studies with high doses of the tertiary oxime isonitrosoacetone (MINA) indicated a beneficial effect on central and peripheral AChE and on survival in nerve agent poisoned guinea pigs. Now, an in vitro study was performed to determine the reactivation kinetics of MINA with tabun-, sarin-, cyclosarin-, VX- and paraoxon-inhibited human AChE. MINA showed an exceptionally low affinity to inhibited AChE but, with the exception of tabun-inhibited AChE, a moderate to high reactivity. In comparison to the pyridinium oximes obidoxime, 2-PAM and HI-6 the affinity and reactivity of MINA was in most cases lower and in relation to the most effective reactivators, the second order reactivation constant of MINA was 500 to 3400-fold lower. Hence, high in vivo MINA concentrations would be necessary to achieve at least partial reactivation. This assumption corresponds to in vivo data showing a dose-dependent effect on reactivation and survival in animals. In view, of the toxic potential of MINA in animals human studies would be necessary to determine the tolerability and pharmacokinetics of MINA in order to enable a proper assessment of the value of this oxime as an antidote in OP poisoning. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Biological Reactive Intermediates (BRIs) Formed from Botanical Dietary Supplements

Science.gov (United States)

Dietz, Birgit M.; Bolton, Judy L.

2013-01-01

The use of botanical dietary supplements is increasingly popular, due to their natural origin and the perceived assumption that they are safer than prescription drugs. While most botanical dietary supplements can be considered safe, a few contain compounds, which can be converted to reactive biological reactive intermediates (BRIs) causing toxicity. For example, sassafras oil contains safrole, which can be converted to a reactive carbocation forming genotoxic DNA adducts. Alternatively, some botanical dietary supplements contain stable BRIs such as simple Michael acceptors that react with chemosensor proteins such as Keap1 resulting in induction of protective detoxification enzymes. Examples include curcumin from turmeric, xanthohumol from hops, and Z-ligustilide from dang gui. Quinones (sassafras, kava, black cohosh), quinone methides (sassafras), and epoxides (pennyroyal oil) represent BRIs of intermediate reactivity, which could generate both genotoxic and/or chemopreventive effects. The biological targets of BRIs formed from botanical dietary supplements and their resulting toxic and/or chemopreventive effects are closely linked to the reactivity of BRIs as well as dose and time of exposure. PMID:20970412

Effect of static porosity fluctuations on reactive transport in a porous medium

Science.gov (United States)

L'Heureux, Ivan

2018-02-01

Reaction-diffusive transport phenomena in porous media are ubiquitous in engineering applications, biological and geochemical systems. The porosity field is usually random in space, but most models consider the porosity field as a well-defined deterministic function of space and time and ignore the porosity fluctuations. They use a reaction-diffusion equation written in terms of an average porosity and average concentration fields. In this contribution, we treat explicitly the effect of spatial porosity fluctuations on the dynamics of a concentration field for the case of a one-dimensional reaction-transport system with nonlinear kinetics. Three basic assumptions are considered. (i) The porosity fluctuations are assumed to have Gaussian properties and an arbitrary variance; (ii) we assume that the noise correlation length is small compared to the relevant macroscopic length scale; (iii) and we assume that the kinetics of the reactive term in the equations for the fluctuations is a self-consistently determined constant. Elimination of the fluctuating part of the concentration field from the dynamics leads to a renormalized equation involving the average concentration field. It is shown that the noise leads to a renormalized (generally smaller) diffusion coefficient and renormalized kinetics. Within the framework of the approximations used, numerical simulations are in agreement with our theory. We show that the porosity fluctuations may have a significant effect on the transport of a reactive species, even in the case of a homogeneous average porosity.

Gas-Phase Reactivity of Microsolvated Anions

DEFF Research Database (Denmark)

Thomsen, Ditte Linde

the gas-phase α-effect. The experimental studies are performed by means of the flowing after glow selected ion flow tube technique, and these are supplemented by electronic structure calculations. The α-nucleophile employed is the microsolvated hydrogen peroxide anion whose reactivity is compared......Gas-phase studies of ion-molecule reactions shed light on the intrinsic factors that govern reactivity; and even solvent effects can be examined in the gasphase environment by employing microsolvated ions. An area that has received considerable attention with regard to the interplay between...... to that of a series of microsolvated oxygen centered anions. The association of the nucleophiles with a single water or methanol molecule allows the α-effect to be observed in the SN2 reaction with methyl chloride; this effect was not apparent in the reactions of the unsolvated anions. The results suggest...

Subjective knowledge and fear appeal effectiveness: implications for message design.

Science.gov (United States)

Nabi, Robin L; Roskos-Ewoldsen, David; Carpentier, Francesca Dillman

2008-01-01

This research investigates the role of perceived health knowledge on the effectiveness of fear-based persuasive appeals. Undergraduates (N = 263) read a strong fear, weak fear, or efficacy-only message encouraging breast or testicular self-examination. As expected, results indicated that men high in subjective knowledge were less reactant and more persuaded by the efficacy-only message whereas those low in subjective knowledge did not evidence this pattern. Contrary to expectation, women high in subjective knowledge had comparable reactions to each of the 3 messages. Implications for fear appeal theory and message design are discussed.

A simultaneous modulation of reactive and proactive inhibition processes by anodal tDCS on the right inferior frontal cortex.

Directory of Open Access Journals (Sweden)

Toni Cunillera

Full Text Available Proactive and reactive inhibitory processes are a fundamental part of executive functions, allowing a person to stop inappropriate responses when necessary and to adjust performance in in a long term in accordance to the goals of a task. In the current study, we manipulate, in a single task, both reactive and proactive inhibition mechanisms, and we investigate the within-subjects effect of increasing, by means of anodal transcranial direct current stimulation (tDCS, the involvement of the right inferior frontal cortex (rIFC. Our results show a simultaneous enhancement of these two cognitive mechanisms when modulating the neural activity of rIFC. Thus, the application of anodal tDCS increased reaction times on Go trials, indicating a possible increase in proactive inhibition. Concurrently, the stop-signal reaction time, as a covert index of the inhibitory process, was reduced, demonstrating an improvement in reactive inhibition. In summary, the current pattern of results validates the engagement of the rIFC in these two forms of inhibitory processes, proactive and reactive inhibition and it provides evidence that both processes can operate concurrently in the brain.

Influence of the physicochemical and aromatic properties on the chemical reactivity and its relation with carcinogenic and anticoagulant effect of 17β-aminoestrogens

Energy Technology Data Exchange (ETDEWEB)

Soriano-Correa, Catalina, E-mail: socc@puma2.zaragoza.unam.mx [Química Computacional, FES-Zaragoza, Universidad Nacional Autónoma de México (UNAM), Iztapalapa, Mexico City (Mexico); Raya, Angélica [Unidad Profesional Interdisciplinaria de Ingeniería Campus Guanajuato, Instituto Politécnico Nacional (IPN), Silao de la Victoria, Guanajuato (Mexico); Barrientos-Salcedo, Carolina [Laboratorio de Química Médica y Quimiogenómica, Facultad de Bioanálisis Campus Veracruz - Boca del Río, Universidad Veracruzana, Veracruz (Mexico); Esquivel, Rodolfo O. [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa (UAM-Iztapalapa), Mexico City (Mexico)

2014-06-25

Highlights: • The aromatic A-ring of 17β-aminoestrogens contribute to its anticoagulant effect. • The electron-donor substituent groups favored the basicity of 17β-aminoestrogens. • The physicochemical properties are important in the carcinogenic effect of anticoagulant molecules. - Abstract: Activity of steroid hormones is dependent upon a number of factors, as solubility, transport and metabolism. The functional differences caused by structural modifications could exert an influence on the chemical reactivity and biological effect. The goal of this work is to study the influence of the physicochemical and aromatic properties on the chemical reactivity and its relation with the carcinogenic risk that can associate with the anticoagulant effect of 17β-aminoestrogens using quantum-chemical descriptors at the DFT-B3LYP, BH and HLYP and M06-2X levels. The relative acidity of (H1) of the hydroxyl group increases with electron-withdrawing groups. Electron-donor groups favor the basicity. The steric hindrance of the substituents decreases the aromatic character and consequently diminution the carcinogenic effect. Density descriptors: hardness, electrophilic index, atomic charges, molecular orbitals, electrostatic potential and their geometric parameters permit analyses of the chemical reactivity and physicochemical features and to identify some reactive sites of 17β-aminoestrogens.

The synergistic effect of chemical carcinogens enhances Epstein-Barr virus reactivation and tumor progression of nasopharyngeal carcinoma cells.

Science.gov (United States)

Fang, Chih-Yeu; Huang, Sheng-Yen; Wu, Chung-Chun; Hsu, Hui-Yu; Chou, Sheng-Ping; Tsai, Ching-Hwa; Chang, Yao; Takada, Kenzo; Chen, Jen-Yang

2012-01-01

Seroepidemiological studies imply a correlation between Epstein-Barr virus (EBV) reactivation and the development of nasopharyngeal carcinoma (NPC). N-nitroso compounds, phorbols, and butyrates are chemicals found in food and herb samples collected from NPC high-risk areas. These chemicals have been reported to be risk factors contributing to the development of NPC, however, the underlying mechanism is not fully understood. We have demonstrated previously that low dose N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 0.1 µg/ml) had a synergistic effect with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate (SB) in enhancing EBV reactivation and genome instability in NPC cells harboring EBV. Considering that residents in NPC high-risk areas may contact regularly with these chemical carcinogens, it is vital to elucidate the relation between chemicals and EBV and their contributions to the carcinogenesis of NPC. In this study, we constructed a cell culture model to show that genome instability, alterations of cancer hallmark gene expression, and tumorigenicity were increased after recurrent EBV reactivation in NPC cells following combined treatment of TPA/SB and MNNG. NPC cells latently infected with EBV, NA, and the corresponding EBV-negative cell, NPC-TW01, were periodically treated with MNNG, TPA/SB, or TPA/SB combined with MNNG. With chemically-induced recurrent reactivation of EBV, the degree of genome instability was significantly enhanced in NA cells treated with a combination of TPA/SB and MNNG than those treated individually. The Matrigel invasiveness, as well as the tumorigenicity in mouse, was also enhanced in NA cells after recurrent EBV reactivation. Expression profile analysis by microarray indicates that many carcinogenesis-related genes were altered after recurrent EBV reactivation, and several aberrations observed in cell lines correspond to alterations in NPC lesions. These results indicate that cooperation between chemical carcinogens can

Effects of lutein-enriched egg yolk in buttermilk or skimmed milk on serum lipids & lipoproteins of mildly hypercholesterolemic subjects.

Science.gov (United States)

Severins, N; Mensink, R P; Plat, J

2015-02-01

Earlier studies in our group suggested that traditionally prepared buttermilk influences cholesterol metabolism. We therefore designed a study to evaluate whether traditionally prepared buttermilk lowers serum low-density lipoprotein cholesterol (LDL-C) and/or prevents the LDL-C raising effect of egg yolks. Mildly hypercholesterolemic subjects were randomly allocated to one of four diet groups consuming daily at lunch 80 ml skimmed milk with (n = 23) or without (n = 25) lutein-enriched egg yolk (28 g from 1.5 eggs providing 323 mg cholesterol) or traditionally prepared buttermilk with (n = 23) or without (n = 21) lutein-enriched egg yolk during a 12 week period. Fasting blood samples were taken to measure concentrations of serum lipids, (apo)lipoproteins, liver and kidney function markers, and plasma lutein, zeaxanthin and high-sensitive C-reactive protein (hsCRP). Egg yolk consumption significantly increased serum total cholesterol (total-C) (p = 0.035) and LDL-C concentrations (p = 0.022). Buttermilk did not change the effects of egg yolk on serum lipids and (apo)lipoproteins. There was a trend towards significant lower total-C (p = 0.077), but not LDL-C (p = 0.204) concentrations in the buttermilk groups. Plasma lutein and zeaxanthin concentrations increased significantly (p < 0.001) in the egg yolk groups. In mildly hypercholesterolemic subjects, daily consumption of traditionally prepared buttermilk for 12 weeks did not lower serum total-C or LDL-C concentrations, nor did it prevent the serum total-C and LDL-C raising effect of daily egg yolk consumption. This study is registered at www.clinicaltrials.gov as NCT01566305. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of teacher interpersonal behaviour on students' subject-specific motivation

NARCIS (Netherlands)

den Brok, P.; Levy, J.; Brekelmans, M.; Wubbels, Th.

2006-01-01

This study brings together insights from research on teaching and learning in specific subjects, learning environments research and effectiveness research by linking teacher interpersonal behaviour to students’ subject-related attitudes. Teaching was studied in terms of a model originating from

Administration of deuterium depletion water and physiological effect of Japanese subjects

International Nuclear Information System (INIS)

Kunihiro, Seki

2003-01-01

It is from February, 2002 that Deuterium Depletion Water (DDW) was imported by Japan from Hungary. Since then studies were undertaken on normal and patient Japanese subjects to observe the effect of DDW for a long period of time, and the side effects of its administration. Three types of DDW administration were undertaken and the following results are report. Normal male subject was made to consume DDW-105 ppm one liter per day, every day for one year. The stiffness of the shoulders disappeared in normal subjects men and women. The benign neoplasm disappeared. Lack of sleep sensation disappeared. The old-man skin liver spots disappeared. The male sex function was recovered. The airsickness of jet traveling abroad disappeared. In the second type of experiments a 250 liters bath of DDW-105 ppm was administrated and the normal subject was made to take a bath for 20 minutes in water temperature of 39 deg C every day for seven days in a row. The humidity effect of the skin before and after bathing, the liver spots of the skin, weight, and subjective-symptoms investigation were investigated. Side effects or changes in skin aspects were not observed after the bathing experiment. In the third case the patient was made to consume DDW-105 ppm or 25 ppm, and changes of the tumor marker following the administration were measured. In the subjects SK (Kanagawa 58 years old) who suffered from the extramammary Paget disease, it was observed that the value of the tumor marker TPA (Tissue polypeptide antigen) being 120U/L (normal value: 70U/L) at first fell to 58U/L after six months. In a case of prostatic cancer in a 64 years old HT male subject of Tokyo the tumor marker PSA (prostatic specific antigen) was 6.2 ng/ml (normal value: 4.0 ng/ml) in July, 2002. Two months after drinking DDW-105 ppm, it fell to 4.2 ng/ml. A prostatic cancer was excised and all tumor markers also reached a normal value in February, 2003. Now, subject HT consume of DDW-105 one liter every day. His face

Deposition of zinc oxide thin films by reactive pulsed laser ablation

Czech Academy of Sciences Publication Activity Database

Bílková, Petra; Zemek, Josef; Mitu, B.; Marotta, V.; Orlando, S.

2006-01-01

Roč. 252, - (2006), s. 4604-4609 ISSN 0169-4332 Grant - others:NATO-CNR Outreach Fellowships Programm 2001(XE) 219.34 Institutional research plan: CEZ:AV0Z10100521 Keywords : reactive pulsed laser deposition * zinc oxide * thin films Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.436, year: 2006

Association of BDNF Val66Met polymorphism with HPA and SAM axis reactivity to psychological and physical stress.

Science.gov (United States)

Tsuru, Jusen; Tanaka, Yoshihiro; Ishitobi, Yoshinobu; Maruyama, Yoshihiro; Inoue, Ayako; Kawano, Aimi; Ikeda, Rie; Ando, Tomoko; Oshita, Harumi; Aizawa, Saeko; Masuda, Koji; Higuma, Haruka; Kanehisa, Masayuki; Ninomiya, Taiga; Akiyoshi, Jotaro

2014-01-01

Decreased expression of brain-derived neurotrophic factor (BDNF) is implicated in enhanced stress responses. The BDNF Val66Met polymorphism is associated with psychological changes; for example, carriers of the Met allele exhibit increased harm avoidance as well as a higher prevalence of depression and anxiety disorder. To analyze the effects of BDNF Val66Met on stress responses, we tested 226 university students (88 women and 138 men) using a social stress procedure (Trier Social Stress Test [TSST]) and an electrical stimulation stress test. Stress indices were derived from repeated measurements of salivary α-amylase, salivary cortisol, heart rate, and psychological testing during the stress tests. All subjects were genotyped for the Val66Met polymorphism (G196A). A significant three-way interaction (time [3 levels] × BDNF [Val/Val, Val/Met, Met/Met]; PBDNF had different effects on hypothalamic-pituitary-adrenocortical axis reactivity but not on sympathetic adrenomedullary reactivity in TSST and electrical stimulation tests.

AIREKMOD-RR, Reactivity Transients in Nuclear Research Reactors

International Nuclear Information System (INIS)

Baggoura, B.; Mazrou, H.

2001-01-01

1 - Description of program or function: AIREMOD-RR is a point kinetics code which can simulate fast transients in nuclear research reactor cores. It can also be used for theoretical reactor dynamics studies. It is used for research reactor kinetic analysis and provides a point neutron kinetic capability. The thermal hydraulic behavior is governed by a one-dimensional heat balance equation. The calculations are restricted to a single equivalent unit cell which consists of fuel, clad and coolant. 2 - Method of solution: For transient reactor kinetic calculations a modified Runge Kutta numerical method is used. The external reactivity insertion, specified as a function of time, is converted in dollar ($) unit. The neutron density, energy release and feedback variables are given at each time step. The two types of reactivity feedback considered are: Doppler effect and moderator effect. A new expression for the reactivity dependence on the feedback variables has been introduced in the present version of the code. The feedback reactivities are fitted in power series expression. 3 - Restrictions on the complexity of the problem: The number of delayed neutron groups and the total number of equations are limited only by computer storage capabilities. - Coolant is always in liquid phase. - Void reactivity feedback is not considered

Method of controlling reactivity

International Nuclear Information System (INIS)

Tochihara, Hiroshi.

1982-01-01

Purpose: To improve the reactivity controlling characteristics by artificially controlling the leakage of neutron from a reactor and providing a controller for controlling the reactivity. Method: A reactor core is divided into several water gaps to increase the leakage of neutron, its reactivity is reduced, a gas-filled control rod or a fuel assembly is inserted into the gap as required, the entire core is coupled in a system to reduce the leakage of the neutron, and the reactivity is increased. The reactor shutdown is conducted by the conventional control rod, and to maintain critical state, boron density varying system is used together. Futher, a control rod drive is used with that similar to the conventional one, thereby enabling fast reactivity variation, and the positive reactivity can be obtained by the insertion, thereby improving the reactivity controlling characteristics. (Yoshihara, H.)

Reactive Arthritis

Directory of Open Access Journals (Sweden)

Eren Erken

2013-06-01

Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

Effects of nutritional supplementation on periodontal parameters, carotenoid antioxidant levels, and serum C-reactive protein.

Science.gov (United States)

Harpenau, Lisa A; Cheema, Abida T; Zingale, Joseph A; Chambers, David W; Lundergan, William P

2011-05-01

Few studies have focused on the role of nutrition in periodontal disease. The purpose of this trial was to determine the effect of a nutritional supplement on gingival inflammation, bleeding, probing depth, clinical attachment level, carotenoid antioxidant level, and C-reactive protein. The test supplement, consisting of a standard multivitamin formula, as well as several phytonutrients associated with antiinflammatory/antioxidant effects, provided modest benefits in reducing inflammation; however, further studies with larger populations and longer intervention are warranted.

Chemical stability and in chemico reactivity of 24 fragrance ingredients of concern for skin sensitization risk assessment.

Science.gov (United States)

Avonto, Cristina; Wang, Mei; Chittiboyina, Amar G; Vukmanovic, Stanislav; Khan, Ikhlas A

2018-02-01

Twenty-four pure fragrance ingredients have been identified as potential concern for skin sensitization. Several of these compounds are chemically unstable and convert into reactive species upon exposure to air or light. In the present work, a systematic investigation of the correlation between chemical stability and reactivity has been undertaken. The compounds were subjected to forced photodegradation for three months and the chemical changes were studied with GC-MS. At the end of the stability study, two-thirds of the samples were found to be unstable. The generation of chemically reactive species was investigated using the in chemico HTS-DCYA assay. Eleven and fourteen compounds were chemically reactive before and after three months, respectively. A significant increase in reactivity upon degradation was found for isoeugenol, linalool, limonene, lyral, citronellol and geraniol; in the same conditions, the reactivity of hydroxycitronellal decreased. The non-reactive compounds α-isomethyl ionone, benzyl alcohol, amyl cinnamal and farnesol became reactive after photo-oxidative degradation. Overall, forced degradation resulted in four non-reactive fragrance compounds to display in chemico thiol reactivity, while ten out of 24 compounds remained inactive. Chemical degradation does not necessarily occur with generation of reactive species. Non-chemical activation may be involved for the 10 stable unreactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method of reactivity control in pressure tube reactor

International Nuclear Information System (INIS)

Fukumura, Nobuo.

1988-01-01

Purpose: To provide a method of controlling reactivity in a pressure tube reactor at high conversion ratio intended for high burn-up degree. Method: Control tubes are inserted in heavy water moderator. Light water is filled in the tubes at the initial burning stage. Along with the advance of the burning, the light water is gradually removed and replaced with gases of less reactive nuclear reactivity with neutrons such as air or gaseous carbon dioxide. The tubes are made of less neutron absorbing material such as aluminum. By filling light water, infinite multiplication factor is reduced to suppress the reactivity at the initial burning stage. As light water is gradually removed and replaced with air, etc., it provides an effect like that elimination of heavy water moderator to increase the conversion ratio. Accordingly, nuclear fission materials are produced additionally by so much to extend the burn-up degree. In this way, it can provide excellent effect in realizing high burn-up ratio and high conversion ratio. (Kamimura, M.)

Quantification of Hydroxyl Radical reactivity in the urban environment using the Comparative Reactivity Method (CRM)

Science.gov (United States)

Panchal, Rikesh; Monks, Paul

2015-04-01

Hydroxyl (OH) radicals play an important role in 'cleansing' the atmosphere of many pollutants such as, NOx, CH4 and various VOCs, through oxidation. To measure the reactivity of OH, both the sinks and sources of OH need to be quantified, and currently the overall sinks of OH seem not to be fully constrained. In order to measure the total rate loss of OH in an ambient air sample, all OH reactive species must be considered and their concentrations and reaction rate coefficients with OH known. Using the method pioneered by Sinha and Williams at the Max Plank Institute Mainz, the Comparative Reactivity Method (CRM) which directly quantifies total OH reactivity in ambient air without the need to consider the concentrations of individual species within the sample that can react with OH, has been developed and applied in a urban setting. The CRM measures the concentration of a reactive species that is present only in low concentrations in ambient air, in this case pyrrole, flowing through a reaction vessel and detected using Proton Transfer Reaction - Mass Spectrometry (PTR-MS). The poster will show a newly developed and tested PTR-TOF-MS system for CRM. The correction regime will be detailed to account for the influence of the varying humidity between ambient air and clean air on the pyrrole signal. Further, examination of the sensitivity dependence of the PTR-MS as a function of relative humidity and H3O+(H2O) (m/z=37) cluster ion allows the correction for the humidity variation, between the clean humid air entering the reaction vessel and ambient air will be shown. NO, present within ambient air, is also a potential interference and can cause recycling of OH, resulting in an overestimation of OH reactivity. Tests have been conducted on the effects of varying NO concentrations on OH reactivity and a correction factor determined for application to data when sampling ambient air. Finally, field tests in the urban environment at the University of Leicester will be shown

Reactive gastropathy is associated with inflammatory conditions throughout the gastrointestinal tract.

Science.gov (United States)

Maguilnik, I; Neumann, W L; Sonnenberg, A; Genta, R M

2012-10-01

The epidemiology of reactive gastropathy and its relationship with other conditions of the gastrointestinal tract associated with NSAID use have not been evaluated. To test the hypothesis that if reactive gastropathy shares common aetiological factors with these conditions, the analysis of a large cohort would unveil associations. We queried a national pathology database for subjects with a diagnosis of reactive gastropathy; controls were patients with normal gastric biopsies. We also extracted diagnoses of H. pylori infection, intestinal metaplasia, duodenal lymphocytosis, duodenitis, ileitis, microscopic colitis and focal colitis. Of 504 011 patients with gastric biopsies, 69 101 had oesophageal, 166 134 duodenal, 13 010 ileal and 83 334 colonic biopsies. Reactive gastropathy was diagnosed in 15.6% of patients, H. pylori infection in 10.3% and normal gastric mucosa in 16.3%. Reactive gastropathy was evenly distributed across the US and increased from 2.0% in the first decade of life to >20% in octogenarians. Compared with controls, reactive gastropathy was significantly associated with Barrett's mucosa (OR 1.21 95% CI 1.16-129); duodenitis (OR 1.36; 95% CI 1.28-1.44); duodenal intraepithelial lymphocytosis (OR 1.25; 95% CI 1.13-1.39); active ileitis (OR 1.88; 95% CI 1.47-2.40); focal active colitis (OR 1.57; 95% CI 1.33-1.86); and collagenous colitis (OR 1.50; 95% CI 1.12-2.03). Reactive gastropathy, a common histopathological feature of the stomach, shows an age-dependent rise and is associated with changes of the digestive tract believed to be caused by NSAID use or duodenogastric reflux. However, a large fraction of reactive gastropathy remains unexplained; its frequent occurrence merits further efforts at elucidating its aetiology. © 2012 Blackwell Publishing Ltd.

Reactive modification of polyesters and their blends

Science.gov (United States)

Wan, Chen

2004-12-01

As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

Effect of nonsurgical periodontal therapy verses oral hygiene instructions on type 2 diabetes subjects with chronic periodontitis: a randomised clinical trial.

Science.gov (United States)

Raman, Renukanth Patabi Cheta; Taiyeb-Ali, Tara Bai; Chan, Siew Pheng; Chinna, Karuthan; Vaithilingam, Rathna Devi

2014-06-25

40 subjects with type 2 diabetes and moderate to severe CP were randomly distributed to groups receiving either NSPT or OHI. Periodontal parameters, glycosylated haemoglobin (HbA1c) and high-sensitivity C-reactive protein (hs-CRP) were evaluated at baseline, 2- and 3-months intervals. 40 subjects with type 2 diabetes and moderate to severe CP were randomly distributed to groups receiving either NSPT or OHI. Periodontal parameters, glycosylated haemoglobin (HbA1c) and high-sensitivity C-reactive protein (hs-CRP) were evaluated at baseline, 2- and 3-months intervals. 15 subjects from NSPT group and 17 from OHI group completed the study. The difference in plaque index (PI) between NSPT and OHI groups were significant at 2 months recall (p = 0.013). There was no significant difference between NSPT and OHI group for all other clinical periodontal parameters, HbA1c and CRP levels. At 3 months post-therapy, periodontal parameters improved significantly in both groups with sites with probing pocket depth (PPD) c levels decreased in both groups with NSPT group recording statistically significant reduction (p = 0.038). Participants who demonstrated ≥ 50% reduction in PPD showed significant reductions of HbA1c and hs-CRP levels (p = 0.004 and p = 0.012). NSPT significantly reduced PI at 2 months post-therapy as compared to OHI. Both NSPT and OHI demonstrated improvements in other clinical parameters as well as HbA1c and CRP levels. ClinicalTrials.gov: NCT01951547.

The diagnostic value of c-reactive protein estimation in differentiating bacterial from viral meningitis

International Nuclear Information System (INIS)

Sheikh, A.

2001-01-01

Objective: To evaluate the efficacy of serum and CSF C-reactive protein (C-rp) in differentiating bacterial from viral meningitis. Design: An observational, respective hospital-based study. Place and duration of study: It was conducted at the Department of Medicine and Department of Pediatrics, Shaikh Zayed Postgraduate Medical Institute Lahore, Over a Period of one year between march, 1999 and March, 2000. Subject and Methods: A randomized group of thirty patients, who presented with clinical features, suggestive of meningitis, were included in the study. C-reactive protein determinations were performed by latex agglutination method on the serum and cerebrospinal fluid (CSF) of these patients. Results: In the present study, c-reactive protein was found to be a more sensitive test for differentiating bacterial from non-bacterial meningitis on initial examination than the usual conventional methods used to diagnose bacterial meningitis. CSF C-reactive protein had a greater sensitivity (92% as compared to serum C-reactive protein (71%). Conclusion: C-reactive protein determination in CSF was found to be a useful indicator of bacterial meningitis that can be used to distinguish it from viral meningitis. (author)

Cardiovascular reactivity to acute psychological stress following sleep deprivation.

Science.gov (United States)

Franzen, Peter L; Gianaros, Peter J; Marsland, Anna L; Hall, Martica H; Siegle, Greg J; Dahl, Ronald E; Buysse, Daniel J

2011-10-01

Psychological stress and sleep disturbances are highly prevalent and are both implicated in the etiology of cardiovascular diseases. Given the common co-occurrence of psychological distress and sleep disturbances including short sleep duration, this study examined the combined effects of these two factors on blood pressure reactivity to immediate mental challenge tasks after well-rested and sleep-deprived experimental conditions. Participants (n = 20) were healthy young adults free from current or past sleep, psychiatric, or major medical disorders. Using a within-subjects crossover design, we examined acute stress reactivity under two experimental conditions: after a night of normal sleep in the laboratory and after a night of total sleep deprivation. Two standardized psychological stress tasks were administered, a Stroop color-word naming interference task and a speech task, which were preceded by a prestress baseline period and followed by a poststress recovery period. Each period was 10 minutes in duration, and blood pressure recordings were collected every 2.5 minutes throughout each period. Mean blood pressure responses during stress and recovery periods were examined with a mixed-effects analysis of covariance, controlling for baseline blood pressure. There was a significant interaction between sleep deprivation and stress on systolic blood pressure (F(2,82.7) = 4.05, p = .02). Systolic blood pressure was higher in the sleep deprivation condition compared with the normal sleep condition during the speech task and during the two baseline periods. Sleep deprivation amplified systolic blood pressure increases to psychological stress. Sleep loss may increase cardiovascular risk by dysregulating stress physiology.

Chaetocin reactivates the lytic replication of Epstein-Barr virus from latency via reactive oxygen species.

Science.gov (United States)

Zhang, Shilun; Yin, Juan; Zhong, Jiang

2017-01-01

Oxidative stress, regarded as a negative effect of free radicals in vivo, takes place when organisms suffer from harmful stimuli. Some viruses can induce the release of reactive oxygen species (ROS) in infected cells, which may be closely related with their pathogenicity. In this report, chaetocin, a fungal metabolite reported to have antimicrobial and cytostatic activity, was studied for its effect on the activation of latent Epstein-Barr virus (EBV) in B95-8 cells. We found that chaetocin remarkably up-regulated EBV lytic transcription and DNA replication at a low concentration (50 nmol L -1 ). The activation of latent EBV was accompanied by an increased cellular ROS level. N-acetyl-L-cysteine (NAC), an ROS inhibitor, suppressed chaetocin-induced EBV activation. Chaetocin had little effect on histone H3K9 methylation, while NAC also significantly reduced H3K9 methylation. These results suggested that chaetocin reactivates latent EBV primarily via ROS pathways.

Reactive Strength Index: A Poor Indicator of Reactive Strength?

Science.gov (United States)

Healy, Robin; Kenny, Ian; Harrison, Drew

2017-11-28

The primary aim was to assess the relationships between reactive strength measures and associated kinematic and kinetic performance variables achieved during drop jumps. A secondary aim was to highlight issues with the use of reactive strength measures as performance indicators. Twenty eight national and international level sprinters, consisting of fourteen men and women, participated in this cross-sectional analysis. Athletes performed drop jumps from a 0.3 m box onto a force platform with dependent variables contact time (CT), landing time (TLand), push-off time (TPush), flight time (FT), jump height (JH), reactive strength index (RSI, calculated as JH / CT), reactive strength ratio (RSR, calculated as FT / CT) and vertical leg spring stiffness (Kvert) recorded. Pearson's correlation test found very high to near perfect relationships between RSI and RSR (r = 0.91 to 0.97), with mixed relationships found between RSI, RSR and the key performance variables, (Men: r = -0.86 to -0.71 between RSI/RSR and CT, r = 0.80 to 0.92 between RSI/RSR and JH; Women: r = -0.85 to -0.56 between RSR and CT, r = 0.71 between RSI and JH). This study demonstrates that the method of assessing reactive strength (RSI versus RSR) may be influenced by the performance strategies adopted i.e. whether an athlete achieves their best reactive strength scores via low CTs, high JHs or a combination. Coaches are advised to limit the variability in performance strategies by implementing upper and / or lower CT thresholds to accurately compare performances between individuals.

Oral tartrazine challenge in childhood asthma: effect on bronchial reactivity.

Science.gov (United States)

Hariparsad, D; Wilson, N; Dixon, C; Silverman, M

1984-01-01

Ten asthmatic children who gave a history of cough or wheeze after orange drinks, were tested for tartrazine sensitivity. On separate days, either oral tartrazine (1 mg) or a placebo capsule were administered double blind. Bronchial reactivity was measured before, 30 and 60 min after ingestion by means of a histamine-inhalation challenge test. There was no change in baseline lung function after tartrazine, but histamine sensitivity (PC20) increased significantly in four of the children. No response was obtained to a larger dose of tartrazine (10 mg) in four of the non-responders. Alteration in the bronchial reactivity after an oral challenge, appears to be a sensitive means of detecting tartrazine sensitivity.

Effects of ω-3 Fatty Acid Supplementation on Glycemic Status and Hhigh Sensitive C-Reactive Protein in Women with Polycystic Ovary Syndrome

Directory of Open Access Journals (Sweden)

Maryam Rafraf

2012-12-01

Full Text Available Background & Objectives: Polycystic ovary syndrome (PCOS is one of the major endocrine disorders among females. PCOS is associated with development of type 2 diabetes and cardiovascular disease. The objectives of this study were to determine the effects of omega-3 fatty acids on glycemic status and high sensitive C-reactive protein in women with PCOS.   Methods: This double-blind randomized controlled clinical trial was conducted on 61 PCOS patients. Subjects in ω-3 fatty acids (n=30 and placebo (n=31 groups take 4 ω-3 fatty acids capsules (each one contained 180 mg eicosapentaenoic acid and 120 mg docosahexanoic acid or placebo daily for 8 weeks. Anthropometric and biochemical measurments and food intakes were assessed at the beginning and at the end of the study.   Results: ω-3 fatty acid supplementation caused significant decrease in serum levels of glucose, insulin (p 0.05.   Conclusion: ω-3 fatty acid supplementation had some beneficial effects on glycemic status of PCOS patients and may be useful in prevention and control of metabolic conmplication of this syndrome.

Humic acid effect on catalase activity and the generation of reactive oxygen species in corn (Zea mays).

Science.gov (United States)

Cordeiro, Flávio Couto; Santa-Catarina, Claudete; Silveira, Vanildo; de Souza, Sonia Regina

2011-01-01

Humic acids (HAs) have positive effects on plant physiology, but the molecular mechanisms underlying these events are only partially understood. The induction of root growth and emission of lateral roots (LRs) promoted by exogenous auxin is a natural phenomenon. Exogenous auxins are also associated with HA. Gas nitric oxide (NO) is a secondary messenger produced endogenously in plants. It is associated with metabolic events dependent on auxin. With the application of auxin, NO production is significantly increased, resulting in positive effects on plant physiology. Thus it is possible to evaluate the beneficial effects of the application of HA as an effect of auxin. To investigate the effects of HA the parameters of root growth, Zea mays was studied by evaluating the application of 3 mM C L⁻¹ of HA extracted from Oxisol and 100 µM SNP (sodium nitroprusside) and the NO donor, subject to two N-NO₃⁻, high dose (5.0 mM N-NO₃⁻) and low dose (5.0 mM N-NO₃⁻). Treatments with HA and NO were positively increased, regardless of the N-NO₃⁻ taken, as assessed by fresh weight and dry root, issue of LRs. The effects were more pronounced in the treatment with a lower dose of N-NO₃⁻. Detection of reactive oxygen species (ROS) in vivo and catalase activity were evaluated; these tests were associated with root growth. Under application of the bioactive substances tested, detection of ROS and catalase activity increased, especially in treatments with lower doses of N-NO₃⁻. The results of this experiment indicate that the effects of HA are dependent on ROS generation, which act as a messenger that induces root growth and the emission of LRs.

Effect of Casmo-5 cross-section data and doppler temperature definitions on LWR reactivity initiated accidents - 166

International Nuclear Information System (INIS)

Grandi, G.; Smith, K.; Xu, Z.; Rhodes, J.

2010-01-01

During LWR Reactivity Initiated Accidents (RIA), the accurate evaluation of the Doppler reactivity feedback depends on the Doppler coefficient computed by the lattice physics code (e.g. CASMO-5), and on the effective Doppler temperature computed by the transient code (e.g. SIMULATE-3K) using the non-uniform intra-pellet temperature profile. CASMO-5 has many new features compared with its predecessor. Among them, the replacement of the L-library (based primarily on ENDF/B IV data) by the latest available nuclear data (ENDF/B VII.0), and the Monte Carlo based resonance elastic scattering model to overcome deficiencies in NJOY modeling have a significant impact on the fuel temperature coefficient, and hence on LWR RIA. The Doppler temperature effect in thermal reactors is driven by the 238 U absorption. The different effective Doppler temperature definitions, available in the literature, try to capture the considerable self-shielding of the 238 U absorption that occurs in the pellet surface by defining an appropriate fuel temperature to compute cross-sections. In this work, we investigate the effect of the nuclear data generated by CASMO-5 on RIA, as well as the impact of different effective Doppler temperature definitions, including one proposed by the authors. It is concluded: 1) LWR RIA evaluated using CASMO-5 cross section data will be milder because the energy released is ∼10% smaller; 2) the prompt enthalpy rise is barely affected by the choice of the Doppler temperature definition; and 3) the peak fuel enthalpy is affected by the choice of the Doppler temperature definition, the under-prediction of the Doppler reactivity by the 'NEA' Doppler temperature results in a conservative estimate of the peak fuel enthalpy. (authors)

A Numerical Study on the Effects of Street‒canyon Aspect‒ratio on Reactive Pollutant Dispersion

Science.gov (United States)

Park, S. J.; Kim, J.

2014-12-01

In this study, the effects of street‒canyon aspect‒ratio on reactive pollutant dispersion were investigated using the coupled CFD‒chemistry model. For this, flow characteristics were analyzed first in street canyons with different aspect ratios and flow regimes were classified according to the building height. For each flow regime, dispersion characteristics were investigated in views of reactive pollutant concentration and VOCs‒NOX ratio. Finally, the relations between pollutant concentration and aspect ratio in urban street canyons were investigated. In the case of H/S = 1.0 (H is building height and S is street width), one clockwise‒rotating vortex appeared vertically and the reverse and outward flows were dominant near the street bottom. In the case of H/S = 2.0, two counter‒rotating vortices appeared vertically in the street canyon. The primary (secondary) vortex rotating clockwise (counterclockwise) was formed in upper (lower) layer. The flow patterns affected the reactive pollutant concentration in street canyons. As building height increased, mean concentration of NO decreased when one vortex was generated in street canyons and increased when two vortexes appeared in street canyons. O3 concentration showed almost contrasted tendency with those of NO because O3 was depleted by the NO titration.

HIF and reactive oxygen species regulate oxidative phosphorylation in cancer

Czech Academy of Sciences Publication Activity Database

Hervouet, E.; Čížková, Alena; Demont, J.; Vojtíšková, Alena; Pecina, Petr; Franssen-van Hal, N.; Keijer, J.; Simonnet, H.; Ivánek, Robert; Kmoch, S.; Godinot, C.; Houštěk, Josef

2008-01-01

Roč. 29, č. 8 (2008), s. 1528-1537 ISSN 0143-3334 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GA303/07/0781 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z50520514 Keywords : carcinoma * mitochondrial biogenesis * reactive oxygen species Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.930, year: 2008

Effect of ectomycorrhizal colonization and drought on reactive oxygen species metabolism of Nothofagus dombeyi roots.

Science.gov (United States)

Alvarez, Maricel; Huygens, Dries; Fernandez, Carlos; Gacitúa, Yessy; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Infection with ectomycorrhizal fungi can increase the ability of plants to resist drought stress through morphophysiological and biochemical mechanisms. However, the metabolism of antioxidative enzyme activities in the ectomycorrhizal symbiosis remains poorly understood. This study investigated biomass production, reactive oxygen metabolism (hydrogen peroxide and malondialdehyde concentration) and antioxidant enzyme activity (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in pure cultures of the ectomycorrhizal fungi Descolea antartica Sing. and Pisolithus tinctorius (Pers.) Coker & Couch, and non-mycorrhizal and mycorrhizal roots of Nothofagus dombeyi (Mirb.) roots under well-watered conditions and drought conditions (DC). The studied ectomycorrhizal fungi regulated their antioxidative enzyme metabolism differentially in response to drought, resulting in cellular damage in D. antartica but not in P. tinctorius. Ectomycorrhizal inoculation and water treatment had a significant effect on all parameters studied, including relative water content of the plant. As such, N. dombeyi plants in symbiosis experienced a lower oxidative stress effect than non-mycorrhizal plants under DC. Additionally, ectomycorrhizal N. dombeyi roots showed a greater antioxidant enzyme activity relative to non-mycorrhizal roots, an effect which was further expressed under DC. The association between the non-specific P. tinctorius and N. dombeyi had a more effective reactive oxygen species (ROS) metabolism than the specific D. antartica-N. dombeyi symbiosis. We conclude that the combination of effective ROS prevention and ROS detoxification by ectomycorrhizal plants resulted in reduced cellular damage and increased plant growth relative to non-mycorrhizal plants under drought.

Interaction of UV laser pulses with reactive dusty plasmas

NARCIS (Netherlands)

van de Wetering, F.M.J.H.; Beckers, J.; Nijdam, S.; Oosterbeek, W.; Kovacevic, E.; Berndt, J.

2016-01-01

This contribution deals with the effects of UV photons on the synthesis and transport of nanoparticles in reactive complex plasmas (capacitively coupled RF discharge). First measurements showed that the irradiation of a reactive acetylene-argon plasma with high-energy, ns UV laser pulses (355 nm, 75

Reactivity measurement in estimation of benzoquinone and benzoquinone derivatives’ allergenicity

International Nuclear Information System (INIS)

Mbiya, Wilbes; Chipinda, Itai; Simoyi, Reuben H.; Siegel, Paul D.

2016-01-01

Benzoquinone (BQ) and benzoquinone derivatives (BQD) are used in the production of dyes and cosmetics. While BQ, an extreme skin sensitizer, is an electrophile known to covalently modify proteins via Michael Addition (MA) reaction whilst halogen substituted BQD undergo nucleophilic vinylic substitution (SNV) mechanism onto amine and thiol moieties on proteins, the allergenic effects of adding substituents on BQ have not been reported. The effects of inserting substituents on the BQ ring has not been studied in animal assays. However, mandated reduction/elimination of animals used in cosmetics testing in Europe has led to an increased need for alternatives for the prediction of skin sensitization potential. Electron withdrawing and electron donating substituents on BQ were assessed for effects on BQ reactivity toward nitrobenzene thiol (NBT). The NBT binding studies demonstrated that addition of EWG to BQ as exemplified by the chlorine substituted BQDs increased reactivity while addition of EDG as in the methyl substituted BQDs reduced reactivity. BQ and BQD skin allerginicity was evaluated in the murine local lymph node assay (LLNA). BQD with electron withdrawing groups had the highest chemical potency followed by unsubstituted BQ and the least potent were the BQD with electron donating groups. The BQD results demonstrate the impact of inductive effects on both BQ reactivity and allergenicity, and suggest the potential utility of chemical reactivity data for electrophilic allergen identification and potency ranking.

Reactivity measurement in estimation of benzoquinone and benzoquinone derivatives’ allergenicity

Science.gov (United States)

Mbiya, Wilbes; Chipinda, Itai; Simoyi, Reuben H.; Siegel, Paul D.

2015-01-01

Benzoquinone (BQ) and benzoquinone derivatives (BQD) are used in the production of dyes and cosmetics. While BQ, an extreme skin sensitizer, is an electrophile known to covalently modify proteins via Michael Addition (MA) reaction whilst halogen substituted BQD undergo nucleophilic vinylic substitution (SNV) mechanism onto amine and thiol moieties on proteins, the allergenic effects of adding substituents on BQ have not been reported. The effects of inserting substituents on the BQ ring has not been studied in animal assays. However, mandated reduction/elimination of animals used in cosmetics testing in Europe has led to an increased need for alternatives for the prediction of skin sensitization potential. Electron withdrawing and electron donating substituents on BQ were assessed for effects on BQ reactivity toward nitrobenzene thiol (NBT). The NBT binding studies demonstrated that addition of EWG to BQ as exemplified by the chlorine substituted BQDs increased reactivity while addition of EDG as in the methyl substituted BQDs reduced reactivity. BQ and BQD skin allerginicity was evaluated in the murine local lymph node assay (LLNA). BQD with electron withdrawing groups had the highest chemical potency followed by unsubstituted BQ and the least potent were the BQD with electron donating groups. The BQD results demonstrate the impact of inductive effects on both BQ reactivity and allergenicity, and suggest the potential utility of chemical reactivity data for electrophilic allergen identification and potency ranking. PMID:26612505

Evidence for greater cue reactivity among low-dependent vs. high-dependent smokers.

Science.gov (United States)

Watson, Noreen L; Carpenter, Matthew J; Saladin, Michael E; Gray, Kevin M; Upadhyaya, Himanshu P

2010-07-01

Cue reactivity paradigms are well-established laboratory procedures used to examine subjective craving in response to substance-related cues. For smokers, the relationship between nicotine dependence and cue reactivity has not been clearly established. The main aim of the present study was to further examine this relationship. Participants (N=90) were between the ages 18-40 and smoked > or =10 cigarettes per day. Average nicotine dependence (Fagerström Test for Nicotine Dependence; FTND) at baseline was 4.9 (SD=2.1). Participants completed four cue reactivity sessions consisting of two in vivo cues (smoking and neutral) and two affective imagery cues (stressful and relaxed), all counterbalanced. Craving in response to cues was assessed following each cue exposure using the Questionnaire of Smoking Urges-Brief (QSU-B). Differential cue reactivity was operationally defined as the difference in QSU scores between the smoking and neutral cues, and between the stressful and relaxed cues. Nicotine dependence was significantly and negatively associated with differential cue reactivity scores in regard to hedonic craving (QSU factor 1) for both in vivo and imagery cues, such that those who had low FTND scores demonstrated greater differential cue reactivity than those with higher FTND scores (beta=-.082; p=.037; beta=-.101; p=.023, respectively). Similar trends were found for the Total QSU and for negative reinforcement craving (QSU factor 2), but did not reach statistical significance. Under partially sated conditions, less dependent smokers may be more differentially cue reactive to smoking cues as compared to heavily dependent smokers. These findings offer methodological and interpretative implications for cue reactivity studies. 2010 Elsevier Ltd. All rights reserved.

Cement reactivity in CO2 saturated brines: use of a reactive transport code to highlight key degradation mechanisms

International Nuclear Information System (INIS)

Huet, B.M.; Prevost, J.H.; Scherer, G.W.

2007-01-01

A modular reactive transport code is proposed to analyze the reactivity of cement in CO 2 saturated brine. The coupling of the transport module and the geochemical module within Dynaflow TM is derived. Both modules are coupled in a sequential iterative approach to accurately model: (1) mineral dissolution/precipitation and (2) porosity dependent transport properties. Results of the model reproduce qualitatively the dissolution of cement hydrates (C-H, C-S-H, AFm, AFt) and intermediate products (CaCO 3 ) into the brine. Slight discrepancies between modeling and experimental results were found concerning the dynamics of the mineral zoning. Results suggest that the power law relationship to model effective transport properties from porosity values is not accurate for very reactive case. (authors)

Reliability of the factor structure of the Multidimensional Scale of Interpersonal Reactivity (EMRI

Directory of Open Access Journals (Sweden)

Nilton S. Formiga

2013-10-01

Full Text Available This study aims to check the internal consistency and factor structure evaluative of the empathy scale in a high school and college sample in the state of Minas Gerais. The instruments that measure empathy can be easily found, however, of the existing, just multidimensional scale of interpersonal reactivity (Emri is the theoretical framework that has far more and better organized, and the scale that is most commonly used to assess this construct. Participated 488 subjects, male and female, with ages from 14-54 years old, distributed in primary and college levels in Patrocínio-MG composed this study sample. The subjects answered the Multidimensional Scale of Interpersonal Reactivity and socio-demographic data. From an equation analysis and structural modeling were observed psychometric indicators that assured the structural consistency of the scale, promoting in the security of the measure theoretical construct of empathy.

Large Amounts of Reactivated Virus in Tears Precedes Recurrent Herpes Stromal Keratitis in Stressed Rabbits Latently Infected with Herpes Simplex Virus.

Science.gov (United States)

Perng, Guey-Chuen; Osorio, Nelson; Jiang, Xianzhi; Geertsema, Roger; Hsiang, Chinhui; Brown, Don; BenMohamed, Lbachir; Wechsler, Steven L

2016-01-01

Recurrent herpetic stromal keratitis (rHSK), due to an immune response to reactivation of herpes simplex virus (HSV-1), can cause corneal blindness. The development of therapeutic interventions such as drugs and vaccines to decrease rHSK have been hampered by the lack of a small and reliable animal model in which rHSK occurs at a high frequency during HSV-1 latency. The aim of this study is to develop a rabbit model of rHSK in which stress from elevated temperatures increases the frequency of HSV-1 reactivations and rHSK. Rabbits latently infected with HSV-1 were subjected to elevated temperatures and the frequency of viral reactivations and rHSK were determined. In an experiment in which rabbits latently infected with HSV-1 were subjected to ill-defined stress as a result of failure of the vivarium air conditioning system, reactivation of HSV-1 occurred at over twice the normal frequency. In addition, 60% of eyes developed severe rHSK compared to tears of that eye and whenever this unusually large amount of reactivated virus was detected in tears, rHSK always appeared 4-5 days later. In subsequent experiments using well defined heat stress the reactivation frequency was similarly increased, but no eyes developed rHSK. The results reported here support the hypothesis that rHSK is associated not simply with elevated reactivation frequency, but rather with rare episodes of very high levels of reactivated virus in tears 4-5 days earlier.

Memory Reactivation during Rapid Eye Movement Sleep Promotes Its Generalization and Integration in Cortical Stores

Science.gov (United States)

Sterpenich, Virginie; Schmidt, Christina; Albouy, Geneviève; Matarazzo, Luca; Vanhaudenhuyse, Audrey; Boveroux, Pierre; Degueldre, Christian; Leclercq, Yves; Balteau, Evelyne; Collette, Fabienne; Luxen, André; Phillips, Christophe; Maquet, Pierre

2014-01-01

Study Objectives: Memory reactivation appears to be a fundamental process in memory consolidation. In this study we tested the influence of memory reactivation during rapid eye movement (REM) sleep on memory performance and brain responses at retrieval in healthy human participants. Participants: Fifty-six healthy subjects (28 women and 28 men, age [mean ± standard deviation]: 21.6 ± 2.2 y) participated in this functional magnetic resonance imaging (fMRI) study. Methods and Results: Auditory cues were associated with pictures of faces during their encoding. These memory cues delivered during REM sleep enhanced subsequent accurate recollections but also false recognitions. These results suggest that reactivated memories interacted with semantically related representations, and induced new creative associations, which subsequently reduced the distinction between new and previously encoded exemplars. Cues had no effect if presented during stage 2 sleep, or if they were not associated with faces during encoding. Functional magnetic resonance imaging revealed that following exposure to conditioned cues during REM sleep, responses to faces during retrieval were enhanced both in a visual area and in a cortical region of multisensory (auditory-visual) convergence. Conclusions: These results show that reactivating memories during REM sleep enhances cortical responses during retrieval, suggesting the integration of recent memories within cortical circuits, favoring the generalization and schematization of the information. Citation: Sterpenich V, Schmidt C, Albouy G, Matarazzo L, Vanhaudenhuyse A, Boveroux P, Degueldre C, Leclercq Y, Balteau E, Collette F, Luxen A, Phillips C, Maquet P. Memory reactivation during rapid eye movement sleep promotes its generalization and integration in cortical stores. SLEEP 2014;37(6):1061-1075. PMID:24882901

Atomoxetine in abstinent cocaine users: Cognitive, subjective and cardiovascular effects.

Science.gov (United States)

DeVito, Elise E; Herman, Aryeh I; Konkus, Noah S; Zhang, Huiping; Sofuoglu, Mehmet

2017-08-01

No pharmacotherapies are approved for the treatment of cocaine use disorders (CUD). Behavioral treatments for CUD are efficacious for some individuals, but recovery rates from CUD remain low. Cognitive impairments in CUD have been linked with poorer clinical outcomes. Cognitive enhancing pharmacotherapies have been proposed as promising treatments for CUD. Atomoxetine, a norepinephrine transporter inhibitor, shows potential as a treatment for CUD based on its efficacy as a cognitive enhancer in other clinical populations and impact on addictive processes in preclinical and human laboratory studies. In this randomized, double-blind, crossover study, abstinent individuals with CUD (N=39) received placebo, 40 and 80mg atomoxetine, over three sessions. Measures of attention, response inhibition and working memory; subjective medication effects and mood; and cardiovascular effects were collected. Analyses assessed acute, dose-dependent effects of atomoxetine. In addition, preliminary analyses investigating the modulation of atomoxetine dose effects by sex were performed. Atomoxetine increased heart rate and blood pressure, was rated as having positive and negative subjective drug effects, and had only modest effects on mood and cognitive enhancement. Copyright © 2017. Published by Elsevier Inc.

Reactive barriers for 137Cs retention

International Nuclear Information System (INIS)

Krumhansl, James L.; Brady, Patrick V.; Anderson, Howard L.

2000-01-01

137 Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137 Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137 Cs is only 30.2 years, remediation might be more effective (and less costly) if 137 Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135 Cs (half life 2.3x10 6 years) in addition to 137 Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO 3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

DMol3/COSMO-RS prediction of aqueous solubility and reactivity of selected Azo dyes: Effect of global orbital cut-off and COSMO segment variation

CSIR Research Space (South Africa)

Wahab, OO

2018-01-01

Full Text Available Aqueous solubility and reactivity of four azo dyes were investigated by DMol3/COSMO-RS calculation to examine the effects of global orbital cut-off and COSMO segment variation on the accuracies of theoretical solubility and reactivity. The studied...

Enhancing Reactivity in Structural Energetic Materials

Science.gov (United States)

Glumac, Nick

2017-06-01

In many structural energetic materials, only a small fraction of the metal oxidizes, and yet this provides a significant boost in the overall energy release of the system. Different methodologies to enhance this reactivity include alloying and geometric modifications of microstructure of the reactive material (RM). In this presentation, we present the results of several years of systematic study of both chemical (alloy) and mechanical (geometry) effects on reactivity for systems with typical charge to case mass ratios. Alloys of aluminum with magnesium and lithium are considered, as these are common alloys in aerospace applications. In terms of geometric modifications, we consider surface texturing, inclusion of dense additives, and inclusion of voids. In all modifications, a measurable influence on output is observed, and this influence is related to the fragment size distribution measured from the observed residue. Support from DTRA is gratefully acknowledged.

Effect of reactive monomer on PS-b-P2VP film.

Science.gov (United States)

Kim, H J; Shin, D M

2014-08-01

Poly(styrene-b-2-vinyl pyridine) (PS-b-P2VP) lamellar film which is hydrophobic block-hydrophilic polyelectrolyte block polymer of 52 kg/mol-b-57 kg/mol and PS-b-P2VP film with reactive monomer (RM257) were prepared for photonic gel films. The lamellar stacks, which is alternating layer of hydrophilic and hydrophobic moiety of PS-b-P2VP, were obtained by exposing the spin coated film under chloroform vapor. The lamellar films were quaternized with 5 wt% of iodomethane diluted by n-hexane. We reported about the influence of reactive monomer on those photonic gel films. Added reactive monomer photonic gel film had higher absorbance than pure photonic gel films. As a result the photonic gel film with RM had more clear color. The lamellar films were swollen by DI water, ethanol (aq) and calcium carbonate solution. The band gaps of the lamellar films were drastically shifted to longer wavelength swollen by calcium carbonate solution. And the lamellar films were shifted to shorter wave length swollen by ethanol. So each lamellar film showed different color.

C-Reactive Protein Levels in the Brugada Syndrome

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Aimé Bonny

2011-01-01

Full Text Available Background. Inflammation in the Brugada syndrome (BrS and its clinical implication have been little studied. Aims. To assess the level of inflammation in BrS patients. Methods. All studied BrS patients underwent blood samples drawn for C-reactive protein (CRP levels at admission, prior to any invasive intervention. Patients with a previous ICD placement were controlled to exclude those with a recent (<14 days shock. We divided subjects into symptomatic (syncope or aborted sudden death and asymptomatic groups. In a multivariable analysis, we adjusted for significant variables (age, CRP ≥ 2 mg/L. Results. Fifty-four subjects were studied (mean age 45 ± 13 years, 49 (91% male. Twenty (37% were symptomatic. Baseline characteristics were similar in both groups. Mean CRP level was 1,4 ± 0,9 mg/L in asymptomatic and 2,4 ± 1,4 mg/L in symptomatic groups (P = .003. In the multivariate model, CRP concentrations ≥ 2 mg/L remained an independent marker for being symptomatic (P = .018; 95% CI: 1.3 to 19.3. Conclusion. Inflammation seems to be more active in symptomatic BrS. C-reactive protein concentrations ≥ 2 mg/L might be associated with the previous symptoms in BrS. The value of inflammation as a risk factor of arrhythmic events in BrS needs to be studied.

Sildenafil increases cerebrovascular reactivity: a transcranial Doppler study.

Science.gov (United States)

Diomedi, M; Sallustio, F; Rizzato, B; Ferrante, F; Leone, G; Spera, E; Scarfini, M; Bernardi, G

2005-09-27

The authors performed a double-blind, placebo-controlled study in 28 patients to evaluate the effects of sildenafil on cerebral hemodynamics. A significant improvement of cerebrovascular reactivity, without any modification of other variables, was recorded 1 hour after the administration of 50 mg sildenafil. Further investigations are needed to evaluate whether cerebrovascular reactivity improvement could contribute to triggering sildenafil-induced migraine.

The action of red wine and purple grape juice on vascular reactivity is independent of plasma lipids in hypercholesterolemic patients

OpenAIRE

Coimbra, S.R.; Lage, S.H.; Brandizzi, L.; Yoshida, V.; da Luz, P.L.

2005-01-01

Although red wine (RW) reduces cardiovascular risk, the mechanisms underlying the effect have not been identified. Correction of endothelial dysfunction by RW flavonoids could be one mechanism. We measured brachial artery reactivity by high-resolution ultrasonography, plasma lipids, glucose, adhesion molecules (ICAM-1 and VCAM), and platelet function in 16 hypercholesterolemic individuals (8 men and 8 women; mean age 51.6 ± 8.1 years) without other risk factors. Twenty-four normal subjects we...

Effect of periodontal therapy on C-reactive protein levels in gingival crevicular fluid of patients with gingivitis and chronic periodontitis: A clinical and biochemical study.

Science.gov (United States)

Jayaprakash, Deepika; Aghanashini, Suchetha; Vijayendra, Ranganatha Rao; Chatterjee, Anirban; Rosh, Radhika Mohan; Bharwani, Ashit

2014-07-01

C-reactive protein (CRP) is a type I acute phase reactant. A number of studies have reported elevated serum CRP levels in periodontitis subjects, which decrease following periodontal therapy. However, the data of interventional studies on gingival crevicular fluid (GCF) levels of CRP is very scarce. The aim of the present study was to evaluate the effect of periodontal therapy on GCF CRP levels in patients with gingivitis and chronic periodontitis. A total of 60 subjects were included in the study with 20 subjects each in following groups: I-Healthy, II-Gingivitis, III-Mild periodontitis based on community periodontal index scores. Periodontal therapy was performed on Group II and Group III patients. GCF was collected from each subject at baseline and 3 months after periodontal therapy. The collected sample was subjected to biochemical analysis to detect CRP levels by using commercially available chemiluminescence immunoassay kit. The present study demonstrated that the periodontitis group had a higher mean CRP level (2.49 ± 0.47 ng/ml) when compared with the Gingivitis group (1.40 ± 0.32 ng/ml) and Healthy group (0.56 ± 0.20 ng/ml). The mean CRP values after periodontal therapy were found to be reduced to 0.44 ± 0.23 ng/ml in Group II and 1.30 ± 0.36 ng/ml in Group III patients. Within the limitations of this study, it can be concluded that GCF CRP level progressively increases from periodontal health to disease. It can also be stated that there is a decrease in GCF CRP levels with periodontal treatment.

Ultralow concentrations of bupivacaine exert anti-inflammatory effects on inflammation-reactive astrocytes

Science.gov (United States)

Block, Linda; Jörneberg, Per; Björklund, Ulrika; Westerlund, Anna; Biber, Björn; Hansson, Elisabeth

2013-01-01

Bupivacaine is a widely used, local anesthetic agent that blocks voltage-gated Na+ channels when used for neuro-axial blockades. Much lower concentrations of bupivacaine than in normal clinical use, bupivacaine exerts an influence on the Ca2+ signaling and interleukin-1β (IL-1β) secretion in inflammation-reactive astrocytes when used at ultralow concentrations, bupivacaine interacts with the opioid-, 5-hydroxytryptamine- (5-HT) and glutamate-receptor systems. With respect to the μ-opioid- and 5-HT-receptor systems, bupivacaine restored the inflammation-reactive astrocytes to their normal non-inflammatory levels. With respect to the glutamate-receptor system, bupivacaine, in combination with an ultralow concentration of the μ-opioid receptor antagonist naloxone and μ-opioid receptor agonists, restored the inflammation-reactive astrocytes to their normal non-inflammatory levels. Ultralow concentrations of bupivacaine attenuated the inflammation-induced upregulation of IL-1β secretion. The results indicate that bupivacaine interacts with the opioid-, 5-HT- and glutamate-receptor systems by affecting Ca2+ signaling and IL-1β release in inflammation-reactive astrocytes. These results suggest that bupivacaine may be used at ultralow concentrations as an anti-inflammatory drug, either alone or in combination with opioid agonists and ultralow concentrations of an opioid antagonist. PMID:24083665

Reactivity on the Web

OpenAIRE

Bailey, James; Bry, François; Eckert, Michael; Patrânjan, Paula Lavinia

2005-01-01

Reactivity, the ability to detect simple and composite events and respond in a timely manner, is an essential requirement in many present-day information systems. With the emergence of new, dynamic Web applications, reactivity on the Web is receiving increasing attention. Reactive Web-based systems need to detect and react not only to simple events but also to complex, real-life situations. This paper introduces XChange, a language for programming reactive behaviour on the Web,...

Altered Brain Activities Associated with Craving and Cue Reactivity in People with Internet Gaming Disorder: Evidence from the Comparison with Recreational Internet Game Users

Directory of Open Access Journals (Sweden)

Lingxiao Wang

2017-07-01

Full Text Available Although the neural substrates of cue reactivity in Internet gaming disorder (IGD have been examined in previous studies, most of these studies focused on the comparison between IGD subjects and healthy controls, which cannot exclude a potential effect of cue-familiarity. To overcome this limitation, the current study focuses on the comparison between IGD subjects and recreational Internet game users (RGU who play online games recreationally but do not develop dependence. Data from 40 RGU and 30 IGD subjects were collected while they were performing an event-related cue reactivity task in the fMRI scanner. The results showed that the IGD subjects were associated with enhanced activation in the left orbitofrontal cortex (OFC and decreased activation in the right anterior cingulate cortex (ACC, right precuneus, left precentral gyrus and right postcentral gyrus in comparison with the RGU subjects. OFC is involved in reward evaluation and ACC is implicated in executive control function based on previous researches. Moreover, the activation of OFC were correlated with the desire for game-playing. Thus, the higher activation in OFC might suggests high desire for game playing, and the lower activation in ACC might indicates impaired ability in inhibiting the urge to gaming-related stimuli in IGD subjects. Additionally, decreased activation in the precuneus, the precentral and postcentral gyrus may suggest the deficit in disentangling from game-playing stimuli. These findings explain why IGD subjects develop dependence on game-playing while RGU subjects can play online games recreationally and prevent the transition from voluntary game-playing to eventually IGD.

Altered Brain Activities Associated with Craving and Cue Reactivity in People with Internet Gaming Disorder: Evidence from the Comparison with Recreational Internet Game Users.

Science.gov (United States)

Wang, Lingxiao; Wu, Lingdan; Wang, Yifan; Li, Hui; Liu, Xiaoyue; Du, Xiaoxia; Dong, Guangheng

2017-01-01

Although the neural substrates of cue reactivity in Internet gaming disorder (IGD) have been examined in previous studies, most of these studies focused on the comparison between IGD subjects and healthy controls, which cannot exclude a potential effect of cue-familiarity. To overcome this limitation, the current study focuses on the comparison between IGD subjects and recreational Internet game users (RGU) who play online games recreationally but do not develop dependence. Data from 40 RGU and 30 IGD subjects were collected while they were performing an event-related cue reactivity task in the fMRI scanner. The results showed that the IGD subjects were associated with enhanced activation in the left orbitofrontal cortex (OFC) and decreased activation in the right anterior cingulate cortex (ACC), right precuneus, left precentral gyrus and right postcentral gyrus in comparison with the RGU subjects. OFC is involved in reward evaluation and ACC is implicated in executive control function based on previous researches. Moreover, the activation of OFC were correlated with the desire for game-playing. Thus, the higher activation in OFC might suggests high desire for game playing, and the lower activation in ACC might indicates impaired ability in inhibiting the urge to gaming-related stimuli in IGD subjects. Additionally, decreased activation in the precuneus, the precentral and postcentral gyrus may suggest the deficit in disentangling from game-playing stimuli. These findings explain why IGD subjects develop dependence on game-playing while RGU subjects can play online games recreationally and prevent the transition from voluntary game-playing to eventually IGD.

Pistachio Allergy-Prevalence and In vitro Cross-Reactivity with Other Nuts

Directory of Open Access Journals (Sweden)

Reihaneh Noorbakhsh

2011-01-01

Conclusions: The results indicate that exposure of people to pistachio significantly affects the prevalence of its allergic reactions. In addition, it was observed that, among pistachio allergic subjects, such exposure may affect the co-sensitivities with other nuts, including cashew and almond. The plant taxonomic classification of pistachio and other tree nuts does appear to predict allergenic cross-reactivity.

Blood oxygen-level dependent functional assessment of cerebrovascular reactivity: Feasibility for intraoperative 3 Tesla MRI.

Science.gov (United States)

Fierstra, Jorn; Burkhardt, Jan-Karl; van Niftrik, Christiaan Hendrik Bas; Piccirelli, Marco; Pangalu, Athina; Kocian, Roman; Neidert, Marian Christoph; Valavanis, Antonios; Regli, Luca; Bozinov, Oliver

2017-02-01

To assess the feasibility of functional blood oxygen-level dependent (BOLD) MRI to evaluate intraoperative cerebrovascular reactivity (CVR) at 3 Tesla field strength. Ten consecutive neurosurgical subjects scheduled for a clinical intraoperative MRI examination were enrolled in this study. In addition to the clinical protocol a BOLD sequence was implemented with three cycles of 44 s apnea to calculate CVR values on a voxel-by-voxel basis throughout the brain. The CVR range was then color-coded and superimposed on an anatomical volume to create high spatial resolution CVR maps. Ten subjects (mean age 34.8 ± 13.4; 2 females) uneventfully underwent the intraoperative BOLD protocol, with no complications occurring. Whole-brain CVR for all subjects was (mean ± SD) 0.69 ± 0.42, whereas CVR was markedly higher for tumor subjects as compared to vascular subjects, 0.81 ± 0.44 versus 0.33 ± 0.10, respectively. Furthermore, color-coded functional maps could be robustly interpreted for a whole-brain assessment of CVR. We demonstrate that intraoperative BOLD MRI is feasible in creating functional maps to assess cerebrovascular reactivity throughout the brain in subjects undergoing a neurosurgical procedure. Magn Reson Med 77:806-813, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Beyond a good story: from Hawthorne Effect to reactivity in health professions education research.

Science.gov (United States)

Paradis, Elise; Sutkin, Gary

2017-01-01

Observational research is increasingly being used in health professions education (HPE) research, yet it is often criticised for being prone to observer effects (also known as the Hawthorne Effect), defined as a research participant's altered behaviour in response to being observed. This article explores this concern. First, this article briefly reviews the initial Hawthorne studies and the original formulation of the Hawthorne Effect, before turning to contemporary studies of the Hawthorne Effect in HPE and beyond. Second, using data from two observational studies (in the operating theatre and in the intensive care unit), this article investigates the Hawthorne Effect in HPE. Evidence of a Hawthorne Effect is scant, and amounts to little more than a good story. This is surprising given the foundational nature of the Hawthorne Studies in the social sciences and the prevalence of our concern with observer effects in HPE research. Moreover, the multiple and inconsistent uses of the Hawthorne Effect have left researchers without a coherent and helpful understanding of research participants' responses to observation. The authors' HPE research illustrates the complexity of observer effects in HPE, suggests that significant alteration of behaviour is unlikely in many research contexts, and shows how sustained contact with participants over time improves the quality of data collection. This article thus concludes with three recommendations: that researchers, editors and reviewers in the HPE community use the phrase 'participant reactivity' when considering the participant, observer and research question triad; that researchers invest in interpersonal relationships at their study site to mitigate the effects of altered behaviour; and that researchers use theory to make sense of participants' altered behaviour and use it as a window into the social world. The term 'participant reactivity' better reflects current scientific understandings of the research process and

Effectiveness of reactive case detection for malaria elimination in three archetypical transmission settings: a modelling study.

Science.gov (United States)

Gerardin, Jaline; Bever, Caitlin A; Bridenbecker, Daniel; Hamainza, Busiku; Silumbe, Kafula; Miller, John M; Eisele, Thomas P; Eckhoff, Philip A; Wenger, Edward A

2017-06-12

reactive case detection or mass drug campaigns. Reactive case detection is recommended only for settings where transmission has recently been reduced rather than all low-transmission settings. This is demonstrated in a modelling framework with strong out-of-sample accuracy across a range of transmission settings while including methodologies for understanding the most resource-effective allocations of health workers. This approach generalizes to providing a platform for planning rational scale-up of health systems based on locally-optimized impact according to simplified stratification.

Immunoglobulin-E reactivity to wine glycoproteins in heavy drinkers

DEFF Research Database (Denmark)

Gonzalez-Quintela, Arturo; Gomez-Rial, Jose; Valcarcel, Catalina

2011-01-01

and biological significance of IgE antibodies to N-glycans from wine glycoproteins in heavy drinkers. A structured questionnaire, skin prick tests, serum IgE levels, IgE-immunoblotting to wine extracts, and basophil activation tests were used to characterize 20 heavy drinkers and 10 control subjects. Eleven...... heavy drinkers (55%) showed IgE binding to proteins in wine extracts. The proteins were identified by mass spectrometry as grape-derived vacuolar invertase and thaumatin-like protein. Immunoblot reactivity was closely associated with the presence of IgE to CCDs and was inhibited by preincubation...... with a glycoconjugate containing bromelain-type N-glycans. The same conjugate, CCD-bearing allergens, and wine extracts activated basophils in patients with high-titer CCD-specific IgE but not in healthy controls. There was no relationship between immunoblot reactivity and consumption of any specific type of wine...

Cued Memory Reactivation During SWS Abolishes the Beneficial Effect of Sleep on Abstraction.

Science.gov (United States)

Hennies, Nora; Lambon Ralph, Matthew A; Durrant, Simon J; Cousins, James N; Lewis, Penelope A

2017-08-01

Extracting regularities from stimuli in our environment and generalizing these to new situations are fundamental processes in human cognition. Sleep has been shown to enhance these processes, possibly by facilitating reactivation-triggered memory reorganization. Here, we assessed whether cued reactivation during slow wave sleep (SWS) promotes the beneficial effect of sleep on abstraction of statistical regularities. We used an auditory statistical learning task, in which the benefit of sleep has been firmly established. Participants were exposed to a probabilistically determined sequence of tones and subsequently tested for recognition of novel short sequences adhering to this same statistical pattern in both immediate and delayed recall sessions. In different groups, the exposure stream was replayed during SWS in the night between the recall sessions (SWS-replay group), in wake just before sleep (presleep replay group), or not at all (control group). Surprisingly, participants who received replay in sleep performed worse in the delayed recall session than the control and the presleep replay group. They also failed to show the association between SWS and task performance that has been observed in previous studies and was present in the controls. Importantly, sleep structure and sleep quality did not differ between groups, suggesting that replay during SWS did not impair sleep but rather disrupted or interfered with sleep-dependent mechanisms that underlie the extraction of the statistical pattern. These findings raise important questions about the scope of cued memory reactivation and the mechanisms that underlie sleep-related generalization. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Systematic identification of cellular signals reactivating Kaposi sarcoma-associated herpesvirus.

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Fuqu Yu

2007-03-01

Full Text Available The herpesvirus life cycle has two distinct phases: latency and lytic replication. The balance between these two phases is critical for viral pathogenesis. It is believed that cellular signals regulate the switch from latency to lytic replication. To systematically evaluate the cellular signals regulating this reactivation process in Kaposi sarcoma-associated herpesvirus, the effects of 26,000 full-length cDNA expression constructs on viral reactivation were individually assessed in primary effusion lymphoma-derived cells that harbor the latent virus. A group of diverse cellular signaling proteins were identified and validated in their effect of inducing viral lytic gene expression from the latent viral genome. The results suggest that multiple cellular signaling pathways can reactivate the virus in a genetically homogeneous cell population. Further analysis revealed that the Raf/MEK/ERK/Ets-1 pathway mediates Ras-induced reactivation. The same pathway also mediates spontaneous reactivation, which sets the first example to our knowledge of a specific cellular pathway being studied in the spontaneous reactivation process. Our study provides a functional genomic approach to systematically identify the cellular signals regulating the herpesvirus life cycle, thus facilitating better understanding of a fundamental issue in virology and identifying novel therapeutic targets.

Nicotine enhances modulation of food-cue reactivity by leptin and ghrelin in the ventromedial prefrontal cortex.

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Kroemer, Nils B; Wuttig, Franziska; Bidlingmaier, Martin; Zimmermann, Ulrich S; Smolka, Michael N

2015-07-01

Endocrine signals such as ghrelin and leptin are known to modulate the mesocorticolimbic dopaminergic system and, consequently, show associations with food and drug reward. In animal models, nicotine was demonstrated to reduce body weight by attenuating food intake and effects of leptin and ghrelin are partly modulated by nicotinic acetylcholine receptors which hint at potential interactions. However, the neuropharmacological modulation of endocrine signals by nicotine in healthy humans remains to be tested experimentally. We used functional magnetic resonance imaging to investigate food-cue reactivity after an overnight fast and following a caloric load (oral glucose tolerance test, OGTT) in 26 healthy normal-weight never-smokers. Moreover, we administered either nicotine (2 mg) or placebo gums using a randomized cross-over design and assessed blood plasma levels of ghrelin and leptin. During fasting, nicotine administration decreased correlations with ghrelin levels in the mesocorticolimbic system whereas correlations with leptin were increased. After the OGTT, nicotine increased the modulatory effects of ghrelin and leptin on food-cue reactivity, particularly in the ventromedial prefrontal cortex (vmPFC) and the amygdala. Critically, this led to an indirect modulation of the behavioral 'appetizer effect' (i.e. cue-induced increases in subjective appetite) by homeostatic feedback signals via food-cue reactivity in vmPFC. We conclude that nicotine enhances the effect of ghrelin and leptin in the valuation and relevance network which might, in turn, reduce appetite. This highlights that amplifying the impact of homeostatic signals such as ghrelin and leptin in normal-weight individuals might hint at a mechanism contributing to nicotine's anorexic potential. © 2014 Society for the Study of Addiction.

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