WorldWideScience

Sample records for active conductance states

  1. Reversible control of kinesin activity and microtubule gliding speeds by switching the doping states of a conducting polymer support

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Brett D [US Naval Research Laboratory, Code 6930, Washington, DC 20375 (United States); Velea, Luminita M [US Naval Research Laboratory, Code 6930, Washington, DC 20375 (United States); Soto, Carissa M [US Naval Research Laboratory, Code 6930, Washington, DC 20375 (United States); Whitaker, Craig M [US Naval Academy, Department of Chemistry, Annapolis, MD 21402 (United States); Gaber, Bruce P [US Naval Research Laboratory, Code 6930, Washington, DC 20375 (United States); Ratna, Banahalli [US Naval Research Laboratory, Code 6930, Washington, DC 20375 (United States)

    2007-02-07

    We describe a method for reversibly controlling the ATPase activity of streptavidin-linked kinesin by changing the doping states of a conducting polymer support. When the polymer (poly(CH{sub 2}OH-EDOT)) was electrochemically switched from its dedoped (semiconducting) state to its doped (conducting) state, the ATPase activity of the adsorbed kinesin complex decreased by 35% with a concomitant decrease in the gliding speeds of kinesin-driven microtubules. When the polymer was switched back to its original dedoped state, nearly identical increases were observed in the kinesin ATPase activity and microtubule speeds. Use of a fluorescent ATP substrate analogue showed that the total amount of kinesin adsorbed on the poly(CH{sub 2}OH-EDOT) surface remained constant as the doping state of the polymer was switched. The microtubules exhibited nearly identical speed differences on the doped and dedoped surfaces for both chemical and electrochemical doping methods. Michaelis-Menten modelling suggests that the doped surface acts as an 'uncompetitive inhibitor' of kinesin. This work represents an investigation into the phenomenon of an electrically switchable surface exerting a moderating effect on the activity of an adsorbed protein that does not contain a bound, electroactive metal ion.

  2. 78 FR 78788 - Nondiscrimination in Programs or Activities Conducted by the United States Department of Agriculture

    Science.gov (United States)

    2013-12-27

    ... compliance and complaint processing activities to better protect the rights of USDA customers. OASCR's.... This amendment is intended to encourage the early resolution of customer complaints. Finally, USDA... rights compliance and complaint processing activities to better protect the rights of USDA's...

  3. Faradic redox active material of Cu7S4 nanowires with a high conductance for flexible solid state supercapacitors

    Science.gov (United States)

    Javed, Muhammad Sufyan; Dai, Shuge; Wang, Mingjun; Xi, Yi; Lang, Qiang; Guo, Donglin; Hu, Chenguo

    2015-08-01

    The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in a high pseudocapacitive performance with a relatively high specific energy and specific power. Such a new type of pseudocapacitive material of Cu7S4-NWs with its low cost is very promising for actual application in supercapacitors.The exploration of high Faradic redox active materials with the advantages of low cost and low toxicity has been attracting great attention for producing high energy storage supercapacitors. Here, the high Faradic redox active material of Cu7S4-NWs coated on a carbon fiber fabric (CFF) is directly used as a binder-free electrode for a high performance flexible solid state supercapacitor. The Cu7S4-NW-CFF supercapacitor exhibits excellent electrochemical performance such as a high specific capacitance of 400 F g-1 at the scan rate of 10 mV s-1 and a high energy density of 35 Wh kg-1 at a power density of 200 W kg-1, with the advantages of a light weight, high flexibility and long term cycling stability by retaining 95% after 5000 charge-discharge cycles at a constant current of 10 mA. The high Faradic redox activity and high conductance behavior of the Cu7S4-NWs result in

  4. Ionic conduction in the solid state

    Indian Academy of Sciences (India)

    P Padma Kumar; S Yashonath

    2006-01-01

    Solid state ionic conductors are important from an industrial viewpoint. A variety of such conductors have been found. In order to understand the reasons for high ionic conductivity in these solids, there have been a number of experimental, theoretical and computational studies in the literature. We provide here a survey of these investigations with focus on what is known and elaborate on issues that still remain unresolved. Conductivity depends on a number of factors such as presence of interstitial sites, ion size, temperature, crystal structure etc. We discuss the recent results from atomistic computer simulations on the dependence of conductivity in NASICONs as a function of composition, temperature, phase change and cation among others. A new potential for modelling of NASICON structure that has been proposed is also discussed.

  5. Fabrication and characterization of solid state conducting polymer actuators

    Science.gov (United States)

    Xie, Jian; Sansinena, Jose-Maria; Gao, Junbo; Wang, Hsing-Lin

    2004-07-01

    We report here the fabrication and characterization of solid-state conducting polymer actuators. The electrochemical activity of polyaniline (PANI) thin film coated with solid-state polyelectrolyte is very similar to the polyaniline thin film in an aqueous solution. The solid-state actuator is adhered to a lever arm of a force transducer and the force generation is measured in real time. The force generated by the actuator is found to be length dependent. However, the overall torque generated by the actuators with different lengths remains essentially the same. The effect of stimulation signals such as voltage, and current, on the bending angle and displacement is also studied using square wave potential.

  6. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-01-01

    In this study, we report the fabrication of solid-state asymmetric supercapacitors (ASCs) based on conducting polymer electrodes on a plastic substrate. Nanostructured conducting polymers of poly(3,4-ethylenedioxythiophene), PEDOT, and polyaniline (PANI) are deposited electrochemically over Au-coated polyethylene naphthalate (PEN) plastic substrates. Due to the electron donating nature of the oxygen groups in the PEDOT, reduction potentials are higher, allowing it to be used as a negative electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid state supercapacitors with PANI as a positive electrode while employing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte. The ASCs exhibit a maximum power density of 2.8 W cm-3 at an energy density of 9 mW h cm-3, which is superior to the carbonaceous and metal oxide based ASC solid state devices. Furthermore, the tandem configuration of asymmetric supercapacitors is shown to be capable of powering a red light emitting diode for about 1 minute after charging for 10 seconds. © The Royal Society of Chemistry 2015.

  7. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-02-16

    In this study, we report the fabrication of solid-state asymmetric supercapacitors (ASCs) based on conducting polymer electrodes on a plastic substrate. Nanostructured conducting polymers of poly(3,4-ethylenedioxythiophene), PEDOT, and polyaniline (PANI) are deposited electrochemically over Au-coated polyethylene naphthalate (PEN) plastic substrates. Due to the electron donating nature of the oxygen groups in the PEDOT, reduction potentials are higher, allowing it to be used as a negative electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid state supercapacitors with PANI as a positive electrode while employing polyvinyl alcohol (PVA)/H2SO4 gel electrolyte. The ASCs exhibit a maximum power density of 2.8 W cm−3 at an energy density of 9 mW h cm−3, which is superior to the carbonaceous and metal oxide based ASC solid state devices. Furthermore, the tandem configuration of asymmetric supercapacitors is shown to be capable of powering a red light emitting diode for about 1 minute after charging for 10 seconds.

  8. [Bone Conduction and Active Middle Ear Implants].

    Science.gov (United States)

    Volkenstein, S; Thomas, J P; Dazert, S

    2016-05-01

    The majority of patients with moderate to severe hearing loss can be supplied with conventional hearing aids depending on severity and cause for hearing loss in a satisfying way. However, some patients either do not benefit enough from conventional hearing aids or cannot wear them due to inflammatory reactions and chronic infections of the external auditory canal or due to anatomical reasons. For these patients there are fully- and semi-implantable middle ear and bone conduction implants available. These devices either directly stimulate the skull (bone conduction devices), middle ear structures (active middle ear implants) or the cochlea itself (direct acoustic stimulation). Patients who failed surgical hearing rehabilitation or do not benefit from conventional hearing aids may achieve a significant better speech understanding and tremendous improvement in quality of life by implantable hearing devices with careful attention to the audiological and anatomical indication criteria.

  9. Guidance manual for conducting technology demonstration activities

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-01

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

  10. State of hydration and electrical conductance of ichthyotic skin

    Directory of Open Access Journals (Sweden)

    Gupta A

    1990-01-01

    Full Text Available Dry skin of twelve subjects suffering from ichthyosis vulgaris and the efficacy of a moisturiser-Cotaryl were quantitatively assessed by measuring the skin surface hydration and high frequency (3.5 MHz electrical conductance of skin. The state of hydration and conductance of ichthyotic skin were 86.9 + 24.6 and 11.0 + 5.7 micro-mho respectively, being much less-compared to 132. 0 + 5.3 and 72.5 + 54.0 micro-mho ofnormal subjects. The moisturiser increased the state of hydration and also the electrical conductance of the stratum corneuni to near-normal values and maintained them as long as the application continued. However, both the hydration and the conductance fell sharply within a week of withrawal of the moisturiser. A moisturiser was thus undoubtedly efficacious in ichthyotic skin, but the effect was only temporary. The state of hydration was found, at all stages, to bear a strong positive correlation (r = 0.69 to 0.80 with the skin conductance.

  11. The State of Water in Proton Conducting Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Allcock, Harry R.; Benesi, Alan; Macdonald, Digby D.

    2010-08-27

    The research carried out under grant No. DE-FG02-07ER46371, "The State of Water in Proton Conducting Membranes", during the period June 1, 2008 - May 31, 2010 was comprised of three related parts. These are: 1. An examination of the state of water in classical proton conduction membranes with the use of deuterium T1 NMR spectroscopy (Allcock and Benesi groups). 2. A dielectric relaxation examination of the behavior of water in classical ionomer membranes (Macdonald program). 3. Attempts to synthesize new proton-conduction polymers and membranes derived from the polyphosphazene system. (Allcock program) All three are closely related, crucial aspects of the design and development of new and improved polymer electrolyte fuel cell membranes on which the future of fuel cell technology for portable applications depends.

  12. Steady States and Universal Conductance in a Quenched Luttinger Model

    Science.gov (United States)

    Langmann, Edwin; Lebowitz, Joel L.; Mastropietro, Vieri; Moosavi, Per

    2017-01-01

    We obtain exact analytical results for the evolution of a 1+1-dimensional Luttinger model prepared in a domain wall initial state, i.e., a state with different densities on its left and right sides. Such an initial state is modeled as the ground state of a translation invariant Luttinger Hamiltonian {H_{λ}} with short range non-local interaction and different chemical potentials to the left and right of the origin. The system evolves for time t > 0 via a Hamiltonian {H_{λ'}} which differs from {H_{λ}} by the strength of the interaction. Asymptotically in time, as {t to ∞}, after taking the thermodynamic limit, the system approaches a translation invariant steady state. This final steady state carries a current I and has an effective chemical potential difference {μ+ - μ-} between right- (+) and left- (-) moving fermions obtained from the two-point correlation function. Both I and {μ+ - μ-} depend on {λ} and {λ'}. Only for the case {λ = λ' = 0} does {μ+ - μ-} equal the difference in the initial left and right chemical potentials. Nevertheless, the Landauer conductance for the final state, {G = I/(μ+ - μ-)}, has a universal value equal to the conductance quantum {e^2/h} for the spinless case.

  13. Steady States and Universal Conductance in a Quenched Luttinger Model

    Science.gov (United States)

    Langmann, Edwin; Lebowitz, Joel L.; Mastropietro, Vieri; Moosavi, Per

    2016-05-01

    We obtain exact analytical results for the evolution of a 1+1-dimensional Luttinger model prepared in a domain wall initial state, i.e., a state with different densities on its left and right sides. Such an initial state is modeled as the ground state of a translation invariant Luttinger Hamiltonian {H_{λ}} with short range non-local interaction and different chemical potentials to the left and right of the origin. The system evolves for time t > 0 via a Hamiltonian {H_{λ'}} which differs from {H_{λ}} by the strength of the interaction. Asymptotically in time, as {t to &infty}; , after taking the thermodynamic limit, the system approaches a translation invariant steady state. This final steady state carries a current I and has an effective chemical potential difference {μ+ - μ-} between right- (+) and left- (-) moving fermions obtained from the two-point correlation function. Both I and {μ+ - μ-} depend on {λ} and {λ'} . Only for the case {λ = λ' = 0} does {μ+ - μ-} equal the difference in the initial left and right chemical potentials. Nevertheless, the Landauer conductance for the final state, {G = I/(μ+ - μ-)} , has a universal value equal to the conductance quantum {e^2/h} for the spinless case.

  14. Optical Conductivity of Topological Surface States with Emergent Supersymmetry

    Science.gov (United States)

    Witczak-Krempa, William; Maciejko, Joseph

    2016-03-01

    Topological states of electrons present new avenues to explore the rich phenomenology of correlated quantum matter. Topological insulators (TIs) in particular offer an experimental setting to study novel quantum critical points (QCPs) of massless Dirac fermions, which exist on the sample's surface. Here, we obtain exact results for the zero- and finite-temperature optical conductivity at the semimetal-superconductor QCP for these topological surface states. This strongly interacting QCP is described by a scale invariant theory with emergent supersymmetry, which is a unique symmetry mixing bosons and fermions. We show that supersymmetry implies exact relations between the optical conductivity and two otherwise unrelated properties: the shear viscosity and the entanglement entropy. We discuss experimental considerations for the observation of these signatures in TIs.

  15. Electronic thermal conductivity in a superconducting vortex state

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, H. [Department of Physics, Okayama University, Tsushima, Okayama 700-8530 (Japan)], E-mail: adachi@itp.phys.ethz.ch; Miranovic, P. [Department of Physics, University of Montenegro, Podgorica 81000 (Montenegro); Ichioka, M.; Machida, K. [Department of Physics, Okayama University, Tsushima, Okayama 700-8530 (Japan)

    2007-10-01

    The longitudinal component of the electronic thermal conductivity {kappa}{sub xx} in a superconducting vortex state is calculated as a function of magnetic field B. Calculations are performed by taking account of the spatial dependence of normal Green's function g, which was neglected in the previous studies using the Brandt-Pesch-Tewordt method. We discuss the possibility of using {kappa}{sub xx}(B) as a probe of the pair potential symmetry.

  16. Electronic thermal conductivity in a superconducting vortex state

    Science.gov (United States)

    Adachi, H.; Miranovic, P.; Ichioka, M.; Machida, K.

    2007-10-01

    The longitudinal component of the electronic thermal conductivity κxx in a superconducting vortex state is calculated as a function of magnetic field B. Calculations are performed by taking account of the spatial dependence of normal Green's function g, which was neglected in the previous studies using the Brandt-Pesch-Tewordt method. We discuss the possibility of using κxx(B) as a probe of the pair potential symmetry.

  17. Irregular Firing and High-Conductance States in Spinal Motoneurons during Scratching and Swimming

    DEFF Research Database (Denmark)

    Guzulaitis, Robertas; Hounsgaard, Jorn; Alaburda, Aidas

    2016-01-01

    in general. Here we compare conductance and firing patterns in spinal motoneurons during network activity for scratching and swimming in an ex vivo carapace-spinal cord preparation from adult turtles (Trachemys scripta elegans). The pattern and relative engagement of motoneurons are distinctly different...... in scratching and swimming. Nevertheless, we found increased synaptic fluctuations in membrane potential, irregular firing, and increased conductance in spinal motoneurons during scratch and swim network activity. Our finding indicates that intense synaptic activation of motoneurons is a general feature...... not only during scratching but also during swimming. Our findings suggest that irregular firing and high-conductance states could be a general feature for motor behaviors....

  18. The dependence of the electronic conductivity of carbon molecular sieve electrodes on their charging states.

    Science.gov (United States)

    Pollak, Elad; Genish, Isaschar; Salitra, Gregory; Soffer, Abraham; Klein, Lior; Aurbach, Doron

    2006-04-13

    The dependence of the electronic conductivity of activated carbon electrodes on their potential in electrolyte solutions was examined. Kapton polymer films underwent carbonization (1000 degrees C), followed by a mild oxidation process (CO(2) at 900 degrees C) for various periods of time, to obtain carbons of different pore structures. A specially designed cell was assembled in order to measure the conductivity of carbon electrodes at different potentials in solutions. When the carbon electrodes possessed molecular sieving properties, a remarkable dependence of their conductivity on their charging state was observed. Aqueous electrolyte solutions containing ions of different sizes were used in order to demonstrate this phenomenon. As the average pore size of the activated carbons was larger, their molecular sieving ability was lower, and the dependence of their conductivity on their charging state regained its classical form. This behavior is discussed herein.

  19. Surface states and conductivity of silicon nano-wires

    Science.gov (United States)

    Kumar Bhaskar, Umesh; Pardoen, Thomas; Passi, Vikram; Raskin, Jean-Pierre

    2013-04-01

    The transport characteristics of low dimensional semiconductors like silicon nano-wires (SiNWs) rarely conform to expectations from geometry and dopant density, exhibiting significant variations as a function of different surface terminations/conditions. The association of these mechanisms with surface states and their exact influence on practical SiNW devices still remains largely unclear. Herein, we report on the influence of surface state charge distributions on SiNW transport characteristics. For this study, p-type SiNW devices with widths of 50, 100, and 2000 nm are fabricated from 25, 50, and 200 nm-thick SOI wafers. A ˜five order difference in effective carrier concentration was observed in the initial SiNWs characteristics, when comparing SiNWs fabricated with and without a thermal oxide. The removal of the surface oxide by a hydrogen fluoride (HF) treatment results in a SiNW conductance drop up to ˜six orders of magnitude. This effect is from a surface depletion of holes in the SiNW induced by positive surface charges deposited as a result of the HF treatment. However, it is observed that this charge density is transient and is dissipated with the re-growth of an oxide layer. In summary, the SiNW conductance is shown to vary by several orders of magnitude, while comparing its characteristics for the three most studied surface conditions: with a native oxide, thermal oxide and HF induced H-terminations. These results emphasize the necessity to interpret the transport characteristics of SiNWs with respect to its surface condition, during future investigations pertaining to the physical properties of SiNWs, like its piezo-resistance. As a sequel, prospects for efficiently sensing an elementary reduction/oxidation chemical process by monitoring the variation of SiNW surface potential, or in practice the SiNW conductance, is demonstrated.

  20. Role of active dendritic conductances in subthreshold input integration

    OpenAIRE

    Rinzel John; Remme Michiel

    2010-01-01

    Dendrites of many types of neurons contain voltage-dependent conductances that are active at subthreshold membrane potentials. To understand the computations neurons perform it is key to understand the role of active dendrites in the subthreshold processing of synaptic inputs. We examine systematically how active dendritic conductances affect the time course of postsynaptic potentials propagating along dendrites, and how they affect the interaction between such signals. Voltage-dependent curr...

  1. Steady-state magnetohydrodynamic flow around an unmagnetized conducting sphere

    Energy Technology Data Exchange (ETDEWEB)

    Romanelli, N.; Gómez, D.; Bertucci, C. [Group of Astrophysical Flows, Instituto de Astronomía y Física del Espacio, Buenos Aires (Argentina); Delva, M., E-mail: nromanelli@iafe.uba.ar, E-mail: Magda.Delva@oeaw.ac.at [Space Research Institute, Graz (Austria)

    2014-07-01

    The noncollisional interaction between conducting obstacles and magnetized plasma winds can be found in different scenarios, from the interaction occurring between regions inside galaxy clusters to the interaction between the solar wind and Mars, Venus, and active comets, or even the interaction between Titan and the Saturnian magnetospheric flow. These objects generate, through several current systems, perturbations in the streaming magnetic field leading to its draping around the obstacle's effective conducting surface. Recent observational results suggest that several properties associated with magnetic field draping, such as the location of the polarity reversal layer of the induced magnetotail, are affected by variations in the conditions of the streaming magnetic field. To improve our understanding of these phenomena, we perform a characterization of several magnetic field draping signatures by analytically solving an ideal problem in which a perfectly conducting magnetized plasma (with frozen-in magnetic field conditions) flows around a spherical body for various orientations of the streaming magnetic field. In particular, we compute the shift of the inverse polarity reversal layer as the orientation of the background magnetic field is changed.

  2. Selective Activation of Cystic Fibrosis Transmembrane Conductance Regulator Cl- and HCO3- Conductances

    Directory of Open Access Journals (Sweden)

    Reddy MM

    2001-07-01

    Full Text Available While cystic fibrosis transmembrane conductance regulator (CFTR is well known to function as a Cl(- channel, some mutations in the channel protein causing cystic fibrosis (CF disrupt another vital physiological function, HCO(3(- transport. Pathological implications of derailed HCO(3(- transport are clearly demonstrated by the pancreatic destruction that accompany certain mutations in CF. Despite the crucial role of HCO(3(- in buffering pH, little is known about the relationship between cause of CF pathology and the molecular defects arising from specific mutations. Using electrophysiological techniques on basolaterally permeabilized preparations of microperfused native sweat ducts, we investigated whether: a CFTR can act as a HCO(3(- conductive channel, b different conditions for stimulating CFTR can alter its selectivity to HCO(3(- and, c pancreatic insufficiency correlate with HCO(3(- conductance in different CFTR mutations. We show that under some conditions stimulating CFTR can conduct HCO(3(-. HCO(3(- conductance in the apical plasma membranes of sweat duct appears to be mediated by CFTR and not by any other Cl(- channel because HCO(3(- conductance is abolished when CFTR is: a deactivated by removing cAMP and ATP, b blocked by 1 mM DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid in the cytoplasmic bath and, c absent in the plasma membranes of DeltaF508 CF ducts. Further, the HCO(3(-/Cl(- selectivity of CFTR appears to be dependent on the conditions of stimulating CFTR. That is, CFTR activated by cAMP + ATP appears to conduct both HCO(3(- and Cl(- (with an estimated selectivity ratio of 0.2 to 0.5. However, we found that in the apparent complete absence of cAMP and ATP, cytoplasmic glutamate activates CFTR Cl(- conductance without any HCO(3(- conductance. Glutamate activated CFTR can be induced to conduct HCO(3(- by the addition of ATP without cAMP. The non-hydrolysable AMP-PNP (5'-adenylyl imidodiphosphate cannot substitute for ATP

  3. Experiment study of forming and activation of conductive film of the surface conduction electron emitter display

    Institute of Scientific and Technical Information of China (English)

    LEI Xin; XU Wei-jun; LIU Chun-liang; LIANG Zhi-hu

    2007-01-01

    The forming and activation of the conductive films are studied experimentally. The power supply,a peak-to-peak 30 V triangle profile voltage,is applied to three kinds of conductive films that contain 0.25%,0.5%,and 1% of palladium respectively. In the experiments we contrasted the values of related parameter in different conditions,observed the lumi nous spots on the anode panel,dealt with and analyzed the related data,and compared the positions and the amount of the luminous spots. We have gotten the conclusion that there is a threshold value Uth. The emission current Ie will increase rapidly when the device voltage Uf is greater than Uth. And the emission current Ie could be controlled by the device voltage Uf.The positions of the luminous spots on the anode panel are related with the device voltage Uf.

  4. Solid-state synthesis of a conducting polythiophene via an unprecedented heterocyclic coupling reaction.

    Science.gov (United States)

    Meng, Hong; Perepichka, Dmitrii F; Bendikov, Michael; Wudl, Fred; Pan, Grant Z; Yu, Wenjiang; Dong, Wenjian; Brown, Stuart

    2003-12-10

    Prolonged storage ( approximately 2 years) or gentle heating (50-80 degrees C) of crystalline 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) affords a highly conducting, bromine-doped poly(3,4-ethylenedioxythiophene) (PEDOT), as confirmed by solid-state NMR, FTIR, CV, and vis-NIR spectroscopies. The novel solid-state polymerization (SSP) does not occur for 2,5-dichloro-3,4-ethylenedioxythiophene (DCEDOT), and requires a much higher temperature (>130 degrees C) for 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT). X-ray structural analysis of the above dihalothiophenes reveals short Hal.Hal distances between adjacent molecules in DBEDOT and DIEDOT, but not in DCEDOT. The polymerization may also occur in the melt but is significantly slower and leads to poorly conductive material. Detailed studies of the reaction were performed using ESR, DSC, microscopy, and gravimetric analyses. SSP starts on crystal defect sites; it is exothermic by 14 kcal/mol and requires activation energy of approximately 26 kcal/mol (for DBEDOT). The temperature dependence of the conductivity of SSP-PEDOT (sigma(rt) = 20-80 S/cm) reveals a slight thermal activation. It can be further increased by a factor of 2 by doping with iodine. Using this approach, thin films of PEDOT with conductivity as high as 20 S/cm were fabricated on insulating flexible plastic surfaces.

  5. Occupational Safety and Health Activities Conducted across Countries in Asia.

    Science.gov (United States)

    Park, Jung-Keun; Khai, Ton T

    2015-06-01

    Three occupational safety and health (OSH) activities, one international and two national workshops, were documented as part of OSH activities conducted under the International Labor Organization/Korea Partnership Program in the year 2011-2012. This study aimed to provide information on what the three OSH activities were implemented and how they contributed to the improvement of OSH in Asian countries. The international workshop was useful for the participants to understand a variety of information on OSH as well as participatory action-oriented training (PAOT) approaches at the regional and global levels. The two national workshops were practical for participants to strengthen their knowledge and skills on the PAOT at the enterprise and national levels. The study shows that the three OSH activities contributed to the understanding of the participants on OSH and PAOT, and that the activities promoted the improvement of OSH across countries in Asia.

  6. Methodological Approaches in Conducting Overviews: Current State in HTA Agencies

    Science.gov (United States)

    Pieper, Dawid; Antoine, Sunya-Lee; Morfeld, Jana-Carina; Mathes, Tim; Eikermann, Michaela

    2014-01-01

    Objectives: Overviews search for reviews rather than for primary studies. They might have the potential to support decision making within a shorter time frame by reducing production time. We aimed to summarize available instructions for authors intending to conduct overviews as well as the currently applied methodology of overviews in…

  7. ATPase activity of the cystic fibrosis transmembrane conductance regulator.

    Science.gov (United States)

    Li, C; Ramjeesingh, M; Wang, W; Garami, E; Hewryk, M; Lee, D; Rommens, J M; Galley, K; Bear, C E

    1996-11-08

    The gene mutated in cystic fibrosis codes for the cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic AMP-activated chloride channel thought to be critical for salt and water transport by epithelial cells. Plausible models exist to describe a role for ATP hydrolysis in CFTR channel activity; however, biochemical evidence that CFTR possesses intrinsic ATPase activity is lacking. In this study, we report the first measurements of the rate of ATP hydrolysis by purified, reconstituted CFTR. The mutation CFTRG551D resides within a motif conserved in many nucleotidases and is known to cause severe human disease. Following reconstitution the mutant protein exhibited both defective ATP hydrolysis and channel gating, providing direct evidence that CFTR utilizes ATP to gate its channel activity.

  8. Steady-State Density Functional Theory for Finite Bias Conductances.

    Science.gov (United States)

    Stefanucci, G; Kurth, S

    2015-12-09

    In the framework of density functional theory, a formalism to describe electronic transport in the steady state is proposed which uses the density on the junction and the steady current as basic variables. We prove that, in a finite window around zero bias, there is a one-to-one map between the basic variables and both local potential on as well as bias across the junction. The resulting Kohn-Sham system features two exchange-correlation (xc) potentials, a local xc potential, and an xc contribution to the bias. For weakly coupled junctions the xc potentials exhibit steps in the density-current plane which are shown to be crucial to describe the Coulomb blockade diamonds. At small currents these steps emerge as the equilibrium xc discontinuity bifurcates. The formalism is applied to a model benzene junction, finding perfect agreement with the orthodox theory of Coulomb blockade.

  9. High-conductance states in a mean-field cortical network model

    DEFF Research Database (Denmark)

    Lerchner, Alexander; Ahmadi, Mandana; Hertz, John

    2004-01-01

    cortical network model with random connectivity and conductance-based synapses. We employ mean-field theory with correctly colored noise to describe temporal correlations in the neuronal activity. Our results illuminate the connection between two independent experimental findings: high-conductance states......Measured responses from visual cortical neurons show that spike times tend to be correlated rather than exactly Poisson distributed. Fano factors vary and are usually greater than 1, indicating a tendency toward spikes being clustered. We show that this behavior emerges naturally in a balanced...... of cortical neurons in their natural environment, and variable non-Poissonian spike statistics with Fano factors greater than 1. (C) 2004 Elsevier B.V. All rights reserved....

  10. Principles and Rules of Conduct in the Internal Audit Activity

    Directory of Open Access Journals (Sweden)

    Mihaela Iuliana Dumitru

    2016-02-01

    Full Text Available The objectives of the paper are to present the basic principles governing the internal audit mission as well as the code of conduct that must be observed in exercising such a mission, because the completion of a professional audit mission implies precisely the compliance with the two category of elements. Consequently, this paper is meant to be added to the practice specific to this field as support in exercising the internal audit according to the market requirements. For this purpose, we analysed the above-mentioned elements, presenting brief examples in support of the importance of the approached topics. Thus, from the practical point of view, we can notice the mechanisms used to apply these principles and how the compliance with the audit specific audit conduct lead to a more efficient activity. For these reasons, we can say that the paper is an element of interest both for the academic field (as a starting point for the support of practical approaches and also for the future researches in order to improve the specific audit activity.

  11. Surface state conductivity in epitaxially grown Bi1-x Sb x (111) films

    Science.gov (United States)

    Koch, Julian; Kröger, Philipp; Pfnür, Herbert; Tegenkamp, Christoph

    2016-09-01

    Topologically non-trivial surface states were reported first on {{Bi}}1-xSb x bulk crystals. In this study we present transport measurements performed on thin {{Bi}}1-xSb x -films (up to 24 nm thickness) grown epitaxially on Si(111) with various Sb-concentrations (up to x = 0.22). The analysis of the temperature dependency allowed us to distinguish between different transport channels originating from surface and bulk bands as well as impurity states. At temperatures below 30 K the transport is mediated by surface states while at higher temperatures activated transport via bulk channels sets in. The surface state conductivity and bulk band gaps can be tuned by the Sb-concentration and film thickness, respectively. For films as thin as 4 nm the surface state transport is strongly suppressed in contrast to Bi(111) films grown under identical conditions. The impurity channel is of intrinsic origin due to the growth and alloy formation process and turns out to be located at the buried interface.

  12. Monitoring Affect States during Effortful Problem Solving Activities

    Science.gov (United States)

    D'Mello, Sidney K.; Lehman, Blair; Person, Natalie

    2010-01-01

    We explored the affective states that students experienced during effortful problem solving activities. We conducted a study where 41 students solved difficult analytical reasoning problems from the Law School Admission Test. Students viewed videos of their faces and screen captures and judged their emotions from a set of 14 states (basic…

  13. Theoretical prediction of ion conductivity in solid state HfO2

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei; Chen Wen-Zhou; Sun Jiu-Yu; Jiang Zhen-Yi

    2013-01-01

    A theoretical prediction of ion conductivity for solid state HfO2 is carried out in analogy to ZrO2 based on the density functional calculation.Geometric and electronic structures of pure bulks exhibit similarity for the two materials.Negative formation enthalpy and negative vacancy formation energy are found for YSH (yttria-stabilized hafnia) and YSZ (yttriastabilized zirconia),suggesting the stability of both materials.Low activation energies (below 0.7 eV) of diffusion are found in both materials,and YSH's is a little higher than that of YSZ.In addition,for both HfO2 and ZrO2,the supercells with native oxygen vacancies are also studied.The so-called defect states are observed in the supercells with neutral and +1 charge native vacancy but not in the +2 charge one.It can give an explanation to the relatively lower activation energies of yttria-doped oxides and +2 charge vacancy supercells.A brief discussion is presented to explain the different YSH ion conductivities in the experiment and obtained by us,and we attribute this to the different ion vibrations at different temperatures.

  14. Slow conversions among subconductance states of cystic fibrosis transmembrane conductance regulator chloride channel.

    OpenAIRE

    Tao, T.; Xie, J; Drumm, M L; Zhao, J.; Davis, P B; Ma, J.

    1996-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel exhibits multiple subconductance states. To study the regulation of conductance states of the CFTR channel, we expressed the wild-type CFTR protein in HEK 293 cells, and isolated microsomal membrane vesicles for reconstitution studies in lipid bilayer membranes. A single CFTR channel had a dominant conductance of 7.8 pS (H), plus two sub-open states with conductances of approximately 6 pS (M) and 2.7 pS (L) in 200...

  15. 2008 LHC Open Days: Super(-conducting) events and activities

    CERN Multimedia

    2008-01-01

    Superconductivity will be one of the central themes of the programme of events and discovery activities of the forthcoming LHC Open Days on 5 and 6 April. Visitors will be invited to take part in a range of activities, experiments and exchanges all about this amazing aspect of the LHC project. Why superconductivity? Simply because it’s the principle on which the very operation of the LHC is based. At the heart of the LHC magnets lie 7000 kilometres of superconducting cables, each strand containing between 6000 and 9000 filaments of the superconducting alloy niobium-titanium in a copper coating. These cables, cooled to a temperature close to absolute zero, are able to conduct electricity without resistance. 12000 amp currents - an intensity some 30000 times greater than that of a 100 watt light bulb - pass through the cables of the LHC magnets.   Programme:   BLDG 163 (Saturday 5 and Sunday 6 April): See weird and wonderful experiments with your own eyes In the workshop where the 2...

  16. Inorganic Solid-State Electrolytes for Lithium Batteries: Mechanisms and Properties Governing Ion Conduction.

    Science.gov (United States)

    Bachman, John Christopher; Muy, Sokseiha; Grimaud, Alexis; Chang, Hao-Hsun; Pour, Nir; Lux, Simon F; Paschos, Odysseas; Maglia, Filippo; Lupart, Saskia; Lamp, Peter; Giordano, Livia; Shao-Horn, Yang

    2016-01-13

    This Review is focused on ion-transport mechanisms and fundamental properties of solid-state electrolytes to be used in electrochemical energy-storage systems. Properties of the migrating species significantly affecting diffusion, including the valency and ionic radius, are discussed. The natures of the ligand and metal composing the skeleton of the host framework are analyzed and shown to have large impacts on the performance of solid-state electrolytes. A comprehensive identification of the candidate migrating species and structures is carried out. Not only the bulk properties of the conductors are explored, but the concept of tuning the conductivity through interfacial effects-specifically controlling grain boundaries and strain at the interfaces-is introduced. High-frequency dielectric constants and frequencies of low-energy optical phonons are shown as examples of properties that correlate with activation energy across many classes of ionic conductors. Experimental studies and theoretical results are discussed in parallel to give a pathway for further improvement of solid-state electrolytes. Through this discussion, the present Review aims to provide insight into the physical parameters affecting the diffusion process, to allow for more efficient and target-oriented research on improving solid-state ion conductors.

  17. Bi-directional modulation of AMPA receptor unitary conductance by synaptic activity

    Directory of Open Access Journals (Sweden)

    Matthews Paul

    2004-11-01

    Full Text Available Abstract Background Knowledge of how synapses alter their efficiency of communication is central to the understanding of learning and memory. The most extensively studied forms of synaptic plasticity are long-term potentiation (LTP and its counterpart long-term depression (LTD of AMPA receptor-mediated synaptic transmission. In the CA1 region of the hippocampus, it has been shown that LTP often involves a rapid increase in the unitary conductance of AMPA receptor channels. However, LTP can also occur in the absence of any alteration in AMPA receptor unitary conductance. In the present study we have used whole-cell dendritic recording, failures analysis and non-stationary fluctuation analysis to investigate the mechanism of depotentiation of LTP. Results We find that when LTP involves an increase in unitary conductance, subsequent depotentiation invariably involves the return of unitary conductance to pre-LTP values. In contrast, when LTP does not involve a change in unitary conductance then depotentiation also occurs in the absence of any change in unitary conductance, indicating a reduction in the number of activated receptors as the most likely mechanism. Conclusions These data show that unitary conductance can be bi-directionally modified by synaptic activity. Furthermore, there are at least two distinct mechanisms to restore synaptic strength from a potentiated state, which depend upon the mechanism of the previous potentiation.

  18. 77 FR 38082 - Certain Activated Carbon from China; Notice of Commission Determination To Conduct a Full Five...

    Science.gov (United States)

    2012-06-26

    ... COMMISSION Certain Activated Carbon from China; Notice of Commission Determination To Conduct a Full Five... Activated Carbon From China AGENCY: United States International Trade Commission. ACTION: Notice. SUMMARY... whether revocation of the antidumping duty order on certain activated carbon from China would be likely...

  19. 20 CFR 661.207 - How does the State Board meet its requirement to conduct business in an open manner under the...

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false How does the State Board meet its requirement... State Governance Provisions § 661.207 How does the State Board meet its requirement to conduct business..., on a regular basis through open meetings, information about the activities of the State Board....

  20. Topological edge state with zero Hall conductivity in quasi-one dimensional system

    Directory of Open Access Journals (Sweden)

    Xiao-Shan Ye

    2016-09-01

    Full Text Available We explore the structure of the energy spectra of quasi-one dimensional (Q1D system subjected to spin-density-wave SDW states. The structure of the energy spectra opens energy gaps with Zeeman field. Theses gaps result in plateaus for the Quantum Hall conductivity which is associated with edge states. Different from the SSH Hofstadter model, here we show that there are a doublet of edge states contribution to zero Hall conductivity. These edge states are allowed for magnetic control of spin currents. The topological effects predicted here could be tested directly in organic conductors system.

  1. Topological edge state with zero Hall conductivity in quasi-one dimensional system

    Science.gov (United States)

    Ye, Xiao-Shan

    2016-09-01

    We explore the structure of the energy spectra of quasi-one dimensional (Q1D) system subjected to spin-density-wave SDW states. The structure of the energy spectra opens energy gaps with Zeeman field. Theses gaps result in plateaus for the Quantum Hall conductivity which is associated with edge states. Different from the SSH Hofstadter model, here we show that there are a doublet of edge states contribution to zero Hall conductivity. These edge states are allowed for magnetic control of spin currents. The topological effects predicted here could be tested directly in organic conductors system.

  2. How Phosphorylation and ATPase Activity Regulate Anion Flux though the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).

    Science.gov (United States)

    Zwick, Matthias; Esposito, Cinzia; Hellstern, Manuel; Seelig, Anna

    2016-07-08

    The cystic fibrosis transmembrane conductance regulator (CFTR, ABCC7), mutations of which cause cystic fibrosis, belongs to the ATP-binding cassette (ABC) transporter family and works as a channel for small anions, such as chloride and bicarbonate. Anion channel activity is known to depend on phosphorylation by cAMP-dependent protein kinase A (PKA) and CFTR-ATPase activity. Whereas anion channel activity has been extensively investigated, phosphorylation and CFTR-ATPase activity are still poorly understood. Here, we show that the two processes can be measured in a label-free and non-invasive manner in real time in live cells, stably transfected with CFTR. This study reveals three key findings. (i) The major contribution (≥90%) to the total CFTR-related ATP hydrolysis rate is due to phosphorylation by PKA and the minor contribution (≤10%) to CFTR-ATPase activity. (ii) The mutant CFTR-E1371S that is still conductive, but defective in ATP hydrolysis, is not phosphorylated, suggesting that phosphorylation requires a functional nucleotide binding domain and occurs in the post-hydrolysis transition state. (iii) CFTR-ATPase activity is inversely related to CFTR anion flux. The present data are consistent with a model in which CFTR is in a closed conformation with two ATPs bound. The open conformation is induced by ATP hydrolysis and corresponds to the post-hydrolysis transition state that is stabilized by phosphorylation and binding of chloride channel potentiators.

  3. DEPTH CONTINUOUS HYDRAULIC CONDUCTIVITY PROFILING USING AN ACTIVE SOURCE PENETROMETER

    Science.gov (United States)

    Fitzgerald, M.; Elsworth, D.

    2009-12-01

    A method is developed to recover depth-continuous hydraulic conductivity profiles of an unconsolidated saturated aquifer using an active source penetrometer, the Hydraulic Profiling Tool (HPT). The tool yields estimates of K through continuous injection of fluid in the subsurface from a small port on the probe shaft while controlled measurements of net applied fluid pressure required to maintain a specified flow rate (typically 350 mL/min) are recorded. The tool gathers these data of flow rate and measured applied pressure during halted and constant-rate penetration (typically 2cm/sec) of the probe. The analysis is developed in two parts, first to explore the interplay between advective effects controlled by penetration rate and secondly flow volume effects controlled by the targeted flow rate. These two effects are analyzed through their respective influence on the measured applied pressure response in ΔP/σv’-Q/ΔP space, which shows a linear relationship for the flow rate to applied pressure response when Q/ΔP > 1 and when Q/ΔP 1. The analysis shows that penetration rate does not significantly influence the applied pressure response at the tested penetration rates (0 ≤ U(cm/s)≤ 4). The targeted applied flow rate does however influence the applied pressure response as flow rates less than ~300 mL/min show a scattering of the data in ΔP/σv’-Q/ΔP space, where above 300 mL/min the data begins to form a linear response. A targeted flow rate of QT = 400mL/min is suggested as a suitable flow rate based on this analysis. Measurements of hydraulic conductivity are then obtained for the HPT data through the derivation of an equation based on a recast form of Darcy’s law where considerations of the flow geometry as K = (QHPT/ΔP)(δw/πΦ). K profiles obtained for the HPT system are then compared against K profiles obtained from an independent method (PSU permeameter) and yield a good correlation between the two methods.

  4. Enhancing the Electronic Conductivity of Vanadium-tellurite Glasses by Tuning the Redox State

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Yue, Yuanzheng

    . In this work we vary the redox state of a given vanadium tellurite system by performing post heat-treatment in controlled atmosphere. This process is in theory not limited only to varying electronic conductivity, but also varying the glass structure, and hence, changing properties of the glasses, e.g, thermal...... and mechanical properties. Finally we give insight into the relation between the redox state and electronic conductivity....

  5. A Study of Master's Degrees in Orchestral Conducting in the United States

    Science.gov (United States)

    St. John, Brian Allen

    2010-01-01

    In order to learn to be an orchestra conductor in the United States of America, students often begins their formal education by seeking to earn a master's degree in orchestral conducting. This project compiled a listing of American universities which offer a master's degree in orchestral conducting and categorized the component parts of their…

  6. Voltage-dependent conductance states of a single-molecule junction

    DEFF Research Database (Denmark)

    Wang, Y F; Néel, N; Kröger, J

    2012-01-01

    Ag–Sn-phthalocyanine–Ag junctions are shown to exhibit three conductance states. While the junctions are conductive at low bias, their impedance drastically increases above a critical bias. Two-level fluctuations occur at intermediate bias. These characteristics may be used to protect a nanoscale...... circuit. Further experiments along with calculations reveal that the self-limiting conductance of the junctions is due to reversible changes of the junction geometry....

  7. STUDIES OF A.C. CONDUCTIVITY OF POLY(VINYL BORATE) AND ITS CALCIUM DERIVATIVE IN SOLID STATE

    Institute of Scientific and Technical Information of China (English)

    Prafulla Chetri; Neelotpal Sen Sarma; Narendra Nath Dass

    2008-01-01

    An attempt has been made in the present work to prepare poly(vinyl borate), PVBO and its calcium derivative by homogeneous esterification of PVA with boric acid in non-aqueous medium in the presence of a catalyst ethyl nitrate dimethyl sulfoxide. The compounds were characterized by IR and 1H-NMR spectra. Conductivities were determined from 30℃ to 90℃ in solid state within a frequency range of 42 Hz to 100 kHz. The compounds so formed showed ionic conductivity and their conductivities were dependent on frequencies used. It is found that the addition of Ca2+ ion increases the ionic conductivity of PVBO appreciably. The conductivity of PVBO-Ca increases rapidly after 50℃. The total ionic transport number and activation energy of the copolymers were also determined.

  8. Report on activities conducted at Arapaho National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the work done at Arapaho NWR to collect prairie dogs and prairie dog fleas, in order to conduct a laboratory study of flea control methods....

  9. Absolute Steady-State Thermal Conductivity Measurements by Use of a Transient Hot-Wire System

    OpenAIRE

    Roder, Hans M.; Perkins, Richard A.; Laesecke, Arno; Nieto de Castro, Carlos A.

    2000-01-01

    A transient hot-wire apparatus was used to measure the thermal conductivity of argon with both steady-state and transient methods. The effects of wire diameter, eccentricity of the wire in the cavity, axial conduction, and natural convection were accounted for in the analysis of the steady-state measurements. Based on measurements on argon, the relative uncertainty at the 95 % level of confidence of the new steady-state measurements is 2 % at low densities. Using the same hot wires, the relat...

  10. Absolute Steady-State Thermal Conductivity Measurements by Use of a Transient Hot-Wire System.

    Science.gov (United States)

    Roder, H M; Perkins, R A; Laesecke, A; Nieto de Castro, C A

    2000-01-01

    A transient hot-wire apparatus was used to measure the thermal conductivity of argon with both steady-state and transient methods. The effects of wire diameter, eccentricity of the wire in the cavity, axial conduction, and natural convection were accounted for in the analysis of the steady-state measurements. Based on measurements on argon, the relative uncertainty at the 95 % level of confidence of the new steady-state measurements is 2 % at low densities. Using the same hot wires, the relative uncertainty of the transient measurements is 1 % at the 95 % level of confidence. This is the first report of thermal conductivity measurements made by two different methods in the same apparatus. The steady-state method is shown to complement normal transient measurements at low densities, particularly for fluids where the thermophysical properties at low densities are not known with high accuracy.

  11. Slow conversions among subconductance states of cystic fibrosis transmembrane conductance regulator chloride channel.

    Science.gov (United States)

    Tao, T; Xie, J; Drumm, M L; Zhao, J; Davis, P B; Ma, J

    1996-02-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel exhibits multiple subconductance states. To study the regulation of conductance states of the CFTR channel, we expressed the wild-type CFTR protein in HEK 293 cells, and isolated microsomal membrane vesicles for reconstitution studies in lipid bilayer membranes. A single CFTR channel had a dominant conductance of 7.8 pS (H), plus two sub-open states with conductances of approximately 6 pS (M) and 2.7 pS (L) in 200 mM KCl with 1 mM MgCl2 (intracellular) and 50 mM KCl with no MgCl2 (extracellular), with pH maintained at 7.4 by 10 mM HEPES-Tris on both sides of the channel. In 200 mM KCl, both H and L states could be measured in stable single-channel recordings, whereas M could not. Spontaneous transitions between H and L were slow; it took 4.5 min for L-->H, and 3.2 min for H-->L. These slow conversions among subconductance states of the CFTR channel were affected by extracellular Mg; in the presence of millimolar Mg, the channel remained stable in the H state. Similar phenomena were also observed with endogenous CFTR channels in T84 cells. In high-salt conditions (1.5 M KCl), all three conductance states of the expressed CFTR channel, 12.1 pS, 8.2 pS, and 3.6 pS, became stable and seemed to gate independently from each other. The existence of multiple stable conductance states associated with the CFTR channel suggests two possibilities: either a single CFTR molecule can exist in multiple configurations with different conductance values, or the CFTR channel may contain multimers of the 170-kDa CFTR protein, and different conductance states are due to different aggregation states of the CFTR protein.

  12. Temperature dependence of dc electrical conductivity of activated carbon-metal oxide nanocomposites. Some insight into conduction mechanisms

    Science.gov (United States)

    Barroso-Bogeat, Adrián; Alexandre-Franco, María; Fernández-González, Carmen; Sánchez-González, José; Gómez-Serrano, Vicente

    2015-12-01

    From a commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites are prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in inert atmosphere. The temperature-dependent dc electrical conductivity of AC and the as-prepared nanocomposites is measured from room temperature up to ca. 200 °C in air atmosphere by the four-probe method. The decrease in conductivity for the hybrid materials as compared to AC is the result of a complex interplay between several factors, including not only the intrinsic conductivity, crystallite size, content and chemical nature of the supported nanoparticles, which ultimately depend on the precursor and heat treatment temperature, but also the adsorption of oxygen and water from the surrounding atmosphere. The conductivity data are discussed in terms of a thermally activated process. In this regard, both AC and the prepared nanocomposites behave as semiconductors, and the temperature-dependent conductivity data have been interpreted on the basis of the classical model proposed by Mott and Davis. Because of its high content of heteroatoms, AC may be considered as a heavily doped semiconductor, so that conduction of thermally excited carriers via acceptor or donor levels is expected to be the dominant mechanism. The activation energies for the hybrid materials suggest that the supported metal oxide nanoparticles strongly modify the electronic band structure of AC by introducing new trap levels in different positions along its band gap. Furthermore, the thermally activated conduction process satisfies the Meyer-Neldel rule, which is likely connected with the shift of the Fermi level due to the introduction of the different metal oxide nanoparticles in the AC matrix.

  13. Calcium-activated potassium conductance noise in snail neurons.

    Science.gov (United States)

    Westerfield, M; Lux, H D

    1982-11-01

    Current fluctuations were measured in small, 3-6 micrometers-diameter patches of soma membrane in bursting neurons of the snail, Helix pomatia. The fluctuations dramatically increased in magnitude with depolarization of the membrane potential under voltage clamp conditions. Two components of conductance noise were identified in the power spectra calculated from the membrane currents. One component had a corner frequency which increased with depolarization. This component was blocked by intracellular injection of TEA and was relatively insensitive to extracellular calcium levels (as long as the total number of effective divalent cations remained constant). It was identified as fluctuations of the voltage-dependent component of delayed outward current. The second component of conductance noise had a corner frequency which decreased with depolarization. It was relatively unaffected by TEA injection and was reversibly blocked by substitution of extracellular calcium with magnesium, cobalt, or nickel. This second component of noise was identified as fluctuations of the calcium-dependent potassium current. The results suggest that the two components of delayed outward current are conducted through physically distinct channels.

  14. Characterization of polyester films used in capacitors. 1: Transient and steady-state conductivity

    Science.gov (United States)

    Thielen, A.; Niezette, J.; Feyder, G.; Vanderschueren, J.

    1994-10-01

    Charging and discharging currents flowing through polyethylene terephthalate (PET) ultrathin films (1.5 - 12 micrometers) were measured by the use of a two-electrode configuration involving opposite lateral contacts. A study of the influence of electrification time, applied electric field, film thickness, nature of electrodes, and water content was carried out on both transient and steady-state conduction. The transient behavior can be interpreted in terms of dipolar orientation and relaxation processes while steady-state conductivity can be mainly accounted for in terms of Schottky emission. A comparison between PET and polyethylene naphthalate films is also reported.

  15. Making Glasses Conduct: Electrochemical Doping of Redox-Active Polymer Thin Films

    Science.gov (United States)

    Boudouris, Bryan

    Optoelectronically-active macromolecules have been established as promising materials in myriad organic electronic applications (e.g., organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices). To date, however, the majority of the work surrounding these materials has focused on materials with a great deal of conjugation along their macromolecular backbones and with varying degrees of crystalline structure. Here, we describe an emerging class of macromolecular charge conductors, radical polymers, that: (1) do not contain conjugation and (2) are completely amorphous glasses. Radical polymers contain non-conjugated macromolecular backbones and stable radical sites along the side chains of the electronically-active materials. In contrast to conjugated polymer systems, these materials conduct charge in the solid state through oxidation-reduction (redox) reactions along these pendant groups. Specifically, we demonstrate that controlling the chemical functionality of the pendant groups and the molecular mobility of the macromolecular backbones significantly impacts the charge transport ability of the pristine (i.e., not doped) radical polymers species. Through proper control of these crucial parameters, we show that radical polymers can have electrical conductivity and charge mobility values on par with commonly-used conjugated polymers. Importantly, we also highlight the ability to dope radical polymers with redox-active small molecule species. This doping, in turn, increases the electrical conductivity of the glassy radical polymer thin films in a manner akin to what is observed in traditional conjugated polymer systems. In this way, we establish a means by which to fabricate optically-transparent and colorless thin film glasses capable of conducting charge in a rather rapid manner. We anticipate that these fundamental insights will prove crucial in developing new transparent conducting layers for future electronic applications.

  16. Low Energy of Activation Lithium-Ion Conducting Channel

    Science.gov (United States)

    2010-09-22

    Between Gold Electrodes (710 µm Thick; 1.6 cm2) 1/T (K) Electrochem. and Solid-State Letters, 8 (5), E45-E48 (2005) ECS Transactions , 25 (36) 163...167 (2010) Ea = 0.038 eV 11 Nyquist Plots of SS/Thin Film Li2Pc Cast Onto an MnO2 Cathode/SS at -50, -25, 0, +25, and 50°C ECS Transactions , 25

  17. Electrical conductivity of activated carbon-metal oxide nanocomposites under compression: a comparison study.

    Science.gov (United States)

    Barroso-Bogeat, A; Alexandre-Franco, M; Fernández-González, C; Macías-García, A; Gómez-Serrano, V

    2014-12-01

    From a granular commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites were prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in an inert atmosphere. Here, the electrical conductivity of the resulting products was studied under moderate compression. The influence of the applied pressure, sample volume, mechanical work, and density of the hybrid materials was thoroughly investigated. The DC electrical conductivity of the compressed samples was measured at room temperature by the four-probe method. Compaction assays suggest that the mechanical properties of the nanocomposites are largely determined by the carbon matrix. Both the decrease in volume and the increase in density were relatively small and only significant at pressures lower than 100 kPa for AC and most nanocomposites. In contrast, the bulk electrical conductivity of the hybrid materials was strongly influenced by the intrinsic conductivity, mean crystallite size, content and chemical nature of the supported phases, which ultimately depend on the metal oxide precursor and heat treatment temperature. The supported nanoparticles may be considered to act as electrical switches either hindering or favouring the effective electron transport between the AC cores of neighbouring composite particles in contact under compression. Conductivity values as a rule were lower for the nanocomposites than for the raw AC, all of them falling in the range of semiconductor materials. With the increase in heat treatment temperature, the trend is toward the improvement of conductivity due to the increase in the crystallite size and, in some cases, to the formation of metals in the elemental state and even metal carbides. The patterns of variation of the electrical conductivity with pressure and mechanical work were slightly similar, thus suggesting the predominance of the pressure

  18. The activation energy of conductivity in organic solids and liquids in relation to the cohesive energy density

    Science.gov (United States)

    Vijh, A. K.

    The study of Gutmann and Keyzer (1980) of the possible existence of a relationship between solid-state cohesion and the band gaps of binary organic semiconductors is pursued. It is found that Vijh's equation for inorganic semiconductors has an analog that is valid for all organic semiconductors (molecular solids, liquids, monomeric polymers and molten crystals) except those in which either protonic conduction predominates or some structural/configurational considerations leading to anomalously low solid-state cohesion are present. For the data reported by Gutmann and Keyzer, a relation is given for the activation energy for dark conduction. It is pointed out that the conceptual foundation for Vijh's equation and this relation is the same; that is, higher solid-state cohesion is reflected in high magnitudes of the band gap and the activation energy for dark conduction.

  19. Understanding Electrical Conduction States in WO3 Thin Films Applied for Resistive Random-Access Memory

    Science.gov (United States)

    Ta, Thi Kieu Hanh; Pham, Kim Ngoc; Dao, Thi Bang Tam; Tran, Dai Lam; Phan, Bach Thang

    2016-05-01

    The electrical conduction and associated resistance switching mechanism of top electrode/WO3/bottom electrode devices [top electrode (TE): Ag, Ti; bottom electrode (BE): Pt, fluorine-doped tin oxide] have been investigated. The direction of switching and switching ability depended on both the top and bottom electrode material. Multiple electrical conduction mechanisms control the leakage current of such switching devices, including trap-controlled space-charge, ballistic, Ohmic, and Fowler-Nordheim tunneling effects. The transition between electrical conduction states is also linked to the switching (SET-RESET) process. This is the first report of ballistic conduction in research into resistive random-access memory. The associated resistive switching mechanisms are also discussed.

  20. Hopping conduction via highly localized impurity states of indium in PbTe and its solid solutions. Review

    CERN Document Server

    Ravich, Y I

    2002-01-01

    Results of experimental investigation of the transport phenomena in PbTe and Pb sub 1 sub - sub x Sn sub x Te solid solutions with high contents of In impurity (up to 20 at %) at temperatures up to 400 K have been considered. An analysis of the experimental data has been made on the base of an idea of hopping conductivity via highly localized impurity states creates by indium atoms. The temperature dependences of transport coefficients unusual for the IV-VI-type semiconductors, the change of sing of the thermoelectromotive force at negative Hall coefficient, the positive Nernst-Ettingshausen coefficient are explained. The activation energy of the hoping conductivity, characterizing discrepancy between impurity energy levels the effective wave function radius and the density of localized states as the energy function are found experimentally

  1. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

    DEFF Research Database (Denmark)

    Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W

    2012-01-01

    Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic......(m) -fluctuations and conductance observed experimentally during functional network activity leave little room for intrinsic conductance to contribute. Even without intrinsic conductances the variance in V(m) -fluctuations can only be explained by a high degree of correlated firing among presynaptic neurons....... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...

  2. Electrochemical Switching of Conductance with Diarylethene-Based Redox-Active Polymers

    DEFF Research Database (Denmark)

    Logtenberg, Hella; van der Velde, Jasper H. M.; de Mendoza, Paula;

    2012-01-01

    Reversible switching of conductance using redox triggered switching of a polymer-modified electrode is demonstrated. A bifunctional monomer comprising a central electroswitchable core and two bithiophene units enables formation of a film through anodic electropolymerization. The conductivity...... of the polymer can be switched electrochemically in a reversible manner by redox triggered opening and closing of the diarylethene unit. In the closed state, the conductivity of the modified electrode is higher than in the open state....

  3. Magnetic and nonmagnetic doping dependence of the conducting surface states in Sm B6

    Science.gov (United States)

    Kang, B. Y.; Min, Chul-Hee; Lee, S. S.; Song, M. S.; Cho, K. K.; Cho, B. K.

    2016-10-01

    Kondo insulator Sm B6 has attracted attention because it can realize new topological phenomena driven by the interplay between strong correlation effect and topology. However, its topological nature is still under debate. To examine the topological aspect, we demonstrate the nonmagnetic La and magnetic Ce doping dependence of the resistance of Sm B6 . Moreover, the resistance ratios of different thicknesses are analyzed to confirm the surface contribution. Lightly doped La samples show a purely conducting surface region at low temperature, whereas the lightly doped Ce samples do not have any conducting region at low temperature. Furthermore, based on the analysis of the electrical transport data of S m1 -xL axB6 (0.0 ≤x ≤1.0 ), an electronic phase diagram was found, composed of four regions: region I (0.0 ≤x ≤0.06 ), II (0.1 ≤x ≤0.15 ), III (x ≈0.2 ) , and IV (0.25 ≤x ≤1.0 ). Region I is characterized by the presence of conducting surface states, region II is characterized by the insulating phase due to the d -f hybridization gap without the conducting surface state, region III is characterized by the disappearance of the d -f hybridization gap and the existence of valence fluctuation, and region IV is a typical metallic state.

  4. Transition from spin accumulation into interface states to spin injection in silicon and germanium conduction bands

    Science.gov (United States)

    Jain, Abhinav; Rojas-Sanchez, Juan-Carlos; Cubukcu, Murat; Peiro, Julian; Le Breton, Jean-Christophe; Vergnaud, Céline; Augendre, Emmanuel; Vila, Laurent; Attané, Jean-Philippe; Gambarelli, Serge; Jaffrès, Henri; George, Jean-Marie; Jamet, Matthieu

    2013-04-01

    Electrical spin injection into semiconductors paves the way for exploring new phenomena in the area of spin physics and new generations of spintronic devices. However the exact role of interface states in the electrical spin injection mechanism from a magnetic tunnel junction into a semiconductor is still under debate. Here we demonstrate a clear transition from spin accumulation into interface states to spin injection in the conduction band of n-Si and n-Ge using a CoFeB/MgO tunnel contact. We observe spin signal amplification at low temperature due to spin accumulation into interface states followed by a clear transition towards spin injection in the conduction band from approximately 150 K up to room temperature. In this regime, the spin signal is reduced down to a value compatible with the standard spin diffusion model. More interestingly, in the case of germanium, we demonstrate a significant modulation of the spin signal by applying a back-gate voltage to the conduction channel. We also observe the inverse spin Hall effect in Ge by spin pumping from the CoFeB electrode. Both observations are consistent with spin accumulation in the Ge conduction band.

  5. Determination of density of states, conduction mechanisms and dielectric properties of nickel disulfide nanoparticles

    Directory of Open Access Journals (Sweden)

    Arifa Jamil

    2016-05-01

    Full Text Available Temperature and frequency dependent ac electrical measurements were used to explore density of states, conduction mechanisms and dielectric properties of nickel disulfide (NiS2 nanoparticles. The NiS2 nanoparticles were prepared by conventional one step solid state reaction method at 250 °C. X-ray diffraction (XRD confirmed cubic phase of prepared nanoparticles. Scanning electron microscope (SEM images revealed presence of irregular shaped nanoparticles as small as 50 nm. The ac electrical measurements were carried out from 300 K to 413 K. Two depressed semicircular arcs from 20 Hz to 2 MHz showed presence of bulk and grain boundary phases in NiS2 nanoparticles at all temperatures. Small polaron hopping conduction from 300 K to 393 K and correlated barrier hopping conduction mechanism at temperatures higher than 393 K was observed. High value of density of states (of the order of 1024 eV−1cm−3 was calculated from ac conductivity. At low frequencies high values (of the order of 104-107 of real part of dielectric constant (ε′ were observed at different temperatures. These observations suggest that NiS2 nanoparticles may find applications in electronic devices.

  6. 30 CFR 285.614 - When may I begin conducting activities under my approved SAP?

    Science.gov (United States)

    2010-07-01

    ... approved SAP? 285.614 Section 285.614 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE... Plans and Information Requirements Activities Under An Approved Sap § 285.614 When may I begin conducting activities under my approved SAP? (a) You may begin conducting the activities approved in your...

  7. SEMICONDUCTOR DEVICES Physical effect on transition from blocking to conducting state of barrier-type thyristor

    Science.gov (United States)

    Hairong, Li; Siyuan, Li

    2010-12-01

    The transition of the barrier-type thyristor (BTH) from blocking to conducting-state occurs between two entirely contrary physical states with great disparity in nature. The physical effects and mechanisms of the transition are studied in depth. The features of the transition snapback point are analyzed in detail. The transition snapback point has duality and is just the position where the barrier is flattened. It has a significant influence on the capture cross-section of the hole and high-level hole lifetime, resulting in the device entering into deep base conductance modulation. The physical nature of the negative differential resistance segment I-V characteristics is studied. It is testified by using experimental data that the deep conductance modulation is the basic feature and the linchpin of the transition process. The conditions and physical mechanisms of conductance modulation are investigated. The related physical subjects, including the flattening of the channel barrier, the buildup of the double injection, the formation of the plasma, the realization of the high-level injection, the elimination of the gate junction depletion region, the deep conductance modulation, and the increase in the hole's lifetime are all discussed in this paper.

  8. Activated carbon is an electron-conducting amphoteric ion adsorbent

    CERN Document Server

    Biesheuvel, P M

    2015-01-01

    Electrodes composed of activated carbon (AC) particles can desalinate water by ion electrosorption. To describe ion electrosorption mathematically, accurate models are required for the structure of the electrical double layers (EDLs) that form within electrically charged AC micropores. To account for salt adsorption also in uncharged ACs, an "attraction term" was introduced in modified Donnan models for the EDL structure in ACs. Here it will be shown how instead of using an attraction term, chemical information of the surface structure of the carbon-water interface in ACs can be used to construct an alternative EDL model for ACs. This EDL model assumes that ACs contain both acidic groups, for instance due to carboxylic functionalities, and basic groups, due to the adsorption of protons to the carbon basal planes. As will be shown, this "amphoteric Donnan" model accurately describes various data sets for ion electrosorption in ACs, for solutions of NaCl, of CaCl2, and mixtures thereof, as function of the exter...

  9. Observation of Andreev bound states at spin-active interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Detlef; Wolf, Michael Johannes [KIT, Institut fuer Nanotechnologie (Germany); Huebler, Florian [KIT, Institut fuer Nanotechnologie (Germany); KIT, Institut fuer Festkoerperphysik (Germany); Loehneysen, Hilbert von [KIT, Institut fuer Festkoerperphysik (Germany); KIT, Physikalisches Institut (Germany)

    2013-07-01

    We report on high-resolution differential conductance experiments on nanoscale superconductor/ferromagnet tunnel junctions with ultra-thin oxide tunnel barriers. We observe subgap conductance features which are symmetric with respect to bias, and shift according to the Zeeman energy with an applied magnetic field. These features can be explained by resonant transport via Andreev bound states induced by spin-active scattering at the interface. From the energy and the Zeeman shift of the bound states, both the magnitude and sign of the spin-dependent interfacial phase shifts between spin-up and spin-down electrons can be determined. These results contribute to the microscopic insight into the triplet proximity effect at spin-active interfaces.

  10. Large-conductance Ca2+-activated potassium channels in secretory neurons.

    Science.gov (United States)

    Lara, J; Acevedo, J J; Onetti, C G

    1999-09-01

    Large-conductance Ca2+-activated K+ channels (BK) are believed to underlie interburst intervals and contribute to the control of hormone release in several secretory cells. In crustacean neurosecretory cells, Ca2+ entry associated with electrical activity could act as a modulator of membrane K+ conductance. Therefore we studied the contribution of BK channels to the macroscopic outward current in the X-organ of crayfish, and their participation in electrophysiological activity, as well as their sensitivity toward intracellular Ca2+, ATP, and voltage, by using the patch-clamp technique. The BK channels had a conductance of 223 pS and rectified inwardly in symmetrical K+. These channels were highly selective to K+ ions; potassium permeability (PK) value was 2.3 x 10(-13) cm(3) s(-1). The BK channels were sensitive to internal Ca2+ concentration, voltage dependent, and activated by intracellular MgATP. Voltage sensitivity (k) was approximately 13 mV, and the half-activation membrane potentials depended on the internal Ca2+ concentration. Calcium ions (0.3-3 microM) applied to the internal membrane surface caused an enhancement of the channel activity. This activation of BK channels by internal calcium had a KD(0) of 0.22 microM and was probably due to the binding of only one or two Ca2+ ions to the channel. Addition of MgATP (0.01-3 mM) to the internal solution increased steady state-open probability. The dissociation constant for MgATP (KD) was 119 microM, and the Hill coefficient (h) was 0.6, according to the Hill analysis. Ca2+-activated K+ currents recorded from whole cells were suppressed by either adding Cd2+ (0.4 mM) or removing Ca2+ ions from the external solution. TEA (1 mM) or charybdotoxin (100 nM) blocked these currents. Our results showed that both BK and K(ATP) channels are present in the same cell. Even when BK and K(ATP) channels were voltage dependent and modulated by internal Ca2+ and ATP, the profile of sensitivity was quite different for each kind

  11. Effect of the edge states on the conductance and thermopower in zigzag phosphorene nanoribbons

    Science.gov (United States)

    Ma, R.; Geng, H.; Deng, W. Y.; Chen, M. N.; Sheng, L.; Xing, D. Y.

    2016-09-01

    We study numerically the effect of the edge states on the conductance and thermopower in zigzag phosphorene nanoribbons (ZPNRs) based on the tight-binding model and the scattering-matrix method. It is interesting to find that the band dispersion, conductance, and thermopower can be modulated by applying a bias voltage and boundary potentials to the two layers of the ZPNRs. Under a certain bias voltage, the twofold-degenerate quasi-flat-edge bands split perfectly. The conductance can be switched off, and the thermopower around zero energy increases. In addition, when only the boundary potential of the top layer or bottom layer is adjusted, only one edge band bends and merges into the bulk band. The first conductance plateau is strongly decreased to e2/h around zero energy. In particular, when the two boundary potentials are adjusted, all the edge bands bend and fully merge into the bulk band, and the bulk energy gap is maximized. More interestingly, a pronounced conductance plateau with G =0 is found around zero energy, which is attributable to the opening of the bulk energy gap between the valence and conduction bands. Meanwhile, the thermopower can be enhanced more than twice compared to that of the perfect ZPNRs. The large magnitude of thermopower is ascribed to the appearance of the bulk energy gap around zero energy. Our results show that the modulated ZPNRs are more reliable in a thermoelectric application.

  12. Equation of State, Occupation Probabilities and Conductivities in the Average Atom Purgatorio Code

    Energy Technology Data Exchange (ETDEWEB)

    Sterne, P

    2006-12-22

    We report on recent developments with the Purgatorio code, a new implementation of Liberman's Inferno model. This fully relativistic average atom code uses phase shift tracking and an efficient refinement scheme to provide an accurate description of continuum states. The resulting equations of state accurately represent the atomic shell-related features which are absent in Thomas-Fermi-based approaches. We discuss various representations of the exchange potential and some of the ambiguities in the choice of the effective charge Z* in average atom models, both of which affect predictions of electrical conductivities and radiative properties.

  13. Dynamic tunneling force microscopy for characterizing electronic trap states in non-conductive surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.; Williams, C. C., E-mail: clayton@physics.utah.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States)

    2015-09-15

    Dynamic tunneling force microscopy (DTFM) is a scanning probe technique for real space mapping and characterization of individual electronic trap states in non-conductive films with atomic scale spatial resolution. The method is based upon the quantum mechanical tunneling of a single electron back and forth between a metallic atomic force microscopy tip and individual trap states in completely non-conducting surface. This single electron shuttling is measured by detecting the electrostatic force induced on the probe tip at the shuttling frequency. In this paper, the physical basis for the DTFM method is unfolded through a physical model and a derivation of the dynamic tunneling signal as a function of several experimental parameters is shown. Experimental data are compared with the theoretical simulations, showing quantitative consistency and verifying the physical model used. The experimental system is described and representative imaging results are shown.

  14. Estimating saturated hydraulic conductivity and air permeability from soil physical properties using state-space analysis

    DEFF Research Database (Denmark)

    Poulsen, Tjalfe; Møldrup, Per; Nielsen, Don

    2003-01-01

    field were used. Multiple regression and ARIMA models yielded similar prediction accuracy, whereas state-space models generally gave significantly higher accuracy. State-space modeling suggested K-S at a given location could be predicted using nearby values of K-S, k(a100) and air-filled porosity......Estimates of soil hydraulic conductivity (K) and air permeability (k(a)) at given soil-water potentials are often used as reference points in constitutive models for K and k(a) as functions of moisture content and are, therefore, a prerequisite for predicting migration of water, air, and dissolved...... and gaseous chemicals in the vadose zone. In this study, three modeling approaches were used to identify the dependence of saturated hydraulic conductivity (K-S) and air permeability at -100 cm H2O soil-water potential (k(a100)) on soil physical properties in undisturbed soil: (i) Multiple regression, (ii...

  15. Cross-correlations in high-conductance states of a model cortical network

    DEFF Research Database (Denmark)

    Hertz, John

    2010-01-01

    (dansk abstrakt findes ikke) Neuronal firing correlations are studied using simulations of a simple network model for a cortical column in a high-conductance state with dynamically balanced excitation and inhibition.  Although correlations between individual pairs of neurons exhibit considerable...... heterogeneity, population averages show systematic behavior. When the network is in a stationary state, the average correlations are generically small: correlation coefficients are of order 1/N, where N is the number of neurons in the network. However, when the input to the network varies strongly in time, much...... larger values are found. In this situation, the network is out of balance, and the synaptic conductance is low, at times when the strongest firing occurs.  However, examination of the correlation functions of synaptic currents reveals that after these bursts, balance is restored within a few ms...

  16. A single Jahn-Teller active electron as a multi-throw multipolar conductance switch

    Science.gov (United States)

    Rios, Laura; Lee, Joonhee; Tallarida, Nicholas; Apkarian, V. Ara

    2014-03-01

    The final limit in miniaturization of molecular electronics may be regarded as functionality attained through the manipulation of a single electron and no other moving parts. We demonstrate this limit, in the form of a three-throw, bipolar, bistable conductance switch realized by manipulating a Jahn-Teller (JT) active electron on a single zinc etioporphyrin radical anion (ZnEtio-) molecule at the double barrier junction of a cryogenic scanning tunneling microscope (STM). The vibronic JT potential determines the anisotropy of the topography. At resonance, the topography undergoes bistable switching and electroluminescence. Their difference map yields the wiring diagram of the conductance switch; and the spatially-resolved switching kinetics within the molecule yields functional maps for controlling the frequency/amplitude of the switch. Through detailed balance of spontaneous on/off rates, the energy difference between the states leading to the observed bistability is determined as ~ 1 meV. We obtain a consistent interpretation of all observations by assigning the two states to Kramer's pair, with degeneracy broken due to pseudo-rotation on the JT vector potential, where the switching is understood as spin-flipping driven by scattering of tunneling electrons at resonance. Funding by NSF CCI Chemistry at the Space-Time Limit, CHE-082913.

  17. Measurement of the in-plane thermal conductivity by steady-state infrared thermography

    CERN Document Server

    Greppmair, Anton; Saxena, Nitin; Gerstberger, Caroline; Müller-Buschbaum, Peter; Stutzmann, Martin; Brandt, Martin S

    2016-01-01

    We demonstrate a simple and quick method for the measurement of the in-plane thermal conductance of thin films via steady-state IR thermography. The films are suspended above a hole in an opaque substrate and heated by a homogeneous visible light source. The temperature distribution of the thin films is captured via infrared microscopy and fitted to the analytical expression obtained for the specific hole geometry in order to obtain the in-plane thermal conductivity. For thin films of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate post-treated with ethylene glycol and of polyimide we find conductivities of 1.0 W/mK and 0.4 W/mK at room temperature, respectively. These results are in very good agreement with literature values, validating the method developed.

  18. Non-linear conductivity of NbS{sub 3} in pressure induced metal state

    Energy Technology Data Exchange (ETDEWEB)

    Dizhur, Eugene; Kostyleva, Irina; Voronovskii, Anatoly [Institute for High Pressure Physics of RAS, Kaluzhskoe sh. 14, 142190 Troitsk (Russian Federation); Zaitzev-Zotov, Sergey [Institute of Radioengineering and Electronics of the RAS, Mokhovaya ul. 11, 125009 Moscow (Russian Federation)

    2011-05-15

    Temperature and voltage dependencies of conduction of a quasi-one-dimensional conductor NbS{sub 3} after its transition into a metallic state has been studied at pressures higher than 6 GPa. The differential resistance R = dV /dI measured at small biases (the electric field E below 2 V/cm) demonstrate a considerable growth upon cooling below 20 K accompanied by appearance of the non-linear conduction. Both the growth and nonlinear conduction disappear at E > 3 V/cm or when the temperature exceeds 40 K. A narrow dip visible only at much smaller fields E < 20 mV/cm is superimposed over that nonlinear background when cooling below 3.7 K. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. A steady-state high-temperature method for measuring thermal conductivity of refractory materials

    Science.gov (United States)

    Manzolaro, M.; Corradetti, S.; Andrighetto, A.; Ferrari, L.

    2013-05-01

    A new methodology and an instrumental setup for the thermal conductivity estimation of isotropic bulk graphite and different carbides at high temperatures are presented. The method proposed in this work is based on the direct measurement of temperature and emissivity on the top surface of a sample disc of known dimensions. Temperatures measured under steady-state thermal equilibrium are then used to estimate the thermal conductivity of the sample by making use of the inverse parameter estimation technique. Thermal conductivity values obtained in this way are then compared to the material data sheets and values found in literature. The reported work has been developed within the Research and Development framework of the SPES (Selective Production of Exotic Species) project at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro).

  20. Mid-infrared conductivity from mid-gap states associated with charge stripes

    Science.gov (United States)

    Homes, C. C.; Tranquada, J. M.; Li, Q.; Moodenbaugh, A. R.; Buttrey, D. J.

    2003-05-01

    The optical conductivity of La2-xSrxNiO4 has been interpreted in various ways, but so far the proposed interpretations have neglected the fact that the holes doped into the NiO2 planes order in diagonal stripes, as established by neutron and x-ray scattering. Here we present a study of optical conductivity in La2NiO4+δ with δ=2/15, a material in which the charge stripes order three dimensionally. We show that the conductivity can be decomposed into two components, a mid-infrared peak that we attribute to transitions from the filled valence band into empty mid-gap states associated with the stripes, and a Drude peak that appears at higher temperatures as carriers are thermally excited into the mid-gap states. The shift of the mid-IR peak to lower energy with increasing temperature is explained in terms of the Franck-Condon effect. The relevance of these results to understanding the optical conductivity in the cuprates is discussed.

  1. Intrinsic conduction through topological surface states of insulating Bi2Te3 epitaxial thin films.

    Science.gov (United States)

    Hoefer, Katharina; Becker, Christoph; Rata, Diana; Swanson, Jesse; Thalmeier, Peter; Tjeng, L H

    2014-10-21

    Topological insulators represent a novel state of matter with surface charge carriers having a massless Dirac dispersion and locked helical spin polarization. Many exciting experiments have been proposed by theory, yet their execution has been hampered by the extrinsic conductivity associated with the unavoidable presence of defects in Bi2Te3 and Bi2Se3 bulk single crystals, as well as impurities on their surfaces. Here we present the preparation of Bi2Te3 thin films that are insulating in the bulk and the four-point probe measurement of the conductivity of the Dirac states on surfaces that are intrinsically clean. The total amount of charge carriers in the experiment is of the order of 10(12) cm(-2) only, and mobilities up to 4,600 cm(2)/Vs have been observed. These values are achieved by carrying out the preparation, structural characterization, angle-resolved and X-ray photoemission analysis, and temperature-dependent four-point probe conductivity measurement all in situ under ultra-high-vacuum conditions. This experimental approach opens the way to prepare devices that can exploit the intrinsic topological properties of the Dirac surface states.

  2. 78 FR 44624 - Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire); Activities...

    Science.gov (United States)

    2013-07-24

    ... AFFAIRS [OMB Control No. 2900-NEW (Conduct the Point-of-Care Research Questionnaire)] Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire); Activities Under OMB Review AGENCY: Veterans...) 395-7316. Please refer to ``OMB Control No. 2900-NEW (Conduct the Point of Care Research...

  3. 78 FR 9108 - Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire) Activity...

    Science.gov (United States)

    2013-02-07

    ... AFFAIRS Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire) Activity... refer to ``OMB Control No. 2900-NEW (Conduct the Point-of-Care Research Questionnaire)'' in any... Questionnaire, VA Form 10-0557. OMB Control Number: 2900-NEW (Conduct the Point-of-Care Research...

  4. Interpretation of anomalous normal state optical conductivity of K3C60 fullerides

    Indian Academy of Sciences (India)

    K K Choudhary

    2013-02-01

    The observed frequency dependent optical response of alkali–metal-doped fulleride superconductors (c ≈ 19 K) has been theoretically analysed. The calculations of the optical conductivity, (), have been made within the two-component schemes: one is the coherent Drude carriers (electrons) responsible for superconductivity and the other is incoherent motion of carriers from one atom to other atom of C60 molecule to a pairing between Drude carriers. The approach accounts for the anomalies reported (frequency dependence of optical conductivity) in the optical measurements for the normal state. The model has only one free parameter, the relaxation rate. The frequency dependent relaxation rates are expressed in terms of memory functions. The coherent Drude carriers form a sharp peak at zero frequency and a long tail at higher frequencies, i.e. in the infrared region. However, the hopping of carriers from one atom to the other (incoherent motion of doped electrons) yields a peak value in the optical conductivity centred at mid-infrared region. It is found that both the Drude and hopping carriers will contribute to the optical process of conduction in the K3C60 and shows similar results on optical conductivity in the mid-infrared as well as infrared frequency regions as those revealed from experiments.

  5. Superior Electrical Conductivity in Hydrogenated Layered Ternary Chalcogenide Nanosheets for Flexible All-Solid-State Supercapacitors.

    Science.gov (United States)

    Hu, Xin; Shao, Wei; Hang, Xudong; Zhang, Xiaodong; Zhu, Wenguang; Xie, Yi

    2016-05-04

    As the properties of ultrathin two-dimensional (2D) crystals are strongly related to their electronic structures, more and more attempts were carried out to tune their electronic structures to meet the high standards for the construction of next-generation smart electronics. Herein, for the first time, we show that the conductive nature of layered ternary chalcogenide with formula of Cu2 WS4 can be switched from semiconducting to metallic by hydrogen incorporation, accompanied by a high increase in electrical conductivity. In detail, the room-temperature electrical conductivity of hydrogenated-Cu2 WS4 nanosheet film was almost 10(10) times higher than that of pristine bulk sample with a value of about 2.9×10(4)  S m(-1) , which is among the best values for conductive 2D nanosheets. In addition, the metallicity in the hydrogenated-Cu2 WS4 is robust and can be retained under high-temperature treatment. The fabricated all-solid-state flexible supercapacitor based on the hydrogenated-Cu2 WS4 nanosheet film shows promising electrochemical performances with capacitance of 583.3 F cm(-3) at a current density of 0.31 A cm(-3) . This work not only offers a prototype material for the study of electronic structure regulation in 2D crystals, but also paves the way in searching for highly conductive electrodes.

  6. 42 CFR 51.31 - Conduct of protection and advocacy activities.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Conduct of protection and advocacy activities. 51... REQUIREMENTS APPLICABLE TO THE PROTECTION AND ADVOCACY FOR INDIVIDUALS WITH MENTAL ILLNESS PROGRAM Protection and Advocacy Services § 51.31 Conduct of protection and advocacy activities. (a) Consistent with...

  7. 30 CFR 285.1010 - How long may I conduct activities under an Alternate Use RUE?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How long may I conduct activities under an Alternate Use RUE? 285.1010 Section 285.1010 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF... Alternate Use Rue Administration § 285.1010 How long may I conduct activities under an Alternate Use RUE?...

  8. Large apparent electric size of solid-state nanopores due to spatially extended surface conduction.

    Science.gov (United States)

    Lee, Choongyeop; Joly, Laurent; Siria, Alessandro; Biance, Anne-Laure; Fulcrand, Rémy; Bocquet, Lydéric

    2012-08-08

    Ion transport through nanopores drilled in thin membranes is central to numerous applications, including biosensing and ion selective membranes. This paper reports experiments, numerical calculations, and theoretical predictions demonstrating an unexpectedly large ionic conduction in solid-state nanopores, taking its origin in anomalous entrance effects. In contrast to naive expectations based on analogies with electric circuits, the surface conductance inside the nanopore is shown to perturb the three-dimensional electric current streamlines far outside the nanopore in order to meet charge conservation at the pore entrance. This unexpected contribution to the ionic conductance can be interpreted in terms of an apparent electric size of the solid-state nanopore, which is much larger than its geometric counterpart whenever the number of charges carried by the nanopore surface exceeds its bulk counterpart. This apparent electric size, which can reach hundreds of nanometers, can have a major impact on the electrical detection of translocation events through nanopores, as well as for ionic transport in biological nanopores.

  9. Organic proton-conducting molecules as solid-state separator materials for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Garcia, Lucia; Kaltbeitzel, Anke; Enkelmann, Volker; Gutmann, Jochen S.; Klapper, Markus; Muellen, Klaus [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)

    2011-06-21

    Organic proton-conducting molecules are presented as alternative materials to state-of-the-art polymers used as electrolytes in proton-exchanging membrane (PEM) fuel cells. Instead of influencing proton conductivity via the mobility offered by polymeric materials, the goal is to create organic molecules that control the proton-transport mechanism through supramolecular order. Therefore, a series of phosphonic acid-containing molecules possessing a carbon-rich hydrophobic core and a hydrophilic periphery was synthesized and characterized. Proton conductivity measurements as well as water uptake and crystallinity studies (powder and single-crystal X-ray analysis) were performed under various conditions. These experiments reveal that proton mobility is closely connected to crystallinity and strongly dependent on the supramolecular ordering of the compound. This study provides insights into the proton-conducting properties of this novel class of materials and the mechanisms responsible for proton transport. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Experimental investigation of the reliability issue of RRAM based on high resistance state conduction.

    Science.gov (United States)

    Zhang, Lijie; Hsu, Yen-Ya; Chen, Frederick T; Lee, Heng-Yuan; Chen, Yu-Sheng; Chen, Wei-Su; Gu, Pei-Yi; Liu, Wen-Hsing; Wang, Shun-Min; Tsai, Chen-Han; Huang, Ru; Tsai, Ming-Jinn

    2011-06-24

    In this paper, reliability issues of robust HfO(x)-based RRAM are experimentally investigated in terms of cycling ageing, temperature impact and voltage acceleration. All reliability issues can be estimated by the conduction of the high resistance state (HRS). The conduction current of the HRS exponentially increases as the square root of the applied voltage, which is well explained by 'quasi-Poole-Frenkel-type' trap assistant tunneling. Further experiments on HRS conduction at different temperatures show that the depth of the potential well of the trap in HfO(x) film is about 0.31 eV. The degradation induced by the cycling ageing is possibly ascribed to the increase of the amount of oxygen ions in the TiO(x) layer of the TiN/TiO(x)/HfO(x)/TiN device. The retention times with various stress voltages at different temperatures also exhibit an exponential relationship to the square root of the applied voltage, indicating that stress current plays a dominant role for the degradation of the HRS. An oxygen-release model is proposed to explain the relationship of retention time to HRS conduction current.

  11. Equivalent conductivity and its activation energy of NaF-AlF3 melts

    Institute of Scientific and Technical Information of China (English)

    HU Xian-wei; WANG Zhao-wen; GAO Bing-liang; SHI Zhong-ning; KAN Hong-min; LUO Xu-dong; TAO Wen-ju

    2009-01-01

    Electrical conductivity of NaF-AlF3 melts was measured by continuously varying cell constant(CVCC) technique. Relationships between equivalent conductivity at 990-1 030 ℃ and temperature and composition, and relationship between equivalent conductivity activation energy and composition of the melts were then studied on the basis of two-step decomposition mechanism of AlF63-. According to the changes of molar fractions of different anions in NaF-AlF3 melts, courses of dependence of equivalent conductivity and its activation energy on composition were analyzed. The results show that the influence of temperature on equivalent conductivity of the melts is small in the researched temperature range, and equivalent conductivity increases with increasing the molar fraction of AlF3; there is a minimum point in the activation energy-composition curve when molar fraction of AlF3 is 0.29.

  12. A Framework for Conducting Deceased Donor Research in the United States.

    Science.gov (United States)

    Glazier, Alexandra K; Heffernan, Kate Gallin; Rodrigue, James R

    2015-11-01

    There are a number of regulatory barriers both perceived and real that have hampered widespread clinical research in the field of donation and transplantation. This article sets forth a framework clarifying the existing legal requirements and their application to the conduct of research on deceased donors and donor organs within the United States. Recommendations are focused on resolving some of the ambiguity surrounding deceased donor authorization for research, Health Insurance Portability and Accountability Act requirements and the role of institutional review board oversight. The successful conduct of clinical research in the field of donation and transplantation requires an understanding of these regulatory nuances as well as identification of important ethical principles to consider. Facilitation of these concepts will ultimately provide support for innovative research designed to increase the availability of organs for transplantation. Further work identifying the optimal infrastructure for overview of clinical research in the field should be given priority.

  13. Quasiclassical calculation of the quasiparticle thermal conductivity in a mixed state

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Hiroto [Department of Physics, Okayama University, Okayama 700-8530 (Japan)]. E-mail: adachi@mp.okayama-u.ac.jp; Miranovic, Predrag [Department of Physics, University of Montenegro, Podgorica 81000 (Serbia); Ichioka, Masanori [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Machida, Kazushige [Department of Physics, Okayama University, Okayama 700-8530 (Japan)

    2007-03-15

    We report the result of calculation of the quasiparticle thermal conductivity {kappa}{sub xx}({nabla}T orthogonal B) in the vortex state of a two-dimensional superconductor. We compute {kappa}{sub xx} for both s-wave and d-wave superconductors, taking account of the spatial dependence of normal Green's function g, which is neglected in the previous studies using the Brandt-Pesch-Tewordt (BPT) method. Our results indicate that {kappa}{sub xx} based on the BPT method is slightly underestimated due to its incoherent spatial averaging procedure.

  14. New analytical solution for solving steady-state heat conduction problems with singularities

    Directory of Open Access Journals (Sweden)

    Laraqi Najib

    2013-01-01

    Full Text Available A problem of steady-state heat conduction which presents singularities is solved in this paper by using the conformal mapping method. The principle of this method is based on the Schwarz-Christoffel transformation. The considered problem is a semi-infinite medium with two different isothermal surfaces separated by an adiabatic annular disc. We show that the thermal resistance can be determined without solving the governing equations. We determine a simple and exact expression that provides the thermal resistance as a function of the ratio of annular disc radii.

  15. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR): CLOSED AND OPEN STATE CHANNEL MODELS.

    Science.gov (United States)

    Corradi, Valentina; Vergani, Paola; Tieleman, D Peter

    2015-09-18

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-binding cassette (ABC) transporter superfamily. CFTR controls the flow of anions through the apical membrane of epithelia. Dysfunctional CFTR causes the common lethal genetic disease cystic fibrosis. Transitions between open and closed states of CFTR are regulated by ATP binding and hydrolysis on the cytosolic nucleotide binding domains, which are coupled with the transmembrane (TM) domains forming the pathway for anion permeation. Lack of structural data hampers a global understanding of CFTR and thus the development of "rational" approaches directly targeting defective CFTR. In this work, we explored possible conformational states of the CFTR gating cycle by means of homology modeling. As templates, we used structures of homologous ABC transporters, namely TM(287-288), ABC-B10, McjD, and Sav1866. In the light of published experimental results, structural analysis of the transmembrane cavity suggests that the TM(287-288)-based CFTR model could correspond to a commonly occupied closed state, whereas the McjD-based model could represent an open state. The models capture the important role played by Phe-337 as a filter/gating residue and provide structural information on the conformational transition from closed to open channel.

  16. Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels.

    Directory of Open Access Journals (Sweden)

    Qijing Chen

    Full Text Available Large conductance Ca2+-activated potassium channels (BK are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α and BK (α+β1 currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1. Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms.

  17. Data inconsistencies from states with unconventional oil and gas activity.

    Science.gov (United States)

    Malone, Samantha; Kelso, Matthew; Auch, Ted; Edelstein, Karen; Ferrar, Kyle; Jalbert, Kirk

    2015-01-01

    The quality and availability of unconventional oil and gas (O&G) data in the United States have never been compared methodically state-to-state. By conducting such an assessment, this study seeks to better understand private and publicly sourced data variability and to identify data availability gaps. We developed an exploratory data-grading tool - Data Accessibility and Usability Index (DAUI) - to guide the review of O&G data quality. Between July and October 2013, we requested, collected, and assessed 5 categories of unconventional O&G data (wells drilled, violations, production, waste, and Class II disposal wells) from 10 states with active drilling activity. We based our assessment on eight data quality parameters (accessibility, usability, point location, completeness, metadata, agency responsiveness, accuracy, and cost). Using the DAUI, two authors graded the 10 states and then averaged their scores. The average score received across all states, data categories, and parameters was 67.1 out of 100, largely insufficient for proper data transparency. By state, Pennsylvania received the highest average ( = 93.5) and ranked first in all but one data category. The lowest scoring state was Texas ( = 44) largely due to its policy of charging for certain data. This article discusses the various reasons for scores received, as well as methodological limitations of the assessment metrics. We argue that the significant variability of unconventional O&G data-and its availability to the public-is a barrier to regulatory and industry transparency. The lack of transparency also impacts public education and broader participation in industry governance. This study supports the need to develop a set of data best management practices (BMPs) for state regulatory agencies and the O&G industry, and suggests potential BMPs for this purpose.

  18. Terahertz conductivity of topological surface states in Bi₁.₅Sb₀.₅Te₁.₈Se₁.₂.

    Science.gov (United States)

    Tang, Chi Sin; Xia, Bin; Zou, Xingquan; Chen, Shi; Ou, Hong-Wei; Wang, Lan; Rusydi, A; Zhu, Jian-Xin; Chia, Elbert E M

    2013-12-17

    Topological insulators are electronic materials with an insulating bulk and conducting surface. However, due to free carriers in the bulk, the properties of the metallic surface are difficult to detect and characterize in most topological insulator materials. Recently, a new topological insulator Bi₁.₅Sb₀.₅Te₁.₇Se₁.₃ (BSTS) was found, showing high bulk resistivities of 1-10 Ω.cm and greater contrast between the bulk and surface resistivities compared to other Bi-based topological insulators. Using Terahertz Time-Domain Spectroscopy (THz-TDS), we present complex conductivity of BSTS single crystals, disentangling the surface and bulk contributions. We find that the Drude spectral weight is 1-2 orders of magnitude smaller than in other Bi-based topological insulators, and similar to that of Bi₂Se₃ thin films, suggesting a significant contribution of the topological surface states to the conductivity of the BSTS sample. Moreover, an impurity band is present about 30 meV below the Fermi level, and the surface and bulk carrier densities agree with those obtained from transport data. Furthermore, from the surface Drude contribution, we obtain a ~98% transmission through one surface layer--this is consistent with the transmission through single-layer or bilayer graphene, which shares a common Dirac-cone feature in the band structure.

  19. Can molecular projected density of states (PDOS be systematically used in electronic conductance analysis?

    Directory of Open Access Journals (Sweden)

    Tonatiuh Rangel

    2015-06-01

    Full Text Available Using benzenediamine and benzenedithiol molecular junctions as benchmarks, we investigate the widespread analysis of the quantum transport conductance in terms of the projected density of states (PDOS onto molecular orbitals (MOs. We first consider two different methods for identifying the relevant MOs: (1 diagonalization of the Hamiltonian of the isolated molecule and (2 diagonalization of a submatrix of the junction Hamiltonian constructed by considering only basis elements localized on the molecule. We find that these two methods can lead to substantially different MOs and hence PDOS. Furthermore, within Method 1, the PDOS can differ depending on the isolated molecule chosen to represent the molecular junction (e.g., with or without dangling bonds; within Method 2, the PDOS depends on the chosen basis set. We show that these differences can be critical when the PDOS is used to provide a physical interpretation of the conductance (especially when its value is small, as it happens typically at zero bias. In this work, we propose a new approach in an attempt to reconcile the two traditional methods. Although some improvements were achieved, the main problems remain unsolved. Our results raise more general questions and doubts on a PDOS-based analysis of the conductance.

  20. A general approach toward enhancement of pseudocapacitive performance of conducting polymers by redox-active electrolytes

    KAUST Repository

    Chen, Wei

    2014-12-01

    A general approach is demonstrated where the pseudocapacitive performance of different conducting polymers is enhanced in redox-active electrolytes. The concept is demonstrated using several electroactive conducting polymers, including polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene). As compared to conventional electrolytes, the redox-active electrolytes, prepared by simply adding a redox mediator to the conventional electrolyte, can significantly improve the energy storage capacity of pseudocapacitors with different conducting polymers. The results show that the specific capacitance of conducting polymer based pseudocapacitors can be increased by a factor of two by utilization of the redox-active electrolytes. In fact, this approach gives some of the highest reported specific capacitance values for electroactive conducting polymers. Moreover, our findings present a general and effective approach for the enhancement of energy storage performance of pseudocapacitors using a variety of polymeric electrode materials. © 2014 Elsevier B.V. All rights reserved.

  1. Flexible all solid state supercapacitor with high energy density employing black titania nanoparticles as a conductive agent

    Science.gov (United States)

    Zhi, Jian; Yang, Chongyin; Lin, Tianquan; Cui, Houlei; Wang, Zhou; Zhang, Hui; Huang, Fuqiang

    2016-02-01

    Increasing the electrical conductivity of pseudocapacitive materials without changing their morphology is an ideal structural solution to realize both high electrochemical performance and superior flexibility for an all solid state supercapacitor (ASSSC). Herein, we fabricate a flexible ASSSC device employing black titania (TiO2-x:N) decorated two-dimensional (2D) NiO nanosheets as the positive electrode and mesoporous graphene as the negative electrode. In this unique design, NiO nanosheets are used as pseudocapacitive materials and TiO2-x:N nanoparticles serve as the conductive agent. Owing to the excellent electrical conductivity of TiO2-x:N and well defined ``particle on sheet'' planar structure of NiO/TiO2-x:N composites, the 2D morphology of the decorated NiO nanosheets is completely retained, which efficiently reinforces the pseudocapacitive activity and flexibility of the whole all solid state device. The maximum specific capacitance of fabricated the NiO/TiO2-x:N//mesoporous graphene supercapacitor can reach 133 F g-1, which is 2 and 4 times larger than the values of the NiO based ASSSC employing graphene and carbon black as the conductive agent, respectively. In addition, the optimized ASSSC displays intriguing performances with an energy density of 47 W h kg-1 in a voltage region of 0-1.6 V, which is, to the best of our knowledge, the highest value for flexible ASSSC devices. The impressive results presented here may pave the way for promising applications of black titania in high energy density flexible storage systems.Increasing the electrical conductivity of pseudocapacitive materials without changing their morphology is an ideal structural solution to realize both high electrochemical performance and superior flexibility for an all solid state supercapacitor (ASSSC). Herein, we fabricate a flexible ASSSC device employing black titania (TiO2-x:N) decorated two-dimensional (2D) NiO nanosheets as the positive electrode and mesoporous graphene as the

  2. 30 CFR 280.10 - What must I do before I may conduct prospecting activities?

    Science.gov (United States)

    2010-07-01

    ... OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR ON THE OUTER CONTINENTAL SHELF How To... stratigraphic tests, for hard minerals. If you conduct both G&G prospecting activities, you must have a separate... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I do before I may conduct...

  3. Sociological Understandings of Conduct for a Noncanonical Activity Theory: Exploring Intersections and Complementarities

    Science.gov (United States)

    Sawchuk, Peter H.; Stetsenko, Anna

    2008-01-01

    Following a discussion of activity theory as an approach to human development originally rooted in transformational change, we review the historical context and diverse conceptualizations of social conduct from the field of sociology. The discussion of social conduct is broken into theories of social action, theories of enactment, and contemporary…

  4. Design of Thermal Conductivity Apparatus Base on Transient-state Radial Cylinder Method

    Directory of Open Access Journals (Sweden)

    Bambang Dwi Argo

    2013-01-01

    Full Text Available Thermal properties i.e. thermal conductivity (k of agricultural products provide critical information and data for the design and manufacture of equipment and machines for their processing. Literature generally abounds in information on wide and common agricultural products but lack on some locally grown products. The aim of the present study was to design and construct the thermal conductivity apparatus embedded with controlled temperature system and equipped with record system supported with personal computer as data processor. The apparatus designed based on transient-state radial cylinder method, consist of three main parts i.e. measurement chamber, controls panel and data acquisition processor. Measurement chamber was cylinder equipped by radially sixteen node of thermocouple with controlled temperature heater on center cylinder axis. It was placed in temperature controlled box generated by air flow system to eliminate the effect of surrounding temperature outside chamber. Controls panel functioned as link bridge and control unit that connect the measurement chamber to data acquisition processor. It consists of some electronic circuit e.g. analog to digital converter (ADC to control and acquire data from some thermocouple and sensors. Personal computer as data acquisition processor embedded with software developed with Borland Delphi. Developed software featured with calibrating, recording, calculating mode and displaying all obtained data graphically. Testing procedure was conducted with empty and filled chamber condition to adjust and calibrate data captured by thermocouples and sensors and displayed on personal computer, compared with actual condition. After some adjustment and calibration, all system was well functioned. The outcomes were in good agreements with thermal conductivity (k of agricultural products reported in the literatures.Keywords—

  5. Effects of active conductance distribution over dendrites on the synaptic integration in an identified nonspiking interneuron.

    Directory of Open Access Journals (Sweden)

    Akira Takashima

    Full Text Available The synaptic integration in individual central neuron is critically affected by how active conductances are distributed over dendrites. It has been well known that the dendrites of central neurons are richly endowed with voltage- and ligand-regulated ion conductances. Nonspiking interneurons (NSIs, almost exclusively characteristic to arthropod central nervous systems, do not generate action potentials and hence lack voltage-regulated sodium channels, yet having a variety of voltage-regulated potassium conductances on their dendritic membrane including the one similar to the delayed-rectifier type potassium conductance. It remains unknown, however, how the active conductances are distributed over dendrites and how the synaptic integration is affected by those conductances in NSIs and other invertebrate neurons where the cell body is not included in the signal pathway from input synapses to output sites. In the present study, we quantitatively investigated the functional significance of active conductance distribution pattern in the spatio-temporal spread of synaptic potentials over dendrites of an identified NSI in the crayfish central nervous system by computer simulation. We systematically changed the distribution pattern of active conductances in the neuron's multicompartment model and examined how the synaptic potential waveform was affected by each distribution pattern. It was revealed that specific patterns of nonuniform distribution of potassium conductances were consistent, while other patterns were not, with the waveform of compound synaptic potentials recorded physiologically in the major input-output pathway of the cell, suggesting that the possibility of nonuniform distribution of potassium conductances over the dendrite cannot be excluded as well as the possibility of uniform distribution. Local synaptic circuits involving input and output synapses on the same branch or on the same side were found to be potentially affected under

  6. A conducting polymer nucleation scheme for efficient solid-state supercapacitors on paper

    KAUST Repository

    Kurra, Narendra

    2014-08-19

    In this study, a thin nucleation layer is used to tune the morphology of conducting polymer electrodes and to optimize the performance of paper based solid-state supercapacitors. It is found that using an acid-treated poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) nucleation layer, prior to poly(3,4-ethylenedioxythiophene), PEDOT, electrochemical deposition, gives 5-6 times higher areal capacitance compared to a gold metal nucleation layer. Specifically, PEDOT supercapacitors with a high volumetric capacitance of 327 F cm-3, higher than any other PEDOT based supercapacitors reported in the literature, is achieved on the PEDOT:PSS nucleation layer; for the same devices, an areal capacitance of 242 mF cm-2 and an energy density of 14.5 mW h cm-3 at a power density of 350 mW cm-3 are obtained. Furthermore, these optimized PEDOT/PEDOT:PSS/paper electrodes are employed to fabricate solid-state supercapacitors using aqueous and ion gel electrolytes, with 32 and 11 mF cm-2 cell capacitance, respectively. The solid-state PEDOT device showed an energy density of 1.5 mW h cm-3 (normalised to the volume of the whole cell, including both the electrodes and the electrolyte), which is higher than the best reported ppy/paper (E = 1 mW h cm-3) and PAni/pencil/paper (E = 0.32 mW h cm-3) solid-state devices. The cycling performance showed that capacitance retention up to 80% is achieved after 10000 cycles. This journal is

  7. Anisotropy of the nitrogen conduction states in the group III nitrides studied by polarized x-ray absorption

    Energy Technology Data Exchange (ETDEWEB)

    Lawniczak-Jablonska, K. [Lawrence Berkeley National Lab., CA (United States)]|[Institute of Physics, Warsaw (Poland); Liliental-Weber, Z.; Gullikson, E.M. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Group III nitrides (AlN, GaN, and InN) consist of the semiconductors which appear recently as a basic materials for optoelectronic devices active in the visible/ultraviolet spectrum as well as high-temperature and high-power microelectronic devices. However, understanding of the basic physical properties leading to application is still not satisfactory. One of the reasons consists in unsufficient knowledge of the band structure of the considered semiconductors. Several theoretical studies of III-nitrides band structure have been published but relatively few experimental studies have been carried out, particularly with respect to their conduction band structure. This motivated the authors to examine the conduction band structure projected onto p-states of the nitrogen atoms for AlN, GaN and InN. An additional advantage of their studies is the availability of the studied nitrides in two structures, hexagonal (wurtzite) and cubic (zincblende). This offers an opportunity to gain information about the role of the anisotropy of electronic band states in determining various physical properties.

  8. Specific heat and thermal conductivity in the mixed state of MgB2.

    Science.gov (United States)

    Tewordt, L; Fay, D

    2002-09-23

    The specific heat C and the electronic and phononic thermal conductivities kappa(e) and kappa(ph) are calculated in the mixed state for magnetic fields H near H(c2), including the effects of supercurrent flow and Andreev scattering. The resulting function C(H) is nearly linear while kappa(e)(H) exhibits an upward curvature near H(c2). The slopes decrease with impurity scattering which improves the agreement with the data on MgB2. The ratio of phonon relaxation times tau(n)/tau(s)=g(omega(0),H) for phonon energy omega(0) is smeared out around omega(0)=2Delta and tends to one for increasing H. This leads to a rapid reduction of kappa(ph)(H) in MgB2 for relatively small fields due to the rapid suppression of the smaller energy gap.

  9. New Activated Carbon with High Thermal Conductivity and Its Microwave Regeneration Performance

    Institute of Scientific and Technical Information of China (English)

    GU Xuexian; SU Zhanjun; XI Hongxia

    2016-01-01

    Using a walnut shell as a carbon source and ZnCl2 as an activating agent, we resolved the temperature gradient problems of activated carbon in the microwave desorption process. An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermal conductivity while developing VOC adsorption-microwave regeneration technology. The experimental results show that the coefficient of thermal conductivity of SiC-AC is three times as much as those of AC and SY-6. When microwave power was 480 W in its microwave desorption , the temperature of the bed thermal desorption was 10℃ to 30℃below that of normal activated carbon prepared in our laboratory. The toluene desorption activation energy was 16.05 kJ∙mol-1, which was 15% less than the desorption activation energy of commercial activated carbon. This study testified that the process could maintain its high adsorption and regeneration desorption performances.

  10. Application of the thermoelectric phenomena to study the unsteady-state thermal conductivity

    Science.gov (United States)

    Poprawski, W.; Radojewska, E. B.

    2016-09-01

    We present an experimental set-up designed to investigate the unsteady-state thermal conductivity. A sine-shaped thermal wave is produced by a thermoelectric device and the change in temperature at two points in a metal rod is measured. The investigation is carried out for seven thermal wave frequencies. The thermal wave penetration depth and the thermal conductivity are determined by two methods: from the wave amplitude ratio and from the wave phase shift at two locations. The presented system also offers a determination of the thermal wave propagation velocity and the thermal diffusivity coefficient of the medium. The obtained measurement results are discussed. The specification of the measurement system is preceded by a theoretical and comprehensive description of the phenomena taking part in the experiment. With regard to the role of thermoelectric phenomena in contemporary science and technology the presented experiment is suitable for students in university laboratories studying metrology, electronics, space technology, energy harvesting, energo-mechanics, renewable energy science, chemical technology, bio-engineering and other similar courses.

  11. A.c. conductivity and dielectric study of LiNiPO4 synthesized by solid-state method

    Indian Academy of Sciences (India)

    M Ben Bechir; A Ben Rhaiem; K Guidara

    2014-05-01

    LiNiPO4 compound was prepared by the conventional solid-state reaction. The sample was characterized by X-ray powder diffraction, infrared, Raman analysis spectroscopy and electrical impedance spectroscopy. The compound crystallizes in the orthorhombic system, space group with = 10.0252(7) Å, = 5.8569(5) Å and = 4.6758(4) Å. Vibrational analysis was used to identify the presence of PO$^{3-}_{4}$ group in this compound. The complex impedance has been measured in the temperature and frequency ranges 654–716 K and 242 Hz–5 MHz, respectively. The ' and '' vs frequency plots are well-fitted to an equivalent circuit consisting of series of combination of grains and grain boundary elements. Dielectric data were analysed using complex electrical modulus * for the sample at various temperatures. The modulus plots are characterized by the presence of two peaks thermally activated. The frequency dependence of the conductivity is interpreted in terms of equation: _a.c.() = [g/(1 + 22) + (∞22/1 + 22) + An]. The near values of activation energies obtained from the analysis of ", conductivity data and equivalent circuit confirms that the transport is through ion hopping mechanism dominated by the motion of Li+ in the structure of the investigated material.

  12. The influence of the solid thermal conductivity on active magnetic regenerators

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Engelbrecht, Kurt

    2012-01-01

    The influence of the thermal conductivity of the regenerator solid on the performance of a flat plate active magnetic regenerator (AMR) is investigated using an established numerical AMR model. The cooling power at different (fixed) temperature spans is used as a measure of the performance...... for a range of thermal conductivities, operating frequencies, a long and short regenerator, and finally a regenerator with a low and a high number of transfer units (NTU) regenerator. In this way the performance is mapped out and the impact of the thermal conductivity of the solid is probed. Modeling shows...... that under certain operating conditions, the AMR cycle is sensitive to the solid conductivity. It is found that as the operating frequency is increased it is not only sufficient to have a high NTU regenerator but the regenerator performance will also benefit from increased thermal conductivity in the solid...

  13. 49 CFR 1103.11 - Standards of ethical conduct in courts of the United States to be observed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Standards of ethical conduct in courts of the... PRACTITIONERS Canons of Ethics The Practitioner's Duties and Responsibilities Toward the Board § 1103.11 Standards of ethical conduct in courts of the United States to be observed. These canons further the...

  14. Electrons in feldspar II: A consideration of the influence of conduction band-tail states on luminescence processes

    DEFF Research Database (Denmark)

    Poolton, H.R.J.; Ozanyan, K.B.; Wallinga, J.

    2002-01-01

    Most natural feldspars contain many charged impurities, and display a range of bond angles, distributed about the ideal. These effects can lead to complications in the structure of the conduction band, giving rise to a tail of energy states (below the high-mobility conduction band) through which ...

  15. A Ta/W mixed addenda heteropolyacid with excellent acid catalytic activity and proton-conducting property

    Science.gov (United States)

    Li, Shujun; Peng, Qingpo; Chen, Xuenian; Wang, Ruoya; Zhai, Jianxin; Hu, Weihua; Ma, Fengji; Zhang, Jie; Liu, Shuxia

    2016-11-01

    A new HPAs H20[P8W60Ta12(H2O)4(OH)8O236]·125H2O (H-1) which comprises a Ta/W mixed addenda heteropolyanion, 20 protons, and 125 crystalline water molecules has been prepared through ion-exchange method. The structure and properties of H-1 have been explored in detail. AC impedance measurements indicate that H-1 is a good solid state proton conducting material at room temperature with a conductivity value of 7.2×10-3 S cm-1 (25 °C, 30% RH). Cyclic voltammograms of H-1 indicate the electrocatalytic activity towards the reduction of nitrite. Hammett acidity constant H0 of H-1 in CH3CN is -2.91, which is the strongest among the present known HPAs. Relatively, H-1 exhibits excellent catalytic activities toward acetal reaction.

  16. Techniques for Reducing Thermal Contact Resistance in Steady-State Thermal Conductivity Measurements on Polymer Composites

    Science.gov (United States)

    Stacey, C.; Simpkin, A. J.; Jarrett, R. N.

    2016-11-01

    The National Physical Laboratory (NPL) has developed a new variation on the established guarded hot plate technique for steady-state measurements of thermal conductivity. This new guarded hot plate has been specifically designed for making measurements on specimens with a thickness that is practical for advanced industrial composite materials and applications. During the development of this new guarded hot plate, NPL carried out an experimental investigation into methods for minimising the thermal contact resistance between the test specimen and the plates of the apparatus. This experimental investigation included tests on different thermal interface materials for use in another NPL facility based on a commercial guarded heat flow meter apparatus conforming to standard ASTM E1530-11. The results show the effect of applying different quantities of the type of heat transfer compound suggested in ASTM E1530-11 (clause 10.7.3) and also the effect on thermal resistance of alternative types of thermal interface products. The optimum quantities of two silicone greases were determined, and a silicone grease filled with copper was found to offer the best combination of repeatability, small hysteresis effect and a low thermal contact resistance. However, two products based on a textured indium foil and pyrolytic graphite sheet were found to offer similar or better reductions in thermal contact resistance, but with quicker, easier application and the advantages of protecting the apparatus plates from damage and being useable with specimen materials that would otherwise absorb silicone grease.

  17. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion

    Science.gov (United States)

    Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

    2016-08-01

    Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

  18. Human Nutrition Research Conducted at State Agricultural Experiment Stations and 1890/Tuskegee Agricultural Research Programs.

    Science.gov (United States)

    Driskell, Judy A.; Myers, John R.

    1989-01-01

    Cooperative State Research Service-administered and state-appropriated State Agriculture Experiment Station funds for human nutrition research increased about two-fold from FY70-FY86, while the percentage of budget expended for this research decreased. (JOW)

  19. 5-HT1A receptors modulate small-conductance Ca2+-activated K+ channels

    DEFF Research Database (Denmark)

    Grunnet, Morten; Jespersen, Thomas; Perrier, Jean-François

    2004-01-01

    Small-conductance calcium-activated potassium channels (SK) are responsible for the medium afterhyperpolarisation (mAHP) following action potentials in neurons. Here we tested the ability of serotonin (5-HT) to modulate the activity of SK channels by coexpressing 5-HT1A receptors with different...... subtypes of SK channels (SK1, SK2, and SK3) in Xenopus laevis oocytes. SK channels were activated by intracellular injection of Cd2+. Subsequent activation of 5-HT1A receptors by 8-OH-DPAT always produced an inhibition of the SK current, showing the existence of a specific pathway between the receptor...

  20. Subharmonic gap structure of normal-state conductance and thermoelectric effect in a graphene-based nano device.

    Science.gov (United States)

    Park, K S; Park, Joonho; Yi, K S

    2008-09-01

    Using the quantum transport of chiral Dirac fermions in graphene, we investigate the normal-state conductance and thermoelectric effect of a nano device under the ballistic superconductor-graphene-superconductor (SGS) model. Because of the Josephson effect and Andreev reflections, there exists an oscillatory behavior of the normal-state conductance flowing through the successive discrete energy levels on a finite-sized graphene contacted to the superconducting leads. The normal-state conductance displays a rich structure of subharmonic gaps controlled by means of a gate voltage on the discrete energy levels near the Fermi energy. Since the Fermi energy is an essential factor in determining the nature of conduction such as n or p type, we study the thermoelectric effect over the graphene-based nano device. It is shown that the thermoelectric effect can provide information on the location of the Fermi energy with respect to the energy levels of the finite-sized graphene.

  1. 21 CFR 312.87 - Active monitoring of conduct and evaluation of clinical trials.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Active monitoring of conduct and evaluation of clinical trials. 312.87 Section 312.87 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Drugs Intended to Treat Life-threatening...

  2. Dielectric behavior, conduction and EPR active centres in BiVO4 nanoparticles

    Science.gov (United States)

    Venkatesan, Rajalingam; Velumani, Subramaniam; Tabellout, Mohamed; Errien, Nicolas; Kassiba, Abdelhadi

    2013-12-01

    Bismuth vanadate (BiVO4) nanomaterials were synthesized by mechano-chemical ball milling method and complementary investigations were devoted to their structures, nanoparticle morphologies and electronic active centres. The dielectric and conductivity behaviour were analysed systematically in wide temperature and frequency ranges to correlate such physical responses with the peculiarities of the samples. Large interfacial polarisations favoured by high specific surfaces of nanoparticles account for a drastic enhancement of the dielectric function in the quasi-static regime. Exhaustive analyses of the dielectric experiments were achieved and account for the main features of dielectric functions and their related relaxation mechanisms. The electrical conductivity is thermally activated with energies in the range 0.1-0.6 eV depending on the sample features. DC conductivity up to 10-3 S/cm was obtained in well crystallized nanoparticles. Vanadium ions reduction was revealed by EPR spectroscopy with higher concentrations of the active centres (V4+) in more agglomerated and amorphous nanopowders. The EPR spectral parameters of V4+ were determined and correlated with the local environments of reduced vanadium ions and the characteristics of their electronic configurations. An insight is also made on the role of active electronic centres (V4+) on the conduction mechanism in nanostructured BiVO4.

  3. A Context-Aware Ubiquitous Learning Approach to Conducting Scientific Inquiry Activities in a Science Park

    Science.gov (United States)

    Hwang, Gwo-Jen; Tsai, Chin-Chung; Chu, Hui-Chun; Kinshuk; Chen, Chieh-Yuan

    2012-01-01

    Fostering students' scientific inquiry competence has been recognised as being an important and challenging objective of science education. To strengthen the understanding of science theories or notations, researchers have suggested conducting some learning activities in the field via operating relevant devices. In a traditional infield scientific…

  4. Thermally activated conductance of a silicon inversion layer by electrons excited above the mobility edge

    NARCIS (Netherlands)

    Niederer, H.H.J.M.; Mattey, A.P.M.; Sparnaay, M.J.

    1981-01-01

    The thermally activated conductivity sigma of an n-type inversion layer on a (100) oriented silicon surface and its derivative d sigma /dT were measured in the temperature range 1.4K-4.2K. Above T approximately=2.5K both the temperature dependence of (T/ sigma ) (d sigma /dT) and the relation betwee

  5. 75 FR 79342 - Taking and Importing Marine Mammals; Navy Training Activities Conducted Within the Northwest...

    Science.gov (United States)

    2010-12-20

    ... Activities and Research, Development, Testing and Evaluation Conducted Within the Mariana Islands Range... (including Navy, USMC, and USAF) training and research, development, testing, and evaluation (RDT&E... Harassment, 2 individuals of 2 species by Level A Harassment annually, and 10 individual beaked whales...

  6. Hydralazine-induced vasodilation involves opening of high conductance Ca2+-activated K+ channels

    DEFF Research Database (Denmark)

    Bang, Lone; Nielsen-Kudsk, J E; Gruhn, N;

    1998-01-01

    The purpose of this study was to investigate whether high conductance Ca2+-activated K+ channels (BK(Ca)) are mediating the vasodilator action of hydralazine. In isolated porcine coronary arteries, hydralazine (1-300 microM), like the K+ channel opener levcromakalim, preferentially relaxed...

  7. Immunolocalization and expression of small-conductance calcium-activated potassium channels in human myometrium

    DEFF Research Database (Denmark)

    Rosenbaum, Sofia T; Svalø, Julie; Nielsen, Karsten;

    2012-01-01

    Small-conductance calcium-activated potassium (SK3) channels have been detected in human myometrium and we have previously shown a functional role of SK channels in human myometrium in vitro. The aims of this study were to identify the precise localization of SK3 channels and to quantify SK3 mRNA...

  8. Inhibition of small-conductance Ca2+-activated K+ channels terminates and protects against atrial fibrillation

    DEFF Research Database (Denmark)

    Diness, Jonas Goldin; Sørensen, Ulrik S; Nissen, Jakob Dahl

    2010-01-01

    Recently, evidence has emerged that small-conductance Ca(2+)-activated K(+) (SK) channels are predominantly expressed in the atria in a number of species including human. In rat, guinea pig, and rabbit ex vivo and in vivo models of atrial fibrillation (AF), we used 3 different SK channel inhibito...

  9. WNK1 Activates Large-Conductance Ca2+-Activated K+ Channels through Modulation of ERK1/2 Signaling

    OpenAIRE

    Liu, Yingli; Song, Xiang; Shi, Yanling; Shi, Zhen; Niu, Weihui; Feng, Xiuyan; Gu, Dingying; Bao, Hui-Fang; Ma, He-Ping; Eaton, Douglas C.; Zhuang, Jieqiu; Cai, Hui

    2014-01-01

    With no lysine (WNK) kinases are members of the serine/threonine kinase family. We previously showed that WNK4 inhibits renal large-conductance Ca2+-activated K+ (BK) channel activity by enhancing its degradation through a lysosomal pathway. In this study, we investigated the effect of WNK1 on BK channel activity. In HEK293 cells stably expressing the α subunit of BK (HEK-BKα cells), siRNA-mediated knockdown of WNK1 expression significantly inhibited both BKα channel activity and open probabi...

  10. Analysis Of Soil NPK Ph And Electrical Conductivity At Adham Area- Renk Upper Nile State

    Directory of Open Access Journals (Sweden)

    Abubaker Haroun Mohamed Adam

    2015-08-01

    Full Text Available ABSTRACT The objectives of this study were to investigate soil type potentiality and reaction in relation to the scattered remaining vegetation species and to quantify soil suitability for growing field crops. Adham area witnessed serious land degradation due to the rapid expansion of Rain-fed Mechanized Farming and overgrazing. Consequently the low crop yield enforced the local communities to shift to the alternative sources of income generating activities particularly those related to forest products like charcoal making firewood production logging and tree lobbing. By using Randomized Complete Block Design RCBD with emphasizes on Macro nutrients particularly the Nitrogen Phosphorous and potassium NPK in addition to soil pH and Electrical Conductivity EC. random soil samples each with three levels of depths 0 - 15 15 - 30 30 - 45 cm. were collected. All collected data were analyzed in the laboratory. The result of revealed several types of soils including the cracking and non -cracking clay sandy and red soils. The result of statistical analysis depicted variability in NPK pH and EC between the different locations and soil depths. Furthermore the result showed an association between some studied soil attributes and the spatial distribution of the vegetation species. Rational use through participatory approach is recommended for natural resources management conservation and sustainability. Moreover further study using space technology also recommended.

  11. Chemically robust platform for optical solid-state conducting polymer sensor

    Science.gov (United States)

    Holt, A. L.; Bearinger, J. P.; Carter, S. A.

    2006-10-01

    Conjugated polymers are unique materials for use in the development of chemical and biological sensors because of their widely tunable optical and electrical properties that allow them dual functionality as both the sensing element and the signal transducer. Furthermore, as optical photoluminescence based sensors, electroactive polymers are found to exhibit high sensitivity due to the ability of the analyte of interest to quench the photoluminescence of the entire polymer chain. In order to produce a more chemically robust thin film for use as a "solid-state" optical sensor, we succeeded in grafting various poly (3-alkyl-thiophene)s to optically transparent substrates such as glass, quartz, and ITO coated glass. This was accomplished by first grafting a thiophene monomer to the surface then chemically growing the films via oxidative polymerization. XPS studies indicated that each chemical step was accurately understood. The polythiophene growth, unaltered by sonication and tape peeling tests, was uniform across the substrate and could be directed by selective silanization of the substrate. Film thicknesses range from 20 to 200 nm and exhibit varying degrees of surface roughness, depending on the polymerization process. The reaction times and solvents were varied in order to optimize the desired film properties. The absorption and photoluminescence properties of the thin films compared well with literature on spun-cast polythiophene films, as did the electrical conductivities of the doped and undoped material. The photoluminescence intensities of the films are found to be unaffected by paraquat in water but are sensitive to trace amounts of ferric chloride in acetonitrile with measurable Stern Volmer constants.

  12. Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser Heat-flux Approach

    Science.gov (United States)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

    The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.

  13. 49 CFR Appendix to Subtitle A - United States Railway Association-Employee Responsibilities and Conduct

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false United States Railway Association-Employee... Subtitle A, App. Appendix to Subtitle A—United States Railway Association—Employee Responsibilities and... United States Railway Association (the Association). The standards and requirements are appropriate...

  14. Validity Evidence for the State Mindfulness Scale for Physical Activity

    Science.gov (United States)

    Cox, Anne E.; Ullrich-French, Sarah; French, Brian F.

    2016-01-01

    Being attentive to and aware of one's experiences in the present moment with qualities of acceptance and openness reflects the state of mindfulness. Positive associations exist between state mindfulness and state autonomous motivation for everyday activities. Though this suggests that state mindfulness links with adaptive motivational experiences,…

  15. Potassium conductances mediate bidirectional state-dependent modulation of action potential evoked dendritic calcium signals in dentate gyrus granule cells

    Directory of Open Access Journals (Sweden)

    János Brunner

    2014-03-01

    resulted in faster repolarization and increased AP related calcium signals relative to the control (i. e. in the absence of the extra conductance at the same membrane potential. In conclusion, our results revealed that activation of potassium currents can profoundly enhance dendritic bAP-evoked calcium signals in GC dendrites, thus providing a previously unknown state-dependent modulatory mechanism in dendritic signalization.

  16. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation.

    Science.gov (United States)

    Ehrlich, Lili E; Feig, Justin S G; Schiffres, Scott N; Malen, Jonathan A; Rabin, Yoed

    2015-01-01

    Thermal conductivity of dimethyl-sulfoxide (DMSO) solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA) cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180°C and 25°C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology.

  17. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation.

    Directory of Open Access Journals (Sweden)

    Lili E Ehrlich

    Full Text Available Thermal conductivity of dimethyl-sulfoxide (DMSO solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180°C and 25°C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology.

  18. [The active middle ear implant for the rehabilitation of sensorineural, mixed and conductive hearing losses].

    Science.gov (United States)

    Sprinzl, G M; Wolf-Magele, A; Schnabl, J; Koci, V

    2011-09-01

    Active middle ear implants, such as the Vibrant Soundbridge, are used as an important part in the rehabilitation of sensorineural, conductive hearing, or mixed hearing loss. The attachment of the Vibrant Soundbridge at the round window and the usage of the Vibroplasty couplers strongly expanded the application of the Vibrant Soundbridge.The Vibrant Soundbridge is developed for patients who have an intolerance to hearing aids and a moderate to profound sensorineural hearing loss. The VSB also provides an optimal solution for patients with failed middle ear reconstructions or patients with atresia. To capture the improvement with the VSB Implant with different hearing losses a literature analysis was conducted. The functional gain was analyzed for 107 patients with conductive hearing loss and for 214 patients with sensorineural hearing loss out of 14 studies.Patients with conductive and mixed hearing loss resulted in a functional gain from 30 to 58 dB with the VSB. Patients with a pure sensorineural hearing loss showed a functional gain of 23-30 dB. The VSB bone conduction threshold shift was analyzed for all studies conducted in the years between 2000 and 2009. In 11 of the 16 studies there was no significant (p=0.05) change found. In 5 studies, the pre- to post-surgical bone conduction threshold shift was less than 10 dB. None of these studies measured a threshold shift of more than 10 dB.The flexible attachment at either the long process of the incus with sensorineural hearing loss, with an conductive hearing loss at the round window or the use of Vibroplasty couplers at the oval window, head of the stapes or round window makes the VSB an extremely versatile instrument. If patients can't wear conventional hearing aids, had failed middle ear reconstructions or atresia the VSB presents, due to the significant hearing improvement in any type of hearing loss, an ideal solution.

  19. Active Affordance Learning in Continuous State and Action Spaces

    NARCIS (Netherlands)

    Wang, C.; Hindriks, K.V.; Babuska, R.

    2014-01-01

    Learning object affordances and manipulation skills is essential for developing cognitive service robots. We propose an active affordance learning approach in continuous state and action spaces without manual discretization of states or exploratory motor primitives. During exploration in the action

  20. Thermally activated conductivity of Si hybrid structure based on ZnPc thin film

    Science.gov (United States)

    Soylu, M.; Al-Ghamdi, Ahmed A.; Yakuphanoglu, F.

    2016-10-01

    In this study, an analysis of temperature-dependent electrical characteristics of ZnPc/p-Si structure has been presented. Conduction mechanisms that are accounted for the organic/inorganic devices are evaluated. At low forward voltage, current-voltage ( I- V) characteristics show ohmic behavior, limiting extraction of holes from p-Si over the ZnPc/p-Si heterojunction. Thermally activated conduction mechanism appears to be space-charge-limited conduction mechanism, taking into account the presence of an exponential trap distribution with total concentration of traps, N t of 5.77 × 1025 m-3. The series resistance is found to be temperature dependent. There is a critical point on the regime of series resistance at 200 K. The capacitance varies with temperature at different rates below and above room temperature, indicating a variation in the dielectric constant.

  1. Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents.

    Science.gov (United States)

    Walker, Harrison C; Lawrence, J Josh; McBain, Chris J

    2002-07-03

    Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.

  2. Mid-Infrared Conductivity from Mid-Gap States Associated with Charge Stripes

    OpenAIRE

    Homes, C. C.; Tranquada, J. M.; Li, Q; Moodenbaugh, A. R.; Buttrey, D. J.

    2002-01-01

    The optical conductivity of La(2-x)Sr(x)NiO(4) has been interpreted in various ways, but so far the proposed interpretations have neglected the fact that the holes doped into the NiO(2) planes order in diagonal stripes, as established by neutron and X-ray scattering. Here we present a study of optical conductivity in La(2)NiO(4+d) with d=2/15, a material in which the charge stripes order three-dimensionally. We show that the conductivity can be decomposed into two components, a mid-infrared p...

  3. Derivation of nonlinear optical conductivity by using a reduction identity and a state-dependent projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Nam Lyong [Faculty of Nanoscience and Nanotechnology, Pusan National University, Miryang 627-706 (Korea, Republic of); Choi, Sang Don [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)], E-mail: sdchoi@knu.ac.kr

    2010-04-23

    A new nonlinear optical conductivity formula for a system of electrons interacting with phonons was derived using a reduction identity and a state-dependent projection technique introduced by the authors. The results include a general formula for the nonlinear optical conductivity of the general rank and the linear, first-order nonlinear and second-order nonlinear conductivity are calculated in terms of the linewidth. The linewidth term includes the electron and phonon distribution functions properly. Therefore, it is possible to explain the phonon emission and absorption in all electron transition processes in an organized manner.

  4. Activation of big conductance Ca(2+)-activated K (+) channels (BK) protects the heart against ischemia-reperfusion injury

    DEFF Research Database (Denmark)

    Bentzen, Bo Hjorth; Osadchii, Oleg; Jespersen, Thomas;

    2009-01-01

    complexes, while producing no effect on cardiac K(ATP) channels. The cardioprotective effects of NS11021-induced BK channel activation were studied in isolated, perfused rat hearts subjected to 35 min of global ischemia followed by 120 min of reperfusion. 3 microM NS11021 applied prior to ischemia...... (3 microM) antagonized the protective effect. These findings suggest that tissue damage induced by ischemia and reperfusion can be reduced by activation of cardiac BK channels.......Activation of the large-conductance Ca(2+)-activated K(+) channel (BK) in the cardiac inner mitochondrial membrane has been suggested to protect the heart against ischemic injury. However, these findings are limited by the low selectivity profile and potency of the BK channel activator (NS1619...

  5. Valence and Conduction Band Densities of States of Metal Halide Perovskites: A Combined Experimental–Theoretical Study

    OpenAIRE

    Endres, James; Egger, David A.; Kulbak, Michael; Kerner, Ross A.; Zhao, Lianfeng; Silver, Scott H.; Hodes, Gary; Rand, Barry P.; Cahen, David; Kronik, Leeor; Kahn, Antoine

    2016-01-01

    We report valence and conduction band densities of states measured via ultraviolet and inverse photoemission spectroscopies on three metal halide perovskites, specifically methylammonium lead iodide and bromide and cesium lead bromide (MAPbI3, MAPbBr3, CsPbBr3), grown at two different institutions on different substrates. These are compared with theoretical densities of states (DOS) calculated via density functional theory. The qualitative agreement achieved between experiment and theory lead...

  6. Conductivity and Activation Energy in Polymers Synthesized by Plasmas of Thiophene

    OpenAIRE

    Ma. Guadalupe Olayo; Cruz, Guillermo J.; Salvador López; Juan Morales; Roberto Olayo

    2010-01-01

    The electric conductivity, activation energy and morphology of polythiophene synthesized by radiofrequency resistive plasmas are studied in this work. The continuous collisions of particles in the plasma induce the polymerization of thiophene but also break some of the monomer molecules producing complex polymers with thiophene rings and aliphatic hydrocarbon segments. These multidirectional chemical reactions are more marked at longer reaction times in which the morphology of the polymers ev...

  7. UP states protect ongoing cortical activity from thalamic inputs.

    Directory of Open Access Journals (Sweden)

    Brendon O Watson

    Full Text Available Cortical neurons in vitro and in vivo fluctuate spontaneously between two stable membrane potentials: a depolarized UP state and a hyperpolarized DOWN state. UP states temporally correspond with multineuronal firing sequences which may be important for information processing. To examine how thalamic inputs interact with ongoing cortical UP state activity, we used calcium imaging and targeted whole-cell recordings of activated neurons in thalamocortical slices of mouse somatosensory cortex. Whereas thalamic stimulation during DOWN states generated multineuronal, synchronized UP states, identical stimulation during UP states had no effect on the subthreshold membrane dynamics of the vast majority of cells or on ongoing multineuronal temporal patterns. Both thalamocortical and corticocortical PSPs were significantly reduced and neuronal input resistance was significantly decreased during cortical UP states -- mechanistically consistent with UP state insensitivity. Our results demonstrate that cortical dynamics during UP states are insensitive to thalamic inputs.

  8. CNTF-Treated Astrocyte Conditioned Medium Enhances Large-Conductance Calcium-Activated Potassium Channel Activity in Rat Cortical Neurons.

    Science.gov (United States)

    Sun, Meiqun; Liu, Hongli; Xu, Huanbai; Wang, Hongtao; Wang, Xiaojing

    2016-08-01

    Seizure activity is linked to astrocyte activation as well as dysfunctional cortical neuron excitability produced from changes in calcium-activated potassium (KCa) channel function. Ciliary neurotrophic factor-treated astrocyte conditioned medium (CNTF-ACM) can be used to investigate the peripheral effects of activated astrocytes upon cortical neurons. However, CNTF-ACM's effect upon KCa channel activity in cultured cortical neurons has not yet been investigated. Whole-cell patch clamp recordings were performed in rat cortical neurons to evaluate CNTF-ACM's effects upon charybdotoxin-sensitive large-conductance KCa (BK) channel currents and apamin-sensitive small-conductance KCa (SK) channel current. Biotinylation and RT-PCR were applied to assess CNTF-ACM's effects upon the protein and mRNA expression, respectively, of the SK channel subunits SK2 and SK3 and the BK channel subunits BKα1 and BKβ3. An anti-fibroblast growth factor-2 (FGF-2) monoclonal neutralizing antibody was used to assess the effects of the FGF-2 component of CNTF-ACM. CNTF-ACM significantly increased KCa channel current density, which was predominantly attributable to gains in BK channel activity (p ACM produced a significant increase in BKα1 and BKβ3 expression (p  0.05). Blocking FGF-2 produced significant reductions in KCa channel current density (p > 0.05) as well as BKα1 and BKβ3 expression in CNTF-ACM-treated neurons (p > 0.05). CNTF-ACM significantly enhances BK channel activity in rat cortical neurons and that FGF-2 is partially responsible for these effects. CNTF-induced astrocyte activation results in secretion of neuroactive factors which may affect neuronal excitability and resultant seizure activity in mammalian cortical neurons.

  9. Intrinsic conductances actively shape excitatory and inhibitory postsynaptic responses in olfactory bulb external tufted cells.

    Science.gov (United States)

    Liu, Shaolin; Shipley, Michael T

    2008-10-08

    The initial synapse in the olfactory system is from olfactory nerve (ON) terminals to postsynaptic targets in olfactory bulb glomeruli. Recent studies have disclosed multiple presynaptic factors that regulate this important linkage, but less is known about the contribution of postsynaptic intrinsic conductances to integration at these synapses. The present study demonstrates voltage-dependent amplification of EPSPs in external tufted (ET) cells in response to monosynaptic (ON) inputs. This amplification is mainly exerted by persistent Na(+) conductance. Larger EPSPs, which bring the membrane potential to a relatively depolarized level, are further boosted by the low-voltage-activated Ca(2+) conductance. In contrast, the hyperpolarization-activated nonselective cation conductance (I(h)) attenuates EPSPs mainly by reducing EPSP duration; this also reduces temporal summation of multiple EPSPs. Regulation of EPSPs by these subthreshold, voltage-dependent conductances can enhance both the signal-to-noise ratio and the temporal summation of multiple synaptic inputs and thus help ET cells differentiate high- and low-frequency synaptic inputs. I(h) can also transform inhibitory inputs to postsynaptic excitation. When the ET cell membrane potential is relatively depolarized, as during a burst of action potentials, IPSPs produce classic inhibition. However, near resting membrane potentials where I(h) is engaged, IPSPs produce rebound bursts of action potentials. ET cells excite GABAergic PG cells. Thus, the transformation of inhibitory inputs to postsynaptic excitation in ET cells may enhance intraglomerular inhibition of mitral/tufted cells, the main output neurons in the olfactory bulb, and hence shape signaling to olfactory cortex.

  10. High-Performance All-Solid-State Lithium-Sulfur Battery Enabled by a Mixed-Conductive Li2S Nanocomposite.

    Science.gov (United States)

    Han, Fudong; Yue, Jie; Fan, Xiulin; Gao, Tao; Luo, Chao; Ma, Zhaohui; Suo, Liumin; Wang, Chunsheng

    2016-07-13

    All-solid-state lithium-sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (∼3.6 mg/cm(2)). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.

  11. Quantization and topological states in the spin Hall conductivity of low-dimensional systems: An ab initio study

    Science.gov (United States)

    Matthes, L.; Küfner, S.; Furthmüller, J.; Bechstedt, F.

    2016-03-01

    Ab initio relativistic band structure calculations are performed for the frequency-dependent spin Hall conductivity of two-dimensional atomically thin crystals and one-dimensional nanoribbons. We study the influence of topology, quantization, and topological edge states. As model systems fully halogenated germanene, GeI, and its zigzag nanoribbons are investigated. GeI represents a topological insulator (TI). For comparison, also the TI germanene and the trivial insulator hydrogenated germanene are studied. For the TIs we demonstrate the quantization of the static spin Hall conductivity. It is hardly influenced by temperature and Fermi level shift. Its frequency dependence is governed by the band-structure details. Topological edge states influence the conductivity mainly for vanishing frequencies.

  12. Social Media Activism and State Censorship

    NARCIS (Netherlands)

    T. Poell

    2015-01-01

    This chapter interrogates how activist social media communication in authoritarian contexts is shaped through the mutual articulation of social media user practices, business models, and technological architectures, as well as through the controlling efforts of states. It specifically focuses on soc

  13. Graphene as conductive additives in binderless activated carbon electrodes for power enhancement of supercapacitor

    Science.gov (United States)

    Nor, N. S. M.; Deraman, M.; Suleman, M.; Norizam, M. D. M.; Basri, N. H.; Sazali, N. E. S.; Hamdan, E.; Hanappi, M. F. Y. M.; Tajuddin, N. S. M.; Othman, M. A. R.; Shamsudin, S. A.; Omar, R.

    2016-11-01

    Carbon based supercapacitor electrodes from composite of binderless activated carbon and graphene as a conductive additive were fabricated with various amount of graphene (0, 2, 4, 6, 8 and 10 wt%). Graphene was mixed in self-adhesive carbon grains produced from pre-carbonized powder derived from fibers of oil palm empty fruit bunches and converted into green monoliths (GMs). The GMs were carbonized (N2) and activated (CO2) to produce activated carbon monoliths (ACMs) electrodes. Porosity characterizations by nitrogen adsorption-desorption isotherm method shows that the pore characteristics of the ACMs are influenced by the graphene additive. The results of galvanostatic charge-discharge tests carried out on the supercapacitor cells fabricated using these electrodes shows that the addition of graphene additive (even in small amount) decreases the equivalent series resistance and enhances the specific power of the cells but significantly lowers the specific capacitance. The supercapacitor cell constructed with the electrode containing 4 wt % of graphene offers the maximum power (175 W kg-1) which corresponds to an improvement of 55%. These results demonstrate that the addition of graphene as conductive additive in activated carbon electrodes can enhance the specific power of the supercapacitor.

  14. Steady state method to determine unsaturated hydraulic conductivity at the ambient water potential

    Science.gov (United States)

    HUbbell, Joel M.

    2014-08-19

    The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision. The present invention relates to a new laboratory apparatus for measuring the unsaturated hydraulic conductivity at a single water potential. One or more embodiments of the invented apparatus can be used over a wide range of water potential values within the tensiometric range, requires minimal laboratory preparation, and operates unattended for extended periods with minimal supervision.

  15. All-Solid-State Textile Batteries Made from Nano-Emulsion Conducting Polymer Inks for Wearable Electronics

    Directory of Open Access Journals (Sweden)

    Tapani Ryhänen

    2012-08-01

    Full Text Available A rollable and all-solid-state textile lithium battery based on fabric matrix and polymer electrolyte that allows flexibility and fast-charging capability is reported. When immerged into poly(3,4-ethylenedioxythiophene (PEDOT nano-emulsion inks, an insulating fabric is converted into a conductive battery electrode for a fully solid state lithium battery with the highest specific energy capacity of 68 mAh/g. This is superior to most of the solid-state conducting polymer primary and/or secondary batteries reported. The bending radius of such a textile battery is less than 1.5 mm while lightening up an LED. This new material combination and inherent flexibility is well suited to provide an energy source for future wearable and woven electronics.

  16. Design of DC Conduction Pump for PGSFR Active Decay Heat Removal System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dehee; Hong, Jonggan; Lee, Taeho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    A DC conduction pump has been designed for the ADHRS of PGSFR. A VBA code developed by ANL was utilized to design and optimize the pump. The pump geometry dependent parameters were optimized to minimize the total current while meeting the design requirements. A double-C type dipole was employed to produce the calculated magnetic strength. Numerical simulations for the magnetic field strength and its distribution around the dipole and for the turbulent flow under magnetic force will be carried out. A Direct Current (DC) conduction Electromagnetic Pump (EMP) has been designed for Active Decay Heat Removal System (ADHRS) of PGSFR. The PGSFR has active as well as passive systems for the DHRS. The passive DHRS (PDHRS) works by natural circulation head and the ADHRS is driven by an EMP for the DHRS sodium loop and a blower for the finned-tube sodium-to-air heat exchanger (FHX). An Annular Linear Induction Pump (ALIP) can be also considered for the ADHRS, but DC conduction pump has been chosen. Selection basis of DHRS EMP is addressed and EMP design for single ADHRS loop with 1MWt heat removal capacity is introduced.

  17. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons.

    Directory of Open Access Journals (Sweden)

    Hyeon Seo

    Full Text Available Subdural cortical stimulation (SuCS is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5 that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information.

  18. Direct measurement of surface-state conductance by microscopic four-point probe method

    DEFF Research Database (Denmark)

    Hasegawa, S.; Shiraki, I.; Tanikawa, T.

    2002-01-01

    For in situ measurements of local electrical conductivity of well defined crystal surfaces in ultrahigh vacuum, we have developed microscopic four-point probes with a probe spacing of several micrometres, installed in a scanning-electron - microscope/electron-diffraction chamber. The probe is pre...

  19. A multipoint flux approximation of the steady-state heat conduction equation in anisotropic media

    KAUST Repository

    Salama, Amgad

    2013-03-20

    In this work, we introduce multipoint flux (MF) approximation method to the problem of conduction heat transfer in anisotropic media. In such media, the heat flux vector is no longer coincident with the temperature gradient vector. In this case, thermal conductivity is described as a second order tensor that usually requires, at least, six quantities to be fully defined in general three-dimensional problems. The two-point flux finite differences approximation may not handle such anisotropy and essentially more points need to be involved to describe the heat flux vector. In the framework of mixed finite element method (MFE), the MFMFE methods are locally conservative with continuous normal fluxes. We consider the lowest order Brezzi-Douglas-Marini (BDM) mixed finite element method with a special quadrature rule that allows for nodal velocity elimination resulting in a cell-centered system for the temperature. We show comparisons with some analytical solution of the problem of conduction heat transfer in anisotropic long strip. We also consider the problem of heat conduction in a bounded, rectangular domain with different anisotropy scenarios. It is noticed that the temperature field is significantly affected by such anisotropy scenarios. Also, the technique used in this work has shown that it is possible to use the finite difference settings to handle heat transfer in anisotropic media. In this case, heat flux vectors, for the case of rectangular mesh, generally require six points to be described. Copyright © 2013 by ASME.

  20. Intermediate-Conductance-Ca2-Activated K Channel Intermediate-Conductance Calcium-Activated Potassium Channel (IKCa1) is Upregulated and Promotes Cell Proliferation in Cervical Cancer

    Science.gov (United States)

    Liu, Ling; Zhan, Ping; Nie, Dan; Fan, Lingye; Lin, Hairui; Gao, Lanyang; Mao, Xiguang

    2017-01-01

    Background Accumulating data point to intermediate-conductance calcium-activated potassium channel (IKCa1) as a key player in controlling cell cycle progression and proliferation of human cancer cells. However, the role that IKCa1 plays in the growth of human cervical cancer cells is largely unexplored. Material/Methods In this study, Western blot analysis, immunohistochemical staining, and RT-PCR were first used for IKCa1protein and gene expression assays in cervical cancer tissues and HeLa cells. Then, IKCa1 channel blocker and siRNA were employed to inhibit the functionality of IKCa1 and downregulate gene expression in HeLa cells, respectively. After these treatments, we examined the level of cell proliferation by MTT method and measured IKCa1 currents by conventional whole-cell patch clamp technique. Cell apoptosis was assessed using the Annexin V-FITC/Propidium Iodide (PI) double-staining apoptosis detection kit. Results We demonstrated that IKCa1 mRNA and protein are preferentially expressed in cervical cancer tissues and HeLa cells. We also showed that the IKCa1 channel blocker, clotrimazole, and IKCa1 channel siRNA can be used to suppress cervical cancer cell proliferation and decrease IKCa1 channel current. IKCa1 downregulation by specific siRNAs induced a significant increase in the proportion of apoptotic cells in HeLa cells. Conclusions IKCa1 is overexpressed in cervical cancer tissues, and IKCa1 upregulation in cervical cancer cell linea enhances cell proliferation, partly by reducing the proportion of apoptotic cells. PMID:28280257

  1. Electrical conductivity retention and electrochemical activity of CSA doped graphene/gold nanoparticle@polyaniline composites

    Institute of Scientific and Technical Information of China (English)

    Md. Akherul Islam; M. Ehtisham Khan; Muhammad Mohsin Hossain; Mudassir Hasan

    2016-01-01

    This paper reports the synthesis of CTAB mediated CSA doped PANI and GN/GNP@ PANI composite na-nofibers. The as synthesized composite nanofibers were examined by TEM, SEM, XRD, Raman spectro-scopy;UV–visible diffused reflectance spectroscopy and TGA. The CTAB mediated CSA doped composite nanofibers showed 59% higher DC electrical conductivity at ambient temperature than that of PANI, which might be due to the enhancement in the mobility of the charge carriers and reduction in hopping distance in the composite system. The CTAB mediated CSA doped composite nanofibers compared to PANI was observed to be showing enhanced DC electrical conductivity retention after various cycles of heating, suggesting an enhancement in thermal stability of the composite structure, which could be attributed to the synergistic effect of GN, GNP and PANI. Additionally, the composite nanofibers showed greater electrochemical activity and better capacitive performance and reduced optical bandgap than that of PANI.

  2. Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors

    Directory of Open Access Journals (Sweden)

    Farshad Barzegar

    2015-09-01

    Full Text Available This article is focused on polymer based gel electrolyte due to the fact that polymers are cheap and can be used to achieve extended potential window for improved energy density of the supercapacitor devices when compared to aqueous electrolytes. Electrochemical characterization of a symmetric supercapacitor devices based on activated carbon in different polyvinyl alcohol (PVA based gel electrolytes was carried out. The device exhibited a maximum energy density of 24 Wh kg−1 when carbon black was added to the gel electrolyte as conductive additive. The good energy density was correlated with the improved conductivity of the electrolyte medium which is favorable for fast ion transport in this relatively viscous environment. Most importantly, the device remained stable with no capacitance lost after 10,000 cycles.

  3. Electrical conductivity retention and electrochemical activity of CSA doped graphene/gold nanoparticle@ polyaniline composites

    Directory of Open Access Journals (Sweden)

    Md. Akherul Islam

    2016-08-01

    Full Text Available This paper reports the synthesis of CTAB mediated CSA doped PANI and GN/GNP@ PANI composite nanofibers. The as synthesized composite nanofibers were examined by TEM, SEM, XRD, Raman spectroscopy; UV–visible diffused reflectance spectroscopy and TGA. The CTAB mediated CSA doped composite nanofibers showed 59% higher DC electrical conductivity at ambient temperature than that of PANI, which might be due to the enhancement in the mobility of the charge carriers and reduction in hopping distance in the composite system. The CTAB mediated CSA doped composite nanofibers compared to PANI was observed to be showing enhanced DC electrical conductivity retention after various cycles of heating, suggesting an enhancement in thermal stability of the composite structure, which could be attributed to the synergistic effect of GN, GNP and PANI. Additionally, the composite nanofibers showed greater electrochemical activity and better capacitive performance and reduced optical bandgap than that of PANI.

  4. Rare earth activated sintering of MoSi2 and its electric conductivity

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of rare earth on activation sintering of MoSi2 and electric conductivity of the matrix were analyzed on the basis of a method proposed by German and Munir. The results show that the addition of rare earth could refine the powder size and obviously reduce sintering activation energy of MoSi2 which, for rare earth/MoSi2 system, is 83.1  kJ/mol at 1  200~14  00  ℃, about half of that of pure MoSi2. This decreases the sintering temperature of MoSi2 by about 200  ℃at least, and decreases the resistivity of the matrix as well. The mechanism of rare earth activated sintering of MoSi2 is an integrated process mostly ruled by grain boundary diffusion. When the density of materials is identical, the rare earth addition is found to have no noticeable effect on the electric conductivity of MoSi2.

  5. Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

    Directory of Open Access Journals (Sweden)

    Ebrahimiasl S

    2014-12-01

    Full Text Available Saeideh Ebrahimiasl,1,2 Azmi Zakaria,3 Anuar Kassim,4 Sri Norleha Basri4 1Department of Nanotechnology, Institute of Advanced Technology, Universiti Putra Malaysia, Serdang, Malaysia; 2Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran; 3Department of Physics, Universiti Putra Malaysia, Serdang, Malaysia; 4Department of Chemistry, Universiti Putra Malaysia, Serdang, Malaysia Abstract: An antibacterial and conductive bionanocomposite (BNC film consisting of polypyrrole (Ppy, zinc oxide (ZnO nanoparticles (NPs, and chitosan (CS was electrochemically synthesized on indium tin oxide (ITO glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO–Ppy/CS and ITO–Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%, while it was increased gradually for higher ratios (10, 15, and 20 wt%. The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were

  6. A high performance flexible all solid state supercapacitor based on the MnO2 sphere coated macro/mesoporous Ni/C electrode and ionic conducting electrolyte.

    Science.gov (United States)

    Zhi, Jian; Reiser, Oliver; Wang, Youfu; Hu, Aiguo

    2016-06-09

    A high contact resistance between the active materials and the current collector, a low ionic conductivity of the gel electrolyte, and an impenetrable electrode structure are the three major barriers which greatly limit the capacitance of MnO2 in solid state supercapacitors. As a potential solution to these problems, in this work we report a novel electrode for solid state supercapacitors, based on a ternary system composed of hierarchical MnO2 spheres as the active material, macroporous Ni foam as gel penetrable skeletons and an ordered mesoporous carbon (OMC) membrane as the charge-transport accelerating layer. By employing butyl-3-methylimidazolium chloride (BMIMCl) modified gels as the ionic conducting electrolyte, the utilization efficiency of MnO2 on the specific capacitance was enhanced up to 88% of the theoretical value, delivering a volumetric capacitance of 81 F cm(-3), which is the highest value among MnO2 based solid state supercapacitors. Moreover, such a flexible device exhibits exceptional volumetric energy and power density (6.6 Wh L(-1) and 549 W L(-1), based on the whole device volume) combined with a small capacity loss of 8.5% after 6000 cycles under twisting. These encouraging findings unambiguously overcome the energy bottleneck of MnO2 in solid state supercapacitors, and open up a new application of macro/mesoporous materials in flexible devices.

  7. Conduct and Support of Amphibious Operations from United States Submarines in World War II

    Science.gov (United States)

    2010-11-01

    could not have completed this project without the help and support of my family , the Army Command and General Staff College (CGSC) faculty, the...Carlson, the founding commanding officer of the Second Marine Raider Battalion. Blankfort conducted extensive interviews with Carlson, his family , and many...the ship‘s trim. Limiting movement to fifteen men at a time reduced this affect on the boat‘s angle, but also doubled mealtime .188

  8. Effect of formation characteristics on hydraulic conductivity in unconfined bed in Etchie, rivers state of Nigeria

    Directory of Open Access Journals (Sweden)

    Solomon Ndubuisi Eluozo

    2013-01-01

    Full Text Available Formation characteristics determine the hydraulic conductivity of the soil, the major parameter that determine the rate of hydraulic conductivity of the soil in study location are void ratio and permeability of the soil, degree of void ratio and permeability where determine to evaluate the rate of hydraulic conductivity and storage coefficient,the results from these two parameters  shows the variation deposition of void ratio and permeability in the study location. Ground water hydrogeological data where found to be unavailable in the study area this condition has resulted to a lots of abortive well, this has also cause a lot of abandoned ground water project done by government, this type of economic waste is a serious concern and need to be addressed., the study is imperative because it will improve the result of ground water exploration in the study area, the result from this study will definitely serve as baseline for professional to apply in   the development of ground water system in the study area .

  9. Modified data analysis for thermal conductivity measurements of polycrystalline silicon microbridges using a steady state Joule heating technique.

    Science.gov (United States)

    Sayer, Robert A; Piekos, Edward S; Phinney, Leslie M

    2012-12-01

    Accurate knowledge of thermophysical properties is needed to predict and optimize the thermal performance of microsystems. Thermal conductivity is experimentally determined by measuring quantities such as voltage or temperature and then inferring a thermal conductivity from a thermal model. Thermal models used for data analysis contain inherent assumptions, and the resultant thermal conductivity value is sensitive to how well the actual experimental conditions match the model assumptions. In this paper, a modified data analysis procedure for the steady state Joule heating technique is presented that accounts for bond pad effects including thermal resistance, electrical resistance, and Joule heating. This new data analysis method is used to determine the thermal conductivity of polycrystalline silicon (polysilicon) microbridges fabricated using the Sandia National Laboratories SUMMiT V™ micromachining process over the temperature range of 77-350 K, with the value at 300 K being 71.7 ± 1.5 W/(m K). It is shown that making measurements on beams of multiple lengths is useful, if not essential, for inferring the correct thermal conductivity from steady state Joule heating measurements.

  10. Manipulating the charge state and conductance of a single molecule on a semiconductor surface by electrostatic gating

    Science.gov (United States)

    Martinez-Blanco, Jesus; Nacci, Christophe; Erwin, Steven C.; Kanisawa, Kiyoshi; Locane, Elina; Thomas, Mark; von Oppen, Felix; Brouwer, Piet; Foelsch, Stefan

    2015-03-01

    We studied the charge state and tunneling conductance of single phthalocyanine molecules adsorbed on InAs(111)A using scanning tunneling microscopy (STM) at 5 K. On the InAs(111)A surface, native +1 charged indium adatoms can be repositioned by the STM tip using atom manipulation. This allows us to electrostatically gate an individual adsorbed molecule by placing charged adatoms nearby or, alternatively, by repositioning the molecule within the electrostatic potential landscape created by an STM-engineered adatom corral. By stepwise increasing the gating potential, the molecular charge state can be tuned from neutral to -1, as well as to bistable intermediate states. We find that the molecule changes its orientational conformation when the charge state is switched. Scanning tunneling spectroscopy measurements reveal that the conductance gap of the single-molecule tunneling junction can be precisely controlled by the electrostatic gating. We discuss the observed gating-dependent single-molecule tunneling conductance in terms of charge transport through a gated quantum dot. Granted by the German Research Foundation (FO 362/4-1; SFB 658).

  11. Localization of Ca2+ -activated big-conductance K+ channels in rabbit distal colon

    DEFF Research Database (Denmark)

    Hay-Schmidt, Anders; Grunnet, Morten; Abrahamse, Salomon L

    2003-01-01

    Big-conductance Ca(2+)-activated K(+) channels (BK channels) may play an important role in the regulation of epithelial salt and water transport, but little is known about the expression level and the precise localization of BK channels in epithelia. The aim of the present study was to quantify...... cells. In conclusion, the significant and distinct expression of BK channels in epithelia, combined with their strict regulation, indicate that these channels may play an important role in the overall regulation of salt and water transport....

  12. Entangled States in a Single-Qubit Structure with SQUID Coupled with a Super-conducting Resonator

    Institute of Scientific and Technical Information of China (English)

    SONG Jian-Wen; LIANG Bao-Long; HAI Wen-Hua; WANG Ji-Suo; ZHONG Hong-Hua; MENG Xiang-Guo; LUO Xiao-Bing

    2008-01-01

    In this paper, the number-phase quantization scheme of the mesoscopic circuit, which consists of a single-qubit structure with superconducting quantum interference device coupled with a super-conducting resonator, is given. By introducing a unitary matrix and by means of spectral decomposition, the Hamiltonian operator of the system is exactly formulated in compact forms in spin-1/2 notation. The eigenvalues and the eigenstates of the system are investigated. It is found that using this system the entangled states can not only be prepared, but also be manipulated by tuning the magnetic flux through the super-conducting loop.

  13. A state-space modeling approach to estimating canopy conductance and associated uncertainties from sap flux density data.

    Science.gov (United States)

    Bell, David M; Ward, Eric J; Oishi, A Christopher; Oren, Ram; Flikkema, Paul G; Clark, James S

    2015-07-01

    Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as canopy conductance and transpiration. To address this need, we developed a hierarchical Bayesian State-Space Canopy Conductance (StaCC) model linking canopy conductance and transpiration to tree sap flux density from a 4-year experiment in the North Carolina Piedmont, USA. Our model builds on existing ecophysiological knowledge, but explicitly incorporates uncertainty in canopy conductance, internal tree hydraulics and observation error to improve estimation of canopy conductance responses to atmospheric drought (i.e., vapor pressure deficit), soil drought (i.e., soil moisture) and above canopy light. Our statistical framework not only predicted sap flux observations well, but it also allowed us to simultaneously gap-fill missing data as we made inference on canopy processes, marking a substantial advance over traditional methods. The predicted and observed sap flux data were highly correlated (mean sensor-level Pearson correlation coefficient = 0.88). Variations in canopy conductance and transpiration associated with environmental variation across days to years were many times greater than the variation associated with model uncertainties. Because some variables, such as vapor pressure deficit and soil moisture, were correlated at the scale of days to weeks, canopy conductance responses to individual environmental variables were difficult to interpret in isolation. Still, our results highlight the importance of accounting for uncertainty in models of ecophysiological and ecosystem function where the process of interest, canopy conductance in this case, is not observed directly. The StaCC modeling

  14. Comparative Studies of the Adsorption of Direct Dye on Activated Carbon and Conducting Polymer Composite

    Directory of Open Access Journals (Sweden)

    J. Raffiea Baseri

    2012-01-01

    Full Text Available This study analyses the feasibility of removing Direct Blue 71 from aqueous solution by different adsorbents such as activated carbon (TPAC and Poly pyrrole polymer composite (PPC prepared from Thevetia Peruviana. Batch mode adsorption was performed to investigate the adsorption capacities of these adsorbents by varying initial dye concentration, temperature, agitation time and pH. The performance of TPAC was compared with PPC. Among the adsorbents, PPC had more adsorption capacity (88.24% than TPAC (58.82% at an initial concentration of 50 mg/L and at 30°C. The experimental data best fitted with pseudo second order kinetic model. The adsorption data fitted well for Langmuir adsorption isotherm. Thermodynamic parameters for the adsorbents were also evaluated. The carbon embedded in conducting polymers matrix show better adsorptive properties than activated carbon.

  15. Microwave-assisted solid-state synthesis of oxide ion conducting stabilized bismuth vanadate phases

    Energy Technology Data Exchange (ETDEWEB)

    Vaidhyanathan, B.; Balaji, K.; Rao, K.J. [Indian Inst. of Science, Bangalore (India). Solid State and Structural Chemistry Unit

    1998-11-01

    A microwave-assisted method for the preparation of substituted bismuth vanadates has been described. The method consists of starting with the respective oxides mixed in stoichiometric proportions and exposing the mixture to microwaves. Substitution takes place at the vanadium sites and it has been possible to prepare Ag{sup +}-, Mn{sup 4+}-, Ga{sup 3+}-, Y{sup 3+}-, and Ce{sup 4+}-substituted compounds with up to 10% substitution. Mn{sup 4+}- and Ag{sup +}-substituted compounds are found to exhibit better oxygen ion conductivities than any reported so far in the literature.

  16. Sub-THz thermally activated-electrical conductivity of CdS thin films

    Science.gov (United States)

    Rahman, Rezwanur; Scales, John A.

    2016-08-01

    The electrical conductivity of a CdS thin film controlled by grain structures is essential to enhance its photoconductivity to be able to be fit as a window material in CdS/CdTe heterojunction solar cells. In order to characterize a thin film, electromagnetically, we employed an open cavity resonator with a sub-millimeter Vector Network Analyzer. Our technique is capable of measuring complex dielectric permittivity, ɛ ˜ , of a photovoltaic film as thin as 0.1 μm. We measured the real part of the complex dielectric permittivity, ɛre, and electrical conductivity, σre (derived from the imaginary part, ɛim), of unannealed and annealed CdS films with thicknesses ˜0.15 μm on ˜3 mm thick-borosilicate glass substrates, at room temperature. We obtain the (thermally activated) electrical conductivity between 100 and 312 GHz, which is less in annealed samples than in unannealed ones by ˜2 orders of magnitude. Contrary to our expectations, the carrier concentrations extracted from these data by fitting a Drude model are ˜1016 cm-3 (unannealed) and ˜1014 cm-3 (annealed). We investigate the connection between the grain size and carrier concentration.

  17. OSR1 and SPAK Sensitivity of Large-Conductance Ca2+ Activated K+ Channel

    Directory of Open Access Journals (Sweden)

    Bernat Elvira

    2016-04-01

    Full Text Available Background/Aims: The oxidative stress-responsive kinase 1 (OSR1 and the serine/threonine kinases SPAK (SPS1-related proline/alanine-rich kinase are under the control of WNK (with-no-K [Lys] kinases. OSR1 and SPAK participate in diverse functions including cell volume regulation and neuronal excitability. Cell volume and neuronal excitation are further modified by the large conductance Ca2+-activated K+ channels (maxi K+ channel or BK channels. An influence of OSR1 and/or SPAK on BK channel activity has, however, never been shown. The present study thus explored whether OSR1 and/or SPAK modify the activity of BK channels. Methods: cRNA encoding the Ca2+ insensitive BK channel mutant BKM513I+Δ899-903 was injected into Xenopus laevis oocytes without or with additional injection of cRNA encoding wild-type OSR1 or wild-type SPAK, constitutively active T185EOSR1, catalytically inactive D164AOSR1, constitutively active T233ESPAK or catalytically inactive D212ASPAK. K+ channel activity was measured utilizing dual electrode voltage clamp. Results: BK channel activity in BKM513I+Δ899-903 expressing oocytes was significantly decreased by co-expression of OSR1 or SPAK. The effect of wild-type OSR1/SPAK was mimicked by T185EOSR1 and T233ESPAK, but not by D164AOSR1 or D212ASPAK. Conclusions: OSR1 and SPAK suppress BK channels, an effect possibly contributing to cell volume regulation and neuroexcitability.

  18. State opportunities for action: Update of states' combined heat and power activities

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Elizabeth [American Council for an Energy-Efficient Economy, Washington, D.C. (United States); Elliott, R. Neal [American Council for an Energy-Efficient Economy, Washington, D.C. (United States)

    2003-10-01

    This report updates the review of state policies with regard to CHP that the American Council for and Energy Efficient Economy completed in 2002. It describes the current activities of states with programs during the initial survey and also reviews new programs offered by the states.

  19. Fabrication of Al-Doped ZnO Film with High Conductivity Induced by Photocatalytic Activity

    Science.gov (United States)

    Hong, Jeongsoo; Katsumata, Ken-ichi; Matsushita, Nobuhiro

    2016-10-01

    We have fabricated Al-doped ZnO films by a spin-spray method, achieving high conductivity by Al-ion doping and photocatalytic activity of the ZnO. The surface morphology of the as-deposited films was varied by changing the Al concentration and addition of citrate ions. As-deposited Al-doped ZnO film without citrate ions showed rod array structure with increasing rod width as the Al concentration was increased. Meanwhile, Al-doped ZnO film deposited with addition of citrate ions changed to exhibit dense and continuous surface morphology with high transmittance of 85%. The lowest resistivity recorded for undoped and Al-doped ZnO film was 2.1 × 10-2 Ω cm and 5.9 × 10-3 Ω cm, after ultraviolet (UV) irradiation. The reason for the decreased resistivity is thought to be that Al-ion doping and the photocatalytic activity of ZnO contributed to improve the conductivity.

  20. Stimulating Investment Development through Transformation of State Banks Activity

    Directory of Open Access Journals (Sweden)

    Kulpinska Lidiya K.

    2013-12-01

    Full Text Available The article considers significance of state corporations and state financial institutions in stimulation of investments into the fixed capital of the country and considers problems of increase of efficiency of activity of these institutions in the world and Ukraine. It considers the state sector of the developing countries through the prism of activity of state financial and non-financial corporations. It analyses theories of positive and negative features of carrying out state investing through state-owned banks. It analyses the role of state financial corporations in Ukraine, in particular, in crediting and expansion of the portfolio of acquired governmental bonds and offers ways of its increase in the context of necessity of directing funds into investment development.

  1. Regulation of the membrane insertion and conductance activity of the metamorphic chloride intracellular channel protein CLIC1 by cholesterol.

    Directory of Open Access Journals (Sweden)

    Stella M Valenzuela

    Full Text Available The Chloride Intracellular ion channel protein CLIC1 has the ability to spontaneously insert into lipid membranes from a soluble, globular state. The precise mechanism of how this occurs and what regulates this insertion is still largely unknown, although factors such as pH and redox environment are known contributors. In the current study, we demonstrate that the presence and concentration of cholesterol in the membrane regulates the spontaneous insertion of CLIC1 into the membrane as well as its ion channel activity. The study employed pressure versus area change measurements of Langmuir lipid monolayer films; and impedance spectroscopy measurements using tethered bilayer membranes to monitor membrane conductance during and following the addition of CLIC1 protein. The observed cholesterol dependent behaviour of CLIC1 is highly reminiscent of the cholesterol-dependent-cytolysin family of bacterial pore-forming proteins, suggesting common regulatory mechanisms for spontaneous protein insertion into the membrane bilayer.

  2. Regulation of the membrane insertion and conductance activity of the metamorphic chloride intracellular channel protein CLIC1 by cholesterol.

    Science.gov (United States)

    Valenzuela, Stella M; Alkhamici, Heba; Brown, Louise J; Almond, Oscar C; Goodchild, Sophia C; Carne, Sonia; Curmi, Paul M G; Holt, Stephen A; Cornell, Bruce A

    2013-01-01

    The Chloride Intracellular ion channel protein CLIC1 has the ability to spontaneously insert into lipid membranes from a soluble, globular state. The precise mechanism of how this occurs and what regulates this insertion is still largely unknown, although factors such as pH and redox environment are known contributors. In the current study, we demonstrate that the presence and concentration of cholesterol in the membrane regulates the spontaneous insertion of CLIC1 into the membrane as well as its ion channel activity. The study employed pressure versus area change measurements of Langmuir lipid monolayer films; and impedance spectroscopy measurements using tethered bilayer membranes to monitor membrane conductance during and following the addition of CLIC1 protein. The observed cholesterol dependent behaviour of CLIC1 is highly reminiscent of the cholesterol-dependent-cytolysin family of bacterial pore-forming proteins, suggesting common regulatory mechanisms for spontaneous protein insertion into the membrane bilayer.

  3. Active Learning of Nondeterministic Finite State Machines

    Directory of Open Access Journals (Sweden)

    Warawoot Pacharoen

    2013-01-01

    Full Text Available We consider the problem of learning nondeterministic finite state machines (NFSMs from systems where their internal structures are implicit and nondeterministic. Recently, an algorithm for inferring observable NFSMs (ONFSMs, which are the potentially learnable subclass of NFSMs, has been proposed based on the hypothesis that the complete testing assumption is satisfied. According to this assumption, with an input sequence (query, the complete set of all possible output sequences is given by the so-called Teacher, so the number of times for asking the same query is not taken into account in the algorithm. In this paper, we propose LNM*, a refined ONFSM learning algorithm that considers the amount for repeating the same query as one parameter. Unlike the previous work, our approach does not require all possible output sequences in one answer. Instead, it tries to observe the possible output sequences by asking the same query many times to the Teacher. We have proved that LNM* can infer the corresponding ONFSMs of the unknown systems when the number of tries for the same query is adequate to guarantee the complete testing assumption. Moreover, the proof shows that our algorithm will eventually terminate no matter whether the assumption is fulfilled or not. We also present the theoretical time complexity analysis of LNM*. In addition, experimental results demonstrate the practical efficiency of our approach.

  4. Conductance and activation energy for electron transport in series and parallel intramolecular circuits.

    Science.gov (United States)

    Hsu, Liang-Yan; Wu, Ning; Rabitz, Herschel

    2016-11-30

    We investigate electron transport through series and parallel intramolecular circuits in the framework of the multi-level Redfield theory. Based on the assumption of weak monomer-bath couplings, the simulations depict the length and temperature dependence in six types of intramolecular circuits. In the tunneling regime, we find that the intramolecular circuit rule is only valid in the weak monomer coupling limit. In the thermally activated hopping regime, for circuits based on two different molecular units Ma and Mb with distinct activation energies Eact,a > Eact,b, the activation energies of Ma and Mb in series are nearly the same as Eact,a while those in parallel are nearly the same as Eact,b. This study gives a comprehensive description of electron transport through intramolecular circuits from tunneling to thermally activated hopping. We hope that this work can motivate additional studies to design intramolecular circuits based on different types of building blocks, and to explore the corresponding circuit laws and the length and temperature dependence of conductance.

  5. 2D-local existence and uniqueness of a transient state of a coupled radiative-conductive heat transfer problem

    OpenAIRE

    Ghattassi, Mohamed; Roche, Jean Rodolphe; Schmitt, Didier; Boutayeb, Mohamed

    2016-01-01

    This paper deals with local existence and uniqueness results for a transient two-dimensional combined nonlinear radiative-conductive system. This system describes the heat transfer for a grey, semi-transparent and non-scattering medium with homogeneous Dirichlet boundary conditions. We reformulate the full transient state system as a fixed-point problem. The existence and uniqueness proof rests upon the Banach fixed-point Theorem assuming the initial data T 0 is non-negative and sufficiently ...

  6. Low temperature thermal conductivity of Zn-doped YBCO evidence for impurity-induced electronic bound states

    CERN Document Server

    Behnia, K; Taillefer, L; Gagnon, R

    1996-01-01

    The thermal conductivity of Zn-doped YBCO crystals was studied at low temperature (0.15 < T < 0.8 K) for different concentrations of Zn impurities. A small amount of Zn induces a dramatic decrease in the non-linear component of the low-temperature thermal conductivity. Moreover, the magnitude of the linear component (obtained by extrapolating the data to T=0) is found to depend on Zn concentration. After an initial decrease, this linear term, associated with the electronic contribution to the conductivity, increases with increasing Zn dopage. Such an increase is consistent with the introduction of low-energy excitations by Zn impurities as expected for a $d_{x^2-y^2}$ superconducting state in contrast to an anisotropic s-wave gap. The results are compared to quantitative predictions of available theoretical models.

  7. Research on the Relationship between Density of States and Conducting Properties of Single-walled Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The analytical expression of the electronic density of states (DOS) for single-walled carbon nanotubes (SWNTs) has been derived on the basis of graphene approximation of the energy E(k) near the Fermi level EF. The distinctive properties of the DOS, the normalized differential conductivity and the current vs bias for SWNTs are deduced and analyzed theoretically.The singularities in the DOS (or in the normalized differential conductivity) predict that the jump structure of current (or conductance)-bias of SWNTs exists. All conclusions from the theoretical analysis are in well agreement with the experimental results of SWNT's electronic structure and electronic transport. In other words, the simple theoretical model in this paper can be applied to understand a range of spectroscopic and other measurement data related to the DOS of SWNTs.

  8. CMS Grid Activities in the United States

    Institute of Scientific and Technical Information of China (English)

    I.Fisk; J.Amundson; 等

    2001-01-01

    The CMS groups in the USA are actively involved in several grid-elated projects,including the DoE-funded Particle Physics Data Grid(PPDG)and the NSFfunded Grid Physics Network(GriPhyN).We present developments of :the Grid data Management Pilot (GDMP) software;a Java Analysis Studio-based prototype remote analysis service for CMS data;tools for automating job submission schemes for large scale distributed simulation and reconstruction runs for CMS;modeling and development of job scheduling schemes using the MONARC toolkit;a robust execution service for distributed processors.The deployment and use of these tools at prototype Tier1 and Tier2 computing centers in the USA is described.

  9. A simple model for conduction band states of nitride-based double heteroestructures

    Energy Technology Data Exchange (ETDEWEB)

    Gaggero-Sager, L M; Mora-Ramos, M E, E-mail: lgaggero@uaem.m [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico)

    2009-05-01

    In this work we propose an analytical expression for the approximate modeling of the potential energy function describing conduction band bending in III-V nitride quantum wells. It is an alternative approach to the self-consistent Poisson-Schoedinger calculation. The model considers the influence of the many electron system and the built-in electric field inside the well. Hartree and exchange contributions are included along the lines of a local-density Thomas-Fermi-based theory. The effects due to the modulated doping in the barriers is also considered. We report the calculation of the energy spectrum as a function of several input parameters: alloy composition in the barriers, barrier doping concentration, and quantum well width. Our results could be of usefulness in the study of optoelectronic properties in this kind of systems.

  10. Meshless Least-Squares Method for Solving the Steady-State Heat Conduction Equation

    Institute of Scientific and Technical Information of China (English)

    LIU Yan; ZHANG Xiong; LU Mingwan

    2005-01-01

    The meshless weighted least-squares (MWLS) method is a pure meshless method that combines the moving least-squares approximation scheme and least-square discretization. Previous studies of the MWLS method for elastostatics and wave propagation problems have shown that the MWLS method possesses several advantages, such as high accuracy, high convergence rate, good stability, and high computational efficiency. In this paper, the MWLS method is extended to heat conduction problems. The MWLS computational parameters are chosen based on a thorough numerical study of 1-dimensional problems. Several 2-dimensional examples show that the MWLS method is much faster than the element free Galerkin method (EFGM), while the accuracy of the MWLS method is close to, or even better than the EFGM. These numerical results demonstrate that the MWLS method has good potential for numerical analyses of heat transfer problems.

  11. Carbon monoxide stimulates the Ca2(+)-activated big conductance k channels in cultured human endothelial cells.

    Science.gov (United States)

    Dong, De-Li; Zhang, Yan; Lin, Dao-Hong; Chen, Jun; Patschan, Susann; Goligorsky, Michael S; Nasjletti, Alberto; Yang, Bao-Feng; Wang, Wen-Hui

    2007-10-01

    We used the whole-cell patch-clamp technique to study K channels in the human umbilical vein endothelial cells and identified a 201 pS K channel, which was blocked by tetraethylammonium and iberiotoxin but not by TRAM34 and apamin. This suggests that the Ca(2+)-activated big-conductance K channel (BK) is expressed in endothelial cells. Application of carbon monoxide (CO) or tricarbonylchloro(glycinato)ruthenium(II), a water soluble CO donor, stimulated the BK channels. Moreover, application of hemin, a substrate of heme oxygenase, mimicked the effect of CO and increased the BK channel activity. The stimulatory effect of hemin was significantly diminished by tin mesoporphyrin, an inhibitor of heme oxygenase. To determine whether the stimulatory effect of CO on the BK channel was mediated by NO and the cGMP-dependent pathway, we examined the effect of CO on BK channels in cells treated with, N(G)-nitro-l-arginine methyl ester, 1H(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one, an inhibitor of soluble guanylate cyclase, or KT5823, an inhibitor of protein kinase G. Addition of either diethylamine NONOate or sodium nitroprusside significantly increased BK channel activity. Inhibition of endogenous NO synthesis with N(G)-nitro-l-arginine methyl ester, blocking soluble guanylate cyclase or protein kinase G, delayed but did not prevent the CO-induced activation of BK channels. Finally, application of an antioxidant agent, ebselen, had no effect on CO-mediated stimulation of BK channels in human umbilical vein endothelial cells. We conclude that BK channels are expressed in human umbilical vein endothelial cells and that they are activated by both CO and NO. CO activates BK channels directly, as well as via a mechanism involving NO or the cGMP-dependent pathway.

  12. Recent Advances in Fast Ion Conducting Materials and Devices - Proceedings of the 2nd Asian Conference on Solid State Ionics

    Science.gov (United States)

    Chowdari, B. V. R.; Liu, Qingguo; Chen, Liquan

    The Table of Contents for the book is as follows: * Preface * Invited Papers * Recent Trends in Solid State Ionics * Theoretical Aspects of Fast Ion Conduction in Solids * Chemical Bonding and Intercalation Processes in Framework Structures * Extra-Large Near-Electrode Regions and Diffusion Length on the Solid Electrolyte-Electrode Interface as Studied by Photo-EMF Method * Frequency Response of Glasses * XPS Studies on Ion Conducting Glasses * Characterization of New Ambient Temperature Lithium Polymer-Electrolyte * Recent Development of Polymer Electrolytes: Solid State Voltammetry in Polymer Electrolytes * Secondary Solid State Batteries: From Material Properties to Commercial Development * Silver Vanadium Oxide Bronze and its Applications for Electrochemical Devices * Study on β''-Alumina Solid Electrolyte and β Battery in SIC * Materials for Solid Oxide Fuel Cells * Processing for Super Superionic Ceramics * Hydrogen Production Using Oxide Ionic or Protonic Conductor * Ionically Conductive Sulfide-Based Lithium Glasses * Relation of Conductivity to Structure and Structural Relaxation in Ion-Conducting Glasses * The Mechanism of Ionic Conductivity in Glass * The Role of Synthesis and Structure in Solid State Ionics - Electrodes to Superconductors * Electrochromism in Spin-Coated Thin Films from Peroxo-Poly tungstate Solutions * Electrochemical Studies on High Tc Superconductors * Multivalence Fast Ionic Conductors - Montmorillonites * Contributed Papers * Volt-Ampere Characteristics and Interface Charge Transport in Solid Electrolytes * Internal Friction of Silver Chalcogenides * Thermal Expansion of Ionic and Superionic Solids * Improvement of PEO-LiCF3SO3 Complex Electrolytes Using Additives * Ionic Conductivity of Modified Poly (Methoxy Polyethylene Glycol Methacrylate) s-Lithium Salt Complexes * Solid Polymer Electrolytes of Crosslinked Polyethylene Glycol and Lithium Salts * Single Ionic Conductors Prepared by in Situ Polymerization of Methacrylic Acid

  13. Absorbency and conductivity of quasi-solid-state polymer electrolytes for dye-sensitized solar cells: A characterization review

    Science.gov (United States)

    Mohamad, Ahmad Azmin

    2016-10-01

    The application of quasi-solid state electrolytes for dye-sensitized solar cells opens up an interesting research field to explore, which is evident from the increasing amount of publications on this topic. Since 2010, significant progress has been made with new and more complicated quasi-solid-states materials being produced. The optimization of new materials requires specific characterizations. This review presents a comprehensive overview and recent progress of characterization methods for studying quasi-solid-state electrolytes. Emphasis is then placed on the absorbency and conductivity characterizations. Each characterization will be reviewed according to the objective, experimental set-up, summary of important outcomes, and a few case studies worth discussing. Finally, strategies for future characterizations and developments are described.

  14. Electrical conductivity and Equation of State from Measurements of a Tamped Electrically Exploded Foil

    Science.gov (United States)

    Ruden, Edward; Amdahl, David; Cooksey, Rufus; Domonkos, Matthew; Robinson, Paul; Analla, Francis; Brown, Darwin; Kostora, Mark; Camacho, Frank

    2013-10-01

    Results are presented for an experiment that produces and diagnoses dynamic surface conditions of homogeneous warm dense matter (WDM) to infer intrinsic bulk properties such as density, pressure, temperature, specific energy, electrical conductivity, and emissivity in the ranges of up to few eV and down to 0.1 solid density-typical of those encountered in single shot pulsed power device electrodes. The goal is to validate ab initio models of matter encountered for predictive modeling of such devices. In the test whose results are presented here, the WDM is produced by Ohmically heating and exploding an 80 μm Al foil placed between two fused quartz tampers by the discharge of a 36 μF capacitor bank charged to 30.1 kV and discharged in 2.55 μs to a peak load current of 460 kA. Measurements are presented from two division of amplitude polarimeters which operate at 532 nm and 1064 nm, a complementary pyrometer which measures the spectral radiance ratio at those wavelengths, a long-range 660 nm photonic Doppler velocimeter, and a B-dot probe array from which the aforementioned intrinsic properties may be inferred. Available results are compared to a 3-D MHD ALEGRA simulation of the full dynamic load and return conductor geometry with a two-loop external coupled circuit.

  15. Large-conductance calcium-activated potassium channels facilitate transmitter release in salamander rod synapse.

    Science.gov (United States)

    Xu, Jian Wei; Slaughter, Malcolm M

    2005-08-17

    Large-conductance calcium-activated potassium (BK) channels are colocalized with calcium channels at sites of exocytosis at the presynaptic terminals throughout the nervous system. It is expected that their activation would provide negative feedback to transmitter release, but the opposite is sometimes observed. Attempts to resolve this apparent paradox based on alterations in action potential waveform have been ambiguous. In an alternative approach, we investigated the influence of this channel on neurotransmitter release in a nonspiking neuron, the salamander rod photoreceptors. Surprisingly, the BK channel facilitates calcium-mediated transmitter release from rods. The two presynaptic channels form a positive coupled loop. Calcium influx activates the BK channel current, leading to potassium efflux that increases the calcium current. The normal physiological voltage range of the rod is well matched to the dynamics of this positive loop. When the rod is further depolarized, then the hyperpolarizing BK channel current exceeds its facilitatory effect, causing truncation of transmitter release. Thus, the calcium channel-BK channel linkage performs two functions at the synapse: nonlinear potentiator and safety brake.

  16. Atrial conduction times and left atrium mechanical functions in patients with active acromegaly.

    Science.gov (United States)

    Ilter, A; Kırış, A; Kaplan, Ş; Kutlu, M; Şahin, M; Erem, C; Civan, N; Kangül, F

    2015-03-01

    The aim of this study was to evaluate atrial electromechanical delay (EMD), P wave dispersion (Pwd), and left atrial (LA) mechanical functions in patients with active acromegaly. Twenty-three patients with active acromegaly and 27 age- and sex-matched controls were included in this study. All atrial electromechanical interval parameters (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) were measured from mitral lateral annulus, mitral septal annulus, and right ventricular tricuspid annulus by tissue Doppler imaging. LA volumes were measured by the disk method in the apical four-chamber view and were indexed to the body surface area. Mechanical function parameters of LA were calculated. Pwd was performed by 12-lead electrocardiograms. Atrial electromechanical intervals (PA lateral, PA septum, PA tricuspid, interatrial EMD, intra-LA EMD, and intra-right atrial EMD) and Pwd were similar between patients with acromegaly and control subjects (all p > 0.05). LA volumes (maximum, minimum, and presystolic) and LA mechanical functions were not significantly different between the groups (all p > 0.05). Additionally, serum levels of growth hormone and insulin-like growth factor-1 were not correlated with atrial electromechanical parameters and LA mechanical functions. Atrial electrical conduction times were not prolonged and LA mechanical functions were not impaired in patients with active acromegaly compared with controls. And the prevalence of supraventricular arrhythmia risk may not increase in this population.

  17. PLRP-3: Operational Perspectives of Conducting Science-Driven Extravehicular Activity with Communications Latency

    Science.gov (United States)

    Miller, Matthew J.; Lim, Darlene S. S.; Brady, Allyson; Cardman, Zena; Bell, Ernest; Garry, Brent; Reid, Donnie; Chappell, Steve; Abercromby, Andrew F. J.

    2016-01-01

    The Pavilion Lake Research Project (PLRP) is a unique platform where the combination of scientific research and human space exploration concepts can be tested in an underwater spaceflight analog environment. The 2015 PLRP field season was performed at Pavilion Lake, Canada, where science-driven exploration techniques focusing on microbialite characterization and acquisition were evaluated within the context of crew and robotic extravehicular activity (EVA) operations. The primary objectives of this analog study were to detail the capabilities, decision-making process, and operational concepts required to meet non-simulated scientific objectives during 5-minute one-way communication latency utilizing crew and robotic assets. Furthermore, this field study served as an opportunity build upon previous tests at PLRP, NASA Desert Research and Technology Studies (DRATS), and NASA Extreme Environment Mission Operations (NEEMO) to characterize the functional roles and responsibilities of the personnel involved in the distributed flight control team and identify operational constraints imposed by science-driven EVA operations. The relationship and interaction between ground and flight crew was found to be dependent on the specific scientific activities being addressed. Furthermore, the addition of a second intravehicular operator was found to be highly enabling when conducting science-driven EVAs. Future human spaceflight activities will need to cope with the added complexity of dynamic and rapid execution of scientific priorities both during and between EVA execution to ensure scientific objectives are achieved.

  18. Extracellular K+ activates a K(+)- and H(+)-permeable conductance in frog taste receptor cells.

    Science.gov (United States)

    Kolesnikov, S S; Margolskee, R F

    1998-03-01

    1. The effect of extracellular K+ on membrane currents of bull frog (Rana catesbeiana) taste receptor cells (TRCs) was investigated by the patch clamp and fast perfusion techniques. Extracellular K+ (2.5-90 mM) increased a TRC resting conductance and enhanced both inward and outward whole-cell currents. 2. To isolate the inward current activated by external potassium (PA current), TRCs were dialysed with 110 mM NMGCl while extracellular NaCl was replaced with NMGCl. Under these conditions, the PA current displayed an S-shaped current-voltage (I-V) curve in the -100 to 100 mV range. Extracellular Rb+ and NH4+, but not Li+, Na+ or Cs+, evoked similar currents. 3. The PA current reversal potential (Vr) did not follow the equilibrium K+ potential under experimental conditions. Therefore, K+ ions were not the only current carriers. The influence of other ions on the PA current Vr indicated that the channels involved are permeable to K+ and H+ and much less so to Na+, Ca2+ and Mg2+. Relative permeabilities were estimated on the basis of the Goldman-Hodgkin-Katz equation as follows: PH:PK:PNa = 4000:1:0.04. 4. All I-V curves of the PA current were nearly linear at low negative potentials. The slope conductance at these voltages was used to characterize the dependence of the PA current on external K+ and H+. The slope conductance versus K+ concentration was fitted by the Hill equation. The data yielded a half-maximal concentration, K1/2 = 19 +/- 3 mM and a Hill coefficient, nH = 1.53 +/- 0.36 (means +/- S.E.M.). 5. The dependence of the mean PA current and the current variance on the K+ concentration indicated a rise in the open probability of the corresponding channels as extracellular K+ was increased. With 110 mM KCl in the bath, the single channel conductance was estimated at about 6 pS. Taken together, the data suggest that extracellular K+ may serve as a ligand to activate specific small-conductance cation channels (PA channels). The mean number of the PA channels

  19. Room temperature solid-state synthesis of a conductive polymer for applications in stable I₂-free dye-sensitized solar cells.

    Science.gov (United States)

    Kim, Byeonggwan; Koh, Jong Kwan; Kim, Jeonghun; Chi, Won Seok; Kim, Jong Hak; Kim, Eunkyoung

    2012-11-01

    A solid-state polymerizable monomer, 2,5-dibromo-3,4-propylenedioxythiophene (DBProDOT), was synthesized at 25 °C to produce a conducting polymer, poly(3,4-propylenedioxythiophene) (PProDOT). Crystallographic studies revealed a short interplane distance between DBProDOT molecules, which was responsible for polymerization at low temperature with a lower activation energy and higher exothermic reaction than 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) or its derivatives. Upon solid-state polymerization (SSP) of DBProDOT at 25 °C, PProDOT was obtained in a self-doped state with tribromide ions and an electrical conductivity of 0.05 S cm⁻¹, which is considerably higher than that of chemically-polymerized PProDOT (2×10⁻⁶ S cm⁻¹). Solid-state ¹³C NMR spectroscopy and DFT calculations revealed polarons in PProDOT and a strong perturbation of carbon nuclei in thiophenes as a result of paramagnetic broadening. DBProDOT molecules deeply penetrated and polymerized to fill nanocrystalline TiO₂ pores with PProDOT, which functioned as a hole-transporting material (HTM) for I₂-free solid-state dye-sensitized solar cells (ssDSSCs). With the introduction of an organized mesoporous TiO₂ (OM-TiO₂) layer, the energy conversion efficiency reached 3.5 % at 100 mW cm⁻², which was quite stable up to at least 1500 h. The cell performance and stability was attributed to the high stability of PProDOT, with the high conductivity and improved interfacial contact of the electrode/HTM resulting in reduced interfacial resistance and enhanced electron lifetime.

  20. Calmodulin mediates calcium-dependent activation of the intermediate conductance KCa channel, IKCa1.

    Science.gov (United States)

    Fanger, C M; Ghanshani, S; Logsdon, N J; Rauer, H; Kalman, K; Zhou, J; Beckingham, K; Chandy, K G; Cahalan, M D; Aiyar, J

    1999-02-26

    Small and intermediate conductance Ca2+-activated K+ channels play a crucial role in hyperpolarizing the membrane potential of excitable and nonexcitable cells. These channels are exquisitely sensitive to cytoplasmic Ca2+, yet their protein-coding regions do not contain consensus Ca2+-binding motifs. We investigated the involvement of an accessory protein in the Ca2+-dependent gating of hIKCa1, a human intermediate conductance channel expressed in peripheral tissues. Cal- modulin was found to interact strongly with the cytoplasmic carboxyl (C)-tail of hIKCa1 in a yeast two-hybrid system. Deletion analyses defined a requirement for the first 62 amino acids of the C-tail, and the binding of calmodulin to this region did not require Ca2+. The C-tail of hSKCa3, a human neuronal small conductance channel, also bound calmodulin, whereas that of a voltage-gated K+ channel, mKv1.3, did not. Calmodulin co-precipitated with the channel in cell lines transfected with hIKCa1, but not with mKv1. 3-transfected lines. A mutant calmodulin, defective in Ca2+ sensing but retaining binding to the channel, dramatically reduced current amplitudes when co-expressed with hIKCa1 in mammalian cells. Co-expression with varying amounts of wild-type and mutant calmodulin resulted in a dominant-negative suppression of current, consistent with four calmodulin molecules being associated with the channel. Taken together, our results suggest that Ca2+-calmodulin-induced conformational changes in all four subunits are necessary for the channel to open.

  1. 34 CFR 300.812 - Reservation for State activities.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Reservation for State activities. 300.812 Section 300.812 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION...

  2. 34 CFR 300.814 - Other State-level activities.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Other State-level activities. 300.814 Section 300.814 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION...

  3. A Semi-Conductive Copper-Organic Framework with Two Types of Photocatalytic Activity.

    Science.gov (United States)

    Wu, Zhi-Lei; Wang, Chang-Hong; Zhao, Bin; Dong, Jie; Lu, Feng; Wang, Wei-Hua; Wang, Wei-Chao; Wu, Guang-Jun; Cui, Jian-Zhong; Cheng, Peng

    2016-04-11

    Based on the newly designed ligand 4'-(3,5-dicarboxyphenyl)-4,2':6',4''-terpyridine (DCTP), a unique semi-conductive 3D framework {[Cu(Ι)Cu(ΙΙ)2(DCTP)2]NO3⋅1.5 DMF}n (1) with a narrow band gap of 2.1 eV, was obtained and structurally characterized. DFT calculations with van de Waals correction employed to explore the electronic structure of 1, clearly revealed its semi-conductive behavior. Furthermore, we found that 1 exhibits a superior band alignment with water to produce hydrogen and degrade organic pollutants. Without adding any photosensitizers, 1 displays an efficiently photocatalytic hydrogen production in water based on the photo-generated electrons under UV/Vis light. 1 also exhibits excellent photo-degradation of methyl blue under visible-light owing to the strong oxidization of excited holes. It is the first example of MOFs with doubly photocatalytic activities related to photo-generated electrons and holes, respectively.

  4. Preparation of reusable conductive activated charcoal plate as a new electrode for industrial wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ayoubi-Feiz, Baharak; Aber, Soheil [University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2015-10-15

    A conductive activated charcoal plate (ACP) was prepared from a low-cost, abundant, and non-conductive charcoal. The prepared ACP was characterized using N{sub 2} adsorption/desorption isotherms, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Brunauer-Emmett-Teller (BET) surface area of the charcoal and the ACP was 0.58m{sup 2} g{sup -1} and 461.67m{sup 2} g{sup -1}, respectively. The ACP was employed in textile wastewater treatment using electrosorption process. Response surface methodology (RSM) was applied to design the experiments. The decolorization efficiency of 76% at optimum conditions of voltage=450mV, pH=4, and contact time=120 min indicated that the ACP has promising potential to decolorize textile wastewater. Moreover, the results of the kinetic analyses demonstrated that wastewater treatment followed pseudo-first order kinetic model. The ACP electrode could be regenerated and reused effectively at five successive cycles of electrosorption/electrodesorption.

  5. Electrical Conductivity of Rocks and Dominant Charge Carriers. Part 1; Thermally Activated Positive Holes

    Science.gov (United States)

    Freund, Friedemann T.; Freund, Minoru M.

    2012-01-01

    The prevailing view in the geophysics community is that the electrical conductivity structure of the Earth's continental crust over the 5-35 km depth range can best be understood by assuming the presence of intergranular fluids and/or of intragranular carbon films. Based on single crystal studies of melt-grown MgO, magma-derived sanidine and anorthosite feldspars and upper mantle olivine, we present evidence for the presence of electronic charge carriers, which derive from peroxy defects that are introduced during cooling, under non-equilibrium conditions, through a redox conversion of pairs of solute hydroxyl arising from dissolution of H2O.The peroxy defects become thermally activated in a 2-step process, leading to the release of defect electrons in the oxygen anion sublattice. Known as positive holes and symbolized by h(dot), these electronic charge carriers are highly mobile. Chemically equivalent to O(-) in a matrix of O(2-) they are highly oxidizing. Being metastable they can exist in the matrix of minerals, which crystallized in highly reduced environments. The h(dot) are highly mobile. They appear to control the electrical conductivity of crustal rocks in much of the 5-35 km depth range.

  6. Innovation Activity in the Republic of Kazakhstan: State Controlling and Ways to Increase Management Efficiency

    Directory of Open Access Journals (Sweden)

    DANA SAYLAUOVNA BEKNIYAZOVA

    2016-04-01

    Full Text Available The main goal of the research is to reveal the dominant role of the state in the innovational development of the country and to define promising areas of the cooperation between the state, universities (research institutes and industry in conducting the research activity. At the present time the innovation activity is a locomotive of progressive phenomena in the economy of the country. Herewith, it is noted that in the Republic of Kazakhstan innovation activity, according to its indicators, falls behind the desired efficient result. This article defines the level of the development of innovation entrepreneurship activity in Kazakhstan. It states the problems related to the innovation development due to the current tendencies of the development of economy in the world. It offers measures for stable and dynamic development of the country that includes the notion of the competitiveness and development of innovational schemes of development that are based on efficient interrelation and optimal combination of interests of the state, universities (research institutes and private sector of Kazakhstan. On the basis of the conducted analysis of variables – factors of innovational development - it was revealed that the efficiency of managing innovation activity by governmental authorities was a “primal cause” that had an impact on such indicators as the level of development of innovational infrastructure and wealth of the country. The authors also proposed the measures of state regulation of the innovation development of enterprises and stimulation of partnership of the science with the production.

  7. Observation of conducting edge states in graphene at zero magnetic field

    Science.gov (United States)

    Allen, Monica; Fulga, Ion; Shtanko, Oles; Watanabi, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo; Akhmerov, Anton; Levitov, Leonid; Yacoby, Amir

    2015-03-01

    The electronic nature of edge states confined to the boundaries of a graphene crystal remains an outstanding question. Proposals range from Anderson localization to chiral zero-energy edge modes, but a full microscopic picture of edge transport remains elusive. We directly image current transmission in real space by coupling superconducting electrodes to a graphene crystal and measuring quantum interference as a function of applied magnetic flux. To obtain a more quantitative picture, we employ Fourier techniques to extract the real space current distribution with nanoscale precision. We observe robust confinement of current to the edges of the crystal approaching the Dirac point and show that relative edge and bulk contributions are tunable via electrostatic gating. A strong candidate consistent with our data is the proposal of chiral edge modes that arise from sublattice symmetry breaking at the edge, sustained in all crystallographic edge orientations except atomically perfect armchair. Our techniques also open the door to fast spatial imaging of current distributions along more complicated networks of domains in larger crystals.

  8. Flexible, solid-state, ion-conducting membrane with 3D garnet nanofiber networks for lithium batteries

    Science.gov (United States)

    Kun, Kelvin; Gong, Yunhui; Dai, Jiaqi; Gong, Amy; Han, Xiaogang; Yao, Yonggang; Wang, Chengwei; Wang, Yibo; Chen, Yanan; Yan, Chaoyi; Li, Yiju; Wachsman, Eric D.; Hu, Liangbing

    2016-06-01

    Beyond state-of-the-art lithium-ion battery (LIB) technology with metallic lithium anodes to replace conventional ion intercalation anode materials is highly desirable because of lithium's highest specific capacity (3,860 mA/g) and lowest negative electrochemical potential (˜3.040 V vs. the standard hydrogen electrode). In this work, we report for the first time, to our knowledge, a 3D lithium-ion-conducting ceramic network based on garnet-type Li6.4La3Zr2Al0.2O12 (LLZO) lithium-ion conductor to provide continuous Li+ transfer channels in a polyethylene oxide (PEO)-based composite. This composite structure further provides structural reinforcement to enhance the mechanical properties of the polymer matrix. The flexible solid-state electrolyte composite membrane exhibited an ionic conductivity of 2.5 × 10-4 S/cm at room temperature. The membrane can effectively block dendrites in a symmetric Li | electrolyte | Li cell during repeated lithium stripping/plating at room temperature, with a current density of 0.2 mA/cm2 for around 500 h and a current density of 0.5 mA/cm2 for over 300 h. These results provide an all solid ion-conducting membrane that can be applied to flexible LIBs and other electrochemical energy storage systems, such as lithium-sulfur batteries.

  9. Numerical Simulation of Steady State Conduction Heat Transfer During the Solidification of Aluminum Casting in Green Sand Mould

    Directory of Open Access Journals (Sweden)

    Victor ANJO

    2012-08-01

    Full Text Available The solidification of molten metal during the casting process involves heat transfer from the molten metal to the mould, then to the atmosphere. The mechanical properties and grain size of metals are determined by the heat transfer process during solidification. The aim of this study is to numerically stimulate the steady conduction heat transfer during the solidification of aluminum in green sand mould using finite difference analysis 2D. The properties of materials used are industrial AI 50/60 AFS green sand mould, pure aluminum and MATLAB 7.0.1. for the numerical simulation. The method includes; the finite difference analysis of the heat conduction equation in steady (Laplace’s and transient states and using MATLAB to numerically stimulate the thermal flow and cooling curve. The results obtained are: the steady state thermal flow in 2D and transient state cooling curve of casting. The results obtain were consider relevant in the control of the grain size and mechanical properties of the casting.

  10. Molecular mechanisms of diabetic coronary dysfunction due to large conductance Ca2+-activated K+ channel impairment

    Institute of Scientific and Technical Information of China (English)

    WANG Ru-xing; ZHENG Jie; GUO Su-xia; LI Xiao-rong; LU Tong; SHI Hai-feng; CHAI Qiang; WU Ying; SUN Wei; JI Yuan; YAO Yong; LI Ku-lin; ZHANG Chang-ying

    2012-01-01

    Background Diabetes mellitus is associated with coronary dysfunction,contributing to a 2- to 4-fold increase in the risk of coronary heart diseases.The mechanisms by which diabetes induces vasculopathy involve endothelial-dependent and -independent vascular dysfunction in both type 1 and type 2 diabetes mellitus.The purpose of this study is to determine the role of vascular large conductance Ca2+-activated K+ (BK) channel activities in coronary dysfunction in streptozotocin-induced diabetic rats.Methods Using videomicroscopy,immunoblotting,fluorescent assay and patch clamp techniques,we investigated the coronary BK channel activities and BK channel-mediated coronary vasoreactivity in streptozotocin-induced diabetic rats.Results BK currents (defined as the iberiotoxin-sensitive K+ component) contribute (65±4)% of the total K+ currents in freshly isolated coronary smooth muscle cells and >50% of the contraction of the inner diameter of coronary arteries from normal rats.However,BK current density is remarkably reduced in coronary smooth muscle cells of streptozotocin-induced diabetic rats,leading to an increase in coronary artery tension.BK channel activity in response to free Ca2+ is impaired in diabetic rats.Moreover,cytoplasmic application of DHS-1 (a specific BK channel β1 subunit activator) robustly enhanced the open probability of BK channels in coronary smooth muscle cells of normal rats.In diabetic rats,the DHS-1 effect was diminished in the presence of 200 nmol/L Ca2+ and was significantly attenuated in the presence of high free calcium concentration,i.e.,1 μmol/L Ca2+.Immunoblotting experiments confirmed that there was a 2-fold decrease in BK-β1 protein expression in diabetic vessels,without altering the BK channel α-subunit expression.Although the cytosolic Ca2+ concentration of coronary arterial smooth muscle cells was increased from (103±23)nmol/L (n=5) of control rats to (193±22) nmol/L (n=6,P<0.05) of STZ-induced diabetic rats,reduced BK

  11. State-dependent cellular activity patterns of the cat paraventricular hypothalamus measured by reflectance imaging

    DEFF Research Database (Denmark)

    Kristensen, Morten Pilgaard; Rector, D M; Poe, G R;

    1996-01-01

    Activity within the cat paraventricular hypothalamus (PVH) during sleep and waking states was measured by quantifying intrinsic tissue reflectivity. A fiber optic probe consisting of a 1.0 mm coherent image conduit, surrounded by plastic fibers which conducted 660 nm source light, was attached...... to a charge-coupled device camera, and positioned over the PVH in five cats. Electrodes for assessing state variables, including electroencephalographic activity, eye movement, and somatic muscle tone were also placed. After surgical recovery, reflected light intensity was measured continuously at 2.5 Hz...

  12. The large conductance calcium-activated K(+) channel interacts with the small GTPase Rab11b.

    Science.gov (United States)

    Sokolowski, Sophia; Harvey, Margaret; Sakai, Yoshihisa; Jordan, Amy; Sokolowski, Bernd

    2012-09-21

    The transduction of sound by the receptor or hair cells of the cochlea leads to the activation of ion channels found in the basal and lateral regions of these cells. Thus, the processing of these transduced signals to the central nervous system is tied to the regulation of baso-lateral ion channels. The large conductance calcium-activated potassium or BK channel was revealed to interact with the small GTPase, Rab11b, which is one of many Rabs found in various endosomal pathways. Immunoelectron microscopy showed the colocalization of these two proteins in receptor cells and auditory neurons. Using Chinese hamster ovary cells as a heterologous expression system, Rab11b increased or decreased BK expression, depending on the overexpression or RNAi knockdown of Rab, respectively. Additional mutation analyses, using a yeast two-hybrid assay, suggested that this GTPase moderately interacts within a region of BK exclusive of the N- or C-terminal tails. These data suggest that this small GTPase regulates BK in a slow recycling process through the endocytic compartment and to the plasmalemma.

  13. Low skin conductance activity in infancy predicts aggression in toddlers 2 years later.

    Science.gov (United States)

    Baker, Erika; Shelton, Katherine H; Baibazarova, Eugenia; Hay, Dale F; van Goozen, Stephanie H M

    2013-06-01

    Low autonomic nervous system activity is claimed to be a biomarker for aggressive and antisocial behavior. Although there is evidence that low skin conductance activity (SCA) accounts for variation in the severity of antisocial behavior and predicts the onset of aggression in children and adults, it is unknown whether SCA measured in infancy can predict the development of aggression. We measured SCA in 70 typically developing 1-year-old infants at baseline, during an orienting habituation paradigm, and during a fear challenge. We also observed the infants' fear behavior, and each mother rated her infant's temperament and her attachment to her child. At follow-up, mothers rated the children at 3 years old for aggressive and nonaggressive behavior problems. Low infant SCA predicted aggressive behavior, but there was no association between SCA and nonaggressive behavior problems. Mothers' ratings of the infants' temperament and their maternal attachment and the infants' observed fearlessness did not predict later aggression. These results suggest that SCA is a specific biomarker for aggression in low-risk samples of infants.

  14. On the way of classifying new states of active matter

    Science.gov (United States)

    Menzel, Andreas M.

    2016-07-01

    With ongoing research into the collective behavior of self-propelled particles, new states of active matter are revealed. Some of them are entirely based on the non-equilibrium character and do not have an immediate equilibrium counterpart. In their recent work, Romanczuk et al (2016 New J. Phys. 18 063015) concentrate on the characterization of smectic-like states of active matter. A new type, referred to by the authors as smectic P, is described. In this state, the active particles form stacked layers and self-propel along them. Identifying and classifying states and phases of non-equilibrium matter, including the transitions between them, is an up-to-date effort that will certainly extend for a longer period into the future.

  15. Correlation of ion-ion interaction with electrical conductivity in solid state polymeric separator for energy storage applications

    Science.gov (United States)

    Sharma, Parul Kumar; Sadiq, M.; Bhatt, Chandni; Sharma, A. L.

    2016-05-01

    In the present study, we report innovative study on the prepared high quality solid state free standing thin polymeric separator. In prepared free standing polymeric separator, polymer (PEO) has been used as host matrix; appropriate bulky anion salt (LiPF6) as conducting species and Nano ceramic filler (BaTiO3) is used to enrich the mechanical and thermal stability of separator used for the device applications. The Fourier Transform Infra-Red (FTIR) result has been analysed properly of the prepared materials to look the microscopic interaction among polymer-ion, ion-ion and polymer-ion-clay interaction. Electrical conductivity results has been recorded using the impedance spectroscopy results which gives the estimated value of the order of ˜10-3 Scm-1 of the nano ceramic doped polymeric separator which is desirable for energy storage application. A fine correlation has been established between the obtained results by this two analysis.

  16. 30 CFR 250.210 - If I conduct ancillary activities, what reporting and data/information retention requirements...

    Science.gov (United States)

    2010-07-01

    ... OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Ancillary Activities § 250.210 If I conduct ancillary activities, what reporting and data/information retention requirements must I satisfy? (a... data or information obtained or derived from your ancillary activities. When applicable, MMS...

  17. Reforma do estado e condução política State reform and political conduct

    Directory of Open Access Journals (Sweden)

    Norbert Lechner

    1996-01-01

    Full Text Available Aponta-se como dimensão básica do poder do Estado a capacidade de conduzir os processos sociais. Argumenta-se que esta dimensão volta à centralidade após a onda "neoliberal". Discutem-se os problemas da reconstituição dessa capacidade em condições de crescente complexidade.The power of the state is seen as basically the ability to conduct social processes. It is argued that this dimension regains its centrality after the "neoliberal" wave. The problems in the reconstitution of this capacity in conditions of growing complexity are discussed.

  18. Reforma do estado e condução política State reform and political conduct

    OpenAIRE

    Norbert Lechner

    1996-01-01

    Aponta-se como dimensão básica do poder do Estado a capacidade de conduzir os processos sociais. Argumenta-se que esta dimensão volta à centralidade após a onda "neoliberal". Discutem-se os problemas da reconstituição dessa capacidade em condições de crescente complexidade.The power of the state is seen as basically the ability to conduct social processes. It is argued that this dimension regains its centrality after the "neoliberal" wave. The problems in the reconstitution of this capacity i...

  19. Quasi-Classical Calculation of the Mixed-State Thermal Conductivity in s- and d-Wave Superconductors

    Science.gov (United States)

    Adachi, Hiroto; Miranović, Predrag; Ichioka, Masanori; Machida, Kazushige

    2007-06-01

    To see how superconducting gap structures affect the longitudinal component of mixed-state thermal conductivity κxx(B), the magnetic-field dependences of κxx(B) in s- and d-wave superconductors are investigated. Calculations are performed on the basis of the quasi-classical theory of superconductivity by fully taking account of the spatial variation of the normal Green’s function, neglected in previous works, by the Brandt-Pesch-Tewordt approximation. On the basis of our result, we discuss the possibility of κxx(B) measurement as a method of probing the gap structure.

  20. A high performance flexible all solid state supercapacitor based on the MnO2 sphere coated macro/mesoporous Ni/C electrode and ionic conducting electrolyte

    Science.gov (United States)

    Zhi, Jian; Reiser, Oliver; Wang, Youfu; Hu, Aiguo

    2016-06-01

    A high contact resistance between the active materials and the current collector, a low ionic conductivity of the gel electrolyte, and an impenetrable electrode structure are the three major barriers which greatly limit the capacitance of MnO2 in solid state supercapacitors. As a potential solution to these problems, in this work we report a novel electrode for solid state supercapacitors, based on a ternary system composed of hierarchical MnO2 spheres as the active material, macroporous Ni foam as gel penetrable skeletons and an ordered mesoporous carbon (OMC) membrane as the charge-transport accelerating layer. By employing butyl-3-methylimidazolium chloride (BMIMCl) modified gels as the ionic conducting electrolyte, the utilization efficiency of MnO2 on the specific capacitance was enhanced up to 88% of the theoretical value, delivering a volumetric capacitance of 81 F cm-3, which is the highest value among MnO2 based solid state supercapacitors. Moreover, such a flexible device exhibits exceptional volumetric energy and power density (6.6 Wh L-1 and 549 W L-1, based on the whole device volume) combined with a small capacity loss of 8.5% after 6000 cycles under twisting. These encouraging findings unambiguously overcome the energy bottleneck of MnO2 in solid state supercapacitors, and open up a new application of macro/mesoporous materials in flexible devices.A high contact resistance between the active materials and the current collector, a low ionic conductivity of the gel electrolyte, and an impenetrable electrode structure are the three major barriers which greatly limit the capacitance of MnO2 in solid state supercapacitors. As a potential solution to these problems, in this work we report a novel electrode for solid state supercapacitors, based on a ternary system composed of hierarchical MnO2 spheres as the active material, macroporous Ni foam as gel penetrable skeletons and an ordered mesoporous carbon (OMC) membrane as the charge-transport accelerating

  1. Overcoming the Challenges of Conducting Early Feasibility Studies of Medical Devices in the United States.

    Science.gov (United States)

    Holmes, David R; Califf, Robert; Farb, Andrew; Abel, Dorothy; Mack, Michael; Syrek Jensen, Tamara; Zuckerman, Bram; Leon, Martin; Shuren, Jeff

    2016-10-25

    Initial clinical studies of new medical technologies involve a complex balance of research participant benefits versus risks and costs of uncertainty when novel concepts are tested. The Food and Drug Administration Center for Devices and Radiological Health has recently introduced the Early Feasibility Study (EFS) Program for facilitating the conduct of these studies under the Investigational Device Exemption regulations. However, a systematic approach is needed to successfully implement this program while affording appropriate preservation of the rights and interests of patients. For this to succeed, a holistic reform of the clinical studies ecosystem for performing early-stage clinical research in the United States is necessary. The authors review the current landscape of the U.S. EFS and make recommendations for developing an efficient EFS process to meet the goal of improving access to early-stage, potentially beneficial medical devices in the United States.

  2. Intrinsic conduction through topological surface states of insulating Bi{sub 2}Te{sub 3} epitaxial thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hoefer, Katharina; Becker, Christoph; Rata, Diana; Thalmeier, Peter; Tjeng, Liu Hao [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Swanson, Jesse [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); University of British Columbia, Vancouver (Canada)

    2015-07-01

    Topological insulators represent a new state of matter that open up new opportunities to create unique quantum particles. Many exciting experiments have been proposed by theory, yet, the main obstacle for their execution is material quality and cleanliness of the experimental conditions. The presence of tiny amounts of defects in the bulk or contaminants at the surface already mask these phenomena. We present the preparation, structural and spectroscopic characterisation of MBE-grown Bi{sub 2}Te{sub 3} thin films that are insulating in the bulk. Moreover, temperature dependent four-point-probe resistivity measurements of the Dirac states on surfaces that are intrinsically clean were conducted. The total amount of surface charge carries is in the order of 10{sup 12} cm{sup -2} and mobilities up to 4600 cm{sup 2}/Vs are observed. Importantly, these results are achieved by carrying out the preparation and characterisation all in-situ under ultra-high-vacuum conditions.

  3. 77 FR 43238 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Science.gov (United States)

    2012-07-24

    ... Specified Activities; Navy Training Conducted at the Silver Strand Training Complex, San Diego Bay AGENCY... harassment, incidental to conducting training exercises at the Silver Strand Training Complex (SSTC) in the... of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring,...

  4. Confrontation Between Judicial Activism and State of Exception

    Directory of Open Access Journals (Sweden)

    Alexandre Pedro Moura D’Almeida

    2017-01-01

    Full Text Available The judiciary has excelled in the international and national scene, reaching role of great importance, thus creating opposition to the legislative and executive powers. The center of gravity of the sovereign power of the state moves toward the judiciary, that happens to have a more active role and controlling of the others powers, but also appears as a great defender of social and fundamental rights causes, seeking to make an effective constitution. Its great public notoriety has attracted great distrust of various sectors of society, especially by the two powers that have an increasing interference. Arises, therefore, a speech that the judiciary would be reversing into a big and uncontrollable power, increasing the suspicion that now it would be living in a real dictatorship of the judiciary through judicial activism. There is a growing concern with the expansion of activism and the role of the judiciary. The purpose of this work is to conceptualize and approach the judicial activism and the state of exception to search and reveal if there is any similarity, to then draw up a possible answer to the concern of forming a dictatorship of the judiciary. The state of exception is one of the rule of law paradoxes, while activism is a political manifestation of the judiciary. The similarity between the institutes appears as appalling in a dynamic expansion of political power of a state institution exercising judicial function, putting in check who would be the sovereign in a rule of law and democratic state.

  5. Mechanisms of electrical activation and conduction in the gastrointestinal system: lessons from cardiac electrophysiology

    Directory of Open Access Journals (Sweden)

    Gary eTse

    2016-05-01

    Full Text Available The gastrointestinal (GI tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field.

  6. In Situ Measurement of Voltage-Induced Stress in Conducting Polymers with Redox-Active Dopants.

    Science.gov (United States)

    Sen, Sujat; Kim, Sung Yeol; Palmore, Lia R; Jin, Shenghua; Jadhav, Nitin; Chason, Eric; Palmore, G Tayhas R

    2016-09-14

    Minimization of stress-induced mechanical rupture and delamination of conducting polymer (CP) films is desirable to prevent failure of devices based on these materials. Thus, precise in situ measurement of voltage-induced stress within these films should provide insight into the cause of these failure mechanisms. The evolution of stress in films of polypyrrole (pPy), doped with indigo carmine (IC), was measured in different electrochemical environments using the multibeam optical stress sensor (MOSS) technique. The stress in these films gradually increases to a constant value during voltage cycling, revealing an initial break-in period for CP films. The nature of the ions involved in charge compensation of pPy[IC] during voltage cycling was determined from electrochemical quartz crystal microbalance (EQCM) data. The magnitude of the voltage-induced stress within pPy[IC] at neutral pH correlated with the radius of the hydrated mobile ion in the order Li(+) > Na(+) > K(+). At acidic pH, the IC dopant in pPy[IC] undergoes reversible oxidation and reduction within the range of potentials investigated, providing a secondary contribution to the observed voltage-induced stress. We report on the novel stress response of these polymers due to the presence of pH-dependent redox-active dopants and how it can affect material performance.

  7. Four-point probe electrical resistivity scanning system for large area conductivity and activation energy mapping.

    Science.gov (United States)

    Shimanovich, Klimentiy; Bouhadana, Yaniv; Keller, David A; Rühle, Sven; Anderson, Assaf Y; Zaban, Arie

    2014-05-01

    The electrical properties of metal oxides play a crucial role in the development of new photovoltaic (PV) systems. Here we demonstrate a general approach for the determination and analysis of these properties in thin films of new metal oxide based PV materials. A high throughput electrical scanning system, which facilitates temperature dependent measurements at different atmospheres for highly resistive samples, was designed and constructed. The instrument is capable of determining conductivity and activation energy values for relatively large sample areas, of about 72 × 72 mm(2), with the implementation of geometrical correction factors. The efficiency of our scanning system was tested using two different samples of CuO and commercially available Fluorine doped tin oxide coated glass substrates. Our high throughput tool was able to identify the electrical properties of both resistive metal oxide thin film samples with high precision and accuracy. The scanning system enabled us to gain insight into transport mechanisms with novel compositions and to use those insights to make smart choices when choosing materials for our multilayer thin film all oxide photovoltaic cells.

  8. Small-conductance Ca2+ -activated K+ channels and cardiac arrhythmias.

    Science.gov (United States)

    Zhang, Xiao-Dong; Lieu, Deborah K; Chiamvimonvat, Nipavan

    2015-08-01

    Small-conductance Ca2+ -activated K+ (SK, KCa2) channels are unique in that they are gated solely by changes in intracellular Ca2+ and, hence, function to integrate intracellular Ca2+ and membrane potentials on a beat-to-beat basis. Recent studies have provided evidence for the existence and functional significance of SK channels in the heart. Indeed, our knowledge of cardiac SK channels has been greatly expanded over the past decade. Interests in cardiac SK channels are further driven by recent studies suggesting the critical roles of SK channels in human atrial fibrillation, the SK channel as a possible novel therapeutic target in atrial arrhythmias, and upregulation of SK channels in heart failure in animal models and in human heart failure. However, there remain critical gaps in our knowledge. Specifically, blockade of SK channels in cardiac arrhythmias has been shown to be both antiarrhythmic and proarrhythmic. This contemporary review provides an overview of the literature on the role of cardiac SK channels in cardiac arrhythmias and serves as a discussion platform for the current clinical perspectives. At the translational level, development of SK channel blockers as a new therapeutic strategy in the treatment of atrial fibrillation and the possible proarrhythmic effects merit further considerations and investigations.

  9. Trace Elements in the Conductive Tissue of Beef Heart Determined by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wester, P.O.

    1965-08-15

    By means of neutron activation analysis, samples of four beef hearts taken from the bundle of His and adjacent ventricular muscle, the AV node and adjacent atrial muscle are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent {gamma}-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, .Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, W and Zn. In the conductive tissue compared to adjacent muscle tissue, calculations on a wet weight basis show a lower concentration of Cs, Cu, Fe, K, P, Rb and Zn in the former, and a higher concentration of Ag, Au, Br, Ca and Na. The mean differences ({mu}g/g wet tissue), as well as their degree of significance, between the bundle of His and adjacent tissue from the ventricular septum, between the AV node and adjacent atrial muscle, between the ventricular septum and the right atrium, and between the bundle of His and the AV node are given for the elements Cu, Fe, K, Na, P and Zn.

  10. Resting state brain activity and functional brain mapping

    Institute of Scientific and Technical Information of China (English)

    Zhao Xiaohu; Wang Peijun; Tang Xiaowei

    2007-01-01

    Functional brain imaging studies commonly use either resting or passive task states as their control conditions, and typically identify the activation brain region associated with a specific task by subtracting the resting from the active task conditions. Numerous studies now suggest, however, that the resting state may not reflect true mental "rest" conditions. The mental activity that occurs during"rest" might therefore greatly influence the functional neuroimaging observations that are collected through the usual subtracting analysis strategies. Exploring the ongoing mental processes that occur during resting conditions is thus of particular importance for deciphering functional brain mapping results and obtaining a more comprehensive understanding of human brain functions. In this review article, we will mainly focus on the discussion of the current research background of functional brain mapping at resting state and the physiological significance of the available neuroimaging data.

  11. Spatial variability of soil electrical conductivity under the mole rats (Spalax microphthalmus digging activity at the different scales

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2012-07-01

    Full Text Available The soil mounds emerged owing to the mole rats’ digging activity have been shown to be characterised by less electrical conductivity than surrounded soil. This effect is due to the changes of the mounds bulk’s density and moisture. The effect of the mole rats’ digging activity on the soil electrical conductivity has been found not to be restricted by the geometrical border of the mounds. The mounds are surrounded by 1–1.5 m halo of increased soil electrical conductivity. The halo size is increased with the aging of the mound and with the compacting of their aggregation.

  12. Development of Lithium Stuffed Garnet-Type Oxide Solid Electrolytes with High Ionic Conductivity for Application to All-Solid-State Batteries

    Directory of Open Access Journals (Sweden)

    Ryoji Inada

    2016-07-01

    Full Text Available All-solid-state lithium-ion battery (LiB is expected as one of the next generation energy storage devices because of their high energy density, high safety and excellent cycle stability. Although oxide-based solid electrolyte materials have rather lower conductivity and poor deformability than sulfide-based one, they have other advantages such as their chemical stability and easiness for handling. Among the various oxide-based SEs, lithium stuffed garnet-type oxide with the formula of Li7La3Zr2O12 (LLZ have been widely studied because of their high conductivity above 10-4 Scm-1 at room temperature, excellent thermal performance and stability against Li metal anode.Here, we present our recent progress for the development of garnet-type solid electrolytes with high conductivity by simultaneous substitution of Ta5+ into Zr4+ site and Ba2+ into La3+ site in LLZ. Li+ concentration was fixed to 6.5 per chemical formulae, so that the formulae of our Li garnet-type oxide is expressed as Li6.5La3-xBaxZr1.5-xTa0.5+xO12 (LLBZT and Ba contents x are changed from 0 to 0.3. As results, all LLBZT samples have cubic garnet structure without containing any secondary phases. The lattice parameters of LLBZT decrease with increasing Ba2+ contents x < 0.10 while increase with x from 0.10 to 0.30, possibly due to the simultaneous change of Ba2+ and Ta5+ substitution levels. Relative densities of LLBZT are in the range between 89% and 93% and not influenced so much by the compositions. From AC impedance spectroscopy measurements, the total (bulk + grain conductivity at 27ºC of LLBZT shows its maximum value of 8.34 x 10-4 S cm-1 at x = 0.10, which is slightly higher than the conductivity (= 7.94 x 10-4 S cm-1 of LLZT without substituting Ba (x = 0. Activation energy of the conductivity tends to become lower by Ba substation, while excess Ba substitution degrades the conductivity in LLBZT. LLBZT has wide electrochemical potential window of 0-6 V vs. Li+/Li and

  13. Mitochondrial functional state impacts spontaneous neocortical activity and resting state FMRI.

    Directory of Open Access Journals (Sweden)

    Basavaraju G Sanganahalli

    Full Text Available Mitochondrial Ca(2+ uptake, central to neural metabolism and function, is diminished in aging whereas enhanced after acute/sub-acute traumatic brain injury. To develop relevant translational models for these neuropathologies, we determined the impact of perturbed mitochondrial Ca(2+ uptake capacities on intrinsic brain activity using clinically relevant markers. From a multi-compartment estimate of probable baseline Ca(2+ ranges in the brain, we hypothesized that reduced or enhanced mitochondrial Ca(2+ uptake capacity would decrease or increase spontaneous neuronal activity respectively. As resting state fMRI-BOLD fluctuations and stimulus-evoked BOLD responses have similar physiological origins [1] and stimulus-evoked neuronal and hemodynamic responses are modulated by mitochondrial Ca(2+ uptake capacity [2], [3] respectively, we tested our hypothesis by measuring hemodynamic fluctuations and spontaneous neuronal activities during normal and altered mitochondrial functional states. Mitochondrial Ca(2+ uptake capacity was perturbed by pharmacologically inhibiting or enhancing the mitochondrial Ca(2+ uniporter (mCU activity. Neuronal electrical activity and cerebral blood flow (CBF fluctuations were measured simultaneously and integrated with fMRI-BOLD fluctuations at 11.7T. mCU inhibition reduced spontaneous neuronal activity and the resting state functional connectivity (RSFC, whereas mCU enhancement increased spontaneous neuronal activity but reduced RSFC. We conclude that increased or decreased mitochondrial Ca(2+ uptake capacities lead to diminished resting state modes of brain functional connectivity.

  14. Universal Heat Conduction in the Iron Arsenide Superconductor KFe2As2: Evidence of a d-Wave State

    Energy Technology Data Exchange (ETDEWEB)

    Reid, J.-Ph.; Tanatar, Makariy A.; Juneau-Fecteau, A.; Gordon, R.T.; Rene de Cotret, S.; Doiron-Leyraud, N.; Saito, T.; Fukazawa, H.; Kohori, Y.; Kihou, K.; Lee, C.H.; Iyo, A.; Eisaki, H.; Prozorov, Ruslan; Taillefer, Louis

    2012-08-21

    The thermal conductivity κ of the iron arsenide superconductor KFe2As2 was measured down to 50 mK for a heat current parallel and perpendicular to the tetragonal c axis. A residual linear term at T→0, κ0/T is observed for both current directions, confirming the presence of nodes in the superconducting gap. Our value of κ0/T in the plane is equal to that reported by Dong et al. [ Phys. Rev. Lett. 104 087005 (2010)] for a sample whose residual resistivity ρ0 was 10 times larger. This independence of κ0/T on impurity scattering is the signature of universal heat transport, a property of superconducting states with symmetry-imposed line nodes. This argues against an s-wave state with accidental nodes. It favors instead a d-wave state, an assignment consistent with five additional properties: the magnitude of the critical scattering rate Γc for suppressing Tc to zero; the magnitude of κ0/T, and its dependence on current direction and on magnetic field; the temperature dependence of κ(T).

  15. Universal heat conduction in the iron arsenide superconductor KFe2As2: evidence of a d-wave state.

    Science.gov (United States)

    Reid, J-Ph; Tanatar, M A; Juneau-Fecteau, A; Gordon, R T; de Cotret, S René; Doiron-Leyraud, N; Saito, T; Fukazawa, H; Kohori, Y; Kihou, K; Lee, C H; Iyo, A; Eisaki, H; Prozorov, R; Taillefer, Louis

    2012-08-24

    The thermal conductivity κ of the iron arsenide superconductor KFe2As2 was measured down to 50 mK for a heat current parallel and perpendicular to the tetragonal c axis. A residual linear term at T→0, κ(0)/T is observed for both current directions, confirming the presence of nodes in the superconducting gap. Our value of κ(0)/T in the plane is equal to that reported by Dong et al. [Phys. Rev. Lett. 104, 087005 (2010)] for a sample whose residual resistivity ρ(0) was 10 times larger. This independence of κ(0)/T on impurity scattering is the signature of universal heat transport, a property of superconducting states with symmetry-imposed line nodes. This argues against an s-wave state with accidental nodes. It favors instead a d-wave state, an assignment consistent with five additional properties: the magnitude of the critical scattering rate Γ(c) for suppressing T(c) to zero; the magnitude of κ(0)/T, and its dependence on current direction and on magnetic field; the temperature dependence of κ(T).

  16. The State of Anxiety Felt by Elementary School Pupils during Foreign Language Activities

    OpenAIRE

    松宮, 奈賀子

    2010-01-01

    This paper aims to investigate the state of anxiety felt by elementary school pupils while they are in foreign language activities classes. "Foreign language anxiety" is considered to have negative effects to the learners' learning and thus should be taken away. However, the foreign language anxiety has been believed to relate basically to the adult learners and few studies have been conducted which deals young learners' anxiety on foreign language learning. In this paper, about 1,500 element...

  17. Activation of silicon quantum dots and coupling between the active centre and the defect state of the photonic crystal in a nanolaser

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Chen Hang-Qiong; Shu Qin; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    A new nanolaser concept using silicon quantum dots (QDs) is proposed.The conduction band opened by the quantum confinement effect gives the pumping levels.Localized states in the gap due to some surface bonds on Si QDs can be formed for the activation of emission.An inversion of population can be generated between the localized states and the valence band in a QD fabricated by using a nanosecond pulse laser.Coupling between the active centres formed by localized states and the defect states of the two-dimensional (2D) photonic crystal can be used to select the model in the nanolaser.

  18. Bone conducted vibration activates the vestibulo-ocular reflex in the guinea pig.

    Science.gov (United States)

    Vulovic, Vedran; Curthoys, Ian S

    2011-08-10

    The aim of the study was: (a) to test whether short duration (6 ms) 500 Hz bone-conducted vibration (BCV) of the skull in alert head free guinea pigs would elicit eye movements; (b) to test whether these eye movements were vestibular in origin; and (c) to determine whether they corresponded to human eye movements to such stimuli. In this way we sought to establish the guinea pig as an acceptable model for testing the mechanism of the effect BCV on the vestibulo-ocular reflex. Consistent short-latency stimulus-locked responses to BCV were observed. The magnitude of eye displacement was directly related to stimulus intensity as recorded by accelerometers cemented onto the animal's skull. The strongest and most consistent response component was intorsion of both eyes. In lateral-eyed animals intorsion is produced by the combined contraction of the inferior rectus and superior oblique muscles. In humans the same pair of muscles acts to cause depression of the eye. To test whether the movements were vestibular we selectively ablated the vestibular endorgans: 3 of the 8 animals underwent a bilateral intratympanic injection of gentamicin, an ototoxic aminoglycoside antibiotic, to ablate their vestibular receptors. After ablation there was an overall reduction in the magnitude of eye displacement, as well as a reduction in the effectiveness of the BCV stimulus to elicit eye movements. The animals' hearing, as measured by the threshold for auditory brainstem responses, remained unchanged after gentamicin, confirming that the cochlea was not affected. The reduced magnitude of responses after vestibular receptor ablation demonstrates that the eye-movement responses to BCV are probably caused by the stimulation of vestibular receptors, which in turn activate the vestibulo-ocular reflex.

  19. Oscillations and multiple steady states in active membrane transport models.

    Science.gov (United States)

    Vieira, F M; Bisch, P M

    1994-01-01

    The dynamic behavior of some non-linear extensions of the six-state alternating access model for active membrane transport is investigated. We use stoichio-metric network analysis to study the stability of steady states. The bifurcation analysis has been done through standard numerical methods. For the usual six-state model we have proved that there is only one steady state, which is globally asymptotically stable. When we added an autocatalytic step we found self-oscillations. For the competition between a monomer cycle and a dimer cycle, with steps of dimer formation, we have also found self-oscillations. We have also studied models involving the formation of a complex with other molecules. The addition of two steps for formation of a complex of the monomer with another molecule does not alter either the number or the stability of steady states of the basic six-state model. The model which combines the formation of a complex with an autocatalytic step shows both self-oscillations and multiple steady states. The results lead us to conclude that oscillations could be produced by active membrane transport systems if the transport cycle contains a sufficiently large number of steps (six in the present case) and is coupled to at least one autocatalytic reaction,. Oscillations are also predicted when the monomer cycle is coupled to a dimer cycle. In fact, the autocatalytic reaction can be seen as a simplification of the model involving competition between monomer and dimer cycles, which seems to be a more realistic description of biological systems. A self-regulation mechanism of the pumps, related to the multiple stationary states, is expected only for a combined effect of autocatalysis and formation of complexes with other molecules. Within the six-state model this model also leads to oscillation.

  20. Monoaminergic tone supports conductance correlations and stabilizes activity features in pattern generating neurons of the lobster, Panulirus interruptus

    Directory of Open Access Journals (Sweden)

    Wulf-Dieter C. Krenz

    2015-10-01

    Full Text Available Experimental and computational studies demonstrate that different sets of intrinsic and synaptic conductances can give rise to equivalent activity patterns. This is because the balance of conductances, not their absolute values, defines a given activity feature. Activity-dependent feedback mechanisms maintain neuronal conductance correlations and their corresponding activity features. This study demonstrates that tonic nM concentrations of monoamines enable slow, activity-dependent processes that can maintain a correlation between the transient potassium current (IA and the hyperpolarization activated current (Ih over the long-term (i.e., regulatory change persists for hours after removal of modulator. Tonic 5nM DA acted through an RNA interference silencing complex (RISC- and RNA polymerase II-dependent mechanism to maintain a long-term positive correlation between IA and Ih in the lateral pyloric neuron (LP but not in the pyloric dilator neuron (PD. In contrast, tonic 5nM 5HT maintained a RISC-dependent positive correlation between IA and Ih in PD but not LP over the long-term. Tonic 5nM OCT maintained a long-term negative correlation between IA and Ih in PD but not LP; however, it was only revealed when RISC was inhibited. This study also demonstrated that monoaminergic tone can also preserve activity features over the long-term: The timing of LP activity, LP duty cycle and LP spike number per burst were maintained by tonic 5nM DA. The data suggest that low-level monoaminergic tone acts through multiple slow processes to permit cell-specific, activity-dependent regulation of ionic conductances to maintain conductance correlations and their corresponding activity features over the long-term.

  1. INVESTMENT ACTIVITY OF NON-STATE FOUNDS OF RUSSIA

    Directory of Open Access Journals (Sweden)

    Kobylinsky S. V.

    2016-04-01

    Full Text Available Currently, pension by virtue of their social significance in favor of one of the main socially important guarantee of stable development of society, to ensure the financial and budgetary sphere of the state. Private pension founds are viewed as an instrument to raise the material well-being of pensioners. The social significance of non-state pension funds is to involve the population in the sphere of voluntary pension insurance. The author analyzed the role of non-state pension funds in acting to pension system. The article subjected to a detailed analysis of the norms of a number of Federal laws, fixing the investment activity of non-state pension found. The author concludes that there is a need to improve existing legislation on investment activity of non-state pension found. As well, the authors indicated some legal problems that occur in practice arising from owners of the investment portfolio. The authors have analyzed the performance of pension funds and formed an opinion about the state of the whole system. Following consideration of the practical problems has been offered for both theoretical and practical ways to address them in order to prevent violation

  2. The Current State of Marketing Activity among Higher Education Institutions.

    Science.gov (United States)

    Newman, Cynthia M.

    2002-01-01

    Investigated the current state of marketing, marketing research, and planning practices at four-year higher education institutions. Builds upon previous studies by Blackburn (1979) and Goldgehn (1982 and 1989). Determined whether the use and apparent understanding of marketing and its attendant activities by admissions and enrollment management…

  3. Resting-state beta and gamma activity in Internet addiction.

    Science.gov (United States)

    Choi, Jung-Seok; Park, Su Mi; Lee, Jaewon; Hwang, Jae Yeon; Jung, Hee Yeon; Choi, Sam-Wook; Kim, Dai Jin; Oh, Sohee; Lee, Jun-Young

    2013-09-01

    Internet addiction is the inability to control one's use of the Internet and is related to impulsivity. Although a few studies have examined neurophysiological activity as individuals with Internet addiction engage in cognitive processing, no information on spontaneous EEG activity in the eyes-closed resting-state is available. We investigated resting-state EEG activities in beta and gamma bands and examined their relationships with impulsivity among individuals with Internet addiction and healthy controls. Twenty-one drug-naïve patients with Internet addiction (age: 23.33 ± 3.50 years) and 20 age-, sex-, and IQ-matched healthy controls (age: 22.40 ± 2.33 years) were enrolled in this study. Severity of Internet addiction was identified by the total score on Young's Internet Addiction Test. Impulsivity was measured with the Barratt Impulsiveness Scale-11 and a stop-signal task. Resting-state EEG during eyes closed was recorded, and the absolute/relative power of beta and gamma bands was analyzed. The Internet addiction group showed high impulsivity and impaired inhibitory control. The generalized estimating equation showed that the Internet-addiction group showed lower absolute power on the beta band than did the control group (estimate = -3.370, p Internet addiction as well as with the extent of impulsivity. The present study suggests that resting-state fast-wave brain activity is related to the impulsivity characterizing Internet addiction. These differences may be neurobiological markers for the pathophysiology of Internet addiction.

  4. Steady-state organization of binary mixtures by active impurities

    DEFF Research Database (Denmark)

    Sabra, Mads Christian; Gilhøj, Henriette; Mouritsen, Ole G.

    1998-01-01

    The structural reorganization of a phase-separated binary mixture in the presence of an annealed dilution of active impurities is studied by computer-simulation techniques via a simple two-dimensional lattice-gas model. The impurities, each of which has two internal states with different affinity...

  5. THE EUROPEAN MODEL OF STATE REGULATION OF TOURISM ACTIVITIES

    Directory of Open Access Journals (Sweden)

    О. Davydova

    2013-11-01

    Full Text Available In the article the existing model of state regulation of the development of tourism. Expediency of the European model of state regulation of tourism development in Ukraine. It is noted that the European model of state regulation of tourism activities based on the coordination of marketing activities and the development of cooperation between the public and private sectors. The basic forms of public-private partnerships and the advantages of using cluster model of development of tourism, namely, contracts, production sharing agreement, lease, joint venture. Promising areas of application of the PPP identified the transport sector, housing and utilities, energy and tourism sector. The features of cluster formations in the country and the prospects for tourism clusters.

  6. Multiwall Carbon Nanotube Coated with Conducting Polyaniline Nanocomposites for Quasi-Solid-State Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2013-01-01

    Full Text Available Multiwalled carbon nanotube (MWNT coated with conducting polyaniline (PAni nanocomposites has been enforced as for quasi-solid-state electrolyte layer in the dye-sensitized solar cells (DSSCs, and the incorporation of MWNT-PAni nanoparticles on the cell performance has been examined. The MWNT-PAni nanoparticles exploited as the extended electron transfer materials, which can reduce charge diffusion length and serve simultaneously as catalyst for the electrochemical reduction of I3-. An ionic liquid of 1-methyl-3-propyl-imidazolium iodide (PMII together with the hybrid MWNT-PAni nanocomposites was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and achieved a moderately higher cell efficiency (3.15%, as compared to that containing bare PMII (0.26%.

  7. Novel Solid-State Solar Cell Based on Hole-Conducting MOF-Sensitizer Demonstrating Power Conversion Efficiency of 2.1.

    Science.gov (United States)

    Ahn, Do Young; Lee, Deok Yeon; Shin, Chan Yong; Bui, Hoa Thi; Shrestha, Nabeen K; Giebeler, Lars; Noh, Yong-Young; Han, Sung-Hwan

    2017-04-05

    This work reports on designing of first successful MOF-sensitizer based solid-state photovoltaic device, perticularly with a meaningful output power conversion efficiency. In this study, an intrinsically conductive cobalt-based MOFs (Co-DAPV) formed by the coordination between Co (II) ions and a redox active di(3-diaminopropyl)-viologen (i.e., DAPV) ligand is investigated as sensitizer. Hall-effect measurement shows p-type conductivity of the Co-DAPV film with hole mobility of 0.017 cm(2) V(-1) s(-1), suggesting its potential application as hole transporting sensitizer. Further, the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of Co-DAPV are well-matched to be suitably employed for sensitizing TiO2. Thus, by layer-by-layer deposition of hole conducting MOF-sensitizer onto mesoporous TiO2 film, a power conversion efficiency of as high as 2.1% is achieved, which exceeds the highest efficiency values of MOF-sensitized liquid-junction solar cells reported so far.

  8. Synthesis, spectroscopic characterization, solid state d.c. electrical conductivity and biological studies of some lanthanide(III chloride complexes with a heterocyclic Schiff base ligand

    Directory of Open Access Journals (Sweden)

    K. Mohanan

    2016-07-01

    Full Text Available Condensation of 2-hydroxy-1-naphthaldehyde with 2-amino-3-carboxyethyl-4,5-dimethylthiophene in 1:1 molar ratio, yielded a potentially tridentate Schiff base viz. 2-[N-(2′-hydroxy-1-naphthylideneamino]-3-carboxyethyl-4,5-dimethylthiophene (HNAT. This ligand formed complexes with lanthanum(III, cerium(III, praseodymium(III, neodymium(III, samarium(III, europium(III and gadolinium(III chloride under well defined conditions. These complexes were characterized through elemental analysis, molar conductance, magnetic moment measurements, IR, UV–Vis, FAB mass and 1H NMR spectral studies. Analytical data showed that all the metal complexes exhibited 1:1 metal–ligand ratio. Molar conductance values adequately confirmed the non-electrolytic nature of the metal complexes. The proton NMR spectral observations supplement the IR spectral assignments. The spectral data revealed that the ligand acted as neutral tridentate, coordinating to the metal ion through azomethine nitrogen, ester carbonyl and naphtholate oxygen without deprotonation. The ligand and its lanthanum(III chloride complex were subjected to XRD studies. The lanthanum(III chloride complex has undergone a facile transesterification reaction. The solid state d.c. electrical conductivity of some selected complexes were measured as a function of temperature, indicating the semiconducting nature of the metal complexes. The antimicrobial activities were examined by disk diffusion method against some pathogenic bacterial and fungal species.

  9. 77 FR 19231 - Takes of Marine Mammals Incidental to Specified Activities; Navy Training Conducted at the Silver...

    Science.gov (United States)

    2012-03-30

    ..., three long- beaked common dolphins were found dead following the Navy's mine neutralization training... detonations are only conducted in sea-states equal to or less than Beaufort 3 (presence of large wavelets... conditions (Carretta et al. 2010). Common dolphin distributions may be related to bathymetry (Hui 1979)....

  10. Anisotropy of conductivity in rare-earth tritellurides in the static and sliding states of the CDW

    Energy Technology Data Exchange (ETDEWEB)

    Sinchenko, A., E-mail: aasinch@mail.ru [Univ. Grenoble Alpes, Inst. Neel, F-38042 Grenoble (France); CNRS, Inst. Neel, F-38042 Grenoble (France); Kotel' nikov Institute of Radioengineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow (Russian Federation); National Research Nuclear University (MEPhI), 115409 Moscow (Russian Federation); Grigoriev, P.D. [L.D. Landau Institute for Theoretical Physics, 142432 Chernogolovka (Russian Federation); Lejay, P.; Leynaud, O.; Monceau, P. [Univ. Grenoble Alpes, Inst. Neel, F-38042 Grenoble (France); CNRS, Inst. Neel, F-38042 Grenoble (France)

    2015-03-01

    We show that the isotropic conductivity in the normal state of rare-earth tritelluride RTe{sub 3} compounds is broken by the occurrence of the unidirectional charge density wave (CDW) in the (a,c) plane below the Peierls transition temperature. In contrast with quasi-one-dimensional systems, the resistivity anomaly associated with the CDW transition is strong in the direction perpendicular to the CDW wave vector Q (a-axis) and very weak in the CDW wave vector Q direction (c-axis). We qualitatively explain this result by calculating the electrical conductivity for the electron dispersion with momentum-dependent CDW gap as determined by angle-resolved photoemission spectroscopy (ARPES). Nonlinear transport properties in TbTe{sub 3} and GdTe{sub 3} have been studied along different crystallographic orientations. The pronounced effect of collective CDW motion is observed along c-axis and is absent completely in the perpendicular direction demonstrating the unidirectional character of the CDW. The threshold electric field for CDW sliding is linearly temperature dependent in a wide range of temperature.

  11. Chiral magnetic conductivity and surface states of Weyl semimetals in topological insulator ultra-thin film multilayer

    Science.gov (United States)

    Owerre, S. A.

    2016-06-01

    We investigate an ultra-thin film of topological insulator (TI) multilayer as a model for a three-dimensional (3D) Weyl semimetal. We introduce tunneling parameters t S, {{t}\\bot} , and t D, where the former two parameters couple layers of the same thin film at small and large momenta, and the latter parameter couples neighbouring thin film layers along the z-direction. The Chern number is computed in each topological phase of the system and we find that for {{t}\\text{S}},{{t}\\text{D}}>0 , the tunneling parameter {{t}\\bot} changes from positive to negative as the system transits from Weyl semi-metallic phase to insulating phases. We further study the chiral magnetic effect (CME) of the system in the presence of a time dependent magnetic field. We compute the low-temperature dependence of the chiral magnetic conductivity and show that it captures three distinct phases of the system separated by plateaus. Furthermore, we propose and study a 3D lattice model of Porphyrin thin film, an organic material known to support topological Frenkel exciton edge states. We show that this model exhibits a 3D Weyl semi-metallic phase and also supports a 2D Weyl semi-metallic phase. We further show that this model recovers that of 3D Weyl semimetal in topological insulator thin film multilayer. Thus, paving the way for simulating a 3D Weyl semimetal in topological insulator thin film multilayer. We obtain the surface states (Fermi arcs) in the 3D model and the chiral edge states in the 2D model and analyze their topological properties.

  12. Chiral magnetic conductivity and surface states of Weyl semimetals in topological insulator ultra-thin film multilayer.

    Science.gov (United States)

    Owerre, S A

    2016-06-15

    We investigate an ultra-thin film of topological insulator (TI) multilayer as a model for a three-dimensional (3D) Weyl semimetal. We introduce tunneling parameters t S, [Formula: see text], and t D, where the former two parameters couple layers of the same thin film at small and large momenta, and the latter parameter couples neighbouring thin film layers along the z-direction. The Chern number is computed in each topological phase of the system and we find that for [Formula: see text], the tunneling parameter [Formula: see text] changes from positive to negative as the system transits from Weyl semi-metallic phase to insulating phases. We further study the chiral magnetic effect (CME) of the system in the presence of a time dependent magnetic field. We compute the low-temperature dependence of the chiral magnetic conductivity and show that it captures three distinct phases of the system separated by plateaus. Furthermore, we propose and study a 3D lattice model of Porphyrin thin film, an organic material known to support topological Frenkel exciton edge states. We show that this model exhibits a 3D Weyl semi-metallic phase and also supports a 2D Weyl semi-metallic phase. We further show that this model recovers that of 3D Weyl semimetal in topological insulator thin film multilayer. Thus, paving the way for simulating a 3D Weyl semimetal in topological insulator thin film multilayer. We obtain the surface states (Fermi arcs) in the 3D model and the chiral edge states in the 2D model and analyze their topological properties.

  13. Low-temperature solid-state microwave reduction of graphene oxide for transparent electrically conductive coatings on flexible polydimethylsiloxane (PDMS).

    Science.gov (United States)

    Liang, Qizhen; Hsie, Sinsar Alec; Wong, Ching Ping

    2012-11-12

    Microwaves (MWs) are applied to initialize deoxygenation of graphene oxide (GO) in the solid state and at low temperatures (∼165 °C). The Fourier-transform infrared (FTIR) spectra of MW-reduced graphene oxide (rGO) show a significantly reduced concentration of oxygen-containing functional groups, such as carboxyl, hydroxyl and carbonyl. X-ray photoelectron spectra confirm that microwaves can promote deoxygenation of GO at relatively low temperatures. Raman spectra and TGA measurements indicate that the defect level of GO significantly decreases during the isothermal solid-state MW-reduction process at low temperatures, corresponding to an efficient recovery of the fine graphene lattice structure. Based on both deoxygenation and defect-level reduction, the resurgence of interconnected graphene-like domains contributes to a low sheet resistance (∼7.9×10(4) Ω per square) of the MW-reduced GO on SiO(2) -coated Si substrates with an optical transparency of 92.7 % at ∼547 nm after MW reduction, indicating the ultrahigh efficiency of MW in GO reduction. Moreover, the low-temperature solid-state MW reduction is also applied in preparing flexible transparent conductive coatings on polydimethylsiloxane (PDMS) substrates. UV/Vis measurements indicate that the transparency of the thus-prepared MW-reduced GO coatings on PDMS substrates ranges from 34 to 96 %. Correspondingly, the sheet resistance of the coating ranges from 10(5) to 10(9) Ω per square, indicating that MW reduction of GO is promising for the convenient low-temperature preparation of transparent conductors on flexible polymeric substrates.

  14. Avalanche mode of high-voltage overloaded p{sup +}–i–n{sup +} diode switching to the conductive state by pulsed illumination

    Energy Technology Data Exchange (ETDEWEB)

    Kyuregyan, A. S., E-mail: ask@vei.ru [Lenin All-Russia Electrical Engineering Institute (Russian Federation)

    2015-07-15

    A simple analytical theory of the picosecond switching of high-voltage overloaded p{sup +}–i–n{sup +} photodiodes to the conductive state by pulsed illumination is presented. The relations between the parameters of structure, light pulse, external circuit, and main process characteristics, i.e., the amplitude of the active load current pulse, delay time, and switching duration, are derived and confirmed by numerical simulation. It is shown that the picosecond light pulse energy required for efficient switching can be decreased by 6–7 orders of magnitude due to the intense avalanche multiplication of electrons and holes. This offers the possibility of using pulsed semiconductor lasers as a control element of optron pairs.

  15. Electroanalysis of NADH Using Conducting and Redox Active Polymer/Carbon Nanotubes Modified Electrodes-A Review

    Directory of Open Access Journals (Sweden)

    Shen-Ming Chen

    2008-01-01

    Full Text Available Past few decades, conducting and redox active polymers play a critical role in the development of transducers for biosensing. It has been evidenced by increasing numerous reports on conducting and redox active polymers incorporated electrodes for assay of biomolcules. This review highlights the potential uses of electrogenerated polymer modified electrodes and polymer/carbon nanotubes composite modified electrodes for electroanalysis of reduced form of nicotinamide adenine dinuceltoide (NADH. In addition, carbon electrodes modified with organic and inorganic materials as modifier have been discussed in detail for the quantification of NADH based on mediator or mediator-less methods.

  16. Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

    DEFF Research Database (Denmark)

    Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

    2015-01-01

    -tuned passive filter and an active filter in series connection, both dc voltage and kVA rating of the active filter are dramatically decreased compared with the pure shunt active filter. In real application, this feature is very attractive since the active power filter with fully power electronics is very...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

  17. Preparation of hydroxide ion conductive KOH–layered double hydroxide electrolytes for an all-solid-state iron–air secondary battery

    Directory of Open Access Journals (Sweden)

    Taku Tsuneishi

    2014-06-01

    Full Text Available Anion conductive solid electrolytes based on Mg–Al layered double hydroxide (LDH were prepared for application in an all-solid-state Fe–air battery. The ionic conductivity and the conducting ion species were evaluated from impedance and electromotive force measurements. The ion conductivity of LDH was markedly enhanced upon addition of KOH. The electromotive force in a water vapor concentration cell was similar to that of an anion-conducting polymer membrane. The KOH–LDH obtained was used as a hydroxide ion conductive electrolyte for all-solid-state Fe–air batteries. The cell performance of the Fe–air batteries was examined using a mixture of KOH–LDH and iron-oxide-supported carbon as the negative electrode.

  18. 75 FR 69295 - Taking and Importing Marine Mammals; Navy Training Activities Conducted Within the Northwest...

    Science.gov (United States)

    2010-11-10

    ... Council (on behalf of the International Fund for Animal Welfare, the Center for Biological Diversity, Cetacean Society International, Friends of the San Juans, the Humane Society of the United States,...

  19. Active states and structure transformations in accreting white dwarfs

    Science.gov (United States)

    Boneva, Daniela; Kaygorodov, Pavel

    2016-07-01

    Active states in white dwarfs are usually associated with light curve's effects that concern to the bursts, flickering or flare-up occurrences. It is common that a gas-dynamics source exists for each of these processes there. We consider the white dwarf binary stars with accretion disc around the primary. We suggest a flow transformation modeling of the mechanisms that are responsible for ability to cause some flow instability and bring the white dwarfs system to the outburst's development. The processes that cause the accretion rate to sufficiently increase are discussed. Then the transition from a quiescent to an active state is realized. We analyze a quasi-periodic variability in the luminosity of white dwarf binary stars systems. The results are supported with an observational data.

  20. Activated conduction by small incision and moderate stimulation for treatment of cerebral palsy in 182 cases

    Institute of Scientific and Technical Information of China (English)

    Wenying Wang; Jianhua Shi; Mingjiang Yu; Dazhi Zhang

    2006-01-01

    BACKGROUND: Internationally, methods to treat cerebral palsy (CP) are basically the same, including correction of deformity with orthopaedic operation, selective posterior rhizotomy(SPR), rehabilitation therapy and so on. Domestic methods to treat CP are basically close to the international methods. Traditional Chinese medical therapies, such as, acupuncture and moxibustion, acupoint injection, massage and so on, also have good curative effects.OBJECTIVE: To observe the effect of activated conduction by small incision and moderate stimulation (ACSIMS) on limb function and living ability in patients with spastic CP at different degrees. DESIGN: Retrospective case analysis.SETTING: Department of Medical Education, Shanxi Medical College for Continuing Education. PARTICIPANTS: A total of 182 patients with CP, including 97 males and 85 females, aged 3 to 23 years, who received treatment in Beijing Haidian District Diaoyutai Hospital during October 1996 to September 2005, were involved in this trial. The involved patients met the diagnostic criteria proposed in 2004 National Special Seminar of Cerebral Palsy. According to typing criteria of CP purposed in 1990 Brioni International Conference, the involved patients were typed: 117 with spastic CP, 14 with involuntary movement CP, 19 with defective coordination CP, 5 with hypotonia CP and 27 with mixed type CP. The guardians of underage patients and adult patients themselves were all informed of the therapeutic regimens. METHODS: ①According to CP typing assessment quantitative criteria of Li, the involved patients were assigned from limb position, daily living and movement 3 aspects: mild 23, moderate 75, severe 62 and extremely severe 22. ② Operation methods: The lower limb of moderate spastic CP patient was taken as an example. A median incision or paramedian incision was made between L2 and S1, and it was also the first incision in lower limb. The secorid incision was made at the center of buttock or at the

  1. 34 CFR 350.32 - What activities must a Rehabilitation Engineering Research Center conduct?

    Science.gov (United States)

    2010-07-01

    ... methods of applying advanced technology, scientific achievement, and psychological and social knowledge to... Research Center conduct? 350.32 Section 350.32 Education Regulations of the Offices of the Department of... DISABILITY AND REHABILITATION RESEARCH PROJECTS AND CENTERS PROGRAM What Rehabilitation Engineering...

  2. Genetically Programming Interfaces between Active Materials, Conductive Pathway and Current Collector in Li Ion Batteries

    Science.gov (United States)

    2012-01-01

    assembled into coin cell with metallic lithium as counter electrode. Electrochemical characterization was conducted by galvanostatically cycling the half...encodes either A1, A2, S7, T7 or H7. These DNAs were then introduced into bacteria cells for amplification. Genetic sequencing performed on the

  3. Assessment of Pozzolanic Activity Using Methods Based on the Measurement of Electrical Conductivity of Suspensions of Portland Cement and Pozzolan

    OpenAIRE

    Sergio Velázquez; JOSÉ M. MONZÓ; María V. Borrachero; Jordi Payá

    2014-01-01

    The use of methods based on measuring electrical conductivity to assess pozzolanic activity has recently been used primarily in aqueous suspensions of pozzolan: calcium hydroxide. However, the use of similar methods in suspensions of cement with pozzolans has not been widely studied. This paper proposes a new method for rapid assessment of the pozzolanic activity of mineral admixtures in aqueous cement suspensions. In this study, the conditions for the application of the method were optimized...

  4. Hypotonicity activates a voltage-dependent membrane conductance in N2a neuroblastoma cells.

    Science.gov (United States)

    Taruno, Akiyuki; Marunaka, Yoshinori

    2017-03-04

    To maintain cellular and bodily homeostasis, cells respond to extracellular stimuli including osmotic stress by activating various ion channels, which have been implicated in many physiological and pathophysiological conditions. However, cellular osmosensory mechanisms remain elusive. Here, we report a novel voltage-dependent current in N2a cells activated by exposure to hypotonic stress. After a hypotonic challenge, N2a cells sequentially develop two distinct currents. The volume-regulated anion channel (VRAC) current emerges first and, after a delay, activation of a previously uncharacterized strongly outwardly rectifying current follows. The latter, delayed current (Id) is insensitive to NPPB, a nonspecific blocker of Cl(-) channels, and intracellular Mg(2+), which inhibits VRAC and swelling-activated TRPM3 and TRPM7 channels. Replacement of extracellular Na(+) with NMDG(+) reduces inward tail currents, suggesting that Id is mediated by cations. Finally, Id shows voltage-dependent activation with slow activation kinetics and half-maximal activation at +76 mV. These pharmacological and biophysical characteristics of Id are distinct from those of known osmotic cell swelling-activated ion channels. In conclusion, our data identify and characterize a novel osmotically-activated, voltage-dependent ion channel in N2a cells.

  5. Antimicrobial activity and cytotoxicity of cotton fabric coated with conducting polymers, polyaniline or polypyrrole, and with deposited silver nanoparticles

    Science.gov (United States)

    Maráková, Nela; Humpolíček, Petr; Kašpárková, Věra; Capáková, Zdenka; Martinková, Lenka; Bober, Patrycja; Trchová, Miroslava; Stejskal, Jaroslav

    2017-02-01

    Cotton fabric was coated with conducting polymers, polyaniline or polypyrrole, in situ during the oxidation of respective monomers. Raman and FTIR spectra proved the complete coating of substrates. Polypyrrole content was 19.3 wt.% and that of polyaniline 6.0 wt.%. Silver nanoparticles were deposited from silver nitrate solutions of various concentrations by exploiting the reduction ability of conducting polymers. The content of silver was up to 11 wt.% on polypyrrole and 4 wt.% on polyaniline. The sheet resistivity of fabrics was determined. The conductivity was reduced after deposition of silver. The chemical cleaning reduced the conductivity by less than one order of magnitude for polypyrrole coating, while for polyaniline the decrease was more pronounced. The good antibacterial activity against S. aureus and E. coli and low cytotoxicity of polypyrrole-coated cotton, both with and without deposited silver nanoparticles

  6. A monomer is the minimum functional unit required for channel and ATPase activity of the cystic fibrosis transmembrane conductance regulator.

    Science.gov (United States)

    Ramjeesingh, M; Li, C; Kogan, I; Wang, Y; Huan, L J; Bear, C E

    2001-09-04

    The cystic fibrosis transmembrane conductance regulator (CFTR) normally functions as a phosphorylation-regulated chloride channel on the apical surface of epithelial cells, and lack of this function is the primary cause for the fatal disease cystic fibrosis (CF). Previous studies showed that purified, reconstituted CFTR can function as a chloride channel and, further, that its intrinsic ATPase activity is required to regulate opening and closing of the channel gate. However, these previous studies did not identify the quaternary structure required to mediate conduction and catalysis. Our present studies show that CFTR molecules may self-associate in CHO and Sf9 membranes, as complexes close to the predicted size of CFTR dimers can be captured by chemical cross-linking reagents and detected using nondissociative PAGE. However, CFTR function does not require a multimeric complex for function as we determined that purified, reconstituted CFTR monomers are sufficient to mediate regulated chloride conduction and ATPase activity.

  7. Identification and characterization of a novel, shorter isoform of the small conductance Ca(2+)-activated K(+) channel SK2

    NARCIS (Netherlands)

    Murthy, Saravana R. K.; Teodorescu, Georgeta; Nijholt, Ingrid M.; Dolga, Amalia; Grissmer, Stephan; Spiess, Joachim; Blank, Thomas

    2008-01-01

    Throughout the CNS, small conductance Ca(2+)-activated potassium (SK) channels modulate firing frequency and neuronal excitability. We have identified a novel, shorter isoform of standard SK2 (SK2-std) in mouse brain which we named SK2-sh. SK2-sh is alternatively spliced at exon 3 and therefore lack

  8. 30 CFR 285.801 - How must I conduct my approved activities to protect marine mammals, threatened and endangered...

    Science.gov (United States)

    2010-07-01

    ... protect marine mammals, threatened and endangered species, and designated critical habitat? 285.801... GAPs § 285.801 How must I conduct my approved activities to protect marine mammals, threatened and... taking of marine mammals until the appropriate authorization has been issued under the Marine...

  9. Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lluscà, M., E-mail: marta.llusca@ub.edu [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain); López-Vidrier, J. [Department of Electronics, Universitat de Barcelona, Barcelona 08028 (Spain); Lauzurica, S.; Sánchez-Aniorte, M.I. [Centro Laser, Universidad Politécnica de Madrid, Madrid 28031 (Spain); Antony, A. [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain); Indian Institute of Technology Bombay, Mumbai 400076 (India); Molpeceres, C. [Centro Laser, Universidad Politécnica de Madrid, Madrid 28031 (Spain); Hernández, S.; Garrido, B. [Department of Electronics, Universitat de Barcelona, Barcelona 08028 (Spain); Bertomeu, J. [Department of Applied Physics and Optics, Universitat de Barcelona, Barcelona 08028 (Spain)

    2015-11-15

    Transparent and conducting ZnO:Er:Yb thin films with visible up-conversion (660-nm emission under 980-nm excitation) were fabricated by RF magnetron sputtering. The as-deposited films were found to be transparent and conducting and the activation of the Er ions in these films to produce up-conversion luminescence was achieved by different post-deposition annealing treatments in air, vacuum or by laser annealing using a Nd:YVO{sub 4} laser. The structural, electrical and optical properties and the up-conversion efficiency of these films were found to be strongly influenced by the annealing method, and a detailed study is reported in this paper. It has been demonstrated that, although the air annealing was the most efficient in terms of up-conversion, laser annealing was the only method capable of activating Er ions while preserving the electrical conductivity of the doped films. It has been shown that a minimum energy was needed in laser annealing to optically activate the rare earth ions in the ZnO host material to produce up-conversion. Up-converting and transparent conducting ZnO:Er:Yb films with an electrical resistivity of 5×10{sup −2} Ω cm and transparency ~80% in the visible wavelength range has been achieved by laser annealing. - Highlights: • Transparent and conducting ZnO:Er:Yb films were grown via magnetron sputtering. • Post-annealing ZnO:Er:Yb is needed to optically activate Er ions. • Visible up-conversion emission at 660 nm is observed under 980 nm excitation. • A transparent and conducting up-converter is achieved by laser annealing.

  10. Analytical Plans Supporting The Sludge Batch 8 Glass Variability Study Being Conducted By Energysolutions And Cua's Vitreous State Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T. B.; Peeler, D. K.

    2012-11-26

    EnergySolutions (ES) and its partner, the Vitreous State Laboratory (VSL) of The Catholic University of America (CUA), are to provide engineering and technical services support to Savannah River Remediation, LLC (SRR) for ongoing operation of the Defense Waste Processing Facility (DWPF) flowsheet as well as for modifications to improve overall plant performance. SRR has requested via a statement of work that ES/VSL conduct a glass variability study (VS) for Sludge Batch 8. SRR issued a technical task request (TTR) asking that the Savannah River National Laboratory (SRNL) provide planning and data reduction support for the ES/VSL effort. This document provides two analytical plans for use by ES/VSL: one plan is to guide the measurement of the chemical composition of the study glasses while the second is to guide the measurement of the durability of the study glasses. The measurements generated by ES/VSL are to be provided to SRNL for data reduction and evaluation. SRNL is to review the results of its evaluation with ES/VSL and SRR. The results will subsequently be incorporated into a joint report with ES/VSL as a deliverable to SRR to support the processing of SB8 at DWPF.

  11. The effect of dimerization strength and comb-like bond’s hopping energy on electronic conductance and density of states of typical polyacetylene polymers

    Directory of Open Access Journals (Sweden)

    A Esmaeili

    2012-03-01

    Full Text Available  In this paper, we study the electronic conductance and density of states for a comb-like polymer with periodic hopping energies in the tight-binding approach. Electron transmission coefficient and density of states are analytically calculated by using Green’s function of the system. The results show that the electronic conductance spectrum has one energy gap in the absence of carbon-hydrogen bond’s hopping energy, which is proportional to the dimerization strength. Carbon-Hydrogen bond’s hopping energy makes the appearance three energy gaps in the conductance spectrum and the dimerization strength influences only the outer gaps.

  12. A summary of lessons learned activities conducted at the OECD Halden Reactor Project

    Energy Technology Data Exchange (ETDEWEB)

    Hallbert, B.P. [OECD Halden Reactor Project (Norway)

    1997-02-01

    A series of lessons learned studies have been conducted at the OECD Halden Reactor Project. The purpose of these lessons learned reports are to summarize knowledge and experience gained across a number of research project. This paper presents a summary of main issues addressed in four of these lessons learned projects. These are concerned with software development and quality assurance, software reliability, methods for test and evaluation of developed systems, and the evaluation of system design features.

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

    DEFF Research Database (Denmark)

    Grigonis, Ramunas; Guzulaitis, Robertas; Buisas, Rokas

    2016-01-01

    During functional spinal neural network activity motoneurons receive massive synaptic excitation and inhibition, and their membrane conductance increases considerably – they are switched to a high-conductance state. High-conductance states can substantially alter response properties of motoneurons...

  14. The small molecule NS11021 is a potent and specific activator of Ca2+-activated big-conductance K+ channels

    DEFF Research Database (Denmark)

    Bentzen, Bo Hjorth; Nardi, Antonio; Calloe, Kirstine

    2007-01-01

    -channel analysis revealed that NS11021 increased the open probability of the channel by altering gating kinetics without affecting the single-channel conductance. NS11021 (10 microM) influenced neither a number of cloned Kv channels nor endogenous Na(+) and Ca(2+) channels (L- and T-type) in guinea pig cardiac...

  15. Activation of high and low affinity dopamine receptors generates a closed loop that maintains a conductance ratio and its activity correlate

    Directory of Open Access Journals (Sweden)

    Wulf-Dieter Christian Krenz

    2013-10-01

    Full Text Available Neuromodulators alter network output and have the potential to destabilize a circuit. The mechanisms maintaining stability in the face of neuromodulation are not well described. Using the pyloric network in the crustacean stomatogastric nervous system, we show that dopamine (DA does not simply alter circuit output, but activates a closed loop in which DA-induced alterations in circuit output consequently drive a change in an ionic conductance to preserve a conductance ratio and its activity correlate. DA acted at low affinity type 1 receptors (D1Rs to induce an immediate modulatory decrease in the transient potassium current (IA of a pyloric neuron. This, in turn, advanced the activity phase of that component neuron, which disrupted its network function and thereby destabilized the circuit. DA simultaneously acted at high affinity D1Rs on the same neuron to confer activity-dependence upon the hyperpolarization activated current (Ih such that the DA-induced changes in activity subsequently reduced Ih. This DA-enabled, activity-dependent, intrinsic plasticity exactly compensated for the modulatory decrease in IA to restore the IA:Ih ratio and neuronal activity phase, thereby closing an open loop created by the modulator. Activation of closed loops to preserve conductance ratios may represent a fundamental operating principle neuromodulatory systems use to ensure stability in their target networks.

  16. High power density aqueous hybrid supercapacitor combining activated carbon and highly conductive spinel cobalt oxide

    Science.gov (United States)

    Godillot, G.; Taberna, P.-L.; Daffos, B.; Simon, P.; Delmas, C.; Guerlou-Demourgues, L.

    2016-11-01

    The remarkable electrochemical behavior of complete activated carbon/cobalt oxide cells is reported in the present work. Among the various weight ratios between the positive and negative electrodes evaluated, the best features are obtained with an overcapacitive cobalt oxide electrode. The energy densities obtained by this system (20 Wh kg-1 for a power density of 209 W kg-1) are twice higher than those measured for a activated carbon/activated carbon symmetric cell, in the same operating conditions. With discharge capacities around 62 F g-1, this system is among the best ones reported in the literature for this category.

  17. Toward ambient temperature operation with all-solid-state lithium metal batteries with a sp3 boron-based solid single ion conducting polymer electrolyte

    Science.gov (United States)

    Zhang, Yunfeng; Cai, Weiwei; Rohan, Rupesh; Pan, Meize; Liu, Yuan; Liu, Xupo; Li, Cuicui; Sun, Yubao; Cheng, Hansong

    2016-02-01

    The ionic conductivity decay problem of poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) when increase the lithium salt of the SPEs up to high concentration is here functionally overcome by the incorporation of a charge delocalized sp3 boron based single ion conducting polymer electrolyte (SIPE) with poly(ethylene oxide) to fabricate solid-state sp3 boron based SIPE membranes (S-BSMs). By characterizations, particularly differential scanning calorimeter (DSC) and ionic conductivity studies, the fabricated S-BSMs showed decreased melting points and increased ionic conductivity as steadily increase the content of sp3 boron based SIPE, which significantly improved the low temperature performance of the all-solid-state lithium batteries. The fabricated Li | S-BSMs | LiFePO4 cells exhibit highly electrochemical stability and excellent cycling at temperature below melting point of PEO, which has never been reported so far for SIPEs based all-solid-state lithium batteries.

  18. Hydraulic conductivity of active layer soils in the McMurdo Dry Valleys, Antarctica: Geological legacy controls modern hillslope connectivity

    Science.gov (United States)

    Schmidt, Logan M.; Levy, Joseph S.

    2017-04-01

    Spatial variability in the hydraulic and physical properties of active layer soils influences shallow groundwater flow through cold-desert hydrological systems. This study measures the saturated hydraulic conductivity and grain-size distribution of 90 soil samples from the McMurdo Dry Valleys (MDV), Antarctica-primarily from Taylor Valley-to determine what processes affect the spatial distribution of saturated hydraulic conductivity in a simple, mineral-soil-dominated natural hillslope laboratory. We find that the saturated hydraulic conductivity and the grain-size distribution of soils are organized longitudinally within Taylor Valley. Soils sampled down-valley near the coast have a higher percentage of fine-sized sediments (fine sand, silt, clay) and lower saturated hydraulic conductivities than soils collected up-valley near Taylor Glacier (1.3 × 10- 2 vs. 1.2 × 10- 1 cm/s). Soils collected mid-valley have intermediate amounts of fines and saturated hydraulic conductivity values consistent with a hydrogeologic gradient spanning the valley from high inland to low near the coast. These results suggest the organization of modern soil properties within Taylor Valley is a relict signature from past glaciations that have deposited soils of decreasing age toward the mouth of the valley, modified by fluvial activity acting along temporal and microclimate gradients.

  19. Two-dimensional universal conductance fluctuations and the electron-phonon interaction of surface states in Bi2Te2Se microflakes.

    Science.gov (United States)

    Li, Zhaoguo; Chen, Taishi; Pan, Haiyang; Song, Fengqi; Wang, Baigeng; Han, Junhao; Qin, Yuyuan; Wang, Xuefeng; Zhang, Rong; Wan, Jianguo; Xing, Dingyu; Wang, Guanghou

    2012-01-01

    The universal conductance fluctuations (UCFs), one of the most important manifestations of mesoscopic electronic interference, have not yet been demonstrated for the two-dimensional surface state of topological insulators (TIs). Even if one delicately suppresses the bulk conductance by improving the quality of TI crystals, the fluctuation of the bulk conductance still keeps competitive and difficult to be separated from the desired UCFs of surface carriers. Here we report on the experimental evidence of the UCFs of the two-dimensional surface state in the bulk insulating Bi2Te2Se microflakes. The solely-B⊥-dependent UCF is achieved and its temperature dependence is investigated. The surface transport is further revealed by weak antilocalizations. Such survived UCFs of the surface states result from the limited dephasing length of the bulk carriers in ternary crystals. The electron-phonon interaction is addressed as a secondary source of the surface state dephasing based on the temperature-dependent scaling behavior.

  20. Solid State Dye Solar Cells with Metallic Regenerators towards devices with enhanced active area

    Energy Technology Data Exchange (ETDEWEB)

    Lenzmann, F.O.; Olson, C.; Pichon, P.Y.; Heurtault, B.; Goris, M.J.A.A.; Budel, T. [ECN Solar Energy, Westerduinweg 3, NL-1755 LE Petten (Netherlands)

    2007-08-15

    In an alternative approach to solid state dye solar cells a molecular dye is situated at the interface between a TiO2 film and a metallic (Au) film. In a proof of principle with flat model devices, we have shown earlier that the Au layer efficiently regenerates the charge-neutral state of the dye upon electron injection into the TiO2 conduction band under illumination. For practically more relevant devices an increased active area is required for enhanced current output. A specially adapted TiO2 morphology with nanotubular morphology can minimize reflection losses from the metallic regenerator. In this paper the preparation of such films on transparent SnO2:F-coated glass substrates by electrochemical anodization of titanium layers is described. The focus is on preparative parameters with direct influence on film properties relevant to the application in solid-state dye solar cells (transparency and mechanical integrity of the layers)

  1. Composition Related Electrical Active Defect States of InGaAs and GaAsN

    Directory of Open Access Journals (Sweden)

    Arpad Kosa

    2017-01-01

    Full Text Available This paper discusses results of electrically active defect states - deep energy level analysis in InGaAs and GaAsN undoped semiconductor structures grown for solar cell applications. Main attention is focused on composition and growth condition dependent impurities and the investigation of their possible origins. For this purpose a widely utilized spectroscopy method, Deep Level Transient Fourier Spectroscopy, was utilized. The most significant responses of each sample labelled as InG2, InG3 and NG1, NG2 were discussed in detail and confirmed by simulations and literature data. The presence of a possible dual conduction type and dual state defect complex, dependent on the In/N composition, is reported. Beneficial characteristics of specific indium and nitrogen concentrations capable of eliminating or reducing certain point defects and dislocations are stated.

  2. Learning shapes spontaneous activity itinerating over memorized states.

    Directory of Open Access Journals (Sweden)

    Tomoki Kurikawa

    Full Text Available Learning is a process that helps create neural dynamical systems so that an appropriate output pattern is generated for a given input. Often, such a memory is considered to be included in one of the attractors in neural dynamical systems, depending on the initial neural state specified by an input. Neither neural activities observed in the absence of inputs nor changes caused in the neural activity when an input is provided were studied extensively in the past. However, recent experimental studies have reported existence of structured spontaneous neural activity and its changes when an input is provided. With this background, we propose that memory recall occurs when the spontaneous neural activity changes to an appropriate output activity upon the application of an input, and this phenomenon is known as bifurcation in the dynamical systems theory. We introduce a reinforcement-learning-based layered neural network model with two synaptic time scales; in this network, I/O relations are successively memorized when the difference between the time scales is appropriate. After the learning process is complete, the neural dynamics are shaped so that it changes appropriately with each input. As the number of memorized patterns is increased, the generated spontaneous neural activity after learning shows itineration over the previously learned output patterns. This theoretical finding also shows remarkable agreement with recent experimental reports, where spontaneous neural activity in the visual cortex without stimuli itinerate over evoked patterns by previously applied signals. Our results suggest that itinerant spontaneous activity can be a natural outcome of successive learning of several patterns, and it facilitates bifurcation of the network when an input is provided.

  3. The oligomeric state of the active Vps4 AAA ATPase

    Science.gov (United States)

    Monroe, Nicole; Han, Han; Gonciarz, Malgorzata D.; Eckert, Debra M.; Karren, Mary Anne; Whitby, Frank G.; Sundquist, Wesley I.; Hill, Christopher P.

    2013-01-01

    The cellular ESCRT pathway drives membrane constriction toward the cytosol and effects membrane fission during cytokinesis, endosomal sorting, and the release of many enveloped viruses, including HIV. A component of this pathway, the AAA ATPase Vps4, provides energy for pathway progression. Although it is established that Vps4 functions as an oligomer, subunit stoichiometry and other fundamental features of the functional enzyme are unclear. Higher-order oligomers have thus far only been characterized for a Walker B mutant of Vps4 in the presence of ATP. Here, we report that although some mutant Vps4 proteins form dodecameric assemblies, active wild-type S. cerevisiae and S. solfataricus Vps4 enzymes can form hexamers in the presence of ATP and ADP, as assayed by size exclusion chromatography and equilibrium analytical ultracentifugation. The Vta1p activator binds hexameric yeast Vps4p without changing the oligomeric state of Vps4p, implying that the active Vta1p:Vps4p complex also contains a single hexameric ring. Additionally, we report crystal structures of two different archaeal Vps4 homologs, whose structures and lattice interactions suggest a conserved mode of oligomerization. Disruption of the proposed hexamerization interface by mutagenesis abolished the ATPase activity of archaeal Vps4 proteins and blocked Vps4p function in S. cerevisiae. These data challenge the prevailing model that active Vps4 is a double ring dodecamer, and argue that, like other type I AAA ATPases, Vps4 functions as a single ring with six subunits. PMID:24161953

  4. Results of the pilot proof of the inquiry activities conducted in the science center

    Science.gov (United States)

    Kireš, Marián; BilišÅanská, Mária

    2017-01-01

    The science center SteelPARK Košice offers more than 60 interactive exhibits focused on presenting scientific principles and technical solutions connected to the production and manufacture of steel, research of its properties and its various industrial uses. We are trying to enhance the attractivity of the modern style of the exhibitions and its potential to engage students of ground and middle schools in acquiring new knowledge and capabilities, by means of the inquiry science center. Two laboratory measurements, for 5 three-person teams are provided once a month. During the introductory discussion on the activity, they are asked to answer a series of conceptual questions, which help determine their level of understanding at the beginning of the exercise. The measurements are based in guided inquiry, where the work progress is given a forehand, but the desired result is not. Every activity is focused on developing specific research capabilities. This is being monitored through a self-evaluation card, which every participants is required to fill out immediately after completing the activity. The work is tutored by a lecturer from the students of didactics. During two years and running 15 different activities, we have been able to gather information from more than 6000 students of ground and middle schools. Specific physics measurements, their respective conceptual questions, worksheets and final reports are being presented in this article. We evaluate the present level of conceptual understanding based on the acquired data and give recommendation to teachers on ways to improve the student's capabilities. The teacher, by way of observing the activity, the work of the lecturer and the students, is able to form an understanding of the inquiry activity for their own school practice, for which he/she can use all available methodical and work materials.

  5. About the way of choice of conduct of boxer in competition activity

    Directory of Open Access Journals (Sweden)

    Arkhangorodskiy Z.S.

    2010-10-01

    Full Text Available The features of emotional perception of colour tones are considered for boxers. In researches took part 122 examinee. In an experiment was used eightcolour test. Information is generalized about the choice of colour tones in 14 researches. It is rotined that the emotional choice of colour tones depends on the situation factors of sporting activity and individual features of boxers. It is set that between the emotional preference of colour tones and style of battle activity of boxer there is close intercommunication.

  6. 76 FR 50457 - Taking and Importing Marine Mammals; Military Training Activities and Research Conducted Within...

    Science.gov (United States)

    2011-08-15

    ... training, maintenance, and research, development, testing, and evaluation (RDT&E) activities to be... sampling and photography of a group of pilot whales. From March 20 to April 11, 2010, visual observations... and biopsy sampling. A single biopsy sample was collected from a sei whale in the waters off of...

  7. 77 FR 46606 - Enforcement of Nondiscrimination on the Basis of Disability in Programs and Activities Conducted...

    Science.gov (United States)

    2012-08-06

    ... Protection. It sets forth standards for what constitutes discrimination on the basis of mental or physical... of the Act, the Bureau began to exercise its authorities to regulate the offering and provision of... major depression, or subject to remission, such as cancer, will be evaluated as if they were active....

  8. Atrial activation during atrioventricular nodal reentrant tachycardia: Studies on retrograde fast pathway conduction

    NARCIS (Netherlands)

    D.G. Katritsis; K.A. Ellenbogen; A.E. Becker

    2006-01-01

    BACKGROUND Detailed right and left septal mapping of retrograde atrial activation during typical atrioventricutar nodal reentrant tachycardia (AVNRT) has not been undertaken and may provide insight into the complex physiology of AVNRT, especially the anatomic localization of the fast and stow pathwa

  9. A state-of-the-art assessment of active structures

    Science.gov (United States)

    1992-09-01

    A state-of-the-art assessment of active structures with emphasis towards the applications in aeronautics and space is presented. It is felt that since this technology area is growing at such a rapid pace in many different disciplines, it is not feasible to cover all of the current research but only the relevant work as relates to aeronautics and space. Research in smart actuation materials, smart sensors, and control of smart/intelligent structures is covered. In smart actuation materials, piezoelectric, magnetostrictive, shape memory, electrorheological, and electrostrictive materials are covered. For sensory materials, fiber optics, dielectric loss, and piezoelectric sensors are examined. Applications of embedded sensors and smart sensors are discussed.

  10. Activities of binary baths with 1% solute as standard states

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The relationships of activities with 1% solute as standard state and mass fraction of solute, and hot-dip temperature, were given on the base of Miedema's model, Tanaka expression, some basic thermodynamic relationships; and discussion was carried out on Zn-Mn and Zn-Ti binary alloys by calculation, in which varied colors can be achieved on the hot-dip steel sheets. The results indicate that the activity of solute shows positive deviation relative to Henry's law for both Zn-Mn and Zn-Ti binary dilute solution. The degree of deviation increases with increasing solute and decreases with increasing bath temperature. As the solution is very dilute solution (w(Mn)≤40% for Zn-Mn alloy,w(Ti)≤8% for Zn-Ti alloy), the two binary baths can all be treated as ideal dilute solutions.

  11. Evaluation of behavioral states among morning and evening active healthy individuals

    Directory of Open Access Journals (Sweden)

    M.P. Hidalgo

    2002-07-01

    Full Text Available The Horne-Östberg questionnaire partly covers some factors that may be important determinants of peak time and characterize patterns of behavior. We conducted a study for the evaluation of self-reported behavioral states (hunger sensation, availability for study, physical exercise, solving daily problems, and time preferences as expressions of underlying cyclic activity. Three hundred and eighteen community subjects without history of medical, psychiatric, or sleep disorders were evaluated in a cross-sectional design. A self-report about daily highest level of activity was used to categorize individuals into morning, evening, and indifferently active. Time-related behavioral states were evaluated with 23 visual analog questions. The responses to most analogic questions were significantly different between morning and evening active subjects. Logistic regression analysis identified a group of behaviors more strongly associated with the self-reported activity pattern (common wake up time, highest subjective fatigue, as well as wake up, bedtime, exercise and study preferences. These findings suggested that the patterns of activity presented by normal adults were related to specific common behavioral characteristics that may contribute to peak time.

  12. NONLINEAR J-E CHARACTERISTICS IN THE ELECTRIC-THERMAL EQUILIBRIUM STATE FOR HIGH DENSITY POLYETHYLENE CONDUCTIVE COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Qiang Zheng; Yi-hu Song; Xiao-su Yi

    2001-01-01

    The nonlinear J-E characteristics under self-heating equilibrium for conductive composites based on high density polyethylene were studied. The results show that there are identical conduction mechanisms under self-heating equilibrium for the composites with various initial resistivities determined by filler content or ambient temperature. The nonlinear conduction behavior was involved in the limited microstructure transformations of the conducting network induced by electrical field applied and the corresponding self-heating effect. A reversible thermal fuse (RTF) model was suggested to interpret the physical origin of the nonlinear J-E characteristics.

  13. Guinea worm (Dracunculus medinensis) eradication: a pilot study conducted at the Ohaukwu Local Government Areas, Ebonyi State, Nigeria, West Africa.

    Science.gov (United States)

    Ogamdi, S O; Onwe, F

    2001-01-01

    The incidence and the prevalence of Guinea worm disease, a major cause of disability and a frequent cause of serious permanent deformity, were both drastically reduced in Ohaukwu Local Government Communities, with the provision (through bore holes) of a safer form of drinking water. Since 1986, the Carter Center program has been working to eradicate Guinea worm. The bore holes were dug through the Wasatan Project, a Japanese-funded grant awarded to the Enugu State Ministry of Health to help provide safer drinking water in the local communities. Bore holes were dug in several communities in Ohaukwu Local Government Areas between January 1991 and June 1991. The number of Guinea worm cases in the selected communities was ascertained and recorded by health workers. There was more than a 90% reduction in the number of Guinea worm (Dracunculus medinensis) cases after one year. Data collection began in June 1991, shortly after the completion of bore holes in the selected communities. By December 1998, when one of the villages was spot checked for Guinea worm infection, no active case was found. There is a need for post evaluation of all the villages studied to determine the current prevalence of Guinea worm disease.

  14. Dog Walking and Physical Activity in the United States

    Directory of Open Access Journals (Sweden)

    Sandra A. Ham, MS

    2006-03-01

    Full Text Available Introduction Dog walking is a purposeful physical activity that may have health benefits for humans and canines. A descriptive epidemiology of the contribution of dog walking to physically active lifestyles among dog walkers in the United States has not been previously reported. Methods Data on youth and adults who reported walking for pet care trips (N = 1282 on the National Household Travel Survey 2001 were analyzed for number of trips, proportion walking a dog for at least 10 minutes on one trip, and accumulation of 30 minutes or more in 1 day of walks lasting at least 10 minutes. Results In 1 day, 58.9% of dog walkers took two or more walks, 80.2% took at least one walk of 10 minutes or more, and 42.3% accumulated 30 minutes or more from walks lasting at least 10 minutes each. There were no significant differences by sex, family income, or categories of urbanization. Conclusion Walking a dog may contribute to a physically active lifestyle and should be promoted as a strategy that fits within the framework set forth by the Task Force on Community Preventive Services for Physical Activity.

  15. The Activation Effect of Hainantoxin-I, a Peptide Toxin from the Chinese Spider, Ornithoctonus hainana, on Intermediate-Conductance Ca2+-Activated K+ Channels

    Directory of Open Access Journals (Sweden)

    Pengfei Huang

    2014-08-01

    Full Text Available Intermediate-conductance Ca2+-activated K+ (IK channels are calcium/calmodulin-regulated voltage-independent K+ channels. Activation of IK currents is important in vessel and respiratory tissues, rendering the channels potential drug targets. A variety of small organic molecules have been synthesized and found to be potent activators of IK channels. However, the poor selectivity of these molecules limits their therapeutic value. Venom-derived peptides usually block their targets with high specificity. Therefore, we searched for novel peptide activators of IK channels by testing a series of toxins from spiders. Using electrophysiological experiments, we identified hainantoxin-I (HNTX-I as an IK-channel activator. HNTX-I has little effect on voltage-gated Na+ and Ca2+ channels from rat dorsal root ganglion neurons and on the heterologous expression of voltage-gated rapidly activating delayed rectifier K+ channels (human ether-à-go-go-related gene; human ERG in HEK293T cells. Only 35.2% ± 0.4% of the currents were activated in SK channels, and there was no effect on BK channels. We demonstrated that HNTX-I was not a phrenic nerve conduction blocker or acutely toxic. This is believed to be the first report of a peptide activator effect on IK channels. Our study suggests that the activity and selectivity of HNTX-I on IK channels make HNTX-I a promising template for designing new drugs for cardiovascular diseases.

  16. Gis-approach for variability assessment of soil electric conductivity under pedoturbation activity of mole rat (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2010-06-01

    Full Text Available The results of the investigation of the impact of the mole rat’s activity on soil electric conductivity have been presented. GIS-technology have been shown to be effective for assessment of the pedoturbation activity effect on the soil surface heterogeneity formation. Method of the one-dimension spatial coordinated array transformation into matrix form has been proposed for following multidimension statistic analysis application. The quantity estimation of the mole rats role in formation of the habitat nanorelief-level diversity has been obtained by means of indexes of the landscape complexity and diversity.

  17. Assessment of Pozzolanic Activity Using Methods Based on the Measurement of Electrical Conductivity of Suspensions of Portland Cement and Pozzolan

    Directory of Open Access Journals (Sweden)

    Sergio Velázquez

    2014-11-01

    Full Text Available The use of methods based on measuring electrical conductivity to assess pozzolanic activity has recently been used primarily in aqueous suspensions of pozzolan: calcium hydroxide. However, the use of similar methods in suspensions of cement with pozzolans has not been widely studied. This paper proposes a new method for rapid assessment of the pozzolanic activity of mineral admixtures in aqueous cement suspensions. In this study, the conditions for the application of the method were optimized, such as time, temperature, w/c ratio and dosage procedure. Finally, results are presented from the application of this method for characterizing the pozzolanic activity of the spent catalytic cracking catalyst. These results corroborate as previously reported, namely the high reactivity of this pozzolan obtained by other methods, such as thermogravimetry or evolution of the mechanical strength. In addition, the pozzolanic activity of the catalyst was compared with other pozzolans such as metakaolin and silica fume.

  18. GPi oscillatory activity differentiates tics from the resting state, voluntary movements, and the unmedicated parkinsonian state

    Directory of Open Access Journals (Sweden)

    Joohi Jimenez-Shahed

    2016-09-01

    Full Text Available Background: Deep brain stimulation (DBS is an emerging treatment strategy for severe, medication-refractory Tourette syndrome (TS. Thalamic (Cm-Pf and pallidal (including globus pallidus interna, GPi targets have been the most investigated. While the neurophysiological correlates of Parkinson’s disease (PD in the GPi and subthalamic nucleus (STN are increasingly recognized, these patterns are not well characterized in other disease states. Recent findings indicate that the cross-frequency coupling (CFC between beta band and high frequency oscillations (HFOs within the STN in PD patients is pathologic. Methods: We recorded intraoperative local field potentials (LFPs from the postero-ventrolateral GPi in three adult patients with TS at rest, during voluntary movements, and during tic activity and compared them to the intraoperative GPi-LFP activity recorded from four unmedicated PD patients at rest. Results: In all PD patients, we noted excessive beta band activity (13-30Hz at rest which consistently modulated the amplitude of the co-existent HFOs observed between 200-400Hz, indicating the presence of beta-HFO CFC. In all 3 TS patients at rest, we observed theta band activity (4-7Hz and HFOs. Two patients had beta band activity, though at lower power than theta oscillations. Tic activity was associated with increased high frequency (200-400Hz and gamma band (35-200Hz activity. There was no beta-HFO CFC in TS patients at rest. However, CFC between the phase of 5-10Hz band activity and the amplitude of HFOs was found in two TS patients. During tics, this shifted to CFC between the phase of beta band activity and the amplitude of HFOs in all subjects. Conclusions: To our knowledge this is the first study that shows that beta-HFO CFC exists in the GPi of TS patients during tics and at rest in PD patients, and suggests that this pattern might be specific to pathologic/involuntary movements. Furthermore, our findings suggest that during tics, resting

  19. GPi Oscillatory Activity Differentiates Tics from the Resting State, Voluntary Movements, and the Unmedicated Parkinsonian State

    Science.gov (United States)

    Jimenez-Shahed, Joohi; Telkes, Ilknur; Viswanathan, Ashwin; Ince, Nuri F.

    2016-01-01

    Background: Deep brain stimulation (DBS) is an emerging treatment strategy for severe, medication-refractory Tourette syndrome (TS). Thalamic (Cm-Pf) and pallidal (including globus pallidus interna, GPi) targets have been the most investigated. While the neurophysiological correlates of Parkinson's disease (PD) in the GPi and subthalamic nucleus (STN) are increasingly recognized, these patterns are not well characterized in other disease states. Recent findings indicate that the cross-frequency coupling (CFC) between beta band and high frequency oscillations (HFOs) within the STN in PD patients is pathologic. Methods: We recorded intraoperative local field potentials (LFPs) from the postero-ventrolateral GPi in three adult patients with TS at rest, during voluntary movements, and during tic activity and compared them to the intraoperative GPi-LFP activity recorded from four unmedicated PD patients at rest. Results: In all PD patients, we noted excessive beta band activity (13–30 Hz) at rest which consistently modulated the amplitude of the co-existent HFOs observed between 200 and 400 Hz, indicating the presence of beta-HFO CFC. In all 3TS patients at rest, we observed theta band activity (4–7 Hz) and HFOs. Two patients had beta band activity, though at lower power than theta oscillations. Tic activity was associated with increased high frequency (200–400 Hz) and gamma band (35–200 Hz) activity. There was no beta-HFO CFC in TS patients at rest. However, CFC between the phase of 5–10 Hz band activity and the amplitude of HFOs was found in two TS patients. During tics, this shifted to CFC between the phase of beta band activity and the amplitude of HFOs in all subjects. Conclusions: To our knowledge this is the first study that shows that beta-HFO CFC exists in the GPi of TS patients during tics and at rest in PD patients, and suggests that this pattern might be specific to pathologic/involuntary movements. Furthermore, our findings suggest that during tics

  20. Hypotonicity induced K+ and anion conductive pathways activation in eel intestinal epithelium

    DEFF Research Database (Denmark)

    Lionetto, M G; Giordano, M E; De Nuccio, F

    2005-01-01

    , the activation of 'emergency' systems of rapid cell volume regulation is fundamental in their physiology. The aim of the present work was to study the physiological response to hypotonic stress in a salt-transporting epithelium, the intestine of the euryhaline teleost Anguilla anguilla. Eel intestinal epithelium......(te)) and the short circuit current (I(sc)). This electrophysiological response correlated with a regulatory volume decrease (RVD) response, recorded by morphometrical measurement of the epithelium height. Changes in the transepithelial resistance were also observed following the hypotonicity exposure...

  1. Resting-state brain activity in adult males who stutter.

    Directory of Open Access Journals (Sweden)

    Yun Xuan

    Full Text Available Although developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI, few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF, region of interest (ROI-based functional connectivity (FC and independent component analysis (ICA-based FC. Forty-four adult males with developmental stuttering and 46 age-matched fluent male controls were scanned using resting-state fMRI. ALFF, ROI-based FCs and ICA-based FCs were compared between male stuttering subjects and fluent controls in a voxel-wise manner. Compared with fluent controls, stuttering subjects showed increased ALFF in left brain areas related to speech motor and auditory functions and bilateral prefrontal cortices related to cognitive control. However, stuttering subjects showed decreased ALFF in the left posterior language reception area and bilateral non-speech motor areas. ROI-based FC analysis revealed decreased FC between the posterior language area involved in the perception and decoding of sensory information and anterior brain area involved in the initiation of speech motor function, as well as increased FC within anterior or posterior speech- and language-associated areas and between the prefrontal areas and default-mode network (DMN in stuttering subjects. ICA showed that stuttering subjects had decreased FC in the DMN and increased FC in the sensorimotor network. Our findings support the concept that stuttering subjects have deficits in multiple functional systems (motor, language, auditory and DMN and in the connections between them.

  2. N-terminal isoforms of the large-conductance Ca²⁺-activated K⁺ channel are differentially modulated by the auxiliary β1-subunit.

    Science.gov (United States)

    Lorca, Ramón A; Stamnes, Susan J; Pillai, Meghan K; Hsiao, Jordy J; Wright, Michael E; England, Sarah K

    2014-04-04

    The large-conductance Ca(2+)-activated K(+) (BK(Ca)) channel is essential for maintaining the membrane in a hyperpolarized state, thereby regulating neuronal excitability, smooth muscle contraction, and secretion. The BK(Ca) α-subunit has three predicted initiation codons that generate proteins with N-terminal ends starting with the amino acid sequences MANG, MSSN, or MDAL. Because the N-terminal region and first transmembrane domain of the α-subunit are required for modulation by auxiliary β1-subunits, we examined whether β1 differentially modulates the N-terminal BK(Ca) α-subunit isoforms. In the absence of β1, all isoforms had similar single-channel conductances and voltage-dependent activation. However, whereas β1 did not modulate the voltage-activation curve of MSSN, β1 induced a significant leftward shift of the voltage activation curves of both the MDAL and MANG isoforms. These shifts, of which the MDAL was larger, occurred at both 10 μM and 100 μM Ca(2+). The β1-subunit increased the open dwell times of all three isoforms and decreased the closed dwell times of MANG and MDAL but increased the closed dwell times of MSSN. The distinct modulation of voltage activation by the β1-subunit may be due to the differential effect of β1 on burst duration and interburst intervals observed among these isoforms. Additionally, we observed that the related β2-subunit induced comparable leftward shifts in the voltage-activation curves of all three isoforms, indicating that the differential modulation of these isoforms was specific to β1. These findings suggest that the relative expression of the N-terminal isoforms can fine-tune BK(Ca) channel activity in cells, highlighting a novel mechanism of BK(Ca) channel regulation.

  3. Are Physical Activity and Academic Performance Compatible? Academic Achievement, Conduct, Physical Activity and Self-Esteem of Hong Kong Chinese Primary School Children

    Science.gov (United States)

    Yu, C. C. W.; Chan, Scarlet; Cheng, Frances; Sung, R. Y. T.; Hau, Kit-Tai

    2006-01-01

    Education is so strongly emphasized in the Chinese culture that academic success is widely regarded as the only indicator of success, while too much physical activity is often discouraged because it drains energy and affects academic concentration. This study investigated the relations among academic achievement, self-esteem, school conduct and…

  4. What should be the roles of conscious states and brain states in theories of mental activity?

    Directory of Open Access Journals (Sweden)

    Donelson E Dulany

    2011-03-01

    Full Text Available Answers to the title's question have been influenced by a history in which an early science of consciousness was rejected by behaviourists on the argument that this entails commitment to ontological dualism and "free will" in the sense of indeterminism. This is, however, a confusion of theoretical assertions with metaphysical assertions. Nevertheless, a legacy within computational and information-processing views of mind rejects or de-emphasises a role for consciousness. This paper sketches a mentalistic metatheory in which conscious states are the sole carriers of symbolic representations, and thus have a central role in the explanation of mental activity and action-while specifying determinism and materialism as useful working assumptions. A mentalistic theory of causal learning, experimentally examined with phenomenal reports, is followed by examination of these questions: Are there common roles for phenomenal reports and brain imaging? Is there defensible evidence for unconscious brain states carrying symbolic representations? Are there interesting dissociations within consciousness?

  5. Glutamate and GABA activate different receptors and Cl(-) conductances in crab peptide-secretory neurons.

    Science.gov (United States)

    Duan, S; Cooke, I M

    2000-01-01

    Responses to rapid application of glutamic acid (Glu) and gamma-aminobutyric acid (GABA), 0.01-3 mM, were recorded by whole-cell patch clamp of cultured crab (Cardisoma carnifex) X-organ neurons. Responses peaked within 200 ms. Both Glu and GABA currents had reversal potentials that followed the Nernst Cl(-) potential when [Cl(-)](i) was varied. A Boltzmann fit to the normalized, averaged dose-response curve for Glu indicated an EC(50) of 0.15 mM and a Hill coefficient of 1.05. Rapid (t(1/2) approximately 1 s) desensitization occurred during Glu but not GABA application that required >2 min for recovery. Desensitization was unaffected by concanavalin A or cyclothiazide. N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, quisqualate, and kainate (to 1 mM) were ineffective, nor were Glu responses influenced by glycine (1 microM) or Mg(2+) (0-26 mM). Glu effects were imitated by ibotenic acid (0.1 mM). The following support the conclusion that Glu and GABA act on different receptors: 1) responses sum; 2) desensitization to Glu or ibotenic acid did not diminish GABA responses; 3) the Cl(-)-channel blockers picrotoxin and niflumic acid (0.5 mM) inhibited Glu responses by approximately 90 and 80% but GABA responses by approximately 50 and 20%; and 4) polyvinylpyrrolydone-25 (2 mM in normal crab saline) eliminated Glu responses but left GABA responses unaltered. Thus crab secretory neurons have separate receptors responsive to Glu and to GABA, both probably ionotropic, and mediating Cl(-) conductance increases. In its responses and pharmacology, this crustacean Glu receptor resembles Cl(-)-permeable Glu receptors previously described in invertebrates and differs from cation-permeable Glu receptors of vertebrates and invertebrates.

  6. Solar activity and atmospheric tide effect on the polar conductivity and the vertical electric field in the stratosphere at low latitude

    Science.gov (United States)

    Gupta, S. P.

    2004-01-01

    Balloonborne measurements of the polar conductivity and the vertical electric field were carried out over a period of 1984-1994 from Hyderabad, Central India. The conductivity values show positive correlation with solar activity between 20 and 35 km. Between 5 and 20 km the conductivity values show an anti-correlation with solar activity. The vertical electric field does not show solar cycle effect. However, the electric field and the conductivity show a semi-diurnal variation at balloon float altitude.

  7. Trap states extraction of p-channel SnO thin-film transistors based on percolation and multiple trapping carrier conductions

    Science.gov (United States)

    Qiang, Lei; Liu, Wuguang; Pei, Yanli; Wang, Gang; Yao, Ruohe

    2017-03-01

    A new method is proposed to extract the trap states in p-channel SnO thin-film transistors (TFTs). In this method, the dominant conduction mechanisms under different temperatures have been taken into account. There are percolation and multiple trapping conduction mechanisms. Combined with the drain current-temperature (Ids-T) and capacitance-voltage (C-V) measurements, the variation of trap states concentrations with the surface potential is derived. Results show that energy-dependent density of states (DOS) is in the order of 1019 eV/cm3. And the maximum of the density of states at the interface between the gate dielectric and the SnO channel is Nss = 1.77 × 1014 cm-2 eV-1.

  8. Integrating high electrical conductivity and photocatalytic activity in cotton fabric by cationizing for enriched coating of negatively charged graphene oxide.

    Science.gov (United States)

    Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-10-01

    Electroconductive textiles have attended tremendous focus recently and researchers are making efforts to increase conductivity of e-textiles, in order to increase the use of such flexible and low cost textile materials. In this study, surface conductivity and photo catalytic activity of standard cotton fabric (SCF) was enhanced by modifying its surface charge, from negative to positive, using Bovine Serum Albumin (BSA) as a cationic agent, to convert it into cationised cotton fabric (CCF). Then, both types of fabrics were dip coated with a simple dip and dry technique for the adsorption of negatively charged graphene oxide (GO) sheets onto its surface. This resulted in 67.74% higher loading amount of GO on the CCF making self-assembly. Finally, this coating was chemically converted by vapor reduction using hydrazine hydrate to reduced graphene oxide (rGO) for restoration of a high electrical conductivity at the fabric surface. Our results revealed that with such high loading of GO, the surface resistance of CCF was only 40Ω/sq as compared to 510Ω/sq of the SCF and a 66% higher photo catalytic activity was also achieved through cationization for improved GO coating. Graphene coated SCF and CCF were characterized using FE-SEM, FTIR, Raman, UV-vis, WAXD, EDX and XPS spectroscopy to ascertain successful reduction of GO to rGO. The effect of BSA treatment on adsorption of cotton fabric was studied using drop shape analyzer to measure contact angle and for thermal and mechanical resistance, the fabric was tested for TGA and tensile strength, respectively. rGO coated fabric also showed slightly improved thermal stability yet a minor loss of strength was observed. The high flexibility, photocatalytic activity and excellent conductivity of this fabric suggests that it can be used as an electrode material for various applications.

  9. GDP and carboxyatractylate inhibit 4-hydroxynonenal-activated proton conductance to differing degrees in mitochondria from skeletal muscle and heart.

    Science.gov (United States)

    Aguirre, Enara; Cadenas, Susana

    2010-10-01

    The lipid peroxidation product 4-hydroxynonenal (HNE) increases the proton conductance of the inner mitochondrial membrane through effects on uncoupling proteins (UCPs) and the adenine nucleotide translocase (ANT); however, the relative contribution of the two carriers to these effects is unclear. To clarify this we isolated mitochondria from skeletal muscle and heart of wild-type and Ucp3 knockout (Ucp3KO) mice. To increase UCP3 expression, some mice were i.p. injected with LPS (12mg/kg body weight). In spite of the increased UCP3 expression levels, basal proton conductance did not change. HNE increased the proton conductance of skeletal muscle and heart mitochondria. In skeletal muscle, this increase was lower in Ucp3KO mice and higher in LPS-treated wild-type mice, and was partially abolished by GDP (UCPs inhibitor) and completely abolished by carboxyatractylate (ANT inhibitor) or addition of both inhibitors. GDP had no effect on HNE-induced conductance in heart mitochondria, but carboxyatractylate or administration of both inhibitors had a partial effect. GDP-mediated inhibition of HNE-activated proton conductance in skeletal muscle mitochondria was not observed in Ucp3KO mice, indicating that GDP is specific for UCP3, at least in muscle. Carboxyatractylate was able to inhibit UCP3, probably through an indirect mechanism. Our results are consistent with the conclusion that, in skeletal muscle, HNE-induced increase in proton conductance is mediated by UCP3 (30%) and ANT, whereas in the heart the increase is mediated by ANT and other carriers, possibly including UCP3.

  10. The Inhibition by Oxaliplatin, a Platinum-Based Anti-Neoplastic Agent, of the Activity of Intermediate-Conductance Ca2+-Activated K+ Channels in Human Glioma Cells

    Directory of Open Access Journals (Sweden)

    Mei-Han Huang

    2015-10-01

    Full Text Available Oxaliplatin (OXAL is a third-generation organoplatinum which is effective against advanced cancer cells including glioma cells. How this agent and other related compounds interacts with ion channels in glioma cells is poorly understood. OXAL (100 µM suppressed the amplitude of whole-cell K+ currents (IK; and, either DCEBIO or ionomycin significantly reversed OXAL-mediated inhibition of IK in human 13-06-MG glioma cells. In OXAL-treated cells, TRAM-34 did not suppress IK amplitude in these cells. The intermediate-conductance Ca2+-activated K+ (IKCa channels subject to activation by DCEBIO and to inhibition by TRAM-34 or clotrimazole were functionally expressed in these cells. Unlike cisplatin, OXAL decreased the probability of IKCa-channel openings in a concentration-dependent manner with an IC50 value of 67 µM. No significant change in single-channel conductance of IKCa channels in the presence of OXAL was demonstrated. Neither large-conductance Ca2+-activated K+ channels nor inwardly rectifying K+ currents in these cells were affected in the presence of OXAL. OXAL also suppressed the proliferation and migration of 13-06-MG cells in a concentration- and time-dependent manner. OXAL reduced IKCa-channel activity in LoVo colorectal cancer cells. Taken together, the inhibition by OXAL of IKCa channels would conceivably be an important mechanism through which it acts on the functional activities of glioma cells occurring in vivo.

  11. Electrospun conducting polymer nanofibers as the active material in sensors and diodes

    Science.gov (United States)

    Pinto, Nicholas J.

    2013-03-01

    Polyaniline doped with camphorsulfonic acid (PANi-HCSA) and poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSSA) were electrospun separately to obtain individual nanofibers which were captured on Si/SiO2 substrates and electrically characterized. The fiber resistance was recorded as a function of time in the presence of vapours of aliphatic alcohols of varying sizes. Due to the large surface to volume ratio, uniform diameter and small quantity of active material used in the construction, these sensor responses are very quick. Sensors made from individual fibers also show true saturation upon exposure to and removal of the sensing gas. A Schottky diode was also fabricated using an n-doped Si/SiO2 substrate and a single PANi-HCSA fiber and tested in vacuum and in ammonia gas. The diode response was instantaneous upon exposure to ammonia with nearly complete recovery of the current upon pumping out the ammonia, thereby making it a reusable sensor with rectifying behaviour i.e. multifunctional.

  12. Numerical study of electronic density of states and conductance of a molecular wire coupled with an external molecule

    Directory of Open Access Journals (Sweden)

    S. A. Ketabi

    2006-12-01

    Full Text Available   There is a great interest in the electronic properties of conjugated polymers. Numerous works on the electronic and conduction properties of single-chain conjugated polymers have been published. From an electronic conduction point of view, these systems are quasi-one dimensional. The aim of this paper is to try to investigate corresponding properties in conducting polymers in higher of one-dimension. We study the electronic properties of a polyacetylene chain connected to other molecules. The effect of the size of the molecule and the strength of the coupling to the molecular wire is investigated. The results show that with the increase of the strength of the molecular wire/molecule coupling, the band gap of the system decreases and causes high electronic conduction.

  13. Reinforcing Regulatory Regimes: How States, Civil Society, and Codes of Conduct Promote Adherence to Global Labor Standards

    OpenAIRE

    2012-01-01

    In response to pressure from various stakeholders, many transnational businesses have developed codes of conduct and monitoring systems to ensure that working conditions in their supply chain factories meet global labor standards. Many observers have questioned whether these codes of conduct have any impact on working conditions or are merely a marketing tool to deflect criticism of valuable global brands. Using a proprietary dataset from one of the world’s largest social auditors, containing...

  14. Bournonite PbCuSbS3 : Stereochemically Active Lone-Pair Electrons that Induce Low Thermal Conductivity.

    Science.gov (United States)

    Dong, Yongkwan; Khabibullin, Artem R; Wei, Kaya; Salvador, James R; Nolas, George S; Woods, Lilia M

    2015-10-26

    An understanding of the structural features and bonding of a particular material, and the properties these features impart on its physical characteristics, is essential in the search for new systems that are of technological interest. For several relevant applications, the design or discovery of low thermal conductivity materials is of great importance. We report on the synthesis, crystal structure, thermal conductivity, and electronic-structure calculations of one such material, PbCuSbS3 . Our analysis is presented in terms of a comparative study with Sb2 S3 , from which PbCuSbS3 can be derived through cation substitution. The measured low thermal conductivity of PbCuSbS3 is explained by the distortive environment of the Pb and Sb atoms from the stereochemically active lone-pair s(2) electrons and their pronounced repulsive interaction. Our investigation suggests a general approach for the design of materials for phase-change-memory, thermal-barrier, thermal-rectification and thermoelectric applications, as well as other functions for which low thermal conductivity is purposefully sought.

  15. Mussel-Inspired Anisotropic Nanocellulose and Silver Nanoparticle Composite with Improved Mechanical Properties, Electrical Conductivity and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Hoang-Linh Nguyen

    2016-03-01

    Full Text Available Materials for wearable devices, tissue engineering and bio-sensing applications require both antibacterial activity to prevent bacterial infection and biofilm formation, and electrical conductivity to electric signals inside and outside of the human body. Recently, cellulose nanofibers have been utilized for various applications but cellulose itself has neither antibacterial activity nor conductivity. Here, an antibacterial and electrically conductive composite was formed by generating catechol mediated silver nanoparticles (AgNPs on the surface of cellulose nanofibers. The chemically immobilized catechol moiety on the nanofibrous cellulose network reduced Ag+ to form AgNPs on the cellulose nanofiber. The AgNPs cellulose composite showed excellent antibacterial efficacy against both Gram-positive and Gram-negative bacteria. In addition, the catechol conjugation and the addition of AgNP induced anisotropic self-alignment of the cellulose nanofibers which enhances electrical and mechanical properties of the composite. Therefore, the composite containing AgNPs and anisotropic aligned the cellulose nanofiber may be useful for biomedical applications.

  16. The influence of moisture on the activation energy of the conductivity of paper-oil insulation of power transformers

    Science.gov (United States)

    Kierczyński, Konrad

    2016-09-01

    In the paper presents the influence of moisture content and electric field intensity on the activation energy of the conductivity DC electrical pressboard impregnated with insulating oil in the measuring temperature range of from 20 °C to 80 °C and the electric field intensity range from 10 kV/m to 1000 kV/m. With Arrhenius plots for each of the moisture content and for all seven of the electric field intensity was determined coefficients of determination R2, which are very close to one. This proves the high accuracy of approximation linear experimental results on the Arrhenius plots and highly accurate measurements of conductivity, accurate stabilization and measurements temperature. It was found that the moisture content of range from 1.15% to 6.5% wt. and the electric field intensity does not affect (in the margin of error) on the activation energy value of the DC conductivity, which is (1.0338 +/- 0.02000) eV.

  17. Assessment of the Pozzolanic Activity of a Spent Catalyst by Conductivity Measurement of Aqueous Suspensions with Calcium Hydroxide

    Directory of Open Access Journals (Sweden)

    Sergio Velázquez

    2014-03-01

    Full Text Available The pozzolanic activity of the spent catalyst produced by fluid catalytic cracking (FCC has been studied by various methods in recent years. However, no quick and easy method has been reported for this activity based on the associated studies. In this work, the pozzolanic activity of a spent catalyst was investigated by measuring its electrical conductivity in aqueous suspensions of pozzolan/calcium hydroxide. The behavior of the FCC catalyst residue was compared to that of reactive and inert materials of similar chemical compositions. Further, the influence of temperature on the suspension was studied, and also, a new method was proposed in which the pozzolan/calcium hydroxide ratio was varied (with the initial presence of solid Ca(OH2 in the system. It was concluded that the method is effective, fast and simple for evaluating the high reactivity of the catalyst. Therefore, this method is an alternative for the evaluation of the reactivity of pozzolanic materials.

  18. Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium

    DEFF Research Database (Denmark)

    Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E;

    2008-01-01

    Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work...... and morphometric analysis on the intact tissue. BK(Ca) channels appeared to be localized along all the plasma membrane of the enterocytes; the apical part of the villi showed the most intense immunostaining. These channels were silent in basal condition, but were activated on both membranes (apical and basolateral......) by increasing intracellular Ca(2+) concentration with the Ca(2+) ionophore ionomycin (1 microM). BK(Ca) channels were also activated on both membranes by hypotonic swelling of the epithelium and their inhibition by 100 nM iberiotoxin (specific BK(Ca) inhibitor) abolished the Regulatory Volume Decrease (RVD...

  19. Bidirectional modulation of substantia nigra activity by motivational state.

    Directory of Open Access Journals (Sweden)

    Mark A Rossi

    Full Text Available A major output nucleus of the basal ganglia is the substantia nigra pars reticulata, which sends GABAergic projections to brainstem and thalamic nuclei. The GABAergic (GABA neurons are reciprocally connected with nearby dopaminergic neurons, which project mainly to the basal ganglia, a set of subcortical nuclei critical for goal-directed behaviors. Here we examined the impact of motivational states on the activity of GABA neurons in the substantia nigra pars reticulata and the neighboring dopaminergic (DA neurons in the pars compacta. Both types of neurons show short-latency bursts to a cue predicting a food reward. As mice became sated by repeated consumption of food pellets, one class of neurons reduced cue-elicited firing, whereas another class of neurons progressively increased firing. Extinction or pre-feeding just before the test session dramatically reduced the phasic responses and their motivational modulation. These results suggest that signals related to the current motivational state bidirectionally modulate behavior and the magnitude of phasic response of both DA and GABA neurons in the substantia nigra.

  20. Hypogravity Research and Educational Parabolic Flight Activities Conducted in Barcelona: a new Hub of Innovation in Europe

    Science.gov (United States)

    Perez-Poch, Antoni; González, Daniel Ventura; López, David

    2016-12-01

    We report on different research and educational activities related to parabolic flights conducted in Barcelona since 2008. We use a CAP10B single-engine aerobatic aircraft flying out of Sabadell Airport and operating in visual flight conditions providing up to 8 seconds of hypogravity for each parabola. Aside from biomedical experiments being conducted, different student teams have flown in parabolic flights in the framework of the international contest `Barcelona Zero-G Challenge', and have published their results in relevant symposiums and scientific journals. The platform can certainly be a good testbed for a proof-of-concept before accessing other microgravity platforms, and has proved to be excellent for motivational student campaigns.

  1. Apparent receptor-mediated activation of Ca2+-dependent conductive Cl- transport by shark-derived polyaminosterols.

    Science.gov (United States)

    Chernova, Marina N; Vandorpe, David H; Clark, Jeffrey S; Williams, Jon I; Zasloff, Michael A; Jiang, Lianwei; Alper, Seth L

    2005-12-01

    The shark liver antimicrobial polyaminosterol squalamine is an angiogenesis inhibitor under clinical investigation as an anti-cancer agent and as a treatment for the choroidal neovascularization associated with macular degeneration of the retina. The related polyaminosterol MSI-1436 is an appetite suppressant that decreases systemic insulin resistance. However, the mechanisms of action of these polyaminosterols are unknown. We report effects of MSI-1436 on Xenopus oocytes consistent with the existence of a receptor for polyaminosterols. MSI-1436 activates bidirectional, trans-chloride-independent Cl- flux in Xenopus oocytes. At least part of this DIDS-sensitive Cl- flux is conductive, as measured using two-electrode voltage-clamp and on-cell patch-clamp techniques. MSI-1436 also elevates cytosolic Ca2+ concentration ([Ca2+]) and increases bidirectional 45Ca2+ flux. Activation of Cl- flux and elevation of cytosolic [Ca2+] by MSI-1436 both are accelerated by lowering bath Ca2+ and are not acutely inhibited by extracellular EGTA. Elevation of cytosolic [Ca2+] by MSI-1436 requires heparin-sensitive intracellular Ca2+ stores. Although injected EGTA abolishes the increased conductive Cl- flux, that Cl- flux is not dependent on heparin-sensitive stores. In low-bath Ca2+ conditions, several structurally related polyaminosterols act as strong agonists or weak agonists of conductive Cl- flux in oocytes. Weak agonist polyaminosterols antagonize the strong agonist, MSI-1436, but upon addition of the conductive Cl- transport inhibitor DIDS, they are converted into strong agonists. Together, these properties operationally define a polyaminosterol receptor at or near the surface of the Xenopus oocyte, provide an initial description of receptor signaling, and suggest routes toward further understanding of a novel class of appetite suppressants and angiogenesis inhibitors.

  2. Rules of the New York State Board of Regents Relating to Definitions of Unprofessional Conduct, with Amendments Adopted through November 1984.

    Science.gov (United States)

    New York State Education Dept., Albany.

    Rules concerning unprofessional conduct are offered by the New York State Board of Regents. Attention is directed to: general provisions for all professions, health professions, and design professions (e.g., architecture and engineering), as well as special provisions for: the medical profession, the dentistry and dental hygiene professions, the…

  3. Impedance spectroscopic analysis of composite electrode from activated carbon/conductive materials/ruthenium oxide for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Taer, E.; Awitdrus,; Farma, R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Physics, Faculty of Mathematics and Natural Sciences, University of Riau, 28293 Pekanbaru, Riau (Indonesia); Deraman, M., E-mail: madra@ukm.my; Talib, I. A.; Ishak, M. M.; Omar, R.; Dolah, B. N. M.; Basri, N. H.; Othman, M. A. R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Kanwal, S. [ICCBS, H.E.J. Research Institute of Chemistry, University of Karachi, 75270 Karachi (Pakistan)

    2015-04-16

    Activated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust. Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder (polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC) electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H{sub 2}SO{sub 4} electrolyte, were analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g{sup −1} respectively. Since the addition of CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest specific capacitance of the cells obtained in this study was 86 F g{sup −1}, i.e. for the cell with the resistance of 15 Ohm and composite electrode consists of 5 % ruthenium oxide.

  4. Anisotropy in conductance of a quasi-one-dimensional metallic surface state measured by a square micro-four-point probe method.

    Science.gov (United States)

    Kanagawa, Taizo; Hobara, Rei; Matsuda, Iwao; Tanikawa, Takehiro; Natori, Akiko; Hasegawa, Shuji

    2003-07-18

    We have devised a "square micro-four-point probe method" using an independently driven ultrahigh-vacuum four-tip scanning tunneling microscope, and succeeded for the first time to directly measure anisotropic electrical conductance of a single-atomic layer on a solid surface. A quasi-one-dimensional metal of a single-domain Si(111)4 x 1-In had a surface-state conductance along the metallic atom chains (sigma(axially)) to be 7.2(+/-0.6) x 10(-4) S/square at room temperature, which was larger than that in the perpendicular direction (sigma(radially)) by approximately 60 times. The sigma(axially) was consistently interpreted by a Boltzmann equation with the anisotropic surface-state band dispersion, while the sigma(radially) was dominated by a surface-space-charge-layer conductance.

  5. Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors.

    Science.gov (United States)

    Robles, A; Latrille, E; Ribes, J; Bernet, N; Steyer, J P

    2016-01-01

    The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitoring the start-up period of anaerobic fixed-bed reactors due to its reliability, robustness, easy operation, low cost, and minimum maintenance compared with the currently used sensors.

  6. Hydraulic Conductivity Functions in Relation to Some Chemical Properties in a Cultivated Oxisols of a Humid Region, Delta State, Nigeria

    Directory of Open Access Journals (Sweden)

    Egbuchua, C. N.

    2014-04-01

    Full Text Available The study was conducted to evaluate hydraulic conductivity functions in relation to some soil chemical properties in an oxisols of the tropics. Field and laboratory studies were carried out and data collected, subjected to statistical analytical procedure for computing coefficient of variability and correlation among soil properties. Results of the study showed that hydraulic conductivity functions varied spatially and temporarily across the experimental points with a moderate mean value of 0.0026 cm/h and a coefficient o variation of 31.45% soil chemical properties showed that the soils were acidic with a mean pH value of 5.12. Organic carbon, total nitrogen and available phosphorus were low with mean values of 1.29%, 0.68% and 4.43 mgkg-1. Coefficient of variability among soil properties indicated less to moderately variable. Soil pH had negative correlation with all the soil properties evaluated.

  7. Excess conductivity and the pseudogap state in Hf-doped YBa2Cu3O7-δ ceramics

    Science.gov (United States)

    Savich, S. V.; Samoilov, A. V.; Vovk, R. V.; Dobrovolskiy, O. V.; Kamchatna, S. N.; Dolgopolova, Ya. V.; Chernovol-Tkachenko, O. A.

    2016-12-01

    The electrical conductivity of hafnium (Hf)-doped YBa2Cu3O7-δ ceramics is investigated. Hf doping has been revealed to lead to an increase of the number of effective scattering centers for the normal charge carriers. In a broad temperature range, the excess conductivity of the investigated samples obeys an exponential temperature dependence, while near Tc it is satisfactorily described by the Aslamazov-Larkin model. Meanwhile, Hf doping has been shown to lead to a notable broadening of the temperature range for the manifestation of the pseudogap anomaly in the ab-plane.

  8. Functional imaging reveals movement preparatory activity in the vegetative state

    Directory of Open Access Journals (Sweden)

    Tristan A Bekinschtein

    2011-01-01

    Full Text Available The Vegetative State (VS is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect residual conscious awareness in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Given that movement preparation in response to a motor command is a sign of purposeful behavior, our results are consistent with residual conscious awareness in these patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.

  9. Mineralocorticoids decrease the activity of the apical small-conductance K channel in the cortical collecting duct.

    Science.gov (United States)

    Wei, Yuan; Babilonia, Elisa; Sterling, Hyacinth; Jin, Yan; Wang, Wen-Hui

    2005-11-01

    We used the patch-clamp technique to examine the effect of DOCA treatment (2 mg/kg) on the apical small-conductance K (SK) channels, epithelial Na channels (ENaC), and the basolateral 18-pS K channels in the cortical collecting duct (CCD). Treatment of rats with DOCA for 6 days significantly decreased the plasma K from 3.8 to 3.1 meq and reduced the activity of the SK channel, defined as NP(o), from 1.3 in the CCD of control rats to 0.6. In contrast, DOCA treatment significantly increased ENaC activity from 0.01 to 0.53 and the basolateral 18-pS K channel activity from 0.67 to 1.63. Moreover, Western blot analysis revealed that DOCA treatment significantly increased the expression of the nonreceptor type of protein tyrosine kinase (PTK), cSrc, and the tyrosine phosphorylation of ROMK in the renal cortex and outer medulla. The possibility that decreases in apical SK channel activity induced by DOCA treatment were the result of stimulation of PTK activity was further supported by experiments in which inhibition of PTK with herbimycin A significantly increased NP(o) from 0.6 to 2.1 in the CCD from rats receiving DOCA. Also, when rats were fed a high-K (10%) diet, DOCA treatment did not increase the expression of c-Src and decrease the activity of the SK channel in the CCD. We conclude that DOCA treatment decreased the apical SK channel activity in rats on a normal-K diet and that an increase in PTK expression may be responsible for decreased channel activity in the CCD from DOCA-treated rats.

  10. Large-conductance voltage- and Ca2+-activated K+ channel regulation by protein kinase C in guinea pig urinary bladder smooth muscle.

    Science.gov (United States)

    Hristov, Kiril L; Smith, Amy C; Parajuli, Shankar P; Malysz, John; Petkov, Georgi V

    2014-03-01

    Large-conductance voltage- and Ca(2+)-activated K(+) (BK) channels are critical regulators of detrusor smooth muscle (DSM) excitability and contractility. PKC modulates the contraction of DSM and BK channel activity in non-DSM cells; however, the cellular mechanism regulating the PKC-BK channel interaction in DSM remains unknown. We provide a novel mechanistic insight into BK channel regulation by PKC in DSM. We used patch-clamp electrophysiology, live-cell Ca(2+) imaging, and functional studies of DSM contractility to elucidate BK channel regulation by PKC at cellular and tissue levels. Voltage-clamp experiments showed that pharmacological activation of PKC with PMA inhibited the spontaneous transient BK currents in native freshly isolated guinea pig DSM cells. Current-clamp recordings revealed that PMA significantly depolarized DSM membrane potential and inhibited the spontaneous transient hyperpolarizations in DSM cells. The PMA inhibitory effects on DSM membrane potential were completely abolished by the selective BK channel inhibitor paxilline. Activation of PKC with PMA did not affect the amplitude of the voltage-step-induced whole cell steady-state BK current or the single BK channel open probability (recorded in cell-attached mode) upon inhibition of all major Ca(2+) sources for BK channel activation with thapsigargin, ryanodine, and nifedipine. PKC activation with PMA elevated intracellular Ca(2+) levels in DSM cells and increased spontaneous phasic and nerve-evoked contractions of DSM isolated strips. Our results support the concept that PKC activation leads to a reduction of BK channel activity in DSM via a Ca(2+)-dependent mechanism, thus increasing DSM contractility.

  11. Interaction between 2 extracellular loops influences the activity of the cystic fibrosis transmembrane conductance regulator chloride channel.

    Science.gov (United States)

    Broadbent, Steven D; Wang, Wuyang; Linsdell, Paul

    2014-10-01

    Activity of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is thought to be controlled by cytoplasmic factors. However, recent evidence has shown that overall channel activity is also influenced by extracellular anions that interact directly with the extracellular loops (ECLs) of the CFTR protein. Very little is known about the structure of the ECLs or how substances interacting with these ECLs might affect CFTR function. We used patch-clamp recording to investigate the accessibility of cysteine-reactive reagents to cysteines introduced throughout ECL1 and 2 key sites in ECL4. Furthermore, interactions between ECL1 and ECL4 were investigated by the formation of disulfide crosslinks between cysteines introduced into these 2 regions. Crosslinks could be formed between R899C (in ECL4) and a number of sites in ECL1 in a manner that was dependent on channel activity, suggesting that the relative orientation of these 2 loops changes on activation. Formation of these crosslinks inhibited channel function, suggesting that relative movement of these ECLs is important to normal channel function. Implications of these findings for the effects of mutations in the ECLs that are associated with cystic fibrosis and interactions with extracellular substances that influence channel activity are discussed.

  12. Understanding Teacher-Student Relationships, Student-Student Relationships, and Conduct Problems in China and the United States

    Science.gov (United States)

    Bear, George G.; Yang, Chunyan; Glutting, Joseph; Huang, Xishan; He, Xianyou; Zhang, Wei; Chen, Dandan

    2014-01-01

    Several previous studies have found that Chinese students perceive teacher-student relationships and student-student relationships more favorably than American students. In this study we examined if the same holds true with respect to teachers' perceptions. Also examined were both students' and teachers' perceptions of conduct problems. The sample…

  13. School Turnaround as National Policy in the United States: Considerations from Three Studies Conducted in the Midwest

    Directory of Open Access Journals (Sweden)

    Coby V. Meyers

    2013-10-01

    Full Text Available School turnaround policy has become prominent in American education discourse. Some federal initiatives specifically target the lowest achieving five percent of schools in the nation, with the goal of bringing schools out of improvement status rapidly. This paper considers and extends the work of three recent studies of school turnaround. Collectively, the studies demonstrate how a strong federal initiative can impact public education on multiple levels, including the state, district, school, and individual levels. School turnaround demonstrates the power of federal initiatives in the United States to impact the public school system at all levels. State departments of education have responded in ways to obtain federal funding. Districts and schools generally with the least capacity to enact change have been challenged with an opportunity to win substantial dollars, but many elected not to compete. Increases in student achievement through such reform appear to be possible, but the human and social costs have yet to be adequately considered.

  14. Instantaneous Intervalley Transition Just at the Franck-Condon State in the Conduction Band of GaAs

    Science.gov (United States)

    Ohnishi, Hiromasa; Tomita, Norikazu; Nasu, Keiichiro

    2016-01-01

    We propose two possible quantum microscopic mechanisms for intervalley transitions just at the Franck-Condon state in GaAs. The first is the simultaneously combined coulombic elastic transitions of two electrons, from the originally photo-excited Γ valley to the mutually opposite L and -L valleys in the Brillouin zone. The second is the "elastic" scattering of an electron from the Γ valley to the L one by the frozen phonon, which is not newly created in the excited state, but already exists, being inherited from the starting ground state, according to the Franck-Condon principle of the photo-excitation. Surprisingly, we can theoretically show that such the elastic electron-phonon scattering gives extremely fast time constant of the order of a few tens femtoseconds, as well as the above elastic electron-electron scattering does.

  15. Activity-dependent depression of excitability and calcium transients in the neurohypophysis suggests a model of "stuttering conduction".

    Science.gov (United States)

    Muschol, Martin; Kosterin, Paul; Ichikawa, Michinori; Salzberg, B M

    2003-12-10

    Using millisecond time-resolved optical recordings of transmembrane voltage and intraterminal calcium, we have determined how activity-dependent changes in the population action potential are related to a concurrent modulation of calcium transients in the neurohypophysis. We find that repetitive stimulation dramatically alters the amplitude of the population action potential and significantly increases its temporal dispersion. The population action potentials and the calcium transients exhibit well correlated frequency-dependent amplitude depression, with broadening of the action potential playing only a limited role. High-speed camera recordings indicate that the magnitude of the spike modulation is uniform throughout the neurohypophysis, thereby excluding propagation failure as the underlying mechanism. In contrast, temporal dispersion and latency of the population spike do increase with distance from the stimulation site. This increase is enhanced during repeated stimulation and by raising the stimulation frequency. Changes in Ca influx directly affect the decline in population spike amplitude, consistent with electrophysiological measurements of the local loss of excitability in nerve terminals and varicosities, mediated by a Ca-activated K conductance. Our observations suggest a model of "stuttering conduction": repeated action potential stimulation causes excitability failures limited to nerve terminals and varicosities, which account for the rapid decline in the population spike amplitude. These failures, however, do not block action potential propagation but generate the cumulative increases in spike latency.

  16. Studies on Electrolyte Conductivity and Activity of Dehydrogenase of Chinese Fir and Masson Pine Bare-Root Seedling under Water and Cold Stress

    Institute of Scientific and Technical Information of China (English)

    Yu Fangyuan; Xu Xizeng; Guo Xinbao

    2003-01-01

    The electrolyte conductivity and activity of dehydrogenase of bare-root seedlings of both Chinese fir (Cunningha-mia lanceolata (Lamb.) Hook.) and Masson pine (Pinus massoniana Lamb.) under freezing and desiccation treatments were studied.The results showed that needle electrolyte conductivity of both species increase significantly after freezing treatment and there are nosignificant differences in needle electrolyte conductivity between the two species. The dehydrogenase activity (ARD) of fine roots ofboth Chinese fir and Masson pine was negatively correlated with increasing freezing and desiccation. The results suggest that bothelectrolyte conductivity and dehydrogenase activity could be used as quick indicators of Chinese fir and Masson pine bare-root seed-ling quality.

  17. The political economy of women’s professional basketball in the United States: A structure-conduct-performance approach

    Directory of Open Access Journals (Sweden)

    Ariel ANTHONY

    2012-11-01

    Full Text Available This study examines the political economy of women’s professional basketball in the United States, including both the American Basketball League (ABL and the Women’s National Basketball Association (WNBA. To do so, we employ the structure-conductperformance paradigm (hereafter SCP from industrial organization. In addition to the importance of television revenues and corporate sponsorships to the success of the leagues, we find evidence of economies of scope, bilateral monopoly issues, and reverse causality in the SCP paradigm as applied to women’s professional basketball in the United States.

  18. Steel passive state stability in activated fly ash mortars

    Directory of Open Access Journals (Sweden)

    Fernández-Jiménez, A.

    2010-12-01

    Full Text Available The present study explores the behaviour of structural steel embedded in Portland cement (OPC mortars and NaOH- and NaOH-waterglass-activated fly ash, in the presence and absence of 2 % Cl- (CaCl2. Variations were determined in the corrosion potential (Ecorr, linear polarization resistance (Rp and corrosion current density (icorr under different environmental conditions (90 days at 95 % relative humidity (RH, 30 days at ≈ 30 % RH, 760 days at ≈ 95 % RH. In the absence of Cl-, fly ash mortars were able to passivate steel reinforcement, although the stability of the passive state in changing environmental conditions was found to depend heavily on the activating solution used. Steel corrosion in the presence of 2 % Cl- was observed to be similar to the corrosion reported for the material in OPC mortars.

    En el presente trabajo se estudia el comportamiento del acero estructural embebido en morteros de cemento Pórtland (OPC y de cenizas volantes activadas con NaOH y una mezcla de NaOH y waterglass, en ausencia y en presencia de un 2% de Cl- (CaCl2. Se determino la evolución del potencial de corrosión (Ecorr, la resistencia de polarización lineal (Rp y la intensidad de corrosión (icorr, variando las condiciones ambientales (90 días al 95% de humedad relativa (HR-30 días a ≈ 30% HR- 760 días a ≈ 95% HR. En ausencia de Cl- los morteros de cenizas volantes activadas pueden pasivar los refuerzos de acero, si bien la estabilidad del estado pasivo ante cambios en las condiciones ambientales parece mostrar una fuerte dependencia de la solución activadora empleada. En presencia de un 2% de Cl- los aceros se corroen mostrando en comportamiento similar al observado en morteros en base OPC.

  19. The Operating Principle of a Fully Solid State Active Magnetic Regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL

    2016-01-01

    As an alternative refrigeration technology, magnetocaloric refrigeration has the potential to be safer, quieter, more efficient, and more environmentally friendly than the conventional vapor compression refrigeration technology. Most of the reported active magnetic regenerator (AMR) systems that operate based on the magnetocaloric effect use heat transfer fluid to exchange heat, which results in complicated mechanical subsystems and components such as rotating valves and hydraulic pumps. This paper presents an operating principle of a fully solid state AMR, in which an alternative mechanism for heat transfer between the AMR and the heat source/sink is proposed. The operating principle of the fully solid state AMR is based on moving rods/sheets (e.g. copper, brass, iron or aluminum), which are employed to replace the heat transfer fluid. Such fully solid state AMR would provide a significantly higher heat transfer rate than a conventional AMR because the conductivity of moving solid rods/plates is high and it enables the increase in the machine operating frequency hence the cooling capacity. The details of operating principle are presented and discussed here. One of the key enabling features for this technology is the contact between the moving rods/sheets and magnetocaloric material, and heat exchange mechanism at the heat source/sink. This paper provides an overview of the design for a fully solid state magnetocaloric refrigeration system along with guidelines for their optimal design.

  20. 30 CFR 285.600 - What plans and information must I submit to MMS before I conduct activities on my lease or grant?

    Science.gov (United States)

    2010-07-01

    ... information must I submit to MMS before I conduct activities on my lease or grant? You must submit a SAP, COP... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What plans and information must I submit to MMS before I conduct activities on my lease or grant? 285.600 Section 285.600 Mineral Resources...

  1. Walker mutations reveal loose relationship between catalytic and channel-gating activities of purified CFTR (cystic fibrosis transmembrane conductance regulator).

    Science.gov (United States)

    Ramjeesingh, M; Li, C; Garami, E; Huan, L J; Galley, K; Wang, Y; Bear, C E

    1999-02-02

    The cystic fibrosis transmembrane conductance regulator (CFTR) functions as an ATPase and as a chloride channel. It has been hypothesized, on the basis of electrophysiological findings, that the catalytic activity of CFTR is tightly coupled to the opening and closing of the channel gate. In the present study, to determine the structural basis for the ATPase activity of CFTR, we assessed the effect of mutations within the "Walker A" consensus motifs on ATP hydrolysis by the purified, intact protein. Mutation of the lysine residue in the "Walker A" motif of either the first nucleotide binding fold (CFTRK464A) or the second nucleotide binding fold (CFTRK1250A) inhibited the ATPase activity of the purified intact CFTR protein significantly, by greater than 50%. This finding suggests that the two nucleotide binding folds of CFTR are functioning cooperatively in catalysis. However, the rate of channel gating was only significantly inhibited in one of these purified mutants, CFTRK1250A, suggesting that ATPase activity may not be tightly coupled to channel gating as previously hypothesized.

  2. Activation of α7 nicotinic receptors by orthosteric and allosteric agonists: influence on single-channel kinetics and conductance.

    Science.gov (United States)

    Pałczyńska, Magda M; Jindrichova, Marie; Gibb, Alasdair J; Millar, Neil S

    2012-11-01

    Nicotinic acetylcholine receptors (nAChRs) are oligomeric transmembrane proteins in which five subunits coassemble to form a central ion channel pore. Conventional agonists, such as acetylcholine (ACh), bind to an orthosteric site, located at subunit interfaces in the extracellular domain. More recently, it has been demonstrated that nAChRs can also be activated by ligands binding to an allosteric transmembrane site. In the case of α7 nAChRs, ACh causes rapid activation and almost complete desensitization. In contrast, allosteric agonists such as 4-(4-bromophenyl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c] quin oline-8-sulfonamide (4BP-TQS) activate α7 nAChRs more slowly and cause only low levels of apparent desensitization. In the present study, single-channel patch-clamp recording has been used to investigate differences in the mechanism of activation of α7 nAChRs by ACh and 4BP-TQS. The most striking difference between activation by ACh and 4BP-TQS is in single-channel kinetics. In comparison with activation by ACh, single-channel open times and burst lengths are substantially longer (~160-800-fold, respectively), and shut times are shorter (~8-fold) when activated by 4BP-TQS. In addition, coapplication of ACh and 4BP-TQS results in a further increase in single-channel burst lengths. Mean burst lengths seen when the two agonists are coapplied (3099 ± 754 ms) are ~2.5-fold longer than with 4BP-TQS alone and ∼370-fold longer than with ACh alone. Intriguingly, the main single-channel conductance of α7 nAChRs, was significantly larger when activated by 4BP-TQS (100.3 ± 2.4 pS) than when activated by ACh (90.0 ± 2.7 pS), providing evidence that activation by allosteric and orthosteric agonists results in different α7 nAChRs open-channel conformations.

  3. A serosurvey for ruminant pestivirus exposure conducted using cattle sera collected for brucellosis surveillance in the United States

    Science.gov (United States)

    Four species of ruminant pestivirus are currently circulating in the United States (U.S.): Bovine viral diarrhea virus (BVDV) types 1 and 2 (predominant host cattle), Border disease virus (BDV) (predominant host sheep) and the Pronghorn virus (sporadically detected in wild ruminants). A third bovin...

  4. 20 CFR 631.41 - Allowable State activities.

    Science.gov (United States)

    2010-04-01

    ...) States may use funds reserved under § 631.32(c) of this part, subject to the provisions of the State... than basic and remedial education, literacy and English for non-English speakers training,...

  5. Aeroelastic code development activities in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A.D. [National Renewable Energy Lab., Golden, Colorado (United States)

    1996-09-01

    Designing wind turbines to be fatigue resistant and to have long lifetimes at minimal cost is a major goal of the federal wind program and the wind industry in the United States. To achieve this goal, we must be able to predict critical loads for a wide variety of different wind turbines operating under extreme conditions. The codes used for wind turbine dynamic analysis must be able to analyze a wide range of different wind turbine configurations as well as rapidly predict the loads due to turbulent wind inflow with a minimal set of degrees of freedom. Code development activities in the US have taken a two-pronged approach in order to satisfy both of these criteria: (1) development of a multi-purpose code which can be used to analyze a wide variety of wind turbine configurations without having to develop new equations of motion with each configuration change, and (2) development of specialized codes with minimal sets of specific degrees of freedom for analysis of two- and three-bladed horizontal axis wind turbines and calculation of machine loads due to turbulent inflow. In the first method we have adapted a commercial multi-body dynamics simulation package for wind turbine analysis. In the second approach we are developing specialized codes with limited degrees of freedom, usually specified in the modal domain. This paper will summarize progress to date in the development, validation, and application of these codes. (au) 13 refs.

  6. Enhancing proton conduction in 2D Co-La coordination frameworks by solid-state phase transition.

    Science.gov (United States)

    Bao, Song-Song; Otsubo, Kazuya; Taylor, Jared M; Jiang, Zheng; Zheng, Li-Min; Kitagawa, Hiroshi

    2014-07-02

    We report that a new 2D 3d-4f phosphonate [Co(III)La(III)(notpH)(H2O)6]ClO4·5H2O (CoLa-II) can undergo a phase transition above 45 °C and 93% relative humidity, resulting in [H3O][CoLa(notp)(H2O)4]ClO4·3H2O (CoLa-III). The transition is accompanied by the release of the proton from intralayer to interlayer, and thus the proton conductivity of the material is increased by 1 order of magnitude.

  7. The assessment of activities conducted by companies in social media in light of research concerning their users

    Directory of Open Access Journals (Sweden)

    Bogdan Gregor

    2014-12-01

    Full Text Available Social media are not losing their popularity. Despite their long (sometimes a few years long presence on the Internet, portals from this category are gradually strengthening their position with regard to the number of registered users. In July 2014 the biggest social media portal – Facebook – had 1,320,000,000 active accounts around the whole world. In Poland in July 2014 the number of active users of the portal reached 12,000,000. In the period from April 12 to May 25, 2014, the Department of Marketing of the Faculty of Management of University of Lodz conducted a research aimed at the assessment of activities conducted by companies in social media. The goal of the research was to reach people using social media and investigate how particular measures taken by companies in social media are assessed by them, as well as to identify which of these actions boost engagement and influence making a purchasing decision. In course of the research the method of Internet questionnaire was applied. 302 respondents took part in the survey and almost 90% of them declared that they use social media portals. The most popular social network among the respondents is Facebook. YouTube also plays a major role. This may be seen as evidence that the marketing potential of video contents published on the Internet is huge. The conducted research shows that among the biggest benefits associated with having an account on a social media portal is the possibility of fast communication, chance to find and follow friends, as well as accumulation of the most important information in one place. Over 70% of the surveyed follows well-known companies and brands in social media. Fashion brands and brands associated with the food and electronics branches are followed most often. What the respondents most often named as one of the advantages of following brands in social media is the possibility of continuously following novelties, opportunity to receive discount coupons, as

  8. Mitochondrial uncoupler FCCP activates proton conductance but does not block store-operated Ca(2+) current in liver cells.

    Science.gov (United States)

    To, Minh-Son; Aromataris, Edoardo C; Castro, Joel; Roberts, Michael L; Barritt, Greg J; Rychkov, Grigori Y

    2010-03-15

    Uncouplers of mitochondrial oxidative phosphorylation, including carbonilcyanide p-triflouromethoxyphenylhydrazone (FCCP) and carbonilcyanide m-cholorophenylhydrazone (CCCP), are widely used in experimental research to investigate the role of mitochondria in cellular function. Unfortunately, it is very difficult to interpret the results obtained in intact cells using FCCP and CCCP, as these agents not only inhibit mitochondrial potential, but may also affect membrane potential and cell volume. Here we show by whole-cell patch clamping that in primary rat hepatocytes and H4IIE liver cells, FCCP induced large proton currents across the plasma membrane, but did not activate any other observable conductance. In intact hepatocytes FCCP inhibits thapsigargin-activated store-operated Ca(2+) entry, but in patch clamping under the conditions of strong Ca(2+) buffering it has no effect on store-operated Ca(2+) current (I(SOC)). These results indicate that there is no direct connection between mitochondria and activation of I(SOC) in liver cells and support the notion of indirect regulation of I(SOC) by mitochondrial Ca(2+) buffering.

  9. Developmental mapping of small-conductance calcium-activated potassium channel expression in the rat nervous system.

    Science.gov (United States)

    Gymnopoulos, Marco; Cingolani, Lorenzo A; Pedarzani, Paola; Stocker, Martin

    2014-04-01

    Early electrical activity and calcium influx regulate crucial aspects of neuronal development. Small-conductance calcium-activated potassium (SK) channels regulate action potential firing and shape calcium influx through feedback regulation in mature neurons. These functions, observed in the adult nervous system, make them ideal candidates to regulate activity- and calcium-dependent processes in neurodevelopment. However, to date little is known about the onset of expression and regions expressing SK channel subunits in the embryonic and postnatal development of the central nervous system (CNS). To allow studies on the contribution of SK channels to different phases of development of single neurons and networks, we have performed a detailed in situ hybridization mapping study, providing comprehensive distribution profiles of all three SK subunits (SK1, SK2, and SK3) in the rat CNS during embryonic and postnatal development. SK channel transcripts are expressed at early stages of prenatal CNS development. The three SK channel subunits display different developmental expression gradients in distinct CNS regions, with time points of expression and up- or downregulation that can be associated with a range of diverse developmental events. Their early expression in embryonic development suggests an involvement of SK channels in the regulation of developmental processes. Additionally, this study shows how the postnatal ontogenetic patterns lead to the adult expression map for each SK channel subunit and how their coexpression in the same regions or neurons varies throughout development.

  10. Inhibition of phosphatidylinositol 3-kinase stimulates activity of the small-conductance K channel in the CCD.

    Science.gov (United States)

    Li, Dimin; Wei, Yuan; Babilonia, Elisa; Wang, Zhijian; Wang, Wen-Hui

    2006-04-01

    We used Western blotting to examine the expression of phosphatidylinositol 3-kinase (PI3K) in the renal cortex and outer medulla and employed the patch-clamp technique to study the effect of PI3K on the ROMK-like small-conductance K (SK) channels in the cortical collecting duct (CCD). Low K intake increased the expression of the 110-kDa alpha-subunit (p110alpha) of PI3K compared with rats on a normal-K diet. Because low K intake increases superoxide levels (2), the possibility that increases in superoxide anions may be responsible for the effect of low K intake on the expression of PI3K is supported by finding that addition of H(2)O(2) stimulates the expression of p110alpha in M1 cells. Inhibition of PI3K with either wortmannin or LY-294002 significantly increased channel activity in the CCD from rats on a K-deficient (KD) diet or on a normal-K diet. The stimulatory effect of wortmannin on ROMK channel activity cannot be mimicked by inhibition of phospholipase C with U-73122. This suggests that the effect of inhibiting PI3K was not the result of increasing the phosphatidylinositol 4,5-bisphosphate level. Moreover, application of the exogenous phosphatidylinositol 3,4,5-trisphosphate analog had no effect on channel activity in excised patches. Because low K intake has been shown to increase the activity of protein tyrosine kinase (PTK), we explored the role of the interaction between PTK and PI3K in the regulation of the SK channel activity. Inhibition of PTK increased SK channel activity in the CCD from rats on a KD diet. However, addition of wortmannin did not further increase ROMK channel activity. Also, the effect of wortmannin was abolished by treatment of CCD with phalloidin. We conclude that PI3K is involved in mediating the effect of low K intake on ROMK channel activity in the CCD and that the effect of PI3K on SK channels requires the involvement of PTK and the cytoskeleton.

  11. Summary of activities of the life cycle costing workshop conducted by the Environmental Restoration Program of Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    A five-day life cycle workshop was conducted by the Environmental Restoration (FR) Program of Oak Ridge National Laboratory (ORNL) to develop appropriate remediation scenarios for each Waste Area Grouping (WAG) at ORNL and to identify associated data needs (e.g., remedial investigations, special studies, and technology demonstrations) and required interfaces. Workshop participants represented the Department of Energy, Martin Marietta Energy Systems, Inc., Bechtel National, Radian Corporation, EBASCO Corporation, and M-K Ferguson. The workshop was used to establish a technical basis for remediation activities at each WAG. The workshop results are documented in this report and provide the baseline for estimating the technical scope for each WAG. The scope and associated budgets and schedules will be summarized in baseline reports for each WAG, which, in turn, will be compiled into an overall strategy document for ORNL ER.

  12. Thermal conductivity of carbon doped GeTe thin films in amorphous and crystalline state measured by modulated photo thermal radiometry

    Science.gov (United States)

    Kusiak, Andrzej; Battaglia, Jean-Luc; Noé, Pierre; Sousa, Véronique; Fillot, F.

    2016-09-01

    The thermal conductivity and thermal boundary resistance of GeTe and carbon doped GeTe thin films, designed for phase change memory (PCM) applications, were investigated by modulated photo thermal radiometry. It was found that C doping has no significant effect on the thermal conductivity of these chalcogenides in amorphous state. The thermal boundary resistance between the amorphous films and SiO2 substrate is also not affected by C doping. The films were then crystallized by an annealing at 450°C as confirmed by optical reflectivity analysis. The thermal conductivity of non-doped GeTe significantly increases after crystallization annealing. But, surprisingly the thermal conductivity of the crystallized C doped GeTe was found to be similar from that of the amorphous state and independent of C concentration. As for the amorphous phase, C doping does not affect the thermal boundary resistance between the crystalline GeTe films and SiO2 substrate. This behaviour is discussed thanks to XRD and FTIR analysis. In particular, XRD shows a decrease of crystalline grain size in crystalline films as C concentration is increased. FTIR analysis of the film before and after crystallization evidenced that this evolution could be attributed to the disappearing of Ge-C bonds and migration of C atoms out of the GeTe phase upon crystallization, limiting then the growth of GeTe crystallites in C-doped films.

  13. INFLUENCE OF BIOLOGICALLY ACTIVE AGENTS ON A STRUCTURAL STATE AND THE ENZYMATIC ACTIVITY OF BLACK ORDINARY CARBONATED SOIL

    Directory of Open Access Journals (Sweden)

    Lychman V. A.

    2014-04-01

    Full Text Available The results of a long-term research of the influence of various biologically active agents (a humic preparation Lignogumat and microbiological Baikal EM fertilizer on a structural state and the enzymatic activity of ordinary carbonated black soil are presented. It has been established that biologically active substances contribute to increased enzymatic activity, humus and improve the soil structure

  14. Increased skin conductance responses and neural activity during fear conditioning are associated with a repressive coping style

    Directory of Open Access Journals (Sweden)

    Tim eKlucken

    2015-06-01

    Full Text Available The investigation of individual differences in coping styles in response to fear conditioning is an important issue for a better understanding of the etiology and treatment of psychiatric disorders. It has been assumed that an avoidant (repressive coping style is characterized by increased emotion regulation efforts in context of fearful stimuli as compared to a more vigilant coping style. However, no study so far has investigated the neural correlates of fear conditioning of repressors and sensitizers.In the present fMRI study, 76 participants were classified as repressors or as sensitizers and were exposed to a fear conditioning paradigm, in which the CS+ predicted electrical stimulation, while another neutral stimulus (CS- did not. In addition, skin conductance responses (SCRs were measured continuously.As the main findings, we found increased neural activations in repressors as compared to sensitizers in the ventromedial prefrontal cortex and the anterior cingulate cortex during fear conditioning. In addition, elevated activity to the CS+ in amygdala, insula, occipital, and orbitofrontal cortex as well as conditioned SCRs were found in repressors.The present results demonstrate increased neural activations in structures linked to emotion down-regulation mechanisms like the ventromedial prefrontal cortex, which may reflect the increased coping effort in repressors. At the same time, repressors showed increased activations in arousal and evaluation-associated structures like the amygdala, the occipital cortex, and the orbitofrontal cortex, which is also mirrored in increased SCRs. The present results support recent assumptions about a two-process model of repression postulating a fast vigilant response to fearful stimuli, but also a second emotion down-regulating process.

  15. ACHIEVING PAKIS’S THERMAL CONDUCTIVITY AS ARCHITECTURAL BUILDING THERMAL RESISTANT BY GUARDED STEADY-STATE HOTBOX METHOD:PART 1

    Directory of Open Access Journals (Sweden)

    Danny Santoso Mintorogo

    2011-01-01

    Full Text Available Thermal conductivity of various materials which are mostly listed available as building or industrial materials in reference books and websites; but one will hardly find out for every new material, and has to be observed and try out itself if we want to know the new thermal conductivity value (k. Nonetheless with new substanct likes pakis-stem blocks that come from natural tree that could be found in the tropical woodland of Indonesia. Steady-state homogeneous temperature applied with hotbox method in an uninfluent environment likes guarded laboratory environment is the right method to obtain the thermal conductivity and resistance of porousness and semi-solidness of the pakis-stem blocks. After investigating almost 24 hours with controller TRSYS01 applying with ASTM C1155, physical semi-solid pakis blocks tend to be more easy to obtain the R-value, k-value, and surface temperatures than the porous pakis. The porous pakis blocks were tend to unstable during the test due to its physical permeable condition. The resistant values (R-value and thermal conductivity (k values will be further published on the following discussion of pakis thermal conductivity part 2.

  16. The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I.; Stam, C.; Douw, L.; Bartolomei, F.; Heimans, J.; Dijk, van B.; Postma, T.; Klein, M.; Reijneveld, J.

    2008-01-01

    Purpose: In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activ

  17. The influence of low-grade glioma on resting state oscillatory brain activity : a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I; Stam, C J; Douw, L; Bartolomei, F; Heimans, J J; van Dijk, B W; Postma, T J; Klein, M; Reijneveld, J C

    2008-01-01

    PURPOSE: In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activ

  18. Muscle fiber conduction velocity and fractal dimension of EMG during fatiguing contraction of young and elderly active men.

    Science.gov (United States)

    Boccia, Gennaro; Dardanello, Davide; Beretta-Piccoli, Matteo; Cescon, Corrado; Coratella, Giuseppe; Rinaldo, Nicoletta; Barbero, Marco; Lanza, Massimo; Schena, Federico; Rainoldi, Alberto

    2016-01-01

    Over the past decade, linear and nonlinear surface electromyography (EMG) variables highlighting different components of fatigue have been developed. In this study, we tested fractal dimension (FD) and conduction velocity (CV) rate of changes as descriptors, respectively, of motor unit synchronization and peripheral manifestations of fatigue. Sixteen elderly (69  ±  4 years) and seventeen young (23  ±  2 years) physically active men (almost 3-5 h of physical activity per week) executed one knee extensor contraction at 70% of a maximal voluntary contraction for 30 s. Muscle fiber CV and FD were calculated from the multichannel surface EMG signal recorded from the vastus lateralis and medialis muscles. The main findings were that the two groups showed a similar rate of change of CV, whereas FD rate of change was higher in the young than in the elderly group. The trends were the same for both muscles. CV findings highlighted a non-different extent of peripheral manifestations of fatigue between groups. Nevertheless, FD rate of change was found to be steeper in the elderly than in the young, suggesting a greater increase in motor unit synchronization with ageing. These findings suggest that FD analysis could be used as a complementary variable providing further information on central mechanisms with respect to CV in fatiguing contractions.

  19. State support as factor of increase of innovative activity of industrial enterprises

    Directory of Open Access Journals (Sweden)

    N.N. Bondarenko

    2011-10-01

    Full Text Available The article is devoted research of factors of increase of innovative activity of enterprise, the indexes of innovative activity of industrial enterprises are analysed in Ukraine, the necessity of creation of attractive terms is grounded for development of innovative activity and increase of innovative activity of management subjects at state level, the forms of state support as factor of increase of innovative activity of industrial enterprises are considered.

  20. Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature

    Science.gov (United States)

    Yang, Chih-Ping; Chen, Hsiao-Chien; Wang, Ching-Chiung; Tsai, Po-Wei; Ho, Chia-Wen; Liu, Yu-Chuan

    2015-12-01

    Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water’s tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water’s fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte’s concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4’-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water’s fundamental activities via effective energy transfer.

  1. S-acylation dependent post-translational cross-talk regulates large conductance calcium- and voltage- activated potassium (BK channels

    Directory of Open Access Journals (Sweden)

    Michael J Shipston

    2014-08-01

    Full Text Available Mechanisms that control surface expression and/or activity of large conductance calcium-activated potassium (BK channels are important determinants of their (pathophysiological function. Indeed, BK channel dysfunction is associated with major human disorders ranging from epilepsy to hypertension and obesity. S-acylation (S-palmitoylation represents a major reversible, post-translational modification controlling the properties and function of many proteins including ion channels. Recent evidence reveals that both pore-forming and regulatory subunits of BK channels are S-acylated and control channel trafficking and regulation by AGC-family protein kinases. The pore-forming α-subunit is S-acylated at two distinct sites within the N- and C-terminus, each site being regulated by different palmitoyl acyl transferases (zDHHCs and acyl thioesterases. (APTs. S-acylation of the N-terminus controls channel trafficking and surface expression whereas S-acylation of the C-terminal domain determines regulation of channel activity by AGC-family protein kinases. S-acylation of the regulatory β4-subunit controls ER exit and surface expression of BK channels but does not affect ion channel kinetics at the plasma membrane. Furthermore, a significant number of previously identified BK-channel interacting proteins have been shown, or are predicted to be, S-acylated. Thus, the BK channel multi-molecular signalling complex may be dynamically regulated by this fundamental post-translational modification and thus S-acylation likely represents an important determinant of BK channel physiology in health and disease.

  2. Small conductance Ca2+-activated K+ channels regulate firing properties and excitability in parasympathetic cardiac motoneurons in the nucleus ambiguus.

    Science.gov (United States)

    Lin, Min; Hatcher, Jeff T; Chen, Qin-Hui; Wurster, Robert D; Cheng, Zixi Jack

    2010-12-01

    Small conductance Ca(2+)-activated K(+) channels (SK) regulate action potential (AP) firing properties and excitability in many central neurons. However, the functional roles of SK channels of parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus have not yet been well characterized. In this study, the tracer X-rhodamine-5 (and 6)-isothiocyanate (XRITC) was injected into the pericardial sac to retrogradely label PCMNs in FVB mice at postnatal days 7-9. Two days later, XRITC-labeled PCMNs in brain stem slices were identified. With the use of whole cell current clamp, single APs and spike trains of different frequencies were evoked by current injections. We found that 1) PCMNs have two different firing patterns: the majority of PCMNs (90%) exhibited spike frequency adaptation (SFA) and the rest (10%) showed less or no adaptation; 2) application of the specific SK channel blocker apamin significantly increased spike half-width in single APs and trains and reduced the spike frequency-dependent AP broadening in trains; 3) SK channel blockade suppressed afterhyperpolarization (AHP) amplitude following single APs and trains and abolished spike-frequency dependence of AHP in trains; and 4) SK channel blockade increased the spike frequency but did not alter the pattern of SFA. Using whole cell voltage clamp, we measured outward currents and afterhyperpolarization current (I(AHP)). SK channel blockade revealed that SK-mediated outward currents had both transient and persistent components. After bath application of apamin and Ca(2+)-free solution, we found that apamin-sensitive and Ca(2+)-sensitive I(AHP) were comparable, confirming that SK channels may contribute to a major portion of Ca(2+)-activated K(+) channel-mediated I(AHP). These results suggest that PCMNs have SK channels that significantly regulate AP repolarization, AHP, and spike frequency but do not affect SFA. We conclude that activation of SK channels underlies one of the mechanisms for negative

  3. ANALYTICAL PLANS SUPPORTING THE SWPF GAP ANALYSIS BEING CONDUCTED WITH ENERGYSOLUTIONS AND THE VITREOUS STATE LABORATORY AT THE CUA

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.; Peeler, D.

    2014-10-28

    EnergySolutions (ES) and its partner, the Vitreous State Laboratory (VSL) of The Catholic University of America (CUA), are to provide engineering and technical services support to Savannah River Remediation, LLC (SRR) for ongoing operation of the Defense Waste Processing Facility (DWPF) flowsheet as well as for modifications to improve overall plant performance. SRR has requested that the glass formulation team of Savannah River National Laboratory (SRNL) and ES-VSL develop a technical basis that validates the current Product Composition Control System models for use during the processing of the coupled flowsheet or that leads to the refinements of or modifications to the models that are needed so that they may be used during the processing of the coupled flowsheet. SRNL has developed a matrix of test glasses that are to be batched and fabricated by ES-VSL as part of this effort. This document provides two analytical plans for use by ES-VSL: one plan is to guide the measurement of the chemical composition of the study glasses while the second is to guide the measurement of the durability of the study glasses based upon the results of testing by ASTM’s Product Consistency Test (PCT) Method A.

  4. Densely-packed graphene/conducting polymer nanoparticle papers for high-volumetric-performance flexible all-solid-state supercapacitors

    Science.gov (United States)

    Yang, Chao; Zhang, Liling; Hu, Nantao; Yang, Zhi; Wei, Hao; Xu, Zhichuan J.; Wang, Yanyan; Zhang, Yafei

    2016-08-01

    Graphene-based all-solid-state supercapacitors (ASSSCs) are one of the most ideal candidates for high-performance flexible power sources. The achievement of high volumetric energy density is highly desired for practical application of this type of ASSSCs. Here, we present a facile method to boost volumetric performances of graphene-based flexible ASSSCs through incorporation of ultrafine polyaniline-poly(4-styrenesulfonate) (PANI-PSS) nanoparticles in reduced graphene oxide (rGO) papers. A compact structure is obtained via intimate contact and π-π interaction between PANI-PSS nanoparticles and rGO sheets. The hybrid paper electrode with the film thickness of 13.5 μm, shows an extremely high volumetric specific capacitance of 272 F/cm3 (0.37 A/cm3 in a three-electrode cell). The assembled ASSSCs show a large volumetric specific capacitance of 217 F/cm3 (0.37 A/cm3 in a two-electrode cell), high volumetric energy and power density, excellent capacitance stability, small leakage current as well as low self-discharge characteristics, revealing the usefulness of this robust hybrid paper for high-performance flexible energy storage devices.

  5. Human endogenous retrovirus W family envelope gene activates the small conductance Ca2+-activated K+ channel in human neuroblastoma cells through CREB.

    Science.gov (United States)

    Li, S; Liu, Z C; Yin, S J; Chen, Y T; Yu, H L; Zeng, J; Zhang, Q; Zhu, F

    2013-09-05

    Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. Using a luciferase reporter system and RNA interference method, we found that functional cAMP response element site was required for the expression of SK3 triggered by HERV-W env. In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.

  6. Enhancement of lithium ion conductivity by doping Li3BO3 in Li2S-P2S5 glass-ceramics electrolytes for all-solid-state batteries

    Science.gov (United States)

    Eom, Minyong; Choi, Sunho; Son, Seunghyeon; Choi, Lakyoung; Park, Chanhwi; Shin, Dongwook

    2016-11-01

    (100-x) (0.78Li2S·0.22P2S5)·xLi3BO3 (0 ≤ x ≤ 5) solid electrolytes are prepared via mechanical milling and a post heat-treatment process, and the resulting electrochemical properties are investigated in conjunction with structural analysis. Adding of Li3BO3 into the (100-x) (0.78Li2S·0.22P2S5)·xLi3BO3 solid electrolyte is expected to enhance the conductivity and lower the activation energy as a consequence of changing the structural unit in the glass network. It turned out that the doping of Li3BO3 enhances the conductivity by enlarging the glass forming region and promoting precipitation of high lithium ion conductive thio-LISICON II analog. 97 (0.78Li2S·0.22P2S5)·3Li3BO3 (x = 3) glass-ceramics exhibits the highest conductivity (1.03 × 10-3 S cm-1). Structural analysis shows that the samples with Li3BO3 added to the electrolyte are composed of the main structural unit of PS43- with partially-modified structural unit of PO43-, which are believed to effectively enhance the conductivity and decrease the activation energy. In glass-ceramics produced from these materials, the thio-LISICON II phase with higher ionic conductivity tends to be stabilized by the addition of Li3BO3. Additionally, the formation of space-charge layer is relaxed by Li3BO3 doping. As a result, the all-solid-state cell shows high initial discharge capacity of 156 mAh g-1, and the capacity is retained to be 149 mAh g-1 for 40 cycles.

  7. Time-resolved terahertz spectroscopy of electrically conductive metal-organic frameworks doped with redox active species

    Science.gov (United States)

    Alberding, Brian G.; Heilweil, Edwin J.

    2015-09-01

    Metal-Organic Frameworks (MOFs) are three-dimensional coordination polymers that are well known for large pore surface area and their ability to adsorb molecules from both the gaseous and solution phases. In general, MOFs are electrically insulating, but promising opportunities for tuning the electronic structure exist because MOFs possess synthetic versatility; the metal and organic ligand subunits can be exchanged or dopant molecules can be introduced into the pore space. Two such MOFs with demonstrated electrical conductivity are Cu3(1,3,5-benzenetricarboxylate)2, a.k.a HKUST-1, and Cu[Ni(pyrazine-2,3-dithiolate)2]. Herein, these two MOFs have been infiltrated with the redox active species 7,7,8,8-tetracyanoquinodimethane (TCNQ) and iodine under solution phase conditions and shown to produce redox products within the MOF pore space. Vibrational bands assignable to TCNQ anion and triiodide anion have been observed in the Mid-IR and Terahertz ranges using FTIR Spectroscopy. The MOF samples have been further investigated by Time-Resolved Terehertz Spectroscopy (TRTS). Using this technique, the charge mobility, separation, and recombination dynamics have been followed on the picosecond time scale following photoexcitation with visible radiation. The preliminary results show that the MOF samples have small inherent photoconductivity with charge separation lifetimes on the order of a few picoseconds. In the case of HKUST-1, the MOF can also be supported by a TiO2 film and initial results show that charge injection into the TiO2 layer occurs with a comparable efficiency to the dye sensitizer N3, [cis-Bis(isothiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylato ruthenium(II)], and therefore this MOF has potential as a new light absorbing and charge conducting material in photovoltaic devices.

  8. Improvement of ionic conductivity and performance of quasi-solid-state dye sensitized solar cell using PEO/PMMA gel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Aram, E. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Ehsani, M., E-mail: m.ehsani@ippi.ac.ir [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Khonakdar, H.A. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Leibniz Institute of Polymer Research, D-01067 Dresden (Germany)

    2015-09-10

    Graphical abstract: Reduced interfacial resistance of a quasi-solid-state dye sensitized solar cell with PEO/PMMA blend gel electrolytes. - Highlights: • A new polymer gel electrolyte containing PEO/PMMA was developed for DSSCs. • Optimization of polymer gel electrolyte was done for dye sensitized solar cell. • The best ionic conductivity was found in PEO/PMMA blend with 10/90 w/w composition. • The DSSC with the PEO/PMMA based electrolyte showed good photovoltaic performance. • Significant stability improvement for quasi-solid state DSSC was obtained. - Abstract: Polymer blend gel electrolytes based on polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) as host polymers with various weight ratios, LiI/I{sub 2} as redox couple in electrolyte and 4-tert-butyl pyridine as additive were prepared by solution method. The introduction of PMMA in the PEO gel electrolyte reduced the degree of crystallinity of PEO, which was confirmed by differential scanning calorimetry (DSC). Complexation and ionic conductivity as a function of temperature were investigated with Fourier transform infrared and ionic conductometry, respectively. A good correlation was found between the degree of crystallinity and ionic conductivity. The reduction in crystallinity, governed by blending ratio, led to improvement of ionic conductivity. The best ionic conductivity was attained in PEO/PMMA blend with 10/90 w/w composition. The performance of a quasi-solid-state dye sensitized solar cell using the optimized polymer gel electrolyte was investigated. The optimized system of high ionic conductivity of 7 mS cm{sup −1}, with fill factor of 0.59, short-circuit density of 11.11 mA cm{sup −2}, open-circuit voltage of 0.75 V and the conversion efficiency of 4.9% under air mass 1.5 irradiation (100 mW cm{sup −2}) was obtained. The long-term stability of the dye-sensitized solar cell (DSSC) during 600 h was improved by using PEO/PMMA gel electrolyte relative to a liquid type

  9. Terahertz and direct current losses and the origin of non-Drude terahertz conductivity in the crystalline states of phase change materials

    Science.gov (United States)

    Shimakawa, Koichi; Wagner, Tomas; Frumar, Miloslav; Kadlec, Filip; Kadlec, Christelle; Kasap, Safa

    2013-12-01

    THz and DC losses in crystalline states of GeSbTe and AgInSbTe phase-change material systems are re-examined and discussed. Although a simple free carrier transport has been assumed so far in the GeSbTe (GST) system, it is shown through recent experimental results that a series sequence of intragrain and intergrain (tunneling) transport, as recently formulated in Shimakawa et al., "The origin of non-Drude terahertz conductivity in nanomaterials," Appl. Phys. Lett. 100, 132102 (2012) may dominate the electronic transport in the commercially utilized GST system, producing a non-Drude THz conductivity. The extracted physical parameters such as the free-carrier density and mobility are significantly different from those obtained from the Drude law. These physical parameters are consistent with those obtained from the DC loss data, and provide further support for the model. Negative temperature coefficient of resistivity is found even in the metallic state, similar to amorphous metals, when the mean free path is short. It is shown that the concept of minimum metallic conductivity, often used in the metal-insulator transition, cannot be applied to electronic transport in these materials.

  10. Terahertz and direct current losses and the origin of non-Drude terahertz conductivity in the crystalline states of phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Shimakawa, Koichi [Department of General and Inorganic Chemistry, University of Pardubice, Pardubice (Czech Republic); Department of Electrical Engineering, Gifu University (Japan); Wagner, Tomas; Frumar, Miloslav [Department of General and Inorganic Chemistry, University of Pardubice, Pardubice (Czech Republic); Kadlec, Filip; Kadlec, Christelle [Institute of Physics, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kasap, Safa [Department of Electrical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

    2013-12-21

    THz and DC losses in crystalline states of GeSbTe and AgInSbTe phase-change material systems are re-examined and discussed. Although a simple free carrier transport has been assumed so far in the GeSbTe (GST) system, it is shown through recent experimental results that a series sequence of intragrain and intergrain (tunneling) transport, as recently formulated in Shimakawa et al., “The origin of non-Drude terahertz conductivity in nanomaterials,” Appl. Phys. Lett. 100, 132102 (2012) may dominate the electronic transport in the commercially utilized GST system, producing a non-Drude THz conductivity. The extracted physical parameters such as the free-carrier density and mobility are significantly different from those obtained from the Drude law. These physical parameters are consistent with those obtained from the DC loss data, and provide further support for the model. Negative temperature coefficient of resistivity is found even in the metallic state, similar to amorphous metals, when the mean free path is short. It is shown that the concept of minimum metallic conductivity, often used in the metal-insulator transition, cannot be applied to electronic transport in these materials.

  11. Characterization and Evaluation of 600 V Range Devices for Active Power Factor Correction in Boundary and Continuous Conduction Modes

    DEFF Research Database (Denmark)

    Hernandez Botella, Juan Carlos; Petersen, Lars Press; Andersen, Michael A. E.

    2015-01-01

    Traditional characterization of semiconductors switching dynamics is performed based on clamped inductive load measurements using the double pulse tester (DPT) configuration. This approach is valid for converters operating in continuous conduction mode (CCM), however in boundary conduction mode...

  12. Thermal degradation kinetics and solid state, temperature dependent, electrical conductivity of charge–transfer complex of phenothiazine with chloranil and picric acid

    Indian Academy of Sciences (India)

    M A Ashok; B N Achar

    2008-02-01

    Temperature dependent electrical conductivity and thermal degradation kinetics of charge–transfer (C–T) complexes of phenothiazine (PTZ) with -chloranil (CHL) and picric acid (PA), are reported. These C–T complexes exhibited semiconducting behaviour. The activation energies for PTZ–CHL and PTZ–PA complexes are calculated based on their electrical conductivities measured over the temperature ranges 30–110°C and 30–90°C, respectively. And these energies for PTZ–CHL and PTZ–PA are 0.54 eV and 0.75 eV, respectively. The complexes are analysed for the kinetic parameters like the activation energy for decomposition and the Arrhenius pre-exponential factors in their pyrolysis region using Broido’s, Coats–Redfern as well as Horowitz–Metzger methods. Using standard equations, thermodynamic parameters such as enthalpy, entropy and free energies, are calculated.

  13. Research on plant-parasitic nematode biology conducted by the United States Department of Agriculture-Agricultural Research Service.

    Science.gov (United States)

    Chitwood, David J

    2003-01-01

    The recent de-registration of several chemical nematicides and the impending loss of methyl bromide from the pest-control market necessitate the development of new methods for controlling nematode-induced crop damage. One approach for developing novel target-specific controls is by exploiting fundamental differences between the biological processes of nematodes and their host plants. Researchers of the Agricultural Research Service (ARS) of the US Department of Agriculture are actively exploring these differences. Research accomplishments include the discovery of heat shock protein genes possibly involved in developmental arrest of the soybean cyst nematode, the identification of neuropeptides and female-specific proteins in the soybean cyst nematode, the disruption of nematode reproduction with inhibitors of nematode sterol metabolism, the development of novel morphological and molecular (heat shock protein genes and the D3 segment of large subunit ribosomal DNA) features useful for nematode identification and classification, and the elucidation of the population genetics of potato cyst nematode pathotypes. In addition, several ARS researchers are investigating biological determinants of nematode response to management strategies utilized in agricultural fields. These collective efforts should lead to new chemical and non-chemical alternatives to conventional nematode control strategies.

  14. State activities that promote fuel cell and hydrogen infrastructure development

    Energy Technology Data Exchange (ETDEWEB)

    Gangi, J. [Fuel Cells 2000, Washington, DC (United States). Breakthrough Technologies Inst.

    2007-07-01

    The fuel cell and hydrogen industry provide environmental benefits in addition to economic benefits in the form of jobs and business. This presentation outlined the initiatives, policy and partnerships that individual states are initiating to promote the commercialization of fuel cells and hydrogen fuels. Multi-state partnerships and regional organizations and initiatives were highlighted along with state programs, regulations, demonstrations and incentives that include hydrogen, fuel cells and zero emission vehicles. It was shown that 47 states and the District of Columbia (DC) are involved in the promotion of fuel cell or hydrogen legislation and funding. Breakthrough Technologies Institute, the parent organization of Fuel Cells 2000, and the U.S. Department of Energy's Hydrogen Program has launched a searchable database that catalogues all stationary installations, hydrogen fueling stations and vehicle demonstration programs in the United States, including cars, buses and specialty vehicles. The database is intended to be a guide for local, state and federal lawmakers to implement similar legislation and initiatives in their jurisdictions. The database includes regulations such as interconnection standards, renewable portfolio standards and net metering as well as legislation such as tax credits, grants, and loans. Roadmaps and funding/support for business incubators and relocation are included. The database is also an important tool for the general public who are trying to learn more about the technology. Although federal research money has mainly focused on transportation and related fuel technologies, individual states are targeting other applications and areas such as materials and components, stationary power and fuel storage.

  15. Measurement of the topological surface state optical conductance in bulk-insulating Sn-doped Bi1.1Sb0.9Te2S single crystals

    Science.gov (United States)

    Cheng, Bing; Wu, Liang; Kushwaha, S. K.; Cava, R. J.; Armitage, N. P.

    2016-11-01

    Topological surface states have been extensively observed via optics in thin films of topological insulators. However, in typical thick single crystals of these materials, bulk states are dominant and it is difficult for optics to verify the existence of topological surface states definitively. In this Rapid Communication, we study the charge dynamics of the newly formulated bulk-insulating Sn-doped Bi1.1Sb0.9Te2S crystal by using time-domain terahertz spectroscopy. This compound shows much better insulating behavior than any other bulk-insulating topological insulators reported previously. The transmission can be enhanced an amount which is 5 % of the zero-field transmission by applying magnetic field to 7 T, an effect which we believe is due to the suppression of topological surface states. This suppression is essentially independent of the thicknesses of the samples, showing the two-dimensional nature of the transport. The suppression of surface states in field allows us to use the crystal slab itself as a reference sample to extract the surface conductance, mobility, charge density, and scattering rate. Our measurements set the stage for the investigation of phenomena out of the semiclassical regime, such as the topological magnetoelectric effect.

  16. Electronic structure origin of conductivity and oxygen reduction activity changes in low-level Cr-substituted (La,Sr)MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Tsekouras, George, E-mail: georget@uow.edu.au; Boudoire, Florent; Braun, Artur [Laboratory for High Performance Ceramics, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (Switzerland); Pal, Banabir; Sarma, D. D. [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore (India); Vondráček, Martin [Institute of Physics, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Prince, Kevin C. [Materials Science Beamline, Elettra Synchrotron, Trieste (Italy)

    2015-09-21

    The electronic structure of the (La{sub 0.8}Sr{sub 0.2}){sub 0.98}Mn{sub 1−x}Cr{sub x}O{sub 3} model series (x = 0, 0.05, or 0.1) was measured using soft X-ray synchrotron radiation at room and elevated temperature. O K-edge near-edge X-ray absorption fine structure (NEXAFS) spectra showed that low-level chromium substitution of (La,Sr)MnO{sub 3} resulted in lowered hybridisation between O 2p orbitals and M 3d and M 4sp valance orbitals. Mn L{sub 3}-edge resonant photoemission spectroscopy measurements indicated lowered Mn 3d–O 2p hybridisation with chromium substitution. Deconvolution of O K-edge NEXAFS spectra took into account the effects of exchange and crystal field splitting and included a novel approach whereby the pre-peak region was described using the nominally filled t{sub 2g}↑ state. 10% chromium substitution resulted in a 0.17 eV lowering in the energy of the t{sub 2g}↑ state, which appears to provide an explanation for the 0.15 eV rise in activation energy for the oxygen reduction reaction, while decreased overlap between hybrid O 2p–Mn 3d states was in qualitative agreement with lowered electronic conductivity. An orbital-level understanding of the thermodynamically predicted solid oxide fuel cell cathode poisoning mechanism involving low-level chromium substitution on the B-site of (La,Sr)MnO{sub 3} is presented.

  17. First-principles studies on the equation of state, thermal conductivity, and opacity of deuterium-tritium (DT) and polystyrene (CH) for inertial confinement fusion applications

    Science.gov (United States)

    Hu, S. X.; Collins, L. A.; Goncharov, V. N.; Kress, J. D.; Boehly, T. R.; Epstein, R.; McCrory, R. L.; Skupsky, S.

    2016-05-01

    Using first-principles (FP) methods, we have performed ab initio compute for the equation of state (EOS), thermal conductivity, and opacity of deuterium-tritium (DT) in a wide range of densities and temperatures for inertial confinement fusion (ICF) applications. These systematic investigations have recently been expanded to accurately compute the plasma properties of CH ablators under extreme conditions. In particular, the first-principles EOS and thermal-conductivity tables of CH are self-consistently built from such FP calculations, which are benchmarked by experimental measurements. When compared with the traditional models used for these plasma properties in hydrocodes, significant differences have been identified in the warm dense plasma regime. When these FP-calculated properties of DT and CH were used in our hydrodynamic simulations of ICF implosions, we found that the target performance in terms of neutron yield and energy gain can vary by a factor of 2 to 3, relative to traditional model simulations.

  18. Shaping of action potentials by type I and type II large-conductance Ca²+-activated K+ channels.

    Science.gov (United States)

    Jaffe, D B; Wang, B; Brenner, R

    2011-09-29

    The BK channel is a Ca(2+) and voltage-gated conductance responsible for shaping action potential waveforms in many types of neurons. Type II BK channels are differentiated from type I channels by their pharmacology and slow gating kinetics. The β4 accessory subunit confers type II properties on BK α subunits. Empirically derived properties of BK channels, with and without the β4 accessory subunit, were obtained using a heterologous expression system under physiological ionic conditions. These data were then used to study how BK channels alone (type I) and with the accessory β4 subunit (type II) modulate action potential properties in biophysical neuron models. Overall, the models support the hypothesis that it is the slower kinetics provided by the β4 subunit that endows the BK channel with type II properties, which leads to broadening of action potentials and, secondarily, to greater recruitment of SK channels reducing neuronal excitability. Two regions of parameter space distinguished type II and type I effects; one where the range of BK-activating Ca(2+) was high (>20 μM) and the other where BK-activating Ca(2+) was low (∼0.4-1.2 μM). The latter required an elevated BK channel density, possibly beyond a likely physiological range. BK-mediated sharpening of the spike waveform associated with the lack of the β4 subunit was sensitive to the properties of voltage-gated Ca(2+) channels due to electrogenic effects on spike duration. We also found that depending on Ca(2+) dynamics, type II BK channels may have the ability to contribute to the medium AHP, a property not generally ascribed to BK channels, influencing the frequency-current relationship. Finally, we show how the broadening of action potentials conferred by type II BK channels can also indirectly increase the recruitment of SK-type channels decreasing the excitability of the neuron.

  19. Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca(2+)-Activated K(+) Channels In Vitro.

    Science.gov (United States)

    Su, Fang; Guo, An-Chen; Li, Wei-Wei; Zhao, Yi-Long; Qu, Zheng-Yi; Wang, Yong-Jun; Wang, Qun; Zhu, Yu-Lan

    2017-02-01

    Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion; however, the underlying mechanism has not been elucidated. In the present study, we showed that expression of the neuronal large-conductance, Ca(2+)-activated K(+) channel (BKCa) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) compared with controls. Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R, attenuated the OGD/R-induced elevation of cytosolic Ca(2+) levels, and reduced the number of apoptotic neurons. Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax. The protective effect of ethanol preconditioning was antagonized by a BKCa channel inhibitor, paxilline. Inside-out patches in primary neurons also demonstrated the direct activation of the BKCa channel by 10 mmol/L ethanol. The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca(2+) and preventing neuronal apoptosis, and this is mediated by BKCa channel activation.

  20. Transparent and electrically conductive GaSb/Si direct wafer bonding at low temperatures by argon-beam surface activation

    Science.gov (United States)

    Predan, F.; Reinwand, D.; Klinger, V.; Dimroth, F.

    2015-10-01

    Direct wafer bonds of the material system n-GaSb/n-Si have been achieved by means of a low-temperature direct wafer bonding process, enabling an optical transparency of the bonds along with a high electrical conductivity of the boundary layer. In the used technique, the surfaces are activated by sputter-etching with an argon fast-atom-beam (FAB) and bonded in ultra-high vacuum. The bonds were annealed at temperatures between 300 and 400 °C, followed by an optical, mechanical and electrical characterization of the interface. Additionally, the influence of the sputtering on the surface topography of the GaSb was explicitly investigated. Fully bonded wafer pairs with high bonding strengths were found, as no blade could be inserted into the bonds without destroying the samples. The interfacial resistivities of the bonded wafers were significantly reduced by optimizing the process parameters, by which Ohmic interfacial resistivities of less than 5 mΩ cm2 were reached reproducibly. These promising results make the monolithic integration of GaSb on Si attractive for various applications.

  1. KCNN Genes that Encode Small-Conductance Ca2+-Activated K+ Channels Influence Alcohol and Drug Addiction.

    Science.gov (United States)

    Padula, Audrey E; Griffin, William C; Lopez, Marcelo F; Nimitvilai, Sudarat; Cannady, Reginald; McGuier, Natalie S; Chesler, Elissa J; Miles, Michael F; Williams, Robert W; Randall, Patrick K; Woodward, John J; Becker, Howard C; Mulholland, Patrick J

    2015-07-01

    Small-conductance Ca(2+)-activated K(+) (KCa2) channels control neuronal excitability and synaptic plasticity, and have been implicated in substance abuse. However, it is unknown if genes that encode KCa2 channels (KCNN1-3) influence alcohol and drug addiction. In the present study, an integrative functional genomics approach shows that genetic datasets for alcohol, nicotine, and illicit drugs contain the family of KCNN genes. Alcohol preference and dependence QTLs contain KCNN2 and KCNN3, and Kcnn3 transcript levels in the nucleus accumbens (NAc) of genetically diverse BXD strains of mice predicted voluntary alcohol consumption. Transcript levels of Kcnn3 in the NAc negatively correlated with alcohol intake levels in BXD strains, and alcohol dependence enhanced the strength of this association. Microinjections of the KCa2 channel inhibitor apamin into the NAc increased alcohol intake in control C57BL/6J mice, while spontaneous seizures developed in alcohol-dependent mice following apamin injection. Consistent with this finding, alcohol dependence enhanced the intrinsic excitability of medium spiny neurons in the NAc core and reduced the function and protein expression of KCa2 channels in the NAc. Altogether, these data implicate the family of KCNN genes in alcohol, nicotine, and drug addiction, and identify KCNN3 as a mediator of voluntary and excessive alcohol consumption. KCa2.3 channels represent a promising novel target in the pharmacogenetic treatment of alcohol and drug addiction.

  2. Facile Preparation of Chloride-Conducting Membranes: First Step towards a Room-Temperature Solid-State Chloride-Ion Battery.

    Science.gov (United States)

    Gschwind, Fabienne; Steinle, Dominik; Sandbeck, Daniel; Schmidt, Celine; von Hauff, Elizabeth

    2016-12-01

    Three types of chloride-conducting membranes based on polyvinyl chloride, commercial gelatin, and polyvinyldifluoride-hexafluoropolymer are introduced in this report. The polymers are mixed with chloride-containing salts, such as tetrabutylammonium chloride, and cast to form membranes. We studied the structural properties, thermal stability, and electrochemical response of the membranes to understand chloride migration and transport. Finally, the membranes are tested in a prototype solid-state chloride-ion battery setup. The feasibility of the membranes for their potential use in anion batteries is discussed.

  3. Variations of structures and solid-state conductivity of isomeric silver(I) coordination polymers having linear and V-shaped thiophene-centered ditriazole ligands

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Bin [State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, 330063 (China); Geng, Jiao; Zhang, Lie [State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Huang, Wei, E-mail: whuang@nju.edu.cn [State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

    2014-07-01

    A pair of new linear and V-shaped acceptor–donor–acceptor (A−D−A) thiophene-centered ditriazole structural isomers, i.e., 2,5-di(1H-1,2,4-triazol-1-yl)thiophene (L{sup 1}) and 3,4-di(1H-1,2,4-triazol-1-yl)thiophene (L{sup 2}), has been synthesized and characterized. They are used as μ{sub 2}-bridging ligands to prepare a pair of silver(I) coordination polymers formulated as [Ag(L{sup 1})(NO{sub 3})]{sub n} (1) and [Ag(L{sup 2})(NO{sub 3})]{sub n} (2), which are also structural isomers at the supramolecular level. X-ray single-crystal diffraction analyses for 1 and 2 reveal that they exhibit the same one-dimensional (1D) coordination polymers but different structural architectures because of the distinguishable shape and configuration of isomeric ligands (L{sup 1} and L{sup 2}) and the alterations of the coordination numbers. More interestingly, compared with the free ligands, 1D silver(I) polymeric isomers 1 and 2 show significant enhancement of solid-state conductivity to different extents (1.42×10{sup 4} and 2.17×10{sup 3} times), where 6.96 times' enhancement of solid-state conductivity from 1 to 2 has been observed. The formation of Ag–N coordinative bonds and the configurational discrepancy of L{sup 1} and L{sup 2} are believed to play important roles in facilitating the electron transport between molecules, which can also be supported by Density Function Theory calculations of their band gaps. - Graphical abstract: A pair of linear and V-shaped isomeric thiophene-centered ditriazole ligands (L{sup 1}) and L{sup 2} are used to prepare a pair of silver(I) polymeric isomers (1 and 2), where significant enhancement of solid-state conductivity to different extents are observed originating from the distinguishable shape and configuration of isomeric ligands. - Highlights: • A pair of linear and V-shaped thiophene-centered ditriazole structural isomers is prepared. • They are used as µ{sub 2}-bridging ligands to prepare a pair of silver

  4. Solid-State Dye-Sensitized Solar Cells using Ordered TiO2 Nanorods on Transparent Conductive Oxide as Photoanodes

    OpenAIRE

    Wang, Mingkui; Bai, Jie; Le Formal, Florian; Moon, Soo-Jin; Cevey-Ha, Le; Humphry-Baker, Robin; Graetzel, Carole; Zakeeruddin, Shaik M.; Graetzel, Michael

    2012-01-01

    TiO2 nanorod arrays were prepared on top of a transparent conductive glass substrate covered with a thin TiO2 compact layer. Solid-state dye-sensitized solar cells (SSDSCs) were fabricated using these structured TiO2 films sensitized with C106 dye as a photoanode and 2,2',7,7'-tetrakis-(N,N-dipmethoxyphenylamine) 9,9'-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. Photovoltaic power conversion efficiency of 2.9% was obtained at full sunlight intensity. The electron ...

  5. INTERFACE STATES PARAMETERS DEDUCED FROM DLTS, ICTS AND CONDUCTANCE METHODS ON TiAu/Si3N4/GaInAs MIS STRUCTURES

    OpenAIRE

    Barrier, J; Renaud, M.; Boher, P; Schneider, Jodi

    1988-01-01

    A set of electrical characterization methods has been developed using DLTS, ICTS and Conductance techniques. Taking into account corrections due to the variation of capture cross section versus energy, this method allows for a coherent determination of interface states parameters and has been used on TiAu/Si3N4/Ga0.47In0.53As MIS structures. It has been applied to perform an efficient passivation process of the Si3N4/GaInAs interface consisting in an in situ native oxide removal and Si3N4 dep...

  6. Steady-state turbulent flow of a conducting liquid in a longitudinal magnetic field with volume heat evolution. I. Analytical study of flow in the inwall region

    Energy Technology Data Exchange (ETDEWEB)

    Bortsaikin, S.M.; Levitan, Yu.S.

    1977-07-01

    An examination is made of steady-state turbulent flow of a conducting liquid in a cylindrical channel in a longitudinal magnetic field. The system of motion equations and energy can be recorded in a convenient integral form by using the Prandtl hypothesis for computing turbulent coefficients with rather simple assumptions about the nature of the velocity gradient. A small parameter in the equations can be easily identified in direct proximity to the channel's wall that makes it possible to find an approximate analytical solution to this problem in this region. 6 references, 1 figure.

  7. Conduct disorder

    Science.gov (United States)

    ... Conduct disorder is often linked to attention-deficit disorder . Conduct disorder also can be an early sign of ... child or teen has a history of conduct disorder behaviors. A physical examination and blood tests can help ...

  8. Student Activism in the High Schools of New York State.

    Science.gov (United States)

    Haake, Bernard F.; Langworthy, Philip B.

    The purpose of nine regional meetings between New York State Education Department personnel, educators and students from selected secondary school districts was to obtain information about unrest and the changing expectations of high school students. The following conclusions were made: (1) rising expectations of students are part of the "times,"…

  9. Solid-state fermentation: modelling fungal growth and activity.

    NARCIS (Netherlands)

    Smits, J.P.

    1998-01-01

    In solid-state fermentation (SSF) research, it is not possible to separate biomass quantitatively from the substrate. The evolution of biomass dry weight in time can therefore not be measured. Of the aiternatives to dry weight available, glucosamine content is most promising.Glucosamine is the monom

  10. 34 CFR 300.704 - State-level activities.

    Science.gov (United States)

    2010-07-01

    ... with disabilities, based on scientifically based research to improve educational instruction, in order to improve academic achievement to meet or exceed the objectives established by the State under..., and numeracy skills) in accordance with Part C of the Act to children with disabilities who...

  11. Resting-State Oscillatory Activity in Autism Spectrum Disorders

    Science.gov (United States)

    Cornew, Lauren; Roberts, Timothy P. L.; Blaskey, Lisa; Edgar, J. Christopher

    2012-01-01

    Neural oscillatory anomalies in autism spectrum disorders (ASD) suggest an excitatory/inhibitory imbalance; however, the nature and clinical relevance of these anomalies are unclear. Whole-cortex magnetoencephalography data were collected while 50 children (27 with ASD, 23 controls) underwent an eyes-closed resting-state exam. A Fast Fourier…

  12. Non-Linear Conduction in the Density Wave State of Quasi-Two Dimensional Organic Conductor α-(BEDT-TTF)2KHg(SCN)4

    Science.gov (United States)

    Fujita, Toshiyuki; Sasaki, Takahiko; Yoneyama, Naoki; Kobayashi, Norio

    2004-06-01

    Current-voltage characteristics are measured in the quasi-two dimensional organic conductor α-(BEDT-TTF)2KHg(SCN)4 at temperatures down to 0.5 K and in the magnetic field up to 25 T. The non-linear conduction with a threshold electric field is found in the density wave state. The features of threshold electric field obtained in the low magnetic field region are explained by the unconventional charge density wave model. In the high magnetic field region, where the Shubnikov-de Haas oscillations appear, the current-voltage characteristics reveal that the density wave state synchronizes with the filling of the electron on the Landau level and continues even above a kink field 23 T.

  13. Training Activity Summary Page (TASP) State and Tribe

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Training Activity Summary Page (formerly the Training Exit Survey Cover Page) dataset contains data about each training event. This dataset includes information...

  14. Dissociation between mental fatigue and motivational state during prolonged mental activity

    Directory of Open Access Journals (Sweden)

    Monika eGergelyfi

    2015-07-01

    Full Text Available Mental fatigue (MF is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement.Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, skin conductance responses, questionnaires and performance in a working memory task in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 minutes. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants’ subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources.

  15. Dissociation between mental fatigue and motivational state during prolonged mental activity

    Science.gov (United States)

    Gergelyfi, Mónika; Jacob, Benvenuto; Olivier, Etienne; Zénon, Alexandre

    2015-01-01

    Mental fatigue (MF) is commonly observed following prolonged cognitive activity and can have major repercussions on the daily life of patients as well as healthy individuals. Despite its important impact, the cognitive processes involved in MF remain largely unknown. An influential hypothesis states that MF does not arise from a disruption of overused neural processes but, rather, is caused by a progressive decrease in motivation-related task engagement. Here, to test this hypothesis, we measured various neural, autonomic, psychometric and behavioral signatures of MF and motivation (EEG, ECG, pupil size, eye blinks, Skin conductance responses (SCRs), questionnaires and performance in a working memory (WM) task) in healthy volunteers, while MF was induced by Sudoku tasks performed for 120 min. Moreover extrinsic motivation was manipulated by using different levels of monetary reward. We found that, during the course of the experiment, the participants’ subjective feeling of fatigue increased and their performance worsened while their blink rate and heart rate variability (HRV) increased. Conversely, reward-induced EEG, pupillometric and skin conductance signal changes, regarded as indicators of task engagement, remained constant during the experiment, and failed to correlate with the indices of MF. In addition, MF did not affect a simple reaction time task, despite the strong influence of extrinsic motivation on this task. Finally, alterations of the motivational state through monetary incentives failed to compensate the effects of MF. These findings indicate that MF in healthy subjects is not caused by an alteration of task engagement but is likely to be the consequence of a decrease in the efficiency, or availability, of cognitive resources. PMID:26217203

  16. Some Directions in State Activities of Ye. F. Kankrin

    Directory of Open Access Journals (Sweden)

    Olga G. Larina

    2014-03-01

    Full Text Available The article studies biographical facts on Yegor Frantsevich Kankrin and contains an analysis of his activities in the office of Minister of Finance. Based on the archive, biographical and legislative sources, the article considers the system of measures taken by Kankrin in the financial, industrial, mining, wood industry and educational spheres. The authors studied his work at the Jewish (second Committee as well as the drawbacks in his professional activities and the reasons behind them.

  17. Regulation of Guinea Pig Detrusor Smooth Muscle Excitability by 17β-Estradiol: The Role of the Large Conductance Voltage- and Ca2+-Activated K+ Channels.

    Science.gov (United States)

    Provence, Aaron; Hristov, Kiril L; Parajuli, Shankar P; Petkov, Georgi V

    2015-01-01

    Estrogen replacement therapies have been suggested to be beneficial in alleviating symptoms of overactive bladder. However, the precise regulatory mechanisms of estrogen in urinary bladder smooth muscle (UBSM) at the cellular level remain unknown. Large conductance voltage- and Ca2+-activated K+ (BK) channels, which are key regulators of UBSM function, are suggested to be non-genomic targets of estrogens. This study provides an electrophysiological investigation into the role of UBSM BK channels as direct targets for 17β-estradiol, the principle estrogen in human circulation. Single BK channel recordings on inside-out excised membrane patches and perforated whole cell patch-clamp were applied in combination with the BK channel selective inhibitor paxilline to elucidate the mechanism of regulation of BK channel activity by 17β-estradiol in freshly-isolated guinea pig UBSM cells. 17β-Estradiol (100 nM) significantly increased the amplitude of depolarization-induced whole cell steady-state BK currents and the frequency of spontaneous transient BK currents in freshly-isolated UBSM cells. The increase in whole cell BK currents by 17β-estradiol was eliminated upon blocking BK channels with paxilline. 17β-Estradiol (100 nM) significantly increased (~3-fold) the single BK channel open probability, indicating direct 17β-estradiol-BK channel interactions. 17β-Estradiol (100 nM) caused a significant hyperpolarization of the membrane potential of UBSM cells, and this hyperpolarization was reversed by blocking the BK channels with paxilline. 17β-Estradiol (100 nM) had no effects on L-type voltage-gated Ca2+ channel currents recorded under perforated patch-clamp conditions. This study reveals a new regulatory mechanism in the urinary bladder whereby BK channels are directly activated by 17β-estradiol to reduce UBSM cell excitability.

  18. National Study of State Universities and Land Grant Colleges: Off Campus Inservice Activities.

    Science.gov (United States)

    Seldin, Clement A.

    Information concerning off-campus inservice activity (OCIA) at state universities and land grant colleges in the United States was surveyed. There was a 92.5 percent response rate to questionnaires sent to 107 deans of schools, colleges, and departments of education. Inservice activities were considered to be courses, workshops, needs assessments,…

  19. 31 CFR 538.531 - Official activities of the United States Government and international organizations.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Official activities of the United States Government and international organizations. 538.531 Section 538.531 Money and Finance: Treasury....531 Official activities of the United States Government and international organizations. (a)...

  20. Measuring the performance of multi-agency programmatic permits for Washington State Department of Transportation activities

    OpenAIRE

    2005-01-01

    In 2001, the Washington State Legislature established the Transportation Permit Efficiency and Accountability Committee (TPEAC) to identify measures to streamline permit procedures for transportation activities and improve environmental outcomes. A programmatic subcommittee was created to develop a multi-agency approach for developing programmatic permits that would cover 60 to 70 percent of Washington State Department of Transportation (WSDOT) activities (mostly maintenance and preservation ...

  1. Inhibition of a cAMP-dependent Ca-activated K conductance by forskolin prolongs Ca action potential duration in lamprey sensory neurons.

    Science.gov (United States)

    Womble, M D; Wickelgren, W O

    1990-06-04

    Intracellular recordings from primary mechanosensory neurons (dorsal cells) of the lamprey spinal cord were made to test the membrane effects of forskolin, an activator of adenylate cyclase in these cells. At a concentration of 50 microM, forskolin was found to have a pronounced broadening effect on calcium action potentials (Ca APs) produced in the presence of voltage-activated K channel blockers (TEA, 3,4-DAP). Forskolin had no effect on passive membrane properties of the cells, such as resting potential or input resistance. Nor did it affect delayed rectification or Na APs and thus appeared not to block voltage-activated K channels. Forskolin's effect was evident only when a significant Ca component to the AP was present. It appeared not to increase the conductance of the Ca channel since its action was accompanied by a decrease in membrane conductance during the Ca AP, indicating instead an inhibition of a repolarizing Ca-activated conductance, other than a Ca-activated Cl conductance. The prolongation of Ca APs by forskolin, barium or the neurotransmitter GABA were all correlated in voltage-clamp with a decrease in outward current. Under the conductions used here, the major outward conductance in dorsal cells is a Ca-activated K conductance (gK(Ca]28, and it is concluded that the most probable mode of action for forskolin is via a cyclic AMP-mediated inhibition of this conductance. GABA has also been shown to prolong Ca APs in lamprey dorsal cells by inhibiting a repolarizing gK(Ca)28. Thus, the action of this transmitter may be mediated by an increase in intracellular cyclic AMP.

  2. Inhibition of Ca2+-activated large-conductance K+ channel activity alters synaptic AMPA receptor phenotype in mouse cerebellar stellate cells.

    Science.gov (United States)

    Liu, Yu; Savtchouk, Iaroslav; Acharjee, Shoana; Liu, Siqiong June

    2011-07-01

    Many fast-spiking inhibitory interneurons, including cerebellar stellate cells, fire brief action potentials and express α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-type glutamate receptors (AMPAR) that are permeable to Ca(2+) and do not contain the GluR2 subunit. In a recent study, we found that increasing action potential duration promotes GluR2 gene transcription in stellate cells. We have now tested the prediction that activation of potassium channels that control the duration of action potentials can suppress the expression of GluR2-containing AMPARs at stellate cell synapses. We find that large-conductance Ca(2+)-activated potassium (BK) channels mediate a large proportion of the depolarization-evoked noninactivating potassium current in stellate cells. Pharmacological blockade of BK channels prolonged the action potential duration in postsynaptic stellate cells and altered synaptic AMPAR subtype from GluR2-lacking to GluR2-containing Ca(2+)-impermeable AMPARs. An L-type channel blocker abolished an increase in Ca(2+) entry that was associated with spike broadening and also prevented the BK channel blocker-induced switch in AMPAR phenotype. Thus blocking BK potassium channels prolongs the action potential duration and increases the expression of GluR2-containing receptors at the synapse by enhancing Ca(2+) entry in cerebellar stellate cells.

  3. Pedestrian-oriented zoning is associated with reduced income and poverty disparities in adult active travel to work, United States.

    Science.gov (United States)

    Chriqui, Jamie F; Leider, Julien; Thrun, Emily; Nicholson, Lisa M; Slater, Sandy J

    2017-02-01

    Active travel to work can provide additional minutes of daily physical activity. While the literature points to the relationship between zoning, equity and socioeconomic status, and physical activity, no study has quantitatively explored these connections. This study examined whether zoning may help to moderate any income and poverty inequities in active travel and taking public transit to work. Research was conducted between May 2012 and June 2015. Zoning data were compiled for 3914 jurisdictions covering 45.45% of the U.S. population located in 471 of the most populous U.S. counties and 2 consolidated cities located in 48 states and the District of Columbia. (Sensitivity analyses also captured unincorporated areas which, with the municipalities, collectively covered ~72% of the U.S.

  4. Overview of electromagnetic methods applied in active volcanic areas of western United States

    Science.gov (United States)

    Skokan, Catherine K.

    1993-06-01

    A better understanding of active volcanic areas in the United States through electromagnetic geophysical studies received foundation from the many surveys done for geothermal exploration in the 1970's. Investigations by governmental, industrial, and academic agencies include (but are not limited to) mapping of the Cascades. Long Valley/Mono area, the Jemez volcanic field, Yellowstone Park, and an area in Colorado. For one example — Mt. Konocti in the Mayacamas Mountains, California — gravity, magnetic, and seismic, as well as electromagnetic methods have all been used in an attempt to gain a better understanding of the subsurface structure. In each of these volcanic regions, anomalous zones were mapped. When conductive, these anomalies were interpreted to be correlated with hydrothermal activity and not to represent a magma chamber. Electrical and electromagnetic geophysical methods can offer valuable information in the understanding of volcanoes by being the method which is most sensitive to change in temperature and, therefore, can best map heat budget and hydrological character to aid in prediction of eruptions.

  5. An amino acid outside the pore region influences apamin sensitivity in small conductance Ca2+-activated K+ channels.

    Science.gov (United States)

    Nolting, Andreas; Ferraro, Teresa; D'hoedt, Dieter; Stocker, Martin

    2007-02-01

    Small conductance calcium-activated potassium channels (SK, K(Ca)) are a family of voltage-independent K+ channels with a distinct physiology and pharmacology. The bee venom toxin apamin inhibits exclusively the three cloned SK channel subtypes (SK1, SK2, and SK3) with different affinity, highest for SK2, lowest for SK1, and intermediate for SK3 channels. The high selectivity of apamin made it a valuable tool to study the molecular makeup and function of native SK channels. Three amino acids located in the outer vestibule of the pore are of particular importance for the different apamin sensitivities of SK channels. Chimeric SK1 channels, enabling the homomeric expression of the rat SK1 (rSK1) subunit and containing the core domain (S1-S6) of rSK1, are apamin-insensitive. By contrast, channels formed by the human orthologue human SK1 (hSK1) are sensitive to apamin. This finding hinted at the involvement of regions beyond the pore as determinants of apamin sensitivity, because hSK1 and rSK1 have an identical amino acid sequence in the pore region. Here we investigated which parts of the channels outside the pore region are important for apamin sensitivity by constructing chimeras between apamin-insensitive and -sensitive SK channel subunits and by introducing point mutations. We demonstrate that a single amino acid situated in the extracellular loop between the transmembrane segments S3 and S4 has a major impact on apamin sensitivity. Our findings enabled us to convert the hSK1 channel into a channel that was as sensitive for apamin as SK2, the SK channel with the highest sensitivity.

  6. Small-conductance Ca2+-activated potassium type 2 channels regulate the formation of contextual fear memory.

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    Saravana R K Murthy

    Full Text Available Small-conductance, Ca2+ activated K+ channels (SK channels are expressed at high levels in brain regions responsible for learning and memory. In the current study we characterized the contribution of SK2 channels to synaptic plasticity and to different phases of hippocampal memory formation. Selective SK2 antisense-treatment facilitated basal synaptic transmission and theta-burst induced LTP in hippocampal brain slices. Using the selective SK2 antagonist Lei-Dab7 or SK2 antisense probes, we found that hippocampal SK2 channels are critical during two different time windows: 1 blockade of SK2 channels before the training impaired fear memory, whereas, 2 blockade of SK2 channels immediately after the training enhanced contextual fear memory. We provided the evidence that the post-training cleavage of the SK2 channels was responsible for the observed bidirectional effect of SK2 channel blockade on memory consolidation. Thus, Lei-Dab7-injection before training impaired the C-terminal cleavage of SK2 channels, while Lei-Dab7 given immediately after training facilitated the C-terminal cleavage. Application of the synthetic peptide comprising a leucine-zipper domain of the C-terminal fragment to Jurkat cells impaired SK2 channel-mediated currents, indicating that the endogenously cleaved fragment might exert its effects on memory formation by blocking SK2 channel-mediated currents. Our present findings suggest that SK2 channel proteins contribute to synaptic plasticity and memory not only as ion channels but also by additionally generating a SK2 C-terminal fragment, involved in both processes. The modulation of fear memory by down-regulating SK2 C-terminal cleavage might have applicability in the treatment of anxiety disorders in which fear conditioning is enhanced.

  7. Influence of point defects on the phonon thermal conductivity and phonon density of states of Bi{sub 2}Te{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Bedoya-Martinez, O.N.; Hashibon, A.; Elsaesser, C. [Fraunhofer IWM, Freiburg (Germany)

    2016-03-15

    The influence of point defects on the lattice thermal conductivity and vibrational properties of Bi{sub 2}Te{sub 3} were studied by using equilibrium and non-equilibrium molecular-dynamics simulations. Three types of point defects at various concentrations were considered, namely Bi and Te vacancies and Bi anti-sites. It is shown that point defects can result in a reduction of up to 80% of the bulk thermal conductivity. A detailed analysis of the phonon density of states (PDOS) of the studied systems is provided. Element (Bi or Te) and orientation (in-plane or cross-plane) resolved PDOS were calculated. In agreement with experimental observations and other simulations, features in the PDOS were identified with specific atomic and orientation contributions. Systems containing point defects exhibit a broadening of the PDOS peaks as the defect concentration increases, which is due to the disorder induced by the defects. Such disorder leads to a higher phonon scattering and thus to a lower lattice thermal conductivity. Tuning the point defect type and concentrations during growth may, therefore, provide a route for optimizing Bi{sub 2}Te{sub 3} based thermoelectric devices. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Models of Innovation Activity Firms and the Competitive State

    Directory of Open Access Journals (Sweden)

    Nekrasova Ekaterina, A.

    2015-12-01

    Full Text Available The paper clarified the concept of innovation activity of firms from the perspective of the model open innovation with traditional and alternative approaches to the methods of the protection of innovation activity results outlined. With the use of institutional tools, theoretical concepts and practical study the patterns of innovative activity of firms (external, internal & cooperative strategies are analyzed and the selection criteria for models of innovation are proposed on the basis of a comparison of transaction costs and benefits specific to the closed forms and conditions for cooperation. The forms of cooperation, their pros & cons are mentioned given the results of some empirical evidence. Practical recommendations for the Russian companies to organize their innovation activities are given, as well as on the improvement of competition policy with regard to the inclusion of innovation factor in the analysis of mergers in Russia (also based on the mechanism of the use of this factor by means of merger simulation models. The paper also suggests the criteria for the evaluation of collaborative R&D projects of firms as antitrust tools aimed to use the “rule of reason” when the decisions are made.

  9. TiO 2 Conduction Band Modulation with In 2 O 3 Recombination Barrier Layers in Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Brennan, Thomas P.

    2013-11-21

    Atomic layer deposition (ALD) was used to grow subnanometer indium oxide recombination barriers in a solid-state dye-sensitized solar cell (DSSC) based on the spiro-OMeTAD hole-transport material (HTM) and the WN1 donor-π-acceptor organic dye. While optimal device performance was achieved after 3-10 ALD cycles, 15 ALD cycles (∼2 Å of In2O 3) was observed to be optimal for increasing open-circuit voltage (VOC) with an average improvement of over 100 mV, including one device with an extremely high VOC of 1.00 V. An unexpected phenomenon was observed after 15 ALD cycles: the increasing VOC trend reversed, and after 30 ALD cycles VOC dropped by over 100 mV relative to control devices without any In2O3. To explore possible causes of the nonmonotonic behavior resulting from In2O3 barrier layers, we conducted several device measurements, including transient photovoltage experiments and capacitance measurements, as well as density functional theory (DFT) studies. Our results suggest that the VOC gains observed in the first 20 ALD cycles are due to both a surface dipole that pulls up the TiO2 conduction band and recombination suppression. After 30 ALD cycles, however, both effects are reversed: the surface dipole of the In2O3 layer reverses direction, lowering the TiO 2 conduction band, and mid-bandgap states introduced by In 2O3 accelerate recombination, leading to a reduced V OC. © 2013 American Chemical Society.

  10. Monitoring and validating active site redox states in protein crystals.

    Science.gov (United States)

    Antonyuk, Svetlana V; Hough, Michael A

    2011-06-01

    High resolution protein crystallography using synchrotron radiation is one of the most powerful tools in modern biology. Improvements in resolution have arisen from the use of X-ray beamlines with higher brightness and flux and the development of advanced detectors. However, it is increasingly recognised that the benefits brought by these advances have an associated cost, namely deleterious effects of X-ray radiation on the sample (radiation damage). In particular, X-ray induced reduction and damage to redox centres has been shown to occur much more rapidly than other radiation damage effects, such as loss of resolution or damage to disulphide bridges. Selection of an appropriate combination of in-situ single crystal spectroscopies during crystallographic experiments, such as UV-visible absorption and X-ray absorption spectroscopy (XAFS), allows for effective monitoring of redox states in protein crystals in parallel with structure determination. Such approaches are also essential in cases where catalytic intermediate species are generated by exposure to the X-ray beam. In this article, we provide a number of examples in which multiple single crystal spectroscopies have been key to understanding the redox status of Fe and Cu centres in crystal structures. This article is part of a Special Issue entitled: Protein Structure and Function in the Crystalline State.

  11. United States-Russia: Environmental management activities, Summer 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    A Joint Coordinating Committee for Environmental Restoration and Waste Management (JCCEM) was formed between the US and Russia. This report describes the areas of research being studied under JCCEM, namely: Efficient separations; Contaminant transport and site characterization; Mixed wastes; High level waste tank remediation; Transuranic stabilization; Decontamination and decommissioning; and Emergency response. Other sections describe: Administrative framework for cooperation; Scientist exchange; Future actions; Non-JCCEM DOE-Russian activities; and JCCEM publications.

  12. The research institutes as a form of scientific and economic State activity – the problem of their position and legal form

    Directory of Open Access Journals (Sweden)

    Małgorzata Cilak

    2015-12-01

    Full Text Available The research institutes are state-owned legal persons, created to conduct research focused on the economic use. They aren’t in public finance sector now. This might raise doubts. The article analyzes the legal status of research institutes and the character of their activities.

  13. A review of recent activity in the United States.

    Science.gov (United States)

    Cannon, H.L.; Petrie, W.L.

    1979-01-01

    Either an overabundance or a deficiency of trace metals in the food chain can ultimately affect adversely the health of livestock and man. Increasing interest in the United States in the distribution of metals in the environment and in metal pollutants has led to widespread interdisciplinary research sponsored by governmental, private and academic groups concerning the availability of trace elements for absorption by plants and animals, and the effects of trace elements throughout the food chain. Effects on the environment of coal-fired power plants, the mining and processing of metals, asbestos, and phosphate, and the disposal of industrial and nuclear wastes have also received much attention in the past few years.-Authors

  14. Predicting the activation states of the muscles governing upper esophageal sphincter relaxation and opening.

    Science.gov (United States)

    Omari, Taher I; Jones, Corinne A; Hammer, Michael J; Cock, Charles; Dinning, Philip; Wiklendt, Lukasz; Costa, Marcello; McCulloch, Timothy M

    2016-03-15

    The swallowing muscles that influence upper esophageal sphincter (UES) opening are centrally controlled and modulated by sensory information. Activation and deactivation of neural inputs to these muscles, including the intrinsic cricopharyngeus (CP) and extrinsic submental (SM) muscles, results in their mechanical activation or deactivation, which changes the diameter of the lumen, alters the intraluminal pressure, and ultimately reduces or promotes flow of content. By measuring the changes in diameter, using intraluminal impedance, and the concurrent changes in intraluminal pressure, it is possible to determine when the muscles are passively or actively relaxing or contracting. From these "mechanical states" of the muscle, the neural inputs driving the specific motor behaviors of the UES can be inferred. In this study we compared predictions of UES mechanical states directly with the activity measured by electromyography (EMG). In eight subjects, pharyngeal pressure and impedance were recorded in parallel with CP- and SM-EMG activity. UES pressure and impedance swallow profiles correlated with the CP-EMG and SM-EMG recordings, respectively. Eight UES muscle states were determined by using the gradient of pressure and impedance with respect to time. Guided by the level and gradient change of EMG activity, mechanical states successfully predicted the activity of the CP muscle and SM muscle independently. Mechanical state predictions revealed patterns consistent with the known neural inputs activating the different muscles during swallowing. Derivation of "activation state" maps may allow better physiological and pathophysiological interpretations of UES function.

  15. Overexpression of the Large-Conductance, Ca2+-Activated K+ (BK) Channel Shortens Action Potential Duration in HL-1 Cardiomyocytes.

    Science.gov (United States)

    Stimers, Joseph R; Song, Li; Rusch, Nancy J; Rhee, Sung W

    2015-01-01

    Long QT syndrome is characterized by a prolongation of the interval between the Q wave and the T wave on the electrocardiogram. This abnormality reflects a prolongation of the ventricular action potential caused by a number of genetic mutations or a variety of drugs. Since effective treatments are unavailable, we explored the possibility of using cardiac expression of the large-conductance, Ca2+-activated K+ (BK) channel to shorten action potential duration (APD). We hypothesized that expression of the pore-forming α subunit of human BK channels (hBKα) in HL-1 cells would shorten action potential duration in this mouse atrial cell line. Expression of hBKα had minimal effects on expression levels of other ion channels with the exception of a small but significant reduction in Kv11.1. Patch-clamped hBKα expressing HL-1 cells exhibited an outward voltage- and Ca2+-sensitive K+ current, which was inhibited by the BK channel blocker iberiotoxin (100 nM). This BK current phenotype was not detected in untransfected HL-1 cells or in HL-1 null cells sham-transfected with an empty vector. Importantly, APD in hBKα-expressing HL-1 cells averaged 14.3 ± 2.8 ms (n = 10), which represented a 53% reduction in APD compared to HL-1 null cells lacking BKα expression. APD in the latter cells averaged 31.0 ± 5.1 ms (n = 13). The shortened APD in hBKα-expressing cells was restored to normal duration by 100 nM iberiotoxin, suggesting that a repolarizing K+ current attributed to BK channels accounted for action potential shortening. These findings provide initial proof-of-concept that the introduction of hBKα channels into a cardiac cell line can shorten APD, and raise the possibility that gene-based interventions to increase hBKα channels in cardiac cells may hold promise as a therapeutic strategy for long QT syndrome.

  16. THE MODERN STATE OF ENTERPRISE INNOVATION ACTIVITY IN KAZAKHSTAN

    Directory of Open Access Journals (Sweden)

    Nurlan Kurmanov

    2015-09-01

    Full Text Available In the XXI century, the key to rapid socio-economic development is to have an effective innovation policy, aimed at introducing high "disruptive" technologies, new ways to organise and manage work, advanced inventions, and the means to progress scientific and technical achievements.The formation of an innovative economy in Kazakhstan is a complexity of economic, social, and political issues. An effective use of research findings and developments in the real economy is most important in terms of Kazakhstan’s successful competitiveness, assurance for high economic growth, improved quality of life, and to help realize other innovative priorities. In these circumstances, innovation management and development is becoming more relevant as the basis for developing Kazakh companies, by way of a defined set of relevant technical, operational, organizational, marketing, and financial operations.The purpose of this study is to identify characteristics and practical recommendations for the development and further improvement of management mechanisms relating to the innovative activity of enterprises in Kazakhstan. The study used a systematic approach of comparison, scientific abstraction, data collection, analysis and synthesis, applied expertise, and statistical methods. The core value of the work was to support the feasibility of a system for Kazakh enterprises to promote innovative activity and the development of high technologies.

  17. Regional Homogeneity of Resting-state fMRI Contributes to Both Neurovascular and Task Activation Variations

    Science.gov (United States)

    Yuan, Rui; Di, Xin; Kim, Eun H.; Barik, Sabrina; Rypma, Bart; Biswal, Bharat B.

    2013-01-01

    The task induced blood oxygenation level dependent signal changes observed using functional magnetic resonance imaging (fMRI) is critically dependent on the relationship between neuronal activity and hemodynamic response. Therefore, understanding the nature of neurovascular coupling is important when interpreting fMRI signal changes evoked via task. In this study, we used regional homogeneity (ReHo), a measure of local synchronization of the BOLD time series, to investigate whether the similarities of one voxel with the surrounding voxels is a property of neurovascular coupling. FMRI scans were obtained from fourteen subjects during bilateral finger tapping (FTAP), digit-symbol substitution (DSST) and periodic breath holding (BH) paradigm. A resting-state scan was also obtained for each of the subjects for 4 minutes using identical imaging parameters. Inter-voxel correlation analyses were conducted between the resting-state ReHo, resting-state amplitude of low frequency fluctuations (ALFF), breath hold (BH) responses and task activations within the masks related to task activations. There was a reliable mean voxel-wise spatial correlation between ReHo and other neurovascular variables (BH responses and ALFF). We observed a moderate correlation between ReHo and task activations (FTAP: r = 0.32; DSST: r = 0.22) within the task positive network and a small yet reliable correlation within the default mode network (DSST: r = −0.08). Subsequently, a linear regression was used to estimate the contribution of ReHo, ALFF and BH responses to the task activated voxels. The unique contribution of ReHo was minimal. The results suggest that regional synchrony of the BOLD activity is a property that can explain the variance of neurovascular coupling and task activations; but its contribution to task activations can be accounted for by other neurovascular factors such as the ALFF. PMID:23969197

  18. Quasi Solid-State Dye-Sensitized Solar Cell Incorporating Highly Conducting Polythiophene-Coated Carbon Nanotube Composites in Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2011-01-01

    Full Text Available Conducting polythiophene (PTh composites with the host filler multiwalled carbon nanotube (MWNT have been used, for the first time, in the dye-sensitized solar cells (DSCs. A quasi solid-state DSCs with the hybrid MWNT-PTh composites, an ionic liquid of 1-methyl-3-propyl imidazolium iodide (PMII, was placed between the dye-sensitized porous TiO2 and the Pt counter electrode without adding iodine and higher cell efficiency (4.76% was achieved, as compared to that containing bare PMII (0.29%. The MWNT-PTh nanoparticles are exploited as the extended electron transfer materials and serve simultaneously as catalyst for the electrochemical reduction of I−3.

  19. Cognitive functions and neuropsychological status of medical students with different attitudes to alcohol use: a study conducted at the Belarusian State Medical University, Minsk, Belarus.

    Science.gov (United States)

    Welcome, Menizibeya O; Razvodovsky, Yury E; Pereverzeva, Elena V; Pereverzev, Vladimir A

    2014-04-10

    This article presents findings on the effects of alcohol use on cognitive performance, functional (well-being, activity, mood) and neuropsychological status and anxiety levels of medical students. A total of 265 medical students (107 males and 158 females) from the Belarusian State Medical University, Minsk (Belarus) were administered questionnaire, containing the AUDIT, CAGE, MAST, and PAS, and other alcohol related questions. Academic Performance questionnaire was administered together with other tests. For analysis of cognitive functions, a "correction probe" test was used. The number of students who reported consumption of alcohol was 74 males and 142 females. Medical students who reported alcohol consumption had lower cognitive performance and academic success, poor self-assessment of their functional and neuropsychological states, compared to the non-alcohol users. The results of this study suggest an inverse dose-dependent relationship between alcohol consumption, and cognitive functions, academic performance and neuropsychological status of medical students.

  20. The large conductance Ca2+ -activated K+ (BKCa channel regulates cell proliferation in SH-SY5Y neuroblastoma cells by activating the staurosporine-sensitive protein kinases

    Directory of Open Access Journals (Sweden)

    Angela eCurci

    2014-12-01

    Full Text Available Here we investigated on the role of the calcium activated K+-channels(BKCa on the regulation of the neuronal viability. Recordings of the K+-channel current were performed using patch-clamp technique in human neuroblastoma cells (SH-SY5Y in parallel with measurements of the cell viability in the absence or presence of the BKCa channel blockers iberiotoxin(IbTX and tetraethylammonium (TEA and the BKCa channel opener NS1619. Protein kinase C/A (PKC, PKA activities in the cell lysate were investigated in the presence/absence of drugs. The whole-cell K+-current showed a slope conductance calculated at negative membrane potentials of 126.3 pS and 1.717 nS(n = 46 following depolarization. The intercept of the I/V curve was -33 mV. IbTX(10-8-4x10-7M reduced the K+-current at +30 mV with an IC50 of 1.85x10-7M and an Imax of -46%(slope=2.198(n =21. NS1619(10-100x10-6M enhanced the K+-current of +141%(n =6, at -10 mV(Vm. TEA(10-5-10-3M reduced the K+-current with an IC50 of 3.54x10-5M and an Imax of -90%(slope=0.95(n =5. A concentration-dependent increase of cell proliferation was observed with TEA showing a maximal proliferative effect(MPE of +38% (10-4M. IbTX showed an MPE of +42% at 10-8M concentration, reducing it at higher concentrations. The MPE of the NS1619(100x10-6M was +42%. The PKC inhibitor staurosporine (0.2-2x10-6M antagonized the proliferative actions of IbTX and TEA. IbTX (10x10-9M, TEA (100x10-6M and the NS1619 significantly enhanced the PKC and PKA activities in the cell lysate with respect to the controls. These results suggest that BKCa channel regulates proliferation of the SH-SY5Y cells through PKC and PKA protein kinases.

  1. Structural, dielectric and conductivity studies of LiNi0.75Mg0.25-xCuxPO4 synthesized by solid state reaction method

    Directory of Open Access Journals (Sweden)

    Kotamalige Anand

    2016-03-01

    Full Text Available The olivine structured LiNi0.75Mg0.25-xCuxPO4 (x = 0, 0.05 and 0.1 cathode materials were synthesized by solid state reaction method. The XRD, FTIR and FESEM studies were conducted to investigate the phase purity, crystal structure, lattice parameters and morphology, respectively. The powder X-ray diffraction studies confirmed the single phase formation of the pure and doped compounds which are found to be orthorhombic with the parent LiNiPO4. Morphology and grain sizes of the materials were investigated through FESEM. The FTIR technique was used to characterize the stretching and bending vibrational modes of different functional groups existing in the materials. The cathode properties were analysed through impedance spectroscopy and indicated on improved electrical properties of the doped samples as compared to the pure LiNiPO4. The conductivity and modulus analyses of the samples were carried out at different temperatures and frequencies using the complex impedance spectroscopy technique.

  2. Comparative proteome analysis of Milnesium tardigradum in early embryonic state versus adults in active and anhydrobiotic state.

    Directory of Open Access Journals (Sweden)

    Elham Schokraie

    Full Text Available Tardigrades have fascinated researchers for more than 300 years because of their extraordinary capability to undergo cryptobiosis and survive extreme environmental conditions. However, the survival mechanisms of tardigrades are still poorly understood mainly due to the absence of detailed knowledge about the proteome and genome of these organisms. Our study was intended to provide a basis for the functional characterization of expressed proteins in different states of tardigrades. High-throughput, high-accuracy proteomics in combination with a newly developed tardigrade specific protein database resulted in the identification of more than 3000 proteins in three different states: early embryonic state and adult animals in active and anhydrobiotic state. This comprehensive proteome resource includes protein families such as chaperones, antioxidants, ribosomal proteins, cytoskeletal proteins, transporters, protein channels, nutrient reservoirs, and developmental proteins. A comparative analysis of protein families in the different states was performed by calculating the exponentially modified protein abundance index which classifies proteins in major and minor components. This is the first step to analyzing the proteins involved in early embryonic development, and furthermore proteins which might play an important role in the transition into the anhydrobiotic state.

  3. Comparative proteome analysis of Milnesium tardigradum in early embryonic state versus adults in active and anhydrobiotic state.

    Science.gov (United States)

    Schokraie, Elham; Warnken, Uwe; Hotz-Wagenblatt, Agnes; Grohme, Markus A; Hengherr, Steffen; Förster, Frank; Schill, Ralph O; Frohme, Marcus; Dandekar, Thomas; Schnölzer, Martina

    2012-01-01

    Tardigrades have fascinated researchers for more than 300 years because of their extraordinary capability to undergo cryptobiosis and survive extreme environmental conditions. However, the survival mechanisms of tardigrades are still poorly understood mainly due to the absence of detailed knowledge about the proteome and genome of these organisms. Our study was intended to provide a basis for the functional characterization of expressed proteins in different states of tardigrades. High-throughput, high-accuracy proteomics in combination with a newly developed tardigrade specific protein database resulted in the identification of more than 3000 proteins in three different states: early embryonic state and adult animals in active and anhydrobiotic state. This comprehensive proteome resource includes protein families such as chaperones, antioxidants, ribosomal proteins, cytoskeletal proteins, transporters, protein channels, nutrient reservoirs, and developmental proteins. A comparative analysis of protein families in the different states was performed by calculating the exponentially modified protein abundance index which classifies proteins in major and minor components. This is the first step to analyzing the proteins involved in early embryonic development, and furthermore proteins which might play an important role in the transition into the anhydrobiotic state.

  4. Study of Schottky contact between Au and NiO nanowire by conductive atomic force microscopy (C-AFM): The case of surface states

    Science.gov (United States)

    Zhang, Yidong

    2015-05-01

    In this work, NiO nanowires have been synthesized by a hydrothermal reaction of NiCl2 with Na2C2O4 in the presence of ethylene glycol at 180 °C for 12 h, then calcinated at 400 °C for 2 h. The NiO nanowires were analyzed by means of scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The resulting current-voltage (I-V) characteristics of the NiO nanowires exhibited a clear rectifying behavior. This rectify behavior was attributed to the formation of a Schottky contact between Au coated atomic force microscopy (AFM) tip and NiO nanowires (nano-M/SC) which was dominated by the surface states in NiO itself. Photo-assisted conductive AFM (PC-AFM) was used to demonstrate how the I-V characteristics are influenced by the surface states. Our I-V results also showed that the nano-M/SCs had a good photoelectric switching effect at reverse bias.

  5. Heat Capacity and Thermal Conductance Measurements of a Superconducting-Normal Mixed State by Detection of Single 3 eV Photons in a Magnetic Penetration Thermometer

    Science.gov (United States)

    Stevenson, T. R.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Lee, S.-J.; Nagler, P. C.; Smith, S. J.

    2015-01-01

    We report on measurements of the detected signal pulses in a molybdenum-gold Magnetic Penetration Thermometer (MPT) in response to absorption of one or more 3 eV photons. We designed and used this MPT sensor for x-ray microcalorimetry. In this device, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons, and responsivity is enhanced by a Meissner transition in which the magnetic flux penetrating the sensor changes rapidly to minimize free energy in a mixed superconducting normal state. We have previously reported on use of our MPT to study a thermal phonon energy loss to the substrate when absorbing x-rays. We now describe results of extracting heat capacity C and thermal conductance G values from pulse height and decay time of MPT pulses generated by 3 eV photons. The variation in C and G at temperatures near the Meissner transition temperature (set by an internal magnetic bias field) allow us to probe the behavior in superconducting normal mixed state of the condensation energy and the electron cooling power resulting from quasi-particle recombination and phonon emission. The information gained on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

  6. Children’s Exposures to Pyrethroid Insecticides at Home: A Review of Data Collected in Published Exposure Measurement Studies Conducted in the United States

    Directory of Open Access Journals (Sweden)

    Marsha K. Morgan

    2012-08-01

    Full Text Available Pyrethroid insecticides are frequently used to control insects in residential and agriculture settings in the United States and worldwide. As a result, children can be potentially exposed to pyrethroid residues in food and at home. This review summarizes data reported in 15 published articles from observational exposure measurement studies conducted from 1999 to present that examined children’s (5 months to 17 years of age exposures to pyrethroids in media including floor wipes, floor dust, food, air, and/or urine collected at homes in the United States. At least seven different pyrethroids were detected in wipe, dust, solid food, and indoor air samples. Permethrin was the most frequently detected (>50% pyrethroid in these media, followed by cypermethrin (wipes, dust, and food. 3-phenoxybenzoic acid (3-PBA, a urinary metabolite of several pyrethroids, was the most frequently (≥67% detected pyrethroid biomarker. Results across studies indicate that these children were likely exposed to several pyrethroids, but primarily to permethrin and cypermethrin, from several sources including food, dust, and/or on surfaces at residences. Dietary ingestion followed by nondietary ingestion were the dominate exposure routes for these children, except in homes with frequent pesticide applications (dermal followed by dietary ingestion. Urinary 3-PBA concentration data confirm that the majority of the children sampled were exposed to one or more pyrethroids.

  7. Intensive Training Induces Longitudinal Changes in Meditation State-related EEG Oscillatory Activity

    Directory of Open Access Journals (Sweden)

    Manish eSaggar

    2012-09-01

    Full Text Available The capacity to focus one’s attention for an extended period of time can be increased through training in contemplative practices. However, the cognitive processes engaged during meditation that support trait changes in cognition are not well characterized. We conducted a longitudinal wait-list controlled study of intensive meditation training. Retreat participants practiced focused attention meditation techniques for three months during an initial retreat. Wait-list participants later undertook formally identical training during a second retreat. Dense-array scalp-recorded electroencephalogram (EEG data were collected during six minutes of mindfulness of breathing meditation at three assessment points during each retreat. Second-order blind source separation, along with a novel semi-automatic artifact removal tool, was used for data preprocessing. We observed replicable reductions in meditative state-related beta-band power bilaterally over anteriocentral and posterior scalp regions. In addition, individual alpha frequency decreased across both retreats and in direct relation to the amount of meditative practice. These findings provide evidence for replicable longitudinal changes in brain oscillatory activity during meditation and increase our understanding of the cortical processes engaged during meditation that may support long-term improvements in cognition.

  8. Intensive training induces longitudinal changes in meditation state-related EEG oscillatory activity.

    Science.gov (United States)

    Saggar, Manish; King, Brandon G; Zanesco, Anthony P; Maclean, Katherine A; Aichele, Stephen R; Jacobs, Tonya L; Bridwell, David A; Shaver, Phillip R; Rosenberg, Erika L; Sahdra, Baljinder K; Ferrer, Emilio; Tang, Akaysha C; Mangun, George R; Wallace, B Alan; Miikkulainen, Risto; Saron, Clifford D

    2012-01-01

    The capacity to focus one's attention for an extended period of time can be increased through training in contemplative practices. However, the cognitive processes engaged during meditation that support trait changes in cognition are not well characterized. We conducted a longitudinal wait-list controlled study of intensive meditation training. Retreat participants practiced focused attention (FA) meditation techniques for three months during an initial retreat. Wait-list participants later undertook formally identical training during a second retreat. Dense-array scalp-recorded electroencephalogram (EEG) data were collected during 6 min of mindfulness of breathing meditation at three assessment points during each retreat. Second-order blind source separation, along with a novel semi-automatic artifact removal tool (SMART), was used for data preprocessing. We observed replicable reductions in meditative state-related beta-band power bilaterally over anteriocentral and posterior scalp regions. In addition, individual alpha frequency (IAF) decreased across both retreats and in direct relation to the amount of meditative practice. These findings provide evidence for replicable longitudinal changes in brain oscillatory activity during meditation and increase our understanding of the cortical processes engaged during meditation that may support long-term improvements in cognition.

  9. Differential brain activity states during the perception and nonperception of illusory motion as revealed by magnetoencephalography.

    Science.gov (United States)

    Crowe, David A; Leuthold, Arthur C; Georgopoulos, Apostolos P

    2010-12-28

    We studied visual perception using an annular random-dot motion stimulus called the racetrack. We recorded neural activity using magnetoencephalography while subjects viewed variants of this stimulus that contained no inherent motion or various degrees of embedded motion. Subjects reported seeing rotary motion during viewing of all stimuli. We found that, in the absence of any motion signals, patterns of brain activity differed between states of motion perception and nonperception. Furthermore, when subjects perceived motion, activity states within the brain did not differ across stimuli of different amounts of embedded motion. In contrast, we found that during periods of nonperception brain-activity states varied with the amount of motion signal embedded in the stimulus. Taken together, these results suggest that during perception the brain may lock into a stable state in which lower-level signals are suppressed.

  10. The study of disk resonators diode modules, solid-state generators active

    Directory of Open Access Journals (Sweden)

    B. A. Kotserzhinskii

    1987-12-01

    Full Text Available The results of an experimental study of disk resonators diode modules, solid-state active microwave generators. The effect of current leads, as well as errors in the manufacture of resonators their characteristics.

  11. Two high-field thermodynamically stable conductivity states in photoconductive CdS, one n-type and one p-type

    Energy Technology Data Exchange (ETDEWEB)

    Böer, Karl W. [Department of Physics and Astronomy, 217 Sharp Lab, University of Delaware, Newark, Delaware 19716 (United States)

    2015-08-28

    Photoconductive CdS is known to be n-type and develops high-field domains in the range of negative differential conductivities. These domains have been extensively discussed, and when remaining attached to the electrodes have been renamed Böer domains (a broader definition suggested earlier is misleading) [K. Thiessen, Phys. Status Solidi B 248, 2775 (2011)]. They are occurring at high applied voltage in a range at which the current becomes highly non-ohmic that is conventionally described as N-shaped when the conductance decreases with increasing bias or as S-shaped when the current starts to increase again. In this paper only such cases will be discussed in which the current stays below significant Joule heating (no current channel formation), and only for stationary electrode-attached high-field domains. These are the cathode-attached domains that are maintained by field-quenching and are thermodynamically stable. Their finding is summarized in the first segment of this paper. When the applied voltage is increased, an anode-attached hyper-high-field domain develops that is stabilized by a hole blocking anode and will be analyzed in more detail below. It will be shown that they are a thermodynamically stable p-type photoconductive state of CdS. These two new states can be used to determine the carrier densities and mobilities as function of the field and the effective work function in dependence of the spectral distribution of the optical excitation. In a thin slab adjacent to a blocking cathode, the quasi-Fermi levels are spread to a precise amount and are kept there in the entire high-field region. This opens the opportunity to analyze with small modulation of the excitation the trap transition coefficients near these quasi-Fermi levels separately, without broadening interference from other signals. This has already resulted in the discovery of an unusually sharp electron quenching level when the CdS was in a p-type state with an anode adjacent domain. It is

  12. 76 FR 39283 - Enforcement of Nondiscrimination on the Basis of Handicap in Programs or Activities Conducted by...

    Science.gov (United States)

    2011-07-06

    ... conducted by the agency. For example, auxiliary aids useful for persons with impaired vision include readers... affecting one or more of ] the following body systems: Neurological; musculoskeletal; special sense organs... shall ensure that interested persons, including persons with impaired vision or hearing, can...

  13. A Report on Nursing Information During Volunteer Activities Conducted by Nursing Faculty Members and Students After the Great East Japan Earthquake.

    Science.gov (United States)

    Tomizawa, Yayoi; Ichinose, Makino; Onogi, Hiroshi; Suzuki, Chiaki; Nakamura, Reiko; Misawa, Sumi

    2016-01-01

    A survey was conducted about nursing information in volunteer activities of nursing faculty members and students after the Great East Japan Earthquake. Results indicated that it was important to attempt collecting information in every possible way and to always be prepared. During activities, it is important to record information, to share information with individuals other than nursing professionals and to make good use of it.

  14. State-related differences in the level of psychomotor activity in patients with bipolar disorder

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Maria; Brage, Søren; Vinberg, Maj;

    2016-01-01

    Measuring changes in psychomotor activity is a potential tool in the monitoring of the course of affective states in bipolar disorder. Previous studies have been cross-sectional and only some have used objective measures. The aim was to investigate state-related differences in objectively...

  15. Trends in No Leisure-Time Physical Activity--United States, 1988-2010

    Science.gov (United States)

    Moore, Latetia V.; Harris, Carmen D.; Carlson, Susan A.; Kruger, Judy; Fulton, Janet E.

    2012-01-01

    Purpose: The aim of this study was to examine trends in the prevalence of no leisure-time physical activity (LTPA) from 1988 to 2010. Method: Using the Behavioral Risk Factor Surveillance System data, 35 states and the District of Columbia reported information on no LTPA from 1988 to 1994; all states reported no LTPA from 1996 to 2010. Results: No…

  16. 77 FR 69650 - Agency Information Collection Activities: Holders or Containers Which Enter the United States...

    Science.gov (United States)

    2012-11-20

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Holders or Containers... concerning the Holders or Containers which Enter the United States Duty Free. This request for comment is...: Title: Holders or Containers which Enter the United States Duty Free. OMB Number: 1651-0035. Form...

  17. Apelin-13 inhibits large-conductance Ca2+-activated K+ channels in cerebral artery smooth muscle cells via a PI3-kinase dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Amit Modgil

    Full Text Available Apelin-13 causes vasoconstriction by acting directly on APJ receptors in vascular smooth muscle (VSM cells; however, the ionic mechanisms underlying this action at the cellular level remain unclear. Large-conductance Ca(2+-activated K(+ (BKCa channels in VSM cells are critical regulators of membrane potential and vascular tone. In the present study, we examined the effect of apelin-13 on BK(Ca channel activity in VSM cells, freshly isolated from rat middle cerebral arteries. In whole-cell patch clamp mode, apelin-13 (0.001-1 μM caused concentration-dependent inhibition of BK(Ca in VSM cells. Apelin-13 (0.1 µM significantly decreased BK(Ca current density from 71.25 ± 8.14 pA/pF to 44.52 ± 7.10 pA/pF (n=14 cells, P<0.05. This inhibitory effect of apelin-13 was confirmed by single channel recording in cell-attached patches, in which extracellular application of apelin-13 (0.1 µM decreased the open-state probability (NPo of BK(Ca channels in freshly isolated VSM cells. However, in inside-out patches, extracellular application of apelin-13 (0.1 µM did not alter the NPo of BK(Ca channels, suggesting that the inhibitory effect of apelin-13 on BKCa is not mediated by a direct action on BK(Ca. In whole cell patches, pretreatment of VSM cells with LY-294002, a PI3-kinase inhibitor, markedly attenuated the apelin-13-induced decrease in BK(Ca current density. In addition, treatment of arteries with apelin-13 (0.1 µM significantly increased the ratio of phosphorylated-Akt/total Akt, indicating that apelin-13 significantly increases PI3-kinase activity. Taken together, the data suggest that apelin-13 inhibits BK(Ca channel via a PI3-kinase-dependent signaling pathway in cerebral artery VSM cells, which may contribute to its regulatory action in the control of vascular tone.

  18. Study of the influence of conductivity on the treatment of activated sludges; Estudio de la influencia de la conductividad en tratamientos de lodos activados

    Energy Technology Data Exchange (ETDEWEB)

    Morenilla Martinez, J. J.; Bernacer Bonora, I.; Martinez Muro, M. A.; Sanchez Beltran, A. v.

    2003-07-01

    Summary: The object of the study is to evaluate the influence of conductivity on the treatment of activated sludge, and to discover its impacts on biological activity and the level of purification. The study is designed with short-term tests using re spirometry, and medium-term tests using a pilot plant as a laboratory. Given that re spirometric tests do not cover more than one generation of bacteria, meaning that the effects on cell growth and division do not appear, another round of tests using a pilot plant with a longer duration is proposed. Through the two groups of tests, it was shown that the impact of variations in conductivity on bacteria and protozoa is more pronounced in the case of brusque alterations, even if the levels reached are not high. Nonetheless, conductivity that is apparently very high does not necessarily suppose a worsening of purification conditions, as long as it increases or decreases gradually, or remains constant. (Author) 6 refs.

  19. Encoding of social state information by neuronal activities in the macaque caudate nucleus.

    Science.gov (United States)

    Santos, Gustavo S; Nagasaka, Yasuo; Fujii, Naotaka; Nakahara, Hiroyuki

    2012-01-01

    Social animals adjust their behavior according to social relationships and momentary circumstances. Dominant-submissive relationships modulate, but do not completely determine, their competitive behaviors. For example, a submissive monkey's decision to retrieve food depends not only on the presence of dominant partners but also on their observed behavior. Thus, behavioral expression requires a dynamic evaluation of reward outcome and momentary social states. The neural mechanisms underlying this evaluation remain elusive. The caudate nucleus (CN) plays a pivotal role in representing reward expectation and translating it into action selection. To investigate whether their activities encode social state information, we recorded from CN neurons in monkeys while they performed a competitive food-grab task against a dominant competitor. We found two groups of CN neurons: one primarily responded to reward outcome, while the other primarily tracked the monkey's social state. These social state-dependent neurons showed greater activity when the monkeys freely retrieved food without active challenges from the competitor and reduced activity when the monkeys were in a submissive state due to the competitor's active behavior. These results indicate that different neuronal activities in the CN encode social state information and reward-related information, which may contribute to adjusting competitive behavior in dynamic social contexts.

  20. Pharmacologic inhibition of small-conductance calcium-activated potassium (SK) channels by NS8593 reveals atrial antiarrhythmic potential in horses

    DEFF Research Database (Denmark)

    Haugaard, Maria Mathilde; Hesselkilde, Eva Zander; Pehrson, Steen Michael

    2015-01-01

    BACKGROUND: Small-conductance calcium-activated potassium (SK) channels have been found to play an important role in atrial repolarization and atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to investigate the existence and functional role of SK channels in the equine heart...

  1. 30 CFR 250.201 - What plans and information must I submit before I conduct any activities on my lease or unit?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What plans and information must I submit before I conduct any activities on my lease or unit? 250.201 Section 250.201 Mineral Resources MINERALS... CONTINENTAL SHELF Plans and Information General Information § 250.201 What plans and information must I...

  2. Isotype-specific activation of cystic fibrosis transmembrane conductance regulator-chloride channels by cGMP-dependent protein kinase II

    NARCIS (Netherlands)

    P.J. French (Pim); J. Bijman (Jan); M.J. Edixhoven (Marcel); A.B. Vaandrager (Arie); B.J. Scholte (Bob); S.M. Lohmann (Suzanne); A.C. Nairn; H.R. de Jonge (Hugo)

    1995-01-01

    textabstractType II cGMP-dependent protein kinase (cGKII) isolated from pig intestinal brush borders and type I alpha cGK (cGKI) purified from bovine lung were compared for their ability to activate the cystic fibrosis transmembrane conductance regulator (CFTR)-Cl- channel in excis

  3. Conducting Museum Education Activities within the Context of Developing a Nature Culture in Primary School Students: MTA Natural History Museum Example

    Science.gov (United States)

    Dilli, Rukiye

    2016-01-01

    The present study, aiming to develop nature culture in primary school students and to help them to become acquainted with their close environment, is a quasi-experimental study. Museum education activities were conducted with the study group which consisted of 128 fourth-grade primary school students. At the end of the study, the students gained…

  4. Broadband white light emission from Ce:AlN ceramics: High thermal conductivity down-converters for LED and laser-driven solid state lighting

    Science.gov (United States)

    Wieg, A. T.; Penilla, E. H.; Hardin, C. L.; Kodera, Y.; Garay, J. E.

    2016-12-01

    We introduce high thermal conductivity aluminum nitride (AlN) as a transparent ceramic host for Ce3+, a well-known active ion dopant. We show that the Ce:AlN ceramics have overlapping photoluminescent (PL) emission peaks that cover almost the entire visible range resulting in a white appearance under 375 nm excitation without the need for color mixing. The PL is due to a combination of intrinsic AlN defect complexes and Ce3+ electronic transitions. Importantly, the peak intensities can be tuned by varying the Ce concentration and processing parameters, causing different shades of white light without the need for multiple phosphors or light sources. The Commission Internationale de l'Eclairage coordinates calculated from the measured spectra confirm white light emission. In addition, we demonstrate the viability of laser driven white light emission by coupling the Ce:AlN to a readily available frequency tripled Nd-YAG laser emitting at 355 nm. The high thermal conductivity of these ceramic down-converters holds significant promise for producing higher power white light sources than those available today.

  5. Broadband white light emission from Ce:AlN ceramics: High thermal conductivity down-converters for LED and laser-driven solid state lighting

    Directory of Open Access Journals (Sweden)

    A. T. Wieg

    2016-12-01

    Full Text Available We introduce high thermal conductivity aluminum nitride (AlN as a transparent ceramic host for Ce3+, a well-known active ion dopant. We show that the Ce:AlN ceramics have overlapping photoluminescent (PL emission peaks that cover almost the entire visible range resulting in a white appearance under 375 nm excitation without the need for color mixing. The PL is due to a combination of intrinsic AlN defect complexes and Ce3+ electronic transitions. Importantly, the peak intensities can be tuned by varying the Ce concentration and processing parameters, causing different shades of white light without the need for multiple phosphors or light sources. The Commission Internationale de l’Eclairage coordinates calculated from the measured spectra confirm white light emission. In addition, we demonstrate the viability of laser driven white light emission by coupling the Ce:AlN to a readily available frequency tripled Nd-YAG laser emitting at 355 nm. The high thermal conductivity of these ceramic down-converters holds significant promise for producing higher power white light sources than those available today.

  6. A STATE AS AN ACTIVATOR OF SCIENTIFIC, TECHNICAL AND INNOVATION ACTIVITIES

    Directory of Open Access Journals (Sweden)

    O. Zhylinska

    2013-03-01

    Full Text Available Modern mechanisms and instruments of state regulation of science, technology and innovation are systematized from the point of view of market failures overcoming in these areas of the economy.

  7. Resting-state hemodynamics are spatiotemporally coupled to synchronized and symmetric neural activity in excitatory neurons.

    Science.gov (United States)

    Ma, Ying; Shaik, Mohammed A; Kozberg, Mariel G; Kim, Sharon H; Portes, Jacob P; Timerman, Dmitriy; Hillman, Elizabeth M C

    2016-12-27

    Brain hemodynamics serve as a proxy for neural activity in a range of noninvasive neuroimaging techniques including functional magnetic resonance imaging (fMRI). In resting-state fMRI, hemodynamic fluctuations have been found to exhibit patterns of bilateral synchrony, with correlated regions inferred to have functional connectivity. However, the relationship between resting-state hemodynamics and underlying neural activity has not been well established, making the neural underpinnings of functional connectivity networks unclear. In this study, neural activity and hemodynamics were recorded simultaneously over the bilateral cortex of awake and anesthetized Thy1-GCaMP mice using wide-field optical mapping. Neural activity was visualized via selective expression of the calcium-sensitive fluorophore GCaMP in layer 2/3 and 5 excitatory neurons. Characteristic patterns of resting-state hemodynamics were accompanied by more rapidly changing bilateral patterns of resting-state neural activity. Spatiotemporal hemodynamics could be modeled by convolving this neural activity with hemodynamic response functions derived through both deconvolution and gamma-variate fitting. Simultaneous imaging and electrophysiology confirmed that Thy1-GCaMP signals are well-predicted by multiunit activity. Neurovascular coupling between resting-state neural activity and hemodynamics was robust and fast in awake animals, whereas coupling in urethane-anesthetized animals was slower, and in some cases included lower-frequency (neural activity. The patterns of bilaterally-symmetric spontaneous neural activity revealed by wide-field Thy1-GCaMP imaging may depict the neural foundation of functional connectivity networks detected in resting-state fMRI.

  8. Role of calcium-activated potassium channels with small conductance in bradykinin-induced vasodilation of porcine retinal arterioles

    DEFF Research Database (Denmark)

    Dalsgaard, Thomas; Kroigaard, Christel; Bek, Toke

    2009-01-01

    (Ca)) conductance are involved in regulation of endothelium-dependent vasodilation in retinal arterioles was investigated. METHODS: Porcine retinal arterioles (diameter approximately 112 microm, N = 119) were mounted in microvascular myographs for isometric tension recordings. The arterioles were contracted......(Ca) channels contribute to NO-mediated relaxation induced by bradykinin and NS309 and, hence, may play an important role in retinal arterial endothelial function....

  9. Decreased electrophysiological activity represents the conscious state of emptiness in meditation.

    Science.gov (United States)

    Hinterberger, Thilo; Schmidt, Stephanie; Kamei, Tsutomu; Walach, Harald

    2014-01-01

    Many neuroscientific theories explain consciousness with higher order information processing corresponding to an activation of specific brain areas and processes. In contrast, most forms of meditation ask for a down-regulation of certain mental processing activities while remaining fully conscious. To identify the physiological properties of conscious states with decreased mental and cognitive processing, the electrical brain activity (64 channels of EEG) of 50 participants of various meditation proficiencies was measured during distinct and idiosyncratic meditative tasks. The tasks comprised a wakeful "thoughtless emptiness (TE)," a "focused attention," and an "open monitoring" task asking for mindful presence in the moment and in the environment without attachment to distracting thoughts. Our analysis mainly focused on 30 highly experienced meditators with at least 5 years and 1000 h of meditation experience. Spectral EEG power comparisons of the TE state with the resting state or other forms of meditation showed decreased activities in specific frequency bands. In contrast to a focused attention task the TE task showed significant central and parietal gamma decreases (p waves than a wakeful closed eyes resting condition. A group of participants with none or little meditation practice did not present those differences significantly. Our findings indicate that a conscious state of TE reached by experienced meditators is characterized by reduced high-frequency brain processing with simultaneous reduction of the low frequencies. This suggests that such a state of meditative conscious awareness might be different from higher cognitive and mentally focused states but also from states of sleep and drowsiness.

  10. Decreased Electrophysiological Activity Represents the Conscious State of Emptiness in Meditation

    Directory of Open Access Journals (Sweden)

    Thilo eHinterberger

    2014-02-01

    Full Text Available Many neuroscientific theories explain consciousness with higher order information processing corresponding to an activation of specific brain areas and processes. In contrast, most forms of meditation ask for a down-regulation of certain mental processing activities while remaining fully conscious. To identify the physiological properties of conscious states with decreased mental and cognitive processing, the electrical brain activity (64 channels of EEG of 50 participants of various meditation proficiencies was measured during distinct and idiosyncratic meditative tasks. The tasks comprised a wakeful ‘thoughtless emptiness (TE’, a ‘focused attention’, and an ‘open monitoring’ task asking for mindful presence in the moment and in the environment without attachment to distracting thoughts. Our analysis mainly focused on 30 highly experienced meditators with at least 5 years and 1000 hours of meditation experience.Spectral EEG power comparisons of the TE state with the resting state or other forms of meditation showed decreased activities in specific frequency bands. In contrast to a focused attention task the TE task showed significant central and parietal gamma decreases (pOur findings indicate that a conscious state of thoughtless emptiness reached by experienced meditators is characterized by reduced high-frequency brain processing with simultaneous reduction of the low frequencies. This suggests that such a state of meditative conscious awareness might be different from higher cognitive and mentally focused states but also from states of sleep and drowsiness.

  11. The steady-state dipole-flow test for characterization of hydraulic conductivity statistics in a highly permeable aquifer: Horkheimer Insel site, Germany.

    Science.gov (United States)

    Zlotnik, V A; Zurbuchen, B R; Ptak, T

    2001-01-01

    Over the last decade the dipole-flow test (DFT) evolved from the general idea of using recirculatory flow to evaluate aquifer properties, to the development of prototype instrumentation and feasibility studies, to a reliable tool for characterization of aquifer heterogeneity. The DFT involves the interpretation of head in recirculatory flow between injection and extraction sections (chambers) in a single well isolated from each other by a multipacker system. In this study, the steady-state dipole flow test (DFT) has been used to characterize the statistics of horizontal hydraulic conductivity (Kr) of the highly permeable, heterogeneous, and thin aquifer at the Horkheimer Insel site, Germany. In previous studies, Kr estimates were based on the steady-state head difference between chambers. A new by-chamber interpretation is proposed that is based on drawdown within each individual chamber. This interpretation yields more detailed information on structure of heterogeneity of the aquifer without introducing complexity into the analysis. The DFT results indicate that Kr ranges from 49 to 6000 m/day (mean ln Kr [(m/s)] approximately -4, and variance of ln Kr [(m/s)] approximately 1-2). Descriptive statistics from the DFT compare well with those from previous field and laboratory tests (pumping, borehole flowmeter, and permeameter tests and grain-size analysis) at this site. It is shown that the role of confining boundaries in the DFT interpretation is negligible even in this case of a thin (< 4 m thick) aquifer. This study demonstrates the flexibility of the DFT and expands the potential application of this method to a wide range of hydrogeologic settings.

  12. Hierarchical Model-Based Activity Recognition With Automatic Low-Level State Discovery

    Directory of Open Access Journals (Sweden)

    Justin Muncaster

    2007-09-01

    Full Text Available Activity recognition in video streams is increasingly important for both the computer vision and artificial intelligence communities. Activity recognition has many applications in security and video surveillance. Ultimately in such applications one wishes to recognize complex activities, which can be viewed as combination of simple activities. In this paper, we present a general framework of a Dlevel dynamic Bayesian network to perform complex activity recognition. The levels of the network are constrained to enforce state hierarchy while the Dth level models the duration of simplest event. Moreover, in this paper we propose to use the deterministic annealing clustering method to automatically define the simple activities, which corresponds to the low level states of observable levels in a Dynamic Bayesian Networks. We used real data sets for experiments. The experimental results show the effectiveness of our proposed method.

  13. Calcium-activated potassium conductances contribute to action potential repolarization at the soma but not the dendrites of hippocampal CA1 pyramidal neurons.

    Science.gov (United States)

    Poolos, N P; Johnston, D

    1999-07-01

    Evidence is accumulating that voltage-gated channels are distributed nonuniformly throughout neurons and that this nonuniformity underlies regional differences in excitability within the single neuron. Previous reports have shown that Ca2+, Na+, A-type K+, and hyperpolarization-activated, mixed cation conductances have varying distributions in hippocampal CA1 pyramidal neurons, with significantly different densities in the apical dendrites compared with the soma. Another important channel mediates the large-conductance Ca2+-activated K+ current (IC), which is responsible in part for repolarization of the action potential (AP) and generation of the afterhyperpolarization that follows the AP recorded at the soma. We have investigated whether this current is activated by APs retrogradely propagating in the dendrites of hippocampal pyramidal neurons using whole-cell dendritic patch-clamp recording techniques. We found no IC activation by back-propagating APs in distal dendritic recordings. Dendritic APs activated IC only in the proximal dendrites, and this activation decayed within the first 100-150 micrometer of distance from the soma. The decay of IC in the proximal dendrites occurred despite AP amplitude, plus presumably AP-induced Ca2+ influx, that was comparable with that at the soma. Thus we conclude that IC activation by action potentials is nonuniform in the hippocampal pyramidal neuron, which may represent a further example of regional differences in neuronal excitability that are determined by the nonuniform distribution of voltage-gated channels in dendrites.

  14. Decreased electrophysiological activity represents the conscious state of emptiness in meditation

    OpenAIRE

    Thilo eHinterberger; Stephanie eSchmidt; Tsutomu eKamei; Harald eWalach

    2014-01-01

    Many neuroscientific theories explain consciousness with higher order information processing corresponding to an activation of specific brain areas and processes. In contrast, most forms of meditation ask for a down-regulation of certain mental processing activities while remaining fully conscious. To identify the physiological properties of conscious states with decreased mental and cognitive processing, the electrical brain activity (64 channels of EEG) of 50 participants of various meditat...

  15. Survey design and observations relating to cancer education funding. Cancer Education Survey II: cancer education in United States medical schools (conducted by The American Association for Cancer Education with the support of the American Cancer Society).

    Science.gov (United States)

    Bakemeier, R F; Kupchella, C E; Chamberlain, R M; Gallagher, R E; O'Donnell, J F; Parker, J A; Hill, G J; Brooks, C M

    1992-01-01

    A survey has been conducted of cancer education programs for medical students in United States medical schools by the American Association for Cancer Education with grant support from the Department of Detection and Treatment of the American Cancer Society (formerly the Professional Education Department). Two questionnaires were used, an Educational Resources Questionnaire (ERQ), which 126 of the 128 medical schools completed and returned, and a Faculty and Curriculum Questionnaire (FCQ), which was completed and returned by 1,035 faculty members who had been named as active in undergraduate medical student cancer education by respondents in each school who had been designated by the Dean's Office to complete the ERQ. Overall conclusions included: (1) increased coordination of cancer education activities is a major need in many schools; (2) there is widespread interest in the further development of cancer education objectives; (3) development of a national cancer education curriculum is needed; (4) there is interest in the development of improved instructional materials and methods; (5) development of evaluation methods is needed for cancer education programs; and (6) an ongoing funding process is needed to provide support for interdepartmental coordination of cancer education activities. Cancer prevention and detection topics were ranked above cancer treatment in plans for future curriculum emphasis. More detailed conclusions and recommendations are provided in this publication and three subsequent articles in this issue of the Journal of Cancer Education.

  16. Electrical Conductivity.

    Science.gov (United States)

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  17. Synthesis and ionic conductivity of Li6La3BiSnO12 with cubic garnet-type structure via solid-state reaction

    Institute of Scientific and Technical Information of China (English)

    彭红建; 肖理红; 曹远尼; 栾向峰

    2015-01-01

    The synthesis and transport properties of the Li6La3BiSnO12 solid electrolyte by a solid-state reaction were reported. The condition to synthesize the Li6La3BiSnO12 is 785 °C for 36 h in air. The refinedlattice constant of Li6La3BiSnO12is 13.007 Å. Qualitative phase analysis by X-ray powder diffraction patterns combined with the Rietveld method reveals garnet type compounds as major phases. The Li-ion conductivity of the prepared Li6La3BiSnO12 is 0.85×10−4 S/cm at 22 °C, which is comparable with that of the Li5La3Bi2O12. The Li6La3BiSnO12compounds are chemically stable against LiCoO2 which is widely used as cathode material up to 700 °C but not against the LiMn2O4 if the temperature is higher than 550 °C. The Li6La3BiSnO12exhibitshigher chemical stability than Li5La3Bi2O12, which is due to Sn substitution for Bi.

  18. Characterisation of a cell swelling-activated K+-selective conductance of Ehrlich mouse ascites tumour cells

    DEFF Research Database (Denmark)

    Niemeyer, María Isabel; Hougaard, Charlotte; Hoffmann, Else Kay

    2000-01-01

    1.  The K+ and Cl- currents activated by hypotonic cell swelling were studied in Ehrlich ascites tumour cells using the whole-cell recording mode of the patch-clamp technique. 2.  Currents were measured in the absence of added intracellular Ca2+ and with strong buffering of Ca2+. K+ current...... activated by cell swelling was measured as outward current at the Cl- equilibrium potential (ECl) under quasi-physiological gradients. It could be abolished by replacing extracellular Na+ with K+, thereby cancelling the driving force. Replacement with other cations suggested a selectivity sequence of K...

  19. Brain activation, affect, and aerobic exercise: an examination of both state-independent and state-dependent relationships.

    Science.gov (United States)

    Petruzzello, S J; Tate, A K

    1997-09-01

    Resting electroencephalograph (EEG) asymmetry is a biological marker of the propensity to respond affectively to, and a measure of change in affect associated with, acute aerobic exercise. This study examined the EEG-affect-exercise relationship. Twenty participants performed each of three randomly assigned 30-min conditions: (a) a nonexercise control, (b) a cycling exercise at 55% VO2max, and (c) a cycling exercise at 70% VO2max. EEG and affect were assessed pre- and 0, 5, 10, 20, and 30 min postcondition. No significant results were seen in the control or 55% conditions. In the 70% exercise condition, greater relative left frontal activation preexercise predicted increased positive affect and reduced state anxiety postexercise. Participants (n = 7) with extreme relative left frontal activation postexercise reported concomitant decreases in anxiety, whereas participants (n = 7) with extreme relative right frontal activation postexercise reported increases in anxiety. These findings (a) replicate prior work, (b) suggest a dose-response intensity effect, and (c) support the idea that exercise is an emotion-eliciting event. Affective responses seem to be mediated in part by differential resting levels of activation in the anterior brain regions. Ongoing anterior brain activation reflected concurrent postexercise affect.

  20. Membrane targeting of cGMP-dependent protein kinase is required for cystic fibrosis transmembrane conductance regulator Cl- channel activation

    NARCIS (Netherlands)

    A.B. Vaandrager (Arie); A. Smolenski; B.C. Tilly (Bernard); A.B. Houtsmuller (Adriaan); E.M.E. Ehlert (Ehrich); A.G. Bot (Alice); M.J. Edixhoven (Marcel); W.E. Boomaars (Wendy); S.M. Lohmann (Suzanne); H.R. de Jonge (Hugo)

    1998-01-01

    textabstractA recently cloned isoform of cGMP-dependent protein kinase (cGK), designated type II, was implicated as the mediator of cGMP-provoked intestinal Cl- secretion based on its localization in the apical membrane of enterocytes and on its capacity to activate cys

  1. 75 FR 5575 - Taking and Importing Marine Mammals; Navy Training Activities Conducted in the Gulf of Alaska

    Science.gov (United States)

    2010-02-03

    ... for the development and implementation of regulations governing the incidental taking of marine... beaked whales (of any of the following species: Baird's beaked whale, Cuvier's beaked whale, Stejneger's beaked whale) annually by serious injury or mortality. Specified Activities In the application...

  2. The mitochondrial complex I activity is reduced in cells with impaired cystic fibrosis transmembrane conductance regulator (CFTR function.

    Directory of Open Access Journals (Sweden)

    Angel G Valdivieso

    Full Text Available Cystic fibrosis (CF is a frequent and lethal autosomal recessive disease. It results from different possible mutations in the CFTR gene, which encodes the CFTR chloride channel. We have previously studied the differential expression of genes in CF and CF corrected cell lines, and found a reduced expression of MTND4 in CF cells. MTND4 is a mitochondrial gene encoding the MTND4 subunit of the mitochondrial Complex I (mCx-I. Since this subunit is essential for the assembly and activity of mCx-I, we have now studied whether the activity of this complex was also affected in CF cells. By using Blue Native-PAGE, the in-gel activity (IGA of the mCx-I was found reduced in CFDE and IB3-1 cells (CF cell lines compared with CFDE/6RepCFTR and S9 cells, respectively (CFDE and IB3-1 cells ectopically expressing wild-type CFTR. Moreover, colon carcinoma T84 and Caco-2 cells, which express wt-CFTR, either treated with CFTR inhibitors (glibenclamide, CFTR(inh-172 or GlyH101 or transfected with a CFTR-specific shRNAi, showed a significant reduction on the IGA of mCx-I. The reduction of the mCx-I activity caused by CFTR inhibition under physiological or pathological conditions may have a profound impact on mitochondrial functions of CF and non-CF cells.

  3. Research activity on NaxCoO2 single crystals: A brief review on optical conductivity and metamagnetic transition phenomenon

    Directory of Open Access Journals (Sweden)

    N.L. Wang and J.L. Luo

    2005-01-01

    Full Text Available NaxCoO2 material is of great interest because of its rich electronic phase diagram, as well as for displaying superconductivity when intercalated with water. This paper briefly reviews our research activity on its optical properties and a metamagnetic transition phenomenon.

  4. Use of alpha spectroscopy for conducting rapid surveys of transuranic activity on air sample filters and smears.

    Science.gov (United States)

    Hayes, Robert B; Peña, Adan M; Goff, Thomas E

    2005-08-01

    This paper demonstrates the utility of a portable alpha Continuous Air Monitor (CAM) as a bench top scalar counter for multiple sample types. These include using the CAM to count fixed air sample filters and radiological smears. In counting radiological smears, the CAM is used very much like a gas flow proportional counter (GFPC), albeit with a lower efficiency. Due to the typically low background in this configuration, the minimum detectable activity for a 5-min count should be in the range of about 10 dpm which is acceptably below the 20 dpm limit for transuranic isotopes. When counting fixed air sample filters, the CAM algorithm along with other measurable characteristics can be used to identify and quantify the presence of transuranic isotopes in the samples. When the radiological control technician wants to take some credit from naturally occurring radioactive material contributions due to radon progeny producing higher energy peaks (as in the case with a fixed air sample filter), then more elaborate techniques are required. The techniques presented here will generate a decision level of about 43 dpm for such applications. The calibration for this application should alternatively be done using the default values of channels 92-126 for region of interest 1. This can be done within 10 to 15 min resulting in a method to rapidly evaluate air filters for transuranic activity. When compared to the 1-h count technique described by , the technique presented in the present work demonstrates a technique whereby more than two thirds of samples can be rapidly shown (within 10 to 15 min) to be within regulatory compliant limits. In both cases, however, spectral quality checks are required to insure sample self attenuation is not a significant bias in the activity estimates. This will allow the same level of confidence when using these techniques for activity quantification as is presently available for air monitoring activity quantification using CAMs.

  5. Time-lapse three-dimensional inversion of complex conductivity data using an active time constrained (ATC) approach

    Science.gov (United States)

    Karaoulis, M.; Revil, A.; Werkema, D.D.; Minsley, B.J.; Woodruff, W.F.; Kemna, A.

    2011-01-01

    Induced polarization (more precisely the magnitude and phase of impedance of the subsurface) is measured using a network of electrodes located at the ground surface or in boreholes. This method yields important information related to the distribution of permeability and contaminants in the shallow subsurface. We propose a new time-lapse 3-D modelling and inversion algorithm to image the evolution of complex conductivity over time. We discretize the subsurface using hexahedron cells. Each cell is assigned a complex resistivity or conductivity value. Using the finite-element approach, we model the in-phase and out-of-phase (quadrature) electrical potentials on the 3-D grid, which are then transformed into apparent complex resistivity. Inhomogeneous Dirichlet boundary conditions are used at the boundary of the domain. The calculation of the Jacobian matrix is based on the principles of reciprocity. The goal of time-lapse inversion is to determine the change in the complex resistivity of each cell of the spatial grid as a function of time. Each model along the time axis is called a 'reference space model'. This approach can be simplified into an inverse problem looking for the optimum of several reference space models using the approximation that the material properties vary linearly in time between two subsequent reference models. Regularizations in both space domain and time domain reduce inversion artefacts and improve the stability of the inversion problem. In addition, the use of the time-lapse equations allows the simultaneous inversion of data obtained at different times in just one inversion step (4-D inversion). The advantages of this new inversion algorithm are demonstrated on synthetic time-lapse data resulting from the simulation of a salt tracer test in a heterogeneous random material described by an anisotropic semi-variogram. ?? 2011 The Authors Geophysical Journal International ?? 2011 RAS.

  6. Structure of a potentially open state of a proton-activated pentameric ligand-gated ion channel.

    Science.gov (United States)

    Hilf, Ricarda J C; Dutzler, Raimund

    2009-01-01

    The X-ray structure of a pentameric ligand-gated ion channel from Erwinia chrysanthemi (ELIC) has recently provided structural insight into this family of ion channels at high resolution. The structure shows a homo-pentameric protein with a barrel-stave architecture that defines an ion-conduction pore located on the fivefold axis of symmetry. In this structure, the wide aqueous vestibule that is encircled by the extracellular ligand-binding domains of the five subunits narrows to a discontinuous pore that spans the lipid bilayer. The pore is constricted by bulky hydrophobic residues towards the extracellular side, which probably serve as barriers that prevent the diffusion of ions. This interrupted pore architecture in ELIC thus depicts a non-conducting conformation of a pentameric ligand-gated ion channel, the thermodynamically stable state in the absence of bound ligand. As ligand binding promotes pore opening in these ion channels and the specific ligand for ELIC has not yet been identified, we have turned our attention towards a homologous protein from the cyanobacterium Gloebacter violaceus (GLIC). GLIC was shown to form proton-gated channels that are activated by a pH decrease on the extracellular side and that do not desensitize after activation. Both prokaryotic proteins, ELIC and GLIC form ion channels that are selective for cations over anions with poor discrimination among monovalent cations, characteristics that resemble the conduction properties of the cation-selective branch of the family that includes acetylcholine and serotonin receptors. Here we present the X-ray structure of GLIC at 3.1 A resolution. The structure reveals a conformation of the channel that is distinct from ELIC and that probably resembles the open state. In combination, both structures suggest a novel gating mechanism for pentameric ligand-gated ion channels where channel opening proceeds by a change in the tilt of the pore-forming helices.

  7. Sports Management Faculty External Grant-Writing Activities in the United States

    Science.gov (United States)

    DeVinney, Timothy P.

    2012-01-01

    This study was conducted to fill a void in information, provide relevant, current data for faculty members related to external grant-writing activities related to the academic field of sport management and serve as a tool that may aid in the advancement of external grant-writing efforts within the field of sport management. All data is specific to…

  8. Report to the Department of Energy on the DOE/EPSCoR planning activities for the state of South Dakota

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    An extensive review of the current status of energy-related research and educational activities within the state of South Dakota was carried out. Information exchange meetings were conducted at the major research institutions as well as with many representatives of state government. Visits were also made to professional educators who are deeply involved with the state`s principal minority group, the American Indian. Several activities in the human resource development area that will be carried out in the five-year implementation project were identified. Many of these will be closely coordinated with other efforts currently in progress under the auspices of the NSF SSI (Statewide Systemic Initiatives in Science, Mathematics, and Engineering Education) office. The authors will also work closely with AWU and other regional consortia to foster a higher level of participation in existing DOE programs and to develop adaptations and {open_quotes}follow-ons{close_quotes} that are tailored to the specific needs of South Dakota. Many of these programs will involve extensive interaction with DOE laboratories. Special programs will be carried out that are designed to keep a larger number of the Native American population in the science and engineering pipeline. An assessment of the research strengths of this state was made. With the assistance of external consultants, the authors identified two principal areas in which they have the potential to develop nationally competitive research programs that fall within DOE objectives. One is a comprehensive biomass systems study, and the other a water quality study as it relates to energy production.

  9. Effects of long-term acupuncture treatment on resting-state brain activity in migraine patients: a randomized controlled trial on active acupoints and inactive acupoints.

    Directory of Open Access Journals (Sweden)

    Ling Zhao

    Full Text Available BACKGROUND: Acupuncture has been commonly used for preventing migraine attacks and relieving pain during a migraine, although there is limited knowledge on the physiological mechanism behind this method. The objectives of this study were to compare the differences in brain activities evoked by active acupoints and inactive acupoints and to investigate the possible correlation between clinical variables and brain responses. METHODS AND RESULTS: A randomized controlled trial and resting-state functional magnetic resonance imaging (fMRI were conducted. A total of eighty migraineurs without aura were enrolled to receive either active acupoint acupuncture or inactive acupoint acupuncture treatment for 8 weeks, and twenty patients in each group were randomly selected for the fMRI scan at the end of baseline and at the end of treatment. The neuroimaging data indicated that long-term active acupoint therapy elicited a more extensive and remarkable cerebral response compared with acupuncture at inactive acupoints. Most of the regions were involved in the pain matrix, lateral pain system, medial pain system, default mode network, and cognitive components of pain processing. Correlation analysis showed that the decrease in the visual analogue scale (VAS was significantly related to the increased average Regional homogeneity (ReHo values in the anterior cingulate cortex in the two groups. Moreover, the decrease in the VAS was associated with increased average ReHo values in the insula which could be detected in the active acupoint group. CONCLUSIONS: Long-term active acupoint therapy and inactive acupoint therapy have different brain activities. We postulate that acupuncture at the active acupoint might have the potential effect of regulating some disease-affected key regions and the pain circuitry for migraine, and promote establishing psychophysical pain homeostasis. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TRC-13003635.

  10. Effect of particle size on dc conductivity, activation energy and diffusion coefficient of lithium iron phosphate in Li-ion cells

    Directory of Open Access Journals (Sweden)

    T.V.S.L. Satyavani

    2016-03-01

    Full Text Available Cathode materials in nano size improve the performance of batteries due to the increased reaction rate and short diffusion lengths. Lithium Iron Phosphate (LiFePO4 is a promising cathode material for Li-ion batteries. However, it has its own limitations such as low conductivity and low diffusion coefficient which lead to high impedance due to which its application is restricted in batteries. In the present work, increase of conductivity with decreasing particle size of LiFePO4/C is studied. Also, the dependence of conductivity and activation energy for hopping of small polaron in LiFePO4/C on variation of particle size is investigated. The micro sized cathode material is ball milled for different durations to reduce the particle size to nano level. The material is characterized for its structure and particle size. The resistivities/dc conductivities of the pellets are measured using four probe technique at different temperatures, up to 150 °C. The activation energies corresponding to different particle sizes are calculated using Arrhenius equation. CR2032 cells are fabricated and electrochemical characteristics, namely, ac impedance and diffusion coefficients, are studied.

  11. Structure of a nanobody-stabilized active state of the β(2) adrenoceptor

    DEFF Research Database (Denmark)

    Rasmussen, Søren Gøgsig Faarup; Choi, Hee-Jung; Fung, Juan Jose;

    2011-01-01

    G protein coupled receptors (GPCRs) exhibit a spectrum of functional behaviours in response to natural and synthetic ligands. Recent crystal structures provide insights into inactive states of several GPCRs. Efforts to obtain an agonist-bound active-state GPCR structure have proven difficult due...... to the inherent instability of this state in the absence of a G protein. We generated a camelid antibody fragment (nanobody) to the human β(2) adrenergic receptor (β(2)AR) that exhibits G protein-like behaviour, and obtained an agonist-bound, active-state crystal structure of the receptor-nanobody complex....... Comparison with the inactive β(2)AR structure reveals subtle changes in the binding pocket; however, these small changes are associated with an 11 Å outward movement of the cytoplasmic end of transmembrane segment 6, and rearrangements of transmembrane segments 5 and 7 that are remarkably similar to those...

  12. Steady state of active systems is characterized by unique effective temperature

    CERN Document Server

    Nandi, Saroj Kumar

    2016-01-01

    Understanding the properties of active matter systems, consisting of particles capable of taking up and dissipating energy and thus driven out of equilibrium, is important as it provides the possibility of a unified framework to analyze a diverse class of biological systems. Analysis of a large number of such systems shows an extension of equilibrium-like ideas are, sometimes, capable of capturing the steady state properties and a thermodynamic formulation of the problem might be possible. Investigating the detailed steady state properties and how the systems depart from equilibrium is important for such a formulation. Here we address the question through the framework of mode-coupling theory for dense active systems. We obtain a generic nonequilirbium theory for such systems and then taking the steady state limit of the theory we show that the system is characterized by a unique effective temperature, unlike other driven systems like a glass under shear. We discuss the differences of the steady states of an ...

  13. Regulation to create environments conducive to physical activity: understanding the barriers and facilitators at the Australian state government level.

    Directory of Open Access Journals (Sweden)

    Jane Shill

    Full Text Available INTRODUCTION: Policy and regulatory interventions aimed at creating environments more conducive to physical activity (PA are an important component of strategies to improve population levels of PA. However, many potentially effective policies are not being broadly implemented. This study sought to identify potential policy/regulatory interventions targeting PA environments, and barriers/facilitators to their implementation at the Australian state/territory government level. METHODS: In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organisations (n = 40 to examine participants': 1 suggestions for regulatory interventions to create environments more conducive to PA; 2 support for preselected regulatory interventions derived from a literature review. Thematic and constant comparative analyses were conducted. RESULTS: POLICY INTERVENTIONS MOST COMMONLY SUGGESTED BY PARTICIPANTS FELL INTO TWO AREAS: 1 urban planning and provision of infrastructure to promote active travel; 2 discouraging the use of private motorised vehicles. Of the eleven preselected interventions presented to participants, interventions relating to walkability/cycling and PA facilities received greatest support. Interventions involving subsidisation (of public transport, PA-equipment and the provision of more public transport infrastructure received least support. These were perceived as not economically viable or unlikely to increase PA levels. Dominant barriers were: the powerful 'road lobby', weaknesses in the planning system and the cost of potential interventions. Facilitators were: the provision of evidence, collaboration across sectors, and synergies with climate change/environment agendas. CONCLUSION: This study points to how difficult it will be to achieve policy change when there is a powerful 'road lobby' and government investment prioritises road infrastructure over PA

  14. [Relationship among soil enzyme activities, vegetation state, and soil chemical properties of coal cinder yard].

    Science.gov (United States)

    Wang, Youbao; Zhang, Li; Liu, Dengyi

    2003-01-01

    From field investigation and laboratory analysis, the relationships among soil enzyme activities, vegetation state and soil chemical properties of coal cinder yard in thermal power station were studied. The results showed that vegetation on coal cinder yard was distributed in scattered patch mainly with single species of plant, and herbs were the dominant species. At the same time, the activity of three soil enzymes had a stronger relativity to environment conditions, such as vegetation state and soil chemical properties. The sensitivity of three soil enzymes to environmental stress was in order of urease > sucrase > catalase. The relativity of three soil enzymes to environmental factor was in order of sucrase > urease > catalase. Because of urease being the most susceptible enzyme to environmental conditions, and it was marked or utmost marked interrelated with vegetation state and soil chemical properties, urease activity could be used as an indicator for the reclamation of wasteland.

  15. Two distinct pools of large-conductance calcium-activated potassium channels in the somatic plasma membrane of central principal neurons

    OpenAIRE

    Kaufmann, W.A.; Kasugai, Y.; Ferraguti, F.; Storm, J F

    2010-01-01

    Although nerve cell membranes are often assumed to be uniform with respect to electrical properties, there is increasing evidence for compartmentalization into subdomains with heterogeneous impacts on the overall cell function. Such microdomains are characterized by specific sets of proteins determining their functional properties. Recently, clustering of large-conductance calcium-activated potassium (BKCa) channels was shown at sites of subsurface membrane cisterns in cerebellar Purkinje cel...

  16. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    Science.gov (United States)

    Panitz, Janda K.; Reed, Scott T.; Ashley, Carol S.; Neiser, Richard A.; Moffatt, William C.

    1999-01-01

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties.

  17. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    Energy Technology Data Exchange (ETDEWEB)

    Panitz, J.K.; Reed, S.T.; Ashley, C.S.; Neiser, R.A.; Moffatt, W.C.

    1999-07-20

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties. 6 figs.

  18. Multi-dimensional construction of a novel active yolk@conductive shell nanofiber web as a self-standing anode for high-performance lithium-ion batteries.

    Science.gov (United States)

    Liu, Hao; Chen, Luyi; Liang, Yeru; Fu, Ruowen; Wu, Dingcai

    2015-12-21

    A novel active yolk@conductive shell nanofiber web with a unique synergistic advantage of various hierarchical nanodimensional objects including the 0D monodisperse SiO2 yolks, the 1D continuous carbon shell and the 3D interconnected non-woven fabric web has been developed by an innovative multi-dimensional construction method, and thus demonstrates excellent electrochemical properties as a self-standing LIB anode.

  19. Chronic salt-loading downregulates large-conductance Ca~(2+)-activated potassium channel in mesenteric arterial smooth muscle cells from SD rats

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective Large-conductance calcium-activated potassium(BKCa)channel modulates vascular smooth muscle tone.In the present study,we tested the hypothesis that salt,one of the factors which significantly influence blood pressure(BP),can regulate BKCa activity and then elevate blood pressure.Methods Male Sprague-Dawley rats aged 6 weeks were randomized into high salt diet group(HS)and control group,fed with high salt diet(containing 5% NaCl)and standard rat chow(containing 0.4% NaCl)respectively for 16 weeks.T...

  20. A pilot study on conducting mobile learning activities for clinical nursing courses based on the repertory grid approach.

    Science.gov (United States)

    Wu, Po-Han; Hwang, Gwo-Jen; Tsai, Chin-Chung; Chen, Ya-Chun; Huang, Yueh-Min

    2011-11-01

    In clinical nursing courses, students are trained to identify the status of the target patients. The mastery of such ability and skills is very important since patients frequently need to be cared for immediately. In this pilot study, a repertory grid-oriented clinical mobile learning system is developed for a nursing training program. With the assistance of the mobile learning system, the nursing school students are able to learn in an authentic learning scenario, in which they can physically face the target patients, with the personal guidance and supplementary materials from the learning system to support them. To show the effectiveness of this innovative approach, an experiment has been conducted on the "respiratory system" unit of a nursing course. The experimental results show that the innovative approach is helpful to students in improving their learning achievements. Moreover, from the questionnaire surveys, it was found that most students showed favorable attitudes toward the usage of the mobile learning system and their participation in the training program.

  1. Folate Protects Hepatocytes of Hyperhomocysteinemia Mice from Apoptosis via Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)-activated Endoplasmic Reticulum Stress.

    Science.gov (United States)

    Yang, Anning; Sun, Yue; Mao, Caiyan; Yang, Songhao; Huang, Min; Deng, Mei; Ding, Ning; Yang, Xiaoling; Zhang, Minghao; Jin, Shaoju; Jiang, Yideng; Huang, Ying

    2017-02-23

    Folate deficiency is a known risk factor for liver injury; however, the underlying mechanism remains unclear. In this study, we employed a high homocysteine-induced liver injury model of Apolipoprotein E-deficient (ApoE(-/-) ) mice fed high-methionine diet and found that high homocysteine induced endoplasmic reticulum (ER) stress and liver cell apoptosis by downregulation of cystic fibrosis transmembrane conductance regulator (CFTR) expression; observations that were attenuated with supplementation of dietary folate. The regulation on CFTR expression was mediated by CFTR promoter methylation and trimethylation of lysine 27 on histone H3 (H3K27me3). Mechanistically, folate inhibited homocysteine-induced CFTR promoter methylation and H3K27me3, which resulted in upregulation of CFTR expression, and reduced ER stress and liver cell apoptosis. Further study showed that folate inhibited the expression of DNA methyltransferase 1 and enhancer of zeste homolog 2, downregulated the cellular concentrations of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) and upregulated the SAM/SAH ratio, leading to the inhibition of Hcy-induced DNA hypermethylation and H3K27me3 in CFTR promoter. In conclusion, our results provide insight into the protective role of folate in homocysteine-induced ER stress and liver cell apoptosis through the regulation of CFTR expression. This article is protected by copyright. All rights reserved.

  2. Hidden State Conditional Random Field for Abnormal Activity Recognition in Smart Homes

    Directory of Open Access Journals (Sweden)

    Yu Tong

    2015-03-01

    Full Text Available As the number of elderly people has increased worldwide, there has been a surge of research into assistive technologies to provide them with better care by recognizing their normal and abnormal activities. However, existing abnormal activity recognition (AAR algorithms rarely consider sub-activity relations when recognizing abnormal activities. This paper presents an application of the Hidden State Conditional Random Field (HCRF method to detect and assess abnormal activities that often occur in elderly persons’ homes. Based on HCRF, this paper designs two AAR algorithms, and validates them by comparing them with a feature vector distance based algorithm in two experiments. The results demonstrate that the proposed algorithms favorably outperform the competitor, especially when abnormal activities have same sensor type and sensor number as normal activities.

  3. Fluctuation conductivity and possible pseudogap state in FeAs-based superconductor EuFeAsO0.85F0.15

    Science.gov (United States)

    Solovjov, A. L.; Omelchenko, L. V.; Terekhov, A. V.; Rogacki, K.; Vovk, R. V.; Khlybov, E. P.; Chroneos, A.

    2016-07-01

    The study of excess conductivity σ \\prime (T) in the textured polycrystalline FeAs-based superconductor EuFeAsO0.85F0.15 ({T}{{c}}=11 {{K}}) prepared by the solid state synthesis is reported for the first time. The σ \\prime (T) analysis has been performed within the local pair (LP) model based on the assumption of the LPs formation in cuprate high-T c superconductors (cuprates) below the pseudogap (PG) temperature {T}* \\gg {T}{{c}}. Similarly to the cuprates, near {T}{{c}} σ \\prime (T) is adequately described by the 3D term of the Aslamasov-Larkin (AL) theory but the range of the 3D-AL fluctuations, {{Δ }}{T}3{{D}}, is relatively short. Above the crossover temperature {T}0≈ 11.7 {{K}} σ \\prime (T) is described by the 2D Maki-Thompson (MT) fluctuation term of the Hikami-Larkin theory. But enhanced 2D-MT fluctuation contribution being typical for the magnetic superconductors is observed. Within the LP model the PG parameter, {{{Δ }}}* (T), was determined for the first time. It is shown that {{{Δ }}}* (T) demonstrates the narrow maximum at {T}s≈ 160 {{K}} followed by the descending linear length down to {T}{SDW}={T}{NFe}≈ 133 {{K}}. Observed small {{Δ }}{T}3{{D}}, enlarged 2D σ \\prime (T) and linear {{{Δ }}}* (T) are considered to be the evidence of the enhanced magnetic interaction in EuFeAsO0.85F0.15. Importantly, the slop of the linear {{{Δ }}}* (T) and its length are found to be the same as it is revealed for SmFeAsO0.85. The results suggest both the similarity of the magnetic interaction processes in different Fe-pnictides and applicability of the LP model to the σ \\prime (T) analysis even in magnetic superconductors.

  4. Predicting risk-taking behavior from prefrontal resting-state activity and personality.

    Directory of Open Access Journals (Sweden)

    Bettina Studer

    Full Text Available Risk-taking is subject to considerable individual differences. In the current study, we tested whether resting-state activity in the prefrontal cortex and trait sensitivity to reward and punishment can help predict risk-taking behavior. Prefrontal activity at rest was assessed in seventy healthy volunteers using electroencephalography, and compared to their choice behavior on an economic risk-taking task. The Behavioral Inhibition System/Behavioral Activation System scale was used to measure participants' trait sensitivity to reward and punishment. Our results confirmed both prefrontal resting-state activity and personality traits as sources of individual differences in risk-taking behavior. Right-left asymmetry in prefrontal activity and scores on the Behavioral Inhibition System scale, reflecting trait sensitivity to punishment, were correlated with the level of risk-taking on the task. We further discovered that scores on the Behavioral Inhibition System scale modulated the relationship between asymmetry in prefrontal resting-state activity and risk-taking. The results of this study demonstrate that heterogeneity in risk-taking behavior can be traced back to differences in the basic physiology of decision-makers' brains, and suggest that baseline prefrontal activity and personality traits might interplay in guiding risk-taking behavior.

  5. Coherent states of the Euclidean group and activation regions of primary visual cortex

    CERN Document Server

    Barbieri, Davide; Sanguinetti, Gonzalo; Sarti, Alessandro

    2011-01-01

    The uncertainty principle of SE(2) allows to construct a coherent states transform that is strictly related to the Bargmann transform for the second Heisenberg group H2. The corresponding target space is characterized constructively and related to the almost complex structure of SE(2) as a contact manifold. Such a coherent state transform provides a model for neural activity maps in the primary visual cortex, that are then described in terms of minimal uncertainty states. The results of the model are compared with the experimental measurements.

  6. Spin state transition in the active center of the hemoglobin molecule: DFT + DMFT study

    Science.gov (United States)

    Novoselov, D.; Korotin, Dm. M.; Anisimov, V. I.

    2016-05-01

    An ab initio study of electronic and spin configurations of the iron ion in the active center of the human hemoglobin molecule is presented. With a combination of the Density Functional Theory (DFT) method and the Dynamical Mean Field Theory (DMFT) approach, the spin state transition description in the iron ion during the oxidation process is significantly improved in comparison with previous attempts. It was found that the origin of the iron ion local moment behavior both for the high-spin and for the low-spin states in the hemoglobin molecule is caused by the presence of a mixture of several atomic states with comparable statistical probability.

  7. Dolphin changes in whistle structure with watercraft activity depends on their behavioral state.

    Science.gov (United States)

    May-Collado, Laura J; Quiñones-Lebrón, Shakira G

    2014-04-01

    Dolphins rely on whistles to identify each other and to receive and convey information about their environment. Although capable of adjusting these signals with changing environments, there is little information on how dolphins acoustically respond to different watercraft activities and if this response depends on dolphin behavioral state. Bottlenose dolphin whistles were recorded in the presence of research and dolphin-watching boats. Dolphins emitted lower frequency and longer whistles when interacting with dolphin-watching boats, particularly during foraging activities. This study suggests that dolphin-watching boat traffic significantly hinders dolphin communication during important behavioral states.

  8. Conduct disorders

    NARCIS (Netherlands)

    Buitelaar, J.K.; Smeets, K.C.; Herpers, P.; Scheepers, F.; Glennon, J.; Rommelse, N.N.J.

    2013-01-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic

  9. Direct growth of NiCo2O4 nanostructures on conductive substrates with enhanced electrocatalytic activity and stability for methanol oxidation

    Science.gov (United States)

    Qian, Lei; Gu, Li; Yang, Li; Yuan, Hongyan; Xiao, Dan

    2013-07-01

    In this report, NiCo2O4 nanostructures with different morphologies were directly grown on conductive substrates (stainless steel and ITO) by a facile electrodeposition method in addition to a post-annealing process. The morphology changes on different conductive substrates are discussed in detail. The NiCo2O4 on stainless steel (SS) had a high surface area (119 m2 g-1) and was successfully used in the electrocatalytic oxidation of methanol. The electrocatalytic performance was investigated by cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS) measurements. Impressively, the NiCo2O4 showed much higher electrocatalytic activity, lower overpotential and greater stability compared to that of only NiO or Co3O4 synthesized by the same method. The higher electrocatalytic activity is due to the high electron conductivity, large surface area of NiCo2O4 and the fast ion/electron transport in the electrode and at the electrolyte-electrode interface. This is important for further development of high performance non-platinum electrocatalysts for application in direct methanol fuel cells.In this report, NiCo2O4 nanostructures with different morphologies were directly grown on conductive substrates (stainless steel and ITO) by a facile electrodeposition method in addition to a post-annealing process. The morphology changes on different conductive substrates are discussed in detail. The NiCo2O4 on stainless steel (SS) had a high surface area (119 m2 g-1) and was successfully used in the electrocatalytic oxidation of methanol. The electrocatalytic performance was investigated by cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS) measurements. Impressively, the NiCo2O4 showed much higher electrocatalytic activity, lower overpotential and greater stability compared to that of only NiO or Co3O4 synthesized by the same method. The higher electrocatalytic activity is due to the high electron conductivity

  10. Frontopolar activity and connectivity support dynamic conscious augmentation of creative state.

    Science.gov (United States)

    Green, Adam E; Cohen, Michael S; Raab, Hillary A; Yedibalian, Christopher G; Gray, Jeremy R

    2015-03-01

    No ability is more valued in the modern innovation-fueled economy than thinking creatively on demand, and the "thinking cap" capacity to augment state creativity (i.e., to try and succeed at thinking more creatively) is of broad importance for education and a rich mental life. Although brain-based creativity research has focused on static individual differences in trait creativity, less is known about changes in creative state within an individual. How does the brain augment state creativity when creative thinking is required? Can augmented creative state be consciously engaged and disengaged dynamically across time? Using a novel "thin slice" creativity paradigm in 55 fMRI participants performing verb-generation, we successfully cued large, conscious, short-duration increases in state creativity, indexed quantitatively by a measure of semantic distance derived via latent semantic analysis. A region of left frontopolar cortex, previously associated with creative integration of semantic information, exhibited increased activity and functional connectivity to anterior cingulate gyrus and right frontopolar cortex during cued augmentation of state creativity. Individual differences in the extent of increased activity in this region predicted individual differences in the extent to which participants were able to successfully augment state creative performance after accounting for trait creativity and intelligence.

  11. Voltammetry of conducting polymers

    OpenAIRE

    Gulaboski, Rubin

    2014-01-01

    The search for new materials for enhancing electrical conductivity of various materials is one of the most active research areas today. Conducting polymers represent a unique class of organic materials that have been used in many applications such as bioelectronics, sensors, corrosion protection, electrocatalysis, and energy storage devices. Application of the conductive polymers in electrochemistry is almost inevitable in order to get better features of the voltammetric systems ...

  12. Analysis of the interaction between the dendritic conductance density and activated area in modulating alpha-motoneuron EPSP: statistical computer model.

    Science.gov (United States)

    Gradwohl, Gideon; Grossman, Yoram

    2008-06-01

    Five reconstructed alpha-motoneurons (MNs) are simulated under physiological and morphological realistic parameters. We compare the resulting excitatory postsynaptic potential (EPSP) of models, containing voltage-dependent channels on the dendrites, with the EPSP of a passive MN and an active soma and axon model. In our simulations, we apply three different distribution functions of the voltage-dependent channels on the dendrites: a step function (ST) with uniform spatial dispersion; an exponential decay (ED) function, with proximal to the soma high-density location; and an exponential rise (ER) with distally located conductance density. In all cases, the synaptic inputs are located as a gaussian function on the dendrites. Our simulations lead to eight key observations. (1) The presence of the voltage-dependent channels conductance (g(Active)) in the dendrites is vital for obtaining EPSP peak boosting. (2) The mean EPSP peaks of the ST, ER, and ED distributions are similar when the ranges of G (total conductance) are equal. (3) EPSP peak increases monotonically when the magnitude of g(Na_step) (maximal g(Na) at a particular run) is increased. (4) EPSP kinetics parameters were differentially affected; time integral was decreased monotonically with increased g(Na_step), but the rate of rise (the decay time was not analyzed) does not show clear relations. (5) The total G can be elevated by increasing the number of active dendrites; however, only a small active area of the dendritic tree is sufficient to get the maximal boosting. (6) The sometimes large variations in the parameters values for identical G depend on the g(Na_step) and active dendritic area. (7) High g(Na_step) in a few dendrites is more efficient in amplifying the EPSP peak than low g(Na_step) in many dendrites. (8) The EPSP peak is approximately linear with respect to the MNs' R(N) (input resistance).

  13. Reduction in Cortical Gamma Synchrony during Depolarized State of Slow Wave Activity in Mice

    Directory of Open Access Journals (Sweden)

    EUNJIN eHWANG

    2013-12-01

    Full Text Available EEG gamma band oscillations have been proposed to account for the neural synchronization crucial for perceptual integration. While increased gamma power and synchronization is generally observed during cognitive tasks performed during wake, several studies have additionally reported increased gamma power during sleep or anesthesia, raising questions about the characteristics of gamma oscillation during impaired consciousness and its role in conscious processing. Phase-amplitude modulation has been observed between slow wave activity (SWA, 0.5–4 Hz and gamma oscillations during ketamine/xylazine anesthesia or sleep, showing increased gamma activity corresponding to the depolarized (ON state of SWA. Here we divided gamma activity into its ON and OFF (hyperpolarized state components based on the phase of SWA induced by ketamine/xylazine anesthesia and compared their power and synchrony with wake state levels in mice. We further investigated the state-dependent changes in both gamma power and synchrony across primary motor and primary somatosensory cortical regions and their interconnected thalamic regions throughout anesthesia and recovery. As observed previously, gamma power was as high as during wake specifically during the ON state of SWA. However, the synchrony of this gamma activity between somatosensory-motor cortical regions was significantly reduced compared to the baseline wake state. In addition, the somatosensory-motor cortical synchrony of gamma oscillations was reduced and restored in an anesthetic state-dependent manner, reflecting the changing depth of anesthesia. Our results provide evidence that during anesthesia changes in long-range information integration between cortical regions might be more critical for changes in consciousness than changes in local gamma oscillatory power.

  14. Computational model of touch sensory cells (T Cells) of the leech: role of the afterhyperpolarization (AHP) in activity-dependent conduction failure.

    Science.gov (United States)

    Cataldo, Enrico; Brunelli, Marcello; Byrne, John H; Av-Ron, Evyatar; Cai, Yidao; Baxter, Douglas A

    2005-01-01

    Bursts of spikes in T cells produce an AHP, which results from activation of a Na+/K+ pump and a Ca2+-dependent K+ current. Activity-dependent increases in the AHP are believed to induce conduction block of spikes in several regions of the neuron, which in turn, may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we used the neurosimulator SNNAP to develop a multi-compartmental model of the T cell. The model incorporated empirical data that describe the geometry of the cell and activity-dependent changes of the AHP. Simulations indicated that at some branching points, activity-dependent increases of the AHP reduced the number of spikes transmitted from the minor receptive fields to the soma and beyond. More importantly, simulations also suggest that the AHP could modulate, under some circumstances, transmission from the soma to the synaptic terminals, suggesting that the AHP can regulate spike conduction within the presynaptic arborizations of the cell and could in principle contribute to the synaptic depression that is correlated with increases in the AHP.

  15. Correlations in background activity control persistent state stability and allow execution of working memory tasks

    Directory of Open Access Journals (Sweden)

    Mario eDipoppa

    2013-10-01

    Full Text Available Working memory (WM is tightly capacity limited, it requires selective information gating, active information maintenance, and rapid active updating. Hence performing a WM task needs rapid and controlled transitions between neural persistent activity and the resting state. We propose that changes in spike-time correlations in neural activity provides a mechanism for the required working memory operations. As a proof of principle, we implement sustained activity and working memory in a recurrently-coupled spiking network with neurons receiving excitatory random background activity where background correlations are induced by a common noise source. We first characterize how the level of background correlations controls the stability of the persistent state. With sufficiently high correlations, the sustained state becomes practically unstable, so it cannot be initiated by a transient stimulus. We exploit this in a working memory model implementing the delay match to sample task by modulating flexibly in time the correlation level at different phases of the task. The modulation sets the network in different working regimes: more prompt to gate in a signal or clear the memory. The findings presented in this manuscript can form the basis for a new paradigm about how correlations are flexibly controlled by the cortical circuits to execute WM operations.

  16. An experimental method to identify neurogenic and myogenic active mechanical states of intestinal motility

    Directory of Open Access Journals (Sweden)

    Marcello eCosta

    2013-04-01

    Full Text Available Excitatory and inhibitory enteric neural input to intestinal muscle acting on ongoing myogenic activity determines the rich repertoire of motor patterns involved in digestive function. The enteric neural activity cannot yet be established during movement of intact intestine in vivo or in vitro. We propose the hypothesis that is possible to deduce indirectly, but reliably, the state of activation of the enteric neural input to the muscle from measurements of the mechanical state of the intestinal muscle. The fundamental biomechanical model on which our hypothesis is based is the ‘three-element model’ proposed by Hill. Our strategy is based on simultaneous video recording of changes in diameters and intraluminal pressure with a fibre-optic manometry in isolated segments of rabbit colon. We created a composite spatiotemporal map (DPMap from diameter (DMap and pressure changes (PMaps. In this composite map rhythmic myogenic motor patterns can readily be distinguished from the distension induced neural peristaltic contractions. Plotting the diameter changes against corresponding pressure changes at each location of the segment, generates ‘orbits’ that represent the state of the muscle according to its ability to contract or relax actively or undergoing passive changes. With a software developed in MatLab, we identified twelve possible discrete mechanical states and plotted them showing where the intestine actively contracted and relaxed isometrically, auxotonically or isotonically, as well as where passive changes occurred or was quiescent. Clustering all discrete active contractions and relaxations states generated for the first time a spatio-temporal map of where enteric excitatory and inhibitory neural input to the muscle occurs during physiological movements. Recording internal diameter by an impedance probe proved equivalent to measuring external diameter, making possible to further develop similar strategy in vivo and humans.

  17. Identification of resting and active state EEG features of Alzheimer's disease using discrete wavelet transform.

    Science.gov (United States)

    Ghorbanian, Parham; Devilbiss, David M; Verma, Ajay; Bernstein, Allan; Hess, Terry; Simon, Adam J; Ashrafiuon, Hashem

    2013-06-01

    Alzheimer's disease (AD) is associated with deficits in a number of cognitive processes and executive functions. Moreover, abnormalities in the electroencephalogram (EEG) power spectrum develop with the progression of AD. These features have been traditionally characterized with montage recordings and conventional spectral analysis during resting eyes-closed and resting eyes-open (EO) conditions. In this study, we introduce a single lead dry electrode EEG device which was employed on AD and control subjects during resting and activated battery of cognitive and sensory tasks such as Paced Auditory Serial Addition Test (PASAT) and auditory stimulations. EEG signals were recorded over the left prefrontal cortex (Fp1) from each subject. EEG signals were decomposed into sub-bands approximately corresponding to the major brain frequency bands using several different discrete wavelet transforms and developed statistical features for each band. Decision tree algorithms along with univariate and multivariate statistical analysis were used to identify the most predictive features across resting and active states, separately and collectively. During resting state recordings, we found that the AD patients exhibited elevated D4 (~4-8 Hz) mean power in EO state as their most distinctive feature. During the active states, however, the majority of AD patients exhibited larger minimum D3 (~8-12 Hz) values during auditory stimulation (18 Hz) combined with increased kurtosis of D5 (~2-4 Hz) during PASAT with 2 s interval. When analyzed using EEG recording data across all tasks, the most predictive AD patient features were a combination of the first two feature sets. However, the dominant discriminating feature for the majority of AD patients were still the same features as the active state analysis. The results from this small sample size pilot study indicate that although EEG recordings during resting conditions are able to differentiate AD from control subjects, EEG activity

  18. Conductive porous sponge-like ionic liquid-graphene assembly decorated with nanosized polyaniline as active electrode material for supercapacitor

    Science.gov (United States)

    Halab Shaeli Iessa, K.; Zhang, Yan; Zhang, Guoan; Xiao, Fei; Wang, Shuai

    2016-01-01

    We report the development of three-dimensional (3D) porous sponge-like ionic liquid (IL)-graphene hybrid material by integrating IL molecules and graphene nanosheets via self-assembly process. The as-obtained IL-graphene architecture possesses high surface area, efficient electron transport network and fast charge transfer kinetics owing to its highly porous structure, and unique hydrophilic properties derived from the IL anion on its surface, which endows it with high desire for supercapacitor application. Redox-active polyaniline (PANI) nanorods are further decorated on IL-graphene scaffold by electropolymerization. When utilized as freestanding 3D electrode for supercapacitor, the resultant PANI modified IL-graphene (PANI-IL-graphene) electrode exhibits a specific capacitance up to 662 F g-1 at the current density of 1.0 A g-1, with a high capacitance retention of 73.7% as current densities increase from 1.0 to 20 A g-1, and the capacitance degradation is less than 7.0% after 5000 charge-discharge cycles at 10 A g-1.

  19. Glucocorticoid-induced impairment of macrophage antimicrobial activity: mechanisms and dependence on the state of activation.

    Science.gov (United States)

    Schaffner, A; Schaffner, T

    1987-01-01

    Experimental observations indicate that tissue macrophages deployed in great numbers at critical anatomic sites such as the liver, spleen, and lung are major targets for glucocorticoids compromising natural resistance of the host. Therapeutic concentrations of glucocorticoids appear to prevent destruction of microorganisms ingested by macrophages without interfering with phagocytosis, phagolysosomal fusion, and/or secretion of reactive oxygen intermediates. These findings indicate that at the cellular level the glucocorticoid target should be sought for in the nonoxidative armature of the phagocyte and that nonoxidative killing systems of resident tissue macrophages play an important role in natural resistance to opportunistic pathogens. Glucocorticoids do not prevent lymphokine-induced activation of oxidative killing systems. Thus, lymphokines such as interferon-gamma can restore the microbicidal activity of macrophages functionally impaired by glucocorticoids. Counterbalance of the suppressive effect of glucocorticoids by lymphokines might only be possible, however, for pathogens susceptible to oxidative killing and not for microorganisms that are more resistant to reactive oxygen intermediates such as Aspergillus spores and Nocardia, opportunists that appear to be particularly associated with hypercortisolism.

  20. Inadequate physical activity and health care expenditures in the United States.

    Science.gov (United States)

    Carlson, Susan A; Fulton, Janet E; Pratt, Michael; Yang, Zhou; Adams, E Kathleen

    2015-01-01

    This study estimates the percentage of health care expenditures in the non-institutionalized United States (U.S.) adult population associated with levels of physical activity inadequate to meet current guidelines. Leisure-time physical activity data from the National Health Interview Survey (2004-2010) were merged with health care expenditure data from the Medical Expenditure Panel Survey (2006-2011). Health care expenditures for inactive (i.e., no physical activity) and insufficiently active adults (i.e., some physical activity but not enough to meet guidelines) were compared with active adults (i.e., ≥150minutes/week moderate-intensity equivalent activity) using an econometric model. Overall, 11.1% (95% CI: 7.3, 14.9) of aggregate health care expenditures were associated with inadequate physical activity (i.e., inactive and insufficiently active levels). When adults with any reported difficulty walking due to a health problem were excluded, 8.7% (95% CI: 5.2, 12.3) of aggregate health care expenditures were associated with inadequate physical activity. Increasing adults' physical activity to meet guidelines may reduce U.S. health care expenditures.