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Sample records for twitch potentiation dithiothreitol

  1. Heterogeneous oxidation of SO2 by O3-aged black carbon and its dithiothreitol oxidative potential.

    Science.gov (United States)

    Xu, Weiwei; Li, Qian; Shang, Jing; Liu, Jia; Feng, Xiang; Zhu, Tong

    2015-10-01

    Ozone (O3) is an important atmospheric oxidant. Black carbon (BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reducing gases such as SO2 in the atmosphere, leading to different environmental and health effects. In this paper, the heterogeneous reaction process between O3-aged BC and SO2 was explored via in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Combined with ion chromatography (IC), DRIFTS was used to qualitatively and quantitatively analyze the sulfate product. The results showed that O3-aged BC had stronger SO2 oxidation ability than fresh BC, and the reactive species/sites generated on the surface had an important role in the oxidation of SO2. Relative humidity or 254nm UV (ultraviolet) light illumination enhanced the oxidation uptake of SO2 on O3-aged BC. The oxidation potentials of the BC particles were detected via dithiothreitol (DTT) assay. The DTT activity over BC was decreased in the process of SO2 reduction, with the consumption of oxidative active sites. Copyright © 2015. Published by Elsevier B.V.

  2. Recovery of Action Potentials and Twitches after K-contractures in Frog Skeletal Muscle(Physiology)

    OpenAIRE

    Atsuko, Suzuki; Ibuki, Shirakawa; Kazunari, Noguchi; Hirohiko, Kishi; Haruo, Sugi; Department of Physiology, School of Medicine, Teikyo University:(Present office)Department of Physical Therapy, Health Science University; Department of Physiology, School of Medicine, Teikyo University; Department of Physiology, School of Medicine, Teikyo University; Department of Physiology, School of Medicine, Teikyo University; Department of Physiology, School of Medicine, Teikyo University

    2004-01-01

    To give information about intracellular Ca^ translocation during and after K-contractures in vertebrate skeletal muscle fibers, we examined recovery of action potentials and twitches after interruption and spontaneous relaxation of K-contractures at low temperature (3℃) that greatly reduced the rate of Ca^ reuptake by the sarcoplasmic reticulum. On membrane repolarization interrupting K-contractures, the amplitude of both action potentials and twitches recovered quickly, while the falling pha...

  3. Sarcomere length-dependence of activity-dependent twitch potentiation in mouse skeletal muscle

    Directory of Open Access Journals (Sweden)

    MacIntosh Brian R

    2002-12-01

    Full Text Available Abstract Background It has been reported that potentiation of a skeletal muscle twitch response is proportional to muscle length with a negative slope during staircase, and a positive slope during posttetanic potentiation. This study was done to directly compare staircase and posttetanic responses with measurement of sarcomere length to compare their length-dependence. Methods Mouse extensor digitorum longus (EDL muscles were dissected to small bundles of fibers, which permit measurement of sarcomere length (SL, by laser diffraction. In vitro fixed-end contractions of EDL fiber bundles were elicited at 22°C and 35°C at sarcomere lengths ranging from 2.35 μm to 3.85 μm. Twitch contractions were assessed before and after 1.5 s of 75 Hz stimulation at 22°C or during 10 s of 10 Hz stimulation at 22°C or 35°C. Results Staircase potentiation was greater at 35°C than 22°C, and the relative magnitude of the twitch contraction (Pt*/Pt was proportional to sarcomere length with a negative slope, over the range 2.3 μm – 3.7 μm. Linear regression yielded the following: Pt*/Pt = -0.59·SL+3.27 (r2 = 0.74; Pt*/Pt = -0.39·SL+2.34 (r2 = 0.48; and Pt*/Pt = -0.50·SL+2.45 (r2 = 0.80 for staircase at 35°C, and 22°C and posttetanic response respectively. Posttetanic depression rather than potentiation was present at long SL. This indicates that there may be two processes operating in these muscles to modulate the force: one that enhances and a second that depresses the force. Either or both of these processes may have a length-dependence of its mechanism. Conclusion There is no evidence that posttetanic potentiation is fundamentally different from staircase in these muscles.

  4. On dithiothreitol (DTT as a measure of oxidative potential for ambient particles: evidence for the importance of soluble ewline transition metals

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    J. G. Charrier

    2012-10-01

    Full Text Available The rate of consumption of dithiothreitol (DTT is increasingly used to measure the oxidative potential of particulate matter (PM, which has been linked to the adverse health effects of PM. While several quinones are known to be very reactive in the DTT assay, it is unclear what other chemical species might contribute to the loss of DTT in PM extracts. To address this question, we quantify the rate of DTT loss from individual redox-active species that are common in ambient particulate matter. While most past research has indicated that the DTT assay is not sensitive to metals, our results show that seven out of the ten transition metals tested do oxidize DTT, as do three out of the five quinones tested. While metals are less efficient at oxidizing DTT compared to the most reactive quinones, concentrations of soluble transition metals in fine particulate matter are generally much higher than those of quinones. The net result is that metals appear to dominate the DTT response for typical ambient PM2.5 samples. Based on particulate concentrations of quinones and soluble metals from the literature, and our measured DTT responses for these species, we estimate that for typical PM2.5 samples approximately 80% of DTT loss is from transition metals (especially copper and manganese, while quinones account for approximately 20%. We find a similar result for DTT loss measured in a small set of PM2.5 samples from the San Joaquin Valley of California. Because of the important contribution from metals, we also tested how the DTT assay is affected by EDTA, a chelator that is sometimes used in the assay. EDTA significantly suppresses the response from both metals and quinones; we therefore recommend that EDTA should not be included in the DTT assay.

  5. Time-related changes in firing rates are influenced by recruitment threshold and twitch force potentiation in the first dorsal interosseous.

    Science.gov (United States)

    Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Sterczala, Adam J; Ciccone, Anthony B

    2017-08-01

    What is the central question of this study? The influences of motor unit recruitment threshold and twitch force potentiation on the changes in firing rates during steady-force muscular contractions are not well understood. What is the main finding and its importance? The behaviour of motor units during steady force was influenced by recruitment threshold, such that firing rates decreased for lower-threshold motor units but increased for higher-threshold motor units. In addition, individuals with greater changes in firing rates possessed greater twitch force potentiation. There are contradictory reports regarding changes in motor unit firing rates during steady-force contractions. Inconsistencies are likely to be the result of previous studies disregarding motor unit recruitment thresholds and not examining firing rates on a subject-by-subject basis. It is hypothesized that firing rates are manipulated by twitch force potentiation during contractions. Therefore, in this study we examined time-related changes in firing rates at steady force in relationship to motor unit recruitment threshold in the first dorsal interosseous and the influence of twitch force potentiation on such changes in young versus aged individuals. Subjects performed a 12 s steady-force contraction at 50% maximal voluntary contraction, with evoked twitches before and after the contraction to quantify potentiation. Firing rates, in relationship to recruitment thresholds, were determined at the beginning, middle and end of the steady force. There were no firing rate changes for aged individuals. For the young, firing rates decreased slightly for lower-threshold motor units but increased for higher-threshold motor units. Twitch force potentiation was greater for young than aged subjects, and changes in firing rates were correlated with twitch force potentiation. Thus, individuals with greater increases in firing rates of higher-threshold motor units and decreases in lower-threshold motor units

  6. β2-Adrenergic Receptor Activation Suppresses the Rat Phenethylamine Hallucinogen-Induced Head Twitch Response: Hallucinogen-Induced Excitatory Post-synaptic Potentials as a Potential Substrate

    Science.gov (United States)

    Marek, Gerard J.; Ramos, Brian P.

    2018-01-01

    5-Hydroxytryptamine2A (5-HT2A) receptors are enriched in layers I and Va of the rat prefrontal cortex and neocortex and their activation increases the frequency of glutamatergic excitatory post-synaptic potentials/currents (EPSP/Cs) onto layer V pyramidal cells. A number of other G-protein coupled receptors (GPCRs) are also enriched in cortical layers I and Va and either induce (α1-adrenergic and orexin2) or suppress (metabotropic glutamate2 [mGlu2], adenosine A1, μ-opioid) both 5-HT-induced EPSCs and head twitches or head shakes induced by the phenethylamine hallucinogen 2,5-dimethoxy-4-iodoamphetamine (DOI). Another neurotransmitter receptor also localized to apparent thalamocortical afferents to layers I and Va of the rat prefrontal cortex and neocortex is the β2-adrenergic receptor. Therefore, we conducted preliminary electrophysiological experiments with rat brain slices examining the effects of epinephrine on electrically-evoked EPSPs following bath application of DOI (3 μM). Epinephrine (0.3–10 μM) suppressed the late EPSPs produced by electrical stimulation and DOI. The selective β2-adrenergic receptor antagonist ICI-118,551 (300 nM) resulted in a rightward shift of the epinephrine concentration-response relationship. We also tested the selective β2-adrenergic receptor agonist clenbuterol and the antagonist ICI-118,551 on DOI-induced head twitches. Clenbuterol (0.3–3 mg/kg, i.p.) suppressed DOI (1.25 mg/kg, i.p.)-induced head twitches. This clenbuterol effect appeared to be at least partially reversed by the selective β2-adrenergic receptor antagonist ICI-118,553 (0.01–1 mg/kg, i.p.), with significant reversal at doses of 0.1 and 1 mg/kg. Thus, β2-adrenergic receptor activation reverses the effects of phenethylamine hallucinogens in the rat prefrontal cortex. While Gi/Go-coupled GPCRs have previously been shown to suppress both the electrophysiological and behavioral effects of 5-HT2A receptor activation in the mPFC, the present work appears

  7. Oxidative potential of ambient water-soluble PM2.5 in the southeastern United States: contrasts in sources and health associations between ascorbic acid (AA and dithiothreitol (DTT assays

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    T. Fang

    2016-03-01

    Full Text Available The ability of certain components of particulate matter to induce oxidative stress through the generation of reactive oxygen species (ROS in vivo may be one mechanism accounting for observed linkages between ambient aerosols and adverse health outcomes. A variety of assays have been used to measure this so-called aerosol oxidative potential. We developed a semi-automated system to quantify oxidative potential of filter aqueous extracts utilizing the dithiothreitol (DTT assay and report here the development of a similar semi-automated system for the ascorbic acid (AA assay. Approximately 500 PM2.5 filter samples collected in contrasting locations in the southeastern US were analyzed for a host of aerosol species, along with AA and DTT activities. We present a detailed contrast in findings from these two assays. Water-soluble AA activity was higher in summer and fall than in winter, with highest levels near heavily trafficked highways, whereas DTT activity was higher in winter compared to summer and fall and more spatially homogeneous. AA activity was nearly exclusively correlated with water-soluble Cu (r  =  0.70–0.94 at most sites, whereas DTT activity was correlated with organic and metal species. Source apportionment models, positive matrix factorization (PMF and a chemical mass balance method with ensemble-averaged source impact profiles (CMB-E, suggest a strong contribution from traffic emissions and secondary processes (e.g., organic aerosol oxidation or metals mobilization by secondary acids to both AA and DTT activities in urban Atlanta. In contrast, biomass burning was a large source for DTT activity, but insignificant for AA. AA activity was not correlated with PM2.5 mass, while DTT activity co-varied strongly with mass (r  =  0.49–0.86 across sites and seasons. Various linear models were developed to estimate AA and DTT activities for the central Atlanta Jefferson Street site, based on the CMB-E sources. The

  8. Sarcoplasmic reticulum calcium release compared in slow-twitch and fast-twitch fibres of mouse muscle.

    Science.gov (United States)

    Baylor, S M; Hollingworth, S

    2003-08-15

    Experiments were carried out to compare the amplitude and time course of Ca2+ release from the sarcoplasmic reticulum (SR) in intact slow-twitch and fast-twitch mouse fibres. Individual fibres within small bundles were injected with furaptra, a low-affinity, rapidly responding Ca2+ indicator. In response to a single action potential at 16 degrees C, the peak amplitude and half-duration of the change in myoplasmic free [Ca2+] (Delta[Ca2+]) differed significantly between fibre types (slow-twitch: peak amplitude, 9.4 +/- 1.0 microM (mean +/- S.E.M.); half-duration, 7.7 +/- 0.6 ms; fast-twitch: peak amplitude 18.5 +/- 0.5 microM; half-duration, 4.9 +/- 0.3 ms). SR Ca2+ release was estimated from Delta[Ca2+] with a computational model that calculated Ca2+ binding to the major myoplasmic Ca2+ buffers (troponin, ATP and parvalbumin); buffer concentrations and reaction rate constants were adjusted to reflect fibre-type differences. In response to an action potential, the total concentration of released Ca2+ (Delta[CaT]) and the peak rate of Ca2+ release ((d/dt)Delta[CaT]) differed about 3-fold between the fibre types (slow-twitch: Delta[CaT], 127 +/- 7 microM; (d/dt)Delta[CaT], 70 +/- 6 microM ms-1; fast-twitch: Delta[CaT], 346 +/- 6 microM; (d/dt)Delta[CaT], 212 +/- 4 microM ms-1). In contrast, the half-duration of (d/dt)Delta[CaT] was very similar in the two fibre types (slow-twitch, 1.8 +/- 0.1 ms; fast-twitch, 1.6 +/- 0.0 ms). When fibres were stimulated with a 5-shock train at 67 Hz, the peaks of (d/dt)Delta[CaT] in response to the second and subsequent shocks were much smaller than that due to the first shock; the later peaks, expressed as a fraction of the amplitude of the first peak, were similar in the two fibre types (slow-twitch, 0.2-0.3; fast-twitch, 0.1-0.3). The results support the conclusion that individual SR Ca2+ release units function similarly in slow-twitch and fast-twitch mammalian fibres.

  9. Dithiothreitol-based protein equalization technology to unravel biomarkers for bladder cancer.

    Science.gov (United States)

    Araújo, J E; López-Fernández, H; Diniz, M S; Baltazar, Pedro M; Pinheiro, Luís Campos; da Silva, Fernando Calais; Carrascal, Mylène; Videira, Paula; Santos, H M; Capelo, J L

    2018-04-01

    This study aimed to assess the benefits of dithiothreitol (DTT)-based sample treatment for protein equalization to assess potential biomarkers for bladder cancer. The proteome of plasma samples of patients with bladder carcinoma, patients with lower urinary tract symptoms (LUTS) and healthy volunteers, was equalized with dithiothreitol (DTT) and compared. The equalized proteomes were interrogated using two-dimensional gel electrophoresis and matrix assisted laser desorption ionization time of flight mass spectrometry. Six proteins, namely serum albumin, gelsolin, fibrinogen gamma chain, Ig alpha-1 chain C region, Ig alpha-2 chain C region and haptoglobin, were found dysregulated in at least 70% of bladder cancer patients when compared with a pool of healthy individuals. One protein, serum albumin, was found overexpressed in 70% of the patients when the equalized proteome of the healthy pool was compared with the equalized proteome of the LUTS patients. The pathways modified by the proteins differentially expressed were analyzed using Cytoscape. The method here presented is fast, cheap, of easy application and it matches the analytical minimalism rules as outlined by Halls. Orthogonal validation was done using western-blot. Overall, DTT-based protein equalization is a promising methodology in bladder cancer research. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The effects of beta-adrenoceptor activation on contraction in isolated fast- and slow-twitch skeletal muscle fibres of the rat.

    OpenAIRE

    Cairns, S. P.; Dulhunty, A. F.

    1993-01-01

    1. The aim of the experiments was to examined the effects of beta-adrenoceptor activation on twitch and tetanic contractions in fast- and slow-twitch mammalian skeletal muscle fibres. Isometric force was recorded from bundles of intact fibres isolated from the normal and denervated slow-twitch soleus and normal fast-twitch sternomastoid muscles of the rat. 2. Terbutaline (10 microM), a beta 2-adrenoceptor agonist, induced an average 15% potentiation of peak twitch and peak tetanic force in no...

  11. Toxicity of the sulfhydryl-containing radioprotector dithiothreitol

    International Nuclear Information System (INIS)

    Held, K.D.; Biaglow, J.E.

    1987-01-01

    The toxicity of the sulfhydryl-containing radioprotector dithiothreitol (DTT) has been studied in Chinese hamster V79 cells growing in monolayer. Under the conditions used here DTT causes a biphasic toxic response in which low concentrations of the drug (0.5 to 1.0 mM) are more toxic than are lower (0.2 mM) or higher (10 mM) concentrations. This response is similar to that seen by others with other sulfhydryl compounds. This DTT-induced toxicity is prevented by catalase, glutathione, and lowered temperatures. The toxicity is enhanced by some metal chelators (EDTA) but prevented by others (desferal). Metals (copper and iron) can either enhance or decrease the toxicity depending on their concentration and whether the exposure is in medium or in buffered salt solution. The results suggest a complex chain of chemical reactions and interactions with a role of H/sub 2/O/sub 2/ and perhaps . OH in this DTT toxicity. This is discussed

  12. Dietary nitrate increases tetanic [Ca2+]i and contractile force in mouse fast-twitch muscle.

    Science.gov (United States)

    Hernández, Andrés; Schiffer, Tomas A; Ivarsson, Niklas; Cheng, Arthur J; Bruton, Joseph D; Lundberg, Jon O; Weitzberg, Eddie; Westerblad, Håkan

    2012-08-01

    Dietary inorganic nitrate has profound effects on health and physiological responses to exercise. Here, we examined if nitrate, in doses readily achievable via a normal diet, could improve Ca(2+) handling and contractile function using fast- and slow-twitch skeletal muscles from C57bl/6 male mice given 1 mm sodium nitrate in water for 7 days. Age matched controls were provided water without added nitrate. In fast-twitch muscle fibres dissected from nitrate treated mice, myoplasmic free [Ca(2+)] was significantly greater than in Control fibres at stimulation frequencies from 20 to 150 Hz, which resulted in a major increase in contractile force at ≤ 50 Hz. At 100 Hz stimulation, the rate of force development was ∼35% faster in the nitrate group. These changes in nitrate treated mice were accompanied by increased expression of the Ca(2+) handling proteins calsequestrin 1 and the dihydropyridine receptor. No changes in force or calsequestrin 1 and dihydropyridine receptor expression were measured in slow-twitch muscles. In conclusion, these results show a striking effect of nitrate supplementation on intracellular Ca(2+) handling in fast-twitch muscle resulting in increased force production. A new mechanism is revealed by which nitrate can exert effects on muscle function with applications to performance and a potential therapeutic role in conditions with muscle weakness.

  13. Age-related differences in twitch properties and muscle activation of the first dorsal interosseous.

    Science.gov (United States)

    Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Sterczala, Adam J; Ciccone, Anthony B; Nicoll, Justin X

    2017-06-01

    To examine twitch force potentiation and twitch contraction duration, as well as electromyographic amplitude (EMG RMS ) and motor unit mean firing rates (MFR) at targeted forces between young and old individuals in the first dorsal interosseous (FDI). Ultrasonography was used to assess muscle quality. Twenty-two young (YG) (age=22.6±2.7years) and 14 older (OD) (age=62.1±4.7years) individuals completed conditioning contractions at 10% and 50% maximal voluntary contraction, (MVC) during which EMG RMS and MFRs were assessed. Evoked twitches preceded and followed the conditioning contractions. Ultrasound images were taken to quantify muscle quality (cross-sectional area [CSA] and echo intensity [EI]). No differences were found between young and old for CSA, pre-conditioning contraction twitch force, or MFRs (P>0.05). However, OD individuals exhibited greater EI and contraction duration (PMFRs. Ultrasonography suggested age-related changes in muscle structure contributed to altered contractile properties in the OD. Greater muscle activation requirements can have negative implications on fatigue resistance at low to moderate intensities in older individuals. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  14. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Directory of Open Access Journals (Sweden)

    H. Jiang

    2017-08-01

    Full Text Available When hydrocarbons (HCs are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs. These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t =  30 min of dithiothreitol (DTTt, a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2–5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC ∕ NOx ratio from 30 to 5. The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm was determined over an extended period of reaction time (t =  2 h to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC ∕ NOx ratio: 5–36 ppbC ppb−1 applied in

  15. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Yu, Zechen

    2017-08-01

    When hydrocarbons (HCs) are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs). These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes) and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs) to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t = 30 min) of dithiothreitol (DTTt), a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2-5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC / NOx ratio from 30 to 5). The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm) was determined over an extended period of reaction time (t = 2 h) to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC / NOx ratio: 5-36 ppbC ppb-1) applied in this study, the amount of organic hydroperoxides was

  16. The protective effect of hypoxia and dithiothreitol on X-ray-induced genetic damage in Arabidopsis

    International Nuclear Information System (INIS)

    Sree Ramulu, K.; Veen, J.H. van der

    1987-01-01

    A study was made on the protective effect of hypoxia and dithiothreitol (DTT) on X-ray-induced ovule sterility and embryonic lethality in Arabidopsis. Both hypoxia and DTT gave a pronounced and additive reduction of radiation-induced genetic damage. The reduction was significantly higher for ovule sterility than for embryonic lethals. It is suggested that non-fertilized ovules contain a higher ratio of strand breaks/other damage than embryonic lethals do, for hypoxia and DTT are known specifically to give a reduction of strand breaks. (Auth.)

  17. Hydrogen peroxide modulates Ca2+-activation of single permeabilized fibres from fast- and slow-twitch skeletal muscles of rats.

    Science.gov (United States)

    Plant, D R; Lynch, G S; Williams, D A

    2000-01-01

    We examined the effects of redox modulation on single membrane-permeabilized fibre segments from the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of adult rats to determine whether the contractile apparatus was the redox target responsible for the increased contractility of muscles exposed to low concentrations of H2O2. The effects of H2O2 on maximum Ca2+-activated force were dose-dependent with 30 min exposure to 5 mM H2O2 causing a progressive decrease by 22+/-3 and 13+/-2% in soleus and EDL permeabilized muscle fibres, respectively. Lower concentrations of exogenous H2O2 (100 microM and 1 mM) had no effect on maximum Ca2+-activated force. Subsequent exposure to the reductant dithiothreitol (DTT, 10 mM, 10 min) fully reversed the H2O2-induced depression of force in EDL, but not in soleus muscle fibres. Incubation with DTT alone for 10 min did not alter Ca2+-activated force in either soleus or EDL muscle fibres. The sensitivity of the contractile filaments to Ca2+ (pCa50) was not altered by exposure to any concentration of exogenous H2O2. However, all concentrations of H2O2 diminished the Hill coefficient in permeabilized fibres from the EDL muscle, indicating that the cooperativity of Ca2+ binding to troponin is altered. H2O2 (5 mM) did not affect rigor force, which indicates that the number of crossbridges participating in contraction was not reduced. In conclusion, H2O2 may reduce the maximum Ca2+ activated force production in skinned muscle fibres by decreasing the force per crossbridge.

  18. Twitching in sensorimotor development from sleeping rats to robots.

    Science.gov (United States)

    Blumberg, Mark S; Marques, Hugo Gravato; Iida, Fumiya

    2013-06-17

    It is still not known how the 'rudimentary' movements of fetuses and infants are transformed into the coordinated, flexible and adaptive movements of adults. In addressing this important issue, we consider a behavior that has been perennially viewed as a functionless by-product of a dreaming brain: the jerky limb movements called myoclonic twitches. Recent work has identified the neural mechanisms that produce twitching as well as those that convey sensory feedback from twitching limbs to the spinal cord and brain. In turn, these mechanistic insights have helped inspire new ideas about the functional roles that twitching might play in the self-organization of spinal and supraspinal sensorimotor circuits. Striking support for these ideas is coming from the field of developmental robotics: when twitches are mimicked in robot models of the musculoskeletal system, the basic neural circuitry undergoes self-organization. Mutually inspired biological and synthetic approaches promise not only to produce better robots, but also to solve fundamental problems concerning the developmental origins of sensorimotor maps in the spinal cord and brain. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Determination of protein by resonance light scattering technique using dithiothreitol-sodium dodecylbenzene sulphonate as probe

    Science.gov (United States)

    Wu, Lihang; Mu, Dan; Gao, Dejiang; Deng, Xinyu; Tian, Yuan; Zhang, Hanqi; Yu, Aimin

    2009-02-01

    The resonance light scattering (RLS) spectra of bovine serum albumin (BSA)-dithiothreitol (DTT)-sodium dodecylbenzene sulphonate (SDBS) and its analytical application were investigated. The RLS intensity of this system can be effectively enhanced in the presence of BSA. Based on the enhanced RLS intensity, a simple assay for BSA was developed. The experimental results indicate that the enhanced RLS intensity is proportional to the concentration of BSA in the range from 1.0 × 10 -8 to 7.5 × 10 -7 mol L -1 with the determination limit of 5.0 × 10 -9 mol L -1. The effects of pH, concentration of SDBS and DTT on the RLS enhancement were discussed. Most metal ions have little interference on the determination of BSA. Some synthetic and real samples were analyzed, and the results obtained were in good agreement with those obtained by Bradford method.

  20. Characterization of a half-molecular fragment obtained by reduction of human α2-macroglobulin with dithiothreitol

    DEFF Research Database (Denmark)

    Sjöberg, B.; Pap, S.; Kjems, Jørgen

    1985-01-01

    A half-molecular fragment of α2-macroglobulin has been prepared by reducing and alkylating the inter-subunit disulfide bonds in the tetrameric α2-macroglobulin molecule with 1 mM dithiothreitol (40 min) and 3 mM iodoacetamide (40 min). Further purification was made by gel chromatography...

  1. Twitch interpolation technique in testing of maximal muscle strength

    DEFF Research Database (Denmark)

    Bülow, P M; Nørregaard, J; Danneskiold-Samsøe, B

    1993-01-01

    The aim was to study the methodological aspects of the muscle twitch interpolation technique in estimating the maximal force of contraction in the quadriceps muscle utilizing commercial muscle testing equipment. Six healthy subjects participated in seven sets of experiments testing the effects...

  2. Decrease in sarcoplasmic reticulum calcium content, not myofilament function, contributes to muscle twitch force decline in isolated cardiac trabeculae

    Science.gov (United States)

    Milani-Nejad, Nima; Brunello, Lucia; Gyorke, Sándor; Janssen, Paul M.L.

    2014-01-01

    We set out to determine the factors responsible for twitch force decline in isolated intact rat cardiac trabeculae. The contractile force of trabeculae declined over extended periods of isometric twitch contractions. The force-frequency relationship within the frequency range of 4–8 Hz, at 37 °C, became more positive and the frequency optimum shifted to higher rates with this decline in baseline twitch tensions. The post-rest potentiation (37 °C), a phenomenon highly dependent on calcium handling mechanisms, became more pronounced with decrease in twitch tensions. We show that the main abnormality during muscle run-down was not due to a deficit in the myofilaments; maximal tension achieved using a K+ contracture protocol was either unaffected or only slightly decreased. Conversely, the sarcoplasmic reticulum (SR) calcium content, as assessed by rapid cooling contractures (from 27 °C to 0 °C), decreased, and had a close association with the declining twitch tensions (R2 ~ 0.76). SR Ca2+-ATPase, relative to Na+/Ca2+ exchanger activity, was not altered as there was no significant change in paired rapid cooling contracture ratios. Furthermore, confocal microscopy detected no abnormalities in the overall structure of the cardiomyocytes and t-tubules in the cardiac trabeculae (~23 °C). Overall, the data indicates that the primary mechanism responsible for force run-down in multi-cellular cardiac preparations is a decline in the SR calcium content and not the maximal tension generation capability of the myofilaments. PMID:25056841

  3. Paradoxical Acceleration of Dithiothreitol-Induced Aggregation of Insulin in the Presence of a Chaperone

    Directory of Open Access Journals (Sweden)

    Boris Kurganov

    2010-11-01

    Full Text Available The kinetics of dithiothreitol (DTT-induced aggregation of human recombinant insulin and the effect of α-crystallin, a representative of the family of small heat shock proteins, on the aggregation process have been studied using dynamic light scattering technique. Analysis of the distribution of the particles by size measured in the course of aggregation showed that the initial stage of the aggregation process was the stage of formation of the start aggregates with a hydrodynamic radius (Rh of about 90 nm. When studying the effect of α-crystallin on the rate of DTT-induced aggregation of insulin, it was demonstrated that low concentrations of α-crystallin dramatically accelerated the aggregation process, whereas high concentrations of α-crystallin suppressed insulin aggregation. In the present study, at the molar stoichiometric ratio (insulin:α-crystallin less than 1:0.5, a pronounced accelerating effect of α-crystallin was observed; whereas a ratio exceeding the value of 1:0.6 caused suppression of insulin aggregation. The mechanisms underlying the dual effect of α-crystallin have been proposed. It is assumed that heterogeneous nucleation occurring on the surface of the α-crystallin particle plays the key role in the paradoxical acceleration of insulin aggregation by α-crystallin that may provide an alternative biologically significant pathway of the aggregation process.

  4. Use of standard laboratory methods to obviate routine dithiothreitol treatment of blood samples with daratumumab interference.

    Science.gov (United States)

    Lintel, Nicholas J; Brown, Debra K; Schafer, Diane T; Tsimba-Chitsva, Farai M; Koepsell, Scott A; Shunkwiler, Sara M

    2017-01-01

    Daratumumab is an antibody currently used in the treatment of patients with refractory multiple myeloma. Blood samples from patients being treated with daratumumab may show panreactivity during pre-transfusion testing. To facilitate the provision of blood components for such patients, it is recommended that a baseline phenotype or genotype be established prior to starting treatment with daratumumab. If patient red blood cells (RBCs) require phenotyping after the start of daratumumab treatment, dithiothreitol (DTT) treatment of the patient's RBCs should be performed. The medical charts of four patients treated with daratumumab were reviewed. The individual number of doses ranged from 1 to 14; patient age ranged from 55 to 78 years; two men and two women were included in the review. Type and screen data were obtained from samples collected over 33 encounters with a range of 1 to 13 encounters per patient. All samples were tested initially by automated solid-phase testing. Any reactivity with solid phase led to tube testing with either low-ionic-strength saline, polyethylene glycol, or both. If incubation failed to eliminate the reactivity, the sample was sent to a reference laboratory for DTT treatment and phenotyping. Of the 33 samples tested, 23 (69.7%) samples had reactivity in solid-phase testing. In 8 of the 10 samples that did not react in solid-phase, testing was conducted more than four half-lives after the last dose of daratumumab. Of the 23 that had reactivity in solid-phase, 16 (69.6%) samples demonstrated loss of reactivity using common laboratory methods. For the seven patients whose sample reactivity was not initially eliminated, six were provided with phenotypically matched blood based on prior molecular testing. Only one sample was sent out for DTT treatment. These results suggest that daratumumab interference with pre-transfusion testing can be addressed using common laboratory methods. This finding could save time and money for laboratories that do

  5. The effect of dithiothreitol on radiation-induced genetic damage in Arabidopsis thaliana (L) Heynh

    International Nuclear Information System (INIS)

    Dellaert, L.M.W.

    1980-01-01

    A study was made on the effect of dithiothreitol (DTT; present during irradiation) on M 1 ovule sterility, M 2 embryonic lethals, M 2 chlorophyll mutants and M 2 viable mutants induced with fast neutrons or X-rays in Arabidopsis thaliana. DTT provides considerable protection against both fast-neutron and X-ray induced genetic damage. However, a higher protection was observed against M 1 ovule sterility, than against embryonic lethals, chlorophylls and viable mutants. This implies a significant DTT-induced spectral shift (0.01 < p < 0.05), i.e. a shift in the relative frequencies of the different genetic parameters. This spectral shift is explained on the basis of a specific DTT protection against radiation-induced strand breaks, and by differences in the ratio strand breaks/base damage for the genetic parameters concerned, i.e. a higher ratio for ovule sterility than for the other parameters. The induction of the genetic damage by ionizing radiation, either with or without DTT, is described by a mathematical model, which includes both strand breaks and base damage. The model shows that the resolving power of a test for a 'mutation'spectral shift depends on the relative values of the strandbreak reduction factor of -SH compounds and on the ratio strand breaks/base damage of the genetic parameters. For each genetic parameter the DTT damage reduction factor (DRF) is calculated per irradiation dose, and in addition the average (over-all doses) ratio strand breaks/base damage. (orig.)

  6. X-ray and fast neutron-induced mutations in Arabidopsis thaliana, and the effect of dithiothreitol upon the mutant spectrum

    International Nuclear Information System (INIS)

    Dellaert, L.M.W.

    1980-01-01

    The author discusses the genetic effects of X-ray and fast neutron seed-irradiation of Arabidopsis thaliana (L.) Heynh., and the influence of a pre-irradiation treatment with the radio-protector dithiothreitol (DTT). (Auth.)

  7. High efficiency electrotransformation of Lactococcus lactis spp. lactis cells pretreated with lithium acetate and dithiothreitol

    Directory of Open Access Journals (Sweden)

    Filioussis George

    2007-03-01

    Full Text Available Abstract Background A goal for the food industry has always been to improve strains of Lactococcus lactis and stabilize beneficial traits. Genetic engineering is used extensively for manipulating this lactic acid bacterium, while electropolation is the most widely used technique for introducing foreign DNA into cells. The efficiency of electrotransformation depends on the level of electropermealization and pretreatment with chemicals which alter cell wall permeability, resulting in improved transformation efficiencies is rather common practice in bacteria as in yeasts and fungi. In the present study, treatment with lithium acetate (LiAc and dithiothreitol (DTT in various combinations was applied to L. lactis spp. lactis cells of the early-log phase prior to electroporation with plasmid pTRKH3 (a 7.8 kb shuttle vector, suitable for cloning into L. lactis. Two strains of L. lactis spp. lactis were used, L. lactis spp. lactis LM0230 and ATCC 11454. To the best of our knowledge these agents have never been used before with L. lactis or other bacteria. Results Electrotransformation efficiencies of up to 105 transformants per μg DNA have been reported in the literature for L. lactis spp.lactis LM0230. We report here that treatment with LiAc and DDT before electroporation increased transformation efficiency to 225 ± 52.5 × 107 transformants per μg DNA, while with untreated cells or treated with LiAc alone transformation efficiency approximated 1.2 ± 0.5 × 105 transformants per μg DNA. Results of the same trend were obtained with L. lactis ATCC 11454, although transformation efficiency of this strain was significantly lower. No difference was found in the survival rate of pretreated cells after electroporation. Transformation efficiency was found to vary directly with cell density and that of 1010 cells/ml resulted in the highest efficiencies. Following electrotransformation of pretreated cells with LiAc and DDT, pTRKH3 stability was examined

  8. The twitch interpolation technique for study of fatigue of human quadriceps muscle

    DEFF Research Database (Denmark)

    Bülow, P M; Nørregaard, J; Mehlsen, J

    1995-01-01

    The aim of the study was to examine if the twitch interpolation technique could be used to objectively measure fatigue in the quadriceps muscle in subjects performing submaximally. The 'true' maximum isometric quadriceps torque was determined in 21 healthy subject using the twitch interpolation...... technique. Then an endurance test was performed in which the subjects made repeated isometric contractions at 50% of the 'true' maximum torque for 4 s, separated by 6 s rest periods. During the test, the force response to single electrical stimulation (twitch amplitude) was measured at 50% and 25......). In conclusion, the twitch technique can be used for objectively measuring fatigue of the quadriceps muscle....

  9. TWITCH PARAMETERS IN TRANSVERSAL AND LONGITUDINAL BICEPS BRACHII RESPONSE

    Directory of Open Access Journals (Sweden)

    Boštjan Šimunič

    2010-01-01

    Full Text Available Assessment of the contractile properties of skeletal muscles is continuing to be an important issue and a difficult task methodologically. Longitudinal direction of skeletal muscle contraction blurs intrinsic muscle belly contractile properties with many factors. This study evaluates and explains contractile properties such as: delay time (Td, contraction time (Tc, half relaxation time (Tr and maximal amplitude (Dm extracted from twitch transversal response and compare them with torque response. In fifteen healthy males (age 23.7 ± 3.4 years isometric twitch transversal and torque responses were simultaneously recorded during graded electrically elicited contractions in the biceps brachii muscle. The amplitude of electrical stimulation was increased in 5 mA steps from a threshold up to a maximal response. The muscles’ belly transversal response was measured by a high precision mechanical displacement sensor while elbow joint torque was calculated from force readings. Results indicate a parabolic relation between the transversal displacement and the torque Dm. A significantly shorter Tc was found in transversal response without being correlated to torque Tc (r = -0.12; > 0.05. A significant correlation was found between torque Tc and the time occurrence of the second peak in the transversal response (r = 0.83; < 0.001. Electrical stimulation amplitude dependant variation of the Tc was notably different in transversal than in torque response. Td was similar at submaximal and maximal responses but larger in transversal at just above threshold contractions. Tr has a similar linear trend in both responses, however, the magnitude and the slope are much larger in the transversal response. We could conclude that different mechanisms affect longitudinal and transversal twitch skeletal muscle deformations. Contractile properties extracted from the transversal response enable alternative insights into skeletal muscle contraction mechanics.

  10. Cyclosporin A preferentially attenuates skeletal slow-twitch muscle regeneration

    Directory of Open Access Journals (Sweden)

    Miyabara E.H.

    2005-01-01

    Full Text Available Calcineurin, a Ca2+/calmodulin-dependent phosphatase, is associated with muscle regeneration via NFATc1/GATA2-dependent pathways. However, it is not clear whether calcineurin preferentially affects the regeneration of slow- or fast-twitch muscles. We investigated the effect of a calcineurin inhibitor, cyclosporin A (CsA, on the morphology and fiber diameter of regenerating slow- and fast-twitch muscles. Adult Wistar rats (259.5 ± 9 g maintained under standard conditions were treated with CsA (20 mg/kg body weight, ip for 5 days, submitted to cryolesion of soleus and tibialis anterior (TA muscles on the 6th day, and then treated with CsA for an additional 21 days. The muscles were removed, weighed, frozen, and stored in liquid nitrogen. Cryolesion did not alter the body weight gain of the animals after 21 days of regeneration (P = 0.001 and CsA significantly reduced the body weight gain (15.5%; P = 0.01 during the same period. All treated TA and soleus muscles showed decreased weights (17 and 29%, respectively, P < 0.05. CsA treatment decreased the cross-sectional area of both soleus and TA muscles of cryoinjured animals (TA: 2108 ± 930 vs 792 ± 640 µm²; soleus: 2209 ± 322 vs 764 ± 439 m²; P < 0.001. Histological sections of both muscles stained with Toluidine blue revealed similar regenerative responses after cryolesion. In addition, CsA was able to minimize these responses, i.e., centralized nuclei and split fibers, more efficiently so in TA muscle. These results indicate that calcineurin preferentially plays a role in regeneration of slow-twitch muscle.

  11. Evidence that the Na+-K+ leak/pump ratio contributes to the difference in endurance between fast- and slow-twitch muscles.

    Science.gov (United States)

    Clausen, T; Overgaard, K; Nielsen, O B

    2004-02-01

    Muscles containing predominantly fast-twitch (type II) fibres [ext. dig. longus (EDL)] show considerably lower contractile endurance than muscles containing mainly slow-twitch (type I) fibres (soleus). To assess whether differences in Na+-K+ fluxes and excitability might contribute to this phenomenon, we compared excitation-induced Na+-K+ leaks, Na+ channels, Na+-K+ pump capacity, force and compound action potentials (M-waves) in rat EDL and soleus muscles. Isolated muscles were mounted for isometric contractions in Krebs-Ringer bicarbonate buffer and exposed to direct or indirect continuous or intermittent electrical stimulation. The time-course of force decline and concomitant changes in Na+-K+ exchange and M-waves were recorded. During continuous stimulation at 60-120 Hz, EDL showed around fivefold faster rate of force decline than soleus. This was associated with a faster loss of excitability as estimated from the area and amplitude of the M-waves. The net uptake of Na+ and the release of K+ per action potential were respectively 6.5- and 6.6-fold larger in EDL than in soleus, which may in part be due to the larger content of Na+ channels in EDL. During intermittent stimulation with 1 s 60 Hz pulse trains, EDL showed eightfold faster rate of force decline than soleus. The considerably lower contractile endurance of fast-twitch compared with slow-twitch muscles reflects differences in the rate of excitation-induced loss of excitability. This is attributed to the much larger excitation-induced Na+ influx and K+ efflux, leading to a faster rise in [K+]o in fast-twitch muscles. This may only be partly compensated by the concomitant activation of the Na+-K+ pumps, in particular in fibres showing large passive Na+-K+ leaks or reduced content of Na+-K+ pumps. Thus, endurance depends on the leak/pump ratio for Na+ and K+.

  12. Effects of superoxide dismutase, dithiothreitol and formate ion on the inactivation of papain by hydroxyl and superoxide radicals in aerated solutions

    International Nuclear Information System (INIS)

    Lin, W.S.; Armstrong, D.A.

    1978-01-01

    Losses in enzyme activity and sulphydryl content have been studied in aerated papain solutions containing formate, superoxide dismutase and dithiothreitol. Both formate and dithiothreitol converted .OH to .0 2 -, whereas superoxide dismutase completely suppressed the inactivation by .0 2 -. Using results from all systems, the fraction of .0 2 - reactions with papain that caused inactivation of the enzyme was 0.33+-0.07. The results also showed that the fraction of .OH reactions, which cause inactivation of papain, is significantly higher in aerated than in oxygen-free solutions. (author)

  13. Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles.

    Science.gov (United States)

    Plant, David R; Lynch, Gordon S; Williams, David A

    2002-03-15

    The effect of exogenous hydrogen peroxide (H(2)O(2)) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mM H(2)O(2) diminished the ability of the Ca(2+)-depleted SR to reload Ca(2+) in both slow (P fast twitch fibres (P fast twitch fibres by 24 +/- 5 % (P slow twitch fibres. Treatment with 1 mM H(2)O(2) also increased the peak force of low [caffeine] contracture by approximately 45% in both fibre types compared to control (P slow twitch fibres, compared to control (no H(2)O(2); P fast twitch fibres was not altered by 1 mM H(2)O(2) treatment. Equilibration with 5 mM H(2)O(2) induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mM DTT. Peak DICR was also increased approximately 40% by 5 mM H(2)O(2) in slow twitch fibres compared to control (no H(2)O(2); P slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca(2+) release during contraction and/or an increase in Ca(2+) sensitivity.

  14. Comparison of collagen fibre architecture between slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi.

    Science.gov (United States)

    Nakamura, Y N; Iwamoto, H; Tabata, S; Ono, Y

    2003-07-01

    1. Collagen fibre architectures of perimysium and endomysium in the slow-twitch cranial and fast-twitch caudal parts of broiler M. latissimus dorsi were compared. 2. Type I and III collagens were distributed in both perimysium and endomysium as indicated by their positive immunohistochemical reactions to polyclonal antibodies. 3. Cells invested by endomysium with no myofibres were larger in the cranial part because of the presence of larger slow-twitch myofibres. The honeycomb structure of endomysium was divided into several parts by thick perimysium. 4. The thick perimysial collagen fibres with parallel fibrils, which were interconnected by the loose reticular fibrils and thin fibres, were more numerous and thicker in the cranial part than the caudal. 5. Thick endomysial sidewall of cells in the cranial part was composed of a rougher reticulum of slightly thicker collagen fibrils compared with the thin sidewall in the caudal part. 6. These results indicated that both perimysial constitutions of collagen fibres and endomysial collagen fibrils had attained much larger growth in the slow-twitch cranial part than the fast-twitch caudal in broiler latissimus dorsi muscle.

  15. THE EFFECT OF STIMULUS ANTICIPATION ON THE INTERPOLATED TWITCH TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Duane C. Button

    2008-12-01

    Full Text Available The objective of this study was to investigate the effect of expected and unexpected interpolated stimuli (IT during a maximum voluntary contraction on quadriceps force output and activation. Two groups of male subjects who were either inexperienced (MI: no prior experience with IT tests or experienced (ME: previously experienced 10 or more series of IT tests received an expected or unexpected IT while performing quadriceps isometric maximal voluntary contractions (MVCs. Measurements included MVC force, quadriceps and hamstrings electromyographic (EMG activity, and quadriceps inactivation as measured by the interpolated twitch technique (ITT. When performing MVCs with the expectation of an IT, the knowledge or lack of knowledge of an impending IT occurring during a contraction did not result in significant overall differences in force, ITT inactivation, quadriceps or hamstrings EMG activity. However, the expectation of an IT significantly (p < 0.0001 reduced MVC force (9.5% and quadriceps EMG activity (14.9% when compared to performing MVCs with prior knowledge that stimulation would not occur. While ME exhibited non-significant decreases when expecting an IT during a MVC, MI force and EMG activity significantly decreased 12.4% and 20.9% respectively. Overall, ME had significantly (p < 0.0001 higher force (14.5% and less ITT inactivation (10.4% than MI. The expectation of the noxious stimuli may account for the significant decrements in force and activation during the ITT

  16. A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse

    Directory of Open Access Journals (Sweden)

    Craig Robert Wright

    2017-01-01

    Full Text Available Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD. There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S (Seps1 are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion (mdx:Seps1−/+ were generated. The mdx:Seps1−/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL muscles, mRNA expression of monocyte chemoattractant protein 1 (Mcp-1 (P=0.034, macrophage marker F4/80 (P=0.030, and transforming growth factor-β1 (Tgf-β1 (P=0.056 were increased in mdx:Seps1−/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

  17. A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse.

    Science.gov (United States)

    Wright, Craig Robert; Allsopp, Giselle Larissa; Addinsall, Alex Bernard; McRae, Natasha Lee; Andrikopoulos, Sofianos; Stupka, Nicole

    2017-01-01

    Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD). There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S ( Seps1 ) are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion ( mdx : Seps1 -/+ ) were generated. The mdx:Seps1 -/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL) muscles, mRNA expression of monocyte chemoattractant protein 1 ( Mcp-1 ) ( P = 0.034), macrophage marker F4/80 ( P = 0.030), and transforming growth factor-β1 ( Tgf-β1 ) ( P = 0.056) were increased in mdx:Seps1 -/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

  18. Ischemia Increases the Twitch Latent Period in the Soleus and Extensor Carpi Radialis Longus Muscles from Adult Rats.

    Science.gov (United States)

    Morales, Camilo; Fierro, Leonardo

    2017-10-01

    Complete ischemia and reperfusion effects on twitch force (∫(F·t)), twitch latent period (TLP), maximal rate of rise of twitch tension (δF/δt) max , and twitch maximum relaxation rate (TMRR) were assessed. We divided 36 adult rats into four groups; two control groups (n = 9), a group undergoing 1 hour of ischemia followed by 1 hour of reperfusion (n = 9), and one group exposed to 2 hours of ischemia followed by 1 hour of reperfusion (n = 9). We have induced twitch contractions every 10 minutes in the soleus and the extensor carpi radialis longus (ECRL). Twitch contractions were recorded and then analyzed for ∫(F·t), TLP, (δF/δt) max , and TMRR. During 1 hour and 40 minutes of ischemia, TLP increased to 179 ± 24% (p values.

  19. Improved recovery of post-thaw motility and vitality of human spermatozoa cryopreserved in the presence of dithiothreitol.

    Science.gov (United States)

    Rao, B; David, G

    1984-10-01

    Semen was collected in the laboratory from nine healthy donors. The concentrations and the percentages of live and motile spermatozoa in all semen samples were within the normal range. Each sample was diluted with citrate-egg yolk-glycerol medium with and without 5 mM dithiothreitol (DTT). Samples were frozen in liquid nitrogen vapor (-70 degrees C) for 7 min and subsequently stored in liquid nitrogen. The effect of DTT in cryopreservation of sperm was determined by comparing percentage of motile and live spermatozoa between controls and DTT-treated post-thaw samples. Percentage of motile spermatozoa was determined by two techniques, laser Doppler velocimetry (LDV) and light microscopy. The percentage of live spermatozoa was measured by microscopic evaluation after staining with eosin-nigrosin. It was shown that the addition of DTT to the freezing medium significantly improved the recovery of motile and live spermatozoa in the post-thaw samples. The mean motility recovery, as measured by LDV, was 44.9% in the controls as compared to 73.9% in the DTT-treated samples. Similarly the mean recovery of live spermatozoa in the controls and DTT-treated samples was 66.5 and 86.6%, respectively. Based on these results, a new hypothesis implicating lipid peroxidation in cryoinjury is proposed. It is also suggested that the use of DTT in the freezing medium may offer an advantage over the commonly used techniques of human sperm cryopreservation.

  20. Matching of sarcoplasmic reticulum and contractile properties in rat fast- and slow-twitch muscle fibres.

    Science.gov (United States)

    Trinh, Huong H; Lamb, Graham D

    2006-07-01

    1. The twitch characteristics (fast-twitch or slow-twitch) of skeletal muscle fibres are determined not only by the contractile apparatus properties of the fibre, but also by the time-course of Ca2+ release and re-uptake by the sarcoplasmic reticulum (SR). The present study examined, in individual fibres from non-transforming muscle of the rat, whether particular SR properties are matched to the contractile apparatus properties of the fibre, in particular in the case of fibres with fast-twitch contractile apparatus located in a slow-twitch muscle, namely the soleus. 2. Force was recorded in single, mechanically skinned fibres from extensor digitorum longus (EDL), gastrocnemius, peroneus longus and soleus muscles. Using repeated cycles in which the SR was emptied of all releasable Ca2+ and then reloaded, it was possible to determine the relative amount of Ca2+ present in the SR endogenously, the maximum SR capacity and the rate of Ca2+ loading. The sensitivity of the contractile apparatus to Ca2+ and Sr2+ was used to classify the fibres as fast-twitch (FT), slow-twitch (ST) or mixed (fibres examined) and thereby identify the likely troponin C and myosin heavy chain types present. 3. There was no significant difference in SR properties between the groups of FT fibres obtained from the four different muscles, including soleus. Despite some overlap in the SR properties of individual fibres between the FT and ST groups, the properties of the FT fibres in all four muscles studied were significantly different from those of the ST and mixed fibres. 4. In general, in FT fibres the SR had a larger capacity and the endogenous Ca2+ content was a relatively lower percentage of maximum compared with ST fibres. Importantly, in terms of their SR properties, FT fibres from soleus muscle more closely resembled FT fibres from other muscles than they did ST fibres from soleus muscle.

  1. The role of Six1 in muscle progenitor cells and the establishment of fast-twitch muscle fibres

    OpenAIRE

    Nord, Hanna

    2014-01-01

    Myogenesis is the process of skeletal muscle tissue formation where committed muscle progenitor cells differentiate into skeletal muscle fibres. Depending on the instructive cues the muscle progenitor cells receive they will differentiate into specific fibre types with different properties. The skeletal muscle fibres can be broadly classified as fast-twitch fibres or slow-twitch fibres, based on their contractile speed. However, subgroups of fast- and slow-twitch fibres with different metabol...

  2. Visualization of Twitching Motility and Characterization of the Role of the PilG in Xylella fastidiosa.

    Science.gov (United States)

    Shi, Xiangyang; Lin, Hong

    2016-04-08

    Xylella fastidiosa is a Gram-negative non-flagellated bacterium that causes a number of economically important diseases of plants. The twitching motility provides X. fastidiosa a means for long-distance intra-plant movement and colonization, contributing toward pathogenicity in X. fastidiosa. The twitching motility of X. fastidiosa is operated by type IV pili. Type IV pili of Xylella fastidiosa are regulated by pilG, a chemotaxis regulator in Pil-Chp operon encoding proteins that are involved with signal transduction pathways. To elucidate the roles of pilG in the twitching motility of X. fastidiosa, a pilG-deficient mutant XfΔpilG and its complementary strain XfΔpilG-C containing native pilG were developed. A microfluidic chambers integrated with a time-lapse image recording system was used to observe twitching motility in XfΔpilG, XfΔpilG-C and its wild type strain. Using this recording system, it permits long-term spatial and temporal observations of aggregation, migration of individual cells and populations of bacteria via twitching motility. X. fastidiosa wild type and complementary XfΔpilG-C strain showed typical twitching motility characteristics directly observed in the microfluidic flow chambers, whereas mutant XfΔpliG exhibited the twitching deficient phenotype. This study demonstrates that pilG contributes to the twitching motility of X. fastidiosa. The microfluidic flow chamber is used as a means for observing twitching motility.

  3. Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa.

    Science.gov (United States)

    Cursino, Luciana; Li, Yaxin; Zaini, Paulo A; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J

    2009-10-01

    A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this protein. This is the first report demonstrating a functional role for a tonB homolog in X. fastidiosa.

  4. Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa

    OpenAIRE

    Cursino, Luciana; Li, Yaxin; Zaini, Paulo A.; De La Fuente, Leonardo; Hoch, Harvey C.; Burr, Thomas J.

    2017-01-01

    A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this prote...

  5. The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

    Science.gov (United States)

    Hollingworth, S; Marshall, M W; Robson, E

    1990-02-01

    1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.

  6. Type 2 iodothyronine deiodinase levels are higher in slow-twitch than fast-twitch mouse skeletal muscle and are increased in hypothyroidism.

    Science.gov (United States)

    Marsili, Alessandro; Ramadan, Waile; Harney, John W; Mulcahey, Michelle; Castroneves, Luciana Audi; Goemann, Iuri Martin; Wajner, Simone Magagnin; Huang, Stephen A; Zavacki, Ann Marie; Maia, Ana Luiza; Dentice, Monica; Salvatore, Domenico; Silva, J Enrique; Larsen, P Reed

    2010-12-01

    Because of its large mass, relatively high metabolic activity and responsiveness to thyroid hormone, skeletal muscle contributes significantly to energy expenditure. Despite the presence of mRNA encoding the type 2 iodothyronine-deiodinase (D2), an enzyme that activates T(4) to T3, very low or undetectable activity has been reported in muscle homogenates of adult humans and mice. With a modified D2 assay, using microsomal protein, overnight incubation and protein from D2 knockout mouse muscle as a tissue-specific blank, we examined slow- and fast-twitch mouse skeletal muscles for D2 activity and its response to physiological stimuli. D2 activity was detectable in all hind limb muscles of 8- to 12-wk old C57/BL6 mice. Interestingly, it was higher in the slow-twitch soleus than in fast-twitch muscles (0.40 ± 0.06 vs. 0.076 ± 0.01 fmol/min · mg microsomal protein, respectively, P Hypothyroidism caused a 40% (P hypothyroidism argue for a more important role for D2-generated T(3) in skeletal muscle physiology than previously assumed.

  7. Blood flow response to electrically induced twitch and tetanic lower-limb muscle contractions.

    NARCIS (Netherlands)

    Janssen, T.W.; Hopman, M.T.E.

    2003-01-01

    OBJECTIVES: To compare the effect of electric stimulation (ES)-induced twitch with tetanic leg muscle contractions on blood flow responses and to assess blood flow responses in the contralateral inactive leg. DESIGN: Intervention with within-subject comparisons. SETTING: University research

  8. Differences between glycogen biogenesis in fast- and slow-twitch rabbit muscle

    DEFF Research Database (Denmark)

    Cussó, R; Lerner, L R; Cadefau, J

    2003-01-01

    Skeletal muscle glycogen is an essential energy substrate for muscular activity. The biochemical properties of the enzymes involved in de novo synthesis of glycogen were analysed in two types of rabbit skeletal muscle fiber (fast- and slow-twitch). Glycogen concentration was higher in fast...

  9. Identification of an operon, Pil-Chp, that controls twitching motility and virulence in Xylella fastidiosa.

    Science.gov (United States)

    Cursino, Luciana; Galvani, Cheryl D; Athinuwat, Dusit; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia

    2011-10-01

    Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.

  10. MAGNETIC VERSUS ELECTRICAL STIMULATION IN THE INTERPOLATION TWITCH TECHNIQUE OF ELBOW FLEXORS

    Directory of Open Access Journals (Sweden)

    Sofia I. Lampropoulou

    2012-12-01

    Full Text Available The study compared peripheral magnetic with electrical stimulation of the biceps brachii m. (BB in the single pulse Interpolation Twitch Technique (ITT. 14 healthy participants (31±7 years participated in a within-subjects repeated-measures design study. Single, constant-current electrical and magnetic stimuli were delivered over the motor point of BB with supramaximal intensity (20% above maximum at rest and at various levels of voluntary contraction. Force measurements from right elbow isometric flexion and muscle electromyograms (EMG from the BB, the triceps brachii m. (TB and the abductor pollicis brevis m. (APB were obtained. The twitch forces at rest and maximal contractions, the twitch force-voluntary force relationship, the M-waves and the voluntary activation (VA of BB between magnetic and electrical stimulation were compared. The mean amplitude of the twitches evoked at MVC was not significantly different between electrical (0.62 ± 0.49 N and magnetic (0.81 ± 0.49 N stimulation (p > 0.05, and the maximum VA of BB was comparable between electrical (95% and magnetic (93% stimulation (p > 0. 05. No differences (p >0.05 were revealed in the BB M-waves between electrical (13.47 ± 0.49 mV.ms and magnetic (12.61 ± 0.58 mV.ms stimulation. The TB M-waves were also similar (p > 0.05 but electrically evoked APB M-waves were significantly larger than those evoked by magnetic stimulation (p < 0.05. The twitch-voluntary force relationship over the range of MVCs was best described by non-linear functions for both electrical and magnetic stimulation. The electrically evoked resting twitches were consistently larger in amplitude than the magnetically evoked ones (mean difference 3.1 ± 3.34 N, p < 0.05. Reduction of the inter-electrodes distance reduced the twitch amplitude by 6.5 ± 6.2 N (p < 0.05. The fundamental similarities in voluntary activation assessment of BB with peripheral electrical and magnetic stimulation point towards a promising

  11. Effect of ADP on slow-twitch muscle fibres of the rat: implications for muscle fatigue.

    Science.gov (United States)

    Macdonald, W A; Stephenson, D G

    2006-05-15

    Slow-twitch mechanically skinned fibres from rat soleus muscle were bathed in solutions mimicking the myoplasmic environment but containing different [ADP] (0.1 microm to 1.0 mm). The effect of ADP on sarcoplasmic reticulum (SR) Ca2+-content was determined from the magnitude of caffeine-induced force responses, while temporal changes in SR Ca2+-content allowed determination of the effective rates of the SR Ca2+-pump and of the SR Ca2+-leak. The SR Ca2+-pump rate, estimated at pCa (-log10[Ca2+]) 7.8, was reduced by 20% as the [ADP] was increased from 0.1 to 40 microm, with no further alteration when the [ADP] was increased to 1.0 mm. The SR Ca2+-leak rate constant was not altered by increasing [ADP] from 0.1 to 40 microm, but was increased by 26% when the [ADP] was elevated to 1.0 mm. This ADP-induced SR Ca2+-leak was insensitive to ruthenium red but was abolished by 2,5-di(tert-butyl)-1,4-hydroquinone (TBQ), indicating that the leak pathway is via the SR Ca2+-pump and not the SR Ca2+-release channel. The decrease in SR Ca2+-pump rate and SR Ca2+-leak rate when [ADP] was increased led to a 40% decrease in SR Ca2+-loading capacity. Elevation of [ADP] had only minor direct effects on the contractile apparatus of slow-twitch fibres. These results suggest that ADP has only limited depressing effects on the contractility of slow-twitch muscle fibres. This is in contrast to the marked effects of ADP on force responses in fast-twitch muscle fibres and may contribute to the fatigue-resistant nature of slow-twitch muscle fibres.

  12. Moving People from Science Adjacent to Science Doers with Twitch.tv

    Science.gov (United States)

    Gay, Pamela L.; CosmoQuest

    2017-10-01

    The CosmoQuest community is testing the ability to attract people from playing online videogames to doing fully online citizen science by engaging people through the Twitch.tv streaming platform. Twitch.tv launched in 2011 as an online platform for video gamers to stream their gameplay while providing narrative. In its six years of regular growth, the platform has added support for people playing non-video games, and for those participating in non-game activities. As part of their expansion, in April 2017, Twitch.tv hosted a science week during which they streamed the Cosmos series and allowed different feeds provide real-time commentary. They also hosted panel discussions on a variety of science topics. CosmoQuest participated in this event and used it as a jumping off point for beginning to interact with Twitch.tv community members online. With CosmoQuest’s beta launch of Image Detectives, they expanded their use of this streaming platform to include regular “office hours”, during which team members did science with CosmoQuest’s online projects, took questions from community members, and otherwise promoted the CosmoQuest community. This presentation examines this case study, and looks at how well different kinds of Twitter engagements attracted audiences, the conversion rate from viewer to subscriber, and at how effectively CosmoQuest was able to migrate users from viewing citizen science on Twitch.tv to participating in citizen science on CosmoQuest.org.This project was supported through NASA cooperative agreement NNX17AD20A.

  13. Charge Movement in a Fast Twitch Skeletal Muscle from Rat

    OpenAIRE

    Simon, B. J.; Beam, K. G.

    1983-01-01

    Voltage-dependent charge movement in the rat omohyoid muscle was investigated using the three microelectrode voltage clamp technique. The charge that moved during a depolarization from the holding potential (-90 mV) to the test potential, V, increased with increasing V, saturating around 0 mV. The charge vs. voltage relationship was well fitted by Q = Qmax/{1 + exp[-(V - V)/k]}, with Qmax = 28.5 nC/μF, V = -34.2 mV, and k = 8.7 mV. Repolarization of the fiber from the test potential back to t...

  14. Effect of tibial bone resection on the development of fast- and slow-twitch skeletal muscles in foetal sheep.

    Science.gov (United States)

    West, J M; Williams, N A; Luff, A R; Walker, D W

    2000-04-01

    To determine if longitudinal bone growth affects the differentiation of fast- and slow-twitch muscles, the tibial bone was sectioned at 90 days gestation in foetal sheep so that the lower leg was permanently without structural support. At 140 days (term is approximately 147 days) the contractile properties of whole muscles, activation profiles of single fibres and ultrastructure of fast- and slow-twitch muscles from the hindlimbs were studied. The contractile and activation profiles of the slow-twitch soleus muscles were significantly affected by tibial bone resection (TIBX). The soleus muscles from the TIBX hindlimbs showed: (1) a decrease in the time to peak of the twitch responses from 106.2 +/- 10.7 ms (control, n = 4) to 65.1 +/- 2.48 ms (TIBX, n = 5); (2) fatigue profiles more characteristic of those observed in the fast-twitch muscles: and (3) Ca2+ - and Sr2+ -activation profiles of skinned fibres similar to those from intact hindlimbs at earlier stages of gestation. In the FDL, TIBX did not significantly change whole muscle twitch contraction time, the fatigue profile or the Ca2+ - and Sr2+ -activation profiles of skinned fibres. Electron microscopy showed an increased deposition of glycogen in both soleus and FDL muscles. This study shows that the development of the slow-twitch phenotype is impeded in the absence of the physical support normally provided by the tibial bone. We suggest that longitudinal stretch is an important factor in allowing full expression of the slow-twitch phenotype.

  15. The relationship between passive stiffness and evoked twitch properties: the influence of muscle CSA normalization

    International Nuclear Information System (INIS)

    Ryan, E D; Thompson, B J; Sobolewski, E J; Herda, T J; Costa, P B; Walter, A A; Cramer, J T

    2011-01-01

    Passive stiffness measurements are often used as a clinical tool to examine a muscle's passive lengthening characteristics. The purpose of this study was to examine the relationship between passive stiffness and evoked twitch properties prior to and following normalization of passive stiffness to muscle cross-sectional area (CSA). Ten healthy volunteers (mean ± SD age = 23 ± 3 year) performed passive range of motion, evoked twitch, and muscle CSA assessments of the plantar flexor muscles. Passive stiffness was determined from the slope of the final 5° of the angle–torque curve. Peak twitch torque (PTT) and rate of torque development (RTD) were determined via transcutaneous electrical stimulation, and muscle CSA was assessed using a peripheral quantitative computed tomography scanner. Pearson product moment correlation coefficients (r) were used to assess the relationships between passive stiffness and PTT and RTD and normalized passive stiffness (passive stiffness . muscle CSA −1 ) and PTT and RTD. Significant positive relationships were observed between passive stiffness and PTT (P = 0.003, r = 0.828) and RTD (P = 0.003, r = 0.825). There were no significant relationships between normalized passive stiffness and PTT (P = 0.290, r = 0.372) or RTD (P = 0.353, r = 0.329) demonstrating that stiffness did not account for a significant portion of the variance in twitch properties. Passive stiffness was largely influenced by the amount of muscle tissue in this study. Future studies that examine muscle stiffness and its relationship with performance measures, among different populations, and following various interventions may consider normalizing stiffness measurements to muscle CSA

  16. The Major Outer Membrane Protein MopB Is Required for Twitching Movement and Affects Biofilm Formation and Virulence in Two Xylella fastidiosa strains.

    Science.gov (United States)

    Chen, Hongyu; Kandel, Prem P; Cruz, Luisa F; Cobine, Paul A; De La Fuente, Leonardo

    2017-11-01

    MopB is a major outer membrane protein (OMP) in Xylella fastidiosa, a bacterial plant pathogen that causes losses on many economically important crops. Based on in silico analysis, the uncharacterized MopB protein of X. fastidiosa contains a β-barrel structure with an OmpA-like domain and a predicted calcium-binding motif. Here, MopB function was studied by mutational analysis taking advantage of the natural competence of X. fastidiosa. Mutants of mopB were constructed in two different X. fastidiosa strains, the type strain Temecula and the more virulent WM1-1. Deletion of the mopB gene impaired cell-to-cell aggregation, surface attachment, and biofilm formation in both strains. Interestingly, mopB deletion completely abolished twitching motility. Electron microscopy of the bacterial cell surface revealed that mopB deletion eliminated type IV and type I pili formation, potentially caused by destabilization of the outer membrane. Both mopB mutants showed reduced virulence using tobacco (Nicotiana tabacum) as a host under greenhouse conditions. These results suggest that MopB has pleiotropic functions in biofilm formation and twitching motility and is important for virulence of X. fastidiosa.

  17. Prdm1a and miR-499 act sequentially to restrict Sox6 activity to the fast-twitch muscle lineage in the zebrafish embryo.

    Science.gov (United States)

    Wang, XinGang; Ono, Yosuke; Tan, Swee Chuan; Chai, Ruth JinFen; Parkin, Caroline; Ingham, Philip W

    2011-10-01

    Sox6 has been proposed to play a conserved role in vertebrate skeletal muscle fibre type specification. In zebrafish, sox6 transcription is repressed in slow-twitch progenitors by the Prdm1a transcription factor. Here we identify sox6 cis-regulatory sequences that drive fast-twitch-specific expression in a Prdm1a-dependent manner. We show that sox6 transcription subsequently becomes derepressed in slow-twitch fibres, whereas Sox6 protein remains restricted to fast-twitch fibres. We find that translational repression of sox6 is mediated by miR-499, the slow-twitch-specific expression of which is in turn controlled by Prdm1a, forming a regulatory loop that initiates and maintains the slow-twitch muscle lineage.

  18. YouTube Live and Twitch: A Tour of User-Generated Live Streaming Systems

    OpenAIRE

    Pires , Karine; SIMON , Gwendal

    2015-01-01

    International audience; User-Generated live video streaming systems are services that allow anybody to broadcast a video stream over the Internet. These Over-The-Top services have recently gained popularity, in particular with e-sport, and can now be seen as competitors of the traditional cable TV. In this paper, we present a dataset for further works on these systems. This dataset contains data on the two main user-generated live streaming systems: Twitch and the live service of YouTube. We ...

  19. Fast-twitch glycolytic skeletal muscle is predisposed to age-induced impairments in mitochondrial function

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Díaz, Víctor; Soldini, Lavinia

    2013-01-01

    The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high-resolution respirom......The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high......-resolution respirometry and mitochondrial protein expression in soleus, quadricep, and lateral gastrocnemius skeletal muscles, which represent type 1 slow-twitch oxidative muscle (soleus) and type 2 fast-twitch glycolytic muscle (quadricep and gastrocnemius), respectively, in young (10-12 weeks) and mature (74-76 weeks......) mice. Electron transport through mitochondrial complexes I and III increases with age in quadricep and gastrocnemius, which is not observed in soleus. Mitochondrial coupling efficiency during respiration through complex I also deteriorates with age in gastrocnemius and shows a tendency (p = .085...

  20. Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

    Science.gov (United States)

    Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

    2002-08-15

    The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination.

  1. Developmental changes in the activation properties and ultrastructure of fast- and slow-twitch muscles from fetal sheep.

    Science.gov (United States)

    West, J M; Barclay, C J; Luff, A R; Walker, D W

    1999-04-01

    At early stages of muscle development, skeletal muscles contract and relax slowly, regardless of whether they are destined to become fast- or slow-twitch. In this study, we have characterised the activation profiles of developing fast- and slow-twitch muscles from a precocial species, the sheep, to determine if the activation profiles of the muscles are characteristically slow when both the fast- and slow-twitch muscles have slow isometric contraction profiles. Single skinned muscle fibres from the fast-twitch flexor digitorum longus (FDL) and slow-twitch soleus muscles from fetal (gestational ages 70, 90, 120 and 140 days; term 147 days) and neonatal (8 weeks old) sheep were used to determine the isometric force-pCa (pCa = -log10[Ca2+]) and force-pSr relations during development. Fast-twitch mammalian muscles generally have a greatly different sensitivity to Ca2+ and Sr2+ whereas slow-twitch muscles have a similar sensitivity to these divalent cations. At all ages studied, the force-pCa and force-pSr relations of the FDL muscle were widely separated. The mean separation of the mid-point of the curves (pCa50-pSr50) was approximately 1.1. This is typical of adult fast-twitch muscle. The force-pCa and force-pSr curves for soleus muscle were also widely separated at 70 and 90 days gestation (pCa50-pSr50 approximately 0.75); between 90 days and 140 days this separation decreased significantly to approximately 0.2. This leads to a paradoxical situation whereby at early stages of muscle development the fast muscles have contraction dynamics of slow muscles but the slow muscles have activation profiles more characteristic of fast muscles. The time course for development of the FDL and soleus is different, based on sarcomere structure with the soleus muscle developing clearly defined sarcomere structure earlier in gestation than the FDL. At 70 days gestation the FDL muscle had no clearly defined sarcomeres. Force (N cm-2) increased almost linearly between 70 and 140 days

  2. Time-resolved X-ray diffraction studies of frog skeletal muscle isometrically twitched by two successive stimuli using synchrotron radiation

    International Nuclear Information System (INIS)

    Tanaka, Hidehiro; Kobayashi, Takakazu; Wakabayashi, Katsuzo

    1986-01-01

    In order to clarify the delay between muscular structural changes and mechanical responses, the intensity changes of the equatorial and myosin layer-line reflections were studied by a time-resolved X-ray diffraction technique using synchrotron radiation. The muscle was stimulated at 12-13 0 C by two successive stimuli at an interval during which the second twitch started while tension was still being exerted by the muscle. At the first twitch, the intensity changes of the 1,0 and 1,1 equatorial reflections reached 65 and 200% of the resting values, and further changes to 55 and 220% were seen at the second twitch, respectively. Although the second twitch decreased not only the time to peak tension but also that to the maximum intensity changes of the equatorial reflections, the delay between the intensity changes and the development of tension at the first twitch were still observed at the second twitch. On the other hand, the intensities of the 42.9 nm off-meridional and the 21.5 nm meridional myosin reflections decreased at the first twitch to the levels found when a muscle was isometrically tetanized, and no further decrease in their intensities was observed at the second twitch. These results indicate that a certain period of time is necessary for myosin heads to contr0116e to tension development after their arrival in the vicinity of the thin filaments during contraction. (Auth.)

  3. Accumulation of ceramide in slow-twitch muscle contributes to the development of insulin resistance in the obese JCR:LA-cp rat.

    Science.gov (United States)

    Fillmore, Natasha; Keung, Wendy; Kelly, Sandra E; Proctor, Spencer D; Lopaschuk, Gary D; Ussher, John R

    2015-06-01

    What is the central question of this study? The aim was to determine whether the accumulation of ceramide contributes to skeletal muscle insulin resistance in the JCR obese rat. What is the main finding and its importance? Our main new finding is that ceramides accumulate only in slow-twitch skeletal muscle in the JCR obese rat and that reducing ceramide content in this muscle type by inhibition of serine palmitoyl transferase-1 halts the progression of insulin resistance in this rat model predisposed to early development of type 2 diabetes. Our findings highlight the importance of assessing insulin signalling/sensitivity and lipid intermediate accumulation in different muscle fibre types. It has been postulated that insulin resistance results from the accumulation of cytosolic lipid metabolites (i.e. diacylglycerol/ceramide) that impede insulin signalling and impair glucose homeostasis. De novo ceramide synthesis is catalysed by serine palmitoyl transferase-1. Our aim was to determine whether de novo ceramide synthesis plays a role during development of insulin resistance in the JCR:LA-cp obese rat. Ten-week-old JCR:LA-cp obese rats were supplemented with either vehicle or the serine palmitoyl transferase-1 inhibitor l-cycloserine (360 mg l(-1) ) in their drinking water for a 2 week period, and glycaemia was assessed by meal tolerance testing. Treatment of JCR:LA-cp obese rats with l-cycloserine improved their plasma glucose and insulin levels during a meal tolerance test. Examination of muscle lipid metabolites and protein phosphorylation patterns revealed differential signatures in slow-twitch (soleus) versus fast-twitch muscle (gastrocnemius), in that ceramide levels were increased in soleus but not gastrocnemius muscles of JCR:LA-cp obese rats. Likewise, improved glycaemia in l-cycloserine-treated JCR:LA-cp obese rats was associated with enhanced Akt and pyruvate dehydrogenase signalling in soleus but not gastrocnemius muscles, probably as a result of l

  4. Calcium-Enhanced Twitching Motility in Xylella fastidiosa Is Linked to a Single PilY1 Homolog.

    Science.gov (United States)

    Cruz, Luisa F; Parker, Jennifer K; Cobine, Paul A; De La Fuente, Leonardo

    2014-12-01

    The plant-pathogenic bacterium Xylella fastidiosa is restricted to the xylem vessel environment, where mineral nutrients are transported through the plant host; therefore, changes in the concentrations of these elements likely impact the growth and virulence of this bacterium. Twitching motility, dependent on type IV pili (TFP), is required for movement against the transpiration stream that results in basipetal colonization. We previously demonstrated that calcium (Ca) increases the motility of X. fastidiosa, although the mechanism was unknown. PilY1 is a TFP structural protein recently shown to bind Ca and to regulate twitching and adhesion in bacterial pathogens of humans. Sequence analysis identified three pilY1 homologs in X. fastidiosa (PD0023, PD0502, and PD1611), one of which (PD1611) contains a Ca-binding motif. Separate deletions of PD0023 and PD1611 resulted in mutants that still showed twitching motility and were not impaired in attachment or biofilm formation. However, the response of increased twitching at higher Ca concentrations was lost in the pilY1-1611 mutant. Ca does not modulate the expression of any of the X. fastidiosa PilY1 homologs, although it increases the expression of the retraction ATPase pilT during active movement. The evidence presented here suggests functional differences between the PilY1 homologs, which may provide X. fastidiosa with an adaptive advantage in environments with high Ca concentrations, such as xylem sap. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. L-carnitine pretreatment protects slow-twitch skeletal muscles in a rat model of ischemia-reperfusion injury.

    Science.gov (United States)

    Demirel, Mert; Kaya, Burak; Cerkez, Cem; Ertunc, Mert; Sara, Yildirim

    2013-10-01

    Ischemia-reperfusion (I/R) injury negatively affects the outcome of surgical interventions for amputated or severely traumatized extremities. This study aimed to evaluate the protective role of l-carnitine on the contractile properties of fast-twitch (extensor digitorum longus [EDL]) and slow-twitch (soleus [SOL]) skeletal muscles following I/R-induced injury in a rat model. Rats were divided into 4 groups (1) saline pretreatment, (2) l-carnitine pretreatment, (3) saline pretreatment and I/R, and (4) l-carnitine pretreatment and I/R. Twitch and tetanic contractions in the EDL and SOL muscles in each group were recorded. Additionally, a fatigue protocol was performed in these muscles. Twitch and tetanic contraction amplitudes were lower in the EDL and SOL muscles in which I/R was induced (P contraction amplitude in the SOL muscles following I/R (P muscles. l-Carnitine pretreatment did not alter the fatigue response in any of the muscles.

  6. Can fast-twitch muscle fibres be selectively recruited during lengthening contractions? Review and applications to sport movements.

    Science.gov (United States)

    Chalmers, Gordon R

    2008-01-01

    Literature examining the recruitment order of motor units during lengthening (eccentric) contractions was reviewed to determine if fast-twitch motor units can be active while lower threshold slow-twitch motor units are not active. Studies utilizing surface electromyogram (EMG) amplitude, single motor unit activity, spike amplitude-frequency analyses, EMG power spectrum, mechanomyographic, and phosphocreatine-to-creatine ratio (PCr/Cr) techniques were reviewed. Only single motor unit and PCr/Cr data were found to be suitable to address the goals of this review. Nine of ten single motor unit studies, examining joint movement velocities up to 225 degrees/s and forces up to 53% of a maximum voluntary contraction, found that the size principle of motor unit recruitment applied during lengthening contractions. Deviation from the size principle was demonstrated by one study examining movements within a small range of low velocities and modest forces, although other studies examining similar low forces and lengthening velocities reported size-ordered recruitment. The PCr/Cr data demonstrated the activation of all fibre types in lengthening maximal contractions. Most evidence indicates that for lengthening contractions of a wide range of efforts and speeds, fast-twitch muscle fibres cannot be selectively recruited without activity of the slow-twitch fibres of the same muscle.

  7. An Active Learning Mammalian Skeletal Muscle Lab Demonstrating Contractile and Kinetic Properties of Fast- and Slow-Twitch Muscle

    Science.gov (United States)

    Head, S. I.; Arber, M. B.

    2013-01-01

    The fact that humans possess fast and slow-twitch muscle in the ratio of approximately 50% has profound implications for designing exercise training strategies for power and endurance activities. With the growth of exercise and sport science courses, we have seen the need to develop an undergraduate student laboratory that demonstrates the basic…

  8. Effects of resistance training on fast- and slow-twitch muscles in rats

    Directory of Open Access Journals (Sweden)

    M Umnova

    2010-09-01

    Full Text Available The purpose of this study was to investigate the effect of resistance training (RT on muscle strength, the dependence of that on the fast-twitch (FT and slow-twitch (ST fibers hypertrophy, nuclear domain size, synthesis and degradation rate of contractile proteins and on the expression of myosin isoforms’. 16 weeks old Wistar rats were trained on a vertical treadmill for six days a week during six weeks. The power of exercise increased 4.9% per session. In RT group the mass of studied muscles increased about 10%, hindlimb grip strength increased from 5.20±0.27 N/100g bw to the 6.05±0.29 N/100g bw (p<0.05. Cross-sectional area and number of myonuclei of FT and ST fibers in plantaris (Pla and soleus (Sol muscles increased, myonuclear domain size did not change significantly. RT increased the MyHC IId isoforms relative content and decreased that of IIb and IIa isoforms in Pla muscle, in Sol muscle increased only IIa isoform. In Pla muscle the relative content of myosin light chain (MyLC 1slow and 2slow isoforms decreased and that of MyLC 2fast isoforms increased during RT. MyLC 3 and MyLC 2 ratio did not change significantly in Pla but increased in Sol muscle by 14.3±3.4�0(p<0.01. The rat RT programme caused hypertrophy of FT and ST muscle fibers, increase of myonuclear number via fusion of satellite cells with damaged fibers or formation of new muscle fibers as a result of myoblast fusion and myotubes formation, maintaining myonuclear domain size.

  9. Cycle Training Increased GLUT4 and Activation of mTOR in Fast Twitch Muscle Fibers

    Science.gov (United States)

    Stuart, Charles A.; Howell, Mary E.A.; Baker, Jonathan D.; Dykes, Rhesa J.; Duffourc, Michelle M.; Ramsey, Michael W.; Stone, Michael H.

    2009-01-01

    Purpose To determine if cycle training of sedentary subjects would increase the expression of the principle muscle glucose transporters, six volunteers completed six weeks of progressively increasing intensity stationary cycle cycling. Methods In vastus lateralis muscle biopsies, changes in expression of GLUT1, GLUT4, GLUT5, and GLUT12 were compared using quantitative immunoblots with specific protein standards. Regulatory pathway components were evaluated by immunoblots of muscle homogenates and immunohistochemistry of microscopic sections. Results GLUT1 was unchanged, GLUT4 increased 66%, GLUT12 increased 104%, and GLUT5 decreased 72%. A mitochondrial marker (cytochrome c) and regulators of mitochondrial biogenesis (PGC-1α and phospho-AMPK) were unchanged, but the muscle hypertrophy pathway component, phospho-mTOR increased 83% after the exercise program. In baseline biopsies, GLUT4 by immunohistochemical techniques was 37% greater in Type I (slow twitch, red) muscle fibers, but the exercise training increased GLUT4 expression in Type II (fast twitch, white) fibers by 50%, achieving parity with the Type I fibers. Baseline phospho-mTOR expression was 50% higher in Type II fibers and increased more in Type II fibers (62%) with training, but also increased in Type I fibers (34%). Conclusion Progressive intensity stationary cycle training of previously sedentary subjects increased muscle insulin-responsive glucose transporters (GLUT4 and GLUT12) and decreased the fructose transporter (GLUT5). The increase in GLUT4 occurred primarily in Type II muscle fibers and this coincided with activation of the mTOR muscle hypertrophy pathway. There was little impact on Type I fiber GLUT4 expression and no evidence of change in mitochondrial biogenesis. PMID:20010125

  10. Time-resolved x-ray diffraction from frog skeletal muscle during an isotonic twitch under a small load

    International Nuclear Information System (INIS)

    Sugi, Haruo; Amemiya, Yoshiyuki; Hashizume, Hiroo.

    1978-01-01

    A time-resolved x-ray diffraction technique was used to study the time course of change in the intensity ratio Isub(1,0)/Isub(1,1) during isotonic twitch (initial sarcomere, 2.4 μm) under a small load and to determine the kinetic properties of the crossbridges responsible for muscle contraction. Isotonic twitches in four other preparations with an initial sarcomere of 2.4 μm and in two with an initial sarcomere of 2.3 μm and 2.2 μm, respectively, were examined. In each case, the intensity ratio started to decrease at stimulation, reached a minimum value of 0.8 - 1.0 within the first 20 - 30% of the shortening phase, and maintained this value until the beginning of the relaxation phase. Gradual recovery of the intensity ratio to the resting value was seen during the relaxation phase. During the recovery phase, the intensity ratio appeared to exhibit oscillatory changes. Though the extent of shortening was reduced by about 30% at the end of each experiment, the duration of the shortening phase remained almost unchanged in all the preparations examined. The time course of change in the intensity ratio was also examined during an isometric twitch in four preparations (sarcomere, 2.4 μm) with the tibial end connected to a strain gauge. The extent of internal shortening of muscle fibres against the tendons and the recording system during an isometric twitch or a tetanus at low temperatures was estimated. The intensity ratio decreased to a minimum value of 0.5 - 0.6 during the rising phase of isometric tension and started to return to the resting value after the beginning of relaxation. In both isotonic and isometric twitches, a decrease in the intensity ratio resulted from both a decrease in the 1,0 intensity and an increase in the 1,1 intensity. (J.P.N.)

  11. Observation of the molecular organization of calcium release sites in fast- and slow-twitch skeletal muscle with nanoscale imaging.

    Science.gov (United States)

    Jayasinghe, Isuru D; Munro, Michelle; Baddeley, David; Launikonis, Bradley S; Soeller, Christian

    2014-10-06

    Localization microscopy is a fairly recently introduced super-resolution fluorescence imaging modality capable of achieving nanometre-scale resolution. We have applied the dSTORM variation of this method to image intracellular molecular assemblies in skeletal muscle fibres which are large cells that critically rely on nanoscale signalling domains, the triads. Immunofluorescence staining in fixed adult rat skeletal muscle sections revealed clear differences between fast- and slow-twitch fibres in the molecular organization of ryanodine receptors (RyRs; the primary calcium release channels) within triads. With the improved resolution offered by dSTORM, abutting arrays of RyRs in transverse view of fast fibres were observed in contrast to the fragmented distribution on slow-twitch muscle that were approximately 1.8 times shorter and consisted of approximately 1.6 times fewer receptors. To the best of our knowledge, for the first time, we have quantified the nanometre-scale spatial association between triadic proteins using multi-colour super-resolution, an analysis difficult to conduct with electron microscopy. Our findings confirm that junctophilin-1 (JPH1), which tethers the sarcoplasmic reticulum ((SR) intracellular calcium store) to the tubular (t-) system at triads, was present throughout the RyR array, whereas JPH2 was contained within much smaller nanodomains. Similar imaging of the primary SR calcium buffer, calsequestrin (CSQ), detected less overlap of the triad with CSQ in slow-twitch muscle supporting greater spatial heterogeneity in the luminal Ca2+ buffering when compared with fast twitch muscle. Taken together, these nanoscale differences can explain the fundamentally different physiologies of fast- and slow-twitch muscle. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. Train-of-four recovery precedes twitch recovery during reversal with sugammadex in pediatric patients: A retrospective analysis.

    Science.gov (United States)

    Vieira Carlos, Ricardo; Luis Abramides Torres, Marcelo; de Boer, Hans Donald

    2018-04-01

    After reversal of a rocuronium-induced neuromuscular blockade with sugammadex, the recovery of train-of-four ratio to 0.9 is faster than recovery of first twitch of the train-of-four to 90% in adults. These findings after reversal of neuromuscular blockade with sugammadex have not yet been investigated in pediatric patients. The aim of this retrospective analysis was to investigate the relationship of the recovery of first twitch of the train-of-four height and train-of-four ratio after reversal of rocuronium-induced neuromuscular blockade with sugammadex in pediatric patients. Patients ASA I-III, aged 2-11 years, and who underwent abdominal and/or perineal surgery were included in the analysis. After extracting the necessary data from the hospital database, the patients were divided into 2 groups based on the dose of sugammadex received: group A: 2 mg.kg -1 for reversal of moderate neuromuscular blockade and group B: 4 mg.kg -1 for reversal of deep neuromuscular blockade. The relationship of the recovery of first twitch of the train-of-four height and train-of-four ratio in these 2 groups were analyzed. Data from 43 pediatric patients aged 2-11 years could be analyzed. The first twitch of the train-of-four height at the recovery of train-of-four ratio to 0.9 in group B was statistically significantly lower compared with group A. This height 3 and 5 minutes after the train-of-four ratio reached 0.9 showed no statistically significant differences between groups. The results were in line with the results found in adults and showed that the train-of-four ratio recovered to 0.9 was faster than first twitch of the train-of-four height recovered to the same level. © 2018 John Wiley & Sons Ltd.

  13. Reduced phrenic motoneuron recruitment during sustained inspiratory threshold loading compared to single-breath loading: a twitch interpolation study

    Directory of Open Access Journals (Sweden)

    Mathieu Raux

    2016-11-01

    Full Text Available In humans, inspiratory constraints engage cortical networks involving the supplementary motor area. Functional magnetic resonance imaging (fMRI shows that the spread and intensity of the corresponding respiratory-related cortical activation dramatically decrease when a discrete load becomes sustained. This has been interpreted as reflecting motor cortical reorganisation and automatisation, but could proceed from sensory and/or affective habituation. To corroborate the existence of motor reorganisation between single-breath and sustained inspiratory loading (namely changes in motor neurones recruitment, we conducted a diaphragm twitch interpolation study based on the hypothesis that motor reorganisation should result in changes in the twitch interpolation slope. Fourteen healthy subjects (age: 21 – 40 years were studied. Bilateral phrenic stimulation was delivered at rest, upon prepared and targeted voluntary inspiratory efforts (vol, upon unprepared inspiratory efforts against a single-breath inspiratory threshold load (single-breath, and upon sustained inspiratory efforts against the same type of load (continuous. The slope of the relationship between diaphragm twitch transdiaphragmatic pressure and the underlying transdiaphragmatic pressure was –1.1 ± 0.2 during vol, –1.5 ± 0.7 during single-breath, and -0.6 ± 0.4 during continuous (all slopes expressed in percent of baseline.percent of baseline-1 all comparisons significant at the 5% level. The contribution of the diaphragm to inspiration, as assessed by the gastric pressure to transdiaphragmatic pressure ratio, was 31 ± 17 % during vol, 22 ± 16 % during single-breath (p=0.13, and 19 ± 9 % during continuous (p = 0.0015 vs. vol. This study shows that the relationship between the amplitude of the transdiaphragmatic pressure produced by a diaphragm twitch and its counterpart produced by the underlying diaphragm contraction is not unequivocal. If twitch interpolation is interpreted as

  14. Dithiothreitol activation of the insulin receptor/kinase does not involve subunit dissociation of the native α2β2 insulin receptor subunit complex

    International Nuclear Information System (INIS)

    Sweet, L.J.; Wilden, P.A.; Pessin, J.E.

    1986-01-01

    The subunit composition of the dithiothreitol- (DTT) activated insulin receptor/kinase was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and gel filtration chromatography under denaturing or nondenaturing conditions. Pretreatment of 32 P-labeled insulin receptors with 50 mM DTT followed by gel filtration chromatography in 0.1% SDS demonstrated the dissociation of the α 2 β 2 insulin receptor complex (M/sub r/ 400,000) into the monomeric 95,000 β subunit. In contrast, pretreatment of the insulin receptors with 1-50 mM DTT followed by gel filtration chromatography in 0.1% Triton X-100 resulted in no apparent alteration in mobility compared to the untreated insulin receptors. Resolution of this complex by nonreducing SDS-polyacrylamide gel electrophoresis and autoradiography demonstrated the existence of the α 2 β 2 heterotetrameric complex with essentially no αβ heterodimeric or free monomeric β subunit species present. This suggests that the insulin receptor can reoxidize into the M/sub r/ 400,000 complex after the removal of DTT by gel filtration chromatography. To prevent reoxidation, the insulin receptors were pretreated with 50 mM DTT. Under the conditions the insulin receptors migrated as the M/sub r/ 400,000 α 2 β 2 complex. These results demonstrate that treatment of the insulin receptors with high concentrations of DTT, followed by removal of DTT by gel filtration, results in reoxidation of the reduced α 2 β 2 insulin receptor complex. Further, these results document that although the DTT stimulation of the insulin receptor/kinase does involve reduction of the insulin receptor subunits, it does not result in dissociation of the native α 2 β 2 insulin receptor subunit complex

  15. Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans

    DEFF Research Database (Denmark)

    Krustrup, Peter; Secher, Niels; Relu, Mihai U.

    2008-01-01

    We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W...... without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P fibres, whereas in CON, CP decreased (P ... at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation....

  16. Juxtaposition of the changes in intracellular calcium and force during staircase potentiation at 30 and 37°C

    Science.gov (United States)

    Vandenboom, Rene

    2014-01-01

    Ca2+ entry during the action potential stimulates muscle contraction. During repetitive low frequency stimulation, skeletal muscle undergoes staircase potentiation (SP), a progressive increase in the peak twitch force induced by each successive stimulus. Multiple mechanisms, including myosin regulatory light chain phosphorylation, likely contribute to SP, a temperature-dependent process. Here, we used the Ca2+-sensitive fluorescence indicators acetoxymethyl (AM)-furaptra and AM-fura-2 to examine the intracellular Ca2+ transient (ICT) and the baseline Ca2+ level at the onset of each ICT during SP at 30 and 37°C in mouse lumbrical muscle. The stimulation protocol, 8 Hz for 8 s, resulted in a 27 ± 3% increase in twitch force at 37°C and a 7 ± 2% decrease in twitch force at 30°C (P < 0.05). Regardless of temperature, the peak rate of force production (+df/dt) was higher in all twitches relative to the first twitch (P < 0.05). Consistent with the differential effects of stimulation on twitch force at the two temperatures, raw ICT amplitude decreased during repetitive stimulation at 30°C (P < 0.05) but not at 37°C. Cytosolic Ca2+ accumulated during SP such that baseline Ca2+ at the onset of ICTs occurring late in the train was higher (P < 0.05) than that of those occurring early in the train. ICT duration increased progressively at both temperatures. This effect was not entirely proportional to the changes in twitch duration, as twitch duration characteristically decreased before increasing late in the protocol. This is the first study identifying a changing ICT as an important, and temperature-sensitive, modulator of muscle force during repetitive stimulation. Moreover, we extend previous observations by demonstrating that contraction-induced increases in baseline Ca2+ coincide with greater +df/dt but not necessarily with higher twitch force. PMID:25422504

  17. American football and other sports injuries may cause migraine/persistent pain decades later and can be treated successfully with electrical twitch-obtaining intramuscular stimulation (ETOIMS).

    Science.gov (United States)

    Chu, J; McNally, S; Bruyninckx, F; Neuhauser, D

    2017-04-01

    Autonomous twitch elicitation at myofascial trigger points from spondylotic radiculopathies-induced denervation supersensitivity can provide favourable pain relief using electrical twitch-obtaining intramuscular stimulation (ETOIMS). To provide objective evidence that ETOIMS is safe and efficacious in migraine and persistent pain management due to decades-old injuries to head and spine from paediatric American football. An 83-year-old mildly hypertensive patient with 25-year history of refractory migraine and persistent pain self-selected to regularly receive fee-for-service ETOIMS 2/week over 20 months. He had 180 sessions of ETOIMS. Pain levels, blood pressure (BP) and heart rate/pulse were recorded before and immediately after each treatment alongside highest level of clinically elicitable twitch forces/session, session duration and intervals between treatments. Twitch force grades recorded were from 1 to 5, grade 5 twitch force being strongest. Initially, there was hypersensitivity to electrical stimulation with low stimulus parameters (500 µs pulse-width, 30 mA stimulus intensity, frequency 1.3 Hz). This resolved with gradual stimulus increments as tolerated during successive treatments. By treatment 27, autonomous twitches were noted. Spearman's correlation coefficients showed that pain levels are negatively related to twitch force, number of treatments, treatment session duration and directly related to BP and heart rate/pulse. Treatment numbers and session durations directly influence twitch force. At end of study, headaches and quality of life improved, hypertension resolved and antihypertensive medication had been discontinued. Using statistical process control methodology in an individual patient, we showed long-term safety and effectiveness of ETOIMS in simultaneous diagnosis, treatment, prognosis and prevention of migraine and persistent pain in real time obviating necessity for randomised controlled studies.

  18. Observation of the molecular organization of calcium release sites in fast- and slow-twitch skeletal muscle with nanoscale imaging

    OpenAIRE

    Jayasinghe, Isuru D.; Munro, Michelle; Baddeley, David; Launikonis, Bradley S.; Soeller, Christian

    2014-01-01

    Localization microscopy is a fairly recently introduced super-resolution fluorescence imaging modality capable of achieving nanometre-scale resolution. We have applied the dSTORM variation of this method to image intracellular molecular assemblies in skeletal muscle fibres which are large cells that critically rely on nanoscale signalling domains, the triads. Immunofluorescence staining in fixed adult rat skeletal muscle sections revealed clear differences between fast- and slow-twitch fibres...

  19. Properties of slow- and fast-twitch muscle fibres in a mouse model of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Atkin, Julie D; Scott, Rachel L; West, Jan M; Lopes, Elizabeth; Quah, Alvin K J; Cheema, Surindar S

    2005-05-01

    This investigation was undertaken to determine if there are altered histological, pathological and contractile properties in presymptomatic or endstage diseased muscle fibres from representative slow-twitch and fast-twitch muscles of SOD1 G93A mice in comparison to wildtype mice. In presymptomatic SOD1 G93A mice, there was no detectable peripheral dysfunction, providing evidence that muscle pathology is secondary to motor neuronal dysfunction. At disease endstage however, single muscle fibre contractile analysis demonstrated that fast-twitch muscle fibres and neuromuscular junctions are preferentially affected by amyotrophic lateral sclerosis-induced denervation, being unable to produce the same levels of force when activated by calcium as muscle fibres from their age-matched controls. The levels of transgenic SOD1 expression, aggregation state and activity were also examined in these muscles but there no was no preference for muscle fibre type. Hence, there is no simple correlation between SOD1 protein expression/activity, and muscle fibre type vulnerability in SOD1 G93A mice.

  20. Sarcoplasmic reticulum function in slow- and fast-twitch skeletal muscles from mdx mice.

    Science.gov (United States)

    Divet, Alexandra; Huchet-Cadiou, Corinne

    2002-08-01

    The aim of the present study was to establish whether alterations in sarcoplasmic reticulum function are involved in the abnormal Ca(2+) homeostasis of skeletal muscle in mice with muscular dystrophy ( mdx). The properties of the sarcoplasmic reticulum and contractile proteins of fast- and slow-twitch muscles were therefore investigated in chemically skinned fibres isolated from the extensor digitorum longus (EDL) and soleus muscles of normal (C57BL/10) and mdx mice at 4 and 11 weeks of development. Sarcoplasmic reticulum Ca(2+) uptake, estimated by the Ca(2+) release following exposure to caffeine, was significantly slower in mdx mice, while the maximal Ca(2+) quantity did not differ in either type of skeletal muscle at either stage of development. In 4-week-old mice spontaneous sarcoplasmic reticulum Ca(2+) leakage was observed in EDL and soleus fibres and this was more pronounced in mdx mice. In addition, the maximal Ca(2+)-activated tension was smaller in mdx than in normal fibres, while the Ca(2+) sensitivity of the contractile apparatus was not significantly different. These results indicate that mdx hindlimb muscles are affected differently by the disease process and suggest that a reduced ability of the Ca(2+)-ATPase to load Ca(2+) and a leaky sarcoplasmic reticulum membrane may be involved in the altered intracellular Ca(2+) homeostasis.

  1. Dysregulated corticostriatal activity in open-field behavior and the head-twitch response induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine.

    Science.gov (United States)

    Rangel-Barajas, Claudia; Estrada-Sánchez, Ana María; Barton, Scott J; Luedtke, Robert R; Rebec, George V

    2017-02-01

    The substituted amphetamine, 2,5-dimethoxy-4-iodoamphetamine (DOI), is a hallucinogen that has been used to model a variety of psychiatric conditions. Here, we studied the effect of DOI on neural activity recorded simultaneously in the primary motor cortex (M1) and dorsal striatum of freely behaving FvB/N mice. DOI significantly decreased the firing rate of individually isolated neurons in M1 and dorsal striatum relative to pre-drug baseline. It also induced a bursting pattern of activity by increasing both the number of spikes within a burst and burst duration. In addition, DOI increased coincident firing between simultaneously recorded neuron pairs within the striatum and between M1 and dorsal striatum. Local field potential (LFP) activity also increased in coherence between M1 and dorsal striatum after DOI in the low frequency gamma band (30-50 Hz), while corticostriatal coherence in delta, theta, alpha, and beta activity decreased. We also assessed corticostriatal LFP activity in relation to the DOI-induced head-twitch response (HTR), a readily identifiable behavior used to assess potential treatments for the conditions it models. The HTR was associated with increased delta and decreased theta power in both M1 and dorsal striatum. Together, our results suggest that DOI dysregulates corticostriatal communication and that the HTR is associated with this dysregulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Calcium Increases Xylella fastidiosa Surface Attachment, Biofilm Formation, and Twitching Motility

    Science.gov (United States)

    Cruz, Luisa F.; Cobine, Paul A.

    2012-01-01

    Xylella fastidiosa is a plant-pathogenic bacterium that forms biofilms inside xylem vessels, a process thought to be influenced by the chemical composition of xylem sap. In this work, the effect of calcium on the production of X. fastidiosa biofilm and movement was analyzed under in vitro conditions. After a dose-response study with 96-well plates using eight metals, the strongest increase of biofilm formation was observed when medium was supplemented with at least 1.0 mM CaCl2. The removal of Ca by extracellular (EGTA, 1.5 mM) and intracellular [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA/AM), 75 μM] chelators reduced biofilm formation without compromising planktonic growth. The concentration of Ca influenced the force of adhesion to the substrate, biofilm thickness, cell-to-cell aggregation, and twitching motility, as shown by assays with microfluidic chambers and other assays. The effect of Ca on attachment was lost when cells were treated with tetracycline, suggesting that Ca has a metabolic or regulatory role in cell adhesion. A double mutant (fimA pilO) lacking type I and type IV pili did not improve biofilm formation or attachment when Ca was added to the medium, while single mutants of type I (fimA) or type IV (pilB) pili formed more biofilm under conditions of higher Ca concentrations. The concentration of Ca in the medium did not significantly influence the levels of exopolysaccharide produced. Our findings indicate that the role of Ca in biofilm formation may be related to the initial surface and cell-to-cell attachment and colonization stages of biofilm establishment, which rely on critical functions by fimbrial structures. PMID:22194297

  3. Attenuated fatigue in slow twitch skeletal muscle during isotonic exercise in rats with chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Morten Munkvik

    Full Text Available During isometric contractions, slow twitch soleus muscles (SOL from rats with chronic heart failure (chf are more fatigable than those of sham animals. However, a muscle normally shortens during activity and fatigue development is highly task dependent. Therefore, we examined the development of skeletal muscle fatigue during shortening (isotonic contractions in chf and sham-operated rats. Six weeks following coronary artery ligation, infarcted animals were classified as failing (chf if left ventricle end diastolic pressure was >15 mmHg. During isoflurane anaesthesia, SOL with intact blood supply was stimulated (1s on 1s off at 30 Hz for 15 min and allowed to shorten isotonically against a constant afterload. Muscle temperature was maintained at 37°C. In resting muscle, maximum isometric force (F(max and the concentrations of ATP and CrP were not different in the two groups. During stimulation, F(max and the concentrations declined in parallel sham and chf. Fatigue, which was evident as reduced shortening during stimulation, was also not different in the two groups. The isometric force decline was fitted to a bi-exponential decay equation. Both time constants increased transiently and returned to initial values after approximately 200 s of the fatigue protocol. This resulted in a transient rise in baseline tension between stimulations, although this effect which was less prominent in chf than sham. Myosin light chain 2s phosphorylation declined in both groups after 100 s of isotonic contractions, and remained at this level throughout 15 min of stimulation. In spite of higher energy demand during isotonic than isometric contractions, both shortening capacity and rate of isometric force decline were as well or better preserved in fatigued SOL from chf rats than in sham. This observation is in striking contrast to previous reports which have employed isometric contractions to induce fatigue.

  4. Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling.

    Science.gov (United States)

    Raffaello, Anna; Laveder, Paolo; Romualdi, Chiara; Bean, Camilla; Toniolo, Luana; Germinario, Elena; Megighian, Aram; Danieli-Betto, Daniela; Reggiani, Carlo; Lanfranchi, Gerolamo

    2006-03-13

    Denervation deeply affects muscle structure and function, the alterations being different in slow and fast muscles. Because the effects of denervation on fast muscles are still controversial, and high-throughput studies on gene expression in denervated muscles are lacking, we studied gene expression during atrophy progression following denervation in mouse tibialis anterior (TA). The sciatic nerve was cut close to trochanter in adult CD1 mice. One, three, seven, and fourteen days after denervation, animals were killed and TA muscles were dissected out and utilized for physiological experiments and gene expression studies. Target cDNAs from TA muscles were hybridized on a dedicated cDNA microarray of muscle genes. Seventy-one genes were found differentially expressed. Microarray results were validated, and the expression of relevant genes not probed on our array was monitored by real-time quantitative PCR (RQ-PCR). Nuclear- and mitochondrial-encoded genes implicated in energy metabolism were consistently downregulated. Among genes implicated in muscle contraction (myofibrillar and sarcoplasmic reticulum), genes typical of fast fibers were downregulated, whereas those typical of slow fibers were upregulated. Electrophoresis and Western blot showed less pronounced changes in myofibrillar protein expression, partially confirming changes in gene expression. Isometric tension of skinned fibers was little affected by denervation, whereas calcium sensitivity decreased. Functional studies in mouse extensor digitorum longus muscle showed prolongation in twitch time parameters and shift to the left in force-frequency curves after denervation. We conclude that, if studied at the mRNA level, fast muscles appear not less responsive than slow muscles to the interruption of neural stimulation.

  5. Swimming, swarming, twitching, and chemotactic responses of Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 in the presence of cadmium.

    Science.gov (United States)

    Shamim, Saba; Rehman, Abdul; Qazi, Mahmood Hussain

    2014-04-01

    To use of microorganisms for bioremediation purposes, the study of their motility behavior toward metals is essential. In the present study, Cupriavidus metallidurans CH34 and Pseudomonas putida mt2 were used as cadmium (Cd)-resistant and -sensitive bacteria, respectively, to evaluate the effects of Cd on their motility behaviors. Potassium morpholinopropane sulfonate (MOPS) buffer was used to observe the motility behavior of both isolates. Movement of mt2 was less in MOPS buffer compared with CH34, likely reflecting the mono-flagellated nature of mt2 and the peritrichous nature of CH34. The swimming, swarming, twitching, and chemotaxis behaviors of mt2 were greater in the presence of glucose than that of Cd. mt2 exhibited negative motility behaviors when exposed to Cd, but the opposite effect was seen in CH34. Cd was found to be a chemorepellent for mt2 but a chemoattractant for CH34, suggesting that CH34 is a potential candidate for metal (Cd) bioremediation.

  6. Autonomic components of Complex Regional Pain Syndrome (CRPS) are favourably affected by Electrical Twitch-Obtaining Intramuscular Stimulation (ETOIMS): effects on blood pressure and heart rate.

    Science.gov (United States)

    Chu, Jennifer; Bruyninckx, Frans; Neuhauser, Duncan V

    2017-07-01

    Favourable pain relief results on evoking autonomous twitches at myofascial trigger points with Electrical Twitch Obtaining Intramuscular Stimulation (ETOIMS). To document autonomic nervous system (ANS) dysfunction in Complex Regional Pain Syndrome (CRPS) from blood pressure (BP) and pulse/heart rate changes with ETOIMS. A patient with persistent pain regularly received serial ETOIMS sessions of 60, 90, 120 or ≥150 min over 24 months. Outcome measures include BP: systolic, diastolic, pulse pressure and pulse/heart rate, pre-session/immediate-post-session summed differences (SDPPP index), and pain reduction. His results were compared with that of two other patients and one normal control. Each individual represented the following maximal elicitable twitch forces (TWF) graded 1-5: maximum TWF2: control subject; maximum TWF3: CRPS patient with suspected ANS dysfunction; and maximum TWF4 and TWF5: two patients with respective slow-fatigue and fast-fatigue twitches who during ETOIMS had autonomous twitching at local and remote myotomes simultaneously from denervation supersensitivity. ETOIMS results between TWFs were compared using one-way analysis of variance test. The patients showed immediate significant pain reduction, BP and pulse/heart rate changes/reduction(s) except for diastolic BP in the TWF5 patient. TWF2 control subject had diastolic BP reduction with ETOIMS but not with rest. Linear regression showed TWF grade to be the most significant variable in pain reduction, more so than the number of treatments, session duration and treatment interval. TWF grade was the most important variable in significantly reducing outcome measures, especially pulse/heart rate. Unlike others, the TWF3 patient had distinctive reductions in SDPPP index. Measuring BP and pulse/heart rate is clinically practical for alerting ANS dysfunction maintained CRPS. SDPPP index (≥26) and pulse/heart rate (≥8) reductions with almost every ETOIMS treatment, plus inability to evoke

  7. EXERCISE, MANUAL THERAPY AND POSTURAL RE-EDUCATION FOR UNCONTROLLED EAR TWITCHING AND RELATED IMPAIRMENTS AFTER WHIPLASH INJURY: A CASE REPORT.

    Science.gov (United States)

    Flanders, Kelsey; Feldner, Heather

    2017-10-01

    Whiplash Associated Disorders and the interventions used to remediate them are well documented in physical therapy literature. However, specific interventions for spasms of the neck musculature that also involve constant ear twitching have yet to be addressed. The purpose of this case report is twofold. First, to describe comprehensive physical therapy management and outcomes for a subject with uncontrolled ear twitching and related musculoskeletal impairments, and second, to discuss the physical therapist's approach to evidence-based care when faced with a paucity of literature addressing physical therapy interventions for subjects with uncontrolled ear twitching. The subject was a 14-year-old female who sustained a right anterolateral whiplash injury when struck in the head by a volleyball seven months prior to physical therapy. Beginning five months after that injury, she experienced uncontrolled and constant superior/inferior movement of her right ear (hereafter described in this report as a twitch) in addition to facial and cervical pain from her initial injury. She was unable to participate in high school athletics due to her pain. A multimodal treatment approach including exercise, manual therapy, and postural reeducation was utilized during the subject's episode of care. After eight treatment sessions, the subjects's cervical range of motion and upper extremity strength improved. The reported frequency of ear twitching decreased, as did reports of neck and shoulder pain. In addition, her Neck Disability Index improved from a score of 22, indicating moderate disability, to 9, indicating mild disability and she was able to return to sport activity. With limited research to direct intervention, clinical reasoning was utilized to formulate an effective therapeutic intervention. A combination of manual therapy, exercise, and postural reeducation intervention was effective for this subject and could assist in guiding interventions for similarly unique clinical

  8. Type IV Pili are required for virulence, twitching motility, and biofilm formation of acidovorax avenae subsp. Citrulli.

    Science.gov (United States)

    Bahar, Ofir; Goffer, Tal; Burdman, Saul

    2009-08-01

    Acidovorax avenae subsp. citrulli is the causal agent of bacterial fruit blotch (BFB), a threatening disease of watermelon, melon, and other cucurbits. Despite the economic importance of BFB, relatively little is known about basic aspects of the pathogen's biology and the molecular basis of its interaction with host plants. To identify A. avenae subsp. citrulli genes associated with pathogenicity, we generated a transposon (Tn5) mutant library on the background of strain M6, a group I strain of A. avenae subsp. citrulli, and screened it for reduced virulence by seed-transmission assays with melon. Here, we report the identification of a Tn5 mutant with reduced virulence that is impaired in pilM, which encodes a protein involved in assembly of type IV pili (TFP). Further characterization of this mutant revealed that A. avenae subsp. citrulli requires TFP for twitching motility and wild-type levels of biofilm formation. Significant reductions in virulence and biofilm formation as well as abolishment of twitching were also observed in insertional mutants affected in other TFP genes. We also provide the first evidence that group I strains of A. avenae subsp. citrulli can colonize and move through host xylem vessels.

  9. Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans.

    Science.gov (United States)

    Krustrup, Peter; Secher, Niels H; Relu, Mihai U; Hellsten, Ylva; Söderlund, Karin; Bangsbo, Jens

    2008-12-15

    We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P fibres, whereas in CON, CP decreased (P fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P muscle VO2 response was slower (P muscle homogenate CP was lowered (P muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

  10. In situ hybridisation of a large repertoire of muscle-specific transcripts in fish larvae: the new superficial slow-twitch fibres exhibit characteristics of fast-twitch differentiation.

    Science.gov (United States)

    Chauvigné, F; Ralliere, C; Cauty, C; Rescan, P Y

    2006-01-01

    Much of the present information on muscle differentiation in fish concerns the early embryonic stages. To learn more about the maturation and the diversification of the fish myotomal fibres in later stages of ontogeny, we investigated, by means of in situ hybridisation, the developmental expression of a large repertoire of muscle-specific genes in trout larvae from hatching to yolk resorption. At hatching, transcripts for fast and slow muscle protein isoforms, namely myosins, tropomyosins, troponins and myosin binding protein C were present in the deep fast and the superficial slow areas of the myotome, respectively. During myotome expansion that follows hatching, the expression of fast isoforms became progressively confined to the borders of the fast muscle mass, whereas, in contrast, slow muscle isoform transcripts were uniformly expressed in all the slow fibres. Transcripts for several enzymes involved in oxidative metabolism such as citrate synthase, cytochrome oxidase component IV and succinate dehydrogenase, were present throughout the whole myotome of hatching embryos but in later stages became concentrated in slow fibre as well as in lateral fast fibres. Surprisingly, the slow fibres that are added externally to the single superficial layer of the embryonic (original) slow muscle fibres expressed not only slow twitch muscle isoforms but also, transiently, a subset of fast twitch muscle isoforms including MyLC1, MyLC3, MyHC and myosin binding protein C. Taken together these observations show that the growth of the myotome of the fish larvae is associated with complex patterns of muscular gene expression and demonstrate the unexpected presence of fast muscle isoform-expressing fibres in the most superficial part of the slow muscle.

  11. Expression of multiple slow myosin heavy chain genes reveals a diversity of zebrafish slow twitch muscle fibres with differing requirements for Hedgehog and Prdm1 activity.

    Science.gov (United States)

    Elworthy, Stone; Hargrave, Murray; Knight, Robert; Mebus, Katharina; Ingham, Philip W

    2008-06-01

    The zebrafish embryo develops a series of anatomically distinct slow twitch muscle fibres that characteristically express genes encoding lineage-specific isoforms of sarcomeric proteins such as MyHC and troponin. We show here that different subsets of these slow fibres express distinct members of a tandem array of slow MyHC genes. The first slow twitch muscle fibres to differentiate, which are specified by the activity of the transcription factor Prdm1 (also called Ubo or Blimp1) in response to Hedgehog (Hh) signalling, express the smyhc1 gene. Subsequently, secondary slow twitch fibres differentiate in most cases independently of Hh activity. We find that although some of these later-forming fibres also express smyhc1, others express smyhc2 or smyhc3. We show that the smyhc1-positive fibres express the ubo (prdm1) gene and adopt fast twitch fibre characteristics in the absence of Prdm1 activity, whereas those that do not express smyhc1 can differentiate independently of Prdm1 function. Conversely, some smyhc2-expressing fibres, although independent of Prdm1 function, require Hh activity to form. The adult trunk slow fibres express smyhc2 and smyhc3, but lack smyhc1 expression. The different slow fibres in the craniofacial muscles variously express smyhc1, smyhc2 and smyhc3, and all differentiate independently of Prdm1.

  12. Inositol 1,4,5-trisphosphate-sensitive Ca2+ release in rat fast- and slow-twitch skinned muscle fibres.

    Science.gov (United States)

    Talon, S; Huchet-Cadiou, C; Léoty, C

    1999-11-01

    Inositol 1,4,5-trisphosphate (InsP3), an intracellular messenger, induces Ca2+ release in various types of cells, particularly smooth muscle cells. Its role in skeletal muscle, however, is controversial. The present study shows that the application of InsP3 to rat slow- and fast-twitch saponin-skinned fibres induced contractile responses that were not related to an effect of InsP3 on the properties of the contractile proteins. The amplitude of the contractures was dependent upon the Ca(2+)-loading period, and was larger in slow- than in fast-twitch muscle. In both types of skeletal muscle, these responses, unlike caffeine contractures, were not inhibited by ryanodine (100 microM), but were abolished by heparin (20 micrograms.ml-1). In soleus muscle, the concentration of heparin required to inhibit the response by 50% (IC50) was 5.7 micrograms.ml-1, a similar value to that obtained previously in smooth muscle. Furthermore, the results show that in slow-twitch muscle, the InsP3 contractures have a "bell-shaped" dependency on the intracellular Ca2+ concentration. These results show that InsP3 receptors should be present in skeletal muscle. Thus, it is possible that InsP3 participates in the regulation of sarcoplasmic reticulum Ca2+ release in skeletal muscle, particularly in slow-twitch fibres.

  13. A quantitative description of tubular system Ca2+ handling in fast‐ and slow‐twitch muscle fibres

    Science.gov (United States)

    Cully, Tanya R.; Edwards, Joshua N.; Murphy, Robyn M.

    2016-01-01

    Key points Current methods do not allow a quantitative description of Ca2+ movements across the tubular (t‐) system membrane without isolating the membranes from their native skeletal muscle fibre.Here we present a fluorescence‐based method that allows determination of the t‐system [Ca2+] transients and derivation of t‐system Ca2+ fluxes in mechanically skinned skeletal muscle fibres. Differences in t‐system Ca2+‐handling properties between fast‐ and slow‐twitch fibres from rat muscle are resolved for the first time using this new technique.The method can be used to study Ca2+ handling of the t‐system and allows direct comparisons of t‐system Ca2+ transients and Ca2+ fluxes between groups of fibres and fibres from different strains of animals. Abstract The tubular (t‐) system of skeletal muscle is an internalization of the plasma membrane that maintains a large Ca2+ gradient and exchanges Ca2+ between the extracellular and intracellular environments. Little is known of the Ca2+‐handling properties of the t‐system as the small Ca2+ fluxes conducted are difficult to resolve with conventional methods. To advance knowledge in this area we calibrated t‐system‐trapped rhod‐5N inside skinned fibres from rat and [Ca2+]t‐sys, allowing confocal measurements of Ca2+‐dependent changes in rhod‐5N fluorescence during rapid changes in the intracellular ionic environment to be converted to [Ca2+] transients in the t‐system ([Ca2+]t‐sys (t)). Furthermore, t‐system Ca2+‐buffering power was determined so that t‐system Ca2+ fluxes could be derived from [Ca2+]t‐sys (t). With this new approach, we show that rapid depletion of sarcoplasmic reticulum (SR) Ca2+ induced a robust store‐operated Ca2+ entry (SOCE) in fast‐ and slow‐twitch fibres, reducing [Ca2+]t‐sys to fibre types. Abruptly introducing internal solutions with 1 mm Mg2+ and [Ca2+]cyto (28 nm–1.3 μm) to Ca2+‐depleted fibres generated t‐system Ca2+ uptake rates

  14. A quantitative description of tubular system Ca(2+) handling in fast- and slow-twitch muscle fibres.

    Science.gov (United States)

    Cully, Tanya R; Edwards, Joshua N; Murphy, Robyn M; Launikonis, Bradley S

    2016-06-01

    Current methods do not allow a quantitative description of Ca(2+) movements across the tubular (t-) system membrane without isolating the membranes from their native skeletal muscle fibre. Here we present a fluorescence-based method that allows determination of the t-system [Ca(2+) ] transients and derivation of t-system Ca(2+) fluxes in mechanically skinned skeletal muscle fibres. Differences in t-system Ca(2+) -handling properties between fast- and slow-twitch fibres from rat muscle are resolved for the first time using this new technique. The method can be used to study Ca(2+) handling of the t-system and allows direct comparisons of t-system Ca(2+) transients and Ca(2+) fluxes between groups of fibres and fibres from different strains of animals. The tubular (t-) system of skeletal muscle is an internalization of the plasma membrane that maintains a large Ca(2+) gradient and exchanges Ca(2+) between the extracellular and intracellular environments. Little is known of the Ca(2+) -handling properties of the t-system as the small Ca(2+) fluxes conducted are difficult to resolve with conventional methods. To advance knowledge in this area we calibrated t-system-trapped rhod-5N inside skinned fibres from rat and [Ca(2+) ]t-sys , allowing confocal measurements of Ca(2+) -dependent changes in rhod-5N fluorescence during rapid changes in the intracellular ionic environment to be converted to [Ca(2+) ] transients in the t-system ([Ca(2+) ]t-sys (t)). Furthermore, t-system Ca(2+) -buffering power was determined so that t-system Ca(2+) fluxes could be derived from [Ca(2+) ]t-sys (t). With this new approach, we show that rapid depletion of sarcoplasmic reticulum (SR) Ca(2+) induced a robust store-operated Ca(2+) entry (SOCE) in fast- and slow-twitch fibres, reducing [Ca(2+) ]t-sys to fibre types. Abruptly introducing internal solutions with 1 mm Mg(2+) and [Ca(2+) ]cyto (28 nm-1.3 μm) to Ca(2+) -depleted fibres generated t-system Ca(2+) uptake rates dependent on [Ca(2

  15. Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

    Science.gov (United States)

    Barclay, C J

    2012-12-01

    The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

  16. Altered fast- and slow-twitch muscle fibre characteristics in female mice with a (S248F) knock-in mutation of the brain neuronal nicotinic acetylcholine receptor.

    Science.gov (United States)

    Cannata, David J; Finkelstein, David I; Gantois, Ilse; Teper, Yaroslav; Drago, John; West, Jan M

    2009-01-01

    We generated a mouse line with a missense mutation (S248F) in the gene (CHRNA4) encoding the alpha4 subunit of neuronal nicotinic acetylcholine receptor (nAChR). Mutant mice demonstrate brief nicotine induced dystonia that resembles the clinical events seen in patients with the same mutation. Drug-induced dystonia is more pronounced in female mice, thus our aim was to determine if the S248F mutation changed the properties of fast- and slow-twitch muscle fibres from female mutant mice. Reverse transcriptase-PCR confirmed CHRNA4 gene expression in the brain but not skeletal muscles in normal and mutant mice. Ca(2+) and Sr(2+) force activation curves were obtained using skinned muscle fibres prepared from slow-twitch (soleus) and fast-twitch (EDL) muscles. Two significant results were found: (1) the (pCa(50) - pSr(50)) value from EDL fibres was smaller in mutant mice than in wild type (1.01 vs. 1.30), (2) the percentage force produced at pSr 5.5 was larger in mutants than in wild type (5.76 vs. 0.24%). Both results indicate a shift to slow-twitch characteristics in the mutant. This conclusion is supported by the identification of the myosin heavy chain (MHC) isoforms. Mutant EDL fibres expressed MHC I (usually only found in slow-twitch fibres) as well as MHC IIa. Despite the lack of spontaneous dystonic events, our findings suggest that mutant mice may be having subclinical events or the mutation results in a chronic alteration to muscle neural input.

  17. "Positive people always win" : en studie av hur kvinnor som livestreamar på Twitch.tv upplever interaktionen med sina tittare i kanalchatten

    OpenAIRE

    Thoresen, Josef; Elfwendahl, Sofia

    2017-01-01

    I denna studie har vi undersökt kvinnor som livestreamar sitt datorspelande på hemsidan Twitch.tv och deras erfarenheter gällande chattkommentarer på deras livesändningar. Vi har främst fokuserat på negativa chattkommentarer och hur dessa påverkar kvinnorna, då tidigare forskning redan har visat på att kvinnor utsätts för fler trakasserier än män, både generellt på internet och på Twitch.tv (Nakandala, Ciampaglia, Su & Ahn. 2016). Vidare ville vi också se hur kvinnorna hanterar dessa nega...

  18. Active site mutations in yeast protein disulfide isomerase cause dithiothreitol sensitivity and a reduced rate of protein folding in the endoplasmic reticulum

    DEFF Research Database (Denmark)

    Holst, B; Tachibana, C; Winther, Jakob R.

    1997-01-01

    Aspects of protein disulfide isomerase (PDI) function have been studied in yeast in vivo. PDI contains two thioredoxin-like domains, a and a', each of which contains an active-site CXXC motif. The relative importance of the two domains was analyzed by rendering each one inactive by mutation to SGAS....... Such mutations had no significant effect on growth. The domains however, were not equivalent since the rate of folding of carboxypeptidase Y (CPY) in vivo was reduced by inactivation of the a domain but not the a' domain. To investigate the relevance of PDI redox potential, the G and H positions of each CGHC......-deleted strains overexpressing the yeast PDI homologue EUG1 are viable. Exchanging the wild-type Eug1p C(L/I)HS active site sequences for C(L/I)HC increased the growth rate significantly, however, further highlighting the importance of the oxidizing function for optimal growth....

  19. Incubating Isolated Mouse EDL Muscles with Creatine Improves Force Production and Twitch Kinetics in Fatigue Due to Reduction in Ionic Strength

    Science.gov (United States)

    Head, Stewart I.; Greenaway, Bronwen; Chan, Stephen

    2011-01-01

    Background Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. Methods and Results The extensor digitorum longus muscle from mice aged 12–14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i) before fatigue; (ii) immediately after a fatigue protocol; and (iii) after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. Conclusion Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation. PMID:21850234

  20. Incubating isolated mouse EDL muscles with creatine improves force production and twitch kinetics in fatigue due to reduction in ionic strength.

    Directory of Open Access Journals (Sweden)

    Stewart I Head

    Full Text Available BACKGROUND: Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. METHODS AND RESULTS: The extensor digitorum longus muscle from mice aged 12-14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i before fatigue; (ii immediately after a fatigue protocol; and (iii after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. CONCLUSION: Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca(2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation.

  1. Partial fast-to-slow conversion of regenerating rat fast-twitch muscle by chronic low-frequency stimulation.

    Science.gov (United States)

    Pette, Dirk; Sketelj, Janez; Skorjanc, Dejan; Leisner, Elmi; Traub, Irmtrud; Bajrović, Fajko

    2002-01-01

    Chronic low-frequency stimulation (CLFS) of rat fast-twitch muscles induces sequential transitions in myosin heavy chain (MHC) expression from MHCIIb --> MHCIId/x --> MHCIIa. However, the 'final' step of the fast-to-slow transition, i.e., the upregulation of MHCI, has been observed only after extremely long stimulation periods. Assuming that fibre degeneration/regeneration might be involved in the upregulation of slow myosin, we investigated the effects of CLFS on extensor digitorum longus (EDL) muscles regenerating after bupivacaine-induced fibre necrosis. Normal, non-regenerating muscles responded to both 30- and 60-day CLFS with fast MHC isoform transitions (MHCIIb --> MHCIId --> MHCIIa) and only slight increases in MHCI. CLFS of regenerating EDL muscles caused similar transitions among the fast isoforms but, in addition, caused significant increases in MHCI (to approximately 30% relative concentration). Stimulation periods of 30 and 60 days induced similar changes in the regenerating bupivacaine-treated muscles, indicating that the upregulation of slow myosin was restricted to regenerating fibres, but only during an early stage of regeneration. These results suggest that satellite cells and/or regenerating fast rat muscle fibres are capable of switching directly to a slow program under the influence of CLFS and, therefore, appear to be more malleable than adult fibres.

  2. Percent voluntary inactivation and peak force predictions with the interpolated twitch technique in individuals with high ability of voluntary activation

    International Nuclear Information System (INIS)

    Herda, Trent J; Walter, Ashley A; Hoge, Katherine M; Stout, Jeffrey R; Costa, Pablo B; Ryan, Eric D; Cramer, Joel T

    2011-01-01

    The purpose of this study was to examine the sensitivity and peak force prediction capability of the interpolated twitch technique (ITT) performed during submaximal and maximal voluntary contractions (MVCs) in subjects with the ability to maximally activate their plantar flexors. Twelve subjects performed two MVCs and nine submaximal contractions with the ITT method to calculate percent voluntary inactivation (%VI). Additionally, two MVCs were performed without the ITT. Polynomial models (linear, quadratic and cubic) were applied to the 10–90% VI and 40–90% VI versus force relationships to predict force. Peak force from the ITT MVC was 6.7% less than peak force from the MVC without the ITT. Fifty-eight percent of the 10–90% VI versus force relationships were best fit with nonlinear models; however, all 40–90% VI versus force relationships were best fit with linear models. Regardless of the polynomial model or the contraction intensities used to predict force, all models underestimated the actual force from 22% to 28%. There was low sensitivity of the ITT method at high contraction intensities and the predicted force from polynomial models significantly underestimated the actual force. Caution is warranted when interpreting the % VI at high contraction intensities and predicted peak force from submaximal contractions

  3. Twitching motility of bacteria with type-IV pili: Fractal walks, first passage time, and their consequences on microcolonies

    Science.gov (United States)

    Bisht, Konark; Klumpp, Stefan; Banerjee, Varsha; Marathe, Rahul

    2017-11-01

    A human pathogen, Neisseria gonorrhoeae (NG), moves on surfaces by attaching and retracting polymeric structures called Type IV pili. The tug-of-war between the pili results in a two-dimensional stochastic motion called twitching motility. In this paper, with the help of real-time NG trajectories, we develop coarse-grained models for their description. The fractal properties of these trajectories are determined and their influence on first passage time and formation of bacterial microcolonies is studied. Our main observations are as follows: (i) NG performs a fast ballistic walk on small time scales and a slow diffusive walk over long time scales with a long crossover region; (ii) there exists a characteristic persistent length lp*, which yields the fastest growth of bacterial aggregates or biofilms. Our simulations reveal that lp*˜L0.6 , where L ×L is the surface on which the bacteria move; (iii) the morphologies have distinct fractal characteristics as a consequence of the ballistic and diffusive motion of the constituting bacteria.

  4. Interaction of Mechanical Load with Growth Hormone (GH) and Insulin-Like Growth Factor I (IGF-I) on Slow-Twitch Skeletal Muscle and Bone

    Science.gov (United States)

    Linderman, Jon K.; Gosselink, Kristin L.; Wang, Tommy J.; Mukku, Venkat R.; Grindeland, Richard E.

    1994-01-01

    Exogenous humoral growth factors, combined with increased mechanical loading, reportedly induce hypertrophy of fast-, but not slow-twitch skeletal muscles, and have little effect in attenuating atrophy of slow-twitch muscle associated with exposure to microgravity in animals with intact neuroendocrine systems. These observations suggest that anabolic adjuvants and muscle tension do not interact to stimulate growth or maintenance of slow-twitch skeletal muscle. The purpose of the present study was to determine whether a chronic increase in mechanical loading (synergistic ablation) or hindlimb unweighting (hindlimb suspension) interact with exogenous GH and IGF-I (Genentech, So San Francisco, CA) in the slow-twitch soleus muscles of female rats (approx. 250 g). Bilateral ablation of the plantaris and gastrocnemius muscles induced 38% and 40% increases in the absolute (mg/pair) and relative (mg/100 g body weight) weights of the soleus, respectively (p less than or = 0.05), in ambulatory rats. GH and IGF-I interacted with chronic loading to increase absolute soleus mass an additional 20% (p less than or = 0.05), and mixed and myofibrillar protein contents an additional 12% and 7%, respectively (NS). In contrast, hindlimb suspension (HLS) resulted in 20% and 18% decreases in the absolute and relative weights of the soleus, respectively (p less than or = 0.05); GH and IGF-I did not spare loss of soleus mass or protein content in HLS rats. HLS decreased tibial plate thickness approx. 11% (p less than or = 0.05), but not weights of the tibia or femus. GH and IGF-I increased tibial plate thickness approx. 30% (p less than or = 0.05), in ambulatory and HLS rats, and increased femur and tibial weights 12% (p less than or = 0.05) and 8% (NS), respectively, in ambulatory rats, but had no effect in HLS rats. Results of the present investigation suggest that GH and IGF-I can stimulate hypertrophy of slow-twitch skeletal muscle when chronically overloaded, but can also stimulate

  5. Temperature-dependent changes in the viscoelasticity of intact resting mammalian (rat) fast- and slow-twitch muscle fibres.

    Science.gov (United States)

    Mutungi, G; Ranatunga, K W

    1998-04-01

    1. The tension and sarcomere length responses induced by ramp stretches (at amplitudes of 1-3 % fibre length (Lo) and speeds of 0.01-12 Lo s-1) were examined at different temperatures (range, 10-35 degrees C) in resting intact muscle fibre bundles isolated from the soleus (a slow-twitch muscle) and extensor digitorum longus (a fast-twitch muscle) of the rat. Some observations are also presented on the effects of chemical skinning on passive viscoelasticity at 10 degrees C. 2. As previously reported, the tension response to a ramp stretch, in different preparations and under various conditions, could be resolved into a viscous (P1), a viscoelastic (P2) and an elastic (P3) component and showed characteristic differences between slow and fast muscle fibres. 3. Chemical skinning of the muscle fibres led to a decrease in the amplitude of all three tension components. However, the fast-slow fibre differences remained after skinning. For example, the viscosity coefficient derived from P1 tension data decreased from 0.84 +/- 0.06 before skinning to 0.44 +/- 0.06 kN s m-2 after skinning in fast fibres; the corresponding values in slow fibres were 2.1 +/- 0.08 and 0.87 +/- 0.09 kN s m-2, respectively. 4. Increasing the experimental temperature from 10 to 35 degrees C led to a decrease in all the tension components in both fast and slow muscle fibre bundles. The decrease of P1 (viscous) tension was such that the viscosity coefficient calculated using P1 data was reduced from 0.84 +/- 0.1 to 0.43 +/- 0.05 kN s m-2 in fast fibres and from 2.0 +/- 0.1 to 1.0 +/- 0.1 kN s m-2 in slow fibres (Q10 of approximately 1.3 in both). 5. In both fast and slow muscle fibre preparations, the plateau tension of the viscoelastic component (P2) decreased by 60-80 % as the temperature was increased from 10 to 35 degrees C giving P2 tension a Q10 of approximately 1.4 in slow fibres and approximately 1.7 in the fast fibres. Additionally, the relaxation time of the viscoelasticity decreased from

  6. Connexin 39.9 Protein Is Necessary for Coordinated Activation of Slow-twitch Muscle and Normal Behavior in Zebrafish*

    Science.gov (United States)

    Hirata, Hiromi; Wen, Hua; Kawakami, Yu; Naganawa, Yuriko; Ogino, Kazutoyo; Yamada, Kenta; Saint-Amant, Louis; Low, Sean E.; Cui, Wilson W.; Zhou, Weibin; Sprague, Shawn M.; Asakawa, Kazuhide; Muto, Akira; Kawakami, Koichi; Kuwada, John Y.

    2012-01-01

    In many tissues and organs, connexin proteins assemble between neighboring cells to form gap junctions. These gap junctions facilitate direct intercellular communication between adjoining cells, allowing for the transmission of both chemical and electrical signals. In rodents, gap junctions are found in differentiating myoblasts and are important for myogenesis. Although gap junctions were once believed to be absent from differentiated skeletal muscle in mammals, recent studies in teleosts revealed that differentiated muscle does express connexins and is electrically coupled, at least at the larval stage. These findings raised questions regarding the functional significance of gap junctions in differentiated muscle. Our analysis of gap junctions in muscle began with the isolation of a zebrafish motor mutant that displayed weak coiling at day 1 of development, a behavior known to be driven by slow-twitch muscle (slow muscle). We identified a missense mutation in the gene encoding Connexin 39.9. In situ hybridization found connexin 39.9 to be expressed by slow muscle. Paired muscle recordings uncovered that wild-type slow muscles are electrically coupled, whereas mutant slow muscles are not. The further examination of cellular activity revealed aberrant, arrhythmic touch-evoked Ca2+ transients in mutant slow muscle and a reduction in the number of muscle fibers contracting in response to touch in mutants. These results indicate that Connexin 39.9 facilitates the spreading of neuronal inputs, which is irregular during motor development, beyond the muscle cells and that gap junctions play an essential role in the efficient recruitment of slow muscle fibers. PMID:22075003

  7. Calcium currents in a fast-twitch skeletal muscle of the rat.

    Science.gov (United States)

    Donaldson, P L; Beam, K G

    1983-10-01

    Slow ionic currents were measured in the rat omohyoid muscle with the three-microelectrode voltage-clamp technique. Sodium and delayed rectifier potassium currents were blocked pharmacologically. Under these conditions, depolarizing test pulses elicited an early outward current, followed by a transient slow inward current, followed in turn by a late outward current. The early outward current appeared to be a residual delayed rectifier current. The slow inward current was identified as a calcium current on the basis that (a) its magnitude depended on extracellular calcium concentration, (b) it was blocked by the addition of the divalent cations cadmium or nickel, and reduced in magnitude by the addition of manganese or cobalt, and (c) barium was able to replace calcium as an inward current carrier. The threshold potential for inward calcium current was around -20 mV in 10mM extracellular calcium and about -35 mV in 2 mM calcium. Currents were net inward over part of their time course for potentials up to at least +30 mV. At temperatures of 20-26 degrees C, the peak inward current (at approximately 0 mV) was 139 +/- 14 microA/cm2 (mean +/- SD), increasing to 226 +/- 28 microA/cm2 at temperatures of 27-37 degrees C. The late outward current exhibited considerable fiber-to-fiber variability. In some fibers it was primarily a time-independent, nonlinear leakage current. In other fibers it was primarily a time-independent, nonlinear leakage current. In other fibers it appeared to be the sum of both leak and a slowly activated outward current. The rate of activation of inward calcium current was strongly temperature dependent. For example, in a representative fiber, the time-to-peak inward current for a +10-mV test pulse decreased from approximately 250 ms at 20 degrees C to 100 ms at 30 degrees C. At 37 degrees C, the time-to-peak current was typically approximately 25 ms. The earliest phase of activation was difficult to quantify because the ionic current was partially

  8. Altered myoplasmic Ca(2+) handling in rat fast-twitch skeletal muscle fibres during disuse atrophy.

    Science.gov (United States)

    Weiss, Norbert; Andrianjafiniony, Tina; Dupré-Aucouturier, Sylvie; Pouvreau, Sandrine; Desplanches, Dominique; Jacquemond, Vincent

    2010-03-01

    Calcium-dependent signalling pathways are believed to play an important role in skeletal muscle atrophy, but whether intracellular Ca(2+) homeostasis is affected in that situation remains obscure. We show here that there is a 20% atrophy of the fast-type flexor digitorum brevis (FDB) muscle in rats hind limb unloaded (HU) for 2 weeks, with no change in fibre type distribution. In voltage-clamp experiments, the amplitude of the slow Ca(2+) current was found similar in fibres from control and HU animals. In fibres loaded with the Ca(2+) dye indo-1, the value for the rate of [Ca(2+)] decay after the end of 5-100-ms-long voltage-clamp depolarisations from -80 to +10 mV was found to be 30-50% lower in fibres from HU animals. This effect was consistent with a reduced contribution of both saturable and non-saturable components of myoplasmic Ca(2+) removal. However, there was no change in the relative amount of parvalbumin, and type 1 sarco-endoplasmic reticulum Ca(2+)-ATPase was increased by a factor of three in the atrophied muscles. Confocal imaging of mitochondrial membrane potential showed that atrophied FDB fibres had significantly depolarized mitochondria as compared to control fibres. Depolarization of mitochondria in control fibres with carbonyl cyanide-p-trifluoromethoxyphenylhydrazone induced a slowing of the decay of [Ca(2+)] transients accompanied by an increase in resting [Ca(2+)] and a reduction of the peak amplitude of the transients. Overall results provide the first functional evidence for severely altered intracellular Ca(2+) removal capabilities in atrophied fast-type muscle fibres and highlight the possible contribution of reduced mitochondrial polarisation.

  9. Tetanic Ca2+ transient differences between slow- and fast-twitch mouse skeletal muscle fibres: a comprehensive experimental approach.

    Science.gov (United States)

    Calderón, Juan C; Bolaños, Pura; Caputo, Carlo

    2014-12-01

    One hundred and eighty six enzymatically dissociated murine muscle fibres were loaded with Mag-Fluo-4 AM, and adhered to laminin, to evaluate the effect of modulating cytosolic Ca(2+) buffers and sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA), mitochondria, and Na(+)/Ca(2+) exchanger (NCX) on the differential tetanic Ca(2+) transient kinetics found in different fibre types. Tetanic Ca(2+) transients were classified as morphology type I (MT-I) or type II (MT-II) according to their shape. The first peak of the MT-I (n = 25) and MT-II (n = 23) tetanic Ca(2+) transients had an amplitude (∆F/F) of 0.41 ± 0.03 and 0.83 ± 0.05 and a rise time (ms) of 1.35 and 0.98, respectively. MT-I signals had a time constant of decay (τ1, ms) of 75.9 ± 4.2 while MT-II transients showed a double exponential decay with time constants of decay (τ1 and τ2, ms) of 18.3 ± 1.4 and 742.2 ± 130.3. Sarcoendoplasmic reticulum Ca(2+) ATPase inhibition demonstrated that the decay phase of the tetanic transients mostly rely on SERCA function. Adding Ca(2+) chelators in the AM form to MT-I fibres changed the morphology of the initial five peaks to a MT-II one, modifying the decay phase of the signal in a dose-dependent manner. Mitochondria and NCX function have a minor role in explaining differences in tetanic Ca(2+) transients among fibre types but still help in removing Ca(2+) from the cytosol in both MT-I and MT-II fibres. Cytoplasmic Ca(2+) buffering capacity and SERCA function explain most of the different kinetics found in tetanic Ca(2+) transients from different fibre types, but mitochondria and NCX have a measurable role in shaping tetanic Ca(2+) responses in both slow and fast-twitch muscle fibre types. We provided experimental evidence on the mechanisms that help understand the kinetics of tetanic Ca(2+) transients themselves and explain kinetic differences found among fibre types.

  10. Coexistence of potentiation and fatigue in skeletal muscle

    Directory of Open Access Journals (Sweden)

    D.E. Rassier

    2000-05-01

    Full Text Available Twitch potentiation and fatigue in skeletal muscle are two conditions in which force production is affected by the stimulation history. Twitch potentiation is the increase in the twitch active force observed after a tetanic contraction or during and following low-frequency stimulation. There is evidence that the mechanism responsible for potentiation is phosphorylation of the regulatory light chains of myosin, a Ca2+-dependent process. Fatigue is the force decrease observed after a period of repeated muscle stimulation. Fatigue has also been associated with a Ca2+-related mechanism: decreased peak Ca2+ concentration in the myoplasm is observed during fatigue. This decrease is probably due to an inhibition of Ca2+ release from the sarcoplasmic reticulum. Although potentiation and fatigue have opposing effects on force production in skeletal muscle, these two presumed mechanisms can coexist. When peak myoplasmic Ca2+ concentration is depressed, but myosin light chains are relatively phosphorylated, the force response can be attenuated, not different, or enhanced, relative to previous values. In circumstances where there is interaction between potentiation and fatigue, care must be taken in interpreting the contractile responses.

  11. Postactivation Potentiation of the Plantar Flexors Does Not Directly Translate to Jump Performance in Female Elite Young Soccer Players

    Directory of Open Access Journals (Sweden)

    Olaf Prieske

    2018-03-01

    Full Text Available High-intensity muscle actions have the potential to temporarily improve muscle contractile properties (i.e., postactivation potentiation, PAP thereby inducing acute performance enhancements. There is evidence that balance training can improve performance during strength exercises. Taking these findings together, the purpose of this study was to examine the acute effects of a combined balance and strength (B+S exercise vs. a strength only (S exercise on twitch contractile properties, maximum voluntary strength, and jump performance in young athletes. Female elite young soccer players (N = 12 aged 14–15 years conducted three experimental conditions in randomized order: S included 3 sets of 8–10 dynamic leg extensions at 80% of the 1-repetition maximum, B+S consisted of 3 sets of 40 s double-leg stances on a balance board prior to leg extensions (same as S, and a resting control period. Before and 7 min after exercise, participants were tested for their electrically-evoked isometric twitches (i.e., twitch peak torque, twitch rate of torque development and maximal voluntary contraction (MVC torque of the plantar flexor muscles. Additionally, countermovement (CMJ and drop jump (DJ performances (i.e., CMJ/DJ height, DJ ground contact time were assessed. Significant effects of condition on twitch contractile properties (p < 0.05, d = 1.1 and jump performance outputs (p < 0.05, 1.1 ≤ d ≤ 1.2 were found. Post-hoc tests revealed that S compared to control produced larger PAP for twitch peak torques by trend (p = 0.07, d = 1.8, 33 vs. 21% and significantly larger PAP for twitch rate of torque development (p < 0.05, d = 2.4, 55 vs. 43%. Following B+S compared to control, significant improvements in CMJ height (p < 0.01, d = 1.9, 3% and DJ contact time were found (p < 0.01, d = 2.0, 10%. This study revealed protocol-specific acute performance improvements. While S resulted in significant increases in twitch contractile properties, B+S produced

  12. AMPK alpha1 activation is required for stimulation of glucose uptake by twitch contraction, but not by H2O2, in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Schjerling, Peter; Viollet, Benoit

    2008-01-01

    into muscle by certain stimuli. In contrast, no clear function has yet been determined for alpha(1) AMPK in skeletal muscle, possibly due to alpha-AMPK isoform signaling redundancy. By applying low-intensity twitch-contraction and H(2)O(2) stimulation to activate alpha(1) AMPK, but not alpha(2) AMPK......, in wildtype and alpha-AMPK transgenic mouse muscles, this study aimed to define conditions where alpha(1) AMPK is required to increase muscle glucose uptake. METHODOLOGY/PRINCIPAL FINDINGS: Following stimulation with H(2)O(2) (3 mM, 20 min) or twitch-contraction (0.1 ms pulse, 2 Hz, 2 min), signaling and 2......-deoxyglucose uptake were measured in incubated soleus muscles from wildtype and muscle-specific kinase-dead AMPK (KD), alpha(1) AMPK knockout or alpha(2) AMPK knockout mice. H(2)O(2) increased the activity of both alpha(1) and alpha(2) AMPK in addition to Akt phosphorylation, and H(2)O(2)-stimulated glucose...

  13. Differentiation of the intracellular structure of slow- versus fast-twitch muscle fibers through evaluation of the dielectric properties of tissue

    Science.gov (United States)

    Sanchez, B.; Li, J.; Bragos, R.; Rutkove, S. B.

    2014-05-01

    Slow-twitch (type 1) skeletal muscle fibers have markedly greater mitochondrial content than fast-twitch (type 2) fibers. Accordingly, we sought to determine whether the dielectric properties of these two fiber types differed, consistent with their distinct intracellular morphologies. The longitudinal and transverse dielectric spectrum of the ex vivo rat soleus (a predominantly type 1 muscle) and the superficial layers of rat gastrocnemius (predominantly type 2) (n = 15) were measured in the 1 kHz-10 MHz frequency range and modeled to a resistivity Cole-Cole function. Major differences were especially apparent in the dielectric spectrum in the 1 to 10 MHz range. Specifically, the gastrocnemius demonstrated a well-defined, higher center frequency than the soleus muscle, whereas the soleus muscle showed a greater difference in the modeled zero and infinite resistivities than the gastrocnemius. These findings are consistent with the fact that soleus tissue has larger and more numerous mitochondria than gastrocnemius. Evaluation of tissue at high frequency could provide a novel approach for assessing intracellular structure in health and disease.

  14. Influence of fast and slow alkali myosin light chain isoforms on the kinetics of stretch-induced force transients of fast-twitch type IIA fibres of rat.

    Science.gov (United States)

    Andruchov, Oleg; Galler, Stefan

    2008-03-01

    This study contributes to understand the physiological role of slow myosin light chain isoforms in fast-twitch type IIA fibres of skeletal muscle. These isoforms are often attached to the myosin necks of rat type IIA fibres, whereby the slow alkali myosin light chain isoform MLC1s is much more frequent and abundant than the slow regulatory myosin light chain isoform MLC2s. In the present study, single-skinned rat type IIA fibres were maximally Ca(2+) activated and subjected to stepwise stretches for causing a perturbation of myosin head pulling cycles. From the time course of the resulting force transients, myosin head kinetics was deduced. Fibres containing MLC1s exhibited slower kinetics independently of the presence or absence of MLC2s. At the maximal MLC1s concentration of about 75%, the slowing was about 40%. The slowing effect of MLC1s is possibly due to differences in the myosin heavy chain binding sites of the fast and slow alkali MLC isoforms, which changes the rigidity of the myosin neck. Compared with the impact of myosin heavy chain isoforms in various fast-twitch fibre types, the influence of MLC1s on myosin head kinetics of type IIA fibres is much smaller. In conclusion, the physiological role of fast and slow MLC isoforms in type IIA fibres is a fine-tuning of the myosin head kinetics.

  15. Differentiation of the intracellular structure of slow- versus fast-twitch muscle fibers through evaluation of the dielectric properties of tissue

    International Nuclear Information System (INIS)

    Sanchez, B; Li, J; Rutkove, S B; Bragos, R

    2014-01-01

    Slow-twitch (type 1) skeletal muscle fibers have markedly greater mitochondrial content than fast-twitch (type 2) fibers. Accordingly, we sought to determine whether the dielectric properties of these two fiber types differed, consistent with their distinct intracellular morphologies. The longitudinal and transverse dielectric spectrum of the ex vivo rat soleus (a predominantly type 1 muscle) and the superficial layers of rat gastrocnemius (predominantly type 2) (n = 15) were measured in the 1 kHz–10 MHz frequency range and modeled to a resistivity Cole–Cole function. Major differences were especially apparent in the dielectric spectrum in the 1 to 10 MHz range. Specifically, the gastrocnemius demonstrated a well-defined, higher center frequency than the soleus muscle, whereas the soleus muscle showed a greater difference in the modeled zero and infinite resistivities than the gastrocnemius. These findings are consistent with the fact that soleus tissue has larger and more numerous mitochondria than gastrocnemius. Evaluation of tissue at high frequency could provide a novel approach for assessing intracellular structure in health and disease. (paper)

  16. The age related slow and fast contributions to the overall changes in tibialis anterior contractile features disclosed by maximal single twitch scan.

    Science.gov (United States)

    Orizio, Claudio; Cogliati, Marta; Bissolotti, Luciano; Diemont, Bertrand; Gobbo, Massimiliano; Celichowski, Jan

    2016-01-01

    This work aimed to verify if maximal electrically evoked single twitch (STmax) scan discloses the relative functional weight of fast and slow small bundles of fibres (SBF) in determining the contractile features of tibialis anterior (TA) with ageing. SBFs were recruited by TA main motor point stimulation through 60 increasing levels of stimulation (LS): 20 stimuli at 2Hz for each LS. The lowest and highest LS provided the least ST and STmax, respectively. The scanned STmax was decomposed into individual SBF STs. They were identified when twitches from adjacent LS were significantly different and then subtracted from each other. Nine young (Y) and eleven old (O) subjects were investigated. Contraction time (CT) and STarea/STpeak (A/PT) were calculated per each SBF ST. 143 and 155 SBF STs were obtained in Y and O, respectively. Y: CT and A/PT range: 45-105ms and 67-183mNs/mN, respectively. Literature data set TA fast fibres at 34% so, from the arrays of CT and A/PT, 65ms and 100mNs/mN were identified as the upper limit for SBF fast ST classification. O: no SBF ST could be classified as fast. STmax scan reveals age-related changes in the relative contribution of fast and slow SBFs to the overall muscle mechanics. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. An in vivo model for studying the dynamics of intracellular free calcium changes in slow- and fast-twitch muscle fibres.

    Science.gov (United States)

    Bátkai, S; Rácz, I B; Ivanics, T; Tóth, A; Hamar, J; Slaaf, D W; Reneman, R S; Ligeti, L

    1999-10-01

    The understanding of the regulation of the free cytosolic [Ca2+] ([Ca2+]i) in skeletal muscle is hampered by the lack of techniques for quantifying free [Ca2+]i in muscle fibres in situ. We describe a model for studying the dynamics of free [Ca2+]i in the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus (SOL) muscles of the rat in vivo using caffeine superfusion to induce changes in free [Ca2+]i. We assumed that differences in sensitivity between the two muscle types for this substance reflect differences in intracellular Ca2+ handling in the fibres of which these muscles consist. The Indo-1 ratiometric method, using intravital microscopy with incident light, was adapted to measure free [Ca2+]i in vivo. Fluorescence images were collected by means of a digital camera. Caffeine superfusion at 37 degrees C for 2 min, at concentrations of 1, 2, 5, 10 or 20 mmol/l, induced a concentration-dependent increase in free [Ca2+]i and revealed differences in caffeine sensitivity between the muscle types, with the SOL being more sensitive. In a separate set of experiments the contracture threshold, as assessed by topical application of caffeine, was determined in both muscle types. EDL had a higher threshold for developing contracture than SOL. These finding are in agreement with previous in vitro studies. We may conclude that the dynamics of free [Ca2+]i can be assessed reliably in intact mammalian muscle in vivo.

  18. Differential expression of FGF receptors and of myogenic regulatory factors in primary cultures of satellite cells originating from fast (EDL) and slow (Soleus) twitch rat muscles.

    Science.gov (United States)

    Martelly, I; Soulet, L; Bonnavaud, S; Cebrian, J; Gautron, J; Barritault, D

    2000-11-01

    In the rat, the fast and slow twitch muscles respectively Extensor digitorum longus (EDL) and Soleus present differential characteristics during regeneration. This suggests that their satellite cells responsible for muscle growth and repair represent distinct cellular populations. We have previously shown that satellite cells dissociated from Soleus and grown in vitro proliferate more readily than those isolated from EDL muscle. Fibroblast growth factors (FGFs) are known as regulators of myoblast proliferation and several studies have revealed a relationship between the response of myoblasts to FGF and the expression of myogenic regulatory factors (MRF) of the MyoD family by myoblasts. Therefore, we presently examined the possibility that the satellite cells isolated from EDL and Soleus muscles differ in the expression of FGF receptors (FGF-R) and of MRF expression. FGF-R1 and -R4 were strongly expressed in proliferating cultures whereas FGF-R2 and R3 were not detected in these cultures. In differentiating cultures, only -R1 was present in EDL satellite cells while FGF-R4 was also still expressed in Soleus cells. Interestingly, the unconventional receptor for FGF called cystein rich FGF receptor (CFR), of yet unknown function, was mainly detected in EDL satellite cell cultures. Soleus and EDL satellite cell cultures also differed in the expression MRFs. These results are consistent with the notion that satellite cells from fast and slow twitch muscles belong to different types of myogenic cells and suggest that satellite cells might play distinct roles in the formation and diversification of fast and slow fibres.

  19. Postactivation Potentiation of the Plantar Flexors Does Not Directly Translate to Jump Performance in Female Elite Young Soccer Players.

    Science.gov (United States)

    Prieske, Olaf; Maffiuletti, Nicola A; Granacher, Urs

    2018-01-01

    High-intensity muscle actions have the potential to temporarily improve muscle contractile properties (i.e., postactivation potentiation, PAP) thereby inducing acute performance enhancements. There is evidence that balance training can improve performance during strength exercises. Taking these findings together, the purpose of this study was to examine the acute effects of a combined balance and strength (B+S) exercise vs. a strength only (S) exercise on twitch contractile properties, maximum voluntary strength, and jump performance in young athletes. Female elite young soccer players ( N = 12) aged 14-15 years conducted three experimental conditions in randomized order: S included 3 sets of 8-10 dynamic leg extensions at 80% of the 1-repetition maximum, B+S consisted of 3 sets of 40 s double-leg stances on a balance board prior to leg extensions (same as S), and a resting control period. Before and 7 min after exercise, participants were tested for their electrically-evoked isometric twitches (i.e., twitch peak torque, twitch rate of torque development) and maximal voluntary contraction (MVC) torque of the plantar flexor muscles. Additionally, countermovement (CMJ) and drop jump (DJ) performances (i.e., CMJ/DJ height, DJ ground contact time) were assessed. Significant effects of condition on twitch contractile properties ( p jump performance outputs ( p jump performance. It is concluded that PAP effects in the plantar flexors may not directly translate to improved jump performance in female elite young soccer players. Therefore, the observed gains in jump performance following B+S are most likely related to neuromuscular changes (e.g., intramuscular coordination) rather than improved contractile properties.

  20. Changing oxidoreduction potential to improve water-soluble yellow pigment production with Monascus ruber CGMCC 10910.

    Science.gov (United States)

    Huang, Tao; Tan, Hailing; Lu, Fangju; Chen, Gong; Wu, Zhenqiang

    2017-11-21

    Monascus pigments are widely used in the food and pharmaceutical industries due to their safety to human health. Our previous study found that glucose concentration induced extracellular oxidoreduction potential (ORP) changes could influence extracellular water-soluble yellow pigment production by Monascus ruber CGMCC 10910 in submerged fermentation. In this study, H 2 O 2 and dithiothreitol (DTT) were used to change the oxidoreduction potential for investigating the effects of oxidative or reductive substances on Monascus yellow pigment production by Monascus ruber CGMCC 10910. The extracellular ORP could be controlled by H 2 O 2 and DTT. Both cell growth and extracellular water-soluble yellow pigment production were enhanced under H 2 O 2 -induced oxidative (HIO) conditions and were inhibited under dithiothreitol-induced reductive conditions. By optimizing the amount of H 2 O 2 added and the timing of the addition, the yield of extracellular water-soluble yellow pigments significantly increased and reached a maximum of 209 AU, when 10 mM H 2 O 2 was added on the 3rd day of fermentation with M. ruber CGMCC 10910. Under HIO conditions, the ratio of NADH/NAD+ was much lower than that in the control group, and the expression levels of relative pigment biosynthesis genes were up-regulated; moreover, the activity of glucose-6-phosphate dehydrogenase (G6PDH) was increased while 6-phosphofructokinase (PFK) activity was inhibited. Oxidative conditions induced by H 2 O 2 increased water-soluble yellow pigment accumulation via up-regulation of the expression levels of relative genes and by increasing the precursors of pigment biosynthesis through redirection of metabolic flux. In contrast, reductive conditions induced by dithiothreitol inhibited yellow pigment accumulation. This experiment provides a potential strategy for improving the production of Monascus yellow pigments.

  1. Juxtaposition of the changes in intracellular calcium and force during staircase potentiation at 30 and 37?C

    OpenAIRE

    Smith, Ian C.; Vandenboom, Rene; Tupling, A. Russell

    2014-01-01

    Ca2+ entry during the action potential stimulates muscle contraction. During repetitive low frequency stimulation, skeletal muscle undergoes staircase potentiation (SP), a progressive increase in the peak twitch force induced by each successive stimulus. Multiple mechanisms, including myosin regulatory light chain phosphorylation, likely contribute to SP, a temperature-dependent process. Here, we used the Ca2+-sensitive fluorescence indicators acetoxymethyl (AM)-furaptra and AM-fura-2 to exam...

  2. Myosin Binding Protein-C Slow Phosphorylation is Altered in Duchenne Dystrophy and Arthrogryposis Myopathy in Fast-Twitch Skeletal Muscles.

    Science.gov (United States)

    Ackermann, Maegen A; Ward, Christopher W; Gurnett, Christina; Kontrogianni-Konstantopoulos, Aikaterini

    2015-08-19

    Myosin Binding Protein-C slow (sMyBP-C), encoded by MYBPC1, comprises a family of regulatory proteins of skeletal muscles that are phosphorylated by PKA and PKC. MYBPC1 missense mutations are linked to the development of Distal Arthrogryposis-1 (DA-1). Although structure-function details for this myopathy are evolving, function is undoubtedly driven by sequence variations and post-translational modifications in sMyBP-C. Herein, we examined the phosphorylation profile of sMyBP-C in mouse and human fast-twitch skeletal muscles. We used Flexor Digitorum Brevis (FDB) isolated from young (~2-months old) and old (~14-months old) wild type and mdx mice, and human Abductor Hallucis (AH) and gastrocnemious muscles carrying the DA-1 mutations. Our results indicate both constitutive and differential phosphorylation of sMyBP-C in aged and diseased muscles. We report a 7-35% reduction in the phosphorylation levels of select sites in old wild type and young or old mdx FDB mouse muscles, compared to young wild type tissue. Similarly, we observe a 30-70% decrease in the phosphorylation levels of all PKA and PKC phospho-sites in the DA-1 AH, but not gastrocnemius, muscle. Overall, our studies show that the phosphorylation pattern of sMyBP-C is differentially regulated in response to age and disease, suggesting that phosphorylation plays important roles in these processes.

  3. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Gunnarsson, Thomas Gunnar Petursson; Thomassen, Martin

    2015-01-01

    perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50...... DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ...... of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics....

  4. Immunohistochemical evidence for expression of fast-twitch type sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA1) in German shepherd dogs with dilated cardiomyopathy myocardium.

    Science.gov (United States)

    Summerfield, Nuala; Peters, Mary E; Hercock, Carol A; Mobasheri, Ali; Young, Iain S

    2010-04-01

    Dilated cardiomyopathy (DCM) is one of the most common acquired canine heart diseases. It is particularly common in large and giant breed dogs. Although a great deal is known about the clinical progression and manifestations of the disease, the underlying cellular and molecular mechanisms remain poorly understood. One widely held belief is that calcium-handling abnormalities are critically involved in the disease process. This study investigates the changes in expression of the sarco(endo)plasmic reticulum calcium ATPase (SERCA) isoforms in DCM myocardium from German shepherd dogs. Affected tissue samples were obtained from German shepherd dogs with DCM, euthanized for intractable congestive heart failure while normal myocardial tissue samples were obtained from German shepherd dogs, euthanized for non-cardiovascular reasons. Tissue microarrays containing normal and DCM myocardium samples were prepared, immunostained with SERCA1 and SERCA2 antibodies and analyzed. We were able to demonstrate, for the first time, that while there is little change in the expression of the cardiac isoform (SERCA2), there is clear expression of the fast-twitch skeletal muscle isoform SERCA1 in the myocardium of dogs diagnosed with DCM. We propose that SERCA1 expression is evidence of a natural adaptive response to the impaired Ca2+ handling thought to occur in German shepherd dogs with DCM and heart failure. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Myosin phosphorylation improves contractile economy of mouse fast skeletal muscle during staircase potentiation.

    Science.gov (United States)

    Bunda, Jordan; Gittings, William; Vandenboom, Rene

    2018-01-30

    Phosphorylation of the myosin regulatory light chain (RLC) by skeletal myosin light chain kinase (skMLCK) potentiates rodent fast twitch muscle but is an ATP-requiring process. Our objective was to investigate the effect of skMLCK-catalyzed RLC phosphorylation on the energetic cost of contraction and the contractile economy (ratio of mechanical output to metabolic input) of mouse fast twitch muscle in vitro (25°C). To this end, extensor digitorum longus (EDL) muscles from wild-type (WT) and from skMLCK-devoid (skMLCK -/- ) mice were subjected to repetitive low-frequency stimulation (10 Hz for 15 s) to produce staircase potentiation of isometric twitch force, after which muscles were quick frozen for determination of high-energy phosphate consumption (HEPC). During stimulation, WT muscles displayed significant potentiation of isometric twitch force while skMLCK -/- muscles did not (i.e. 23% versus 5% change, respectively). Consistent with this, RLC phosphorylation was increased ∼3.5-fold from the unstimulated control value in WT but not in skMLCK -/- muscles. Despite these differences, the HEPC of WT muscles was not greater than that of skMLCK -/- muscles. As a result of the increased contractile output relative to HEPC, the calculated contractile economy of WT muscles was greater than that of skMLCK -/- muscles. Thus, our results suggest that skMLCK-catalyzed phosphorylation of the myosin RLC increases the contractile economy of WT mouse EDL muscle compared with skMLCK -/- muscles without RLC phosphorylation. © 2018. Published by The Company of Biologists Ltd.

  6. Validation of jump squats as a practical measure of post-activation potentiation.

    Science.gov (United States)

    Nibali, Maria L; Chapman, Dale W; Robergs, Robert A; Drinkwater, Eric J

    2013-03-01

    To determine if post-activation potentiation (PAP) can augment sports performance, it is pertinent that researchers be confident that any enhancement in performance is attributable to the PAP phenomenon. However, obtaining mechanistic measures of PAP in the daily training environment of highly trained athletes is impractical. We sought to validate jump squats as a practical measure with ecological validity to sports performance against a mechanistic measure of PAP. We assessed the evoked muscle twitch properties of the knee extensors and jump squat kinetics of 8 physically trained males in response to a 5-repetition-maximum back squat conditioning stimulus (CS). Evoked muscle twitch, followed by 3 jump squats, was assessed before and at 4, 8, and 12 min post CS. Time intervals were assessed on separate occasions using a Latin square design. Linear regression was used to determine the relationship between post-pre changes in kinetic variables and muscle twitch peak force (Ft) and twitch rate of force development (RFDt). Large correlations were observed for both concentric relative and absolute mean power and Ft (r = 0.50 ± 0.30) and RFDt (r = 0.56 ± 0.27 and r = 0.58 ± 0.26). Concentric rate of force development (RFD) showed moderate correlations with Ft (r = 0.45 ± 0.33) and RFDt (r = 0.49 ± 0.32). Small-to-moderate correlations were observed for a number of kinetic variables (r = -0.42-0.43 ± 0.32-0.38). Jump squat concentric mean power and RFD are valid ecological measures of muscle potentiation, capable of detecting changes in athletic performance in response to the PAP phenomenon.

  7. Role of calpain in eccentric contraction-induced proteolysis of Ca2+-regulatory proteins and force depression in rat fast-twitch skeletal muscle.

    Science.gov (United States)

    Kanzaki, Keita; Watanabe, Daiki; Kuratani, Mai; Yamada, Takashi; Matsunaga, Satoshi; Wada, Masanobu

    2017-02-01

    The aim of this study was to examine the in vivo effects of eccentric contraction (ECC) on calpain-dependent proteolysis of Ca 2+ -regulatory proteins and force production in fast-twitch skeletal muscles. Rat extensor digitorum longus muscles were exposed to 200 repeated ECC in situ and excised immediately [recovery 0 (REC0)] or 3 days [recovery 3 (REC3)] after cessation of ECC. Calpain inhibitor (CI)-treated rats were intraperitoneally injected with MDL-28170 before ECC and during REC3. Tetanic force was markedly reduced at REC0 and remained reduced at REC3. CI treatment ameliorated the ECC-induced force decline but only at REC3. No evidence was found for proteolysis of dihydropyridine receptor (DHPR), junctophilin (JP)1, JP2, ryanodine receptor (RyR), sarcoplasmic reticulum Ca 2+ -ATPase (SERCA)1a, or junctional face protein-45 at REC0. At REC3, ECC resulted in decreases in DHPR, JP1, JP2, RyR, and SERCA1a. CI treatment prevented the decreases in DHPR, JP1, and JP2, whereas it had little effect on RyR and SERCA1a. These findings suggest that DHPR, JP1, and JP2, but not RyR and SERCA1a, undergo calpain-dependent proteolysis in in vivo muscles subjected to ECC and that impaired function of DHPR and/or JP might cause prolonged force deficits with ECC. NEW & NOTEWORTHY Calpain-dependent proteolysis is one of the contributing factors to muscle damage that occurs with eccentric contraction (ECC). It is unclear, however, whether calpains account for proteolysis of Ca 2+ -regulatory proteins in in vivo muscles subjected to ECC. Here, we provide evidence that dihydropyridine receptor and junctophilin, but not ryanodine receptor and sarcoplasmic reticulum Ca 2+ -ATPase, undergo calpain-dependent proteolysis. Copyright © 2017 the American Physiological Society.

  8. A low redox potential affects monoclonal antibody assembly and glycosylation in cell culture.

    Science.gov (United States)

    Dionne, Benjamin; Mishra, Neha; Butler, Michael

    2017-03-20

    Glycosylation and intracellular assembly of monoclonal antibodies (MAbs) is important for glycan profile consistency. To better understand how these factors may be influenced by a lower redox potential, an IgG1-producing NS0 cell line was grown in the presence of varying concentrations of dithiothreitol (DTT). Cultures were monitored for growth and culture redox potential (CRP) with glycan heterogeneity determined using a HILIC-HPLC method. Macroheterogeneity was unchanged in all conditions whereas the Galactosylation Index (GI) decreased by as much as 50% in cultures with lower CRP or higher dithiothreitol levels. This shift in GI is reflected in more agalactosylated and asialylated species being produced. The MAb assembly pathway was determined using radioactive isotope 35 S incorporated into nascent IgG1 molecules. The assembly pathway for this IgG1 was shown to progress via HC→HC 2 →HC 2 LC→HC 2 LC 2 in all conditions tested and autoradiographs highlighted that the ratio of heavy chain dimer to heavy chain monomer increased over time with increasing DTT concentrations. This increase and correspondingly lower GI values may be due to disruption of the disulfide bonds at higher levels of assembly. A change in the assembly pathway may alter the final IgG glycan pattern and lead to control mechanisms that influence glycan profiles of MAbs. Copyright © 2017. Published by Elsevier B.V.

  9. Calsequestrin content and SERCA determine normal and maximal Ca2+ storage levels in sarcoplasmic reticulum of fast- and slow-twitch fibres of rat.

    Science.gov (United States)

    Murphy, Robyn M; Larkins, Noni T; Mollica, Janelle P; Beard, Nicole A; Lamb, Graham D

    2009-01-15

    Whilst calsequestrin (CSQ) is widely recognized as the primary Ca2+ buffer in the sarcoplasmic reticulum (SR) in skeletal muscle fibres, its total buffering capacity and importance have come into question. This study quantified the absolute amount of CSQ isoform 1 (CSQ1, the primary isoform) present in rat extensor digitorum longus (EDL) and soleus fibres, and related this to their endogenous and maximal SR Ca2+ content. Using Western blotting, the entire constituents of minute samples of muscle homogenates or segments of individual muscle fibres were compared with known amounts of purified CSQ1. The fidelity of the analysis was proven by examining the relative signal intensity when mixing muscle samples and purified CSQ1. The CSQ1 contents of EDL fibres, almost exclusively type II fibres, and soleus type I fibres [SOL (I)] were, respectively, 36 +/- 2 and 10 +/- 1 micromol (l fibre volume)(-1), quantitatively accounting for the maximal SR Ca2+ content of each. Soleus type II [SOL (II)] fibres (approximately 20% of soleus fibres) had an intermediate amount of CSQ1. Every SOL (I) fibre examined also contained some CSQ isoform 2 (CSQ2), which was absent in every EDL and other type II fibre except for trace amounts in one case. Every EDL and other type II fibre had a high density of SERCA1, the fast-twitch muscle sarco(endo)plasmic reticulum Ca2+-ATPase isoform, whereas there was virtually no SERCA1 in any SOL (I) fibre. Maximal SR Ca2+ content measured in skinned fibres increased with CSQ1 content, and the ratio of endogenous to maximal Ca2+ content was inversely correlated with CSQ1 content. The relative SR Ca2+ content that could be maintained in resting cytoplasmic conditions was found to be much lower in EDL fibres than in SOL (I) fibres (approximately 20 versus >60%). Leakage of Ca2+ from the SR in EDL fibres could be substantially reduced with a SR Ca2+ pump blocker and increased by adding creatine to buffer cytoplasmic [ADP] at a higher level, both results

  10. Slow-tonic muscle fibers and their potential innervation in the turtle, Pseudemys (Trachemys) scripta elegans.

    Science.gov (United States)

    Callister, Robert J; Pierce, Patricia A; McDonagh, Jennifer C; Stuart, Douglas G

    2005-04-01

    fiber type, with the distribution of slow-tonic fibers paralleling that of the SO fibers. In the five test muscles, fiber cross-sectional area was usually ranked Fg > FOG > SO, and slow-twitch always > slow-tonic. In terms of weighted cross-sectional area, which provides a coarse-grain measure of each fiber type's potential contribution to whole muscle force, all five muscles exhibited a higher Fg and lower SO contribution to cross-sectional area than suggested by their corresponding fiber-type prevalence. This was also the case for the slow-twitch vs. slow-tonic fibers. We conclude that slow-tonic fibers are widespread in turtle muscle. The weighted cross-sectional area evidence suggested, however, that their contribution to force generation is minor except in highly oxidative muscles, with a special functional role, like TeC4. There is discussion of: 1) the relationship between the present results and previous work on homologous neck and hindlimb muscles in other nonmammalian species, and 2) the potential motoneuronal innervation of slow-tonic fibers in turtle hindlimb muscles. Copyright 2005 Wiley-Liss, Inc.

  11. S-glutathionylation of troponin I (fast) increases contractile apparatus Ca2+ sensitivity in fast-twitch muscle fibres of rats and humans.

    Science.gov (United States)

    Mollica, J P; Dutka, T L; Merry, T L; Lamboley, C R; McConell, G K; McKenna, M J; Murphy, R M; Lamb, G D

    2012-03-15

    Oxidation can decrease or increase the Ca2+ sensitivity of the contractile apparatus in rodent fast-twitch (type II) skeletal muscle fibres, but the reactions and molecular targets involved are unknown. This study examined whether increased Ca2+ sensitivity is due to S-glutathionylation of particular cysteine residues. Skinned muscle fibres were directly activated in heavily buffered Ca2+ solutions to assess contractile apparatus Ca2+ sensitivity. Rat type II fibres were subjected to S-glutathionylation by successive treatments with 2,2′-dithiodipyridine (DTDP) and glutathione (GSH), and displayed a maximal increase in pCa50 (−log10 [Ca2+] at half-maximal force) of ∼0.24 pCa units, with little or no effect on maximum force or Hill coefficient. Partial similar effect was produced by exposure to oxidized gluthathione (GSSG, 10 mM) for 10 min at pH 7.1, and near-maximal effect by GSSG treatment at pH 8.5. None of these treatments significantly altered Ca2+ sensitivity in rat type I fibres. Western blotting showed that both the DTDP–GSH and GSSG–pH 8.5 treatments caused marked S-glutathionylation of the fast troponin I isoform (TnI(f)) present in type II fibres, but not of troponin C (TnC) or myosin light chain 2. Both the increased Ca2+ sensitivity and glutathionylation of TnI(f) were blocked by N-ethylmaleimide (NEM). S-nitrosoglutathione (GSNO) also increased Ca2+ sensitivity, but only in conditions where it caused S-glutathionylation of TnI(f). In human type II fibres from vastus lateralis muscle, DTDP–GSH treatment also caused similar increased Ca2+ sensitivity and S-glutathionylation of TnI(f). When the slow isoform of TnI in type I fibres of rat was partially substituted (∼30%) with TnI(f), DTDP–GSH treatment caused a significant increase in Ca2+ sensitivity (∼0.08 pCa units). TnIf in type II fibres from toad and chicken muscle lack Cys133 present in mammalian TnIf, and such fibres showed no change in Ca2+ sensitivity with DTDP–GSH nor any S

  12. Caffeine and length dependence of staircase potentiation in skeletal muscle.

    Science.gov (United States)

    Rassier, D E; Tubman, L A; MacIntosh, B R

    1998-01-01

    Skeletal muscle sensitivity to Ca2+ is greater at long lengths, and this results in an optimal length for twitch contractions that is longer than optimal length for tetanic contractions. Caffeine abolishes this length dependence of Ca2+ sensitivity. Muscle length (ML) also affects the degree of staircase potentiation. Since staircase potentiation is apparently caused by an increased Ca2+ sensitivity of the myofilaments, we tested the hypothesis that caffeine depresses the length dependence of staircase potentiation. In situ isometric twitch contractions of rat gastrocnemius muscle before and after 10 s of 10-Hz stimulation were analyzed at seven different lengths to evaluate the length dependence of staircase potentiation. In the absence of caffeine, length dependence of Ca2+ sensitivity was observed, and the degree of potentiation after 10-Hz stimulation showed a linear decrease with increased length (DT = 1.47 - 0.05 ML, r2 = 0.95, where DT is developed tension). Length dependence of Ca2+ sensitivity was decreased by caffeine when caffeine was administered in amounts estimated to result in 0.5 and 0.75 mM concentrations. Furthermore, the negative slope of the relationship between staircase potentiation and muscle length was diminished at the lower caffeine dose, and the slope was not different from zero after the higher dose (DT = 1.53 - 0.009 ML, r2 = 0.43). Our study shows that length dependence of Ca2+ sensitivity in intact skeletal muscle is diminished by caffeine. Caffeine also suppressed the length dependence of staircase potentiation, suggesting that the mechanism of this length dependence may be closely related to the mechanism for length dependence of Ca2+ sensitivity.

  13. Oxidative shift in tissue redox potential increases beat-to-beat variability of action potential duration.

    Science.gov (United States)

    Kistamás, Kornél; Hegyi, Bence; Váczi, Krisztina; Horváth, Balázs; Bányász, Tamás; Magyar, János; Szentandrássy, Norbert; Nánási, Péter P

    2015-07-01

    Profound changes in tissue redox potential occur in the heart under conditions of oxidative stress frequently associated with cardiac arrhythmias. Since beat-to-beat variability (short term variability, SV) of action potential duration (APD) is a good indicator of arrhythmia incidence, the aim of this work was to study the influence of redox changes on SV in isolated canine ventricular cardiomyocytes using a conventional microelectrode technique. The redox potential was shifted toward a reduced state using a reductive cocktail (containing dithiothreitol, glutathione, and ascorbic acid) while oxidative changes were initiated by superfusion with H2O2. Redox effects were evaluated as changes in "relative SV" determined by comparing SV changes with the concomitant APD changes. Exposure of myocytes to the reductive cocktail decreased SV significantly without any detectable effect on APD. Application of H2O2 increased both SV and APD, but the enhancement of SV was the greater, so relative SV increased. Longer exposure to H2O2 resulted in the development of early afterdepolarizations accompanied by tremendously increased SV. Pretreatment with the reductive cocktail prevented both elevation in relative SV and the development of afterdepolarizations. The results suggest that the increased beat-to-beat variability during an oxidative stress contributes to the generation of cardiac arrhythmias.

  14. Potentiation by substance P of contractions of the isolated vas deferens of the mouse elicited by electric field stimulation and by drugs

    International Nuclear Information System (INIS)

    Blackwell, M.; James, T.A.; Starr, M.S.

    1978-01-01

    Isolated vasa deferentia from the mouse were opened longitudinally and suspended in Krebs solution at 37 0 C in an organ bath. Contractions of the muscle were elicited by electric field stimulation, noradrenaline (10 -6 M) and acetylcholine (10 -6 M). Continued transmural stimulation evoked a biphasic response comprising a rapid twitch followed by about 10 s later by a smaller, sustained rise in muscle tone. The amplitudes of nerve-mediated and drug-induced responses were considerably potentiated by substances P (SP) in the dose range 10 -12 to 10 -7 M. Higher concentrations of SP were directly spasmogenic. The sensitizing property of SP was dose-dependent and was usually well maintained, but always disappeared quickly on washing the preparation. In some experiments SP facilitated the twitch, but not the subsequent phase of the electrically-induced contraction or the response to externally applied noradrenaline. Phentolamine (10 -6 M) failed to block this effect of SP, but itself potentiated the nerve-mediated twitch, and completely abolished the sustained secondary contraction. Desmethylimipramine (10 -6 M) enhanced the delayed contraction but not the immediate contraction. The uptake of tritiated noradrenaline (3 x 10 -7 M) by vasa was inhibited by desmethylimipramine (10 -6 M) and increased by nialamide (3 x 10 -5 M), but was not modified by SP (10 -6 M). Nerve-mediated release of accumulated radioactivity was accelerated by phentolamine, but not by SP or desmethylimipramine. These findings suggest that SP sensitizes the muscle cells to depolarizing stimuli but that it has no facilitatory effect on sympathetic neural elements. (author)

  15. The effects of inorganic phosphate and arsenate on both passive muscle visco-elasticity and maximum Ca2+ activated tension in chemically skinned rat fast and slow twitch muscle fibres.

    Science.gov (United States)

    Mutungi, Gabriel

    2003-01-01

    The effects of adding either 25 mM inorganic phosphate (Pi) or its structural analogue arsenate (ASi) on both the maximum Ca2+ activated tension (Po) and passive muscle visco-elasticity (P2 tension) were investigated at 10 degrees C, using segments of single, chemically skinned rat muscle fibres. Whilst the results confirmed some previous findings on the effects of Pi on Po, they also showed that the addition of 25 mM ASi led to a large (approximately 50%) but completely reversible depression of Po in both the fast and slow twitch rat muscle fibres. Moreover, the depression of Po by ASi was greater at low than at high pH values. Examined in the presence of Dextran T-500, the passive tension and sarcomere length responses to a ramp stretch were found to be qualitatively and quantitatively similar to those previously reported in intact rat muscle fibres. Thus, the tension response to a ramp stretch, in the presence and absence of either 25 mM Pi or ASi, consisted of a viscous (P1), a visco-elastic (P2) and an elastic (P3) tension. However, the addition of either 25 mM Pi or ASi led to approximately 15-18% increase in the amplitude of the visco-elastic (P2) tension but had little or no effect on the amplitudes of the other two tension components (viscous, P1 and elastic, P3 tensions). Furthermore, neither compound significantly altered the relaxation rate of the passive muscle visco-elasticity (P2 tension). These results show that Po (arising from cycling cross-bridges) and passive muscle visco-elasticity (P2 tension) are affected differently by both Pi and ASi and suggest that they may not share a common structural basis. The possibility that passive muscle visco-elasticity (P2 tension) arises from the gap-(titin) filament (as suggested previously by Mutungi and Ranatunga, 1996b J Physiol 496: 827-837) and that Pi and ASi increase its amplitude by interacting with the PEVK region of the filament are discussed.

  16. When climate twitches, evolution takes great leaps

    International Nuclear Information System (INIS)

    Kerr, R.A.

    1992-01-01

    Earth's climate system has ridden a slow roller coaster for the past 60 million years. It warmed gradually until about 53 million years ago, reaching a peak that brought crocodiles to northern Canada; then it entered a long, undulating downgrade toward the ice-age world of the past few million years. Because the same span of time brought major evolutionary changes, including the rise of modern mammals, paleontologists have long assumed that these slow temperature changes helped spur the processes of evolution. But recent findings have suggested that another, more potent mechanisms was also at work: Abrupt climate excursions, superimposed on these long-term trends, have now been linked to rapid periods of mammal evolution. The evidence for short, sharp evolutionary shocks comes from studies of a pair of mirror-image climate shifts at opposite ends of the Eocene epoch, 55 million and 33.5 million years ago. In both cases, researchers studying the record of climate preserved in sea-floor sediments have found that a gradual climate change-warming in the first case, cooling in the second - suddenly steepened into a short-lived pulse of extreme warming or cooling. The short time scale of these events and their clear coincidence with turning points in the evolution of mammals are providing the tightest links yet between global climate change and evolution on land

  17. The influence of D2O, perchlorate, and variation in temperature on the potential-dependent contractile function of frog skeletal muscle

    International Nuclear Information System (INIS)

    Foulks, J.G.; Morishita, L.

    1985-01-01

    D 2 O and perchlorate manifest opposing effects on the contractile function of skeletal muscle (amplitude of twitches and maximum K contractures, potential dependence of contraction and inactivation), and when combined the influence of one may effectively antagonize that of the other. The ratio of perchlorate concentrations required to produce effects of equal intensity, (e.g., twitch enhancement and restoration of maximum K contractures in media lacking divalent cations or containing a depressant concentration of a cationic amphipath) in H 2 O and D 2 O solutions was generally rather constant. These findings are compatible with the view that both agents can influence contractile function by virtue of their effects on solvent structure. In the absence of divalent cations, the effects of reduced temperature resemble those of D 2 O whereas the effects of increased temperature resemble those of the chaotropic anion. However, in other media, variation in temperature was found to result in additional nonsolvent effects so that low temperature could oppose rather than enhance the effects of D 2 O. These observations are discussed in terms of a model which postulates a role for solvent influences on the kinetics of two separate potential-dependent conformational transitions of membrane proteins which mediate the activation and inactivation of contraction in skeletal muscle

  18. Limitations in Using Chemical Oxidative Potential to Understand Oxidative Stress from Particulate Matter

    Science.gov (United States)

    Chan, A. W. H.; Wang, S.; Wang, X.; Kohl, L.; Chow, C. W.

    2017-12-01

    Particulate matter (PM) in the atmosphere is known to cause adverse cardiorespiratory health effects. It has been suggested that the ability of PM to generate oxidative stress leads to a proinflammatory response. In this work, we study the biological relevance of using a chemical oxidative potential (OP) assay to evaluate proinflammatory response in airway epithelial cells. Here we study the OPs of laboratory secondary organic aerosol (SOA) and metal mixtures, ambient PM from India, ash from the 2016 Alberta wildfires, and diesel exhaust particles. We use SOA derived from naphthalene and from monoterpenes as model systems for SOA. We measure OP using the dithiothreitol (DTT) assay, and cytosolic reactive oxygen species (ROS) production in BEAS-2B cell culture was measured using CellROX assay. We found that both SOA and copper show high OPs individually, but the OP of the combined SOA/copper mixture, which is more atmospherically relevant, was lower than either of the individual OPs. The reduced activity is attributed to chelation between metals and organic compounds using proton nuclear magnetic resonance. There is reasonable association between DTT activity and cellular ROS production within each particle type, but weak association across different particle types, suggesting that particle composition plays an important role in distinguishing between antioxidant consumption and ROS production. Our results highlight that while oxidative potential is a useful metric of PM's ability to generate oxidative stress, the chemical composition and cellular environment should be considered in understanding health impacts of PM.

  19. An in vitro model to test relative antioxidant potential: Ultraviolet-induced lipid peroxidation in liposomes

    International Nuclear Information System (INIS)

    Pelle, E.; Maes, D.; Padulo, G.A.; Kim, E.K.; Smith, W.P.

    1990-01-01

    Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, the following results were found among lipophilic antioxidants: BHA greater than catechin greater than BHT greater than alpha-tocopherol greater than chlorogenic acid. Among hydrophilic antioxidants, ascorbic acid and dithiothreitol were effective while glutathione was ineffective. In addition, ascorbic acid was observed to act synergistically with alpha-tocopherol, which is in agreement with other published reports on the interaction of these two antioxidants. Although peroxyl radical scavengers seem to be at a selective advantage in this liposomal/UV system, these results demonstrate the validity of this technique as an assay for measuring an antioxidant's potential to inhibit UV-induced peroxidation

  20. Length dependence of staircase potentiation: interactions with caffeine and dantrolene sodium.

    Science.gov (United States)

    Rassier, D E; MacIntosh, B R

    2000-04-01

    In skeletal muscle, there is a length dependence of staircase potentiation for which the mechanism is unclear. In this study we tested the hypothesis that abolition of this length dependence by caffeine is effected by a mechanism independent of enhanced Ca2+ release. To test this hypothesis we have used caffeine, which abolishes length dependence of potentiation, and dantrolene sodium, which inhibits Ca2+ release. In situ isometric twitch contractions of rat gastrocnemius muscle before and after 20 s of repetitive stimulation at 5 Hz were analyzed at optimal length (Lo), Lo - 10%, and Lo + 10%. Potentiation was observed to be length dependent, with an increase in developed tension (DT) of 78 +/- 12, 51 +/- 5, and 34 +/- 9% (mean +/- SEM), at Lo - 10%, Lo, and Lo + 10%, respectively. Caffeine diminished the length dependence of activation and suppressed the length dependence of staircase potentiation, giving increases in DT of 65+/-13, 53 +/- 11, and 45 +/- 12% for Lo - 10%, Lo, and Lo + 10%, respectively. Dantrolene administered after caffeine did not reverse this effect. Dantrolene alone depressed the potentiation response, but did not affect the length dependence of staircase potentiation, with increases in DT of 58 +/- 17, 26 +/- 8, and 18 +/- 7%, respectively. This study confirms that there is a length dependence of staircase potentiation in mammalian skeletal muscle which is suppressed by caffeine. Since dantrolene did not alter this suppression of the length dependence of potentiation by caffeine, it is apparently not directly modulated by Ca2+ availability in the myoplasm.

  1. Oxidative potential of secondary organic aerosols produced from photooxidation of different hydrocarbons using outdoor chamber under ambient sunlight

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Sabo-Attwood, Tara; Robinson, Sarah E.

    2016-04-01

    The oxidative potential of various secondary organic aerosols (SOA) was measured using dithiothreitol (DTT) assay to understand how organic aerosols react with cellular materials. SOA was produced via the photooxidation of four different hydrocarbons (toluene, 1,3,5-trimethylbenzene, isoprene and α-pinene) in the presence of NOx using a large outdoor photochemical smog chamber. The DTT consumption rate was normalized by the aerosol mass, which is expressed as DTTmass. Toluene SOA and isoprene SOA yielded higher DTTmass than 1,3,5-trimethylbenzene SOA or α-pinene SOA. In order to discover the correlation between the molecular structure and oxidative potential, the DTT responses of selected model compounds were also measured. Among them, conjugated aldehydes, quinones, and H2O2 showed considerable DTT response. To investigate the correlation between DTT response and cell responses in vitro, the expression of biological markers, i.e. IL-6, IL-8, and HMOX-1 were studied using small airway epithelial cells. Higher cellular expression of IL-8 was observed with toluene SOA exposure compared to 1,3,5-trimethylbenzene SOA exposure, which aligned with the results from DTT assay. Our study also suggests that within the urban atmosphere, the contribution of toluene SOA and isoprene SOA to the oxidative potential of ambient SOA will be more significant than that of α-pinene SOA.

  2. Changes in contractile properties and action potentials of motor units in the rat medial gastrocnemius muscle during maturation.

    Science.gov (United States)

    Dobrzynska, Z; Celichowski, J

    2016-02-01

    The early phase of development of muscles stops following the disappearance of embryonic and neonatal myosin and the elimination of polyneuronal innervation of muscle fibres with the formation of motor units (MUs), but later the muscle mass still considerably increases. It is unknown whether the three types are visible among newly formed MUs soon after the early postnatal period and whether their proportion is similar to that in adult muscle. Moreover, the processes responsible for MU-force regulation by changes in motoneuronal firing rate as well as properties of motor unit action potentials (MUAPs) during maturation are unknown. Three groups of Wistar rats were investigated - 1 month old, 2 months old and the adult, 9 months old. The basic contractile properties and action potentials of MUs in the medial gastrocnemius (MG) muscle were analysed. The three types of MUs were distinguishable in all age groups, but higher proportion of slow MUs was noticed in young rats (29%, 18% and 11% in 1, 2 and 9 months rats, respectively). The fatigue index for fast fatigable MUs in 1 month old rats was about 2 times higher than in 9 months old rats. The twitch time parameters of fast MUs were shortened during the maturation; for these units, the force-frequency curves in young rats were shifted towards lower frequencies, which suggested that fast motoneurons of young animals generate lower firing rates. Higher twitch-to-tetanus ratios noted for the three MU types in young rats suggested the smaller role of rate coding in force regulation processes, and the higher role of MU recruitment in young rats. No significant differences in MUAP parameters between two groups of young and adult animals were observed. Concluding, the maturation process evokes deeper changes in fast MUs than in slow ones.

  3. Simple protein structure-sensitive chronopotentiometric analysis with dithiothreitol-modified Hg electrodes

    Czech Academy of Sciences Publication Activity Database

    Ostatná, Veronika; Černocká, Hana; Paleček, Emil

    2012-01-01

    Roč. 87, SI (2012), s. 84-88 ISSN 1567-5394 R&D Projects: GA AV ČR(CZ) KJB100040901; GA ČR(CZ) GAP301/11/2055; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : protein electroanalysis * DTT-modified electrodes * electrocatalysis Subject RIV: BO - Biophysics Impact factor: 3.947, year: 2012

  4. Potential Theory

    CERN Document Server

    Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří

    1988-01-01

    Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in­ cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...

  5. Potential bags

    International Nuclear Information System (INIS)

    Ferreira, P.L.; Tomio, L.

    1992-01-01

    In this paper, relativistic confining potential models, endowed with bag constants associated to volume energy terms, are investigated. In contrast to the usual bag model, these potential bags are distinguished by having smeared bag surfaces. Based on the dynamical assumptions underlying the fuzzy bag model, these bag constants are derived from the corresponding energy-momentum tensor. Explicit expressions for the single-quark energies and for the nucleon bag constant are obtained by means of an improved analytical version of the saddle-point variational method for the Dirac equation with confining power-law potentials of the scalar plus vector (S + V) or pure scalar (S) type

  6. Groundwater Potential

    African Journals Online (AJOL)

    big timmy

    4Department of Geology, Ekiti State University, Ado-Ekiti, Nigeria. Corresponding ... integrated for the classification of the study area into different groundwater potential zones. .... table is mainly controlled by subsurface movement of water into ...

  7. Violent Potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Søgaard, Thomas Friis

    2015-01-01

    ” plays a critical role in relation to Bugkalot men’s construction of hegemonic masculinity and the sustaining of complex egalitarian relations. The Bugkalot have a notoriously violent history; until the late 1970s more than half of the adult men engaged in ritual killings. While most Bugkalot men has...... that can also be used in other contexts to understand how men construct hegemonic masculinity by strategically adopting the interspace of civility and violence.......This article explores the social significance of violence as potentiality and performance among former headhunters. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence as “performed violent potentiality...

  8. Potential theory

    CERN Document Server

    Helms, Lester L

    2014-01-01

    Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...

  9. Violent potentials

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Friis Søgaard, Thomas

    2016-01-01

    as ‘performed violent potentiality’ plays a critical role in relation to Bugkalot men’s construction of hegemonic masculinity and the sustaining of complex egalitarian relations. The Bugkalot have a notoriously violent history; until the late 1970s more than half of the adult men engaged in ritual killings...... provide general insights that can also be used in other contexts to understand how men construct hegemonic masculinity by strategically adopting the interspace of civility and violence.......This article explores the social significance of violence as potentiality and performance among former headhunters engaged in ritual killings. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence...

  10. Relationship between chemical composition and oxidative potential of secondary organic aerosol from polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Wang, Shunyao; Ye, Jianhuai; Soong, Ronald; Wu, Bing; Yu, Legeng; Simpson, André J.; Chan, Arthur W. H.

    2018-03-01

    Owing to the complex nature and dynamic behaviors of secondary organic aerosol (SOA), its ability to cause oxidative stress (known as oxidative potential, or OP) and adverse health outcomes remains poorly understood. In this work, we probed the linkages between the chemical composition of SOA and its OP, and investigated impacts from various SOA evolution pathways, including atmospheric oligomerization, heterogeneous oxidation, and mixing with metal. SOA formed from photooxidation of the two most common polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) were studied as model systems. OP was evaluated using the dithiothreitol (DTT) assay. The oligomer-rich fraction separated by liquid chromatography dominates DTT activity in both SOA systems (52 ± 10 % for naphthalene SOA (NSOA), and 56 ± 5 % for phenanthrene SOA (PSOA)). Heterogeneous ozonolysis of NSOA was found to enhance its OP, which is consistent with the trend observed in selected individual oxidation products. DTT activities from redox-active organic compounds and metals were found to be not additive. When mixing with highly redox-active metal (Cu), OP of the mixture decreased significantly for 1,2-naphthoquinone (42 ± 7 %), 2,3-dihydroxynaphthalene (35 ± 1 %), NSOA (50 ± 6 %), and PSOA (43 ± 4 %). Evidence from proton nuclear magnetic resonance (1H NMR) spectroscopy illustrates that such OP reduction upon mixing can be ascribed to metal-organic binding interactions. Our results highlight the role of aerosol chemical composition under atmospheric aging processes in determining the OP of SOA, which is needed for more accurate and explicit prediction of the toxicological impacts from particulate matter.

  11. Sources and oxidative potential of water-soluble humic-like substances (HULISWS in fine particulate matter (PM2.5 in Beijing

    Directory of Open Access Journals (Sweden)

    Y. Ma

    2018-04-01

    Full Text Available Water-soluble humic-like substances (HULISWS are a major redox-active component of ambient fine particulate matter (PM2.5; however, information on their sources and associated redox activity is limited. In this study, HULISWS mass concentration, various HULISWS species, and dithiothreitol (DTT activity of HULISWS were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the nonheating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhausts, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors ( >  59 % to both HULISWS and associated DTT activity throughout the year. During the nonheating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for  >  70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

  12. Sources and oxidative potential of water-soluble humic-like substances (HULISWS) in fine particulate matter (PM2.5) in Beijing

    Science.gov (United States)

    Ma, Yiqiu; Cheng, Yubo; Qiu, Xinghua; Cao, Gang; Fang, Yanhua; Wang, Junxia; Zhu, Tong; Yu, Jianzhen; Hu, Di

    2018-04-01

    Water-soluble humic-like substances (HULISWS) are a major redox-active component of ambient fine particulate matter (PM2.5); however, information on their sources and associated redox activity is limited. In this study, HULISWS mass concentration, various HULISWS species, and dithiothreitol (DTT) activity of HULISWS were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the nonheating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhausts, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors ( > 59 %) to both HULISWS and associated DTT activity throughout the year. During the nonheating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for > 70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

  13. Chemical characterization and oxidative potential of particles emitted from open burning of cereal straws and rice husk under flaming and smoldering conditions

    Science.gov (United States)

    Fushimi, Akihiro; Saitoh, Katsumi; Hayashi, Kentaro; Ono, Keisuke; Fujitani, Yuji; Villalobos, Ana M.; Shelton, Brandon R.; Takami, Akinori; Tanabe, Kiyoshi; Schauer, James J.

    2017-08-01

    Open burning of crop residue is a major source of atmospheric fine particle emissions. We burned crop residues (rice straws, barley straws, wheat straws, and rice husks produced in Japan) in an outdoor chamber and measured particle mass, composition (elemental carbon: EC, organic carbon: OC, ions, elements, and organic species), and oxidative potential in the exhausts. The fine particulate emission factors from the literature were within the range of our values for rice straws but were 1.4-1.9 and 0.34-0.44 times higher than our measured values for barley straw and wheat straw, respectively. For rice husks and wheat straws, which typically lead to combustion conditions that are relatively mild, the EC content of the particles was less than 5%. Levoglucosan seems more suitable as a biomass burning marker than K+, since levoglucosan/OC ratios were more stable than K+/particulate mass ratios among crop species. Stigmasterol and β-sitosterol could also be used as markers of biomass burning with levoglucosan or instead of levoglucosan. Correlation analysis between chemical composition and combustion condition suggests that hot or flaming combustions enhance EC, K+, Cl- and polycyclic aromatic hydrocarbons emissions, while low-temperature or smoldering combustions enhance levoglucosan and water-soluble organic carbon emissions. Oxidative potential, measured with macrophage-based reactive oxygen species (ROS) assay and dithiothreitol (DTT) assay, of open burning fine particles per particulate mass as well as fine particulate emission factors were the highest for wheat straws and second highest for rice husks and rice straws. Oxidative potential per particulate mass was in the lower range of vehicle exhaust and atmosphere. These results suggest that the contribution of open burning is relatively small to the oxidative potential of atmospheric particles. In addition, oxidative potential (both ROS and DTT activities) correlated well with water-insoluble organic species

  14. Effects of caffeine at different temperatures on contractile properties of slow-twitch and fast-twitch rat muscles

    Czech Academy of Sciences Publication Activity Database

    Wondmikun, Y.; Soukup, Tomáš; Asmussen, G.

    2006-01-01

    Roč. 55, č. 6 (2006), s. 641-652 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/05/0327 Grant - others:Schwerpunkt Muskelforschung(DE) As 74/1-2; MYORES(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : MyHC mRNA transcripts and protein isoforms * altered thyroid status * rat muscles Subject RIV: ED - Physiology Impact factor: 2.093, year: 2006

  15. Oxidative potential of particulate matter 2.5 as predictive indicator of cellular stress

    International Nuclear Information System (INIS)

    Crobeddu, Bélinda; Aragao-Santiago, Leticia; Bui, Linh-Chi; Boland, Sonja; Baeza Squiban, Armelle

    2017-01-01

    Particulate air pollution being recognized to be responsible for short and long term health effects, regulations for particulate matter with an aerodynamic diameter less than 2.5 (PM 2.5 ) are more and more restrictive. PM 2.5 regulation is based on mass without taking into account PM 2.5 composition that drives toxicity. Measurement of the oxidative potential (OP) of PM could be an additional PM indicator that would encompass the PM components involved in oxidative stress, the main mechanism of PM toxicity. We compared different methods to evaluate the intrinsic oxidative potential of PM 2.5 sampled in Paris and their ability to reflect the oxidative and inflammatory response in bronchial epithelial cells used as relevant target organ cells. The dithiothreitol depletion assay, the antioxidant (ascorbic acid and glutathione) depletion assay (OP AO ), the plasmid scission assay and the dichlorofluorescein (DCFH) oxidation assay used to characterize the OP of PM 2.5 (10–100 μg/mL) provided positive results of different magnitude with all the PM 2.5 samples used with significant correlation with different metals such as Cu and Zn as well as total polyaromatic hydrocarbons and the soluble organic fraction. The OP AO assay showed the best correlation with the production of intracellular reactive oxygen species by NCI-H292 cell line assessed by DCFH oxidation and with the expression of anti-oxidant genes (superoxide dismutase 2, heme-oxygenase-1) as well as the proinflammatory response (Interleukin 6) when exposed from 1 to 10 μg/cm 2 . The OP AO assay appears as the most prone to predict the biological effect driven by PM 2.5 and related to oxidative stress. - Highlights: • 5 Acellular assays were used to compare the intrinsic oxidative potential (OP) of PM. • The amount of ROS generation in bronchial cells is particle dependent. • Particles induce the expression of anti-oxidant and proinflammatory genes. • Biological effects correlates with OP assay

  16. The reducing agent Dithiothreitol (DTT) increases expression of c-myc and c- fos protooncogenes in human cells

    DEFF Research Database (Denmark)

    Skouv, J.; Sørensen, Ilona Kryspin; Frandsen, H.

    1995-01-01

    The objective of the present study was to assess the possible tumour promoting activity of the food mutagen 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), by studying its influence on the expression of three genes considered to be of relevance in the tumour promotion step...

  17. Oxidative Potential of ambient particulate matter in Athens, Greece.

    Science.gov (United States)

    Paraskevopoulou, Despina; Bougiatioti, Aikaterini; Fang, Ting; Liakakou, Eleni; Weber, Rodney; Nenes, Athanasios; Mihalopoulos, Nikolaos

    2017-04-01

    Exposure of populations to airborne particulate matter (PM) is a leading cause of premature death worldwide. Oxidative stress resulting from exposure of chemical species present in PM is a mechanism thought to cause adverse health effects. Apart from radicals present in aerosol, species that can catalytically deplete the antioxidant buffering capacity of cells, called Oxidative Potential (OP), are thought to be particularly toxic. The variability of OP over location, particle age, source and environmental conditions is virtually unknown for most populated regions of the world. Motivated by this, we have built and deployed one of the first operational measurements of OP in Europe at the National Observatory of Athens site in downtown Athens, Greece. OP for fine and coarse mode is measured using a semi-automated dithiothreitol (DTT) assay developed at the Georgia Institute of Technology; the assay measures the oxidation rate of DTT by water-soluble aerosol constituents, and simulates the rate at which the same compounds would deplete antioxidants in-vivo. The DTT oxidation rate per unit volume of air (water-soluble "DTT activity") and aerosol size class (fine, coarse) are used as a measure of aerosol toxicity. We present continuous (24hr average) OP measurements in downtown Athens from July 2016 to January 2017, conducted through quartz fiber filter analysis. The dataset covers a broad range of aerosol sources (pollution from Europe, regional and local biomass burning, dust, marine aerosol, biogenic aerosol) and meteorological conditions. The daily water-soluble DTT activity ranges between 0.02-0.81 nmolmin-1 m-3 (averaging at 0.24 nmolmin-1 m-3) for fine aerosol and between 0.01-0.52 nmolmin-1 m-3 (averaging at 0.08 nmolmin-1 m-3) for coarse particulate matter, indicating that water-soluble fine mode aerosol components possess a significant fraction of the OP. The seasonal variability demonstrates a higher DTT activity during the coldest period of the year for both

  18. Nested Potential Games

    OpenAIRE

    Hiroshi Uno

    2007-01-01

    This paper proposes a new class of potential games, the nested potential games, which generalize the potential games defined in Monderer and Shapley (1996), as well as the pseudo-potential games defined in Dubey et al. (2006). We show that each maximizer of a nested potential is a Nash equilibrium.

  19. In vitro, in vivo, and clinical studies of tedizolid to assess the potential for peripheral or central monoamine oxidase interactions.

    Science.gov (United States)

    Flanagan, S; Bartizal, K; Minassian, S L; Fang, E; Prokocimer, P

    2013-07-01

    Tedizolid phosphate is a novel oxazolidinone prodrug whose active moiety, tedizolid, has improved potency against Gram-positive pathogens and pharmacokinetics, allowing once-daily administration. Given linezolid warnings for drug-drug and drug-food interactions mediated by monoamine oxidase (MAO) inhibition, including sporadic serotonergic toxicity, these studies evaluated tedizolid for potential MAO interactions. In vitro, tedizolid and linezolid were reversible inhibitors of human MAO-A and MAO-B; the 50% inhibitory concentration (IC50) for tedizolid was 8.7 μM for MAO-A and 5.7 μM for MAO-B and 46.0 and 2.1 μM, respectively, with linezolid. Tedizolid phosphate was negative in the mouse head twitch model of serotonergic activity. Two randomized placebo-controlled crossover clinical studies assessed the potential of 200 mg/day tedizolid phosphate (at steady state) to enhance pressor responses to coadministered oral tyramine or pseudoephedrine. Sensitivity to tyramine was determined by comparing the concentration of tyramine required to elicit a ≥ 30-mmHg increase in systolic blood pressure (TYR30) when administered with placebo versus tedizolid phosphate. The geometric mean tyramine sensitivity ratio (placebo TYR30/tedizolid phosphate TYR30) was 1.33; a ratio of ≥ 2 is considered clinically relevant. In the pseudoephedrine study, mean maximum systolic blood pressure was not significantly different when pseudoephedrine was coadministered with tedizolid phosphate versus placebo. In summary, tedizolid is a weak, reversible inhibitor of MAO-A and MAO-B in vitro. Provocative testing in humans and animal models failed to uncover significant signals that would suggest potential for hypertensive or serotonergic adverse consequences at the therapeutic dose of tedizolid phosphate. Clinical studies are registered at www.clinicaltrials.gov as NCT01539473 (tyramine interaction study conducted at Covance Clinical Research Center, Evansville, IN) and NCT01577459

  20. Oxidative potential of ambient PM2.5 in the coastal cities of the Bohai Sea, northern China: Seasonal variation and source apportionment.

    Science.gov (United States)

    Liu, WeiJian; Xu, YunSong; Liu, WenXin; Liu, QingYang; Yu, ShuangYu; Liu, Yang; Wang, Xin; Tao, Shu

    2018-05-01

    Emissions of air pollutants from primary and secondary sources in China are considerably higher than those in developed countries, and exposure to air pollution is main risk of public health. Identifying specific particulate matter (PM) compositions and sources are essential for policy makers to propose effective control measures for pollutant emissions. Ambient PM 2.5 samples covered a whole year were collected from three coastal cities of the Bohai Sea. Oxidative potential (OP) was selected as the indicator to characterize associated PM compositions and sources most responsible for adverse impacts on human health. Positive matrix factorization (PMF) and multiple linear regression (MLR) were employed to estimate correlations of PM 2.5 sources with OP. The volume- and mass-based dithiothreitol (DTT v and DTT m ) activities of PM 2.5 were significantly higher in local winter or autumn (p  0.700, p water-soluble organic carbon (WSOC) and some transition metals. Using PMF, source fractions of PM 2.5 were resolved as secondary source, traffic source, biomass burning, sea spray and urban dust, industry, coal combustion, and mineral dust. Further quantified by MLR, coal combustion, biomass burning, secondary sources, industry, and traffic source were dominant contributors to the water-soluble DTT v activity. Our results also suggested large differences in seasonal contributions of different sources to DTT v variability. A higher contribution of DTT v was derived from coal combustion during the local heating period. Secondary sources exhibited a greater fraction of DTT v in summer, when there was stronger solar radiation. Traffic sources exhibited a prevailing contribution in summer, and industry contributed larger proportions in spring and winter. Future abatement priority of air pollution should reduce the sources contributing to OP of PM 2.5 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Effective potential for non-convex potentials

    International Nuclear Information System (INIS)

    Fujimoto, Y.; O'Raifeartaigh, L.; Parravicini, G.

    1983-01-01

    It is shown that the well-known relationship between the effective potential GAMMA and the vacuum graphs μ of scalar QFT follows directly from the translational invariance of the measure, and that it holds for all values of the fields phi if, and only if, the classical potential is convex. In the non-convex case μ appears to become complex for some values of phi, but it is shown that the complexity is only apparent and is due to the failure of the loop expansion. The effective potential actually remains real and well-defined for all phi, and reduces to μ in the neighbourhood of the classical minima. A number of examples are considered, notably potentials which are spontaneously broken. In particular the mechanism by which a spontaneous breakdown may be generated by radiative corrections is re-investigated and some new insights obtained. Finally, it is shown that the renormalization group equations for the parameters may be obtained by inspection from the effective potential, and among the examples considered are SU(n) fields and supermultiplets. In particular, it is shown that for supermultiplets the effective potential is not only real but positive. (orig.)

  2. Decrease of Na, K-ATPase Electrogenic Contribution and Resting Membrane Potential of Rat Soleus after 3 Days of Hindlimb Unloading

    Science.gov (United States)

    Krivoi, I. I.; Kravtsova, V. V.; Drabkina, T. M.; Prokofiev, A. V.; Nikolsky, E. E.; Shenkman, B. S.

    2008-06-01

    The Na,K-ATPase activity is critically important for excitability, electrogenesis and contractility of skeletal muscle expressing ? and ? isoforms of the enzyme [6, 9]. It is well known that disuse induced by hindlimb unloading (HU) leads to progressive atrophy of skeletal muscle; the muscle undergoes a number of dramatic remodeling events. In particular, changes in ion channel expression in response to muscle unweighting were observed [1, 8]. Decrease of resting membrane potential (RMP), electrogenic contribution of Na,K-ATPase and membrane resistance during 7-28 days of HU was shown [8, 10]. The intrinsic mechanisms involved in the process have not been revealed until present. At the same time, the understanding of these mechanisms could be crucial for the disclosing the mechanisms underlying the resting Ca2+ accumulation in the cytoplasm of the unloaded muscle [3, 7]. In the present study, the effect of early (3 days) HU-induced disuse of slow-twitch soleus muscle on membrane electrogenesis as well as on electrogenic contribution of Na,K-ATPase isoforms was investigated.

  3. Soils - Potential Runoff

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the spatial distribution of potential runoff-contributing areas in Kansas. Potential runoff-contributing areas...

  4. Crown Fire Potential

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

  5. Retail Spending Potential

    Data.gov (United States)

    City and County of Durham, North Carolina — This map shows the average household spending potential for retail goods in the United States in 2012. Spending potential data measures household consumer spending...

  6. Generalized Rosenbluth potentials

    International Nuclear Information System (INIS)

    Hassan, M.H.A.

    1977-05-01

    It is shown that the coefficients of friction and diffusion of the Balescu-Lenard equation can be derived from two ''generalized Rosenbluth potentials'', which reduce to the standard Rosenbluth potentials if wave effects are neglected. The potentials are evaluated explicitly in the case of Maxwellian field particles. The dominant contribution of wave effects to the potentials is due to the interaction of electron field particles with ion sound waves

  7. Application of potential

    International Nuclear Information System (INIS)

    Petris, L.

    1979-01-01

    This report summarizes the results obtained with the nucleon-nucleon potential presented previously for: 1) the deuteron properties and wave function, 2) a Hartree-Fock calculation on O 16 , and 3) the perturbation V-matrix and G-matrix results for the potential in relation to the results of other potentials and to saturation

  8. Super periodic potential

    Science.gov (United States)

    Hasan, Mohammd; Mandal, Bhabani Prasad

    2018-04-01

    In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.

  9. Generalized magnetic Rosenbluth potentials

    International Nuclear Information System (INIS)

    Hassan, M.H.A.

    1977-12-01

    It is shown that the coefficients of friction and diffusion of the magnetized Balescu-Lenard equation describing the interaction of ion test particles with electron field particles can be derived from two scalar potentials, which reduce to the potentials derived previously when wave effects are neglected. The parts of the potentials describing ''wave effects'' are evaluated explicitly in the case of Maxwellian electrons and the results are compared with the unmagnetized Rosenbluth potentials. The correction is dominant when eta=Ωsub(e)/ωsub(e)(>)1

  10. Quantum potential theory

    CERN Document Server

    Schürmann, Michael

    2008-01-01

    This volume contains the revised and completed notes of lectures given at the school "Quantum Potential Theory: Structure and Applications to Physics," held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald from February 26 to March 10, 2007. Quantum potential theory studies noncommutative (or quantum) analogs of classical potential theory. These lectures provide an introduction to this theory, concentrating on probabilistic potential theory and it quantum analogs, i.e. quantum Markov processes and semigroups, quantum random walks, Dirichlet forms on C* and von Neumann algebras, and boundary theory. Applications to quantum physics, in particular the filtering problem in quantum optics, are also presented.

  11. Handbook of interatomic potentials

    International Nuclear Information System (INIS)

    Stoneham, A.M.; Taylor, R.

    1981-08-01

    This Handbook collects together interatomic potentials for a large number of metals. Most of the potentials describe the interactions of host metal atoms with each other, and these, in some cases, may be applied to solid and liquid metals. In addition, there are potentials (a) for a metallic impurity alloyed with the host, (b) for a small number of chemical impurities in the metal (eg H, O), and (c) for rare-gas impurities, notably He. The Handbook is intended to be a convenient source of potentials for bulk, surface and defect calculations, both static and dynamic. (author)

  12. Examining Management Success Potential.

    Science.gov (United States)

    Quatrano, Louis A.

    The derivation of a model of management success potential in hospitals or health services administration is described. A questionnaire developed to assess management success potential in health administration students was voluntarily completed by approximately 700 incoming graduate students in 35 university health services administration programs…

  13. Pumping potential wells

    Science.gov (United States)

    Hershkowitz, N.; Forest, C.; Wang, E. Y.; Intrator, T.

    1987-01-01

    Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, such structures all must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well. Nevertheless, steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which 'pump' ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electro collecting anode in a relatively cold, low density multidipole plasma is considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two dimensional character of the problem is shown to be important.

  14. Pumping potential wells

    International Nuclear Information System (INIS)

    Hershkowitz, N.; Forest, C.; Wang, E.Y.; Intrator, T.

    1987-01-01

    Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, all such structures must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well. Nevertheless, steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which pump ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electron collecting anode in a relatively cold, low density, multidipole plasma are considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two-dimensional character of the problem is shown to be important

  15. Pumping potential wells

    International Nuclear Information System (INIS)

    Hershkowitz, N.; Forest, C.; Wang, E.Y.; Intrator, T.

    1987-01-01

    Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, such structures all must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well, but steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which 'pump' ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electron collecting anode in a relatively cold, low density multidipole plasma are considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two dimensional character of the problem is shown to be important. (author)

  16. Differences in motor evoked potentials induced in rats by transcranial magnetic stimulation under two separate anesthetics: implications for plasticity studies

    Directory of Open Access Journals (Sweden)

    Matthew Sykes

    2016-10-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS, a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when

  17. Differences in Motor Evoked Potentials Induced in Rats by Transcranial Magnetic Stimulation under Two Separate Anesthetics: Implications for Plasticity Studies.

    Science.gov (United States)

    Sykes, Matthew; Matheson, Natalie A; Brownjohn, Philip W; Tang, Alexander D; Rodger, Jennifer; Shemmell, Jonathan B H; Reynolds, John N J

    2016-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs) are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however, results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS), a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when selecting an

  18. The potential of renewable energy

    International Nuclear Information System (INIS)

    Piot, M.

    2007-01-01

    This article presents and comments on definitions of the potential of renewable forms of energy and, in a second part, takes a look at the potentials mentioned in the energy perspectives published by the Swiss Federal Office of Energy (SFOE). The following potentials are looked at: technical potential, ecological potential, economic potential, exploitable and expected potentials, technical, economic and ecological expansion potentials, potential of particular technologies in Switzerland, exploitable and expected expansion potential. Four scenarios for expansion potential are briefly described

  19. Oxidative potential of ambient fine aerosol over a semi-urban site in the Indo-Gangetic Plain

    Science.gov (United States)

    Patel, Anil; Rastogi, Neeraj

    2018-02-01

    Indo-Gangetic Plain (IGP) receives emissions from variety of pollutant sources such as post-harvest crop residue burning, vehicles, industries, power plants, and bio-fuel burning. Several studies have documented physical, chemical and optical properties of aerosol over the IGP; however, their oxidative potential (OP) has not yet documented. Present study reports the OP (measured through dithiothreitol (DTT) assay) of soluble particulate matter smaller than 2.5 μm aerodynamic diameter (PM2.5) over Patiala (30.3°N, 76.4°E, 249 m amsl), a semi-urban site located in the IGP, during winter 2014. Volume-normalized OP (range: 1.3-7.2 nmol DTT min-1 m-3, average: 3.8 ± 1.4, 1σ) is found to be ∼3 to 20 times higher, and mass-normalized OP (range: 13-50 pmol DTT min-1 μg-1, average: 27 ± 8, 1σ) is found to be similar or higher than those documented in literature. Further, observed OP is found to depend more on PM2.5 composition rather than mass concentration. Mass fractions of organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) correlate positively whereas that of secondary inorganic aerosol (SIA, sum of the concentrations of SO42-, NO3- and NH4+) correlate negatively with OP μg-1 at considerable significance level (p < 0.05). Negative correlation of SIA with OP μg-1 has been assessed in laboratory experiment and attributed to their DTT inactive nature. It is suggested to use WSOC/SIA ratio as a measure of DTT activity of secondary particles over the study region. Further, biomass burning derived species are observed to be more DTT active than those derived from fossil fuel burning. It was also observed that the slope of OP μg-1 and WSOC/SIA ratio linear relationship enhances significantly in samples collected during days following foggy nights in comparison to that in samples collected during non-foggy period, which may be due to the production of redox-active species by fog processing. Such studies have implications in assessing

  20. ICRF enhanced potentials

    International Nuclear Information System (INIS)

    Nelson, B.A.

    1987-01-01

    Ion-confining potentials in the Phaedrus tandem mirror are shown to be enhanced over Boltzmann-relations predicted values by radio-frequency (rf) waves in the ion cyclotron range of frequencies (ICRF). The ICRF enhanced potential is larger in the end cell with a lower passing density. Peak potential values decrease with increasing ion endloss current (or central cell density) for a constant rf capacitor bank voltage, and increase with increasing rf-capacitor bank voltage, for a constant ion endloss value (or central cell density). In fully axisymmetric operation, a potential peak is produced in an end cell by the central-cell rf, (with-out end-cell rf) and is found only in the end cell nearer the central-cell antenna. ICRF enhanced potentials are explained as an equilibrium between the electron-collisional filling-in rate and the electron pumping out rate provided by axial time-varying electric fields. Thermal barrier-like potential structures were found in the transition regions between the central cell and end cells, in the fully axisymmetric Phaedrus. Central-cell ICRF trapping effects combined with end-cell μΔ B forces create and pump the barrier potential wells

  1. Potential theory of radiation

    International Nuclear Information System (INIS)

    Chiu, Hueihuang.

    1989-01-01

    A theoretical method is being developed by which the structure of a radiation field can be predicted by a radiation potential theory, similar to a classical potential theory. The introduction of a scalar potential is justified on the grounds that the spectral intensity vector is irrotational. The vector is also solenoidal in the limits of a radiation field in complete radiative equilibrium or in a vacuum. This method provides an exact, elliptic type equation that will upgrade the accuracy and the efficiency of the current CFD programs required for the prediction of radiation and flow fields. A number of interesting results emerge from the present study. First, a steady state radiation field exhibits an optically modulated inverse square law distribution character. Secondly, the unsteady radiation field is structured with two conjugate scalar potentials. Each is governed by a Klein-Gordon equation with a frictional force and a restoring force. This steady potential field structure and the propagation of radiation potentials are consistent with the well known results of classical electromagnetic theory. The extension of the radiation potential theory for spray combustion and hypersonic flow is also recommended

  2. China's Military Potential

    National Research Council Canada - National Science Library

    Wortzel, Larry

    1998-01-01

    The People's Republic of China (PRC) is seen by many as an economic powerhouse with the world's largest standing military that has the potential to translate economic power into the military sphere...

  3. Some torsion potentials

    Energy Technology Data Exchange (ETDEWEB)

    Grundberg, J; Lindstrom, U

    1986-10-01

    Using the notion of torsion potentials, the duality between antisymmetric tensor fields and scalar fields is discussed. First-order actions with these fields, the connection and the metric as independent variables are presented.

  4. Abuse Potential of Pregabalin

    DEFF Research Database (Denmark)

    Schjerning, Ole; Rosenzweig, Mary; Pottegård, Anton

    2016-01-01

    BACKGROUND: Several case reports and epidemiological studies have raised concern about the abuse potential of pregabalin, the use of which has increased substantially over the last decade. Pregabalin is, in some cases, used for recreational purposes and it has incurred attention among drug abusers...... for causing euphoric and dissociative effects when taken in doses exceeding normal therapeutic dosages or used by alternative routes of administration, such as nasal insufflation or venous injection. The magnitude of the abuse potential and the mechanism behind it are not fully known. OBJECTIVE: The aim...... of this study was to present a systematic review of the data concerning the abuse potential of pregabalin. METHODS: We performed a systematic literature search and reviewed the preclinical, clinical and epidemiological data on the abuse potential of pregabalin. RESULTS: We included preclinical (n = 17...

  5. Elderberry: Botany, Horticulture, Potential

    Science.gov (United States)

    Horticultural Review allows extensive reviews of the state of the knowledge on certain topics or crops. Elderberry: Botany, Horticulture, Potential, is outlined with an Introduction, Botany, Horticulture, Propagation, Uses and Conclusion sections. This review compiles literature from around the w...

  6. Supersymmetrically transformed periodic potentials

    OpenAIRE

    C, David J. Fernandez

    2003-01-01

    The higher order supersymmetric partners of a stationary periodic potential are studied. The transformation functions associated to the band edges do not change the spectral structure. However, when the transformation is implemented for factorization energies inside of the forbidden bands, the final potential will have again the initial band structure but it can have bound states encrusted into the gaps, giving place to localized periodicity defects.

  7. Nucleus--nucleus potential

    International Nuclear Information System (INIS)

    Jaqaman, H.R.

    1977-01-01

    The nucleus--nucleus interaction is studied within the framework of the generator coordinate method that permits an easy incorporation of the full effects of antisymmetrization. It is found that the interaction, as far as the elastic scattering problem is concerned, can be described by a simple effective potential that is equivalent to the original many-body (and hence non-local) problem. The potential is obtained by dividing the wavefunction into a long-range part and a short-range part and requiring the former to satisfy a Schroedinger equation. This enables avoiding dealing with the troublesome short-range part of the wavefunction and provides a direct link with the optical model so that the potential obtained here is equivalent to the real part of the optical potential (the imaginary part is not investigated). The effective potential is found to consist of three parts: an interaction term between the nucleons belonging to different nuclei, a kinetic energy term due to the change in the intrinsic kinetic energy of the system as a result of the antisymmetrization, and finally an l-dependent part. The kinetic energy term is found to be very repulsive and effectively gives a hard core, and is calculated for the α--α and 16 O-- 16 O cases. The full potential is calculated for the α--α case for the S, D, and G partial waves and then used to calculate the corresponding phase shifts that are then compared with experimental results and other microscopic calculations. Finally, some recent results and analyses of fusion and deep inelastic reactions are reviewed that seem to indicate the presence of a hard core in the nucleus--nucleus potential. Such a hard core is present in the potential obtained in the sudden approximation

  8. Overview of interatomic potentials

    International Nuclear Information System (INIS)

    Bonny, G.; Malerba, L.

    2005-12-01

    In this report an overview on interatomic potentials is given. This overview is by no means complete and it has merely the intention to give the reader an idea of where interatomic potentials come from, as well as to provide the basic ideas behind some commonly used methods for deriving interatomic potentials for molecular dynamics applications. We start by giving a short introduction about the concept of interatomic potential in the framework of quantum mechanics, followed by a short description of commonly used methods for deriving semi-empirical interatomic potentials. After some short theoretical notions on each method, some practical parameterizations of commonly used potentials are given, including very recent ones. An effort has been made to classify existing approaches within a rational and consequent scheme, which is believed to be of use for a thorough comprehension of the topic. Although these approaches can be used in a variety of different materials, we will only discuss the practical cases of metals. Following this, some widespread ad hoc modification of the general methods are discussed. The report is concluded by a generalization of the methods to multi-component materials, in particular metallic alloys. (author)

  9. Assessing offshore wind potential

    International Nuclear Information System (INIS)

    Adelaja, Adesoji; McKeown, Charles; Calnin, Benjamin; Hailu, Yohannes

    2012-01-01

    Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.

  10. Forecasting potential crises

    International Nuclear Information System (INIS)

    Neufeld, W.P.

    1984-01-01

    Recently, the Trend Analysis Program (TAP) of the American Council of Life Insurance commissioned the Futures Group of Glastonbury, Connecticut, to examine the potential for large-scale catastrophic events in the near future. TAP was specifically concerned with five potential crises: the warming of the earth's atmosphere, the water shortage, the collapse of the physical infrastructure, the global financial crisis, and the threat of nuclear war. We are often unprepared to take action; in these cases, we lose an advantage we might have otherwise had. This is the whole idea behind forecasting: to foresee possibilities and to project how we can respond. If we are able to create forecasts against which we can test policy options and choices, we may have the luxury of adopting policies ahead of events. Rather than simply fighting fires, we have the option of creating a future more to our choosing. Short descriptions of these five potential crises and, in some cases, possible solutions are presented

  11. Potential for waste reduction

    International Nuclear Information System (INIS)

    Warren, J.L.

    1990-01-01

    The author focuses on wastes considered hazardous under the Resource Conservation and Recovery Act. This chapter discusses wastes that are of interest as well as the factors affecting the quantity of waste considered available for waste reduction. Estimates are provided of the quantities of wastes generated. Estimates of the potential for waste reduction are meaningful only to the extent that one can understand the amount of waste actually being generated. Estimates of waste reduction potential are summarized from a variety of government and nongovernment sources

  12. Robotics Potential Fields

    Directory of Open Access Journals (Sweden)

    Jordi Lucero

    2009-01-01

    Full Text Available This problem was to calculate the path a robot would take to navigate an obstacle field and get to its goal. Three obstacles were given as negative potential fields which the robot avoided, and a goal was given a positive potential field that attracted the robot. The robot decided each step based on its distance, angle, and influence from every object. After each step, the robot recalculated and determined its next step until it reached its goal. The robot's calculations and steps were simulated with Microsoft Excel.

  13. Neutron optical potentials

    International Nuclear Information System (INIS)

    Wilmore, D.; Hodgson, P.E.

    1976-01-01

    The purpose of this paper is to provide a guide to the use of optical model computer programs to analyse and calculate neutron data. After a brief discussion of the physical basis of the optical model a survey is given of the most widely used optical model and Hauser-Feshbach computer programs. The range of applicability and reliability of the major optical potentials proposed is assessed by comparison with available experimental data and some observations and suggestions are made for the optimum choice of optical potentials for given purposes of neutron data calculations. (author)

  14. The logarithmic potential

    CERN Document Server

    Evans, Griffith Conrad

    1927-01-01

    This book studies fundamental properties of the logarithmic potential and their connections to the theory of Fourier series, to potential theory, and to function theory. The material centers around a study of Poisson's integral in two dimensions and of the corresponding Stieltjes integral. The results are then extended to the integrals in terms of Green's functions for general regions. There are some thirty exercises scattered throughout the text. These are designed in part to familiarize the reader with the concepts introduced, and in part to complement the theory. The reader should know some

  15. Potential support ratios

    DEFF Research Database (Denmark)

    Kjærgaard, Søren; Canudas-Romo, Vladimir

    2017-01-01

    The ‘prospective potential support ratio’ has been proposed by researchers as a measure that accurately quantifies the burden of ageing, by identifying the fraction of a population that has passed a certain measure of longevity, for example, 17 years of life expectancy. Nevertheless......, the prospective potential support ratio usually focuses on the current mortality schedule, or period life expectancy. Instead, in this paper we look at the actual mortality experienced by cohorts in a population, using cohort life tables. We analyse differences between the two perspectives using mortality models...

  16. Deposition potential of polonium

    Energy Technology Data Exchange (ETDEWEB)

    Heal, H. G.

    1948-11-23

    The cathodic deposition potential for polonium in concentrations of 10{sup -13} normal and 8 x 10{sup -13} normal, the former being 100-fold smaller than the smallest concentrations previously studied, has been determined. The value is 0.64 volt on the hydrogen scale. Considering the various ways in which the graphs can reasonably be drawn, we consider the maximum possible error to be of the order of +- 0.03 volt. There is apparently no shift of deposition potential between concentrations of 10{sup -8} and 10{sup -13} normal, indicating that the Nernst equation is not applicable in these circumstances.

  17. Potentials of biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Munack, A.; Schroder, O. [Johann Heinrich von Thunen Inst., Braunschweig (Germany); Krahl, J. [Coburg Univ. of Applied Sciences, Coburg (Germany); Bunger, J. [Inst. for Prevention and Occupational Medicine of the German Social Accident Insurance, Ruhr-Univ. Inst., Bochum (Germany)

    2010-07-01

    This paper discussed the potential of biofuels with particular reference to the situation in Germany and Europe. Emphasis was on technical potential, such as biofuel production, utilization and environmental aspects. The Institute of Agricultural Technology and Biosystems Engineering ran vTI emission tests on diesel engines to evaluate the environmental impacts of biofuels. This testing facility is able to drive heavy-duty diesel engines in both stationary and dynamic test cycles, such as the European ESC and ETC. Additional analyses were conducted to determine the fine and ultra-fine particles, polycyclic aromatic hydrocarbons (PAH), aldehydes, ketones, and the usual regulated exhaust gas compounds. Ames tests were conducted to assess the mutagenic potential of tailpipe emissions. Previous study results showed that neat vegetable oils can render the exhaust high in mutagenic potency. Some of the non-regulated exhaust gas compounds were found to vary nonlinearly with the blend composition. B20 was found to have high mutagenic potential and was subject to sedimentation.

  18. Language as Pure Potential

    Science.gov (United States)

    Park, Joseph Sung-Yul

    2016-01-01

    Language occupies a crucial position in neoliberalism, due to the reimagination of language as commodified skill. This paper studies the role of language ideology in this transformation by identifying a particular ideology that facilitates this process, namely the ideology which views language as pure potential. Neoliberalism treats language as a…

  19. Iraq's Tourism Potential

    OpenAIRE

    Hooman Dabidian; Mohammed Wafaa Al-Ani; Christopher Hassaan Francke; Ahmed Redwan

    2013-01-01

    While it will require further political stability and security, tourism in Iraq stands to be a major growth sector. The Iraqi tourism sector is currently underdeveloped and in a state of neglect, due to decades of war, closed regimes and recurrent instability and insecurity. However, as Iraq continues to develop and stabilizes, it can begin to meet its tremendous potential as a global tour...

  20. Agreement of central site measurements and land use regression modeled oxidative potential of PM{sub 2.5} with personal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Aileen, E-mail: Yang@uu.nl [National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720BA Bilthoven (Netherlands); Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, P.O. Box 80.178, 3508TD Utrecht (Netherlands); Hoek, Gerard; Montagne, Denise [Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, P.O. Box 80.178, 3508TD Utrecht (Netherlands); Leseman, Daan L.A.C. [National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720BA Bilthoven (Netherlands); Hellack, Bryan [Air Quality & Sustainable Nanotechnology, Institute of Energy and Environmental Technology (IUTA), e.V., Blierheimer Str. 58-60, 47229 Duisburg (Germany); Kuhlbusch, Thomas A.J. [Air Quality & Sustainable Nanotechnology, Institute of Energy and Environmental Technology (IUTA), e.V., Blierheimer Str. 58-60, 47229 Duisburg (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Cassee, Flemming R. [National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720BA Bilthoven (Netherlands); Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, P.O. Box 80.178, 3508TD Utrecht (Netherlands); Brunekreef, Bert [Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, P.O. Box 80.178, 3508TD Utrecht (Netherlands); Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht (Netherlands); Janssen, Nicole A.H. [National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720BA Bilthoven (Netherlands)

    2015-07-15

    Oxidative potential (OP) of ambient particulate matter (PM) has been suggested as a health-relevant exposure metric. In order to use OP for exposure assessment, information is needed about how well central site OP measurements and modeled average OP at the home address reflect temporal and spatial variation of personal OP. We collected 96-hour personal, home outdoor and indoor PM{sub 2.5} samples from 15 volunteers living either at traffic, urban or regional background locations in Utrecht, the Netherlands. OP was also measured at one central reference site to account for temporal variations. OP was assessed using electron spin resonance (OP{sup ESR}) and dithiothreitol (OP{sup DTT}). Spatial variation of average OP at the home address was modeled using land use regression (LUR) models. For both OP{sup ESR} and OP{sup DTT}, temporal correlations of central site measurements with home outdoor measurements were high (R>0.75), and moderate to high (R=0.49–0.70) with personal measurements. The LUR model predictions for OP correlated significantly with the home outdoor concentrations for OP{sup DTT} and OP{sup ESR} (R=0.65 and 0.62, respectively). LUR model predictions were moderately correlated with personal OP{sup DTT} measurements (R=0.50). Adjustment for indoor sources, such as vacuum cleaning and absence of fume-hood, improved the temporal and spatial agreement with measured personal exposure for OP{sup ESR}. OP{sup DTT} was not associated with any indoor sources. Our study results support the use of central site OP for exposure assessment of epidemiological studies focusing on short-term health effects. - Highlights: • Oxidative potential (OP) of PM was proposed as a health-relevant exposure metric. • We evaluated the relationship between measured and modeled outdoor and personal OP. • Temporal correlations of central site with personal OP are moderate to high. • Adjusting for indoor sources improved the agreement with personal OP. • Our results

  1. Influence of Saharan dust outbreaks and carbon content on oxidative potential of water-soluble fractions of PM2.5 and PM10

    Science.gov (United States)

    Chirizzi, Daniela; Cesari, Daniela; Guascito, Maria Rachele; Dinoi, Adelaide; Giotta, Livia; Donateo, Antonio; Contini, Daniele

    2017-08-01

    Exposure to atmospheric particulate matter (PM) leads to adverse health effects although the exact mechanisms of toxicity are still poorly understood. Several studies suggested that a large number of PM health effects could be due to the oxidative potential (OP) of ambient particles leading to high concentrations of reactive oxygen species (ROS). The contribution to OP of specific anthropogenic sources like road traffic, biomass burning, and industrial emissions has been investigated in several sites. However, information about the OP of natural sources are scarce and no data is available regarding the OP during Saharan dust outbreaks (SDO) in Mediterranean regions. This work uses the a-cellular DTT (dithiothreitol) assay to evaluate OP of the water-soluble fraction of PM2.5 and PM10 collected at an urban background site in Southern Italy. OP values in three groups of samples were compared: standard characterised by concentrations similar to the yearly averages; high carbon samples associated to combustion sources (mainly road traffic and biomass burning) and SDO events. DTT activity normalised by sampled air volume (DTTV), representative of personal exposure, and normalised by collected aerosol mass (DTTM), representing source-specific characteristics, were investigated. The DTTV is larger for high PM concentrations. DTTV is well correlated with secondary organic carbon concentration. An increased DTTV response was found for PM2.5 compared to the coarse fraction PM2.5-10. DTTV is larger for high carbon content samples but during SDO events is statistically comparable with that of standard samples. DTTM is larger for PM2.5 compared to PM10 and the relative difference between the two size fractions is maximised during SDO events. This indicates that Saharan dust advection is a natural source of particles having a lower specific OP with respect to the other sources acting on the area (for water-soluble fraction). OP should be taken into account in epidemiological

  2. Development potential for hydropower

    International Nuclear Information System (INIS)

    Laufer, F.; Groetzinger, S.; Peter, M.; Schmutz, A.

    2004-11-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at the potential for the development of hydropower in Switzerland. The report updates the energy perspectives made ten years earlier. An overview of Swiss electricity production and consumption is presented and the proportion provided by hydropower is noted. Figures on installed capacity and import/export quantities are presented and discussed. Technological developments and the economical frameworks involved are discussed, as are regulatory measures that can be taken. Theoretical and technically realisable potentials for increased use of hydropower are discussed. The methods used to do this are examined. Strategies and measures to be taken are listed and discussed. An appendix includes data sheets on power plant modelling, including examples

  3. Scalar Potential Model progress

    Science.gov (United States)

    Hodge, John

    2007-04-01

    Because observations of galaxies and clusters have been found inconsistent with General Relativity (GR), the focus of effort in developing a Scalar Potential Model (SPM) has been on the examination of galaxies and clusters. The SPM has been found to be consistent with cluster cellular structure, the flow of IGM from spiral galaxies to elliptical galaxies, intergalactic redshift without an expanding universe, discrete redshift, rotation curve (RC) data without dark matter, asymmetric RCs, galaxy central mass, galaxy central velocity dispersion, and the Pioneer Anomaly. In addition, the SPM suggests a model of past expansion, past contraction, and current expansion of the universe. GR corresponds to the SPM in the limit in which a flat and static scalar potential field replaces the Sources and Sinks such as between clusters and on the solar system scale which is small relative to the distance to a Source. The papers may be viewed at http://web.infoave.net/˜scjh/ .

  4. Potentials Unbounded Below

    CERN Document Server

    Curtright, Thomas

    2011-01-01

    Continuous interpolates are described for classical dynamical systems defined by discrete time-steps. Functional conjugation methods play a central role in obtaining the interpolations. The interpolates corrrespond to particle motion in an underlying potential, V. Typically, V has no lower bound and can exhibit switchbacks wherein V changes form when turning points are encountered by the particle. The logistic map is used to illustrate these features.

  5. Exploring Vietnam's oil potential

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A brief review is given of the oil production potential in Vietnam. Since Since 1987, the country has been open to foreign investment in offshore exploration but has suffered from a US embargo on trade and economic ties. Nevertheless some exploration has occurred and twenty production sharing contracts with international oil companies has been signed. To date most of the finds have been non-commercial but optimism remains high. (U.K.)

  6. Nonadiabatic Ponderomotive Potentials

    International Nuclear Information System (INIS)

    Dodin IY, Fisch NJ

    2005-01-01

    An approximate integral of the Manley-Rowe type is found for a particle moving in a high-frequency field, which may interact resonantly with natural particle oscillations. An effective ponderomotive potential is introduced accordingly and can capture nonadiabatic particle dynamics. We show that nonadiabatic ponderomotive barriers can trap classical particles, produce cooling effect, and generate one-way walls for resonant species. Possible atomic applications are also envisioned

  7. POTENTIAL OF BUSINESS

    OpenAIRE

    Julija Avakumovic, Jelena Avakumovic

    2014-01-01

    Potential of businesses is available and relevant developed business opportunities which under certain conditions can affect the results of the business. Those are certain conditions possible exposure of the company. The success of a business depends of the knowledge of these resources and the way how to find the optimum combination of scale, structure and dynamics of available resources by the management of the business.

  8. Sicilian potential biogas production

    Directory of Open Access Journals (Sweden)

    Antonio Comparetti

    2013-09-01

    Full Text Available This study is aimed at predicting the Sicilian potential biogas production, using the Organic Fraction of Municipal Solid Waste (OFMSW, animal manure and food industry by-products, in a region where only one biogas plant using MSW and one co-digestion plant are nowadays available. The statistical data about OFMSW, the number of animals bred in medium and large farms and the amounts of by-products of food processing industries were evaluated, in order to compute the Sicilian potential biogas and energy production. The OFMSW produced in Sicily, that is 0.8 million tons ca. per year (37% of MSW, could be used in a bio-reactor, together with other raw materials, for Anaerobic Digestion (AD process, producing biogas and “digestate”. Moreover, 3.03 million tons ca. of manure, collected in medium and large animal husbandry farms (where cows, pigs and poultry are bred, and 350 thousand tons ca. of by-products, collected in food processing industries (pomace from olive oil mills and grape marc from wineries, might be used for AD process. The Sicilian potential biogas production from the AD of the above raw materials is 170.2 millions of m3, that is equal to 1023.4 GWh of energy per year, of which 484 GWh from animal manure, 303 GWh from OFMSW and 236.4 GWh from food industry by-products. The highest biogas production is in the province of Palermo (35.6 millions of m3, Ragusa (30.8 millions of m3 and Catania (22.8 millions of m3, having a potential energy production of 213.8, 185 and 137 GWh, respectively.

  9. Compact Polarimetry Potentials

    Science.gov (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric

    2011-01-01

    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  10. Thermodynamics extends economics potentials

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, Alexander V. [Kiev Technical Univ., Dept. of Marketing and Management, Kiev (Ukraine); Brodiansky, Victor M. [Moscow Energy Inst., Dept. of Cryogen Machines, Moscow (Russian Federation)

    2001-08-01

    In this paper we consider the use of exergy in economic valuation and its correlation with money. Exergy-based determination of production expenses provides a new base for 'natural' price determination. A new macroeconomic dynamics approach based on this correlation is proposed. This method is relatively general because it is not restricted by certain assumptions used in traditional economic analysis. The exergy model of macroeconomic dynamics was tested by utilizing data from the US economy. This test, covering a period of about 25 years, confirms this approach and opens new potentials in economic analysis. (Author)

  11. ICT Enhanced Buildings Potentials

    DEFF Research Database (Denmark)

    Christiansson, Per

    2007-01-01

    component systems that are accessed and integrated in the real world of building use in different contexts. The ICT systems may be physically or virtually embedded in the building. Already in 1982 AT&T established the 'intelligent buildings', IB, concept due to marketing reasons and the Informart building...... with focus on virtual building models support, new services and user environment definitions and development, virtual spaces and augmented reality, intelligent building components, application ontologies, and ICT systems integration to illustrate ICT enhanced buildings potentials and R&D needs.  ...

  12. Pion nucleus optical potential

    International Nuclear Information System (INIS)

    Kam, J. de.

    1981-01-01

    The main goal of the investigations, presented is to establish the contributions to the optical potential, coming from scattering processes which involve 1p-1h nuclear states in the intermediate scattering system. The effects of the Pauli principle corrections and the binding corrections are studied in detail. A phenomenological study of pion absorption effects is also presented. The calculations all concern π- 4 He scattering. The simplicity of the 4 He structure makes the π- 4 He system quite an ideal tool for studying the reaction mechanism. (Auth.)

  13. A crafting of potentials

    DEFF Research Database (Denmark)

    Kilbourn, Kyle

    In the movement from understanding the past towards creating the future design anthropology, as a discipline, will turn from one with archival qualities to one endowed with potentials for change. One challenge facing design anthropology is how to show relevance for theory generation while also in......-as is complemented by designing for as design anthropologists stage design workshops, span knowledge traditions, and make design moves. Reflecting on my own research process, I trace a few research tools that underline the craft of design anthropology....

  14. On chemical potential

    International Nuclear Information System (INIS)

    Araki, H.

    1981-01-01

    In the framework of the C*-algebra formalism of quantum statistical mechanics, the concept of chemical potential or its vector generalization in the case of an arbitrary (not necessarily abelian) separable compact gauge group (of the first kind) is described as an algebraic label of equilibrium states at a given inverse temperature β. It is mathematically attained by extending a (clustering) KMS state of the gauge-invariant part of a C*-algebra F to a state of F and by examining the KMS property of the extension. (Auth.)

  15. Task-dependent inhibition of slow-twitch soleus and excitation of fast-twitch gastrocnemius do not require high movement speed and velocity-dependent sensory feedback

    Directory of Open Access Journals (Sweden)

    Ricky eMehta

    2014-10-01

    Full Text Available Although individual heads of triceps surae, soleus (SO and medial gastrocnemius (MG muscles, are often considered close functional synergists, previous studies have shown distinct activity patterns between them in some motor behaviors. The goal of this study was to test two hypotheses explaining inhibition of slow SO with respect to fast MG: (1 inhibition occurs at high movement velocities and mediated by velocity-dependent sensory feedback and (2 inhibition depends on the ankle-knee joint moment combination and does not require high movement velocities. The hypotheses were tested by comparing the SO EMG/MG EMG ratio during fast and slow motor behaviors (cat paw shake responses vs. back, straight leg load lifting in humans, which had the same ankle extension-knee flexion moment combination; and during fast and slow behaviors with the ankle extension-knee extension moment combination (human vertical jumping and stance phase of walking in cats and leg load lifting in humans. In addition, SO EMG/MG EMG ratio was determined during cat paw shake responses and walking before and after removal of stretch velocity-dependent sensory feedback by self-reinnervating SO and/or gastrocnemius. We found the ratio SO EMG/MG EMG below 1 (p<0.05 during fast paw shake responses and slow back load lifting, requiring the ankle extension-knee flexion moment combination; whereas the ratio SO EMG/MG EMG was above 1 (p<0.05 during fast vertical jumping and slow tasks of walking and leg load lifting, requiring ankle extension-knee extension moments. Removal of velocity-dependent sensory feedback did not affect the SO EMG/MG EMG ratio in cats. We concluded that the relative inhibition of SO does not require high muscle velocities, depends on ankle-knee moment combinations, and is mechanically advantageous for allowing a greater MG contribution to ankle extension and knee flexion moments.

  16. On quantum potential dynamics

    International Nuclear Information System (INIS)

    Goldstein, Sheldon; Struyve, Ward

    2015-01-01

    Non-relativistic de Broglie–Bohm theory describes particles moving under the guidance of the wave function. In de Broglie's original formulation, the particle dynamics is given by a first-order differential equation. In Bohm's reformulation, it is given by Newton's law of motion with an extra potential that depends on the wave function—the quantum potential—together with a constraint on the possible velocities. It was recently argued, mainly by numerical simulations, that relaxing this velocity constraint leads to a physically untenable theory. We provide further evidence for this by showing that for various wave functions the particles tend to escape the wave packet. In particular, we show that for a central classical potential and bound energy eigenstates the particle motion is often unbounded. This work seems particularly relevant for ways of simulating wave function evolution based on Bohm's formulation of the de Broglie–Bohm theory. Namely, the simulations may become unstable due to deviations from the velocity constraint. (paper)

  17. The potentialities of terrorism

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1976-01-01

    The potential hazard of terrorists obtaining plutonium and building a nuclear device is examined within the perspective of other terrorist activities. Various sources are quoted on the possibility of a terrorist group having the resources, including skilled personnel, to build a bomb. The potential damage engendered by such a device is hypothesized to be less than that of many other terrorist actions which could be easily accomplished. Other activities, poison or nerve gas, gasoline dropped on a football stadium, destruction of a large dam, poisoning food or water supply and armed action against a tanker carrying liquefied natural gas, are cited as examples of terrorist incidents more devastating than building a crude plutonium bomb. Resistance to blackmail strategies is seen as the only reliable way to thwart their activities in the long run. Although plutonium must be guarded carefully, it is demonstrated as being far from the only or most devastating means of blackmail. It is concluded that the threat of terrorist activities is being used by anti-nuclear groups to support emotionally based dislike of nuclear power. (J.T.A.)

  18. Cosmology with exponential potentials

    International Nuclear Information System (INIS)

    Kehagias, Alex; Kofinas, Georgios

    2004-01-01

    We examine in the context of general relativity the dynamics of a spatially flat Robertson-Walker universe filled with a classical minimally coupled scalar field φ of exponential potential V(φ) ∼ exp(-μφ) plus pressureless baryonic matter. This system is reduced to a first-order ordinary differential equation for Ω φ (w φ ) or q(w φ ), providing direct evidence on the acceleration/deceleration properties of the system. As a consequence, for positive potentials, passage into acceleration not at late times is generically a feature of the system for any value of μ, even when the late-times attractors are decelerating. Furthermore, the structure formation bound, together with the constraints Ω m0 ∼ 0.25 - 0.3, -1 ≤ w φ0 ≤ -0.6, provides, independently of initial conditions and other parameters, the necessary condition 0 N , while the less conservative constraint -1 ≤ w φ ≤ -0.93 gives 0 N . Special solutions are found to possess intervals of acceleration. For the almost cosmological constant case w φ ∼ -1, the general relation Ω φ (w φ ) is obtained. The generic (nonlinearized) late-times solution of the system in the plane (w φ , Ω φ ) or (w φ , q) is also derived

  19. Evaluation of hydrocarbon potential

    International Nuclear Information System (INIS)

    Cashman, P.H.; Trexler, J.H. Jr.

    1992-01-01

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the open-quotes Eleana Formationclose quotes are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock

  20. International Evoked Potentials Symposium

    CERN Document Server

    1980-01-01

    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  1. Radiosensitizers: rationale and potential

    International Nuclear Information System (INIS)

    Brown, J.M.

    1981-01-01

    This paper briefly reviews agents that are capable of sensitizing hypoxic cells to radiation and chemotherapeutic agents. The first part is a synopsis of the development of hypoxic radiosensitizers, which concludes that misonidazole can be effective against human tumors. Unfortunately, neurotoxicity limits its effectiveness in humans because the dose that can be given in conjunction with daily fractionated radiation is five to ten times lower than is required for full radiosensitization of the hypoxic cells. The second part covers our recent efforts to develop a drug that does not produce such limiting neurotoxicity. The primary rationale of our program was to synthesize a drug with a short plasma half-life that was too hydrophilic to cross the blood-brain barrier but was able to penetrate tumors and radiosensitize hypoxic cells. From this program, a new drug, SR-2508, has been found that is as efficient as misonidazole in its radiosensitizing ability, but is four to ten times less toxic. Finally, the potential of radiosensitizers not only as agents that can sensitize tumor cells to radiation, but also as agents that can specifically sensitize tumors to chemotherapeutic agents, is discussed. In addition, these drugs may be potential cytotoxic agents that produce toxicity only in solid tumors

  2. CLIC Physics Potential

    CERN Document Server

    Pandurovic, Mila

    2017-01-01

    The CLICdp is an international collaboration that investigates the physics potential of the Compact Linear Collider (CLIC) and performs research and development of the CLIC detector. CLIC is a future multi-TeV linear electron-positron collider, designed to cover a physics program of the Standard model physics, with the emphasis on Higgs and top as well as to address the wide range of open questions of the phenomena beyond the Standard model with high precision. The CLIC is designed to be build and operated at three discrete energy stages, sort(s) = 380 GeV, 1.5 and 3.0 TeV, which are optimized for the foreseen physics program. In this talk the CLIC accelerator, detector and experimental environment of CLIC will be presented, as well as, the number of the full-simulation measurements in the Higgs, top and beyond Standard model sector, presenting the capabilities of CLIC for high precision measurements.

  3. The effective nuclear potential

    International Nuclear Information System (INIS)

    Skyrme, T.H.R.

    1994-01-01

    An empirical analyses is made of the mean effective internucleon potential required in the shell-model description of nuclei, allowing for the presence of many-body effects as suggested by current theory. A consistent description is found in which the effective two-body interaction acts almost entirely in even states, and the many-body effects are simulated by a repulsive three-body contact interaction. The strength of the two-body interaction is consistent with that expressed by the free scattering matrix of the two-nucleon system, and that of the three-body interaction with the 'rearrangement energy' calculated in the many-body theory. (author). 21 refs, 2 figs, 7 tabs

  4. Potential for nuclear terrorism

    International Nuclear Information System (INIS)

    Jenkins, B.M.

    1977-05-01

    The question of whether or not terrorists will ''go nuclear'' is discussed. It is possible, although there is no historical evidence that any criminal or terrorist group ever made any attempt to acquire nuclear material for use in an explosive or dispersal device. In terms of intentions, psychotics are potential nuclear terrorists, but in terms of capabilities, they are the farthest away from being able to acquire a nuclear weapon. The history of nuclear incidents in the U.S. and abroad is reviewed. As the nuclear industry expands, the number of low-level incidents (bomb threats, pilferage, etc.) will increase also, but not necessarily escalate to more serious incidents. Terrorists may ''go nuclear'' solely for the publicity value; nuclear hoaxes may be attenpted. Nuclear terrorism seems more attractive as a threat than as an action. But the nature of the threat may change in the future, and the danger of imitation of a successful nuclear terrorist act is pointed out

  5. Corrosion potential analysis system

    Science.gov (United States)

    Kiefer, Karl F.

    1998-03-01

    Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately

  6. Assessing the cytotoxicity of ambient particulate matter (PM) using Chinese hamster ovary (CHO) cells and its relationship with the PM chemical composition and oxidative potential

    Science.gov (United States)

    Wang, Yixiang; Plewa, Michael J.; Mukherjee, Ujjal Kumar; Verma, Vishal

    2018-04-01

    We assessed mammalian cell cytotoxicity of ambient PM2.5 and investigated its association with the oxidative potential (OP) and chemical composition of the particles. Sixteen PM samples spanning in various seasons (fall, winter, spring and summer) were collected from an urban site in central Illinois. Cytotoxicity (LC50) in terms of the volume of air that kills 50% of the cells were calculated, which varied from 4.3 to 7.2 m3 of air. The OP was measured by two assays - the dithiothreitol (DTT) and the surrogate lung fluid (SLF) assay. In DTT assay, we measured two endpoints - hydroxyl radicals (•OH) generation and DTT consumption (the conventionally measured endpoint), while only •OH generation was measured in the SLF assay. Although, all three endpoints in the OP assays correlated significantly (P ≤ 0.05) with LC50, the correlation of reactive oxygen species (ROS) generation in DTT and SLF assays was much higher (r > 0.80 for •OH generation versus LC50) than the DTT consumption (r = 0.58). To further understand the components in PM that drive cytotoxicity and OP, concentration of water-soluble metals (Fe, Cu, Co, Cr, Mn, Ni, Pb, V, Hg, and Zn), organic carbon (OC), water soluble organic carbon (WSOC), and elemental carbon (EC) were measured. Among all the chemical components, Fe, Cu and WSOC correlated most (r > 0.70; P ≤ 0.01) with the cytotoxicity. DTT consumption correlated only with OC and WSOC (r > 0.80; P ≤ 0.01), while •OH generation in DTT and SLF assay correlated with both WSOC (r > 0.70; P ≤ 0.01) and metals (i.e. Fe and Cu; r > 0.75; P ≤ 0.01). Our results suggest a strong link between the PM2.5 OP and its cytotoxicity. Furthermore, the synergistic interactions among the organic compounds (i.e. WSOC) and metals (Fe and Cu) to enhance the ROS generation, which are more effectively captured in •OH generation endpoints in DTT and SLF assay than the DTT consumption, appear to be largely responsible for the observed mammalian cell

  7. Pseudo potentials and model potentials in atomic collisions

    International Nuclear Information System (INIS)

    Reyes, O.; Jouin, H.; Fuentealba, P.

    1988-01-01

    In this work, it is discussed the main differences between the use of pseudo-potentials and model potentials in collision problems . It is shown the potential energy curves for distinct systems obtained with both kinds of potentials. (A.C.A.S.) [pt

  8. Bioremedication: Potentials and pitfalls

    International Nuclear Information System (INIS)

    Nichols, A.B.

    1992-01-01

    The three main types of marine oil spill bioremediation involve fertilizers, seeding, and open-water applications. Fertilizers contain nutrients that trigger the growth of indigenous oil-degrading microorganisms. Seeding involves adding exogenous microbes to an oiled environment to promote increased biodegradation rates. The effectiveness of using either seeding or fertilizers in the open ocean has not been well established and most of the scientific community and many oil professionals remain skeptical about the utility of bioremediation at sea because rigorously controlled and documented experiments have not yet been done. Several companies have advocated using bioremediation for open ocean oil spills, but they have not yet produced convincing evidence that their products work as claimed. A potentially significant problem at sea is keeping the microorganisms in contact with the oil long enough for degradation to occur. The jury is still out regarding regulatory and public acceptance of bioremediation as a technique to clean up oil spills in general. Commercialization of bioremediation products is hindered by lack of protocols for testing and approval, although efforts are underway to devise such mechanisms

  9. Quantum potentiality revisited

    Science.gov (United States)

    Jaeger, Gregg

    2017-10-01

    Heisenberg offered an interpretation of the quantum state which made use of a quantitative version of an earlier notion, , of Aristotle by both referring to it using its Latin name, potentia, and identifying its qualitative aspect with . The relationship between this use and Aristotle's notion was not made by Heisenberg in full detail, beyond noting their common character: that of signifying the system's objective capacity to be found later to possess a property in actuality. For such actualization, Heisenberg required measurement to have taken place, an interaction with external systems that disrupts the otherwise independent, natural evolution of the quantum system. The notion of state actualization was later taken up by others, including Shimony, in the search for a law-like measurement process. Yet, the relation of quantum potentiality to Aristotle's original notion has been viewed as mainly terminological, even by those who used it thus. Here, I reconsider the relation of Heisenberg's notion to Aristotle's and show that it can be explicated in greater specificity than Heisenberg did. This is accomplished through the careful consideration of the role of potentia in physical causation and explanation, and done in order to provide a fuller understanding of this aspect of Heisenberg's approach to quantum mechanics. Most importantly, it is pointed out that Heisenberg's requirement of an external intervention during measurement that disrupts the otherwise independent, natural evolution of the quantum system is in accord with Aristotle's characterization of spontaneous causation. Thus, the need for a teleological understanding of the actualization of potentia, an often assumed requirement that has left this fundamental notion neglected, is seen to be spurious. This article is part of the themed issue `Second quantum revolution: foundational questions'.

  10. RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner

    2012-03-31

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of

  11. Quantum potentiality revisited.

    Science.gov (United States)

    Jaeger, Gregg

    2017-11-13

    Heisenberg offered an interpretation of the quantum state which made use of a quantitative version of an earlier notion, [Formula: see text], of Aristotle by both referring to it using its Latin name, potentia , and identifying its qualitative aspect with [Formula: see text] The relationship between this use and Aristotle's notion was not made by Heisenberg in full detail, beyond noting their common character: that of signifying the system's objective capacity to be found later to possess a property in actuality. For such actualization, Heisenberg required measurement to have taken place, an interaction with external systems that disrupts the otherwise independent, natural evolution of the quantum system. The notion of state actualization was later taken up by others, including Shimony, in the search for a law-like measurement process. Yet, the relation of quantum potentiality to Aristotle's original notion has been viewed as mainly terminological, even by those who used it thus. Here, I reconsider the relation of Heisenberg's notion to Aristotle's and show that it can be explicated in greater specificity than Heisenberg did. This is accomplished through the careful consideration of the role of potentia in physical causation and explanation, and done in order to provide a fuller understanding of this aspect of Heisenberg's approach to quantum mechanics. Most importantly, it is pointed out that Heisenberg's requirement of an external intervention during measurement that disrupts the otherwise independent, natural evolution of the quantum system is in accord with Aristotle's characterization of spontaneous causation. Thus, the need for a teleological understanding of the actualization of potentia, an often assumed requirement that has left this fundamental notion neglected, is seen to be spurious.This article is part of the themed issue 'Second quantum revolution: foundational questions'. © 2017 The Author(s).

  12. Solar potential in Turkey

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol

    2005-01-01

    Most of the locations in Turkey receive abundant solar-energy, because Turkey lies in a sunny belt between 36 deg. and 42 deg. N latitudes. Average annual temperature is 18 to 20 deg. C on the south coast, falls to 14-16 deg. C on the west coat, and fluctuates between 4 and 18 deg. C in the central parts. The yearly average solar-radiation is 3.6 kW h/m 2 day, and the total yearly radiation period is ∼2610 h. In this study, a new formulation based on meteorological and geographical data was developed to determine the solar-energy potential in Turkey using artificial neural-networks (ANNs). Scaled conjugate gradient (SCG), Pola-Ribiere conjugate gradient (CGP), and Levenberg-Marquardt (LM) learning algorithms and logistic sigmoid (logsig) transfer function were used in the networks. Meteorological data for last four years (2000-2003) from 12 cities (Canakkale, Kars, Hakkari, Sakarya, Erzurum, Zonguldak, Balikesir, Artvin, Corum, Konya, Siirt, and Tekirdag) spread over Turkey were used in order to train the neural-network. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine-duration, and mean temperature) are used in the input layer of the network. Solar-radiation is in the output layer. The maximum mean absolute percentage error was found to be less than 3.832% and R 2 values to be about 99.9738% for the selected stations. The ANN models show greater accuracy for evaluating solar-resource possibilities in regions where a network of monitoring stations has not been established in Turkey. This study confirms the ability of the ANN to predict solar-radiation values accurately

  13. Potentials of fissioning plasmas

    International Nuclear Information System (INIS)

    Karlheinz, Thom.

    1979-01-01

    Successful experiments with the nuclear pumping of lasers have demonstrated that in gaseous medium the kinetic energy of fission fragments can be converted directly into non-equilibrium optical radiation. This confirms the concept that the fissioning medium in a gas-phase nuclear reactor shows an internal structure such as a plasma in nearly thermal equilibrium varying up to a state of extreme-non-equilibrium. The accompanying variations of temperatures, pressure and radiative spectrum suggest wide ranges of applications. For example, in the gas-phase fission reactor concept enriched uranium hexafluoride or an uranium plasma replaces conventional fuel elements and permits operation above the melting point of solid materials. This potential has been motivation for the US National Aeronautics and Space Administration (NASA) to conduct relevant research for high specific impulse propulsion in space. The need to separate the high temperature gaseous fuel from the surfaces of a containing vessel and to protect them against thermal radiation has led to the concept of an externally moderated reactor in which the fissioning gaseous material is suspended by fluid dynamic means and the flow of opaque buffer gas removes the power. The gaseous nuclear fuel can slowly be circulated through the reactor for continuous on-site reprocessing including the annihilation of transuranium actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides can thus be achieved. These characteristics and the unique radiative properties led to the expectation that the gas-phase fission reactor could feature improved safety, safeguarding and economy, in addition to new technologies such as processing, photochemistry and the transmission of power over large distances in space

  14. Toxic potential of palytoxin.

    Science.gov (United States)

    Patocka, Jiří; Gupta, Ramesh C; Wu, Qing-hua; Kuca, Kamil

    2015-10-01

    This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

  15. On the scalar potential models from the isospectral potential class

    Energy Technology Data Exchange (ETDEWEB)

    Lima, V. Gomes [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Fisica; Santos, V. Silva [Paraiba Univ., Campina Grande, PB (Brazil). Dept. de Engenharia Civil; Rodrigues, R. de Lima [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: rafaelr@cbpf.br

    2001-10-01

    The static field classical configuration in (1+1)-dimensions for new non-linear potential models is investigated from an isospectral potential class and the concept of bosonic zero mode solution. One of the models considered here has a static nontopological configuration with a single vacuum state, whose potential in the stability equation corresponds to broken a supersymmetry. (author)

  16. PV potential and potential PV rent in European regions

    DEFF Research Database (Denmark)

    Hansen, Anders Chr.; Thorn, Paul

    2013-01-01

    The paper provides a GIS based model for assessing the potentials of photovoltaic electricity in Europe by NUTS 2 regions. The location specific energy potential per PV-­‐panel area is estimated based on observations of solar irradiation, conversion efficiency, levelised costs and the social value...... of PV-­‐electricity. Combined with the potential density of PV-­‐panel area based on land cover and environental restrictions, the PV energy potential and the potential PV ressource rent is calculated. These calculations enbable the model to estimate the regional patterns at NUTS 2 level...

  17. An improved potential for krypton

    International Nuclear Information System (INIS)

    Aziz, R.A.

    1979-01-01

    An improved potential for krypton is presented. It has the simple but realistic form used by Aziz and Chen for argon based on the HFD potential suggested by Ahlrichs et.al. The potential, with known long-range behaviour, was fitted to second virial, viscosity and thermal conductivity data. The potential appears to have the best overall predictive ability for dilute gas, bulk and microscopic data. (author)

  18. Instantons and the interquark potential

    International Nuclear Information System (INIS)

    McDougall, N.A.

    1980-01-01

    It is argued that the contributions to the interquark potential from instantons of all scale sizes may be calculated in a consistent, cut-off-independent manner using the dilute-gas approximation; and that an interquark potential dominated at intermediate distances by these contributions is similar to already successful phenomenological potentials. (orig.)

  19. Potentials of surfaces in space

    International Nuclear Information System (INIS)

    Whipple, E.C.

    1981-01-01

    The potential of a body in space is determined by a balance between various charging currents such as the transfer of charge from plasma particles, photoemission, and secondary electron emission. These processes are evaluated for bodies in the solar system and in interstellar space under the headings; an overview of charging, survey of early work on charging, charging processes, effects of non-isotropic plasmas and magnetic and electric fields, calculation of surface potentials, differential charging, potential barriers and discharge processes, measurements of potential, potential modification and control on spacecraft, and astrophysical applications. (U.K.)

  20. Measurement of proton autoneutralization potential

    International Nuclear Information System (INIS)

    Garcia, M.

    1984-09-01

    A proton space charge having multi-MeV kinetic energy was injected through a thin ground plane to extract electrons and produce a time-dependent autoneutralization space potential. An electon-emitting floating-potential resistive divider was used to measure the space potential during 20 ns of the proton current pulse. During this time, proton kinetic energy fell from 10.6 MeV to 8.5 MeV and thus the space potential (taken as 1.09 x the floating potential) fell from 5.8 kV to 4.6 kV

  1. Pair potentials in liquid metals

    International Nuclear Information System (INIS)

    Faber, T.E.

    1980-01-01

    The argument which justifies the use of a pair potential to describe the structure-dependent term in the energy of liquid metals is briefly reviewed. Because there is an additional term in the energy which depends upon volume rather than structure, and because the pair potential itself is volume-dependent, the relationship between pair potential and observable properties such as pressure, bulk modulus and pair distribution function is more complicated for liquid metals than it is for molecular liquids. Perhaps for this reason, the agreement between pair potentials inferred from observable properties and pair potentials calculated by means of pseudo-potential theory is still far from complete. The pair potential concept is applicable only to simple liquid metals, in which the electron-ion interaction is weak. No attempt is made to discuss liquid transition and rare-earth metals, which are not simple in this sense. (author)

  2. State-dependent classical potentials

    International Nuclear Information System (INIS)

    D'Amico, M.

    2001-01-01

    As alternative treatment to the potential operators of standard quantum mechanics is presented. The method is derived from Bohm's mechanics. The operator scalar (V) and vector (A) potential functions are replaced by a quantum potential. It is argued that the classical potential is a special limiting case of a more general quantum potential. The theory is illustrated by deriving an equivalent single-particle equation for the i-th particle of an n-body Bohmian system. The resulting effective state-dependent potential holds the interaction between the single-particle self-wave ψ s and the environment wave ψ e of the n - 1 remaining particles. The effective state-dependent potential is offered as a resolution to the Aharonov-Bohm effect where the phase difference is shown to result from the presence of ψ e . Finally, the interaction between ψ s and ψ e is illustrated graphically

  3. Calcium currents in a fast-twitch skeletal muscle of the rat

    OpenAIRE

    1983-01-01

    Slow ionic currents were measured in the rat omohyoid muscle with the three-microelectrode voltage-clamp technique. Sodium and delayed rectifier potassium currents were blocked pharmacologically. Under these conditions, depolarizing test pulses elicited an early outward current, followed by a transient slow inward current, followed in turn by a late outward current. The early outward current appeared to be a residual delayed rectifier current. The slow inward current was identified as a calci...

  4. Information Overload in Group Communication: From Conversation to Cacophony in the Twitch Chat

    OpenAIRE

    Nematzadeh, Azadeh; Ciampaglia, Giovanni Luca; Ahn, Yong-Yeol; Flammini, Alessandro

    2016-01-01

    Online communication channels, especially social web platforms, are rapidly replacing traditional ones. Online platforms allow users to overcome physical barriers, enabling worldwide participation. However, the power of online communication bears an important negative consequence --- we are exposed to too much information to process. Too many participants, for example, can turn online public spaces into noisy, overcrowded fora where no meaningful conversation can be held. Here we analyze a la...

  5. Protein metabolism in slow- and fast-twitch skeletal muscle during turpentine-induced inflammation.

    Science.gov (United States)

    Muthny, Tomas; Kovarik, Miroslav; Sispera, Ludek; Tilser, Ivan; Holecek, Milan

    2008-02-01

    The aim of our study was to evaluate the differences in protein and amino acid metabolism after subcutaneous turpentine administration in the soleus muscle (SOL), predominantly composed of red fibres, and the extensor digitorum longus muscle (EDL) composed of white fibres. Young rats (40-60 g) were injected subcutaneously with 0.2 ml of turpentine oil/100 g body weight (inflammation) or with the same volume of saline solution (control). Twenty-four hours later SOL and EDL were dissected and incubated in modified Krebs-Heinseleit buffer to estimate total and myofibrillar proteolysis, chymotrypsin-like activity of proteasome (CHTLA), leucine oxidation, protein synthesis and amino acid release into the medium. The data obtained demonstrate that in intact rats, all parameters measured except protein synthesis are significantly higher in SOL than in EDL. In turpentine treated animals, CHTLA increased and protein synthesis decreased significantly more in EDL. Release of leucine was inhibited significantly more in SOL. We conclude that turpentine-induced inflammation affects more CHTLA, protein synthesis and leucine release in EDL compared to SOL.

  6. Does metabosensitive afferent fibers activity differ from slow- and fast-twitch muscles?

    Science.gov (United States)

    Caron, Guillaume; Decherchi, Patrick; Marqueste, Tanguy

    2015-09-01

    This study was designed to investigate the metabosensitive afferent response evoked by electrically induced fatigue (EIF), lactic acid (LA) and potassium chloride (KCl) in three muscle types. We recorded the activity of groups III-IV afferents originating from soleus, gastrocnemius and tibialis anterior muscles. Our data showed a same pattern of response in the three muscles after chemical injections, i.e., a bell curve with maximal discharge rate at 1 mM for LA injections and a linear relationship between KCl concentrations and the afferent discharge rate. Furthermore, a stronger response was recorded after EIF in the gastrocnemius muscle compared to the two other muscles. The change in afferent discharge after 1 mM LA injection was higher for the gastrocnemius muscle compared to the response obtained with the corresponding concentration applied in the two other muscles, whereas changes to KCl injections did not dramatically differ between the three muscles. We conclude that anatomical (mass, phenotype, vascularization, receptor and afferent density…) and functional (flexor vs. extensor) differences between muscles could explain the amplitude of these responses.

  7. The neutron optical model potential

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1989-01-01

    The present status of optical model calculations of neutron scattering and interactions is reviewed, with special emphasis on more recent developments and the more promising lines of research. The use of dispersion relations to provide an extra constraint on the potential is discussed, together with their application to studies of the Fermi surface anomaly. The application of potential inversion techniques to determine the form of the potential is also considered. (author). 39 refs, figs

  8. Oxygen potentials of transuranium oxides

    International Nuclear Information System (INIS)

    Haruyoshi Otobe; Mituso Akabori; Arai Yasuo; Kazuo Minato

    2008-01-01

    The oxygen potentials of pyrochlore-type Pu 2 Zr 2 O 7+y , fluorite-type (Pu 0.5 Zr 0.5 )O 2-x and AmO 2-x have been measured by the electromotive force (EMF) method with a zirconia solid-electrolyte. The oxygen potentials of these oxides were reviewed. The phase relations, microstructure, equilibrium state of these oxides were discussed, referring to the isothermal curve of the oxygen potentials. (authors)

  9. Ambipolar potential formation in TMX

    International Nuclear Information System (INIS)

    Correl, D.L.; Allen, S.L.; Casper, T.A.

    1981-01-01

    TMX experimental data on ambipolar potential control and on the accompanying electrostatic confinement are reported. New results on the radial dependence of the central-cell confining potential are given. Radial and axial particle losses as well as scaling of the central-cell axial confinement are discussed

  10. The erosive potential of lollipops

    NARCIS (Netherlands)

    Brand, H.S.; Gambon, D.L.; Paap, A.; Bulthuis, M.S.; Veerman, E.C.I.; Nieuw Amerongen, A.V.

    2009-01-01

    Aim: To determine the erosive potential of several commercially available lollipops and the protective effect of saliva. Methods: The erosive potential of lollipops was determined in vitro by measuring the pH and neutralisable acidity. Subsequently, 10 healthy volunteers tested different types of

  11. Miscellaneous conditions and future potential

    International Nuclear Information System (INIS)

    Berquist, T.H.; Ehman, R.L.; Richardson, M.L.; Helms, C.A.

    1987-01-01

    The previous chapters have discussed basic principles and the types of musculoskeletal pathology that have been most extensively studied with magnetic resonance (MR) techniques. MR has also demonstrated significant potential in other areas, but experience is more limited. Despite this limited experience, the potential application of MR imaging in these areas is discussed in this paper

  12. Potential photosynthesis of crop surfaces.

    NARCIS (Netherlands)

    Wit, de C.T.

    1959-01-01

    A formula for calculating the potential photosynthesis of a closed crop surface is proposed, assuming that the leaves of the crop are not arranged in any definite direction. In the Netherlands, values for potential photosynthesis vary from 290 kg. CH2O/ha./day in June to 50 kg./ha./day in December.

  13. Supermodular Games and Potential Games

    NARCIS (Netherlands)

    Brânzei, R.; Mallozzi, L.; Tijs, S.H.

    2001-01-01

    Potential games and supermodular games are attractive games, especially because under certain conditions they possess pure Nash equilibria. Subclasses of games with a potential are considered which are also strategically equivalent to supermodular games. The focus is on two-person zero-sum games and

  14. Finite-Temperature Higgs Potentials

    International Nuclear Information System (INIS)

    Dolgopolov, M.V.; Gurskaya, A.V.; Rykova, E.N.

    2016-01-01

    In the present article we consider the short description of the “Finite-Temperature Higgs Potentials” program for calculating loop integrals at vanishing external momenta and applications for extended Higgs potentials reconstructions. Here we collect the analytic forms of the relevant loop integrals for our work in reconstruction of the effective Higgs potential parameters in extended models (MSSM, NMSSM and etc.)

  15. High-temperature axion potential

    International Nuclear Information System (INIS)

    Dowrick, N.J.; McDougall, N.A.

    1989-01-01

    We investigate the possibility of new terms in the high-temperature axion potential arising from the dynamical nature of the axion field and from higher-order corrections to the θ dependence in the free energy of the quark-gluon plasma. We find that the dynamical nature of the axion field does not affect the potential but that the higher-order effects lead to new terms in the potential which are larger than the term previously considered. However, neither the magnitude nor the sign of the potential can be calculated by a perturbative expansion of the free energy since the coupling is too large. We show that a change in the magnitude of the potential does not significantly affect the bound on the axion decay constant but that the sign of the potential is of crucial importance. By investigating the formal properties of the functional integral within the instanton dilute-gas approximation, we find that the sign of the potential does not change and that the minimum remains at θ=0. We conclude that the standard calculation of the axion energy today is not significantly modified by this investigation

  16. Cold atoms in singular potentials

    International Nuclear Information System (INIS)

    Denschlag, J. P.

    1998-09-01

    We studied both theoretically and experimentally the interaction between cold Li atoms from a magnetic-optical trap (MOT) and a charged or current-carrying wire. With this system, we were able to realize 1/r 2 and 1/r potentials in two dimensions and to observe the motion of cold atoms in both potentials. For an atom in an attractive 1/r 2 potential, there exist no stable trajectories, instead there is a characteristic class of trajectories for which atoms fall into the singularity. We were able to observe this falling of atoms into the center of the potential. Moreover, by probing the singular 1/r 2 potential with atomic clouds of varying size and temperature we extracted scaling properties of the atom-wire interaction. For very cold atoms, and very thin wires the motion of the atoms must be treated quantum mechanically. Here we predict that the absorption cross section for the 1/r 2 potential should exhibit quantum steps. These quantum steps are a manifestation of the quantum mechanical decomposition of plane waves into partial waves. For the second part of this work, we realized a two dimensional 1/r potential for cold atoms. If the potential is attractive, the atoms can be bound and follow Kepler-like orbits around the wire. The motion in the third dimension along the wire is free. We were able to exploit this property and constructed a novel cold atom guide, the 'Kepler guide'. We also demonstrated another type of atom guide (the 'side guide'), by combining the magnetic field of the wire with a homogeneous offset magnetic field. In this case, the atoms are held in a potential 'tube' on the side of the wire. The versatility, simplicity, and scaling properties of this guide make it an interesting technique. (author)

  17. Exceptional circles of radial potentials

    International Nuclear Information System (INIS)

    Music, M; Perry, P; Siltanen, S

    2013-01-01

    A nonlinear scattering transform is studied for the two-dimensional Schrödinger equation at zero energy with a radial potential. Explicit examples are presented, both theoretically and computationally, of potentials with nontrivial singularities in the scattering transform. The singularities arise from non-uniqueness of the complex geometric optics solutions that define the scattering transform. The values of the complex spectral parameter at which the singularities appear are called exceptional points. The singularity formation is closely related to the fact that potentials of conductivity type are ‘critical’ in the sense of Murata. (paper)

  18. Potential Theory Surveys and Problems

    CERN Document Server

    Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří

    1988-01-01

    The volume comprises eleven survey papers based on survey lectures delivered at the Conference in Prague in July 1987, which covered various facets of potential theory, including its applications in other areas. The survey papers deal with both classical and abstract potential theory and its relations to partial differential equations, stochastic processes and other branches such as numerical analysis and topology. A collection of problems from potential theory, compiled on the occasion of the conference, is included, with additional commentaries, in the second part of this volume.

  19. Chemical potentials in gauge theories

    International Nuclear Information System (INIS)

    Actor, A.; Pennsylvania State Univ., Fogelsville

    1985-01-01

    One-loop calculations of the thermodynamic potential Ω are presented for temperature gauge and non-gauge theories. Prototypical formulae are derived which give Ω as a function of both (i) boson and/or fermion chemical potential, and in the case of gauge theories (ii) the thermal vacuum parameter Asub(O)=const (Asub(μ) is the euclidean gauge potential). From these basic abelian gauge theory formulae, the one-loop contribution to Ω can readily be constructed for Yang-Mills theories, and also for non-gauge theories. (orig.)

  20. The nucleon-nucleon potential

    International Nuclear Information System (INIS)

    Green, A.M.

    1978-01-01

    The first part of this talk is based on the one presented at the Tokyo conference last September and can be found in ref( 1 ). This coveres such topics as the Paris and Stonybrook potentials, the new values of the NN coupling constants and also our understanding of the NNω coupling constant. The second part reviews recent developments concerning the Paris potential, the application of the MIT bag model to the NN interaction, the effect of crossed pion processes and vertex form factors. Comments made about the possible future trends of NN potential calculations. The current status of the D-state probability of the deuteron is discussed. (orig./AH) [de

  1. Potential Theory of Multicomponent Adsorption

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1998-01-01

    We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... and high degree of predictability of the theory developed....... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

  2. The deuteron microscopic optical potential

    International Nuclear Information System (INIS)

    Lu Congshan; Zhang Jingshang; Shen Qingbiao

    1991-01-01

    The two particle Green's function is introduced. When the direct interaction between two nucleons is neglected, the first and second order mass operators of two particles are the sum of those for each particle. The nucleon microscopic optical potential is calculated by applying nuclear matter approximation and effective Skyrme interaction. Then the deuteron microscopic optical potential (DMOP) is calculated by using fold formula. For improvement of the theory, the two particle polarization diagram contribution to the imaginary part of the deuteron microscopic optical potential is studied

  3. Quark potential of spontaneous strings

    International Nuclear Information System (INIS)

    German, G.; Kleinert, H.

    1989-01-01

    The authors present some recent developments in string models with an extrinsic curvature term in action. Particular emphasis is placed upon the static quark potential and on the thermal deconfinement properties of spontaneous strings

  4. Singular potentials in quantum mechanics

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Koo, E. Ley

    1995-10-01

    This paper is a review of some mathematical methods as recently developed and applied to deal with singular potentials in Quantum Mechanics. Regular and singular perturbative methods as well as variational treatments are considered. (author). 25 refs

  5. Potential Leaders and Democratic Values

    Science.gov (United States)

    Monsma, Stephen V.

    1971-01-01

    Indicates that potential contenders for public office are likely to be more knowledgeable, interested, and libertarian than the average citizen. Concludes that these differences exist before leaders are elected and that this discrimination is functional in a democracy. (MB)

  6. Molecular potentials and relaxation dynamics

    International Nuclear Information System (INIS)

    Karo, A.M.

    1981-01-01

    The use of empirical pseudopotentials, in evaluating interatomic potentials, provides an inexpensive and convenient method for obtaining highly accurate potential curves and permits the modeling of core-valence correlation, and the inclusion of relativistic effects when these are significant. As an example, recent calculations of the chi 1 Σ + and a 3 Σ + states of LiH, NaH, KH, RbH, and CsH and the chi 2 Σ + states of their anions are discussed. Pseudopotentials, including core polarization terms, have been used to replace the core electrons, and this has been coupled with the development of compact, highly-optimized basis sets for the corresponding one- and two-electron atoms. Comparisons of the neutral potential curves with experiment and other ab initio calculations show good agreement (within 1000 cm -1 over most of the potential curves) with the difference curves being considerably more accurate

  7. ANTAGONISTIC POTENTIAL OF FLUORESCENT Pseudomonas ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    GROWTH OF TOMATO CHALLENGED WITH PHTOPATHOGENS ... This study focused on the antagonistic potential of fluorescent Pseudomonas in vitro, and its inoculation effect on growth .... the 5 days old culture in starch agar with Lugol's.

  8. Potential measurements in tandem mirrors

    International Nuclear Information System (INIS)

    Glowienka, J.C.

    1985-11-01

    The US mirror program has begun conducting experiments with a thermal barrier tandem mirror configuration. This configuration requires a specific axial potential profile and implies measurements of potential for documentation and optimization of the configuration. This report briefly outlines the motivation for the thermal barrier tandem mirror and then outlines the techniques used to document the potential profile in conventional and thermal barrier tandem mirrors. Examples of typical data sets from the world's major tandem mirror experiments, TMX and TMX-U at Lawrence Livermore National Laboratory (LLNL) and Gamma 10 at Tsukuba University in Japan, and the current interpretation of the data are discussed together with plans for the future improvement of measurements of plasma potential

  9. Towards a commercially potential process

    DEFF Research Database (Denmark)

    Panpipat, Worawan; Xu, Xuebing; Guo, Zheng

    2012-01-01

    In order to examine the industrial potential to indirectly isolate phytosterols from deodoriser distillates (DODs), enzymatic transesterification of an industrial rapeseed and soybean oil DOD mixture with bioethanol was investigated using commercial lipases and a few newly immobilised preparations...

  10. Effective potentials for twisted fields

    International Nuclear Information System (INIS)

    Banach, R.

    1981-01-01

    Minus the density of the effective action, evaluated at the lowest eigenfunction of the (space-time) derivative part of the second (functional) derivative of the classical action, is proposed as a generalised definition of the effective potential, applicable to twisted as well as untwisted sectors of a field theory. The proposal is corroborated by several specific calculations in the twisted sector, namely phi 4 theory (real and complex) and wrong-sign-Gordon theory, in an Einstein cylinder, where the exact integrability of the static solutions confirms the effective potential predictions. Both models exhibit a phase transition, which the effective potential locates, and the one-loop quantum shift in the critical radius is computed for the real phi 4 model, being a universal result. Topological mass generation at the classical level is pointed out, and the exactness of the classical effective potential approximation for complex phi 4 is discussed. (author)

  11. Perihelium shifts in central potentials

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Ferreira, P.L.

    1987-01-01

    Motivated by the rigorous results on level ordering for arbitrary central potentials recently derived in the literature a classical treatment of the perihelium shifts is presented, based on the consideration of those orbits which lie in the vicinity of a circular orbit. The role played by the Laplacian of the potential is emphasized. By the same approach Bertrand's theorem is also discussed, in connection with Arnold's proof. (Author) [pt

  12. Static quark-antiquark potential

    International Nuclear Information System (INIS)

    Deo, B.B.; Barik, B.K.

    1983-01-01

    A heavy-quark--antiquark potential is suggested which connects asymptotic freedom and quark confinement in a unified manner by formal methods of field theory using some plausible assumptions. The potential has only one additional adjustable parameter B which is proportional to (M/sub q//m/sub q/), where M/sub q/ and m/sub q/ are the constituent and current quark masses, respectively

  13. Molecular potentials and relaxation dynamics

    International Nuclear Information System (INIS)

    Karo, A.M.

    1981-01-01

    The use of empirical pseudopotentials, in evaluating interatomic potentials, provides an inexpensive and convenient method for obtaining highly accurate potential curves and permits the modeling of core-valence correlation, and the inclusion of relativistic effects when these are significant. Recent calculations of the X 1 Σ + and a 3 Σ + states of LiH, NaH, KH, RbH, and CsH and the X 2 Σ + states of their anions are discussed. Pseudopotentials, including core polarization terms, have been used to replace the core electrons, and this has been coupled with the development of compact, higly-optimized basis sets for the corresponding one- and two-electron atoms. Comparisons of the neutral potential curves with experiment and other ab initio calculations show good agreement (within 1000 cm -1 over most of the potential curves) with the difference curves being considerably more accurate. In the method of computer molecular dynamics, the force acting on each particle is the resultant of all interactions with other atoms in the neighborhood and is obtained as the derivative of an effective many-body potential. Exploiting the pseudopotential approach, in obtaining the appropriate potentials may be very fruitful in the future. In the molecular dynamics example considered here, the conventional sum-of-pairwise-interatomic-potentials (SPP) approximation is used with the potentials derived either from experimental spectroscopic data or from Hartree-Fock calculations. The problem is the collisional de-excitation of vibrationally excited molecular hydrogen at an Fe surface. The calculations have been carried out for an initial vibrotational state v = 8, J = 1 and a translational temperature corresponding to a gas temperature of 500 0 K. Different angles of approach and different initial random impact points on the surface have been selected. For any given collision with the wall, the molecule may pick up or lose vibrotatonal and translational energy

  14. Deuteron microscopic optical model potential

    International Nuclear Information System (INIS)

    Guo Hairui; Han Yinlu; Shen Qingbiao; Xu Yongli

    2010-01-01

    A deuteron microscopic optical model potential is obtained by the Green function method through nuclear-matter approximation and local-density approximation based on the effective Skyrme interaction. The microscopic optical model potential is used to calculate the deuteron reaction cross sections and the elastic scattering angular distributions for some target nuclei in the mass range 6≤A≤208 with incident deuteron energies up to 200 MeV. The calculated results are compared with the experimental data.

  15. Potential scattering of Dirac particles

    International Nuclear Information System (INIS)

    Thaller, B.

    1981-01-01

    A quantum mechanical interpretation of the Dirac equation for particles in external electromagnetic potentials is discussed. It is shown that a consequent development of the Stueckelberg-Feynman theory into a probabilistic interpretation of the Dirac equation corrects some prejudices concerning negative energy states, Zitterbewegung and bound states in repulsive potentials and yields the connection between propagator theory and scattering theory. Limits of the Dirac equation, considered as a wave mechanical equation, are considered. (U.K.)

  16. STUDENTS’ POTENTIAL FOR AUTHENTIC LEADERSHIP

    OpenAIRE

    Djurdja Solesa-Grijak; Dragan Solesa; Nedjo Kojic

    2015-01-01

    To know yourself and to act accordingly has been seen as a moral imperative throughout history. The aim of this research was to determine potential of students for authentic leadership and relation between their authentic personality and potential for authentic leadership. The sample consisted of students (N=133) from Serbia (male – 59% and female – 41%). The average age of students was M=21.9. Instruments used were Authenticity Scale (Wood et al., 2008) and Authentic Leadership Self-Assessme...

  17. Estimation of potential uranium resources

    International Nuclear Information System (INIS)

    Curry, D.L.

    1977-09-01

    Potential estimates, like reserves, are limited by the information on hand at the time and are not intended to indicate the ultimate resources. Potential estimates are based on geologic judgement, so their reliability is dependent on the quality and extent of geologic knowledge. Reliability differs for each of the three potential resource classes. It is greatest for probable potential resources because of the greater knowledge base resulting from the advanced stage of exploration and development in established producing districts where most of the resources in this class are located. Reliability is least for speculative potential resources because no significant deposits are known, and favorability is inferred from limited geologic data. Estimates of potential resources are revised as new geologic concepts are postulated, as new types of uranium ore bodies are discovered, and as improved geophysical and geochemical techniques are developed and applied. Advances in technology that permit the exploitation of deep or low-grade deposits, or the processing of ores of previously uneconomic metallurgical types, also will affect the estimates

  18. Vicious walkers in a potential

    International Nuclear Information System (INIS)

    Bray, Alan J; Winkler, Karen

    2004-01-01

    We consider N vicious walkers moving in one dimension in a one-body potential v(x). Using the backward Fokker-Planck equation we derive exact results for the asymptotic form of the survival probability Q(x, t) of vicious walkers initially located at (x 1 , ..., x N ) = x, when v(x) is an arbitrary attractive potential. Explicit results are given for a square-well potential with absorbing or reflecting boundary conditions at the walls, and for a harmonic potential with an absorbing or reflecting boundary at the origin and the walkers starting on the positive half line. By mapping the problem of N vicious walkers in zero potential onto the harmonic potential problem, we rederive the results by Fisher (1984 J. Stat. Phys. 34 667) and Krattenthaler et al (2000 J. Phys. A: Math. Gen. 33 8835) respectively for vicious walkers on an infinite line and on a semi-infinite line with an absorbing wall at the origin. This mapping also gives a new result for vicious walkers on a semi-infinite line with a reflecting boundary at the origin: Q(x,t) ∼ t N(N-1)/2

  19. Economic potential of inertial fusion

    International Nuclear Information System (INIS)

    Nuckolls, J.H.

    1984-04-01

    Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents

  20. Labor potential: enhancing its development

    Directory of Open Access Journals (Sweden)

    O.P. Melnichuk

    2016-06-01

    Full Text Available This publication presents the views of the author about the need to expand research of labor potential, estimation of quantitative indicators and qualitative characteristics at the individual, regional levels and the state as a whole to develop the mechanisms of its development. The existing methods of labour potential assessment are mainly based on the probable approach taking into account external and internal factors. In the case of assessment of labour potential of a single enterprise for the most suitable for this production method the mechanisms of its development can be worked out. However, for the state under a certain depreciation of the resource, property, financial and other potentials, aggressive manifestations of the crisis phenomena, processes etc. to resolve urgent is the problem of enhancing the development of qualitative characteristics of labor potential at all its levels. In this context it is important to exploit the potential of domestic education and science which now continue to be reformed for the sake of achieving European standards, using the advanced experience of other countries. Every means of legal, financial, managerial, and organizational impact should be used for this.

  1. Streaming potential measurements of biosurfaces

    Science.gov (United States)

    Van Wagenen, R. A.; Andrade, J. D.; Hibbs, J. B., Jr.

    1976-01-01

    A technique based on the measurement of streaming potentials has been developed to evaluate the electrokinetic region of the cell periphery. This approach is feasible for cell lines propagated in in-vitro cell cultures in monolayer form. The advantage of this system is that cells may be evaluated in the living state atttached to a substrate; it is not necessary to subject the cells to enzymatic, chemical, or mechanical trauma required to obtain monodisperse suspensions which are then normally evaluated by microelectrophoresis. In this manner, it should be possible to study the influence of substrate and environmental factors on the charge density and potential at the cell periphery. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of borosilicate capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming-potential measurements is discussed. The electrokinetic potential of BALB/c 3T12 fibroblasts has been quantified as a function of pH, ionic strength, glutaraldehyde fixation, and Giemsa staining.

  2. A semiclassical study of optical potentials - potential resonances -

    International Nuclear Information System (INIS)

    Lee, S.Y.; Takigawa, N.; Marty, C.

    1977-01-01

    A semiclassical method is used to analyze resonances produced by complex potentials. The absorption plays a central role: when it is not too great, resonances manifest themselves by enhancement of cross sections near π. The reverse is not necessarily true, for instance the anomalous large angle scattering for α-Ca is due to a coherent superposition of many partial waves

  3. Neutron and proton optical potentials

    International Nuclear Information System (INIS)

    Hansen, L.F.

    1985-11-01

    The neutron and proton optical model potentials (OMP) are discussed in terms of microscopic (MOMP) and phenomenological (POMP) models. For the MOMP, two approaches are discussed, the nucleus matter approach [Jeukenne-Lejeune-Mahaux (JLM) and Brieva-Rook-von Geramb (BRVG), potentials] and the finite nuclei approach (Osterfeld and Madsen). For the POMP, the Lane charge-exchange potential and its validity over a wide mass range is reviewed. In addition to the Lane symmetry term, the Coulomb correction to both the real and imaginary parts of the OMP is discussed for the above models. The use of the OMP to calculate collective inelastic scattering and observed differences between the neutron- and proton-deformation parameters is also illustrated. 25 refs., 3 figs

  4. Wind energy potential in Bulgaria

    International Nuclear Information System (INIS)

    Shtrakov, Stanko Vl.

    2009-01-01

    In this study, wind characteristic and wind energy potential in Bulgaria were analyzed using the wind speed data. The wind energy potential at different sites in Bulgaria has been investigated by compiling data from different sources and analyzing it using a software tool. The wind speed distribution curves were obtained by using the Weibull and Rayleigh probability density functions. The results relating to wind energy potential are given in terms of the monthly average wind speed, wind speed probability density function (PDF), wind speed cumulative density function (CDF), and wind speed duration curve. A technical and economic assessment has been made of electricity generation from three wind turbines having capacity of (60, 200, and 500 kW). The yearly energy output capacity factor and the electrical energy cost of kWh produced by the three different turbines were calculated

  5. Accelerating cosmologies from exponential potentials

    International Nuclear Information System (INIS)

    Neupane, Ishwaree P.

    2003-11-01

    It is learnt that exponential potentials of the form V ∼ exp(-2cφ/M p ) arising from the hyperbolic or flux compactification of higher-dimensional theories are of interest for getting short periods of accelerated cosmological expansions. Using a similar potential but derived for the combined case of hyperbolic-flux compactification, we study a four-dimensional flat (or open) FRW cosmologies and give analytic (and numerical) solutions with exponential behavior of scale factors. We show that, for the M-theory motivated potentials, the cosmic acceleration of the universe can be eternal if the spatial curvature of the 4d spacetime is negative, while the acceleration is only transient for a spatially flat universe. We also briefly discuss about the mass of massive Kaluza-Klein modes and the dynamical stabilization of the compact hyperbolic extra dimensions. (author)

  6. Introduction to heat potential theory

    CERN Document Server

    Watson, Neil A

    2012-01-01

    This book is the first to be devoted entirely to the potential theory of the heat equation, and thus deals with time dependent potential theory. Its purpose is to give a logical, mathematically precise introduction to a subject where previously many proofs were not written in detail, due to their similarity with those of the potential theory of Laplace's equation. The approach to subtemperatures is a recent one, based on the Poisson integral representation of temperatures on a circular cylinder. Characterizations of subtemperatures in terms of heat balls and modified heat balls are proved, and thermal capacity is studied in detail. The generalized Dirichlet problem on arbitrary open sets is given a treatment that reflects its distinctive nature for an equation of parabolic type. Also included is some new material on caloric measure for arbitrary open sets. Each chapter concludes with bibliographical notes and open questions. The reader should have a good background in the calculus of functions of several vari...

  7. Potential Theory of Multicomponent Adsorption

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1998-01-01

    We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... parameters, is used for the segregated and for the bulk phases. With this approach, few parameters are needed to correlate pure component adsorption isotherms. These parameters may be used to predict adsorption equilibria of multicomponent mixtures without additional adjustment. A connection between...... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

  8. The potential of biogas energy

    International Nuclear Information System (INIS)

    Acaroglu, M.; Hepbasli, A.; Kocar, G.

    2005-01-01

    Biogas technology has been known about for a long time, but in recent years the interest in it has significantly increased, especially due to the higher costs and the rapid depletion of fossil fuels as well as their environmental considerations. The main objective of the present study is to investigate the potential of biogas energy in the 15 European Union (EU) countries and in Turkey, which is seeking admission to the EU and is trying to meet EU environmental standards. Biogas energy potential of the 15 EU countries is estimated to be about 800 PJ. Besides this, Turkey's annual animal waste potential is obtained to be about 11.81 million tons with a biogas energy equivalent of 53.6 PJ. It is expected that this study will be helpful in developing highly applicable and productive planning for energy policies towards the optimum utilization of biogas energy. (author)

  9. Handbook methane potential; Handbok metanpotential

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, My (AnoxKaldnes AB (Sweden)); Schnurer, Anna (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    2011-07-15

    Before using a organic material for biogas production it is essential to evaluate the methane production potential. The methane potential is one important tool possible to use during planning of new plants but also when new materials are considered for already running biogas plants. The chemical composition of different organic material varies extensively and this will have an impact on both the degradability and the methane potential. Information about the methane potential of a specific material can sometimes be found in the literature or can be calculated after a chemical/ physical or biological characterization. Here, the BMP test (Biochemical Methane Potential) is a commonly used method. Today the BMP test is a commonly used method to determine the methane potential. Many national and international research groups, consultants as well as personal at biogas plants are using this method and there is a lot of data available in the literature from such tests. In addition there are several protocols giving guidelines on how to execute a BMP-test. The BMP-test is performed in many different ways, not always under optimized conditions, and there is a lack of information on how to interpret the obtained data. This report summarizes knowledge from the literature and the experience from a Swedish referee group, consisting of persons being active performers of BMP-tests. The report does not include a standardized protocol as the procedure can be performed in different ways depending on available equipment and on the type of material to be tested. Instead the report discusses different factors of great importance for a successful test giving reliable results. The report also summarizes important information concerning the interpretation and how to present results in order to allow comparison of data from different test.

  10. Potential problems with interpolating fields

    Energy Technology Data Exchange (ETDEWEB)

    Birse, Michael C. [The University of Manchester, Theoretical Physics Division, School of Physics and Astronomy, Manchester (United Kingdom)

    2017-11-15

    A potential can have features that do not reflect the dynamics of the system it describes but rather arise from the choice of interpolating fields used to define it. This is illustrated using a toy model of scattering with two coupled channels. A Bethe-Salpeter amplitude is constructed which is a mixture of the waves in the two channels. The potential derived from this has a strong repulsive core, which arises from the admixture of the closed channel in the wave function and not from the dynamics of the model. (orig.)

  11. Tunnel superpenetrability of potential barriers

    International Nuclear Information System (INIS)

    Zakhariev, B N.

    1982-01-01

    The transmission of two particles through the same barrier is considered. The limiting cases are compared when the particles are joined together in a single particle with double mass-energy and potential and when they pass the barrier independently. As an intermediate case a pair of particles bound in a quasideuteron of a finite size is considered. It is shown that long-range collective correlations of particles (of the superfluidity type and others) simplify very much for them passing through high potential barriers. This happens due to the transfer of the additional energy from the particles outside the barriers to those inside it

  12. Potential Applications of Manual Games,

    Science.gov (United States)

    1984-02-01

    34 just because some electronic equipment is used to keep track of logistics, combat results, and force status. Even a highly computerized game like...D-A152 541 POTENTIAL APPLICATIONS OF MANUAL GAMES (U) RAND CORP ii SANTA MONICA CA T A BROW~N FEB 84 RAND/P-6957 UNCLASI7FIED F/G 12/2 N El..I 111 1...128 112.5 111 m; * _ 1.8 I1111 ’I’ll MICROCOPY RESOLUTION TEST CHART NATI NAl fii~ t1 RI 1A L4k, I POTENTIAL APPLICATIONS OF MANUJAL GAMES Lfl N Lfl

  13. Diatomic interaction potential theory applications

    CERN Document Server

    Goodisman, Jerry

    2013-01-01

    Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des

  14. Effective potential models for hadrons

    International Nuclear Information System (INIS)

    Lucha, W.

    1995-12-01

    The aim of these lectures is to give a self-contained introduction to nonrelativistic potential models, to their formulation as well as to their possible applications. At the price of some lack of (in a mathematical sense) rigorous derivations, we try to give a feeling and understanding for the simplest conceivable method to extract the explicit form of the forces acting between quarks from the interplay between experimental observations and theoretical considerations. According to this spirit, we demonstrate, in detail, how to obtain the underlying Hamiltonian and how to determine the Lorentz structure of the quark-(anti-)quark interaction potential from well-established experimental facts. (author)

  15. Global warming potential of pavements

    Energy Technology Data Exchange (ETDEWEB)

    Santero, Nicholas J [Department of Civil and Environmental Engineering, 407 McLaughlin Hall, University of California, Berkeley, CA 94720-1712 (United States); Horvath, Arpad, E-mail: njsantero@cal.berkeley.ed, E-mail: horvath@ce.berkeley.ed [Department of Civil and Environmental Engineering, 215B McLaughlin Hall, University of California, Berkeley, CA 94720-1712 (United States)

    2009-09-15

    Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.

  16. Global warming potential of pavements

    International Nuclear Information System (INIS)

    Santero, Nicholas J; Horvath, Arpad

    2009-01-01

    Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.

  17. Exponential Potential versus Dark Matter

    Science.gov (United States)

    1993-10-15

    scale of the solar system. Galaxy, Dark matter , Galaxy cluster, Gravitation, Quantum gravity...A two parameter exponential potential explains the anomalous kinematics of galaxies and galaxy clusters without need for the myriad ad hoc dark ... matter models currently in vogue. It also explains much about the scales and structures of galaxies and galaxy clusters while being quite negligible on the

  18. Riesz potential versus fractional Laplacian

    KAUST Repository

    Ortigueira, Manuel Duarte

    2014-09-01

    This paper starts by introducing the Grünwald-Letnikov derivative, the Riesz potential and the problem of generalizing the Laplacian. Based on these ideas, the generalizations of the Laplacian for 1D and 2D cases are studied. It is presented as a fractional version of the Cauchy-Riemann conditions and, finally, it is discussed with the n-dimensional Laplacian.

  19. Assessment of triton potential energy

    International Nuclear Information System (INIS)

    Friar, J.L.; Payne, G.L.

    1995-01-01

    An assessment is made of the dominant features contributing to the triton potential energy, with the objective of understanding qualitatively their origins and sensitivities. Relativistic effects, short-range repulsion, and OPEP dominance are discussed. A determination of the importance of various regions of nucleon-nucleon separation is made numerically. (author)

  20. Sports Potentials for Physical Fitness.

    Science.gov (United States)

    Clarke, H. Harrison, Ed.

    1978-01-01

    This report, one of a series on research into specific physical activities and their efficacy in improving and maintaining physical fitness, examines sport participation and the potential it has for developing muscular strength, muscular endurance, and circulatory-respiratory endurance. The activities consist primarily of the following twelve…

  1. Evolutionary potential games on lattices

    International Nuclear Information System (INIS)

    Szabó, György; Borsos, István

    2016-01-01

    Game theory provides a general mathematical background to study the effect of pair interactions and evolutionary rules on the macroscopic behavior of multi-player games where players with a finite number of strategies may represent a wide scale of biological objects, human individuals, or even their associations. In these systems the interactions are characterized by matrices that can be decomposed into elementary matrices (games) and classified into four types. The concept of decomposition helps the identification of potential games and also the evaluation of the potential that plays a crucial role in the determination of the preferred Nash equilibrium, and defines the Boltzmann distribution towards which these systems evolve for suitable types of dynamical rules. This survey draws parallel between the potential games and the kinetic Ising type models which are investigated for a wide scale of connectivity structures. We discuss briefly the applicability of the tools and concepts of statistical physics and thermodynamics. Additionally the general features of ordering phenomena, phase transitions and slow relaxations are outlined and applied to evolutionary games. The discussion extends to games with three or more strategies. Finally we discuss what happens when the system is weakly driven out of the “equilibrium state” by adding non-potential components representing games of cyclic dominance.

  2. Being a potentially responsible party

    International Nuclear Information System (INIS)

    Ronan, J.T.

    1989-01-01

    This paper reports on CERCLA II- ability for the unlucky potentially responsible parties (PRPs) which is a Draconian form of strict, joint and several liability with limited statutory defenses that in most cases are impossible to establish. CERCLA vigorously employs these legal concepts, stretching a PRP's financial exposure to the limits necessary to meet the enormous financial costs of remediation

  3. High Potentials: A CEO Perspective

    Science.gov (United States)

    Hermans, Jeanine

    2007-01-01

    Finding high potentials has been identified as one of the major challenges for society and for higher education. But how does one find the talented individuals who will design the future of society? Can and should universities cooperate or compete with business and industry for these talents? Three CEOs reflect on this worldwide competition for…

  4. Evolutionary potential games on lattices

    Energy Technology Data Exchange (ETDEWEB)

    Szabó, György, E-mail: szabo@mfa.kfki.hu; Borsos, István, E-mail: borsos@mfa.kfki.hu

    2016-04-05

    Game theory provides a general mathematical background to study the effect of pair interactions and evolutionary rules on the macroscopic behavior of multi-player games where players with a finite number of strategies may represent a wide scale of biological objects, human individuals, or even their associations. In these systems the interactions are characterized by matrices that can be decomposed into elementary matrices (games) and classified into four types. The concept of decomposition helps the identification of potential games and also the evaluation of the potential that plays a crucial role in the determination of the preferred Nash equilibrium, and defines the Boltzmann distribution towards which these systems evolve for suitable types of dynamical rules. This survey draws parallel between the potential games and the kinetic Ising type models which are investigated for a wide scale of connectivity structures. We discuss briefly the applicability of the tools and concepts of statistical physics and thermodynamics. Additionally the general features of ordering phenomena, phase transitions and slow relaxations are outlined and applied to evolutionary games. The discussion extends to games with three or more strategies. Finally we discuss what happens when the system is weakly driven out of the “equilibrium state” by adding non-potential components representing games of cyclic dominance.

  5. Health Educational Potentials of Technologies.

    OpenAIRE

    Magnussen, Rikke; Aagaard-Hansen, Jens

    2012-01-01

    The field of health promotion technology has been in an exponential growth in recent years and smart phone applications, exer-games and self-monitoring devices has become part of fitness activities and health education. In this work-in-progress-paper theoretical perspectives for categorising and analysing health educational potentials of technologies are presented.

  6. Event horizon and scalar potential

    International Nuclear Information System (INIS)

    Duruisseau, J.P.; Tonnelat, M.A.

    1977-01-01

    The introduction of a scalar potential with a more general scheme than General Relativity eliminates the event horizon. Among possible solutions, the Schwarzschild one represents a singular case. A study of the geodesic properties of the matching with an approximated interior solution are given. A new definition of the gravitational mass and chi function is deduced. (author)

  7. Potential theory for directed networks.

    Directory of Open Access Journals (Sweden)

    Qian-Ming Zhang

    Full Text Available Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i We propose a new mechanism for the local organization of directed networks; (ii We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation.

  8. Determination of nominal accelerating potential

    International Nuclear Information System (INIS)

    Nizin, P.; Kase, K.

    1986-01-01

    We present a simple linear relationship between the nominal accelerating potential (NAP) and the ratios of ionization measurements made with constant source--detector distance and at two different phantom thicknesses. This relationship can be used as a standard, unambiguous method for determining NAP for use in dosimetry and quality control

  9. Evolutionary potential games on lattices

    Science.gov (United States)

    Szabó, György; Borsos, István

    2016-04-01

    Game theory provides a general mathematical background to study the effect of pair interactions and evolutionary rules on the macroscopic behavior of multi-player games where players with a finite number of strategies may represent a wide scale of biological objects, human individuals, or even their associations. In these systems the interactions are characterized by matrices that can be decomposed into elementary matrices (games) and classified into four types. The concept of decomposition helps the identification of potential games and also the evaluation of the potential that plays a crucial role in the determination of the preferred Nash equilibrium, and defines the Boltzmann distribution towards which these systems evolve for suitable types of dynamical rules. This survey draws parallel between the potential games and the kinetic Ising type models which are investigated for a wide scale of connectivity structures. We discuss briefly the applicability of the tools and concepts of statistical physics and thermodynamics. Additionally the general features of ordering phenomena, phase transitions and slow relaxations are outlined and applied to evolutionary games. The discussion extends to games with three or more strategies. Finally we discuss what happens when the system is weakly driven out of the "equilibrium state" by adding non-potential components representing games of cyclic dominance.

  10. Riesz potential versus fractional Laplacian

    KAUST Repository

    Ortigueira, Manuel Duarte; Laleg-Kirati, Taous-Meriem; Machado, José Antó nio Tenreiro

    2014-01-01

    This paper starts by introducing the Grünwald-Letnikov derivative, the Riesz potential and the problem of generalizing the Laplacian. Based on these ideas, the generalizations of the Laplacian for 1D and 2D cases are studied. It is presented as a fractional version of the Cauchy-Riemann conditions and, finally, it is discussed with the n-dimensional Laplacian.

  11. Tank farm potential ignition sources

    International Nuclear Information System (INIS)

    Scaief, C.C. III.

    1996-01-01

    This document identifies equipment, instrumentation, and sensors that are located in-tank as well as ex-tank in areas that may have communication paths with the tank vapor space. For each item, and attempt is made to identify the potential for ignition of flammable vapors using a graded approach. The scope includes all 177 underground storage tanks

  12. Wind energy potential in India

    International Nuclear Information System (INIS)

    Rangarajan, S.

    1995-01-01

    Though located in the tropics, India is endowed with substantial wind resources because of its unique geographical location which gets fully exposed to both the south-west and north-east monsoon winds. The westerly winds of the south-west monsoons provide bulk of the wind potential. Areas with mean annual wind speed exceeding 18 k mph and areas with mean annual power density greater than 140 W/m 2 have been identified using the wind data collected by the wind monitoring project funded by the Ministry of Non-conventional Energy Sources (MNES). Seasonal variations in wind speed at selected locations are discussed as also the frequency distribution of hourly wind speed. Annual capacity factors for 250 kW wind electric generators have been calculated for several typical locations. A good linear correlation has been found between mean annual wind speed and mean annual capacity factor. A method is described for assessing wind potential over an extended region where adequate data is available. It is shown that the combined wind energy potential over five selected areas of limited extent in Gujarat, Andhra Pradesh and Tamil Nadu alone amounts to 22,000 MW under the assumption of 20 per cent land availability for installing wind farms. For a higher percentage of land availability, the potential will be correspondingly higher. (author). 12 refs., 6 figs., 3 tabs

  13. Bitcoin's Potential for Going Mainstream

    NARCIS (Netherlands)

    Kasiyanto, Safari

    2016-01-01

    This paper reviews the possibility of bringing Bitcoin into the mainstream. In so doing, it elaborates the potential and obstacles of the Bitcoin system and what it would take for it to go mainstream. A cross-cutting discussion provides a helicopter view and encompasses the technical, economic,

  14. Potential Theory for Directed Networks

    Science.gov (United States)

    Zhang, Qian-Ming; Lü, Linyuan; Wang, Wen-Qiang; Zhou, Tao

    2013-01-01

    Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i) We propose a new mechanism for the local organization of directed networks; (ii) We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation. PMID:23408979

  15. Electromagnetic potentials without gauge transformations

    International Nuclear Information System (INIS)

    Chubykalo, A; Espinoza, A; Alvarado Flores, R

    2011-01-01

    In this paper, we show that the use of the Helmholtz theorem enables the derivation of uniquely determined electromagnetic potentials without the necessity of using gauge transformation. We show that the electromagnetic field comprises two components, one of which is characterized by instantaneous action at a distance, whereas the other propagates in retarded form with the velocity of light. In our attempt to show the superiority of the new proposed method to the standard one, we argue that the action-at-a-distance components cannot be considered as a drawback of our method, because the recommended procedure for eliminating the action at a distance in the Coulomb gauge leads to theoretical subtleties that allow us to say that the needed gauge transformation is not guaranteed. One of the theoretical consequences of this new definition is that, in addition to the electric E and magnetic B fields, the electromagnetic potentials are real physical quantities. We show that this property of the electromagnetic potentials in quantum mechanics is also a property of the electromagnetic potentials in classical electrodynamics.

  16. The hydrogeothermal potential of Southern Hesse; Das hydrogeothermische Potential Suedhessens

    Energy Technology Data Exchange (ETDEWEB)

    Fitzer, C; Fluhrer, S; Sanner, B; Knoblich, K [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften

    1997-12-01

    The paper investigates rock series suited as storage media and the temperature distribution in the subsurface of Southern Hesse. It gives an idea of the possibilities for hydrogeothermal energy use in the area. The densily populated Rhein-Main-region provides a good demand potential for geothermal heat. A substantially elevated geothermal gradient of about 60 K/km as compared to the continental average of 30 K/km could be demonstrated in the northern part of the Upper Rhine Graben. Thermal anomalies could be localised. The Rotliegend-layers (Perm) provide the highest geothermal ressources in the region. In more shallow depth, the Hydrobia layers (Teritary) show reasonable values. To the north, the potential of these series decreases. Hence hydrogeothermal energy use should not be considered in the northern part of Southern Hesse. The highest potential can be expected from the Rotliegend layers in the area of Stockstadt and Biebesheim. (orig.) [Deutsch] Die Untersuchung geht auf die moeglichen Speichergesteine und die Temperaturverteilung im Untergrund Suedhessens ein und gibt einen ersten Eindruck von den Moeglichkeiten zur Nutzung der Hydrogeothermie in der Region. Fuer geothermische Waerme besteht im dicht besiedelten Rhein-Main-Gebiet eine gute Abnehmerstruktur. Im noerdlichen Oberrheingraben konnte im Mittel ein deutlich erhoehter Temperaturgradient von etwa 60 K/km gegenueber dem kontinentalen Krustendurchschnittswert von 30 K/km nachgewiesen werden. Waemeanomalien wurden lokalisiert. Die Rotliegendschichten weisen im untersuchten Gebiet eindeutig die hoechsten Ressourcen auf. In geringerer Tiefenlage erzielen die Hydrobienschichten noch beachtliche Werte. Nach Norden nimmt das Potential der Schichten ab. Daher ist von einer Nutzung der Hydrogeothermie im noerdlichen Bereich Suedhessens eher abzuraten. Die hoechsten Ressourcen in Suedhessen sind im Bereich von Stockstadt und Biebesheim in den Rotliegenschichten zu erwarten. (orig.)

  17. Decoupling Action Potential Bias from Cortical Local Field Potentials

    Directory of Open Access Journals (Sweden)

    Stephen V. David

    2010-01-01

    Full Text Available Neurophysiologists have recently become interested in studying neuronal population activity through local field potential (LFP recordings during experiments that also record the activity of single neurons. This experimental approach differs from early LFP studies because it uses high impendence electrodes that can also isolate single neuron activity. A possible complication for such studies is that the synaptic potentials and action potentials of the small subset of isolated neurons may contribute disproportionately to the LFP signal, biasing activity in the larger nearby neuronal population to appear synchronous and cotuned with these neurons. To address this problem, we used linear filtering techniques to remove features correlated with spike events from LFP recordings. This filtering procedure can be applied for well-isolated single units or multiunit activity. We illustrate the effects of this correction in simulation and on spike data recorded from primary auditory cortex. We find that local spiking activity can explain a significant portion of LFP power at most recording sites and demonstrate that removing the spike-correlated component can affect measurements of auditory tuning of the LFP.

  18. On the dynamics of gauge potential

    International Nuclear Information System (INIS)

    Tao Jiafu; Li Yuanjie; Zhang Jinru

    1992-01-01

    The gauge potential is resolved into gauge potential of strength and gauge potential of phase. The phase gauge potential can be described with an equivalent potential of inertial force. A Lagrangian density with phase gauge potential is given and some examples are discussed. The method proposed has been extended to the case of the non-Abelian group

  19. The Biodiversity Informatics Potential Index

    Science.gov (United States)

    2011-01-01

    Background Biodiversity informatics is a relatively new discipline extending computer science in the context of biodiversity data, and its development to date has not been uniform throughout the world. Digitizing effort and capacity building are costly, and ways should be found to prioritize them rationally. The proposed 'Biodiversity Informatics Potential (BIP) Index' seeks to fulfill such a prioritization role. We propose that the potential for biodiversity informatics be assessed through three concepts: (a) the intrinsic biodiversity potential (the biological richness or ecological diversity) of a country; (b) the capacity of the country to generate biodiversity data records; and (c) the availability of technical infrastructure in a country for managing and publishing such records. Methods Broadly, the techniques used to construct the BIP Index were rank correlation, multiple regression analysis, principal components analysis and optimization by linear programming. We built the BIP Index by finding a parsimonious set of country-level human, economic and environmental variables that best predicted the availability of primary biodiversity data accessible through the Global Biodiversity Information Facility (GBIF) network, and constructing an optimized model with these variables. The model was then applied to all countries for which sufficient data existed, to obtain a score for each country. Countries were ranked according to that score. Results Many of the current GBIF participants ranked highly in the BIP Index, although some of them seemed not to have realized their biodiversity informatics potential. The BIP Index attributed low ranking to most non-participant countries; however, a few of them scored highly, suggesting that these would be high-return new participants if encouraged to contribute towards the GBIF mission of free and open access to biodiversity data. Conclusions The BIP Index could potentially help in (a) identifying countries most likely to

  20. Hemolytic potential of hydrodynamic cavitation.

    Science.gov (United States)

    Chambers, S D; Bartlett, R H; Ceccio, S L

    2000-08-01

    The purpose of this study was to determine the hemolytic potentials of discrete bubble cavitation and attached cavitation. To generate controlled cavitation events, a venturigeometry hydrodynamic device, called a Cavitation Susceptibility Meter (CSM), was constructed. A comparison between the hemolytic potential of discrete bubble cavitation and attached cavitation was investigated with a single-pass flow apparatus and a recirculating flow apparatus, both utilizing the CSM. An analytical model, based on spherical bubble dynamics, was developed for predicting the hemolysis caused by discrete bubble cavitation. Experimentally, discrete bubble cavitation did not correlate with a measurable increase in plasma-free hemoglobin (PFHb), as predicted by the analytical model. However, attached cavitation did result in significant PFHb generation. The rate of PFHb generation scaled inversely with the Cavitation number at a constant flow rate, suggesting that the size of the attached cavity was the dominant hemolytic factor.

  1. Potential therapeutic applications of biosurfactants.

    Science.gov (United States)

    Gudiña, Eduardo J; Rangarajan, Vivek; Sen, Ramkrishna; Rodrigues, Lígia R

    2013-12-01

    Biosurfactants have recently emerged as promising molecules for their structural novelty, versatility, and diverse properties that are potentially useful for many therapeutic applications. Mainly due to their surface activity, these molecules interact with cell membranes of several organisms and/or with the surrounding environments, and thus can be viewed as potential cancer therapeutics or as constituents of drug delivery systems. Some types of microbial surfactants, such as lipopeptides and glycolipids, have been shown to selectively inhibit the proliferation of cancer cells and to disrupt cell membranes causing their lysis through apoptosis pathways. Moreover, biosurfactants as drug delivery vehicles offer commercially attractive and scientifically novel applications. This review covers the current state-of-the-art in biosurfactant research for therapeutic purposes, providing new directions towards the discovery and development of molecules with novel structures and diverse functions for advanced applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. In plant corrosion potential monitoring

    International Nuclear Information System (INIS)

    Rosborg, B.; Molander, A.

    1997-01-01

    Examples of in plant redox and corrosion potential monitoring in light water reactors are given. All examples are from reactors in Sweden. The measurements have either been performed in side-stream autoclaves connected to the reactor systems by sampling lines, or in-situ in the system piping itself. Potential monitoring can give quite different results depending upon the experimental method. For environments with small concentrations of oxidants sampling lines can introduce large errors. During such circumstances in-situ measurements are necessary. Electrochemical monitoring is a valuable technique as a complement to conventional water chemistry follow-up in plants. It can be used for water chemistry surveillance and can reveal unintentional and harmful water chemistry transients. (author). 15 figs

  3. Kleptomania and Potential Exacerbating Factors

    Science.gov (United States)

    2011-01-01

    Kleptomania is an impulse control disorder that can cause significant impairment and serious consequences. Often, the condition is kept secret by the patient, and usually help is sought only when confronted by the legal consequences of the impulsive behaviors. Historically, kleptomania has been viewed from a psychodynamic perspective, and the mainstay of treatment has been psychotherapy. Recently, attempts to explain kleptomania within a neuropsychiatric paradigm have highlighted the possible links between mood disorders, addictive behaviors, and brain injury with kleptomania. These associations with kleptomania can be extrapolated to pharmacological strategies that can potentially help in treating kleptomania. A case of kleptomania, which was potentially exacerbated by multiple factors, will be reviewed. Treatment modalities used in this case, including the use of the Yale-Brown Obsessive Compulsive Scale as a surrogate marker to gauge response to treatment, will be discussed. PMID:22132369

  4. Metasynthesis findings: potential versus reality.

    Science.gov (United States)

    Finfgeld-Connett, Deborah

    2014-11-01

    Early on, qualitative researchers predicted that metasynthesis research had the potential to significantly push knowledge development forward. More recently, scholars have questioned whether this is actually occurring. To examine this concern, a randomly selected sample of metasynthesis articles was systematically reviewed to identify the types of findings that have been produced. Based on this systematic examination, it appears that findings from metasynthesis investigations might not be reaching their full potential. Metasynthesis investigations frequently result in isolated findings rather than findings in relationship, and opportunities to generate research hypotheses and theoretical models are not always fully realized. With this in mind, methods for moving metasynthesis findings into relationship are discussed. © The Author(s) 2014.

  5. The potential of wind farms

    International Nuclear Information System (INIS)

    Hauge Madsen, P.; Lundsager, P.

    1992-09-01

    Papers presented at the European wind energy conference on the potential of wind farms are presented. The aim of the conference was to bring into focus the problems, experiences and potential of the application of wind power in wind power farms as a contribution to the European and global energy supply. It was considered that the interchange of experience among representatives of science, utilities, industry, environment and energy planning, together with those who represent financial and insurance interests, would create a better understanding of all aspects of wind power for its future successful development. The subjects covered concern surveys of national planning and policies regarding wind energy utilization and national and global development of wind turbine arrays. The performance of some individual wind farms is described. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigues, wakes, noise and control. (AB)

  6. In plant corrosion potential monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, B; Molander, A [Studsvik Material AB, Nykoeping (Sweden)

    1997-02-01

    Examples of in plant redox and corrosion potential monitoring in light water reactors are given. All examples are from reactors in Sweden. The measurements have either been performed in side-stream autoclaves connected to the reactor systems by sampling lines, or in-situ in the system piping itself. Potential monitoring can give quite different results depending upon the experimental method. For environments with small concentrations of oxidants sampling lines can introduce large errors. During such circumstances in-situ measurements are necessary. Electrochemical monitoring is a valuable technique as a complement to conventional water chemistry follow-up in plants. It can be used for water chemistry surveillance and can reveal unintentional and harmful water chemistry transients. (author). 15 figs.

  7. The potential of wind farms

    International Nuclear Information System (INIS)

    Hauge Madsen, P.; Lundsager, P.

    1992-09-01

    Papers presented at the European wind energy conference on the potential of wind farms are presented. The aim of the conference was to bring into focus the problems, experiences and potential of the application of wind power in wind power farms as a contribution to the European and global energy supply. It was considered that the interchange of experience among representatives of science, utilities, industry, environment and energy planning, together with those who represent financial and insurance interests, would create a better understanding of all aspects of wind power for its future successful development. The subjects covered concern surveys of national planning and policies regarding wind energy utilization and national and global development of wind turbine arrays. The performance of some individual wind farms is described. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigus, wakes, noise and control. (AB)

  8. Virtual materiality, potentiality and subjctivity

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    2013-01-01

    , of movies and of dreams as they enter intra-activities in the comprehensive set of apparatuses that enact child agency, subjectivity and relational practices. The analyses and conceptual refinements are based on empirical cases involving interviews with and observations among 8-14 year old children.......How do we conceptualize virtual materiality, in terms of for instance avatars and weapons in computer games, virtual discourse and subjectivity as phenomena intra-acting with real life materiality, discourse and subjectivity in children’s everyday lives? How do we understand the intra......-activity of such elements in children’s night dreams? These are some of the questions discussed in this text. I bring together Karen Barad’s agential realism and Giorgi Agamben’s concept of potentiality to enable and refine an analytical approach to real-virtual enactments, thereby questioning the potentialities of gaming...

  9. Crystal potential retrieval in HRTEM

    International Nuclear Information System (INIS)

    Beeching, M.J.; Spargo, A.E.C.

    1993-01-01

    A possible method for obtaining the crystal potential by inversion of the complex wavefield at the exit surface of the specimen, based on reversal of the multi-slice algorithm, is outlined. Results from preliminary testing of the method using computer simulated data are presented and appear promising, although the limits of applicability of the method are yet to be defined. 13 refs., 5 figs

  10. ADVERGAMES: CHARACTERISTICS, LIMITATIONS AND POTENTIAL

    Directory of Open Access Journals (Sweden)

    Gurau Calin

    2010-07-01

    Full Text Available Advergames represent a new advertising concept that uses Internet technology to implement viral marketing campaigns. Despite the potential of this interactive advertising method, very few academic studies have been initiated to investigate the characteristics of advergames, and their influence on consumers’ perceptions and behaviour. Using secondary data, this paper attempts to evaluate the characteristics of effective advergames, and to analyse the effect of advergames on players’ perceptions and behaviour.

  11. Potentials in N=2 supergravity

    International Nuclear Information System (INIS)

    Zinov'ev, Yu.M.

    1985-01-01

    The potentials and Yukava interactions, that arise while introducing a gauge interaction of vector and scalar multiplets in N=2 supergravity are presented, in this the gauge group may be either compact or noncompact. The scalar multiplets geometry corresponds to nonlinear σ, models of the form Sp(2,2n)/Sp(2)xSp(2n), SU(2,n)/SU(2)SU(n)xU(1) and O(4,n)/O(4)xO(n)

  12. Wavepacket scattering in potential theory

    International Nuclear Information System (INIS)

    Weber, T.A.; Hammer, C.L.

    1977-01-01

    A contour integration technique is developed which enforces the initial conditions for wavepacket-potential scattering. The expansion coefficients for the exact energy eigenstate expansion are automatically expressed in terms of the plane wave expansion coefficients of the initial wavepacket, thereby simplifying what is usually a tedious, mathematical process. The method is applicable regardless of the initial spatial separation of the wavepacket from the scattering center

  13. A relativistic quarkonium potential model

    International Nuclear Information System (INIS)

    Klima, B.; Maor, U.

    1984-04-01

    We review a recently developed relativistic quark-antiquark bound state equation using the expansion in intermediate states. Using a QCD motivated potential we succeeded very well to fit both the heavy systems (banti b, canti c) and the light systems (santi s, uanti u and danti d). Here we emphasize our results on heavy-light sustems and on the possible (tanti t) family. (orig.)

  14. Nuclear energy: potentiality and implications

    International Nuclear Information System (INIS)

    Bahgat, Gawdat

    2008-01-01

    After a discussion about a broad definition of energy security and about the main challenges facing a potential nuclear renaissance, the article analyses how the European Union and the United States have addressed these challenges. There is no doubt that nuclear power will remain an important component of global energy mix, but it should not be seen as a panacea to the flows in the global energy markets [it

  15. Potential energy function of CN-

    Czech Academy of Sciences Publication Activity Database

    Špirko, Vladimír; Polák, Rudolf

    2008-01-01

    Roč. 248, č. 1 (2008), s. 77-80 ISSN 0022-2852 R&D Projects: GA MŠk LC512; GA AV ČR IAA400550511; GA AV ČR IAA400400504 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : potential energy curve * fundamental transition * spectroscopic constants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.636, year: 2008

  16. Potential Psychiatric Uses for MDMA

    OpenAIRE

    Yazar?Klosinski, BB; Mithoefer, MC

    2017-01-01

    Phase II trials of 3,4?methylenedioxymethamphetamine (MDMA)?assisted psychotherapy have demonstrated initial safety and efficacy for treatment of posttraumatic stress disorder (PTSD), with potential for expansion to depression and anxiety disorders. In these trials, single doses of MDMA are administered in a model of medication?assisted psychotherapy, differing from trials involving daily drug administration without psychotherapy. This model presents an opportunity to utilize accelerated regu...

  17. Geothermal Direct Heat Application Potential

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, Paul J

    1989-01-01

    The geothermal direct-use industry growth trends, potential, needs, and how they can be met, are addressed. Recent investigations about the current status of the industry and the identification of institutional and technical needs provide the basis on which this paper is presented. Initial drilling risk is the major obstacle to direct-use development. The applications presented include space and district heating projects, heat pumps (heating and cooling), industrial processes, resorts and pools, aquaculture and agriculture.

  18. Aggregate Supply and Potential Output

    OpenAIRE

    Razin, Assaf

    2004-01-01

    The New-Keynesian aggregate supply derives from micro-foundations an inflation-dynamics model very much like the tradition in the monetary literature. Inflation is primarily affected by: (i) economic slack; (ii) expectations; (iii) supply shocks; and (iv) inflation persistence. This paper extends the New Keynesian aggregate supply relationship to include also fluctuations in potential output, as an additional determinant of the relationship. Implications for monetary rules and to the estimati...

  19. Whole Protein Native Fitness Potentials

    Science.gov (United States)

    Faraggi, Eshel; Kloczkowski, Andrzej

    2013-03-01

    Protein structure prediction can be separated into two tasks: sample the configuration space of the protein chain, and assign a fitness between these hypothetical models and the native structure of the protein. One of the more promising developments in this area is that of knowledge based energy functions. However, standard approaches using pair-wise interactions have shown shortcomings demonstrated by the superiority of multi-body-potentials. These shortcomings are due to residue pair-wise interaction being dependent on other residues along the chain. We developed a method that uses whole protein information filtered through machine learners to score protein models based on their likeness to native structures. For all models we calculated parameters associated with the distance to the solvent and with distances between residues. These parameters, in addition to energy estimates obtained by using a four-body-potential, DFIRE, and RWPlus were used as training for machine learners to predict the fitness of the models. Testing on CASP 9 targets showed that our method is superior to DFIRE, RWPlus, and the four-body potential, which are considered standards in the field.

  20. Biological Potential in Serpentinizing Systems

    Science.gov (United States)

    Hoehler, Tori M.

    2016-01-01

    Generation of the microbial substrate hydrogen during serpentinization, the aqueous alteration of ultramafic rocks, has focused interest on the potential of serpentinizing systems to support biological communities or even the origin of life. However the process also generates considerable alkalinity, a challenge to life, and both pH and hydrogen concentrations vary widely across natural systems as a result of different host rock and fluid composition and differing physical and hydrogeologic conditions. Biological potential is expected to vary in concert. We examined the impact of such variability on the bioenergetics of an example metabolism, methanogenesis, using a cell-scale reactive transport model to compare rates of metabolic energy generation as a function of physicochemical environment. Potential rates vary over more than 5 orders of magnitude, including bioenergetically non-viable conditions, across the range of naturally occurring conditions. In parallel, we assayed rates of hydrogen metabolism in wells associated with the actively serpentinizing Coast Range Ophiolite, which includes conditions more alkaline and considerably less reducing than is typical of serpentinizing systems. Hydrogen metabolism is observed at pH approaching 12 but, consistent with the model predictions, biological methanogenesis is not observed.

  1. Streaming potential of superhydrophobic microchannels.

    Science.gov (United States)

    Park, Hung Mok; Kim, Damoa; Kim, Se Young

    2017-03-01

    For the purpose of gaining larger streaming potential, it has been suggested to employ superhydrophobic microchannels with a large velocity slip. There are two kinds of superhydrophobic surfaces, one having a smooth wall with a large Navier slip coefficient caused by the hydrophobicity of the wall material, and the other having a periodic array of no- shear slots of air pockets embedded in a nonslip wall. The electrokinetic flows over these two superhydrophobic surfaces are modelled using the Navier-Stokes equation and convection-diffusion equations of the ionic species. The Navier slip coefficient of the first kind surfaces and the no-shear slot ratio of the second kind surfaces are similar in the sense that the volumetric flow rate increases as these parameter values increase. However, although the streaming potential increases monotonically with respect to the Navier slip coefficient, it reaches a maximum and afterward decreases as the no-shear ratio increases. The results of the present investigation imply that the characterization of superhydrophobic surfaces employing only the measurement of volumetric flow rate against pressure drop is not appropriate and the fine structure of the superhydrophobic surfaces must be verified before predicting the streaming potential and electrokinetic flows accurately. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Natural gas potential in Canada

    International Nuclear Information System (INIS)

    1997-01-01

    An independent assessment of the undiscovered gas potential in Canada was conducted by a group of volunteer geoscientists. This report is the first of a series of assessments that are planned to be issued every three to four years. Separate assessments were made of conventional gas resources, unconventional gas resources and frontier gas resources. The assessment for conventional gas resources was organized into three categories: (1) gas producing areas where new discoveries can be integrated into existing producing and transportation infrastructure, (2) frontier basins where gas discoveries have been made, but no production is currently underway, and (3) frontier areas where gas-containing sedimentary rocks are known to exist, but where no gas discoveries have been made to date. The committee used year-end 1993 reserves data from discovered pools in each exploration play to predict the undiscovered potential. Information about discovered pools, geological setting, geographic limits and pool sizes of undiscovered pools in each exploration play was provided. Results of the investigation led to the conclusion that the natural gas potential in Canada is in fact larger than hitherto expected. It was estimated that in the Western Canada Sedimentary Basin 47 per cent of the total volume of conventional gas is yet to be discovered. 152 figs

  3. Worldwide potential of wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Flavin, C

    1982-01-01

    A well-documented discussion is presented dealing with the worldwide potential of wind energy as a source of electrical and mechanical power. It is pointed out that 2% of the solar insolation is converted to wind kinetic energy; it is constantly renewed and nondepletable. Efficiency of windmills are discussed (20 to 40%) and payback periods of less than 5 years are cited. Effects of wind velocity and site location are described. Wind pumps are reviewed and the need for wind pumps, particularly in the developing countries is stressed. The generation of electricity by windmills using small turbines is reviewed and appears promising in areas with wind velocities greater than 12 mi/hr. The development of large windmills and groups of windmills (windfarms) for large scale electrical power is discussed, illustrated, and reviewed (offshore sites included). Environmental and safety problems are considered as well as the role of electrical utilities, government support and research activities. It is concluded that the potential contribution of wind energy is immense and that mechanical windmills may become one of the most important renewable technologies. Electrical generating potential is estimated at 20 to 30% of electrical needs. International programs are discussed briefly. 57 references. (MJJ)

  4. Energy intensities: Prospects and potential

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    In the previous chapter, the author described how rising activity levels and structural change are pushing toward higher energy use in many sectors and regions, especially in the developing countries. The extent to which more activity leads to greater energy use will depend on the energy intensity of end-use activities. In this chapter, the author presents an overview of the potential for intensity reductions in each sector over the next 10-20 years. It is not the author's intent to describe in detail the various technologies that could be employed to improve energy efficiency, which has been done by others (see, for example, Lovins ampersand Lovins, 1991; Goldembert et al., 1987). Rather, he discusses the key factors that will shape future energy intensities in different parts of the world, and gives a sense for the changes that could be attained if greater attention were given to accelerate efficiency improvement. The prospects for energy intensities, and the potential for reduction, vary among sectors and parts of the world. In the majority of cases, intensities are tending to decline as new equipment and facilities come into use and improvements are made on existing stocks. The effect of stock turnover will be especially strong in the developing countries, where stocks are growing at a rapid pace, and the Former East Bloc, where much of the existing industrial plant will eventually be retired and replaced with more modern facilities. While reductions in energy intensity are likely in most areas, there is a large divergence between the technical and economic potential for reducing energy intensities and the direction in which present trends are moving. In the next chapter, the author presents scenarios that illustrate where trends are pointing, and what could be achieved if improving energy efficiency were a focus of public policies. 53 refs., 4 figs., 2 tabs

  5. Cosmology and the Sinusoidal Potential

    Science.gov (United States)

    Bartlett, David F.

    2006-06-01

    The nature of dark matter (and dark energy) remains a mystery. An alternative is being explored by several scientists: changing Newton's (and Einstein's) field equations. The sinusoidal potential is the latest attempt[1]. Here the gravitational law is alternately attractive and repulsive:φ = -GM cos(kor)/r, where λo=2π/ko = 1/20 of the distance from the sun to the center of the Milky Way. The proposal accommodates several structural features of the Milky Way including, paradoxically, its spiral shape and flat rotation curve. The sinusoidal potential's unique feature is strong galactic tidal forces (dg/dr). These may explain why the new planetoid Sedna is securely between the Kuiper Belt and the Oort cloud and why distant comets are more influenced by galactic tides that are in the r, rather than the z-direction.At this meeting I discuss the consequences of the sinusoidal potential for cosmology. Here the alternation of attraction and repulsion gives (i) an open universe, and (ii) gravitational lensing which is usually weak, but occasionally very strong. An open universe is one that, asymptotically, has a size R which varies directly as time t. The open universe conflicts both with the old Einstein-deSitter model (R α t2/3} and the new accelerating one. The evidence for an accelerating universe decisively rejects the Einstein-deSitter model. The rejection of an open (or empty) universe is less secure. This rejection is influenced by the different ways the groups studying the brightness of supernovae use the HST. Surprising additional inputs include neutrino masses, the equivalence principle, LSB galaxies, and "over-luminous" Sn1a. I thank Mostafa Jon Dadras and Patrick Motl for early help and John Cumalat for continual support. [1] D.F. Bartlett, "Analogies between electricity and gravity", Metrologia 41, S115-S124 (2004).

  6. World potential of renewable energies

    Energy Technology Data Exchange (ETDEWEB)

    Dessus, B; Devin, B; Pharabod, F

    1991-07-01

    A comprehensive analysis, region by region, of the actually accessible renewable energies at a given horizon, is presented. The same methodology as the one employed to derive ``proven fossil energy reserves`` from ``energy resources`` is adopted, in which resources are defined by quantitative information on physical potential, while reserves take into account technical and economical accessibility. As renewable resources are fluctuating with time and are diluted in space and not readily transportable or storeable, it is necessary to consider the presence of populations or activities near enough to be able to profit by these diluted and volatile energies.

  7. Ethnography: principles, practice and potential.

    Science.gov (United States)

    Draper, Jan

    2015-05-06

    Ethnography is a methodology that is gaining popularity in nursing and healthcare research. It is concerned with studying people in their cultural context and how their behaviour, either as individuals or as part of a group, is influenced by this cultural context. Ethnography is a form of social research and has much in common with other forms of qualitative enquiry. While classical ethnography was characteristically concerned with describing 'other' cultures, contemporary ethnography has focused on settings nearer to home. This article outlines some of the underlying principles and practice of ethnography, and its potential for nursing and healthcare practice.

  8. The Ergogenic Potential of Arginine

    Directory of Open Access Journals (Sweden)

    La Bounty Paul M

    2004-12-01

    Full Text Available Abstract Arginine is a conditionally essential amino acid that is involved in protein synthesis, the detoxification of ammonia, and its conversion to glucose as well as being catabolized to produce energy. In addition to these physiological functions, arginine has been purported to have ergogenic potential. Athletes have taken arginine for three main reasons: 1 its role in the secretion of endogenous growth hormone; 2 its involvement in the synthesis of creatine; 3 its role in augmenting nitric oxide. These aspects of arginine supplementation will be discussed as well as a review of clinical investigations involving exercise performance and arginine ingestion.

  9. Analgesic Potential of Essential Oils

    Directory of Open Access Journals (Sweden)

    José Ferreira Sarmento-Neto

    2015-12-01

    Full Text Available Pain is an unpleasant sensation associated with a wide range of injuries and diseases, and affects approximately 20% of adults in the world. The discovery of new and more effective drugs that can relieve pain is an important research goal in both the pharmaceutical industry and academia. This review describes studies involving antinociceptive activity of essential oils from 31 plant species. Botanical aspects of aromatic plants, mechanisms of action in pain models and chemical composition profiles of the essential oils are discussed. The data obtained in these studies demonstrate the analgesic potential of this group of natural products for therapeutic purposes.

  10. Proprioceptive evoked potentials in man

    DEFF Research Database (Denmark)

    Arnfred, S; Chen, A C; Eder, Derek N

    2000-01-01

    We studied cerebral evoked potentials on the scalp to the stimulation of the right hand from a change in weight of 400-480 g in ten subjects. Rise-time was 20g/10 ms, Inter Stimulus Interval 2s and stimulus duration was 100 ms. The cerebral activations were a double positive contralateral C3'/P70......). Further studies of the PEP are needed to assess the influence of load manipulations and of muscle contraction and to explore the effect of attentional manipulation....

  11. Potential Psychiatric Uses for MDMA.

    Science.gov (United States)

    Yazar-Klosinski, B B; Mithoefer, M C

    2017-02-01

    Phase II trials of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy have demonstrated initial safety and efficacy for treatment of posttraumatic stress disorder (PTSD), with potential for expansion to depression and anxiety disorders. In these trials, single doses of MDMA are administered in a model of medication-assisted psychotherapy, differing from trials involving daily drug administration without psychotherapy. This model presents an opportunity to utilize accelerated regulatory pathways, such as the US Food and Drug Administration (FDA) Breakthrough Therapy Designation, to most effectively and expeditiously test such novel approaches. © 2016, The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  12. Calculation of Rydberg interaction potentials

    DEFF Research Database (Denmark)

    Weber, Sebastian; Tresp, Christoph; Menke, Henri

    2017-01-01

    for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up...... to higher multipole orders on a desktop computer. Finally, we present example calculations showing the relevance of the full interaction calculation to current experiments. Our software for calculating Rydberg potentials including all features discussed in this tutorial is available as open source....

  13. Theory of complex potential scattering

    International Nuclear Information System (INIS)

    Kok, L.P.; Haeringen, H.v.

    1981-01-01

    We study the effect of the addition of a complex potential lambdaV/sub sep/ to an arbitrary Schroedinger operator H = H 0 +V on the singularities of the S matrix, as a function of lambda. Here V/sub sep/ is a separable interaction, and lambda is a complex coupling parameter. The paths of these singularities are determined to a great extent by certain saddle points in the momentum (or energy) plane. We explain certain critical phenomena recently reported in the literature. Associated with these saddles are branch-type singularities in the complex lambda plane, which are dynamical in origin. Some examples are discussed in detail

  14. Nanothermodynamics: a subdivision potential approach

    Directory of Open Access Journals (Sweden)

    R. Moussavi

    2005-12-01

    Full Text Available  Classical thermodynamic laws and relations have been developed for macroscopic systems that satisfy the thermodynamic limit. These relations are challenged as the system size decreases to the scale of nano-systems, in which thermodynamic properties are overshadowed by system size, and the usual classical concepts of extensivity and intensivity are no longer valid. The challenges to the classical thermodynamics in relation to small systems are demonstrated, and via the approach introduced by Hill, the concept of sub-division potential is clarified in details. The fundamental thermodynamic relations are obtained using a rational-based method.

  15. Potential benefits from the CTBT

    International Nuclear Information System (INIS)

    Chang, H.L.

    1999-01-01

    Discussing the potential benefits from the CTBT monitoring in Africa, analysis and data communication systems it was concluded that although yet undeveloped, the possibilities arising from participation in CTBT regime are being identified. The integrated data obtained from the verification technologies of the CTBT should open further horizons for civil society. The main topics of interest are: treaty related science and technology developments, monitoring techniques, ideas and initiatives for expanding existing activities and developing cooperation, including the issues of regional centres and centres of excellence

  16. The effective crystal field potential

    CERN Document Server

    Mulak, J

    2000-01-01

    As it results from the very nature of things, the spherical symmetry of the surrounding of a site in a crystal lattice or an atom in a molecule can never occur. Therefore, the eigenfunctions and eigenvalues of any bound ion or atom have to differ from those of spherically symmetric respective free ions. In this way, the most simplified concept of the crystal field effect or ligand field effect in the case of individual molecules can be introduced. The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, ar...

  17. Calculation of Rydberg interaction potentials

    International Nuclear Information System (INIS)

    Weber, Sebastian; Büchler, Hans Peter; Tresp, Christoph; Urvoy, Alban; Hofferberth, Sebastian; Menke, Henri; Firstenberg, Ofer

    2017-01-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence can be fine-tuned with great flexibility by choosing appropriate Rydberg states and applying external electric and magnetic fields. More and more experiments are probing this interaction at short atomic distances or with such high precision that perturbative calculations as well as restrictions to the leading dipole–dipole interaction term are no longer sufficient. In this tutorial, we review all relevant aspects of the full calculation of Rydberg interaction potentials. We discuss the derivation of the interaction Hamiltonian from the electrostatic multipole expansion, numerical and analytical methods for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up to higher multipole orders on a desktop computer. Finally, we present example calculations showing the relevance of the full interaction calculation to current experiments. Our software for calculating Rydberg potentials including all features discussed in this tutorial is available as open source. (tutorial)

  18. Potential energy center site investigations

    International Nuclear Information System (INIS)

    Savage, W.F.

    1977-01-01

    Past studies by the AEC, NRC, NSF and others have indicated that energy centers have certain advantages over dispersed siting. There is the need, however, to investigate such areas as possible weather modifications due to major heat releases, possible changes in Federal/state/local laws and institutional arrangements to facilitate implementation of energy centers, and to assess methods of easing social and economic pressures on a surrounding community due to center construction. All of these areas are under study by ERDA, but there remains the major requirement for the study of a potential site to yield a true assessment of the energy center concept. In this regard the Division of Nuclear Research and Applications of ERDA is supporting studies by the Southern and Western Interstate Nuclear Boards to establish state and utility interest in the concept and to carry out screening studies of possible sites. After selection of a final site for center study , an analysis will be made of the center including technical areas such as heat dissipation methods, water resource management, transmission methods, construction methods and schedules, co-located fuel cycle facilities, possible mix of reactor types, etc. Additionally, studies of safeguards, the interaction of all effected entities in the siting, construction, licensing and regulation of a center, labor force considerations in terms of local impact, social and economic changes, and financing of a center will be conducted. It is estimated that the potential site study will require approximately two years

  19. Safety assessments for potential exposures

    International Nuclear Information System (INIS)

    Dunn, D.I.

    2012-04-01

    Safety Assessment of potential exposures have been carried out in major practices, namely: industrial radiography, gamma irradiators and electron accelerators used in industry and research, and radiotherapy. This paper focuses on reviewing safety assessment methodologies and using developed software to analyse radiological accidents, also review, and discuss these past accidents.The primary objective of the assessment is to assess the adequacy of planned or existing measures for protection and safety and to identify any additional measures that should be put in place. As such, both routine use of the source and the probability and magnitude of potential exposures arising from accidents or incidents should be considered. Where the assessment indicates that there is a realistic possibility of an accident affecting workers or members of the public or having consequences for the environment, the registrant or licensee should prepare a suitable emergency plan. A safety assessment for normal operation addresses all the conditions under which the radiation source operates as expected, including all phases of the lifetime of the source. Due account needs to be taken of the different factors and conditions that will apply during non-operational phases, such as installation, commissioning and maintenance. (author)

  20. Convexity of the effective potential

    International Nuclear Information System (INIS)

    Haymaker, R.W.; Perez-Mercader, J.

    1978-01-01

    The effective potential V(phi) in field theories is a convex function of phi. V(lambda phi 1 + (1 - lambda)phi 2 ) less than or equal to lambdaV(phi 1 ) + (1 - lambda)V(phi 2 ), 0 less than or equal to lambda less than or equal to 1, all phi 1 , phi 2 . A linear interpolation of V(phi) is always larger than or equal to V(phi). There are numerous examples in the tree approximation and in perturbation theory for which this is not the case, the most notorious example being the double dip potential. More complete solutions may or may not show this property automatically. However, a non-convex V(phi) simply indicates that an unstable vacuum state was used in implementing the definition of V(phi). A strict definition will instruct one to replace V(phi) with its linear interpolation in such a way as to make it convex. (Alternatively one can just as well take the view that V(phi) is undefined in these domains.) In this note, attention is called to a very simple argument for convexity based on a construction described by H. Callen in his classic book Thermodynamics

  1. Potential hazards of diagnostic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Houston, C S; Shokeir, M H

    1977-03-01

    There are no precise data for determining the extent of somatic damage from small doses of radiation used in diagnostic radiology. Diagnostic radiation given to pregnant women, knowingly or unknowingly, should rarely reach teratogenic levels causing brain and eye abnormalities. Evidence suggests that it does increase the risk of childhood malignancy, especially leukemia. Although rapidly growing tissues seem most susceptible, all radiation probably carries a very small risk of carcinogenesis. Genetic damage is equally difficult to estimate. Diagnostic radiation of females, even in childhood, may be related to an increased incidence of Down's syndrome in older mothers. Radiation also causes point mutations, which may explain the increase of some genetic abnormalities in progeny of older fathers. Whenever an abdominal or pelvic radiograph is ordered before the end of the reproductive period, there must be a potential benefit to balance the small risk involved.

  2. The potential of renewable energies

    International Nuclear Information System (INIS)

    Glubrecht, H.

    1998-01-01

    If one compares the progress in research and development of renewable energy applications with the finding which has been granted to these activities during the 23 years after the first oil shock, one cannot but be very impressed. It is indicated in this paper hoe comprehensive the potential of renewable energy is. One should take into account that the methods described form a broad interdisciplinary field in contrast to fossil and nuclear technologies. From technical point of view the present and future energy demand can be met by the broad spectrum of renewable energies in combination with energy conservation. Many of these techniques are already economically competitive: solar architecture, wind energy, hydropower, low temperature heat production, photovoltaic for remote areas, various types of biomass application, geothermal energy although not exactly renewable. The future of renewable energies will depend on opening markets for these techniques

  3. Sustainability Potentials of Housing Refurbishment

    Directory of Open Access Journals (Sweden)

    Behzad Sodagar

    2013-03-01

    Full Text Available The benefits of choosing refurbishment over new build have recently been brought into focus for reducing environmental impacts of buildings. This is due to the fact that the existing buildings will comprise the majority of the total building stocks for years to come and hence will remain responsible for the majority of greenhouse gas emissions from the sector. This paper investigates the total potentials of sustainable refurbishment and conversion of the existing buildings by adopting a holistic approach to sustainability. Life Cycle Assessment (LCA and questionnaires have been used to analyse the environmental impact savings (Co2e, improved health and well-being, and satisfaction of people living in refurbished homes. The results reported in the paper are based on a two year externally funded research project completed in January 2013.

  4. Potential risks of nuclear ships

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1994-07-01

    This report represents an attempt to evaluate the potential risks of nuclear ships. Firstly reasons are given why nuclear ship accidents will not lead to accidents of the magnitude of the Chernobyl accident. This is due to much lower content of radioactive material and to different reactor designs. Next a review is given of the types of accidents which have actually occurred. Of these the reactor accidents which may lead to serious consequences for the crew and the environment are considered further. These are reactivity accidents and loss of coolant accidents. In addition the long term risks of sunken nuclear ships and sea disposed reactor compartments etc. are also discussed. Based on available accident data an attempt is made to estimate the probability of serious nuclear ship accidents. (au)

  5. Introduction: Translating Potential into Profits

    DEFF Research Database (Denmark)

    Lubinski, Christina; Kipping, Matthias

    2015-01-01

    potential into profits.’ The history of multinational enterprises (MNEs) knows many examples of economies with these characteristics similar to modern understandings of ‘emerging markets.’ This special issue analyzes foreign multinationals in emerging markets from a historical perspective. It seeks...... to understand changes and continuities in the opportunities and challenges less developed markets presented for MNEs, and in the various ways in which their managers responded to these. Rather than relying on the ‘emerging market’ label, we ask (1) why managers perceived certain markets as ‘emerging’ and which...... expectations they had when investing in these markets, (2) which challenges they faced there, and (3) how they subsequently addressed them. By tracing and comparing these investments and their consequences over time (and space), we hope to shed more light on managerial decisions and understand to what extent...

  6. Potentialities of Revised Quantum Electrodynamics

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2013-10-01

    Full Text Available The potentialities of a revised quantum electrodynamic theory (RQED earlier established by the author are reconsidered, also in respect to other fundamental theories such as those by Dirac and Higgs. The RQED theory is characterized by intrinsic linear symmetry breaking due to a nonzero divergence of the electric field strength in the vacuum state, as supported by the Zero Point Energy and the experimentally confirmed Casimir force. It includes the results of electron spin and antimatter by Dirac, as well as the rest mass of elementary particles predicted by Higgs in terms of spontaneous nonlinear symmetry breaking. It will here be put into doubt whether the approach by Higgs is the only theory which becomes necessary for explaining the particle rest masses. In addition, RQED theory leads to new results beyond those being available from the theories by Dirac, Higgs and the Standard Model, such as in applications to leptons and the photon.

  7. Antidiabetic potential of Conocarpus lancifolius

    Directory of Open Access Journals (Sweden)

    Malik Saadullah

    2014-06-01

    Full Text Available The antidiabetic activity of Conocarpus lancifolius extract was investigated in vitro, as alpha glucosidase inhibition and in vivo as alloxan induced diabetic rabbits with other biochemical parameters (LDL, HDL, SGPT, SGOT, cretinine, urea and triglyceride. Alpha-glucosidase inhibition activity was performed by using acorbose as standred. Methanolic extract show alpha-glucosidase inhibition activity. The dose of 200 mg/kg body weight significantly (p<0.05 decreases the blood glucose level, plasma total cholesterol, triglycerides and LDL in treated rabbits as compared to diabetic rabbits. This dose significantly increased the level of HDL in treated group. The activity of SGOT and SGPT also significantly (p<0.05 decreased in treated diabetic rabbits. Phytochemical studies show the presence of glycosides, tannins, saponins and terpenoids. The antidiabetic potential is may be due to its saponin contents.

  8. Prediction of acid generation potential

    International Nuclear Information System (INIS)

    Nalbandyan, V.B.

    1992-01-01

    This paper discusses acid rock drainage (ARD), a term used to describe leachate, seepage, or drainage that has been affected by the natural oxidation of sulfide minerals contained in rock which is exposed to air and water. The principal ingredients for ARD formation are reactive sulfide minerals, oxygen, and water. The oxidation reactions responsible for the formation of ARD are often accelerated by biological activity. These reactions yield low pH (acidic) water that has the potential to mobilize heavy metals that may be contained in the geologic materials that are contacted. ARD can cause a detrimental impact on the quality of ground or surface water to which it discharges. ARD likely has been associated with mines since mining began. ARD is not necessarily confined to mining activities, but can occur naturally wherever sulfide-bearing rock is exposed to air and water. It is important to recognize that not all operations that expose sulfide-bearing rock will result in ARD

  9. The potential of wind farms

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Summaries of papers presented at the European wind energy conference on the potential of wind farms are presented. It is stated that in Denmark today, wind energy provides about 3% to the Danish electricity consumption and the wind power capacity is, according to Danish wind energy policy, expected to increase substantially in the years to come. A number of countries in Europe and elsewhere are making significant progress in this repect. Descriptions of performance are given in relation to some individual wind farms. The subjects covered concern surveys of national planning and policies regarding wind utilization and national and global development of wind turbine arrays. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigue, wakes, noise and control. (AB).

  10. Unleashing the Potential of SCM

    DEFF Research Database (Denmark)

    Møller, Charles

    2005-01-01

    This paper argues that with the present state of Enterprise Resource Planning (ERP) adoption by the companies, the potential benefits of Supply Chain Management (SCM) and integration is about to be unleashed. This paper presents the results and the implications of a survey on ERP adoption...... in the 500 largest Danish enterprises. The study is based on telephone interviews with ERP managers in 88.4 % of the "top 500" enterprises in Denmark. Based on the survey, the paper suggests the following four propositions: (i) ERP has become the pervasive infrastructure; (ii) ERP has become a contemporary...... technology; (iii) ERP adoption has matured; and (iv) ERP adoption is converging towards a dominant design. Finally, the paper discusses the general implications of the surveyed state of practice on the SCM research challenges. Consequently we argue that research needs to adjust its conceptions of the ERP...

  11. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Cowart, C.G.; Notz, K.J.

    1992-10-01

    This report presents the results of a fully documented peer review of DOE/RW-0184, Rev. 1, ''Characteristics of Potential Repository Wastes''. The peer review was chaired and administered by oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) and was conducted in accordance with OCRWM QA procedure QAAP 3.3 ''Peer Review'' for the purpose of quailing the document for use in OCRWM quality-affecting work. The peer reviewers selected represent a wide range of experience and knowledge particularly suitable for evaluating the subject matter. A total of 596 formal comments were documented by the seven peer review panels, and all were successfully resolved. The peers reached the conclusion that DOE/RW-0184, Rev. 1, is quality determined and suitable for use in quality-affecting work

  12. Status of effective potential calculations

    CERN Document Server

    Quiros, M.

    1995-01-01

    We review various effective potential methods which have been useful to compute the Higgs mass spectrum and couplings of the minimal supersymmetric standard model. We compare results where all-loop next-to-leading-log corrections are resummed by the renormalization group, with those where just the leading-log corrections are kept. Pole masses are obtained from running masses by addition of convenient self-energy diagrams. Approximate analytical expressions are worked out, providing an excellent approximation to the numerical results which include all next-to-leading-log terms. An appropriate treatment of squark decoupling allows to consider large values of the stop and/or sbottom mixing parameters and thus fix a reliable upper bound on the mass of the lightest CP-even Higgs boson mass.

  13. "Human potential" and progressive pedagogy

    DEFF Research Database (Denmark)

    Øland, Trine

    2012-01-01

    This article examines the cultural constructs of progressive pedagogy in Danish school pedagogy and its emerging focus on the child’s human potential from the 1920s to the 1950s. It draws on Foucault’s notion of ‘dispositifs’ and the ‘elements of history’, encircling a complex transformation......: the emergence of ‘intelligence’ and life as a biological phenomenon from the 1920s is illustrated; the emergence of ‘Black culture’, ‘Negros’ and ‘races’ from the 1930s is depicted, and the emergence of ‘national cultures’ from the 1940s – enhanced by UNESCO after World War II – is demonstrated. Although race...

  14. Corrected body surface potential mapping.

    Science.gov (United States)

    Krenzke, Gerhard; Kindt, Carsten; Hetzer, Roland

    2007-02-01

    In the method for body surface potential mapping described here, the influence of thorax shape on measured ECG values is corrected. The distances of the ECG electrodes from the electrical heart midpoint are determined using a special device for ECG recording. These distances are used to correct the ECG values as if they had been measured on the surface of a sphere with a radius of 10 cm with its midpoint localized at the electrical heart midpoint. The equipotential lines of the electrical heart field are represented on the virtual surface of such a sphere. It is demonstrated that the character of a dipole field is better represented if the influence of the thorax shape is reduced. The site of the virtual reference electrode is also important for the dipole character of the representation of the electrical heart field.

  15. The potential of the internet.

    Science.gov (United States)

    Coleman, Jamie J; McDowell, Sarah E

    2012-06-01

    The internet and the World Wide Web have changed the ways that we function. As technologies grow and adapt, there is a huge potential for the internet to affect drug research and development, as well as many other aspects of clinical pharmacology. We review some of the areas of interest to date and discuss some of the potential areas in which internet-based technology can be exploited. Information retrieval from the web by health-care professionals is common, and bringing evidence-based medicine to the bedside affects the care of patients. As a primary research tool the web can provide a vast array of information in generating new ideas or exploring previous research findings. This has facilitated systematic reviewing, for example. The content of the web has become a subject of research in its own right. The web is also widely used as a research facilitator, including enhancement of communication between collaborators, provision of online research tools (such as questionnaires, management of large scale multicentre trials, registration of clinical trials) and distribution of information. Problems include information overload, ignorance of early data that are not indexed in databases, difficulties in keeping web sites up to date and assessing the validity of information retrieved. Some web-based activities are viewed with suspicion, including analysis by pharmaceutical companies of drug information to facilitate direct-to-consumer advertising of novel pharmaceuticals. Use of these technologies will continue to expand in often unexpected ways. Clinical pharmacologists must embrace internet technology and include it as a key priority in their research agenda. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  16. Smallholder telecoupling and potential sustainability

    Directory of Open Access Journals (Sweden)

    Karl S. Zimmerer

    2018-03-01

    Full Text Available Smallholders are crucial for global sustainability given their importance to food and nutritional security, agriculture, and biodiversity conservation. Worldwide smallholders are subject to expanded telecoupling whereby their social-ecological systems are linked to large-scale socioeconomic and environmental drivers. The present research uses the synthesis of empirical evidence to demonstrate smallholder telecoupling through the linkages stemming from the global-level integration of markets (commodity, labor, finance, urbanization, governance, and technology. These telecoupling forces are often disadvantageous to smallholders while certain conditions can contribute to the potential sustainability of their social-ecological systems. Case studies were chosen to describe sustainability opportunities and limits involving smallholder production and consumption of high-agrobiodiversity Andean maize amid telecoupled migration (Bolivia, the role of international eco-certification in smallholder coffee-growing and agroforests (Colombia, smallholder organic dairy production in large-scale markets and technology transfer (upper Midwest, U.S.A., and smallholders' global niche commodity production of argan oil (Morocco. These case studies are used to identify the key challenges and opportunities faced by smallholders in telecoupling and to develop a conceptual framework. This framework specifies the integrated roles of global systems together with influential public and private institutions operating at multiple scales including the national level. The framework also integrates the local dynamics of smallholders' multiple land use units and their socioeconomic and environmental variation. Spatial spillover effects in smallholder landscapes are an additional element. This framework further establishes the un-Romantic, nonteleological, and antifetishistic view of smallholders. It provides specific insights on the multilevel dynamics of smallholder telecoupling

  17. The phenomenon of retarded potentials

    International Nuclear Information System (INIS)

    Noskov, N.K.

    2003-01-01

    The logic simulation of process of time delay of potential on a moved body - recipient resulted in the deduction about cyclic irregularity of time delay, that means, that the moved body makes longitudinal vibrations. A conclusion is drawn that length of longitudinal vibrations depending from three variable: the law of interaction, spacing interval between bodies of interaction and phase velocity looks like: λ=Hv ph /R·F(R) (1), where λ- length of oscillations; H- factor of proportionality; v ph - phase velocity of a body; R - distance between test and central bodies R(t); F(R) - law of interaction. So far as λ=v ph /v, and R·F(R)=∫ ∞ R F(R)dR=E move , then formula (1) will be transformed into: E move =Hv pv /λ=Hv. Thus, the energy of radiating having the similar law is only reflex of motion of a matter. The energy of oscillating motion can be expressed through linear maximal velocity. It is established, that different expressions of the same energy, result in the law of a view of a proportion for lengths of de Broglie's waves: It shows that de Broglie's waves - the actual oscillating motions of bodies, as demonstrate interference and diffraction pictures at a dissipation of the accelerated particles on crystalline gratings. This deduction has far-reaching consequences for finding - out of the cause bases of the laws of a nature. So, the quantum mechanics becomes partition of mechanics of solids and is comprises all interactions. The nuclear energy is not 'defect of mass', but is 'defect' of energy of oscillating motion: ΔE=H v1 -H v2 . Definition of real cause of nuclear energy is very important for construction of model of nuclei and for development of physics as the whole. The interconnection of the phenomenon of longitudinal vibrations of moved bodies, as result of irregularity of time delay of potential, with many other natural phenomena is looked through. By such, as: motion of planets and electrons on elliptical orbits, oscillating of dipping drips

  18. The potential of renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    On June 27 and 28, 1989, the US Department of Energy (DOE) national laboratories were convened to discuss plans for the development of a National Energy Strategy (NES) and, in particular, the analytic needs in support of NES that could be addressed by the laboratories. As a result of that meeting, interlaboratory teams were formed to produce analytic white papers on key topics, and a lead laboratory was designated for each core laboratory team. The broad-ranging renewables assignment is summarized by the following issue statement from the Office of Policy, Planning and Analysis: to what extent can renewable energy technologies contribute to diversifying sources of energy supply What are the major barriers to greater renewable energy use and what is the potential timing of widespread commercialization for various categories of applications This report presents the results of the intensive activity initiated by the June 1989 meeting to produce a white paper on renewable energy. Scores of scientists, analysts, and engineers in the five core laboratories gave generously of their time over the past eight months to produce this document. Their generous, constructive efforts are hereby gratefully acknowledged. 126 refs., 44 figs., 32 tabs.

  19. The biomethane potential in Chile

    International Nuclear Information System (INIS)

    Seiffert, M.; Kaltschmitt, M.; Miranda, J.A.

    2009-01-01

    Within the last decade natural gas gained considerable importance in Chile. The contribution of natural gas within the energy system will increase in the future by predicted 3.6% annually until the year 2015. Due to limited resources within its own country, the energy system of Chile depends on natural gas imports preferential from Argentina. Therefore, the aim of several stakeholders from policy and industry is to reduce the share of imported primary energy within the overall energy system. In order to reach this goal, the use of domestic resources and particularly the utilisation of biomass as one of the most important renewable sources of energy in Chile could play an important role. Against this background, the goal of this paper is the analysis of the technical potentials of biomethane as a substitute for natural gas. For the production of biomethane the anaerobic or bio-chemical (i.e. Biogas) as well as the thermo-chemical conversion pathways (i.e. Bio-SNG) are considered. The results of this analysis show that biomass converted to biomethane is a promising energy provision option for Chile and it contributes to the reduction of greenhouse gas emissions

  20. The Tectonic Potentials of Concrete

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole

    2013-01-01

    Contemporary techniques for concrete casting in an architectural context are challenged by demands of increased individualization in our built environment, reductions in the use of resources and waste generation. In recent years, new production technologies and strategies that break with the indu......Contemporary techniques for concrete casting in an architectural context are challenged by demands of increased individualization in our built environment, reductions in the use of resources and waste generation. In recent years, new production technologies and strategies that break...... with the industrial paradigm of standardization, have been put forward. This development is carried forward by computers and digital fabrication, but has yet to find its way into the production of building components. With regards to concrete casting, however, existing research do offer advancement towards...... an increased customisation of casting moulds. The hypothesis of this research is that the techniques used in this research do not fully address the tectonic potentials of concrete which gives rise to the primary research question: Is it possible to enhance existing or develop new concrete casting techniques...

  1. Ozone depletion potentials of halocarbons

    International Nuclear Information System (INIS)

    Karol, I.L.; Kiselev, A.A.

    1992-01-01

    The concept of ozone depletion potential (ODP) is widely used in the evaluation of numerous halocarbons and of their replacements for effects on ozone, but the methods, model assumptions and conditions of ODP calculation have not been analyzed adequately. In this paper, a model study of effects on ozone after the instantaneous releases of various amounts of CH 3 CCl 3 and of CHF 2 Cl(HCFC-22) in the several conditions of the background atmosphere are presented, aimed to understand the main connections of ODP values with the methods of their calculations. To facilitate the ODP computation in numerous versions for long after the releases, the above rather short-lived gases have been used. The variation of released gas global mass from 1 Mt to 1 Gt leads to ODP value increase atmosphere. The same variations are analyzed for the CFC-free atmosphere of 1960s conditions for the anthropogenically loaded atmosphere in the 21st century according to the known IPCC- A scenario (business as usual). Recommendations of proper ways of ODP calculations are proposed for practically important cases

  2. Job creation potential of solar

    International Nuclear Information System (INIS)

    McMonagle, R.

    2005-01-01

    This document defines the size of the job market within Canada's solar industry and presents a preliminary forecast of the employment opportunities through to 2025. The issue of job potential within Canada's solar technologies is complicated by the wide range of different fields and technologies within the solar industry. The largest energy generator of the solar technologies is passive solar, but the jobs in this sector are generally in the construction trades and window manufacturers. The Canadian Solar Industries Association estimates that there are about 360 to 500 firms in Canada with the primary business of solar technologies, employing between 900 to 1,200 employees. However, most solar manufacturing jobs in Canada are for products exports as demonstrated by the 5 main solar manufacturers in Canada who estimate that 50 to 95 per cent of their products are exported. The main reason for their high export ratio is the lack of a Canadian market for their products. The 3 categories of job classifications within the solar industry include manufacturing, installation, and operations and maintenance. The indirect jobs include photovoltaic system hardware, solar hot water heating, solar air ventilation, and glass/metal framing. 17 refs., 3 tabs., 2 figs

  3. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Notz, K.J.

    1989-01-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will be disposed of in a geologic repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. Detailed characterizations are required for all of these potential repository wastes. These characterizations include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. This information has been extracted from primary data sources, evaluated, and assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. The Characteristics Data Base provides a standard set of self-consistent data to the various areas of responsibility including systems integration and waste stream analysis, storage, transportation, and geologic disposal. The data will be used for design studies, evaluation of alternatives, and system optimization by OCRWM and supporting contractors. 7 refs., 5 figs., 7 tabs

  4. Galalctic Tides & the Sinusoidal Potential

    Science.gov (United States)

    Bartlett, David F.

    2011-05-01

    The sinusoidal potential is a nonNewtonian alternative to dark matter. Instead of φ = -GM/r we write φ = -(GM/r) cos kor, where ko= 2π/ λo and λo = Ro/20= 400 pc. Evidence for this choice for the "wavelength” λo has been given in one article and many previous meetings of the AAS & DDA. The solar system and nearby stars are trapped in a local groove of width Δr Quality (4 types) and semi-major axis aoriginal . For 10 of the 12 classes radial tides dominate Z-tides. The classic Oort cloud comets (1851-1996) have a particularly strong modulation with galactic longitude. This modulation is exactly in those directions where a radial tide would be important. The equally numerous recent Oort comets (1996-2008) show a different evidence for strong radial tides. The recent comets generally have much larger perihelion distances q than the classic ones. Here the evidence is that a radial tide is removing angular momentum from the orbit and thus bringing the perihelion closer to the earth and to observers.

  5. Biological potential of Stillingia oppositifolia

    Directory of Open Access Journals (Sweden)

    Betania Barros Cota

    2011-02-01

    Full Text Available Organic extracts from leaves and stems of Stillingia oppositifolia Baill. ex Müll. Arg., Euphorbiaceae, were screened for antifungal and cytotoxic properties. The extracts presented Minimum Inhibitory Concentration values around 250 µg.mL-1 against Candida krusei and Candida tropicalis, and around 63 µg.mL-1 for Paracoccidioides brasiliensis. They were tested on three human cell lines (UACC-62, MCF-7, and TK-10, disclosing GI50 values, (concentration able to inhibit 50% of the cell growth ranging from 50 to 100 µg.mL-1. Organic extract from stems furnished hexanic, dichloromethanic and aqueous phases after partition. Chromatographic fractionation of the hexanic soluble phase of the stems yielded aleuritolic acid 3-acetate, β-sitosterol, 3-epi-β-amyrin, β-amyrone and palmitic acid. These compounds showed antifungal and cytotoxic activities in the same range as the organic crude extract and low toxic effect against mononuclear cells obtained from human peripheral blood. This is the first report on chemical and biological potential of S. oppositifolia.

  6. Thermodynamic potential in quantum electrodynamics

    International Nuclear Information System (INIS)

    Morley, P.D.

    1978-01-01

    The thermodynamic potential, Ω, in quantum electrodynamics (QED) is derived using the path-integral formalism. Renormalization of Ω is shown by proving the following theorem: Ω/sub B/(e/sub B/,m/sub B/,T,μ) - Ω/sub B/(e/sub B/,m/sub B/,T = 0,μ = 0) = Ω/sub R/(e/sub R/,m/sub R/,T,μ,S), where B and R refer to bare and renormalized quantities, respectively, and S is the Euclidean subtraction momentum squared. This theorem is proved explicitly to e/sub R/ 4 order and could be analogously extended to any higher order. Renormalization-group equations are derived for Ω/sub R/, and it is shown that perturbation theory in a medium is governed by effective coupling constants which are functions of the density. The behavior of the theory at high densities is governed by the Euclidean ultraviolet behavior of the theory in the vacuum

  7. The Analgesic Potential of Cannabinoids

    Science.gov (United States)

    Elikottil, Jaseena; Gupta, Pankaj; Gupta, Kalpna

    2013-01-01

    Historically and anecdotally cannabinoids have been used as analgesic agents. In recent years, there has been an escalating interest in developing cannabis-derived medications to treat severe pain. This review provides an overview of the history of cannabis use in medicine, cannabinoid signaling pathways, and current data from preclinical as well as clinical studies on using cannabinoids as potential analgesic agents. Clinical and experimental studies show that cannabis-derived compounds act as anti-emetic, appetite modulating and analgesic agents. However, the efficacy of individual products is variable and dependent upon the route of administration. Since opioids are the only therapy for severe pain, analgesic ability of cannabinoids may provide a much-needed alternative to opioids. Moreover, cannabinoids act synergistically with opioids and act as opioid sparing agents, allowing lower doses and fewer side effects from chronic opioid therapy. Thus, rational use of cannabis based medications deserves serious consideration to alleviate the suffering of patients due to severe pain. PMID:20073408

  8. Photovoltaic energy potential of Quebec

    International Nuclear Information System (INIS)

    Royer, J.; Thomas, R.

    1993-01-01

    Results are presented from a study concerning the potential of photovoltaic (PV) energy in Quebec to the year 2010. The different PV applications which are or will be economically viable in Quebec for the study period are identified and evaluated in comparison with the conventional energy sources used for these applications. Two penetration scenarios are proposed. One considers little change at the level of policies established for commercialization of PV sources, and the other considers certain measures which accelerate the implementation of PV technology in certain niches. While the off-grid market is already motivated to adopt PV technology for economic reasons, it is forecast that all encouragement from lowering costs would accelerate PV sales, offering a larger purchasing power to all interested parties. Above all, lowered PV costs would open up the network market. Photovoltaics would have access to a much larger market, which will accelerate changes in the very nature of the industry and bring with it new reductions in the costs of producing PV systems. 5 refs., 1 fig., 7 tabs

  9. Theoretical study on optical model potential

    International Nuclear Information System (INIS)

    Lim Hung Gi.

    1984-08-01

    The optical model potential of non-local effect on the rounded edge of the potential is derived. On the basis of this potential the functional form of the optical model potential, the energy dependence and relationship of its parameters, and the dependency of the values of the parameters on energy change are shown in this paper. (author)

  10. Beautiful, but also potentially invasive

    Directory of Open Access Journals (Sweden)

    Lipták Boris

    2015-03-01

    Full Text Available Introduction of non-indigenous exotic species to new areas, where they may establish viable populations and become invasive, is a considerable problem in the protection of nature worldwide, as these species may alter the indigenous species population structure and potentially even decrease the biodiversity. The European fauna underwent through major negative changes on the continent and nowadays, it experiences another new treat, represented by the expanding aquarium pet trade, and with it, associated species (and disease introductions. Exotic freshwater crustaceans are one of the taxa widely incorporated in the business, counting a remarkable number of species. Recent records of the exotic marbled crayfish or Marmorkrebs (Procambarus fallax f. virginalis in German in open ecosystems in Slovakia pointed to human-mediated introductions associated with aquarium pet trade in the country. In this regard, a study of the aquarium pet trade both in expositions and shops and online was assessed. Several crustacean taxa are available both in pet trade exhibitions and online through the Internet. Altogether 26 different species were identified in the aquarium trade in Slovakia. These are Procambarus fallax f. virginalis, P. clarkii, P. alleni, Cherax quadricarinatus, C. destructor, C. holthuisi, C. peknyi, Cambarellus patzcuarensis and C. diminutus occurring in the aquarium pet trade in Slovakia (n = 9. Procambarus fallax f. virginalis, P. clarkii and C. patzuarensis are the most common in this regard. There is also a quantity of other related taxa in the aquarium pet trade in Slovakia, mainly Caridina spp. (n = 5, Neocaridina spp. (n = 4, Atyopsis moluccensis, Atya gabonensis, Arachnochium kulsiense and several taxa of exotic crabs (n = 5 belonging to three different genera (Cardiosoma, Geosesarma and Gecarinus present. Neocaridina davidi is identified as the most frequent in this regard. As some of the species can become established and form viable

  11. Integrative Potential of Architectural Activities

    Science.gov (United States)

    Davydova, O. V.

    2017-11-01

    The architectural activity integrative potential is considered through the combination as well as the organization of necessary universal human and professional, artificial and natural, social and individual architectural activities in the multidimensional unity of its components reflecting and influencing the public thinking with the artistic-figurative language of international communication using experimental form-building, interactive presentations, theatrical and gaming expressiveness to organize an easier contact with the consumer, methods of design and advertising. The methodology is used to reflect the mutual influence of personal and social problems through globalization and identification of their problem in the public, to study the existing methods of the problem solving, to analyze their effectiveness, to search for actual problems and new solutions to them using the latest achievements of technological progress, artistic patterns, creation of a holistic architectural image reflecting the author’s worldview in the general picture of the modern world with its inherent tendencies “Surah” and “entertainment”. The operative communication means in the chain of social experience are developed - the teacher - the trainee - the new educational result used to transmit the updated information in a generalized form, the current and final control through the use of feedback sheets, supporting summaries, info cards, its decisions. The paper considers the study time efficiency due to the organization of the research activity which allows students to obtain a theoretical generalized information (the creator’s limitation) in the process of filling or compiling informative and diagnostic maps that provide the theoretical framework for the creative activity through gaming activity that turns into a work activity which has a diagnosed result.

  12. A potential human hepatocellular carcinoma inhibitor from Bauhinia purpurea L. seeds: from purification to mechanism exploration.

    Science.gov (United States)

    Fang, Evandro Fei; Bah, Clara Shui Fern; Wong, Jack Ho; Pan, Wen Liang; Chan, Yau Sang; Ye, Xiu Juan; Ng, Tzi Bun

    2012-02-01

    A 20-kDa Kunitz-type trypsin-chymotrypsin inhibitor, Bauhinia purpurea trypsin inhibitor (BPLTI), has been isolated from the seeds of B. purpurea L. by using liquid chromatography procedures that involved ion exchange chromatography on Sp-Sepharose and Mono S and gel filtration on Superdex 75. BPLTI demonstrated protease inhibitory activities of 7226 BAEE units/mg and 65 BTEE units/mg toward trypsin and α-chymotrypsin, respectively. BPLTI was relatively thermal (0-60°C) and pH (3-10) stable and its activity could be decreased by dithiothreitol treatment. BPLTI exhibited a wide spectrum of anti-proliferative and pro-apoptotic activities especially on human hepatocellular carcinoma Hep G2 cells. However, it was devoid of a significant antiproliferative effect on immortal human hepatic WRL 68 cells. We show here that BPLTI stimulates apoptosis in Hep G2 cells, including (1) evoking DNA damage including the production of chromatin condensation and apoptotic bodies; (2) induction of cell apoptosis/necrosis; (3) mitochondrial membrane depolarization; and (4) increasing the production of cytokines. Taken together, our findings show for the first time that purified protease inhibitor from B. purpurea L. seeds is a promising candidate for the treatment of human hepatocellular carcinoma.

  13. Potential wine ageing during transportation

    Directory of Open Access Journals (Sweden)

    Jung Rainer

    2014-01-01

    Full Text Available In a global world, wineries have to satisfy the demand of consumers who wish to drink high quality wines from countries all over the world. To fulfill this request wines have to be transported, crossing thereby great distances from the place of production to the consumer country. At the Institute of Enology of Hochschule Geisenheim University examinations with White-, Rosé- and Red-Wines of different origins which had been transported over longer distances within Europe (Portugal, France, Italy to Germany by trucks were carried out. Shipping of wines was simulated in a climatized cabinet to analyze the influence on wine quality during this way and conditions of transportation. Time and temperature profiles were based on real transport situtations which were recorded during shipping from Germany to Japan using data loggers. White, Rosé and Red wines were transported during 6 to 8 weeks and then were analytically and sensorically compared to those which were stored at a constant temperature of 15 ∘C. Besides the effect of temperature, the movements and vibrations encountered by the wines were also examined. Analytically wines were analyzed for general analytical parameters with Fourier-Transformation-Infrared-Spectroscopie (FTIR, Colour differences (Spectralphotometrie and free and total sulfuric acid with Flow-Injection-Analysis (FIA. Sensory examinations with a trained panel were performed in difference tests in form of rankings and triangular tests. Summarizing the results from the different tests it could be found that transportation had an influence on the potential ageing of wines depending on the wine matrix. Especially high and varying temperatures during transportations over a longer distance and time had negative influences on wine quality. Also the movement of wine at higher temperatures had showed a negative effect whereas transport at cool temperatures even below 0 ∘C did not influence wine characteristics. Sophisticated

  14. The potential of electric vehicles

    International Nuclear Information System (INIS)

    2016-04-01

    Electric vehicles can help reduce the dependence of road transport on imported oil, cut the country's energy bill, reduce greenhouse gas emissions, improve air quality in cities through zero exhaust emissions and reduce noise pollution. The economic costs and environmental impacts of electric vehicles are mostly concentrated at the manufacturing stage, whereas the costs and impacts of internal combustion vehicles are predominantly felt during usage. So we cannot simply compare vehicles as objects, we must see how they are used, which means taking a fresh look at the full potential of electric vehicles which must be used intensely to be economically and environmentally viable. The main advantage of internal combustion vehicles is their ability to carry a very large amount of energy giving them a very large range and significant versatility. However, the consequences of the use of fossil fuels on the climate and the environment today require us to look for other solutions for vehicles and mobility systems. Electric vehicles are among these: its lack of versatility, due to its still limited range, is offset by being more adaptable and optimised for the usage sought. Electric vehicles are particularly suitable for new mobility services offerings and allow the transition to new ways of travelling to be speeded up optimising the use of the vehicle and no longer requiring ownership of it. The use of digital, facilitated by the electrical engine, opens up numerous opportunities for innovations and new services (such as the autonomous vehicle for example). In addition, electric vehicles can do more than just transport. Their batteries provide useful energy storage capabilities that can help regulate the power grid and the development of renewable energy. The marketing of electric vehicles may be accompanied by energy services that can be economically viable and used to structure the electro-mobility offer in return. To minimise the impact on the electrical grid, it is

  15. Square well approximation to the optical potential

    International Nuclear Information System (INIS)

    Jain, A.K.; Gupta, M.C.; Marwadi, P.R.

    1976-01-01

    Approximations for obtaining T-matrix elements for a sum of several potentials in terms of T-matrices for individual potentials are studied. Based on model calculations for S-wave for a sum of two separable non-local potentials of Yukawa type form factors and a sum of two delta function potentials, it is shown that the T-matrix for a sum of several potentials can be approximated satisfactorily over all the energy regions by the sum of T-matrices for individual potentials. Based on this, an approximate method for finding T-matrix for any local potential by approximating it by a sum of suitable number of square wells is presented. This provides an interesting way to calculate the T-matrix for any arbitary potential in terms of Bessel functions to a good degree of accuracy. The method is applied to the Saxon-Wood potentials and good agreement with exact results is found. (author)

  16. Exploring the potential of MAR

    International Nuclear Information System (INIS)

    Vanderzalm, Joanne

    2014-01-01

    Despite numerous benefits, the full potential for uptake of MAR for use of treated wastewater and urban stormwater has not been realised. CSIRO is currently leading research to address some of the major impediments to uptake of MAR. These include the clogging of the soil or aquifer matrix, leading to reduced infiltration rates; water quality impacts on the receiving aquifer; and uncertainty regarding the economics of MAR schemes. Field-scale application of MAR through national demonstration projects aims to reduce the uncertainty associated with technical and economic feasibility and facilitate water recycling via the aquifer. Current research in the Managed Aquifer Recharge and Recycling Options (MARRO) project provides two case studies using novel infiltration techniques, soil aquifer treatment (SAT) and infiltration galleries, to recharge treated wastewater for non-potable use. SAT at Alice Springs supplements existing groundwater resources for future irrigation supplies, while an infiltration gallery at Floreat (Western Australia) is evaluating the potential of MAR to sustain groundwater-fed wetlands. These infiltration techniques provide an opportunity to optimise the passive treatment processes and minimise water quality impacts on the receiving groundwater. SAT uses open infiltration basins operated intermittently to create alternate wet and dry cycles and optimise natural treatment processes within the subsurface. Power and Water Corporation's Alice Springs SAT scheme has been in operation since 2008 to prevent overflow of treated wastewater to surface water systems and augment the groundwater resource. Wastewater for recharge to a Quaternary sand and gravel aquifer is treated by stabilisation ponds and dissolved air flotation, with filtration added to the treatment train in late 2013. The scheme commenced as four basins with a total recharge area of 7,640 sq.m, but was increased to allow 600,000 m 3 /year recharge to the current, larger capacity of

  17. Scalar potentials and the Dirac equation

    International Nuclear Information System (INIS)

    Bergerhoff, B.; Soff, G.

    1994-01-01

    The Dirac equation is solved for various types of scalar potentials. Energy eigenvalues and normalized bound-state wave functions are calculated analytically for a scalar 1/r-potential as well as for a mixed scalar and Coulomb 1/r-potential. Also continuum wave functions for positive and negative energies are derived. Similarly, we investigate the solutions of the Dirac equation for a scalar square-well potential. Relativistic wave functions for scalar Yukawa and exponential potentials are determined numerically. Finally, we also discuss solutions of the Dirac equation for scalar linear and quadratic potentials which are frequently used to simulate quark confinement. (orig.)

  18. Synthesis, Characterization and DNA Cleavage of Copper(II ...

    African Journals Online (AJOL)

    Purpose: To study deoxyribonucleic acid (DNA) shearing capability of copper(II) complex of dithiothreitol (DTT) and to fevaluate its potential application in cancer therapy. Methods: A parrot green complex was synthesized by grinding copper acetate monohydrate and DTT in 1:2 molar ratio in a mortar until no fumes of acetic ...

  19. Green roofs: potential at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Elena M [Los Alamos National Laboratory

    2009-01-01

    strokes, heat exhaustion, and pollution that can agitate the respiratory system. The most significant savings associated with green roofs is in the reduction of cooling demands due to the green roof's thermal mass and their insulating properties. Unlike a conventional roof system, a green roof does not absorb solar radiation and transfer that heat into the interior of a building. Instead the vegetation acts as a shade barrier and stabilizes the roof temperature so that interior temperatures remain comfortable for the occupants. Consequently there is less of a demand for air conditioning, and thus less money spent on energy. At LANL the potential of green roof systems has already been realized with the construction of the accessible green roof on the Otowi building. To further explore the possibilities and prospective benefits of green roofs though, the initial capital costs must be invested. Three buildings, TA-03-1698, TA-03-0502, and TA-53-0031 have all been identified as sound candidates for a green roof retrofit project. It is recommended that LANL proceed with further analysis of these projects and implementation of the green roofs. Furthermore, it is recommended that an urban forestry program be initiated to provide supplemental support to the environmental goals of green roofs. The obstacles barring green roof construction are most often budgetary and structural concerns. Given proper resources, however, the engineers and design professionals at LANL would surely succeed in the proper implementation of green roof systems so as to optimize their ecological and monetary benefits for the entire organization.

  20. Supersymmetric approach for Killingbeck radial potential plus noncentral potential in Schrodinger equation

    International Nuclear Information System (INIS)

    Cari, C.; Suparmi, A.; Yunianto, M.; Pratiwi, B. N.

    2016-01-01

    Killingbeck radial potential, which consists of harmonic oscillator, linier and Coulomb potentials, is combined with non-central potential. The solution of three dimensional Schrodinger equation for Killingbeck potential is combined with Poschl-Teller potential and Symmetrical Top non-central potentials are investigated using supersymmetry (SUSY) operator. The non-relativistic energy is obtained which is infuenced by potentials and the wave functions are produced by using SUSY operator. (paper)

  1. Supersymmetric quantum mechanics and new potentials

    International Nuclear Information System (INIS)

    Drigo Filho, E.

    1988-01-01

    Using the supersymmetric quantum mechanics the following potential are generalized. The particle in the box, Poeschl-Teller and Rosen-Morse. The new potentials are evaluated and their eigenfunctions and spectra are indicated. (author) [pt

  2. Dual Eligibles and Potentially Avoidable Hospitalizations

    Data.gov (United States)

    U.S. Department of Health & Human Services — About 25 percent of the hospitalizations for dual eligible beneficiaries in 2005 were potentially avoidable. Medicare and Medicaid spending for those potentially...

  3. Deforming tachyon kinks and tachyon potentials

    International Nuclear Information System (INIS)

    Afonso, Victor I.; Bazeia, Dionisio; Brito, Francisco A.

    2006-01-01

    In this paper we investigate deformation of tachyon potentials and tachyon kink solutions. We consider the deformation of a DBI type action with gauge and tachyon fields living on D1-brane and D3-brane world-volume. We deform tachyon potentials to get other consistent tachyon potentials by using properly a deformation function depending on the gauge field components. Resolutions of singular tachyon kinks via deformation and applications of deformed tachyon potentials to scalar cosmology scenario are discussed

  4. Exactly solvable energy-dependent potentials

    International Nuclear Information System (INIS)

    Garcia-Martinez, J.; Garcia-Ravelo, J.; Pena, J.J.; Schulze-Halberg, A.

    2009-01-01

    We introduce a method for constructing exactly-solvable Schroedinger equations with energy-dependent potentials. Our method is based on converting a general linear differential equation of second order into a Schroedinger equation with energy-dependent potential. Particular examples presented here include harmonic oscillator, Coulomb and Morse potentials with various types of energy dependence.

  5. Classification of geothermal resources by potential

    Science.gov (United States)

    Rybach, L.

    2015-03-01

    When considering and reporting resources, the term "geothermal potential" is often used without clearly stating what kind of potential is meant. For renewable energy resources it is nowadays common to use different potentials: theoretical, technical, economic, sustainable, developable - decreasing successively in size. In such a sequence, the potentials are progressively realizable and more and more rewarding financially. The theoretical potential describes the physically present energy, the technical potential the fraction of this energy that can be used by currently available technology and the economic potential the time- and location-dependent fraction of the previous category; the sustainable potential constrains the fraction of the economic potential that can be utilized in the long term; the developable potential is the fraction of the economic resource which can be developed under realistic conditions. In converting theoretical to technical potential, the recovery factor (the ratio extractable heat/heat present at depth) is of key importance. An example (global geothermal resources) is given, with numerical values of the various potentials. The proposed classification could and should be used as a kind of general template for future geothermal energy resources reporting.

  6. Effective pair potentials for spherical nanoparticles

    International Nuclear Information System (INIS)

    Van Zon, Ramses

    2009-01-01

    An effective description for rigid spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, as can occur for some forms of the pair potentials, the effective potential generally has non-analytic points. It is shown that for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Even when only non-overlapping situations are possible, the auxiliary potentials facilitate the formulation of the effective potentials. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered and shown to be related to those for solid nanoparticles. For hollow nanoparticles overlap is more physical, since this covers the case of a smaller particle embedded in a larger, hollow nanoparticle. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London–van der Waals, Morse, Buckingham, and Lennard-Jones potentials. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure

  7. The Anthropology of Potentiality in Biomedicine

    DEFF Research Database (Denmark)

    Taussig, Karen-Sue; Hoeyer, Klaus; Helmreich, Stefan

    2013-01-01

    with potential. We suggest that anthropologists of the life sciences and biomedicine should work reflexively with the concept of potentiality and the politics of its naming and framing. We lay out a set of propositions and emphasize the moral aspects of claims about potentiality as well as the productivity...

  8. Dynamic polarization potentials in heavy ion scattering

    International Nuclear Information System (INIS)

    Wolf, R.

    1984-01-01

    In this thesis the polarization potential is calculated which is caused by several collective, strongly coupled states. In the framework of the considered model space the calculation of the polarization potential was exact, i.e. no approximations were made. For this purpose the Green function of the system had to be calculated. This led to a nonlocal polarization potential. For the better interpretation possibility and for the easier use in coupled-channel or optical-model calculations from the nonlocal potentials also equivalent potentials were constructed. The properties of the local and nonlocal potentials as shape, angular momentum, and energy dependence were discussed. Furthermore parametrizations were given, how polarization effects can be regarded in a simple way in optical-model or coupled-channel calculations. The calculations were performed for the systems 12 C+ 12 C and 16 O+ 16 O. To meet as realistic results as possible, parameters for the unperturbed potential were looked for which describe as many data as possible, like angular distributions, excitation functions, and alignment of the main channels. As unperturbed potential both folding potentials and phenomenological potentials were applied in order to study the differences in the polarization potential in the application of deep and flat potentials. (orig./HSI) [de

  9. The electromagnetic potentials without the gauge transformations

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Augusto; Chubykalo, Andrey; Rodriguez, Alejandro Gutierrez; Hernandez, Maria de los Angeles [Universidad Autonoma de Zacatecas (Mexico). Unidad Academica de Fisica

    2011-07-01

    In this note we show that the use of the Helmholtz theorem lead to derivation of uniquely determined electromagnetic potentials without making use of the gauge transformation. These potentials correspond to the potentials obtained by imposing so-called Coulomb condition (gauge) in the traditional approach. We show that the electromagnetic field comprises two components, one of which is characterized by its instantaneous action at a distance, whereas another one propagates in the retarded form with the velocity of light. One of the theoretical consequences of this new definition is that the electromagnetic potentials are real physical quantities as well as the electric and magnetic fields. We show that the reality of the electromagnetic potentials in quantum-mechanics is also a property of these potentials in the classical electrodynamics. Equations for potentials obtained in our approach are already separated with respect to vector and scalar potentials, so there is no necessity in using the gauge transformations and, accordingly, in making use of either Lorentz or Coulomb condition. The vector potential and scalar potential introduced thus are uniquely defined. The scalar potential is a generator of the so called instantaneous action at a distance, whereas the solenoidal vector potential can propagate with the velocity of light and it is responsible for the retarded action of the electromagnetic field. (author)

  10. Potential and profile experiments in MM-4

    International Nuclear Information System (INIS)

    Tian Zhongyu; Ming Linzhou; Feng Xiaozhen; Feng Chuntang; Yin Youjun; Liu Yuhua; Wang Jihai

    1988-01-01

    Experimental results in MM-4 are presented. These results show that there were double potential wells and double ion temperatures in the plasma. The mechanism giving rise to such potential profiles can be attributed to the Stormer region in the cusp system and the different operation regimes of the electron gun used. The measured plasma potential was about - 200 - 300V

  11. Iterated interactions method. Realistic NN potential

    International Nuclear Information System (INIS)

    Gorbatov, A.M.; Skopich, V.L.; Kolganova, E.A.

    1991-01-01

    The method of iterated potential is tested in the case of realistic fermionic systems. As a base for comparison calculations of the 16 O system (using various versions of realistic NN potentials) by means of the angular potential-function method as well as operators of pairing correlation were used. The convergence of genealogical series is studied for the central Malfliet-Tjon potential. In addition the mathematical technique of microscopical calculations is improved: new equations for correlators in odd states are suggested and the technique of leading terms was applied for the first time to calculations of heavy p-shell nuclei in the basis of angular potential functions

  12. Conduction velocity of antigravity muscle action potentials.

    Science.gov (United States)

    Christova, L; Kosarov, D; Christova, P

    1992-01-01

    The conduction velocity of the impulses along the muscle fibers is one of the parameters of the extraterritorial potentials of the motor units allowing for the evaluation of the functional state of the muscles. There are no data about the conduction velocities of antigravity muscleaction potentials. In this paper we offer a method for measuring conduction velocity of potentials of single MUs and the averaged potentials of the interference electromiogram (IEMG) lead-off by surface electrodes from mm. sternocleidomastoideus, trapezius, deltoideus (caput laterale) and vastus medialis. The measured mean values of the conduction velocity of antigravity muscles potentials can be used for testing the functional state of the muscles.

  13. Remote RemoteRemoteRemote sensing potential for sensing ...

    African Journals Online (AJOL)

    Remote RemoteRemoteRemote sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing potential for sensing p. A Ngie, F Ahmed, K Abutaleb ...

  14. Calculation of baryon chemical potential and strangeness chemical potential in resonance matter

    International Nuclear Information System (INIS)

    Fu Yuanyong; Hu Shouyang; Lu Zhongdao

    2006-01-01

    Based on the high energy heavy-ion collisions statistical model, the baryon chemical potential and strangeness chemical potential are calculated for resonance matter with net baryon density and net strangeness density under given temperature. Furthermore, the relationship between net baryon density, net strangeness density and baryon chemical potential, strangeness chemical potential are analyzed. The results show that baryon chemical potential and strangeness chemical potential increase with net baryon density and net strangeness density increasing, the change of net baryon density affects baryon chemical potential and strangeness chemical potential more strongly than the change of net strangeness density. (authors)

  15. Indoor radon risk potential of Hawaii

    International Nuclear Information System (INIS)

    Reimer, G.M.; Szarzi, S.L.

    2005-01-01

    A comprehensive evaluation of radon risk potential in the State of Hawaii indicates that the potential for Hawaii is low. Using a combination of factors including geology, soils, source-rock type, soil-gas radon concentrations, and indoor measurements throughout the state, a general model was developed that permits prediction for various regions in Hawaii. For the nearly 3,100 counties in the coterminous U.S., National Uranium Resource Evaluation (NURE) aerorad data was the primary input factor. However, NURE aerorad data was not collected in Hawaii, therefore, this study used geology and soil type as the primary and secondary components of potential prediction. Although the radon potential of some Hawaiian soils suggests moderate risk, most houses are built above ground level and the radon soil potential is effectively decoupled from the house. Only underground facilities or those with closed or recirculating ventilation systems might have elevated radon potential. (author)

  16. Research potential and cognitive features of students.

    Directory of Open Access Journals (Sweden)

    Bordovskaia N.V.

    2014-12-01

    Full Text Available This article examines the theoretical and methodological justifications for studying students’ research potential. It presents proof of the isomorphic nature of human research activity and research potential as well as of the fluid nature of its development: from research-like behavior to science-based research activity. It defines three functional components (motivational, cognitive, and behavioral that form the structure of research potential. It further presents the results of empirically studying the cognitive features of master’s students possessing different levels of research potential. It provides data on the dynamics of research-potential components at different educational levels (bachelor’s and master’s programs. Special attention is given to a comparative analysis of evaluations by research tutors regarding their students’ research potential and of the indicators obtained using psychodiagnostic methods.

  17. Enterprise Potential: Essence, Classification and Types

    Directory of Open Access Journals (Sweden)

    Turylo Anatolii M.

    2014-02-01

    Full Text Available The article considers existing approaches to classification of the enterprise potential as an economic notion. It offers own vision of classification of enterprise potential, which meets modern tendencies of enterprise development. Classification ensures a possibility of a wider description and assessment of enterprise potential and also allows identification of its most significant characteristics. Classification of the enterprise potential is developed by different criteria: by functions, by resource support, by ability to adapt, by the level of detection, by the spectrum of taking into account possibilities, by the period of coverage of possibilities and by the level of use. Analysis of components of the enterprise potential allows obtaining a complete and trustworthy assessment of the state of an enterprise. Adaptation potential of an enterprise is based on principles systemacy and dynamism, it characterises possibilities of adjustment of an enterprise to external and internal economic conditions.

  18. On transparent potentials: a Born approximation study

    International Nuclear Information System (INIS)

    Coudray, C.

    1980-01-01

    In the frame of the scattering inverse problem at fixed energy, a class of potentials transparent in Born approximation is obtained. All these potentials are spherically symmetric and are oscillating functions of the reduced radial variable. Amongst them, the Born approximation of the transparent potential of the Newton-Sabatier method is found. In the same class, quasi-transparent potentials are exhibited. Very general features of potentials transparent in Born approximation are then stated. And bounds are given for the exact scattering amplitudes corresponding to most of the potentials previously exhibited. These bounds, obtained at fixed energy, and for large values of the angular momentum, are found to be independent on the energy

  19. A parabolic model for dimple potentials

    International Nuclear Information System (INIS)

    Aydin, Melike Cibik; Uncu, Haydar; Deniz, Coskun

    2013-01-01

    We study the truncated parabolic function and demonstrate that it is a representation of the Dirac δ function. We also show that the truncated parabolic function, used as a potential in the Schrödinger equation, has the same bound state spectrum, tunneling and reflection amplitudes as the Dirac δ potential, as the width of the parabola approximates to zero. Dirac δ potential is used to model dimple potentials which are utilized to increase the phase-space density of a Bose–Einstein condensate in a harmonic trap. We show that a harmonic trap with a δ function at the origin is a limiting case of the harmonic trap with a symmetric truncated parabolic potential around the origin. Hence, the truncated parabolic is a better candidate for modeling the dimple potentials. (paper)

  20. Electrode breakdown potentials in MHD plasmas

    International Nuclear Information System (INIS)

    Sodha, M.S.; Raju, G.V.R.; Kumar, A.S.; Gupta, Bhumesh

    1988-01-01

    Electrode breakdown potentials and current densities have been calculated for both the thermionically electron emitting and non-emitting cathodes. Calculated values have been compared with the available experimental results. It is found that the cathode potential drop for the breakdown is almost unaffected by the emission. However, both the total potential difference between the anode and the cathode and the current density at the breakdown are higher for electron-emitting cathodes than for non-emitting cathodes. (author)

  1. Dynamical equations for the optical potential

    International Nuclear Information System (INIS)

    Kowalski, K.L.

    1981-01-01

    Dynamical equations for the optical potential are obtained starting from a wide class of N-particle equations. This is done with arbitrary multiparticle interactions to allow adaptation to few-body models of nuclear reactions and including all effects of nucleon identity. Earlier forms of the optical potential equations are obtained as special cases. Particular emphasis is placed upon obtaining dynamical equations for the optical potential from the equations of Kouri, Levin, and Tobocman including all effects of particle identity

  2. Potential radiation doses from 1994 Hanford Operations

    Energy Technology Data Exchange (ETDEWEB)

    Soldat, J.K.; Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the potential radiation doses to the public from releases originating at the Hanford Site. Members of the public are potentially exposed to low-levels of radiation from these effluents through a variety of pathways. The potential radiation doses to the public were calculated for the hypothetical MEI and for the general public residing within 80 km (50 mi) of the Hanford Site.

  3. Actual and Potential Electoral Absenteeism in Belgium

    OpenAIRE

    ACKAERT, Johan; DUMONT, P.; DE WINTER, L.

    2007-01-01

    During the eighties and nineties of the 20th century, absenteeism increased in Belgium. This evolution ended for all types of elections at the beginning of the current century. This paper offered a number of potential explanations for this puzzle, but we acknowledge that further examination is necessary to provide a clear answer for this change. We showed that potential absenteeists share specific characteristics. Potential turnout (in case of abolishment of compulsory voting) ...

  4. Verification of the SLC wake potentials

    International Nuclear Information System (INIS)

    Bane, K.; Weiland, T.

    1983-01-01

    The accurate knowledge of the monopole, dipole, and quadrupole wake potentials is essential for SLC. These wake potentials were previously computed by the modal method. The time domain code TBCI allows independent verification of these results. This comparison shows that the two methods agree to within 10% for bunch lengths down to 1 mm. TBCI results also indicate that rounding the irises gives at least a 10% reduction in the wake potentials

  5. Interatomic potentials for materials of nuclear interest

    International Nuclear Information System (INIS)

    Fernandez, Julian R.; Monti, Ana M.; Pasianot, Roberto C.; Simonelli, G.

    2007-01-01

    Procedures to develop embedded atom method (EAM) interatomic potentials are described, with foreseeable applications in nuclear materials. Their reliability is shown by evaluating relevant properties. The studied materials are Nb, Zr and U. The first two were then used to develop an inter species potential for the Zr-Nb binary system. In this sense, the Fe-Cu system was also studied starting from Fe and Cu potentials extracted from the literature. (author) [es

  6. Standard Model Effective Potential from Trace Anomalies

    Directory of Open Access Journals (Sweden)

    Renata Jora

    2018-01-01

    Full Text Available By analogy with the low energy QCD effective linear sigma model, we construct a standard model effective potential based entirely on the requirement that the tree level and quantum level trace anomalies must be satisfied. We discuss a particular realization of this potential in connection with the Higgs boson mass and Higgs boson effective couplings to two photons and two gluons. We find that this kind of potential may describe well the known phenomenology of the Higgs boson.

  7. Potential radiation doses from 1994 Hanford Operations

    International Nuclear Information System (INIS)

    Soldat, J.K.; Antonio, E.J.

    1995-01-01

    This section of the 1994 Hanford Site Environmental Report summarizes the potential radiation doses to the public from releases originating at the Hanford Site. Members of the public are potentially exposed to low-levels of radiation from these effluents through a variety of pathways. The potential radiation doses to the public were calculated for the hypothetical MEI and for the general public residing within 80 km (50 mi) of the Hanford Site

  8. Pumped Storage and Potential Hydropower from Conduits

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-02-25

    Th is Congressional Report, Pumped Storage Hydropower and Potential Hydropower from Conduits, addresses the technical flexibility that existing pumped storage facilities can provide to support intermittent renewable energy generation. This study considered potential upgrades or retrofit of these facilities, the technical potential of existing and new pumped storage facilities to provide grid reliability benefits, and the range of conduit hydropower opportunities available in the United States.

  9. One parameter model potential for noble metals

    International Nuclear Information System (INIS)

    Idrees, M.; Khwaja, F.A.; Razmi, M.S.K.

    1981-08-01

    A phenomenological one parameter model potential which includes s-d hybridization and core-core exchange contributions is proposed for noble metals. A number of interesting properties like liquid metal resistivities, band gaps, thermoelectric powers and ion-ion interaction potentials are calculated for Cu, Ag and Au. The results obtained are in better agreement with experiment than the ones predicted by the other model potentials in the literature. (author)

  10. Disturbances of the sarcoplasmic reticulum and transverse tubular system in 24-h electrostimulated fast-twitch skeletal muscle

    DEFF Research Database (Denmark)

    Frías, J A; Cadefau, J A; Prats, C

    2005-01-01

    Chronic low-frequency stimulation of rabbit tibialis anterior muscle over a 24-h period induces a conspicuous loss of isometric tension that is unrelated to muscle energy metabolism (J.A. Cadefau, J. Parra, R. Cusso, G. Heine, D. Pette, Responses of fatigable and fatigue-resistant fibres of rabbit...... muscle to low-frequency stimulation, Pflugers Arch. 424 (1993) 529-537). To assess the involvement of sarcoplasmic reticulum and transverse tubular system in this force impairment, we isolated microsomal fractions from stimulated and control (contralateral, unstimulated) muscles on discontinuous sucrose...... of muscles stimulated for 24 h underwent acute changes in the pattern of protein bands. First, light fractions from longitudinal sarcoplasmic reticulum, enriched in Ca2+-ATPase activity, R1 and R2, were greatly reduced (67% and 51%, respectively); this reduction was reflected in protein yield of crude...

  11. A temporary decrease in twitch response during reversal of rocuronium-induced muscle relaxation with a small dose of sugammadex

    NARCIS (Netherlands)

    Eleveld, Douglas J.; Kuizenga, Karel; Proost, Johannes H.; Wierda, J. Mark K. H.

    BACKGROUND: We present a case in which a temporary decrease in train-of-four (TOF) response was observed after reversal of muscle relaxation with a small dose (0.5 mg/kg) of sugammadex administered 42 min after 0.9 mg/kg of rocuronium. At the end of the operation, the TOF ratio was > 0.9, and the

  12. Train-of-four ratio recovery often precedes twitch recovery when neuromuscular block is reversed by sugammadex

    NARCIS (Netherlands)

    Staals, L.M.; Driessen, J.J.; Egmond, J. van; Boer, H.D. de; Klimek, M.; Flockton, E.A.; Snoeck, M.M.J.

    2011-01-01

    BACKGROUND: Sugammadex reverses rocuronium-induced neuromuscular block (NMB). In all published studies investigating sugammadex, the primary outcome parameter was a train-of-four (TOF) ratio of 0.9. The recovery time of T1 was not described. This retrospective investigation describes the recovery of

  13. IGF-I treatment improves the functional properties of fast- and slow-twitch skeletal muscles from dystrophic mice.

    Science.gov (United States)

    Lynch, G S; Cuffe, S A; Plant, D R; Gregorevic, P

    2001-04-01

    Although insulin-like growth factor-I (IGF-I) has been proposed for use by patients suffering from muscle wasting conditions, few studies have investigated the functional properties of dystrophic skeletal muscle following IGF-I treatment. 129P1 ReJ-Lama2(dy) (129 ReJ dy/dy) dystrophic mice suffer from a deficiency in the structural protein, laminin, and exhibit severe muscle wasting and weakness. We tested the hypothesis that 4 weeks of IGF-I treatment ( approximately 2 mg/kg body mass, 50 g/h via mini-osmotic pump, subcutaneously) would increase the mass and force producing capacity of skeletal muscles from dystrophic mice. IGF-I treatment increased the mass of the extensor digitorum longus (EDL) and soleus muscles of dystrophic mice by 20 and 29%, respectively, compared with untreated dystrophic mice (administered saline-vehicle only). Absolute maximum force (P(o)) of the EDL and soleus muscle was increased by 40 and 32%, respectively, following IGF-I treatment. Specific P(o) (sP(o)) was increased by 23% in the EDL muscles of treated compared with untreated mice, but in the soleus muscle sP(o) was unchanged. IGF-I treatment increased the proportion of type IIB and type IIA fibres and decreased the proportion of type I fibres in the EDL muscles of dystrophic mice. In the soleus muscles of dystrophic mice, IGF-I treatment increased the proportion of type IIA fibres and decreased the proportion of type I fibres. Average fibre cross-sectional area was increased in the EDL and soleus muscles of treated compared with untreated mice. We conclude that IGF-I treatment ameliorates muscle wasting and improves the functional properties of skeletal muscles of dystrophic mice. The findings have important implications for the role of IGF-I in ameliorating muscle wasting associated with the muscular dystrophies.

  14. Nandrolone decanoate treatment affects sarcoplasmic reticulum Ca(2+) ATPase function in skinned rat slow- and fast-twitch fibres.

    Science.gov (United States)

    Bouhlel, Aicha; Joumaa, Wissam H; Léoty, Claude

    2003-09-01

    The effects of anabolic-androgenic steroid administration on the function of the sarcoplasmic reticulum (SR) pump were investigated in chemically skinned fibres from the extensor digitorum longus (EDL) and soleus muscles of sedentary rats. Twenty male rats were divided into two groups, one group received an intramuscular injection of nandrolone decanoate (15 mg x kg(-1)) weekly for 8 weeks, the second received similar weekly doses of vehicle (sterile peanut oil). Compared with control muscles, nandrolone decanoate treatment reduced SR Ca(2+) loading in EDL and soleus fibres by 49% and 29%, respectively. In control and treated muscles, the rate of Ca(2+) leakage depended on the quantity of Ca(2+) loaded. Furthermore, for similar SR Ca(2+) contents, the Ca(2+) leakage rate was not significantly modified by nandrolone decanoate treatment. Nandrolone decanoate treatment thus affects Ca (2+) uptake by the SR in a fibre-type dependent manner.

  15. Influence of N-acetylcysteine on oxidative stress in slow-twitch soleus muscle of heart failure rats

    OpenAIRE

    Martinez, Paula Felippe [UNESP; Bonomo, Camila [UNESP; Guizoni, Daniele Mendes [UNESP; Oliveira Junior, Silvio Assis [UNESP; Damatto, Ricardo Luiz [UNESP; Cezar, Marcelo Diarcadia Mariano [UNESP; Lima, Aline Regina Ruiz [UNESP; Pagan, Luana Urbano [UNESP; Seiva, Fabio Rodrigues; Fernandes, Denise Castro; Laurindo, Francisco Rafael Martins; Novelli, Ethel Lourenzi Barbosa [UNESP; Matsubara, Luiz Shiguero [UNESP; Zornoff, Leonardo Antonio Mamede [UNESP; Okoshi, Katashi [UNESP

    2015-01-01

    Background: Chronic heart failure is characterized by decreased exercise capacity with early exacerbation of fatigue and dyspnea. Intrinsic skeletal muscle abnormalities can play a role in exercise intolerance. Causal or contributing factors responsible for muscle alterations have not been completely defined. This study evaluated skeletal muscle oxidative stress and NADPH oxidase activity in rats with myocardial infarction (MI) induced heart failure. Methods and Results: Four months after MI,...

  16. Actions of lyotropic anions on the mechanical properties of fast and slow twitch rat muscles at different temperatures

    Czech Academy of Sciences Publication Activity Database

    Wondmikun, Y.; Soukup, Tomáš; Asmussen, G.

    2003-01-01

    Roč. 52, č. 1 (2003), s. 123-129 ISSN 0862-8408 R&D Projects: GA ČR GA304/00/1653 Grant - others:Deutsche Forschungsgemeinschaft(DE) -; Schwerpunkt Muskelforschung(DE) As 74/1-2 Institutional research plan: CEZ:AV0Z5011922 Keywords : slow and fast muscles * contractile properties * lyotropic anions Subject RIV: FH - Neurology Impact factor: 0.939, year: 2003

  17. Characterization qualitative and potentialities of utilization of ...

    African Journals Online (AJOL)

    Characterization qualitative and potentialities of utilization of methacomposts of poultry in the nurseries aboveground. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN ... Journal of Fundamental and Applied Sciences.

  18. Measurement of human potential in organizations

    Directory of Open Access Journals (Sweden)

    Rosa María Fuchs Ángeles

    2015-09-01

    Full Text Available Companies around the world are concerned about talent management in their organizations. The concern is to retain talented employees and this may not be possible if they are not properly identified. Performance and potential evaluations become then important. Performance evaluations qualify the historical record of the employee, so their measurement is provided. However, measuring the potential performance assesses potential future charges, therefore it is not a simple task. In this paper, characteristics evaluated in potential employees and tools that are commonly used are presented. Also, the case of four companies operating in Peru is shown.

  19. On the generalized potential of inertial forces

    International Nuclear Information System (INIS)

    Siboni, S

    2009-01-01

    The generalized potential of the inertial forces acting on a holonomic system in an accelerated reference frame is derived in a way which admits a simple physical interpretation. It is shown that the generalized potential refers to all the inertial forces and, apart from the very special case of a uniformly rotating frame, it is impossible to distinguish a contribution to only the Coriolis force and a contribution pertaining to the residual, velocity-independent fictitious forces. Such an approach to the determination of the generalized potential of inertial forces may be helpful in introducing the topic of the generalized potential to advanced undergraduate and graduate students

  20. Geophysical Processes - MO 2013 Collapse Potential (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Collapse potential correlates with locations of underground mines and sinkholes. Computer-generated hazard calculations include areas in close proximity to mines and...

  1. An Introduction to LANL Mixed Potential Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brosha, Eric Lanich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kreller, Cortney [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-26

    These are slides for a webinar given on the topics of an introduction to LANL mixed potential sensors. Topics include the history of LANL electrochemical sensor work, an introduction to mixed potential sensors, LANL uniqueness, and an application of LANL mixed potential sensors. The summary is as follows: Improved understanding of the mixed-potential sensor mechanism (factors controlling the sensor response identified), sensor design optimized to maximize sensor sensitivity and durability (porous electrolyte/dense electrodes), electrodes selected for various specific applications (CO, HC, H2), sensor operating parameters optimized for improved gas selectivity (NOx, NH3).

  2. Aquifer Characterization and Groundwater Potential Assessment

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Keywords: Aquifer Characterization, Groundwater Potential, Electrical Resistivity, Lithologic Logs ... State Water Corporation currently cannot meet the daily water ... METHOD OF STUDY ... sections which were constrained with the available.

  3. The construction of partner potential from the general potential anharmonic in D-dimensional Schrodinger system

    Science.gov (United States)

    Suparmi; Cari, C.; Wea, K. N.; Wahyulianti

    2018-03-01

    The Schrodinger equation is the fundamental equation in quantum physics. The characteristic of the particle in physics potential field can be explained by using the Schrodinger equation. In this study, the solution of 4 dimensional Schrodinger equation for the anharmonic potential and the anharmonic partner potential have done. The method that used to solve the Schrodinger equation was the ansatz wave method, while to construction the partner potential was the supersymmetric method. The construction of partner potential used to explain the experiment result that cannot be explained by the original potential. The eigenvalue for anharmonic potential and the anharmonic partner potential have the same characteristic. Every increase of quantum orbital number the eigenvalue getting smaller. This result corresponds to Bohrn’s atomic theory that the eigenvalue is inversely proportional to the atomic shell. But the eigenvalue for the anharmonic partner potential higher than the eigenvalue for the anharmonic original potential.

  4. Unjamming in models with analytic pairwise potentials

    NARCIS (Netherlands)

    Kooij, S.; Lerner, E.

    Canonical models for studying the unjamming scenario in systems of soft repulsive particles assume pairwise potentials with a sharp cutoff in the interaction range. The sharp cutoff renders the potential nonanalytic but makes it possible to describe many properties of the solid in terms of the

  5. Algebraic approach to the Kratzer potential

    International Nuclear Information System (INIS)

    Setare, Mohammad R; Karimi, Ebrahim

    2007-01-01

    In this paper, the energy eigenvalues and the corresponding eigenfunctions are calculated for the Kratzer potential. Then we obtain the ladder operators for the one-dimensional (1D) and 3D Kratzer potential. Finally, we show that these operators satisfy the SU(2) commutation relation

  6. Developing simplified Regional Potential Evapotranspiration (PET ...

    African Journals Online (AJOL)

    Regional Potential Evapotranspiration (PET) estimation method was developed to estimate the potential evapotranspiration (reference evapotranspiration) over Abbay Basin as a function of basin maximum and minimum temperature, and modulated by site specific elevation data. The method is intended to estimate PET in ...

  7. Comparison of potentials for polymeric liquids

    International Nuclear Information System (INIS)

    Jung, Hae Young

    2002-01-01

    Many theories for polymeric liquids are based on the concepts of cell, hole, free volume of lattice etc. In this theories, van der Waals potential, Lennard-Jones 6-12 potential and their modified potentials are commonly used. In this work, Mie(p,6)potential was applied to the Continuous Lattice Fluid Theory (which extends the discrete lattices of Lattice Fluid Theory to classically continuous lattices) and Dee-Walsch's Cell Theory (which modifies Flory's Equation of State Theory). Both of them are known to be successful theories for polymeric liquids. Thus, PVT values changing with p (the exponent in the repulsion potential) were calculated and compared with experimental values. And, calculated values of Lattice Fluid theory, Flory's Equation of State Theory and Cho-Sanchez Theory using perturbation method were also compared. Through the calculated results, van der Waals potential, Lennard-Jones 6-12 potential and Mie(p,6) potential for polymeric liquids were compared with each other

  8. Potential biosurfactant producing endophytic and epiphytic fungi ...

    African Journals Online (AJOL)

    Potential biosurfactant producing endophytic and epiphytic fungi, isolated from macrophytes in the Negro River in Manaus, Amazonas, Brazil. ... Solms and Cyperus ligularis L., macrophytes collected from oil-contaminated waters, were studied to assess their potential for producing biosurfactants; the most promising ones ...

  9. A correction to the Watanabe potential

    International Nuclear Information System (INIS)

    Abul-Magd, A.Y.; Rabie, A.; El-Gazzar, M.A.

    1980-10-01

    Using the adiabatic approximation, an analytic expression for the correction to the Watanabe potential was obtained. In addition, we have corrected through a proper choice of the energy at which the potential parameters of the constituents of 6 Li should be taken. (author)

  10. Nuclear potentials due to pion exchange

    International Nuclear Information System (INIS)

    Robillota, M.R.

    1984-01-01

    The two, three and four nucleon potentials due to the exchange of pions can be accurately calculated by means of chiral symmetry. The comparison of the dynamical content of these potentials allow us to understand the geometrical origin of the hierarchy existing among them. (Author) [pt

  11. Potential roughness near lithographically fabricated atom chips

    DEFF Research Database (Denmark)

    Krüger, Peter; Andersson, L. M.; Wildermuth, Stefan

    2007-01-01

    Potential roughness has been reported to severely impair experiments in magnetic microtraps. We show that these obstacles can be overcome as we measure disorder potentials that are reduced by two orders of magnitude near lithographically patterned high-quality gold layers on semiconductor atom chip...

  12. Abelian gauge potentials on cubic lattices

    DEFF Research Database (Denmark)

    Burrello, M.; Lepori, L.; Paganelli, S.

    2017-01-01

    The study of the properties of quantum particles in a periodic potential subjected to a magnetic field is an active area of research both in physics and mathematics, and it has been and is yet deeply investigated. In this chapter we discuss how to implement and describe tunable Abelian magnetic...... potentials in one-dimensional rings....

  13. YouTube: Educational Potentials and Pitfalls

    Science.gov (United States)

    Jones, Troy; Cuthrell, Kristen

    2011-01-01

    The instructional potential of video technology in the classroom is promising, especially in light of the 21st Century Learning Framework (Siegle, 2009). Studies show positive gains in student outcomes as a result of the integration of video technology in instruction. This article explores potential uses of YouTube as an instructional aid in…

  14. Skin Potential as an Indicator of Emotion

    Science.gov (United States)

    Seligman, Linda

    1975-01-01

    The skin-potential responses of six college students were monitored while each was seen for 10 counseling sessions. Negative skin-potential responses were accompanied by feelings described as pleasant and released; positive responses were associated with unpleasant and inhibited feelings; and neutral responses were often associated with unpleasant…

  15. The unification of the nuclear optical potential

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The nuclear mean field is defined for bound and scattering states and its parameters shown to vary continuously over the whole energy range. The real and imaginary parts of the potential are connected by dispersion relations, and this unifies the potential from negative to positive energies. Recent analyses of experimental data using dispersion relations are reviewed. (author)

  16. Heavy quarkonium properties from Cornell potential using ...

    Indian Academy of Sciences (India)

    2016-10-08

    Oct 8, 2016 ... energy in the usual Schrödinger equation. This potential picture ... believe that it could be interesting to start from a more realistic wave function, ... is a technique that allows us to get isospectral potentials for the Schrödinger ...

  17. Identification of potentially competing Afrotropical and Palaearctic ...

    African Journals Online (AJOL)

    Identification of potentially competing Afrotropical and Palaearctic bird species in the Sahel. Jared M Wilson, Will RL Cresswell. Abstract. Areas experiencing a seasonal influx of migrants may be expected to have a high potential for competition between resident and migrant populations. Described differences in foraging ...

  18. Streaming potential near a rotating porous disk.

    Science.gov (United States)

    Prieve, Dennis C; Sides, Paul J

    2014-09-23

    Theory and experimental results for the streaming potential measured in the vicinity of a rotating porous disk-shaped sample are described. Rotation of the sample on its axis draws liquid into its face and casts it from the periphery. Advection within the sample engenders streaming current and streaming potential that are proportional to the zeta potential and the disk's major dimensions. When Darcy's law applies, the streaming potential is proportional to the square of the rotation at low rate but becomes invariant with rotation at high rate. The streaming potential is invariant with the sample's permeability at low rate and is proportional to the inverse square of the permeability at high rate. These predictions were tested by determining the zeta potential and permeability of the loop side of Velcro, a sample otherwise difficult to characterize; reasonable values of -56 mV for zeta and 8.7 × 10(-9) m(2) for the permeability were obtained. This approach offers the ability to determine both the zeta potential and the permeability of materials having open structures. Compressing them into a porous plug is unnecessary. As part of the development of the theory, a convenient formula for a flow-weighted volume-averaged space-charge density of the porous medium, -εζ/k, was obtained, where ε is the permittivity, ζ is the zeta potential, and k is the Darcy permeability. The formula is correct when Smoluchowski's equation and Darcy's law are both valid.

  19. Black Hole Dynamic Potentials Koustubh Ajit Kabe

    Indian Academy of Sciences (India)

    Abstract. In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynam- ics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics.

  20. Gravitational Waves from Oscillons with Cuspy Potentials.

    Science.gov (United States)

    Liu, Jing; Guo, Zong-Kuan; Cai, Rong-Gen; Shiu, Gary

    2018-01-19

    We study the production of gravitational waves during oscillations of the inflaton around the minimum of a cuspy potential after inflation. We find that a cusp in the potential can trigger copious oscillon formation, which sources a characteristic energy spectrum of gravitational waves with double peaks. The discovery of such a double-peak spectrum could test the underlying inflationary physics.

  1. The erosive potential of candy sprays

    NARCIS (Netherlands)

    Gambon, D.L.; Brand, H.S.; Nieuw Amerongen, A.V.

    2009-01-01

    Objective To determine the erosive potential of seven different commercially available candy sprays in vitro and in vivo. Material and methods The erosive potential was determined in vitro by measuring the pH and neutralisable acidity. The salivary pH and flow rate were measured in healthy

  2. Dysfunctional methods and the effective potential

    International Nuclear Information System (INIS)

    Dannenberg, A.; California Univ., Berkeley

    1988-01-01

    The effective potential is a useful and much-studied object. It is known to be both real and convex, but a perturbative calculation often gives a complex and nonconvex result. In this letter we address the apparent conflict between perturbation theory and the convexity of the effective potential. (orig.)

  3. Comparative study of quantum anharmonic potentials

    International Nuclear Information System (INIS)

    Amore, Paolo; Aranda, Alfredo; De Pace, Arturo; Lopez, Jorge A.

    2004-01-01

    We perform a study of various anharmonic potentials using a recently developed method. We calculate both the wave functions and the energy eigenvalues for the ground and first excited states of the quartic, sextic and octic potentials with high precision, comparing the results with other techniques available in the literature

  4. Nonresonant approximations to the optical potential

    International Nuclear Information System (INIS)

    Kowalski, K.L.

    1982-01-01

    A new class of approximations to the optical potential, which includes those of the multiple-scattering variety, is investigated. These approximations are constructed so that the optical potential maintains the correct unitarity properties along with a proper treatment of nucleon identity. The special case of nucleon-nucleus scattering with complete inclusion of Pauli effects is studied in detail. The treatment is such that the optical potential receives contributions only from subsystems embedded in their own physically correct antisymmetrized subspaces. It is found that a systematic development of even the lowest-order approximations requires the use of the off-shell extension due to Alt, Grassberger, and Sandhas along with a consistent set of dynamical equations for the optical potential. In nucleon-nucleus scattering a lowest-order optical potential is obtained as part of a systematic, exact, inclusive connectivity expansion which is expected to be useful at moderately high energies. This lowest-order potential consists of an energy-shifted (trho)-type term with three-body kinematics plus a heavy-particle exchange or pickup term. The natural appearance of the exchange term additivity in the optical potential clarifies the role of the elastic distortion in connection with the treatment of these processes. The relationship of the relevant aspects of the present analysis of the optical potential to conventional multiple scattering methods is discussed

  5. Optimized non relativistic potential for quarkonium

    International Nuclear Information System (INIS)

    Rekab, S.; Zenine, N.

    2006-01-01

    For non relativistic quarkonia description, we consider a wide class of quark antiquark potentials in the form of power law. A systematic study is made by optimizing the potential parameters with a fit on quarkonia vector mesons that lie below the threshold for strong decays. Implications of the obtained results are discussed

  6. Transient receptor potential channels in essential hypertension

    DEFF Research Database (Denmark)

    Liu, Daoyan; Scholze, Alexandra; Zhu, Zhiming

    2006-01-01

    The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated.......The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated....

  7. Simulation of action potential propagation in plants.

    Science.gov (United States)

    Sukhov, Vladimir; Nerush, Vladimir; Orlova, Lyubov; Vodeneev, Vladimir

    2011-12-21

    Action potential is considered to be one of the primary responses of a plant to action of various environmental factors. Understanding plant action potential propagation mechanisms requires experimental investigation and simulation; however, a detailed mathematical model of plant electrical signal transmission is absent. Here, the mathematical model of action potential propagation in plants has been worked out. The model is a two-dimensional system of excitable cells; each of them is electrically coupled with four neighboring ones. Ion diffusion between excitable cell apoplast areas is also taken into account. The action potential generation in a single cell has been described on the basis of our previous model. The model simulates active and passive signal transmission well enough. It has been used to analyze theoretically the influence of cell to cell electrical conductivity and H(+)-ATPase activity on the signal transmission in plants. An increase in cell to cell electrical conductivity has been shown to stimulate an increase in the length constant, the action potential propagation velocity and the temperature threshold, while the membrane potential threshold being weakly changed. The growth of H(+)-ATPase activity has been found to induce the increase of temperature and membrane potential thresholds and the reduction of the length constant and the action potential propagation velocity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Superfield tadpole method for SUSY effective potential

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1983-01-01

    Superfield formulation of Weinberg's tadpole method to compute the effective potential in supersymmetric theories is illustrated by considering the general renormalizable action involving only chiral scalar superfields. Unconstrained superfield potentials are introduced to simplify the ''effective'' superfield propagator which is derived in a compact form. (orig.)

  9. Band gaps for the relativistic Mathieu potential

    International Nuclear Information System (INIS)

    Clerk, G.J.; McKellar, B.H.J.

    1992-01-01

    A study of the band structure of a massless particle in a cosine potential is made via the Dirac equation. It is shown that every alternate band gap disappears as a consequence of a periodicity of the potential combined with a peculiar symmetry of the Dirac equation. This basic potential is then used to study a simple one-dimensional model of the nucleus from which it is ascertained that modelling the mean field of the quarks in the nucleus via a pure scalar potential is unsatisfactory. A simple extension involving a combined scalar and vector potential is then proposed as a possible solution to this problem. The effect of the addition of this vector component to the band structure is also investigated. 32 refs

  10. Atom-surface potentials and atom interferometry

    International Nuclear Information System (INIS)

    Babb, J.F.

    1998-01-01

    Long-range atom-surface potentials characterize the physics of many actual systems and are now measurable spectroscopically in deflection of atomic beams in cavities or in reflection of atoms in atomic fountains. For a ground state, spherically symmetric atom the potential varies as -1/R 3 near the wall, where R is the atom-surface distance. For asymptotically large distances the potential is weaker and goes as -1/R 4 due to retardation arising from the finite speed of light. This diminished interaction can also be interpreted as a Casimir effect. The possibility of measuring atom-surface potentials using atomic interferometry is explored. The particular cases studied are the interactions of a ground-state alkali-metal atom and a dielectric or a conducting wall. Accurate descriptions of atom-surface potentials in theories of evanescent-wave atomic mirrors and evanescent wave-guided atoms are also discussed. (author)

  11. Constant potential high-voltage generator

    International Nuclear Information System (INIS)

    Resnick, T.A.; Dupuis, W.A.; Palermo, T.

    1980-01-01

    An X-ray tube voltage generator with automatic stabilization circuitry is disclosed. The generator includes a source of pulsating direct current voltage such as from a rectified 3 phase transformer. This pulsating voltage is supplied to the cathode and anode of an X-ray tube and forms an accelerating potential for electrons within that tube. The accelerating potential is stabilized with a feedback signal which is provided by a feedback network. The network includes an error signal generator which compares an instantaneous accelerating potential with a preferred reference accelerating potential and generates an error function. This error function is transmitted to a control tube grid which in turn causes the voltage difference between X-ray tube cathode and anode to stabilize and thereby reduce the error function. In this way stabilized accelerating potentials are realized and uniform X-ray energy distributions produced. (Auth.)

  12. Effective exchange potentials for electronically inelastic scattering

    International Nuclear Information System (INIS)

    Schwenke, D.W.; Staszewska, G.; Truhlar, D.G.

    1983-01-01

    We propose new methods for solving the electron scattering close coupling equations employing equivalent local exchange potentials in place of the continuum-multiconfiguration-Hartree--Fock-type exchange kernels. The local exchange potentials are Hermitian. They have the correct symmetry for any symmetries of excited electronic states included in the close coupling expansion, and they have the same limit at very high energy as previously employed exchange potentials. Comparison of numerical calculations employing the new exchange potentials with the results obtained with the standard nonlocal exchange kernels shows that the new exchange potentials are more accurate than the local exchange approximations previously available for electronically inelastic scattering. We anticipate that the new approximations will be most useful for intermediate-energy electronically inelastic electron--molecule scattering

  13. The Maritime Potential of ASEAN Economies

    Directory of Open Access Journals (Sweden)

    Hans-Dieter Evers

    2011-01-01

    Full Text Available Countries may utilize a long coastline in relation to their landmass as a resource to develop their maritime economy. This paper argues that ASEAN countries differ in utilizing their maritime potential. As a basis for further comparative studies the Center for Policy Research and International Studies (CenPRIS in Penang developed a set of indicators to measure the maritime potential of nations, the state of their maritime industries, and the degree to which the maritime potential has actually been utilized. Using the CenPRIS Ocean Index (COI shows that Brunei and the Philippines have underutilized their maritime potentials, whereas Singapore and Thailand have made full use of it. Malaysia still has the potential to further develop its maritime economy.

  14. Simple exercises to flatten your potential

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xi; Horn, Bart; Silverstein, Eva [Stanford Univ., Stanford, CA (United States). SLAC and Dept. of Physics; California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stanford Univ., Stanford, CA (United States). SLAC and Dept. of Physics

    2010-11-15

    We show how backreaction of the inflation potential energy on heavy scalar fields can flatten the inflationary potential, as the heavy fields adjust to their most energetically favorable configuration. This mechanism operates in previous UV-complete examples of axion monodromy inflation - flattening a would-be quadratic potential to one linear in the inflaton field - but occurs more generally, and we illustrate the effect with several examples. Special choices of compactification minimizing backreaction may realize chaotic inflation with a quadratic potential, but we argue that a flatter potential such as power-law inflation V({phi}){proportional_to} {phi}{sup p} with p<2 is a more generic option at sufficiently large values of {phi}. (orig.)

  15. Simple exercises to flatten your potential

    International Nuclear Information System (INIS)

    Dong, Xi; Horn, Bart; Silverstein, Eva; California Univ., Santa Barbara, CA; Westphal, Alexander; Stanford Univ., Stanford, CA

    2010-11-01

    We show how backreaction of the inflation potential energy on heavy scalar fields can flatten the inflationary potential, as the heavy fields adjust to their most energetically favorable configuration. This mechanism operates in previous UV-complete examples of axion monodromy inflation - flattening a would-be quadratic potential to one linear in the inflaton field - but occurs more generally, and we illustrate the effect with several examples. Special choices of compactification minimizing backreaction may realize chaotic inflation with a quadratic potential, but we argue that a flatter potential such as power-law inflation V(φ)∝ φ p with p<2 is a more generic option at sufficiently large values of φ. (orig.)

  16. Potential controlled flotation of Sarcheshmeh Molybdenite

    International Nuclear Information System (INIS)

    Kolahdoozan, M.; Noori, H.

    2007-01-01

    Molybdenite flotation in the Sarcheshmeh Copper Complex was studied as a function of pulp potential, controlled using two types of sodium sulfide, a mineral origin and a chemical nature. Air and either plant or laboratory nitrogen were used as flotation careers. Potential readings took place in rougher cells, as it was proved to be vital in the molybdenite circuit. Results showed that, at reducing potentials between -525 and -575 mv, the highest molybdenum recovery of 93% and the lowest copper recovery of 4-15% can be achieved. These potentials did not change considerably by adding extra amounts of sodium sulfide. At more oxidizing potentials, i.e. more than -450 mv, copper recovery increases while the recovery of Molybdenite drops

  17. Canadian wind energy technical and market potential

    International Nuclear Information System (INIS)

    Templin, R.J.; Rangli, R.S.

    1992-01-01

    The current status of wind energy technology in Canada is reviewed, the technical potential of wind energy in Canada is estimated, and the economic market potential is assessed under several scenarios over about the next 25 years. The technical potential is seen to be large, with applications to water pumping on farms, the coupling of wind turbines to diesel-electric systems in remote communities where fuel costs are high, and the supply of electricity to main power grids. The main-grid application has greatest technical potential, but it cannot be economically exploited under the present utility buyback rate structure for intermittent power sources. A change in government policy toward market development of renewable energy sources, such as is already taking place in several European countries, would greatly increase market potential, decrease emissions of CO 2 and SO 2 , and benefit the Canadian wind energy industry. 2 figs., 1 tab

  18. Critical potentials, leptons, and weak currents

    International Nuclear Information System (INIS)

    Smith, P.F.; Lewin, J.D.

    1977-12-01

    A theoretical study is made of the interaction of very strong localised electromagnetic potentials with charged leptons, and with the vacuum state. The principal objective is to investigate the phenomena which occur when the potential reaches or exceeds the critical value at which bound levels are drawn into the lower continuum. The behaviour of bound and continuum solutions of the Dirac equation for the specific model of a short range potential well in an arbitrarily large bounded volume is examined in detail. Vacuum polarisation effects are computed by summation over the infinite set of single particle levels, and special attention is given to the behaviour of the overall charge distribution as the potential strength increases through the critical value. The most significant features of the results are (a) the formation of highly localised electron or muon bound states, (b) similar critical potential strengths for electrons and muons, and (c) redefinition of the vacuum by one charge unit at the critical potential. These features are analogous to some properties of leptonic and hadronic weak currents, and the hypothesis is proposed that strong short range potentials may provide a possible mediating mechanism for the weak interaction and also a lepton confinement mechanism within the structure of hadrons. (author)

  19. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  20. Marketing potential of industrial companies of Ukraine

    Directory of Open Access Journals (Sweden)

    O.V. Oliynyk

    2016-03-01

    Full Text Available The article determines the essence of the marketing potential of the company as a part of improving the efficiency of the company’s activity forming a united mechanism along with industrial and financial subsystems. The components of the total potential of the company, the factors forming structure of the marketing potential of the company and the approaches to the evaluation of such a potential of the company are considered. It is determined that the marketing potential of the company integrates all the marketing resources, reserves and the possibility of their use, and the functioning as well as development of the system are subjected to the achievement of the main company’s goals. The differences in the interpretation of economic, market and marketing potential of the company are identified, although they are related to the subject of entrepreneurship, but they differ in their essence. The substantiation of the essence of marketing potential of the company, the development of an effective mechanism of its management with the possibility of evaluation will contribute to the maximum satisfaction of interests of information consumers’ groups, the formation of strategic directions of the activity, making management decisions at the micro level, the effective functioning in the internal and external markets.

  1. Quaternionic potentials and CP-violation

    International Nuclear Information System (INIS)

    Nishi, Celso Chikahiro

    2000-01-01

    Full text follows: In the formulation of Quantum Mechanics by using a non-commutative ring of quaternions, we attempt to solve the Schroedinger equation with quaternionic potentials. Decay processes can easily be modeled by including complex imaginary potentials. Although, it could be explained as a transition between states under action of a perturbation. Purely imaginary quaternionic potentials can be used to describe CP-violation effects. The neutral kaon system, K 0 - K-bar 0 or K L - K S , represents an example of CP-violation phenomenon. The inclusion of quaternionic potentials imply a reformulation of the whole quantum theory. The use of a quaternionic algebra in discussing the Schroedinger equation leads to the lost of time reversal invariance (T), closely connected to CP violation by the well-known CPT theorem. In particular, we study the Schroedinger equation in presence of a quaternionic potential barrier given in terms of V, real potential acting in the region of width a, and jW, purely quaternionic potential acting in the region of width b. Different cases, |W|/V and b/a, are discussed in view of possible deviations of standard Quantum Mechanics. The complex linear Schroedinger equation is solved for stationary states. The explicit solution contains complex and quaternionic transmission/reflection coefficients. A wave packet treatment needs to make a more realistic and physical description. We briefly discuss possible interpretations and remaining questions. (author)

  2. Potential of renewable and alternative energy sources

    Science.gov (United States)

    Konovalov, V.; Pogharnitskaya, O.; Rostovshchikova, A.; Matveenko, I.

    2015-11-01

    The article deals with application potential of clean alternative renewable energy sources. By means of system analysis the forecast for consumption of electrical energy in Tomsk Oblast as well as main energy sources of existing energy system have been studied up to 2018. Engineering potential of renewable and alternative energy sources is evaluated. Besides, ranking in the order of their efficiency descending is performed. It is concluded that Tomsk Oblast has high potential of alternative and renewable energy sources, among which the most promising development perspective is implementation of gasification stations to save fuel consumed by diesel power stations as well as building wind-power plants.

  3. Jacobi algebra and potentials generated by it

    International Nuclear Information System (INIS)

    Lutsenko, I.M.

    1993-01-01

    It is shown that the Jacobi algebra QJ(3) generates potentials that admit exact solution in relativistic and nonrelativistic quantum mechanics. Being a spectrum-generating dynamic symmetry algebra and possessing the ladder property, QJ(3) makes it possible to find the wave functions in the coordinate representation. The exactly solvable potentials specified in explicit form are regarded as a special case of a larger class of exactly solvable potentials specified implicitly. The connection between classical and quantum problems possessing exact solutions is obtained by means of QJ(3). 13 refs

  4. Wave Energy Potential in the Latvian EEZ

    Science.gov (United States)

    Beriņš, J.; Beriņš, J.; Kalnačs, J.; Kalnačs, A.

    2016-06-01

    The present article deals with one of the alternative forms of energy - sea wave energy potential in the Latvian Exclusice Economic Zone (EEZ). Results have been achieved using a new method - VEVPP. Calculations have been performed using the data on wave parameters over the past five years (2010-2014). We have also considered wave energy potential in the Gulf of Riga. The conclusions have been drawn on the recommended methodology for the sea wave potential and power calculations for wave-power plant pre-design stage.

  5. Model potential for electron scattering from rubidium

    Energy Technology Data Exchange (ETDEWEB)

    Gien, T.E. (Memorial Univ. of Newfoundland, St. John' s, NF (Canada). Dept. of Physics)

    1992-11-28

    An analytic model potential for the e[sup -]-Rb[sup +] system is generated from experimental data, using an iteration method. The potential obtained can reproduce rather accurately the energy levels of rubidium. We employed it in the calculation of elastic differential cross sections for electron (and positron) scatterings from rubidium in the conventional Glauber approximation. The differential cross sections calculated in the model potential approach are compared to those in the frozen-core approach, employing either the Clementi-Roetti or the Szasz-McGinn wavefunctions. The core correlation and polarization effects are found to significantly affect the cross section results. (author).

  6. Model potential for electron scattering from rubidium

    International Nuclear Information System (INIS)

    Gien, T.E.

    1992-01-01

    An analytic model potential for the e - -Rb + system is generated from experimental data, using an iteration method. The potential obtained can reproduce rather accurately the energy levels of rubidium. We employed it in the calculation of elastic differential cross sections for electron (and positron) scatterings from rubidium in the conventional Glauber approximation. The differential cross sections calculated in the model potential approach are compared to those in the frozen-core approach, employing either the Clementi-Roetti or the Szasz-McGinn wavefunctions. The core correlation and polarization effects are found to significantly affect the cross section results. (author)

  7. Interaction potential for two different atoms

    International Nuclear Information System (INIS)

    Kuzmichev, V.E.; Peresypkin, V.V.

    1991-01-01

    Using the rigorous approach to the nonrelativistic four Coulomb particle problem the interaction potentials between an ordinary hydrogen and muonic-hydrogen atoms at large: R>a e +a μ (1), and intermediate: a e >R>>a μ (2) distances, where a e and a μ are the Bohr radii, are calculated in the adiabatic approximation. The van der Waals potential constants in the region (1) and an explicit potential form in the region (2) taking into account both the polarization effects and the electron screening corrections are determined. 10 refs

  8. The tachyon potential in string theory

    International Nuclear Information System (INIS)

    Banks, T.

    1991-01-01

    We argue that the tachyon potential in string theory is exactly given by the unstable quadratic mass term calculated perturbatively around the critical string. The argument is given in terms of the sigma model formulation. The same result follows from the exact Wilson renormalization group equations. The discrepancy with previous calculations of the tachyon potential is explained by the fact that other authors worked near the tachyon mass shell where it is impossible to distinguish a potential from derivative terms in the effective action. (orig.)

  9. Effective Kratzer and Coulomb potentials as limit cases of a multiparameter exponential-type potential

    Energy Technology Data Exchange (ETDEWEB)

    García-Ravelo, J., E-mail: g.ravelo@hotmail.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Menéndez, A.; García-Martínez, J. [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, México D.F., 07738 (Mexico); Schulze-Halberg, A. [Department of Mathematics and Actuarial Science and Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, IN 46408 (United States)

    2014-06-13

    We show that the effective Kratzer and Coulomb potentials can be obtained by taking particular limits of a multiparameter exponential potential that was studied recently. Moreover, we demonstrate that the bound state solutions of the exponential potential reduce correctly to their well-known counterparts associated with the Kratzer and Coulomb potentials. As a byproduct, we obtain a new limit relation for the hypergeometric function. - Highlights: • Kratzer and Coulomb potentials are limit cases of an exponential-type potential. • From exact s-waves, approximate solutions for l-waves are obtained. • l-waves of the potential tend to the solutions of the Kratzer and Coulomb potentials. • A non-evident identity between hypergeometric functions is demonstrated.

  10. Effective Kratzer and Coulomb potentials as limit cases of a multiparameter exponential-type potential

    International Nuclear Information System (INIS)

    García-Ravelo, J.; Menéndez, A.; García-Martínez, J.; Schulze-Halberg, A.

    2014-01-01

    We show that the effective Kratzer and Coulomb potentials can be obtained by taking particular limits of a multiparameter exponential potential that was studied recently. Moreover, we demonstrate that the bound state solutions of the exponential potential reduce correctly to their well-known counterparts associated with the Kratzer and Coulomb potentials. As a byproduct, we obtain a new limit relation for the hypergeometric function. - Highlights: • Kratzer and Coulomb potentials are limit cases of an exponential-type potential. • From exact s-waves, approximate solutions for l-waves are obtained. • l-waves of the potential tend to the solutions of the Kratzer and Coulomb potentials. • A non-evident identity between hypergeometric functions is demonstrated

  11. Unintended Positional Drift and Its Potential Solutions

    DEFF Research Database (Denmark)

    Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

    2013-01-01

    many users unintentionally move forward while walking in place. We refer to this phenomenon accidental movement as Unintended Positional Drift. The poster presents evidence of the phenomenon's existence and subsequently discusses different design solutions which potentially could circumvent the problem....

  12. Ozone-forming potential of reformulated gasoline

    National Research Council Canada - National Science Library

    Committee on Ozone-Forming Potential of Reformulated Gasoline, National Research Council

    ... and comparison of the emissions from motor vehicles using different reformulated gasolines based on their ozone-forming potentials and to assess the concomitant impact of that approach on air-quality benefits...

  13. Potential organ donor audit in Ireland.

    LENUS (Irish Health Repository)

    Hegarty, M

    2010-11-01

    As increasing demand for organs is a challenge for transplant services worldwide it is essential to audit the process of organ donation. To address this, a national audit of potential organ donors was undertaken across hospitals with Intensive Care Units (N = 36). Questionnaires were returned on all patients (n = 2073) who died in these units from 1\\/9\\/07-31\\/8\\/08; 200 (10%) of these patients were considered for Brain Stem Testing (BST), 158 patients (79%) were diagnosed Brain Stem Dead (BSD) and 138 patients (87%) became potential donors. Consent for donation was given by 92 (69%) next of kin and 90 potential donors (65%) became organ donors. There was no evidence of a large number of potential organ donors being missed. Recommendations included completion of BSTs on all appropriate patients, development of support on BST, referral of all BSD patients to the Organ Procurement Service; enhanced co-ordination within hospitals and sustained information\\/education campaigns.

  14. Effective potentials in gauge field theories

    International Nuclear Information System (INIS)

    Caldas, P.S.S.; Fleming, H.; Garcia, R.L.

    An elementary and very efficient method for computing the effective potential of any theory containing scalar bosons is described. Examples include massless scalar electrodynamics and Yang-Mills theories [pt

  15. Potential targets for lung squamous cell carcinoma

    Science.gov (United States)

    Researchers have identified potential therapeutic targets in lung squamous cell carcinoma, the second most common form of lung cancer. The Cancer Genome Atlas (TCGA) Research Network study comprehensively characterized the lung squamous cell carcinoma gen

  16. Potential in stochastic differential equations: novel construction

    International Nuclear Information System (INIS)

    Ao, P

    2004-01-01

    There is a whole range of emergent phenomena in a complex network such as robustness, adaptiveness, multiple-equilibrium, hysteresis, oscillation and feedback. Those non-equilibrium behaviours can often be described by a set of stochastic differential equations. One persistent important question is the existence of a potential function. Here we demonstrate that a dynamical structure built into stochastic differential equation allows us to construct such a global optimization potential function. We present an explicit construction procedure to obtain the potential and relevant quantities. In the procedure no reference to the Fokker-Planck equation is needed. The availability of the potential suggests that powerful statistical mechanics tools can be used in nonequilibrium situations. (letter to the editor)

  17. Ozone-forming potential of reformulated gasoline

    National Research Council Canada - National Science Library

    Committee on Ozone-Forming Potential of Reformulated Gasoline, National Research Council

    ...) technical aspects of various air-quality issues related to RFG assessment, and (3) the sensitivity of evaluations of the relative ozone-forming potentials to factors related to fuel properties and the variability of vehicle technologies and driving patterns.

  18. ECONOMIC POTENTIALS OF FISH MARKETING AND WOMEN ...

    African Journals Online (AJOL)

    AKINYEMISI

    efficiency greater than one which indicated profitability of the enterprise and further showed the potential of fish marketing contribution to women's economic empowerment. The regression results showed that the variables which positively and.

  19. Potential Logistics Cost Savings from Engine Commonality

    National Research Council Canada - National Science Library

    Henderson, Robert L; Higer, Matthew W

    2007-01-01

    The purpose of this MBA Project is to determine potential logistics cost savings the USAF and DoD could have realized through the life of the F-16 fighter aircraft had they required engine commonality...

  20. Meson-exchange N-N potential

    International Nuclear Information System (INIS)

    Nutt, W.T.

    1976-01-01

    A meson-theoretic model of the intermediate range nucleon-nucleon potential is presented with emphasis placed on the two-pion exchange contribution. The Bethe-Salpeter equation is reduced, by the Blankenbecler-Sugar technique, to a Lippmann-Schwinger equation, from which an approximate nonlocal, energy-dependent potential is obtained. The nucleon-antinucleon pair contribution, which plagues meson-theoretical two-pion calculations, is suppressed by the complex poles of the one-nucleon Green's function. The importance of the retention of the explicit energy dependence of the potential is demonstrated by calculating the off-shell scattering matrices. The potential is presented in a linearized (in energy) form with the core region adjusted to produce a fit to low energy data