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Sample records for conducted vasomotor responses

  1. Oxygen sensing and conducted vasomotor responses in mouse cremaster arterioles in situ

    DEFF Research Database (Denmark)

    Ngo, Thuc Anh; Jensen, Lars Jørn; Riemann, Mads Achen

    2010-01-01

    .0 +/- 4.9 mum) when changing from high (PO(2) = 242.5 +/- 13.3 mm Hg) to low (PO(2) = 22.5 +/- 4.8 mm Hg) oxygen tension as seen in the intact cremaster circulation (DeltaD = 18.7 +/- 1.0 mum). Blockade of NO synthases by L: -NAME and adenosine receptors by DPCPX had no effects on vasomotor responses...... to low or high oxygen. Induction of localized low (PO(2) = 23.3 +/- 5.7 mmHg) or high (PO(2) = 300.0 +/- 25.7 mm Hg) oxygen tension caused vasodilatation or -constriction locally and at a site 1,000 mum upstream (distantly). Glibenclamide blocker of ATP-sensitive K(+) channels inhibited vasodilatation...... and -constriction to low (PO(2) = 16.0 +/- 6.4 mm Hg) and high (PO(2) = 337.4 +/- 12.8 mm Hg) oxygen tension. 1) ATP-sensitive K(+) channels seem to mediate, at least in part, vasodilatation and vasoconstriction to low and high oxygen tension; 2) Red blood cells are not necessary for inducing vasodilatation...

  2. Origins of variation in conducted vasomotor responses

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Welsh, Donald G.; Holstein-Rathlou, Niels-Henrik

    2015-01-01

    , the efficacy of conducted responses varies significantly between different initiating stimuli within the same vascular bed as well as between different vascular beds following the same stimulus. The differences have stimulated proposals of different mechanisms to account for the experimentally observed...... variation. Using a computational approach that allows for introduction of structural and electrophysiological heterogeneity, we systematically tested variations in both arteriolar electrophysiology and modes of stimuli. Within the same vessel, our simulations show that conduction efficacy is influenced...

  3. Methods for the Design of Vasomotor Symptom Trials: The MsFLASH Network

    Science.gov (United States)

    Newton, Katherine M.; Carpenter, Janet S.; Guthrie, Katherine A.; Anderson, Garnet L.; Caan, Bette; Cohen, Lee S.; Ensrud, Kristine E.; Freeman, Ellen W.; Joffe, Hadine; Sternfeld, Barbara; Reed, Susan D.; Sherman, Sheryl; Sammel, Mary D.; Kroenke, Kurt; Larson, Joseph C.; LaCroix, Andrea Z.

    2013-01-01

    Objective This report describes the "Menopausal Strategies: Finding Lasting Answers to Symptoms and Health” (MsFLASH) network and methodological issues addressed in designing and implementing vasomotor symptom trials. Methods Established in response to a National Institute of Health request for applications, the network was charged with conducting rapid throughput randomized trials of novel and understudied available interventions postulated to alleviate vasomotor and other menopausal symptoms. Included are descriptions of and rationale for criteria used for interventions and study selection, common eligibility and exclusion criteria, common primary and secondary outcome measures, consideration of placebo response, establishment of a biorepository, trial duration, screening and recruitment, statistical methods, and quality control. All trial designs are presented including: 1) a randomized, double-blind, placebo-controlled clinical trial designed to evaluate effectiveness of the selective serotonin reuptake inhibitor escitalopram in reducing vasomotor symptom frequency and severity; 2) a 2×3 factorial design trial to test three different interventions (yoga, exercise, and omega-3 supplementation) for improvement of vasomotor symptom frequency and bother; and 3) a three-arm comparative efficacy trial of the serotonin-norepinephrine reuptake inhibitor venlafaxine and low-dose oral estradiol versus placebo for reducing vasomotor symptom frequency compared to placebo. The network’s structure and governance are also discussed. Conclusions The methods used and lessons learned in the MsFLASH trials are shared to encourage and support the conduct of similar trials and encourage collaborations with other researchers. PMID:23760428

  4. Effect of engineered nanoparticles on vasomotor responses in rat intrapulmonary artery

    International Nuclear Information System (INIS)

    Courtois, Arnaud; Andujar, Pascal; Ladeiro, Yannick; Ducret, Thomas; Rogerieux, Francoise; Lacroix, Ghislaine; Baudrimont, Isabelle; Guibert, Christelle; Roux, Etienne; Canal-Raffin, Mireille; Brochard, Patrick; Marano, Francelyne; Marthan, Roger; Muller, Bernard

    2010-01-01

    Pulmonary circulation could be one of the primary vascular targets of finest particles that can deeply penetrate into the lungs after inhalation. We investigated the effects of engineered nanoparticles on vasomotor responses of small intrapulmonary arteries using isometric tension measurements. Acute in vitro exposure to carbon nanoparticles (CNP) decreased, and in some case abolished, the vasomotor responses induced by several vasoactive agents, whereas acute exposure to titanium dioxide nanoparticles (TiO 2 NP) did not. This could be attributed to a decrease in the activity of those vasoactive agents (including PGF 2α , serotonin, endothelin-1 and acetylcholine), as suggested when they were exposed to CNP before being applied to arteries. Also, CNP decreased the contraction induced by 30 mM KCl, without decreasing its activity. After endoplasmic reticulum calcium stores depletion (by caffeine and thapsigargin), CaCl 2 addition induced a contraction, dependent on Store-Operated Calcium Channels that was not modified by acute CNP exposure. Further addition of 30 mM KCl elicited a contraction, originating from activation of Voltage-Operated Calcium Channels that was diminished by CNP. Contractile responses to PGF 2α or KCl, and relaxation to acetylcholine were modified neither in pulmonary arteries exposed in vitro for prolonged time to CNP or TiO 2 NP, nor in those removed from rats intratracheally instilled with CNP or TiO 2 NP. In conclusion, prolonged in vitro or in vivo exposure to CNP or TiO 2 NP does not affect vasomotor responses of pulmonary arteries. However, acute exposure to CNP decreases contraction mediated by activation of Voltage-Operated, but not Store-Operated, Calcium Channels. Moreover, interaction of some vasoactive agents with CNP decreases their biological activity that might lead to misinterpretation of experimental data.

  5. Peptidergic and non-peptidergic innervation and vasomotor responses of human lenticulostriate and posterior cerebral arteries

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Gulbenkian, Sergio; Engel, Ulla

    2004-01-01

    ) between the two vessels. However, the general pattern indicates stronger vasomotor responses (Emax and Imax) in the PCA branches as compared to the lenticulostriate arteries which may lend support for the clinical observation of a difference in stroke expression between the two vascular areas....

  6. Vasomotor response of the human face: laser-Doppler measurements during mild hypo- and hyperthermia.

    Science.gov (United States)

    Rasch, W; Cabanac, M

    1993-04-01

    The skin of the face is reputed not to vasoconstrict in response to cold stress because the face skin temperature remains steady during hypothermia. The purpose of the present work was to measure the vasomotor response of the human face to whole-body hypothermia, and to compare it with hyperthermia. Six male subjects were immersed in cold and in warm water to obtain the two conditions. Skin blood flow, evaporation, and skin temperature (Tsk) were recorded in three loci of the face, the forehead, the infra orbital area, and the cheek. Tympanic (Tty) and oesophageal (Toes) temperatures were also recorded during the different thermal states. Normothermic measurements served as control. Blood flow was recorded with a laser-Doppler flowmeter, evaporation measured with an evaporimeter. Face Tsk remained stable between normo-, hypo-, and hyperthermia. Facial blood flow, however, did not follow the same pattern. The facial blood flow remained at minimal vasoconstricted level when the subjects' condition was changed from normo- to hypothermia. When the condition changed from hypo- to hyperthermia a 3 to 9-fold increase in the blood flow was recorded. From these results it was concluded that a vasoconstriction seems to be the general vasomotor state in the face during normothermia.

  7. Vasomotor wave and blood pressure response to erect posture after operation for aortic coarctation.

    OpenAIRE

    Sehested, J; Schultze, G

    1982-01-01

    Low frequency fluctuations (five to 10/min) in blood pressure, that is vasomotor waves, were recorded in the erect position in 18 patients operated upon for an isolated aortic coarctation six to eight and a half years previously, and compared with vasomotor waves in six age matched normotensive controls with respect to frequency and amplitude. The investigation was carried out by simultaneous intra-arterial blood pressure radiotelemetry recordings from the brachial and femoral arteries in all...

  8. Vasomotor function in rat arteries after ex vivo and intragastric exposure to food-grade titanium dioxide and vegetable carbon particles

    DEFF Research Database (Denmark)

    Jensen, Ditte Marie; Christophersen, Daniel Vest; Sheykhzade, Majid

    2018-01-01

    -grade particle exposure on vasomotor function and systemic oxidative stress in an ex vivo study and intragastrically exposed rats.Methods: In an ex vivo study, aorta rings from naive Sprague-Dawley rats were exposed for 30 min to food-grade TiO2 (E171), benchmark TiO2 (Aeroxide P25), food-grade vegetable carbon...... (E153) or benchmark carbon black (Printex 90). Subsequently, the vasomotor function was assessed in wire myographs. In an in vivo study, lean Zucker rats were exposed intragastrically once a week for 10 weeks to vehicle, E171 or E153. Doses were comparable to human daily intake. Vasomotor function...... no differences between groups.Conclusion: Gastrointestinal tract exposure to E171 and E153 was associated with modest albeit statistically significant alterations in the vasocontraction and vasorelaxation responses. Direct particle exposure to aorta rings elicited a similar type of response. The vasomotor...

  9. Cryosurgery in vasomotor rhinopathy: experimental histopathology.

    Science.gov (United States)

    Kellerhals, B; Schlageter, J S

    1976-01-01

    Experimental cryosurgery of the nasal mucosa in normal guinea pigss and in animals with drug-induced vasomotor rhinopathy showed complete closure of the initial ulceration by a temporary atypical epithelium within 2 week. 3-4 weeks after cryotreatment, normal ciliated epithelium covered the whole area. Within 4-5 weeks, the last signs of inflammatory reaction dinappeared. The treatment resulted in a definitive reduction of mucosal thickness, and in a numerically significant loss of vessels and glandular acini. The hintopathological results thus agreed with the clinical objective of the treatment in vasomotor rhinopathy (reduction of the nasal resistance and diminution of rhinorrhea).

  10. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice

    DEFF Research Database (Denmark)

    Chennupati, Ramesh; Meens, Merlijn J P M T; Marion, Vincent

    2014-01-01

    AIM: Argininosuccinate synthetase (ASS) is essential for recycling L-citrulline, the by-product of NO synthase (NOS), to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice. METHODS...... of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting...... responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar...

  11. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice.

    Directory of Open Access Journals (Sweden)

    Ramesh Chennupati

    Full Text Available Argininosuccinate synthetase (ASS is essential for recycling L-citrulline, the by-product of NO synthase (NOS, to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice.Endothelium-selective Ass-deficient mice (Assfl/fl/Tie2Cretg/- = Ass-KOTie2 were generated by crossing Assfl/fl mice ( = control with Tie2Cre mice. Gene ablation in endothelial cells was confirmed by immunohistochemistry. Blood pressure (MAP was recorded in 34-week-old male mice. Vasomotor responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar in control and Ass-KOTie2 mice. Depletion of circulating L-arginine by arginase 1 infusion or inhibition of NOS activity with L-NAME resulted in an increased MAP (10 and 30 mmHg, respectively in control and Ass-KOTie2 mice. Optimal arterial diameter, contractile responses to phenylephrine, and relaxing responses to acetylcholine and sodium nitroprusside were similar in healthy control and Ass-KOTie2 mice. However, in diabetic Ass-KOTie2 mice, relaxation responses to acetylcholine and endothelium-derived NO (EDNO were significantly reduced when compared to diabetic control mice.Absence of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting endothelial function in diabetes.

  12. Pooled Analysis of Six Pharmacologic and Nonpharmacologic Interventions for Vasomotor Symptoms

    Science.gov (United States)

    Guthrie, Katherine A.; LaCroix, Andrea Z.; Ensrud, Kristine E.; Joffe, Hadine; Newton, Katherine M.; Reed, Susan D.; Caan, Bette; Carpenter, Janet S.; Cohen, Lee S.; Freeman, Ellen W.; Larson, Joseph C.; Manson, JoAnn E.; Rexrode, Kathy; Skaar, Todd C.; Sternfeld, Barbara; Anderson, Garnet L.

    2015-01-01

    Objective To describe the effects of six interventions for menopausal vasomotor symptoms relative to control in a pooled analysis, facilitating translation of the results for clinicians and symptomatic women. The MsFLASH (Menopause Strategies: Finding Lasting Answers for Symptoms and Health) network tested these interventions in three randomized clinical trials (RCTs). Methods An analysis of pooled individual-level data from three RCTs is presented. Participants were 899 peri- and postmenopausal women with at least 14 bothersome vasomotor symptoms/week. Interventions included escitalopram 10–20 mg/day, non-aerobic yoga, aerobic exercise, 1.8 g/day omega-3 fatty acid supplementation, low-dose oral 17-beta-estradiol 0.5-mg/day, and low-dose venlafaxine XR 75-mg/day. The main outcome measures were changes from baseline in mean daily vasomotor symptoms frequency and bother during 8–12 weeks of treatment. Linear regression models estimated differences in outcomes between each intervention and corresponding control group, adjusted for baseline characteristics. Models included trial-specific intercepts, effects of the baseline outcome measure, and time. Results The 8-week reduction in vasomotor symptoms frequency from baseline relative to placebo was similar for escitalopram at −1.4/day (95% CI: −2.7 to −0.2), low-dose estradiol at −2.4 (95% CI: −3.4 to −1.3), and venlafaxine at −1.8 (95% CI: −2.8 to −0.8); vasomotor symptoms bother reduction was minimal and did not vary across these three pharmacologic interventions (means −0.2 to −0.3 relative to placebo). No effects on vasomotor symptoms frequency or bother were seen with aerobic exercise, yoga or omega-3 supplements. Conclusions These analyses suggest that escitalopram, low-dose estradiol, and venlafaxine provide comparable, modest reductions in vasomotor symptoms frequency and bother among women with moderate hot flushes. Clinical Trial Registration ClinicalTrials.gov, www

  13. Vasomotor Regulation of Coronary Microcirculation by Oxidative Stress: Role of Arginase

    Directory of Open Access Journals (Sweden)

    Lih eKuo

    2013-08-01

    Full Text Available Overproduction of reactive oxygen species, i.e., oxidative stress, is associated with the activation of redox signaling pathways linking to inflammatory insults and cardiovascular diseases by impairing endothelial function and consequently blood flow dysregulation due to microvascular dysfunction. This review focuses on the regulation of vasomotor function in the coronary microcirculation by endothelial nitric oxide (NO during oxidative stress and inflammation related to the activation of L-arginine consuming enzyme arginase. Superoxide produced in the vascular wall compromises vasomotor function by not only scavenging endothelium-derived NO but also inhibiting prostacyclin synthesis due to formation of peroxynitrite. The upregulation of arginase contributes to the deficiency of endothelial NO and microvascular dysfunction in various vascular diseases by initiating or following oxidative stress and inflammation. Hydrogen peroxide, a diffusible and stable oxidizing agent, exerts vasodilator function and plays important roles in the physiological regulation of coronary blood flow. In occlusive coronary ischemia, the release of hydrogen peroxide from the microvasculature helps to restore vasomotor function of coronary collateral microvessels with exercise training. However, excessive production and prolonged exposure of microvessels to hydrogen peroxide impairs NO-mediated endothelial function by reducing L-arginine availability through hydroxyl radical-dependent upregulation of arginase. The redox signaling can be a double-edged sword in the microcirculation, which helps tissue survival in one way by improving vasomotor regulation and elicits oxidative stress and tissue injury in the other way by causing vascular dysfunction. The impact of vascular arginase on the development of vasomotor dysfunction associated with angiotensin II receptor activation, hypertension, ischemia-reperfusion, hypercholesterolemia and inflammatory insults is discussed.

  14. Vegans report less bothersome vasomotor and physical menopausal symptoms than omnivores.

    Science.gov (United States)

    Beezhold, Bonnie; Radnitz, Cynthia; McGrath, Robert E; Feldman, Arielle

    2018-06-01

    Lifestyle modifications that may reduce menopausal symptoms have generated much interest. The vegetarian diet has been associated with a lower risk of chronic disease as well as a more healthy hormonal milieu. Our objective in this cross-sectional study was to survey peri- and postmenopausal women to investigate menopausal symptoms and dietary pattern. Survey distribution in 2015-2016 was aimed at female vegans, vegetarians, and omnivores between the ages of 45 and 80 years, who were active on senior and vegetarian social networking websites and at vegan restaurants and events. We investigated vasomotor and physical symptoms as measured by the Menopause-specific Quality of Life Questionnaire (MENQOL) and dietary pattern classified by animal protein intakes reported in response to food frequency questions. Out of 754 participants who completed the survey, 604 reported they were perimenopausal (n = 121) or postmenopausal (n = 483), of whom 539 also completed the food frequency questions. We compared vasomotor and physical symptoms in omnivores (n = 304, consumed meat and/or poultry at least monthly) and vegans (n = 125, abstained from all animal proteins) using general linear models; covariates included age, exercise, hormone replacement therapy, presence of reproductive organs, and age at menopause. Among perimenopausal women, vegans reported less bothersome vasomotor (p < 0.01) and physical symptoms (p < 0.01) than omnivores. For both symptom types, more vegetables and less flesh food were associated with less bothersome symptoms (p values < 0.05). Eating a plant-based diet may be helpful for women in menopausal transition who prefer a natural means to manage their symptoms. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. The effect of foot reflexology applied to women aged between 40 and 60 on vasomotor complaints and quality of life.

    Science.gov (United States)

    Gozuyesil, Ebru; Baser, Muruvvet

    2016-08-01

    This study aims to identify the effects of foot reflexology applied to women on their vasomotor complaints and quality of life. A randomised controlled study was conducted with 120 women. The experimental group received foot reflexology treatment, while the control group received nonspecific foot massage. The mean scores for hot flashes, sweats, and night sweats, were lower in the reflexology group than the control group after the practice; and the difference between the groups was statistically significant (p reflexology group (p  0.05). Results showed that reflexology might be effective in decreasing vasomotor problems and increasing quality of life in women in the menopausal period. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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

  17. Psychosocial and socioeconomic burden of vasomotor symptoms in menopause: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Utian Wulf H

    2005-08-01

    Full Text Available Abstract Many women experience vasomotor symptoms at or around the time of menopause. Hot flushes and night sweats are considered primary menopausal symptoms that may also be associated with sleep and mood disturbances, as well as decreased cognitive function. All of these symptoms may lead to social impairment and work-related difficulties that significantly decrease overall quality of life. Hot flushes have shown a great deal of variability in their frequency and severity in women. In some women, hot flushes persist for several months; in others, they may last for more than 10 years. Traditionally vasomotor symptoms were reported to begin 5 to 10 years prior to the cessation of the final menstrual cycle, corresponding with the initial decline in circulating gonadal hormones; however, night sweats in particular most often begin in perimenopause. The pathogenesis of hot flushes has not yet been fully elucidated, but the circuitry involving estrogen and neurotransmitters, norepinephrine and serotonin specifically, are hypothesized to play a major role in the altered homeostatic thermoregulatory mechanisms underlying these events. Menopause-associated vasomotor symptoms are associated with significant direct and indirect costs. Overall costs of traditional pharmacotherapy or complementary and alternative medicine modalities, including over-the-counter treatments and dietary supplements, for managing menopause-related vasomotor symptoms are substantial and include initial and follow-up physician visits and telephone calls. Additional costs include laboratory testing, management of adverse events, loss of productivity at work, and personal and miscellaneous costs. Pharmacoeconomic analyses, including those that consider risks identified by the Women's Health Initiative, generally support the cost-effectiveness of hormonal therapy for menopause-associated vasomotor symptoms, which have been the mainstay for the management of these symptoms for more

  18. Cerebral vasomotor reactivity: steady-state versus transient changes in carbon dioxide tension.

    Science.gov (United States)

    Brothers, R Matthew; Lucas, Rebekah A I; Zhu, Yong-Sheng; Crandall, Craig G; Zhang, Rong

    2014-11-01

    Cerebral vasomotor reactivity (CVMR) to changes in arterial carbon dioxide tension (P aCO 2) is assessed during steady-state or transient changes in P aCO 2. This study tested the following two hypotheses: (i) that CVMR during steady-state changes differs from that during transient changes in P aCO 2; and (ii) that CVMR during rebreathing-induced hypercapnia would be blunted when preceded by a period of hyperventilation. For each hypothesis, end-tidal carbon dioxide tension (P ET , CO 2) middle cerebral artery blood velocity (CBFV), cerebrovascular conductance index (CVCI; CBFV/mean arterial pressure) and CVMR (slope of the linear regression between changes in CBFV and CVCI versus P ET , CO 2) were assessed in eight individuals. To address the first hypothesis, measurements were made during the following two conditions (randomized): (i) steady-state increases in P ET , CO 2 of 5 and 10 Torr above baseline; and (ii) rebreathing-induced transient breath-by-breath increases in P ET , CO 2. The linear regression for CBFV versus P ET , CO 2 (P = 0.65) and CVCI versus P ET , CO 2 (P = 0.44) was similar between methods; however, individual variability in CBFV or CVCI responses existed among subjects. To address the second hypothesis, the same measurements were made during the following two conditions (randomized): (i) immediately following a brief period of hypocapnia induced by hyperventilation for 1 min followed by rebreathing; and (ii) during rebreathing only. The slope of the linear regression for CBFV versus P ET , CO 2 (P < 0.01) and CVCI versus P ET , CO 2 (P < 0.01) was reduced during hyperventilation plus rebreathing relative to rebreathing only. These results indicate that cerebral vasomotor reactivity to changes in P aCO 2 is similar regardless of the employed methodology to induce changes in P aCO 2 and that hyperventilation-induced hypocapnia attenuates the cerebral vasodilatory responses during a subsequent period of rebreathing

  19. Randomized Controlled Trial of Low-Dose Estradiol and the SNRI Venlafaxine for Vasomotor Symptoms

    Science.gov (United States)

    Joffe, Hadine; Guthrie, Katherine A.; LaCroix, Andrea Z.; Reed, Susan D.; Ensrud, Kristine E.; Manson, JoAnn E.; Newton, Katherine M.; Freeman, Ellen W.; Anderson, Garnet L.; Larson, Joseph C.; Hunt, Julie; Shifren, Jan; Rexrode, Kathryn M.; Caan, Bette; Sternfeld, Barbara; Carpenter, Janet S.; Cohen, Lee

    2014-01-01

    Importance Estrogen therapy is the gold standard treatment for hot flashes and night sweats, but some women are unable or unwilling to use it because of associated risks. The serotonin-norepinephrine reuptake inhibitor venlafaxine is used widely as a non-hormonal treatment. While clinical impression is that serotonin-norepinephrine reuptake inhibitors are less effective than estrogen, these medications have not been simultaneously evaluated in one clinical trial. Objective To determine the efficacy and tolerability of low-dose oral 17-beta-estradiol and low-dose venlafaxine XR in alleviating vasomotor symptoms. Design and Participants 339 peri- and postmenopausal women with ≥2 bothersome vasomotor symptoms per day (mean 8.1, SD 5.3/day) were recruited from the community to MsFLASH (Menopause Strategies: Finding Lasting Answers for Symptoms and Health) clinical network sites November 2011—October 2012. Interventions Participants were randomized to double-blinded treatment with low-dose oral 17-beta-estradiol 0.5-mg/day (n=97), low-dose venlafaxine XR 75-mg/day (n=96), or placebo (n=146) for 8 weeks. Main Outcomes Primary outcome was the mean daily frequency of vasomotor symptoms after 8 weeks of treatment. Secondary outcomes were vasomotor symptom severity, bother and interference. Intent-to-treat analyses compared change in vasomotor symptom frequency between each active intervention and placebo and between the two active treatments. Results Compared to baseline, mean vasomotor symptom frequency at week 8 decreased by 53% with estradiol, 48% with venlafaxine, and 29% with placebo. Estradiol reduced the frequency of symptoms by 2.3 (95% CI 1.3–3.4) more per day than placebo (p<0.001), and venlafaxine by 1.8 (95% CI 0.8–2.7) more per day than placebo (p=0.005). Results were consistent for VMS severity, bother and interference. Low-dose estradiol reduced symptom frequency by 0.6 more per day than venlafaxine (95% CI, 1.8 more per day to 0.6 fewer per day than

  20. Internephron coupling by conducted vasomotor responses in normotensive and spontaneously hypertensive rats

    DEFF Research Database (Denmark)

    Wagner, A J; Holstein-Rathlou, N H; Marsh, D J

    1997-01-01

    strains. Mechanical length constants were similar in SD and SHR (approximately 325 microm), indicating that the signal responsible for the effect decays at the same rate in both strains. We conclude that internephron coupling strength is significantly greater in SHR and that internephron coupling is due...

  1. Short-Term Isoflavone Intervention in the Treatment of Severe Vasomotor Symptoms after Surgical Menopause: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Supanimit Teekachunhatean

    2015-01-01

    Full Text Available Isoflavones are soy phytoestrogens that potentially exert various favorable effects in postmenopausal women, for example, alleviating vasomotor episodes, attenuating bone loss, and stimulating vaginal epithelial maturation. There has, however, been lack of consensus regarding those therapeutic effects. Most clinical studies of isoflavones have been conducted with women who had undergone natural menopause, but not those who had undergone surgical menopause. This study reports on a 51-year-old woman who presented with severe vasomotor episodes after undergoing a hysterectomy and a bilateral oophorectomy due to hypermenorrhea secondary to myoma uteri. She refused hormone therapy due to fear of adverse drug reactions so was treated with oral soy isoflavones (two capsules twice daily, equivalent to at least 100 mg daily dose for 8 weeks. The number and severity of hot flushes and her menopause-specific quality of life dramatically improved from baseline values. The serum bone resorption marker (beta C-telopeptide decreased markedly, while vaginal epithelial maturation improved slightly, suggesting the potential of isoflavones in attenuating bone loss and stimulating vaginal maturation. The intervention did not adversely affect the hormonal profile (FSH, LH, and estradiol and liver or renal functions. Thus, isoflavones could be an option for women experiencing severe vasomotor episodes after surgical menopause.

  2. Mind-body interventions for vasomotor symptoms in healthy menopausal women and breast cancer survivors. A systematic review.

    Science.gov (United States)

    Stefanopoulou, Evgenia; Grunfeld, Elizabeth Alice

    2017-09-01

    Mind-body therapies are commonly recommended to treat vasomotor symptoms, such as hot flushes and night sweats (HFNS). The purpose of this systematic review was to evaluate the available evidence to date for the efficacy of different mind-body therapies to alleviate HFNS in healthy menopausal women and breast cancer survivors. Randomized controlled trials (RCTs) were identified using seven electronic search engines, direct searches of specific journals and backwards searches through reference lists of related publications. Outcome measures included HFNS frequency and/or severity or self-reported problem rating at post-treatment. The methodological quality of all studies was systematically assessed using predefined criteria. Twenty-six RCTs met the inclusion criteria. Interventions included yoga (n = 5), hypnosis (n = 3), mindfulness (n = 2), relaxation (n = 7), paced breathing (n = 4), reflexology (n = 1) and cognitive behavioural therapy (CBT) (n = 4). Findings were consistent for the effectiveness of CBT and relaxation therapies for alleviating troublesome vasomotor symptoms. For the remaining interventions, although some trials indicated beneficial effects (within groups) at post-treatment and/or follow up, between group findings were mixed and overall, methodological differences across studies failed to provide convincing supporting evidence. Collectively, findings suggest that interventions that include breathing and relaxation techniques, as well as CBT, can be beneficial for alleviating vasomotor symptoms. Additional large, methodologically rigorous trials are needed to establish the efficacy of interventions on vasomotor symptoms, examine long-term outcomes and understand how they work.

  3. Sudomotor and vasomotor activity during the menstrual cycle with global heating.

    Science.gov (United States)

    Petrofsky, Jerrold; Lee, Haneul; Khowailed, Iman Akef

    2017-07-01

    Many studies have reported that there are changes in sympathetic activity throughout the menstrual cycle as there are oestrogen receptor in the hypothalamus and all other parts of the sympathetic nervous system. The purpose of this study was to see whether there were variations in sympathetic activity, skin vasomotor and sweat gland sudomotor rhythms during the menstrual cycle. Eight young female subjects with a regular menstrual cycle participated in the study. Subjects were tested once during the follicular phase and once during the luteal phase. Skin blood flow and sweat rate were significantly higher in the luteal phase compared with the follicular phase (p < .05), but the frequency and magnitude of sudomotor and vasomotor rhythms were significantly greater in the follicular phase (p < .05). In contrast, spectral data showed less sympathetic activity in the luteal phase. A significant finding here is that the sudomotor rhythm of sweat glands is altered by the menstrual cycle. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  4. Pulsed Wave Doppler Ultrasound Is Useful to Assess Vasomotor Response in Patients with Multiple System Atrophy and Well Correlated with Tilt Table Study

    Directory of Open Access Journals (Sweden)

    Ke-Vin Chang

    2012-01-01

    Full Text Available The study aim was to assess sympathetic vasomotor response (SVR by using pulsed wave Doppler (PWD ultrasound in patients with multiple system atrophy (MSA and correlate with the tilt table study. We recruited 18 male patients and 10 healthy men as controls. The SVR of the radial artery was evaluated by PWD, using inspiratory cough as a provocative maneuver. The response to head-up tilt was studied by a tilt table with simultaneous heart rate and blood pressure recording. The hemodynamic variables were compared between groups, and were examined by correlation analysis. Regarding SVR, MSA patients exhibited a prolonged latency and less heart rate acceleration following inspiratory cough. Compared with the tilt table test, the elevation of heart rate upon SVR was positively correlated to the increase of heart rate after head-up tilt. The correlation analysis indicated that the magnitude of blood pressure drop from supine to upright was positively associated with the SVR latency but negatively correlated with the heart rate changes upon SVR. The present study demonstrated that blunted heart rate response might explain MSA's vulnerability to postural challenge. PWD may be used to predict cardiovascular response to orthostatic stress upon head-up tilt in MSA patients.

  5. Control of sympathetic vasomotor tone by catecholaminergic C1 neurones of the rostral ventrolateral medulla oblongata

    Science.gov (United States)

    Marina, Nephtali; Abdala, Ana P.L.; Korsak, Alla; Simms, Annabel E.; Allen, Andrew M.; Paton, Julian F.R.; Gourine, Alexander V.

    2011-01-01

    Aims Increased sympathetic tone in obstructive sleep apnoea results from recurrent episodes of systemic hypoxia and hypercapnia and might be an important contributor to the development of cardiovascular disease. In this study, we re-evaluated the role of a specific population of sympathoexcitatory catecholaminergic C1 neurones of the rostral ventrolateral medulla oblongata in the control of sympathetic vasomotor tone, arterial blood pressure, and hypercapnia-evoked sympathetic and cardiovascular responses. Methods and results In anaesthetized rats in vivo and perfused rat working heart brainstem preparations in situ, C1 neurones were acutely silenced by application of the insect peptide allatostatin following cell-specific targeting with a lentiviral vector to express the inhibitory Drosophila allatostatin receptor. In anaesthetized rats with denervated peripheral chemoreceptors, acute inhibition of 50% of the C1 neuronal population resulted in ∼50% reduction in renal sympathetic nerve activity and a profound fall in arterial blood pressure (by ∼25 mmHg). However, under these conditions systemic hypercapnia still evoked vigorous sympathetic activation and the slopes of the CO2-evoked sympathoexcitatory and cardiovascular responses were not affected by inhibition of C1 neurones. Inhibition of C1 neurones in situ resulted in a reversible fall in perfusion pressure and the amplitude of respiratory-related bursts of thoracic sympathetic nerve activity. Conclusion These data confirm a fundamental physiological role of medullary catecholaminergic C1 neurones in maintaining resting sympathetic vasomotor tone and arterial blood pressure. However, C1 neurones do not appear to mediate sympathoexcitation evoked by central actions of CO2. PMID:21543384

  6. Sex-Related Differences in Vasomotor Function in Patients With Angina and Unobstructed Coronary Arteries

    DEFF Research Database (Denmark)

    Aziz, Ahmed; Hansen, Henrik Steen; Sechtem, Udo

    2017-01-01

    BACKGROUND Coronary vasomotor dysfunction is an important mechanism for angina in patients with unobstructed coronary arteries. OBJECTIVES The purpose of this study was to determine sex differences in the prevalence and clinical presentation of vasomotor dysfunction in a European population...... and to examine sex differences in the dose of acetylcholine leading to a positive acetylcholine provocation test (ACH test). METHODS Between 2007 and 2014, we included 1,379 consecutive patients with stable angina, unobstructed coronaries and ACH test performed for epicardial vasospasm or coronary microvascular...... dysfunction (CMD) due to microvascular spasm. The predictive value of sex, risk factors, symptoms, and noninvasive test results was analyzed by means of logistic regression. RESULTS The mean patient age was 62 years, and 42% were male. There were 813 patients (59 with a pathological ACH test, 33% for CMD...

  7. Hazard identification of particulate matter on vasomotor dysfunction and progression of atherosclerosis

    DEFF Research Database (Denmark)

    Møller, Peter; Mikkelsen, Lone; Vesterdal, Lise Kristine

    2011-01-01

    and inflammatory pathways. We have assessed the effect of exposure to particulate matter on progression of atherosclerosis and vasomotor function in humans, animals, and ex vivo experimental systems. The type of particles that have been tested in these systems encompass TiO(2), carbon black, fullerene C(60...... of particulate matter....

  8. Beneficio del ejercicio aeróbico sobre los síntomas vasomotores de pacientes postmenopáusicas..

    OpenAIRE

    Paredes Pérez, Napoleón; Universidad de San Martín de Porres

    2013-01-01

    OBJETIVOAnalizar el beneficio del ejercicio aeróbico sobre los síntomas vasomotores de las pacientes postmenopáusicas..MATERIAL Y MÉTODOEstudio prospectivo, cuasi experimental, comparativo del antes y el después de ejercicio aeróbico en postmenopáusicas con síntomas vasomotores que acudieron para tratamiento no hormonal. Fueron ingresando desde el 2 de enero del 2012 y todas tuvieron seguimiento hasta el 30 de junio del 2012. Todas realizaron una rutina de ejercicio con evaluación basal, a los...

  9. Treating the root cause: acupuncture for the treatment of migraine, menopausal vasomotor symptoms, and chronic insomnia.

    Science.gov (United States)

    Hammes, Amber E; Wahner-Roedler, Dietlind L; Bauer, Brent A

    2014-01-01

    This case report describes the effectiveness of a single intervention, acupuncture, for relieving or abolishing severe migraines, menopausal vasomotor symptoms, and chronic insomnia and, thus, markedly improving quality of life. A 49-year-old woman was referred for acupuncture treatment of her daily migraines, menopausal vasomotor symptoms, and chronic insomnia. The patient had received polypharmacy treatment for these conditions for several years but had rather limited relief of her symptoms. The patient received 10 weekly or biweekly acupuncture treatments over three months. Her migraines reduced in frequency and intensity after her first acupuncture treatment, and she was able to discontinue use of her migraine medications after her eighth treatment. Subsequently, her menopausal vasomotor symptoms and chronic insomnia resolved. This case illustrates successful treatment of the symptoms of three medical conditions with a single complementary, alternative, and integrative medicine procedure, namely, acupuncture, one of the key elements of traditional Chinese medicine. The patient's medical problems had been treated for years with a multitude of medications, which led to adverse effects and little symptomatic improvement. Providers of complementary, alternative, and integrative medicine and providers practicing allopathic medicine should seek treatment options for their patients that promise to be helpful for various symptoms or diseases, that is, treating the root cause rather than using polypharmacy for various symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. A Pilot Randomized, Single Blind, Placebo-Controlled Trial of Traditional Acupuncture for Vasomotor Symptoms and Mechanistic Pathways of Menopause

    Science.gov (United States)

    Painovich, Jeannette M.; Shufelt, Chrisandra L.; Azziz, Ricardo; Yang, Yuching; Goodarzi, Mark O.; Braunstein, Glenn D.; Karlan, Beth Y.; Stewart, Paul M.; Merz, C. Noel Bairey

    2011-01-01

    Objective To conduct a pilot study for feasibility of planning a definitive clinical trial comparing traditional acupuncture (TA) to sham acupuncture (SA) and waiting control (WC) on menopause related vasomotor symptoms (VMS), quality of life (QOL), and the hypothalamic-pituitary-adrenal (HPA) axis in peri and post-menopausal women. Methods Thirty-three peri and post-menopausal women with at least 7 VMS daily were randomized to TA, SA or WC. The TA and SA groups were given three treatments per week for 12 weeks. Outcomes included the number and severity of VMS, MENQOL questionnaire, Beck Depression Inventory, Spielberg State-Trait Anxiety Instrument, Pittsburgh Quality Sleep Index, 24 hour urine cortisol and metabolites, and ACTH stimulation testing. Results Both TA and SA groups demonstrated improved VMS trends compared to WC (Δ −3.5±3.00 vs. −4.1±3.79 vs. −1.2±2.4, respectively, p=.20), and significantly improved MENQOL vasomotor scores (Δ − 1.5±2.02 vs. −1.8±1.52 vs. 0.3±0.64, respectively, p=.04). There were no psychosocial group differences. Exit 24-hour urinary measures were lower in the TA vs the SA or WC in total cortisol metabolites (4,658.9±1,670.9 vs 7,735.8±3,747.9 vs 5,166.0±2,234.5, p=0.03, respectively) and DHEA (41.4±27.46, 161.2±222.77, 252.4±385.40, respectively, p=0.05). The ACTH stimulation cortisol response data also trended in the hypothesized direction (p=0.17). Conclusion Both TA and SA reduce VMS frequency and severity and improve VMS-related quality of life compared to WC; however, TA alone may impact the HPA axis. This association is viewed as preliminary and hypothesis-generating and should be explored in a large clinical trial. PMID:21968279

  11. Análisis del beneficio del ejercicio aeróbico sobre los síntomas vasomotores en pacientes postmenopáusicas

    OpenAIRE

    Paredes Pérez, Noé Napoleón

    2013-01-01

    Objetivo: Analizar el beneficio del ejercicio aeróbico sobre los síntomas vasomotores de las pacientes postmenopáusicas. Material y Método: Estudio prospectivo, cuasi experimental, comparativo del antes y el después de ejercicio aeróbico en postmenopáusicas con síntomas vasomotores que acudieron para tratamiento no hormonal. Fueron ingresando desde el 2 de enero del 2012 y todas tuvieron seguimiento hasta el 30 de junio del 2012. Todas realizaron una rutina de ejercicio con evaluación bas...

  12. Modest vasomotor dysfunction induced by low doses of C60 fullerenes in apolipoprotein E knockout mice with different degree of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Loft Steffen

    2009-02-01

    Full Text Available Abstract Background Exposure to small size particulate matter in urban air is regarded as a risk factor for cardiovascular effects, whereas there is little information about the impact on the cardiovascular system by exposure to pure carbonaceous materials in the nano-size range. C60 fullerenes are nano-sized particles that are expected to have a widespread use, including cosmetics and medicines. Methods We investigated the association between intraperitoneal injection of pristine C60 fullerenes and vasomotor dysfunction in the aorta of 11–13 and 40–42 weeks old apolipoprotein E knockout mice (apoE-/- with different degree of atherosclerosis. Results The aged apoE-/-mice had lower endothelium-dependent vasorelaxation elicited by acetylcholine in aorta segments mounted in myographs and the phenylephrine-dependent vasoconstriction response was increased. One hour after an intraperitoneal injection of 0.05 or 0.5 mg/kg of C60 fullerenes, the young apoE-/- mice had slightly reduced maximal endothelium-dependent vasorelaxation. A similar tendency was observed in the old apoE-/- mice. Hampered endothelium-independent vasorelaxation was also observed as slightly increased EC50 of sodium nitroprusside-induced vasorelaxation response in young apoE-/- mice. Conclusion Treatment with C60 fullerenes affected mainly the response to vasorelaxation in young apoE-/- mice, whereas the vasomotor dysfunction in old apoE-/- mice with more advanced atherosclerosis was less affected by acute C60 fullerene treatment. These findings represent an important step in the hazard characterization of C60 fullerenes by showing that intraperitoneal administration is associated with a moderate decrease in the vascular function of mice with atherosclerosis.

  13. The role of transdermal estrogen sprays and estradiol topical emulsion in the management of menopause-associated vasomotor symptoms

    Directory of Open Access Journals (Sweden)

    Amy M Egras

    2010-05-01

    Full Text Available Amy M Egras, Elena M UmlandJefferson School of Pharmacy, Thomas Jefferson University, Philadelphia, PA, USAAbstract: Vasomotor symptoms (VMS are among the most bothersome complaints of postmenopausal women. To date, the most widely studied and effective treatment for VMS is hormone replacement therapy, consisting of estrogen (in women without a uterus or estrogen plus progestin (in women with a uterus. Traditionally, oral estrogens have been used for treatment. However, over the years, additional estrogen formulations have been developed including transdermal patches; vaginal rings, creams, and tablets; and injectable preparations. Two newer formulations are transdermal estrogen spray and estradiol topical emulsion. This review evaluates the current literature assessing the use of these two newer formulations for the treatment of VMS associated with menopause.Keywords: menopause, vasomotor symptoms, transdermal estrogen spray, estradiol topical emulsion

  14. Relationship between 31P nuclear magnetic resonance spectra and pulmonary vasomotor tone in hypoxic pig lobes

    International Nuclear Information System (INIS)

    Buescher, P.; Pillain, R.; Pearse, D.; Eichhorn, G.; Sylvester, J.

    1986-01-01

    To investigate the relationship between lung tissue energy state and vasomotor tone, the authors measured 31 P NMR spectra during repeated exposures to hypoxia in 5 isolated degassed left lower lobes perfused with blood at a constant flow (500ml/min) and left atrial pressure ( 2 tension (PpO 2 ) was changed by varying the gas mixtures (40, 7, 0% O 2 ) flowing through a bubble oxygenator in the perfusion circuit. 31 P spectra obtained after stabilization of pulmonary artery pressure (Ppa) at each PpO 2 revealed peaks for ATP, inorganic phosphate (Pi) phosphomono and diesters (PME and PDE). During 7% O 2 , Ppa and ATP increased but Pi did not change suggesting that lung tissue energy state improved during hypoxic vasoconstriction. During 0% O 2 , there was a reversible deterioration of energy state (high Pi, low ATP). Thus, it appears that lung tissue energy state and vasomotor tone were related, but the precise nature of the relationship remains to be determined

  15. Weather/temperature-sensitive vasomotor rhinitis may be refractory to intranasal corticosteroid treatment.

    Science.gov (United States)

    Jacobs, Robert; Lieberman, Philip; Kent, Edward; Silvey, MaryJane; Locantore, Nicholas; Philpot, Edward E

    2009-01-01

    Vasomotor rhinitis (VMR) is a common but poorly understood disorder of which there are two major subgroups: VMR(w/t), triggered by weather/temperature and VMR(ir), triggered by airborne irritants. No specific biological pathways or specific treatments for VMR(w/t) or VMR(ir) have been identified. However, intranasal corticosteroids (INSs) are effective in treating many forms of nonallergic rhinitis that include these conditions. A recently introduced INS with established efficacy in allergic rhinitis and enhanced affinity, fluticasone furoate, may possess the potency and safety profile required to treat chronic VMR(w/t). Two replicate studies (FFR30006 and FFR30007) were conducted in six countries to evaluate the efficacy and safety of fluticasone furoate nasal spray in subjects with VMR(w/t). After a 7- to 14-day screening period, subjects (n = 699) with symptomatic VMR(w/t) received fluticasone furoate, 110 mug q.d. or placebo for 4 weeks in these two randomized, double-blind, parallel-group studies. Subjects rated their nasal symptoms (congestion, rhinorrhea, and postnasal drip) twice daily on a 4-point categorical scale and evaluated their overall response to treatment at study end. Fluticasone furoate did not significantly improve daily reflective total nasal symptom scores, the primary end point, versus placebo (p = 0.259) and there was no improvement in any other measure of efficacy. The active treatment was well tolerated. Fluticasone furoate was not effective in treating subjects with a newly defined condition, weather-sensitive VMR. These unexpected results suggest that VMR(w/t) is a distinct subgroup of VMR that is refractory to treatment with INSs. Additional study of other treatments for VMR(w/t) (including INSs) is warranted.

  16. Vasomotor and sexual symptoms in older Australian women: a cross-sectional study.

    Science.gov (United States)

    Zeleke, Berihun M; Bell, Robin J; Billah, Baki; Davis, Susan R

    2016-01-01

    To determine the prevalence and severity of vasomotor symptoms (VMS) and sexual symptoms in community-dwelling older women, and to explore factors associated with VMS. Population-based cross-sectional study. Not applicable. A total of 1,548 women aged 65-79 years. None. The presence and self-rated severity of VMS (hot flashes, night sweats, or sweating), and sexual symptoms (intimacy, desire, and vaginal dryness) were determined with the use of the Menopause Quality of Life (MenQOL) questionnaire. All items of the vasomotor and the sexual MenQOL domains were completed by 1,532 and 1,361 of the study participants, respectively. Menopausal hormone therapy (MHT) use was reported by 6.2% of the women, and 6.9% reported using vaginal estrogen. Among the 1,426 women not using MHT, at least 1 VMS was reported by 32.8%. The prevalence of VMS rated as moderately to severely bothersome was 3.4%. A total of 54.4% of currently partnered women had sexual symptoms, and 32.5% reported vaginal dryness during intercourse in the past month. In the multivariate analysis, factors significantly associated with VMS were age, obesity, being a caregiver for another person, and bilateral oophorectomy. VMS and vaginal atrophy symptoms are common in community-dwelling older women, but they are predominantly untreated. The degree of distress caused by sexual symptoms among older women needs further exploration. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  17. Skin vasomotor hemiparesis followed by overactivity: characteristic thermography findings in a patient with Horner syndrome due to spinal cord infarction.

    Science.gov (United States)

    Kobayashi, Makoto

    2016-04-01

    We present a 21-year-old female with Horner syndrome due to spinal cord infarction. In this patient, infrared thermography revealed a hemibody skin temperature increase followed by excessive focal decreases, indicating skin vasomotor hemiparesis and overactivity.

  18. Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity

    Science.gov (United States)

    Farb, Melissa G.; Tiwari, Stephanie; Karki, Shakun; Ngo, Doan TM; Carmine, Brian; Hess, Donald T.; Zuriaga, Maria A.; Walsh, Kenneth; Fetterman, Jessica L.; Hamburg, Naomi M.; Vita, Joseph A.; Apovian, Caroline M.; Gokce, Noyan

    2013-01-01

    Objective The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans. Design and Methods In 20 obese subjects (age 37±12 yrs, BMI 47±8 kg/m2) we collected subcutaneous and visceral fat during bariatric surgery and characterized adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat. Results Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (p<0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway were upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by 2-fold (p=0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with Nω-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability. Conclusions Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity. PMID:23640904

  19. Topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on nonhormonal management of vasomotor symptoms.

    Science.gov (United States)

    Carpenter, Janet S; Laine, Tei; Harrison, Blake; LePage, Meghan; Pierce, Taran; Hoteling, Nathan; Börner, Katy

    2017-10-01

    We sought to depict the topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on the nonhormonal management of menopause-associated vasomotor symptoms released on September 21, 2015, and its associated press release from September 23, 2015. Three data sources were used: online news articles, National Public Radio, and Twitter. For topical diffusion, we compared keywords and their frequencies among the position statement, press release, and online news articles. We also created a network figure depicting relationships across key content categories or nodes. For geospatial diffusion within the United States, we compared locations of the 109 National Public Radio (NPR) stations covering the statement to 775 NPR stations not covering the statement. For temporal diffusion, we normalized and segmented Twitter data into periods before and after the press release (September 12, 2015 to September 22, 2015 vs September 23, 2015 to October 3, 2015) and conducted a burst analysis to identify changes in tweets from before to after. Topical information diffused across sources was similar with the exception of the more scientific terms "vasomotor symptoms" or "vms" versus the more colloquial term "hot flashes." Online news articles indicated media coverage of the statement was mainly concentrated in the United States. NPR station data showed similar proportions of stations airing the story across the four census regions (Northeast, Midwest, south, west; P = 0.649). Release of the statement coincided with bursts in the menopause conversation on Twitter. The findings of this study may be useful for directing the development and dissemination of future North American Menopause Society position statements and/or press releases.

  20. Expression of connexin 37, 40 and 43 in rat mesenteric arterioles and resistance arteries

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Mikkelsen, Hanne B; Arensbak, Birgitte

    2003-01-01

    Connexins are the protein constituents of gap junctions which mediate intercellular communication in most tissues. In arterioles gap junctions appear to be important for conduction of vasomotor responses along the vessel. Studies of the expression pattern of connexin isoforms in the microcirculat......Connexins are the protein constituents of gap junctions which mediate intercellular communication in most tissues. In arterioles gap junctions appear to be important for conduction of vasomotor responses along the vessel. Studies of the expression pattern of connexin isoforms...... in the microcirculation are sparse. We investigated the expression of the three major vascular connexins in mesenteric arterioles (diameter micro m) from male Sprague-Dawley rats, since conducted vasomotor responses have been described in these vessels. The findings were compared with those obtained from upstream...... small resistance arteries. Indirect immunofluorescence techniques were used on whole mounts of mesenteric arterioles and on frozen sections of resistance arteries (diameter approximately 300 micro m). Mesenteric arterioles expressed Cx40 and Cx43 in the endothelial layer, and Cx37 was found in most...

  1. Menopausal vasomotor symptoms are associated with poor self-assessed work ability.

    Science.gov (United States)

    Gartoulla, Pragya; Bell, Robin J; Worsley, Roisin; Davis, Susan R

    2016-05-01

    It has been hypothesised that vasomotor symptoms (VMS), the hallmark of menopause, may affect women's workplace performance. The aim of this study was to investigate the association between VMS and self-reported work ability, taking into account socio-demographic characteristics. Study design/Main Outcome measures: A national cross-sectional survey of women, aged 40-65 years, was conducted between October 2013 and March 2014. Participants provided socio-demographic and lifestyle factors and completed the Menopause Specific Quality of Life Questionnaire (MENQOL) and the Work Ability Index (WAI). Of 2020 women who comprised the study sample, 1274 were in paid employment and 1263 completed the WAI. The WAI score was good-excellent for 81.5% of women and poor-moderate for 18.5%. After adjustment for socio-demographic characteristics, having any VMS was associated with greater likelihood of poor-moderate work ability [odds ratio (OR)=2.45, 95% CI 1.69-3.54]. Poorer work ability was significantly and independently associated with being un-partnered, obese or overweight, smoking, being carer and having insecure housing finance, but not with age. Overall, most women functioned well at work. We observed an association suggesting a relationship not only between menopausal VMS and personal wellbeing, but also between VMS and self-assessed work ability. Although 4 in 5 women functioned well at work, recognition of the association with VMS may improve wellbeing and work performance of working women at midlife. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Safety, efficacy and patient acceptability of drospirenone and estradiol in the treatment of menopausal vasomotor symptoms: a review

    Directory of Open Access Journals (Sweden)

    Sebastián Carranza-Lira

    2008-12-01

    Full Text Available Sebastián Carranza-LiraReproductive Medicine, UMAE Hospital de Ginecología y Obstetricia “Luis Castelazo Ayala” Instituto Mexicano del Seguro Social, MéxicoAbstract: During menopause vasomotor symptoms are one of the main complaints about which women seek medical advice. For symptom control, several therapies have been used, among which hormone therapy has produced good results. One of these is estrogen monotherapy, which unfortunately may induce endometrial hyperplasia in women with an intact uterus. A progestin must be added to avoid this risk. Progestins may induce several secondary effects such as breast tenderness, hirsutism, edema and unfavorable lipid profile modifications. Recently a new progestin called drospirenone has been synthesized and used in combination with estradiol for the treatment of postmenopausal women. This progestin is derived from spironolactone, and lacks estrogenic, androgenic and glucocorticoid activities. Several studies have evaluated safety, efficacy and patient tolerability, and have shown a good profile in all these parameters. All studies agree that the combination of estradiol 1 mg plus drospirenone 2 mg is a good choice for postmenopausal women with vasomotor symptoms.Keywords: estradiol, drospirenone, postmenopause, review

  3. Association of Vasomotor and Other Menopausal Symptoms with Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Taulant Muka

    Full Text Available Vasomotor symptoms (hot flushes and night sweats and other symptoms, including depression, anxiety and panic attacks, are commonly experienced by menopausal women and have been associated with an unfavourable cardiovascular risk profile.To investigate whether presence of menopausal symptoms is associated with the development of cardiovascular disease (CVD.Five electronic databases (Medline, EMBASE and Web of Science were search until February 17th, 2015 to identify relevant studies. Observational cohort studies or randomised intervention studies were eligible for inclusion if they followed participants prospectively (at least 1 year of follow-up, and reported relevant estimates on the association of any vasomotor symptoms, or other menopausal symptoms, with risk of CVD, coronary heart disease (CHD, or stroke in perimenopausal, menopausal, or postmenopausal women. Data were extracted by two independent reviewers using a pre-designed data collection form. Separate pooled relative risks (RRs for age and non-established cardiovascular risk factors (e.g., education, ethnicity adjusted data and for established cardiovascular risk factors and potential mediators-adjusted data (e.g., smoking, body mass index, and hypertension were calculated.Out of 9,987 initially identified references, ten studies were selected, including 213,976 women with a total of 10,037 cardiovascular disease outcomes. The age and non-established cardiovascular risk factors adjusted RRs [95% confidence intervals] for development of CHD, Stroke and CVD comparing women with and without any menopausal symptoms were 1.34 [1.13-1.58], 1.30 [0.99-1.70], 1.48 [1.21-1.80] respectively, and the corresponding RRs adjusted for cardiovascular risk factors and potential mediators were 1.18 [1.03-1.35], 1.08 [0.89-1.32], 1.29 [0.98-1.71]. However, these analyses were limited by potential unmeasured confounding and the small number of studies on this topic.Presence of vasomotor symptoms and

  4. KIR channels tune electrical communication in cerebral arteries

    DEFF Research Database (Denmark)

    Sancho, Maria; Samson, Nina C; Hald, Bjorn O

    2017-01-01

    The conducted vasomotor response reflects electrical communication in the arterial wall and the distance signals spread is regulated by three factors including resident ion channels. This study defined the role of inward-rectifying K(+) channels (KIR) in governing electrical communication along...... hamster cerebral arteries. Focal KCl application induced a vasoconstriction that conducted robustly, indicative of electrical communication among cells. Inhibiting dominant K(+) conductances had no attenuating effect, the exception being Ba(2+) blockade of KIR Electrophysiology and Q-PCR analysis...... and the increased feedback arising from voltage-dependent-K(+) channels. In summary, this study shows that two KIR populations work collaboratively to govern electrical communication and the spread of vasomotor responses along cerebral arteries....

  5. Vasomotor symptoms among Japanese-American and European-American women living in Hilo, Hawaii.

    Science.gov (United States)

    Sievert, Lynnette Leidy; Morrison, Lynn; Brown, Daniel E; Reza, Angela M

    2007-01-01

    The Hilo Women's Health Survey was designed and administered to gather baseline data on women's health in Hilo, HI. This randomized, cross-sectional study allowed for a focus on ethnic differences in symptom reporting. The results presented here focus on hot flash and night sweat experience among Japanese-American and European-American women. Survey packets were mailed to street addresses associated with parcel numbers pulled randomly from Hilo tax maps. Of the 6,401 survey packets delivered to households, 1,824 questionnaires were completed and returned. The results reported here are based on 869 women aged 40 to 60, of whom 249 described themselves to be 100% Japanese and 203 described themselves to be 100% European-American. Logistic regression analyses were used to examine whether the relationship between ethnicity and vasomotor symptoms persisted after controlling for other variables. European-American participants were more likely to have ever experienced a hot flash as compared with Japanese-American participants (72% vs 53%, P<0.01). During the 2 weeks before the survey, European-American participants were more likely to have experienced hot flashes (P<0.05) and night sweats (P<0.01). In logistic regression analyses, after controlling for age, body mass index, menopause status, level of education, financial comfort, smoking habits, alcohol intake, exercise, use of hormone therapy, and soy intake, European-American women were still significantly more likely to have experienced hot flashes (odds ratio=1.858) and night sweats (odds ratio=2.672). The results, based on self-reporting of menopausal symptoms, indicate that Japanese-American women report fewer hot flashes and night sweats than European-American women. Japanese-American women reported a higher intake of soy, but soy intake was not associated with fewer vasomotor symptoms.

  6. Responsible conduct of research

    CERN Document Server

    Shamoo, Adil E

    2015-01-01

    Since the early 2000s, the field of Responsible Conduct of Research has become widely recognized as essential to scientific education, investigation, and training. At present, research institutions with public funding are expected to have some minimal training and education in RCR for their graduate students, fellows and trainees. These institutions also are expected to have a system in place for investigating and reporting misconduct in research or violations of regulations in research with human subjects, or in their applications to federal agencies for funding. Public scrutiny of the conduct of scientific researchers remains high. Media reports of misconduct scandals, biased research, violations of human research ethics rules, and moral controversies in research occur on a weekly basis. Since the 2009 publication of the 2nd edition of Shamoo and Resnik's Responsible Conduct of Research, there has been a vast expansion in the information, knowledge, methods, and diagnosis of problems related to RCR and the ...

  7. Characterizing human skin blood flow regulation in response to different local skin temperature perturbations

    NARCIS (Netherlands)

    Wu, Y.; Nieuwenhoff, M.D.; Huygen, Frank J.P.M.; van der Helm, F. C.T.; Niehof, S.P.; Schouten, A. C.

    2017-01-01

    Small nerve fibers regulate local skin blood flow in response to local thermal perturbations. Small nerve fiber function is difficult to assess with classical neurophysiological tests. In this study, a vasomotor response model in combination with a heating protocol was developed to quantitatively

  8. Cerebral vasomotor reactivity and apnea test in symptomatic and asymptomatic high-grade carotid stenosis

    Directory of Open Access Journals (Sweden)

    Lučić-Prokin Aleksandra

    2015-01-01

    Full Text Available Introduction. Cerebral vasomotor reactivity (VMR represents an autoregulatory response of the arterial trunks on the specific vasoactive stimuli, most commonly CO2. Objective. The aim of this retrospective study was to compare VMR in high-grade symptomatic (SCAS and asymptomatic carotid stenosis (ACAS, using the apnea test to evaluate the hemodynamic status. Methods. The study included 50 patients who were hospitalized at the neurology and vascular surgery departments as part of preparation for carotid endarterectomy. We evaluated VMR by calculating the breath holding index (BHI in 34 patients with SCAS and 16 patients with ACAS, with isolated high-grade carotid stenosis. We evaluated the impact of risk factors and collateral circulation on BHI, as well as the correlation between the degree of carotid stenosis and BHI. Results. A pathological BHI was more frequent in the SCAS group (p<0.01. There was no difference in the range of BHI values between the groups, both ipsilaterally and contralaterally. Only male gender was associated with pathological BHI in both groups (p<0.05. Collateral circulation did not exist in over 60% of all subjects. We confirmed a negative correlation between the degree of carotid stenosis and BHI. Conclusion. SCAS and ACAS patients present with different hemodynamics. While ACAS patients have stable hemodynamics, combination of hemodynamic and thromboembolic effects is characteristic of SCAS patients.

  9. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to soy isoflavones and maintenance of bone mineral density (ID 1655) and reduction of vasomotor symptoms associated with menopause (ID 1654, 1704, 2140, 3093, 3154, 3590

    DEFF Research Database (Denmark)

    Tetens, Inge

    and maintenance of bone mineral density and reduction of vasomotor symptoms associated with menopause. The food constituent that is the subject of the claim, soy isoflavones, is sufficiently characterised. The claimed effects, maintenance of bone mineral density and reduction of vasomotor symptoms associated...... with menopause, which are eligible for further assessment, are beneficial physiological effects. The proposed target populations are peri- and/or post-menopausal women. On the basis of the data presented, the Panel concludes that the evidence provided is insufficient to establish a cause and effect relationship...... between the consumption of soy isoflavones and maintenance of bone mineral density, and between the consumption of soy isoflavones and reduction of vasomotor symptoms associated with menopause....

  10. Promoting responsible research conduct in a developing world ...

    African Journals Online (AJOL)

    As reports of research misconduct seem to increase, research integrity and the promotion of responsible research conduct are important for academic institutions. This paper considers what research integrity means for individual researchers and institutions, and explores trends for promoting responsible research conduct.

  11. Vasomotor response to cold stimulation in human capsaicin-induced hyperalgesic area.

    Science.gov (United States)

    Pud, Dorit; Andersen, Ole Kaeseler; Arendt-Nielsen, Lars; Eisenberg, Elon; Yarnitsky, David

    2005-07-01

    Cooling the skin induces sympathetically driven vasoconstriction, with some vasoparalytic dilatation at the lowest temperatures. Neurogenic inflammation, on the other hand, entails vasodilatation. In this study we investigated the balance between vasoconstriction and vasodilatation in an area of experimentally induced secondary hyperalgesia (2 degrees HA), in response to low-temperature stimulations. Fourteen healthy volunteers were exposed to three 30-s long cold stimuli (20, 10, and 0 degrees C) applied, at three adjacent sites, before (baseline) and 8 min after intradermal injection of 50 microg capsaicin to the volar forearm. The cold stimuli were applied distally to the injection site within the 2 degrees HA. Blood flux (BF) and skin temperatures were measured at four different regions (proximally, and distally to the capsaicin injection and at the 0, 10, and 20 degrees C thermode sites) all within the 2 degrees HA. The vascular measurements were conducted five times. Results showed a marked increase in BF after baseline cold stimulation (Peffect (elevated BF) was found following the capsaicin injection compared with baseline for all regions (Pcooled area was dilated by 450+/-5.1%; The vasoconstrictive effect for the 10 and 20 degrees C did not overcome the capsaicin vasodilatation, but did reduce it, with dilatation of 364+/-7.0% and 329+/-7.3%, respectively. For 0 degrees C, a dilatation of 407+/-6.5% was seen. It is concluded that in this experimental model, and potentially in the equivalent clinical syndromes, vasodilatation induced by the inflammation is only slightly reduced by cold stimulation such that it is still dominant, despite some cold-induced vasoconstriction.

  12. VASOMOTOR ENDOTHELIAL FUNCTION AND MICROCIRCULATION IN ELDERLY PATIENTS WITH ISOLATED SYSTOLIC ARTERIAL HYPERTENSION: INFLUENCE OF "DRY" CARBONIC BATHS AND GENERAL LOW-FREQUENCY MAGNETOTHERAPY

    OpenAIRE

    Alypova, Elena

    2013-01-01

    Abstract. The comparative estimation of influence of the general low-frequency magnetotherapy (GLMT) and "dry" carbonic baths (DCB) on indicators of vasomotor endothelial function and microcirculation in elderly patients with isolated systolic (ISAH) arterial hypertension has been studied. The efficiency of application the combined use of the GLMT and "dry" carbonic baths DCB for correction of revealed disorders in comparing to the monovariant use of thees medical physical factors is establis...

  13. Burden of vasomotor symptoms in France, Germany, Italy, Spain, and the United Kingdom

    Directory of Open Access Journals (Sweden)

    DiBonaventura MD

    2013-05-01

    Full Text Available Marco daCosta DiBonaventura,1 Arthi Chandran,2 Ming-Ann Hsu,3 Andrew Bushmakin41Health Outcomes Practice, Kantar Health, New York, NY, USA; 2Global Health Economics and Outcomes Research, Pfizer, Inc., New York, NY, USA; 3Global Health Economics and Outcomes Research, Pfizer, Inc., Groton, CT, USA; 4Global Research and Development, Pfizer, Inc., Groton, CT, USABackground: Several studies have documented a significant association between vasomotor symptoms (VMS and a decrement in health outcomes among postmenopausal women, but these studies have mostly focused on the US. The aim of the current study was to broaden this investigation by examining the burden of VMS symptoms in the European Union with respect to both humanistic and economic outcomes.Methods: All women aged 40–75 years who completed the 2010 5EU (France, Germany, Italy, Spain, and the UK National Health and Wellness Survey were identified as potential respondents and invited to participate in an additional cross-sectional, Internet-based survey. Only postmenopausal women from 5EU were included in the current analyses (n = 3801. VMS was assessed using the Menopausal Rating Scale, and was used in multiple regression models as the primary predictor of health status (EQ-5D-3L, work productivity loss, and the number of physician visits due to menopause.Results: Over half (50.3% of postmenopausal women experienced either mild (24.6%, moderate (17.6%, or severe (8.1% VMS. Controlling for confounding variables, mild (b = −0.03, P < 0.05, moderate (b = −0.07, P < 0.05, and severe VMS (b = −0.17, P < 0.05 were each associated with worse health utilities relative to women without VMS. Similarly, increased resource use (b = 1.04–2.39, all P < 0.05, overall work impairment (b = 8.71–19.69, all P < 0.05, and activity impairment (b = 11.22–24.54, all P < 0.05 were also observed as VMS severity increased (with each b representing the difference between each level of severity and the

  14. MF-101, an estrogen receptor beta agonist for the treatment of vasomotor symptoms in peri- and postmenopausal women.

    Science.gov (United States)

    Stovall, Dale W; Pinkerton, Joann V

    2009-04-01

    During peri- and postmenopausal stages, the majority of women experience moderate-to-severe vasomotor symptoms, such as hot flashes and night sweats, that interfere with sleep and reduce quality of life. Estrogen alone or in combination with a progestagen has been the standard therapy for such vasomotor symptoms; however, this therapeutic regimen is associated with severe side effects, such as breast cancer or cardiovascular events. To provide a better treatment option for menopausal women, Bionovo Inc is developing the estrogen receptor (ER)beta-selective agonist MF-101. Selective ER agonists can stimulate either ERalpha or ERbeta and induce tissue-specific estrogen-like effects, thus providing a safer alternative to conventional hormone therapy. MF-101 is derived from 22 herbs that are traditionally used in Chinese medicine for the treatment of menopausal symptoms. MF-101 did not promote the growth of breast cancer cells or stimulate uterine growth in preclinical studies and, in a phase II trial, was demonstrated to be safe and more effective in reducing the frequency and severity of hot flashes in postmenopausal women compared with placebo. To confirm the safety and efficacy of MF-101, larger phase III trials were planned for 2009. Although MF-101 appears to be a promising therapeutic, the herbal composition of the drug may be a disadvantage, because of the increased risk of causing allergic reactions in the general population. Studies with the MF-101-isolated active compounds liquiritigen and chalcone demonstrated selectivity for ERbeta, with no induction of proliferative events. If these isolates were demonstrated to be as effective and safe in clinical trials as preliminary data suggest regarding MF-101, these compounds could change the way clinicians treat menopause-associated symptoms.

  15. Sex differences in the modulation of vasomotor sympathetic outflow during static handgrip exercise in healthy young humans

    Science.gov (United States)

    Jarvis, Sara S.; VanGundy, Tiffany B.; Galbreath, M. Melyn; Shibata, Shigeki; Okazaki, Kazunobu; Reelick, Miriam F.; Levine, Benjamin D.

    2011-01-01

    Sex differences in sympathetic neural control during static exercise in humans are few and the findings are inconsistent. We hypothesized women would have an attenuated vasomotor sympathetic response to static exercise, which would be further reduced during the high sex hormone [midluteal (ML)] vs. the low hormone phase [early follicular (EF)]. We measured heart rate (HR), blood pressure (BP), and muscle sympathetic nerve activity (MSNA) in 11 women and 10 men during a cold pressor test (CPT) and static handgrip to fatigue with 2 min of postexercise circulatory arrest (PECA). HR increased during handgrip, reached its peak at fatigue, and was comparable between sexes. BP increased during handgrip and PECA where men had larger increases from baseline. Mean ± SD MSNA burst frequency (BF) during handgrip and PECA was lower in women (EF, P < 0.05), as was ΔMSNA-BF smaller (main effect, both P < 0.01). ΔTotal activity was higher in men at fatigue (EF: 632 ± 418 vs. ML: 598 ± 342 vs. men: 1,025 ± 416 a.u./min, P < 0.001 for EF and ML vs. men) and during PECA (EF: 354 ± 321 vs. ML: 341 ± 199 vs. men: 599 ± 327 a.u./min, P < 0.05 for EF and ML vs. men). During CPT, HR and MSNA responses were similar between sexes and hormone phases, confirming that central integration and the sympathetic efferent pathway was comparable between the sexes and across hormone phases. Women demonstrated a blunted metaboreflex, unaffected by sex hormones, which may be due to differences in muscle mass or fiber type and, therefore, metabolic stimulation of group IV afferents. PMID:21508291

  16. Motives of Socially Responsible Business Conduct

    NARCIS (Netherlands)

    Graafland, J.J.; Kaptein, M.; Mazereeuw V/d Duijn Schouten, C.

    2010-01-01

    The social and ecological challenges that governments face have raised their interest in socially responsible business conduct (SRBC). In this article we analyze the motives of executives to perform SRBC. We distinguish three types of motives: financial, ethical and altruistic motives. We test the

  17. The university and the responsible conduct of research: who is responsible for what?

    Science.gov (United States)

    Alfredo, Katherine; Hart, Hillary

    2011-09-01

    Research misconduct has been thoroughly discussed in the literature, but mainly in terms of definitions and prescriptions for proper conduct. Even when case studies are cited, they are generally used as a repository of "lessons learned." What has been lacking from this conversation is how the lessons of responsible conduct of research are imparted in the first place to graduate students, especially those in technical fields such as engineering. Nor has there been much conversation about who is responsible for what in training students in Responsible Conduct of Research or in allocating blame in cases of misconduct. This paper explores three seemingly disparate cases of misconduct-the 2004 plagiarism scandal at Ohio University; the famous Robert Millikan article of 1913, in which his reported data selection did not match his notebooks; and the 1990 fabrication scandal in Dr. Leroy Hood's research lab. Comparing these cases provides a way to look at the relationship between the graduate student (or trainee) and his/her advisor (a relationship that has been shown to be the most influential one for the student) as well as at possibly differential treatment for established researchers and researchers-in-training, in cases of misconduct. This paper reflects on the rights and responsibilities of research advisers and their students and offers suggestions for clarifying both those responsibilities and the particularly murky areas of research-conduct guidelines.

  18. Omega-3 versus isoflavones in the control of vasomotor symptoms in postmenopausal women.

    Science.gov (United States)

    Palacios, S; Lilue, M; Mejia, A; Menendez, C

    2017-12-01

    Determine the efficacy and tolerability of omega-3 fatty acids versus soybean isoflavones in reducing the vasomotor symptoms (VMSs) frequency in postmenopausal women. A randomized, prospective, two-arm study was performed in healthy postmenopausal women aged 45-65. The two arms were: two capsules/day of omega-3 (425 mg of omega-3/capsule) administered orally (n = 38) and two tablets/day of soybean isoflavones (54.4 mg of isoflavones/tablet) (n = 30), over 16 weeks. The mean baseline frequency of moderate and severe VMSs per week in the omega-3 group was 24.56 and 23.90, respectively, and 19.65 and 19.51 in the isoflavone group. After 4 months, the reduction in moderate and severe hot flashes with omega-3 was significant (p Omega-3 did not demonstrate significant efficacy differences versus isoflavones over time. The use of omega-3 has a beneficial effect on hot flash reduction after 4 months of treatment. This is comparable to the benefits found with soybean isoflavones after 3-4 weeks and after 4 months in severe hot flash women, but higher than those found with soybean isoflavones in moderate symptom women.

  19. Cigarette smoking leads to reduced relaxant responses of the cutaneous microcirculation

    Directory of Open Access Journals (Sweden)

    Marie-Louise Edvinsson

    2008-06-01

    Full Text Available Marie-Louise Edvinsson, Sven E Andersson, Cang-Bao Xu, Lars EdvinssonDepartment of Emergency Medicine, Institute of Clinical Sciences in Lund, University Hospital of Lund, Lund, SwedenBackground: Smoking is a major risk factor for cardiovascular disease. The present study was undertaken to examine if cigarette smoking translates into reduced relaxant responses of the peripheral microcirculation.Methods: The cutaneous forearm blood flow was measured by laser Doppler flowmetry. The vasodilator response to the iontophorectic administration of acetylcholine (ACh, acting via an endothelial mechanism, and sodium nitroprusside (SNP, and acting via a smooth muscle mechanism were studied. The study population consisted of 17 nonsmokers and 17 current smokers (mean age 64 ± 2 years, 13 females and 4 males in each matched group.Results: There was no difference between the groups in baseline characteristics or in basal flow. Smokers showed however significantly reduced responses to both ACh (mean ± SEM, from 973 ± 137% in nonsmokers to 651 ± 114% in smokers, p < 0.05 and SNP (from 575 ± 111% in nonsmokers to 355 ± 83% in smokers, p < 0.05. The response to the local heating (44°C was reduced in smokers (from 1188 ± 215% in nonsmokers to 714 ± 107% in smokers, p < 0.01. In addition, there was no difference between men and women within the groups.Conclusions: The data show that cigarette smoking results in reduced peripheral microvascular responses to both endothelial and smooth muscle cell stimulation in healthy subjects, suggesting a generalized microvascular vasomotor function.Keywords: smoking, nonsmokers, acetylcholine, vasomotor function, cutaneous microcirculation

  20. Menopause is associated with self-reported poor sleep quality in women without vasomotor symptoms.

    Science.gov (United States)

    Hung, Hao-Chang; Lu, Feng-Hwa; Ou, Horng-Yih; Wu, Jin-Shang; Yang, Yi-Ching; Chang, Chih-Jen

    2014-08-01

    The aim of this study was to investigate the relationship between menopause and self-reported sleep quality in Chinese women without vasomotor symptoms. Cross-sectional data were collected from a decoded database of the National Cheng Kung University Hospital. Menopause was defined as absence of menses for at least 12 months or a history of hysterectomy and oophorectomy. Self-reported sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). A higher global PSQI score indicates poorer self-reported sleep quality, and a global PSQI score greater than 5 differentiates poor sleepers from good sleepers. Of the 1,088 women recruited, 353 (32.4%) were in postmenopause status. Postmenopausal women had higher mean (SD) global PSQI scores (8.0 [3.3] vs. 6.1 [2.2], P menopause (β = 1.532; 95% CI, 1.135 to 1.949; P menopause (odds ratio, 1.453; 95% CI, 1.030 to 2.051; P menopause and snoring are associated with an increased risk of poor self-reported sleep quality independently of cardiometabolic factors and lifestyle, whereas long sleep duration is associated with a decreased risk of poor self-reported sleep quality.

  1. Cognitive performance correlates with cerebrovascular impairments in multi-infarct dementia

    International Nuclear Information System (INIS)

    Judd, B.W.; Meyer, J.S.; Rogers, R.L.; Gandhi, S.; Tanahashi, N.; Mortel, K.F.; Tawaklna, T.

    1986-01-01

    Cerebral blood flow (CBF) was measured by the 133 Xe inhalation method in patients with multi-infarct dementia (MID, N = 26), Alzheimer's dementia (AD, N = 19), and among age-matched, neurologically normal, healthy volunteers (N = 26). Cognitive performance was assessed in all subjects using the Cognitive Capacity Screening Examination (CCSE). Cerebral vasomotor responses were calculated from differences in values of mean hemispheric gray matter blood flow (Delta CBF) measured during inhalation of 100% oxygen (hyperoxia) compared with CBF measured while breathing room air. Significant correlations were found between CCSE performance and vasomotor responsiveness in patients with MID (P less than .01), but not in patients with AD or in neurologically normal volunteers. Loss of vasomotor responsiveness is an indicator of cerebrovascular disease with rigidity and/or loss of reactivity of cerebral vessels, which impairs cerebrovascular responses to situational demands and predisposes to cerebral ischemia. Loss of cerebral vasomotor responsiveness among MID patients, which is a biologic marker of cerebrovascular disease, provides confirmatory evidence of the vascular etiology of MID and assists in separating MID from AD patients

  2. Computer incident response and forensics team management conducting a successful incident response

    CERN Document Server

    Johnson, Leighton

    2013-01-01

    Computer Incident Response and Forensics Team Management provides security professionals with a complete handbook of computer incident response from the perspective of forensics team management. This unique approach teaches readers the concepts and principles they need to conduct a successful incident response investigation, ensuring that proven policies and procedures are established and followed by all team members. Leighton R. Johnson III describes the processes within an incident response event and shows the crucial importance of skillful forensics team management, including when and where the transition to forensics investigation should occur during an incident response event. The book also provides discussions of key incident response components. Provides readers with a complete handbook on computer incident response from the perspective of forensics team management Identify the key steps to completing a successful computer incident response investigation Defines the qualities necessary to become a succ...

  3. Safety of veralipride for the treatment of vasomotor symptoms of menopause.

    Science.gov (United States)

    Valencia, Marcelino Hernández; Arias, María de Jesús Vega; González, Cuauhtémoc Celis; Marín, Imelda Hernández; González, Juan Humberto Martín; Campos, Enrique Rafael Morcate; Rodríguez, María Antonia Basavilvazo; Álvarez, Ignacio Morales; Vargas, María Antonia Valdés; Flores, José Braulio Everardo Otero; Haro, Samuel Santoyo; Bonilla, Manuel Cortes; Escudero, Roberto Bernardo; Campero, Rosalba Alonso

    2014-05-01

    Veralipride is a nonhormonal option for the treatment of vasomotor symptoms of menopause. Incidence of adverse events in a Mexican population and drug compliance according to correct use were evaluated. We carried out a longitudinal, prospective, and analytical study in Mexican women who received veralipride to treat symptoms of menopause from 2011 to 2012. There were 386 treatment cycles; 272 were assigned to dosing schedule 1, which included 20 days of treatment with 10 days of suspension, and 114 were assigned to dosing schedule 2, which included 5 days of treatment and 2 days of suspension. A total of 57 adverse events were registered during the 386-month treatment. For the 20 × 10 dosing schedule, the highest incidence was observed for anxiety (2.2%), drowsiness, and weakness (1.5%); for the 5 × 2 dosing schedule, the highest incidence was observed for drowsiness (5.3%) and headache (2.6%). The Hamilton Depression Rating Scale was used to assess the presence and severity of depression; improvement was noted. The Unified Parkinson's Disease Rating Scale was used to assess neurological movement disorders; no adverse neurological events were detected. Based on the assessments of both women and physicians, the highest frequency was observed for "very satisfied" (45.5% and 52.3%, respectively), followed by "satisfied" (23.9% and 27.3%, respectively). Both dosing schedules show acceptable safety profiles for up to 6 months of use when used according to the contraindications in the current prescribing information for standard use (2012) and recent medical literature.

  4. Symptomatic Response to Divalproex in Subtypes of Conduct Disorder

    Science.gov (United States)

    Padhy, Ranjit; Saxena, Kirti; Remsing, Lisa; Huemer, Julia; Plattner, Belinda; Steiner, Hans

    2011-01-01

    To investigate response to Divalproex sodium (DVPX) with respect to Reactive/Affective/Defensive/Impulsive (RADI) and Proactive/Instrumental/Premeditated (PIP) aggression among adolescent males with conduct disorder (CD), using results from a randomized, double-blind, placebo-controlled trial. It was hypothesized that DVPX response among…

  5. LPS from Porphyromonas gingivalis increases the sensitivity of contractile response mediated by endothelin-B (ET(B)) receptors in cultured endothelium-intact rat coronary arteries

    DEFF Research Database (Denmark)

    Ghorbani, Bahareh; Holmstrup, Palle; Edvinsson, Lars

    2010-01-01

    The purpose of our study was to examine if lipopolysaccharide (LPS) from Porphyromonas gingivalis (P.g.) modifies the vasomotor responses to Endothelin-1 (ET-1) and Sarafotoxin 6c (S6c) in rat coronary arteries. The arteries were studied directly or following organ culture for 24h in absence...

  6. Enhanced pain and autonomic responses to ambiguous visual stimuli in chronic Complex Regional Pain Syndrome (CRPS) type I.

    Science.gov (United States)

    Cohen, H E; Hall, J; Harris, N; McCabe, C S; Blake, D R; Jänig, W

    2012-02-01

    Cortical reorganisation of sensory, motor and autonomic systems can lead to dysfunctional central integrative control. This may contribute to signs and symptoms of Complex Regional Pain Syndrome (CRPS), including pain. It has been hypothesised that central neuroplastic changes may cause afferent sensory feedback conflicts and produce pain. We investigated autonomic responses produced by ambiguous visual stimuli (AVS) in CRPS, and their relationship to pain. Thirty CRPS patients with upper limb involvement and 30 age and sex matched healthy controls had sympathetic autonomic function assessed using laser Doppler flowmetry of the finger pulp at baseline and while viewing a control figure or AVS. Compared to controls, there were diminished vasoconstrictor responses and a significant difference in the ratio of response between affected and unaffected limbs (symmetry ratio) to a deep breath and viewing AVS. While viewing visual stimuli, 33.5% of patients had asymmetric vasomotor responses and all healthy controls had a homologous symmetric pattern of response. Nineteen (61%) CRPS patients had enhanced pain within seconds of viewing the AVS. All the asymmetric vasomotor responses were in this group, and were not predictable from baseline autonomic function. Ten patients had accompanying dystonic reactions in their affected limb: 50% were in the asymmetric sub-group. In conclusion, there is a group of CRPS patients that demonstrate abnormal pain networks interacting with central somatomotor and autonomic integrational pathways. © 2011 European Federation of International Association for the Study of Pain Chapters.

  7. Electromagnetic response of a conductor with complex conductivity

    Science.gov (United States)

    Leylekian, L.; Ocio, M.; Hammann, J.

    1993-02-01

    The aim of this paper is to describe the electromagnetic response of a conductor with complex conductivity. We will show how the geometry of the measuring apparatus can modify the amplitude of this response. We will particularly emphasize the role that plays a complex conductivity, as we can find in granular superconductors, on the mesured magnetic susceptibility of the sample. Cet article a pour but de décrire la réponse électromagnétique d'un conducteur muni d'une conductivité complexe. Nous montrerons comment la géométrie du dispositif de mesure peut modifier l'amplitude de cette réponse. Nous insisterons particulièrement sur le rôle que joue une conductivité complexe, comme nous pouvons en trouver dans les supraconducteurs granulaires, sur la susceptibilité magnétique mesurée de l'échantillon.

  8. Management of menopause-associated vasomotor symptoms: Current treatment options, challenges and future directions

    Directory of Open Access Journals (Sweden)

    Deirdre R Pachman

    2010-05-01

    Full Text Available Deirdre R Pachman1, Jason M Jones1, Charles L Loprinzi21Internal Medicine, Mayo Clinic, Rochester, MN, USA; 2Medical Oncology, Mayo Clinic, Rochester, MN, USAAbstract: Hot flashes are one of the most common and distressing symptoms associated with menopause, occurring in more than 75% of postmenopausal women. They are especially problematic in breast cancer patients since some breast cancer therapies can induce hot flashes. For mild hot flashes, it is proposed that behavioral modifications are the first step in management. Hormonal therapies, including estrogens and progestogens, are the most well known effective agents in relieving hot flashes; however, the safety of these agents is controversial. There is an increasing amount of literature on nonhormonal agents for the treatment of hot flashes. The most promising data regard newer antidepressant agents such as venlafaxine, which reduces hot flashes by about 60%. Gabapentin is another nonhormonal agent that is effective in reducing hot flashes. While many complimentary therapies, including phytoestrogens, black cohosh, and dehydroepiandrosterone, have been explored for the treatment of hot flashes; none can be recommended at this time. Furthermore, there is a lack of strong evidence to support exercise, yoga, or relaxation for the treatment of hot flashes. Paced respirations and hypnosis appear to be promising enough to warrant further investigation. Another promising nonpharmacological therapy, currently under investigation, involves a stellate ganglion block.Keywords: vasomotor symptoms, hot flashes, menopause, therapy

  9. Impact of the severity of vasomotor symptoms on health status, resource use, and productivity.

    Science.gov (United States)

    Whiteley, Jennifer; Wagner, Jan-Samuel; Bushmakin, Andrew; Kopenhafer, Lewis; Dibonaventura, Marco; Racketa, Jill

    2013-05-01

    The current study characterizes health-related quality of life, work productivity, and resource use among postmenopausal women by severity of vasomotor symptoms (VMS). Participants were selected from the 2010 US National Health and Wellness Survey. Women aged 40 to 75 years who did not report a history of menstrual bleeding or spotting for 1 year were eligible for analysis (N = 3,267). Cohorts of women with no VMS (n = 1,740), mild VMS (n = 931), moderate VMS (n = 462), and severe VMS (n = 134) were compared after controlling for demographic and health characteristics. Outcome measures were assessed using linear models and included health status, work productivity within the past 7 days, and healthcare resource use within the past 6 months. The mean age of women experiencing severe VMS was 57.92 years. After demographic and health characteristics had been controlled for, women experiencing severe and moderate VMS reported significantly lower mean health status scores compared with women with no symptoms (P women with severe, moderate, or mild symptoms than among women with no symptoms (P women experiencing VMS, women with severe and moderate symptoms had adjusted presenteeism of 24.28% and 14.3%, versus 4.33% in women with mild symptoms (P women with mild symptoms (P women, a greater severity of VMS is significantly associated with lower levels of health status and work productivity, and greater healthcare resource use.

  10. Physiological responses induced by pleasant stimuli.

    Science.gov (United States)

    Watanuki, Shigeki; Kim, Yeon-Kyu

    2005-01-01

    The specific physiological responses induced by pleasant stimuli were investigated in this study. Various physiological responses of the brain (encephaloelectrogram; EEG), autonomic nervous system (ANS), immune system and endocrine system were monitored when pleasant stimuli such as odors, emotional pictures and rakugo, a typical Japanese comical story-telling, were presented to subjects. The results revealed that (i) EEG activities of the left frontal brain region were enhanced by a pleasant odor; (ii) emotional pictures related to primitive element such as nudes and erotic couples elevated vasomotor sympathetic nervous activity; and (iii) an increase in secretory immunoglobulin A (s-IgA) and a decrease in salivary cortisol (s-cortisol) were induced by rakugo-derived linguistic pleasant emotion. Pleasant emotion is complicated state. However, by considering the evolutionary history of human being, it is possible to assess and evaluate pleasant emotion from certain physiological responses by appropriately summating various physiological parameters.

  11. Influence of Conductive and Semi-Conductive Nanoparticles on the Dielectric Response of Natural Ester-Based Nanofluid Insulation

    Directory of Open Access Journals (Sweden)

    M. Z. H. Makmud

    2018-02-01

    Full Text Available Nowadays, studies of alternative liquid insulation in high voltage apparatus have become increasingly important due to higher concerns regarding safety, sustainable resources and environmentally friendly issues. To fulfil this demand, natural ester has been extensively studied and it can become a potential product to replace mineral oil in power transformers. In addition, the incorporation of nanoparticles has been remarkable in producing improved characteristics of insulating oil. Although much extensive research has been carried out, there is no general agreement on the influence on the dielectric response of base oil due to the addition of different amounts and conductivity types of nanoparticle concentrations. Therefore, in this work, a natural ester-based nanofluid was prepared by a two-step method using iron oxide (Fe2O3 and titanium dioxide (TiO2 as the conductive and semi-conductive nanoparticles, respectively. The concentration amount of each nanoparticle types was varied at 0.01, 0.1 and 1.0 g/L. The nanofluid samples were characterised by visual inspection, morphology and the dynamic light scattering (DLS method before the dielectric response measurement was carried out for frequency-dependent spectroscopy (FDS, current-voltage (I-V, and dielectric breakdown (BD strength. The results show that the dielectric spectra and I-V curves of nanofluid-based iron oxide increases with the increase of iron oxide nanoparticle loading, while for titanium dioxide, it exhibits a decreasing response. The dielectric BD strength is enhanced for both types of nanoparticles at 0.01 g/L concentration. However, the increasing amount of nanoparticles at 0.1 and 1.0 g/L led to a contrary dielectric BD response. Thus, the results indicate that the augmentation of conductive nanoparticles in the suspension can lead to overlapping mechanisms. Consequently, this reduces the BD strength compared to pristine materials during electron injection in high electric

  12. Complex conductivity response to silver nanoparticles in ...

    Science.gov (United States)

    The increase in the use of nanoscale materials in consumer products has resulted in a growing concern of their potential hazard to ecosystems and public health from their accidental or intentional introduction to the environment. Key environmental, health, and safety research needs include knowledge and methods for their detection, characterization, fate, and transport. Specifically, techniques available for the direct detection and quantification of their fate and transport in the environment are limited. Their small size, high surface area to volume ratio, interfacial, and electrical properties make metallic nanoparticles, such as silver nanoparticles, good targets for detection using electrical geophysical techniques. Here we measured the complex conductivity response to silver nanoparticles in sand columns under varying moisture conditions (0–30%), nanoparticle concentrations (0–10 mg/g), lithology (presence of clay), pore water salinity (0.0275 and 0.1000 S/m), and particle size (35, 90–210 and 1500–2500 nm). Based on the Cole-Cole relaxation models we obtained the chargeability and the time constant. We demonstrate that complex conductivity can detect silver nanoparticles in porous media with the response enhanced by higher concentrations of silver nanoparticles, moisture content, ionic strength, clay content and particle diameter. Quantification of the volumetric silver nanoparticles content in the porous media can also be obtained from complex co

  13. Efeito vasomotor após intoxicação aguda com bupivacaína e levobupivacaína via intraperitoneal em ratos, analisado por imagem infravermelha digital

    Directory of Open Access Journals (Sweden)

    Angelo Manoel Grande Carstens

    2011-04-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O estudo do efeito vasomotor dos anestésicos locais (AL é de suma importância para a análise da ocorrência de efeitos cardiotóxicos, neurotóxicos e interações medicamentosas. Com a finalidade de encontrar um fármaco mais seguro do que a bupivacaína racêmica, o presente estudo teve por objetivo a análise por imagem infravermelha digital do efeito vasomotor da intoxicação aguda da bupivacaína e da levobupivacaína via intraperitoneal em ratos. MÉTODO: Utilizaram-se 30 ratos machos da linhagem Wistar, alocados em três grupos (n = 10 e submetidos a uma injeção intraperitoneal de AL. No Grupo C (Controle, foi realizada injeção intraperitoneal de soro fisiológico 0,9% 1 mL. No Grupo B (bupivacaína, injeção intraperitoneal de bupivacaína racêmica a 0,5% (R50-S50, dose de 20 mg.kg-1 de peso. No Grupo L (levobupivacaína, injeção intraperitoneal de levobupivacaína a 0,5%, excesso enantiomérico (S75-R25 em dose de 20 mg.kg-1 de peso. Procedeu-se à filmagem termográfica contínua desde o momento da pré-injeção até 30 minutos após a injeção. Os resultados das filmagens foram analisados em forma gráfica, verificando-se a temperatura máxima de cada rato e a temperatura média do sistema que abrigava o animal. RESULTADOS: Os resultados da análise gráfica revelaram que não houve diferença entre o Grupo L e o Grupo C, e a temperatura média permaneceu estável durante todo o experimento em ambos os grupos. No Grupo B, houve um fenômeno de aumento de temperatura após a injeção intraperitoneal de bupivacaína. CONCLUSÕES: Os resultados demonstraram que o efeito vasomotor da toxicidade aguda da levobupivacaína foi semelhante ao Grupo C com soro fisiológico, por meio de estudos macroscópicos por filmagem digital infravermelha, e que houve alterações vasomotoras (vasoconstrição com a intoxicação por bupivacaína em relação ao Grupo C e em relação ao Grupo L.

  14. Increased Contractile Response to Noradrenaline Induced By Factors Associated with the Metabolic Syndrome in Cultured Small Mesenteric Arteries

    DEFF Research Database (Denmark)

    Blædel, Martin; Sams, Anette; Boonen, Harrie C M

    2016-01-01

    UNLABELLED: This study investigated the effect of the metabolic syndrome associated risk factors hyperglycemia (glucose [Glc]), hyperinsulinemia (insulin [Ins]) and low-grade inflammation (tumor necrosis factor α [TNFα]) on the vasomotor responses of resistance arteries. Isolated small mesenteric...... arteries from 3-month-old Sprague-Dawley rats, were suspended for 21-23 h in tissue cultures containing either elevated Glc (30 mmol/l), Ins (100 nmol/l), TNFα (100 ng/ml) or combinations thereof. After incubation, the vascular response to noradrenaline (NA), phenylephrine, isoprenaline and NA...... in vascular tone....

  15. Responsible Conduct of Research in Communication Sciences and Disorders: Faculty and Student Perceptions

    Science.gov (United States)

    Minifie, Fred D.; Robey, Randall R.; Horner, Jennifer; Ingham, Janis C.; Lansing, Charissa; McCartney, James H.; Alldredge, Elham-Eid; Slater, Sarah C.; Moss, Sharon E.

    2011-01-01

    Purpose: Two Web-based surveys (Surveys I and II) were used to assess perceptions of faculty and students in Communication Sciences and Disorders (CSD) regarding the responsible conduct of research (RCR). Method: Survey questions addressed 9 RCR domains thought important to the responsible conduct of research: (a) human subjects protections; (b)…

  16. Practical Guide to Conducting an Item Response Theory Analysis

    Science.gov (United States)

    Toland, Michael D.

    2014-01-01

    Item response theory (IRT) is a psychometric technique used in the development, evaluation, improvement, and scoring of multi-item scales. This pedagogical article provides the necessary information needed to understand how to conduct, interpret, and report results from two commonly used ordered polytomous IRT models (Samejima's graded…

  17. Methods of Using a Magnetic Field Response Sensor Within Closed, Electrically Conductive Containers

    Science.gov (United States)

    Woodward, Stanley E.; Taylor, Bryant D.

    2010-01-01

    Magnetic field response sensors are a class of sensors that are powered via oscillating magnetic fields, and when electrically active, respond with their own magnetic fields with attributes dependent upon the magnitude of the physical quantity being measured. A magnetic field response recorder powers and interrogates the magnetic sensors [see Magnetic-Field-Response Measurement- Acquisition System, NASA Tech Briefs Vol. 30, No, 6 (June 2006, page 28)]. Electrically conductive containers have low transmissivity for radio frequency (RF) energy and thus present problems for magnetic field response sensors. It is necessary in some applications to have a magnetic field response sensor s capacitor placed in these containers. Proximity to conductive surfaces alters the inductance and capacitance of the sensors. As the sensor gets closer to a conductive surface, the electric field and magnetic field energy of the sensor is reduced due to eddy currents being induced in the conductive surface. Therefore, the capacitors and inductors cannot be affixed to a conductive surface or embedded in a conductive material. It is necessary to have a fixed separation away from the conductive material. The minimum distance for separation is determined by the desired sensor response signal to noise ratio. Although the inductance is less than what it would be if it were not in proximity to the conductive surface, the inductance is fixed. As long as the inductance is fixed, all variations of the magnetic field response are due to capacitance changes. Numerous variations of inductor mounting can be utilized, such as providing a housing that provides separation from the conductive material as well as protection from impact damage. The sensor can be on the same flexible substrate with a narrow throat portion of the sensor between the inductor and the capacitor, Figure 1. The throat is of sufficient length to allow the capacitor to be appropriately placed within the container and the inductor

  18. Dielectric response and ac conductivity analysis of hafnium oxide nanopowder

    International Nuclear Information System (INIS)

    Karahaliou, P K; Xanthopoulos, N; Krontiras, C A; Georga, S N

    2012-01-01

    The dielectric response of hafnium oxide nanopowder was studied in the frequency range of 10 -2 -10 6 MHz and in the temperature range of 20-180 °C. Broadband dielectric spectroscopy was applied and the experimental results were analyzed and discussed using the electric modulus (M*) and alternating current (ac) conductivity formalisms. The analyses of the dc conductivity and electric modulus data revealed the presence of mechanisms which are thermally activated, both with almost the same activation energy of 1.01 eV. A fitting procedure involving the superposition of the thermally activated dc conductivity, the universal dielectric responce and the near constant loss terms has been used to describe the frequency evolution of the real part of the specific electrical conductivity. The conductivity master curve was obtained, suggesting that the time-temperature superposition principle applies for the studied system, thus implying that the conductivity mechanisms are temperature independent.

  19. Doing global science a guide to responsible conduct in the global research enterprise

    CERN Document Server

    InterAcademy Partnership

    2016-01-01

    This concise introductory guide explains the values that should inform the responsible conduct of scientific research in today's global setting. Featuring accessible discussions and ample real-world scenarios, Doing Global Science covers proper conduct, fraud and bias, the researcher's responsibilities to society, communication with the public, and much more. The book places special emphasis on the international and highly networked environment in which modern research is done, presenting science as an enterprise that is being transformed by globalization, interdisciplinary research projects, team science, and information technologies. Accessibly written by an InterAcademy Partnership committee comprised of leading scientists from around the world, Doing Global Science is required reading for students, practitioners, and anyone concerned about the responsible conduct of science today.

  20. Predictions of the electro-mechanical response of conductive CNT-polymer composites

    Science.gov (United States)

    Matos, Miguel A. S.; Tagarielli, Vito L.; Baiz-Villafranca, Pedro M.; Pinho, Silvestre T.

    2018-05-01

    We present finite element simulations to predict the conductivity, elastic response and strain-sensing capability of conductive composites comprising a polymeric matrix and carbon nanotubes. Realistic representative volume elements (RVE) of the microstructure are generated and both constituents are modelled as linear elastic solids, with resistivity independent of strain; the electrical contact between nanotubes is represented by a new element which accounts for quantum tunnelling effects and captures the sensitivity of conductivity to separation. Monte Carlo simulations are conducted and the sensitivity of the predictions to RVE size is explored. Predictions of modulus and conductivity are found in good agreement with published results. The strain-sensing capability of the material is explored for multiaxial strain states.

  1. Synthesis of Conductive Polymeric Nanocomposites for Applications in Responsive Materials

    Science.gov (United States)

    Chavez, Jessica

    The development of next generation "smart" textiles has emerged with significant interest due to the immense demand for high-performance wearable technology. The economic market for wearable technologies is predicted to increase significantly in both volume and value. In the next four years, the wearable technology market will be valued at $34 billion. This large demand has opened up a new research area involving smart wearable devices and conductive fabrics. Many research groups have taken various paths to study and ultimately fabricate wearable devices. Due to the limiting capabilities of conventional conductors, researchers have centered their research on the integration of conductive polymers into textile materials for applications involving responsive material. Conducive polymers are very unique organic molecules that have the ability to transfer electrons across their molecular structure due to the excess presence of pi-electrons. Conductive polymers are favored over conventional conductors because they can be easily manipulated and integrated into flexible material. Two very common conductive polymers are polyaniline (PANI) and polypyrrole (PPY) because of their large favorability in literature, high conductance values, and environmental stability. Common commercial fibers were coated via the chemical polymerization of PANI or PPY. A series of reactions were done to study the polymerization process of each polymer. The conductive efficiency of each conducting polymer is highly dependent on the type of reactants used, the acidic nature of the reaction, and the temperature of the reaction. The coated commercial fiber nanocomposites produced higher conductivity values when the polymerization reaction was run using ammonium peroxydisulfate (APS) as the oxidizing agent, run in an acidic environment, and run at very low temperatures. Other factors that improved the overall efficiency of the coated commercial fiber nanocomposites was the increase in polymer

  2. Skin conductance response to the pain of others predicts later costly helping.

    Directory of Open Access Journals (Sweden)

    Grit Hein

    Full Text Available People show autonomic responses when they empathize with the suffering of another person. However, little is known about how these autonomic changes are related to prosocial behavior. We measured skin conductance responses (SCRs and affect ratings in participants while either receiving painful stimulation themselves, or observing pain being inflicted on another person. In a later session, they could prevent the infliction of pain in the other by choosing to endure pain themselves. Our results show that the strength of empathy-related vicarious skin conductance responses predicts later costly helping. Moreover, the higher the match between SCR magnitudes during the observation of pain in others and SCR magnitude during self pain, the more likely a person is to engage in costly helping. We conclude that prosocial motivation is fostered by the strength of the vicarious autonomic response as well as its match with first-hand autonomic experience.

  3. Conductivity-Dependent Strain Response of Carbon Nanotube Treated Bacterial Nanocellulose

    Directory of Open Access Journals (Sweden)

    S. Farjana

    2013-01-01

    Full Text Available This paper reports the strain sensitivity of flexible, electrically conductive, and nanostructured cellulose which was prepared by modification of bacterial cellulose with double-walled carbon nanotubes (DWCNTs and multiwalled carbon nanotubes (MWCNTs. The electrical conductivity depends on the modifying agent and its dispersion process. The conductivity of the samples obtained from bacterial cellulose (BNC pellicles modified with DWCNT was in the range from 0.034 S·cm−1 to 0.39 S·cm−1, and for BNC pellicles modified with MWCNTs it was from 0.12 S·cm−1 to 1.6 S·cm−1. The strain-induced electromechanical response, resistance versus strain, was monitored during the application of tensile force in order to study the sensitivity of the modified nanocellulose. A maximum gauge factor of 252 was found from the highest conductive sample treated by MWCNT. It has been observed that the sensitivity of the sample depends on the conductivity of the modified cellulose.

  4. The influence of increased membrane conductance on response properties of spinal motoneurons

    DEFF Research Database (Denmark)

    Grigonis, Ramunas; Guzulaitis, Robertas; Buisas, Rokas

    2016-01-01

    During functional spinal neural network activity motoneurons receive massive synaptic excitation and inhibition, and their membrane conductance increases considerably – they are switched to a high-conductance state. High-conductance states can substantially alter response properties of motoneurons....... In the present study we investigated how an increase in membrane conductance affects spike frequency adaptation, the gain (i.e., the slope of the frequency-current relationship) and the threshold for action potential generation. We used intracellular recordings from adult turtle motoneurons in spinal cord slices....... Membrane conductance was increased pharmacologically by extracellular application of the GABAA receptor agonist muscimol. Our findings suggest that an increase in membrane conductance of about 40–50% increases the magnitude of spike frequency adaptation, but does not change the threshold for action...

  5. Responsible conduct by life scientists in an age of terrorism.

    Science.gov (United States)

    Atlas, Ronald M

    2009-09-01

    The potential for dual use of research in the life sciences to be misused for harm raises a range of problems for the scientific community and policy makers. Various legal and ethical strategies are being implemented to reduce the threat of the misuse of research and knowledge in the life sciences by establishing a culture of responsible conduct.

  6. Embedding responsible conduct in learning and research into an Australian undergraduate curriculum.

    Science.gov (United States)

    Fernandes, Lynette B

    2017-01-02

    Responsible conduct in learning and research (RCLR) was progressively introduced into the pharmacology curriculum for undergraduate science students at The University of Western Australia. In the second year of this undergraduate curriculum, a lecture introduces students to issues such as the use of animals in teaching and responsible conduct of research. Third year student groups deliver presentations on topics including scientific integrity and the use of human subjects in research. Academic and research staff attending these presentations provide feedback and participate in discussions. Students enrolled in an optional capstone Honours year complete an online course on the responsible conduct of research and participate in an interactive movie. Once RCLR became established in the curriculum, a survey of Likert-scaled and open-ended questions examined student and staff perceptions. Data were expressed as Approval (% of responses represented by Strongly Agree and Agree). RCLR was found to be relevant to the study of pharmacology (69-100% Approval), important for one's future career (62-100% Approval), and stimulated further interest in this area (32-75% Approval). Free entry comments demonstrated the value of RCLR and constructive suggestions for improvement have now been incorporated. RCLR modules were found to be a valuable addition to the pharmacology undergraduate curriculum. This approach may be used to incorporate ethics into any science undergraduate curriculum, with the use of discipline-specific topics. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(1):53-59, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

  7. [An Investigation of the Role Responsibilities of Clinical Research Nurses in Conducting Clinical Trials].

    Science.gov (United States)

    Kao, Chi-Yin; Huang, Guey-Shiun; Dai, Yu-Tzu; Pai, Ya-Ying; Hu, Wen-Yu

    2015-06-01

    Clinical research nurses (CRNs) play an important role in improving the quality of clinical trials. In Taiwan, the increasing number of clinical trials has increased the number of practicing CRNs. Understanding the role responsibilities of CRNs is necessary to promote professionalism in this nursing category. This study investigates the role responsibilities of CRNs in conducting clinical trials / research. A questionnaire survey was conducted in a medical center in Taipei City, Taiwan. Eighty CRNs that were registered to facilitate and conduct clinical trials at this research site completed the survey. "Subject protection" was the CRN role responsibility most recognized by participants, followed by "research coordination and management", "subject clinical care", and "advanced professional nursing". Higher recognition scores were associated with higher importance scores and lower difficulty scores. Participants with trial training had significantly higher difficulty scores for "subject clinical care" and "research coordination and management" than their peers without this training (p research coordination and management" (p clinical practice.

  8. Burden of vasomotor symptoms in France, Germany, Italy, Spain, and the United Kingdom.

    Science.gov (United States)

    Dibonaventura, Marco Dacosta; Chandran, Arthi; Hsu, Ming-Ann; Bushmakin, Andrew

    2013-01-01

    Several studies have documented a significant association between vasomotor symptoms (VMS) and a decrement in health outcomes among postmenopausal women, but these studies have mostly focused on the US. The aim of the current study was to broaden this investigation by examining the burden of VMS symptoms in the European Union with respect to both humanistic and economic outcomes. All women aged 40-75 years who completed the 2010 5EU (France, Germany, Italy, Spain, and the UK) National Health and Wellness Survey were identified as potential respondents and invited to participate in an additional cross-sectional, Internet-based survey. Only postmenopausal women from 5EU were included in the current analyses (n = 3801). VMS was assessed using the Menopausal Rating Scale, and was used in multiple regression models as the primary predictor of health status (EQ-5D-3L), work productivity loss, and the number of physician visits due to menopause. Over half (50.3%) of postmenopausal women experienced either mild (24.6%), moderate (17.6%), or severe (8.1%) VMS. Controlling for confounding variables, mild (b = -0.03, P < 0.05), moderate (b = -0.07, P < 0.05), and severe VMS (b = -0.17, P < 0.05) were each associated with worse health utilities relative to women without VMS. Similarly, increased resource use (b = 1.04-2.39, all P < 0.05), overall work impairment (b = 8.71-19.69, all P < 0.05), and activity impairment (b = 11.22-24.54, all P < 0.05) were also observed as VMS severity increased (with each b representing the difference between each level of severity and the reference category). These results suggest a high prevalence of VMS in Western Europe. These symptoms are also associated with both humanistic and economic outcomes. Improved management of VMS may be able to increase the health status and ability to work productively as well as reduce societal direct costs.

  9. Numerical simulation on the thermal response of heat-conducting asphalt pavements

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hong; Wu Shaopeng; Chen Mingyu; Zhang Yuan, E-mail: wusp@whut.edu.c [Key Laboratory of Silicate Materials Science and Engineering, Ministry of Education, Wuhan University of Technology, Wuhan 430070 (China)

    2010-05-01

    Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

  10. Numerical simulation on the thermal response of heat-conducting asphalt pavements

    International Nuclear Information System (INIS)

    Wang Hong; Wu Shaopeng; Chen Mingyu; Zhang Yuan

    2010-01-01

    Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

  11. Cutaneous microvascular perfusion responses to insulin iontophoresis are differentially affected by insulin resistance after spinal cord injury.

    Science.gov (United States)

    La Fountaine, Michael F; Cirnigliaro, Christopher M; Azarelo, Frank; Hobson, Joshua C; Tascione, Oriana; Swonger, Kirsten N; Dyson-Hudson, Trevor; Bauman, William A

    2017-09-01

    What is the central question of this study? What impact does insulin resistance have on cutaneous perfusion responses to insulin iontophoresis in vascular beds with markedly reduced or functionally ablated sympathetic nervous system vasomotor function resulting from spinal cord injury? What is the main finding and its importance? Persons with spinal cord injury have sublesional microvascular endothelial dysfunction, as indicated by a blunted cutaneous perfusion response to acetylcholine iontophoresis, and the presence of insulin resistance has a further confounding effect on endothelium-mediated changes to cutaneous perfusion in the lower extremities. Endothelium-mediated mechanisms that regulate skin blood flow might play an integral role in optimizing skin perfusion in vascular beds with sympathetic nervous system vasomotor impairment, such as in spinal cord injury (SCI). Insulin is a vasoactive hormone and second messenger of nitric oxide that facilitates endothelium-mediated dilatation. The effects of insulin resistance (IR) on sublesional cutaneous perfusion responses to insulin provocation have yet to be described in persons with SCI. Persons with SCI and an able-bodied (AB) cohort were divided into subgroups based upon fasting plasma insulin concentration cut-offs for IR (≥13.13 mIU ml -1 ) or insulin sensitivity (IS; insulin, acetylcholine or placebo iontophoresis in the lower extremities; BPU responses were log 10 transformed to facilitate comparisons, and the net insulin response (NetIns) BPU response was calculated (insulin minus placebo BPU response). The NetIns was significantly greater in both IS groups compared with their corresponding IR group. The acetylcholine-mediated BPU responses in the SCI subgroups were significantly lower than those in the ABIS group. The proportional BPU responses of NetIns to acetylcholine in the IS cohorts (i.e. ABIS and SCIS) were significantly greater (P < 0.05) than that of each IR subgroup. The presence of IR

  12. Creating a Three-Parent Child: An Educational Paradigm for the Responsible Conduct of Research

    Directory of Open Access Journals (Sweden)

    Ruth L. Fischbach

    2014-10-01

    Full Text Available The field of assisted reproduction is renowned for its remarkable advances and constant pushing forward of research boundaries in an effort to offer innovative and effective methods for enhancing fertility. Accompanying these advances, however, are physiological, psychological, and bioethical consequences that must be considered. These concomitant advances and consequences make assisted reproduction an excellent educational paradigm for inculcating responsible conduct in both research and clinical practice. Ultimately, responsible conduct rests on the ethical researcher and clinician. Here, we present the as-yet unapproved, contentious assisted reproductive technology of mitochondrial replacement transfer (MRT as an ideal educational platform to foster the responsible conduct of research by advancing dialogue among multidisciplinary scholars, researchers, and students. Using a likely future case, we present the basic science, legal, and ethical considerations, and the pedagogical principles and strategies for using MRT as an effective educational paradigm. Society will benefit when the ethical issues inherent in creating children with three genetic parents as well as germline interference are discussed across multiple academic levels that include researchers, legal experts, bioethicists, and government-appointed commissions. Furthermore, undergraduate and graduate students should be included because they will likely determine the ethical fates of these biotechnologies. While emerging assisted reproduction technologies such as MRT are highly complex and will take years to be readily available for patients in need, now is the time to consider their scientific, legal, ethical, and cultural/religious implications for ensuring the responsible conduct of research.

  13. Cotton Fabric Coated with Conducting Polymers and its Application in Monitoring of Carnivorous Plant Response

    Directory of Open Access Journals (Sweden)

    Václav Bajgar

    2016-04-01

    Full Text Available The paper describes the electrical plant response to mechanical stimulation monitored with the help of conducting polymers deposited on cotton fabric. Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers in aqueous medium. Thus, modified fabrics were again coated with polypyrrole or polyaniline, respectively, in order to investigate any synergetic effect between both polymers with respect to conductivity and its stability during repeated dry cleaning. The coating was confirmed by infrared spectroscopy. The resulting fabrics have been used as electrodes to collect the electrical response to the stimulation of a Venus flytrap plant. This is a paradigm of the use of conducting polymers in monitoring of plant neurobiology.

  14. Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

    Directory of Open Access Journals (Sweden)

    Jefferson Luiz de Aguiar Paes

    2014-10-01

    Full Text Available Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

  15. Complex conductivity response to silver nanoparticles in partially saturated sand columns

    Science.gov (United States)

    Abdel Aal, Gamal; Atekwana, Estella A.; Werkema, D. Dale

    2017-02-01

    The increase in the use of nanoscale materials in consumer products has resulted in a growing concern of their potential hazard to ecosystems and public health from their accidental or intentional introduction to the environment. Key environmental, health, and safety research needs include knowledge and methods for their detection, characterization, fate, and transport. Specifically, techniques available for the direct detection and quantification of their fate and transport in the environment are limited. Their small size, high surface area to volume ratio, interfacial, and electrical properties make metallic nanoparticles, such as silver nanoparticles, good targets for detection using electrical geophysical techniques. Here we measured the complex conductivity response to silver nanoparticles in sand columns under varying moisture conditions (0-30%), nanoparticle concentrations (0-10 mg/g), lithology (presence of clay), pore water salinity (0.0275 and 0.1000 S/m), and particle size (35, 90-210 and 1500-2500 nm). Based on the Cole-Cole relaxation models we obtained the chargeability and the time constant. We demonstrate that complex conductivity can detect silver nanoparticles in porous media with the response enhanced by higher concentrations of silver nanoparticles, moisture content, ionic strength, clay content and particle diameter. Quantification of the volumetric silver nanoparticles content in the porous media can also be obtained from complex conductivity parameters based on the strong power law relationships.

  16. Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions

    International Nuclear Information System (INIS)

    Vora, Heli; Nielsen, Bent; Du, Xu

    2014-01-01

    Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO 2 substrates, we confirm recent theoretical predictions of T 2 temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures

  17. Characteristics of Nonallergic Vasomotor Rhinitis

    OpenAIRE

    Bernstein, Jonathan A

    2009-01-01

    Nonallergic rhinitis (NAR) conditions are currently considered diagnoses by exclusion. A diagnosis of NAR requires negative specific IgE responses by skin or serologic testing and more recently testing to exclude localized production of specific IgE in the nose. Symptoms are classically aggravated by irritant triggers such as tobacco smoke, perfumes/fragrances, and temperature or barometric pressure changes. A previously developed questionnaire survey designed to help physicians recognize dif...

  18. Mesocosm Community Response Sensitivities to Specific Conductivity Comprised of Different Major Ions

    Science.gov (United States)

    Traditional toxicity test assays have been used to evaluate the relative sensitivity to different major ion mixtures as a proxy for understanding what the response of aquatic species growing in their natural environment would be during exposure to specific conductivity stress ema...

  19. DESCRIPTION OF BRAINSTEM AUDITORY EVOKED RESPONSES (AIR AND BONE CONDUCTION IN CHILDREN WITH NORMAL HEARING

    Directory of Open Access Journals (Sweden)

    A. V. Pashkov

    2014-01-01

    Full Text Available Diagnosis of hearing level in small children with conductive hearing loss associated with congenital craniofacial abnormalities, particularly with agenesis of external ear and external auditory meatus is a pressing issue. Conventional methods of assessing hearing in the first years of life, i. e. registration of brainstem auditory evoked responses to acoustic stimuli in the event of air conduction, does not give an indication of the auditory analyzer’s condition due to potential conductive hearing loss in these patients. This study was aimed at assessing potential of diagnosing the auditory analyzer’s function with registering brainstem auditory evoked responses (BAERs to acoustic stimuli transmitted by means of a bone vibrator. The study involved 17 children aged 3–10 years with normal hearing. We compared parameters of registering brainstem auditory evoked responses (peak V depending on the type of stimulus transmission (air/bone in children with normal hearing. The data on thresholds of the BAERs registered to acoustic stimuli in the event of air and bone conduction obtained in this study are comparable; hearing thresholds in the event of acoustic stimulation by means of a bone vibrator correlates with the results of the BAERs registered to the stimuli transmitted by means of air conduction earphones (r = 0.9. High correlation of thresholds of BAERs to the stimuli transmitted by means of a bone vibrator with thresholds of BAERs registered when air conduction earphones were used helps to assess auditory analyzer’s condition in patients with any form of conductive hearing loss.  

  20. Chagas disease. A new pathophysiological assessment

    International Nuclear Information System (INIS)

    Redruello, M.; Masoli, O.; Hasson, I.; Cragnolino, D.; Traverso, S.; Perez Balino, N.; Sarmiento, R.; Lazzari, J.; Luluaga, E.

    2002-01-01

    Background: There is scarce information on myocardial perfusion abnormalities and on the coronary vasomotor condition in Chagas disease patients. Aims: To assess regional perfusion abnormalities and the coronary vasomotor response of patients in the chronic phase of Chagas disease. Methods: With the use of 99mTc-sestamibi SPECT imaging and cold pressor test and intracoronary acetylcoline (ACH) perfusion, we studied 9 patients aged 42,6±12 years, 4 males, in the chronic stage of Chagas disease (5 with the indeterminate form and 4 with heart lesion) with normal coronary arteries. Vasomotor responses to intracoronary increasing doses of ACH and to a single dose of nitroglycerine (NTG) were assessed with digital quantitative angiography. Regional myocardial perfusion was evaluated at rest and after cold pressor test by a semi quantitative score analysis in an 18-segment model with 99mTc-sestamibi SPECT images. Results were expressed as mean ± 2SD. Differences between continuous variables were measured by two tails Student's t test for paired variables and the significance level was set at 5 %. Results: All patients had regional perfusion defects and abnormal vasomotor response. The diameter of the left anterior descending artery decreased 34% from a basal diameter of 3.66∫0.95 mm down to 2.42±0.74 mm after maximal response to ACH (p<0.002). NTG infusion augmented its diameter to 3.86±0.77 mm (p<0.0002) that is a 60% increase from post ACH diameter. Myocardial perfusion score was 1∫2.66 at rest and 6.22±3.6 after cold pressor test (p<0.0001). Conclusions: This group of patients in the chronic phase of Chagas disease showed an abnormal vasoconstrictive response to intracoronary ACH and cold-induced perfusion defects suggesting that endothelial dysfunction plays a role in the pathophysiology of chronic Chagas heart disease

  1. A New Method for a Virtue-Based Responsible Conduct of Research Curriculum: Pilot Test Results.

    Science.gov (United States)

    Berling, Eric; McLeskey, Chet; O'Rourke, Michael; Pennock, Robert T

    2018-02-03

    Drawing on Pennock's theory of scientific virtues, we are developing an alternative curriculum for training scientists in the responsible conduct of research (RCR) that emphasizes internal values rather than externally imposed rules. This approach focuses on the virtuous characteristics of scientists that lead to responsible and exemplary behavior. We have been pilot-testing one element of such a virtue-based approach to RCR training by conducting dialogue sessions, modeled upon the approach developed by Toolbox Dialogue Initiative, that focus on a specific virtue, e.g., curiosity and objectivity. During these structured discussions, small groups of scientists explore the roles they think the focus virtue plays and should play in the practice of science. Preliminary results have shown that participants strongly prefer this virtue-based model over traditional methods of RCR training. While we cannot yet definitively say that participation in these RCR sessions contributes to responsible conduct, these pilot results are encouraging and warrant continued development of this virtue-based approach to RCR training.

  2. Electrical conductivity and piezoresistive response of 3D printed thermoplastic polyurethane/multiwalled carbon nanotube composites

    Science.gov (United States)

    Hohimer, Cameron J.; Petrossian, Gayaneh; Ameli, Amir; Mo, Changki; Pötschke, Petra

    2018-03-01

    Additive manufacturing (AM) is an emerging field experiencing rapid growth. This paper presents a feasibility study of using fused-deposition modeling (FDM) techniques with smart materials to fabricate objects with sensing and actuating capabilities. The fabrication of objects with sensing typically requires the integration and assembly of multiple components. Incorporating sensing elements into a single FDM process has the potential to significantly simplify manufacturing. The integration of multiple materials, especially smart materials and those with multi-functional properties, into the FDM process is challenging and still requires further development. Previous works by the authors have demonstrated a good printability of thermoplastic polyurethane/multiwall carbon nanotubes (TPU/MWCNT) while maintaining conductivity and piezoresistive response. This research explores the effects of layer height, nozzle temperature, and bed temperature on the electrical conductivity and piezoresistive response of printed TPU/MWCNT nanocomposites. An impedance analyzer was used to determine the conductivity of printed samples under different printing conditions from 5Hz-13MHz. The samples were then tested under compression loads to measure the piezoresistive response. Results show the conductivity and piezoresistive response are only slightly affected by the print parameters and they can be largely considered independent of the print conditions within the examined ranges of print parameters. This behavior simplifies the printing process design for TPU/MWCNT complex structures. This work demonstrates the possibility of manufacturing embedded and multidirectional flexible strain sensors using an inexpensive and versatile method, with potential applications in soft robotics, flexible electronics, and health monitoring.

  3. Identification of Scattering Mechanisms from Measured Impulse Response Signatures of Several Conducting Objects.

    Science.gov (United States)

    1984-02-01

    conducting sphere 35 compared to inverse transform of exact solution. 4-5. Measured impulse response of a conducting 2:1 right 37 circular cylinder with...frequency domain. This is equivalent to multiplication in the time domain by the inverse transform of w(n), which is shown in Figure 3-1 for N=15. The...equivalent pulse width from 0.066 T for the rectangular window to 0.10 T for the Hanning window. The inverse transform of the Hanning window is shown

  4. Pyroelectric response of perovskite heterostructures incorporating conductive oxide electrodes

    Science.gov (United States)

    Tipton, Charles Wesley, IV

    2000-10-01

    The use of imaging technologies has become pervasive in many applications as the demand for situational awareness information has increased over the last decade. No better example of the integration of these technologies can be found than that of infrared or thermal imaging. This dissertation, in the field of thermal imaging, has been motivated by the desire to advance the technology of uncooled, thin-film pyroelectric sensors and focuses on the materials and structures from which the detector elements will be built. This work provides a detailed study of the pyroelectric response of the La-Sr-Co-O/Pb-La-Zr-Ti-O/La-Sr-Co-O (LPL) structure. The LPL structure was chosen based on the needs of thin film detectors, the unique properties of the conductive oxide La-Sr-Co-O (LSCO), and the broad applicability of the Pb-La-Zr-Ti-O (PLZT) material system. Epitaxial heterostructures were grown by pulsed laser deposition on single-crystal oxide substrates. Using the oxygen pressure during cooling and heating of the LSCO layer as a key variable, we have been able to produce structures that have a pronounced internal field in the as-grown state. In these capacitors, where the bottom electrode has a large concentration of oxygen vacancies, we have discovered very large pyroelectric responses that are 10 to 30 times larger than expected of PLZT-based pyroelectric materials (typical values are 20 to 40 nCcm-2K -1). The enhanced pyroelectric responses are very repeatable, stable over time, and distinctly different from responses attributed to thermally stimulated currents. Detailed positron annihilation spectroscopy measurements reveal that there is indeed an oxygen concentration gradient across the capacitor. Based on the results of this study, I will present an analysis of the enhanced pyroelectric response. Although the enhanced response has been correlated with high concentrations of oxygen vacancies in the PLZT film and LSCO electrodes, the mechanism by which the large

  5. Vitamin C deficiency reduces muscarinic receptor coronary artery vasoconstriction and plasma tetrahydrobiopterin concentration in guinea pigs

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie

    2017-01-01

    Vitamin C (vitC) deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries...... exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32) were randomized to high (1500 mg/kg diet) or low (0 to 50 mg/kg diet) vitC for 10-12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium......-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid...

  6. Auditory Brainstem Responses to Bone-Conducted Brief Tones in Young Children with Conductive or Sensorineural Hearing Loss

    Directory of Open Access Journals (Sweden)

    Jennifer L. Hatton

    2012-01-01

    Full Text Available The bone-conduction (BC tone ABR has been used clinically for over 20 years. The current study formally evaluated the test performance of the BC tone-evoked ABR in infants with hearing loss. Method. By comparing BC-ABR results to follow-up behavioural results, this study addressed two questions: (i whether the BC tone ABR was successful in differentiating children with conductive versus sensorineural hearing loss (Study A; conductive: 68 ears; SNHL: 129 ears and (ii the relationship between BC ABR and behavioural hearing loss severity (Study B: 2000 Hz: 104 ears; 500 Hz: 47 ears. Results. Results demonstrate that the “normal” BC-ABR levels accurately differentiated normal versus elevated cochlear sensitivity (accuracy: 98% for 2000 Hz; 98% for 500 Hz. A subset of infants in Study A with elevated BC-ABR (i.e., no response at normal level had additional testing at higher intensities, which allowed for categorization of the degree of cochlear impairment. Study B results indicate that the BC ABR accurately categorizes the degree of cochlear hearing loss for 2000 Hz (accuracy = 95.2%. A preliminary dBnHL-to-dBHL correction factor of “0 dB” was determined for 2000 Hz BC ABR. Conclusions. These findings further support the use of BC tone ABR for diagnostic ABR testing.

  7. Auditory Brainstem Responses to Bone-Conducted Brief Tones in Young Children with Conductive or Sensorineural Hearing Loss

    Science.gov (United States)

    Hatton, Jennifer L.; Janssen, Renée M.; Stapells, David R.

    2012-01-01

    The bone-conduction (BC) tone ABR has been used clinically for over 20 years. The current study formally evaluated the test performance of the BC tone-evoked ABR in infants with hearing loss. Method. By comparing BC-ABR results to follow-up behavioural results, this study addressed two questions: (i) whether the BC tone ABR was successful in differentiating children with conductive versus sensorineural hearing loss (Study A; conductive: 68 ears; SNHL: 129 ears) and (ii) the relationship between BC ABR and behavioural hearing loss severity (Study B: 2000 Hz: 104 ears; 500 Hz: 47 ears). Results. Results demonstrate that the “normal” BC-ABR levels accurately differentiated normal versus elevated cochlear sensitivity (accuracy: 98% for 2000 Hz; 98% for 500 Hz). A subset of infants in Study A with elevated BC-ABR (i.e., no response at normal level) had additional testing at higher intensities, which allowed for categorization of the degree of cochlear impairment. Study B results indicate that the BC ABR accurately categorizes the degree of cochlear hearing loss for 2000 Hz (accuracy = 95.2%). A preliminary dBnHL-to-dBHL correction factor of “0 dB” was determined for 2000 Hz BC ABR. Conclusions. These findings further support the use of BC tone ABR for diagnostic ABR testing. PMID:22988461

  8. The role of sleep difficulties in the vasomotor menopausal symptoms and depressed mood relationships: an international pooled analysis of eight studies in the InterLACE consortium.

    Science.gov (United States)

    Chung, Hsin-Fang; Pandeya, Nirmala; Dobson, Annette J; Kuh, Diana; Brunner, Eric J; Crawford, Sybil L; Avis, Nancy E; Gold, Ellen B; Mitchell, Ellen S; Woods, Nancy F; Bromberger, Joyce T; Thurston, Rebecca C; Joffe, Hadine; Yoshizawa, Toyoko; Anderson, Debra; Mishra, Gita D

    2018-02-12

    Many women experience both vasomotor menopausal symptoms (VMS) and depressed mood at midlife, but little is known regarding the prospective bi-directional relationships between VMS and depressed mood and the role of sleep difficulties in both directions. A pooled analysis was conducted using data from 21 312 women (median: 50 years, interquartile range 49-51) in eight studies from the InterLACE consortium. The degree of VMS, sleep difficulties, and depressed mood was self-reported and categorised as never, rarely, sometimes, and often (if reporting frequency) or never, mild, moderate, and severe (if reporting severity). Multivariable logistic regression models were used to examine the bi-directional associations adjusted for within-study correlation. At baseline, the prevalence of VMS (40%, range 13-62%) and depressed mood (26%, 8-41%) varied substantially across studies, and a strong dose-dependent association between VMS and likelihood of depressed mood was found. Over 3 years of follow-up, women with often/severe VMS at baseline were more likely to have subsequent depressed mood compared with those without VMS (odds ratios (OR) 1.56, 1.27-1.92). Women with often/severe depressed mood at baseline were also more likely to have subsequent VMS than those without depressed mood (OR 1.89, 1.47-2.44). With further adjustment for the degree of sleep difficulties at baseline, the OR of having a subsequent depressed mood associated with often/severe VMS was attenuated and no longer significant (OR 1.13, 0.90-1.40). Conversely, often/severe depressed mood remained significantly associated with subsequent VMS (OR 1.80, 1.38-2.34). Difficulty in sleeping largely explained the relationship between VMS and subsequent depressed mood, but it had little impact on the relationship between depressed mood and subsequent VMS.

  9. Using Pneumatics to Perform Laboratory Hydraulic Conductivity Tests on Gravel with Underdamped Responses

    Science.gov (United States)

    Judge, A. I.

    2011-12-01

    A permeameter has been designed and built to perform laboratory hydraulic conductivity tests on various kinds of gravel samples with hydraulic conductivity values ranging from 0.1 to 1 m/s. The tests are commenced by applying 200 Pa of pneumatic pressure to the free surface of the water column in a riser connected above a cylinder that holds large gravel specimens. This setup forms a permeameter specially designed for these tests which is placed in a barrel filled with water, which acts as a reservoir. The applied pressure depresses the free surface in the riser 2 cm until it is instantly released by opening a ball valve. The water then flows through the base of the cylinder and the specimen like a falling head test, but the water level oscillates about the static value. The water pressure and the applied air pressure in the riser are measured with vented pressure transducers at 100 Hz. The change in diameter lowers the damping frequency of the fluctuations of the water level in the riser, which allows for underdamped responses to be observed for all tests. The results of tests without this diameter change would otherwise be a series of critically damped responses with only one or two oscillations that dampen within seconds and cannot be evaluated with equations for the falling head test. The underdamped responses oscillate about the static value at about 1 Hz and are very sensitive to the hydraulic conductivity of all the soils tested. These fluctuations are also very sensitive to the inertia and friction in the permeameter that are calculated considering the geometry of the permeameter and verified experimentally. Several gravel specimens of various shapes and sizes are tested that show distinct differences in water level fluctuations. The friction of the system is determined by calibrating the model with the results of tests performed where the cylinder had no soil in it. The calculation of the inertia in the response of the water column for the typical testing

  10. A DESIGN FRAMEWORK FOR HUMAN EMOTION RECOGNITION USING ELECTROCARDIOGRAM AND SKIN CONDUCTANCE RESPONSE SIGNALS

    Directory of Open Access Journals (Sweden)

    KHAIRUN NISA’ MINHAD

    2017-11-01

    Full Text Available Identification of human emotional state while driving a vehicle can help in understanding the human behaviour. Based on this identification, a response system can be developed in order to mitigate the impact that may be resulted from the behavioural changes. However, the adaptation of emotions to the environment at most scenarios is subjective to an individual’s perspective. Many factors, mainly cultural and geography, gender, age, life style and history, level of education and professional status, can affect the detection of human emotional affective states. This work investigated sympathetic responses toward human emotions defined by using electrocardiography (ECG and skin conductance response (SCR signals recorded simultaneously. This work aimed to recognize ECG and SCR patterns of the investigated emotions measured using selected sensor. A pilot study was conducted to evaluate the proposed framework. Initial results demonstrated the importance of suitability of the stimuli used to evoke the emotions and high opportunity for the ECG and SCR signals to be used in the automotive real-time emotion recognition systems.

  11. 5 CFR 2606.106 - OGE employee Privacy Act rules of conduct and responsibilities.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false OGE employee Privacy Act rules of conduct and responsibilities. 2606.106 Section 2606.106 Administrative Personnel OFFICE OF GOVERNMENT ETHICS... requirement to inform each individual asked to supply information to be maintained in a system of records the...

  12. SAVANNAH RIVER SITE CAPABILITIES FOR CONDUCTING INGESTION PATHWAY CONSEQUENCE ASSESSMENTS FOR EMERGENCY RESPONSE

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, C

    2007-12-11

    Potential airborne releases of radioactivity from facilities operated for the U. S. Department of Energy at the Savannah River Site could pose significant consequences to the public through the ingestion pathway. The Savannah River National Laboratory has developed a suite of technologies needed to conduct assessments of ingestion dose during emergency response, enabling emergency manager at SRS to develop initial protective action recommendation for state agencies early in the response and to make informed decisions on activation of additional Federal assets that would be needed to support long-term monitoring and assessment activities.

  13. Predicting photosynthesis and transpiration responses to ozone: decoupling modeled photosynthesis and stomatal conductance

    Directory of Open Access Journals (Sweden)

    D. Lombardozzi

    2012-08-01

    Full Text Available Plants exchange greenhouse gases carbon dioxide and water with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environmental conditions, like exposure to high ozone (O3 concentrations, alter photosynthesis independent of stomatal conductance, so models that couple these processes cannot accurately predict both. The goals of this study were to test direct and indirect photosynthesis and stomatal conductance modifications based on O3 damage to tulip poplar (Liriodendron tulipifera in a coupled Farquhar/Ball-Berry model. The same modifications were then tested in the Community Land Model (CLM to determine the impacts on gross primary productivity (GPP and transpiration at a constant O3 concentration of 100 parts per billion (ppb. Modifying the Vcmax parameter and directly modifying stomatal conductance best predicts photosynthesis and stomatal conductance responses to chronic O3 over a range of environmental conditions. On a global scale, directly modifying conductance reduces the effect of O3 on both transpiration and GPP compared to indirectly modifying conductance, particularly in the tropics. The results of this study suggest that independently modifying stomatal conductance can improve the ability of models to predict hydrologic cycling, and therefore improve future climate predictions.

  14. The framing effect and skin conductance responses

    Directory of Open Access Journals (Sweden)

    Patrick eRing

    2015-08-01

    Full Text Available Individuals often rely on simple heuristics when they face complex choice situations under uncertainty. Traditionally, it has been proposed that cognitive processes are the main driver to evaluate different choice options and finally to reach a decision. Growing evidence, however, highlights a strong interrelation between judgment and decision-making (JDM on the one hand, and emotional processes on the other hand. This also seems to apply to judgmental heuristics, i.e. decision-processes that are typically considered to be fast and intuitive. In this study, participants are exposed to different probabilities of receiving an unpleasant electric shock. Information about electric shock probabilities is either positively or negatively framed. Integrated skin conductance responses (ISCRs while waiting for electric shock realization are used as an indicator for participants' emotional arousal. This measure is compared to objective probabilities. I find evidence for a relation between emotional body reactions measured by ISCRs and the framing effect. Under negative frames, participants show significantly higher ISCRs while waiting for an electric shock to be delivered than under positive frames. This result might contribute to a better understanding of the psychological processes underlying JDM. Further studies are necessary to reveal the causality underlying this finding, i.e. whether emotional processes influence JDM or vice versa.

  15. The framing effect and skin conductance responses.

    Science.gov (United States)

    Ring, Patrick

    2015-01-01

    Individuals often rely on simple heuristics when they face complex choice situations under uncertainty. Traditionally, it has been proposed that cognitive processes are the main driver to evaluate different choice options and to finally reach a decision. Growing evidence, however, highlights a strong interrelation between judgment and decision-making (JDM) on the one hand, and emotional processes on the other hand. This also seems to apply to judgmental heuristics, i.e., decision processes that are typically considered to be fast and intuitive. In this study, participants are exposed to different probabilities of receiving an unpleasant electric shock. Information about electric shock probabilities is either positively or negatively framed. Integrated skin conductance responses (ISCRs) while waiting for electric shock realization are used as an indicator for participants' emotional arousal. This measure is compared to objective probabilities. I find evidence for a relation between emotional body reactions measured by ISCRs and the framing effect. Under negative frames, participants show significantly higher ISCRs while waiting for an electric shock to be delivered than under positive frames. This result might contribute to a better understanding of the psychological processes underlying JDM. Further studies are necessary to reveal the causality underlying this finding, i.e., whether emotional processes influence JDM or vice versa.

  16. Effect of Phase Response Curve Skew on Synchronization with and without Conduction Delays

    Directory of Open Access Journals (Sweden)

    Carmen eCanavier

    2013-12-01

    Full Text Available A central problem in cortical processing including sensory binding and attentional gating is how neurons can synchronize their responses with zero or near-zero time lag. For a spontaneously firing neuron, an input from another neuron can delay or advance the next spike by different amounts depending upon the timing of the input relative to the previous spike. This information constitutes the phase response curve (PRC. We present a simple graphical method for determining the effect of PRC shape on synchronization tendencies and illustrate it using type 1 PRCs, which consist entirely of advances (delays in response to excitation (inhibition. We obtained the following generic solutions for type 1 PRCs, which include the pulse coupled leaky integrate and fire model. For pairs with mutual excitation, exact synchrony can be stable for strong coupling because of the stabilizing effect of the causal limit region of the PRC in which an input triggers a spike immediately upon arrival. However, synchrony is unstable for short delays, because delayed inputs arrive during a refractory period and cannot trigger an immediate spike. Right skew destabilizes antiphase and enables modes with time lags that grow as the conduction delay is increased. Therefore, right skew favors near-synchrony at short conduction delays and a gradual transition between synchrony and antiphase for pairs coupled by mutual excitation. For pairs with mutual inhibition, zero time lag synchrony is stable for conduction delays ranging from zero to a substantial fraction of the period for pairs. However, for right skew there is a preferred antiphase mode at short delays. In contrast to mutual excitation, left skew destabilizes antiphase for mutual inhibition so that synchrony dominates at short delays as well. These pairwise synchronization tendencies constrain the synchronization properties of neurons embedded in larger networks.

  17. Endothelium-dependent relaxant responses to selective 5-HT(1B/1D) receptor agonists in the isolated middle cerebral artery of the rat

    DEFF Research Database (Denmark)

    Hansen-Schwartz, Jacob; Løvland Hoel, Natalie; Nilsson, Elisabeth

    2003-01-01

    perfused. Luminally added 5- hydroxytryptamine (5-HT), sumatriptan and rizatriptan induced maximal dilatations of 22 +/- 4, 10 +/- 2 and 13 +/- 5%, respectively, compared to the resting diameter. The relaxant effect of sumatriptan was blocked by the 5- HT(1B/1D) receptor selective antagonist GR 55562 (10......The vasomotor effects of triptans in the middle cerebral artery (MCA) of rats were studied using the pressurised arteriography method and in vitro vessel baths. Using the arteriograph, MCAs from Sprague-Dawley rats were mounted on two glass micropipettes, pressurised to 85 mm Hg and luminally...... response to 5-HT and triptans. Using the vessel bath technique, MCA segments were mounted on two metal wires. The relaxant responses to sumatriptan could not be reproduced using this model; instead, weak contractile responses (6 +/- 3% of submaximal contractile capacity) were observed. The difference...

  18. Electromechanical Response of Conductive Porous Structure

    Directory of Open Access Journals (Sweden)

    Hye-Mi So

    2015-01-01

    Full Text Available Porous conductors with large surface-volume ratios have been applied to a variety of fields, including absorbents, flexible heaters, and electrodes for supercapacitors. In this study, we implemented sensitive pressure sensors using the mechanical and electrical characteristics of conductive porous structures manufactured by immersing sponges into a carbon nanotube solution and then measured the change in resistance. When pressure was applied to conductive sponges, carbon nanotubes were attached to each other and the resistance was reduced by up to 20%. The carbon nanotube sponges, which were soft and had superior elasticity, were quickly stabilized without any changes taking place in their shape, and they showed consistent change in resistance during experiments of repetitive pressure. The pressure devices based on conductive porous sponges were connected to single-walled carbon nanotube field effect transistors (SWCNT-FETs and changes in their characteristics were investigated according to external pressure.

  19. High-ampacity conductive polymer microfibers as fast response wearable heaters and electromechanical actuators

    KAUST Repository

    Zhou, Jian; Mulle, Matthieu; Zhang, Yaobin; Xu, Xuezhu; Li, Erqiang; Han, Fei; Thoroddsen, Sigurdur T; Lubineau, Gilles

    2016-01-01

    Conductive fibers with enhanced physical properties and functionalities are needed for a diversity of electronic devices. Here, we report very high performance in the thermal and mechanical response of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) microfibers when subjected to an electrical current. These fibers were made by combining the hot-drawing assisted wetspinning process with ethylene glycol doping/de-doping that can work at a current density as high as 1.8 × 104 A cm−2, which is comparable to that of carbon nanotube fibers. Their electrothermal response was investigated using optical sensors and verified to be as fast as 63 °C s−1 and is comparable with that of metallic heating elements (20–50 °C s−1). We investigated the electromechanical actuation resulted from the reversible sorption/desorption of moisture controlled by electro-induced heating. The results revealed an improvement of several orders of magnitudes compared to other linear conductive polymer-based actuators in air. Specifically, the fibers we designed here have a rapid stress generation rate (>40 MPa s−1) and a wide operating frequency range (up to 40 Hz). These fibers have several characteristics including fast response, low-driven voltage, good repeatability, long cycle life and high energy efficiency, favoring their use as heating elements on wearable textiles and as artificial muscles for robotics.

  20. High-ampacity conductive polymer microfibers as fast response wearable heaters and electromechanical actuators

    KAUST Repository

    Zhou, Jian

    2016-01-04

    Conductive fibers with enhanced physical properties and functionalities are needed for a diversity of electronic devices. Here, we report very high performance in the thermal and mechanical response of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) microfibers when subjected to an electrical current. These fibers were made by combining the hot-drawing assisted wetspinning process with ethylene glycol doping/de-doping that can work at a current density as high as 1.8 × 104 A cm−2, which is comparable to that of carbon nanotube fibers. Their electrothermal response was investigated using optical sensors and verified to be as fast as 63 °C s−1 and is comparable with that of metallic heating elements (20–50 °C s−1). We investigated the electromechanical actuation resulted from the reversible sorption/desorption of moisture controlled by electro-induced heating. The results revealed an improvement of several orders of magnitudes compared to other linear conductive polymer-based actuators in air. Specifically, the fibers we designed here have a rapid stress generation rate (>40 MPa s−1) and a wide operating frequency range (up to 40 Hz). These fibers have several characteristics including fast response, low-driven voltage, good repeatability, long cycle life and high energy efficiency, favoring their use as heating elements on wearable textiles and as artificial muscles for robotics.

  1. Physical Mechanisms Responsible for Electrical Conduction in Pt/GaN Schottky Diodes

    OpenAIRE

    H. MAZARI; K. AMEUR; N. BENSEDDIK; Z. BENAMARA; R. KHELIFI; M. MOSTEFAOUI; N. ZOUGAGH; N. BENYAHYA; R. BECHAREF; G. BASSOU; B. GRUZZA; J. M. BLUET; C. BRU-CHEVALLIER

    2014-01-01

    The current-voltage (I-V) characteristics of Pt/(n.u.d)-GaN and Pt/Si-doped-GaN diodes Schottky are investigated. Based on these measurements, physical mechanisms responsible for electrical conduction have been suggested. The contribution of thermionic-emission current and various other current transport mechanisms were assumed when evaluating the Schottky barrier height. Thus the generation-recombination, tunneling and leakage currents caused by inhomogeneities and defects at metal-semicondu...

  2. Framework for estimating response time data to conduct a seismic human reliability analysis - its feasibility

    International Nuclear Information System (INIS)

    Park, Jinkyun; Kin, Yochan; Jung, Wondea; Jang, Seung Cheol

    2014-01-01

    This is because the PSA has been used for several decades as the representative tool to evaluate the safety of NPPs. To this end, it is inevitable to evaluate human error probabilities (HEPs) in conducting important tasks being considered in the PSA framework (i.e., HFEs; human failure events), which are able to significantly affect the safety of NPPs. In addition, it should be emphasized that the provision of a realistic human performance data is an important precondition for calculating HEPs under a seismic condition. Unfortunately, it seems that HRA methods being currently used for calculating HEPs under a seismic event do not properly consider the performance variation of human operators. For this reason, in this paper, a framework to estimate response time data that are critical for calculating HEPs is suggested with respect to a seismic intensity. This paper suggested a systematic framework for estimating response time data that would be one of the most critical for calculating HEPs. Although extensive review of existing literatures is indispensable for identifying response times of human operators who have to conduct a series of tasks prescribed in procedures based on a couple of wrong indications, it is highly expected that response time data for seismic HRA can be properly secured through revisiting response time data collected from diverse situations without concerning a seismic event

  3. Aligning Objectives and Assessment in Responsible Conduct of Research Instruction

    Science.gov (United States)

    Antes, Alison L.; DuBois, James M.

    2014-01-01

    Efforts to advance research integrity in light of concerns about misbehavior in research rely heavily on education in the responsible conduct of research (RCR). However, there is limited evidence for the effectiveness of RCR instruction as a remedy. Assessment is essential in RCR education if the research community wishes to expend the effort of instructors, students, and trainees wisely. This article presents key considerations that instructors and course directors must consider in aligning learning objectives with instructional methods and assessment measures, and it provides illustrative examples. Above all, in order for RCR educators to assess outcomes more effectively, they must align assessment to their learning objectives and attend to the validity of the measures used. PMID:25574258

  4. Local electric stimulation causes conducted calcium response in rat interlobular arteries

    DEFF Research Database (Denmark)

    Salomonsson, Max; Gustafsson, Finn; Andreasen, Ditte

    2002-01-01

    microscope. Local electrical pulse stimulation (200 ms, 100 V) was administered by means of an NaCl-filled microelectrode (0.7-1 M(Omega)) juxtaposed to one end of the vessel. Intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured with an image system at a site approximately 500 microm from......The purpose of the present study was to investigate the conducted Ca(2+) response to local electrical stimulation in isolated rat interlobular arteries. Interlobular arteries were isolated from young Sprague-Dawley rats, loaded with fura 2, and attached to pipettes in a chamber on an inverted...

  5. Modeling the legal field of formation of socially responsible conduct among pharmacy specialists

    Directory of Open Access Journals (Sweden)

    N. O. Tkachenko

    2018-03-01

    Full Text Available Observation of legal and legislative standards of the company activities is the fundamental principle of social responsibility (SR. The results of the literature analysis show the lack of fundamental research of regulatory and legal support of formation of socially responsible conduct of pharmacists (SRCPh. AIM: modeling the legal framework and determining the completeness and content of the current regulatory and legal framework on formation of a system of SRCPh throughout the professional lifespan development. Materials and methods. The materials of the study were national and international regulatory legal acts, regulating SR, the activities of pharmaceutical organizations (PhO and getting a pharmaceutical education. During the work, such methods as searching information, systematization, content analysis, comparison and generalization were used. During the investigation, we summarized the legal framework that in various aspects forms the socially responsible conduct of the pharmacists throughout the lifespan professional development; and a model of the legal field of this process was formed. A content analysis of this regulatory framework in aspect of responsibility of the PhO and pharmacists with a description of the problem legal questions in the context of SR was carried out. In this article, attention is paid to the basic level of the legal field, within which general principles of social relations are formed in all spheres of the economy. Conclusions. We have formed a model of the legal field formation of a SRCPh system throughout the professional lifespan development. The model is a complex, multilevel system. The regulatory framework in the model is distributed according to two criteria (hierarchical and regulating relations in the system of socially responsible conduct of the pharmacists and includes 27 basic normative legal acts. We have identified problems in the legal field of the basic level of SRCPh formation: the indistinctness

  6. Validation of infrared thermography in serotonin-induced itch model in rats

    DEFF Research Database (Denmark)

    Dagnæs-Hansen, Frederik; Jasemian, Yousef; Gazerani, Parisa

    The number of scratching bouts is generally used as a standard method in animal models of itch. The aim of the present study was to validate the application of infrared thermography (IR-Th) in a serotonin-induced itch model in rats. Adult Sprague-Dawley male rats (n = 24) were used in 3 consecutive...... experiments. The first experiment evaluated vasomotor response (IR-Th) and scratching behavior (number of bouts) induced by intradermal serotonin (10 μl, 2%). Isotonic saline (control: 10 μl, 0.9%) and Methysergide (antagonist: 10 μl, 0.047 mg/ml) were used. The second experiment evaluated the dose......-response effect of intradermal serotonin (1%, 2% and 4%) on local temperature. The third experiment evaluated the anesthetized rats to test the local vasomotor responses in absent of scratching. Serotonin elicited significant scratching and lowered the local temperature at the site of injection. A dose...

  7. Physical Mechanisms Responsible for Electrical Conduction in Pt/GaN Schottky Diodes

    Directory of Open Access Journals (Sweden)

    H. MAZARI

    2014-05-01

    Full Text Available The current-voltage (I-V characteristics of Pt/(n.u.d-GaN and Pt/Si-doped-GaN diodes Schottky are investigated. Based on these measurements, physical mechanisms responsible for electrical conduction have been suggested. The contribution of thermionic-emission current and various other current transport mechanisms were assumed when evaluating the Schottky barrier height. Thus the generation-recombination, tunneling and leakage currents caused by inhomogeneities and defects at metal-semiconductor interface were taken into account.

  8. Integrating Responsible Conduct of Research Education into Undergraduate Biochemistry and Molecular Biology Laboratory Curricula

    Science.gov (United States)

    Hendrickson, Tamara L.

    2015-01-01

    Recently, a requirement for directed responsible conduct in research (RCR) education has become a priority in the United States and elsewhere. In the US, both the National Institutes of Health and the National Science Foundation require RCR education for all students who are financially supported by federal awards. The guidelines produced by these…

  9. Ac-conductivity and dielectric response of new zinc-phosphate glass/metal composites

    Energy Technology Data Exchange (ETDEWEB)

    Maaroufi, A., E-mail: maaroufi@fsr.ac.ma [University of Mohammed V, Laboratory of Composite Materials, Polymers and Environment, Department of Chemistry, Faculty of Sciences, P.B. 1014, Rabat-Agdal (Morocco); Oabi, O. [University of Mohammed V, Laboratory of Composite Materials, Polymers and Environment, Department of Chemistry, Faculty of Sciences, P.B. 1014, Rabat-Agdal (Morocco); Lucas, B. [XLIM UMR 7252 – Université de Limoges/CNRS, 123 avenue Albert Thomas, 87060 Limoges Cedex (France)

    2016-07-01

    The ac-conductivity and dielectric response of new composites based on zinc-phosphate glass with composition 45 mol%ZnO–55 mol%P{sub 2}O{sub 5}, filled with metallic powder of nickel (ZP/Ni) were investigated by impedance spectroscopy in the frequency range from 100 Hz to 1 MHz at room temperature. A high percolating jump of seven times has been observed in the conductivity behavior from low volume fraction of filler to the higher fractions, indicating an insulator – semiconductor phase transition. The measured conductivity at higher filler volume fraction is about 10{sup −1} S/cm and is frequency independent, while, the obtained conductivity for low filler volume fraction is around 10{sup −8} S/cm and is frequency dependent. Moreover, the elaborated composites are characterized by high dielectric constants in the range of 10{sup 5} for conductive composites at low frequencies (100 Hz). In addition, the distribution of the relaxation processes was also evaluated. The Debye, Cole-Cole, Davidson–Cole and Havriliak–Negami models in electric modulus formalism were used to model the observed relaxation phenomena in ZP/Ni composites. The observed relaxation phenomena are fairly simulated by Davidson–Cole model, and an account of the interpretation of results is given. - Highlights: • Composites of ZnO-P{sub 2}O{sub 5}/metal were investigated by impedance spectroscopy. • Original ac-conductivity behavior was discovered in ZnO-P{sub 2}O{sub 5}/metal composites. • High dielectric constant is measured in ZnO-P{sub 2}O{sub 5}/metal composites. • Dielectric constant as filler function is well interpreted with percolation theory. • Observed relaxation processes are well described using electric modulus formalism.

  10. Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

    DEFF Research Database (Denmark)

    Jensen, K; Andersen, K; Smith, T

    1984-01-01

    (18% and 48% decrease respectively). However, in three patients with moderate neuropathy, and in one patient with no signs of neuropathy, this veno-arteriolar reflex was absent, indicating dysfunction of the peripheral sympathetic adrenergic nerve fibres. The three patients also showed a lesser degree......The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a 50...... comprise not only the peripheral sensory and motor nerve fibres, but also the thin pseudomotor and vasomotor nerves....

  11. Membrane potential and response properties of populations of cortical neurons in the high conductance state

    International Nuclear Information System (INIS)

    Moreno-Bote, Ruben; Parga, Nestor

    2005-01-01

    Because of intense synaptic activity, cortical neurons are in a high conductance state. We show that this state has important consequences on the properties of a population of independent model neurons with conductance-based synapses. Using an adiabaticlike approximation we study both the membrane potential and the firing probability distributions across the population. We find that the latter is bimodal in such a way that at any particular moment some neurons are inactive while others are active. The population rate and the response variability are also characterized

  12. How the type of input function affects the dynamic response of conducting polymer actuators

    Science.gov (United States)

    Xiang, Xingcan; Alici, Gursel; Mutlu, Rahim; Li, Weihua

    2014-10-01

    There has been a growing interest in smart actuators typified by conducting polymer actuators, especially in their (i) fabrication, modeling and control with minimum external data and (ii) applications in bio-inspired devices, robotics and mechatronics. Their control is a challenging research problem due to the complex and nonlinear properties of these actuators, which cannot be predicted accurately. Based on an input-shaping technique, we propose a new method to improve the conducting polymer actuators’ command-following ability, while minimizing their electric power consumption. We applied four input functions with smooth characteristics to a trilayer conducting polymer actuator to experimentally evaluate its command-following ability under an open-loop control strategy and a simulated feedback control strategy, and, more importantly, to quantify how the type of input function affects the dynamic response of this class of actuators. We have found that the four smooth inputs consume less electrical power than sharp inputs such as a step input with discontinuous higher-order derivatives. We also obtained an improved transient response performance from the smooth inputs, especially under the simulated feedback control strategy, which we have proposed previously [X Xiang, R Mutlu, G Alici, and W Li, 2014 “Control of conducting polymer actuators without physical feedback: simulated feedback control approach with particle swarm optimization’, Journal of Smart Materials and Structure, 23]. The idea of using a smooth input command, which results in lower power consumption and better control performance, can be extended to other smart actuators. Consuming less electrical energy or power will have a direct effect on enhancing the operational life of these actuators.

  13. How the type of input function affects the dynamic response of conducting polymer actuators

    International Nuclear Information System (INIS)

    Xiang, Xingcan; Alici, Gursel; Mutlu, Rahim; Li, Weihua

    2014-01-01

    There has been a growing interest in smart actuators typified by conducting polymer actuators, especially in their (i) fabrication, modeling and control with minimum external data and (ii) applications in bio-inspired devices, robotics and mechatronics. Their control is a challenging research problem due to the complex and nonlinear properties of these actuators, which cannot be predicted accurately. Based on an input-shaping technique, we propose a new method to improve the conducting polymer actuators’ command-following ability, while minimizing their electric power consumption. We applied four input functions with smooth characteristics to a trilayer conducting polymer actuator to experimentally evaluate its command-following ability under an open-loop control strategy and a simulated feedback control strategy, and, more importantly, to quantify how the type of input function affects the dynamic response of this class of actuators. We have found that the four smooth inputs consume less electrical power than sharp inputs such as a step input with discontinuous higher-order derivatives. We also obtained an improved transient response performance from the smooth inputs, especially under the simulated feedback control strategy, which we have proposed previously [X Xiang, R Mutlu, G Alici, and W Li, 2014 “Control of conducting polymer actuators without physical feedback: simulated feedback control approach with particle swarm optimization’, Journal of Smart Materials and Structure, 23]. The idea of using a smooth input command, which results in lower power consumption and better control performance, can be extended to other smart actuators. Consuming less electrical energy or power will have a direct effect on enhancing the operational life of these actuators. (paper)

  14. 45 CFR 2508.8 - Who is responsible for establishing the Corporation's rules of conduct for Privacy Act compliance?

    Science.gov (United States)

    2010-10-01

    ... Corporation's rules of conduct for Privacy Act compliance? 2508.8 Section 2508.8 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE IMPLEMENTATION OF THE PRIVACY ACT OF 1974 § 2508.8 Who is responsible for establishing the Corporation's rules of conduct for...

  15. Gamma- and electron dose response of the electrical conductivity of polyaniline based polymer blends

    International Nuclear Information System (INIS)

    Sevil, U.A.; Gueven, O.; Slezsak, I.

    2002-01-01

    Complete text of publication follows. Conducting polymers, also known as 'synthetic metals' have been the subject of widespread investigations over the past decade due to their very promising characteristics. Polyaniline (PANI) holds a special position among conducting polymers in that its most highly conducting doped form can be reached by protonic acid doping or oxidative doping. It was published earlier, that the electrical conductivity of some polyaniline based polymer composites increases to a significant extent when irradiated to gamma, electron or UV radiation. The aim of the present study was to measure the high frequency conductivity of blended films of PANI with poly(vinylchloride), PVC, and chlorinated poly(propylene) irradiated in air to different doses. In order to find the most suitable composition od these composites the mass percentage of PANI within the PPCl and PVC matrix was changed between 5 - 30%. These samples were then gamma irradiated and the induced electrical conductivity was measured in the 1 kHz - 1 MHz frequency range to determine the most sensitive evaluation conditions. After selecting both the most suitable measuring conditions as well as the blend compositions the dose response of the chosen samples was determined in the dose range of 10 - 250 kGy. With respect to potential dosimetry application the effect of electron irradiation, the effect of irradiation temperature and the stability of the irradiated samples have also been investigated

  16. Characteristics of Nonallergic Vasomotor Rhinitis

    Science.gov (United States)

    2009-01-01

    Nonallergic rhinitis (NAR) conditions are currently considered diagnoses by exclusion. A diagnosis of NAR requires negative specific IgE responses by skin or serologic testing and more recently testing to exclude localized production of specific IgE in the nose. Symptoms are classically aggravated by irritant triggers such as tobacco smoke, perfumes/fragrances, and temperature or barometric pressure changes. A previously developed questionnaire survey designed to help physicians recognize differences between allergic rhinitis and nonallergic rhinitis subtypes found that patients with symptom onset later in life (> 35 years), no family history of allergies, no seasonality or cat-induced symptoms, and symptoms induced by perfumes and fragrances had > 95% likelihood of having a physician diagnosis of NAR. Of note, clinical symptoms were not generally useful for differentiating chronic rhinitis subtypes which has also been confirmed in a more recent study investigating the relationship between headaches and chronic rhinitis subtypes (Table 1). In subsequent studies it was found that a significant percentage of NAR patients did not experience irritant-induced symptoms, suggesting that these triggers are not a clinical characteristic that can be uniformly used for all NAR patients. However, a newly developed Irritant Index Scale can be used to reliably differentiate pure allergic rhinitis from nonallergic rhinitis with trigger phenotypes. The use of standardized and validated questionnaires allows objective characterization of chronic rhinitis subtypes that appears to improve the accuracy of clinically diagnosing these patients. PMID:24228982

  17. Nonhormonal management of menopause-associated vasomotor symptoms: 2015 position statement of The North American Menopause Society.

    Science.gov (United States)

    2015-11-01

    To update and expand The North American Menopause Society's evidence-based position on nonhormonal management of menopause-associated vasomotor symptoms (VMS), previously a portion of the position statement on the management of VMS. NAMS enlisted clinical and research experts in the field and a reference librarian to identify and review available evidence. Five different electronic search engines were used to cull relevant literature. Using the literature, experts created a document for final approval by the NAMS Board of Trustees. Nonhormonal management of VMS is an important consideration when hormone therapy is not an option, either because of medical contraindications or a woman's personal choice. Nonhormonal therapies include lifestyle changes, mind-body techniques, dietary management and supplements, prescription therapies, and others. The costs, time, and effort involved as well as adverse effects, lack of long-term studies, and potential interactions with medications all need to be carefully weighed against potential effectiveness during decision making. Clinicians need to be well informed about the level of evidence available for the wide array of nonhormonal management options currently available to midlife women to help prevent underuse of effective therapies or use of inappropriate or ineffective therapies. Recommended: Cognitive-behavioral therapy and, to a lesser extent, clinical hypnosis have been shown to be effective in reducing VMS. Paroxetine salt is the only nonhormonal medication approved by the US Food and Drug Administration for the management of VMS, although other selective serotonin reuptake/norepinephrine reuptake inhibitors, gabapentinoids, and clonidine show evidence of efficacy. Recommend with caution: Some therapies that may be beneficial for alleviating VMS are weight loss, mindfulness-based stress reduction, the S-equol derivatives of soy isoflavones, and stellate ganglion block, but additional studies of these therapies are

  18. 21 CFR 822.24 - What are my responsibilities once I am notified that I am required to conduct postmarket...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false What are my responsibilities once I am notified that I am required to conduct postmarket surveillance? 822.24 Section 822.24 Food and Drugs FOOD AND... SURVEILLANCE Responsibilities of Manufacturers § 822.24 What are my responsibilities once I am notified that I...

  19. Low frequency complex dielectric (conductivity) response of dilute clay suspensions: Modeling and experiments.

    Science.gov (United States)

    Hou, Chang-Yu; Feng, Ling; Seleznev, Nikita; Freed, Denise E

    2018-04-11

    In this work, we establish an effective medium model to describe the low-frequency complex dielectric (conductivity) dispersion of dilute clay suspensions. We use previously obtained low-frequency polarization coefficients for a charged oblate spheroidal particle immersed in an electrolyte as the building block for the Maxwell Garnett mixing formula to model the dilute clay suspension. The complex conductivity phase dispersion exhibits a near-resonance peak when the clay grains have a narrow size distribution. The peak frequency is associated with the size distribution as well as the shape of clay grains and is often referred to as the characteristic frequency. In contrast, if the size of the clay grains has a broad distribution, the phase peak is broadened and can disappear into the background of the canonical phase response of the brine. To benchmark our model, the low-frequency dispersion of the complex conductivity of dilute clay suspensions is measured using a four-point impedance measurement, which can be reliably calibrated in the frequency range between 0.1 Hz and 10 kHz. By using a minimal number of fitting parameters when reliable information is available as input for the model and carefully examining the issue of potential over-fitting, we found that our model can be used to fit the measured dispersion of the complex conductivity with reasonable parameters. The good match between the modeled and experimental complex conductivity dispersion allows us to argue that our simplified model captures the essential physics for describing the low-frequency dispersion of the complex conductivity of dilute clay suspensions. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Symptoms of endocrine treatment and outcome in the BIG 1-98 study.

    Science.gov (United States)

    Huober, J; Cole, B F; Rabaglio, M; Giobbie-Hurder, A; Wu, J; Ejlertsen, B; Bonnefoi, H; Forbes, J F; Neven, P; Láng, I; Smith, I; Wardley, A; Price, K N; Goldhirsch, A; Coates, A S; Colleoni, M; Gelber, R D; Thürlimann, B

    2014-01-01

    There may be a relationship between the incidence of vasomotor and arthralgia/myalgia symptoms and treatment outcomes for postmenopausal breast cancer patients with endocrine-responsive disease who received adjuvant letrozole or tamoxifen. Data on patients randomized into the monotherapy arms of the BIG 1-98 clinical trial who did not have either vasomotor or arthralgia/myalgia/carpal tunnel (AMC) symptoms reported at baseline, started protocol treatment and were alive and disease-free at the 3-month landmark (n = 4,798) and at the 12-month landmark (n = 4,682) were used for this report. Cohorts of patients with vasomotor symptoms, AMC symptoms, neither, or both were defined at both 3 and 12 months from randomization. Landmark analyses were performed for disease-free survival (DFS) and for breast cancer free interval (BCFI), using regression analysis to estimate hazard ratios (HR) and 95 % confidence intervals (CI). Median follow-up was 7.0 years. Reporting of AMC symptoms was associated with better outcome for both the 3- and 12-month landmark analyses [e.g., 12-month landmark, HR (95 % CI) for DFS = 0.65 (0.49-0.87), and for BCFI = 0.70 (0.49-0.99)]. By contrast, reporting of vasomotor symptoms was less clearly associated with DFS [12-month DFS HR (95 % CI) = 0.82 (0.70-0.96)] and BCFI (12-month DFS HR (95 % CI) = 0.97 (0.80-1.18). Interaction tests indicated no effect of treatment group on associations between symptoms and outcomes. While reporting of AMC symptoms was clearly associated with better DFS and BCFI, the association between vasomotor symptoms and outcome was less clear, especially with respect to breast cancer-related events.

  1. Electromechanical response of silk fibroin hydrogel and conductive polycarbazole/silk fibroin hydrogel composites as actuator material.

    Science.gov (United States)

    Srisawasdi, Thanida; Petcharoen, Karat; Sirivat, Anuvat; Jamieson, Alexander M

    2015-11-01

    Pure silk fibroin (SF) hydrogel and polycarbazole/silk fibroin (SF/PCZ) hydrogels were fabricated by solvent casting technique to evaluate electromechanical responses, dielectric properties, and cantilever deflection properties as functions of electric field strength, SF concentration, glutaraldehyde concentration, and PCZ concentration in the blends. Electromechanical properties were characterized in oscillatory shear mode at electric field strengths ranging from 0 to 600V/mm and at a temperature of 27°C. For both the pristine SF and SF/PCZ hydrogels, the storage modulus response (ΔG') and the storage modulus sensitivity (ΔG'/G'0) increased dramatically with increasing electric field strength. The pristine hydrogel possessed the highest storage modulus sensitivity value of 5.87, a relatively high value when compared with other previously studied electroactive polymers. With the addition of conductive PCZ in SF hydrogel, the storage modulus sensitivity and the relative dielectric constant decreased; the conductive polymer thus provided the softening effect under electric field. In the deflection response, the dielectrophoresis force and deflection distance increased monotonically with electric field strength, where the pure SF hydrogel showed the highest deflection distance and dielectrophoresis force. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Applicability of cable theory to vascular conducted responses.

    Science.gov (United States)

    Hald, Bjørn Olav; Jensen, Lars Jørn; Sørensen, Preben Graae; Holstein-Rathlou, Niels-Henrik; Jacobsen, Jens Christian Brings

    2012-03-21

    Conduction processes in the vasculature have traditionally been described using cable theory, i.e., locally induced signals decaying passively along the arteriolar wall. The decay is typically quantified using the steady-state length-constant, λ, derived from cable theory. However, the applicability of cable theory to blood vessels depends on assumptions that are not necessarily fulfilled in small arteries and arterioles. We have employed a morphologically and electrophysiologically detailed mathematical model of a rat mesenteric arteriole to investigate if the assumptions hold and whether λ adequately describes simulated conduction profiles. We find that several important cable theory assumptions are violated when applied to small blood vessels. However, the phenomenological use of a length-constant from a single exponential function is a good measure of conduction length. Hence, λ should be interpreted as a descriptive measure and not in light of cable theory. Determination of λ using cable theory assumes steady-state conditions. In contrast, using the model it is possible to probe how conduction behaves before steady state is achieved. As ion channels have time-dependent activation and inactivation, the conduction profile changes considerably during this dynamic period with an initially longer spread of current. This may have implications in relation to explaining why different agonists have different conduction properties. Also, it illustrates the necessity of using and developing models that handle the nonlinearity of ion channels. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Mechanical and vasomotor properties of piglet isolated middle cerebral artery

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R.; Abdolalizadeh, Bahareh; Trautner, Simon

    2017-01-01

    in newborns, is not characterized in piglets’ MCA. Finally, the influence of preterm birth on the dopamine response is not known. The aim of this current was to compare by wire myography the active and passive mechanical characteristics and dopamine concentration–response relations of MCAs isolated from......Piglets are often used as experimental models for studying cerebrovascular responses in newborn infants. However, the mechanical characteristics of piglets’ middle cerebral arteries (MCA) are not well characterized. Additionally, the vessels’ response to dopamine, the most commonly used vasopressor...... preterm and term newborn piglets. Second-order branches of the MCA with a diameter

  4. A comparative study between responses of isolated bovine and equine digital arteries to vasoactive mediators.

    Science.gov (United States)

    Zizzadoro, C; Caruso, M; Punzi, S; Crescenzo, G; Zongoli, F; Belloli, C

    2018-02-01

    Hemodynamic perturbations, partly resulting from abnormal vasoconstriction of digital vessels, have been implicated in the pathogenesis of bovine and equine laminitis. This study compared the responsiveness of isolated bovine (BDA) and equine (EDA) digital arteries to pharmacological agents that stimulate receptor systems involved in the regulation of normal vessel tone. The role of the endothelium and the short- and longer-term effects of an experimentally induced endothelial damage were also evaluated. Species-related differences were found in the vessel reactivity to all of the receptor agonists tested. In intact BDA, as compared to intact EDA, norepinephrine was a more effective vasoconstrictor, 5-hydroxytryptamine a more effective but less potent vasoconstrictor, isoproterenol a less effective vasodilator and carbamylcholine a less potent vasodilator. In BDA, but not in EDA, the contractile responses to norepinephrine and 5-hydroxytryptamine were enhanced immediately after endothelium removal. However, the contractile reactivity of denuded BDA returned to basal values following overnight incubation. The differences suggest species specificity for the pathophysiology of digital vasomotor tone and function in horses and cattle. © 2017 John Wiley & Sons Ltd.

  5. Boys with conduct problems and callous-unemotional traits: Neural response to reward and punishment and associations with treatment response

    Directory of Open Access Journals (Sweden)

    Amy L. Byrd

    2018-04-01

    Full Text Available Abnormalities in reward and punishment processing are implicated in the development of conduct problems (CP, particularly among youth with callous-unemotional (CU traits. However, no studies have examined whether CP children with high versus low CU traits exhibit differences in the neural response to reward and punishment. A clinic-referred sample of CP boys with high versus low CU traits (ages 8–11; n = 37 and healthy controls (HC; n = 27 completed a fMRI task assessing reward and punishment processing. CP boys also completed a randomized control trial examining the effectiveness of an empirically-supported intervention (i.e., Stop-Now-And-Plan; SNAP. Primary analyses examined pre-treatment differences in neural activation to reward and punishment, and exploratory analyses assessed whether these differences predicted treatment outcome. Results demonstrated associations between CP and reduced amygdala activation to punishment independent of age, race, IQ and co-occurring ADHD and internalizing symptoms. CU traits were not associated with reward or punishment processing after accounting for covariates and no differences were found between CP boys with high versus low CU traits. While boys assigned to SNAP showed a greater reduction in CP, differences in neural activation were not associated with treatment response. Findings suggest that reduced sensitivity to punishment is associated with early-onset CP in boys regardless of the level of CU traits. Keywords: Conduct problems, Callous-unemotional (CU traits, Reward, Punishment, fMRI

  6. Cracking the Code: Assessing Institutional Compliance with the Australian Code for the Responsible Conduct of Research

    Science.gov (United States)

    Morris, Suzanne E.

    2010-01-01

    This paper provides a review of institutional authorship policies as required by the "Australian Code for the Responsible Conduct of Research" (the "Code") (National Health and Medical Research Council (NHMRC), the Australian Research Council (ARC) & Universities Australia (UA) 2007), and assesses them for Code compliance.…

  7. Intermittent 96-Hour Auricular Electroacupuncture for Hot Flashes in Patients with Prostate Cancer: A Pilot Study.

    Science.gov (United States)

    Rich, Tyvin; Porter, Gerald W; Ricks-Santi, Luisel; Milshtein, Tzvi; Corbin, Thomas

    2017-10-01

    Objective: The hot flash is a common vasomotor disorder that causes distress in menopausal women and that can be debilitating in men with prostate cancer who are treated with androgen deprivation therapy (ADT). The utility of auricular electroacupuncture (AEA) was tested exclusively for a small cohort of men with ADT-induced vasomotor symptoms while the men underwent a course of curative radiotherapy. Materials and Methods: Prior to and during radiotherapy treatment, men with vasomotor symptoms were given repeated questionnaires regarding severity and frequency of hot flashes, quality of life (QoL), and sleep over a 6-week span of an AEA protocol. Each subject's heart rate variability (HRV) was obtained repeatedly every week in an ambulatory setting with a BlueCardio device (BlueCardio, Miami, FL). The AEA intervention was given with a Neurova device (Nunka Corporation, CM Wellness Clinic, Pompano Beach, FL) that used three needles at Master points Sympathetic, Shen Men , and Point Zero, which were located precisely with a bipolar point finder. Intermittent microcurrent stimulation was given every other week for 96 hours, using a cyclic programmed output of 2 hours on and 2 hours off. Results: Of 10 men completing the 6-week protocol, all responded with significantly lower frequency, duration, and severity of vasomotor symptoms; QoL and sleep scores improved significantly. The HRV analysis showed significantly lower low-frequency/high-frequency power ratios in each individual, compared to baseline, that were consistent with the subjective responses. Conclusions: Vasomotor disturbance, caused by gender hormone withdrawal-either naturally or in patients treated with ADT, as in this study-is a well-defined neurophysiologic condition. This disorder is a constellation of findings that reflect autonomic disturbances of excessive sympathetic and reduced parasympathetic activity. AEA intervention with the Neurova device is simple to administer, is well-tolerated, and

  8. Is an unfavourable cardiovascular risk profile a risk factor for vasomotor menopausal symptoms? Results of a population-based cohort study.

    Science.gov (United States)

    van den Berg, M J; Herber-Gast, G C M; van der Schouw, Y T

    2015-08-01

    Evidence suggests an association between vasomotor menopausal symptoms (VMSs), i.e. hot flushes and night sweats, and cardiovascular disease. However, the causal pathway is unclear. We investigated whether an unfavourable cardiovascular risk profile is a risk factor for VMS later in life. Retrospective cohort study. Women aged 50-70 from the general population. The Prospect-European Prospective Investigation into Cancer and Nutrition (Prospect-EPIC) cohort is a population-based cohort of women who enrolled between 1993 and 1997. Follow-up questionnaires were sent at 5-year intervals for 15 years. Women who returned the third questionnaire, answered questions regarding lifetime VMS and did not report VMS prior to baseline were included in this study (n = 1295). At baseline, the Framingham Risk Score (FRS) was determined. We used logistic regression analysis to calculate odds ratios (ORs) for the association between baseline FRS and incident VMS. Incident VMS. At baseline (mean age ± standard deviation, 52.2 ± 3.6 years), 21.2% had a FRS > 10%. During follow-up, 40.2% of women reported the onset of VMS. Adjusted for body mass index, physical activity, education and alcohol consumption, each point increase in FRS was associated with a decreased incidence of VMS [OR, 0.94 (95% CI, 0.91-0.97)]. Additional adjustment for menopausal status attenuated the OR to null [OR, 0.98 (95% CI, 0.95-1.01)]. None of the separate FRS variables were associated with VMS after adjustment for age. In our cohort, an unfavourable cardiovascular risk profile was not associated with VMS, and therefore we found no evidence for the involvement of a vascular mechanism in the etiology of VMS. © 2014 Royal College of Obstetricians and Gynaecologists.

  9. Electrical signaling, stomatal conductance, ABA and Ethylene content in avocado trees in response to root hypoxia

    Science.gov (United States)

    Gurovich, Luis; Schaffer, Bruce; García, Nicolás; Iturriaga, Rodrigo

    2009-01-01

    Avocado (Persea americana Mill.) trees are among the most sensitive of fruit tree species to root hypoxia as a result of flooded or poorly drained soil. Similar to drought stress, an early physiological response to root hypoxia in avocado is a reduction of stomatal conductance. It has been previously determined in avocado trees that an extracellular electrical signal between the base of stem and leaves is produced and related to reductions in stomatal conductance in response to drought stress. The current study was designed to determine if changes in the extracellular electrical potential between the base of the stem and leaves in avocado trees could also be detected in response to short-term (min) or long-term (days) root hypoxia, and if these signals could be related to stomatal conductance (gs), root and leaf ABA and ACC concentrations, ethylene emission from leaves and leaf abscission. In contrast to previous observations for drought-stressed trees, short-term or long-term root hypoxia did not stimulate an electrical potential difference between the base of the stem and leaves. Short-term hypoxia did not result in a significant decrease in gs compared with plants in the control treatment, and no differences in ABA concentration were found between plants subjected to hypoxia and control plants. Long-term hypoxia in the root zone resulted in a significant decrease in gs, increased leaf ethylene and increased leaf abscission. The results indicate that for avocado trees exposed to root hypoxia, electrical signals do not appear to be the primary root-to-shoot communication mechanism involved in signaling for stomatal closure as a result of hypoxia in the root zone. PMID:19649181

  10. Pulsed EM Field Response of a Thin, High-Contrast, Finely Layered Structure With Dielectric and Conductive Properties

    NARCIS (Netherlands)

    De Hoop, A.T.; Jiang, L.

    2009-01-01

    The response of a thin, high-contrast, finely layered structure with dielectric and conductive properties to an incident, pulsed, electromagnetic field is investigated theoretically. The fine layering causes the standard spatial discretization techniques to solve Maxwell's equations numerically to

  11. Education in the responsible conduct of research in psychology: methods and scope.

    Science.gov (United States)

    DiLorenzo, Terry A; Becker-Fiegeles, Jill; Gibelman, Margaret

    2014-01-01

    In this mixed-method study of education in the responsible conduct of research (RCR) in psychology, phase one survey respondents (n = 141) reported that faculty and students were familiar with RCR standards and procedures to educate them were believed to be adequate. However, educational methods varied widely. In phase two, seven survey respondents completed in-depth interviews assessing RCR training and education and research review procedures. Educational methods through which RCR content was presented included the following ones: traditional (lectures), technical (web-based), and experiential (internships), but RCR was often minimally considered in the formal curriculum. Our results suggest that psychology training programs might benefit from more formal consideration of RCR education and training in the curriculum.

  12. Mechanical and vasomotor properties of piglet isolated middle cerebral artery

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R.; Abdolalizadeh, Bahareh; Trautner, Simon

    2017-01-01

    in newborns, is not characterized in piglets’ MCA. Finally, the influence of preterm birth on the dopamine response is not known. The aim of this current was to compare by wire myography the active and passive mechanical characteristics and dopamine concentration–response relations of MCAs isolated from...... to increasing concentrations of dopamine was biphasic, starting with vasodilation in the 1 nmol/L–0.3 μmol/L concentration range followed by vasoconstriction at higher concentrations. The response was very similar between the two groups. In conclusion, the mechanical properties of the MCA as well...

  13. Real-Time Gas Identification by Analyzing the Transient Response of Capillary-Attached Conductive Gas Sensor

    Directory of Open Access Journals (Sweden)

    Behzad Bahraminejad

    2010-05-01

    Full Text Available In this study, the ability of the Capillary-attached conductive gas sensor (CGS in real-time gas identification was investigated. The structure of the prototype fabricated CGS is presented. Portions were selected from the beginning of the CGS transient response including the first 11 samples to the first 100 samples. Different feature extraction and classification methods were applied on the selected portions. Validation of methods was evaluated to study the ability of an early portion of the CGS transient response in target gas (TG identification. Experimental results proved that applying extracted features from an early part of the CGS transient response along with a classifier can distinguish short-chain alcohols from each other perfectly. Decreasing time of exposition in the interaction between target gas and sensing element improved the reliability of the sensor. Classification rate was also improved and time of identification was decreased. Moreover, the results indicated the optimum interval of the early transient response of the CGS for selecting portions to achieve the best classification rates.

  14. Axonal Conduction Delays, Brain State, and Corticogeniculate Communication.

    Science.gov (United States)

    Stoelzel, Carl R; Bereshpolova, Yulia; Alonso, Jose-Manuel; Swadlow, Harvey A

    2017-06-28

    Thalamocortical conduction times are short, but layer 6 corticothalamic axons display an enormous range of conduction times, some exceeding 40-50 ms. Here, we investigate (1) how axonal conduction times of corticogeniculate (CG) neurons are related to the visual information conveyed to the thalamus, and (2) how alert versus nonalert awake brain states affect visual processing across the spectrum of CG conduction times. In awake female Dutch-Belted rabbits, we found 58% of CG neurons to be visually responsive, and 42% to be unresponsive. All responsive CG neurons had simple, orientation-selective receptive fields, and generated sustained responses to stationary stimuli. CG axonal conduction times were strongly related to modulated firing rates (F1 values) generated by drifting grating stimuli, and their associated interspike interval distributions, suggesting a continuum of visual responsiveness spanning the spectrum of axonal conduction times. CG conduction times were also significantly related to visual response latency, contrast sensitivity (C-50 values), directional selectivity, and optimal stimulus velocity. Increasing alertness did not cause visually unresponsive CG neurons to become responsive and did not change the response linearity (F1/F0 ratios) of visually responsive CG neurons. However, for visually responsive CG neurons, increased alertness nearly doubled the modulated response amplitude to optimal visual stimulation (F1 values), significantly shortened response latency, and dramatically increased response reliability. These effects of alertness were uniform across the broad spectrum of CG axonal conduction times. SIGNIFICANCE STATEMENT Corticothalamic neurons of layer 6 send a dense feedback projection to thalamic nuclei that provide input to sensory neocortex. While sensory information reaches the cortex after brief thalamocortical axonal delays, corticothalamic axons can exhibit conduction delays of <2 ms to 40-50 ms. Here, in the corticogeniculate

  15. Comparison of blood volume pulse and skin conductance responses to mental and affective stimuli at different anatomical sites

    International Nuclear Information System (INIS)

    Kushki, Azadeh; Fairley, Jillian; Merja, Satyam; King, Gillian; Chau, Tom

    2011-01-01

    Measurements of blood volume pulse (BVP) and skin conductance are commonly used as indications of psychological arousal in affective computing and human–machine interfaces. To date, palmar surfaces remain the primary site for these measurements. Placement of sensors on palmar surfaces, however, is undesirable when recordings are fraught with motion and pressure artifacts. These artifacts are frequent when the human participant has involuntary movements as in hyperkinetic cerebral palsy. This motivates the use of alternative measurement sites. The present study examined the correlation between measurements of blood volume pulse and skin conductance obtained from three different sites on the body (fingers, toes and ear for BVP; fingers, toes and arch of the foot for skin conductance) in response to cognitive and affective stimuli. The results of this pilot study indicated significant inter-site correlation among signal features derived from different sites, with the exception of BVP amplitude, the number of electrodermal reactions and the slope of the electrodermal activity response. We attribute these differences in part to inter-site discrepancies in local skin conditions, such as skin temperature. Despite these differences, significant changes from baseline were present in the responses to the cognitive and affective stimuli at non-palmar sites, suggesting that these sites may provide viable signal measurements for use in affective computing and human–machine interface applications

  16. ATTRIBUTION OF CONDUCT TO A STATE-THE SUBJECTIVE ELEMENT OF THE INTERNATIONAL RESPONSIBILITY OT THE STATE FOR INTERNATIONALLY WRONGFUL ACTS

    Directory of Open Access Journals (Sweden)

    FELICIA MAXIM

    2012-05-01

    Full Text Available In order to establish responsibility of states for internationally wrongful act, two elements are identified. First, the conduct in question must be attributable to the State under international law. Secondly, for responsibility to attach to the act of the State, the conduct must constitute a breach of an international legal obligation in force for that State at that time. For particular conduct to be characterized as an internationally wrongful act, it must first be attributable to the State. The State is a real organized entity, a legal person with full authority to act under international law. But to recognize this is not to deny the elementary fact that the State cannot act of itself. States can act only by and through their agents and representatives. In determining what constitutes an organ of a State for the purposes of responsibility, the internal law and practice of each State are of prime importance. The structure of the State and the functions of its organs are not, in general, governed by international law. It is a matter for each State to decide how its administration is to be structured and which functions are to be assumed by government. But while the State remains free to determine its internal structure and functions through its own law and practice, international law has a distinct role. Conduct is thereby attributed to the State as a subject of international law and not as a subject of internal law. The State as a subject of international law is held responsible for the conduct of all the organs, instrumentalities and officials which form part of its organization and act in that capacity, whether or not they have separate legal personality under its internal law.

  17. Evaluating the effects that existing instruction on responsible conduct of research has on ethical decision making.

    Science.gov (United States)

    Antes, Alison L; Wang, Xiaoqian; Mumford, Michael D; Brown, Ryan P; Connelly, Shane; Devenport, Lynn D

    2010-03-01

    To examine the effects that existing courses on the responsible conduct of research (RCR) have on ethical decision making by assessing the ethicality of decisions made in response to ethical problems and the underlying processes involved in ethical decision making. These processes included how an individual thinks through ethical problems (i.e., meta-cognitive reasoning strategies) and the emphasis placed on social dimensions of ethical problems (i.e., social-behavioral responses). In 2005-2007, recruitment announcements were made, stating that a nationwide, online study was being conducted to examine the impact of RCR instruction on the ethical decision making of scientists. Recruitment yielded contacts with over 200 RCR faculty at 21 research universities and medical schools; 40 (20%) RCR instructors enrolled their courses in the current study. From those courses, 173 participants completed an ethical decision-making measure. A mixed pattern of effects emerged. The ethicality of decisions did not improve as a result of RCR instruction and even decreased for decisions pertaining to business aspects of research, such as contract bidding. Course participants improved on some meta-cognitive reasoning strategies, such as awareness of the situation and consideration of personal motivations, but declined for seeking help and considering others' perspectives. Participants also increased their endorsement of detrimental social-behavioral responses, such as deception, retaliation, and avoidance of personal responsibility. These findings indicated that RCR instruction may not be as effective as intended and, in fact, may even be harmful. Harmful effects might result if instruction leads students to overstress avoidance of ethical problems, be overconfident in their ability to handle ethical problems, or overemphasize their ethical nature. Future research must examine these and other possible obstacles to effective RCR instruction.

  18. Research as Profession and Practice: Frameworks for Guiding the Responsible Conduct of Research.

    Science.gov (United States)

    Chen, Jiin-Yu

    2016-01-01

    Programs in the responsible conduct of research (RCR) vary between institutions, demonstrated by disparate structures and goals. These variations may be attributed to the absence of grounding frameworks within which to examine research and RCR education programs. This article examines research as a practice and a profession, using these frames to draw out defining features of research and the moral obligations entailed. Situating research within virtue ethics can clarify how researchers might cultivate the virtues necessary for meeting its obligations and aims. By elucidating these features, these perspectives can serve to guide the development of RCR education programs.

  19. Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

    KAUST Repository

    Zhou, Jian; Li, Er Qiang; Lubineau, Gilles; Thoroddsen, Sigurdur T; Mulle, Matthieu

    2016-01-01

    A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy- thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet- spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S · cm-1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S · cm-1) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S · cm-1). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young's modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

  20. Semi-metallic, strong conductive polymer microfiber, method and fast response rate actuators and heating textiles

    KAUST Repository

    Zhou, Jian

    2016-06-09

    A method comprising: providing at least one first composition comprising at least one conjugated polymer and at least one solvent, wet spinning the at least one first composition to form at least one first fiber material, hot-drawing the at least one fiber to form at least one second fiber material. In lead embodiments, high-performance poly(3,4-ethylenedioxy- thiophene)/poly(styrenesulfonate) (PEDOT/PSS) conjugated polymer microfibers were fabricated via wet- spinning followed by hot-drawing. In these lead embodiments, due to the combined effects of the vertical hot-drawing process and doping/de-doping the microfibers with ethylene glycol (EG), a record electrical conductivity of 2804 S · cm-1 was achieved. This is believed to be a six-fold improvement over the best previously reported value for PEDOT/PSS fibers (467 S · cm-1) and a twofold improvement over the best values for conductive polymer films treated by EG de-doping (1418 S · cm-1). Moreover, these lead, highly conductive fibers experience a semiconductor-metal transition at 313 K. They also have superior mechanical properties with a Young\\'s modulus up to 8.3 GPa, a tensile strength reaching 409.8 MPa and a large elongation before failure (21%). The most conductive fiber also demonstrates an extraordinary electrical performance during stretching/unstretching: the conductivity increased by 25% before the fiber rupture point with a maximum strain up to 21%. Simple fabrication of the semi-metallic, strong and stretchable wet-spun PEDOT/PSS microfibers can make them available for conductive smart electronics. A dramatic improvement in electrical conductivity is needed to make conductive polymer fibers viable candidates in applications such as flexible electrodes, conductive textiles, and fast-response sensors and actuators.

  1. Applicability of cable theory to vascular conducted responses

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Jensen, Lars Jørn; Sørensen, Preben Graae

    2012-01-01

    Conduction processes in the vasculature have traditionally been described using cable theory, i.e., locally induced signals decaying passively along the arteriolar wall. The decay is typically quantified using the steady-state length-constant, ¿, derived from cable theory. However......, the applicability of cable theory to blood vessels depends on assumptions that are not necessarily fulfilled in small arteries and arterioles. We have employed a morphologically and electrophysiologically detailed mathematical model of a rat mesenteric arteriole to investigate if the assumptions hold and whether...... ¿ adequately describes simulated conduction profiles. We find that several important cable theory assumptions are violated when applied to small blood vessels. However, the phenomenological use of a length-constant from a single exponential function is a good measure of conduction length. Hence, ¿ should...

  2. Threshold responses of Blackside Dace (Chrosomus cumberlandensis) and Kentucky Arrow Darter (Etheostoma spilotum) to stream conductivity

    Science.gov (United States)

    Hitt, Nathaniel P.; Floyd, Michael; Compton, Michael; McDonald, Kenneth

    2016-01-01

    Chrosomus cumberlandensis (Blackside Dace [BSD]) and Etheostoma spilotum (Kentucky Arrow Darter [KAD]) are fish species of conservation concern due to their fragmented distributions, their low population sizes, and threats from anthropogenic stressors in the southeastern United States. We evaluated the relationship between fish abundance and stream conductivity, an index of environmental quality and potential physiological stressor. We modeled occurrence and abundance of KAD in the upper Kentucky River basin (208 samples) and BSD in the upper Cumberland River basin (294 samples) for sites sampled between 2003 and 2013. Segmented regression indicated a conductivity change-point for BSD abundance at 343 μS/cm (95% CI: 123–563 μS/cm) and for KAD abundance at 261 μS/cm (95% CI: 151–370 μS/cm). In both cases, abundances were negligible above estimated conductivity change-points. Post-hoc randomizations accounted for variance in estimated change points due to unequal sample sizes across the conductivity gradients. Boosted regression-tree analysis indicated stronger effects of conductivity than other natural and anthropogenic factors known to influence stream fishes. Boosted regression trees further indicated threshold responses of BSD and KAD occurrence to conductivity gradients in support of segmented regression results. We suggest that the observed conductivity relationship may indicate energetic limitations for insectivorous fishes due to changes in benthic macroinvertebrate community composition.

  3. Predicting Treatment Response for Oppositional Defiant and Conduct Disorder Using Pre-treatment Adrenal and Gonadal Hormones.

    Science.gov (United States)

    Shenk, Chad E; Dorn, Lorah D; Kolko, David J; Susman, Elizabeth J; Noll, Jennie G; Bukstein, Oscar G

    2012-12-01

    Variations in adrenal and gonadal hormone profiles have been linked to increased rates of oppositional defiant disorder (ODD) and conduct disorder (CD). These relationships suggest that certain hormone profiles may be related to how well children respond to psychological treatments for ODD and CD. The current study assessed whether pre-treatment profiles of adrenal and gonadal hormones predicted response to psychological treatment of ODD and CD. One hundred five children, 6 - 11 years old, participating in a randomized, clinical trial provided samples for cortisol, testosterone, dehydroepiandrosterone, and androstenedione. Diagnostic interviews of ODD and CD were administered up to three years post-treatment to track treatment response. Group-based trajectory modeling identified two trajectories of treatment response: 1) a High-response trajectory where children demonstrated lower rates of an ODD or CD diagnosis throughout follow-up, and 2) a Low-response trajectory where children demonstrated higher rates of an ODD or CD diagnosis throughout follow-up. Hierarchical logistic regression predicting treatment response demonstrated that children with higher pre-treatment concentrations of testosterone were four times more likely to be in the Low-response trajectory. No other significant relationship existed between pre-treatment hormone profiles and treatment response. These results suggest that higher concentrations of testosterone are related to how well children diagnosed with ODD or CD respond to psychological treatment over the course of three years.

  4. Auditory brainstem responses of CBA/J mice with neonatal conductive hearing losses and treatment with GM1 ganglioside.

    Science.gov (United States)

    Money, M K; Pippin, G W; Weaver, K E; Kirsch, J P; Webster, D B

    1995-07-01

    Exogenous administration of GM1 ganglioside to CBA/J mice with a neonatal conductive hearing loss ameliorates the atrophy of spiral ganglion neurons, ventral cochlear nucleus neurons, and ventral cochlear nucleus volume. The present investigation demonstrates the extent of a conductive loss caused by atresia and tests the hypothesis that GM1 ganglioside treatment will ameliorate the conductive hearing loss. Auditory brainstem responses were recorded from four groups of seven mice each: two groups received daily subcutaneous injections of saline (one group had normal hearing; the other had a conductive hearing loss); the other two groups received daily subcutaneous injections of GM1 ganglioside (one group had normal hearing; the other had a conductive hearing loss). In mice with a conductive loss, decreases in hearing sensitivity were greatest at high frequencies. The decreases were determined by comparing mean ABR thresholds of the conductive loss mice with those of normal hearing mice. The conductive hearing loss induced in the mice in this study was similar to that seen in humans with congenital aural atresias. GM1 ganglioside treatment had no significant effect on ABR wave I thresholds or latencies in either group.

  5. Subsurface Flow and Moisture Dynamics in Response to Swash Motions: Effects of Beach Hydraulic Conductivity and Capillarity

    Science.gov (United States)

    Geng, Xiaolong; Heiss, James W.; Michael, Holly A.; Boufadel, Michel C.

    2017-12-01

    A combined field and numerical study was conducted to investigate dynamics of subsurface flow and moisture response to waves in the swash zone of a sandy beach located on Cape Henlopen, DE. A density-dependent variably saturated flow model MARUN was used to simulate subsurface flow beneath the swash zone. Values of hydraulic conductivity (K) and characteristic pore size (α, a capillary fringe property) were varied to evaluate their effects on subsurface flow and moisture dynamics in response to swash motions in beach aquifers. The site-specific modeling results were validated against spatiotemporal measurements of moisture and pore pressure in the beach. Sensitivity analyses indicated that the hydraulic conductivity and capillary fringe thickness of the beach greatly influenced groundwater flow pathways and associated transit times in the swash zone. A higher value of K enhanced swash-induced seawater infiltration into the beach, thereby resulting in a faster expansion of a wedge of high moisture content induced by swash cycles, and a flatter water table mound beneath the swash zone. In contrast, a thicker capillary fringe retained higher moisture content near the beach surface, and thus, significantly reduced the available pore space for infiltration of seawater. This attenuated wave effects on pore water flow in the unsaturated zone of the beach. Also, a thicker capillary fringe enhanced horizontal flow driven by the larger-scale hydraulic gradient caused by tides.

  6. Establishing good collaborative research practices in the responsible conduct of research in nursing science.

    Science.gov (United States)

    Ulrich, Connie M; Wallen, Gwenyth R; Cui, Naixue; Chittams, Jesse; Sweet, Monica; Plemmons, Dena

    2015-01-01

    Team science is advocated to speed the pace of scientific discovery, yet the goals of collaborative practice in nursing science and the responsibilities of nurse stakeholders are sparse and inconclusive. The purpose of this study was to examine nurse scientists' views on collaborative research as part of a larger study on standards of scientific conduct. Web-based descriptive survey of nurse scientists randomly selected from 50 doctoral graduate programs in the United States. Nearly forty percent of nurse respondents were not able to identify good collaborative practices for the discipline; more than three quarters did not know of any published guidelines available to them. Successful research collaborations were challenged by different expectations of authorship and data ownership, lack of timeliness and communication, poorly defined roles and responsibilities, language barriers, and when they involve junior and senior faculty working together on a project. Individual and organizational standards, practices, and policies for collaborative research needs clarification within the discipline. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Autonomic control of heart rate during orthostasis and the importance of orthostatic-tachycardia in the snake Python molurus.

    Science.gov (United States)

    Armelin, Vinicius Araújo; da Silva Braga, Victor Hugo; Abe, Augusto Shinya; Rantin, Francisco Tadeu; Florindo, Luiz Henrique

    2014-10-01

    Orthostasis dramatically influences the hemodynamics of terrestrial vertebrates, especially large and elongated animals such as snakes. When these animals assume a vertical orientation, gravity tends to reduce venous return, cardiac filling, cardiac output and blood pressure to the anterior regions of the body. The hypotension triggers physiological responses, which generally include vasomotor adjustments and tachycardia to normalize blood pressure. While some studies have focused on understanding the regulation of these vasomotor adjustments in ectothermic vertebrates, little is known about regulation and the importance of heart rate in these animals during orthostasis. We acquired heart rate and carotid pulse pressure (P PC) in pythons in their horizontal position, and during 30 and 60° inclinations while the animals were either untreated (control) or upon muscarinic cholinoceptor blockade and a double autonomic blockade. Double autonomic blockade completely eradicated the orthostatic-tachycardia, and without this adjustment, the P PC reduction caused by the tilts became higher than that which was observed in untreated animals. On the other hand, post-inclinatory vasomotor adjustments appeared to be of negligible importance in counterbalancing the hemodynamic effects of gravity. Finally, calculations of cardiac autonomic tones at each position revealed that the orthostatic-tachycardia is almost completely elicited by a withdrawal of vagal drive.

  8. Bone-Conduction ABR Tests.

    Science.gov (United States)

    Cone-Wesson, Barbara

    1995-01-01

    This article discusses the accuracy of bone-conduction auditory brainstem response (BC-ABR) tests to determine the presence and severity of conductive hearing impairment. It provides warnings about technical pitfalls and recommends incorporating BC-ABR protocols for routine clinical use. It concludes that the method allows estimating cochlear…

  9. Meso-scale modelling of the heat conductivity effect on the shock response of a porous material

    Science.gov (United States)

    Resnyansky, A. D.

    2017-06-01

    Understanding of deformation mechanisms of porous materials under shock compression is important for tailoring material properties at the shock manufacturing of advanced materials from substrate powders and for studying the response of porous materials under shock loading. Numerical set-up of the present work considers a set of solid particles separated by air representing a volume of porous material. Condensed material in the meso-scale set-up is simulated with a viscoelastic rate sensitive material model with heat conduction formulated from the principles of irreversible thermodynamics. The model is implemented in the CTH shock physics code. The meso-scale CTH simulation of the shock loading of the representative volume reveals the mechanism of pore collapse and shows in detail the transition from a high porosity case typical for abnormal Hugoniot response to a moderate porosity case typical for conventional Hugoniot response. Results of the analysis agree with previous analytical considerations and support hypotheses used in the two-phase approach.

  10. Ictal but not interictal epileptic discharges activate astrocyte endfeet and elicit cerebral arteriole responses.

    Directory of Open Access Journals (Sweden)

    Marta eGomez-Gonzalo

    2011-06-01

    Full Text Available Activation of astrocytes by neuronal signals plays a central role in the control of neuronal activity-dependent blood flow changes in the normal brain. The cellular pathways that mediate neurovascular coupling in the epileptic brain remain, however, poorly defined. In a cortical slice model of epilepsy, we found that the ictal, seizure-like discharge, and only to a minor extent the interictal discharge, evokes both a Ca2+ increase in astrocyte endfeet and a vasomotor response. We also observed that rapid ictal discharge-induced arteriole responses were regularly preceded by Ca2+ elevations in endfeet and were abolished by pharmacological inhibition of Ca2+ signals in these astrocyte processes. Under these latter conditions, arterioles exhibited after the ictal discharge only slowly developing vasodilations. The poor efficacy of interictal discharges, compared with ictal discharges, to activate endfeet was confirmed also in the intact in vitro isolated guinea pig brain. Although the possibility of a direct contribution of neurons, in particular in the late response of cerebral blood vessels to epileptic discharges, should be taken into account, our study supports the view that astrocytes are central for neurovascular coupling also in the epileptic brain. The massive endfeet Ca2+ elevations evoked by ictal discharges and the poor response to interictal events represent new information potentially relevant to interpret data from diagnostic brain imaging techniques, such as functional magnetic resonance, utilized in the clinic to localize neural activity and to optimize neurosurgery of untreatable epilepsies.

  11. The response of guinea pig primary utricular and saccular irregular neurons to bone-conducted vibration (BCV) and air-conducted sound (ACS).

    Science.gov (United States)

    Curthoys, Ian S; Vulovic, Vedran; Burgess, Ann M; Sokolic, Ljiljana; Goonetilleke, Samanthi C

    2016-01-01

    This study sought to characterize the response of mammalian primary otolithic neurons to sound and vibration by measuring the resting discharge rates, thresholds for increases in firing rate and supra-threshold sensitivity functions of guinea pig single primary utricular and saccular afferents. Neurons with irregular resting discharge were activated in response to bone conducted vibration (BCV) and air conducted sound (ACS) for frequencies between 100 Hz and 3000 Hz. The location of neurons was verified by labelling with neurobiotin. Many afferents from both maculae have very low or zero resting discharge, with saccular afferents having on average, higher resting rates than utricular afferents. Most irregular utricular and saccular afferents can be evoked by both BCV and ACS. For BCV stimulation: utricular and saccular neurons show similar low thresholds for increased firing rate (around 0.02 g on average) for frequencies from 100 Hz to 750 Hz. There is a steep increase in rate change threshold for BCV frequencies above 750 Hz. The suprathreshold sensitivity functions for BCV were similar for both utricular and saccular neurons, with, at low frequencies, very steep increases in firing rate as intensity increased. For ACS stimulation: utricular and saccular neurons can be activated by high intensity stimuli for frequencies from 250 Hz to 3000 Hz with similar flattened U-shaped tuning curves with lowest thresholds for frequencies around 1000-2000 Hz. The average ACS thresholds for saccular afferents across these frequencies is about 15-20 dB lower than for utricular neurons. The suprathreshold sensitivity functions for ACS were similar for both utricular and saccular neurons. Both utricular and saccular afferents showed phase-locking to BCV and ACS, extending up to frequencies of at least around 1500 Hz for BCV and 3000 Hz for ACS. Phase-locking at low frequencies (e.g. 100 Hz) imposes a limit on the neural firing rate evoked by the stimulus since the

  12. Auditory Steady-State Response Thresholds in Adults With Conductive and Mild to Moderate Sensorineural Hearing Loss

    OpenAIRE

    Hosseinabadi, Reza; Jafarzadeh, Sadegh

    2014-01-01

    Background: The Auditory steady state response (ASSR) provides a frequency-specific and automatic assessment of hearing sensitivity and is used in infants and difficult-to-test adults. Objectives: The aim of this study was to compare the ASSR thresholds among various types (normal, conductive, and sensorineural), degree (normal, mild, and moderate), and configuration (flat and sloping) of hearing sensitivity, and measuring the cutoff point between normal condition and hearing loss for differe...

  13. Skin Conductance Responses and Neural Activations During Fear Conditioning and Extinction Recall Across Anxiety Disorders.

    Science.gov (United States)

    Marin, Marie-France; Zsido, Rachel G; Song, Huijin; Lasko, Natasha B; Killgore, William D S; Rauch, Scott L; Simon, Naomi M; Milad, Mohammed R

    2017-06-01

    The fear conditioning and extinction neurocircuitry has been extensively studied in healthy and clinical populations, with a particular focus on posttraumatic stress disorder. Despite significant overlap of symptoms between posttraumatic stress disorder and anxiety disorders, the latter has received less attention. Given that dysregulated fear levels characterize anxiety disorders, examining the neural correlates of fear and extinction learning may shed light on the pathogenesis of underlying anxiety disorders. To investigate the psychophysiological and neural correlates of fear conditioning and extinction recall in anxiety disorders and to document how these features differ as a function of multiple diagnoses or anxiety severity. This investigation was a cross-sectional, case-control, functional magnetic resonance imaging study at an academic medical center. Participants were healthy controls and individuals with at least 1 of the following anxiety disorders: generalized anxiety disorder, social anxiety disorder, specific phobia, and panic disorder. The study dates were between March 2013 and May 2015. Two-day fear conditioning and extinction paradigm. Skin conductance responses, blood oxygenation level-dependent responses, trait anxiety scores from the State Trait Anxiety Inventory-Trait Form, and functional connectivity. This study included 21 healthy controls (10 women) and 61 individuals with anxiety disorders (36 women). P values reported for the neuroimaging results are all familywise error corrected. Skin conductance responses during extinction recall did not differ between individuals with anxiety disorders and healthy controls (ηp2 = 0.001, P = .79), where ηp2 is partial eta squared. The anxiety group had lower activation of the ventromedial prefrontal cortex (vmPFC) during extinction recall (ηp2 = 0.178, P = .02). A similar hypoactive pattern was found during early conditioning (ηp2 = 0.106, P = .009). The vmPFC hypoactivation

  14. Preparation, conduct and evaluation of exercises to test preparedness for a nuclear or radiological emergency. Emergency preparedness and response

    International Nuclear Information System (INIS)

    2005-04-01

    The aim of this publication is to serve as a practical tool for the preparation, conduct and evaluation of exercises to test preparedness for response to a nuclear or radiological emergency. It fulfils in part the functions assigned to the IAEA under Article 5.a(ii) of the Convention on Assistance in Case of a Nuclear Accident or Radiological Emergency (Assistance Convention), namely, to collect and disseminate to States Parties and Member States information concerning the methodologies, techniques and available results of research on such emergencies. To ensure effective response to radiation emergencies when needed, provisions should be made for regular training of emergency response personnel. As stated in Preparedness and Response for a Nuclear or Radiological Emergency (Safety Requirements, Safety Standard Series No. GS-R-2), 'The operator and the response organizations shall make arrangements for the selection of personnel and training to ensure that the personnel have the requisite knowledge, skills, abilities, equipment, procedures and other arrangements to perform their assigned response functions'. A further requirement is that 'Exercise programmes shall be conducted to ensure that all specified functions required to be performed for emergency response and all organizational interfaces for facilities in threat category I, II or III and the national level programmes for threat category IV or V are tested at suitable intervals'. In 2004 the IAEA General Conference, in resolution GC(48)/RES/10 encouraged Member States to 'implement the Safety Requirements for Preparedness and Response to a Nuclear or Radiological Emergency'. This document is published as part of the IAEA Emergency Preparedness and Response Series to assist in meeting these requirements and to fulfil Article 5 of the Assistance Convention. It was developed based on a number of assumptions about national and local capabilities. Therefore, the exercise structure, terms and scenarios must be

  15. Analysis of skin conductance response during evaluation of preferences for cosmetic products

    Science.gov (United States)

    Ohira, Hideki; Hirao, Naoyasu

    2015-01-01

    We analyzed skin conductance response (SCR) as a psychophysiological index to evaluate affective aspects of consumer preferences for cosmetic products. To examine the test-retest reliability of association between preferences and SCR, we asked 33 female volunteers to complete two experimental sessions approximately 1 year apart. The participants indicated their preferences in a typical paired comparison task by choosing the better option from a combination of two products among four products. We measured anticipatory SCR prior to expressions of the preferences. We found that the mean amplitude of the SCR elicited by the preferred products was significantly larger than that elicited by the non-preferred products. The participants' preferences and corresponding SCR patterns were well preserved at the second session 1 year later. Our results supported cumulating findings that SCR is a useful index of consumer preferences that has future potential, both in laboratory and marketing settings. PMID:25709593

  16. The response of a harmonically forced premixed flame stabilized on a heat-conducting bluff-body

    KAUST Repository

    Kedia, Kushal S.

    2015-01-01

    © 2014 The Combustion Institute. The objective of this work is to investigate the unsteady response of a bluff-body stabilized laminar premixed flame to harmonic inlet velocity excitation. A time series analysis was performed to analyze the physical sequence of events at a fixed longitudinal forcing frequency of 100 Hz for cases with (1) two different equivalence ratios and (2) two different thermal properties of the stabilizing bluff-body. It was observed that conjugate heat exchange between the heat conducting bluff-body and the surrounding reacting flow has a crucial impact on the dynamic response. The flame area and anchoring location, the net conjugate heat transfer and the total heat release underwent significant oscillations. The latter was mean shifted and had multiple frequencies. The burning velocity varied significantly along the flame length and the recirculation zone underwent complex changes in its shape and size during an unsteady cycle. The lower equivalence ratio case exhibited vortex shedding after an initial symmetric response with periodic flame extinction and re-ignition along its surface, unlike the higher equivalence ratio case. The metal/ceramic bluff-body showed a net heat transfer directed from/to the bluff-body, to/from the reacting flow during an unsteady cycle, resulting in a significantly different flame response for the two otherwise equivalent cases.

  17. Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs). A Study on Creep Response and Dynamic Loading.

    Science.gov (United States)

    Paredes-Madrid, Leonel; Matute, Arnaldo; Bareño, Jorge O; Parra Vargas, Carlos A; Gutierrez Velásquez, Elkin I

    2017-11-21

    Force Sensing Resistors (FSRs) are manufactured by sandwiching a Conductive Polymer Composite (CPC) between metal electrodes. The piezoresistive property of FSRs has been exploited to perform stress and strain measurements, but the rheological property of polymers has undermined the repeatability of measurements causing creep in the electrical resistance of FSRs. With the aim of understanding the creep phenomenon, the drift response of thirty two specimens of FSRs was studied using a statistical approach. Similarly, a theoretical model for the creep response was developed by combining the Burger's rheological model with the equations for the quantum tunneling conduction through thin insulating films. The proposed model and the experimental observations showed that the sourcing voltage has a strong influence on the creep response; this observation-and the corresponding model-is an important contribution that has not been previously accounted. The phenomenon of sensitivity degradation was also studied. It was found that sensitivity degradation is a voltage-related phenomenon that can be avoided by choosing an appropriate sourcing voltage in the driving circuit. The models and experimental observations from this study are key aspects to enhance the repeatability of measurements and the accuracy of FSRs.

  18. Lower responsiveness of canopy evapotranspiration rate than of leaf stomatal conductance to open-air CO2 elevation in rice.

    Science.gov (United States)

    Shimono, Hiroyuki; Nakamura, Hirofumi; Hasegawa, Toshihiro; Okada, Masumi

    2013-08-01

    An elevated atmospheric CO2 concentration ([CO2 ]) can reduce stomatal conductance of leaves for most plant species, including rice (Oryza sativa L.). However, few studies have quantified seasonal changes in the effects of elevated [CO2 ] on canopy evapotranspiration, which integrates the response of stomatal conductance of individual leaves with other responses, such as leaf area expansion, changes in leaf surface temperature, and changes in developmental stages, in field conditions. We conducted a field experiment to measure seasonal changes in stomatal conductance of the uppermost leaves and in the evapotranspiration, transpiration, and evaporation rates using a lysimeter method. The study was conducted for flooded rice under open-air CO2 elevation. Stomatal conductance decreased by 27% under elevated [CO2 ], averaged throughout the growing season, and evapotranspiration decreased by an average of 5% during the same period. The decrease in daily evapotranspiration caused by elevated [CO2 ] was more significantly correlated with air temperature and leaf area index (LAI) rather than with other parameters of solar radiation, days after transplanting, vapor-pressure deficit and FAO reference evapotranspiration. This indicates that higher air temperatures, within the range from 16 to 27 °C, and a larger LAI, within the range from 0 to 4 m(2)  m(-2) , can increase the magnitude of the decrease in evapotranspiration rate caused by elevated [CO2 ]. The crop coefficient (i.e. the evapotranspiration rate divided by the FAO reference evapotranspiration rate) was 1.24 at ambient [CO2 ] and 1.17 at elevated [CO2 ]. This study provides the first direct measurement of the effects of elevated [CO2 ] on rice canopy evapotranspiration under open-air conditions using the lysimeter method, and the results will improve future predictions of water use in rice fields. © 2013 John Wiley & Sons Ltd.

  19. Different brain responses during empathy in autism spectrum disorders versus conduct disorder and callous-unemotional traits.

    Science.gov (United States)

    Klapwijk, Eduard T; Aghajani, Moji; Colins, Olivier F; Marijnissen, Godfried M; Popma, Arne; van Lang, Natasja D J; van der Wee, Nic J A; Vermeiren, Robert R J M

    2016-06-01

    Deficits in empathy are reported in autism spectrum disorders (ASD) and also underlie antisocial behavior of individuals with conduct disorder and callous-unemotional traits (CD/CU+). Many studies suggest that individuals with ASD are typically impaired in cognitive aspects of empathy, and individuals with CD/CU+ typically in affective aspects. In the current study, we compared the neural correlates of cognitive and affective aspects of empathy between youth with ASD and youth with CD/CU+. Functional magnetic resonance imaging (fMRI) was used to assess boys with ASD (N = 23), boys with CD/CU+ (N = 23), and typically developing (TD) boys (N = 33), aged 15-19 years. Angry and fearful faces were presented and participants were asked to either infer the emotional state from the face (other-task; emotion recognition) or to judge their own emotional response to the face (self-task; emotional resonance). During emotion recognition, boys with ASD showed reduced responses compared to the other groups in the ventromedial prefrontal cortex (vmPFC). During emotional resonance, the CD/CU+ and ASD groups showed reduced amygdala responses compared to the TD controls, boys with ASD showed reduced responses in bilateral hippocampus, and the CD/CU+ boys showed reduced responses in the inferior frontal gyrus (IFG) and anterior insula (AI). Results suggest differential abnormal brain responses associated with specific aspects of empathic functioning in ASD and CD/CU+. Decreased amygdala responses in ASD and CD/CU+ might point to impaired emotion processing in both disorders, whereas reduced vmPFC responses suggest problems in processing cognitive aspects of empathy in ASD. Reduced IFG/AI responses, finally, suggest decreased emotional resonance in CD/CU+. © 2015 Association for Child and Adolescent Mental Health.

  20. An analytical model for the prediction of the dynamic response of premixed flames stabilized on a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.

    2013-01-01

    The dynamic response of a premixed flame stabilized on a heat-conducting perforated plate depends critically on their coupled thermal interaction. The objective of this paper is to develop an analytical model to capture this coupling. The model predicts the mean flame base standoff distance; the flame base area, curvature and speed; and the burner plate temperature given the operating conditions; the mean velocity, temperature and equivalence ratio of the reactants; thermal conductivity and the perforation ratio of the burner. This coupled model is combined with our flame transfer function (FTF) model to predict the dynamic response of the flame to velocity perturbations. We show that modeling the thermal coupling between the flame and the burner, while accounting for the two-dimensionality of the former, is critical to predicting the dynamic response characteristics such as the overshoot in the gain curve (resonant condition) and the phase delay. Good agreement with the numerical and experimental results is demonstrated over a range of conditions. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  1. Behaviour of conductivity improvers in jet fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dacre, B.; Hetherington, J.I. [Cranfield Univ., Wiltshire (United Kingdom)

    1995-05-01

    Dangerous accumulation of electrostatic charge can occur due to high speed pumping and microfiltration of fuel. This can be avoided by increasing the electrical conductivity of the fuel using conductivity improver additives. However, marked variations occur in the conductivity response of different fuels when doped to the same level with conductivity improver. This has been attributed to interactions of the conductivity improver with other fuel additives or fuel contaminants. The present work concentrates on the effects of fuel contaminants, in particular polar compounds, on the performance of the conductivity improver. Conductivity is the fuel property of prime interest. The conductivity response of model systems of the conductivity improver STADIS 450 in dodecane has been measured and the effect on this conductivity of additions of model polar contaminants sodium naphthenate, sodium dodecyl benzene sulphonate, and sodium phenate have been measured. The sodium salts have been found to have a complex effect on the performance of STADIS 450, reducing the conductivity at low concentrations to a minimum value and then increasing the conductivity at high concentrations of sodium salts. This work has focused on characterising this minimum in the conductivity values and on understanding the reason for its occurrence. The effects on the minimum conductivity value of the following parameters are investigated: (a) time, (b) STADIS 450 concentration, (c) sodium salt concentration, (d) mixed sodium salts, (e) experimental method, (f) a phenol, (g) individual components of STADIS 450. The complex conductivity response of the STADIS 450 to sodium salt impurities is discussed in terms of possible inter-molecular interactions.

  2. Research Ethics I: Responsible Conduct of Research (RCR)--Historical and Contemporary Issues Pertaining to Human and Animal Experimentation

    Science.gov (United States)

    Horner, Jennifer; Minifie, Fred D.

    2011-01-01

    Purpose: In this series of articles--"Research Ethics I", "Research Ethics II", and "Research Ethics III"--the authors provide a comprehensive review of the 9 core domains for the responsible conduct of research (RCR) as articulated by the Office of Research Integrity. In "Research Ethics I", they present a historical overview of the evolution of…

  3. An overview of menopause associated Vaso Motor Symptoms and ...

    African Journals Online (AJOL)

    BACKGROUND: Vasomotor Symptoms are the most common and distressing menopausal complaint, for which women seek advice from their physician. OBJECTIVE: To review menopausal associated vasomotor symptoms and options available in its management. METHODS: Pertinent literature on menopause associated ...

  4. Attachment and conduct disorder: The Response Programme.

    OpenAIRE

    Holland, R.; Moretti, M. M.; Verlaan, V.; Peterson, S.

    1993-01-01

    An increasing number of youths are being identified as suffering from behavioral problems that cause difficulties in their family and peer relations, which in turn reduce their chances of academic and vocational success. The common diagnosis given to these disaffiliated youths is conduct disorder. A community-oriented program designed to ensure long-term care for these youths is described. The program is designed to focus members of the youth's environment on the attachment and affiliation is...

  5. Soil water sensor response to bulk electrical conductivity

    Science.gov (United States)

    Soil water monitoring using electromagnetic (EM) sensors can facilitate observations of water content at high temporal and spatial resolutions. These sensors measure soil dielectric permittivity (Ka) which is largely a function of volumetric water content. However, bulk electrical conductivity BEC c...

  6. Are We Afraid of Different Categories of Stimuli in Identical Ways? Evidence from Skin Conductance Responses

    Science.gov (United States)

    Yang, Jiongjiong

    2013-01-01

    Studies have shown that emotional pictures attract more attention than neutral pictures, and pictures of living stimuli have similar advantage in driving attention (vs. nonliving). However, factors of emotion, category and picture context are usually mixed so that whether living and nonliving categories elicit different skin conductance (SC) responses, in both conscious and unconscious conditions, remains to be clarified. In this study, participants were presented with negative and neutral pictures denoting different living and nonliving concepts in conscious (Experiments 1 and 2) and unconscious conditions (40ms, Experiment 3) when their SC responses were measured. The picture context was manipulated in Experiments 2 and 3 as half including human-related information. In three experiments, the emotional levels of different categories were matched in different and identical cohorts of participants. The results showed that living pictures in a negative, high-arousing dimension elicited stronger SC responses than nonliving pictures. When nonhuman animals and inanimate objects were compared, the increased SC responses to animals was obtained only for negative pictures without human contexts in the conscious condition, but regardless of human context in the unconscious condition. These results suggested that contextual information and level of conscious awareness are important to modulate the animate advantage in emotional processing. PMID:24039879

  7. Thermographic analysis and autonomic response in the hands of patients with leprosy.

    Science.gov (United States)

    Cavalheiro, Aretusa Lopes; Costa, Debora Tacon da; Menezes, Ana Luiza Ferro de; Pereira, Janser Moura; Carvalho, Eliane Maria de

    2016-01-01

    Low temperatures and slow blood flow may result from peripheral neuropathy caused by leprosy, and the simple detection of cold fingers could already be a preliminary classification for these patients. To investigate whether infrared thermography would be able to measure this change in temperature in the hands of people with leprosy. The study assessed 17 leprosy patients who were under treatment at the National Reference Center for Sanitary Dermatology and Leprosy, Uberlândia/MG, and 15 people without leprosy for the control group. The infrared camera FLIR A325 and Therma CAM Researcher Professional 2.9 software were used to measure the temperature. The room was air-conditioned, maintaining the temperature at 25°C; the distance between the camera and the limb was 70 cm. The vasomotor reflex of patients was tested by a cold stress on the palm. The study showed a significant interaction between the clinical form of leprosy and temperature, where the control group and the borderline-borderline form revealed a higher initial temperature, while borderline-lepromatous and lepromatous leprosy showed a lower temperature. Regarding vasomotor reflex, lepromatous leprosy patients were unable to recover the initial temperature after cold stress, while those with the borderline-tuberculoid form not only recovered but exceeded the initial temperature. Thermography proved a potential tool to assist in the early detection of neuropathies, helping in the prevention of major nerve damage and the installation of deformities and disabilities that are characteristic of leprosy.

  8. An analytical model for the prediction of the dynamic response of premixed flames stabilized on a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.; Ghoniem, Ahmed F.

    2013-01-01

    The dynamic response of a premixed flame stabilized on a heat-conducting perforated plate depends critically on their coupled thermal interaction. The objective of this paper is to develop an analytical model to capture this coupling. The model

  9. Associations between Language Development and Skin Conductance Responses to Faces and Eye Gaze in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Stagg, Steven D.; Davis, Robert; Heaton, Pamela

    2013-01-01

    Attention to social stimuli is associated with language development, and arousal is associated with the increased viewing of stimuli. We investigated whether skin conductance responses (SCRs) are associated with language development in autism spectrum disorder (ASD): a population that shows abnormalities in both attention to others and language…

  10. Measuring the implementation of codes of conduct. An assessment method based on a process approach of the responsible organisation

    NARCIS (Netherlands)

    Nijhof, A.H.J.; Cludts, Stephan; Fisscher, O.A.M.; Laan, Albertus

    2003-01-01

    More and more organisations formulate a code of conduct in order to stimulate responsible behaviour among their members. Much time and energy is usually spent fixing the content of the code but many organisations get stuck in the challenge of implementing and maintaining the code. The code then

  11. Optimum Depth of Investigation and Conductivity Response Rejection of the Different Electromagnetic Devices Measuring Apparent Magnetic Susceptibility

    OpenAIRE

    Benech , Christophe; Marmet , Eric

    1999-01-01

    International audience; Electromagnetic susceptibility surveys are valuable for archaeological prospection owing to their ability to cover large areas of land. Their use, however, is often compromised by the conductivity influence of the soil and the limited investigation depth of the susceptibility response. To examine these constraints further, we compared the characteristics of two types of apparatus: coincident loop (e.g. Bartington MS2 field coil) and 'Slingram' instruments (EM38, SH3, C...

  12. Physiological and vascular responses to acute and chronic exercise in men and women with cardiovascular disease

    OpenAIRE

    Hughes, Sarah

    2013-01-01

    Study 1: Brachial artery flow-mediated dilation (FMD) using ultrasonography is used as a surrogate measure of coronary artery function. The purpose of this study was to i) assess the reliability of the PhD student in the use of ultrasonography to measure endothelial vasomotor function, and ii) develop and validate a custom-designed software to measure arterial diameter. The sonographer demonstrated excellent reliability in FMD assessment. Compared to in-built ultrasound calipers, the custom-d...

  13. Implicit Recognition of Familiar and Unfamiliar Faces in Schizophrenia: A Study of the Skin Conductance Response in Familiarity Disorders

    Directory of Open Access Journals (Sweden)

    Aurely Ameller

    2017-09-01

    Full Text Available ObjectiveFamiliarity is a subjective sensation that contributes to person recognition. This process is described as an emotion-based memory-trace of previous meetings and could be disrupted in schizophrenia. Consequently, familiarity disorders could be involved in the impaired social interactions observed in patients with schizophrenia. Previous studies have primarily focused on famous people recognition. Our aim was to identify underlying features, such as emotional disturbances, that may contribute to familiarity disorders in schizophrenia. We hypothesize that patients with familiarity disorders will exhibit a lack of familiarity that could be detected by a flattened skin conductance response (SCR.MethodThe SCR was recorded to test the hypothesis that emotional reactivity disturbances occur in patients with schizophrenia during the categorization of specific familiar, famous and unknown faces as male or female. Forty-eight subjects were divided into the following 3 matched groups with 16 subjects per group: control subjects, schizophrenic people with familiarity disorder, and schizophrenic people without familiarity disorders.ResultsEmotional arousal is reflected by the skin conductance measures. The control subjects and the patients without familiarity disorders experienced a differential emotional response to the specific familiar faces compared with that to the unknown faces. Nevertheless, overall, the schizophrenic patients without familiarity disorders showed a weaker response across conditions compared with the control subjects. In contrast, the patients with familiarity disorders did not show any significant differences in their emotional response to the faces, regardless of the condition.ConclusionOnly patients with familiarity disorders fail to exhibit a difference in emotional response between familiar and non-familiar faces. These patients likely emotionally process familiar faces similarly to unknown faces. Hence, the lower

  14. Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

    Science.gov (United States)

    Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

    2015-01-01

    Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

  15. Dielectric response and electric conductivity of ceramics obtained from BiFeO{sub 3} synthesized by microwave hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Chybczyńska, K.; Markiewicz, E., E-mail: ewamar@ifmpan.poznan.pl; Błaszyk, M.; Hilczer, B.; Andrzejewski, B.

    2016-06-25

    BiFeO{sub 3} powder which formed ball-like structures resembling flowers was obtained by microwave hydrothermal synthesis. The flowers were of a dozen or so μm in diameter and the thickness of the crystallites forming petals could be controlled. The material was characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. Dielectric response of ceramics obtained from the powder contained three extrinsic contributions, which could be correlated with the differences in temperature variation of the ac conductivity. The dielectric relaxation between 150 K and 300 K was related to reorientations of Fe{sup 3+}–Fe{sup 2+} dipoles and characterized by an activation energy of 0.4 eV, which was independent of the petal thickness. The dielectric and electric response in the range 300 K ÷ 450 K usually ascribed to the grain boundary and interfacial polarization effect was diffused and could not be characterized. Above 450 K the activation energy of dc conductivity was 1.73 eV and 1.52 eV for ceramics consisting of crystallites of mean thickness of 160 nm and 260 nm, respectively. The energies, which are considerably higher than those reported earlier for BFO nanoceramics, were discussed considering the interactions between oxygen vacancies and size scaled ferroelectric domain walls, which in BiFeO{sub 3} are associated with electrostatic potential steps. - Highlights: • BiFeO{sub 3} with controllable thickness of crystallites was synthesized hydrothermally. • The powder and ceramics obtained were characterized by XRD, SEM and XPS methods. • Dielectric response of the ceramics is correlated with the ac conductivity. • Size-scaled ferroelectric domains and oxygen vacancies interact above 450 K.

  16. Kaempferol enhances endothelium-dependent relaxation in the porcine coronary artery through activation of large-conductance Ca(2+) -activated K(+) channels.

    Science.gov (United States)

    Xu, Y C; Leung, S W S; Leung, G P H; Man, R Y K

    2015-06-01

    Kaempferol, a plant flavonoid present in normal human diet, can modulate vasomotor tone. The present study aimed to elucidate the signalling pathway through which this flavonoid enhanced relaxation of vascular smooth muscle. The effect of kaempferol on the relaxation of porcine coronary arteries to endothelium-dependent (bradykinin) and -independent (sodium nitroprusside) relaxing agents was studied in an in vitro organ chamber setup. The whole-cell patch-clamp technique was used to determine the effect of kaempferol on potassium channels in porcine coronary artery smooth muscle cells (PCASMCs). At a concentration without direct effect on vascular tone, kaempferol (3 × 10(-6) M) enhanced relaxations produced by bradykinin and sodium nitroprusside. The potentiation by kaempferol of the bradykinin-induced relaxation was not affected by N(ω)-nitro-L-arginine methyl ester, an inhibitor of NO synthase (10(-4) M) or TRAM-34 plus UCL 1684, inhibitors of intermediate- and small-conductance calcium-activated potassium channels, respectively (10(-6) M each), but was abolished by tetraethylammonium chloride, a non-selective inhibitor of calcium-activated potassium channels (10(-3) M), and iberiotoxin, a selective inhibitor of large-conductance calcium-activated potassium channel (KCa 1.1; 10(-7) M). Iberiotoxin also inhibited the potentiation by kaempferol of sodium nitroprusside-induced relaxations. Kaempferol stimulated an outward-rectifying current in PCASMCs, which was abolished by iberiotoxin. The present results suggest that, in smooth muscle cells of the porcine coronary artery, kaempferol enhanced relaxations caused by endothelium-derived and exogenous NO as well as those due to endothelium-dependent hyperpolarization. This vascular effect of kaempferol involved the activation of KCa 1.1 channels. © 2015 The British Pharmacological Society.

  17. The menopausal experience among indigenous women of Sarawak, Malaysia.

    Science.gov (United States)

    Syed Alwi, S A R; Lee, P Y; Awi, I; Mallik, P S; Md Haizal, M N

    2009-12-01

    To document the common menopausal symptoms and quality of life in indigenous women of Sarawak in Malaysia. A face-to-face interview using the Menopause-specific Quality of Life questionnaire was conducted with 276 indigenous Sarawakian women aged 40-65 years to determine the mean age of menopause and common symptoms (divided into vasomotor, psychosocial, physical and sexual domains) associated with menopause. The mean age at menopause of postmenopausal women was 50.78 +/- 2.47 years (range 47.3-58.2 years). The most common symptoms reported were aching in muscles and joints (82.6%), lack of energy (77.5%) and low backache (77.2%). The typical menopausal symptoms of hot flushes, night sweats, sweating and vaginal dryness were experienced by 42.4%, 34.8%, 29.7% and 49.3%, respectively of the women studied. Perimenopausal women (n = 114) experienced the most physical and psychosocial symptoms, while postmenopausal women (n = 102) experienced most sexual symptoms. Perimenopausal and postmenopausal women were reported to suffer more than premenopausal women (p < 0.001) within the four domains of symptoms (vasomotor, psychosocial, physical and sexual). The menopausal symptoms in this study correspond to those in other studies on Asian women but the prevalence of typical and classical menopausal symptoms was lower compared to studies on Caucasian women. The perimenopausal women had the most significant decrease in quality of life, followed by postmenopausal women and premenopausal women. Vasomotor symptoms had a predominant influence on the quality of life.

  18. Ultrafast Terahertz Conductivity of Photoexcited Nanocrystalline Silicon

    DEFF Research Database (Denmark)

    Cooke, David; MacDonald, A. Nicole; Hryciw, Aaron

    2007-01-01

    The ultrafast transient ac conductivity of nanocrystalline silicon films is investigated using time-resolved terahertz spectroscopy. While epitaxial silicon on sapphire exhibits a free carrier Drude response, silicon nanocrystals embedded in glass show a response that is best described by a class...... in the silicon nanocrystal films is dominated by trapping at the Si/SiO2 interface states, occurring on a 1–100 ps time scale depending on particle size and hydrogen passivation......The ultrafast transient ac conductivity of nanocrystalline silicon films is investigated using time-resolved terahertz spectroscopy. While epitaxial silicon on sapphire exhibits a free carrier Drude response, silicon nanocrystals embedded in glass show a response that is best described...

  19. Instruction in the responsible conduct of research: an inventory of programs and materials within CTSAs.

    Science.gov (United States)

    DuBois, James M; Schilling, Debie A; Heitman, Elizabeth; Steneck, Nicholas H; Kon, Alexander A

    2010-06-01

    The National Institutes of Health (NIH) require instruction in the responsible conduct of research (RCR) as a component of any Clinical and Translational Science Award (CTSA). The Educational Materials Group of the NIH CTSA Consortium's Clinical Research Ethics Key Function Committee (CRE-KFC) conducted a survey of the 38 institutions that held CTSA funding as of January 2009 to determine how they satisfy RCR training requirements. An 8-item questionnaire was sent by email to directors of the Clinical Research Ethics, the Educational and Career Development, and the Regulatory Knowledge cores. We received 78 completed surveys from 38 CTSAs (100%). We found that there is no unified approach to RCR training across CTSAs, many programs lack a coherent plan for RCR instruction, and most CTSAs have not developed unique instructional materials tailored to the needs of clinical and translational scientists. We recommend collaboration among CTSAs and across CTSA key function committees to address these weaknesses. We also requested that institutions send electronic copies of original RCR training materials to share among CTSAs via the CTSpedia website. Twenty institutions submitted at least one educational product. The CTSpedia now contains more than 90 RCR resources.

  20. Anomalous Thermal Conductivity and Magnetic Torque Response in the Honeycomb Magnet α -RuCl3

    Science.gov (United States)

    Leahy, Ian A.; Pocs, Christopher A.; Siegfried, Peter E.; Graf, David; Do, S.-H.; Choi, Kwang-Yong; Normand, B.; Lee, Minhyea

    2017-05-01

    We report on the unusual behavior of the in-plane thermal conductivity κ and torque τ response in the Kitaev-Heisenberg material α -RuCl3 . κ shows a striking enhancement with linear growth beyond H =7 T , where magnetic order disappears, while τ for both of the in-plane symmetry directions shows an anomaly at the same field. The temperature and field dependence of κ are far more complex than conventional phonon and magnon contributions, and require us to invoke the presence of unconventional spin excitations whose properties are characteristic of a field-induced spin-liquid phase related to the enigmatic physics of the Kitaev model in an applied magnetic field.

  1. Promoting responsible research conduct in a developing world ...

    African Journals Online (AJOL)

    2013-06-22

    Jun 22, 2013 ... from 51 countries, it contains 4 principles and 14 responsibilities and has been .... Likewise, all institutions must have an 'assurance' registered with the ... requirements and standards, via process auditing. Whether these .... Office for Human Research Protections, Health and Human Services, US Federal.

  2. Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

    Directory of Open Access Journals (Sweden)

    Christoph Bartneck

    Full Text Available Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

  3. Thermal Response of Cooled Silicon Nitride Plate Due to Thermal Conductivity Effects Analyzed

    Science.gov (United States)

    Baaklini, George Y.; Abdul-Aziz, Ali; Bhatt, Ramakrishna

    2003-01-01

    Lightweight, strong, tough high-temperature materials are required to complement efficiency improvements for next-generation gas turbine engines that can operate with minimum cooling. Because of their low density, high-temperature strength, and high thermal conductivity, ceramics are being investigated as materials to replace the nickelbase superalloys that are currently used for engine hot-section components. Ceramic structures can withstand higher operating temperatures and a harsh combustion environment. In addition, their low densities relative to metals help reduce component mass (ref. 1). To complement the effectiveness of the ceramics and their applicability for turbine engine applications, a parametric study using the finite element method is being carried out. The NASA Glenn Research Center remains very active in conducting and supporting a variety of research activities related to ceramic matrix composites through both experimental and analytical efforts (ref. 1). The objectives of this work are to develop manufacturing technology, develop a thermal and environmental barrier coating (TBC/EBC), develop an analytical modeling capability to predict thermomechanical stresses, and perform a minimal burner rig test on silicon nitride (Si3N4) and SiC/SiC turbine nozzle vanes under simulated engine conditions. Moreover, we intend to generate a detailed database of the material s property characteristics and their effects on structural response. We expect to offer a wide range of data since the modeling will account for other variables, such as cooling channel geometry and spacing. Comprehensive analyses have begun on a plate specimen with Si3N4 cooling holes.

  4. The effect of ethnicity on the vascular responses to cold exposure of the extremities

    OpenAIRE

    Maley, Matthew J.; Eglin, Clare M.; House, James R.; Tipton, Michael J.

    2014-01-01

    Purpose Cold injuries are more prevalent in individuals of African descent (AFD). Therefore, we investigated the effect of extremity cooling on skin blood flow (SkBF) and temperature (T sk) between ethnic groups. Methods Thirty males [10 Caucasian (CAU), 10 Asian (ASN), 10 AFD] undertook three tests in 30 °C air whilst digit T sk and SkBF were measured: (i) vasomotor threshold (VT) test—arm immersed in 35 °C water progressively cooled to 10 °C and rewarmed to 35 °C to identify vasoconstrictio...

  5. Test design requirements: Thermal conductivity probe testing

    International Nuclear Information System (INIS)

    Heath, R.E.

    1985-01-01

    This document establishes the test design requirements for development of a thermal conductivity probe test. The thermal conductivity probe determines in situ thermal conductivity using a line source transient heat conduction analysis. This document presents the rationale for thermal conductivity measurement using a thermal conductivity probe. A general test description is included. Support requirements along with design constraints are detailed to allow simple design of the thermal conductivity probe and test. The schedule and delivery requirements of the responsible test designer are also included. 7 refs., 1 fig

  6. Fairness decisions in response to emotions: a functional MRI study among criminal justice-involved boys with conduct disorder.

    Science.gov (United States)

    Klapwijk, Eduard T; Lelieveld, Gert-Jan; Aghajani, Moji; Boon, Albert E; van der Wee, Nic J A; Popma, Arne; Vermeiren, Robert R J M; Colins, Olivier F

    2016-04-01

    Research suggests that individuals with conduct disorder (CD) are marked by social impairments, such as difficulties in processing the affective reactions of others. Little is known, though, about how they make decisions during social interactions in response to emotional expressions of others. In this study, we therefore investigated the neural mechanisms underlying fairness decisions in response to communicated emotions of others in aggressive, criminal justice-involved boys with CD (N = 32) compared with typically developing (TD) boys (N = 33), aged 15-19 years. Participants received written emotional responses (angry, disappointed or happy) from peers in response to a previous offer and then had to make fairness decisions in a version of the Dictator Game. Behavioral results showed that CD boys did not make differential fairness decisions in response to the emotions, whereas the TD boys did show a differentiation and also responded more unfair to happy reactions than the CD boys. Neuroimaging results revealed that when receiving happy vs disappointed and angry reactions, the CD boys showed less activation than the TD boys in the temporoparietal junction and supramarginal gyrus, regions involved in perspective taking and attention. These results suggest that boys with CD have difficulties with processing explicit emotional cues from others on behavioral and neural levels. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  7. Bioabsorbable polymer-coated sirolimus-eluting stent implantation preserves coronary vasomotion: A DESSOLVE II trial sub-study.

    Science.gov (United States)

    Rusinaru, Dan; Vrolix, Mathias; Verheye, Stefan; Chowdhary, Saqib; Schoors, Danny; Di Mario, Carlo; Desmet, Walter; Donohoe, Dennis J; Ormiston, John A; Knape, Charlene; Bezerra, Hiram; Lansky, Alexandra; Wijns, William

    2015-12-01

    We studied coronary vasomotion in patients treated with the Mistent(®) absorbable polymer sirolimus-eluting stent (APSES) and in patients implanted with the Endeavor(®) zotarolimus-eluting stent (ZES). First generation (1st-gen) drug-eluting stents (DES) induce persistent vasomotor dysfunction in the treated coronary artery. It is unknown whether and to what extent the implantation of an absorbable polymer DES impairs coronary vasomotion. This sub-study of the DESSOLVE II trial included 19 APSES Mistent(®) and 10 ZES Endeavor(®) patients. Incremental atrial pacing and quantitative coronary angiography were used to assess vasomotion proximal and distal to the stent and in a reference segment at 9 months after implantation. Percent changes in vessel diameter with pacing versus baseline were calculated and compared. Vasomotor response of the APSES group was also compared with changes observed in a historical group of 17 patients implanted with a 1st-gen sirolimus-eluting stent (SES). Normal vasomotion (vasodilatation) was preserved and of comparable magnitude in the APSES and in the ZES group both proximally (P = 0.34) and distally (P = 0.38) to the stent. This finding was not observed in the 1st-gen SES group showing marked pacing-induced vasoconstriction at both stent edges (P absorbable polymer sirolimus-eluting stent is associated with preserved coronary vasomotion, comparable to that observed after implantation of the Endeavor(®) ZES, and distinct from 1st-gen SES which induce coronary vasomotor dysfunction. © 2015 Wiley Periodicals, Inc.

  8. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    International Nuclear Information System (INIS)

    Sim, Chol-Ho

    2016-01-01

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm

  9. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2016-02-15

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm.

  10. Computerized analysis of isometric tension studies provides important additional information about vasomotor activity

    Directory of Open Access Journals (Sweden)

    Vincent M.B.

    1997-01-01

    Full Text Available Concentration-response curves of isometric tension studies on isolated blood vessels are obtained traditionally. Although parameters such as Imax, EC50 and pA2 may be readily calculated, this method does not provide information on the temporal profile of the responses or the actual nature of the reaction curves. Computerized data acquisition systems can be used to obtain average data that represent a new source of otherwise inaccessible information, since early and late responses may be observed separately in detail

  11. Identification of induced and naturally occurring conductive hearing loss in mice using bone conduction.

    Science.gov (United States)

    Chhan, David; McKinnon, Melissa L; Rosowski, John J

    2017-03-01

    While many mouse models of hearing loss have been described, a significant fraction of the genetic defects in these models affect both the inner ear and middle ears. A common method used to separate inner-ear (sensory-neural) from middle-ear (conductive) pathologies in the hearing clinic is the combination of air-conduction and bone-conduction audiometry. In this report, we investigate the use of air- and bone-conducted evoked auditory brainstem responses to perform a similar separation in mice. We describe a technique by which we stimulate the mouse ear both acoustically and via whole-head vibration. We investigate the sensitivity of this technique to conductive hearing loss by introducing middle-ear lesions in normal hearing mice. We also use the technique to investigate the presence of an age-related conductive hearing loss in a common mouse model of presbycusis, the BALB/c mouse. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Conducting polymer coated neural recording electrodes

    Science.gov (United States)

    Harris, Alexander R.; Morgan, Simeon J.; Chen, Jun; Kapsa, Robert M. I.; Wallace, Gordon G.; Paolini, Antonio G.

    2013-02-01

    Objective. Neural recording electrodes suffer from poor signal to noise ratio, charge density, biostability and biocompatibility. This paper investigates the ability of conducting polymer coated electrodes to record acute neural response in a systematic manner, allowing in depth comparison of electrochemical and electrophysiological response. Approach. Polypyrrole (Ppy) and poly-3,4-ethylenedioxythiophene (PEDOT) doped with sulphate (SO4) or para-toluene sulfonate (pTS) were used to coat iridium neural recording electrodes. Detailed electrochemical and electrophysiological investigations were undertaken to compare the effect of these materials on acute in vivo recording. Main results. A range of charge density and impedance responses were seen with each respectively doped conducting polymer. All coatings produced greater charge density than uncoated electrodes, while PEDOT-pTS, PEDOT-SO4 and Ppy-SO4 possessed lower impedance values at 1 kHz than uncoated electrodes. Charge density increased with PEDOT-pTS thickness and impedance at 1 kHz was reduced with deposition times up to 45 s. Stable electrochemical response after acute implantation inferred biostability of PEDOT-pTS coated electrodes while other electrode materials had variable impedance and/or charge density after implantation indicative of a protein fouling layer forming on the electrode surface. Recording of neural response to white noise bursts after implantation of conducting polymer-coated electrodes into a rat model inferior colliculus showed a general decrease in background noise and increase in signal to noise ratio and spike count with reduced impedance at 1 kHz, regardless of the specific electrode coating, compared to uncoated electrodes. A 45 s PEDOT-pTS deposition time yielded the highest signal to noise ratio and spike count. Significance. A method for comparing recording electrode materials has been demonstrated with doped conducting polymers. PEDOT-pTS showed remarkable low fouling during

  13. Management of osteoporosis and menopausal symptoms: focus on bazedoxifene/conjugated estrogen combination

    Directory of Open Access Journals (Sweden)

    Mirkin S

    2013-08-01

    Full Text Available Sebastian Mirkin,1 James H Pickar21Pfizer Inc, Collegeville, PA, 2Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY, USAAbstract: Loss of estrogen production in women during menopause results in a state of estrogen deficiency which has been associated with multiple problems, including vasomotor symptoms, symptoms of vulvovaginal atrophy, bone loss, and difficulties with sleep, mood, memory, and sexual activity. The only treatment option currently available to address multiple postmenopausal symptoms in women with an intact uterus is estrogen/progestin-containing hormone therapy (HT. Concerns surrounding side effects and published data regarding the association of HT with the increased risk for breast cancer have induced a decrease in the number of women seeking, initiating, and continuing this type of therapy. A combination containing bazedoxifene and conjugated estrogens (BZA/CE maintains the established benefits of estrogen therapy for treatment of postmenopausal vasomotor symptoms, vulvovaginal atrophy, and osteoporosis, while certain estrogenic effects, such as stimulation of the uterus and breast, are antagonized without the side effects associated with HT. BZA/CE has been evaluated in a series of multicenter, randomized, double-blind, placebo-controlled, and active-controlled Phase III trials known as the Selective estrogens, Menopause, And Response to Therapy (SMART trials. BZA/CE demonstrated clinically meaningful improvements in vasomotor symptoms, vulvovaginal atrophy, and a protective effect on the skeleton. These clinical benefits were associated with an acceptable safety profile and an improved tolerability compared with HT. BZA/CE showed a favorable safety profile on the breast, endometrium, and ovaries. The incidence of venous thromboembolism was low and the risk does not appear to be any greater than for CE alone or BZA alone or greater than HT. The incidence of coronary heart disease and

  14. Kaempferol enhances endothelium-dependent relaxation in the porcine coronary artery through activation of large-conductance a2+-activated K+ channels

    Science.gov (United States)

    Xu, Y C; Leung, S W S; Leung, G P H; Man, R Y K

    2015-01-01

    Background and Purpose Kaempferol, a plant flavonoid present in normal human diet, can modulate vasomotor tone. The present study aimed to elucidate the signalling pathway through which this flavonoid enhanced relaxation of vascular smooth muscle. Experimental Approach The effect of kaempferol on the relaxation of porcine coronary arteries to endothelium-dependent (bradykinin) and -independent (sodium nitroprusside) relaxing agents was studied in an in vitro organ chamber setup. The whole-cell patch-clamp technique was used to determine the effect of kaempferol on potassium channels in porcine coronary artery smooth muscle cells (PCASMCs). Key Results At a concentration without direct effect on vascular tone, kaempferol (3 × 10−6 M) enhanced relaxations produced by bradykinin and sodium nitroprusside. The potentiation by kaempferol of the bradykinin-induced relaxation was not affected by Nω-nitro-L-arginine methyl ester, an inhibitor of NO synthase (10−4 M) or TRAM-34 plus UCL 1684, inhibitors of intermediate- and small-conductance calcium-activated potassium channels, respectively (10−6 M each), but was abolished by tetraethylammonium chloride, a non-selective inhibitor of calcium-activated potassium channels (10−3 M), and iberiotoxin, a selective inhibitor of large-conductance calcium-activated potassium channel (KCa1.1; 10−7 M). Iberiotoxin also inhibited the potentiation by kaempferol of sodium nitroprusside-induced relaxations. Kaempferol stimulated an outward-rectifying current in PCASMCs, which was abolished by iberiotoxin. Conclusions and Implications The present results suggest that, in smooth muscle cells of the porcine coronary artery, kaempferol enhanced relaxations caused by endothelium-derived and exogenous NO as well as those due to endothelium-dependent hyperpolarization. This vascular effect of kaempferol involved the activation of KCa1.1 channels. PMID:25652142

  15. Determination of head conductivity frequency response in vivo with optimized EIT-EEG.

    Science.gov (United States)

    Dabek, Juhani; Kalogianni, Konstantina; Rotgans, Edwin; van der Helm, Frans C T; Kwakkel, Gert; van Wegen, Erwin E H; Daffertshofer, Andreas; de Munck, Jan C

    2016-02-15

    Electroencephalography (EEG) benefits from accurate head models. Dipole source modelling errors can be reduced from over 1cm to a few millimetres by replacing generic head geometry and conductivity with tailored ones. When adequate head geometry is available, electrical impedance tomography (EIT) can be used to infer the conductivities of head tissues. In this study, the boundary element method (BEM) is applied with three-compartment (scalp, skull and brain) subject-specific head models. The optimal injection of small currents to the head with a modular EIT current injector, and voltage measurement by an EEG amplifier is first sought by simulations. The measurement with a 64-electrode EEG layout is studied with respect to three noise sources affecting EIT: background EEG, deviations from the fitting assumption of equal scalp and brain conductivities, and smooth model geometry deviations from the true head geometry. The noise source effects were investigated depending on the positioning of the injection and extraction electrode and the number of their combinations used sequentially. The deviation from equal scalp and brain conductivities produces rather deterministic errors in the three conductivities irrespective of the current injection locations. With a realistic measurement of around 2 min and around 8 distant distinct current injection pairs, the error from the other noise sources is reduced to around 10% or less in the skull conductivity. The analysis of subsequent real measurements, however, suggests that there could be subject-specific local thinnings in the skull, which could amplify the conductivity fitting errors. With proper analysis of multiplexed sinusoidal EIT current injections, the measurements on average yielded conductivities of 340 mS/m (scalp and brain) and 6.6 mS/m (skull) at 2 Hz. From 11 to 127 Hz, the conductivities increased by 1.6% (scalp and brain) and 6.7% (skull) on the average. The proper analysis was ensured by using recombination of

  16. Conductive properties of methanogenic biofilms.

    Science.gov (United States)

    Li, Cheng; Lesnik, Keaton Larson; Liu, Hong

    2018-02-01

    Extracellular electron transfer between syntrophic partners needs to be efficiently maintained in methanogenic environments. Direct extracellular electron transfer via electrical current is an alternative to indirect hydrogen transfer but requires construction of conductive extracellular structures. Conductive mechanisms and relationship between conductivity and the community composition in mixed-species methanogenic biofilms are not well understood. The present study investigated conductive behaviors of methanogenic biofilms and examined the correlation between biofilm conductivity and community composition between different anaerobic biofilms enriched from the same inoculum. Highest conductivity observed in methanogenic biofilms was 71.8±4.0μS/cm. Peak-manner response of conductivity upon changes over a range of electrochemical potentials suggests that electron transfer in methanogenic biofilms occurs through redox driven super-exchange. The strong correlation observed between biofilm conductivity and Geobacter spp. in the metabolically diverse anaerobic communities suggests that the efficiency of DEET may provide pressure for microbial communities to select for species that can produce electrical conduits. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Code of conduct for scientists (abstract)

    International Nuclear Information System (INIS)

    Khurshid, S.J.

    2011-01-01

    The emergence of advanced technologies in the last three decades and extraordinary progress in our knowledge on the basic Physical, Chemical and Biological properties of living matter has offered tremendous benefits to human beings but simultaneously highlighted the need of higher awareness and responsibility by the scientists of 21 century. Scientist is not born with ethics, nor science is ethically neutral, but there are ethical dimensions to scientific work. There is need to evolve an appropriate Code of Conduct for scientist particularly working in every field of Science. However, while considering the contents, promulgation and adaptation of Codes of Conduct for Scientists, a balance is needed to be maintained between freedom of scientists and at the same time some binding on them in the form of Code of Conducts. The use of good and safe laboratory procedures, whether, codified by law or by common practice must also be considered as part of the moral duties of scientists. It is internationally agreed that a general Code of Conduct can't be formulated for all the scientists universally, but there should be a set of 'building blocks' aimed at establishing the Code of Conduct for Scientists either as individual researcher or responsible for direction, evaluation, monitoring of scientific activities at the institutional or organizational level. (author)

  18. Fluid conductivity sensor

    International Nuclear Information System (INIS)

    Miller, F. M.

    1985-01-01

    Apparatus for sensing the electrical conductivity of fluid which can be used to detonate an electro explosive device for operating a release mechanism for uncoupling a parachute canopy from its load upon landing in water. An operating network connected to an ignition capacitor and to a conductivity sensing circuit and connected in controlling relation to a semiconductor switch has a voltage independent portion which controls the time at which the semiconductor switch is closed to define a discharge path to detonate the electro explosive device independent of the rate of voltage rise on the ignition capacitor. The operating network also has a voltage dependent portion which when a voltage of predetermined magnitude is developed on the conductivity sensing circuit in response to fluid not having the predetermined condition of conductivity, the voltage dependent portion closes the semiconductor switch to define the discharge path when the energy level is insufficient to detonate the electro explosive device. A regulated current source is connected in relation to the conductivity sensing circuit and to the electrodes thereof in a manner placing the circuit voltage across the electrodes when the conductivity of the fluid is below a predetermined magnitude so that the sensing circuit does not respond thereto and placing the circuit voltage across the sensing circuit when the conductivity of the fluid is greater than a predetermined magnitude. The apparatus is operated from a battery, and the electrodes are of dissimilar metals so selected and connected relative to the polarity portions of the circuit to maximize utilization of the battery output voltage

  19. 36 CFR 905.735-201 - General standards of conduct.

    Science.gov (United States)

    2010-07-01

    ... economy; (4) Losing complete independence or impartiality; (5) Making a Government decision outside... CORPORATION STANDARDS OF CONDUCT Conduct and Responsibilities of Employees § 905.735-201 General standards of conduct. (a) All employees shall conduct themselves on the job so as to efficiently discharge the work of...

  20. Synthesis, characterization and AC conductivity studies of silver doped conducting polyaniline/graphene/SrTiO3 composites

    Science.gov (United States)

    Vinay, K.; Shivakumar, K.; Ravikiran, Y. T.; Revanasiddappa, M.

    2018-05-01

    The present work is an investigation of ac conduction behaviour and dielectric response of Polyaniline/Ag/Graphene/SrTiO3 (PAGS) composite prepared by in-situ chemical oxidative interfacial polymerization using (NH4)2S2O8 as an oxidising agent at 0-5°C. The structural characterization of the samples was examined using FT-IR and XRD techniques. The ac conductivity and dielectric response of synthesized polymer composites were investigated at room temperature in the frequency range varying from 5 × 101 - 5 × 106 Hz using HIOKI make 3532-50 LCR Hi-tester. The ac conductivity increases with increase in frequency and follows the regular trend, the real dielectric constant (ɛ') and imaginary dielectric constant (ɛ'') decreases with increase in frequency and exhibits almost zero dielectric loss at higher frequencies, which suggests that the composite is a lossless material at frequencies beyond 3Hz.

  1. Conductivity bound from dirty black holes

    Energy Technology Data Exchange (ETDEWEB)

    Bitaghsir Fadafan, Kazem, E-mail: bitaghsir@shahroodut.ac.ir

    2016-11-10

    We propose a lower bound of the dc electrical conductivity in strongly disordered, strongly interacting quantum field theories using holography. We study linear response of black holes with broken translational symmetry in Einstein–Maxwell-dilaton theories of gravity. Using the generalized Stokes equations at the horizon, we derive the lower bound of the electrical conductivity for the dual two dimensional disordered field theory.

  2. Hall conductance and topological invariant for open systems.

    Science.gov (United States)

    Shen, H Z; Wang, W; Yi, X X

    2014-09-24

    The Hall conductivity given by the Kubo formula is a linear response of quantum transverse transport to a weak electric field. It has been intensively studied for quantum systems without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formulism to deal with this issue for topological insulators. The Hall conductance of a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory developed for open systems in this paper. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.

  3. The perceptual trap: Experimental and modelling examples of soil moisture, hydraulic conductivity and response units in complex subsurface settings.

    Science.gov (United States)

    Jackisch, Conrad; Demand, Dominic; Allroggen, Niklas; Loritz, Ralf; Zehe, Erwin

    2017-04-01

    In order to discuss hypothesis testing in hydrology, the question of the solid foundation of such tests has to be answered. But how certain are we about our measurements of the components of the water balance and the states and dynamics of the complex systems? What implicit assumptions or bias are already embedded in our perception of the processes? How can we find light in the darkness of heterogeneity? We will contribute examples from experimental findings, modelling approaches and landscape analysis to the discussion. Example soil moisture and the soil continuum: The definition of soil moisture as fraction of water in the porous medium assumes locally well-mixed conditions. Moreover, a unique relation of soil water retention presumes instant local thermodynamic equilibrium in the pore water arrangement. We will show findings from soil moisture responses to precipitation events, from irrigation experiments, and from a model study of initial infiltration velocities. The results highlight, that the implicit assumption relating soil moisture state dynamics with actual soil water flow is biased towards the slow end of the actual velocity distribution and rather blind for preferential flow acting in a very small proportion of the pore space. Moreover, we highlight the assumption of a well-defined continuum during the extrapolation of point-scale measurements and why spatially and temporally continuous observation techniques of soil water states are essential for advancing our understanding and development of subsurface process theories. Example hydraulic conductivity: Hydraulic conductivity lies at the heart of hydrological research and modelling. Its values can range across several orders of magnitude at a single site alone. Yet, we often consider it a crisp, effective parameter. We have conducted measurements of soil hydraulic conductivity in the lab and in the field. Moreover, we assessed infiltration capacity and conducted plot-scale irrigation experiments to

  4. Variations in body morphology explain sex differences in thermoeffector function during compensable heat stress.

    Science.gov (United States)

    Notley, Sean R; Park, Joonhee; Tagami, Kyoko; Ohnishi, Norikazu; Taylor, Nigel A S

    2017-05-01

    What is the central question of this study? Can sex-related differences in cutaneous vascular and sudomotor responses be explained primarily by variations in the ratio between body surface area and mass during compensable exercise that elicits equivalent heat-loss requirements and mean body temperature changes across participants? What is the main finding and its importance? Mass-specific surface area was a significant determinant of vasomotor and sudomotor responses in men and women, explaining 10-48% of the individual thermoeffector variance. Nonetheless, after accounting for changes in mean body temperature and morphological differences, sex explained only 5% of that inter-individual variability. It was concluded that sex differences in thermoeffector function are morphologically dependent, but not sex dependent. Sex is sometimes thought to be an independent modulator of cutaneous vasomotor and sudomotor function during heat exposure. Nevertheless, it was hypothesized that, when assessed during compensable exercise that evoked equal heat-loss requirements across participants, sex differences in those thermoeffectors would be explained by variations in the ratio between body surface area and mass (specific surface area). To evaluate that possibility, vasomotor and sudomotor functions were assessed in 60 individuals (36 men and 24 women) with widely varying (overlapping) specific surface areas (range, 232.3-292.7 and 241.2-303.1 cm 2  kg -1 , respectively). Subjects completed two trials in compensable conditions (28°C, 36% relative humidity) involving rest (20 min) and steady-state cycling (45 min) at fixed, area-specific metabolic heat-production rates (light, ∼135 W m -2 ; moderate, ∼200 W m -2 ). Equivalent heat-loss requirements and mean body temperature changes were evoked across participants. Forearm blood flow and vascular conductance were positively related to specific surface area during light work in men (r = 0.67 and r = 0

  5. Problem gamblers are hyposensitive to wins: an analysis of skin conductance responses during actual gambling on electronic gaming machines.

    Science.gov (United States)

    Lole, Lisa; Gonsalvez, Craig J; Barry, Robert J; Blaszczynski, Alex

    2014-06-01

    Physiological arousal is purportedly a key determinant in the development and maintenance of gambling behaviors, with problem gambling conceptualized in terms of abnormal autonomic responses. Theoretical conceptualizations of problem gambling are discordant regarding the nature of deficit in this disorder; some accounts posit that problem gamblers are hypersensitive to reward, and others that they are hyposensitive to reward and/or punishment. Previous research examining phasic electrodermal responses in gamblers has been limited to laboratory settings, and reactions to real gaming situations need to be examined. Skin conductance responses (SCRs) to losses, wins, and losses disguised as wins (LDWs) were recorded from 15 problem gamblers (PGs) and 15 nonproblem gamblers (NPGs) while they wagered their own money during electronic gaming machine play. PGs demonstrated significantly reduced SCRs to reward. SCRs to losses and LDWs did not differ for either PGs or NPGs. This hyposensitivity to wins may reflect abnormalities in incentive processing, and may represent a potential biological marker for problem gambling. Copyright © 2014 Society for Psychophysiological Research.

  6. Thermal conductivity of sputtered amorphous Ge films

    International Nuclear Information System (INIS)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka

    2014-01-01

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids

  7. Effects of diffuse light on radiation use efficiency depend on the response of stomatal conductance to dynamic light intensity

    Directory of Open Access Journals (Sweden)

    Tao eLi

    2016-02-01

    Full Text Available The stimulating effect of diffuse light on radiation use efficiency (RUE of crops is often explained by the more homogeneous spatial light distribution, while rarely considering differences in temporal light distribution at leaf level. This study investigated whether diffuse light effects on crop RUE can be explained by dynamic responses of leaf photosynthesis to temporal changes of photosynthetic photon flux density (PPFD.Two Anthurium andreanum cultivars (‘Pink Champion’ and ‘Royal Champion’ were grown in two glasshouses covered by clear (control and diffuse glass, with similar light transmission. On clear days, diffusing the light resulted in less temporal fluctuations of PPFD. Stomatal conductance (gs varied strongly in response to transient PPFD in ‘Royal Champion’, whereas it remained relatively constant in ‘Pink Champion’. Instantaneous net leaf photosynthesis (Pn in both cultivars approached steady state Pn in diffuse light treatment. In control treatment this only occurred in ‘Pink Champion’. These cultivar differences were reflected by a higher RUE (8% in ‘Royal Champion’ in diffuse light treatment compared with control, whereas no effect on RUE was observed in ‘Pink Champion’. We conclude that the stimulating effect of diffuse light on RUE depends on the stomatal response to temporal PPFD fluctuations, which response is cultivar dependent.

  8. Further evidence for a fluid pathway during bone conduction auditory stimulation.

    Science.gov (United States)

    Sohmer, Haim; Freeman, Sharon

    2004-07-01

    This study was designed to evaluate the suggestion that during bone vibrator stimulation on skull bone (bone conduction auditory stimulation), a major connection between the site of the bone vibrator and the inner ear is a fluid pathway. A series of experiments were conducted on pairs of animals (rats or guinea pigs). The cranial cavities of each pair of animals were coupled by means of a saline filled plastic tube sealed into a craniotomy in the skull of each animal. In response to bone conduction click stimulation to the skull bone of animal I, auditory nerve-brainstem evoked responses could be recorded in animal II. Various procedures showed that these responses were initiated in animal II in response to audio-frequency sound pressures generated within the cranial cavity of animal I by the bone conduction stimulation and transferred to the cranial cavity of animal II through the fluid in the plastic tube: they were not responses to air conducted sounds generated by the bone vibrator, were not induced in animal II by vibrations conveyed to it by the plastic tube and were not electrically conducted activity from animal I. Exposing the fluid in the tube to air was not accompanied by any change in threshold. These experiments confirm that during bone conduction stimulation on the skull, audio-frequency sound pressures (alternating condensations and rarefactions) can be conveyed by a fluid pathway to the cochlea and stimulate it.

  9. Responses to Three USARIEM Job Analysis Questionnaires (JAQ’s) Conducted with Cannon Crewmembers and Fire Support Specialists (MOS’s 13B and 13F)

    Science.gov (United States)

    2016-10-26

    USARIEM TECHNICAL REPORT T17-01 RESPONSES TO THREE USARIEM JOB ANALYSIS QUESTIONNAIRES (JAQ’S) CONDUCTED WITH CANNON CREWMEMBERS AND...Illuminator Designator JAQ Job Analysis Questionnaire LLDR Lightweight Laser Designator Rangefinder LMTV Light Medium Tactical Vehicle MOS Military...U.S. Army Research Institute of Environmental Medicine (USARIEM) designed and conducted a total of three web- administered job analysis

  10. Research ethics I: Responsible conduct of research (RCR)--historical and contemporary issues pertaining to human and animal experimentation.

    Science.gov (United States)

    Horner, Jennifer; Minifie, Fred D

    2011-02-01

    In this series of articles--Research Ethics I, Research Ethics II, and Research Ethics III--the authors provide a comprehensive review of the 9 core domains for the responsible conduct of research (RCR) as articulated by the Office of Research Integrity. In Research Ethics I, they present a historical overview of the evolution of RCR in the United States then examine the evolution of human and animal experimentation from the birth of scientific medicine through World War II to the present day. They relied on authoritative documents, both historical and contemporary, insightful commentary, and empirical research in order to identify current issues and controversies of potential interest to both faculty and students. The authors have written this article from a historical perspective because they think all readers interested in RCR should appreciate how the history of science and all the good--and harm--it has produced can inform how researchers practice responsible research in the 21st century and beyond.

  11. Soil permittivity response to bulk electrical conductivity for selected soil water sensors

    Science.gov (United States)

    Bulk electrical conductivity can dominate the low frequency dielectric loss spectrum in soils, masking changes in the real permittivity and causing errors in estimated water content. We examined the dependence of measured apparent permittivity (Ka) on bulk electrical conductivity in contrasting soil...

  12. Auditory steady-state response thresholds in adults with conductive and mild to moderate sensorineural hearing loss.

    Science.gov (United States)

    Hosseinabadi, Reza; Jafarzadeh, Sadegh

    2015-01-01

    The Auditory steady state response (ASSR) provides a frequency-specific and automatic assessment of hearing sensitivity and is used in infants and difficult-to-test adults. The aim of this study was to compare the ASSR thresholds among various types (normal, conductive, and sensorineural), degree (normal, mild, and moderate), and configuration (flat and sloping) of hearing sensitivity, and measuring the cutoff point between normal condition and hearing loss for different frequencies. This clinical trial was performed in Iran and included patients who were referred from Ear, Nose, and Throat Department. A total of 54 adults (27 with sensorineural hearing loss, 17 with conductive hearing losses, and 10 with normal hearing) were randomly chosen to participate in our study. The type and degree of hearing loss were determined through testing by otoscopy, tympanometry, acoustic reflex, and pure tone audiometry. Then the ASSR was tested at carrier frequencies of 500, 1000, 2000, and 4000 Hz. The ASSR accurately estimates the behavioral thresholds as well as flat and sloping configurations. There was no correlation between types of hearing loss and difference of behavioral and ASSR thresholds (P = 0.69). The difference between ASSR and behavioral thresholds decreased as severity of hearing loss increased. The 40, 35, 30, and 35 dB could be considered as cutoffs between normal hearing and hearing loss for 500, 1000, 2000, and 4000 Hz, respectively. The ASSR can accurately predict the degree and configuration of hearing loss and discriminate the normal hearing from mild or moderate hearing loss and mild from moderate hearing loss, except for 500 Hz. The Air-conducted ASSR could not define the type of hearing loss.

  13. Optical conductivity and electronic Raman response of cuprate superconductors

    International Nuclear Information System (INIS)

    Vanyolos, A.; Dora, B.; Virosztek, A.

    2010-01-01

    We present the results of detailed analytical calculations for the in-plane optical conductivity and the electronic Raman susceptibility in quasi two-dimensional systems possessing a ground state with two competing order parameters: a d-wave density wave (dDW) and d-wave superconductor (dSC). In the coexisting dDW+dSC phase we determine the frequency dependence of these correlation functions in the presence of randomly distributed non-magnetic impurities in the unitary limit.

  14. Vitamin C Deficiency Reduces Muscarinic Receptor Coronary Artery Vasoconstriction and Plasma Tetrahydrobiopterin Concentration in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Gry Freja Skovsted

    2017-07-01

    Full Text Available Vitamin C (vitC deficiency is associated with increased cardiovascular disease risk, but its specific interplay with arteriolar function is unclear. This study investigates the effect of vitC deficiency in guinea pigs on plasma biopterin status and the vasomotor responses in coronary arteries exposed to vasoconstrictor/-dilator agents. Dunkin Hartley female guinea pigs (n = 32 were randomized to high (1500 mg/kg diet or low (0 to 50 mg/kg diet vitC for 10–12 weeks. At euthanasia, coronary artery segments were dissected and mounted in a wire-myograph. Vasomotor responses to potassium, carbachol, sodium nitroprusside (SNP, U46619, sarafotoxin 6c (S6c and endothelin-1 (ET-1 were recorded. Plasma vitC and tetrahydrobiopterin were measured by HPLC. Plasma vitC status reflected the diets with deficient animals displaying reduced tetrahydrobiopterin. Vasoconstrictor responses to carbachol were significantly decreased in vitC deficient coronary arteries independent of their general vasoconstrictor/vasodilator capacity (p < 0.001. Moreover, in vitC deficient animals, carbachol-induced vasodilator responses correlated with coronary artery diameter (p < 0.001. Inhibition of cyclooxygenases with indomethacin increased carbachol-induced vasoconstriction, suggesting an augmented carbachol-induced release of vasodilator prostanoids. Atropine abolished carbachol-induced vasomotion, supporting a specific muscarinic receptor effect. Arterial responses to SNP, potassium, S6c, U46619 and ET-1 were unaffected by vitC status. The study shows that vitC deficiency decreases tetrahydrobiopterin concentrations and muscarinic receptor mediated contraction in coronary arteries. This attenuated vasoconstrictor response may be linked to altered production of vasoactive arachidonic acid metabolites and reduced muscarinic receptor expression/signaling.

  15. Infection-induced coronary dysfunction and systemic inflammation in piglets are dampened in hypercholesterolemic milieu

    DEFF Research Database (Denmark)

    Birck, Malene M.; Pesonen, Erkki; Odermarsky, Michal

    2011-01-01

    The synergism of infection with conventional cardiovascular risk factors in atherosclerosis is much debated. We hypothesized that coronary arterial injury correlates with infection recurrence and pathogen burden and is further aggravated by hypercholesterolemia. Forty-two Göttingen minipigs were ...... = 0.08). Coinfection of piglets appears to be associated with more pronounced coronary muscarinic vasomotor dysfunction. In monoinfected animals, use of chol-diet seems to dampen both coronary dysfunction and systemic inflammation induced by infection....... assigned to repeated intratracheal inoculation of PBS, Chlamydia pneumoniae (Cpn), or both Cpn and influenza virus at 8, 11, and 14 wk of age. Animals were fed either standard or 2% cholesterol diet (chol-diet). At 19 wk of age coronary vasomotor responses to acetylcholine (ACh) and adenosine were assessed...... in vivo and blood and tissue samples were collected. Nonparametric tests were used to compare the groups. In cholesterol-fed animals, total cholesterol/HDL was significantly increased in infected animals compared with noninfected animals [3.13 (2.17–3.38) vs. 2.03 (1.53–2.41), respectively; P = 0.01]. C...

  16. The role of anxiety in cortisol stress response and cortisol recovery in boys with oppositional defiant disorder/conduct disorder.

    Science.gov (United States)

    Schoorl, Jantiene; Rijn, Sophie van; Wied, Minet de; van Goozen, Stephanie; Swaab, Hanna

    2016-11-01

    Children with antisocial and aggressive behaviors have been found to show abnormal neurobiological responses to stress, specifically impaired cortisol stress reactivity. The role of individual characteristics, such as comorbid anxiety, in the stress response is far less studied. Furthermore, this study extended previous studies in that not only baseline and reactivity to a psychosocial stressor were examined, but also recovery from a stressor. These three phases of cortisol could be impacted differentially in boys with oppositional defiant disorder/conduct disorder (ODD/CD) with (+ANX) and without anxiety (-ANX). The results revealed that cortisol patterns in response to psychosocial stress were different for boys with ODD/CD+ANX (n=32), ODD/CD-ANX (n=22) and non-clinical controls (NC) (n=34), with age range of 7.8-12.9 years. The ODD/CD-ANX group showed lower overall cortisol levels than the NC group. When considering the three phases of cortisol separately, the ODD/CD-ANX group had lower baseline cortisol levels relative to the other groups, whereas the ODD/CD+ANX showed an impaired cortisol recovery response. Within those with ODD/CD, callous-unemotional traits were predictive of high baseline cortisol levels. Also, anxiety predicted high baseline and recovery cortisol levels, whereas a high number of CD symptoms predicted reduced cortisol stress reactivity. These results clearly indicate that comorbid anxiety is an important factor in explaining differences in stress response profiles in boys with ODD/CD; although boys with CD/ODD are generally characterized by an impaired cortisol stress response, we found that those with comorbid anxiety showed impaired cortisol recovery, whereas those without anxiety showed reduced baseline cortisol levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Investigating the Inter-Tube Conduction Mechanism in Polycarbonate Nanocomposites Prepared with Conductive Polymer-Coated Carbon Nanotubes

    KAUST Repository

    Ventura, Isaac Aguilar

    2015-12-16

    A well-known strategy to improve the electrical conductivity of polymers is to dope them with high-aspect-ratio and conductive nanoparticles such as carbon nanotubes (CNTs). However, these nanocomposites also exhibit undesirable properties such as damage-sensitive and history-dependent conductivity because their macroscopic electrical conductivity is largely determined by the tunneling effect at the tube/tube interface. To reduce these issues, new nanocomposites have been developed with CNTs that have been coated with a conductive layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT/PSS). It has been posited that the insulating region between the CNTs is replaced by a conductive polymer bridge; this has not been proven up to now. We propose here to investigate in-depth how the macroscopic conductivity of these materials is changing when (1) varying the frequency of the electrical loading (impedance spectroscopy), (2) varying the mechanical hydrostatic pressure, and (3) varying the voltage of the electrical loading. The response is systematically compared to the one of conventional carbon nanotube/polycarbonate (CNT/PC) nanocomposites so we can clarify how efficiently the tunneling effect is suppressed from these composites. The objective is to elucidate further the mechanism for conduction in such material formulations.

  18. Greater efficiency of water use in poplar clones having a delayed response of mesophyll conductance to drought.

    Science.gov (United States)

    Théroux Rancourt, Guillaume; Éthier, Gilbert; Pepin, Steeve

    2015-02-01

    Improvement of water use efficiency is a key objective to improve the sustainability of cultivated plants, especially fast growing species with high water consumption like poplar. It is well known that water use efficiency (WUE) varies considerably among poplar genotypes, and it was recently suggested that the use of the mesophyll-to-stomatal conductance ratio (gm/gs) would be an appropriate trait to improve WUE. The responses of 7-week-old cuttings of four hybrid poplar clones and one native Balsam poplar (Populus balsamifera L.) to a water stress-recovery cycle were examined to evaluate the relation between the gm/gs ratio and transpiration efficiency (TE), a leaf-level component of WUE. A contrasting gs response to water stress was observed among the five clones, from stomatal closure early on during soil drying up to limited closure in Balsam poplar. However in the hybrids, the decline in gm was consistently delayed by a few days compared with gs. Moreover, in the most water use-efficient hybrids, the recovery following rehydration occurred faster for gm than for gs. Thus, the delay in the response of gm to drought and its faster recovery upon rewatering increased the gm/gs of the hybrids and this ratio scaled positively with TE. Our results support the use of the gm/gs ratio to select genotypes with improved WUE, and the notion that breeding strategies focusing mainly on stomatal responses to soil drying should also look for a strong curvilinearity between net carbon assimilation rate and gs, the indication of a significant increase in gm/gs in the earlier stages of stomatal closure. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Teragawa, Hiroki; Kihara, Yasuki [Hiroshima University Graduate School of Biomedical Sciences, Department of Cardiovascular Medicine, Hiroshima (Japan); Morita, Koichi; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka [Hiroshima Heiwa Clinic, Hiroshima (Japan); Chayama, Kazuaki [Hiroshima University Graduate School of Biomedical Sciences, Department of Molecular Science and Medicine, Hiroshima (Japan)

    2010-02-15

    Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 {+-} 0.99 vs. 3.38 {+-} 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

  20. Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

    International Nuclear Information System (INIS)

    Teragawa, Hiroki; Kihara, Yasuki; Morita, Koichi; Tamaki, Nagara; Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka; Chayama, Kazuaki

    2010-01-01

    Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 ± 0.99 vs. 3.38 ± 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

  1. Potential role of gabapentin and extended- release gabapentin in the management of menopausal hot flashes

    Directory of Open Access Journals (Sweden)

    Yadav M

    2013-08-01

    Full Text Available Manisha Yadav, Judith Volkar Center for Specialized Women’s Health, Cleveland Clinic Foundation, Cleveland, Ohio, USA Abstract: About 80% of postmenopausal women experience vasomotor symptoms, such as hot flashes and night sweats – symptoms that are associated with sleep disruption and can lead to fatigue and mood changes. Moreover, hot flashes can be embarrassing for women, causing difficulties at work and in their social lives. Many therapies have been advocated for relief of vasomotor symptoms, but only hormone therapy has been US Food and Drug Administration approved. However, after the Women's Health Initiative Study suggested that there was a correlation between hormone therapy and increased risk for breast cancer and cardiovascular events, many women stopped taking hormone therapy, and many do not want to initiate it. Hormone therapy is also contraindicated in certain women, such as those with a history of hormone-stimulated cancer like breast and uterine cancer. Gabapentin (Neurontin has shown efficacy in relieving vasomotor symptoms and is used as off-label for this indication. A new extended-release formulation of gabapentin has also shown efficacy in treating hot flashes and improving sleep quality with possibly fewer side effects than regular gabapentin. Keywords: Hot flushes, vasomotor symptoms, postmenopausal, hormone-sensitive cancer, non-hormonal therapy, gastric-retentive, Breeze

  2. An Item Response Theory Analysis of DSM-IV Conduct Disorder

    Science.gov (United States)

    Gelhorn, Heather; Hartman, Christie; Sakai, Joseph; Mikulich-Gilbertson, Susan; Stallings, Michael; Young, Susan; Rhee, Soo; Corley, Robin; Hewitt, John; Hopfer, Christian; Crowley, Thomas

    2009-01-01

    Interviews with over 3,000 adolescents were made to evaluate the extent to which DSM-IV criteria characterizes the range of severity of adolescent antisocial behavior within and across sex. The DSM-IV conduct disorder (CD) criteria are a useful indicator of severe adolescent antisocial behavior but some CD criteria display sex bias.

  3. Aggression in Children with Conduct Problems and Callous-Unemotional Traits: Social Information Processing and Response to Peer Provocation.

    Science.gov (United States)

    Helseth, Sarah A; Waschbusch, Daniel A; King, Sara; Willoughby, Michael T

    2015-11-01

    Callous/unemotional traits (CU) moderate children's conduct problems (CP) in numerous domains, including social functioning. The present study examined whether CU traits also moderate the aggressiveness of children's social information processing (SIP) and responses to varying intensities of peer provocation. Sixty elementary school-age children (46 males) were grouped into those without CP or CU (controls, n = 32), those with CP but not CU (CP-only; n = 14), and those with both CP and CU (CPCU, n = 14). Participants completed a task that measured two aspects of SIP (response generation and hostile attribution bias) and a computerized reaction time task (CRTT) that measured behavior, affect, and communication before and after provocation under instrumental and hostile aggressive conditions. Children with CPCU generated more aggressive responses than controls on measures of SIP. On the CRTT, all children exhibited reactive aggression following high provocation, but only children with CPCU exhibited proactive aggression, and reactive aggression following low provocation; no differences in affect were found. In a series of exploratory analyses, CPCU children communicated antisocially, while CP-only communicated prosocially. Finally, children with CPCU did not seem to hold a grudge following the final instance of provocation, instead gradually returning to baseline like their non-CU peers. These distinct social cognitive and behavioral profiles hint at different etiologies of CP and CPCU, underscoring the variability of aggression in these populations.

  4. Brain-derived neurotrophic factor ameliorates brain stem cardiovascular dysregulation during experimental temporal lobe status epilepticus.

    Directory of Open Access Journals (Sweden)

    Ching-Yi Tsai

    Full Text Available BACKGROUND: Status epilepticus (SE is an acute, prolonged epileptic crisis with a mortality rate of 20-30%; the underlying mechanism is not completely understood. We assessed the hypothesis that brain stem cardiovascular dysregulation occurs during SE because of oxidative stress in rostral ventrolateral medulla (RVLM, a key nucleus of the baroreflex loop; to be ameliorated by brain-derived neurotrophic factor (BDNF via an antioxidant action. METHODOLOGY/PRINCIPAL FINDINGS: In a clinically relevant experimental model of temporal lobe SE (TLSE using Sprague-Dawley rats, sustained hippocampal seizure activity was accompanied by progressive hypotension that was preceded by a reduction in baroreflex-mediated sympathetic vasomotor tone; heart rate and baroreflex-mediated cardiac responses remained unaltered. Biochemical experiments further showed concurrent augmentation of superoxide anion, phosphorylated p47(phox subunit of NADPH oxidase and mRNA or protein levels of BDNF, tropomyosin receptor kinase B (TrkB, angiotensin AT1 receptor subtype (AT1R, nitric oxide synthase II (NOS II or peroxynitrite in RVLM. Whereas pretreatment by microinjection bilaterally into RVLM of a superoxide dismutase mimetic (tempol, a specific antagonist of NADPH oxidase (apocynin or an AT1R antagonist (losartan blunted significantly the augmented superoxide anion or phosphorylated p47(phox subunit in RVLM, hypotension and the reduced baroreflex-mediated sympathetic vasomotor tone during experimental TLSE, pretreatment with a recombinant human TrkB-Fc fusion protein or an antisense bdnf oligonucleotide significantly potentiated all those events, alongside peroxynitrite. However, none of the pretreatments affected the insignificant changes in heart rate and baroreflex-mediated cardiac responses. CONCLUSIONS/SIGNIFICANCE: We conclude that formation of peroxynitrite by a reaction between superoxide anion generated by NADPH oxidase in RVLM on activation by AT1R and NOS II

  5. 50 CFR 600.225 - Rules of conduct.

    Science.gov (United States)

    2010-10-01

    ..., and Council employees are subject to most Federal criminal statutes covering bribery, conflict-of... are responsible for maintaining high standards of ethical conduct among themselves, their staffs, and...

  6. Hopping models for ion conduction in noncrystals

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Schrøder, Thomas

    2007-01-01

    semiconductors). These universalities are subject of much current interest, for instance interpreted in the context of simple hopping models. In the present paper we first discuss the temperature dependence of the dc conductivity in hopping models and the importance of the percolation phenomenon. Next......, the experimental (quasi)universality of the ac conductivity is discussed. It is shown that hopping models are able to reproduce the experimental finding that the response obeys time-temperature superposition, while at the same time a broad range of activation energies is involved in the conduction process. Again...

  7. Significance of CaV3.2 T-type Ca2+ channels for pressure- and flow-dependent vasomotor responses in rat and mouse mesenteric small arteries

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Björling, K.; Hansen, Pernille B. Lærkegaard

    RNA was similar in WT vs. CaV3.2-/- mice. CONCLUSION: FMVD responses appear to rely on an endothelium-dependent hyperpolarization in rat small mesenteric arteries. CaV3.2 channels are negative feedback modulators of myogenic tone in small mesenteric artery in young mice. The age-dependent decline in CaV3...... in young CaV3.2-/- mice (8-15 weeks) vs. age-matched WT mice (Pyoung WT mice, the CaV3.2 blocker NiCl2 (30 µM) significantly enhanced myogenic tone (P... was not seen (N=4). In young and old CaV3.2-/- mice no effects of NiCl2 were observed. The FMVD response in rat mesenteric arteries was not blocked by L-NAME, but was almost abolished by the SKCa/IKCa channel blockers apamin/TRAM-34 (50 nM/1 µM) (P

  8. The insular cortex: relationship to skin conductance responses to facial expression of emotion in temporal lobe epilepsy.

    Science.gov (United States)

    Banks, Sarah J; Bellerose, Jenny; Douglas, Danielle; Jones-Gotman, Marilyn

    2014-03-01

    The insula plays an important role both in emotion processing and in the generation of epileptic seizures. In the current study we examined thickness of insular cortices and bilateral skin conductance responses (SCR) in healthy subjects in addition to a small number of patients with temporal lobe epilepsy. SCR measures arousal and is used to assess non-conscious responses to emotional stimuli. We used two emotion tasks, one explicitly about emotion and the other implicit. The explicit task required judgments about emotions being expressed in photographs of faces, while the implicit one required judgments about the age of the people in the photographs. Patients and healthy differed in labeling neutral faces, but not other emotions. They also differed in their SCR to emotions, though the profile depended on which hand the recordings were from. Finally, we found relationships between the thickness of the insula and SCR to each task: in the healthy group the thickness of the left insula was related to SCR to the emotion-labeling task; in the patient group it was between the thickness of the right insula and SCR in the age-labeling task. These patterns were evident only for the right hand recordings, thus underscoring the importance of bilateral recordings.

  9. Structure of conduction electrons on polysilanes

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Tsuneki [Hokkaido Univ., Sapporo (Japan); Kumagai, Jun

    1998-10-01

    The orbital structures of conduction electrons on permethylated oligosilane, Si{sub 2n}(CH{sub 3}){sub 2n+2}(n = 2 - 8), and poly(cyclohexylmethylsilane) have been determined by the electron spin-echo envelope modulation signals of the radical anions of these silanes in a deuterated rigid matrix at 77 K. The conduction electron on permethylated oligosilane is delocalized over the entire main chain, whereas that on poly(cyclohexylmethylsilane) is localized on a part of the main chain composed of about six Si atoms. Quantum-chemical calculations suggest that Anderson localization due to fluctuation of {sigma} conjugation by conformational disorder of the main chain is responsible for the localization of both the conduction electron and the hole. (author)

  10. Responses to hyperthermia. Optimizing heat dissipation by convection and evaporation: Neural control of skin blood flow and sweating in humans.

    Science.gov (United States)

    Smith, Caroline J; Johnson, John M

    2016-04-01

    Under normothermic, resting conditions, humans dissipate heat from the body at a rate approximately equal to heat production. Small discrepancies between heat production and heat elimination would, over time, lead to significant changes in heat storage and body temperature. When heat production or environmental temperature is high the challenge of maintaining heat balance is much greater. This matching of heat elimination with heat production is a function of the skin circulation facilitating heat transport to the body surface and sweating, enabling evaporative heat loss. These processes are manifestations of the autonomic control of cutaneous vasomotor and sudomotor functions and form the basis of this review. We focus on these systems in the responses to hyperthermia. In particular, the cutaneous vascular responses to heat stress and the current understanding of the neurovascular mechanisms involved. The available research regarding cutaneous active vasodilation and vasoconstriction is highlighted, with emphasis on active vasodilation as a major responder to heat stress. Involvement of the vasoconstrictor and active vasodilator controls of the skin circulation in the context of heat stress and nonthermoregulatory reflexes (blood pressure, exercise) are also considered. Autonomic involvement in the cutaneous vascular responses to direct heating and cooling of the skin are also discussed. We examine the autonomic control of sweating, including cholinergic and noncholinergic mechanisms, the local control of sweating, thermoregulatory and nonthermoregulatory reflex control and the possible relationship between sudomotor and cutaneous vasodilator function. Finally, we comment on the clinical relevance of these control schemes in conditions of autonomic dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Temperature and frequency response of conductivity in Ag2S doped chalcogenide glassy semiconductor

    Science.gov (United States)

    Ojha, Swarupa; Das, Anindya Sundar; Roy, Madhab; Bhattacharya, Sanjib

    2018-06-01

    The electric conductivity of chalcogenide glassy semiconductor xAg2S-(1-x)(0.5S-0.5Te) has been presented here as a function of temperature and frequency. Formation of different nanocrystallites has been confirmed from X-ray diffraction study. It is also noteworthy that average size of nanocrystallites decreases with the increase of dislocation density. Dc conductivity data have been interpreted using Mott's model and Greaves's model in low and high temperature regions respectively. Ac conductivity above the room temperature has been analyzed using Meyer-Neldel (MN) conduction rule. It is interestingly noted that Correlated Barrier Hopping (CBH) model is the most appropriate conduction mechanism for x = 0.35, where pairs of charge carrier are considered to hop over the potential barrier between the sites via thermal activation. To interpret experimental data for x = 0.45, modified non-overlapping small polaron tunnelling (NSPT) model is supposed to be appropriate model due to tunnelling through grain boundary. The conductivity spectra at various temperatures have been analyzed using Almond-West Formalism (power law model). Scaling of conductivity spectra reveals that electrical relaxation process of charge carriers (polaron) is temperature independent but depends upon the composition of the present chalcogenide glassy system.

  12. Effect of lanthanum substitution on dielectric relaxation, impedance response, conducting and magnetic properties of strontium hexaferrite

    Energy Technology Data Exchange (ETDEWEB)

    Want, Basharat, E-mail: bawant@kashmiruniversity.ac.in; Bhat, Bilal Hamid; Ahmad, Bhat Zahoor

    2015-04-05

    Highlights: • The substitution of La affects the dielectric and magnetic properties of strontium hexaferrite. • The electric behaviour of the compound follows the Koop’s phenomenological theory. • The impedance study shows the role of grain boundaries to the electric properties of the compound. • The substitution of La to strontium hexaferrite reduces the resistive nature of grain boundaries. - Abstract: Lanthanum strontium hexaferrite Sr{sub 1−x}La{sub x}Fe{sub 12}O{sub 19} (x = 0, 0.08, 0.13 , 0.18) has been successfully synthesized by using citrate-precursor method and characterized by different techniques. The X-ray diffraction results revealed that the sample is crystalline in nature and is of single phase with the space group P63/mmc. The dielectric, conducting and impedance related studies have been carried out as a function of frequency and concentration of lanthanum in the frequency ranges of 20 Hz–3 MHz. Impedance studies were performed in the frequency domain to distinguish between bulk and grain boundary contributions of the material to the overall dielectric response. The electric response of the material was also modeled by an equivalent circuit and different circuit parameters were calculated. Magnetic characterization of the material was also performed and the effect of lanthanum concentration was studied. The hysteresis loop obtained from the magnetometer showed that with the increase of lanthanum concentration, the saturation magnetisation decreases while as coercivity increases.

  13. Strategy for developing and conducting nuclear emergency exercises

    International Nuclear Information System (INIS)

    2007-01-01

    Emergency situations demand that actions be taken by responsible organisations and individuals at the site of the emergency and at the local, national and international levels to mitigate the impact on people and the environment. Effective emergency response requires development and implementation of emergency plans and procedures; established arrangements at the local, national and international levels; acquisition and maintenance of resources (funding, equipment and personnel); training of personnel; conduct of exercises; and a 'feedback programme' whereby improvements to the emergency management system are made based on lessons identified from exercises and actual events. A means for demonstrating the effectiveness of an emergency programme is through the conduct of exercises. Exercises demonstrate the effectiveness of plans, procedures, training and equipment; adequacy of response arrangements and resources; capabilities of response personnel in performing their assigned tasks; ability of individuals and organisations to work together; and provide a forum for exploring and testing revisions, modifications, and new and/or proposed changes to any emergency programme element in near realistic situations. Exercises may range in scope from small-scale drills to large-scale national or international exercises. There is clear benefit to organisations in supporting, developing and conducting well-managed exercises. Exercising is a resource-intensive tool; however, it is a critical tool for enhancing performance, testing arrangements and identifying areas for improvement. A thoroughly developed strategy should therefore be in place to ensure maximum value from an exercise programme. This report contributes to the good practice and management of exercise programmes by providing a strategy for improving the value of planning, conducting, participating in and/or supporting exercises. The OECD/NEA International Nuclear Emergency Exercise (INEX) series undertaken over the

  14. Detecting the differences in responses of stomatal conductance to moisture stresses between deciduous shrubs and Artemisia subshrubs.

    Science.gov (United States)

    Gao, Qiong; Yu, Mei; Zhou, Chan

    2013-01-01

    Shrubs and subshrubs can tolerate wider ranges of moisture stresses in both soil and air than other plant life forms, and thus represent greater nonlinearity and uncertainty in ecosystem physiology. The objectives of this paper are to model shrub/subshrub stomatal conductance by synthesizing the field leaf gas exchanges data of 24 species in China, in order to detect the differences between deciduous shrubs and Artemisia subshrubs in their responses of stomatal conductance to changes in the moisture stresses. We revised a model of stomatal conductance by incorporating the tradeoff between xylem hydraulic efficiency and cavitation loss risk. We then fit the model at the three hierarchical levels: global (pooling all data as a single group), three functional groups (deciduous non-legume shrubs, deciduous legume shrubs, and subshrubs in Artemisia genus), and individual observations (species × sites). Bayesian inference with Markov Chain Monte Carlo method was applied to obtain the model parameters at the three levels. We found that the model at the level of functional groups is a significant improvement over that at the global level, indicating the significant differences in the stomatal behavior among the three functional groups. The differences in tolerance and sensitivities to changes in moisture stresses are the most evident between the shrubs and the subshrubs: The two shrub groups can tolerate much higher soil water stress than the subshrubs. The analysis at the observation level is also a significant improvement over that at the functional group level, indicating great variations within each group. Our analysis offered a clue for the equivocal issue of shrub encroachment into grasslands: While the invasion by the shrubs may be irreversible, the dominance of subshrubs, due to their lower resistance and tolerance to moisture stresses, may be put down by appropriate grassland management.

  15. The dynamical conductance of graphene tunnelling structures

    International Nuclear Information System (INIS)

    Zhang Huan; Chan, K S; Lin Zijing

    2011-01-01

    The dynamical conductances of graphene tunnelling structures were numerically calculated using the scattering matrix method with the interaction effect included in a phenomenological approach. The overall single-barrier dynamical conductance is capacitative. Transmission resonances in the single-barrier structure lead to dips in the capacitative imaginary part of the response. This is different from the ac responses of typical semiconductor nanostructures, where transmission resonances usually lead to inductive peaks. The features of the dips depend on the Fermi energy. When the Fermi energy is below half of the barrier height, the dips are sharper. When the Fermi energy is higher than half of the barrier height, the dips are broader. Inductive behaviours can be observed in a double-barrier structure due to the resonances formed by reflection between the two barriers.

  16. The dynamical conductance of graphene tunnelling structures.

    Science.gov (United States)

    Zhang, Huan; Chan, K S; Lin, Zijing

    2011-12-16

    The dynamical conductances of graphene tunnelling structures were numerically calculated using the scattering matrix method with the interaction effect included in a phenomenological approach. The overall single-barrier dynamical conductance is capacitative. Transmission resonances in the single-barrier structure lead to dips in the capacitative imaginary part of the response. This is different from the ac responses of typical semiconductor nanostructures, where transmission resonances usually lead to inductive peaks. The features of the dips depend on the Fermi energy. When the Fermi energy is below half of the barrier height, the dips are sharper. When the Fermi energy is higher than half of the barrier height, the dips are broader. Inductive behaviours can be observed in a double-barrier structure due to the resonances formed by reflection between the two barriers.

  17. Shear-induced changes of electrical conductivity in suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Crawshaw, John; Meeten, Gerald [Schlumberger Cambridge Research, Cambridge (United Kingdom)

    2006-12-15

    The effect of shear on electrical conductivity (rheo-conduction) is studied to give information about particle behaviour in suspensions. Past work is reviewed, and expressions are derived for the rheo-conduction of a suspension of nonconducting spheroids in a conducting matrix for current flow, parallel and normal to the suspension flow direction. A simple apparatus to study rheo-conduction in pipe flow is described, and measurements of steady and time-dependent effects are reported for various suspensions of colloidal particles. Suspensions of anisometric rod- and platelike particles at low concentrations showed rheo-conductive changes of sign, magnitude and relaxation that were consistent with the particle shape, concentration and interactions. The rheo-conductive response decreased with increasing volume fraction for platelike kaolinite particles, attributed to orientational jamming. Spherical latex particles gave unexpected rheo-conductive changes consistent with shear disruption of a conductive network of particles. It is concluded that rheo-conduction measurements are a useful adjunct to conventional rheometry. (orig.)

  18. Low thermal conductivity skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Fleurial, J P; Caillat, T; Borshchevsky, A

    1997-07-01

    Recent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Both n-type and p-type conductivity samples have been obtained, using several preparation techniques. Associated with a low hole effective mass, very high carrier mobilities, low electrical resistivities and moderate Seebeck coefficients are obtained in p-type skutterudites. For a comparable doping level, the carrier mobilities of n-type samples are about an order of magnitude lower than the values achieved on p-type samples. However, the much larger electron effective masses and Seebeck coefficients on p-type samples. However, the much larger electron effective masses and Seebeck coefficients make n-type skutterudite promising candidates as well. Unfortunately, the thermal conductivities of the binary skutterudites compounds are too large, particularly at low temperatures, to be useful for thermoelectric applications. Several approaches to the reduction of the lattice thermal conductivity in skutterudites are being pursued: heavy doping, formation of solid solutions and alloys, study of novel ternary and filled skutterudite compounds. All those approaches have already resulted in skutterudite compositions with substantially lower thermal conductivity values in these materials. Recently, superior thermoelectric properties in the moderate to high temperature range were achieved for compositions combining alloying and filling of the skutterudite structure. Experimental results and mechanisms responsible for low thermal conductivity in skutterudites are discussed.

  19. A prospective randomized comparative study of the effects of intranasal and transdermal 17 β-estradiol on postmenopausal symptoms and vaginal cytology

    Directory of Open Access Journals (Sweden)

    Odabasi A

    2007-01-01

    Full Text Available Context: Investigating the adverse effects of oral hormone replacement therapy (HRT, the clinical effectiveness of alternative combinations and route of administrations. Aim: To compare the effects of intranasal and transdermal 17β-estradiol combined with vaginal progesterone on vasomotor symptoms and vaginal cytology. Settings and Design: A 12-week, prospective, randomized comparative study was conducted between July 2005 and September 2006. Materials and Methods: Eighty postmenopausal women aged between 42-57 years, who had scores of ≥1.7 on the menopause rating scale-I (MRS-I items "1-6", were randomly assigned to receive intranasal (300 µg/day, n =40 or transdermal (50 µg/day, n =40 17β-estradiol continuously. All patients also received a vaginal progesterone gel twice weekly. Vasomotor symptoms were evaluated at weeks 0, 4, 8 and 12. Vaginal maturation index (VMI was evaluated at weeks 0 and 12 of the study. Statistical Analyses: The Mann-Whitney U and the Wilcoxon tests were used. P < 0.05 was regarded as significant. Results: Thirty-two women in the intranasal and 29 women in the transdermal group completed the study. The total score of the MRS, the sum-scores of Factor 1 "HOT FLUSHES" and Factor 2 "PSYCHE" significantly decreased in both groups at week 4. Factor 3 "ATROPHY" scores significantly decreased only in the transdermal group at week 12. The VMI showed no changes within and between the two groups at the end of the study. Conclusion: Intranasal and transdermal 17β-estradiol combined with vaginal progesterone gel as a continuous HRT caused a similar decrease in vasomotor symptoms but did not have any significant effect on VMI after 12 weeks of treatment in this study population.

  20. Responsible Code of Conduct for the Life Science and Dual-Use Research

    International Nuclear Information System (INIS)

    Bokan, S.

    2007-01-01

    The potential threat from misuse of current and future Dual-Use research in the field of NBC Defense is challenge to which scientific community must respond. The rapid advances in the life sciences and the worldwide growth of biotechnology industry only add urgency of this task. Code of conduct is formal statement of values and professional practices of a group of individuals with a common focus, either an occupation, academic field, or social doctrine. Codes of conduct can help to reduce the risk that scientific research will be misused. 'Dual-use' is a term often used in politics and diplomacy to refer to technology which can be used for both peaceful and military aims, usually in regard to the proliferation of nuclear weapons. Dual-use information and 'know-how' in the field of NBC defense are covered under the Export control regimes. Nearly all WMD production equipment is 'dual-use' and only very large capacity equipment is export controlled. Research in the life sciences, including NBC defense research must be conducted safely, securely, and ethically. Development of an international harmonized regime for control of biological and chemical warfare agents within and between laboratories and facilities is very important. This paper will present very important consideration of the content, promulgation and adoption of codes of conduct for scientists in the field of NBC research, for inducing of discussion between scientists into group of CBMTS members with aim how improve protection of sensitive research results and information in the field of NBC Defense sciences. (author)

  1. The responsibility of technology. Weighting goods - risk assessment - codes of conduct

    International Nuclear Information System (INIS)

    Lenk, H.; Maring, M.

    1991-01-01

    Under the heading 'The responsibility of technology' nineteen authors contribute to the following topics: Basic questions of weighting 'goods' relating to resources, the relationship of technical possibilities and (self)restraint of individuals and collectives, striving for knowledge and appropriate limits, possibilities of directing and influencing technology and questions concerning (the limits of) individual and collective responsibility. Dealt with in more detail are: The assessment of technical risks and uncertainties from an ethical and legal point of view, problems in nuclear research and technology illustrated by the example of Chernobyl, information technology, and the influence of the press when presenting technology matters. (orig./HSCH) [de

  2. Development of a Novel Bone Conduction Verification Tool Using a Surface Microphone: Validation With Percutaneous Bone Conduction Users.

    Science.gov (United States)

    Hodgetts, William; Scott, Dylan; Maas, Patrick; Westover, Lindsey

    2018-03-23

    To determine if a newly-designed, forehead-mounted surface microphone would yield equivalent estimates of audibility when compared to audibility measured with a skull simulator for adult bone conduction users. Data was analyzed using a within subjects, repeated measures design. There were two different sensors (skull simulator and surface microphone) measuring the same hearing aid programmed to the same settings for all subjects. We were looking for equivalent results. Twenty-one adult percutaneous bone conduction users (12 females and 9 males) were recruited for this study. Mean age was 54.32 years with a standard deviation of 14.51 years. Nineteen of the subjects had conductive/mixed hearing loss and two had single-sided deafness. To define audibility, we needed to establish two things: (1) in situ-level thresholds at each audiometric frequency in force (skull simulator) and in sound pressure level (SPL; surface microphone). Next, we measured the responses of the preprogrammed test device in force on the skull simulator and in SPL on the surface mic in response to pink noise at three input levels: 55, 65, and 75 dB SPL. The skull simulator responses were converted to real head force responses by means of an individual real head to coupler difference transform. Subtracting the real head force level thresholds from the real head force output of the test aid yielded the audibility for each audiometric frequency for the skull simulator. Subtracting the SPL thresholds from the surface microphone from the SPL output of the test aid yielded the audibility for each audiometric frequency for the surface microphone. The surface microphone was removed and retested to establish the test-retest reliability of the tool. We ran a 2 (sensor) × 3 (input level) × 10 (frequency) mixed analysis of variance to determine if there were any significant main effects and interactions. There was a significant three-way interaction, so we proceeded to explore our planned comparisons

  3. Role of the body self and self-esteem in experiencing the intensity of menopausal symptoms.

    Science.gov (United States)

    Włodarczyk, Małgorzata; Dolińska-Zygmunt, Grażyna

    2017-10-29

    The aim of the study was to test differences in self-esteem and strength of the body self, body image, comfort with closeness with others and body protection among women reporting high and low intensity of psychological, vasomotor and somatic symptoms of menopause. The sample included 201 women aged 45-55 years. The Menopause Symptom List was used to test the intensity of menopausal symptoms, the Body Self Questionnaire was used to diagnose the body self, and the Rosenberg Self-Esteem Scale was used to examine participants'levels of self-esteem. Differences between women experiencing high and low intensity of symptoms were analyzed using Student's t-test for independent samples. Women experiencing high-intensity psychological, vasomotor and somatic symptoms of menopause showed significantly lower self-esteem and poorer body-self functioning in all its dimensions except for body protection. Women experiencing high-intensity psychological, vasomotor and somatic symptoms of menopause demonstrated poorer functioning of the body self and lower self-esteem.

  4. Thermal Conductivity of Carbon Nanotubes Embedded in Solids

    Institute of Scientific and Technical Information of China (English)

    CAO Bing-Yang; HOU Quan-Wen

    2008-01-01

    @@ A carbon-nanotube-atom fixed and activated scheme of non-equilibrium molecular dynamics simulations is put forward to extract the thermal conductivity of carbon nanotubes (CNTs) embedded in solid argon. Though a 6.5% volume fraction of CNTs increases the composite thermal conductivity to about twice as much as that of the pure basal material, the thermal conductivity of CNTs embedded in solids is found to be decreased by 1/8-1/5with reference to that of pure ones. The decrease of the intrinsic thermal conductivity of the solid-embedded CNTs and the thermal interface resistance are demonstrated to be responsible for the results.

  5. Regional cerebral blood flow in childhood headache

    International Nuclear Information System (INIS)

    Roach, E.S.; Stump, D.A.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured in 16 cranial regions in 23 children and adolescents with frequent headaches using the non-invasive Xenon-133 inhalation technique. Blood flow response to 5% carbon dioxide (CO2) was also determined in 21 patients, while response to 50% oxygen was measured in the two patients with hemoglobinopathy. Included were 10 patients with a clinical diagnosis of migraine, 4 with musculoskeletal headaches, and 3 with features of both types. Also studied were 2 patients with primary thrombocythemia, 2 patients with hemoglobinopathy and headaches, 1 patient with polycythemia, and 1 with headaches following trauma. With two exceptions, rCBF determinations were done during an asymptomatic period. Baseline rCBF values tended to be higher in these young patients than in young adults done in our laboratory. Localized reduction in the expected blood flow surge after CO2 inhalation, most often noted posteriorly, was seen in 8 of the 13 vascular headaches, but in none of the musculoskeletal headache group. Both patients with primary thrombocythemia had normal baseline flow values and altered responsiveness to CO2 similar to that seen in migraineurs; thus, the frequently reported headache and transient neurologic signs with primary thrombocythemia are probably not due to microvascular obstruction as previously suggested. These data support the concept of pediatric migraine as a disorder of vasomotor function and also add to our knowledge of normal rCBF values in younger patients. Demonstration of altered vasomotor reactivity to CO2 could prove helpful in children whose headache is atypical

  6. Creating an infrastructure for training in the responsible conduct of research: the University of Pittsburgh's experience.

    Science.gov (United States)

    Barnes, Barbara E; Friedman, Charles P; Rosenberg, Jerome L; Russell, Joanne; Beedle, Ari; Levine, Arthur S

    2006-02-01

    In response to public concerns about the consequences of research misconduct, academic institutions have become increasingly cognizant of the need to implement comprehensive, effective training in the responsible conduct of research (RCR) for faculty, staff, students, and external collaborators. The ability to meet this imperative is challenging as universities confront declining financial resources and increasing complexity of the research enterprise. The authors describe the University of Pittsburgh's design, implementation, and evaluation of a Web-based, institution-wide RCR training program called Research and Practice Fundamentals (RPF). This project, established in 2000, was embedded in the philosophy, organizational structure, and technology developed through the Integrated Advanced Information Management Systems grant from the National Library of Medicine. Utilizing a centralized, comprehensive approach, the RPF system provides an efficient mechanism for deploying content to a large, diverse cohort of learners and supports the needs of research administrators by providing access to information about who has successfully completed the training. During its first 3 years of operation, the RPF served over 17,000 users and issued more than 38,000 training certificates. The 18 modules that are currently available address issues required by regulatory mandates and other content areas important to the research community. RPF users report high levels of satisfaction with content and ease of using the system. Future efforts must explore methods to integrate non-RCR education and training into a centralized, cohesive structure. The University of Pittsburgh's experience with the RPF demonstrates the importance of developing an infrastructure for training that is comprehensive, scalable, reliable, centralized, affordable, and sustainable.

  7. The New Multi-Ministry Response to Conduct Problems: A SWOT Analysis

    Science.gov (United States)

    Stanley, Peter

    2008-01-01

    "The Inter-agency Plan for Conduct Disorder/Severe Antisocial Behaviour 2007-2012" (Ministry of Social Development, 2007) is assessed according to the SWOT dimensions of strengths, weaknesses, opportunities and threats. The document is one of the most important statements for the social services in New Zealand because of the primacy that…

  8. Differential effects of androgens on coronary blood flow regulation and arteriolar diameter in intact and castrated swine

    Directory of Open Access Journals (Sweden)

    O’Connor Erin K

    2012-05-01

    Full Text Available Abstract Background Low endogenous testosterone levels have been shown to be a risk factor for the development of cardiovascular disease and cardiovascular benefits associated with testosterone replacement therapy are being advocated; however, the effects of endogenous testosterone levels on acute coronary vasomotor responses to androgen administration are not clear. The objective of this study was to compare the effects of acute androgen administration on in vivo coronary conductance and in vitro coronary microvascular diameter in intact and castrated male swine. Methods Pigs received intracoronary infusions of physiologic levels (1–100 nM of testosterone, the metabolite 5α-dihydrotestosterone, and the epimer epitestosterone while left anterior descending coronary blood flow and mean arterial pressure were continuously monitored. Following sacrifice, coronary arterioles were isolated, cannulated, and exposed to physiologic concentrations (1–100 nM of testosterone, 5α-dihydrotestosterone, and epitestosterone. To evaluate effects of the androgen receptor on acute androgen dilation responses, real-time PCR and immunohistochemistry for androgen receptor were performed on conduit and resistance coronary vessels. Results In vivo, testosterone and 5α-dihydrotestosterone produced greater increases in coronary conductance in the intact compared to the castrated males. In vitro, percent maximal dilation of microvessels was similar between intact and castrated males for testosterone and 5α-dihydrotestosterone. In both studies epitestosterone produced significant increases in conductance and microvessel diameter from baseline in the intact males. Androgen receptor mRNA expression and immunohistochemical staining were similar in intact and castrated males. Conclusions Acute coronary vascular responses to exogenous androgen administration are increased by endogenous testosterone, an effect unrelated to changes in androgen receptor expression.

  9. Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients with Conductive and Sensorineural Hearing Loss and a Group with Vestibular Schawannoma.

    Science.gov (United States)

    Mahdi, Parvane; Amali, Amin; Pourbakht, Akram; Karimi Yazdi, Alireza; Bassam, Ali

    2013-06-01

    Vestibular evoked myogenic potential (VEMP) has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC) stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients. We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants. In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05). However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025). In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87%) of the 32 ears using the AC method, whereas all (100%) displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS), 2 (50.00%) had neither AC-VEMP nor BC-VEMP. Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

  10. Gender-related asymmetric brain vasomotor response to color stimulation: a functional transcranial Doppler spectroscopy study.

    Science.gov (United States)

    Njemanze, Philip C

    2010-11-30

    The present study was designed to examine the effects of color stimulation on cerebral blood mean flow velocity (MFV) in men and women. The study included 16 (8 men and 8 women) right-handed healthy subjects. The MFV was recorded simultaneously in both right and left middle cerebral arteries in Dark and white Light conditions, and during color (Blue, Yellow and Red) stimulations, and was analyzed using functional transcranial Doppler spectroscopy (fTCDS) technique. Color processing occurred within cortico-subcortical circuits. In men, wavelength-differencing of Yellow/Blue pairs occurred within the right hemisphere by processes of cortical long-term depression (CLTD) and subcortical long-term potentiation (SLTP). Conversely, in women, frequency-differencing of Blue/Yellow pairs occurred within the left hemisphere by processes of cortical long-term potentiation (CLTP) and subcortical long-term depression (SLTD). In both genders, there was luminance effect in the left hemisphere, while in men it was along an axis opposite (orthogonal) to that of chromatic effect, in women, it was parallel. Gender-related differences in color processing demonstrated a right hemisphere cognitive style for wavelength-differencing in men, and a left hemisphere cognitive style for frequency-differencing in women. There are potential applications of fTCDS technique, for stroke rehabilitation and monitoring of drug effects.

  11. Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients With Conductive and Sensorineural Hearing Loss and a Group With Vestibular Schawannoma

    Directory of Open Access Journals (Sweden)

    Parvane Mahdi

    2013-06-01

    Full Text Available Introduction: Vestibular evoked myogenic potential (VEMP has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients.   Materials and Methods: We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants.   Results: In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05. However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025. In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87% of the 32 ears using the AC method, whereas all (100% displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS, 2 (50.00% had neither AC-VEMP nor BC-VEMP. Conclusion:  Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

  12. Do code of conduct audits improve chemical safety in garment factories? Lessons on corporate social responsibility in the supply chain from Fair Wear Foundation.

    Science.gov (United States)

    Lindholm, Henrik; Egels-Zandén, Niklas; Rudén, Christina

    2016-10-01

    In managing chemical risks to the environment and human health in supply chains, voluntary corporate social responsibility (CSR) measures, such as auditing code of conduct compliance, play an important role. To examine how well suppliers' chemical health and safety performance complies with buyers' CSR policies and whether audited factories improve their performance. CSR audits (n = 288) of garment factories conducted by Fair Wear Foundation (FWF), an independent non-profit organization, were analyzed using descriptive statistics and statistical modeling. Forty-three per cent of factories did not comply with the FWF code of conduct, i.e. received remarks on chemical safety. Only among factories audited 10 or more times was there a significant increase in the number of factories receiving no remarks. Compliance with chemical safety requirements in garment supply chains is low and auditing is statistically correlated with improvements only at factories that have undergone numerous audits.

  13. Enhanced high temperature thermoelectric response of sulphuric acid treated conducting polymer thin films

    KAUST Repository

    Sarath Kumar, S. R.; Kurra, Narendra; Alshareef, Husam N.

    2015-01-01

    We report the high temperature thermoelectric properties of solution processed pristine and sulphuric acid treated poly(3, 4-ethylenedioxythiophene):poly(4-styrenesulfonate) (or PEDOT:PSS) films. The acid treatment is shown to simultaneously enhance the electrical conductivity and Seebeck coefficient of the metal-like films, resulting in a five-fold increase in thermoelectric power factor (0.052 W/m. K ) at 460 K, compared to the pristine film. By using atomic force micrographs, Raman and impedance spectra and using a series heterogeneous model for electrical conductivity, we demonstrate that acid treatment results in the removal of PSS from the films, leading to the quenching of accumulated charge-induced energy barriers that prevent hopping conduction. The continuous removal of PSS with duration of acid treatment also alters the local band structure of PEDOT:PSS, resulting in simultaneous enhancement in Seebeck coefficient.

  14. Enhanced high temperature thermoelectric response of sulphuric acid treated conducting polymer thin films

    KAUST Repository

    Sarath Kumar, S. R.

    2015-11-24

    We report the high temperature thermoelectric properties of solution processed pristine and sulphuric acid treated poly(3, 4-ethylenedioxythiophene):poly(4-styrenesulfonate) (or PEDOT:PSS) films. The acid treatment is shown to simultaneously enhance the electrical conductivity and Seebeck coefficient of the metal-like films, resulting in a five-fold increase in thermoelectric power factor (0.052 W/m. K ) at 460 K, compared to the pristine film. By using atomic force micrographs, Raman and impedance spectra and using a series heterogeneous model for electrical conductivity, we demonstrate that acid treatment results in the removal of PSS from the films, leading to the quenching of accumulated charge-induced energy barriers that prevent hopping conduction. The continuous removal of PSS with duration of acid treatment also alters the local band structure of PEDOT:PSS, resulting in simultaneous enhancement in Seebeck coefficient.

  15. Validity of microgravity simulation models on earth

    DEFF Research Database (Denmark)

    Regnard, J; Heer, M; Drummer, C

    2001-01-01

    Many studies have used water immersion and head-down bed rest as experimental models to simulate responses to microgravity. However, some data collected during space missions are at variance or in contrast with observations collected from experimental models. These discrepancies could reflect...... incomplete knowledge of the characteristics inherent to each model. During water immersion, the hydrostatic pressure lowers the peripheral vascular capacity and causes increased thoracic blood volume and high vascular perfusion. In turn, these changes lead to high urinary flow, low vasomotor tone, and a high...

  16. A simple route to synthesize conductive stimuli-responsive polypyrrole nanocomposite hydrogel particles with strong magnetic properties and their performance for removal of hexavalent chromium ions from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Hasan, E-mail: samarhass@yahoo.com [Department of Chemistry, Rajshahi University, Rajshahi 6205 (Bangladesh); Rahman, Mohammad Mostafizar; Ali, Mohammad Azgar [Department of Chemistry, Rajshahi University, Rajshahi 6205 (Bangladesh); Minami, Hideto [Graduate School of Engineering, Kobe University, Kobe 657-8501 (Japan); Tauer, Klaus [Max Planck Institute of Colloid and Interfaces, Am Mühlenberg, 14476 Golm (Germany); Gafur, Mohammad Abdul [Pilot Plant and Process Development Centre, BCSIR, Dhaka 1205 (Bangladesh); Rahman, Mohammad Mahbubor [Department of Chemistry, Rajshahi University, Rajshahi 6205 (Bangladesh)

    2016-08-15

    A combination of maghemite polypyrrole (PPy/γ-Fe{sub 2}O{sub 3}) and stimuli-responsive properties in the same hydrogel microspheres is expected to enhance their application potential in various fields such as tissue engineering, regenerative medicine, biosensors, biomedical applications and removal of heavy metals from waste water, catalysis etc. In this investigation a simple two step process is used to prepare conductive stimuli-responsive polypyrrole (PPy) composite hydrogel particles with strong magnetic properties. Poly(styrene-methacrylic acid-N-isopropylacrylamide-polyethelene glycol methacrylate) or P(S-NIPAM-MAA-PEGMA) hydrogel seed particles are first prepared by soap-free precipitation copolymerization. The copolymer hydrogel particles exhibited both temperature- and pH-responsive volume phase transition. Conductive P(S-NIPAM-MAA-PEGMA)/PPy/γ-Fe{sub 2}O{sub 3} nanocomposite hydrogel particles are then prepared by seeded chemical oxidative polymerization of pyrrole in the presence of P(S-NIPAM-MAA-PEGMA) hydrogel seed particles using FeCl{sub 3} as a oxidant and p-toluene sulfonic acid ( p-TSA) as a dopant. In the reaction system FeCl{sub 3} functioned as a source of Fe(III) for the formation of γ-Fe{sub 2}O{sub 3}. This reaction also requires the initial presence of Fe(II) provided by the addition of FeCl{sub 2}. The size and size distribution, surface structure, and morphology of the prepared conductive composite hydrogel particles are confirmed by FTIR, electron micrographs, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV–visible spectroscopy. The performance of nanocomposite hydrogel particles has been evaluated for the removal of hexavalent chromium (Cr) ions from water. - Highlights: • P(S-NIPAM-MAA-PEGMA) hydrogel particles were prepared. • P(S-NIPAM-MAA-PEGMA)/PPy/γ-Fe{sub 2}O{sub 3} nanocomposite hydrogel particles were prepared. • Oxidative polymerization of pyrrole and precipitation of γ-Fe{sub 2}O{sub 3

  17. Ethical Issues in the Conduct of Supervision.

    Science.gov (United States)

    Sherry, Patrick

    1991-01-01

    Uses American Psychological Association code of ethics to understand ethical issues present in the conduct of supervision. Discusses ethical issues of responsibility, client and supervisee welfare, confidentiality, competency, moral and legal standards, public statements, and professional relationships in relation to supervision. (Author/NB)

  18. Using Electronic Mail to Conduct Survey Research.

    Science.gov (United States)

    Thach, Liz

    1995-01-01

    Describes public and private online networks and the characteristics of electronic mail. Reviews the literature on survey research conducted via electronic mail, and examines the issues of design, implementation, and response. A table displays advantages and disadvantages of electronic mail surveys. (AEF)

  19. Response Surface Methodology Approach on Effect of Cutting Parameter on Tool Wear during End Milling of High Thermal Conductivity Steel -150 (HTCS-150)

    International Nuclear Information System (INIS)

    Mohd Hadzley, A B; Wan Mohd Azahar, W M Y; Izamshah, R; Mohd Shahir, K; Mohd Amran, A; Anis Afuza, A

    2016-01-01

    This paper presents a study of development the tool life's mathematical model during the milling process on High Thermal Conductivity Steel 150 (HTCS-150) 56 HRC. Using response surface methodology, the mathematical models for tool life have been developed in terms of cutting speed, feed rate and depth of cut. Box-Behnken techniques is a part of Response Surface Methodology (RSM) has been used to carry out the work plan to predict, the tool wear and generate the numerical equation in relation to independent variable parameters by Design Expert software. Dry milling experiments were conducted by using two levels of cutting speed, feed rate and depth of cut. In this study, the variable for the cutting speed, feed rate and depth of cut were in the range of 484-553 m/min, 0.31-0.36 mm/tooth, and 0.1-0.5 mm, width of cut is constantly 0.01mm per passes. The tool wear was measured using tool maker microscope. The effect of input factors that on the responds were identified by using mean of ANOVA. The responds of tool wear then simultaneously optimized. The validation of the test reveals the model accuracy 5% and low tool wear under same experimental condition. (paper)

  20. Response Surface Methodology Approach on Effect of Cutting Parameter on Tool Wear during End Milling of High Thermal Conductivity Steel -150 (HTCS-150)

    Science.gov (United States)

    Mohd Hadzley, A. B.; Mohd Azahar, W. M. Y. Wan; Izamshah, R.; Mohd Shahir, K.; Mohd Amran, A.; Anis Afuza, A.

    2016-02-01

    This paper presents a study of development the tool life's mathematical model during the milling process on High Thermal Conductivity Steel 150 (HTCS-150) 56 HRC. Using response surface methodology, the mathematical models for tool life have been developed in terms of cutting speed, feed rate and depth of cut. Box-Behnken techniques is a part of Response Surface Methodology (RSM) has been used to carry out the work plan to predict, the tool wear and generate the numerical equation in relation to independent variable parameters by Design Expert software. Dry milling experiments were conducted by using two levels of cutting speed, feed rate and depth of cut. In this study, the variable for the cutting speed, feed rate and depth of cut were in the range of 484-553 m/min, 0.31-0.36 mm/tooth, and 0.1-0.5 mm, width of cut is constantly 0.01mm per passes. The tool wear was measured using tool maker microscope. The effect of input factors that on the responds were identified by using mean of ANOVA. The responds of tool wear then simultaneously optimized. The validation of the test reveals the model accuracy 5% and low tool wear under same experimental condition.

  1. Dielectric and electrical conductivity studies of bulk lead (II) oxide (PbO)

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, A.A.A., E-mail: aaadarwish@gmail.com [Department of Physics, Faculty of Education at Al-Mahweet, Sana’a University, Al-Mahwit (Yemen); Department of Physics, Faculty of Science, University of Tabuk, P.O. Box 741, Tabuk 71491, Tabuk (Saudi Arabia); El-Zaidia, E.F.M.; El-Nahass, M.M. [Department of Physics, Faculty of Education, Ain Shams University, Rorxy, Cairo 11757 (Egypt); Hanafy, T.A. [Department of Physics, Faculty of Science, University of Tabuk, P.O. Box 741, Tabuk 71491, Tabuk (Saudi Arabia); Department of Physics, Faculty of Science, Fayoum University, 63514 El Fayoum (Egypt); Al-Zubaidi, A.A. [Department of Physics, Faculty of Science, University of Tabuk, P.O. Box 741, Tabuk 71491, Tabuk (Saudi Arabia)

    2014-03-15

    Highlights: • The AC measurements of PbO were measured at temperature range 313–523 K. • The dielectric constants increased with temperature. • The mechanism responsible for AC conduction is electronic hopping. -- Abstract: The dielectric properties, the impedance spectroscopy and AC conductivity of bulk PbO have been investigated as a function of frequency and temperature. The measurements were carried out in the frequency range from 40 to 5 × 10{sup 6} Hz and in temperature range from 313 to 523 K. The frequency response of dielectric constant, ε{sub 1}, and dielectric loss index, ε{sub 2}, as a function of temperature were studied. The values of ε{sub 1} and ε{sub 2} were found to decrease with the increase in frequency. However, they increase with the increase in temperature. The presence of a single arc in the complex modulus spectrum at different temperatures confirms the single-phase character of the PbO. The AC conductivity exhibited a universal dynamic response: σ{sub AC} = Aω{sup s}. The AC conductivity was also found to increase with increasing temperature and frequency. The correlation barrier hopping (CBH) model was found to apply to the AC conductivity data. The calculated values of s were decreased with temperature. This behavior reveals that the conduction mechanism for PbO samples is CBH. The activation energy for AC conductivity decreases with increasing frequency. This confirms that the hopping conduction to the dominant mechanism for PbO samples.

  2. Nonstoichiometry and conductivity anisotropy of lead germanate single crystals

    International Nuclear Information System (INIS)

    Jermakov, O.S.; Duda, V.M.

    2010-01-01

    The conductivity of lead germanate single crystals with the stoichiometric composition, PbO deficiency, and PbO excess has been measured. A reduction of the PbO fraction in the initial blend leads to a considerable increase of the conductivity, because the fraction of lead ions which change their valency from Pb 2+ to Pb 3+ grows. The relative arrangement of lead ions, which are able to change their valency and trap holes, can be responsible for a significant anisotropy of conductivity.

  3. Results of gap conductance tests in the power burst facility

    International Nuclear Information System (INIS)

    Garner, R.W.; Sparks, D.T.

    1977-01-01

    Light water reactor (LWR) fuel rod behavior studies are being conducted by the Thermal Fuels Behavior Program of EG and G Idaho, Inc. These studies are being performed under contract to the Energy Research and Development Adminstration at the Idaho National Engineering Laboratory (INEL), as part of the Nuclear Regulatory Commission's Water Reactor Safety Research Fuel Behavior Program. Experimental data for verification of analytical models developed to predict light water nuclear fuel rod behavior under normal and postulated accident conditions are being obtained from a variety of in-reactor and out-of-reactor experiments. This paper summarizes the results of tests performed in the Power Burst Facility (PBF) to obtain data from which the thermal response, gap conductance, and stored energy of LWR fuel rods can be determined. Primary objectives of the PBF gap conductance test program are (a) to obtain data on a variety of pressurized water reactor (PWR) and boiling water reactor (BWR) fuel rod designs, under a wide range of operating conditions, from which gap conductance values can be determined and (b) to evaluate experimentally the power oscillation method for measuring the gap conductance and thermal response of a fresh or burned LWR fuel rod. Tests have been performed with both irradiated and unirradiated PWR-type fuel and with fresh BWR-type fuel rods. Some PWR rod test results are described, and the thermal response data from BWR rod tests are discussed in greater detail. Comparisons are made of gap conductance values determined by the tests with analytically calculated values using the Fuel Rod Analysis Program-Transient (FRAP-T) computer code. These comparisons provide insight into both the experimental measurements methods and the validity of the gap conductance models

  4. Photo control of transport properties in a disordered wire: Average conductance, conductance statistics, and time-reversal symmetry

    International Nuclear Information System (INIS)

    Kitagawa, Takuya; Oka, Takashi; Demler, Eugene

    2012-01-01

    In this paper, we study the full conductance statistics of a disordered 1D wire under the application of light. We develop the transfer matrix method for periodically driven systems to analyze the conductance of a large system with small frequency of light, where coherent photon absorptions play an important role to determine not only the average but also the shape of conductance distributions. The average conductance under the application of light results from the competition between dynamic localization and effective dimension increase, and shows non-monotonic behavior as a function of driving amplitude. On the other hand, the shape of conductance distribution displays a crossover phenomena in the intermediate disorder strength; the application of light dramatically changes the distribution from log-normal to normal distributions. Furthermore, we propose that conductance of disordered systems can be controlled by engineering the shape, frequency and amplitude of light. Change of the shape of driving field controls the time-reversals symmetry and the disordered system shows analogous behavior as negative magneto-resistance known in static weak localization. A small change of frequency and amplitude of light leads to a large change of conductance, displaying giant opto-response. Our work advances the perspective to control the mean as well as the full conductance statistics by coherently driving disordered systems. - Highlights: ► We study conductance of disordered systems under the application of light. ► Full conductance distributions are obtained. ► A transfer matrix method is developed for driven systems. ► Conductances are dramatically modified upon the application of light. ► Time-reversal symmetry can also be controlled by light application.

  5. Effective electrical and thermal conductivity of multifilament twisted superconductors

    International Nuclear Information System (INIS)

    Chechetkin, V.R.

    2013-01-01

    The effective electrical and thermal conductivity of composite wire with twisted superconducting filaments embedded into normal metal matrix is calculated using the extension of Bruggeman method. The resistive conductivity of superconducting filaments is described in terms of symmetric tensor, whereas the conductivity of a matrix is assumed to be isotropic and homogeneous. The dependence of the resistive electrical conductivity of superconducting filaments on temperature, magnetic field, and current density is implied to be parametric. The resulting effective conductivity tensor proved to be non-diagonal and symmetric. The non-diagonal transverse–longitudinal components of effective electrical conductivity tensor are responsible for the redistribution of current between filaments. In the limits of high and low electrical conductivity of filaments the transverse effective conductivity tends to that of obtained previously by Carr. The effective thermal conductivity of composite wires is non-diagonal and radius-dependent even for the isotropic and homogeneous thermal conductivities of matrix and filaments.

  6. Do code of conduct audits improve chemical safety in garment factories? Lessons on corporate social responsibility in the supply chain from Fair Wear Foundation

    Science.gov (United States)

    2016-01-01

    Background In managing chemical risks to the environment and human health in supply chains, voluntary corporate social responsibility (CSR) measures, such as auditing code of conduct compliance, play an important role. Objectives To examine how well suppliers’ chemical health and safety performance complies with buyers’ CSR policies and whether audited factories improve their performance. Methods CSR audits (n = 288) of garment factories conducted by Fair Wear Foundation (FWF), an independent non-profit organization, were analyzed using descriptive statistics and statistical modeling. Results Forty-three per cent of factories did not comply with the FWF code of conduct, i.e. received remarks on chemical safety. Only among factories audited 10 or more times was there a significant increase in the number of factories receiving no remarks. Conclusions Compliance with chemical safety requirements in garment supply chains is low and auditing is statistically correlated with improvements only at factories that have undergone numerous audits. PMID:27611103

  7. Sex Differences in Autonomic Correlates of Conduct Problems and Aggression

    Science.gov (United States)

    Beauchaine, Theodore P.; Hong, James; Marsh, Penny

    2008-01-01

    The study aims to evaluate group differences in autonomic nervous system (ANS) responding between males and females with conduct problems and determine whether aggression accounts for variance in ANS responding over the effects of conduct problems. The results indicated marked differences in psycho-physiological responses between males and females.

  8. Method for conducting nonlinear electrochemical impedance spectroscopy

    Science.gov (United States)

    Adler, Stuart B.; Wilson, Jamie R.; Huff, Shawn L.; Schwartz, Daniel T.

    2015-06-02

    A method for conducting nonlinear electrochemical impedance spectroscopy. The method includes quantifying the nonlinear response of an electrochemical system by measuring higher-order current or voltage harmonics generated by moderate-amplitude sinusoidal current or voltage perturbations. The method involves acquisition of the response signal followed by time apodization and fast Fourier transformation of the data into the frequency domain, where the magnitude and phase of each harmonic signal can be readily quantified. The method can be implemented on a computer as a software program.

  9. Conductance calculations with a wavelet basis set

    DEFF Research Database (Denmark)

    Thygesen, Kristian Sommer; Bollinger, Mikkel; Jacobsen, Karsten Wedel

    2003-01-01

    We present a method based on density functional theory (DFT) for calculating the conductance of a phase-coherent system. The metallic contacts and the central region where the electron scattering occurs, are treated on the same footing taking their full atomic and electronic structure into account....... The linear-response conductance is calculated from the Green's function which is represented in terms of a system-independent basis set containing wavelets with compact support. This allows us to rigorously separate the central region from the contacts and to test for convergence in a systematic way...

  10. Dry Needling Related Short-Term Vasodilation in Chronic Sciatica under Infrared Thermovision

    Directory of Open Access Journals (Sweden)

    Elżbieta Skorupska

    2015-01-01

    Full Text Available Vasomotor responses to dry needling (DN of trigger points (TrPs under infrared thermovision (IRT camera control and TrPs coexistence in chronic sciatica patients have never been studied. Materials and Methods. Fifty consecutive chronic sciatica patients were enrolled in the study. DN under IRT control was performed for all patients regardless of gluteus minimus (GM active TrPs examination. Then, the vasomotor response and its agreement with TrPs examination were evaluated. Results. The prevalence of GM active TrPs was 32%. DN provokes intensive vasodilatation for TrPs-positive patients only, with the localization dependent on referred pain during the procedure (r=0.896;  P=0.000 not the daily complaint. The increase of vasodilatation was, for example, for thigh, TrPs-positive +30.29% (P<0.05 versus TrPs-negative +4.08%. Additionally, a significant skin temperature increase was observed for TrPs-positive only, for example, thigh +1.5 ± 1.3°C (maximum and +1.2 ± 1.0°C (average (both P<0.05. Conclusion. GM active TrPs prevalence among chronic sciatica patients was around one in three. Every TrPs-positive subject presented with vasodilatation under IRT in the area of DN related referred pain. Although TrPs involvement in chronic sciatica patients is possible, further studies on a bigger group of patients are still required.

  11. Methodological issues involved in conducting qualitative research ...

    African Journals Online (AJOL)

    The purpose of this article is to describe the methodological issues involved in conducting qualitative research to explore and describe nurses' experience of being directly involved with termination of pregnancies and developing guidelines for support for these nurses. The article points out the sensitivity and responsibility ...

  12. 45 CFR 150.313 - Market conduct examinations.

    Science.gov (United States)

    2010-10-01

    ..., or the operation of a non-Federal governmental plan, involving the review of one or more (or a combination) of a responsible entity's business or operational affairs, or both, to verify compliance with... Non-Federal Governmental Plans-Civil Money Penalties § 150.313 Market conduct examinations. (a...

  13. Electro-Conductive Membranes for Permeation Enhancement and Fouling Mitigation: A Short Review

    Directory of Open Access Journals (Sweden)

    Patrizia Formoso

    2017-07-01

    Full Text Available The research on electro-conductive membranes has expanded in recent years. These membranes have strong prospective as key components in next generation water treatment plants because they are engineered in order to enhance their performance in terms of separation, flux, fouling potential, and permselectivity. The present review summarizes recent developments in the preparation of electro-conductive membranes and the mechanisms of their response to external electric voltages in order to obtain an improvement in permeation and mitigation in the fouling growth. In particular, this paper deals with the properties of electro-conductive polymers and the preparation of electro-conductive polymer membranes with a focus on responsive membranes based on polyaniline, polypyrrole and carbon nanotubes. Then, some examples of electro-conductive membranes for permeation enhancement and fouling mitigation by electrostatic repulsion, hydrogen peroxide generation and electrochemical oxidation will be presented.

  14. Electro-Conductive Membranes for Permeation Enhancement and Fouling Mitigation: A Short Review.

    Science.gov (United States)

    Formoso, Patrizia; Pantuso, Elvira; De Filpo, Giovanni; Nicoletta, Fiore Pasquale

    2017-07-28

    The research on electro-conductive membranes has expanded in recent years. These membranes have strong prospective as key components in next generation water treatment plants because they are engineered in order to enhance their performance in terms of separation, flux, fouling potential, and permselectivity. The present review summarizes recent developments in the preparation of electro-conductive membranes and the mechanisms of their response to external electric voltages in order to obtain an improvement in permeation and mitigation in the fouling growth. In particular, this paper deals with the properties of electro-conductive polymers and the preparation of electro-conductive polymer membranes with a focus on responsive membranes based on polyaniline, polypyrrole and carbon nanotubes. Then, some examples of electro-conductive membranes for permeation enhancement and fouling mitigation by electrostatic repulsion, hydrogen peroxide generation and electrochemical oxidation will be presented.

  15. Endogenous salivary α-amylase does not interact with skin conductance response during fear extinction in posttraumatic stress disorder.

    Science.gov (United States)

    Zuj, Daniel V; Palmer, Matthew A; Malhi, Gin S; Bryant, Richard A; Felmingham, Kim L

    2018-04-01

    Posttraumatic Stress Disorder (PTSD) is associated with elevated noradrenergic signaling, which has an impact on emotional learning and memory. Fear extinction is thought to underlie the processes of exposure therapy, however the relationship between noradrenaline and extinction in PTSD is unclear. Participants with PTSD (n = 21), trauma-exposure without PTSD (TC; n = 36), and non-trauma-exposed controls (NTC; n = 27) completed a fear conditioning and extinction paradigm, and conditioned fear was indexed by skin conductance response (SCR). Salivary α-amylase (sAA) collected at baseline and immediately post-fear acquisition was used as an index of noradrenaline, and we examined whether sAA in response to fear acquisition was a moderator between fear extinction and PTSD symptoms. While there was a significant increase in sAA from baseline to post-fear acquisition, this was not modulated by group. Compared to TC and NTC, the PTSD group displayed a slower decline in SCRs during early extinction, which generalized across stimulus type, and was not moderated by sAA. These findings suggest that the relationship between fear extinction and PTSD symptoms does not change as a function of sAA levels; however previous research suggests other processes of fear learning may be associated with noradrenergic activity in PTSD. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  16. Effects of oral versus transdermal menopausal hormone treatments on self-reported sleep domains and their association with vasomotor symptoms in recently menopausal women enrolled in the Kronos Early Estrogen Prevention Study (KEEPS)

    Science.gov (United States)

    Cintron, Dahima; Lahr, Brian D.; Bailey, Kent R.; Santoro, Nanette; Lloyd, Robin; Manson, JoAnn E.; Neal-Perry, Genevieve; Pal, Lubna; Taylor, Hugh S.; Wharton, Whitney; Naftolin, Fredrick; Harman, S. Mitchell; Miller, Virginia M.

    2018-01-01

    Abstract Objective: This study determined whether two different formulations of hormone therapy (HT): oral conjugated equine estrogens (o-CEE; 0.45 mg/d, n = 209), transdermal 17β-estradiol (t-E2; 50 μg/d, n = 201) plus cyclic progesterone (Prometrium, 200 mg) or placebo (PBO, n = 243) affected sleep domains in participants of the Kronos Early Estrogen Prevention Study. Methods: Participants completed the Pittsburgh Sleep Quality Index at baseline and during the intervention at 6, 18, 36, and 48 months. Global sleep quality and individual sleep domain scores were compared between treatments using analysis of covariance, and correlated with vasomotor symptom (VMS) scores using Spearman correlation coefficients. Results: Global Pittsburgh Sleep Quality Index scores (mean 6.3; 24% with score >8) were similar across groups at baseline and were reduced (improved sleep quality) by both HT (average change −1.27 [o-CEE] and −1.32 [t-E2]) when compared with PBO (−0.60; P = 0.001 [o-CEE vs PBO] and P = 0.002 [t-E2 vs PBO]). Domain scores for sleep satisfaction and latency improved with both HT. The domain score for sleep disturbances improved more with t-E2 than o-CEE or PBO. Global sleep scores significantly correlated with VMS severity (rs = 0.170, P < 0.001 for hot flashes; rs = 0.177, P < 0.001 for night sweats). Change in scores for all domains except sleep latency and sleep efficiency correlated with change in severity of VMS. Conclusions: Poor sleep quality is common in recently menopausal women. Sleep quality improved with both HT formulations. The relationship of VMS with domains of sleep suggests that assessing severity of symptoms and domains of sleep may help direct therapy to improve sleep for postmenopausal women. PMID:28832429

  17. 38 CFR 0.735-10 - Cross-reference to employee ethical and other conduct standards and financial disclosure...

    Science.gov (United States)

    2010-07-01

    ... employee ethical and other conduct standards and financial disclosure regulations. 0.735-10 Section 0.735-10 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS STANDARDS OF ETHICAL CONDUCT AND RELATED RESPONSIBILITIES Standards of Ethical Conduct and Related Responsibilities of...

  18. Exploring the comparative responsiveness of a core set of outcome measures in a school-based conductive education programme.

    Science.gov (United States)

    Wright, F V; Boschen, K; Jutai, J

    2005-05-01

    Conductive education (CE) is a holistic educational system that uses an active cognitive approach to teach individuals with motor disorders to become more functional participants in daily activities. While CE's popularity continues to grow in North America and Europe, its effectiveness has not been established. The lack of definition of responsive outcome measures for evaluation of CE programmes has limited the interpretability of conclusions from earlier studies evaluating effectiveness. To determine which measures from a core set were most responsive to physical, functional and psychosocial changes associated with a school-based CE programme. This was a one-group before and after data collection design using an 8-month follow-up period. We enrolled a referral sample of nine children with cerebral palsy in Kindergarten or Grade 1 (Gross Motor Function Classification System levels 3, 4 or 5). The study took place within a school-based CE programme at a Canadian children's rehabilitation centre. Children participated in a CE full-day class for an entire school year. Physical, functional, psychosocial and participation measures included: Gross Motor Function Measure (GMFM), Quality of Upper Extremity Skills Test (QUEST), Peabody Developmental Motor Scales, Paediatric Evaluation of Disability Inventory (PEDI), Pictorial Scale of Perceived Competence and Social Acceptance for Young Children, Individualized Educational Plan, and Goal Attainment Scaling (GAS). Four children from the study's second year were also evaluated on the Impact on Family Scale (IFS), GAS and School Function Assessment. The Gross Motor Function Measure, QUEST, PEDI (Caregiver Assistance) and IFS were most responsive to change. GAS was useful in documenting and quantifying goals. Problems were encountered in evaluating self-esteem and school participation. Several strong measures of outcome were identified. Further work is needed to find valid and sensitive psychosocial and school participation

  19. Infrared Thermography in Serotonin-Induced Itch Model in Rats

    DEFF Research Database (Denmark)

    Jasemian, Yousef; Gazerani, Parisa; Dagnæs-Hansen, Frederik

    2012-01-01

    The study validated the application of infrared thermography in a serotonin-induced itch model in rats since the only available method in animal models of itch is the count of scratching bouts. Twenty four adult Sprague-Dawley male rats were used in 3 experiments: 1) local vasomotor response...... with no scratching reflex was investigated. Serotonin elicited significant scratching and lowered the local temperature at the site of injection. A negative dose-temperature relationship of serotonin was found by thermography. Vasoregulation at the site of serotonin injection took place in the absence of scratching...

  20. 38 CFR 0.735-11 - Other conduct on the job.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Other conduct on the job. 0.735-11 Section 0.735-11 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Responsibilities of Employees § 0.735-11 Other conduct on the job. Relationship with beneficiaries and claimants...

  1. Determination of head conductivity frequency response in vivo with optimized EIT-EEG

    NARCIS (Netherlands)

    Dabek, Juhani; Kalogianni, Konstantina; Rotgans, Edwin; van der Helm, Frans C.T.; Kwakkel, Gert; van Wegen, Erwin E.H.; Daffertshofer, Andreas; de Munck, Jan C.

    2016-01-01

    Electroencephalography (EEG) benefits from accurate head models. Dipole source modelling errors can be reduced from over 1 cm to a few millimetres by replacing generic head geometry and conductivity with tailored ones. When adequate head geometry is available, electrical impedance tomography (EIT)

  2. The physiological role of AT1 receptors in the ventrolateral medulla

    Directory of Open Access Journals (Sweden)

    T. Tagawa

    2000-06-01

    Full Text Available Neurons in the rostral and caudal parts of the ventrolateral medulla (VLM play a pivotal role in the regulation of sympathetic vasomotor activity and blood pressure. Studies in several species, including humans, have shown that these regions contain a high density of AT1 receptors specifically associated with neurons that regulate the sympathetic vasomotor outflow, or the secretion of vasopressin from the hypothalamus. It is well established that specific activation of AT1 receptors by application of exogenous angiotensin II in the rostral and caudal VLM excites sympathoexcitatory and sympathoinhibitory neurons, respectively, but the physiological role of these receptors in the normal synaptic regulation of VLM neurons is not known. In this paper we review studies which have defined the effects of specific activation or blockade of these receptors on cardiovascular function, and discuss what these findings tell us with regard to the physiological role of AT1 receptors in the VLM in the tonic and phasic regulation of sympathetic vasomotor activity and blood pressure.

  3. Measurement of leaf hydraulic conductance and stomatal conductance and their responses to irradiance and dehydration using the Evaporative Flux Method (EFM).

    Science.gov (United States)

    Sack, Lawren; Scoffoni, Christine

    2012-12-31

    Water is a key resource, and the plant water transport system sets limits on maximum growth and drought tolerance. When plants open their stomata to achieve a high stomatal conductance (gs) to capture CO2 for photosynthesis, water is lost by transpiration(1,2). Water evaporating from the airspaces is replaced from cell walls, in turn drawing water from the xylem of leaf veins, in turn drawing from xylem in the stems and roots. As water is pulled through the system, it experiences hydraulic resistance, creating tension throughout the system and a low leaf water potential (Ψ(leaf)). The leaf itself is a critical bottleneck in the whole plant system, accounting for on average 30% of the plant hydraulic resistance(3). Leaf hydraulic conductance (K(leaf) = 1/ leaf hydraulic resistance) is the ratio of the water flow rate to the water potential gradient across the leaf, and summarizes the behavior of a complex system: water moves through the petiole and through several orders of veins, exits into the bundle sheath and passes through or around mesophyll cells before evaporating into the airspace and being transpired from the stomata. K(leaf) is of strong interest as an important physiological trait to compare species, quantifying the effectiveness of the leaf structure and physiology for water transport, and a key variable to investigate for its relationship to variation in structure (e.g., in leaf venation architecture) and its impacts on photosynthetic gas exchange. Further, K(leaf) responds strongly to the internal and external leaf environment(3). K(leaf) can increase dramatically with irradiance apparently due to changes in the expression and activation of aquaporins, the proteins involved in water transport through membranes(4), and K(leaf) declines strongly during drought, due to cavitation and/or collapse of xylem conduits, and/or loss of permeability in the extra-xylem tissues due to mesophyll and bundle sheath cell shrinkage or aquaporin deactivation(5

  4. A Comparison of Oral Sensory Effects of Three TRPA1 Agonists in Young Adult Smokers and Non-smokers

    Science.gov (United States)

    Hansen, Eva Ø.; Arendt-Nielsen, Lars; Boudreau, Shellie A.

    2017-01-01

    This study profiled intra-oral somatosensory and vasomotor responses to three different transient receptor potential (TRP) channels, subfamily A, member 1 (TRPA1) agonists (menthol, nicotine, and cinnamaldehyde) in smoking and non-smoking young adults. Healthy non-smokers (N = 30) and otherwise healthy smokers (N = 25) participated in a randomized, double-blinded, cross-over study consisting of three experimental sessions in which they received menthol (30 mg), nicotine (4 mg), or cinnamaldehyde (25 mg) chewing gum. Throughout a standardized 10 min chewing regime, burning, cooling, and irritation intensities, and location were recorded. In addition, blood pressure, heart rate and intra-oral temperature were assessed before, during, and after chewing. Basal intra-oral temperature was lower in smokers (35.2°C ± 1.58) as compared to non-smokers (35.9°C ± 1.61) [F(1, 52) = 8.5, P = 0.005, post hoc, p = 0.005]. However, the increase in temperature, heart rate, and blood pressure in response to chewing menthol, nicotine, and cinnamaldehyde gums were similar between smokers and non-smokers. Although smoking status did not influence the intensity of burning, cooling, and irritation, smokers did report nicotine burn more often (92%) than non-smokers (63%) [χ(1, N=55)2 = 6.208, P = 0.013]. Reports of nicotine burn consistently occurred at the back of the throat and cinnamaldehyde burn on the tongue. The cooling sensation of menthol was more widely distributed in the mouth of non-smokers as compared to smokers. Smoking alters thermoregulation, somatosensory, and possibly TRPA1 receptor responsiveness and suggests that accumulated exposure of nicotine by way of cigarette smoke alters oral sensory and vasomotor sensitivity. PMID:28936178

  5. 36 CFR 811.1 - Cross-references to employees' ethical conduct standards, financial disclosure and financial...

    Science.gov (United States)

    2010-07-01

    ...' ethical conduct standards, financial disclosure and financial interests regulations and other conduct... EMPLOYEE RESPONSIBILITIES AND CONDUCT § 811.1 Cross-references to employees' ethical conduct standards... Council on Historic Preservation are subject to the executive branch-wide standards of ethical conduct...

  6. NON-INVASIVE EVALUATION OF NERVE CONDUCTION IN SMALL DIAMETER FIBERS IN THE RAT.

    Science.gov (United States)

    Zotova, Elena G; Arezzo, Joseph C

    2013-01-01

    A novel non-invasive technique was applied to measure velocity within slow conducting axons in the distal extreme of the sciatic nerve (i.e., digital nerve) in a rat model. The technique is based on the extraction of rectified multiple unit activity (MUA) from in vivo whole nerve compound responses. This method reliably identifies compound action potentials in thinly myelinated fibers conducting at a range of 9-18 m/s (Aδ axons), as well as in a subgroup of unmylinated C fibers conducting at approximately 1-2 m/s. The sensitivity of the method to C-fiber conduction was confirmed by the progressive decrement of the responses in the 1-2 m/s range over a 20-day period following the topical application of capsaicin (ANOVA p <0.03). Increasing the frequency of applied repetitive stimulation over a range of 0.75 Hz to 6.0 Hz produced slowing of conduction and a significant decrease in the magnitude of the compound C-fiber response (ANOVA p <0.01). This technique offers a unique opportunity for the non-invasive, repeatable, and quantitative assessment of velocity in the subsets of Aδ and C fibers in parallel with evaluation of fast nerve conduction.

  7. Can the Responses of Photosynthesis and Stomatal Conductance to Water and Nitrogen Stress Combinations Be Modeled Using a Single Set of Parameters?

    Science.gov (United States)

    Zhang, Ningyi; Li, Gang; Yu, Shanxiang; An, Dongsheng; Sun, Qian; Luo, Weihong; Yin, Xinyou

    2017-01-01

    Accurately predicting photosynthesis in response to water and nitrogen stress is the first step toward predicting crop growth, yield and many quality traits under fluctuating environmental conditions. While mechanistic models are capable of predicting photosynthesis under fluctuating environmental conditions, simplifying the parameterization procedure is important toward a wide range of model applications. In this study, the biochemical photosynthesis model of Farquhar, von Caemmerer and Berry (the FvCB model) and the stomatal conductance model of Ball, Woodrow and Berry which was revised by Leuning and Yin (the BWB-Leuning-Yin model) were parameterized for Lilium (L. auratum × speciosum “Sorbonne”) grown under different water and nitrogen conditions. Linear relationships were found between biochemical parameters of the FvCB model and leaf nitrogen content per unit leaf area (Na), and between mesophyll conductance and Na under different water and nitrogen conditions. By incorporating these Na-dependent linear relationships, the FvCB model was able to predict the net photosynthetic rate (An) in response to all water and nitrogen conditions. In contrast, stomatal conductance (gs) can be accurately predicted if parameters in the BWB-Leuning-Yin model were adjusted specifically to water conditions; otherwise gs was underestimated by 9% under well-watered conditions and was overestimated by 13% under water-deficit conditions. However, the 13% overestimation of gs under water-deficit conditions led to only 9% overestimation of An by the coupled FvCB and BWB-Leuning-Yin model whereas the 9% underestimation of gs under well-watered conditions affected little the prediction of An. Our results indicate that to accurately predict An and gs under different water and nitrogen conditions, only a few parameters in the BWB-Leuning-Yin model need to be adjusted according to water conditions whereas all other parameters are either conservative or can be adjusted according to

  8. Water cut measurement of oil–water flow in vertical well by combining total flow rate and the response of a conductance probe

    International Nuclear Information System (INIS)

    Chen, Jianjun; Xu, Lijun; Cao, Zhang; Zhang, Wen; Liu, Xingbin; Hu, Jinhai

    2015-01-01

    In this paper, a conductance probe-based well logging instrument was developed and the total flow rate is combined with the response of the conductance probe to estimate the water cut of the oil–water flow in a vertical well. The conductance probe records the time-varying electrical characteristics of the oil–water flow. Linear least squares regression (LSR) and nonlinear support vector regression (SVR) were used to establish models to map the total flow rate and features extracted from the probe response onto the water cut, respectively. Principal component analysis (PCA) and partial least squares analysis (PLSA) techniques were employed to reduce data redundancy within the extracted features. An experiment was carried out in a vertical pipe with an inner diameter of 125 mm and a height of 24 m in an experimental multi-phase flow setup, Daqing Oilfield, China. In the experiment, oil–water flow was used and the total flow rate varied from 10 to 200 m 3 per day and the water cut varied from 0% to 100%. As a direct comparison, the cases were also studied when the total flow rate was not used as an independent input to the models. The results obtained demonstrate that: (1) the addition of the total flow rate as an input to the regression models can greatly improve the accuracy of water cut prediction, (2) the nonlinear SVR model performs much better than the linear LSR model, and (3) for the SVR model with the total flow rate as an input, the adoption of PCA or PLSA not only decreases the dimensions of inputs, but also increases prediction accuracy. The SVR model with five PCA-treated features plus the total flow rate achieves the best performance in water cut prediction, with a coefficient of determination (R 2 ) as high as 0.9970. The corresponding root mean squared error (RMSE) and mean quoted error (MQE) are 0.0312% and 1.99%, respectively. (paper)

  9. Skin Conductance Response in ICU patients with various stressors: a case series

    NARCIS (Netherlands)

    Tjan, D.H.T.; Schellaars, R.; Volders, J.; Weda, J.; Johnson, M.T.; Lubberding, M.; Dijk, E.O.; Ouwerkerk, M.; Van Zanten, A.R.H.

    2012-01-01

    Measuring stress levels in the ICU is not well defined and lacks reliable and valid methods of detection. ICU patients experience different kinds of stress like pain, dyspnoea, anxiety and general discomfort. Skin conductance has recently been shown to be a promising physiological indicator of pain

  10. Electron quantum interferences and universal conductance fluctuations

    International Nuclear Information System (INIS)

    Benoit, A.; Pichard, J.L.

    1988-05-01

    Quantum interferences yield corrections to the classical ohmic behaviour predicted by Boltzmann theory in electronic transport: for instance the well-known ''weak localization'' effects. Furthermore, very recently, quantum interference effects have been proved to be responsible for statistically different phenomena, associated with Universal Conductance Fluctuations and observed on very small devices [fr

  11. TEMPERAMENT CHARACTERISTICS OF CHILDREN WITH CONDUCT AND CONVERSION DISORDERS

    OpenAIRE

    Malhotra, Savita

    1989-01-01

    SUMMARY In a comparative study of temperament profiles of groups of 30 children each diagnosed as conduct disorders, conversion disorder, emotional disorders (according to DSM-III) and normal control, it was found that the children diagnosed as conduct disorders showed high activity and intensity of emotional response as well as negative mood, those diagnosed as conversion disorder exhibited low distractibility. The significance of various temperament variables in differing clinical outcomes ...

  12. Comparison of angiography, prone renography, and exercise renography for treatment planning in hypertension

    International Nuclear Information System (INIS)

    Clorius, J.H.; Strauss, L.G.; Allenberg, J.; Hupp, T.; Schmidlin, P.; Irngartinger, G.

    1987-01-01

    Fifteen hypertensives with unilateral vascular stenosis had selective renal angiograms, prone-position gamma camera hippurate renograms, and upright exercise renograms. The exercise renograms were used to identify renal vasomotor dysfunction. Each procedure was assessed for its value to predict cure of hypertension. Therapy included one nephrectomy, and angioplasty, and 13 surgical revascularizations. Neither the extent of vascular lumen reduction as assessed with angiography nor the unilateral function impairment documented with a prone-position renogram contained useful prognostic data. Exercise renography correctly predicted the posttherapy blood pressure status in 14 of 15 hypertensives. Exercise renography can identify a newly recognized function response of the vasculature of the kidney, a pathologic response that shows promise in the investigation of hypertension

  13. Electrical conductivity imaging in the western Pacific subduction zone

    Science.gov (United States)

    Utada, Hisashi; Baba, Kiyoshi; Shimizu, Hisayoshi

    2010-05-01

    Oceanic plate subduction is an important process for the dynamics and evolution of the Earth's interior, as it is regarded as a typical downward flow of the mantle convection that transports materials from the near surface to the deep mantle. Recent seismological study showed evidence suggesting the transportation of a certain amount of water by subduction of old oceanic plate such as the Pacific plate down to 150-200 km depth into the back arc mantle. However it is not well clarified how deep into the mantle the water can be transported. The electromagnetic induction method to image electrical conductivity distribution is a possible tool to answer this question as it is known to be sensitive to the presence of water. Here we show recent result of observational study from the western Pacific subduction zone to examine the electrical conductivity distribution in the upper mantle and in the mantle transition zone (MTZ), which will provide implications how water distributes in the mantle. We take two kinds of approach for imaging the mantle conductivity, (a) semi-global and (b) regional induction approaches. Result may be summarized as follows: (a) Long (5-30 years) time series records from 8 submarine cables and 13 geomagnetic observatories in the north Pacific region were analyzed and long period magnetotelluric (MT) and geomagnetic deep sounding (GDS) responses were estimated in the period range from 1.7 to 35 days. These frequency dependent response functions were inverted to 3-dimensional conductivity distribution in the depth range between 350 and 850 km. Three major features are suggested in the MTZ depth such as, (1) a high conductivity anomaly beneath the Philippine Sea, (2) a high conductivity anomaly beneath the Hawaiian Islands, and (3) a low conductivity anomaly beneath and in the vicinity of northern Japan. (b) A three-year long deployment of ocean bottom electro-magnetometers (OBEM's) was conducted in the Philippine Sea and west Pacific Ocean from 2005

  14. Caregiver Responsiveness to the Family Bereavement Program: What predicts responsiveness? What does responsiveness predict?

    OpenAIRE

    Schoenfelder, Erin N.; Sandler, Irwin N.; Millsap, Roger E.; Wolchik, Sharlene A.; Berkel, Cady; Ayers, Timothy S.

    2013-01-01

    The study developed a multi-dimensional measure to assess participant responsiveness to a preventive intervention, and applied this measure to study how participant baseline characteristics predict responsiveness and how responsiveness predicts program outcomes. The study was conducted with caregivers who participated in the parenting-focused component of the Family Bereavement Program (FBP), a prevention program for families that have experienced parental death. The sample consisted of 89 ca...

  15. Using Simulation in Nursing PhD Education: Facilitating Application of Responsible Conduct of Research Principles.

    Science.gov (United States)

    Clayton, Margaret F; Supiano, Katherine; Wilson, Rebecca; Lassche, Madeline; Latendresse, Gwen

    Simulation is a standard clinical nursing educational approach; however, simulation is rarely used in nonclinical nursing education. In doctor of philosophy (PhD) programs, ethical content about responsible conduct of research (RCR) is traditionally didactic, presented early in the program of study. Ethics content merits review before students begin the dissertation phase; thus, the purpose of this project was to design and implement simulated scenarios to help students apply RCR principles prior to beginning independent research. Two scenarios were developed: (a) a potential protocol change discussed in a research team meeting and (b) an in-home data collection experience with an elderly participant and her daughter. Actors were trained faculty volunteers, playing roles outside their usual academic positions. Faculty facilitated scenarios by posing questions as cues related to desired learning outcomes as scenarios unfolded. Eleven nursing PhD students and 6 faculty participated. Debriefing facilitated discussion of RCR principles, common research quandaries, and suggested scenario revisions. Faculty, expert observation, and video-review showed that younger and less experienced students tried to give the "right" answer rather than implement RCR appropriate solutions. Students with more clinical experience had difficulty adopting the less familiar researcher role. Overall, simulation is a novel and useful way to enhance RCR content in PhD programs. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Using Plant Temperature to Evaluate the Response of Stomatal Conductance to Soil Moisture Deficit

    Directory of Open Access Journals (Sweden)

    Ming-Han Yu

    2015-10-01

    Full Text Available Plant temperature is an indicator of stomatal conductance, which reflects soil moisture stresses. We explored the relationship between plant temperature and soil moisture to optimize irrigation schedules in a water-stress experiment using Firmiana platanifolia (L. f. Marsili in an incubator. Canopy temperature, leaf temperature, and stomatal conductance were measured using thermal imaging and a porometer. The results indicated that (1 stomatal conductance decreased with declines in soil moisture, and reflected average canopy temperature; (2 the variation of the leaf temperature distribution was a reliable indicator of soil moisture stress, and the temperature distribution in severely water-stressed leaves exhibited greater spatial variation than that in the presence of sufficient irrigation; (3 thermal indices (Ig and crop water stress index (CWSI were theoretically proportional to stomatal conductance (gs, Ig was certified to have linearity relationship with gs and CWSI have a logarithmic relationship with gs, and both of the two indices can be used to estimate soil moisture; and (4 thermal imaging data can reflect water status irrespective of long-term water scarcity or lack of sudden rainfall. This study applied thermal imaging methods to monitor plants and develop adaptable irrigation scheduling, which are important for the formulation of effective and economical agriculture and forestry policy.

  17. Guidance manual for conducting technology demonstration activities

    International Nuclear Information System (INIS)

    Jolley, R.L.; Morris, M.I.; Singh, S.P.N.

    1991-12-01

    This demonstration guidance manual has been prepared to assist Martin Marietta Energy Systems, Inc. (Energy Systems), staff in conducting demonstrations. It is prepared in checklist style to facilitate its use and assumes that Energy Systems personnel have project management responsibility. In addition to a detailed step-by-step listing of procedural considerations, a general checklist, logic flow diagram, and several examples of necessary plans are included to assist the user in developing an understanding of the many complex activities required to manage technology demonstrations. Demonstrations are pilot-scale applications of often innovative technologies to determine the commercial viability of the technologies to perform their designed function. Demonstrations are generally conducted on well-defined problems for which existing technologies or processes are less than satisfactory in terms of effectiveness, cost, and/or regulatory compliance. Critically important issues in demonstration management include, but are not limited to, such factors as communications with line and matrix management and with the US Department of Energy (DOE) and Energy Systems staff responsible for management oversight, budgetary and schedule requirements, regulatory compliance, and safety

  18. Guidance manual for conducting technology demonstration activities

    Energy Technology Data Exchange (ETDEWEB)

    Jolley, Robert L.; Morris, Michael I.; Singh, Suman P.N.

    1991-12-01

    This demonstration guidance manual has been prepared to assist Martin Marietta Energy Systems, Inc. (Energy Systems), staff in conducting demonstrations. It is prepared in checklist style to facilitate its use and assumes that Energy Systems personnel have project management responsibility. In addition to a detailed step-by-step listing of procedural considerations, a general checklist, logic flow diagram, and several examples of necessary plans are included to assist the user in developing an understanding of the many complex activities required to manage technology demonstrations. Demonstrations are pilot-scale applications of often innovative technologies to determine the commercial viability of the technologies to perform their designed function. Demonstrations are generally conducted on well-defined problems for which existing technologies or processes are less than satisfactory in terms of effectiveness, cost, and/or regulatory compliance. Critically important issues in demonstration management include, but are not limited to, such factors as communications with line and matrix management and with the US Department of Energy (DOE) and Energy Systems staff responsible for management oversight, budgetary and schedule requirements, regulatory compliance, and safety.

  19. Magnetoresponsive conductive colloidal suspensions with magnetized carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, Ahmed M. [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Abdel Fattah, Abdel Rahman [Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Ghosh, Suvojit [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Puri, Ishwar K., E-mail: ikpuri@mcmaster.ca [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2017-01-01

    We synthesize a novel and hitherto unreported class of colloidal suspensions for which the dispersed phase, which consists of multiwall carbon nanotubes (MWNTs) decorated with magnetic nanoparticles (MNPs), is both magnetoresponsive and electrically conductive. Synthesis of the dispersed phase merges processes for producing ferrofluids and magnetic MWNTs (mMWNTs). We explore means to tune the properties of these magnetic conductive colloids (MCCs) by varying the (1) MNP material composition, and (2) MNP:MWNT (w/w) magnetization weight ratio (γ). The mMWNTs are examined using XRD, TEM, EDX and SQUID and MCCs are by measuring their zeta potential and electric conductivity. Magnetite (Fe{sub 3}O{sub 4}) MNPs, which possess a high Curie temperature, produce mMWNTs with high saturation magnetization that respond relatively weakly to temperature variations. Mn{sub 0.2}Cu{sub 0.2}Zn{sub 0.6}Fe{sub 2}O{sub 4} and Cu{sub 0.4}Zn{sub 0.6}Fe{sub 2}O{sub 4} MNPs with lower Curie temperatures are more sensitive to changing temperature. Increasing the MNP Cu content improves the electric conductivity of the corresponding MCC while increasing γ enhances its magnetic response. After γ is raised above a threshold value, mMWNT decoration on the CNT surface becomes nonuniform since the MNPs now agglomerate perpendicular to the nanotube surface. These colloidal suspensions are a promising new class of material that can be manipulated with a magnetic field to tune their electrical conductivity. - Highlights: ●We synthesize a novel and hitherto unreported class of colloidal suspensions. ●These colloidal suspensions are both magnetoresponsive and electrically conductive. ●The dispersed phase consists of MWNTs decorated with different magnetic nanoparticles. ●These colloids have enhanced magnetic response and electric conductivity (up to 169.5 mS cm{sup −1}). ●It is a promising new class of material that can be manipulated with a magnetic field.

  20. Intermittent Contact Alternating Current Scanning Electrochemical Microscopy: A Method for Mapping Conductivities in Solid Li Ion Conducting Electrolyte Samples

    Energy Technology Data Exchange (ETDEWEB)

    Catarelli, Samantha Raisa; Lonsdale, Daniel [Uniscan Instruments Ltd., Macclesfield (United Kingdom); Cheng, Lei [Energy Storage and Distribution Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Materials Sciences and Engineering Department, University of California Berkeley, Berkeley, CA (United States); Syzdek, Jaroslaw [Bio-Logic USA LLC, Knoxville, TN (United States); Doeff, Marca, E-mail: mmdoeff@lbl.gov [Energy Storage and Distribution Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2016-03-31

    Intermittent contact alternating current scanning electrochemical microscopy (ic-ac-SECM) has been used to determine the electrochemical response to an ac signal of several types of materials. A conductive gold foil and insulating Teflon sheet were first used to demonstrate that the intermittent contact function allows the topography and conductivity to be mapped simultaneously and independently in a single experiment. Then, a dense pellet of an electronically insulating but Li ion conducting garnet phase, Al-substituted Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} (LLZO), was characterized using the same technique. The polycrystalline pellet was prepared by classical ceramic sintering techniques and was comprised of large (~150 μm) grains. Critical information regarding the contributions of grain and grain boundary resistances to the total conductivity of the garnet phase was lacking due to ambiguities in the impedance data. In contrast, the use of the ic-ac-SECM technique allowed spatially resolved information regarding local conductivities to be measured directly. Impedance mapping of the pellet showed that the grain boundary resistance, while generally higher than that of grains, varied considerably, revealing the complex nature of the LLZO sample.

  1. Efficacy of Yoga for Vasomotor Symptoms: A Randomized Controlled Trial

    Science.gov (United States)

    Newton, Katherine M.; Reed, Susan D.; Guthrie, Katherine A.; Sherman, Karen J.; Booth-LaForce, Cathryn; Caan, Bette; Sternfeld, Barbara; Carpenter, Janet S.; Learman, Lee A.; Freeman, Ellen W.; Cohen, Lee S.; Joffe, Hadine; Anderson, Garnet L.; Larson, Joseph C.; Hunt, Julie R.; Ensrud, Kristine E.; LaCroix, Andrea Z.

    2013-01-01

    Objective To determine the efficacy of yoga in alleviating VMS frequency and bother. Methods Three by two factorial design, randomized, controlled. Eligible women were randomized to yoga (n=107), exercise (n=106), or usual activity (n=142), and were simultaneously randomized to double-blind comparison of omega-3 fatty acid (n=177) or placebo (n=178) capsules. Yoga intervention was twelve, weekly, 90-minute yoga classes with daily home practice. Primary outcomes were VMS frequency and bother assessed by daily diaries at baseline, 6, and 12 weeks. Secondary outcomes included insomnia symptoms (Insomnia Severity Index) at baseline and 12 weeks. Results Among 249 randomized women, 237 (95%) completed 12-week assessments. Mean baseline VMS frequency was 7.4/day (95% CI 6.6, 8.1) in the yoga group and 8.0/day (95% CI 7.3, 8.7) in the usual activity group. Intent-to-treat analyses included all participants with response data (n=237). There was no difference between intervention groups in change in VMS frequency from baseline to 6 and 12 weeks (mean difference (yoga – usual activity) from baseline −0.3 (95% CI −1.1, 0.5) at 6 weeks and −0.3 (95% CI −1.2, 0.6) at 12 weeks (p=0.119 across both time points). Results were similar for VMS bother. At week 12, yoga was associated with an improvement in insomnia symptoms (mean difference [yoga-usual activity] in change –Insomnia Severity Index, 1.3 [95% CI −2.5, −0.1][p=0.007]). Conclusion Among healthy women, 12 weeks of yoga class plus home practice compared with usual activity did not improve VMS frequency or bother, but reduced insomnia symptoms. PMID:24045673

  2. Forearm cutaneous vascular and sudomotor responses to whole body passive heat stress in young smokers.

    Science.gov (United States)

    Moyen, Nicole E; Anderson, Hannah M; Burchfield, Jenna M; Tucker, Matthew A; Gonzalez, Melina A; Robinson, Forrest B; Ganio, Matthew S

    2015-07-01

    The purpose of this study was to compare smokers and nonsmokers' sudomotor and cutaneous vascular responses to whole body passive heat stress. Nine regularly smoking (SMK: 29 ± 9 yr; 10 ± 6 cigarettes/day) and 13 nonsmoking (N-SMK: 27 ± 8 yr) males were passively heated until core temperature (TC) increased 1.5°C from baseline. Forearm local sweat rate (LSR) via ventilated capsule, sweat gland activation (SGA), sweat gland output (SGO), and cutaneous vasomotor activity via laser-Doppler flowmetry (CVC) were measured as mean body temperature increased (ΔTb) during passive heating using a water-perfused suit. Compared with N-SMK, SMK had a smaller ΔTb at the onset of sweating (0.52 ± 0.19 vs. 0.35 ± 0.14°C, respectively; P = 0.03) and cutaneous vasodilation (0.61 ± 0.21 vs. 0.31 ± 0.12°C, respectively; P body heating was higher in N-SMK vs. SMK (1.00 ± 0.13 vs. 0.79 ± 0.26 mg·cm(-2)·min(-1); P = 0.03), which was likely a result of higher SGO (8.94 ± 3.99 vs. 5.94 ± 3.49 μg·gland(-1)·min(-1), respectively; P = 0.08) and not number of SGA (104 ± 7 vs. 121 ± 9 glands/cm(2), respectively; P = 0.58). During whole body passive heat stress, smokers had an earlier onset for forearm sweating and cutaneous vasodilation, but a lower local sweat rate that was likely due to lower sweat output per gland. These data provide insight into local (i.e., forearm) thermoregulatory responses of young smokers during uncompensatory whole body passive heat stress. Copyright © 2015 the American Physiological Society.

  3. Water-Enabled Healing of Conducting Polymer Films.

    Science.gov (United States)

    Zhang, Shiming; Cicoira, Fabio

    2017-10-01

    The conducting polymer polyethylenedioxythiophene doped with polystyrene sulfonate (PEDOT:PSS) has become one of the most successful organic conductive materials due to its high air stability, high electrical conductivity, and biocompatibility. In recent years, a great deal of attention has been paid to its fundamental physicochemical properties, but its healability has not been explored in depth. This communication reports the first observation of mechanical and electrical healability of PEDOT:PSS thin films. Upon reaching a certain thickness (about 1 µm), PEDOT:PSS thin films damaged with a sharp blade can be electrically healed by simply wetting the damaged area with water. The process is rapid, with a response time on the order of 150 ms. Significantly, after being wetted the films are transformed into autonomic self-healing materials without the need of external stimulation. This work reveals a new property of PEDOT:PSS and enables its immediate use in flexible and biocompatible electronics, such as electronic skin and bioimplanted electronics, placing conducting polymers on the front line for healing applications in electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Testing a linear time invariant model for skin conductance responses by intraneural recording and stimulation.

    Science.gov (United States)

    Gerster, Samuel; Namer, Barbara; Elam, Mikael; Bach, Dominik R

    2018-02-01

    Skin conductance responses (SCR) are increasingly analyzed with model-based approaches that assume a linear and time-invariant (LTI) mapping from sudomotor nerve (SN) activity to observed SCR. These LTI assumptions have previously been validated indirectly, by quantifying how much variance in SCR elicited by sensory stimulation is explained under an LTI model. This approach, however, collapses sources of variability in the nervous and effector organ systems. Here, we directly focus on the SN/SCR mapping by harnessing two invasive methods. In an intraneural recording experiment, we simultaneously track SN activity and SCR. This allows assessing the SN/SCR relationship but possibly suffers from interfering activity of non-SN sympathetic fibers. In an intraneural stimulation experiment under regional anesthesia, such influences are removed. In this stimulation experiment, about 95% of SCR variance is explained under LTI assumptions when stimulation frequency is below 0.6 Hz. At higher frequencies, nonlinearities occur. In the intraneural recording experiment, explained SCR variance is lower, possibly indicating interference from non-SN fibers, but higher than in our previous indirect tests. We conclude that LTI systems may not only be a useful approximation but in fact a rather accurate description of biophysical reality in the SN/SCR system, under conditions of low baseline activity and sporadic external stimuli. Intraneural stimulation under regional anesthesia is the most sensitive method to address this question. © 2017 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  5. Hidden Markov Item Response Theory Models for Responses and Response Times.

    Science.gov (United States)

    Molenaar, Dylan; Oberski, Daniel; Vermunt, Jeroen; De Boeck, Paul

    2016-01-01

    Current approaches to model responses and response times to psychometric tests solely focus on between-subject differences in speed and ability. Within subjects, speed and ability are assumed to be constants. Violations of this assumption are generally absorbed in the residual of the model. As a result, within-subject departures from the between-subject speed and ability level remain undetected. These departures may be of interest to the researcher as they reflect differences in the response processes adopted on the items of a test. In this article, we propose a dynamic approach for responses and response times based on hidden Markov modeling to account for within-subject differences in responses and response times. A simulation study is conducted to demonstrate acceptable parameter recovery and acceptable performance of various fit indices in distinguishing between different models. In addition, both a confirmatory and an exploratory application are presented to demonstrate the practical value of the modeling approach.

  6. The effect of vapour pressure deficit on stomatal conductance, sap pH and leaf-specific hydraulic conductance in Eucalyptus globulus clones grown under two watering regimes.

    Science.gov (United States)

    Hernandez, Maria Jose; Montes, Fernando; Ruiz, Federico; Lopez, Gustavo; Pita, Pilar

    2016-05-01

    Stomatal conductance has long been considered of key interest in the study of plant adaptation to water stress. The expected increase in extreme meteorological events under a climate change scenario may compromise survival in Eucalyptus globulus plantations established in south-western Spain. We investigated to what extent changes in stomatal conductance in response to high vapour pressure deficits and water shortage are mediated by hydraulic and chemical signals in greenhouse-grown E. globulus clones. Rooted cuttings were grown in pots and submitted to two watering regimes. Stomatal conductance, shoot water potential, sap pH and hydraulic conductance were measured consecutively in each plant over 4 weeks under vapour pressure deficits ranging 0·42 to 2·25 kPa. Evapotranspiration, growth in leaf area and shoot biomass were also determined. There was a significant effect of both clone and watering regime in stomatal conductance and leaf-specific hydraulic conductance, but not in sap pH. Sap pH decreased as water potential and stomatal conductance decreased under increasing vapour pressure deficit. There was no significant relationship between stomatal conductance and leaf-specific hydraulic conductance. Stomata closure precluded shoot water potential from falling below -1·8 MPa. The percentage loss of hydraulic conductance ranged from 40 to 85 %. The highest and lowest leaf-specific hydraulic conductances were measured in clones from the same half-sib families. Water shortage reduced growth and evapotranspiration, decreases in evapotranspiration ranging from 14 to 32 % in the five clones tested. Changes in sap pH seemed to be a response to changes in atmospheric conditions rather than soil water in the species. Stomata closed after a considerable amount of hydraulic conductance was lost, although intraspecific differences in leaf-specific hydraulic conductance suggest the possibility of selection for improved productivity under water-limiting conditions

  7. Pravastatin and endothelium dependent vasomotion after coronary angioplasty: the PREFACE trial.

    Science.gov (United States)

    Mulder, H J; Schalij, M J; Kauer, B; Visser, R F; van Dijkman, P R; Jukema, J W; Zwinderman, A H; Bruschke, A V

    2001-11-01

    To test the hypothesis that the 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor pravastatin ameliorates endothelium mediated responses of dilated coronary segments: the PREFACE (pravastatin related effects following angioplasty on coronary endothelium) trial. A double blind, randomised, placebo controlled, multicentre study. Four hospitals in the Netherlands. 63 non-smoking, non-hypercholesterolaemic patients scheduled for elective balloon angioplasty (pravastatin 34, placebo 29). The effects of three months of pravastatin treatment (40 mg daily) on endothelium dependent vasomotor function were studied. Balloon angioplasty was undertaken one month after randomisation, and coronary vasomotor function tests using acetylcholine were performed two months after balloon angioplasty. The angiograms were analysed quantitatively. The efficacy measure was the acetylcholine induced change in mean arterial diameter, determined in the dilated segment and in an angiographically normal segment of an adjacent non-manipulated coronary artery. Increasing acetylcholine doses produced vasoconstriction in the dilated segments (p = 0.004) but not in the normal segments. Pravastatin did not affect the vascular response to acetylcholine in either the dilated segments (p = 0.09) or the non-dilated sites. Endothelium dependent vasomotion in normal segments was correlated with that in dilated segments (r = 0.47, p < 0.001). There were fewer procedure related events in the pravastatin group than in the placebo group (p < 0.05). Endothelium dependent vasomotion in normal segments is correlated with that in dilated segments. A significant beneficial effect of pravastatin on endothelial function could not be shown, but in the dilated segments there was a trend towards a beneficial treatment effect in the pravastatin group.

  8. Wireless Sensing System Using Open-circuit, Electrically-conductive Spiral-trace Sensor

    Science.gov (United States)

    Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)

    2013-01-01

    A wireless sensing system includes a sensor made from an electrical conductor shaped to form an open-circuit, electrically-conductive spiral trace having inductance and capacitance. In the presence of a time-varying magnetic field, the sensor resonates to generate a harmonic response having a frequency, amplitude and bandwidth. A magnetic field response recorder wirelessly transmits the time-varying magnetic field to the sensor and wirelessly detects the sensor's response frequency, amplitude and bandwidth.

  9. The hydraulic conductivity of sediments: A pore size perspective

    KAUST Repository

    Ren, X.W.; Santamarina, Carlos

    2017-01-01

    in the void ratio is higher than the theoretical value due to two concurrent phenomena: 1) percolating large pores are responsible for most of the flow, and 2) the larger pores close first during compaction. The prediction of hydraulic conductivity based

  10. In-pile Thermal Conductivity Characterization with Time Resolved Raman

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xinwei [Iowa State Univ., Ames, IA (United States). Dept. of Mechanical Engineering; Hurley, David H. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2018-03-19

    The project is designed to achieve three objectives: (1) Develop a novel time resolved Raman technology for direct measurement of fuel and cladding thermal conductivity. (2) Validate and improve the technology development by measuring ceramic materials germane to the nuclear industry. (3) Conduct instrumentation development to integrate optical fiber into our sensing system for eventual in-pile measurement. We have developed three new techniques: time-domain differential Raman (TD-Raman), frequency-resolved Raman (FR-Raman), and energy transport state-resolved Raman (ET-Raman). The TD-Raman varies the laser heating time and does simultaneous Raman thermal probing, the FR-Raman probes the material’s thermal response under periodical laser heating of different frequencies, and the ET-Raman probes the thermal response under steady and pulsed laser heating. The measurement capacity of these techniques have been fully assessed and verified by measuring micro/nanoscale materials. All these techniques do not need the data of laser absorption and absolute material temperature rise, yet still be able to measure the thermal conductivity and thermal diffusivity with unprecedented accuracy. It is expected they will have broad applications for in-pile thermal characterization of nuclear materials based on pure optical heating and sensing.

  11. Combined KHFAC + DC nerve block without onset or reduced nerve conductivity after block

    Science.gov (United States)

    Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-10-01

    Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even completely prevent the KHFAC onset response without a change in nerve conductivity.

  12. 13 CFR 105.101 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-01-01

    ... ethical conduct standards and financial disclosure regulations. 105.101 Section 105.101 Business Credit... RESPONSIBILITIES Standards of Conduct § 105.101 Cross-reference to employee ethical conduct standards and financial... to the Standards of Ethical Conduct for Employees of the Executive Branch at 5 CFR part 2635 and the...

  13. 49 CFR 99.735-1 - Cross-reference to ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Cross-reference to ethical conduct standards and... Transportation EMPLOYEE RESPONSIBILITIES AND CONDUCT General § 99.735-1 Cross-reference to ethical conduct... the executive branch-wide Standards of Ethical Conduct at 5 CFR part 2635, the Department of...

  14. 22 CFR 1001.1 - Cross-references to employee ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Cross-references to employee ethical conduct... FOUNDATION EMPLOYEE RESPONSIBILITIES AND CONDUCT § 1001.1 Cross-references to employee ethical conduct... Foundation should refer to the Standards of Ethical Conduct for Employees of the Executive Branch at 5 CFR...

  15. 22 CFR 1504.1 - Cross-references to employee ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Cross-references to employee ethical conduct... FOUNDATION EMPLOYEE RESPONSIBILITIES AND CONDUCT § 1504.1 Cross-references to employee ethical conduct... Foundation are subject to the Standards of Ethical Conduct for Employees of the Executive Branch at 5 CFR...

  16. 45 CFR 1105.1 - Cross-reference to employee ethical conduct standards and financial disclosure and financial...

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cross-reference to employee ethical conduct... STANDARDS OF CONDUCT FOR EMPLOYEES § 1105.1 Cross-reference to employee ethical conduct standards and... ethical conduct at 5 CFR part 2635; the executive branch employees responsibilities and conduct...

  17. Role of the medulla oblongata in normal and high arterial blood pressure regulation: the contribution of Escola Paulista de Medicina - UNIFESP.

    Science.gov (United States)

    Cravo, Sergio L; Campos, Ruy R; Colombari, Eduardo; Sato, Mônica A; Bergamaschi, Cássia M; Pedrino, Gustavo R; Ferreira-Neto, Marcos L; Lopes, Oswaldo U

    2009-09-01

    Several forms of experimental evidence gathered in the last 37 years have unequivocally established that the medulla oblongata harbors the main neural circuits responsible for generating the vasomotor tone and regulating arterial blood pressure. Our current understanding of this circuitry derives mainly from the studies of Pedro Guertzenstein, a former student who became Professor of Physiology at UNIFESP later, and his colleagues. In this review, we have summarized the main findings as well as our collaboration to a further understanding of the ventrolateral medulla and the control of arterial blood pressure under normal and pathological conditions.

  18. Liquid-like thermal conduction in intercalated layered crystalline solids

    Science.gov (United States)

    Li, B.; Wang, H.; Kawakita, Y.; Zhang, Q.; Feygenson, M.; Yu, H. L.; Wu, D.; Ohara, K.; Kikuchi, T.; Shibata, K.; Yamada, T.; Ning, X. K.; Chen, Y.; He, J. Q.; Vaknin, D.; Wu, R. Q.; Nakajima, K.; Kanatzidis, M. G.

    2018-03-01

    As a generic property, all substances transfer heat through microscopic collisions of constituent particles1. A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations2,3. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe2. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.

  19. Optical conductivity of the Hubbard model

    International Nuclear Information System (INIS)

    Vicente Alvarez, J.J.; Balseiro, C.A.; Ceccatto, H.A.

    1996-07-01

    We study the response to a static electric field (charge stiffness) and the frequency-dependent conductivity of the Hubbard model in a resonant-valence-bond-type paramagnetic phase. This phase is described by means of a charge and spin rotational-invariant approach, based on a mixed fermion-boson representation of the original strongly correlated electrons. We found that the Mott transition at half filling is well described by the charge stiffness behaviour, and that the values for this quantity off half filling agree reasonably well with numerical results. Furthermore, for the frequency-dependent conductivity we trace back the origin of the band which appears inside the Hubbard gap to magnetic pair breaking. This points to a magnetic origin of midinfrared band in high-T c compounds, with no relation to superconductivity. (author). 12 refs, 2 tabs

  20. Characterization of CGRP(1) receptors in the guinea pig basilar artery

    DEFF Research Database (Denmark)

    Jansen-Olesen, I; Kaarill, L; Edvinsson, L

    2001-01-01

    The purpose of the present study was to characterise receptors mediating calcitonin gene-related peptide (CGRP)-induced relaxation of guinea pig basilar artery. This was done by investigating vasomotor responses in vitro and performing autoradiographic binding studies. We also intended to study...... the importance of an intact endothelium. Agonist studies showed that peptides of the CGRP family induced relaxation of the guinea pig basilar artery with the following order of potency: human beta-CGRP=human alpha-CGRP>adrenomedullin=[acetamidomethyl-Cys(2,7)]alpha-human CGRP ([Cys(ACM)(2,7)]CGRP...... in the absence of human CGRP-(8-37). The study shows the presence of a relaxant CGRP(1) receptor on the smooth muscle cells of guinea pig basilar artery. Various endothelial factors did not influence relaxant responses....

  1. Factors associated with poor sleep during menopause: results from the Midlife Women's Health Study.

    Science.gov (United States)

    Smith, Rebecca L; Flaws, Jodi A; Mahoney, Megan M

    2018-05-01

    Poor sleep is one of the most common problems reported during menopause, and is known to vary throughout the menopause transition. The objective of this study was to describe the dynamics of poor sleep among participants of the Midlife Women's Health Study and to identify risk factors associated with poor sleep during the menopausal transition. Annual responses to surveys that included questions about the frequency of sleep disturbances and insomnia were analyzed to determine the likelihood of persistent poor sleep throughout the menopausal transition and the correlation of responses to the different sleep-related questions, including frequency of restless sleep during the first year of the study. Responses to questions about a large number of potential risk factors were used to identify risk factors for poor sleep. Poor sleep in premenopause was not predictive of poor sleep in perimenopause, and poor sleep in perimenopause was not predictive of poor sleep in postmenopause. Frequencies of each of the measures of poor sleep were highly correlated. For all sleep outcomes, high frequency of depression was related to a high frequency of poor sleep. Vasomotor symptoms were also significantly related with a higher frequency of all poor sleep outcomes. A history of smoking was also associated with higher frequencies of insomnia and sleep disturbances. The risk factors identified for poor sleep, depression and vasomotor symptoms, were consistently associated with poor sleep throughout the menopausal transition. The likelihood of these risk factors changed from premenopause, through perimenopause, and into postmenopause, however, which could explain changes in sleep difficulties across the menopausal transition. Treatment of these risk factors should be considered when addressing sleep difficulties in menopausal women. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Conduct disorders.

    Science.gov (United States)

    Buitelaar, Jan K; Smeets, Kirsten C; Herpers, Pierre; Scheepers, Floor; Glennon, Jeffrey; Rommelse, Nanda N J

    2013-02-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic and therapeutic approaches to CD in the light of the forthcoming DSM-5 definition. The diagnostic criteria for CD will remain unchanged in DSM-5, but the introduction of a specifier of CD with a callous-unemotional (CU) presentation is new. Linked to this, we discuss the pros and cons of various other ways to subtype aggression/CD symptoms. Existing guidelines for CD are, with few exceptions, already of a relatively older date and emphasize that clinical assessment should be systematic and comprehensive and based on a multi-informant approach. Non-medical psychosocial interventions are recommended as the first option for the treatment of CD. There is a role for medication in the treatment of comorbid syndromes and/or in case of insufficient response to psychosocial interventions and severe and dangerous aggressive and violent behaviours.

  3. A reversible conductivity modulation of azobenzene-based ionic liquids in aqueous solutions using UV/vis light.

    Science.gov (United States)

    Li, Zhiyong; Yuan, Xiaoqing; Feng, Ying; Chen, Yongkui; Zhao, Yuling; Wang, Huiyong; Xu, Qingli; Wang, Jianji

    2018-05-09

    Photo-induced conductivity modulation of stimuli-responsive materials is of great importance from the viewpoint of fundamental research and technology. In this work, 5 new kinds of azobenzene-based photo-responsive ionic liquids were synthesized and characterized, and UV/vis light modulation of their conductivity was investigated in an aqueous solution. The factors affecting the conductivity modulation of the photo-responsive fluids, such as photo-isomerization efficiency, photo-regulation aggregation, concentration and chemical structure of the ionic liquids, were examined systematically. It was found that the conductivity of the ionic liquids in water exhibited a significant increase upon UV light irradiation and the ionic liquids with a shorter alkyl spacer in the cation showed a more remarkable photo-induced conductivity enhancement with a maximum increase of 150%. In addition, the solution conductivity was restored (or very close) to the initial value upon an alternative irradiation with visible light. Thus, the solution conductivity can be modulated using alternative irradiation with UV and visible light. Although the reversible photo-isomerization of the azobenzene group under UV/vis irradiation is the origin of the conductivity modulation, the photo-regulated aggregation of the ionic liquid in water is indispensable for the maximum degree of conductivity modulation because UV irradiation can weaken, even break the aggregated cis-isomers of the ionic liquids in an aqueous solution.

  4. Diphenylhydantoin and lidocaine modification of A-V conduction in halothane-anesthetized dogs.

    Science.gov (United States)

    Atlee, J L; Homer, L D; Tobey, R E

    1975-07-01

    The effect of halothane on A-V conduction was evaluated in gods during atrial pacing using the technique of His-bundle electrocardiography. In addition, the effects of lidocaine and diphenylkydantoin (DPH) on A-V conuction were examined during halothane anesthesia. Effects of these drugs on three subintervals of A-V conduction were compared. These included the -H (stimulus atifact of His-bundle deflection-atrioventricular conduction), H-Q (His-budnle deflection onset of QRS complex-His-Purkinje conduction), and H-S intervals(His-bundle delfection to end of QRS COmplex-total intraventricular conduction). Linear regression best described the relationship between duration of interval (P-H, H-V,and H-S) and heart rate during incremental increases in the atrial paced rate. Data from these experiments were fitted to a multiple lenear regression model that predicted the effect of increasing concentrations of halothan, lidocaine, and DPH on slope and intercept coefficients. In creasing concentrations of halothan ( 30 and 45 mg/100 ml arterial). Both lidocaine and DPH further depressed conduction at all levels of halothan anesthesia. The P-H interval was particularly sensitive todrug effefts. This may represent potentiation of the normal slowing of conduction through the AVnode in response to incremental increases in heart rate (fatigue response.) We conclude thatboth lidocaine and DPH fail to reverse the depressant effect of halothane on A-V conduction. This may explain their ineffectiveness in treating certain types of arrhythmias during halothane anesthesia.

  5. Cognitive styles in depressed children with and without comorbid conduct disorder.

    Science.gov (United States)

    Schepman, Karen; Fombonne, Eric; Collishaw, Stephan; Taylor, Eric

    2014-07-01

    Little is known about patterns of cognitive impairment in depression comorbid with conduct disorder. The study included clinically depressed children with (N = 23) or without conduct disorder (N = 29), and controls without psychiatric disorder (N = 37). Cognitive biases typical of depression and patterns of social information processing were assessed. Both depressed groups had substantially higher rates of negative cognitive distortions, attributional biases and ruminative responses than non-depressed children. Children in the comorbid group made more hostile attributions and suggested more aggressive responses for dealing with threatening social situations, whilst children with depression only were more likely to be unassertive. Depression has a number of similar depressotypic cognitive biases whether or not complicated by conduct disorder, and may be potentially susceptible to similar interventions. The results also highlight the importance of recognising social information processing deficits when they occur and targeting those too, especially in comorbid presentations. Copyright © 2014. Published by Elsevier Ltd.

  6. Study on a Haptic Sensor Using MCF (Magnetic Compound Fluid) Electric Conductive Rubber

    Science.gov (United States)

    Zheng, Yaoyang; Shimada, Kunio

    To provide a new composite material having a high degree of sensitivity regarding both electrical conduction and temperature for the field of robotics or sensing, we have developed magnetic rubber that contains a network-like magnetic cluster. We compared the temperature response of MCF rubber with others rubbers made under various experimental conditions, allowing us to find an optimum condition for making MCF rubber. The temperature response was obtained by an experimental equation. We also compared the electric conductivity of MCF rubber with that of ordinary electric conductive rubber and found that its electric sensitivity was lower at a small deformation, but increased at larger deformations. Therefore, MCF rubber has proven itself effective as a switching sensor when a small deformation is applied.

  7. Conducted vasoconstriction in rat mesenteric arterioles: role for dihydropyridine-insensitive Ca(2+) channels

    DEFF Research Database (Denmark)

    Gustafsson, F; Andreasen, D; Salomonsson, Max

    2001-01-01

    The aim of this study was to evaluate the role of voltage-operated Ca(2+) channels in the initiation and conduction of vasoconstrictor responses to local micropipette electrical stimulation of rat mesenteric arterioles (28 +/- 1 microm, n = 79) in vivo. Local and conducted (600 microm upstream from...... the pipette) vasoconstriction was not blocked by TTX (1 micromol/l, n = 5), nifedipine, or nimodipine (10 micromol/l, n = 9). Increasing the K(+) concentration of the superfusate to 75 mmol/l did not evoke vasoconstriction, but this depolarizing stimulus reversibly abolished vasoconstrictor responses...

  8. Fused silica thermal conductivity dispersion at high temperature

    International Nuclear Information System (INIS)

    Bouchut, P.; Decruppe, D.; Delrive, L.

    2004-01-01

    A continuous CO 2 laser is focused to locally anneal small fused silica spots. A noncontact radiometry diagnostic enables us to follow surface temperature variation that occurs from site to site. A 'steady state' dispersion of surface temperature is observed across our sample. We show that nonhomogeneous silica thermal conductivity, above 1000 K is responsible for this temperature dispersion

  9. Doping dependence of electrical and thermal conductivity of nanoscale polyaniline thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jin Jiezhu; Wang Qing [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Haque, M A [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

    2010-05-26

    We performed simultaneous characterization of electrical and thermal conductivity of 55 nm thick polyaniline (PANI) thin films doped with different levels of camphor sulfonic acids (CSAs). The effect of the doping level is more pronounced on electrical conductivity than on thermal conductivity of PANIs, thereby greatly affecting their ratio that determines the thermoelectric efficiency. At the 60% (the molar ratio of CSA to phenyl-N repeat unit of PANI) doping level, PANI exhibited the maximum electrical and thermal conductivity due to the formation of mostly delocalized structures. Whereas polarons are the charge carriers responsible for the electrical conduction, phonons are believed to play a dominant role in the heat conduction in nanoscale doped PANI thin films.

  10. Setting new global rules? : TNCs and codes of conduct

    NARCIS (Netherlands)

    Kolk, A.; van Tulder, R.

    2005-01-01

    The introduction of codes of conduct can be seen as an expression of corporate social responsibility, but also as rule-setting behaviour - attempts to help fill some of the existing international instutitional voids. To shed light on these aspects and the (potential) effectiveness of codes, this

  11. 45 CFR 706.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cross-references to employee ethical conduct... 706.1 Public Welfare Regulations Relating to Public Welfare (Continued) COMMISSION ON CIVIL RIGHTS EMPLOYEE RESPONSIBILITIES AND CONDUCT § 706.1 Cross-references to employee ethical conduct standards...

  12. Melatonin attenuates thiocyanate-induced vasoconstriction in aortic rings

    Directory of Open Access Journals (Sweden)

    Alexander M. Prusa

    2017-11-01

    Full Text Available Cigarette smoking not only has a carcinogenic effect but also leads to an increase in arterial blood pressure. Besides its main components, i.e. nicotine, tar, and carbon monoxide, cigarette smoke also contains thiocyanate. Thiocyanate anions (SCN− arise from the detoxification of hydrogen cyanide and its plasma concentrations were found to correlate significantly with cigarette consumption. There is also evidence that atherosclerotic disease progression is much more rapid when serum SCN− levels are increased. Melatonin, a non-toxic indolamine with various physiologic functions, is believed to protect against inflammatory processes and oxidative stress. It has been demonstrated that melatonin serves as free radical scavenger and represents a potent antioxidant. Therefore, it is believed that melatonin with its atheroprotective effects may be useful either as a sole therapy or in conjunction with others. The aim of this study was to quantify the thiocyanate-induced vasomotor response in aortic tissue and further to examine the potential of melatonin in affecting the generated vasoreactivity. Aortic rings of adult male normotensive Wistar rats were cut into 4-mm rings. Following the administration of thiocyanate in various concentrations, vasomotor response of aortic vessel segments was measured. To assess the effect of melatonin on vasomotor activity, organ bath concentrations were modulated from 60 to 360 pM, which corresponds to physiologic plasma up to the levels of patients with regular oral intake of 3 mg of melatonin as a supplement. Thirty-six rat aortic rings were studied. When exposed to thiocyanate, vessel segments revealed vasoconstriction in a concentration-dependent manner. In rings which were preincubated with melatonin at a concentration of 360 pM, a 56.5% reduction of effect size could be achieved (4.09 ± 1.22 mN versus 9.41 ± 1.74 mN, P < 0.0001. Additionally, administration of 360 pM melatonin at a

  13. Conducting Polymers Functionalized with Phthalocyanine as Nitrogen Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    S. D. Deshpande

    2002-05-01

    Full Text Available The conducting polymers such as polyaniline, polypyrrole and polythiophene were functionalized with copper phthalocyanine using chemical oxidation method. The obtained polymers viz. PANI-CuPc, PPy-CuPc and PT-CuPc were studied as chemical sensors by their response characteristics after exposure to various chemical vapors such as methanol, ammonia and nitrogen dioxide. The results obtained showed that these polymers have moderate sensitivity towards the methanol as well as ammonia vapors whereas they show tremendous sensitivity towards nitrogen dioxide vapors. The sensitivity factor of as high as 50,000 was obtained for PT-CuPc polymers in nitrogen dioxide. In comparison to this, the sensitivity factors of about 100 and 40 were obtained, when these polymers were exposed to ammonia and methanol vapors. The very high selectivity towards the nitrogen dioxide was explained on the basis of charge transfer complex formed between, the phthalocyanine donor and nitrogen dioxide acceptor molecules. On the other hand, ammonia becomes a competing electron donor in CuPc containing conducting polymers. The very low response towards the methanol may be explained on the basis very little charge transfer / interaction between CuPc containing polymers and methanol. Thus, CuPc incorporated conducting polymers have much higher selectivity than their original homopolymer.

  14. Dielectric and conducting behaviour of polycrystalline holmium octa-molybdate

    International Nuclear Information System (INIS)

    Want, Basharat; Zahoor Ahmad, Bhat; Hamid Bhat, Bilal

    2014-01-01

    Polycrystalline holmium octa-molybdate spherulites have been obtained by using gel diffusion technique and characterized by different physio-chemical techniques. The surfaces of these spherulites are composed of nano-rod with an average diameter of about 80 nm. At room temperature the initial crystal structure is triclinic, space group P1. Thermal studies suggested a phase transition occurring in holmium octa-molybdate crystals at about 793 K. The electrical properties of the system have been studied as a function of frequency and temperature in the ranges of 20 Hz–3 MHz and 290–570 K, respectively. A giant dielectric constant and two loss peaks have been observed in the permittivity formalism. The conducting behaviour of the material is also discussed. The conductivity was found to be 1572 μ Ω −1 m −1 at room temperature and 3 MHz frequency. The conductivity of the polycrystalline material was attributed to the fact that it arises due to the migration of defects on the oxygen sub-lattice. Impedance studies were also performed in the frequency domain to infer the bulk and grain boundary contributions to the overall electric response of the material. The electrical responses have been attributed to the grain, grain-boundary, and interfacial effects. (paper)

  15. Callous-unemotional, impulsive-irresponsible, and grandiose-manipulative traits: Distinct associations with heart rate, skin conductance, and startle responses to violent and erotic scenes.

    Science.gov (United States)

    Fanti, Kostas A; Kyranides, Melina N; Georgiou, Giorgos; Petridou, Maria; Colins, Olivier F; Tuvblad, Catherine; Andershed, Henrik

    2017-05-01

    The present study aimed to examine whether callous-unemotional, grandiose-manipulative, and impulsive-irresponsible dimensions of psychopathy are differentially related to various affective and physiological measures, assessed at baseline and in response to violent and erotic movie scenes. Data were collected from young adults (N = 101) at differential risk for psychopathic traits. Findings from regression analyses revealed a unique predictive contribution of grandiose-manipulative traits in particular to higher ratings of positive valence for violent scenes. Callous-unemotional traits were uniquely associated with lower levels of sympathy toward victims and lower ratings of fear and sadness during violent scenes. All three psychopathy dimensions and the total psychopathy scale showed negative zero-order correlations with heart rate at baseline, but regression analyses revealed that only grandiose manipulation was uniquely predictive of lower baseline heart rate. Grandiose manipulation was also significantly associated with lower baseline skin conductance. Regarding autonomic activity, findings resulted in a unique negative association between grandiose manipulation and heart rate activity in response to violent scenes. In contrast, the impulsive-irresponsible dimension was positively related with heart rate activity to violent scenes. Finally, findings revealed that only callous-unemotional traits were negatively associated with startle potentiation in response to violent scenes. No associations during erotic scenes were identified. These findings point to unique associations between the three assessed dimensions of psychopathy with physiological measures, indicating that grandiose manipulation is associated with hypoarousal, impulsive irresponsibility with hyperarousal, and callous-unemotional traits with low emotional and fear responses to violent scenes. © 2017 Society for Psychophysiological Research.

  16. Conductivity-limiting bipolar thermal conductivity in semiconductors

    Science.gov (United States)

    Wang, Shanyu; Yang, Jiong; Toll, Trevor; Yang, Jihui; Zhang, Wenqing; Tang, Xinfeng

    2015-01-01

    Intriguing experimental results raised the question about the fundamental mechanisms governing the electron-hole coupling induced bipolar thermal conduction in semiconductors. Our combined theoretical analysis and experimental measurements show that in semiconductors bipolar thermal transport is in general a “conductivity-limiting” phenomenon, and it is thus controlled by the carrier mobility ratio and by the minority carrier partial electrical conductivity for the intrinsic and extrinsic cases, respectively. Our numerical method quantifies the role of electronic band structure and carrier scattering mechanisms. We have successfully demonstrated bipolar thermal conductivity reduction in doped semiconductors via electronic band structure modulation and/or preferential minority carrier scatterings. We expect this study to be beneficial to the current interests in optimizing thermoelectric properties of narrow gap semiconductors. PMID:25970560

  17. 12 CFR 1401.1 - Cross-references to employee ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Cross-references to employee ethical conduct... INSURANCE CORPORATION EMPLOYEE RESPONSIBILITIES AND CONDUCT § 1401.1 Cross-references to employee ethical... the Farm Credit System Insurance Corporation are subject to the Standards of Ethical Conduct for...

  18. 22 CFR 1100.1 - Cross-references to employee ethical conduct standards, financial disclosure and financial...

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Cross-references to employee ethical conduct... STATES SECTION EMPLOYEE RESPONSIBILITIES AND CONDUCT § 1100.1 Cross-references to employee ethical... executive branch standards of ethical conduct contained in 5 CFR part 2635, the executive branch financial...

  19. Measurement of conductive hearing loss in mice.

    Science.gov (United States)

    Qin, Zhaobing; Wood, Melissa; Rosowski, John J

    2010-05-01

    In order to discriminate conductive hearing loss from sensorineural impairment, quantitative measurements were used to evaluate the effect of artificial conductive pathology on distortion-product otoacoustic emissions (DPOAEs), auditory brainstem responses (ABRs) and laser-Doppler vibrometry (LDV) in mice. The conductive manipulations were created by perforating the pars flaccida of the tympanic membrane, filling or partially filling the middle-ear cavity with saline, fixing the ossicular chain, and interrupting the incudo-stapedial joint. In the saline-filled and ossicular-fixation groups, averaged DPOAE thresholds increased relative to the control state by 20-36 and 25-39 dB, respectively with the largest threshold shifts occurring at frequencies less than 20kHz, while averaged ABR thresholds increased 12-19 and 12-25 dB, respectively without the predominant low-frequency effect. Both DPOAE and ABR thresholds were elevated by less than 10 dB in the half-filled saline condition; no significant change was observed after pars flaccida perforation. Conductive pathology generally produced a change in DPOAE threshold in dB that was 1.5-2.5 times larger than the ABR threshold change at frequencies less than 30 kHz; the changes in the two thresholds were nearly equal at the highest frequencies. While mild conductive pathology (ABR threshold shifts of conductive hearing losses (ABR threshold shifts >10 dB) were associated with significant deceases in DPOAE growth rate. Our LDV measurements are consistent with others and suggest that measurements of umbo velocity are not an accurate indicator of conductive hearing loss produced by ossicular lesions in mice. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  20. Prediction of thermal conductivity of sedimentary rocks from well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    2014-01-01

    The calculation of heat-flow density in boreholes requires reliable values for the change of temperature and rock thermal conductivity with depth. As rock samples for laboratory measurements of thermal conductivity (TC) are usually rare geophysical well logs are used alternatively to determine TC...... parameters (i.e. thermal conductivity, density, hydrogen index, sonic interval transit time, gamma-ray response, photoelectric factor) of artificial mineral assemblages consisting 15 rock-forming minerals that are used in different combinations to typify sedimentary rocks. The predictive capacity of the new...... equations is evaluated on subsurface data from four boreholes drilled into the Mesozoic sequence of the North German Basin, including more than 1700 laboratory-measured thermal-conductivity values. Results are compared with those from other approaches published in the past. The new approach predicts TC...

  1. Zeaxanthin concentrations co-segregate with the magnitude of the blue light response of adaxial guard cells and leaf stomatal conductances in an F2 population of pima cotton

    Energy Technology Data Exchange (ETDEWEB)

    Quinones, M.A.; Lu Zhenmin; Zeiger, E. (Univ. of California, Los Angeles (United States))

    1993-05-01

    A blue light (BL) response of adaxial (AD) guard cells was investigated in two cotton lines with contrasting rates of stomatal conductances (g). This response is expressed as an enhancement of the red light-induced chlorophyll a fluorescence quenching by BL, and has an action spectrum indicative of a carotenoid photoreceptor. Ad guard cell from the high g, advanced line Pima S-6 have a higher carotenoid content and a larger BL response than those from the low g, primitive cotton, B368. In a growth chamber-grown F2 population of a cross between the two lines (n=30), g of individual plants segregated over a range exceeding the average g of the parental populations. Carotenoid content and the BL response of ad guard cell also segregated. There was a positive, strong correlation (r=0.71) between leaf g and the magnitude of the BL response of ad guard cells, indicating that both parameters are under genetic control, and that the BL response of guard cells contributes to the modulation of g. The concentration of all xanthopylls and [beta]-carotene in the ad guard cells correlated poorly with the BL response, except for zeaxanthin (r=0.71). In all green systems, xanthophylls are located inside the chloroplast which suggests that zeaxanthin functions in these organelle as a blue light photoreceptor for cotton guard cells.

  2. The hydraulic conductivity of sediments: A pore size perspective

    KAUST Repository

    Ren, X.W.

    2017-12-06

    This article presents an analysis of previously published hydraulic conductivity data for a wide range of sediments. All soils exhibit a prevalent power trend between the hydraulic conductivity and void ratio. Data trends span 12 orders of magnitude in hydraulic conductivity and collapse onto a single narrow trend when the hydraulic conductivity data are plotted versus the mean pore size, estimated using void ratio and specific surface area measurements. The sensitivity of hydraulic conductivity to changes in the void ratio is higher than the theoretical value due to two concurrent phenomena: 1) percolating large pores are responsible for most of the flow, and 2) the larger pores close first during compaction. The prediction of hydraulic conductivity based on macroscale index parameters in this and similar previous studies has reached an asymptote in the range of kmeas/5≤kpredict≤5kmeas. The remaining uncertainty underscores the important role of underlying sediment characteristics such as pore size distribution, shape, and connectivity that are not measured with index properties. Furthermore, the anisotropy in hydraulic conductivity cannot be recovered from scalar parameters such as index properties. Overall, results highlight the robustness of the physics inspired data scrutiny based Hagen–Poiseuille and Kozeny-Carman analyses.

  3. Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats

    Directory of Open Access Journals (Sweden)

    Lacerda J.E.C.

    2003-01-01

    Full Text Available The rostral ventrolateral medulla (RVLM contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv anesthetized Wistar rats (300-350 g. In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7. A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl. However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7 or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6 was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7 and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7 when lidocaine (34 nmol/200 nl was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

  4. Thermal conductivity in one-dimensional nonlinear systems

    Science.gov (United States)

    Politi, Antonio; Giardinà, Cristian; Livi, Roberto; Vassalli, Massimo

    2000-03-01

    Thermal conducitivity of one-dimensional nonlinear systems typically diverges in the thermodynamic limit, whenever the momentum is conserved (i.e. in the absence of interactions with an external substrate). Evidence comes from detailed studies of Fermi-Pasta-Ulam and diatomic Toda chains. Here, we discuss the first example of a one-dimensional system obeying Fourier law : a chain of coupled rotators. Numerical estimates of the thermal conductivity obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of the rotator model.

  5. Westinghouse GOCO conduct of casualty drills

    International Nuclear Information System (INIS)

    Ames, C.P.

    1996-02-01

    Purpose of this document is to provide Westinghouse Government Owned Contractor Operated (GOCO) Facilities with information that can be used to implement or improve drill programs. Elements of this guide are highly recommended for use when implementing a new drill program or when assessing an existing program. Casualty drills focus on response to abnormal conditions presenting a hazard to personnel, environment, or equipment; they are distinct from Emergency Response Exercises in which the training emphasis is on site, field office, and emergency management team interaction. The DOE documents which require team training and conducting drills in nuclear facilities and should be used as guidance in non-nuclear facilities are: DOE 5480.19 (Chapter 1 of Attachment I) and DOE 5480.20 (Chapter 1, paragraphs 7 a. and d. of continuing training). Casualty drills should be an integral part of the qualification and training program at every DOE facility

  6. Standards of conduct for NASA employees

    Science.gov (United States)

    1987-01-01

    'Standards of Conduct' for employees (14 CFR Part 1207) is set forth in this handbook and is hereby incorporated in the NASA Directives System. This handbook incorporates, for the convenience of NASA employees, the regulations now in effect prescribing standards of conduct for NASA employees. These regulations set forth the high ethical standards of conduct required of NASA employees in carrying out their duties and responsibilities. These regulations have been approved by the Office of Government Ethics, Office of Personnel Management. The regulations incorporated in this handbook were first published in the Federal Register on October 21, 1967 (32 FR 14648-14659); Part B concerning the acceptance of gifts, gratuities, or entertainment was extensively revised on January 19, 1976 (41 FR 2631-2633) to clarify and generally to restrict the exceptions to the general rule against the acceptance by a NASA employee from persons or firms doing or seeking business with NASA. Those regulations were updated on January 29, 1985 (50 FR 3887) to ensure conformity to the Ethics in Government Act of 1978 regarding the public financial disclosure statement. These regulations were published in the Federal Register on June 16, 1987 (52 FR 22755-764) and a correction was printed on Sept. 28, 1987 (52 FR 36234).

  7. Noninvasive Evaluation of Nerve Conduction in Small Diameter Fibers in the Rat

    OpenAIRE

    Elena G. Zotova; Joseph C. Arezzo

    2013-01-01

    A novel noninvasive technique was applied to measure velocity within slow conducting axons in the distal extreme of the sciatic nerve (i.e., digital nerve) in a rat model. The technique is based on the extraction of rectified multiple unit activity (MUA) from in vivo whole nerve compound responses. This method reliably identifies compound action potentials in thinly myelinated fibers conducting at a range of 9–18 m/s ( axons), as well as in a subgroup of unmyelinated C fibers conducting at ap...

  8. The NMC code: conduct, performance and ethics.

    Science.gov (United States)

    Goldsmith, Jan

    The Code: Standards of Conduct, Performance and Ethics for Nurses and Midwives is a set of key principles that should underpin the practice of all nurses and midwives, and remind them of their professional responsibilities. It is not just a tool used in fitness-to-practise cases--it should be used to guide daily practice for all nurses and midwives. Alongside other standards, guidance and advice from the NMC, the code should be used to support professional development.

  9. Perceived Parent-Child Relations, Conduct Problems, and Clinical Improvement Following the Treatment of Oppositional Defiant Disorder.

    Science.gov (United States)

    Booker, Jordan A; Ollendick, Thomas H; Dunsmore, Julie C; Greene, Ross W

    2016-05-01

    Our objective in this study was to examine the moderating influence of parent-child relationship quality (as viewed by the child) on associations between conduct problems and treatment responses for children with oppositional defiant disorder (ODD). To date, few studies have considered children's perceptions of relationship quality with parents in clinical contexts even though extant studies show the importance of this factor in children's behavioral adjustment in non-clinical settings. In this study, 123 children (ages 7 - 14 years, 61.8% male, 83.7% white) who fulfilled DSM-IV criteria for ODD received one of two psychosocial treatments: Parent Management Training or Collaborative & Proactive Solutions. In an earlier study, both treatments were found to be effective and equivalent in treatment outcomes (Ollendick et al., in press). In the current study, pre-treatment maternal reports of conduct problems and pre-treatment child reports of relations with parents were used to predict outcomes in ODD symptoms and their severity following treatment. Elevated reports of children's conduct problems were associated with attenuated reductions in both ODD symptoms and their severity. Perceived relationship quality with parents moderated the ties between conduct problems and outcomes in ODD severity but not the number of symptoms. Mother reports of elevated conduct problems predicted attenuated treatment response only when children viewed relationship quality with their parents as poorer. When children viewed the relationship as higher quality, they did not show an attenuated treatment response, regardless of reported conduct problems. The current findings underscore the importance of children's perspectives in treatment response and reductions in externalizing child behaviors.

  10. Extremely Low Birth Weight Preterm Infants Lack Vasomotor Response in Relationship to Cold Body Temperatures at Birth

    OpenAIRE

    Knobel, Robin B.; Holditch-Davis, Diane; Schwartz, Todd A.; Wimmer, John E.

    2009-01-01

    Objective This study evaluated peripheral vasoconstriction in ELBW infants when body temperature decreased during the first 12-hours of life. Design An exploratory, within-subjects design with 10 ELBW infants. Abdominal and foot temperatures were measured every minute. Peripheral vasoconstriction (abdominal > peripheral temperature by 2? C) and abdominal-peripheral temperature difference were also evaluated. Results Abdominal and peripheral temperatures were significantly correlated within ea...

  11. Conductivity in insulators due to implantation of conducting species

    International Nuclear Information System (INIS)

    Prawer, S.; Kalish, R.

    1993-01-01

    Control of the surface conductivity of insulators can be accomplished by high dose ion implantation of conductive species. The use of C + as the implant species is particularly interesting because C can either form electrically insulating sp 3 bonds or electrically conducting sp 2 bonds. In the present work, fused quartz plates have been irradiated with 100 keV C + ions to doses up to 1 x 10 17 ions/cm 2 at room temperature and at 200 deg C. The ion beam induced conductivity was monitored in-situ and was found to increase by up to 8 orders to magnitude for the ion dose range studied. Xe implantations over a similar range did not induce any changes in the conductivity showing that the increase in conductivity is caused by the presence of the C in the fused quartz matrix and not by damage. The dependence of the conductivity on implantation temperature and on post implantation annealing sheds light on the clustering of the C implants. The temperature dependence of the conductivity for the highest doses employed (1 x 10 17 C + /cm 2 ) can be described very well by lnσ α T. This is considered to be a peculiar dependence which does not comply with any of the standard models for conduction. 9 refs., 1 tab., 6 figs

  12. Damage detection and conductivity evolution in carbon nanofiber epoxy via electrical impedance tomography

    International Nuclear Information System (INIS)

    Tallman, T N; Wang, K W; Gungor, S; Bakis, C E

    2014-01-01

    Utilizing electrically conductive nanocomposites for integrated self-sensing and health monitoring is a promising area of structural health monitoring (SHM) research wherein local changes in conductivity coincide with damage. In this research we conduct proof of concept investigations using electrical impedance tomography (EIT) for damage detection by identifying conductivity changes and by imaging conductivity evolution in a carbon nanofiber (CNF) filled epoxy composite. CNF/epoxy is examined because fibrous composites can be manufactured with a CNF/epoxy matrix thereby enabling the entire matrix to become self-sensing. We also study the mechanisms of conductivity evolution in CNF/epoxy through electrical impedance spectroscopy (EIS) testing. The results of these tests indicate that thermal expansion is responsible for conductivity evolution in a CNF/epoxy composite. (paper)

  13. Acrolein-mediated conduction loss is partially restored by K+ channel blockers

    Science.gov (United States)

    Yan, Rui; Page, Jessica C.

    2015-01-01

    Acrolein-mediated myelin damage is thought to be a critical mechanism leading to conduction failure following neurotrauma and neurodegenerative diseases. The exposure and activation of juxtaparanodal voltage-gated K+ channels due to myelin damage leads to conduction block, and K+ channel blockers have long been studied as a means for restoring axonal conduction in spinal cord injury (SCI) and multiple sclerosis (MS). In this study, we have found that 100 μM K+ channel blockers 4-aminopyridine-3-methanol (4-AP-3-MeOH), and to a lesser degree 4-aminopyridine (4-AP), can significantly restore compound action potential (CAP) conduction in spinal cord tissue following acrolein-mediated myelin damage using a well-established ex vivo SCI model. In addition, 4-AP-3-MeOH can effectively restore CAP conduction in acrolein-damaged axons with a range of concentrations from 0.1 to 100 μM. We have also shown that while both compounds at 100 μM showed no preference of small- and large-caliber axons when restoring CAP conduction, 4-AP-3-MeOH, unlike 4-AP, is able to augment CAP amplitude while causing little change in axonal responsiveness measured in refractory periods and response to repetitive stimuli. In a prior study, we show that 4-AP-3-MeOH was able to functionally rescue mechanically injured axons. In this investigation, we conclude that 4-AP-3-MeOH is an effective K+ channel blocker in restoring axonal conduction following both primary (physical) and secondary (chemical) insults. These findings also suggest that 4-AP-3-MeOH is a viable alternative of 4-AP for treating myelin damage and improving function following central nervous system trauma and neurodegenerative diseases. PMID:26581866

  14. The effect of ethnicity on the vascular responses to cold exposure of the extremities.

    Science.gov (United States)

    Maley, Matthew J; Eglin, Clare M; House, James R; Tipton, Michael J

    2014-11-01

    Cold injuries are more prevalent in individuals of African descent (AFD). Therefore, we investigated the effect of extremity cooling on skin blood flow (SkBF) and temperature (T sk) between ethnic groups. Thirty males [10 Caucasian (CAU), 10 Asian (ASN), 10 AFD] undertook three tests in 30 °C air whilst digit T sk and SkBF were measured: (i) vasomotor threshold (VT) test--arm immersed in 35 °C water progressively cooled to 10 °C and rewarmed to 35 °C to identify vasoconstriction and vasodilatation; (ii) cold-induced vasodilatation (CIVD) test--hand immersed in 8 °C water for 30 min followed by spontaneous warming; (iii) cold sensitivity (CS) test--foot immersed in 15 °C water for 2 min followed by spontaneous warming. Cold sensory thresholds of the forearm and finger were also assessed. In the VT test, vasoconstriction and vasodilatation occurred at a warmer finger T sk in AFD during cooling [21.2 (4.4) vs. 17.0 (3.1) °C, P = 0.034] and warming [22.0 (7.9) vs. 12.1 (4.1) °C, P = 0.002] compared with CAU. In the CIVD test, average SkBF during immersion was greater in CAU [42 (24) %] than ASN [25 (8) %, P = 0.036] and AFD [24 (13) %, P = 0.023]. Following immersion, SkBF was higher and rewarming faster in CAU [3.2 (0.4) °C min(-1)] compared with AFD [2.5 (0.7) °C min(-1), P = 0.037], but neither group differed from ASN [3.0 (0.6) °C min(-1)]. Responses to the CS test and cold sensory thresholds were similar between groups. AFD experienced a more intense protracted finger vasoconstriction than CAU during hand immersion, whilst ASN experienced an intermediate response. This greater sensitivity to cold may explain why AFD are more susceptible to cold injuries.

  15. Dip-pen nanopatterning of photosensitive conducting polymer using a monomer ink

    Science.gov (United States)

    Su, Ming; Aslam, Mohammed; Fu, Lei; Wu, Nianqiang; Dravid, Vinayak P.

    2004-05-01

    Controlled patterning of conducting polymers at a micro- or nanoscale is the first step towards the fabrication of miniaturized functional devices. Here, we introduce an approach for the nanopatterning of conducting polymers using an improved monomer "ink" in dip-pen nanolithography (DPN). The nominal monomer "ink" is converted, in situ, to its conducting solid-state polymeric form after patterned. Proof-of-concept experiments have been performed with acid-promoted polymerization of pyrrole in a less reactive environment (tetrahydrofuran). The ratios of reactants are optimized to give an appropriate rate to match the operation of DPN. A similar synthesis process for the same polymer in its bulk form shows a high conductance and crystalline structure. The miniaturized conducting polymer sensors with light detection ability are fabricated by DPN using the improved ink formula, and exhibit excellent response, recovery, and sensitivity parameters.

  16. Dip-pen nanopatterning of photosensitive conducting polymer using a monomer ink

    International Nuclear Information System (INIS)

    Su Ming; Aslam, Mohammed; Fu Lei; Wu Nianqiang; Dravid, Vinayak P.

    2004-01-01

    Controlled patterning of conducting polymers at a micro- or nanoscale is the first step towards the fabrication of miniaturized functional devices. Here, we introduce an approach for the nanopatterning of conducting polymers using an improved monomer 'ink' in dip-pen nanolithography (DPN). The nominal monomer 'ink' is converted, in situ, to its conducting solid-state polymeric form after patterned. Proof-of-concept experiments have been performed with acid-promoted polymerization of pyrrole in a less reactive environment (tetrahydrofuran). The ratios of reactants are optimized to give an appropriate rate to match the operation of DPN. A similar synthesis process for the same polymer in its bulk form shows a high conductance and crystalline structure. The miniaturized conducting polymer sensors with light detection ability are fabricated by DPN using the improved ink formula, and exhibit excellent response, recovery, and sensitivity parameters

  17. Do intensity ratings and skin conductance responses reliably discriminate between different stimulus intensities in experimentally induced pain?

    Science.gov (United States)

    Breimhorst, Markus; Sandrock, Stephan; Fechir, Marcel; Hausenblas, Nadine; Geber, Christian; Birklein, Frank

    2011-01-01

    The present study addresses the question whether pain-intensity ratings and skin conductance responses (SCRs) are able to detect different intensities of phasic painful stimuli and to determine the reliability of this discrimination. For this purpose, 42 healthy participants of both genders were assigned to either electrical, mechanical, or laser heat-pain stimulation (each n = 14). A whole range of single brief painful stimuli were delivered on the right volar forearm of the dominant hand in a randomized order. Pain-intensity ratings and SCRs were analyzed. Using generalizability theory, individual and gender differences were the main contributors to the variability of both intensity ratings and SCRs. Most importantly, we showed that pain-intensity ratings are a reliable measure for the discrimination of different pain stimulus intensities in the applied modalities. The reliability of SCR was adequate when mechanical and heat stimuli were tested but failed for the discrimination of electrical stimuli. Further studies are needed to reveal the reason for this lack of accuracy for SCRs when applying electrical pain stimuli. Our study could help researchers to better understand the relationship between pain and activation of the sympathetic nervous system. Pain researchers are furthermore encouraged to consider individual and gender differences when measuring pain intensity and the concomitant SCRs in experimental settings. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  18. Conducting Polymers

    Indian Academy of Sciences (India)

    would exhibit electronic conductivity, their conductivities (of compressed pellets) were indeed measured by others, and were found to be .... Polyaniline. Polyphenylene. Polypheny lene- vinylene. Table 1. G!NeRAl I ARTICl! structure. Maximum conductivity Stem Stability. Processability. ~. 1.5 x 105. Reacts with Film not n air.

  19. Clinical features and pathophysiology of Complex Regional Pain Syndrome – current state of the art

    Science.gov (United States)

    Marinus, Johan; Moseley, G. Lorimer; Birklein, Frank; Baron, Ralf; Maihöfner, Christian; Kingery, Wade S.; van Hilten, Jacobus J.

    2017-01-01

    That a minor injury can trigger a complex regional pain syndrome (CRPS) - multiple system dysfunction, severe and often chronic pain and disability - has fascinated scientists and perplexed clinicians for decades. However, substantial advances across several medical disciplines have recently increased our understanding of CRPS. Compelling evidence implicates biological pathways that underlie aberrant inflammation, vasomotor dysfunction, and maladaptive neuroplasticity in the clinical features of CRPS. Collectively, the evidence points to CRPS being a multifactorial disorder that is associated with an aberrant host response to tissue injury. Varying susceptibility to perturbed regulation of any of the underlying biological pathways probably accounts for the clinical heterogeneity of CRPS. PMID:21683929

  20. Phentolamine tests and catecholamine levels in normotensive CVA patients.

    Science.gov (United States)

    Favazza, A R

    1974-11-01

    Ten normotensive patients diagnosed as having a CVA had Regitine tests and urinary VMA and catecholamine determinations during the first day of hospitalization. The VMA and catecholamine levels were all within normal limits (except for one elevated VMA level) but did not correlate well with each other. The average response to phentolamine was an average drop in blood pressure of 30mm. Hg systolic and 19 mm. Hg diastolic. Mechanisms by which hypertensive states or cerebral damage might effect blood pressure are discussed. It is suggested that CNS damage might induce a vasolabile or hypersensitive state via connections and consequent alterations in the autonomic vasomotor system.

  1. Conductive Elastomers for Stretchable Electronics, Sensors and Energy Harvesters

    Directory of Open Access Journals (Sweden)

    Jin-Seo Noh

    2016-04-01

    Full Text Available There have been a wide variety of efforts to develop conductive elastomers that satisfy both mechanical stretchability and electrical conductivity, as a response to growing demands on stretchable and wearable devices. This article reviews the important progress in conductive elastomers made in three application fields of stretchable technology: stretchable electronics, stretchable sensors, and stretchable energy harvesters. Diverse combinations of insulating elastomers and non-stretchable conductive materials have been studied to realize optimal conductive elastomers. It is noted that similar material combinations and similar structures have often been employed in different fields of application. In terms of stretchability, cyclic operation, and overall performance, fields such as stretchable conductors and stretchable strain/pressure sensors have achieved great advancement, whereas other fields like stretchable memories and stretchable thermoelectric energy harvesting are in their infancy. It is worth mentioning that there are still obstacles to overcome for the further progress of stretchable technology in the respective fields, which include the simplification of material combination and device structure, securement of reproducibility and reliability, and the establishment of easy fabrication techniques. Through this review article, both the progress and obstacles associated with the respective stretchable technologies will be understood more clearly.

  2. Atomistic simulations of highly conductive molecular transport junctions under realistic conditions

    KAUST Repository

    French, William R.; Iacovella, Christopher R.; Rungger, Ivan; Souza, Amaury Melo; Sanvito, Stefano; Cummings, Peter T.

    2013-01-01

    We report state-of-the-art atomistic simulations combined with high-fidelity conductance calculations to probe structure-conductance relationships in Au-benzenedithiolate (BDT)-Au junctions under elongation. Our results demonstrate that large increases in conductance are associated with the formation of monatomic chains (MACs) of Au atoms directly connected to BDT. An analysis of the electronic structure of the simulated junctions reveals that enhancement in the s-like states in Au MACs causes the increases in conductance. Other structures also result in increased conductance but are too short-lived to be detected in experiment, while MACs remain stable for long simulation times. Examinations of thermally evolved junctions with and without MACs show negligible overlap between conductance histograms, indicating that the increase in conductance is related to this unique structural change and not thermal fluctuation. These results, which provide an excellent explanation for a recently observed anomalous experimental result [Bruot et al., Nat. Nanotechnol., 2012, 7, 35-40], should aid in the development of mechanically responsive molecular electronic devices. © 2013 The Royal Society of Chemistry.

  3. Perceived Parent–Child Relations, Conduct Problems, and Clinical Improvement Following the Treatment of Oppositional Defiant Disorder

    Science.gov (United States)

    Booker, Jordan A.; Ollendick, Thomas H.; Dunsmore, Julie C.; Greene, Ross W.

    2015-01-01

    Our objective in this study was to examine the moderating influence of parent-child relationship quality (as viewed by the child) on associations between conduct problems and treatment responses for children with oppositional defiant disorder (ODD). To date, few studies have considered children’s perceptions of relationship quality with parents in clinical contexts even though extant studies show the importance of this factor in children’s behavioral adjustment in non-clinical settings. In this study, 123 children (ages 7 – 14 years, 61.8% male, 83.7% white) who fulfilled DSM-IV criteria for ODD received one of two psychosocial treatments: Parent Management Training or Collaborative & Proactive Solutions. In an earlier study, both treatments were found to be effective and equivalent in treatment outcomes (Ollendick et al., in press). In the current study, pre-treatment maternal reports of conduct problems and pre-treatment child reports of relations with parents were used to predict outcomes in ODD symptoms and their severity following treatment. Elevated reports of children’s conduct problems were associated with attenuated reductions in both ODD symptoms and their severity. Perceived relationship quality with parents moderated the ties between conduct problems and outcomes in ODD severity but not the number of symptoms. Mother reports of elevated conduct problems predicted attenuated treatment response only when children viewed relationship quality with their parents as poorer. When children viewed the relationship as higher quality, they did not show an attenuated treatment response, regardless of reported conduct problems. The current findings underscore the importance of children’s perspectives in treatment response and reductions in externalizing child behaviors. PMID:27284234

  4. A biomorphic origami actuator fabricated by folding a conducting paper

    International Nuclear Information System (INIS)

    Okuzaki, H; Saido, T; Suzuki, H; Hara, Y; Yan, H

    2008-01-01

    Cooperation between the electrical conductivity and hygroscopic nature of conducting polymers can provide an insight into the development of a new class of electro-active polymer (EAP) actuators or soft robots working in ambient air. In this paper, we describe an 'origami' actuator fabricated by folding a sheet of conducting 'paper'. The principle lies in the electrically induced changes in the elastic modulus of a humidosensitive conducting polymer film through reversible sorption and desorption of water vapor molecules, which is responsible for amplifying a contraction of the film (∼ 1%) to more than a 100-fold expansion (> 100%) of the origami actuator. Utilizing the origami technique, we have fabricated a biomorphic origami robot by folding an electrochemically synthesized polypyrrole film into the figure of an accordion shape, which can move with a caterpillar-like motion by repeated expansion and contraction at a velocity of 2 cm min -1 .

  5. Post-market clinical research conducted by medical device manufacturers: a cross-sectional survey.

    Science.gov (United States)

    Ross, Joseph S; Blount, Katrina L; Ritchie, Jessica D; Hodshon, Beth; Krumholz, Harlan M

    2015-01-01

    In the US, once a medical device is made available for use, several requirements have been established by the US Food and Drug Administration (FDA) to ensure ongoing post-market surveillance of device safety and effectiveness. Our objective was to determine how commonly medical device manufacturers initiate post-market clinical studies or augment FDA post-market surveillance requirements for higher-risk devices that are most often approved via the FDA's pre-market approval (PMA) pathway. We conducted a cross-sectional survey of 47 manufacturers with operations in California, Minnesota, and Massachusetts who market devices approved via the PMA pathway. Among 22 respondents (response rate =47%), nearly all self-reported conducting post-market clinical research studies, commonly between 1 and 5; only 1 respondent reported never conducting post-market clinical research studies. While manufacturers most often engaged in these studies to satisfy FDA requirements, other reasons were reported, including performance monitoring and surveillance and market acceptance initiatives. Risks of conducting and not conducting post-market clinical research studies were described through open-ended response to questions. Medical device manufacturers commonly initiate post-market clinical studies at the request of the FDA. Clinical data from these studies should be integrated into national post-market surveillance initiatives.

  6. The sensory channel of presentation alters subjective ratings and autonomic responses towards disgusting stimuli -Blood pressure, heart rate and skin conductance in response to visual, auditory, haptic and olfactory presented disgusting stimuli-

    Directory of Open Access Journals (Sweden)

    Ilona eCroy

    2013-09-01

    Full Text Available Disgust causes specific reaction patterns, observable in mimic responses and body reactions. Most research on disgust deals with visual stimuli. However, pictures may cause another disgust experience than sounds, odors or tactile stimuli. Therefore disgust experience evoked by four different sensory channels was compared.A total of 119 participants received 3 different disgusting and one control stimulus, each presented through the visual, auditory, tactile and olfactory channel. Ratings of evoked disgust as well as responses of the autonomic nervous system (heart rate, skin conductance level, systolic blood pressure were recorded and the effect of stimulus labeling and of repeated presentation was analyzed. Ratings suggested that disgust could be evoked through all senses; they were highest for visual stimuli. However, autonomic reaction towards disgusting stimuli differed according to the channel of presentation. In contrast to the other, olfactory disgust stimuli provoked a strong decrease of systolic blood pressure. Additionally, labeling enhanced disgust ratings and autonomic reaction for olfactory and tactile, but not for visual and auditory stimuli. Repeated presentation indicated that participant’s disgust rating diminishes to all but olfactory disgust stimuli. Taken together we argue that the sensory channel through which a disgust reaction is evoked matters.

  7. Predictors and Frequency of Conduction Disturbances After Open-Heart Surgery

    Directory of Open Access Journals (Sweden)

    Zahra Emkanjoo

    2008-02-01

    Full Text Available Introduction The risk of developing conduction disturbances after coronary bypass grafting (CABG or valvular surgery has been well established in previous studies, leading to permanent pacemaker implantation in about 2% to 3% of patients, and in 10% of patients undergoing repeat cardiac surgery.We sought to determine the incidence, features and predictors of conduction disorders in the immediate post-operative period of patients subjected to open-heart surgery, and the need for permanent pacemaker implantation.Material and Method We prospectively studied 374 consecutive patients who underwent open-heart surgery in our institution: coronary artery bypass (CABG (n=128, Mitral valve replacement(MVR(n=18, aortic valve replacement(AVR (n=21, MVR and AVR(n=56, repair of ventricular septal defect (VSD (n=51, repair of tetralogy of Fallot (TOF (n=57,CABG and valvular surgery (n=6, others (n=37.Results Among 374 patients included in our study (mean age 34.46±25.68; 146 males, 192 developed new conduction disorders: symptomatic sinus bradycardia in 8%, atrial fibrillation with slow ventricular response (AF in 4.5%, first-degree atrioventricular block (AVBin 6.4%, second-degree AVB in 0.3%, third-degree AVB in 7%, new right bundle branch block (RBBB in 33%, and new left bundle branch block (LBBB in 2.1%. In 5.6% patients, a permanent pacemaker was implanted, 47.6% of them underwent valvular surgery. In 44.1% of patients the conduction defects occurred in the first 48 hr. after surgery. In CABG group, 29.7% of patients developed new conduction disturbances; the most common of them was symptomatic sinus bradycardia. After valvular surgery 44.2% of patients developed conduction disturbances, of those the most common was atrial fibrillation with slow ventricular response . After VSD and TOF repair, the most common conduction disturbance was new RBBB. Perioperative myocardial infarction (MI occurred in 1.9% of patients. The occurrence conduction disturbance

  8. Electrical conductivity of pyroxene which contains trivalent cations: Laboratory measurements and the lunar temperature profile

    International Nuclear Information System (INIS)

    Huebner, J.S.; Duba, A.; Wiggins, L.B.

    1979-01-01

    Three natural orthopyroxene single crystals, measured in the laboratory over the temperature range 850 0 --1200 0 C, are more than 1/2 order of magnitude more electrically conducting than previously measured crystals. Small concentrations (1--2%) of Al 2 O 3 and Cr 2 O 3 present in these crystals may be responsible for their relatively high conductivity. Such pyroxenes, which contain trivalent elements, are more representative of pyroxenes expected to be present in the lunar mantle than those which have been measured by other investigators. The new conductivity values for pyroxene are responsible for a relatively large bulk conductivity calculated for (polymineralic) lunar mantle assemblages. The results permit a somewhat cooler lunar temperature profile than previously proposed. Such lower profiles, several hundred degrees Celsius below the solidus, are quite consistent with low seismic attenuation and deep moonquakes observed in the lunar mantle

  9. THE IMPACTS OF PHILANTHROPY RESPONSIBILITY AND ETHICAL RESPONSIBILITY TOWARD CUSTOMER PURCHASE BEHAVIOR AND CUSTOMER LOYALTY

    OpenAIRE

    Kurniawati Chrisjatmiko; Danthy Margareth

    2018-01-01

    The purpose of this research is to analyze the impact of philanthropy responsibility and ethical responsibility towards customer purchase behavior and customer loyalty on fast food restaurants. The research was conducted by using quantitative research design and hypothetical testing to explore philanthropic responsibility, ethical responsibility, customer purchase behavior, and customer loyalty variables. Samples were taken from 186 respondents of employee population in Jakarta. Structural eq...

  10. Morphological dependency of cutaneous blood flow and sweating during compensable heat stress when heat-loss requirements are matched across participants.

    Science.gov (United States)

    Notley, Sean R; Park, Joonhee; Tagami, Kyoko; Ohnishi, Norikazu; Taylor, Nigel A S

    2016-07-01

    Human heat loss is thought, in part, to be morphologically related. It was therefore hypothesized that when heat-loss requirements and body temperatures were matched, that the mass-specific surface area alone could significantly explain both cutaneous vascular and sudomotor responses during compensable exercise. These thermoeffector responses were examined in 36 men with widely varying mass-specific surface areas (range, 232.3-292.7 cm(2)/kg), but of similar age, aerobic fitness, and adiposity. Subjects completed two trials under compensable conditions (28.1°C, 36.8% relative humidity), each involving rest (20 min) and steady-state cycling (45 min) at two matched metabolic heat-production rates (light, ∼135 W/m(2); moderate, ∼200 W/m(2)). Following equivalent mean body temperature changes, forearm blood flow and vascular conductance (r = 0.63 and r = 0.65) shared significant, positive associations with the mass-specific surface area during light work (P < 0.05), explaining ∼45% of the vasomotor variation. Conversely, during light and moderate work, whole body sweat rate, as well as local sweat rate and sudomotor sensitivity at three of four measured sites, revealed moderate, negative relationships with the mass-specific surface area (correlation coefficient range -0.37 to -0.73, P < 0.05). Moreover, those relationships could uniquely account for between 10 and 53% of those sweating responses (P < 0.05). Therefore, both thermoeffector responses displayed a significant morphological dependency in the presence of equivalent thermoafferent drive. Indeed, up to half of the interindividual variation in these effector responses could now be explained through morphological differences and the first principles governing heat transfer. Copyright © 2016 the American Physiological Society.

  11. AC-conductance and capacitance measurements for ethanol vapor detection using carbon nanotube-polyvinyl alcohol composite based devices.

    Science.gov (United States)

    Greenshields, Márcia W C C; Meruvia, Michelle S; Hümmelgen, Ivo A; Coville, Neil J; Mhlanga, Sabelo D; Ceragioli, Helder J; Quispe, Jose C Rojas; Baranauskas, Vitor

    2011-03-01

    We report the preparation of inexpensive ethanol sensor devices using multiwalled carbon nanotube-polyvinyl alcohol composite films deposited onto interdigitated electrodes patterned on phenolite substrates. We investigate the frequency dependent response of the device conductance and capacitance showing that higher sensitivity is obtained at higher frequency if the conductance is used as sensing parameter. In the case of capacitance measurements, higher sensitivity is obtained at low frequency. Ethanol detection at a concentration of 300 ppm in air is demonstrated. More than 80% of the sensor conductance and capacitance variation response occurs in less than 20 s.

  12. A state-space modeling approach to estimating canopy conductance and associated uncertainties from sap flux density data.

    Science.gov (United States)

    Bell, David M; Ward, Eric J; Oishi, A Christopher; Oren, Ram; Flikkema, Paul G; Clark, James S

    2015-07-01

    Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as canopy conductance and transpiration. To address this need, we developed a hierarchical Bayesian State-Space Canopy Conductance (StaCC) model linking canopy conductance and transpiration to tree sap flux density from a 4-year experiment in the North Carolina Piedmont, USA. Our model builds on existing ecophysiological knowledge, but explicitly incorporates uncertainty in canopy conductance, internal tree hydraulics and observation error to improve estimation of canopy conductance responses to atmospheric drought (i.e., vapor pressure deficit), soil drought (i.e., soil moisture) and above canopy light. Our statistical framework not only predicted sap flux observations well, but it also allowed us to simultaneously gap-fill missing data as we made inference on canopy processes, marking a substantial advance over traditional methods. The predicted and observed sap flux data were highly correlated (mean sensor-level Pearson correlation coefficient = 0.88). Variations in canopy conductance and transpiration associated with environmental variation across days to years were many times greater than the variation associated with model uncertainties. Because some variables, such as vapor pressure deficit and soil moisture, were correlated at the scale of days to weeks, canopy conductance responses to individual environmental variables were difficult to interpret in isolation. Still, our results highlight the importance of accounting for uncertainty in models of ecophysiological and ecosystem function where the process of interest, canopy conductance in this case, is not observed directly. The StaCC modeling

  13. Cross cultural adaptation of the menopause specific questionnaire ...

    African Journals Online (AJOL)

    Cross cultural adaptation of the menopause specific questionnaire into the Persian language. ... Annals of Medical and Health Sciences Research ... good internal consistency in vasomotor, physical and psychosocial domains, but not sexual.

  14. Quantum theory of terahertz conductivity of semiconductor nanostructures

    Czech Academy of Sciences Publication Activity Database

    Ostatnický, T.; Pushkarev, Vladimir; Němec, Hynek; Kužel, Petr

    2018-01-01

    Roč. 97, č. 8 (2018), s. 1-8, č. článku 085426. ISSN 2469-9950 R&D Projects: GA ČR GA17-03662S EU Projects: European Commission(XE) 607521 - NOTEDEV Institutional support: RVO:68378271 Keywords : nanostructures * nanoparticles * terahertz conductivity * quantum theory * linear response Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

  15. NON-INVASIVE EVALUATION OF NERVE CONDUCTION IN SMALL DIAMETER FIBERS IN THE RAT

    OpenAIRE

    Zotova, Elena G.; Arezzo, Joseph C.

    2013-01-01

    A novel non-invasive technique was applied to measure velocity within slow conducting axons in the distal extreme of the sciatic nerve (i.e., digital nerve) in a rat model. The technique is based on the extraction of rectified multiple unit activity (MUA) from in vivo whole nerve compound responses. This method reliably identifies compound action potentials in thinly myelinated fibers conducting at a range of 9-18 m/s (Aδ axons), as well as in a subgroup of unmylinated C fibers conducting at ...

  16. Tritium conductivity and isotope effect in proton-conducting perovskites

    International Nuclear Information System (INIS)

    Mukundan, R.; Brosha, E.L.; Birdsell, S.A.; Costello, A.L.; Garzon, F.H.; Willms, R.S.

    1999-01-01

    The tritium ion conductivities of SrZr 0.9 Yb 0.1 O 2.95 and BaCe 0.9 Yb 0.1 O 2.95 have been measured by ac impedance analysis. The high tritium conductivity of these perovskites could potentially lead to their application as an electrochemical membrane for the recovery of tritium from tritiated gas streams. The conductivities of these perovskites, along with SrCe 0.95 Yb 0.05 O 2.975 , were also measured in hydrogen- and deuterium-containing atmospheres to illustrate the isotope effect. For the strontium zirconate and barium cerate samples, the impedance plot consists of two clearly resolved arcs, a bulk and a grain boundary arc, in the temperature range 50--350 C. However, for the strontium cerate sample, the clear resolution of the bulk conductivity was not possible and only the total conductivity was measurable. Thus, the isotope effect was clearly established only for the strontium zirconate and barium cerate samples. The decrease in bulk conductivity with increasing isotope mass was found to be a result of an increase in the activation energy for conduction accompanied by a decrease in the pre-exponential factor. Since the concentration of the mobile species (H+, D+, or T+) should remain relatively constant at T < 350 C, this increase in activation energy is directly attributable to the increased activation energy for the isotope mobility

  17. Linkage between pain sensitivity and empathic response in adolescents with autism spectrum conditions and conduct disorder symptoms.

    Science.gov (United States)

    Chen, Chenyi; Hung, An-Yi; Fan, Yang-Teng; Tan, Shuai; Hong, Hua; Cheng, Yawei

    2017-02-01

    Lack of empathy is one of the behavioral hallmarks in individuals with autism spectrum conditions (ASC) as well as youth with conduct disorder symptoms (CDS). Previous research has reliably documented considerable overlap between the perception of others' pain and first-hand experience of pain. However, the linkage between empathy for pain and sensitivity to physical pain needs to be empirically determined, particularly in individuals with empathy deficits. This study measured the pressure pain threshold, which indexes sensitization of peripheral nociceptors, and assessed subjective ratings of unpleasantness and pain intensity in response to empathy-eliciting stimuli depicting physical bodily injuries in three age- and sex-matched participant groups: ASC, CDS, and typically developing controls (TDC). The results indicated that the pain threshold was lowest in the ASC group and highest in the CDS group. The ASC group displayed lower ratings of unpleasantness and pain intensity than did the TDC and CDS groups. Within the ASC and CDS, pain intensity ratings were significantly correlated with unpleasantness ratings to others' pain. Moreover, the ASC significantly differed from the TDC in the correlation between pain threshold values and unpleasantness ratings. These findings may cast some light on the linkage between atypical low-level sensory functioning, for instance altered pain sensitivity, and high-level empathic processing. Autism Res 2017, 10: 267-275. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  18. A biomorphic origami actuator fabricated by folding a conducting paper

    Energy Technology Data Exchange (ETDEWEB)

    Okuzaki, H; Saido, T; Suzuki, H; Hara, Y; Yan, H [Laboratory of Organic Robotics, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, 400-8511 (Japan)], E-mail: okuzaki@yamanashi.ac.jp

    2008-08-15

    Cooperation between the electrical conductivity and hygroscopic nature of conducting polymers can provide an insight into the development of a new class of electro-active polymer (EAP) actuators or soft robots working in ambient air. In this paper, we describe an 'origami' actuator fabricated by folding a sheet of conducting 'paper'. The principle lies in the electrically induced changes in the elastic modulus of a humidosensitive conducting polymer film through reversible sorption and desorption of water vapor molecules, which is responsible for amplifying a contraction of the film ({approx} 1%) to more than a 100-fold expansion (> 100%) of the origami actuator. Utilizing the origami technique, we have fabricated a biomorphic origami robot by folding an electrochemically synthesized polypyrrole film into the figure of an accordion shape, which can move with a caterpillar-like motion by repeated expansion and contraction at a velocity of 2 cm min{sup -1}.

  19. Calibration of non-ideal thermal conductivity sensors

    Directory of Open Access Journals (Sweden)

    N. I. Kömle

    2013-04-01

    Full Text Available A popular method for measuring the thermal conductivity of solid materials is the transient hot needle method. It allows the thermal conductivity of a solid or granular material to be evaluated simply by combining a temperature measurement with a well-defined electrical current flowing through a resistance wire enclosed in a long and thin needle. Standard laboratory sensors that are typically used in laboratory work consist of very thin steel needles with a large length-to-diameter ratio. This type of needle is convenient since it is mathematically easy to derive the thermal conductivity of a soft granular material from a simple temperature measurement. However, such a geometry often results in a mechanically weak sensor, which can bend or fail when inserted into a material that is harder than expected. For deploying such a sensor on a planetary surface, with often unknown soil properties, it is necessary to construct more rugged sensors. These requirements can lead to a design which differs substantially from the ideal geometry, and additional care must be taken in the calibration and data analysis. In this paper we present the performance of a prototype thermal conductivity sensor designed for planetary missions. The thermal conductivity of a suite of solid and granular materials was measured both by a standard needle sensor and by several customized sensors with non-ideal geometry. We thus obtained a calibration curve for the non-ideal sensors. The theory describing the temperature response of a sensor with such unfavorable length-to-diameter ratio is complicated and highly nonlinear. However, our measurements reveal that over a wide range of thermal conductivities there is an almost linear relationship between the result obtained by the standard sensor and the result derived from the customized, non-ideal sensors. This allows for the measurement of thermal conductivity values for harder soils, which are not easily accessible when using

  20. Fabrication of Biosensors Based on Nanostructured Conducting Polyaniline (NSPANI

    Directory of Open Access Journals (Sweden)

    Deepshikha SAINI

    2011-11-01

    Full Text Available In this study, glucose and hydrogen peroxide (H2O2 biosensors based on nanostructured conducting polyaniline (NSPANI (synthesized using sodiumdodecyl sulphate (SDS as structure directing agent were developed. Because of the large specific surface area, excellent conductivity of NSPANI, horseradish peroxidase (HRP and glucose oxidase (GOx could be easily immobilized with high loading and activity. In addition the small dimensions and the high surface-to-volume ratio of the NSCP allow the rapid transmission of electron and enhance current response. The linear dynamic range of optical glucose and H2O2 biosensors is 5–40 mM for glucose and 1–50 mM for H2O2, respectively where as the bulk PANI exhibits linearity between 5-20 mM/l. The miniature optical glucose biosensor also exhibits good reproducibility. The storage stability of optical glucose and H2O2 biosensors is two weeks for glucose and five days for H2O2. The high response value of NSPANI based biosensors as compared to bulk PANI based biosensor reflects higher enzymatic affinity of GOx/NSPANI and HRP/NSPANI with glucose and H2O2 due to biocompatibility, active surface area and high electron communication capability of nanobiopolymer film. In conclusion, the NSPANI based biosensors proposed herein have many advantages such as a low response time, high reproducibility, high sensitivity, stable and wide dynamic range.

  1. Heart rate and skin conductance responses to taste, taste novelty, and the (dis)confirmation of expectations

    NARCIS (Netherlands)

    Verastegui-Tena, Luz; Trijp, van Hans; Piqueras-Fiszman, Betina

    2018-01-01

    It is unclear whether the responses of the autonomic nervous system (ANS) can measure how people respond to food. Results focused on emotional responses are contradictory; therefore, the focus has shifted to other components of emotion, such as appraisals. The aim of this study was, therefore, to

  2. Electric Response and Conductivity Mechanism in H3PO4‑Doped Polybenzimidazole-4N−HfO2 Nanocomposite Membranes for High Temperature Fuel Cells

    International Nuclear Information System (INIS)

    Nawn, Graeme; Vezzù, Keti; Bertasi, Federico; Pagot, Gioele; Pace, Giuseppe; Conti, Fosca; Negro, Enrico

    2017-01-01

    Relaxation and polarization phenomena of phosphoric acid-doped [PBI4N(HfO 2 ) x ](H 3 PO 4 ) y nanocomposite membranes for high-temperature proton-exchange membrane fuel cells are studied using Dynamic Mechanical Analysis (DMA) and Broadband Electrical Spectroscopy (BES). The membranes are obtained by casting combinations of a polybenzimidazole polymer (PBI4N) with increasing amounts of hafnium oxide nanofiller, resulting in [PBI4N(HfO 2 ) x ] hybrid systems with 0 ≤ x ≤ 0.32. Phosphoric acid at varying content levels (0 ÷ 18 wt%) is used as a doping agent, giving rise to [PBI4N(HfO 2 ) x ](H 3 PO 4 ) y membranes. DMA and BES studies lead us to determine that the electric response of the membranes is modulated by polarization phenomena and by α and β dielectric relaxation events of the polymer matrix. Additionally, the experimental results suggest that in [PBI4N(HfO 2 ) x ](H 3 PO 4 ) y membranes the conductivity occurs owing to three conductivity pathways: two mechanisms involving inter-domain proton migration phenomena by “hopping” events; and one mechanism in which proton exchange occurs between delocalization bodies. These results highlight the significant effect of the hafnium oxide nanofiller content on the conductivity of [PBI4N(HfO 2 ) x ](H 3 PO 4 ) y where, at x ≥ 0.04, demonstrates conductivity higher (9.0 × 10 −2 S/cm) than that of pristine H 3 PO 4 -doped PBI4N (4.8 × 10 −2 S/cm) at T ≥ 155 °C.

  3. Dynamic conductivity modified by impurity resonant states in doping three-dimensional Dirac semimetals

    Science.gov (United States)

    Li, Shuai; Wang, Chen; Zheng, Shi-Han; Wang, Rui-Qiang; Li, Jun; Yang, Mou

    2018-04-01

    The impurity effect is studied in three-dimensional Dirac semimetals in the framework of a T-matrix method to consider the multiple scattering events of Dirac electrons off impurities. It has been found that a strong impurity potential can significantly restructure the energy dispersion and the density of states of Dirac electrons. An impurity-induced resonant state emerges and significantly modifies the pristine optical response. It is shown that the impurity state disturbs the common longitudinal optical conductivity by creating either an optical conductivity peak or double absorption jumps, depending on the relative position of the impurity band and the Fermi level. More importantly, these conductivity features appear in the forbidden region between the Drude and interband transition, completely or partially filling the Pauli block region of optical response. The underlying physics is that the appearance of resonance states as well as the broadening of the bands leads to a more complicated selection rule for the optical transitions, making it possible to excite new electron-hole pairs in the forbidden region. These features in optical conductivity provide valuable information to understand the impurity behaviors in 3D Dirac materials.

  4. Calibration-free electrical conductivity measurements for highly conductive slags

    International Nuclear Information System (INIS)

    Macdonald, Christopher J.; Gao, Huang; Pal, Uday B.; Van den Avyle, James A.; Melgaard, David K.

    2000-01-01

    This research involves the measurement of the electrical conductivity (K) for the ESR (electroslag remelting) slag (60 wt.% CaF 2 - 20 wt.% CaO - 20 wt.% Al 2 O 3 ) used in the decontamination of radioactive stainless steel. The electrical conductivity is measured with an improved high-accuracy-height-differential technique that requires no calibration. This method consists of making continuous AC impedance measurements over several successive depth increments of the coaxial cylindrical electrodes in the ESR slag. The electrical conductivity is then calculated from the slope of the plot of inverse impedance versus the depth of the electrodes in the slag. The improvements on the existing technique include an increased electrochemical cell geometry and the capability of measuring high precision depth increments and the associated impedances. These improvements allow this technique to be used for measuring the electrical conductivity of highly conductive slags such as the ESR slag. The volatilization rate and the volatile species of the ESR slag measured through thermogravimetric (TG) and mass spectroscopy analysis, respectively, reveal that the ESR slag composition essentially remains the same throughout the electrical conductivity experiments

  5. Integration of conducting polymer network in non-conductive polymer substrates

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; West, Keld; Hassager, Ole

    2006-01-01

    Anew method for integration ofconjugated, inherently conducting polymers into non-conductive polymer substrates has been developed. Alayer of the conducting polymer is polymerised by chemical oxidation, e.g. using Fe(ID) p-toluene sulfonate (ferri tosylate) followed by washing with a solvent which...... simultaneously removes residual and spent oxidant and at the same time dissolves the top layer of the polymer substrate. This results in an integration of the conducting polymer into the surface layers of the polymer substrate. Several combinations of conducting polymers and substrates have been tested...... absorption during sequential reactive ion etching has allowed for analysis of the PEDOT distribution within the surface layer of thePMMA substrate. The surface resistance ofthe conducting polymer layer remains low while the surface layer at the same time adapts some of the mechanical properties...

  6. Myeloperoxidase deficiency preserves vasomotor function in humans

    Czech Academy of Sciences Publication Activity Database

    Rudolph, T.K.; Wipper, S.; Reiter, B.; Rudolph, V.; Coym, A.; Detter, Ch.; Lau, D.; Klinke, A.; Friedrichs, K.; Rau, T.; Pekarová, Michaela; Russ, D.; Knöll, K.; Kolk, M.; Schroeder, B.; Wegscheider, K.; Andresen, H.; Schwedhelm, E.; Boeger, R.; Ehmke, H.; Baldus, S.

    2012-01-01

    Roč. 33, č. 13 (2012), s. 1625-1634 ISSN 0195-668X Institutional research plan: CEZ:AV0Z50040702 Keywords : leucocyte * endothelium * vascular tone Subject RIV: BO - Biophysics Impact factor: 14.097, year: 2012

  7. Reversible sympathetic vasomotor dysfunction in POTS patients.

    Science.gov (United States)

    Freitas, J; Santos, R; Azevedo, E; Costa, O; Carvalho, M; de Freitas, A F

    2000-11-01

    Orthostatic intolerance refers to the development upon assuming an upright posture of disabling symptoms, which are partly relieved by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations due to excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurological and psychiatric evaluation, which usually fails to identify a specific abnormality. We investigated the autonomic and hemodynamic profile of POTS patients and the efficacy of bisoprolol and or fludrocortisone. We evaluated eleven female patients with POTS before and after medical treatment with a cardio-selective beta blocker (bisoprolol) and/or fludrocortisone, and eleven age-matched controls. Variability of heart rate and systolic blood pressure was assessed by Fast Fourier Transform, and spontaneous baroreceptor gain by temporal sequences slope and alpha index. Modelflow was used to quantify hemodynamics. All patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol and/or fludrocortisone. These results need further confirmation in a controlled double-blind study. Proper medical treatment dramatically improves the clinical and autonomic/hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is due to a hyperadrenergic activation and/or hypovolemia during orthostasis.

  8. Thermal conductivity model of vibro-packed fuel

    International Nuclear Information System (INIS)

    Yeon Soo, Kim

    2001-01-01

    In an effort to dispose of excess weapons grade plutonium accumulated in the cold war era in the United States and the Russian Federation, one method currently under investigation is the conversion of the plutonium into mixed oxide (MOX) reactor fuel for LWRs and fast reactors in the Russian Federation. A fuel option already partly developed at the Research Institute of Atomic Reactors (RIAR) in Dimitrovgrad is that of vibro-packed MOX. Fuel rod fabrication using powder vibro-packing is attractive because it includes neither a process too complex to operate in glove boxes (or remotely), nor a waste-producing step necessary for the conventional pellet rod fabrication. However, because of its loose bonding between fuel particles at the beginning of life, vibro-packed MOX fuel has a somewhat less effective thermal conductivity than fully sintered pellet fuel, and undergoes more restructuring. Helium would also likely be pressurized in vibro-packed MOX fuel rods for LWRs to enhance initial fuel thermal conductivity. The combination of these two factors complicates development of an accurate thermal conductivity model. But clearly in order to predict fuel thermomechanical responses during irradiation of vibro-packed MOX fuel, fuel thermal conductivity must be known. The Vibropac fuel of interest in this study refers the fuel that is compacted with irregular fragments of mixed oxide fuel. In this paper, the thermal-conductivity models in the literature that dealt with relatively similar situations to the present case are examined. Then, the best model is selected based on accuracy of prediction and applicability. Then, the selected model is expanded to fit the various situations of interest. (author)

  9. Advanced Testing Method for Ground Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

    2017-04-01

    A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

  10. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Namrata, E-mail: ntripat@ilstu.edu [Department of Physics, Illinois State University, Normal, IL 61790 (United States); Thakur, Awalendra K. [Department of Physics, Indian Institute of Technology Patna, Bihar 800013 (India); Shukla, Archana [Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology, Bombay 721302 (India); Marx, David T. [Department of Physics, Illinois State University, Normal, IL 61790 (United States)

    2015-07-15

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA{sub 4}LiClO{sub 4} dispersed with nano-CeO{sub 2} powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε′) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results.

  11. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    Science.gov (United States)

    Tripathi, Namrata; Thakur, Awalendra K.; Shukla, Archana; Marx, David T.

    2015-07-01

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA4LiClO4 dispersed with nano-CeO2 powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε‧) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results.

  12. Measures of skin conductance and heart rate in alcoholic men and women during memory performance

    Directory of Open Access Journals (Sweden)

    Kayle S. Sawyer

    2015-05-01

    Full Text Available We examined abnormalities in physiological responses to emotional stimuli associated with long-term chronic alcoholism. Skin conductance responses (SCR and heart rate (HR responses were measured in 32 abstinent alcoholic (ALC and 30 healthy nonalcoholic (NC men and women undergoing an emotional memory task in an MRI scanner. The task required participants to remember the identity of two emotionally-valenced faces presented at the onset of each trial during functional magnetic resonance imaging (fMRI scanning. After viewing the faces, participants saw a distractor image (an alcoholic beverage, nonalcoholic beverage, or scrambled image followed by a single probe face. The task was to decide whether the probe face matched one of the two encoded faces. Skin conductance measurements (before and after the encoded faces, distractor, and probe were obtained from electrodes on the index and middle fingers on the left hand. HR measurements (beats per minute before and after the encoded faces, distractor, and probe were obtained by a pulse oximeter placed on the little finger on the left hand. We expected that, relative to NC participants, the ALC participants would show reduced SCR and HR responses to the face stimuli, and that we would identify greater reactivity to the alcoholic beverage stimuli than to the distractor stimuli unrelated to alcohol. While the beverage type did not differentiate the groups, the ALC group did have reduced skin conductance and HR responses to elements of the task, as compared to the NC group.

  13. Gradient Learning in Spiking Neural Networks by Dynamic Perturbation of Conductances

    International Nuclear Information System (INIS)

    Fiete, Ila R.; Seung, H. Sebastian

    2006-01-01

    We present a method of estimating the gradient of an objective function with respect to the synaptic weights of a spiking neural network. The method works by measuring the fluctuations in the objective function in response to dynamic perturbation of the membrane conductances of the neurons. It is compatible with recurrent networks of conductance-based model neurons with dynamic synapses. The method can be interpreted as a biologically plausible synaptic learning rule, if the dynamic perturbations are generated by a special class of 'empiric' synapses driven by random spike trains from an external source

  14. The PP ampersand L Nuclear Department model for conducting self-assessments

    International Nuclear Information System (INIS)

    Murthy, M.L.R.; Vernick, H.R.; Male, A.M.; Burchill, W.E.

    1995-01-01

    The nuclear department of Pennsylvania Power ampersand Light Company (PP ampersand L) has initiated an aggressive, methodical, self-assessment program. Self-assessments are conducted to prevent problems, improve performance, and monitor results. The assessment activities are conducted by, or for, an individual having responsibility for performing the work being assessed. This individual, or customer, accepts ownership of the assessment effort and commits to implementing the recommendations agreed on during the assessment. This paper discusses the main elements of the assessment model developed by PP ampersand L and the results the model has achieved to date

  15. Conductivity of strongly pumped superconductors. An electron-phonon system far from equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Krull, Holger

    2015-01-29

    The study of nonequilibrium physics is of great interest, because one can capture novel phenomena and properties which are hidden at equilibrium, e.g., one can study relaxation processes. A common way to study the nonequilibrium dynamics of a sample is a pump-probe experiment. In a pump probe experiment an intense laser pulse, the so called pump pulse, excites the sample and takes it out of equilibrium. After a certain delay time a second pulse, the probe pulse, measures the actual state of the sample. In this thesis, we theoretically study the pump-probe response of superconductors. On the one hand we are interest in the effect of a pump pulse and on the other hand we want to provide the pump-probe response, such that experimental measurement can be easily interpreted. In order to do this, we use the density matrix formalism to compute the pump-probe response of the system. In the density matrix formalism equations of motion are set up for expectation values of interest. In order to study the dynamics induced by a pump pulse, we compute the temporal evolution of the quasiparticle densities and the mean phonon amplitude. We find that the induced dynamics of the system depends on characteristics of the pump pulse. For short pulses, the system is pushed into the nonadiabatic regime. In this regime, the order parameter is lowered during the pump pulse and shows a 1/(√(t))-decaying oscillation afterwards. In addition, coherent phonons are generated, which is resonantly enhanced if the frequency of the order parameter oscillation is equal to the phonon frequency. For long pulses, the system is pushed into the adiabatic regime. In this regime, the order parameter is lowered during the pulse and remains almost constant afterwards. Further, there is almost no generation of coherent phonons. For the pump-probe response we compute the conductivity induced by the probe pulse. The conductivity is a typical observable in real pump-probe experiments. Hence, it is possible to

  16. Conductivity of strongly pumped superconductors. An electron-phonon system far from equilibrium

    International Nuclear Information System (INIS)

    Krull, Holger

    2015-01-01

    The study of nonequilibrium physics is of great interest, because one can capture novel phenomena and properties which are hidden at equilibrium, e.g., one can study relaxation processes. A common way to study the nonequilibrium dynamics of a sample is a pump-probe experiment. In a pump probe experiment an intense laser pulse, the so called pump pulse, excites the sample and takes it out of equilibrium. After a certain delay time a second pulse, the probe pulse, measures the actual state of the sample. In this thesis, we theoretically study the pump-probe response of superconductors. On the one hand we are interest in the effect of a pump pulse and on the other hand we want to provide the pump-probe response, such that experimental measurement can be easily interpreted. In order to do this, we use the density matrix formalism to compute the pump-probe response of the system. In the density matrix formalism equations of motion are set up for expectation values of interest. In order to study the dynamics induced by a pump pulse, we compute the temporal evolution of the quasiparticle densities and the mean phonon amplitude. We find that the induced dynamics of the system depends on characteristics of the pump pulse. For short pulses, the system is pushed into the nonadiabatic regime. In this regime, the order parameter is lowered during the pump pulse and shows a 1/(√(t))-decaying oscillation afterwards. In addition, coherent phonons are generated, which is resonantly enhanced if the frequency of the order parameter oscillation is equal to the phonon frequency. For long pulses, the system is pushed into the adiabatic regime. In this regime, the order parameter is lowered during the pulse and remains almost constant afterwards. Further, there is almost no generation of coherent phonons. For the pump-probe response we compute the conductivity induced by the probe pulse. The conductivity is a typical observable in real pump-probe experiments. Hence, it is possible to

  17. Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics.

    Science.gov (United States)

    Zhu, Huayang; Ricote, Sandrine; Coors, W Grover; Kee, Robert J

    2015-01-01

    A model-based interpretation of measured equilibrium conductivity and conductivity relaxation is developed to establish thermodynamic, transport, and kinetics parameters for multiple charged defect conducting (MCDC) ceramic materials. The present study focuses on 10% yttrium-doped barium zirconate (BZY10). In principle, using the Nernst-Einstein relationship, equilibrium conductivity measurements are sufficient to establish thermodynamic and transport properties. However, in practice it is difficult to establish unique sets of properties using equilibrium conductivity alone. Combining equilibrium and conductivity-relaxation measurements serves to significantly improve the quantitative fidelity of the derived material properties. The models are developed using a Nernst-Planck-Poisson (NPP) formulation, which enables the quantitative representation of conductivity relaxations caused by very large changes in oxygen partial pressure.

  18. Temperature-dependent of Nonlinear Optical Conductance of Graphene-based Systems in High-intensity Terahertz Field

    Institute of Scientific and Technical Information of China (English)

    Jing Lv; Rui-yang Yuan; Hui Yan

    2014-01-01

    For multi-photon processed with the linear dispersion in the high-intensity terahertz(THz) field,we have systematically investigated the temperature-dependent nonlinear optical response of graphene-based systems, including single layer graphene, graphene superlattice and gapped graphene. In the intrinsic single layer graphene system, it demonstrates that, at low temperature, nonlinear optical conductivities of the thirdand fifth-order are respectively five and ten orders of magnitude larger than the universal conductivity with high-intensity and low frequency THz wave.In the graphene superlattice and gapped graphene systems, the optical responses enhanced because of the anisotropic massless and massive Dirac fermions.

  19. Oxygen vacancies: The origin of n -type conductivity in ZnO

    Science.gov (United States)

    Liu, Lishu; Mei, Zengxia; Tang, Aihua; Azarov, Alexander; Kuznetsov, Andrej; Xue, Qi-Kun; Du, Xiaolong

    2016-06-01

    Oxygen vacancy (VO) is a common native point defect that plays crucial roles in determining the physical and chemical properties of metal oxides such as ZnO. However, fundamental understanding of VO is still very sparse. Specifically, whether VO is mainly responsible for the n -type conductivity in ZnO has been still unsettled in the past 50 years. Here, we report on a study of oxygen self-diffusion by conceiving and growing oxygen-isotope ZnO heterostructures with delicately controlled chemical potential and Fermi level. The diffusion process is found to be predominantly mediated by VO. We further demonstrate that, in contrast to the general belief of their neutral attribute, the oxygen vacancies in ZnO are actually +2 charged and thus responsible for the unintentional n -type conductivity as well as the nonstoichiometry of ZnO. The methodology can be extended to study oxygen-related point defects and their energetics in other technologically important oxide materials.

  20. Tunneling Conductivity and Piezoresistivity of Composites Containing Randomly Dispersed Conductive Nano-Platelets

    Science.gov (United States)

    Oskouyi, Amirhossein Biabangard; Sundararaj, Uttandaraman; Mertiny, Pierre

    2014-01-01

    In this study, a three-dimensional continuum percolation model was developed based on a Monte Carlo simulation approach to investigate the percolation behavior of an electrically insulating matrix reinforced with conductive nano-platelet fillers. The conductivity behavior of composites rendered conductive by randomly dispersed conductive platelets was modeled by developing a three-dimensional finite element resistor network. Parameters related to the percolation threshold and a power-low describing the conductivity behavior were determined. The piezoresistivity behavior of conductive composites was studied employing a reoriented resistor network emulating a conductive composite subjected to mechanical strain. The effects of the governing parameters, i.e., electron tunneling distance, conductive particle aspect ratio and size effects on conductivity behavior were examined. PMID:28788580

  1. Ischemic stroke: carotid and vertebral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Vilela, P.; Goulao, A. [Hospital Garcia de Orta, Servico de Neurorradiologia, Almada (Portugal)

    2005-03-01

    Ischemic strokes may have distinct aetiologies, including several different intrinsic arterial pathological disorders. The diagnosis and understanding of these arterial diseases is critical for the correct management of stroke as different treatment approaches are undertaken according to the aetiology. Atherosclerosis is by far the most common arterial disease among adults, and other pathological processes include arterial dissection, small vessel disease, inflammatory and non-inflammatory vasculopathy and vasomotor disorders. In children, there are several vasculopathies responsible for vaso-occlusive disease such as sickle-cell anemia, acute regressive angiopathy and Moya-Moya disease, neurofibromatosis, dissections, vasculitis associated with intracranial and systemic infections. An overview of the major carotid and vertebral pathological diseases responsible for ischemic stroke in adults and children, highlighting the accuracy of the different imaging modalities for its diagnosis and the imaging appearance of these diseases, is given. (orig.)

  2. Ischemic stroke: carotid and vertebral artery disease

    International Nuclear Information System (INIS)

    Vilela, P.; Goulao, A.

    2005-01-01

    Ischemic strokes may have distinct aetiologies, including several different intrinsic arterial pathological disorders. The diagnosis and understanding of these arterial diseases is critical for the correct management of stroke as different treatment approaches are undertaken according to the aetiology. Atherosclerosis is by far the most common arterial disease among adults, and other pathological processes include arterial dissection, small vessel disease, inflammatory and non-inflammatory vasculopathy and vasomotor disorders. In children, there are several vasculopathies responsible for vaso-occlusive disease such as sickle-cell anemia, acute regressive angiopathy and Moya-Moya disease, neurofibromatosis, dissections, vasculitis associated with intracranial and systemic infections. An overview of the major carotid and vertebral pathological diseases responsible for ischemic stroke in adults and children, highlighting the accuracy of the different imaging modalities for its diagnosis and the imaging appearance of these diseases, is given. (orig.)

  3. Heat conduction errors and time lag in cryogenic thermometer installations

    Science.gov (United States)

    Warshawsky, I.

    1973-01-01

    Installation practices are recommended that will increase rate of heat exchange between the thermometric sensing element and the cryogenic fluid and that will reduce the rate of undesired heat transfer to higher-temperature objects. Formulas and numerical data are given that help to estimate the magnitude of heat-conduction errors and of time lag in response.

  4. Spin and spinless conductivity in polypyrrole. Evidence for mixed-valence conduction

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G.; Schiavon, G. (Ist. di Polarografia ed Elettrochimica Preparativa, Padova (Italy))

    In situ conductivity of polypyrrole (as tosylate) as a function of oxidative doping level attains a maximum at three-quarters the total oxidation charge and the relevant in situ ESR signal corresponds to an equal concentration of spin-carrying (polaron) and spinless (bipolaron) species. Results are explained on the basis of mixed-valence conduction. Bipolaron conduction, taking the place of polaron-bipolaron conductivity at higher oxidation levels, accounts for persisting conductivity in the high-oxidation state.

  5. High-conductance states in a mean-field cortical network model

    CERN Document Server

    Lerchner, A; Hertz, J

    2004-01-01

    Measured responses from visual cortical neurons show that spike times tend to be correlated rather than exactly Poisson distributed. Fano factors vary and are usually greater than 1 due to the tendency of spikes being clustered into bursts. We show that this behavior emerges naturally in a balanced cortical network model with random connectivity and conductance-based synapses. We employ mean field theory with correctly colored noise to describe temporal correlations in the neuronal activity. Our results illuminate the connection between two independent experimental findings: high conductance states of cortical neurons in their natural environment, and variable non-Poissonian spike statistics with Fano factors greater than 1.

  6. An examination of the developmental propensity model of conduct problems.

    Science.gov (United States)

    Rhee, Soo Hyun; Friedman, Naomi P; Corley, Robin P; Hewitt, John K; Hink, Laura K; Johnson, Daniel P; Smith Watts, Ashley K; Young, Susan E; Robinson, JoAnn; Waldman, Irwin D; Zahn-Waxler, Carolyn

    2016-05-01

    The present study tested specific hypotheses advanced by the developmental propensity model of the etiology of conduct problems in the Colorado Longitudinal Twin Study, a prospective, longitudinal, genetically informative sample. High negative emotionality, low behavioral inhibition, low concern and high disregard for others, and low cognitive ability assessed during toddlerhood (age 14 to 36 months) were examined as predictors of conduct problems in later childhood and adolescence (age 4 to 17 years). Each hypothesized antisocial propensity dimension predicted conduct problems, but some predictions may be context specific or due to method covariance. The most robust predictors were observed disregard for others (i.e., responding to others' distress with active, negative responses such as anger and hostility), general cognitive ability, and language ability, which were associated with conduct problems reported by parents, teachers, and adolescents, and change in observed negative emotionality (i.e., frustration tolerance), which was associated with conduct problems reported by teachers and adolescents. Furthermore, associations between the most robust early predictors and later conduct problems were influenced by the shared environment rather than genes. We conclude that shared environmental influences that promote disregard for others and detract from cognitive and language development during toddlerhood also predispose individuals to conduct problems in later childhood and adolescence. The identification of those shared environmental influences common to early antisocial propensity and later conduct problems is an important future direction, and additional developmental behavior genetic studies examining the interaction between children's characteristics and socializing influences on conduct problems are needed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

    Included are discussions of rates of heat transfer by conduction, the effects of varying and changing properties, thermal explosions, distributed heat sources, moving heat sources, and non-steady three-dimensional conduction processes. Throughout, the importance of thinking both numerically and symbolically is stressed, as this is essential to the development of the intuitive understanding of numerical values needed for successful designing. Extensive tables of thermophysical properties, including thermal conductivity and diffusivity, are presented. Also included are exact and approximate solutions to many of the problems that arise in practical situations

  8. Preparation, Conduct and Evaluation of Exercises to Test Preparedness for a Nuclear or Radiological Emergency - Training Materials

    International Nuclear Information System (INIS)

    2010-01-01

    Emergency response exercises are a key component of a good program of preparation in emergencies. They can provide a unique insight on the State of preparation of emergency response organizations. They can also be the basis for continuous improvement programs of the infrastructure of response in emergencies. However, to be more useful, the exercises in emergency response need to be well organized, professionally conducted and its assessment should focus on the potential for constructive improvement. The course of the IAEA on preparedness, conduction and evaluation exercises to test the preparation before a nuclear emergency or radiation designed for people and organizations that want to increase their ability to carry out effective and significant emergency exercises. The objectives of this course are: To familiarize participants with concepts, terminology, process of preparation, conduction and evaluation of the exercise to test the preparation before a nuclear emergency or radiation; Provide participants with knowledge practical and the ability to organize, lead and evaluate an exercise to test the preparation for a nuclear emergency or radiation in their own countries; Submit an exercise response model in emergency prepared by the IAEA; and give participants the skill to adapt the proposal of model exercise and organize and lead this exercise model right in your own country. [es

  9. Characterizing the performance of an affordable, multichannel conductivity probe for density measurements in stratified flows

    Science.gov (United States)

    Subramanian, Balaji; Carminati, Marco; Luzzatto-Fegiz, Paolo

    2017-11-01

    In stratified flows, conductivity (combined with temperature) is often used to measure density. The conductivity probes typically used can resolve very fine spatial scales, but on the downside they are fragile, expensive, sensitive to environmental noise and have only single channel capability. Recently a low-cost, robust, arduino-based probe called Conduino was developed, which can be valuable in a wide range of applications where resolving extremely small spatial scales is not needed. This probe uses micro-USB connectors as actual conductivity sensors with a custom designed electronic board for simultaneous acquisition from multiple probes, with conductivity resolution comparable to commercially available PME conductivity probe. A detailed assessment of performance of this Conduino probe is described here. To establish time response and sensitivity as a function of electrode geometry, we build a variety of shapes for different kinds of applications, with tip spacing ranging from 0.5-2.5 mm, and with electrode length ranging from 2.3-6 mm. We set up a two-layer density profile and traverse it rapidly, yielding a time response comparable to PME. The Conduino's multi-channel capability is used to operate probe arrays, which helps to construct density fields in stratified flows.

  10. Pulmonary exposure to particles from diesel exhaust, urban dust or single-walled carbon nanotubes and oxidatively damaged DNA and vascular function in apoE(-/-)mice

    DEFF Research Database (Denmark)

    Vesterdal, Lise K; Jantzen, Kim; Sheykhzade, Majid

    2012-01-01

    Abstract This study compared the oxidative stress level and vasomotor dysfunction after exposure to urban dust, diesel exhaust particles (DEP) or single-walled carbon nanotubes (SWCNT). DEP and SWCNT increased the production of reactive oxygen species (ROS) in cultured endothelial cells and acell......Abstract This study compared the oxidative stress level and vasomotor dysfunction after exposure to urban dust, diesel exhaust particles (DEP) or single-walled carbon nanotubes (SWCNT). DEP and SWCNT increased the production of reactive oxygen species (ROS) in cultured endothelial cells...... and acellullarly, whereas the exposure to urban dust did not generate ROS. ApoE(-/-) mice, which were exposed twice to 0.5 mg/kg of the particles by intratracheal instillation, had unaltered acetylcholine-elicited vasorelaxation in aorta segments. There was unaltered pulmonary expression level of Vcam-1, Icam-1...

  11. Oxygen exchange and diffusion coefficients of strontium-doped lanthanum ferrites by electrical conductivity relaxation

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Lankhorst, M.H.R.; Lankhorst, M.H.R.; Bouwmeester, Henricus J.M.

    1997-01-01

    Electrical conductivity relaxation experiments were performed on thin specimens of La1–xSrxFeO3–delta (x = 0.1, 0.4) at oxygen partial pressures pO2 = 10–5 – 1 bar in the temperature range 923 to 1223 K. The transient response of the electrical conductivity after a sudden change of the ambient

  12. Cotton fabric coated with conducting polymers and its application in monitoring of carnivorous plant response

    Czech Academy of Sciences Publication Activity Database

    Bajgar, V.; Penhaker, M.; Martinková, L.; Pavlovič, A.; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav

    2016-01-01

    Roč. 16, č. 4 (2016), 498_1-498_12 ISSN 1424-8220 R&D Projects: GA TA ČR(CZ) TE01020022 Institutional support: RVO:61389013 Keywords : conducting polymers * plant neurobiology * polyaniline Subject RIV: CG - Electrochemistry Impact factor: 2.677, year: 2016

  13. Conduction velocity is regulated by sodium channel inactivation in unmyelinated axons innervating the rat cranial meninges.

    Science.gov (United States)

    De Col, Roberto; Messlinger, Karl; Carr, Richard W

    2008-02-15

    Axonal conduction velocity varies according to the level of preceding impulse activity. In unmyelinated axons this typically results in a slowing of conduction velocity and a parallel increase in threshold. It is currently held that Na(+)-K(+)-ATPase-dependent axonal hyperpolarization is responsible for this slowing but this has long been equivocal. We therefore examined conduction velocity changes during repetitive activation of single unmyelinated axons innervating the rat cranial meninges. In direct contradiction to the currently accepted postulate, Na(+)-K(+)-ATPase blockade actually enhanced activity-induced conduction velocity slowing, while the degree of velocity slowing was curtailed in the presence of lidocaine (10-300 microm) and carbamazepine (30-500 microm) but not tetrodotoxin (TTX, 10-80 nm). This suggests that a change in the number of available sodium channels is the most prominent factor responsible for activity-induced changes in conduction velocity in unmyelinated axons. At moderate stimulus frequencies, axonal conduction velocity is determined by an interaction between residual sodium channel inactivation following each impulse and the retrieval of channels from inactivation by a concomitant Na(+)-K(+)-ATPase-mediated hyperpolarization. Since the process is primarily dependent upon sodium channel availability, tracking conduction velocity provides a means of accessing relative changes in the excitability of nociceptive neurons.

  14. Complex conductivity of oil-contaminated clayey soils

    Science.gov (United States)

    Deng, Y.; Revil, A.; Shi, X.

    2017-12-01

    Non-intrusive hydrogeophysical techniques have been wildly applied to detect organic contaminants because of the difference of electrical properties for contaminated soil. Among them, spectral induced polarization (SIP) has emerged as a promising tool for the identification of contamination due to its sensitivity to the chemistry of pore water, solid-fluid interfaces and fluid content. Previous works have investigated the influences of oil on the electrical signatures of porous media, which demonstrated the potentials of SIP in the detection of hydrocarbon contamination. However, few works have done on the SIP response of oil in clayey soils. In this study, we perform a set of SIP measurements on the clayey samples under different water saturations. These clayey soils are characterized by relatively high cation exchange capacity. The objective in this work is to test the empirical relationships between the three exponents, including the cementation exponent (m), the saturation exponent (n) and the quadrature conductivity exponent (p), which is expected to reduce the model parameters needed in geophysical and hydraulic properties predictions. Our results show that the complex conductivity are saturation dependent. The magnitude of both in-phase and quadrature conductivities generally decrease with decreasing water saturation. The shape of quadrature conductivity spectra slightly changes when water saturation decreases in some cases. The saturation exponent slightly increases with cation exchange capacity, specific surface area and clay content, with an average value around 2.05. Compared to saturation exponent, the quadrature conductivity exponent apparently increases with cation exchange capacity and specific surface area while has little to do with the clay content. Further, the results indicate that the quadrature conductivity exponent p does not strictly obey to p=n-1 as proposed by Vinegar and Waxman (1984). Instead, it mostly ranges between p=n-1.5 and p=n-0

  15. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  16. The Jeremiah Metzger Lecture. The pathogenesis of fever in human subjects.

    Science.gov (United States)

    Wolff, S. M.; Dinarello, C. A.

    1980-01-01

    The pathogenesis of fever in man begins with the production of endogenous pyrogen by phagocytic leukocytes in response to exogenous pyrogens (toxic, immunologic or infectious agents). Endogenous pyrogen, a protein, is released from a variety of phagocytic leukocytes and enters the circulation after new messenger RNA and protein are synthesized. Fever is caused by an interaction of endogenous pyrogen with specialized receptors on or near thermosensitive neurons in the thermoregulatory center of the anterior hypothalamus. This interaction may cause local hypothalamic production of prostaglandins, monoamines and, possibly, cyclic AMP. From the anterior hypothalamus, information is transmitted through the posterior hypothalamus to the vasomotor center, which directs sympathetic-nerve fibers to constrict peripheral vessels and decrease heat dissipation. PMID:552177

  17. Electrospun poly(lactic acid) based conducting nanofibrous networks

    International Nuclear Information System (INIS)

    Patra, S N; Bhattacharyya, D; Ray, S; Easteal, A J

    2009-01-01

    Multi-functionalised micro/nanostructures of conducting polymers in neat or blended forms have received much attention because of their unique properties and technological applications in electrical, magnetic and biomedical devices. Biopolymer-based conducting fibrous mats are of special interest for tissue engineering because they not only physically support tissue growth but also are electrically conductive, and thus are able to stimulate specific cell functions or trigger cell responses. They are effective for carrying current in biological environments and can thus be considered for delivering local electrical stimuli at the site of damaged tissue to promote wound healing. Electrospinning is an established way to process polymer solutions or melts into continuous fibres with diameter often in the nanometre range. This process primarily depends on a number of parameters, including the type of polymer, solution viscosity, polarity and surface tension of the solvent, electric field strength and the distance between the spinneret and the collector. The present research has included polyaniline (PANi) as the conducting polymer and poly(L-lactic acid) (PLLA) as the biopolymer. Dodecylbenzene sulphonic acid (DBSA) doped PANi and PLLA have been dissolved in a common solvent (mixtures of chloroform and dimethyl formamide (DMF)), and the solutions successfully electrospun. DMF enhanced the dielectric constant of the solvent, and tetra butyl ammonium bromide (TBAB) was used as an additive to increase the conductivity of the solution. DBSA-doped PANi/PLLA mat exhibits an almost bead-free network of nanofibres that have extraordinarily smooth surface and diameters in the range 75 to 100 nm.

  18. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature Tc of the Sn films. The temperature dependence of the cosφ conductance is determined from the resonant response at the junction plasma frequency fp...

  19. 49 CFR Appendix to Subtitle A - United States Railway Association-Employee Responsibilities and Conduct

    Science.gov (United States)

    2010-10-01

    ... accident insurance plan or other employee welfare or benefit plan that is maintained by a business or... 49 Transportation 1 2010-10-01 2010-10-01 false United States Railway Association-Employee... Subtitle A, App. Appendix to Subtitle A—United States Railway Association—Employee Responsibilities and...

  20. A design of emission regulation with supply side response

    International Nuclear Information System (INIS)

    Matsumoto, Shigeru

    1999-03-01

    Hitherto, supply side response has received little attention in welfare analysis. Without considering that when a policy environmental changes supply side may change production plan in response to it, a policy evaluation has been conducted. Since 1980s, such a policy evaluation without considering supply side response is much dangerous, and sometimes a probability to select incorrect policy evaluation has become suggested. When government conducts its policy change, expected profit in enterprise changes. Therefore, enterprise must be remade up an optimum strategy on a base of this new expected profit. If an aim of government consists in to maximize welfare of whole society, government needs to conduct a policy evaluation due to welfare analysis under considering such background, here is described to propose an environmental policy considering supply side response. (G.K.)

  1. Simulation of the transient eddy current measurement for the characterization of depth and conductivity of a plate

    International Nuclear Information System (INIS)

    Cheng, Weiying; Komura, Ichiro

    2008-01-01

    A transient eddy current measurement method is presented to determine the thickness and conductivity of a conductive plate. The conductive plate is induced by an air-cored coil, the magnetic flux density along the axial is measured and the various signals corresponding to plates with different thickness and conductivity are calculated using a 3D transient eddy current simulator. Characteristic features are obtained from the transient response. A similarity-based modeling method is utilized in this study to estimate the thickness and conductivity of the conductive plate. (author)

  2. The scattering of electromagnetic pulses by a slit in a conducting screen

    Science.gov (United States)

    Ackerknecht, W. E., III; Chen, C.-L.

    1975-01-01

    A direct method for calculating the impulse response of a slit in a conducting screen is presented which is derived specifically for the analysis of transient scattering by two-dimensional objects illuminated by a plane incident wave. The impulse response is obtained by assuming that the total response is composed of two sequences of diffracted waves. The solution is determined for the first two waves in one sequence by using Green's functions and the equivalence principle, for additional waves in the sequence by iteration, and for the other sequence by a transformation of coordinates. The cases of E-polarization and H-polarization are considered.

  3. Post-market clinical research conducted by medical device manufacturers: a cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Ross JS

    2015-05-01

    Full Text Available Joseph S Ross, Katrina L Blount, Jessica D Ritchie, Beth Hodshon, Harlan M Krumholz Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, CT, USA Background: In the US, once a medical device is made available for use, several requirements have been established by the US Food and Drug Administration (FDA to ensure ongoing post-market surveillance of device safety and effectiveness. Our objective was to determine how commonly medical device manufacturers initiate post-market clinical studies or augment FDA post-market surveillance requirements for higher-risk devices that are most often approved via the FDA's pre-market approval (PMA pathway. Methods and results: We conducted a cross-sectional survey of 47 manufacturers with operations in California, Minnesota, and Massachusetts who market devices approved via the PMA pathway. Among 22 respondents (response rate =47%, nearly all self-reported conducting post-market clinical research studies, commonly between 1 and 5; only 1 respondent reported never conducting post-market clinical research studies. While manufacturers most often engaged in these studies to satisfy FDA requirements, other reasons were reported, including performance monitoring and surveillance and market acceptance initiatives. Risks of conducting and not conducting post-market clinical research studies were described through open-ended response to questions. Conclusion: Medical device manufacturers commonly initiate post-market clinical studies at the request of the FDA. Clinical data from these studies should be integrated into national post-market surveillance initiatives. Keywords: FDA, PMA pathway, post-market surveillance

  4. Cellular elements for seeing in the dark: voltage-dependent conductances in cockroach photoreceptors

    Directory of Open Access Journals (Sweden)

    Salmela Iikka

    2012-08-01

    Full Text Available Abstract Background The importance of voltage-dependent conductances in sensory information processing is well-established in insect photoreceptors. Here we present the characterization of electrical properties in photoreceptors of the cockroach (Periplaneta americana, a nocturnal insect with a visual system adapted for dim light. Results Whole-cell patch-clamped photoreceptors had high capacitances and input resistances, indicating large photosensitive rhabdomeres suitable for efficient photon capture and amplification of small photocurrents at low light levels. Two voltage-dependent potassium conductances were found in the photoreceptors: a delayed rectifier type (KDR and a fast transient inactivating type (KA. Activation of KDR occurred during physiological voltage responses induced by light stimulation, whereas KA was nearly fully inactivated already at the dark resting potential. In addition, hyperpolarization of photoreceptors activated a small-amplitude inward-rectifying (IR current mediated at least partially by chloride. Computer simulations showed that KDR shapes light responses by opposing the light-induced depolarization and speeding up the membrane time constant, whereas KA and IR have a negligible role in the majority of cells. However, larger KA conductances were found in smaller and rapidly adapting photoreceptors, where KA could have a functional role. Conclusions The relative expression of KA and KDR in cockroach photoreceptors was opposite to the previously hypothesized framework for dark-active insects, necessitating further comparative work on the conductances. In general, the varying deployment of stereotypical K+ conductances in insect photoreceptors highlights their functional flexibility in neural coding.

  5. Comparison of vibrational conductivity and radiative energy transfer methods

    Science.gov (United States)

    Le Bot, A.

    2005-05-01

    This paper is concerned with the comparison of two methods well suited for the prediction of the wideband response of built-up structures subjected to high-frequency vibrational excitation. The first method is sometimes called the vibrational conductivity method and the second one is rather known as the radiosity method in the field of acoustics, or the radiative energy transfer method. Both are based on quite similar physical assumptions i.e. uncorrelated sources, mean response and high-frequency excitation. Both are based on analogies with some equations encountered in the field of heat transfer. However these models do not lead to similar results. This paper compares the two methods. Some numerical simulations on a pair of plates joined along one edge are provided to illustrate the discussion.

  6. Development of conductivity probe and temperature probe for in-situ measurements in hydrological studies

    International Nuclear Information System (INIS)

    Chandra, U.; Galindo, B.J.; Castagnet, A.C.G.

    1981-05-01

    A conductivity probe and a temperature probe have been developed for in-situ measurements in various hydrological field studies. The conductivity probe has platinum electrodes and is powered with two 12 volt batteries. The sensing element of the temperature probe consists of a resistor of high coefficient of temperature. Response of the conductivity probe is measured in a milliampere mater while the resistance of the thermistor is read by a digital meter. The values of conductivity and temperature are derived from respective calibration. The probes are prototype and their range of measurement can be improved depending upon the requirement of the field problem. (Author) [pt

  7. The modelling and measurement of super-conducting rock joints

    International Nuclear Information System (INIS)

    Barton, N.; Makurat, A.; Vik, G.; Loset, F.

    1985-01-01

    Rock joints exhibiting exceptionally high conductivity have been responsible for severe inflows (10-50 m 3 /min.) and flooding in recent Norwegian tunneling projects. These events may be explained by channeling of flow in partially outwashed mineral fillings, associated with deep weathering in ancient basement rocks. There is also evidence to suggest extensional strain with consistent relationships to regional faulting patterns (Selmer-Olsen 1981). Hydraulic fractures making connection with joint systems that are sheared as a result of increased fluid pressure, has been deduced as the mechanism explaining unusually large fluid losses in the geothermal project in Cornwall, England (Pine and Batchelor, 1984). Such mechanisms also introduce uncertainty into water flood and MHF stimulation treatment of fractured oil and gas reservoirs, particularly when principal stress and joint orientations are poorly understood due to coring and stress measurement problems in weak, overstressed reservoir rocks. The possibility of permanent disposal of nuclear waste in crystalline rock, has also focussed attention on highly conductive (''super-conducting'') joints in nuclear waste programmes in Canada, the USA and in Europe. The bi-modal distributions of joint spacing, continuity, apertures and conductivities resulting from the discovery of super-conducting joints has important implications for the location of planned repositories, due to their dramatic impact on potential transport times. In the laboratory a class of super-conducting joints can be created by shear displacement that causes dilation when shearing non-planar features. Recent biaxial shear testing of rock joints recovered in jointed core has identified a strong coupling of conductivity and shear displacement. The theoretical predictions of constitutive relationships for coupled flow in rock joints (Barton et al. 1985) have been broadly verified

  8. Recovery of Ventriculo-Atrial Conduction after Adrenaline in Patients Implanted with Pacemakers.

    Science.gov (United States)

    Cismaru, Gabriel; Gusetu, Gabriel; Muresan, Lucian; Rosu, Radu; Andronache, Marius; Matuz, Roxana; Puiu, Mihai; Mester, Petru; Miclaus, Maria; Pop, Dana; Mircea, Petru Adrian; Zdrenghea, Dumitru

    2015-07-01

    Ventriculo-atrial (VA) conduction can have negative consequences for patients with implanted pacemakers and defibrillators. There is concern whether impaired VA conduction could recover during stressful situations. Although the influence of isoproterenol and atropine are well established, the effect of adrenaline has not been studied systematically. The objective of this study was to determine if adrenaline can facilitate recovery of VA conduction in patients implanted with pacemakers. A prospective study was conducted on 61 consecutive patients during a 4-month period (April-July 2014). The presence of VA conduction was assessed during the pacemaker implantation procedure. In case of an impaired VA conduction, adrenaline infusio was used as a stress surrogate to test conduction recovery. The indications for pacemaker implantation were: sinus node dysfunction in 18 patients, atrioventricular (AV) block in 40 patients, binodal dysfunction (sinus node+ AV node) in two patients and other (carotid sinus syndrome) in one patient. In the basal state, 15/61 (24.6%) presented spontaneous VA conduction and 46/61 (75.4%) had no VA conduction. After administration of adrenaline, there was VA conduction recovery in 5/46 (10.9%) patients. Adrenaline infusion produced recovery of VA conduction in 10.9% of patients with absent VA conduction in a basal state. Recovery of VA conduction during physiological or pathological stresses could be responsible for the pacemaker syndrome, PMT episodes, or certain implantable cardiac defibrillator detection issues. © 2015 Wiley Periodicals, Inc.

  9. Electrically Conductive TPU Nanofibrous Composite with High Stretchability for Flexible Strain Sensor

    Science.gov (United States)

    Tong, Lu; Wang, Xiao-Xiong; He, Xiao-Xiao; Nie, Guang-Di; Zhang, Jun; Zhang, Bin; Guo, Wen-Zhe; Long, Yun-Ze

    2018-03-01

    Highly stretchable and electrically conductive thermoplastic polyurethane (TPU) nanofibrous composite based on electrospinning for flexible strain sensor and stretchable conductor has been fabricated via in situ polymerization of polyaniline (PANI) on TPU nanofibrous membrane. The PANI/TPU membrane-based sensor could detect a strain from 0 to 160% with fast response and excellent stability. Meanwhile, the TPU composite has good stability and durability. Besides, the composite could be adapted to various non-flat working environments and could maintain opportune conductivity at different operating temperatures. This work provides an easy operating and low-cost method to fabricate highly stretchable and electrically conductive nanofibrous membrane, which could be applied to detect quick and tiny human actions.

  10. Conductivity in redox modified conducting polymers. In-situ conductivity of poly(cyclopentadithiophenes) bearing p-nitrophenyl and 4-N-methylpyridinium groups

    Energy Technology Data Exchange (ETDEWEB)

    Zotti, G. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa; Berlin, A. [Milan Univ. (Italy). Dipartimento di Chimica Organica e Industriale; Pagani, G. [Milan Univ. (Italy). Dipartimento di Chimica Organica e Industriale; Schiavon, G. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa; Zecchin, S. [Consiglio Nazionale delle Ricerche, (Italy). Istituto di Polarografia ed Elettrochimica Preparativa

    1995-01-01

    Redox-modified polythiophenes exhibiting the highest mixed-valence conductivities of any polymer containing a pendant redox group are reported. The ordering of the polymer, in which the backbone has been oxidized to a bipolaron conducting state and the redox sites have been reduced to a mixed-valence conducting state, encourages inter-site hopping and results in the high conductivities. Electron interactions are shown not have an influence on the conduction. (orig.)

  11. Enhanced ionic conductivity in composite materials due to interfacial space charge layers

    International Nuclear Information System (INIS)

    Dudney, N.J.

    1985-01-01

    The ionic conductivity of a number of salts (e.g., β-AgI, LiI, CuCl, HgI 2 , etc.) can be enhanced by one to three orders of magnitude with the addition of fine particles of an insoluble and nonconducting material such as Al 2 O 3 or SiO 2 . Typically the conductivity increases with addition of the inert particles and reaches a peak at 10-40 vol % of the particles. The mechanism responsible for the enhanced conductivity of the composite is not understood at this time. Some claim that this effect is due to an increased concentration of charge carriers in a diffuse space charge layer near the charged surface of the particle. The goal of the present study is to test this proposed mechanism by calculating the maximum space charge layer effect and then using this result to estimate the conductivity of a composite with a random distribution of Al 2 O 3 particles. Also, the conductivity of composite systems has been investigated assuming an ordered distribution of particles which are surrounded by a high conductivity layer

  12. The DC electrical conductivity calculation purely from the dissipative component of the AC conductivity III. statistical ensemble inherent to state with DC current

    International Nuclear Information System (INIS)

    Milinski, N.; Milinski, E.

    2002-01-01

    Amorphous conductors such as liquid metals and alloys are subject to dc conductivity σ calculation here. Principal aim is to explore the impact on σ of the constitutive equation α * = 1, formulated and developed in the preceding papers. The nearly free electrons (NFE) model has been applied. Alkali metals are assumed to fit this model well, and sodium the best. Consequently, the results on these metals have been assumed reliable and relevant for conclusions making. The conclusion we made is: instead of the Fermi radius k f proper for the statistical ensemble in state of thermodynamics equilibrium, a new k ' f number is needed to be introduced into the linear response formula when calculating σ and α * . This k ' f is the length of the corresponding axis of ellipsoid proper for describing the statistical ensemble in the state with dc current. In the traditional interpretation of the linear response formula (Kubo formula) this conversion has been overlooked. Parameters of the mentioned ellipsoids are determined in this paper for a number of liquid metals of valency numbers 1,2,3,4, in addition to a selection of some binary and ternary conducting alloys. It is up to experimental measurements to decide how real this concept of restructuring the statistical ensemble is. (Authors)

  13. Conduct of operations: The foundation of safety -- An overview

    International Nuclear Information System (INIS)

    Willett, D.J.; Hertel, N.E.

    1992-05-01

    This paper discusses issues and approaches dealing with conceptualizing, implementing, and maintaining configuration control commensurate with the conduct of operations approach defined by DOE ORDER 5480.19. Specific topics reviewed will include key elements of assessments to determine the status quo such as assessment criteria, assessment personnel, and assessment scope; administrative programs to maintain the status quo such as organizational definition, responsibilities, interfaces, and priorities; oversight to determine control effectiveness via compliance and performance assessment

  14. Investigation on two abnormal phenomena about thermal conductivity enhancement of BN/EG nanofluids.

    Science.gov (United States)

    Li, Yanjiao; Zhou, Jing'en; Luo, Zhifeng; Tung, Simon; Schneider, Eric; Wu, Jiangtao; Li, Xiaojing

    2011-07-09

    The thermal conductivity of boron nitride/ethylene glycol (BN/EG) nanofluids was investigated by transient hot-wire method and two abnormal phenomena was reported. One is the abnormal higher thermal conductivity enhancement for BN/EG nanofluids at very low-volume fraction of particles, and the other is the thermal conductivity enhancement of BN/EG nanofluids synthesized with large BN nanoparticles (140 nm) which is higher than that synthesized with small BN nanoparticles (70 nm). The chain-like loose aggregation of nanoparticles is responsible for the abnormal increment of thermal conductivity enhancement for the BN/EG nanofluids at very low particles volume fraction. And the difference in specific surface area and aspect ratio of BN nanoparticles may be the main reasons for the abnormal difference between thermal conductivity enhancements for BN/EG nanofluids prepared with 140- and 70-nm BN nanoparticles, respectively.

  15. Grain boundary and grain interior conduction in γ'-Bi2MoO6

    International Nuclear Information System (INIS)

    Vera, C.M.C.; Aragon, R.

    2005-01-01

    Impedance spectroscopy of fine grained ( 2 MoO 6 samples, in the frequency range of 0.1 Hz-250 kHz, relevant to sensor applications, up to 800 deg. C, has been used to characterize grain boundary and grain interior contributions to conduction. Above 500 deg. C, the grain boundary contribution is no longer rate limiting and conduction is dominated by the grain interior component. The corresponding activation energies are 0.98 eV for grain boundary and 0.73 eV for grain interior components. The weak dependence of conductivity on oxygen partial pressure below 500 deg. C can be attributed to electrode-electrolyte interface phenomena, whereas the robust response to ethanol is commensurate with changes in intrinsic ionic conductivity

  16. Social responsibility as modern conception of business

    OpenAIRE

    Vorona, E.

    2010-01-01

    Research of social responsibility is conducted in the context of theory of socialization of the economic systems. Approaches are considered to essence of concept «Social responsibility». The positive consequences of realization of social responsibility and its connection are certain with a competitiveness and efficiency

  17. Emergency response training with the BNL plant analyzer

    International Nuclear Information System (INIS)

    Cheng, H.S.; Guppy, J.G.; Mallen, A.N.; Wulff, W.

    1987-01-01

    Presented is the experience in the use of the BNL Plant Analyzer for NRC emergency response training to simulated accidents in a BWR. The unique features of the BNL Plant Analyzer that are important for the emergency response training are summarized. A closed-loop simulation of all the key systems of a power plant in question was found essential to the realism of the emergency drills conducted at NRC. The faster than real-time simulation speeds afforded by the BNL Plant Analyzer have demonstrated its usefulness for the timely conduct of the emergency response training

  18. Experimental determination of thermal conductivity and gap conductance of fuel rod for HTGR

    International Nuclear Information System (INIS)

    Kikuchi, Teruo; Iwamoto, Kazumi; Ikawa, Katsuichi; Ishimoto, Kiyoshi

    1985-01-01

    The thermal conductivity of fuel compacts and the gap conductance between the fuel compact and the graphite sleeve in fuel rods for a high-temperature gas-cooled reactor (HTGR) were measured by the center heating method. These measurements were made as functions of volume percent particle loading and temperature for thermal conductivity and as functions of gap distance and gas composition for gap conductance. The thermal conductivity of fuel compacts decreases with increasing temperature and with increasing particle loading. The gap conductance increases with increasing temperature and decrease with increasing gap distance. A good gap conductance was observed with helium fill gas. It was seen that the gap conductance was dependent on the thermal conductivity of fill gas and conductance by radiation and could be neglected the conductance through solid-solid contact points of fuel compact and graphite sleeve. (author)

  19. High-conductance states in a mean-field cortical network model

    DEFF Research Database (Denmark)

    Lerchner, Alexander; Ahmadi, Mandana; Hertz, John

    2004-01-01

    cortical network model with random connectivity and conductance-based synapses. We employ mean-field theory with correctly colored noise to describe temporal correlations in the neuronal activity. Our results illuminate the connection between two independent experimental findings: high-conductance states......Measured responses from visual cortical neurons show that spike times tend to be correlated rather than exactly Poisson distributed. Fano factors vary and are usually greater than 1, indicating a tendency toward spikes being clustered. We show that this behavior emerges naturally in a balanced...... of cortical neurons in their natural environment, and variable non-Poissonian spike statistics with Fano factors greater than 1. (C) 2004 Elsevier B.V. All rights reserved....

  20. Electrical conductivity of polyaniline/zeolite composites and synergetic interaction with CO

    International Nuclear Information System (INIS)

    Densakulprasert, Nataporn; Wannatong, Ladawan; Chotpattananont, Datchanee; Hiamtup, Piyanoot; Sirivat, Anuvat; Schwank, Johannes

    2005-01-01

    The effects of zeolite content, pore size and ion exchange capacity on electrical conductivity response to carbon monoxide (CO) of polyaniline/zeolite composites were investigated. Zeolite Y, 13X, and synthesized AlMCM41, all having the common cation Cu 2+ , were dry mixed with synthesized maleic acid (MA) doped polyaniline and compressed to form polyaniline (PANI)/zeolite pellet composites. The Y, 13X and AlMCM41 zeolite have the nominal pore sizes of 7, 10, 36 A, and the Cu 2+ exchange capacities of 0.161, 0.087, and 0.044 mol/g, respectively. With an addition of 13X zeolite to pristine polyaniline, the electrical conductivity sensitivity to CO/N 2 gas increases with zeolite content. For the effect of zeolite type, the highest electrical conductivity sensitivity is obtained with the 13X zeolite, followed by the Y zeolite, and the AlMCM41 zeolite, respectively. Poor sensitivity of zeolite AlMCM41 is probably due to its very large pore size and its lowest Cu 2+ exchange capacity. Y zeolite and 13X zeolite have comparable pore sizes but the latter has a greater pore free volume and a more favorable location distribution of the Cu 2+ ions within the pore. The temporal response time increases with the amount of zeolite in the composites but it is inversely related to the amount of ion exchange capacity

  1. Box–Behnken experimental design for investigation of stability and thermal conductivity of TiO2 nanofluids

    International Nuclear Information System (INIS)

    Lotfizadeh Dehkordi, Babak; Ghadimi, Azadeh; Metselaar, Henk S. C.

    2013-01-01

    The aim of this study is to investigate the effect of ultrasonication on the stability and thermal conductivity of TiO 2 water nanofluids. A UV–Vis spectrophotometer was employed to determine the relative stability of nanofluids. Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of power of sonication (20–80 %), time of sonication (2–20 min), and volume concentration (0.1–1 vol%) of nanofluids as the independent variables. Second-order polynomial equations were established to predict the responses, thermal conductivity, and stability of nanofluids with the intervals of 1 week and 1 month. The significance of the models was tested by means of analysis of variance (ANOVA). The optimum stability and thermal conductivity of TiO 2 nanofluids with various sonication power and time at volume concentrations of 0.1, 0.55, and 1 % were studied. In addition, a correlation between the stability and thermal conductivity enhancement was derived in this study. The results revealed that, at low concentrations, nanofluids would become stable by low power and short period of sonication; however, no enhancement was observed in the thermal conductivity. Conversely, at high concentrations, stability and high thermal conductivity of nanofluids coincided at 1 vol%.

  2. Density-matrix renormalization group method for the conductance of one-dimensional correlated systems using the Kubo formula

    Science.gov (United States)

    Bischoff, Jan-Moritz; Jeckelmann, Eric

    2017-11-01

    We improve the density-matrix renormalization group (DMRG) evaluation of the Kubo formula for the zero-temperature linear conductance of one-dimensional correlated systems. The dynamical DMRG is used to compute the linear response of a finite system to an applied ac source-drain voltage; then the low-frequency finite-system response is extrapolated to the thermodynamic limit to obtain the dc conductance of an infinite system. The method is demonstrated on the one-dimensional spinless fermion model at half filling. Our method is able to replicate several predictions of the Luttinger liquid theory such as the renormalization of the conductance in a homogeneous conductor, the universal effects of a single barrier, and the resonant tunneling through a double barrier.

  3. Emergency preparedness exercises for nuclear facilities: Preparation, conduct and evaluation

    International Nuclear Information System (INIS)

    1985-01-01

    This publication offers guidance for operating organizations and public authorities on planning, organizing and conducting exercises, preparing scenarios and evaluating the results of exercises in order to make full use of the experience gained in improving the response planning and preparedness for radiation emergencies. The training aspects associated with achieving an adequate level of emergency preparedness are explored and examples of accident scenarios are presented

  4. The effects of progesterone selection on psychological symptoms in hormone replacement therapy.

    Science.gov (United States)

    Caglayan, Emel Kiyak; Kara, Mustafa; Etiz, Sema; Kumru, Pinar; Aka, Nurettin; Kose, Gultekin

    2014-01-01

    The aim of this study is to evaluate the effects of hormone replacement therapy using dienogest and medroxyprogesterone acetate on psychological symptoms in perimenopausal and postmenopausal women. A total of 73 patients who sought treatment at the menopause units of the authors' gynecology and obstetrics clinics between of November 2003 and October 2004 complaining of vasomotor symptoms were included in the study prospectively. The cases were divided into two groups: Group I (37 patients) was given 2 mg estradiol valerate and 2 mg dienogest, and Group II (36 patients) was given 2 mg estradiol valerate and 10 mg medroxyprogesterone acetate. The groups' results in months 0 and 6 were compared through the evaluation of vasomotor and psychological symptom levels. No significant difference was found between the groups when the initial levels of vasomotor and psychological symptom subtypes were compared (p = 0.16). It was observed that all the psychological symptoms decreased in the 6th month in the group using dienogest in comparison with the initial situation, and that psychological symptoms increased in the group using medroxyprogesterone acetate in the evaluation performed in the 6th month compared with the initial levels. It was also found out that there was a statistically significant difference between the two groups when compared in terms of these symptoms (p psychological situation and sleep, it was observed that the use of medroxyprogesterone acetate (MPA) worsens the general psychological situation.

  5. Laboratory performance of sweat conductivity for the screening of cystic fibrosis.

    Science.gov (United States)

    Greaves, Ronda F; Jolly, Lisa; Massie, John; Scott, Sue; Wiley, Veronica C; Metz, Michael P; Mackay, Richard J

    2018-03-28

    There are several complementary English-language guidelines for the performance of the sweat chloride test. These guidelines also incorporate information for the collection of conductivity samples. However, recommendations for the measurement and reporting of sweat conductivity are less clear than for sweat chloride. The aim of the study was to develop an understanding of the testing and reporting practices of sweat conductivity in Australasian laboratories. A survey specifically directed at conductivity testing was sent to the 12 laboratories registered with the Royal College of Pathologists of Australasia Quality Assurance Programs. Nine (75%) laboratories participated in the survey, seven of whom used Wescor Macroduct® for collecting sweat and the Wescor SWEAT·CHEK™ for conductivity testing, and the remaining two used the Wescor Nanoduct®. There was considerable variation in frequency and staffing for this test. Likewise, criteria about which patients it was inappropriate to test, definitions of adequate collection sweat rate, cutoffs and actions recommended on the basis of the result showed variations between laboratories. Variations in sweat conductivity testing and reporting reflect many of the same issues that were revealed in sweat chloride test audits and have the potential to lead to uncertainty about the result and the proper action in response to the result. We recommend that sweat testing guidelines should include clearer statements about the use of sweat conductivity.

  6. Response of two-band systems to a single-mode quantized field

    Science.gov (United States)

    Shi, Z. C.; Shen, H. Z.; Wang, W.; Yi, X. X.

    2016-03-01

    The response of topological insulators (TIs) to an external weakly classical field can be expressed in terms of Kubo formula, which predicts quantized Hall conductivity of the quantum Hall family. The response of TIs to a single-mode quantized field, however, remains unexplored. In this work, we take the quantum nature of the external field into account and define a Hall conductance to characterize the linear response of a two-band system to the quantized field. The theory is then applied to topological insulators. Comparisons with the traditional Hall conductance are presented and discussed.

  7. Investigation on two abnormal phenomena about thermal conductivity enhancement of BN/EG nanofluids

    Directory of Open Access Journals (Sweden)

    Wu Jiangtao

    2011-01-01

    Full Text Available Abstract The thermal conductivity of boron nitride/ethylene glycol (BN/EG nanofluids was investigated by transient hot-wire method and two abnormal phenomena was reported. One is the abnormal higher thermal conductivity enhancement for BN/EG nanofluids at very low-volume fraction of particles, and the other is the thermal conductivity enhancement of BN/EG nanofluids synthesized with large BN nanoparticles (140 nm which is higher than that synthesized with small BN nanoparticles (70 nm. The chain-like loose aggregation of nanoparticles is responsible for the abnormal increment of thermal conductivity enhancement for the BN/EG nanofluids at very low particles volume fraction. And the difference in specific surface area and aspect ratio of BN nanoparticles may be the main reasons for the abnormal difference between thermal conductivity enhancements for BN/EG nanofluids prepared with 140- and 70-nm BN nanoparticles, respectively.

  8. Maternal Attachment Status, Mother-Child Emotion Talk, Emotion Understanding, and Child Conduct Problems

    Directory of Open Access Journals (Sweden)

    Brad M. Farrant

    2013-01-01

    Full Text Available Conduct problems that emerge in childhood often persist into adolescence and are associated with a range of negative outcomes. It is therefore important to identify the factors that predict conduct problems in early childhood. The present study investigated the relations among maternal attachment status, mother-child emotion talk, child emotion understanding, and conduct problems in a sample of 92 (46 males typically developing children (M age = 61.3 months, SD = 8.3 months. The results support a model in which maternal attachment status predicts the level of appropriate/responsive mother-child emotion talk, which predicts child emotion understanding, which in turn negatively predicts child conduct problems. These findings further underline the developmental role of mother-child emotion talk as well as the importance of involving parents in programs designed to increase children’s emotion understanding and/or decrease the incidence of conduct problems.

  9. Conductivities from attractors

    Energy Technology Data Exchange (ETDEWEB)

    Erdmenger, Johanna [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Fernández, Daniel [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavík (Iceland); Goulart, Prieslei [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany); Instituto de Física Teórica, UNESP-Universidade Estadual Paulista,R. Dr. Bento T. Ferraz 271, Bl. II, São Paulo 01140-070, SP (Brazil); Witkowski, Piotr [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 Munich (Germany)

    2017-03-28

    In the context of applications of the AdS/CFT correspondence to condensed matter physics, we compute conductivities for field theory duals of dyonic planar black holes in 3+1-dimensional Einstein-Maxwell-dilaton theories at zero temperature. We combine the near-horizon data obtained via Sen’s entropy function formalism with known expressions for conductivities. In this way we express the conductivities in terms of the extremal black hole charges. We apply our approach to three different examples for dilaton theories for which the background geometry is not known explicitly. For a constant scalar potential, the thermoelectric conductivity explicitly scales as α{sub xy}∼N{sup 3/2}, as expected. For the same model, our approach yields a finite result for the heat conductivity κ/T∝N{sup 3/2} even for T→0.

  10. Thermal conductance of heat transfer interfaces for conductively cooled superconducting magnets

    International Nuclear Information System (INIS)

    Cooper, T.L.; Walters, J.D.; Fikse, T.H.

    1996-01-01

    Minimizing thermal resistances across interfaces is critical for efficient thermal performance of conductively cooled superconducting magnet systems. Thermal conductance measurements have been made for a flexible thermal coupling, designed to accommodate magnet-to-cryocooler and cryocooler-to-shield relative motion, and an interface incorporating Multilam designed as a sliding thermal connector for cryocoolers. Temperature changes were measured across each interface as a function of heat input. Thermal conductances have been calculated for each interface, and the impact of each interface on conductively cooled magnet systems will be discussed

  11. Ocular vestibular evoked myogenic potentials in response to air-conducted 500 Hz short tones: Effect of stimulation procedure (monaural or binaural), age and gender.

    Science.gov (United States)

    Versino, Maurizio; Colnaghi, Silvia; Ranzani, Marina; Alloni, Roberto; Bolis, Carlotta; Sacco, Simone; Moglia, Arrigo; Callieco, Roberto

    2015-01-01

    The ocular vestibular myogenic potentials (oVEMP) can be elicited by monaural air-conducted sound stimulation, and are usually recorded from the contralateral eye. In clinical setting a binaural stimulation would save time and require less effort from the subjects. We evaluated the differences between monaural and binaural stimulation, and the possible effect of age and gender on oVEMP parameters. Air-conducted oVEMP were recorded by binaural and by monaural stimulation in a group of 54 normal subjects, aged from 12 to 83 years, and in 50 vestibular patients. From each side, we measured the latency of the N1 component, and the peak-to-peak N1-P1 amplitude. For both parameters we also computed the asymmetry ratio. In normal subjects binaural stimulation produced slightly larger responses than monaural stimulation; detectability, latency and amplitude ratio were the same for the two techniques. We found no differences related to gender, and the age-induced amplitude decline was likely to be negligible.oVEMP recorded not in an acute phase of their disorder, proved to be abnormal in about 20% of the patients, and the normal or abnormal findings obtained either with monaural or with binaural stimulation were always concordant. The oVEMP obtained after binaural and monaural stimulation are very similar, and they are largely independent from age and gender.

  12. Some considerations regarding the legal responsibility and the social responsibility

    Directory of Open Access Journals (Sweden)

    Diana Anca ARTENE

    2014-12-01

    Full Text Available The judicial responsibility is acknowledged in the judicial doctrine2, as being ‘the starting point’ of the entire social responsibility, position that continues to have from ancient times until today, thus providing an expression of Law on its most concerted form, which reflect the stage of evolution of the entire social life. Expressing forms and realities of social life, both values and norms are ideal standards of conduct, perceived as individual requirements by each member of society3. The human action enforces the compliance of certain rules and its subordination of certain goals and interests, according to a system of principles and criteria; this is because the individual lead his existence in a relational system with others, a system characterized by extensive interactions and interdependencies. In any society may appear different types of conduct, whose broad includes those conformist, innovative, as well as those non-conformists, escapist or deviant. As full integration of the individual in society, legal norms are not an exclusive element; these are the foundation of a set of rules for the most various types. The institution of social responsibility arises precisely in this way, representing a higher level of integration of the individual in the society.

  13. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    OpenAIRE

    Ebadian B.; Parkan MA.

    2002-01-01

    One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic res...

  14. Electrical conductivity of conductive carbon blacks: influence of surface chemistry and topology

    International Nuclear Information System (INIS)

    Pantea, Dana; Darmstadt, Hans; Kaliaguine, Serge; Roy, Christian

    2003-01-01

    Conductive carbon blacks from different manufacturers were studied in order to obtain some insight into the relation between their electrical conductivity and their surface properties. The surface chemistry was studied by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS), whereas the topology of the carbon black surface was investigated using low-pressure nitrogen adsorption. All these techniques yield information on the graphitic character of the surface. In general, the electrical conductivity of the conductive blacks increases with the graphitic character of the surface. For low surface area conductive blacks, the electrical conductivity correlates well with the surface chemistry. In the case of the XPS and SIMS data, this correlation is also valid when other types of carbon blacks such as thermal and furnace blacks are included, confirming the determining influence of the carbon black surface chemistry on the electrical conductivity

  15. Measured Temperature Dependence of the cos-phi Conductance in Josephson Tunnel Junctions

    DEFF Research Database (Denmark)

    Sørensen, O. H.; Mygind, Jesper; Pedersen, Niels Falsig

    1977-01-01

    The temperature dependence of the cosϕ conductance in Sn-O-Sn Josephson tunnel junctions has been measured just below the critical temperature, Tc. From the resonant microwave response at the junction plasma frequency as the temperature is decreased from Tc it is deduced that the amplitude of the...

  16. Persisting soil drought reduces leaf specific conductivity in Scots pine (Pinus sylvestris) and pubescent oak (Quercus pubescens)

    NARCIS (Netherlands)

    Sterck, F.J.; Zweifel, R.; Sass-Klaassen, U.; Qumruzzaman, C.

    2008-01-01

    Summary Leaf specific conductivity (LSC; the ratio of stem conductivity (KP) to leaf area (AL)), a measure of the hydraulic capacity of the stem to supply leaves with water, varies with soil water content. Empirical evidence for LSC responses to drought is ambiguous, because previously published

  17. Career Decision-Making and Corporate Responsibility

    Science.gov (United States)

    Sainty, Rosemary

    2008-01-01

    This paper seeks to investigate the extent of influence of corporate (or organisational) responsibility on university students' career decision-making. It reports on a pilot study conducted at the University of Sydney which aims to: explore students' ethical, professional and social understanding regarding corporate responsibility; determine the…

  18. Role of adenosine in the regulation of coronary blood flow in swine at rest and during treadmill exercise

    NARCIS (Netherlands)

    D.J.G.M. Duncker (Dirk); R. Stubenitsky (René); P.D. Verdouw (Pieter)

    1998-01-01

    textabstractA pivotal role for adenosine in the regulation of coronary blood flow is still controversial. Consequently, we investigated its role in the regulation of coronary vasomotor tone in swine at rest and during graded treadmill exercise. During exercise,

  19. NOAA Emergency Response Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is in response to natural disasters. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The majority...

  20. Electrodermal responses during appetitive conditioning are sensitive to contingency instruction ambiguity.

    Science.gov (United States)

    van den Akker, Karolien; Nederkoorn, Chantal; Jansen, Anita

    2017-08-01

    Studies on human appetitive conditioning using food rewards can benefit from including psychophysiological outcome measures. The present study tested whether the skin conductance response can function as a measure of differential responding in an appetitive conditioning paradigm including an acquisition and extinction phase, and examined which time window during a trial is most sensitive to conditioning effects. As a secondary aim, the effects of ambiguous vs. non-ambiguous contingency instructions on conditioned responses (skin conductance responses, US expectancies, chocolate desires, and CS evaluations) were assessed. Results indicated differential skin conductance responses in an anticipatory time window and during unexpected omission of the US in early extinction. Interestingly however, anticipatory responses were only found for participants who received ambiguous contingency instructions - possibly indicating a call for additional processing resources in response to the ambiguous CS+. Further, ambiguous instructions slowed the extinction of US expectancies but did not influence chocolate desires and CS evaluations. It is concluded that skin conductance can function as a sensitive measure of differential responding in appetitive conditioning, though its sensitivity might depend on the specific task context. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Investigation of surface treatment of conductive wire in cylindrical atmospheric pressure plasmas

    International Nuclear Information System (INIS)

    Ye Rubin; Kagohashi, Tsutomu; Zheng Wei

    2009-01-01

    Polyethylene insulated electric wire was treated in He and Ar dielectric barrier discharge atmospheric pressure plasmas generated in a quartz tube wound with tubular electrodes. The wire was put penetrating through the high voltage and the grounded electrodes, improving the discharge and facilitating uniform surface treatment. In this work, the influences of conductivity of the wire on the effects of surface treatment and discharge behavior were investigated. Surface properties of the wire samples were analyzed by means of surface energy measurement and X-ray photoelectron spectroscopy. In order to reveal the mechanism for treating the conductive wire, I-V discharge waveforms were measured and time-resolved plasma images were taken. It was demonstrated that the conductive wire was involved in the discharge process, reducing the breakdown voltage significantly and enhancing the discharge. It shows that the discharge mode was strongly dependent on the conductivity of a wire. Intensive surface discharges developed along the conductive wire were found to be mainly responsible for noticeable improvement in the treatment effect.

  2. Electrically continuous graphene from single crystal copper verified by terahertz conductance spectroscopy and micro four-point probe

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due; Pizzocchero, Filippo; Jessen, Bjarke Sørensen

    2014-01-01

    The electrical performance of graphene synthesized by chemical vapor deposition and transferred to insulating surfaces may be compromised by extended defects, including for instance grain boundaries, cracks, wrinkles, and tears. In this study, we experimentally investigate and compare the nano......- and microscale electrical continuity of single layer graphene grown on centimeter-sized single crystal copper with that of previously studied graphene films, grown on commercially available copper foil, after transfer to SiO2 surfaces. The electrical continuity of the graphene films is analyzed using two...... for measurement of the complex conductance response in the frequency range 1-15 terahertz, covering the entire intraband conductance spectrum, and reveals that the conductance response for the graphene grown on single crystalline copper intimately follows the Drude model for a barrier-free conductor. In contrast...

  3. Fully coupled heat conduction and deformation analyses of visco-elastic solids

    KAUST Repository

    Khan, Kamran

    2012-04-21

    Visco-elastic materials are known for their capability of dissipating energy. This energy is converted into heat and thus changes the temperature of the materials. In addition to the dissipation effect, an external thermal stimulus can also alter the temperature in a viscoelastic body. The rate of stress relaxation (or the rate of creep) and the mechanical and physical properties of visco-elastic materials, such as polymers, vary with temperature. This study aims at understanding the effect of coupling between the thermal and mechanical response that is attributed to the dissipation of energy, heat conduction, and temperature-dependent material parameters on the overall response of visco-elastic solids. The non-linearly viscoelastic constitutive model proposed by Schapery (Further development of a thermodynamic constitutive theory: stress formulation, 1969,Mech. Time-Depend. Mater. 1:209-240, 1997) is used and modified to incorporate temperature- and stress-dependent material properties. This study also formulates a non-linear energy equation along with a dissipation function based on the Gibbs potential of Schapery (Mech. Time-Depend. Mater. 1:209-240, 1997). A numerical algorithm is formulated for analyzing a fully coupled thermo-visco-elastic response and implemented it in a general finite-element (FE) code. The non-linear stress- and temperature-dependent material parameters are found to have significant effects on the coupled thermo-visco-elastic response of polymers considered in this study. In order to obtain a realistic temperature field within the polymer visco-elastic bodies undergoing a non-uniform heat generation, the role of heat conduction cannot be ignored. © Springer Science+Business Media, B. V. 2012.

  4. Non-response weighting adjustment approach in survey sampling ...

    African Journals Online (AJOL)

    Hence the discussion is illustrated with real examples from surveys (in particular 2003 KDHS) conducted by Central Bureau of Statistics (CBS) - Kenya. Some suggestions are made for improving the quality of non-response weighting. Keywords: Survey non-response; non-response adjustment factors; weighting; sampling ...

  5. The electrical conductivity of the Earth's upper mantle as estimated from satellite measured magnetic field variations. Ph.D. Thesis

    Science.gov (United States)

    Didwall, E. M.

    1981-01-01

    Low latitude magnetic field variations (magnetic storms) caused by large fluctuations in the equatorial ring current were derived from magnetic field magnitude data obtained by OGO 2, 4, and 6 satellites over an almost 5 year period. Analysis procedures consisted of (1) separating the disturbance field into internal and external parts relative to the surface of the Earth; (2) estimating the response function which related to the internally generated magnetic field variations to the external variations due to the ring current; and (3) interpreting the estimated response function using theoretical response functions for known conductivity profiles. Special consideration is given to possible ocean effects. A temperature profile is proposed using conductivity temperature data for single crystal olivine. The resulting temperature profile is reasonable for depths below 150-200 km, but is too high for shallower depths. Apparently, conductivity is not controlled solely by olivine at shallow depths.

  6. Actions of rilmenidine on neurogenic hypertension in BPH/2J genetically hypertensive mice.

    Science.gov (United States)

    Jackson, Kristy L; Palma-Rigo, Kesia; Nguyen-Huu, Thu-Phuc; Davern, Pamela J; Head, Geoffrey A

    2014-03-01

    BPH/2J hypertensive mice have an exaggerated sympathetic contribution to blood pressure (BP). Premotor sympathetic neurons within the rostroventrolateral medulla (RVLM) are a major source of sympathetic vasomotor tone and major site of action of the centrally acting sympatholytic agent, rilmenidine. The relative cardiovascular effect of rilmenidine in BPH/2J versus normotensive BPN/3J mice was used as an indicator of the involvement of the RVLM in the sympathetic contribution to hypertension in BPH/2J mice. BPH/2J and BPN/3J mice were pre-implanted with telemetry devices to measure BP in conscious unrestrained mice. Rilmenidine was administered acutely (n=7-9/group), orally for 14 days, at a wide range of doses (n=5/group), and also infused intracerebroventricularly for 7 days (n=6/group). Acute intraperitoneal rilmenidine induced greater depressor and bradycardic responses in BPH/2J than BPN/3J mice (PstrainBPH/2J mice during the dark (active) period (-6.5 ± 2 mmHg; P=0.006). Chronic orally administered rilmenidine (1-12 mg/kg per day) also had minimal effect on 24-h BP in both strains (P>0.16). The sympathetic vasomotor inhibitory effect of rilmenidine is minimal in both strains and similar in hypertensive BPH/2J and BPN/3J mice. Thus, hypertension in BPH/2J mice is not likely mediated by greater neuronal activity in the RVLM, and agents such as rilmenidine would be an ineffective treatment for this form of neurogenic hypertension.

  7. Conducting compositions of matter

    Science.gov (United States)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  8. Electrically conductive material

    Science.gov (United States)

    Singh, J.P.; Bosak, A.L.; McPheeters, C.C.; Dees, D.W.

    1993-09-07

    An electrically conductive material is described for use in solid oxide fuel cells, electrochemical sensors for combustion exhaust, and various other applications possesses increased fracture toughness over available materials, while affording the same electrical conductivity. One embodiment of the sintered electrically conductive material consists essentially of cubic ZrO[sub 2] as a matrix and 6-19 wt. % monoclinic ZrO[sub 2] formed from particles having an average size equal to or greater than about 0.23 microns. Another embodiment of the electrically conductive material consists essentially at cubic ZrO[sub 2] as a matrix and 10-30 wt. % partially stabilized zirconia (PSZ) formed from particles having an average size of approximately 3 microns. 8 figures.

  9. “Inflammatory Soup” Mediators of inflammation in CRPS

    NARCIS (Netherlands)

    F. Wesseldijk (Feikje)

    2008-01-01

    textabstractComplex Regional Pain Syndrome type 1 (CRPS1) is a disease of the extremity that usually occurs as a complication after surgery or trauma, although spontaneous occurrence has also been described. The clinical features include pain/sensory abnormalities, vasomotor dysfunction,

  10. Managing Depression during the Menopausal Transition

    Science.gov (United States)

    Pearson, Quinn M.

    2010-01-01

    The menopausal transition is associated with both first onset of depression and recurrent depression. Risk factors include vasomotor symptoms, a history of premenstrual dysphoria, postpartum depression, major depression, and sleep disturbances. Hormone replacement therapy, complementary and alternative medicine approaches, and counseling…

  11. Tibolone and low-dose continuous combined hormone treatment : vaginal bleeding pattern, efficacy and tolerability

    NARCIS (Netherlands)

    Hammar, M. L.; van de Weijer, P.; Franke, H. R.; Pornel, B.; von Mauw, E. M. J.; Nijland, E. A.

    2007-01-01

    Objectives The primary objective was to compare the vaginal bleeding pattern during administration of tibolone and low-dose continuous combined estradiol plus norethisterone acetate (E-2/NETA). The secondary objectives were efficacy on vasomotor symptoms and vaginal atrophy. Design A randomised,

  12. Endothelial dysfunction in normal and prediabetic rats with metabolic syndrome exposed by oral gavage to carbon black nanoparticles

    DEFF Research Database (Denmark)

    Folkmann, Janne Kjærsgaard; Vesterdal, Lise Kristine; Sheykhzade, Majid

    2012-01-01

    Exposure to nanosized particles may increase the risk of cardiovascular diseases by endothelial dysfunction, particularly in susceptible subjects with metabolic syndrome. We investigated vasomotor dysfunction in aorta from obese and lean Zucker rats after oral exposure to nanosized carbon black (...

  13. Assessing menopausal status in women aged 40 - 49 using depot ...

    African Journals Online (AJOL)

    Background. Determining symptoms of menopause in older users of hormonal injectable contraceptives may be challenging, owing to method-induced amenorrhoea, suppression of follicle-stimulating hormone (FSH) and vasomotor symptoms. Objective. To investigate menopausal symptoms in women aged 40 - 49 using ...

  14. Autonomic control of vasomotion in the porcine coronary circulation during treadmill exercise: evidence for feed-forward beta-adrenergic control

    NARCIS (Netherlands)

    D.J.G.M. Duncker (Dirk); R. Stubenitsky (René); P.D. Verdouw (Pieter)

    1998-01-01

    textabstractTo date, no studies have investigated coronary vasomotor control of myocardial O2 delivery (MDO2) and its modulation by the autonomic nervous system in the porcine heart during treadmill exercise. We studied 8 chronically instrumented swine under resting

  15. Low power digital communication in implantable devices using volume conduction of biological tissues.

    Science.gov (United States)

    Yao, Ning; Lee, Heung-No; Sclabassi, R J; Sun, Mingui

    2006-01-01

    This work investigates the data communication problem of implantable devices using fundamental theories in communications. We utilize the volume conduction property of biological tissues to establish a digital communications link. Data obtained through animal experiments are used to analyze the time and frequency response of the volume conduction channel as well as to characterize the biological signals and noises present in the system. A low power bandwidth efficient channel-coded modulation scheme is proposed to conserve battery power and reduce the health risks associated.

  16. Temp erature-dep endent of Nonlinear Optical Conductance of Graphene-based Systems in High-intensity Terahertz Field

    Institute of Scientific and Technical Information of China (English)

    Jing Lv; Rui-yang Yuan; Hui Yan

    2014-01-01

    For multi-photon processed with the linear dispersion in the high-intensity terahertz (THz) field, we have systematically investigated the temperature-dependent nonlinear optical response of graphene-based systems, including single layer graphene, graphene superlattice and gapped graphene. In the intrinsic single layer graphene system, it demonstrates that, at low temperature, nonlinear optical conductivities of the third-and fifth-order are respectively five and ten orders of magnitude larger than the universal conductivity with high-intensity and low frequency THz wave.In the graphene superlattice and gapped graphene systems, the optical responses enhanced because of the anisotropic massless and massive Dirac fermions.

  17. Conductivity and dielectric behaviour of indium substituted zinc ferrites prepared by coprecipitation method

    International Nuclear Information System (INIS)

    Cvejić, Željka; Rakić, Srđan; Jankov, Stevan; Skuban, Sonja; Rapajić, Sanja; Srdić, Vladimir V

    2015-01-01

    This paper presents the results concerning dielectric behavior and conductivity of the nanosized Zn 1−x In x Fe 2 O 4 powders (x = 0, 0.15, 0.2, and 0.3), obtained by coprecipitation method. The frequency dependence of dielectric permittivity and conductivity of the samples is determined in the frequency range of 1–10 5 Hz, at temperatures from 300–350 K, while the temperature dependence of conductivity was recorded at 100 Hz, 10 kHz and 100 kHz. The ac conductivity was found to follow universal dielectric response, which is typical for charge transport by hopping or tunneling processes. Analyzing the variation of the parameter n (as a measure of the degree of correlation between conductivity and frequency), with the temperatures we discuss the possible conduction mechanism in investigated samples. Qualitatively, non-overlapping small polarons (NSPT) are usually associated with increase in n with increasing temperature, while correlated barrier hopping (CBH) shows a decrease in n with increasing T. (paper)

  18. Joint inversion of multi-configuration electromagnetic induction data to characterize subsurface electrical conductivity

    KAUST Repository

    Jadoon, Khan

    2012-01-01

    Electromagnetic induction (EMI) devices are capable of measuring the cumulative electrical conductivity over a certain depth range. In this study, a numerical experiment has been performed to test a novel join inversion approach for the Geonics EM34 instrument, by considering different coil offsets (10, 20 and 40 m), different coil orientations (vertical and horizontal), and different frequencies (6.4, 1.6 and 0.4 kHz). The subsurface is considered as four-layer model having different conductivities. The global multilevel coordinate search optimization algorithm is sequentially combination with the local optimization algorithm to minimize the misfit between the measured and modeled data. The layer conductivities are well predicted by the join inversion of electromagnetic data. The response surface of the objective function was investigated to assess the sensitivity of the subsurface layer conductivities. The sensitivity of the conductivity for the top two layers is less as compared to the deeper layers. The proposed approach is promising for the fast mapping of true conductivity distributions over large areas.

  19. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, D. [Department of Physics, Amrita Viswha Vidyapeetham, Bangalore, India, E-mail: d-praveen@blr.amrita.edu (India); Damle, Ramakrishna [Department of Physics, Bangalore University, Bangalore, India. E-mail: ramkrishnadamle@bub.ernet.in (India)

    2016-05-23

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO{sub 4}){sub 2}, NH{sub 4}I etc., have already been tried in the past with some success. Also various nanoparticles like Al{sub 2}O{sub 3}, TiO{sub 2} etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

  20. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    International Nuclear Information System (INIS)

    Praveen, D.; Damle, Ramakrishna

    2016-01-01

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO_4)_2, NH_4I etc., have already been tried in the past with some success. Also various nanoparticles like Al_2O_3, TiO_2 etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.